EGCG逆转人耐药肝癌细胞株多药耐药的体内实验研究

THE MDR-REVERSING EFFECT OF (-)-EPIGALLOCATECHIN-3-GALLATE ON HUMAN HEPATOCELLULAR CARCINOMA BEL-7404/ADR IN VIVO

目的:研究表没食子儿茶素没食子酸酯(EGCG)体内逆转人肝癌细胞多药耐药性的作用及可能的机制。方法:MTT法检测肝癌耐药细胞株BEL-7404/ADR与其亲本细胞BEL-7404耐药倍数,采用BEL-7404/ADR种植于裸鼠皮下,建立肿瘤耐药模型,两周后EGCG灌胃,腹腔注射阿霉素(ADM),联合治疗两周;荧光分光光度法检测瘤体内ADM含量,HE染色观察形态学改变;RT-PCR检测瘤组织mdr1mRNA的表达,免疫组化法检测瘤组织P糖蛋白(P-gp)的表达。结果:低、中、高EGCG联合ADM组肿瘤生长速度明显低于ADM组,瘤重明显低于阿霉素组;EGCG联合ADM可增加瘤体内ADM的含量(P<0·01);三个EGCG联合ADM组与阿霉素组相比HE病理图片显示肿瘤组织纤维包裹,炎细胞浸润;mdr1mRNA和P-gp的表达明显低于对照组和阿霉素组(P<0·01)。结论:EGCG在体内具有逆转BEL-7404/ADR的耐药作用,机制可能是EGCG下调了肝癌细胞mdr1基因的表达,使P-gp的表达降低,瘤组织内药量增高。

Objective.This study aims to investigate the multi-drug resistance reversal effects of （-）-Epigallocatechin-3-gallate （EGCG） on xenografts derived from multi-drug resistant hepatocellular carcinoma （HCC） cell line BEL-7404/ADR and the possible mechanism. Methods：Cell survival rate was determined by MTT assay. The models of BEL-7404/ADR xenograft in nude mice were established and received the desired drug and dosage. Morphology of xenografts were investigated by HE staining. ADM concentration in the tumors was determined with a fluorescence spectrophotometer. The expressions of mdrl and P-glycoprotein（P-gp） were observed with reverse transcriptase PCR and immunohistochemistry respectively. Resalt： In the models of BEL-7404/ADR xenografts, the growth rates of the three co-adminstration group were lower than that of ADM group. EGCG of 40 mg/kg,80 mg/kg,160 mg/kg,exhibited （56.7%,62.2%, 65.1%） in inhibiting the growth of xenografts, respectively. ADM Concentration in the tumors of the three co-administration groups were higher than ADM group. The combination of EGCG and ADM reduced the expression of mdrl and P-gp（ P 〈0.01） . Conclusion： EGCG can reverse the multi-drug resistance of human HCC in vivo. The mechanism is probably associated with down-regulating the expression of mdrl and P-gp.