title: Angiogenesis with pericyte abnormalities in a transgenic model of prostate carcinoma.
abstract: BACKGROUND
  Previous studies of the TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) model vasculature suggest that, as tumors develop, vessels invade the glandular epithelium. However, changes in the vasculature are difficult to study in conventional thin tissue sections. The authors used a new approach to characterize morphologic and architectural changes of blood vessels and pericytes during tumor development in TRAMP mice.
  
  
  METHODS
  Eighty-micron cryostat sections of normal prostate and three histopathologic stages of TRAMP tumor sections, classified by epithelial cell E-cadherin immunoreactivity, were immunostained with vascular endothelial cell and pericyte receptor antibodies and evaluated by confocal microscopy.
  
  
  RESULTS
  In the normal mouse prostate, capillaries were most abundant in the fibromuscular tunica between the epithelium and smooth muscle of the ductules. In the prostatic intraepithelial neoplasia (PIN) stage, vessels accompanied epithelial cell protrusions into the ductule lumen but remained in the connective tissue at the basal side of the epithelium. Well differentiated tissues had extensive angiogenesis with five times the normal mean vascularity outside ductules. Vessels were of variable diameter, were associated with an increased number of pericytes, and some had endothelial sprouts. Angiogenic blood vessels from poorly differentiated adenocarcinomas were tortuous, variable in caliber, and lacked the normal hierarchy. Pericytes on these vessels had an abnormal phenotype manifested by alpha-smooth muscle actin expression and loose association with endothelial cells. Angiogenesis and loss of vascular hierarchy were also found in human prostate carcinoma.
  
  
  CONCLUSIONS
  Vascular abnormalities, which begin at the PIN stage and intensify in well differentiated and poorly differentiated tumors, may be useful readouts for early detection and treatment assessment in prostate carcinoma.
authors.affiliation: Department of Anatomy, University of California at San Francisco, San Francisco, California 94143-0130, USA.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Ozawa
authors.forename: Virginia J
authors.initials: VJ
authors.lastname: Yao
authors.forename: Yvan H
authors.initials: YH
authors.lastname: Chanthery
authors.forename: Patricia
authors.initials: P
authors.lastname: Troncoso
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Uemura
authors.forename: Amanda S
authors.initials: AS
authors.lastname: Varner
authors.forename: Ian M
authors.initials: IM
authors.lastname: Kasman
authors.forename: Renata
authors.initials: R
authors.lastname: Pasqualini
authors.forename: Wadih
authors.initials: W
authors.lastname: Arap
authors.forename: Donald M
authors.initials: DM
authors.lastname: McDonald
mesh_terms: D000230:Adenocarcinoma / Q000098:blood supply* / Q000378:metabolism; D000818:Animals; D015820:Cadherins / Q000378:metabolism; D004195:Disease Models, Animal; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D009389:Neovascularization, Pathologic; D020286:Pericytes / Q000378:metabolism / Q000473:pathology*; D019048:Prostatic Intraepithelial Neoplasia / Q000098:blood supply* / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000098:blood supply* / Q000378:metabolism; D051381:Rats
chemical_list: D015820:Cadherins