metallothionein and Skin-Neoplasms

Photoaging and photocarcinogenesis are the two Janus faces of skin photodamage. Reactivity-based design of prototype agents that antagonize, modulate and reverse the chemistry of skin photodamage holds promise in delivering unprecedented therapeutic benefit. In contrast to structure-based approaches that use selective ligands to target macromolecules, reactivity-based drug discovery uses chemical reagents as therapeutics to target reactive chemical species as key mediators of skin photo-oxidative stress. The following classes of reactivity-based agents for skin photoprotection can be distinguished based on their mechanism of action: direct antagonists of photo-oxidative stress (sunscreens, quenchers of photo-excited states, antioxidants, redox modulators and glycation inhibitors) and skin photo-adaptation inducers (nuclear factor erythroid 2-related factor 2 [Nrf2] activators, heat-shock response inducers and metallothionein inducers).

Topics: Animals; Antioxidants; Chelating Agents; Drug Design; Glycation End Products, Advanced; Glycosylation; Heat-Shock Response; Humans; Metallothionein; Neoplasms, Radiation-Induced; NF-E2-Related Factor 2; Oxidation-Reduction; Oxidative Stress; Photochemistry; Reactive Oxygen Species; Signal Transduction; Skin; Skin Aging; Skin Neoplasms; Sunburn; Sunscreening Agents; Ultraviolet Rays; Up-Regulation

The mechanisms underlying UV-induced immunosuppression and the development of UV-induced skin cancer have been intensively investigated for decades. In particular, UV-induced DNA damage and UV-induced suppression of cellular immune responses were analyzed in great detail. During this time, several cellular and genetic pathways were identified, that are involved in photoimmunology and photocarcinogenesis. However, the direct effects of the complex UV-induced pathways on immunosuppression or on cutaneous tumor generation in vivo have not been able to be characterized with certainty so far. With the increasing availability of mutant mice that lack or overexpress certain genes, more information can be obtained with respect to the functional importance of individual gene products and the signaling pathways involved in UV-mediated immunomodulation and cancer development. This article is an overview of the results of UV-induced immunosuppression and photocarcinogenesis experiments obtained in different mutant mice.

Topics: Abatacept; Animals; DNA-Binding Proteins; Genes, p53; Genes, ras; Immune Tolerance; Immunoconjugates; Metallothionein; Mice; Mice, Transgenic; Monophenol Monooxygenase; Neoplasms, Radiation-Induced; Promoter Regions, Genetic; Receptors, Tumor Necrosis Factor; Skin Neoplasms; Ultraviolet Rays; Xeroderma Pigmentosum Group A Protein

Distinguishing primary cancer from a metastasis is a fundamental task in surgical pathology that has crucial therapeutic and prognostic implications. When metastatic melanoma involves the skin and extends into the epidermis (epidermotropic), differentiating it from primary cutaneous melanoma may be particularly difficult. Early investigators dismissed this issue as a nonproblem and dogmatically declared that junctional change was requisite for the diagnosis of primary cutaneous melanoma. Epidermotropic metastases of malignant melanoma (EMMM) are now recognized to have many features in common with primary melanoma, which can include involvement of the dermal-epidermal junction, extension of the intraepidermal component beyond the dermal component, and even an epidermal-only pattern. This article traces the evolution in criteria used to diagnose EMMM and highlights why much of the original thinking is no longer accepted. Current concepts in EMMM morphology are elaborated and illustrated. The role of immunomicroscopy and molecular pathology in the detection of EMMM is also discussed.

Topics: Adult; Diagnosis, Differential; DNA, Neoplasm; Epidermis; Female; Humans; Intercellular Adhesion Molecule-1; Male; Melanoma; Metallothionein; Middle Aged; Neoplasms, Multiple Primary; Reverse Transcriptase Polymerase Chain Reaction; Skin Neoplasms

When a CpG island (CGI; a dense cluster of CpGs) located in the 5' region of a gene is methylated, its transcription is suppressed. Tumorigenesis of melanoma is associated with trace elements. Metallothionein 1A is closely associated with the metabolism of trace elements. However, little is known about the metallothionein 1A gene (MT1A) in melanoma.. The purpose is to reveal the methylation and expression status of MT1A in melanoma.. Quantitative real-time methylation-specific PCR (RT-MSP) and bisulfite sequencing were performed to examine MT1A methylation status. Quantitative real-time reverse transcription-PCR (RT-PCR) was performed to examine MT1A expression.. Some melanoma cell lines exhibited high methylation levels of the CGI located in the 5' region of MT1A (5' MT1A CGI) with suppression of MT1A. Other melanoma cell lines and normal cultured melanocytes exhibited low methylation levels of 5' MT1A CGI with expression of MT1A. Treatment with a demethylating agent resulted in transcriptional induction of MT1A in the melanoma cell lines SK-MEL-5 and G-361 with high methylation levels prior to treatment. The methylation levels of 5' MT1A CGI ranged widely from 0.0% to 91.4% in 21 clinical melanoma samples but showed a narrow, low range from 0.0% to 6.4% in 23 clinical melanocytic nevus samples. Data of bisulfite sequencing was generally compatible with those of RT-MSP. The methylation levels ranged according to the types of melanoma (Kruskal-Wallis test, P=0.047).. MT1A is aberrantly silenced by DNA methylation of 5' MT1A CGI in melanoma.

Topics: 5' Untranslated Regions; Adolescent; Adult; Aged; Aged, 80 and over; Azacitidine; Cell Line, Tumor; Child; CpG Islands; Decitabine; DNA Methylation; Female; Gene Expression Regulation, Neoplastic; Gene Silencing; Humans; Male; Melanocytes; Melanoma; Metallothionein; Middle Aged; Nevus, Pigmented; Real-Time Polymerase Chain Reaction; Skin Neoplasms; Young Adult

A genome organizer protein, special AT-rich sequence binding protein 1, (SATB1), was recently shown to play an important role in the development and spread of various malignancies. Metallothioneins I and II (MTI/II) are multifunctional proteins involved, among others, in cell proliferation and apoptosis resistance in tumors. The role and relevance of these factors in mycosis fungoides (MF), the most common primary cutaneous T-cell lymphoma, is not fully understood. The aim of the present analysis was to evaluate the expression and potential correlation of SATB1, MTI/II and Ki-67 with clinicopathological data in MF.. We performed immunohistochemical analysis for SATB1, MTI/II and Ki-67 on 90 cases of MF and 19 controls (chronic benign dermatoses). The expression of SATB1 and Ki-67 was analyzed in cancer cell nuclei, whereas nuclear and cytoplasmic expressions of MTI/II were scored separately (nMT, cMT; respectively).. We recorded a significantly higher expression of SATB1 and cMT in MF compared to the control group (p<0.002, p=0.04, respectively, Student's t-test). We also noted significant differences in the mean (±SD) expression of nMT and cMT in advanced MF compared to early MF, (1.4±1.3 vs. 0.9±0.9, 4.1±3.8 vs. 2.5±2.9, respectively; p=0.04 for both). Similarly, Ki-67 expression was significantly higher in advanced MF (p<0.01). The expression of SATB1, cMT and Ki-67 was significantly higher in more infiltrating skin lesions (p<0.001, p=0.08 and p<0.001, respectively). Regarding extracutaneous involvement, a higher expression of SATB1, nMT, cMT and Ki-67 was found in patients with clinical or histological involvement of lymph nodes (N1-3 vs. N0) (p<0.001, p=0.002, p<0.001 and p=0.1, respectively). A marked correlation was observed between SATB1 and Ki-67 (Spearman correlation test: r=0.53, p<0.001). No associations between SATB1, nMT and cMT expression and demographic data nor overall survival were found.. Our study provides data on the differences in the expression of SATB1 and cMT regarding differential diagnosis of MF and tumor-node-metastasis-blood staging. Additionally, our report documented significantly different expression levels of MTI/II and Ki-67 according to the advancement of the disease. In view of these data, the role of studied factors in the development of this type of cutaneous T-cell lymphoma is postulated. Our results indicate that both SATB1 and MTI/II may be of diagnostic value, but our study revealed no prognostic significance; however, given the small number of reports focusing on this topic, further studies are required.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Female; Humans; Ki-67 Antigen; Male; Matrix Attachment Region Binding Proteins; Metallothionein; Middle Aged; Mycosis Fungoides; Prognosis; Skin Neoplasms; Young Adult

Odontogenic tumors exhibited variable biologica behaviors. Metallothionein (MT) is correlated with the cellular homeostasis of essential metals, cellular differentiation, and proliferation. The core goals of this study are (i) to report and to compare MT expression among benign epithelial odontogenic tumors; (ii) to correlate MT with cellular proliferation index; and (iii) to evaluate the influence of the inflammatory infiltrate on MT expression.. Ten cases of solid ameloblastomas (SABs), 4 squamous odontogenic tumors (SOTs), 5 adenomatoid odontogenic tumors (AOTs), and 3 calcifying epithelial odontogenic tumors (CEOTs) were subjected to immunohistochemical to anti-MT, anti-Ki-67, and anti-PCNA. Statistical analysis was performed using BioEstat(®) 4.0.. Metallothionein staining was found to be the highest in the SABs (93.1%), followed by SOTs (52.9%), AOTs (38.4%), and CEOTs (0%). MT staining exhibited statistically significant differences between the SABs and the SOTs (P = 0.0047) and the AOTs (P = 0.0022). A weak-to-strong positive correlation between IMT and IK or IP was observed in SABs and SOTs, whereas a strong negative correlation was observed in AOTs. No differences in IMT, IK, and IP were observed between inflammation groups A and B.. The increased MT expression observed in the SABs might be correlated with clinical behavior (local invasiveness and high rate of recurrence). In the SABs and SOTs, MT plays a role in the stimulation of cellular proliferation. In contrast, MT can inhibit cellular proliferation in the AOT. The IMT, IK, and IP are not affected by inflammation.

Topics: Ameloblastoma; Cell Proliferation; Connective Tissue; Epithelial Cells; Humans; Immunohistochemistry; Ki-67 Antigen; Lymphocytes; Metallothionein; Neoplasm Invasiveness; Neoplasm Recurrence, Local; Odontogenic Tumor, Squamous; Odontogenic Tumors; Plasma Cells; Proliferating Cell Nuclear Antigen; Skin Neoplasms

The formation of metastases and the efficacy of systemic therapies in cutaneous malignant melanoma (CMM) depend on the characteristics of the tumour cells and the host immune response. Aberrant expression of metallothionein (MT) has been observed in several types of cancers with poor prognoses.. To perform an immunohistochemical study on primary CMM comparing the MT expression of tumours without metastases (n = 23) to that of samples with haematogenous metastases (n = 23) and to examine the correlation between MT staining and immunological markers relevant in CMM progression.. The immunohistochemical labelling of different tumour sections was analysed using tissue microarrays for the evaluation of the suitability of this method in future studies.. Our results suggest that MT overexpression is significantly more frequent in primary CMM with haematogenous metastases (P = 0.018) and that the overexpression is independent of the Breslow tumour thickness (R = 0.102, P = 0.501). Interestingly, MT overexpression of the tumour cells was correlated with the presence of tumour-infiltrating CD68(+) macrophages (P = 0.003), a known predictive factor for melanoma progression, thereby suggesting a role for MT in the development of a defective host immune response. Furthermore, the presence of CD163(+) macrophages infiltrating the tumours correlated with metastasis formation (P < 0.001), whereas the presence CD1a(+) dendritic cells surrounding the tumours was associated with a lower risk of haematogenous spread (P = 0.003).. Our results demonstrate that MT may represent a suitable prognostic factor that can characterize the metastasising ability of CMM and the tumour-promoting host immune response.

Topics: Antigens, CD; Disease Progression; Female; Humans; Macrophages; Male; Melanoma; Metallothionein; Neoplasm Metastasis; Risk Factors; Skin Neoplasms

Multiple functional implications have been suggested for a limited number of chemokines and their cognate receptors in melanoma pathogenesis. The purpose of this study was to investigate the potential role of the chemokine receptors CXCR4, CCR7, CCR9, and CCR10 as prognostic markers in human primary cutaneous melanoma. Chemokine receptor expression was analyzed by immunohistochemistry in a total of 38 patients with cutaneous melanoma. Results were statistically correlated with melanoma features and clinical disease progression. No significant correlation between overexpression of CXCR4 or CCR9 and survival or prognosis was found. CCR7 overexpression was associated with significantly lower survival (0.005 log rank) and shorter time to progression (0.009 log rank)-similar to CCR10 overexpression (lower survival: 0.001 log rank, shorter time to progression: 0.002 log rank). In addition, CCR7 overexpression correlated with expression of metallothionein, while CCR10 seems to be associated with cerebral metastases. Two chemokine receptors permitting the identification of high-risk patients were identified: CCR7 and CCR10 overexpressions were found to be associated with a worse outcome of disease course independent of Breslow's tumor thickness and Clark level, thus representing possible additional prognostic markers.

Topics: Biomarkers; Disease Progression; Female; Humans; Male; Melanoma; Metallothionein; Prognosis; Receptors, CCR; Receptors, CCR10; Receptors, CCR7; Receptors, CXCR4; Severity of Illness Index; Skin Neoplasms

The aim of the present study was to evaluate, by immunohistochemical staining, metallothionein expression in normal, benign and malignant canine apocrine gland tissues and to correlate the protein expression with the histological grade of malignancy.. MT immunostaining was evaluated in 25 formalin-fixed and paraffin-embedded canine apocrine glands (2 normal and 23 neoplastic). Moreover, we evaluated quantitative expression of MT in normal and neoplastic cells by western blotting.. a marked increase in MT expression was observed in neoplastic, compared to normal samples as well as in malignant compared to benign tumors. Western blotting analysis revealed one major protein band of approximately 14 kDa in normal, as well as in the neoplastic, tissues.. We conclude that MT expression appears to be a potential biomarker for the diagnosis of canine apocrine gland tumors and may also assist in the better understanding of the evolution of this neoplasia.

Topics: Animals; Apocrine Glands; Blotting, Western; Dogs; Metallothionein; Skin Neoplasms

Metallothioneins (MT) are low-molecular weight proteins implicated in heavy metal detoxification, zinc and cooper homeostasis and cell protection against free radicals. In variety of cancers MT-overexpression was shown, but there are just a few studies on the role of MT in skin carcinogenesis. Current study was undertaken to evaluate MT and Ki-67 expression in pre-cancerous skin lesions as well as in fully developed skin cancers. 73 squamous cell carcinomas (SCC), 23 actinic keratoses (AK) and 20 normal skin samples were included in the study. In obtained paraffin sections immunohistochemical reactions were performed. MT-expression in SCC (mean 2.89 ± 1.83) was significantly higher than in AK (mean 1.69 ± 1.26)(p = 0.006) and higher than in normal skin (mean 2 ± 0.79) (p = 0.0075). The MT-expression positively correlated with Ki-67 expression (R = 0.28; p = 0.017) in SCC and in AK (R = 0.49; p = 0.018). Various clinico-pathological variables, e.g. morphology, size of lesions and the depth of neoplastic infiltration were not associated to MT-expression in both SCC and AK. The grade of histological differentiation of SCC correlated positively with Ki-67 antigen (p < 0.001) and did not correlate with MT-expression (p = 0.06). Ki-67 expression was higher in SCC and in AK than in healthy skin (p = 0,003). In SCC and in AK expression of Ki-67 antigen correlated positively with MT-expression (respectively p = 0.017 and p = 0.018). MT may serve as a good markers of proliferation in SCC and AK. MT-overexpression in SCC may suggest a potential role of MT in skin carcinogenesis.

Topics: Aged; Aged, 80 and over; Biomarkers, Tumor; Carcinoma, Squamous Cell; Female; Humans; Immunohistochemistry; Keratosis, Actinic; Ki-67 Antigen; Male; Metallothionein; Middle Aged; Skin Neoplasms

Basal cell carcinoma (BCC) is the most frequent skin cancer, with many different histological subtypes. Recent studies have investigated the expression of proliferative markers, but little is known about the expression of metallothioneins (MT) in different histological subtypes of this cancer and their impact on proliferation intensity in BCC. In this study, we examined MT-I/II expression by immunohistochemistry in 58 different histological subtypes of BCC (38 nodular, six adenoid, eight infiltrative, and six metatypic cases) and correlated its expression with tumor size and Ki-67 proliferation rate. Statistical analysis revealed no significant differences in the expression of studied markers in regard to the histological subtype. A positive correlation between MT and Ki-67 expression was observed for all the studied cases (r = 0.26; p = 0.049), but was even stronger in the metatypic subtype of BCC (r = 0.85; p = 0.033). MT and Ki-67 expression did not correlate with tumor size. In conclusion, it seems that metallothioneins may have an impact on the proliferation rate of BCC,but further studies are required to determine whether MT may be a risk factor of recurrences.

Topics: Adult; Aged; Aged, 80 and over; Carcinoma, Basal Cell; Cell Nucleus; Humans; Immunohistochemistry; Ki-67 Antigen; Metallothionein; Middle Aged; Skin Neoplasms; Young Adult

Ameloblastoma is a benign odontogenic tumor, exhibiting local invasiveness and high rate of recurrence. Metallothionein is a protein associated with tumorigenesis, serving as prognostic factor in different neoplasms. We are interested in mechanisms underlying ameloblastoma local invasiveness. Thus, we decided to analyze expression of metallothionein in this tumor.. An immunohistochemical evaluation of metallothionein in ameloblastoma was carried out. As control, we assessed expression of the same molecule in calcifying cystic odontogenic tumor (CCOT), a non-invasive odontogenic neoplasm with ameloblastomatous epithelium.. We studied 12 cases of solid/multicystic ameloblastomas. Metallothionein was observed in all samples. This molecule was observed in columnar cells in the periphery and in central polyhedral cells. CCOT (four cases) also showed the presence of metallothionein. Morphometry of stained areas showed that expression of metallothionein in ameloblastoma was significantly higher compared to CCOT (P < 0.0001).. This protein may have an impact on ameloblastoma behavior. Metallothionein would act as a zinc reservoir for important proteases related to ameloblastoma biology, such as MMPs. This protein could also display pro-mitotic and anti-apoptotic features in the tumor.

Topics: Ameloblastoma; Case-Control Studies; Gene Expression Regulation, Neoplastic; Humans; Metallothionein; Neoplasm Invasiveness; Odontogenic Tumors; Skin Neoplasms

DNA methylation plays a major role in cancer by silencing tumour suppressor genes. In melanoma, only a discrete number of methylated genes have been identified so far. After the treatment of melanoma cells with a DNA methyltransferase inhibitor and subsequent transcriptomic profiling, we had identified earlier a cohort of melanoma progression-associated genes regulated by methylation. Here, we identified which of these genes are directly methylated in melanoma cell lines and tissues. First, we examined 16 genes by bisulphite sequencing in the WM793 isogenic cell line model series. Five of these genes (CYBA, FABP5, MT1E, TSPY1 and TAC1) displayed increased methylation in several invasive cell lines compared with the parental WM793 cells, indicating their involvement in progression. Next, we analyzed several matched primary/metastatic tumours using methylation-specific PCR, which revealed that MT1E (one of the five genes assessed) was methylated in the largest proportion of tumours. Examination of a larger cohort of samples showed that 1 of 17 (6%) of the benign naevi, 16 of 43 (37%) primary tumours and 6 of 13 (46%) of the metastases displayed MT1E methylation. In addition, ectopic over-expression of MT1E mediated sensitization to cisplatin-induced apoptosis. Overall, these studies suggest that MT1E is a potential tumour suppressor gene, whose loss may promote resistance to apoptosis-inducing therapies.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cells, Cultured; Cisplatin; DNA Methylation; Drug Resistance, Neoplasm; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Genes, Tumor Suppressor; Humans; Melanoma; Metallothionein; Microarray Analysis; Skin Neoplasms; Transfection

Malignant melanoma is one of the most aggressive human neoplasms and its incidence is still increasing. Prognoses for melanoma patients are currently based on statistical parameters. For estimating the risk for a possible progression and for overall survival, Breslow tumour thickness and the invasion level (Clark level) are the most established markers for melanomas at the time of the primary diagnosis. In thicker melanomas (>1 mm) the additional information about the status of the sentinel lymph-node (SLN) might be helpful. Nevertheless new prognostic parameters are needed, that will allow us to formulate more precise prognoses for the individual cases. The metallo-thionein family is a class of intracellular low-molecular-weight, cysteine-rich proteins with a high affinity for heavy-metal ions. They are involved in many (patho-) physiological processes and presumably play an important role in the carcinogenesis. In the last decades overexpression of immunohistochemically labelled metallothioneins (MTs) on paraffin-embedded tissues turned out as a highly significant prognostic marker in different tumours. This review summarizes the results of those studies, in which MT-overexpression was able to show a very high significance for progression and survival in melanoma patients. In contrast to most other progression markers, MT-overexpression is independent from tumour-thickness, and is highly specific even in thin (low risk) melanoma patients. Nowadays, in high risk melanoma patients sentinel lymph-node (SLN-) biopsy is performed, a surgical technique with predictive value for progression, the benefit of this procedure for the individual overall survival still remains unclear. In a study comparing SLN and MT-overexpression the results corroborate the validity of MT-overexpression in primary melanoma as a useful additional prognostic marker, accuracy is comparable although to some degree supplementary to the results of SLN biopsy.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Child; Disease Progression; Female; Gene Expression Regulation, Neoplastic; Humans; Kaplan-Meier Estimate; Male; Melanoma; Metallothionein; Middle Aged; Neoplasm Staging; Predictive Value of Tests; Prognosis; Retrospective Studies; Sentinel Lymph Node Biopsy; Skin Neoplasms; Up-Regulation

The purpose of this study was to examine the effect of tricyclic antidepressant desipramine (DMI) on the growth inhibition and translocation of the glucocorticoid receptor (GR) from the cytoplasm to the nucleus in cancerous and noncancerous cell lines and the effect of DMI on GR-mediated transcription. Nontumorigenic, immortalized keratinocytes cell line (3PC), papilloma (MT1/2), and squamous cell carcinoma (Ca3/7) cell lines were initially used to study the cell growth inhibition by DMI. Although, the growth of all three cell lines was suppressed by DMI, it was more effective in Ca3/7 cells. Therefore, we next examined the effect of DMI on Ca3/7 cells, resistant to growth inhibition by the synthetic glucocorticoid fluocinolone acetonide (FA). DMI inhibited cell proliferation in a time-dependent manner. The translocation of GR was induced by FA alone, DMI alone, and combination of both agents. FA induced GR-mediated transcription in Ca3/7 cells transfected with a luciferase reporter gene under the control of glucocorticoid response element (GRE), but DMI alone did not affect GR-mediated transcription. However, DMI inhibited FA-induced, GR-mediated transcription when both agents were given together. Pretreatment with DMI followed by combination of DMI and FA decreased GR-mediated transcription more than pretreatment with FA. The expression of metallothionein-1 (Mt-1) gene, which is regulated by GR, was induced significantly by the combination of DMI and FA, and enhanced significantly by pretreatment with FA but not DMI. DMI is suggested to inhibit the growth of Ca3/7 cells and to affect GR-mediated transcription.

Topics: Animals; Anti-Inflammatory Agents; Antidepressive Agents, Tricyclic; Blotting, Western; Carcinoma, Squamous Cell; Cell Nucleus; Cell Transformation, Neoplastic; Cytoplasm; Desipramine; Fluocinolone Acetonide; Keratinocytes; Luciferases; Metallothionein; Mice; Papilloma; Receptors, Glucocorticoid; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Skin Neoplasms; Transcription, Genetic

Metallothioneins (MT) are ubiquitous, intracellular small proteins with high affinity for heavy metal ions. Immunohistochemical MT overexpression in paraffin-embedded tissues of patients with primary melanoma is associated with poor prognosis. While sentinel lymph node (SLN) biopsy is an established surgical technique for high-risk melanoma patients with predictive value for progression, the benefit of this procedure for the individual patient's overall survival remains unclear.. We examined the role of MT overexpression in comparison with SLN biopsy in melanoma patients as a prognostic marker for progression and survival. One hundred and fifty-eight (158) patients underwent SLN biopsy due to high-risk melanoma. Primary melanoma specimens were investigated by using a monoclonal antibody against MT on routinely fixed, paraffin-embedded tissues. The patients were followed up (median 37 months); the data of disease free survival and overall survival were calculated with a broad panel of statistical analyses.. Twenty-eight (18%) out of 158 recruited melanoma patients developed metastases, 17 (11%) patients died due to widespread disease. Kaplan-Meier curves gave significant disadvantages for the MT-positive as well as the SLN-positive group for progression and survival. In the Fisher's exact test and Pearson's chi(2)-test MT overexpression was highly significant for progression, whereas SLN biopsy failed significance. In univariate as well as multivariate Cox regression analysis MT overexpression proved an excellent marker for progression (P=0.007 and P=0.009), although the P-values for survival were not significant. In contrast, while in the univariate analysis SLN biopsy did not show significant results for progression it did for survival, and in the multivariate analysis reached a P-value < 0.05 for both measured endpoints.. Results corroborate the validity of MT overexpression in primary melanoma as a useful prognostic marker in melanoma patients. Accuracy is comparable and to some degree supplementary to the results of SLN biopsy.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Chi-Square Distribution; Child; Disease Progression; Female; Humans; Immunohistochemistry; Male; Melanoma; Metallothionein; Middle Aged; Predictive Value of Tests; Prognosis; Proportional Hazards Models; Sentinel Lymph Node Biopsy; Skin Neoplasms; Survival Analysis

Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are the most frequent skin cancer. Its pathogeny is linked to genotoxic effects of actinic radiation exposure, especially to ultraviolet wavelength. Metallothionein (MT) is a low-molecular weight protein with high affinity for heavy metal. Its intracellular function has been related to heavy metals and free-radical detoxification, although many studies linked MT to protective action against actinic mutagenesis. In other way, overexpression in malignant tumors has been related to worse prognosis. We aimed to evaluate MT immunohistochemical expression in skin cancer associated to actinic radiation. Twenty-six BCC cases, 20 SCC, and 6 normal skin fragments were investigated. Immunohistochemical assay were performed by streptavidin-biotin-peroxidase technique with standard monoclonal antibody (E9). In normal skin, immunostaining was observed in basal layer of the epithelium. In the epithelium adjacent to tumors, suprabasal layer was also intensely labeled. Mean MT immunostaining indices were 18.5+21.2% for BCC and 69.1+14.4% for SCC. This difference was statistically significant. Higher MT expression in SCC as compared with BCC suggests association with tumoral aggressiveness.

Topics: Aged; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Female; Humans; Immunohistochemistry; Male; Metallothionein; Skin Neoplasms; Ultraviolet Rays

Topics: Disease-Free Survival; Humans; Immunohistochemistry; Melanoma; Metallothionein; Prognosis; Prospective Studies; Skin Neoplasms

Metallothioneins (MT) are ubiquitous, intracellular small proteins with high affinity for heavy metal ions. In the last decades, it was shown that MT overexpression in a variety of cancers is associated with resistance to anticancer drugs and is combined with a poor prognosis. In this prospective study, we examined the role of MT overexpression in melanoma patients as a prognostic factor for progression and survival. Between 1993 and 2004, 3386 patients with primary cutaneous melanoma were investigated by using a monoclonal antibody against MT on routinely fixed, paraffin-embedded tissues. In all, 1270 patients could be followed up for further statistical analysis (Fisher's exact test, Mantel-Haenszel chi2 test, Kaplan-Meier curves). The MT data of disease-free interval and overall survival were compared univariately and multivariately in Cox regression analysis. Immunohistochemical overexpression of MT in tumour cells of patients with primary melanoma (310 of 1270; 24.4%) was associated with a higher risk for progression (117 of 167; 70.1%) and reduced survival (80 of 110; 72.7%) of the disease (P<0.0001). Similarly, Kaplan-Meier curves gave highly significant disadvantages for the MT-positive group. Univariate analysis (relative risk 7.4; 95% confidence interval (CI) 5.2-10.2; P<0.0001 for progression; relative risk 7.1; 95% CI 4.7-10.9; P<0.0001 for survival), as well as multivariate analysis with other prognostic markers resulted in MT overexpression as a highly significant and independent factor for prognosis in primary melanoma.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antibodies, Monoclonal; Biomarkers, Tumor; Child; Cohort Studies; Female; Gene Expression Profiling; Humans; Immunohistochemistry; Male; Melanoma; Metallothionein; Middle Aged; Multivariate Analysis; Prognosis; Prospective Studies; Skin Neoplasms; Survival Analysis; Up-Regulation

To clarify the physiological role(s) of metallothionein (MT) in carcinogenesis, we studied the susceptibility of MT-null mice to chemically mediated carcinogenesis in the 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced two-stage carcinogenesis model. The MT-null mice were subjected to a single topical application of DMBA (50 or 100 micro g/mouse) and, 1 week later, to promotion with TPA (10 micro g/mouse) twice a week for 20 weeks. At week 21, nearly all of the MT-null mice developed tumors in the skin, in contrast to only 10-40% of wild-type mice. No tumors were observed in MT-null or wild-type mice that were administered TPA alone. By using the PCR-restriction fragment length polymorphism and PCR-single strand conformation polymorphism methods, we found a transversion of A182 to T in codon 61 of c-Ha-ras in the papilloma tissue of MT-null mice and wild-type mice but failed to find any mutations in the c-Ki-ras and c-N-ras genes. In two-stage skin carcinogenesis induction by DMBA/TPA, p53 and p21(WAF1/Cip1) expression levels were found to be increased in MT-null mice compared with wild-type mice. As to an earlier change at the promotion stage triggered by TPA application, MT-null mice were found to have both hyperplasia of the epithelium and a marked degree of inflammation in the basal layer, indicating that the induced as well as endogenous MT acted as a protective factor against tumorigenesis. In conclusion, the present study has demonstrated that MT has antitumorigenic potential in both the initiation and promotion stages of the two-stage chemical skin carcinogenesis model.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Cell Division; Female; Genes, ras; Metallothionein; Mice; Mice, Inbred C57BL; Mutation; Polymerase Chain Reaction; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate

Metallothioneins (MTs) are ubiquitous proteins with high affinity for heavy metal ions, e.g. zinc, copper and cadmium. In the last decade it has been shown that MT overexpression in a variety of cancers is associated with resistance to anticancer drugs and radiotherapy, and with a poor prognosis.. To examine the role of MT overexpression in melanoma patients as a prognostic factor for progression and survival.. In a prospective cohort study 760 patients with primary cutaneous melanoma were investigated over 5 years (1993-98) by using a monoclonal antibody (E9) against MT on routinely fixed and paraffin-embedded tissues. In total, 520 patients were able to be followed up for progression of their disease or death due to melanoma and were included for statistical analysis (Fisher's exact test, Mantel-Haenszel chi2 test, Kaplan-Meier curves). MT data, progress-free interval and overall survival were compared univariately and multivariately with other prognostic factors, e.g. Breslow thickness, Clark level, ulceration, localization, age and gender (Cox regression analysis).. The immunohistochemical overexpression of MT in tumour cells (cut-off level > 10% of all tumour cells) in patients with primary melanoma (156 of 520; 30%) was associated with a higher risk for progression of the disease (33 of 45; 73%) and reduced survival (24 of 30; 80%) than MT-negative lesions [364 of 520 (70%), 12 of 45 (27%) and six of 30 (20%), respectively (P < 0.0001)]. Similarly, Kaplan-Meier tumour-free survival and overall survival curves for the comparison of MT-positive and MT-negative tumours gave highly significant advantages for the MT-negative group. In a univariate analysis (comparison with Breslow thickness: relative risk 2.9, 95% confidence interval, CI 1.46-5.76, P = 0.0023 for progression; relative risk 4.19, 95% CI 1.73-10.19, P = 0.0015 for survival), as well as in a multivariate analysis with other prognostic markers, MT overexpression turned out to be a highly significant and independent factor for prognosis in primary melanoma.. MT overexpression in primary melanoma is associated with an increased risk for disease progression. This marker is independent from Breslow thickness and helps to identify those thin melanomas (< 1.5 mm) that are at increased risk of progression. Moreover, the immunohistochemical staining of paraffin material is a cheap, easy and widely available technique to gain these results.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Disease Progression; Female; Humans; Immunohistochemistry; Male; Melanoma; Metallothionein; Middle Aged; Prognosis; Proportional Hazards Models; Prospective Studies; Risk Factors; Skin Neoplasms; Survival Analysis; Survival Rate

Recently, Zelger et al. found that metallothionein expression in melanoma is a useful prognostic indicator in white patients. In this study, we evaluated metallothionein expression in patients with melanoma as a prognostic indicator. We studied the tumors of 44 patients with cutaneous melanoma seen in our clinic from July 1988 to August 1998. Twenty-five neoplasms were metallothionein-positive, and 19 were metallothionein-negative. Only 9 (37.5%) of 24 cases of level I through III melanoma were positive for metallothionein, but 16 (80%) of 20 level IV and V cases were positive. Eight (40%) of 20 cases of "thin" melanoma (thickness: < or = 1.5 mm) were metallothionein-positive, and 17 (70.8%) of 24 cases of "thick" melanoma (thickness: > 1.5 mm) were metallothionein-positive. These results indicate a strong correlation of metallothionein expression with the level of invasion and tumor thickness in melanoma. The survival distribution function curve (Kaplan-Meier) for metallothionein expression showed a much better survival rate in the metallothionein-negative group than in the metallothionein-positive group.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Female; Follow-Up Studies; Humans; Immunohistochemistry; Infant; Male; Melanoma; Metallothionein; Middle Aged; Nevus, Pigmented; Skin Neoplasms; Survival Analysis; Survival Rate

Epidermal changes overlying dermatofibromas (DFs) have been described as ranging from psoriasiform simple hyperplasia to basaloid hyperplasia sometimes morphologically indistinguishable from superficial basal cell carcinoma (BCC). To characterize epidermal hyperplasia overlying DFs and to determine its association with the disease process, we examined 30 cases of DF showing hyperplastic epidermis. We used nine immunohistochemical markers associated with keratinocyte proliferation or differentiation. In DFs, the dermal metallothionein (MT) expression and immunophenotypic changes with regard to epidermal differentiation varied depending on the stage of lesional evolution of the DFs. Immunostaining for epidermal growth factor receptor (EGFR), MT, and keratin 6 (K6) increased in simple hyperplastic epidermis (SHE) overlying DFs (n = 11), whereas it gradually diminished in basaloid hyperplastic epidermis (BHE) overlying DFs (n = 19). In SHE, there was a significant increase in K14 expression. Among 19 BHE cases, 12 showed premature expression of involucrin and delayed appearance of K1 along with aberrant expression of K14. Conversely, the remaining 7 BHE cases showed a pattern of involucrin and K1 similar to that of normal skin coinciding with decreased or absent dermal MT expression. Loricrin and filaggrin expression in all DFs was the same as that of normal skin. Based on the sparse positivity of Ki-67 in the hyperplastic epidermis overlying DFs, we found that the biologic ability of BHE and SHE was not apparent in the hyperproliferative state observed in psoriasis and BCC. These results suggest that the dermal fibrohistiocytic process may trigger the induction of SHE overlying DFs by an unknown mechanism and then mediate both the abnormal keratinocyte differentiation and the transformation of SHE to BHE through the evolution of the dermal lesions.

Topics: Biomarkers; Carcinoma, Basal Cell; Cell Differentiation; Cell Division; Epidermis; ErbB Receptors; Filaggrin Proteins; Histiocytoma, Benign Fibrous; Humans; Hyperplasia; Immunoenzyme Techniques; Keratinocytes; Keratins; Metallothionein; Precancerous Conditions; Psoriasis; Skin Neoplasms

We analyzed 53 specimens from primary squamous cell carcinomas of the skin for the expression of collagenase IV, cathepsin D and metallothionein by means of immunohistochemistry along with histological data. We compared tumors that metastasized (30) with tumors that did not (23) during a follow-up period of at least 5 years. The expression of the two proteolytic enzymes cathepsin D and collagenase IV was also assessed at the invading front of the tumors. Statistical analyses revealed significant differences for the overall expression of cathepsin D (P < 0.05), expression of cathepsin at the invading front (P < 0.05) and the tumor thickness (P < 0.01). The results showed that cathepsin D may be a prognostic factor for squamous cell carcinomas of the skin. We then combined the results of parameters with statistically significant differences by multiplication. The prognostic value of such a combined risk-factor score showed higher confidence than any of the single parameters alone: a sensitivity of 63.3%, a specificity of 87.0% and an efficiency of 73.6%. This kind of combined risk-factor score might be used to more accurately detect patients at high risk of metastasis.

Topics: Aged; Carcinoma, Squamous Cell; Cathepsin D; Female; Humans; Immunohistochemistry; Male; Matrix Metalloproteinase 2; Metallothionein; Predictive Value of Tests; Prognosis; Skin Neoplasms

Based on a series of 25 cases, we define and characterize combined dermatofibroma, a tumour comprising two or more variant patterns of dermatofibroma in a single lesion.. Dermatofibroma may present with a wide variety of architectural, cellular or stromal peculiarities. Architectural peculiarities include deep penetration, atrophy, collarette formation, fascicular to plexiform architecture, massive haemorrhage, prominent haemangiopericytoma-like vascularity and palisading; cellular peculiarities the presence of epithelioid cells, clear cells, granular cells, prominent myofibroblastic differentiation and atypical giant cells ('monster cells'); or stromal peculiarities such as prominent sclerosis, mucin, haemosiderin and cholesterotic deposits. In combined dermatofibromas two or more of these features are seen in complex or inhomogenous combination such as the silhouette of a deep penetrating dermatofibroma with an 'ordinary' storiform pattern in the upper and granular cell differentiation in the lower part of the lesion; or a dermatofibroma with ordinary features in the upper, prominent sclerosis in the middle and clear cells in the lower portion of the lesion; or the characteristic epidermal collarette and cells of epithelial cell histiocytoma with a plexiform ('neurothekeoma-like') architecture surrounded by a myxoid stroma with spindle-shaped to stellate cells. Clinically, these lesions preferentially occur on the lower extremities of young to middle-aged females, frequently with the diagnosis of a fibrohistiocytic lesion. Apart from one recurrence follow-up was uneventful in all other cases. Immunohistochemically, lesions are consistently positive with KiM1p, variably positive for factor XIIIa, smooth muscle specific actin and with KP1 (CD68), NK1C3 and E9.. Recognition of combined dermatofibroma allows the histopathologist to apply a confident benign label to unusual lesions which might otherwise elude diagnosis, or tempt description of 'new' entities and to avoid a misdiagnosis of malignancy.

Topics: Actins; Adult; Aged; Aged, 80 and over; Antigens, CD; Antigens, Differentiation, Myelomonocytic; CD57 Antigens; Child; Diagnosis, Differential; Female; Histiocytoma, Benign Fibrous; Humans; Immunohistochemistry; Infant; Male; Metallothionein; Middle Aged; Muscle, Smooth; Skin Neoplasms; Transglutaminases

We examined the basis of the all or none difference in inducing melanocytic tumor development among three transgenic mouse lines (304, 192 and 242) to which the same promoter-enhancer (metallothionein-I) and oncogene (ret) were introduced. We initially demonstrated that both skin melanosis and Ret protein expression in skin, thymus and brain first became detectable before or immediately after birth in the mice of the tumor developing lines (304 and 192), whereas they became detectable a few days after birth in the mice of the non-tumor developing line (242) by Western blotting and immunohistochemical analysis. Interestingly, the Ret protein expression in skin developed rapidly after birth as a burst with peak levels on 0.5-1.5 day newborns of lines 304 and 192 and on 7.0-7.5 day-old mice of line 242. The levels of autophosphorylation of Ret kinase in skin were, however, invariable among these three transgenic mouse lines. The mice of line 242, but not those of lines 192 and 304, responded to Ret protein immunization by increased antigen-dependent lymphocyte proliferation and T-cell-mediated tumor growth suppression in vitro. Furthermore, ret-transgenic mice of line 242, but not line 304, rejected the subcutaneously transplanted tumors that had originally developed in a mouse of line 304. These results suggest that whether oncogene product-specific-tolerance is established or not to antitumor immunity may be decided by the dynamics of ret oncogene expression before and after delivery and this is the primary factor determining development or non-development of melanoma.

Topics: Animals; Drosophila Proteins; Genetic Linkage; Humans; Melanocytes; Metallothionein; Mice; Mice, Transgenic; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-ret; Receptor Protein-Tyrosine Kinases; Skin Neoplasms

Reactive oxygen species formation is strongly suspected to play a role in multistep carcinogenesis, notably in tumor promotion. The tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) induces peroxide production, oxidative damage to DNA and inflammation in mouse skin. TPA is also known to cause a decrease in the activity of several antioxidant enzymes including glutathione peroxidases (GPx). The observation that several anti-oxidants can inhibit TPA-mediated tumor promotion suggests that a decline in GPx activity could contribute to tumor promotion. We report here the effects of TPA on GPx activity in the skin of transgenic GPx mice that contain human GPx-1 transgenes under the regulation of a metallothionein IIA promoter. As expected, no significant difference in basal level of skin GPx activity was detected in the 3 lines of tg-MT-GPx mice investigated compared with non-transgenic controls. A single topical application of TPA induced gradually, over 20 hr, a small but detectable increase in GPx mRNA and protein levels in skin of non-transgenic mice and a contrasting decrease in both selenium-dependent and selenium-independent GPx activity. The extent of GPx induction was more pronounced in transgenic mice, and in contrast with non-transgenic mice, no significant loss of GPx activity was observed in the TPA-treated skin of these mice. Transgenic mice may, therefore, offer a novel model suitable to assess the role of GPx-1 in skin carcinogenesis, without the potential disadvantage of abnormally high levels of GPx activity produced constitutively in other transgenic models.

Topics: Animals; Carcinogens; Enzyme Induction; Female; Glutathione Peroxidase; Humans; Immunity, Innate; Metallothionein; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Transgenic; Promoter Regions, Genetic; Reactive Oxygen Species; Recombinant Fusion Proteins; RNA, Messenger; Selenium; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate

We recently established a metallothionein-I(MT)/RET transgenic mouse line in which skin melanosis, benign melanocytic tumor and malignant melanoma develop stepwise. Malignant melanoma cells but not benign melanocytic tumor cells had metastatic ability in transgenic mice. In the present study, we investigated the expression of several matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs), including MMP-1, MMP-2, MMP-3, MMP-7, MMP-9, MT1-MMP, TIMP-1 and TIMP-2, in these tumors. Western and northern blot analyses revealed that malignant transformation of melanocytic tumors developed in MT/RET transgenic mice accompanied with upregulation of MMP-9 and downregulation of TIMP-2. Expression of other MMP and TIMP genes examined was very low or undetectable in both benign and malignant tumors. Since activation of MMP-9 in malignant tumors was detected by gelatin zymography, these results suggest that imbalance of expression of the MMP-9 and TIMP-2 genes might be associated with metastatic ability of melanoma cells developed in MT/RET transgenic mice.

Topics: Animals; Cell Transformation, Neoplastic; Collagenases; Drosophila Proteins; Gelatinases; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; In Situ Hybridization; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Melanocytes; Melanoma; Metalloendopeptidases; Metallothionein; Mice; Mice, Transgenic; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-ret; Proto-Oncogenes; Receptor Protein-Tyrosine Kinases; Recombinant Proteins; Reverse Transcriptase Polymerase Chain Reaction; Skin Neoplasms

To investigate a possible involvement of metallothionein (MT) in chemical carcinogenesis, MT-I and MT-II gene-deficient [MT (-/-)] transgenic mice and wild-type [MT (+/+)] control mice were topically applied at a single dose of 100, 250, 500, or 1000 microg of 7,12-dimethylbenz[a]anthracene (DMBA) on the dorsal skin and thereafter compared. After 14 weeks of DMBA treatment, the skin tumor occurred in MT (-/-) mice only and in a dose-dependent manner, whereas no change was observed in MT (+/+) mouse skin given the same DMBA treatment. The tumor cells showed proliferative activity, as shown by proliferative cell nuclear antigen staining. These results demonstrate that MT acts as an endogenous defensive factor against DMBA-induced skin tumorigenesis.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinogens; Dose-Response Relationship, Drug; Metallothionein; Mice; Mice, Inbred C57BL; Neoplasms, Experimental; Proliferating Cell Nuclear Antigen; Skin Neoplasms

We report here on a novel metallothionein-I (MT)/ret transgenic mouse line in which skin melanosis, benign melanocytic tumor and malignant melanoma metastasizing to distant organs develop stepwise. The process of tumor development and its malignant transformation in this line may resemble that of the human giant congenital melanocytic nevus that is present at birth and that frequently gives rise to malignant melanoma during aging. We observed an increase in the expression level and activity of the ret transgene during the disease progression. That increase in transgene expression accompanied an activation of mitogen-activated protein kinases (MAPKs) and c-Jun as well as matrix metalloproteinases. These results suggest that progressive dysregulation of the expression level of the ret transgene might play a crucial role in the malignant transformation of melanocytic tumors developed in the MT/ret transgenic mouse line.

Topics: Animals; Calcium-Calmodulin-Dependent Protein Kinases; Disease Models, Animal; Female; Humans; Male; Melanoma, Experimental; Metallothionein; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mitogen-Activated Protein Kinase 1; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-jun; Skin Neoplasms

Basaloid proliferations overlying dermatofibromas which morphologically resemble superficial basal cell carcinomas have been interpreted as both reactive/regressive and frankly malignant. Metallothioneins (MTs) are low-molecular-weight proteins with a selective binding affinity for heavy metal ions. MTs has been proposed to represent a biological marker of carcinogenesis and, in a variety of human tumours, a correlation between immunohistochemically overexpression of MT and aggressive clinical behaviour has been shown. In order to clarify the nature of basaloid proliferations overlying dermatofibromas, we examined, immunohistochemically, 10 dermatofibromas with overlying simple hyperplasia, 16 dermatofibromas with overlying basaloid proliferation, and 35 basal cell carcinomas, for expression of MT. In normal epidermis, the basal keratinocytes showed cytoplasmatic MT immunoreactivity. The staining intensity was stronger in the basal cells of the rete ridges, an observation which is in accordance with the high proportion of S-phase cells in this area. Simple hyperplasia showed the same MT expression pattern as normal epidermis. Basaloid proliferations stained like superficial and nodular basal cell carcinomas. Of nodular basal cell carcinomas, 92% (12 of 13) showed decreased/absent MT immunoreactivity, while 86% (six of seven) of infiltrating/morphoea-like basal cell carcinomas showed overexpression of MT (P = 0.001, Fisher's exact test). The results demonstrate that MT overexpression in basal cell carcinomas is correlated with infiltrative growth pattern. The similar expression of MT in basaloid proliferations and 'non-infiltrating' basal cell carcinomas suggests that these lesions share a common change in metabolism and/or differentiation.

Topics: Biomarkers, Tumor; Carcinoma, Basal Cell; Cell Division; Epidermis; Histiocytoma, Benign Fibrous; Humans; Hyperplasia; Immunoenzyme Techniques; Keratinocytes; Metallothionein; Skin Neoplasms

Because metallothionein (MT) is elevated and may be protective in UV-irradiated skin, we have studied the effects of UV and other agents on MT transcription using the sheep MT 1A promoter, linked to the beta-galactosidase gene and stably transfected into human cell lines. beta-galactosidase reporter activity was inducible by adding Zn2+ ions to the medium (100 microM for 2-4 h). Two differentiating agents, butyric acid and azelaic bishydroxamic acid (ABHA), significantly increased the response to Zn2+ in a melanoma cell line (MM96L-gal). UVB (280-315 nm) had two distinct, time-dependent effects. During the first 4 h after irradiation, high doses of UVB inhibited induction by Zn2+, an effect that was made more acute by simultaneous exposure to the differentiating agents. These changes in reporter activity were not due to alterations in Zn2+ transport into the cell. The UVB-depressed MT response subsequently recovered and by 24 h was double the control, yet remained sensitive to ABHA. Reporter activity in transfected HeLa cells differed from that in MM96L, being depressed 4 and 24 h after UVB and insensitive to ABHA at both times. Galactosidase reporter activity driven by non-MT promoters was not affected by these treatments. Dependence of MT transcriptional activity on UV-related DNA damage could be inferred because equitoxic UVC (254 nm) affected the response to Zn2+ in a similar fashion, whereas UVA, cisplatin and a methylating agent had no effect. The MT response was partly dependent on the PKC signal transduction pathway because it was inhibited by phorbol ester in HeLa, and by bisindolyl maleimide in HeLa and MM96L. The biphasic MT transcriptional response may model a signal transduction pathway that gives an early, depressed response to acute UV damage, with exacerbation by concurrent differentiation stimuli, but switches to a positive, cell-specific and potentially protective response at later times.

Topics: Animals; Cell Differentiation; HeLa Cells; Humans; Melanoma; Metallothionein; Promoter Regions, Genetic; Sheep; Skin Neoplasms; Tumor Cells, Cultured; Ultraviolet Rays

Topics: Adult; Aged; Child; Child, Preschool; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Infant; Male; Melanoma; Metallothionein; Middle Aged; Nevus, Epithelioid and Spindle Cell; Skin Neoplasms

Dermal atrophy of more than 50% of the locoregional dermis may be the predominant histopathological feature in dermatofibroma and dermatofibrosarcoma protuberans. This may cause diagnostic difficulties. In the present study 26 cases of atrophic dermatofibroma were compared with three cases of atrophic dermatofibrosarcoma protuberans. Clinically, both conditions mostly occurred on the (upper) trunk of females. While atrophic dermatofibroma usually presented as a reddish, umbilicated lesion (0.5-1cm), often suspected to be a basal cell carcinoma, atrophic dermatofibrosarcoma protuberans showed irregularly arranged tan-brown plaques (3-6 cm). Histologically, atrophic dermatofibroma showed a regular silhouette with a smooth nodular (9/26) or scalloped lower margin with an intervening lace-like pattern of superficial fatty tissue infiltration (17/26) and variable sclerosis: atrophic dermatofibrosarcoma protuberans showed a deep, irregular infiltration of fatty tissue in a lacelike/honeycomb and/ or multilayered pattern, but no sclerosis. Immunohistochemically, atrophic dermatofibroma was mostly negative with QBEnd 10 (CD34;24/26), variably positive for factor XIIIa (20/26) and metallothionein (11/26). Labelling for factor XIIIa and metallothionein was usually seen in 'early' (metabolically active) lesions, while 'late' sclerotic ones were negative. In contrast to atrophic dermatofibroma all three atrophic dermatofibrosarcoma protuberans showed a consistently uniform profile: CD34 positive, factor XIIIa and metallothionein negative. Our study delineates atrophic dermatofibroma and atrophic dermatofibrosarcoma protuberans as distinct entities clearly distinguishable from each other by clinicopathologic criteria.

Topics: Adult; Aged; Antigens, CD; Antigens, CD34; Atrophy; Child; Dermatofibrosarcoma; Diagnosis, Differential; Female; Histiocytoma, Benign Fibrous; Humans; Immunohistochemistry; Male; Metallothionein; Middle Aged; Skin Neoplasms; Transglutaminases

Topics: Gene Expression Regulation, Neoplastic; Genes, ras; Humans; Immunoenzyme Techniques; Melanoma; Metallothionein; Skin Neoplasms

Transgenic mice expressing v-jun under the control of the H-2K promoter develop dermal fibrosarcomas and rhabdomyosarcomas via a multistep process following wounding. To assess the relative roles that wounding and the H-2K promoter play in this process, we compared the phenotype of H-2K-v-jun mice with that of animals expressing v-jun under the control of the metallothionein I (MTI) promoter. MT-v-jun animals also develop wound-induced neoplasms by a multistage process. Both early and late features of tumorigenesis in MT-v-jun mice are different, however, from what is observed in H-2K-v-jun animals. First, the acute hyperplastic response that is characteristic of H-2K-v-jun granulation tissue is not observed in MT-v-jun wounds. Second, the myogenic components that are readily detected in the majority of late stage H-2K neoplasms are never observed in their MT counterparts. Moreover, analysis of wound tumours arising in animals expressing both MT-v-jun and H-2K-v-jun reveals that the two transgenes are not expressed in identical malignant cell populations. These results imply that mesenchymal granulation tissue is heterogeneous in composition and that the different cellular phenotypes of MT-v-jun and H-2K-v-jun malignancies result from oncogenic activation of wound-derived cells which differ in their differentiation potential. Thus, whereas the wounding component of multistage tumorigenesis is attributable to the action of v-jun, the transcriptional regulatory elements which drive its expression determine the nature of the target cells which give rise to wound-induced neoplasms.

Topics: Animals; Gene Expression; Genes, jun; H-2 Antigens; Metallothionein; Mice; Mice, Transgenic; Muscles; Sarcoma, Experimental; Skin Neoplasms; Tumor Cells, Cultured; Wounds and Injuries

Metallothioneins are ubiquitous proteins with a high affinity for heavy metal ions, e.g. zinc, copper and cadmium. Experimentally, metallothionein over-expression in cell lines derived from a variety of cancers has been associated with resistance to anticancer drugs and irradiation therapy. Using a monoclonal antibody (E9) to metallothionein we investigated immunoreactive expression in routinely fixed and paraffin-embedded tissue from 63 cases of malignant melanoma and 13 secondary deposits. Whereas a variety of cells in normal skin showed metallothionein expression, all forms of benign naevi studied were uniformly negative. In contrast 13/30 'thin' (< or = 1.5 mm; 0.7 +/- 0.4), 25/29 'thick' malignant melanoma (> 1.5 mm; 5.5 +/- 3.9) and 12/13 metastases were positive. Six patients with thin and 19 with thick melanoma with metallothionein expression died during a mean observation period of 6.4 +/- 1.8 and 3.6 +/- 2.5 years, respectively, their survival distribution function analyses giving statistically significant results for both the vertical tumour thickness (P < 0.0001) and metallothionein expression (P < 0.0001). These immunohistochemical results, based on routinely processed paraffin-embedded tissue, suggest that metallothionein expression in malignant melanoma is significantly associated with progressive disease and might therefore be a useful prognostic indicator.

Topics: Adult; Aged; Aged, 80 and over; Female; Humans; Immunohistochemistry; Male; Melanoma; Metallothionein; Middle Aged; Neoplasm Proteins; Nevus; Skin Neoplasms; Survival Analysis

The inhibitory effect of retinoic acid (RA) on 12-O-tetradecanoylphorbol-13-acetate- (TPA) induced mouse skin tumors was studied. Two subpopulations of tumors, small (< 2 mm) and large (> or = 2 mm) appeared after 12 weeks of cutaneous promotion by TPA (10 nmol), following initiation by application of 2 x 100 nmol of 7,12-dimethylbenz[a]anthracene (DMBA) to the skin. RA in the doses of 17 and 34 nmol, prior to each TPA treatment inhibited (P < 0.05) the formation of small tumors at 12 weeks of promotion. However, RA in either dose did not inhibit the formation of large (> or = 2 mm) tumors. Ten weeks following withdrawal of all treatments, the number of large tumors persisted in a significantly (P < 0.05) higher number as compared to small tumors in all groups. Our results provide evidence for the existence of tumor subpopulations with a differential response to RA. In addition, elevated levels of metallothionein (MT) expression were demonstrated in papillomas induced by TPA, 72 h after the last TPA treatment. Comparing papillomas treated with RA prior to each TPA treatment and papillomas treated with TPA only, demonstrated that the elevated MT expression in papillomas was unaffected by RA. This indicated that RA did not affect the expression of a protein that showed elevated level in TPA-induced papillomas.

Topics: Animals; Female; Metallothionein; Mice; Mice, Inbred Strains; Papilloma; Skin Neoplasms; Tetradecanoylphorbol Acetate; Tretinoin

A single topical treatment of mouse skin with the potent tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) results in transient inductions of a variety of genes. Based on the time courses of their inductions, these genes can be classified into two main groups: "early" response genes whose mRNA expression reaches a maximum 0.5-2 h after TPA treatment and "secondary" response genes whose mRNA expression is maximal 4 h or more after treatment. The nuclear oncogenes c-fos, c-myc, and c-jun belong to the early response group, whereas the metallothionein, osteopontin, and urokinase genes belong to the secondary response group. The steady-state expressions of these early and secondary response genes are all very low in normal skin, except that of c-jun, which is relatively high. Steady-state levels of expression and inducibility of these genes by TPA were not altered in initiated skin or in apparently normal skin during tumor promotion. We examined the expressions of these genes in papillomas and carcinomas produced by two-stage (initiator-promoter) and three-stage (initiator-promoter-initiator) protocols in mouse skin. Steady-state expression of the early responding nuclear oncogenes in papillomas and carcinomas was found to remain at the same low level as in normal skin. However, all the secondary responding genes were found to be expressed constitutively at high levels in these tumors. Elevated expressions of the genes for transforming growth factor alpha and beta were also observed in papillomas and to varying extents in carcinomas. These observations suggest that the regulatory machinery for transcription by the protein kinase C-mediated pathway through nuclear oncogenes is altered during the processes of tumor promotion and progression. The genes whose expression is elevated may be associated directly or indirectly with tumor promotion and progression.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Blotting, Northern; Carcinogens; Carcinoma; Female; Gene Expression; Metallothionein; Methylnitronitrosoguanidine; Mice; Mice, Inbred Strains; Osteopontin; Papilloma; Proto-Oncogene Proteins; RNA, Messenger; Sialoglycoproteins; Skin; Skin Neoplasms; Skin Physiological Phenomena; Tetradecanoylphorbol Acetate; Transforming Growth Factors; Tubulin; Urokinase-Type Plasminogen Activator

A single topical application of 12-O-tetradecanoylphorbol-13-acetate (TPA) was found to induce mRNA of a metallothionein (MT) gene or genes in the skin of Sencar mice, and papillomas produced by repeated applications of TPA were shown to have elevated levels of MT mRNA. Induction of MT mRNA was maximal 4-8 h after application of TPA and returned to the control level 24 h later. A dose-dependent increase of MT mRNA was observed with doses of TPA of 1-5 micrograms. Of the other promoters tested, phorbol-12, 13-didecanoate, mezerein, and the ionophore A23187 also induced MT mRNA, but 4-O-methyl-TPA and benzoyl peroxide did not. Phorbol and 4 alpha-phorbol-12,13-didecanoate, which are not promoters, also did not induce MT mRNA. Retinoic acid and 1 alpha, 25-dihydroxyvitamin D3, inhibitors of tumor promotion, did not induce MT mRNA themselves or inhibit the induction of MT mRNA by TPA. In C57BL/6 promotion-resistant mice, TPA caused only slight induction of MT mRNA. These data suggest a correlation between induction of MT mRNA and epidermal hyperplasia. The constitutive elevation of MT mRNA levels in papillomas may be due to the loss, during the process of tumor promotion, of some mechanism regulating MT gene expression.

Topics: Administration, Topical; Animals; Carcinogens; Cholecalciferol; Female; Gene Expression Regulation; Metallothionein; Mice; Mice, Inbred C57BL; Papilloma; RNA, Messenger; Skin Neoplasms; Tetradecanoylphorbol Acetate; Transcription, Genetic; Tretinoin

The ability of zinc acetate to modify the carcinogenic effects of CdCl2 in male Wistar [Crl:(WI)BR] rats was studied over a 2-year period. Groups of rats received a single s.c. injection of Cd (30.0 mumol/kg) in the dorsal thoracic midline or i.m. in the right thigh at time 0. Zinc was given in three separate s.c. doses of 0.1, 0.3, or 1.0 mmol/kg (at -6, 0, and +18 h relative to cadmium) in the lumbosacral area or p.o. at 100 ppm in the drinking water (-2 to +100 weeks). Cadmium treatments (s.c.) resulted in the appearance of tumors at the injection site and in the testes. The incidence of s.c. injection site tumors (mostly mixed sarcomas) was markedly reduced by high dose (1.0 mmol/kg) s.c. zinc (50% reduction) and was almost abolished by p.o. zinc (92% reduction). Testicular tumors (mostly Leydig cell adenomas) induced by s.c. cadmium were reduced in a dose-related fashion by zinc and were found to be highly dependent on the ability of zinc to prevent the chronic degenerative effects of cadmium in the testes. Oral zinc had no effect on s.c. cadmium-induced testicular tumors, while i.m. cadmium alone did not induce these tumors. In rats in which s.c. cadmium-induced testicular tumors and chronic degenerative effects were prevented by zinc (1.0 mmol/kg, s.c.), a marked elevation in prostatic tumors (exclusively adenomas) occurred (control, 9.6%; cadmium plus high zinc 29.6%). Cadmium given i.m., which did not result in testicular tumors or degeneration, also induced an elevated incidence (42.3%) of prostatic tumors, again indicating a dependence on testicular function. Prostatic tumor incidence was also significantly elevated (25.0%) in rats receiving 1.0 mmol/kg zinc, s.c., in combination with i.m. cadmium. These results indicate that zinc inhibition of cadmium carcinogenesis is a complex phenomenon, depending not only on dose and route but also on the target site in question.

Topics: Animals; Cadmium; Dose-Response Relationship, Drug; Injections, Subcutaneous; Male; Metallothionein; Prostatic Neoplasms; Rats; Rats, Inbred Strains; Sarcoma, Experimental; Skin Neoplasms; Testicular Neoplasms; Zinc