摘要
[目的]探讨表没食子儿茶素没食子酸酯[(-)epigallocatechin鄄3鄄gallate,EGCG]对人白血病细胞K562/A02多药耐药性的逆转作用及相关机制。[方法]采用MTT法确定EGCG的非细胞毒性剂量,以及对K562/A02细胞药物敏感性的影响。以流式细胞术测定EGCG作用前后细胞内阿霉素浓度的变化;同时采用半定量逆转录聚合酶链反应(RT鄄PCR)及Westernblot方法分别检测经典多药耐药基因(MDR1)mRNA及其产物P糖蛋白的表达。[结果]EGCG在低于103.2μmol/L时对K562/A02细胞的生长抑制率小于10%。40μmol/L、60μmol/L及80μmol/LEGCG均可增加K562/A02细胞对阿霉素的敏感性,使阿霉素对K562/A02细胞的IC50由原来的113.34μg/ml降低至9.66μg/ml、7.67μg/ml和4.68μg/ml,其逆转倍数分别为11.73、14.77和24.23倍。流式细胞术结果表明EGCG可增加细胞内阿霉素浓度,并呈剂量依赖性。RT鄄PCR及Westernblot结果显示不同浓度的EGCG均可抑制K562/A02细胞MDR1mRNA及P糖蛋白的表达。[结论]EGCG可部分逆转人白血病细胞K562/A02对阿霉素的耐药性,其逆转机制与增加细胞内化疗药物浓度、抑制经典多药耐药基因MDR1mRNA及其产物P糖蛋白的表达有关。
To investigate the reversal effect of (-) epigallocatechin-3-gallate (EGCG) on human leukemic K562/A02 cell line and its possible mechanisms. Cytotoxicity of EGCG and its sensibility to doxorubicin (DOX) in K562/A02 cell line, a DOX-resistance cell line of human leukemia, were evaluated by MTT assay. The intracellular concentration of DOX was detected by flow cytometry. Before and after EGCG was given, the expressions of MDR1 mRNA and P-glycoprotein were detected by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot respectively. The 10% inhibition concentration (IC10) of EGCG to K562/A02 cell line was 103.2μmol/L, so 40μmol/L, 60μmol/L and 80μmol/L EGCG were used to detect the reversal effect of multidrug resistance. The IC50 for DOX was 113.34μg/ml and 1.12μg/ml for K562/A02 and K562/S cell lines respectively. The resistance factor was 101.2-fold. EGCG could increase the drug susceptibility of K562/A02 cells to DOX, and at concentrations of 40μmol/L, 60μmol/L and 80μmol/L, the IC50 for DOX decreased to 9.66, 7.67 and 4.68μg/ml respectively, and the modulating factors were 11.73-, 14.77- and 24.23-fold, respectively. Meanwhile, EGCG at different concentrations could significantly increase the intracellular accumulation of DOX in K562/A02 cell line and this effect was in a dose-dependent manner. The expressions of MDR1 mRNA and P-glycoprotein in K562/A02 cells incubated with EGCG were decreased when detected by RT-PCR and Western blot. [Conclusion] EGCG could partially reverse the multidrug resistance of K562/A02 cells in vitro. Furthermore, the reversal effect may be due to the increase of intracellular accumulation of chemotherapeutic drugs and the decrease of the expressions of MDR1 mRNA and P-glycoprotein.
出处
《肿瘤学杂志》
CAS
2004年第6期389-392,共4页
Journal of Chinese Oncology
关键词
儿茶素
耐药性
P糖蛋白
白血病
catechin
drug resistance
P-glycoprotein
leukemia
