Fig. 3: FGFR2-G3BP2 kinase is constitutively active and sensitive to FGFR inhibition. | npj Precision Oncology

Fig. 3: FGFR2-G3BP2 kinase is constitutively active and sensitive to FGFR inhibition.

From: Leveraging patient derived models of FGFR2 fusion positive intrahepatic cholangiocarcinoma to identify synergistic therapies

Fig. 3

A FGFR2 kinase activity is constitutively active in the PDC-DUC18828 model. FGFR kinase activation is examined by western blot under the condition of complete culture media (Normal), serum-free media (Starve), and FGF1 stimulation for 5, 10, 30, and 60 min (FGF1 5, 10, 30, 60 min). FGFR is phosphorylated (activated) to a similar extent in serum-free media when compared to cells grown in complete culture media, confirming constitutive activation, which is further augmented with FGF1 stimulation, B FGFR2 kinase activity is constitutively active in the PDO-DUC18828 model. FGFR kinase activation is examined by western blot under the condition of complete culture media (Normal), nutrient-free media (Starve), FGF10 stimulation for 60 min (FGF10), and FGF1 stimulation for 60 min (FGF1). FGFR phosphorylation remains detectable, even in nutrient-free media, confirming constitutive activation, which is further augmented by FGF10 and FGF1 stimulation. C FGFR kinase activation is sensitive to pemigatinib (Pemi), an FDA-approved selective FGFR inhibitor, in the PDC-DUC18828 model. FGFR kinase activation is examined by western blot after treatment with pemigatinib (Pemi) doses shown, with significant reduction in activity starting at 10 nM. D FGFR kinase activation is sensitive to pemigatinib in the PDO-DUC18828 model. FGFR kinase activation is examined by western blot after treatment with pemigatinib (Pemi) doses shown, with significant reduction in activity starting at 50 nM. E Effect of growth factors on organoid viability, determined by Alamarblue after 7 days in culture under different conditions. All results are normalized to the +EHF condition and presented as the mean +/− standard deviation (error bars) for three biologically independent replicates. Note, addition of EHF is able to overcome FGFR inhibition (E, 100 ng/mL hEGF; H, 25 ng/mL hHGF; F, 100 ng/mL hFGF10; P, 50 nM pemigatinib). Of these three factors, hEGF has the greatest impact on rendering the PDO less sensitive to pemigatinib. F Brightfield microscopy images of E demonstrating organoid growth in the absence of EHF, loss of viability after treatment with pemigatinib in media lacking EHF, but preserved viability despite treatment with pemigatinib when EHF is present. Scale bar, 360 μm.

Back to article page