Mitomycin C induces apoptosis in a caspases-dependent and Fas/CD95-independent manner in human gastric adenocarcinoma cells.
We investigated the mechanism of mitomycin C (MMC)-induced apoptosis in SNU-16 human gastric adenocarcinoma cells. Caspase-8 and caspase-3 were activated in MMC-treated cells whereas caspase-1 was not activated, and cytochrome c was released from mitochondrial membrane to cytosol suggesting that caspase-9 was activated during the MMC-induced apoptotic process. Protein kinase C (PKC) delta was cleaved to its characteristic 40 kDa fragment in a caspase-3-dependent manner; on the other hand PKC zeta was cleaved to approximately 40 kDa independently of caspase-3 in the drug-induced apoptosis of the cells. Incubation with z-DEVD-fmk and benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (z-VAD-fmk) almost completely abrogated MMC-induced DNA fragmentation, indicating that activation of these caspases was crucially involved in MMC-induced apoptosis. Activation of caspase-8 in response to Fas triggering by recruitment of caspase-8 to the Fas has also been found, however, MMC did not induce FasL and Fas expression, as evidenced by reverse transcriptase-polymerase chain reaction and Western blotting. Taken together, these findings indicate that MMC-induced apoptosis in SNU-16 cells was mediated by caspase-8, caspase-9, and caspase-3 activation independently of FasL/Fas interactions.
Park
I C
IC
Laboratory of Cell Biology, Korea Cancer Center Hospital, 215-4 Gongneung-dong, Nowon-ku, 139-240, Seoul, South Korea.
Park
M J
MJ
Hwang
C S
CS
Rhee
C H
CH
Whang
D Y
DY
Jang
J J
JJ
Choe
T B
TB
Hong
S I
SI
Lee
S H
SH
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D016685:Mitomycin / Q000494:pharmacology*; D009842:Oligopeptides / Q000494:pharmacology; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D013997:Time Factors; D014407:Tumor Cells, Cultured; D019014:fas Receptor / Q000378:metabolism
D000590:Amino Acid Chloromethyl Ketones; D000903:Antibiotics, Antineoplastic; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D009842:Oligopeptides; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D019014:fas Receptor; D016685:Mitomycin; C505407:CASP3 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases