title: Celecoxib, a cyclooxygenase-2 inhibitor, induces apoptosis in human osteosarcoma cell line MG-63 via down-regulation of PI3K/Akt.
abstract: Cyclooxygenase-2 (COX-2), involved in the inhibition of apoptosis and, the potentiation of cell growth, is frequently overexpressed in human malignancies including osteosarcoma (OS). We have attempted to identify the anti-proliferation of celecoxib, a selective COX-2 inhibitor, and the combination of celecoxib and cisplatin in MG-63 cells, and to explore the potential molecular mechanisms involved. MG-63 cells were treated with the combination of celecoxib and cisplatin or either agent alone for 48h in serum-supplemented medium. Celecoxib caused G1 phase arrest and significantly inhibited cell growth, as well as potentiating cisplatin-induced apoptosis. The effect was dose-dependent, and apoptotic changes such as DNA fragments and apoptotic bodies were observed. However, downregulation of COX-2 did not occur in cells treated with celecoxib. Phosphoinositide-3-kinase (PI3K)/Akt, survivin, bcl-2 were significantly downregulated in cells treated with the combination of celecoxib and cisplatin, and decreased survivin and bcl-2 levels were found in cells with wortmannin, a specific PI3K inhibitor. Moreover, the decreased expressions of procaspase-9, procaspase-3 and cleaved PARP-1 were detected by Western blot analysis. Therefore, celecoxib exerts its anti-tumor activities through COX-2-independent mechanisms, which may be PI3K/Akt-dependent, and survivin and bcl-2-related. PI3K may be at the center of the celecoxib effects, which play an essential role in the regulation of survivin and Bcl-2.
authors: Department of Orthopedics, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, #88 Jie Fang Road, Hangzhou, 310009, Zhejiang, PR China.
authors: Bing
authors: B
authors: Liu
authors: Zhong-li
authors: ZL
authors: Shi
authors: Jie
authors: J
authors: Feng
authors: Hui-min
authors: HM
authors: Tao
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D000068579:Celecoxib; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology; D051546:Cyclooxygenase 2 / Q000235:genetics; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D015536:Down-Regulation / Q000187:drug effects*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D012516:Osteosarcoma; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D011720:Pyrazoles / Q000494:pharmacology*; D013449:Sulfonamides / Q000494:pharmacology*; D000077022:Survivin; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D000970:Antineoplastic Agents; D000068579:Celecoxib; D002945:Cisplatin; D051546:Cyclooxygenase 2; D016861:Cyclooxygenase Inhibitors; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt; D019253:Proto-Oncogene Proteins c-bcl-2; D011720:Pyrazoles; D013449:Sulfonamides; D000077022:Survivin; D000077191:Wortmannin; C107489:BIRC5 protein, human; C496540:PTGS2 protein, human