Celecoxib induces apoptosis in cervical cancer cells independent of cyclooxygenase using NF-kappaB as a possible target.
OBJECTIVE
Recently, many studies have shown that celecoxib induces apoptosis in various cancer cells by different mechanisms depending on the cell type. This study examined the apoptotic effect of celecoxib in cervical cancer cells and its mechanism.


METHODS
Cell viability was measured by MTT assay and apoptosis was examined by DNA fragmentation and flow cytometry. Western blotting and immunoprecipitation were used to explore various mechanisms of celecoxib-induced apoptosis. The activation of NF-kappaB was confirmed by EMSA.


RESULTS
Celecoxib induced apoptosis independent of COX-2 activity. This event accompanied the activation of caspase-8 and -9 with Bid cleavage and the loss of mitochondrial membrane potential. The protective effect of caspase-8 and -9 inhibitors on celecoxib-induced apoptosis suggests the importance of caspase-8 and -9 activation in this apoptotic pathway. Fas/FADD-mediated apoptotic pathway was detected only in C33A cells, demonstrated by the immunoprecipitation of Fas-FADD in celecoxib-treated cells and the protective effect of FADD dominant negative mutant. Finally, NF-kappaB appeared to be involved in celecoxib-induced apoptosis, as revealed by increased NF-kB DNA binding activity in a time-dependent manner and attenuation of its proapoptotic effect by N-tosyl-L-phenylalanyl-chloromethyl ketone, an NF-kB blocker.


CONCLUSIONS
These data show that caspase-8 and -9 are involved in the apoptotic effect of celecoxib in cervical cancer cells. This requires the FADD-dependent pathway in a cell type-specific manner. In addition, NF-kappaB may play a key role in celecoxib-induced apoptosis.
Kim
Su-Hyeong
SH
Cancer Research Institute, College of Medicine Seoul National University, Seoul, Korea.
Song
Sang-Hyun
SH
Kim
Sang-Gyun
SG
Chun
Kyung-Soo
KS
Lim
So-Young
SY
Na
Hye-Kyung
HK
Kim
Jae Weon
JW
Surh
Young-Joon
YJ
Bang
Yung-Jue
YJ
Song
Yong-Sang
YS
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D020169:Caspases / Q000187:drug effects; D000068579:Celecoxib; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D053938:DNA Fragmentation / Q000187:drug effects; D024202:Electrophoretic Mobility Shift Assay; D053200:Fas-Associated Death Domain Protein; D005260:Female; D005434:Flow Cytometry; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D008565:Membrane Proteins; D016328:NF-kappa B / Q000187:drug effects* / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases; D011720:Pyrazoles / Q000494:pharmacology*; D013449:Sulfonamides / Q000494:pharmacology*; D002583:Uterine Cervical Neoplasms / Q000188:drug therapy* / Q000201:enzymology
D048868:Adaptor Proteins, Signal Transducing; D000970:Antineoplastic Agents; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; C505533:FADD protein, human; D053200:Fas-Associated Death Domain Protein; D007527:Isoenzymes; D008565:Membrane Proteins; D016328:NF-kappa B; D011720:Pyrazoles; D013449:Sulfonamides; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D020169:Caspases; D000068579:Celecoxib