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

Abstract

Background: Hepatocellular carcinoma (HCC) is recognized as one of the most deadly malignant cancers which ranks third among all annual cancer mortality rates. The hepatitis B virus (HBV) X protein (HBX) is known to play a key role in HCC. The 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 mir21, mir22, mi122, mir132, and mir222 expression. Material and Methods: In the present study, a recombinant vector, pcDNA3.1+ expressing HBx was developed. The Huh-7 cell line was transfected with HBx-pcDNA3.1+ recombinant plasmid. Real-Time Polymerase Chain Reaction was used to evaluate mir21, mir22, mi122, mir132, and mir222 expression in the cell line. Results: It was found that expression of miR-21 and miR-222 was upregulated at all points of time since HBx transfection. The expression of miR-21 reached to 4.24-fold after 72 hours post-transfection. The miR-22 had a 7.69-fold downregulation after 24 hours. The miR-122 had a significant downregulation after 48 (10-fold) hours. The miR-132 expression reached its lowest rate at 12 hours after HBx-transfection (8.33-fold). The miR-222 expression was upregulated in transfected cells but was not significantly different (1.18 to 2.45-fold). Conclusion: Significant downregulation of miR-22, miR-122 and miR-132 implicate their inhibitory roles in the progression of HBV-associated HCC. The expression of these microRNAs could be used as a prognosis of the progression of HBV-associated liver disease. Also, in future studies, miR-21 and miR-22 can be used as a target in the development of therapeutic agents.