Fibroblast growth factor receptor 1–4 (FGFR1–4)

Fibroblast growth factor receptor 1–4 (FGFR1–4) are a family of highly conserved cell surface receptor tyrosine kinases essential for development, tissue maintenance, and cellular signaling. Each receptor comprises an extracellular region featuring three immunoglobulin-like domains responsible for ligand binding, a single transmembrane helix, and an intracellular tyrosine kinase domain. Upon binding fibroblast growth factors (FGFs), these receptors dimerize, undergo autophosphorylation, and activate signaling pathways such as PI3K/AKT, MAPK, and STAT. FGFRs regulate numerous biological functions, including cell division, differentiation, migration, survival, angiogenesis, and tissue repair. Aberrations in FGFR1–4 (mutations, fusions, amplifications) are implicated in diverse developmental syndromes and several cancers, making them important therapeutic targets. Multiple selective FGFR inhibitors have been developed and approved for specific FGFR-driven malignancies. Therapeutic challenges include on-target toxicities, resistance mechanisms, and the need for biomarker-driven patient selection [1][2][6][8].

Other names

FGFR1FGFR2FGFR3FGFR4Fibroblast growth factor receptor family

Inhibition of tyrosine kinase activity: Small-molecule inhibitors and antibody drugs bind the intracellular kinase domain, blocking downstream signaling pathways (e.g., PI3K/AKT, MAPK, STAT) to suppress cancer cell proliferation and survival [1][6] - Ligand trap: Some agents act as decoy receptors that sequester FGFs, preventing activation of FGFRs