MECHANISMS AND CYTOTOXIC EFFECTS OF NQO1-DIRECTED LAVENDAMYCIN DERIVATIVES AND MITOCHONDRIA-TARGETED ANTHRACENYL ISOXAZOLE AMIDES AS NOVEL ANTITUMOR AGENTS

Cancer is a common, complex, and oftentimes fatal disease. Despite extensive research in the field of cancer drug discovery, there are still improvements to be made in the design of effective anticancer agents. This project involved three separate but related studies that fall under the category of anticancer drug discovery as a whole. The overall goal of this project was to design and investigate the mechanisms of action of new antitumor agents to be used against solid tumors. First, we developed a series of anthracenyl isoxazole amides (AIMs) designed to bind to G-quadruplex DNA and inhibit telomerase. Results from this study demonstrated an alternative mitochondrial mechanism of action of the AIMs not yet fully described in the literature. Investigation of lead compound AIM 1 showed localization of the AIM in mitochondria with resulting induction of apoptosis, generation of mitochondrial superoxide, disruption of mitochondrial membrane potential, and activation of caspase-9. The second goal of this project was to assay a series of 4-isoxazolyl-1,4-dihydropyridines (IDHPs) that function as P-gp inhibitors to determine their contribution to enhanced cytotoxicity of the AIMs when co-dosed together in vitro. Because so many anticancer agents are substrates for P-gp and are therefore limited in their ability to reach intended targets, the development of P-gp inhibitors is an important area of research. Results from this study indicate that IDHPs are a viable class of P-gp inhibitors that can be co-dosed with P-gp substrates to increase substrate cytotoxicity. The third goal of this study was to determine the NQO1 substrate potential of a series of lavendamycin derivative quinolinequinones and assess their corresponding antitumor potential. Surprisingly, few of the quinolinequinones tested showed preferential specificity for NQO1-expressing cells compared to NQO1-null cells. However, in our series of aryl-substituted quinolinequinones, the active molecules appear to be the quinone derivatives and not derivatives of hydroquinones or semiquinones. These data suggest a mode of action that differs from that of previously studied lavendamycin analogues that are activated by NQO1 reduction. While this project focused on the general targeting of solid tumors, the type of tumor explicitly studied varied from brain cancer to breast cancer and encompassed multiple drug targets. Collectively the results of this study are expansive and offer much to the field of anticancer drug discovery

Anthracenyl isoxazole amides (AIMs) stabilize quadruplex DNA structures in telomeric and c-MYC promotor sequences

Approximately 23,000 people are affected by malignant brain and CNS tumors in the United States each year and those afflicted have a median survival rate of only 12–15 months due to the limited treatment options available. The anthracenyl isoxazole amides (AIMs) are a novel class of compounds that have been shown to possess significant anti tumor activity in the NCI 60 cell line panel and to inhibit growth of SNB-19 glioblastoma cells at low micromolar and nanomolar concentrations. The goal of our current research is to characterize the mechanism underlying the anti tumor activity of the AIMs. We hypothesize the mechanism of growth inhibition to involve binding and stabilization of a DNA tertiary structure known as a guanine quadruplex. Various regulatory regions of DNA, such the c-MYC oncogene promoter sequence and repeating sequences formed at the end of telomeres, adopt the quadruplex conformation. Stabilization of quadruplex structures by small-molecule binding ligands has been reported to modulate the expression of genes and inhibit telomerase activity. Down-regulation of certain oncogenes or the inhibition of telomerase can cause tumor cells to undergo apoptosis or become unable to efficiently replicate. To establish whether interactions between the AIMs and quadruplex-forming sequences act to stabilize the quadruplex tertiary structure, circular dichroism spectroscopy (CD) was employed. CD is a method that utilizes the differential absorbance of left and right circularly polarized light to examine the chiral structure of molecules. CD thermal melting studies were conducted to determine whether the AIMs would increase the melting temperature of quadruplex forming sequences as an indication of increased stability. Our results demonstrated the AIMs, at two equivalents, increase the melting temperature (Tm) of both the c-MYC promoter and telomeric sequences by approximately 2–3 °C with strong statistical significance and reproducibility. Utilizing CD allows the use of low micromolar concentrations of DNA and this method will be used in the future to rapidly develop additional structure-activity relationships between novel AIMs and quadruplex forming sequences. Our laboratory has also shown chemical shifts in the imino region upon treatment with the AIMs for both the c-MYC promotor and telomeric sequence by NMR, providing additional evidence of the AIMs interaction with quadruplex structures. Interestingly, fluorescence microscopy of SNB-19 cells treated with AIMs show their localization is primarily in the mitochondria, and mitochondrial DNA contains several other important quadruplex forming sequences. Mitochondrial-dependent apoptosis has been suggested for other quadruplex binding ligands and therefore our future work will examine the potential stabilization of mitochondrial quadruplexes by these and other novel AIMs

Deep Underground Neutrino Experiment (DUNE), Far Detector Technical Design Report, Volume I Introduction to DUNE

International audienceThe preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. This TDR is intended to justify the technical choices for the far detector that flow down from the high-level physics goals through requirements at all levels of the Project. Volume I contains an executive summary that introduces the DUNE science program, the far detector and the strategy for its modular designs, and the organization and management of the Project. The remainder of Volume I provides more detail on the science program that drives the choice of detector technologies and on the technologies themselves. It also introduces the designs for the DUNE near detector and the DUNE computing model, for which DUNE is planning design reports. Volume II of this TDR describes DUNE's physics program in detail. Volume III describes the technical coordination required for the far detector design, construction, installation, and integration, and its organizational structure. Volume IV describes the single-phase far detector technology. A planned Volume V will describe the dual-phase technology

Deep Underground Neutrino Experiment (DUNE), Far Detector Technical Design Report, Volume II: DUNE Physics

The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay -- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. DUNE is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. Volume II of this TDR, DUNE Physics, describes the array of identified scientific opportunities and key goals. Crucially, we also report our best current understanding of the capability of DUNE to realize these goals, along with the detailed arguments and investigations on which this understanding is based. This TDR volume documents the scientific basis underlying the conception and design of the LBNF/DUNE experimental configurations. As a result, the description of DUNE's experimental capabilities constitutes the bulk of the document. Key linkages between requirements for successful execution of the physics program and primary specifications of the experimental configurations are drawn and summarized. This document also serves a wider purpose as a statement on the scientific potential of DUNE as a central component within a global program of frontier theoretical and experimental particle physics research. Thus, the presentation also aims to serve as a resource for the particle physics community at large