Fig. 5: CDKN1C upregulation halts the transactivation of E2F1 target genes in FGFR1 dependent manner.

A Model showing Rb-E2F1 regulation by Cyclin-CDK complex. B Blots show decreased Rb phosphorylation upon FGFR1 knockdown in Z-138 and Granta-519 cell lines. (C) Blots show a decreased Rb phosphorylation upon erdafitinib treatment in Z-138 and Granta-519 cell lines, Actin for Z-138 and Granta-519 in (B) is the same as Fig. 3G, and in (C) is the same as Fig. 3H (different exposures), as the same blots were probed for Rb and EZH2 (D) Heatmap for qPCR analysis depicting the decrease in expression of E2F1 target genes upon FGFR1 knockdown in Z-138 and Granta-519 cell lines. E Heatmap for qPCR analysis depicts decreased expression of E2F1 target genes upon erdafitinib treatment in Z-138 and Granta-519 cell lines. 2-way ANOVA (a = 0.05). F Blots of the rescue of EZH2 expression upon transfection of EZH2 overexpression plasmid in the presence of erdafitinib and the corresponding change in CDKN1C, KDM2B, phospho-Rb expression in Z-138 and Granta-519 cell lines; EZH2-OE (-) lane is a vector control transfected lane, complete blot and exposures used in Suppl Fig. S7A and S7B. G Protein expression of CDKN1C, EZH2, KDM2B, and phospho-Rb upon CDKN1C knockdown in the presence of erdafitinib in Z-138 and Granta-519 cell lines; si-CDKN1C (-) lane is scrambled si-RNA transfected lane. H Heatmap for qPCR analysis in Z-138 cells shows rescue of E2F1 target genes previously downregulated by erdafitinib by now knocking-down CDKN1C in the presence of erdafitinib. I Co-immunoprecipitation of CDKN1C and E2F1 followed by western blot in Granta-519 and Z-138 cells. Model showing proposed hypothesis of CDKN1C mediated regulation of E2F1 target genes.