Mechanism of inhibitory effect of miRNA-33a on proliferation of HCT-116 cells

Objective To explore the mechanism of chemically synthesized miRNA-33a inhibiting proliferation activity of colon cancer cells HCT-116. Methods HCT-116 cells were transfected with miRNA-33a mimics, miRNA-33a inhibitor and miRNA-33a negative control (NC). The contents of miRNA-33a in the transfected cells and changes of Twist protein expression were detected by real-time PCR and Western blotting respectively 48 hours after transfection; the changes in cell proliferation activity were measured using CCK-8 method 72 hours after transfection. Bioinformatic software was used to predict the binding site of miRNA-33a with Twist, and a luciferase reporter method was used to verify whether there is the target site of miRNA-33a in Twist gene. Results Transfection of HCT-116 cells with miRNA-33a mimics significantly increased miRNA-33a mRNA and decreased Twist protein expression (P<0.05), but the transfection with miRNA-33a inhibitor significantly decreased miRNA-33a mRNA and increased Twist protein expression (P<0.05); moreover, miRNA-33a mimics significantly inhibited proliferation activity of HCT116 cells and miRNA-33a inhibitor significantly enhanced cell proliferation activity 48 and 72h after transfection compared with the control group (P