COX-2抑制剂NS398通过抑制前列腺素E2诱导肾癌细胞的凋亡

Apoptosis of renal carcinoma cells induced by NS398 via inhibiting prostaglandin E2

目的:揭示环氧合酶2(COX-2)在肾癌细胞中的表达情况,通过COX-2抑制剂NS398作用肾癌细胞探讨非甾体抗炎药(NSAID)对肾癌细胞增殖作用的影响及其可能的作用机制。方法:采用标准的细胞培养方法对人肾癌786-0细胞进行培养,将NS398分别以25,50,100,150及200μmol/L的剂量加入细胞中作用24及48h后,MTT法检测NS398对肾癌细胞增殖的影响;作用24h后,流式细胞仪测定细胞凋亡的情况,EIA法测定细胞中前列腺素E(2PGE2)含量的变化,Western blotting测定COX-2蛋白表达的情况。结果:NS398对肾癌786-0细胞具有较强的抑制作用,且这种抑制作用随浓度和时间的增加而增大,呈浓度依赖关系(P<0.05);NS398作用肾癌786-0细胞24h后,在细胞周期G0/G1期前出现明显的亚二倍体凋亡峰,随着浓度升高,凋亡峰亦越来越增高(P<0.05);NS398可抑制PGE2释放,并且这种抑制作用呈剂量效应,与对照组相比有统计学意义(P<0.05);不同浓度NS398作用下的肾癌786-0细胞中,COX-2的表达明显减弱,且呈剂量梯度下降。结论:NS398通过诱导凋亡来抑制肾癌786-0细胞的增殖;NS398诱导肾癌786-0细胞的凋亡作用机制可能是通过抑制COX-2的表达,降低肾癌786-0细胞PGE2的合成,减少前列腺素对肿瘤细胞增殖的刺激作用来抑制增殖和促进凋亡的。

Objective： To investigate the expression of cyclooxygenase-2（COX-2 ） in renal carcinoma cells, and to explore the effect of non-steroidal anti-inflammatory drugs （NSAIDs） on the proliferation of renal carcinoma cells by detecting the effect of NS398, a selective inhibitor of COX-2, in renal carcinoma cells. Methods ： Human renal cell carcinoma（ RCC ） cell line 786-0 was cultured with standard technique and treated with 25,50,100,150,and 200 μmol/L of NS398,respectively. The effect of NS398 on the proliferation of 786-0 cells was detected by MTT assay after the administration of NS398 for 24 and 48 hours. The apoptosis, the level of prostaglandin E2 （PGE2）, and the expression of COX-2 in 786-0 cells after the administration of NS398 for 24 hours were determined by flow cytometry, enzyme immunoassay, and Western blotting,respectively. Results： NS398 inhibited the proliferation of 786-0 cells in a time- and concentration-dependent manner （P 〈 0.05）. A typical, subdiploid, apoptotic peak appeared before G0/G1 stage after the administration of NS398 for 24 hours, and the peak increased with the concentration of NS398 （P 〈 0.05 ）. NS398 significantly inhibited the release of PGE2 in 786-0 cells in a dose-dependent manner （P 〈 0.05 ）. The expression of COX-2 significantly decreased after the administration of NS398. Conclusion： NS398 could inhibit the proliferation of 786-0 cells by inducing the apoptosis. The possible mechanism includes down-regulating the expression of COX-2 and reducing the synthesis of PGE2 and thus inhibiting the proliferation of 786-0 cells induced by PGE2.