Hepatitis B x antigen and p53 are associated in vitro and in liver tissues from patients with primary hepatocellular carcinoma.
To test the hypothesis that hepatitis B x antigen (HBxAg) binds to the tumor-suppressor protein p53, immunoprecipitation was carried out with monoclonal anti-x or monoclonal anti-p53 using radiolabeled HBxAg and p53 made by in vitro translation. The results showed that anti-p53 specifically immunoprecipitates HBxAg only in the presence of p53 and that anti-x specifically immunoprecipitates p53 only in the presence of HBxAg. to determine whether HBxAg binds p53 in vivo, immunoprecipitation and Western blot analysis of liver samples from 10 hepatitis B virus (HBV)-infected patients with primary hepatocellular carcinoma (PHC) were carried out. A protein band at 53,000 daltons that specifically immunoprecipitated with a monoclonal anti-x was identified as p53 by Western blotting with a monoclonal anti-p53. Anti-p53 specifically immunoprecipitated bands of 28,000, 17,000 and 13,000 daltons, which were identified as HBxAg polypeptides by Western blotting with anti-HBx. These findings suggest that HBxAg binds to p53 and that this association is important to the development of PHC.
Feitelson
M A
MA
Department of Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
Zhu
M
M
Duan
L X
LX
London
W T
WT
D006528:Carcinoma, Hepatocellular / Q000737:chemistry*; D006511:Hepatitis B Antigens / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008099:Liver / Q000737:chemistry*; D008113:Liver Neoplasms / Q000737:chemistry*; D011233:Precipitin Tests; D015534:Trans-Activators / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D054334:Viral Regulatory and Accessory Proteins
D006511:Hepatitis B Antigens; D015534:Trans-Activators; D016159:Tumor Suppressor Protein p53; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein