Insulin-Like Growth Factor-1 Modulates Polycomb Cbx8 Expression and Inhibits Colon Cancer Cell Apoptosis

Colon cancer is one of the leading causes of death in human beings. The pathogenesis of colon cancer is unclear. Recent reports indicate that Chromobox protein homolog 8 (Cbx8) and insulin-like growth factor-1 (IGF1) are associated with the pathogenesis of cancer. This study aims to investigate the role of Cbx8 and IGF1 in facilitating colon cancer cell proliferation. In this study, human colon cancer cell line, HCT116 cells, was cultured using an in vitro study model. The expression of Cbx8 and IGF1R (IGF1 receptor) in HCT116 cells was observed with approaches of real-time RT-PCR, Western blotting, gene silencing, and gene overexpression. The results showed that HCT116 cells express both Cbx8 and IGF1R. Exposure of HCT116 cells to IGF1 increased the expression of Cbx8. Knockdown of Cbx8 induced HCT116 cell apoptosis. Overexpression of Cbx8 induced HCT116 cell proliferation. We conclude that IGF1 can promote the colon cancer cell line, HCT116 cell, proliferation via promoting Cbx8 expression.