Caspase-3 activation downstream from reactive oxygen species in heat-induced apoptosis of pancreatic carcinoma cells carrying a mutant p53 gene.
In the present study we investigated the intracellular signaling pathway leading to p53-independent activation of caspase-3 during heat-induced apoptosis of pancreatic carcinoma cells. Induction of mutant p53 protein, but not p21/WAF-1, was observed after heat treatment of both heat-resistant (PANC-1) and heat-sensitive (MIAPaCa-2) cells. A specific inhibitor of caspase-3 (Ac-DMQD-CHO) caused 84% and 92% inhibition of apoptosis in MIAPaCa-2 and PANC-1 cells, respectively. Caspase-3 mRNA expression was increased in both cell lines after heat treatment. Further, heat-induced caspase-3 activity detected by fluorogenic assay in MIAPaCa-2 cells was almost completely inhibited by addition of the antioxidant N-acetyl-L-cysteine. In contrast, Ac-DMQD-CHO had no inhibitory effect on amounts of reactive oxygen species in heat-treated MIAPaCa-2 cells. These results suggest a possible pathway by which reactive oxygen species lead to caspase-3 activation to cause heat-induced death of pancreatic carcinoma cells carrying mutant p53.
Kobayashi
D
D
Department of Clinical Laboratory Medicine, Sapporo Medical University, School of Medicine, Japan.
Sasaki
M
M
Watanabe
N
N
D000111:Acetylcysteine / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis; D053148:Caspase 3; D061945:Caspase Inhibitors; D020169:Caspases / Q000235:genetics / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D053938:DNA Fragmentation; D004789:Enzyme Activation; D015870:Gene Expression; D016158:Genes, p53 / Q000235:genetics*; D006358:Hot Temperature; D006801:Humans; D009154:Mutation; D009842:Oligopeptides / Q000494:pharmacology; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000473:pathology*; D012333:RNA, Messenger / Q000032:analysis; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D000975:Antioxidants; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D009842:Oligopeptides; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C110922:acetyl-aspartyl-methionyl-glutaminyl-aspartyl-aldehyde; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D000111:Acetylcysteine