bromochloroacetic-acid and Papilloma

Papillary lesions of the breast represent a heterogeneous group with differing biological behaviour. Correct diagnosis is crucial but may be difficult, as many benign and malignant papillary lesions have similar appearances. Immunohistochemistry plays a useful role in their differentiation. Myoepithelial markers can help in differentiating papilloma from papillary carcinoma, as the former usually shows a continuous layer of myoepithelial cells. In intracystic papillary carcinoma, there is controversy as to the presence of a complete myoepithelial cell layer around these lesions. p63 is the marker of choice as the staining is nuclear, cross-reactivity is minimal, and sensitivity is high. Papilloma may frequently be complicated by superimposed different types of epithelial hyperplasia, which range from usual to atypical or even ductal carcinoma in situ, and they many be morphologically similar. Basal cytokeratins (CKs) are useful to differentiate these entities; as usual hyperplasia is positive for basal CKs with a mosaic staining pattern. CK5/6 is probably the best marker. Neuroendocrine markers (chromogranin A and synaptophysin) may be positive in papillary carcinoma, particularly in the solid type, and there may be some overlap with the ductal carcinoma in situ with spindle cells or endocrine ductal carcinoma in situ. A panel of CK5/6, p63 and neuroendocrine markers can be useful in the diagnostic investigation of problematic papillary lesions of the breast. As the experience with these markers remains rather limited, it is too early to recommend basing treatment choices on these marker studies alone. Complete removal of lesion is probably still the treatment of choice.

Topics: Biomarkers, Tumor; Breast Neoplasms; Carcinoma, Intraductal, Noninfiltrating; Carcinoma, Papillary; Diagnosis, Differential; Female; Humans; Keratins; Neoplasm Proteins; Nerve Tissue Proteins; Papilloma

Choroid plexus tumors are rare intraventricular papillary neoplasms derived from choroid plexus epithelium, which account for only between 0.4-0.6% of all intracranial and 2-3% of pediatric neoplasms. Plexus papillomas outnumber choroid plexus carcinomas by a ratio of 5:1 and around 80% of choroid plexus carcinomas arise in children. Plexus tumors are most common in the lateral and fourth ventricles; while 80% of lateral ventricle tumors present in children, fourth ventricle tumors are evenly distributed in all age groups. Clinically, choroid plexus tumors tend to cause hydrocephalus and increased intracranial pressure. Histologically, choroid plexus papillomas correspond to WHO grade I, choroid plexus carcinomas to WHO grade III. Immunohistochemically, cytokeratins and vimentin are expressed by virtually all choroid plexus papillomas and most choroid plexus carcinomas while transthyretin and S-100 protein are present in 80-90% of cases, less frequently, though, in choroid plexus carcinomas. Glial fibrillary acidic protein can be found focally in about 25-55% of choroid plexus papillomas and 20% of choroid plexus carcinomas. The mean Ki67/MIB1 labeling index for choroid plexus papillomas is 1.9%, for choroid plexus carcinomas 13. 8%. Choroid plexus papillomas typically show hyperdiploidy with gains particularly on chromosomes 7, 9, 12, 15, 17, and 18 while one choroid plexus carcinoma showed rearrangements of chromosomes 7p11-12, 9q11-12, 15q22, and 19q13.4. Choroid plexus papillomas can usually be cured by surgery alone with a 5-year survival rate of up to 100% with occasional recurrences while choroid plexus carcinomas grow more rapidly and have a less favorable outcome with a 5-year survival rate of 26-40%.

Topics: Animals; Choroid Plexus Neoplasms; Chromosome Aberrations; Diagnosis, Differential; Humans; Immunohistochemistry; Keratins; Papilloma

We describe a case of solitary papilloma of the bronchus and provide a review of 38 similar cases reported in Japan. A 70-year-old man complained of cough and sputum. Chest X-rays and CT scans revealed atelectasis of the right middle lobe. On bronchoscopy, a polypoid tumor was found at the orifice of the bronchus of the right middle lobe. The tumor was histologically diagnosed as a squamous papilloma with moderate atypia. Because of elevated tumor markers and the reported high incidence of malignant changes in papillomas, the tumor was endoscopically resected by electrosurgical snare. While this procedure resulted in improvement of atelectasis, the chest CT taken subsequently revealed a mass adjacent to the resected polypoid tumor in the middle lobe bronchus. Percutaneous needle biopsy followed by histopathological examination confirmed the tumor to be a squamous cell carcinoma. Only three cases of malignant changes in papillomas have been previously reported in Japan. Electrosurgical snare, which allows the identification of tissue at the tumor base, should be the treatment of choice rather than YAG laser surgery.

Topics: Aged; Antigens, Neoplasm; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Biopsy, Needle; Bronchial Neoplasms; Carcinoma, Squamous Cell; Cisplatin; Combined Modality Therapy; Contraindications; Disease Progression; Electrosurgery; Humans; Keratins; Male; Mitomycin; Neoplasm Proteins; Papilloma; Parkinson Disease, Secondary; Pneumonectomy; Pulmonary Atelectasis; Serpins; Tomography, X-Ray Computed; Vindesine

Oncocytic schneiderian papillomas (OSPs) are uncommon benign neoplasms that arise from the sinonasal schneiderian epithelium. Malignancies arising in OSPs are rare, and, to our knowledge, only 14 such instances have been reported in the medical literature. We report 2 additional cases--a small cell carcinoma and a sinonasal undifferentiated carcinoma arising in OSPs and presenting synchronously with the benign neoplasm. The potential for malignant transformation in OSPs is small, but warrants that these papillomas be completely excised to exclude a coexisting carcinoma.

Topics: Aged; Biomarkers; Biopsy; Carcinoma; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Nasal Mucosa; Nose Neoplasms; Papilloma; Paranasal Sinuses

A sensitive in situ hybridization test under low stringency conditions (LCS) with a set of digoxigenin-labeled human papillomavirus mixed probes (D-L HPV MP) revealed a positive reaction in 8 of 10 cases of oral verruca vulgaris (OVV). Ages ranged from 5 to 37 years with a mean of 14.5 years. 50% of all cases were located intraorally on the hard palate, followed in frequency by the commissures. These preliminary findings provide evidence of the role of HPV in OVV from a sample of the Venezuelan population. We show that in situ hybridization conducted under LSC is useful in HPV detection (regardless of the type) and the digoxigenin-labeling system is a rapid, relatively easy and specific method. In addition, this technique permits the retrospective evaluation of routinely processed material, thus widening the investigative spectrum for HPV.

Topics: Adolescent; Adult; Cell Nucleus; Child; Child, Preschool; Condylomata Acuminata; DNA Probes, HPV; Epithelium; Female; Humans; Keratins; Male; Mouth Diseases; Mouth Neoplasms; Nucleic Acid Hybridization; Papilloma; Papillomaviridae; Venezuela; Warts

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Biomarkers, Tumor; Cell Transformation, Neoplastic; Chromosome Aberrations; Chromosome Disorders; Karyotyping; Keratins; Mice; Papilloma; Precancerous Conditions; Skin Neoplasms; Tetradecanoylphorbol Acetate; Time Factors

Topics: Animals; Carcinoma; Cell Differentiation; DNA Probes; Keratins; Mice; Papilloma; Precancerous Conditions; Skin Neoplasms

Epidermal tumourigenesis can be achieved in rodents by the application of a single subthreshold dose of a carcinogen (initiation) followed by repeated applications of a tumour promoter such as 12-0-tetradecanoyl phorbol, 13-acetate (TPA). TPA induces terminal differentiation in the majority of epidermal keratinocytes in vitro. However, transformed keratinocytes respond weakly to this terminal differentiation signal, and it is suggested that this property allows initiated cells and their progeny to obtain a selective advantage over their normal counterparts during promotion of papilloma formation by TPA. New data are reviewed which suggest that a putative wound hormone TGF-beta has similar differential effects on normal and transformed epithelial cells to those of TPA. It is proposed that the release of TGF-beta from platelets following deep skin wounding may be an explanation as to why wounding is a promoting stimulus but milder forms of epidermal injury are not. Weakly promoting hyperplasiogenic agents are also discussed within the context of a selection theory of tumour promotion.

Topics: Animals; Carcinogens; Cell Differentiation; Cell Transformation, Neoplastic; Epidermis; In Vitro Techniques; Keratins; Mice; Mitosis; Oncogenes; Papilloma; Peptides; Phenotype; Phorbols; Protein Kinase C; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate; Transforming Growth Factors

Papillomaviruses induce tumors of keratinocytes. Vegetative viral DNA replication and virion assembly are seen in those cells which are in the process of keratinizing or are keratinized. To date, no cell culture system has been developed that permits expression of the complete viral life cycle. Keratinocytes infected in culture may harbor the virus as a stable, replicating episome, but they do not support vegetative viral growth, nor do they become immortalized or transformed. The major obstacle in using keratinocyte cultures may be related to a dual need for transformation and full differentiation. Some animal papillomaviruses have been shown to be capable of transforming cultured murine fibroblasts. The fibroblast model is useful for identifying the viral-transforming gene(s) and their products.

Topics: Animals; Cattle; Cell Line; Cell Transformation, Viral; DNA Replication; Epidermal Cells; Epidermis; Fibroblasts; Humans; Keratins; Laryngeal Neoplasms; Mice; Papilloma; Papillomaviridae; Rabbits; Virus Cultivation; Virus Replication

Topics: China; Humans; Keratin-16; Keratin-9; Keratins; Keratoderma, Palmoplantar; Keratoderma, Palmoplantar, Diffuse; Mutation; Papilloma; Pedigree

Heck's disease (focal or multifocal epithelial hyperplasia) is a benign, rare condition of the skin and mucous membranes induced by human papillomavirus (HPV) infection. Other entities that can induce large papillomatous lesions that involve the mucous membranes and skin include condyloma acuminatum, which is sexually transmitted, and white sponge nevus, often due to a mutation of cytokeratin 4 or 13. Six cases diagnosed as either Heck's disease (n = 2) or white sponge nevus (n = 4) and 6 oral condyloma were compared on histologic grounds and analyzed in situ for HPV DNA, including HPVs 6,11, and 13, as well as cytokeratins 4 and 13. Each case showed marked acanthosis, and para/hyperkeratosis. More variable histologic findings included rete ridge elongation, keratinocyte degeneration, and perinuclear halos. High copy HPV 13 DNA was evident in the squamous cells towards the surface in the two cases diagnosed as Heck's disease and in two cases diagnosed as white sponge nevus on clinical grounds. HPV 6/11 was found in each of the six condyloma. Marked decrease in either cytokeratin 4 or 13 was evident in the two cases diagnosed as white sponge nevus that were HPV DNA negative. It is concluded that in situ hybridization analyses including HPVs 6, 11, and 13 as well as immunohistochemistry for cytokeratins 4 and 13 can differentiate Heck's disease from condyloma and white sponge nevus, which can be difficult to differentiate on clinical and histologic grounds.

Topics: Adult; Biomarkers; Cell Differentiation; Condylomata Acuminata; DNA, Viral; Female; Focal Epithelial Hyperplasia; Humans; Hyperplasia; In Situ Hybridization; Keratins; Leukokeratosis, Hereditary Mucosal; Male; Middle Aged; Nevus; Papilloma; Papillomaviridae; Papillomavirus Infections; Skin

Papilloma is a benign tumor of the malpighian layer, usualy affecting the skin. Thickened epithelium doesn't show cytological or architectural abnormalities; the epithelial proliferation is still clearly separated from the dermis by the basal membrane, that is to say absence of tumor infiltration. We here report the case of a 15-year-old boy presenting with oozing plague in his left elbow that had evolved over the previous two months. The patient had no particular previous history. Physical examination showed good general condition and a papular, squamous, itchy, oozing lesion measuring 4 cm along its longer axis. The remainder of the physical examination was normal. He was treated with topical emollient, antimycotics and quinolone antibiotics. Drying of the purulent oozing was observed, but no improvement in the general appearance of the lesion. Laboratory tests, including glucose tolerance test, were normal. A biopsy of the lesion was performed. Anatomo-pathological examination of skin biopsy specimen showed no abnormal cells, rather an elongation of the epidermal ridges as well as of the connective papillae, extensive keratinization of the surface and thickening of the malpighian layer. The diagnosis of papilloma was retained. Surgical excision of the tumor resulted in complete healing.

Topics: Adolescent; Biopsy; Humans; Keratins; Male; Papilloma; Skin Neoplasms

We used allogeneic bone marrow transplantation (BMT) and a mouse multistage cutaneous carcinogenesis model to probe recruitment of bone marrow-derived epithelial cells (BMDECs) in skin tumors initiated with the carcinogen, dimethylbenz[a]anthracene (DMBA), and promoted with 12-O-tetradecanolyphorbol-13-acetate (TPA). BMDECs clustered in the lesional epithelium, expressed cytokeratins, proliferated, and stratified. We detected cytokeratin induction in plastic-adherent bone marrow cells (BMCs) cultured in the presence of filter-separated keratinocytes (KCs) and bone morphogenetic protein 5 (BMP5). Lineage-depleted BMCs migrated towards High Mobility Group Box 1 (HMGB1) protein and epidermal KCs in ex vivo invasion assays. Naive female mice receiving BMTs from DMBA-treated donors developed benign and malignant lesions after TPA promotion alone. We conclude that BMDECs contribute to the development of papillomas and dysplasia, demonstrating a systemic contribution to these lesions. Furthermore, carcinogen-exposed BMCs can initiate benign and malignant lesions upon tumor promotion. Ultimately, these findings may suggest targets for treatment of non-melanoma skin cancers.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Bone Marrow Cells; Bone Marrow Transplantation; Bone Morphogenetic Protein 5; Cell Movement; Cell Plasticity; Cell Transformation, Neoplastic; Coculture Techniques; Epithelial Cells; Female; Hair Follicle; HMGB1 Protein; Keratinocytes; Keratins; Male; Mice; Mice, Inbred C57BL; Neoplasm Invasiveness; Papilloma; Skin Neoplasms; Stem Cells; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured

Multipotent stromal cells (MSCs) are envisioned as a powerful therapeutic tool. As they home into tumors, secrete trophic and vasculogenic factors, and suppress immune response their role in carcinogenesis is a matter of controversy. Worldwide oral squamous cell carcinoma (OSCC) is the fifth most common epithelial cancer. Our aim was to determine whether MSC administration at precancerous stage modifies the natural progression of OSCC. OSCC was induced in Syrian hamsters by topical application of DMBA in the buccal pouch. At papilloma stage, the vehicle or 3×10

Topics: Animals; Apoptosis; Bone Marrow Cells; Carcinoma, Squamous Cell; Caspase 3; Cell Dedifferentiation; Cell Line, Tumor; Cell Proliferation; Cricetinae; Disease Progression; Down-Regulation; Epithelial Cells; Female; Hyperplasia; Immunophenotyping; Keratins; Ki-67 Antigen; Leukocyte Common Antigens; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mesocricetus; Mouth Neoplasms; Papilloma; Phenotype; Transcriptome; Transplantation, Homologous

Metaplastic carcinomas arising in association with benign sclerosing lesions (BSLs) are rare malignancies in which a neoplastic spindle cell proliferation can be recognized extending beyond the boundaries of the complex sclerosing lesion or papilloma. However, in cases in which the metaplastic carcinoma is of the low-grade fibromatosis-like type or is a low-grade adenosquamous carcinoma, distinction from the background BSL can be a significant challenge. Cytokeratin (CK) and/or p63 immunostains are helpful in confirming the diagnosis of metaplastic carcinoma, but the expression patterns of these markers in the stromal cells of BSLs have not been well characterized.. To characterize the expression patterns of CKs and p63 in BSLs.. We evaluated the spindle cell component of 55 BSLs using CK 5/6, CK 903, CK MNF116, and p63.. A total of 45 cases (81%) showed no staining for CKs or p63 in benign stromal cells. CK 5/6, CK 903, and p63 were positive in one case each. CK MNF116 stained spindle cells within 10 BSLs. No cases showed spindle cell reactivity for all 4 markers. Positive cases demonstrated very focal, weak staining of spindle cells; only 1 case showed focal, moderate CK staining. Spindle cell positivity was not associated with lesion type, growth pattern, spindle cell atypia, or mitoses.. These findings suggest that although the presence or absence of expression of CK 5/6, CK 903, and p63 may be useful to distinguish BSL from metaplastic carcinomas arising in this setting, CK MNF116 positivity may be a diagnostic pitfall.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Breast; Breast Neoplasms; Female; Humans; Immunohistochemistry; Keratins; Metaplasia; Middle Aged; Papilloma; Sclerosis; Stromal Cells; Transcription Factors; Tumor Suppressor Proteins; Young Adult

Luminal cytokeratin (CK) expression in breast papillary lesions, and its potential diagnostic utility among other markers in distinguishing between papillomas and papillary carcinomas, has not been previously evaluated. Such expression was determined in 42 papillary lesions (18 papillary carcinomas and 24 papillomas) by immunostaining with a CK5/p63/CK8/18 antibody cocktail. The mean CK8/18 intensity score and percentage of positive cells were significantly higher in papillary carcinomas (227 and 95%, respectively, vs 86 and 42% in papillomas; both P-values <0.0001), whereas the mean CK5 intensity score and percentage of positive cells were significantly lower (7 and 5%, respectively, vs 107 and 58% in papillomas; both P-values <0.0001). Half (9/18) of the papillary carcinomas expressed p63 vs all (24/24) of the papillomas (P = 0.0001). P63 expression in papillary carcinoma was always (9/9; 100%) focal/limited in nature (expression in <10% of cells), whereas focal expression was seen in only four (17%) papillomas (P<0.0001). Both differential CK (CK8/18 and CK5) expression and p63 were equally sensitive (100%) for the diagnosis of papillary carcinoma, but differential CK expression was more specific (96 vs 83%), resulting in a greater accuracy. However, the best discriminatory power in the distinction from papilloma was achieved when all three markers were used in combination, resulting in 100% sensitivity and specificity values. It is concluded that breast papillary lesions have differential CK expression profiles that, especially in combination with p63, can be useful for their stratification, potentially also in needle biopsy material, in which more accurate and reproducible characterization is needed.

Topics: Adult; Biomarkers, Tumor; Breast Neoplasms; Carcinoma, Papillary; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Keratins; Membrane Proteins; Papilloma; Sensitivity and Specificity

Ligand activation of peroxisome proliferator-activated receptor (PPAR)-beta/delta and inhibition of cyclooxygenase-2 (COX-2) activity by nonsteroidal anti-inflammatory drugs can attenuate skin tumorigenesis. There is also evidence that attenuation of skin tumorigenesis by inhibition of COX-2 activity occurs through PPARbeta/delta-independent mechanisms. The present study examined the hypothesis that combining ligand activation of PPARbeta/delta with inhibition of COX-2 activity will cooperatively inhibit chemically induced skin tumor progression using both in vivo and ex vivo models. A two-stage chemical carcinogenesis bioassay was performed in wild-type and Pparbeta/delta-null mice. After 22 weeks, cohorts of both mouse lines were divided into four experimental groups: (1) control, (2) topical application of the PPARbeta/delta ligand GW0742, (3) dietary administration of the COX-2 inhibitor nimesulide, or (4) both GW0742 and nimesulide. Ligand activation of PPARbeta/delta did not influence skin tumor progression, while a modest decrease in skin tumor multiplicity was observed with dietary nimesulide. Interestingly, the combined treatment of GW0742 and nimesulide increased the efficacy of the decrease in papilloma multiplicity for 6 weeks in wild-type mice, but this effect was not found at later time points and was not found in similarly treated Pparbeta/delta-null mice. Neoplastic keratinocyte lines cultured with GW0742 and nimesulide also exhibited enhanced inhibition of cell proliferation coincident with increased expression of Keratin messenger RNAs. Results from these studies support the hypothesis that combining ligand activation of PPARbeta/delta with inhibition of COX-2 activity can inhibit chemically induced skin tumor progression by modulating differentiation.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Anticarcinogenic Agents; Carcinoma, Squamous Cell; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cyclooxygenase 2 Inhibitors; Dinoprostone; Disease Models, Animal; Female; Keratinocytes; Keratins; Keratoacanthoma; Ligands; Mice; Mice, Inbred C57BL; Mice, Knockout; Papilloma; PPAR delta; PPAR-beta; RNA, Messenger; Skin Neoplasms; Sulfonamides; Thiazoles; Time Factors

Topics: Adenocarcinoma; Aged; Biomarkers, Tumor; Breast Neoplasms; Carcinoma, Intraductal, Noninfiltrating; Carcinoma, Papillary; Cell Nucleus; Diagnosis, Differential; Female; Humans; Hyperplasia; Keratins; Membrane Proteins; Neoplasm Proteins; Neoplasms, Multiple Primary; Papilloma

The pathogenesis of respiratory epithelial adenomatoid hamartoma (REAH) and inverted papilloma (IP) is poorly understood, especially compared with sinonasal adenocarcinoma (SNAC). One feature of malignant glandular lesions is loss of the basal/myoepithelial layer. The immunophenotype of the basal/myoepithelial layer has not been fully examined in benign glandular lesions of the sinonasal tract.. To examine benign and malignant glandular lesions in the sinonasal tract for the immunophenotype of basal/myoepithelial cells, proliferation index, and cytokeratin and intestinal differentiation profiles.. Sinonasal adenocarcinoma (intestinal-type adenocarcinoma [ITAC] and nonintestinal type adenocarcinoma [non-ITAC]), REAH, IP, and chronic sinusitis (CS) were stained for cytokeratin (CK) 7, CK20, 34betaE12, CDX-2, p63, Ki-67, smooth muscle actin (SMA), S100 protein, and calponin.. Basal/myoepithelial cells in CS and REAH were positive for p63 and 34betaE12 but negative for SMA, S100 protein, and calponin. Proliferative activity was localized to the compartment containing p63-positive cells. Inverted papilloma demonstrated broad areas staining for p63 and 34betaE12, with intermediate proliferative activity in these areas. Sinonasal adenocarcinoma had the highest Ki-67 labeling index, and p63-positive SNACs had higher proliferation indices than p63-negative SNACs. REAH, IP, CS, and most SNACs expressed CK7. Only SNAC expressed CK20. Sixty percent of morphologic ITACs expressed CDX-2.. Basal/myoepithelial cells in CS and REAH should be considered basal and not myoepithelial cells. In benign lesions, proliferative activity is limited to the compartments with p63 staining. In SNAC and IP, p63 expression correlates with proliferation index. REAH, IP, and CS share similar immunoprofiles (CK7+, CK20-, and CDX-2-), contrasting with SNAC (CK7+, CK20+/-, CDX-2-/+).

Topics: Actins; Adenocarcinoma; Biomarkers, Tumor; Calcium-Binding Proteins; Calponins; CDX2 Transcription Factor; Cell Proliferation; Chronic Disease; Diagnosis, Differential; Epithelial Cells; Female; Hamartoma; Homeodomain Proteins; Humans; Immunohistochemistry; Immunophenotyping; Keratins; Ki-67 Antigen; Male; Membrane Proteins; Microfilament Proteins; Middle Aged; Papilloma; Paranasal Sinus Neoplasms; S100 Proteins; Sinusitis; Trans-Activators

PTEN tumor suppressor gene failure in ras(Ha)-activated skin carcinogenesis was investigated by mating exon 5 floxed-PTEN (Delta5PTEN) mice to HK1.ras mice that expressed a RU486-inducible cre recombinase (K14.creP). PTEN inactivation in K14.cre/PTEN(flx/flx) keratinocytes resulted in epidermal hyperplasia/hyperkeratosis and novel 12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted papillomas, whereas HK1.ras/K14.cre/PTEN(flx/flx) cohorts displayed a rapid onset of papillomatogenesis due to a synergism of increased AKT activity and extracellular signal-regulated kinase (ERK) elevation. High 5-bromo-4-deoxyuridine labeling in Delta5PTEN papillomas showed that a second promotion mechanism centered on failures in cell cycle control. Elevated cyclin D1 was associated with both HK1.ras/ERK- and Delta5PTEN-mediated AKT signaling, whereas cyclin E2 overexpression seemed dependent on PTEN loss. Spontaneous HK1.ras/Delta5PTEN malignant conversion was rare, whereas TPA promotion resulted in conversion with high frequency. On comparison with all previous HK1.ras carcinomas, such TPA-induced carcinomas expressed atypical retention of keratin K1 and lack of K13, a unique marker profile exhibited by TPA-induced K14.cre/PTEN(flx/flx) papillomas that also lacked endogenous c-ras(Ha) activation. Moreover, in all PTEN-null tumors, levels of ras(Ha)-associated total ERK protein became reduced, whereas phosphorylated ERK and cyclin D1 were lowered in late-stage papillomas returning to elevated levels, alongside increased cyclin E2 expression, in TPA-derived carcinomas. Thus, during early papillomatogenesis, PTEN loss promotes ras(Ha) initiation via elevation of AKT activity and synergistic failures in cyclin regulation. However, in progression, reduced ras(Ha)-associated ERK protein and activity, increased Delta5PTEN-associated cyclin E2 expression, and unique K1/K13 profiles following TPA treatment suggest that PTEN loss, rather than ras(Ha) activation, gives rise to a population of cells with greater malignant potential.

Topics: Animals; Carcinogens; Cell Differentiation; Cell Transformation, Neoplastic; Keratin-13; Keratins; MAP Kinase Signaling System; Mice; Mice, Transgenic; Mifepristone; Oncogene Protein v-akt; Papilloma; PTEN Phosphohydrolase; ras Proteins; Skin Neoplasms; Tetradecanoylphorbol Acetate; Up-Regulation

Recent studies have suggested that benign papillary lesions without atypia [benign papilloma (BP)] diagnosed on breast core needle biopsy (CNB) may not require excision. However, most have studied only small numbers of cases and scant data are available on the utility of immunohistochemistry in the categorization of papillary lesions on CNB. In the largest published series of BP identified on CNB, we studied the impact of immunohistochemistry on the accuracy of a CNB diagnosis of BP.. Breast CNBs (n = 129) with a diagnosis of papillary lesion were immunostained for calponin, p63 and cytokeratin 5/6. Haematoxylin and eosin and immunostained slides were independently reviewed by four breast pathologists. BP was the final excision diagnosis in 35 cases. With the use of immunohistochemistry, the positive predictive value (PPV) of BP diagnosis by the four individual pathologists increased from 72.7-83.3% (mean 79.2%) to 77.8-87.5% (82.1%), the negative predictive value (NPV) increased from 77.8-98.5% (88.6%) to 100% for all four participants and overall accuracy increased from 78.7-92.6% (84.7%) to 90.7-95.4% (92.8%). No case of invasive carcinoma was diagnosed as BP on CNB by any participant. The frequency of ductal carcinoma in situ following a BP diagnosis on CNB ranged from 2.5% to 4.8% (4%) but was only 0-3% (2.3%) after excluding cases that were radiologically suspicious for malignancy.. Immunohistochemistry increases accuracy of BP diagnosis in CNB specimens. Benign papillary lesions diagnosed on CNB do not require excision in the absence of suspicious clinical/radiological findings.

Topics: Adult; Aged; Aged, 80 and over; Biopsy, Needle; Breast; Breast Diseases; Breast Neoplasms; Calcium-Binding Proteins; Calponins; Diagnosis, Differential; DNA-Binding Proteins; Female; Humans; Immunohistochemistry; Keratin-5; Keratin-6; Keratins; Microfilament Proteins; Middle Aged; Observer Variation; Papilloma; Precancerous Conditions; Reproducibility of Results; Trans-Activators; Transcription Factors; Tumor Suppressor Proteins

Paratesticular cysts with benign epithelial proliferations (BEPs) are rare. Only 10 cases were found in a series of 431 paratesticular cysts and were classified as follows: cystadenoma, 5; papilloma, 2; and hamartoma, 3. Four cystadenomas showed multiple papillae lined by CD10+ epithelial cells with hyperchromatic nuclei. The remaining lesion showed areas with a microcystic, glandular, cribriform pattern, with small, benign glands without atypia. Urothelial papilloma presented BEPs with cytokeratin (CK) 7+ and CD10+ and CK20- umbrella-like cells. The mural papilloma was lined by proliferative cylindrical cells exhibiting strong CK7 and CD10 expression. The 3 Wolffian hamartomas were characterized by strongly CD10+ epithelium surrounded by smooth muscle cells. The consistent CD10 expression in BEPs of paratesticular cysts suggests a Wolffian origin. The differential diagnosis of paratesticular cysts with BEP vs metastatic prostatic and primary borderline or malignant tumors is discussed.

Topics: Adolescent; Adult; Aged; Cystadenoma, Papillary; Cysts; Diagnosis, Differential; Epithelium; Hamartoma; Humans; Immunohistochemistry; Intermediate Filament Proteins; Keratin-20; Keratin-7; Keratins; Male; Mesonephros; Middle Aged; Neprilysin; Papilloma; Testicular Diseases

Cytokeratins (CKs) are the intermediate filament proteins of the epithelium cells, which have become important markers of normal and abnormal cell differentiation. The goal of the present study was to investigate the expression pattern of CK 10, 13, 14 and 16 in oral verrucous carcinoma (OVC) and oral squamous papilloma (OSP).. Formalin-fixed paraffin-embedded sections from eight cases of each lesion were assessed. Immunohistochemistry was carried out using streptoavidin-biotin complex method.. In OVC, CK 10 was expressed in suprabasal to superficial layers whereas in OSP mainly in superficial layer. CK 13 was detected in prickle and superficial cells in most cases of OVC and in suprabasal to superficial cells of OSP. All the cell layers of OVC reacted positively for CK 14 while basal and suprabasal layers of OSP were more pronounced for CK 14. Finally, CK 16 was observed in suprabasal to superficial layer in OVC and the majority cases in OSP showed only superficial reactive cells.. CK 10, 13, 14 and 16 immunohistochemical profile emphasis the biological behavior of the studied lesions and confirm the use of these proteins as markers of differentiation.

Topics: Carcinoma, Verrucous; Cell Proliferation; Cell Transformation, Neoplastic; Humans; Immunohistochemistry; Intermediate Filament Proteins; Keratinocytes; Keratins; Mouth Neoplasms; Papilloma

Genetically engineered mouse models with altered oncogene or tumor suppressor gene activity have been utilized recently for carcinogen identification. The v-rasHa transgenic Tg.AC mouse, with its enhanced susceptibility to skin tumorigenesis, is thought to be well suited for examining the carcinogenicity of topically applied agents. Tg.AC mice were used to examine the carcinogenicity of SEPA 0009, a rationally designed organic molecule designed to enhance drug penetration through the skin. Fifty mg SEPA 0009/kg body weight, 1500 mg SEPA 0009/kg body weight, or the vehicle alone was applied daily to the skin of Tg.AC mice. Nontransgenic FVB/N mice were also treated with the vehicle alone or 1500 mg SEPA 0009. Daily application of a high-dose of SEPA 0009 caused severe and chronic irritation by 1 week that was maintained throughout the experiment. The irritation was accompanied by increased proliferation, increased apoptosis, and expression of the wound-associated keratin 6. High-dose SEPA 0009 induced squamous papillomas in Tg.AC, but not in nontransgenic mice, by 6 weeks. In mice treated with the high dose SEPA 0009, transgene expression was detected in papillomas at week 9, well after the onset of skin irritation and hyperplasia. In contrast, low-dose SEPA 0009 was not irritating to the skin and did not induce papillomas. Thus, SEPA 0009-induced tumorigenesis was associated with chronic and severe irritation. We propose that SEPA 0009-induced tumorigenesis in Tg.AC mice proceeds through an indirect mechanism that is secondary to cutaneous irritation.

Topics: Animals; Carcinogenicity Tests; Carcinogens; Cell Death; Cell Proliferation; Dermatitis, Irritant; Dioxolanes; Dose-Response Relationship, Drug; Epidermis; Female; Gene Expression; Genes, ras; Hyperplasia; Keratin-6; Keratinocytes; Keratins; Mice; Mice, Transgenic; Papilloma; Precancerous Conditions; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate; Time Factors

Topics: Adenoma, Sweat Gland; Diagnosis, Differential; Humans; Keratin-14; Keratin-17; Keratin-18; Keratin-7; Keratins; Papilloma; Sebaceous Gland Neoplasms; Skin Neoplasms; Sweat Gland Neoplasms

Mouse models for cancer represent powerful tools to analyze the causal role of genetic alterations in cancer development. We have developed a novel mouse model that allows the focal activation of mutations in stratified epithelia. Using this system, we demonstrate that activation of an oncogenic K-rasG12D allele in the oral cavity of the mouse induces oral tumor formation. The lesions that develop in these mice are classified as benign squamous papillomas. Interestingly, these tumors exhibit changes in the expression pattern of keratins similar to those observed in human premalignant oral tumors, which are reflective of early stages of tumorigenesis. These results demonstrate a causal role for oncogenic K-ras in oral tumor development. The inducible nature of this model also makes it an ideal system to study cooperative interactions between mutations in oncogenes and/or tumor suppressor genes that are similar to those observed in human tumors. To our knowledge, this is the first reported inducible mouse model for oral cancer.

Topics: Animals; Blotting, Western; Carcinoma, Squamous Cell; Epithelial Cells; Fluorescent Antibody Technique; Gene Expression Regulation, Neoplastic; Genes, ras; Keratins; Mice; Mice, Knockout; Mouth Neoplasms; Mutation; Oncogene Protein p21(ras); Papilloma; Polymorphism, Restriction Fragment Length; Precancerous Conditions; Reverse Transcriptase Polymerase Chain Reaction

Keratin 10 (K10) is the major protein in the upper epidermis where it maintains keratinocyte integrity. Others have reported that K10 may act as a tumor suppressor upon ectopic expression in mice. Although K10(-/-) mice show significant epidermal hyperproliferation, accompanied by an activation of the mitogen-activated protein kinase (MAPK) pathway, they formed no spontaneous tumors. Here, we report that K10(-/-) mice treated with 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) developed far less papillomas than wild-type mice. BrdU(5-bromo-2'-deoxyuridine)-labeling revealed a strongly accelerated keratinocyte turnover in K10(-/-) epidermis suggesting an increased elimination of initiated keratinocytes at early stages of developing tumors. This is further supported by the absence of label-retaining cells 18 d after the pulse whereas in wild-type mice label-retaining cells were still present. The concomitant increase in K6, K16, and K17 in K10 null epidermis and the increased motility of keratinocytes is in agreement with the pliability versus resilience hypothesis, stating that K10 and K1 render cells more stable and static. The K10(-/-) knockout represent the first mouse model showing that loss of a keratin, a cytoskeletal protein, reduces tumor formation. This is probably caused by an accelerated turnover of keratinocytes, possibly mediated by activation of MAPK pathways.

Topics: Animals; Cell Division; Epidermal Cells; Epidermis; Female; Integrin alpha6; Keratin-10; Keratinocytes; Keratins; MAP Kinase Signaling System; Mice; Mice, Inbred BALB C; Mice, Knockout; Papilloma; Skin Neoplasms

Immunohistochemistry for uroplakin III (UP III), cytokeratin 7 (CK 7), and cytokeratin 20 (CK 20) using commercially available antibodies was done in normal canine urinary bladder and 72 canine urinary bladder tumors that had been fixed in formalin and embedded in paraffin. Prolonged fixation (3-28 days) did not significantly alter the immunostaining for UP III. There was moderate reduction in the intensity for CK 7 and CK 20 after 1 week of fixation. UP III was detected in superficial (umbrella) cells and some intermediate cells of the normal urinary bladder, 7 of 7 transitional cell papillomas (TCPs), 50 of 55 transitional cell carcinomas (TCCs), and 4 of 5 metastatic TCCs. Staining was typically outlined in the plasma membrane, but diffuse or focal cytoplasmic staining was also observed. Intracytoplasmic lumina were usually positive for UP III. One squamous cell carcinoma of the bladder, 4 nonepithelial bladder tumors, and 285 nonurothelial tumors from different nonurinary locations were negative for UP III. CK 7 was detected in 7 of 7 TCPs, 53 of 54 TCCs, and 5 of 5 metastatic TCCs. The staining for CK 7 was diffuse cytoplasmic. CK 20 was detected in 1 of 7 TCPs, 37 of 54 TCCs, and 1 of 5 metastatic TCCs. The staining with CK 20 was cytoplasmic and weaker than with antibodies to UP III or CK 7. There was concurrent expression of UP III, CK 7, and CK 20 in 36 of 54 TCCs. UP III is a specific and sensitive marker for canine transitional epithelial (urothelial) neoplasms, detecting 91% of TCCs. Negative results may be observed with anaplastic tumors.

Topics: Animals; Carcinoma, Transitional Cell; Dog Diseases; Dogs; Immunohistochemistry; Intermediate Filament Proteins; Keratin-20; Keratin-7; Keratins; Membrane Glycoproteins; Papilloma; Tissue Fixation; Urinary Bladder Neoplasms; Uroplakin III; Urothelium

Enhancing factor (EF), a growth factor modulator, is the mouse homologue of human secretory group II phospholipase A(2). EF exhibits growth-promoting activity in vitro, in the presence of epidermal growth factor, and also brings about phenotypic transformation of normal cells. In order to ascertain the role of EF in vivo, a human keratin-14 promoter was used to drive the expression of EF ectopically to squamous epithelial cells. The founder mouse and its progeny showed abnormal whiskers and a scaly, beaded tail. In these mice, keratinization pattern of the epidermis was disturbed and parakeratosis and acanthosis were noted. The transgenic mice, TgK14-EF, expressed EF in the suprabasal layers of tail epidermis as well as in the epithelial cells of hair follicle and sebaceous glands of skin. Expression of EF along with hyperplasia was also observed in other squamous epithelia such as buccal mucosa, tongue and oesophagus. TgK14-EF mice homozygous for the transgene showed delayed and scanty hair growth although the mice were healthy and fertile. The hemizygous TgK14-EF mice were sensitive to a two-stage chemical carcinogenesis and developed a higher number of papillomas than their normal littermates over the course of the experiment. The conversion rate of papilloma to carcinoma was two fold higher in the transgenic mice.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Abnormalities, Multiple; Animals; Carcinogens; Carcinoma, Squamous Cell; Epidermis; Fibrosarcoma; Genetic Predisposition to Disease; Genotype; Group II Phospholipases A2; Humans; Keratins; Mice; Mice, Transgenic; Neoplasms, Basal Cell; Papilloma; Phenotype; Phospholipases A; Promoter Regions, Genetic; Recombinant Fusion Proteins; Skin; Skin Neoplasms; Tail; Tetradecanoylphorbol Acetate; Transgenes; Vibrissae

12-O-Tetradecanoylphorbol-13-acetate (TPA) was applied to the back skin of v-Ha-ras (TG-AC) female transgenic mice at a dose of 2.5 microg/200 microl twice a week for 9 weeks. The back skin was then exposed to blue light (wavelength, 470 nm; irradiance, 5.7 mW/cm2) for 1 h daily for 9 weeks. The mice to which TPA was applied developed skin tumors at 6 weeks after the start of application. The tumor incidence rates at 6, 7, 8 and 9 weeks after the start of application were 70%, 80%, 100% and 100%, respectively, and the numbers of tumors 1 mm or more in diameter were 1, 5, 10 and 19, respectively. In the mice that were exposed to blue light after TPA application, the tumor incidence rates were 10%, 40%, 60% and 80%, respectively, and the numbers of tumors 1 mm or more in diameter were 0, 2, 5 and 9, respectively. Histopathological examination of the skin revealed that TPA application induced diffuse hyperplasia, exaggerated keratinization, and papillomas in all 10 mice. A localized form of epidermal hyperplasia was also observed in 4 mice. The incidence rate of papillomas in the mice that were exposed to blue light after TPA application was lower and the degree of exaggerated keratinization was greater. Exaggerated keratinization was considered to represent a regressive change following exposure. These findings suggest that exposure to blue light may be a promising new approach in the treatment of skin tumors.

Topics: Animals; Epidermis; Female; Genes, ras; Hyperplasia; Keratins; Mice; Mice, Transgenic; Oncogene Protein p21(ras); Papilloma; Phototherapy; Precancerous Conditions; Recombinant Fusion Proteins; Skin Diseases; Skin Neoplasms; Tetradecanoylphorbol Acetate; Weight Gain

Tumor promoters such as the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) are proinflammatory agents, and their mechanism of action in epithelial carcinogenesis has been linked to the release of IL-1 alpha and the induction of chronic inflammation in skin. To test the role of IL-1 alpha and inflammation in models of cutaneous carcinogenesis, we used our previously described FVB/N transgenic mice overexpressing 17-kDa IL-1 alpha in the epidermis under the keratin 14 (K14) promoter. Strikingly, the K14/IL-1 alpha mice were completely resistant to papilloma and carcinoma formation induced by a two-stage DMBA/TPA protocol, while littermate controls developed both tumor types. K14/IL-1 alpha mice crossed with the highly sensitive TG.AC mice, constitutively expressing mutant Ha-Ras, also failed to develop papillomas or carcinomas. When the K14/IL-1 alpha transgene was bred onto a recombinase-activating gene-2-deficient background, the resistance persisted, indicating that innate, but not acquired, mechanisms may be involved in the resistance to the initiation/promotion model. As an alternative approach, a complete carcinogenesis protocol using repetitive application of DMBA alone was applied. Surprisingly, although the IL-1 alpha mice still did not develop papillomas, they did develop carcinomas de novo at an accelerated rate compared with controls. We conclude that constitutive IL-1 alpha expression rendered FVB mice completely resistant to carcinomas that required evolution from prior papillomas, but facilitated carcinomas that did not evolve from papillomas, as in the complete carcinogenesis protocol. Thus, the role of IL-1 alpha and, by extension that of other proinflammatory factors, in epithelial carcinogenesis are more complex than previously appreciated. These mice may provide a mechanism to investigate the validity of these models of human skin tumorigenesis.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinogens; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; DNA-Binding Proteins; Epidermis; Female; Humans; Immunity, Innate; Interleukin-1; Keratin-14; Keratins; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Nuclear Proteins; Papilloma; Skin Neoplasms; Tetradecanoylphorbol Acetate; Transgenes

Glucocorticoids are effective inhibitors of epidermal proliferation and skin tumorigenesis. Glucocorticoids affect cellular functions via glucocorticoid receptor (GR), a well-known transcription factor. Recently, we generated skin-targeted transgenic mice overexpressing GR under control of the keratin5 promoter (K5-GR mice). To test the hypothesis that GR plays a role as a tumor suppressor in skin, we bred K5-GR transgenic mice with Tg.AC transgenic mice, which express v-Ha-ras oncogene in the skin, and compared the susceptibility of F1 offspring to TPA-induced skin carcinogenesis. GR overexpression in the epidermis dramatically inhibited skin tumor development. In K5-GR/ras+ double transgenic mice papillomas developed later and the average number of tumors per animal was 15% (in males) and 40% (in females) of the number seen in wild type (w.t./ras+) littermates. In addition, the papillomas in w.t./ras+ animals were eight to nine times larger. GR overexpression resulted in a decrease in keratinocyte proliferation combined with a modest increase in apoptosis and differentiation of keratinocytes in K5-GR/ras+ papillomas. Our data clearly indicate that interference of GR transgenic protein with nuclear factor kappa B (NF-kappaB) transcription factor had resulted in NF-kappaB blockage in K5-GR/ras+ tumors. We discuss the role of NF-kappaB blockage in tumor-suppressor effect of GR.

Topics: Animals; Apoptosis; Cell Differentiation; Cell Division; Epidermis; Female; Keratin-15; Keratin-5; Keratinocytes; Keratins; Mice; Mice, Transgenic; NF-kappa B; Oncogene Protein p21(ras); Papilloma; Receptors, Glucocorticoid; Skin Neoplasms; Tumor Suppressor Proteins

Susceptibility to tumor development varies among individuals in the human population. This variability can also be found among different strains of mice, particularly in the mouse skin chemical carcinogenesis model. The genetic mechanisms underlying mouse skin tumor susceptibility are not fully understood. The SENCAR stock has been found to be the most sensitive mice for skin carcinogenesis studies; however, little is known about the genes underlying tumor susceptibility, particularly, those involved in tumor progression. Experiments with the SSIN/Sprd mice, an inbred strain derived from the outbred SENCAR stock, suggested that papilloma development, tumor promotion, and their conversion into squamous cell carcinomas (SCCs), progression, are regulated by different genes. In the highly sensitive SSIN/Sprd mice, papillomas rarely progress to SCC. Using crosses between the outbred SENCAR and the SSIN/Sprd mice, we previously determined that papilloma progression in the SENCAR stock could be controlled by at least one autosomal dominant gene. However, the outbred nature of the SENCAR stock precluded us from extending those findings. More recently, another inbred strain was developed from the outbred SENCAR stock, the SENCARB/Pt. These mice have similar tumor promotion sensitivity to the SSIN/Sprd but in contrast, have high papilloma progression susceptibility, similar to the outbred original stock. In the present study, we generated F(1), F(2), and backcross hybrids between the SSIN/Sprd and SENCARB/Pt mice to determine a possible model for tumor progression susceptibility and to map the putative tumor susceptibility genes. Our tumor data suggests that papilloma progression susceptibility in the SENCAR mouse skin model could be genetically determined by one susceptibility gene. Our preliminary linkage analysis failed to identify one strong susceptibility locus to confirm this but provided some evidence for at least one possible susceptibility locus in mouse chromosome 14.

Topics: Animals; Carcinoma, Squamous Cell; Chimera; Chromosome Mapping; Chromosomes; Crosses, Genetic; Disease Progression; Genetic Linkage; Genetic Markers; Genetic Predisposition to Disease; Incidence; Keratins; Mice; Mice, Inbred SENCAR; Papilloma; Skin Neoplasms

The most common benign lesion of thyroid, multinodular goiter, may mimic papillary carcinoma if it contains papillary areas. Although it is usually not very difficult to distinguish between these benign and malignant lesions, some cases may be problematic in differential diagnosis. In these cases, we decided to use cytokeratin 19 (CK19), which is shown to be effective in discriminating papillary carcinoma from follicular carcinoma of thyroid, and we also evaluated the immunoreactivity of CK19 in follicular adenomas. Twenty-five cases of multinodular goiter showing papillary formations, 25 cases of papillary thyroid carcinoma, and 15 cases of follicular adenoma were selected from archives of our institution. Immunohistochemical staining for CK19 was performed on deparaffinized sections. Diffuse and intense CK19 positivity was found in the cells of all papillary carcinomas. In the multinodular goiter group, 20 of 25 cases showed no staining while the remaining 5 were focally reactive with CK19. Three of the five were thought to be false positive owing to hemorrhage. Weak and focal CK19 staining was seen in some follicular adenomas. Our observations suggest that the staining features of CK19 may be helpful in differential diagnosis between papillary carcinoma and multinodular goiter showing papillary areas. Focal and pale staining for CK19 may be seen in multinodular goiter with papillary formations, and this feature should be considered in evaluation.

Topics: Adenocarcinoma, Papillary; Adolescent; Adult; Aged; Biomarkers, Tumor; Diagnosis, Differential; Female; Goiter, Nodular; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Papilloma

Telomerase transgenics are an important tool to assess the role of telomerase in cancer, as well as to evaluate the potential use of telomerase for gene therapy of age-associated diseases. Here, we have targeted the expression of the catalytic component of mouse telomerase, mTERT, to basal keratinocytes using the bovine keratin 5 promoter. These telomerase-transgenic mice are viable and show histologically normal stratified epithelia with high levels of telomerase activity and normal telomere length. Interestingly, the epidermis of these mice is highly responsive to the mitogenic effects of phorbol esters, and it is more susceptible than that of wild-type littermates to the development skin tumors upon chemical carcinogenesis. The epidermis of telomerase-transgenic mice also shows an increased wound-healing rate compared with wild-type littermates. These results suggest that, contrary to the general assumption, telomerase actively promotes proliferation in cells that have sufficiently long telomeres and unravel potential risks of gene therapy for age-associated diseases based on telomerase upregulation.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Catalytic Domain; Cattle; DNA-Binding Proteins; Female; Gastric Mucosa; Genes, p53; Genetic Therapy; Hyperplasia; Keratinocytes; Keratins; Mice; Mice, Knockout; Mice, Transgenic; Mouth Mucosa; Neoplasms, Experimental; Papilloma; Protein Subunits; RNA; Skin; Skin Neoplasms; Stomach; Telomerase; Telomere; Tetradecanoylphorbol Acetate; Vagina; Wound Healing

The distribution of cytokeratins (CKs) and vimentin in the normal genital tract of calves and cows at different stages of the oestrous cycle and in epithelial tumours of the tract was studied immunohistochemically. Few differences in CK and vimentin immunolabelling were detected in relation to age or stage of the oestrous cycle. Coexpression of CKs in simple epithelia and in basal cells of stratified epithelia was detected in the oviduct and endocervix; this coexpression was different from that previously described in women. The demonstration of CKs but not vimentin in the neoplastic cells of a serous superficial ovarian papilloma suggested an origin from the ovarian surface epithelium, while the coexpression of CKs and vimentin in serous papillary and mucinous cystadenomas pointed to a possible origin from the rete ovarii. Studies on three uterine adenocarcinomas and the ovarian metastases from two of these showed an endometrial-CK phenotype. The intermediate filament profile of normal endometrium, conserved in uterine adenocarcinomas and their ovarian metastases, may be useful in discriminating between ovarian metastases from endometrial carcinomas and those originating from primary carcinomas in other organs.

Topics: Adenocarcinoma; Age Factors; Animals; Antibodies, Monoclonal; Cattle; Cattle Diseases; Cystadenoma; Estrus; Female; Genitalia, Female; Immunoenzyme Techniques; Keratins; Ovarian Neoplasms; Ovary; Oviducts; Papilloma; Uterine Neoplasms; Uterus; Vimentin

In 1999, the World Health Organization (WHO) published a new classification of papillary urothelial tumors of the urinary bladder. Intended to represent a reproducible, easy-to-use classification system that better separates patients with true malignancies (bladder cancer) from those patients who are at an increased risk for developing bladder cancer, problems in the differential diagnosis of various lesions remained. Probably the most critical distinction is between papillomas, papillary urothelial neoplasms of low malignant potential (lmp), and grade I papillary carcinomas. Conversely, problems in the distinction between reactive atypia, atypia of unknown significance, and dysplasia, as well as the distinction of dysplasia from carcinoma in situ (CIS), are unresolved. Whether urothelial basal cell status assessment on hematoxylin and eosin-stained slides completed by cytokeratin immunohistochemistry with anticytokeratin clone 34betaE12 may help to improve some of the previously mentioned diagnostic dilemmas was investigated. Basal cell status assessment was helpful in the differentiation between dysplasia and CIS. In dysplasia, CK IHC showed a predominantly basal labeling pattern, whereas in CIS, labeling of all urothelial layers was seen. Basal cell status assessment could separate 2 groups of pTa GIb papillary carcinoma. Group 1 with a continuous basal CK labeling and a low MIB-1 labeling index (LI) was compared with group 2, with a diffuse labeling pattern and a significantly higher MIB-1 LI. Whether group 1 carcinomas should better be assigned to the group of papillary urothelial neoplasms of lmp is discussed.

Topics: Antigens, Nuclear; Biopsy; Carcinoma, Papillary; Diagnosis, Differential; Humans; Hyperplasia; Immunohistochemistry; Keratins; Ki-67 Antigen; Nuclear Proteins; Papilloma; Urinary Bladder Neoplasms; Urothelium; World Health Organization

Alternative models using fish species have been tested in liver toxicity and carcinogenesis bioassays. Similar models have not been developed for skin. The brown bullhead (Ameiurus nebulosus) has shown potential as a model for skin carcinogenesis studies due to its sensitivity to environmental chemical pollutants. The present study is an initial morphologic and biochemical characterization of the normal and neoplastic brown bullhead skin to assess its suitability as a model of skin carcinogenesis. Brown bullhead were removed from Back River in the Chesapeake Bay region, an area historically polluted with heavy metals and polycyclic aromatic hydrocarbons. Histology, histochemistry, and electron microscopy were used to stage the morphologic development and progression of neoplasia in skin. The distribution of keratin, a family of structural proteins with altered expression in mammalian tumorigenesis, was analyzed with one and two dimensional gel electrophoresis and nitrocellulose blots of extracts from normal skin. Keratin expression in skin and other organs was also assessed with immunohistochemistry using AE1, AE3, and PCK 26 antibodies, and the proliferation index in skin and neoplasms with PCNA antibody. Skin lesions appeared to progress from hyperplasia through carcinoma, and the proliferation index was increased in papilloma. Also in papilloma, intercellular interdigitations appeared increased and desmosomes decreased which may in future studies correlate with changes in expression of other molecular markers of neoplastic progression. Both Type I and Type II keratin subfamilies were detected in skin using gel electrophoresis with the complimentary keratin blot-binding assay. For further development of the brown bullhead model, future studies can compare and relate these baseline data to alterations in expression of keratin and other markers in fish neoplasms and to molecular events which occur in man.

Topics: Animals; Carcinogenicity Tests; Electrophoresis, Polyacrylamide Gel; Epithelium; Fishes; Histocytochemistry; Hydrocarbons, Aromatic; Hyperplasia; Keratins; Lip; Metals, Heavy; Microscopy, Electron; Papilloma; Proliferating Cell Nuclear Antigen; Skin Neoplasms; Water Pollutants, Chemical

The erbB family of receptor tyrosine kinases, which consists of the epidermal growth factor receptor (EGFr/erbB1), erbB2 (neu), erbB3 and erbB4, has been shown to be important for both normal development as well as neoplasia. The expression of rat erbB2 was targeted to the basal layer of mouse epidermis with the bovine keratin 5 promoter. Overexpression of wild type rat erbB2 in the basal layer of epidermis led to alopecia, follicular hyperplasia and sebaceous gland enlargement as well as hyperplasia of the interfollicular epidermis. Spontaneous papillomas, some of which converted to squamous cell carcinomas, arose in homozygous erbB2 transgenic mice as early as 6 weeks of age with >90% incidence by 6 months. Analysis of several proliferation/differentiation markers indicated that erbB2 overexpression led to epidermal hyperproliferation and a possible delay in epidermal differentiation. Transgenic mice were also hypersensitive to the proliferative effects of the skin tumor promoter, 12-0-tetradecanoylphorbol-13-acetate (TPA) and were more sensitive to two-stage carcinogenesis. Elevations in EGFr and erbB2 protein as well as erbB2:EGFr and erbB2:erbB3 heterodimers were observed in skin of the erbB2 transgenic mice. Phosphotyrosine levels of the EGFr, erbB2 and erbB3 proteins were also elevated. These results indicate an important role for erbB2 signaling in epidermal growth, development and neoplasia. Oncogene (2000) 19, 4243 - 4254

Topics: Animals; Carcinogens; Carcinoma, Squamous Cell; Cattle; Cell Differentiation; Cell Division; Cell Transformation, Neoplastic; Cocarcinogenesis; Dimerization; Disease Progression; Epidermis; ErbB Receptors; Female; Gene Expression Regulation; Gene Expression Regulation, Neoplastic; Genes, erbB-2; Genes, ras; Genes, Synthetic; Hyperplasia; Keratins; Male; Mice; Mice, Inbred ICR; Mice, Transgenic; Neoplasm Proteins; Papilloma; Phosphorylation; Promoter Regions, Genetic; Protein Processing, Post-Translational; Rats; Receptor, ErbB-2; Receptor, ErbB-3; Recombinant Fusion Proteins; Signal Transduction; Skin Neoplasms; Tetradecanoylphorbol Acetate; Transgenes

To investigate the role of loss of the p53 tumor suppressor gene in skin carcinogenesis, p53 knockout (p53(-/-)) mice were mated with transgenic mice coexpressing v-Ha-ras, v-fos, or human transforming growth factor alpha (TGFalpha) exclusively in the epidermis by using human keratin 1 (HK1)-based vectors (HK1.ras/fos, HK1.ras/alpha, and HK1.fos/alpha). HK1.ras/fos and HK1.ras/alpha mice displayed epidermal hyperplasia and autonomous benign papillomas to an identical degree between p53(+/+) and p53(+/-) genotypes. However, HK1.ras/fos mice with the p53(-/-) genotype were born with papillomatous skin and died soon after birth. HK1.ras/alpha-p53(-/-) mice also exhibited an increased epidermal hyperplasia, and, similar to HK1.ras/alpha mice with p53(+/+) and p53(+/-) genotypes, these mice rapidly developed spontaneous and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced papillomas. These results are in contrast to our previous observation that, HK1.ras, HK1.fos, and HK1.TGFalpha transgenic mice with the p53(-/-) genotype display an unexpected delay in both spontaneous and TPA-promoted papilloma formation compared with mice with p53(+/+) and p53(+/-) genotypes. Taken collectively, our mating experiments between HK1 oncogenic transgenic mice and p53 knockout mice may identify a backup system that effectively compensates for p53 loss. Activation of multiple oncogenes not only partly overcomes such compensation but also synergizes with p53 loss. However, HK1.fos/alpha-p53(-/-) mice failed to exhibit either an increased newborn epidermal hyperplasia or an accelerated spontaneous or TPA-induced papillomas, suggesting that certain combinations of oncogenes, such as with activated Ha-ras, are required for this process. Because neither spontaneous nor TPA-elicited papillomas in p53(-/-) mice progressed to malignancy, additional genetic insults appear to be required for malignant progression.

Topics: Animals; Carcinogens; Epidermis; Female; Gene Expression Regulation; Gene Expression Regulation, Neoplastic; Genes, fos; Genes, p53; Genes, ras; Keratins; Male; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Mice, Knockout; Mice, Transgenic; Papilloma; Skin Neoplasms; Tetradecanoylphorbol Acetate; Transforming Growth Factor alpha

To be informative for chemoprevention, animal models must both closely emulate human disease and possess surrogate endpoint biomarkers that facilitate rapid drug screening. This study elucidated site-specific histopathological and biochemical surrogate endpoint biomarkers of spontaneous epidermal carcinogenesis in K14-HPV16 transgenic mice and demonstrated that the incidence and severity of these markers were decreased by the ornithine decarboxylase (ODC) inhibitor difluoromethylornithine (DFMO). The cumulative incidence of visible epidermal cancers in 127 untreated transgenic mice was 42% by 52 weeks of age, most frequently affecting the chest as flat lesions in association with chronic ulcers, or in the ear as protuberant masses. Microscopic malignancies were detected in 39% of 32-week-old transgenic mice and were found to emerge from precursor lesions that were of two distinct types: dysplastic sessile ear papillomas and hyperproliferative follicular/interfollicular chest dysplasias. ODC activity and tissue polyamine contents were differentially elevated in ear and chest skin during carcinogenesis, such that there was a marked elevation of both parameters of polyamine metabolism as early as 4 weeks of age in the ear, whereas in the chest, polyamine metabolism was increased significantly only in the late stages of neoplastic progression and in epidermal cancers. Administration of 1.0% DFMO in the drinking water from 4 to 32 weeks of age prevented both visible and microscopic malignancies and significantly decreased the incidence of chest and ear precursor lesions. ODC activity and tissue putrescine content were markedly diminished by DFMO chemoprevention in ear skin, whereas there was a more modest decline of these parameters in chest skin. DFMO treatment of transgenic mice from 28 to 32 weeks of age was associated with an absence of ear cancer and a marked regression of dysplastic papillomas. In contrast, the results in chest skin were complex in that the severity of chest precursors diminished, but their incidence was unchanged, and microscopic cancers were still detectable within these lesions. Collectively, this study highlights the utility of multistage epidermal carcinogenesis in K14-HPV16 transgenic mice both for the study of the biology of, and as a screening tool for, novel drugs and chemopreventive regimens.

Topics: Administration, Oral; Animals; Anticarcinogenic Agents; Carcinoma, Squamous Cell; Disease Progression; DNA Replication; Ear; Eflornithine; Epidermis; Gene Expression Regulation; Genes, Viral; Keratin-14; Keratins; Mice; Mice, Transgenic; Neoplasm Proteins; Organ Specificity; Ornithine Decarboxylase Inhibitors; Papilloma; Papillomaviridae; Precancerous Conditions; Putrescine; Skin Diseases; Skin Neoplasms; Thorax; Transgenes

Carcinogenesis involves the accumulation of genetic changes within a single cell. Tumor promotion functions in the initial clonal expansion of an initiated cell but is generally not considered to influence later stages. To investigate whether tumor promotion can influence later stages of carcinogenesis we developed a two-hit 7, 12-dimethylbenz[a]anthracene (D) protocol designed to enrich for keratinocytes that contain at least two D-induced genetic alterations. FVB/N mice were initiated with D and promoted with 12-O-tetradecanoylphorbol-13-acetate (T) or treated with acetone (A) vehicle for 6 weeks. At 7 weeks after the start of promotion, but before visible papilloma development, groups of mice were treated with a second dose of D or A and 1 week later T promotion was resumed. D/T/A/T mice developed 2.8 papillomas/mouse and D/A/D/T mice demonstrated an additive tumor response and developed 5.8 papillomas/mouse. Importantly, D/T/D/T mice developed 12.4 papillomas/mouse, thereby demonstrating a synergistic tumor response compared with D/A/D/T and D/T/A/T mice. D/T/D/T papillomas exhibited increases in suprabasal S phase cells and keratin 13 expression when compared with D/T/A/T papillomas. D/T/D/T mice developed squamous cell carcinomas (SCCs) 10 weeks earlier than D/T/A/T mice and demonstrated a 96% malignancy incidence and 1.71 SCC/mouse compared with D/T/A/T mice, which demonstrated a 28% malignancy incidence and 0.32 SCC/mouse. Greater than 90% of D/T/A/T and D/T/D/T papillomas and SCCs contained mutant Ha-ras, while a normal Ha-ras allele persisted in all cases, indicating that a gene other than the remaining normal allele of Ha-ras was a target gene for the second D hit. These data demonstrate that: (i) promotion between the first and second hits has a profound outcome on carcinogenesis, presumably by increasing the probability that a second hit will occur in a previously initiated cell; (ii) continued promotion after the second hit is required for full expression of malignancy; (iii) the classic initiation-promotion protocol can be extended to a multihit, multistage model.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Acetone; Animals; Carcinogens; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Cocarcinogenesis; DNA Mutational Analysis; DNA, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Genes, ras; Keratinocytes; Keratins; Mice; Models, Biological; Neoplasm Proteins; Papilloma; Polymerase Chain Reaction; Polymorphism, Single-Stranded Conformational; S Phase; Skin Neoplasms; Tetradecanoylphorbol Acetate

To determine the role of protein kinase Cdelta in mouse skin carcinogenesis, we have developed transgenic FVB/N mouse lines expressing in the epidermis an epitope-tagged protein kinase Cdelta (T7-PKCdelta) regulated by the human keratin 14 promoter. The untreated T7-PKCdelta mice displayed excessive dryness in the skin of the tail with a variable penetrance over time. Histologically, the tail skin showed hyperplasia with evidence of hyperkeratosis. The epidermis of the rest of the T7-PKCdelta mouse was unremarkable. Despite this mild phenotype, the effects of PKCdelta overexpression on mouse skin tumor promotion by 12-O-tetradecanoylphorbol-13-acetate (TPA) were dramatic. Two independent lines of T7-PKCdelta mice (16 and 37) expressing the T7-PKCdelta transgene were examined for responsiveness to skin tumor promotion by 7,12-dimethylbenz[a]anthracene and TPA. By immunoblot analysis, the T7-PKCdelta-16 and T7-PKCdelta-37 mice showed an 8- and 2-fold increase of PKCdelta protein. The T7-PKCdelta-16 mice averaged 300% more T7-PKCdelta activity than the T7-PKCdelta-37 mice did. The T7-PKCdelta-37 mice did not manifest any difference in tumor burden or incidence. However, the reduction in papilloma burden at 25 weeks of promotion for the T7-PKCdelta-16 mice relative to wild-type mice averaged 72 and 74% for males and females, respectively. The T7-PKCdelta-16 mice reached 50% papilloma incidence between 12 and 13 weeks of promotion compared with 8 weeks for wild-type mice. Furthermore, the carcinoma incidence was also reduced in T7-PKCdelta-16 mice. Carcinoma incidence at 25 weeks of promotion treatment was: wild-type females, 78%; T7-PKCdelta16 females, 37%; wild-type males, 45%; and T7- PKCdelta-16 males, 7%. Thus, PKCdelta when expressed at sufficient levels can suppress skin tumor promotion by TPA.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinogens; Female; Humans; Isoenzymes; Keratin-14; Keratins; Keratosis; Male; Mice; Mice, Transgenic; Neoplasm Proteins; Papilloma; Protein Kinase C; Protein Kinase C-delta; Sex Factors; Signal Transduction; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate

Transgenic mice were developed to explore the role of the erbB2 during epithelial homeostasis and tumorigenesis, through targeted expression of the neu oncogene (neu*). Expression of a neu* cDNA was targeted to the basal layer of skin epidermis as well as other epithelial tissues of transgenic mice via the bovine keratin 5 promoter. Two transgenic founders were obtained that were morphologically distinguishable from non-transgenic littermates by their visibly thickened skin and patchy hair growth by day 3 after birth. The presence of the transgene was confirmed by polymerase chain reaction analysis of tail DNA and immunofluorescence analysis of neu* protein in skin sections. Histological evaluation revealed significant hyperplasia of the follicular and interfollicular epidermis, the abnormal presence of horny material in the dermis and hypodermis, and a dramatic increase in epidermal proliferation. Many areas of the dermis involving this abnormal epithelial proliferation exhibited a squamous cell carcinoma-like appearance. In addition, there was unusual proliferation of the sebaceous glands. One founder died at day 14 and the other at day 20. The latter founder had two papillomas at the time of death. Additional phenotypic changes resulting from the expression of neu* in other tissues included hyperkeratosis in the forestomach and esophagus. In addition, there was a lack of distinction of the cortical-medullary boundaries and an increased rate of cell death in lymphocytes in the thymus. The phenotypic changes in these other tissues correlated with transgene expression. The data suggest that erbB2 signaling has an important role in epidermal proliferation. In addition, the data provide strong support for a role for erbB2 signaling during epidermal carcinogenesis in mouse skin.

Topics: Animals; Female; Gene Expression Regulation, Neoplastic; Genes, erbB-2; Hair Follicle; Homeostasis; Hyperplasia; Keratins; Male; Mice; Mice, Inbred ICR; Mice, Transgenic; Neoplasm Proteins; Papilloma; Promoter Regions, Genetic; Skin Neoplasms; Stomach; Thymus Gland; Transgenes

To develop an in vivo model for studying the role of the p53 tumor suppressor in skin carcinogenesis, a murine p53(172H) mutant (equivalent to human p53(175H)) was expressed in the epidermis of transgenic mice, utilizing a targeting vector based on the human keratin 1 gene (HK1.p53m). HK1.p53m mice developed normally and did not exhibit an obvious epidermal phenotype or develop spontaneous tumors. However, these mice demonstrated an increased susceptibility to a two-stage chemical carcinogenesis protocol, with the rate of formation and number of papillomas being dramatically increased as compared to non-transgenic controls. The majority of papillomas in control mice regressed after termination of 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment, whereas p53m papillomas progressed to carcinomas and metastases. In addition, more advanced malignancy, i.e., undifferentiated spindle cell carcinomas, were exclusively observed in p53m mice. Increased bromodeoxyuridine (BrdU) labeling, accompanied by decreased expression of p21, was observed in HK1.p53m papillomas. In situ examination of centrosomes in HK1.p53m papillomas also revealed marked abnormalities, with 75% of the cells containing > or = 3 centrosomes/cell, whereas centrosome numbers in papillomas from control animals remained normal. These data suggest that the accelerated tumorigenesis observed in chemically-treated p53m mice is most likely due to increased genomic instability resulting from an inhibition of G1 arrest and abnormal amplification of centrosomes.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Bromodeoxyuridine; Carcinogens; Centrosome; Disease Susceptibility; Epidermis; Female; Gene Amplification; Humans; Keratins; Male; Mice; Mice, Transgenic; Mutagenesis, Site-Directed; Papilloma; Promoter Regions, Genetic; Proto-Oncogene Proteins p21(ras); ras Proteins; Skin Neoplasms; Tetradecanoylphorbol Acetate; Transgenes; Tumor Suppressor Protein p53

Upregulation of keratinocyte-derived VEGF-A expression has recently been established in non-neoplastic processes of skin such as wound healing, blistering diseases and psoriasis, as well as in skin neoplasia. To further characterize the effects of VEGF-A in skin in vivo, we have developed transgenic mice expressing the mouse VEGF120 under the control of a 2.4 kb 5' fragment of keratin K6 gene regulatory sequences that confers transgene inducibility upon hyperproliferative stimuli. As expected from the inducible nature of the transgene, two of the three founder mice obtained (V27 and V208), showed no apparent phenotype. However, one founder (V2), mosaic for transgene integration, developed scattered red spots throughout the skin at birth. The transgenic offspring derived from this founder developed a striking phenotype characterized by swelling and erythema, resulting in early postnatal lethality. Histological examination of the skin of these transgenics demonstrated highly increased vascularization and edema leading to disruption of skin architecture. Expression of the transgene was silent in adult animals of lines derived from founders V27 and V208. Phorbol ester-induced hyperplasia resulted in transgene induction and increased cutaneous vascularization in adult transgenic mice of these lines. Skin carcinogenesis experiments performed on hemizygous crosses of V208 mice with activated H-ras-carrying transgenic mice (TG.AC) resulted in accelerated papilloma development and increased tumor burden. Previous results from our laboratory showed that VEGF upregulation is a major angiogenic stimulus in mouse epidermal carcinogenesis. By overexpressing VEGF in the skin of transgenic mice we now move a step further toward showing that VEGF-mediated angiogenesis is a rate-limiting step in the genesis of premalignant lesions, such as mouse skin papilloma. Our transgenic mice constitute an interesting model system for in vivo study of the cutaneous angiogenic process and its relevance in tumorigenesis and other skin diseases.

Topics: Animals; Capillary Permeability; Endothelial Growth Factors; Genes, ras; Hyperplasia; Keratins; Lymphokines; Mice; Mice, Transgenic; Neovascularization, Pathologic; Neovascularization, Physiologic; Papilloma; Precancerous Conditions; Receptor Protein-Tyrosine Kinases; Receptors, Growth Factor; Receptors, Vascular Endothelial Growth Factor; Regulatory Sequences, Nucleic Acid; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

P53 is overexpressed in more than 50% of all human cancers. A previous study suggested that p53 was also overexpressed in oral papillomas. This study was carried out to investigate whether p53 expression was correlated with expression of the cellular proliferation marker Ki-67 and the epithelial differentiation marker cytokeratin-4 (CK4) in oral papillomas. Formalin-fixed paraffin-embedded sections of 30 oral papilloma specimens and 30 unmatched normal oral mucosal specimens were processed for immunohistochemistry, using an avidin-biotin-peroxidase procedure and monoclonal antibodies. A semiquantification analysis on p53 and Ki-67 labeling indices was performed. Twenty-eight of 30 (93%) papilloma specimens were positive for p53. The percentage of p53-positive cells in the basal layer was 60.4 +/- 14.8 (mean +/- SD, n = 28), and that of Ki-67-positive cells was 26.7 +/- 14.4. There was no correlation between expression of p53 and that of Ki-67. Expression of CK4 was inversely correlated with the expression of Ki-67 but not correlated with the expression of p53.

Topics: Antigens, Viral, Tumor; Biomarkers, Tumor; Gene Expression Regulation, Neoplastic; Humans; Immunoenzyme Techniques; Keratins; Ki-67 Antigen; Mouth Neoplasms; Papilloma; Tumor Suppressor Protein p53

We have assessed the role of epidermal growth factor receptor (EGFR) signaling in biological responses to the v-ras(Ha) oncogene using primary keratinocytes from Egfr -/- mice and wild-type littermates. On the basis of several criteria, Egfr -/- keratinocytes were unresponsive to either acute or chronic exposure to several EGFR ligands but were stimulated to proliferate in response to several other mitogens. Although conditioned medium from primary keratinocytes transduced with v-ras(Ha) retrovirus (v-ras(Ha) keratinocytes) was a potent mitogen for wild-type but not Egfr -/- keratinocytes, v-ras(Ha) transduction of primary keratinocytes of either genotype resulted in a strong mitogenic response, arguing against an obligatory role for EGFR activation in v-ras(Ha)-mediated stimulation of keratinocyte proliferation. Infection with high-titer v-ras(Ha) retrovirus altered the keratin expression pattern in keratinocytes of both genotypes, suppressing differentiation-specific keratins K1 and K10 while activating aberrant expression of K8 and K18. In wild-type but not Egfr -/- cultures, K1 and K10 were also suppressed following infection at lower retroviral titers, presumably as a result of paracrine EGFR activation on uninfected cells present in these cultures. Squamous papillomas produced by grafting Egfr -/- v-ras(Ha) keratinocytes onto nude mice were only 21% of the size of wild-type v-ras(Ha) tumors, and a striking redistribution of S-phase cells was detected by immunostaining for bromodeoxyuridine. In Egfr -/- v-ras(Ha) papillomas, the fraction of total labeled nuclei detected in suprabasal layers was increased from 19 to 39%. In contrast, the basal layer labeling index of Egfr -/- papillomas was reduced to 34%, compared to 43% in wild-type tumors. Our results indicate that, although autocrine EGFR signaling is not required for keratinocyte responses to oncogenic ras in culture or benign tumor formation in nude mouse grafts, disruption of this pathway impairs growth of v-ras(Ha) papillomas by a mechanism that may involve alterations in keratinocyte cell cycle progression and/or migration in vivo.

Topics: Animals; Apoptosis; Bromodeoxyuridine; Cell Division; Cells, Cultured; Culture Media, Conditioned; ErbB Receptors; Fluorescent Antibody Technique, Indirect; Genes, ras; Keratinocytes; Keratins; Mice; Mice, Knockout; Neoplasm Transplantation; Papilloma; Time Factors

To directly examine a multistage carcinogenesis model and the role of UV light in human tissues, we grafted human skin onto mice with severe combined immunodeficiency disease. We found that the maximum dose of UV radiation in the B range (UVB; 280-320 nm) tolerated by these grafts was 500 J/m2 three times weekly. One hundred fifty-one grafted mice were then randomized and observed for a median of 9 months in five groups: no treatment, chemical initiation alone, UVB as a complete carcinogen, initiation plus UVB promotion, and initiation plus UVB and phorbol ester promotion. Actinic damage and squamous atypia were found in grafts of all groups receiving UV treatment; unequivocal human squamous carcinomas developed in two of these. Species origin was verified by human-specific bisbenzimide staining and in situ hybridization for human-specific Alu segment. Overall basal proliferation, measured immunohistologically, was reduced in UV-treated grafts, but foci of hyperproliferation were seen in conjunction with the dedifferentiated expression of cytokeratins 1, 10 and 5, 8. Murine tumors also developed frequently, confirming the biological relevance of the carcinogenic strategies tested. These findings demonstrate that development of malignant human tumors can be experimentally accelerated in human tissue.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Antigens, Neoplasm; Carcinogens; Cell Differentiation; Cell Division; Cell Transformation, Neoplastic; Humans; Keratins; Ki-67 Antigen; Mice; Mice, SCID; Neoplasm Proteins; Nuclear Proteins; Papilloma; Skin Neoplasms; Skin Transplantation; Tetradecanoylphorbol Acetate; Transplantation, Heterologous; Ultraviolet Rays

TGFbeta1 has been implicated in cell cycle control and carcinogenesis. To address the exact function of TGFbeta1 in skin carcinogenesis in vivo, mice with TGFbeta1 expression targeted to keratinocytes were subjected to long-term chemical carcinogenesis treatment. TGFbeta1 showed biphasic action during multistage skin carcinogenesis, acting early as a tumor suppressor but later enhancing the malignant phenotype. The transgenics were more resistant to induction of benign skin tumors than controls, but the malignant conversion rate was vastly increased. There was also a higher incidence of spindle cell carcinomas, which expressed high levels of endogenous TGFbeta3, suggesting that TGFbeta1 elicits an epithelial-mesenchymal transition in vivo and that TGFbeta3 might be involved in maintenance of the spindle cell phenotype. The action of TGFbeta1 in enhancing malignant progression may mimic its proposed function in modulating epithelial cell plasticity during embryonic development.

Topics: Animals; Carcinoma; Carcinoma, Squamous Cell; Cells, Cultured; Female; Immunologic Techniques; Integrins; Keratins; Mice; Mice, Transgenic; Papilloma; Skin Neoplasms; Transforming Growth Factor beta

Carcinogenesis proceeds in discrete steps involving initiation and promotion. There is ample evidence that the underlying cause of initiation is mutation, whereas for tumor promotion different hypotheses exist postulating the involvement of both epigenetic and genetic changes. DNA repair protects against tumor formation, but it has not been proven whether protection occurs at the level of tumor initiation or promotion. Since the most advanced experimental system for studying multistep carcinogenesis is the mouse skin, we generated transgenic mice that overexpress the human DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) in their epidermal cells by virtue of cytokeratin (Ck) promoters. Total cellular methyltransferase activity was found to be significantly higher in skin protein extracts of transgenic as compared to nontransgenic mice. CkMGMT transgenic mice along with nontransgenic controls were treated according to the multistage skin carcinogenesis protocol. For initiation, a single subthreshold dose of N-nitroso-N-methylurea (MNU) or 7,12-dimethylbenz(a)anthracene (DMBA) was topically applied to the dorsal skin of the mice. Tumor promotion was carried out by repeated 12-O-tetradecanoylphorbol-13-acetate application. Our results clearly show that CkMGMT transgenic mice are strongly protected against MNU- but not DMBA-initiated skin tumor formation. As compared to nontransgenic controls, transgenic mice exhibited an approximately 6-fold reduction of skin tumor incidence after treatment with 20 micromol or 50 micromol MNU followed by 12-O-tetradecanoylphorbol-13-acetate. These results provide direct and the most compelling evidence to date that the DNA lesion O6-methylguanine is of decisive importance in tumor initiation, and that the protective effect of the repair protein MGMT in carcinogenesis is due to prevention of initiation without affecting tumor promotion.

Topics: Animals; DNA Repair; Gene Expression Regulation, Enzymologic; Humans; Keratins; Methylnitrosourea; Methyltransferases; Mice; Mice, Transgenic; Neoplasms, Experimental; O(6)-Methylguanine-DNA Methyltransferase; Papilloma; Promoter Regions, Genetic; RNA, Messenger; Skin Neoplasms; Transgenes

By using the subtractive hybridization method, two complementary DNA clones differently expressed in rat normal esophageal epithelium and squamous cell carcinoma induced by administration of precursors of N-nitrososarcosine ethyl ester were isolated. A rat homologue of the human 50-kDa type I cytokeratin 14 was cloned for the first time and shown to be expressed preferentially in squamous cell papillomas and carcinomas, whereas it was weakly expressed or absent in normal squamous epithelial cells and in hyperplastic lesions. A rat homologue of the mouse 57-kDa type II cytokeratin showed strong expression in both normal and tumor tissues. These results are well consistent with the reported alteration of keratin subspecies in human esophageal cancers, therefore, encouraging us to use this experimental system as a model for human esophageal carcinogenesis.

Topics: Animals; Carcinogens; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; DNA, Complementary; Esophageal Diseases; Esophageal Neoplasms; Esophagus; Humans; Hyperplasia; In Situ Hybridization; Keratins; Mice; Neoplasm Proteins; Nitrosamines; Papilloma; Precancerous Conditions; Rats; Rats, Wistar; Recombinant Proteins; Subtraction Technique

To assess the synergistic effect of growth and transcription factor deregulation on carcinogenesis in vivo, mating experiments were performed between transgenic mice expressing human TGF alpha or v-fos exclusively in the epidermis by means of a human keratin K1-based targeting vector (HK1.fos, HK1.TGF alpha and HK1.fos/alpha). While HK1.TGF alpha mice exhibited mild epidermal hyperplasia resulting in a wrinkled appearance, this hyperplasia was significantly increased in HK1.fos/alpha mice which also exhibited a novel opalescent and peeling skin phenotype. HK1.fos/alpha keratinocyte differentiation was considerably deregulated with cornified cells appearing in the granular layer, granular cells in the spinous layer and a sixfold increase in BrdU labeling over normal. In addition, hyperplastic HK1.fos/alpha epidermis exhibited aberrant loricrin, filaggrin and novel K13 expression associated with v-fos expression. Unlike adult HK1.TGF alpha controls, hyperplasia persisted in HK1.fos/alpha adults which also rapidly developed autonomous squamous cell papillomas. These results demonstrate that v-fos and TGF alpha over-expression can cooperate to reprogram keratinocyte differentiation and elicit the early stages of neoplasia. Moreover, TGF alpha over-expression appeared to play an early, initiating role in HK1.fos/alpha papilloma etiology, and a promotion role in the accelerated appearance of v-fos wound-associated preneoplastic phenotypes. However, the stable persistence of HK1.fos/alpha papillomas for up to 12 months, suggests that additional events are required for malignant conversion.

Topics: Animals; Base Sequence; Cell Differentiation; Cell Division; Cell Transformation, Neoplastic; Filaggrin Proteins; Genetic Vectors; Keratins; Mice; Mice, Transgenic; Microscopy, Electron; Molecular Sequence Data; Oncogene Proteins v-fos; Papilloma; Skin; Skin Neoplasms; Transforming Growth Factor alpha

Retinoids are powerful regulators of epidermal cell growth and differentiation and are widely used in the prevention and treatment of skin disorders and cancers in humans. Since many of the effects of retinoids on cell growth and differentiation are mediated by nuclear retinoid receptors (RARs and RXRs), we were interested in determining RAR and RXR gene expression during mouse skin tumor progression. The two-stage system of mouse skin carcinogenesis was used to generate papillomas and carcinomas, and the different stages of malignant progression (papillomas, differentiated squamous cell carcinomas, undifferentiated squamous cell carcinomas, and spindle cell carcinomas) were characterized in each tumor by specific keratin expression prior to receptor characterization. Using in situ hybridization analysis, we show that the two major RAR isoforms (alpha 1 and gamma 1), which account for most of RARs in the skin, were expressed in both the basal and suprabasal layers in mouse epidermis. In contrast, RXR alpha transcripts were compartmentalized to the basal cell layers and concentrated in hair follicles. During skin tumor progression, RAR (alpha 1 and gamma 1) transcripts were down-modulated in malignant tumor cells, whereas RXR (alpha and beta) transcript expression was expanded in papillomas and carcinomas as the number of undifferentiated cells also increased. RXR gamma was not detected in the skin or at any stage during skin tumor progression. Spindle cell tumors lacked markers of the keratinocyte phenotype and lost RAR expression, yet retained expression of RXR alpha and beta. The increased abundance of transcripts for RXRs and decreased presence of RARs in skin tumor progression may favor other nuclear signal transduction pathways requiring RXR for heterodimer formation and contribute to phenotypic progression of cancer cells.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinoma; Cell Compartmentation; Epidermis; In Situ Hybridization; Keratins; Mice; Papilloma; Receptors, Retinoic Acid; Retinoid X Receptors; Skin Neoplasms; Tetradecanoylphorbol Acetate; Transcription Factors

Transgenic mice that expressed v-fos exclusively in the epidermis by means of a human keratin K1-based targeting vector (HK1.fos) developed preneoplastic epidermal hyperplasia and hyperkeratosis after long latency and an associated wound promotion stimulus. To assess the requirements for papilloma formation and malignant conversion and determine the sensitivity to a chemical promotion stimulus, HK1.fos mice were promoted with 12-O-tetradecanoylphorbol-13-acetate (TPA). HK1.fos mice were sensitive to TPA promotion but developed papillomas only after long latency (20-30 weeks of promotion) and in relatively few numbers per animal, suggesting the necessity of an additional genetic event prior to overt lesion formation. Consistent with this idea, at 60 weeks, on cessation of TPA promotion, these HK1.fos TPA-papillomas were found to be autonomous, TPA-independent tumors which persisted, grew larger, and converted to malignancy. Analysis of HK1.fos tumor RNA and DNA identified endogenous c-rasHa mutations at codons 12 and 61 in papillomas and carcinomas; however, no p53 tumor suppressor gene mutations were detected. These data indicate that epidermal expression of v-fos induces sensitivity to TPA promotion, but since additional genetic events, such as endogenous c-rasHa activation, appear to be required in tumorigenesis, v-fos may predominantly play a role in the mechanism of promotion to achieve papilloma autonomy and TPA independence. Furthermore, spontaneous malignant conversion in this model does not appear to involve mutations in the p53 tumor suppressor gene.

Topics: Animals; Base Sequence; Biomarkers; Carcinoma; Cell Differentiation; Cell Transformation, Neoplastic; DNA, Neoplasm; Epidermis; Gene Expression Regulation, Neoplastic; Genes, fos; Genes, p53; Genes, ras; Hyperplasia; Keratins; Keratosis; Mice; Mice, Transgenic; Molecular Sequence Data; Mutation; Oncogene Proteins v-fos; Papilloma; ras Proteins; RNA, Neoplasm; Tetradecanoylphorbol Acetate

The proto-oncogene c-fos is a major nuclear target for signal transduction pathways involved in the regulation of cell growth, differentiation, and transformation. Using the multistep skin carcinogenesis model, we have directly tested the ability of c-fos-deficient mice to develop cancer. Upon treatment with a tumor promoter, c-fos knockout mice carrying a v-H-ras transgene were able to develop benign tumors with similar kinetics and relative incidence as wild-type animals. However, c-fos-deficient papillomas quickly became very dry and hyperkeratinized, taking on an elongated, horny appearance. While wild-type papillomas eventually progressed into malignant tumors, c-fos-deficient tumors failed to undergo malignant conversion. Experiments in which v-H-ras-expressing keratinocytes were grafted onto nude mice suggest that c-fos-deficient cells have an intrinsic defect that hinders tumorigenesis. These results demonstrate that a member of the AP-1 family of transcription factors is required for the development of a malignant tumor.

Topics: Animals; Cell Differentiation; Cell Transformation, Neoplastic; Epidermal Cells; Gene Expression; Genes, fos; Genes, ras; Keratinocytes; Keratins; Mice; Mice, Nude; Mice, Transgenic; Mutation; Neoplasm Transplantation; Oncogene Protein p21(ras); Papilloma; Skin Neoplasms; Time Factors; Transcription Factor AP-1

The synthetic retinobenzoic acid RE-80 was evaluated for its potential as an inductor of tumor cell differentiation and as a chemopreventive agent. A minimally toxic dose of RE-80 in vitro produced morphologic changes typical differentiation in epidermal tumor cell colonies. Indirect immunofluorescence indicated induction of a differentiation-associated keratin of internal stratified epithelia, K13, and inhibition of the differentiation-associated epidermal keratin K1. Cultured cells were skin-grafted to athymic nu/nu mice to evaluate RE-80 effects on early stage malignant progression in vivo. When tumors had grown to 3 to 4 mm in diameter, mice were treated by intraperitoneal injection with RE-80 (67 micrograms, 170 mmol, i.p., two times per week) or vehicle (100 microliters 20% ethanol). Papillomas (benign) and moderately differentiated squamous cell carcinomas were reduced in volume about 4-fold by RE-80 treatment. Larger, poorly differentiated squamous cell carcinomas were unaffected. RE-80 resulted in a lower proportion of proliferative cells (detectable by bromodeoxyuridine incorporation) and a higher proportion of moderately to well differentiated tumors after 40 days of treatment compared with control tumors, which were mainly poorly differentiated squamous cell carcinomas. K13 induction in vitro was correlated with response to retinoid in vivo. Induction of differentiation may be mechanism of the response to RE-80 in vivo since carcinoma cells expressing K13 did not incorporate bromodeoxyuridine and were on a terminal pathway.

Topics: Animals; Antineoplastic Agents; Benzoates; Carcinoma, Squamous Cell; Cell Differentiation; Disease Models, Animal; Keratins; Mice; Mice, Nude; Papilloma; Skin Neoplasms; Tetrahydronaphthalenes; Tumor Cells, Cultured

Of 291 immunosuppressed renal transplant recipients (RTRs) with surviving allografts attending the Royal London Hospital, 171 patients (59%) were found to have warty keratoses. On histological analysis, the lesions in 50 patients (17%) showed partial-thickness dysplasia, and 34 (12%) had one or more invasive squamous cell carcinoma (SCC) and/or one or more in situ SCC or full-thickness dysplasia. We examined the claim that squamoproliferative lesions in RTRs possess distinctive histopathological features that differ from those of similar lesions occurring sporadically in the nonimmunosuppressed population. We compared 40 squamoproliferative lesions from RTRs with 40 matched squamoproliferative lesions from nonimmunosuppressed patients; lesions were coded and their source was unknown to the assessors. Two dermatopathologists independently assessed the cases and gave scores for 11 histological features that have been reported to be characteristic of such lesions in the immunosuppressed population. These included a warty architecture, koilocytes, and multinucleate giant cells. Using these criteria, it was not possible to distinguish lesions of immunosuppressed patients from those of immunocompetent people.

Topics: Carcinoma in Situ; Carcinoma, Squamous Cell; Cytoplasmic Granules; Diagnosis, Differential; Epithelium; Female; Giant Cells; Graft Survival; Humans; Hyalin; Immunocompetence; Immunosuppression Therapy; Keratins; Keratosis; Kidney Transplantation; Male; Neoplasm Invasiveness; Papilloma; Skin Neoplasms; Transplantation, Homologous; Warts

Human papillomaviruses (HPVs) are important human pathogens associated with a range of epithelial neoplasia. The rising incidence of HPV infection and association of HPV with malignancy has led to increased interest in appropriate management of these infections. Development of new therapies for viral warts has been frustrated by the lack of availability of models permissive for viral replication. Here we describe the development of HPV-severe combined immunodeficient mouse model which reproduces mature HPV-infected epithelia. Grafting of anogenital and laryngeal papillomas harbouring either HPV-6 or HPV-11 resulted in the formation of a differentiated neo-epithelium exhibiting the hallmark features of HPV infection including basal hyperplasia, acanthosis and koilocytosis. The reformed warty epithelium contained amplified HPV DNA and expressed capsid protein in the differentiated layers. A striking feature is the production of macroscopic papillomata in an anatomically relevant and accessible site, providing a system of particular relevance for the temporal evaluation of developing lesions and selection of antiviral agents.

Topics: Animals; Capsid; Condylomata Acuminata; Disease Models, Animal; DNA Replication; Epithelium; Gene Expression; Humans; Keratins; Laryngeal Neoplasms; Mice; Mice, SCID; Neoplasm Transplantation; Papilloma; Papillomaviridae; Papillomavirus Infections; Proliferating Cell Nuclear Antigen; Protein Precursors; Skin; Skin Transplantation; Transplantation, Heterologous; Tumor Virus Infections; Virus Replication

Keratin 19 is an intermediate filament protein produced by cells of simple epithelia and basal cells of stratified epithelia of different organs. These cell types are associated with important human cancers. We have used the keratin 19 promoter to target the expression of the polyomavirus (Py) large T-antigen, an immortalizing oncogene known to bind to the tumor suppressor retinoblastoma gene product, to epithelial cells. Individuals of the transgenic mouse line K19PyLT-6 developed one or two nodules in one of their lungs. By histology, the nodules were papillary tumors that consisted of nonciliated epithelial cells of the terminal bronchioles. In addition, infiltrates emanating from the nodules were consistent with the development of pulmonary adenocarcinomas. In situ hybridization techniques demonstrated large T-antigen expression in the tumors. Primary cultures were established from a lung tumor dissected from a K19PyLT-6 transgenic mouse. These large T-antigen-expressing cell lines produced the keratin proteins reminiscent of the epithelial origin of the lung tumor. However, further molecular studies indicated that these cell lines did not express Clara cells or pneumocytes markers. s.c. injection of the cell lines into nontransgenic syngeneic mice produced tumors in 2 weeks that resembled malignant pulmonary adenocarcinomas. These animals, which display tumor progression in situ, and the cell lines derived thereof provide a useful system for the study of lung tumorigenesis.

Topics: Adenocarcinoma; Animals; Antigens, Polyomavirus Transforming; Bronchi; Cell Line; Culture Techniques; Humans; Immunohistochemistry; In Situ Hybridization; Keratins; Lung Neoplasms; Mice; Mice, Inbred Strains; Mice, Transgenic; Papilloma; Phenotype; Promoter Regions, Genetic; Restriction Mapping; RNA, Viral; Tumor Cells, Cultured

The patterns of expression of ornithine decarboxylase (ODC) and a number of keratinocyte differentiation products were examined in early papillomas by immunocytochemistry as an initial effort to develop phenotypic markers of the early stages of mouse skin tumorigenesis. Tumors were induced in SENCAR mice by initiation with 7,12-dimethylbenzanthracene, followed by once or twice weekly promotion treatments with 12-O-tetradecanoylphorbol-13-acetate. The patterns of immunocytochemical staining observed in early papillomas, collected after 7 weeks of promotion, were compared to those obtained with control skin and large, hyperkeratotic papillomas, collected after 23 weeks of promotion. In groups receiving 12-O-tetradecanoylphorbol-13-acetate, constitutive and induced ODC expression were evaluated either several days or 4.5 h after the last treatment, respectively. The major differentiation products in suprabasal keratinocytes are keratins, K1 and K10. These keratins were normally expressed in mildly hyperplastic epidermis, but staining became patchy in markedly hyperplastic epidermis. In early papillomas, K1 staining was patchy, and K10 staining occurred in very limited focal areas or was negative, such that the absence of staining delineated the lesions. Antibodies to the basal cell keratins, K5 and K14, stained both basal and suprabasal cells in hyperplastic epidermis and papillomas. Similarly, an antibody to keratin K6, which is expressed under conditions of hyperproliferation, uniformly stained the basal and suprabasal layers of hyperplastic epidermis and papillomas, demonstrating that the staining patterns observed with the antibodies to K1 and K10 were specific. Expression of ODC in the histologically normal skin of control mice was detected only in the hair follicles and depended on the hair cycle. Staining for induced ODC in mice treated with 12-O-tetradecanoylphorbol-13-acetate once weekly for 7 weeks was intense and diffuse throughout the suprabasal layers of the epidermis. In early and large papillomas, staining for constitutively expressed ODC was intense and diffuse in suprabasal cells. This intense staining for ODC occurred consistently in areas with decreased K1 and K10 expression, and, therefore, was associated with an altered pattern of differentiation. High constitutive ODC expression and decreased K1 and K10 expression will be useful phenotypic markers for studying the early stages of tumorigenesis in mouse skin.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Acetone; Animals; Cell Differentiation; Female; Filaggrin Proteins; Immunohistochemistry; Intermediate Filament Proteins; Keratins; Membrane Proteins; Mice; Ornithine Decarboxylase; Papilloma; Skin Neoplasms

Fifty 4- to 6-week-old male random-bred golden hamsters were injected intraperitoneally with a weight-related dose (12.5 mg/kg body weight) of N-methyl-N-nitrosourea (NMU) three times a week for 4 weeks. Groups of seven animals were killed 10, 16 and 22 weeks after the first injection. The palatal gingiva from six animals and the intermolar mucosa from 21 animals was examined. Seven male age-matched untreated control animals were killed at each period. Although all NMU-treated hamsters showed dysplastic and neoplastic changes similar to those in human oral squamous-cell carcinoma, other changes such as acantholytic dyskeratosis, invading cysts, duct-like structures and basaloid islands and cords were not. The extent and severity of the changes increased with time so that by 22 weeks there was extensive involvement of the palatal bone and marrow spaces, the molar periodontal ligament and the greater palatine neurovascular bundle by neoplastic epithelium. The invading epithelium was derived from the junctional, crevicular and palatal gingival and intermolar epithelium. The latent period for the crevicular and junctional epithelia was shorter than that for the palatal gingival and intermolar epithelium. The invasive changes from the latter epithelium were often preceded by exophytic changes such as epithelial projections, papillae and papillomas. Such changes were infrequent for the gingival, crevicular and junctional epithelia. The study shows that intraperitoneal NMU acts as a complete carcinogen on the palatal gingival and intermolar epithelium in hamsters.

Topics: Animals; Connective Tissue; Cricetinae; Epithelium; Gingiva; Gingival Neoplasms; Injections, Intraperitoneal; Keratins; Male; Mesocricetus; Methylnitrosourea; Molar; Mouth Mucosa; Mouth Neoplasms; Palate; Papilloma; Precancerous Conditions

In order to create a transgenic model for human papilloma virus (HPV)-associated carcinogenesis, we have used the regulatory elements of a human keratin K1 (HK1) gene to target the expression of the E6 and E7 oncogenes of HPV-18 exclusively to the epidermis. All murine expressors were viable and lived normal lifetimes; older mice (> 1 year) possessed numerous small lesions with a verrucous (wart-like) histotype. Analysis of newborn epidermis and lesions revealed that the HPV-18 E6/E7 genes were being expressed with a predominance of the E6*/E7 transcript over the full length E6/E7 message. The long latency in lesion appearance may reflect the low level of intact E6 transcripts and the requirement for additional genetic or epigenetic events before production of an overt lesion. In agreement with this proposal, spontaneous papillomas developed that expressed an activated rasHa oncogene (codon 61, A-->T; codon 13, G-->T). All lesions expressed keratin genes K1, K6, and K13 in a fashion characteristic of hyperproliferative or benign tumors with no evidence of malignant conversion. Our results demonstrate that the mouse epidermis represents a relevant in vivo model system to analyze the interaction between HPV and cellular genes in neoplasia.

Topics: Animals; Base Sequence; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; DNA Probes, HPV; DNA-Binding Proteins; Epidermis; Genes, ras; Keratins; Mice; Mice, Transgenic; Molecular Sequence Data; Oncogene Proteins, Viral; Papilloma; Papillomaviridae

Inverted papilloma (transitional cell papilloma, inverted type) is a rare, benign urothelial tumor. The distribution of cytokeratin (CK) expression in 22 cases was investigated and compared with normal urothelium and urothelial carcinomas: CK7/8, basal increased positivity; CK13, diffuse positivity; CK18, loss of intensity and loss of umbrella cell staining; CK19, reduction of positivity; CK20, reduction of umbrella cell staining. The data indicate that the inverted papilloma is a basal cell urothelioma.

Topics: Biomarkers, Tumor; Carcinoma, Transitional Cell; Cystectomy; Electrosurgery; Humans; Immunoenzyme Techniques; Keratins; Neoplasms, Second Primary; Papilloma; Papilloma, Inverted; Urinary Bladder Neoplasms

Laryngeal papillomas are benign epithelial tumors caused by human papillomaviruses. These tumors are characterized by hyperplasia of the spinous layer and abnormal differentiation. Many tumor cell lines over-express the epidermal growth factor (EGF) receptor on their surface, and EGF regulates normal cell growth. We have asked about the relationship of the EGF receptor and EGF response in laryngeal papilloma cells. Papilloma cells showed markedly greater immunohistochemical staining for the EGF receptor, compared to uninfected cells. Both cell types showed a 2-3-fold increase in nuclei incorporating bromodeoxyuridine when EGF was present. Removal of EGF from papilloma cells cultured on collagen rafts permitted normal stratification and differentiation, as determined by synthesis of keratin 13. Inclusion of EGF induced abnormal differentiation with minimal expression of keratin 13. Uninfected laryngeal cells cultured on rafts in the presence of EGF synthesize keratin 13 in all suprabasal cells. EGF reduced both human papillomavirus RNA levels in the papilloma cells and expression of a reporter gene linked to the human papillomavirus 11 enhancers and E6 promoter in uninfected cells. These results suggest that the phenotype of papillomas is induced, in part, by EGF binding to the abundant EGF receptors.

Topics: Cell Differentiation; Cell Division; Epidermal Growth Factor; ErbB Receptors; Humans; Keratins; Laryngeal Neoplasms; Papilloma; RNA, Viral; Tumor Cells, Cultured

Alterations in the pattern of keratin expression are a common feature of skin-tumor development. In this study, we investigated whether the loss of epidermal keratin 1 (K1) and its replacement by mucosal keratin 13 (K13) is unique to mouse skin tumors induced by 7,12-dimethylbenz[a]anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA), since it has been reported that human epidermal tumors do not exhibit aberrant expression of K13. With that purpose, we analyzed the keratin profiles of 16 DMBA-induced hamster skin tumors using monospecific antibodies against K1 and K13. Although all the tumors expressed K1, they also showed an overall tendency towards loss of this keratin; furthermore, none of the tumors expressed K13. Previous studies have suggested that the induction of K13 in mouse skin is related to the mutation of the Ha-ras gene by the initiating agent DMBA, a mutation consistently found in murine DMBA/TPA-induced tumors and rarely found in human skin tumors. Therefore, we also evaluated the tumors for the presence of codon-61 mutations by direct sequencing of DNA extracted from paraffin-embedded tissue sections. Only three tumors showed an A-->T transversion in the second nucleotide of Ha-ras codon 61. However, presence of the mutation did not correlate with K1 staining. Although hamster skin tumors were induced by the same initiator as were mouse skin tumors, hamster skin tumors did not show the same keratin profile. Moreover, their immunohistochemical expression of K1 and K13 and their codon 61 sequences resembled that of their human counterparts. These results suggest that the aberrant expression of K13 may be unique to murine skin. Furthermore, although codon 61 Ha-ras mutation appears to be related to keratin alterations in the mouse model, this mutation is not sufficient to produce the same biochemical changes in other species.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Base Sequence; Carcinoma, Squamous Cell; Cheek; Cricetinae; DNA, Neoplasm; Genes, ras; Immunoenzyme Techniques; Keratins; Male; Mesocricetus; Molecular Sequence Data; Papilloma; Point Mutation; Polymerase Chain Reaction; Sequence Analysis, DNA; Skin Neoplasms; Species Specificity

The regulatory elements of the human keratin K1 gene have been used to target expression of the v-Ha-ras oncogene exclusively in the epidermis of transgenic mice. We developed 12 transgenic mouse lines that express the HK1.ras transgene, producing epidermal hyperplasia in neonates and hyperkeratosis in juveniles. Eventually this skin phenotype diminished but with time adult animals developed papillomas that could persist or regress. The rate and frequency of tumorigenesis appeared to be limited, which suggests that v-Ha-ras requires a second or even third event to elicit and maintain a benign phenotype in transgenic mice. Since in certain transgenic lines papillomas appeared at wound sites, it appears that the promotion stimulus from wounding may be a second event. We envision that such transgenic mice that express v-Ha-ras in the epidermis will become a powerful model for assessing how environmental and molecular factors affect the process of multistage skin carcinogenesis in vivo, as well as a model for evaluating novel therapeutic protocols.

Topics: Aging; Animals; Bacteriophage lambda; Base Sequence; Cell Transformation, Neoplastic; Disease Models, Animal; Female; Fluorescent Antibody Technique; Gene Expression; Gene Expression Regulation, Neoplastic; Genes, ras; Genetic Techniques; Hyperplasia; Keratins; Keratosis; Male; Mice; Mice, Transgenic; Molecular Sequence Data; Papilloma; Polymerase Chain Reaction; Regulatory Sequences, Nucleic Acid; RNA, Neoplasm; Skin Neoplasms

Monoclonal antibody (G6K12) specific for differentiated keratinocytes was developed using in vitro immunization against the SCC-25 cell line. G6K12 only recognized stratified portions of cultured SCC-25 cells. Immunohistochemical examination using normal human oral mucosa showed that specific G6K12-reactivity was limited to the lower spinous-cell layers, while this antibody weakly bound to cells in basal-cell layers as well as in the upper spinous, granular and cornified-cell layers. G6K12 was also reactive to keratinocytes in most moderately- and well-differentiated SCC tissues. Immunoelectron microscopic examination further demonstrated that the G6K12-immunoreactive area was at the outer surface of the entire plasma membrane, including the microvilli of stratified SCC-25. G6K12-binding was reduced 50% by the treatment of native cells with glycoendoceramidase for 2 h. These results suggest that G6K12 recognizes a plasma membrane-anchored glycoconjugate which is specific for differentiated keratinocytes.

Topics: Animals; Antibodies, Monoclonal; Antigens, Differentiation; Antigens, Neoplasm; Biomarkers, Tumor; Carcinoma, Squamous Cell; Enzyme-Linked Immunosorbent Assay; Epithelium; Fluorescent Antibody Technique; Humans; Hybridomas; Immunoglobulin M; Keratinocytes; Keratins; Mice; Microscopy, Immunoelectron; Mouth Mucosa; Papilloma

A case of intraductal papilloma occurring in the anterior lingual salivary gland (Blandin-Nuhn's gland) of a 58-year-old woman is presented. This location has not been reported previously. The results of histologic and immunohistochemical studies point to an epithelial origin of excretory salivary gland ducts and also demonstrate the secretory potential of the tumor cells.

Topics: Antigens, Neoplasm; Female; Humans; Immunohistochemistry; Keratins; Lactoferrin; Membrane Glycoproteins; Middle Aged; Mucin-1; Papilloma; S100 Proteins; Salivary Gland Neoplasms; Salivary Glands, Minor; Tongue Neoplasms

Mouse skin carcinomas arise from a small subpopulation of benign papillomas with an increased risk of malignant conversion. These papillomas arise with limited stimulation by tumor promoters, appear rapidly, and do not regress, suggesting that they differ in growth properties from the majority of benign tumors. The transforming growth factor beta (TGF-beta) proteins are expressed in the epidermis and are growth inhibitors for mouse keratinocytes in vitro; altered TGF-beta expression could influence the growth properties of high-risk papillomas. Normal epidermis, tumor promoter-treated epidermis, and skin papillomas at low risk for malignant conversion express TGF-beta 1 in the basal cell compartment and TGF-beta 2 in the suprabasal strata. In low-risk tumors, 90% of the proliferating cells are confined to the basal compartment. In contrast, the majority of high-risk papillomas are devoid of both TGF-beta 1 and TGF-beta 2 as soon as they arise; these tumors have up to 40% of the proliferating cells in the suprabasal layers. Squamous cell carcinomas are also devoid of TGF-beta, suggesting that they arise from the TGF-beta-deficient high-risk papillomas. In some high-risk papillomas, TGF-beta 1 loss can occur first and correlates with basal cell hyperproliferation, while TGF-beta 2 loss correlates with suprabasal hyperproliferation. Similarly, TGF-beta 1-null transgenic mice, which express wild-type levels of TGF-beta 2 in epidermis but no TGF-beta 1 in the basal layer, have a hyperproliferative basal cell layer without suprabasal proliferation. In tumors, loss of TGF-beta is controlled at the posttranscriptional level and is associated with expression of keratin 13, a documented marker of malignant progression. These results show that TGF-beta expression and function are compartmentalized in epidermis and epidermal tumors and that loss of TGF-beta is an early, biologically relevant risk factor for malignant progression.

Topics: Animals; Base Sequence; Carcinoma, Squamous Cell; Cell Division; Cell Transformation, Neoplastic; Epidermal Cells; Epidermis; Female; Keratins; Mice; Mice, Transgenic; Molecular Sequence Data; Papilloma; Risk; Skin Neoplasms; Transforming Growth Factor beta

Both papillomas and squamous cell carcinomas (SCC) induced in mouse epidermis by initiation with 7,12-dimethylbenz[a]anthracene (DMBA) and promotion with 12-O-tetradecanoylphorbol-13-acetate (TPA) exhibit aberrant expression of a type I keratin, K13, that is normally characteristic of terminal differentiation of internal stratified epithelia. There is evidence that the aberrant expression of K13 depends on the presence of an activated ras gene in mouse epidermal keratinocytes (Sutter et al., Mol Carcinog 4:467-476, 1991). To assess the general validity of this hypothesis, we investigated both aberrant K13 expression and activation of each of the three members of the ras gene family in epidermal tumors induced in four different mouse strains (SKH-1 hr, SENCAR, BALB/c, and C3H/He) by chronic irradiation with ultraviolet (UV) B. The tumor collection comprised nine papillomas and 30 well or poorly differentiated SCC. Aberrant K13 expression occurred in only five of 39 tumors and was restricted to SCC of both types. This indicates that aberrant K13 expression in UV-induced epidermal tumors was intrinsically different from that in chemically induced tumors. Polymerase chain reaction analysis of the tumors for different point mutations in codons 12, 13, and 61 of the Ha-ras and Ki-ras genes and in codon 61 of the N-ras gene revealed that only one of the well differentiated tumors from a SKH-1 hr mouse exhibited a GGA-->GAA mutation in codon 12 of the Ha-ras gene. Although this tumor was also positive for aberrant K13 expression, such a correlation could not be made for the remaining K13-expressing tumors. This indicates that the activation of one of the members of the ras gene family is not a general prerequisite for the aberrant expression of K13 in mouse epidermal keratinocytes.

Topics: Animals; Base Sequence; Carcinoma, Squamous Cell; Gene Expression Regulation, Neoplastic; Genes, ras; Keratins; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Molecular Sequence Data; Neoplasms, Radiation-Induced; Papilloma; Point Mutation; Skin Neoplasms; Transcriptional Activation; Ultraviolet Rays

Transgenic mice have been previously established that express v-rasHa or v-fos exclusively in the epidermis by means of a targeting vector based on the human keratin 1 gene (HK1). Epidermal expression of v-rasHa (HK1.ras) or v-fos (HK1.fos) resulted in hyperplasia, hyperkeratosis, and later, in benign tumors. To assess the potential for oncogene cooperation in vivo mating experiments were performed. Resultant HK1.fos/ras mice exhibited an obvious increase in the severity of neonatal and juvenile preneoplastic phenotypes, together with the immediate onset of tumorigenesis as compared to single oncogene sibling controls. The HK1.fos/ras tumors grew aggressively and often compromised the animals by 10-12 weeks. However, tumors remained benign as determined by histotype and specific keratin markers. These data indicate that v-fos can cooperate with an initiating v-rasHa phenotype to generate autonomous papillomas, but additional events are required for malignant conversion.

Topics: Animals; Animals, Newborn; Base Sequence; Cell Transformation, Neoplastic; DNA Primers; Fluorescent Antibody Technique; Genes, fos; Genes, ras; Genetic Vectors; Humans; Hyperplasia; Introns; Keratins; Mice; Mice, Transgenic; Molecular Sequence Data; Papilloma; Polymerase Chain Reaction; Skin; Skin Neoplasms; TATA Box

Fifty-three breast lesions, which had been fixed in formalin and embedded in paraffin, were immunohistochemically analyzed with monoclonal antibodies to cytokeratin subtypes 1, 5, 10, 14 (34BE12), muscle-specific actins (HHF35) and antiserum to S100 protein, all of which have been used as markers for myoepithelial cells. With these antibodies, a continuous myoepithelial cell layer could generally be seen around the benign ducts and acini. In in situ carcinomas, such a layer could still be observed, though it was usually discontinuous and sometimes absent. In infiltrating carcinomas, no myoepithelial cell layer could be observed. In intraductal hyperplasias, scattered HHF35, 34BE12 and S100-positive cells could be seen amongst the proliferating intraductal cells. In in situ and infiltrating carcinomas, however, such cells could also be observed. This was seen especially with antibodies 34BE12 and S100, and to a lesser extent also with HHF35. Morphologically these cells seemed to belong to the malignant cell population. Although myoepithelial cell preservation is an important morphological parameter in the histological evaluation of breast lesions, the results suggest that the myoepithelial cell markers 34BE12, HHF35 and S100 cannot be used in the differential diagnosis between benign and malignant breast lesions in a straightforward manner. This is because in situ carcinomas have a more or less preserved myoepithelial cell layer, and because many infiltrating and in situ carcinomas contain a subpopulation of neoplastic cells expressing these markers, possibly signifying myoepithelial cell differentiation.

Topics: Actins; Breast Diseases; Breast Neoplasms; Carcinoma; Female; Humans; Immunohistochemistry; Keratins; Papilloma; S100 Proteins

Initiation and promotion in mouse skin carcinogenesis produce multiple benign tumors, squamous papillomas, but only a few squamous cell carcinomas. The spontaneous conversion from the benign to the malignant phenotype occurs over many months and in stages, but induced malignant conversion can be accomplished more rapidly by exposure of papilloma-bearing mice to mutagens or by transfection of papilloma cell lines with specific oncogenes. The analysis of genetic targets responsible for carcinogen-induced neoplastic progression would be facilitated by the development of in vitro models where the process is rapid, focal, and quantitative. To this end, primary newborn mouse keratinocytes were initiated in vitro by the introduction of the v-rasHa oncogene via a defective retrovirus. Recipient cells produce squamous papillomas and have a high proliferation rate in culture medium with 0.05 mM Ca2+, but fail to grow in medium with 0.5 mM Ca2+ which is permissive for growth of malignant keratinocytes. When v-rasHa-keratinocytes were exposed to mutagens in vitro, proliferative foci emerged after culture in 0.5 mM Ca2+ for 4 weeks. These foci stained intensely red with rhodamine stain, could be easily quantitated, and readily incorporated bromodeoxyuridine. Dose-response studies with several mutagens indicated that the number of foci increased with concentration to the point where excessive cytotoxicity developed. Mutagens varied in potency for producing foci in the following order: cis-diamminedichloroplatinum greater than or equal to benzo(a)pyrene diolexpoxide I greater than N-methyl-N'-nitro-N-nitrosoguanidine greater than or equal to 4-nitroquinoline-N-oxide greater than N-acetoxy-acetyl- aminofluorene. The tumor promoter 12-O-tetradecanoylphorbol-13-acetate was inactive in the assay. A subset of cell lines derived from foci produced malignant tumors in vivo, while others were not tumorigenic. Analysis of DNA from cell lines and tumors revealed that most tumorigenic cell lines maintained the v-rasHa genome, whereas the viral sequences were deleted in nontumorigenic cell lines. Immunohistochemical analysis indicated that proliferative foci and quiescent v-rasHa keratinocytes expressed keratin 8, a marker of v-rasHa expression in cultured keratinocytes. Cells in foci, but not v-rasHa control cells, expressed keratin 13, a marker which is strongly associated with the malignant progression of skin tumors in vivo. This in vitro assay provides a quantitative model to

Topics: Animals; Animals, Newborn; Base Sequence; Carcinogens; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Cells, Cultured; Epidermal Cells; Epidermis; Genes, ras; Keratinocytes; Keratins; Methylnitronitrosoguanidine; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Oligodeoxyribonucleotides; Papilloma; Polymerase Chain Reaction; Skin Neoplasms; Tetradecanoylphorbol Acetate; Transfection

The sensitivity of outbred SENCAR mice and inbred SENCAR (SSIN) mice to multistage carcinogenesis was studied. Tumors were induced using either 7,12-dimethylbenz[a]anthracene or N-methyl-N'-nitro-N-nitrosoguanidine as initiators and 12-O-tetradecanoylphorbol-13-acetate or benzoyl peroxide as promoting agents. Although the number of papillomas per mouse was higher in SSIN than in outbred SENCAR mice, the number of carcinomas observed in the SSIN strain was significantly lower regardless of the initiator or promoter used. It was also observed that the expression of markers of premalignant progression (i.e., dysplasia, expression of keratin K13, and loss of keratin K1 expression) was markedly suppressed in SSIN papillomas. After 50 wk of promotion with 12-O-tetradecanoylphorbol-13-acetate, the pattern of expression of K13 and K1 in SSIN mice was comparable to the pattern observed in outbred SENCAR mice after 10 to 20 wk of promotion with 12-O-tetradecanoylphorbol-13-acetate. It was also observed that 67% of the tumors induced in SSIN mice by initiation with 7,12-dimethylbenz[a]anthracene exhibited a mutation in codon 61 of the Ha-ras-1 gene. This latter finding suggests that the differences observed in tumor progression between the inbred strain and the outbred stock are not related to a genetic alteration in the Ha-ras-1 gene but rather to an independent event that we have postulated to involve a putative suppressor gene. The data reported here suggest that the putative gene(s) that confers susceptibility to tumor promotion was segregated from the gene(s) involved in tumor progression during selection and inbreeding of the SENCAR mouse stock.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Benzoyl Peroxide; Carcinoma, Squamous Cell; Female; Genes, ras; Keratins; Methylnitronitrosoguanidine; Mice; Mutation; Papilloma; Skin Neoplasms; Species Specificity; Tetradecanoylphorbol Acetate

In normal epidermis, the expression of keratins 1 and 10 is associated with the loss of proliferative capacity and the onset of terminal differentiation. Keratins 1 (K1) and 10 (K10) are commonly expressed in the differentiating layer of benign tumors, but are lost during progression from the benign to the malignant state in skin carcinogenesis. Active gene constructs of mouse K1 and K10 were introduced into papilloma and carcinoma cell lines derived from keratinocytes to analyze the consequences of the expression of these keratins on the organization of the endogenous cytoskeletal network and on the mitotic activity of the recipient cells. Exogenous K1 integrated into the preexisting keratin K5/K14 network of both SLC-1 carcinoma and 308 papilloma cells. The formation of a recombinant cytoskeleton was more restricted for K10 than for K1 and appeared to be related to a requirement for cessation of cell division before K10 could integrate. The integration of exogenous K1 filaments into the endogenous keratin network was compatible with sustained proliferation of SLC-1 carcinoma cells in vitro. However, the exogenous gene was not expressed in tumor grafts in vivo. In contrast, stable K1 or K10 transfectants could not be selected in 308 cells, suggesting that benign tumor cells expressing suprabasal keratins cannot sustain proliferation.

Topics: Animals; Blotting, Northern; Blotting, Western; Carcinoma, Squamous Cell; Cell Division; Cell Line; Cytoskeleton; Keratins; Mice; Mice, Inbred BALB C; Neoplasm Transplantation; Papilloma; RNA, Neoplasm; Skin Neoplasms; Transfection

Keratins have been demonstrated to be suitable markers of changes taking place during epithelial neoplasia. Therefore, we analyzed 18 mouse skin tumors (nine papillomas and nine squamous cell carcinomas), induced either by two-stage carcinogenesis with 7,12-dimethylbenz[a]anthracene(DMBA)/12-O-tetradecanoylphorbol-13-acetat e or complete carcinogenesis with DMBA, by immunofluorescence with a monoclonal antibody to keratin (K) 8 (TROMA-1). Immunoperoxidase staining and immunoblotting were also used on selected tumor samples to further explore for the presence of K8. All of the papillomas tested were negative for the presence of K8, whereas the carcinomas were positive. The level of K8 expression in carcinomas showed a positive correlation with the degree of malignancy. Northern blot analysis using a K8 cDNA probe suggested that control of K8 expression in mouse skin tumors occurs at the transcriptional level. Double-label immunofluorescence staining using TROMA-1 and RK13 antibodies demonstrated that K8 did not generally colocalize with K13, a keratin normally found in internal stratified epithelial but aberrantly expressed in mouse epidermal tumors. Furthermore, tumors expressing high levels of K8 showed a reduced expression of K13. Histological examination of immunoperoxidase-stained tumors demonstrated that K8-positive cells were mainly found in anaplastic areas, whereas K13 foci were restricted to well-differentiated regions. Our results demonstrate that K8 expression is a marker of late stages of carcinoma progression in the mouse skin carcinogenesis model.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Blotting, Northern; Carcinoma, Squamous Cell; Electrophoresis, Polyacrylamide Gel; Epithelium; Female; Fluorescent Antibody Technique; Gene Expression; Genes, ras; Immunoenzyme Techniques; Keratins; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mutation; Papilloma; RNA; Skin Neoplasms; Tetradecanoylphorbol Acetate

The distribution of simple epithelial (K8/18/19) and basal (myoepithelial) (K5/14) keratins, alpha-smooth-muscle actin, vimentin, collagen IV and laminin in normal mammary glands and in benign proliferative lesions was studied using monoclonal antibodies (mAbs). These antibodies (Abs) identified myoepithelial cells and luminal cells specifically. In lesions with adenosis and papillomas, the two-layered formation resembled that of normal glands with a purely myoepithelial-epithelial differentiation. In scleradenotic lesions, the main cell was of myoepithelial immunophenotype with intermixed trabecular-tubular proliferations of simple-type epithelium. The sclerosis seems to be the result of an irregular basal lamina synthesis by the myoepithelial cells. In contrast to these lesions, epitheliosis represents a purely intraluminal cell proliferation of clearly simple epithelial immunophenotype and of cells with a basal keratin phenotype, lacking myoepithelial differentiation antigen actin. The basal keratin type epithelium may represent post-stem or intermediate cells developing into luminal epithelium. Epitheliosis appears to be a purely epithelial hyperplasia with striking similarity to the regeneration of normal breast epithelium. The different proliferative patterns may give an explanation for differences in potential cancer risks of patients with these lesions.

Topics: Actins; Adenoma; Antibodies, Monoclonal; Biomarkers, Tumor; Breast; Breast Neoplasms; Cell Division; Collagen; Epithelium; Female; Humans; Keratins; Laminin; Muscles; Papilloma; Vimentin

Transforming growth factor-alpha (TGF-alpha) is thought to be the major autocrine factor controlling growth in epidermal cells. To explore further the role of TGF-alpha in epidermal growth and differentiation, we used a human keratin K14 promoter to target expression of rat TGF-alpha cDNA to the stratified squamous epithelia of transgenic mice. Unexpectedly, the only regions of epidermis especially responsive to TGF-alpha overexpression were those that were normally thick and where hair follicle density was typically low. This included most, if not all, body skin from 2-day- to 2-week-old mice, and ear, footpad, tail, and scrotum skin in adult mice. In these regions, excess TGF-alpha resulted in thicker epidermis and more stunted hair growth. Epidermal thickening was attributed both to cell hypertrophy and to a proportional increase in the number of basal, spinous, granular, and stratum corneum cells. During both postnatal development and epidermal differentiation, responsiveness to elevated TGF-alpha seemed to correlate with existing epidermal growth factor (EGF) receptor levels, and we saw no evidence for TGF-alpha-mediated control of EGF receptor (EGFR) expression. In adults, no squamous cell carcinomas were detected, but benign papillomas were common, developing primarily in regions of mechanical irritation or wounding. In addition, adult transgenic skin that was still both sensitive to TGF-alpha and subject to mild irritation displayed localized regions of leukocytic infiltration and granular layer loss, characteristics frequently seen in psoriasis in humans. These unusual regional and developmental effects of TGF-alpha suggest a natural role for the growth factor in (1) controlling epidermal thickness during development and differentiation, (2) involvement in papilloma formation, presumably in conjunction with TGF-beta, and (3) involvement in psoriasis, in conjunction with some as yet unidentified secondary stimulus stemming from mild mechanical irritation/bacterial infection.

Topics: Animals; Animals, Newborn; Blotting, Northern; Cell Differentiation; Cell Division; Cells, Cultured; Epidermis; ErbB Receptors; Humans; Keratins; Mice; Mice, Transgenic; Papilloma; Phenotype; Psoriasis; Transforming Growth Factor alpha; Wounds and Injuries

Differential screening of cDNA libraries made from chemically induced malignant mouse skin squamous cell carcinomas (SCC) identified three sequences, including one called mal2, that were upregulated in their expression at both the benign papilloma and malignant SCC stages. The mal2 plasmid cDNA clone (containing a 350 bp insert) was used to screen lambda phage cDNA libraries made from chemically induced SCCs. Two of the largest mal2-related cDNA inserts obtained from the phage libraries were sequenced. In addition a mal2-related genomic clone was obtained by hybridization probing of a mouse spleen genomic DNA library. The sequence of the genomic clone overlapped and was identical with both the mal2 plasmid and lambda cDNA clones. Identity was found between the mal2 cDNAs, the mal2 genomic sequence and the cDNA sequence for a mouse hyperproliferative keratin called K6. A synthetic oligonucleotide specific for the 3' untranslated region of the mal2 or keratin K6 gene was used in Northern analyses to demonstrate elevated steady-state levels of K6 keratin transcripts in SCCs induced by various protocols involving both chemical and ionizing radiation initiation of tumors as well as complete chemical and radiation carcinogenesis protocols. Metastatic lung lesions derived from SCCs generated by repeated doses of benzo[a]pyrene showed moderate levels of K6 keratin transcripts, whereas normal lung showed very low levels of K6 transcripts. The overexpression of the mal2 or keratin K6 gene in malignant SCCs was independent of the protocol, either chemical or radiation, that was used to induce the tumors.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Base Sequence; Carcinoma, Squamous Cell; Gene Expression Regulation, Neoplastic; Keratins; Mice; Molecular Sequence Data; Papilloma; Skin Neoplasms; Tetradecanoylphorbol Acetate

Alterations in the pattern of epidermal cell differentiation and proliferation in mouse skin and benign skin tumors were studied by two-color immunofluorescence using monospecific antibodies. Replicating cells were identified by 5-bromo-deoxyuridine (BrdU) pulse-labeling and differentiating cells by keratins K1 and K10. In normal mouse skin, pulse-chase experiments for 120 h revealed that replication was restricted to a single layer of basal cells. Replicating cells did not express K1 or K10, but these keratins were sequentially expressed in post-mitotic basal cells 18 and 24 h following DNA synthesis respectively, and cells expressing these keratins migrated into the suprabasal layers. In phorbol-ester- or cantharidin-stimulated hyperplastic skin, replicating cells were also confined to the basal cell compartment and suprabasal cells expressed keratins 1 and 10. In papillomas induced by initiation with 7,12-dimethylbenz[a]anthracene and promotion with 12-O-tetradecanoylphorbol-13-acetate, replication occurred predominantly in cells in an expanded basal cell compartment (two to four layers above the basement membrane). Cells in these basal layers did not express K1 or K10, but more superficial cells did. After a 1 h pulse of BrdU, replication was also identified in suprabasal cells expressing the differentiation-associated keratins. These and other results suggest that benign tumor cells escape the obligatory growth arrest associated with differentiation. Replication of K1- and K10-expressing suprabasal cells may represent an early alteration during mouse skin carcinogenesis.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Cell Differentiation; Cell Division; Female; Gene Expression Regulation, Neoplastic; Keratinocytes; Keratins; Male; Mice; Mice, Hairless; Microscopy, Fluorescence; Papilloma; Skin Neoplasms; Tetradecanoylphorbol Acetate

Introduction of the v-Ha-ras gene into primary epidermal keratinocytes, followed by grafting of these cells to animals, leads to the formation of benign epidermal tumors that resemble papillomas induced chemically by a two-stage carcinogenesis protocol. In this study, we investigated v-Ha-ras-induced papillomas for aberrant expression of type I keratin K13, previously described in 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoylphorbol-13- acetate (DMBA/TPA)-induced mouse epidermal tumors. Papillomas produced from three independent infection series were removed 3 wk after grafting concomitant with control grafts originating from mock-, neo-, and v-fos-infected primary keratinocytes. Combined analysis of the grafts by western blotting of extracted keratins and immunofluorescence studies of frozen sections with a K13-monospecific antibody revealed K13 expression in all v-Ha-ras-induced papillomas and absence of this keratin in all control grafts. K13-positive cells in papillomas were restricted to the suprabasal cell layers of the lesions and, at this stage of papilloma development, occurred as foci of varying extensions. Analysis of genomic DNA from v-Ha-ras-induced papillomas for the methylation state of a CpG dinucleotide in the distant promoter region of the K13 gene revealed the occurrence of unmethylated DNA copies that were generated at the expense of methylated DNA copies ubiquitously present in normal epidermis. The ratio of unmethylated to methylated DNA copies correlated with the extent of suprabasal K13 protein expression. Thus, all features of aberrant K13 expression previously described in DMBA/TPA-induced papillomas were shared by v-Ha-ras-induced papillomas.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Base Sequence; Blotting, Western; Fluorescent Antibody Technique; Gene Expression; Genes, ras; Keratinocytes; Keratins; Methylation; Mice; Molecular Sequence Data; Oligonucleotides; Oncogene Protein p21(ras); Oncogene Proteins v-fos; Papilloma; RNA, Messenger; Skin Neoplasms; Skin Transplantation; Tetradecanoylphorbol Acetate

An immunohistochemical study of glial fibrillary acidic protein (GFAP), S-100 protein, cytokeratin (CKER), epithelial membrane antigen (EMA), and transthyretin (TTR) was carried out on 11 cases of choroid plexus papilloma (CPP) and 19 of ependymoma, using the peroxidase antiperoxidase technique. Among the 11 cases of CPP, all 11 were positive for CKER, EMA, and TTR, 10 for S-100 protein, and five for GFAP. Most of the GFAP-positive papilloma cells were simultaneously positive for CKER. However, these GFAP-positive cells were negative for TTR. Among the 19 cases of ependymoma, 16 were positive for GFAP, 17 for S-100 protein, three for CKER, eight for EMA, but none for TTR. Some GFAP-positive cells were also stained for CKER. However, TTR was not found in any of the ependymal cells. These findings suggested that CPP cells which show ependymal or glial differentiation lost the ability to synthesize TTR which is known to be synthesized in the epithelial cells of the choroid plexus. The more GFAP-positive cells present in a CPP, fewer TTR-positive cells are present. Though CPPs are usually easily distinguishable from ependymomas, occasional doubt arises concerning the differential diagnosis between CPP and papillary ependymoma. TTR can be a very useful diagnostic marker of CPP.

Topics: Adult; Biomarkers, Tumor; Child; Child, Preschool; Choroid Plexus Neoplasms; Diagnosis, Differential; Ependymoma; Female; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Infant; Keratins; Male; Membrane Glycoproteins; Middle Aged; Mucin-1; Papilloma; Prealbumin; S100 Proteins

Keratin expressions in normal equine epidermis and experimentally induced equine papillomas were studied by immunohistochemical methods with three different human cytokeratin monoclonal antibodies, 34 beta B4 (directed against component 1), 34 beta E12 (directed against components 1, 5, 10, 11) and 35 beta H11 (directed against component 8). Staining patterns with 34 beta B4 and 34 beta E12 in the normal equine epidermis did not differ from those in the normal human epidermis. In the early developing papilloma, keratinocytes showed an abnormal suprabasal staining pattern and expressed an additional 56 kD keratin protein detected by 34 beta E12. In the advanced papilloma, cytolytic cells in the outer spinous and the granular layers did not stain positively with any of the three antibodies used. In both early and advanced papillomas, the expression of high molecular weight keratin proteins, as detected by 34 beta B4 and 34 beta E12, did not correlate with the degree of keratinization. By electron microscopy, keratinocytes in the advanced papilloma showed a marked decrease of tonofibrils and desmosome-tonofilament complex. These alterations may result from an abnormality in both proliferation and functional terminal differentiation of keratinocytes in the papilloma. There were obvious differences in staining patterns with 35 beta H11 between the normal human and equine epidermis; 54 kD keratin protein was expressed in suprabasal layers of the equine normal and papillomatous epidermis. Thus, this keratin protein may be regarded as a "permanent" marker for the equine epidermis.

Topics: Animals; Antibodies, Monoclonal; Epidermis; Head and Neck Neoplasms; Horse Diseases; Horses; Keratins; Microscopy, Electron; Molecular Weight; Neoplasm Proteins; Papilloma; Skin Neoplasms

The promoter region of the suprabasal keratin 10 gene has been used to direct expression of a mutant human Harvey-ras oncogene to the differentiating cells of the mouse epidermis. Transgenic animals develop hyperkeratosis of the skin and forestomach--the two sites known to express high levels of the keratin 10 polypeptide in vivo. Papillomas subsequently develop on the skin surface, initially at sites subject to biting or scratching such as the base of the tail or behind the ears. The results suggest that the "second event" involved in tumor development in these transgenic animals is the local induction of a mild wounding stimulus. Furthermore, because the H-ras transgene is expressed in suprabasal cells, it appears that cells which have left the stem cell compartment can be induced to form at least benign tumors in vivo.

Topics: Animals; Chromosome Mapping; Cloning, Molecular; Epidermis; Gene Expression; Genes, ras; Keratins; Mice; Mice, Transgenic; Papilloma; Promoter Regions, Genetic; Skin; Skin Diseases; Skin Neoplasms; Stomach; Wound Healing

We studied the proliferation and differentiation of human laryngeal papillomas, which are benign tumors induced by human papillomaviruses. Immunofluorescent stains of tissues for a number of differentiation-specific proteins showed abnormal differentiation. Papilloma tissue fragments in vitro showed a slightly decreased fraction of proliferating cells that incorporated tritiated thymidine and a markedly reduced incorporation of tritiated uridine when compared with normal tissue. We propose that papillomavirus infection results in normal basal cell proliferation but abnormal terminal differentiation and that this abnormality significantly contributes to the hyperplasia of the papillomas.

Topics: Cell Division; Cell Transformation, Neoplastic; Filaggrin Proteins; Humans; Immunoblotting; Intermediate Filament Proteins; Keratins; Laryngeal Neoplasms; Neoplasm Proteins; Papilloma; Papillomaviridae; Protein Precursors; Staining and Labeling; Thymidine; Tumor Virus Infections; Uridine

The premalignant evolution of chemically induced mouse skin papillomas is characterized by dysplastic changes, aneuploidy, induction of gamma-glutamyl transpeptidase (GGT), and changes in the expression of keratins, especially differentiation-associated K1. This keratin, which is expressed in normal epidermis and early papillomas, is no longer present in more advanced dysplastic and aneuploid papillomas and in fully invasive carcinomas. More recently, it has been shown that K13, a keratin normally present in internal epithelia but not in epidermis, is aberrantly expressed in epidermal tumors. In the present study, the timing of expression of K13 and its correlation with other markers of premalignant evolution were investigated. Papillomas were induced by SENCAR mice by a single initiating dose of 20 nmol of 7,12-dimethylbenz[a]-anthracene (DMBA) and promotion with 12-O-tetradecanoylphorbol-13-acetate (TPA) (2 micrograms twice a week). Tumors were randomly harvested at 10, 20 and 35 weeks of promotion. K13 and K1 expression in papillomas was studied using immunoblotting and immunostaining of consecutive sections, as previously described. As expected from previous studies, the distribution of K1 in papillomas collected at 10 weeks of promotion was restricted to differentiated cells and was uniform throughout the section of the papilloma. Conversely, K13 was expressed only as small foci in 10 out of 21 papillomas (48%). Papillomas of 20 weeks were also positive for K1. Staining for K13 was positive in these papillomas with the exception of only one that was essentially negative, presenting only one small positive focus. Some of the papillomas collected at week 35 were negative for K1, but immunostaining with K13 showed uniform staining of suprabasal cells in all the papillomas studied. In all cases, immunohistochemical results were confirmed by immunoblotting with proteins extracted from 7 microns sections from each paraffin block. These results indicate that keratins K1 and K13 are coexpressed in most papillomas from 10 to 35 weeks of promotion. However, analysis of adjacent sections showed that K13 positive areas are topographically located in the K1 negative areas of the papillomas, suggesting a shift in the differentiation program from epidermal to mucosal types of keratinization. Based on these and previous studies from our laboratory, we conclude that K13 is an early marker of papillomas progression, which occurs before gross chromosomal abnormalities

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Keratins; Mice; Papilloma; Precancerous Conditions; Skin Neoplasms; Time Factors

Topics: Cerebral Ventricle Neoplasms; Choroid Plexus; Humans; Keratins; Papilloma

The neoplastic cells present in a sialadenoma pappiliferum were found by immunoperoxidase method and immunofluorescent staining technique to co-express 3 different types of intermediate-sized filaments (IFs) defined by monoclonal antibodies to cytokeratin, vimentin and desmin. When other salivary gland tumors such as 18 pleomorphic adenomas, 15 adenolymphomas, 2 oxyphilic adenomas, 7 mucoepidermoid tumors, 5 acinic cell tumors, 8 adenoid cystic carcinomas and 6 adenocarcinomas were examined immunohistochemically for the expression of IFs, no tumors with all 3 types of IFs observed in sialadenoma papilliferum were found.

Topics: Adenocarcinoma; Adenolymphoma; Adenoma, Pleomorphic; Carcinoma; Carcinoma, Adenoid Cystic; Desmin; Fluorescent Antibody Technique; Humans; Immunoenzyme Techniques; Intermediate Filaments; Keratins; Papilloma; Salivary Gland Neoplasms; Vimentin

Recently, regional changes of cytokeratin patterns in human normal non-keratinized or keratinized oral mucosa have been demonstrated and the expression of individual cytokeratin polypeptides in lesions of oral mucosa has been compared with that of normal tissues. In particular, the presence of cytokeratin 19 in the suprabasal cell layers of oral epithelia has been shown to be strongly correlated with premalignancy. In the present study, we describe the results of an immunohistochemical investigation performed using a monoclonal antibody specific for cytokeratin 1 on normal oral mucosa and benign or malignant oral lesions. We show the different distribution of this polypeptide in non-neoplastic lesions from different sites of oral mucosa and describe the presence of cytokeratin 19. Our results are in agreement with the data obtained previously. In the malignant cases we demonstrate that the distribution of the two cytokeratins is characterized by complementary patterns.

Topics: Carcinoma, Squamous Cell; Histocytochemistry; Humans; Immunoblotting; Immunoenzyme Techniques; Keratins; Leukoplakia, Oral; Mouth Mucosa; Mouth Neoplasms; Papilloma; Precancerous Conditions; Tissue Distribution

Topics: Adult; Calculi; Dermatitis, Seborrheic; Humans; Keratins; Male; Papilloma; Sebum; Umbilicus

Eleven benign and five malignant choroid plexus papillomas in children and adults were studied immunohistologically with a panel of antibodies against glial fibrillary acidic protein, S-100 protein, vimentin, desmin, epithelial membrane antigen and two different cytokeratins (LP34 and CAM 5.2). Glial fibrillary acidic protein was focally present in epithelial tumour cells, in cells within solid areas and in clusters of cells within the stroma. S-100 protein was diffusely present in tumour cells with focal accentuation. Vimentin was present in all cases, the epithelial tumour cells demonstrating strong and diffuse positivity with perinuclear accentuation; malignant tumours, however, showed stronger positivity than benign ones. Desmin was negative in all tumours. Epithelial membrane antigen and cytokeratin (LP34) were demonstrated in four of five malignant tumours but were absent in the benign ones; CAM 5.2 reacted with four of five malignant tumours and also reacted with eight of the 11 benign ones. The significance of these findings is discussed in respect of the ontogeny of these tumours.

Topics: Adolescent; Adult; Antigens, Neoplasm; Carcinoma; Cerebral Ventricle Neoplasms; Child; Child, Preschool; Choroid Plexus; Diagnosis, Differential; Female; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Infant; Infant, Newborn; Keratins; Male; Membrane Glycoproteins; Middle Aged; Mucin-1; Papilloma; S100 Proteins; Vimentin

Ten cases of choroid plexus tumors (3 papillomas and 7 carcinomas) were tested for the presence of glial fibrillary acidic protein (GFAP) and cytokeratin. None of the papillomas and one of the carcinomas were positive with GFAP antisera. Cytokeratin-positive cells were present in 2 of 7 carcinomas and in all papillomas. There seems to be a positive correlation between the degree of the tumor differentiation and the expression of intermediate filaments.

Topics: Carcinoma; Cerebral Ventricle Neoplasms; Choroid Plexus; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Keratins; Papilloma

The presence or absence of myoepithelial cells (ME) has been considered as an important feature in the differential diagnosis of benign and malignant papillary lesions of the breast. We evaluated the distribution of myoepithelial cells in formalin-fixed paraffin-embedded tissue sections of 25 papillomas and 18 papillary carcinomas by ABC immunoperoxidase technique with antibodies to muscle actin (HHF-35) and high molecular weight (HMW) keratin (clone 34BE12, cytokeratins 1, 5, 10, and 14; reacting preferentially with ME cells) and an antiserum to S-100 protein. Also included in the study were eight cases of micropapillary ductal carcinoma in situ (DCIS) having a few fibrovascular cores and five peripheral papillomas with accompanying ductal carcinoma in situ or atypical hyperplasia. The antibodies to muscle actin were sensitive and relatively specific for ME cells of the breast and uniformly labeled ME cells in all 25 papillomas. ME cells were absent or extremely sparse in papillary carcinomas. They were present focally in some of the fibrovascular cores of the micropapillary DCIS, and a mixed pattern was observed in peripheral papillomas with areas of carcinoma. HMW keratin was variably expressed in ME cells in most cases with positive internal controls and was present in several normal ductal and papilloma epithelial cells but not in epithelial cells of papillary carcinomas. HMW keratin, although less specific for ME cells, was a useful adjunct because of its reactivity with ME cells as well as hyperplastic epithelial cells in papillomas, which resulted in a combined positive reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Actins; Antibodies, Monoclonal; Breast; Breast Neoplasms; Carcinoma, Papillary; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Keratins; Myoepithelioma; Papilloma; S100 Proteins

Normal bladder urothelium and large spectrum bladder lesions have been investigated by immunohistochemistry with monoclonal antibodies of variable specificity (SK 56-23, a large spectrum antibody; SK 60-61, which reacts with cytokeratin polypeptides no. 8 and 18 of Moll's catalogue; SK 2-27, specific for polypeptides no. 14, 16 and 17). The normal urothelial pattern is in agreement with previous reports. In pathological conditions, modified immunostaining has been demonstrated in almost all cases. In detail, the cytoskeletal pattern detected in transitional cell papilloma seems to discriminate between types which are otherwise histologically similar. We also observed a correlation between higher degrees of malignancy and loss of specialization, as demonstrated by the increasing positivity for SK 60-61, which as a rule specifically stains "umbrella" cells, and SK 2-27, an antibody exclusively detected in cells of the basal layer. These findings indicate that the cytokeratin pattern may constitute a modern new tool for the pathologist in the diagnosis of urothelial proliferative disorders.

Topics: Antibodies, Monoclonal; Carcinoma, Transitional Cell; Cystitis; Epithelium; Histocytochemistry; Humans; Immunohistochemistry; Keratins; Metaplasia; Papilloma; Urinary Bladder; Urinary Bladder Diseases; Urinary Bladder Neoplasms

Twenty-six ependymal and 15 choroid plexus tumors were examined with monoclonal antibody against cytokeratin using the avidin-biotin-peroxidase complex (ABC) technique. Serial sections were examined with antisera to glial fibrillary acidic protein (GFAP). In five ependymal tumors (one ependymoma, two papillary ependymomas, and two primitive neuroectodermal tumors [PNET] with ependymal cells), a variable number of cytokeratin-positive cells were present. Most tumor cells (except two PNET) were positive with GFAP antisera. Many cytokeratin-positive cells were present in all choroid plexus tumors. GFAP-positive cells were present focally in six of 11 papillomas and in one of four carcinomas. Although their staining patterns and distribution were clearly different, focal coexistence of cytokeratin and GFAP was observed in six papillomas and two ependymal tumors. Thus, some ependymal tumors (especially papillary ependymomas and occasional PNET) and many choroid plexus tumors have demonstrable positivity with antibody to cytokeratin, suggesting a transitional cell type with features of both ependyma and choroid plexus.

Topics: Carcinoma; Cerebral Ventricle Neoplasms; Child; Choroid Plexus; Ependyma; Ependymoma; Glial Fibrillary Acidic Protein; Humans; Immunoenzyme Techniques; Immunohistochemistry; Keratins; Papilloma

The immunohistochemical reactivity on frozen sections of diverse benign and malignant epithelial proliferations of human breast tissue from 156 patients was examined using antibodies to different cytokeratins. Antibodies recognizing cytokeratins 18 and 19 reacted with luminal epithelial cells but not with myoepithelial cells of normal mammary gland, cystic disease, adenosis, papilloma, and fibroadenoma or with a subpopulation of proliferating cells in sclerosing adenosis and epitheliosis. These antibodies reacted with the tumor cells of all in situ and invasive carcinomas. KA1 antibody, which by one- and two-dimensional gel electrophoresis and immunoblotting was shown to bind preferentially to cytokeratin 14 in a complex with cytokeratin 5, reacted with the nonproliferating myoepithelium of normal gland, cystic disease, adenosis, papilloma, fibroadenoma, and in situ carcinoma; it also reacted with a subpopulation of proliferating cells in sclerosing adenosis and epitheliosis (papillomatosis) but was negative with the tumor cells of all preinvasive and most invasive carcinomas. In adenotic and epitheliotic proliferations, groups of cells were identified that reacted strongly with KA1 antibody in addition to antibodies to cytokeratins 18 and 19. The data are discussed with respect to epithelial cell heterogeneity in the breast. We show that by using such antibodies, benign epithelial proliferations are clearly distinguished from carcinomas.

Topics: Adenofibroma; Adult; Aged; Antibodies, Monoclonal; Breast; Breast Neoplasms; Carcinoma, Intraductal, Noninfiltrating; Carcinoma, Papillary; Diagnosis, Differential; Female; Fibrocystic Breast Disease; Humans; Immunohistochemistry; Keratins; Middle Aged; Papilloma

Cellular localization of cytokeratin and glial fibrillary acidic protein (GFAP) was examined in two normal choroid plexuses and five choroid plexus papillomas by the peroxidase-antiperoxidase (PAP) method and double immunofluorescence (IFL) microscopy. Cytokeratin was observed in the majority of epithelial cells in all samples of normal and neoplastic choroid plexuses. On the other hand, GFAP was observed in some of the constituent epithelial cells in two cases of papilloma. Most of these GFAP-positive papilloma cells were simultaneously positive for cytokeratin, as could be seen by the PAP stainings of serial sections and by the double IFL stainings of the same sections. From these findings, it was suggested that normal and neoplastic choroid plexus epithelial cells usually express cytokeratin and that some of the neoplastic cells can simultaneously express both cytokeratin and GFAP.

Topics: Adult; Cerebral Ventricle Neoplasms; Child, Preschool; Choroid Plexus; Female; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Infant; Keratins; Male; Papilloma

This study examines the expression of anchorage independence and tumorigenicity in early cultures of oral rat keratinocytes. The epithelial cell lines originated from the palatal and the lingual mucosa of rats that had been painted with the carcinogen 4-nitroquinoline N-oxide. The colony forming efficiency (CFE) in gel culture of the cell lines derived from five squamous cell carcinomas of the tongue and palate predominantly increased with passage in culture. Carcinoma-derived cell lines that had a relatively high CFE (greater than 2.5%) formed tumours when transplanted to athymic mice, but cells in which the CFE was less than 2.5% were non-tumorigenic. Keratinocytes from a dysplastic palatal lesion were immortal, anchorage dependent and non-tumorigenic. A lingual papilloma cell line consistently expressed a very low CFE but was tumorigenic at the higher culture passages. The results show that the routine passage of cells in culture leads to the emergence of the anchorage independent and tumorigenic phenotypes in keratinocytes of malignant origin and, further, suggest that anchorage independence and tumorigenicity may exist as distinct phenotypes, with anchorage independence preceding tumorigenicity.

Topics: Animals; Carcinoma, Squamous Cell; Cell Adhesion; Epidermal Cells; Keratins; Mice; Mice, Nude; Neoplasms, Experimental; Palatal Neoplasms; Papilloma; Phenotype; Rats; Rats, Inbred Strains; Tongue Neoplasms; Tumor Cells, Cultured

Monospecific antikeratin antisera and specific complementary DNA probes were used to analyze expression of keratin genes in newborn mouse skin and skin papillomas and carcinomas by indirect immunofluorescence, immunoblotting, and in situ hybridization. Tumors were induced by initiation with 7,12-dimethylbenz[a]anthracene and promotion with 12-O-tetradecanoylphorbol-13-acetate. Type I epidermal keratin K14 protein (Mr 55,000) is found in all living layers of the newborn skin but is most abundant in the lower strata. K1 (Mr 67,000) and K10 (Mr 59,000) proteins are predominantly suprabasal and K1 is processed in the stratum corneum. Transcripts for K14 were confined largely to the basal cell layer by in situ hybridization. Transcripts for K1 and K10 were highly expressed in suprabasal cells including the granular cell layer. In benign tumors, distribution of K14 protein is similar to that in newborn skin, while the abundance of K1 and K10 appears to be somewhat reduced although the tissue distribution remains suprabasal. Transcription of K14 is aberrant in benign tumors and transcripts persist throughout much of the suprabasal cell layers. Transcripts of K1 and K10 are normally distributed in papillomas but grain density is less intense than in newborn epidermis. Keratin expression in carcinomas is highly disturbed. K14 protein and transcripts are highly expressed in all strata in carcinomas while protein and transcripts for K1 and K10 are essentially absent. These results suggest that papilloma cells fail to respond to or generate signals to regulate K14 expression in the differentiating suprabasal cell layers and may not fully express their suprabasal cell keratins. Carcinomas fail to express suprabasal cell keratins and this is regulated at the transcriptional level. The loss of suprabasal keratin expression may provide a marker for malignant conversion in the mouse skin carcinogenesis model.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Animals, Newborn; Carcinoma; Cell Transformation, Neoplastic; Female; Gene Expression Regulation; Genes; Keratins; Mice; Mice, Inbred Strains; Nucleic Acid Hybridization; Papilloma; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate; Transcription, Genetic

To elucidate the role and timing of expression of different premalignant and malignant markers in tumor promotion, we correlated alterations in keratin patterns and gamma-glutamyltransferase (GGT) expression with the chromosomal status of individual mouse skin papillomas. Papillomas were induced by 7,12-dimethylbenz[a]anthracene initiation and 12-O-tetradecanoylphorbol-13-acetate promotion. Individual tumors were randomly sampled at 20 and 35 weeks of promotion. Each tumor was cytogenetically analyzed and serial paraffin sections were used for GGT detection, immunoblotting, and immunohistochemistry studies. Monospecific antibodies elicited against keratins K1 (Mr 67,000) and K14 (Mr 55,000) were used to analyze keratin modifications. Most tumors at 20 weeks of promotion, although exhibiting aneuploidy, still presented high levels of the K1 differentiation-associated keratin. Later during promotion those tumors bearing the highest aneuploidy indexes were those that showed a marked decrease in or absence of the K1 protein. Furthermore, those same tumors with the highest levels of genomic alterations also exhibited foci of GGT activity. These results support the idea that the majority of papillomas under continuous promotion are progressing toward malignancy. Aneuploidy seems to precede detectable keratin modifications, and GGT activity appears to be the latest marker to be expressed.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Aneuploidy; Animals; gamma-Glutamyltransferase; Immunoenzyme Techniques; Keratins; Metaphase; Mice; Mice, Inbred Strains; Papilloma; Skin Neoplasms; Tetradecanoylphorbol Acetate

This article describes 31 examples of acantholytic acanthoma, a newly recognized, solitary, benign cutaneous tumor. Acantholytic acanthoma was typically an asymptomatic, keratotic papule or nodule. Patients ranged in age from 32 to 87 years (median 60 years); the ratio of men to women was 2:1; the most frequent clinical diagnosis was keratosis; and half of the growths were on the trunk of the body. Histologically, the lesions showed hyperkeratosis, papillomatosis, and acanthosis. Acantholysis was an outstanding finding in all cases; the patterns resembled pemphigus vulgaris, pemphigus vegetans, superficial pemphigus, or Hailey-Hailey disease, but no patient had evidence of any of these disorders. The term acantholytic is used because acantholysis is the outstanding histologic feature in these neoplasms; acanthoma was chosen because the growths are benign tumors of epidermal keratinocytes. The relationship of acantholytic acanthoma to acantholytic blistering disease is similar to that of solitary lichen planus-like keratosis to lichen planus and epidermolytic acanthoma to bullous congenital ichthyosiform erythroderma.

Topics: Acantholysis; Adult; Aged; Aged, 80 and over; Diagnosis, Differential; Epidermis; Female; Humans; Keratins; Male; Middle Aged; Papilloma; Skin Diseases; Skin Neoplasms

The p117 keratinocyte cell line was derived in culture from chemically induced mouse papillomas. The benignly transformed nature of these cells was demonstrated by their ability to re-form benign papillomas when grafted back onto the animal. Retroviral vectors were used to introduce into the p117 cells three distinct oncogenes: v-Ha-ras, p53, and neu. All three oncogenes were able to induce tumorigenic conversion of the p117 keratinocytes when assayed by subcutaneous injection into nude mice. However, grafting the oncogene-transformed cells onto the back of the mouse revealed important differences in the ability of the three oncogenes to induce a fully malignant phenotype. While the ras-transformed papilloma cells formed aggressive carcinomas, p53 and neu transformation yielded an intermediate phenotype, with formation of large exophytic tumors, not yet invasive but with highly dysplastic features remarkably similar to those of in situ carcinomas. These findings establish a homologous, genetically modifiable cell system in which various stages of malignant transformation can be directly compared.

Topics: Animals; Carcinogenicity Tests; Cell Line, Transformed; Cell Transformation, Neoplastic; Epidermal Cells; Epidermis; Genes, ras; Keratins; Mice; Mice, Nude; Oncogenes; Papilloma; Skin Neoplasms; Skin Transplantation

To investigate the role of transforming growth factor alpha (TGF alpha) in tumor development, we introduced the human TGF alpha (hTGF alpha) cDNA into cultured primary mouse epidermal cells or papilloma cells using a replication-defective retroviral vector and analyzed skin grafts constructed with such cells. Expression of the exogenous gene was confirmed by detection of hTGF alpha mRNA by northern RNA blot analysis, and the secreted hTGF alpha was measured by ELISA of culture supernatants. Tumor cells expressing hTGF alpha produced benign tumors (papillomas), which were 1.5- to 2-fold larger than tumors of parental cells when tested as skin grafts on nude mice. Grafts of normal cells that expressed hTGF alpha produced normal skin. When mixtures of parental tumor cells and normal mouse keratinocytes were grafted to nude mice, papilloma formation was suppressed and tumors that did form were small. Grafts of hTGF alpha-producing papilloma cells combined with either normal epidermal cells or hTGF alpha-producing epidermal cells yielded large tumors. Mixed grafts containing keratinocytes expressing hTGF alpha and parental papilloma cells also produced large tumors. While the tumor size was substantially increased by hTGF alpha expression, the tumors that developed in all groups were histologically benign and reached a stable size 4-5 wk after grafting. These results indicate that expression of hTGF alpha by either tumor cells (autocrine) or adjoining normal cells (paracrine) can stimulate tumor growth, particularly when tumor growth is suppressed by normal tissue. However, expression of this growth factor did not appear to influence tumor progression directly.

Topics: Animals; Blotting, Northern; Blotting, Southern; Cell Line; Disease Models, Animal; Keratins; Mice; Mice, Nude; Neoplasm Transplantation; Papilloma; RNA, Messenger; Skin; Skin Neoplasms; Transfection; Transforming Growth Factors

Murine papilloma cell lines 308 and SP-1 have been used as recipients for transfected oncogenes to investigate malignant conversion. These cell lines express an activated c-rasHa gene with a codon 61 mutation and produce squamous papillomas when transplanted as skin grafts onto nude mice. They are not tumorigenic by subcutaneous injection. Both papilloma cell lines were stably transfected with plasmid DNA containing either a rearranged murine plasmacytoma-derived c-myc (minus exon 1), adenovirus 5 E1A, FBJ v-fos or a human c-fos/FBJ v-fos chimera, using cotransfection with the neomycin resistance gene contained in pSV2neo to select for transformants. Southern and northern blotting analysis confirmed the uptake and expression of exogenous DNA in both G418-selected cell lines and in the derived tumors. Unlike the E1A- and myc-containing plasmids, both fos constructs caused malignant conversion in either cell line, as defined by the squamous cell carcinoma histology of tumors from grafted cells and the development of carcinomas after subcutaneous injection into athymic nude mice. Immunofluorescence analysis for specific keratin gene expression indicated that tumors derived by introduction of either of the fos oncogenes were devoid of staining for K1, a 67 kDa epidermal keratin that is expressed in papillomas but not in squamous carcinomas. Tumors from E1A, myc, or pSV2neo transfectants expressed K1, although in a focal distribution. The malignant phenotype induced by the fos oncogene constructs was not associated with the ability to form agar colonies in vitro or to express gamma-glutamyl transpeptidase in the tumors. Since both 308 and SP-1 were sensitive to the fos oncogene for malignant conversion and insensitive to E1A or myc, it is possible that fos may cooperate with the endogenous-activated c-rasHa gene to convert these cells to malignancy. However, since gamma-glutamyl transpeptidase activity is found in the majority of chemically induced mouse skin carcinomas that possess an activated c-rasHa gene, fos activation may not be a common pathway for spontaneous malignant conversion.

Topics: Animals; Biomarkers, Tumor; Cell Division; Cell Line; Cell Transformation, Neoplastic; Female; Fluorescent Antibody Technique; gamma-Glutamyltransferase; Immunoblotting; Keratins; Mice; Mice, Inbred BALB C; Neoplasm Transplantation; Oncogenes; Papilloma; Plasmids; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins p21(ras); Transfection

We obtained immunohistochemical profiles of several keratin proteins during experimentally induced carcinogenesis in hamster cheek-pouch mucosa using a polyclonal antibody (TK; detecting keratins with molecular masses of 41-65 kilodalton) and two monoclonal antibodies (KL1, 55- to 57-kilodalton keratins; PKK1; 40-, 45- and 52.5-kilodalton keratins). The squamous epithelium of normal pouch mucosa exhibited positive TK staining in all layers, KL1 staining in the spinous layer and PKK1 staining in the basal layer, thus indicating a regional or zonal distribution pattern. Epithelia undergoing basal hyperplasia showed irregular localization of PKK1 binding, while hyperkeratinized lesions exhibited the binding pattern found in normal epithelium. In case of epithelial dysplasia, there was reduced KL1 staining in spinous cells and decreased PKK1 staining in the basal and parabasal layers. Papillomas exhibited a rather zonal distribution of keratin staining. All squamous-cell carcinomas, irrespective of their degree of keratinization and infiltration pattern, showed slight or no PKK1 staining. Such lesions were only positive for KL1-detectable keratins in keratinizing tumour cells and exhibited an irregular distribution of TK binding. The expression of keratin proteins during carcinogenesis in hamster cheek-pouch mucosa may parallel that of keratins in human squamous-cell carcinomas originating in the oral mucosa.

Topics: Animals; Antibodies; Antibodies, Monoclonal; Carcinoma, Squamous Cell; Cricetinae; Histocytochemistry; Hyperplasia; Keratins; Male; Mesocricetus; Methods; Neoplasms, Experimental; Papilloma

Alkaline elution was used to examine DNA single-strand breaks in cultured normal and carcinogen-altered mouse keratinocytes exposed to 12-O-tetradecanoyl phorbol-13-acetate and benzoyl peroxide. Seven cell lines derived from carcinogen-induced mouse skin papillomas and three cell lines derived from N-methyl-N'-nitro-N-nitrosoguanidine-treated non-tumor bearing mouse skin were resistant to phorbol ester-mediated DNA strand breaks after 6 or 24 h. Normal keratinocytes sustained strand breaks after 24 h but not after 6 h. Benzoyl peroxide induced extensive strand breaks in normal keratinocytes at both 6 and 24 h, and this was associated with marked cytotoxicity. In contrast, 9 of 10 cell lines showed complete or partial resistance to strand breaks following benzoyl peroxide exposure. It is proposed that differential resistance to DNA strand breaks and cytotoxicity among normal and carcinogen-altered keratinocytes provides the biological basis for the promoting action of benzoyl peroxide. Furthermore, sublethal DNA damage in preneoplastic or neoplastic keratinocytes may account for the potency of benzoyl peroxide in causing malignant conversion.

Topics: Animals; Benzoyl Peroxide; DNA Damage; Keratins; Methylnitronitrosoguanidine; Mice; Mice, Inbred BALB C; Papilloma; Peroxides; Skin; Skin Neoplasms

A case of multiple clear cell acanthomas in a 64-year-old woman is reported. The clinical and histological findings of this rare entity are consistent with the hypothesis that clear cell acanthomas are benign epidermal tumors. An ultrastructural study was performed with special emphasis on the melanocytic-keratinocytic interaction.

Topics: Epidermis; Female; Histocytochemistry; Humans; Keratins; Leg; Melanocytes; Microscopy, Electron; Middle Aged; Neoplasms, Multiple Primary; Papilloma; Skin; Skin Neoplasms

One of the earliest events after treatment of mouse skin with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) is the induction of ornithine decarboxylase (ODC). Using an immunoperoxidase technique with a rabbit antiserum specific for ODC, the localization of cells containing high levels of ODC following TPA treatment was determined. CD-1 female mice treated with multiple topical applications of TPA and killed 4.5 h after the last TPA treatment exhibited a heterogeneous localization of ODC in this hyperplastic epidermis. The cells which exhibited intense immunostaining were found predominantly in the suprabasal cells lining the hair follicles. This specific ODC staining in cells surrounding hair follicles was inhibited by pretreatment of mice with either retinoic acid or cycloheximide 1 h before TPA treatment. The induction of ODC-specific staining after TPA treatment in hyperplastic mouse skin was transient, since no staining was observed 16 or 24 h after TPA treatment. In contrast, benign papillomas produced by two-stage tumorigenesis contained some cells demonstrating high levels of ODC a week after the last TPA application. These results indicate that both normal mouse epidermal cells as well as tumor tissue display cellular heterogeneity of ODC expression.

Topics: Animals; Enzyme Induction; Epidermal Cells; Epidermis; Female; Keratins; Mice; Mice, Inbred Strains; Ornithine Decarboxylase; Papilloma; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate; Tretinoin

Two monoclonal antibodies, KA 1 and KA 4, raised against human epidermis, were biochemically and immunologically characterized and were shown to react with specific cytokeratin polypeptides. On frozen sections of human mammary gland, these antibodies distinguish between myoepithelial and luminal epithelial cells. We present evidence that in these cells KA 1 antibody recognized cytokeratin 5 and KA 4 antibody cytokeratin 19. In normal mammary tissue, KA 4 antibody invariably reacted with the epithelial cells lining the lumina of acini, ductules, ducts, and sinus. In contrast, KA 1 antibody decorated only the myoepithelial and basal epithelial cells of acini, ducts, and sinus. In ductules, however, KA 1 also stained the luminal cells. All 73 invasive lobular and ductal carcinomas studied reacted with KA 4 antibody; five of these were also positive, apparently in the same tumor cells, with KA 1. The tumor cells of in situ carcinomas were also stained in a homogeneous pattern with KA 4 antibody; KA 1 antibody reacted only with the surrounding myoepithelium. In epithelial hyperplasias, the proliferating cells were decorated by KA 1 and KA 4 antibodies in a heterogeneous pattern. Other antibodies were used for comparison. The results are discussed with respect to epithelial differentiation and pathogenesis and to the application of such antibodies for immunohistodiagnosis of mammary lesions.

Topics: Adenoma; Antibodies, Monoclonal; Antibodies, Neoplasm; Breast Neoplasms; Carcinoma; Carcinoma in Situ; Carcinoma, Intraductal, Noninfiltrating; Epithelium; Female; Fibroma; Fluorescent Antibody Technique; Humans; Keratins; Lactation; Neoplasm Proteins; Papilloma; Pregnancy

The effects of human papillomavirus infection, which can cause laryngeal papillomas, were studied in vitro in laryngeal stratified squamous epithelial cells. Interferon exposure had only minor effects on the outgrowth of primary cells from tissue fragments and the incorporation of tritiated amino acids by first-passage cells. There was a marked decrease in tritiated thymidine incorporation by papilloma cells when cultured in the presence of interferon, but no effect on thymidine incorporation by normal cells. Differentiation of laryngeal papillomas appears to be abnormal. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of keratins showed that the keratins of high relative molecular mass (Mr 51,000 and 59,000) associated with normal laryngeal differentiation were absent from papilloma tissue. Rather, both papilloma tissue and cultured papilloma cells contained a keratin of Mr 53,000 not normally present. Binding of the fluoresceinated lectin peanut agglutinin to cell surfaces suggested that there were alterations in the normal distribution of glycoproteins or glycolipids on papilloma tissues. Filaggrin, a protein synthesized by differentiating cells, was not detectable in most superficial papilloma cells after immunohistochemical staining. These studies strongly suggest that papilloma cells do not differentiate normally. We propose that this defect may be responsible for the hypertrophy of the tissue.

Topics: Adolescent; Adult; Autoradiography; Cell Differentiation; Cells, Cultured; Child; Child, Preschool; DNA, Viral; Electrophoresis, Polyacrylamide Gel; Female; Filaggrin Proteins; Humans; Infant; Infant, Newborn; Interferons; Intermediate Filament Proteins; Keratins; Laryngeal Neoplasms; Male; Middle Aged; Nucleic Acid Hybridization; Papilloma; Papillomaviridae; Tumor Virus Infections

Involucrin has been recognized recently as a marker of terminal differentiation of squamous epithelial cells and also as a useful marker for keratinization; its expression in epithelial tumors of oral and pharyngeal mucosa and skin was examined. Involucrin in normal oral mucosa and skin was restricted to the granular and upper spinous layers and was absent in the basal layer. Hyperkeratosis was characterized by strong positive staining for involucrum in spinous and granular cell layers. A similar pattern was noted in seborrheic keratosis and verruca vulgaris. Condyloma acuminatum specimens revealed slight staining, whereas Paget cells were negative. Calcifying epitheliomas of Malherbe were usually unreactive. Papillomas exhibited the regular distribution of involucrin, as found in normal squamous epithelium. Basal cell carcinomas were generally negative, whereas squamous cell carcinomas showed an irregular distribution of involucrin. Immunohistochemical staining for involucrin may be useful for identification of keratinizing cells in epithelial tumor foci, just as is the use of monoclonal antibody to keratin KL1.

Topics: Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Epithelium; Humans; Immunoenzyme Techniques; Keratins; Mouth Diseases; Mouth Mucosa; Mouth Neoplasms; Papilloma; Pharyngeal Neoplasms; Protein Precursors; Skin Diseases; Skin Neoplasms; Staining and Labeling

Papillomas (40) and squamous cell carcinomas (75) were examined for the presence of three keratin proteins with the use of an immunohistochemical technique. Polyclonal keratin antibody (TK, detecting 41 to 65 kDa keratin) and monoclonal antibodies KL1 and PKK1 (55 to 57 kDa and 41 to 56 kDa, respectively) were used. Squamous epithelium in normal oral mucosa showed marked TK staining in cells of upper strata and relatively slight staining in basal layer cells, moderate KL1 staining in spinous and granular layers and was negative in basal cells. Positive PKK1 staining was noted in cells of the basal layer. Columnar epithelium in the nasal mucosa showed TK staining in all layers, KL1 staining on the apical side of epithelial cells and trace or negative staining in basal layer cells. There was moderate PKK1 staining along the apical side of cells and variable staining in basal cells. Keratin distribution in oral papillomas was similar to that in normal oral epithelium, whereas in nasal and nasopharyngeal papillomas, keratin distribution was restricted to the upper layers. Tonsillar papillomas showed a strong TK reaction, negative KL1 in upper layer cells, and marked PKK1 staining in basal cells. Well-keratinized squamous carcinomas indicated an irregular TK distribution and decreased KL1 and negative PKK1 stainings. Intermediate and poorly differentiated keratinizing squamous carcinoma showed irregular staining patterns for the three classes of keratins studied. Immunohistochemically detectable keratins utilizing monoclonal antibodies were described as useful markers of epithelial tumors of squamous origin. Keratin expression within benign tumors was related to normal regional distribution, whereas in malignant tumors, keratin distribution was irregular in its distribution profile.

Topics: Antibodies, Monoclonal; Carcinoma, Squamous Cell; Esophageal Neoplasms; Humans; Keratins; Mouth Mucosa; Mouth Neoplasms; Nasal Mucosa; Nasopharyngeal Neoplasms; Papilloma

Various parameters of the local cellular response have been studied in 16 laryngeal papillomas from ten patients with recurrent papillomas as well as normal control laryngeal and tracheal tissue by indirect immunofluorescence on frozen sections using monoclonal antibodies specific for T-cell subsets, Langerhans cells (LC) and HLA-DR antigens. Keratinization was investigated with a monoclonal antibody KL1 recognizing an acidic 56.5 Kd keratin, which is a marker of suprabasal cells in stratified squamous epithelium and is absent from the basal layer. The presence of viral antigen was detected with a rabbit antiserum raised against SDS-dissociated purified virus. A mild inflammatory response was observed in most biopsies. Cytotoxic/suppressor T-cells were the predominant cells found in the lesions. Compared with normal epithelium, the number of LC was dramatically reduced in the papillomatous epithelium. High densities of HLA-DR-positive cells were found mainly in the corium. The keratinization process was disturbed in most specimens in that both basal and suprabasal compartments reacted positively with the KL1 monoclonal antibody. Viral antigen was present in the nucleus of very occasional epithelial cells in some samples.

Topics: Adolescent; Adult; Antibodies, Monoclonal; Antigens, Neoplasm; Antigens, Viral; Child; Child, Preschool; Fluorescent Antibody Technique; Humans; Immunity, Cellular; Keratins; Laryngeal Neoplasms; Papilloma; T-Lymphocytes

The development of malignant tumors in carcinogen-treated mouse skin appears to involve several genetic changes. Genetic changes which initiate the process are believed to induce alterations in the normal pattern of epidermal differentiation, resulting in the formation of benign tumors, i.e., epidermal papillomas. Subsequent changes appear to be required for the malignant conversion of papillomas to epidermal, squamous-cell carcinomas. Activation of the rasHa gene occurs frequently in chemically induced benign skin papillomas as well as squamous cell carcinomas and thus may represent one mechanism to achieve the initiation step. In the present study, we analyzed several cell lines derived from chemically induced mouse skin papillomas for the presence of transforming oncogenes by transfection of their DNA into NIH 3T3 cells. These papilloma cell lines exhibit an altered differentiation program, i.e., the ability to proliferate under culture conditions favoring terminal differentiation. When DNA from six separate cell lines was tested in the NIH 3T3 transfection assay, active transforming activity was not detected. However, when the EJ rasHa gene was introduced into three of the papilloma cell lines by DNA transfection, transfectants showed an enhanced capacity to proliferate under differentiating culture conditions and formed rapidly growing, anaplastic carcinomas in nude mice. Our findings suggest that in some papilloma cells, a genetic change distinct from rasHa activation may produce an altered differentiation program associated with the initiation step, and this genetic alteration may act in a cooperating fashion with an activated ras gene to result in malignant progression.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Cell Line; Cell Transformation, Neoplastic; Cells, Cultured; Keratins; Mice; Mice, Inbred Strains; Mice, Nude; Neoplasm Transplantation; Oncogenes; Papilloma; Skin

A series of conformationally restricted retinoids has been synthesized and assayed for biological activity. These compounds have aromatic rings in place of selected double bonds of the tetraene side-chain of retinoic acid and could be considered as analogues of retinoic acid in which some of the double bonds possess s-cis topology. Thus far, analogues in which the bonds corresponding to the (5,7E)-, (7,9E)-, (9,11,13E)- and (11,13E)-double bond systems of retinoic acid are restricted to a cisoid conformation have been studied. Analogues were screened for their ability to reverse keratinization in hamster tracheal organ culture and to inhibit the induction of ornithine decarboxylase in mouse epidermis. Selected compounds were also screened in the antipapilloma assay in mice. The toxicity of some analogues on intraperitoneal injection in mice was determined.

Topics: Animals; Biological Assay; Cricetinae; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Enzyme Induction; Epithelium; Keratins; Lethal Dose 50; Mice; Molecular Conformation; Ornithine Decarboxylase Inhibitors; Papilloma; Retinoids; Tretinoin

Three hundred rat bladders bearing tumors induced by N-butyl-N-4-(OH)butyl-nitrosamine (BBN) were examined by routine histologic study and immunohistochemical staining of intermediate filament types. Smaller lesions were similar to human urothelial dysplasia histologically and immunohistochemically. Progression of the lesions demonstrated large exophytic papillomas with extensive endophytic epithelial growth into abundant stroma. These lesions showed increasing predominance of squamous over transitional elements. Immunohistochemical findings confirmed these results and also demonstrated that morphologically indifferent cells, even in early lesions, express heavier cytokeratins characteristic of keratinizing squamous epithelium. These results demonstrate that BBN-induced bladder tumors show marked quantitative and qualitative differences from the most common, purely transitional, human bladder carcinomas. However, the development in BBN-treated rat bladders of two tumor types, squamous and transitional, from an altered urothelium may serve as an attractive model for further study of the molecular genetics of keratin expression.

Topics: Animals; Antibodies, Monoclonal; Butylhydroxybutylnitrosamine; Carcinoma, Squamous Cell; Carcinoma, Transitional Cell; Epithelium; Fluorescent Antibody Technique; Histocytochemistry; Keratins; Male; Papilloma; Rats; Rats, Inbred ACI; Urinary Bladder Neoplasms; Vimentin

Alterations in the pattern of epidermal differentiation and proliferation occur during mouse skin carcinogenesis. We have used cDNA clones corresponding to the major keratin subunits synthesized in differentiating epidermal cells (Mr 67,000 and 59,000) and in proliferating epidermal cells (Mr 60,000, 55,000, and 50,000) to study changes in keratin gene transcript levels in mouse epidermis exposed to tumor promoters. The same probes were used to characterize the keratin expression patterns in benign and malignant skin tumors. A single topical treatment with 12-O-tetradecanoylphorbol-13-acetate caused a rapid initial decrease in the epidermal transcript levels corresponding to the Mr 67,000 and 59,000 keratin subunits. By 48 h the transcript level for the Mr 67,000 keratin subunit was restored to control values, whereas the transcript levels for the Mr 59,000 subunit returned to control at a slower rate. In contrast, the transcript level for the Mr 55,000 subunit was increased substantially 12- 48 h after treatment, the Mr 50,000 subunit transcript increased to a lesser extent, and the Mr 60,000 subunit message was transiently decreased at 12 h but returned to the level of solvent-treated skin by 24 h. Single exposure to the incomplete tumor promoters 4-O-methyl-12-O-tetradecanoylphorbol-13-acetate, the ionophore A23187, and mezerein induced changes in keratin gene transcripts similar to those of 12-O-tetradecanoylphorbol-13-acetate. The antipromoter fluocinolone acetonide, administered with 12-O-tetradecanoylphorbol-13-acetate, partially inhibited the decrease in the Mr 59,000 and 67,000 transcripts and completely inhibited the increase in the Mr 55,000 transcript. In skin papillomas produced by initiation and promotion, keratin gene expression was similar to normal skin, with the exception of a two-fold increase in the transcript levels for the Mr 55,000 keratin subunit. However, in carcinomas, the transcript levels for the Mr 67,000 and 59,000 subunits were only 1-3% of those observed in untreated mouse epidermis. In concert with other data, the rapid and selective loss of transcripts for differentiation-related keratins after exposure to both complete and incomplete tumor promoters is most consistent with an accelerated rate of maturation in differentiating keratinocytes, resulting in the rapid production of transcript-depleted fully mature squames. The enhanced level of Mr 55,000 transcripts suggests a concomitant increase in the number of all cells or

Topics: Animals; Carcinoma; Female; Fluocinolone Acetonide; Gene Expression Regulation; Keratins; Mice; Molecular Weight; Papilloma; Phorbols; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate; Transcription, Genetic

Papillomas induced by standard initiation-promotion protocols progress to carcinomas at a low frequency. Experimental protocols were developed to elicit papillomas with a higher probability of malignant conversion. SENCAR mice initiated by 7,12-dimethylbenz[a]anthracene were promoted by treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA) for 5, 10, 20 or 40 weeks. With promotion for 10 weeks or more, a peak of papilloma incidence at 16-20 weeks was followed by a 35-40% decrease within 3 months. A much lower papilloma response was seen in mice promoted for 5 weeks, but these papillomas persisted. The yield of malignant tumors was similar in all four groups, with 20-25 carcinomas per group of 30 mice. Thus, the papillomas induced by the first few TPA treatments are much more likely to progress to carcinomas than those which appear later. In a separate study, initiated Charles River CD-1 mice were promoted with TPA for either 12 or 52 weeks. Acetone solvent treatment was begun at Week 13 in the group treated 12 weeks with TPA. At Week 16, the papilloma incidence was identical in the two groups of mice. However, by Week 28, the papilloma yield in the continuous TPA group had increased and was twice that of the acetone group, in which papillomas had regressed. The first carcinoma arose 14 weeks earlier with continuous TPA, but the final number of carcinomas per group of 40 mice was 17 with TPA and 20 with acetone. Neither the increase in papillomas in TPA-treated mice nor the regression of papillomas after cessation of promotion with TPA affected the final carcinoma yield. This result suggests that TPA-dependent papillomas are very unlikely to progress to carcinomas. In a third experiment, promotion of initiated SENCAR mice with mezerein resulted in a small number of papillomas which had a much higher probability of progression to carcinomas than the large number of papillomas promoted by TPA. The ability to induce papillomas promoted by TPA. The ability to induce papillomas with a known probability of conversion to carcinomas will facilitate the identification of markers associated with malignant progression.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinoma; Cocarcinogenesis; Diterpenes; DNA; Female; Keratins; Mice; Mice, Inbred Strains; Papilloma; Probability; Terpenes; Tetradecanoylphorbol Acetate; Time Factors

Seventy-six cases of tumorlike and neoplastic lesions from epidermis and oral epithelium were analyzed by a histochemical technique for the demonstration of keratin. Formalin-fixed paraffin sections were reacted with rabbit antihuman keratin antiserum (dilution of 1:40). The types of distribution of keratin in cells of lesions were classified into five categories: (1) regional, as found in normal squamous epithelia and benign hyperkeratinized lesions, and papilloma, and keratinized squamous cell carcinoma; (2) total, as seen in intensely keratinized lesions, such as verruca vulgaris and highly keratinized squamous cell carcinoma; (3) negative, as displayed by basal cell carcinoma; (4) scattered, as in the most poorly differentiated squamous cell carcinomas; and (5) mixed cellular, as found in both poorly and moderately differentiated squamous cell carcinomas.

Topics: Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Dermatitis, Seborrheic; Epithelium; Humans; Immunoenzyme Techniques; Keratins; Keratosis; Lectins; Mouth Neoplasms; Papilloma; Protein Binding; Skin Neoplasms; Warts

In normal skin, cytokeratin polypeptides are expressed in different cell-type-specific patterns, in the keratinocytes of the different epidermal cell strata as well as in different lateral epithelial domains. Using light microscopically controlled microdissection of defined regions from frozen sections of biopsies, we have prepared cytoskeletons of various benign and malignant keratinocyte-derived tumors of human skin and analyzed their cytokeratin polypeptide patterns by two-dimensional gel electrophoresis. Premalignant fibroepitheliomas and basal cell epitheliomas display a relatively simple cytokeratin pattern (cytokeratins nos. 5, 14, 15, and 17). Pseudocarcinomatous hyperplasia, some squamous cell carcinomas, and a certain subtype of condylomata acuminata present a hair-follicle-like pattern (nos. 5, 6, 14, 16, 17). In addition to these components, variable, mostly low amounts of cytokeratins nos. 1 (Mr 68,000), and 11 are detected in most squamous cell carcinomas, in keratoacanthomas, verruca vulgaris, and another type of condylomata acuminata. In molluscum contagiosum, verruca plana, solar keratosis, and seborrheic keratosis, the cytokeratin expression is shifted more towards the normal epidermal pattern (polypeptides nos. 1, 2, 5, 10, 11, 14, 15 and traces of nos. 6 and 16 in the latter two tumors). No tumor-specific cytokeratins have been found. We conclude that keratinocyte-derived skin tumors contain various combinations of cytokeratins of the subset typical for normal keratinocytes of skin, but no cytokeratins typical for internal, simple epithelia. Different groups of tumors can be distinguished by their specific cytokeratin patterns. Possible applications of cytokeratin typing in clinical diagnosis are discussed.

Topics: Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Condylomata Acuminata; Electrophoresis, Polyacrylamide Gel; Humans; Keratins; Keratoacanthoma; Keratosis; Molecular Weight; Molluscum Contagiosum; Papilloma; Peptides; Skin; Skin Neoplasms; Warts

Topics: Animals; Dimethylnitrosamine; Epidermis; Keratins; Male; Microscopy, Electron, Scanning; Papilloma; Rats; Stomach Neoplasms; Zinc

A series of conformationally restricted retinoids was synthesized and screened in two assays used to measure the ability of retinoids to control cell differentiation, namely, the reversal of keratinization in tracheal organ culture from vitamin A deficient hamsters and the inhibition of the induction of mouse epidermal ornithine decarboxylase by a tumor promoter. These compounds had bonds corresponding to selected bonds of the E-tetraene chain of retinoic acid (1) held in a planar cisoid conformation by inclusion in an aromatic ring. The meta-substituted analogue 3 of 4-[(E)-2-methyl-4-(2,6,6-trimethylcyclohexenyl)-1,3-butadienyl+ ++]benzoic acid (2) was far less active than 2 in both assays. In contrast, the vinyl homologue of 2 (4) and the 7,8-dihydro and 7,8-methano analogues (5 and 6) had activity comparable to that of 2. Analogues of 4-[(E)-2-(1,1,4,4-tetramethyl-1,2,3,4-tetrahydro-6-naphthyl)propenyl] benzoic acid (7) were also screened. Replacement of the tetrahydronaphthalene ring of 7 by a benzonorbornenyl group (9) significantly reduced activity, as did removal of the vinylic methyl group from 9 (10). Replacement of the propenyl group of 9 by a cyclopropane ring (12) also reduced activity. Replacement of the tetrahydronaphthalene ring of 7 by 4,4-dimethyl-3,4-dihydro-2H-1-benzopyran and -benzothiopyran rings (13 and 14) also decreased activity. Inclusion of the 7,9 double bond system of 1 in an aromatic ring (15 and 16) reduced activity, whereas inclusion of the 5,7 double bond system in an aromatic ring enhanced activity (7 and 19). Inclusion of the 11,13 and 9,11,13 double bond systems in aromatic rings (2 and 18) also reduced activity below that of 1. Retinoic acid, 7, 13, 14, and 19 inhibited papilloma tumor formation in mice. Toxicity testing indicated that 7 was more toxic than 1, 13, 14, and 19, 19 was more toxic than 1, and 13 and 14 were less toxic than 1.

Topics: Animals; Cell Differentiation; Chemical Phenomena; Chemistry; Female; Keratins; Mice; Organ Culture Techniques; Ornithine Decarboxylase Inhibitors; Papilloma; Retinoids; Skin; Structure-Activity Relationship; Trachea; Vitamin A Deficiency

Topics: Animals; Cell Transformation, Neoplastic; Etretinate; Female; Humans; Keratins; Male; Middle Aged; Neoplasm Recurrence, Local; Papilloma; Skin Neoplasms; Tretinoin; Urinary Bladder Neoplasms

gamma-Glutamyltransferase (GGT), an enzyme not found in normal adult epidermis, was detected in most skin papillomas larger than 13 mm in diameter and in all squamous carcinomas induced by 7,12-dimethylbenz[a]anthracene initiation and 12-O-tetradecanoylphorbol 13-acetate promotion in noninbred Sencar mice. Furthermore, these GGT-positive lesions were also characterized by a marked decrease or absence of high-molecular-weight components of epidermal keratin. Since these characteristics are common to both carcinomas and large papillomas but are practically undetectable in normal epidermis and small papillomas, GGT activity and lack of high-molecular-weight keratin components seem to be good indicators of tumor progression, i.e., from papilloma to squamous carcinoma.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Acyltransferases; Animals; Carcinoma, Squamous Cell; Female; Histocytochemistry; Keratins; Mice; Mice, Inbred Strains; Neoplasms, Experimental; Papilloma; Skin Neoplasms; Tetradecanoylphorbol Acetate; Transglutaminases

To elucidate the role of keratin modification in tumor promotion, we investigated the keratin polypeptide patterns of mouse epidermis, papillomas, and carcinomas throughout an initiation-promotion experiment. The epidermal keratin modifications induced by repetitive 12-O-tetradecanoylphorbol-13-acetate treatments in both initiated and noninitiated mouse skin were essentially identical to those observed with a single 12-O-tetradecanoylphorbol-13-acetate application. These changes were even more pronounced in epidermal papillomas. In addition, the keratins of the papillomas displayed greater charge heterogeneity, particularly among the high-molecular-weight keratins (Mr 60,000 to 62,000). As the experiment progressed, there appeared to be a selective loss of one group of high-molecular-weight keratins (Mr 62,000) in some of the papillomas. Interestingly, the carcinomas that appeared at this time had significant reduction in both groups of high-molecular-weight keratins. In fact, the keratin profiles of carcinomas were very similar to the patterns observed in basal cells after a single 12-O-tetradecanoylphorbol-13-acetate treatment of adult epidermis. This may indicate that the program of keratin expression of a carcinoma becomes permanently fixed at a basal cell pattern. Changes in keratin patterns may serve as a biochemical marker of malignant progression in mouse epidermis.

Topics: Animals; Carcinogens; Carcinoma; Female; Keratins; Mice; Mice, Inbred Strains; Molecular Weight; Neoplasms, Experimental; Papilloma; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate

Topics: Cryosurgery; Humans; Keratins; Microscopy, Electron; Papilloma; Papillomaviridae; Postoperative Period; Skin Neoplasms

A clinical and histopathologic analysis of 464 oral squamous cell papillomas is presented. Data on age, sex, race, location, clinical appearance, duration, recurrence, and clinical diagnosis are reviewed. One hundred seventy-six of the 464 specimens were examined for hyperkeratosis, character and amount of inflammatory infiltrate, and evidence of cellular atypia. The trends seen in this study support claims made by previous authors regarding incidence and inflammatory involvement. The data support a slightly higher occurrence rate in males than in females and in white as opposed to black patients. Papillomas were most abundant on the palatal complex, dorsum and lateral tongue borders, and lower lips, respectively. Confusion of papilloma for fibroma in the clinical diagnosis was less common than expected. Recurrence rate and incidence of multiple papillomas were low. Histologic study revealed a tendency for hyperkeratotic lesions to arise from nonkeratinized oral sites. Cellular atypia was found, but it is still unclear whether these changes are preneoplastic or due to an increased growth rate.

Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Female; Humans; Hyperplasia; Inflammation; Keratins; Male; Middle Aged; Mouth Mucosa; Mouth Neoplasms; Neoplasm Recurrence, Local; Papilloma; Time Factors

In the case of viral acanthomas, the stratum spinosum and granulosum presents ballooned cells which contain all transitional stages from multivesicular bodies (MVB) to keratinosomes. A particularity in condylomata acuminata are the "wagon-wheel" bodies. These structures are typical for the non keratinazed squamous epithelium. The participation of intercellular extruded "wagon-wheel" bodies, MVB and atypical keratinosomes on an irregular baso-apical diffusion-barrier in the epidermis of cases with viral acanthomas has been discussed. On the basis of the relation seen between MVB and the Golgi-apparatus, their transition to partially atypical keratinosomes in cases of viral acanthomas and their "expulsion" into the intercellular space could indicate that in keratinozytes the enzymatically regulated feed-back between the cellular surface and the capability to synthesize is changed by viral agents. The interference appears to manifest itself in the Golgi-apparatus and also appears to be "specified" by the terrain present.

Topics: Animals; Condylomata Acuminata; Cytoplasmic Granules; Epithelium; Humans; Keratins; Laryngeal Neoplasms; Microscopy, Electron; Papilloma; Skin Diseases; Skin Neoplasms; Tumor Virus Infections; Warts

Topics: Adolescent; Adult; Aged; Carcinoma, Squamous Cell; Cell Nucleus; Cytoplasmic Granules; Diagnosis, Differential; Female; Humans; Keratins; Leg; Male; Middle Aged; Papilloma; Skin Neoplasms

Topics: Animals; Cell Differentiation; Fasting; Keratins; Mice; Mitosis; Neoplasms, Experimental; Papilloma; Skin Neoplasms

Topics: Adolescent; Adult; Aged; Basement Membrane; Cell Division; Cell Nucleus; Child; Cilia; Cytoplasm; Epithelium; Female; Glycogen; Humans; Inclusion Bodies; Keratins; Male; Middle Aged; Mucus; Nasal Mucosa; Nasal Septum; Neoplasm Recurrence, Local; Nose; Nose Neoplasms; Papilloma; Paranasal Sinus Neoplasms; Paranasal Sinuses

Topics: Animals; Dermoid Cyst; Epithelium; Female; Fibroblasts; Hair; Histiocytes; Keratins; Male; Mice; Neoplasm Transplantation; Neoplasms, Experimental; Papilloma; Skin; Skin Neoplasms; Transplantation, Homologous; Warts

Topics: Animals; Cattle; Cattle Diseases; Female; Horns; Keratins; Mammary Glands, Animal; Papilloma; Skin Neoplasms

Topics: Adult; Humans; Keratins; Male; Papilloma; Penile Diseases; Penile Neoplasms; Sclerosis

Topics: Animals; Carcinoma; Keratins; Neoplasms; Papilloma; Rabbits; Tumor Virus Infections