[Hepatitis B virus X protein suppresses adriamycin-induced apoptosis of hepatocellular carcinoma cells and expression of p53 and PTEN].
OBJECTIVE
To investigate the effect of hepatitis B virus X protein (HBx) on adriamycin-induced apoptosis of hepatocellular carcinoma cells and the expressions of p53 and PTEN.


METHODS
HepG2, HepG2/GFP, and HepG2/GFP-HBx cells were treated with adriamycin (2.5 microg/ml), and the apoptotic cell death was determined by observing the morphological changes and flow cytometry. The expressions of p53 and PTEN mRNA in the 3 cells were detected by RT-PCR, and the expressions of p53 and PTEN protein were analyzed by Western blotting.


RESULTS
Adriamycin induced significant cell death in HepG2 and HepG2/GFP cells, which became rounded, shrunk, and detached after the treatment; but no significant cell death occurred in HepG2/GFP-HBx cells. Flow cytometry analysis showed that the apoptotic rate was significantly lower in HepG2/GFP-HBx cells (3.94%) than in HepG2 (59.03%) and HepG2/GFP cells (61.38%) at 36 h after the treatment (P<0.001), while no significant difference was observed between HepG2/GFP-HBx (3.94%) and the control cells (2.12%, 2.78%, and 2.55%) (P>0.05). RT-PCR showed lowered expression of PTEN mRNA in HepG2/GFP-HBx cells as compared to that in HepG2 and HepG2/GFP cells, while no significant difference was noted in p53 mRNA. Western blot analysis showed that PTEN protein decreased while p53 protein remain unchanged in HepG2/GFP-HBx cells.


CONCLUSIONS
HBx suppresses adriamycin-induced apoptosis of HepG2 cells and PTEN expression. The inhibitory effect of HBx on the cell apoptosis may be related to the inhibition of p53-PTEN pathway.
Wang
Xia
X
Department of Liver Diseases, Shenzhen Second People's Hospital, Shenzhen 518035, China. szftwangxia@163.com
Yang
Lin
L
She
Ji-jia
JJ
Fan
Hong-mei
HM
Zhang
Fu-cheng
FC
Chen
You-ming
YM
Xie
Qi-feng
QF
D017209:Apoptosis / Q000187:drug effects; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D004317:Doxorubicin / Q000494:pharmacology; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D051059:PTEN Phosphohydrolase / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D054334:Viral Regulatory and Accessory Proteins
C495901:TP53 protein, human; D015534:Trans-Activators; D016159:Tumor Suppressor Protein p53; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein; D004317:Doxorubicin; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human