Identification of specific genes and pathways involved in NSAIDs-induced apoptosis of human colon cancer cells.
OBJECTIVE
To study whether indomethacin (IND), a nonselective cyclooxygenase (COX) inhibitor or NS-398 (NS), a COX-2-selective inhibitor, induces apoptosis in human colon cancer cells and which apoptosis-related genes and pathways are involved.


METHODS
Human colon cancer Caco-2 cells were treated with either: placebo, IND (0.05-0.5 mmol/L) or NS (0.01-0.2 mmol/L) for 1, 5 and 18 h. We then studied: (1) Cell death by the TUNEL method, (2) mRNA expression of 96 apoptosis-related genes using DNA microarray, (3) expression of selected apoptosis related proteins by Western blotting.


RESULTS
Both IND and NS induced apoptosis in 30%-50% of Caco-2 cells in a dose dependent manner. IND (0.1 mmol/L for 1 h) significantly up-regulated pro-apoptotic genes in four families: (1) TNF receptor and ligand, (2) Caspase, (3) Bcl-2 and (4) Caspase recruiting domain. NS treatment up-regulated similar pro-apoptotic genes as IND. In addition, IND also down-regulated anti-apoptotic genes of the IAP family.


CONCLUSIONS
(1) Both non-selective and COX-2-selective NSAIDs induce apoptosis in colon cancer cells in a dose dependent manner. (2) Both NSAIDs induce apoptosis by activating two main apoptotic pathways: the death receptor pathway (involving TNF-R) and the mitochondrial pathway. (3) IND induces apoptosis by up-regulating pro-apoptotic genes and down-regulating anti-apoptotic genes, while NS only up-regulates pro-apoptotic genes. (4) Induction of apoptosis in colon cancer cells by NSAIDs may explain in part, their inhibitory action on colon cancer growth.
Huang
Richard-H
RH
Department of Medicine, Division of Gastroenterology, University of California Irvine and VA Long Beach Healthcare System, California, United States.
Chai
Jianyuan
J
Tarnawski
Andrzej-S
AS
D000230:Adenocarcinoma / Q000235:genetics / Q000473:pathology* / Q000503:physiopathology; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D018938:Caco-2 Cells; D020169:Caspases / Q000235:genetics / Q000378:metabolism; D003110:Colonic Neoplasms / Q000235:genetics / Q000473:pathology* / Q000503:physiopathology; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D009578:Nitrobenzenes / Q000494:pharmacology; D020411:Oligonucleotide Array Sequence Analysis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology
D000894:Anti-Inflammatory Agents, Non-Steroidal; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D009578:Nitrobenzenes; D019253:Proto-Oncogene Proteins c-bcl-2; D018124:Receptors, Tumor Necrosis Factor; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D020169:Caspases; D007213:Indomethacin