Identification of Pharmacodynamic Transcript Biomarkers in Response toFGFRInhibition by AZD4547

Abstract

The challenge of developing effective pharmacodynamic biomarkers for preclinical and clinical testing of FGFR signaling inhibition is significant. Assays that rely on the measurement of phospho-protein epitopes can be limited by the availability of effective antibody detection reagents. Transcript profiling enables accurate quantification of many biomarkers and provides a broader representation of pathway modulation. To identify dynamic transcript biomarkers of FGFR signaling inhibition by AZD4547, a potent inhibitor of FGF receptors 1, 2, and 3, a gene expression profiling study was performed in FGFR2-amplified, drug-sensitive tumor cell lines. Consistent with known signaling pathways activated by FGFR, we identified transcript biomarkers downstream of the RAS-MAPK and PI3K/AKT pathways. Using different tumor cell lines in vitro and xenografts in vivo, we confirmed that some of these transcript biomarkers (DUSP6, ETV5, YPEL2) were modulated downstream of oncogenic FGFR1, 2, 3, whereas others showed selective modulation only by FGFR2 signaling (EGR1). These transcripts showed consistent timedependent modulation, corresponding to the plasma exposure of AZD4547 and inhibition of phosphorylation of the downstream signaling molecules FRS2 or ERK. Combination of FGFR and AKT inhibition in an FGFR2-mutated endometrial cancer xenograft model enhanced modulation of transcript biomarkers from the PI3K/AKT pathway and tumor growth inhibition. These biomarkers were detected on the clinically validated nanoString platform. Taken together, these data identified novel dynamic transcript biomarkers of FGFR inhibition that were validated in a number of in vivo models, and which are more robustly modulated by FGFR inhibition than some conventional downstream signaling protein biomarkers. Mol Cancer Ther; 15(11); 2802-13. Ó2016 AACR.

Genomic coamplification of CDK4/MDM2/FRS2 is associated with very poor prognosis and atypical clinical features in neuroblastoma patients

“…Contrary to our findings, a recent study found that FRS2 knockdown promotes tumor progression in two NB cell lines . However, FRS2 is amplified in many cancer types so FRS2 presents typical oncogenic features . Furthermore, the focal amplification of 12q15 region in many cancers, as in primary NB tissues, is correlated with increased mRNA expression of FRS2 , suggesting a functional relevance of the copy number gain.…”

“…The FRS2 gene is located close to MDM2 and CDK4 within the 12q13‐15 segment. FRS2 is a key adaptor protein in the fibroblast growth factor receptor (FGFR) pathway, binding to FGFR and subsequently activating downstream signaling cascades . FRS2 is involved in cell differentiation and proliferation, inducing downstream activation of the RAS‐MAPK pathway .…”

“…Molecular genomic profiling by array‐comparative genome hybridization (a‐CGH) of tumor tissues biobanked at the time of diagnosis here lead us to describe the occurrence of a new, sporadic fibroblast growth factor receptor substrate 2 ( FRS2 ) gene amplification distinct from MYCN . Previous studies have found that abnormal activation of the FRS2 gene is related to tumorigenesis in some cancers . We have also used public available transcriptomics data to evaluate the transcriptional consequences of FRS2 amplification for NB patients.…”

Androgen Receptor Pathway-Independent Prostate Cancer Is Sustained through FGF Signaling

“…To further assess FGF pathway activity, we measured a panel of transcripts shown to reflect the dynamic output of FGF receptor (FGFR) signaling (Delpuech et al, 2016). Several transcripts comprising this FGFR signature were increased more than 10-fold in LNCaP APIPC cells including DUSP6 , ETV4 , and EGR1 , and LNCaP APIPC cells showed significant FGFR and MAPK pathway enrichment scores (Figure 3K).…”

Interaction between the estrogen receptor and fibroblast growth factor receptor pathways in non-small cell lung cancer

“…Since NSCLC cell lines expressed multiple FGFs and FGFRs, we used phosphorylation of the FGFR docking protein fibroblast growth factor receptor substrate 2 (FRS2) [24] as a readout for signaling from the FGFR pathway in the presence of AZD4547 and fulvestrant (Figure 5). Cells were treated with DMSO vehicle, AZD4547, fulvestrant or the combination and cell lysates were probed for phospho-FRS2 (pFRS2).…”