Weigel R J, Crooks D L, Iglehart J D, deConinck E C
Department of Surgery, Stanford University, California 94305, USA.
Cell Growth Differ. 1995 Jun;6(6):707-11.
Recent studies have identified an estrogen receptor (ER) promoter upstream of the transcriptional start site originally mapped for the ER gene. We have examined promoter use in a number of breast carcinoma cell lines. MCF7, T47D, BT474, and MDA-MB-361 cell lines all use the P0 promoter, whereas BT20 and ZR75-1 do not demonstrate transcription from this upstream start site. S1 nuclease analysis was used to quantitate the amount of ER mRNA originating from the two different promoters. In MCF7, one-third of the ER mRNA results from transcription originating upstream of the major ER promoter and in T47D, 12% of the message originates from upstream transcription. Promoter use was analyzed in human mammary epithelial cells and human late proliferation endometrium. Upstream promoter use was found to be characteristic of human late proliferation endometrium but not human mammary epithelial cells. These results indicated that certain breast carcinomas demonstrate ER transcription from a promoter not normally active in normal breast epithelium. This activation may involve a factor active in normal human endometrium.
最近的研究在最初为雌激素受体（ER）基因定位的转录起始位点上游鉴定出一个ER启动子。我们已经检测了多种乳腺癌细胞系中启动子的使用情况。MCF7、T47D、BT474和MDA-MB-361细胞系均使用P0启动子，而BT20和ZR75-1并未显示出从这个上游起始位点进行转录。使用S1核酸酶分析来定量源自两个不同启动子的ER mRNA的量。在MCF7中，三分之一的ER mRNA来自于主要ER启动子上游的转录，而在T47D中，12%的信息源自上游转录。对人乳腺上皮细胞和人晚期增殖期子宫内膜中的启动子使用情况进行了分析。发现上游启动子的使用是人类晚期增殖期子宫内膜的特征，而非人乳腺上皮细胞的特征。这些结果表明，某些乳腺癌显示出从正常乳腺上皮中通常不活跃的启动子进行ER转录。这种激活可能涉及在正常人类子宫内膜中活跃的一种因子。
