The cyclooxygenase-2 inhibitor celecoxib blocks phosphorylation of Akt and induces apoptosis in human cholangiocarcinoma cells.
The expression of cyclooxygenase (COX)-2 is increased in human cancers including cholangiocarcinoma. This study was designed to evaluate the effect and mechanisms of the selective COX-2 inhibitor celecoxib in the growth control of human cholangiocarcinoma cells. Immunohistochemical analysis using human cholangiocarcinoma tissues showed increased levels of COX-2 as well as phospho-Akt (Thr (308)), a protein kinase activated by COX-2-mediated prostaglandins, in human cholangiocarcinoma cells. Treatment of cultured human cholangiocarcinoma cells (HuCCT1, SG231, and CCLP1) with celecoxib resulted in a dose- and time-dependent reduction of cell viability. Fluorescence microscopy, Western blot, and caspase activity assays demonstrated that celecoxib induced morphological features of apoptosis, activation of caspase-9 and caspase-3, and release of cytochrome c. The celecoxib-induced cell death was significantly blocked by N-benzyloxy-carbonyl-Val-Ala-Asp-fluoromethylketone, a wide-spectrum caspase inhibitor. Furthermore, cholangiocarcinoma cells treated with celecoxib showed significant reduction of Akt phosphorylation, whereas the levels of Bcl-2 and Bax were not altered. Inhibition of Akt activation by LY294002 significantly decreased the viability of human cholangiocarcinoma cells. These findings suggest that celecoxib inhibits cholangiocarcinoma growth partly through induction of apoptosis and inhibition of Akt phosphorylation.
Wu
Tong
T
Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. wut@msx.upmc.edu
Leng
Jing
J
Han
Chang
C
Demetris
Anthony Jake
AJ
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D015153:Blotting, Western; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D000068579:Celecoxib; D016923:Cell Death; D045744:Cell Line, Tumor; D002470:Cell Survival; D018281:Cholangiocarcinoma / Q000188:drug therapy* / Q000473:pathology*; D002867:Chromones / Q000494:pharmacology; D051546:Cyclooxygenase 2; D045304:Cytochromes c / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D006801:Humans; D007118:Immunoassay; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000037:antagonists & inhibitors*; D008565:Membrane Proteins; D008856:Microscopy, Fluorescence; D009025:Morpholines / Q000494:pharmacology; D010766:Phosphorylation; D011451:Prostaglandin-Endoperoxide Synthases; D011453:Prostaglandins / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011720:Pyrazoles; D013449:Sulfonamides / Q000494:pharmacology*; D013912:Threonine / Q000737:chemistry; D013997:Time Factors; D051028:bcl-2-Associated X Protein
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000970:Antineoplastic Agents; C494826:BAX protein, human; D002867:Chromones; D007527:Isoenzymes; D008565:Membrane Proteins; D009025:Morpholines; D011453:Prostaglandins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011720:Pyrazoles; D013449:Sulfonamides; D051028:bcl-2-Associated X Protein; D013912:Threonine; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D045304:Cytochromes c; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; C505407:CASP3 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases; D000068579:Celecoxib; D015232:Dinoprostone