聚束微波加热逆转MCF-7/ADM细胞对阿霉素耐药性的实验研究

Study on reverse effect of microwave hyperthermia on drug-resistance of MCF-7/ADM cells to ADM

目的耐药性是化疗失败的主要原因之一,克服耐药性的方法之一是使用逆转剂。目前尚无一理想的、可应用于临床的阿霉素(ADM)耐药逆转剂。本研究探讨聚束微波加热对ADM耐药性的逆转作用及其机制。方法体外利用人乳腺癌细胞株MCF-7的ADM耐药模型MCF-7/ADM,采用MTT法检测聚束微波加热对MCF-7/ADM细胞耐药性的逆转作用。用Real-Time PCR测定细胞P-糖蛋白(P-glycoprotein,P-gp)、多药耐药相关蛋白(Multidrug resistance relatedprotein,MRP)的表达水平。高效液相色谱法(HPLC)测定细胞内ADM浓度。结果MCF-7/ADM细胞对ADM的耐药指数为45.5。经聚束微波加热后,ADM对MCF-7/ADM的半数抑制浓度(IC_(50))由(60.56±2.38)ug/ml下降至(22.86±2.76)ug/ml,逆转倍数为2.64倍。Real-Time PCR检测结果显示,MCF-7/ADM细胞的MRP与P-gp mRNA表达水平均明显高于MCF-7细胞,经聚束微波加热后,MCF-7/ADM细胞胞内的MRP与P-gp mRNA表达水平均明显下降。HPLC法测定细胞内ADM含量的结果显示,经聚束微波加热处理后,MCF-7/ADM细胞内ADM的含量明显增加。结论聚束微波加热能逆转MCF-7/ADM对ADM的耐药性,聚束微波加热逆转ADM耐药性的机制可能是减少MCF-7/ADM细胞内MRP与P-gp mRNA的表达水平,从而增加了MCF-7/ADM细胞内ADM的蓄积。

Objective Muhidrug resistance is one of the main causes of treatment failure of chemotherapy. Reversal agents may be used clinically. This study was to evaluate the reverse effect of microwave hyperthermia on drug-resistance of MCF-7/ ADM to adriamycinum （ADM） cells ,and to explore its mechanisms. Methods Breast cell line MCF-7 and its ADM- resistance cell line MCF-7/ADM were treated with ADM and microwave hyperthermia. Reverse effect of microwavehyperthermia on drugresistance of MCF-7/ADM to ADM was tested by MTT assay. The levels of cellular muhidrug resistance related protein （MRP） and P-glycoprotein（P-gp） were detected by Real-Time PCR. The intracellular concentration of ADM was measured by high performance liquid chromatography. Results The resistance index of MCF-7/ADM cells to ADM was 45.5. After microwave hyperthermia, the 50% inhibitory eoncentration（IC50） of ADM to MCF-7/ADM cells reduced by 2. 64 folds from （ 60. 56 ± 2.38 ） ug/ ml to （ 22. 86 ± 2. 76） ug/ml. Protein levels of MRP and P-gp were higher in MCF-7/ADM cells than that in MCF-7 ceils, and they were markedly decreased in MCF-7/ADM cells after microwave hyperthermia. The concentration of ADM in MCF-7/ADM cells was significantly increased after microwave hyperthermia. Conclusion Microwave hyperthermia may reverse drug-resistance of MCF-7/ADM cells to ADM through down-regulating MRP and P-gp and increasing intracellular cumulation of ADM.