NCI Drug Dictionary

The NCI Drug Dictionary contains technical definitions and synonyms for drugs/agents used to treat patients with cancer or conditions related to cancer. Each drug entry includes links to check for clinical trials listed in NCI's List of Cancer Clinical Trials.

tumor-homing peptide iRGD
A 9-amino-acid-based cyclic, tumor specific homing, arginine-glycine-aspartic acid (RGD)-based peptide (CRGDKRGPDC), with tumor penetrating activity. The iRGD contains the RGD motif as well as the C-terminal end binding (CendR) motif that increases internalization. Upon administration, the RGD motif of the iRGD peptide is able to specifically target tumors by binding to alphavbeta3/alphavbeta5 integrins on tumor endothelium. In turn, iRGD is cleaved by specific tumor proteases, which exposes the positively charged CendR motif. This motif binds to neuropilin-1 (NRP-1), a receptor overexpressed on certain tumor cells. This increases vascular permeability of tumor blood vessels and promotes tumor penetration. Compared to other RGD peptides, this agent is able to both improve delivery and increase the accumulation of co-administered or conjugated chemotherapeutic agents in the tumor. Check for active clinical trials using this agent. (NCI Thesaurus)