MicroRNA expression profiles of LO2 cells expressing the wild-type and mutant HBx gene.

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. Although numerous studies have suggested the potentially oncogenic roles of wild‑type or mutant hepatitis B virus X (HBx) protein in hepatocarcinogenesis, their exact mechanism remains unclear. Increasing evidence suggests that microRNAs (miRNAs) play essential roles in embryogenesis, cell differentiation and carcinogenesis. This study aimed to investigate the effect of HBx on the miRNA expression profile of LO2 cells. We established the LO2 cell line transfected with recombinant plasmid pcDNA3.0/HBx-d382, pcDNA/HBx and plasmid pcDNA3.0 using Lipofectamine™ 2000, which was confirmed by reverse transcription‑polymerase chain reaction (RT-PCR) and western blotting. We then demonstrated the miRNA expression profiles in the stably transfected LO2 cells using a mammalian miRNA microarray containing whole‑human mature and precursor miRNA sequences. The results were confirmed by real-time quantitative PCR (qPCR). RT-PCR and western blot analysis showed that a stably HBx‑transfected LO2 cell line had been successfully established. According to the microarray, compared to LO2/pcDNA3.0 cells, 6 miRNAs were shown to have higher expression and 5 were shown to have decreased expression in LO2/HBx-d382 cells, while 4 up- and 12 downregulated miRNAs were observed in LO2/HBx cells. There were 8 different expression patterns of miRNAs between LO2/HBx and LO2/HBx-d382 cells. All the chip results were consistent with the real‑time PCR data. Consequently, the HBx gene may influence the miRNA expression profile of LO2 cells. Thus, it may be helpful to further investigate the role of HBx in hepatocarcinogenesis and clarify the underlying molecular mechanisms involved.