Characterization of estrogen-dependent growth of cultured MCF-7 human breast-cancer cells expressing 17β-hydroxysteroid dehydrogenase type 1

✍ Scribed by Minna M. Miettinen; Matti H. Poutanen; Reijo K. Vihko

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: French
• Weight: 559 KB
• Volume: 68
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/(sici)1097-0215(19961127)68:5<600::aid-ijc8>3.0.co;2-2

✦ Synopsis

I7f3-hydroxysteroid dehydrogenase (I 7HSD) type I converts the weakly active estrogen, estrone, into highly active estradiol. In addition to being essential for gonadal estradiol biosynthesis, the enzyme is also expressed in a significant proportion of breast tumors. In order to study the role of the enzyme in estrogen-dependent growth of breast cancer, MCF-7 breastcancer cells stably expressing human I7HSD type I were generated. In control MCF-7 cells a very low I7HSD activity was observed and, in line with its low estrogenic activity, estrone was devoid of the growth-enhancing effect of estradiol. The presence of the enzyme in the stably transfected MCF-7 cells resulted in a rapid conversion of estrone into estradiol but did not alter the estrogen-receptor concentration in the cells. However, in transfected cells, estrone had a growth-promoting effect practically identical to that of estradiol. The presence or absence of I7HSD type I in breast-cancer cells may therefore be decisive with regard to estrogen exposure and the estrogenresponsive growth of breast-cancer tissues.