EGCG对裸鼠移植瘤中人口腔表皮样癌耐药细胞凋亡的影响  

A STUDY ON THE APOPTOSIS OF KBV200 ADMINISTRATED WITH(-)-EPIGALLOCATECHIN-3-GALLATE AND VINCRISTINE IN VIVO AND ITS MECHANISM

作　　者：林晓贞[1] 梁钢[1] 唐安洲[2] 黎莉[1] 

机构地区：[1]广西医科大学药理学教研室,南宁530021 [2]广西医科大学第一附属医院耳鼻咽喉科

出　　处：《广西医科大学学报》2006年第2期195-199,共5页Journal of Guangxi Medical University

基　　金：广西科技厅自然科学基金资助项目(桂科自No.0004302)

摘　　要：目的:探讨表没食子儿茶素没食子酸酯(EGCG)增敏长春新碱(VCR)对人口腔表皮样癌多药耐药细胞株KBV200裸鼠移植瘤的抑瘤作用及与瘤细胞凋亡的关系。方法:采用KBV200接种于裸鼠皮下,建立耐药肿瘤模型;2周后,EGCG和VCR腹腔注射,联合处理2周;免疫组化法检测瘤组织Bcl-2,Bax的表达;TUNEL法检测细胞凋亡;流式细胞仪进行细胞周期分析;透射电镜观察瘤组织细胞超微结构的改变。结果:EGCG联合VCR处理治疗后瘤重、肿瘤相对体积明显低于对照组和VCR组(P<0.05),且与EGCG的剂量呈正相关;低、中、高EGCG联合VCR组Bcl-2的表达明显低于VCR组(P<0.01);低、中、高EGCG联合VCR组Bax蛋白的表达明显高于VCR组(P<0.01);TUNEL法低、中、高EGCG联合VCR组凋亡指数明显高于VCR组,与EGCG呈剂量依赖关系;流式细胞技术显示低、中、高EGCG联合VCR组G2/M期细胞高于VCR组(P<0.01);电镜下三个联合用药组瘤组织中可见较多典型的细胞凋亡的形态学表现。结论:EGCG在体内具有增敏VCR对KBV200移植瘤的杀伤作用。机制可能是通过下调Bcl-2蛋白,上调Bax蛋白的表达,从而促进肿瘤细胞的凋亡。Abstract Objective：To investigate the effect of （-）-Epigallocatechin-3-gallate administrated with vincristine on experimental chemotherapy against xenografts derived from Human oral epidermoid carcinoma multi-drug resistant human cell line KBV200 and its potential mechanism. Methods： Models of KBV200 xenograft in nude mice were established to investigate the anti-tumor effect of EGCG. Nude mice with KBV200 xenograft were treated with VCR and EGCG of intraperitoneal injection for two weeks. Expression of Bcl- 2 and Bax of xenografts were investigated by immunohistochemistry. The apoptosis of KBV200 cells was observed with TUNUL and FACS with PI-staining. The ultra micro-structured changes of KBV200 cells were observed by transmission e｜ectron microscope. Result：Tumor inhibition was observed in the KBV200 xenografts following a 14-day treatment with 10 ,20 and 40 mg/kg of EGCG combined with VCR, with total growth inhibition of 69.1%,72.8%,76. 1%, respectively. The expression of Bcl-2 was lower（ P 〈0. 01）and the expression of Bax of the three co-administration group was higher（ P 〈0.01）than that of VCR group. The rate of cellapoptosis exhibiting as （VE low group：45. 1%, VE mid group：52.3%, VE high group：58.1%） , was higher than that of VCR group（32.5%） （P〈0.01）. VCR arrests cells in G2/M phase of the cell cycle when co-admnistrated with EGCG in a concentration-dependent manner. Electron microscopy indicated the apoptosis of tumor cells with marginal nuclei, chromatin condensation and nuclei fragmentation,and apoptotic bodies were observed. Conclusion： KBV200 xenografts were sensitive to the treatment of VCR when co-administrated with EGCG. The mechanism of overcoming MDR was associated with down-regulating the expression of Bcl-2 and upregulating the expression of Bax to promote apoptosis of KBV200.

关 键 词：多药耐药 P糖蛋白 凋亡 耐药逆转剂 口腔癌 

分 类 号：R739.85[医药卫生—肿瘤]