Expression of the c-Met Proteins in Malignant Skin Cancers.

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.