Enhanced delivery of site-specific DNA damaging toxins to prostate cancercells

University Of North Carolina Wilmington, Wilmington NC

Investigators

Abstract

ABSTRACT The overall goal of our research is to develop a dependable strategy for selectively targeting different cancer cells and producing specific types of DNA-damage in them, leading to their targeted destruction. These molecules will help us understand DNA-damage mediated biological processes in cancer cells and lay the foundation for advances in disease treatment. The objective of this R15 proposal is to develop molecules that target prostate cancer (PCa) cells and cause clustered DNA damage within them leading to the formation of lethal DNA double strand breaks (DSBs). This project addresses the current critical need in PCa treatment to develop new chemotherapy agents with higher selectivity and potency but without toxic side-effects. Our strategy is to synthesize molecules that bind to the androgen receptor (AR), which is overexpressed in PCa cells, get escorted to the nucleus of these cells by AR action, and generate predominantly N3-methyladenine (3MeA) DNA adducts in close proximity. Cellular processing of these closely spaced DNA lesions will lead to the formation DNA DSBs. This approach is partially based upon our successful targeted destruction of breast cancer cells using molecules that bind to estrogen receptors (ERs) which are overexpressed in many breast cancers. We hypothesize that our strategy will lead to the targeted, potent destruction of PCa cells due to the lethal nature of DNA DSBs and because the AR and ER belong to the same superfamily of nuclear receptors and function similarly. We will test our hypothesis and attain the objective of this application by pursuing the following specific aims: (1) Synthesize molecules that can bind to androgen receptors and can form closely spaced 3MeA adducts, (2) Characterize the DNA-binding, DNA-methylating, and membrane permeability properties of the molecules, (3) Investigate the selectivity of the molecules for PCa cells overexpressing the AR and determine the role of AR in the observed toxicity, and (4) Examine the mechanism by which cellular toxicity is induced by the molecules in the PCa cells. The major outcome of our project will be the creation of molecules that can target PCa cells and form lethal DNA damage in them. These molecules will be used to probe AR- mediated delivery of toxins to DNA, investigate consequences of 3MeA and clustered adduct formation in PCa cells, and pave the way for future studies in animal models of PCa. This project will have a significant positive impact on the development of a new class of site-specific DNA-damaging agents that target specific cells and form DNA DSBs and lead to the development of targeted cancer chemotherapy agents with fewer side-effects. Another important outcome will be training of multiple undergraduate students, including underrepresented minorities, in organic synthesis, bioorganic and molecular biology techniques, tissue culture, and performing analytical and biological assays, thus providing them with advanced training in biomedical research and serving to enhance the biomedical research workforce.