Recombinant prostate specific antigen inhibits angiogenesis in vitro and in vivo

Prostate. 2003 Aug 1;56(3):212-9. doi: 10.1002/pros.10256.


Background: Prostate specific antigen (PSA) is a kallikrein family member with serine protease activity commonly used as a diagnostic marker for prostate cancer. We recently described anti-angiogenic properties of PSA [Fortier et al.: JNCI 91:1635-1640].

Methods: Two forms of PSA were cloned and expressed in Pichia pastoris: one, an intact PSA with an N-terminus of IVGGVS em leader; the second, an N-1 PSA variant. The recombinant proteins were tested for serine protease activity and for anti-angiogenic activity in vitro and in vivo.

Results: The rate of substrate hydrolysis by the intact recombinant PSA was similar to that of PSA isolated and purified from human seminal plasma. In contrast, the N-1 PSA variant lacked serine protease activity. In an endothelial cell migration assay, the concentration that resulted in 50% inhibition (IC(50)) was: 0.5 microM for native PSA, 0.5 microM for intact recombinant protein, and 0.1 microM for the N-1 variant PSA. Both the intact recombinant and the N-1 recombinant PSA inhibited angiogenesis in vivo.

Conclusions: Purified recombinant PSA inhibits angiogenesis, proving the concept that PSA is an anti-angiogenic, and serine protease activity, as determined by synthetic substrate hydrolysis, is distinct from the anti-angiogenic properties of PSA.

MeSH terms

  • Angiogenesis Inhibitors / pharmacology
  • Endothelial Growth Factors / pharmacology
  • Humans
  • Hydrolysis
  • Intercellular Signaling Peptides and Proteins / pharmacology
  • Lymphokines / pharmacology
  • Male
  • Neovascularization, Pathologic*
  • Pichia / genetics
  • Plasmids
  • Polymerase Chain Reaction
  • Prostate-Specific Antigen / pharmacology*
  • Recombinant Proteins
  • Serine Endopeptidases / pharmacology
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors


  • Angiogenesis Inhibitors
  • Endothelial Growth Factors
  • Intercellular Signaling Peptides and Proteins
  • Lymphokines
  • Recombinant Proteins
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors
  • Serine Endopeptidases
  • Prostate-Specific Antigen