雌激素受体相关受体α过度表达对雌激素受体阴性的子宫内膜癌细胞增殖的影响

目的探讨雌激素受体相关受体α（ERRα）在雌激素受体（ER）阴性及阳性的子宫内膜癌细胞中的作用。方法 将真核表达质粒pSG—ERRα（0．5、1．0、1．5、2．5μg）瞬时转染子宫内膜癌细胞株HEC-1A（ER阴性）、HEC-1B（ER阴性）、Ishikawa（ER阳性）,采用定量RT-PCR技术和蛋白印迹法（westernblot）检测ERRα mRNA和蛋白的表达情况;采用流式细胞仪分析细胞周期,并计数细胞的增殖情况。结果 转染pSG—ERRα质粒后,HEC-1A、HEC-1B、Ishikawa细胞在mRNA和蛋白水平均能检测到ERRet的表达增加。HEC-1B、HEC-1A、Ishikawa细胞未转染时ERRα mRNA的表达水平分别为2104．2、2870．6、1476．8copies／ng,转染后3者ERRα mRNA的表达水平分别为9835．3、9644．4、8008．6copies／ng,分别与各自未转染的细胞比较,差异均有统计学意义（P值分别为0．004、0．002、0．002）。HEC-1A、HEC-1B、Ishikawa细胞未转染时ERRα蛋白的表达水平分别为0．823、0．192、0．673,转染后3者ERRα蛋白的表达水平分别为1．128、1．104、1．008,分别与各自未转染的细胞比较,差异均有统计学意义（P〈0．05）。随着转染pSG—ERRα质粒质量的增加,HEC-1A、HEC-1B细胞的S期和G2／M期细胞比例明显上升（P〈0．01）。HEC-1B、HEC-1A细胞转染0．5、1．0μg pSG-ERRα质粒后,细胞在转染后24—96h间生长速度显著加快（P〈0．05）。结论ERRα过度表达是ER阴性的子宫内膜癌细胞株HEC-1A、HEC-1B的一种细胞增殖机制。

Overexpression of estrogen receptor-related receptor alpha can stimulate estrogen receptor negative endometrial cancer cell proliferation

OBJECTIVE: To investigate the role of human estrogen receptor-related receptor (ERR) alpha, a submember of orphan receptors, in the tumorigenesis of endometrial cancer. METHODS: Plasmid of pSG-ERRalpha was transfected into endometrial cancer cell lines HEC-1A, HEC-1B, and Ishikawa. Real-time quantitative RT-PCR and western blot were used to analyze the mRNA and protein expression of ERRalpha in endometrial cancer cell. Flow cytometry was used to analyze the cellular growth. RESULTS: Expressions of the ERRalpha were significantly increased in the endometrial cancer cells transfected with pSG-ERRalpha plasmid; expression of the ERRalpha mRNA in HEC-1A cell was 9644.4 copies/ng, HEC-1B: 9835.3 copies/ng, and Ishikawa: 8008.6 copies/ng (P < 0.01); expression of the ERRalpha protein in HEC-1A cell was 1.128, HEC-1B: 1.104, and Ishikawa: 1.008 (P < 0.05). Flow cytometry showed over-expression of ERRalpha was accompanied by increased HEC-1A and HEC-1B cells in S and G(2)/M phase (P < 0.01), while this could not be observed in the estrogen receptor (ER) positive endometrial cancer cell line Ishikawa. Furthermore, cellular growth analysis showed that over-expression of ERRalpha induced cell growth increase of the ER negative endometrial cancer cells HEC-1A and HEC-1B (P < 0.05). CONCLUSION: Over-expression of ERRalpha could stimulate ER negative endometrial cancer cell proliferation independent of estrogen-ER pathway.