Rapamycin induces autophagy in the melanoma cell line M14 via regulation of the expression levels of Bcl-2 and Bax.

Cancer therapy with rapamycin has been successfully implemented for kidney cancer, glioblastoma and prostate cancer. However, there are few studies concerning the effects of rapamycin on the treatment of human melanoma. In this study, we investigated whether rapamycin may be a promising strategy for the effective treatment of melanoma and explored the possible mechanism for this by culturing M14 cells in vitro and treating with rapamycin at three concentrations (10, 50 or 100 nmol/l). MDC and LC3B staining, western blot analysis, flow cytometry and transmission electron microscopy were employed. We revealed that rapamycin induced autophagy and inhibited the proliferation of M14 cells in a concentration-dependent manner, Furthermore, western blot analysis revealed an upregulated expression of Bcl-2 and downregulated expression of Bax in M14 cells. In conclusion, rapamycin induced autophagy and inhibited the growth of M14 cells. The mechanism may involve regulation of the expression of Bcl-2 family proteins. Rapamycin appears to be a promising strategy for the effective treatment of melanoma.