This research will develop a new cancer-killing strategy by simultaneously targeting cancer-specific extracellular and intracellular cues for additional levels of specificity. Specifically, the investigators seek to develop a new generation of synthetic DNA devices that can be used for programmable intracellular reconstitution of a split suicide enzyme capable of activating a non-toxic prodrug into a toxic product for cancer killing. By combining these DNA devices with active extracellular targeting and exogenously applied, inactive prodrugs to trigger cell death, a higher degree of specificity for cancer cells can be achieved. Because each of these components can be independently designed to achieve the desired outputs, this strategy is highly tunable and can be customized for different cancer markers of interest. Educational impacts include graduate school workshops aimed at increasing enrollment of underrepresented students in graduate Chemical Engineering programs and summer internships for local high school students and teachers.
A major technological hurdle confronting cancer therapeutics is how to take advantage of cancer-specific markers to achieve targeted therapy. Active targeting of surface markers alone is inadequate and must be merged with additional layers of intracellular signals to provide a higher level of specificity. We propose to address this need by developing a transformative approach of prodrug therapy that senses both the extracellular and intracellular disease states in a complex cellular environment and actuates an appropriate, localized therapeutic response for cancer treatment. The central idea is to create multi-layer targeting, sensing, and responsive DNA-gated lock and key devices based on toehold-mediated strand displacement for programmable intracellular reconstitution of a split suicide enzyme capable of activating the prodrug deaminate 5-fluorocytosine (5-FC) into the toxic product 5-fluorouracil (5-FU). Extracellular targeting will be achieved by incorporating PEG-modified cell-targeting and endosomolytic peptides via site-specific conjugation with the alkyne and keto groups on two orthogonal unnatural amino acid residues. The integration of principles from protein engineering, synthetic biology, and drug delivery represents a truly multidisciplinary effort. Graduate students participating in this research will gain an integrated perspective of the important interfaces and synergies connecting biochemistry, protein engineering, material design, and drug delivery.
This award by the Biotechnology and Biochemical Engineering Program of the CBET Division is co-funded by the Systems and Synthetic Biology Program of the Division of Molecular and Cellular Biology.
