两种儿茶素成分体外逆转人肝癌细胞BEL-7404/ADR多药耐药性

MDR-reversing Effect of Two Components of Catechin on Human Hepatocellular Carcinoma BEL-7404/Adr In Vitro

背景与目的:儿茶素具有多种抗肿瘤的活性,目前,国内外尚未见儿茶素用于肝癌多药耐药性的研究。本研究拟探讨两种儿茶素成分表儿茶素没食子酸酯(epicatechingallate,ECG)和表没食子儿茶素没食子酸酯(epigallocatechingallate,EGCG)体外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ECG、EGCG的细胞毒作用;荧光分光光度法检测细胞内化疗药物的含量;RT-PCR法检测mdr1基因的表达。结果:ECG和EGCG在100mg/L以下剂量时对耐药肝癌细胞株BEL-7404/ADR的抑制率均小于10%,60mg/L的ECG和14mg/L的EGCG分别与0.8mg/L的阿霉素(adriamycin,ADM)合用能使ADM对BEL-7404/ADR的IC50由36mg/L分别下降至2.3mg/L和1.9mg/L,增敏倍数分别为15.8倍和19.2倍,联合用药可使细胞内ADM的浓度由(0.76±0.02)μg/108cells～(2.55±0.17)μg/108cells提高到(2.04±0.07)μg/108cells～(9.28±0.59)μg/108cells(P<0.01),并使mdr1表达与对照组相比分别下降了27.6%及41.3%,逆转肿瘤MDR作用以EGCG为强。结论:EGCG和ECG具有体外逆转人肝癌细胞多药耐药性的作用,可能与下调mdr1表达、增加细胞内化疗药物的积累有关。

BACKGROUND & OBJECTIVE: Catechin is composed of a variety of co mponents,some of which have anti- cancer activity. There was no report on effec t of catechin on the multidrug resistance of hepatocellular carcinoma so far. Th e aim of this study was to investigate the MDR- reversing effect of two compone nts of catechin on human hepatocellular carcinoma BEL- 7404/Adr in vitro and it s potential mechanism. METHODS: MTT was used to test the toxicity of the two com ponents of catechin. The concentration of the drugs inside the cells was determi ned by fluorospectro- photometry and the expression of MDR1 was measured by RT - PCR. RESULTS: The inhibition rates of BEL- 7404/Adr caused by two components of catechin were less than 10% under the dose of 100 mg/L. Epicatechin gallat e (ECG) in 60 mg/L or epigallocatechin gallate (EGCG) in 14 mg/L has slight cyto toxicity, but they could decrease the IC50 of adriamycin (ADM) for BEL- 7404/Ad r from 36 mg/L to 2.3 mg/L or 1.9 mg/L, respectively, and the reversing folds we re 15.8 and 19.2, respectively. The combined administration could increase the c oncentration of ADM in BEL- 7404/Adr cells from 0.76 μ g/108 cells- 2.55 μ g /108 cells to 2.04 μ g/108 cells - 9.28 μ g/108 cells (P< 0.01). The expressi on of MDR1 was down- regulated by 27.6% and 41.3% , respectively. Furthermor e, EGCG is the stronger one. CONCLUSION: ECG and EGCG can reverse the multi- dr ug resistance of human hepatocellular carcinoma in vitro. The possible mechanism is related to down- regulating the expression of MDR1 and raising the concentr ation of drugs inside the cells.