Phage display selection of peptides that affect prostate carcinoma cells attachment and invasion.
BACKGROUND
Prostate cancer-specific proteins must be identified to serve as diagnostic and prognostic markers. Cell surface proteins are especially important, because they have potential utility as diagnostic markers and therapeutic targets. Identification of ligands for these proteins will allow use of these ligands as diagnostic and therapeutic tools and permit the investigation of receptor function. We performed a search for peptide ligands to prostate cancer cell-specific receptors.


METHODS
Peptide phage display library was used to isolate specific ligands to LNCaP prostate carcinoma cells receptors. Selected phage and cognate peptides were investigated for their cancer-related functions, such as the ability to interfere with cell adhesion, spreading, motility, and invasion.


RESULTS
Phage designated pg35, blocked spreading of LNCaP cells and their derivatives C4-2 and C4-2b. Cognate peptide did not inhibit spreading, but incubation of C4-2 and C4-2b cells with cognate peptide increased their affinity for endothelial cells and invasiveness. In addition, the peptide activates matrix metalloproteinase (MMP)-2 and 9 in C4-2 and C4-2b cells.


CONCLUSIONS
These results indicate that identified ligands may play a role in tumorigenicity and metastatic transformation of prostate cancer. To our knowledge, this is the first identification of a functional cancer-specific peptide ligand using the phage display approach.
Romanov
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VI
Department of Medicine, State University of New York at Stony Brook, Stony Brook, New York 11794, USA. vromanov@mail.som.sunysb.edu
Durand
D B
DB
Petrenko
V A
VA
D000595:Amino Acid Sequence; D000818:Animals; D001435:Bacteriophages / Q000378:metabolism; D002277:Carcinoma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D002633:Chemotaxis / Q000502:physiology; D004586:Electrophoresis; D004727:Endothelium / Q000502:physiology; D004789:Enzyme Activation; D006801:Humans; D008024:Ligands; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000378:metabolism / Q000494:pharmacology* / Q000502:physiology; D019151:Peptide Library; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014407:Tumor Cells, Cultured
D008024:Ligands; D009363:Neoplasm Proteins; D019151:Peptide Library; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9