人乳腺癌多耐药细胞株中ALDH1,P-gp及CD44v6的表达研究

目的:比较人乳腺癌亲代敏感株MCF-7和多耐药细胞株MCF-7/A中ALDH1,P-gp及CD44v6的表达差异,探讨多耐药与侵袭转移作用机制。方法:以阿霉素低浓度加量持续诱导法,建立人乳腺癌多耐药细胞模型株MCF-7/A,用ALDEFLUOR分析法检测乳腺癌干细胞功能性标志物ALDH1阳性细胞在亲代敏感株MCF-7与多耐药细胞株MCF-7/A中所占比例,Transwell侵袭实验论证乳腺癌胞耐药是否伴随相应侵袭转移能力的改变,免疫细胞化学染色及荧光定量PCR分析亲代敏感株MCF-7与多耐药细胞株MCF-7/A中MDR1(P-gp)和CD44V6的表达变化。结果:耐药细胞株MCF-7/A较亲代敏感株ALDH1阳性细胞比例数明显增高;耐药细胞株MCF-7/A穿膜细胞数明显多于敏感细胞株MCF-7;耐药细胞株MCF-7/A中P-gp和CD44v6表达均明显高于亲代敏感细胞株。结论:乳腺癌的多耐药不仅包含获得性耐药细胞比例增加,同时伴有肿瘤干细胞的富集造成的内在性耐药增加,耐药的乳腺癌细胞伴有侵袭能力增强。

Expression analysis of ALDH1,P-gp and CD44V6 in multidrug-resistant breast cancer cell line

Objective:To explore the mechanism of multi-drug resistance and cancer invasion/metastasis by comparing the expression differences of ALDH1,P-gp and CD44V6 in MCF-7 cell line and MCF-7/A resistance cell line.Methods: A new multi-drug resistant breast cancer cell line MCF-7/A was established by exposing in stepwise increasing concentration of adriamycin.The ALDH1-positive population of cancer stem cells was detected by ALDEFLUOR assay.Transwell chamber cell invasion assay was employed to verify whether multi-drug resistant breast cancer cells associated with the changes of cell invasion.MDR1 and CD44v6 were detected through immuno-cytochemistry staining and fluorescence quantitative PCR.Results: A new adriamycin-resistant breast cancer cell line MCF-7/A was successfully induced.The resistance index was 74.ALDEFLUOR assay results showed the proportion of ALDH1-positive cells significantly increased.Comparing with the parental sensitive cell line MCF-7,the expression of MDR1(P-gp) and CD44v6 were significantly upregulated in the drug resistant cell line MCF-7/A.Transwell invasion assay confirmed that the number of cells through the basement membrane in the resistant cell line MCF-7/A increased obviously comparing with the sensitive cell line MCF-7.Conclusion: Multi-drug resistance of breast cancer includes the enrichment of cancer stem cells.The invasion ability of breast cancer cells enhanced with the development of drug-resistance.