Development of peptides as potential drugs for cancer therapy.

The development of more selective agents focused on targeted delivery of imaging probes and drugs to different tumor sites is the current trend in cancer diagnosis and therapies. Peptides are small amino acid sequences that can be isolated to bind to a predetermined target and are potentially capable of interfering with its function. These specific peptides isolated can inhibit individual signaling components, which are essential in cancer development and progression. Phage display is a powerful technology for selecting and cloning peptides displayed on the surface of bacteriophage. Billionclone-peptide libraries can be rapidly and simultaneously selected by phage biopanning, leading to large numbers of hits. Although peptides account for only a small part of current therapeutic agents, their potential is being improved by new technologies affecting their modification, delivery, stability and their application in preclinical settings. This review will highlight how to isolate peptides that target pivotal molecules in cancer development and progression through phage library biopanning and how to modify these peptides to enhance their anticancer efficacy.