摘要
目的 :探讨表没食子儿茶素没食子酸酯〔(- )epigallocatechin - 3- gallate (EGCG)〕对人白血病细胞K5 6 2 /A0 2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K5 6 2 /A0 2细胞药物敏感性的影响。以流式细胞仪测定细胞内化疗药物浓度的改变 ,同时于逆转前后采用免疫细胞化学方法检测凋亡相关蛋白bcl 2和bax表达水平的变化。结果 :EGCG在低于 10 3.2 μmol/L时对K5 6 2 /A0 2细胞的生长抑制率小于 10 %。 4 0 μmol/L、6 0 μmol/L及 80 μmol/LEGCG均可增加K5 6 2 /A0 2细胞对阿霉素的敏感性 ,使阿霉素对K5 6 2 /A0 2细胞的IC50 由原来的 113.34mg/L降低至9.6 6mg/L、7.6 7mg/L和4 .6 8mg/L ,其逆转倍数分别为 11.73、14 .77和 2 4 .2 3倍。同时 ,不同浓度EGCG均可增加细胞内阿霉素浓度 ,并呈剂量依赖性。在 4 0 μmol/L、6 0 μmol/L及 80 μmol/LEGCG作用后 ,细胞bcl 2和bax的表达水平均增加 ,并且bax/bcl 2比值升高。结论 :EGCG可部分逆转人白血病细胞K5 6 2 /A0 2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 ,升高细胞bax/bcl
Objective:To investigate the reversal effect of (-) epigallocatechin-3-gallate (EGCG) on multidrug resistant cell line K562/A02 and its possible mechanisms.Method:Cytotoxicity of EGCG and the sensibility to doxorubicin(DOX) in K562/A02 cell line, a DOX-resistance cell line of human leukemia, were studied by MTT assay. The concentration of intracellular DOX was detected by flow cytometry. Before and after EGCG was given, the expressions of bcl-2 and bax, both are apoptosis-related proteins, were detected by immunocytochemistry.Result:The 10% inhibition concentration (IC 10) of EGCG to K562/A02 cell line was 103.2 μmol/L, so 40 μmol/L, 60 μmol/L and 80 μmol/L EGCG were used to detecte the reversal effect on multidrug resistance. At all above concentrations, EGCG could effectively increase the sensibility to DOX in K562/A02 cell line. The medium inhibition concentration (IC 50) was obviously reduced from 113.34 mg/L to 9.66 mg/L, 7.67 mg/L and 4.68 mg/L respectively, with a reversal ratio of 11.73, 14.77 and 24.23 as compared with its parental cell line. 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. After 40 μmol/L, 60 μmol/L and 80 μmol/L EGCG were given, the expressions of bcl-2 and bax were increased and the ratio of bax/bcl-2 was also increased significantly.Conclusion:EGCG could partially reverse the DOX resistance of K562/A02 cell line of human leukemia, which might be related to the increase of intracellular DOX concentration and the increase in ratio of bax/bcl-2.
出处
《临床血液学杂志》
CAS
2005年第1期33-36,共4页
Journal of Clinical Hematology
