Potent cell growth inhibitory effects in hepatitis B virus X protein positive hepatocellular carcinoma cells by the selective cyclooxygenase-2 inhibitor celecoxib.
Hepatitis B virus (HBV) X protein (HBx) and cyclooxygenase-2 (COX-2) are all playing roles in hepatocellular carcinoma (HCC), but the reversing effects of COX-2 inhibitors on the neoplastic features caused by HBx protein is still unclear. To further evaluate the therapeutic potential of celecoxib on HBx mediated transformation, HCC cells transfected with HBx gene were treated with COX-2 selective inhibitor, celecoxib. The amount the main metabolite of COX-2, prostaglandin E2 (PGE2), was determined by using high sensitivity ELISA. Electron microscope and flow cytometry was used to analyze cell apoptosis and cell cycle distribution. RT-PCR and Western blot were used to identify the molecules involved in celecoxib induced cell apoptosis. The results showed that celecoxib inhibited cell growth more significantly and also induced more cell apoptosis in HBx over-expression cells than in control cells. Celecoxib could selectively inhibited COX-2 expression and PGE2 production. Celecoxib also inhibited p(473Ser)Akt, raf and p53 expression, and induced apoptosis by release of cytochrome c and activation of caspase 9, 3, and 6, which were more remarkably in HBx positive cells than in control cells. These results suggest that celecoxib had potent cell growth inhibitory effects on HBx positive HCC cells mainly through inducing more cell apoptosis, and these findings provide a new insight into the anticancer effects of celecoxib against HBx related HCC.
State Key Laboratory of Cancer Biology, Department of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi Province, People's Republic of China.
Huahong
H
Xie
Liucun
L
Gao
Na
N
Chai
Jiugang
J
Song
Jun
J
Wang
Zhenshun
Z
Song
Caiping
C
Chen
Yanglin
Y
Pan
Lina
L
Zhao
Shiren
S
Sun
Kaichun
K
Wu
Mark A
MA
Feitelson
Jie
J
Liu
Daiming
D
Fan
D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000201:enzymology / Q000473:pathology* / Q000821:virology; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D000068579:Celecoxib; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000737:chemistry / Q000378:metabolism; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology*; D015232:Dinoprostone / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D047468:Immunoprecipitation; D008113:Liver Neoplasms / Q000201:enzymology / Q000473:pathology* / Q000821:virology; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism; D011720:Pyrazoles / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013449:Sulfonamides / Q000494:pharmacology*; D015534:Trans-Activators / Q000502:physiology*; D014162:Transfection; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D054334:Viral Regulatory and Accessory Proteins / Q000502:physiology*
D061945:Caspase Inhibitors; D052246:Cyclooxygenase 2 Inhibitors; D011720:Pyrazoles; D012333:RNA, Messenger; D013449:Sulfonamides; C495901:TP53 protein, human; D015534:Trans-Activators; D016159:Tumor Suppressor Protein p53; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D051057:Proto-Oncogene Proteins c-akt; D019908:Proto-Oncogene Proteins c-raf; D020169:Caspases; D000068579:Celecoxib; D015232:Dinoprostone