The Expression Of MDR1 And BCRP In Breast Cancer Cell Line MCF-7 After Chemotherapeutical Drug Intervention And Its Value In Clinical Practice

OBJECTIVE To evaluate the correlativity between Adriamycin, Epirubicin, Paclitaxel, Docetaxel intervention and the level of MDR1 and BCRP gene in vitro and to discuss the probable mechanisms which joining in the multidrug resistance developing.METHODS 1. To culture the Breast Cancer Cell Line MCF-7 in vitro and intervene it with Adriamycin, Epirubicin, Paclitaxel, Docetaxel. 2. RT-PCR and fluorescent quantitative RT-PCR were adopted to detect the expression of MDR1 and BCRP in breast cancer cell line MCF-7 after chemotherapeutical drug intervention and in the tissues from clinical surgery which had been selected on he basis of the results of in vitro chemosensitivity testing. 3. To measure the expression of CD44 and CD24 of MCF–7 breast cancer cell line in diverse incubation circumstance, observate the proportion of breast cancer stem cell in diverse environment and to measure the expression of MDR1 in different subtypes of breast cancer cell line MCF–7.RESULTS There are obvious dose-effect relationship between Adriamycin, Epirubicin and the level of MDR1, but the relationship between Adriamycin, Epirubicin and the level of BCRP and the relationship between Paclitaxel, Docetaxel and the level of MDR1 and BCRP are still vague. Besides, the proporation of breast cancer stem cells from breast cancer cell line MCF–7 markedly increases after chemotherapy. And the proporation and the expression of MDR1 in CD44~+CD24~-and CD44~+CD24~+ cells of MCF-7 breast cancer cell line is increasing comparatively with the proporation of CD44~+CD24~-cells.CONCLUSION The results confirm that Adriamycin and Epirubicin are the specific substrates of p-gp which is encoded by MDR1 gene. And it seems that the theories of selection and adaptation are both joining in the developing of multidrug resistance.