汉防己甲素、托瑞米芬及其联合应用逆转K562/A02细胞多药耐药的研究

本研究探讨汉防己甲素（Tet）、雌激素受体抑制剂托瑞米芬（Tor）及其联合应用对K562/A02细胞多药耐药的逆转作用。采用噻唑蓝法（MTT）测定阿霉素（ADR）的半数抑制量,RT-PCR法检测MDR1基因mRNA表达水平,FCM检测P-gp的表达和细胞内ADR浓度。结果表明：ADR对K562/A02和K562细胞的IC50分别为57.43和1.16mg/L,Tet（1μmol/L）和Tor（2.5μmol/L）单用及两药联用处理K562/A02细胞时,ADR的IC50值分别为14.12,20.74和9.14mg/L。Tet及Tor单独作用后耐药株MDR1 mRNA下调微弱,联合用药下调效果明显。Tet及Tor均可降低P-gp蛋白的表达,且具有协同作用。Tet及Tor作用后细胞内ADR浓度增加,两药联合作用时效果增强。结论：Tet及Tor均可逆转K562/A02细胞多药耐药,联合作用时效果增强。

Effect of Tetrandrine,Toremifene and Their Combination on the Reversion of Multidrug Resistance of K562/A02 Cell Line

This study was aimed to investigate the reversible effect of tetrandrine, toremifene and their combination on multidrug resistance of K562/A02 cell line. The IC(50) (the concentration causing 50% inhibition of cell growth) of adriamycin (ADR) were assayed by MTT method, the expression of MDR1 mRNA was measured by RT-PCR, the concentration of p-glycoprotein (P-gp) and intracellular ADR were detected by flow cytometry. The results showed that the IC(50) of ADR on K562/A02 and K562 cells were 57.43 and 1.16 mg/L, respectively. The IC(50) of ADR on K562/A02 cells after treatment with tetrandrine, toremifene and both combination were 14.12, 20.74 and 9.14 mg/L respectively, but both drugs did not influence the IC(50) of ADR on K562 cells. Pretreating K562/A02 cells with toremifene (2.5 micromol/L), tetrandrine (1 micromol/L) or both for 72 hours partially restored the sensitivity of K562/A02 cells to ADR. Tetrandrine and toremifene (alone or combination) elevated the ADR concentration in K562/A02, down regulated the expressions of P-gp and MDR1 mRNA. It is concluded that multidrug resistance of K562/A02 cells can be partially reversed by tetrandrine or toremifene, the combination of both drugs shows a higher synergistic reversal effect.