The lncRNA MIR4435-2HG is upregulated in hepatocellular carcinoma and promotes cancer cell proliferation by upregulating miRNA-487a

BACKGROUND: Given the high mortality rate and unclear pathogenesis for liver cancer, investigation of its molecular mechanisms is essential. We focused on the long non-coding RNA (lncRNA) MIR4435-2HG, which was recently reported to be oncogenic in lung cancer and the microRNA miRNA-487a, which has been reported to be oncogenic in hepatocellular carcinoma (HCC). Our aim was to determine if the former has a role in HCC, and to further validate the role of the latter. METHODS: Samples from 64 patients with HCC were taken at The Third Affiliated Hospital of Sun Yat-Sen University. Cell transfection and PCR were applied. RESULTS: We found that MIR4435-2HG and miRNA-487a were upregulated in tumor tissues compared to adjacent healthy tissues from HCC patients. The expression of MIR4435-2HG was significantly affected by tumor size but not by tumor metastasis. Correlation analysis showed that MIR4435-2HG and miRNA-487a were positively correlated in both the tumor tissues and adjacent healthy tissues from HCC patients. Overexpression of MIR4435-2HG led to upregulation of miRNA-487a in the cells of HCC cell lines, while overexpression of miRNA-487a did not significantly affect MIR4435-2HG. Overexpression of MIR4435-2HG and miRNA-487a promoted the proliferation of cells of HCC cell lines, and miRNA-487a knockdown partially attenuated the enhancing effects of MIR4435-2HG overexpression on cancer cell proliferation. CONCLUSION: MIR4435-2HG is upregulated in HCC and promotes cancer cell proliferation possibly by upregulating miRNA-487a.