Expression of miR-155 in primary hepatocellular carcinoma and its effect on tumor cell proliferation

AIM: To detect the expression of microRNA 155 (miR-155) in hepatocellular carcinoma and to analyze its influence on tumor cell proliferation and apoptosis.

METHODS: The expression of miR-155 in 42 cases of primary liver cancer and matched tumor-adjacent normal tissue was detected by quantitative PCR. The expression of miR-155 in hepatocellular carcinoma cell lines HepG2 and SMMC7721 was inhibited using a miR-155-specific antisense oligonucleotide (ASO-miR-155), and cell proliferation and early apoptosis were then determined by MTT assay and flow cytometry, respectively.

RESULTS: The positive rate of miR-155 expression was significantly higher in hepatocellular carcinoma (52%) than in tumor-adjacent tissue (P < 0.05). After ASO-miR-155 was transfected into HepG2 and SMMC7721 cells using Lipofectamine, the expression of miR-155 was significantly reduced. MiR155 knockdown significantly inhibited growth and promoted early apoptosis of HepG2 and SMMC7721 cells.

CONCLUSION: MiR-155 is overexpressed in hepatocellular carcinoma. Inhibition of miR-155 expression could inhibit growth and induce early apoptosis of hepatocellular carcinoma cells. MiR-155 may become a new target for the treatment of liver cancer.