@article{fikes_srougi_2023, title={Design and Implementation of an Accessible and Open-Sourced <i>In Silico</i> Drug Screening Activity for Cancer Drug Discovery}, volume={100}, ISSN={["1938-1328"]}, url={https://doi.org/10.1021/acs.jchemed.3c00307}, DOI={10.1021/acs.jchemed.3c00307}, abstractNote={The application of chemistry concepts in biological settings plays an important role in the interdisciplinary field of drug discovery and development. This is true for molecular docking, where an understanding of intermolecular forces and noncovalent interactions is useful for rational drug design and development. Here we report the design and use of a molecular docking activity for cancer drug discovery for users that requires minimal coding knowledge. Although used in a drug discovery context, this activity can be incorporated into a range of undergraduate/graduate chemistry and biochemistry courses either as a stand-alone activity or integrated into existing curricula. The activity uses AutoDock Vina, AutoDockTools, Strawberry Perl, and PyMOL, all of which are free, open-source software. The activity is used to carry out molecular docking of multiple ligands at once and predict the binding energy of hits identified from a high-throughput drug repurposing screen against a target enzyme overexpressed in human tumors. Students analyze their docking results to determine drugs that should go on to further in vitro testing based on the predicted noncovalent ligand–protein interactions. This activity serves as an introduction to molecular docking and as a review of intermolecular forces, highlighting their importance in biological fields.}, number={10}, journal={JOURNAL OF CHEMICAL EDUCATION}, author={Fikes, Audrey G. and Srougi, Melissa C.}, year={2023}, month={Sep}, pages={4125–4130} }
 @article{srougi_corbett_garcia_sabaoun_santisteban_sivaraman_chen_goller_kelly_2023, title={Innovating Life Sciences Laboratory Training: Molecular Biology Laboratory Education Modules (MBLEMs) as a Model for Advanced Training at Diverse Institutions}, volume={299}, ISSN={["1083-351X"]}, DOI={10.1016/j.jbc.2023.103522}, number={3}, journal={JOURNAL OF BIOLOGICAL CHEMISTRY}, author={Srougi, Melissa and Corbett, Anita and Garcia, Christina and Sabaoun, Michelle and Santisteban, Maria and Sivaraman, Vijay and Chen, Stefanie and Goller, Carlos and Kelly, Robert}, year={2023}, pages={S260–S260} }
 @article{miller_srougi_2021, title={Growth mindset interventions improve academic performance but not mindset in biochemistry}, url={https://doi.org/10.1002/bmb.21556}, DOI={10.1002/bmb.21556}, abstractNote={Growing evidence suggests that students' self‐beliefs about altering their academic abilities can directly influence long‐term achievement. These self‐beliefs or mindsets can either be fixed (unchangeable) or growth oriented. Students with growth mindsets believe their academic abilities can change, which leads to higher grades and academic persistence in contrast to students with fixed mindsets. However, less is known about how these attributes affect student learning, particularly in college level biochemistry courses. In this study, we utilized metacognitive interventions to promote growth mindset among third and fourth year undergraduate students enrolled in a one semester Biochemistry survey course. Using a mixed‐methods study design, we evaluated student mindset, attitudes toward learning, and academic performance over four semesters. Our results suggest that although students' mindsets did not change as a result of growth mindset interventions, their positive perceptions about learning versus performance did increase. Furthermore, students receiving growth mindset interventions significantly outperformed students who did not receive interventions on the final cumulative exam that assessed critical thinking skills. These results suggest that these types of metacognitive interventions can be an effective tool to improve student academic performance in a biochemistry course.}, journal={Biochemistry and Molecular Biology Education}, author={Miller, Heather B. and Srougi, Melissa C.}, year={2021}, month={Sep} }
 @article{goller_srougi_chen_schenkman_kelly_2021, place={SWITZERLAND}, title={Integrating Bioinformatics Tools into Inquiry-based Molecular Biology Laboratory Education Modules}, volume={6}, ISSN={2504-284X}, DOI={10.3389/feduc.2021.711403}, abstractNote={The accelerating expansion of online bioinformatics tools has profoundly impacted molecular biology, with such tools becoming integral to the modern life sciences. As a result, molecular biology laboratory education must train students to leverage bioinformatics in meaningful ways to be prepared for a spectrum of careers. Institutions of higher learning can benefit from a flexible and dynamic instructional paradigm that blends up-to-date bioinformatics training with best practices in molecular biology laboratory pedagogy. At North Carolina State University, the campus-wide interdisciplinary Biotechnology (BIT) Program has developed cutting-edge, flexible, inquiry-based Molecular Biology Laboratory Education Modules (MBLEMs). MBLEMs incorporate relevant online bioinformatics tools using evidenced-based pedagogical practices and in alignment with national learning frameworks. Students in MBLEMs engage in the most recent experimental developments in modern biology (e.g., CRISPR, metagenomics) through the strategic use of bioinformatics, in combination with wet-lab experiments, to address research questions. MBLEMs are flexible educational units that provide a menu of inquiry-based laboratory exercises that can be used as complete courses or as parts of existing courses. As such, MBLEMs are designed to serve as resources for institutions ranging from community colleges to research-intensive universities, involving a diverse range of learners. Herein, we describe this new paradigm for biology laboratory education that embraces bioinformatics as a critical component of inquiry-based learning for undergraduate and graduate students representing the life sciences, the physical sciences, and engineering.}, number={Article Number: 711403}, journal={Frontiers in Education}, publisher={FRONTIERS MEDIA SA}, author={Goller, C.C. and Srougi, M.C. and Chen, S.H. and Schenkman, L.R. and Kelly, R.M.}, year={2021} }
 @article{miller_srougi_2020, title={Using Metacognitive Strategies to Improve Academic Performance in Biochemistry}, volume={7}, url={https://doi.org/10.1101/2020.07.08.193649}, DOI={10.1101/2020.07.08.193649}, abstractNote={Growing evidence suggests that students’ self-beliefs about the ability to alter their academic abilities can directly influence long-term achievement. These self-beliefs or mindsets can either be fixed (unchangeable) or growth oriented. Students with growth mindsets believe their academic abilities can change, which leads to higher grades and academic persistence in contrast to students with fixed mindsets. However, less is known about how these attributes affect student learning, particularly in college level biochemistry courses. In this study, we utilized social-psychological interventions to promote growth mindset among third and fourth year undergraduate students enrolled in a one semester Biochemistry survey course. Using a mixed-methods study design we evaluated student mindset, attitudes towards learning, and academic performance over four semesters. Our results suggest that although students’ mindsets did not change as a result of metacognitive interventions, their positive perceptions about learning vs performance did increase. Furthermore, students receiving growth mindset interventions significantly outperformed students who did not receive interventions on the final cumulative exam that assessed critical thinking skills. These results suggest that metacognitive interventions can be an effective tool to improve student academic performance in a biochemistry course.}, publisher={Cold Spring Harbor Laboratory}, author={Miller, Heather B. and Srougi, Melissa C.}, year={2020}, month={Jul} }
 @article{tolbert_palmquist_dixon_srougi_2019, title={Examining the Dynamics of Cellular Adhesion and Spreading of Epithelial Cells on Fibronectin During Oxidative Stress}, volume={10}, ISSN={["1940-087X"]}, url={https://doi.org/10.3791/59989}, DOI={10.3791/59989}, abstractNote={The adhesion and spreading of cells onto the extracellular matrix (ECM) are essential cellular processes during organismal development and for the homeostasis of adult tissues. Interestingly, oxidative stress can alter these processes, thus contributing to the pathophysiology of diseases such as metastatic cancer. Therefore, understanding the mechanism(s) of how cells attach and spread on the ECM during perturbations in redox status can provide insight into normal and disease states. Described below is a step-wise protocol that utilizes an immunofluorescence-based assay to specifically quantify cell adhesion and spreading of immortalized fibroblast cells on fibronectin (FN) in vitro. Briefly, anchorage-dependent cells are held in suspension and exposed to the ATM kinase inhibitor Ku55933 to induce oxidative stress. Cells are then plated on FN-coated surface and allowed to attach for predetermined periods of time. Cells that remain attached are fixed and labeled with fluorescence-based antibody markers of adhesion (e.g., paxillin) and spreading (e.g., F-actin). Data acquisition and analysis are performed using commonly available laboratory equipment, including an epifluorescence microscope and freely available Fiji software. This procedure is highly versatile and can be modified for a variety of cell lines, ECM proteins, or inhibitors in order to examine a broad range of biological questions.}, number={152}, journal={JOVE-JOURNAL OF VISUALIZED EXPERIMENTS}, author={Tolbert, Caitlin E. and Palmquist, Lindsey and Dixon, Hannah Lee and Srougi, Melissa C.}, year={2019}, month={Oct} }
 @article{tolbert_beck_kilmer_srougi_2019, title={Loss of ATM positively regulates Rac1 activity and cellular migration through oxidative stress}, volume={508}, ISSN={["1090-2104"]}, url={https://doi.org/10.1016/j.bbrc.2018.12.033}, DOI={10.1016/j.bbrc.2018.12.033}, abstractNote={Ataxia-telangiectasia mutated (ATM) is a serine-threonine kinase that is integral in the response to DNA double-stranded breaks (DSBs). Cells and tissues lacking ATM are prone to tumor development and enhanced tumor cell migration and invasion. Interestingly, ATM-deficient cells exhibit high levels of oxidative stress; however, the direct mechanism whereby ATM-associated oxidative stress may contribute to the cancer phenotype remains largely unexplored. Rac1, a member of the Rho family of GTPases, also plays an important regulatory role in cellular growth, motility, and cancer formation. Rac1 can be activated directly by reactive oxygen species (ROS), by a mechanism distinct from canonical guanine nucleotide exchange factor-driven activation. Here we show that loss of ATM kinase activity elevates intracellular ROS, leading to Rac1 activation. Rac1 activity drives cytoskeletal rearrangements resulting in increased cellular spreading and motility. Rac1 siRNA or treatment with the ROS scavenger N-Acetyl-L-cysteine restores wild-type migration. These studies demonstrate a novel mechanism whereby ATM activity and ROS generation regulates Rac1 to modulate pro-migratory cellular behavior.}, number={4}, journal={BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS}, publisher={Elsevier BV}, author={Tolbert, Caitlin E. and Beck, Matthew V. and Kilmer, Claire E. and Srougi, Melissa C.}, year={2019}, month={Jan}, pages={1155–1161} }
 @book{carson_miller_srougi_witherow_2019, title={Molecular Biology Techniques 4th Edition}, url={https://www.elsevier.com/books/molecular-biology-techniques/carson/978-0-12-815774-9}, journal={Elsevier}, publisher={Academic Press}, author={Carson, S.D. and Miller, H.B. and Srougi, M.C. and Witherow, S.D.}, year={2019}, month={Mar} }
 @article{srougi_miller_2018, title={Peer learning as a tool to strengthen math skills in introductory chemistry laboratories}, volume={19}, url={https://doi.org/10.1039/C7RP00152E}, DOI={10.1039/C7RP00152E}, abstractNote={Math skills vary greatly among students enrolled in introductory chemistry courses. Students with weak math skills (algebra and below) tend to perform poorly in introductory chemistry courses, which is correlated with increased attrition rates. Previous research has shown that retention of main ideas in a peer learning environment is greater when partners have dissimilar abilities. Therefore, in an effort to improve student learning outcomes, we implemented peer learning interventions in our introductory chemistry laboratories to determine if math skills were enhanced when partners differed in math ability. Student performance and attitudes were analyzed in laboratory sections consisting of instructor-assigned partners who differed in math ability, compared to sections where students self-selected a partner. Students who were assigned math partners of different ability showed an 8% improvement in chemistry math concepts compared to no improvement among those who self-selected a partner, as assessed using pre- and post-math tests. Mathematical learning gains were particularly large (16%) for those students in the 50th percentile of math performance. Students also reported a significantly more positive attitude change about working with others compared to students who self-selected a partner. In addition, assigned students demonstrated a more positive shift in self-concepts such as chemistry knowledge and laboratory skills. This study illustrates that peer learning can serve as a useful and easy-to-implement tool to strengthen math skills and improve student attitudes in introductory chemistry laboratories.}, number={1}, journal={Chemistry Education Research and Practice}, publisher={Royal Society of Chemistry (RSC)}, author={Srougi, Melissa C. and Miller, Heather B.}, year={2018}, pages={319–330} }
 @article{student-designed high-throughput assays to assess effects of growth insults in budding yeast._2018, url={http://europepmc.org/articles/PMC6022778}, DOI={10.1128/jmbe.v19i2.1542}, abstractNote={Modern high-throughput screening is a versatile method used widely in academic and industrial labs for genetic and pharmacological testing, but is underutilized in undergraduate laboratories. We designed an open inquiry-based laboratory activity exploiting a small-scale high-throughput screening assay of the budding yeast S. cerevisiae to promote active learning and introduce students to modern data collection and analysis techniques. In this activity, students at both the high school and university levels generate growth curves of S. cerevisiae using a microplate reader after treatment with their insult of choice. This lab presents an ideal opportunity for both high school and university students to actively learn about the process of science as well as high-throughput data collection and analysis in a cost-effective manner.}, journal={Journal of microbiology & biology education}, year={2018}, month={Jun} }
 @article{srougi_carson_thomas-swanik_marchant_chan_2014, title={Making Heads or Tails: Planarian Stem Cells in the Classroom †}, volume={15}, ISSN={1935-7877 1935-7885}, url={http://dx.doi.org/10.1128/jmbe.v15i1.692}, DOI={10.1128/jmbe.v15i1.692}, abstractNote={Stem cells hold great promise in the treatment of diseases ranging from cancer to dementia. However, as rapidly as the field of stem cell biology has emerged, heated political debate has followed, scrutinizing the ethical implications of stem cell use. It is therefore imperative to promote scientific literacy by educating students about stem cell biology. Yet, there is a definite lack of material to engage students in this subject at the basic science level. Therefore, we have developed and implemented a hands-on introductory laboratory module that introduces students to stem cell biology and can be easily incorporated into existing curricula. Students learn about stem cell biology using an in vivo planarian model system in which they down-regulate two genes important in stem cell differentiation using RNA interference and then observe the regenerative phenotype. The module was piloted at the high school, community college, and university levels. Here, we report that introductory biology students enrolled at a community college were able to demonstrate gains in learning after completion of a one-hour lecture and four 45-minute laboratory sessions over the course of three weeks. These gains in learning outcomes were objectively evaluated both before and after its execution using a student quiz and experimental results. Furthermore, students’ self-assessments revealed increases in perceived knowledge as well as a general interest in stem cells. Therefore, these data suggest that this module is a simple, useful way to engage and to teach students about stem cell biology.}, number={1}, journal={Journal of Microbiology & Biology Education}, publisher={American Society for Microbiology}, author={Srougi, Melissa C. and Carson, Susan and Thomas-Swanik, Jackie and Marchant, Jonathan S. and Chan, John D.}, year={2014}, month={May}, pages={18–25} }
 @article{tumor-selective, futile redox cycle-induced bystander effects elicited by nqo1 bioactivatable radiosensitizing drugs in triple-negative breast cancers._2014, url={http://europepmc.org/articles/PMC4060774}, DOI={10.1089/ars.2013.5462}, abstractNote={AIMS
β-Lapachone (β-lap), a novel radiosensitizer with potent antitumor efficacy alone, selectively kills solid cancers that over-express


NAD(P)H
quinone oxidoreductase 1 (NQO1). Since breast or other solid cancers have heterogeneous NQO1 expression, therapies that reduce the resistance (e.g., NQO1(low)) of tumor cells will have significant clinical advantages. We tested whether NQO1-proficient (NQO1(+)) cells generated sufficient hydrogen peroxide (H2O2) after β-lap treatment to elicit bystander effects, DNA damage, and cell death in neighboring NQO1(low) cells.


RESULTS
β-Lap showed NQO1-dependent efficacy against two triple-negative breast cancer (TNBC) xenografts. NQO1 expression variations in human breast cancer patient samples were noted, where ~60% cancers over-expressed NQO1, with little or no expression in associated normal tissue. Differential DNA damage and lethality were noted in NQO1(+) versus NQO1-deficient (NQO1(-)) TNBC cells and xenografts after β-lap treatment. β-Lap-treated NQO1(+) cells died by programmed necrosis, whereas co-cultured NQO1(-) TNBC cells exhibited DNA damage and caspase-dependent apoptosis. NQO1 inhibition (dicoumarol) or H2O2 scavenging (catalase [CAT]) blocked all responses. Only NQO1(-) cells neighboring NQO1(+) TNBC cells responded to β-lap in vitro, and bystander effects correlated well with H2O2 diffusion. Bystander effects in NQO1(-) cells in vivo within mixed 50:50 co-cultured xenografts were dramatic and depended on NQO1(+) cells. However, normal human cells in vitro or in vivo did not show bystander effects, due to elevated endogenous CAT levels. Innovation and Conclusions: NQO1-dependent bystander effects elicited by NQO1 bioactivatable drugs (β-lap or deoxynyboquinone [DNQ]) likely contribute to their efficacies, killing NQO1(+) solid cancer cells and eliminating surrounding heterogeneous NQO1(low) cancer cells. Normal cells/tissue are protected by low NQO1:CAT ratios.}, journal={Antioxidants & redox signaling}, year={2014}, month={Apr} }
 @article{srougi_miller_witherow_carson_2013, title={Assessment of a novel group-centered testing schema in an upper-level undergraduate molecular biotechnology course}, volume={41}, ISSN={["1539-3429"]}, url={https://doi.org/10.1002/bmb.20701}, DOI={10.1002/bmb.20701}, abstractNote={Providing students with assignments that focus on critical thinking is an important part of their scientific and intellectual development. However, as class sizes increase, so does the grading burden, prohibiting many faculty from incorporating critical thinking assignments in the classroom. In an effort to continue to provide our students with meaningful critical thinking exercises, we implemented a novel group‐centered, problem‐based testing scheme. We wanted to assess how performing critical thinking problem sets as group work compares to performing the sets as individual work, in terms of student attitudes and learning outcomes. During two semesters of our recombinant DNA course, students had the same lecture material and similar assessments. In the Fall semester, student learning was assessed by two collaborative take‐home exams, followed immediately by individual, closed‐book in‐class exams on the same content, as well as a final cumulative exam. Student teams on the take‐home exams were instructor‐assigned, and each team turned in one collaborative exam. In the Spring semester, the control group of students were required to turn in their own individual take‐home exams, followed by the in‐class exams and final cumulative exam. For the majority of students, learning outcomes were met, regardless of whether they worked in teams. In addition, collaborative learning was favorably received by students and grading was reduced for instructors. These data suggest that group‐centered, problem‐based learning is a useful model for achievement of student learning outcomes in courses where it would be infeasible to provide feedback on individual critical thinking assignments due to grading volume. © 2013 by The International Union of Biochemistry and Molecular Biology, 41(4):232–241, 2013}, number={4}, journal={BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION}, author={Srougi, Melissa C. and Miller, Heather B. and Witherow, D. Scott and Carson, Susan}, year={2013}, month={Jul}, pages={232–241} }
 @article{catalase abrogates β-lapachone-induced parp1 hyperactivation-directed programmed necrosis in nqo1-positive breast cancers._2013, url={http://europepmc.org/articles/PMC3807805}, DOI={10.1158/1535-7163.MCT-12-0962}, abstractNote={Improving patient outcome by personalized therapy involves a thorough understanding of an agent's mechanism of action. β-Lapachone (clinical forms, Arq501/Arq761) has been developed to exploit dramatic cancer-specific elevations in the phase II detoxifying enzyme NAD(P)H:quinone oxidoreductase (NQO1). NQO1 is dramatically elevated in solid cancers, including primary and metastatic [e.g., triple-negative (ER−, PR−, Her2/Neu−)] breast cancers. To define cellular factors that influence the efficacy of β-lapachone using knowledge of its mechanism of action, we confirmed that NQO1 was required for lethality and mediated a futile redox cycle where ∼120 moles of superoxide were formed per mole of β-lapachone in 2 minutes. β-Lapachone induced reactive oxygen species (ROS), stimulated DNA single-strand break-dependent poly(ADP-ribose) polymerase-1 (PARP1) hyperactivation, caused dramatic loss of essential nucleotides (NAD+/ATP), and elicited programmed necrosis in breast cancer cells. Although PARP1 hyperactivation and NQO1 expression were major determinants of β-lapachone–induced lethality, alterations in catalase expression, including treatment with exogenous enzyme, caused marked cytoprotection. Thus, catalase is an important resistance factor and highlights H2O2 as an obligate ROS for cell death from this agent. Exogenous superoxide dismutase enhanced catalase-induced cytoprotection. β-Lapachone–induced cell death included apoptosis-inducing factor (AIF) translocation from mitochondria to nuclei, TUNEL+ staining, atypical PARP1 cleavage, and glyceraldehyde 3-phosphate dehydrogenase S-nitrosylation, which were abrogated by catalase. We predict that the ratio of NQO1:catalase activities in breast cancer versus associated normal tissue are likely to be the major determinants affecting the therapeutic window of β-lapachone and other NQO1 bioactivatable drugs. Mol Cancer Ther; 12(10); 2110–20. ©2013 AACR.}, journal={Molecular cancer therapeutics}, year={2013}, month={Jul} }
 @article{srougi_carson_2013, title={Inquiry into chemotherapy-induced p53 activation in cancer cells as a model for teaching signal transduction}, volume={41}, ISSN={1470-8175}, url={http://dx.doi.org/10.1002/bmb.20741}, DOI={10.1002/bmb.20741}, abstractNote={Abstract}, number={6}, journal={Biochemistry and Molecular Biology Education}, publisher={Wiley}, author={Srougi, Melissa C. and Carson, Susan}, year={2013}, month={Nov}, pages={419–432} }
 @article{the nuclear guanine nucleotide exchange factors ect2 and net1 regulate rhob-mediated cell death after dna damage._2011, url={http://europepmc.org/articles/PMC3044157}, DOI={10.1371/journal.pone.0017108}, abstractNote={Commonly used antitumor treatments, including radiation and chemotherapy, function by damaging the DNA of rapidly proliferating cells. However, resistance to these agents is a predominant clinical problem. A member of the Rho family of small GTPases, RhoB has been shown to be integral in mediating cell death after ionizing radiation (IR) or other DNA damaging agents in Ras-transformed cell lines. In addition, RhoB protein expression increases after genotoxic stress, and loss of RhoB expression causes radio- and chemotherapeutic resistance. However, the signaling pathways that govern RhoB-induced cell death after DNA damage remain enigmatic. Here, we show that RhoB activity increases in human breast and cervical cancer cell lines after treatment with DNA damaging agents. Furthermore, RhoB activity is necessary for DNA damage-induced cell death, as the stable loss of RhoB protein expression using shRNA partially protects cells and prevents the phosphorylation of c-Jun N-terminal kinases (JNKs) and the induction of the pro-apoptotic protein Bim after IR. The increase in RhoB activity after genotoxic stress is associated with increased activity of the nuclear guanine nucleotide exchange factors (GEFs), Ect2 and Net1, but not the cytoplasmic GEFs p115 RhoGEF or Vav2. Importantly, loss of Ect2 and Net1 via siRNA-mediated protein knock-down inhibited IR-induced increases in RhoB activity, reduced apoptotic signaling events, and protected cells from IR-induced cell death. Collectively, these data suggest a mechanism involving the nuclear GEFs Ect2 and Net1 for activating RhoB after genotoxic stress, thereby facilitating cell death after treatment with DNA damaging agents.}, journal={PloS one}, year={2011}, month={Feb} }
 @article{the small gtpase rhoa localizes to the nucleus and is activated by net1 and dna damage signals._2011, url={http://europepmc.org/articles/PMC3044755}, DOI={10.1371/journal.pone.0017380}, abstractNote={Background Rho GTPases control many cellular processes, including cell survival, gene expression and migration. Rho proteins reside mainly in the cytosol and are targeted to the plasma membrane (PM) upon specific activation by guanine nucleotide exchange factors (GEFs). Accordingly, most GEFs are also cytosolic or associated with the PM. However, Net1, a RhoA-specific GEF predominantly localizes to the cell nucleus at steady-state. Nuclear localization for Net1 has been seen as a mechanism for sequestering the GEF away from RhoA, effectively rendering the protein inactive. However, considering the prominence of nuclear Net1 and the fact that a biological stimulus that promotes Net1 translocation out the nucleus to the cytosol has yet to be discovered, we hypothesized that Net1 might have a previously unidentified function in the nucleus of cells. Principal Findings Using an affinity precipitation method to pulldown the active form of Rho GEFs from different cellular fractions, we show here that nuclear Net1 does in fact exist in an active form, contrary to previous expectations. We further demonstrate that a fraction of RhoA resides in the nucleus, and can also be found in a GTP-bound active form and that Net1 plays a role in the activation of nuclear RhoA. In addition, we show that ionizing radiation (IR) specifically promotes the activation of the nuclear pool of RhoA in a Net1-dependent manner, while the cytoplasmic activity remains unchanged. Surprisingly, irradiating isolated nuclei alone also increases nuclear RhoA activity via Net1, suggesting that all the signals required for IR-induced nuclear RhoA signaling are contained within the nucleus. Conclusions/Significance These results demonstrate the existence of a functional Net1/RhoA signaling pathway within the nucleus of the cell and implicate them in the DNA damage response.}, journal={PloS one}, year={2011}, month={Feb} }
 @article{undressing a cellular corset: septins exposed._2009, url={https://doi.org/10.1038/ncb0109-9}, DOI={10.1038/ncb0109-9}, journal={Nature cell biology}, year={2009}, month={Jan} }
 @article{an nqo1- and parp-1-mediated cell death pathway induced in non-small-cell lung cancer cells by beta-lapachone._2007, url={http://europepmc.org/articles/PMC1913860}, DOI={10.1073/pnas.0702176104}, abstractNote={Lung cancer is the number one cause of cancer-related deaths in the world. Patients treated with current chemotherapies for non-small-cell lung cancers (NSCLCs) have a survival rate of ≈15% after 5 years. Novel approaches are needed to treat this disease. We show elevated NAD(P)H:quinone oxidoreductase-1 (NQO1) levels in tumors from NSCLC patients. β-Lapachone, an effective chemotherapeutic and radiosensitizing agent, selectively killed NSCLC cells that expressed high levels of NQO1. Isogenic H596 NSCLC cells that lacked or expressed NQO1 along with A549 NSCLC cells treated with or without dicoumarol, were used to elucidate the mechanism of action and optimal therapeutic window of β-lapachone. NSCLC cells were killed in an NQO1-dependent manner by β-lapachone (LD50, ≈4 μM) with a minimum 2-h exposure. Kinetically, β-lapachone-induced cell death was characterized by the following: (i) dramatic reactive oxygen species (ROS) formation, eliciting extensive DNA damage; (ii) hyperactivation of poly(ADP-ribose)polymerase-1 (PARP-1); (iii) depletion of NAD+/ATP levels; and (iv) proteolytic cleavage of p53/PARP-1, indicating μ-calpain activation and apoptosis. β-Lapachone-induced PARP-1 hyperactivation, nucleotide depletion, and apoptosis were blocked by 3-aminobenzamide, a PARP-1 inhibitor, and 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid acetoxymethyl ester (BAPTA-AM), a Ca2+ chelator. NQO1− cells (H596, IMR-90) or dicoumarol-exposed NQO1+ A549 cells were resistant (LD50, >40 μM) to ROS formation and all cytotoxic effects of β-lapachone. Our data indicate that the most efficacious strategy using β-lapachone in chemotherapy was to deliver the drug in short pulses, greatly reducing cytotoxicity to NQO1− “normal” cells. β-Lapachone killed cells in a tumorselective manner and is indicated for use against NQO1+ NSCLC cancers.}, journal={Proceedings of the National Academy of Sciences of the United States of America}, year={2007}, month={Jul} }
 @article{nonhomologous end joining is essential for cellular resistance to the novel antitumor agent, beta-lapachone._2007, url={https://doi.org/10.1158/0008-5472.CAN-07-0935}, DOI={10.1158/0008-5472.can-07-0935}, abstractNote={Commonly used antitumor agents, such as DNA topoisomerase I/II poisons, kill cancer cells by creating nonrepairable DNA double-strand breaks (DSBs). To repair DSBs, error-free homologous recombination (HR), and/or error-prone nonhomologous end joining (NHEJ) are activated. These processes involve the phosphatidylinositol 3'-kinase-related kinase family of serine/threonine enzymes: ataxia telangiectasia mutated (ATM), ATM- and Rad3-related for HR, and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) for NHEJ. Alterations in these repair processes can cause drug/radiation resistance and increased genomic instability. beta-Lapachone (beta-lap; also known as ARQ 501), currently in phase II clinical trials for the treatment of pancreatic cancer, causes a novel caspase- and p53-independent cell death in cancer cells overexpressing NAD(P)H:quinone oxidoreductase-1 (NQO1). NQO1 catalyzes a futile oxidoreduction of beta-lap leading to reactive oxygen species generation, DNA breaks, gamma-H2AX foci formation, and hyperactivation of poly(ADP-ribose) polymerase-1, which is required for cell death. Here, we report that beta-lap exposure results in NQO1-dependent activation of the MRE11-Rad50-Nbs-1 complex. In addition, ATM serine 1981, DNA-PKcs threonine 2609, and Chk1 serine 345 phosphorylation were noted; indicative of simultaneous HR and NHEJ activation. However, inhibition of NHEJ, but not HR, by genetic or chemical means potentiated beta-lap lethality. These studies give insight into the mechanism by which beta-lap radiosensitizes cancer cells and suggest that NHEJ is a potent target for enhancing the therapeutic efficacy of beta-lap alone or in combination with other agents in cancer cells that express elevated NQO1 levels.}, journal={Cancer research}, year={2007}, month={Jul} }
 @article{calcium-dependent modulation of poly(adp-ribose) polymerase-1 alters cellular metabolism and dna repair._2006, url={https://doi.org/10.1074/jbc.M603678200}, DOI={10.1074/jbc.m603678200}, abstractNote={After genotoxic stress poly(ADP-ribose) polymerase-1 (PARP-1) can be hyperactivated, causing (ADP-ribosyl)ation of nuclear proteins (including itself), resulting in NAD+ and ATP depletion and cell death. Mechanisms of PARP-1-mediated cell death and downstream proteolysis remain enigmatic. β-lapachone (β-lap) is the first chemotherapeutic agent to elicit a Ca2+-mediated cell death by PARP-1 hyperactivation at clinically relevent doses in cancer cells expressing elevated NAD(P)H:quinone oxidoreductase 1 (NQO1) levels. β-lap induces the generation of NQO1-dependent reactive oxygen species (ROS), DNA breaks, and triggers Ca2+-dependent γ-H2AX formation and PARP-1 hyperactivation. Subsequent NAD+ and ATP losses suppress DNA repair and cause cell death. Reduction of PARP-1 activity or Ca2+ chelation protects cells. Interestingly, Ca2+ chelation abrogates hydrogen peroxide (H2O2), but not N-Methyl-N′-nitro-N-nitrosoguanidine (MNNG)-induced PARP-1 hyperactivation and cell death. Thus, Ca2+ appears to be an important co-factor in PARP-1 hyperactivation after ROS-induced DNA damage, which alters cellular metabolism and DNA repair.}, journal={The Journal of biological chemistry}, year={2006}, month={Aug} }
 @article{mornings with art, lessons learned: feedback regulation, restriction threshold biology, and redundancy govern molecular stress responses._2006, url={https://doi.org/10.1002/jcp.20783}, DOI={10.1002/jcp.20783}, abstractNote={Work from the laboratory of Dr. Arthur B. Pardee has highlighted basic principles that govern cellular and molecular biological processes in living cells. Among the most important governing principles in cellular and molecular responses are: (i) threshold “restriction” responses, wherein a level of response is reached and a “point of no return” is achieved; (ii) feedback regulation; and (iii) redundancy. Lessons learned from the molecular biology of cellular stress responses in mammalian cancer versus normal cells after ionizing radiation (IR) or chemotherapeutic agent exposures reveal similar instances of these guiding principles in mammalian cells. Among these are the: (i) induction of cell death responses by β‐lapachone (β‐lap), a naphthoquinone anti‐tumor agent that kills cancer cells via an NQO1 (i.e., X‐ray‐inducible protein‐3, xip3)‐dependent mechanism; (ii) induction of secretory clusterin (sCLU) in response to TGF‐β1 exposure, and the ability of induced sCLU protein to down‐regulate TGF‐β1 signaling; and (iii) induction of DNA mismatch repair‐dependent G2 cell cycle checkpoint responses after exposure to alkylating agents. We have learned these lessons and now adopted strategies to exploit them for improved therapy. These examples will be discussed and compared to the pioneering findings of researchers in the Pardee laboratory over the years. J. Cell. Physiol. 209: 604–610, 2006. © 2006 Wiley‐Liss, Inc.}, journal={Journal of cellular physiology}, year={2006}, month={Dec} }
 @article{new tricks for old drugs: the anticarcinogenic potential of dna repair inhibitors._2006, url={https://doi.org/10.1007/s10735-006-9043-8}, DOI={10.1007/s10735-006-9043-8}, abstractNote={Defective or abortive repair of DNA lesions has been associated with carcinogenesis. Therefore it is imperative for a cell to accurately repair its DNA after damage if it is to return to a normal cellular phenotype. In certain circumstances, if DNA damage cannot be repaired completely and with high fidelity, it is more advantageous for an organism to have some of its more severely damaged cells die rather than survive as neoplastic transformants. A number of DNA repair inhibitors have the potential to act as anticarcinogenic compounds. These drugs are capable of modulating DNA repair, thus promoting cell death rather than repair of potentially carcinogenic DNA damage mediated by error-prone DNA repair processes. In theory, exposure to a DNA repair inhibitor during, or immediately after, carcinogenic exposure should decrease or prevent tumorigenesis. However, the ability of DNA repair inhibitors to prevent cancer development is difficult to interpret depending upon the system used and the type of genotoxic stress. Inhibitors may act on multiple aspects of DNA repair as well as the cellular signaling pathways activated in response to the initial damage. In this review, we summarize basic DNA repair mechanisms and explore the effects of a number of DNA repair inhibitors that not only potentiate DNA-damaging agents but also decrease carcinogenicity. In particular, we focus on a novel anti-tumor agent, beta-lapachone, and its potential to block transformation by modulating poly(ADP-ribose) polymerase-1.}, journal={Journal of molecular histology}, year={2006}, month={Jul} }
 @article{development of beta-lapachone prodrugs for therapy against human cancer cells with elevated nad(p)h:quinone oxidoreductase 1 levels._2005, url={https://doi.org/10.1158/1078-0432.CCR-04-2185}, DOI={10.1158/1078-0432.ccr-04-2185}, abstractNote={β-Lapachone, an o-naphthoquinone, induces a novel caspase- and p53-independent apoptotic pathway dependent on NAD(P)H:quinone oxidoreductase 1 (NQO1). NQO1 reduces β-lapachone to an unstable hydroquinone that rapidly undergoes a two-step oxidation back to the parent compound, perpetuating a futile redox cycle. A deficiency or inhibition of NQO1 rendered cells resistant to β-lapachone. Thus, β-lapachone has great potential for the treatment of specific cancers with elevated NQO1 levels (e.g., breast, non–small cell lung, pancreatic, colon, and prostate cancers). We report the development of mono(arylimino) derivatives of β-lapachone as potential prodrugs. These derivatives are relatively nontoxic and not substrates for NQO1 when initially diluted in water. In solution, however, they undergo hydrolytic conversion to β-lapachone at rates dependent on the electron-withdrawing strength of their substituent groups and pH of the diluent. NQO1 enzyme assays, UV-visible spectrophotometry, high-performance liquid chromatography-electrospray ionization-mass spectrometry, and nuclear magnetic resonance analyses confirmed and monitored conversion of each derivative to β-lapachone. Once converted, β-lapachone derivatives caused NQO1-dependent, μ-calpain-mediated cell death in human cancer cells identical to that caused by β-lapachone. Interestingly, coadministration of N-acetyl-l-cysteine, prevented derivative-induced cytotoxicity but did not affect β-lapachone lethality. Nuclear magnetic resonance analyses indicated that prevention of β-lapachone derivative cytotoxicity was the result of direct modification of these derivatives by N-acetyl-l-cysteine, preventing their conversion to β-lapachone. The use of β-lapachone mono(arylimino) prodrug derivatives, or more specifically a derivative converted in a tumor-specific manner (i.e., in the acidic local environment of the tumor tissue), should reduce normal tissue toxicity while eliciting tumor-selective cell killing by NQO1 bioactivation.}, journal={Clinical cancer research : an official journal of the American Association for Cancer Research}, year={2005}, month={Apr} }