Expression of the c-Met Proteins in Malignant Skin Cancers

ABSTRACT

BACKGROUND: The expression of c-Met is substantially elevated in most malignant human cancers. We therefore searched for c-Met expression and compared the expression level among malignant skin cancers. OBJECTIVE: The aim of this study was to determine the c-Met expression pattern and the protein expression level in selected malignant cutaneous tumors. METHODS: G361 cells (malignant melanoma cell line) and A431 cells (squamous cell carcinoma cell line) were cultured and analyzed, using immunoprecipitation and Western blot analysis, for expression of c-Met. Additionally, 16 separate specimens of malignant melanomas (MMs), 16 squamous cell carcinomas (SCCs), 16 basal cell carcinomas (BCCs) and 16 normal tissues were analyzed for the expression of c-Met using immunohistochemical studies. RESULTS: Based on cultured cell immunoprecipitation and Western blot analysis, both A431 cells and G361 cells expressed c-Met, however, c-Met was expressed substantially more in G361 cells. Immunohistochemical examination of c-Met showed that it was over-expressed in all malignant skin cancers. In addition, c-Met expression was more increased in MM compared to other cancers. CONCLUSION: In our study, c-Met is involved in malignant skin cancer development and the level of its expression is thought to be related to the degree of malignancy in melanoma cancers.