The PhScN Peptide as a Potent Agent for Targeting Both Invasion and Survival and for Increasing Radiosensitivity in Human Prostate Cancer

Abstract

Purpose/Objectives(s): Metastatic invasion is caused by constitutive activation of the alpha5 beta1 integrin fibronectin receptor (FnR), and is blocked by the PHSCN peptide (Ac-PHSCN-NH2) in both preclinical models and in Phase 1 clinical trial. An endoproteinase-resistant derivative of Ac-PHSCN-NH2 was made by including D-isomers of Histidine and Cysteine to form the PhScN peptide: Ac-PhScN-NH2. Ac-PhScN-NH2 is a highly potent inhibitor of alpha5 beta1 integrin-mediated invasion and survival of human prostate cancer cells, both in vitro and in vivo.