Induction of hepatitis B surface antigen in human hepatoma-derived cell lines.
Cultures of two human hepatoma cell lines were examined for expression of hepatitis B virus surface antigen (HBsAg). The PLC/PRF/5 cells secreted HBsAg continuously into the culture medium, whereas Mahlavu cells did not secrete the antigen. However, cytoplasmic antigen was detected in a low percentage (less than 5%) of the Mahlavu cells. The expression of HBsAg also was assayed in cultures treated wtih dexamethasone (DXM), 5-iodo-2'-deoxyuridine (IdUrd), or both. The results demonstrated that: (i) DXM stimulated secretion of HBsAg by PLC/PRF/5 cells but not by Mahlavu cells; (ii) the percentage of Mahlavu cells expressing cytoplasmic HBsAg was not increased in any cultures if the medium was replaced at 24 t0 48 h intervals but was increased approx. fivefold within 4 days in cultures treated with DXM or IdUrd/DXM if the medium was not changed. However, no increase was noted in the intensity of the immunoperoxidase stain of PLC/PRF/5 cells that expressed cytoplasmic antigen in any DXM cultures; (iii) HBsAg expression was stimulated to a lesser extent in IdUrd/DXM cultures than in DXM cultures and was not enhanced in IdUrd cultures. Thus, DXM enhanced secretion of HBsAg by PLC/PRF/5 cells within 24 h and, after a delay, enhanced expression of cytoplasmic antigen by Mahlavu cells. However, antigen secretion by Mahlavu cells evidently was blocked.
D006528:Carcinoma, Hepatocellular; D002460:Cell Line; D003470:Culture Media; D003907:Dexamethasone / Q000494:pharmacology; D006512:Hepatitis B Core Antigens / Q000032:analysis; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D006801:Humans; D007065:Idoxuridine / Q000494:pharmacology; D007124:Immunoenzyme Techniques; D008113:Liver Neoplasms
D003470:Culture Media; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D003907:Dexamethasone; D007065:Idoxuridine