Dovitinib (Tki258), A Multikinase Inhibitor Of Fgfr, Pdgfr, And Vegfr Tyrosine Kinases, Induces Growth Inhibition In Endometrial Carcinoma Cells

Background: Endometrial carcinoma is the most common gynecological malignancy in the western world. Activating mutations of the fibroblast growth factor receptor 2 (FGFR2) have been described in 12-16% of endometrial cancers. Moreover, vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and platelet-derived growth factor (PDGF) and their receptors are involved in the neovascularization, invasiveness, and metastatic potential of endometrial cancer. Therefore, suppression of FGFR/VEGFR/PDGFR signaling by TKI258 may represent a novel approach for treatment of endometrial cancer. Experimental Design: The aims of this study were 1.) to assess the effect of TKI258 on tumor cell growth in two-dimensional (2D) and three-dimensional (3D) culture assays using a panel of 20 human endometrial cancer cell lines, 2.) to identify candidate molecular markers predicting sensitivity using baseline gene expression profiling and mutational analyses, and 3.) to determine the in vivo antineoplastic activity of TKI258 in endometrial cancer xenograft models. In addition, we screened 200 fresh frozen endometrial cancer specimens to comprehensively assess the distribution pattern of PI3K, PTEN, and FGFR mutations in endometrial cancer. Results: Concentration-dependent anti-proliferative effects of TKI285 using 2D assays were seen in all endometrial cancer cell lines tested, but varied significantly between individual cell lines (IC50 range: 0.42µM – 3.06 µM). The three most sensitive endometrial cancer cell lines demonstrated activating FGFR2 mutations (MFE296: N549K, IC50 0.42µM; AN3CA: N549K and K310R, IC50 0.50µM; MFE280: S252W, IC50 0.66µM). Assessment of TKI258 responses in 3D assays demonstrated similar results to those observed in 2D culture assays in that the 3 cell lines harboring FGFR2 mutations were the most sensitive to TKI258 achieving 100% growth inhibition at a concentration of 1µM. AN3CA and MFE296 endometrial cancer cells formed xenografts in nude mice and antitumor activity was studied in both models. Inhibition of p-FGFR, p-PDGFR, p-VEGFR-2, pAKT and p-ERK1/2 were observed. Comprehensive data on the pattern of PI3K, PTEN and FGFR mutations in endometrial cancer will be provided. Conclusion: TKI258 demonstrates significant antitumor activity in endometrial cancer cells with FGFR2 mutations. This study provides a strong rationale for the clinical evaluation of TKI258 in patients with endometrial cancer, specifically in those harboring FGFR2 mutations. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3589. doi:10.1158/1538-7445.AM2011-3589