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Sarre A, Stelter M, Rollo F, De Bonis S, Seck A, Hognon C, Ravanat JL, Monari A, Dehez F, Moe E, Timmins J. The three Endonuclease III variants of Deinococcus radiodurans possess distinct and complementary DNA repair activities. DNA Repair (Amst) 2019; 78:45-59. [DOI: 10.1016/j.dnarep.2019.03.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/26/2019] [Accepted: 03/27/2019] [Indexed: 11/26/2022]
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Martinez-Velez N, Marigil M, García-Moure M, Gonzalez-Huarriz M, Aristu JJ, Ramos-García LI, Tejada S, Díez-Valle R, Patiño-García A, Becher OJ, Gomez-Manzano C, Fueyo J, Alonso MM. Delta-24-RGD combined with radiotherapy exerts a potent antitumor effect in diffuse intrinsic pontine glioma and pediatric high grade glioma models. Acta Neuropathol Commun 2019; 7:64. [PMID: 31036068 PMCID: PMC6487528 DOI: 10.1186/s40478-019-0714-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Accepted: 04/02/2019] [Indexed: 01/17/2023] Open
Abstract
Pediatric high grade gliomas (pHGG), including diffuse intrinsic pontine gliomas (DIPGs), are aggressive tumors with a dismal outcome. Radiotherapy (RT) is part of the standard of care of these tumors; however, radiotherapy only leads to a transient clinical improvement. Delta-24-RGD is a genetically engineered tumor-selective adenovirus that has shown safety and clinical efficacy in adults with recurrent gliomas. In this work, we evaluated the feasibility, safety and therapeutic efficacy of Delta-24-RGD in combination with radiotherapy in pHGGs and DIPGs models. Our results showed that the combination of Delta-24-RGD with radiotherapy was feasible and resulted in a synergistic anti-glioma effect in vitro and in vivo in pHGG and DIPG models. Interestingly, Delta-24-RGD treatment led to the downregulation of relevant DNA damage repair proteins, further sensitizing tumors cells to the effect of radiotherapy. Additionally, Delta-24-RGD/radiotherapy treatment significantly increased the trafficking of immune cells (CD3, CD4+ and CD8+) to the tumor niche compared with single treatments. In summary, administration of the Delta-24-RGD/radiotherapy combination to pHGG and DIPG models is safe and significantly increases the overall survival of mice bearing these tumors. Our data offer a rationale for the combination Delta-24-RGD/radiotherapy as a therapeutic option for children with these tumors. SIGNIFICANCE: Delta-24-RGD/radiotherapy administration is safe and significantly increases the survival of treated mice. These positive data underscore the urge to translate this approach to the clinical treatment of children with pHGG and DIPGs.
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Heckler MM, Zeleke TZ, Divekar SD, Fernandez AI, Tiek DM, Woodrick J, Farzanegan A, Roy R, Üren A, Mueller SC, Riggins RB. Antimitotic activity of DY131 and the estrogen-related receptor beta 2 (ERRβ2) splice variant in breast cancer. Oncotarget 2018; 7:47201-47220. [PMID: 27363015 PMCID: PMC5216935 DOI: 10.18632/oncotarget.9719] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 05/19/2016] [Indexed: 01/09/2023] Open
Abstract
Breast cancer remains a leading cause of cancer-related death in women, and triple negative breast cancer (TNBC) lacks clinically actionable therapeutic targets. Death in mitosis is a tumor suppressive mechanism that occurs in cancer cells experiencing a defective M phase. The orphan estrogen-related receptor beta (ERRβ) is a key reprogramming factor in murine embryonic and induced pluripotent stem cells. In primates, ERRβ is alternatively spliced to produce several receptor isoforms. In cellular models of glioblastoma, short form (ERRβsf) and beta2 (ERRβ2) splice variants differentially regulate cell cycle progression in response to the synthetic agonist DY131, with ERRβ2 driving arrest in G2/M.The goals of the present study are to determine the cellular function(s) of ligand-activated ERRβ splice variants in breast cancer and evaluate the potential of DY131 to serve as an antimitotic agent, particularly in TNBC. DY131 inhibits growth in a diverse panel of breast cancer cell lines, causing cell death that involves the p38 stress kinase pathway and a bimodal cell cycle arrest. ERRβ2 facilitates the block in G2/M, and DY131 delays progression from prophase to anaphase. Finally, ERRβ2 localizes to centrosomes and DY131 causes mitotic spindle defects. Targeting ERRβ2 may therefore be a promising therapeutic strategy in breast cancer.
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Affiliation(s)
- Mary M Heckler
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Tizita Zewde Zeleke
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Shailaja D Divekar
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Aileen I Fernandez
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Deanna M Tiek
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Jordan Woodrick
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Alexander Farzanegan
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Rabindra Roy
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Aykut Üren
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Susette C Mueller
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Rebecca B Riggins
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
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Depletion of tyrosyl DNA phosphodiesterase 2 activity enhances etoposide-mediated double-strand break formation and cell killing. DNA Repair (Amst) 2016; 43:38-47. [DOI: 10.1016/j.dnarep.2016.04.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 11/20/2022]
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Kuznetsov NA, Kiryutin AS, Kuznetsova AA, Panov MS, Barsukova MO, Yurkovskaya AV, Fedorova OS. The formation of catalytically competent enzyme-substrate complex is not a bottleneck in lesion excision by human alkyladenine DNA glycosylase. J Biomol Struct Dyn 2016; 35:950-967. [PMID: 27025273 DOI: 10.1080/07391102.2016.1171800] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Human alkyladenine DNA glycosylase (AAG) protects DNA from alkylated and deaminated purine lesions. AAG flips out the damaged nucleotide from the double helix of DNA and catalyzes the hydrolysis of the N-glycosidic bond to release the damaged base. To understand better, how the step of nucleotide eversion influences the overall catalytic process, we performed a pre-steady-state kinetic analysis of AAG interaction with specific DNA-substrates, 13-base pair duplexes containing in the 7th position 1-N6-ethenoadenine (εA), hypoxanthine (Hx), and the stable product analogue tetrahydrofuran (F). The combination of the fluorescence of tryptophan, 2-aminopurine, and 1-N6-ethenoadenine was used to record conformational changes of the enzyme and DNA during the processes of DNA lesion recognition, damaged base eversion, excision of the N-glycosidic bond, and product release. The thermal stability of the duplexes characterized by the temperature of melting, Tm, and the rates of spontaneous opening of individual nucleotide base pairs were determined by NMR spectroscopy. The data show that the relative thermal stability of duplexes containing a particular base pair in position 7, (Tm(F/T) < Tm(εA/T) < Tm(Hx/T) < Tm(A/T)) correlates with the rate of reversible spontaneous opening of the base pair. However, in contrast to that, the catalytic lesion excision rate is two orders of magnitude higher for Hx-containing substrates than for substrates containing εA, proving that catalytic activity is not correlated with the stability of the damaged base pair. Our study reveals that the formation of the catalytically competent enzyme-substrate complex is not the bottleneck controlling the catalytic activity of AAG.
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Affiliation(s)
- N A Kuznetsov
- a Institute of Chemical Biology and Fundamental Medicine , Lavrentyev Ave. 8, Novosibirsk 630090 , Russia.,c Department of Natural Sciences , Novosibirsk State University , Pirogova St. 2, Novosibirsk 630090 , Russia
| | - A S Kiryutin
- b International Tomography Center SB RAS, Institutskaya 3a , Novosibirsk 630090 , Russia.,c Department of Natural Sciences , Novosibirsk State University , Pirogova St. 2, Novosibirsk 630090 , Russia
| | - A A Kuznetsova
- a Institute of Chemical Biology and Fundamental Medicine , Lavrentyev Ave. 8, Novosibirsk 630090 , Russia
| | - M S Panov
- b International Tomography Center SB RAS, Institutskaya 3a , Novosibirsk 630090 , Russia.,c Department of Natural Sciences , Novosibirsk State University , Pirogova St. 2, Novosibirsk 630090 , Russia
| | - M O Barsukova
- c Department of Natural Sciences , Novosibirsk State University , Pirogova St. 2, Novosibirsk 630090 , Russia
| | - A V Yurkovskaya
- b International Tomography Center SB RAS, Institutskaya 3a , Novosibirsk 630090 , Russia.,c Department of Natural Sciences , Novosibirsk State University , Pirogova St. 2, Novosibirsk 630090 , Russia
| | - O S Fedorova
- a Institute of Chemical Biology and Fundamental Medicine , Lavrentyev Ave. 8, Novosibirsk 630090 , Russia
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Woodrick J, Gupta S, Khatkar P, Dave K, Levashova D, Choudhury S, Elias H, Saha T, Mueller S, Roy R. A novel method for monitoring functional lesion-specific recruitment of repair proteins in live cells. Mutat Res 2015; 775:48-58. [PMID: 25879709 DOI: 10.1016/j.mrfmmm.2015.03.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 03/17/2015] [Accepted: 03/27/2015] [Indexed: 02/07/2023]
Abstract
DNA-protein relationships have been studied by numerous methods, but a particular gap in methodology lies in the study of DNA adduct-specific interactions with proteins in vivo, which particularly affects the field of DNA repair. Using the repair of a well-characterized and ubiquitous adduct, the abasic (AP) site, as a model, we have developed a comprehensive method of monitoring DNA lesion-specific recruitment of proteins in vivo over time. We utilized a surrogate system in which a Cy3-labeled plasmid containing a single AP-site was transfected into cells, and the interaction of the labeled DNA with BER enzymes, including APE1, Polβ, LIG1, and FEN1, was monitored by immunofluorescent staining of the enzymes by Alexafluor-488-conjugated secondary antibody. The recruitment of enzymes was characterized by quantification of Cy3-Alexafluor-488 co-localization. To validate the microscopy-based method, repair of the transfected AP-site DNA was also quantified at various time points post-transfection using a real time PCR-based method. Notably, the recruitment time kinetics for each enzyme were consistent with AP-site repair time kinetics. This microscopy-based methodology is reliable in detecting the recruitment of proteins to specific DNA substrates and can be extended to study other in vivo DNA-protein relationships in any DNA sequence and in the context of any DNA structure in transfectable proliferating or quiescent cells. The method may be applied to a variety of disciplines of nucleic acid transaction pathways, including repair, replication, transcription, and recombination.
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Affiliation(s)
- Jordan Woodrick
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Suhani Gupta
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Pooja Khatkar
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Kalpana Dave
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Darya Levashova
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Sujata Choudhury
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Hadi Elias
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Tapas Saha
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Susette Mueller
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Rabindra Roy
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States.
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Dixon M, Woodrick J, Gupta S, Karmahapatra SK, Devito S, Vasudevan S, Dakshanamurthy S, Adhikari S, Yenugonda VM, Roy R. Naturally occurring polyphenol, morin hydrate, inhibits enzymatic activity of N-methylpurine DNA glycosylase, a DNA repair enzyme with various roles in human disease. Bioorg Med Chem 2015; 23:1102-11. [PMID: 25650313 DOI: 10.1016/j.bmc.2014.12.067] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 12/19/2014] [Accepted: 12/28/2014] [Indexed: 10/24/2022]
Abstract
Interest in the mechanisms of DNA repair pathways, including the base excision repair (BER) pathway specifically, has heightened since these pathways have been shown to modulate important aspects of human disease. Modulation of the expression or activity of a particular BER enzyme, N-methylpurine DNA glycosylase (MPG), has been demonstrated to play a role in carcinogenesis and resistance to chemotherapy as well as neurodegenerative diseases, which has intensified the focus on studying MPG-related mechanisms of repair. A specific small molecule inhibitor for MPG activity would be a valuable biochemical tool for understanding these repair mechanisms. By screening several small molecule chemical libraries, we identified a natural polyphenolic compound, morin hydrate, which inhibits MPG activity specifically (IC50=2.6μM). Detailed mechanism analysis showed that morin hydrate inhibited substrate DNA binding of MPG, and eventually the enzymatic activity of MPG. Computational docking studies with an x-ray derived MPG structure as well as comparison studies with other structurally-related flavonoids offer a rationale for the inhibitory activity of morin hydrate observed. The results of this study suggest that the morin hydrate could be an effective tool for studying MPG function and it is possible that morin hydrate and its derivatives could be utilized in future studies focused on the role of MPG in human disease.
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Affiliation(s)
- Monica Dixon
- Department of Oncology, Georgetown Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, United States
| | - Jordan Woodrick
- Department of Oncology, Georgetown Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, United States
| | - Suhani Gupta
- Department of Oncology, Georgetown Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, United States
| | - Soumendra Krishna Karmahapatra
- Department of Oncology, Georgetown Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, United States
| | - Stephen Devito
- Department of Oncology, Georgetown Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, United States
| | - Sona Vasudevan
- Department of Biochemistry, Georgetown University Medical School, Washington, DC 20057, United States
| | - Sivanesan Dakshanamurthy
- Department of Oncology, Georgetown Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, United States
| | - Sanjay Adhikari
- Department of Oncology, Georgetown Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, United States
| | - Venkata M Yenugonda
- Department of Oncology, Georgetown Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, United States
| | - Rabindra Roy
- Department of Oncology, Georgetown Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, United States.
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Adhikari S, Chetram MA, Woodrick J, Mitra PS, Manthena PV, Khatkar P, Dakshanamurthy S, Dixon M, Karmahapatra SK, Nuthalapati NK, Gupta S, Narasimhan G, Mazumder R, Loffredo CA, Üren A, Roy R. Germ line variants of human N-methylpurine DNA glycosylase show impaired DNA repair activity and facilitate 1,N6-ethenoadenine-induced mutations. J Biol Chem 2014; 290:4966-4980. [PMID: 25538240 DOI: 10.1074/jbc.m114.627000] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Human N-methylpurine DNA glycosylase (hMPG) initiates base excision repair of a number of structurally diverse purine bases including 1,N(6)-ethenoadenine, hypoxanthine, and alkylation adducts in DNA. Genetic studies discovered at least eight validated non-synonymous single nucleotide polymorphisms (nsSNPs) of the hMPG gene in human populations that result in specific single amino acid substitutions. In this study, we tested the functional consequences of these nsSNPs of hMPG. Our results showed that two specific arginine residues, Arg-141 and Arg-120, are important for the activity of hMPG as the germ line variants R120C and R141Q had reduced enzymatic activity in vitro as well as in mammalian cells. Expression of these two variants in mammalian cells lacking endogenous MPG also showed an increase in mutations and sensitivity to an alkylating agent compared with the WT hMPG. Real time binding experiments by surface plasmon resonance spectroscopy suggested that these variants have substantial reduction in the equilibrium dissociation constant of binding (KD) of hMPG toward 1,N(6)-ethenoadenine-containing oligonucleotide (ϵA-DNA). Pre-steady-state kinetic studies showed that the substitutions at arginine residues affected the turnover of the enzyme significantly under multiple turnover condition. Surface plasmon resonance spectroscopy further showed that both variants had significantly decreased nonspecific (undamaged) DNA binding. Molecular modeling suggested that R141Q substitution may have resulted in a direct loss of the salt bridge between ϵA-DNA and hMPG, whereas R120C substitution redistributed, at a distance, the interactions among residues in the catalytic pocket. Together our results suggest that individuals carrying R120C and R141Q MPG variants may be at risk for genomic instability and associated diseases as a consequence.
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Affiliation(s)
- Sanjay Adhikari
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057,; Cancer Research Program, Houston Methodist Hospital Research Institute, Houston, Texas 77030, and
| | - Mahandranauth A Chetram
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057
| | - Jordan Woodrick
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057
| | - Partha S Mitra
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057
| | - Praveen V Manthena
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057
| | - Pooja Khatkar
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057
| | - Sivanesan Dakshanamurthy
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057
| | - Monica Dixon
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057
| | - Soumendra K Karmahapatra
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057
| | - Nikhil K Nuthalapati
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057
| | - Suhani Gupta
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057
| | - Ganga Narasimhan
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057
| | - Raja Mazumder
- Department of Biochemistry and Molecular Medicine, The George Washington University, Washington, D. C. 20037
| | - Christopher A Loffredo
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057
| | - Aykut Üren
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057
| | - Rabindra Roy
- From the Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057,.
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9
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Woodrick J, Gupta S, Khatkar P, Sarangi S, Narasimhan G, Trehan A, Adhikari S, Roy R. Slow repair of lipid peroxidation-induced DNA damage at p53 mutation hotspots in human cells caused by low turnover of a DNA glycosylase. Nucleic Acids Res 2014; 42:9033-46. [PMID: 25081213 PMCID: PMC4132702 DOI: 10.1093/nar/gku520] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 05/21/2014] [Accepted: 05/24/2014] [Indexed: 12/16/2022] Open
Abstract
Repair of oxidative stress- and inflammation-induced DNA lesions by the base excision repair (BER) pathway prevents mutation, a form of genomic instability which is often observed in cancer as 'mutation hotspots'. This suggests that some sequences have inherent mutability, possibly due to sequence-related differences in repair. This study has explored intrinsic mutability as a consequence of sequence-specific repair of lipid peroxidation-induced DNA adduct, 1, N(6)-ethenoadenine (εA). For the first time, we observed significant delay in repair of ϵA at mutation hotspots in the tumor suppressor gene p53 compared to non-hotspots in live human hepatocytes and endothelial cells using an in-cell real time PCR-based method. In-cell and in vitro mechanism studies revealed that this delay in repair was due to inefficient turnover of N-methylpurine-DNA glycosylase (MPG), which initiates BER of εA. We determined that the product dissociation rate of MPG at the hotspot codons was ≈5-12-fold lower than the non-hotspots, suggesting a previously unknown mechanism for slower repair at mutation hotspots and implicating sequence-related variability of DNA repair efficiency to be responsible for mutation hotspot signatures.
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Affiliation(s)
- Jordan Woodrick
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, USA
| | - Suhani Gupta
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, USA
| | - Pooja Khatkar
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, USA
| | - Sanchita Sarangi
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, USA
| | - Ganga Narasimhan
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, USA
| | - Akriti Trehan
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, USA
| | - Sanjay Adhikari
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, USA
| | - Rabindra Roy
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, USA
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Zaïr ZM, Johnson GE, Griffiths AP, Jenkins GJ. Diagnostic correlation between the expression of the DNA repair enzyme N-methylpurine DNA glycosylase and esophageal adenocarcinoma onset: a retrospective pilot study. Dis Esophagus 2013; 26:644-50. [PMID: 23137018 DOI: 10.1111/dote.12003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
EAC in its early stages, when it can potentially be cured, is rarely symptomatic and is associated with high mortality rates because in part of late-stage diagnosis. Given that DNA repair is an important contributory factor of early-stage malignancy, our study focused on the expression of the base excision repair enzyme N-methylpurine DNA glycosylase (MPG) in EAC disease onset. MPG messenger RNA (mRNA) expression levels were determined using quantitative reverse transcriptase polymerase chain reaction from a maximum of 72 patient samples. Immunohistochemistry was further utilized for the detection of MPG protein, and semiquantitative analysis performed using an H-score approach was carried out on a total of 130 archival tissue samples of different esophageal pathologies. Nuclear localized MPG protein was detected in all nonmalignant tissues derived from the enterohepatic system, with H-score values of 3.9-5.5 ± 0.4-1.0. In cancerous tissues derived from the enterohepatic system, a 9.5-fold increase in the level of MPG mRNA expression was specifically observed in the malignant regions located within the esophagus region. Further analysis revealed a 9- and 14-fold increase in MPG mRNA expression in EAC tumor, node, metastasis stages II and III, respectively, suggesting MPG expression to correlate with EAC disease progression. Immunohistochemistry analysis further showed a sevenfold significant increase in MPG protein expression in EAC tissues. Intriguingly, there was a fivefold significant decrease in nuclear localized MPG protein expression in tissues derived from Barrett's esophagus and low-grade dysplasia. Such findings highlight a complex regulatory pattern governing DNA glycosylase base excision repair initiation, as normal tissue undergoes Barrett's metaplasia and later dedifferentiates to EAC. Indeed, disease-stage-specific alterations in the expression of MPG may highlight a potential role for MPG in determining EAC onset and thus potentially be of clinical relevance for early disease detection and increased patient survival.
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Affiliation(s)
- Z M Zaïr
- Institute of Life Sciences, School of Medicine, Swansea University, Swansea, UK.
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Puch CBMD, Barbier E, Sauvaigo S, Gasparutto D, Breton J. Tools and strategies for DNA damage interactome analysis. Mutat Res 2012; 752:72-83. [PMID: 23220222 DOI: 10.1016/j.mrrev.2012.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 11/01/2012] [Accepted: 11/22/2012] [Indexed: 11/26/2022]
Abstract
DNA is the target of multiple endogenous and exogenous agents generating chemical lesions on the double helix. Cellular DNA damage response pathways rely on a myriad of proteins interacting with DNA alterations. The cartography of this interactome currently includes well known actors of chromatin remodelling, DNA repair or proteins hijacked from their natural functions such as transcription factors. In order to go further into the characterisation of these protein networks, proteomics-based methods began to be used in the early 2000s. The strategies are diverse and include mainly (i) damaged DNA molecules used as targets on protein microarrays, (ii) damaged DNA probes used to trap within complex cellular extracts proteins that are then separated and identified by proteomics, (iii) identification of chromatin- bound proteins after a genotoxic stress, or (iv) identification of proteins associated with other proteins already known to be part of DNA damage interactome. All these approaches have already been performed to find new proteins recognizing oxidised bases, abasic sites, strand breaks or crosslinks generated by anticancer drugs such as nitrogen mustards and platinating agents. Identified interactions are generally confirmed using complementary methods such as electromobility shift assays or surface plasmon resonance. These strategies allowed, for example, demonstration of interactions between cisplatin-DNA crosslinks and PARP-1 or the protein complex PTW/PP. The next challenging step will be to understand the biological repercussions of these newly identified interactions which may help to unravel new mechanisms involved in genetic toxicology, discover new cellular responses to anticancer drugs or identify new biomarkers and therapeutic targets.
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Affiliation(s)
| | - Ewa Barbier
- Laboratoire Lésions des Acides Nucléiques, SCIB, UMR-E3 CEA/UJF-Grenoble 1, INAC, 17 rue des Martyrs, Grenoble, F-38054, France
| | - Sylvie Sauvaigo
- Laboratoire Lésions des Acides Nucléiques, SCIB, UMR-E3 CEA/UJF-Grenoble 1, INAC, 17 rue des Martyrs, Grenoble, F-38054, France
| | - Didier Gasparutto
- Laboratoire Lésions des Acides Nucléiques, SCIB, UMR-E3 CEA/UJF-Grenoble 1, INAC, 17 rue des Martyrs, Grenoble, F-38054, France
| | - Jean Breton
- Laboratoire Lésions des Acides Nucléiques, SCIB, UMR-E3 CEA/UJF-Grenoble 1, INAC, 17 rue des Martyrs, Grenoble, F-38054, France; UFR de Pharmacie, Université Joseph Fourier-Grenoble 1, Domaine de la Merci, La Tronche, F-38706, France.
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Fedorova OS, Kuznetsov NA, Koval VV, Knorre DG. Conformational dynamics and pre-steady-state kinetics of DNA glycosylases. BIOCHEMISTRY (MOSCOW) 2011; 75:1225-39. [PMID: 21166640 DOI: 10.1134/s0006297910100044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Results of investigations of E. coli DNA glycosylases using pre-steady-state kinetics are considered. Special attention is given to the connection of conformational changes in the interacting biomolecules with kinetic mechanisms of the enzymatic processes.
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Affiliation(s)
- O S Fedorova
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk, Russia.
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Functional analysis of MUTYH mutated proteins associated with familial adenomatous polyposis. DNA Repair (Amst) 2010; 9:700-7. [PMID: 20418187 DOI: 10.1016/j.dnarep.2010.03.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Revised: 03/01/2010] [Accepted: 03/26/2010] [Indexed: 02/08/2023]
Abstract
The MUTYH DNA glycosylase specifically removes adenine misincorporated by replicative polymerases opposite the oxidized purine 8-oxo-7,8-dihydroguanine (8-oxoG). A defective protein activity results in the accumulation of G>T transversions because of unrepaired 8-oxoG:A mismatches. In humans, MUTYH germline mutations are associated with a recessive form of familial adenomatous polyposis and colorectal cancer predisposition (MUTYH-associated polyposis, MAP). Here we studied the repair capacity of the MUTYH variants R171W, E466del, 137insIW, Y165C and G382D, identified in MAP patients. Following expression and purification of human proteins from a bacterial system, we investigated MUTYH incision capacity on an 8-oxoG:A substrate by standard glycosylase assays. For the first time, we employed the surface plasmon resonance (SPR) technology for real-time recording of the association/dissociation of wild-type and MUTYH variants from an 8-oxoG:A DNA substrate. When compared to the wild-type protein, R171W, E466del and Y165C variants showed a severe reduction in the binding affinity towards the substrate, while 137insIW and G382D mutants manifested only a slight decrease mainly due to a slower rate of association. This reduced binding was always associated with impairment of glycosylase activity, with adenine removal being totally abrogated in R171W, E466del and Y165C and only partially reduced in 137insIW and G382D. Our findings demonstrate that SPR analysis is suitable to identify defective enzymatic behaviour even when mutant proteins display minor alterations in substrate recognition.
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A unified method for purification of basic proteins. Anal Biochem 2010; 400:203-6. [PMID: 20109435 DOI: 10.1016/j.ab.2010.01.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 01/06/2010] [Accepted: 01/08/2010] [Indexed: 11/22/2022]
Abstract
Protein purification is still very empirical, and a unified method for purifying proteins without an affinity tag is not available yet. In the postgenomic era, functional genomics, however, strongly demands such a method. In this paper we have formulated a unique method that can be applied for purifying any recombinant basic protein from Escherichia coli. Here, we have found that if the pH of the buffer is merely one pH unit below the isoelectric point (pI) of the recombinant proteins, most of the latter bind to the column. This result supports the Henderson-Hasselbalch principle. Considering that E. coli proteins are mostly acidic, and based on the pI determined theoretically, apparently all recombinant basic proteins (at least pI-1 > or = 6.94) may be purified from E. coli in a single step using a cation-exchanger resin, SP-Sepharose, and a selected buffer pH, depending on the pI of the recombinant protein. Approximately, two-fifths of human proteome, including many if not all nucleic acid-interacting proteins, have a pI of 7.94 or higher; virtually all these 12,000 proteins may be purified using this method in a single step.
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