Relationship Between Hepatitis B Virus X Protein and Telomerase

Telomeres, short tandem repeat sequences at the ends of eukaryotic linear chromosomes, function to stabilize chromosomes. Telomerase, a reverse transcriptase, is essential for maintaining telemere length and involves in cell proliferation, senescence, immortalization and carcinogenesis. The telomerase changes remarkably in tumor cells with high level expression and strong activity, which becomes one of the characteristics of tumor cells. Hepatitis B virus (HBV) X protein (HBx) is closely related to the occurrence of hepatocelullar carcinoma (HCC) and plays a crucial role in the development of HCC through regulating many pathways, among which human telomerase reverse transcriptase (hTERT) activation by HBx is important in cell immortalization and carcinogenesis. Therefore, it is significant to demonstrate the relationship between HBx and hTERT for exploring the carcinogenesis. In the present review, we describe the structure of HBV genome and biological characteristics, and summarize the relationship between HBx and hTERT, its regulating factors as well, which contribute to the investigation of carcinogenesis.