Abstract:

Objective To explore the expression level of miR-196a in liver cancer tissue and the influence of miR-196a in the proliferation of liver cancer Hep3B cells, and to clarify the possible mechanism of its promotion effect on the poliferation of liver cancer cells. Methods Twenty pairs of fresh surgical specimens of liver cancer and adjacent tissues were collected.The normal liver cells L02 and liver cancer cells SMMC-7721, HepG2, and Hep3B were cultured.The expression levels of miR-196a in liver cancer tissue, adjacent tissue and liver cancer cells were detected with qRT-PCR.The human liver cancer Hep3B cells at the logarithmic phase were randomly divided into control and miR-196a mimics and miR-196a inhibitors groups; the cell viability was analyzed by MTT assay and the miR-196a expression in the Hep3B cells after transfection was detected by qRT-PCR.The cell cycle distribution was determined by flow cytometry.The expression of FOXO1, one of the potential targets of miR-196a, was determined using qRT-PCR and Western blotting method. Results The expression level of miR-196a in liver cancer tissue was significantly higher than that in adjacent tissue (P<0.05).The expression levels of miR-196a in hunan liver ceancer cells SMMC-7721, HepG2, and Hep3B, were significantly higher than that in human normal liver L02 cells(P<0.05).Compared with control group, the expression level of miR-196a mRNA in the Hep3B cells in miR-196a mimics group was significantly increased(P<0.05), but the miR-196a mRNA expression level in the Hep3B cells in miR-196a inhibitors group was signficantly decreased(P<0.05).Compared with control group, the proliferation rate of the Hep3B cells in miR-196a mimics group was significantly increased(P<0.05), but the proliferation rate in miR-196a inhibitors group was significantly decresed(P<0.05) in a time-dependent manner.Compared with control group, the ratio of the Hep3B cells at G₀/G₁ phase 24 h after transfection in miR-196a inhibitors group was significantly increased, but the ratio of cells at S phase was obvionsly decreased(P<0.05).Compared with control group, the mRNA and protein expression levels of FOXO1 in miR-196a mimics group were significantly decreased(P<0.05). Conclusion miR-196a may promote the proliferation of live cancer cells through FOXO1, which indicates that miR-196a may become a new target for dignosis and treatment of liver cancer.

Key words: miR-196a, forkhead box O1, liver neoplasms, cell proliferation