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Kojima K, Ohkubo H, Kawasumi R, Hirota K. Pold4 subunit of replicative polymerase δ promotes fork slowing at broken templates. DNA Repair (Amst) 2024; 139:103688. [PMID: 38678695 DOI: 10.1016/j.dnarep.2024.103688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 02/25/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024]
Abstract
Single-strand breaks (SSBs) are the most frequent type of lesion, and replication across such lesions leads to double-strand breaks (DSBs). DSBs that arise during replication are repaired by homologous recombination (HR) and are suppressed by fork reversal. Poly[ADP-ribose] polymerase I (PARP1) and the proofreading exonuclease activity of replicative polymerase ε (Polε) are required for fork reversal when leading strand replication encounters SSBs. However, the mechanism underlying fork reversal at the SSB during lagging-strand replication remains elusive. We here demonstrate that the Pold4 subunit of replicative polymerase δ (Polδ) plays a role in promoting fork reversal during lagging strand replication on a broken template. POLD4-/- cells exhibited heightened sensitivity to camptothecin (CPT) but not to other DNA-damaging agents compared to wild-type cells. This selective CPT sensitivity in POLD4-/- cells suggests that Pold4 suppresses DSBs during replication, as CPT induces significant SSBs during replication, which subsequently lead to DSBs. To explore the functional interactions among Pold4, Polε exonuclease, and PARP1 in DSB suppression, we generated PARP1-/-, POLD4-/-, Polε exonuclease-deficient POLE1exo-/-, PARP1-/-/POLD4-/-, and POLD4-/-/POLE1exo-/- cells. These epistasis analyses showed that Pold4 is involved in the PARP1-Polε exonuclease-mediated fork reversal following CPT treatment. These results suggest that Pold4 aids in fork reversal when lagging strand replication stalls on a broken template. In conclusion, the Pold4 subunit of Polδ has roles in the PARP1-Polε exonuclease-mediated fork reversal, contributing to the suppression of DSBs.
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Affiliation(s)
- Kota Kojima
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Hiromori Ohkubo
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Ryotaro Kawasumi
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Kouji Hirota
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan.
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Su M, Zhou S, Li J, Lin N, Chi T, Zhang M, Lv X, Hu Y, Bai T, Chang F. Benzo(a)pyrene regulates chaperone-mediated autophagy via heat shock protein 90. Toxicol Lett 2023:S0378-4274(23)00208-4. [PMID: 37390851 DOI: 10.1016/j.toxlet.2023.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 05/23/2023] [Accepted: 06/26/2023] [Indexed: 07/02/2023]
Abstract
AIMS Some studies have shown that the Benzo(a)pyrene (BaP) exposure induced oxidative damage, DNA damage and autophagy, but the molecular mechanism is not clear. Heat shock protein 90 (HSP90) is regarded as an important target in cancer therapy and a key factor in autophagy. Therefore, this study aims to clarify the new mechanism of BaP regulating CMA through HSP90. MAIN METHODS C57BL mice were fed with BaP at a dose of 25.3mg/kg. A549 cells were treated with different concerntrations of BaP, and MTT assay was used to observe the effect of BaP on the proliferation of A549 cells. DNA damage was detected by alkaline comet assay. Focus experiment for detection of γ-H2AX by immunofluorescence. The mRNA expression of HSP90, HSC70 and Lamp-2a was detected by qPCR. The protein expressions of HSP90, HSC70 and Lamp-2a were detected by Western blot. Next, we knocked down HSP90 expression by the HSP90 Inhibitor, NVP-AUY 922, exposed or HSP90α shRNA lentivirus transduction in A549 cells. KEY FINDINGS In these studies, we first found that heat shock protein 90 (HSP90), heat shock cognate 70 (HSC70) and lysosomal-associated membrane protein type 2 receptor (Lamp-2a) expressions of C57BL mice lung tissue and A549 cells exposed to BaP were significant increase, as well as BaP induced DNA double-strand breaks (DSBs) and activated DNA damage responses, as evidenced by comet assay and γ-H2AX foci analysis in A549 cells. Our results demonstrated BaP induced CMA and caused DNA damage. Next, we knocked down HSP90 expression by the HSP90 Inhibitor, NVP-AUY 922, exposed or HSP90α shRNA lentivirus transduction in A549 cells. HSC70 and Lamp-2a expressions of these cells exposed to BaP were not significant increase, which showed that BaP inducted CMA was mediated by HSP90. Further, HSP90α shRNA prevented BaP induced of BaP which suggested BaP regulated CMA and caused DNA damage by HSP90. Our results elucidated a new mechanism of BaP regulated CMA through HSP90. SIGNIFICANCE BaP regulated CMA through HSP90. HSP90 is involved in the regulation of gene instability induced by DNA damage by BaP, which promotes CMA. Our study also revealed that BaP regulates CMA through HSP90. This study fills the gap of the effect of BaP on autophagy and its mechanism, which will lead to a more comprehensive understanding of the action mechanism of BaP.
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Affiliation(s)
- Min Su
- School of Pharmacy, Inner Mongolia Medical University, Hohhot, China
| | - Shuhong Zhou
- School of Pharmacy, Inner Mongolia Medical University, Hohhot, China; School of Basic Medicine, Inner Mongolia Medical University, Hohhot, China
| | - Jun Li
- School of Pharmacy, Inner Mongolia Medical University, Hohhot, China; GLP Center of Inner Mongolia Medical University, Hohhot, China; Inner Mongolia New Drug Screening Engineering Research Center, Hohhot, China
| | - Nan Lin
- School of Pharmacy, Inner Mongolia Medical University, Hohhot, China
| | - Tao Chi
- School of Pharmacy, Inner Mongolia Medical University, Hohhot, China
| | - Mengdi Zhang
- School of Pharmacy, Inner Mongolia Medical University, Hohhot, China; GLP Center of Inner Mongolia Medical University, Hohhot, China
| | - Xiaoli Lv
- School of Pharmacy, Inner Mongolia Medical University, Hohhot, China; Inner Mongolia New Drug Screening Engineering Research Center, Hohhot, China
| | - Yuxia Hu
- School of Pharmacy, Inner Mongolia Medical University, Hohhot, China; GLP Center of Inner Mongolia Medical University, Hohhot, China; Inner Mongolia New Drug Screening Engineering Research Center, Hohhot, China
| | - Tuya Bai
- School of Pharmacy, Inner Mongolia Medical University, Hohhot, China; Inner Mongolia New Drug Screening Engineering Research Center, Hohhot, China.
| | - Fuhou Chang
- School of Pharmacy, Inner Mongolia Medical University, Hohhot, China.
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3
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Washif M, Ahmad T, Hosen MB, Rahman MR, Taniguchi T, Okubo H, Hirota K, Kawasumi R. CTF18-RFC contributes to cellular tolerance against chain-terminating nucleoside analogs (CTNAs) in cooperation with proofreading exonuclease activity of DNA polymerase ε. DNA Repair (Amst) 2023; 127:103503. [PMID: 37099849 DOI: 10.1016/j.dnarep.2023.103503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 04/10/2023] [Accepted: 04/18/2023] [Indexed: 04/28/2023]
Abstract
Chemotherapeutic nucleoside analogs, such as cytarabine (Ara-C), are incorporated into genomic DNA during replication. Incorporated Ara-CMP (Ara-cytidine monophosphate) serves as a chain terminator and inhibits DNA synthesis by replicative polymerase epsilon (Polε). The proofreading exonuclease activity of Polε removes the misincorporated Ara-CMP, thereby contributing to the cellular tolerance to Ara-C. Purified Polε performs proofreading, and it is generally believed that proofreading in vivo does not need additional factors. In this study, we demonstrated that the proofreading by Polε in vivo requires CTF18, a component of the leading-strand replisome. We found that loss of CTF18 in chicken DT40 cells and human TK6 cells results in hypersensitivity to Ara-C, indicating the conserved function of CTF18 in the cellular tolerance of Ara-C. Strikingly, we found that proofreading-deficient POLE1D269A/-, CTF18-/-, and POLE1D269A/-/CTF18-/- cells showed indistinguishable phenotypes, including the extent of hypersensitivity to Ara-C and decreased replication rate with Ara-C. This observed epistatic relationship between POLE1D269A/- and CTF18-/- suggests that they are interdependent in removing mis-incorporated Ara-CMP from the 3' end of primers. Mechanistically, we found that CTF18-/- cells have reduced levels of chromatin-bound Polε upon Ara-C treatment, suggesting that CTF18 contributes to the tethering of Polε on fork at the stalled end and thereby facilitating the removal of inserted Ara-C. Collectively, these data reveal the previously unappreciated role of CTF18 in Polε-exonuclease-mediated maintenance of the replication fork upon Ara-C incorporation.
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Affiliation(s)
- Mubasshir Washif
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Tasnim Ahmad
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Md Bayejid Hosen
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Md Ratul Rahman
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Tomoya Taniguchi
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Hiromori Okubo
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Kouji Hirota
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Ryotaro Kawasumi
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan.
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Lestaurtinib induces DNA damage that is related to estrogen receptor activation. Curr Res Toxicol 2022; 4:100102. [PMID: 36619290 PMCID: PMC9816669 DOI: 10.1016/j.crtox.2022.100102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 12/22/2022] [Accepted: 12/22/2022] [Indexed: 12/26/2022] Open
Abstract
A number of chemicals in the environment pose a threat to human health. Recent studies indicate estradiol induces DNA damage through the activation of the estrogen receptor alpha (ERα). Given that many environmental chemical compounds act like hormones once they enter the human body, it is possible that they induce DNA damage in the same way as estradiol, which is of great concern to females with the BRCA1 mutation. In this study, we developed an antibody-based high content method measuring γH2AX, a biomarker for DNA damage, to test a subset of 907 chemical compounds in MCF7 cells. The assay was optimized for a 1536 well plate format and had a satisfactory assay performance with Z-factor of 0.67. From the screening, we identified 128 compounds that induce γH2AX expression in the cells. These compounds were further examined for their γH2AX induction in the presence of an ER inhibitor, tamoxifen. After tamoxifen treatment, four compounds induced less γH2AX expression compared to those without tamoxifen treatment, suggesting these compounds induced γH2AX that is related to ERα activation. These four compounds were chosen for further studies to assess their ERα activating capability and c-MYC induction. Only lestaurtinib, a selective tyrosine kinase inhibitor, induced ERα activation, which was confirmed by both ERα beta-lactamase reporter gene assay and molecular docking analysis. Lestaurtinib also increased c-MYC expression, a target gene of ERα signaling, measured by the quantitative PCR method. This data suggests that lestaurtinib acts as a DNA damage inducer that is related to ERα activation.
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Sharin T, Gyasi H, Jones SP, Crump D, O'Brien JM. Concentration- and time-dependent induction of Cyp1a and DNA damage response by benzo(a)pyrene in LMH three-dimensional spheroids. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2021; 62:319-327. [PMID: 33956355 DOI: 10.1002/em.22433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/29/2021] [Accepted: 05/04/2021] [Indexed: 06/12/2023]
Abstract
In vitro liver toxicity tests performed using cell lines cultured as two-dimensional (2D) monolayer have limited CYP450 activity and may be inadequate for screening chemicals that require activation to exert toxicity. Metabolic competence is greatly improved using three-dimensional (3D) cell culture. In this study, Cyp1a induction, and subsequent DNA damage response induced by benzo(a)pyrene (BaP) were compared in 2D monolayer cells and 3D spheroids of the chicken hepatic cell line, LMH. Cells were exposed to BaP (0.1-100 μM) for different durations: 8, 24, 35, or 48 hr. Cyp1a activity, mRNA expression of Cyp1a and DNA damage response (DDR) genes, and phosphorylation of H2AX (γH2AX) were determined using the EROD assay, a customized PCR array, and flow cytometry, respectively. EROD activity was induced at 8 hr and achieved maximal induction at 24 hr in spheroids; earlier time points than for monolayer cells. In spheroids, BaP exposure resulted in a concentration-dependent increase in Cyp1a4 mRNA expression at 8 hr followed by upregulation of DDR genes at 24 hr, whereas Cyp1a4 mRNA induction was only observed at 48 hr in monolayer cells. Cyp1a5 mRNA was induced at 8 hr in monolayer cells but maximum induction was greater in spheroids. An increase in γH2AX was observed at 24 hr in spheroids; this endpoint was not evaluated in monolayer cells. These results suggest that BaP metabolism precedes the DNA damage response and occurs earlier in 3D spheroids. This study demonstrates that LMH 3D spheroids could be a suitable metabolically-competent in vitro model to measure genotoxicity of chemicals that require metabolic activation by Cyp1a.
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Affiliation(s)
- Tasnia Sharin
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Helina Gyasi
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Stephanie P Jones
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
| | - Doug Crump
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
| | - Jason M O'Brien
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
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6
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Kojima K, Ooka M, Abe T, Hirota K. Pold4, the fourth subunit of replicative polymerase δ, suppresses gene conversion in the immunoglobulin-variable gene in avian DT40 cells. DNA Repair (Amst) 2021; 100:103056. [PMID: 33588156 DOI: 10.1016/j.dnarep.2021.103056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/26/2021] [Accepted: 01/28/2021] [Indexed: 10/22/2022]
Abstract
The replicative polymerase δ (Polδ), consisting of four subunits, plays a pivotal role in chromosomal replication. Pold4, the smallest subunit of Polδ, is believed to contribute to the regulation of replication by facilitating repair in response to DNA damage. However, that contribution has not been fully elucidated. We here show that Pold4 contributes to the suppression of gene conversion in immunoglobulin-variable (IgV) gene diversification in the chicken DT40 lymphocyte cell line, where gene conversion diversifies the IgV gene through intragenic homologous recombination (HR) between diverged pseudo-V segments. IgV gene conversion is initiated by activation-induced cytidine deaminase-mediated uracil formation in the IgV gene, which in turn converts into an abasic site, leading to replication arrest. POLD4-/- cells exhibited an increased rate of IgV gene conversion. Moreover, the gene-conversion tract was lengthened and the usage of pseudo-V segments was altered, showing a preference, to use the diverged sequence as a donor in POLD4-/- cells. These data suggest that Pold4 is involved in the regulation of HR-mediated gene conversion in IgV diversification. By contrast, the rate in HR-mediated, sister-chromatid exchange and gene-targeting induced by an I-SceI endonclease-mediated DNA double-strand break exhibited by POLD4-/- cells was indistinguishable from that by wild-type cells. These findings indicate that the functionality of general HR is preserved in POLD4-/- cells. In conclusion, Pold4 is involved in the suppression of IgV-gene conversion without affecting the general functionality of HR.
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Affiliation(s)
- Kota Kojima
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Masato Ooka
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Takuya Abe
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Kouji Hirota
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan.
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7
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Koklesova L, Liskova A, Samec M, Qaradakhi T, Zulli A, Smejkal K, Kajo K, Jakubikova J, Behzadi P, Pec M, Zubor P, Biringer K, Kwon TK, Büsselberg D, Sarria GR, Giordano FA, Golubnitschaja O, Kubatka P. Genoprotective activities of plant natural substances in cancer and chemopreventive strategies in the context of 3P medicine. EPMA J 2020; 11:261-287. [PMID: 32547652 PMCID: PMC7272522 DOI: 10.1007/s13167-020-00210-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 05/16/2020] [Indexed: 12/12/2022]
Abstract
Severe durable changes may occur to the DNA structure caused by exogenous and endogenous risk factors initiating the process of carcinogenesis. By evidence, a large portion of malignancies have been demonstrated as being preventable. Moreover, the targeted prevention of cancer onset is possible, due to unique properties of plant bioactive compounds. Although genoprotective effects of phytochemicals have been well documented, there is an evident lack of articles which would systematically present the spectrum of anticancer effects by phytochemicals, plant extracts, and plant-derived diet applicable to stratified patient groups at the level of targeted primary (cancer development) and secondary (cancer progression and metastatic disease) prevention. Consequently, clinical implementation of knowledge accumulated in the area is still highly restricted. To stimulate coherent co-development of the dedicated plant bioactive compound investigation on one hand and comprehensive cancer preventive strategies on the other hand, the current paper highlights and deeply analyses relevant evidence available in the area. Key molecular mechanisms are presented to detail genoprotective and anticancer activities of plants and phytochemicals. Clinical implementation is discussed. Based on the presented evidence, advanced chemopreventive strategies in the context of 3P medicine are considered.
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Affiliation(s)
- Lenka Koklesova
- Department of Obstetrics and Gynecology, Jessenius Faculty of Medicine, Comenius University in Bratislava, 036 01 Martin, Slovakia
| | - Alena Liskova
- Department of Obstetrics and Gynecology, Jessenius Faculty of Medicine, Comenius University in Bratislava, 036 01 Martin, Slovakia
| | - Marek Samec
- Department of Obstetrics and Gynecology, Jessenius Faculty of Medicine, Comenius University in Bratislava, 036 01 Martin, Slovakia
| | - Tawar Qaradakhi
- Institute for Health and Sport, Victoria University, Melbourne, VIC Australia
| | - Anthony Zulli
- Institute for Health and Sport, Victoria University, Melbourne, VIC Australia
| | - Karel Smejkal
- Department of Natural Drugs, Faculty of Pharmacy, Masaryk University, 612 42 Brno, Czech Republic
| | - Karol Kajo
- Department of Pathology, St. Elisabeth Oncology Institute, 812 50 Bratislava, Slovakia
- Biomedical Research Center, Slovak Academy of Sciences, 845 05 Bratislava, Slovakia
| | - Jana Jakubikova
- Biomedical Research Center SAS, Cancer Research Institute, Bratislava, Slovakia
| | - Payam Behzadi
- Department of Microbiology, College of Basic Sciences, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran
| | - Martin Pec
- Department of Medical Biology, Jessenius Faculty of Medicine, Comenius University in Bratislava, 03601 Martin, Slovakia
| | - Pavol Zubor
- Department of Gynecologic Oncology, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
- OBGY Health & Care, Ltd., 01001 Zilina, Slovakia
| | - Kamil Biringer
- Department of Obstetrics and Gynecology, Jessenius Faculty of Medicine, Comenius University in Bratislava, 036 01 Martin, Slovakia
| | - Taeg Kyu Kwon
- Department of Immunology and School of Medicine, Keimyung University, Dalseo-Gu, Daegu, 42601 Korea
| | - Dietrich Büsselberg
- Department of Physiology and Biophysics, Weill Cornell Medicine-Qatar, Education City, Qatar Foundation, P.O. Box 24144, Doha, Qatar
| | - Gustavo R. Sarria
- Department of Radiation Oncology, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Frank A. Giordano
- Department of Radiation Oncology, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Olga Golubnitschaja
- Predictive, Preventive and Personalised (3P) Medicine, Department of Radiation Oncology, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Peter Kubatka
- Department of Medical Biology, Jessenius Faculty of Medicine, Comenius University in Bratislava, 03601 Martin, Slovakia
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Chen Z, Yang L, Huang Y, Spencer P, Zheng W, Zhou Y, Jiang S, Ye W, Zheng Y, Qu W. Carcinogenic risk of N-Nitrosamines in Shanghai Drinking Water: Indications for the Use of Ozone Pretreatment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:7007-7018. [PMID: 31083987 DOI: 10.1021/acs.est.8b07363] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
N-Nitrosamines are drinking water disinfection byproducts that pose a high carcinogenic risk. We hypothesized that raw water treatment processes influence the types and concentrations of nitrosamines in drinking water, thereby posing differential health risks. We compared the finished water of two water treatment plants (WTP-A, WTP-B) serving Shanghai, China. Both plants use the Qingcaosha reservoir as a water source to generate drinking water with conventional but distinct treatment processes, namely preoxidation with sodium hypochlorite (WTP-A) vs ozone (WTP-B). Average nitrosamine concentrations, especially that of the probable human carcinogen (2A) N-nitrosodimethylamine, were higher in finished (drinking) water from WTP-A (35.83 ng/L) than from WTP-B (5.07 ng/L). Other differences in mean nitrosamines in drinking water included N-nitrosodipropylamine (42.62 ng/L) and N-nitrosomethylethylamine (26.73 ng/L) in WTP-A in contrast to N-nitrosodiethylamine (7.26 ng/L) and N-nitrosopyrrolidine (59.12 ng/L) in WTP-B. The estimated adult cancer risk from exposure to mixed nitrosamines was 1.83 times higher from WTP-A than from WTP-B drinking water. Children exposed to nitrosamines had a significantly higher cancer risk than adults ( p < 0.05). Disease burden exceeded 106 person-years. Taken together, these data suggest that use of ozone in the preoxidation step can reduce nitrosamine formation in drinking water and thereby lower the population cancer health risk.
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Affiliation(s)
- Zhiyuan Chen
- Centers for Water and Health, Key Laboratory of Health Technology Assessment, National Health Commission of the People's Republic of China, Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health , Fudan University , Shanghai , 200032 , China
| | - Lan Yang
- Centers for Water and Health, Key Laboratory of Health Technology Assessment, National Health Commission of the People's Republic of China, Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health , Fudan University , Shanghai , 200032 , China
| | - Yu Huang
- Centers for Water and Health, Key Laboratory of Health Technology Assessment, National Health Commission of the People's Republic of China, Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health , Fudan University , Shanghai , 200032 , China
| | - Peter Spencer
- Oregon Institute of Occupational Health Sciences, and Department of Neurology, School of Medicine , Oregon Health & Science University , Portland , Oregon 97239 , United States
| | - Weiwei Zheng
- Centers for Water and Health, Key Laboratory of Health Technology Assessment, National Health Commission of the People's Republic of China, Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health , Fudan University , Shanghai , 200032 , China
| | - Ying Zhou
- Centers for Water and Health, Key Laboratory of Health Technology Assessment, National Health Commission of the People's Republic of China, Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health , Fudan University , Shanghai , 200032 , China
| | - Songhui Jiang
- Centers for Water and Health, Key Laboratory of Health Technology Assessment, National Health Commission of the People's Republic of China, Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health , Fudan University , Shanghai , 200032 , China
| | - Weimin Ye
- Department of Medical Epidemiology and Biostatistics , Karolinska Institutet , Stockholm , 171 77 , Sweden
| | - Yuxin Zheng
- School of Public Health , Qingdao University , 38 Dengzhou Road , Qingdao , 266021 , China
| | - Weidong Qu
- Centers for Water and Health, Key Laboratory of Health Technology Assessment, National Health Commission of the People's Republic of China, Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health , Fudan University , Shanghai , 200032 , China
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9
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Nakazato A, Kajita K, Ooka M, Akagawa R, Abe T, Takeda S, Branzei D, Hirota K. SPARTAN promotes genetic diversification of the immunoglobulin-variable gene locus in avian DT40 cells. DNA Repair (Amst) 2018; 68:50-57. [PMID: 29935364 DOI: 10.1016/j.dnarep.2018.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 06/12/2018] [Accepted: 06/13/2018] [Indexed: 11/17/2022]
Abstract
Prolonged replication arrest on damaged templates is a cause of fork collapse, potentially resulting in genome instability. Arrested replication is rescued by translesion DNA synthesis (TLS) and homologous recombination (HR)-mediated template switching. SPARTAN, a ubiquitin-PCNA-interacting regulator, regulates TLS via mechanisms incompletely understood. Here we show that SPARTAN promotes diversification of the chicken DT40 immunoglobulin-variable λ gene by facilitating TLS-mediated hypermutation and template switch-mediated gene-conversion, both induced by replication blocks at abasic sites. SPARTAN-/- and SPARTAN-/-/Polη-/-/Polζ-/- cells showed defective and similar decrease in hypermutation rates, as well as alterations in the mutation spectra, with decreased dG-to-dC transversions and increased dG-to-dA transitions. Strikingly, SPARTAN-/- cells also showed reduced template switch-mediated gene-conversion at the immunoglobulin locus, while being proficient in HR-mediated double strand break repair, and sister chromatid recombination. Notably, SPARTAN's ubiquitin-binding zinc-finger 4 domain, but not the PCNA interacting peptide domain or its DNA-binding domain, was specifically required for the promotion of immunoglobulin gene-conversion, while all these three domains were shown to contribute similarly to TLS. In all, our results suggest that SPARTAN mediates TLS in concert with the Polη-Polζ pathway and that it facilitates HR-mediated template switching at a subset of stalled replication forks, potentially by interacting with unknown ubiquitinated proteins.
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Affiliation(s)
- Arisa Nakazato
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Kinumi Kajita
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Masato Ooka
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Remi Akagawa
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Takuya Abe
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan; IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Dana Branzei
- IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy; Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche (IGM-CNR), Via Abbiategrasso 207, 27100, Pavia, Italy.
| | - Kouji Hirota
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan.
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10
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Ooka M, Kobayashi K, Abe T, Akiyama K, Hada M, Takeda S, Hirota K. Determination of genotoxic potential by comparison of structurally related azo dyes using DNA repair-deficient DT40 mutant panels. CHEMOSPHERE 2016; 164:106-112. [PMID: 27580264 DOI: 10.1016/j.chemosphere.2016.08.092] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 07/15/2016] [Accepted: 08/20/2016] [Indexed: 06/06/2023]
Abstract
Azo dyes, including Sudan I, Orange II and Orange G, are industrial dyes that are assumed to have genotoxic potential. However, neither the type of DNA damage induced nor the structural features responsible for toxicity have been determined. We used a panel of DNA-repair-pathway-deficient mutants generated from chicken DT40 cells to evaluate the ability of these azo dyes to induce DNA damage and to identify the type of DNA damage induced. We compared the structurally related azo dyes Sudan I, Orange II and Orange G to identify the structural features responsible for genotoxicity. Compared with wild type cells, the double-strand break repair defective RAD54-/-/KU70-/- cells were significantly more sensitive to Sudan I, but not to Orange II or Orange G. The quantum-chemical calculations revealed that Sudan I, but not Orange II or Orange G, has a complete planar aromatic ring structure. These suggest that the planar feature of Sudan I is critical to the inducing of double-strand breaks. In summary, we used a DNA-repair mutant panel in combination with quantum-chemical calculations to provide a clue to the chemical structure responsible for genotoxicity.
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Affiliation(s)
- Masato Ooka
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Koji Kobayashi
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Takuya Abe
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Kazuhiko Akiyama
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Masahiko Hada
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Kouji Hirota
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan.
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11
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Kobayashi K, Guilliam TA, Tsuda M, Yamamoto J, Bailey LJ, Iwai S, Takeda S, Doherty AJ, Hirota K. Repriming by PrimPol is critical for DNA replication restart downstream of lesions and chain-terminating nucleosides. Cell Cycle 2016; 15:1997-2008. [PMID: 27230014 PMCID: PMC4968974 DOI: 10.1080/15384101.2016.1191711] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/12/2016] [Accepted: 05/14/2016] [Indexed: 01/28/2023] Open
Abstract
PrimPol is a DNA damage tolerance enzyme possessing both translesion synthesis (TLS) and primase activities. To uncover its potential role in TLS-mediated IgVλ hypermutation and define its interplay with other TLS polymerases, PrimPol(-/-) and PrimPol(-/-)/Polη(-/-)/Polζ (-/-) gene knockouts were generated in avian cells. Loss of PrimPol had no significant impact on the rate of hypermutation or the mutation spectrum of IgVλ. However, PrimPol(-/-) cells were sensitive to methylmethane sulfonate, suggesting that it may bypass abasic sites at the IgVλ segment by repriming DNA synthesis downstream of these sites. PrimPol(-/-) cells were also sensitive to cisplatin and hydroxyurea, indicating that it assists in maintaining / restarting replication at a variety of lesions. To accurately measure the relative contribution of the TLS and primase activities, we examined DNA damage sensitivity in PrimPol(-/-) cells complemented with polymerase or primase-deficient PrimPol. Polymerase-defective, but not primase-deficient, PrimPol suppresses the hypersensitivity of PrimPol(-/-) cells. This indicates that its primase, rather than TLS activity, is pivotal for DNA damage tolerance. Loss of TLS polymerases, Polη and Polζ has an additive effect on the sensitivity of PrimPol(-/-) cells. Moreover, we found that PrimPol and Polη-Polζ redundantly prevented cell death and facilitated unperturbed cell cycle progression. PrimPol(-/-) cells also exhibited increased sensitivity to a wide variety of chain-terminating nucleoside analogs (CTNAs). PrimPol could perform close-coupled repriming downstream of CTNAs and oxidative damage in vitro. Together, these results indicate that PrimPol's repriming activity plays a central role in reinitiating replication downstream from CTNAs and other specific DNA lesions.
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Affiliation(s)
- Kaori Kobayashi
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji-shi, Tokyo, Japan
| | - Thomas A. Guilliam
- Genome Damage and Stability Center, School of Life Sciences, University of Sussex, Brighton, UK
| | - Masataka Tsuda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
| | - Junpei Yamamoto
- Division of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, Japan
| | - Laura J. Bailey
- Genome Damage and Stability Center, School of Life Sciences, University of Sussex, Brighton, UK
| | - Shigenori Iwai
- Division of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, Japan
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto, Japan
| | - Aidan J. Doherty
- Genome Damage and Stability Center, School of Life Sciences, University of Sussex, Brighton, UK
| | - Kouji Hirota
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji-shi, Tokyo, Japan
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