[Apoptosis induced by curcumin and its effect on c-myc and caspase-3 expressions in human melanoma A375 cell line].

Objective: To investigate the effect of curcumin on cell apoptosis and c-myc and caspase-3 expressions in human melanoma A375 cell line.

Methods: A375 cells were exposed to curcumin treatment and growth inhibition of the cells was examined by MTT assay. Annexin V/propidium iodide double staining and DNA fragmentation analysis were employed for assay of the cell apoptosis and morphological changes of the cells were observed with inverted microscopy and transmission electron microscopy, respectively. In situ hybridization and SABC immunohistochemistry were performed for detection of the expressions of c-Myc and caspase-3 in the A375 cells.

Results: Curcumin inhibited the growth of A375 cells in both time- and concentration-dependent manners. After treatment with 30 micromol/L curcumin for 48 h, apoptotic morphological changes were observed in the cells and an oligonucleosomal DNA ladder was clearly visualized in DNA fragmentation analysis. The apoptotic rates of the cells treated with curcumin at the concentration above 20 micromol/L were significantly higher than that of the control cells. c-myc expression level was decreased whereas caspase-3 expression increased with the increase in curcumin concentrations.

Conclusion: Curcumin can inhibit the proliferation and induce apoptosis of A375 cells in vitro, and the genes encoding c-myc and caspase-3 may play a role in the process.