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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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2
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Label-free and highly sensitive APE1 detection based on rolling circle amplification combined with G-quadruplex. Talanta 2022; 244:123404. [PMID: 35349840 DOI: 10.1016/j.talanta.2022.123404] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 03/12/2022] [Accepted: 03/22/2022] [Indexed: 12/13/2022]
Abstract
The highly sensitive detection of low-abundant apurinic/apyrimidinic endonuclease 1 (APE1) activity is of great significance for early diagnosis of disease and pathological research. Many methods for detecting APE1 based on isothermal nucleic acids amplification have been developed for improving its sensitivity. However, some of these methods have certain limitations, such as multiple reaction steps, narrow linear range, and complicated processes for fluorescent labeling. Herein, we develop a highly sensitive and label-free APE1 fluorescence detection method based on rolling circle amplification combined with G-quadruplex (RCA-G4). A hairpin probe (HP) labeled with the AP site can be recognized and cleaved by APE1, leading to the release of the primer sequence, which triggered RCA to produce long chain amplification products with a great amount of repeated sequences. The formed amplicon contains a series G-quadruplex structure, which can be combined with Thioflavin T (ThT) to produce fluorescence and achieve high sensitivity label-free detection of APE1. Benefit from the high amplification efficiency of RCA and the high fluorescence quantum yield of G-quadruplex/ThT, a detection limit as low as 1.52 × 10-6 U/mL and the linear range from 2 × 10-6 to 10 U/mL were obtained. The developed RCA-G4 method can be successfully used to detect APE1 in serum samples with a recovery from 96.3% to 105.7%. We believe that this approach is expected to play an important role in APE1-related disease research and drug development.
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3
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Fleming AM, Manage SAH, Burrows CJ. Binding of AP endonuclease-1 to G-quadruplex DNA depends on the N-terminal domain, Mg 2+ and ionic strength. ACS BIO & MED CHEM AU 2021; 1:44-56. [PMID: 35005714 DOI: 10.1021/acsbiomedchemau.1c00031] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The base excision repair enzyme apurinic/apyrimidinic endonuclease-1 (APE1) is also engaged in transcriptional regulation. APE1 can function in both pathways when the protein binds to a promoter G-quadruplex (G4) bearing an abasic site (modeled with tetrahydrofuran, F) that leads to enzymatic stalling on the non-canonical fold to recruit activating transcription factors. Biochemical and biophysical studies to address APE1's binding and catalytic activity with the vascular endothelial growth factor (VEGF) promoter G4 are lacking, and the present work provides insight on this topic. Herein, the native APE1 was used for cleavage assays, and the catalytically inactive mutant D210A was used for binding assays with double-stranded DNA (dsDNA) versus the native G4 or the G4 with F at various positions, revealing dependencies of the interaction on the cation concentrations K+ and Mg2+ and the N-terminal domain of the protein. Assays in 0, 1, or 10 mM Mg2+ found that dsDNA and G4 substrates required the cation for both binding and catalysis, in which G4 binding increased with [Mg2+]. Studies with 50 versus physiological 140 mM K+ ions showed that F-containing dsDNA was bound and cleaved by APE1; whereas, the G4s with F were poorly cleaved in low salt and not cleaved at all at higher salt while the binding remained robust. Using Δ33 or Δ61 N-terminal truncated APE1 proteins, the binding and cleavage of dsDNA with F was minimally impacted; in contrast, the G4s required the N-terminus for binding and catalysis is nearly abolished without the N-terminus. With this knowledge, we found APE1 could remodel the F-containing VEGF promoter dsDNA→G4 folds in solution. Lastly, the addition of the G4 ligand pyridostatin inhibited APE1 binding and cleavage of F-containing G4s but not dsDNA. The biological and medicinal chemistry implications of the results are discussed.
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Affiliation(s)
- Aaron M Fleming
- Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, UT 84112-0850, United States
| | - Shereen A Howpay Manage
- Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, UT 84112-0850, United States
| | - Cynthia J Burrows
- Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, UT 84112-0850, United States
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Vitexin inhibits APEX1 to counteract the flow-induced endothelial inflammation. Proc Natl Acad Sci U S A 2021; 118:2115158118. [PMID: 34810252 DOI: 10.1073/pnas.2115158118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2021] [Indexed: 12/18/2022] Open
Abstract
Vascular endothelial cells are exposed to shear stresses with disturbed vs. laminar flow patterns, which lead to proinflammatory vs. antiinflammatory phenotypes, respectively. Effective treatment against endothelial inflammation and the consequent atherogenesis requires the identification of new therapeutic molecules and the development of drugs targeting these molecules. Using Connectivity Map, we have identified vitexin, a natural flavonoid, as a compound that evokes the gene-expression changes caused by pulsatile shear, which mimics laminar flow with a clear direction, vs. oscillatory shear (OS), which mimics disturbed flow without a clear direction. Treatment with vitexin suppressed the endothelial inflammation induced by OS or tumor necrosis factor-α. Administration of vitexin to mice subjected to carotid partial ligation blocked the disturbed flow-induced endothelial inflammation and neointimal formation. In hyperlipidemic mice, treatment with vitexin ameliorated atherosclerosis. Using SuperPred, we predicted that apurinic/apyrimidinic endonuclease1 (APEX1) may directly interact with vitexin, and we experimentally verified their physical interactions. OS induced APEX1 nuclear translocation, which was inhibited by vitexin. OS promoted the binding of acetyltransferase p300 to APEX1, leading to its acetylation and nuclear translocation. Functionally, knocking down APEX1 with siRNA reversed the OS-induced proinflammatory phenotype, suggesting that APEX1 promotes inflammation by orchestrating the NF-κB pathway. Animal experiments with the partial ligation model indicated that overexpression of APEX1 negated the action of vitexin against endothelial inflammation, and that endothelial-specific deletion of APEX1 ameliorated atherogenesis. We thus propose targeting APEX1 with vitexin as a potential therapeutic strategy to alleviate atherosclerosis.
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Bhakat KK, Ray S. The FAcilitates Chromatin Transcription (FACT) complex: Its roles in DNA repair and implications for cancer therapy. DNA Repair (Amst) 2021; 109:103246. [PMID: 34847380 DOI: 10.1016/j.dnarep.2021.103246] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 10/07/2021] [Accepted: 11/03/2021] [Indexed: 12/17/2022]
Abstract
Genomic DNA in the nucleus is wrapped around nucleosomes, a repeating unit of chromatin. The nucleosome, consisting of octamer of core histones, is a barrier for several cellular processes that require access to the naked DNA. The FAcilitates Chromatin Transcription (FACT), a histone chaperone complex, is involved in nucleosome remodeling via eviction or assembly of histones during transcription, replication, and DNA repair. Increasing evidence suggests that FACT plays an important role in multiple DNA repair pathways including transcription-coupled nucleotide excision repair (TC-NER) of UV-induced damage, DNA single- and double-strand breaks (DSBs) repair, and base excision repair (BER) of oxidized or alkylated damaged bases. Further, studies have shown overexpression of FACT in multiple types of cancer and its association with drug resistance and patients' poor prognosis. In this review, we discuss how FACT is accumulated at the damage site and what functions it performs. We describe the known mechanisms by which FACT facilitates repair of different types of DNA damage. Further, we highlight the recent advances in a class of FACT inhibitors, called curaxins, which show promise as a new adjuvant therapy to sensitize multiple types of cancer to chemotherapy and radiation.
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Affiliation(s)
- Kishor K Bhakat
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA 68198; Fred and Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA 68198.
| | - Sutapa Ray
- Department of Pediatric, Division of Hematology/oncology, University of Nebraska Medical Center, Omaha, NE, USA 68198; Fred and Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA 68198
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Song H, Zeng J, Lele S, LaGrange CA, Bhakat KK. APE1 and SSRP1 is overexpressed in muscle invasive bladder cancer and associated with poor survival. Heliyon 2021; 7:e06756. [PMID: 33948507 PMCID: PMC8080038 DOI: 10.1016/j.heliyon.2021.e06756] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 03/18/2021] [Accepted: 04/06/2021] [Indexed: 12/22/2022] Open
Abstract
Background Human apurinic/apyrimidinic (AP) endonuclease 1 (APE1) plays a critical role in DNA base excision repair (BER) pathway and has been reported to be overexpressed in multiple cancers. Previously, we have shown that histone chaperone FACT complex (Facilitates Chromatin Transcription, a heterodimer of SSRP1 and SPT16 proteins) facilitates the chromatin access and DNA repair function of APE1, and their expression levels are correlated with promoting drug resistance in cancer. FACT inhibitor has been introduced in phase I and II clinical trials for chemosensitization of advanced solid cancers. However, the expression profile and prognostic significance of APE1 and FACT complex in bladder cancer remains largely unknown. Methods Retrospectively, 69 bladder cancer samples were retrieved and submitted for immunohistochemical staining of APE1 and SSRP1. Expression profile including cytoplasmic and nuclear staining of APE1 and expression level of SSRP1 was examined and semi-quantified to render a H-score. The prognostic significance of APE1 and SSRP1 was evaluated by Kaplan-Meier survival analysis in our cohort and R2 database. Results APE1 expression is elevated in bladder cancer compared to normal adjacent tissues. Compared with low grade tumors, high grade tumors show a shift in the staining pattern including higher intensity and positive cytoplasmic staining. Carcinoma in situ has a similar staining pattern to high grade tumors. APE1 and SSRP1 staining intensity increases as tumor progresses with stage. There is a correlation between APE1 and SSRP1 staining in invasive bladder cancer (Spearman r = 0.5466, p < 0.0001). The increased expression of APE1 and SSRP1 is associated with poor survival in Kaplan-Meier analysis in our cohort and in R2-TCGA bladder cancer database. Conclusions The expression levels of APE1 and SSRP1 are significantly elevated in bladder cancer as compared to normal adjacent tissues. APE1 correlates with SSRP1 expression in high grade tumors. Overexpression of APE1 and SSRP1 is associated with poor survival in bladder cancer. This suggests the usage of FACT inhibitor curaxins in muscle invasive bladder cancer to target FACT complex and APE1 to improve chemosensitization after further validation.
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Affiliation(s)
- Heyu Song
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, United States
| | - Jiping Zeng
- College of Medicine, University of Nebraska Medical Center, Omaha, NE, United States.,Department of Urology, University of Arizona College of Medicine, Tucson, AZ, United States
| | - Subodh Lele
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States
| | - Chad A LaGrange
- Division of Urologic Surgery, Department of Surgery, University of Nebraska Medical Center, Omaha, NE, United States.,Fred & Pamela Buffett Cancer Center, Omaha, NE, United States
| | - Kishor K Bhakat
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, United States.,Fred & Pamela Buffett Cancer Center, Omaha, NE, United States
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Hu J, Xia X, Zhao Q, Li S. Lysine acetylation of NKG2D ligand Rae-1 stabilizes the protein and sensitizes tumor cells to NKG2D immune surveillance. Cancer Lett 2021; 502:143-153. [PMID: 33279621 PMCID: PMC10142196 DOI: 10.1016/j.canlet.2020.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 11/23/2020] [Accepted: 12/01/2020] [Indexed: 02/08/2023]
Abstract
Shedding, loss of expression, or internalization of natural killer group 2, member D (NKG2D) ligands from the tumor cell surface leads to immune evasion, which is associated with poor prognosis in patients with cancer. In many cancers, matrix metalloproteinases cause the proteolytic shedding of NKG2D ligands. However, it remained unclear how to protect NKG2D ligands from shedding. Here, we showed that the shedding of the mouse NKG2D ligand Rae-1 can be prevented by two critical acetyltransferases, GCN5 and PCAF, which acetylate the lysine residues of Rae-1 to avoid shedding both in vitro and in vivo. In contrast, mutations at lysines 80 and 87 of Rae-1 abrogated this acetylation and thereby desensitized tumor cells to NKG2D-dependent immune surveillance. Notably, the protein levels of GCN5 correlated with the expression levels of the human NKG2D ligand ULPB1 in a human tumor tissue microarray and, more importantly, with prolonged overall survival in many cancers. Our results suggest that the acetylation of Rae-1 protein at lysines 80 and 87 by GCN5 and PCAF protects Rae-1 from shedding so as to activate NKG2D-dependent immune surveillance. This discovery may shed light on new targets for NKG2D immunotherapy in cancer treatment.
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Affiliation(s)
- Jiemiao Hu
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 853, Houston, TX, 77030, USA
| | - Xueqing Xia
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 853, Houston, TX, 77030, USA
| | - Qingnan Zhao
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 853, Houston, TX, 77030, USA
| | - Shulin Li
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 853, Houston, TX, 77030, USA.
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Mangiapane G, Parolini I, Conte K, Malfatti MC, Corsi J, Sanchez M, Pietrantoni A, D'Agostino VG, Tell G. Enzymatically active apurinic/apyrimidinic endodeoxyribonuclease 1 is released by mammalian cells through exosomes. J Biol Chem 2021; 296:100569. [PMID: 33753167 PMCID: PMC8080531 DOI: 10.1016/j.jbc.2021.100569] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 03/11/2021] [Accepted: 03/18/2021] [Indexed: 12/11/2022] Open
Abstract
The apurinic/apyrimidinic endodeoxyribonuclease 1 (APE1), the main AP-endonuclease of the DNA base excision repair pathway, is a key molecule of interest to researchers due to its unsuspected roles in different nonrepair activities, such as: i) adaptive cell response to genotoxic stress, ii) regulation of gene expression, and iii) processing of microRNAs, which make it an excellent drug target for cancer treatment. We and others recently demonstrated that APE1 can be secreted in the extracellular environment and that serum APE1 may represent a novel prognostic biomarker in hepatocellular and non-small-cell lung cancers. However, the mechanism by which APE1 is released extracellularly was not described before. Here, using three different approaches for exosomes isolation: commercial kit, nickel-based isolation, and ultracentrifugation methods and various mammalian cell lines, we elucidated the mechanisms responsible for APE1 secretion. We demonstrated that APE1 p37 and p33 forms are actively secreted through extracellular vesicles (EVs), including exosomes from different mammalian cell lines. We then observed that APE1 p33 form is generated by proteasomal-mediated degradation and is enzymatically active in EVs. Finally, we revealed that the p33 form of APE1 accumulates in EVs upon genotoxic treatment by cisplatin and doxorubicin, compounds commonly found in chemotherapy pharmacological treatments. Taken together, these findings provide for the first time evidence that a functional Base Excision Repair protein is delivered through exosomes in response to genotoxic stresses, shedding new light into the complex noncanonical biological functions of APE1 and opening new intriguing perspectives on its role in cancer biology.
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Affiliation(s)
- Giovanna Mangiapane
- Laboratory of Molecular Biology and DNA repair, Department of Medicine (DAME), University of Udine, Udine, Italy
| | - Isabella Parolini
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Kristel Conte
- Laboratory of Molecular Biology and DNA repair, Department of Medicine (DAME), University of Udine, Udine, Italy
| | - Matilde Clarissa Malfatti
- Laboratory of Molecular Biology and DNA repair, Department of Medicine (DAME), University of Udine, Udine, Italy
| | - Jessica Corsi
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | | | | | - Vito G D'Agostino
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Gianluca Tell
- Laboratory of Molecular Biology and DNA repair, Department of Medicine (DAME), University of Udine, Udine, Italy.
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Li S, Shi B, Liu X, An HX. Acetylation and Deacetylation of DNA Repair Proteins in Cancers. Front Oncol 2020; 10:573502. [PMID: 33194676 PMCID: PMC7642810 DOI: 10.3389/fonc.2020.573502] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open
Abstract
Hundreds of DNA repair proteins coordinate together to remove the diverse damages for ensuring the genomic integrity and stability. The repair system is an extensive network mainly encompassing cell cycle arrest, chromatin remodeling, various repair pathways, and new DNA fragment synthesis. Acetylation on DNA repair proteins is a dynamic epigenetic modification orchestrated by lysine acetyltransferases (HATs) and lysine deacetylases (HDACs), which dramatically affects the protein functions through multiple mechanisms, such as regulation of DNA binding ability, protein activity, post-translational modification (PTM) crosstalk, and protein–protein interaction. Accumulating evidence has indicated that the aberrant acetylation of DNA repair proteins contributes to the dysfunction of DNA repair ability, the pathogenesis and progress of cancer, as well as the chemosensitivity of cancer cells. In the present scenario, targeting epigenetic therapy is being considered as a promising method at par with the conventional cancer therapeutic strategies. This present article provides an overview of the recent progress in the functions and mechanisms of acetylation on DNA repair proteins involved in five major repair pathways, which warrants the possibility of regulating acetylation on repair proteins as a therapeutic target in cancers.
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Affiliation(s)
- Shiqin Li
- Department of Medical Oncology, Xiang'an Hospital of Xiamen University, Xiamen, China
| | - Bingbing Shi
- Department of Medical Oncology, Xiang'an Hospital of Xiamen University, Xiamen, China
| | - Xinli Liu
- Department of Medical Oncology, Xiang'an Hospital of Xiamen University, Xiamen, China
| | - Han-Xiang An
- Department of Medical Oncology, Xiang'an Hospital of Xiamen University, Xiamen, China
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Moor N, Vasil’eva I, Lavrik O. Functional Role of N-Terminal Extension of Human AP Endonuclease 1 In Coordination of Base Excision DNA Repair via Protein-Protein Interactions. Int J Mol Sci 2020; 21:ijms21093122. [PMID: 32354179 PMCID: PMC7247576 DOI: 10.3390/ijms21093122] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 02/06/2023] Open
Abstract
Human apurinic/apyrimidinic endonuclease 1 (APE1) has multiple functions in base excision DNA repair (BER) and other cellular processes. Its eukaryote-specific N-terminal extension plays diverse regulatory roles in interaction with different partners. Here, we explored its involvement in interaction with canonical BER proteins. Using fluorescence based-techniques, we compared binding affinities of the full-length and N-terminally truncated forms of APE1 (APE1NΔ35 and APE1NΔ61) for functionally and structurally different DNA polymerase β (Polβ), X-ray repair cross-complementing protein 1 (XRCC1), and poly(adenosine diphosphate (ADP)-ribose) polymerase 1 (PARP1), in the absence and presence of model DNA intermediates. Influence of the N-terminal truncation on binding the AP site-containing DNA was additionally explored. These data suggest that the interaction domain for proteins is basically formed by the conserved catalytic core of APE1. The N-terminal extension being capable of dynamically interacting with the protein and DNA partners is mostly responsible for DNA-dependent modulation of protein–protein interactions. Polβ, XRCC1, and PARP1 were shown to more efficiently regulate the endonuclease activity of the full-length protein than that of APE1NΔ61, further suggesting contribution of the N-terminal extension to BER coordination. Our results advance the understanding of functional roles of eukaryote-specific protein extensions in highly coordinated BER processes.
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Affiliation(s)
- Nina Moor
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (N.M.); (I.V.)
| | - Inna Vasil’eva
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (N.M.); (I.V.)
| | - Olga Lavrik
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (N.M.); (I.V.)
- Novosibirsk State University, 630090 Novosibirsk, Russia
- Correspondence:
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Cleavage of the APE1 N-Terminal Domain in Acute Myeloid Leukemia Cells Is Associated with Proteasomal Activity. Biomolecules 2020; 10:biom10040531. [PMID: 32244430 PMCID: PMC7226146 DOI: 10.3390/biom10040531] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 03/27/2020] [Accepted: 03/30/2020] [Indexed: 02/02/2023] Open
Abstract
Apurinic/apyrimidinic endonuclease 1 (APE1), the main mammalian AP-endonuclease for the resolution of DNA damages through the base excision repair (BER) pathway, acts as a multifunctional protein in different key cellular processes. The signals to ensure temporo-spatial regulation of APE1 towards a specific function are still a matter of debate. Several studies have suggested that post-translational modifications (PTMs) act as dynamic molecular mechanisms for controlling APE1 functionality. Interestingly, the N-terminal region of APE1 is a disordered portion functioning as an interface for protein binding, as an acceptor site for PTMs and as a target of proteolytic cleavage. We previously demonstrated a cytoplasmic accumulation of truncated APE1 in acute myeloid leukemia (AML) cells in association with a mutated form of nucleophosmin having aberrant cytoplasmic localization (NPM1c+). Here, we mapped the proteolytic sites of APE1 in AML cells at Lys31 and Lys32 and showed that substitution of Lys27, 31, 32 and 35 with alanine impairs proteolysis. We found that the loss of the APE1 N-terminal domain in AML cells is dependent on the proteasome, but not on granzyme A/K as described previously. The present work identified the proteasome as a contributing machinery involved in APE1 cleavage in AML cells, suggesting that acetylation can modulate this process.
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Song H, Zeng J, Roychoudhury S, Biswas P, Mohapatra B, Ray S, Dowlatshahi K, Wang J, Band V, Talmon G, Bhakat KK. Targeting Histone Chaperone FACT Complex Overcomes 5-Fluorouracil Resistance in Colon Cancer. Mol Cancer Ther 2019; 19:258-269. [PMID: 31575655 DOI: 10.1158/1535-7163.mct-19-0600] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 08/20/2019] [Accepted: 09/24/2019] [Indexed: 12/31/2022]
Abstract
Fluorouracil (5-FU) remains a first-line chemotherapeutic agent for colorectal cancer. However, a subset of colorectal cancer patients who have defective mismatch-repair (dMMR) pathway show resistance to 5-FU. Here, we demonstrate that the efficacy of 5-FU in dMMR colorectal cancer cells is largely dependent on the DNA base excision repair (BER) pathway. Downregulation of APE1, a key enzyme in the BER pathway, decreases IC50 of 5-FU in dMMR colorectal cancer cells by 10-fold. Furthermore, we discover that the facilitates chromatin transcription (FACT) complex facilitates 5-FU repair in DNA via promoting the recruitment and acetylation of APE1 (AcAPE1) to damage sites in chromatin. Downregulation of FACT affects 5-FU damage repair in DNA and sensitizes dMMR colorectal cancer cells to 5-FU. Targeting the FACT complex with curaxins, a class of small molecules, significantly improves the 5-FU efficacy in dMMR colorectal cancer in vitro (∼50-fold decrease in IC50) and in vivo xenograft models. We show that primary tumor tissues of colorectal cancer patients have higher FACT and AcAPE1 levels compared with adjacent nontumor tissues. Additionally, there is a strong clinical correlation of FACT and AcAPE1 levels with colorectal cancer patients' response to chemotherapy. Together, our study demonstrates that targeting FACT with curaxins is a promising strategy to overcome 5-FU resistance in dMMR colorectal cancer patients.
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Affiliation(s)
- Heyu Song
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska
| | - Jiping Zeng
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska
| | - Shrabasti Roychoudhury
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska
| | - Pranjal Biswas
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska
| | - Bhopal Mohapatra
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska
| | - Sutapa Ray
- Department of Pediatrics, University of Nebraska Medical Center, Omaha, Nebraska
| | - Kayvon Dowlatshahi
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska
| | - Jing Wang
- Eppley Institute for Cancer Research, University of Nebraska Medical Center, Omaha, Nebraska
| | - Vimla Band
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska.,Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska
| | - Geoffrey Talmon
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska
| | - Kishor K Bhakat
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska. .,Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska
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Malfatti MC, Gerratana L, Dalla E, Isola M, Damante G, Di Loreto C, Puglisi F, Tell G. APE1 and NPM1 protect cancer cells from platinum compounds cytotoxicity and their expression pattern has a prognostic value in TNBC. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2019; 38:309. [PMID: 31307523 PMCID: PMC6631760 DOI: 10.1186/s13046-019-1294-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 06/25/2019] [Indexed: 02/07/2023]
Abstract
Background Triple negative breast cancer (TNBC) is a breast cancer subgroup characterized by a lack of hormone receptors’ expression and no HER2 overexpression. These molecular features both drastically reduce treatment options and confer poor prognosis. Platinum (Pt)-salts are being investigated as a new therapeutic strategy. The base excision repair (BER) pathway is important for resistance to Pt-based therapies. Overexpression of APE1, a pivotal enzyme of the BER pathway, as well as the expression of NPM1, a functional regulator of APE1, are associated with poor outcome and resistance to Pt-based therapies. Methods We evaluated the role of NPM1, APE1 and altered NPM1/APE1 interaction in the response to Pt-salts treatment in different cell lines: APE1 knockout (KO) cells, NPM1 KO cells, cell line models having an altered APE1/NPM1 interaction and HCC70 and HCC1937 TNBC cell lines, having different levels of APE1/NPM1. We evaluated the TNBC cells response to new chemotherapeutic small molecules targeting the endonuclease activity of APE1 or the APE1/NPM1 interaction, in combination with Pt-salts treatments. Expression levels’ correlation between APE1 and NPM1 and their impact on prognosis was analyzed in a cohort of TNBC patients through immunohistochemistry. Bioinformatics analysis, using TCGA datasets, was performed to predict a molecular signature of cancers based on APE1 and NPM1 expression. Results APE1 and NPM1, and their interaction as well, protect from the cytotoxicity induced by Pt-salts treatment. HCC1937 cells, having higher levels of APE1/NPM1 proteins, are more resistant to Pt-salts treatment compared to the HCC70 cells. A sensitization effect by APE1 inhibitors to Pt-compounds was observed. The association of NPM1/APE1 with cancer gene signatures highlighted alterations concerning cell-cycle dependent proteins. Conclusions APE1 and NPM1 protect cancer cells from Pt-compounds cytotoxicity, suggesting a possible improvement of the activity of Pt-based therapy for TNBC, using the NPM1 and APE1 proteins as secondary therapeutic targets. Based on positive or negative correlation with APE1 and NPM1 gene expression levels, we finally propose several TNBC gene signatures that should deserve further attention for their potential impact on TNBC precision medicine approaches. Electronic supplementary material The online version of this article (10.1186/s13046-019-1294-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Lorenzo Gerratana
- Department of Medicine (DAME), University of Udine, Piazzale M. Kolbe 4, 33100, Udine, Italy.,Department of Oncology, ASUI Udine SMM University Hospital Udine, Udine, Italy
| | - Emiliano Dalla
- Department of Medicine (DAME), University of Udine, Piazzale M. Kolbe 4, 33100, Udine, Italy
| | - Miriam Isola
- Department of Medicine (DAME), University of Udine, Piazzale M. Kolbe 4, 33100, Udine, Italy
| | - Giuseppe Damante
- Department of Medicine (DAME), University of Udine, Piazzale M. Kolbe 4, 33100, Udine, Italy
| | - Carla Di Loreto
- Department of Medicine (DAME), University of Udine, Piazzale M. Kolbe 4, 33100, Udine, Italy.,Department of Pathology, ASUI Udine SMM University Hospital Udine, Udine, Italy
| | - Fabio Puglisi
- Department of Medicine (DAME), University of Udine, Piazzale M. Kolbe 4, 33100, Udine, Italy.,Department of Medical Oncology, Centro di Riferimento Oncologico (CRO), IRCCS, Aviano, Italy
| | - Gianluca Tell
- Department of Medicine (DAME), University of Udine, Piazzale M. Kolbe 4, 33100, Udine, Italy.
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14
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The Molecular Chaperone Heat Shock Protein 70 Controls Liver Cancer Initiation and Progression by Regulating Adaptive DNA Damage and Mitogen-Activated Protein Kinase/Extracellular Signal-Regulated Kinase Signaling Pathways. Mol Cell Biol 2019; 39:MCB.00391-18. [PMID: 30745413 DOI: 10.1128/mcb.00391-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 02/04/2019] [Indexed: 02/06/2023] Open
Abstract
Delineating the mechanisms that drive hepatic injury and hepatocellular carcinoma (HCC) progression is critical for development of novel treatments for recurrent and advanced HCC but also for the development of diagnostic and preventive strategies. Heat shock protein 70 (HSP70) acts in concert with several cochaperones and nucleotide exchange factors and plays an essential role in protein quality control that increases survival by protecting cells against environmental stressors. Specifically, the HSP70-mediated response has been implicated in the pathogenesis of cancer, but the specific mechanisms by which HSP70 may support malignant cell transformation remains to be fully elucidated. Here, we show that genetic ablation of HSP70 markedly impairs HCC initiation and progression by distinct but overlapping pathways. This includes the potentiation of the carcinogen-induced DNA damage response, at the tumor initiation stage, to increase the p53-dependent surveillance response leading to the cell cycle exit or death of genomically damaged differentiated pericentral hepatocytes, and this may also prevent their conversion into more proliferating HCC progenitor cells. Subsequently, activation of a mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) negative feedback pathway diminishes oncogenic signals, thereby attenuating premalignant cell transformation and tumor progression. Modulation of HSP70 function may be a strategy for interfering with oncogenic signals driving liver cell transformation and tumor progression, thus providing an opportunity for human cancer control.
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15
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Serum AP-endonuclease 1 (sAPE1) as novel biomarker for hepatocellular carcinoma. Oncotarget 2019; 10:383-394. [PMID: 30719231 PMCID: PMC6349448 DOI: 10.18632/oncotarget.26555] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 12/27/2018] [Indexed: 12/24/2022] Open
Abstract
Late diagnosis for Hepatocellular Carcinoma (HCC) remains one of the leading causes for the high mortality rate. The apurinic/apyrimidinic endonuclease 1 (APE1), an essential member of the base excision DNA repair (BER) pathway, contributes to cell response to oxidative stress and has other non-repair activities. In this study, we evaluate the role of serum APE1 (sAPE1) as a new diagnostic biomarker and we investigate the biological role for extracellular APE1 in HCC. sAPE1 level was quantified in 99 HCC patients, 50 non-HCC cirrhotic and 100 healthy controls. The expression level was significantly high in HCC (75.8 [67.3–87.9] pg/mL) compared to cirrhosis (29.8 [18.3–36.5] pg/mL] and controls (10.8 [7.5–13.2] pg/mL) (p < 0.001). The sAPE1 level corresponded with its protein expression in HCC tissue. sAPE1 had high diagnostic accuracy to differentiate HCC from cirrhotic (AUC = 0.87, sensitivity 88%, specificity 71%, cut-off of 36.3 pg/mL) and healthy subjects (AUC 0.98, sensibility 98% and specificity 83%, cut-off of 19.0 pg/mL). Recombinant APE1, exogenously added to JHH6 cells, significantly promotes IL-6 and IL-8 expression, suggesting a role of sAPE1 as a paracrine pro-inflammatory molecule, which may modulate the inflammatory status in cancer microenvironment. We described herein, for the first time to our knowledge, that sAPE1 might be considered as a promising diagnostic biomarker for HCC.
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16
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Burra S, Marasco D, Malfatti MC, Antoniali G, Virgilio A, Esposito V, Demple B, Galeone A, Tell G. Human AP-endonuclease (Ape1) activity on telomeric G4 structures is modulated by acetylatable lysine residues in the N-terminal sequence. DNA Repair (Amst) 2018; 73:129-143. [PMID: 30509560 DOI: 10.1016/j.dnarep.2018.11.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/21/2018] [Accepted: 11/21/2018] [Indexed: 02/08/2023]
Abstract
Loss of telomeres stability is a hallmark of cancer cells. Exposed telomeres are prone to aberrant end-joining reactions leading to chromosomal fusions and translocations. Human telomeres contain repeated TTAGGG elements, in which the 3' exposed strand may adopt a G-quadruplex (G4) structure. The guanine-rich regions of telomeres are hotspots for oxidation forming 8-oxoguanine, a lesion that is handled by the base excision repair (BER) pathway. One key player of this pathway is Ape1, the main human endonuclease processing abasic sites. Recent evidences showed an important role for Ape1 in telomeric physiology, but the molecular details regulating Ape1 enzymatic activities on G4-telomeric sequences are lacking. Through a combination of in vitro assays, we demonstrate that Ape1 can bind and process different G4 structures and that this interaction involves specific acetylatable lysine residues (i.e. K27/31/32/35) present in the unstructured N-terminal sequence of the protein. The cleavage of an abasic site located in a G4 structure by Ape1 depends on the DNA conformation or the position of the lesion and on electrostatic interactions between the protein and the nucleic acids. Moreover, Ape1 mutants mimicking the acetylated protein display increased cleavage activity for abasic sites. We found that nucleophosmin (NPM1), which binds the N-terminal sequence of Ape1, plays a role in modulating telomere length and Ape1 activity at abasic G4 structures. Thus, the Ape1 N-terminal sequence is an important relay site for regulating the enzyme's activity on G4-telomeric sequences, and specific acetylatable lysine residues constitute key regulatory sites of Ape1 enzymatic activity dynamics at telomeres.
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Affiliation(s)
- Silvia Burra
- Laboratory of Molecular Biology and DNA Repair, Department of Medicine (DAME), University of Udine, Udine, Italy
| | - Daniela Marasco
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131, Naples, Italy
| | - Matilde Clarissa Malfatti
- Laboratory of Molecular Biology and DNA Repair, Department of Medicine (DAME), University of Udine, Udine, Italy
| | - Giulia Antoniali
- Laboratory of Molecular Biology and DNA Repair, Department of Medicine (DAME), University of Udine, Udine, Italy
| | - Antonella Virgilio
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131, Naples, Italy
| | - Veronica Esposito
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131, Naples, Italy
| | - Bruce Demple
- Department of Pharmacological Sciences, Stony Brook University, School of Medicine, Stony Brook, NY, 11794-8651, USA
| | - Aldo Galeone
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131, Naples, Italy
| | - Gianluca Tell
- Laboratory of Molecular Biology and DNA Repair, Department of Medicine (DAME), University of Udine, Udine, Italy.
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17
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Dutto I, Scalera C, Prosperi E. CREBBP and p300 lysine acetyl transferases in the DNA damage response. Cell Mol Life Sci 2018; 75:1325-1338. [PMID: 29170789 PMCID: PMC11105205 DOI: 10.1007/s00018-017-2717-4] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 11/16/2017] [Accepted: 11/20/2017] [Indexed: 12/21/2022]
Abstract
The CREB-binding protein (CREBBP, or in short CBP) and p300 are lysine (K) acetyl transferases (KAT) belonging to the KAT3 family of proteins known to modify histones, as well as non-histone proteins, thereby regulating chromatin accessibility and transcription. Previous studies have indicated a tumor suppressor function for these enzymes. Recently, they have been found to acetylate key factors involved in DNA replication, and in different DNA repair processes, such as base excision repair, nucleotide excision repair, and non-homologous end joining. The growing list of CBP/p300 substrates now includes factors involved in DNA damage signaling, and in other pathways of the DNA damage response (DDR). This review will focus on the role of CBP and p300 in the acetylation of DDR proteins, and will discuss how this post-translational modification influences their functions at different levels, including catalytic activity, DNA binding, nuclear localization, and protein turnover. In addition, we will exemplify how these functions may be necessary to efficiently coordinate the spatio-temporal response to DNA damage. CBP and p300 may contribute to genome stability by fine-tuning the functions of DNA damage signaling and DNA repair factors, thereby expanding their role as tumor suppressors.
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Affiliation(s)
- Ilaria Dutto
- Istituto di Genetica Molecolare del CNR, Via Abbiategrasso 207, 27100, Pavia, Italy
- IRB, Carrer Baldiri Reixac 10, 08028, Barcelona, Spain
| | - Claudia Scalera
- Istituto di Genetica Molecolare del CNR, Via Abbiategrasso 207, 27100, Pavia, Italy
| | - Ennio Prosperi
- Istituto di Genetica Molecolare del CNR, Via Abbiategrasso 207, 27100, Pavia, Italy.
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18
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Sengupta S, Mantha AK, Song H, Roychoudhury S, Nath S, Ray S, Bhakat KK. Elevated level of acetylation of APE1 in tumor cells modulates DNA damage repair. Oncotarget 2018; 7:75197-75209. [PMID: 27655688 PMCID: PMC5342734 DOI: 10.18632/oncotarget.12113] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 09/02/2016] [Indexed: 12/20/2022] Open
Abstract
Apurinic/apyrimidinic (AP) sites are frequently generated in the genome by spontaneous depurination/depyrimidination or after removal of oxidized/modified bases by DNA glycosylases during the base excision repair (BER) pathway. Unrepaired AP sites are mutagenic and block DNA replication and transcription. The primary enzyme to repair AP sites in mammalian cells is AP endonuclease (APE1), which plays a key role in this repair pathway. Although overexpression of APE1 in diverse cancer types and its association with chemotherapeutic resistance are well documented, alteration of posttranslational modification of APE1 and modulation of its functions during tumorigenesis are largely unknown. Here, we show that both classical histone deacetylase HDAC1 and NAD+-dependent deacetylase SIRT1 regulate acetylation level of APE1 and acetylation of APE1 enhances its AP-endonuclease activity both in vitro and in cells. Modulation of APE1 acetylation level in cells alters AP site repair capacity of the cell extracts in vitro. Primary tumor tissues of diverse cancer types have higher level of acetylated APE1 (AcAPE1) compared to adjacent non-tumor tissue and exhibit enhanced AP site repair capacity. Importantly, in the absence of APE1 acetylation, cells accumulate AP sites in the genome and show increased sensitivity to DNA damaging agents. Together, our study demonstrates that elevation of acetylation level of APE1 in tumor could be a novel mechanism by which cells handle the elevated levels of DNA damages in response to genotoxic stress and maintain sustained proliferation.
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Affiliation(s)
- Shiladitya Sengupta
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX 77030 , USA
| | - Anil K Mantha
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Center for Animal Sciences, School of Basic and Applied Sciences, Central University of Punjab, Bathinda 151001, Punjab, India
| | - Heyu Song
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Shrabasti Roychoudhury
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Somsubhra Nath
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA.,Molecular Biology Research & Diagnostic Laboratory, Saroj Gupta Cancer Centre & Research Institute, Kolkata 700063, India
| | - Sutapa Ray
- Department of Pediatrics, Hematology/Oncology Division, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Kishor K Bhakat
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA.,Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
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19
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Antoniali G, Serra F, Lirussi L, Tanaka M, D'Ambrosio C, Zhang S, Radovic S, Dalla E, Ciani Y, Scaloni A, Li M, Piazza S, Tell G. Mammalian APE1 controls miRNA processing and its interactome is linked to cancer RNA metabolism. Nat Commun 2017; 8:797. [PMID: 28986522 PMCID: PMC5630600 DOI: 10.1038/s41467-017-00842-8] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 07/28/2017] [Indexed: 01/31/2023] Open
Abstract
Mammalian apurinic/apyrimidinic endonuclease 1 is a DNA repair enzyme involved in genome stability and expression of genes involved in oxidative stress responses, tumor progression and chemoresistance. However, the molecular mechanisms underlying the role of apurinic/apyrimidinic endonuclease 1 in these processes are still unclear. Recent findings point to a novel role of apurinic/apyrimidinic endonuclease 1 in RNA metabolism. Through the characterization of the interactomes of apurinic/apyrimidinic endonuclease 1 with RNA and other proteins, we demonstrate here a role for apurinic/apyrimidinic endonuclease 1 in pri-miRNA processing and stability via association with the DROSHA-processing complex during genotoxic stress. We also show that endonuclease activity of apurinic/apyrimidinic endonuclease 1 is required for the processing of miR-221/222 in regulating expression of the tumor suppressor PTEN. Analysis of a cohort of different cancers supports the relevance of our findings for tumor biology. We also show that apurinic/apyrimidinic endonuclease 1 participates in RNA-interactomes and protein-interactomes involved in cancer development, thus indicating an unsuspected post-transcriptional effect on cancer genes. APE1 plays an important role in the cellular response to oxidative stress, and mutations are linked to tumor progression and chemoresistance. Here, the authors characterize the interactions of APE1 with RNA and demonstrate a role in microRNA processing.
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Affiliation(s)
- Giulia Antoniali
- Department of Medicine, Laboratory of Molecular Biology and DNA repair, University of Udine, p.le M. Kolbe 4, Udine, 33100, Italy
| | - Fabrizio Serra
- Department of Medicine, Laboratory of Molecular Biology and DNA repair, University of Udine, p.le M. Kolbe 4, Udine, 33100, Italy.,Clinical and Experimental Onco-Hematology Unit, Centro di Riferimento Oncologico, I.R.C.C.S., via Franco Gallini 2, Aviano (PN), 33081, Italy
| | - Lisa Lirussi
- Department of Medicine, Laboratory of Molecular Biology and DNA repair, University of Udine, p.le M. Kolbe 4, Udine, 33100, Italy.,Department of Clinical Molecular Biology, University of Oslo and Akershus University Hospital, Sykehusveien 27, Nordbyhagen, 1474, Norway
| | - Mikiei Tanaka
- Laboratory of Biochemistry, National Heart Lung and Blood Institute, National Institutes of Health, 50 South Drive, MSC-8012, Bethesda, MD, 20892-8012, USA
| | - Chiara D'Ambrosio
- Proteomics and Mass Spectrometry Laboratory, Institute for the Animal Production System in the Mediterranean Environment (ISPAAM) National Research Council (CNR) of Italy, via Argine 1085, Naples, 80147, Italy
| | - Shiheng Zhang
- Cancer Center of Daping Hospital, Third Military Medical University, Chongqing, 400042, China
| | | | - Emiliano Dalla
- Laboratorio Nazionale CIB, Area Science Park Padriciano, Trieste, 34149, Italy
| | - Yari Ciani
- Laboratorio Nazionale CIB, Area Science Park Padriciano, Trieste, 34149, Italy
| | - Andrea Scaloni
- Proteomics and Mass Spectrometry Laboratory, Institute for the Animal Production System in the Mediterranean Environment (ISPAAM) National Research Council (CNR) of Italy, via Argine 1085, Naples, 80147, Italy
| | - Mengxia Li
- Cancer Center of Daping Hospital, Third Military Medical University, Chongqing, 400042, China.
| | - Silvano Piazza
- Laboratorio Nazionale CIB, Area Science Park Padriciano, Trieste, 34149, Italy. .,Bioinformatics Core Facility, Centre for Integrative Biology, CIBIO, University of Trento, via Sommarive 18, Povo, Trento, TN, 38123, Italy.
| | - Gianluca Tell
- Department of Medicine, Laboratory of Molecular Biology and DNA repair, University of Udine, p.le M. Kolbe 4, Udine, 33100, Italy.
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20
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The extracellular role of DNA damage repair protein APE1 in regulation of IL-6 expression. Cell Signal 2017; 39:18-31. [PMID: 28751279 DOI: 10.1016/j.cellsig.2017.07.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 07/21/2017] [Accepted: 07/23/2017] [Indexed: 11/20/2022]
Abstract
The human apurinic/apyrimidinic endonuclease 1 (APE1) is a pleiotropic nuclear protein with roles in DNA base excision repair pathway as well as in regulation of transcription. Recently, the presence of extracellular plasma APE1 was reported in endotoxemic rats. However, the biological significance and the extracellular function of APE1 remain unclear. In this study, we found that monocytes secrete APE1 upon inflammatory challenges. Challenging the monocytic cells with extracellular APE1 resulted in the increased expression and secretion of the pro-inflammatory cytokine IL-6. Additionally, the extracellular APE1 treatment activated the transcription factor NF-κB, followed by its increased occupancy at the IL-6 promoter, resulting in the induction of IL-6 expression. APE1-induced IL-6 further served to elicit autocrine and paracrine cellular responses. Moreover, the extracellular IL-6 promoted the secretion of APE1, thus indicating a functional feedforward loop in this pathway. Furthermore, we show that APE1 is secreted through extracellular vesicles formation via endosomal sorting complex required for transport (ESCRT)-dependent pathway. Together, our study demonstrates a novel role of extracellular APE1 in IL-6-dependent cellular responses.
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21
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Human Apurinic/Apyrimidinic Endonuclease (APE1) Is Acetylated at DNA Damage Sites in Chromatin, and Acetylation Modulates Its DNA Repair Activity. Mol Cell Biol 2017; 37:MCB.00401-16. [PMID: 27994014 PMCID: PMC5335514 DOI: 10.1128/mcb.00401-16] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 12/14/2016] [Indexed: 11/20/2022] Open
Abstract
Apurinic/apyrimidinic (AP) sites, the most frequently formed DNA lesions in the genome, inhibit transcription and block replication. The primary enzyme that repairs AP sites in mammalian cells is the AP endonuclease (APE1), which functions through the base excision repair (BER) pathway. Although the mechanism by which APE1 repairs AP sites in vitro has been extensively investigated, it is largely unknown how APE1 repairs AP sites in cells. Here, we show that APE1 is acetylated (AcAPE1) after binding to the AP sites in chromatin and that AcAPE1 is exclusively present on chromatin throughout the cell cycle. Positive charges of acetylable lysine residues in the N-terminal domain of APE1 are essential for chromatin association. Acetylation-mediated neutralization of the positive charges of the lysine residues in the N-terminal domain of APE1 induces a conformational change; this in turn enhances the AP endonuclease activity of APE1. In the absence of APE1 acetylation, cells accumulated AP sites in the genome and showed higher sensitivity to DNA-damaging agents. Thus, mammalian cells, unlike Saccharomyces cerevisiae or Escherichia coli cells, require acetylation of APE1 for the efficient repair of AP sites and base damage in the genome. Our study reveals that APE1 acetylation is an integral part of the BER pathway for maintaining genomic integrity.
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22
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Sandomenico A, Focà A, Sanguigno L, Caporale A, Focà G, Pignalosa A, Corvino G, Caragnano A, Beltrami AP, Antoniali G, Tell G, Leonardi A, Ruvo M. Monoclonal antibodies against pools of mono- and polyacetylated peptides selectively recognize acetylated lysines within the context of the original antigen. MAbs 2016; 8:1575-1589. [PMID: 27560983 DOI: 10.1080/19420862.2016.1225643] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Post-translational modifications (PTMs) strongly influence the structure and function of proteins. Lysine side chain acetylation is one of the most widespread PTMs, and it plays a major role in several physiological and pathological mechanisms. Protein acetylation may be detected by mass spectrometry (MS), but the use of monoclonal antibodies (mAbs) is a useful and cheaper option. Here, we explored the feasibility of generating mAbs against single or multiple acetylations within the context of a specific sequence. As a model, we used the unstructured N-terminal domain of APE1, which is acetylated on Lys27, Lys31, Lys32 and Lys35. As immunogen, we used a peptide mixture containing all combinations of single or multi-acetylated variants encompassing the 24-39 protein region. Targeted screening of the resulting clones yielded mAbs that bind with high affinity to only the acetylated APE1 peptides and the acetylated protein. No binding was seen with the non-acetylated variant or unrelated acetylated peptides and proteins, suggesting a high specificity for the APE1 acetylated molecules. MAbs could not finely discriminate between the differently acetylated variants; however, they specifically bound the acetylated protein in mammalian cell extracts and in intact cells and tissue slices from both breast cancers and from a patient affected by idiopathic dilated cardiomyopathy. The data suggest that our approach is a rapid and cost-effective method to generate mAbs against specific proteins modified by multiple acetylations or other PTMs.
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Affiliation(s)
- Annamaria Sandomenico
- a Istituto di Biostrutture e Bioimmagini , Consiglio Nazionale delle Ricerche (IBB-CNR) , Napoli , Italy
| | - Annalia Focà
- a Istituto di Biostrutture e Bioimmagini , Consiglio Nazionale delle Ricerche (IBB-CNR) , Napoli , Italy
| | | | - Andrea Caporale
- c Centro Interuniversitario di Ricerca sui Peptidi Bioattivi (CIRPeB) , Napoli , Italy
| | - Giuseppina Focà
- a Istituto di Biostrutture e Bioimmagini , Consiglio Nazionale delle Ricerche (IBB-CNR) , Napoli , Italy
| | - Angelica Pignalosa
- a Istituto di Biostrutture e Bioimmagini , Consiglio Nazionale delle Ricerche (IBB-CNR) , Napoli , Italy
| | | | - Angela Caragnano
- d University of Udine , Department of Medical and Biological Sciences , Udine , Italy
| | | | - Giulia Antoniali
- d University of Udine , Department of Medical and Biological Sciences , Udine , Italy
| | - Gianluca Tell
- d University of Udine , Department of Medical and Biological Sciences , Udine , Italy
| | - Antonio Leonardi
- e University of Napoli "Federico II," Department of Molecular Medicine and Medical Biotechnology , Napoli , Italy
| | - Menotti Ruvo
- a Istituto di Biostrutture e Bioimmagini , Consiglio Nazionale delle Ricerche (IBB-CNR) , Napoli , Italy
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23
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Dai N, Qing Y, Cun Y, Zhong Z, Li C, Zhang S, Shan J, Yang X, Dai X, Cheng Y, Xiao H, Xu C, Li M, Wang D. miR-513a-5p regulates radiosensitivity of osteosarcoma by targeting human apurinic/apyrimidinic endonuclease. Oncotarget 2016; 9:25414-25426. [PMID: 29875998 PMCID: PMC5986632 DOI: 10.18632/oncotarget.11003] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 06/01/2016] [Indexed: 11/30/2022] Open
Abstract
Radiotherapy in osteosarcoma patients is problematic due to radioresistance; therefore, understanding the mechanism of radioresistance is integral to providing effective radiotherapeutic regimens for osteosarcoma. We now report the activity of an miRNA, miR-513a-5p, in stimulating radiosensitivity of osteosarcoma cells in vitro and in vivo. MiR-513a-5p expression is decreased in osteosarcoma tissue from patients and cultured osteosarcoma cell lines. However, exogenous re-expression of this miRNA in osteosarcoma cell lines, including HOS, U2OS and 9901, can induce sensitization to ionizing radiation. We also confirm that miR-513a-5p suppresses APE1 expression, and that both the redox and DNA repair activity of APE1 were decreased in miR-513a-5p expressing cell lines. By suppressing APE1, miR-513a-5p induces the DNA damage response which stimulates apoptosis after irradiation. Our report establishes miR-513a-5p as a radiosensitizing miRNA and identifies its activity in the suppression of APE1, which could directly lead to radiosensitization.
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Affiliation(s)
- Nan Dai
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China
| | - Yi Qing
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China
| | - Yanping Cun
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China.,Department of Neurosurgery, Wuhan General Hospital of Guangzhou Military Command, Wuhan, 430070, P.R. China
| | - Zhaoyang Zhong
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China
| | - Chongyi Li
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China
| | - Shiheng Zhang
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China
| | - Jinlu Shan
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China
| | - Xiao Yang
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China
| | - Xiaoyan Dai
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China
| | - Yi Cheng
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China
| | - He Xiao
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China
| | - Chengxiong Xu
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China
| | - Mengxia Li
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China
| | - Dong Wang
- Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, P.R. China
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