Abstract: Background and purpose: MiR-224 is overexpressed in hepatocellular carcinoma, and participate in invasion and metastasis of cancer. The aim of this study was to investigate the effects of miR-224 antisense oligonucleotide (ASO) on the proliferation and apoptosis of Hep3B cells. Methods: After transfection with miR-224 ASO, and detecting the miR-224 mRNA expression of Hep3B cells by real-time quantitative PCR; the miR-224 expression in Hep3B cells was measured and cell proliferation was analyzed by MTT assay and the colony formation experiment in vitro and in vivo. The cell apoptosis was analyzed by flow cytometry. Results: Compared with the control group, miR-224 ASO significantly reduced the miR-224 mRNA expression in the Hep3B cell(P<0.05), MTT assay results showed that Hep3B cells survived rate decreased greatly after transfection with miR-224 ASO. Clone formation assay revealed that the colony formation rate in miR-224 ASO group was significantly lower than that in the control group. In vivo study further confirmed that miR-224 ASO could inhibit the proliferation of Hep3B cells, and miR-224 ASO group grew substantially slow compared with the negative control. Flow cytometry indicated that miR-224 ASO group promoted apoptosis significantly. Conclusion: miR- 224 was overexpressed in Hep3B cells. Reducing the expression of miR-224 can effectively inhibit the growth of Hep3B cells and promote apoptosis. miR-224 may become a new target for the regulation of gene expression in hepatocellular
carcinoma.

Key words: miR-224, Hep3B, Antisense oligonucleotides, Cell proliferation, Apoptosis