获得性他莫昔芬耐受MCF-7细胞膜受体的变化及格列卫的逆转作用

目的 :探讨耐受他莫昔芬 (TAM)的MCF 7细胞膜受体等的变化及格列卫对耐药的逆转作用。方法 :MTT法检测TAM对E2 、EGF、Insulin刺激的MCF 7增殖的抑制作用 ;流式细胞术检测与10 - 7mol/LTAM孵育 8周、16周后的MCF 7细胞ER、PR、EGFR及VEGF的变化 ,MTT法检测格列卫对耐药的逆转作用。结果 :TAM抑制E2 、EGF、Insulin刺激的MCF 7增殖 ;耐受TAM的MCF 7ER、PR表达率由父代的 93%、91%下降为 4 1%、36 % ,EGFR由 10 %上升为 39% ,VEGF由 36 %下降至 30 % ,对EGF刺激的增殖更敏感 ,格列卫可增强TAM的生长抑制作用。结论 :耐受TAM的MCF 7细胞ER、PR表达下降 ,EGFR表达升高 ,EGF/EGFR刺激的细胞增殖作用增强 ,格列卫可能作为对TAM获得性耐药后逆转用药方案或贯序用药方案。

Acquired Tamoxifen Resistance Leading to an Altered Cellular Phenotype in MCF-7 and the Experimental Reversal Effect on Antiestrogen-resistance of Gleevec

Objective To study the alteration of membrane receptor in acquired Tamoxifen resistant MCF 7 cell line(MCF 7/TAM) and the experimental reversal effect on antiestrogen resistance of Gleevec.Methods MTT assay was performed to evaluate the growth enhancing effect of E 2,Insulin and EGF on MCF 7 respectively,as well as the reversal effect on antiestrogen resistance of Gleevec.The percentage of ER,PR,EGFR and VEGF expressing were detected by flow cytometry.Results TAM restrained E 2,Insulin and EGF depending on cell proliferation.The percentage of ER and PR in the MCF 7/TAM were down regulated from 93%,91% to 41%,36% respectively.However,the EGFR was up regulated from 10% to 39%,VEGF slightly declined,compared with the parental line.The MCF 7/TAM had an enhanced EGFR signaling,and certainly sensitise to the EGF stimulated cell proliferation and Gleevec induced growth inhibition.Conclusions The MCF 7/TAM resulted in an enhanced EGFR signaling phenotype.Gleevec may be administrated as a antiestrogen resistant reversal agent or a synergistic agent in an acquired Tamoxifen resistant breast cancer.