Fig. 7.

FGFR1 is an upstream effector of L1CAM signaling in OCSC. (A) Ov90-mock and Ov90-L1CAM cells were treated with 20 ng/ml of FGF2 for the indicated time lengths, followed by immunoblotting for phosphorylated or total FGFR1. Vinculin served as loading control. (B) Immunoblotting for phosphorylated or total FGFR1 was also performed on second-generation spheres from Ov90-mock and Ov90-L1CAM cells. ERK1/2 served as loading control. (C) Protein extracts from Ov90-mock and Ov90-L1CAM were immunoprecipitated with the anti-FGFR1 antibody (or with irrelevant IgG) and immunoblotted for L1CAM (top) and FGFR1 (bottom). (D) Ov90-mock and Ov90-L1CAM cells were treated with 70 nM PD173074 (FGFRi) and subjected to the SFE assay. Data are expressed as means ± SEM from three independent experiments. Comparisons between experimental groups were done with two-sided Student’s t-tests; *p < 0.05; ns = not significant. (E) Ov90-mock and Ov90-L1CAM cells were treated with PD173074, followed by immunoblotting for the indicated proteins. α-tubulin served as loading control. (F) Ov90-mock and Ov90-L1CAM cells were grown as spheres under non-permissive, growth factor-free culture conditions (see Fig. 1G) prior to immunoblotting for the indicated proteins. ERK1/2 served as loading control