tretinoin and Carcinoma--Squamous-Cell

Fanconi's anaemia is a rare genetic disorder and majority of the patients die of haematologic complications in their second or third decades of life. Others who have mild or no cytopenias survive long enough to develop malignancies. This is a report of a 44-year-old woman who presented with recurrent oral squamous cell carcinoma during her adulthood, without clinical haematological problem. Despite treatment with cis-retinoic acid, she developed a third squamous cell carcinoma 6 months later. In a review of the literature, only in 1 reported case was the patient treated with low-dose retinoids but he developed recurrent anal cancer after 14 months.

Topics: Adolescent; Adult; Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Child; Dogs; Fanconi Anemia; Female; Humans; Mouth Neoplasms; Neoplasm Recurrence, Local; Prognosis; Reoperation; Survival Rate; Tretinoin

9-cis retinoic acid (9-cis RA) is a retinoid receptor pan-agonist that binds with high affinity to both retinoic acid receptors (RARs) and retinoid X receptors (RXRs). Using a variety of in vivo and in vitro cancer models, we present experimental data that 9-cis RA has activity as a potential chemotherapeutic agent. Treatment of the human promyelocytic leukemia cell line HL-60 with 9-cis RA decreases cell proliferation, increases cell differentiation, and increases apoptosis. Induction of apoptosis correlates with an increase in tissue transglutaminase (type II) activity. In vivo, 9-cis RA induces complete tumor regression of an early passage human lip squamous cell carcinoma xenograft. Finally, 9-cis RA inhibits the anchorage-independent growth of the human breast cancer cell lines MCF-7 and LY2 (an antiestrogen-resistant MCF-7 variant). Transient co-transfection assays indicate that 9-cis RA inhibits estrogen receptor transcription of an ERE-tk-LUC reporter through RAR or RXR receptors. These data suggest that retinoid receptors can antagonize estrogen-dependent transcription and provides one possible mechanism for the inhibition of cell growth by 9-cis RA in breast cancer cell lines. In summary, these findings present evidence that 9-cis RA has a wide range of activities in human cancer models.

Topics: Animals; Apoptosis; Breast Neoplasms; Carcinoma, Squamous Cell; Cell Division; HL-60 Cells; Humans; Neoplasms; Tretinoin

Preclinical data indicate that the combination of retinoids and interferons have synergistic antiproliferative and differentiating effects in some hematologic and solid tumor models. These observations have led to clinical trials in which 13-cis-retinoic acid (13cRA) 1 mg/kg/day was combined with interferon alpha-2a (IFN alpha) 3 or 6 x 10(6) U/day. The first two such trials produced exciting results: 50% response rate in patients with previously untreated stages IB-IVA cervix cancer and 68% in patients with advanced squamous cell skin cancer. These data led to a number of additional trials of the combination, but the high response rates seen in the initial cervix and skin trials have not been duplicated in the other squamous tumors tested (head and neck, lung, pretreated cervix). In addition, trials in two nonsquamous histologies were negative (lung and melanoma). However, the regimen was not always studied in an optimal population of previously untreated patients and the negative results in pretreated cervix patients point to the relevance of this consideration. Nevertheless, the observation that the combination of 13cRA and IFN alpha (both of which bind to specific receptors and change gene expression) is able to induce regression in advanced tumors, must be regarded as highly important. Key questions to be addressed include an understanding of the biologic mechanism of specific tumor sensitivity (why some squamous tumors and not others?), and mechanisms of resistance in sensitive tumor types (e.g. cervix). Such data may lead to trials targeted to tumor types with defined biologic features having a high liklihood of clinical benefit. In the meantime, studies integrating this combination with other active treatment modalities such as radiation is warranted in cervix and skin carcinomas.

Topics: Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Squamous Cell; Clinical Trials as Topic; Female; Humans; Interferon alpha-2; Interferon-alpha; Neoplasms; Recombinant Proteins; Tretinoin

Overexposure to ultraviolet and visible radiation causes sunburn. Aspirin and other nonsteroidal anti-inflammatory drugs, cool baths and topical steroids offer only mild relief. Long-term sun exposure causes chronic inflammatory skin changes. Photodamage, rather than the normal aging process, may account for 90 percent of age-associated cosmetic skin problems. Physicians should stress to their patients that all ultraviolet exposure (including sun beds and tanning salons) causes skin damage. Regular sunscreen use during childhood and adolescence may result in an 80 percent reduction in the lifetime incidence of ultraviolet-induced skin damage, including nonmelanoma skin cancers.

Topics: Carcinoma, Squamous Cell; Hemoglobins; Humans; Light; Melanins; Skin; Skin Aging; Skin Neoplasms; Skin Pigmentation; Sunburn; Sunscreening Agents; Tretinoin; Ultraviolet Rays

Retinoic acid and interferon-alpha have limited single-agent activity in advanced cancer. Cell culture data indicate that in combination these agents have enhanced activity (modulating growth and differentiation) in a number of malignant cell types. Recent clinical work in advanced squamous cell carcinoma reports major activity with this regimen. This paper reviews the preclinical and clinical data testing retinoic acid in combination with interferons and presents recent work integrating these agents with radiotherapy in locally advanced cervical cancer.

Topics: Adult; Aged; Carcinoma, Squamous Cell; Combined Modality Therapy; Female; Humans; Interferon-alpha; Middle Aged; Skin Neoplasms; Tretinoin; Uterine Cervical Neoplasms

Cancer appears to be a disease of altered maturation, with changes in genetic expression leading to a situation in which the physiological regulation of cellular proliferation and maturation are altered. Environmental factors as well as defined chemical agents have been demonstrated to have the capacity to convert neoplastic cells to end-stage forms with a finite life span through a process characteristic of cellular maturation. The correction of genetic defects by these inducers of differentiation does not appear to be required; the critical feature is that the differentiated cells assume a state in which they no longer possess the capability for continued cellular replication. The extrapolation of these advances, accomplished in experimental systems, to clinical practice should yield significant decreases in the neoplastic cell burden without the degree of morbidity produced by aggressive therapy with cytodestructive agents, especially when employed in multidrug combinations. The ultimate introduction of differentiation as a therapeutic approach to cancer treatment if attained, however, will require a variety of principles to be established, so that optimum efficacy may be obtained from each agent, the fabrication of new agents with major changes in the ratio of the concentrations required to produce cytotoxicity relative to those necessary to initiate maturation is attained, and the elucidation of non-antagonistic combinations of differentiation inducing agents with or without cytotoxic drugs is achieved to combat the problem of tumor cell heterogeneity.

Topics: Animals; Antibiotics, Antineoplastic; Carcinoma, Squamous Cell; Cell Line; Cell Survival; Cell Transformation, Neoplastic; Humans; Hydrocortisone; Leukemia, Experimental; Models, Biological; Naphthacenes; Phenotype; Thioguanine; Tretinoin

Most drugs available for cancer chemotherapy exert their effects through cytodestruction. Although significant advances have been attained with these cytotoxic agents in several malignant diseases, response is often accompanied by significant morbidity and many common malignant tumours respond poorly to existing cytotoxic therapy. Development of chemotherapeutic agents with non-cytodestructive actions appears desirable. Considerable evidence exists which indicates that (a) the malignant state is not irreversible and represents a disease of altered maturation, and (b) some experimental tumour systems can be induced by chemical agents to differentiate to mature end-stage cells with no proliferative potential. Thus, it is conceivable that therapeutic agents can be developed which convert cancer cells to benign forms. To study the phenomenon of blocked maturation, squamous carcinoma SqCC/Y1 cells were employed in culture. Using this system it was possible to demonstrate that physiological levels of retinoic acid and epidermal growth factor were capable of preventing the differentiation of these malignant keratinocytes into a mature tissue-like structure. The terminal differentiation caused by certain antineoplastic agents was investigated in HL-60 promyelocytic leukaemia cells to provide information on the mechanism by which chemotherapeutic agents induce cells to by-pass a maturation block. The anthracyclines aclacinomycin A and marcellomycin were potent inhibitors of N-glycosidically linked glycoprotein biosynthesis and transferrin receptor activity, and active inducers of maturation; temporal studies suggested that the biochemical effects were associated with the differentiation process. 6-Thioguanine produced cytotoxicity in parental cells by forming analog nucleotide. In hypoxanthine-guanine phosphoribosyltransferase negative HL-60 cells the 6-thiopurine initiated maturation; this action was due to the free base (and possibly the deoxyribonucleoside), a finding which separated termination of proliferation due to cytotoxicity from that caused by maturation.

Topics: Antibiotics, Antineoplastic; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Differentiation; Cell Division; Cell Line; Cell Survival; Cell Transformation, Neoplastic; Epidermal Growth Factor; Humans; Leukemia, Myeloid; Models, Biological; Naphthacenes; Thioguanine; Tretinoin

Invasive squamous cell carcinoma (SCC) of the skin is one of the most common cancers in the United States, with no proven means for prevention other than systemic retinoids, which have significant toxicity, and sunscreen. We sought to determine the risk factors for invasive SCC on the face or ears in a high-risk population comprising 1,131 veterans in the Veterans Affairs Topical Tretinoin Chemoprevention (VATTC) Trial. Participants were required to have been diagnosed with at least two keratinocyte carcinomas (KCs) in the 5 years prior to enrollment. The median duration of follow-up was 3.7 years. Twenty-three percent of the participants developed a new invasive SCC, and the cumulative risk of invasive SCC was 30% at 5 years. The following factors independently predicted for new invasive SCCs: number of invasive SCCs and number of in situ SCCs in the 5 years prior to enrollment, actinic keratoses count at enrollment, a history of ever use of topical 5-fluorouracil, and total occupational time spent outdoors. In contrast, the use of angiotensin-convering enzyme inhibitors or angiotensin receptor blockers during the study and a history of warts anywhere on the body were found to protect against new invasive SCCs. These independent predictors remained the same for all SCCs (invasive and in situ combined). The number of basal cell carcinomas in the 5 years prior to enrollment, sunburns, sun sensitivity, and recreational sun exposure were not associated with new SCCs. These findings identify key risk factors for additional SCCs in patients with multiple prior KCs, and suggest that a history of warts may be associated with reduced SCC risk.

Topics: Aged; Aged, 80 and over; Antineoplastic Agents; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Female; Follow-Up Studies; Humans; Male; Middle Aged; Multivariate Analysis; Predictive Value of Tests; Risk Factors; Skin Neoplasms; Sunburn; Sunscreening Agents; Tretinoin; Veterans; Warts

Glucorticosteroids (GC) are potent anti-inflammatory medications with immunosuppressive property. Few retrospective studies have reported the increased risk of development of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) associated with GC use.. We aimed to assess the effect of oral GC use on the risk of BCC and SCC using prospective data.. We analysed data from the Veterans Affairs Topical Tretinoin Chemoprevention Trial, which followed up patients from 1998 to 2004. Exposure to oral GCs was defined as (1) use of any oral GCs at any point during follow-up and (2) use of GCs for a month or longer. Outcome was occurrence of new BCC or SCC. Cox proportional hazard models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).. Among the 1051 study participants, 148 patients (14%) had prednisone prescription filled during study period, and 63 (6%) used prednisone for over a month. A total of 472 patients (45%) developed at least one BCC during study: 394 (44%) among non-users of prednisone and 78 (53%) among any time users. The total number of new SCC was 309 (29%): 258 (29%) among non-users of prednisone and 51 (34%) among users. Among any time prednisone users, the adjusted HR was 1.11 (95% CI, 0.87-1.42) for BCC, and 1.05 (95% CI, 0.76-1.45) for SCC. Among those who used prednisone for 30 or more days, the HR was 1.26 (95% CI, 0.90-1.78) for BCC, and 1.03 (95% CI, 0.66-1.60) for SCC.. This study does not support the existence of association between use of oral GCs and risk of BCC or SCC.

Topics: Administration, Oral; Aged; Aged, 80 and over; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Female; Humans; Male; Middle Aged; Prednisone; Skin Neoplasms; Tretinoin

Keratinocyte carcinoma (KC) is the most common cancer in the United States, with no proven means for prevention other than systemic retinoids, which have significant toxicity, and sunscreen. Topical tretinoin has been used for KC chemoprevention, although this use is unproven. Hence, we conducted the randomized Veterans Affairs Topical Tretinoin Chemoprevention Trial of high-dose topical tretinoin for KC prevention. We randomized 1,131 patients to topical 0.1% tretinoin or a matching vehicle control for 1.5-5.5 years. The primary outcomes were time to development of new basal cell carcinoma (BCC) and new invasive squamous cell carcinoma (SCC) on the face or ears. The effects were not significant (P=0.3 for BCC and P=0.4 for SCC). The proportions of the tretinoin and control groups who developed a BCC at 5 years were 53 and 54% and an invasive SCC at 5 years were 28 and 31%. These differences (95% confidence intervals) were: for BCC, 1.0% (-6.5, 8.6%); for SCC, 3.6% (-3.1, 10.3%). No differences were observed in any cancer-related end points or in actinic keratosis counts. The only quality of life difference was worse symptoms in the tretinoin group at 12 months after randomization. This trial in high-risk patients demonstrates that high-dose topical tretinoin is ineffective at reducing risk of KCs.

Topics: Administration, Topical; Aged; Aged, 80 and over; Antineoplastic Agents; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Female; Humans; Keratinocytes; Male; Middle Aged; Quality of Health Care; Risk Factors; Skin Neoplasms; Tretinoin; Veterans

Recent evidence suggests that statins may prevent cancer.. To quantify the association between statin use and the occurrence of keratinocyte carcinoma in high-risk veterans.. Cohort study.. 6 Veterans Affairs medical centers.. 1037 participants of the Veterans Affairs Topical Tretinoin Chemoprevention Trial, a randomized, multicenter, double-blind, vehicle-controlled trial of topical tretinoin, 0.1%, for prevention of keratinocyte carcinoma conducted from November 1998 to November 2004.. Time to first occurrence of keratinocyte carcinoma on the face or ears. Participants using a statin at randomization, according to the Veterans Affairs Pharmacy Benefits Management database, were considered exposed. Study dermatologists conducted physical examinations at baseline and every 6 months during follow-up. The association between statin use at randomization and the outcome was evaluated by using propensity score matching (n = 608) and Cox proportional hazards regression (n = 1037).. Among the 1037 participants, 37% used a statin at randomization (n = 397) for a median duration of at least 900 days over a median follow-up of 3.5 years. In the propensity score-matched analysis, statin use at randomization was not associated with keratinocyte carcinoma (rate ratio, 0.92 [95% CI, 0.73 to 1.16]), a finding that was consistent with the estimates derived from the Cox proportional hazards regression (rate ratio, 0.84 [CI, 0.70 to 1.02]).. The extent of residual confounding is unknown, and the confidence bounds around the measures of association were wide. These data may not be generalizable to lower-risk populations.. These data show no conclusive or consistent relationship between long-term statin use and risk for keratinocyte carcinoma.

Topics: Administration, Topical; Aged; Aged, 80 and over; Antineoplastic Agents; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Confounding Factors, Epidemiologic; Double-Blind Method; Drug Administration Schedule; Ear Neoplasms; Facial Neoplasms; Female; Humans; Male; Middle Aged; Neoplasm Recurrence, Local; Risk Factors; Skin Neoplasms; Tretinoin

To evaluate the relation of topical tretinoin, a commonly used retinoid cream, with all-cause mortality in the Veterans Affairs Topical Tretinoin Chemoprevention Trial (VATTC). The planned outcome of this trial was risk of keratinocyte carcinoma, and systemic administration of certain retinoid compounds has been shown to reduce risk of this cancer but has also been associated with increased mortality risk among smokers.. The VATTC Trial was a blinded randomized chemoprevention trial, with 2- to 6-year follow-up. Oversight was provided by multiple independent committees.. US Department of Veterans Affairs medical centers. Patients A total of 1131 veterans were randomized. Their mean age was 71 years. Patients with a very high estimated short-term risk of death were excluded. Interventions Application of tretinoin, 0.1%, or vehicle control cream twice daily to the face and ears.. Death, which was not contemplated as an end point in the original study design.. The intervention was terminated 6 months early because of an excessive number of deaths in the tretinoin-treated group. Post hoc analysis of this difference revealed minor imbalances in age, comorbidity, and smoking status, all of which were important predictors of death. After adjusting for these imbalances, the difference in mortality between the randomized groups remained statistically significant.. We observed an association of topical tretinoin therapy with death, but we do not infer a causal association that current evidence suggests is unlikely.

Topics: Administration, Topical; Aged; Antineoplastic Agents; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Cause of Death; Double-Blind Method; Female; Humans; Male; Skin Neoplasms; Tretinoin

Keratinocyte carcinomas (KCs) are the most common malignancies of the skin. As lesions have a low mortality rate, understanding quality-of-life (QoL) factors is necessary in their management.. To assess QoL and associated patient characteristics in those with a history of keratinocyte carcinomas.. We conducted a cross-sectional study of veterans with a history of KCs enrolled in a randomized controlled trial for chemoprevention of keratinocyte carcinomas. Study dermatologists counted actinic keratoses (AKs) and assessed for skin photodamage. QoL was assessed using Skindex-29 and KC-specific questions. Demographics were self-reported.. Participants (n = 931) enrolled at 5 clinical sites had worse QoL on all subscales (emotions, functioning, and symptoms) compared to a reference group of patients without skin disease. Univariate analysis demonstrated worse QoL associated with higher AK count, past 5-fluorouracil (5-FU) use, and greater sun sensitivity. Multivariate analysis demonstrated that higher AK count and past 5-FU use were independently related to diminished QoL. Higher comorbidities showed modest associations on the symptoms and functioning subscales. Number of previous KCs was not independently associated with any QoL differences.. Study population may not be generalizable to the general population. Counting of AKs is of limited reliability. Previous 5-FU use is self reported.. A history of ever use of 5-FU and present AKs was strongly associated with worse QoL. We find it more useful to consider these patients as having the chronic condition "actinic neoplasia syndrome," whose burden may be best measured by factors other than their history of KCs.

Topics: Administration, Topical; Aged; Aged, 80 and over; Analysis of Variance; Carcinoma, Squamous Cell; Chemoprevention; Cross-Sectional Studies; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Hospitals, Veterans; Humans; Immunohistochemistry; Keratosis, Actinic; Male; Middle Aged; Multivariate Analysis; Precancerous Conditions; Probability; Quality of Life; Risk Assessment; Severity of Illness Index; Skin Neoplasms; Treatment Outcome; Tretinoin

Topical tretinoin is a medication commonly used for acne that has potential application in the long-term treatment of photodamaged skin. However, there are few published data regarding the tolerability of high-dose tretinoin with long-term use.. To assess the long-term tolerability of tretinoin 0.1% cream.. A randomized, multicentre, double-blind, controlled trial for chemoprevention of keratinocyte carcinomas (i.e. basal cell or squamous cell carcinomas) using topical tretinoin cream to the face and ears was conducted. All participants were veterans and had a history of two or more keratinocyte carcinomas over the previous 5 years. Participants were examined (by a study dermatologist) and interviewed every 6 months (for up to 5.5 years to May 2004). Treatment comprised tretinoin 0.1% cream or vehicle control cream once daily, then twice daily as tolerated. Participants were instructed to step down application frequency to once daily or less if twice daily was not tolerated. The main outcome measures were reported side-effects, frequency of cream application and attendance at study visits. Appropriate data were available for four of the six clinical sites of this trial.. Data from 736 randomized participants (mean age 71 years; 97% men) from four clinical sites were analysed. The tretinoin group more commonly reported one or more side-effects at the 6-month follow-up than the control group (61% vs. 42%, P < 0.0001). Side-effects decreased over time in both groups, but to a greater extent in the tretinoin group, and the difference became nonsignificant at 30 months. Burning was the most common side-effect (39% tretinoin vs. 17% control, P < 0.0001). There was no difference in severity of side-effects among those affected. Of the participants who reported burning in either group, most reported mild burning; only 11% of those with burning in the tretinoin group reported it as severe (mild 62% tretinoin vs. 70% placebo; severe 11% vs. 5%; P = 0.4). Itching (24% vs. 16%, P = 0.01) and other local cutaneous reactions (12% vs. 6%, P = 0.01) were also more commonly reported by the tretinoin group at 6 months. There was no difference in numbness (2% vs. 2%, P = 0.9). Participants in the tretinoin group were less likely to apply cream twice daily at 6 months (29% vs. 43%, P = 0.0002). This difference persisted over the entire duration of follow-up. There was little difference between groups in attendance at study visits or completion of telephone interviews (92% vs. 95%, P = 0.06). No unexpected adverse events were reported.. Overall, the tolerability level of topical tretinoin was high in this study population, with almost 40% of the tretinoin group reporting no side-effects, and the majority (67%) tolerating at least once-daily dosing at 6-month follow-up. High-dose topical tretinoin is feasible for long-term use in this population.

Topics: Administration, Topical; Aged; Antineoplastic Agents; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Ear Neoplasms; Ear, External; Facial Neoplasms; Female; Humans; Male; Skin Neoplasms; Time Factors; Treatment Outcome; Tretinoin; Veterans

We sought to determine the interobserver reliability of the histopathologic diagnosis of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) (keratinocyte carcinomas) in the setting of a Department of Veteran Affairs multicenter chemoprevention study.. Interobserver concordance was assessed by blinded review of histopathologic slides by study dermatopathologists.. Overall interobserver agreement between the two dermatopathogists was kappa = 0.69 (95% confidence interval [CI] 0.67-0.69). The dermatopathologists' interobserver agreement was highest for basal cell carcinoma at kappa = 0.88 (95% CI 0.84-0.91) and for a diagnostic category in the SCC-actinic keratosis spectrum at kappa = 0.80 (95% CI 0.73-0.86). The largest disagreements between the two reference dermatopathologists were regarding the categories of invasive SCC at kappa = 0.62 (95% CI 0.52-0.72), SCC in situ at kappa = 0.42 (95% CI 0.29-0.56), and actinic keratosis at kappa = 0.51 (95% CI 0.40-0.62). Agreement between the local pathologists and central reference dermatopathologists were similar to the agreement between the central dermatopathologists. The morphea subtype of basal cell carcinoma was the only reliably diagnosed subtype (kappa = 0.79, 95% CI 0.51-1.00), and tumor depth was reliably measured.. A limitation of this study was the use of only two reference dermatopathologists.. Because of the impact on physician decision making and patient care, researchers and clinicians need to be aware of reliability of histopathology results, particularly pertaining to the SCC and actinic keratosis spectrum.

Topics: Biopsy; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Ear Neoplasms; Facial Neoplasms; Humans; Keratinocytes; Keratolytic Agents; Keratosis; Neoplasm Invasiveness; Observer Variation; Photosensitivity Disorders; Reproducibility of Results; Tretinoin

Although retinoids show promise for prevention of second primary upper aerodigestive tract tumors, the optimum retinoid, dose, and schedule are unknown. All-trans retinoic acid (ATRA) has greater affinity for retinoic acid receptors and may be more active than other retinoids but has a shorter plasma half life and may up-regulate its own metabolism. We defined the maximum long-term tolerable dose, dosing frequency, pharmacokinetics, and toxicity of ATRA in patients with treated squamous cell carcinoma of the head and neck (SCCHN). Twenty-one patients were randomized to 45, 90, or 150 mg/m2 ATRA either once daily, or as divided doses every 8 h, for 1 year. Pharmacokinetics were assessed periodically. Fourteen men and seven women with previous SCCHN of initial stage I-IV were treated. Grade > or =3 toxicities (reversible) included headache and hypertriglyceridemia in 5 and 6 patients each, mucositis in 2 patients, and hyperbilirubinemia, elevated alkaline phosphatase, colitis, lipasemia, xerostomia, eczema, and arthritis in 1 patient each. The 150-mg/m2 dose was not tolerable. Doses were reduced for grade > or =3 toxicity in seven of eight patients at 90 mg/m2 daily. Three of nine patients at 45 mg/m2/day required dose reduction, two at the once-daily dose. Day 1 ATRA area under the plasma concentration versus time curve (AUC) increased with dose, and after 1-2 months of continued dosing, the AUC declined in 7 of 13 patients (54%) studied. ATRA AUC did not correlate with toxicity severity or frequency. Fifteen mg/m2/day every 8 h is a tolerable dose for 1 year in patients with treated SCCHN. ATRA pharmacokinetics did not correlate with toxicity.

Topics: Adult; Aged; Antineoplastic Agents; Area Under Curve; Carcinoma, Squamous Cell; Dose-Response Relationship, Drug; Exanthema; Female; Follow-Up Studies; Head and Neck Neoplasms; Headache; Humans; Hypertriglyceridemia; Male; Middle Aged; Mouth Mucosa; Neoplasm Staging; Stomatitis; Treatment Outcome; Tretinoin

Liarozole is a 1-substituted imidazole derivative that inhibits cytochrome P450 activity and increases endogenous plasma concentrations of retinoid acid (RA). We have previously demonstrated that RA down-modulates transforming growth factor (TGF)-alpha and epidermal growth factor receptor (EGFR) levels in head and neck squamous cell carcinoma by decreasing the transcription rate of these two genes. Previous reports suggest that RA receptor (RAR)-beta levels are down-modulated in head and neck cancer and are restored by RA therapy. Cellular RA-binding protein (CRABP)-II is up-regulated by RA and appears to modulate intracellular RA metabolism. In conjunction with a Phase I clinical trial, total intact RNA was extracted from oral cavity mucosa biopsied from 17 patients with advanced malignancies, before and after treatment with a 4-week course of liarozole. To analyze these limited quantities of total RNA (as little as 0.6 microg/sample), a quantitative reverse transcription-PCR assay was developed using delayed dropping of the 5' beta-actin primer to amplify the highly abundant beta-actin gene as an internal control. We used this method to determine the expression levels of TGF-alpha, EGFR, RAR-beta, and CRABP-II before and after treatment. There was a trend toward elevation of RAR-beta levels in oral mucosa after liarozole therapy (P = 0.107), whereas TGF-alpha, EGFR, and CRABP-II were not modulated by systemic liarozole treatment. These results suggest that liarozole may up-regulate RAR-beta in tissues from cancer patients and that expression levels of potential intermediate biomarkers may be determined in small tissue biopsies using a quantitative reverse transcription-PCR assay.

Topics: Actins; Antineoplastic Agents, Hormonal; Biomarkers; Carcinoma, Squamous Cell; DNA Primers; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel; ErbB Receptors; Humans; Imidazoles; Mouth Mucosa; Mouth Neoplasms; Receptors, Retinoic Acid; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor alpha; Tretinoin; Up-Regulation

Retinoids have been increasingly used since the mid-1960s for the treatment of leukoplakia and dysplasia of the head and neck. Studies of their use in the treatment of carcinomas of the head and neck, usually in combination with interferons, have also been published in recent years.. 30 patients (25 men, five women) with UICC stage IV were given adjunctive treatment with a combination of 3 x 3 million IU of interferon alfa SC weekly and 0.5 mg/kg body weight of 13-cis retinoic acid PO daily for a maximum duration of 6 months. The therapeutic benefits and side effects are reported here.. Therapy was completed as scheduled in 16 out of 30 patients. Reasons for stopping treatment: progressive disease (ten patients), side effects (four patients). 18 patients were tumor-free following treatment. 16 patients displayed a complete response one year after completion of adjunctive treatment. Retinoic-associated side effects observed included xerostomia (90%), dysphagia (67%), weight loss (50%), flush (50%) and cachexia (7%). Interferon-associated side effects included pyrexia and moderate hematological changes.. Adjunctive combination treatment with interferon alfa and 13-cis retinoic acid appears to be beneficial to patients with head and neck cancer. The side effects are moderate.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Combined Modality Therapy; Female; Follow-Up Studies; Head and Neck Neoplasms; Humans; Interferon-alpha; Male; Middle Aged; Neoplasm Recurrence, Local; Neoplasm Staging; Neoplasms, Second Primary; Tretinoin

Preclinical and clinical data support the study of retinoids and interferon-alpha (IFN-alpha) in advanced squamous cell carcinoma of the uterine cervix (SCC). This phase II randomized trial of the Southwest Oncology Group sought to estimate the response rate for IFN-alpha plus either 13-cis-retinoic acid (13cRA) or all-trans-retinoic acid (ATRA) in women with recurrent cervical SCC.. Eligibility for this trial required bidimensionally measurable locally recurrent or metastatic squamous or adenosquamous carcinoma of the uterine cervix; SWOG performance status of

Topics: Adult; Aged; Carcinoma, Squamous Cell; Female; Humans; Interferon-alpha; Isotretinoin; Middle Aged; Neoplasm Recurrence, Local; Tretinoin; Uterine Cervical Neoplasms

Although tobacco and alcohol use are the major determinants of upper aerodigestive tract carcinogenesis, not all smokers develop cancer. This phenomenon is due to individual variation in genetic susceptibility to carcinogens. One explanation may be differences in mutagen sensitivity (as measured by the in vitro bleomycin-induced mutagen sensitivity assay) in patients with squamous cell carcinoma of the upper aerodigestive tract. Antioxidant supplementation has also been shown to decrease DNA damage and thus may also inhibit carcinogenesis. In this study, we examined whether smoking, alcohol intake, and dietary antioxidant intake were correlated with mutagen sensitivity. The 612 patients evaluated are part of an ongoing multicenter Phase III trial of 13-cis retinoic acid for the prevention of second primary tumors. We found that patients with pharyngeal cancers were more likely than patients with oral cavity or larynx cancers to be mutagen sensitive. There were no significant differences in the distribution of mutagen sensitivity by sex or alcohol use. Never smokers were significantly more likely (61.1%) to be mutagen sensitive than current smokers (35.6%). Dietary consumption of the micronutrients alpha-carotene, beta-carotene, lutein, lycopene, and vitamin C was not correlated with mutagen sensitivity. Therefore, we suggest that mutagen sensitivity is an independent marker of cancer risk not affected by other known risk factors.

Topics: Adult; Aged; Alcohol Drinking; Antineoplastic Agents; Antioxidants; Carcinoma, Squamous Cell; Diet; Female; Genetic Predisposition to Disease; Head and Neck Neoplasms; Humans; Logistic Models; Male; Middle Aged; Mutagenesis; Mutagenicity Tests; Neoplasms, Second Primary; Risk Factors; Smoking; Tretinoin

Photodamaged skin typically displays lentigines, actinic keratoses, wrinkles, and textural alteration. Chemical peeling has been used to treat these, but few controlled studies have been performed to determine its efficacy.. Our purpose was to compare the efficacy of a medium-depth chemical peel with and without tretinoin before and after treatment.. Sixteen men with actinic damage including actinic keratoses were treated with a 40% trichloroacetic acid(TCA) chemical peel. Half were pretreated for 6 weeks with topical tretinoin; they also used tretinoin after the peel. Photographs were obtained at baseline and at 6 weeks and 6 months after treatment. Changes in specific features were rated by a panel of three examiners.. Some improvement was noted in all patients. More rapid and even frosting was observed in the patients pretreated with tretinoin. Solar lentigines, actinic keratoses, and skin texture were the features of photoaging most affected; wrinkles were least affected. No statistically significant difference was found between patients treated with TCA and tretinoin (before and after peel) and those with TCA alone.. A medium-depth chemical peel with 40% TCA alone produced moderate improvement in some manifestations of actinic damage but had little effect on wrinkles. Treatment with tretinoin before and after TCA did not significantly enhance the efficacy of the peel.

Topics: Administration, Cutaneous; Bacteria; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Chemexfoliation; Follow-Up Studies; Humans; Keratolytic Agents; Keratosis; Lentigo; Male; Patient Satisfaction; Photography; Premedication; Sebum; Skin; Skin Aging; Skin Neoplasms; Tretinoin; Trichloroacetic Acid

Renal transplant recipients experience a greatly increased frequency of neoplastic skin lesions, including aggressive squamous cell carcinomas. Recent reports suggest that high doses of systemic retinoids may exert a chemotherapeutic and chemoprophylactic effect. Similarly, topical retinoid, especially tretinoin, has also been shown to be anti-tumoragenic in various settings. Because of the serious toxicity of high-dose systemic retinoid, a protocol was developed that combined topical tretinoin with low-dose etretinate (10 mg daily) for the treatment of frequently occurring dysplastic skin lesions in renal transplant recipients. Seven patients elected to receive combined tretinoin and etretinate therapy, and 4 were treated with tretinoin alone. Clinical evaluations were performed monthly. By 3 months of therapy, 9 of 11 patients exhibited at least a 25% decrease in the number of neoplastic growths. After 6 months, 6 of 8 evaluable patients, including 2 of 3 individuals receiving tretinoin alone, exhibited at least a 50% decrease. Three of 4 patients on the combined regimen and 2 of 3 receiving tretinoin alone for at least 9 months, exhibited a significant decrease in the rate of development of new squamous cell cancers. At the start of treatment, epidermal specimens were almost completely devoid of Langerhans cells (CD1+ cells). Their density increased greatly and in proportion to the duration of therapy. Long term topical tretinoin with or without low-dose oral etretinate seems to be an effective regimen to suppress the development of new tumors and to reduce the numbers of existing lesions in renal transplant recipients.

Topics: Administration, Topical; Adult; Biopsy; Carcinoma, Squamous Cell; Dose-Response Relationship, Drug; Drug Therapy, Combination; Etretinate; Humans; Immunohistochemistry; Kidney Transplantation; Pilot Projects; Precancerous Conditions; Skin; Skin Neoplasms; Tretinoin

Between April 1993 and June 1994, 29 patients (pts) with unresectable, locally advanced, or metastatic non-small cell lung cancer were treated with a combination of p.o. trans-retinoic acid (TRA), 150 mg/m2/day, in three divided doses and s.c. IFN-alpha, 3 x 10(6) units/day. The age range was 41-80 years (median, 63 years). The Eastern Cooperative Oncology Group performance status was 0-1 (24 pts) and 2 (5 pts). Pts had advanced disease, refractory to conventional therapy (5 stage IIIB and 24 stage IV). Twenty-one pts had adenocarcinoma, six had squamous cell carcinoma, and two had large cell carcinoma. Only 3 pts completed 8 weeks of treatment, requiring neither interruption nor dose modification. Fatigue occurred in 88% of pts. A syndrome complex consisting of dry oral and nasal mucosa, recurrent sinus infections, and epistaxis occurred in 64% of pts. Grade II/III dermatitis was seen in 52%. Severe scrotal dermatitis was seen in 7 pts (47% of 15 males). Hypertriglyceridemia was moderate/severe in 11 pts, and 3 pts required gemfibrozil for levels up to 1660 mg/dl. Hematological toxicity was not encountered, and none of the pts had leukocytosis. One pt died with complications of myocardial infarction while on TRA/IFN-alpha. Twenty-five pts had more than 2 weeks of treatment and are evaluable for response; two pts died early with complications of cancer, and two pts declined to continue after only 3 and 5 days of treatment. Final assessment of response was by accepted clinical and radiological criteria at 8 weeks. There have been four objective responses: complete response, 2 (18+ and 17 months) and partial response, 2 (7 and 14 months). Responses were observed in all histologies. Combined differentiation treatment with TRA/IFN-alpha has modest but objective activity in non-small cell lung cancer. Toxicity is considerable. Additional studies to elucidate the biological basis of TRA/IFN-alpha and to define prognostic parameters predicting response are needed.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Large Cell; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Female; Humans; Interferon-alpha; Lung Neoplasms; Male; Middle Aged; Neoplasm Staging; Radiography; Tretinoin

Orally administered all-trans-retinoic acid (all-trans-RA) can induce complete remission in a high proportion of patients with acute promyelocytic leukemia. A previous pharmacokinetic study in patients with acute promyelocytic leukemia raised the possibility that the absorption of orally administered all-trans-RA is a saturable process that would have significant clinical impact on dosing strategies.. This study was specifically designed to examine the saturability of all-trans-RA absorption by measuring the effect of doubling the oral dose of all-trans-RA on plasma drug concentration in patients receiving long-term oral therapy.. Six patients with solid tumors received oral doses of 10-mg gelatin capsules of all-trans-RA. Patients were studied on 2 consecutive days after they received 28 days of all-trans-RA administered as two daily 78-mg/m2 doses. The study assigned the patients to two groups. Three patients took a 156-mg/m2 dose on day 28 and a 78-mg/m2 dose on day 29; the other three patients took the lower dose on day 28 and the double dose on day 29. Blood samples for the determination of all-trans-RA plasma concentration were obtained at 30-minute intervals starting just prior to drug administration and continuing for a total of 7 hours. The plasma concentration of all-trans-RA was measured by high-performance liquid chromatography.. Plasma concentrations following an oral dose of all-trans-RA were highly variable, with peak concentrations ranging from 0.07 to 1.2 microM for the 78-mg/m2 dose level. Doubling the dose from 78 to 156 mg/m2 increased plasma concentration in all six patients, but the increase was unpredictable and not related to dose, ranging from less than a 1.2-fold to more than a 10-fold increase.. The current study does not support the hypothesis that the gastrointestinal absorption of all-trans-RA involves a saturable process but instead suggests that absorption is highly variable among patients. This wide interpatient variability suggests that pharmacokinetic drug monitoring may have an important role in the management of patients receiving all-trans-RA.

Topics: Adenocarcinoma; Administration, Oral; Adult; Aged; Biological Availability; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Chromatography, High Pressure Liquid; Colorectal Neoplasms; Dose-Response Relationship, Drug; Esophageal Neoplasms; Female; Half-Life; Humans; Intestinal Absorption; Lung Neoplasms; Male; Middle Aged; Skin Neoplasms; Time Factors; Tretinoin

Retinoids, the analogs of vitamin A, are active in vitro and in vivo against squamous cell carcinoma in animals and against certain epithelial precancers and cancers in humans. These data led us to design a prospective, multi-institutional, randomized phase II trial of isotretinoin in advanced head and neck squamous cell carcinoma. We randomly assigned 40 patients to receive isotretinoin or methotrexate, the best-studied and most active single agent for this disease. Overall, the study patients had extremely poor prognoses, i.e., low performance statuses and recurring disease after surgery and/or irradiation. Three objective responses (16%), including one complete response, occurred in the 19 evaluable isotretinoin-treated patients. Only one minor response (5%) occurred in the methotrexate-treated group. Toxicity occurred with both drugs, but was manageable and never life threatening in the retinoid group. These results and the established activity of retinoids in oral leukoplakia (a precursor of head and neck cancer) indicate the need for further study of this class of drugs in head and neck cancer.

Topics: Adult; Aged; Carcinoma, Squamous Cell; Drug Evaluation; Female; Head and Neck Neoplasms; Humans; Isotretinoin; Male; Methotrexate; Middle Aged; Random Allocation; Tretinoin

To confirm reports that skin cancer can be prevented with retinoids, we conducted a three-year controlled prospective study of oral isotretinoin (also called 13-cis retinoic acid) in five patients with xeroderma pigmentosum who had a history of multiple cutaneous basal-cell or squamous-cell carcinomas. Patients were treated with isotretinoin at a dosage of 2 mg per kilogram of body weight per day for two years and then followed for an additional year, without the drug. Before, during, and after treatment, biopsies of all suspicious lesions were performed, and skin cancers were surgically removed. The patients had a total of 121 tumors (mean, 24; range, 8 to 43) in the two-year interval before treatment. During two years of treatment with isotretinoin, there were 25 tumors (mean, 5; range, 3 to 9), with an average reduction in skin cancers of 63 percent (P = 0.019). After the drug was discontinued, the tumor frequency increased a mean of 8.5-fold (range, 2- to 19-fold) over the frequency during treatment (P = 0.007). Although all patients experienced mucocutaneous toxic effects, and triglyceride, liver-function, or skeletal abnormalities developed in some, high-dose oral isotretinoin was effective in the chemoprophylaxis of skin cancers in patients with xeroderma pigmentosum.

Topics: Administration, Oral; Adolescent; Adult; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Child; Clinical Trials as Topic; Female; Humans; Isotretinoin; Male; Prospective Studies; Skin Neoplasms; Tretinoin; Xeroderma Pigmentosum

Ten cats with a total of 15 cancerous or precancerous lesions were examined for clinical response to and histopathologic changes after treatment with 13-cis-retinoic acid. Before treatment was started, the lesions were graded according to clinical severity and biopsied for histopathologic examination. Serum samples were prepared for determining vitamin A concentrations. For comparison, serum vitamin A concentrations in 10 clinically healthy cats were determined. 13-cis-Retinoic acid (approx 3.0 mg/kg) was given to affected cats once a day for an average of 68 days. At the completion of the therapeutic trial, additional biopsy tissues were obtained for histopathologic examination, and serum was assayed for 13-cis-retinoic acid. Of the 15 lesions examined, only 1 showed partial clinical and microscopic improvement during the therapy period. The mean serum vitamin A concentration of the affected cats was not statistically different from that of the 10 healthy cats. The results of this trial indicated that 13-cis-retinoic acid used at this dosage, daily frequency, and duration did not have therapeutic efficacy for squamous cell carcinomas or preneoplastic lesions in the cat and that the mean serum vitamin A concentration did not differ between the affected cats and clinically healthy cats.

Topics: Animals; Carcinoma, Squamous Cell; Cat Diseases; Cats; Clinical Trials as Topic; Head and Neck Neoplasms; Isotretinoin; Precancerous Conditions; Tretinoin; Vitamin A

Forty-six evaluable patients with advanced squamous cell carcinoma of the lung were treated in a randomized fashion with either etretinate, CCNU and bleomycin in combination (ECB) or with CCNU and bleomycin (CB). There were no complete and no partial responses. Minor responses occurred in 5 patients (24%) with ECB and in 3 patients (12%) with CB independently of histological grade. No change was observed in 9 patients (43%) with ECB and in 13 patients (52%) with CB. There was no survival difference between the two groups. Reversible side-effects of skin and mucous membranes were more frequent under ECB. The antitumor efficacy of CB is marginal and could not be improved by the addition of the vitamin-A-derivative etretinate.

Topics: Adult; Aged; Bleomycin; Carcinoma, Squamous Cell; Drug Therapy, Combination; Etretinate; Female; Humans; Lomustine; Lung Neoplasms; Male; Middle Aged; Nitrosourea Compounds; Prognosis; Tretinoin

The incidence of keratinocyte carcinomas (KCs), comprising basal and squamous cell carcinomas, is rising in the United States. Chemoprevention is one modality by which patients can reduce the incidence of KCs.. We performed a retrospective review of 327 patients who employed a combination of imiquimod 5% cream, 5-fluorouracil 2% solution, and tretinoin 0.1% cream in a field therapy regimen over the face/ears or scalp for chemoprevention.. Patients had dramatically lower odds of having KCs in the treatment location (face/ears or scalp) in the one-year period after field treatment than in the one-year period preceding field treatment (OR=0.06, 95% CI: [0.02, 0.15]). Patients were also at lower odds of having KCs in non-treated areas the year after field treatment than in the year preceding it (OR=0.25, 95% CI: [0.14, 0.42]). Additionally, fewer cryotherapy sessions were performed for actinic keratoses in the treatment areas in the year after treatment (mean=1.5, SD=1.21) than the year preceding treatment (mean=2.3, SD=0.99; t=11.68, P<0.001).. A combination of imiquimod 5% cream, 5-fluorouracil 2% solution, and tretinoin 0.1% cream were effective at reducing the incidence of new KCs for at least one year. Individualized treatment application frequency allowed for increased patient adherence. Prospective studies evaluating combination topical treatments for chemoprevention of KCs are needed to further assess the treatment effects found in this study. J Drugs Dermatol. 2023;22(5): doi:10.36849/JDD.7334.

Topics: Carcinoma, Squamous Cell; Chemoprevention; Fluorouracil; Humans; Imiquimod; Keratinocytes; Keratosis, Actinic; Prospective Studies; Treatment Outcome; Tretinoin

With the growing incidence of cutaneous squamous cell carcinoma (CSCC), the treatment-resistant invasive CSCC should be taken seriously. Retinoic acid receptor β (RARβ) functions as a tumor suppressor gene and is associated with the proliferation inhibition to retinoic acid. Demethylase TET2 directed epigenetic landscape contributes to cell malignant transform and is involved in therapeutic resistance in tumors. Whether aberrant TET2 participated in the deficient RARβ remains largely unknown. Hereby, we identified the aberrant-TET2 directed epigenetic landscape contribute to the deficient RARβ in CSCC.. The immunohistochemistry was used to detect the expression of RARβ and TET2. The bisulfite sequencing PCR was used to detect the RARβ promoter methylation. Plasmid transfection was used to upregulate TET2 in CSCC cells. Stable overxpressed TET2 cells were used to detect the effect of TET2 on RARβ and drug sensitivity in the CCSC.. We observed RARβ decreased with promoter hypermethylation in CSCC and aberrant TET2 associated with deficient RARβ. We upregulated TET2 could reverse promoter hypermethylation and showed a significantly increased expression of RARβ, which enhanced the sensitivity of tumor cells to retinoic acid treatment.. Aberrant TET2 leaded to the hypermethylation of RARβ promoter, which contributed to the deficient RARβ in CSCC. While reversing the hypermethylation of the RARβ promoter by recovering the TET2 could enhance tumor cells to be sensitive to retinoic acid.

Topics: Carcinoma, Squamous Cell; Dioxygenases; DNA Methylation; DNA-Binding Proteins; Epigenesis, Genetic; Humans; Receptors, Retinoic Acid; Skin Neoplasms; Tretinoin

Minimally invasive alternative approaches to treat non-melanoma skin cancers remain limited and unproven.. We aim to assess the efficacy of varying combinations of anti-tumor agents—imiquimod 5% cream, 5-fluorouracil 2% solution, and tretinoin 0.1% cream—with brief cryotherapy in treating non-melanoma skin cancers.. This retrospective study included 690 cases of non-melanoma skin cancers in 480 patients who received a diagnosis of a basal cell carcinoma or squamous cell carcinoma during a ten-year period. During treatment period, patients applied 30 applications of one of three combinations (imiquimod/tretinoin, 5-fluorouracil/tretinoin, or imiquimod/5-fluorouracil/tretinoin) and had cryotherapy every 2 weeks. Each patient had a clinical examination at least three years post-treatment or documented treatment failure. Clearance was defined by a lack of persistence or recurrence for 3 years following the completion of treatment. The likelihood of lesion clearance was evaluated using multivariable logistic regression analysis.. A total of 186 cases (97; basal cell carcinoma and 89; squamous cell carcinoma) in 133 patients [37% women and 63% men; median (interquartile range) age, 77 (69, 83) years] met the inclusion criteria. Multivariable logistic regression analysis adjusting for clinical and lesion variables demonstrated that, relative to the imiquimod/5-fluorouracil/tretinoin treatment approach, imiquimod/ tretinoin (odds ratio, 0.05; 95% confidence interval, 0.00-0.99) and 5-fluorouracil/tretinoin (0.02; 0.00–0.45) were associated with lower likelihoods of lesion clearance. Likewise, morpheaform basal cell carcinoma had a lower probability of clearance (0.05; 0.00–0.72).. The combination of imiquimod/5-fluorouracil/tretinoin with cryotherapy had high clearance rates and was the most effective treatment regimen. J Drugs Dermatol. 2021;20(3):260-267. doi:10.36849/JDD.5427.

Topics: Administration, Cutaneous; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Combined Modality Therapy; Cost-Benefit Analysis; Cryotherapy; Female; Fluorouracil; Humans; Imiquimod; Male; Middle Aged; Neoplasm Recurrence, Local; Retrospective Studies; Skin Neoplasms; Treatment Outcome; Tretinoin

Epigenetic silencing of retinoic acid (RA) signaling-related genes have been linked with the pathogenesis and clinical outcome in oral squamous cell carcinoma (OSCC) carcinogenesis. However, the precise mechanisms underlying the abnormal silencing of RA signaling-related genes in OSCC have not been well investigated.. Using combined analysis of genome-wide gene expression and methylation profile from 40 matched normal-tumor pairs of OSCC specimens, we found a set of retinoid signaling related genes are frequently hypermethylated and downregulated in OSCC patient samples, including alcohol dehydrogenase, iron containing 1 (ADHFE1) and aldehyde dehydrogenase 1 family, member A2 (ALDH1A2), which are the important rate-limiting enzymes in synthesis of RA. The expression of ADHFE1 and ALDH1A2 in OSCC patients was determine by quantitative real-time PCR (qRT-PCR) and immunohistochemistry. The binding sites of miR-30a and miR-379 with DNA methyltransferase 3B (DNMT3B) were predicted using a series of bioinformatic tools, and validated using dual luciferase assay and Western blot analyses. The functions of miR-30a, miR-379, and DNMT3B were accessed by growth and colony formation analyses using gain- and loss-of-function approaches. Chromatin immunoprecipitation (ChIP) was performed to explore the molecular mechanisms by arecoline and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) treatment.. We demonstrated that deregulated miR-30a and miR-379 could represent a mechanism for the silencing of ADHFE1 and ALDH1A2 in OSCC through targeting DNMT3B. Ectopic expression of miR-30a and miR-379 could induce re-expression of methylation-silenced ADHFE1 and ALDH1A2, and lead to growth inhibition in oral cancer cells. Furthermore, the dysregulation of the miRNAs and DNMT-3B may result from exposure to tobacco smoking and betel quid chewing.. Our results demonstrate that tobacco smoking and betel quid chewing could repress miR-30a and miR-379, which upregulate the DNMT3B expression, in turn, lead to the hypermethylation of ADHFE1 and ALDH1A genes, consequently, promote the oncogenic activity. These findings highlight the potential use of retinoids in combination with epigenetic modifiers for the prevention or treatment of oral cancer.

Topics: Alcohol Oxidoreductases; Aldehyde Dehydrogenase 1 Family; Arecoline; Carcinogenesis; Carcinoma, Squamous Cell; Cell Line, Tumor; DNA (Cytosine-5-)-Methyltransferases; DNA Methyltransferase 3B; Gene Expression Regulation, Neoplastic; Gene Silencing; Humans; Metabolic Networks and Pathways; MicroRNAs; Mitochondrial Proteins; Mouth Neoplasms; Nitrosamines; Retinal Dehydrogenase; Tretinoin

Topics: Animals; B7-H1 Antigen; Carcinoma, Squamous Cell; CD8-Positive T-Lymphocytes; Cell Line, Tumor; Mice; Mice, Inbred C3H; Mouth Neoplasms; Nanoparticles; Polyethylene Glycols; Squamous Cell Carcinoma of Head and Neck; Tretinoin; Tumor Microenvironment

To gain a greater understanding of oral squamous cell carcinoma (OSCC) we investigated the actions of all-trans-retinoic acid (RA; a retinoid), bexarotene (a pan-RXR agonist), and forkhead box (FOX) transcription factors in human OSCC-derived cell lines. RA and bexarotene have been shown to limit several oncogenic pathways in many cell types. FOXO proteins typically are associated with tumor suppressive activities, whereas FOXM1 acts as an oncogene when overexpressed in several cancers. RA and/or bexarotene increased the transcript levels of FOXO1, FOXO3A, and TRAIL receptors; reduced the transcript levels of FOXM1, Aurora kinase B (AURKB), and vascular endothelial growth factor A (VEGFA); and decreased the proliferation of OSCC-derived cell lines. Also, RA and/or bexarotene influenced the recruitment of FOXO3A and FOXM1 to target genes. Additionally, FOXM1 depletion reduced cell proliferation, decreased transcript levels of downstream targets of FOXM1, and increased transcript levels of TRAIL receptors. Overexpression of FOXO3A decreased proliferation and increased binding of histone deacetylases (HDACs) 1 and 2 at the FOXM1, AURKB, and VEGFA promoters. This research suggests novel influences of the drugs RA and bexarotene on the expression of FOXM1 and FOXO3A in transcriptional regulatory pathways of human OSCC.

Topics: Antineoplastic Agents; Bexarotene; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Forkhead Box Protein M1; Forkhead Box Protein O3; Gene Expression; Gene Knockdown Techniques; Histone Deacetylases; Humans; Mouth Neoplasms; Promoter Regions, Genetic; Retinoids; RNA, Messenger; Tretinoin

Oral squamous cell carcinoma (OSCC), which may arise from oral dysplasia, is one of the most prevalent cancers around the world. In recent years, all-trans retinoic acid (ATRA) has shown great potential in cancer treatment. However, the molecular mechanism for the anti-tumor effects of ATRA remains unclear.. After treated with ATRA, inhibition of cell proliferation of OSCC and oral dysplasia cell lines, CAL27 and DOK, respectively, was analyzed by a Cell Counting Kit-8 (CCK8) assay. The cell cycle arrest, cell apoptosis induction, and PD-L1 expression level were measured by flow cytometry. A small molecular inhibitor was utilized to block STAT3 pathway, and the related proteins expression was measured by Western Blot.. The present study demonstrated that ATRA inhibited cell proliferation at 5-75 μmol/L, arrested cell cycle at S and G2-phase, induced apoptosis effect in OSCC, and oral dysplasia cell line, CAL27 and DOK, respectively. ATRA led to inhibition of p-STAT3, p-JAK2, increased the level of p-ERK, and significantly decreased the PD-L1 expression. Moreover, targeting STAT3 signaling increased (P < .001) the level of cleaved caspase-3 and effectively (P < .001) decreased the expression of cyclin A2 and PD-L1. The effect of ATRA on cell growth inhibition, apoptosis induction, and PD-L1 expression decrease was significantly (P < .05) enhanced after the STAT3 signaling blockade.. These findings suggested that ATRA-induced anti-tumor effects and downregulated PD-L1 expression via STAT3 signaling inhibition in both OSCC and oral dysplasia.

Topics: Apoptosis; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Humans; Mouth Neoplasms; Signal Transduction; STAT3 Transcription Factor; Tretinoin

Esophageal squamous cell carcinoma (ESCC) is the second common cancer in Henan province and is well-known for aggressiveness and dismal prognosis. Adjuvant therapies, chemotherapy, radiotherapy and endoscopic treatment have not improved survival rates in patients with late stage esophageal carcinoma. All-trans retinoic acid (ATRA) is the active ingredient of Vitamin A and affects a wide spectrum of biological processes including development, growth, neural function, immune function, reproduction, and vision. It is one of the most potent therapeutic agents used for treating cancers, especially lung adenocarcinomas. ATRA inhibits metastatic potential and angiogenesis in several tumor models. We investigated the effects of ATRA on the expression of angiopoietin 1 (Ang-1), angiopoietin 2 (Ang-2) and receptor Tie-2 in EC1 cells in vitro. We also assessed the growth and migration of EC1 cells in vitro. ATRA treatment caused 29.5% and 40.3% reduction of the growth of EC1 cells after 24 hours and 48 hours, relative to the control. ATRA plus fluorouracil treatment reduced the viability more strongly than either drug alone, indicating an additive effect. Moreover, ATRA decreased EC1 migration by 87%. Furthermore, ATRA treatment led to a marked decrease of the transcript levels of Ang-1, Ang-2, Tie-2, VEGF, and VEGF receptors, as assessed by real-time RT-PCR. Importantly, the protein levels of Ang-1, Ang-2 and Tie-2 were reduced by ATRA treatment. In vivo, we found ATRA treatment suppressed the tumor growth and improved the cachexia of mice. Importantly, ATRA treatment decreased the expression of CD31, Ang-1, Ang-2 and Tie-2 in subcutaneous tumors of EC1 cells. Collectively, our findings demonstrate that ATRA exhibits a dose- and temporal-dependent effect on the metastatic behavior, suppresses the angiopoietin-Tie2 pathway and inhibits angiogenesis and the progression of xenograft tumors of EC1 cells.

Topics: Angiopoietin-1; Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Proliferation; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Female; Fluorouracil; Humans; Mice; Mice, Inbred BALB C; Neoplasm Metastasis; Neovascularization, Pathologic; Platelet Endothelial Cell Adhesion Molecule-1; Receptor, TIE-2; Receptors, Vascular Endothelial Growth Factor; Tretinoin; Vascular Endothelial Growth Factor A; Vesicular Transport Proteins

To determine the expression profile and potential roles of CD24 in oral squamous cell carcinoma and explore the values of CD24 function as a potential target of clinical therapy.. Semi-quantitative immunohistochemistry was used to construct the expression profile of CD24 in 78 human oral tissues and 59 Hamster buccal pouch tissues. Real-time RT-PCR and Western blot were used to analyze the CD24 expression levels in oral DOK4 cells, oral cancer CAL-27 and WSU-HN6 cells. Then these two cancer cell lines were selected to evaluate the effect of all-trans retinoic acid (ATRA) and CD24 antibody on CD24 expression, and the proliferation and tumorsphere formation capacity of these two cell lines.. CD24 expression was found significantly elevated in both human and animal tissues compared with normal and benign tissues (P<0.05), as well as in oral cancer CAL-27 and WSU-HN6 cells compared with DOK cells (P<0.05). CAL-27 and WSU-HN6 cells possess increased proliferative and specific tumorsphere formation capability compared with DOK cells (P<0.05). Both ATRA and CD24 antibody were able to effectively inhibit the proliferation and tumorsphere formation of CAL-27 and WSU-HN6 cells (P<0.05). Among them ATRA at least involved partially in the proliferation by down-regulating the CD24 expression (P<0.05), while CD24 antibody blocking had no effect on the CD24 expression.. CD24 was upregulated in oral cancer and functioned as a potential factor that promoted the proliferation and tumorsphere formation of CAL-27 and WSU-HN6 cells. Both ATRA and CD24 antibody might effectively inhibit the proliferation and tumorsphere formation of CAL-27 and WSU-HN6 cells and function as a potential therapy target.

Topics: Animals; Carcinoma, Squamous Cell; CD24 Antigen; Cell Line, Tumor; Cricetinae; Down-Regulation; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Mouth Mucosa; Mouth Neoplasms; Tretinoin

Epidermodysplasia verruciformis (EV) is a rare genetic disorder characterized by widespread human papillomavirus (HPV) associated lesions and an increase susceptibility to cutaneous malignancies. A host of medications traditionally used to treat warty lesions have been used with variable results and limited success. To our knowledge, we describe the first reported case of a patient with Imiquimod resistant EV successfully treated with topical ingenol mebutate (Picato).. A patient with a 5 year history of EV failed to respond to a 6 week course of 5% imiquimod on the forehead and was subsequently treated with a 3 day course of 0.015% Picato gel which resulted in significant clinical improvement. A one month follow-up examination showed no reoccurrence of the lesions with the patient reporting continued satisfaction of the outcome.. Our case provides insight into the potential use of ingenol mebutate for EV patients unresponsive to traditional medical treatments.

Topics: Acitretin; Adult; Aminoquinolines; Antineoplastic Agents; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Diterpenes; Drug Resistance; Epidermodysplasia Verruciformis; Female; Gels; Humans; Imiquimod; Keratolytic Agents; Rare Diseases; Skin Neoplasms; Treatment Outcome; Tretinoin

Cancer stem cells (CSCs) drive tumour spread and therapeutic resistance, and can undergo epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET) to switch between epithelial and post-EMT sub-populations. Examining oral squamous cell carcinoma (OSCC), we now show that increased phenotypic plasticity, the ability to undergo EMT/MET, underlies increased CSC therapeutic resistance within both the epithelial and post-EMT sub-populations. The post-EMT CSCs that possess plasticity exhibit particularly enhanced therapeutic resistance and are defined by a CD44(high)EpCAM(low/-) CD24(+) cell surface marker profile. Treatment with TGFβ and retinoic acid (RA) enabled enrichment of this sub-population for therapeutic testing, through which the endoplasmic reticulum (ER) stressor and autophagy inhibitor Thapsigargin was shown to selectively target these cells. Demonstration of the link between phenotypic plasticity and therapeutic resistance, and development of an in vitro method for enrichment of a highly resistant CSC sub-population, provides an opportunity for the development of improved chemotherapeutic agents that can eliminate CSCs.

Topics: Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; CD24 Antigen; Cell Line; Cell Line, Tumor; Drug Resistance, Neoplasm; Epithelial Cell Adhesion Molecule; Epithelial-Mesenchymal Transition; Female; Humans; Hyaluronan Receptors; Male; Mice; Mice, Inbred NOD; Mice, SCID; Mouth Neoplasms; Neoplastic Stem Cells; Phenotype; Thapsigargin; Transforming Growth Factor beta; Tretinoin

Topics: Antineoplastic Combined Chemotherapy Protocols; Arsenic Trioxide; Arsenicals; Carcinoma, Squamous Cell; Humans; Immunocompromised Host; Kidney Transplantation; Leukemia, Promyelocytic, Acute; Lung Transplantation; Male; Middle Aged; Neoplasms, Second Primary; Oxides; Postoperative Complications; Skin Neoplasms; Tretinoin

Cis-diamminedichloridoplatinum(II)(CDDP)-based combination chemotherapy is frequently used in gastrointestinal cancer. The synergistic mechanism of all-trans retinoic acid (ATRA), cisplatin (CDDP) and 5-fluorouracil (5-FU) in combination remains unclear. Despite their potent antitumor properties, resistance to CDDP and 5-FU develops frequently in tumors. To clarify this mechanism, we determined the sensitivity to each drug and their combination in two gastrointestinal cancer stem cells (CSCs) subpopulation. Here, we report the identification and separation of CD44(+) cells from human gastric carcinoma (AGS) and human esophageal squamous cell carcinoma (KYSE-30) cancer cell lines by magnetic activated cell sorting (MACS). We allowed the CD44(±) cells to grow 6 days at a subtoxic concentration of ATRA and then treated with different concentration of CDDP and 5-FU for 24h. The cytotoxicity was examined by cell proliferation MTT assay. Additionally, AO/EB staining was used for detection of apoptotic cells. In order to determine whether the growth inhibition was also associated with changes in cell cycle distribution, cell cycle analysis was performed using flow cytometry. Low concentration of ATRA (1μM, 6days) followed by 5-FU and CDDP was found to be more effective than either drugs alone, thus resulting in synergistic cytotoxicity in Kyse-30 and AGSCD44(±) cells. Furthermore, there was an indication that the combination of ATRA with 5FU and CDDP caused an increase in cell cycle arrest in G2/M and G0/G1. We conclude that low concentration of ATRA enhances the cytotoxicity of CDDP and 5FU by facilitating apoptosis and cell cycle arrest in gastrointestinal CSCs and provide a rational basis for the design of novel, well-tolerated CDDP- and 5FU-based chemotherapy in human gastrointestinal carcinoma.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Carcinoma, Squamous Cell; Cell Cycle; Cell Cycle Checkpoints; Cell Line, Tumor; Cisplatin; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Drug Synergism; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Flow Cytometry; Fluorouracil; Humans; Hyaluronan Receptors; Neoplastic Stem Cells; Stomach Neoplasms; Tretinoin

Skin cancer burden is significant as treatment costs have skyrocketed to $8.1 million annually and some forms metastasize, such as cutaneous squamous cell carcinoma (cSCC) and melanoma. cSCC is caused by altered growth factor signaling induced by chemical carcinogens, ultraviolet light (UV) exposure, and infections with papillomaviruses (PVs). One of the few options for preventing cSCC in high-risk patients is oral retinoids. While much is understood about retinoid treatments and metabolism in mouse models of chemically and UV exposure induced cSCC, little is known about the role of retinoids in PV-induced cSCC. To better understand how retinoid metabolism is altered in cSCC, we examined the expression of this pathway in the newly discovered mouse papillomavirus (MmuPV1), which produces trichoblastomas in dorsal skin but not cSCC. We found significant increases in a rate-limiting enzyme involved in retinoic acid synthesis and retinoic acid binding proteins, suggestive of increased RA synthesis, in MmuPV1-induced tumors in B6.Cg-Foxn1(nu)/J mice. Similar increases in these proteins were seen after acute UVB exposure in Crl:SKH1-Hr(hr) mice and in regressing pre-cancerous lesions in a chemically-induced mouse model, suggesting a common mechanism in limiting the progression of papillomas to full blown cSCC.

Topics: Animals; Carcinoma, Squamous Cell; Disease Models, Animal; Female; Immunohistochemistry; Mice; Oligonucleotide Array Sequence Analysis; Papillomaviridae; Papillomavirus Infections; Skin Neoplasms; Transcriptome; Tretinoin

An inverse correlation between expression of the aldehyde dehydrogenase 1 subfamily A2 (ALDH1A2) and gene promoter methylation has been identified as a common feature of oropharyngeal squamous cell carcinoma (OPSCC). Moreover, low ALDH1A2 expression was associated with an unfavorable prognosis of OPSCC patients, however the causal link between reduced ALDH1A2 function and treatment failure has not been addressed so far.. Serial sections from tissue microarrays of patients with primary OPSCC (n = 101) were stained by immunohistochemistry for key regulators of retinoic acid (RA) signaling, including ALDH1A2. Survival with respect to these regulators was investigated by univariate Kaplan-Meier analysis and multivariate Cox regression proportional hazard models. The impact of ALDH1A2-RAR signaling on tumor-relevant processes was addressed in established tumor cell lines and in an orthotopic mouse xenograft model.. Immunohistochemical analysis showed an improved prognosis of ALDH1A2(high) OPSCC only in the presence of CRABP2, an intracellular RA transporter. Moreover, an ALDH1A2(high)CRABP2(high) staining pattern served as an independent predictor for progression-free (HR: 0.395, p = 0.007) and overall survival (HR: 0.303, p = 0.002), suggesting a critical impact of RA metabolism and signaling on clinical outcome. Functionally, ALDH1A2 expression and activity in tumor cell lines were related to RA levels. While administration of retinoids inhibited clonogenic growth and proliferation, the pharmacological inhibition of ALDH1A2-RAR signaling resulted in loss of cell-cell adhesion and a mesenchymal-like phenotype. Xenograft tumors derived from FaDu cells with stable silencing of ALDH1A2 and primary tumors from OPSCC patients with low ALDH1A2 expression exhibited a mesenchymal-like phenotype characterized by vimentin expression.. This study has unraveled a critical role of ALDH1A2-RAR signaling in the pathogenesis of head and neck cancer and our data implicate that patients with ALDH1A2(low) tumors might benefit from adjuvant treatment with retinoids.

Topics: Aldehyde Dehydrogenase 1 Family; Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Adhesion; Cell Line, Tumor; Cell Proliferation; Head and Neck Neoplasms; Humans; Kaplan-Meier Estimate; Mice, Nude; Neoplasm Transplantation; Phenotype; Prognosis; Proportional Hazards Models; Receptors, Retinoic Acid; Retinal Dehydrogenase; Treatment Outcome; Tretinoin

All-trans retinoic acid (ATRA) has been tried for the treatment and prevention of a number of epithelial cancers. However, the precise mechanism by which ATRA inhibits the growth of cutaneous squamous cell carcinoma (cSCC) remains elusive.. To determine the suppressive effects of ATRA on the human cSCC cell line SCL-1, and explore the possible mechanisms involved.. SCL-1 cells were treated with ATRA, then cell proliferation was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, while apoptosis and cell cycle progression were analysed by flow cytometry. Protein levels of cell-cycle regulatory proteins and the activation of extracellular signal-regulated kinase (ERK) and Jun kinase (JNK) were detected by western blotting analysis. Transcriptional activity of activator protein (AP)-1 was examined by luciferase reporter assay.. ATRA inhibited the proliferation of SCL-1 cells and had modest proapoptotic effects. ATRA also induced G1 cell-cycle arrest, inhibited the expression of cyclin D1/cyclin-dependent kinase (CDK)4 and cyclinE/CDK2, and increased the expression of the cyclin-dependent kinase inhibitors p21 and p27. In addition, ATRA significantly decreased the phosphorylation of ERK1/2 and JNK1/2, and inhibited AP-1 transcriptional activity.. ATRA induces cell-cycle arrest in human cSCC cells by inhibiting the mitogen-activated protein kinase (MAPK)-AP1 pathway, and could be effective in the prevention and chemotherapy of human cSCC.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Cycle Checkpoints; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Humans; Mitogen-Activated Protein Kinase 1; Skin Neoplasms; Tretinoin

A fundamental goal in cancer biology is to identify the cells and signalling pathways that are keys to induce tumour regression. Here we use a spontaneously self-regressing tumour, cutaneous keratoacanthoma (KAs), to identify physiological mechanisms that drive tumour regression. By using a mouse model system that recapitulates the behaviour of human KAs, we show that self-regressing tumours shift their balance to a differentiation programme during regression. Furthermore, we demonstrate that developmental programs utilized for skin hair follicle regeneration, such as Wnt, are hijacked to sustain tumour growth and that the retinoic acid (RA) signalling pathway promotes tumour regression by inhibiting Wnt signalling. Finally, we find that RA signalling can induce regression of malignant tumours that do not normally spontaneously regress, such as squamous cell carcinomas. These findings provide new insights into the physiological mechanisms of tumour regression and suggest therapeutic strategies to induce tumour regression.

Topics: Animals; Carcinoma, Squamous Cell; Disease Models, Animal; Hair Follicle; Keratoacanthoma; Mice; Remission, Spontaneous; Skin Neoplasms; Stem Cells; Tretinoin; Wnt Signaling Pathway

Retinoic acid (RA) and its analogues (retinoids) are promising agents in skin cancer prevention following either topical application or oral administration. However, long-term in vivo effects of RA on chemically induced hyperplastic epidermal foci in adult mouse skin have also been described, casting some doubt with regard to its chemopreventive activity.. To characterize chemically induced skin tumours and to investigate the in vivo long-term action and preventive effect of RA on adult mouse skin carcinogenesis.. Fifty-six adult Naval Medical Research Institute mice, exposed (n = 28) or not exposed (n = 28) to RA in utero.. Mice were treated with a standard two-stage skin carcinogenesis protocol, which included an initiating application of 7,12-dimethylbenz(a)anthracene followed by promotion with 12-O-tetradecanoylphorbol 13-acetate.. Retinoic acid administered to pregnant mice showed a long-term inhibitory action on cell differentiation and development of chemically induced tumours on the adult skin of their offspring, as well as a stimulatory effect on cell proliferation and expression of an early marker of malignant progression (keratin 13).. The results suggest that RA exposure in utero confers long-lasting effects on adult mouse skin carcinogenesis. These include chemopreventive activity (reduced number of tumours), as well as enhancement of squamous papilloma progression, which appears to be due to enhanced keratinocyte proliferation and suppression of epidermal maturation. The clinical significance of these findings is not known for other routes of RA administration at this time.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Antineoplastic Agents; Carcinogens; Carcinoma, Squamous Cell; Drug Administration Schedule; Female; Keratoacanthoma; Male; Mice; Papilloma; Pregnancy; Skin Neoplasms; Tetradecanoylphorbol Acetate; Treatment Outcome; Tretinoin

Retinoic acid (RA) is a critical regulator of cell differentiation, proliferation, and apoptosis in various cell types. Recently, the RA-metabolizing enzyme CYP26A1 (cytochrome P450, family 26, subfamily A, polypeptide 1) has been shown to have an oncogenic function in breast carcinogenesis. However, the relevance of elevated CYP26A1 expression in human cancers remains to be clarified.. We immunohistochemically examined the expression of CYP26A1 in cervical squamous cell carcinoma (SCC) and its precursors, including low- and high-grade squamous intraepithelial lesions (LSIL and HSIL, respectively), as well as head and neck cancer (HNC). The association between CYP26A1 expression and a number of clinicopathological parameters was also evaluated.. CYP26A1 was not expressed in normal cervical epithelium. CYP26A1 expression was present in LSIL but limited to basal and parabasal cells. HSIL cases exhibited strong nuclear expression of CYP26A1 and mixed cytoplasmic expression patterns with widely distributed expression toward the epithelial surface. Importantly, strong cytoplasmic staining of CYP26A1 was observed in 19 of 50 (38%) patients with cervical SCC. Elevated expression of CYP26A1 was significantly associated with younger age (<50 years) and lymph node involvement (pN). Similarly, CYP26A1 was not expressed in non-neoplastic tissues of the head and neck, but strong cytoplasmic staining of CYP26A1 was observed in 52 of 128 (41%) HNC cases. Such strong CYP26A1 expression was significantly associated with the primary tumor stage of carcinomas (pT) and the pathological tumor-node-metastasis (pTNM) stage in HNC.. Our results indicated an elevated CYP26A1 expression in malignant and precancerous dysplastic lesions of the human cervix, which also increased with the progression of cervical squamous neoplasia. In addition, this report is the first to demonstrate the increased expression of CYP26A1 in HNC and its significant correlation with primary tumor growth. These data suggested that CYP26A1 overexpression might contribute to the development and progression of cervical malignancies and squamous neoplasia of the head and neck.

Topics: Carcinoma, Squamous Cell; Cytochrome P-450 Enzyme System; Disease Progression; Female; Head and Neck Neoplasms; Humans; Retinoic Acid 4-Hydroxylase; Tretinoin; Uterine Cervical Neoplasms

All-trans retinoic acid (ATRA) has been demonstrated to inhibit tumor growth by restoration of gap junctional intercellular communication (GJIC) via upregulation of connexin (Cx) expression in some solid tumors. However, the relationship between ATRA and GJIC remains unclear in oral squamous cell carcinoma (OSCC). The aim of this study was to investigate the effect of ATRA on the GJIC function of OSCC.. We measured the effects of ATRA on the viability and cell cycle distribution of SCC9 and Tca8113 OSCC cells. The GJIC function was observed using the scrape-loading dye transfer technique, and the mRNA and protein levels of Cx32 and Cx43 were detected by qRT-PCR, Western blot, and immunofluorescence assays.. ATRA inhibited the growth of OSCC cells in a dose- and time-dependent manner (P <0.05) and caused cell cycle arrest. ATRA-treated cells showed a 2.69-fold and 2.06-fold enhancement of GJIC in SCC9 and Tca8113 cells, respectively (P <0.05). Moreover, ATRA induced upregulation of Cx32 and Cx43 at both the mRNA and protein levels in OSCC cells.. Our results indicated that restoration of GJIC via enhanced Cx32 and Cx43 expression might serve as a novel mechanism for the anti-tumor effect of ATRA in OSCC.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Communication; Connexin 43; Connexins; Gap Junction beta-1 Protein; Gap Junctions; Gene Expression Regulation, Neoplastic; Humans; Mouth Neoplasms; RNA, Messenger; Tretinoin; Tumor Cells, Cultured; Up-Regulation

Aberrant histone acetylation plays an essential role in the neoplastic process via the epigenetic silencing of tumour suppressor genes (TSGs); therefore, the inhibition of histone deacetylases (HDAC) has become a promising target in cancer therapeutics. To investigate the correlation of histone acetylation with clinicopathological features and TSG expression, we examined the expression of acetylated H3 (AcH3), RARβ2, E-cadherin, and β-catenin by immunohistochemistry in 65 cervical squamous cell carcinoma patients. The results revealed that the absence of AcH3 was directly associated with poor histological differentiation and nodal metastasis as well as reduced/negative expression of RARβ2, E-cadherin, and β-catenin in clinical tumour samples. We further demonstrated that the clinically available HDAC inhibitors valproic acid (VPA) and suberoylanilide hydroxamic acid (SAHA), in combination with all-trans retinoic acid (ATRA), can overcome the epigenetic barriers to transcription of RARβ2 in human cervical cancer cells. Chromatin immunoprecipitation analysis showed that the combination treatment increased the enrichment of acetylated histone in the RARβ2-RARE promoter region. In view of these findings, we evaluated the antitumor effects induced by combined VPA and ATRA treatment in a xenograft model implanted with poorly differentiated human squamous cell carcinoma. Notably, VPA restored RARβ2 expression via epigenetic modulation. Additive antitumour effects were produced in tumour xenografts by combining VPA with ATRA treatment. Mechanistically, the combination treatment reactivated the expression of TSGs RARβ2, E-cadherin, P21 (CIP1) , and P53 and reduced the level of p-Stat3. Sequentially, upregulation of involucrin and loricrin, which indicate terminal differentiation, strongly contributed to tumour growth inhibition along with partial apoptosis. In conclusion, targeted therapy with HDAC inhibitors and RARβ2 agonists may represent a novel therapeutic approach for patients with cervical squamous cell carcinoma.

Topics: Animals; Antineoplastic Agents; beta Catenin; Cadherins; Carcinoma, Squamous Cell; Cell Line, Tumor; Disease Models, Animal; Epigenesis, Genetic; Female; Gene Expression Regulation, Neoplastic; Histone Deacetylase Inhibitors; Histone Deacetylases; Histones; Humans; Promoter Regions, Genetic; Protein Binding; Retinoid X Receptor beta; Transcriptional Activation; Tretinoin; Tumor Burden; Tumor Suppressor Proteins; Uterine Cervical Neoplasms; Valproic Acid; Xenograft Model Antitumor Assays

There are limited studies on the effects of drugs that modulate epigenetic regulation for head and neck squamous cell carcinoma (HNSCC). This study determined the effect of valproic acid (VPA) on HNSCC.. Growth inhibition effects of VPA alone or in combination with 5-aza-2'deoxycytidine (5-aza-dC) or all-trans retinoic acid (ATRA) was evaluated with MTT and clonogenic assays on 5 HNSCC cell lines. The mechanism of growth inhibition was investigated by looking at markers of terminal differentiation and senescence.. Growth inhibition profiles of HNSCC cell lines varied in response to VPA. Inhibition of clonogenic survival in response to VPA was associated with an upregulation of p21, expression of terminal differentiation markers, and cellular senescence. Notably, a combination treatment of 5-Aza-dC-VPA-ATRA enhanced growth inhibition in cells resistant to VPA.. VPA is a potent inhibitor of proliferation in some HNSCC cell lines, and may be used to treat HNSCC.

Topics: Antineoplastic Agents; Azacitidine; Carcinoma, Squamous Cell; Cell Culture Techniques; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cellular Senescence; Decitabine; Head and Neck Neoplasms; Histone Deacetylase Inhibitors; Humans; Squamous Cell Carcinoma of Head and Neck; Tretinoin; Valproic Acid

The effect of all-trans retinoic acid (ATRA) on cutaneous squamous cell carcinomas (c-SCC) has been poorly described. Because the imbalance of CRABP-II-mediated anticancer signalling and FABP5-mediated growth-promoting signalling was supposed to be related with ATRA sensitivities of cancer cells, COLO16 human c-SCC cell line was selected to check underlying mechanism leading to ATRA resistance by multiple experimental approaches. The results revealed that COLO 16 cells were resistant to 15 μm ATRA treatment. FABP5 as well as the elements related with CRABP-II signalling (CYP26A1, CYP26B1, CRABP-I, RARα/β/γ and RXRα/β/γ) and with FABP5 signalling (PPARβ/δ) were expressed, but CRABP-II was undetectable in COLO 16 cells. 5-Aza treatment enhanced CRABP-II expression but further bisulfite sequencing PCR-DNA sequencing revealed no methylation in CRABP-II promoter region. Transfection of CRABP-II-expressing plasmids or FABP5 siRNA or both successfully manipulated the level(s) of target gene expression but failed to overcome ATRA resistance in the transfectants. In conclusion, CRABP-II and FABP5 expression were imbalanced in ATRA-resistant COLO 16 cells. 5-Aza-enhanced CRABP-II expression and unmethylation in CRABP-II promoter region suggest the methylation of certain CRABP-II regulatory gene(s) in COLO 16 cells. As neither restoration of CRABP-II expression nor the increased CRABP-II versus FABP5 ratio can overcome ATRA resistance of COLO 16 cells, additional ATRA-resistant mechanism(s) may present in human c-SCCs and COLO 16 cells would be of value in addressing this issue.

Topics: Antineoplastic Agents; Azacitidine; Carcinoma, Squamous Cell; Cell Line, Tumor; Cytochrome P-450 Enzyme System; Decitabine; DNA Methylation; Drug Resistance, Neoplasm; Fatty Acid-Binding Proteins; Humans; PPAR delta; Receptors, Retinoic Acid; Retinoic Acid 4-Hydroxylase; Skin Neoplasms; Tretinoin

To evaluate disease dynamics, treatment results, and frequency of malignant transformation. Ten-year single center retrospective study. The study included 171 patients, 28-99 years old. Follow-up was 1-16 years. 49.5% exhibited changes in clinical presentation, with 19% yearly increase of probability for type shift. Index of extent (number of oral locations) showed a mean 40% decrease and 94.1% reported improvement. There were significant differences between treated and untreated patients (P=0.012). Patients with or without systemic diseases had identical treatment requirements for oral lesions. The prevalence of SCC was 5.8%. Oral lichen planus constantly changes presentation and extent of involvement. The effect of systemic diseases was insignificant in the present study. There is a clear value for treatment to reduce the extent of lesions. The results indicate that all clinical forms of the disease need to be equally followed since the clinical presentation typically changes over time, while malignant transformation can occur in all forms.

Topics: Adult; Aged; Aged, 80 and over; Anti-Inflammatory Agents; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Clobetasol; Dexamethasone; Female; Humans; Lichen Planus, Oral; Male; Middle Aged; Mouth Neoplasms; Precancerous Conditions; Prednisone; Prevalence; Retrospective Studies; Tacrolimus; Tretinoin; Triamcinolone

Given the high incidence of non-melanoma skin cancer (NMSC), a preventative intervention would be desirable. Except for regular sunscreen use, the quest for chemoprevention of NMSC in the general population has been unsuccessful. Weinstock et al. assessed the effects of 0.1% topical tretinoin on NMSC. Like earlier efforts at chemoprevention, this study failed to show therapeutic benefit. Future successful preventative strategies will likely rely on short-term, intermittent therapy or treatments used for other common indications.

Topics: Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Female; Humans; Keratinocytes; Male; Skin Neoplasms; Tretinoin

Differentiation therapy is a novel approach to eradicate cancer stem cells (CSCs), including head and neck squamous carcinoma CSC (HNSC CSC). All-trans-retinoic acid (ATRA) is a potent differentiating agent. We studied the anti-tumour effect of ATRA on HNSC CSC. HNSC CSCs were differentiated by ATRA in a serum-free conditioned medium. The effect of differentiation on tumour growth was assessed in vitro and in vivo, and chemosensitisation was examined using a colorimetric viability assay. In addition, the involvement of Wnt/β-catenin signalling as an underlying mechanism of the anti-tumour effect of retinoic acid (RA) on HNSC CSCs was assessed. ATRA suppressed the expression of the stem cell markers Oct4, Sox2, Nestin and CD44 in HNSC CSCs and inhibited the proliferation of HNSC CSCs in vitro and in vivo. Furthermore, ATRA treatment augmented the chemosensitising effects of cisplatin. The anti-tumour effects of ATRA may be associated with down-regulation of Wnt/β-catenin signalling. In conclusion, ATRA may be potentially valuable in treatment of HNSC CSC, especially in combination with cisplatin.

Topics: Animals; Antineoplastic Agents; beta Catenin; Carcinoma, Squamous Cell; Cell Proliferation; Cisplatin; Female; Head and Neck Neoplasms; Humans; Mice; Mice, Inbred BALB C; Neoplastic Stem Cells; Squamous Cell Carcinoma of Head and Neck; Tretinoin; Wnt Signaling Pathway

Topical retinoids, compounds that are metabolites, analogues, or derivatives of retinol and possess biological vitamin A activity, are among the most used adjunctive agents for the mitigation of fine wrinkles, mottled hyperpigmentation, and tactile roughness of photodamaged and chronically aged skin. Retinoic acid (RA) is the most active biological form of vitamin A and remains the medical treatment of choice for photoaged skin. Retinyl palmitate (RP) is the major storage form of vitamin A in the skin and, because RP is also the most stable of available vitamin A esters, it is readily incorporated into the oil phase of cosmetic creams or lotions. Therefore, the topical application of RP is a practical strategy for increasing the levels of vitamin A in the skin. Usual cosmetic product concentrations of RA range from 0.025% to 0.1% and those of RP range from 0.1% to 5%. With a maximum absorbance around 325 nm, RA and RP absorb both ultraviolet A and B radiation (UVA and UVB) in incident sunlight. A 1-year study was conducted in mice to determine whether RA and RP would alter the photocarcinogenicity of broad-UV spectrum light generated by xenon arc lamps, termed simulated solar light (SSL), or narrow spectrum UV light generated by UVA and UVB lamps.

Topics: Administration, Topical; Animals; Antineoplastic Agents; Carcinogenicity Tests; Carcinoma, Squamous Cell; Diterpenes; Dose-Response Relationship, Drug; Female; Male; Mice; Mice, Inbred Strains; Mice, Nude; Retinyl Esters; Skin; Skin Neoplasms; Sunlight; Tretinoin; Vitamin A

The potential application of retinoic acid receptor activators, such as all trans-retinoic acid (ATRA), for treating various cancers have been studied both pre-clinically and clinically. Whether ATRA has an anticancer effect on human esophageal squamous cancer cell (ESCC) is still unknown. We have explored the anticancer effect of ATRA in ESCC, and in this study, the effects of ATRA on levels and patterns of expression of the vascular endothelial growth factor (VEGF) signal transduction pathway in transplantable tumor growth of the human ESCC cell line, EC9706, in nude mice.. The animal model of the ESCC xenograft was made by subcutaneous implantation of tumor cells into nude mice. Reverse transcription-polymerase chain reaction (RT-PCR), Western blotting and immunohistochemical assays were used to detect the expression of the VEGF signal transduction pathway in ESCC xenograft tissues.. Compared to the control group, the tumor inhibition rates in the low dose ATRA, high dose ATRA, and 5-FU groups were 83.21%, 88.32%, 91.02%, respectively. The protein and mRNA levels of VEGF were down-regulated after being treated with ATRA and 5-FU compared to the control group (P < 0.05). The study also revealed that ATRA specifically down-regulated VEGF and the component of the VEGF signal transduction pathway of CD31, CD34, and CD105 (component of the TGF-β receptor) in ESCC xenograft tissues (P < 0.05).. ATRA can significantly inhibit tumor growth and has anticancer effects on transplantable tumor growth of human ESCC cell line EC9706 in nude mice. These findings indicate that ATRA specifically down regulated VEGF and the components of VEGF signal transduction, which may be an important mechanism responsible for the neoangiogenesis inhibition of ESCC cells.

Topics: Animals; Blotting, Western; Carcinoma, Squamous Cell; Cell Line, Tumor; Esophageal Neoplasms; Humans; Immunohistochemistry; Mice; Mice, Nude; Neovascularization, Pathologic; Real-Time Polymerase Chain Reaction; Tretinoin; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

Although oncogenic human papillomavirus (HPV) infections have been established as the necessary cause of cervical cancer, most HPV infections are transient and rarely progress to squamous cervical lesions. The activity of HPV is tightly associated with epithelial cell differentiation; therefore, regulators of differentiation, such as retinoic acid (RA), have been considered targets for the prevention of HPV-associated squamous intraepithelial lesion (SIL) development. The purpose of this study was to determine the association between circulating RA and early events in cervical carcinogenesis, specifically type-specific HPV clearance and SIL detection. Archived blood samples from 643 women participating in the Ludwig-McGill Cohort in São Paulo, Brazil, were analyzed by high-pressure liquid chromatography for three RA isomers (all-trans, 13-cis, and 9-cis-RA). A type-specific HPV clearance event was defined as two consecutive visits negative for an HPV type during follow-up for 364 HPV-positive women. Among the 643 women in this analysis, 78 were diagnosed with incident SIL. The probability of clearing an oncogenic HPV infection was not significantly different across RA isomer quartiles. There was a suggestion that increasing all-trans-RA increased the rate of nononcogenic HPV clearance (P-trend = 0.05). There was no association observed between serum RA levels and incident SIL. Our results suggest that elevated circulating RA isomer levels do not increase the rate of HPV clearance or reduce the risk of incident SIL. The role of RA in the inhibition of HPV-induced carcinogenesis, as shown in vitro, lacks confirmatory evidence within epidemiologic studies among women.

Topics: Adolescent; Adult; Alphapapillomavirus; Biological Transport; Brazil; Carcinoma, Squamous Cell; Cohort Studies; Female; Humans; Incidence; Middle Aged; Papillomavirus Infections; Risk Factors; Tretinoin; Uterine Cervical Dysplasia; Uterine Cervical Neoplasms; Viral Load; Young Adult

NF-kappaB is a survival signaling transcription factor complex involved in the malignant phenotype of many cancers, including squamous cell carcinomas (SCC). The citrus coumarin, auraptene (AUR), and the ethno-medicinal ginger (Alpinia galanga) phenylpropanoid, 1'-acetoxychavicol acetate (ACA), were previously shown to suppress 12-O-tetradecanoylphorbol-13-acetate (TPA) induced mouse skin tumor promotion. The goal of the present study was to determine whether AUR and ACA are effective either alone or in combination with all-trans retinoic acid (ATRA) for suppressing SCC tumor growth.. We first determined the effects of orally administered ACA (100 mg/kg bw) and AUR (200 mg/kg bw) on lipopolysaccharide (LPS)-induced NF-kappaB activation in NF-kappaB-RE-luc (Oslo) luciferase reporter mice. Dietary administration of AUR and ACA +/- ATRA was next evaluated in a xenograft mouse model. Female SCID/bg mice were fed diets containing the experimental compounds, injected with 1 x 106 SRB12-p9 cells s.c., palpated and weighed twice a week for 28 days following injection.. Both ACA and AUR suppressed LPS-induced NF-kappaB activation in the report mice. In the xenograft model, AUR (1000 ppm) and ACA (500 ppm) modestly suppressed tumor volume. However, in combination with ATRA at 5, 10, and 30 ppm, ACA 500 ppm significantly inhibited tumor volume by 56%, 62%, and 98%, respectively. The effect of ATRA alone was 37%, 33%, and 93% inhibition, respectively. AUR 1000 ppm and ATRA 10 ppm were not very effective when administered alone, but when combined, strongly suppressed tumor volume by 84%.. Citrus AUR may synergize the tumor suppressive effects of ATRA, while ACA may prolong the inhibitory effects of ATRA. Further studies will be necessary to determine whether these combinations may be useful in the control of human SCC.

Topics: Animals; Antineoplastic Agents; Benzyl Alcohols; Blotting, Western; Carcinoma, Squamous Cell; Citrus; Coumarins; Drug Synergism; Drug Therapy, Combination; Female; Humans; Lipopolysaccharides; Luciferases; Male; Mice; Mice, SCID; NF-kappa B; Plant Extracts; Skin Neoplasms; Tretinoin; Tumor Cells, Cultured; Xenograft Model Antitumor Assays; Zingiber officinale

Oral squamous cell carcinoma (OSCC) may arise from potentially malignant oral lesions. All-trans retinoic acid (atRA), which plays a role in cell growth and differentiation, has been studied as a possible chemotherapeutic agent in the prevention of this progression. While the mechanism by which atRA suppresses cell growth has not been completely elucidated, it is known that homeobox genes are atRA targets. To determine if these genes are involved in the atRA-mediated OSCC growth inhibition, PCR array was performed to evaluate the expression of 84 homeobox genes in atRA-sensitive SCC-25 cells compared to atRA-resistant SCC-9 cells following 7 days with atRA treatment. Results showed that the expression of 8 homeobox genes was downregulated and expression of 4 was upregulated in SCC-25 cells but not in SCC-9 cells. Gene expression levels were confirmed for seven of these genes by RT-qPCR. Expression of three genes that showed threefold downregulation was evaluated in SCC-25 cells treated with atRA for 3, 5, and 7 days. Three different patterns of atRA-dependent gene expression were observed. ALX1 showed downregulation only on day 7. DLX3 showed reduced expression on day 3 and further reduced on day 7. TLX1 showed downregulation only on days 5 and 7. Clearly the expression of homeobox genes is modulated by atRA in OSCC cell lines. However, the time course of this modulation suggests that these genes are not direct targets of atRA mediating OSCC growth suppression. Instead they appear to act as downstream effectors of atRA signaling.

Topics: Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Models, Biological; Mouth Neoplasms; Polymerase Chain Reaction; Tretinoin

Topics: Antineoplastic Agents; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Humans; Keratinocytes; Quality of Life; Randomized Controlled Trials as Topic; Skin Neoplasms; Tretinoin; United States; United States Department of Veterans Affairs

To investigate the impact of all-trans retinoic acid (ATRA) on chemosensitivity to esophageal squamous cell carcinoma EC9706 cells in vitro and its mechanism.. EC9706 cells were routinely cultured as the control group. The experimental group was divided into three groups. The ATRA group with ATRA in final concentration of 1 µmol/L; the 5-Fu group with 5-Fu in final concentration of 50 mg/L; the combined treatment group with ATRA in final concentration of 1 µmol/L and 5-Fu 50 mg/L. The cell apoptosis was detected by terminal deoxynucleotidy transferase mediated dUTP nick end labelling (TUNEL). The cell cycle and apoptosis were detected by flow cytometry.. The results of TUNEL showed that in the combined treatment group appeared a large number of apoptotic cells, and their nuclei were stained brown, with a positive rate of 89.7%. There was a significant difference in the comparison with the ATRA group (38.3%) and 5-Fu group (40.3%) (P < 0.05). The flow cytometry showed that the ATRA + 5-Fu group had a significantly higher apoptosis rate (76.9% ± 2.7%) than that in the ATRA group (38.2% ± 2.6%) and 5-Fu group (45.2% ± 2.3%) (P < 0.05). The ratio of cells in G(1) phase increased in the ATRA + 5-Fu group (83.4% ± 3.0%), significantly higher than (48.2% ± 2.5%) in the ATRA group and (53.2% ± 2.6%) in the 5-Fu group (P < 0.05). The ratio of cells in S + G(2)/M phase was decreased in the ATRA + 5-Fu group, with a significant difference (P < 0.05) when compared with other groups. There was no significant difference between the ATRA group and 5-Fu group (P > 0.05) in the apoptosis rate and the proportion of cells at different phases.. ATRA can induce apoptosis of esophageal carcinoma EC9706 cells in vitro. The combination of ATRA and 5-Fu may enhance the chemotherapeutic efficacy.

Topics: Antimetabolites, Antineoplastic; Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Cell Cycle; Cell Line, Tumor; Drug Synergism; Esophageal Neoplasms; Fluorouracil; Humans; Tretinoin

To examine the expression of cytokeratin-13 (CK-13) in oral squamous cell carcinoma (OSCC) and to discuss the effects of all-trans retinoic acid (ATRA) or arsenic trioxide (As2 O3) on the differentiation of human oral undifferentiated squamous cell carcinoma cell line KB cells.. The cultured KB cells were divided into three groups, ATRA group, As2 O3 group, and control. The expression of CK-13 in KB cells was detected using the immunofluorescence before and after KB cells were induced by ATRA or As2 O3.. The expression rates of CK-13 in KB cells in the ATRA group and As2 O3 group were significantly higher than that in the control (P < 0.05), but there was no significant difference in the expression between ATRA and As2 O3 group(P > 0.05).. ATRA and As2 O3 both have the ability to differentiate the KB cells, and the expression is associated with the degree of tumor differentiation. CK-13 may serve as a molecular marker to evaluate the effect of the differentiation treatment on OSCC.

Topics: Arsenic Trioxide; Arsenicals; Carcinoma, Squamous Cell; Cell Differentiation; Fluorescent Antibody Technique; Humans; KB Cells; Keratin-13; Mouth Neoplasms; Oxides; Tretinoin

Squamous cell carcinoma (SCC) of the skin is the most clinically aggressive form of nonmelanoma skin cancer. We have determined the effects of all-trans retinoic acid (ATRA), a naturally occurring chemopreventive retinoid, on signal transducer and activator of transcription 3 (Stat3) signaling during the development of skin SCC. Stat3 is a transcription factor that plays a critical role in cell proliferation and survival, and it is constitutively active in several malignant cell types. We have previously shown that Stat3 is required for the initiation, promotion, and progression of skin SCC. ATRA is a highly efficient suppressor of tumor formation in the two-stage mouse skin carcinogenesis model and we have shown that this effect correlates with the suppression of the B-Raf/Mek/Erk signaling pathway. In this study, we have determined the pattern of Stat3 phosphorylation throughout the course of the two-stage protocol, both in the presence and absence of ATRA. We have used both SENCAR mice and K5.Stat3C transgenic mice, which express the Stat3C protein, a constitutively active form of Stat3, in the skin. Using Western blotting and immunohistochemical staining with phosphospecific antibodies, we show that coadministration of ATRA suppressed the 12-O-tetradecanoylphorbol-13-acetate-induced phosphorylation of Stat3 in both models, but was only able to suppress tumor formation in the SENCAR mice. Surprisingly, ATRA actually enhanced tumor formation in 12-O-tetradecanoylphorbol-13-acetate-treated K5.Stat3C mice. We hypothesize that ATRA blocks tumor formation, at least in part, by targeting events upstream of Stat3, such as the B-Raf/Mek/Erk pathway, and that in the K5.Stat3C mice, in which Stat3 activity is constitutive, it cannot suppress tumor formation.

Topics: Animals; Antineoplastic Agents; Blotting, Western; Carcinogens; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Extracellular Signal-Regulated MAP Kinases; Female; Immunohistochemistry; MAP Kinase Kinase Kinases; Mice; Mice, Inbred SENCAR; Mice, Transgenic; raf Kinases; Signal Transduction; Skin Neoplasms; STAT3 Transcription Factor; Tetradecanoylphorbol Acetate; Tretinoin

The transcriptional silencing of some cell cycle inhibitors and tumor suppressors, such as p16 and retinoic acid receptor beta(2), by DNA hypermethylation at CpG islands is commonly found in human oral squamous carcinoma cells. We examined the effects of the DNA methyltransferase inhibitor 5-Aza-2'-deoxycytidine (5-Aza; 0.25 mg/kg body weight), all-trans retinoic acid (RA; given at 100 microg/kg body weight and 1 mg/kg body weight), and the combination of 5-Aza and the low-dose RA on murine oral cavity carcinogenesis induced by the carcinogen 4-nitroquinoline 1-oxide (4-NQO) in a mouse model. All the drug treatments were done for 15 weeks after a 10-week 4-NQO treatment. Mice in all drug treatment groups showed decreases in the average numbers of neoplastic tongue lesions. The combination of 5-Aza and RA effectively attenuated tongue lesion severity. Although all drug treatments limited the increase in the percentage of proliferating cell nuclear antigen-positive cells and the decrease in the percentage of p16-positive cells caused by the 4-NQO treatment in mouse tongue epithelial regions without visible lesions and in the neoplastic tongue lesions, the combination of 5-Aza and RA was the most effective. Collectively, our results show that the combination of a DNA demethylating drug and RA has potential as a strategy to reduce oral cavity cancer in this 4-NQO model.

Topics: 4-Nitroquinoline-1-oxide; Animals; Antineoplastic Combined Chemotherapy Protocols; Azacitidine; Carcinogens; Carcinoma, Squamous Cell; Cyclin-Dependent Kinase Inhibitor p16; Cyclooxygenase 2; Decitabine; DNA Modification Methylases; Female; Immunoenzyme Techniques; Mice; Mice, Inbred C57BL; Mouth Mucosa; Mouth Neoplasms; Proliferating Cell Nuclear Antigen; Proto-Oncogene Proteins c-myb; Receptors, Retinoic Acid; Retinoids; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tretinoin

Antisense oligonucleotides against hTR (As-ODN-hTR) have shown promising results as treatment strategies for various human malignancies. All-trans retinoic acid (ATRA) is a signalling molecule with important roles in differentiation and apoptosis. Biological responses to ATRA are currently used therapeutically in various human cancers. The aim of this study was to evaluate the anti-tumor effects of As-ODN-hTR combined with ATRA in vivo.. In situ human oral squamous cell carcinoma (OSCC) models were established by subcutaneous injection of Tca8113 cells. Mice were treated with sense oligonucleotides against hTR(S-ODN-hTR) alone, As-ODN-hTR alone, ATRA alone, As-ODN-hTR plus ATRA, or S-ODN-hTR plus ATRA. Tumor size and weight were assessed in the mice. Telomerase activity was detected by a TRAP assay, apoptotic cells were evaluated with a Tunel assay, the expression of apoptosis-related proteins (Bcl-2 and Bax) was evaluated by immunohistochemistry and ultrastructural morphological changes in the tumor specimen were examined.. Both As-ODN-hTR and ATRA can significantly inhibit tumor growth in this OSCC xenograft solid-tumor model, and the combination of the two agents had a synergistic anti-tumorogenic effect. We also demonstrated that this anti-tumor effect correlated with inhibition of telomerase activity. Furthermore, significant increases in the number of apoptotic cells, typical apoptotic morphology and a downregulation of the anti-apoptotic protein, bcl-2 were observed in the treated tissues.. The combination of As-ODN-hTR and ATRA has a synergistic anti-tumor effect. This anti-tumor effect can be mainly attributed to apoptosis induced by a decrease in telomerase activity. Bcl-2 plays an important role in this process. Therefore, combining As-ODN-hTR and ATRA may be an approach for the treatment of human oral squamous cell carcinoma.

Topics: Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Line, Tumor; Drug Synergism; Female; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Mouth Neoplasms; Oligonucleotides, Antisense; Tretinoin; Xenograft Model Antitumor Assays

All-trans retinoic acid (ATRA) and sodium butyrate (SB) have shown growth-inhibitory and differentiation-inducing properties to tumor cells when used as single agents or in combination, but the exact molecular mechanism still remains to be determined. In order to determine the mechanism of the synergy in treatment with RA and SB, we evaluated the growth inhibition capability of ATRA and SB, alone or in combination, in human oral squamous carcinoma cell lines SCC-1 and SCC-9, and identified the expression of cell cycle-related genes. ATRA and SB inhibited cell growth and induced cell cycle G1 arrest. The inhibition effect was more pronounced with SB than with ATRA (p = 0.000). There were interactions between ATRA and SB (p = 0.000). Consistent with the inhibition effect and G1 arrest, ATRA and SB, alone or in combination, induced the expression of G1 phase markers cyclin-dependent kinase (CDK) 6, p21, and p27; inhibited the expression of S-G2 phase proteins CDK2; and decreased Rb phosphorylation. Cyclin D1 expression was increased in the SB- and ATRA + SB-treated groups, but inhibited in the ATRA-treated group. Cyclin B1 and cyclin E expression was slightly decreased in the SB- and ATRA + SB-treated groups, but did not change in the ATRA-treated group. These results indicate that the growth inhibition and G1 arrest of oral squamous carcinoma cells in response to ATRA and/or SB correlates with the induction of G1 phase cell cycle regulatory proteins CDK6, p21, and p27 and the inhibition of S-G2 phase cell cycle regulatory protein CDK2.

Topics: Butyrates; Carcinoma, Squamous Cell; Cell Cycle; Cell Proliferation; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase 6; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Humans; Intracellular Signaling Peptides and Proteins; Mouth Neoplasms; Tretinoin

Retinoic acid (RA) signalling is essential for epidermal differentiation; however, the mechanisms by which it acts are largely unexplored. Partitioning of RA between different nuclear receptors is regulated by RA-binding proteins. We show that cellular RA-binding proteins CRABP1 and CRABP2 and the fatty acid-binding protein FABP5 are dynamically expressed during skin development and in adult tissue. CRABP1 is expressed in embryonic dermis and in the stroma of skin tumours, but confined to the hair follicle dermal papilla in normal postnatal skin. CRABP2 and FABP5 are expressed in the differentiating cells of sebaceous gland, interfollicular epidermis and hair follicles, with FABP5 being a prominent marker of sebaceous glands and anagen follicle bulbs. All three proteins are upregulated in response to RA treatment or Notch activation and are negatively regulated by Wnt/beta-catenin signalling. Ectopic follicles induced by beta-catenin arise from areas of the sebaceous gland that have lost CRABP2 and FABP5; conversely, inhibition of hair follicle formation by N-terminally truncated Lef1 results in upregulation of CRABP2 and FABP5. Our findings demonstrate that there is dynamic regulation of RA signalling in different regions of the skin and provide evidence for interactions between the RA, beta-catenin and Notch pathways.

Topics: Animals; beta Catenin; Carcinoma, Squamous Cell; Cell Differentiation; Epidermis; Fatty Acid-Binding Proteins; Hair Follicle; Lymphoid Enhancer-Binding Factor 1; Mice; Mice, Transgenic; Neoplasm Proteins; Papilloma; Receptor, Notch1; Receptors, Retinoic Acid; Signal Transduction; Skin; Skin Neoplasms; Stromal Cells; Tretinoin; Up-Regulation

Topics: Carcinoma, Squamous Cell; Carcinoma, Transitional Cell; Drug Therapy, Combination; Humans; Ketoconazole; Neoplasm Recurrence, Local; Tretinoin; Urinary Bladder Neoplasms

To investigate the effect of a novel retinoid CD437 and all-trans retinoic acid (ATRA) in inducing cell apoptosis and inhibiting the proliferation of human epidermoid carcinoma A431 cells and normal human epidermal keratinocytes.. MTT assay was used to determine the inhibitory effects of CD437 and ATRA on the growth of A431 cells and normal human epidermal keratinocytes, and the cell morphological changes were observed microscopically. Flow cytometry was used to investigate the effect of CD437 and ATRA on the cell cycle and apoptosis.. CD437 was more effective than ATRA in inhibiting the proliferation of A431 cells and normal human epidermal keratinocytes. CD437 increased the percentage of sub-G1 populations in A431 cells and induced G1 arrest in normal human epidermal keratinocytes. ATRA appeared to be relatively ineffective for inducing apoptosis in A431 cells as compared to CD437. CD437 did not duce obvious apoptosis in normal human epidermal keratinocytes.. CD437 is more effective than ATRA in inhibiting the proliferation and inducing apoptosis in A431 cells and shows selective apoptosis-inducing effect against malignant keratinocytes, suggesting its potential in the prevention or treatment of cutaneous carcinoma.

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Cell Cycle; Cell Line, Tumor; Cells, Cultured; Epidermis; Flow Cytometry; Humans; Keratinocytes; Male; Retinoids; Tretinoin; Young Adult

In this study, the effects of all-trans retinoic acid (ATRA) on human oral cancer cells with regard to cell growth, the cell cycle, and alkaline phosphatase (ALP) activity were evaluated. Human oral cancer KB cells were treated with various concentrations of ATRA, and cell growth was then determined using the MTT viability assay. The cell-cycle distribution and ALP activity were analysed using a flow cytometer and chemical analyser, respectively. The KB cells were inhibited by ATRA at concentrations of 1-16 microM (1 microM, P<0.05; 2 microM, P<0.01; 4, 8 and 16 microM, P<0.001) in a dose-dependent manner. ATRA arrested KB cells in the G0/G1 phase. The ALP activity in KB cells was increased by ATRA. This is one of the first studies to focus on the expression of ALP in human head-and-neck carcinoma cells treated with retinoids. These findings suggest that the anti-tumour effects of ATRA on human oral cancer are associated with G0/G1 phase arrest and an increase in ALP activity.

Topics: Alkaline Phosphatase; Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Dose-Response Relationship, Drug; Flow Cytometry; G1 Phase; Humans; KB Cells; Mouth Neoplasms; Resting Phase, Cell Cycle; Tretinoin; Up-Regulation

Epidemiological studies have shown an inverse relationship between dietary vitamin A intake and the risk of developing lung cancer. The aim of this study was to investigate the vitamin A status in patients with lung cancer, by determining the serum levels of retinoic acid, retinol and retinyl palmitate.. In total, 36 patients with lung cancer and 27 controls were assessed. Of the patients 14 had squamous cell carcinoma, 3 adenocarcinoma, 15 non-small cell lung cancer and 4 small cell lung cancer. Serum retinoic acid, retinol and retinyl palmitate levels were determined with HPLC and UV detection, after liquid extraction.. Serum retinol levels did not differ between patients (733.5 +/- 326.4 ng/mL) and controls (734.5 +/- 337.1 ng/mL). The retinyl palmitate concentration tended to be lower in patients (14.3 +/- 9.7 ng/mL) than in controls (16.7 +/- 13.7 ng/mL). The serum retinoic acid levels were significantly lower in patients (1.9 +/- 0.6 ng/mL) than in controls (2.5 +/- 1.1 ng/mL, P < 0.05). A positive correlation was observed between the retinol and retinoic acid levels and retinyl palmitate and retinoic acid levels.. The lower levels of retinoic acid in patients with lung cancer suggest there may be a deficiency or impairment in retinol metabolism in these patients. Further studies with larger numbers of patients are needed to evaluate the possible relationship between serum retinoid levels and lung cancer.

Topics: Adenocarcinoma; Aged; Biomarkers, Tumor; Carcinoma, Non-Small-Cell Lung; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Chromatography, High Pressure Liquid; Disease Progression; Diterpenes; Female; Humans; Lung Neoplasms; Male; Prognosis; Retinyl Esters; Risk Factors; Tretinoin; Vitamin A

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Cell Cycle; Cell Line, Tumor; Head and Neck Neoplasms; Humans; Neoplasm Proteins; Retinoids; Tretinoin

Retinoids are known to suppress carcinogenesis in various epithelial tissues. Among them, all-trans-retinoic acid (atRA) is recognized as one such active retinoid. However, despite the known anticarcinogenic activity of atRA, it exhibits its short plasma half-life during repeated oral administration due to the "acute retinoid resistance" in the liver. This has been the major limitation in clinical applications of atRA. Therefore, in order to render atRA more suitable for clinical uses, sustained delivery of atRA using biodegradable microspheres is suggested in this study. When 50 mg atRA/kg of atRA-loaded microspheres were subcutaneously administered to rats once, the atRA concentration in plasma was maintained around 6.5 ng/ml for 7 weeks, with only minor signs of toxicity. When the chemopreventive efficacy of atRA-loaded microspheres was evaluated using a model of 4-nitroquinoline 1-oxide-induced oral carcinogenesis in F344 rats, a single injection of atRA-loaded microspheres significantly suppressed oral carcinogenesis. Additional injections of atRA-loaded microspheres, however, did not indicate further suppression of carcinogenesis.

Topics: 4-Nitroquinoline-1-oxide; Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Delayed-Action Preparations; Drug Carriers; Drug Compounding; Male; Microspheres; Mouth Neoplasms; Neoplasms, Experimental; Palatal Neoplasms; Polyesters; Polyethylene Glycols; Precancerous Conditions; Rats; Rats, Inbred F344; Solubility; Tongue Neoplasms; Tretinoin

We investigated the relationship between cell growth and differentiation and COX-2 expression in oral squamous cell carcinoma (SCC) in vitro and in vivo. Treatment of SCC25 oral squamous carcinoma cells with sodium butyrate (SB) at 0.5-5 mM or all-trans retinoic acid (ATRA) at 3-300 microM inhibited cell growth and induced apoptosis in a dose-dependent manner with concomittant increases in expression of keratin 13, p21WAF1/Cip1 and p27Kip1 and decreases in expression of COX-2. These effects were more pronounced with SB than with ATRA. Injection of SB or ATRA near SCC25-derived tumors in nude mice resulted in inhibition of growth and elevation of differentiation of the tumor accompanied by marked keratinization and increased expression of keratin 13 and decreased expression of COX-2. These results show that the differentiation-inducing agents, particularly SB, suppress growth of oral squamous carcinoma cells through apoptosis and induce cell differentiation possibly through mechanisms involving COX-2, p27Kip1 and/or p21WAF1/Cip1 in vitro and in vivo.

Topics: Animals; Apoptosis; Blotting, Western; Butyrates; Carcinoma, Squamous Cell; Cell Cycle Proteins; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Cyclooxygenase 2; DNA Primers; Female; Gene Expression Regulation, Neoplastic; Head and Neck Neoplasms; Humans; Immunohistochemistry; Isobutyrates; Keratins; Membrane Proteins; Mice; Mice, Inbred BALB C; Mice, Nude; Mouth Neoplasms; Prostaglandin-Endoperoxide Synthases; Reverse Transcriptase Polymerase Chain Reaction; RNA; Time Factors; Tretinoin; Tumor Suppressor Proteins

Systemic retinoic acid (RA) treatment for chemoprevention of squamous cell carcinoma of the head and neck (HNSCC) is limited by RA's toxic side effects at therapeutic doses. The pulsed-dye laser (PDL), through a mechanism of selective vascular targeting, may allow reduction of the RA dose to one that is better tolerated when these treatments are used in combination. This study tests our hypothesis that combination therapy of PDL irradiation and low-dose systemic RA is as effective as high-dose RA therapy alone in the chemoprevention of HNSCC.. Randomized, prospective study in a hamster model.. Dysplastic lesions were induced in the cheek pouches of 48 hamsters by painting with topical 9,10-dimethl-1,2-benzanthrancene (DMBA). The hamsters were randomly divided into four treatment groups: 1) control (no treatment); 2) PDL irradiation only; 3) 5.0 mg RA (all-trans retinoid, 5.0 mg/kg per day, intraperitoneally [IP]); and (4) PDL + 0.5 mg RA (0.5 mg/kg per day, IP). The PDL irradiation was conducted at day 0 and 15, whereas the RA treatment was continued for 27 days. Tumor burden was measured over time.. The lesions in all of three treatment groups grow more slowly than the untreated controls. The combination treatment of PDL and RA had the greatest inhibitory effect on tumors.. This study suggests that combination treatment of PDL and low-dose RA is more effective than high-dose RA alone in the chemoprevention of HNSCC in a hamster cheek-pouch model, so that it should allow greatly improved tolerance of this regimen.

Topics: Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Cheek; Cricetinae; Disease Models, Animal; Laser Therapy; Male; Mesocricetus; Mouth Mucosa; Mouth Neoplasms; Prospective Studies; Random Allocation; Tretinoin

Activation of telomerase is crucial for the continued growth and progression of cancer cells. In a previous study, we showed that telomerase is frequently activated in skin tumours.. Because retinoic acid (RA) plays an important role in the growth and differentiation of keratinocytes and as RA has some preventive and therapeutic effects on human skin cancers, we examined the effect of RA on the telomerase activity of HSC-1 human cutaneous squamous cell carcinoma cells.. Treatment of HSC-1 cells with all-trans RA (ATRA) significantly suppressed their telomerase activity. The suppression of telomerase activity was obvious at day 4 and was maximal at day 5 after the start of treatment with RA. This suppression was reversible as removal of ATRA allowed the recovery of telomerase activity. The suppression of telomerase activity correlated with the decreased expression of mRNA of human telomerase catalytic subunit (hTERT), the rate-limiting determinant of enzyme activity. The production of c-myc and of Sp1 proteins, transcription factors regulating hTERT expression, was not suppressed in HSC-1 cells by ATRA, but phosphorylation of extracellular signal-regulated kinases (ERK)1/2 and of the serine/threonine kinase Akt was significantly suppressed. Phosphorylation of the epidermal growth factor receptor, which regulates hTERT expression in HSC-1 cells, was not altered by ATRA.. These data indicate that RA is effective in inhibiting telomerase activity in HSC-1 cells. Suppression of ERK1/2 and Akt activation is presumed to be involved in the RA-induced suppression of hTERT.

Topics: Carcinoma, Squamous Cell; Cell Division; DNA-Binding Proteins; Enzyme Inhibitors; Extracellular Signal-Regulated MAP Kinases; Gene Expression Regulation, Enzymologic; Humans; Neoplasm Proteins; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Skin Neoplasms; Telomerase; Tretinoin; Tumor Cells, Cultured

All-trans retinoic acid (atRA) is one of the most potential chemopreventive agents for head and neck squamous cell carcinoma (HNSCC). However, the induced metabolism of atRA by cytochrome P450s in the liver limits its clinical applications. To overcome such limitation, we had developed atRA-loaded microspheres designed to release atRA for a long period. Unfortunately, the atRA-loaded microspheres severely induced inflammatory responses: that is, atRA released from the microspheres significantly induced the proliferation of fibroblasts and collagen deposition, thereby causing a permeability barrier for drugs from entering the blood stream. In the present study, the effects of celecoxib as an anti-inflammatory drug are investigated when it is concurrently used with atRA-loaded microspheres to treat 4-NQO-induced oral carcinogenesis. We investigated if it might influence the plasma concentration of atRA and its metabolism by preventing the fibroblast proliferation and collagen deposition, reduce the toxicity level of atRA, and improve the chemopreventive efficacy of atRA-loaded microspheres. The concurrently administered celecoxib prevented inflammatory responses and suppressed the number of fibroblasts and collagen deposition in the fibrous capsules for 14 days. The atRA concentration in plasma was also increased and the metabolism of atRA was significantly decreased within 2 weeks. In the 4-NQO-induced oral carcinogenesis study, the incidence of invasive SCC was above 44% when F344 rats were treated with atRA-loaded microspheres. However, the treatment using atRA-loaded microspheres and celecoxib concurrently could reduce the incidence of invasive SCC up to 28%, and three of 25 rats were found to have no tongue lesions. In conclusion, the concurrent use of celecoxib could maintain the atRA concentration in plasma at a higher level while reducing its metabolism by preventing inflammatory responses, thereby improving their chemopreventive effects against 4-NQO-induced oral carcinogenesis.

Topics: 4-Nitroquinoline-1-oxide; Animals; Anticarcinogenic Agents; Carcinoma, Squamous Cell; Celecoxib; Cyclooxygenase Inhibitors; Delayed-Action Preparations; Drug Therapy, Combination; Female; Liposomes; Male; Pyrazoles; Quinolones; Rats; Rats, Inbred F344; Rats, Sprague-Dawley; Sulfonamides; Tongue Neoplasms; Tretinoin

The chemotherapeutic effects of all-trans-retinoic acid (atRA) are mediated by the retinoic acid receptor beta (RARbeta), but RARbeta expression is reduced in a number of head and neck carcinoma (HNSCC) cells which causes resistance to RA treatment in half the patients with HNSCC. The possible mechanism for the reduced RARbeta expression has been suggested as the methylation of the CpG islands adjacent to the RA response elements (RARE) in the RARbeta promoter and the loss of histone acetylation. The suppressed RARbeta expression can be reactivated by a demethylating agent (5-aza-2'-deoxycytidine, 5-AzaC) or a histone deacetylase inhibitor (trichostatin A, TSA). Therefore, we sought to determine if the restoration of RARbeta activity, or a combination of these drugs, could restore the sensitivity to RA in RARbeta-negative HNSCC cells with an epigenetically methylated RARbeta promoter region. SqCC/Y1 cells resistant to atRA showed methylated and unmethylated forms in the RARbeta promoter region. RARbeta expression of these cells was restored by 5-AzaC or TSA treatment. Also, treatment with TSA and atRA combined synergistically increased the growth-inhibitory effect and highly induced the transcriptional activation of the RARbeta promoter compared to atRA treatment in HNSCC cells. Additionally, TSA alone and the combination 5-AzaC and TSA increased lysine-9 (Lys-9) acetylation and Lys-4 methylation of the first exon at the RARbeta gene, while decreasing the methylation of Lys-9 in the HNSCC cells.

Topics: Acetylation; Antineoplastic Agents; Azacitidine; Carcinoma, Squamous Cell; Cell Line, Tumor; Decitabine; DNA Methylation; Enzyme Inhibitors; Gene Expression Regulation, Neoplastic; Head and Neck Neoplasms; Histone Deacetylase Inhibitors; Histones; Humans; Hydroxamic Acids; Lysine; Promoter Regions, Genetic; Receptors, Retinoic Acid; Tretinoin

Human telomerase, activated in about 90% of cancers, is mainly composed of hTR, hTERT and TP1. The exposed RNA template of hTR is an ideal target for antisense oligonucleotides (As-ODN); while recent findings indicate all-trans retinoid acid (ATRA) could effectively inhibit the expression of catalytic subunit-hTERT. The aim of this study was to investigate the effect of ATRA and As-ODN in oral squamous cell carcinoma and whether telomerase activity could be synergistically inhibited by them and thus therapeutically exploited in the future. As-ODN-hTR was transfected into human tongue squamous cell carcinoma cell line (Tca8113) with or without ATRA. Telomerase activity was examined by PCR-Elisa; viability was compared with growth curve; apoptotic rate was analyzed by Annexin V/PI double staining and hTERT expression was tested with western blot. Tca8113 cells displayed significant growth inhibition during the 9-day exposure to ATRA/As-ODN, especially to a combination of As-ODN-hTR and 5muM ATRA, correlating with the inhibition of telomerase expression. The relative telomerase activity was inhibited during treated with As-ODN-hTR alone, ATRA alone, or a combination of them. While without ATRA, the effect of As-ODN would disappear at 96h after transfection. As-ODN-hTR alone or combined with ATRA also significantly increase the apoptotic rate. Our findings provided direct evidence, in oral squamous cell carcinoma, As-ODN-hTR and ATRA could synergistically inhibit telomerase activity and telomerase protein in human tongue squamous cell carcinoma cells, which correlated with the induction of growth arrest.

Topics: Carcinoma, Squamous Cell; Cell Line, Tumor; DNA-Binding Proteins; Down-Regulation; Genetic Therapy; Humans; Oligonucleotides, Antisense; Telomerase; Tongue Neoplasms; Transfection; Tretinoin

Angiogenesis and tumor-associated immunosuppression are two of the hallmarks of carcinogenesis. In previous studies we demonstrated in vitro that HNSCC tumor cells attract monocytes via monocyte chemotactic protein-1 (MCP-1) and activate them via transforming growth factor-beta 1(TGF-beta1) to secrete interleukin (IL)-1alpha, which in turn stimulates tumor cells to secrete increased levels of the angiogenic and immunosuppressive vascular endothelial growth factor (VEGF). These findings suggest that interaction between the immune system and VEGF-mediated angiogenesis is important for progression of HNSCC. Recent studies in vitro show that retinoic acid (RA) downregulates the release of MCP-1 and TGF-beta1 by tumor cells. Therefore, we investigated the ability of RA to modulate the ability of tumor cells to recruit and activate monocytes for participation in VEGF-mediated angiogenesis and immunosuppression in vivo.. Mice (ten/group) were injected daily with RA (160 microg/kg) for 3 weeks. After that time mice were sacrificed, and paraffin sections of tumors were obtained and stained for VEGF-A, CD68, and PECAM (CD31) by immunohistochemistry. The lungs, liver, and myocardium were analyzed for macro- and micrometastases. The plasma protein levels of VEGF-A and MCP-1 were determined by ELISA.. In RA-treated mice tumors regressed completely and RA prevented metastases (p=0.00) and macrophage infiltration (p=0.007). Treated mice downregulated VEGF-A (0 pg/ml) and MCP-1 (12 pg/ml) in peripheral blood (p=0.001).. Our findings suggest a new therapeutic possibility: the development of treatment protocols that can block each of the ways in which tumors induce new blood vessel growth and immunosuppression of the host.

Topics: Angiogenesis Inhibitors; Animals; Carcinoma, Squamous Cell; Cell Line, Tumor; Chemokine CCL2; Disease Progression; Down-Regulation; Humans; Immune Tolerance; Interleukin-1; Macrophage Activation; Male; Mice; Mice, Inbred A; Mouth Neoplasms; Neoplasm Metastasis; Neoplasm Transplantation; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tretinoin; Vascular Endothelial Growth Factor A

To investigate the receptor-related mechanism of retinoids inhibiting proliferation and inducing apoptosis of human oral squamous cell carcinoma cell line Tca8113.. The effects of 3 retinoids (namely 9-cis-RA, at-RA and 13-cis-RA), TTNPB (RAR agonist) and methoprene acid (Ma, RXR agonist) on proliferation and cell cycle of Tca8113 cells were analyzed by MTT assay and flow cytometry. The roles of these agents in inducing apoptosis of Tca8113 cells were also evaluated by detecting the expression of Bcl-2/Bax, TUNEL and active caspase-3 analysis.. Both retinoids and TTNPB could inhibit the proliferation of Tca8113 cells, and the effect of TTNPB was the most powerful in all the reagents, but MA had no such effect. At the concentration of 1 x 10(-5) mol/L, all the agents except for Ma could increase the percentage of G(1)/G(0)-stage cells after incubation of the cells for 24 h and 48 h. Retinoids and TTNPB could up-regulate the expression of Bax and down-regulate Bcl-2 expression. The results of TUNEL demonstrated that retinoids and TTNPB, but not Ma, could induce apoptosis of Tca8113 cells as compared with the control group (P<0.05). Except for Ma, all the agents up-regulated caspase-3 expression, and the effect of TTNPB was the strongest (P<0.05).. Retinoids can suppress the proliferation of and induce apoptosis of Tca8113 cells, the effect of which involves activation of RAR but not RXR. caspase-3 pathway is involved in apoptosis-inducing effects of retinoids.

Topics: Antineoplastic Agents; Apoptosis; Benzoates; Carcinoma, Squamous Cell; Cell Line, Tumor; Humans; Receptors, Retinoic Acid; Retinoids; Tongue Neoplasms; Tretinoin

To investigate the effects of ATRA, acitretin and tazarotene on the growth and apoptosis of human tongue squamous cell carcinoma cell line Tca8113. The effect of retinoids on growth of Tca8113 cells in vitro was examined by MTT assay and Trypan blue exclusion assay. Cell cycle analysis, early apoptosis analysis with double staining with Annexin V-FITC and PI, and active caspase-3 analysis with the staining of FITC-conjugated monoclonal rabbit anti-active caspase-3 antibody were made by flow cytometer. Streptavidin-biotin complex (SABC) immunocytochemical assays were employed for the detections of Bax/Bcl-2 proteins expressions. Our results showed that the retinoids inhibited growth of Tca8113 cells in a dose- and time-dependent manner with maximal inhibition 24 h after treatment of 10(-5) mol/L. 10(-5) mol/L retinoids altered cell cycle distribution of Tca8113 cells, revealing an increase in G0/G1-phase population, a decrease in S-phase population and the inhibition of G1/S switching. 10(-5) mol/L retinoids significantly induced apoptosis of Tca8113 cells (all P < 0.05), elevated the cells population with detectable active caspase-3 (P < 0.05 for all), increased the number of cells forming Bax and decreased the number of cells forming Bcl-2 significantly (all P < 0.05). Acitretin played a most prominent role among the retinoids. It is concluded that the inhibition of cell cycle progress of Tca8113 cells by ATRA, acitretin and tazarotene is one of the possible mechanisms for proliferation arrest of Tca8113 cells elicited by the retinoids. The retinoids mediate apoptosis in Tca8113 cells that may be caspase-dependent through mitochondria pathway. High concentration retinoids inhibit growth of Tca8113 cells in vitro by interfering with proliferation and inducing apoptosis of cells. Acitretin may be an alternative medicine for the prevention and treatment of tongue squamous cell carcinoma.

Topics: Acitretin; Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Humans; Nicotinic Acids; Tongue Neoplasms; Tretinoin

We described recently the growth inhibitory effects of the novel compound acyclic retinoid (ACR) in human hepatoma cell lines (M. Suzui et al., Cancer Res., 62: 3997-4006, 2002). In this study we examined the cellular and molecular effects of ACR on human squamous cell carcinoma (SCC) cells. ACR inhibited growth of the esophageal SCC cell line HCE7, and the head and neck SCC cell lines YCU-N861 and YCU-H891, with IC(50) values of approximately 10, 25, and 40 microM, respectively. Detailed studies were then done with HCE7 cells. Treatment of these cells with 10 microM ACR caused an increase of cells in G(0)-G(1) and induced apoptosis. This was associated with two phases of molecular events. During phase 1, which occurred within 6-12 h, there was an increase in the retinoic acid receptor beta (RARbeta) and p21(CIP1) proteins, and their corresponding mRNAs, and a decrease in the hyperphosphorylated form of the retinoblastoma protein. During phase 2, which occurred at approximately 24 h, there was a decrease in the cellular level of transforming growth factor alpha, and the phosphorylated (i.e., activated) forms of the epidermal growth factor receptor, Stat3, and extracellular signal-regulated kinase proteins, and a decrease in both cyclin D1 protein and mRNA. Reporter assays indicated that ACR inhibited the transcriptional activity of the cyclin D1, c-fos, and activator protein promoters. On the other hand, ACR markedly stimulated the activity of a retinoic acid response element-CAT reporter when the cells were cotransfected with a RARbeta expression vector. A hypothetical model explaining these two phases is presented. The diverse effects that we obtained with ACR suggest that this agent might be useful in the chemoprevention and/or therapy of human SCCs.

Topics: Antineoplastic Agents; Apoptosis; Blotting, Western; Carcinoma, Squamous Cell; Cell Cycle; Cell Division; Cell Line, Tumor; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; DNA-Binding Proteins; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; ErbB Receptors; Esophagus; G1 Phase; Genes, Reporter; Genetic Vectors; Humans; Inhibitory Concentration 50; Phosphorylation; Resting Phase, Cell Cycle; Retinoblastoma Protein; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; STAT3 Transcription Factor; Time Factors; Trans-Activators; Transcription, Genetic; Transforming Growth Factor alpha; Tretinoin

Retinoic acid receptor-beta(2) (RAR-beta(2)) expression is suppressed in oral premalignant lesions and head and neck squamous cell carcinomas (HNSCCs). This study was conducted to determine whether RAR-beta(2) gene expression in such lesions can be silenced by promoter methylation.. RAR-beta(2) methylation was analyzed in DNA samples from 22 pairs of primary HNSCC and adjacent normal epithelium, 124 samples of oral leukoplakia, and 18 HNSCC cell lines using methylation-specific PCR. RAR-beta(2) promoter was methylated in 67, 56, and 53% of HNSCC tumors, HNSCC cell lines, and microdissected oral leukoplakia specimens, respectively. RAR-beta(2) hypermethylation was confirmed by sodium bisulfite-PCR combined with restriction enzyme digestion analysis and by random cloning and sequencing of bisulfite-treated DNA isolates.. Significantly higher RAR-beta(2) hypermethylation levels were found in tumor tissue compared with adjacent normal tissue (P = 0.002). RAR-beta(2) methylation in the cell lines was correlated with loss of RAR-beta(2) expression (P = 0.013) and inversely related to the presence of mutated p53 (P = 0.025). The demethylating agent 5-aza-2'-deoxycytidine (5-aza-CdR) restored RAR-beta(2) inducibility by all-trans-retinoic acid (ATRA) in some of the cell lines, which posses a methylated RAR-beta(2) promoter. In some cell lines, this effect was associated with increased growth inhibition after combined treatment with 5-aza-CdR and ATRA.. RAR-beta(2) silencing by methylation is an early event in head and neck carcinogenesis; 5-Aza-CdR can restore RAR-beta(2) inducibility by ATRA in most cell lines, and the combination of 5-aza-CdR and ATRA is more effective in growth inhibition than single agents.

Topics: Adult; Aged; Aged, 80 and over; Base Sequence; Carcinoma, Squamous Cell; Cell Division; Cell Line, Tumor; Cloning, Molecular; DNA Methylation; DNA Primers; DNA, Neoplasm; Female; Gene Silencing; Head and Neck Neoplasms; Humans; Leukoplakia, Oral; Male; Middle Aged; Molecular Sequence Data; Mouth Neoplasms; Polymerase Chain Reaction; Precancerous Conditions; Promoter Regions, Genetic; Receptors, Retinoic Acid; Tretinoin

Retinoids have shown clinical efficacy in cancer chemoprevention and therapy presumably by modulating the growth, differentiation, and apoptosis of normal, premalignant, and malignant cells. To better understand the mechanisms by which retinoids exert their effects, we used a high-throughput Western blotting method (Becton-Dickinson PowerBlot) to evaluate changes in the levels of cellular signaling proteins in head and neck squamous cell carcinoma cells treated with the cytostatic all-trans-retinoic acid or with the proapoptotic retinoids 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid or N-(4-hydroxyphenyl)retinamide. Treatments of the head and neck squamous cell carcinoma cells with these retinoids for 24 h resulted in increased levels of 14, 22, and 22 proteins and decreased levels of 5, 10, and 7 proteins, respectively. The changes in the levels of the following proteins were confirmed by conventional western immunoblotting: all-trans-retinoic acid increased ELF3, topoisomerase II alpha, RB2/p130, RIG-G, and EMAPII and decreased MEF2D and cathepsin L. N-(4-Hydroxyphenyl)retinamide up-regulated ELF3, c-Jun, Rb2/p130, JAK1, p67phox, Grb2, O(6)-methylguanine-DNA methyltransferase, and Ercc-1. 6-[3-(1-Adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid increased Rb2/p130, c-Jun, Sp1, Sin, and tomosyn and decreased cathepsin L, Mre11, and topoisomerase II alpha. Some of these proteins were also modulated by these retinoids in other human cancer cell lines. A subset of the proteins were modulated similarly by the different retinoids, whereas changes in other proteins were unique for each retinoid. These results suggest that the mechanisms by which these retinoids modulate proteins are distinct but may overlap. Some of the retinoid-modulated proteins identified in this study may be novel candidates for mediating different responses to retinoids.

Topics: Antineoplastic Agents; Blotting, Western; Carcinoma, Squamous Cell; Cell Line, Tumor; Fenretinide; Head and Neck Neoplasms; Humans; Neoplasm Proteins; Retinoids; Tretinoin

All-trans retinoic acid (RA), the principle biologically active form of vitamin A, is essential for many developmental process as well as homeostasis in the adult. Many lines of evidence also suggest that RA, acting through the RA receptors (RARs), can also suppress growth of tumors of diverse origin. To assess directly the role of the RARs in a model of epidermal tumorigenesis, we investigated the incidence of tumor formation using keratinocytes lacking specific RAR types. Our data suggest that loss of RARgamma, but not RARalpha, predisposed keratinocytes to v-Ha-Ras-induced squamous cell carcinoma. We also found that ablation of RARgamma, but not RARalpha, abolished RA-induced cell cycle arrest and apoptosis in these keratinocytes. Reconstitution of receptor expression into RAR-null cells restored sensitivity to RA, and reversed the tumorigenic potential of receptor-deficient keratinocytes. These data strongly support a tumor suppressor effect for the RARs, in particular endogenous RARgamma, in murine keratinocytes.

Topics: Animals; Apoptosis; Blotting, Western; Carcinoma, Squamous Cell; Cell Cycle; Cell Line, Tumor; Cell Nucleus; COS Cells; Genes, Reporter; Genes, Tumor Suppressor; Genotype; Keratinocytes; Mice; Mice, Transgenic; ras Proteins; Receptors, Retinoic Acid; Retinoic Acid Receptor gamma; Retroviridae; Skin Neoplasms; Time Factors; Tretinoin

Squamous cell carcinoma (SCC) is the most prevalent form of epithelial cancer. SCC results when normal epithelial cells undergo multiple neoplastic changes that culminate in the evolution of an invasive cancer. Retinoids are commonly used as chemopreventive and treatment agents in skin cancer; however, SCC progression is accompanied by a gradual loss of retinoid responsiveness. The synthetic retinoid N-(4-hydroxyphenyl)retinamide (HPR) has shown promising anti-neoplastic activity in a variety of tumor cells, including those that are resistant to all-trans retinoic acid (t-RA). We investigated the effect of HPR on growth and apoptosis of squamous cells at different stages of carcinogenesis. We then determined if retinoic acid receptor (RAR) overexpression affected the outcome of HPR treatment. To model SCC malignant progression, we used a panel of murine keratinocytes representing different stages of squamous cell carcinogenesis. This panel consisted of primary keratinocytes, SP1 and 308 papilloma cell lines, the PAM-212 squamous carcinoma cell line, and the spindle I7 cell line. With the exception of the primary keratinocytes, all cells were unresponsive to t-RA treatment. Pharmacological concentrations of HPR were non-cytotoxic to all keratinocytes tested and HPR sensitivity was stage-dependent, with the papilloma cell lines being the most sensitive, and the spindle cells being the most resistant. Overexpression of RARgamma in SP1 papilloma cells enhanced growth suppression and apoptosis induction by HPR. HPR-induced growth suppression was accompanied by a simultaneous block in the G(1) phase of the cell cycle in RAR-transduced and control SP1 cells and differential regulation of cell cycle and apoptotic mediators.

Topics: Animals; Antineoplastic Agents; Apoptosis; Benzimidazoles; Carcinoma, Squamous Cell; Cell Division; Cell Transformation, Neoplastic; Cells, Cultured; Fenretinide; G1 Phase; Keratinocytes; Mice; Mice, Inbred BALB C; Neoplasm Staging; Nevus, Spindle Cell; Papilloma; Propidium; Receptors, Retinoic Acid; Ribonucleases; Tretinoin

To study the effects of 9-cis-retinoic acid (9-cis-RA) on cell cycle and expression of cyclin D1 and cdk4 in lung cancer cells.. 9-cis-RA (1 x 10(-6) mol.L-1) was used to treat lung cancer cells for 24 h; Flow cytometry (FCM) was used to detect the percent of G0/G1 phase and S phase cells of three groups including blank control, DMSO control and 9-cis-RA groups; RT-PCR was used to analyze the expression changes of cyclin D1 and cdk4 before and after treatment with 9-cis-RA in lung cancer cells.. The percent of G0/G1 phase cells of 9-cis-RA groups was significantly higher than that of the control groups (P < 0.01 or P < 0.05) and the percent of S phase cells of 9-cis-RA groups was lower than that of the control groups (P < 0.01 or P < 0.05); the expression of cyclin D1 of PG, SPC-A1 and L78 cells was decreased (P < 0.01) and the expression of cdk4 of PG, A549 and L78 cells was also decreased (P < 0.01) after treatment with 9-cis-RA.. Most of the proliferation and the expression of cyclin D1 and cdk4 of PG, A549, SPC-A1 and L78 were inhibited by 9-cis-RA.

Topics: Adenocarcinoma; Alitretinoin; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Division; Cell Line, Tumor; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinases; G1 Phase; Humans; Lung Neoplasms; Proto-Oncogene Proteins; Resting Phase, Cell Cycle; S Phase; Tretinoin

The aim of this study was to confirm if catabolism of all-trans retinoic acid (RA) is enhanced by type I cellular retinoic acid binding protein (CRABP-I) expression and to investigate the effect of this enhanced catabolism on cell proliferation of the head and neck squamous cell carcinoma (HNSCC) cell line, AMC-HN-7. We also analyzed the effects of CRABP-I on RA-induced retinoic acid receptor (RAR) activity. The expression of the CRABP-I in stably transfected AMC-HN-7 cell lines (HN7-BPIa and HN7-BPIb) resulted in a lower sensitivity to administered RA compared with that of controls in a clonogenic assay. HN7-BPIs cells showed an increased amount of polar metabolites of RA in thin-layer chromatography. The transcriptional activity of the reporter plasmid RARE(DR5)-tk-CAT after the treatment of RA was lesser in HN7-BPIs than in controls. These results suggest that the increased CYP26-mediated catabolism of RA by CRABP-I transfection might decrease the amount of RA that is accessible to the nuclear receptors and make HNSCC cells resistant to RA.

Topics: Blotting, Western; Carcinoma, Squamous Cell; Cell Division; Chloramphenicol O-Acetyltransferase; Chromatography, Thin Layer; Cytochrome P-450 Enzyme System; Head and Neck Neoplasms; Humans; Receptors, Retinoic Acid; Retinoic Acid 4-Hydroxylase; Reverse Transcriptase Polymerase Chain Reaction; Transfection; Tretinoin; Tumor Stem Cell Assay

Retinoids have been shown the most powerful inducers of transglutaminase activity, a well known marker of differentiation. In this work, we tested the effects of all-trans retinoic acid and EGF, used alone or in combination, on transglutaminase activity in a squamous, epithelial carcinoma cell line, HEp-2. We demonstrated that nanomolar EGF further enhances transglutaminase activity previously induced by all-trans retinoic acid. Confocal laser scanning microscopy revealed functional changes in transglutaminase activity localisation, at first restricted to the outermost region of cytosol, then diffused both in the membrane region and extracellular space. RT-PCR showed the presence of mRNA transcripts of different transglutaminases (1, 2, 3). Transglutaminase 2 expression was increased by either all-trans retinoic acid or EGF, and further up-regulated by the simultaneous addition of both substances. These effects were confirmed by Western blotting with transglutaminase 2 specific antibody. The results obtained by combined use of retinoic acid and EGF suggest that transglutaminase activity and expression are differently regulated, and that EGF-signalling can be involved in differentiation of epithelial carcinoma cells induced by retinoids.

Topics: Carcinoma, Squamous Cell; Cell Differentiation; Cell Line, Tumor; Epidermal Growth Factor; Gene Expression Regulation, Enzymologic; GTP-Binding Proteins; Humans; Protein Glutamine gamma Glutamyltransferase 2; Transglutaminases; Tretinoin; Up-Regulation

The chemotherapeutic agent retinoic acid (RA) and its derivatives have been used to treat many tumor types. The antitumor effects of retinoids are in part due to their ability to inhibit proliferation of cancer cells. However, smokers receiving dietary vitamin A and beta carotene in chemoprevention studies had a higher incidence of lung cancer. These studies imply that lower doses of retinoids may have tumor-promoting activity. The effects of RA are mediated by a family of ligand-dependent transcription factors, the retinoic acid receptors (RARs) and the retinoid X receptors (RXR). We examined the effects of low- and high-dose RA treatment on proliferation of human squamous cell carcinoma lines in vitro. Low concentrations of RA (20 nM) increased proliferation of SCC lines by epidermal growth factor (EGF) activation of the mitogen-activated protein kinase ERK1. These changes were accompanied by increased expression of S- and G(2) phase cyclins and cyclin-dependent kinases (cdk), increased Rb phosphorylation, and increased E2F-1 DNA binding activity. In contrast, higher doses of RA (40 nM to 1 micro M) inhibited ERK1 expression, caused accumulation of G(1) phase cyclins and cdks, decreased Rb phosphorylation, and increased Rb/E2F-1 association. Overexpression of ERK1 or dominant negative ERK1 was sufficient to reproduce the effects of low- and high-dose RA, respectively. Treatment with receptor selective retinoids revealed that both RARalpha and RARgamma mediated the effects of RA on SCC lines. We concluded that low-dose RA induced proliferation by increased EGF signaling while higher concentrations inhibited cell division by decreasing ERK1 activation.

Topics: Apoptosis; Carcinoma, Squamous Cell; Cell Division; Humans; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Tretinoin; Tumor Cells, Cultured

RA175, a new immunoglobulin superfamily member, is preferentially expressed during differentiation of P19 embryonic carcinoma (EC) cells induced by retinoic acid. In the present study, we isolated mouse RA175 cDNA in its entirety and showed that RA175 is the mouse ortholog of TSLC1, a tumor suppressor gene in human lung cancer. RA175/TSLC1 was localized in the adherent region of human lung squamous carcinoma cells and in the differentiated P19 EC cells. RA175/TSLC1 showed homophilic trans-interaction activity in a Ca(2+)-independent manner. RA175/TSLC1 was preferentially expressed in the polarized cells lining the lumen of developing mouse lung epithelium. This suggests that RA175/TSLC1 is a cell adhesion molecule that is acting as a tumor suppressor gene in the metastasis of lung tumors. RA175/TSLC1 may be necessary for cells to remain tightly associated in the epithelium, thereby suppressing metastasis.

Topics: Animals; Cadherins; Calcium Signaling; Carcinoma, Squamous Cell; Cell Adhesion; Cell Adhesion Molecule-1; Cell Adhesion Molecules; Cell Compartmentation; Cell Differentiation; DNA, Complementary; Humans; Immunoglobulins; Lung Neoplasms; Membrane Proteins; Mice; Molecular Sequence Data; Nectins; Neoplasm Metastasis; Phosphoproteins; Protein Structure, Tertiary; Proteins; Respiratory Mucosa; Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid; Tretinoin; Tumor Cells, Cultured; Tumor Suppressor Proteins; Zonula Occludens-1 Protein

Retinoids play essential roles in the regulation of cell differentiation and in the proliferation of various epithelial tissues, and atRA is one such active metabolite of retinoids. However, despite the known functions of atRA, its clinical applications are limited due to the induced metabolism by the specific cytochrome P-450s in the liver. To overcome the limitation, parenteral administration of atRA-loaded biodegradable microspheres, the PDLLA/PLE microspheres containing atRA, was suggested previously. We evaluated chemotherapeutic efficacy of atRA-loaded microspheres in a human head-and-neck xenograft/nude mouse model. When atRA-loaded microspheres were administered s.c. at 200 mg/kg body weight to athymic nude mice, plasma concentration of atRA could be maintained in a range of 1.2 to 3.7 x 10(-8) M for 4 weeks. As a result, the tumor volume of human head-and-neck cancer was reduced compared to the control group by 51.3% (p < 0.01) at 14 days and by 49.2% (p < 0.05) at 28 days.

Topics: Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Drug Carriers; Drug Delivery Systems; Female; Head and Neck Neoplasms; Humans; In Situ Nick-End Labeling; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Microspheres; Neoplasms, Experimental; Survival Rate; Transplantation, Heterologous; Tretinoin; Tumor Cells, Cultured

A cell line, AMOS-III has been established from the surgically resected specimen of an untreated primary human oral squamous cell carcinoma of the floor of mouth from a chronic smokeless tobacco consumer. Immunocytochemical analysis showed epithelial specific antigen, cytokeratins 5, 10, 13 and 16 and integrin alpha(6) markers in AMOS-III cells, confirming the epithelial lineage of the cell line. Analyses of morphology, ultrastructure, karyotype, anchorage independent growth and immunocytochemical properties of the cell line demonstrated the transformed phenotype of epithelial cells. AMOS-III cells have doubling time of 42-44 h. Giemsa-banding patterns of chromosomes confirmed the human origin of the AMOS-III cells. Molecular analysis of cancer-related gene products, p53 and p21(cip1/waf1) showed the presence of wild type p21(cip1/waf1) and truncated p53 proteins. The molecular mechanism underlying the action of retinoids in preventing the occurrence of second primary tumors in oral cancer patients remain to be clearly defined. Treatment of AMOS-III cells with all-trans retinoic acid (ATRA) at 10(-4) microM resulted in 81% cell death. ATRA treatment resulted in enhanced expression of p21(cip1/waf1), nuclear translocation of retinoic acid receptors and apoptotic cell death. Thus, this cell line provides an in vitro model for elucidating the mechanism involving p53 inactivation and p21(cip1/waf1) overexpression in smokeless tobacco-induced oral cancer. Furthermore, the ATRA responsiveness of the cell line underscores its potential utility in identifying the retinoid responsive molecular targets in oral cancer cells.

Topics: Antioxidants; Apoptosis; Biomarkers, Tumor; Carcinoma, Squamous Cell; Cell Line, Tumor; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; DNA Mutational Analysis; Genes, p53; Humans; Immunoblotting; Karyotyping; Male; Microscopy, Confocal; Middle Aged; Mouth Neoplasms; Tobacco, Smokeless; Tretinoin

Peroxisome proliferator-activated receptor gamma (PPARgamma) heterodimerises with retinoid X receptor alpha (RXRalpha) and is thought to be a novel therapeutic target for human malignancies. We evaluated the ability of troglitazone (TRO) alone or in combination with 9-cis retinoic acid (9CRA), ligands of PPARgamma and RXRalpha, respectively, to inhibit the growth of oesophageal squamous cell carcinoma (OSCC). All 10 tested OSCC cell lines of a KYSE series expressed PPARgamma and RXRalpha at both the mRNA and protein levels. In four tested cell lines, TRO inhibited growth, and a synergistic effect was observed with simultaneous 9CRA application. In KYSE 270 cells, a luciferase reporter assay showed that the simultaneous application of TRO and 9CRA to the cells increased the relative luciferase activity approximately 20-fold compared with the controls without TRO or 9CRA application. In this cell line, flow cytometry demonstrated that combined treatment with TRO and 9CRA greatly increased the sub-G1 phase, and Hoechst 33342/propidium iodide (PI) staining showed that apoptotic cell death was mainly induced through ligand treatment. In addition, implanted tumours in nude mice showed significant inhibition of tumour growth when treated with TRO. These results suggest that the PPARgamma/RXRalpha heterodimer may be a new therapeutic target for OSCC.

Topics: Alitretinoin; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Blotting, Western; Carcinoma, Squamous Cell; Caspases; Cell Division; Chromans; Drug Evaluation; Esophageal Neoplasms; Humans; Receptors, Cytoplasmic and Nuclear; Receptors, Retinoic Acid; Retinoid X Receptors; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Thiazolidinediones; Transcription Factors; Tretinoin; Troglitazone; Tumor Cells, Cultured

Vitamin A and D(3) have a very strong differentiation induction effect.. We examined the anti tumor effect on head and neck squamous cell carcinoma (HNSCC) by treatment with several vitamins having strong differentiation induction effects in vitro.. We used KB cell that an oral floor squamous cell carcinoma, vitamins as all-trans retinoic acid (ATRA), 4-[3,5-bis (trimethylsilyl) benzamido] benzoic acid (TAC-101), 1alpha,25(OH)(2)D(3) (calcitriol) and 22-oxa-1,25-(OH)(2)D(3) (OCT). We determined receptors of vitamin A and D(3) using RT-PCR. Furthermore, we investigated the proliferation of tumor cells in concentration dependency using [3H]TdR uptake method, apoptosis and apoptosis related factors using TUNEL method and real-time PCR, cell cycle changes using flow cytometry, changing of the sensitivity of using MTT method, cytokine production and the angiogenesis factor using ELISA, by treatment with these vitamins.. The deficit of RAR-beta was found in the KB cell. Each vitamin suppressed the cell proliferation, induced apoptosis, and cell cycle arrest, upregulated sensitivity of the chemotherapeutics drugs and downregulated several angiogenesis factors and an apoptotic factor; survivin.. These results support the idea that vitamin A, D(3) and their derivatives are useful for preventing and/or treating patients with HNSCC.

Topics: Angiogenesis Inducing Agents; Antimetabolites, Antineoplastic; Antineoplastic Agents; Apoptosis; Calcitriol; Carcinoma, Squamous Cell; Cell Culture Techniques; Cell Cycle; Cell Line, Tumor; Cisplatin; Cytokines; Flow Cytometry; Fluorouracil; Head and Neck Neoplasms; Humans; In Situ Nick-End Labeling; Receptors, Cytoplasmic and Nuclear; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tretinoin; Vitamin A; Vitamin D

Angiogenesis, an essential step in the development of neoplasia, is a complex process that involves the interaction of tumor cells with stromal cells. Tumor-associated macrophages (TAMs) can participate in the induction of angiogenesis and are of prognostic value in some neoplasms. Specimens from head and neck squamous cell carcinomas (HNSCC) often contain large numbers of TAMs. In addition, experimental evidence has demonstrated that HNSCC tumor cells can attract and activate macrophages to participate in the expression of the angiogenic phenotype. These findings suggest that antiangiogenic therapies for HNSCC must include strategies that will block the recruitment of macrophages into the tumor microenvironment. We investigated the ability of retinoic acid (RA) to modulate the ability of tumor cells to recruit and activate monocytes for participation in tumor angiogenesis. Owing to a decrease in the secretion of MCP-1 and transforming growth factor-beta 1 (TGF-beta 1), tumor cells treated with RA were unable to induce peripheral blood monocyte (PBM) chemotaxis. Also, as a result of the decrease in TGF-beta 1 secretion, RA-treated tumor cells were unable to activate macrophages for secretion of vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8). In addition to its affects on tumor cells, RA also directly altered the ability of monocytes to participate in the tumor angiogenesis process. PBM exposed to RA were unable to migrate toward inducers of PBM such as MCP-1 and TGF-beta 1. Finally, RA decreased the ability of tumor-activated macrophages to secrete IL-8 and VEGF. These data demonstrate alternative mechanisms by which RA may modulate angiogenesis in the tumor microenvironment. In addition, it underscores the necessity to develop antiangiogenic treatment protocols that can block each of the ways in which new blood vessel growth is induced in tumor microenvironments.

Topics: Carcinoma, Squamous Cell; Cell Movement; Endothelial Growth Factors; Head and Neck Neoplasms; Humans; Interleukin-8; Lymphokines; Macrophage Activation; Macrophages; Monocytes; Neovascularization, Pathologic; Phenotype; Tretinoin; Tumor Cells, Cultured; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Retinoids show promise in the treatment of various (pre)malignancies, including head and neck squamous cell carcinoma (HNSCC). It has been shown that metabolic pathways of retinoids are important in their anticancer effect and that these pathways may change during HNSCC carcinogenesis. We have previously reported that HNSCC cells have a 17-fold greater turnover rate of retinoic acid (RA) than normal oral keratinocytes from noncancer controls, and that the formation of polar metabolites such as 4-oxo-RA and 4-hydroxy-RA is only seen in HNSCC cell lines. We aimed to establish whether this altered retinoid metabolism is an intrinsic characteristic of HNSCC patients.. The normal mucosa of cancer and noncancer patients was the source of keratinocyte cultures. The cells were exposed to RA for various time periods, and the levels of various retinoids were measured in the culture medium and cell pellets with reverse-phase liquid chromatography.. Cells from cancer patients were morphologically normal and showed no genetic aberrations (i.e. loss of heterozygosity). The RA turnover rate in normal oral keratinocytes of cancer patients was 15 times higher (p = 0.003) than that in normal oral keratinocytes of noncancer controls, with average turnover rates of 218.6 and 14.8 pmol/mg protein/h, respectively. Specific profiles of RA metabolites were similar.. The observed higher RA metabolism in noncancer cells of HNSCC patients suggests that individuals with a relatively high RA turnover have an increased risk of developing HNSCC.

Topics: Adult; Aged; Carcinoma, Squamous Cell; Cells, Cultured; Female; Head and Neck Neoplasms; Humans; Keratinocytes; Loss of Heterozygosity; Male; Middle Aged; Mouth; Tretinoin

All-trans retinoic acid (ATRA) suppresses growth of cervical dysplasias in vivo, although the sensitivity to retinoids is frequently lost during cervical carcinogenesis. It has been suggested that prolonged treatment or use of higher doses of retinoids might offer favorable response rates. We found SiHa cervical squamous carcinoma cells that were virtually resistant to ATRA-induced growth-inhibitory effects at physiological doses (10(-7 to) 10(-6) M) to be more responsive at pharmacological doses (10(-5 to) 10(-4) M). The growth inhibition by high-dose (10(-4) M) ATRA was associated with a sustained activation of interferon regulatory factor 1 (IRF-1), while a low dose (10(-6) M) of ATRA activated IRF-1 only transiently. Antisense IRF-1 inhibited the high-dose (10(-4) M), ATRA-mediated growth arrest; forced expression of IRF-1 caused a significant reduction in cell growth. High-dose (10(-4) M) ATRA increased binding of NF-kappaB and STAT1 proteins to sequences that originated from the IRF-1 promoter region, while low-dose (10(-6) M) ATRA induced only NF-kappaB binding. A delayed tyrosine phosphorylation of the signal transducer and activator of transcription-1 (STAT1) was observed after high-dose (10(-4) M) but not low-dose (10(-6) M) ATRA treatment. In agreement with this, induction of IRF-1 mRNA by ATRA was only modest and transient in a STAT1 knockout cell line, suggesting the importance of STAT1 in sustained IRF-1 expression. Our data showed that ATRA is capable of inducing dose-dependent cellular changes, which might be appropriate to overcome resistance to retinoids that frequently develops during cervical carcinogenesis.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Division; DNA-Binding Proteins; Dose-Response Relationship, Drug; Female; Gene Expression Regulation, Neoplastic; Humans; Interferon Regulatory Factor-1; NF-kappa B; Oligonucleotides; Phosphoproteins; Phosphorylation; Promoter Regions, Genetic; STAT1 Transcription Factor; Trans-Activators; Tretinoin; Tumor Cells, Cultured; Uterine Cervical Neoplasms

Indomethacin, an NSAID capable of inhibiting the effect of both cyclooxygenase and lipooxygenase, has been reported to repress the growth of breast cancer, skin cancer and head & neck cancer, etc. Inhibition in the some cell lines of oral squamous cell carcinoma (OSCC) has also been reported. The purpose of this study was primarily to explore the cellular response of human OSCC lines after indomethacin or retinoic acid (RA) treatment and its correlation to apoptosis phenomenon.. Five human OSCC cell lines--KB, SCC15, SCC25, OEC-M1 and OC2--were used for this in vitro study. By direct cell number counting, the cellular response was observed under incremental indomethacin concentrations of 50 microM, 100 microM, 200 microM and 400 microM, in order to select the most appropriate concentration for further study. Then 200 microM indomethacin and all-trans RA at 1 microM were used in the 2nd experiment to explore the intensity of their inhibitory effects individually and potential synergistic inhibition when exerted together. While in the 3rd part, TdT-mediated-dUTP nick-end labeling (TUNEL) method was used for in situ apoptosis assay to see if the apoptosis rate varied with these two agents.. All 5 cell lines constantly showed growth suppression with positive dosage effect of indomethacin. Synergistic inhibition by combined treatment of indomethacin and RA was seen in RA responsive lines of SCC15 and SCC25, whereas other RA-resistant clones showed no synergism of this combined treatment. The in situ detection of apoptosis by TUNEL assay revealed a significantly higher ratio of apoptotic cells in the indomethacin/RA treated SCC15 and SCC25 than in controls.. The study provides the value of further exploration on the mechanism of how indomethacin inhibiting cancer cell growth and how RA-sensitive OSCC cell lines are synergistically suppressed by conjoint treatment of RA and indomethacin. This study also highlights the value to see how the apoptotic pathway responds differently to the indomethacin/RA treatment.

Topics: Apoptosis; Carcinoma, Squamous Cell; Drug Synergism; Humans; Immunohistochemistry; Indomethacin; Mouth Neoplasms; Tretinoin; Tumor Cells, Cultured

While retinoids have been demonstrated to inhibit growth of many tumor cells, including SCC cells, the molecular mechanism by which retinoids suppress growth has not been elucidated. We previously found that the growth of SCC cells was significantly inhibited by all-trans-retinoic acid (all-trans-RA) treatment, and this inhibition was dependent on the binding and activation of RARs. These nuclear receptors bind retinoids and alter the rate of transcription of specific genes. To identify targets of the activated RARs which mediate growth inhibition, we growth arrested SCC-25 cells in G-0 and examined the effect of all-trans-RA on synchronized SCC-25 cells. All-trans-RA inhibited G-1 progression in quiescent SCC-25 cells stimulated by FBS. More specifically, we found that the all-trans-RA execution point maps to mid/late G-1, 6 to 10 h after stimulation. Using this synchronized cell system, we examined the expression of cell cycle regulatory genes in quiescent SCC-25 cells stimulated with FBS and treated with all-trans-RA. We found few changes in expression of these genes which could account for all-trans-RA inhibition of SCC-25 cell growth. In order to compare the patterns of expression of a wider selection of genes in all-trans-RA treated and non-treated SCC-25 cells, we have used expression array technology. We successfully performed expression profiling experiments on the Atlas Human cDNA arrays which contain 1176 human genes. We have identified several up-regulated and several down-regulated gene expression changes mediated by all-trans-RA treatment in synchronized SCC-25 cells. This novel information will be useful in defining the mechanism by which retinoids suppress the growth of SCC cells.

Topics: Aged; Animals; Carcinoma, Squamous Cell; Cattle; Cell Cycle; DNA, Complementary; Fetal Blood; G1 Phase; Gene Expression; Gene Expression Profiling; HSC70 Heat-Shock Proteins; HSP70 Heat-Shock Proteins; Humans; Insulin-Like Growth Factor Binding Protein 1; Insulin-Like Growth Factor Binding Protein 3; Male; Mitogen-Activated Protein Kinases; Oligonucleotide Array Sequence Analysis; Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Sulfur Radioisotopes; Time Factors; Tongue Neoplasms; Tretinoin; Tumor Cells, Cultured

All-trans retinoic acid (RA) can be catabolized to polar metabolites by microsomal P450s (P450). The aim of this study was to confirm if retinoic acid 4-hydroxylase (CYP26) is a P450 induced by RA and to investigate the role of cellular RA binding proteins (CRABPs), using a slow catabolizer, AMC-HN-4, and a rapid catabolizer, AMC-HN-6. Also, we analyzed the effect of RA catabolism on cell proliferation of head and neck squamous cell carcinoma (HNSCC) in vitro and in vivo. Both cell lines weakly expressed CYP26 and CRABPs, but RA induced CYP26 only in AMC-HN-6. The sensitivity to RA was variable by the amount of CYP26, and the rapid catabolism by CYP26 made AMC-HN-6 resistant to RA in vitro. In addition, The RA had a stronger effect on the inhibition of tumor growth of AMC-HN-4 than that of AMC-HN-6 in vivo. Conclusively, the CYP26 activity might be one essential factor for the RA sensitivity, but in cells showing induction of CYP26, the RA sensitivity is inversely related to the rate of RA catabolism.

Topics: Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Division; Chromatography, High Pressure Liquid; Culture Media; Cytochrome P-450 Enzyme System; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Head and Neck Neoplasms; Humans; Kinetics; Mice; Mice, Nude; Receptors, Retinoic Acid; Retinoic Acid 4-Hydroxylase; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Transplantation, Heterologous; Tretinoin; Tumor Cells, Cultured

Retinoids have been shown to inhibit the growth of squamous cell carcinoma and other malignancies. They have also been shown to alter gap junctional intercellular communication (GJIC) and the expression of connexins, the protein subunits of gap junctions. We report in this study that the alteration of GJIC by retinoids may be directly related to inhibitory effects on cell growth.. SCC-13 cells were treated with all-trans retinoic acid (tRA) and 13-cis retinoic acid (cRA) at 10(-7) and 10(-6) M concentrations in culture. No treatment and ethanol vehicle controls were included for each experiment. Serial cell counts of parallel cultures were performed to determine cell growth. The parachute technique was performed in combination with fluorescence activated cell sorting (FACS) analysis to determine GJIC. Northern and Western blot analysis were performed to assess connexin mRNA and protein expression.. The growth rate was inhibited for cells treated with tRA (10(-6) M) (P < 0.05) and cRA (10(-6) M) (P = 0.068) vs. vehicle control. GJIC was significantly inhibited with both tRA (10(-7) and 10(-6) M) (P < 0.001) and cRA (10(-7) and 10(-6) M) (P < 0.001) at 24, 48, and 96 h as determined by FACS analysis. To correlate GJIC with cell growth, we studied the effect of glycyrrhetinic acid, a known inhibitor of GJIC. Glycyrrhetinic acid also significantly inhibited cell growth (P < 0.05) vs. control. Connexin 26 and connexin 43 mRNA and protein expression were not significantly altered after retinoid treatment.. Retinoic acids inhibit both cell growth and GJIC in SCC-13 cells. Retinoids may inhibit cell growth through alteration of GJIC in SCC-13 cells.

Topics: Blotting, Northern; Blotting, Western; Carcinoma, Squamous Cell; Cell Communication; Cell Division; Connexin 26; Connexin 43; Connexins; Flow Cytometry; Gap Junctions; Glycyrrhizic Acid; Isotretinoin; Logistic Models; Retinoids; RNA, Messenger; Skin Neoplasms; Tretinoin; Tumor Cells, Cultured

Topics: Acne Vulgaris; Carcinoma, Squamous Cell; Diagnosis, Differential; Follow-Up Studies; Humans; Laryngeal Neoplasms; Male; Middle Aged; Neck; Radiation Dosage; Radiodermatitis; Radiotherapy; Risk Assessment; Severity of Illness Index; Tretinoin

Four human cutaneous squamous cell carcinoma (SCC) cell lines and normal human epidermal keratinocyte (NHEK) cells from two donors were examined for sensitivity to the synthetic retinoid 6-[3-(1 -adamantyl)-4-hydroxyphenyl]-2-naph-thalene carboxylic acid (CD437) alone or in combination with other agents. CD437 promoted rapid (within 2 h) apoptosis in SCC cells and G1 arrest in NHEK cells. G1 arrest in NHEK cells was sustained for 48 h while apoptosis occurred in approximately 60% of SCC cell after 24 h. Apoptosis could not be inhibited by nuclear retinoic acid receptor antagonists or cycloheximide, indicating CD437 was functioning in a receptor-independent manner. All-trans retinoic acid not only failed to induce apoptosis in SCC cells even at 20-fold higher concentration relative to the effective concentration of CD437; it also decreased the efficacy of CD437. Because of its differential effects on normal versus malignant keratinocytes, CD437 may be useful for the prevention or treatment of cutaneous SCC.

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Cell Cycle; Cell Division; Cell Line; DNA Fragmentation; Epidermis; G1 Phase; Humans; Keratinocytes; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins c-jun; Reactive Oxygen Species; Reference Values; Retinoids; Skin Neoplasms; Time Factors; Tretinoin

Expression of retinoic acid receptor beta (RARbeta) is reported to be absent or down-regulated in oral squamous cell carcinomas. Recently, we found that the growth-inhibitory effect of 9-cis-retinoic acid (9CRA) on oral squamous cell carcinoma may depend on the expression levels of endogenous RARbeta. In order to clarify the role of RARbeta in growth and differentiation, we transfected RARbeta expression vector into oral squamous carcinoma cell lines, HSC-4 and Ho-1-N-1. Both RARbeta-transfected cell lines displayed growth inhibition. Moreover, RARbeta-transfected clones underwent morphological changes, and RARbeta-transfected HSC-4 clones underwent apoptosis even in the absence of 9CRA treatment. In contrast, RARbeta-transfected Ho-1-N-1 clones exhibited cell cycle arrest without undergoing apoptosis initially; however, apoptosis was induced in these cells after 6 days of 9CRA treatment. RARalpha and RARgamma expression was reduced at both the protein and mRNA levels in RARbeta transfectants, whereas the expression of retinoid X receptor alpha (RXRalpha) was not altered. RARb transfectants exhibited alterations in the levels of cell cycle-associated proteins, histone acetyltransferase (HAT) and apoptosis-associated proteins. After 6 days of 9CRA treatment, RARbeta transfectants overexpressed Waf1 / Cip1 / Sdi1 / p21, Kip1 / p27, chk1, p300 / CBP, BAX, Bak, Apaf 1, caspase 3 and caspase 9. Conversely, E2F1, cdc25B and HDAC1 were down-regulated in these transfectants. In addition, histone H4 acetylation was induced in RARb transfectants. These findings suggest that histone acetylation mediated by histone acetyltransferase and p300 / CBP may play a role in the growth arrest and apoptosis induced by RARbeta transfection in oral squamous cell carcinoma.

Topics: Alitretinoin; Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Cell Cycle; Cell Division; Humans; Mouth Neoplasms; Neoplasm Proteins; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; RNA, Messenger; Transfection; Tretinoin; Tumor Cells, Cultured

Retinoids show promise in the treatment of various (pre)malignancies, including head and neck squamous cell carcinoma (HNSCC). Previous studies have shown that the metabolic pathways of retinoids are important in the anticancer effect of retinoids, and that these pathways may change during carcinogenesis. In the present study, we analyzed HNSCC cell lines (n = 11) and normal oral keratinocyte cultures (n = 11) by reverse-phase high-performance liquid chromatography and conducted growth inhibition assays. We demonstrate here that in contrast to normal oral keratinocytes, HNSCC cell lines: (a) had averaged a 17-fold greater turnover rate of all-trans-retinoic acid (RA); (b) had a 1.9-fold less RA-induced growth inhibition; (c) were able to form polar metabolites; and (d) were able to catabolize 4-oxo-RA. Furthermore, the mRNA expression of the RA-specific 4-hydroxylase, CYP26A1, was dramatically increased after RA-induction in the two HNSCC cell lines with the highest metabolism, was undetectable in normal keratinocytes, and was not inducible by RA. Next, introduction of CYP26A1 cDNA in a low-metabolizing HNSCC cell line resulted in an 11-fold higher turnover rate of RA and a 12-fold increase in the amount of polar metabolites, but it did not change sensitivity to RA. These observations point to fundamental changes in RA metabolism pathways during HNSCC carcinogenesis and may provide clues to a more rational approach for RA-mediated intervention.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Division; Cytochrome P-450 Enzyme System; Head and Neck Neoplasms; Humans; Keratinocytes; Mixed Function Oxygenases; Mouth; Retinoic Acid 4-Hydroxylase; RNA, Messenger; Transfection; Tretinoin; Tumor Cells, Cultured

Retinoids, analogues of vitamin A, can reverse premalignant lesions and prevent second primary tumors in patients with head and neck squamous cell carcinoma (HNSCC). The effects of retinoids are mediated by retinoic acid receptors (RARs) and retinoid X receptors (RXRs), which act as ligand-activated transcription factors. The regulation of cell growth, differentiation and retinoid metabolism in normal, premalignant and malignant cells by retinoids is thought to be a result of their effects on gene expression. We investigated mRNA expression of RARs (alpha, beta, and gamma) and RXR-beta by means of RNase protection and related this to retinoic acid (RA)-induced growth inhibition and RA turnover in four HNSCC cell lines (UM-SCC-14C, UM-SCC-22A, UM-SCC-35 and VU-SCC-OE). An RA-resistant subline of UM-SCC-35 was generated by exposure to increasing concentrations of RA for 8 months (designated UM-SCC-35R). RA turnover was determined on the basis of decreasing RA levels in the cells and culture medium after exposure to 1 microM RA. We found that RAR-gamma mRNA expression was strongly correlated with RA-induced growth inhibition (p = 0.016, R = 0.92) and RA turnover (p = 0.041, R = 0.86). RAR-beta transcript levels were reduced in three of five cell lines compared with normal mucosa, and these did not correlate with RA-induced growth inhibition and RA turnover. Expression of RAR-alpha and RXR-beta was not substantially altered in any of the cell lines. These findings suggest that in HNSCC cell lines RAR-gamma is the most important retinoid receptor for regulation of RA turnover rate and RA-induced growth inhibition.

Topics: Carcinoma, Squamous Cell; Head and Neck Neoplasms; Humans; Receptors, Retinoic Acid; Retinoic Acid Receptor gamma; RNA, Messenger; Tretinoin; Tumor Cells, Cultured

Retinoids inhibit the proliferation of several types of tumour cells, and are used for patients with several malignant tumours. In this study, we examined the effect of retinoic acids (RAs) on the invasive potentials of the oral squamous cell carcinoma (SCC) cells, BHY and HNt. BHY cells expressed all of retinoid nuclear receptors (RARalpha, beta, gamma, and RXRalpha) and cytoplasmic retinoic acid binding proteins (CRABP1 and CRABP2). HNt cells lacked the expression of RARbeta, but expressed other nuclear receptors and CRABPs. All-trans retinoic acid (ATRA) and 13-cis retinoic acid (13-cisRA) (10(-6)and 10(-7)M) inhibited the growth of the cells, but low-dose ATRA and 13-cisRA (10(-8)M) marginally affected the growth of the cells. Surprisingly, low-dose RAs enhanced the activity of tissue-type plasminogen activator (tPA), and activated pro-matrix metalloproteinases (proMMP2 and proMMP9). Activation of proMMP2 and proMMP9 was inhibited by aprotinin, a serine-proteinase, tPA inhibitor. Furthermore, low-dose RAs enhanced the in vitro invasiveness of BHY cells. These results indicate that low-dose RAs enhances the in vitro invasiveness of oral SCC cells via an activation of proMMP2 and proMMP9 probably mediated by the induction of tPA.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Division; Collagenases; Dose-Response Relationship, Drug; Enzyme Activation; Enzyme Precursors; Gelatinases; Humans; Isotretinoin; Matrix Metalloproteinase 9; Matrix Metalloproteinases, Membrane-Associated; Metalloendopeptidases; Mouth Neoplasms; Neoplasm Invasiveness; Receptors, Retinoic Acid; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinase-2; Tissue Plasminogen Activator; Tretinoin; Tumor Cells, Cultured; Urokinase-Type Plasminogen Activator

Topics: Administration, Topical; Antineoplastic Agents; Carcinoma, Squamous Cell; Humans; Isotretinoin; Organ Transplantation; Skin Neoplasms; Tretinoin

To investigate and compare the efficacy of all-trans retinoic acid (RA) and/or interferon-alpha (IFN-alpha) on premalignant and malignant models of cervical cancer.. Cell growth rate was examined after treatment for 4, 7, and 10 days with RA and/or IFN-alpha of human papillomavirus type 18 (HPV 18)-immortalized endo- and ectocervical cells, nontransformed serum-adapted cells, transformed cells, three adenocarcinoma, and three squamous cell carcinoma cell lines. The effect on epithelial differentiation by RA and IFN-alpha was examined in organotypic culture. Induction of apoptosis was examined by modified terminal transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL) and DNA fragmentation.. Cell growth rate was inhibited by RA, 84-96% in HPV 18-immortalized endocervical cells, SiHa, and ME180, 0% in OMC-4, and 18-62% in other cell lines; and by IFN-alpha about 75% in SiHa and ME180 and 14-40% in the other cell lines. Combining RA and IFN-alpha increased the antiproliferative effect in premalignant cell lines and some cancer cell lines except OMC-4, SiHa, and HT-3. In rafts, RA treatment reversed human endocervical cell metaplasia and HPV 18-immortalized endo- and ectocervical cell dysplastic epithelial differentiation. Interferon-alpha, not RA, treatment of HPV 18-immortalized endo- and ectocervical cells induced apoptosis.. Cell growth inhibition by treatment with RA, IFN-alpha, and their combination differentially depends on treatment type and time, cell origin, cell line, and oncogenic state. In a premalignant model of cervical carcinoma, RA reduces dysplastic differentiation and IFN-alpha induces apoptosis. These data confirm that these treatments may be effective for preventing or treating premalignant cervical lesions.

Topics: Adenocarcinoma; Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Cell Differentiation; Cell Division; Cell Line, Transformed; Cervix Uteri; Female; Humans; Interferon-alpha; Papillomaviridae; Tretinoin; Tumor Cells, Cultured; Uterine Cervical Neoplasms

The purpose of this study is to identify the cellular response ofretinoic acid-treated human oral cancer cell lines.. Seven human oral cancer cell lines KB, SCC4, SCC9, SCC15, SCC25, OEC-M1, OC1 and OC2 were used for cell culture experiments. Direct cell number counting method was utilized to evaluate cellular response of these human oral cancer cells at the presence or absence of all-trans RA at 1 mM.. Through 7-day observation, the cell population of SCC9, SCC15 and SCC25 of RA-treated groups decreased when compared with the non RA-treated groups. These three cell lines were further verified using [3H] thymidine incorporation DNA synthesis assay. KB, SCC4, OC1, OC2 and OEC-M1 cell lines did not show growth inhibition at the presence of RA at 1 mM.. The molecular event of how SCC9, SCC15 and SCC25 are inhibited by RA and how KB, OC1, OC2 and OECM1 are resistant to RA can be further explored on the basis of this study.

Topics: Carcinoma, Squamous Cell; Cell Division; DNA; Humans; Mouth Neoplasms; Thymidine; Tretinoin; Tumor Cells, Cultured

This study examined the role of the pulsed-dye laser (PDL) at 585 nm coupled with retinoic acid at therapeutic (5.0 mg/kg) and nontherapeutic (0.5 mg/kg) doses to delay the progression of cancer with a two-hit approach. The existing vasculature is selectively targeted by the laser, whereas retinoic acid inhibits future angiogenesis.. Randomized, prospective study in a murine model.. Twenty-five athymic nude mice were inoculated with oral squamous cell cancers on six flank sites and randomly divided into five groups: 1) control subjects, 2) treatment with 0.5 mg/kg retinoic acid (RA 0.5), 3) treatment with 5.0 mg/kg retinoic acid (RA 5.0), 4) treatment with RA 0.5 + PDL, and 5) treatment with RA 5.0 + PDL. The PDL groups received irradiation after inoculation. The retinoic acid was administered daily. The tumors were counted and measured for 14 days.. The control group developed visible tumors in 50% of the inoculation sites at 3 days compared with 3 days (RA 0.5) and 4 days (RA 5.0) for the retinoic acid groups and 9 days (RA 0.5 + PDL) and 10 days (RA 5.0 + PDL) for the laser treatment groups. There was no tumor growth until day 7 in the RA 5.0 + PDL group. The tumor volume was statistically different between the treatment groups.. This study demonstrated the superiority of a single treatment with the PDL coupled with retinoic acid to delay the progression of cancer when compared with treatment with retinoic acid alone, thus introducing a novel strategy in cancer control.

Topics: Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Combined Modality Therapy; Data Interpretation, Statistical; Disease Models, Animal; Laser Therapy; Lithotripsy, Laser; Mice; Mice, Nude; Mouth Neoplasms; Neoplasm Transplantation; Neoplasms, Experimental; Prospective Studies; Random Allocation; Time Factors; Tretinoin

Adenovirus-mediated p53 (AdCMVp53) gene therapy for cancer is currently undergoing phase III clinical trials. One problematic aspect of this therapy is that the current protocols result in low transduction of the therapeutic virus in vivo. To search new modalities that can enhance the effect of AdCMVp53 gene therapy, we focused on retinoids.. To study the effect of ATRA in combination with AdCMVp53 gene therapy, we pretreated head and neck squamous cell carcinoma (HNSCC) cells for 72 hours with a low-dose All-trans-retinoic acid (ATRA) (10-7 M-10-8 M) which will not affect the in vitro cell growth, and then infected the cells with low MOI (30MOI) AdCMVp53. In vitro cell proliferation assays, cell cycle assays were performed. Expression of p53 and p53-related gene products, BAX and p21, were examined.. The combined treatment with ATRA and Ad-p53 suppressed cell growth and induced apoptosis significantly more than AdCMVp53 treatment alone (P <.05). p53 expression significantly increased more after the combined treatment than after either treatment alone, at both the transcription and protein levels. In addition, increased expression of p21 and BAX, which are downstream gene products of p53, was observed in the combination. ATRA also enhanced the expression of green fluorescent protein (GFP) transduced by an adenovirus-cytomegalovirus (CMV)-GFP vector suggesting ATRA enhances adenovirus-CMV-promoted vectors through transcription.. Our results indicate that ATRA enhances AdCMVp53 expression through transcriptional mechanisms and can synergistically induce apoptosis in HNSCC cells. ATRA has a potential to enhance the effect of adenovirus-mediated p53 gene therapy for HNSCC.

Topics: Adenoviridae; Antineoplastic Agents; Blotting, Western; Carcinoma, Squamous Cell; Genes, p53; Genetic Therapy; Head and Neck Neoplasms; Humans; Transduction, Genetic; Tretinoin; Tumor Cells, Cultured

Retinoids' effects on cell growth and differentiation are mediated by nuclear retinoid receptors, which are ligand-activated transcription enhancing factors. Because the expression of the retinoic acid receptor beta (RARbeta) gene, which is located on chromosome 3p24, is diminished in premalignant and malignant tissues it has been proposed that it acts as a tumor suppressor. To test the hypothesis that RARbeta loss leads to retinoid resistance, we studied several karyotyped head and neck squamous carcinoma (HNSCC) cell lines (UMSCC-17A, -17B, -22A, -22B, and -38) with deletion of one chromosome 3p arm. RARbeta mRNA was neither detected nor induced by retinoic acid in these cells, whereas it was expressed and induced by retinoic acid in two other HNSCC cell lines (1483 and 183) without 3p deletion. Methylation of the RARbeta gene promoter was detected in the 17B and 22B cells that failed to express RARbeta but no methylation was found in 183A cells that did express RARbeta mRNA. Responsiveness of HNSCC cells to several retinoids in assays of growth inhibition and colony formation, was rank ordered as: 22B>1483>38>183>17B. Additionally, retinoid response elements were transactivated in 22B more efficiently than in 17B cells. These results indicate that loss of RARbeta expression does not necessarily lead to loss of growth inhibition by retinoids or to a block of retinoid signaling.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Division; Chromosome Deletion; Chromosomes, Human, Pair 3; DNA, Neoplasm; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Genes, Tumor Suppressor; Head and Neck Neoplasms; Humans; Promoter Regions, Genetic; Receptors, Retinoic Acid; Retinoids; RNA, Neoplasm; Transcriptional Activation; Tretinoin; Tumor Cells, Cultured

All-trans-retinoic acid (atRA) is a promising anticancer and antiwrinkle drug. However, its clinical application is limited because it is rapidly metabolized by the induced cytochrome P450 (P450). In this study, farnesol derivatives are proposed as new inhibitors to prevent P450-mediated metabolism. The farnesol derivatives were suc-farnesol and mal-farnesol, which were synthesized by the chemical conjugation of farnesol with succinic anhydride and maleic anhydride, respectively. The inhibition effects of farnesol, farnesoic acid, and farnesol derivatives on the atRA metabolism were evaluated in microsome and in AMC-HN-6 cells. In the microsome experiment, suc-farnesol and mal-farnesol strongly inhibited atRA metabolism at 10(minus;4) mol/L concentration by as much as 61% and 77%, respectively. In the cell experiment, the inhibition effects of farnesol derivatives on the atRA metabolism showed similar tendency as the results in the microsome experiment, even if the effect was somewhat decreased. Effects of farnesoic acid and farnesol, however, were not significant. This research suggests that carboxylic end groups, such as atRA and hydrophobicity, might be important factors causing the higher inhibition effect, and that derivatization of farnesol can be 1 method to develop new inhibitors of atRA metabolism.

Topics: Antimetabolites; Carcinoma, Squamous Cell; Cell Division; Dose-Response Relationship, Drug; Farnesol; Fatty Acids, Unsaturated; Humans; Maleic Anhydrides; Microsomes; Succinic Anhydrides; Tretinoin; Tumor Cells, Cultured

Growth factor receptors of the tyrosine kinase family regulate proliferation of a variety of cell types. In some human cancers, the epidermal growth factor receptor (EGFR) and its ligands often are overexpressed, leading to both constitutive and autocrine activation. Intracellular signaling via this receptor takes place through several mechanisms of action, including activation of ras and the mitogen-activated protein kinase (MAPK) pathway. Our previous studies have shown that human squamous cell carcinoma (SCC) lines overexpress EGFR and do not increase proliferation in response to exogenous epidermal growth factor (EGF). The vitamin A metabolite retinoic acid (RA) has been used as a chemotherapeutic drug in the treatment of SCC. RA decreases proliferation of SCC lines, in part owing to inhibition of EGFR expression. However, we previously found that treatment of SCC lines with inhibitory doses of RA sensitized cells to the proliferative effects of EGF. We now present a mechanism of action for this effect. RA inhibited expression of EGFR and proteins in the MAPK signaling pathway. Expression of these molecules returned to basal levels within 24 h after RA withdrawal. RA also inhibited autocrine secretion of EGF, which returned to basal levels with slower kinetics. During this time, addition of exogenous EGF stimulated mitosis in SCC lines. These data suggested that signaling proteins downstream of overexpressed EGFR may have limited the mitotic response in SCC lines. In support of this hypothesis, overexpression of the EGFR adaptor protein Grb2 increased cell proliferation and restored EGF-induced mitosis.

Topics: Adaptor Proteins, Signal Transducing; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Division; Epidermal Growth Factor; ErbB Receptors; GRB2 Adaptor Protein; Humans; Proteins; Signal Transduction; Transfection; Tretinoin; Tumor Cells, Cultured

To study the induction of apoptosis by retinoid acid(RA) in Tca83 cell line and the expression of correlative Fas/FasL gene.. Apoptosis of Tca83 was detected by TUNEL, the expression of Fas/FasL-mRNA was detected by RT-PCR and cell immunohistochemical technique.. The cell apoptosis number of Tca83 in RA group was significantly higher than that in non-RA groupe on day 5(P < 0.05). The expression of Fas-mRNA in RA group was also much higher than that in non-RA group on day 5(P < 0.05), but the level of FasLmRNR had no change. Immunohistochemistry also showed, after RA treatment, the Fas stain was enhanced.. The result suggests that apoptosis induced by RA may be resulted from the enhancement of Fas gene transcription and translation.

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Fas Ligand Protein; fas Receptor; Gene Expression Regulation, Neoplastic; Humans; In Situ Nick-End Labeling; Membrane Glycoproteins; Reverse Transcriptase Polymerase Chain Reaction; Tongue Neoplasms; Tretinoin; Tumor Cells, Cultured

Human lung squamous carcinoma cell line(TUL cell) was treated with 5 x 10(-6) mol.L-1 all-trans retinoic acid(ATRA). Cell numbers were estimated by 0.4% trypon blue stain. MTT test was used for determining the percentage of cell growth inhibition(GI). DNA syntheses of cells were evaluated by 3H-thymidine incorporation. Cell ultrastructure was examined by transmission electron microscope(TEM). TUL cells were treated with or without ATRA, and transplanted in cutaneous of Balb/c nude mice. The results showed that: 1. The speed of cell growth in study group was smaller than that in control group. 2. The GI of cell lines TUL was 42.3%. 3. The percentage of 3H-thymidine incorporation of TUL cells was declined significantly. 4. Ultrastructure under TME showed that TUL cells treated with ATRA was suppressed. These results suggest that ATRA has the effects on growth-inhibition and differentiation-induction of TUL cell.

Topics: Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Differentiation; Cell Division; Humans; Lung Neoplasms; Mice; Mice, Nude; Neoplasm Transplantation; Tretinoin; Tumor Cells, Cultured

Retinoids have been shown to inhibit the growth of many human tumor cells including breast, ovarian and squamous cell carcinoma (SCC). While the exact mechanism of retinoid mediated growth suppression is not known, a role for the retinoic acid receptors (RARs) and retinoid X receptors (RXRs) has been established in both the breast and ovarian tumor cell models. We set out to determine if modulation of RAR/RXR function would alter the retinoid sensitivity of oral SCC cells. We found that the growth of SCC cells was significantly inhibited by treatment with either all-trans-retinoic acid (trans-RA) or the synthetic, conformationally restricted RARgamma selective retinoids MM11254 and MM11389. In order to demonstrate a role for RAR/RXR function in this process, stable oral SCC cell clones constitutively overexpressing the dominant negative mutant RARbeta2 (R269Q) were prepared and shown to exhibit reduced RAR/RXR transcriptional transactivation activity. We found that oral SCC cells exhibiting reduced RAR/RXR function became resistant to growth inhibition by all-trans-RA, MM11254 and MM11389. Likewise, treatment of oral SCC cells with the RARgamma antagonist MM11253 was found to block the ability of MM11254 and MM11389 to inhibit SCC cell growth. Thus, modulation of RAR function through the use of RAR-gamma selective agonists, an RAR-gamma selective antagonist or a pan-RAR dominant negative mutant significantly alters the growth inhibitory response of oral SCC cells to retinoids.

Topics: Arginine; Carcinoma, Squamous Cell; Cell Division; Gene Transfer Techniques; Glutamine; Growth Inhibitors; Humans; Mouth Neoplasms; Mutagenesis, Site-Directed; Receptors, Retinoic Acid; Retinoic Acid Receptor gamma; Retinoids; Tretinoin; Tumor Cells, Cultured

Retinoic acid (RA) has been shown to be effective in suppressing premalignant lesions and preventing second primary malignancies in patients cured of squamous cell carcinoma of the head and neck. However, the precise mechanisms of these effects are still uncertain. In the present study, we examined the effect of 9-cis-RA on the growth of six oral cancer cell lines (HSC-2, HSC-3, HSC-4, Ca9-22, Ho-1-N-1 and Ho-1-u-1). In addition, the relationship among growth and differentiation of tumor cells, RA responsiveness and the expression of nuclear retinoic acid receptors were also investigated. Among the six cell lines examined, five (HSC-2, HSC-3, HSC-4, Ca9-22 and Ho-1-u-1) displayed growth inhibition after treatment with 1x10(-6) M 9-cis-RA, while Ho-1-N-1 cells were resistant to 9-cis-RA. The expression level of RARbeta in 9-cis-RA resistant Ho-1-N-1 cells was very low in comparison with the sensitive cell lines. On the other hand, all of the six the cell lines expressed RARalpha, RARgamma, and RXRalpha at various levels. 9-cis-RA induced accumulation of cell population in G1 phase in HSC-3 cells on the 6th day of the treatment, followed by a marked reduction in the levels of hyperphosphorylated pRB, whereas p53 level was not altered. Interestingly, 9-cis-RA induced transiently the expression of p21(Waf1/Cip1), p27(Kip1), p300, CBP, BAX, Bak and bcl-2 proteins, respectively. This effect was associated with reduction of cyclin D1, cdk4 and CDK-activating kinase (cyclin H and cdk7) protein in HSC-3 cells. These results suggest that the growth inhibitory effect of 9-cis-RA on oral squamous cell carcinoma may depend on the expression levels of RARs, especially RARbeta proteins and RXRalpha proteins, and that 9-cis-RA may provide a powerful therapeutic agent for head and neck cancers.

Topics: Alitretinoin; Apoptosis; Carcinoma, Squamous Cell; Cell Cycle Proteins; Cell Differentiation; Cell Division; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; G1 Phase; Gene Expression Regulation, Neoplastic; Genes, cdc; Humans; Mouth Neoplasms; Receptors, Retinoic Acid; Retinoid X Receptors; RNA, Messenger; Transcription Factors; Tretinoin; Tumor Cells, Cultured

Retinoic acid receptor beta (RARbeta) is thought to be involved in suppressing cell growth and tumorigenicity. Many premalignant and malignant cells exhibit a reduced RARbeta expression. However, in some of these cells (e.g. H157 human squamous cell carcinoma cells), RARbeta can be induced by retinoids (e.g. all-trans-retinoic acid, ATRA) because its promoter contains a retinoic acid response element. To examine the hypothesis that RARbeta induction is important for inhibition of cell proliferation by retinoids, we blocked ATRA-induced RARbeta expression in H157 cells using a retroviral vector harboring multiple copies of antisense RARbeta2 sequences. Antisense RARbeta-transfected cells showed not only decreased expression of ATRA-induced RARbeta protein but also reduced ATRA-induced RARE binding activity and transactivation. Importantly, all antisense RARbeta transfectants of H157 cells were less responsive than vector-transfected cells to the growth inhibitory effects of the retinoids ATRA and Ch55 in vitro. These results demonstrate that RARbeta induction may play an important role in mediating growth inhibitory effects of retinoids in cancer cells.

Topics: Base Sequence; Carcinoma, Squamous Cell; Cell Division; DNA Primers; Humans; Lung Neoplasms; Oligonucleotides, Antisense; Receptors, Retinoic Acid; Transcriptional Activation; Transfection; Tretinoin; Tumor Cells, Cultured

Studies into the effects of topical retinoic acid on photocarcinogenesis have yielded ambiguous findings. This may be due to different Experimental protocols and ultraviolet spectra. Retinoic acid is commonly used for a range of dermatologic conditions, and therefore it is important to resolve whether it affects skin tumor formation. To address this issue we used a protocol to mimic as closely as possible human use of retinoic acid. Two mouse strains were used: Skh:HR-1 (albino) and Skh:HR-2 (lightly pigmented). The pigmented mice more closely resemble Caucasian skin as they develop a light tan in response to ultraviolet radiation. This tan is greatly augmented by retinoic acid. As these are congenic mice, any differences can be attributed to the development of a tan. Mice were exposed to solar-simulated ultraviolet radiation, followed by treatment with 0.05% retinoic acid. This modeled exposure to sunlight during the day followed by retinoic acid treatment and a night-time period in the absence of sunlight. As it is recommended that ultraviolet exposure is minimized when using topical retinoic acid, the mice were only exposed to one-third of minimal edemal dose of ultraviolet radiation per day. This retinoic acid protocol augmented photocarcinogenesis. Retinoic acid decreased the latency period, reduced the probability that a mouse would survive without a tumor, and increased the number of tumors per mouse. All tumors induced were squamous cell carcinomas, and the skin between the tumors on mice treated with retinoic acid was found to contain carcinoma in situ upon histologic diagnosis. The light tan of the solvent-treated pigmented mice did not provide any protection, whereas the dark tan, which developed in Skh:HR-2 mice in response to retinoic acid, reduced photocarcinogenesis but did not overcome the augmenting effect of retinoic acid. Thus, using this experimental design, topical retinoic acid augmented photocarcinogenesis, and the ability to develop a dark but not light tan provided some, but limited, protection.

Topics: Administration, Topical; Animals; Carcinoma, Squamous Cell; Female; Melanins; Melanoma; Mice; Pigmentation; Skin Neoplasms; Sunlight; Tretinoin; Ultraviolet Rays

Tumor neovascularization is necessary for the progressive development of all solid tumors, including head and neck squamous cell carcinomas (HNSCCs). The angiogenic process includes increased endothelial cell motility. Our prior studies have shown the importance of protein phosphatase-2A (PP-2A) in restricting endothelial cell motility. Because motility is regulated by the polymerization/depolymerization of the cellular cytoskeleton, the present study defined the interrelationship between PP-2A and the cytoskeleton during endothelial cell responses to HNSCC-derived angiogenic factors. PP-2A was shown to colocalize with microtubules of unstimulated endothelial cells. However, exposure to HNSCC-derived products resulted in a more diffuse distribution of PP-2A staining and a loss of filamentous tubulin. The feasibility of pharmacologically preventing this cytoskeletal disorganization as a means of blocking tumor-induced angiogenesis was tested. This was accomplished by use of 1alpha,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] and all-trans -retinoic acid to indirectly stimulate PP-2A activity through their capacity to elevated intracellular levels of the second messenger ceramide. Pretreatment of endothelial cells with either 1,25(OH)(2)D(3) or retinoic acid prevented the cytoskeletal disorganization that otherwise occurs in endothelial cells on exposure to HNSCC-derived products. These studies support the feasibility of using elevation of PP-2A to prevent the morphogenic component of the angiogenic process that is stimulated by HNSCC-derived factors.

Topics: Angiogenesis Inducing Agents; Blotting, Western; Calcitriol; Carcinoma, Squamous Cell; Cell Division; Cell Movement; Culture Media, Conditioned; Cytoskeleton; Endothelium, Vascular; Enzyme Activation; Head and Neck Neoplasms; Humans; Immunohistochemistry; Microtubules; Neovascularization, Pathologic; Phosphoprotein Phosphatases; Protein Phosphatase 2; Tretinoin; Tubulin; Tumor Cells, Cultured

In vitro monolayer culture and clonogenic assay were used to investigate the individual and combined effect of temperature and retinoic acid (RA) on cellular morphology and colony forming ability of human epidermoid laryngeal carcinoma (HEp-2) cells. 20 micromol. RA alone inhibited multilayer formation and induced cell flattening. Hyperthermia (42 degrees C) individually caused formation of cytoplasmic processes and irregularities in cellular shape and size. Combined effect of hyperthermia (42 degrees C) and 20 micromol. RA treatment caused bleb formation on cell surfaces and lysis of cytoplasmic and nuclear membrane. RA treatment also caused dose-dependent reduction of colony growth. Heat-induced cell killing was only observed at lethal temperatures of 43 degrees C and above. RA in combination with heat synergistically inhibited colony formation even at non lethal temperatures of 41 and 42 degrees C. These results indicate that RA in combination with hyperthermia may facilitate the therapy of human epidermoid larynx carcinoma.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Division; Cell Survival; Combined Modality Therapy; Dose-Response Relationship, Drug; Hot Temperature; Humans; Laryngeal Neoplasms; Tretinoin; Tumor Cells, Cultured

Retinoids are promising agents for the prevention and treatment of several human malignancies including lung cancer. In this study, the effect of retinoic acid (RA) on cell growth and the mechanism of growth modulation were examined in human lung squamous carcinoma CH27 cells. Here we report that RA mediated the dose- and time-dependent growth arrest in G1 phase, accompanied by the up-regulation of p27(Kip1) and the down-regulation of the cyclin-dependent kinase 3 (Cdk3) and p21(CIP1/Waf1) proteins. Furthermore, RA-induced growth arrest of CH27 cells was also associated with increased retinoic acid receptor beta (RARbeta) and reduced c-Myc expression. However, RA had no effect on the levels of cyclins A, D1, D3, E, or H, or on Cdk2, Cdk4, Cdk5, CDk6, Cdk7, p16(Ink4A), p15(Ink4B), p53, or pRb proteins in CH27 cells. Evaluation of the kinase activity of cyclin-Cdk complexes showed that RA increases p27(Kip1) expression in CH27 cells leading to markedly reduced cyclin A/Cdk2 kinase activity and slightly reduced cyclin E/Cdk2 kinase activity, with no effect on cyclin D/Cdk4 and cyclin D/Cdk6 activities. Moreover, coincident with the decrease in kinase activity was a drastic increase in cyclin A-bound p27(Kip1). These results suggest that increases in the levels of p27(Kip1) and its binding to cyclin A, as well as reduction of Cdk3 protein expression, are strong candidates for the cell cycle regulator that prevents the entry into the S phase in RA-treated CH27 cells, with prolongation of G1 phase and inhibition of DNA synthesis.

Topics: Carcinoma, Squamous Cell; CDC2-CDC28 Kinases; Cell Cycle; Cell Cycle Proteins; Cell Division; Chromatography, Gel; Cyclin A; Cyclin E; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase 3; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Cyclin-Dependent Kinases; Cyclins; G1 Phase; Humans; Lung Neoplasms; Microtubule-Associated Proteins; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins c-myc; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; Retinoic Acid Receptor gamma; Tretinoin; Tumor Cells, Cultured; Tumor Suppressor Proteins

The human keratinocyte line SCC-4 is a model system in which to explore the mechanism by which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) interferes with the action of hormones in the steroid receptor superfamily. In present work, retinoid induction of tissue transglutaminase mRNA was suppressed 60-70% by 10 nM TCDD in the human squamous carcinoma cell line SCC-4. This effect occurred without enhanced degradation of the mRNA and thus appeared to result from altered transcription. The actions of all-trans-retinoic acid and the synthetic retinoid TTNPB ((E)4-[2-(5,6,7,8-tetrahydro-5,5,8, 8-tetramethyl-2-naphthylenyl)-1propenyl] benzoic acid), which resists metabolic degradation, were suppressed to the same extent without obvious changes in their EC(50)s. In addition, TCDD suppression of reporter transcription, driven by a retinoic acid response element, was not evident in transient or stable transfections of SCC-4 cells. Sodium butyrate (3 mM) alone induced tissue transglutaminase and augmented retinoid induction. In the presence of butyrate, TCDD acted as an inducer and did not reduce retinoid stimulation. Retinoic acid induction of tissue transglutaminase displayed a lag phase of >24 h, indicating that the induction has an indirect component. Rather than depleting active retinoid in the culture medium or generally inactivating retinoid receptor function, TCDD may suppress retinoid action in this case by interfering with the late phase of induction.

Topics: Benzoates; Carcinoma, Squamous Cell; Humans; Keratinocytes; Polychlorinated Dibenzodioxins; Retinoids; RNA, Messenger; Transglutaminases; Tretinoin; Tumor Cells, Cultured

Type I Interferon (IFN) and all-trans retinoic acid (RA) inhibit cell proliferation of squamous carcinoma cell lines (SCC). Examinations of growth-affected cell populations show that SCC lines ME-180 and SiHa treated with IFN-beta undergo a specific slower progression through the S phase that seems to trigger cellular death. In combination treatment RA potentiates IFN-beta effect in SCC ME-180 but not in SiHa cell line, partially resistant to RA antiproliferative action. RA added as single agent affects cell proliferation differently by inducing a slight G1 accumulation. The IFN-beta-induced S phase lengthening parallels the increased expression of PML, a nuclear phosphoprotein specifically up-regulated at transcriptional level by IFN, whose overexpression induces cell growth inhibition and tumor suppression. We report that PML up-regulation may account for the alteration of cell cycle progression induced by IFN-beta in SCC by infecting cells with PML-PINCO recombinant retrovirus carrying the PML-3 cDNA under the control of the 5' LTR. In fact PML overexpression reproduces the IFN-beta-induced S phase lengthening. These findings provide important insight into the mechanism of tumor suppressing function of PML and could allow PML to be included in the pathways responsible for IFN-induced cell growth suppression.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Squamous Cell; Cell Division; DNA, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Growth Inhibitors; Humans; Interferon Type I; Neoplasm Proteins; Nuclear Proteins; Promyelocytic Leukemia Protein; Protein Isoforms; Recombinant Proteins; S Phase; Transcription Factors; Tretinoin; Tumor Cells, Cultured; Tumor Suppressor Proteins; Up-Regulation; Uterine Cervical Neoplasms

We recently demonstrated that the constitutive expression of cyclooxygenase (COX)-2 protein and prostaglandin E(2) (PGE(2)) biosynthesis were significantly enhanced in human skin epidermal cancer cells and that cancer cell growth was effectively inhibited by the suppression of COX-2 expression by transfection with COX-2 antisense oligonucleotide. The purpose of this study was to search for agents which suppress COX-2 expression and examine their effects on cell growth. Since retinoids and antioxidants have been used for chemoprevention of cancers in several tissues, the effects of these agents on COX-2 expression and PGE(2) biosynthesis in skin squamous carcinoma cells were investigated. Treatment with a retinoid (9-cis-retinoic acid (9-cis-RA)) or an antioxidant (pyrrolidinedithiocarbamate (PDTC)) suppressed COX-2 expression and PGE(2) biosynthesis in a concentration-dependent manner. Cell growth was significantly inhibited by 9-cis-RA and PDTC. These results suggest that 9-cis-RA and PDTC may be useful in preventing skin cancer growth and that COX-2 is involved in their protective effects on skin carcinogenesis.

Topics: Acetylcysteine; Alitretinoin; Antineoplastic Agents; Antioxidants; Blotting, Western; Carcinoma, Squamous Cell; Cell Division; Cell Line; Cyclooxygenase 2; Dinoprostone; Dose-Response Relationship, Drug; Free Radical Scavengers; Humans; Isoenzymes; Keratinocytes; Membrane Proteins; Oligonucleotides, Antisense; Prostaglandin-Endoperoxide Synthases; Pyrrolidines; Retinoids; Skin Neoplasms; Thiocarbamates; Time Factors; Transfection; Tretinoin; Tumor Cells, Cultured

To elucidate the chemosensitivity of human tongue squamous cell carcinoma Tca83 cell line to all-trans retinoid acid (RA) and to determine the potential genetic factors mediating this sensitivity.. RA in the amounts of 0.1, 1, and 10 microMol/L were used to treat human cell line Tca83 in vitro. Cell apoptosis as well as Fas/FasL expression were analyzed by TUNEL, RT-PCR, and immunohistochemistry approaches.. RA in the amounts of 1 and 10 microMol/L RA began to inhibit cell proliferation at day 3 and had induced cell apoptosis on day 5. Both Fas and FasL could be detected in the treated and untreated cells. RA upregulated Fas mRNA and protein expression at day 5. RA had no obvious effect on FasL expression.. The results suggest that apoptosis induced by RA may result from the enhancement of Fas gene transcription and translation.

Topics: Antigens, Surface; Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Cell Division; Cell Survival; Coloring Agents; Fas Ligand Protein; fas Receptor; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; In Situ Nick-End Labeling; Ligands; Membrane Glycoproteins; Protein Biosynthesis; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tetrazolium Salts; Thiazoles; Time Factors; Tongue Neoplasms; Transcription, Genetic; Tretinoin; Tumor Cells, Cultured; Up-Regulation

The uptake and metabolism of retinol was compared in squamous cell carcinoma lines, SCC12b and SCC13, and in normal human keratinocytes (NHK). Long chain fatty acid esters of retinol and 3,4-didehydroretinol were the predominant metabolites formed in both cell types. Lesser amounts of unesterified retinol, 3,4-didehydroretinol, and their respective active acid forms were also observed. Despite a qualitatively similar retinoid composition, there were significant quantitative differences between cell types. Most notable was that SCC formed only about one-fourth the retinoid ester as did normal cells. In parallel with this, unesterified retinol and retinoic acid concentrations in SCC were significantly elevated over those in normal cells. This altered pattern of retinoid metabolites in SCC was found to be due to very low lecithin:retinol acyltransferase (LRAT) activity. SCC exhibited less than one-tenth the LRAT activity of normal cells. Acyl-coenzyme A:retinol acyltransferase (ARAT) and retinyl ester hydrolase activities were not different between cell types. Challenging cells with increasing medium retinol concentrations resulted in dose-dependent increases in retinol and retinoic acid within SCC. In contrast, retinol and retinoic acid concentrations in similarly challenged normal cells remained relatively low across a wide retinol concentration range. This was accomplished by the storage of retinol, via LRAT activity, as retinyl ester. Consistent with increased substrate-driven retinoic acid synthesis in SCC, the expression of transglutaminase 1 was suppressed to a greater extent in the SCCs than in NHK, when cells were exposed to equivalent medium concentrations of retinol. The data demonstrate a central role of LRAT in regulating retinoic acid synthesis via its capacity to modulate cellular levels of substrate retinol.

Topics: Acyltransferases; Base Sequence; Carcinoma, Squamous Cell; Cell Line; DNA Primers; Gene Expression; Humans; Keratinocytes; Kinetics; Substrate Specificity; Transglutaminases; Tretinoin; Tumor Cells, Cultured; Vitamin A

We have evaluated the tumor tissue pO2 in cervical cancers during radiotherapy with special emphasis on the course of the pO2 in primarily hypoxic tumors and in patients treated with radiotherapy plus 13-cis-retinoic acid/interferon-alpha-2a.. From June 1995 through April 1997, 49 patients with squamous cell carcinoma FIGO IIB-IVA of the cervix who were treated with definitive radiotherapy with curative intent underwent polarographic measurement of tumor tissue pO2 with an Eppendorf pO2-histograph prior to and during radiation treatment. Radiotherapy consisted of external irradiation with 50.4 Gy in 28 fractions of 1.8 Gy plus high dose rate (HDR) brachytherapy. Twenty-two patients had additional treatment with 13-cis-retinoic acid (cRA, isotretinoin) and interferon-alpha-2a (IFN-alpha-2a). Therapy with cRA/IFN in these patients started 2 weeks before radiotherapy; during this induction period, cRA was administered in a dosage of 1 mg per kilogram body weight orally daily and IFN-alpha-2a in a dosage of 6x10(6) I.U. subcutaneously daily. After start of external radiotherapy (XRT), cRA/IFN was continued concomitantly with radiotherapy in reduced doses (0.5 mg cRA per kg body weight orally daily plus 3x10(6) I.U. IFN-alpha-2a subcutaneously three times weekly until the end of the radiation treatment). PO2 measurements were performed prior to radiotherapy, at 20 Gy, and at the end of radiotherapy.. A poor oxygenation defined as a median pO2 of 10 mm Hg or less was present in 15/38 tumors (39%) in which measurements prior to any treatment were done. Low pO2 readings below 5 mm Hg were present in 70% of all tumors prior to treatment. In 13 of 15 hypoxic tumors, pO2 measurements at 19.8 Gy were performed. In these tumors, a significant increase of the median pO2 from 6.0+/-3.1 mm Hg to 20.7+/-21.2 mm Hg was found, p<0.01. The increase in the median pO2 was more pronounced in patients with radiotherapy plus additional cRA/IFN treatment as compared to patients treated with irradiation alone (median pO2 raised from 7.0+/-3.5 mm Hg to 40.9+/-21.3 mm Hg versus 5.7+/-3.1 mm Hg to 14.7+/-17.9 mm Hg). In a multivariate analysis, both the effect of radiation dose (pretreatment versus 19.8 Gy) and the type of treatment (XRT alone versus XRT plus cRA/IFN) had significant impact on the pO2 (P = 0.003 and p = 0.04). In patients with well-oxygenated tumors (pretreatment median pO2>10 mm Hg), 20/23 (87%) achieved a clinically complete response. In patients with primarily hypoxic tumors, 6/6 patients whose primarily hypoxic tumors showed an increase of the median pO2 above 10 mm Hg at 19.8 Gy achieved a complete remission (CR). In contrast, only 4/7 patients with a low pretreatment and persisting low median pO2 achieved a CR.. There are evident changes in the oxygenation of cervical cancers during a course of fractionated radiotherapy. In primarily hypoxic tumors, a significant increase of the median pO2 was found. An additional treatment with cis-retinoic acid/interferon further improved the oxygenation. An impact of the different patterns of oxygenation on local control is to be evaluated.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Squamous Cell; Cell Hypoxia; Cisplatin; Combined Modality Therapy; Dose Fractionation, Radiation; Female; Humans; Interferon alpha-2; Interferon-alpha; Middle Aged; Oxygen; Partial Pressure; Recombinant Proteins; Tretinoin; Uterine Cervical Neoplasms

The purpose of our study was to analyze the independent and combined effects of RAR-, RXR-, and VDR-selective ligands on the growth of squamous cell carcinoma to develop new, more effective, and less toxic chemopreventive therapy.. The effects of 13-cis retinoic acid (13-cis RA), LG1069 (a highly selective RXR ligand), and vitamin D3 (D3) were analyzed in vitro in the SCC-25 human squamous cell carcinoma cell line. SCC-25 cells were grown in culture medium containing vehicle or hormone at the indicated concentrations. Growth of surviving cells was then assessed using a hemocytometer. The presence of functional vitamin D3 receptor (VDR) was confirmed using gene-transfer experiments with a promoter-lac Z reporter plasmid.. D3 and 13-cis RA have equipotent antiproliferative effects on SCC-25 cells. Furthermore, equimolar LG1069 completely blocks the growth-suppressive effects of D3 but has no effect on the action of 13-cis RA.. D3 and its analogs, administered alone or in combination with 13-cis RA, may provide more effective and less toxic chemopreventive therapy for the prevention of second primary carcinomas of the head and neck.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Division; Cholecalciferol; DNA-Binding Proteins; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Drug Therapy, Combination; Humans; Receptors, Calcitriol; Receptors, Retinoic Acid; Retinoid X Receptors; Transcription Factors; Tretinoin; Tumor Cells, Cultured

The preventive effects of retinoids on oral carcinogenesis may be related to their ability to modulate the growth and differentiation of human oral squamous epithelial cells. Nuclear retinoid receptors (RAR alpha, beta, and gamma, and RXR alpha, beta, and gamma) may mediate these effects by regulating gene transcription. The removal of serum from the growth medium of two head and neck squamous cell carcinoma lines 1483 and SqCC/Y1 resulted in a decrease in RAR beta mRNA level and concurrent increases in the expression of the keratin K1 and transglutaminase type I (TGase I), which are markers of differentiation of keratinizing squamous epithelial cells. All-trans-retinoic acid (tRA) or 13-cis-RA increased RAR beta and decreased K1 and TGase I mRNA levels in serum-free medium. Transcriptional activation of reporter genes by means of retinoid response elements (RARE and RXRE) indicated that the RXR-RAR pathway predominates over the RXR homodimer pathway in the 1483 cells. Among several synthetic retinoids with preference for binding to specific nuclear retinoid receptors, those that induced RAR beta also suppressed K1. The inverse association between RAR beta expression and K1 and TGase I levels implicates this receptor in suppression of keratinization in oral epithelial cells.

Topics: Biomarkers, Tumor; Carcinoma, Squamous Cell; Cell Differentiation; Cell Division; Collagenases; Dose-Response Relationship, Drug; Gene Expression Regulation, Neoplastic; Head and Neck Neoplasms; Humans; Keratins; Promoter Regions, Genetic; Receptors, Retinoic Acid; Response Elements; Retinoid X Receptors; Retinoids; Transcription Factor AP-1; Transcription Factors; Transcription, Genetic; Transcriptional Activation; Tretinoin; Tumor Cells, Cultured

Interferon regulatory factor 1 (IRF-1) transcription factor binds to DNA sequence elements found in the promoters of type I IFN and IFN-inducible genes. Transient up-regulation of the IRF-1 gene by virus and IFN treatment causes the consequent induction of many IFN-inducible genes involved in cell growth control and apoptosis. We reported recently that IFN-alpha and all-trans retinoic Acid (RA) inhibit the cell proliferation of squamous carcinoma cell line ME-180 by inducing apoptotic cell death. IRF-1 expression correlates with the IFN-alpha-induced apoptosis phenomenon and, surprisingly, with the RA-induced apoptosis phenomenon. To study how these two different ligands cross-talk in the regulation of cellular antitumor responses, the signalling pathways involved in IRF-1 induction were analyzed in RA and/or IFN-alpha-treated ME-180 cells. We provide evidence indicating that RA-induced IRF-1 gene expression is independent of the STAT-1 activation pathway, despite the presence of the IFN-gamma activated sequence element in the gene promoter, but involves nuclear factor-kappaB activation. Thus, here we first describe the activation of nuclear factor-kappaB by both IFN-alpha and RA in the ME-180 cell line. The induced IRF-1 protein is successively able to bind the IFN-stimulated responsive element in the promoter of the target gene 2',5'-oligoadenylate synthetase.

Topics: Carcinoma, Squamous Cell; Dactinomycin; DNA Primers; DNA-Binding Proteins; Electrophoresis, Polyacrylamide Gel; Gene Expression Regulation; Humans; Immunoblotting; Interferon alpha-2; Interferon Regulatory Factor-1; Interferon-alpha; NF-kappa B; Phosphoproteins; Protein Synthesis Inhibitors; Recombinant Proteins; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Skin Neoplasms; STAT1 Transcription Factor; Time Factors; Trans-Activators; Transfection; Tretinoin; Tumor Cells, Cultured

The effect of photothermal vascular targeting, alone and in combination with antiangiogenic therapy, was evaluated using tumors produced in mice by transplantation of KB cells. Tumor growth inhibition and regression followed vascular damage produced by pulsed dye laser (PDL) radiation. Administration of the antiangiogenic agent all-trans-retinoic acid (RA) was associated with smaller average tumor volumes in the presence and absence of PDL irradiation, but this effect was not statistically significant. The ability of PDL photothermal vascular targeting to cause regression of tumors without harming normal tissue may be a consequence of preferential damage to supplying vessels at the tumor periphery.

Topics: Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Combined Modality Therapy; Humans; Laser Coagulation; Mice; Mice, Nude; Neovascularization, Pathologic; Tretinoin; Tumor Cells, Cultured

Nuclear retinoic acid receptor beta(RARbeta) expression is suppressed in many head and neck squamous cell carcinomas (HNSCCs), and an inverse relationship was found between squamous differentiation and RARbeta expression in such cells. To investigate the role of RARbeta in HNSCC growth and differentiation, we transfected a retroviral RARbeta2 expression vector (LNSbeta) into HNSCC SqCC/Y1 cells, which do not express endogenous RARbeta but do express RARalpha, RARgamma, and retinoid X receptors. Transfected clones expressing RARbeta2 mRNA and protein exhibited enhanced sensitivity to the suppressive effects of all-trans-retinoic acid (ATRA) on squamous differentiation compared with cells transfected with the LNSX vector only; transglutaminase type I level was suppressed after a 3-day treatment with 10(-10) M ATRA in four of five LNSbeta clones, whereas it was not suppressed in LNSX cells even by 10(-6) M ATRA. Similarly, cytokeratin 1 mRNA level was more suppressed in ATRA-treated LNSbeta clones than it was in LNSX cells. This effect was independent of transrepression of activator protein-1. None of the LNSbeta-transfected clones showed an increased growth inhibition by ATRA, 9-cis-retinoic acid, or the synthetic retinoid 6-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-2-naphthale necarboxylic acid. These findings suggest that, in SqCC/Y1 cells, RARbeta mediates suppression of squamous differentiation by ATRA without enhancing its growth-inhibitory effects.

Topics: 3T3 Cells; Alitretinoin; Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Differentiation; Drug Resistance; Head and Neck Neoplasms; Humans; Mice; Naphthalenes; Neoplasm Proteins; Receptors, Retinoic Acid; Retinoids; RNA, Messenger; RNA, Neoplasm; Transcription Factor AP-1; Transfection; Tretinoin; Tumor Cells, Cultured

To develop a more effective induced-differentiation or -apoptosis therapy for treating oral squamous cell carcinomas.. The combination of all trans retinoic acid (ATRA) and interferon-gamma (IFN-gamma) was tested for its antiproliferative activity against human tongue squamous cell carcinoma cell line (Tca8113 cells) in vitro. Clonogenic assay, MTT assay, and microscopic cell analysis were performed in this experiment.. The results show that the combination of ATRA and IFN-gamma can produce synergistic antitumor effects, resulting from induction of apoptosis, on Tca8113 cells.. The combination of ATRA and IFN-gamma is a more effective induced-apoptosis therapy for treating oral squamous cell carcinoma.

Topics: Apoptosis; Carcinoma, Squamous Cell; Cell Division; Dose-Response Relationship, Drug; Drug Synergism; Humans; Interferon-gamma; Time Factors; Tongue Neoplasms; Tretinoin; Tumor Cells, Cultured

Retinoids and interferon-alpha (IFN-alpha) have been shown to exert antiproliferative and radiosensitizing effects. The present study was designed to determine differential effects of retinoids in combination with IFN-alpha on radiation toxicity of 5 human squamous cell carcinoma (SCC) cell lines.. Using clonogenic assays, the effects of all-trans (ATRA), 13-cis-retinoic acid (13cRA), and IFN-alpha on radiation toxicity were analyzed. Basal mRNA expression of the cytoplasmic retinoic acid binding protein, CRABP I, was determined in retinoid-sensitive and -insensitive cell lines by reverse transcriptase/polymerase chain reaction (RT-PCR).. Treatment with ATRA, 13cRA, or IFN-alpha resulted in a cell line-specific inhibition of clonogenic survival. A comparison of retinoid-sensitive and insensitive cells revealed that retinoid sensitivity seems to be dependent on the basal expression level of CRABP I. ATRA, 13cRA, and IFN-alpha alone or in combination altered radiation sensitivity by affecting predominantly the alpha-component of the linear-quadratic dose-response curve. Likewise, depending upon the treatment condition the surviving fraction at 2 Gy (SF2) was decreased cell line-specifically. Combined treatment with ATRA or 13cRA and IFN-alpha markedly enhanced radiation cytotoxicity.. These in vitro data indicate that the combined treatment with retinoids, IFN-alpha, and ionizing radiation could be beneficial for patients presenting with SCC.

Topics: Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Squamous Cell; Combined Modality Therapy; Dose Fractionation, Radiation; Dose-Response Relationship, Radiation; Humans; Interferon-alpha; Isotretinoin; Neoplasm Proteins; Radiation Tolerance; Radiation-Sensitizing Agents; Receptors, Retinoic Acid; Tretinoin; Tumor Cells, Cultured

All-trans-retinoic acid (ATRA) and interferons (IFNs) have been proven to synergistically amplify growth inhibition and apoptosis in the tongue squamous carcinoma cell line (Tca8113). Nuclear retinoic acid receptor-beta (RAR beta) was the key gene that mediated retinoid activity for squamous carcinoma cells. In order to understand the mechanism of ATRA combined with IFN gamma inhibiting growth of Tca8113 cells, this investigation focused on RAR beta mRNA expression.. In this experiment, RT-PCR method was used to analyze the RAR beta expression level, and viable cell count assay was carried out for growth inhibition studies.. All-trans-retinoic acid (1 microM) and IFN gamma (1000 u/mL) inhibited cell growth by 39.2% and 44.4%, respectively. Synergistic inhibition of cell proliferation by 86.7% was found under combined treatment. The combination of suboptimal concentrations of ATRA (0.1 microM) with IFN gamma (1000 u/mL) showed a much stronger additive inhibitory effect on cell proliferation. ATRA (1 microM) and IFN gamma (1000 u/mL) increased RAR beta expression to 4 times and 3 times, respectively. The expression of RAR beta increased 12 times after treatment with combined ATRA and IFN gamma treatment.. These observations indicated that the use of combined ATRA and IFN may lead to enhanced antitumor effects. These results also suggested that ATRA and IFN mediated upregulating expression of RAR beta may play an important role in synergistic inhibition of proliferation in Tca8113 cells.

Topics: Carcinoma, Squamous Cell; Cell Division; Drug Synergism; Gene Expression; Humans; Interferon-gamma; Polymerase Chain Reaction; Receptors, Retinoic Acid; RNA, Messenger; Tongue Neoplasms; Tretinoin; Tumor Cells, Cultured; Up-Regulation

To study the inhibitory effects of 8-methoxypsoralen (8-MOP) combining with all trans retinoic acid (RA) on tongue cancer cell line Tca8113 and gingiva cancer cell line Ca9-22, MTT assay (tetrazolium-based colormetric assay) was applied and the changes in morphology were observed with the inverted microscope. The results showed that with 30% growth inhibition of the cell lines, the Combination Indexes (CI30) of the two drugs were no more than 0.82, and with 50% growth inhibition, the Combination Index (CI50) were from 0.9 to 0.95, which indicated synergic combination effects of the two drugs against the two oral squamous cancer cell lines. Apoptosis-body-like structures were observed in the cells treated with RA, 8-MOP, or the combination of RA with 8-MOP. Whether combination of the two drugs at appropriate concentrations has clinical value needs to be investigated.

Topics: Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Squamous Cell; Cell Division; Cell Line, Tumor; Humans; Methoxsalen; Tongue Neoplasms; Tretinoin

Retinoids, metabolites and synthetic derivatives of vitamin A (retinol), have been shown to inhibit carcinogenesis in various epithelial tissues in animal model systems and to have clinical efficacy as chemotherapeutic agents against certain types of cancer, including squamous cell carcinomas (SCCs). We examined the metabolism of [3H]retinol in normal human cell strains and SCC lines from the oral cavity and skin, and we report here that the cultured normal human epithelial cell strains esterified [3H]retinol to a much greater extent than the SCC lines. Furthermore, microsomal extracts of normal cell strains (e.g., OKF4) exhibited about 7-fold more palmityl-CoA-dependent, phenylmethylsulfonyl fluoride-resistant retinol esterification activity than extracts from SCC lines (e.g., SCC25). The fact that the esteriflcation of retinol was phenylmethylsulfonyl fluoride resistant suggests that the enzyme acyl-CoA:retinol acyltransferase is involved. Culture of both the normal and SCC lines in the presence of 1 microM all-trans-retinoic acid (RA) for 48 h enhanced the formation of [3H]retinyl esters from [3H]retinol. All of the cell lines examined can also metabolize [3H]retinol to [3H]RA, [3H]14-hydroxy-4,14-retroretinol, [3H]retinaldehyde, and [3H]3,4-didehydroretinol, but this metabolism occurs to varying extents in different cell lines. Culture of the cells in the presence of RA for 48 h did not affect the subsequent metabolism of [3H]retinol to [3H]RA and [3H]14-hydroxy-4,14-retroretinol, but it did reduce the metabolism of [3H]retinol to [3H]3,4-didehydroretinol. When cultured for 6-10 h in the presence of nanomolar concentrations of exogenous [3H]retinol, both the normal and SCC lines had much higher intracellular [3H]retinol concentrations, in the micromolar range. No correlation was seen between CRABP II or CRBP I mRNA levels and the levels of either intracellular [3H]retinol or [3H]retinol metabolism in these lines. The reduced ability to esterify retinol in these tumor cells may result in inappropriate cell growth and the loss of normal differentiation responses because of the lack of a sufficient amount of internal retinol stored as retinyl esters.

Topics: Carcinoma, Squamous Cell; Humans; Mouth Neoplasms; Skin Neoplasms; Tretinoin; Tumor Cells, Cultured

Products of arachidonic acid metabolism can influence normal and malignant cell growth. In vivo, inhibitors of arachidonic acid metabolism have been associated with inhibition of tumor growth, including head and neck squamous cell carcinoma (HNSCC). This has not been evaluated extensively in vitro in an HNSCC model. Therefore we investigated the effects of several arachidonic acid cascade inhibitors (AACIs) (indomethacin, curcumin, phenidone, nordihydroguaiaretic acid, 5,8,11,14-eicosatetraynoic acid, and 13-cisretinoic acid) on the growth of two HNSCC cell lines (MDA 886Ln and 1483). We found that AACIs caused dose-dependent growth inhibition of both cell lines. In an effort to inhibit HNSCC cell growth at lower concentrations of these drugs, we evaluated the effects of a variety of AACIs in combination with 13-cis retinoic acid. We observed synergistic growth inhibition when the drugs were used in all combinations, with the exception of indomethacin. These results suggest that AACIs may have some utility in the direct treatment of HNSCC, and a strategy combining 13-cis retinoic acid with other AACIs may prove to be even more effective.

Topics: Arachidonic Acid; Carcinoma, Squamous Cell; Cell Division; Cyclooxygenase Inhibitors; Drug Synergism; Head and Neck Neoplasms; Humans; Immunoenzyme Techniques; Prostaglandins E; Tretinoin; Tumor Cells, Cultured

We investigated the effects of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and 9-cis-retinoic acid (9cRA) on parathyroid hormone-related protein (PTHrP) production and its mRNA expression by the human oral squamous carcinoma cell line (HSC-3). The major transcript of PTHrP was 1.5 kb in human HSC-3 cells. In the presence and absence of serum, 1,25(OH)2D3 produced dose-dependent inhibition of PTHrP gene expression and secretion. Significant inhibition by 1,25(OH)2D3 in the presence of serum was observed at 10(-10) M for mRNA expression and 10(-8) M for secretion, whereas under serum-free conditions, 1,25(OH)2D3 significantly suppressed PTHrP mRNA expression at 10(-10) M and secretion at 10(-9) M. Thus the remainder of the experiments were performed under serum-free conditions. After 24 h of incubation, 9cRA decreased dose-dependently PTHrP mRNA expression and PTHrP secretion. Addition of 10(-7) M 1,25(OH)2D3 or 10(-7) M 9cRA to HSC-3 cells significantly suppressed PTHrp transcription within 1 h and the PTHrP secretion within 12 h. Maximal suppression of mRNA expression was maintained for 12-48 h. 9cRA caused a continuous decrease in PTHrP secretion for up to 48 h, whereas the inhibition of secretion by 1,25(OH)2D3 was transient and abolished by 48 h. Neither 1,25(OH)2D3 nor 9cRA altered the stability of PTHrP mRNA. The inhibitory effect of 1,25(OH)2D3 and 9cRA on PTHrP mRNA expression was additive, whereas no additive effect was observed with regard to PTHrP secretion. These results indicate that 1,25(OH)2D3 and 9cRA suppressed PTHrP production and mRNA expression in oral squamous cancer cells, and suggest that transcriptional suppression may act through binding of the heterodimer (vitamin D receptor-retinoid X receptor) to negatively responsive elements of the PTHrP gene.

Topics: Analysis of Variance; Calcitriol; Carcinoma, Squamous Cell; Depression, Chemical; Dose-Response Relationship, Drug; Gene Expression; Humans; Mouth Neoplasms; Parathyroid Hormone-Related Protein; Polymerase Chain Reaction; Protein Biosynthesis; Proteins; Radioimmunoassay; RNA, Messenger; Tretinoin; Tumor Cells, Cultured

Several lines of evidence have demonstrated that IFNs could be relevant in the treatment of certain neoplastic diseases such as carcinomas. In particular, IFN-alpha, in addition to the anti-proliferative and cytostatic effects, was demonstrated to be capable of inducing cell death by apoptosis both in vivo and in vitro. Numerous protocols have also been proposed which consider the association of IFN-alpha with other drugs. Among these are retinoids, a class of compounds capable of inducing inhibition of cell growth and differentiation. We address the question here by analyzing the role of cell adhesion in susceptibility to IFN-alpha, RA and their combination of a human cell line derived from a squamous carcinoma of the cervix, the Bcl-2-negative SiHa cell line. In this context, cytoskeleton components and several surface molecules playing a role in cell substrate and cell-to-cell relationships have been evaluated. We found that RA treatment is capable of improving stress fiber formation, decreasing cell detachment and increasing cell-adhesion capability. However, no variations in the ability to adhere to specific extracellular-matrix molecules were found in RA-treated cells. No quantitative changes were detected in integrins involved as receptors for extracellular matrix molecules (VLAI-VLA5) or in other cell-adhesion-associated molecules (e.g., CD44). By contrast, 2 important molecules involved in cell-adhesion processes appeared to be up-regulated by RA exposure: focal adhesion kinase and E-cadherin, involved in adhesion plaque formation and cell-to-cell contacts, respectively. Keeping in mind the importance of adhesion properties in the cell-growth pathway, our findings could be of interest in the study of carcinoma-cell proliferation and metastatic potential.

Topics: Cadherins; Carcinoma, Squamous Cell; Cell Adhesion; Cell Adhesion Molecules; Cell Division; Female; Focal Adhesion Kinase 1; Focal Adhesion Protein-Tyrosine Kinases; Humans; Interferon-alpha; Protein-Tyrosine Kinases; Proto-Oncogene Proteins c-bcl-2; Tretinoin; Tumor Cells, Cultured; Uterine Cervical Neoplasms

Mutations in receptors for the vitamin A metabolite retinoic acid (RAR) that repress retinoic acid (RA)-responsive gene expression have been identified and characterized. We previously reported an absence of target gene response to RA in all but one of a series of transformed human epithelial cell lines. To elucidate the mechanisms of this unresponsiveness, we created stable transfectants that expressed an RARalpha mutant (RARalpha403) previously shown to have dominant negative activity due to a C-terminal truncation. All clones exhibited repressed RA-responsive gene expression. These cells grew slowly and demonstrated greater growth inhibition by RA. Pretreatment of both control and experimental groups with RA enhanced epidermal growth factor-induced proliferation despite RA-dependent downregulation of epidermal growth factor receptor expression. In addition, clones expressing the mutant RARalpha were 60% less invasive in an in vitro assay. This reduced invasiveness correlated with decreased gelatinase activity in these cells. We showed for the first time that a dominant negative mutation in RARalpha can function as a tumor suppressor in transformed epithelial cells.

Topics: Carcinoma, Squamous Cell; Cell Division; Clone Cells; Epidermal Growth Factor; Humans; Neoplasm Invasiveness; Receptors, Retinoic Acid; Recombinant Proteins; Retinoic Acid Receptor alpha; Sequence Deletion; Transfection; Tretinoin; Tumor Cells, Cultured

All-trans retinoic acid (RA) can be catabolized into polar metabolites by cytochrome P450 (P450) in several tissues including the skin. We examined eight different squamous cell carcinoma (SCC) cell lines to determine their capacity to induce P450-mediated oxidation of RA. Among the eight different cell lines, enhanced catabolism was detected in AMC-HN-1, -2, -5, and -6, whereas it was not found in the cell lines of AMC-HN-3, -4, -7, and -8. It was found that the enhanced catabolism brought on by P450 induction was blocked when RA was added to AMC-HN-6 along with actinomycin D or cyclohexamide. Also, this catabolism was inhibited by ketoconazole. P450-mediated oxidation was detectable within 4 hours of RA treatment, and RA catabolism reached its maximum 16 hours after treatment. P450 was induced by 13-cis-RA, 9-cis-RA, and retinal; however, retinol could not induce P450. In conclusion, P450 can be induced by retinoids in head and neck SCC (HNSCC) cells and the ability of retinoids to induce P450 can serve as an important factor in determining the biological effect of retinoids.

Topics: Antibiotics, Antineoplastic; Antifungal Agents; Antineoplastic Agents; Carcinoma, Squamous Cell; Cycloheximide; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Dactinomycin; Enzyme Induction; Head and Neck Neoplasms; Humans; Ketoconazole; Oxidation-Reduction; Protein Synthesis Inhibitors; Retinoids; Tretinoin; Tumor Cells, Cultured

Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy in which multiple independent lesions develop over time throughout the mucosa of the upper aerodigestive tract. Therefore, the comprehensive treatment of this neoplasm must include a chemopreventive arm to hold premalignant lesions in check, a role well-suited to antiangiogenic agents. Retinoic acid (RA) and interferon alpha (IFN-alpha), drugs with known biological activity against HNSCC when used individually, are also inhibitors of angiogenesis. Here we show that they are remarkably synergistic antiangiogenic agents able to inhibit both the growth and the neovascularization of HNSCC injected into the floor of the mouth of nude mice. The mechanism of action of these drugs as antiangiogenic agents was 2-fold. They decreased the angiogenic activity of the tumor cells, and they caused the endothelial cells to become refractory to inducers of angiogenesis. When tumor cells were treated in vitro with IFN-alpha A/D, there was a dramatic drop in their secretion of interleukin-8, the major angiogenic factor produced by these tumors. When combined with RA, which causes tumor cells to secrete an inhibitor of angiogenesis, there was a synergistic inhibition of both tumor cell growth and secreted angiogenic activity. The combination of RA and IFN-alpha also acted synergistically on endothelial cells by reducing their responsiveness to both interleukin-8 and tumor conditioned media. Doses of each drug could be reduced by two logs without loss of activity. When animals bearing human HNSCC tumor cells were treated systemically with a combination of RA and IFN-alpha A/D at doses that were ineffective when used alone, dramatic decreases in both tumor growth and tumor angiogenesis were seen. These data suggest that the use of antiangiogenic mixtures may be a particularly effective way to design future chemoprevention protocols against HNSCC.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Squamous Cell; Cattle; Cell Division; Cells, Cultured; Chemoprevention; Drug Synergism; Endothelium, Vascular; Female; Head and Neck Neoplasms; Humans; Interferon Type I; Mice; Mice, Nude; Neovascularization, Pathologic; Rats; Rats, Inbred F344; Recombinant Proteins; Tretinoin; Tumor Cells, Cultured

The effects of retinoids such as all-trans-retinoic acid (ATRA) on cell growth, differentiation, and apoptosis are thought to be mediated by nuclear retinoid receptors, which are involved in ligand-dependent transcriptional activation of target genes. Using differential display, we identified the cDNA of a novel gene, designated retinoic acid-inducible gene 1 (RAIG1), which was induced by ATRA in the squamous carcinoma cell line UMSCC-22B. Two RAIG1 transcripts of 2.4 and 6.8 kilobase pairs, respectively, have the same ORF that encodes a 357-amino acid polypeptide. RAIG1 mRNA is expressed at high level in fetal and adult lung tissues. Induction of RAIG1 expression by ATRA is rapid (within 2 h) and dose-dependent in the range between 1 nM to 1 microM. The constitutive RAIG1 mRNA levels, which were low in three of five head and neck and four of six lung cancer cell lines, increased after ATRA treatment in most cell lines. The deduced RAIG1 protein sequence contains seven transmembrane domains, characteristic of G protein-coupled receptors. A fusion protein of RAIG1 and the green fluorescent protein was localized in the cell surface membrane and perinuclear vesicles in transiently transfected cells. RAIG1 was mapped to chromosome 12p12. 3-p13. Our results provide novel evidence for a possible interaction between retinoid and G protein signaling pathways.

Topics: Amino Acid Sequence; Base Sequence; Carcinoma, Squamous Cell; Cell Compartmentation; Cloning, Molecular; DNA, Complementary; Gene Expression Regulation; GTP-Binding Proteins; Head and Neck Neoplasms; Humans; Lung Neoplasms; Molecular Sequence Data; Multigene Family; Neoplasm Proteins; Receptors, Cell Surface; Receptors, G-Protein-Coupled; RNA, Messenger; Sequence Analysis, DNA; Signal Transduction; Tretinoin; Tumor Cells, Cultured

Recent studies have revealed promising leads on the potential of interferons (IFNs) in combination with retinoids in solid tumor therapy. The role of IFN-alpha and retinoic acid (RA) in cervical cancer is currently under active study. Because preclinical and clinical data on IFN-beta in combination with retinoids show promising results against breast carcinoma, we analysed the anti-proliferative effect of human recombinant IFN-beta alone or in combination with all-trans RA on two human squamous cervical carcinoma cell (SCC) lines (ME180 and SiHa). The two cell lines differ in their sensitivity to the anti-proliferative effects of the different agents and their combination: i) both cell lines were more responsive to IFN-beta than to IFN-alpha2b; ii) combined treatment with RA increases the growth inhibitory effect of the single agents in ME180, but not in SiHa; iii) the antiproliferative effect correlates with the induction of apoptosis. We suggest as a possible mechanisms of action that interferon regulatory factor-1 (IRF-1), a transcription factor which belongs to the IFN machinery, and the cyclin-dependent kinase inhibitor (CDKi) p21 can be involved in cellular growth inhibition and in the induction of apoptosis. These results support the use of IFN-beta in further clinical investigation possibly in combination with retinoids.

Topics: 2',5'-Oligoadenylate Synthetase; Apoptosis; Carcinoma, Squamous Cell; Cell Division; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinases; Cyclins; DNA Fragmentation; DNA-Binding Proteins; Drug Therapy, Combination; Enzyme Inhibitors; Female; Gene Expression; Humans; Interferon alpha-2; Interferon Regulatory Factor-1; Interferon-alpha; Interferon-beta; Phosphoproteins; Recombinant Proteins; RNA, Messenger; Tretinoin; Tumor Cells, Cultured; Uterine Cervical Neoplasms

Since acne is a multifactorial skin disease, therapies affecting several etiologic factors can have a higher than expected effectiveness. A combination of the antibiotic clindamycin phosphate and the retinoic acid tretinoin was developed.. Anti-inflammatory and immunomodulatory effects of tretinoin in vitro were studied on human keratinocytes and peripheral blood mononuclear cells (PBMCs). Effects of clindamycin phosphate on tretinoin effects were studied.. Anti-inflammatory effects on keratinocytes were assessed using an in vitro model with PMA (phorbol ester)-stimulated A431 cells (human epidermoid carcinoma). Immunomodulatory effects were measured on superantigen (SEB) stimulated PBMCs.. Tretinoin showed very potent inhibition of PMA-stimulated IL-6 (interleukin 6) release by A431 cells. The addition of clindamycin phosphate did not interfere with this effect. Tretinoin very potently stimulated IL-5 release, and inhibited IFN gamma release by SEB-stimulated human PBMCs. This indicates an immunomodulatory effect, stimulating Th2, and inhibiting Th1 dominated responses. These features have been related to the healing of acne lesions. The addition of clindamycin phosphate did not interfere with the immunomodulatory effects of tretinoin.. The combination of tretinoin and clindamycin phosphate can be expected to be very effective in acne therapy.

Topics: Acne Vulgaris; Adjuvants, Immunologic; Anti-Bacterial Agents; Anti-Inflammatory Agents; Carcinogens; Carcinoma, Squamous Cell; Clindamycin; Humans; Interferon-gamma; Interleukin-5; Interleukin-6; Keratinocytes; Keratolytic Agents; Lymphocytes; Monocytes; Superantigens; Tetradecanoylphorbol Acetate; Th1 Cells; Th2 Cells; Tretinoin

The fact that treatment of leukemia (Acute Promyelocytic Leukemia) with ATRA (All-Trans Retinoic Acid) was so succeeded that it was considered as a good example for tumor therapy. In the treatment of solid tumors by means of induced differentiation, however, has not been yet so broken-through. DMSO (Dimethylsulfoxide) was a common and simple organic compound, which comprised a variety of biological activities. For example, DMSO induced differentiation of leukemia in many reports. However, the effect of DMSO on solid tumors was to be explored further. In the present study, DMSO was used to human esophageal cancer cell lines in vitro in comparison with the classical inducer ATRA. From the view of morphology, cell cycle, growth inhibition, cytokeratin 4 expression, dye transfer and tumorigenecity, the results demonstrated that DMSO as well as ATRA could induce differentiation of human esophageal cancer cells. Interestingly, DMSO was confirmed to be more effective in inducing differentiation of esophageal cancer cells than ATRA. It suggests that DMSO showed some good prospects for the treatment of solid tumors.

Topics: Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Dimethyl Sulfoxide; Esophageal Neoplasms; Humans; Tretinoin; Tumor Cells, Cultured

Both retinoids and IFNs are known to inhibit proliferation of many normal and transformed cells and to have an in vivo antitumor effect against a variety of cancers, including squamous cell carcinoma. Because the combination of IFNs and all-trans retinoic acid (RA) could improve their antitumor effectiveness (depending on the histological origin and state of differentiation of the cells), we compared the activity of RA and/or IFN-alpha 2b with regard to the mechanism of growth inhibition of ME180 and SiHa cell lines, derived from squamous cervix carcinoma at different stages of differentiation. We reported previously that, in the ME180 cell line, the combined treatment significantly increased the growth inhibitory effect of the single agents. Here, we show that the SiHa cell line appears more sensitive to IFN-alpha 2b than the ME180 cell line, and resistant to RA, which does not significantly inhibit SiHa cell growth. Induction of apoptotic cell death clearly occurs and correlates with the inhibition of cell proliferation in both cell lines. It is interesting that the induction of the transcription factor IFN regulatory factor 1 correlates with the subsequent induction of apoptosis, whereas TGase I and II expression does not. In particular, TGase I and II appear differentially expressed in the ME180 and SiHa cell lines; i.e., TGase I is expressed in ME180 and specifically inhibited by RA, whereas TGase II is expressed in SiHa. It is interesting that both IFN-alpha and RA are able to increase TGase II expression and activity in this cell line.

Topics: Apoptosis; Carcinoma, Squamous Cell; Cell Division; DNA Fragmentation; DNA-Binding Proteins; Gene Expression Regulation; GTP Phosphohydrolases; GTP-Binding Proteins; Humans; Interferon alpha-2; Interferon Regulatory Factor-1; Interferon-alpha; Phosphoproteins; Protein Glutamine gamma Glutamyltransferase 2; Recombinant Proteins; Transglutaminases; Tretinoin; Tumor Cells, Cultured

To understand the role of retinoids in chemoprevention, the authors examined the effects of 13-cis retinoic acid (cRA) on squamous cell carcinoma proliferation and adhesion to extracellular matrix proteins. The antiproliferative effects of cRA were first seen on day 11 (66% inhibition) and progressed through day 19 (96% inhibition). Using an adhesion assay, the authors then investigated the effects of cRA and transforming growth factor-beta1 (TGF-beta1) on cellular adhesion to purified type IV collagen, fibronectin, and laminin matrices. Cells treated for 4 days with TGF-beta1 increased adhesion by 15% to 29%, and cells treated with cRA increased adhesion by 19% to 39%. However, the use of cRA alone resulted in a decrease in adhesion when tumor cells were treated for 7 days (20% to 32%) and 15 days (25% to 40%). The authors also discuss how cRA acts as a differentiating agent on squamous cell carcinoma.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Adhesion; Cell Differentiation; Cell Division; Drug Screening Assays, Antitumor; Extracellular Matrix Proteins; Head and Neck Neoplasms; Humans; Transforming Growth Factor beta; Tretinoin; Tumor Cells, Cultured

Retinoids are a group of vitamin A analogues that have shown promise as chemopreventive and therapeutic agents in many types of malignancy and have been entered in clinical trials with some successful results. To better understand the mechanism that mediates retinoid action and the anti-proliferative effects, we treated 7 human oral squamous-cell carcinoma (SCC) cell lines (FADU, HEp-2, CCL-17, SCC-9, SCC-15, SCC-25 and HN-212) with 10(-6) M of all-trans retinoic acid (ATRA), 9-cis and 13-cis retinoic acid (RA) in continuous for different periods of time. We assessed the extent of growth inhibition, the stability of the anti-proliferative effect and the mRNA expression levels (by RT-PCR) of RA receptors (RARs), retinoid X receptors alpha (RXR alpha) and cytosolic RA-binding proteins (CRBP I and CRABP II) in treated cells compared with controls. The data obtained showed that all 3 RAs were able to inhibit the cellular growth of the tested cell lines, although to a different extent. The cis compounds were able to inhibit the proliferation of all cell lines, whereas ATRA was ineffective in inhibiting the proliferation of the CCL-17 cell line, which was naturally resistant to ATRA concentrations in the range between 10(-5) and 10(-6) M. All inhibitory effects were completely reversible since all cell lines restored their normal growth proliferation within few days after drug removal. RT-PCR analysis of the receptor and cell binding protein status of control and treated cells showed a good correlation between growth inhibition and induction of, or increase in, the expression levels of RAR beta in RA-treated cells. No differences were observed in RAR alpha and RXR alpha mRNA expression levels between control and treated cells. CRBP I, CRABP II and RAR gamma mRNA levels increased in some treated cell lines but not in all.

Topics: Alitretinoin; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Cycle; Cell Division; Drug Evaluation, Preclinical; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Growth Inhibitors; Humans; Isotretinoin; Mouth Neoplasms; Neoplasm Proteins; Polymerase Chain Reaction; Receptors, Retinoic Acid; Retinoid X Receptors; Retinol-Binding Proteins; Retinol-Binding Proteins, Cellular; Transcription Factors; Tretinoin; Tumor Cells, Cultured; Up-Regulation

Topics: Carcinoma, Squamous Cell; Cell Division; Humans; Receptors, Retinoic Acid; Retinoid X Receptors; RNA, Messenger; Transcription Factors; Tretinoin; Tumor Cells, Cultured

Retinoids are vitamin A analogs that regulate growth and differentiation of squamous epithelial cells in vitro and in vivo. We examined the effects of retinoic acid (RA) and N-(4-hydroxy-phenyl) retinamide (HPR) on the growth properties of esophageal squamous carcinoma cell lines, and found that both RA and HPR induce morphological changes and inhibit growth. Immunofluorescence studies suggest alterations in keratins as a result of treatment with RA or HPR. In order to determine underlying molecular mechanisms, we found that RA or HPR did not induce arrest of cells in the G1 phase nor did treated cells undergo apoptosis. However, RA and HPR treatment did result in the downregulation of epidermal growth factor receptor (EGFR) which is known to bind key proproliferative ligands, such as epidermal growth factor and transforming growth factor alpha.

Topics: Antineoplastic Agents; Apoptosis; Blotting, Western; Carcinoma, Squamous Cell; Cell Division; Cell Size; ErbB Receptors; Esophageal Neoplasms; Fenretinide; Flow Cytometry; Humans; Keratins; Time Factors; Tretinoin; Tumor Cells, Cultured

Cyclooxygenase-2 expression is up-regulated in transformed cells and tumors. Because this enzyme catalyzes the synthesis of prostaglandins, strategies aimed at suppressing its expression may prove useful in preventing or treating cancer. We investigated the ability of retinoids to suppress phorbol ester-mediated induction of cyclooxygenase-2 in human oral epithelial cells. Treatment with phorbol myristate acetate (PMA) resulted in approximately a 3-fold increase in the production of prostaglandin E2 (PGE2). Retinoids [all-trans-retinoic acid (RA), 13-cis-RA, and retinyl acetate] markedly suppressed PMA-mediated increases in amounts of cyclooxygenase-2 (Cox-2) and the production of PGE2. Retinoids also suppressed the induction of Cox-2 mRNA by PMA. Nuclear run-offs revealed increased rates of Cox-2 transcription after treatment with PMA; this effect was inhibited by all-trans-RA. Transient transfection experiments showed that PMA caused about a 2-fold increase in Cox-2 promoter activity, an effect that was suppressed by all-trans-RA. Our data indicate that treatment of oral epithelial cells with PMA is associated with enhanced transcription of Cox-2 and increased production of PGE2. These effects of PMA were inhibited by retinoids.

Topics: Anticarcinogenic Agents; Biotransformation; Carcinoma, Squamous Cell; Cyclooxygenase 2; Dinoprostone; Diterpenes; Enzyme Induction; Gene Expression Regulation, Neoplastic; Humans; Isoenzymes; Isotretinoin; Membrane Proteins; Mouth Neoplasms; Neoplasm Proteins; Peroxidases; Prostaglandin-Endoperoxide Synthases; Retinyl Esters; Tetradecanoylphorbol Acetate; Transcription, Genetic; Tretinoin; Tumor Cells, Cultured; Vitamin A

Changes in ultrastructural characteristics and mucin gene expression were examined in rat tracheal explants cultured in a synthetic medium +/- retinoic acid (RA), benzo[a]pyrene (B[a]P) and N-methyl-N-nitrosourea (NMNU). In the RA(+) cultures, no changes in either ultrastructural features or mucin gene expression were detected after 48 h incubation. After 96 h incubation, however, the ultrastructural features associated with the squamous phenotype were characteristics of cultures containing the two carcinogens and the mucin gene expression was slightly reduced. Thus, in the presence of retinoic acid, the carcinogen induced changes in cytology to the squamous phenotypes were not matched by a marked loss of mucin gene expression. Explants cultured for 48 h without RA and +/- carcinogens showed none of the cytological changes associated with onset of the squamous phenotype. While mucin mRNA was still detected, it was clearly reduced compared to 48 h cultures in RA(+) medium. However, 48 h later, all explants exhibited pronounced squamous metaplasia and the mucin message decreased to trace levels. Thus, the results of these experiments with B[a]P and NMNU in RA(+) and RA(-) media indicates that at least the early carcinogen induced changes may be distinct from those associated with the retinoid pathway controlling expression of the mucin component of the mucociliary epithelium.

Topics: Animals; Benzo(a)pyrene; Carcinogens; Carcinoma, Squamous Cell; Cell Differentiation; Culture Media; Culture Techniques; Epithelium; Gene Expression; Lung Neoplasms; Metaplasia; Methylnitrosourea; Mucins; Phenotype; Rats; RNA, Messenger; Trachea; Tretinoin; Vitamin A Deficiency

Retinoids can reverse potentially premalignant lesions and prevent second primary tumours in patients with head and neck squamous cell carcinoma (HNSCC). Furthermore, it has been reported that acquired resistance to all-trans retinoic acid (RA) in leukaemia is associated with decreased plasma peak levels, probably the result of enhanced retinoid metabolism. The aim of this study was to investigate the metabolism of retinoids and relate this to growth inhibition in HNSCC. Three HNSCC cell lines were selected on the basis of a large variation in the all-trans RA-induced growth inhibition. Cells were exposed to 9.5 nM (radioactive) for 4 and 24 h, and to 1 and 10 microM (nonradioactive) all-trans RA for 4, 24, 48 and 72 h, and medium and cells were analysed for retinoid metabolites. At all concentrations studied, the amount of growth inhibition was proportional to the extent at which all-trans-, 13- and 9-cis RA disappeared from the medium as well as from the cells. This turnover process coincided with the formation of a group of as yet unidentified polar retinoid metabolites. The level of mRNA of cellular RA-binding protein II (CRABP-II), involved in retinoid homeostasis, was inversely proportional to growth inhibition. These findings indicate that for HNSCC retinoid metabolism may be associated with growth inhibition.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Division; Chromatography, High Pressure Liquid; Culture Media; Head and Neck Neoplasms; Humans; Receptors, Retinoic Acid; Retinoids; Tretinoin; Tumor Cells, Cultured

Retinoids are natural and synthetic analogues of vitamin A and have proven activity in various types of cancer. As for head and neck squamous cell cancer (HNSCC), retinoids are especially active in leukoplakia and in preventing second primary cancers. The aim of this study was to assess the growth inhibiting activity of all-trans retinoic acid (all-trans RA) in a panel of six head and neck squamous cell cancer cell lines and to correlate this response to the mRNA expression of factors related to differentiation and receptor mediated signal transduction. Three lines showed minimal, two moderate and one strong growth inhibition after 72 h exposure to all-trans RA. Three lines with a dissimilar response were selected for further studies, the measurement of mRNA expression by northern blotting. It was found that neither the expression nor the induction of retinoic acid receptor (RAR)-alpha and -gamma and retinoic X receptor-alpha mRNA war related to sensitivity. The mRNA expression of RAR-beta was too low to be measured in the three cell lines. The most sensitive cell line was, however, the only one that expressed mRNA of squamous differentiation markers. These data suggest a relationship between the retinoid sensitivity profile and the degree of cellular differentiation.

Topics: Carcinoma, Squamous Cell; Cell Division; Cornified Envelope Proline-Rich Proteins; Gene Expression Regulation, Neoplastic; Head and Neck Neoplasms; Humans; Keratins; Membrane Proteins; Neoplasm Proteins; Proteins; Receptors, Retinoic Acid; RNA, Messenger; RNA, Neoplasm; Tretinoin; Tumor Cells, Cultured

Topics: Anticarcinogenic Agents; Antineoplastic Agents; Blotting, Northern; Blotting, Western; Carcinogens; Carcinoma, Squamous Cell; Cyclooxygenase 2; Dinoprostone; Diterpenes; Gene Expression Regulation, Enzymologic; Humans; Isoenzymes; Isotretinoin; Membrane Proteins; Peroxidases; Phorbol Esters; Prostaglandin-Endoperoxide Synthases; Retinoids; Retinyl Esters; Tretinoin; Tumor Cells, Cultured; Vitamin A

Cisplatin exerts its cytotoxicity by inducing apoptosis. Similarly, all-trans retinoic acid (ATRA) causes apoptosis in certain cells. We studied the interaction of cisplatin and ATRA in human ovarian adenocarcinoma cells 2008, in human head and neck squamous carcinoma cells UMSCC10b, and in their respective cisplatin-resistant sub-lines. ATRA enhanced the cytotoxicity of cisplatin. The interaction of the drugs was synergistic in combination index-isobologram analyses (combination index >0.5 at 50% cell survival) in all of the cell lines tested. ATRA inhibited the cellular accumulation of the cisplatin analogue [3H] cis-dichloroethylenediamineplatinum(II) by 22-33% in three of four cell lines tested but did not alter the cellular content of reduced glutathione. The expression of Bcl-2 relative to Bax decreased more after combined treatment with cisplatin and ATRA than after either drug alone. The apoptotic mechanism of cell death was confirmed by demonstrating cleavage of poly(ADP-ribose)polymerase and by morphological analysis. The combined treatment with ATRA and cisplatin induced apoptosis in significantly more cells than either drug alone. We conclude that ATRA enhances the cytotoxicity of cisplatin by facilitating apoptosis in ovarian and head and neck carcinoma cells.

Topics: Adenocarcinoma; Apoptosis; Carcinoma, Squamous Cell; Cell Survival; Cisplatin; Dose-Response Relationship, Drug; Drug Synergism; Female; Head and Neck Neoplasms; Humans; Kinetics; Ovarian Neoplasms; Tretinoin; Tumor Cells, Cultured

Retinoids inhibit the growth and reverse aberrant differentiation of squamous cell carcinoma (SCC) cells in vitro. To investigate the potential mechanisms of antitumor activity of retinoids in vivo, we used the cervical SCC cell line ME-180 as a s.c. tumor xenograft in athymic nude mice. After s.c. injection, tumor cells were allowed to form visible tumors and antitumor activity of all-trans-retinoic acid (tRA) was studied. tRA was administered daily for a 1-week or a 2-week period at 60 mg/kg/day. Tumor specimens were then analyzed using immunohistochemical staining for the number of blood vessels and apoptotic cells and for proliferating cell nuclear antigen expression. Furthermore, we studied the effect of the tRA treatment on the expression of a binding protein for fibroblast growth factors (BP; Gen-Bank accession no. M60047) that is a candidate angiogenesis modulator in SCC (F. Czubayko et al., J. Biol. Chem., 269: 28243-28248, 1994). We found that in vivo tRA treatment reduces BP expression in SCC xenografts, inhibits their angiogenesis, induces apoptosis of the tumor cells, and leads to a decrease of the tumor growth rate. We speculate that the tRA down-regulation of BP is responsible for the reduction of angiogenesis.

Topics: Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Cell Differentiation; Drug Screening Assays, Antitumor; Female; Humans; Keratinocytes; Mice; Mice, Nude; Neoplasm Transplantation; Neovascularization, Pathologic; Proliferating Cell Nuclear Antigen; RNA, Messenger; Tretinoin; Tumor Cells, Cultured; Uterine Cervical Neoplasms

Retinoic acid (RA) has been shown to be effective in eradicating premalignant lesions and preventing second primary malignancies in patients cured of squamous cell carcinoma of the head and neck (SCCHN) in clinical trials. The basis for this effect is unclear. We have previously demonstrated that messenger RNA from tumor growth factor-alpha (TGF-alpha) and its receptor, the epidermal growth factor (EGFR), is unregulated in tumors and histologically normal mucosal samples from patients with SCCHN compared with control normal mucosa from patients without cancer, implicating this ligand-receptor pair in an autocrine growth pathway early in the molecular pathogenesis of this disease. In this report, we examined the hypothesis that the action of RA on the mucosa of the upper aerodigestive tract is mediated via downregulation of steady-state TGF-alpha and/or EGFR mRNA levels. Following exposure to all-trans-RA, a series of SCCHN cell lines demonstrated a 35.4% reduction in TGF-alpha mRNA expression (P = 0.022) and 58.5% reduction in EGFR mRNA (P = 0.0027). Nuclear run-on analysis indicated that the RA-mediated reduction of TGF-alpha and EGFR steady-state mRNA levels was a result of decreased gene transcription. These results suggest that the clinical effects of RA in SCCHN patients may be due to a downmodulation of TGF-alpha and EGFR mRNA production.

Topics: Carcinoma, Squamous Cell; Down-Regulation; Epidermal Growth Factor; Head and Neck Neoplasms; Humans; Keratolytic Agents; Mouth Mucosa; RNA, Messenger; Transcription, Genetic; Transforming Growth Factor alpha; Tretinoin; Tumor Cells, Cultured

Retinoic acid (RA) modulates the growth and differentiation of various normal and malignant cells. These effects are most likely mediated by changes in gene expression. Genes whose expression is modulated by RA may be useful as markers of growth responsiveness to retinoids. Using differential cDNA cloning we identified 10 genes regulated by RA in the head and neck squamous cell carcinoma cell line MDA886Ln. Keratin (K) 13 gene expression was the gene expression most related to the degree of sensitivity of growth to RA, as K13 was not expressed in a series of RA-resistant cell lines. Our data suggest that low K13 expression may be mechanistically related to resistance to RA-induced growth inhibition.

Topics: Carcinoma, Squamous Cell; Cell Division; DNA, Complementary; Epithelium; Gene Expression; Head and Neck Neoplasms; Humans; Keratins; RNA, Messenger; Tretinoin; Tumor Cells, Cultured

Nuclear retinoic acid receptors are considered to be the mediators of most of the effects of retinoic acid (RA) on gene expression. To explore the role of RA receptor gamma (RARgamma) in the growth and differentiation of SqCC/Y1 head and neck squamous carcinoma cells, they were transfected with RARgamma sense and antisense expression vectors and stable clones in which RARgamma expression was either increased or blocked were isolated. The growth inhibitory effect of RA in monolayer culture was enhanced in the sense transfectants and decreased in the antisense ones. The ability to form colonies in semisolid medium was abolished by RA in the sense transfectants, while the antisense transfected clones exhibited heterogeneous responses. The expression the squamous differentiation markers cytokeratin K1 transglutaminase type I, and involucrin was increased in the absence of exogenous retinoid in a sense transfected clone and decreased in an antisense transfected clone. RA suppressed squamous differentiation in both types of transfectant. The expression of epidermal growth factor receptor (EGFR) was higher in the antisense and lower in the sense transfectant than in the parental cells and RA decreased EGFR mRNA level in the parental and the sense transfectant but not in the antisense transfectant. In addition activator protein-1 (AP-1) binding activity was decreased by the RA treatment in the sense clones, but not in the antisense ones. These results suggest that RARgamma mediates the effects of RA on the cell growth both in monolayer culture and in semisolid medium possibly through AP-1 suppression.

Topics: Base Sequence; Carcinoma, Squamous Cell; Cell Differentiation; Cell Division; ErbB Receptors; Head and Neck Neoplasms; Humans; Molecular Sequence Data; Oligonucleotides, Antisense; Protein Binding; Receptors, Retinoic Acid; Retinoic Acid Receptor gamma; Transcription Factor AP-1; Transfection; Tretinoin; Tumor Cells, Cultured

The serum concentrations of all-trans (atRA) and 13-cis (13cRA) retinoic acid were determined by high performance liquid chromatography in 27 patients with squamous cell carcinoma of the head and neck and in 80 healthy controls. This investigation seemed relevant as ethanol is an aetiological factor in these cancers and has been suggested to interfere with the synthesis of atRA. Neither the serum concentration of atRA nor that of 13cRA differed between patients and controls. The serum atRA concentration did not differ between fasting and non-fasting patients, but the serum 13cRA concentration was significantly higher in non-fasting than in fasting patients, probably due to the dietary retinoid content.

Topics: Adult; Aged; Aged, 80 and over; Carcinoma, Squamous Cell; Case-Control Studies; Chromatography, High Pressure Liquid; Fasting; Female; Head and Neck Neoplasms; Humans; Isotretinoin; Male; Middle Aged; Tretinoin

The metabolic activity of cytochrome P-450 enzymes has been associated with an increased risk of developing lung cancer. We found previously that all-trans retinoic acid is catabolized by these oxidative enzymes, and that an inhibitor of this system discriminated between two populations of lung cancer patients. We examined the association between this metabolic phenotype and the risk of lung cancer in 85 subjects. The area under the plasma concentration x time curve (AUC) was calculated after a single oral dose of all-trans retinoic acid (45 mg/m2). The mean AUC for patients who had either squamous or large cell carcinomas was significantly lower than that of patients with adenocarcinomas (P = 0.0001) or control subjects (P = 0.01). Individuals with an AUC < 250 ng x h/ml had a greater likelihood of having squamous or large cell carcinoma (odds ratio = 5.93). This study suggests that the "rapid" catabolism of all-trans retinoic acid is linked to an increased risk of squamous or large cell cancers of the lung.

Topics: Adenocarcinoma; Analysis of Variance; Carcinoma, Large Cell; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Case-Control Studies; Disease Susceptibility; Female; Humans; Keratolytic Agents; Lung Diseases, Obstructive; Lung Neoplasms; Male; Middle Aged; Odds Ratio; Phenotype; Smoking; Tretinoin

Retinoids have shown great promise as chemopreventive against the development of squamous cell carcinomas of the upper aerodigestive tract. However, the exact mechanism by which they block new tumors from arising is unknown. Here, we report that 13-cis- and all-trans-retinoic acid, used at clinically achievable doses of 10(-6) mol/L or less, can directly and specifically affect cell lines cultured from oral squamous cell carcinomas, inducing them to switch from an angiogenic to an anti-angiogenic phenotype. Although retinoic-acid-treated and untreated tumor cells make the same amount of interleukin-8, the major inducer of neovascularization produced by such tumor lines, they vary in production of inhibitory activity. Only the retinoic-acid-treated cells produce a potent angio-inhibitory activity that is able to block in vitro migration of endothelial cells toward tumor cell conditioned media and to halt neovascularization induced by such media in the rat cornea. Anti-angiogenic activity is induced in the tumor cells by low doses of retinoids in the absence of toxicity with a kinetics that suggest that it could be contributing to the effectiveness of the retinoids as chemopreventive agents.

Topics: Animals; Breast Neoplasms; Carcinoma, Squamous Cell; Colonic Neoplasms; Cornea; Endothelium, Vascular; Female; Fibrosarcoma; Humans; Interleukin-8; Keratinocytes; Neovascularization, Pathologic; Neovascularization, Physiologic; Neutralization Tests; Phenotype; Rats; Rats, Inbred F344; Tongue Neoplasms; Transforming Growth Factor beta; Tretinoin; Tumor Cells, Cultured

Retinoids are potent regulators of growth and differentiation and have shown promise as chemotherapeutic agents against selected cancers in particular squamous cell carcinoma (SCC). Earlier studies from our laboratory showed that a secreted binding protein for fibroblast growth factors (BP) is expressed at high levels in SCC cell lines and tissue samples. Here we investigate whether retinoids affect BP gene expression in SCC. In six different human SCC cell lines, we found that all-trans-retinoic acid (tRA) down-regulated BP mRNA by 39-89% within 24 h. From this group of cell lines, we selected the ME-180 cell line for more detailed studies of the mechanisms of this regulation. tRA down-regulated BP mRNA in a time- and dose-dependent manner. The effect of tRA was reversible, and BP mRNA returned to control levels within 24 h after removal of tRA. We also measured BP mRNA half-life and performed nuclear run-on experiments to study if tRA down-regulates BP by destabilizing the mRNA and/or by decreasing the rate of transcription. BP mRNA in ME-180 cells is very stable with a half-life of >16 h, and tRA decreased BP mRNA with a half-time of 5 h. Actinomycin D and cycloheximide blocked the tRA effect, suggesting that transcriptional regulation as well as de novo protein synthesis contribute to this post-transcriptional regulation of BP mRNA levels. In addition, tRA decreased the rate of BP gene transcription by 2- to 3-fold within 1 h. We conclude that retinoids down-regulate BP gene expression by post-transcriptional as well as by transcriptional mechanisms.

Topics: Carcinoma, Squamous Cell; Carrier Proteins; Cycloheximide; Dactinomycin; Down-Regulation; Fibroblast Growth Factors; Gene Expression Regulation; Humans; Intercellular Signaling Peptides and Proteins; Molecular Sequence Data; Protein Binding; RNA, Messenger; Transcription, Genetic; Tretinoin; Tumor Cells, Cultured

Topics: Carcinoma, Squamous Cell; Cell Count; Collagen; Culture Media; Drug Combinations; Laminin; Proteoglycans; Tretinoin; Tumor Cells, Cultured

Retinoic acid (RA) is a multifunctional drug that is particularly effective at preventing the development of multiple primary oral squamous cell carcinomas. A portion of this activity is due to the inhibition of tumor angiogenesis. It has been thought that RA influences tumor angiogenesis only via its interactions with the tumor cells themselves. Here, we test the hypothesis that the drug can also block neovascularization by directly inhibiting the angiogenic activity of normal endothelial cells. Clinically achievable doses of RA rapidly caused large- and small-vessel endothelial cells to become refractory to stimulation of migration either by tumor-conditioned media or purified angiogenic factors (a-fibroblast growth factor (aFGF), bFGF, vascular endothelial GF, platelet-derived GF, TGF beta-1, and IL-8). However, RA had little effect on their proliferation. Inhibition of migration was complete within 3 hours and was reversed 36 hours after drug removal. The migration of human oral keratinocytes was not sensitive to RA, whereas the migration of fibroblasts and vascular smooth muscle cells was inhibited. To determine if systemic RA affected neovascularization, rats were given 1 mg/kg/day of all-trans RA and their angiogenic potential was tested by implanting pellets of tumor-conditioned media into their avascular corneas. This treatment rendered the rats unable to mount a neovascular response in their corneas. These data demonstrate that RA directly affects endothelial cells, rapidly and reversibly inhibiting their ability to migrate toward a variety of stimuli in vitro and halting the formation of new vessels in vivo. These direct effects on vascular cells seem likely to contribute to the success of RA as a chemopreventive agent for oral squamous cell carcinoma.

Topics: Animals; Carcinoma, Squamous Cell; Cattle; Cell Division; Cell Line; Cell Movement; Cornea; Culture Media, Conditioned; Drug Implants; Endothelium, Vascular; Humans; Neovascularization, Pathologic; Tretinoin

Retinoids have been shown to inhibit the growth and modulate the glycosylation of head and neck squamous cell carcinoma (HNSCC) cells including the MDA886Ln cells. To examine the effects of beta-all-trans retinoic acid (RA) on glycoconjugates in HNSCC MDA886Ln cells, the cells were grown in the absence or presence of 1 microM RA and then labeled with tritiated monosaccharides, extracted and analysed by polyacrylamide gel electrophoresis and fluorography. RA increased markedly the incorporation of [3H]-glucosamine, [3H]-galactose, and [3H]-mannose into numerous cellular glycoconjugates, however, the incorportion of [3H]-fucose and [3H]-leucine was almost unaffected by RA. RA increased the incorporation of glucosamine and galactose but not mannose into high molecular weight (HMW) glycoconjugates of about 220 and 500-600 kDa. To analyse the steady state level of glycoconjugates by lectin blotting, extracts of unlabeled cells were separated by gel electrophoresis and the gels were probed with 125I-labeled wheat germ agglutinin (WGA) and Maackia amurensis (MA) agglutinin. Both lectins were found to bind to numerous glycoconjugates including the HMW glycoconjugates, whereas 125I-peanut agglutinin bound only to the HMW glycoconjugates RA treatment increased the binding of all three lectins to the HMW glycoconjugates. These findings demonstrate that RA enhanced the incorporation of specific monosaccharides into a variety of glycoconjugates and in particular into HMW mucin-like glycoconjugates. This effect of RA may be the result of induction of a more normal differentiation state of the HNSCC cells.

Topics: Agglutinins; Carcinoma, Squamous Cell; Cell Differentiation; Cell Division; Electrophoresis, Polyacrylamide Gel; Galactose; Glucosamine; Glycoconjugates; Glycosylation; Head and Neck Neoplasms; Humans; Lectins; Leucine; Mannose; Microscopy, Fluorescence; Microscopy, Phase-Contrast; Molecular Weight; Tretinoin; Tumor Cells, Cultured

Both retinoic acid (RA) and the synthetic retinoid N-(4-hydroxyphenyl)retinamide (4HPR) have shown efficacy in head and neck cancer chemoprevention trials. To compare their activity and mechanism of action, the 1483 oral head and neck squamous cell carcinoma (HNSCC) cell line was grown in organotypic culture, an in vitro system that allows cellular stratification and simulates carcinoma in situ, and was exposed to 10 micromol/L of either RA or 4HPR. Extensive apoptosis, as evidenced by in situ deoxyribonucleic acid end-labeling, occurred in 4HPR-treated cultures after 9 days, with >80% cell loss (P< .001). In contrast, the growth of cultures treated with RA was inhibited by only 32%, with no evidence of apoptosis. Because 4HPR has low systemic toxicity and is a potent inducer of apoptosis in HNSCC cells, its role in chemoprevention of head and neck cancers, including cancers that are resistant to RA-induction therapy, warrants further investigation.

Topics: Apoptosis; Carcinoma, Squamous Cell; Drug Screening Assays, Antitumor; Fenretinide; Head and Neck Neoplasms; Humans; Tretinoin; Tumor Cells, Cultured

Cisplatin (DDP) is commonly used to treat head and neck tumors. Therapy frequently fails due to development of DDP resistance or toxicities associated with DDP therapy. In this study, effects of ALRT1057 [9-cis retinoic acid (9-cis RA)] on DDP cytotoxicity were studied in a human oral squamous carcinoma xenograft model. Mice bearing xenografts were dosed p.o. daily 5 days/week with 30 mg/kg 9-cis RA and/or i.p. twice weekly with 0.3-0.9 mg/kg DDP. Maximum tolerated doses of 9-cis RA and DDP were approximately 60 and >/=2.9 mg/kg, respectively, under their dosing schedules and routes of administration. Control tumors grew rapidly with mean doubling times of 4 +/- 1 days and reached mean volumes of 1982 +/- 199 (SE) mm3 after 24 days. DDP at doses of 0.3, 0.45, and 0.9 mg/kg inhibited tumor growth by 28, 47, and 86%, respectively, 24 days after tumor cell implantation. Thirty mg/kg 9-cis RA inhibited tumor growth by 25%. In combination, 0.3 mg/kg DDP + 30 mg/kg 9-cis RA inhibited tumor growth by 68%; 0.45 mg/kg DDP + 30 mg/kg 9-cis RA inhibited growth by 78%. These decreases were greater than those that would have been produced by either agent summed separately. Of importance, at doses of 9-cis RA that enhanced DDP cytotoxicity, no change in dose tolerance was observed as compared to tolerances observed for either agent alone, indicating that 9-cis RA increased sensitivity to DDP without altering systemic toxicity. In addition, 9-cis RA profoundly altered squamous cell carcinoma phenotypes by suppressing squamous cell differentiation, resulting in tumors with increased numbers of basal cells. In contrast, DDP selectively depleted proliferating basal cells from carcinomas. In combination, morphological changes produced by 9-cis RA alone predominated, suggesting a possible basis for enhanced DDP sensitivity in tumors exposed to both agents. These data demonstrate that 9-cis RA enhances tumor sensitivity to DDP, and suggest that this combination should be tested in Phase I-II clinical trials for its potential for improving anticancer therapy of squamous cell cancers.

Topics: Alitretinoin; Animals; Antineoplastic Combined Chemotherapy Protocols; Bromodeoxyuridine; Carcinoma, Squamous Cell; Cisplatin; Female; Humans; Mice; Mice, Nude; Mouth Neoplasms; Neoplasm Transplantation; Receptors, Retinoic Acid; Retinoid X Receptors; Transcription Factors; Transplantation, Heterologous; Tretinoin

Retinoids have been shown to act as cytostatic agents against a variety of tumor cell types, including squamous carcinoma cells. Recently it was reported that certain retinoids can induce apoptosis as well. Because we are investigating the potential of retinoids in chemoprevention and therapy for head and neck premalignant and malignant lesions, we compared the effects of all-trans-retinoic acid (ATRA) and N-(4-hydroxyphenyl)retinamide (4HPR) on seven human head and neck squamous cell carcinoma cell lines (17A, 17B, 22A, 22B, 38, SqCC/Y1, and 1483). Six of the seven cell lines showed dramatic morphological changes after treatment with 10 micrometer 4HPR, whereas no such changes were induced by 10 micrometer ATRA. To determine whether these retinoids can induce apoptosis, we analyzed both detached and attached cells after 2, 5, and 7 days of treatment for evidence of DNA fragmentation by DNA electrophoresis on agarose gels. In five of the seven cell lines, a DNA ladder was observed after treatment with 10 micrometer 4HPR for 5 or 7 days, whereas treatment with ATRA resulted in a less pronounced effect. In 17B cells, a clear DNA ladder was observed as early as 2 days after treatment with 4HPR; however, neither ATRA nor 9-cis-retinoic acid was as effective. In addition, morphological changes associated with apoptotic cell death, such as chromatin condensation and nuclear segmentation, were observed by propidium iodide staining and by electron microscopic analysis after 4HPR treatment. These results demonstrate that 4HPR causes apoptosis in several head and neck squamous cell carcinoma cell lines and that it is more potent in this effect than ATRA.

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Fenretinide; Head and Neck Neoplasms; Humans; Tretinoin; Tumor Cells, Cultured

Liarozole showed antitumoral activity in the Dunning AT-6sq, an androgen-independent rat prostate carcinoma. To investigate its potential mechanism of action, the effects of the drug doses (ranging from 3.75 to 80 mg/kg b.i.d.) on endogenous plasma and tissue all-trans-retinoic acid levels and on the differentiation status of the tumor cells were evaluated. To follow modulation of differentiation, cytokeratins were localized in the (un)treated tumors by immunocytochemistry and quantitatively determined by immunoblotting. Results showed that liarozole statistically significantly reduced tumor weight from 30 mg/kg upwards and induced accumulation of all-trans-retinoic acid both in plasma and tumors. In the tumors, a statistically significant accumulation was already noted from 7.5 mg liarozole/kg upwards. Concomitantly, the differentiation status shifted from a keratinizing towards a non-keratinizing squamous carcinoma, which was further confirmed by the cytokeratin profile of the carcinoma (presence of CK 8, 10, 13, 14, 18, 19). Immunoblotting revealed an overall decrease in cytokeratin content, except for CK 8. These findings suggest that the antitumoral properties of liarozole might be related to an increase in the degree of tumor differentiation through accumulation of all-trans-retinoic acid.

Topics: Animals; Antibodies, Monoclonal; Antineoplastic Agents; Carcinoma, Squamous Cell; Dose-Response Relationship, Drug; Gene Expression Regulation, Neoplastic; Imidazoles; Immunoblotting; Immunohistochemistry; Keratins; Male; Neoplasm Transplantation; Organ Size; Prostate; Prostatic Neoplasms; Random Allocation; Rats; Rats, Inbred F344; Tretinoin; Tumor Cells, Cultured; Vimentin

The in vivo and in vitro antitumor effectiveness of IFNs is well documented. Their combination with differentiating agents, such as retinoic acid, has been demonstrated to be a promising therapy for patients with advanced squamous cell cancer of the skin and the cervix. However, the mechanisms that mediate these antitumor responses are not yet known. We studied the epidermoid cell line ME 180 derived from human cervical carcinoma to test its responsiveness to IFN-alpha-2b (INTRON A) and all-trans-retinoic acid (RA). Both agents have demonstrated ability to inhibit the growth of ME 180 cells in a dose- and time-dependent manner. The antiproliferative effect was further increased by the treatment with IFN-alpha-2b and RA combined. In accordance with this result, we found that the combination of the two agents has the effect of increasing the expression of the 2-5A synthetase gene, which is thought to play a key role in antigrowth responses to IFNs. At increased levels of 2-5A synthetase mRNA corresponds a significant increase in 2-5A synthetase activity. Although RA per se has no effect on the 2-5A synthetase expression, when it is combined with IFN-alpha-2b it appears to be able to potentiate the IFN-induced 2-5A synthetase expression. Moreover, the combination of IFN-alpha-2b and RA produces a similar effect also on the expression of the HLA-A2 gene, which has been shown to be induced in ME 180 cells both by IFN-alpha-2b and RA alone. In view of the possible mechanisms of action of the two agents, it is interesting to note that their combination increases, although transiently, the expression of IRF1, which codes for a transcription factor that regulates IFN gene expression and is thought to be involved in the regulation of IFN-induced effects and in mediating cell death or apoptosis.

Topics: 2',5'-Oligoadenylate Synthetase; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Squamous Cell; Cell Division; DNA-Binding Proteins; Drug Synergism; Female; Gene Expression; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Interferon alpha-2; Interferon Regulatory Factor-1; Interferon-alpha; Phosphoproteins; Receptors, Retinoic Acid; Recombinant Proteins; RNA, Messenger; Stimulation, Chemical; Transcription Factors; Tretinoin; Tumor Cells, Cultured; Uterine Cervical Neoplasms

The folate receptor is a 38 to 39 kd glycoprotein attached to the cell membrane via a glycosylphosphatidylinositol anchor. It serves as the initiation point for receptor-coupled transport of folate in a process known as potocytosis. The receptor is overproduced by a number of malignant cell lines in vitro and in a large percentage of ovarian and uterine malignancies. Immunohistochemistry has shown the receptor to be expressed primarily in normal differentiated tissues such as choroid plexus, placenta, thyroid, and kidney. The receptor gene(s) has been mapped to the human chromosomal locus 11q13.. In order to better understand regulation of the synthesis of the receptor, we studied the expression and accumulation of the folate receptor in UMSCC 38 cells, a human malignant squamous cell carcinoma line with a karyotype that is amplified at the folate receptor gene locus.. Western blot analysis of octylglucoside-solubilized cell membranes was used to analyze expression of several proteins by UMSCC 38 cells grown in culture under varied conditions. Bands on autoradiographs, representing electrophoresed proteins detected by indirect antibody labeling and an enhanced chemiluminescence reaction, were quantitated by densitometry.. The expression of the folate receptor was found to increase approximately fourfold as UMSCC 38 cells were grown to higher cell densities over increasing lengths of time, ranging from 3 to 9 days, in culture. The expression of K1 keratin protein, a known marker of differentiation in squamous cell carcinomas, was elevated to a similar degree (3.2-fold) between day 5 and day 9 in cultures of these cells. Expression of folate-receptor protein in UMSCC 38 cells was also found to be reduced approximately 10-fold when cells were exposed to 1 microM retinoic acid for 48 hours and increased approximately eightfold after a 5-day exposure to 3 microM hydrocortisone.. We present evidence that synthesis of the folate receptor in UMSCC 38 cells is affected by the same pathway that changes the expression of some markers of differentiation in squamous cell carcinomas.. The fact that folate receptor expression in these malignant cells can be manipulated using retinoids and steroids suggests that these hormones could modulate the efficiency of folate and antifolate uptake via the folate receptor and may enhance the usefulness of the receptor as a target for immunotherapy.

Topics: Antigens, Differentiation; Blotting, Northern; Carcinoma, Squamous Cell; Carrier Proteins; Electrophoresis, Polyacrylamide Gel; Folate Receptors, GPI-Anchored; Folic Acid; Gene Expression Regulation, Neoplastic; Humans; Hydrocortisone; Receptors, Cell Surface; Tretinoin; Tumor Cells, Cultured

We have previously shown that beta-all trans retinoic acid (RA) inhibits macrocellular growth of a multicellular tumor spheroid model for squamous carcinoma, as measured by spheroid size, but allows for continuing DNA synthesis and cell cycle progression, the two being reconciled by a cell death effect. DNA synthesis in the presence of growth inhibition suggested a rationale for examining combination chemotherapy with RA-inhibited cells. To this aim, we have extended this observation to a series of 8 squamous carcinoma cell lines. Cells were treated with 1 microM RA for 7 days and cell growth parameters monitored. Although growth inhibition ranged from 0% (A431) to approx. 80% (MDA 886Ln), [3H]-thymidine incorporation (cpm/microgram protein) and percent S-phase (by flow cytometry) in 7-day RA-treated cells was equal or higher than in their control vehicle-treated cells in 7/8 SCC cell lines. Thus RA-induced growth inhibition is not just cytostasis. Combination therapy was examined with MDA 886Ln, MDA 686Ln, 1483 and A431 cells pre-treated for 7 days with 1 microM RA followed by cisplatin or 5-fluorouracil treatment. An increased effectiveness for the combination was shown using 5-day tetrazolium dye (MTT) growth assays when cells were growth-inhibited by RA. Computerized analysis of data using median-effect and isobologram techniques indicated that the interaction of RA with these chemotherapeutic agents was synergistic. With squamous carcinoma, RA treatment inhibits growth while allowing for continuing DNA synthesis, and these RA-treated, growth-inhibited cells exhibit increased sensitivity to chemotherapeutic agents.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Cycle; Cell Division; Cell Line; Cell Survival; Cisplatin; DNA, Neoplasm; Dose-Response Relationship, Drug; Drug Therapy, Combination; Fluorouracil; Head and Neck Neoplasms; Humans; S Phase; Tretinoin; Tumor Cells, Cultured

We have identified and sequenced a new gene from human cells that is responsive to DNA damage and retinoic acid treatment, and it is highly expressed in brain and reproductive organs (BRE). This BRE gene encodes an mRNA of 1.7-1.9 kb, with an open reading frame of 1,149 bp, and gives rise to a deduced polypeptide of 383 amino acid residues. Treatment of fibroblast cell with UV and 4-nitroquinoline-1-oxide caused more than 90% and 50% decreases in BRE mRNA, respectively. Similar decreases in BRE expression were observed in RA-treatment of the brain glioma cell U-251 and the promyelocytic cell HL-60. Decrease in BRE mRNA was also observed in a squamous carcinoma cell, 1483, that showed X-ray resistance and has a more aggressive tumorigenic phenotype, but BRE expression was unchanged in cells after growth inhibition. These data indicate that BRE is a house-keeping gene and it may play a role in homeostatis or in certain pathways of differentiation in cells of neural, epithelial and germ line origins.

Topics: Amino Acid Sequence; Animals; Base Sequence; Brain; Carcinoma, Squamous Cell; Cell Line; Cloning, Molecular; DNA Damage; Female; Fibroblasts; Gene Expression; Genitalia; Glioma; Humans; Leukemia, Promyelocytic, Acute; Male; Molecular Sequence Data; Nerve Tissue Proteins; Organ Specificity; Rats; Rats, Sprague-Dawley; Sequence Homology, Amino Acid; Tretinoin; Tumor Cells, Cultured; Ultraviolet Rays

N(4-hydroxycarbophenyl) retinamide (RII) is a new synthetic analog of retinoids with low toxicity. Its effect on the biological properties associated with tumor malignant behavior of human nasopharyngeal carcinoma cell lines (HNCs), including CNE-2Z parent cell lines and their variants L2, H2, L4 was studied. RII (10(-5) mol/L) caused detectable morphologic differentiation of HNCs. It inhibited growth of HNCs in vitro and decreased ability of these cells to penetrate matrigel-coated filters by using a reconstituted basement membrane invasion assay. These results suggested that RII might be a kind of useful anticancer drug.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Humans; Nasopharyngeal Neoplasms; Neoplasm Invasiveness; Tretinoin; Tumor Cells, Cultured

The purpose of the present study was to establish culture conditions for human uterine cervical epithelial cells on permeable support and to determine how it affects cervical cell differentiation. Human ectocervical epithelial cells (hECE), HPV-16 immortalized hECE cells (ECE16-1) and Caski cells were grown on collagen-coated filters. Culture conditions, density of cells in culture and expression of epithelial and cervical-cell phenotypic markers were determined and compared in cells grown on filter and on solid support. Compared with the latter, cultures on filter had a higher cell density, hECE cells stratified to 5-12 cell layers compared to 1-3 on solid support, and cells of all three types expressed intercellular tight junctions. The cytokeratin profiles revealed differences between the three cell types as well as differences within the same cell species when grown on filter, compared to solid support. Of particular importance was the finding of a higher expression of K-13 in hECE grown on filter compared to solid support; K-13 is a marker of ectocervical cell differentiation. The cytokeratin profiles of the cultured hECE, ECE16-1 and Caski cells resembled those of ectocervical, squamous metaplastic and endocervical epithelia, respectively. hECE and ECE16-1 expressed involucrin protein, the level of which in both was higher in cells grown on filter compared to solid support. Polarization of the cultures was determined by morphology (stratification of hECE cells, expression of pseudomicrovilli in the apical cell membrane), selective apical vs. basolateral secretion of [35S]methionine- and [35S]cysteine-, [3H]fucose- and [14C]glucosamine-labeled molecules, and positive short-circuit current (Isc) under voltage-clamp conditions. Confluency of the cultures was determined by measuring transepithelial unidirectional fluxes of inert molecules with different molecular weights (MWs) through the paracellular pathway, and by measuring transepithelial conductance. The results indicated transepithelial permeability of 7-22.10(-6) cm.sec-1, which was 5-100 fold smaller compared to blank inserts, with a cut-off MW of 40-70 kDa for hECE and Caski cells. Transepithelial conductance ranged 18.5 to 51.5 mS.cm-2, indicating a leaky but confluent epithelia. Collectively the results indicate the epithelial nature of the cells and their improved differentiation when grown on filter support; hECE is a model for ectocervical epithelium while ECE16-1 and Caski express phenoty

Topics: Carcinoma, Squamous Cell; Cell Differentiation; Cell Line, Transformed; Cell Polarity; Cells, Cultured; Ceramics; Cervix Uteri; Collagen; Culture Techniques; Epithelial Cells; Epithelium; Female; Humans; Hydrocortisone; Keratins; Permeability; Polytetrafluoroethylene; Protein Precursors; Tretinoin; Tumor Cells, Cultured; Uterine Cervical Neoplasms; Vimentin

The ability of all-trans-retinoic acid (RA) to modulate the growth and squamous differentiation of four head and neck squamous cell carcinoma cell lines (183, 886, 1483, and SqCC/Y1) was examined, and the relationship of their state of squamous differentiation and RA responsiveness to the expression of cytosolic RA-binding proteins (CRABPs), nuclear RA receptors (RARs), and retinoid X receptors (RXRs) was investigated. RA inhibited proliferation of all but the 183 cell line and suppressed squamous differentiation markers K1 keratin, type 1 transglutaminase, and involucrin mRNAs and proteins to varying degrees in 183, 1483, and SqCC/Y1 cells. Traces of CRABP-I mRNA were detected only in the 886 cells, whereas CRABP-II mRNA was detected in the other three cell lines. RA suppressed CRABP-II expression in SqCC/Y1 cells but had no effect on its expression in the other cell lines. All cell lines expressed mRNAs for RAR-alpha, RAR-beta, RAR-gamma, and RXR-alpha. The RAR-beta mRNA level was lowest in the SqCC/Y1 cells, and RXR-beta and RXR-gamma were not detected in any of the cell lines. RA treatment increased the levels of the three RAR mRNAs in most of the cell lines but had no effect on the RXR mRNAs. The CRABP-II mRNA level in SqCC/Y1 cells was lowest in cells grown in serum-free medium and increased when the cells were grown in medium with 5 or 10% serum. In contrast, the RXR-alpha mRNA level was inversely related to serum concentration. The results show that, in head and neck squamous cell carcinoma cells, there are no simple relationships among the expression of CRABPs, RARs, and RXRs and either squamous differentiation or response to RA-induced growth inhibition or suppression of squamous differentiation.

Topics: Carcinoma, Squamous Cell; Cell Differentiation; Head and Neck Neoplasms; Humans; Keratins; Protein Precursors; Receptors, Retinoic Acid; RNA, Messenger; Transglutaminases; Tretinoin; Tumor Cells, Cultured

Retinoids are inhibitors of tumour cell proliferation in culture and have been shown to suppress carcinogenesis and decrease the levels of proteases. The present study has demonstrated that retinoic acid is a potential non-competitive inhibitor of a protease (GB) immobilised on the surfaces of tumour cells in thin sections and free GB in solution. The enzymic status of GB on the cell surfaces in sections has been determined by challenging the retinoic acid-treated cells with a second fluorescent inhibitor (9-AA), followed by fluorescence microscopic analysis. The inhibition of cell surface GB by retinoic acid was demonstrated to be reversible. The activity of soluble GB has been measured by the MUGB assay in the presence and absence of retinoic acid. It is suggested that retinoic acid acts on GB by interacting with a binding site, different from the active site, and causes major conformational changes, resulting in enzyme inhibition. It is possible that the modulation of GB activity by retinoic acid may play a role in the control of cell migration and metastasis.

Topics: Alkaline Phosphatase; Aminacrine; Binding Sites; Carboxylic Ester Hydrolases; Carcinoma, Squamous Cell; Cell Membrane; Endopeptidases; Fibrinolysin; Histocytochemistry; Humans; Lung Neoplasms; Microscopy, Fluorescence; Protease Inhibitors; Tissue Plasminogen Activator; Tretinoin

A full-length cDNA (RA538) was isolated from human esophageal cancer cell line EC8712 after retinoic acid treatment. An expression vector of this cDNA (pRA538) was cotransfected with the neo gene (pDORneo) into parental cancer cell line EC8712. The cell colonies obtained after selection in G418-containing culture medium showed very poor growth, reduced (by 68%-76%) 3H-TdR uptake and morphological changes characteristic of terminal differentiation and programmed cell death (apoptosis). In situ hybridization with RA538 probes revealed expression of mRNA of RA538 in the cytoplasm of the transfected cells. The cells transfected solely with pDORneo after G418 selection showed normal growth pattern and no RA538 expression. However, none of the control cells EC8712 survived the G418 selection. Thus the expression of cDNA RA538 has a similar effect on the esophageal cancer cell EC8712 as the retinoic acid does.

Topics: Animals; Apoptosis; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; DNA, Complementary; Esophageal Neoplasms; Gene Expression; Humans; Mice; Mice, Nude; RNA, Messenger; Transfection; Tretinoin; Tumor Cells, Cultured

To evaluate the effects of gap junctional intercellular communication (GJIC) on the growth, invasion and metastasis of tumor, human nasopharyngeal carcinoma (HNPC) parent cell line (CNE-2Z) and its variants (L2, H2, L4) with different invasive and metastatic potential were examined in vitro. Only a few intermediate junction (IJ) but no gap junction (GJ) structures were observed under EM. The parent line cells showed marked GJIC, while its variants lacked this function by SLDT technique. It was further shown that L2 cell line (variant with high invasive potential) had lower concentration of cytosolic free calcium ([Ca2+]i) compared to H2, L4 cell lines (variants with medium and low invasive potential, respectively). It reflected that some correlation may exist between [Ca2+]i level and the invasive potential of HNPC cell lines. The effect of RII on GJIC of HNPC was also investigated. After 3-7 ds of RII (0.0001 mol/L) treatment, there was no change in the number of GJs. The GJIC function of CNE-2Z weakened and then disappeared finally with prolonged RII treatment. The level of [Ca2+]i in HNPC cells apparently fell after 6h of RII treatment, and rose to original level with persistent RII treatment. Whether the fluctuating of [Ca2+]i level relates the inhibitory effect of RII treatment. Treatment on the growth and invasion needs to be further studied.

Topics: Calcium; Carcinoma, Squamous Cell; Cell Communication; Gap Junctions; Humans; Nasopharyngeal Neoplasms; Neoplasm Invasiveness; Tretinoin; Tumor Cells, Cultured

Interferon gamma (IFN-gamma) is a potent inducer of squamous differentiation in normal human epidermal keratinocytes. This induction is characterized by a > or = 95% decrease in the mRNA level of two growth regulatory genes, cdc2 and E2F-1, and a 7-15-fold increase in the expression of two squamous cell-specific genes, transglutaminase type I and cornifin. In contrast to the decrease in cdc2 and E2F-1 expression, the increase in transglutaminase type I and cornifin mRNAs by IFN-gamma occurs after a lagtime of more than 12 h. These results are consistent with the hypothesis that in normal human epidermal keratinocyte cells irreversible growth arrest precedes the expression of the squamous-differentiated phenotype. The action of IFN-gamma on the expression of squamous cell-specific genes is antagonized by retinoic acid and transforming growth factor beta 1. Both factors are potent suppressors of the induction of transglutaminase type I and cornifin; however, they do not prevent the commitment to irreversible growth arrest. Several squamous cell carcinoma cell lines do not show a detectable decrease in cdc2 or increase in transglutaminase type I mRNA levels after IFN-gamma treatment and appear to be altered in their control of squamous differentiation.

Topics: Carcinoma, Squamous Cell; CDC2 Protein Kinase; Cell Differentiation; Cell Division; Cells, Cultured; Cornified Envelope Proline-Rich Proteins; DNA Probes; Gene Expression Regulation; Growth Substances; Humans; Interferon-gamma; Keratinocytes; Kinetics; Male; Membrane Proteins; Recombinant Proteins; RNA, Messenger; Skin; Skin Neoplasms; Transforming Growth Factor beta; Transglutaminases; Tretinoin; Tumor Cells, Cultured

Because of their antiproliferative and differentiation-inducing properties, retinoids have been used clinically as therapeutic and chemopreventive agents against squamous-cell carcinomas (SCC). As is the case for many therapeutic agents, however, the administration of retinoids is associated with toxic effects. Because encapsulation of certain drugs in lipid vesicles (liposomes) has been shown to result in reduced toxic effects, we studied the in vitro interaction of liposome-encapsulated all-trans-retinoic acid (L-ATRA) with a SCC line (MDA 886Ln) and its multicellular tumor spheroid (MTS) model. Various L-ATRA formulations were tested for incorporation of retinoic acid, toxic effects against human red blood cells, uptake and retention by tumor cells, and antiproliferative effects against SCC. Of the different formulations tested, L-ATRA containing diphosphatidyl palmitoylcholine (DPPC) and stearylamine (SA; 9:1, w/w) showed optimal drug incorporation, high stability, and minimal toxicity toward red blood cells and was highly efficacious in delivering ATRA and, thus, in inhibiting the growth of MDA 886Ln and its MTS model. DPPC: SA L-ATRA inhibited the expression of the enzyme keratinocyte transglutaminase in epidermal cells as effectively as did the free drug. These results suggest that liposomes can serve as an effective carrier system for the delivery of retinoids to SCC.

Topics: 1,2-Dipalmitoylphosphatidylcholine; Amines; Carcinoma, Squamous Cell; Cell Division; Erythrocytes; Humans; Liposomes; Middle Aged; Transglutaminases; Tretinoin; Tumor Cells, Cultured

The effect of 13-cis-retinoic acid (cRA) and all-trans-retinoic acid (tRA) used alone or in combination with interferon alpha-2a (alpha-IFN 2a) was tested on three established human cell lines: KB (epidermoid carcinoma of the oral cavity), SCC-25 (tongue squamous cell carcinoma) and MCF-7 (mammary carcinoma). Both retinoids significantly decreased cell proliferation (growth curves) and colony forming efficiency (CFE) in all cell lines, in a dose-dependent way (at a concentration ranging from 10(-5) to 10(-9) M) and differing from line to line, following the pattern: MCF-7 > SCC-25 > KB. Retinoids at any concentration (already at 10(-7) M) combined with alpha-IFN 2a (ranging from 100 to 500 IU/ml) were more effective in inhibiting cell proliferation than each of the two compounds alone. This was particularly evident with SCC-25 cells. Concerning MCF-7 cells, on the contrary, the effects produced by the association suggested a possible additive more than synergistic amplification of growth inhibition.

Topics: Breast Neoplasms; Carcinoma, Squamous Cell; Cell Division; Drug Screening Assays, Antitumor; Drug Synergism; Humans; Interferon-alpha; Isotretinoin; Mouth Neoplasms; Tretinoin; Tumor Cells, Cultured

Intrinsic fluorescence spectroscopy offers a new method for diagnosing head and neck cancers. By establishing a unique spectral fingerprint for benign tissue, one can readily identify subtle changes in tissue based on altered spectral patterns. The authors applied this technology to a multicellular tumor spheroid (MTS) model and obtained baseline spectral data. A cohort of MTS was treated with the chemopreventive agent retinoic acid (RA) to determine its effect on tumor cells. Excitation and emission spectroscopy were performed on the samples. Spectroscopic scans demonstrated consistently that RA-treated MTS exhibit a decrease in the peak associated with reduced nicotinamide-adenine dinucleotide (NADH) and an increase in the peaks associated with flavins, tryptophan, and cytokeratins when compared to controls. These findings are suggestive of alterations in cellular electron transport, an increase in proteins incorporating tryptophan, and a decrease in adenosine triphosphate (ATP) in the RA-treated cells. A discussion of the potential clinical applications of intrinsic fluorescence spectroscopy is included.

Topics: Carcinoma, Squamous Cell; Head and Neck Neoplasms; Humans; Spectrometry, X-Ray Emission; Tretinoin; Tumor Cells, Cultured

Stratified squamous epithelia have been shown to preferentially express a site-specific pattern of keratin intermediate filaments. Retinoic acid (RA) is known to modulate expression of the basal cell keratins K19 and K5. Expression of these genes is dependent on extracellular RA concentration. We have found that K19 mRNA levels increase over time in cultured keratinocytes exposed to elevated concentrations of RA. K5 mRNA levels decrease in response to RA in a similar fashion. The observed changes in K5 message are primarily the result of RA-induced alterations in gene transcription. However, the RA-mediated induction of K19 mRNA is not the result of increased transcription but is primarily due to enhanced mRNA stability. These results suggest that an RA-dependent post-transcriptional mechanism modulates K19 intermediate filament expression in stratified squamous epithelia.

Topics: Carcinoma, Squamous Cell; Cell Nucleus; Cells, Cultured; Cytoplasm; Half-Life; Humans; Keratinocytes; Keratins; Receptors, Retinoic Acid; RNA Processing, Post-Transcriptional; RNA, Messenger; Transcription, Genetic; Tretinoin; Tumor Cells, Cultured

We describe an animal model to induce the histogenesis of squamous metaplasia of the cervical columnar epithelium, a condition usually preceding cervical neoplasia. This model is based on dietary retinoid depletion in female mice. Control sibling mice fed the same diet but with all-trans-retinoic acid (at 3 micrograms/g diet) showed the normal endocervical epithelial and glandular columnar morphology, typical of a simple epithelium without subcolumnar reserve cells. The stratified squamous ectocervical epithelium of these mice fed all-trans retinoic acid showed intense immunohistochemical staining in basal and suprabasal cells with mono-specific antibodies against keratins K5, K14, K6, K13, and, suprabasally, with antibodies specific for K1 and K10. At the squamocolumnar junction, the adjacent columnar epithelium (termed "suprajunctional") did not show staining for K5, K14, K6, K13, K1, and K10 but specifically stained for keratin K8, typical of simple epithelia and absent from the adjacent ectocervical squamous stratified lining (termed "subjunctional"), in striking contrast. Sections of the squamocolumnar junction from mice kept on the vitamin A-deficient diet for 10 weeks showed suprajunctional isolated patches of reserve cells, proximal and distal to the junction. These cells were detected prior to any symptoms of vitamin A deficiency, such as loss of body weight or respiratory discomfort. The subcolumnar reserve cells induced by vitamin A deficiency displayed positive staining for K5 and K14. As deficiency became severe, the reserve cells occupied the entirety of the suprajunctional basement membrane. This epithelium eventually became stratified and squamous metaplastic, the squamocolumnar junction was no longer discernible, and the entire endocervical epithelium and the endometrial glands lost K8 positivity, while acquiring K5, K14, K6, K13, K1, and K10 keratins typical of the ectocervix under normal conditions of vitamin A nutriture. Vitamin A deficiency also altered keratin expression and localization in squamous subjunctional epithelium. In situ hybridization studies for K1 and K5 mRNA showed their major site of expression at the basal (K5) and immediately suprabasal (K1) cell layers. The localization of both K5 and K1 proteins in these same cell layers, and above, is consistent with transcriptional regulation of these keratins. Early vitamin A deficiency caused the appearance of single subcolumnar reserve cells expressing K5 mRNA. After these ce

Topics: Animals; Carcinoma, Squamous Cell; Cervix Uteri; Diet; Disease Models, Animal; Epithelium; Female; Immunohistochemistry; In Situ Hybridization; Keratins; Metaplasia; Mice; Mice, Inbred BALB C; Mice, Nude; Phenotype; Precancerous Conditions; Retinoids; RNA, Messenger; Tretinoin; Uterine Cervical Neoplasms; Vitamin A Deficiency

Humoral hypercalcemia of malignancy is a paraneoplastic syndrome associated with a variety of solid neoplasms including squamous cell carcinomas of various sites. Parathyroid hormone-related protein (PTHrP) is a newly recognized hormone that has been implicated as one of the major causative factors in the pathogenesis of this syndrome. A canine oral squamous carcinoma cell line (SCC 2/88) was used to investigate the regulation of production of PTHrP in response to agents that alter keratinocyte differentiation/proliferation in vitro.. SCC 2/88 cells grown in serum-free media were exposed to various factors and PTHrP production was measured by radioimmunoassay. This cell line spontaneously produced substantial amounts of PTHrP (up to 7,000 pg/ml) without the need for a fibroblast-feeder layer. Production of PTHrP decreased at cellular confluence, and with increasing passage number.. Epidermal growth factor, cholera toxin, calcium, 1,25-dihydroxyvitamin D, ionomycin, trans-retinoic acid, transforming growth factor-beta 1 and hydrocortisone stimulated production of PTHrP by SCC 2/88 cells to various degrees. Transforming growth factor-beta 1 was the most potent stimulator of PTHrP production, with a maximal stimulation of 25-fold over control. Monensin decreased PTHrP secretion as early as 6 hours post-treatment and by 48 hours, there was no detectable PTHrP in the conditioned cell culture medium. Calcium, cholera toxin, ionomycin, and transforming growth factor-beta 1 decreased keratinocyte proliferation as measured by cell counts at all doses tested.. The results of this study revealed that SCC 2/88 cells spontaneously produced substantial amounts of PTHrP under baseline conditions and that compounds known to affect keratinocyte differentiation/proliferation up-regulated production of PTHrP. These cells will be valuable to investigate the molecular regulation of PTHrP production by squamous cell carcinomas.

Topics: Animals; Calcitriol; Calcium; Carcinoma, Squamous Cell; Cell Differentiation; Cell Division; Cell Line; Cholera Toxin; Dog Diseases; Dogs; Dose-Response Relationship, Drug; Epidermal Growth Factor; Humans; Hydrocortisone; Ionomycin; Keratinocytes; Kinetics; Mouth Neoplasms; Neoplasm Proteins; Parathyroid Hormone-Related Protein; Protein Biosynthesis; Radioimmunoassay; Time Factors; Transforming Growth Factor beta; Tretinoin; Tumor Cells, Cultured

Retinoic acid receptor beta (RAR beta), which codes for a nuclear receptor for retinoic acid, is localized in a chromosomal region frequently deleted in lung cancer cells. The gene is expressed in normal lung tissue and in the majority of the cell lines derived from lung tumors but not in most of the lines derived from lung tumors with epidermoid characteristics. To study the possible role of RAR beta in growth control of epidermoid lung tumor-derived cells, transfectants expresing RAR beta were generated from nonexpressing epidermoid tumor-derived cell lines. Four clones were derived from line CALU-1, three of which showed a 20-60% increase in doubling time in the presence of retinoic acid. Parental and control-transfected cells were unaffected or slightly stimulated. All four clones expressing RAR beta were less tumorigenic in nude mice than were the untransfected or control-transfected cells, with about a 50% incidence of take vs. 95%. When tumors did develop from RAR beta-positive cells, they showed a reduced rate of growth, an increased latency, and, in six of seven tumors tested, a much reduced level of RAR beta expression. Transfectants derived from a second tumor line, H157, also showed a markedly reduced incidence of take in nude mice. Together with the known effects of retinoic acid on differentiation and carcinogenesis, our results support the hypothesis that RAR beta functions as a tumor suppressor gene in epidermoid lung tumorigenesis.

Topics: Animals; Carcinoma, Squamous Cell; Carrier Proteins; Cell Division; Genes, Tumor Suppressor; Humans; Lung Neoplasms; Mice; Mice, Nude; Neoplasm Proteins; Receptors, Retinoic Acid; Recombinant Proteins; RNA, Messenger; Simian virus 40; Transfection; Tretinoin; Tumor Cells, Cultured

Cellular retinoic acid-binding protein (CRABP) and cellular retinol-binding protein (CRBP) were localized in biopsies of normal squamous epithelium, cervical intraepithelial neoplasia (CIN), and invasive squamous cell cancer of the cervix uteri by immunohistochemistry. In both the normal stratified squamous epithelium of the exocervix and low-grade CIN, CRABP I was present predominantly in the basal layer of the epithelium. The more superficial, differentiated cell layers lacked immunoreactive protein. In high-grade CIN (CIN2-3), the distribution of CRABP I was altered. Immunoreactive CRABP I was detected in all layers of high-grade CIN. In squamous cell carcinoma of the cervix, CRABP I was detected in cells throughout the tumor but was minimal in cells demonstrating squamous differentiation. In contrast to CRABP I, CRBP was diffusely present throughout the cervical epithelium irrespective of the state of differentiation or the presence of disease.

Topics: Adolescent; Adult; Carcinoma, Squamous Cell; Carrier Proteins; Cervix Uteri; Female; Humans; Middle Aged; Neoplasm Proteins; Receptors, Retinoic Acid; Retinol-Binding Proteins; Retinol-Binding Proteins, Cellular; Tretinoin; Uterine Cervical Neoplasms

The epidermal growth factor receptor (EGF-R) gene is overexpressed or amplified in various human squamous cell carcinomas, including those of the head and neck (HNSCC). Earlier we found that beta-all-trans-retinoic acid (RA) inhibited the growth and suppressed the aberrant squamous cell differentiation of several cultured HNSCC cell lines. Here we examined the effects of RA on the expression and function of EGF-R in two HNSCC cell lines, 1483 and 183, which exhibit distinct states of squamous cell differentiation, EGF-R mRNA levels, and responses to the growth inhibitory effects of RA. Treatment with RA (1 microM, 7 days) of the RA-sensitive 1483 cells decreased the level of EGF-R mRNA two- to four-fold and the binding of 125I-EGF to the cell surface by 30%-35%. In contrast, RA treatment of the 183 cells did not alter the EGF-R mRNA level or the binding of 125I-EGF. Other effects of RA on EGF-R structure and function were similar in both cell lines. RA did not alter the amount of immunoprecipitable [35S]methionine-labeled cellular EGF-R, 125I-cell surface labeled EGF-R, EGF-R internalization, or transforming growth factor alpha (TGF-alpha) mRNA. More important, RA treatment of both cell lines decreased EGF-R autophosphorylation activity detected in immune-complex-kinase assay by about three- and five-fold in the 1483 and 183 cells, respectively. Likewise, RA decreased the glycosylation of EGF-R in both cell lines. In the 1483 cells, RA suppressed the incorporation of either glucosamine or fucose by about 50%, whereas in the 183 cells RA suppressed the incorporation of fucose by about 80%. These results demonstrate that RA can modify the structure of the EGF-R by decreasing its glycosylation and suggest that these changes may suppress the autophosphorylation activity of the receptor kinase. The RA-induced changes in EGF-R do not correlate with the effect of RA on the growth of the cells but may be related to the suppression of squamous cell differentiation in the 1483 cells.

Topics: Carcinoma, Squamous Cell; Cell Membrane; ErbB Receptors; Glycosylation; Head and Neck Neoplasms; Humans; Phosphorylation; RNA, Messenger; Tretinoin; Tumor Cells, Cultured

The A9 antigen is a basement membrane antigen of normal squamous epithelial cells that is strongly expressed in many squamous carcinomas. High expression of this antigen is associated with early relapse in squamous cell carcinomas of the head and neck. We now know that the A9 antigen is structurally, immunologically, and functionally similar to the alpha 6 beta 4 integrin that has been shown to be linked to metastatic behavior in murine tumor models. The alpha 6 and beta 4 genes have been cloned and sequenced, and a model has been constructed from the deduced amino acid composition. In this study we present a hypothetical model and use it to design experiments to assess the factors that influence the expression of the A9/alpha 6 beta 4 integrin in normal and malignant keratinocytes. High calcium induces down regulation of A9/alpha 6 beta 4 antigen in normal but not malignant keratinocytes within 24 hours. Although calcium can down-regulate beta 4 message in tumor cells in the absence of epidermal growth factor (EGF), transcription of beta 4 increased in the tumor cells under the conditions we used for assessing antigen expression (calcium plus EGF). Retinoic acid also stimulated transcription of beta 4 in tumor cells, but this was partially inhibited by the presence of high calcium. Phosphorylation of the beta 4 chain was stimulated by epidermal growth factor and calcium in normal keratinocytes, but in the malignant cells phosphorylation was constant regardless of the culture conditions. Our results indicate that high expression of the alpha 6 beta 4 integrin is associated with conditions that favor migration and undifferentiated proliferation of normal keratinocytes and that malignant keratinocytes differ from normal keratinocytes by constitutive phosphorylation of beta 4 and by failure to downregulate beta 4 transcription in response to calcium in the presence of EGF.

Topics: Antigens, Neoplasm; Blotting, Northern; Calcium; Carcinoma, Squamous Cell; Cell Division; Epidermal Growth Factor; Humans; Integrins; Keratinocytes; Models, Molecular; Mouth Neoplasms; Phosphorylation; Proteolipids; Pulmonary Surfactant-Associated Proteins; Pulmonary Surfactants; RNA, Messenger; Transcription, Genetic; Tretinoin; Tumor Cells, Cultured

Retinoic acid (RA) and epidermal growth factor (EGF) regulate growth and differentiation of epithelial cells. RA has both direct and indirect effects on gene expression. Direct effects result from modulation of the transcriptional activity of genes, which contain RA response elements (RARE) recognized by trans-acting nuclear RA receptors (RARs). A second indirect mechanism for the modulatory effects of RA is by the induction or repression of growth factors and growth factor receptors. There is evidence for functional interactions between RA and the EGF receptor (EGFR). RA enhances the proliferative response of cultured keratinocytes to EGF, increases the number of EGFRs on the surface of some cells, and induces EGFR promoter activity in most cells. In contrast, immunoprecipitation, Northern blot, and nuclear run-on analysis described in this paper show that RA suppresses EGFR synthesis at the transcriptional level in human epidermoid carcinoma ME180 cells. Deletion analysis of EGFR gene promoter mutants linked to the chloramphenicol acetyltransferase gene revealed the existence of a region of the promoter, -771 to -384, which is responsive to RA. Gel retardation data indicated that a cell-type nuclear protein which binds to this novel element is suppressed by RA in a dose-dependent manner. This decrease coincides with a decreased steady-state level of RAR-gamma mRNA. These data strongly suggest that the EGFR promoter is regulated by RAR-gamma, which itself is under the control of RA. Other cell-specific trans-acting factors may be involved in this regulation.

Topics: Carcinoma, Squamous Cell; Cell Differentiation; Down-Regulation; ErbB Receptors; Female; Humans; Promoter Regions, Genetic; Recombinant Fusion Proteins; Regulatory Sequences, Nucleic Acid; RNA, Messenger; Transcription, Genetic; Tretinoin; Tumor Cells, Cultured; Uterine Cervical Neoplasms

Cultured epidermoid oral carcinoma cells KB were easily detached from plastic surface in an ethylene diamine tetra acetic acid (EDTA) mediated detachment assay. Treatment of KB cells with retinol (vitamin A) or retinoic acid (RA) induced growth inhibition and caused reversible enhanced adhesion to the substratum in a similar fashion as well. Different synthetic retinoids were tested for their ability to induce growth inhibition and adhesion. A relationship between structure and activity of retinoids was found to exist. Possible mechanisms of retinoid-induced enhanced adhesion are discussed.

Topics: Carcinoma, Squamous Cell; Cell Adhesion; Cell Division; Culture Media; Humans; KB Cells; Kinetics; Mouth Neoplasms; Retinoids; Time Factors; Tretinoin; Tumor Cells, Cultured; Vitamin A

Treatment of the human esophageal cancer cell line EC8712 with retinoic acid (RA) stopped the cell growth significantly and gave rise to terminal differentiation of the cells characterized by increased expression of involucrin gene. Two cDNA libraries were constructed from the parental and RA-treated cells respectively. Repeated subtractive hybridization of single-stranded plasmid DNA prepared from pooled colonies of cDNA library of the parental cells with cDNA probe generated from the RA-treated cells exhausted sequences common to both libraries of the cell. The unhybridized cDNA probe represented, therefore, the genes activated after RA-treatment. By using these enriched cDNAs as probe to screen the cDNA library constructed from the RA-treated cells thirty-nine positive colonies were obtained, of which two were specifically due to RA-induction. One of these two cDNA clones, designated as pRA538, has undergone further analysis and shown differentiation-inducing effect on parental cancer cells. A novel strategy for cloning genes involved in terminal differentiation of cancer cells is developed.

Topics: Carcinoma, Squamous Cell; DNA Probes; DNA, Neoplasm; Esophageal Neoplasms; Gene Library; Genes, Tumor Suppressor; Humans; Tretinoin; Tumor Cells, Cultured

Antiproliferative effects of free retinoic acid (RA) and liposome-encapsulated RA (RAlp) were compared in a squamous carcinoma system using both monolayer cells and multicellular tumor spheroids (MTS), an in-vivo-like model with three-dimensional histological structure. Initial studies examined the effect of lipid composition on the efficiency of RA encapsulation and on the subsequent toxicity of RAlp to red blood cells. In 5-day growth assays for monolayer cells, RA and RAlp (1 microM-0.1 nM) produced similar growth inhibition. In 6-day growth assays for MTS, RAlp was shown to have increased effectiveness. Liposomal uptake by the squamous carcinoma cells was examined by culturing monolayers and MTS with fluorescence-tagged liposomes and examining them under fluorescence microscopy between days 1 and 6. Phagocytosed liposomes were present, but their low levels suggested that other mechanisms of drug delivery such as adsorption, fusion or direct lipid transfer probably occurred for RAlp. Histological examination of MTS showed that RA and RAlp produced similar alterations. In this squamous carcinoma system, liposomes are effective in delivering retinoic acid and in producing biological effects in monolayer cells and within the three-dimensional structure of MTS.

Topics: Carcinoma, Squamous Cell; Cell Division; Dose-Response Relationship, Drug; Drug Carriers; Erythrocytes; Humans; Liposomes; Tretinoin; Tumor Cells, Cultured

Retinoids (vitamin A analogues) inhibit the squamous differentiation of normal and malignant epithelial cells. This study investigated the ability of the head-and-neck squamous-cell carcinoma (HNSCC) cell line 1483 to undergo squamous differentiation in the absence and presence of beta-all-trans retinoic acid (RA). The growth of these cells in culture is accompanied by an increase in keratinocyte transglutaminase, involucrin and keratin KI, 3 established markers of squamous cell differentiation. Higher levels of these differentiation markers were detected in cells cultured in delipidized serum (DLS), from which endogenous retinoids have been extracted, than in cells cultured in fetal bovine serum (FBS), which contains retinoids. Treatment with I microM RA decreased the levels of the various differentiation markers in cells cultured in either FBS or DLS as revealed by immunofluorescent labelling of permeabilized cells and by immunoblotting of cell extracts using specific monoclonal or polyclonal antibodies. The cells' ability to cross-link proteins to form envelopes under the plasma membrane was stimulated in the presence of calcium ionophore but inhibited by RA. These results indicate that the malignant 1,483 HNSCC cells recapitulate the main characteristics of normal squamous-cell differentiation in culture and that RA suppresses this differentiation as it does in normal keratinizing epithelial cells.

Topics: Calcium; Carcinoma, Squamous Cell; Cell Differentiation; Fluorescent Antibody Technique; Head and Neck Neoplasms; Humans; Immunoblotting; Ionophores; Keratinocytes; Keratins; Neoplasm Proteins; Protein Precursors; Retinoids; Transglutaminases; Tretinoin; Tumor Cells, Cultured

Vitamin A and other retinoids profoundly inhibit morphological and biochemical features of epidermal differentiation in vivo and in vitro. To elucidate the molecular mechanisms underlying the differential expression of epidermal keratins and their regulation by retinoids, we examined retinoid-mediated changes in total protein expression, protein synthesis, mRNA expression, and transcription in cultured human keratinocytes and in squamous cell carcinoma (SCC-13) cells of epidermal origin. Our studies revealed that the epidermal keratins, K5, K6, K14, and K16, their mRNAs, and their transcripts were diminished relative to actin as a consequence of retinoic acid (RA) treatment. The effects were most pronounced in SCC-13 and were detected as early as 6 hr post-RA treatment, with enhancement over an additional 24-48 hr. Repression was also observed when 5' upstream sequences of K14 or K5 genes were used to drive expression of a chloramphenicol acetyltransferase reporter gene in SCC-13 keratinocytes. Both cell types were found to express mRNAs for the RA receptors alpha and gamma, which may be involved in the RA-mediated transcriptional changes in these cells. The rapid transcriptional changes in epidermal keratin genes were in striking contrast to the previously reported slow transcriptional changes in simple epithelial keratin genes.

Topics: Carcinoma, Squamous Cell; Carrier Proteins; Cell Line; Cells, Cultured; Chloramphenicol O-Acetyltransferase; Epidermis; Gene Expression Regulation; Humans; Infant, Newborn; Keratins; Male; Receptors, Retinoic Acid; RNA, Messenger; Transcription, Genetic; Transfection; Tretinoin

Using monoclonal antibody, G6K12, a novel differentiation marker of keratinocyte, we examined the effect of EGF and retinoic acid on the differentiation of SCC-25, a cell line established from human squamous cell carcinoma. EGF inhibited the expression of cell-surface differentiation marker in low cell-density, but not in high cell-density. Retinoic acid (more than 10(-8) M) inhibited the expression of the antigens. The terminal differentiation of SCC-25 cells occurred at the condition of high cell density. These results obtained demonstrate that EGF and retinoic acid inhibit the terminal differentiation of SCC-25 cells, and that the cell density is the important factor for the commitment of the terminal differentiation.

Topics: Carcinoma, Squamous Cell; Cell Differentiation; Depression, Chemical; Epidermal Growth Factor; Humans; Tretinoin; Tumor Cells, Cultured

Several studies have correlated the excessive production of prostaglandins (PGs) with tumor promotion and the suppression of the immune response. Inhibition of PGs by pharmacological agents has been demonstrated to enhance immunocompetence, and to suppress growth of tumors in animals and humans. In this study we examined the effect of retinol (I), all-trans-retinoic acid (II), N-(4-Hydroxyphenyl) retinamide (N-4-HPR) (III), canthaxanthin (CTX) (IV), and beta-carotene (beta-CT) (V) on the bioconversion of 14C-arachidonic acid (AA) to PGE2 by squamous carcinoma cells of the tongue, SCC-25. Agents (I), (II), (III), (IV) inhibited while (V) stimulated PGE2 formation in a dose related manner. N-4-HPR was the most potent inhibitor of PGE2 synthesis. The data suggest that certain retinoids and carotenoids have the potential of inhibition of PG synthesis by oral squamous carcinoma cells. Inhibitory effects such as those described here and antioxidant properties might in part contribute to the antiinflammatory and anticarcinogenic activity of retinoids in vivo.

Topics: beta Carotene; Canthaxanthin; Carcinoma, Squamous Cell; Carotenoids; Chromatography, Thin Layer; Fenretinide; Humans; Indomethacin; Prostaglandins; Retinoids; Tongue Neoplasms; Tretinoin; Tumor Cells, Cultured; Vitamin A

In the epidermis of skin, a fine balance exists between proliferating progenitor cells and terminally differentiating cells. We examined the effects of TGF-beta s and retinoic acid (RA) on controlling this balance in normal and malignant human epidermal keratinocytes cultured under conditions where most morphological and biochemical features of epidermis in vivo are retained. Our results revealed marked and pleiotropic effects of both TGF-beta and RA on keratinocytes. In contrast to retinoids, TGF-beta s acted on mitotically active basal cells to retard cell proliferation. Although withdrawal from the cell cycle is a necessary prerequisite for commitment to terminal differentiation, TGF-beta s inhibited normal keratinization in suprabasal cells and promoted the type of differentiation commonly associated with wound-healing and epidermal hyperproliferation. The actions of TGF-beta s and RA on normal keratinization were synergistic, whereas those on abnormal differentiation associated with hyperproliferation were antagonistic. These observations underscore the notion that environmental changes can act separately on proliferating and differentiating cells within the population. Under the conditions used here, the action of TGF-beta s on human keratinocytes was dominant over RA, and TGF-beta s did not seem to be induced as a consequence of RA treatment. This finding is consistent with the fact that RA accelerated, rather than inhibited, proliferation in raft cultures. Collectively, our data suggest that the effects of both factors on epidermal growth and differentiation are multifaceted and the extent to which their action is coupled in keratinocytes may vary under different conditions and/or in different species.

Topics: Carcinoma, Squamous Cell; Cell Differentiation; Cell Division; Cell Line; Cells, Cultured; DNA Replication; Epidermal Cells; Humans; Keratinocytes; Keratins; Molecular Weight; Skin Neoplasms; Transforming Growth Factor beta; Tretinoin

Vitamin A and some of its metabolites such as beta-all-trans retinoic acid (RA) have been implicated in the regulation of differentiation of normal and malignant epithelial cells in vivo and in vitro. In the present study the effects of RA on the growth and differentiation of 7 cell lines derived from human head and neck squamous-cell carcinomas (HNSCCs) were examined. RA (greater than 0.01 microM) inhibited the proliferation in monolayer culture of 6 of 7 HNSCC cell lines. One cell line (UMSCC-35) was very sensitive, 5 (UMSCC-10A, -19, -30, -22B and HNSCC 1483) were moderately sensitive, and 1 (HNSCC 183) was insensitive. Three of the cell lines (UMSCC-22B, -30, and HNSCC 1483) were capable of forming colonies in semisolid medium--a capability that was suppressed by RA. The HNSCC cell lines expressed various levels of the squamous-cell differentiation markers type I (particulate, epidermal) transglutaminase (TGase) and cholesterol sulfate (CS). RA treatment (I microM, 6 days) decreased TGase activity by more than 50% in 3 (UMSCC-10A, -22B and 1483) of the 7 cell lines, and the effect on UMSCC-22B was dose-dependent. Type II TGase (soluble, tissue type) activity was detected in 3 cell lines, and after RA treatment its activity increased in HNSCC 1483 and 183 cells and decreased in UMSCC-19. Following RA treatment, CS levels decreased by 20, 25, 70, 76, 89 and 91% in cell lines UMSCC-30, -10A, 183, UMSCC-35, -22B, and HNSCC 1483, respectively. The suppression by RA of CS accumulation in the 1483 cells was dose-dependent. Cholesterol sulfotransferase activity, which is responsible for CS synthesis, was suppressed by 40-97% after RA treatment of UMSCC-19, -22B, and HNSCC 1483. Our results demonstrate that RA inhibits the growth and decreases the level of 2 squamous differentiation markers in HNSCC cells.

Topics: Carcinoma, Squamous Cell; Cell Line; Cell Transformation, Neoplastic; Cholesterol Esters; Depression, Chemical; Dose-Response Relationship, Drug; Head and Neck Neoplasms; Humans; Mouth Neoplasms; Sulfotransferases; Transglutaminases; Tretinoin; Tumor Cells, Cultured

Topics: Carcinoma, Squamous Cell; Cell Adhesion; Cell Division; Cell Line; Culture Techniques; Head and Neck Neoplasms; Humans; Retinoids; Tretinoin; Tumor Cells, Cultured

The aim of this study was to evaluate the effect of four natural and synthetic retinoids: Ro 12-7310 (I), Ro 13-7410 (II), 13-cis-retinoic acid (III), and Ro 13-7652 (IV) on the synthesis of PGE2 in human squamous cell carcinoma (SCC) of the tongue (SCC-25). 5 X 10(6) cells were plated and labeled with 0.2 microCi of (14C)-arachidonic acid (AA) in 2 ml of DMEM/F12 containing 0.1% BSA for 4 h. The cells were then washed, and incubated in serum-free medium with the retinoids (10,20,30,40 microM) for 1 h. The cells were further stimulated with melittin an additional hour. Radioactive metabolites released in media were then extracted with diethyl ether. The ether extracts were separated by TLC and radioactive PGE2 zone was quantitated by means of liquid scintillation counting. The rank order of percent inhibition of PGE2 synthesis by retinoids at four concentration levels was (I) greater than (II) greater than (III) greater than (IV). Since inhibition of PG production has been demonstrated to suppress growth of tumors in animal models and humans, further study on the effect of retinoids on growth of SCC in vitro as well as in vivo seems warranted.

Topics: Acitretin; Arachidonic Acid; Arachidonic Acids; Benzoates; Carcinoma, Squamous Cell; Dinoprostone; Dose-Response Relationship, Drug; Etretinate; Humans; Prostaglandin-Endoperoxide Synthases; Retinoids; Tongue Neoplasms; Tretinoin; Tumor Cells, Cultured

Retinoic acid (RA) increases epidermal growth factor (EGF) receptors in many cells; in ME180 cells, a human epidermoid carcinoma, RA resulted in a dose- and time-dependent reduction of EGF binding. In RA-treated ME180 cells, binding was 41% of the control. The reduction of EGF binding was due to a decrease in the number of receptors, from 8.7 x 10(4) to 3.6 x 10(4) per cell. The difference was present 8 h after the addition of RA and was reversible 3 days after its removal. Scatchard analysis indicated that RA did not change the binding affinity of EGF (Kd = 1 nM). Also, RA did not alter the rate of EGF internalization or the down-regulation induced by exogenous EGF. Flow-cytometric analysis revealed that RA did not alter the cell cycle. Soluble cell membrane extracts were prepared in a Tris buffer with protease inhibitors, immunoprecipitated, electrophoresed, and immunoblotted with an antiserum to EGF receptors. The EGF receptor band of Mr 170,000 was decreased in RA-treated cells. These results suggest that RA reduces the synthesis of EGF receptors in ME180 cells.

Topics: Carcinoma, Squamous Cell; Cell Division; Down-Regulation; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Time Factors; Tretinoin; Tumor Cells, Cultured; Uterine Cervical Neoplasms

The growth of multicellular tumor spheroids, MTSs, from squamous carcinoma line MDA 886Ln was inhibited by beta-all-trans retinoic acid (RA). Inhibition occurred within 3 to 5 days of treatment, and MTS size then remained static for up to 2 weeks. Although their growth stopped, 10-day-treated MTSs incorporated [3H]thymidine into trichloroacetic acid-precipitable material, and the [3H]thymidine labeling index, determined by autoradiography, was equivalent between control and RA-treated MTSs. Bivariate flow cytometric analysis of bromodeoxyuridine-labeled MTSs showed equivalent S phase progression of labeled cells over an 8-hour chase. MTS growth stasis was not related to RA-induced cell cycle effects. Monitoring of MTSs for cell sloughing showed no significant cell shedding that could account for stasis. Quantitation of cell number and DNA content per MTS showed an RA-induced decrease. This was confirmed by histological analysis, which demonstrated the temporal appearance of acellular areas. MTS growth statis is thus related to an RA-induced cell loss in this MTS model for squamous carcinomas.

Topics: Autoradiography; Carcinoma, Squamous Cell; Cell Division; Cell Line; Cell Survival; DNA Replication; Humans; Kinetics; Thymidine; Tretinoin; Tritium; Tumor Cells, Cultured

Exploiting the sensitivity of neoplastic keratinocytes to physiological effectors, this work analyzes the degree of coordination among differentiation markers in the established human epidermal squamous carcinoma cell line SCC-13 in comparison to normal human epidermal cells. This analysis showed that overall keratin content was modulated substantially and in parallel with particulate transglutaminase activity in response to variation of calcium, retinoic acid, and hydrocortisone concentrations in the medium. The changes in keratin expression were evident primarily in the striking stimulation by hydrocortisone or calcium and the virtual suppression by retinoic acid of species in the 56-58 kd region, which have not previously been reported subject to such physiological modulation. In contrast, involucrin levels were coordinated only to a limited degree with particulate transglutaminase activity and keratin content. The very low involucrin levels observed in low calcium medium were increased 5- to 10-fold in high calcium medium. However, they were also increased 5- to 30-fold in low calcium medium by retinoic acid, a clear example of uncoupling. Activities of the tissue transglutaminase were altered considerably by the various culture conditions but were not obviously coordinated to keratinocyte markers. In normal epidermal cells, the suppressive effect of retinoic acid was much more evident with particulate transglutaminase than involucrin levels. While calcium had a large stimulatory effect on both markers, hydrocortisone had little or no influence. These results emphasize the potential importance of quantitative analysis of differentiation markers for resolving the contribution of physiological elements in coordination of cellular programming.

Topics: Calcium; Carcinoma, Squamous Cell; Cell Differentiation; Cell Line; Epidermal Cells; Humans; Hydrocortisone; Keratins; Protein Precursors; Transglutaminases; Tretinoin

When cells from normal human epidermis and from the human squamous cell carcinoma line SCC-13 were seeded on floating rafts of collagen and fibroblasts, they stratified and underwent terminal differentiation. Although the program of differentiation in SCC-13 cells was morphologically abnormal, the cultures resembled normal epidermal raft cultures by expressing the terminal differentiation-specific keratins, K1/K10, and by restricting their proliferative capacity to the basal-like cells of the population. In addition, the differentiating cells of both normal and SCC-13 raft cultures expressed keratins K6 and K16, which are not normally expressed in epidermis, but are synthesized suprabasally during wound-healing and in various epidermal diseases associated with hyperproliferation. While the behavior of normal and SCC-13 rafts was quite similar when they were cultured over normal medium, significant biochemical differences began to emerge when the cultures were exposed to retinoic acid. Most notably, while the SCC-13 cultures still stratified extensively, they showed a marked inhibition of both abnormal (K6/K16) and normal (K1/K10) differentiation-associated keratins, concomitantly with an overall disappearance of differentiated phenotype. Surprisingly, the reduction in K6/K16 in retinoid-treated SCC-13 cultures was not accompanied by a decrease in cell proliferation. Using immunohistochemistry combined with [3H]thymidine labeling, we demonstrate that while the expression of K6 and K16 are often associated with hyperproliferation, these keratins are only produced in the nondividing, differentiating populations of proliferating cultures. Moreover, since their expression can be suppressed without a corresponding decrease in proliferation, the expression of these keratins cannot be essential to the nature of the hyperproliferative epidermal cell.

Topics: Blotting, Northern; Carcinoma, Squamous Cell; Cell Division; DNA; Electrophoresis, Gel, Two-Dimensional; Epidermal Cells; Epidermis; Gene Expression Regulation; Humans; Hyperplasia; Keratins; Molecular Weight; Skin Diseases; Tretinoin; Tumor Cells, Cultured

Cell line MDA 886Ln was established from a laryngeal lymph node metastasis. When grown as a multicellular tumor spheroid (MTS), it exhibits squamous differentiation. We studied the effects of beta-all-trans retinoic acid (RA) on the growth, differentiation and glycoprotein content of this MTS model for squamous carcinomas of the head and neck. The growth of MTSs was inhibited in a dose-dependent manner by 10(-6) to 10(-10) M RA. Growth inhibition occurred between 3 and 5 days of RA treatment (10(-6)M). Immunohistochemical and electrophoretic analyses revealed that RA suppressed the morphological markers of squamous differentiation (squames), involucrin expression, and keratin expression. Gly-coprotein expression was examined by metabolic labelling using 3H-glucosamine, in situ labelling of polyacrylamide gels with 125I-labelled wheat-germ agglutinin (WGA), localization of fluorescein isothionate-WGA in frozen sections, and determination of sialyltransferase activity. Treatment using 10(-6) M RA altered glycoprotein expression both biochemically and morphologically, and WGA was shown to bind preferentially to sialic acid residues. The sensitivity of this MTS model to RA treatment and its ability to be analyzed through morphological, immunohistochemical and biochemical techniques suggest that it will prove useful in studying the relationships between growth, differentiation and RA-induced alterations in squamous carcinomas.

Topics: Carcinoma, Squamous Cell; Cell Differentiation; Cell Division; Glycoproteins; Head and Neck Neoplasms; Humans; Keratins; Male; Molecular Weight; Neoplasm Proteins; Organoids; Protein Precursors; Tretinoin; Tumor Cells, Cultured

SqCC/Y1, a human malignant squamous cell carcinoma, spontaneously differentiates when grown to confluence in delipidized serum-containing medium, as measured by the capacity to form detergent-insoluble cornified cell envelopes. Thus, 30% of SqCC/Y1 cells spontaneously attained the differentiated state after 6 days in culture. Exposure of SqCC/Y1 cells to 30, 100, or 300 nM hydrocortisone increased the number of mature cells, producing a 25, 100, and 225%, respective, increase in the number of differentiated cells over the spontaneous rate of maturation. Retinoic acid at levels of 3-300 nM was inhibitory, causing a 24-85% decrease in the number of differentiated cells. Simultaneous treatment with hydrocortisone and retinoic acid indicated mutual antagonism of the effects of these agents on the formation of cornified envelopes. Since hydrocortisone possesses antiangiogenic (AG), mineralocorticoid (MC) and glucocorticoid (GC) activities, steroids with different degrees of GC, MC, and AG potency were examined for their capacities to induce terminal differentiation. Only steroids with GC activity, such as dexamethasone, hydrocortisone, and RU-28362, were capable of increasing the degree of SqCC/Y1 differentiation and antagonizing the inhibitory effects of retinoic acid on the maturation process. In addition, the GC antagonist, RU-38486, reversed the stimulation of cellular differentiation produced by the glucocorticoids. The findings indicate that GC activity is required for the steroid-induced terminal differentiation of SqCC/Y1 cells.

Topics: 17-alpha-Hydroxyprogesterone; Androstanols; Carcinoma, Squamous Cell; Cell Differentiation; Desoxycorticosterone; Dose-Response Relationship, Drug; Glucocorticoids; Humans; Hydrocortisone; Hydroxyprogesterones; In Vitro Techniques; Mifepristone; Mineralocorticoids; Neovascularization, Pathologic; Progesterone; Tretinoin; Tumor Cells, Cultured

Tumorigenesis requires accelerated polyamine biosynthesis, and elevated levels of ornithine decarboxylase, the rate-limiting enzyme in this reaction chain. The primary goal of this study was to determine whether induction of oral cavity carcinoma by dimethylbenzanthracene was accompanied by increased ornithine decarboxylase. It has previously been demonstrated in an oral carcinogenesis model that cotreatment with vitamins A or E delayed tumor development. The second goal of this study was to determine whether this chemoprotective effect was associated with a decrease in ornithine decarboxylase activity. We found that dimethylbenzanthracene did stimulate ornithine decarboxylase. Vitamins A and E alone also stimulate ornithine decarboxylase, and this effect is additive with dimethylbenzanthracene. Use of both vitamins together prevents the additive effect of either, alone, and vitamin A inhibits the late-phase ornithine decarboxylase response to dimethylbenzanthracene in all animals. We conclude that pretreatment with vitamins A, or A and E together protects against the carcinogenic action of dimethylbenzanthracene, and that the mechanism of this protection is early truncation of the ornithine decarboxylase response to dimethylbenzanthracene.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinoma, Squamous Cell; Cheek; Cricetinae; Male; Mesocricetus; Mouth Neoplasms; Ornithine Decarboxylase Inhibitors; Premedication; Tretinoin; Vitamin A; Vitamin E

The present study reports light and electron microscopic observations of hamster cheek pouch epithelium exposed to 25 micrograms DMBA (DMBA = 9,10 Dimethyl, 1,2 Benz(a)-nthracene, RA = Retinoic Acid) and 25 micrograms DMBA along with 25 micrograms, 50 micrograms and 100 micrograms retinoic acid. Significant delay in tumour induction was observed in the animals treated with DMBA + retinoic acid. DMBA + retinoic acid treated cheek pouch developed papillary epidermoid carcinomas which were less invasive and less keratinized than only DMBA treated animals. At cellular level DMBA treated animals showed keratinized cells with thick bundles of tonofilaments, broken basement membrane, wide intercellular spaces and loss of desmosomal attachments, whereas animals treated with DMBA + retinoic acid showed decrease in the intercellular spaces, maintenance of basement membrane and intracellular organelles with suppression of keratinization, indicating the differentiating effect of retinoic acid on DMBA transformed cells of hamster cheek pouch.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinoma, Papillary; Carcinoma, Squamous Cell; Cell Nucleus; Cell Transformation, Neoplastic; Cheek; Cricetinae; Cytoplasm; Epithelium; Female; Male; Mesocricetus; Microscopy, Electron; Mouth Mucosa; Mouth Neoplasms; Neoplasm Invasiveness; Tretinoin

Evidence from several in vitro systems indicates that cellular responses to DNA topoisomerase II-reactive compounds (i.e., the epipodophyllotoxins and intercalating agents) may be affected by the relative rate of proliferation. Using a human head and neck squamous carcinoma cell line 183A, we have investigated the effect of beta-all-trans-retinoic acid (RA), a substance with known antiproliferative effects, on the DNA cleavage and cytotoxic activities of etoposide and 4'-(acridinylamino)methanesulfon-m-anisidide which interact with topoisomerase II. The effect of RA treatment on the activity of X-radiation and bleomycin, both of which produce free radical mediated effects, was also examined. RA treatment (10 to 20 microM for 72 h) does not significantly influence DNA cleavage induced by X-radiation or bleomycin but decreases DNA cleavage and cytotoxicity mediated by etoposide and 4'-(acridinylamino)methanesulfon-m-anisidide. Further, this effect can be demonstrated at a dose of RA that is minimally growth inhibitory. The inhibitory effect of RA appears to be localized to the nucleus given that similar effects on drug-mediated DNA cleavage can be demonstrated in nuclei isolated from RA-treated cells. However, both drug-stimulated DNA cleavage activity and topoisomerase II catalytic activity are approximately equal in crude nuclear extracts of untreated and RA-treated cells. These data suggest that the resistance to topoisomerase II-reactive drugs induced by RA treatment of 183A cells is not mediated through a direct effect on the enzyme, but, instead, is related to other changes in the nuclear milieu occurring in the initial stages of quiescence such as altered chromatin conformation.

Topics: Amsacrine; Carcinoma, Squamous Cell; Cell Survival; DNA Damage; DNA Topoisomerases, Type II; Etoposide; Head and Neck Neoplasms; Humans; Tretinoin; Tumor Cells, Cultured

To confirm reports that skin cancer can be prevented with retinoid treatment, a three-year controlled prospective study was conducted of oral isotretinoin in five patients with xeroderma pigmentosum who had a history of multiple cutaneous basal cell or squamous cell carcinomas. Patients were treated with isotretinoin, 2 mg/kg per day for two years, and then evaluated for an additional year without using the drug. Before, during, and after treatment, biopsy specimens of all suspicious lesions were examined, and skin cancers were removed surgically. The patients had a total of 121 tumors in the two years before treatment. During two years of treatment with isotretinoin, there were twenty-five tumors, with an average reduction in skin cancers of 63 percent (p = 0.019). After use of the drug was discontinued, the tumor frequency increased a mean of 8.5 times over the frequency during treatment (p = 0.007). Although all patients experienced mucocutaneous toxic effects, and abnormalities in triglyceride levels, results of liver function tests, or skeletal findings occurred in some, high-dosage oral isotretinoin was effective in the chemoprophylaxis of skin cancers in patients with xeroderma pigmentosum.

Topics: Administration, Oral; Adolescent; Adult; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Child; Female; Follow-Up Studies; Humans; Male; Prospective Studies; Skin Neoplasms; Tretinoin; Xeroderma Pigmentosum

Differentiation of SqCC/Y1, a human malignant squamous carcinoma, can be modulated by the presence of both corticosteroids and retinoids. To evaluate the regulation of the differentiation of epidermal cells by these agents, we have employed delipidized serum from which glucocorticoids and retinoids were removed. Thirty percent of SqCC/Y1 cells spontaneously expressed the terminally differentiated phenotype after 6 d in culture, as measured by the capacity to form detergent-insoluble cornified envelopes. Exposure of SqCC/Y1 cells to hydrocortisone at concentrations of 30, 100 and 300 nM produced a 25, 100, and 175%, increase, respectively, in the number of differentiated cells over untreated control cultures. Exposure of cells to retinoic acid at levels of from 3 to 300 nM caused a 24 to 85% decrease in the quantity of differentiated cells. Simultaneous treatment of SqCC/Y1 cells with hydrocortisone and retinoic acid resulted in mutual antagonism of cornified envelope formation. Treatment of SqCC/Y1 cells with a 1000-fold molar excess of retinoic acid did not directly alter the uptake of hydrocortisone, and a 100-fold molar excess did not directly inhibit the binding of the corticosteroid to its receptor. Pretreatment of cells for 48, 72, or 96 h with 100 nM retinoic acid decreased the binding of hydrocortisone to its receptor by only 20%, and only resulted in a small decrease in the total amount of hydrocortisone associated with cells 48 h after the addition of retinoic acid. These findings suggest that the antagonism between hydrocortisone and retinoic acid on the terminal differentiation of SqCC/Y1 is not expressed at the level of the corticosteroid receptor.

Topics: Carcinoma, Squamous Cell; Cell Differentiation; Dexamethasone; Humans; Hydrocortisone; Receptors, Glucocorticoid; Tretinoin; Tumor Cells, Cultured

Physiologic concentrations of retinoic acid strongly inhibit the in vitro maturation of human squamous carcinoma cells in serum-free medium. Differentiation, as measured by the capacity to synthesize cornified cell envelopes, could be induced by hydrocortisone in retinoic acid-treated SqCC/Y1 and CE-81T cells. However, two other cell lines (C4-1 and A431) were less competent to spontaneously form cornified cell envelopes and resistant to the induction of envelope competence by hydrocortisone in the presence of retinoic acid. To investigate the mechanism underlying the resistance of these two lines to hydrocortisone, the characteristics of glucocorticoid receptors were analyzed. Whole cell dexamethasone binding sites ranged from 1300 to 9000 sites per cell for the four cell lines. The binding affinity for dexamethasone was similar in all four squamous carcinoma cell lines (1.32 to 4.75 nM). During retinoic acid-treatment, the binding of dexamethasone by intact SqCC/Y1 and CE-81T cells increased 1.5- to 3.0-fold over 48 h. In contrast, the number of dexamethasone binding sites were decreased by 80% in retinoic acid-treated A431 and C4-1 cells. In each case, the regulation of dexamethasone binding was dependent on the concentration of retinoic acid, with maximal effects being observed at 10(-6) M. Thus, the manner in which retinoic acid regulates the availability of dexamethasone binding sites might explain, in part, the effects of glucocorticoids on differentiation of retinoic acid-treated squamous carcinoma cell lines.

Topics: Carcinoma, Squamous Cell; Cell Differentiation; Cell Division; Cell Line; Humans; Hydrocortisone; Keratins; Kinetics; Receptors, Glucocorticoid; Tretinoin; Tumor Cells, Cultured

Retinoic acid and retinyl acetate induce tissue transglutaminase to high levels in cultured SCC-4 keratinocytes, increasing the enzyme specific activity over 50-fold under optimal conditions. Pretreatment of the cells for a day with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3-methylcholanthrene (3-MC) or benzo[a]pyrene almost completely prevented the induction observed upon subsequent treatment with retinoic acid for 2 days. Similar aromatic compounds that do not induce aryl hydrocarbon hydroxylase (pyrene, dibenzofuran) did not exhibit this suppressive effect. The concentration dependence on TCDD for induction of aryl hydrocarbon hydroxylase was nearly identical to that for its suppression of transglutaminase induction, with half-maximal effects observed at approximately 20 pM in each instance. Similarly, the concentrations of 3-MC giving half-maximal stimulation of the hydroxylase and suppression of the transglutaminase were comparable (0.9 and 0.3 microM, respectively), although this agent was almost five orders of magnitude less potent than TCDD. These observations reveal a loss of cellular sensitivity to vitamin A mediated by the Ah receptor.

Topics: Carcinoma, Squamous Cell; Cell Line; Dioxins; Diterpenes; Enzyme Induction; Humans; Kinetics; Polychlorinated Dibenzodioxins; Polycyclic Compounds; Retinyl Esters; Tetradecanoylphorbol Acetate; Transglutaminases; Tretinoin; Vitamin A

Regression of established hamster buccal pouch carcinoma has recently been demonstrated in association with an induction of tumor necrosis factor alpha in macrophages. Regression of hamster buccal pouch tumors has also been demonstrated following the local injection of alphatocopherol, canthaxanthin and an extract of Spirulina-Dunaliella algae. The current study demonstrates that cancer regression is also accompanied by a significant induction of tumor necrosis factor in macrophages in the tumor area, suggesting a possible mechanism of tumor destruction. One hundred and forty young, male adult hamsters were divided into seven equal groups of 20 animals. Epidermoid carcinomas were induced in right buccal pouches by 14 weeks of painting, three times per week, of a 0.5% solution of 7,12-dimethylbenz(a)anthracene. Groups 1 and 2 were untreated and sham injected controls. Groups 3-7 had injected twice weekly into the right buccal pouches 0.1 ml (1.9 mg/ml of 13-cis-retinoic acid, canthaxanthin, algae extract, beta-carotene and alphatocopherol. After 4 weeks the tumors in groups 3-7 demonstrated varying degrees of regression and the animals were sacrificed and the right buccal pouches excised. Tumor necrosis factor alpha (TNF-alpha) was demonstrated by immunohistochemical techniques. A very significant increase in TNF-alpha positive macrophages was found in the tumor-bearing pouches of animals in groups 5-7. Smaller numbers of TNF-alpha-positive macrophages were found in group 4 pouches and a very slight increase in group 3 pouches.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Canthaxanthin; Carcinoma, Squamous Cell; Carotenoids; Cheek; Cricetinae; Eukaryota; Macrophages; Male; Mesocricetus; Mouth Neoplasms; Tretinoin; Tumor Necrosis Factor-alpha; Vitamin E

Murine squamous carcinoma cells (KLN205) grown in a medium supplemented with the retinoid, 13-cis retinoic acid (RA), had dose-dependent, selective increases in the expression of certain lectin receptors, which correlated with a dramatic decrease in the ability to form pulmonary colonies (P = .0003) (Couch MJ, Pauli BU, Weinstein RS, Coon JS: JNCI, 78:971-977, 1987). These findings suggest a possible relationship between the RA-induced glycoconjugate alterations and the decreased experimental metastatic behavior. We further define the mechanism of RA's action. The finding that RA treatment (5 X 10(-6) M, 5 X 10(-7) M) did not perturb the cell cycle of KLN205 cells provides further proof that the decreased metastatic behavior is not attributable to any inhibition in the rate of growth or to alterations in the cell cycle. Furthermore, since stable subpopulations with variable lectin binding could not be detected, the mechanism of RA's action does not appear to be due to selection of variant tumor-cell subpopulations. Finally, in a series of experiments designed to determine the reversibility of the RA treatment, the RA-induced decrease in metastatic behavior reverted back to a more metastatic state in the same time frame (3 days) as the reversion of the RA-induced changes in cell-surface glycoconjugate expression. This reversion provides further evidence for a close relationship between the RA-induced modulation of tumor cell-surface glycoconjugate expression and the decreased metastatic behavior; it suggests that transient, reversible modulation of the tumor cell surface may play a role in determining metastatic behavior.

Topics: Animals; Carcinoma, Squamous Cell; Cell Cycle; Flow Cytometry; Glycoconjugates; Isotretinoin; Lectins; Lung Neoplasms; Male; Mice; Neoplasm Metastasis; Receptors, Mitogen; Tretinoin; Tumor Cells, Cultured

SqCC/Y1 cells grow as a monolayer in culture and differentiate when maintained in the plateau phase; in the absence of serum these cells differentiate more rapidly. The differentiation is characterized by the stratification of the culture to form a structure consisting of several cellular layers, synthesis of specific keratins, and the attainment of the capacity to form a cornified cell membrane. The stratification process is indicative of the importance of cell-cell interactions during maturation. To study the relationship between membrane glycosphingolipids (GSLs) and the state of differentiation of SqCC/Y1 cells, GSLs were measured in cultures grown in the presence or absence of fetal calf serum. Glycolipids were isolated by diethylaminoethyl-Sephadex and Iatrobeads column chromatographies, and their distributions were determined by high-performance thin-layer chromatography. GM3 was the major ganglioside present in these cells. Other ganglioside components were tentatively identified as GM2, GM1, and GD3. Differences in ganglioside patterns were observed in differentiated cultures; the major changes were accumulation of GD3 and depletion of GM1. The predominant neutral GSLs in SqCC/Y1 cells were identified as Glc beta 1-1Cer, Gal beta 1-4Glc beta 1-1Cer, Gal beta 1-4Gal alpha 1-4Glc beta 1-1Cer, Gal NAc beta 1-3Gal alpha 1-4Gal beta 1-4Glc beta 1-1Cer, and three unknown complex GSLs. Differentiated cultures, however, showed variations in banding patterns, which include an increase in Glc beta 1-1Cer and Gal beta 1-4Glc beta 1-1Cer and a decrease in Gal alpha 1-4Gal beta 1-4Glc beta 1-1Cer and Gal NAc beta 1-3Gal alpha 1-4Gal beta 1-4Glc beta-1Cer. These changes, however, were not observed when the cells were grown in the presence of epidermal growth factor or retinoic acid, factors which inhibit the differentiation process. The findings demonstrate significant changes in glycolipid composition of differentiated SqCC/Y1 cells grown in the absence of serum, suggesting that these lipids may be important to the differentiated state.

Topics: Carcinoma, Squamous Cell; Cell Differentiation; Epidermal Growth Factor; Fatty Acids; Glycosphingolipids; Humans; Tretinoin; Tumor Cells, Cultured

The effects of butyrate and retinoic acid in combination with catecholamines or histamine on the HN-1 human head and neck squamous carcinoma cell line were investigated analysing cell proliferation, placental alkaline phosphatase (PLAP) activity, and relative cytokeratin content. Butyrate inhibited cell proliferation in agar, whereas retinoic acid induced a small inhibitory effect. Butyrate enhanced PLAP activity in a time related manner in contrast to retinoic acid, which had no significant effect. However, retinoic acid inhibited the efficacy of butyrate to induce PLAP activity. A synergistic enhancement of PLAP activity was demonstrated after treatment of butyrate pretreated cells with catecholamines or histamine. The beta-adrenergic antagonist propranolol partly inhibited the aforementioned enhancement of PLAP activity, whereas the alpha-adrenergic antagonist phentolamine further enhanced PLAP activity. Indirect labeling of keratins with a polyclonal antibody showed that cytokeratin content was enhanced by butyrate but not by retinoic acid. Further analysis of cytokeratin content using four monoclonal antibodies showed that labeling of cytokeratins (5 + 8) was increased by butyrate. PLAP activity could be modulated by a concerted action of either butyrate plus retinoic acid or butyrate plus catecholamines or histamine, indicating a possible role for PLAP in tumour cell proliferation.

Topics: Alkaline Phosphatase; Butyrates; Butyric Acid; Carcinoma, Squamous Cell; Catecholamines; Cell Division; Cell Line; DNA; Flow Cytometry; GPI-Linked Proteins; Head and Neck Neoplasms; Histamine; Humans; Isoenzymes; Keratins; Phentolamine; Placenta; Propranolol; Tretinoin

The modulation of clonal growth of cells of 15 human lung cancer lines was examined by coculture with different recombinant lymphokines, monokines, and several agents which induce differentiation in other malignant cell systems. Recombinant human tumor necrosis factor alpha (TNF) was inhibitory to all non-small cell lung cancer cell lines with a 50% effective dose of clonal inhibition (ED50) in the range of 30-2000 units/ml. Two representative squamous lines (SK-MES and P3) had 150 to 250 high affinity (Kd approximately equal to pM) cell surface TNF receptors. In contrast, clonal growth of small cell lung cancer lines was not inhibited by TNF, and two representative lines (H69c and R592) expressed negligible cell surface TNF receptors. Recombinant alpha, beta, and gamma interferons (4000 units/ml) each inhibited greater than or equal to 30% clonal growth of more than 50% of the non-small cell lung cancer lines. TNF (100-1000 units/ml) in combination with gamma-interferon was synergistic in the inhibition of clonal growth of these cells. Further studies showed that synergism of clonal inhibition occurred even when the cells were initially exposed to gamma-interferon, washed, and plated in soft agar with TNF. All-trans-retinoic acid (ED50, 5 X 10(-7)-10(-6) M), dimethyl sulfoxide (ED50, 1.2-1.6%), and 12-O-tetradecanoylphorbol-13-acetate (ED50, 5 X 10(-8)-10(-10) M) inhibited clonal proliferation of 7 of 9, 7 of 9, and 8 of 9 non-small cell lung cancer lines, respectively. In contrast, clonal proliferation of cells of small cell lung cancer lines was decreased only slightly at almost all concentrations of each of the agents. Interleukin-1 and -2 and granulocyte-monocyte colony-stimulating factor had no effect on the clonal growth of any of the lung cancer lines. Our results suggest that TNF in combination with gamma-interferon may be therapeutically active for some patients with non-small cell lung cancer, but small cell lung cancer probably will be unresponsive to all the agents that we examined.

Topics: Calcitriol; Carcinoma, Non-Small-Cell Lung; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Cell Division; Cell Line; Clone Cells; Colony-Stimulating Factors; Dimethyl Sulfoxide; Drug Synergism; Humans; Interleukin-1; Lung Neoplasms; Lymphokines; Monokines; Proteins; Receptors, Cell Surface; Receptors, Tumor Necrosis Factor; Recombinant Proteins; Tetradecanoylphorbol Acetate; Tretinoin; Tumor Stem Cell Assay

The effect of algae extract on tumor regression was studied. Phycotene (extract of Spirulina and Dunaliella algae) 250 micrograms in 0.1 ml MEM (minimum essential medium) was injected locally into DMBA (7, 12 dimethylbenz(a)anthracene)-induced squamous cell carcinomas of hamster buccal pouch in 20 animals. DMBA-induced carcinomas in 20 hamsters were injected locally with beta carotene 250 micrograms in 0.1 ml MEM; DMBA-induced carcinomas in 20 animals were injected locally with canthaxanthin, 250 micrograms in 0.1 ml MEM, and DMBA-induced carcinomas in 20 animals were injected locally with 13-cis-retinoic acid, 250 micrograms in 0.1 ml MEM. Twenty animals with DMBA-induced carcinomas were sham-injected controls using 0.1 ml MEM. The various agents were injected into the tumor bearing right buccal pouches twice-weekly for four weeks. Total tumor regression was found in 30% of phycotene animals, 20% of beta carotene animals and 15% of canthaxanthin animals after four weeks. Partial tumor regression was found in the remaining 70% of phycotene animals, 80% of beta carotene animals and 85% of canthaxanthin animals. None of the 13-cis-retinoic acid animals had total tumor regression, but 70% showed partial regression. No tumor regression was found in the DMBA control group and the sham-injected group.

Topics: Animals; Canthaxanthin; Carcinoma, Squamous Cell; Carotenoids; Chlorophyta; Cricetinae; Cyanobacteria; Isotretinoin; Male; Mesocricetus; Mouth Mucosa; Mouth Neoplasms; Neoplasms, Multiple Primary; Plant Extracts; Remission Induction; Tretinoin; Vitamin E

To determine the efficacy of oral isotretinoin in refractory advanced squamous cell carcinoma of the skin.. Case series trial.. Tertiary care center at a university hospital.. A consecutive collection of four patients with advanced squamous cell carcinoma of the skin who failed to respond to standard surgical or radiation therapy.. Isotretinoin in gelatin capsules was given at a total daily dose of 1 mg/kg body weight in two divided doses for at least 4 weeks.. Bidimensional tumor measurements at monthly intervals showed striking responses to isotretinoin in all four patients. Response durations ranged from 2 to more than 23 months. The drug produced reversible moderate mucocutaneous side effects and asymptomatic laboratory abnormalities.. Impressive responses to isotretinoin occurred in our four patients and in six of ten other reported patients. Retinoic acid's mechanisms of action in cutaneous squamous cell carcinoma is not precisely known, but may involve the modulation of epidermal growth factor receptors and certain protein kinases. These in-vitro findings and the clinical data suggest that retinoids may be an effective and well-tolerated therapy for refractory advanced squamous cell carcinoma of the skin. The absence of any other effective systemic therapy indicates the need for continuing trials with retinoids in this disease.

Topics: Aged; Carcinoma, Squamous Cell; Combined Modality Therapy; Humans; Isotretinoin; Male; Middle Aged; Neoplasm Recurrence, Local; Skin Neoplasms; Tretinoin

The relationship among keratinocyte differentiation capacity, lipid synthesis, low-density lipoprotein (LDL) metabolism, plasma membrane composition, and epidermal growth factor (EGF) binding has been studied in SCC-12F2 cells. The differentiation capacity of the cells, i.e., ionophore-induced cornified envelope formation, was inhibited by various retinoids and stimulated by hydrocortisone. Retinoids that caused a significant reduction of cornified envelope formation, i.e., retinoic acid and 13-cis-retinoic acid, caused only minor changes in lipid synthesis and plasma membrane composition. Arotinoid ethylsulfone, having a minor effect on cornified envelope formation, caused a drastic inhibition of cholesterol synthesis, resulting in changes in the plasma membrane composition. Hydrocortisone stimulated cornified envelope formation but had only minor effects on lipid synthesis and plasma membrane composition. Of all retinoids tested, only arotinoid ethylsulfone caused a drastic increase in EGF binding, while hydrocortisone had no effect. Retinoic acid, arotinoid ethylsulfone, and hydrocortisone had no effects on LDL binding and only minor effects on LDL degradation. These results clearly demonstrate that the plasma membrane composition is not related to keratinocyte differentiation capacity, but most likely does determine EGF binding. Furthermore, EGF binding does not determine keratinocyte differentiation capacity.

Topics: Carcinoma, Squamous Cell; Cell Differentiation; Cell Line; Cell Membrane; Epidermal Growth Factor; Humans; Hydrocortisone; Lipids; Lipoproteins, LDL; Retinoids; Tretinoin

As a part of an assessment of the potential use of retinoids in preventive and adjuvant treatment of HNSCC, we examined the effects of beta-all-trans retinoic acid (RA) on the growth and cell-surface glycoconjugates of 2 HNSCC cell lines. These lines, designated 1483 and 183A, were established from an untreated patient with a well-differentiated SCC of the retromolar trigone and one with a poorly differentiated SCC of the tonsil. Whereas the 1483 cells were sensitive to RA in that their anchorage-dependent growth, their colony growth on solid substratum, and their anchorage-independent growth in semi-solid agarose gel were all inhibited in a dose-dependent fashion by RA concentrations in the range between 1 nM and 10 microM, the 183A cells were not inhibited by RA. Their anchorage-dependent growth and colony formation were stimulated by RA, whereas their anchorage-dependent colony formation was not altered. Cell-surface glycoconjugates were modulated by RA in the sensitive 1483 cells but not in the 183A cells. Treatment of the 1483 cells resulted in a large increase in the cell-surface labelling of high-molecular-weight (Mr greater than 400,000) galactoglycoconjugates and sialoglycoconjugates, as well as an Mr 280,000 sialoglycoconjugate. Glycoconjugates with similar electrophoretic mobilities in polyacrylamide gels were labelled intensely on the surface of the 183A cells even before RA treatment and only minor changes were noticed in their labelling after treatment. These results demonstrate that RA can exert different effects on different HNSCC lines, and suggest that correlations might exist between responsiveness to RA and the stage of differentiation of the HNSCC, and between modulation of cell growth and enhancement of cell-surface glycoconjugate glycosylation by RA.

Topics: Carbohydrates; Carcinoma, Squamous Cell; Cell Line; Galactosamine; Galactose; Glycosylation; Head and Neck Neoplasms; Humans; Molecular Weight; N-Acetylneuraminic Acid; Sialic Acids; Tretinoin

In five lines of cultured human squamous carcinoma cells, transglutaminase activity and envelope competence were highly sensitive to retinoic acid and calcium levels in the growth medium. In cells grown in low calcium medium, these measures of keratinocyte differentiation were reduced. Retinoic acid suppressed envelope competence but total transglutaminase activity was markedly reduced, slightly affected, or greatly stimulated depending upon the cell line and whether the cells were grown in low calcium or 1.8 mM calcium-containing medium. Examination by anion exchange chromatography of the transglutaminase activity in SCC-12B2 cultures showed that expression of the particulate form (type I) of the enzyme was greatly stimulated by calcium. The increase in this activity to high levels that occurs at confluence could be almost completely suppressed by retinoic acid in the medium. The soluble form (type II) in the SCC-12B2 cells was induced in growing or confluent cultures by retinoic acid independent of the calcium concentration in the medium, but the 50% effective concentration (100 nM) for its stimulation was approximately 50-fold higher than the 50% effective concentration for suppression of the type I enzyme (2 nM). Thus, these enzymes appear to be distinct and independently regulated. This conclusion is supported by the finding that SCC-4 and SCC-9 almost exclusively expressed types II and I forms, respectively. In contrast to the results with neoplastic cells, in cultured normal epidermal cells type I enzyme comprised the overwhelming majority of activity and was only partially (75-90%) suppressible by retinoic acid, while type II enzyme seemed poorly if at all stimulable. Thus, the SCC lines appear appropriate for studying biochemical mechanisms of action of certain physiological agents, the molecular basis for altered regulation of differentiated function in neoplastic cells, and the origin of diversity within tumors.

Topics: Calcium; Carcinoma, Squamous Cell; Cell Differentiation; Cell Membrane; Cells, Cultured; Epidermis; Humans; Tongue Neoplasms; Transglutaminases; Tretinoin

A431 malignant keratinocytes, although derived from a muco-cutaneous carcinoma of the vulva, fail to achieve terminal epidermal differentiation in culture as shown by their inability to form cornified envelopes. Even after culture in a serum-free medium (MCDB 153) containing no retinoic acid and a high (10(-3) M) calcium concentration (conditions known to facilitate epidermal differentiation), the cells do not become competent as shown by the fact that subsequent treatment with a calcium ionophore is unable to provoke the formation of cornified envelopes. Nevertheless, A431 cells are able to synthesize the envelope precursor involucrin. The block in formation of cornified envelopes is thus not due to a lack in involucrin. The results described here suggest that the absence of cross-linking of this molecule is due to a lowered epidermal membrane-bound transglutaminase activity in A431 cells when compared to normal human keratinocytes. In other respects, EGF, which inhibits the proliferation of A431 cells, enhances involucrin accumulation in these cells, although in normal human keratinocytes it stimulates growth and reduces involucrin synthesis. These results suggest that involucrin synthesis is triggered by the arrest of growth.

Topics: Calcium; Carcinoma, Squamous Cell; Cell Differentiation; Cell Line; Cell Membrane; Cells, Cultured; Culture Media; Epidermal Growth Factor; Epidermis; Female; Humans; Protein Precursors; Transglutaminases; Tretinoin

Terminal differentiation of normal and malignant keratinocytes is routinely determined by the ability of these cells to form cornified envelopes after incubation with a calcium ionophore. We have used the human squamous cell carcinoma, SqCC/Y1, to quantify cellular differentiation by the formation of detergent-insoluble protein. The methodology developed employs the metabolic labeling of detergent-insoluble cellular protein with [35S]methionine in the presence of a calcium ionophore. The ratio of filter-retainable radioactivity to that of total cellular protein was shown to be closely correlated to the results obtained by measuring the number of envelope-competent cells when cells were induced to enter a pathway of terminal differentiation in culture by serum deprivation or by treatment with hydrocortisone, and during the inhibition of maturation by either retinoic acid (RA) or epidermal growth factor (EGF). This way of measuring the degree of terminal differentiation of epidermal cells is a relatively simple one that readily allows the simultaneous measurement of multiple samples.

Topics: Blood; Carcinoma, Squamous Cell; Cell Differentiation; Cell Line; Culture Media; Epidermal Growth Factor; Epidermis; Humans; Hydrocortisone; Membrane Proteins; Skin Neoplasms; Solubility; Tretinoin

Physiologic concentrations (5 X 10(-8) M) of all-trans-retinoic acid (RA) caused a 2- to 3-fold increase in the rate of cell desquamation of a malignant keratinocyte line (SqCC/Y1) grown in serum-free medium. Measurement of the incorporation of [35S]sulfate and [3H]glucosamine into cetylpyridinium chloride-precipitable glycosaminoglycans (GAGS) demonstrated that RA treatment did not alter total GAG production. In addition, compartmental distribution was not affected by RA, with 50-70% of GAGS being recovered from the medium, 25% from the pericellular matrix, and the remainder from the cells. Relatively small amounts of GAGS were associated with shed cells in RA-treated cultures, presumably reflecting a relatively short association of these cells with the monolayer before desquamation. Chondroitin sulfate (Ch-S), heparin/heparan sulfate (Hep-S), and hyaluronic acid (HA) were the GAG species identified in SqCC/Y1 cultures by gel-exclusion chromatography. RA reduced the relative amount of HA in the trypsin-sensitive pericellular compartment by 50%. Since the proportions of Ch-S and Hep-S were not affected by RA, the findings suggest that the altered ratio of HA to sulfated GAGS in this fraction may contribute to the increased cell desquamation. Hydrocortisone (10(-6) M) reversed the effect of RA on cell shedding, and increased the proportion of pericellular HA relative to that found in cultures exposed to RA alone. These findings support the concept that the relative proportion of HA to sulfated GAGS may be important in the intercellular cohesion of keratinocytes. In addition, the relative decrease in HA and the predominance of Ch-S over Hep-S in SqCC/Y1 cultures differed from results reported with normal keratinocytes, indicating that this property may be associated with the malignant phenotype.

Topics: Carcinoma, Squamous Cell; Cell Line; Cheek; Glycosaminoglycans; Humans; Hydrocortisone; Mouth Mucosa; Mouth Neoplasms; Neoplasms, Experimental; Skin; Tretinoin

Growth of SCC-13 squamous carcinoma cultures in the presence of retinoids considerably reduced the expression of two differentiation markers, the cellular capability to form cross-linked envelopes, and the enzyme transglutaminase required for cross-linking. A limited survey of retinoids showed that all-trans retinoic acid, 13-cis retinoic acid, and arotinoid Ro 13-6298 were highly effective in the absence of hydrocortisone and were only slightly antagonized by its presence in the medium. In contrast, retinyl acetate, retinol, and retinol bound to its plasma binding protein were quite active in the absence of hydrocortisone but were essentially inactive in its presence. Dexamethasone was also highly effective in antagonizing the suppressive action of retinyl acetate on envelope formation, while the corticosteroid antagonists cortexolone and progesterone were inactive. These results suggest that there are separate pathways, which are differentially regulated by hydrocortisone, for either the metabolism or action of retinol and retinoic acid in SCC-13 cells.

Topics: Acyltransferases; Carcinoma, Squamous Cell; Cell Line; Cell Membrane; Diterpenes; Humans; Hydrocortisone; Kinetics; Retinoids; Retinyl Esters; Structure-Activity Relationship; Transglutaminases; Tretinoin; Vitamin A

A malignant human cell line (SqCC/Y1) derived from a squamous carcinoma of the buccal mucosa is described. It formed a stratified cellular structure with ultrastructural characteristics of a fully differentiated stratified squamous epithelium when cultured in equal parts of Dulbecco's modified Eagle medium and Ham's medium F12, supplemented only with insulin, transferrin, and selenium. After 14 days in culture in this defined medium, 30% of the cells became keratinized (insoluble in detergent), and 75% of the cells were capable of being induced to form cornified cell envelopes. Involucrin, the precursor protein of the cornified cell envelope, could be detected by immunofluorescence only in suprabasal cells. Treatment of SqCC/Y1 cultures with 5 X 10(-8) M all-trans-retinoic acid (RA) completely inhibited stratification and markedly increased cell desquamation. In the presence of RA, less than 10% of the cells became keratinized, and only 15-20% of the cells acquired envelope-forming competence. The fraction of colony-forming cells in RA-treated cultures was tenfold higher than in fully mature cultures. Thus RA appears to be an effective inhibitor of terminal differentiation of SqCC/Y1 cells.

Topics: Carcinoma, Squamous Cell; Cell Differentiation; Cell Line; Culture Media; Humans; Neoplastic Stem Cells; Protein Precursors; Tretinoin

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinogens; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Cocarcinogenesis; Croton Oil; Fluocinolone Acetonide; Mice; Mice, Inbred Strains; Papilloma; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate; Tosylphenylalanyl Chloromethyl Ketone; Tretinoin

The concentration of cellular retinoic acid binding proteins (CRABP) was determined in the cytosol of normal esophageal tissue and in esophageal carcinomas. Unlike the reported results for human breast, colon, melanoma, or oropharynx cancers, the CRABP levels in esophageal cancers were either undetectable or contained levels of CRABP which were significantly lower than that of adjacent histologically disease-free tissue (P less than 0.005). Moreover, there was no difference between the normal mucosa of cancer or noncancer patients with regards to the CRABP concentration. The absence of CRABP in the cancer tissue was not dependent on the degree of differentiation. These results indicate that the CRABP disappears when the normal mucosa becomes malignant. If such a change is also demonstrated in known premalignant conditions of the esophagus, CRABP could serve as a diagnostic biochemical marker for early detection of this cancer.

Topics: Adenocarcinoma; Adult; Aged; Carcinoma, Squamous Cell; Carrier Proteins; Centrifugation, Density Gradient; Esophageal Neoplasms; Esophagus; Female; Humans; Male; Middle Aged; Neoplasm Proteins; Receptors, Retinoic Acid; Tretinoin

An 83-year-old woman with multiple squamous cell carcinomas and keratoacanthomas of the legs was treated with orally administered isotretinoin (13 cis-retinoic acid). Complete regression of the tumors was noted during the initial six-month treatment period. In the subsequent 36 months, four new cutaneous tumors were excised. There have been no recurrences of lesions that regressed while the patient was receiving retinoid therapy.

Topics: Administration, Oral; Aged; Carcinoma, Squamous Cell; Female; Humans; Isotretinoin; Keratoacanthoma; Leg; Skin Diseases; Skin Neoplasms; Tretinoin

The serum levels of retinol, RBP (retinol-binding protein) and PALB (prealbumin) were found to be significantly lower in patients with malignant tumors of the head and neck region than in controls. In tumor tissues as well as in normal laryngeal mucosa, specific binding sites for retinol and retinoic acid were found. Whereas retinol-binding (CRBP = cellular retinol-binding protein) could only be detected in a few cases, binding for retinoic acid (CRABP = cellular retinoic acid-binding protein) was present in all specimens investigated. The presence or lack of binding sites was not dependent on the actual serum retinol levels. With regard to the antineoplastic role of vitamin A, the reduced serum levels are considered as a possible factor in tumor development and growth. CRBP and CRABP are assumed to be mediating factors for the retinol and retinoic acid action. Since the presence of CRABP is a constant finding, we propose that retinoic acid and its synthetic derivatives with high affinity for CRABP could be appropriate antineoplastic drugs in these tissues.

Topics: Carcinoma, Squamous Cell; Head and Neck Neoplasms; Humans; Laryngeal Mucosa; Male; Middle Aged; Prealbumin; Retinol-Binding Proteins; Retinol-Binding Proteins, Cellular; Tretinoin; Vitamin A

Topics: Bowen's Disease; Carcinoma, Squamous Cell; Etretinate; Genital Neoplasms, Male; Humans; Male; Recurrence; Skin Neoplasms; Tretinoin

We investigated the effect of the synthetic vitamin A derivative isotretinoin (13-cis-retinoic acid) on advanced cancers in 103 patients and on preneoplastic lesions in five patients. Six of 14 patients with squamous cell epithelial cancers had objective regressions of skin or subcutaneous metastases. Three of five patients with preneoplastic lesions had objective responses. The major dose-limiting toxic effects were reversible dermatitis, emotional lability, and headaches. We conclude that the growth of some squamous cell epithelial malignancies can be inhibited by isotretinoin and suggest that other retinoids should be evaluated as antitumor agents.

Topics: Antineoplastic Agents; Carcinoma, Squamous Cell; Drug Eruptions; Drug Evaluation; Emotions; Headache; Humans; Isotretinoin; Neoplasms; Precancerous Conditions; Tretinoin

After in vitro incubation of human squamous cell carcinomas of the head and neck region with aromatic retinoid an increased number of lysosomes can be observed in the tumor cells. It is discussed whether this accumulaion of lysosomes is due to a direct stimulation of lysosomal enzyme synthesis or whether it is consequence of cell damage by the retinoid.

Topics: Acid Phosphatase; Acitretin; Carcinoma, Squamous Cell; Culture Techniques; Dose-Response Relationship, Drug; Humans; Laryngeal Neoplasms; Lysosomes; Mouth Neoplasms; Tretinoin

Pathological and histochemical studies were made to clarify the response to an aromatic retinoids (Ro 10-1670, Ro 10-9359) of the papilloma and carcinoma in hamster cheek pouch and mouse dorsal skin. The sizes of papilloma and carcinoma were remarkably reduced or completely regressed following systemic and topical administration of the aromatic retinoids. The antitumor effects increased in proportion to the frequency of administration than doses and were showed no side effects. Tumor tissues responded remarkably to the aromatic retinoids indicated an irregular keratinization including loss of hornified cells, nuclear vacuolization and inflammatory infiltrates which located in the border layer between stromas and neoplastic epithelia. Histochemically, tumor tissues which intensely affected by drugs were characterized by the presence of abundant acid phosphatase active cells. Those acid phosphatase active cells may be consisted of tumor cells, histiocytes and fibroblasts. In the electrocytochemical study acid phosphatase (a lysosomal marker enzyme) activity was found in epithelial tumor cells and fibroblasts. These results were indicated that epithelial tumor regression by aromatic retinoids the might be due to the accelerated lysosomal activity in the tumor cells and fibroblasts.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Acitretin; Animals; Antineoplastic Agents; Carcinoma, Squamous Cell; Cricetinae; Etretinate; Mesocricetus; Mice; Neoplasms, Experimental; Papilloma; Skin Neoplasms; Tretinoin

Epidermoid carcinomas of the oral cavity and oropharynx from six patients were examined for the presence and amount of cellular retinol (CRBP) and cellular retinoic acid-binding (CRABP) proteins. In all cases adjacent, grossly normal tissue was similarly examined. For each example CRBP levels were significantly higher in tumor tissue compared to adjacent tissue. In four cases CRABP was significantly higher. This is of interest because retinol, retinoic acid and their analogs have been shown to inhibit the development of various epithelial tumors, and this inhibition is possibly mediated by these binding proteins.

Topics: Carcinoma, Squamous Cell; Carrier Proteins; Centrifugation, Density Gradient; Female; Humans; Male; Mouth Neoplasms; Oropharynx; Pharyngeal Neoplasms; Receptors, Retinoic Acid; Retinol-Binding Proteins; Retinol-Binding Proteins, Cellular; Tretinoin; Vitamin A

In some squamous cell carcinomas of the otorhinolaryngologic region with different grades of differentiation, a protein was found that specifically binds vitamin A acid. In 28 of 37 tumors, the retinoic acid-binding sites were found in significant amounts, according to the authors' data. Areas with metastases showed a lower incidence of retinoic acid-binding, whereas in all normal epiglottis and vocal cord tissue specimens the binding was present. The possible significance of the protein-binding for the biologic effect of the vitamin A acid is discussed.

Topics: Binding Sites; Binding, Competitive; Carcinoma, Squamous Cell; Centrifugation, Density Gradient; Etretinate; Head and Neck Neoplasms; Humans; Neoplasms; Otorhinolaryngologic Diseases; Protein Binding; Tretinoin; Vitamin A

Topics: Aged; Carcinoma, Squamous Cell; Etretinate; Humans; Keratosis; Lung Neoplasms; Male; Paraneoplastic Syndromes; Skin; Tretinoin

Topics: Adult; Bowen's Disease; Carcinoma, Squamous Cell; Etretinate; Female; Humans; Skin Neoplasms; Tretinoin; Vulvar Neoplasms

Cellular retinoic acid-binding protein (CRABP) was detected in the cytosol of 11 human non-small-cell lung cancer specimens. Neither normal lung nor a small-cell lung cancer specimen contained this binding protein. The quality of CRABP per milligram of cytosol protein ranged from 48.3 to 426.5 fmol.

Topics: Adenocarcinoma; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Carrier Proteins; Cytosol; Humans; Lung Neoplasms; Receptors, Retinoic Acid; Tretinoin

In order to determine whether 13-cis-retinoic acid, an analog of vitamin A, has antitumor activity in an oral cancer model system, the following study was undertaken. Fifty-three adult hamsters were divided into four groups. Group 1 was tested with a 0.5 percent solution of 9,10-dimethyl-1,2-benzanthracene (DMBA) in heavy mineral oil, which was painted on the right buccal pouch three times per week for 12 weeks. Group 2 received DMBA plus 13-cis-retinoic acid (RA) incorporated into gelatinized beadlets and mixed with a powdered commercial diet (dosage, 300 mg per kilogram of diet). Group 3 received only RA; Group 4 received a placebo. The animals were killed at 6, 12, and 18 weeks and tissues were studied clinically and histologically in a routine manner. Results show that all groups receiving DMBA developed epidermoid carcinomas. However, there were several other changes. In the RA-treated animals, particularly those treated with DMBA, there was an ingrowth of surface epithelium with development of ductal structures in the buccal pouch. There were changes in surface epithelium, and there were dense aggregates of lymphoid tissue with development of exophytic nodules suggestive of lymphoma. Animals fed RA showed a relative weight loss. The findings suggest that there was a hypervitaminosis A state yielding prominent epithelial metaplastic changes but not affecting the progression or production of carcinoma.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Benz(a)Anthracenes; Carcinoma, Squamous Cell; Cheek; Cricetinae; Female; Isotretinoin; Male; Mesocricetus; Mouth Neoplasms; Neoplasms, Experimental; Tretinoin

Topics: Animals; Carcinoma, Squamous Cell; Etretinate; Histocytochemistry; Mice; Neoplasms, Experimental; Tretinoin

Topics: Administration, Oral; Adult; Animals; Carcinoma, Squamous Cell; Etretinate; Humans; Male; Papillomaviridae; Skin Diseases, Infectious; Skin Neoplasms; Tretinoin; Tumor Virus Infections

Blinded analyses of the concentrations of binding proteins for retinol and retinoic acid (CRABP) in homogenates of cancer and normal tissue aliquots obtained from human cervix, endometrium, ovary, breast, and lung were carried out by the sucrose gradient ultracentrifugation technique. In carcinomas of the cervix and endometrium, CRABP mean values of 50.4 and 123.2 pmol/g tissue, respectively were detected. Such concentrations represent a 3- and 4-fold increase over the mean values of CRABP in the normal cervix (16.9 pmol/g) and normal endometrium (30.8 pmol/g), respectively. In carcinomas of the ovary, the mean CRABP level was 128.6 pmol/g compared to the maximal mean value of less than or equal to 0.46 pmol/g in the normal ovary. Elevated levels of CRABP were also found in breast and lung carcinomas compared to the amounts detected in the same patient in normal tissue aliquots of the same organ. The differences between CRABP concentrations in cervical, endometrial, ovarian, and breast carcinomas and those in normal tissue are statistically significant. In contrast, cellular retinol-binding protein concentrations were reduced in the endometrial, ovarian, breast, and lung carcinomas compared to normal tissues. There were no significant differences between the log-mean concentrations of cellular retinol-binding proteins in the cytosols from tissue aliquots of carcinoma of the cervix and those in the cytosols from tissue aliquots of normal cervix.

Topics: Carcinoma; Carcinoma, Squamous Cell; Carrier Proteins; Endometrium; Female; Genital Neoplasms, Female; Humans; Neoplasm Proteins; Ovarian Neoplasms; Receptors, Retinoic Acid; Retinol-Binding Proteins; Retinol-Binding Proteins, Cellular; Tretinoin; Uterine Cervical Neoplasms; Uterine Neoplasms

Sixty-four male and female Syrian hamsters, 3 months of age and weighing 90 to 120 grams, were divided into four equal experimental groups. In animals of Groups 1 and 2 the right posterior lateral border of the tongue was painted three times weekly with a 0.5 percent solution of DMBA in acetone. Group 2 animals also received 10 mg. of 13-cis-retinoic acid in peanut oil administered orally twice weekly by pipette. Carcinogen and retinoid were administered on alternate days. Group 3 animals received only 13-cis-retinoic acid. Group 4 animals served as untreated controls. Four animals in each group were killed at 12, 14, 16, and 18 weeks. The Group 2 animals, receiving 13-cis-retinoic acid, exhibited a significant delay in the development of lingual tumors, both grossly and microscopically. At 14 weeks carcinomas were found in the DMBA animals, but only dysplasia and areas of carcinoma in situ were found in the DMBA-retinoid animals. After 18 weeks the DMBA animals exhibited large lingual tumors with surfacenecrosis, while the DMBA-retinoid animals presented smaller tumors with less invasion of underlying tissue.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinoma, Papillary; Carcinoma, Squamous Cell; Cricetinae; Female; Isotretinoin; Leukoplakia, Oral; Male; Mesocricetus; Neoplasms, Experimental; Tongue; Tongue Neoplasms; Tretinoin

Sixty-four male and female Syrian golden hamsters (Mesocricetus auratus) were divided into 4 equal groups. Group 1 animals had the posterior lateral borders of their tongues painted three times weekly with a 0.5% solution of 7,12-dimethylbenz[a]anthracene (DMBA) in acetone. Group 2 animals were painted with DMBA and also received 10 mg of 13-cis-retinoic acid in peanut oil administered orally by pipette twice weekly. Group 3 animals received only retinoid, and group 4 animals were untreated controls. Four animals in each group were killed at 12, 14, 16, and 18 weeks. In the DMBA-painted animals receiving 13-cis-retinoic acid, the leukoplakia and epidermoid carcinomas developed more slowly and were better differentiated microscopically. The better degree of differentiation was demonstrated by ultrastructural studies. Less cellular separation and fewer microvilli-like structures were evident. No tubular mitochondria were observed. Less dispersion of heterochromatin occurred throughout nuclei, and the basal lamina tended to be regular and continuous.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Basement Membrane; Carcinoma, Squamous Cell; Cell Nucleus; Cricetinae; Cytoplasm; Female; Male; Tongue Neoplasms; Tretinoin

Sixty-four male and female Syrian hamsters, 3 months of age and weighing 90 to 120 grams, were divided into four equal experimental groups. In animals of Groups 1 and 2 the left buccal pouch was painted three times weekly with a 0.5% solution of DMBA in heavy mineral oil. Group 2 animals also received 10 mg. of 13-cis-retinoic acid in peanut oil administered orally twice a week by pipette. Carcinogen retinoid were administered on alternate days. Group 3 animals served as controls, receiving only 13-cis-retinoic acid. Group 4 animals served as untreated controls. Four animals in each group (two males and two females) were killed at 10, 12, 14, and 16 weeks. The Group 2 animals, which received 13-cis-retinoic acid, exhibited a significant delay in DMBA carcinogenesis of buccal pouch mucosa, as studied both grossly and histologically. Both groups eventually demonstrated well-differentiated epidermoid carcinomas, but the tumors were smaller in the DMBA-retinoid animals.

Topics: Animals; Carcinoma, Papillary; Carcinoma, Squamous Cell; Cheek; Cricetinae; Female; Isotretinoin; Keratosis; Leukoplakia, Oral; Male; Mesocricetus; Mouth Mucosa; Mouth Neoplasms; Neoplasms, Experimental; Tretinoin

Topics: Animals; Carcinoma, Squamous Cell; Cell Division; Cell Survival; Cells, Cultured; Depression, Chemical; Dose-Response Relationship, Drug; Lung Neoplasms; Mice; Neoplasms, Experimental; Tretinoin

Topics: Animals; Carcinoma, Squamous Cell; Humans; Lipoproteins, VLDL; Rats; Skin Diseases; Tretinoin; Triglycerides; Vitamin A; Vitamin A Deficiency

Beneficial effects of oral retinoids in prophylaxis of epithelial neoplasias have been demonstrated by experimental works. In this study oral retinoid (RO 10-9359) was used in human dermatosis with high frequency of cutaneous malignancies: xeroderma pigmentosum with or without malignant neoplasias, Mibelli's porokeratosis with multifocal malignant degeneration, basal cell naevus syndrome with basal cell carcinomas, familial epithelioma of Ferguson-Smith and actinic keratosis. This work started in december 1977. Visible epitheliomas have been treated before trial. Initial dose of retinoid was 1 mg/kg daily, decreased depending on individual tolerance. Results were appreciated by comparising number of epitheliomas observed in years preceding retinoid therapy and number of them appearing during treatment; in two familial cases (basal cell naevus syndrom in twins and xeroderma pigmentosum in two brothers) comparison was made between treated and untreated patients. First results are very promising: an excellent response on solar keratosis is noted; epitheliomas occurrence seems actually to be prevented or delayed by oral retinoid therapy. Of course more numerous cases, a longer time, periods without treatment are necessary to confirm these interesting first results. On the other hand drug is not with this dose active on already constituted carcinomas.

Topics: Adolescent; Basal Cell Nevus Syndrome; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Child; Etretinate; Female; Humans; Keratosis; Male; Precancerous Conditions; Skin Diseases; Skin Neoplasms; Tretinoin; Xeroderma Pigmentosum

Topics: Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Epithelium; Etretinate; Humans; Skin Diseases; Skin Neoplasms; Tretinoin; Vitamin A

Animal studies have shown. a) an association between vitamin A and cancers of epithelial origin, and b) that vitamin A and its analogues delay tumour appearance, retard tumour growth and regress tumours induced by carcinogenic polycyclic aromatic hydrocarbons. Human epidemiological and biochemical studies suggest that cancers of epithelial origin may be associated with vitamin A deficiency. Vitamin A and its analogues may have a prophylactic and a therapeutic role in cancers of epithelial origin.

Topics: Animals; Bronchial Neoplasms; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Humans; Lung Neoplasms; Mouth Neoplasms; Neoplasms, Experimental; Pharyngeal Neoplasms; Tretinoin; Vitamin A; Vitamin A Deficiency

Topics: Carcinogens; Carcinoma, Squamous Cell; Cell Differentiation; Cell Transformation, Neoplastic; Growth Inhibitors; Tretinoin; Vitamin A

The effect of 13-cis-retinoic acid on the induction of urinary bladder carcinoma by N-butyl-N-(4-hydroxybutyl)nitrosamine (OH-BBN) was studied in male C57BL/6 mice. Animals received a total dose of either 90 or 140 mg of OH-BBN via gastric intubations of 7.5 or 10.0 mg of OH-BBN 2 times each week for 6 or 7 weeks, respectively. Seven days after the last OH-BBN intubation, animals were fed laboratory chow diet supplemented with either 200 mg of 13-cis-retinoic acid per kg or its placebo. Animals were killed at 6 months after the first carcinogen intubation. Highly invasive squamous and transitional cell carcinomas of the urothelium were found at autopsy. In the majority of these carcinomas, invasion of the bladder muscle wall by tumor cells had occurred. At the two dose levels of OH-BBN, feeding of 13-cis-retinoic acid reduced the incidence of both carcinomas and noninvasive papillomas, as well as the extent of neoplastic development in the urinary bladder. In mice receiving the lower dose of OH-BBN, the feeding of 13-cis-retinoic acid prevented the appearance of both squamous and transitional cell carcinomas with a reduction in incidence from 33 to 0% (p less than 0.01). The results of this study indicate that 13-cis-retinoic acid reduced not only the severity of highly invasive urinary bladder carcinomas but also the incidence of such cancers.

Topics: Animals; Butylhydroxybutylnitrosamine; Carcinoma, Squamous Cell; Carcinoma, Transitional Cell; Male; Mice; Mice, Inbred C57BL; Neoplasms, Experimental; Nitrosamines; Tretinoin; Urinary Bladder Neoplasms; Vitamin A

Transitional cell and squamous cell cancer of the bladder was induced in Wistar/Lewis female rats by direct instillation of N-methyl-N-nitrosourea into the bladder. Feeding of the synthetic retinoid, 13-cis-retinoid acid, inhibited the incidence and extent of bladder cancer in these rats, even when 13-cis-retinoic acid administration was begun after completion of the carcinogen treatment.

Topics: Animals; Carcinoma, Squamous Cell; Carcinoma, Transitional Cell; Female; Methylnitrosourea; Neoplasms, Experimental; Rats; Tretinoin; Urinary Bladder Neoplasms; Vitamin A