Vascular biology: Edited by Thomas F. DeuelEndothelial–stromal interactions in angiogenesisHughes, Christopher CWAuthor Information Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, California, USA Correspondence to Christopher C.W. Hughes, PhD, Department of Molecular Biology and Biochemistry, McGaugh Hall, University of California Irvine, Irvine, CA 92697, USA Tel: +1 949 824 8771; fax: +1 949 824 8551; e-mail: firstname.lastname@example.org Current Opinion in Hematology: May 2008 - Volume 15 - Issue 3 - p 204-209 doi: 10.1097/MOH.0b013e3282f97dbc Buy Metrics Abstract Purpose of review Angiogenesis often occurs in the context of a wound or tumor stroma. This review will focus on the recent findings on the interactions between angiogenic endothelial cells and the other components of the stroma – fibroblasts, pericytes and extracellular matrix. Recent findings Large-scale gene expression arrays have provided a remarkable insight into the diversity of fibroblasts in different tissues and under different conditions. These somewhat neglected cells are now understood to play a critical role in tumor growth, regulating not only the phenotype of the tumor cells but also the angiogenic response that supports them. These advances are leading to an understanding of the soil and seed hypothesis at the molecular level. In addition, there is a new focus on the role of pericytes in regulating angiogenesis and their potential as targets for tumor therapy. Summary Initiation of new blood vessel formation requires metalloproteinase induction leading to the degradation of the basement membrane, sprouting of endothelial cells and regulation of pericyte attachment. Fibroblasts and their activated counterpart, the myofibroblast, play a large role in synchronizing these events through the expression of numerous extracellular matrix molecules, growth factors and morphogens, including fibroblast growth factors and transforming growth factor beta. © 2008 Lippincott Williams & Wilkins, Inc.