Synthesis and Application of the Doxaz-MARCKS Prodrug

Chemotherapeutic prodrugs have demonstrated success in killing cancer cells; however they also pose harm to healthy cells. The objective of this project was to synthesize an improved prodrug that is selectively activated only in the cancer microenvironment, thus minimally affecting healthy tissue. A photolabile linker was hypothesized to achieve said objective. The Yin group discovered that the MARCKS-ED peptide can localize to the exosome via curvature sensing and electrostatic interactions. In addition, the Koch group determined that Doxazolidine (Doxaz) is more cytotoxic than its clinical drug precursor. Also, no cancer cell lines have shown resistance to this anthracycline. Based on these studies, we decided to synthesize a prodrug containing a photolabile linker, MARCKS-ED peptide, and the Doxaz anthracycline. We hypothesized that a specific sequence of synthesis and purification steps would generate the prodrug. We carried out steps and characterized the products using NMR, HPLC and ESI-MS. The results confirmed that the desired product was produced. It was then predicted that application of UV light will activate the prodrug and cause cell death. IC50 values determined that application of UV light after prodrug incubation significantly decreased cell viability in comparison to cells retained in the dark. Further experiments are needed to verify the mechanism of the prodrug and ensure its efficacy in-vivo. Nonetheless, these results suggest that Doxaz-MARCKS will serve as a pragmatic chemotherapeutic.