汉防己丙素干预亚硝基胺致大鼠膀胱癌的作用及机制研究

Effect and mechanism of cyclanoline on nitrosamine-induced bladder cancer in rats

目的探讨汉防己丙素(Cyc)干预亚硝基胺(BBN)致大鼠膀胱癌的作用及机制。方法雄性SD大鼠随机分为对照组,模型组,Cyc低、高剂量(20、40 mg/kg)组,顺铂(5 mg/kg)组。大鼠ig 0.5 mL BBN(0.4 kg/L),2次/周,连续8周,建立膀胱癌模型。除对照组和模型组ip生理盐水外,其余各组ip设定剂量的药物,1次/d,连续8周。实验结束后,收集大鼠膀胱组织;通过HE染色观察大鼠膀胱组织病理变化;通过免疫组化法检测膀胱组织MMP9、Ki67的表达;通过免疫印迹法检测膀胱组织KLF4、p21、CyclinD1、E-cadherin、N-cadherin、Vimentin、Wnt、β-catenin蛋白的表达。结果与模型组相比,Cyc可有效抑制膀胱炎细胞浸润、促进癌细胞出现不同程度退变、减少质比例;显著下调膀胱组织MMP9、Ki67的表达(P<0.05、0.01);显著上调膀胱癌组织中KLF4、p21、E-cadherin的表达(P<0.05、0.01);显著下调CyclinD1、Wnt、β-catenin、N-cadherin、Vimentin的表达(P<0.05、0.01)。结论Cyc通过促进KLF4表达、阻断Wnt/β-catenin信号传导、抑制膀胱癌细胞上皮细胞-间充质转化进程,进而抑制膀胱癌细胞迁移与侵袭能力;同时通过上调KLF4水平,调控下游因子p21、CyclinD1表达,影响膀胱癌细胞的增殖能力,从而延缓BBN诱导的大鼠膀胱癌的病理进程。

Objective To investigate the effect and mechanism of cyclanoline on nitrosamine(BBN)-induced bladder cancer in rats.Methods Male SD rats were randomly divided into control group,model group,Cyc-low dose(20 mg/kg)group,Cyc-high dose(40 mg/kg)group and cisplatin(5 mg/kg)group.Rats were intragastrically administered with 0.5 mL BBN(0.4 kg/L,twice a week for 8 weeks)to establish bladder cancer model.In addition to control and model group given with normal saline,the other groups were intraperitoneally injected with drugs(once a day for 8 weeks).The bladder tissue was collected after experiment.HE staining was used to investigate the histopathological changes of the bladder in rats.The expressions of MMP9 and Ki67 were observed by immunohistochemistry method,and the expressions of KLF4,p21,CyclinD1,E-cadherin,N-cadherin,Vimentin,Wnt,β-catenin in the bladder tissues were detected by Western bloting.Results Compared with the model group,cyclanoline effectively inhibited the infiltration of cystitis cells,promoted the degeneration of cancer cells,and reduced the proportion of cytoplasm.Cyclanoline significantly decreased the expressions of MMP9 and Ki67(P<0.05,0.01),up-regulated the expressions of KLF4,p21 and E-cadherin(P<0.05,0.01),down-regulated the expressions of CyclinD1,Wnt,β-catenin,N-cadherin and Vimentin in bladder cancer tissues(P<0.05,0.01).Conclusion Cyclanoline promotes the expression of KLF4,inhibits Wnt/β-catenin signaling transduction and the epithelial cell-mesenchymal transition of bladder cancer cells,thereby inhibiting the migration and invasion of bladder cancer cells.Meanwhile,cyclanoline regulates the expressions of p21 and CyclinD1 by up-regulating KLF4,affects the proliferation of bladder cancer cells,and thereby delays the pathological process of BBN-induced bladder cancer in rats.