Discovery of a small molecule ligand of FRS2 that inhibits invasion and tumor growth

Abstract

Purpose Aberrant activation of the fibroblast growth factor receptor (FGFR) family of receptor tyrosine kinases drives oncogenic signaling through its proximal adaptor protein FRS2. Precise disruption of this disease-causing signal transmission in metastatic cancers could stall tumor growth and progression. The purpose of this study was to identify a small molecule ligand of FRS2 to interrupt oncogenic signal transmission from activated FGFRs. Methods We used pharmacophore-based computational screening to identify potential small molecule ligands of the PTB domain of FRS2, which couples FRS2 to FGFRs. We confirmed PTB domain binding of molecules identified with biophysical binding assays and validated compound activity in cell-based functional assays in vitro and in an ovarian cancer model in vivo. We used thermal proteome profiling to identify potential off-targets of the lead compound. Results We describe a small molecule ligand of the PTB domain of FRS2 that prevents FRS2 activation and interrupts FGFR signaling. This PTB-domain ligand displays on-target activity in cells and stalls FGFR-dependent matrix invasion in various cancer models. The small molecule ligand is detectable in the serum of mice at the effective concentration for prolonged time and reduces growth of the ovarian cancer model in vivo. Using thermal proteome profiling, we furthermore identified potential off-targets of the lead compound that will guide further compound refinement and drug development. Conclusions Our results illustrate a phenotype-guided drug discovery strategy that identified a novel mechanism to repress FGFR-driven invasiveness and growth in human cancers. The here identified bioactive leads targeting FGF signaling and cell dissemination provide a novel structural basis for further development as a tumor agnostic strategy to repress FGFR- and FRS2-driven tumors.

Mechanism of ERBB2 gene overexpression by the formation of super-enhancer with genomic structural abnormalities in lung adenocarcinoma without clinically actionable genetic alterations

“…S15). FRS2 (Fibroblast Growth Factor Receptor Substrate 2) plays a critical role in activating the MAPK and PI3K signaling pathways, which are essential for cell proliferation, migration, and survival [ 31 ]. It has been identified as oncogenic and is amplified in high-grade serous ovarian cancer, highlighting its potential as a driver gene in oncogenesis [ 32 ].…”

STPP-UP: An alternative method for drug target identification using protein thermal stability

“…S2 A ). To determine the optimal combination of T max and ramp rate for STPP-UP experiments, we analyzed public TPP datasets ( 7 , 8 , 9 , 10 ) to determine the average T m-50 , which is the melting temperature at which 50% of the protein is denatured relative to the lowest temperature. The average T m-50 is around 51 °C for mammals and is stable between species ( Fig.…”

“…B , boxplots showing the average Tm-50 in mouse, rat, and human cells. Data were taken from ( 7 , 8 , 9 , 10 ). Tm data were filtered for being present in all replicates and between 37 °C and 67 °C.…”