Expression of cyclooxygenase-2 in imprint smears of endometrial carcinoma

TT-10 may elevate YAP and repair mouse uterine damage resulting from the inhibition effect of ibuprofen on COX2-PGE2 and YAP

Ibuprofen (IBU) is an emerging environmental contaminant that, in high doses, can damage reproductive organs in humans and other mammals. Recently, its effects on the uterus have been investigated. It is known that the COX2-PGE2 pathway and Yes-associated protein (YAP) are involved in female reproductive organ development and form a COX2-PGE2-EP2-Gas-β-catenin-YAP-COX2 positive feedback loop, in addition, TT-10, a pharmacological product, has been found to increase YAP. In this study, IBU was orally administrated to female mice for 7 d at doses of 0, 50, 100, and 200 mg/kg·bw/day (control, low, medium, and high doses, respectively). In addition, 0, 50, 100, and 200 μmol/L IBU was added in vitro to cultured uterine cells for 7 d at control, low, medium, and high doses, respectively; then, 0, 5, 10, and 20 μmol/L TT-10 were given to the in vitro uterine culture containing 100 μmol/L IBU to observe the effect of YAP activation. The results showed that medium and high doses of IBU inhibited the COX2-PGE2 pathway, decreasing YAP and increasing pYAP, leading to reduced circPVT1, elevated miR-149, and increased apoptosis, ultimately damaging the uterus. Conversely, 10 μmol/L TT-10 maximally enhanced YAP, which regulated COX2-PGE2 pathway activation, increased circPVT1, and decreased miR-149, and promoted cell proliferation, preventing uterine damage. This suggests that IBU may cause uterine damage by inhibiting the COX2-PGE2 pathway and YAP, and that appropriate doses of TT-10 may repair this damage by elevating YAP and stimulating COX2 via the feedback loop.

COX2 Effects on endometrial carcinomas progression

Uterine corpus cancer is one of the most prevalent gynecologic malignancies, among which endometrial cancers (EC) represent about 90 %. Despite the proven predictive value of several immunohistochemical markers, there remains a need to identify new indicators of EC progression and exploit them for therapeutic purposes. Potential candidates with diagnostic and therapeutic efficacy include cyclooxygenases (COXs). We studied 50 EC cases: 30 endometrioid (EEC), 10 serous (SEC), 10 clear-cell endometrial carcinomas (CCEC) and 10 cases of normal endometrial tissues. We investigated the expression of COX2, ER, PR, Ki-67, EGFR, p53, Bcl-2, VEGF, MMP1, CD31, and CD163 immunohistochemically. COX2 levels in EC tissue are elevated compared to the normal endometrium and depend on tumour histological features and differentiation. Elevated COX2 leads to increased tumour cell proliferation, apoptosis inhibition, increased VEGF expression, microvessel density, and M2 macrophage infiltration, and inhibition of PR expression. ER, EGFR, and MMP1 levels are unaffected by COX2, whose levels are independent of patient age and FIGO stage.