1
|
Ronson GE, Starowicz K, Anthony EJ, Piberger AL, Clarke LC, Garvin AJ, Beggs AD, Whalley CM, Edmonds MJ, Beesley JFJ, Morris JR. Mechanisms of synthetic lethality between BRCA1/2 and 53BP1 deficiencies and DNA polymerase theta targeting. Nat Commun 2023; 14:7834. [PMID: 38030626 PMCID: PMC10687250 DOI: 10.1038/s41467-023-43677-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 11/16/2023] [Indexed: 12/01/2023] Open
Abstract
A synthetic lethal relationship exists between disruption of polymerase theta (Polθ), and loss of either 53BP1 or homologous recombination (HR) proteins, including BRCA1; however, the mechanistic basis of these observations are unclear. Here we reveal two distinct mechanisms of Polθ synthetic lethality, identifying dual influences of 1) whether Polθ is lost or inhibited, and 2) the underlying susceptible genotype. Firstly, we find that the sensitivity of BRCA1/2- and 53BP1-deficient cells to Polθ loss, and 53BP1-deficient cells to Polθ inhibition (ART558) requires RAD52, and appropriate reduction of RAD52 can ameliorate these phenotypes. We show that in the absence of Polθ, RAD52 accumulations suppress ssDNA gap-filling in G2/M and encourage MRE11 nuclease accumulation. In contrast, the survival of BRCA1-deficient cells treated with Polθ inhibitor are not restored by RAD52 suppression, and ssDNA gap-filling is prevented by the chemically inhibited polymerase itself. These data define an additional role for Polθ, reveal the mechanism underlying synthetic lethality between 53BP1, BRCA1/2 and Polθ loss, and indicate genotype-dependent Polθ inhibitor mechanisms.
Collapse
Affiliation(s)
- George E Ronson
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Katarzyna Starowicz
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Adthera Bio, Lyndon House, 62 Hagley Road, Birmingham, B16 8PE, UK
| | - Elizabeth J Anthony
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Ann Liza Piberger
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Lucy C Clarke
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- West Midlands Regional Genetics Laboratory, Birmingham Women's Hospital, Mindelsohn Way, Birmingham, B15 2TG, UK
| | - Alexander J Garvin
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- University of Leeds, Leeds, UK
| | - Andrew D Beggs
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Genomics Birmingham, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Celina M Whalley
- Genomics Birmingham, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Matthew J Edmonds
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Certara Insight, Danebrook Court, Oxford Office Village, Kidlington, Oxfordshire, OX5 1LQ, UK
| | - James F J Beesley
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Joanna R Morris
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
| |
Collapse
|
2
|
Piberger AL, Bowry A, Kelly RDW, Walker AK, González-Acosta D, Bailey LJ, Doherty AJ, Méndez J, Morris JR, Bryant HE, Petermann E. PrimPol-dependent single-stranded gap formation mediates homologous recombination at bulky DNA adducts. Nat Commun 2020; 11:5863. [PMID: 33203852 PMCID: PMC7673990 DOI: 10.1038/s41467-020-19570-7] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 10/15/2020] [Indexed: 11/09/2022] Open
Abstract
Stalled replication forks can be restarted and repaired by RAD51-mediated homologous recombination (HR), but HR can also perform post-replicative repair after bypass of the obstacle. Bulky DNA adducts are important replication-blocking lesions, but it is unknown whether they activate HR at stalled forks or behind ongoing forks. Using mainly BPDE-DNA adducts as model lesions, we show that HR induced by bulky adducts in mammalian cells predominantly occurs at post-replicative gaps formed by the DNA/RNA primase PrimPol. RAD51 recruitment under these conditions does not result from fork stalling, but rather occurs at gaps formed by PrimPol re-priming and resection by MRE11 and EXO1. In contrast, RAD51 loading at double-strand breaks does not require PrimPol. At bulky adducts, PrimPol promotes sister chromatid exchange and genetic recombination. Our data support that HR at bulky adducts in mammalian cells involves post-replicative gap repair and define a role for PrimPol in HR-mediated DNA damage tolerance.
Collapse
Affiliation(s)
- Ann Liza Piberger
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
| | - Akhil Bowry
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Richard D W Kelly
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Alexandra K Walker
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | | | - Laura J Bailey
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9RQ, UK
| | - Aidan J Doherty
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9RQ, UK
| | - Juan Méndez
- Molecular Oncology Program, Spanish National Cancer Research Centre, Madrid, Spain
| | - Joanna R Morris
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Helen E Bryant
- Department of Oncology & Metabolism, The Medical School, University of Sheffield, Sheffield, S10 2RX, UK
| | - Eva Petermann
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
| |
Collapse
|
3
|
Bowry A, Piberger AL, Rojas P, Saponaro M, Petermann E. BET Inhibition Induces HEXIM1- and RAD51-Dependent Conflicts between Transcription and Replication. Cell Rep 2019; 25:2061-2069.e4. [PMID: 30463005 PMCID: PMC6280123 DOI: 10.1016/j.celrep.2018.10.079] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 09/27/2018] [Accepted: 10/19/2018] [Indexed: 12/21/2022] Open
Abstract
BET bromodomain proteins are required for oncogenic transcription activities, and BET inhibitors have been rapidly advanced into clinical trials. Understanding the effects of BET inhibition on processes such as DNA replication will be important for future clinical applications. Here, we show that BET inhibition, and specifically inhibition of BRD4, causes replication stress through a rapid overall increase in RNA synthesis. We provide evidence that BET inhibition acts by releasing P-TEFb from its inhibitor HEXIM1, promoting interference between transcription and replication. Unusually, these transcription-replication conflicts do not activate the ATM/ATR-dependent DNA damage response but recruit the homologous recombination factor RAD51. Both HEXIM1 and RAD51 promote BET inhibitor-induced fork slowing but also prevent a DNA damage response. Our data suggest that BET inhibitors slow replication through concerted action of transcription and recombination machineries and shed light on the importance of replication stress in the action of this class of experimental cancer drugs.
Collapse
Affiliation(s)
- Akhil Bowry
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Ann Liza Piberger
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Patricia Rojas
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Marco Saponaro
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Eva Petermann
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
| |
Collapse
|
4
|
Ronson GE, Piberger AL, Higgs MR, Olsen AL, Stewart GS, McHugh PJ, Petermann E, Lakin ND. PARP1 and PARP2 stabilise replication forks at base excision repair intermediates through Fbh1-dependent Rad51 regulation. Nat Commun 2018; 9:746. [PMID: 29467415 PMCID: PMC5821833 DOI: 10.1038/s41467-018-03159-2] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 01/24/2018] [Indexed: 12/22/2022] Open
Abstract
PARP1 regulates the repair of DNA single-strand breaks generated directly, or during base excision repair (BER). However, the role of PARP2 in these and other repair mechanisms is unknown. Here, we report a requirement for PARP2 in stabilising replication forks that encounter BER intermediates through Fbh1-dependent regulation of Rad51. Whereas PARP2 is dispensable for tolerance of cells to SSBs or homologous recombination dysfunction, it is redundant with PARP1 in BER. Therefore, combined disruption of PARP1 and PARP2 leads to defective BER, resulting in elevated levels of replication-associated DNA damage owing to an inability to stabilise Rad51 at damaged replication forks and prevent uncontrolled DNA resection. Together, our results demonstrate how PARP1 and PARP2 regulate two independent, but intrinsically linked aspects of DNA base damage tolerance by promoting BER directly, and by stabilising replication forks that encounter BER intermediates.
Collapse
Affiliation(s)
- George E Ronson
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Ann Liza Piberger
- Institute of Cancer and Genomic Sciences, University of Birmingham, Edgbaston, B15 2TT, Birmingham, UK
| | - Martin R Higgs
- Institute of Cancer and Genomic Sciences, University of Birmingham, Edgbaston, B15 2TT, Birmingham, UK
| | - Anna L Olsen
- Department of Oncology, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK
| | - Grant S Stewart
- Institute of Cancer and Genomic Sciences, University of Birmingham, Edgbaston, B15 2TT, Birmingham, UK
| | - Peter J McHugh
- Department of Oncology, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK
| | - Eva Petermann
- Institute of Cancer and Genomic Sciences, University of Birmingham, Edgbaston, B15 2TT, Birmingham, UK
| | - Nicholas D Lakin
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
| |
Collapse
|
5
|
Piberger AL, Krüger CT, Strauch BM, Schneider B, Hartwig A. BPDE-induced genotoxicity: relationship between DNA adducts, mutagenicity in the in vitro PIG-A assay, and the transcriptional response to DNA damage in TK6 cells. Arch Toxicol 2017; 92:541-551. [PMID: 28593498 PMCID: PMC5773665 DOI: 10.1007/s00204-017-2003-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 05/31/2017] [Indexed: 12/16/2022]
Abstract
Benzo[a]pyrene is a known human carcinogen. As underlying mechanism, the induction of stable DNA adducts and mutations have been repeatedly demonstrated. Also, the activation of cellular stress response on the transcriptional level has been described. Nevertheless, the interrelationship between these different events is less well understood, especially at low, for human exposure relevant concentrations. Within the present study, we applied the reactive metabolite benzo[a]pyrene diolepoxide (BPDE) in the nanomolar, non-cytotoxic concentration range in human TK6 cells and quantified the induction and repair of stable DNA adducts at the N2-position of guanine by HPLC with fluorescence detection. Significant levels of DNA lesions were detected even at the lowest concentration of 10 nM BPDE, with a linear increase up to 50 nM. Relative repair was similar at all damage levels, reaching about 30% after 8 h and 60% after 24 h. Mutation frequencies were quantified as GPI-deficient cells by the recently established in vitro PIG-A mutagenicity assay. Again, a linear dose–response-relationship in the before-mentioned concentration range was observed, also when plotting the number of GPI-deficient cells against the number of DNA adducts. Furthermore, we explored the time- and concentration-dependent DNA damage response on the transcriptional level via a high-throughput RT-qPCR technique by quantifying the impact of BPDE on the transcription of 95 genes comprising DNA damage response, DNA repair factors, oxidative stress response, cell cycle arrest, cell proliferation, and apoptosis. As expected, BPDE activated DNA damage signaling, p53 and AP-1 dependent signaling, oxidative stress response, and apoptosis. However, in contrast to DNA adducts and mutations, the onset of the transcriptional DNA damage response was restricted to higher concentrations, indicating that its respective activations require a certain level of DNA lesions. Altogether, the results indicate that in case of BPDE, DNA lesions and mutations were correlated at all concentrations, suggesting that repair is not complete even at low levels of DNA damage. Considering the ongoing discussion on potential thresholds also for genotoxic carcinogens, the results are of major relevance, both with respect to basic research as well as to risk assessment of chemical carcinogens.
Collapse
Affiliation(s)
- Ann Liza Piberger
- Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Christopher T Krüger
- Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Bettina M Strauch
- Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Beatrice Schneider
- Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Andrea Hartwig
- Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany.
| |
Collapse
|
6
|
Fischer BM, Neumann D, Piberger AL, Risnes SF, Köberle B, Hartwig A. Use of high-throughput RT-qPCR to assess modulations of gene expression profiles related to genomic stability and interactions by cadmium. Arch Toxicol 2016; 90:2745-2761. [PMID: 26525392 PMCID: PMC5065590 DOI: 10.1007/s00204-015-1621-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/20/2015] [Indexed: 01/21/2023]
Abstract
Predictive test systems to assess the mode of action of chemical carcinogens are urgently required. Within the present study, we applied the Fluidigm dynamic array on the BioMark™ HD System for quantitative high-throughput RT-qPCR analysis of 95 genes and 96 samples in parallel, selecting genes crucial for maintaining genomic stability, including stress response as well as DNA repair, cell cycle control, apoptosis and mitotic signaling. The specificity of each individually designed sequence-specific primer pair and their respective target amplicons were evaluated via melting curve analysis as part of qPCR and size verification via agarose gel electrophoresis. For each gene, calibration curves displayed high efficiencies and correlation coefficients in the identified linear dynamic range as well as low intra-assay variations. Data were processed via Fluidigm real-time PCR analysis and GenEx software, and results were depicted as relative gene expression according to the ΔΔC q method. Subsequently, gene expression analyses were conducted in cadmium-treated adenocarcinoma A549 and epithelial bronchial BEAS-2B cells. They revealed distinct dose- and time-dependent and also cell-type-specific gene expression patterns, including the induction of genes coding for metallothioneins, the oxidative stress response, cell cycle control, mitotic signaling and apoptosis. Interestingly, while genes coding for the DNA damage response were induced, distinct DNA repair genes were down-regulated at the transcriptional level. Thus, this approach provided a comprehensive overview on the interaction by cadmium with distinct signaling pathways, also reflecting molecular modes of action in cadmium-induced carcinogenicity. Therefore, the test system appears to be a promising tool for toxicological risk assessment.
Collapse
Affiliation(s)
- Bettina Maria Fischer
- Department of Food Chemistry and Toxicology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131, Karlsruhe, Germany
| | - Daniel Neumann
- Department of Food Chemistry and Toxicology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131, Karlsruhe, Germany
| | - Ann Liza Piberger
- Department of Food Chemistry and Toxicology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131, Karlsruhe, Germany
| | - Sarah Fremgaard Risnes
- Department of Food Chemistry and Toxicology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131, Karlsruhe, Germany
| | - Beate Köberle
- Department of Food Chemistry and Toxicology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131, Karlsruhe, Germany
| | - Andrea Hartwig
- Department of Food Chemistry and Toxicology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131, Karlsruhe, Germany.
| |
Collapse
|
7
|
Piberger AL, Keil C, Platz S, Rohn S, Hartwig A. Sulforaphane inhibits damage-induced poly (ADP-ribosyl)ation via direct interaction of its cellular metabolites with PARP-1. Mol Nutr Food Res 2015; 59:2231-42. [PMID: 26310710 DOI: 10.1002/mnfr.201500457] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Revised: 07/31/2015] [Accepted: 08/11/2015] [Indexed: 12/13/2022]
Abstract
SCOPE The isothiocyanate sulforaphane, a major breakdown product of the broccoli glucosinolate glucoraphanin, has frequently been proposed to exert anticarcinogenic properties. Potential underlying mechanisms include a zinc release from Kelch-like ECH-associated protein 1 followed by the induction of detoxifying enzymes. This suggests that sulforaphane may also interfere with other zinc-binding proteins, e.g. those essential for DNA repair. Therefore, we explored the impact of sulforaphane on poly (ADP-ribose)polymerase-1 (PARP-1), poly (ADP-ribosyl)ation (PARylation), and DNA single-strand break repair (SSBR) in cell culture. METHODS AND RESULTS Immunofluorescence analyses showed that sulforaphane diminished H2 O2 -induced PARylation in HeLa S3 cells starting from 15 μM despite increased lesion induction under these conditions. Subcellular experiments quantifying the damage-induced incorporation of (32) P-ADP-ribose by PARP-1 displayed no direct impact of sulforaphane itself, but cellular metabolites, namely the glutathione conjugates of sulforaphane and its interconversion product erucin, reduced PARP-1 activity concentration dependently. Interestingly, this sulforaphane metabolite-induced PARP-1 inhibition was prevented by thiol compounds. PARP-1 is a stimulating factor for DNA SSBR-rate and we further demonstrated that 25 μM sulforaphane also delayed the rejoining of H2 O2 -induced DNA strand breaks, although this might be partly due to increased lesion frequencies. CONCLUSION Sulforaphane interferes with damage-induced PARylation and SSBR, which implies a sulforaphane-dependent impairment of genomic stability.
Collapse
Affiliation(s)
- Ann Liza Piberger
- Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Claudia Keil
- Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Stefanie Platz
- Institute of Food Chemistry, Hamburg School of Food Science, University Hamburg, Hamburg, Germany
| | - Sascha Rohn
- Institute of Food Chemistry, Hamburg School of Food Science, University Hamburg, Hamburg, Germany
| | - Andrea Hartwig
- Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology, Karlsruhe, Germany
| |
Collapse
|
8
|
Bausinger J, Schütz P, Piberger AL, Speit G. Further characterization of benzo[a]pyrene diol-epoxide (BPDE)-induced comet assay effects. Mutagenesis 2015; 31:161-9. [DOI: 10.1093/mutage/gev067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
9
|
Platz S, Piberger AL, Budnowski J, Herz C, Schreiner M, Blaut M, Hartwig A, Lamy E, Hanske L, Rohn S. Bioavailability and biotransformation of sulforaphane and erucin metabolites in different biological matrices determined by LC–MS–MS. Anal Bioanal Chem 2015; 407:1819-29. [DOI: 10.1007/s00216-015-8482-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 01/04/2015] [Accepted: 01/10/2015] [Indexed: 12/01/2022]
|
10
|
Piberger AL, Köberle B, Hartwig A. The broccoli-born isothiocyanate sulforaphane impairs nucleotide excision repair: XPA as one potential target. Arch Toxicol 2013; 88:647-58. [PMID: 24352536 DOI: 10.1007/s00204-013-1178-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 11/26/2013] [Indexed: 11/28/2022]
Abstract
The isothiocyanate sulforaphane (SFN), the major hydrolysis product of glucosinolates present in broccoli, has frequently been proposed to exert anticarcinogenic properties, mainly due to the induction of the nrf2/Keap1/ARE-signaling pathway. As potential underlying mechanism, a SFN-dependent zinc release from Keap1, the negative regulator of nrf2, has been described. This raises the question whether SFN is able to interfere with other zinc binding structures as well, for example those essential for DNA repair. Within this study, a SFN-induced deliberation of zinc from a synthesized peptide resembling the zinc binding domain of the xeroderma pigmentosum A (XPA) protein was observed starting at 50 μM SFN. Since XPA is absolutely required for nucleotide excision repair, the impact of SFN on the repair of (+)-anti-benzo[a]pyrene 7,8-diol-9,10-epoxide ((+)-anti-BPDE)-induced DNA adducts in HCT 116 cells was investigated. While preincubation with SFN did not affect initial lesion levels, a dose-dependent repair inhibition of (+)-anti-BPDE-induced DNA damage during the first 12 h after lesion induction was observed, starting at 1 μM SFN. In contrast, the later phase of DNA repair was not impaired by SFN. In support of an inactivation of XPA also in cells, SFN increased the (+)-anti-BPDE-induced cytotoxicity XPA dependently in XP12RO cells. Comparison of p53-proficient and p53-deficient cells revealed no difference in SFN-induced DNA repair inhibition, indicating that p53 is no cellular target of SFN. Since DNA repair processes are required to maintain DNA integrity, the presented data suggest a potential impairment of genomic stability by SFN.
Collapse
Affiliation(s)
- Ann Liza Piberger
- Department of Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | | | | |
Collapse
|