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Siqueira PB, de Sousa Rodrigues MM, de Amorim ÍSS, da Silva TG, da Silva Oliveira M, Rodrigues JA, de Souza da Fonseca A, Mencalha AL. The APE1/REF-1 and the hallmarks of cancer. Mol Biol Rep 2024; 51:47. [PMID: 38165468 DOI: 10.1007/s11033-023-08946-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 10/10/2023] [Indexed: 01/03/2024]
Abstract
APE1/REF-1 (apurinic/apyrimidinic endonuclease 1 / redox factor-1) is a protein with two domains, with endonuclease function and redox activity. Its main activity described is acting in DNA repair by base excision repair (BER) pathway, which restores DNA damage caused by oxidation, alkylation, and single-strand breaks. In contrast, the APE1 redox domain is responsible for regulating transcription factors, such as AP-1 (activating protein-1), NF-κB (Nuclear Factor kappa B), HIF-1α (Hypoxia-inducible factor 1-alpha), and STAT3 (Signal Transducers and Activators of Transcription 3). These factors are involved in physiological cellular processes, such as cell growth, inflammation, and angiogenesis, as well as in cancer. In human malignant tumors, APE1 overexpression is associated with lung, colon, ovaries, prostate, and breast cancer progression, more aggressive tumor phenotypes, and worse prognosis. In this review, we explore APE1 and its domain's role in cancer development processes, highlighting the role of APE1 in the hallmarks of cancer. We reviewed original articles and reviews from Pubmed related to APE1 and cancer and found that both domains of APE1/REF-1, but mainly its redox activity, are essential to cancer cells. This protein is often overexpressed in cancer, and its expression and activity are correlated to processes such as proliferation, invasion, inflammation, angiogenesis, and resistance to cell death. Therefore, APE1 participates in essential processes of cancer development. Then, the activity of APE1/REF-1 in these hallmarks suggests that targeting this protein could be a good therapeutic approach.
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Affiliation(s)
- Priscyanne Barreto Siqueira
- Departamento de Biofísica e Biometria, Laboratório de Biologia do Câncer, Universidade do Estado do Rio de Janeiro, Instituto de Biologia Roberto Alcântara Gomes, Rio de Janeiro, Brasil.
| | - Mariana Moreno de Sousa Rodrigues
- Departamento de Biofísica e Biometria, Laboratório de Biologia do Câncer, Universidade do Estado do Rio de Janeiro, Instituto de Biologia Roberto Alcântara Gomes, Rio de Janeiro, Brasil.
| | - Ísis Salviano Soares de Amorim
- Departamento de Biofísica e Biometria, Laboratório de Biologia do Câncer, Universidade do Estado do Rio de Janeiro, Instituto de Biologia Roberto Alcântara Gomes, Rio de Janeiro, Brasil
- Laboratório de Alimentos Funcionais, Universidade Federal do Rio de Janeiro, Instituto de Nutrição Josué de Castro, Rio de Janeiro, Brasil
| | - Thayssa Gomes da Silva
- Departamento de Biofísica e Biometria, Laboratório de Biofotônica, Universidade do Estado do Rio de Janeiro, Instituto de Biologia Roberto Alcântara Gomes, Rio de Janeiro, Brasil
| | - Matheus da Silva Oliveira
- Departamento de Biofísica e Biometria, Laboratório de Biologia do Câncer, Universidade do Estado do Rio de Janeiro, Instituto de Biologia Roberto Alcântara Gomes, Rio de Janeiro, Brasil
| | - Juliana Alves Rodrigues
- Departamento de Biofísica e Biometria, Laboratório de Biologia do Câncer, Universidade do Estado do Rio de Janeiro, Instituto de Biologia Roberto Alcântara Gomes, Rio de Janeiro, Brasil
| | - Adenilson de Souza da Fonseca
- Departamento de Biofísica e Biometria, Laboratório de Biofotônica, Universidade do Estado do Rio de Janeiro, Instituto de Biologia Roberto Alcântara Gomes, Rio de Janeiro, Brasil
| | - Andre Luiz Mencalha
- Departamento de Biofísica e Biometria, Laboratório de Biologia do Câncer, Universidade do Estado do Rio de Janeiro, Instituto de Biologia Roberto Alcântara Gomes, Rio de Janeiro, Brasil
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Das D, Duncton MAJ, Georgiadis TM, Pellicena P, Clark J, Sobol RW, Georgiadis MM, King-Underwood J, Jobes DV, Chang C, Gao Y, Deacon AM, Wilson DM. A New Drug Discovery Platform: Application to DNA Polymerase Eta and Apurinic/Apyrimidinic Endonuclease 1. Int J Mol Sci 2023; 24:16637. [PMID: 38068959 PMCID: PMC10706420 DOI: 10.3390/ijms242316637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/26/2023] [Accepted: 10/27/2023] [Indexed: 12/18/2023] Open
Abstract
The ability to quickly discover reliable hits from screening and rapidly convert them into lead compounds, which can be verified in functional assays, is central to drug discovery. The expedited validation of novel targets and the identification of modulators to advance to preclinical studies can significantly increase drug development success. Our SaXPyTM ("SAR by X-ray Poses Quickly") platform, which is applicable to any X-ray crystallography-enabled drug target, couples the established methods of protein X-ray crystallography and fragment-based drug discovery (FBDD) with advanced computational and medicinal chemistry to deliver small molecule modulators or targeted protein degradation ligands in a short timeframe. Our approach, especially for elusive or "undruggable" targets, allows for (i) hit generation; (ii) the mapping of protein-ligand interactions; (iii) the assessment of target ligandability; (iv) the discovery of novel and potential allosteric binding sites; and (v) hit-to-lead execution. These advances inform chemical tractability and downstream biology and generate novel intellectual property. We describe here the application of SaXPy in the discovery and development of DNA damage response inhibitors against DNA polymerase eta (Pol η or POLH) and apurinic/apyrimidinic endonuclease 1 (APE1 or APEX1). Notably, our SaXPy platform allowed us to solve the first crystal structures of these proteins bound to small molecules and to discover novel binding sites for each target.
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Affiliation(s)
- Debanu Das
- XPose Therapeutics, Inc., San Carlos, CA 94070, USA
- Accelero Biostructures, Inc., San Carlos, CA 94070, USA
| | | | | | | | - Jennifer Clark
- Mitchell Cancer Institute and Department of Pharmacology, University of South Alabama, Mobile, AL 36604, USA
| | - Robert W. Sobol
- Mitchell Cancer Institute and Department of Pharmacology, University of South Alabama, Mobile, AL 36604, USA
- Department of Pathology & Laboratory Medicine, Warrant Alpert Medical School & Legorreta Cancer Center, Brown University, Providence, RI 02912, USA
| | - Millie M. Georgiadis
- XPose Therapeutics, Inc., San Carlos, CA 94070, USA
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | | - David V. Jobes
- XPose Therapeutics, Inc., San Carlos, CA 94070, USA
- Mid-Atlantic BioTherapeutics, Inc., Doylestown, PA 18902, USA
| | - Caleb Chang
- Department of BioSciences, Rice University, Houston, TX 77251, USA
| | - Yang Gao
- Department of BioSciences, Rice University, Houston, TX 77251, USA
| | - Ashley M. Deacon
- XPose Therapeutics, Inc., San Carlos, CA 94070, USA
- Accelero Biostructures, Inc., San Carlos, CA 94070, USA
| | - David M. Wilson
- XPose Therapeutics, Inc., San Carlos, CA 94070, USA
- Biomedical Research Institute, Hasselt University, 3500 Diepenbeek, Belgium
- Belgium & Boost Scientific, 3550 Heusden-Zolder, Belgium
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3
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Rai R, Dawodu OI, Johnson SM, Vilseck JZ, Kelley MR, Ziarek JJ, Georgiadis MM. Chemically induced partial unfolding of the multifunctional Apurinic/apyrimidinic endonuclease 1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.29.547112. [PMID: 37425839 PMCID: PMC10327033 DOI: 10.1101/2023.06.29.547112] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Targeting of the multifunctional enzyme apurinic/apyrimidinic endonuclease I/redox factor 1 (APE1) has produced small molecule inhibitors of both its endonuclease and redox activities. While one of the small molecules, the redox inhibitor APX3330, completed a Phase I clinical trial for solid tumors and a Phase II clinical trial for Diabetic Retinopathy/Diabetic Macular Edema, the mechanism of action for this drug has yet to be fully understood. Here, we demonstrate through HSQC NMR studies that APX3330 induces chemical shift perturbations (CSPs) of both surface and internal residues in a concentration-dependent manner, with a cluster of surface residues defining a small pocket on the opposite face from the endonuclease active site of APE1. Furthermore, APX3330 induces partial unfolding of APE1 as evidenced by a time-dependent loss of chemical shifts for approximately 35% of the residues within APE1 in the HSQC NMR spectrum. Notably, regions that are partially unfolded include adjacent strands within one of two beta sheets that comprise the core of APE1. One of the strands comprises residues near the N-terminal region and a second strand is contributed by the C-terminal region of APE1, which serves as a mitochondrial targeting sequence. These terminal regions converge within the pocket defined by the CSPs. In the presence of a duplex DNA substrate mimic, removal of excess APX3330 resulted in refolding of APE1. Our results are consistent with a reversible mechanism of partial unfolding of APE1 induced by the small molecule inhibitor, APX3330, defining a novel mechanism of inhibition.
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Zaunz S, De Smedt J, Lauwereins L, Cleuren L, Laffeber C, Bajaj M, Lebbink JHG, Marteijn JA, De Keersmaecker K, Verfaillie C. APEX1 Nuclease and Redox Functions are Both Essential for Adult Mouse Hematopoietic Stem and Progenitor Cells. Stem Cell Rev Rep 2023:10.1007/s12015-023-10550-0. [PMID: 37266894 PMCID: PMC10390635 DOI: 10.1007/s12015-023-10550-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/27/2023] [Indexed: 06/03/2023]
Abstract
Self-renewal and differentiation of hematopoietic stem and progenitor cells (HSPCs) are carefully controlled by extrinsic and intrinsic factors, to ensure the lifelong process of hematopoiesis. Apurinic/apyrimidinic endonuclease 1 (APEX1) is a multifunctional protein implicated in DNA repair and transcriptional regulation. Although previous studies have emphasized the necessity of studying APEX1 in a lineage-specific context and its role in progenitor differentiation, no studies have assessed the role of APEX1, nor its two enzymatic domains, in supporting adult HSPC function. In this study, we demonstrated that complete loss of APEX1 from murine bone marrow HSPCs (induced by CRISPR/Cas9) caused severe hematopoietic failure following transplantation, as well as a HSPC expansion defect in culture conditions maintaining in vivo HSC functionality. Using specific inhibitors against either the nuclease or redox domains of APEX1 in combination with single cell transcriptomics (CITE-seq), we found that both APEX1 nuclease and redox domains are regulating mouse HSPCs, but through distinct underlying transcriptional changes. Inhibition of the APEX1 nuclease function resulted in loss of HSPCs accompanied by early activation of differentiation programs and enhanced lineage commitment. By contrast, inhibition of the APEX1 redox function significantly downregulated interferon-stimulated genes and regulons in expanding HSPCs and their progeny, resulting in dysfunctional megakaryocyte-biased HSPCs, as well as loss of monocytes and lymphoid progenitor cells. In conclusion, we demonstrate that APEX1 is a key regulator for adult regenerative hematopoiesis, and that the APEX1 nuclease and redox domains differently impact proliferating HSPCs.
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Affiliation(s)
- Samantha Zaunz
- Stem Cell Institute, Department of Development and Regeneration, KU Leuven, O&N IV Herestraat 49, 3000, Louvain, Belgium.
| | - Jonathan De Smedt
- Stem Cell Institute, Department of Development and Regeneration, KU Leuven, O&N IV Herestraat 49, 3000, Louvain, Belgium
- GlaxoSmithKline Biologicals SA, 1300, Wavre, Belgium
| | - Lukas Lauwereins
- Stem Cell Institute, Department of Development and Regeneration, KU Leuven, O&N IV Herestraat 49, 3000, Louvain, Belgium
| | - Lana Cleuren
- Stem Cell Institute, Department of Development and Regeneration, KU Leuven, O&N IV Herestraat 49, 3000, Louvain, Belgium
| | - Charlie Laffeber
- Department of Molecular Genetics, Oncode Institute, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Manmohan Bajaj
- Stem Cell Institute, Department of Development and Regeneration, KU Leuven, O&N IV Herestraat 49, 3000, Louvain, Belgium
| | - Joyce H G Lebbink
- Department of Molecular Genetics, Oncode Institute, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, Netherlands
- Department of Radiotherapy, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Jurgen A Marteijn
- Department of Molecular Genetics, Oncode Institute, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Kim De Keersmaecker
- Laboratory for Disease Mechanisms in Cancer, Department of Oncology, KU Leuven, Louvain, Belgium
| | - Catherine Verfaillie
- Stem Cell Institute, Department of Development and Regeneration, KU Leuven, O&N IV Herestraat 49, 3000, Louvain, Belgium
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5
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Pidugu LS, Servius HW, Sevdalis SE, Cook ME, Varney KM, Pozharski E, Drohat AC. Characterizing inhibitors of human AP endonuclease 1. PLoS One 2023; 18:e0280526. [PMID: 36652434 PMCID: PMC9847973 DOI: 10.1371/journal.pone.0280526] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 12/30/2022] [Indexed: 01/19/2023] Open
Abstract
AP endonuclease 1 (APE1) processes DNA lesions including apurinic/apyrimidinic sites and 3´-blocking groups, mediating base excision repair and single strand break repair. Much effort has focused on developing specific inhibitors of APE1, which could have important applications in basic research and potentially lead to clinical anticancer agents. We used structural, biophysical, and biochemical methods to characterize several reported inhibitors, including 7-nitroindole-2-carboxylic acid (CRT0044876), given its small size, reported potency, and widespread use for studying APE1. Intriguingly, NMR chemical shift perturbation (CSP) experiments show that CRT0044876 and three similar indole-2-carboxylic acids bind a pocket distal from the APE1 active site. A crystal structure confirms these findings and defines the pose for 5-nitroindole-2-carboxylic acid. However, dynamic light scattering experiments show the indole compounds form colloidal aggregates that could bind (sequester) APE1, causing nonspecific inhibition. Endonuclease assays show the compounds lack significant APE1 inhibition under conditions (detergent) that disrupt aggregation. Thus, binding of the indole-2-carboxylic acids at the remote pocket does not inhibit APE1 repair activity. Myricetin also forms aggregates and lacks APE1 inhibition under aggregate-disrupting conditions. Two other reported compounds (MLS000552981, MLS000419194) inhibit APE1 in vitro with low micromolar IC50 and do not appear to aggregate in this concentration range. However, NMR CSP experiments indicate the compounds do not bind specifically to apo- or Mg2+-bound APE1, pointing to a non-specific mode of inhibition, possibly DNA binding. Our results highlight methods for rigorous interrogation of putative APE1 inhibitors and should facilitate future efforts to discover compounds that specifically inhibit this important repair enzyme.
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Affiliation(s)
- Lakshmi S. Pidugu
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Hardler W. Servius
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Spiridon E. Sevdalis
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Mary E. Cook
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Kristen M. Varney
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Edwin Pozharski
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Center for Biomolecular Therapeutics, Institute for Bioscience and Biotechnology Research, Rockville, Maryland, United States of America
- * E-mail: (EP); (ACD)
| | - Alexander C. Drohat
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (EP); (ACD)
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6
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Changes in the Plasma Apurinic/Apyrimidinic Endonuclease 1/Redox Factor-1(APE1/Ref-1) Level during Cancer Surgery: An Observational Study. Medicina (B Aires) 2021; 57:medicina57111280. [PMID: 34833498 PMCID: PMC8623191 DOI: 10.3390/medicina57111280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/18/2021] [Accepted: 11/19/2021] [Indexed: 11/17/2022] Open
Abstract
Background and Objectives: Propofol-based total intravenous anesthesia (TIVA) is presumed to have more favorable effects on the prognosis of patients with cancer compared with volatile inhaled anesthesia (VIA). We hypothesized that these anesthetics target plasma apurinic apyrimidinic endonuclease/redox effector factor-1 (APE1/Ref-1) as a possible mechanism of action. Materials and Methods: The plasma APE1/Ref-1 level was evaluated three times during surgery for cancer, i.e., before anesthesia, immediately after cancer resection, and finally, in the recovery room. Blood (3 cc) was drawn from the radial artery catheter, and plasma APE1/Ref-1 levels were compared according to measurement time and between the two groups. Spearman’s Rho correlation analysis was performed to determine relationships among body mass index, American Society of Anesthesiologists classification, age, sex, cancer type, and tumor-node-metastasis (TNM) stage. A total of 166 patients (VIA: 129; TIVA: 37) were enrolled. Results: Plasma APE1/Ref-1 level increased significantly (p = 0.028) after cancer resection compared with before surgery, but no significant difference was observed between anesthetics (p = 0.134). The post-resection plasma APE1/Ref-1 level showed a positive correlation with the NM stages, but not the T stage. Conclusions: The plasma APE1/Ref-1 level increased during surgery with more severe lymph node invasion, but there were no significant differences according to the anesthetics used.
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Gampala S, Shah F, Lu X, Moon HR, Babb O, Umesh Ganesh N, Sandusky G, Hulsey E, Armstrong L, Mosely AL, Han B, Ivan M, Yeh JRJ, Kelley MR, Zhang C, Fishel ML. Ref-1 redox activity alters cancer cell metabolism in pancreatic cancer: exploiting this novel finding as a potential target. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2021; 40:251. [PMID: 34376225 PMCID: PMC8353735 DOI: 10.1186/s13046-021-02046-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 07/18/2021] [Indexed: 12/13/2022]
Abstract
BACKGROUND Pancreatic cancer is a complex disease with a desmoplastic stroma, extreme hypoxia, and inherent resistance to therapy. Understanding the signaling and adaptive response of such an aggressive cancer is key to making advances in therapeutic efficacy. Redox factor-1 (Ref-1), a redox signaling protein, regulates the conversion of several transcription factors (TFs), including HIF-1α, STAT3 and NFκB from an oxidized to reduced state leading to enhancement of their DNA binding. In our previously published work, knockdown of Ref-1 under normoxia resulted in altered gene expression patterns on pathways including EIF2, protein kinase A, and mTOR. In this study, single cell RNA sequencing (scRNA-seq) and proteomics were used to explore the effects of Ref-1 on metabolic pathways under hypoxia. METHODS scRNA-seq comparing pancreatic cancer cells expressing less than 20% of the Ref-1 protein was analyzed using left truncated mixture Gaussian model and validated using proteomics and qRT-PCR. The identified Ref-1's role in mitochondrial function was confirmed using mitochondrial function assays, qRT-PCR, western blotting and NADP assay. Further, the effect of Ref-1 redox function inhibition against pancreatic cancer metabolism was assayed using 3D co-culture in vitro and xenograft studies in vivo. RESULTS Distinct transcriptional variation in central metabolism, cell cycle, apoptosis, immune response, and genes downstream of a series of signaling pathways and transcriptional regulatory factors were identified in Ref-1 knockdown vs Scrambled control from the scRNA-seq data. Mitochondrial DEG subsets downregulated with Ref-1 knockdown were significantly reduced following Ref-1 redox inhibition and more dramatically in combination with Devimistat in vitro. Mitochondrial function assays demonstrated that Ref-1 knockdown and Ref-1 redox signaling inhibition decreased utilization of TCA cycle substrates and slowed the growth of pancreatic cancer co-culture spheroids. In Ref-1 knockdown cells, a higher flux rate of NADP + consuming reactions was observed suggesting the less availability of NADP + and a higher level of oxidative stress in these cells. In vivo xenograft studies demonstrated that tumor reduction was potent with Ref-1 redox inhibitor similar to Devimistat. CONCLUSION Ref-1 redox signaling inhibition conclusively alters cancer cell metabolism by causing TCA cycle dysfunction while also reducing the pancreatic tumor growth in vitro as well as in vivo.
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Affiliation(s)
- Silpa Gampala
- Department of Pediatrics and Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Fenil Shah
- Department of Pediatrics and Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Xiaoyu Lu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Department of Biohealth Informatics, IUPUI, Indianapolis, IN, 46202, USA
| | - Hye-Ran Moon
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, 47906, USA
| | - Olivia Babb
- Department of Pediatrics and Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Nikkitha Umesh Ganesh
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown, MA, 02115, USA.,Department of Medicine, Harvard Medical School, Boston, MA, 02115, USA
| | - George Sandusky
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine , Indianapolis, IN, 46202, USA.,Indiana University Simon Comprehensive Cancer Center, Indiana University School of Medicine, 1044 W Walnut St. R4-321, Indianapolis, IN, 46202, USA
| | - Emily Hulsey
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine , Indianapolis, IN, 46202, USA
| | - Lee Armstrong
- Department of Pediatrics and Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Amber L Mosely
- Indiana University Simon Comprehensive Cancer Center, Indiana University School of Medicine, 1044 W Walnut St. R4-321, Indianapolis, IN, 46202, USA.,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Bumsoo Han
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, 47906, USA.,Purdue Center for Cancer Research, Purdue University, West Lafayette, IN, 47906, USA
| | - Mircea Ivan
- Indiana University Simon Comprehensive Cancer Center, Indiana University School of Medicine, 1044 W Walnut St. R4-321, Indianapolis, IN, 46202, USA.,Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Jing-Ruey Joanna Yeh
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown, MA, 02115, USA.,Department of Medicine, Harvard Medical School, Boston, MA, 02115, USA
| | - Mark R Kelley
- Department of Pediatrics and Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Indiana University Simon Comprehensive Cancer Center, Indiana University School of Medicine, 1044 W Walnut St. R4-321, Indianapolis, IN, 46202, USA.,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Chi Zhang
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA. .,Department of Biohealth Informatics, IUPUI, Indianapolis, IN, 46202, USA. .,Indiana University Simon Comprehensive Cancer Center, Indiana University School of Medicine, 1044 W Walnut St. R4-321, Indianapolis, IN, 46202, USA.
| | - Melissa L Fishel
- Department of Pediatrics and Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, USA. .,Indiana University Simon Comprehensive Cancer Center, Indiana University School of Medicine, 1044 W Walnut St. R4-321, Indianapolis, IN, 46202, USA. .,Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
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Wilson DM, Deacon AM, Duncton MAJ, Pellicena P, Georgiadis MM, Yeh AP, Arvai AS, Moiani D, Tainer JA, Das D. Fragment- and structure-based drug discovery for developing therapeutic agents targeting the DNA Damage Response. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 163:130-142. [PMID: 33115610 PMCID: PMC8666131 DOI: 10.1016/j.pbiomolbio.2020.10.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/13/2020] [Accepted: 10/23/2020] [Indexed: 12/12/2022]
Abstract
Cancer will directly affect the lives of over one-third of the population. The DNA Damage Response (DDR) is an intricate system involving damage recognition, cell cycle regulation, DNA repair, and ultimately cell fate determination, playing a central role in cancer etiology and therapy. Two primary therapeutic approaches involving DDR targeting include: combinatorial treatments employing anticancer genotoxic agents; and synthetic lethality, exploiting a sporadic DDR defect as a mechanism for cancer-specific therapy. Whereas, many DDR proteins have proven "undruggable", Fragment- and Structure-Based Drug Discovery (FBDD, SBDD) have advanced therapeutic agent identification and development. FBDD has led to 4 (with ∼50 more drugs under preclinical and clinical development), while SBDD is estimated to have contributed to the development of >200, FDA-approved medicines. Protein X-ray crystallography-based fragment library screening, especially for elusive or "undruggable" targets, allows for simultaneous generation of hits plus details of protein-ligand interactions and binding sites (orthosteric or allosteric) that inform chemical tractability, downstream biology, and intellectual property. Using a novel high-throughput crystallography-based fragment library screening platform, we screened five diverse proteins, yielding hit rates of ∼2-8% and crystal structures from ∼1.8 to 3.2 Å. We consider current FBDD/SBDD methods and some exemplary results of efforts to design inhibitors against the DDR nucleases meiotic recombination 11 (MRE11, a.k.a., MRE11A), apurinic/apyrimidinic endonuclease 1 (APE1, a.k.a., APEX1), and flap endonuclease 1 (FEN1).
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Affiliation(s)
- David M Wilson
- Hasselt University, Biomedical Research Institute, Diepenbeek, Belgium; Boost Scientific, Heusden-Zolder, Belgium; XPose Therapeutics Inc., San Carlos, CA, USA
| | - Ashley M Deacon
- Accelero Biostructures Inc., San Francisco, CA, USA; XPose Therapeutics Inc., San Carlos, CA, USA
| | | | | | - Millie M Georgiadis
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA; XPose Therapeutics Inc., San Carlos, CA, USA
| | - Andrew P Yeh
- Accelero Biostructures Inc., San Francisco, CA, USA
| | - Andrew S Arvai
- Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Davide Moiani
- Department of Cancer Biology, MD Anderson Cancer Center, Houston, TX, USA; Department of Molecular and Cellular Oncology, MD Anderson Cancer Center, Houston, TX, USA
| | - John A Tainer
- Department of Cancer Biology, MD Anderson Cancer Center, Houston, TX, USA; Department of Molecular and Cellular Oncology, MD Anderson Cancer Center, Houston, TX, USA
| | - Debanu Das
- Accelero Biostructures Inc., San Francisco, CA, USA; XPose Therapeutics Inc., San Carlos, CA, USA.
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9
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Caffrey PJ, Delaney S. Chromatin and other obstacles to base excision repair: potential roles in carcinogenesis. Mutagenesis 2021; 35:39-50. [PMID: 31612219 DOI: 10.1093/mutage/gez029] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 09/13/2019] [Indexed: 12/29/2022] Open
Abstract
DNA is comprised of chemically reactive nucleobases that exist under a constant barrage from damaging agents. Failure to repair chemical modifications to these nucleobases can result in mutations that can cause various diseases, including cancer. Fortunately, the base excision repair (BER) pathway can repair modified nucleobases and prevent these deleterious mutations. However, this pathway can be hindered through several mechanisms. For instance, mutations to the enzymes in the BER pathway have been identified in cancers. Biochemical characterisation of these mutants has elucidated various mechanisms that inhibit their activity. Furthermore, the packaging of DNA into chromatin poses another obstacle to the ability of BER enzymes to function properly. Investigations of BER in the base unit of chromatin, the nucleosome core particle (NCP), have revealed that the NCP acts as a complex substrate for BER enzymes. The constituent proteins of the NCP, the histones, also have variants that can further impact the structure of the NCP and may modulate access of enzymes to the packaged DNA. These histone variants have also displayed significant clinical effects both in carcinogenesis and patient prognosis. This review focuses on the underlying molecular mechanisms that present obstacles to BER and the relationship of these obstacles to cancer. In addition, several chemotherapeutics induce DNA damage that can be repaired by the BER pathway and understanding obstacles to BER can inform how resistance and/or sensitivity to these therapies may occur. With the understanding of these molecular mechanisms, current chemotherapeutic treatment regiments may be improved, and future therapies developed.
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Affiliation(s)
- Paul J Caffrey
- Department of Chemistry, Brown University, Providence, RI
| | - Sarah Delaney
- Department of Chemistry, Brown University, Providence, RI
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10
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Cho J, Oh S, Lee D, Han JW, Yoo J, Park D, Lee G. Spectroscopic sensing and quantification of AP-endonucleases using fluorescence-enhancement by cis– trans isomerization of cyanine dyes. RSC Adv 2021; 11:11380-11386. [PMID: 35423644 PMCID: PMC8695990 DOI: 10.1039/d0ra08051a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 03/08/2021] [Indexed: 11/21/2022] Open
Abstract
Apurinic/apyrimidinic (AP) endonucleases are vital DNA repair enzymes, and proposed to be a prognostic biomarker for various types of cancer in humans. Numerous DNA sensors have been developed to evaluate the extent of nuclease activity but their DNA termini are not protected against other nucleases, hampering accurate quantification. Here we developed a new fluorescence enhancement (FE)-based method as an enzyme-specific DNA biosensor with nuclease-protection by three functional units (an AP-site, Cy3 and termini that are protected from exonucleolytic cleavage). A robust FE signal arises from the fluorescent cis–trans isomerization of a cyanine dye (e.g., Cy3) upon the enzyme-triggered structural change from double-stranded (ds)DNA to single-stranded (ss)DNA that carries Cy3. The FE-based assay reveals a linear dependency on sub-nanomolar concentrations as low as 10−11 M for the target enzyme and can be also utilized as a sensitive readout of other nuclease activities. Apurinic/apyrimidinic (AP) endonucleases are vital DNA repair enzymes, and proposed to be a prognostic biomarker for various types of cancer in humans.![]()
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Affiliation(s)
- JunHo Cho
- School of Life Sciences
- Gwangju Institute of Science and Technology
- Gwangju
- Korea
| | - Sanghoon Oh
- Department of Biomedical Science and Engineering
- Gwangju Institute of Science and Technology
- Gwangju
- Korea
| | - DongHun Lee
- School of Life Sciences
- Gwangju Institute of Science and Technology
- Gwangju
- Korea
| | - Jae Won Han
- School of Life Sciences
- Gwangju Institute of Science and Technology
- Gwangju
- Korea
| | - Jungmin Yoo
- School of Life Sciences
- Gwangju Institute of Science and Technology
- Gwangju
- Korea
| | - Daeho Park
- School of Life Sciences
- Gwangju Institute of Science and Technology
- Gwangju
- Korea
- Cell Mechanobiology Research Center
| | - Gwangrog Lee
- School of Life Sciences
- Gwangju Institute of Science and Technology
- Gwangju
- Korea
- Department of Biomedical Science and Engineering
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11
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Hu J, Wang Y, Yuan Y. Inhibitors of APE1 redox function effectively inhibit γ-herpesvirus replication in vitro and in vivo. Antiviral Res 2020; 185:104985. [PMID: 33271272 DOI: 10.1016/j.antiviral.2020.104985] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 11/12/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022]
Abstract
APE1 is a multi-functional protein with a redox function in its N-terminal domain and an apurinic/apyrimidinic endonuclease activity in the C-terminal domain. APE1 redox function plays an important role in regulating cell proliferation and survival through activating specific transcriptional activators. APE1 redox function is also found to be associated with some cancer occurrence. In this study, we demonstrated that APE1 redox function is essential for Epstein-Barr virus (EBV) lytic replication as the silencing of APE1 expression or treatment with APE1 redox inhibitors C10 and E3330 can inhibit EBV lytic replication and virion production. Furthermore, C10 and E3330 also inhibit MHV-68 replication in vitro and in vivo. C10 and E3330 were able to significantly reduce the loss of pulmonary alveoli and thickening of alveolar septa in mice caused by MHV-68 infection. Altogether, (i) APE1 redox function is validated as a new antiviral target; (ii) APE1 redox inhibitors, especially C10, have potentials to be used for the treatment of γ-herpesvirus infection and associated diseases; (iii) MHV-68 is validated to be a surrogate for the study of the pathogenesis and therapy of EBV and KSHV infection in vivo.
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Affiliation(s)
- Jiayuan Hu
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Yan Wang
- Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Yan Yuan
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China; Department of Basic and Translational Sciences, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, 19104, USA.
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12
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Association between apurinic/apyrimidinic endonuclease 1 rs1760944 T>G polymorphism and susceptibility of cancer: a meta-analysis involving 21764 subjects. Biosci Rep 2020; 39:221420. [PMID: 31804681 PMCID: PMC6923335 DOI: 10.1042/bsr20190866] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 10/03/2019] [Accepted: 12/04/2019] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Previous case-control studies have suggested that apurinic/apyrimidinic endonuclease 1 (APE1) rs1760944 T>G polymorphism may be associated with cancer risk. Here, we carried out an updated meta-analysis to focus on the correlation between APE1 rs1760944 T>G locus and the risk of cancer. METHODS We used the crude odds ratios (ORs) with their 95% confidence intervals (CIs) to evaluate the possible relationship between the APE1 rs1760944 T>G polymorphism and cancer risk. Heterogeneity, publication bias and sensitivity analysis were also harnessed to check the potential bias of the present study. RESULTS Twenty-three independent studies involving 10166 cancer cases and 11598 controls were eligible for this pooled analysis. We found that APE1 rs1760944 T>G polymorphism decreased the risk of cancer in four genetic models (G vs. T: OR, 0.87; 95% CI, 0.83-0.92; P<0.001; GG vs. TT: OR, 0.77; 95% CI, 0.69-0.86; P<0.001; GG/TG vs. TT: OR, 0.83; 95% CI, 0.77-0.89, P<0.001 and GG vs. TT/TG: OR, 0.85; 95% CI, 0.80-0.92, P<0.001). Results of subgroup analyses also demonstrated that this single-nucleotide polymorphism (SNP) modified the risk among lung cancer, breast cancer, osteosarcoma, and Asians. Evidence of publication bias was found in the present study. When we treated the publication bias with 'trim-and-fill' method, the adjusted ORs and CIs were not significantly changed. CONCLUSION In conclusion, current evidence highlights that the APE1 rs1760944 T>G polymorphism is a protective factor for cancer susceptibility. In the future, case-control studies with detailed risk factors are needed to confirm or refute our findings.
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13
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Sahakian L, Filippone RT, Stavely R, Robinson AM, Yan XS, Abalo R, Eri R, Bornstein JC, Kelley MR, Nurgali K. Inhibition of APE1/Ref-1 Redox Signaling Alleviates Intestinal Dysfunction and Damage to Myenteric Neurons in a Mouse Model of Spontaneous Chronic Colitis. Inflamm Bowel Dis 2020; 27:388-406. [PMID: 32618996 PMCID: PMC8287929 DOI: 10.1093/ibd/izaa161] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Inflammatory bowel disease (IBD) associates with damage to the enteric nervous system (ENS), leading to gastrointestinal (GI) dysfunction. Oxidative stress is important for the pathophysiology of inflammation-induced enteric neuropathy and GI dysfunction. Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a dual functioning protein that is an essential regulator of the cellular response to oxidative stress. In this study, we aimed to determine whether an APE1/Ref-1 redox domain inhibitor, APX3330, alleviates inflammation-induced oxidative stress that leads to enteric neuropathy in the Winnie murine model of spontaneous chronic colitis. METHODS Winnie mice received APX3330 or vehicle via intraperitoneal injections over 2 weeks and were compared with C57BL/6 controls. In vivo disease activity and GI transit were evaluated. Ex vivo experiments were performed to assess functional parameters of colonic motility, immune cell infiltration, and changes to the ENS. RESULTS Targeting APE1/Ref-1 redox activity with APX3330 improved disease severity, reduced immune cell infiltration, restored GI function ,and provided neuroprotective effects to the enteric nervous system. Inhibition of APE1/Ref-1 redox signaling leading to reduced mitochondrial superoxide production, oxidative DNA damage, and translocation of high mobility group box 1 protein (HMGB1) was involved in neuroprotective effects of APX3330 in enteric neurons. CONCLUSIONS This study is the first to investigate inhibition of APE1/Ref-1's redox activity via APX3330 in an animal model of chronic intestinal inflammation. Inhibition of the redox function of APE1/Ref-1 is a novel strategy that might lead to a possible application of APX3330 for the treatment of IBD.
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Affiliation(s)
- Lauren Sahakian
- Institute for Health and Sport, Victoria University; Western Centre for Health, Research and Education, Sunshine Hospital, Melbourne, Victoria, Australia
| | - Rhiannon T Filippone
- Institute for Health and Sport, Victoria University; Western Centre for Health, Research and Education, Sunshine Hospital, Melbourne, Victoria, Australia
| | - Rhian Stavely
- Institute for Health and Sport, Victoria University; Western Centre for Health, Research and Education, Sunshine Hospital, Melbourne, Victoria, Australia,Department of Pediatric Surgery, Pediatric Surgery Research Laboratories, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Ainsley M Robinson
- Institute for Health and Sport, Victoria University; Western Centre for Health, Research and Education, Sunshine Hospital, Melbourne, Victoria, Australia
| | - Xu Sean Yan
- Institute for Health and Sport, Victoria University; Western Centre for Health, Research and Education, Sunshine Hospital, Melbourne, Victoria, Australia
| | - Raquel Abalo
- Área de Farmacología y Nutrición y Unidad Asociada al Instituto de Química Médica (IQM) del Consejo Superior de Investigaciones Científicas (CSIC), Universidad Rey Juan Carlos (URJC), Alcorcón, Madrid, Spain,High Performance Research Group in Physiopathology and Pharmacology of the Digestive System at URJC, Alcorcón, Madrid, Spain
| | - Rajaraman Eri
- University of Tasmania, School of Health Sciences, Launceston, Tasmania, Australia
| | - Joel C Bornstein
- Department of Physiology, Melbourne University, Melbourne, Australia
| | - Mark R Kelley
- Indiana University Simon Comprehensive Cancer Center, Departments of Pediatrics, Biochemistry & Molecular Biology and Pharmacology & Toxicology, Program in Pediatric Molecular Oncology & Experimental Therapeutics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine Indianapolis, USA
| | - Kulmira Nurgali
- Institute for Health and Sport, Victoria University; Western Centre for Health, Research and Education, Sunshine Hospital, Melbourne, Victoria, Australia,Department of Medicine Western Health, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia,Regenerative Medicine and Stem Cells Program, Australian Institute of Musculoskeletal Science (AIMSS), Melbourne, Victoria, Australia,Address correspondence to: Kulmira Nurgali, Level 4, Research Labs, Western Centre for Health Research & Education, Sunshine Hospital, 176 Furlong Road, St Albans, 3021, VIC, Australia. E-mail:
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14
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Liu Y, Zhang Z, Li Q, Zhang L, Cheng Y, Zhong Z. Mitochondrial APE1 promotes cisplatin resistance by downregulating ROS in osteosarcoma. Oncol Rep 2020; 44:499-508. [PMID: 32627008 PMCID: PMC7336412 DOI: 10.3892/or.2020.7633] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 04/22/2020] [Indexed: 01/20/2023] Open
Abstract
Apurinic/apyrimidinic endonuclease 1 (APE1) is a primary nuclear-localized multifunctional protein in osteosarcoma. However, the cytoplasmic localization of APE1 was found to be functional and to increase with cisplatin resistance, yet the molecular mechanism is unknown. In the present study, we explored the cisplatin resistance mechanism in osteosarcoma from the new perspective of APE1 extranuclear biological activity. Using cisplatin-resistant and cisplatin-sensitive osteosarcoma cell lines, we found that mitochondrial APE1 (mtAPE1) was overexpressed in cisplatin-resistant cells but not in sensitive cells. Overexpression of mtAPE1 reduced cisplatin-induced apoptosis, while knockdown of APE1 reversed this phenomenon and caused oxidative DNA damage via overproduction of reactive oxygen species (ROS). We further demonstrated that high mtAPE1 expression could downregulate ROS production by decreasing the phosphorylation of Rac1 (p-Rac1), further promoting cisplatin resistance in osteosarcoma. Our findings suggest that mitochondrial APE1 promotes cisplatin resistance by decreasing ROS generation, which may provide new ideas for researching the molecular mechanism of osteosarcoma chemoresistance and strategies to overcome cisplatin resistance in osteosarcoma.
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Affiliation(s)
- Yufeng Liu
- Cancer Center, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing 400038, P.R. China
| | - Zhimin Zhang
- Cancer Center, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing 400038, P.R. China
| | - Qing Li
- Cancer Center, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing 400038, P.R. China
| | - Liang Zhang
- Cancer Center, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing 400038, P.R. China
| | - Yi Cheng
- Cancer Center, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing 400038, P.R. China
| | - Zhaoyang Zhong
- Cancer Center, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing 400038, P.R. China
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15
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Fishel ML, Xia H, McGeown J, McIlwain DW, Elbanna M, Craft AA, Kaimakliotis HZ, Sandusky GE, Zhang C, Pili R, Kelley MR, Jerde TJ. Antitumor Activity and Mechanistic Characterization of APE1/Ref-1 Inhibitors in Bladder Cancer. Mol Cancer Ther 2019; 18:1947-1960. [PMID: 31413178 DOI: 10.1158/1535-7163.mct-18-1166] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 04/15/2019] [Accepted: 08/05/2019] [Indexed: 12/17/2022]
Abstract
Bladder cancer is the ninth most common cause of cancer-related deaths worldwide. Although cisplatin is used routinely in treating bladder cancer, refractory disease remains lethal for many patients. The recent addition of immunotherapy has improved patient outcomes; however, a large cohort of patients does not respond to these treatments. Therefore, identification of innovative molecular targets for bladder cancer is crucial. Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein involved in both DNA repair and activation of transcription factors through reduction-oxidation (redox) regulation. High APE1/Ref-1 expression is associated with shorter patient survival time in many cancer types. In this study, we found high APE1/Ref-1 expression in human bladder cancer tissue relative to benign urothelium. Inhibition of APE1/Ref-1 redox signaling using APE1/Ref-1-specific inhibitors attenuates bladder cancer cell proliferation in monolayer, in three-dimensional cultures, and in vivo. This inhibition corresponds with an increase in apoptosis and decreased transcriptional activity of NF-κB and STAT3, transcription factors known to be regulated by APE1/Ref-1, resulting in decreased expression of downstream effectors survivin and Cyclin D1 in vitro and in vivo. We also demonstrate that in vitro treatment of bladder cancer cells with APE1/Ref-1 redox inhibitors in combination with standard-of-care chemotherapy cisplatin is more effective than cisplatin alone at inhibiting cell proliferation. Collectively, our data demonstrate that APE1/Ref-1 is a viable drug target for the treatment of bladder cancer, provide a mechanism of APE1/Ref-1 action in bladder cancer cells, and support the use of novel redox-selective APE1/Ref-1 inhibitors in clinical studies. SIGNIFICANCE: This work identifies a critical mechanism for APE1/Ref-1 in bladder cancer growth and provides compelling preclinical data using selective redox activity inhibitors of APE1/Ref-1 in vitro and in vivo.
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Affiliation(s)
- Melissa L Fishel
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Hanyu Xia
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jack McGeown
- Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana.,University of Ulster, Coleraine, Northern Ireland
| | - David W McIlwain
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - May Elbanna
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Ariel A Craft
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana
| | | | - George E Sandusky
- Department of Pathology and Laboratory Medicine, Indiana University Simon Cancer Center, Indianapolis, Indiana
| | - Chi Zhang
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana
| | - Roberto Pili
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Urology, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Hematology and Oncology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Mark R Kelley
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Travis J Jerde
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana. .,Department of Urology, Indiana University School of Medicine, Indianapolis, Indiana
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16
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Li H, Zhong C, Wang Q, Chen W, Yuan Y. Curcumin is an APE1 redox inhibitor and exhibits an antiviral activity against KSHV replication and pathogenesis. Antiviral Res 2019; 167:98-103. [PMID: 31034848 DOI: 10.1016/j.antiviral.2019.04.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 04/18/2019] [Accepted: 04/23/2019] [Indexed: 01/06/2023]
Abstract
Curcumin, a polyphenol, is the main bioactive compound in dietary spice turmeric curcuma longa. It possesses anti-inflammatory, anti-oxidant and anti-neoplastic properties and shows potentials in treating or preventing particular diseases such as oxidative and inflammatory conditions, metabolic syndrome, arthritis, anxiety, hyperlipidemia and cancers. The diverse range and potential health beneficial effects has generated enthusiasm leading to intensive investigation into the phytochemical. However, a concern has been also raised if curcumin has a promiscuous bioassay profile and is a Pan-Assay INterference compound (PAINS). Here we present evidence indicating that curcumin is not a PAINS, but an inhibitor to APE1 redox function that affects many genes and pathways. This discovery explains the wide range of effects of curcumin on diverse human diseases and predicts a potential application in treatment of viral infection and virus-associated cancer. As a proof-of-concept, we demonstrated that curcumin is able to efficiently block Kaposi's sarcoma-associated herpesvirus replication and inhibit the pathogenic processes of angiogenesis and cell invasion.
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Affiliation(s)
- He Li
- Department of Microbiology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, 19104, USA; Department of Pharmacology, College of Pharmacy, Beihua University, Jilin, China
| | - Canrong Zhong
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Qian Wang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Weikang Chen
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Yan Yuan
- Department of Microbiology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, 19104, USA; Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China.
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17
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Trilles R, Beglov D, Chen Q, He H, Wireman R, Reed A, Chennamadhavuni S, Panek JS, Brown LE, Vajda S, Porco JA, Kelley MR, Georgiadis MM. Discovery of Macrocyclic Inhibitors of Apurinic/Apyrimidinic Endonuclease 1. J Med Chem 2019; 62:1971-1988. [PMID: 30653918 DOI: 10.1021/acs.jmedchem.8b01529] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Apurinic/apyrimidinic endonuclease 1 (APE1) is an essential base excision repair enzyme that is upregulated in a number of cancers, contributes to resistance of tumors treated with DNA-alkylating or -oxidizing agents, and has recently been identified as an important therapeutic target. In this work, we identified hot spots for binding of small organic molecules experimentally in high resolution crystal structures of APE1 and computationally through the use of FTMAP analysis ( http://ftmap.bu.edu/ ). Guided by these hot spots, a library of drug-like macrocycles was docked and then screened for inhibition of APE1 endonuclease activity. In an iterative process, hot-spot-guided docking, characterization of inhibition of APE1 endonuclease, and cytotoxicity of cancer cells were used to design next generation macrocycles. To assess target selectivity in cells, selected macrocycles were analyzed for modulation of DNA damage. Taken together, our studies suggest that macrocycles represent a promising class of compounds for inhibition of APE1 in cancer cells.
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Affiliation(s)
- Richard Trilles
- Department of Chemistry and Center for Molecular Discovery (BU-CMD) , Boston University , Boston , Massachusetts 02215 , United States
| | - Dmitri Beglov
- Department of Biomedical Engineering , Boston University , Boston , Massachusetts 02215 , United States
| | | | | | | | | | - Spandan Chennamadhavuni
- Department of Chemistry and Center for Molecular Discovery (BU-CMD) , Boston University , Boston , Massachusetts 02215 , United States
| | - James S Panek
- Department of Chemistry and Center for Molecular Discovery (BU-CMD) , Boston University , Boston , Massachusetts 02215 , United States
| | - Lauren E Brown
- Department of Chemistry and Center for Molecular Discovery (BU-CMD) , Boston University , Boston , Massachusetts 02215 , United States
| | - Sandor Vajda
- Department of Biomedical Engineering , Boston University , Boston , Massachusetts 02215 , United States
| | - John A Porco
- Department of Chemistry and Center for Molecular Discovery (BU-CMD) , Boston University , Boston , Massachusetts 02215 , United States
| | | | - Millie M Georgiadis
- Department of Chemistry and Chemical Biology, Purdue School of Science , Indiana University-Purdue University Indianapolis , Indianapolis , Indiana 46202 , United States
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18
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Dynamic coordination of two-metal-ions orchestrates λ-exonuclease catalysis. Nat Commun 2018; 9:4404. [PMID: 30353000 PMCID: PMC6199318 DOI: 10.1038/s41467-018-06750-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 09/22/2018] [Indexed: 11/08/2022] Open
Abstract
Metal ions at the active site of an enzyme act as cofactors, and their dynamic fluctuations can potentially influence enzyme activity. Here, we use λ-exonuclease as a model enzyme with two Mg2+ binding sites and probe activity at various concentrations of magnesium by single-molecule-FRET. We find that while MgA2+ and MgB2+ have similar binding constants, the dissociation rate of MgA2+ is two order of magnitude lower than that of MgB2+ due to a kinetic-barrier-difference. At physiological Mg2+ concentration, the MgB2+ ion near the 5'-terminal side of the scissile phosphate dissociates each-round of degradation, facilitating a series of DNA cleavages via fast product-release concomitant with enzyme-translocation. At a low magnesium concentration, occasional dissociation and slow re-coordination of MgA2+ result in pauses during processive degradation. Our study highlights the importance of metal-ion-coordination dynamics in correlation with the enzymatic reaction-steps, and offers insights into the origin of dynamic heterogeneity in enzymatic catalysis.
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19
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Wang G, Zhang D, Yang S, Wang Y, Tang Z, Fu X. Co-administration of genistein with doxorubicin-loaded polypeptide nanoparticles weakens the metastasis of malignant prostate cancer by amplifying oxidative damage. Biomater Sci 2018; 6:827-835. [PMID: 29480308 DOI: 10.1039/c7bm01201b] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Prostate cancer is a typical malignant disease with a high incidence and a poor prognosis. Doxorubicin hydrochloride (DOX·HCl) is one of the most effective agents in the treatment of prostate cancer, but severe side effects and metastasis after its treatment impose restrictions on its application. Herein, a combination of genistein (GEN) and doxorubicin-loaded polypeptide nanoparticles (DOX-NPs) is constructed for the treatment of prostate cancer. The DOX-NPs can reduce the side effects caused by free DOX·HCl and produce a relatively low level of intracellular reactive oxygen species (ROS)-induced oxidative damage, while GEN, an inhibitor of the oxidative DNA repair enzyme apurinic/apyrimidinic endonuclease1 (APE1), can further amplify the ROS-induced oxidative damage by downregulating the intracellular expression of APE1 and reducing oxidative DNA repair in the prostate cancer cells. Because high levels of ROS-induced oxidative damage can prevent the distant metastasis of tumor cells, the distant metastasis of malignant prostate cancer cells is significantly inhibited by the combination of genistein and DOX-NPs with amplified oxidative damage.
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Affiliation(s)
- Guanyi Wang
- Edmond H. Fischer Signal Transduction Laboratory, College of Life Sciences, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China.
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20
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Sengupta S, Mantha AK, Song H, Roychoudhury S, Nath S, Ray S, Bhakat KK. Elevated level of acetylation of APE1 in tumor cells modulates DNA damage repair. Oncotarget 2018; 7:75197-75209. [PMID: 27655688 PMCID: PMC5342734 DOI: 10.18632/oncotarget.12113] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 09/02/2016] [Indexed: 12/20/2022] Open
Abstract
Apurinic/apyrimidinic (AP) sites are frequently generated in the genome by spontaneous depurination/depyrimidination or after removal of oxidized/modified bases by DNA glycosylases during the base excision repair (BER) pathway. Unrepaired AP sites are mutagenic and block DNA replication and transcription. The primary enzyme to repair AP sites in mammalian cells is AP endonuclease (APE1), which plays a key role in this repair pathway. Although overexpression of APE1 in diverse cancer types and its association with chemotherapeutic resistance are well documented, alteration of posttranslational modification of APE1 and modulation of its functions during tumorigenesis are largely unknown. Here, we show that both classical histone deacetylase HDAC1 and NAD+-dependent deacetylase SIRT1 regulate acetylation level of APE1 and acetylation of APE1 enhances its AP-endonuclease activity both in vitro and in cells. Modulation of APE1 acetylation level in cells alters AP site repair capacity of the cell extracts in vitro. Primary tumor tissues of diverse cancer types have higher level of acetylated APE1 (AcAPE1) compared to adjacent non-tumor tissue and exhibit enhanced AP site repair capacity. Importantly, in the absence of APE1 acetylation, cells accumulate AP sites in the genome and show increased sensitivity to DNA damaging agents. Together, our study demonstrates that elevation of acetylation level of APE1 in tumor could be a novel mechanism by which cells handle the elevated levels of DNA damages in response to genotoxic stress and maintain sustained proliferation.
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Affiliation(s)
- Shiladitya Sengupta
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX 77030 , USA
| | - Anil K Mantha
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Center for Animal Sciences, School of Basic and Applied Sciences, Central University of Punjab, Bathinda 151001, Punjab, India
| | - Heyu Song
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Shrabasti Roychoudhury
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Somsubhra Nath
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA.,Molecular Biology Research & Diagnostic Laboratory, Saroj Gupta Cancer Centre & Research Institute, Kolkata 700063, India
| | - Sutapa Ray
- Department of Pediatrics, Hematology/Oncology Division, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Kishor K Bhakat
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
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21
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McIlwain DW, Fishel ML, Boos A, Kelley MR, Jerde TJ. APE1/Ref-1 redox-specific inhibition decreases survivin protein levels and induces cell cycle arrest in prostate cancer cells. Oncotarget 2018; 9:10962-10977. [PMID: 29541389 PMCID: PMC5834255 DOI: 10.18632/oncotarget.23493] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 09/15/2017] [Indexed: 01/23/2023] Open
Abstract
A key feature of prostate cancer progression is the induction and activation of survival proteins, including the Inhibitor of Apoptosis (IAP) family member survivin. Apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional protein that is essential in activating oncogenic transcription factors. Because APE1/Ref-1 is expressed and elevated in prostate cancer, we sought to characterize APE1/Ref-1 expression and activity in human prostate cancer cell lines and determine the effect of selective reduction-oxidation (redox) function inhibition on prostate cancer cells in vitro and in vivo. Due to the role of oncogenic transcriptional activators NFĸB and STAT3 in survivin protein expression, and APE1/Ref-1 redox activity regulating their transcriptional activity, we assessed selective inhibition of APE1/Ref-1's redox function as a novel method to halt prostate cancer cell growth and survival. Our study demonstrates that survivin and APE1/Ref-1 are significantly higher in human prostate cancer specimens compared to noncancerous controls and that APE1/Ref-1 redox-specific inhibition with small molecule inhibitor, APX3330 and a second-generation inhibitor, APX2009, decreases prostate cancer cell proliferation and induces cell cycle arrest. Inhibition of APE1/Ref-1 redox function significantly reduced NFĸB transcriptional activity, survivin mRNA and survivin protein levels. These data indicate that APE1/Ref-1 is a key regulator of survivin and a potentially viable target in prostate cancer.
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Affiliation(s)
- David W. McIlwain
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Melissa L. Fishel
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Alexander Boos
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Mark R. Kelley
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Travis J. Jerde
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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22
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Shah F, Goossens E, Atallah NM, Grimard M, Kelley MR, Fishel ML. APE1/Ref-1 knockdown in pancreatic ductal adenocarcinoma - characterizing gene expression changes and identifying novel pathways using single-cell RNA sequencing. Mol Oncol 2017; 11:1711-1732. [PMID: 28922540 PMCID: PMC5709621 DOI: 10.1002/1878-0261.12138] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 08/24/2017] [Accepted: 09/02/2017] [Indexed: 12/18/2022] Open
Abstract
Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1 or APE1) is a multifunctional protein that regulates numerous transcription factors associated with cancer-related pathways. Because APE1 is essential for cell viability, generation of APE1-knockout cell lines and determining a comprehensive list of genes regulated by APE1 has not been possible. To circumvent this challenge, we utilized single-cell RNA sequencing to identify differentially expressed genes (DEGs) in relation to APE1 protein levels within the cell. Using a straightforward yet novel statistical design, we identified 2837 genes whose expression is significantly changed following APE1 knockdown. Using this gene expression profile, we identified multiple new pathways not previously linked to APE1, including the EIF2 signaling and mechanistic target of Rapamycin pathways and a number of mitochondrial-related pathways. We demonstrate that APE1 has an effect on modifying gene expression up to a threshold of APE1 expression, demonstrating that it is not necessary to completely knockout APE1 in cells to accurately study APE1 function. We validated the findings using a selection of the DEGs along with siRNA knockdown and qRT-PCR. Testing additional patient-derived pancreatic cancer cells reveals particular genes (ITGA1, TNFAIP2, COMMD7, RAB3D) that respond to APE1 knockdown similarly across all the cell lines. Furthermore, we verified that the redox function of APE1 was responsible for driving gene expression of mitochondrial genes such as PRDX5 and genes that are important for proliferation such as SIPA1 and RAB3D by treating with APE1 redox-specific inhibitor, APX3330. Our study identifies several novel genes and pathways affected by APE1, as well as tumor subtype specificity. These findings will allow for hypothesis-driven approaches to generate combination therapies using, for example, APE1 inhibitor APX3330 with other approved FDA drugs in an innovative manner for pancreatic and other cancer treatments.
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Affiliation(s)
- Fenil Shah
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Emery Goossens
- Department of Statistics, Purdue University, West Lafayette, IN, USA
| | - Nadia M Atallah
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, USA
| | - Michelle Grimard
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Mark R Kelley
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Melissa L Fishel
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
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23
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Wei S, Perera MLW, Sakhtemani R, Bhagwat AS. A novel class of chemicals that react with abasic sites in DNA and specifically kill B cell cancers. PLoS One 2017; 12:e0185010. [PMID: 28926604 PMCID: PMC5605088 DOI: 10.1371/journal.pone.0185010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 09/05/2017] [Indexed: 01/06/2023] Open
Abstract
Most B cell cancers overexpress the enzyme activation-induced deaminase at high levels and this enzyme converts cytosines in DNA to uracil. The constitutive expression of this enzyme in these cells greatly increases the uracil content of their genomes. We show here that these genomes also contain high levels of abasic sites presumably created during the repair of uracils through base-excision repair. We further show that three alkoxyamines with an alkyne functional group covalently link to abasic sites in DNA and kill immortalized cell lines created from B cell lymphomas, but not other cancers. They also do not kill normal B cells. Treatment of cancer cells with one of these chemicals causes strand breaks, and the sensitivity of the cells to this chemical depends on the ability of the cells to go through the S phase. However, other alkoxyamines that also link to abasic sites- but lack the alkyne functionality- do not kill cells from B cell lymphomas. This shows that the ability of alkoxyamines to covalently link to abasic sites is insufficient for their cytotoxicity and that the alkyne functionality may play a role in it. These chemicals violate the commonly accepted bioorthogonality of alkynes and are attractive prototypes for anti-B cell cancer agents.
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Affiliation(s)
- Shanqiao Wei
- Department of Chemistry, Wayne State University, Detroit, Michigan, United States of America
| | - Madusha L. W. Perera
- Department of Chemistry, Wayne State University, Detroit, Michigan, United States of America
| | - Ramin Sakhtemani
- Department of Chemistry, Wayne State University, Detroit, Michigan, United States of America
| | - Ashok S. Bhagwat
- Department of Chemistry, Wayne State University, Detroit, Michigan, United States of America
- Immunology and Microbiology, Wayne State University, Detroit, Michigan, United States of America
- * E-mail:
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24
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Xiao X, Yang Y, Ren Y, Zou D, Zhang K, Wu Y. rs1760944 Polymorphism in the APE1 Region is Associated with Risk and Prognosis of Osteosarcoma in the Chinese Han Population. Sci Rep 2017; 7:9331. [PMID: 28839218 PMCID: PMC5570937 DOI: 10.1038/s41598-017-09750-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 06/16/2017] [Indexed: 01/16/2023] Open
Abstract
The effects of single nucleotide polymorphisms (SNPs) at APE1 have been investigated in several types of cancer. However, no reports of the association of APE1 polymorphisms with osteosarcoma (OS) have been published. The present study was designed to determine whether APE1 polymorphisms (rs1130409, rs1760944, rs1760941, rs2275008, rs17111750) are associated with OS. A 2-stage case-control study was performed in a total of 378 OS patients and 616 normal controls. Individuals carrying TG and GG genotypes had significantly lower risk of developing OS than those with the WT genotype TT at rs1760944 (OR = 0.65, 95%CI 0.49–0.86; OR = 0.50, 95%CI 0.34–0.74, respectively). OS patients with allele G at rs1760944 were less susceptible to low differentiation tumor and metastasis (OR = 0.73, 95%CI 0.54–0.98; OR = 0.63, 95%CI 0.43–0.92, respectively). Kaplan-Meier curves and log-rank results revealed that OS patients harboring genotype GG and G allele at rs1760944 had better survival (P < 0.001 for both). In addition, the APE1 protein was underexpressed in individuals who carried G allele at rs1760944. This study suggested that APE1 rs1760944 polymorphism is associated with decreased risk of developing OS and better survival of OS patients.
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Affiliation(s)
- Xing Xiao
- Department of Spine Surgery, Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China
| | - Yun Yang
- School of Medicine, Shandong University, Jinan, Shandong, China
| | - Yanjun Ren
- Department of Spine Surgery, Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China
| | - Debo Zou
- Department of Spine Surgery, Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China
| | - Kaining Zhang
- Department of Spine Surgery, Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China
| | - Yingguang Wu
- Department of Spine Surgery, Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China.
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25
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Abstract
Reduction-oxidation factor 1-apurinic/apyrimidinic endonuclease (Ref-1/APE1) is a critical node in tumor cells, both as a redox regulator of transcription factor activation and as part of the DNA damage response. As a redox signaling protein, Ref-1/APE1 enhances the transcriptional activity of STAT3, HIF-1α, nuclear factor kappa B, and other transcription factors to promote growth, migration, and survival in tumor cells as well as inflammation and angiogenesis in the tumor microenvironment. Ref-1/APE1 is activated in a variety of cancers, including prostate, colon, pancreatic, ovarian, lung and leukemias, leading to increased aggressiveness. Transcription factors downstream of Ref-1/APE1 are key contributors to many cancers, and Ref-1/APE1 redox signaling inhibition slows growth and progression in a number of tumor types. Ref-1/APE1 inhibition is also highly effective when paired with other drugs, including standard-of-care therapies and therapies targeting pathways affected by Ref-1/APE1 redox signaling. Additionally, Ref-1/APE1 plays a role in a variety of other indications, such as retinopathy, inflammation, and neuropathy. In this review, we discuss the functional consequences of activation of the Ref-1/APE1 node in cancer and other diseases, as well as potential therapies targeting Ref-1/APE1 and related pathways in relevant diseases. APX3330, a novel oral anticancer agent and the first drug to target Ref-1/APE1 for cancer is entering clinical trials and will be explored in various cancers and other diseases bringing bench discoveries to the clinic.
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26
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Zhong C, Xu M, Wang Y, Xu J, Yuan Y. An APE1 inhibitor reveals critical roles of the redox function of APE1 in KSHV replication and pathogenic phenotypes. PLoS Pathog 2017; 13:e1006289. [PMID: 28380040 PMCID: PMC5381946 DOI: 10.1371/journal.ppat.1006289] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Accepted: 03/11/2017] [Indexed: 01/04/2023] Open
Abstract
APE1 is a multifunctional protein with a DNA base excision repair function in its C-terminal domain and a redox activity in its N-terminal domain. The redox function of APE1 converts certain transcription factors from inactive oxidized to active reduced forms. Given that among the APE1-regulated transcription factors many are critical for KSHV replication and pathogenesis, we investigated whether inhibition of APE1 redox function blocks KSHV replication and Kaposi’s sarcoma (KS) phenotypes. With an shRNA-mediated silencing approach and a known APE-1 redox inhibitor, we demonstrated that APE1 redox function is indeed required for KSHV replication as well as KSHV-induced angiogenesis, validating APE1 as a therapeutic target for KSHV-associated diseases. A ligand-based virtual screening yielded a small molecular compound, C10, which is proven to bind to APE1. C10 exhibits low cytotoxicity but efficiently inhibits KSHV lytic replication (EC50 of 0.16 μM and selective index of 165) and KSHV-mediated pathogenic phenotypes including cytokine production, angiogenesis and cell invasion, demonstrating its potential to become an effective drug for treatment of KS. As a major AIDS-associated malignancy, Kaposi’s sarcoma (KS) is caused by Kaposi’s sarcoma-associated herpesvirus (KSHV). Currently there is no definitive cure for KS. In this study, we identified a cellular protein, namely APE1, as an effective therapeutic target for blocking KSHV replication and inhibiting the development of KS phenotypes. We showed that the redox function of APE1 is absolutely required for KSHV replication, virally induced cytokine secretion and angiogenesis. Blockade of APE1 expression or inhibition of APE1 redox activity led to inhibition of KSHV replication and reduction of cytokine release and angiogenesis. Furthermore, we identified a novel small molecular compound, C10, which exhibited specific inhibitory activity on APE1 redox function and was demonstrated to efficiently inhibit KSHV replication and paracrine-mediated KS phenotypes such as angiogenesis and cell invasion. As a potent inhibitor of APE1 redox, C10 not only has value in development of a novel therapeutics for KS, but also may be used in therapies for other human diseases such as leukemia, pancreatic cancer and macular degeneration.
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Affiliation(s)
- Canrong Zhong
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China
- Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Mengyang Xu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Yan Wang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China
- Guanghua School of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Jun Xu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, Guangdong, China
- * E-mail: (YY); (JX)
| | - Yan Yuan
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China
- Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, Guangdong, China
- Department of Microbiology, University of Pennsylvania School of Dental Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail: (YY); (JX)
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27
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Valdés A, García-Cañas V, Pérez-Sánchez A, Barrajón-Catalán E, Ruiz-Torres V, Artemenko KA, Micol V, Bergquist J, Cifuentes A. Shotgun proteomic analysis to study the decrease of xenograft tumor growth after rosemary extract treatment. J Chromatogr A 2017; 1499:90-100. [PMID: 28389096 DOI: 10.1016/j.chroma.2017.03.072] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 03/23/2017] [Accepted: 03/25/2017] [Indexed: 12/18/2022]
Abstract
The antiproliferative activity of Rosemary (Rosmarinus officinalis) has been widely studied in different in vitro and in vivo models, which demonstrate that rosemary extracts inhibit the cellular proliferation due to its ability to interact with a wide spectrum of molecular targets. However, a comprehensive proteomics study in vivo has not been carried out yet. In the present work, the effects of rosemary extract on xenograft tumor growth has been studied and, for the first time, a shotgun proteomic analysis based on nano-LC-MS/MS together with stable isotope dimethyl labeling (DML) has been applied to investigate the global protein changes in vivo. Our results show that the daily administration of a polyphenol-enriched rosemary extract reduces the progression of colorectal cancer in vivo with the subsequent deregulation of 74 proteins. The bioinformatic analysis of these proteins indicates that the rosemary extract mainly alters the RNA Post-Transcriptional Modification, the Protein Synthesis and the Amino Acid Metabolism functions and suggests the inactivation of the oncogene MYC. These results demonstrate the high utility of the proposed analytical methodology to determine, simultaneously, the expression levels of a large number of protein biomarkers and to generate new hypothesis about the molecular mechanisms of this extract in vivo.
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Affiliation(s)
- Alberto Valdés
- Laboratory of Foodomics, Institute of Food Science Research (CIAL, CSIC), Nicolas Cabrera 9, 28049, Madrid, Spain
| | - Virginia García-Cañas
- Molecular Nutrition and Metabolism, Institute of Food Science Research (CIAL, CSIC), Nicolas Cabrera 9, 28049 Madrid, Spain
| | - Almudena Pérez-Sánchez
- Institute of Molecular and Cellular Biology, Miguel Hernández University, Avda. Universidad s/n, Elche 03202, Spain
| | - Enrique Barrajón-Catalán
- Institute of Molecular and Cellular Biology, Miguel Hernández University, Avda. Universidad s/n, Elche 03202, Spain
| | - Verónica Ruiz-Torres
- Institute of Molecular and Cellular Biology, Miguel Hernández University, Avda. Universidad s/n, Elche 03202, Spain
| | - Konstantin A Artemenko
- Analytical Chemistry, Department of Chemistry-BMC, Uppsala University, Husargatan 3, 75124 Uppsala, Sweden
| | - Vicente Micol
- Institute of Molecular and Cellular Biology, Miguel Hernández University, Avda. Universidad s/n, Elche 03202, Spain; CIBER, Fisiopatología de la Obesidad y la Nutrición, CIBERobn, Instituto de Salud Carlos III (CB12/03/30038), Spain
| | - Jonas Bergquist
- Analytical Chemistry, Department of Chemistry-BMC, Uppsala University, Husargatan 3, 75124 Uppsala, Sweden
| | - Alejandro Cifuentes
- Laboratory of Foodomics, Institute of Food Science Research (CIAL, CSIC), Nicolas Cabrera 9, 28049, Madrid, Spain.
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28
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Laev SS, Salakhutdinov NF, Lavrik OI. Inhibitors of nuclease and redox activity of apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1). Bioorg Med Chem 2017; 25:2531-2544. [PMID: 28161249 DOI: 10.1016/j.bmc.2017.01.028] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 01/16/2017] [Accepted: 01/18/2017] [Indexed: 01/15/2023]
Abstract
Human apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional protein which is essential in the base excision repair (BER) pathway of DNA lesions caused by oxidation and alkylation. This protein hydrolyzes DNA adjacent to the 5'-end of an apurinic/apyrimidinic (AP) site to produce a nick with a 3'-hydroxyl group and a 5'-deoxyribose phosphate moiety or activates the DNA-binding activity of certain transcription factors through its redox function. Studies have indicated a role for APE1/Ref-1 in the pathogenesis of cancer and in resistance to DNA-interactive drugs. Thus, this protein has potential as a target in cancer treatment. As a result, major efforts have been directed to identify small molecule inhibitors against APE1/Ref-1 activities. These agents have the potential to become anticancer drugs. The aim of this review is to present recent progress in studies of all published small molecule APE1/Ref-1 inhibitors. The structures and activities of APE1/Ref-1 inhibitors, that target both DNA repair and redox activities, are presented and discussed. To date, there is an urgent need for further development of the design and synthesis of APE1/Ref-1 inhibitors due to high importance of this protein target.
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Affiliation(s)
- Sergey S Laev
- Vorozhtsov Institute of Organic Chemistry, Siberian Division, Russian Academy of Sciences, pr. akademika Lavrent'eva 9, Novosibirsk 630090, Russian Federation.
| | - Nariman F Salakhutdinov
- Vorozhtsov Institute of Organic Chemistry, Siberian Division, Russian Academy of Sciences, pr. akademika Lavrent'eva 9, Novosibirsk 630090, Russian Federation; Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090, Russian Federation
| | - Olga I Lavrik
- Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090, Russian Federation; Novosibirsk Institute of Chemical Biology and Fundamental Medicine, Siberian Division, Russian Academy of Sciences, pr. akademika Lavrent'eva 8, Novosibirsk 630090, Russian Federation
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29
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Gong Z, Lu R, Xie S, Jiang M, Liu K, Xiao R, Shen J, Wang Y, Guo L. Overexpression of pro-gastrin releasing peptide promotes the cell proliferation and progression in small cell lung cancer. Biochem Biophys Res Commun 2016; 479:312-318. [DOI: 10.1016/j.bbrc.2016.09.066] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 09/13/2016] [Indexed: 01/01/2023]
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30
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Wen X, Lu R, Xie S, Zheng H, Wang H, Wang Y, Sun J, Gao X, Guo L. APE1 overexpression promotes the progression of ovarian cancer and serves as a potential therapeutic target. Cancer Biomark 2016; 17:313-322. [DOI: 10.3233/cbm-160643] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Xuemei Wen
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Renquan Lu
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Suhong Xie
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Hui Zheng
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Hongling Wang
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Yanchun Wang
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Jiajun Sun
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Xiang Gao
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Lin Guo
- Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
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31
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Aamann MD, Nørregaard R, Kristensen MLV, Stevnsner T, Frøkiær J. Unilateral ureteral obstruction induces DNA repair by APE1. Am J Physiol Renal Physiol 2015; 310:F763-F776. [PMID: 26608791 DOI: 10.1152/ajprenal.00613.2014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 11/23/2015] [Indexed: 02/05/2023] Open
Abstract
Ureteral obstruction is associated with oxidative stress and the development of fibrosis of the kidney parenchyma. Apurinic/apyrimidinic endonuclease (APE1) is an essential DNA repair enzyme for repair of oxidative DNA lesions and regulates several transcription factors. The aim of the present study was to investigate whether APE1 is regulated by acute (24 h) and chronic (7 days) unilateral ureteral obstruction (UUO). APE1 was expressed in essentially all kidney cells with the strongest expression in proximal tubuli. After 24 h of UUO, APE1 mRNA was induced in the cortex, inner stripe of the outer medulla (ISOM), and inner medulla (IM). In contrast, the APE1 protein level was not regulated in the IM and ISOM and only slightly increased in the cortex. APE1 DNA repair activity was not significantly changed. A different pattern of regulation was observed after 7 days of UUO, with an increase of the APE1 mRNA level in the cortex but not in the ISOM and IM. The APE1 protein level in the cortex, ISOM, and IM increased significantly. Importantly, we observed a significant increase in APE1 DNA repair activity in the cortex and IM. To confirm our model, we investigated heme oxygenase-1, collagen type I, fibronectin I, and α-smooth muscle actin levels. In vitro, we found the transcriptional regulatory activity of APE1 to be involved in the upregulation of the profibrotic factor connective tissue growth factor. In summary, APE1 is regulated at different levels after acute and chronic UUO. Thus, our results suggest that DNA repair activity is regulated in response to progressive (7 days) obstruction and that APE1 potentially could play a role in the development of fibrosis in kidney disease.
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Affiliation(s)
- Maria D Aamann
- Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Rikke Nørregaard
- Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | | | - Tinna Stevnsner
- Danish Center for Molecular Gerontology and Danish Aging Research Center, Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark; and
| | - Jørgen Frøkiær
- Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark; .,Department of Clinical Physiology and Molecular Imaging, Aarhus University Hospital, Aarhus, Denmark
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Jiang S, Zhu L, Tang H, Zhang M, Chen Z, Fei J, Han B, Zou GM. Ape1 regulates WNT/β-catenin signaling through its redox functional domain in pancreatic cancer cells. Int J Oncol 2015; 47:610-20. [PMID: 26081414 DOI: 10.3892/ijo.2015.3048] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 04/06/2015] [Indexed: 11/05/2022] Open
Abstract
Apurinic/apyrimidinic endonuclease 1/redox factor-1 (Ape1/Ref-1, Ape1) is a multifunctional protein that is upregulated in human pancreatic cancer. Ape1 redox domain plays an essential role in regulating the effects of reactive oxygen species (ROS) generated during physiological metabolism and pathological stress. In the present study, we explored whether Ape1 and ROS affect WNT/β-catenin signaling. We used E3330, a small molecule inhibitor of the redox activity of Ape1, and a siRNA approach to knock down Ape1, in two human pancreatic cancer cell lines. Inhibition of Ape1 resulted in growth suppression of pancreatic cancer cells, increased ROS levels, upregulation of β-catenin and c-myc and downregulation of cyclin D1. Consistent with these data, overexpression of Ape1 in pancreatic cancer cells reduced ROS and c-myc levels and increased cyclin D1 levels. Moreover, treatment of pancreatic cancer cells with H2O2 to induce oxidative stress resulted in upregulated ROS levels, decreased Ape1 at both the mRNA and protein level, and alterations in WNT/β-catenin pathway components. Finally, treatment of pancreatic cancer cells with the WNT/β-catenin inhibitor IWR-1 resulted in growth inhibition, which was greatly enhanced when combined with E3330 treatment. In summary, our results demonstrate that ROS is an important intracellular messenger that can modulate WNT/β‑catenin signaling. The present study provides interesting new insight into crosstalk between the redox function of Ape1 and WNT/β-catenin signaling in cancer cells. Furthermore, our data show that the combination of Ape1 and WNT inhibitors enhanced the inhibition of pancreatic cell proliferation. These results provide a promising novel therapeutic strategy for treating pancreatic cancer in future.
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Affiliation(s)
- Shaojie Jiang
- Department of Radiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, P.R. China
| | - Lina Zhu
- Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Haimei Tang
- Biomedical Research Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, P.R. China
| | - Miaofeng Zhang
- Department of Orthopaedics, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Zhihua Chen
- Xin Hua Hospital, Shanghai Key Laboratory for Pediatrics Gastroenterology and Nutrition, Shanghai Institute for Pediatrics Research, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, P.R. China
| | - Jian Fei
- Department of Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, P.R. China
| | - Baosan Han
- Department of Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, P.R. China
| | - Gang-Ming Zou
- Xin Hua Hospital, Shanghai Key Laboratory for Pediatrics Gastroenterology and Nutrition, Shanghai Institute for Pediatrics Research, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, P.R. China
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Montaldi AP, Godoy PRDV, Sakamoto-Hojo ET. APE1/REF-1 down-regulation enhances the cytotoxic effects of temozolomide in a resistant glioblastoma cell line. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 793:19-29. [PMID: 26520369 DOI: 10.1016/j.mrgentox.2015.06.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 06/02/2015] [Indexed: 01/25/2023]
Abstract
Temozolomide (TMZ) is widely used for patients with glioblastoma (GBM); however, tumor cells frequently exhibit drug-resistance. Base excision repair (BER) has been identified as a possible mediator of TMZ resistance, and an attractive approach to sensitizing cells to chemotherapy. Human apurinic/apyrimidinic endonuclease/redox factor-1 (APE1) is an essential enzyme with a role in the BER pathway by repairing abasic sites, and it also acts as a reduction factor, maintaining transcription factors in an active reduced state. Thus, we aimed to investigate whether the down-regulation of APE1 expression by siRNA can interfere with the resistance of GBM to TMZ, being evaluated by several cellular and molecular parameters. We demonstrated that APE1 knockdown associated with TMZ treatment efficiently reduced cell proliferation and clonogenic survival of resistant cells (T98G), which appears to be a consequence of increased DNA damage, S-phase arrest, and H2AX phosphorylation, resulting in apoptosis induction. On the contrary, for those assays, the sensitization effects of APE1 silencing plus TMZ treatment did not occur in the TMZ-sensitive cell line (U87MG). Interestingly, TMZ-treatment and APE1 knockdown significantly reduced cell invasion in both cell lines, but TMZ alone did not reduce the invasion capacity of U87MG cells, as observed for T98G. We also found that VEGF expression was down-regulated by TMZ treatment in T98G cells, regardless of APE1 knockdown, but U87MG showed a different response, since APE1 silencing counteracted VEGF induction promoted by TMZ, suggesting that the APE1-redox function may play an indirect role, depending on the cell line. The present results support the contribution of BER in the GBM resistance to TMZ, with a greater effect in TMZ-resistant, compared with TMZ-sensitive cells, emphasizing that APE1 can be a promising target for modifying TMZ tolerance. Furthermore, genetic characteristics of tumor cells should be considered as critical information to select an appropriate therapeutic strategy.
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Affiliation(s)
- Ana P Montaldi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Brazil; Department of Biology, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto - University of São Paulo (USP), Ribeirão Preto, S.P., Brazil
| | - Paulo R D V Godoy
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Brazil; Department of Biology, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto - University of São Paulo (USP), Ribeirão Preto, S.P., Brazil
| | - Elza T Sakamoto-Hojo
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Brazil; Department of Biology, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto - University of São Paulo (USP), Ribeirão Preto, S.P., Brazil.
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Fishel ML, Wu X, Devlin CM, Logsdon DP, Jiang Y, Luo M, He Y, Yu Z, Tong Y, Lipking KP, Maitra A, Rajeshkumar NV, Scandura G, Kelley MR, Ivan M. Apurinic/apyrimidinic endonuclease/redox factor-1 (APE1/Ref-1) redox function negatively regulates NRF2. J Biol Chem 2014; 290:3057-68. [PMID: 25492865 DOI: 10.1074/jbc.m114.621995] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Apurinic/apyrimidinic endonuclease/redox factor-1 (APE1/Ref-1) (henceforth referred to as Ref-1) is a multifunctional protein that in addition to its base excision DNA repair activity exerts redox control of multiple transcription factors, including nuclear factor κ-light chain enhancer of activated B cells (NF-κB), STAT3, activator protein-1 (AP-1), hypoxia-inducible factor-1 (HIF-1), and tumor protein 53 (p53). In recent years, Ref-1 has emerged as a promising therapeutic target in cancer, particularly in pancreatic ductal carcinoma. Although a significant amount of research has centered on Ref-1, no wide-ranging approach had been performed on the effects of Ref-1 inhibition and transcription factor activity perturbation. Starting with a broader approach, we identified a previously unsuspected effect on the nuclear factor erythroid-related factor 2 (NRF2), a critical regulator of cellular defenses against oxidative stress. Based on genetic and small molecule inhibitor-based methodologies, we demonstrated that repression of Ref-1 potently activates NRF2 and its downstream targets in a dose-dependent fashion, and that the redox, rather than the DNA repair function of Ref-1 is critical for this effect. Intriguingly, our results also indicate that this pathway does not involve reactive oxygen species. The link between Ref-1 and NRF2 appears to be present in all cells tested in vitro, noncancerous and cancerous, including patient-derived tumor samples. In particular, we focused on understanding the implications of the novel interaction between these two pathways in primary pancreatic ductal adenocarcinoma tumor cells and provide the first evidence that this mechanism has implications for overcoming the resistance against experimental drugs targeting Ref-1 activity, with clear translational implications.
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Affiliation(s)
- Melissa L Fishel
- From the Departments of Pediatrics, Wells Center for Pediatric Research, Pharmacology and Toxicology,
| | - Xue Wu
- Microbiology and Immunology
| | | | | | - Yanlin Jiang
- From the Departments of Pediatrics, Wells Center for Pediatric Research
| | - Meihua Luo
- From the Departments of Pediatrics, Wells Center for Pediatric Research, Pharmacology and Toxicology
| | - Ying He
- From the Departments of Pediatrics, Wells Center for Pediatric Research
| | | | | | - Kelsey P Lipking
- Pathology, Indiana University School of Medicine, Indianapolis, Indiana 46202 and
| | - Anirban Maitra
- the Departments of Oncology and Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - N V Rajeshkumar
- the Departments of Oncology and Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | | | - Mark R Kelley
- From the Departments of Pediatrics, Wells Center for Pediatric Research, Pharmacology and Toxicology
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Kaur G, Cholia RP, Mantha AK, Kumar R. DNA repair and redox activities and inhibitors of apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1): a comparative analysis and their scope and limitations toward anticancer drug development. J Med Chem 2014; 57:10241-56. [PMID: 25280182 DOI: 10.1021/jm500865u] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional enzyme involved in DNA repair and activation of transcription factors through its redox function. The evolutionarily conserved C- and N-termini are involved in these functions independently. It is also reported that the activity of APE1/Ref-1 abruptly increases several-fold in various human cancers. The control over the outcomes of these two functions is emerging as a new strategy to combine enhanced DNA damage and chemotherapy in order to tackle the major hurdle of increased cancer cell growth and proliferation. Studies have targeted these two domains individually for the design and development of inhibitors for APE1/Ref-1. Here, we have made, for the first time, an attempt at a comparative analysis of APE1/Ref-1 inhibitors that target both DNA repair and redox activities simultaneously. We further discuss their scope and limitations with respect to the development of potential anticancer agents.
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Affiliation(s)
- Gagandeep Kaur
- Laboratory for Drug Design and Synthesis, Centre for Chemical and Pharmaceutical Sciences, School of Basic and Applied Sciences, Central University of Punjab , Bathinda, 151001, Punjab, India
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Human AP endonuclease 1: a potential marker for the prediction of environmental carcinogenesis risk. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:730301. [PMID: 25243052 PMCID: PMC4158471 DOI: 10.1155/2014/730301] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 06/30/2014] [Indexed: 12/15/2022]
Abstract
Human apurinic/apyrimidinic endonuclease 1 (APE1) functions mainly in DNA repair as an enzyme removing AP sites and in redox signaling as a coactivator of various transcription factors. Based on these multifunctions of APE1 within cells, numerous studies have reported that the alteration of APE1 could be a crucial factor in development of human diseases such as cancer and neurodegeneration. In fact, the study on the combination of an individual's genetic make-up with environmental factors (gene-environment interaction) is of great importance to understand the development of diseases, especially lethal diseases including cancer. Recent reports have suggested that the human carcinogenic risk following exposure to environmental toxicants is affected by APE1 alterations in terms of gene-environment interactions. In this review, we initially outline the critical APE1 functions in the various intracellular mechanisms including DNA repair and redox regulation and its roles in human diseases. Several findings demonstrate that the change in expression and activity as well as genetic variability of APE1 caused by environmental chemical (e.g., heavy metals and cigarette smoke) and physical carcinogens (ultraviolet and ionizing radiation) is likely associated with various cancers. These enable us to ultimately suggest APE1 as a vital marker for the prediction of environmental carcinogenesis risk.
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37
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Li Y, Liu X, Zhou T, Kelley MR, Edwards P, Gao H, Qiao X. Inhibition of APE1/Ref-1 redox activity rescues human retinal pigment epithelial cells from oxidative stress and reduces choroidal neovascularization. Redox Biol 2014; 2:485-94. [PMID: 24624338 PMCID: PMC3949093 DOI: 10.1016/j.redox.2014.01.023] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 01/29/2014] [Accepted: 01/31/2014] [Indexed: 02/06/2023] Open
Abstract
The effectiveness of current treatment for age related macular degeneration (AMD) by targeting one molecule is limited due to its multifactorial nature and heterogeneous pathologies. Treatment strategy to target multiple signaling pathways or pathological components in AMD pathogenesis is under investigation for better clinical outcome. Inhibition of the redox function of apurinic endonuclease 1/redox factor-1 (APE1) was found to suppress endothelial angiogenesis and promote neuronal cell recovery, thereby may serve as a potential treatment for AMD. In the current study, we for the first time have found that a specific inhibitor of APE1 redox function by a small molecule compound E3330 regulates retinal pigment epithelium (RPEs) cell response to oxidative stress. E3330 significantly blocked sub-lethal doses of oxidized low density lipoprotein (oxLDL) induced proliferation decline and senescence advancement of RPEs. At the same time, E3330 remarkably decreased the accumulation of intracellular reactive oxygen species (ROS) and down-regulated the productions of monocyte chemoattractant protein-1 (MCP-1) and vascular endothelial growth factor (VEGF), as well as attenuated the level of nuclear factor-κB (NF-κB) p65 in RPEs. A panel of stress and toxicity responsive transcription factors that were significantly upregulated by oxLDL was restored by E3330, including Nrf2/Nrf1, p53, NF-κB, HIF1, CBF/NF-Y/YY1, and MTF-1. Further, a single intravitreal injection of E3330 effectively reduced the progression of laser-induced choroidal neovascularization (CNV) in mouse eyes. These data revealed that E3330 effectively rescued RPEs from oxidative stress induced senescence and dysfunctions in multiple aspects in vitro, and attenuated laser-induced damages to RPE–Bruch׳s membrane complex in vivo. Together with its previously established anti-angiogenic and neuroprotection benefits, E3330 is implicated for potential use for AMD treatment. Specific inhibition of APE1/Ref-1 redox function with E3330 blocked RPE proliferation decline and senescence-like phenotype advancement induced by oxLDL. E3330 suppressed intracellular ROS, down-regulated the MCP-1 and VEGF production, and reduced nuclear NF-κB p65 in RPEs. E3330 repressed the redox sensitive transcription factors Nrf2/Nrf1, p53, NF-κB, HIF1, CBF/NF-Y/YY1, and MTF-1 that stimulated by oxLDL in RPEs. Intravitreal injection of E3330 markedly reduced the laser-induced CNV in mouse eyes. E3330 holds great potential for the management of AMD.
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Key Words
- AMD, age related macular degeneration
- AP-1, activator protein 1
- APE1, apurinic endonuclease 1/redox factor-1
- APE1/Ref-1redox function
- Age-related macular degeneration.
- AhR, aryl hydrocarbon receptor
- ApoE, apolipoprotein E
- CBF/NF-Y/YY1, CCAAT binding factor/nuclear factor-Y/Yin Yang 1
- CECs, choroidal endothelial cells
- CNV, choroidal neovascularization
- DCFH-DA, dichlorodihydrofluorescin diacetate
- DMSO, dimethylsulphoxide
- E3330
- Fluc, firefly luciferase
- HIF-1α, hypoxia inducible factor-1α
- HSF1, heat-shock factor 1
- IκB-α, inhibitory NF-κB-α
- MCP-1, monocyte chemoattractant protein-1
- MTF1, metal regulatory transcription factor 1
- NF-κB, nuclear factor-κB
- Nox, NADPH oxidase
- Nrf, nuclear factor erythroid-2-related factor
- Oxidative stress
- RNV, retinal neovascularization
- ROS, reactive oxygen species
- RPE, retinal pigment epithelium
- RVECs, retinal vascular endothelial cells
- Retinal pigment epithelial cell
- Rluc, renilla luciferase
- SA-β-gal, senescence associated β-gal
- SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis
- TUNEL, TdT mediated dUTP-fluorescein nick end-labeling
- Transcription factor
- VEGF, vascular endothelial growth factor
- oxLDL, oxidized low density lipoprotein
- redox, reduction/oxidation
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Affiliation(s)
- Y Li
- Department of Ophthalmology, Henry Ford Health System, 1 Ford Place 5D, Detroit, MI, United States ; Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi׳an, Shanxi, People׳s Republic of China
| | - X Liu
- Department of Ophthalmology, Henry Ford Health System, 1 Ford Place 5D, Detroit, MI, United States
| | - T Zhou
- Department of Ophthalmology, Henry Ford Health System, 1 Ford Place 5D, Detroit, MI, United States
| | - M R Kelley
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, United States
| | - P Edwards
- Department of Ophthalmology, Henry Ford Health System, 1 Ford Place 5D, Detroit, MI, United States
| | - H Gao
- Department of Ophthalmology, Henry Ford Health System, 1 Ford Place 5D, Detroit, MI, United States
| | - X Qiao
- Department of Ophthalmology, Henry Ford Health System, 1 Ford Place 5D, Detroit, MI, United States
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Abstract
SIGNIFICANCE Human apurinic/apyrimidinic endonuclease 1 (APE1, also known as REF-1) was isolated based on its ability to cleave at AP sites in DNA or activate the DNA binding activity of certain transcription factors. We review herein topics related to this multi-functional DNA repair and stress-response protein. RECENT ADVANCES APE1 displays homology to Escherichia coli exonuclease III and is a member of the divalent metal-dependent α/β fold-containing phosphoesterase superfamily of enzymes. APE1 has acquired distinct active site and loop elements that dictate substrate selectivity, and a unique N-terminus which at minimum imparts nuclear targeting and interaction specificity. Additional activities ascribed to APE1 include 3'-5' exonuclease, 3'-repair diesterase, nucleotide incision repair, damaged or site-specific RNA cleavage, and multiple transcription regulatory roles. CRITICAL ISSUES APE1 is essential for mouse embryogenesis and contributes to cell viability in a genetic background-dependent manner. Haploinsufficient APE1(+/-) mice exhibit reduced survival, increased cancer formation, and cellular/tissue hyper-sensitivity to oxidative stress, supporting the notion that impaired APE1 function associates with disease susceptibility. Although abnormal APE1 expression/localization has been seen in cancer and neuropathologies, and impaired-function variants have been described, a causal link between an APE1 defect and human disease remains elusive. FUTURE DIRECTIONS Ongoing efforts aim at delineating the biological role(s) of the different APE1 activities, as well as the regulatory mechanisms for its intra-cellular distribution and participation in diverse molecular pathways. The determination of whether APE1 defects contribute to human disease, particularly pathologies that involve oxidative stress, and whether APE1 small-molecule regulators have clinical utility, is central to future investigations.
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Affiliation(s)
- Mengxia Li
- Intramural Research Program, Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health , Baltimore, Maryland
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Antoniali G, Lirussi L, Poletto M, Tell G. Emerging roles of the nucleolus in regulating the DNA damage response: the noncanonical DNA repair enzyme APE1/Ref-1 as a paradigmatical example. Antioxid Redox Signal 2014; 20:621-39. [PMID: 23879289 PMCID: PMC3901381 DOI: 10.1089/ars.2013.5491] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 07/22/2013] [Indexed: 12/25/2022]
Abstract
SIGNIFICANCE An emerging concept in DNA repair mechanisms is the evidence that some key enzymes, besides their role in the maintenance of genome stability, display also unexpected noncanonical functions associated with RNA metabolism in specific subcellular districts (e.g., nucleoli). During the evolution of these key enzymes, the acquisition of unfolded domains significantly amplified the possibility to interact with different partners and substrates, possibly explaining their phylogenetic gain of functions. RECENT ADVANCES After nucleolar stress or DNA damage, many DNA repair proteins can freely relocalize from nucleoli to the nucleoplasm. This process may represent a surveillance mechanism to monitor the synthesis and correct assembly of ribosomal units affecting cell cycle progression or inducing p53-mediated apoptosis or senescence. CRITICAL ISSUES A paradigm for this kind of regulation is represented by some enzymes of the DNA base excision repair (BER) pathway, such as apurinic/apyrimidinic endonuclease 1 (APE1). In this review, the role of the nucleolus and the noncanonical functions of the APE1 protein are discussed in light of their possible implications in human pathologies. FUTURE DIRECTIONS A productive cross-talk between DNA repair enzymes and proteins involved in RNA metabolism seems reasonable as the nucleolus is emerging as a dynamic functional hub that coordinates cell growth arrest and DNA repair mechanisms. These findings will drive further analyses on other BER proteins and might imply that nucleic acid processing enzymes are more versatile than originally thought having evolved DNA-targeted functions after a previous life in the early RNA world.
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Affiliation(s)
- Giulia Antoniali
- Department of Medical and Biological Sciences, University of Udine , Udine, Italy
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Sengupta S, Mitra S, Bhakat KK. Dual regulatory roles of human AP-endonuclease (APE1/Ref-1) in CDKN1A/p21 expression. PLoS One 2013; 8:e68467. [PMID: 23874636 PMCID: PMC3713036 DOI: 10.1371/journal.pone.0068467] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 05/29/2013] [Indexed: 01/02/2023] Open
Abstract
The human AP-endonuclease (APE1/Ref-1), an essential multifunctional protein involved in repair of oxidative DNA damage as well as in transcriptional regulation, is often overexpressed in tumor cells. APE1 was earlier shown to stimulate p53's DNA binding and its transactivation function in the expression of cyclin-dependent kinase inhibitor p21 (CDKN1A) gene. Here, we show APE1's stable binding to p53 cis elements which are required for p53-mediated activation of p21 in p53-expressing wild type HCT116 cells. However, surprisingly, we observed APE1-dependent repression of p21 in isogenic p53-null HCT116 cells. Ectopic expression of p53 in the p53-null cells abrogated this repression suggesting that APE1's negative regulatory role in p21 expression is dependent on the p53 status. We then identified APE1's another binding site in p21's proximal promoter region containing cis elements for AP4, a repressor of p21. Interestingly, APE1 and AP4 showed mutual dependence for p21 repression. Moreover, ectopic p53 in p53-null cells inhibited AP4's association with APE1, their binding to the promoter and p21 repression. These results together establish APE1's role as a co-activator or co-repressor of p21 gene, dependent on p53 status. It is thus likely that APE1 overexpression and inactivation of p53, often observed in tumor cells, promote tumor cell proliferation by constitutively downregulating p21 expression.
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Affiliation(s)
- Shiladitya Sengupta
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Sankar Mitra
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Kishor K. Bhakat
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas, United States of America
- * E-mail:
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Kim MH, Kim HB, Yoon SP, Lim SC, Cha MJ, Jeon YJ, Park SG, Chang IY, You HJ. Colon cancer progression is driven by APEX1-mediated upregulation of Jagged. J Clin Invest 2013; 123:65521. [PMID: 23863623 PMCID: PMC3726152 DOI: 10.1172/jci65521] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 04/25/2013] [Indexed: 02/05/2023] Open
Abstract
Aberrant expression of apurinic-apyrimidinic endonuclease-1 (APEX1) has been reported in numerous human solid tumors and is positively correlated with cancer progression; however, the role of APEX1 in tumor progression is poorly defined. Here, we show that APEX1 contributes to aggressive colon cancer behavior and functions as an upstream activator in the Jagged1/Notch signaling pathway. APEX1 overexpression or knockdown in human colon cancer cell lines induced profound changes in malignant properties such as cell proliferation, anchorage-independent growth, migration, invasion, and angiogenesis in vitro and in tumor formation and metastasis in mouse xenograft models. These oncogenic effects of APEX1 were mediated by the upregulation of Jagged1, a major Notch ligand. Furthermore, APEX1 expression was associated with Jagged1 in various colon cancer cell lines and in tissues from colon cancer patients. This finding identifies APEX1 as a positive regulator of Jagged1/Notch activity and suggests that it is a potential therapeutic target in colon cancers that exhibit high levels of Jagged1/Notch signaling.
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Affiliation(s)
- Mi-Hwa Kim
- DNA Damage Response Network Center, Chosun University, Gwangju, Republic of Korea.
Department of Pharmacology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Anatomy, School of Medicine, Jeju National University, Jeju-Do, Republic of Korea.
Department of Pathology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Hemato-oncology, Chosun University Hospital Internal Medicine, Gwangju, Republic of Korea.
Department of Anatomy, Chosun University School of Medicine, Gwangju, Republic of Korea
| | - Hong-Beum Kim
- DNA Damage Response Network Center, Chosun University, Gwangju, Republic of Korea.
Department of Pharmacology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Anatomy, School of Medicine, Jeju National University, Jeju-Do, Republic of Korea.
Department of Pathology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Hemato-oncology, Chosun University Hospital Internal Medicine, Gwangju, Republic of Korea.
Department of Anatomy, Chosun University School of Medicine, Gwangju, Republic of Korea
| | - Sang Pil Yoon
- DNA Damage Response Network Center, Chosun University, Gwangju, Republic of Korea.
Department of Pharmacology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Anatomy, School of Medicine, Jeju National University, Jeju-Do, Republic of Korea.
Department of Pathology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Hemato-oncology, Chosun University Hospital Internal Medicine, Gwangju, Republic of Korea.
Department of Anatomy, Chosun University School of Medicine, Gwangju, Republic of Korea
| | - Sung-Chul Lim
- DNA Damage Response Network Center, Chosun University, Gwangju, Republic of Korea.
Department of Pharmacology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Anatomy, School of Medicine, Jeju National University, Jeju-Do, Republic of Korea.
Department of Pathology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Hemato-oncology, Chosun University Hospital Internal Medicine, Gwangju, Republic of Korea.
Department of Anatomy, Chosun University School of Medicine, Gwangju, Republic of Korea
| | - Man Jin Cha
- DNA Damage Response Network Center, Chosun University, Gwangju, Republic of Korea.
Department of Pharmacology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Anatomy, School of Medicine, Jeju National University, Jeju-Do, Republic of Korea.
Department of Pathology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Hemato-oncology, Chosun University Hospital Internal Medicine, Gwangju, Republic of Korea.
Department of Anatomy, Chosun University School of Medicine, Gwangju, Republic of Korea
| | - Young Jin Jeon
- DNA Damage Response Network Center, Chosun University, Gwangju, Republic of Korea.
Department of Pharmacology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Anatomy, School of Medicine, Jeju National University, Jeju-Do, Republic of Korea.
Department of Pathology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Hemato-oncology, Chosun University Hospital Internal Medicine, Gwangju, Republic of Korea.
Department of Anatomy, Chosun University School of Medicine, Gwangju, Republic of Korea
| | - Sang Gon Park
- DNA Damage Response Network Center, Chosun University, Gwangju, Republic of Korea.
Department of Pharmacology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Anatomy, School of Medicine, Jeju National University, Jeju-Do, Republic of Korea.
Department of Pathology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Hemato-oncology, Chosun University Hospital Internal Medicine, Gwangju, Republic of Korea.
Department of Anatomy, Chosun University School of Medicine, Gwangju, Republic of Korea
| | - In-Youb Chang
- DNA Damage Response Network Center, Chosun University, Gwangju, Republic of Korea.
Department of Pharmacology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Anatomy, School of Medicine, Jeju National University, Jeju-Do, Republic of Korea.
Department of Pathology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Hemato-oncology, Chosun University Hospital Internal Medicine, Gwangju, Republic of Korea.
Department of Anatomy, Chosun University School of Medicine, Gwangju, Republic of Korea
| | - Ho Jin You
- DNA Damage Response Network Center, Chosun University, Gwangju, Republic of Korea.
Department of Pharmacology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Anatomy, School of Medicine, Jeju National University, Jeju-Do, Republic of Korea.
Department of Pathology, Chosun University School of Medicine, Gwangju, Republic of Korea.
Department of Hemato-oncology, Chosun University Hospital Internal Medicine, Gwangju, Republic of Korea.
Department of Anatomy, Chosun University School of Medicine, Gwangju, Republic of Korea
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Zhang J, Luo M, Marasco D, Logsdon D, LaFavers KA, Chen Q, Reed A, Kelley MR, Gross ML, Georgiadis MM. Inhibition of apurinic/apyrimidinic endonuclease I's redox activity revisited. Biochemistry 2013; 52:2955-66. [PMID: 23597102 PMCID: PMC3706204 DOI: 10.1021/bi400179m] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The essential base excision repair protein, apurinic/apyrimidinic endonuclease 1 (APE1), plays an important role in redox regulation in cells and is currently targeted for the development of cancer therapeutics. One compound that binds APE1 directly is (E)-3-[2-(5,6-dimethoxy-3-methyl-1,4-benzoquinonyl)]-2-nonylpropenoic acid (E3330). Here, we revisit the mechanism by which this negatively charged compound interacts with APE1 and inhibits its redox activity. At high concentrations (millimolar), E3330 interacts with two regions in the endonuclease active site of APE1, as mapped by hydrogen-deuterium exchange mass spectrometry. However, this interaction lowers the melting temperature of APE1, which is consistent with a loss of structure in APE1, as measured by both differential scanning fluorimetry and circular dichroism. These results are consistent with other findings that E3330 concentrations of >100 μM are required to inhibit APE1's endonuclease activity. To determine the role of E3330's negatively charged carboxylate in redox inhibition, we converted the carboxylate to an amide by synthesizing (E)-2-[(4,5-dimethoxy-2-methyl-3,6-dioxocyclohexa-1,4-dien-1-yl)methylene]-N-methoxy-undecanamide (E3330-amide), a novel uncharged derivative. E3330-amide has no effect on the melting temperature of APE1, suggesting that it does not interact with the fully folded protein. However, E3330-amide inhibits APE1's redox activity in in vitro electrophoretic mobility shift redox and cell-based transactivation assays, producing IC(50) values (8.5 and 7 μM) lower than those produced with E3330 (20 and 55 μM, respectively). Thus, E3330's negatively charged carboxylate is not required for redox inhibition. Collectively, our results provide additional support for a mechanism of redox inhibition involving interaction of E3330 or E3330-amide with partially unfolded APE1.
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Affiliation(s)
- Jun Zhang
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130
| | - Meihua Luo
- Section of Pediatric Hematology and Oncology, Department of Pediatrics, Indiana University School of Medicine
| | - Daniela Marasco
- Department of Pharmacy, University of Naples Federico II Via Mezzocannone, 16, 80134, Naples, Italy
| | - Derek Logsdon
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine
| | - Kaice A. LaFavers
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine
| | - Qiujia Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine
| | - April Reed
- Section of Pediatric Hematology and Oncology, Department of Pediatrics, Indiana University School of Medicine
| | - Mark R. Kelley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine
- Section of Pediatric Hematology and Oncology, Department of Pediatrics, Indiana University School of Medicine
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130
| | - Millie M. Georgiadis
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine
- Department of Chemistry and Chemical Biology, Purdue School of Science, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202
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43
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Petruccelli LA, Pettersson F, Del Rincón SV, Guilbert C, Licht JD, Miller WH. Expression of leukemia-associated fusion proteins increases sensitivity to histone deacetylase inhibitor-induced DNA damage and apoptosis. Mol Cancer Ther 2013; 12:1591-604. [PMID: 23536727 DOI: 10.1158/1535-7163.mct-12-1039] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Histone deacetylase inhibitors (HDI) show activity in a broad range of hematologic and solid malignancies, yet the percentage of patients in any given malignancy who experience a meaningful clinical response remains small. In this study, we sought to investigate HDI efficacy in acute myeloid leukemia (AML) cells expressing leukemia-associated fusion proteins (LAFP). HDIs have been shown to induce apoptosis, in part, through accumulation of DNA damage and inhibition of DNA repair. LAFPs have been correlated with a DNA repair-deficient phenotype, which may make them more sensitive to HDI-induced DNA damage. We found that expression of the LAFPs PLZF-RARα, PML-RARα, and RUNX1-ETO (AML1-ETO) increased sensitivity to DNA damage and apoptosis induced by the HDI vorinostat. The increase in apoptosis correlated with an enhanced downregulation of the prosurvival protein BCL2. Vorinostat also induced expression of the cell-cycle regulators p19(INK4D) and p21(WAF1) and triggered a G2-M cell cycle arrest to a greater extent in LAFP-expressing cells. The combination of LAFP and vorinostat further led to a greater downregulation of several base excision repair (BER) enzymes. These BER genes represent biomarker candidates for response to HDI-induced DNA damage. Notably, repair of vorinostat-induced DNA double-strand breaks was found to be impaired in PLZF-RARα-expressing cells, suggesting a mechanism by which LAFP expression and HDI treatment cooperate to cause an accumulation of damaged DNA. These data support the continued study of HDI-based treatment regimens in LAFP-positive AMLs.
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Affiliation(s)
- Luca A Petruccelli
- Lady Davis Institute for Medical Research, Segal Cancer Center, Jewish General Hospital, McGill University, Montreal, Quebec, Canada
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44
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Mudd SR, Holich KD, Voorbach MJ, Cole TB, Reuter DR, Tapang P, Bukofzer G, Chakravartty A, Donawho CK, Palma JP, Fox GB, Day M, Luo Y. Pharmacodynamic evaluation of irinotecan therapy by FDG and FLT PET/CT imaging in a colorectal cancer xenograft model. Mol Imaging Biol 2013; 14:617-24. [PMID: 22167582 DOI: 10.1007/s11307-011-0529-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
PURPOSE Longitudinal changes of 3'-[(18) F]fluoro-3'-deoxythymidine (FLT) and 2-deoxy-2-[(18) F]fluoro-D-glucose (FDG) in response to irinotecan therapy in an animal model of colorectal cancer were compared. PROCEDURES SCID/CB-17 mice with HCT116 tumors were treated with 50 mg/kg irinotecan by intraperitoneal injection weekly for 3 weeks. FLT and FDG-positron emission tomography (PET) were performed at baseline, the day after each treatment, and 5 days after the first treatment. Proliferation and apoptosis were evaluated by immunohistochemistry (IHC) after day 15 of imaging. RESULTS Irinotecan treatment resulted in a suppression of tumor growth. Tumor FLT uptake was decreased the day after each treatment but to a lesser extent 5 days after the first treatment. FDG uptake increased the day after each treatment with a continuous increase throughout the experiment. IHC analysis of phospho-H3 and Ki67 confirmed FLT-PET results, indicating a decrease in proliferation the day after the final irinotecan treatment. Increased apoptosis monitored by caspase-3 was observed after day 15 with irinotecan treatment. CONCLUSIONS FLT-PET may be a better method than FDG-PET for assessing treatment response to irinotecan. Changes in imaging occur before changes in tumor volume.
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Affiliation(s)
- Sarah R Mudd
- Translational Imaging and Biochemical Biomarkers, Advanced Technology, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, IL, USA.
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45
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Ruiz FM, Francis SM, Tintoré M, Ferreira R, Gil-Redondo R, Morreale A, Ortiz ÁR, Eritja R, Fàbrega C. Receptor-based virtual screening and biological characterization of human apurinic/apyrimidinic endonuclease (Ape1) inhibitors. ChemMedChem 2012; 7:2168-78. [PMID: 23109358 DOI: 10.1002/cmdc.201200372] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 09/26/2012] [Indexed: 12/25/2022]
Abstract
The endonucleolytic activity of human apurinic/apyrimidinic endonuclease (AP endo, Ape1) is a major factor in maintaining the integrity of the genome. Conversely, as an undesired effect, Ape1 overexpression has been linked to resistance to radio- and chemotherapeutic treatments in several human tumors. Inhibition of Ape1 using siRNA or the expression of a dominant negative form of the protein has been shown to sensitize cells to DNA-damaging agents, including various chemotherapeutic agents. Therefore, inhibition of the enzymatic activity of Ape1 might result in a potent antitumor therapy. A number of small molecules have been described as Ape1 inhibitors; however, those compounds are in the early stages of development. Herein we report the identification of new compounds as potential Ape1 inhibitors through a docking-based virtual screening technique. Some of the compounds identified have in vitro activities in the low-to-medium micromolar range. Interaction of these compounds with the Ape1 protein was observed by mass spectrometry. These molecules also potentiate the cytotoxicity of the chemotherapeutic agent methyl methanesulfonate in fibrosarcoma cells. This study demonstrates the power of docking and virtual screening techniques as initial steps in the design of new drugs, and opens the door to the development of a new generation of Ape1 inhibitors.
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Cardoso AA, Jiang Y, Luo M, Reed AM, Shahda S, He Y, Maitra A, Kelley MR, Fishel ML. APE1/Ref-1 regulates STAT3 transcriptional activity and APE1/Ref-1-STAT3 dual-targeting effectively inhibits pancreatic cancer cell survival. PLoS One 2012; 7:e47462. [PMID: 23094050 PMCID: PMC3477158 DOI: 10.1371/journal.pone.0047462] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 09/17/2012] [Indexed: 12/21/2022] Open
Abstract
Pancreatic cancer is a largely incurable disease, and increasing evidence supports strategies targeting multiple molecular mediators of critical functions of pancreatic ductal adenocarcinoma cells. Intracellular redox state modulates the activity of various signal transduction pathways and biological processes, including cell survival, drug resistance and responsiveness to microenvironmental factors. Recently, it has been shown that the transcription factor STAT3 is under redox control, but the mechanisms involved in its regulation are unknown. Here, we demonstrate for the first time that STAT3 DNA binding and transcriptional activity is directly regulated by the redox function of the APE1/Ref-1 endonuclease, using overexpression and redox-specific mutational strategies, and gene knockdown. Also, pharmacological blockade of APE1/Ref-1 by the redox-selective inhibitor E3330 abrogates STAT3 DNA binding. Since APE1/Ref-1 also exerts redox control on other cancer-associated transcription factors, we assessed the impact of dual-targeting of STAT3 signaling and APE1/Ref-1 redox on pancreatic cancer cell functions. We observed that disruption of APE1/Ref-1 redox activity synergizes with STAT3 blockade to potently inhibit the proliferation and viability of human PDAC cells. Mechanistically, we show that STAT3–APE1/Ref-1 dual targeting promotes marked tumor cell apoptosis, with engagement of caspase-3 signaling, which are significantly increased in comparison to the effects triggered by single target blockade. Also, we show that STAT3–APE1/Ref-1 dual blockade results in significant inhibition of tumor cell migration. Overall, this work demonstrates that the transcriptional activity of STAT3 is directly regulated by the redox function of APE1/Ref-1, and that concurrent blockade of STAT3 and APE1/Ref-1 redox synergize effectively inhibit critical PDAC cell functions.
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Affiliation(s)
- Angelo A. Cardoso
- Division of Hematology/Oncology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Yanlin Jiang
- Section of Hematology/Oncology, Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indianapolis, Indiana, United States of America
| | - Meihua Luo
- Section of Hematology/Oncology, Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indianapolis, Indiana, United States of America
| | - April M. Reed
- Section of Hematology/Oncology, Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indianapolis, Indiana, United States of America
| | - Safi Shahda
- Division of Hematology/Oncology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Ying He
- Section of Hematology/Oncology, Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indianapolis, Indiana, United States of America
| | - Anirban Maitra
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Mark R. Kelley
- Section of Hematology/Oncology, Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indianapolis, Indiana, United States of America
- Department of Pharmacology and Toxicology, Indiana University of School of Medicine, Indianapolis, Indiana, United States of America
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Melissa L. Fishel
- Section of Hematology/Oncology, Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indianapolis, Indiana, United States of America
- Department of Pharmacology and Toxicology, Indiana University of School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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47
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Aiello F, Shabaik Y, Esqueda A, Sanchez TW, Grande F, Garofalo A, Neamati N. Design and synthesis of 3-carbamoylbenzoic acid derivatives as inhibitors of human apurinic/apyrimidinic endonuclease 1 (APE1). ChemMedChem 2012; 7:1825-39. [PMID: 22952012 DOI: 10.1002/cmdc.201200334] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Indexed: 11/09/2022]
Abstract
Apurinic/apyrimidinic (AP) endonuclease 1 (APE1) is a multifaceted protein with an essential role in the base excision repair (BER) pathway. Its implication in tumor development, progression, and resistance has been confirmed in multiple cancers, making it a viable target for intensive investigation. In this work, we designed and synthesized different classes of small-molecule inhibitors of the catalytic endonuclease function of APE1 that contain a 3-carbamoylbenzoic acid scaffold. Further structural modifications were made with the aim of increasing the activity and cytotoxicity of these inhibitors. Several of our compounds were shown to inhibit the catalytic endonuclease function of APE1 with potencies in the low-micromolar range in vitro, and therefore represent novel classes of APE1 inhibitors worthy of further development.
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Affiliation(s)
- Francesca Aiello
- Dipartimento di Scienze Farmaceutiche, Università della Calabria, 87036 Arcavacata di Rende, CS, Italy.
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48
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Kelley MR, Georgiadis MM, Fishel ML. APE1/Ref-1 role in redox signaling: translational applications of targeting the redox function of the DNA repair/redox protein APE1/Ref-1. Curr Mol Pharmacol 2012; 5:36-53. [PMID: 22122463 DOI: 10.2174/1874467211205010036] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 08/18/2010] [Accepted: 08/25/2010] [Indexed: 12/22/2022]
Abstract
The heterogeneity of most cancers diminishes the treatment effectiveness of many cancer-killing regimens. Thus, treatments that hold the most promise are ones that block multiple signaling pathways essential to cancer survival. One of the most promising proteins in that regard is APE1, whose reduction-oxidation activity influences multiple cancer survival mechanisms, including growth, proliferation, metastasis, angiogenesis, and stress responses. With the continued research using APE1 redox specific inhibitors alone or coupled with developing APE1 DNA repair inhibitors it will now be possible to further delineate the role of APE1 redox, repair and protein-protein interactions. Previously, use of siRNA or over expression approaches, while valuable, do not give a clear picture of the two major functions of APE1 since both techniques severely alter the cellular milieu. Additionally, use of the redox-specific APE1 inhibitor, APX3330, now makes it possible to study how inhibition of APE1's redox signaling can affect multiple tumor pathways and can potentiate the effectiveness of existing cancer regimens. Because APE1 is an upstream effector of VEGF, as well as other molecules that relate to angiogenesis and the tumor microenvironment, it is also being studied as a possible treatment for agerelated macular degeneration and diabetic retinopathy. This paper reviews all of APE1's functions, while heavily focusing on its redox activities. It also discusses APE1's altered expression in many cancers and the therapeutic potential of selective inhibition of redox regulation, which is the subject of intense preclinical studies.
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Affiliation(s)
- Mark R Kelley
- Department of Pediatrics (Section of Hematology/Oncology), Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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49
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Luo M, Zhang J, He H, Su D, Chen Q, Gross ML, Kelley MR, Georgiadis MM. Characterization of the redox activity and disulfide bond formation in apurinic/apyrimidinic endonuclease. Biochemistry 2012; 51:695-705. [PMID: 22148505 PMCID: PMC3293223 DOI: 10.1021/bi201034z] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Apurinic/apyrimidinic endonuclease (APE1) is an unusual nuclear redox factor in which the redox-active cysteines identified to date, C65 and C93, are surface inaccessible residues whose activities may be influenced by partial unfolding of APE1. To assess the role of the five remaining cysteines in APE1's redox activity, double-cysteine mutants were analyzed, excluding C65A, which is redox-inactive as a single mutant. C93A/C99A APE1 was found to be redox-inactive, whereas other double-cysteine mutants retained the same redox activity as that observed for C93A APE1. To determine whether these three cysteines, C65, C93, and C99, were sufficient for redox activity, all other cysteines were substituted with alanine, and this protein was shown to be fully redox-active. Mutants with impaired redox activity failed to stimulate cell proliferation, establishing an important role for APE1's redox activity in cell growth. Disulfide bond formation upon oxidation of APE1 was analyzed by proteolysis of the protein followed by mass spectrometry analysis. Within 5 min of exposure to hydrogen peroxide, a single disulfide bond formed between C65 and C138 followed by the formation of three additional disulfide bonds within 15 min; 10 total disulfide bonds formed within 1 h. A single mixed-disulfide bond involving C99 of APE1 was observed for the reaction of oxidized APE1 with thioredoxin (TRX). Disulfide-bonded APE1 or APE1-TRX species were further characterized by size exclusion chromatography and found to form large complexes. Taken together, our data suggest that APE1 is a unique redox factor with properties distinct from those of other redox factors.
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Affiliation(s)
- Meihua Luo
- Section of Pediatric Hematology and Oncology, Department of Pediatrics, Washington University in St. Louis, St. Louis, Missouri
| | - Jun Zhang
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri
| | - Hongzhen He
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Washington University in St. Louis, St. Louis, Missouri
| | - Dian Su
- Department of Chemistry and Chemical Biology, Purdue School of Science, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202
| | - Qiujia Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Washington University in St. Louis, St. Louis, Missouri
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri
| | - Mark R. Kelley
- Section of Pediatric Hematology and Oncology, Department of Pediatrics, Washington University in St. Louis, St. Louis, Missouri
| | - Millie M. Georgiadis
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Washington University in St. Louis, St. Louis, Missouri
- Department of Chemistry and Chemical Biology, Purdue School of Science, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202
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50
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Kim YJ, Kim D, Illuzzi JL, Delaplane S, Su D, Bernier M, Gross ML, Georgiadis MM, Wilson DM. S-glutathionylation of cysteine 99 in the APE1 protein impairs abasic endonuclease activity. J Mol Biol 2011; 414:313-26. [PMID: 22024594 DOI: 10.1016/j.jmb.2011.10.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 10/03/2011] [Accepted: 10/12/2011] [Indexed: 12/24/2022]
Abstract
Human apurinic/apyrimidinic (AP) endonuclease 1 (APE1) is a central participant in the base excision repair pathway, exhibiting AP endonuclease activity that incises the DNA backbone 5' to an abasic site. Besides its prominent role as a DNA repair enzyme, APE1 was separately identified as a protein called redox effector factor 1, which is able to enhance the DNA binding activity of several transcription factors through a thiol-exchange-based reduction-oxidation mechanism. In the present study, we found that human APE1 is S-glutathionylated under conditions of oxidative stress both in the presence of glutathione in vitro and in cells. S-glutathionylated APE1 displayed significantly reduced AP endonuclease activity on abasic-site-containing oligonucleotide substrates, a result stemming from impaired DNA binding capacity. The combination of site-directed mutagenesis, biochemical assays, and mass spectrometric analysis identified Cys99 in human APE1 as the critical residue for the S-glutathionylation that leads to reduced AP endonuclease activity. This modification is reversible by reducing agents, which restore APE1 incision function. Our studies describe a novel posttranslational modification of APE1 that regulates the DNA repair function of the protein.
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Affiliation(s)
- Yun-Jeong Kim
- Laboratory of Molecular Gerontology, Biomedical Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
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