Study in effects of 1, 25-dihydroxyvitamin D₃ on apoptosis and autophagy of colon cancer cells and its mechanism

  Objective  To observe the effects of 1, 25 dihydroxyvitamin D₃1, 25-(OH)₂D₃ on apoptosis and autophagy of human colon cancer HCT116 cells and explore its mechanism.

  Methods  HCT-116 cells were cultured in vitro and divided into control group, low-dose group, medium-dose group, high-dose group and combined grouphigh-dose 1, 25-(OH)₂D₃ combined with adenosine monophosphate activated protein kinase (AMPK) inhibitor. Apoptosis and autophagy were observed and compared in each group.

  Results  The degrees of apoptosis and autophagy, the expression levels of cleaved Caspase 3, cleaved Caspase 8, LC3Ⅱ/LC3Ⅰ, Beclin-1 and p-AMPK proteins in HCT-116 cells in low-dose group, medium-dose group and high-dose group were significantly higher, and the expression level of p-mTOR protein was significantly lower compared with those in the control group (P < 0.05). The degrees of apoptosis and autophagy, the expression levels of cleaved Caspase 3, cleaved Caspase 8, LC3Ⅱ/LC3Ⅰ, Beclin-1 and p-AMPK proteins in HCT-116 cells in the combined group were significantly lower, while the expression level of p-mTOR protein was significantly higher compared with those in the high-dose group (P < 0.05).

  Conclusion  1, 25-(OH)₂D₃ can enhance apoptosis and autophagy of colon cancer cells by regulating AMPK/mTOR signaling pathway thereby playing anti-tumor roles.