Platelet-derived growth factor receptor and c-Kit receptor tyrosine kinase (PDGFR and c-Kit (KIT))

Platelet-derived growth factor receptor (PDGFR) and c-Kit receptor tyrosine kinase (KIT, also known as CD117) are members of the type III receptor tyrosine kinase family involved in regulating cell proliferation, migration, and survival[1][4][6]. PDGFR exists as alpha and beta isoforms and primarily mediates responses to platelet-derived growth factors (PDGFs), while c-Kit is the receptor for stem cell factor (SCF) and plays key roles in hematopoiesis, pigmentation, and fertility[1][2][5]. Both receptors are activated by ligand-induced dimerization, leading to autophosphorylation of intracellular tyrosine residues and activation of downstream signaling pathways, such as the PI3K/AKT and MAPK pathways[1][2][4]. Aberrant activation due to mutations, overexpression, or gene fusions is implicated in malignancies, including gastrointestinal stromal tumors, acute myeloid leukemia, melanoma, and others[1][3][5][6]. These receptors are validated targets for cancer therapy; numerous tyrosine kinase inhibitors, as well as monoclonal antibodies, have been developed for treatment of tumors driven by dysregulated PDGFR or c-Kit signaling[3][6]. Monitoring for resistance and adverse effects—such as myelosuppression and liver toxicity—is essential in the therapeutic setting[6].

Other names

PDGFR (covers PDGF receptor alpha and beta subtypes)CD117 (for c-Kit)KIT (for c-Kit)Mast/stem cell growth factor receptor (for c-Kit)SCFR (stem cell factor receptor; for c-Kit)

Tyrosine kinase inhibition (blocks kinase activity, preventing downstream signaling) Antibody-mediated inhibition (monoclonal antibodies target extracellular domain/inhibit receptor) Antibody-drug conjugates