Peptides have many advantages for targeted-cancer therapies, due to their small size, tissue and cell permeability, stability and low immunogenicity. For cancer applications, specific peptides are identified that can either bind to agents that will penetrate cancer cells to facilitate gene therapy, or alternatively bind specifically to cancer cells or supporting cells to inhibit their function.
A bottleneck for the use of gene therapy as a cancer-treatment strategy is the inherent inability of large, anionic molecules, such as siRNA, to pass through the cell membrane. Conjugating these molecules to cell-penetrating peptides can improve transfection and target oncogenes such as Bcl-2. Peptide libraries can be used to identify the most appropriate peptide for siRNA delivery, since the formation of this siRNA-peptide complex is dependent on the peptide sequence.
Another challenge in cancer research, specifically in therapeutics development, is targeting the therapy specifically to cancer cells. Without this specificity, therapeutics can be toxic to other non-cancerous cells, resulting in numerous undesirable side effects. A potential solution to this problem is to identify specific features unique to cancer cells, and develop therapeutics to target this feature. Since screening for these sites can be time consuming, and often difficult due to protein spatial constraints, peptide libraries have been used to span the sequence of the entire target epitope. Specific receptors or other cell surface proteins are purified and added to the library. The peptide with the highest binding affinity can then be identified. This process has been used to target multiple types of cells associated with cancer, such as cancer cells themselves and lymphocytes that promote cell proliferation.
AA Qadar et al. Peptide imprinted receptors for the determination of the small cell lung cancer associated biomarker progastrin releasing peptide. J Chromatogr A. 2014. Read more
D Smith et al. Patched targeting peptides for imaging and treatment of Hedgehog positive breast tumors. Biomed Res Int. 2014. Read moreMore publications citing GenScript's peptide and peptide library services
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