乌索酸对T细胞淋巴瘤细胞株Hut-78细胞体外增殖的影响及其机制研究

Effect of ursolic acid on proliferation of T lymphoma cell lines Hut-78 cells and its mechanism

目的 探讨乌索酸对T细胞淋巴瘤细胞株Hut-78细胞体外增殖的影响及其作用机制.方法 采用MTT法观察不同浓度（10、20、40、80 μmol/L）乌索酸作用不同时间（4、12、24、48、72 h）对Hut-78细胞增殖的抑制作用,并采用流式细胞术分析其早期凋亡的情况.采用免疫印迹法检测乌索酸作用后Hut-78细胞细胞核因子-κB（NF-κB）p65、p50、p52和p100亚基蛋白,以及caspase-8、3、9蛋白表达变化,采用逆转录PCR法检测血管内皮生长因子（VEGF）和环氧合酶-2（COX-2）mRNA表达水平.结果 与不加药对照组比较,不同浓度的乌索酸作用组Hut-78细胞的增殖均受抑制（P值均＜0.05）;AnnexinⅤ＋/pI-细胞比例均升高（P值均＜0.05）;经10、20、40、80 μmol/L乌索酸处理Hut-78细胞72 h后,Hut-78细胞NF-κBp65、p50蛋白和VEGF、COX-2 mRNA表达水平均下降（P值均＜0.05）,caspase-8、3、9蛋白表达均增加（P值均＜0.05）;NF-κBp100、p52蛋白表达差异均无统计学意义（P值均＞0.05）.上述作用均呈剂量和（或）时间依赖性（P值均＜0.05）.结论 乌索酸抑制Hut-78细胞增殖,作用可能与促其凋亡有关,经过死亡受体和线粒体途径完成;影响NF-κB经典信号路径可能是其机制之一,VEGF和COX-2可能也参与其中.

Objective To investigate the effects ofursolic acid on T cell lymphoma cell lines-Hut-78 cells and its mechanism.Methods Inhibition of Hut-78 cells proliferation by ursolic acid at different concentration （10,20,40 and 80 μmol/L） for different incubation time （4,12,24,48 and 72 h）was examined by MTT method,and early apoptosis by flow cytometry.The protein expressions of p65,p50,p52 and p100,and caspase-8,caspase-3 and caspase-9 were detected by Western blot.VEGF and COX-2 mRNA expressions were measured by reverse transcription polymerase chain reaction （RT-PCR）.Results It was showed that ursolic acid inhibited proliferation of Hut-78 cells （P〈0.05）.Apoptosis of Hut-78 cells was induced by 10,20,40 and 80 μmol/L ursolic acid treatment （P〈0.01）.Likewise,expression of p65 and p50 proteins were down-regulated by ursolic acid treatment （10,20,40 and 80 μmol/L） （P〈0.01）,but there was no significant change in the expression of p52 and p100.Moreover,ursolic acid could up-regulate expression ofcaspase-8,caspase-3 and caspase-9 protein （P〈0.01）.RT-PCR examination showed that VEGF and COX-2 mRNA expression decreased by ursolic acid treatment.Conclusion Inhibition of Hut-78 cells proliferation may be related to ursolic acid induced apoptosis through h death receptors and mitochondrial pathways.NF-κB classical signal pathway may be one of its mechanisms,and VEGF and cox-2 may also be involved.