乳腺癌细胞耐药机理及药物逆转的实验研究

Studies on abnormality of cell cycle control of drug-resistant hepatic carcinoma cells and its reversion

目的:探讨乳腺癌早期耐药的机理,并寻求药物耐药逆转的方法。方法:采用流式细胞术检测经低浓度的阿霉素处理后的乳腺癌细胞系MCF7的多药耐药蛋白(MRP)和P糖蛋白(Pgp)表达,探讨耐药发生机制。用MTT比色法检测利多卡因与抗肿瘤药物合用后对抗肿瘤药物的增敏作用。结果:经低浓度阿霉素处理后,MRP表达明显增加,并随时间延长而进一步增加,而Pgp表达无明显增高。利多卡因在本身没有毒性的浓度下(2 mg/m l),与3种化疗药物合用后降低了3种化疗药物的半数抑制浓度,单用药物分别为(76.3±3.63)mg/L、(7.9±1.2)mg/L、(15.6±1.1)mg/L,合用分别为(10.5±2.9)mg/L、(1.97±0.62)mg/L、(3.32±0.8)mg/L,差异显著(P<0.01)。结论:MRP在肿瘤细胞早期耐药性起主要作用。利多卡因作为钙调蛋白阻制剂,在体外能有效逆转MRP引起的多药耐药,为进一步应用于临床提供理论依据。

Objective： To study the mechanism of anti - drug breast carcinoma and to explore the method of reversing drug - resistant. Methods： The multi - drug resistance - associated protein （MRP）, P glucose protein （Pgp） expressionof cell cycle during the process of drug resistance in hepatic carcinoma MCF7 cell treated with low concentration of adriamycin were detected by flowcytometry. MTT method were used to study the sensitivity of the three anti - cancer drugs including 5 - Fu, MMC and CDDP on the liver tumor cell line MCF7 and the increased sensitivity of the three anti - cancer drugs by Lidocaine. Results： Treatment of MCF7 cells with adriamycin at a final concentration of 0.05 μg/ml resulted in progressive decrease in ceils in G1 phase and increase in cells in S phase of the cell cycle. The expression of MRP expression was significantly increased in a time - dependent manner, and was positively correlated with changes in S phase of the cell cycle. MCF7 were sensitive to all three anti - cancer drugs for the large dose of the three drugs. The IC50 decreased when the three drugs combined with Lidocaine. IC50 were （76.3±3.63）, （7.9±1.2）, （15.6±1.1） mg/L respectively when using anti - cancer drugs alone compared with （10.5±2.9）, （1.9±0.62）, （3.37±0. 8） mg/L respectivdy when adding Lidocaine in advance （P 〈 0.01）. Conclusion： MRP expression may play a major role in the development of resistance to adriamycin. MCF7 is sensitive to all three anti - cancer drugs at large dose. Lidocaine has increased sensitivity to three anti - cancer drugs.