Huang Richard-H, Chai Jianyuan, Tarnawski Andrzej-S
Department of Medicine, Division of Gastroenterology, University of California Irvine and VA Long Beach Healthcare System, California, United States.
World J Gastroenterol. 2006 Oct 28;12(40):6446-52. doi: 10.3748/wjg.v12.i40.6446.
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.
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.
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.
(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.
研究非选择性环氧化酶（COX）抑制剂吲哚美辛（IND）或COX-2选择性抑制剂NS-398（NS）是否能诱导人结肠癌细胞凋亡，以及涉及哪些凋亡相关基因和途径。
将人结肠癌Caco-2细胞分别用安慰剂、IND（0.05 - 0.5 mmol/L）或NS（0.01 - 0.2 mmol/L）处理1、5和18小时。然后我们研究：（1）通过TUNEL法检测细胞死亡情况；（2）使用DNA微阵列研究96个凋亡相关基因的mRNA表达；（3）通过蛋白质免疫印迹法检测所选凋亡相关蛋白的表达。
IND和NS均以剂量依赖方式诱导30% - 50%的Caco-2细胞凋亡。IND（0.1 mmol/L处理1小时）显著上调了四个家族的促凋亡基因：（1）肿瘤坏死因子受体和配体家族；（2）半胱天冬酶家族；（3）Bcl-2家族；（4）半胱天冬酶募集结构域家族。NS处理上调了与IND相似的促凋亡基因。此外，IND还下调了凋亡抑制蛋白（IAP）家族的抗凋亡基因。
（1）非选择性和COX-2选择性非甾体抗炎药均以剂量依赖方式诱导结肠癌细胞凋亡。（2）两种非甾体抗炎药均通过激活两条主要凋亡途径诱导凋亡：死亡受体途径（涉及肿瘤坏死因子受体）和线粒体途径。（3）IND通过上调促凋亡基因和下调抗凋亡基因诱导凋亡，而NS仅上调促凋亡基因。（4）非甾体抗炎药诱导结肠癌细胞凋亡可能部分解释了它们对结肠癌生长抑制作用的机制。
