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Li YH, Zhao ML, Zhang P, Yang X, Yuan R, Zhuo Y. Target-Driven Annular DNA Walker Coupled with Electrochemiluminescent Silicon Quantum Dots for APE1 Bioanalysis. Anal Chem 2023; 95:18629-18634. [PMID: 38057277 DOI: 10.1021/acs.analchem.3c04747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
Functional DNA walkers with substantial nanostructures have been extensively investigated; however, their stability still faces challenges when exposed to diverse nuclease in clinical biological samples, resulting in the unreliability of actual assessment. This work proposed a target-driven annular DNA walker with enhanced stability enabling the sensitive and reliable response to different concentrations of apurinic/apyrimidinic endonuclease 1 (APE1), by preparing silicon quantum dots (SiQDs) as electrochemiluminescence (ECL) emitters. Specifically, the SiQDs showed significant strong and stable ECL signals by purifying the microenvironment of SiQDs through the dialysis removal of the gel-like layers surrounding the SiQDs. The relative standard deviation (RSD) of their ECL signal had been improved 16.59 times under consecutive scanning compared to that of SiQDs without dialysis, demonstrating a significant improvement in ECL stability. Subsequently, in the presence of APE1, the designed annular DNA walker was activated to move along the numerous quenching probes within the continuous cross-based DNA orbits, which were immobilized to the SiQD-modified electrode, providing ECL readout signals. The linear range of this ECL biosensor was 1.0 × 10-13 U·μL-1 to 1.0 × 10-7 U·μL-1, and the limit of detection (LOD) was as low as 1.766 × 10-14 U·μL-1. This work provides a novel structure of a DNA walker with nuclease resistance for clinical sample detection and designs a new strategy for synthesizing SiQDs with favorable ECL performance, tremendously expanding the ECL application of SiQDs.
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Affiliation(s)
- Ying-Huan Li
- Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
| | - Mei-Ling Zhao
- Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
| | - Pu Zhang
- Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
| | - Xia Yang
- Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
| | - Ruo Yuan
- Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
| | - Ying Zhuo
- Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
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2
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Zhang Y, Liang L, Li Z, Huang Y, Jiang M, Zou B, Xu Y. Polyadenosine diphosphate-ribose polymerase inhibitors: advances, implications, and challenges in tumor radiotherapy sensitization. Front Oncol 2023; 13:1295579. [PMID: 38111536 PMCID: PMC10726039 DOI: 10.3389/fonc.2023.1295579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Accepted: 11/22/2023] [Indexed: 12/20/2023] Open
Abstract
Polyadenosine diphosphate-ribose polymerase (PARP) is a key modifying enzyme in cells, which participates in single-strand break repair and indirectly affects double-strand break repair. PARP inhibitors have shown great potential in oncotherapy by exploiting DNA damage repair pathways, and several small molecule PARP inhibitors have been approved by the U.S. Food and Drug Administration for treating various tumor types. PARP inhibitors not only have significant antitumor effects but also have some synergistic effects when combined with radiotherapy; therefore they have potential as radiation sensitizers. Here, we reviewed the advances and implications of PARP inhibitors in tumor radiotherapy sensitization. First, we summarized the multiple functions of PARP and the mechanisms by which its inhibitors exert antitumor effects. Next, we discuss the immunomodulatory effects of PARP and its inhibitors in tumors. Then, we described the theoretical basis of using PARP inhibitors in combination with radiotherapy and outlined their importance in oncological radiotherapy. Finally, we reviewed the current challenges in this field and elaborated on the future applications of PARP inhibitors as radiation sensitizers. A comprehensive understanding of the mechanism, optimal dosing, long-term safety, and identification of responsive biomarkers remain key challenges to integrating PARP inhibition into the radiotherapy management of cancer patients. Therefore, extensive research in these areas would facilitate the development of precision radiotherapy using PARP inhibitors to improve patient outcomes.
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Affiliation(s)
- Yi Zhang
- Department of Radiation Oncology, Division of Thoracic Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Lijie Liang
- Division of Head & Neck Tumor Multimodality Treatment, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Zheng Li
- Department of Radiation Oncology, Division of Thoracic Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Ying Huang
- College of Management, Sichuan Agricultural University, Chengdu, China
| | - Ming Jiang
- Division of Head & Neck Tumor Multimodality Treatment, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Bingwen Zou
- Department of Radiation Oncology, Division of Thoracic Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Yong Xu
- Department of Radiation Oncology, Division of Thoracic Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
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3
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Tornyi I, Árkosy P, Horváth I, Furka A. A new perspective on the proper timing of radiotherapy during CDK4/6 inhibitor therapy in patients with "bone-only" metastatic breast cancer. Pathol Oncol Res 2023; 29:1611369. [PMID: 37886029 PMCID: PMC10598277 DOI: 10.3389/pore.2023.1611369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/25/2023] [Indexed: 10/28/2023]
Abstract
The vast majority of hormone positive and HER2 negative advanced breast cancers can be controlled well by endocrine therapy combined with the groundbreaking use of CDK4/6 inhibitors in the metastatic first-line setting. Approximately 50%-60% of these patients have "bone-only" metastatic disease. In oligometastatic cases or if a certain number of uncontrolled lesions develop during the aforementioned therapy, ablative radiotherapy can be delivered or, in symptomatic cases, urgent irradiation is needed with palliative intent. To achieve the most effective results, parallel with good quality of life, the timing of radiotherapy must be determined precisely, taking into account that different cell cycles are involved during different treatment modalities; therefore, optimization of treatment schedules ensures longer and safer post-progression overall survival. The key question is whether the two treatment modalities are safe concurrently or whether they should be administered separately, and if so, what is the optimal sequence and why? This manuscript aims to answer this important question, with a focus on quality of life. Existing publications focus on safety and toxicity profiles, and efficacy is detailed only tangentially and minimally.
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Affiliation(s)
- Ilona Tornyi
- Department of Pulmonology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Peter Árkosy
- Department of Oncology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Ildikó Horváth
- Department of Pulmonology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Andrea Furka
- Department of Oncology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Department of Clinical Radiology, Faculty of Health Care, Institute of Practical Methodology and Diagnostics, University of Miskolc, Miskolc, Hungary
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4
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Malfatti MC, Bellina A, Antoniali G, Tell G. Revisiting Two Decades of Research Focused on Targeting APE1 for Cancer Therapy: The Pros and Cons. Cells 2023; 12:1895. [PMID: 37508559 PMCID: PMC10378182 DOI: 10.3390/cells12141895] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/06/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
APE1 is an essential endodeoxyribonuclease of the base excision repair pathway that maintains genome stability. It was identified as a pivotal factor favoring tumor progression and chemoresistance through the control of gene expression by a redox-based mechanism. APE1 is overexpressed and serum-secreted in different cancers, representing a prognostic and predictive factor and a promising non-invasive biomarker. Strategies directly targeting APE1 functions led to the identification of inhibitors showing potential therapeutic value, some of which are currently in clinical trials. Interestingly, evidence indicates novel roles of APE1 in RNA metabolism that are still not fully understood, including its activity in processing damaged RNA in chemoresistant phenotypes, regulating onco-miRNA maturation, and oxidized RNA decay. Recent data point out a control role for APE1 in the expression and sorting of onco-miRNAs within secreted extracellular vesicles. This review is focused on giving a portrait of the pros and cons of the last two decades of research aiming at the identification of inhibitors of the redox or DNA-repair functions of APE1 for the definition of novel targeted therapies for cancer. We will discuss the new perspectives in cancer therapy emerging from the unexpected finding of the APE1 role in miRNA processing for personalized therapy.
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Affiliation(s)
- Matilde Clarissa Malfatti
- Laboratory of Molecular Biology and DNA Repair, Department of Medicine, University of Udine, 33100 Udine, Italy
| | - Alessia Bellina
- Laboratory of Molecular Biology and DNA Repair, Department of Medicine, University of Udine, 33100 Udine, Italy
| | - Giulia Antoniali
- Laboratory of Molecular Biology and DNA Repair, Department of Medicine, University of Udine, 33100 Udine, Italy
| | - Gianluca Tell
- Laboratory of Molecular Biology and DNA Repair, Department of Medicine, University of Udine, 33100 Udine, Italy
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5
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Bulygin AA, Syryamina VN, Kuznetsova AA, Novopashina DS, Dzuba SA, Kuznetsov NA. Inner Amino Acid Contacts Are Key Factors of Multistage Structural Rearrangements of DNA and Affect Substrate Specificity of Apurinic/Apyrimidinic Endonuclease APE1. Int J Mol Sci 2023; 24:11474. [PMID: 37511233 PMCID: PMC10380840 DOI: 10.3390/ijms241411474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/10/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
Apurinic/apyrimidinic endonuclease 1 (APE1) is one of the most important enzymes in base excision repair. Studies on this enzyme have been conducted for a long time, but some aspects of its activity remain poorly understood. One such question concerns the mechanism of damaged-nucleotide recognition by the enzyme, and the answer could shed light on substrate specificity control in all enzymes of this class. In the present study, by pulsed electron-electron double resonance (DEER, also known as PELDOR) spectroscopy and pre-steady-state kinetic analysis along with wild-type (WT) APE1 from Danio rerio (zAPE1) or three mutants (carrying substitution N253G, A254G, or E260A), we aimed to elucidate the molecular events in the process of damage recognition. The data revealed that the zAPE1 mutant E260A has much higher activity toward DNA substrates containing 5,6-dihydro-2'-deoxyuridine (DHU), 2'-deoxyuridine (dU), alpha-2'-deoxyadenosine (αA), or 1,N6-ethenoadenosine (εA). Examination of conformational changes in DNA clearly revealed multistep DNA rearrangements during the formation of the catalytic complex. These structural rearrangements of DNA are directly associated with the capacity of damaged DNA for enzyme-induced bending and unwinding, which are required for eversion of the damaged nucleotide from the DNA duplex and for its placement into the active site of the enzyme. Taken together, the results experimentally prove the factors that control substrate specificity of the AP endonuclease zAPE1.
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Affiliation(s)
- Anatoly A Bulygin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences (SB RAS), Novosibirsk 630090, Russia
| | - Victoria N Syryamina
- Institute of Chemical Kinetics and Combustion, Siberian Branch of Russian Academy of Sciences (SB RAS), Novosibirsk 630090, Russia
| | - Aleksandra A Kuznetsova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences (SB RAS), Novosibirsk 630090, Russia
| | - Darya S Novopashina
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences (SB RAS), Novosibirsk 630090, Russia
| | - Sergei A Dzuba
- Institute of Chemical Kinetics and Combustion, Siberian Branch of Russian Academy of Sciences (SB RAS), Novosibirsk 630090, Russia
| | - Nikita A Kuznetsov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences (SB RAS), Novosibirsk 630090, Russia
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
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Schrader CE, Williams T, Pechhold K, Linehan EK, Tsuchimoto D, Nakabeppu Y. APE2 Promotes AID-Dependent Somatic Hypermutation in Primary B Cell Cultures That Is Suppressed by APE1. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 210:1804-1814. [PMID: 37074207 PMCID: PMC10234595 DOI: 10.4049/jimmunol.2100946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 03/29/2023] [Indexed: 04/20/2023]
Abstract
Somatic hypermutation (SHM) is necessary for Ab diversification and involves error-prone DNA repair of activation-induced cytidine deaminase-induced lesions in germinal center (GC) B cells but can also cause genomic instability. GC B cells express low levels of the DNA repair protein apurinic/apyrimidinic (AP) endonuclease (APE)1 and high levels of its homolog APE2. Reduced SHM in APE2-deficient mice suggests that APE2 promotes SHM, but these GC B cells also exhibit reduced proliferation that could impact mutation frequency. In this study, we test the hypothesis that APE2 promotes and APE1 suppresses SHM. We show how APE1/APE2 expression changes in primary murine spleen B cells during activation, impacting both SHM and class-switch recombination (CSR). High levels of both APE1 and APE2 early after activation promote CSR. However, after 2 d, APE1 levels decrease steadily with each cell division, even with repeated stimulation, whereas APE2 levels increase with each stimulation. When GC-level APE1/APE2 expression was engineered by reducing APE1 genetically (apex1+/-) and overexpressing APE2, bona fide activation-induced cytidine deaminase-dependent VDJH4 intron SHM became detectable in primary B cell cultures. The C terminus of APE2 that interacts with proliferating cell nuclear Ag promotes SHM and CSR, although its ATR-Chk1-interacting Zf-GRF domain is not required. However, APE2 does not increase mutations unless APE1 is reduced. Although APE1 promotes CSR, it suppresses SHM, suggesting that downregulation of APE1 in the GC is required for SHM. Genome-wide expression data compare GC and cultured B cells and new models depict how APE1 and APE2 expression and protein interactions change during B cell activation and affect the balance between accurate and error-prone repair during CSR and SHM.
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Affiliation(s)
- Carol E. Schrader
- Department of Microbiology and Physiological Systems, Program in Immunology and Microbiology, UMassChan Medical School, Worcester, MA 01655
| | - Travis Williams
- Department of Microbiology and Physiological Systems, Program in Immunology and Microbiology, UMassChan Medical School, Worcester, MA 01655
| | - Klaus Pechhold
- Department of Microbiology and Physiological Systems, Program in Immunology and Microbiology, UMassChan Medical School, Worcester, MA 01655
| | - Erin K. Linehan
- Department of Microbiology and Physiological Systems, Program in Immunology and Microbiology, UMassChan Medical School, Worcester, MA 01655
| | - Daisuke Tsuchimoto
- Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yusaku Nakabeppu
- Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan
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7
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Lin Y, Li J, Zhao H, McMahon A, McGhee K, Yan S. APE1 recruits ATRIP to ssDNA in an RPA-dependent and -independent manner to promote the ATR DNA damage response. eLife 2023; 12:82324. [PMID: 37216274 DOI: 10.7554/elife.82324] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 05/08/2023] [Indexed: 05/24/2023] Open
Abstract
Cells have evolved the DNA damage response (DDR) pathways in response to DNA replication stress or DNA damage. In the ATR-Chk1 DDR pathway, it has been proposed that ATR is recruited to RPA-coated single-stranded DNA (ssDNA) by direct ATRIP-RPA interaction. However, it remains elusive how ATRIP is recruited to ssDNA in an RPA-independent manner. Here, we provide evidence that APE1 directly associates ssDNA to recruit ATRIP onto ssDNA in an RPA-independent fashion. The N-terminal motif within APE1 is required and sufficient for the APE1-ATRIP interaction in vitro and the distinct APE1-ATRIP interaction is required for ATRIP recruitment to ssDNA and the ATR-Chk1 DDR pathway activation in Xenopus egg extracts. In addition, APE1 directly associates with RPA70 and RPA32 via two distinct motifs. Taken together, our evidence suggests that APE1 recruits ATRIP onto ssDNA in an RPA-dependent and -independent manner in the ATR DDR pathway.
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Affiliation(s)
- Yunfeng Lin
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, United States
| | - Jia Li
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, United States
| | - Haichao Zhao
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, United States
| | - Anne McMahon
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, United States
| | - Kelly McGhee
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, United States
| | - Shan Yan
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, United States
- School of Data Science, University of North Carolina at Charlotte, Charlotte, United States
- Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, United States
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Xu Y, Nowsheen S, Deng M. DNA Repair Deficiency Regulates Immunity Response in Cancers: Molecular Mechanism and Approaches for Combining Immunotherapy. Cancers (Basel) 2023; 15:cancers15051619. [PMID: 36900418 PMCID: PMC10000854 DOI: 10.3390/cancers15051619] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/26/2023] [Accepted: 03/04/2023] [Indexed: 03/09/2023] Open
Abstract
Defects in DNA repair pathways can lead to genomic instability in multiple tumor types, which contributes to tumor immunogenicity. Inhibition of DNA damage response (DDR) has been reported to increase tumor susceptibility to anticancer immunotherapy. However, the interplay between DDR and the immune signaling pathways remains unclear. In this review, we will discuss how a deficiency in DDR affects anti-tumor immunity, highlighting the cGAS-STING axis as an important link. We will also review the clinical trials that combine DDR inhibition and immune-oncology treatments. A better understanding of these pathways will help exploit cancer immunotherapy and DDR pathways to improve treatment outcomes for various cancers.
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Affiliation(s)
- Yi Xu
- State Key Laboratory of Molecular Oncology and Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
| | - Somaira Nowsheen
- Department of Dermatology, University of California San Diego, San Diego, CA 92122, USA
- Correspondence: (S.N.); (M.D.)
| | - Min Deng
- State Key Laboratory of Molecular Oncology and Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
- Correspondence: (S.N.); (M.D.)
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9
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McMahon A, Zhao J, Yan S. APE2: catalytic function and synthetic lethality draw attention as a cancer therapy target. NAR Cancer 2023; 5:zcad006. [PMID: 36755963 PMCID: PMC9900424 DOI: 10.1093/narcan/zcad006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/17/2023] [Accepted: 01/20/2023] [Indexed: 02/08/2023] Open
Abstract
AP endonuclease 2 (APE2, APEX2 or APN2) is an emerging critical protein involved in genome and epigenome integrity. Whereas its catalytic function as a nuclease in DNA repair is widely accepted, recent studies have elucidated the function and mechanism of APE2 in the immune response and DNA damage response. Several genome-wide screens have identified APE2 as a synthetic lethal target for deficiencies of BRCA1, BRCA2 or TDP1 in cancer cells. Due to its overexpression in several cancer types, APE2 is proposed as an oncogene and could serve as prognostic marker of overall survival of cancer treatment. However, it remains to be discovered whether and how APE2 catalytic function and synthetic lethality can be modulated and manipulated as a cancer therapy target. In this review, we provide a current understanding of alterations and expression of APE2 in cancer, the function of APE2 in the immune response, and mechanisms of APE2 in ATR/Chk1 DNA damage response. We also summarize the role of APE2 in DNA repair pathways in the removal of heterogenous and complexed 3'-termini and MMEJ. Finally, we provide an updated perspective on how APE2 may be targeted for cancer therapy and future directions of APE2 studies in cancer biology.
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Affiliation(s)
- Anne McMahon
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Jianjun Zhao
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Shan Yan
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
- School of Data Science, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
- Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
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10
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Role of Histone Tails and Single Strand DNA Breaks in Nucleosomal Arrest of RNA Polymerase. Int J Mol Sci 2023; 24:ijms24032295. [PMID: 36768621 PMCID: PMC9917218 DOI: 10.3390/ijms24032295] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/13/2023] [Accepted: 01/19/2023] [Indexed: 01/26/2023] Open
Abstract
Transcription through nucleosomes by RNA polymerases (RNAP) is accompanied by formation of small intranucleosomal DNA loops (i-loops). The i-loops form more efficiently in the presence of single-strand breaks or gaps in a non-template DNA strand (NT-SSBs) and induce arrest of transcribing RNAP, thus allowing detection of NT-SSBs by the enzyme. Here we examined the role of histone tails and extranucleosomal NT-SSBs in i-loop formation and arrest of RNAP during transcription of promoter-proximal region of nucleosomal DNA. NT-SSBs present in linker DNA induce arrest of RNAP +1 to +15 bp in the nucleosome, suggesting formation of the i-loops; the arrest is more efficient in the presence of the histone tails. Consistently, DNA footprinting reveals formation of an i-loop after stalling RNAP at the position +2 and backtracking to position +1. The data suggest that histone tails and NT-SSBs present in linker DNA strongly facilitate formation of the i-loops during transcription through the promoter-proximal region of nucleosomal DNA.
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11
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Kinetic Features of 3'-5'-Exonuclease Activity of Apurinic/Apyrimidinic Endonuclease Apn2 from Saccharomyces cerevisiae. Int J Mol Sci 2022; 23:ijms232214404. [PMID: 36430884 PMCID: PMC9697762 DOI: 10.3390/ijms232214404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 11/22/2022] Open
Abstract
In yeast Saccharomyces cerevisiae cells, apurinic/apyrimidinic (AP) sites are primarily repaired by base excision repair. Base excision repair is initiated by one of two AP endonucleases: Apn1 or Apn2. AP endonucleases catalyze hydrolytic cleavage of the phosphodiester backbone on the 5' side of an AP site, thereby forming a single-strand break containing 3'-OH and 5'-dRP ends. In addition, Apn2 has 3'-phosphodiesterase activity (removing 3'-blocking groups) and 3' → 5' exonuclease activity (both much stronger than its AP endonuclease activity). Nonetheless, the role of the 3'-5'-exonuclease activity of Apn2 remains unclear and presumably is involved in the repair of damage containing single-strand breaks. In this work, by separating reaction products in a polyacrylamide gel and by a stopped-flow assay, we performed a kinetic analysis of the interaction of Apn2 with various model DNA substrates containing a 5' overhang. The results allowed us to propose a mechanism for the cleaving off of nucleotides and to determine the rate of the catalytic stage of the process. It was found that dissociation of a reaction product from the enzyme active site is not a rate-limiting step in the enzymatic reaction. We determined an influence of the nature of the 3'-terminal nucleotide that can be cleaved off on the course of the enzymatic reaction. Finally, it was found that the efficiency of the enzymatic reaction is context-specific.
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12
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Li J, Zhao H, McMahon A, Yan S. APE1 assembles biomolecular condensates to promote the ATR-Chk1 DNA damage response in nucleolus. Nucleic Acids Res 2022; 50:10503-10525. [PMID: 36200829 PMCID: PMC9561277 DOI: 10.1093/nar/gkac853] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 09/14/2022] [Accepted: 10/03/2022] [Indexed: 11/13/2022] Open
Abstract
Multifunctional protein APE1/APEX1/HAP1/Ref-1 (designated as APE1) plays important roles in nuclease-mediated DNA repair and redox regulation in transcription. However, it is unclear how APE1 regulates the DNA damage response (DDR) pathways. Here we show that siRNA-mediated APE1-knockdown or APE1 inhibitor treatment attenuates the ATR–Chk1 DDR under stress conditions in multiple immortalized cell lines. Congruently, APE1 overexpression (APE1-OE) activates the ATR DDR under unperturbed conditions, which is independent of APE1 nuclease and redox functions. Structural and functional analysis reveals a direct requirement of the extreme N-terminal motif within APE1 in the assembly of distinct biomolecular condensates in vitro and DNA/RNA-independent activation of the ATR DDR. Overexpressed APE1 co-localizes with nucleolar NPM1 and assembles biomolecular condensates in nucleoli in cancer but not non-malignant cells, which recruits ATR and activator molecules TopBP1 and ETAA1. APE1 protein can directly activate ATR to phosphorylate its substrate Chk1 in in vitro kinase assays. W119R mutant of APE1 is deficient in nucleolar condensation, and is incapable of activating nucleolar ATR DDR in cells and ATR kinase in vitro. APE1-OE-induced nucleolar ATR DDR activation leads to compromised ribosomal RNA transcription and reduced cell viability. Taken together, we propose distinct mechanisms by which APE1 regulates ATR DDR pathways.
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Affiliation(s)
- Jia Li
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Haichao Zhao
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Anne McMahon
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Shan Yan
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA.,School of Data Science, University of North Carolina at Charlotte, Charlotte, NC 28223, USA.,Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
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13
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Xue Z, Demple B. Knockout and Inhibition of Ape1: Roles of Ape1 in Base Excision DNA Repair and Modulation of Gene Expression. Antioxidants (Basel) 2022; 11:antiox11091817. [PMID: 36139891 PMCID: PMC9495735 DOI: 10.3390/antiox11091817] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/31/2022] [Accepted: 09/07/2022] [Indexed: 11/21/2022] Open
Abstract
Apurinic/apyrimidinic endonuclease 1/redox effector-1 (Ape1/Ref-1) is the major apurinic/apyrimidinic (AP) endonuclease in mammalian cells. It functions mainly in the base excision repair pathway to create a suitable substrate for DNA polymerases. Human Ape1 protein can activate some transcription factors to varying degrees, dependent on its N-terminal, unstructured domain, and some of the cysteines within it, apparently via a redox mechanism in some cases. Many cancer studies also suggest that Ape1 has potential for prognosis in terms of the protein level or intracellular localization. While homozygous disruption of the Ape1 structural gene APEX1 in mice causes embryonic lethality, and most studies in cell culture indicate that the expression of Ape1 is essential, some recent studies reported the isolation of viable APEX1 knockout cells with only mild phenotypes. It has not been established by what mechanism the Ape1-null cell lines cope with the endogenous DNA damage that the enzyme normally handles. We review the enzymatic and other activities of Ape1 and the recent studies of the properties of the APEX1 knockout lines. The APEX1 deletions in CH12F3 and HEK293 FT provide an opportunity to test for possible off-target effects of Ape1 inhibition. For this work, we tested the Ape1 endonuclease inhibitor Compound 3 and the redox inhibitor APX2009. Our results confirmed that both APEX1 knockout cell lines are modestly more sensitive to killing by an alkylating agent than their Ape1-proficient cells. Surprisingly, the knockout lines showed equal sensitivity to direct killing by either inhibitor, despite the lack of the target protein. Moreover, the CH12F3 APEX1 knockout was even more sensitive to Compound 3 than its APEX1+ counterpart. Thus, it appears that both Compound 3 and APX2009 have off-target effects. In cases where this issue may be important, it is advisable that more specific endpoints than cell survival be tested for establishing mechanism.
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Affiliation(s)
- Zhouyiyuan Xue
- Department of Pharmacological Sciences, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794-8651, USA
- Molecular and Cellular Biochemistry Program, Stony Brook University, Stony Brook, NY 11794-8651, USA
| | - Bruce Demple
- Department of Pharmacological Sciences, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794-8651, USA
- Correspondence: ; Tel.: +1-(631)-444-3978
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14
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Whitaker AM, Stark WJ, Freudenthal B. Processing oxidatively damaged bases at DNA strand breaks by APE1. Nucleic Acids Res 2022; 50:9521-9533. [PMID: 36018803 PMCID: PMC9458457 DOI: 10.1093/nar/gkac695] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 07/20/2022] [Accepted: 07/31/2022] [Indexed: 01/12/2023] Open
Abstract
Reactive oxygen species attack the structure of DNA, thus altering its base-pairing properties. Consequently, oxidative stress-associated DNA lesions are a major source of the mutation load that gives rise to cancer and other diseases. Base excision repair (BER) is the pathway primarily tasked with repairing DNA base damage, with apurinic/apyrimidinic endonuclease (APE1) having both AP-endonuclease and 3' to 5' exonuclease (exo) DNA cleavage functions. The lesion 8-oxo-7,8-dihydroguanine (8-oxoG) can enter the genome as either a product of direct damage to the DNA, or through polymerase insertion at the 3'-end of a DNA strand during replication or repair. Importantly, 3'-8-oxoG impairs the ligation step of BER and therefore must be removed by the exo activity of a surrogate enzyme to prevent double stranded breaks and cell death. In the present study, we use X-ray crystallography to characterize the exo activity of APE1 on 3'-8-oxoG substrates. These structures support a unified APE1 exo mechanism that differs from its more canonical AP-endonuclease activity. In addition, through complementation of the structural data with enzyme kinetics and binding studies employing both wild-type and rationally designed APE1 mutants, we were able to identify and characterize unique protein: DNA contacts that specifically mediate 8-oxoG removal by APE1.
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Affiliation(s)
- Amy M Whitaker
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
- Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Wesley J Stark
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Bret D Freudenthal
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
- The University of Kansas Cancer Center, Kansas City, Kansas, USA
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15
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Caldecott KW. DNA single-strand break repair and human genetic disease. Trends Cell Biol 2022; 32:733-745. [PMID: 35643889 DOI: 10.1016/j.tcb.2022.04.010] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 04/13/2022] [Accepted: 04/22/2022] [Indexed: 12/15/2022]
Abstract
DNA single-strand breaks (SSBs) are amongst the commonest DNA lesions arising in cells, with many tens of thousands induced in each cell each day. SSBs arise not only from exposure to intracellular and environmental genotoxins but also as intermediates of normal DNA metabolic processes, such as the removal of torsional stress in DNA by topoisomerase enzymes and the epigenetic regulation of gene expression by DNA base excision repair (BER). If not rapidly detected and repaired, SSBs can result in RNA polymerase stalling, DNA replication fork collapse, and hyperactivation of the SSB sensor protein poly(ADP-ribose) polymerase 1 (PARP1). The potential impact of unrepaired SSBs is illustrated by the existence of genetic diseases in which proteins involved in SSB repair (SSBR) are mutated, and which are typified by hereditary neurodevelopmental and/or neurodegenerative disease. Here, I review our current understanding of SSBR and its impact on human neurological disease, with a focus on recent developments and concepts.
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Affiliation(s)
- Keith W Caldecott
- Genome Damage and Stability Centre, School of Life Sciences, Science Park Road, University of Sussex, Falmer, Brighton BN1 9RQ, UK.
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16
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Drevet JR, Hallak J, Nasr-Esfahani MH, Aitken RJ. Reactive Oxygen Species and Their Consequences on the Structure and Function of Mammalian Spermatozoa. Antioxid Redox Signal 2022; 37:481-500. [PMID: 34913729 DOI: 10.1089/ars.2021.0235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Significance: Among the 200 or so cell types that comprise mammals, spermatozoa have an ambiguous relationship with the reactive oxygen species (ROS) inherent in the consumption of oxygen that supports aerobic metabolism. Recent Advances: In this review, we shall see that spermatozoa need the action of ROS to reach their structural and functional maturity, but that due to intrinsic unique characteristics, they are, perhaps more than any other cell type, susceptible to oxidative damage. Recent studies have improved our knowledge of how oxidative damage affects sperm structures and functions. The focus of this review will be on how genetic and epigenetic oxidative alterations to spermatozoa can have dramatic unintended consequences in terms of both the support and the suppression of sperm function. Critical Issues: Oxidative stress can have dramatic consequences not only for the spermatozoon itself, but also, and above all, on its primary objective, which is to carry out fertilization and to ensure, in part, that the embryonic development program should lead to a healthy progeny. Future Directions: Sperm oxidative DNA damage largely affects the integrity of the paternal genetic material to such an extent that the oocyte may have difficulties in correcting it. Diagnostic and therapeutic actions should be considered more systematically, especially in men with difficulties to conceive. Research is underway to determine whether the epigenetic information carried by spermatozoa is also subject to changes mediated by pro-oxidative situations. Antioxid. Redox Signal. 37, 481-500.
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Affiliation(s)
- Joël R Drevet
- Faculty of Medicine, GReD Institute, INSERM U1103-CNRS UMR6293-Université Clermont Auvergne, Clermont-Ferrand, France
| | - Jorge Hallak
- Androscience, Science and Innovation Center in Andrology and High-Complex Clinical and Research Andrology Laboratory, São Paulo, Brazil.,Division of Urology, University of São Paulo, São Paulo, Brazil.,Men's Health Study Group, Institute for Advanced Studies, University of São Paulo, São Paulo, Brazil.,Reproductive Toxicology Unit, Department of Pathology, University of São Paulo, São Paulo, Brazil
| | - Mohammad-Hossein Nasr-Esfahani
- Department of Animal Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran.,Isfahan Fertility and Infertility Center, Isfahan, Iran
| | - Robert J Aitken
- Faculty of Science and Priority Research Center for Reproductive Sciences, The University of Newcastle, Callaghan, Australia.,Faculty of Health and Medicine, Priority Research Center for Reproductive Sciences, The University of Newcastle, Callaghan, Australia.,Hunter Medical Research Institute, New Lambton Heights, Australia
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17
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Structure of an Intranucleosomal DNA Loop That Senses DNA Damage during Transcription. Cells 2022; 11:cells11172678. [PMID: 36078089 PMCID: PMC9454427 DOI: 10.3390/cells11172678] [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: 07/29/2022] [Revised: 08/22/2022] [Accepted: 08/24/2022] [Indexed: 11/16/2022] Open
Abstract
Transcription through chromatin by RNA polymerase II (Pol II) is accompanied by the formation of small intranucleosomal DNA loops containing the enzyme (i-loops) that are involved in survival of core histones on the DNA and arrest of Pol II during the transcription of damaged DNA. However, the structures of i-loops have not been determined. Here, the structures of the intermediates formed during transcription through a nucleosome containing intact or damaged DNA were studied using biochemical approaches and electron microscopy. After RNA polymerase reaches position +24 from the nucleosomal boundary, the enzyme can backtrack to position +20, where DNA behind the enzyme recoils on the surface of the histone octamer, forming an i-loop that locks Pol II in the arrested state. Since the i-loop is formed more efficiently in the presence of SSBs positioned behind the transcribing enzyme, the loop could play a role in the transcription-coupled repair of DNA damage hidden in the chromatin structure.
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18
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Manils J, Marruecos L, Soler C. Exonucleases: Degrading DNA to Deal with Genome Damage, Cell Death, Inflammation and Cancer. Cells 2022; 11:cells11142157. [PMID: 35883600 PMCID: PMC9316158 DOI: 10.3390/cells11142157] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/30/2022] [Accepted: 07/07/2022] [Indexed: 01/27/2023] Open
Abstract
Although DNA degradation might seem an unwanted event, it is essential in many cellular processes that are key to maintaining genomic stability and cell and organism homeostasis. The capacity to cut out nucleotides one at a time from the end of a DNA chain is present in enzymes called exonucleases. Exonuclease activity might come from enzymes with multiple other functions or specialized enzymes only dedicated to this function. Exonucleases are involved in central pathways of cell biology such as DNA replication, repair, and death, as well as tuning the immune response. Of note, malfunctioning of these enzymes is associated with immune disorders and cancer. In this review, we will dissect the impact of DNA degradation on the DNA damage response and its links with inflammation and cancer.
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Affiliation(s)
- Joan Manils
- Serra Húnter Programme, Immunology Unit, Department of Pathology and Experimental Therapy, School of Medicine, Universitat de Barcelona, Feixa Llarga s/n, 08907 L’Hospitalet de Llobregat, Spain;
- Immunity, Inflammation and Cancer Group, Oncobell Program, Institut d’Investigació Biomèdica de Bellvitge—IDIBELL, 08907 L’Hospitalet de Llobregat, Spain
| | - Laura Marruecos
- Breast Cancer Laboratory, Cancer Biology and Stem Cells Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia;
| | - Concepció Soler
- Immunity, Inflammation and Cancer Group, Oncobell Program, Institut d’Investigació Biomèdica de Bellvitge—IDIBELL, 08907 L’Hospitalet de Llobregat, Spain
- Immunology Unit, Department of Pathology and Experimental Therapy, School of Medicine, Universitat de Barcelona, 08007 Barcelona, Spain
- Correspondence:
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19
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Endutkin AV, Yatsenko DD, Zharkov DO. Effect of DNA Methylation on the 3'→5' Exonuclease Activity of Major Human Abasic Site Endonuclease APEX1. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:10-20. [PMID: 35491018 DOI: 10.1134/s0006297922010023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
Apurinic/apyrimidinic (AP) endonucleases are the key enzymes in the DNA base excision repair, as they hydrolyze the phosphodiester bond in the AP site formed after removal of the damaged base. Major human AP endonuclease APEX1 also possesses the 3'-phosphodiesterase and 3'→5' exonuclease activities. The biological role of the latter has not been established yet; it is assumed that it corrects DNA synthesis errors during DNA repair. If DNA is damaged at the 3'-side of 5-methylcytosine (mC) residue, the 3'→5' exonuclease activity can change the epigenetic methylation status of the CpG dinucleotide. It remains unclear whether the 3'→5' exonuclease activity of APEX1 contributes to the active epigenetic demethylation or, on the contrary, is limited in the case of methylated CpG dinucleotides in order to preserve the epigenetic status upon repair of accidental DNA damage. Here, we report the results of the first systematic study on the efficiency of removal of 3'-terminal nucleotides from the substrates modeling DNA repair intermediates in the CpG dinucleotides. The best substrates for the 3'→5' exonuclease activity of APEX1 were oligonucleotides with the 3'-terminal bases non-complementary to the template, while the worst substrates contained mC. The presence of mC in the complementary strand significantly reduced the reaction rate even for the non-complementary 3'-ends. Therefore, the efficiency of the 3'→5' exonuclease reaction catalyzed by APEX1 is limited in the case of the methylated CpG dinucleotides, which likely reflects the need to preserve the epigenetic status during DNA repair.
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Affiliation(s)
- Anton V Endutkin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Darya D Yatsenko
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Dmitry O Zharkov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk, 630090, Russia
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20
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Huang X, He Z, Zhou K, Zhi H, Yang J. Fabrication of bifunctional G-quadruplex-hemin DNAzymes for colorimetric detection of apurinic/apyrimidinic endonuclease 1 and microRNA-21. Analyst 2021; 146:7379-7385. [PMID: 34816841 DOI: 10.1039/d1an01603b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
G-quadruplex-based complexes have been widely used in various analytical methods due to their outstanding capabilities of generating colorimetric, fluorescent or electrochemical signals. However, since loop sequences in traditional G-quadruplex structures are quite short, it is difficult to establish biosensors solely using G-quadruplex-based complexes. Herein, we attempted to lengthen the loop sequences of G-quadruplex structures and found that G-quadruplex-hemin DNAzymes (G-DNAzymes) with long loops (even 30 nucleotides) maintain high peroxidase activity. In addition, the peroxidase activity is not affected by the hybridization of the long loop with its complementary counterpart. Consequently, G-DNAzyme can be endowed with an additional function by taking the long loop as a recognition element, which may facilitate the construction of diverse colorimetric biosensors. Furthermore, by designing an apurinic/apyrimidinic site or a complementary sequence of microRNA-21 (miRNA-21) in long loops, bifunctional G-DNAzymes can be split in the presence of apurinic/apyrimidinic endonuclease 1 (APE1) or miRNA-21, decreasing their peroxidase activities. Accordingly, APE1 and miRNA-21 are quantified using 3,3',5,5'-tetramethylbenzidine as a chromophore. Using the G-DNAzyme, APE1 can be detected in a linear range from 2.5 to 22.5 U mL-1 with a LOD of 1.8 U mL-1. It is to be noted that benefitting from duplex-specific nuclease-induced signal amplification, the linear range of the miRNA-21 biosensor is broadened to 5 orders of magnitude, while the limit of detection is as low as 73 fM. This work demonstrates that G-DNAzymes with long loops can both generate signals and recognize targets, providing an alternative strategy to design G-quadruplex-based analytical methods.
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Affiliation(s)
- Xiaodong Huang
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, P. R. China.
| | - Zhenni He
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, P. R. China.
| | - Kejie Zhou
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, P. R. China.
| | - Huizhen Zhi
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, P. R. China.
| | - Jinfei Yang
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, P. R. China.
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21
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Hossain MA, Lin Y, Driscoll G, Li J, McMahon A, Matos J, Zhao H, Tsuchimoto D, Nakabeppu Y, Zhao J, Yan S. APE2 Is a General Regulator of the ATR-Chk1 DNA Damage Response Pathway to Maintain Genome Integrity in Pancreatic Cancer Cells. Front Cell Dev Biol 2021; 9:738502. [PMID: 34796173 PMCID: PMC8593216 DOI: 10.3389/fcell.2021.738502] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 10/14/2021] [Indexed: 12/18/2022] Open
Abstract
The maintenance of genome integrity and fidelity is vital for the proper function and survival of all organisms. Recent studies have revealed that APE2 is required to activate an ATR-Chk1 DNA damage response (DDR) pathway in response to oxidative stress and a defined DNA single-strand break (SSB) in Xenopus laevis egg extracts. However, it remains unclear whether APE2 is a general regulator of the DDR pathway in mammalian cells. Here, we provide evidence using human pancreatic cancer cells that APE2 is essential for ATR DDR pathway activation in response to different stressful conditions including oxidative stress, DNA replication stress, and DNA double-strand breaks. Fluorescence microscopy analysis shows that APE2-knockdown (KD) leads to enhanced γH2AX foci and increased micronuclei formation. In addition, we identified a small molecule compound Celastrol as an APE2 inhibitor that specifically compromises the binding of APE2 but not RPA to ssDNA and 3′-5′ exonuclease activity of APE2 but not APE1. The impairment of ATR-Chk1 DDR pathway by Celastrol in Xenopus egg extracts and human pancreatic cancer cells highlights the physiological significance of Celastrol in the regulation of APE2 functionalities in genome integrity. Notably, cell viability assays demonstrate that APE2-KD or Celastrol sensitizes pancreatic cancer cells to chemotherapy drugs. Overall, we propose APE2 as a general regulator for the DDR pathway in genome integrity maintenance.
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Affiliation(s)
- Md Akram Hossain
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States
| | - Yunfeng Lin
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States
| | - Garrett Driscoll
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States
| | - Jia Li
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States
| | - Anne McMahon
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States
| | - Joshua Matos
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States
| | - Haichao Zhao
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States
| | - Daisuke Tsuchimoto
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Yusaku Nakabeppu
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Jianjun Zhao
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Shan Yan
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States
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22
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Apurinic/Apyrimidinic Endonuclease 2 (APE2): An ancillary enzyme for contextual base excision repair mechanisms to preserve genome stability. Biochimie 2021; 190:70-90. [PMID: 34302888 DOI: 10.1016/j.biochi.2021.07.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 06/29/2021] [Accepted: 07/19/2021] [Indexed: 01/03/2023]
Abstract
The genome of living organisms frequently undergoes various types of modifications which are recognized and repaired by the relevant repair mechanisms. These repair pathways are increasingly being deciphered to understand the mechanisms. Base excision repair (BER) is indispensable to maintain genome stability. One of the enigmatic repair proteins of BER, Apurinic/Apyrimidinic Endonuclease 2 (APE2), like APE1, is truly multifunctional and demonstrates the independent and non-redundant function in maintaining the genome integrity. APE2 is involved in ATR-Chk1 mediated DNA damage response. It also resolves topoisomerase1 mediated cleavage complex intermediate which is formed while repairing misincorporated ribonucleotides in the absence of functional RNase H2 mediated excision repair pathway. BER participates in the demethylation pathway and the role of Arabidopsis thaliana APE2 is demonstrated in this process. Moreover, APE2 is synthetically lethal to BRCA1, BRCA2, and RNase H2, and its homolog, APE1 fails to complement the function. Hence, the role of APE2 is not just an alternate to the repair mechanisms but has implications in diverse functional pathways related to the maintenance of genome integrity. This review analyses genomic features of APE2 and delineates its enzyme function as error-prone as well as efficient and accurate repair protein based on the studies on mammalian or its homolog proteins from model systems such as Arabidopsis thaliana, Schizosaccharomyces pombe, Trypanosoma curzi, Xenopus laevis, Danio rerio, Mus musculus, and Homo sapiens.
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23
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Liu TC, Guo KW, Chu JW, Hsiao YY. Understanding APE1 cellular functions by the structural preference of exonuclease activities. Comput Struct Biotechnol J 2021; 19:3682-3691. [PMID: 34285771 PMCID: PMC8258793 DOI: 10.1016/j.csbj.2021.06.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 12/17/2022] Open
Abstract
Mammalian apurinic/apyrimidinic (AP) endonuclease 1 (APE1) has versatile enzymatic functions, including redox, endonuclease, and exonuclease activities. APE1 is thus broadly associated with pathways in DNA repair, cancer cell growth, and drug resistance. Unlike its AP site-specific endonuclease activity in Base excision repair (BER), the 3′-5′ exonucleolytic cleavage of APE1 using the same active site exhibits complex substrate selection patterns, which are key to the biological functions. This work aims to integrate molecular structural information and biocatalytic properties to deduce the substrate recognition mechanism of APE1 as an exonuclease and make connection to its diverse functionalities in the cell. In particular, an induced space-filling model emerges in which a bridge-like structure is formed by Arg177 and Met270 (RM bridge) upon substrate binding, causing the active site to adopt a long and narrow product pocket for hosting the leaving group of an AP site or the 3′-end nucleotide. Rather than distinguishing bases as other exonucleases, the hydrophobicity and steric hindrance due to the APE1 product pocket provides selectivity for substrate structures, such as matched or mismatched blunt-ended dsDNA, recessed dsDNA, gapped dsDNA, and nicked dsDNA with 3′-end overhang shorter than 2 nucleotides. These dsDNAs are similar to the native substrates in BER proofreading, BER for trinucleotide repeats (TNR), Nucleotide incision repair (NIR), DNA single-strand breaks (SSB), SSB with damaged bases, and apoptosis. Integration of in vivo studies, in vitro biochemical assays, and structural analysis is thus essential for linking the APE1 exonuclease activity to the specific roles in cellular functions.
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Affiliation(s)
- Tung-Chang Liu
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan.,Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan 30068, Taiwan
| | - Kai-Wei Guo
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan.,Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan 30068, Taiwan
| | - Jhih-Wei Chu
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan.,Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan 30068, Taiwan.,Institute of Bioinformatics and Systems Biology, National Yang Ming Chiao Tung University, Hsinchu, 30068, Taiwan.,Center For Intelligent Drug Systems and Smart Bio-devices (IDSB), National Yang Ming Chiao Tung University, Hsinchu, Taiwan
| | - Yu-Yuan Hsiao
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsinchu 30068, Taiwan.,Department of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan 30068, Taiwan.,Institute of Bioinformatics and Systems Biology, National Yang Ming Chiao Tung University, Hsinchu, 30068, Taiwan.,Center For Intelligent Drug Systems and Smart Bio-devices (IDSB), National Yang Ming Chiao Tung University, Hsinchu, Taiwan.,Drug Development and Value Creation Research Center, Center for Cancer Research, Kaohsiung Medical University, Kaohsiung, Taiwan
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24
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Molecular Mechanisms Regulating the DNA Repair Protein APE1: A Focus on Its Flexible N-Terminal Tail Domain. Int J Mol Sci 2021; 22:ijms22126308. [PMID: 34208390 PMCID: PMC8231204 DOI: 10.3390/ijms22126308] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/08/2021] [Accepted: 06/09/2021] [Indexed: 02/06/2023] Open
Abstract
APE1 (DNA (apurinic/apyrimidinic site) endonuclease 1) is a key enzyme of one of the major DNA repair routes, the BER (base excision repair) pathway. APE1 fulfils additional functions, acting as a redox regulator of transcription factors and taking part in RNA metabolism. The mechanisms regulating APE1 are still being deciphered. Structurally, human APE1 consists of a well-characterized globular catalytic domain responsible for its endonuclease activity, preceded by a conformationally flexible N-terminal extension, acquired along evolution. This N-terminal tail appears to play a prominent role in the modulation of APE1 and probably in BER coordination. Thus, it is primarily involved in mediating APE1 localization, post-translational modifications, and protein–protein interactions, with all three factors jointly contributing to regulate the enzyme. In this review, recent insights on the regulatory role of the N-terminal region in several aspects of APE1 function are covered. In particular, interaction of this region with nucleophosmin (NPM1) might modulate certain APE1 activities, representing a paradigmatic example of the interconnection between various regulatory factors.
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25
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Plasmodium Ape1 is a multifunctional enzyme in mitochondrial base excision repair and is required for efficient transition from liver to blood stage infection. DNA Repair (Amst) 2021; 101:103098. [PMID: 33743509 DOI: 10.1016/j.dnarep.2021.103098] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 03/01/2021] [Accepted: 03/09/2021] [Indexed: 02/02/2023]
Abstract
The malaria parasite has a single mitochondrion which carries multiple tandem repeats of its 6 kb genome encoding three proteins of the electron transport chain. There is little information about DNA repair mechanisms for mitochondrial genome maintenance in Plasmodium spp. Of the two AP-endonucleases of the BER pathway encoded in the parasite nuclear genome, the EndoIV homolog PfApn1 has been identified as a mitochondrial protein with restricted functions. We explored the targeting and biochemical properties of the ExoIII homolog PfApe1. PfApe1 localized in the mitochondrion and exhibited AP-site cleavage, 3'-5' exonuclease, 3'-phosphatase, nucleotide incision repair (NIR) and RNA cleavage activities indicating a wider functional role than PfApn1. The parasite enzyme differed from human APE1 in possessing a large, disordered N-terminal extension. Molecular modelling revealed conservation of structural domains but variations in DNA-interacting residues and an insertion in the α-8 loop suggested differences with APE1. Unlike APE1, where AP-site cleavage and NIR activities could be mutually exclusive based on pH and Mg2+ ion concentration, PfApe1 was optimally active under similar conditions suggesting that it can function both as an AP-endonuclease in BER and directly cleave damaged bases in NIR under similar physiological conditions. To investigate the role of Ape1 in malaria life cycle, we disrupted the gene by double-cross-over homologous recombination. Ape1 knockout (KO) P. berghei parasites showed normal development of blood and mosquito stages. However, inoculation of mice with Ape1 KO salivary gland sporozoites revealed a reduced capacity to initiate blood stage infection. Ape1 KO parasites underwent normal liver stage development until merozoites egressed from hepatocytes. Our results indicated that the delay in pre-patent period was due to the inability of Ape1 KO merosomes to infect erythrocytes efficiently.
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The APEX1/miRNA-27a-5p axis plays key roles in progression, metastasis and targeted chemotherapy of gastric cancer. Int J Pharm 2021; 599:120446. [PMID: 33675923 DOI: 10.1016/j.ijpharm.2021.120446] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 02/10/2021] [Accepted: 02/26/2021] [Indexed: 02/06/2023]
Abstract
Gastric cancer (GC) presents a challenge for conventional therapeutics due to low targeting specificity and subsequent elicitation of multiple drug resistance (MDR). As an essential enzyme for DNA repair, apurinic/apyrimidinic endodeoxyribonuclease 1 (APEX1) exhibits multiple functions to affect cancer malignancy and is excessively expressed in GC. However, the roles APEX1 and its inhibitor miR-27a-5p play in modulating GC progression and MDR development remains unclear. Here, we verified APEX1 as a target of miR-27a-5p and subsequently established the APEX1-deleted SGC-7901 cell line by CRISPR/Cas9 editing. The roles of the APEX1/miR-27a-5p axis in GC progression, metastasis and doxorubicin (DOX) resistance were explored by the targeted chemotherapy facilitated by a GC-specific peptide (GP5) functionalized liposomal drug delivery formulation (GP5/Lipo/DOX/miR-27a-5p). The results showed that APEX1 deletion distinctly attenuated cell growth and metastatic properties in GC, and also sensitized GC cells to DOX. Notably, miR-27a-5p was validated as a suppressor of APEX1-dependent GC development and DOX resistance by a RAS/MEK/FOS and PTEN/AKT/SMAD2 pathway-dependent manner. The altered expression of epithelial-mesenchymal transition (EMT) signatures and signal pathway proteins in the APEX1-deleted cells implied that APEX1 potentially enhances DOX resistance of GC cells by altering the regulation of MAPK and AKT pathways, leading to compromised efficacy of chemotherapy or by initiating additional DNA damage response pathways. Taken together, these findings revealed that as a novel therapeutic target, APEX1/miR-27a-5p axis plays essential roles in modulating the GC development and MDR, and the GC targeted drug delivery formulation presents a strategic reference for the future designation of chemotherapeutics study.
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Zhang Y, Chen J, Che Z, Shu C, Chen D, Ding K, Li A, Zhou J. JP3 enhances the toxicity of cisplatin on drug-resistant gastric cancer cells while reducing the damage to normal cells. J Cancer 2021; 12:1894-1906. [PMID: 33753987 PMCID: PMC7974513 DOI: 10.7150/jca.50306] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 01/03/2021] [Indexed: 01/26/2023] Open
Abstract
Background: Cisplatin (DDP) is a highly effective chemotherapeutic agent to most solid tumors including gastric cancer (GC), however, its clinical value is limited due to severe toxic side effects and secondary drug resistance. JP3, a JWA protein based MMP2-targeted polypeptide, known to inhibit the growth of GC in vivo. However, the bidirectional effects of JP3 in DDP-resistant GC and normal cells have not been demonstrated. The present study aims to investigate the actions of JP3 on protecting normal cells from the toxicity of DDP while enhancing its anti-tumor effects on GC cells. Methods: Routine laboratory experimental methods including CCK-8 assay, Western blotting, Hoechst staining, immunofluorescence (IF) and qRT-PCR were used in mechanism investigation; protein docking analysis and coimmunoprecipitation (Co-IP) were used for prediction and confirmation of interactions between JP3 and CK2. Mouse xenograft model was used for screening the treatment of JP3 plus DDP on GC growth. Results: DDP showed similar toxicities to normal cells and DDP-resistant GC cells; JP3 competitively inhibited the binding of XRCC1 to CK2, reduced the DNA repair and anti-apoptosis capacity of DDP-resistant GC cells in combination with DDP treatment; meanwhile, JP3 protected normal cells from DDP-induced oxidative stress and DNA damage through ERK/Nrf2 signaling. JP3 combined with DDP showed similar bidirectional effects in vivo. Conclusions: JP3 enhanced the inhibitory effects of DDP on tumor growth while reduced toxic side effects of DDP on normal cells. The results of this study provide a new insight for the treatment of drug-resistant GC.
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Affiliation(s)
- Yi Zhang
- Department of Molecular Cell Biology & Toxicology, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, China
| | - Junjie Chen
- Department of Molecular Cell Biology & Toxicology, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, China
| | - Zhen Che
- Department of Molecular Cell Biology & Toxicology, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, China
| | - Chuanjun Shu
- Department of Bioinformatics, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing 211166, China
| | - Dongyin Chen
- Department of Medicinal Chemistry, School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Kun Ding
- Department of Molecular Cell Biology & Toxicology, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, China
| | - Aiping Li
- Department of Molecular Cell Biology & Toxicology, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, China
| | - Jianwei Zhou
- Department of Molecular Cell Biology & Toxicology, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, China
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Saitoh T, Oda T. DNA Damage Response in Multiple Myeloma: The Role of the Tumor Microenvironment. Cancers (Basel) 2021; 13:504. [PMID: 33525741 PMCID: PMC7865954 DOI: 10.3390/cancers13030504] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/21/2021] [Accepted: 01/26/2021] [Indexed: 12/13/2022] Open
Abstract
Multiple myeloma (MM) is an incurable plasma cell malignancy characterized by genomic instability. MM cells present various forms of genetic instability, including chromosomal instability, microsatellite instability, and base-pair alterations, as well as changes in chromosome number. The tumor microenvironment and an abnormal DNA repair function affect genetic instability in this disease. In addition, states of the tumor microenvironment itself, such as inflammation and hypoxia, influence the DNA damage response, which includes DNA repair mechanisms, cell cycle checkpoints, and apoptotic pathways. Unrepaired DNA damage in tumor cells has been shown to exacerbate genomic instability and aberrant features that enable MM progression and drug resistance. This review provides an overview of the DNA repair pathways, with a special focus on their function in MM, and discusses the role of the tumor microenvironment in governing DNA repair mechanisms.
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Affiliation(s)
- Takayuki Saitoh
- Department of Laboratory Sciences, Graduate School of Health Sciences, Gunma University, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
| | - Tsukasa Oda
- Laboratory of Molecular Genetics, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi, Gunma 371-8512, Japan;
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Liu TC, Lin CT, Chang KC, Guo KW, Wang S, Chu JW, Hsiao YY. APE1 distinguishes DNA substrates in exonucleolytic cleavage by induced space-filling. Nat Commun 2021; 12:601. [PMID: 33504804 PMCID: PMC7841161 DOI: 10.1038/s41467-020-20853-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 12/22/2020] [Indexed: 11/09/2022] Open
Abstract
The exonuclease activity of Apurinic/apyrimidinic endonuclease 1 (APE1) is responsible for processing matched/mismatched terminus in various DNA repair pathways and for removing nucleoside analogs associated with drug resistance. To fill in the gap of structural basis for exonucleolytic cleavage, we determine the APE1-dsDNA complex structures displaying end-binding. As an exonuclease, APE1 does not show base preference but can distinguish dsDNAs with different structural features. Integration with assaying enzyme activity and binding affinity for a variety of substrates reveals for the first time that both endonucleolytic and exonucleolytic cleavage can be understood by an induced space-filling model. Binding dsDNA induces RM (Arg176 and Met269) bridge that defines a long and narrow product pocket for exquisite machinery of substrate selection. Our study paves the way to comprehend end-processing of dsDNA in the cell and the drug resistance relating to APE1.
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Affiliation(s)
- Tung-Chang Liu
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu, 30068, Taiwan.,Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 30068, Taiwan
| | - Chun-Ting Lin
- Master's and Doctoral Degree Program for Science and Technology of Accelerator Light Sources, National Chiao Tung University, Hsinchu, 30068, Taiwan
| | - Kai-Cheng Chang
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 30068, Taiwan
| | - Kai-Wei Guo
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 30068, Taiwan
| | - Shuying Wang
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Biotechnology and Bioindustry Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan
| | - Jhih-Wei Chu
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu, 30068, Taiwan.,Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 30068, Taiwan.,Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, 30068, Taiwan.,Center For Intelligent Drug Systems and Smart Bio-devices (IDS2B), National Chiao Tung University, Hsinchu, Taiwan
| | - Yu-Yuan Hsiao
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu, 30068, Taiwan. .,Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 30068, Taiwan. .,Master's and Doctoral Degree Program for Science and Technology of Accelerator Light Sources, National Chiao Tung University, Hsinchu, 30068, Taiwan. .,Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, 30068, Taiwan. .,Center For Intelligent Drug Systems and Smart Bio-devices (IDS2B), National Chiao Tung University, Hsinchu, Taiwan. .,Drug Development and Value Creation Research Center, Center for Cancer Research, Kaohsiung Medical University, Kaohsiung, Taiwan.
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30
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Approaches for the sensitive detection of rare base and prime editing events. Methods 2021; 194:75-82. [PMID: 33484827 DOI: 10.1016/j.ymeth.2021.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 01/11/2021] [Accepted: 01/18/2021] [Indexed: 12/23/2022] Open
Abstract
Precision chemistry entailing user-directed nucleotide substitutions and template-specified repair can be facilitated by base editing and prime editing, respectively. Recently, the diversification of adenine, cytosine, and prime editor variants obliges a considered, high-throughput evaluation of these tools for optimized, end-point applications. Herein, we outline novel, cost-effective and scalable approaches for the rapid detection of base editing and prime editing outcomes using gel electrophoresis. For base editing, we exploit primer mismatch amplification (SNP genotyping) for the gel-based detection of base editing efficiencies as low as 0.1%. For prime editing, we describe a one-pot reaction combining polymerase chain reaction (PCR) amplification of the target region with restriction digestion (restriction fragment length polymorphism; RFLP). RFLP enables the rapid detection of insertion or deletion events in under 2.5 h from genomic DNA extraction. We show that our method of SNP genotyping is amenable to both endogenous target loci as well as transfected, episomal plasmid targets in BHK-21 cells. Next, we validate the incidence of base and prime editing by describing Sanger sequencing and next-generation sequencing (NGS) workflows for the accurate validation and quantification of on-target editing efficiencies. Our workflow details three different methods for the detection of rare base and prime editing events, enabling a tiered approach from low to high resolution that makes use of gel electrophoresis, Sanger sequencing, and NGS.
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31
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Gorini F, Scala G, Cooke MS, Majello B, Amente S. Towards a comprehensive view of 8-oxo-7,8-dihydro-2'-deoxyguanosine: Highlighting the intertwined roles of DNA damage and epigenetics in genomic instability. DNA Repair (Amst) 2021; 97:103027. [PMID: 33285475 PMCID: PMC7926032 DOI: 10.1016/j.dnarep.2020.103027] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 11/16/2020] [Indexed: 12/12/2022]
Abstract
8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), a major product of DNA oxidation, is a pre-mutagenic lesion which is prone to mispair, if left unrepaired, with 2'-deoxyadenosine during DNA replication. While unrepaired or incompletely repaired 8-oxodG has classically been associated with genome instability and cancer, it has recently been reported to have a role in the epigenetic regulation of gene expression. Despite the growing collection of genome-wide 8-oxodG mapping studies that have been used to provide new insight on the functional nature of 8-oxodG within the genome, a comprehensive view that brings together the epigenetic and the mutagenic nature of the 8-oxodG is still lacking. To help address this gap, this review aims to provide (i) a description of the state-of-the-art knowledge on both the mutagenic and epigenetic roles of 8-oxodG; (ii) putative molecular models through which the 8-oxodG can cause genome instability; (iii) a possible molecular model on how 8-oxodG, acting as an epigenetic signal, could cause the translocations and deletions which are associated with cancer.
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Affiliation(s)
- Francesca Gorini
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples 'Federico II', Naples, Italy
| | - Giovanni Scala
- Department of Biology, University of Naples 'Federico II', Naples, Italy
| | - Marcus S Cooke
- Oxidative Stress Group, Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL, USA
| | - Barbara Majello
- Department of Biology, University of Naples 'Federico II', Naples, Italy
| | - Stefano Amente
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples 'Federico II', Naples, Italy.
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32
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Lin Y, McMahon A, Driscoll G, Bullock S, Zhao J, Yan S. Function and molecular mechanisms of APE2 in genome and epigenome integrity. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2020; 787:108347. [PMID: 34083046 DOI: 10.1016/j.mrrev.2020.108347] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/30/2020] [Accepted: 11/10/2020] [Indexed: 02/06/2023]
Abstract
APE2 is a rising vital player in the maintenance of genome and epigenome integrity. In the past several years, a series of studies have shown the critical roles and functions of APE2. We seek to provide the first comprehensive review on several aspects of APE2 in genome and epigenome integrity. We first summarize the distinct functional domains or motifs within APE2 including EEP (endonuclease/exonuclease/phosphatase) domain, PIP box and Zf-GRF motifs from eight species (i.e., Homo sapiens, Mus musculus, Xenopus laevis, Ciona intestinalis, Arabidopsis thaliana, Schizosaccharomyces pombe, Saccharomyces cerevisiae, and Trypanosoma cruzi). Then we analyze various APE2 nuclease activities and associated DNA substrates, including AP endonuclease, 3'-phosphodiesterase, 3'-phosphatase, and 3'-5' exonuclease activities. We also examine several APE2 interaction proteins, including PCNA, Chk1, APE1, Myh1, and homologous recombination (HR) factors such as Rad51, Rad52, BRCA1, BRCA2, and BARD1. Furthermore, we provide insights into the roles of APE2 in various DNA repair pathways (base excision repair, single-strand break repair, and double-strand break repair), DNA damage response (DDR) pathways (ATR-Chk1 and p53-dependent), immunoglobulin class switch recombination and somatic hypermutation, as well as active DNA demethylation. Lastly, we summarize critical functions of APE2 in growth, development, and diseases. In this review, we provide the first comprehensive perspective which dissects all aspects of the multiple-function protein APE2 in genome and epigenome integrity.
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Affiliation(s)
- Yunfeng Lin
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, 28223, United States
| | - Anne McMahon
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, 28223, United States
| | - Garrett Driscoll
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, 28223, United States
| | - Sharon Bullock
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, 28223, United States
| | - Jianjun Zhao
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, United States
| | - Shan Yan
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, 28223, United States.
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33
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Zhu W, Hu J, Chi J, Li Y, Yang B, Hu W, Chen F, Xu C, Chai L, Bao Y. Label-Free Proteomics Reveals the Molecular Mechanism of Subculture Induced Strain Degeneration and Discovery of Indicative Index for Degeneration in Pleurotus ostreatus. Molecules 2020; 25:molecules25214920. [PMID: 33114310 PMCID: PMC7660624 DOI: 10.3390/molecules25214920] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 10/13/2020] [Accepted: 10/19/2020] [Indexed: 11/16/2022] Open
Abstract
Pleurotus ostreatus is one of the widely cultivated edible fungi across the world. Mycelial subculture is an indispensable part in the process of cultivation and production for all kinds of edible fungi. However, successive subcultures usually lead to strain degeneration. The degenerated strains usually have a decrease in stress resistance, yield, and an alteration in fruiting time, which will subsequently result in tremendous economic loss. Through proteomic analysis, we identified the differentially expressed proteins (DEPs) in the mycelium of Pleurotus ostreatus from different subcultured generations. We found that the DNA damage repair system, especially the double-strand breaks (DSBs), repairs via homologous recombination, was impaired in the subcultured mycelium, and gradual accumulation of the DSBs would lead to the strain degeneration after successive subculture. The TUNEL assay further confirmed our finding about the DNA breaks in the subcultured mycelium. Interestingly, the enzyme activity of laccase, carboxylic ester hydrolase, α-galactosidase, and catalase directly related to passage number could be used as the characteristic index for strain degeneration determination. Our results not only reveal for the first time at the molecular level that genomic instability is the cause of degeneration, but also provide an applicable approach for monitoring strain degeneration in process of edible fungi cultivation and production.
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Affiliation(s)
- Weiwei Zhu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China;
- Microbial Research Institute of Liaoning Province, Chaoyang 122000, China; (J.C.); (Y.L.); (F.C.); (C.X.); (L.C.)
| | - Jinbo Hu
- Laboratory of Photosynthesis and Environment, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; (J.H.); (B.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingliang Chi
- Microbial Research Institute of Liaoning Province, Chaoyang 122000, China; (J.C.); (Y.L.); (F.C.); (C.X.); (L.C.)
| | - Yang Li
- Microbial Research Institute of Liaoning Province, Chaoyang 122000, China; (J.C.); (Y.L.); (F.C.); (C.X.); (L.C.)
| | - Bing Yang
- Laboratory of Photosynthesis and Environment, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; (J.H.); (B.Y.)
| | - Wenli Hu
- Core Facility Center, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China;
| | - Fei Chen
- Microbial Research Institute of Liaoning Province, Chaoyang 122000, China; (J.C.); (Y.L.); (F.C.); (C.X.); (L.C.)
| | - Chong Xu
- Microbial Research Institute of Liaoning Province, Chaoyang 122000, China; (J.C.); (Y.L.); (F.C.); (C.X.); (L.C.)
| | - Linshan Chai
- Microbial Research Institute of Liaoning Province, Chaoyang 122000, China; (J.C.); (Y.L.); (F.C.); (C.X.); (L.C.)
| | - Yongming Bao
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China;
- School of Ocean Science and Technology, Dalian University of Technology, Panjin 124021, China
- Correspondence: ; Tel.: +86-427-2631777; Fax: +86-411-84706365
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34
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Ha A, Lin Y, Yan S. A non-canonical role for the DNA glycosylase NEIL3 in suppressing APE1 endonuclease-mediated ssDNA damage. J Biol Chem 2020; 295:14222-14235. [PMID: 32817342 DOI: 10.1074/jbc.ra120.014228] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 08/11/2020] [Indexed: 12/21/2022] Open
Abstract
The DNA glycosylase NEIL3 has been implicated in DNA repair pathways including the base excision repair and the interstrand cross-link repair pathways via its DNA glycosylase and/or AP lyase activity, which are considered canonical roles of NEIL3 in genome integrity. Compared with the other DNA glycosylases NEIL1 and NEIL2, Xenopus laevis NEIL3 C terminus has two highly conserved zinc finger motifs containing GRXF residues (designated as Zf-GRF). It has been demonstrated that the minor AP endonuclease APE2 contains only one Zf-GRF motif mediating interaction with single-strand DNA (ssDNA), whereas the major AP endonuclease APE1 does not. It appears that the two NEIL3 Zf-GRF motifs (designated as Zf-GRF repeat) are dispensable for its DNA glycosylase and AP lyase activity; however, the potential function of the NEIL3 Zf-GRF repeat in genome integrity remains unknown. Here, we demonstrate evidence that the NEIL3 Zf-GRF repeat was associated with a higher affinity for shorter ssDNA than one single Zf-GRF motif. Notably, our protein-protein interaction assays show that the NEIL3 Zf-GRF repeat but not one Zf-GRF motif interacted with APE1 but not APE2. We further reveal that APE1 endonuclease activity on ssDNA but not on dsDNA is compromised by a NEIL3 Zf-GRF repeat, whereas one Zf-GRF motif within NEIL3 is not sufficient to prevent such activity of APE1. In addition, COMET assays show that excess NEIL3 Zf-GRF repeat reduces DNA damage in oxidative stress in Xenopus egg extracts. Together, our results suggest a noncanonical role of NEIL3 in genome integrity via its distinct Zf-GRF repeat in suppressing APE1 endonuclease-mediated ssDNA breakage.
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Affiliation(s)
- Anh Ha
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Yunfeng Lin
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
| | - Shan Yan
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
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35
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Yan S, Vaziri C. An introduction for the special issue on environmental health and genome integrity. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:660-663. [PMID: 32683747 PMCID: PMC7442621 DOI: 10.1002/em.22400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 07/15/2020] [Indexed: 05/23/2023]
Abstract
Environmental exposures and genome maintenance mechanisms that respond to environmentally-induced genotoxicity have a profound impact on human health. Eight review articles in this Special Issue (SI) titled "Environmental Health and Genome Integrity" describe emerging new mechanisms by which distinct forms of environmentally-induced DNA damage are remediated, and explain how DNA repair pathway choices impact genome integrity and disease propensity. Here, we provide an introduction to reviews from this SI. Our expanding knowledge of how genotoxic exposures impact the genome will allow us to better predict, prevent and treat environmentally-induced human diseases such as cancer and neurodegenerative disorders.
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Affiliation(s)
- Shan Yan
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina
| | - Cyrus Vaziri
- Department of Pathology and Laboratory Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina
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36
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Zheng R, Zhu HL, Hu BR, Ruan XJ, Cai HJ. Identification of APEX2 as an oncogene in liver cancer. World J Clin Cases 2020; 8:2917-2929. [PMID: 32775374 PMCID: PMC7385600 DOI: 10.12998/wjcc.v8.i14.2917] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/27/2020] [Accepted: 06/12/2020] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND DNA damage is one of the critical contributors to the occurrence and development of some cancers. APEX1 and APEX2 are the most important molecules in the DNA damage, and APEX1 has been identified as a diagnostic and prognostic biomarker in liver hepatocellular carcinoma (LIHC). However, the expression of APEX2 and its functional mechanisms in LIHC are still unclear. AIM To examine the expression of APEX2 and the potential mechanism network in LIHC. METHODS We conducted a pan-cancer analysis of the expression of APEX1 and APEX2 using the interactive TIMER tool. GEO datasets, including GSE14520, GSE22058, and GSE64041, were used to compare the APEX2 expression level in tumor tissues and adjacent non-tumor tissues. Then, we calculated the 5-year survival rate according to the web-based Kaplan-Meier analysis. We included the TCGA liver cancer database in GSEA analysis based on the high and low APEX2 expression, showing the potential mechanisms of APEX2 in LIHC. After that, we conducted Pearson correlation analysis using GEPIA2. Next, we performed quantitative polymerase chain reaction (qPCR) assay to examine the APEX2 levels in normal liver cell line LO2 and several liver cancer cell lines, including HepG2, Huh7, SMMC7721, and HCCLM3. APEX2 in HCCLM3 cells was knocked down using small interfering RNA. The role of APEX2 in cell viability was confirmed using CCK-8. Dual-luciferase reporter assay was performed to examine the promoter activity of CCNB1 and MYC. RESULTS APEX1 and APEX2 are both highly expressed in the tumor tissues of BLCA, BRCA, CHOL, COAD, ESCA, HNSC, LIHC, LUAD, LUSC, READ, and STAD. APEX2 overexpression in LIHC was validated using GSE14520, GSE22058, and GSE64041 datasets. The survival analysis showed that LIHC patients with high expression of APEX2 had a lower overall survival rate, even in the AJCC T1 patients. High level of APEX2 could indicate a lower overall survival rate in patients with or without viral hepatitis. The GSEA analysis identified that kinetochore and spindle microtubules are the two main cellular components of APEX2 in GO Ontology. APEX2 was also positively associated with molecular function regulation of chromosome segregation and DNA replication. The results of KEGG analysis indicated that APEX2 expression was positively correlated with cell cycle pathway and pro-oncogenic MYC signaling. Pearson correlation analysis showed that APEX2 had a significant positive correlation with CCNB1 and MYC. APEX2 level was higher in liver cancer cell lines than in normal liver LO2 cells. Small interfering RNA could knock down the APEX2 expression in HCCLM3 cells. Knockdown of APEX2 resulted in a decrease in the viability of HCCLM3 cells as well as the expression and promoter activity of CCNB1 and MYC. CONCLUSION APEX2 is overexpressed in LIHC, and the higher APEX2 level is associated with a worse prognosis in overall survival. APEX2 is closely involved in the biological processes of chromosome segregation and DNA replication. APEX2 expression is positively correlated with the pro-oncogenic pathways. Knockdown of APEX2 could inhibit the cell viability and CCNB1 and MYC pathways, suggesting that APEX2 is an oncogene in LIHC, which could be a potential pharmaceutic target in the anti-tumor therapy.
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Affiliation(s)
- Ru Zheng
- Department of General Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China
| | - Heng-Liang Zhu
- Department of General Surgery, Shenzhen University General Hospital, Shenzhen 518107, Guangdong Province, China
| | - Bing-Ren Hu
- Department of General Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China
| | - Xiao-Jiao Ruan
- Department of General Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China
| | - Hua-Jie Cai
- Department of General Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China
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Genomic alterations and abnormal expression of APE2 in multiple cancers. Sci Rep 2020; 10:3758. [PMID: 32111912 PMCID: PMC7048847 DOI: 10.1038/s41598-020-60656-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/13/2020] [Indexed: 12/26/2022] Open
Abstract
Although APE2 plays essential roles in base excision repair and ATR-Chk1 DNA damage response (DDR) pathways, it remains unknown how the APE2 gene is altered in the human genome and whether APE2 is differentially expressed in cancer patients. Here, we report multiple-cancer analyses of APE2 genomic alterations and mRNA expression from cancer patients using available data from The Cancer Genome Atlas (TCGA). We observe that APE2 genomic alterations occur at ~17% frequency in 14 cancer types (n = 21,769). Most frequent somatic mutations of APE2 appear in uterus (2.89%) and skin (2.47%) tumor samples. Furthermore, APE2 expression is upregulated in tumor tissue compared with matched non-malignant tissue across 5 cancer types including kidney, breast, lung, liver, and uterine cancers, but not in prostate cancer. We also examine the mRNA expression of 13 other DNA repair and DDR genes from matched samples for 6 cancer types. We show that APE2 mRNA expression is positively correlated with PCNA, APE1, XRCC1, PARP1, Chk1, and Chk2 across these 6 tumor tissue types; however, groupings of other DNA repair and DDR genes are correlated with APE2 with different patterns in different cancer types. Taken together, this study demonstrates alterations and abnormal expression of APE2 from multiple cancers.
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