ACTIVATION OF THE SILENT PROGESTERONE-RECEPTOR GENE BY ECTOPIC EXPRESSION OF ESTROGEN-RECEPTORS IN A RAT FIBROBLAST CELL-LINE
ACTIVATION OF THE SILENT PROGESTERONE-RECEPTOR GENE BY ECTOPIC EXPRESSION OF ESTROGEN-RECEPTORS IN A RAT FIBROBLAST CELL-LINE
复制标题
DOI：
10.1021/bi00083a039
复制
发表时间：
1993-08-17
期刊：
影响因子：
2.9
通讯作者：
GORSKI, J
中科院分区：
文献类型：
--
作者：
KANEKO, KJ;GELINAS, C;GORSKI, J
我们描述了一种新的雌激素（E2）反应细胞系，Rat 1 +ER，异位表达雌激素受体（ER）的建设和表征。通过逆转录病毒介导的基因转移将人ER cDNA引入Rat 1细胞系中，该细胞系不内源性表达功能性ER。Rat 1 +ER细胞表达功能性ER的基础上放射受体测定，免疫印迹，和瞬时转染实验，使用E2-响应报告质粒。研究了这种异位ER表达对三种内源性E2反应基因，催乳素（PRL），孕酮受体（PR）和表皮生长因子受体（EGFR）的影响。PRL，通常在垂体的催乳细胞中表达，在Rat 1 +ER细胞中完全不表达，有或没有E2添加，并且似乎需要其他因子来表达。相反，虽然PR在Rat 1细胞中不表达，但在Rat 1 +ER细胞中，当加入E2时，PR被诱导。这种诱导似乎发生在转录水平，是不敏感的放线菌酮治疗。这是少数几个例子之一，其中一个基因的表达激活了一个沉默的基因。另一个对比观察结果是，尽管EGFR在Rat 1 +ER细胞中基本表达，但添加E2没有影响。我们的研究描绘了一个复杂的图片E2调节内源性基因：PR基因的激活可能只需要E2和ER的存在下，而EGFR和PRL基因需要的因素，除了ER的基础以及E2调节的表达。
We describe the construction and characterization of a novel estrogen (E2)-responsive cell line, Rat1+ER, which ectopically expresses estrogen receptor (ER). Human ER cDNA was introduced by retrovirus-mediated gene transfer into the Rat1 cell line, which does not express functional ER endogenously. Rat1+ER cells express functional ER based on radioreceptor assays, immunoblotting, and transient transfection experiments using E2-responsive reporter plasmids. The effects of this ectopic ER expression were studied on three endogenous E2-responsive genes, prolactin (PRL), progesterone receptor (PR), and epidermal growth factor receptor (EGFR). PRL, usually expressed in the lactotrophs of the pituitary, is not expressed at all in Rat1+ER cells, with or without E2 addition, and appears to require other factors for expression. In contrast, although PR is not expressed in Rat1 cells, it is induced in Rat1+ER cells upon the addition of E2. This induction appears to occur at the transcriptional level and is insensitive to cycloheximide treatment. This is one of the few examples where the expression of one gene activates an otherwise silent gene. Another contrasting observation is that, although EGFR is basally expressed in Rat1+ER cells, the addition of E2 has no effect. Our studies paint a complicated picture of E2 regulation of endogenous genes: the activation of the PR gene may only require the presence of E2 and ER, whereas EGFR and PRL genes require factors in addition to ER for basal as well as E2-regulated expression.