MiR-138 promotes apoptosis of colon cancer cells by targeting SIRT1

Abstract

Objective To investigate the mechanism of miR-138 involving in the apoptosis of colon cancer cells by regulating SIRT1. Methods RT-qPCR was used to detect the expression of miR-138 in colon cancer cell lines HCT 116, SW480, Caco-2, HT29 and SW1116. The luciferase reporter plasmid was constructed and the target molecule was verified by double luciferase assay. MiR-138 mimics, miR-138 inhibitor and miR-138 NC (negative control) were transfected into HT29 and Caco-2 cells, respectively. The expression levels of miR-138, SIRT1, Caspase-3 and Bcl-2 in the cells of each group were detected by RT-qPCR and Western blotting, and the apoptosis of Caco-2 and HT29 cells was detected by flow cytometry. Results MiR-138 showed the lowest expression level in Caco-2 cells and the highest expression level in HT29 cells. SIRT1 was identified as a direct target of miR-138 in HT29 cells, and miR-138 inhibited SIRT1 expression at both mRNA and protein levels. After transfection of miR-138 mimics into Caco-2 cells, the expression of SIRT1 and Bcl-2 was significantly decreased (P < 0.05), Caspase-3 was enhanced (P < 0.05), meanwhile the apoptosis was increased (P < 0.05). Whereas after miR-138 inhibitor transfected into HT29 cells, the expression of SIRT1 and Bcl-2 was obviously increased (P < 0.05), Caspase-3 was decreased (P < 0.05), and the apoptosis reduced (P < 0.05). Conclusion MiR-138 promotes apoptosis of colon cancer cells by regulating the expression of its target SIRT1.

Keywords

• colon cancer cells
• mir-138
• sirt1
• apoptosis