Hepatitis B Virus X Protein Induces Expression Changes of miR-21, miR-22, miR-122, miR-132, and miR-222 in Huh-7 Cell Line.

Hepatitis B virus (HBV) X protein (HBx) plays a key role in hepatocellular carcinoma (HCC). HBx may alter the expression of multiple microRNAs (miRs), which are important in hepatocarcinogenesis. This study aimed to investigate the importance of HBx protein in the expression of miR-21, miR-22, miR-122, miR-132, and miR-222. A recombinant vector expressing HBx was developed. The Huh-7 cell line was transfected with the HBx-pcDNA3.1+ recombinant plasmid. A Real-Time Polymerase Chain Reaction was used to evaluate the expression of miR-21, miR-22, miR-122, miR-132, and miR-222 in the cell line. It was found that the expression of miR-21 and miR-222 was upregulated at all points of time after HBx transfection. The expression of miR-21 was 4.24-fold 72 h after transfection. The miR-22 had a 7.69-fold downregulation after 24 h, and the miR-122 had a significant downregulation after 48 h (10-fold). The miR-132 expression reached its lowest rate 12 h after HBx transfection (8.33-fold), and the miR-222 expression was upregulated in transfected cells but was not significantly different (1.18- to 2.45-fold). The significant downregulation of miR-22, miR-122, and miR-132 implicates their inhibitory roles in the progression of HBV-associated HCC. The expression of these microRNAs could be used as a prognostic marker for the progression of HBV-associated liver disease.