Molecular defects causing ovarian dysfunction.

S N Kalantaridou; G P Chrousos

doi:10.1111/j.1749-6632.2000.tb06214.x

Home/Archive/PubMed

PubMed · 10818390

Molecular defects causing ovarian dysfunction.

S N Kalantaridou·G P Chrousos

View original source ↗Export metadata ↓

Abstract

The functions of the hypothalamic-pituitary-ovarian and -adrenal axes are intertwined, and molecular defects in either axis may cause ovarian dysfunction. Advances in molecular genetics have allowed new insights into the pathophysiology of ovarian disorders. Specific gene mutations causing delayed puberty and/or ovarian failure, and heterosexual or isosexual precocious puberty have recently been described. The molecular insights gained into ovarian dysfunction have already led to rational therapies for some of these conditions.

Explore related subjects

Aromatase Female Humans Hypogonadism Luteinizing Hormone Male Mutation Ovarian Diseases Primary Ovarian Insufficiency Puberty, Delayed Puberty, Precocious Journal Article Research Support, Non-U.S. Gov't Review

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

S N Kalantaridou, G P Chrousos. 2000. Molecular defects causing ovarian dysfunction.. https://doi.org/10.1111/j.1749-6632.2000.tb06214.x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2001

The direct proliferative stimulus of dehydroepiandrosterone on MCF7 breast cancer cells is potentiated by overexpression of aromatase.

In women after menopause aromatization of adrenal androgens represents the main source of estrogens, which may promote the development of hormone-dependent breast tumor. Several studies have attempted to determine the cell type within carcinomas that is responsible for 'in situ' estrogen biosynthesis and whether the amount produced may sustain relevant biological effects. Here we show P450arom mRNA and protein expression together with immunocytochemical localization of aromatase in the epithelial MCF7 breast cancer cell line. Moreover, we demonstrate that the enhanced aromatization of dehydroepiandrosterone in aromatase transfected MCF7 cells confers biological advantages such as proliferative stimulation similar to that induced by estradiol. Our results suggest that aromatase inhibitors may be particularly effective in the treatment of hormone-dependent breast cancer disease in postmenopausal women.

Aromatase↗

PubMed2001

Genetic susceptibility and environmental estrogen-like compounds.

Environmental chemicals with estrogenic activities have been suggested to be able to interact with the endocrine system. Endogenous estrogen is synthesized in the ovarian theca cells of premenopausal women or in the stromal adipose cells of the breast of postmenopausal women and minor quantities in peripheral tissue. These cells, as well as breast tissue, express all the necessary enzymes for this synthesis, CYP17, CYP11a, CYP19, 17-beta-hydroxysteroid hydrogenase, steroid sulfatase as well as enzymes further hydroxylating estradiol, such as CYP1A1, CYP3A4, CYP1B1, catechol-o-methyltransferase (COMT). Polymorphisms in these enzymes may have a possible role in the link between environmental estrogens and hormone-like substances and the interindividual risk of breast cancer.

Aromatase↗

PubMed2001

Combined treatment with specific ligands for PPARgamma:RXR nuclear receptor system markedly inhibits the expression of cytochrome P450arom in human granulosa cancer cells.

Our previous study demonstrated that PPARgamma specific ligand troglitazone (TGZ) or RXR specific ligand LG100268 (LG) alone decreased the aromatase activity in cultured human ovarian granulosa cells from pre-ovulatory follicles, and combined treatment caused an even greater reduction in this activity. Since similar manners of effects of TGZ or/and LG on the aromatase activity in human ovarian granulosa cancer cell line were observed, we performed the detailed analysis of the mechanisms of these effects using this cell line. The changes in the aromatase activity were associated with comparable changes in the P450arom mRNA levels based on a RNase protection assay. A nuclear run-on assay indicated the P450arom transcript to decrease by 40 and 66% at 24 and 48 h, respectively, after TGZ plus LG treatment. An RNA stability analysis showed the half-life of P450arom mRNA to decrease from 13 to 9 h after the TGZ plus LG treatment. The inhibitory effect of TGZ plus LG on the aromatase activity and P450arom mRNA may not be mediated by the cAMP-PKA pathway that is usually implicated in the regulation of aromatase activity in granulosa cells: because (1) the aromatase activity stimulated by forskolin was not inhibited by TGZ plus LG; (2) the specific PKA inhibitor H89 could not block the inhibitory effect of TGZ plus LG on the aromatase activity; and (3) the luciferase activity of P450arom promoter II did not decrease by the addition of TGZ and LG in transfected cells either at a basic state or in the states stimulated by forskolin or PGE2, respectively. Taken together, these results indicate that TGZ plus LG inhibited the aromatase activity and also decreased the P450arom mRNA level in granulosa cancer cells, and the loss of P450arom mRNA expression was considered to be due to both the decreased transcription and rapid degradation of its RNA.

Aromatase↗