title: Cellular abnormalities of blood vessels as targets in cancer.
abstract: Tumor blood vessels have multiple structural and functional abnormalities. They are unusually dynamic, and naturally undergo sprouting, proliferation, remodeling or regression. The vessels are irregularly shaped, tortuous, and lack the normal hierarchical arrangement of arterioles, capillaries and venules. Endothelial cells in tumors have abnormalities in gene expression, require growth factors for survival and have defective barrier function to plasma proteins. Pericytes on tumor vessels are also abnormal. Aberrant endothelial cells and pericytes generate defective basement membrane. Angiogenesis inhibitors can stop the growth of tumor vessels, prune existing vessels and normalize surviving vessels. Loss of endothelial cells is not necessarily accompanied by simultaneous loss of pericytes and surrounding basement membrane, which together can then provide a scaffold for regrowth of tumor vessels. Rapid vascular regrowth reflects the ongoing drive for angiogenesis and bizarre microenvironment in tumors that promote vascular abnormalities and thereby create therapeutic targets.
authors.affiliation: Cardiovascular Research Institute, Comprehensive Cancer Center, Department of Anatomy, University of California, San Francisco, CA 94143, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Baluk
authors.forename: Hiroya
authors.initials: H
authors.lastname: Hashizume
authors.forename: Donald M
authors.initials: DM
authors.lastname: McDonald
mesh_terms: D020533:Angiogenesis Inhibitors / Q000494:pharmacology; D000818:Animals; D001485:Basement Membrane / Q000187:drug effects; D001808:Blood Vessels / Q000002:abnormalities* / Q000166:cytology / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D006801:Humans; D009369:Neoplasms / Q000098:blood supply* / Q000188:drug therapy* / Q000473:pathology; D020286:Pericytes / Q000187:drug effects / Q000473:pathology / Q000502:physiology
chemical_list: D020533:Angiogenesis Inhibitors