Small Molecule Chloropyramine Hydrochloride (C4) Targets the Binding Site of Focal Adhesion Kinase and Vascular Endothelial Growth Factor Receptor 3 and Suppresses Breast Cancer Growth in Vivo

Abstract

FAK is a tyrosine kinase that functions as a key orchestrator of signals leading to invasion and metastasis. Since FAK interacts directly with a number of critical proteins involved in survival signaling in tumor cells, we hypothesized that targeting a key protein-protein interface with druglike small molecules was a feasible strategy for inhibiting tumor growth. In this study, we targeted the protein-protein interface between FAK and VEGFR-3 and identified compound C4 (chloropyramine hydrochloride) as a drug capable of 1) inhibiting the biochemical function of VEGFR-3 and FAK, 2) inhibiting proliferation of a diverse set of cancer cell types in vitro, and 3) reducing tumor growth in vivo. Chloropyramine hydrochloride reduced tumor growth as a single agent, while concomitant administration with doxorubicin had a pronounced synergistic effect. Our data demonstrate that the FAK-VEGFR-3 interaction can be targeted by small drug-like molecules and this interaction can provide the basis for highly-specific novel cancer therapeutics.

How to awaken your nanomachines: Site-specific activation of focal adhesion kinases through ligand interactions

“…However developing highly specific ATP-competitive agents for FAK remains challenging, and PPIIs would provide an attractive novel tool for cancer therapy (Morelli et al, 2011). Several PPIIs were reported for FAK that showed anti-tumour activity in xenograft mouse models, and sensitised cancer cells to chemotherapy (Golubovskaya et al, , 2013(Golubovskaya et al, , 2008bHochwald et al, 2009;Kurenova et al, 2014Kurenova et al, , 2009. The proposed targets of those compounds are Y397, the reported p53 binding site on FERM, and the reported VEGFR-3 binding site on the FAT domain.…”

Design, synthesis, and biological evaluation of novel FAK scaffold inhibitors targeting the FAK–VEGFR3 protein–protein interaction

“…3c). 1 was used as a positive control based on previous reports [31]. Analog 7 was included as a negative control, since it showed no anti-proliferative activity in all cell lines used for screening (Fig.…”

“…Despite the numerous challenges encountered while developing inhibitors that target protein–protein interactions [30], in our previous efforts, we discovered small molecule 1 (chlorpyramine hydrochloride) (Fig. 1) which successfully binds and disrupts the FAK–VEGFR3 interaction [31]. Further testing with 1 showed reduction in tumor burden and neovascularization in mouse models of melanoma, breast cancer, pancreatic cancer [32], and glioblastoma.…”

Focal adhesion kinase-regulated signaling events in human cancer

“…A combination of a phage display strategy and in silico screen led to the identifi cation of a small molecule that could target the FAT domain (95,96) . This compound, chloropyramin hydrochloride [ N -(4-chlorobenzyl)-N 0, N 0-dimethyl-N -pyridin-2-ylethane-1,2-diamine], binds to the FAT domain and interacts with S939 and H1025.…”