Novel Decapeptides that Bind Avidly and Deliver Radioisotope to Colon Cancer Cells

BACKGROUND The rapidly growing field of targeted tumor therapy often utilizes an antibody, sometimes tagged with a tumor-ablating material such as radioisotope, directed against a specific molecule. METHODOLOGY/PRINCIPAL FINDINGS This report describes the discovery of nine novel decapeptides which can be radioactively labeled, bind to, and deliver (32)P to colon cancer cells. The decapeptides vary from one another by one to three amino acids and demonstrate vastly different binding abilities. The most avidly binding decapeptide can permanently deliver very high levels of radioisotope to the adenocarcinoma cancer cell lines at an efficiency 35 to 150 times greater than to a variety of other cell types, including cell lines derived from other types of cancer or from normal tissue. CONCLUSIONS/SIGNIFICANCE This experimental approach represents a new example of a strategy, termed peptide binding therapy, for the potential treatment of colorectal and other adenocarcinomas.