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Su B, Lim D, Qi C, Zhang Z, Wang J, Zhang F, Dong C, Feng Z. VPA mediates bidirectional regulation of cell cycle progression through the PPP2R2A-Chk1 signaling axis in response to HU. Cell Death Dis 2023; 14:114. [PMID: 36781846 PMCID: PMC9925808 DOI: 10.1038/s41419-023-05649-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/15/2023]
Abstract
Cell cycle checkpoint kinases play a pivotal role in protecting against replicative stress. In this study, valproic acid (VPA), a histone deacetylase inhibitor (HDACi), was found to promote breast cancer MCF-7 cells to traverse into G2/M phase for catastrophic injury by promoting PPP2R2A (the B-regulatory subunit of Phosphatase PP2A) to facilitate the dephosphorylation of Chk1 at Ser317 and Ser345. By contrast, VPA protected normal 16HBE cells from HU toxicity through decreasing PPP2R2A expression and increasing Chk1 phosphorylation. The effect of VPA on PPP2R2A was at the post-transcription level through HDAC1/2. The in vitro results were affirmed in vivo. Patients with lower PPP2R2A expression and higher pChk1 expression showed significantly worse survival. PPP2R2A D197 and N181 are essential for PPP2R2A-Chk1 signaling and VPA-mediated bidirectional effect on augmenting HU-induced tumor cell death and protecting normal cells.
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Affiliation(s)
- Benyu Su
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - David Lim
- Translational Health Research Institute, School of Health Sciences, Western Sydney University, Campbelltown, NSW, Australia
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Chenyang Qi
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Zhongwei Zhang
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Junxiao Wang
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Fengmei Zhang
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Chao Dong
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China.
| | - Zhihui Feng
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China.
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2
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Alterations in the p53 isoform ratio govern breast cancer cell fate in response to DNA damage. Cell Death Dis 2022; 13:907. [PMID: 36307393 PMCID: PMC9616954 DOI: 10.1038/s41419-022-05349-9] [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: 03/23/2022] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 11/07/2022]
Abstract
Our previous studies have shown that p53 isoform expression is altered in breast cancer and related to prognosis. In particular, a high ∆40p53:p53α ratio is associated with worse disease-free survival. In this manuscript, the influence of altered Δ40p53 and p53α levels on the response to standard of care DNA-damaging agents used in breast cancer treatment was investigated in vitro. Our results revealed that a high Δ40p53:p53α ratio causes cells to respond differently to doxorubicin and cisplatin treatments. Δ40p53 overexpression significantly impairs the cells' sensitivity to doxorubicin through reducing apoptosis and DNA damage, whereas Δ40p53 knockdown has the opposite effect. Further, a high Δ40p53:p53α ratio inhibited the differential expression of several genes following doxorubicin and promoted DNA repair, impairing the cells' canonical response. Overall, our results suggest that the response of breast cancer cells to standard of care DNA-damaging therapies is dependent on the expression of p53 isoforms, which may contribute to outcomes in breast cancer.
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3
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Yao Y, Chen C, Cai Z, Liu G, Ding C, Lim D, Chao D, Feng Z. Screen identifies fasudil as a radioprotector on human fibroblasts. Toxicol Res (Camb) 2022; 11:662-672. [PMID: 36051660 PMCID: PMC9424713 DOI: 10.1093/toxres/tfac042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 06/23/2022] [Accepted: 06/27/2022] [Indexed: 07/24/2023] Open
Abstract
Background Radioprotectors safeguard biological system exposed to ionizing radiation (IR) by protecting normal cells from radiation damage during radiotherapy. Due to the toxicity and limited clinical utility of the present radioprotectors, it prompts us to identify novel radioprotectors that could alleviate IR-induced cytotoxicity of normal tissues. Aims and Methods To identify new radioprotectors, we screened a chemical molecular library comprising 253 compounds in normal human fibroblasts (HFs) or 16HBE cells upon IR by CCK-8 assays and clonogenic survival assays. Fasudil was identified as a potential effective radioprotector. Results The results indicated that Fasudil exerts radioprotective effects on HFs against IR-induced DNA double-strand breaks (DSBs) through the regulation of DSB repair. Fasudil increased homologous recombination (HR) repair by 45.24% and decreased non-homologous end-joining (NHEJ) by 63.88% compared with untreated cells, without affecting changes to cell cycle profile. We further found that fasudil significantly facilitated the expression and foci formation of HR core proteins such as Rad51 and BRCA1 upon IR, and decreased the expression of NHEJ-associated proteins such as DNA-PKcs at 24 h post-IR. Conclusion Our study identified fasudil as a novel radioprotector that exert radioprotective effects on normal cells through regulation of DSB repair by promoting HR repair.
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Affiliation(s)
- Yanling Yao
- Department of Occupational Health and Occupational Medicine, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China
| | - Chen Chen
- Department of Occupational Health and Occupational Medicine, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China
| | - Zuchao Cai
- Department of Occupational Health and Occupational Medicine, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China
| | - Guochao Liu
- Department of Occupational Health and Occupational Medicine, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China
| | - Chenxia Ding
- Department of Occupational Health and Occupational Medicine, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China
| | - David Lim
- Health services Management, School of Science and Health, Translational Health Research Institute, Western Sydney University, Campbelltown 1797, Australia
- College of Medicine and Public Health, Flinders University, Bedford Park 5042, Australia
| | - Dong Chao
- Corresponding author: Department of Occupational Health and Occupational Medicine, The Public Health School, Cheeloo College of Medicine, Shandong University, Shandong, Jinan 250012, China. ;
| | - Zhihui Feng
- Corresponding author: Department of Occupational Health and Occupational Medicine, The Public Health School, Cheeloo College of Medicine, Shandong University, Shandong, Jinan 250012, China. ;
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4
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Hsieh YP, Naler LB, Ma S, Lu C. Cell-type-specific epigenomic variations associated with BRCA1 mutation in pre-cancer human breast tissues. NAR Genom Bioinform 2022; 4:lqac006. [PMID: 35118379 PMCID: PMC8808540 DOI: 10.1093/nargab/lqac006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 12/13/2021] [Accepted: 01/24/2022] [Indexed: 11/24/2022] Open
Abstract
BRCA1 germline mutation carriers are predisposed to breast cancers. Epigenomic regulations have been known to strongly interact with genetic variations and potentially mediate biochemical cascades involved in tumorigenesis. Due to the cell-type specificity of epigenomic features, profiling of individual cell types is critical for understanding the molecular events in various cellular compartments within complex breast tissue. Here, we produced cell-type-specific profiles of genome-wide histone modifications including H3K27ac and H3K4me3 in basal, luminal progenitor, mature luminal and stromal cells extracted from a small pilot cohort of pre-cancer BRCA1 mutation carriers (BRCA1mut/+) and non-carriers (BRCA1+/+), using a low-input ChIP-seq technology that we developed. We discovered that basal and stromal cells present the most extensive epigenomic differences between mutation carriers (BRCA1mut/+) and non-carriers (BRCA1+/+), while luminal progenitor and mature luminal cells are relatively unchanged with the mutation. Furthermore, the epigenomic changes in basal cells due to BRCA1 mutation appear to facilitate their transformation into luminal progenitor cells. Taken together, epigenomic regulation plays an important role in the case of BRCA1 mutation for shaping the molecular landscape that facilitates tumorigenesis.
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Affiliation(s)
- Yuan-Pang Hsieh
- Department of Chemical Engineering, Virginia Tech, Blacksburg, VA 24061, USA
| | - Lynette B Naler
- Department of Chemical Engineering, Virginia Tech, Blacksburg, VA 24061, USA
| | - Sai Ma
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA
| | - Chang Lu
- Department of Chemical Engineering, Virginia Tech, Blacksburg, VA 24061, USA
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Ding C, Su B, Li Q, Ding W, Liu G, Cai Z, Zhang F, Lim D, Feng Z. Histone deacetylase inhibitor 2-hexyl-4-pentynoic acid enhances hydroxyurea therapeutic effect in triple-negative breast cancer cells. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2022; 873:503422. [PMID: 35094806 DOI: 10.1016/j.mrgentox.2021.503422] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 10/07/2021] [Accepted: 11/03/2021] [Indexed: 06/14/2023]
Abstract
Triple-negative breast cancer (TNBC) treatment has only limited effect, and it causes a significant number of deaths. Histone deacetylase inhibitors (HDACis) are emerging as promising anti-tumor agents in many types of cancers. We thus hypothesized that 2-hexyl-4-pentynoic acid (HPTA), a novel HDACi, could sensitize TNBC to hydroxyurea (HU, a ribonucleotide reductase inhibitor). In the present study, we investigated the effect of HPTA, alone or in combination with HU on cell survival, DNA double-strand breaks (DSBs), key homologous recombination (HR) repair proteins and cell cycle progression in MDA-MB-468 and MDA-MB-231 human TNBC cell lines. HPTA and HU synergistically inhibited the survival of TNBC cell lines and resulted in the accumulation of DNA double-strand breaks (DSBs). HPTA can sensitize TNBC cells to HU by inhibiting replication protein A2 (RPA2) hyperphosphorylation-mediated HR repair, and lessen cell accumulation in S-phase by inhibiting ATR-CHK1 signaling pathway. Taken together, our data suggested that HPTA enhances HU therapeutic effect by blocking the HR repair and regulating cell cycle progression in TNBC.
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Affiliation(s)
- Chenxia Ding
- Department of Occupational Health and Occupational Medicine, The Public Health School, Cheeloo College of Medicine, Shandong University, China
| | - Benyu Su
- Department of Occupational Health and Occupational Medicine, The Public Health School, Cheeloo College of Medicine, Shandong University, China
| | | | - Wenwen Ding
- Department of Occupational Health and Occupational Medicine, The Public Health School, Cheeloo College of Medicine, Shandong University, China
| | - Guochao Liu
- Department of Occupational Health and Occupational Medicine, The Public Health School, Cheeloo College of Medicine, Shandong University, China
| | - Zuchao Cai
- Department of Occupational Health and Occupational Medicine, The Public Health School, Cheeloo College of Medicine, Shandong University, China
| | - Fengmei Zhang
- Department of Occupational Health and Occupational Medicine, The Public Health School, Cheeloo College of Medicine, Shandong University, China
| | - David Lim
- School of Health Sciences, Western Sydney University, Campbelltown, New South Wales, Australia; Translational Health Research Institute, Western Sydney University, Campbelltown, New South Wales, Australia
| | - Zhihui Feng
- Department of Occupational Health and Occupational Medicine, The Public Health School, Cheeloo College of Medicine, Shandong University, China.
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6
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Yu R, Sun T, Zhang X, Li Z, Xu Y, Liu K, Shi Y, Wu X, Shao Y, Kong L. TP53 Co-Mutational Features and NGS-Calibrated Immunohistochemistry Threshold in Gastric Cancer. Onco Targets Ther 2021; 14:4967-4978. [PMID: 34629881 PMCID: PMC8493115 DOI: 10.2147/ott.s321949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 09/17/2021] [Indexed: 12/24/2022] Open
Abstract
Purpose TP53 is the most frequently mutated gene in gastric cancer and it can be potentially used for gastric cancer diagnosis and screening. However, standardized clinical approaches that could accurately and cost-effectively detect TP53 mutations in gastric cancer are largely lagged behind. Patients and Methods We conducted next-generation sequencing (NGS) analysis of 425 cancer-related genes in 42 gastric cancer patients in our cohort. A 1313-patient cohort derived from the cBioPortal database was used for validation. We performed immunohistochemistry (IHC) staining with four commonly used p53 antibodies, and the NGS results were used as the gold standard to optimize the IHC threshold for each antibody. Results By NGS analysis, we found that around 80% of gastric cancer patients in our cohort harbored TP53 alterations. Genetic alterations of BRCA1/2 or KMT2B were mostly exclusive with TP53 mutations, so were the MSI status or low grade of tumors. These results were further validated using the data from cBioPortal. We then used the NGS-derived TP53 status to optimize four commonly used IHC antibodies for detecting TP53 mutations. We showed that all antibodies could achieve more than 93% accuracy when proper IHC positivity thresholds were used, especially for the SP5 antibody that could reach 100% sensitivity and specificity with the 20% threshold. Conclusion Our results indicated that exclusivity between TP53 and BRCA mutations could be potentially used as a cost-effective way to predict BRCA status. Also, setting proper IHC thresholds for each specific antibody is critical to accurately detect TP53 mutations and facilitate disease diagnosis.
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Affiliation(s)
- Ruili Yu
- Department of Pathology, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, Henan, People's Republic of China
| | - Tingyi Sun
- Department of Pathology, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, Henan, People's Republic of China
| | - Xianwei Zhang
- Department of Pathology, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, Henan, People's Republic of China
| | - Zhen Li
- Department of Pathology, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, Henan, People's Republic of China
| | - Yang Xu
- Geneseeq Research Institute, Nanjing Geneseeq Technology Inc., Nanjing, Jiangsu, People's Republic of China
| | - Kaihua Liu
- Geneseeq Research Institute, Nanjing Geneseeq Technology Inc., Nanjing, Jiangsu, People's Republic of China
| | - Yuqian Shi
- Geneseeq Research Institute, Nanjing Geneseeq Technology Inc., Nanjing, Jiangsu, People's Republic of China
| | - Xue Wu
- Geneseeq Research Institute, Nanjing Geneseeq Technology Inc., Nanjing, Jiangsu, People's Republic of China
| | - Yang Shao
- Geneseeq Research Institute, Nanjing Geneseeq Technology Inc., Nanjing, Jiangsu, People's Republic of China.,School of Public Health, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Lingfei Kong
- Department of Pathology, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, Henan, People's Republic of China
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7
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Su B, Lim D, Tian Z, Liu G, Ding C, Cai Z, Chen C, Zhang F, Feng Z. Valproic Acid Regulates HR and Cell Cycle Through MUS81-pRPA2 Pathway in Response to Hydroxyurea. Front Oncol 2021; 11:681278. [PMID: 34513672 PMCID: PMC8429838 DOI: 10.3389/fonc.2021.681278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/30/2021] [Indexed: 12/24/2022] Open
Abstract
Breast cancer is the primary problem threatening women’s health. The combined application of valproic acid (VPA) and hydroxyurea (HU) has a synergistic effect on killing breast cancer cells, but the molecular mechanism remains elusive. Replication protein A2 phosphorylation (pRPA2), is essential for homologous recombination (HR) repair and cell cycle. Here we showed that in response to HU, the VPA significantly decreased the tumor cells survival, and promoted S-phase slippage, which was associated with the decrease of pCHK1 and WEE1/pCDK1-mediated checkpoint kinases phosphorylation pathway and inhibited pRPA2/Rad51-mediated HR repair pathway; the mutation of pRPA2 significantly diminished the above effect, indicating that VPA-caused HU sensitization was pRPA2 dependent. It was further found that VPA and HU combination treatment also resulted in the decrease of endonuclease MUS81. After MUS81 elimination, not only the level of pRPA2 was abolished in response to HU treatment, but also VPA-caused HU sensitization was significantly down-regulated through pRPA2-mediated checkpoint kinases phosphorylation and HR repair pathways. In addition, the VPA altered the tumor microenvironment and reduced tumor burden by recruiting macrophages to tumor sites; the Kaplan-Meier analysis showed that patients with high pRPA2 expression had significantly worse survival. Overall, our findings demonstrated that VPA influences HR repair and cell cycle through down-regulating MUS81-pRPA2 pathway in response to HU treatment.
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Affiliation(s)
- Benyu Su
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - David Lim
- School of Health Sciences, Western Sydney University, Campbelltown, NSW, Australia.,College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Zhujun Tian
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China.,School of Public Health and Management, Wenzhou Medical University, Wenzhou, China
| | - Guochao Liu
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Chenxia Ding
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Zuchao Cai
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Chen Chen
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Fengmei Zhang
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Zhihui Feng
- Department of Occupational and Environmental Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
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8
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Liu G, Lim D, Cai Z, Ding W, Tian Z, Dong C, Zhang F, Guo G, Wang X, Zhou P, Feng Z. The Valproate Mediates Radio-Bidirectional Regulation Through RFWD3-Dependent Ubiquitination on Rad51. Front Oncol 2021; 11:646256. [PMID: 33842359 PMCID: PMC8029989 DOI: 10.3389/fonc.2021.646256] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 03/08/2021] [Indexed: 12/23/2022] Open
Abstract
Ionizing radiation (IR) can induce DNA double-strand breaks (DSBs) in tumor cells during radiotherapy (RT), but the efficiency of RT is limited because of the toxicity to normal cells. Locating an adjuvant treatment to alleviate damage in normal cells while sensitizing tumor cells to IR has attracted much attention. Here, using the 7,12-dimethylbenz[α]anthracene (DMBA)-induced malignant transformed MCF10A cells, we found that valproate (VPA), a histone deacetylase inhibitor (HDACi), radiosensitized transformed cells while alleviated IR-induced damage in normal cells at a safe dose (0.5 mM). We further demonstrated the decrease of homologous recombination (HR)-associated Rad51 in the transformed cells was related to the increase of its ubiquitination regulated by E3 ligase RFWD3 for the radiosensitization, which was opposite to normal cells, indicating that RFWD3-dependent ubiquitination on Rad51 was involved in the VPA-mediated radio-bidirectional effect. Through DMBA-transformed breast cancer rat model, VPA at 200 mg/kg radiosensitized tumor tissue cells by increasing RFWD3 and inhibited Rad51, while radioprotected normal tissue cells by decreasing RFWD3 and enhanced Rad51. In addition, we found high-level Rad51 was associated with tumorigenesis and poor prognosis in breast cancer patients. Our findings uncovered RFWD3-dependent Rad51 ubiquitination was the novel mechanism of VPA-mediated radio-bidirectional effect, VPA is a potential adjuvant treatment for tumor RT.
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Affiliation(s)
- Guochao Liu
- Department of Occupational Health and Occupational Medicine, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - David Lim
- School of Health Sciences, Western Sydney University, Campbelltown, NSW, Australia.,College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Zuchao Cai
- Department of Occupational Health and Occupational Medicine, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Wenwen Ding
- Department of Occupational Health and Occupational Medicine, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Zhujun Tian
- Department of Occupational Health and Occupational Medicine, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Chao Dong
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Fengmei Zhang
- Department of Occupational Health and Occupational Medicine, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Gongshe Guo
- Department of Medicine, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Xiaowei Wang
- Department of Radiation Oncology, Washington University, School of Medicine, St. Louis, MO, United States
| | - Pingkun Zhou
- Beijing Key Laboratory for Radiobiology, Department of Radiation Biology, Beijing Institute of Radiation Medicine, AMMS, Beijing, China
| | - Zhihui Feng
- Department of Occupational Health and Occupational Medicine, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
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2-hexyl-4-pentynoic acid, a potential therapeutic for breast carcinoma by influencing RPA2 hyperphosphorylation-mediated DNA repair. DNA Repair (Amst) 2020; 95:102940. [PMID: 32795962 DOI: 10.1016/j.dnarep.2020.102940] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 07/19/2020] [Accepted: 07/24/2020] [Indexed: 12/31/2022]
Abstract
Breast carcinoma is one of the most common malignancies in women. Previous studies have reported that 500 μM valproic acid can sensitize breast tumor cells to the anti-neoplastic agent hydroxyurea. However, the dose requirements for valproic acid is highly variable due to the wide inter-individuals clinical characteristics. High therapeutic dose of valproic acid required to induce anti-tumor activity in solid tumor was associated with increased adverse effects. There are attempts to locate suitably high-efficient low-toxicity valproic acid derivatives. We demonstrated that lower dose of 2-hexyl-4-pentynoic acid (HPTA; 15 μM) has similar effects as 500 μM VPA in inhibiting breast cancer cell growth and sensitizing the tumor cells to hydroxyurea on MCF7 cells, EUFA423 cells, MCF7 cells with defective RPA2-p gene and primary culture cells derived from tissue-transformed breast tumor cells. We discovered HPTA resulted in more DNA double-strand breaks, the homologous recombination was inhibited through the interference of the hyperphosphorylation of replication protein A2 and recombinase Rad51. Our data postulate that HPTA may be a potential novel sensitizer to hydroxyurea in the treatment of breast carcinoma.
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10
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Ji Z, Wang B, Yan K, Dong L, Meng G, Shi L. A linear programming computational framework integrates phosphor-proteomics and prior knowledge to predict drug efficacy. BMC SYSTEMS BIOLOGY 2017; 11:127. [PMID: 29322918 PMCID: PMC5763468 DOI: 10.1186/s12918-017-0501-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Background In recent years, the integration of ‘omics’ technologies, high performance computation, and mathematical modeling of biological processes marks that the systems biology has started to fundamentally impact the way of approaching drug discovery. The LINCS public data warehouse provides detailed information about cell responses with various genetic and environmental stressors. It can be greatly helpful in developing new drugs and therapeutics, as well as improving the situations of lacking effective drugs, drug resistance and relapse in cancer therapies, etc. Results In this study, we developed a Ternary status based Integer Linear Programming (TILP) method to infer cell-specific signaling pathway network and predict compounds’ treatment efficacy. The novelty of our study is that phosphor-proteomic data and prior knowledge are combined for modeling and optimizing the signaling network. To test the power of our approach, a generic pathway network was constructed for a human breast cancer cell line MCF7; and the TILP model was used to infer MCF7-specific pathways with a set of phosphor-proteomic data collected from ten representative small molecule chemical compounds (most of them were studied in breast cancer treatment). Cross-validation indicated that the MCF7-specific pathway network inferred by TILP were reliable predicting a compound’s efficacy. Finally, we applied TILP to re-optimize the inferred cell-specific pathways and predict the outcomes of five small compounds (carmustine, doxorubicin, GW-8510, daunorubicin, and verapamil), which were rarely used in clinic for breast cancer. In the simulation, the proposed approach facilitates us to identify a compound’s treatment efficacy qualitatively and quantitatively, and the cross validation analysis indicated good accuracy in predicting effects of five compounds. Conclusions In summary, the TILP model is useful for discovering new drugs for clinic use, and also elucidating the potential mechanisms of a compound to targets. Electronic supplementary material The online version of this article (10.1186/s12918-017-0501-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zhiwei Ji
- School of Electronical and Information Engineering, Anhui University of Technology, Maanshan, 243002, China. .,School of Information & Electronic Engineering, Zhejiang Gongshang University, 18 Xuezheng Road, Hangzhou, 310018, China.
| | - Bing Wang
- School of Electronical and Information Engineering, Anhui University of Technology, Maanshan, 243002, China.
| | - Ke Yan
- College of Information Engineering, China Jiliang University, 258 Xueyuan Streat, Hangzhou, 310018, China
| | - Ligang Dong
- School of Information & Electronic Engineering, Zhejiang Gongshang University, 18 Xuezheng Road, Hangzhou, 310018, China
| | - Guanmin Meng
- Department of Clinical Laboratory, Tongde Hospital of Zhejiang Province, 234 Gucui Road, Hangzhou, 310012, China
| | - Lei Shi
- School of Information & Electronic Engineering, Zhejiang Gongshang University, 18 Xuezheng Road, Hangzhou, 310018, China
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11
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RAD51 Is a Selective DNA Repair Target to Radiosensitize Glioma Stem Cells. Stem Cell Reports 2017; 8:125-139. [PMID: 28076755 PMCID: PMC5233453 DOI: 10.1016/j.stemcr.2016.12.005] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 12/05/2016] [Accepted: 12/05/2016] [Indexed: 11/27/2022] Open
Abstract
Patients with glioblastoma die from local relapse despite surgery and high-dose radiotherapy. Resistance to radiotherapy is thought to be due to efficient DNA double-strand break (DSB) repair in stem-like cells able to survive DNA damage and repopulate the tumor. We used clinical samples and patient-derived glioblastoma stem cells (GSCs) to confirm that the DSB repair protein RAD51 is highly expressed in GSCs, which are reliant on RAD51-dependent DSB repair after radiation. RAD51 expression and RAD51 foci numbers fall when these cells move toward astrocytic differentiation. In GSCs, the small-molecule RAD51 inhibitors RI-1 and B02 prevent RAD51 focus formation, reduce DNA DSB repair, and cause significant radiosensitization. We further demonstrate that treatment with these agents combined with radiation promotes loss of stem cells defined by SOX2 expression. This indicates that RAD51-dependent repair represents an effective and specific target in GSCs. RAD51 is overexpressed in glioma stem cells RAD51 expression levels fall when GSCs are differentiated RAD51 inhibitors abrogate DNA repair leading to radiosensitization in GSCs RAD51 inhibition + XR removes SOX2-expressing cells and abolishes clonogenicity
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Yang JX, Chaudhry MT, Yao JY, Wang SN, Zhou B, Wang M, Han CY, You Y, Li Y. Effects of phyto-oestrogen quercetin on productive performance, hormones, reproductive organs and apoptotic genes in laying hens. J Anim Physiol Anim Nutr (Berl) 2017; 102:505-513. [PMID: 28986927 DOI: 10.1111/jpn.12778] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 06/06/2017] [Indexed: 12/26/2022]
Abstract
Quercetin, a polyphenolic flavonoid with diverse biological activities including anti-inflammatory and antiviral, inhibits lipid peroxidation, prevents oxidative injury and cell death. The purpose of the research was to investigate the effect of quercetin on productive performance, reproductive organs, hormones and apoptotic genes in laying hens between 37 and 45 weeks of age, because of the structure and oestrogenic activities similar to 17β-oestradiol. The trial was conducted using 240 Hessian laying hens (37 weeks old), housed in wire cages with two hens in each cage. These hens were randomly allotted to four treatments with six replicates, 10 hens in each replicate and fed with diets containing quercetin as 0, 0.2, 0.4 and 0.6 g/kg feed for 8 weeks. The results showed that dietary quercetin significantly increased (p < .05) the laying rate and was higher in group supplemented with 0.4 g/kg, and feed-egg ratio was decreased (p < .05) by quercetin. Dietary quercetin has no effect (p > .05) on average egg weight and average daily feed intake. Compared with control, secretion of hormones, oestradiol (E2 ), progesterone (P4), follicle-stimulating hormone (FSH), luteinizing hormone (LH), insulin-like growth factors-1 (IGF-1) and growth hormone (GH), was found to be significantly higher (p < .05) in quercetin-supplemented groups. Also ovary index, uterus index and oviduct index were not significantly influenced (p > .05) by quercetin, whereas magnum index, isthmus index, magnum length, isthmus length and follicle numbers were significantly increased (p < .05) with quercetin supplementation. Additionally, expression of apoptotic genes was significantly (p < .05) up-regulated or down-regulated by quercetin. These results indicated that quercetin improved productive performance, and its mechanism may be due to the oestrogen-like activities of quercetin.
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Affiliation(s)
- J X Yang
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, Heilongjiang Province, China
| | - M T Chaudhry
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, Heilongjiang Province, China
| | - J Y Yao
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, Heilongjiang Province, China
| | - S N Wang
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, Heilongjiang Province, China
| | - B Zhou
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, Heilongjiang Province, China
| | - M Wang
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, Heilongjiang Province, China
| | - C Y Han
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, Heilongjiang Province, China
| | - Y You
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, Heilongjiang Province, China
| | - Y Li
- Institute of Animal Nutrition, Northeast Agricultural University, Harbin, Heilongjiang Province, China
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Valproic acid sensitizes breast cancer cells to hydroxyurea through inhibiting RPA2 hyperphosphorylation-mediated DNA repair pathway. DNA Repair (Amst) 2017; 58:1-12. [DOI: 10.1016/j.dnarep.2017.08.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 06/28/2017] [Accepted: 08/07/2017] [Indexed: 11/24/2022]
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Liu G, Wang H, Zhang F, Tian Y, Tian Z, Cai Z, Lim D, Feng Z. The Effect of VPA on Increasing Radiosensitivity in Osteosarcoma Cells and Primary-Culture Cells from Chemical Carcinogen-Induced Breast Cancer in Rats. Int J Mol Sci 2017; 18:ijms18051027. [PMID: 28489060 PMCID: PMC5454939 DOI: 10.3390/ijms18051027] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 04/30/2017] [Accepted: 05/05/2017] [Indexed: 12/22/2022] Open
Abstract
This study explored whether valproic acid (VPA, a histone deacetylase inhibitor) could radiosensitize osteosarcoma and primary-culture tumor cells, and determined the mechanism of VPA-induced radiosensitization. The working system included osteosarcoma cells (U2OS) and primary-culture cells from chemical carcinogen (DMBA)-induced breast cancer in rats; and clonogenic survival, immunofluorescence, fluorescent in situ hybridization (FISH) for chromosome aberrations, and comet assays were used in this study. It was found that VPA at the safe or critical safe concentration of 0.5 or 1.0 mM VPA could result in the accumulation of more ionizing radiation (IR)-induced DNA double strand breaks, and increase the cell radiosensitivity. VPA-induced radiosensitivity was associated with the inhibition of DNA repair activity in the working systems. In addition, the chromosome aberrations including chromosome breaks, chromatid breaks, and radial structures significantly increased after the combination treatment of VPA and IR. Importantly, the results obtained by primary-culture cells from the tissue of chemical carcinogen-induced breast cancer in rats further confirmed our findings. The data in this study demonstrated that VPA at a safe dose was a radiosensitizer for osteosarcoma and primary-culture tumor cells through suppressing DNA-double strand breaks repair function.
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Affiliation(s)
- Guochao Liu
- Department of Occupational Health and Occupational Medicine, School of Public Health, Shandong University, Jinan 250012, China.
| | - Hui Wang
- Department of Occupational Health and Occupational Medicine, School of Public Health, Shandong University, Jinan 250012, China.
| | - Fengmei Zhang
- Department of Occupational Health and Occupational Medicine, School of Public Health, Shandong University, Jinan 250012, China.
| | - Youjia Tian
- Department of Occupational Health and Occupational Medicine, School of Public Health, Shandong University, Jinan 250012, China.
| | - Zhujun Tian
- Department of Occupational Health and Occupational Medicine, School of Public Health, Shandong University, Jinan 250012, China.
| | - Zuchao Cai
- Department of Occupational Health and Occupational Medicine, School of Public Health, Shandong University, Jinan 250012, China.
| | - David Lim
- Flinders Rural Health South Australia, Victor Harbor, SA 5211, Australia.
| | - Zhihui Feng
- Department of Occupational Health and Occupational Medicine, School of Public Health, Shandong University, Jinan 250012, China.
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Ciccarese C, Massari F, Blanca A, Tortora G, Montironi R, Cheng L, Scarpelli M, Raspollini MR, Vau N, Fonseca J, Lopez-Beltran A. Tp53 and its potential therapeutic role as a target in bladder cancer. Expert Opin Ther Targets 2017; 21:401-414. [PMID: 28281901 DOI: 10.1080/14728222.2017.1297798] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Despite more than 30 years of research on p53 resulting in >50,000 publications, we are now beginning to figure out the complexity of the p53 pathway, gene ontology and conformational structure of the molecule. Recent years brought great advances in p53 related drugs and the potencial ways in which p53 is inactivated in cancer. Areas covered: We searched for related publications on Pubmed and ClinicalTrial.gov using the following keywords 'p53, Tp53, p53 and bladder cancer, p53 and therapeutic target'. Relevant articles improved the understanding on p53 pathways and their potential as candidate to targeted therapy in bladder cancer. Expert opinion: Novel strategies developed to restore the function of mutants with chemical chaperones or by using compounds to improved pharmacokinetic properties are in development with potential to be applied in the oncology clinic. Other strategies targeting aberrantly overexpressed p53 regulators with wild-type p53 are also an active area of research. In particular, studies inhibiting the interaction of p53 with its negative regulators MDMX and MDM2 are an important field in drug discovery. Small molecules for inhibition of MDM2 are now in clinical trials process. However, personalized anticancer therapy might eventually advance through analyses of p53 status in cancer patients.
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Affiliation(s)
- Chiara Ciccarese
- a Medical Oncology, Azienda Ospedaliera Universitaria Integrata , University of Verona , Verona , Italy
| | - Francesco Massari
- b Medical Oncology , Azienda Ospedaliera Universitaria Integrata (A.O.U.I.) , Verona , Italy
| | - Ana Blanca
- c Maimonides Biomedical Research Institute of Cordoba, Spain - Urology Department , Reina Sofía Hospital , Córdoba , Spain
| | - Giampaolo Tortora
- d Medical Oncology dU, Policlinico 'G.B. Rossi' , University of Verona , Verona , Italy
| | - Rodolfo Montironi
- e Pathological Anatomy , Polytechnic University of the Marche Region, School of Medicine, United Hospitals , Ancona , Italy
| | - Liang Cheng
- f Department of Pathology and Laboratory Medicine , Indiana University School of Medicine , Indianapolis , IN 46202 , USA
| | - Marina Scarpelli
- e Pathological Anatomy , Polytechnic University of the Marche Region, School of Medicine, United Hospitals , Ancona , Italy
| | - Maria R Raspollini
- g Histopathology and Molecular Diagnostics Service , Careggi University Hospital Florence , Florence , Italy
| | - Nuno Vau
- h Medical Oncology , Champalimaud Clinical Center , Lisbon , Portugal
| | - Jorge Fonseca
- i Urology service , Champalimaud Clinical Center , Lisbon , Portugal
| | - Antonio Lopez-Beltran
- j Department of Surgery and Pathology , Cordoba University Medical School, Cordoba, Spain and Champalimaud Clinical Center , Lisbon , Portugal
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Assessing the Effect of Class I Histone Deacetylase Activity on DNA Double-Strand Break Repair by Homologous Recombination. Methods Mol Biol 2017; 1510:115-123. [PMID: 27761817 DOI: 10.1007/978-1-4939-6527-4_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Here we describe the method used in our laboratory for determining the activity of homologous recombination repair of DNA double-strand breaks in cell lines. This plasmid-based method, first published by Pierce et al. 1999 from Maria Jasin's laboratory, is used along with flow cytometry for demonstrating the positive regulation of class I histone deacetylases on the repair of DNA double-strand breaks by homologous recombination.
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Low GM, Thylur DS, Yamamoto V, Sinha UK. The effect of human papillomavirus on DNA repair in head and neck squamous cell carcinoma. Oral Oncol 2016; 61:27-30. [PMID: 27688101 DOI: 10.1016/j.oraloncology.2016.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 08/02/2016] [Accepted: 08/05/2016] [Indexed: 02/08/2023]
Abstract
Much of the current literature regarding the molecular pathophysiology of human papillomavirus (HPV) in head and neck squamous cell carcinoma (HNSCC) has focused on the virus's effect on cell cycle modulation and cell proliferation. A second mechanism of pathogenicity employed by HPV, dysregulation of cellular DNA repair processes, has been more sparsely studied. The purpose of this review is to describe current understanding about the effect of HPV on DNA repair in HNSCC, taking cues from cervical cancer literature. HPV affects DNA-damage response pathways by interacting with many proteins, including ATM, ATR, MRN, γ-H2AX, Chk1, Chk2, p53, BRCA1, BRCA2, RAD51, Rb-related proteins 107 and 130, Tip60, and p16INK4A. Further elucidation of these pathways could lead to development of targeted therapies and improvement of current treatment protocols.
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Affiliation(s)
- Garren M Low
- USC Tina and Rick Caruso Department of Otolaryngology-Head & Neck Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States.
| | - David S Thylur
- USC Tina and Rick Caruso Department of Otolaryngology-Head & Neck Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States.
| | - Vicky Yamamoto
- USC Tina and Rick Caruso Department of Otolaryngology-Head & Neck Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States.
| | - Uttam K Sinha
- USC Tina and Rick Caruso Department of Otolaryngology-Head & Neck Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States.
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Peng L, Xu T, Long T, Zuo H. Association Between BRCA Status and P53 Status in Breast Cancer: A Meta-Analysis. Med Sci Monit 2016; 22:1939-45. [PMID: 27272763 PMCID: PMC4917318 DOI: 10.12659/msm.896260] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background Research on BRCA mutation has meaningful clinical implications, such as identifying risk of second primary cancers and risk of hereditary cancers. This study seeks to summarize available data to investigate the association between BRCA status and P53 status by meta-analysis. Material/Methods We searched PubMed, Embase, and Cochrane library databases for relevant studies. Meta-analysis was conducted using STATA software. We summarized odds ratios by fixed-effects or random-effects models. Results This study included a total of 4288 cases from 16 articles, which including 681 BRCA1 mutation carriers (BRCA1Mut), 366 carriers of BRCA2 mutation (BRCA2Mut), and 3241 carriers of normal versions of these genes. BRCA1Mut was significantly associated with P53 over-expression compared with BRCA2Mut (OR 1.851, 95% CI=1.393–2.458) or non-carriers (OR=2.503, 95% CI=1.493–4.198). No difference was found between p53 protein expression in BRCA2 Mut carriers and non-carriers (OR=0.881, 95% CI=0.670–1.158). Conclusions Our meta-analysis suggests that BRCA1Mut breast cancer patients are more likely to have P53 overexpression compared with BRCA2Mut and non-carriers. This information provides valuable information for clinicians who perform related studies in the future.
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Affiliation(s)
- Lin Peng
- Department of Breast Surgery, Affiliated Hospital of Luzhpu Medical College, Luzhou, Sichuan, China (mainland)
| | - Tao Xu
- Department of Neurosurgery, The Traditional Chinese Medicine (TCM) Hospital Affiliated with Sichuan Medical University, Luzhou, Sichuan, China (mainland)
| | - Ting Long
- Department of Internal Medicine-Neurology, Affiliated Hospital of Luzhou Medical College, Luzhou, Sichuan, China (mainland)
| | - Huaiquan Zuo
- Department of Breast Surgery, Affiliated Hospital of Luzhpu Medical College, Luzhou, Sichuan, China (mainland)
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Cheng YW, Lin FCF, Chen CY, Hsu NY. Environmental exposure and HPV infection may act synergistically to induce lung tumorigenesis in nonsmokers. Oncotarget 2016; 7:19850-62. [PMID: 26918347 PMCID: PMC4991423 DOI: 10.18632/oncotarget.7628] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 02/16/2016] [Indexed: 11/25/2022] Open
Abstract
Most studies of lung tumorigenesis have focused on smokers rather than nonsmokers. In this study, we used human papillomavirus (HPV)-positive and HPV-negative lung cancer cells to test the hypothesis that HPV infection synergistically increases DNA damage induced by exposure to the carcinogen benzo[a]pyrene (B[a]P), and contributes to lung tumorigenesis in nonsmokers. DNA adduct levels induced by B[a]P in HPV-positive cells were significantly higher than in HPV-negative cells. The DNA adduct formation was dependent on HPV E6 oncoprotein expression. Gene and protein expression of two DNA repair genes, XRCC3 and XRCC5, were lower in B[a]P-treated E6-positive cells than in E6-negative lung cancer cells. The reduced expression was also detected immunohistochemically and was caused by increased promoter hypermethylation. Moreover, mutations of p53 and epidermal growth factor receptor (EGFR) genes in lung cancer patients were associated with XRCC5 inactivation. In sum, our study indicates that HPV E6-induced promoter hypermethylation of the XRCC3 and XRCC5 DNA repair genes and the resultant decrease in their expression increases B[a]P-induced DNA adducts and contributes to lung tumorigenesis in nonsmokers.
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Affiliation(s)
- Ya-Wen Cheng
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
- Cancer Center, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan
| | - Frank Cheau-Feng Lin
- School of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Department of Surgery, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Chih-Yi Chen
- School of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Department of Surgery, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Nan-Yung Hsu
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
- Cancer Center, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan
- Department of Surgery, Taipei Medical University Hospital, Taipei, Taiwan
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Luo Y, Wang H, Zhao X, Dong C, Zhang F, Guo G, Guo G, Wang X, Powell SN, Feng Z. Valproic acid causes radiosensitivity of breast cancer cells via disrupting the DNA repair pathway. Toxicol Res (Camb) 2016; 5:859-870. [PMID: 30090395 DOI: 10.1039/c5tx00476d] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 02/16/2016] [Indexed: 11/21/2022] Open
Abstract
Valproic acid (VPA) is one of the representative compounds of histone deacetylase inhibitors (HDACis) and is used widely for the clinical treatment of epilepsy and other convulsive diseases. Current reports indicate that HDACis may also be an attractive radiosensitizer for some tumor cells; however, it is unknown whether the safe blood concentration of VPA (0.3-0.8 mM) used for the treatment of epilepsy can also induce radiosensitivity in breast cancer cells. In addition, the mechanism by which VPA may induce radiosensitivity in breast cancer cells is yet to be determined. Our results clearly indicated that VPA at a safe dose (0.5 mM) could significantly increase the radiosensitivity of MCF7 breast cancer cells and result in more accumulation of DNA double strand breaks in response to DNA damage. After VPA treatment, the frequencies of homologous recombination (HR) and non-homologous end joining (NHEJ) tested by recombination substrates, pDR-GFP and EJ5-GFP, were dramatically decreased in the cells without the change of the cell cycle profile. It was further found that VPA could inhibit the recruitment of key repair proteins to DNA break areas, such as Rad51, BRCA1, and Ku80. Thus, our results demonstrated that a safe dose of VPA causes radiosensitivity in breast cancer cells through disrupting the molecular mechanisms of both BRCA1-Rad51-mediated HR and Ku80-mediated NHEJ pathways.
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Affiliation(s)
- Yue Luo
- Department of Occupational Health and Occupational Medicine , The Public Health School , Shandong University , Shandong , Jinan , China .
| | - Hui Wang
- Department of Occupational Health and Occupational Medicine , The Public Health School , Shandong University , Shandong , Jinan , China .
| | - Xipeng Zhao
- Department of Occupational Health and Occupational Medicine , The Public Health School , Shandong University , Shandong , Jinan , China .
| | - Chao Dong
- Department of Occupational Health and Occupational Medicine , The Public Health School , Shandong University , Shandong , Jinan , China .
| | - Fengmei Zhang
- Department of Occupational Health and Occupational Medicine , The Public Health School , Shandong University , Shandong , Jinan , China .
| | - Gang Guo
- Image Center , Jinan Third People's Hospital , Shandong Province , Shandong , Jinan , China
| | - Gongshe Guo
- The Second Hospital of Shandong University , Shandong , Jinan , China
| | - Xiaowei Wang
- Department of Radiation Oncology , Washington University School of Medicine , St. Louis , USA
| | - Simon N Powell
- Department of Radiation Oncology and Molecular Biology Program , Memorial Sloan Kettering Cancer Center , New York , USA
| | - Zhihui Feng
- Department of Occupational Health and Occupational Medicine , The Public Health School , Shandong University , Shandong , Jinan , China .
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