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.
Department of Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
M A
MA
Feitelson
M
M
Zhu
L X
LX
Duan
W T
WT
London
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