Thériault C, Labrie F
MRC Group in Molecular Endocrinology, CHUL Research Center, Quebec, Canada.
J Steroid Biochem Mol Biol. 1991 Feb;38(2):155-64. doi: 10.1016/0960-0760(91)90121-k.
In order to characterize the main enzymatic systems involved in androgen and estrogen formation as well as metabolism in ZR-75-1 human breast cancer cells, incubation of intact cells was performed for 12 or 24 h at 37 degrees C with tritiated estradiol (E2), estrone (E1), androst-5-ene-3 beta, 17 beta-diol (5-ene-diol), dehydroepiandrosterone (DHEA), testosterone (T), androstenedione (4-ene-dione), dihydrotestosterone (DHT) or androsterone (ADT). The extra- and intracellular steroids were extracted, separated into free steroids, sulfates and non-polar derivatives (FAE) and identified by HPLC coupled to a Berthold radioactivity monitor. Following incubation with E2, 5-ene-diol or T, E1, DHEA and 4-ene-dione were the main products, respectively, thus indicating high levels of 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD). When 4-ene-dione was used, on the other hand, a high level of transformation into 5 alpha-androstane-3,17-dione (A-dione), Epi-ADT and ADT was found, thus indicating the presence of high levels of 5 alpha-reductase as well as 3 alpha- and 3 beta-hydroxysteroid dehydrogenase. Moreover, some T was formed, due to oxidation by 17 beta-HSD. No estrogen was detected with the androgen precursors T or 4-ene-dione, thus indicating the absence of significant aromatase activity. Moreover, significant amounts of sulfates and non-polar derivatives were found with all the above-mentioned substrates. The present study shows that ZR-75-1 human breast cancer cells possess most of the enzymatic systems involved in androgen and estrogen formation and metabolism, thus offering an excellent model for studies of the control of sex steroid formation and action in breast cancer tissue.
为了表征参与ZR-75-1人乳腺癌细胞中雄激素和雌激素生成及代谢的主要酶系统，将完整细胞在37℃下与氚化雌二醇（E2）、雌酮（E1）、雄甾-5-烯-3β,17β-二醇（5-烯二醇）、脱氢表雄酮（DHEA）、睾酮（T）、雄烯二酮（4-烯二酮）、二氢睾酮（DHT）或雄酮（ADT）孵育12或24小时。提取细胞外和细胞内的类固醇，分离为游离类固醇、硫酸盐和非极性衍生物（FAE），并通过与Berthold放射性监测仪联用的HPLC进行鉴定。用E2、5-烯二醇或T孵育后，分别以E1、DHEA和4-烯二酮为主要产物，因此表明17β-羟基类固醇脱氢酶（17β-HSD）水平较高。另一方面，当使用4-烯二酮时，发现其大量转化为5α-雄烷-3,17-二酮（A-二酮）、表雄酮和雄酮，因此表明存在高水平的5α-还原酶以及3α-和3β-羟基类固醇脱氢酶。此外，由于17β-HSD的氧化作用，还形成了一些T。用雄激素前体T或4-烯二酮未检测到雌激素，因此表明不存在显著的芳香化酶活性。此外，用上述所有底物均发现了大量的硫酸盐和非极性衍生物。本研究表明，ZR-75-1人乳腺癌细胞拥有参与雄激素和雌激素生成及代谢的大多数酶系统，因此为研究乳腺癌组织中性类固醇生成和作用的控制提供了一个极好的模型。
