Stromal PDGF receptors as prognostic and predictive biomarkers

Abstract

The PDGF family of growth factors exerts important regulatory functions on mesenchymal cells such as fibroblasts, vascular smooth muscle cells, and pericytes. Through activation of the tyrosine kinase PDGF alpha- and beta-receptors, these growth factors stimulate proliferation and migration of target cells and regulate their contractile capacity. PDGF receptors play major roles during development in settings of paracrine interactions between mesenchymal cells and epithelial or endothelial cells. The focus of this review is a discussion of experimental and correlative studies which have explored the biological mechanisms and clinical significance of PDGF receptors in mesenchymal cells of the tumor microenvironment. Collectively these studies identify the PDGF system as critical regulators of tumor growth, metastasis, and drug efficacy. Continued efforts in this field have the potential to advance stromal PDGF receptors to a state of clinically implemented biomarkers and therapeutic targets in selected patient populations.