title: Pretreatment of acetylsalicylic acid promotes tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis by down-regulating BCL-2 gene expression.
abstract: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been shown to be selective in the induction of apoptosis in cancer cells with minimal toxicity to normal tissues. However, not all cancers are sensitive to TRAIL-mediated apoptosis. Thus, TRAIL-resistant cancer cells must be sensitized first to become responsive to TRAIL. In this study, we observed that pretreatment by acetylsalicylic acid (ASA) augmented TRAIL-induced apoptotic death in human prostate adenocarcinoma LNCaP and human colorectal carcinoma CX-1 cells. Western blot analysis showed that pretreatment of ASA followed by TRAIL treatment activated caspases (8, 9, and 3) and cleaved poly(ADP-ribose) polymerase, the hallmark feature of apoptosis. Most interestingly, at least 12 h of pretreatment with ASA was prerequisite for promoting TRAIL-induced apoptosis and was related to down-regulation of BCL-2. Biochemical analysis revealed that ASA inhibited NF-kappaB activity, which is known to regulate BCL-2 gene expression, by dephosphorylating IkappaB-alpha and inhibiting IKKbeta activity but not by affecting the HER-2/neu phosphatidylinositol 3-kinase-Akt signal pathway. Overexpression of BCL-2 suppressed the promotive effect of ASA on TRAIL-induced apoptosis and changes in mitochondrial membrane potential. Taken together, our studies suggested that ASA-promoted TRAIL cytotoxicity is mediated through down-regulating BCL-2 and by decreasing mitochondrial membrane potential.
authors.affiliation: Department of Surgery and Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
authors.forename: Ki M
authors.initials: KM
authors.lastname: Kim
authors.forename: Jae J
authors.initials: JJ
authors.lastname: Song
authors.forename: Jee Young
authors.initials: JY
authors.lastname: An
authors.forename: Yong Tae
authors.initials: YT
authors.lastname: Kwon
authors.forename: Yong J
authors.initials: YJ
authors.lastname: Lee
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000494:pharmacology*; D001241:Aspirin / Q000494:pharmacology*; D015153:Blotting, Western; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms; D024202:Electrophoretic Mobility Shift Assay; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects*; D019254:Genes, bcl-2 / Q000235:genetics*; D006801:Humans; D051550:I-kappa B Kinase / Q000037:antagonists & inhibitors; D020672:I-kappa B Proteins / Q000378:metabolism; D020287:In Situ Nick-End Labeling; D008297:Male; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects*; D008928:Mitochondria / Q000187:drug effects; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors; D010766:Phosphorylation; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011471:Prostatic Neoplasms; D011994:Recombinant Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053221:TNF-Related Apoptosis-Inducing Ligand; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D051017:Apoptosis Regulatory Proteins; D004791:Enzyme Inhibitors; D020672:I-kappa B Proteins; D008562:Membrane Glycoproteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D011994:Recombinant Proteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D000072000:NF-KappaB Inhibitor alpha; D011065:Poly(ADP-ribose) Polymerases; D051550:I-kappa B Kinase; C505407:CASP3 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; D001241:Aspirin