P-346: Ciclooxygenase-2 (COX-2) inhibitor induces apoptosis and inhibits cell proliferation in endometrial epithelial cells from patients with endometriosis (EDT)

Abstract

There is room for improvement in the medical therapy of EDT. COX-2 inhibitors are lately emerging as a new generation of therapeutic drugs in cancer treatment in combination with chemotherapy. Celecoxib, a potent selective COX-2 inhibitor, strongly suppresses cell proliferation and induces cell death in different tumor cell lines and in oncogenic animal models (Bundred N et al, Br J Cancer,93 Suppl 1:S10, 2005). In addition, Efstathiou et al. have shown that Celecoxib significantly suppresses endometriosis in a murine model (Fertil Steril 83:171, 2005). In this context, the purpose of this study was to evaluate the effect of Celecoxib on cell proliferation, apoptosis and COX-2 protein expression in endometrial epithelial cell (EEC) cultures from patients and controls. Apoptosis, cell proliferation and COX-2 expression were evaluated in Celecoxib treated EEC from EDT patients and controls. Endometrial biopsies were taken during the proliferative phase in 14 untreated patients with EDT diagnosed by laparoscopy and in 8 Controls (without EDT). Purification and culture of EEC were done according to the technique described by Meresman et al. (Fertil Steril 80, suppl 2:702, 2003). Cultures were treated with Celecoxib in different doses between 10 and 100μM. Percentages of apoptotic cells were measured using the acridine orange - ethidium bromide technique and cell proliferation was evaluated by 3H-Thymidine incorporation. Preliminary studies were performed to assess COX-2 expression by western blot in proteins extracted from 25, 40, 50, 75 and 100 μM Celecoxib treated EEC cultures from patients with endometriosis. Comparisons among groups were performed by Kruskal-Wallis nonparametric ANOVA test, and Dunn′s multiple comparisons test. Celecoxib 50, 75, and 100 μM induced apoptosis and inhibited cell proliferation in EEC from patients with EDT and controls. Lower concentrations of Celecoxib did not induce any significant changes in cell proliferation rates and apoptosis levels. We found no differences in any of parameters studied between cell cultures from patients and controls (see table 1, Mean ± SEM, *p<0.05, **p<0.01, ***p<0.001 vs. basal). In addition, COX-2 expression was similar in all Celecoxib treated EEC cultures.Tabled 1 Our data showed that Celecoxib produced a significant and positive effect on apoptosis and cell proliferation on EEC. This growth inhibitory effect appears to be independent of the COX-2 protein expression. These findings support the further investigation of COX-2 inhibitors as a treatment option in EDT.