Effect of miR-7 Overexpression on Biological Behavior of Colon Carcinoma HCT-116 Cells

Objective To explore the effect of up-regulation of microRNA-7 (miR-7) on biological behavior of colon carcinoma HCT-116 cells and its possible mechanism.

Methods Colon carcinoma HCT-116 cells were divided into miR-7 mimics group (HCT-116 cells transfected with miR-7 mimics), Scramble (negative control) group (HCT-116 cells transfected with miR-Scramble) and MOCD group (HCT-116 cells without transfection). RT-Fq-PCR was used to test the expression of miR-7 at 48h after transfection. CCK-8 assay was used to test the proliferation of HCT-116 cells at 48h after transfection. Cell invasion ability was determined by Transwell assay at 48h after transfection. Cell cycle and apoptosis rate were detected by flow cytometry. The protein levels of PI3K(p110), p-Akt and p-mTOR were examined by Western blot.

Results The expression of miR-7 was significantly up-regulated after transfection with miR-7 mimics(P < 0.05). The proliferation and metastasis of HCT-116 cells were extremely decreased after transfection with miR-7 mimics. FCM showed that the rate of G₀/G₁ phase was significantly increased, the number of cells in S phase was significantly decreased, the apoptosis rate was significantly upregulated, and the protein levels of PI3K, p-AKT and p-mTOR were decreased in miR-7 mimics group, compared with the other two groups(P < 0.05).

Conclusion Up-regulation of miR-7 could inhibit the proliferation and metastasis of colon carcinoma HCT-116 cells, and the possible mechanism may be related with inhibiting PI3K/AKT signal pathway.