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Yedla P, Bhamidipati P, Syed R, Amanchy R. Working title: Molecular involvement of p53-MDM2 interactome in gastrointestinal cancers. Cell Biochem Funct 2024; 42:e4075. [PMID: 38924101 DOI: 10.1002/cbf.4075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 05/30/2024] [Accepted: 06/04/2024] [Indexed: 06/28/2024]
Abstract
The interaction between murine double minute 2 (MDM2) and p53, marked by transcriptional induction and feedback inhibition, orchestrates a functional loop dictating cellular fate. The functional loop comprising p53-MDM2 axis is made up of an interactome consisting of approximately 81 proteins, which are spatio-temporally regulated and involved in DNA repair mechanisms. Biochemical and genetic alterations of the interactome result in dysregulation of the p53-mdm2 axis that leads to gastrointestinal (GI) cancers. A large subset of interactome is well known and it consists of proteins that either stabilize p53 or MDM2 and proteins that target the p53-MDM2 complex for ubiquitin-mediated destruction. Upstream signaling events brought about by growth factors and chemical messengers invoke a wide variety of posttranslational modifications in p53-MDM2 axis. Biochemical changes in the transactivation domain of p53 impact the energy landscape, induce conformational switching, alter interaction potential and could change solubility of p53 to redefine its co-localization, translocation and activity. A diverse set of chemical compounds mimic physiological effectors and simulate biochemical modifications of the p53-MDM2 interactome. p53-MDM2 interactome plays a crucial role in DNA damage and repair process. Genetic aberrations in the interactome, have resulted in cancers of GI tract (pancreas, liver, colorectal, gastric, biliary, and esophageal). We present in this article a review of the overall changes in the p53-MDM2 interactors and the effectors that form an epicenter for the development of next-generation molecules for understanding and targeting GI cancers.
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Affiliation(s)
- Poornachandra Yedla
- Division of Applied Biology, CSIR-IICT (Indian Institute of Chemical Technology), Ministry of Science and Technology (GOI), Hyderabad, Telangana, India
- Department of Pharmacogenomics, Institute of Translational Research, Asian Healthcare Foundation, Hyderabad, Telangana, India
| | - Pranav Bhamidipati
- Division of Applied Biology, CSIR-IICT (Indian Institute of Chemical Technology), Ministry of Science and Technology (GOI), Hyderabad, Telangana, India
- Department of Life Sciences, Imperial College London, London, UK
| | - Riyaz Syed
- Division of Applied Biology, CSIR-IICT (Indian Institute of Chemical Technology), Ministry of Science and Technology (GOI), Hyderabad, Telangana, India
| | - Ramars Amanchy
- Division of Applied Biology, CSIR-IICT (Indian Institute of Chemical Technology), Ministry of Science and Technology (GOI), Hyderabad, Telangana, India
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2
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Alva R, Mirza M, Baiton A, Lazuran L, Samokysh L, Bobinski A, Cowan C, Jaimon A, Obioru D, Al Makhoul T, Stuart JA. Oxygen toxicity: cellular mechanisms in normobaric hyperoxia. Cell Biol Toxicol 2022; 39:111-143. [PMID: 36112262 PMCID: PMC9483325 DOI: 10.1007/s10565-022-09773-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 09/07/2022] [Indexed: 12/15/2022]
Abstract
In clinical settings, oxygen therapy is administered to preterm neonates and to adults with acute and chronic conditions such as COVID-19, pulmonary fibrosis, sepsis, cardiac arrest, carbon monoxide poisoning, and acute heart failure. In non-clinical settings, divers and astronauts may also receive supplemental oxygen. In addition, under current standard cell culture practices, cells are maintained in atmospheric oxygen, which is several times higher than what most cells experience in vivo. In all the above scenarios, the elevated oxygen levels (hyperoxia) can lead to increased production of reactive oxygen species from mitochondria, NADPH oxidases, and other sources. This can cause cell dysfunction or death. Acute hyperoxia injury impairs various cellular functions, manifesting ultimately as physiological deficits. Chronic hyperoxia, particularly in the neonate, can disrupt development, leading to permanent deficiencies. In this review, we discuss the cellular activities and pathways affected by hyperoxia, as well as strategies that have been developed to ameliorate injury.
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Affiliation(s)
- Ricardo Alva
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Maha Mirza
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Adam Baiton
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Lucas Lazuran
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Lyuda Samokysh
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Ava Bobinski
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Cale Cowan
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Alvin Jaimon
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Dede Obioru
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Tala Al Makhoul
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Jeffrey A Stuart
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada.
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Xiao Y, Xiang JW, Gao Q, Bai YY, Huang ZX, Hu XH, Wang L, Li DWC. MAB21L1 promotes survival of lens epithelial cells through control of αB-crystallin and ATR/CHK1/p53 pathway. Aging (Albany NY) 2022; 14:6128-6148. [PMID: 35951367 PMCID: PMC9417230 DOI: 10.18632/aging.204203] [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: 03/01/2022] [Accepted: 07/25/2022] [Indexed: 11/25/2022]
Abstract
The male abnormal gene family 21 (mab21), was initially identified in C. elegans. Since its identification, studies from different groups have shown that it regulates development of ocular tissues, brain, heart and liver. However, its functional mechanism remains largely unknown. Here, we demonstrate that Mab21L1 promotes survival of lens epithelial cells. Mechanistically, Mab21L1 upregulates expression of αB-crystallin. Moreover, our results show that αB-crystallin prevents stress-induced phosphorylation of p53 at S-20 and S-37 through abrogating the activation of the upstream kinases, ATR and CHK1. As a result of suppressing p53 activity by αB-crystallin, Mab21L1 downregulates expression of Bak but upregulates Mcl-1 during stress insult. Taken together, our results demonstrate that Mab21L1 promotes survival of lens epithelial cells through upregulation of αB-crystallin to suppress ATR/CHK1/p53 pathway.
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Affiliation(s)
- Yuan Xiao
- College of Life Sciences, Hunan Normal University, Changsha 410080, Hunan, China.,The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Tianhe, Guangzhou 510230, Guangdong, China
| | - Jia-Wen Xiang
- The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Tianhe, Guangzhou 510230, Guangdong, China
| | - Qian Gao
- College of Life Sciences, Hunan Normal University, Changsha 410080, Hunan, China.,The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Tianhe, Guangzhou 510230, Guangdong, China
| | - Yue-Yue Bai
- College of Life Sciences, Hunan Normal University, Changsha 410080, Hunan, China.,The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Tianhe, Guangzhou 510230, Guangdong, China
| | - Zhao-Xia Huang
- Department of Basic Medicine, Guizhou University of Traditional Chinese Medicine, Guiyang 121212, Guizhou, China
| | - Xiao-Hui Hu
- College of Life Sciences, Hunan Normal University, Changsha 410080, Hunan, China
| | - Ling Wang
- The Academician Work Station, Changsha Medical University, Changsha 410219, Hunan, China
| | - David Wan-Cheng Li
- College of Life Sciences, Hunan Normal University, Changsha 410080, Hunan, China.,The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Tianhe, Guangzhou 510230, Guangdong, China
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4
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Ricci A, Biancucci F, Morganti G, Magnani M, Menotta M. New human ATM variants are able to regain ATM functions in ataxia telangiectasia disease. Cell Mol Life Sci 2022; 79:601. [PMID: 36422718 PMCID: PMC9691487 DOI: 10.1007/s00018-022-04625-3] [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: 08/03/2022] [Revised: 10/28/2022] [Accepted: 11/08/2022] [Indexed: 11/25/2022]
Abstract
Ataxia telangiectasia is a rare neurodegenerative disease caused by biallelic mutations in the ataxia telangiectasia mutated gene. No cure is currently available for these patients but positive effects on neurologic features in AT patients have been achieved by dexamethasone administration through autologous erythrocytes (EryDex) in phase II and phase III clinical trials, leading us to explore the molecular mechanisms behind the drug action. During these investigations, new ATM variants, which originated from alternative splicing of ATM messenger, were discovered, and detected in vivo in the blood of AT patients treated with EryDex. Some of the new ATM variants, alongside an in silico designed one, were characterized and examined in AT fibroblast cell lines. ATM variants were capable of rescuing ATM activity in AT cells, particularly in the nuclear role of DNA DSBs recognition and repair, and in the cytoplasmic role of modulating autophagy, antioxidant capacity and mitochondria functionality, all of the features that are compromised in AT but essential for neuron survival. These outcomes are triggered by the kinase and further functional domains of the tested ATM variants, that are useful for restoring cellular functionality. The in silico designed ATM variant eliciting most of the functionality recover may be exploited in gene therapy or gene delivery for the treatment of AT patients.
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Affiliation(s)
- Anastasia Ricci
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Via Saffi 2, 61029, Urbino, Italy.
| | - Federica Biancucci
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Via Saffi 2, 61029, Urbino, Italy
| | - Gianluca Morganti
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Via Saffi 2, 61029, Urbino, Italy
| | - Mauro Magnani
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Via Saffi 2, 61029, Urbino, Italy
| | - Michele Menotta
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Via Saffi 2, 61029, Urbino, Italy
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5
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Yu C, Liu Q, Chen C, Yu J, Wang J. Landscape perspectives of tumor, EMT, and development. Phys Biol 2019; 16:051003. [PMID: 31067516 DOI: 10.1088/1478-3975/ab2029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A tumor is rarely fatal until becoming metastatic. Recent discoveries suggest that epithelial mesenchymal transition(EMT) is an important process which contributes to not only cancer metastasis but also increased stemness. Cancer cells with stem cell characteristics are called cancer stem cells (CSCs). We review recent efforts to quantify and delineate the relationship among EMT, CSC and tumor development. When the gene regulatory network is tightly regulated through the effectively fast regulatory binding, Cancer, Premalignant, Normal, CSC, stem cell (SC), Lesion and Hyperplasia states emerged. The corresponding landscape topography for all of these states can be quantified to a global way for uncovering the relationship among the tumor, metastasis, and development. On the other hand, phenotypic and functional heterogeneity is regarded as one of the greatest challenge in cancer treatment. Cancer and CSCs are heterogeneous and give rise to tumorigenic and non-tumorigenic cells during self-renewal, differentiation and epigenetic diversification. Further, if the gene regulatory network is weakly regulated through the effective slow regulatory binding (by DNA methylation or histone modification etc), multiple meta-stable states can emerge. This model can provide an epigenetic and physical rather than genetic and fixed origin of heterogeneity. Elucidating the origin of and dynamic nature of tumor cells will likely help better understand the cellular basis of therapeutic response, resistance, and relapse.
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Affiliation(s)
- Chong Yu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, People's Republic of China. University of Science and Technology of China, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
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6
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Moussa RS, Park KC, Kovacevic Z, Richardson DR. Ironing out the role of the cyclin-dependent kinase inhibitor, p21 in cancer: Novel iron chelating agents to target p21 expression and activity. Free Radic Biol Med 2019; 133:276-294. [PMID: 29572098 DOI: 10.1016/j.freeradbiomed.2018.03.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 03/02/2018] [Accepted: 03/14/2018] [Indexed: 12/12/2022]
Abstract
Iron (Fe) has become an important target for the development of anti-cancer therapeutics with a number of Fe chelators entering human clinical trials for advanced and resistant cancer. An important aspect of the activity of these compounds is their multiple molecular targets, including those that play roles in arresting the cell cycle, such as the cyclin-dependent kinase inhibitor, p21. At present, the exact mechanism by which Fe chelators regulate p21 expression remains unclear. However, recent studies indicate the ability of chelators to up-regulate p21 at the mRNA level was dependent on the chelator and cell-type investigated. Analysis of the p21 promoter identified that the Sp1-3-binding site played a significant role in the activation of p21 transcription by Fe chelators. Furthermore, there was increased Sp1/ER-α and Sp1/c-Jun complex formation in melanoma cells, suggesting these complexes were involved in p21 promoter activation. Elucidating the mechanisms involved in the regulation of p21 expression in response to Fe chelator treatment in neoplastic cells will further clarify how these agents achieve their anti-tumor activity. It will also enhance our understanding of the complex roles p21 may play in neoplastic cells and lead to the development of more effective and specific anti-cancer therapies.
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Affiliation(s)
- Rayan S Moussa
- Molecular Pharmacology and Pathology Program, Discipline of Pathology and Bosch Institute, Medical Foundation Building (K25), The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Kyung Chan Park
- Molecular Pharmacology and Pathology Program, Discipline of Pathology and Bosch Institute, Medical Foundation Building (K25), The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Zaklina Kovacevic
- Molecular Pharmacology and Pathology Program, Discipline of Pathology and Bosch Institute, Medical Foundation Building (K25), The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Des R Richardson
- Molecular Pharmacology and Pathology Program, Discipline of Pathology and Bosch Institute, Medical Foundation Building (K25), The University of Sydney, Sydney, New South Wales 2006, Australia; Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-ku, Nagoya 466-8550, Japan.
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7
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Kundumani-Sridharan V, Subramani J, Raghavan S, Maiti GP, Owens C, Walker T, Wasnick J, Idell S, Das KC. Short-duration hyperoxia causes genotoxicity in mouse lungs: protection by volatile anesthetic isoflurane. Am J Physiol Lung Cell Mol Physiol 2019; 316:L903-L917. [PMID: 30810065 DOI: 10.1152/ajplung.00142.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
High concentrations of oxygen (hyperoxia) are routinely used during anesthesia, and supplemental oxygen is also administered in connection with several other clinical conditions. Although prolonged hyperoxia is known to cause acute lung injury (ALI), whether short-duration hyperoxia causes lung toxicity remains unknown. We exposed mice to room air (RA or 21% O2) or 60% oxygen alone or in combination with 2% isoflurane for 2 h and determined the expression of oxidative stress marker genes, DNA damage and DNA repair genes, and expression of cell cycle regulatory proteins using quantitative PCR and Western analyses. Furthermore, we determined cellular apoptosis using TUNEL assay and assessed the DNA damage product 8-hydroxy-2'-deoxyguanosine (8-Oxo-dG) in the urine of 60% hyperoxia-exposed mice. Our study demonstrates that short-duration hyperoxia causes mitochondrial and nuclear DNA damage and that isoflurane abrogates this DNA damage and decreases apoptosis when used in conjunction with hyperoxia. In contrast, isoflurane mixed with RA caused significant 8-Oxo-dG accumulations in the mitochondria and nucleus. We further show that whereas NADPH oxidase is a major source of superoxide anion generated by isoflurane in normoxia, isoflurane inhibits superoxide generation in hyperoxia. Additionally, isoflurane also protected the mouse lungs against ALI (95% O2 for 36-h exposure). Our study established that short-duration hyperoxia causes genotoxicity in the lungs, which is abrogated when hyperoxia is used in conjunction with isoflurane, but isoflurane alone causes genotoxicity in the lung when delivered with ambient air.
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Affiliation(s)
| | - Jaganathan Subramani
- Department of Internal Medicine, Texas Tech University Health Sciences Center , Lubbock, Texas
| | - Somasundaram Raghavan
- Department of Internal Medicine, Texas Tech University Health Sciences Center , Lubbock, Texas
| | - Guru P Maiti
- Oklahoma Medical Research Foundation , Oklahoma City, Oklahoma
| | - Cade Owens
- Department of Anesthesiology, Texas Tech University Health Sciences Center , Lubbock, Texas
| | - Trevor Walker
- Department of Anesthesiology, Texas Tech University Health Sciences Center , Lubbock, Texas
| | - John Wasnick
- Department of Anesthesiology, Texas Tech University Health Sciences Center , Lubbock, Texas
| | - Steven Idell
- Department of Cellular and Molecular Biology, Texas Lung Injury Institute, The University of Texas Health Science Center at Tyler , Tyler, Texas
| | - Kumuda C Das
- Department of Internal Medicine, Texas Tech University Health Sciences Center , Lubbock, Texas
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8
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Yu C, Wang J. A Physical Mechanism and Global Quantification of Breast Cancer. PLoS One 2016; 11:e0157422. [PMID: 27410227 PMCID: PMC4943646 DOI: 10.1371/journal.pone.0157422] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 05/31/2016] [Indexed: 12/24/2022] Open
Abstract
Initiation and progression of cancer depend on many factors. Those on the genetic level are often considered crucial. To gain insight into the physical mechanisms of breast cancer, we construct a gene regulatory network (GRN) which reflects both genetic and environmental aspects of breast cancer. The construction of the GRN is based on available experimental data. Three basins of attraction, representing the normal, premalignant and cancer states respectively, were found on the phenotypic landscape. The progression of breast cancer can be seen as switching transitions between different state basins. We quantified the stabilities and kinetic paths of the three state basins to uncover the biological process of breast cancer formation. The gene expression levels at each state were obtained, which can be tested directly in experiments. Furthermore, by performing global sensitivity analysis on the landscape topography, six key genes (HER2, MDM2, TP53, BRCA1, ATM, CDK2) and four regulations (HER2⊣TP53, CDK2⊣BRCA1, ATM→MDM2, TP53→ATM) were identified as being critical for breast cancer. Interestingly, HER2 and MDM2 are the most popular targets for treating breast cancer. BRCA1 and TP53 are the most important oncogene of breast cancer and tumor suppressor gene, respectively. This further validates the feasibility of our model and the reliability of our prediction results. The regulation ATM→MDM2 has been extensive studied on DNA damage but not on breast cancer. We notice the importance of ATM→MDM2 on breast cancer. Previous studies of breast cancer have often focused on individual genes and the anti-cancer drugs are mainly used to target the individual genes. Our results show that the network-based strategy is more effective on treating breast cancer. The landscape approach serves as a new strategy for analyzing breast cancer on both the genetic and epigenetic levels and can help on designing network based medicine for breast cancer.
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Affiliation(s)
- Chong Yu
- State Key Laboratory of Electroanalytical Chemistry/Changchun Institute of Applied Chemistry, Chinese Academy of Sciences/Changchun, Jilin 130022, China
| | - Jin Wang
- State Key Laboratory of Electroanalytical Chemistry/Changchun Institute of Applied Chemistry, Chinese Academy of Sciences/Changchun, Jilin 130022, China
- College of Physics/Jilin University, Changchun, Jilin 130012, China
- Department of Chemistry, Physics & Applied Mathematics/State University of New York at Stony Brook/Stony Brook, NY 11794-3400, United States of America
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9
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Wilhelm T, Ragu S, Magdalou I, Machon C, Dardillac E, Técher H, Guitton J, Debatisse M, Lopez BS. Slow Replication Fork Velocity of Homologous Recombination-Defective Cells Results from Endogenous Oxidative Stress. PLoS Genet 2016; 12:e1006007. [PMID: 27135742 PMCID: PMC4852921 DOI: 10.1371/journal.pgen.1006007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 04/05/2016] [Indexed: 01/01/2023] Open
Abstract
Replications forks are routinely hindered by different endogenous stresses. Because homologous recombination plays a pivotal role in the reactivation of arrested replication forks, defects in homologous recombination reveal the initial endogenous stress(es). Homologous recombination-defective cells consistently exhibit a spontaneously reduced replication speed, leading to mitotic extra centrosomes. Here, we identify oxidative stress as a major endogenous source of replication speed deceleration in homologous recombination-defective cells. The treatment of homologous recombination-defective cells with the antioxidant N-acetyl-cysteine or the maintenance of the cells at low O2 levels (3%) rescues both the replication fork speed, as monitored by single-molecule analysis (molecular combing), and the associated mitotic extra centrosome frequency. Reciprocally, the exposure of wild-type cells to H2O2 reduces the replication fork speed and generates mitotic extra centrosomes. Supplying deoxynucleotide precursors to H2O2-exposed cells rescued the replication speed. Remarkably, treatment with N-acetyl-cysteine strongly expanded the nucleotide pool, accounting for the replication speed rescue. Remarkably, homologous recombination-defective cells exhibit a high level of endogenous reactive oxygen species. Consistently, homologous recombination-defective cells accumulate spontaneous γH2AX or XRCC1 foci that are abolished by treatment with N-acetyl-cysteine or maintenance at 3% O2. Finally, oxidative stress stimulated homologous recombination, which is suppressed by supplying deoxynucleotide precursors. Therefore, the cellular redox status strongly impacts genome duplication and transmission. Oxidative stress should generate replication stress through different mechanisms, including DNA damage and nucleotide pool imbalance. These data highlight the intricacy of endogenous replication and oxidative stresses, which are both evoked during tumorigenesis and senescence initiation, and emphasize the importance of homologous recombination as a barrier against spontaneous genetic instability triggered by the endogenous oxidative/replication stress axis. Endogenous stress is an important stress because it challenges cells daily. However, endogenous stress is difficult to apprehend. Replication forks are routinely hindered by different endogenous stresses. Because homologous recombination plays a pivotal role in the reactivation of arrested replication forks, defects in homologous recombination reveal the initial endogenous stress(es). Here we identify endogenous oxidative stress among the different potential endogenous stresses as being responsible for spontaneous replication defects in homologous recombination-defective cells. Therefore, oxidative and replication stresses, which are both evoked during tumorigenesis and senescence initiation, are linked, and homologous recombination acts as a barrier against spontaneous genetic instability triggered by endogenous oxidative/replication stress.
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Affiliation(s)
- Therese Wilhelm
- CNRS UMR 8200, Gustave Roussy Cancer Institute, Université Paris-Saclay, Team labeled “Ligue 2014”, Villejuif, France
| | - Sandrine Ragu
- CNRS UMR 8200, Gustave Roussy Cancer Institute, Université Paris-Saclay, Team labeled “Ligue 2014”, Villejuif, France
| | - Indiana Magdalou
- CNRS UMR 8200, Gustave Roussy Cancer Institute, Université Paris-Saclay, Team labeled “Ligue 2014”, Villejuif, France
| | - Christelle Machon
- Laboratoire de Biochimie et Toxicologie, Hospices Civils de Lyon, Centre Hospitalier Lyon-Sud, Pierre-Bénite, France
- Laboratoire de Chimie Analytique, Université de Lyon, Université Lyon 1, ISPB Faculté de Pharmacie, Lyon, France
| | - Elodie Dardillac
- CNRS UMR 8200, Gustave Roussy Cancer Institute, Université Paris-Saclay, Team labeled “Ligue 2014”, Villejuif, France
| | - Hervé Técher
- Institut Curie, Centre de Recherche, Paris, France, UPMC Université Paris 06, Paris, France, CNRS UMR 3244, Paris, France
| | - Jérôme Guitton
- Laboratoire de Biochimie et Toxicologie, Hospices Civils de Lyon, Centre Hospitalier Lyon-Sud, Pierre-Bénite, France
- Laboratoire de Toxicologie, Université Lyon 1, ISPB, Faculté de Pharmacie, Lyon, France
| | - Michelle Debatisse
- Institut Curie, Centre de Recherche, Paris, France, UPMC Université Paris 06, Paris, France, CNRS UMR 3244, Paris, France
| | - Bernard S. Lopez
- CNRS UMR 8200, Gustave Roussy Cancer Institute, Université Paris-Saclay, Team labeled “Ligue 2014”, Villejuif, France
- * E-mail:
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10
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Campbell A, Krupp B, Bushman J, Noble M, Pröschel C, Mayer-Pröschel M. A novel mouse model for ataxia-telangiectasia with a N-terminal mutation displays a behavioral defect and a low incidence of lymphoma but no increased oxidative burden. Hum Mol Genet 2015; 24:6331-49. [PMID: 26310626 DOI: 10.1093/hmg/ddv342] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 08/17/2015] [Indexed: 12/13/2022] Open
Abstract
Ataxia-telangiectasia (A-T) is a rare multi-system disorder caused by mutations in the ATM gene. Significant heterogeneity exists in the underlying genetic mutations and clinical phenotypes. A number of mouse models have been generated that harbor mutations in the distal region of the gene, and a recent study suggests the presence of residual ATM protein in the brain of one such model. These mice recapitulate many of the characteristics of A-T seen in humans, with the notable exception of neurodegeneration. In order to study how an N-terminal mutation affects the disease phenotype, we generated an inducible Atm mutant mouse model (Atm(tm1Mmpl/tm1Mmpl), referred to as A-T [M]) predicted to express only the first 62 amino acids of Atm. Cells derived from A-T [M] mutant mice exhibited reduced cellular proliferation and an altered DNA damage response, but surprisingly, showed no evidence of an oxidative imbalance. Examination of the A-T [M] animals revealed an altered immunophenotype consistent with A-T. In contrast to mice harboring C-terminal Atm mutations that disproportionately develop thymic lymphomas, A-T [M] mice developed lymphoma at a similar rate as human A-T patients. Morphological analyses of A-T [M] cerebella revealed no substantial cellular defects, similar to other models of A-T, although mice display behavioral defects consistent with cerebellar dysfunction. Overall, these results suggest that loss of Atm is not necessarily associated with an oxidized phenotype as has been previously proposed and that loss of ATM protein is not sufficient to induce cerebellar degeneration in mice.
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Affiliation(s)
- Andrew Campbell
- Department of Biomedical Genetics, University of Rochester, 601 Elmwood Avenue, Box 633, Rochester, NY 14642, USA, Department of Pathology and Laboratory Medicine, University of Rochester, Rochester, NY 14642, USA and
| | - Brittany Krupp
- Department of Biomedical Genetics, University of Rochester, 601 Elmwood Avenue, Box 633, Rochester, NY 14642, USA
| | - Jared Bushman
- Division of Pharmaceutical Sciences, University of Wyoming School of Pharmacy, 1000 East University Ave., Dept. 3375, Laramie, WY 82071, USA
| | - Mark Noble
- Department of Biomedical Genetics, University of Rochester, 601 Elmwood Avenue, Box 633, Rochester, NY 14642, USA
| | - Christoph Pröschel
- Department of Biomedical Genetics, University of Rochester, 601 Elmwood Avenue, Box 633, Rochester, NY 14642, USA
| | - Margot Mayer-Pröschel
- Department of Biomedical Genetics, University of Rochester, 601 Elmwood Avenue, Box 633, Rochester, NY 14642, USA,
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Abstract
Oxygen is the basic molecule which supports life and it truly is "god's gift to life." Despite its immense importance, research on "oxygen biology" has never received the light of the day and has been limited to physiological and biochemical studies. It seems that in modern day biology, oxygen research is summarized in one word "hypoxia." Scientists have focused on hypoxia-induced transcriptomics and molecular-cellular alterations exclusively in disease models. Interestingly, the potential of oxygen to control the basic principles of biology like homeostatic maintenance, transcription, replication, and protein folding among many others, at the molecular level, has been completely ignored. Here, we present a perspective on the crucial role played by oxygen in regulation of basic biological phenomena. Our conclusion highlights the importance of establishing novel research areas like oxygen biology, as there is great potential in this field for basic science discoveries and clinical benefits to the society.
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Das KC. Thioredoxin-deficient mice, a novel phenotype sensitive to ambient air and hypersensitive to hyperoxia-induced lung injury. Am J Physiol Lung Cell Mol Physiol 2014; 308:L429-42. [PMID: 25539854 DOI: 10.1152/ajplung.00285.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Pulmonary oxygen toxicity is a major clinical problem for patients undergoing supplemental oxygen therapy. Thioredoxin (Trx) is an endogenous antioxidant protein that regenerates oxidatively inactivated proteins. We examined how Trx contributes to oxygen tolerance by creating transgenic mice with decreased levels of functional thioredoxin (dnTrx-Tg) using a dominant-negative approach. These mice showed decreased Trx activity in the lung although the expression of mutant protein is three times higher than the wild-type mice. Additionally, we found that these mice showed increased oxidation of endogenous Trx in room air. When exposed to hyperoxia (>90% O2) for 4 days, they failed to recover and showed significant mortality. Even in normal oxygen levels, these mice displayed a significant decrease in aconitase and NADH dehydrogenase activities, decreased mitochondrial energy metabolism, increased p53 and Gadd45α expression, and increased synthesis of proinflammatory cytokines. These effects were further increased by hyperoxia. We also generated mice overexpressing Trx (Trx-Tg) and found they maintained lung redox balance during exposure to high oxygen and thus were resistant to hyperoxia-induced lung injury. These mice had increased levels of reduced Trx in the lung in normoxia as well as hyperoxia. Furthermore, the levels of aconitase and NADH dehydrogenase activities were maintained in these mice concomitant with maintenance of mitochondrial energy metabolism. The genotoxic stress markers such as p53 or Gadd45α remained in significantly lower levels in hyperoxia compared with dnTrx-Tg or wild-type mice. These studies establish that mice deficient in functional Trx exhibit a phenotype of sensitivity to ambient air and hypersensitivity to hyperoxia.
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Affiliation(s)
- Kumuda C Das
- Department of Anesthesiology and Center for Excellence in Cardiovascular Research, Texas Tech University Health Sciences Center, Lubbock, Texas
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13
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Wu SH, Wu TY, Hsiao YT, Lin JH, Hsu SC, Hsia TC, Yang ST, Hsu WH, Chung JG. Bufalin induces cell death in human lung cancer cells through disruption of DNA damage response pathways. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2014; 42:729-42. [PMID: 24871662 DOI: 10.1142/s0192415x14500475] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Bufalin is a key component of a Chinese medicine (Chan Su) and has been proved effective in killing various cancer cells. Its role in inducing DNA damage and the inhibition of the DNA damage response (DDR) has been reported, but none have studied such action in lung cancer in detail. In this study, we demonstrated bufalin-induced DNA damage and condensation in NCI-H460 cells through a comet assay and DAPI staining, respectively. Western blotting indicated that bufalin suppressed the protein levels associated with DNA damage and repair, such as a DNA dependent serine/threonine protein kinase (DNA-PK), DNA repair proteins breast cancer 1, early onset (BRCA1), 14-3-3 σ (an important checkpoint keeper of DDR), mediator of DNA damage checkpoint 1 (MDC1), O6-methylguanine-DNA methyltransferase (MGMT) and p53 (tumor suppressor protein). Bufalin could activate phosphorylated p53 in NCI-H460 cells. DNA damage in NCI-H460 cells after treatment with bufalin up-regulated its ATM and ATR genes, which encode proteins functioning as sensors in DDR, and also up-regulated the gene expression (mRNA) of BRCA1 and DNA-PK. But bufalin suppressed the gene expression (mRNA) of p53 and 14-3-3 σ, however, bufalin did not significantly affect the mRNA of MGMT. In conclusion, bufalin induced DNA damage in NCI-H460 cells and also inhibited its DNA repair and checkpoint function.
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Affiliation(s)
- Shin-Hwar Wu
- Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan, ROC , Division of Critical Care Medicine, Department of Medicine, Changhua Christian Hospital, Taiwan
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14
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Biphasic response of checkpoint control proteins in hyperoxia: exposure to lower levels of oxygen induces genome maintenance genes in experimental baboon BPD. Mol Cell Biochem 2014; 395:187-98. [PMID: 24939362 DOI: 10.1007/s11010-014-2124-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 06/02/2014] [Indexed: 12/23/2022]
Abstract
Breathing high concentrations of oxygen (hyperoxia) causes lung injury and is associated with lung diseases such as bronchopulmonary dysplasia (BPD), respiratory distress syndrome and persistent pulmonary hypertension of the newborns. Hyperoxia (95-100 %O2) causes DNA damage and growth arrest of lung cells and consequently cells die by apoptosis or necrosis. Although supplemental oxygen therapy is clinically important, the level and duration of hyperoxic exposure that would allow lung cells to reenter the cell cycle remains unclear. We hypothesized that cells exposed to lower concentrations of hyperoxia will retain the capacity to enter cell cycle when recovered in room air. We employed varying concentrations of oxygen (21-95 %) to determine the response of lung cells to hyperoxia. Our results indicate that cells were growth arrested and failed to reenter the cell cycle when exposed to greater than 60 % oxygen. Cell cycle checkpoint proteins were increased in a biphasic manner, increasing until 70 % oxygen, but declined in greater than 90 % oxygen. Microarray analysis shows that there is significant decrease in the abundance of Cdks 6-8 and retinoblastoma protein (Rb), p107 and p130 in exposure to 90 % oxygen for 48 h. We further tested the effect of clinically relevant as needed oxygen [(pro-re-nata (prn)] in premature infant (125-days and 140-days) baboon model of BPD. The microarray results show that 6 or 14d PRN oxygen-exposed animals had induced expression of chromosomal maintenance genes (MCMs), genes related to anti-inflammation, proliferation, and differentiation.
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Marinho HS, Real C, Cyrne L, Soares H, Antunes F. Hydrogen peroxide sensing, signaling and regulation of transcription factors. Redox Biol 2014; 2:535-62. [PMID: 24634836 PMCID: PMC3953959 DOI: 10.1016/j.redox.2014.02.006] [Citation(s) in RCA: 571] [Impact Index Per Article: 57.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 02/19/2014] [Accepted: 02/21/2014] [Indexed: 12/12/2022] Open
Abstract
The regulatory mechanisms by which hydrogen peroxide (H2O2) modulates the activity of transcription factors in bacteria (OxyR and PerR), lower eukaryotes (Yap1, Maf1, Hsf1 and Msn2/4) and mammalian cells (AP-1, NRF2, CREB, HSF1, HIF-1, TP53, NF-κB, NOTCH, SP1 and SCREB-1) are reviewed. The complexity of regulatory networks increases throughout the phylogenetic tree, reaching a high level of complexity in mammalians. Multiple H2O2 sensors and pathways are triggered converging in the regulation of transcription factors at several levels: (1) synthesis of the transcription factor by upregulating transcription or increasing both mRNA stability and translation; (ii) stability of the transcription factor by decreasing its association with the ubiquitin E3 ligase complex or by inhibiting this complex; (iii) cytoplasm–nuclear traffic by exposing/masking nuclear localization signals, or by releasing the transcription factor from partners or from membrane anchors; and (iv) DNA binding and nuclear transactivation by modulating transcription factor affinity towards DNA, co-activators or repressors, and by targeting specific regions of chromatin to activate individual genes. We also discuss how H2O2 biological specificity results from diverse thiol protein sensors, with different reactivity of their sulfhydryl groups towards H2O2, being activated by different concentrations and times of exposure to H2O2. The specific regulation of local H2O2 concentrations is also crucial and results from H2O2 localized production and removal controlled by signals. Finally, we formulate equations to extract from typical experiments quantitative data concerning H2O2 reactivity with sensor molecules. Rate constants of 140 M−1 s−1 and ≥1.3 × 103 M−1 s−1 were estimated, respectively, for the reaction of H2O2 with KEAP1 and with an unknown target that mediates NRF2 protein synthesis. In conclusion, the multitude of H2O2 targets and mechanisms provides an opportunity for highly specific effects on gene regulation that depend on the cell type and on signals received from the cellular microenvironment. Complexity of redox regulation increases along the phylogenetic tree. Complex regulatory networks allow for a high degree of H2O2 biological plasticity. H2O2 modulates gene expression at all steps from transcription to protein synthesis. Fast response (s) is mediated by sensors with high H2O2 reactivity. Low reactivity H2O2 sensors may mediate slow (h) or localized H2O2 responses.
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Affiliation(s)
- H. Susana Marinho
- Departamento de Química e Bioquímica, Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Carla Real
- Departamento de Química e Bioquímica, Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Luísa Cyrne
- Departamento de Química e Bioquímica, Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Helena Soares
- Departamento de Química e Bioquímica, Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Escola Superior de Tecnologia da Saúde de Lisboa, IPL, Lisboa, Portugal
| | - Fernando Antunes
- Departamento de Química e Bioquímica, Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
- Corresponding author.
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Kubota S, Fukumoto Y, Ishibashi K, Soeda S, Kubota S, Yuki R, Nakayama Y, Aoyama K, Yamaguchi N, Yamaguchi N. Activation of the prereplication complex is blocked by mimosine through reactive oxygen species-activated ataxia telangiectasia mutated (ATM) protein without DNA damage. J Biol Chem 2014; 289:5730-46. [PMID: 24421316 DOI: 10.1074/jbc.m113.546655] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mimosine is an effective cell synchronization reagent used for arresting cells in late G1 phase. However, the mechanism underlying mimosine-induced G1 cell cycle arrest remains unclear. Using highly synchronous cell populations, we show here that mimosine blocks S phase entry through ATM activation. HeLa S3 cells are exposed to thymidine for 15 h, released for 9 h by washing out the thymidine, and subsequently treated with 1 mM mimosine for a further 15 h (thymidine → mimosine). In contrast to thymidine-induced S phase arrest, mimosine treatment synchronizes >90% of cells at the G1-S phase boundary by inhibiting the transition of the prereplication complex to the preinitiation complex. Mimosine treatment activates ataxia telangiectasia mutated (ATM)/ataxia telangiectasia and Rad3-related (ATR)-mediated checkpoint signaling without inducing DNA damage. Inhibition of ATM activity is found to induce mimosine-arrested cells to enter S phase. In addition, ATM activation by mimosine treatment is mediated by reactive oxygen species (ROS). These results suggest that, upon mimosine treatment, ATM blocks S phase entry in response to ROS, which prevents replication fork stalling-induced DNA damage.
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Affiliation(s)
- Shoichi Kubota
- From the Department of Molecular Cell Biology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
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17
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Zhang Y, Hunter T. Roles of Chk1 in cell biology and cancer therapy. Int J Cancer 2013; 134:1013-23. [PMID: 23613359 DOI: 10.1002/ijc.28226] [Citation(s) in RCA: 302] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 04/11/2013] [Indexed: 01/05/2023]
Abstract
The evolutionally conserved DNA damage response (DDR) and cell cycle checkpoints preserve genome integrity. Central to these genome surveillance pathways is a protein kinase, Chk1. DNA damage induces activation of Chk1, which then transduces the checkpoint signal and facilitates cell cycle arrest and DNA damage repair. Significant progress has been made recently toward our understanding of Chk1 regulation and its implications in cancer etiology and therapy. Specifically, a model that involves both spatiotemporal and conformational changes of proteins has been proposed for Chk1 activation. Further, emerging evidence suggests that Chk1 does not appear to be a tumor suppressor; instead, it promotes tumor growth and may contribute to anticancer therapy resistance. Recent data from our laboratory suggest that activating, but not inhibiting, Chk1 in the absence of chemotherapy might represent an innovative approach to suppress tumor growth. These findings suggest unique regulation of Chk1 in cell biology and cancer etiology, pointing to novel strategies for targeting Chk1 in cancer therapy.
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Affiliation(s)
- Youwei Zhang
- Department of Pharmacology, Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, OH
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18
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Subamolide a induces mitotic catastrophe accompanied by apoptosis in human lung cancer cells. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:828143. [PMID: 23533526 PMCID: PMC3595678 DOI: 10.1155/2013/828143] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 12/28/2012] [Accepted: 01/23/2013] [Indexed: 12/21/2022]
Abstract
This study investigated the anticancer effects of subamolide A (Sub-A), isolated from Cinnamomum subavenium, on human nonsmall cell lung cancer cell lines A549 and NCI-H460. Treatment of cancer cells with Sub-A resulted in decreased cell viability of both lung cancer cell lines. Sub-A induced lung cancer cell death by triggering mitotic catastrophe with apoptosis. It triggered oxidant stress, indicated by increased cellular reactive oxygen species (ROS) production and decreased glutathione level. The elevated ROS triggered the activation of ataxia-telangiectasia mutation (ATM), which further enhanced the ATF3 upregulation and subsequently enhanced p53 function by phosphorylation at Serine 15 and Serine 392. The antioxidant, EUK8, significantly decreased mitotic catastrophe by inhibiting ATM activation, ATF3 expression, and p53 phosphorylation. The reduction of ATM and ATF3 expression by shRNA decreased Sub-A-mediated p53 phosphorylation and mitotic catastrophe. Sub-A also caused a dramatic 70% reduction in tumor size in an animal model. Taken together, cell death of lung cancer cells in response to Sub-A is dependent on ROS generation, which triggers mitotic catastrophe followed by apoptosis. Therefore, Sub-A may be a novel anticancer agent for the treatment of nonsmall cell lung cancer.
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19
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Gewandter JS, Bambara RA, O'Reilly MA. The RNA surveillance protein SMG1 activates p53 in response to DNA double-strand breaks but not exogenously oxidized mRNA. Cell Cycle 2011; 10:2561-7. [PMID: 21701263 DOI: 10.4161/cc.10.15.16347] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
DNA damage, stalled replication forks, errors in mRNA splicing, and availability of nutrients activate specific phosphatidylinositiol-3 kinase-like kinases (PIKKs) that in turn phosphorylate downstream targets such as p53 on serine 15. While the PIKK proteins ATM and ATR respond to specific DNA lesions, SMG1 responds to errors in mRNA splicing and when cells are exposed to genotoxic stress. Yet, whether genotoxic stress activates SMG1 through specific types of DNA lesions or RNA damage remains poorly understood. Here, we demonstrate that siRNA oligonucleotides targeting the mRNA surveillance proteins SMG1, Upf1, Upf2, or the PIKK protein ATM attenuated p53 (ser15) phosphorylation in cells damaged by high oxygen (hyperoxia), a model of persistent oxidative stress that damages nucleotides. In contrast, loss of SMG1 or ATM, but not Upf1 or Upf2 reduced p53 (ser15) phosphorylation in response to DNA double strand breaks produced by expression of the endonuclease I-PpoI. To determine whether SMG1-dependent activation of p53 was in response to oxidative mRNA damage, mRNA encoding green fluorescence protein (GFP) transcribed in vitro was oxidized by Fenton chemistry and transfected into cells. Although oxidation of GFP mRNA resulted in dose-dependent fragmentation of the mRNA and reduced expression of GFP, it did not stimulate p53 or the p53-target gene p21. These findings establish SMG1 activates p53 in response to DNA double-strand breaks independent of the RNA surveillance proteins Upf1 or Upf2; however, these proteins can stimulate p53 in response to oxidative stress but not necessarily oxidized RNA.
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Affiliation(s)
- Jennifer S Gewandter
- Department of Biochemistry and Biophysics, The University of Rochester, Rochester, NY, USA
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20
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Abstract
Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53−/− mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53−/− mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo.
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21
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Zou S, Chang J, LaFever L, Tang W, Johnson EL, Hu J, Wilk R, Krause HM, Drummond-Barbosa D, Irusta PM. Identification of dAven, a Drosophila melanogaster ortholog of the cell cycle regulator Aven. Cell Cycle 2011; 10:989-98. [PMID: 21368576 DOI: 10.4161/cc.10.6.15080] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Aven is a regulator of the DNA-damage response and G2/M cell cycle progression. Overexpression of Aven is associated with poor prognosis in patients with childhood acute lymphoblastic leukemia and acute myeloid leukemia, and altered intracellular Aven distribution is associated with infiltrating ductal carcinoma and papillary carcinoma breast cancer subtypes. Although Aven orthologs have been identified in most vertebrate species, no Aven gene has been reported in invertebrates. Here, we describe a Drosophila melanogaster open reading frame (ORF) that shares sequence and functional similarities with vertebrate Aven genes. The protein encoded by this ORF, which we named dAven, contains several domains that are highly conserved among Aven proteins of fish, amphibian, bird and mammalian origins. In flies, knockdown of dAven by RNA interference (RNAi) resulted in lethality when its expression was reduced either ubiquitously or in fat cells using Gal4 drivers. Animals undergoing moderate dAven knockdown in the fat body had smaller fat cells displaying condensed chromosomes and increased levels of the mitotic marker phosphorylated histone H3 (PHH3), suggesting that dAven was required for normal cell cycle progression in this tissue. Remarkably, expression of dAven in Xenopus egg extracts resulted in G2/M arrest that was comparable to that caused by human Aven. Taken together, these results suggest that, like its vertebrate counterparts, dAven plays a role in cell cycle regulation. Drosophila could be an excellent model for studying the function of Aven and identifying cellular factors that influence its activity, revealing information that may be relevant to human disease.
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Affiliation(s)
- Sige Zou
- Laboratory of Experimental Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
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22
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Ravi D, Chen Y, Karia B, Brown A, Gu TT, Li J, Carey MS, Hennessy BT, Bishop AJR. 14-3-3 σ expression effects G2/M response to oxygen and correlates with ovarian cancer metastasis. PLoS One 2011; 6:e15864. [PMID: 21249227 PMCID: PMC3018427 DOI: 10.1371/journal.pone.0015864] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Accepted: 11/25/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND In vitro cell culture experiments with primary cells have reported that cell proliferation is retarded in the presence of ambient compared to physiological O₂ levels. Cancer is primarily a disease of aberrant cell proliferation, therefore, studying cancer cells grown under ambient O₂ may be undesirable. To understand better the impact of O₂ on the propagation of cancer cells in vitro, we compared the growth potential of a panel of ovarian cancer cell lines under ambient (21%) or physiological (3%) O₂. PRINCIPAL FINDINGS Our observations demonstrate that similar to primary cells, many cancer cells maintain an inherent sensitivity to O₂, but some display insensitivity to changes in O₂ concentration. Further analysis revealed an association between defective G2/M cell cycle transition regulation and O₂ insensitivity resultant from overexpression of 14-3-3 σ. Targeting 14-3-3 σ overexpression with RNAi restored O₂ sensitivity in these cell lines. Additionally, we found that metastatic ovarian tumors frequently overexpress 14-3-3 σ, which in conjunction with phosphorylated RB, results in poor prognosis. CONCLUSIONS Cancer cells show differential proliferative sensitivity to changes in O₂ concentration. Although a direct link between O₂ insensitivity and metastasis was not determined, this investigation showed that an O₂ insensitive phenotype in cancer cells to correlate with metastatic tumor progression.
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Affiliation(s)
- Dashnamoorthy Ravi
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center, San Antonio, Texas, United States of America
- Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - Yidong Chen
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center, San Antonio, Texas, United States of America
- Department of Epidemiology and Biostatistics, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - Bijal Karia
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center, San Antonio, Texas, United States of America
- Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - Adam Brown
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center, San Antonio, Texas, United States of America
- Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - Ting Ting Gu
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - Jie Li
- Department of Gynecologic Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Mark S. Carey
- Department of Gynecologic Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of British Columbia, Vancouver, Canada
| | - Bryan T. Hennessy
- Department of Gynecologic Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
- Department of Medical Oncology, Beaumont Hospital, Dublin, Ireland
| | - Alexander J. R. Bishop
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center, San Antonio, Texas, United States of America
- Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, Texas, United States of America
- * E-mail:
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Abstract
Various heat shock proteins, including Hsp72, are strongly upregulated in cancers, but their significance for tumor emergence and growth is poorly understood. Here we review recent data from several labs to indicate that Hsps, including Hsp72, are critical for growth of transformed but not normal cells. By manipulating expression and activity of Hsp72 and several oncogenes, it was shown that Hsp72 suppresses oncogene-induced senescence, thus allowing proliferation of cancer cells. Importantly, Hsp72 is able to suppress both p53-dependent and p53-independent senescence pathways. We propose that targeting Hsp72 may be a promising approach toward development of novel cancer therapies.
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Affiliation(s)
- Michael Sherman
- Department of Biochemistry, Boston University Medical School, Boston, Massachusetts, USA.
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24
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Muniyappa H, Song S, Mathews CK, Das KC. Reactive oxygen species-independent oxidation of thioredoxin in hypoxia: inactivation of ribonucleotide reductase and redox-mediated checkpoint control. J Biol Chem 2009; 284:17069-17081. [PMID: 19369702 DOI: 10.1074/jbc.m109.008557] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
We have investigated the role of cellular redox state on the regulation of cell cycle in hypoxia and shown that whereas cells expressing mutant thioredoxin (Trx) or a normal level of Trx undergo increased apoptosis, cells overexpressing Trx are protected against apoptosis. We show that hypoxia activates p53 and Chk1/Chk2 proteins in cells expressing normal or mutant Trx but not in cells overexpressing Trx. We also show that the activity of ribonucleotide reductase decreases in hypoxia in cells expressing redox-inactive Trx. Although hypoxia has been shown to induce reactive oxygen species (ROS) generation in the mitochondria resulting in enhanced p53 expression, our data demonstrate that hypoxia-induced p53 expression and phosphorylation are independent of ROS. Furthermore, hypoxia induces oxidation of Trx, and this oxidation is potentiated in the presence of 6-aminonicotinamide, an inhibitor of glucose-6-phosphate dehydrogenase. Taken together our study shows that Trx redox state is modulated in hypoxia independent of ROS and is a critical determinant of cell cycle regulation.
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Affiliation(s)
- Harish Muniyappa
- From the Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Shiwei Song
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331
| | - Christopher K Mathews
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331
| | - Kumuda C Das
- From the Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205.
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25
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Abstract
The state of wound oxygenation is a key determinant of healing outcomes. From a diagnostic standpoint, measurements of wound oxygenation are commonly used to guide treatment planning such as amputation decision. In preventive applications, optimizing wound perfusion and providing supplemental O(2) in the perioperative period reduces the incidence of postoperative infections. Correction of wound pO(2) may, by itself, trigger some healing responses. Importantly, approaches to correct wound pO(2) favorably influence outcomes of other therapies such as responsiveness to growth factors and acceptance of grafts. Chronic ischemic wounds are essentially hypoxic. Primarily based on the tumor literature, hypoxia is generally viewed as being angiogenic. This is true with the condition that hypoxia be acute and mild to modest in magnitude. Extreme near-anoxic hypoxia, as commonly noted in problem wounds, is not compatible with tissue repair. Adequate wound tissue oxygenation is required but may not be sufficient to favorably influence healing outcomes. Success in wound care may be improved by a personalized health care approach. The key lies in our ability to specifically identify the key limitations of a given wound and in developing a multifaceted strategy to specifically address those limitations. In considering approaches to oxygenate the wound tissue it is important to recognize that both too little as well as too much may impede the healing process. Oxygen dosing based on the specific need of a wound therefore seems prudent. Therapeutic approaches targeting the oxygen sensing and redox signaling pathways are promising.
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Affiliation(s)
- Chandan K Sen
- The Comprehensive Wound Center, Department of Surgery and Davis Heart and Lung Research Institute, The Ohio State University Medical Center, Columbus, Ohio, USA.
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26
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Kulkarni A, Das KC. Differential roles of ATR and ATM in p53, Chk1, and histone H2AX phosphorylation in response to hyperoxia: ATR-dependent ATM activation. Am J Physiol Lung Cell Mol Physiol 2008; 294:L998-L1006. [PMID: 18344416 DOI: 10.1152/ajplung.00004.2008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Elevated level of oxygen (hyperoxia) is widely used in critical care units and in respiratory insufficiencies. In addition, hyperoxia has been implicated in many diseases such as bronchopulmonary dysplasia or acute respiratory distress syndrome. Although hyperoxia is known to cause DNA base modifications and strand breaks, the DNA damage response has not been adequately investigated. We have investigated the effect of hyperoxia on DNA damage signaling and show that hyperoxia is a unique stress that activates the ataxia telangiectasia mutant (ATM)- and Rad3-related protein kinase (ATR)-dependent p53 phosphorylations (Ser6, -15, -37, and -392), phosphorylation of histone H2AX (Ser139), and phosphorylation of checkpoint kinase 1 (Chk1). In addition, we show that phosphorylation of p53 (Ser6) and histone H2AX (Ser139) depend on both ATM and ATR. We demonstrate that ATR activation precedes ATM activation in hyperoxia. Finally, we show that ATR is required for ATM activation in hyperoxia. Taken together, we report that ATR is the major DNA damage signal transducer in hyperoxia that activates ATM.
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Affiliation(s)
- Amit Kulkarni
- Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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27
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Gehen SC, Staversky RJ, Bambara RA, Keng PC, O'Reilly MA. hSMG-1 and ATM sequentially and independently regulate the G1 checkpoint during oxidative stress. Oncogene 2008; 27:4065-74. [PMID: 18332866 DOI: 10.1038/onc.2008.48] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Genotoxic stress activates the phosphatidylinositol 3-kinase-like kinases (PIKKs) that phosphorylate proteins involved in cell cycle arrest, DNA repair and apoptosis. Previous work showed that the PIKK ataxia telangiectasia mutated (ATM) but not ATM and Rad3 related phosphorylates p53 (Ser15) during hyperoxia, a model of prolonged oxidative stress and DNA damage. Here, we show hSMG-1 is responsible for the rapid and early phosphorylation of p53 (Ser15) and that ATM helps maintain phosphorylation after 24 h. Despite reduced p53 phosphorylation and abundance in cells depleted of hSMG-1 or ATM, levels of the p53 target p21 were still elevated and the G(1) checkpoint remained intact. Conditional overexpression of p21 in p53-deficient cells revealed that hyperoxia also stimulates wortmannin-sensitive degradation of p21. siRNA depletion of hSMG-1 or ATM restored p21 stability and the G(1) checkpoint during hyperoxia. These findings establish hSMG-1 as a proximal regulator of DNA damage signaling and reveal that the G(1) checkpoint is tightly regulated during prolonged oxidative stress by both PIKK-dependent synthesis and proteolysis of p21.
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Affiliation(s)
- S C Gehen
- Department of Environmental Medicine, The University of Rochester, Rochester, NY 14642, USA
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28
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Caffeine inhibits UV-mediated NF-κB activation in A2058 melanoma cells: an ATM-PKCδ-p38 MAPK-dependent mechanism. Mol Cell Biochem 2007; 308:193-200. [DOI: 10.1007/s11010-007-9628-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Accepted: 10/03/2007] [Indexed: 10/22/2022]
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29
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Pistollato F, Chen HL, Schwartz PH, Basso G, Panchision DM. Oxygen tension controls the expansion of human CNS precursors and the generation of astrocytes and oligodendrocytes. Mol Cell Neurosci 2007; 35:424-35. [PMID: 17498968 DOI: 10.1016/j.mcn.2007.04.003] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2006] [Revised: 03/30/2007] [Accepted: 04/06/2007] [Indexed: 01/16/2023] Open
Abstract
Human neural precursor proliferation and potency is limited by senescence and loss of oligodendrocyte potential. We found that in vitro expansion of human postnatal brain CD133(+) nestin(+) precursors is enhanced at 5% oxygen, while raising oxygen tension to 20% depletes precursors and promotes astrocyte differentiation even in the presence of mitogens. Higher cell densities yielded more astrocytes regardless of oxygen tension. This was reversed by noggin at 5%, but not 20%, oxygen due to a novel repressive effect of low oxygen on bone morphogenetic protein (BMP) signaling. When induced to differentiate by mitogen withdrawal, 5% oxygen-expanded precursors generated 17-fold more oligodendrocytes than cells expanded in 20% oxygen. When precursors were expanded at 5% oxygen and then differentiated at 20% oxygen, oligodendrocyte maturation was further enhanced 2.5-fold. These results indicate that dynamic control of oxygen tension regulates different steps in fate and maturation and may be crucial for treating neurodegenerative diseases.
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Affiliation(s)
- Francesca Pistollato
- Center for Neuroscience Research, Children's Research Institute, Children's National Medical Center, 5th Floor, Suite 5340, 111 Michigan Avenue, N.W., Washington, DC 20010, USA
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30
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Chen HL, Pistollato F, Hoeppner DJ, Ni HT, McKay RDG, Panchision DM. Oxygen tension regulates survival and fate of mouse central nervous system precursors at multiple levels. Stem Cells 2007; 25:2291-301. [PMID: 17556599 DOI: 10.1634/stemcells.2006-0609] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Despite evidence that oxygen regulates neural precursor fate, the effects of changing oxygen tensions on distinct stages in precursor differentiation are poorly understood. We found that 5% oxygen permitted clonal and long-term expansion of mouse fetal cortical precursors. In contrast, 20% oxygen caused a rapid decrease in hypoxia-inducible factor 1alpha and nucleophosmin, followed by the induction of p53 and apoptosis of cells. This led to a decrease in overall cell number and particularly a loss of astrocytes and oligodendrocytes. Clonal analysis revealed that apoptosis in 20% oxygen was due to a complete loss of CD133(lo)CD24(lo) multipotent precursors, a substantial loss of CD133(hi)CD24(lo) multipotent precursors, and a failure of remaining CD133(hi)CD24(lo) cells to generate glia. In contrast, committed neuronal progenitors were not significantly affected. Switching clones from 5% to 20% oxygen only after mitogen withdrawal led to a decrease in total clone numbers but an even greater decrease in oligodendrocyte-containing clones. During this late exposure to 20% oxygen, bipotent glial (A2B5+) and early (platelet-derived growth factor receptor alpha) oligodendrocyte progenitors appeared and disappeared more quickly, relative to 5% oxygen, and late stage O4+ oligodendrocyte progenitors never appeared. These results indicate that multipotent cells and oligodendrocyte progenitors are more susceptible to apoptosis at 20% oxygen than committed neuronal progenitors. This has important implications for optimizing ex vivo production methods for cell replacement therapies.
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Affiliation(s)
- Hui-Ling Chen
- Center for Neuroscience Research, Children's National Medical Center, Washington, DC, USA
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31
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Sherman MY, Sherman M, Gabai V, O'Callaghan C, Yaglom J. Molecular chaperones regulate p53 and suppress senescence programs. FEBS Lett 2007; 581:3711-5. [PMID: 17555746 PMCID: PMC3433766 DOI: 10.1016/j.febslet.2007.05.036] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Accepted: 05/14/2007] [Indexed: 01/21/2023]
Abstract
Many types of cancer cells constitutively express major molecular chaperones at high levels. Recent findings demonstrate that specific depletion of individual chaperones, including various members of the Hsp70 family, small heat shock proteins, or VCP/p97, leads to activation of p53 pathway and subsequently triggers cellular senescence. Here, we discuss a possibility that in cancer cells high levels of chaperones serve to keep the p53 signaling under control, thus allowing cancer cells to evade the default senescence and form tumors.
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Affiliation(s)
- Michael Y Sherman
- Department of Biochemistry, Boston University Medical School, 715 Albany Street, K323, Boston, MA 02118, United States.
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32
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LaRocque JR, Dougherty DL, Hussain SK, Sekelsky J. Reducing DNA polymerase alpha in the absence of Drosophila ATR leads to P53-dependent apoptosis and developmental defects. Genetics 2007; 176:1441-51. [PMID: 17483406 PMCID: PMC1931523 DOI: 10.1534/genetics.107.073635] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The ability to respond to DNA damage and incomplete replication ensures proper duplication and stability of the genome. Two checkpoint kinases, ATM and ATR, are required for DNA damage and replication checkpoint responses. In Drosophila, the ATR ortholog (MEI-41) is essential for preventing entry into mitosis in the presence of DNA damage. In the absence of MEI-41, heterozygosity for the E(mus304) mutation causes rough eyes. We found that E(mus304) is a mutation in DNApol-alpha180, which encodes the catalytic subunit of DNA polymerase alpha. We did not find any defects resulting from reducing Polalpha by itself. However, reducing Polalpha in the absence of MEI-41 resulted in elevated P53-dependent apoptosis, rough eyes, and increased genomic instability. Reducing Polalpha in mutants that lack downstream components of the DNA damage checkpoint (DmChk1 and DmChk2) results in the same defects. Furthermore, reducing levels of mitotic cyclins rescues both phenotypes. We suggest that reducing Polalpha slows replication, imposing an essential requirement for the MEI-41-dependent checkpoint for maintenance of genome stability, cell survival, and proper development. This work demonstrates a critical contribution of the checkpoint function of MEI-41 in responding to endogenous damage.
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Affiliation(s)
- Jeannine R LaRocque
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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33
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O'Brien EA, Barnes V, Zhao L, McKnight RA, Yu X, Callaway CW, Wang L, Sun JC, Dahl MJ, Wint A, Wang Z, McIntyre TM, Albertine KH, Lane RH. Uteroplacental insufficiency decreases p53 serine-15 phosphorylation in term IUGR rat lungs. Am J Physiol Regul Integr Comp Physiol 2007; 293:R314-22. [PMID: 17428897 DOI: 10.1152/ajpregu.00265.2005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intrauterine growth restriction (IUGR) increases the incidence of chronic lung disease (CLD). The molecular mechanisms responsible for IUGR-induced acute lung injury that predispose the IUGR infant to CLD are unknown. p53, a transcription factor, plays a pivotal role in determining cellular response to stress by affecting apoptosis, cell cycle regulation, and angiogenesis, processes required for thinning of lung mesenchyme. Because thickened lung mesenchyme is characteristic of CLD, we hypothesized that IUGR-induced changes in lung growth are associated with alterations in p53 expression and/or modification. We induced IUGR through bilateral uterine artery ligation of pregnant rats. Uteroplacental insufficiency significantly decreased serine-15-phosphorylated (serine-15P) p53, an active form of p53, in IUGR rat lung. Moreover, we found that decreased phosphorylation of lung p53 serine-15 localized to thickened distal air space mesenchyme. We also found that IUGR significantly decreased mRNA for targets downstream of p53, specifically, proapoptotic Bax and Apaf, as well as Gadd45, involved in growth arrest, and Tsp-1, involved in angiogenesis. Furthermore, we found that IUGR significantly increased mRNA for Bcl-2, an antiapoptotic gene downregulated by p53. We conclude that in IUGR rats, uteroplacental insufficiency induces decreased lung mesenchymal p53 serine-15P in association with distal lung mesenchymal thickening. We speculate that decreased p53 serine-15P in IUGR rat lungs alters lung phenotype, making the IUGR lung more susceptible to subsequent injury.
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Affiliation(s)
- E A O'Brien
- Division of Neonatology, University of Utah, Salt Lake City, UT 84158, USA.
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Cannizzaro A, Verga Falzacappa CV, Martinelli M, Misiti S, Brunetti E, Bucci B. O2/3 exposure inhibits cell progression affecting cyclin B1/cdk1 activity in SK-N-SH while induces apoptosis in SK-N-DZ neuroblastoma cells. J Cell Physiol 2007; 213:115-25. [PMID: 17477375 DOI: 10.1002/jcp.21097] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In search for innovative therapeutic agents for children neuroblastoma, the oxygen therapy could be considered an alternative anti-tumoral treatment. Given the physiochemical properties of O(2/3) gas mixture including fairly low aqueous solubility and spreading, and the interesting perspective of hyperoxia, we analyzed the inhibitory effect of O(2/3) treatment on two human neuroblastoma cell lines (SK-N-SH and SK-N-DZ). In this study, we demonstrated that O(2/3) treatment was able to induce cell growth inhibition and cell cycle perturbation in both cell lines. We observed an arrest at G(2) phase, accompanied by an alteration in the expression and localization of cyclin B1/cdk1 complex and a reduction in its activity in SK-N-SH cells. This reduction was consistent with the increase in both Wee1 and chk1 protein levels. On the contrary, O(2/3) induced apoptosis in SK-N-DZ cells via caspase 3 activation and Poly ADP-ribose polymerase-1 (PARP) cleavage, associated with an increase in the pro-apoptotic Bax protein. Consequently, we considered the possibility of improving the responsiveness to chemotherapeutic agents such as Cisplatin, Etoposide, and Gemcitabine in combination with O(2/3) treatment. The combined treatments produced a stronger cell inhibitory effect than Cisplatin and Etoposide used alone in SK-N-SH cells. On the contrary, the combination data were not significantly different from O(2/3) treatment alone in SK-N-DZ cells, thus suggesting that the obtained changes in cell growth inhibition were due to the effect of O(2/3) alone.
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Affiliation(s)
- A Cannizzaro
- AFAR-Centro Ricerca S. Pietro, Fatebenefratelli Hospital, Roma, Italy
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35
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Abstract
The ability of a cell to sense and respond to DNA damage is essential for genome stability. An important aspect of the response is arrest of the cell cycle, presumably to allow time for repair. Ataxia telangiectasia mutated (ATM) and ATR are essential for such cell-cycle control, but some observations suggest that they also play a direct role in DNA repair. The Drosophila ortholog of ATR, MEI-41, mediates the DNA damage-dependent G2-M checkpoint. We examined the role of MEI-41 in repair of double-strand breaks (DSBs) induced by P-element excision. We found that mei-41 mutants are defective in completing the later steps of homologous recombination repair, but have no defects in end-joining repair. We hypothesized that these repair defects are the result of loss of checkpoint control. To test this, we genetically reduced mitotic cyclin levels and also examined repair in grp (DmChk1) and lok (DmChk2) mutants. Our results suggest that a significant component of the repair defects is due to loss of MEI-41-dependent cell cycle regulation. However, this does not account for all of the defects we observed. We propose a novel role for MEI-41 in DSB repair, independent of the Chk1/Chk2-mediated checkpoint response.
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Affiliation(s)
- Jeannine R LaRocque
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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36
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Hsu JC, Dev A, Wing A, Brew CT, Bjeldanes LF, Firestone GL. Indole-3-carbinol mediated cell cycle arrest of LNCaP human prostate cancer cells requires the induced production of activated p53 tumor suppressor protein. Biochem Pharmacol 2006; 72:1714-23. [PMID: 16970927 DOI: 10.1016/j.bcp.2006.08.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Revised: 08/14/2006] [Accepted: 08/15/2006] [Indexed: 10/24/2022]
Abstract
Indole-3-carbinol (I3C), a dietary compound found naturally in cruciferous vegetables of the Brassica genus such as broccoli and brussels sprouts, induces a G1 growth arrest of human reproductive cancer cells. We previously reported that in LNCaP prostate cancer cells, I3C down-regulated cyclin-dependent kinase (CDK) 2 activity. In our current study, Western blotting and quantitative RT-PCR demonstrated that I3C treatment increased both the transcripts and protein levels of the CDK2 inhibitor p21(waf1/cip1) (p21). Transfection of luciferase reporter plasmids containing wild-type and mutated p21 promoter fragments revealed that I3C induced p21 gene transcription through a p53 DNA binding element. Oligonucleotide precipitation showed that I3C increased the level of activated p53 nuclear protein that is competent to bind its DNA target site on the p21 promoter. Ablation of p53 production using short interfering RNA (siRNA) prevented that the I3C induced G1 arrest and up-regulation of p21 expression. Western blots using p53 phospho-specific antibodies revealed that I3C treatment increased the levels of three phosphorylated forms of p53 (Ser15, Ser37, Ser392) that are known to contribute to p53 protein stability and greater transactivation potential. Taken together, our results establish that the I3C induced G1 arrest of human prostate cancer cells requires the induced production of the activated phosphorylated forms of p53, which stimulate transcription of the CDK2 inhibitor p21.
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Affiliation(s)
- Jocelyn C Hsu
- Department of Molecular and Cell Biology and The Cancer Research Laboratory, The University of California at Berkeley, Berkeley, CA 94720, USA
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37
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Hiramatsu K, Ogino T, Ozaki M, Okada S. Monochloramine inhibits ultraviolet B-induced p53 activation and DNA repair response in human fibroblasts. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:188-96. [PMID: 16414131 DOI: 10.1016/j.bbamcr.2005.11.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2005] [Revised: 11/15/2005] [Accepted: 11/18/2005] [Indexed: 11/20/2022]
Abstract
Monochloramine (NH2Cl) is one of the inflammation-derived oxidants, and has various effects on cell cycle, apoptosis and signal transduction. We studied the effects of NH2Cl on DNA repair response induced by ultraviolet B (UVB) irradiation in normal human diploid fibroblasts, TIG-1. TIG-1 irradiated with 20 mJ/cm2 UVB showed marked increase in thymine dimer, which decreased by about 50% after 24 h. This decrease in thymine dimer was significantly attenuated (P < 0.05) by the pretreatment of NH2Cl (200 microM), which indicated DNA repair inhibition. UVB induced p53 phosphorylation at Ser15, Ser20 and Ser37, and p53 accumulation, and NH2Cl also inhibited these changes. Consequently, UVB-induced increase in the downstream effectors of p53, namely p21Cip1 and Gadd45a, were almost completely inhibited by NH2Cl. Immunoprecipitation study indicated that the association of p53 and MDM2, an E3 ubiquitin ligase for p53, did not change substantially by NH2Cl and/or UVB. The phosphorylation of p53 (Ser15 and Ser37) by UVB is catalyzed by ATR (ataxia telangiectasia mutated and Rad3 related kinase), which works as DNA damage sensor, and ATR also phosphorylates checkpoint kinase 1(Chk1) at Ser345. NH2Cl also inhibited the phosphorylation of Chk1 (Ser345). As UVB-induced DNA damage is repaired by nucleotide excision repair (NER) in human cells, these findings indicated that NH2Cl inhibited NER through the inhibition of p53 phosphorylation and accumulation, and NH2Cl probably impaired DNA damage recognition and/or ATR activation. NH2Cl may facilitate carcinogenesis through the inhibition of NER that repairs DNA damages from various carcinogens.
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Affiliation(s)
- Kazuhisa Hiramatsu
- Department of Pathological Research, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata, Okayama 700-8558, Japan
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38
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Pagano G, Degan P, d'Ischia M, Kelly FJ, Nobili B, Pallardó FV, Youssoufian H, Zatterale A. Oxidative stress as a multiple effector in Fanconi anaemia clinical phenotype. Eur J Haematol 2005; 75:93-100. [PMID: 16000125 DOI: 10.1111/j.1600-0609.2005.00507.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Fanconi anaemia (FA) is a genetic disease characterised by bone marrow failure with excess risk of myelogenous leukaemia and solid tumours. A widely accepted notion in FA research invokes a deficiency of response to DNA damage as the fundamental basis of the 'crosslinker sensitivity' observed in this disorder. However, such an isolated defect cannot readily account for the full cellular and clinical phenotype, which includes a number of other abnormalities, such as malformations, endocrinopathies, and typical skin spots. An extensive body of evidence pointing toward an involvement of oxidative stress in the FA phenotype includes the following: (i) In vitro and ex vivo abnormalities in a number of redox status endpoints; (ii) the functions of several FA proteins in protecting cells from oxidative stress; (iii) redox-related toxicity mechanisms of the xenobiotics evoking excess toxicity in FA cells. The clinical features in FA and the in vivo abnormalities of redox parameters are here reconsidered in view of the pleiotropic clinical phenotype and known biochemical and molecular links to an in vivo prooxidant state, which causes oxidative damage to biomolecules, resulting in an excessive number of acquired abnormalities that may overwhelm the cellular repair capacity rather than a primary deficiency in DNA repair. FA may thus represent a unique model disease in testing the integration between the acquisition of macromolecular damage as a result of oxidative stress and the ability of the mammalian cell to respond effectively to such damage.
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Affiliation(s)
- Giovanni Pagano
- Centre for Research, Innovation and Technological Transfer in Oncology and Life Sciences, Mercogliano (AV), Italy.
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Pagano G, Zatterale A, Degan P, d'Ischia M, Kelly FJ, Pallardó FV, Kodama S. Multiple Involvement of Oxidative Stress in Werner Syndrome Phenotype. Biogerontology 2005; 6:233-43. [PMID: 16333757 DOI: 10.1007/s10522-005-2624-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2005] [Accepted: 06/23/2005] [Indexed: 01/12/2023]
Abstract
Werner syndrome is a genetic disease characterized by early ageing, excess cancer risk, high incidence of type II diabetes mellitus, early atherosclerosis, ocular cataracts, and osteoporosis. The protein encoded by the defective gene, WRN (WRNp) associates with three activities, that is, a RecQ DNA helicase, 3'-5'-exonuclease and ATPase activities. By highlighting the DNA helicase activity, a widespread consensus in WS-associated defect(s) has been established, pointing toward a deficiency in maintaining DNA integrity. However, a possible involvement of redox pathways in WS may be suggested by several lines of evidence that include: (i) the multiple functions and interactions of WRNp with oxidative stress-related activities and factors; (ii) the pleiotropic WS clinical phenotype encompassing a number of oxidative stress-related pathologies; (iii) redox-related toxicity mechanisms of several xenobiotics exerting excess toxicity in WS cells; (iv) recent in vivo and in vitro findings of redox abnormalities in WS patients and in WS cells. The working hypothesis is raised that a deficiency in WRNp, and the pleiotropic clinical phenotype in WS patients may provide the basis to envision an underlying in vivo prooxidant state, which causes oxidative damage to biomolecules, with multiple oxidative stress-related alterations, resulting in multi-faceted clinical consequences.
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Affiliation(s)
- Giovanni Pagano
- Italian National Cancer Institute, G. Pascale Foundation, I-80131 Naples, Italy.
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40
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O'Reilly MA. Redox activation of p21Cip1/WAF1/Sdi1: a multifunctional regulator of cell survival and death. Antioxid Redox Signal 2005; 7:108-18. [PMID: 15650400 DOI: 10.1089/ars.2005.7.108] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Cell division requires the coordinated assembly of cyclins and cyclin-dependent kinases that promote cell-cycle progression through S phase and mitosis. Two families of cyclin-dependent kinase inhibitors prevent abnormal or premature proliferation by blocking cyclin kinase activity. Expression of the cyclin-dependent kinase inhibitor p21, a member of the Cip/Kip family, increases when cells are damaged. In addition to controlling cell-cycle progression, p21 participates in DNA repair and apoptotic processes. The recent appreciation that p21 regulates cell survival and death implies that it is a master regulator of cell fate. This review discusses how p21 can affect the cellular response to oxidative stress.
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Affiliation(s)
- Michael A O'Reilly
- Department of Pediatrics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA.
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