Effects of demethoxycurcumin on the viability and apoptosis of skin cancer cells

The present study investigated the effects and mechanisms of demethoxycurcumin (DMC) on a human skin squamous cell carcinoma cell line, A431, and a human keratinocyte cell line, HaCaT. A431 and HaCaT cells were cultured in vitro. The effects of DMC treatment on cell viability were analyzed using the Cell Counting kit-8 (CCK-8) assay; cell cycle distribution was analyzed by flow cytometry; apoptosis was assessed by flow cytometry and Hoechst 33258 staining; and the protein expression levels of cytochrome c, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (BAX), caspase-9 and caspase-3 were evaluated by western blotting. CCK-8 assay results demonstrated that DMC treatment significantly inhibited viability of A431 and HaCaT cells in a dose-dependent manner. Flow cytometric analysis confirmed that DMC treatment induced apoptosis in a dose-dependent manner, and significantly increased the proportion of cells in G2/M phase. Western blot analysis indicated that the protein expression levels of Bcl-2 were decreased, whereas the expression levels of BAX, caspase-9, caspase-3 and cytochrome c were increased following DMC treatment compared with in untreated cells. In conclusion, DMC treatment significantly inhibited viability of A431 and HaCaT cells, and induced cell cycle arrest in G2/M phase. The present study indicated that DMC may induce apoptosis of skin cancer cells through a caspase-dependent pathway.