Genistein inhibits human colorectal cancer growth and suppresses miR-95, Akt and SGK1.

BACKGROUND Genistein, a major isoflavonoid isolated from dietary soybean, has been shown to suppress the growth of several cancers through modulation of various pathways. However, the molecular mechanisms by which genistein elicit its effects on colorectal cancer (CRC) cells have not been fully elucidated. In this study, we aimed to investigate the anti-tumor activities of genistein on CRC and its potential mechanism. METHODS Effects of genistein on the cell proliferation were tested in HCT-116 cells by MTT assay, and apoptosis was measured by Flow cytometry. Real-time PCR was also used to evaluate the regulation of genistein on miR-95, Akt and SGK1 expression. The protein levels of total Akt (T-Akt), and phosphorylated Akt (P-Akt) were assessed by western blot. A nude mice xenograft model was employed to determine whether genistein could have an anti-tumor effect on CRC in vivo. RESULTS We found that treatment of HCT-116 cells with genistein caused an inhibition of cell proliferation and induction of apoptosis. Meanwhile, genistein down-regulated the mRNA expression of Akt, SGK1 and miR-95, and inhibited the phosphorylation of Akt in HCT-116 cells. The experiment in vivo also showed that genistein significantly suppressed the growth of mouse xenograft tumor. CONCLUSION This study demonstrates that genistein has an inhibitory effect on CRC involved in reducing miR-95, Akt and SGK1, offering novel insights into the mechanisms of genistein therapeutic actions.