Cavailles V, Augereau P, Rochefort H
Unité Hormones et Cancer (U 148) INSERM, Université de Montpellier I, France.
Biochem Biophys Res Commun. 1991 Jan 31;174(2):816-24. doi: 10.1016/0006-291x(91)91491-t.
Cathepsin D is a lysosomal protease produced and secreted in excess by most human breast cancer cells. In MCF7 cells, estrogens stimulate cathepsin D expression at the mRNA level via a mechanism independent of de novo protein synthesis. We have isolated the human cathepsin D gene and its 5' flanking sequences from a MCF7 genomic library. To demonstrate its transcriptional estrogen regulation, we constructed chimeric recombinants bearing different fragments of the cathepsin D gene 5' proximal region inserted in front of the bacterial chloramphenicol acetyl transferase reporter gene. By transient cotransfection with the estrogen receptor expression vector into MCF7 cells, we showed that a 240 bp fragment located in the 5' proximal region of the gene was able to mediate transcriptional estrogen activation. This induction was concentration-dependent and suppressed by the antiestrogen ICI 164, 384.
组织蛋白酶D是一种溶酶体蛋白酶，大多数人类乳腺癌细胞都会过量产生并分泌这种酶。在MCF7细胞中，雌激素通过一种不依赖于从头合成蛋白质的机制，在mRNA水平上刺激组织蛋白酶D的表达。我们从MCF7基因组文库中分离出了人类组织蛋白酶D基因及其5'侧翼序列。为了证明其转录的雌激素调节作用，我们构建了嵌合重组体，这些重组体带有插入到细菌氯霉素乙酰转移酶报告基因前面的组织蛋白酶D基因5'近端区域的不同片段。通过与雌激素受体表达载体共转染到MCF7细胞中，我们发现位于该基因5'近端区域的一个240 bp片段能够介导转录的雌激素激活。这种诱导是浓度依赖性的，并被抗雌激素ICI 164,384所抑制。
