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Boyd RA, Majumder S, Stiban J, Mavodza G, Straus AJ, Kempelingaiah SK, Reddy V, Hannun YA, Obeid LM, Senkal CE. The heat shock protein Hsp27 controls mitochondrial function by modulating ceramide generation. Cell Rep 2023; 42:113081. [PMID: 37689067 PMCID: PMC10591768 DOI: 10.1016/j.celrep.2023.113081] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 07/24/2023] [Accepted: 08/18/2023] [Indexed: 09/11/2023] Open
Abstract
Sphingolipids have key functions in membrane structure and cellular signaling. Ceramide is the central molecule of the sphingolipid metabolism and is generated by ceramide synthases (CerS) in the de novo pathway. Despite their critical function, mechanisms regulating CerS remain largely unknown. Using an unbiased proteomics approach, we find that the small heat shock protein 27 (Hsp27) interacts specifically with CerS1 but not other CerS. Functionally, our data show that Hsp27 acts as an endogenous inhibitor of CerS1. Wild-type Hsp27, but not a mutant deficient in CerS1 binding, inhibits CerS1 activity. Additionally, silencing of Hsp27 enhances CerS1-generated ceramide accumulation in cells. Moreover, phosphorylation of Hsp27 modulates Hsp27-CerS1 interaction and CerS1 activity in acute stress-response conditions. Biologically, we show that Hsp27 knockdown impedes mitochondrial function and induces lethal mitophagy in a CerS1-dependent manner. Overall, we identify an important mode of CerS1 regulation and CerS1-mediated mitophagy through protein-protein interaction with Hsp27.
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Affiliation(s)
- Rowan A Boyd
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23398, USA
| | - Saurav Majumder
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23398, USA
| | - Johnny Stiban
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23398, USA; Department of Biology and Biochemistry, Birzeit University, Ramallah, Palestine
| | - Grace Mavodza
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23398, USA
| | - Alexandra J Straus
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23398, USA
| | - Sachin K Kempelingaiah
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23398, USA
| | - Varun Reddy
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Yusuf A Hannun
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA; Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY 11794, USA
| | - Lina M Obeid
- Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY 11794, USA; Northport Veterans Affairs Medical Center, Northport, NY 11768, USA
| | - Can E Senkal
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23398, USA; Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23398, USA.
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2
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Radiosensitisation of SCCVII tumours and normal tissues in mice by the DNA-dependent protein kinase inhibitor AZD7648. Radiother Oncol 2021; 166:162-170. [PMID: 34861268 DOI: 10.1016/j.radonc.2021.11.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 10/18/2021] [Accepted: 11/22/2021] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND PURPOSE Inhibitors of DNA-dependent protein kinase (DNA-PK) are effective radiation sensitisers in preclinical tumours, but little is known about risks of normal tissue radiosensitisation. Here, we evaluate radiosensitisation of head and neck squamous cell carcinoma (HNSCC) cells by DNA-PK inhibitor AZD7648 under oxia and anoxia in vitro, and tumour (SCCVII), oral mucosa and small intestine in mice. MATERIALS AND METHODS Radiosensitisation of human (UT-SCC-54C) and murine (SCCVII) HNSCC cells by AZD7648 under oxia and anoxia was evaluated by clonogenic assay. Radiosensitisation of SCCVII tumours in C3H mice by oral AZD7648 (75 mg/kg) was determined by ex vivo clonogenic assay 3.5 days post-irradiation, with evaluation of normal tissue surrogate endpoints using 5-ethynyl-2'-deoxyuridine to facilitate detection of regenerating crypts in the ileum and repopulating S-phase cells in the ileum and oral mucosa of the same animals. RESULTS AZD7648 potently radiosensitised both cell lines, with similar sensitiser enhancement ratios for 10% survival (SER10) under oxia and anoxia. AZD7648 diffused rapidly through multicellular layers, suggesting rapid equilibration between plasma and hypoxic zones in tumours. SCCVII tumours were radiosensitised by AZD7648 (SER10 2.5). AZD7648 also enhanced radiation-induced body weight loss and suppressed regenerating intestinal crypts and repopulating S-phase cells in the ileum and tongue epithelium with SER values similar to SCCVII tumours. CONCLUSION AZD7648 is a potent radiation sensitiser of both oxic and anoxic tumour cells, but also markedly radiosensitises stem cells in the small intestine and oral mucosa.
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Vanillin derivative VND3207 activates DNA-PKcs conferring protection against radiation-induced intestinal epithelial cells injury in vitro and in vivo. Toxicol Appl Pharmacol 2019; 387:114855. [PMID: 31830491 DOI: 10.1016/j.taap.2019.114855] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 12/05/2019] [Accepted: 12/07/2019] [Indexed: 12/20/2022]
Abstract
Vanillin is a natural compound endowed with antioxidant and anti-mutagenic properties. We previously identified the vanillin derivative VND3207 with strong radio-protective and antioxidant effects and found that VND3207 confers survival benefit and protection against radiation-induced intestinal injury (RIII) in mice. We also observed that VND3207 treatment enhanced the expression level of the catalytic subunit of the DNA-dependent protein kinase (DNA-PKcs) in human lymphoblastoid cells with or without γ-irradiation. DNA-PKcs is a critical component of DNA double strand break repair pathway and also regulates mitotic progression by stabilizing spindle formation and preventing mitotic catastrophe in response to DNA damage. In the present study, we found that VND3207 protected intestinal epithelial cells in vitro against ionizing radiation by promoting cell proliferation and inhibiting cell apoptosis. In addition, VND3207 promoted DNA-PKcs activity by increasing autophosphorylation at S2056 site. Consistent with this, VND3207 significantly decreased the number of γH2AX foci and mitotic catastrophe after radiation. DNA-PKcs deficiency abolished these VND3207 radio-protective effects, indicating that DNA-PKcs activation is essential for VND3207 activity. In conclusion, VND3207 promoted intestinal repair following radiation injury by regulating the DNA-PKcs pathway.
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Gangeh MJ, Hashim A, Giles A, Sannachi L, Czarnota GJ. Computer aided prognosis for cell death categorization and prediction in vivo using quantitative ultrasound and machine learning techniques. Med Phys 2017; 43:6439. [PMID: 27908167 DOI: 10.1118/1.4967265] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
PURPOSE At present, a one-size-fits-all approach is typically used for cancer therapy in patients. This is mainly because there is no current imaging-based clinical standard for the early assessment and monitoring of cancer treatment response. Here, the authors have developed, for the first time, a complete computer-aided-prognosis (CAP) system based on multiparametric quantitative ultrasound (QUS) spectroscopy methods in association with texture descriptors and advanced machine learning techniques. This system was used to noninvasively categorize and predict cell death levels in fibrosarcoma mouse tumors treated using ultrasound-stimulated microbubbles as novel endothelial-cell radiosensitizers. METHODS Sarcoma xenograft tumor-bearing mice were treated using ultrasound-stimulated microbubbles, alone or in combination with x-ray radiation therapy, as a new antivascular treatment. Therapy effects were assessed at 2-3, 24, and 72 h after treatment using a high-frequency ultrasound. Two-dimensional spectral parametric maps were generated using the power spectra of the raw radiofrequency echo signal. Subsequently, the distances between "pretreatment" and "post-treatment" scans were computed as an indication of treatment efficacy, using a kernel-based metric on textural features extracted from 2D parametric maps. A supervised learning paradigm was used to either categorize cell death levels as low, medium, or high using a classifier, or to "continuously" predict the levels of cell death using a regressor. RESULTS The developed CAP system performed at a high level for the classification of cell death levels. The area under curve of the receiver operating characteristic was 0.87 for the classification of cell death levels to both low/medium and medium/high levels. Moreover, the prediction of cell death levels using the proposed CAP system achieved a good correlation (r = 0.68, p < 0.001) with histological cell death levels as the ground truth. A statistical test of significance between individual treatment groups with the corresponding control group demonstrated that the predicted levels indicated the same significant changes in cell death as those indicated by the ground-truth levels. CONCLUSIONS The technology developed in this study addresses a gap in the current standard of care by introducing a quality control step that generates potentially actionable metrics needed to enhance treatment decision-making. The study establishes a noninvasive framework for quantifying levels of cancer treatment response developed preclinically in tumors using QUS imaging in conjunction with machine learning techniques. The framework can potentially facilitate the detection of refractory responses in patients to a certain cancer treatment early on in the course of therapy to enable switching to more efficacious treatments.
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Affiliation(s)
- M J Gangeh
- Departments of Medical Biophysics, and Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9, Canada and Departments of Radiation Oncology, and Imaging Research - Physical Sciences, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada
| | - A Hashim
- Imaging Research and Physical Sciences, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada
| | - A Giles
- Imaging Research and Physical Sciences, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada
| | - L Sannachi
- Departments of Medical Biophysics, and Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9, Canada and Departments of Radiation Oncology, and Imaging Research - Physical Sciences, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada
| | - G J Czarnota
- Departments of Medical Biophysics, and Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9, Canada and Departments of Radiation Oncology, and Imaging Research - Physical Sciences, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada
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Xu R, Wang K, Mileva I, Hannun YA, Obeid LM, Mao C. Alkaline ceramidase 2 and its bioactive product sphingosine are novel regulators of the DNA damage response. Oncotarget 2017; 7:18440-57. [PMID: 26943039 PMCID: PMC4951300 DOI: 10.18632/oncotarget.7825] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 01/29/2016] [Indexed: 12/17/2022] Open
Abstract
Human cells respond to DNA damage by elevating sphingosine, a bioactive sphingolipid that induces programmed cell death (PCD) in response to various forms of stress, but its regulation and role in the DNA damage response remain obscure. Herein we demonstrate that DNA damage increases sphingosine levels in tumor cells by upregulating alkaline ceramidase 2 (ACER2) and that the upregulation of the ACER2/sphingosine pathway induces PCD in response to DNA damage by increasing the production of reactive oxygen species (ROS). Treatment with the DNA damaging agent doxorubicin increased both ACER2 expression and sphingosine levels in HCT116 cells in a dose-dependent manner. ACER2 overexpression increased sphingosine in HeLa cells whereas knocking down ACER2 inhibited the doxorubicin-induced increase in sphingosine in HCT116 cells, suggesting that DNA damage elevates sphingosine by upregulating ACER2. Knocking down ACER2 inhibited an increase in the apoptotic and necrotic cell population and the cleavage of poly ADP ribose polymerase (PARP) in HCT116 cells in response to doxorubicin as well as doxorubicin-induced release of lactate dehydrogenase (LDH) from these cells. Similar to treatment with doxorubicin, ACER2 overexpression induced an increase in the apoptotic and necrotic cell population and PARP cleavage in HeLa cells and LDH release from cells, suggesting that ACER2 upregulation mediates PCD in response to DNA damage through sphingosine. Mechanistic studies demonstrated that the upregulation of the ACER2/sphingosine pathway induces PCD by increasing ROS levels. Taken together, these results suggest that the ACER2/sphingosine pathway mediates PCD in response to DNA damage through ROS production.
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Affiliation(s)
- Ruijuan Xu
- Department of Medicine, State University of New York at Stony Brook, Stony Brook, NY 11794, USA.,Stony Brook Cancer Center, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
| | - Kai Wang
- Department of Medicine, State University of New York at Stony Brook, Stony Brook, NY 11794, USA.,Stony Brook Cancer Center, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
| | - Izolda Mileva
- Lipidomics Core Facility, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
| | - Yusuf A Hannun
- Department of Medicine, State University of New York at Stony Brook, Stony Brook, NY 11794, USA.,Stony Brook Cancer Center, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
| | - Lina M Obeid
- Department of Medicine, State University of New York at Stony Brook, Stony Brook, NY 11794, USA.,Stony Brook Cancer Center, State University of New York at Stony Brook, Stony Brook, NY 11794, USA.,Ralph H. Johnson Veterans Administration Hospital, Stony Brook, NY 11794, USA
| | - Cungui Mao
- Department of Medicine, State University of New York at Stony Brook, Stony Brook, NY 11794, USA.,Stony Brook Cancer Center, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
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6
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Herskind C, Ma L, Liu Q, Zhang B, Schneider F, Veldwijk MR, Wenz F. Biology of high single doses of IORT: RBE, 5 R's, and other biological aspects. Radiat Oncol 2017; 12:24. [PMID: 28107823 PMCID: PMC5251326 DOI: 10.1186/s13014-016-0750-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 12/21/2016] [Indexed: 01/14/2023] Open
Abstract
Intraoperative radiotherapy differs from conventional, fractionated radiotherapy in several aspects that may influence its biological effect. The radiation quality influences the relative biologic effectiveness (RBE), and the role of the five R’s of radiotherapy (reassortment, repair, reoxygenation, repopulation, radiosensitivity) is different. Furthermore, putative special biological effects and the small volume receiving a high single dose may be important. The present review focuses on RBE, repair, and repopulation, and gives an overview of the other factors that potentially contribute to the efficacy. The increased RBE should be taken into account for low-energy X-rays while evidence of RBE < 1 for high-energy electrons at higher doses is presented. Various evidence supports a hypothesis that saturation of the primary DNA double-strand break (DSB) repair mechanisms leads to increasing use of an error-prone backup repair system leading to genomic instability that may contribute to inactivate tumour cells at high single doses. Furthermore, the elimination of repopulation of residual tumour cells in the tumour bed implies that some patients are likely to have very few residual tumour cells which may be cured even by low doses to the tumour bed. The highly localised dose distribution of IORT has the potential to inactivate tumour cells while sparing normal tissue by minimising the volume exposed to high doses. Whether special effects of high single doses also contribute to the efficacy will require further experimental and clinical studies.
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Affiliation(s)
- Carsten Herskind
- Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
| | - Lin Ma
- Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.,Present Address: Department of Radiation Oncology, University of California, San Francisco, CA, USA
| | - Qi Liu
- Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.,Present Address: Department of Radiation Oncology, University of California, San Francisco, CA, USA
| | - Bo Zhang
- Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.,Present Address: Department of Oncology at No. 2 Hospital Anhui Medical University, and School of Life Sciences, Anhui Medical University, Hefei, Anhui, China
| | - Frank Schneider
- Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Marlon R Veldwijk
- Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Frederik Wenz
- Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
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7
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Chandrakesan P, May R, Weygant N, Qu D, Berry WL, Sureban SM, Ali N, Rao C, Huycke M, Bronze MS, Houchen CW. Intestinal tuft cells regulate the ATM mediated DNA Damage response via Dclk1 dependent mechanism for crypt restitution following radiation injury. Sci Rep 2016; 6:37667. [PMID: 27876863 PMCID: PMC5120335 DOI: 10.1038/srep37667] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 11/01/2016] [Indexed: 12/18/2022] Open
Abstract
Crypt epithelial survival and regeneration after injury require highly coordinated complex interplay between resident stem cells and diverse cell types. The function of Dclk1 expressing tuft cells regulating intestinal epithelial DNA damage response for cell survival/self-renewal after radiation-induced injury is unclear. Intestinal epithelial cells (IECs) were isolated and purified and utilized for experimental analysis. We found that small intestinal crypts of VillinCre;Dclk1f/f mice were hypoplastic and more apoptotic 24 h post-total body irradiation, a time when stem cell survival is p53-independent. Injury-induced ATM mediated DNA damage response, pro-survival genes, stem cell markers, and self-renewal ability for survival and restitution were reduced in the isolated intestinal epithelial cells. An even greater reduction in these signaling pathways was observed 3.5 days post-TBI, when peak crypt regeneration occurs. We found that interaction with Dclk1 is critical for ATM and COX2 activation in response to injury. We determined that Dclk1 expressing tuft cells regulate the whole intestinal epithelial cells following injury through paracrine mechanism. These findings suggest that intestinal tuft cells play an important role in regulating the ATM mediated DNA damage response, for epithelial cell survival/self-renewal via a Dclk1 dependent mechanism, and these processes are indispensable for restitution and function after severe radiation-induced injury.
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Affiliation(s)
- Parthasarathy Chandrakesan
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,OU Cancer Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,Department of Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
| | - Randal May
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,Department of Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
| | - Nathaniel Weygant
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Dongfeng Qu
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,OU Cancer Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - William L Berry
- OU Cancer Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Sripathi M Sureban
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,Department of Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
| | - Naushad Ali
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,Department of Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
| | - Chinthalapally Rao
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,OU Cancer Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Mark Huycke
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,Department of Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
| | - Michael S Bronze
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Courtney W Houchen
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,OU Cancer Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,Department of Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA.,COARE Biotechnology, Inc., Oklahoma City, OK 73104, USA
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8
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Herskind C, Talbot CJ, Kerns SL, Veldwijk MR, Rosenstein BS, West CML. Radiogenomics: A systems biology approach to understanding genetic risk factors for radiotherapy toxicity? Cancer Lett 2016; 382:95-109. [PMID: 26944314 PMCID: PMC5016239 DOI: 10.1016/j.canlet.2016.02.035] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 02/17/2016] [Accepted: 02/19/2016] [Indexed: 02/06/2023]
Abstract
Adverse reactions in normal tissue after radiotherapy (RT) limit the dose that can be given to tumour cells. Since 80% of individual variation in clinical response is estimated to be caused by patient-related factors, identifying these factors might allow prediction of patients with increased risk of developing severe reactions. While inactivation of cell renewal is considered a major cause of toxicity in early-reacting normal tissues, complex interactions involving multiple cell types, cytokines, and hypoxia seem important for late reactions. Here, we review 'omics' approaches such as screening of genetic polymorphisms or gene expression analysis, and assess the potential of epigenetic factors, posttranslational modification, signal transduction, and metabolism. Furthermore, functional assays have suggested possible associations with clinical risk of adverse reaction. Pathway analysis incorporating different 'omics' approaches may be more efficient in identifying critical pathways than pathway analysis based on single 'omics' data sets. Integrating these pathways with functional assays may be powerful in identifying multiple subgroups of RT patients characterised by different mechanisms. Thus 'omics' and functional approaches may synergise if they are integrated into radiogenomics 'systems biology' to facilitate the goal of individualised radiotherapy.
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Affiliation(s)
- Carsten Herskind
- Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Germany.
| | | | - Sarah L Kerns
- Department of Radiation Oncology, Mount Sinai School of Medicine, New York, USA; Department of Radiation Oncology, University of Rochester Medical Center, Rochester, USA
| | - Marlon R Veldwijk
- Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Germany
| | - Barry S Rosenstein
- Department of Radiation Oncology, Mount Sinai School of Medicine, New York, USA; Department of Radiation Oncology, New York University School of Medicine, USA; Department of Dermatology, Mount Sinai School of Medicine, New York, USA
| | - Catharine M L West
- Institute of Cancer Sciences, University of Manchester, Christie Hospital, Manchester, UK
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9
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Wei L, Leibowitz BJ, Wang X, Epperly M, Greenberger J, Zhang L, Yu J. Inhibition of CDK4/6 protects against radiation-induced intestinal injury in mice. J Clin Invest 2016; 126:4076-4087. [PMID: 27701148 DOI: 10.1172/jci88410] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 08/25/2016] [Indexed: 12/12/2022] Open
Abstract
Radiotherapy causes dose-limiting toxicity and long-term complications in rapidly renewing tissues, including the gastrointestinal tract. Currently, there is no FDA-approved agent for the prevention or treatment of radiation-induced intestinal injury. In this study, we have shown that PD 0332991 (PD), an FDA-approved selective inhibitor of cyclin-dependent kinase 4/6 (CDK4/6), prevents radiation-induced lethal intestinal injury in mice. Treating mice with PD or a structurally distinct CDK4/6 inhibitor prior to radiation blocked proliferation and crypt apoptosis and improved crypt regeneration. PD treatment also enhanced LGR5+ stem cell survival and regeneration after radiation. PD was an on-target inhibitor of RB phosphorylation and blocked G1/S transition in the intestinal crypts. PD treatment strongly but reversibly inhibited radiation-induced p53 activation, which blocked p53-upregulated modulator of apoptosis-dependent (PUMA-dependent) apoptosis without affecting p21-dependent suppression of DNA damage accumulation, with a repair bias toward nonhomologous end joining. Further, deletion of PUMA synergized with PD treatment for even greater intestinal radioprotection. Our results demonstrate that the cell cycle critically regulates the DNA damage response and survival of intestinal stem cells and support the concept that pharmacological quiescence is a potentially highly effective and selective strategy for intestinal radioprotection.
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10
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Singh VK, Romaine PLP, Newman VL, Seed TM. Medical countermeasures for unwanted CBRN exposures: part II radiological and nuclear threats with review of recent countermeasure patents. Expert Opin Ther Pat 2016; 26:1399-1408. [PMID: 27610458 PMCID: PMC5152556 DOI: 10.1080/13543776.2016.1231805] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Introduction: The global threat of a chemical, biological, radiological, or nuclear (CBRN) disaster is an important priority for all government agencies involved in domestic security and public health preparedness. Radiological/nuclear (RN) attacks or accidents have become a larger focus of the United States Food and Drug administration (US FDA) over time because of their increased likeliness. Clinical signs and symptoms of a developing acute radiation syndrome (ARS) are grouped into three sub-syndromes named for the dominant organ system affected, namely the hematopoietic (H-ARS), gastrointestinal (GI-ARS), and neurovascular systems. The availability of safe and effective countermeasures against radiological/nuclear threats currently represents a significant unmet medical need. Areas covered: This article reviews the development of RN threat medical countermeasures and highlights those specific countermeasures that have been recently patented and approved following the FDA Animal Rule. Patents for such agents from 2015 have been presented. Expert opinion: Two granulocyte colony-stimulating factor (G-CSF)-based radiation countermeasures (Neupogen® (Amgen, Thousand Oaks, CA) and Neulasta® (Amgen, Thousand Oaks, CA)) have recently been approved by the FDA for treatment of H-ARS and both these agents are radiomitigators, used after radiation exposure. To date, there are no FDA-approved radioprotectors for ARS.
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Affiliation(s)
- Vijay K Singh
- a Department of Pharmacology and Molecular Therapeutics , F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences , Bethesda , MD , USA.,b Armed Forces Radiobiology Research Institute , Uniformed Services University of the Health Sciences , Bethesda , MD , USA
| | - Patricia L P Romaine
- b Armed Forces Radiobiology Research Institute , Uniformed Services University of the Health Sciences , Bethesda , MD , USA
| | - Victoria L Newman
- b Armed Forces Radiobiology Research Institute , Uniformed Services University of the Health Sciences , Bethesda , MD , USA
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11
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Zhang Y, Huang Y, Cantalupo A, Azevedo PS, Siragusa M, Bielawski J, Giordano FJ, Di Lorenzo A. Endothelial Nogo-B regulates sphingolipid biosynthesis to promote pathological cardiac hypertrophy during chronic pressure overload. JCI Insight 2016; 1. [PMID: 27158676 DOI: 10.1172/jci.insight.85484] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
We recently discovered that endothelial Nogo-B, a membrane protein of the ER, regulates vascular function by inhibiting the rate-limiting enzyme, serine palmitoyltransferase (SPT), in de novo sphingolipid biosynthesis. Here, we show that endothelium-derived sphingolipids, particularly sphingosine-1-phosphate (S1P), protect the heart from inflammation, fibrosis, and dysfunction following pressure overload and that Nogo-B regulates this paracrine process. SPT activity is upregulated in banded hearts in vivo as well as in TNF-α-activated endothelium in vitro, and loss of Nogo removes the brake on SPT, increasing local S1P production. Hence, mice lacking Nogo-B, systemically or specifically in the endothelium, are resistant to the onset of pathological cardiac hypertrophy. Furthermore, pharmacological inhibition of SPT with myriocin restores permeability, inflammation, and heart dysfunction in Nogo-A/B-deficient mice to WT levels, whereas SEW2871, an S1P1 receptor agonist, prevents myocardial permeability, inflammation, and dysfunction in WT banded mice. Our study identifies a critical role of endothelial sphingolipid biosynthesis and its regulation by Nogo-B in the development of pathological cardiac hypertrophy and proposes a potential therapeutic target for the attenuation or reversal of this clinical condition.
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Affiliation(s)
- Yi Zhang
- Center for Vascular Biology, Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, Cornell University, New York, New York, USA
| | - Yan Huang
- Section of Cardiovascular Medicine, Department of Internal Medicine, and Vascular Biology and Therapeutic Program, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Anna Cantalupo
- Center for Vascular Biology, Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, Cornell University, New York, New York, USA
| | - Paula S Azevedo
- Department of Internal Medicine, Botucatu Medical School, University of Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Mauro Siragusa
- Center for Molecular Medicine, Institute for Vascular Signalling, Goethe University Frankfurt, Frankfurt, Germany
| | - Jacek Bielawski
- Lipidomics Mass Spectrometry Facility, Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Frank J Giordano
- Section of Cardiovascular Medicine, Department of Internal Medicine, and Vascular Biology and Therapeutic Program, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Annarita Di Lorenzo
- Center for Vascular Biology, Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, Cornell University, New York, New York, USA
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12
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Li M, Gu Y, Ma YC, Shang ZF, Wang C, Liu FJ, Cao JP, Wan HJ, Zhang XG. Krüppel-Like Factor 5 Promotes Epithelial Proliferation and DNA Damage Repair in the Intestine of Irradiated Mice. Int J Biol Sci 2015; 11:1458-68. [PMID: 26681925 PMCID: PMC4672003 DOI: 10.7150/ijbs.13444] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/01/2015] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND & AIMS: High doses of radiation induce severe DNA damage in intestinal epithelial cells, especially crypt cells, and cause intestinal injury, but the underlying molecular mechanisms remain unclear. Krüppel-like factor 5 (KLF5), a zinc finger-containing transcription factor, is induced by various stress stimuli and is involved in cell proliferation and survival. The role of KLF5 in radiation-induced intestinal injury was investigated here. METHODS: Wild type mice were treated with 8 or 15 Gy total body irradiation (TBI). KLF5 content and cellular localization in the small intestines of irradiated mice were detected by Western blot and immunohistochemical analysis. Mice with intestinal-specific knockdown of KLF5 (Vil-Cre; Klf5fl/+ mice) were generated and their response to radiation was compared with controls. Morphological changes were determined by hematoxylin and eosin staining. Proliferation was examined by Ki67 immunostaining. The molecular response of the small intestine after KLF5 knockdown was investigated using microarrays. RESULTS: KLF5 expression correlated with the progression of intestinal damage. Decreased levels of KLF5 in the gut were associated with increased damage to the intestinal mucosa and reduced epithelial proliferation after TBI. Our microarray data disclosed that KLF5 knockdown down-regulated genes related to DNA damage repair pathways such as nucleotide excision repair, mismatch repair, non-homologous end joining and the Fanconi anemia pathway, which may suggest a novel function of KLF5. CONCLUSIONS: Our study illustrates that KLF5 may modulate DNA repair pathways to prevent intestinal injury induced by TBI. KLF5 signaling provides a novel field for identification of potential therapeutic targets for the treatment of radiation-induced intestinal damage.
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Affiliation(s)
- Ming Li
- 1. School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, Jiangsu 215123, China ; 2. Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, China
| | - Yuan Gu
- 1. School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, Jiangsu 215123, China ; 2. Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, China
| | - Yan-Chao Ma
- 3. Institute of Medical Biotechnology, Medical College of Soochow University, Suzhou, Jiangsu 215007, China ; 4. Jiangsu Stem Cell Key Laboratory, Medical College of Soochow University, Suzhou, Jiangsu 215007, China
| | - Zeng-Fu Shang
- 1. School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, Jiangsu 215123, China ; 2. Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, China
| | - Chang Wang
- 1. School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, Jiangsu 215123, China ; 2. Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, China
| | - Fen-Ju Liu
- 1. School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, Jiangsu 215123, China ; 2. Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, China
| | - Jian-Ping Cao
- 1. School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou, Jiangsu 215123, China ; 2. Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu 215123, China
| | - Hua-Jing Wan
- 5. Key Laboratory of Obstetric, Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, West China Institute of Women and Children's Health, and Department of Pediatrics, Huaxi Second University Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Xue-Guang Zhang
- 3. Institute of Medical Biotechnology, Medical College of Soochow University, Suzhou, Jiangsu 215007, China ; 4. Jiangsu Stem Cell Key Laboratory, Medical College of Soochow University, Suzhou, Jiangsu 215007, China
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13
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Yu J. Intestinal stem cell injury and protection during cancer therapy. Transl Cancer Res 2013; 2:384-396. [PMID: 24683536 PMCID: PMC3966653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Radiation and chemotherapy remain the most effective and widely used cancer treatments. These treatments cause DNA damage and selectively target rapidly proliferating cells such as cancer cells, as well as inevitably cause damage to normal tissues, particularly those undergoing rapid self renewal. The side effects associated with radiation and chemotherapy are most pronounced in the hematopoietic (HP) system and gastrointestinal (GI) tract. These tissues are fast renewing and have a well-defined stem cell compartment that plays an essential role in homeostasis, and in treatment-induced acute injury that is dose limiting. Using recently defined intestinal stem cell markers and mouse models, a great deal of insight has been gained in the biology of intestinal stem cells (ISCs), which will undoubtedly help further mechanistic understanding of their injury. This review will cover historic discoveries and recent advances in the identification and characterization of intestinal stem cells, their responses to genotoxic stress, and a new crypt and intestinal stem cell culture system. The discussion will include key pathways regulating intestinal crypt and stem cell injury and regeneration caused by cancer treatments, and strategies for their protection. The focus will be on the acute phase of cell killing in mouse radiation models, where our understanding of the mechanisms in relation to intestinal stem cells is most advanced and interventions appear most effective.
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Affiliation(s)
- Jian Yu
- Departments of Pathology and Radiation Oncology, University of Pittsburgh School of Medicine, University of Pittsburgh Cancer Institute Pittsburgh, PA 15213, USA
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Hage-Sleiman R, Esmerian MO, Kobeissy H, Dbaibo G. p53 and Ceramide as Collaborators in the Stress Response. Int J Mol Sci 2013; 14:4982-5012. [PMID: 23455468 PMCID: PMC3634419 DOI: 10.3390/ijms14034982] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 01/22/2013] [Accepted: 02/01/2013] [Indexed: 02/08/2023] Open
Abstract
The sphingolipid ceramide mediates various cellular processes in response to several extracellular stimuli. Some genotoxic stresses are able to induce p53-dependent ceramide accumulation leading to cell death. However, in other cases, in the absence of the tumor suppressor protein p53, apoptosis proceeds partly due to the activity of this "tumor suppressor lipid", ceramide. In the current review, we describe ceramide and its roles in signaling pathways such as cell cycle arrest, hypoxia, hyperoxia, cell death, and cancer. In a specific manner, we are elaborating on the role of ceramide in mitochondrial apoptotic cell death signaling. Furthermore, after highlighting the role and mechanism of action of p53 in apoptosis, we review the association of ceramide and p53 with respect to apoptosis. Strikingly, the hypothesis for a direct interaction between ceramide and p53 is less favored. Recent data suggest that ceramide can act either upstream or downstream of p53 protein through posttranscriptional regulation or through many potential mediators, respectively.
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Affiliation(s)
- Rouba Hage-Sleiman
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Infectious Diseases, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236 Riad El Solh, 1107 2020 Beirut, Lebanon; E-Mails: (M.O.E.); (G.D.)
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236 Riad El Solh, 1107 2020 Beirut, Lebanon; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +961-1-350-000 (ext. 4883)
| | - Maria O. Esmerian
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Infectious Diseases, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236 Riad El Solh, 1107 2020 Beirut, Lebanon; E-Mails: (M.O.E.); (G.D.)
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236 Riad El Solh, 1107 2020 Beirut, Lebanon; E-Mail:
| | - Hadile Kobeissy
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236 Riad El Solh, 1107 2020 Beirut, Lebanon; E-Mail:
| | - Ghassan Dbaibo
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Infectious Diseases, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236 Riad El Solh, 1107 2020 Beirut, Lebanon; E-Mails: (M.O.E.); (G.D.)
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236 Riad El Solh, 1107 2020 Beirut, Lebanon; E-Mail:
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15
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HUA GUOQIANG, THIN TINHTWE, FELDMAN REGINA, HAIMOVITZ-FRIEDMAN ADRIANA, CLEVERS HANS, FUKS ZVI, KOLESNICK RICHARD. Crypt base columnar stem cells in small intestines of mice are radioresistant. Gastroenterology 2012; 143:1266-1276. [PMID: 22841781 PMCID: PMC3480544 DOI: 10.1053/j.gastro.2012.07.106] [Citation(s) in RCA: 164] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 06/22/2012] [Accepted: 07/15/2012] [Indexed: 12/23/2022]
Abstract
BACKGROUND & AIMS Adult stem cells have been proposed to be quiescent and radiation resistant, repairing DNA double-strand breaks by nonhomologous end joining. However, the population of putative small intestinal stem cells (ISCs) at position +4 from the crypt base contradicts this model, in that they are highly radiosensitive. Cycling crypt base columnar cells (CBCs) at crypt positions +1-3 recently were defined as an alternative population of ISCs. Little is known about the sensitivity of this stem cell population to radiation. METHODS Radiation-induced lethality of CBCs was quantified kinetically in Lgr5-lacZ transgenic mice. γ-H2AX, BRCA1, RAD51, and DNA-PKcs foci were used as DNA repair surrogates to investigate the inherent ability of CBCs to recognize and repair double-strand breaks. 5-ethynyl-2'-deoxyuridine and 5-bromo-2'-deoxyuridine incorporation assays were used to study patterns of CBC growth arrest and re-initiation of cell cycling. Apoptosis was evaluated by caspase-3 staining. RESULTS CBCs are relatively radioresistant, repairing DNA by homologous recombination significantly more efficiently than transit amplifying progenitors or villus cells. CBCs undergo apoptosis less than 24 hours after irradiation (32% ± 2% of total lethality) or mitotic death at 24-48 hours. Survival of CBCs at 2 days predicts crypt regeneration at 3.5 days and lethality from gastrointestinal syndrome. Crypt repopulation originates from CBCs that survive irradiation. CONCLUSIONS Adult ISCs in mice can cycle rapidly yet still be radioresistant. Importantly, homologous recombination can protect adult stem cell populations from genotoxic stress. These findings broaden and refine concepts of the phenotype of adult stem cells.
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Affiliation(s)
- GUOQIANG HUA
- Laboratory of Signal Transduction, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - TIN HTWE THIN
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - REGINA FELDMAN
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York
| | | | - HANS CLEVERS
- Hubrecht Institute, KNAW and University Medical Center Utrecht, Uppsalalaan 8, 3584CT Utrecht, The Netherlands
| | - ZVI FUKS
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - RICHARD KOLESNICK
- Laboratory of Signal Transduction, Memorial Sloan-Kettering Cancer Center, New York, New York
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16
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El Kaffas A, Tran W, Czarnota GJ. Vascular Strategies for Enhancing Tumour Response to Radiation Therapy. Technol Cancer Res Treat 2012; 11:421-32. [DOI: 10.7785/tcrt.2012.500265] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Radiation therapy is prescribed to more than 50% of patients diagnosed with cancer. Although mechanisms of interaction between radiation and tumour cells are well understood on a molecular level, much remains uncertain concerning the interaction of radiation with the tumour as a whole. Recent studies have demonstrated that single large doses of radiation (8–20 Gy) may primarily target tumour endothelial cells, leading to secondary tumour clonogenic cell death. These studies suggest that blood vessels play an important role in radiation response. As a result, various strategies have been proposed to effectively combine radiation with vascular targeting agents. While most proposed schemes focus on methods to disrupt tumour blood vessels, recent evidence supporting that some anti-angiogenic agents may “normalize” tumour blood vessels, in turn enhancing tumour oxygenation and radiosensitivity, indicates that there may be more efficient strategies. Furthermore, vascular targeting agents have recently been demonstrated to enhance radiation therapy by targeting endothelial cells. When combined with radiation, these agents are believed to cause even more localized vascular destruction followed by tumour clonogenic cell death. Taken together, it is now crucial to elucidate the role of tumour blood vessels in radiation therapy response, in order to make use of this knowledge in developing therapeutic strategies that target tumour vasculature above and beyond classic clonogenic tumour cell death. In this report, we review some major developments in understanding the importance of tumour blood vessels during radiation therapy. A discussion of current imaging modalities used for studying vascular response to treatments will also be presented.
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Affiliation(s)
- Ahmed El Kaffas
- Department of Imaging Research, Sunnybrook Health Sciences Centre, 2075 Bayview Ave., Toronto, ON, Canada M4N 3M5
- Department of Medical Biophysics, University of Toronto, 2075 Bayview Ave., Toronto, ON, Canada M4N 3M5
| | - William Tran
- Department of Radiation Oncology, Sunnybrook Health Sciences Centre, 2075 Bayview Ave., Toronto, ON, Canada M4N 3M5
| | - Gregory J. Czarnota
- Department of Imaging Research, Sunnybrook Health Sciences Centre, 2075 Bayview Ave., Toronto, ON, Canada M4N 3M5
- Department of Medical Biophysics, University of Toronto, 2075 Bayview Ave., Toronto, ON, Canada M4N 3M5
- Department of Radiation Oncology, Sunnybrook Health Sciences Centre, 2075 Bayview Ave., Toronto, ON, Canada M4N 3M5
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17
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Pharmacological targeting of the thrombomodulin-activated protein C pathway mitigates radiation toxicity. Nat Med 2012; 18:1123-9. [PMID: 22729286 PMCID: PMC3491776 DOI: 10.1038/nm.2813] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 04/24/2012] [Indexed: 12/27/2022]
Abstract
Tissue damage induced by ionizing radiation in the hematopoietic and gastrointestinal systems is the major cause of lethality in radiological emergency scenarios and underlies some deleterious side effects in patients undergoing radiation therapy. The identification of target-specific interventions that confer radiomitigating activity is an unmet challenge. Here we identify the thrombomodulin (Thbd)-activated protein C (aPC) pathway as a new mechanism for the mitigation of total body irradiation (TBI)-induced mortality. Although the effects of the endogenous Thbd-aPC pathway were largely confined to the local microenvironment of Thbd-expressing cells, systemic administration of soluble Thbd or aPC could reproduce and augment the radioprotective effect of the endogenous Thbd-aPC pathway. Therapeutic administration of recombinant, soluble Thbd or aPC to lethally irradiated wild-type mice resulted in an accelerated recovery of hematopoietic progenitor activity in bone marrow and a mitigation of lethal TBI. Starting infusion of aPC as late as 24 h after exposure to radiation was sufficient to mitigate radiation-induced mortality in these mice. These findings suggest that pharmacologic augmentation of the activity of the Thbd-aPC pathway by recombinant Thbd or aPC might offer a rational approach to the mitigation of tissue injury and lethality caused by ionizing radiation.
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18
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Balagamwala EH, Chao ST, Suh JH. Principles of radiobiology of stereotactic radiosurgery and clinical applications in the central nervous system. Technol Cancer Res Treat 2012; 11:3-13. [PMID: 22181326 DOI: 10.7785/tcrt.2012.500229] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Stereotactic radiosurgery (SRS) has become an important treatment option for intracranial lesions and has recently been adapted to treat lesions outside the brain. Many studies have shown the effectiveness of SRS for the treatment of benign and metastatic tumors. Although DNA damage has been thought to be the principal form of radiation-induced damage, recent studies have shown that vascular endothelial damage is perhaps more important in the setting of high radiation doses per fraction such as those used in SRS. Furthermore, it has been shown that molecular responses to radiation differ based on dose per fraction. The principles of classical radiobiology are reviewed with explanation on why fractionation of radiotherapy allows optimization of the therapeutic ratio. The current understanding of the molecular responses that occur soon after the delivery of high radiation doses per fraction is also reviewed. A summary of current clinical evidence of radiation tolerance to SRS of brain, brainstem, optic chiasm and spinal cord is also provided. Recent advances in understanding the molecular basis of SRS response have uncovered a different biological response than previously thought. Further understanding of these molecular mechanisms will allow for the development of targeted radiosensitizers and radioprotectors to optimize the therapeutic ratio.
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Affiliation(s)
- E H Balagamwala
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, USA
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19
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Loh KC, Baldwin D, Saba JD. Sphingolipid signaling and hematopoietic malignancies: to the rheostat and beyond. Anticancer Agents Med Chem 2012; 11:782-93. [PMID: 21707493 DOI: 10.2174/187152011797655159] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 05/06/2011] [Accepted: 05/09/2011] [Indexed: 12/20/2022]
Abstract
Sphingosine-1-phosphate (S1P) is a bioactive lipid with diverse functions including the promotion of cell survival, proliferation and migration, as well as the regulation of angiogenesis, inflammation, immunity, vascular permeability and nuclear mechanisms that control gene transcription. S1P is derived from metabolism of ceramide, which itself has diverse and generally growth-inhibitory effects through its impact on downstream targets involved in regulation of apoptosis, senescence and cell cycle progression. Regulation of ceramide, S1P and the biochemical steps that modulate the balance and interconversion of these two lipids are major determinants of cell fate, a concept referred to as the "sphingolipid rheostat." There is abundant evidence that the sphingolipid rheostat plays a role in the origination, progression and drug resistance patterns of hematopoietic malignancies. The pathway has also been exploited to circumvent the problem of chemotherapy resistance in leukemia and lymphoma. Given the broad effects of sphingolipids, targeting multiple steps in the metabolic pathway may provide possible therapeutic avenues. However, new observations have revealed that sphingolipid signaling effects are more complex than previously recognized, requiring a revision of the sphingolipid rheostat model. Here, we summarize recent insights regarding the sphingolipid metabolic pathway and its role in hematopoietic malignancies.
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Affiliation(s)
- Kenneth C Loh
- Children's Hospital Oakland Research Institute, Center for Cancer Research, CA 94609, USA
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20
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Mendonca MS, Chin-Sinex H, Dhaemers R, Mead LE, Yoder MC, Ingram DA. Differential mechanisms of x-ray-induced cell death in human endothelial progenitor cells isolated from cord blood and adults. Radiat Res 2011; 176:208-16. [PMID: 21663393 DOI: 10.1667/rr2427.1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Endothelial colony-forming cells (ECFCs) are endothelial progenitor cells that circulate at low concentration in human umbilical cord and adult peripheral blood and are largely resident in blood vessels. ECFCs not only appear to be critical for normal vascular homeostasis and repair but may also contribute to tumor angiogenesis and response to therapy. To begin to characterize the potential role of ECFCs during the treatment of tumors in children and adults with radiation, we characterized the X-ray sensitivity of cord and adult blood-derived ECFCs. We found both cord blood and adult ECFCs to be highly radiation sensitive (3 Gy resulted in >90% killing without induction of apoptosis). The X-ray survival curves suggested reduced potential for repair capacity, but X-ray fractionation studies demonstrated that all the ECFCs exhibited repair when the radiation was fractionated. Finally, the mechanisms of X-ray-induced cell death for cord blood and adult ECFCs were different at low and high dose. At low dose, all ECFCs appear to die by mitotic death/catastrophe. However, at high radiation doses (≥ 10 Gy) cord blood ECFCs underwent p53 stabilization and Bax-dependent apoptosis as well as p21-dependent G₁ and G₂/M cell cycle checkpoints. By contrast, after 10 Gy adult ECFCs undergo only large-scale radiation-induced senescence, which is a cellular phenotype linked to premature development of atherosclerosis and vasculopathies. These data demonstrate that the ECFC response to radiation is dose-dependent and developmentally regulated and may provide potential mechanistic insight into their role in tumor and normal tissue response after ionizing radiation treatment.
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Affiliation(s)
- Marc S Mendonca
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
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21
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Heffernan-Stroud LA, Obeid LM. p53 and regulation of bioactive sphingolipids. ACTA ACUST UNITED AC 2010; 51:219-28. [PMID: 21035490 DOI: 10.1016/j.advenzreg.2010.10.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 10/14/2010] [Indexed: 12/19/2022]
Abstract
Both the sphingolipid and p53 pathways are important regulators- and apparent collaborators-of cell-fate decisions. Whereas some investigations have suggested that ceramide and more complex sphingolipids function upstream of p53 or in a p53-independent manner, other studies propose that p53-dependent alterations in these sphingolipids can also contribute to apoptosis. Further studies focusing on sphingolipid metabolizing enzymes have revealed that they function similarly both upstream and downstream of p53 activation. However, whereas various components of the sphingolipid and p53 pathways may simultaneously function to elicit apoptosis and/or growth inhibition, SMase and SK1 may undergo explicit regulation by p53 that could contribute to ceramide-induced senescence in cells. Thus, we propose that regulation of bioactive sphingolipid signaling molecules could be of therapeutic benefit in the treatment of p53-dependent cancers.
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22
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García-Barros M, Thin TH, Maj J, Cordon-Cardo C, Haimovitz-Friedman A, Fuks Z, Kolesnick R. Impact of stromal sensitivity on radiation response of tumors implanted in SCID hosts revisited. Cancer Res 2010; 70:8179-86. [PMID: 20924105 PMCID: PMC2976483 DOI: 10.1158/0008-5472.can-10-1871] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Severe combined immunodeficient (SCID) mice carry a germ-line mutation in DNA-PK, associated with deficiency in recognition and repair DNA double-strand breaks. Thus, SCID cells and tissues display increased sensitivity to radiation-induced postmitotic (clonogenic) cell death. Nonetheless, the single-radiation doses required for 50% permanent local control (TCD(50)) of tumors implanted in SCID mice are not significantly different from the TCD(50) values of the same tumors in wild-type hosts. Whereas the tumor stroma is derived from the host, the observation that tumors implanted in SCID mice do not exhibit hypersensitivity to radiation might imply that stromal endothelial elements do not contribute substantially to tumor cure by ionizing radiation. Here, we challenge this notion, testing the hypothesis that ASMase-mediated endothelial apoptosis, which results from plasma membrane alterations, not DNA damage, is a crucial element in the cure of tumors in SCID mice by single-dose radiotherapy (SDRT). We show that the endothelium in MCA/129 fibrosarcomas and B16 melanomas exhibits a wild-type apoptotic phenotype in SCID hosts, abrogated in tumors in SCID(asmase-/-) littermates, which also acquire resistance to SDRT. Conversion into a radioresistant tumor phenotype when implanted in SCID(asmase-/-) hosts provides compelling evidence that cell membrane ASMase-mediated microvascular dysfunction, rather than DNA damage-mediated endothelial clonogenic lethality, plays a mandatory role in the complex pathophysiologic mechanism of tumor cure by SDRT, and provides an explanation for the wild-type SDRT responses reported in tumors implanted in SCID mice.
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Affiliation(s)
- Mónica García-Barros
- Laboratory of Signal Transduction, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065
| | - Tin Htwe Thin
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065
| | - Jerzy Maj
- Department of Oncology and Radiation Therapy Cancer Center, University of Warmia and Mazury, Al., Wojska Polskiego 37, 10–228 Olsztyn, Poland
| | - Carlos Cordon-Cardo
- Department of Pathology, Columbia, University, 1130 St. Nicholas Ave. Room 309, New York, NY 10032
| | - Adriana Haimovitz-Friedman
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065
| | - Zvi Fuks
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065
| | - Richard Kolesnick
- Laboratory of Signal Transduction, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065
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