非基因组活性对雌激素受体阳性乳腺癌细胞Herceptin敏感性的影响

Estrogen receptor improves sensitivity of Herceptin in ER positive breast cancer cells through its non-genomic activity

目的探讨雌激素(estrogen,E2)通过雌激素受体(estrogen receptor,ER)非基因组活性干扰ER阳性(ER+)乳腺癌细胞对人表皮生长因子受体2(human epidermal growth factor receptor 2,HER2)的人源化单克隆抗体赫赛汀(Herceptin)的敏感性及其机制。方法采用Western blot和瞬时转染结合荧光素酶报告基因分析,确定BT-474乳腺癌细胞(ER+/HER2+)和SKBR-3乳腺癌细胞(ER-/HER2+)作为对比研究对象;在E2存在与否的情况下,采用细胞增殖分析比较Heregulin(HRG)诱导的BT-474和SKBR-3细胞对Herceptin敏感性的改变;采用Western blot检测HER2途径下游关键分子MAPK的磷酸化水平。结果在没有E2存在的情况下,Herceptin可有效抑制BT-474和SKBR-3细胞的增殖(P<0.01);在E2存在的情况下,Herceptin对BT-474细胞增殖的抑制效应消失(P<0.01),同时,Herceptin不能降低MAPK的磷酸化;这些现象在SKBR-3乳腺癌细胞中却不会出现。结论 E2可通过ER非基因组活性影响ER+的乳腺癌细胞Herceptin的治疗效果,并可能参与了Herceptin抵抗的发生。

Objective To determine the effect of estrogen（E2） on the sensitivity of Herceptin,a humanized monoclonal antibody directed against human epidermal growth factor receptor 2（HER2）,in ER positive breast cancer cell line and investigate the underlying mechanism of this effect whether through estrogen receptor（ER） non-genomic activity.Methods ER-positive/HER2-positive breast cancer BT-474 cells and ER-negative/HER2-positive SKBR-3 cells was identified by Western blotting and instantaneous carrying combined with fluorescent element enzymes.In the presence or absence of estrogen,the sensitivity of the cells to Herceptin on inhibiting Hereguilin-induced cell proliferation was detected by cell proliferation assay and the effect of Herceptin on the levels of phosphorylation of MAPK and the downstream key molecules of HER2 pathway was observed by Western blotting.Results In absence of estrogen,Herceptin effectively inhibited Hereguilin-induced proliferation of BT-474 and SKBR-3 cells（P0.01）.In presence of estrogen,the inhibitory effect of herceptin on Hereguilin-induced BT-474 cell proliferation was disappeared（P0.01） and Herceptin could not inhibit Hereguilin-induced phosphorylation of MAPK.These changes were not observed in SKBR-3 cells.Conclusion E2 can affect the efficiency of Herceptin on ER positive breast cancer cells through the ER non-genomic activity,which may be involved in the generation of Herceptin resistance.