Objective Hepatitis B virus X (HBx) protein is involved in the initiation and progression of hepatocellular carcinoma (HCC) by regulating the host protein-coding genes. Herein, we want to explore whether HBx protein can alter the expression of microRNAs (miRNAs) to promote proliferation and transformation in malignant hepatocytesin vitro. Methods MiRNA microarray and quantitative reverse-transcription polymerase chain reactions (qRT-PCRs) were performed to identify miRNAs that were differentially regulated by HBx protein in HCC cells. Protein and mRNA expression analyses, cell cycle and apoptosis analyses, and luciferase reporter assays were performed to delineate the consequences of miR-16 family repression in HepG2 cells. Results HBx protein induced widespread deregulation of miRNAs in HepG2 cells, and the downregulation of the miR-16 family was reproducible in HepG2, SK-HEP-1, and Huh7 cells. CCND1, a target gene of the miR-16 family, was derepressed by HBx protein in HepG2 cells. C-myc mediated the HBx-induced repression of miR-15a/16 in HepG2 cells. Ectopically expressed miR-15a/16 suppressed the proliferation, clonogenicity, and anchorage-independent growth of HBx-expressing HepG2 cells by arresting them in the G1 phase and inducing apoptosis, whereas reduced expression of miR-16 accelerated the growth and cell-cycle progression of HepG2 cells. Conclusions HBx protein altered thein vitro expression of miRNAs in host malignant hepatocytes, particularly downregulating the miR-16 family. Repression of miR-15a/16 is c-myc mediated and is required for the HBx-induced transformation of HepG2 cellsin vitro. Therefore, miR-16 family may serve as a therapeutic target for hepatitis B virus (HBV)-associated HCC.
ObjectiveTo summarize the research status of the relationship between hepatitis B virus X protein (HBx), hepatitis B virus (HBV) genotypes and hepatocellular carcinoma (HCC) at home and abroad, and to prospect its clinical significance.MethodThe literatures about HBx, HBV genotypes and HCC were reviewed.ResultsThere was a close relationship between HBx and the occurrence, development, migration and metastasis of HCC. There was a certain association between HBV genotypes and HCC, but the specific mechanism had not been clarified.ConclusionsHBx and HBV genotypes play an important role in the occurrence and development of HCC. With the further study of molecular mechanism, it will promote the diagnosis and treatment of hepatitis B, liver cirrhosis and liver cancer, and provide more individualized intervention for clinical workers.