The expression of microRNA-133a in hepatocellular carcinoma tissue and its contribution to the regulation of biological function in human hepatocellular carcinoma cell line

Objective To investigate the expression of microRNA (miRNA, miR)-133a in hepatocellular carcinoma (HCC) tissues and its contribution to the regulation of biological function in HCC cell line Huh7. Methods The expression of miR-133a in HCC tissues and adjacentnon-tumor liver tissues was detected by real-time quantitative polymerase chain reaction (Real-time PCR). The methyl thiazol tetrazolium (MTT) assay, scrape assay and Transwell assay were used to investigate the contribution of miR-133a on biological behaviors of HCC cells. Results The expression of miR-133a was significantly down-regulated in HCC tissues as compared with the adjacent non-tumor liver tissues (0.40±0.17 vs. 1.10±0.32, P=0.000). Also miR-133a level was significantly decreased in HCC cell lines relative to the normal hepatic cell line, LO2 (0.40±0.17 vs. 1.10±0.32, P=0.000). The MTT cell proliferation experiment showed that the proliferation rate of forced expression miR-133a group was lower than the control after cultured for 36, 48, 72 h (0.40±0.03 vs. 0.55±0.03; 0.44±0.02 vs. 0.66±0.02; 0.64±0.04 vs. 1.14±0.03, P=0.000). Cell cycle analysis revealed that forced expression miR-133a Huh7 cells were arrested in G1 phase (41.69±1.22 vs. 54.23±4.35, P=0.000). In wound healing assay, the number of Huh7 cells was significantly decreased after transfection of miR-133a (P=0.016), while the invasive ability of Huh7 cells had no significant difference after transfection of miR-133a. Conclusion The expression of miR-133a in HCC tissues and HCC cell lines was down-regulated. Forced expression of miR-133a in HCC cell lines significantly inhibited cell proliferation and migration, suggesting that abnormal expression of miR-133a in HCC could be involved in the regulation of the tumor biological behaviors and contribute to the tumor progression. Key words: Carcinoma, hepatocellular; MicroRNA-133a; Cell proliferation