摘要
目的:探讨原癌基因c-Src在乳腺癌抗雌激素受体α(estrogen receptor,ERα)治疗过程中的变化及其耐药机制。方法:用雌激素受体阻滞剂三苯氧胺(tamoxifen,TAM)长期处理ERα阳性的MCF-7细胞建立TAM耐药细胞(TAM-R)。用免疫印迹实验检测c-Src、ERα、表皮生长因子受体(epidermal growth factor receptor,EGFR)在耐药细胞上的表达,用免疫沉淀法检测这些分子间的相互作用,并用c-Src抑制剂PP2阻断其磷酸化,观察其对耐药的逆转作用。结果:与原生的MCF-7细胞相比,c-Src、ERα、EGFR在TAM-R上的表达量没有改变,但是,c-Src磷酸化水平在耐药细胞上表达明显增高。并且在耐药细胞上,ERα与EGFR之间的相互结合明显增高,PP2可以明显阻断两分子间的相互作用。更重要的是,经PP2处理后耐药细胞的生长可再次被TAM抑制,即PP2可以逆转耐药细胞的耐药性。结论:c-Src是介导ERα与EGFR之间相互作用的关键分子,阻断这种相互作用可以重新获得对TAM治疗的敏感性,提示c-Src抑制剂可以和TAM交替使用来提高乳腺癌的治疗效果。
Objective:To investigate the function of oncogene c-Src in the process of anti-estrogen receptor α therapy and how it mediates the resistance in estrogen receptor(ER)-positive breast cancer cells. Methods:Wild-type MCF-7 cells were long-term treated with tamoxifen(TAM)and established tamoxifen resistant cells(TAM-R). The expression of c-Src,ERα,and epithelial growth factor receptor(EGFR)was detected by immunoblotting. The interactions between ERα and EGFR were measured by immunoprecipitation.The c-Src inhibitor PP2 was used to block the tyrosine kinase activity of c-Src. Results:Compared with wild-type MCF-7 cells,expression levels of ERα,EGFR,and c-Src were not altered in TAM-R cells. However,the phosphorylation of c-Src was increased in TAM-R cells. Further examination demonstrated that interaction between ERα and EGFR was increased in TAM-R cells. Blocking cSrc phosphorylation by PP2 dissociated the interaction between ERα and EGFR in TAM-R cells. Importantly,TAM could onceagain remarkably inhibit cell growth of TAM-R cells after treated by PP2. Thus,the c-Src inhibitor could reverse TAM-R cells to TAMsensitive cells. Conclusion:Our results suggested that c-Src is a critical molecule to mediate tamoxifen resistance in breast cancer cells through increasing the interaction between ERα and EGFR. Blocking interaction between ERα and EGFR by PP2 can recover the sensitivity to TAM in resistant cells. All of these findings demonstrated that the c-Src inhibitor can be alternatively used with ERαtarget therapy to treat ER-positive breast cancer thereby improving the therapeutic effects on breast cancer patients.
作者
范晓萍
于子溢
楼龙泉
肇毅
Fan Xiaoping;Yu Ziyi;Lou Longquan;Zhao Yi(Department of Ultrasonic Medicine,the Second Affiliated Hospital of Nanjing Medical University,Nanjing 210011;Department of Breast Surgery,the First Affiliated Hospital of Nanjing Medical University,Nanjing 210029,China)
出处
《南京医科大学学报（自然科学版）》
CAS
CSCD
北大核心
2019年第7期966-970,共5页
Journal of Nanjing Medical University(Natural Sciences)
基金
江苏省人力资源和社会保障厅“六大人才高峰”资助项目(2013-WSW-026)
