Effects of a Histone Deacetylase Inhibitor on the Progesterone-response of Human Endometrial Stromal Fibroblasts Suggests Epigenetic Differences among Women with Endometriosis

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 561-585-Ovarian & Uterine Function II
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-582
Sahar Houshdaran*, Juan C Irwin and Linda C Giudice
UCSF, San Francisco, CA
Background: Endometriosis is an estrogen (E2)-responsive progesterone (P4)-resistant disorder with an aberrant gene expression profile in eutopic endometrium, and recent evidence suggests aberrant epigenetic profiles associated with these abnormalities. Histone acetylation and deacetylation are important epigenetic mechanisms in regulation of gene expression. To investigate the role of histone acetylation in P4responsiveness in normal and disease endometrium, we treated endometrial stromal fibroblasts (eSF) with the histone deacetylase inhibitor Trichostatin A (TSA) in vitro and measured its effect on decidualization potential.

Methods: Human eSF from participants without uterine pathology (n=5) and from patients with severe (n=5) and mild (n=4) endometriosis were obtained from the NIH UCSF Endometrial Tissue and DNA Bank. Toxicity experiments with TSA concentrations of 250 nM, 500 nM, 1μM, 10 μM, and 100 μM for 12hrs, 24hrs, 48hrs, 72hrs and 96hrs determined 1μM TSA for 72hrs as the maximum-nontoxic treatment regimen based on cellular proliferation assays. Subsequently, cells were treated with E2+P4, vehicle, TSA, or E2+P4plus TSA for 15 days, wherein TSA was administered as a single 3-day treatment or multiple 3-day treatments. Single treatments were applied at day 0 to 3, 6 to 9, or 12 to15. Multiple treatments were applied at day 0 to 3, 6 to 9, and 12 to15 (total 9 days). Decidualization was assessed by IGFBP1 protein level by ELISA.

Results: In controls, E2+P4 induced decidualization after 15 days while vehicle and TSA in single or multiple treatments did not. Also, E2+P4 plus TSA, in single or multiple treatments, did not affect decidualization. Some endometriosis samples decidualized and some did not, independent of stage. In the non-decidualizing group, TSA, alone or together with hormones (in single or multiple treatments) did not rescue decidualization. However, in decidualizing endo samples, multiple treatments of E2+P4plus TSA (but not single treatments), resulted in significantly decreased decidualization, while it was ineffective in controls.

Conclusion: Our data indicate that decidualizing or non-decidualizing endometrium in women with disease represent two subtypes with different histone modifications that is not reflective of disease stage. Further investigation of epigenetic regulation of decidualization in normal and disease endometrium is warranted to better understand the associated sub-fertility in patients with endometriosis.

Nothing to Disclose: SH, JCI, LCG

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: Supported by: The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)/NIH through cooperative agreement U54HD055764–06 as part of the Specialized Cooperative Centers Program in Reproduction and Infertility Research (LCG).