Landscape Phage Probes for Prostate Specific Antigen

Abstract

Prostate‐specific antigen (PSA) is a cardinal marker for molecular diagnosis and proper management of prostate tumors. Therefore, development of specific probes for this marker is paramount for precise molecular diagnosis and targeted delivery of therapeutics to prostate cancer cells. Screening of the multibillion landscape libraries proffers a simple and economic approach for isolating target‐specific phage probes. Landscape phage libraries are collections of filamentous phages displaying random guest peptides on all 4,000 surface domains of the major coat protein. They serve as a rich source of bioselective materials that can be used in different areas of technology and medicine, including gene delivery, drug delivery and imaging of tumor cells. Novel highly specific and selective phage probes against prostate specific antigens were selected from 8‐mer library using immobilized PSA as targets. The selected clones were identified by nucleotide sequencing of their DNA and translation into proteins using software. Eight phage probes were isolated and tested for their selective interactions with PSA in comparison with control targets, two of the phage probes selectively interacted with PSA. The selected phage probes can serve as promising ligands for development of imaging and therapeutic devices precisely targeted to prostate tumors.