Vascular progenitor cell and extracellular matrix protein interactions in cancer

Abstract

Vascular progenitor cells (VPCs) facilitate angiogenesis and vascular repair in damaged tissues where inflammatory cytokines coordinate healing through VPC mobilization. VPCs also facilitate tumor angiogenesis and induce angiogenic switching in metastatic sites. VPC binding to extracellular matrix proteins enriched in injured healing tissues and metastatic sites and the participation of integrins in this binding was investigated. VPC binding profiles on fibronectin and laminin of "healthy" controls was different from those of "cancer" patients and patients with acute tissue damage. Specific integrin-mediated binding of cells in VPC clusters were matrix protein-dependent. Patients with oral cancer and lymphoma had elevated plasma vascular endothelial growth factor (VEGF) levels compared to healthy controls. VEGF facilitated VPC clustering on fibronectin and incubating cells from healthy controls with VEGF switched binding profiles from "healthy" to "cancer". This study provided new insights regarding VPC-matrix interactions that help distinguish VPC involvement in vascular repair from vascular-mediated metastasis.