Identification of novel indazole-based inhibitors of fibroblast growth factor receptor 1 (FGFR1)

Background: Overactivity of fibroblast growth factor receptor 1 (FGFR1) is associated with various tumors, particularly breast cancer, prostate cancer, non-small-cell lung carcinoma, myeloproliferative diseases, which makes this protein kinase a promising therapeutic target for anticancer therapy. Objective: The main aim of this study is to identify novel FGFR1 inhibitors. Method: In order to find FGFR1 inhibitors, virtual screening experiments were performed using AutoDock software. Best-scored compounds were tested in vitro using P32 radioactive kinase assay. Results: Small-molecular inhibitors of protein kinase FGFR1 were identified among indazole derivatives. The most active compound [3-(3,4-dichloro-phenyl)-1H-indazol-5-yl]-(2,3-dihydro-1H-cyclopenta[b]quinolin-9-yl)-amine (1) inhibits FGFR1 with IC50 value of 100 nM. According to molecular docking results, this compound interacts simultaneously with adenine- and phosphate-binding regions of protein kinase FGFR1. The structure-activity relationships have been investigated and binding mode has been predicted. Conclusion: The compound 1 can be used for further structural optimization and biological research.