Novel targeted system to deliver chemotherapeutic drugs to EphA2-expressing cancer cells.

The efficacy of anticancer drugs is often limited by their systemic toxicities and adverse side effects. We report that the EphA2 receptor is overexpressed preferentially in several human cancer cell lines compared to normal tissues and that an EphA2 targeting peptide (YSAYPDSVPMMS) can be effective in delivering anticancer agents to such tumors. Hence, we report on the synthesis and characterizations of a novel EphA2-targeting agent conjugated with the chemotherapeutic drug paclitaxel. We found that the peptide-drug conjugate is dramatically more effective than paclitaxel alone at inhibiting tumor growth in a prostate cancer xenograft model, delivering significantly higher levels of drug to the tumor site. We believe these studies open the way to the development of a new class of therapeutic compounds that exploit the EphA2 receptor for drug delivery to cancer cells.