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.