COX-2抑制剂塞来昔布对诱导性肝癌Bax、Bcl-2表达影响的实验研究

Experimental study on the expression of Bax and Bcl-2 of the inducing liver cancer by taking COX-2 inhibitor Celecoxib

目的探讨选择性COX-2抑制剂—塞来昔布对诱导性肝癌细胞凋亡基因Bax、Bcl-2表达的影响及其可能的机制。方法将25只雄性Wister大鼠随机分为对照组(n=5)、模型组(n=10)和塞来昔布组(n=10)。模型组和塞来昔布组大鼠均每周一次腹腔注射二乙基亚硝胺,同时塞来昔布组每天给与塞来昔布溶液灌胃,模型组每天给与相同体积的生理盐水灌胃,对照组不做任何处理。20周后行MRI扫描后处死大鼠,取大鼠肝组织行HE染色、免疫组化检测和Western blot检测。结果1)模型组大鼠存活率为40%(4/10),塞来昔布组大鼠存活率为70%(7/10);2)MRI平扫显示模型组肝脏肿瘤直径为(1.064±0.441)cm,塞来昔布组大鼠肝脏肿瘤直径为(0.415±0.154)cm(P<0.05),另有3只为重度肝硬化;3)免疫组化结果显示,正常组大鼠肝组织中COX-2、Bcl-2阳性细胞数(48.352±25.300)个/mm^2、(314.286±78.323)个/mm^2明显少于模型组(970.696±138.246)个/mm^2、(953.686±69.910)个/mm^2,而Bax阳性细胞数则降低(956.040±61.381)个/mm^2 VS(681.319±50.600)。应用塞来昔布后,COX-2、Bcl-2阳性细胞数明显降低(513.736±127.309)个/mm^2、(703.300±56.033)个/mm^2,Bax阳性细胞数则升高(767.399±53.120)个/mm^2,差异具有统计学意义(P<0.05)。Western blot结果表明,正常组大鼠肝组织中COX-2、Bcl-2蛋白相对表达量(0.089±0.042)、(0.181±0.043)明显低于模型组(0.663±0.102)、(0.617±0.069),而Bax蛋白相对表达量则降低(0.768±0.180)VS(0.328±0.034)。应用塞来昔布后,COX-2、Bcl-2蛋白相对表达量明显降低(0.333±0.120)、(0.411±0.075),而Bax蛋白相对表达量明显升高(0.428±0.027),差异均有统计学意义(P<0.05)。结论塞来昔布可以通过降低Bcl-2的蛋白表达,增加Bax的蛋白表达抑制肝癌的生成和促进HCC细胞的凋亡。

Objective To evaluate the effect of celecoxib,a selective COX-2 inhibitor,on the expression of apoptosis gene Bax,Bcl-2 in induced hepatoma cells and to explore the underlying mechanism.Methods 25 Wister rats were randomly divided into control group(n=5),model group(n=10)and celecoxib group(n=10).The rats in model and celecoxib group were treated with diethylnitrosamine(DEN)solution by intraperitoneal injection once a week.Intragastric administration was performed in celecoxib group with celecoxib solution once a day,so was the saline in the model group with the same volume.The MRI scan was performed after 20 weeks.After the examination,all the rats were killed for pathological and immunological investigation.Results 1)The survival rate of the model group was lower than that of the celecoxib group(40%VS 70%);2)MRI imaging demonstrated all rats in model group had larger tumors(1.064±0.441)cm in liver compared with four rats in celecoxib group(0.415±0.154)cm,while the other three in celecoxib group had severe cirrhosis;3)Immunohistochemical results showed that the number of COX-2,Bcl-2 positive cells in control group(48.352±25.300)/mm^2,(314.286±78.323)/mm^2 were significantly lower than those in model group(970.696±138.246)/mm^2,(953.686±69.910)/mm^2),the number of Bax positive cells(956.040±61.381)/mm^2 were significantly higher than those in model group(681.319±50.600)/mm^2.After treatment of celecoxib,there were less COX-2,Bcl-2 positive cells(513.736±127.309)/mm^2,(703.300±56.033)/mm^2 and more Bax positive cells(767.399±53.120)/mm^2.The results of western blot showed that the expression of COX-2 and Bcl-2 protein in the liver of the model group(0.663±0.102),(0.617±0.069)was significantly increased compared with control group(0.089±0.042),(0.181±0.043),and the protein expression of Bax was remarkably decreased(0.768±0.180)VS(0.328±0.034)(P<0.05).After treatment of celecoxib for 20 weeks,the expression of COX-2,Bcl-2 in celecoxib group(0.333±0.120),(0.411±0.075)was significantly lower than that in model group,while the expression of Bax was higher(0.428±0.027)(P<0.05).Conclusion Celecoxib could upregulate the expression of Bax and suppress the expression of Bcl-2,which contributes to its ability to anti-apoptosis activity and inhibit hepatocarcinogenesis.