HEAT SHOCK PROTEIN 90 INHIBITOR 17-AAG SUPPRESSES THE GROWTH OF ENDOMETRIOSIS IN VITRO AND IN VIVO BY INHIBITING ESTROGEN RECEPTOR TRANSCRIPTIONAL ACTIVITY

Abstract

To investigate the effect of HSP90 inhibitor 17–AAG on the growth of endometriosis in vitro and in vivo. Pharmacologic interventions in human endometriotic stromal cells and in an experimental mouse model of endometriosis. Patient recruitment was carried out at the Sixth affiliated Hospital of Sun Yat-sen University from January 2018 to May 2020. Ectopic endometrium (endometriotic tissue, n=15) was collected from patients with ovarian endometriosis undergoing laparoscopy.Primary cultured human endometriotic stromal cells were prepared. Cells were incubated with 10nM, 100nM, 1μM and 10μM 17-AAG for 24 h. The 3-(4,5-dimethylthiaziazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, colorimetric 5'-bromo-2'-deoxy-uridine (BrdU) incorporation assay and Caspase-Glo luminescent-based assays were used to test the cell viability, proliferation ability and apoptosis. Transcriptional activity of estrogen receptor (ER) was measured by luciferase activity after transient transfection of an ERE-tk-Luc reporter construct that contained the consensus estrogen-responsive elements (EREs) sequences. Furthermore, we modeled endometriosis in 30 female C57BL6 mice by intraperitoneal injection of allogeneic endometrial fragments. We divided the mice to 10ug/g and 30ug/g 17-AAG group, control group and vehicle group. 17-AAG inhibited the viability and proliferation of human primary endometriotic stromal cells in a dose-dependent manner from the concentration of 10nM and 100nM 17-AAG respectively. The caspase-3 activities were enhanced significantly in endometriotic stromal cells from 100nM to 10μM 17-AAG treatments. Transcriptional activity of ER were also inhibited significantly by 17-AAG in a dose-dependent way. In mouse model, no obvious weight loss was observed in all groups, and there was no significantly difference in daily weight between those four groups after 30 days of administration. Compared with the model control and vehicle group, the size of ectopic lesions in the treatment group was significantly reduced. The serum TNF-α level was significantly decreased in the treatment group, but there was no statistical difference in the level of serum AMH/E2/P of mice in each group. HSP90 inhibitor 17-AAG controls the growth of endometriosis by inhibiting transcriptional activity of ER. HSP90 inhibitor could provide a hopeful way for better understanding of estrogen signaling on the pathogenesis of endometriosis, as well as for potential clinical application on endometriosis pharmacotherapy.