乙酰阿地咪逆转肿瘤细胞多药耐药及其机制的研究

Reversal Effect and Its Mechanism of(-)-5-N-Acetylardeemin on Adriamycin Resistance in Multidrug-resistant Cancer Cells A549/Adr and MCF-7/Adr

目的探讨乙酰阿地咪体外逆转多药耐药细胞株人乳腺癌耐阿霉素细胞(MCF-7/Adr)以及人非小细胞肺癌耐阿霉素细胞(A549/Adr)的耐药作用及其作用机理。方法采用乳酸脱氢酶释放法检测乙酰阿地咪与阿霉素共处理MCF-7、A549、MCF-7/Adr以及A549/Adr细胞的细胞毒作用,以观察增敏和逆转耐药作用;用全功能酶标仪测定乙酰阿地咪与阿霉素共同处理MCF-7/Adr和A549/Adr细胞后细胞内积累阿霉素的荧光强度,并采用Western blot检测细胞膜上多药耐药蛋白P-糖蛋白(P-gp)表达的变化。结果乙酰阿地咪能降低MCF-7/Adr和A549/Adr对阿霉素的耐药性,10μmol/L的乙酰阿地咪对MCF-7/Adr和A549/Adr逆转倍数分别为10.8、20.1,其逆转作用与乙酰阿地咪呈剂量依赖关系,且对MCF-7和A549细胞也具有增敏作用;随着乙酰阿地咪浓度的增加,MCF-7/Adr和A549/Adr细胞内积累阿霉素的荧光强度增加率增加,呈剂量依赖性;经乙酰阿地咪处理的MCF-7/Adr和A549/Adr细胞P-gp蛋白表达水平降低,且降低水平随乙酰阿地咪浓度增加而更明显。结论乙酰阿地咪可显著逆转肿瘤细胞的多药耐药性,其机理与抑制多药耐药蛋白P-gp的表达有关,提示乙酰阿地咪具有潜在的克服肿瘤化疗中多药耐药现象的应用价值。

Objective To explore the reversal effect of（-）-5-N-acetylardeemin on adriamycin resistance in multidrug-resistant cancer cells including human breast cancer cells MCF-7/Adr and human non-small cell lung cancer cells A549/Adr in vitro.Methods The multidrug-resistant cancer cells MCF-7/Adr,A549/Adr and their respective parental cells were treated with different concentrations of（-）-5-N-acetylardeemin and adriamycin individually or in combination.Cell death was detected based on the release of lactate dehydrogenase（LDH）using a cytotoxicity detection kit.Intracellular accumulation of adriamycin was measured by the detection of fluorescence intensity of cell lysates using microplate reader.The expression of P-glycoprotein（P-gp）was evaluated by Western blot.Results（-）-5-N-acetylardeemin significantly reversed the adriamycin resistance in MCF-7/Adr and A549/Adr in a dose-dependent manner,and the reversal folds were 10.8in MCF-7/Adr cells and 20.1in A549/Adr cells with the treatment of 10μmol/L（-）-5-N-acetylardeemin.（-）-5-N-acetylardeemin also enhanced the sensitivity of parental MCF-7and A549 cells to adriamycin.The fluorescence intensity in both MCF-7/Adr and A549/Adr cells,which reflected the intracellular accumulation of adriamycin, were significantly enhanced by（-）-5-Nacetylardeemin in a dose-dependent manner.The expressions of P-gp in MCF-7/Adr and A549/Adr cells were significantly inhibited by（-）-5-N-acetylardeemin.Conclusion（-）-5-N-acetylardeemin could reverse the multidrug resistance in cancer cells through inhibiting the expression of P-gp and enhancing the intracellular accumulation of cytotoxic drug.