title: Enzymatic activity of free-prostate-specific antigen (f-PSA) is not required for some of its physiological activities.
abstract: BACKGROUND
  Prostate specific antigen (PSA) is a well known biomarker for early diagnosis and management of prostate cancer. Furthermore, PSA has been documented to have anti-angiogenic and anti-tumorigenic activities in both in vitro and in vivo studies. However, little is known about the molecular mechanism(s) involved in regulation of these processes, in particular the role of the serine-protease enzymatic activity of PSA.
  
  
  METHODS
  Enzymatic activity of PSA isolated directly from seminal plasma was inhibited specifically (>95%) by incubation with zinc2+ . Human umbilical vein endothelial cells (HUVEC) were utilized to compare/contrast the physiological effects of enzymatically active versus inactive PSA.
  
  
  RESULTS
  Equimolar concentrations of enzymatically active PSA and PSA enzymatically inactivated by incubation with Zn2+ had similar physiological effects on HUVEC, including inhibiting the gene expression of pro-angiogenic growth factors, like VEGF and bFGF, and up-regulation of expression of the anti-angiogenic growth factor IFN-γ; suppression of mRNA expression for markers of blood vessel development, like FAK, FLT, KDR, TWIST-1; P-38; inhibition of endothelial tube formation in the in vitro Matrigel Tube Formation Assay; and inhibition of endothelial cell invasion and migration properties.
  
  
  CONCLUSIONS
  Our data provides compelling evidence that the transcriptional regulatory and the anti-angiogenic activities of human PSA are independent of the innate enzymatic activity.
authors: Department of Molecular & Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York 14263, USA. Kailash.chadha@roswellpark.org
authors: Kailash C
authors: KC
authors: Chadha
authors: Bindukumar B
authors: BB
authors: Nair
authors: Srikant
authors: S
authors: Chakravarthi
authors: Rita
authors: R
authors: Zhou
authors: Alejandro
authors: A
authors: Godoy
authors: James L
authors: JL
authors: Mohler
authors: Ravikumar
authors: R
authors: Aalinkeel
authors: Stanley A
authors: SA
authors: Schwartz
authors: Gary J
authors: GJ
authors: Smith
mesh_terms: D002402:Cathepsin D / Q000096:biosynthesis / Q000235:genetics; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D051417:Focal Adhesion Kinase 1 / Q000096:biosynthesis / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D008297:Male; D018919:Neovascularization, Physiologic; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics; D011467:Prostate / Q000201:enzymology*; D017430:Prostate-Specific Antigen / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051879:Twist-Related Protein 1 / Q000096:biosynthesis / Q000235:genetics; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000096:biosynthesis / Q000235:genetics; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000096:biosynthesis / Q000235:genetics; D015032:Zinc / Q000494:pharmacology
chemical_list: D009687:Nuclear Proteins; D012333:RNA, Messenger; C103173:TWIST1 protein, human; D051879:Twist-Related Protein 1; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2; C501162:FLT1 protein, human; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human; D017430:Prostate-Specific Antigen; D002402:Cathepsin D; D015032:Zinc