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Hepatitis B e antigen and its precursors promote the progress of hepatocellular carcinoma by interacting with NUMB and decreasing p53 activity
Author(s) -
Liu Dan,
Cui Lei,
Wang Yuan,
Yang Guifang,
He Jing,
Hao Ruidong,
Fan Chengpeng,
Qu Mengmeng,
Liu Zhepeng,
Wang Min,
Chen Lang,
Li Hui,
Guo Deyin
Publication year - 2016
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.28594
Subject(s) - numb , hepatocellular carcinoma , hbeag , cancer research , carcinogenesis , biology , liver cancer , hepatitis b virus , viral hepatitis , chemistry , cancer , virology , microbiology and biotechnology , hbsag , virus , genetics
Hepatitis B viral infection is one of the leading causes of hepatocellular carcinoma (HCC) worldwide. Although several viral factors have been identified that may increase the risk for HCC development, the molecular mechanisms leading to the transformation of normal hepatocytes into cancer cells remain elusive. In this study, we demonstrated that the intracellular hepatitis B e antigen (HBeAg) and its precore precursors, but not their homologous core protein, could associate with NUMB and thereby impair the stability and transcriptional activity of tumor suppressor p53. HBeAg and its precursors could disrupt p53‐NUMB and HDM2‐NUMB interactions and tricomplex p53‐HDM2‐NUMB formation, inhibit the acetylation and translocation of p53 from cytosol to the nucleus, promote HDM2‐mediated ubiquitination and degradation of p53, and suppress p53‐dependent apoptosis. A xenograft tumorigenicity assay showed that expression of HBeAg and its precursors promoted carcinogenesis in a mouse model. Immunohistochemical analysis of the bioptic liver samples of HCC patients revealed that HBeAg positivity was associated with reduced transcriptional activity of p53. Taken together, the results suggest a role of intracellular HBeAg and its precursors in HCC development. Conclusion : HBeAg and its precursors promote HDM2‐mediated degradation and impair transcriptional activity of p53 by interacting with NUMB, consequently contributing to HCC development. (H epatology 2016;64:390‐404)