Journal of Clinical Endocrinology & Metabolism, Vol 55, 428-433, Copyright © 1982 by Endocrine Society
Estradiol 17 beta-hydroxysteroid dehydrogenase activity in human breast fibroadenomas
S Fournier, F Kuttenn, F de Cicco, N Baudot, C Malet and P Mauvais-Jarvis
In the human endometrium, the presence of the progesterone-dependent enzyme
17 beta-hydroxysteroid dehydrogenase (E2DH) permits the conversion of an
active estrogen, estradiol, into a less active one, estrone. This E2DH
activity contributes to the antiestrogenic properties of progesterone. In
the present study, E2DH activity was assayed in 54 surgically removed
fibroadenomas. This benign breast disease was chosen since it offers rather
homogeneous epithelial concentrations and still remains close to normal
breast tissue from a pathological and hormonal point of view. E2DH activity
was highest in fibroadenomas with high epithelial cell density. In
addition, in these high epithelial cell density fibroadenomas (n = 18),
E2DH activity increased markedly throughout the luteal phase of the
menstrual cycle. Thus, it was 3- to 4-fold higher in fibroadenomas removed
at the end of the luteal phase (1520 +/- 166 fmol/mg protein.h) than in
those obtained during the follicular phase (375 +/- 95 fmol/mg protein.h).
In addition, a striking increase in E2DH activity was observed in
fibroadenomas from 5 patients treated with oral progestins (4080 +/- 650
fmol/mg protein.h) and 3 patients receiving progesterone topically applied
upon the breast (3830 +/- 475 fmol/mg protein.h). E2DH activity, therefore,
appears to be an important mechanism involved in the control by
progesterone of estradiol action in breast tissue, as it is in the
endometrium. It is also a good index of cellular differentiation and
progesterone action at the molecular level. It is hypothesized that E2DH
activity might be a specific marker of progesterone receptor itself and
could be proposed in the evaluation of the hormone dependence of human
breast tissue.
