环氧合酶-2抑制剂吡罗昔康对结肠癌细胞生长的影响

目的观察非甾体类抗炎药、环氧合酶(COX)-2抑制剂吡罗昔康(Piroxicam)对结肠癌细胞的影响，并结合COX-2蛋白表达和细胞凋亡情况探讨结肠癌的预防。方法细胞株选用SW1116结肠腺癌细胞；细胞增殖实验时，用MTT法测定细胞增殖活性；用免疫组化及Western Blot方法检测细胞内COX-2蛋白表达；用DNA云梯电泳法检测细胞凋亡。结果吡罗昔康能够抑制结肠腺癌细胞的增殖，其效应与浓度呈正相关；浓度≥1．0mmol／L时呈现细胞毒作用。吡罗昔康作用12h即可显著抑制COX-2蛋白的表达；作用24h后，蛋白水平恢复程度与浓度成负相关。吡罗昔康浓度≥0．1mmol／L时可以诱导SW1116细胞的凋亡。结论吡罗昔康抑制结肠腺癌细胞的增殖与抑制COX-2过度表达和促进细胞凋亡有关，由于吡罗昔康的效应呈现浓度和时间依赖性，在进行预防或治疗结肠癌的临床研究时，要考虑其有效剂量和用药间隔。

Effects of cyclooxygenase-2 inhibitor Piroxicam on the growth of colorectal cancer

Objective To study the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) ,cy-clooxygenase-2 ( COX-2 ) inhibitor Piroxicam on the growth of colorectal cancer cells and to evaluate the preventive significance from COX-2 expression and apoptosis. Methods The cell growth of colorectal adenocar-cinoma cell line SW1116 was measured by MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide) assay, and COX-2 protein expression by Immunohistochemistry and Western Blot. Apoptosis was characterized by DNA fragmentation. Results The results showed that COX-2 inhibitor Piroxicam could restrain the proliferation of SW1116, which had positively related to its concentration. Concentration higher than 1. 0mmol/L showed cytotoxic effects. The inhibition of COX-2 by Piroxicam appeared within 12 hours, but COX-2 protein level recovered within 24 hours, its expression had negatively related to the concentration of Piroxicam. Apoptosis was induced in SW1116 culture with Piroxicam higher than 0. 1mmol/L. Conclusion It can be concluded that cell inhibition effect is associated with Piroxicam-mediated cell apoptosis and inhibition of COX-2 protein expression in SW1116 cell, because the effects of Piroxicam have the concentration and time dependence, in further clinical research its dosage and time of medication should be considered in preventing or treating colorectal cancer.