目的：探讨黑素瘤抗原（melanoma antigen gene, MAGE）-A11对雌激素受体（estrogen receptor, ER）介导的乳腺癌MCF-7细胞增殖的影响。方法： 利用RT-PCR及Western blotting筛选出ER表达阳性的人乳腺癌MCF-7细胞作为模式细胞，采用基因转染、RT-PCR和Western blotting检测MAGE-A11对17β-雌二醇（17β-E）诱导的ER下游靶基因Efp表达的影响，采用免疫共沉淀法检测MCF-7细胞中MAGE-A11和ER蛋白的相互作用，采用MTT法和克隆形成实验分别检测MAGE-A11及17β-E处理对MCF-7细胞生存率和细胞克隆形成数的影响。结果： ER阳性MCF-7细胞经17β-E处理24 h后，下游靶基因Efp的mRNA（2.97±0.16 vs 1.71±0.09，P<0.05）和蛋白表达水平显著升高（2.65±0.12 vs 0.92±0.06, P<0.05）；转染MAGE-A11的MCF-7细胞经17β-E 24 h处理后，其Efp的mRNA（4.01±0.19 vs 2.97±0.16, P<0.05）及蛋白表达（3.52±015 vs 2.65±0.12, P<0.05）更显著增加。免疫共沉淀结果显示，外源性MAGE-A11与ER之间存在相互作用。MCF-7细胞经17β-E处理后细胞增殖率显著增加\[（152±6.7）% vs （108±4.8%）, P<0.05\]，转染MAGE-A11的MCF-7细胞经17β-E处理后细胞增殖率更显著增加\[（181±8.6）% vs （152±6.7）%, P<0.05\]；17β-E处理后MCF-7细胞克隆形成数显著增多\[（77±5) vs (18±2)个，P<0.05\]，转染MAGE-A11的MCF-7细胞经17β-E处理后细胞的克隆形成数更显著增加\[（125±6）vs （77±5）个, P<0.05）。结论： 在ER阳性的乳腺癌MCF-7细胞中，MAGE-A11可通过与ER的相互作用增强ER介导的Efp的表达，从而促进细胞增殖，MAGE-A11可能成为ER阳性乳腺癌内分泌治疗耐药的靶基因。

Objective:To investigate the effect of melanoma antigen gene-A11 (MAGE-A11) on estrogen receptor (ER)-mediated cell proliferation of breast cancer MCF-7 cells.Methods:RT-PCR and Western blotting confirmed ER-positive MCF-7 cells were transfected with pCMV-AC-MAGE-A11-GFP and pCMV-AC-GFP respectively. Wild-type and transfected MCF-7 cells were treated with 17β-estradiol (17β-E). After treatment, estrogen-responsive finger protein (Efp) was assessed by RT-PCR and Western blotting, protein interaction between MAGE-A11 and ER by immunoprecipitation, cell viability by MTT assay and colony-forming capacity by colony formation assay.Results: Treatment with 17β-E significantly increased Efp mRNA and protein proteins in both wild-type and transfected MCF-7 cells (P<0.05). Evident interactions between MAGE-A11 and ER were detected in both wild-type and transfected MCF-7 cells. Estrogen treatment also significantly increased cell viability and colony formation in wild-type and MAGE-A11-transfected MCF-7 cells (P<005). Conclusion: In ER-positive MCF-7 cells, MAGE-A11 is capable of enhancing the expression of the ER target gene Efp and cell proliferation through direct interaction with ER. This finding suggests that MAGE-A11 may offer a potential therapeutic target for resistant ER-positive breast cancer.

国家自然科学基金资助项目（No.81001178); 河北省科技支撑计划资助项目（No. 14277732D ）