Prodrugs that are triggered by cancer biomarkers are attractive because of their potential to be activated preferentially in cancer cells thereby reducing the serious adverse effects associated with conventional chemotherapy. While numerous cancer biomarkers have been discovered, prodrugs triggered by enzymes have been the main focus because enzymes can activate prodrugs via covalent transformations. Thus, a barrier exists in using non-enzyme biomarkers for prodrug-activation because of our poor understanding of how to develop molecules that selectively recognize, and are activated by, biomarkers that cannot facilitate covalent transformations. The existence of this knowledge gap hinders the full scope of prodrugs that can be developed. Thus the long-term vision of this project is to generate non-covalently triggered prodrugs. The objective of this basic-science application, which is a seminal step in achieving our long term goal, is to establish fundamental supramolecular mechanisms for the non-covalent activation of protein inhibitors by microRNA-21 (miR-21), a highly deregulated, oncogenic, miR. The central hypothesis of this application, which we will test via two complementary design strategies (Aim 1 and 2, respectively), is that miR-21 inducible protein antagonists can be achieved by developing DNA-small molecule chimeras (DCs), that undergo a structural switch from a de-activated conformation to an activated state upon binding sequence specifically to miR-21.
The specific aims for this project are to develop, (Aim 1) hairpin-forming DCs de-activated by host/guest interactions and (Aim 2) bidentate DCs de-activated via duplex formation with a guide strand, as miR-21 responsive inhibitors of clinically relevant carbonic anhydrase-II (CA-II). In both aims, we will synthesize and characterize the respective DC systems and will probe their ability to undergo miR-21 induced structure-switching to an activated state via a number of spectroscopic experiments (including UV-vis and fluorescence quenching). Subsequently, the differential ability of the de-activated and active DC conformations to inhibit CA-II will be evaluated (via a colorimetric esterase assay). After optimization of the structure of the DC systems (including enhancing CA-II binding and nuclease resistance), we will transfect DCs into cell-lines over expressing (and control cell-lines under expressing) miR-21 and probe CA-II inhibition-derived cell growth arrest. This proposal is innovative because it develops the first examples of activating protein inhibitors in response to miRs. Further, this project will provide impetus to shift general research into examining non- covalent mechanisms for prodrug activation. This work is significant because (a) it is a seminal step in a continuum of research aimed, in the long-term, at developing miR-21 triggered prodrugs, and (b) it will exert a sustained influence on the field of supramolecular chemistry by enhancing our understanding of how key principles of molecular recognition (such as host/guest interactions and multivalency) in combination with DNA assembly and structure-switching phenomena can be used to develop dynamic protein-binders. )

Public Health Relevance

This proposal is relevant to public health because fundamental studies on protein inhibitors that are triggered by oncogenic microRNA-21 has the potential to lead to prodrugs that selectively target cancer cells, thereby attenuating the systemic adverse effects and poor patient outcomes endemic to conventional chemotherapy. Thus, the proposed research is particularly relevant to the mission of the NIH that pertains to reducing the burden of illness. )

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Synthetic and Biological Chemistry A Study Section (SBCA)
Program Officer
Fabian, Miles
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Tulane University
Schools of Arts and Sciences
New Orleans
United States
Zip Code
Zhou, Xiao; Su, Xiaoye; Pathak, Pravin et al. (2017) Host-Guest Tethered DNA Transducer: ATP Fueled Release of a Protein Inhibitor from Cucurbit[7]uril. J Am Chem Soc 139:13916-13921
Aryal, Gyan Hari; Battle, Cooper Hawkins; Grusenmeyer, Tod A et al. (2016) A naphthalimide derived fluorescent sensor for solid-phase screening of cucurbit[7]uril-guest interactions. Chem Commun (Camb) 52:2307-10
Chu, Xiaozhu; Battle, Cooper H; Zhang, Nan et al. (2015) Bile Acid Conjugated DNA Chimera that Conditionally Inhibits Carbonic Anhydrase-II in the Presence of MicroRNA-21. Bioconjug Chem 26:1606-12
Su, Xiaoye; Zhou, Xiao; Zhang, Nan et al. (2015) A stable bidentate protein binder achieved via DNA self-assembly driven ligand migration. Chem Commun (Camb) 51:13615-8
Zhuang, Yan; Nguyen, Hong T; Burow, Matthew E et al. (2015) Elevated expression of long intergenic non-coding RNA HOTAIR in a basal-like variant of MCF-7 breast cancer cells. Mol Carcinog 54:1656-67
Loewen, Gregory; Jayawickramarajah, Janarthanan; Zhuo, Ying et al. (2014) Functions of lncRNA HOTAIR in lung cancer. J Hematol Oncol 7:90
Zhang, Hong; Zhang, Boyu; Zhu, Mengyuan et al. (2014) Water-soluble porphyrin nanospheres: enhanced photo-physical properties achieved via cyclodextrin driven double self-inclusion. Chem Commun (Camb) 50:4853-5
Loewen, Gregory; Zhuo, Ying; Zhuang, Yan et al. (2014) lincRNA HOTAIR as a novel promoter of cancer progression. J Can Res Updates 3:134-140
Su, Xiaoye; Kuang, Li; Battle, Cooper et al. (2014) Mild two-step method to construct DNA-conjugated silicon nanoparticles: scaffolds for the detection of microRNA-21. Bioconjug Chem 25:1739-43
Battle, Cooper; Chu, Xiaozhu; Jayawickramarajah, Janarthanan (2013) Oligonucleotide-Based Systems for Input-Controlled and Non-Covalently Regulated Protein-Binding. Supramol Chem 25:

Showing the most recent 10 out of 11 publications