Abstract 1191: Anti-tumor effect of selective progesterone receptor modulator (ulipristal acetate) on endometrial cancer cell lines

Abstract

Abstract Background: Endometrial cancer is the most common malignancy of the female reproductive tract and the third most common cause of death from women's cancer. Risk factors of endometrial cancer include high levels of estrogen, obesity, diabetes mellitus, breast cancer, long term use of tamoxifen, late menopause, high blood pressure, and increasing age. Although the exact mechanisms in endometrial carcinogenesis due to chronic exposure are unclear, it is though that the pro-proliferative and DNA-damaging effects of estrogen and its metabolites, related with and insufficient counterbalance by progesterone, promote the hyper-proliferation and transformation of cells. Selective progesterone receptor modulator (SPRM) is an agent that acts on the progesterone receptor. Ulipristal acetate (UA) is one of SPRM and other SPRM, such as Mifepristone, showed inhibitory effect on various endometrial cancer cell lines. UA has been available as an emergency contraception and a treatment for uterine leiomyoma. The effect of UA on leiomyoma is decreasing neovascularization, proliferation, and viability. Objective: This study was undertaken to investigate antitumor effect of UA and to explore the effect of combination treatment with chemotherapy drug in endometrial cancer. Method: Inhibitory concentration (IC), proliferation assay, and migration assay were performed using Ishikawa, HEC-1-A, HEC-1-B, and/or patient-derived primary cancer cells (PCC). Different concentration of UA were treated in endometrial cancer cell lines and PCCs for the each assay. The CellTiter-Glo assay were performed to investigate IC50 in cell lines and PCCs. Crystal violet staining and wound healing assay were performed to examine cell proliferation and migration. Results: UA inhibited cell viability of endometrial cancer cell lines and PCCs at high concentration, most abviously 10uM in dose-dependent manner. In combination treatment assay with paclitaxel, UA showed synergistic anti-tumor effect with low-dose of paclitaxel on cell lines and PCCs. Conclusions: We showed that combination treatment of UA and paclitaxel effectively than single treatment by low dosage. In summary, we are actively exploring new effective applicable drugs for endometrial cancer, and our data suggest that UA may have therapeutic value with chemo-combination treatment of patients with endometrial cancer. Citation Format: Ha-Young Lee, A Ra Ko, Dong-Woo Kang, Yu-Seon Kim, Su-Min Kim, Tae-Wook Kang, Shin-Wha Lee, Yong-Man Kim. Anti-tumor effect of selective progesterone receptor modulator (ulipristal acetate) on endometrial cancer cell lines. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1191.