抑制雌激素调控的靶基因LRP16表达能削弱ERα介导的转录激活活性  

Inhibition of estrogen-regulated LRP16 attenuated ERalpha-mediated transactivation activity

作　　者：韩为东[1] 臧丽[1] 伍志强[1] 李琦[1] 赵亚力[1] 巴建明[2] 陆菊明[2] 潘长玉[2] 母义明[2] 

机构地区：[1]解放军总医院基础医学研究所分子生物学研究室,北京100853 [2]解放军总医院内分泌科,北京100853

出　　处：《肿瘤》2007年第3期186-189,共4页Tumor

基　　金：国家自然科学基金(编号:30471990;30572107;30670809)

摘　　要：目的:探讨抑制雌激素(E2)调控的靶基因LRP16表达对雌激素受体α(ERα)介导转录激活活性的影响。方法:将针对LRP16合成的小于扰RNA,与ERα表达载体、雌激素反应性元件荧光素酶报道载体(pGL-3-S10或3×ERE-Luc)共转染乳腺癌细胞MCF-7,双荧光素酶检测方法测定pGL-3-S10或3×ERE-Luc报道子的相对荧光素酶活性;E2刺激培养已建立的稳定抑制LRP16表达的MCF-7细胞,Northern blot方法检测比较具有不同LRP16表达水平的MCF-7细胞中ERα下游靶基因对E2的反应性变化。结果:抑制LRP16表达降低了ERα对其反应性报道子(pGL-3-S10和3×ERE-Luc)的激活活性;同时也降低了ERα下游靶基因对E2的反应性上调效应,其中包括E2F1、维甲酸受体α(RARα)、c-fos、cyclin D1和MTA3,但对cathepsin D的表达无影响。结论:抑制ERα靶基因LRP16的表达可以下调ERα介导的转录激活活性,表明LRP16对ERα信号转导通路具有反馈增强效应,提示LRP16在ERα阳性的乳腺癌发生与进展中应有重要作用。Objective：To investigate the effect of inhibition of the estrogen-regulated LRP 16 expression on ERalpha-mediated transactivation activity. Methods： Human breast cancer MCF-7 cells were co-transfected with LRP16-specific small interfering RNA, ERalpha expression vector, and the estrogen-responsive luciferase reporter vector （pGL-3-S10 or 3 ×ERE-Luc）. The relative luciferase activity was measured by Dual-luciferase Report Assay System. E2 was used to stimulate the MCF-7 cells whose expression of LRP16 was stably inhibited. Northern blot was used to determine the responsiveness of ERalpha target genes to estrogen in MCF-7 cells. Results：Inhibition of endogenous LRP 16 expression decreased the relative luciferace activities of ERalpha response reporter （pGL-3-S10 and 3 × ERE-Luc）. Suppression of LRP16 expression in MCF-7 cells attenuated the stimulative responsiveness of estrogen-induced genes （E2F1, RARa, c-fos, cyclin D1, and MTA3） to E2, but had no effects on the expression of cathepsin D. Conclusion： Inhibition of ERalpha target gene LRP16 causes downregulation of Era-mediated transactivation activity, indicating a feedback-enhanced role of estrogen-induced LRP16 to ERalpha signaling pathway. The data suggested that LRP16 should play an important role in the carcinogenesis and/or progression of ERalpha-positive breast cancer.

关 键 词：雌激素受体Α 基因表达调控 反式激活(遗传学) 基因 LRP16 

分 类 号：Q291[生物学—细胞生物学] Q786