Transforming growth factor beta signaling complex (TGF-β signaling complex)

The Transforming growth factor beta (TGF-beta) signaling complex is a pivotal regulator of cellular homeostasis, encompassing three ligand isoforms (TGF-beta1, 2, and 3) and their associated transmembrane receptors (Massagué, 2012, PMID: 22917478). Signaling is initiated when a TGF-beta dimer binds to the type II receptor (TGFBR2), which then recruits and phosphorylates the type I receptor (TGFBR1/ALK5), triggering a downstream cascade primarily mediated by SMAD proteins (Derynck & Zhang, 2003, PMID: 14555996). This complex plays a dual role in oncology: it acts as a tumor suppressor in early-stage disease by inducing cell cycle arrest, but transitions to a pro-tumorigenic factor in advanced stages by promoting metastasis and immune suppression (Batlle & Massagué, 2019, PMID: 31700174). Beyond cancer, the complex is a master regulator of the myofibroblast phenotype, making it a central driver in fibrotic diseases of the lung, liver, and kidney (Meng et al., 2016, PMID: 27869164). Therapeutic interventions targeting this complex include neutralizing antibodies like fresolimumab, small molecule kinase inhibitors like galunisertib, and bifunctional fusion proteins such as bintrafusp alfa (Teicher, 2021, PMID: 33762315). Clinical development has faced challenges due to the pleiotropic nature of TGF-beta, which can lead to significant side effects such as cardiotoxicity and the development of benign skin tumors (Anderton et al., 2011, PMID: 21421915).

Other names

TGF-beta signaling pathwayTGFB signaling complexTGF-beta ligand-receptor complexTGF-beta/SMAD signaling axis

Inhibition of TGF-beta ligands via neutralizing antibodies, blockade of TGF-beta type I receptor (ALK5) kinase activity, or sequestration of ligands using decoy receptors and bifunctional fusion proteins.