1
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Fu J, Ling J, Li CF, Tsai CL, Yin W, Hou J, Chen P, Cao Y, Kang Y, Sun Y, Xia X, Jiang Z, Furukawa K, Lu Y, Wu M, Huang Q, Yao J, Hawke DH, Pan BF, Zhao J, Huang J, Wang H, Bahassi EIM, Stambrook PJ, Huang P, Fleming JB, Maitra A, Tainer JA, Hung MC, Lin C, Chiao PJ. Nardilysin-regulated scission mechanism activates polo-like kinase 3 to suppress the development of pancreatic cancer. Nat Commun 2024; 15:3149. [PMID: 38605037 PMCID: PMC11009390 DOI: 10.1038/s41467-024-47242-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 03/25/2024] [Indexed: 04/13/2024] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) develops through step-wise genetic and molecular alterations including Kras mutation and inactivation of various apoptotic pathways. Here, we find that development of apoptotic resistance and metastasis of KrasG12D-driven PDAC in mice is accelerated by deleting Plk3, explaining the often-reduced Plk3 expression in human PDAC. Importantly, a 41-kDa Plk3 (p41Plk3) that contains the entire kinase domain at the N-terminus (1-353 aa) is activated by scission of the precursor p72Plk3 at Arg354 by metalloendopeptidase nardilysin (NRDC), and the resulting p32Plk3 C-terminal Polo-box domain (PBD) is removed by proteasome degradation, preventing the inhibition of p41Plk3 by PBD. We find that p41Plk3 is the activated form of Plk3 that regulates a feed-forward mechanism to promote apoptosis and suppress PDAC and metastasis. p41Plk3 phosphorylates c-Fos on Thr164, which in turn induces expression of Plk3 and pro-apoptotic genes. These findings uncover an NRDC-regulated post-translational mechanism that activates Plk3, establishing a prototypic regulation by scission mechanism.
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Affiliation(s)
- Jie Fu
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
| | - Jianhua Ling
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Ching-Fei Li
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Chi-Lin Tsai
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Wenjuan Yin
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Junwei Hou
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Ping Chen
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Yu Cao
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Ya'an Kang
- Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Yichen Sun
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Xianghou Xia
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Zhou Jiang
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Kenei Furukawa
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Yu Lu
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Min Wu
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Qian Huang
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Jun Yao
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - David H Hawke
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Bih-Fang Pan
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Jun Zhao
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Jiaxing Huang
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Huamin Wang
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
- Cancer Biology Program, The University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - E I Mustapha Bahassi
- Department of Molecular Genetics, University of Cincinnati Cancer Institute, Cincinnati, OH, 45267, USA
| | - Peter J Stambrook
- Department of Molecular Genetics, University of Cincinnati Cancer Institute, Cincinnati, OH, 45267, USA
| | - Peng Huang
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China
| | - Jason B Fleming
- Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
- Department of Gastrointestinal Oncology, Moffitt Cancer Center, Tampa, FL, 33612, USA
| | - Anirban Maitra
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
- Cancer Biology Program, The University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - John A Tainer
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Mien-Chie Hung
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
- Graduate Institute of Biomedical Sciences, Institute of Biochemistry and Molecular Biology, Research Center for Cancer Biology, Cancer Biology and Precision Therapeutics Center, and Center for Molecular Medicine, China Medical University, Taichung, 406, Taiwan
| | - Chunru Lin
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
- Cancer Biology Program, The University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.
| | - Paul J Chiao
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
- Cancer Biology Program, The University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.
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Kraljević Pavelić S, Micek V, Bobinac D, Bazdulj E, Gianoncelli A, Krpan D, Žuvić M, Eisenwagen S, Stambrook PJ, Pavelić K. Treatment of osteoporosis with a modified zeolite shows beneficial effects in an osteoporotic rat model and a human clinical trial. Exp Biol Med (Maywood) 2021; 246:529-537. [PMID: 33183068 PMCID: PMC7930600 DOI: 10.1177/1535370220968752] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 10/02/2020] [Indexed: 12/22/2022] Open
Abstract
The severity of osteoporosis in humans manifests in its high incidence and by its complications that diminish quality of life. A societal consequence of osteoporosis is the substantial burden that it inflicts upon patients and their families. Several bone-modifying drugs have been prescribed to patients with osteoporosis. However, evidence for their anti-fracture efficacy remains inconclusive. To the contrary, long-term use of anti-osteoporotic drugs such as bisphosphonates and Denosumab, an RANKL inhibitor, have resulted in adverse events. We now present an alternative and adjuvant approach for treatment of osteoporosis. The data derive from in vivo studies in an ovariectomized rat model and from a randomized double blind, placebo-controlled human clinical study. Both studies involved treatment with Panaceo Micro Activation (PMA)-zeolite-clinoptilolite, a defined cation exchange clinoptilolite, which clearly improved all bone histomorphometric parameters examined from ovariectomized animals, indicative for increased bone formation. Moreover, intervention with PMA-zeolite-clinoptilolite for one year proved safe in humans. Furthermore, patients treated with PMA-zeolite-clinoptilolite showed an increase in bone mineral density, an elevated level of markers indicative of bone formation, a significant reduction in pain, and significantly improved quality of life compared with patients in the control (placebo) group. These encouraging positive effects of PMA-zeolite-clinoptilolite on bone integrity and on osteoporosis warrant further evaluation of treatment with PMA-zeolite-clinoptilolite as a new alternative adjuvant therapy for osteoporosis.
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Affiliation(s)
| | - Vedran Micek
- Institute for Medical Research and Occupational Health, 10001 Zagreb, Croatia
| | - Dragica Bobinac
- Department of Anatomy, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia
- Clinic for Surgery, Clinical Hospital Rijeka, 51000 Rijeka, Croatia
- Faculty of Medicine, Juraj Dobrila University of Pula, 52100 Pula, Croatia
| | - Edo Bazdulj
- Department of Anatomy, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia
- Clinic for Surgery, Clinical Hospital Rijeka, 51000 Rijeka, Croatia
| | | | - Dalibor Krpan
- Polyclinic “K – Center,” for Internal Medicine, Gynecology, Radiology, Physical Medicine and Rehabilitation, 10 000 Zagreb, Croatia
| | - Marta Žuvić
- Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia
| | | | - Peter J Stambrook
- College of Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Krešimir Pavelić
- Faculty of Medicine, Juraj Dobrila University of Pula, 52100 Pula, Croatia
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3
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Che L, Alavattam KG, Stambrook PJ, Namekawa SH, Du C. BRUCE preserves genomic stability in the male germline of mice. Cell Death Differ 2020; 27:2402-2416. [PMID: 32139899 DOI: 10.1038/s41418-020-0513-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 01/30/2020] [Accepted: 01/31/2020] [Indexed: 01/01/2023] Open
Abstract
BRUCE is a DNA damage response protein that promotes the activation of ATM and ATR for homologous recombination (HR) repair in somatic cells, making BRUCE a key protector of genomic stability. Preservation of genomic stability in the germline is essential for the maintenance of species. Here, we show that BRUCE is required for the preservation of genomic stability in the male germline of mice, specifically in spermatogonia and spermatocytes. Conditional knockout of Bruce in the male germline leads to profound defects in spermatogenesis, including impaired maintenance of spermatogonia and increased chromosomal anomalies during meiosis. Bruce-deficient pachytene spermatocytes frequently displayed persistent DNA breaks. Homologous synapsis was impaired, and nonhomologous associations and rearrangements were apparent in up to 10% of Bruce-deficient spermatocytes. Genomic instability was apparent in the form of chromosomal fragmentation, translocations, and synapsed quadrivalents and hexavalents. In addition, unsynapsed regions of rearranged autosomes were devoid of ATM and ATR signaling, suggesting an impairment in the ATM- and ATR-dependent DNA damage response of meiotic HR. Taken together, our study unveils crucial functions for BRUCE in the maintenance of spermatogonia and in the regulation of meiotic HR-functions that preserve the genomic stability of the male germline.
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Affiliation(s)
- Lixiao Che
- Department of Cell and Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Kris G Alavattam
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Peter J Stambrook
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Satoshi H Namekawa
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Chunying Du
- Department of Cell and Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
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4
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Huang W, Liang J, Feng Y, Jia Z, Jiang L, Cai W, Paul C, Gu JG, Stambrook PJ, Millard RW, Zhu XL, Zhu P, Wang Y. Heterogeneity of adult masseter muscle satellite cells with cardiomyocyte differentiation potential. Exp Cell Res 2018; 371:20-30. [PMID: 29842877 PMCID: PMC7291879 DOI: 10.1016/j.yexcr.2018.05.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 05/21/2018] [Accepted: 05/24/2018] [Indexed: 01/25/2023]
Abstract
Although resident cardiac stem cells have been reported, regeneration of functional cardiomyocytes (CMs) remains a challenge. The present study identifies an alternative progenitor source for CM regeneration without the need for genetic manipulation or invasive heart biopsy procedures. Unlike limb skeletal muscles, masseter muscles (MM) in the mouse head are developed from Nkx2-5 mesodermal progenitors. Adult masseter muscle satellite cells (MMSCs) display heterogeneity in developmental origin and cell phenotypes. The heterogeneous MMSCs that can be characterized by cell sorting based on stem cell antigen-1 (Sca1) show different lineage potential. While cardiogenic potential is preserved in Sca1+ MMSCs as shown by expression of cardiac progenitor genes (including Nkx2-5), skeletal myogenic capacity is maintained in Sca1- MMSCs with Pax7 expression. Sca1+ MMSC-derived beating cells express cardiac genes and exhibit CM-like morphology. Electrophysiological properties of MMSC-derived CMs are demonstrated by calcium transients and action potentials. These findings show that MMSCs could serve as a novel cell source for cardiomyocyte replacement.
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Affiliation(s)
- Wei Huang
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Jialiang Liang
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Yuliang Feng
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Zhanfeng Jia
- Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Lin Jiang
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Wenfeng Cai
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Christian Paul
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Jianguo G Gu
- Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Peter J Stambrook
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Ronald W Millard
- Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Xiao-Lan Zhu
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Ping Zhu
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China.
| | - Yigang Wang
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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5
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Huang W, Feng Y, Liang J, Yu H, Wang C, Wang B, Wang M, Jiang L, Meng W, Cai W, Medvedovic M, Chen J, Paul C, Davidson WS, Sadayappan S, Stambrook PJ, Yu XY, Wang Y. Loss of microRNA-128 promotes cardiomyocyte proliferation and heart regeneration. Nat Commun 2018; 9:700. [PMID: 29453456 PMCID: PMC5816015 DOI: 10.1038/s41467-018-03019-z] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 01/12/2018] [Indexed: 12/20/2022] Open
Abstract
The goal of replenishing the cardiomyocyte (CM) population using regenerative therapies following myocardial infarction (MI) is hampered by the limited regeneration capacity of adult CMs, partially due to their withdrawal from the cell cycle. Here, we show that microRNA-128 (miR-128) is upregulated in CMs during the postnatal switch from proliferation to terminal differentiation. In neonatal mice, cardiac-specific overexpression of miR-128 impairs CM proliferation and cardiac function, while miR-128 deletion extends proliferation of postnatal CMs by enhancing expression of the chromatin modifier SUZ12, which suppresses p27 (cyclin-dependent kinase inhibitor) expression and activates the positive cell cycle regulators Cyclin E and CDK2. Furthermore, deletion of miR-128 promotes cell cycle re-entry of adult CMs, thereby reducing the levels of fibrosis, and attenuating cardiac dysfunction in response to MI. These results suggest that miR-128 serves as a critical regulator of endogenous CM proliferation, and might be a novel therapeutic target for heart repair. During early postnatal development in mammals, cardiomyocytes exit the cell cycle, losing their regenerative capacity. Here the authors show that, following myocardial infarction, loss of microRNA-128 promotes cardiomyocyte proliferation and cardiac regeneration in adult mice partly via enhancing the expression of the chromatin modifier SUZ12.
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Affiliation(s)
- Wei Huang
- Key Laboratory of Molecular Target and Clinical Pharmacology, School of Pharmaceutical Sciences & Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, 511436, China.,Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Yuliang Feng
- Key Laboratory of Molecular Target and Clinical Pharmacology, School of Pharmaceutical Sciences & Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, 511436, China
| | - Jialiang Liang
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Hao Yu
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Cheng Wang
- Department of Molecular Biology, Radboud Institute of Molecular Life Sciences and Faculty of Science, Radboud University, Nijmegen, 6525, Gelderland, The Netherlands
| | - Boyu Wang
- Samaritan Medical Center, 830 Washington Street, Watertown, NY, 13601, USA
| | - Mingyang Wang
- College of Engineering and Applied Science, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Lin Jiang
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Wei Meng
- Division of Liver Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, 510630, China
| | - Wenfeng Cai
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Mario Medvedovic
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Jenny Chen
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Christian Paul
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - W Sean Davidson
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Sakthivel Sadayappan
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Peter J Stambrook
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Xi-Yong Yu
- Key Laboratory of Molecular Target and Clinical Pharmacology, School of Pharmaceutical Sciences & Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, 511436, China.
| | - Yigang Wang
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
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6
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Lozada EM, Andrysik Z, Yin M, Redilla N, Rice K, Stambrook PJ. Acetylation and deacetylation of Cdc25A constitutes a novel mechanism for modulating Cdc25A functions with implications for cancer. Oncotarget 2018; 7:20425-39. [PMID: 26967250 PMCID: PMC4991465 DOI: 10.18632/oncotarget.7966] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 02/16/2016] [Indexed: 11/25/2022] Open
Abstract
The dual specificity phosphatase Cdc25A is a key regulator of the cell cycle that promotes cell cycle progression by dephosphorylating and activating cyclin-dependent kinases. In response to genotoxicants, Cdc25A undergoes posttranslational modifications which contribute to its proteasome-mediated degradation and consequent cell cycle checkpoint arrest. The most thoroughly studied Cdc25A modification is phosphorylation. We now provide the first evidence that Cdc25A can be acetylated and that it directly interacts with the ARD1 acetyltransferase which acetylates Cdc25A both biochemically and in cultured cells. When acetylated, Cdc25A has an extended half-life. We have also identified the class IV histone deacetylase, HDAC11, as a Cdc25A deacetylase. We further show that DNA damage, such as exposure to methyl methanesulfonate (MMS), etoposide or arsenic, increases Cdc25A acetylation. Importantly, this acetylation modulates Cdc25A phosphatase activity and its function as a cell cycle regulator, and may reflect a cellular response to DNA damage. Since Cdc25A, ARD1, and HDAC11 are frequently dysregulated in multiple types of cancer, our findings may provide insight into a novel mechanism in carcinogenesis.
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Affiliation(s)
- Enerlyn M Lozada
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA
| | - Zdenek Andrysik
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA.,Current affiliation: Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Moying Yin
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA
| | - Nicholas Redilla
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA
| | - Kathryn Rice
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA
| | - Peter J Stambrook
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA
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7
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Stambrook PJ, Maher J, Farzaneh F. Cancer Immunotherapy: Whence and Whither. Mol Cancer Res 2017; 15:635-650. [PMID: 28356330 DOI: 10.1158/1541-7786.mcr-16-0427] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 12/22/2016] [Accepted: 01/14/2017] [Indexed: 12/22/2022]
Abstract
The current concepts and practice of cancer immunotherapy evolved from classical experiments that distinguished "self" from "non-self" and the finding that humoral immunity is complemented by cellular immunity. Elucidation of the biology underlying immune checkpoints and interactions between ligands and ligand receptors that govern the immune system's ability to recognize tumor cells as foreign has led to the emergence of new strategies that mobilize the immune system to reverse this apparent tolerance. Some of these approaches have led to new therapies such as the use of mAbs to interfere with the immune checkpoint. Others have exploited molecular technologies to reengineer a subset of T cells to directly engage and kill tumor cells, particularly those of B-cell malignancies. However, before immunotherapy can become a more effective method of cancer care, there are many challenges that remain to be addressed and hurdles to overcome. Included are manipulation of tumor microenvironment (TME) to enhance T effector cell infiltration and access to the tumor, augmentation of tumor MHC expression for adequate presentation of tumor associated antigens, regulation of cytokines and their potential adverse effects, and reduced risk of secondary malignancies as a consequence of mutations generated by the various forms of genetic engineering of immune cells. Despite these challenges, the future of immunotherapy as a standard anticancer therapy is encouraging. Mol Cancer Res; 15(6); 635-50. ©2017 AACR.
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Affiliation(s)
- Peter J Stambrook
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio.
| | - John Maher
- Kings College London, CAR Mechanics Group, Guy's Hospital, London, United Kingdom
| | - Farzin Farzaneh
- Division of Cancer Studies, Department of Haematological Medicine, Kings College London, London, United Kingdom
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8
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Michel DR, Mun KS, Ho CC, Stambrook PJ. Cytoskeletal architecture and cell motility remain unperturbed in mouse embryonic fibroblasts from Plk3 knockout mice. Exp Biol Med (Maywood) 2016; 241:603-10. [PMID: 26843517 DOI: 10.1177/1535370216629010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 01/04/2016] [Indexed: 11/17/2022] Open
Abstract
Polo-like kinase 3 (Plk3) is best known for its involvement in cell cycle checkpoint regulation following exposure to cytotoxicants or induction of DNA damage. Yet, Plk3 has also been implicated in roles beyond those of cellular responses to DNA damage. Here, we have investigated the proposition, suggested by the Plk literature, that Plk3 regulates cytoskeletal architecture and cell functions mediated by the cytoskeleton. To this end, we have assayed mouse embryonic fibroblasts (MEFs) generated from both Plk3 knockout and wild-type mice. In particular, we asked whether Plk3 is involved in actin fiber and microtubule integrity, cell migration, cell attachment, and/or cell invasion. Our results demonstrate that functional Plk3 is not critical for the regulation of cytoskeletal integrity, cell morphology, cell adhesion, or motility in MEFs.
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Affiliation(s)
- Daniel R Michel
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Kyu-Shik Mun
- Department of Chemical and Materials Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Chia-Chi Ho
- Department of Chemical and Materials Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Peter J Stambrook
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA
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9
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Li S, Li B, Cheng C, Xiong Z, Liu Q, Lai J, Carey HV, Zhang Q, Zheng H, Wei S, Zhang H, Chang L, Liu S, Zhang S, Yu B, Zeng X, Hou Y, Nie W, Guo Y, Chen T, Han J, Wang J, Wang J, Chen C, Liu J, Stambrook PJ, Xu M, Zhang G, Gilbert MTP, Yang H, Jarvis ED, Yu J, Yan J. Genomic signatures of near-extinction and rebirth of the crested ibis and other endangered bird species. Genome Biol 2015; 15:557. [PMID: 25496777 PMCID: PMC4290368 DOI: 10.1186/s13059-014-0557-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Indexed: 01/19/2023] Open
Abstract
Background Nearly one-quarter of all avian species is either threatened or nearly threatened. Of these, 73 species are currently being rescued from going extinct in wildlife sanctuaries. One of the previously most critically-endangered is the crested ibis, Nipponia nippon. Once widespread across North-East Asia, by 1981 only seven individuals from two breeding pairs remained in the wild. The recovering crested ibis populations thus provide an excellent example for conservation genomics since every individual bird has been recruited for genomic and demographic studies. Results Using high-quality genome sequences of multiple crested ibis individuals, its thriving co-habitant, the little egret, Egretta garzetta, and the recently sequenced genomes of 41 other avian species that are under various degrees of survival threats, including the bald eagle, we carry out comparative analyses for genomic signatures of near extinction events in association with environmental and behavioral attributes of species. We confirm that both loss of genetic diversity and enrichment of deleterious mutations of protein-coding genes contribute to the major genetic defects of the endangered species. We further identify that genetic inbreeding and loss-of-function genes in the crested ibis may all constitute genetic susceptibility to other factors including long-term climate change, over-hunting, and agrochemical overuse. We also establish a genome-wide DNA identification platform for molecular breeding and conservation practices, to facilitate sustainable recovery of endangered species. Conclusions These findings demonstrate common genomic signatures of population decline across avian species and pave a way for further effort in saving endangered species and enhancing conservation genomic efforts. Electronic supplementary material The online version of this article (doi:10.1186/s13059-014-0557-1) contains supplementary material, which is available to authorized users.
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Mamrosh JL, Lee JM, Wagner M, Stambrook PJ, Whitby RJ, Sifers RN, Wu SP, Tsai MJ, DeMayo FJ, Moore DD. Correction: Nuclear receptor LRH-1/NR5A2 is required and targetable for liver endoplasmic reticulum stress resolution. eLife 2015. [PMID: 26205891 PMCID: PMC4512255 DOI: 10.7554/elife.10084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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11
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Abstract
Demand for new technologies that deliver fast, inexpensive and accurate genome information has never been greater. This challenge has catalysed the rapid development of advances in next-generation sequencing (NGS). The generation of large volumes of sequence data and the speed of data acquisition are the primary advantages over previous, more standard methods. In 2013, the Food and Drug Administration granted marketing authorisation for the first high-throughput NG sequencer, Illumina's MiSeqDx, which allowed the development and use of a large number of new genome-based tests. Here, we present a review of template preparation, nucleic acid sequencing and imaging, genome assembly and alignment approaches as well as recent advances in current and near-term commercially available NGS instruments. We also outline the broad range of applications for NGS technologies and provide guidelines for platform selection to best address biological questions of interest. DNA sequencing has revolutionised biological and medical research, and is poised to have a similar impact on the practice of medicine. This tool is but one of an increasing arsenal of developing tools that enhance our capabilities to identify, quantify and functionally characterise the components of biological networks that keep us healthy or make us sick. Despite advances in other 'omic' technologies, DNA sequencing and analysis, in many respects, have played the leading role to date. The new technologies provide a bridge between genotype and phenotype, both in man and model organisms, and have revolutionised how risk of developing a complex human disease may be assessed. The generation of large DNA sequence data sets is producing a wealth of medically relevant information on a large number of individuals and populations that will potentially form the basis of truly individualised medical care in the future.
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Affiliation(s)
- El Mustapha Bahassi
- Department of Internal Medicine, Division of Hematology/Oncology, UC Brain Tumor Center, University of Cincinnati, 3125 Eden Avenue, Cincinnati, OH 45267-0508, USA, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, 3125 Eden Avenue, Cincinnati, OH 45267-0508, USA
| | - Peter J Stambrook
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, 3125 Eden Avenue, Cincinnati, OH 45267-0508, USA
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12
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Furgason JM, Li W, Milholland B, Cross E, Li Y, McPherson CM, Warnick RE, Rixe O, Stambrook PJ, Vijg J, Bahassi EM. Whole genome sequencing of glioblastoma multiforme identifies multiple structural variations involved in EGFR activation. Mutagenesis 2014; 29:341-50. [PMID: 25103728 DOI: 10.1093/mutage/geu026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Next generation sequencing has become a powerful tool in dissecting and identifying mutations and genomic structural variants that accompany tumourigenesis. Sequence analysis of glioblastoma multiforme (GBM) illustrates the ability to rapidly identify mutations that may affect phenotype. Approximately 50% of human GBMs overexpress epidermal growth factor receptor (EGFR) which renders the EGFR protein a compelling therapeutic target. In brain tumours, attempts to target EGFR as a cancer therapeutic, however, have achieved little or no benefit. The mechanisms that drive therapeutic resistance to EGFR inhibitors in brain tumours are not well defined, and drug resistance contributes to the deadly and aggressive nature of the disease. Whole genome sequencing of four primary GBMs revealed multiple pathways by which EGFR protein abundance becomes deregulated in these tumours and will guide the development of new strategies for treating EGFR overexpressing tumours. Each of the four tumours displayed a different mechanism leading to increased EGFR protein levels. One mechanism is mediated by gene amplification and tandem duplication of the kinase domain. A second involves an intragenic deletion that generates a constitutively active form of the protein. A third combines the loss of a gene which encodes a protein that regulates EGFR abundance as well as an miRNA that modulates EGFR expression. A fourth mechanism entails loss of an ubiquitin ligase docking site in the C-terminal part of the protein whose absence inhibits turnover of the receptor.
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Affiliation(s)
- John M Furgason
- Department of Internal Medicine, Division of Hematology/Oncology, University of Cincinnati College of Medicine, 231, Albert Sabin Way, Cincinnati, OH, USA
| | - Wenge Li
- Albert Einstein Medical Center, 1301 Morris Park Avenue, New York, NY, USA
| | - Brandon Milholland
- Albert Einstein Medical Center, 1301 Morris Park Avenue, New York, NY, USA
| | - Emily Cross
- Department of Molecular Genetics, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, USA
| | - Yaqin Li
- Department of Molecular Genetics, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, USA
| | - Christopher M McPherson
- Department of Neurosurgery and UC Brain Tumor Center, University of Cincinnati, 234 Goodman Street, Cincinnati, OH, USA
| | - Ronald E Warnick
- Department of Neurosurgery and UC Brain Tumor Center, University of Cincinnati, 234 Goodman Street, Cincinnati, OH, USA
| | - Olivier Rixe
- GRU Cancer Center, 1411 Laney Walker Boulevard Augusta, GA, USA
| | - Peter J Stambrook
- Department of Molecular Genetics, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, USA
| | - Jan Vijg
- Albert Einstein Medical Center, 1301 Morris Park Avenue, New York, NY, USA
| | - El Mustapha Bahassi
- Department of Internal Medicine, Division of Hematology/Oncology, University of Cincinnati College of Medicine, 231, Albert Sabin Way, Cincinnati, OH, USA, UC Brain Tumor Center, University of Cincinnati, 234 Goodman Street, Cincinnati, OH, USA,
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13
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Mamrosh JL, Lee JM, Wagner M, Stambrook PJ, Whitby RJ, Sifers RN, Wu SP, Tsai MJ, Demayo FJ, Moore DD. Nuclear receptor LRH-1/NR5A2 is required and targetable for liver endoplasmic reticulum stress resolution. eLife 2014; 3:e01694. [PMID: 24737860 PMCID: PMC3987120 DOI: 10.7554/elife.01694] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Chronic endoplasmic reticulum (ER) stress results in toxicity that contributes to multiple human disorders. We report a stress resolution pathway initiated by the nuclear receptor LRH-1 that is independent of known unfolded protein response (UPR) pathways. Like mice lacking primary UPR components, hepatic Lrh-1-null mice cannot resolve ER stress, despite a functional UPR. In response to ER stress, LRH-1 induces expression of the kinase Plk3, which phosphorylates and activates the transcription factor ATF2. Plk3-null mice also cannot resolve ER stress, and restoring Plk3 expression in Lrh-1-null cells rescues ER stress resolution. Reduced or heightened ATF2 activity also sensitizes or desensitizes cells to ER stress, respectively. LRH-1 agonist treatment increases ER stress resistance and decreases cell death. We conclude that LRH-1 initiates a novel pathway of ER stress resolution that is independent of the UPR, yet equivalently required. Targeting LRH-1 may be beneficial in human disorders associated with chronic ER stress. DOI:http://dx.doi.org/10.7554/eLife.01694.001 A protein can only work properly if it has been folded into the correct shape. However, it is estimated that about one third of new proteins have the wrong shape. This is a major challenge for cells because misfolded proteins are often toxic, and cause many neurodegenerative and metabolic disorders. In eukaryotic cells, most protein folding takes place inside a part of the cell called the endoplasmic reticulum (ER). If an incorrectly folded protein is detected, it is prevented from leaving the ER until it is refolded correctly, or destroyed. If too many proteins are misfolded, a process called the unfolded protein response helps the cell to cope with this ‘ER stress’ by expanding the ER and producing more of the molecules that assist protein folding. If this does not relieve the ER stress, the cell self-destructs. Neighboring cells then have to increase protein production to compensate for what would have been produced by the dead cell, thereby increasing the chance that they will also experience ER stress. Activation of a protein called LRH-1 (short for liver receptor homolog-1) that is produced in the liver, pancreas and intestine can relieve the symptoms of the various metabolic diseases that are associated with chronic ER stress, including type II diabetes and fatty liver disease. However, researchers have been puzzled by the fact that although LRH-1 performs many different roles, its molecular structure provides few clues as to how it can do this. Mamrosh et al. now confirm the speculated link between LRH-1 and ER stress relief in mice. LRH-1 triggers a previously unknown pathway that can relieve ER stress and is completely independent of the unfolded protein response. Targeting LRH-1 with certain chemical compounds alters its activity, suggesting that drug treatments could be developed to relieve ER stress. As similar targets for drugs have not been found in the unfolded protein response, the discovery of the LRH-1 pathway could lead to new approaches to the treatment of the diseases that result from ER stress. DOI:http://dx.doi.org/10.7554/eLife.01694.002
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Affiliation(s)
- Jennifer L Mamrosh
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, United States
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14
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Stambrook PJ. Nuclear transfer between two species of Acetabularia. Exp Biol Med (Maywood) 2013; 238:257-8. [PMID: 23598970 DOI: 10.1177/1535370213482084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Peter J Stambrook
- Cell & Cancer Biology, University of Cincinnati Medical Center, Cincinnati, OH 45267, USA.
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15
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Tichy ED, Stephan ZA, Osterburg A, Noel G, Stambrook PJ. Mouse embryonic stem cells undergo charontosis, a novel programmed cell death pathway dependent upon cathepsins, p53, and EndoG, in response to etoposide treatment. Stem Cell Res 2013; 10:428-41. [PMID: 23500643 DOI: 10.1016/j.scr.2013.01.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 01/18/2013] [Accepted: 01/29/2013] [Indexed: 02/09/2023] Open
Abstract
Embryonic stem cells (ESCs) are hypersensitive to many DNA damaging agents and can rapidly undergo cell death or cell differentiation following exposure. Treatment of mouse ESCs (mESCs) with etoposide (ETO), a topoisomerase II poison, followed by a recovery period resulted in massive cell death with characteristics of a programmed cell death pathway (PCD). While cell death was both caspase- and necroptosis-independent, it was partially dependent on the activity of lysosomal proteases. A role for autophagy in the cell death process was eliminated, suggesting that ETO induces a novel PCD pathway in mESCs. Inhibition of p53 either as a transcription factor by pifithrin α or in its mitochondrial role by pifithrin μ significantly reduced ESC death levels. Finally, EndoG was newly identified as a protease participating in the DNA fragmentation observed during ETO-induced PCD. We coined the term charontosis after Charon, the ferryman of the dead in Greek mythology, to refer to the PCD signaling events induced by ETO in mESCs.
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Affiliation(s)
- Elisia D Tichy
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
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16
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Tichy ED, Pillai R, Deng L, Tischfield JA, Hexley P, Babcock GF, Stambrook PJ. The abundance of Rad51 protein in mouse embryonic stem cells is regulated at multiple levels. Stem Cell Res 2012; 9:124-34. [PMID: 22705496 DOI: 10.1016/j.scr.2012.05.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Revised: 05/10/2012] [Accepted: 05/11/2012] [Indexed: 11/30/2022] Open
Abstract
DNA double-strand breaks (DSBs) in embryonic stem (ES) cells are repaired primarily by homologous recombination (HR). The mechanism by which HR is regulated in these cells, however, remains enigmatic. To gain insight into such regulatory mechanisms, we have asked how protein levels of Rad51, a key component of HR, are controlled in mouse ES cells and mouse embryo fibroblasts (MEFs). The Rad51 protein level is about 15-fold higher in ES cells than in MEFs. The level of Rad51 mRNA, however, is only ~2-fold higher, indicating that the differences in mRNA levels due to rates of transcription or mRNA stability are not sufficient to account for the large difference in the abundance of Rad51 protein. Comparison of Rad51 half-lives between ES cells and MEFs also did not explain the elevated level of Rad51 protein in the ES cells. A comparative assessment of the Rad51 translation level demonstrated that it is translated with much greater efficacy in ES cells than in MEFs. To determine whether this high level of translation in ES cells is a general phenomenon in these cells or whether it is a characteristic of specific proteins, such as those involved with recombination and cell cycle progression, we compared mechanisms that regulate the level of Pcna in ES cells with those that regulate Rad51. The half-life of Pcna and its rate of synthesis were considerably different from those of Rad51 in ES cells, demonstrating that regulation of Rad51 abundance cannot be generalized to other ES cell proteins and not to proteins involved in DNA replication and cell cycle control. Finally, we show that only a small proportion of the abundant Rad51 protein population is activated under basal conditions in ES cells and recruited to DNA DSBs and/or stalled replication forks.
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Affiliation(s)
- Elisia D Tichy
- Department of Molecular Genetics, University of Cincinnati, College of Medicine, Cincinnati OH 45267, USA.
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17
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Kavanaugh GM, Wise-Draper TM, Morreale RJ, Morrison MA, Gole B, Schwemberger S, Tichy ED, Lu L, Babcock GF, Wells JM, Drissi R, Bissler JJ, Stambrook PJ, Andreassen PR, Wiesmüller L, Wells SI. The human DEK oncogene regulates DNA damage response signaling and repair. Nucleic Acids Res 2011; 39:7465-76. [PMID: 21653549 PMCID: PMC3177200 DOI: 10.1093/nar/gkr454] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 05/16/2011] [Indexed: 12/04/2022] Open
Abstract
The human DEK gene is frequently overexpressed and sometimes amplified in human cancer. Consistent with oncogenic functions, Dek knockout mice are partially resistant to chemically induced papilloma formation. Additionally, DEK knockdown in vitro sensitizes cancer cells to DNA damaging agents and induces cell death via p53-dependent and -independent mechanisms. Here we report that DEK is important for DNA double-strand break repair. DEK depletion in human cancer cell lines and xenografts was sufficient to induce a DNA damage response as assessed by detection of γH2AX and FANCD2. Phosphorylation of H2AX was accompanied by contrasting activation and suppression, respectively, of the ATM and DNA-PK pathways. Similar DNA damage responses were observed in primary Dek knockout mouse embryonic fibroblasts (MEFs), along with increased levels of DNA damage and exaggerated induction of senescence in response to genotoxic stress. Importantly, Dek knockout MEFs exhibited distinct defects in non-homologous end joining (NHEJ) when compared to their wild-type counterparts. Taken together, the data demonstrate new molecular links between DEK and DNA damage response signaling pathways, and suggest that DEK contributes to DNA repair.
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Affiliation(s)
- Gina M. Kavanaugh
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Trisha M. Wise-Draper
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Richard J. Morreale
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Monique A. Morrison
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Boris Gole
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Sandy Schwemberger
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Elisia D. Tichy
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Lu Lu
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - George F. Babcock
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - James M. Wells
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Rachid Drissi
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - John J. Bissler
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Peter J. Stambrook
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Paul R. Andreassen
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Lisa Wiesmüller
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Susanne I. Wells
- Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA Division of Gynecological Oncology, Department of Gynecology and Obstetrics, Ulm University, D-89075 Ulm, Germany, Research, Shriners Hospitals for Children, Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Department of Surgery, University of Cincinnati College of Medicine, Division of Molecular and Developmental Biology, Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
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Denissova NG, Tereshchenko IV, Cui E, Stambrook PJ, Shao C, Tischfield JA. Ionizing radiation is a potent inducer of mitotic recombination in mouse embryonic stem cells. Mutat Res 2011; 715:1-6. [PMID: 21802432 DOI: 10.1016/j.mrfmmm.2011.06.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 05/30/2011] [Accepted: 06/29/2011] [Indexed: 12/28/2022]
Abstract
Maintenance of genomic integrity in embryonic cells is pivotal to proper embryogenesis, organogenesis and to the continuity of species. Cultured mouse embryonic stem cells (mESCs), a model for early embryonic cells, differ from cultured somatic cells in their capacity to remodel chromatin, in their repertoire of DNA repair enzymes, and in the regulation of cell cycle checkpoints. Using 129XC3HF1 mESCs heterozygous for Aprt, we characterized loss of Aprt heterozygosity after exposure to ionizing radiation. We report here that the frequency of loss of heterozygosity mutants in mESCs can be induced several hundred-fold by exposure to 5-10Gy of X-rays. This induction is 50-100-fold higher than the induction reported for mouse adult or embryonic fibroblasts. The primary mechanism underlying the elevated loss of heterozygosity after irradiation is mitotic recombination, with lesser contributions from deletions and gene conversions that span Aprt. Aprt point mutations and epigenetic inactivation are very rare in mESCs compared to fibroblasts. Mouse ESCs, therefore, are distinctive in their response to ionizing radiation and studies of differentiated cells may underestimate the mutagenic effects of ionizing radiation on ESC or other stem cells. Our findings are important to understanding the biological effects of ionizing radiation on early development and carcinogenesis.
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Affiliation(s)
- Natalia G Denissova
- Department of Genetics, Rutgers University, Piscataway, 145 Bevier Rd, NJ 08854, United States
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Dai B, Zhao XF, Mazan-Mamczarz K, Hagner P, Corl S, Bahassi EM, Lu S, Stambrook PJ, Shapiro P, Gartenhaus RB. Functional and molecular interactions between ERK and CHK2 in diffuse large B-cell lymphoma. Nat Commun 2011; 2:402. [PMID: 21772273 PMCID: PMC3144586 DOI: 10.1038/ncomms1404] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 06/20/2011] [Indexed: 01/02/2023] Open
Abstract
Distinct oncogenic signalling cascades have been associated with non-Hodgkin lymphoma. ERK1/2 signalling elicits both transcriptional and post-transcriptional effects through phosphorylation of numerous substrates. Here we report a novel molecular relationship between ERK1/2 and CHK2, a protein kinase that is a key mediator of the DNA damage checkpoint that responds to DNA double-strand breaks. Our studies are the first to demonstrate the co-localization and overexpression of ERK1/2 and CHK2 in diffuse large B-cell lymphoma (DLBCL). The physical interaction between ERK and CHK2 was highly dependent on phosphorylated Thr 68 of CHK2. Concurrent administration of an ERK inhibitor enhances the antitumour activity of CHK2 inhibition in both a human DLBCL xenograft model as well as primary human DLBCL cells. Our data suggest a functional interaction between ERK and CHK2 and support the potential combined therapeutic targeting of ERK and CHK2 in human DLBCL. Chk2 is a kinase that is a potential chemotherapeutic target. Here, Chk2 and the kinase ERK are shown to functionally interact, and are elevated in expression in human diffuse B-cell lymphomas. Combinatorial inhibition of the kinases was also shown to block tumour growth in an in vivo mouse model.
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Affiliation(s)
- Bojie Dai
- University of Maryland, Marlene & Stewart Greenebaum Cancer Center, Department of Medicine, Baltimore, Maryland 21201, USA
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20
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Myer DL, Robbins SB, Yin M, Boivin GP, Liu Y, Greis KD, Bahassi EM, Stambrook PJ. Absence of polo-like kinase 3 in mice stabilizes Cdc25A after DNA damage but is not sufficient to produce tumors. Mutat Res 2011; 714:1-10. [PMID: 21376736 DOI: 10.1016/j.mrfmmm.2011.02.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 01/05/2011] [Accepted: 02/15/2011] [Indexed: 11/29/2022]
Abstract
The polo-like kinases (Plks1-5) are emerging as an important class of proteins involved in many facets of cell cycle regulation and response to DNA damage and stress. Here we show that Plk3 phosphorylates the key cell cycle protein phosphatase Cdc25A on two serine residues in its cyclinB/cdk1 docking domain and regulates its stability in response to DNA damage. We generated a Plk3 knock-out mouse and show that Cdc25A protein from Plk3-deficient cells is less susceptible to DNA damage-mediated degradation than cells with functional Plk3. We also show that absence of Plk3 correlates with loss of the G1/S cell cycle checkpoint. However, neither this compromised DNA damage checkpoint nor reduced susceptibility to proteasome-mediated degradation after DNA damage translated into a significant increase in tumor incidence in the Plk3-deficient mice.
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Affiliation(s)
- David L Myer
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0524, USA
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21
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Tichy ED, Liang L, Deng L, Tischfield J, Schwemberger S, Babcock G, Stambrook PJ. Mismatch and base excision repair proficiency in murine embryonic stem cells. DNA Repair (Amst) 2011; 10:445-51. [PMID: 21315663 DOI: 10.1016/j.dnarep.2011.01.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 12/20/2010] [Accepted: 01/12/2011] [Indexed: 02/02/2023]
Abstract
Accumulation of mutations in embryonic stem (ES) cells would be detrimental to an embryo derived from these cells, and would adversely affect multiple organ systems and tissue types. ES cells have evolved multiple mechanisms to preserve genomic integrity that extend beyond those found in differentiated cell types. The present study queried whether mismatch repair (MMR) and base-excision repair (BER) may play a role in the maintenance of murine ES cell genomes. The MMR proteins Msh2 and Msh6 are highly elevated in mouse ES cells compared with mouse embryo fibroblasts (MEFs), as are Pms2 and Mlh1, albeit to a lesser extent. Cells transfected with an MMR reporter plasmid showed that MMR repair capacity is low in MEFs, but highly active in wildtype ES cells. As expected, an ES cell line defective in MMR was several-fold less effective in repair level than wildtype ES cells. Like proteins that participate in MMR, the level of proteins involved in BER was elevated in ES cells compared with MEFs. When BER activity was examined biochemically using a uracil-containing oligonucleotide template, repair activity was higher in ES cells compared with MEFs. The data are consistent with the suggestion that ES cells have multiple mechanisms, including highly active MMR and BER that preserve genetic integrity and minimize the accumulation of mutations.
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Affiliation(s)
- Elisia D Tichy
- Department of Molecular Genetics, Biochemistry & Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA.
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22
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Bahassi EM, Yin M, Robbins SB, Li YQ, Conrady DG, Yuan Z, Kovall RA, Herr AB, Stambrook PJ. A human cancer-predisposing polymorphism in Cdc25A is embryonic lethal in the mouse and promotes ASK-1 mediated apoptosis. Cell Div 2011; 6:4. [PMID: 21310058 PMCID: PMC3048473 DOI: 10.1186/1747-1028-6-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 02/10/2011] [Indexed: 11/24/2022] Open
Abstract
Background Failure to regulate the levels of Cdc25A phosphatase during the cell cycle or during a checkpoint response causes bypass of DNA damage and replication checkpoints resulting in genomic instability and cancer. During G1 and S and in cellular response to DNA damage, Cdc25A is targeted for degradation through the Skp1-cullin-β-TrCP (SCFβ-TrCP) complex. This complex binds to the Cdc25A DSG motif which contains serine residues at positions 82 and 88. Phosphorylation of one or both residues is necessary for the binding and degradation to occur. Results We now show that mutation of serine 88 to phenylalanine, which is a cancer-predisposing polymorphic variant in humans, leads to early embryonic lethality in mice. The mutant protein retains its phosphatase activity both in vitro and in cultured cells. It fails to interact with the apoptosis signal-regulating kinase 1 (ASK1), however, and therefore does not suppress ASK1-mediated apoptosis. Conclusions These data suggest that the DSG motif, in addition to its function in Cdc25A-mediated degradation, plays a role in cell survival during early embyogenesis through suppression of ASK1-mediated apoptosis.
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Affiliation(s)
- El Mustapha Bahassi
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA.
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23
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Meyer SE, Peace BE, Bahassi EM, Kavanaugh GM, Wagh PK, Robbins SB, Yin M, Wells SI, Zinser GM, Stambrook PJ, Waltz SE. Chk2*1100delC Acts in synergy with the Ron receptor tyrosine kinase to accelerate mammary tumorigenesis in mice. Cancer Lett 2010; 296:186-93. [PMID: 20434834 DOI: 10.1016/j.canlet.2010.04.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 03/31/2010] [Accepted: 04/06/2010] [Indexed: 01/01/2023]
Abstract
The CHEK2 (Chk2 in mice) polymorphic variant, CHEK2*1100delC, leads to genomic instability and is associated with an increased risk for breast cancer. The Ron receptor tyrosine kinase is overexpressed in a large fraction of human breast cancers. Here, we asked whether the low penetrance Chk2*1100delC allele alters the tumorigenic efficacy of Ron in the development of mammary tumors in a mouse model. Our data demonstrate that Ron overexpression on a Chk2*1100delC background accelerates the development of mammary tumors, and shows that pathways mediated by a tyrosine kinase receptor and a regulator of the cell cycle can act to hasten tumorigenesis in vivo.
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Affiliation(s)
- Sara E Meyer
- Department of Cancer and Cell Biology, University of Cincinnati College of Medicine, OH 45267, USA
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Tichy ED, Pillai R, Deng L, Liang L, Tischfield J, Schwemberger SJ, Babcock GF, Stambrook PJ. Mouse embryonic stem cells, but not somatic cells, predominantly use homologous recombination to repair double-strand DNA breaks. Stem Cells Dev 2010; 19:1699-711. [PMID: 20446816 DOI: 10.1089/scd.2010.0058] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Embryonic stem (ES) cells give rise to all cell types of an organism. Since mutations at this embryonic stage would affect all cells and be detrimental to the overall health of an organism, robust mechanisms must exist to ensure that genomic integrity is maintained. To test this proposition, we compared the capacity of murine ES cells to repair DNA double-strand breaks with that of differentiated cells. Of the 2 major pathways that repair double-strand breaks, error-prone nonhomologous end joining (NHEJ) predominated in mouse embryonic fibroblasts, whereas the high fidelity homologous recombinational repair (HRR) predominated in ES cells. Microhomology-mediated end joining, an emerging repair pathway, persisted at low levels in all cell types examined. The levels of proteins involved in HRR and microhomology-mediated end joining were highly elevated in ES cells compared with mouse embryonic fibroblasts, whereas those for NHEJ were quite variable, with DNA Ligase IV expression low in ES cells. The half-life of DNA Ligase IV protein was also low in ES cells. Attempts to increase the abundance of DNA Ligase IV protein by overexpression or inhibition of its degradation, and thereby elevate NHEJ in ES cells, were unsuccessful. When ES cells were induced to differentiate, however, the level of DNA Ligase IV protein increased, as did the capacity to repair by NHEJ. The data suggest that preferential use of HRR rather than NHEJ may lend ES cells an additional layer of genomic protection and that the limited levels of DNA Ligase IV may account for the low level of NHEJ activity.
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Affiliation(s)
- Elisia D Tichy
- Department of Cell and Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0524, USA.
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Wang X, Pavelic ZP, Li YQ, Wang L, Gleich L, Radack K, Gluckman JL, Stambrook PJ. Amplification and overexpression of the cyclin D1 gene in head and neck squamous cell carcinoma. Mol Pathol 2010; 48:M256-9. [PMID: 16696017 PMCID: PMC407980 DOI: 10.1136/mp.48.5.m256] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Aims-To determine cyclin D1 gene amplification and expression levels in head and neck squamous cell carcinoma (HNSCC) patients.Methods-Total RNA and genomic DNA were isolated from 40 samples of HNSCC tissue and matched normal tissue and were hybridised with a cyclin D1 cDNA probe. Northern and Southern analyses were used to detect mRNA overexpression and cyclin D1 gene amplification, respectively.Results-15 of the 40 HNSCC samples examined (38%) showed cyclin D1 gene amplification. Of these 15 samples, all 13 from which RNA was available showed increased cyclin D1 expression.Conclusions-HNSCC patients with both amplification and overexpression of the cyclin D1 gene are at greater risk than patients who showed no cyclin D1 gene amplification; amplification and over-expression of the cyclin D1 gene may play an important role in the progression of HNSCC and in clinical outcome.
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Affiliation(s)
- X Wang
- Department of Cell Biology, Neurobiology and Anatomy, College of Medicine, University of Cincinnati, 231 Bethesda Avenue, Cincinnati, Ohio 45267-0521, USA
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26
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Li YQ, Pavelic ZP, Wang LJ, McDonald JS, Gleich L, Munck-Wikland E, Dacic S, Danilovic Z, Pavelic LJ, Wilson KM, Gluckman JL, Stambrook PJ. Altered p53 in microdissected, metachronous, premalignant and malignant oral lesions from the same patients. Mol Pathol 2010; 48:M269-72. [PMID: 16696020 PMCID: PMC407983 DOI: 10.1136/mp.48.5.m269] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Aims-To determine whether mutant p53 alleles harboured by malignant tumours of the oral cavity were also present in previous premalignant lesions at the same site.Methods-Paraffin embedded tumour specimens along with their premalignant counterparts were analysed for p53 alterations using immunohistochemistry, microdissection, polymerase chain reaction amplification, and DNA sequencing.Results-Malignant lesions from five of eight patients showed overexpression of p53 protein by immunohistochemistry. Upon DNA sequencing, two of these five specimens had p53 mutations. Of the five patients whose cancers showed p53 overexpression by immunohistochemistry, three had previous premalignant lesions that also had immunohistochemically detectable p53 protein. However, DNA sequencing showed that none of these three had mutations in the p53 gene. The remaining five premalignant lesions had no immunohistochemically detectable p53 protein.Conclusions-Some premalignant lesions have increased p53 protein which can be detected by staining with antibody to p53. This staining is not caused by mutations in p53 that are found in subsequent tumours at the same site.
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Affiliation(s)
- Y Q Li
- Department of Otolaryngology-Head and Neck Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA
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27
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Andrysik Z, Bernstein WZ, Deng L, Myer DL, Li YQ, Tischfield JA, Stambrook PJ, Bahassi EM. The novel mouse Polo-like kinase 5 responds to DNA damage and localizes in the nucleolus. Nucleic Acids Res 2010; 38:2931-43. [PMID: 20100802 PMCID: PMC2875007 DOI: 10.1093/nar/gkq011] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Polo-like kinases (Plk1-4) are emerging as an important class of proteins involved in many aspects of cell cycle regulation and response to DNA damage. Here, we report the cloning of a fifth member of the polo-like kinase family named Plk5. DNA and protein sequence analyses show that Plk5 shares more similarities with Plk2 and Plk3 than with Plk1 and Plk4. Consistent with this observation, we show that mouse Plk5 is a DNA damage inducible gene. Mouse Plk5 protein localizes predominantly to the nucleolus, and deletion of a putative nucleolus localization signal (NoLS) within its N-terminal moiety disrupts its nucleolar localization. Ectopic expression of Plk5 leads to cell cycle arrest in G1, decreased DNA synthesis, and to apoptosis, a characteristic it shares with Plk3. Interestingly, in contrast to mouse Plk5 gene, the sequence of human Plk5 contains a stop codon that produces a truncated protein lacking part of the kinase domain.
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Affiliation(s)
- Zdenek Andrysik
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA
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Abstract
Embryonic stem (ES) cells and germ cells have the potential to give rise to an entire organism. A common requirement is that both must have very robust mechanisms to preserve the integrity of their genomes. This is particularly true since somatic cells have very high mutation frequencies approaching 10-4 in vivo that would lead to unacceptable levels of fetal lethality and congenital defects. Notably, between 70% and 80% of mutational events monitored at a heterozygous endogenous selectable marker were loss of heterozygosity due to mitotic recombination, a mechanism that affects multiple heterozygous loci between the reporter gene and the site of crossing over. This chapter examines three mechanisms by which mouse embryonic stem cells preserve their genomic integrity. The first entails suppression of mutation and recombination between chromosome homologues by two orders of magnitude when compared with isogenic mouse embryo fibroblasts which had a mutation frequency similar to that seen in adult somatic cells. The second renders mouse ES cells hypersensitive to environmental challenge and eliminates damaged cells from the self-renewing population. Mouse ES cells lack a G1 checkpoint so that cells damaged by exogenous insult such as ionizing radiation do not arrest at the G1/S phase checkpoint but progress into the S phase where the damaged DNA is replicated, the damage exacerbated and the cells driven to apoptosis. The third mechanism examines how mouse ES cells repair double strand DNA breaks. Somatic cells predominantly utilize error prone nonhomologous end joining which, from a teleological perspective, would be disadvantageous for ES cells since it would promote accumulation of mutations. When ES cells were tested for the preferred pathway of double strand DNA break repair, they predominantly utilized the high fidelity homology-mediated repair pathway, thereby minimizing the incurrence of mutations during the repair process. When mouse ES cells are induced to differentiate, the predominant repair pathway switches from homology-mediated repair to nonhomologous end joining that is characteristic of somatic cells.
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Affiliation(s)
- Peter J Stambrook
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, Ohio, 45267-0524, USA,
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29
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Abstract
Embryonic stem (ES) cells are rapidly proliferating, self-renewing cells that have the capacity to differentiate into all three germ layers to form the embryo proper. Since these cells are critical for embryo formation, they must have robust prophylactic mechanisms to ensure that their genomic integrity is preserved. Indeed, several studies have suggested that ES cells are hypersensitive to DNA damaging agents and readily undergo apoptosis to eliminate damaged cells from the population. Other evidence suggests that DNA damage can cause premature differentiation in these cells. Several laboratories have also begun to investigate the role of DNA repair in the maintenance of ES cell genomic integrity. It does appear that ES cells differ in their capacity to repair damaged DNA compared to differentiated cells. This minireview focuses on repair mechanisms ES cells may use to help preserve genomic integrity and compares available data regarding these mechanisms with those utilized by differentiated cells.
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Affiliation(s)
- Elisia D Tichy
- Department of Cell and Cancer Biology, University of Cincinnati, Cincinnati, OH 45267, USA.
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Abstract
The low-fidelity polymerase eta (poleta) is required for bypass of UV-induced pyrimidine dimers inserting adenine nucleotides opposite these lesions. Mutations in the poleta gene are responsible for the genetic defect in xeroderma pigmentosum variant patients. To study if the lack of poleta significantly elevates spontaneous mutation frequency in various organs and tissues of the mouse, we crossed poleta-deficient mice with transgenic mice harboring a chromosomally integrated lacZ-plasmid reporter construct. In cultured embryonic fibroblasts from the lacZ-poleta(-/-) mice, 2.5 J/m(2) UV irradiation induced approximately 5-fold more mutations than in cells from lacZ control mice, in which an approximately 3-fold increase in mutation frequency was found compared with the normal level. Whereas untreated cells harbored mainly 1-bp deletions, UV induced both transitions and transversions, with the latter type more highly represented in the poleta-null cells than in the controls. No difference in mutation induction between the poleta-null cells and the wild-type cells was observed after treatment with N-ethyl-N-nitrosourea. Having shown the validity of the lacZ model to accurately identify poleta-associated mutagenesis, we then determined the mutant frequency at the lacZ locus in liver, spleen, and small intestine of 12-month-old animals. No differences were found between poleta-null, heterozygous, or littermate control mice. We conclude that the poleta defect is specific for UV damage and has no effect on in vivo mutagenesis in mice.
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Bahassi EM, Ovesen JL, Riesenberg AL, Bernstein WZ, Hasty PE, Stambrook PJ. The checkpoint kinases Chk1 and Chk2 regulate the functional associations between hBRCA2 and Rad51 in response to DNA damage. Oncogene 2008; 27:3977-85. [PMID: 18317453 DOI: 10.1038/onc.2008.17] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The cellular response to the introduction of double strand DNA breaks involves complexes of protein interactions that govern cell cycle checkpoint arrest and repair of the DNA lesions. The checkpoint kinases Chk1 and Chk2 phosphorylate the carboxy-terminal domain of hBRCA2, a protein involved in recombination-mediated DNA repair (HRR) and replication fork maintenance. Cells deficient in hBRCA2 are hypersensitive to DNA damaging agents. Phosphorylation of the residue in hBRCA2 targeted by the Chk1 and Chk2 kinases regulates its interaction with Rad51. Furthermore, the cell line lex1/lex2, which lacks the carboxy-terminal domain containing the phosphorylated residue, does not support localization of Rad51 to nuclear foci after exposure to UV or treatment with ionizing radiation (IR). The data show that either phosphorylation of Rad51 by Chk1 or phosphorylation of the carboxy-terminal domain of hBRCA2 by Chk1 or Chk2 plays a critical role in the binding of Rad51 to hBRCA2 and the subsequent recruitment of Rad51 to sites of DNA damage. While depletion of Chk1 from cells leads to loss of Rad51 localization to nuclear foci in response to replication arrest, cells lacking Chk2 also show a defect in Rad51 localization, but only in presence of double strand DNA breaks, indicating that each of these kinases may contribute somewhat differently to the formation of Rad51 nucleoprotein filaments depending on the type of DNA damage incurred by the cells.
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Affiliation(s)
- E M Bahassi
- Department of Cell and Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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Liang L, Deng L, Mendonca MS, Chen Y, Zheng B, Stambrook PJ, Shao C, Tischfield JA. X-rays induce distinct patterns of somatic mutation in fetal versus adult hematopoietic cells. DNA Repair (Amst) 2007; 6:1380-5. [PMID: 17553756 PMCID: PMC2063444 DOI: 10.1016/j.dnarep.2007.04.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 03/08/2007] [Accepted: 04/17/2007] [Indexed: 01/16/2023]
Abstract
There are a variety of mechanisms and pathways whereby cells safeguard their genomes in the face of environmental insults that damage DNA. Whether each of these pathways is equally robust at specific developmental stages in mammals and whether they are also modulated in a tissue-specific manner, however, are unclear. Here, we report that ionizing radiation (IR) produces different types of somatic mutations in fetal cells compared with adult cells of the same lineage. While 1 Gy of X-ray significantly induced intragenic point mutations in T cells of adult mice, no point mutational effect was observed when applied to fetuses. Fetal exposure to IR, on the other hand, led to a significant elevation of mitotic recombination in T cells, which was not observed in adults. Base excision repair (BER) activity was significantly lower in fetal hematopoietic cells than in adult cells, due to a low level of DNA polymerase beta, the rate-limiting enzyme in BER. In fetal hematopoietic cells, this low BER activity, together with a high rate of proliferation, causes X-ray-induced DNA lesions, such as base damage, single strand breaks and double strand breaks, to be repaired by homologous recombination, which we observe as mitotic recombination. Higher BER activity and a relatively lower rate of cell proliferation likely contribute to the significant induction of DNA point mutations in adults. Thus, the mutational response to IR is at least partly determined by the availability of specific repair pathways and other developmentally regulated phenotypes, such as mitotic index.
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Affiliation(s)
- Li Liang
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, United States
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Abstract
Mutation frequencies at some loci in mammalian somatic cells in vivo approach 10(-4). The majority of these events occur as a consequence of loss of heterozygosity (LOH) due to mitotic recombination. Such high levels of DNA damage in somatic cells, which can accumulate with age, will cause injury and, after a latency period, may lead to somatic disease and ultimately death. This high level of DNA damage is untenable for germ cells, and by extrapolation for embryonic stem (ES) cells, that must recreate the organism. ES cells cannot tolerate such a high frequency of damage since mutations will immediately impact the altered cell, and subsequently the entire organism. Most importantly, the mutations may be passed on to future generations. ES cells, therefore, must have robust mechanisms to protect the integrity of their genomes. We have examined two such mechanisms. Firstly, we have shown that mutation frequencies and frequencies of mitotic recombination in ES cells are about 100-fold lower than in adult somatic cells or in isogenic mouse embryonic fibroblasts (MEFs). A second complementary protective mechanism eliminates those ES cells that have acquired a mutational burden, thereby maintaining a pristine population. Consistent with this hypothesis, ES cells lack a G1 checkpoint, and the two known signaling pathways that mediate the checkpoint are compromised. The checkpoint kinase, Chk2, which participates in both pathways is sequestered at centrosomes in ES cells and does not phosphorylate its substrates (i.e. p53 and Cdc25A) that must be modified to produce a G1 arrest. Ectopic expression of Chk2 does not rescue the p53-mediated pathway, but does restore the pathway mediated by Cdc25A. Wild type ES cells exposed to ionizing radiation do not accumulate in G1 but do so in S-phase and in G2. ES cells that ectopically express Chk2 undergo cell cycle arrest in G1 as well as G2, and appear to be protected from apoptosis.
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Affiliation(s)
- Y Hong
- Department of Cell biology, Neurobiology and Anatomy, University of Cincinnati Medical Center, 3125 Eden Avenue, Cincinnati, OH 45267-0521, USA
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Bahassi EM, Penner CG, Robbins SB, Tichy E, Feliciano E, Yin M, Liang L, Deng L, Tischfield JA, Stambrook PJ. The breast cancer susceptibility allele CHEK2*1100delC promotes genomic instability in a knock-in mouse model. Mutat Res 2006; 616:201-9. [PMID: 17174984 DOI: 10.1016/j.mrfmmm.2006.11.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Allelic variants of CHEK2 contribute to an elevated risk for human breast cancer and possibly other cancer types. In particular, the CHEK2*1100delC polymorphic variant has been identified as a low-penetrance breast cancer susceptibility allele in breast cancer families with wild type BRCA1 and BRCA2. To better understand the molecular basis by which this allele increases risk for disease, we have generated a mouse in which the wild type CHEK2 (Chk2 in mouse) allele has been replaced with the 1100delC variant. Mouse embryo fibroblasts (MEFs) derived from these mice have an altered cell cycle profile in which a far greater proportion of cells are in S-phase and in G2 (4N) compared with wild type cells. The mutant cells show signs of spontaneous genomic instability as indicated by polyploidy and an increase in DNA double strand breaks.
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Affiliation(s)
- El Mustapha Bahassi
- Department of Cell Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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35
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Abstract
Many physiological and cellular processes contribute to the ageing of individuals. One hypothesis argues that the genomes of somatic cells accumulate mutations, which, in turn, alter the metabolism of the cells and contribute to the ageing process. The frequency of somatic mutation approaches 10(-4) and the majority of mutagenic events at heterozygous loci is due to loss of heterozygosity as a consequence of mitotic recombination. A corollary to the argument that somatic cells accumulate mutations is that cells of the germ line and ES cells have a greater requirement for maintaining the integrity of their genomes. In the former case, a high somatic mutation frequency predicts an increase in somatic disease, which limits our lifespan. The corollary is that cells of the germline and ES cells must minimize the mutational burden to limit the frequency of congenital disease and to ensure the proper transmission of undamaged DNA to the gene pool. This report describes two mechanisms utilized by murine ES cells to minimize DNA damage within the proliferative pool. In the first case, murine ES cells display a frequency of mutation and mitotic recombination that is about 100-fold lower than that observed in somatic cells. Second, ES cells lack a G1 checkpoint following DNA damage. When subjected to ionizing radiation, the fraction of apoptotic cells increases to about 40%. Ectopic expression of Chk2 is sufficient to establish a G1 arrest and the concomitant protection from cell death.
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Affiliation(s)
- Peter J Stambrook
- Department of Cell and Cancer Biology, 3125 Eden Avenue, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0521, USA.
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36
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Abstract
Mutation in embryonic stem (ES) cells can potentially compromise multiple cell lineages and affect the well-being of subsequent generations. Thus, ES cells require sensitive mechanisms to maintain genomic integrity. One mechanism involves suppression of mutation. A complementary mechanism is to regulate the cell cycle checkpoint and facilitate cell death. Here, we describe the detailed protocols we have used to investigate DNA damage response and mutagenesis in mouse ES cells.
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Affiliation(s)
- Yiling Hong
- Department of Cell Biology, Neurobiology and Anatomy, University of Cincinnati College of Medicine, OH, USA
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37
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Fischer JM, Robbins SB, Kannamkumarath SS, Al-Zoughool M, Stringer SL, Talaska G, Caruso JA, Stambrook PJ, Stringer JR. Exposure of mice to arsenic and/or benzo[a]pyrene does not increase the frequency of Aprt-deficient cells recovered from explanted skin of Aprt heterozygous mice. Environ Mol Mutagen 2006; 47:334-44. [PMID: 16649189 DOI: 10.1002/em.20212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Exposure to inorganic arsenic in drinking water is linked to cancer in humans, but the mechanism of arsenic-induced cancer is not clear. Arsenic is not a powerful point mutagen, but can cause chromosome malsegregation and mitotic recombination, two events that can cause loss of tumor suppressor alleles and thereby contribute to the evolution of cancerous cells. To determine whether arsenic increases the frequency of allele loss due to either malsegregation or mitotic recombination in vivo, Aprt(+/-) hybrid mice were exposed to sodium arsenite (10 mg/L) in their drinking water for 10 weeks. To determine whether arsenic enhances the action of a known mutagen, half of the arsenic-treated mice were exposed to benzo[a]pyrene (BaP) for 8 weeks by skin painting (500 nmoles/week). Cells were taken from painted dorsal skin and cultured in the presence of 2,6-diaminopurine (DAP), to select colonies lacking adenosine phosphoribosyl transferase (Aprt) activity. The frequency of DAP-resistant (DAP(r)) colonies varied substantially within the treatment groups, but there was no significant difference between the groups. Analysis of DNA from DAP(r) colonies suggested that mitotic recombination contributed to the loss of wild-type Aprt allele. Whether arsenic or BaP enhanced or diminished the frequency of this process could not be deduced from these data.
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Affiliation(s)
- Jared M Fischer
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Ohio, USA
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38
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Bahassi EM, Myer DL, McKenney RJ, Hennigan RF, Stambrook PJ. Priming phosphorylation of Chk2 by polo-like kinase 3 (Plk3) mediates its full activation by ATM and a downstream checkpoint in response to DNA damage. Mutat Res 2006; 596:166-76. [PMID: 16481012 DOI: 10.1016/j.mrfmmm.2005.12.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The tumor suppressor gene Chk2 encodes a serine/threonine kinase that signals DNA damage to cell cycle checkpoints. In response to ionizing radiation, Chk2 is phosphorylated on threonine 68 (T68) by ataxia-telangiectasia mutated (ATM) protein leading to its activation. We have previously shown that polo-like kinase 3 (Plk3), a protein involved in DNA damage checkpoint and M-phase functions, interacts with and phosphorylates Chk2. When Chk2 was immunoprecipitated from Daudi cells (Plk3-deficient), it had weak kinase activity towards Cdc25C compared with Chk2 derived from T47D cells (Plk3-expressing cells). This activity was restored by addition of recombinant Plk3 in a dose-dependent manner. Plk3 phosphorylates Chk2 at two residues, serine 62 (S62) and serine 73 (S73) in vitro, and this phosphorylation facilitates subsequent phosphorylation of Chk2 on T68 by ATM in response to DNA damage. When the Chk2 mutant construct GFP-Chk2 S73A (serine 73 mutated to alanine) is transfected into cells, it no longer associates with a large complex in vivo, and manifests a significant reduction in kinase activity. It is also inefficiently activated by ATM by phosphorylation at T68 and, in turn, is unable to phosphorylate the Cdc25C peptide 200-256, which contains the inhibitory S216 target phosphorylation residue. As a consequence, tyrosine 15 (Y15) on Cdc2 remains hypophosphorylated, and there is a loss of the G2/M checkpoint. These data describe a functional role for Plk3 in a pathway linking ATM, Plk3, Chk2, Cdc25C and Cdc2 in cellular response to DNA damage.
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Affiliation(s)
- El Mustapha Bahassi
- Department of Cell Biology, University of Cincinnati College of Medicine, 3125 Eden Avenue, Cincinnati, OH 45267, USA
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39
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Fischer JM, Robbins SB, Al-Zoughool M, Kannamkumarath SS, Stringer SL, Larson JS, Caruso JA, Talaska G, Stambrook PJ, Stringer JR. Co-mutagenic activity of arsenic and benzo[a]pyrene in mouse skin. Mutation Research/Genetic Toxicology and Environmental Mutagenesis 2005; 588:35-46. [PMID: 16242380 DOI: 10.1016/j.mrgentox.2005.09.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2005] [Revised: 08/17/2005] [Accepted: 09/09/2005] [Indexed: 12/11/2022]
Abstract
Exposure to inorganic arsenic in drinking water is linked to skin, lung and bladder cancer in humans. The mechanism of arsenic-induced cancer is not clear, but exposure to arsenic and polycyclic arylhydrocarbons (PAH) is more carcinogenic than exposure to either type of carcinogen alone. Arsenic can also generate reactive oxygen species, suggesting that oxidation of DNA may play a role in carcinogenesis. Oxidization of guanosines in polyG tracts is known to cause frameshift mutations, and such events can be detected in situ using the G11 placental alkaline phosphatase (PLAP) transgenic mouse model, which reports frameshift mutations in a run of 11 G:C basepairs by generating cells containing heat-resistant alkaline phosphatase activity. PAH can also induce frameshift mutations. In the study described here, FVB/N mice carrying the G11 PLAP transgene were crossed to C57Bl/6 mice. Half of the hybrid mice were given drinking water with sodium arsenite (10 mg/L) for 10 weeks. Half of the arsenic treated mice were also exposed to benzo[a]pyrene (BaP) by skin painting (500 nmol/week) for 8 weeks. Another group of mice was exposed to BaP but not arsenic. The effect on frameshift mutation was assessed by staining sections of skin tissue to detect cells with PLAP activity. Arsenic alone had no significant effect. On average, mice given BaP alone had approximately three times more PLAP-positive (PLAP+) cells. By contrast, mice exposed to both arsenic and BaP exhibited 10-fold more PLAP+ cells in the skin, and these cells were often arranged in large clusters, suggesting derivation from stem cells. Whereas combined treatment produced more PLAP+ cells, stable BaP adduct levels and arsenic burdens were not higher in mice exposed to both agents compared to mice exposed to either one agent or the other.
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Affiliation(s)
- Jared M Fischer
- University of Cincinnati, Department of Molecular Genetics, Biochemistry and Microbiology, 231 Albert Sabin Way, Cincinnati, OH 45267-0524, USA
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40
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Abstract
Mitotic recombination (MR) between chromosome homologs in somatic cells is a major pathway to the loss of heterozygosity (LOH), which may cause cancer if tumor suppressor genes are involved. MR can be suppressed by DNA sequence heterology (homeology) in hybrid mice from matings between species or between subspecies. We now report that MR is relatively suppressed in F1 hybrids between inbred strains C57BL/6 and 129S2. The frequency of MR in fibroblasts is lower in F1 hybrid mice than in either of the two parental strains. However, MR in T cells is not affected by strain background. Thus, relatively small genetic differences are capable of restricting MR in a tissue-specific manner. Using Mlh1-deficient mice, we tested the role of mismatch repair in MR in two isogenic cell types. In fibroblasts of C57BL/6 x 129S2 F1 mice, the suppression of MR is alleviated in the absence of MLH1. In contrast, MR is not affected by Mlh1 status in T cells. The frequency of point mutations at the reporter gene loci Aprt and Hprt, on the other hand, is significantly increased in both T cells and fibroblasts of Mlh1(-/-) mice. Thus, different cell types respond differently to MLH1 deficiency, and the contribution of MR to tumorigenesis may be tissue-dependent in the absence of mismatch repair.
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Affiliation(s)
- Changshun Shao
- Department of Genetics, Rutgers University, 604 Allison Road, Piscataway, NJ 08854-8082, USA.
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41
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Abstract
Polo-like kinases (Plks) are key regulators of the cell cycle, especially in the G2 phase and mitosis. They are incorporated into signaling networks that regulate many aspects of the cell cycle, including but not limited to centrosome maturation and separation, mitotic entry, chromosome segregation, mitotic exit, and cytokinesis. The Plks have well conserved 30-amino-acid elements, designated polo boxes (PBs), located in their carboxyl-termini, which with their flanking regions constitute a functional Polo-box domain (PBD). Members of the Plk family exist in a variety of organisms including Polo in Drosophila melanogaster; Cdc5 in Saccharomyces cerevisiae; Plo1 in Schizosaccharomyces pombe; Plx1 in Xenopus laevis; and Plk1, Snk/Plk2, Fnk/Prk/Plk3, and Sak in mammals. Polo, Cdc5, and Plo1 are essential for viability. The Plks can be separated into two groups according to their functions. The first group (Polo, Cdc5, plo1, Plx1, and Plk1) primarily performs mitotic functions, whereas the second group (Plk2 and Plk3) appears to have additional functions during the G1, S, and G2 phases of the cell cycle. Several contributions to this issue will discuss different aspects of Plk involvement in cell-cycle regulation. This review, therefore, will focus on the role of Plk3 in regulating Cdc25 phosphatase function and its effect on the cell cycle.
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Affiliation(s)
- David L Myer
- Department of Cell Biology, Neurobiology and Anatomy, University of Cincinnati College of Medicine, 3125 Eden Avenue, Cincinnati, OH 45267, USA
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42
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Hong Y, Stambrook PJ. Restoration of an absent G1 arrest and protection from apoptosis in embryonic stem cells after ionizing radiation. Proc Natl Acad Sci U S A 2004; 101:14443-8. [PMID: 15452351 PMCID: PMC521944 DOI: 10.1073/pnas.0401346101] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2004] [Indexed: 12/31/2022] Open
Abstract
Response to DNA damage and cell-cycle regulation differ markedly between embryonic stem (ES) cells and somatic cells. ES cells require exquisitely sensitive mechanisms to maintain genomic integrity and do so, in part, by suppressing spontaneous mutation. Spontaneous mutation frequency in somatic cells is approximately 10(-4) compared with 10(-6) for ES cells. ES cells also lack a G(1) checkpoint and are hypersensitive to IR and other DNA-damaging agents. These characteristics facilitate apoptosis and the removal of cells with a mutational burden from the population, thereby keeping the population free of damaged cells. Here, we identify signaling pathways that are compromised and lead to a natural absence of aG(1) arrest in ES cells after DNA damage. The affected pathways are those mediated by p53 and p21 and by ATM, Chk2, Cdc25A, and Cdk2. In ES cells, Chk2 kinase is not intranuclear as in somatic cells but is sequestered at centrosomes and is unavailable to phosphorylate Cdc25A phosphatase and cause its degradation. Although ectopic expression of Chk2 does not rescue the p53/p21 pathway, its expression is sufficient to allow it to phosphorylate Cdc25A, activate downstream targets, restore a G(1) arrest, and protect the cell from apoptosis.
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Affiliation(s)
- Yiling Hong
- Department of Cell Biology, Neurobiology, and Anatomy, University of Cincinnati College of Medicine, 3125 Eden Avenue, Cincinnati, OH 45267, USA
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43
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Abstract
Although the evolution of '-omics' methodologies is still in its infancy, both the pharmaceutical industry and patients could benefit from their implementation in the drug development process
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Affiliation(s)
- Sandra Kraljevic
- Sandra Kraljevic and Kresimir Pavelic (bottom) are in the Laboratory of Functional Genomics at the Rudjer Boskovic Institute's Division of Molecular Medicine in Zagreb, Croatia.
| | - Peter J. Stambrook
- Peter J. Stambrook is in the Department of Cell Biology, Neurobiology and Anatomy at the University of Cincinnati Medical Center in Ohio, USA
| | - Kresimir Pavelic
- Sandra Kraljevic and Kresimir Pavelic (bottom) are in the Laboratory of Functional Genomics at the Rudjer Boskovic Institute's Division of Molecular Medicine in Zagreb, Croatia.
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Abstract
OBJECTIVES/HYPOTHESIS Alloantigen gene therapy with the genes for the Class I major histocompatibility complex (MHC) HLA-B7 and beta 2-microglobulin in HLA-B7-negative patients has potential efficacy in the treatment of head and neck cancer, although the mechanism of response is unclear. Whether tumor regression is due to a response to HLA-B7 in HLA-B7-negative patients (i.e., due to "foreign" antigen) or simply to MHC overexpression is unknown. Therefore, a mouse model was used to compare tumor growth following syngeneic MHC transfection to alloantigenic MHC transfection. The importance of the beta 2-microglobulin gene was also evaluated. STUDY DESIGN Prospective animal study. METHODS The head and neck cancer cell line SCC-VII that grows in immunocompetent C3H mice, which are MHC haplotype H2-K, was used. Stable transfections were made with H2-K, H2-K, and beta 2-microglobulin in the SCC-VII cells. To test the importance of MHC "foreignness," mice were injected with SCC-VII cells, SCC-VII plus H2-K plus beta 2-microglobulin transfected cells, and SCC-VII plus H2-K plus beta 2-microglobulin transfected cells. To evaluate beta 2-microglobulin, mice were injected with SCC-VII cells, SCC-VII plus H2-K plus beta 2-microglobulin transfected cells, SCC-VII plusH2-K transfected cells, and SCC-VII plus beta 2-microglobulin transfected cells. Tumor growth in all groups was compared statistically. RESULTS Major histocompatibility complex foreignness was a part of the antitumor response. Foreign MHC routinely abrogated tumor growth, whereas syngeneic MHC only slowed tumor growth. beta 2-microglobulin aided the MHC tumor inhibition but did not inhibit tumor without the MHC. CONCLUSION The antitumor response was greater when the MHC gene used was foreign. beta 2-microglobulin increased the efficacy of MHC gene therapy. Both of these findings are important when designing clinical trials of immunologically based gene therapies for head and neck cancer.
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Affiliation(s)
- Frank N Salamone
- Departments of Otolaryngology-Head and Neck Surgery, The University of Cincinnati Medical Center, Cincinnati, Ohio, U.S.A.
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45
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Abstract
Mitosis in human cells is initiated at the end of G2 by activation of the Cdc2/cyclin B complex. Activation occurs by dephosphorylation of the inhibitory residues, threonine 14 (T14) and tyrosine 15 (Y15), on Cdc2 by the Cdc25C phosphatase. Entry into mitosis is regulated by the subcellular relocalization of Cdc2/cyclin B, which is rapidly imported into the nucleus at the end of G2. Here, we show that polo-like kinase 3 (Plk3) is able to phosphorylate Cdc25C primarily on S191, and to a lesser extent on S198 in vitro, both of which are within a nuclear exclusion motif. Following transfection, the S191D Cdc25C mutant leads to an enhanced accumulation of Cdc25C in the nucleus, while the S191A mutant facilitated the Cdc25C nuclear exclusion. Furthermore, translocation of Cdc25C to the nucleus was accompanied by a decrease in Cdc2 phosphorylation on Y15. Plk3-WT overexpression led to a sharp increase in Cdc25C nuclear accumulation, while Plk3-KD overexpression failed to do so. The effect of Plk3 overexpression on Cdc25C was reversed by coexpression of a Plk3 siRNA. These results support a role for the polo kinases in coordinating the translocation and perhaps the timing of both Cdc25C and its target Cdc2/cyclin B to the nucleus upon entry into mitosis.
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Affiliation(s)
- El Mustapha Bahassi
- Department of Cell Biology, University of Cincinnati College of Medicine, 3125 Eden Avenue, Cincinnati, OH 45267, USA
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46
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Tzortzaki EG, Yang M, Glass D, Deng L, Evan AP, Bledsoe SB, Stambrook PJ, Sahota A, Tischfield JA. Impaired expression of an organic cation transporter, IMPT1, in a knockout mouse model for kidney stone disease. Urol Res 2003; 31:257-61. [PMID: 12856169 DOI: 10.1007/s00240-003-0318-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2002] [Accepted: 03/20/2003] [Indexed: 10/26/2022]
Abstract
The imprinted multimembrane-spanning polyspecific transporter-like gene 1 ( IMPT1) encodes a predicted protein with organic cation transport capabilities. As a first step in understanding the function of IMPT1, we identified the renal structures expressing this gene in knockout mice with adenine phosphoribosyltransferase (APRT) deficiency and 2,8-dihydroxyadenine (DHA) nephrolithiasis. IMPT1 mRNA was not detected using a standard in situ hybridization (ISH) protocol, but we observed intense staining in cortico-medullary tubules and glomeruli in wild-type mice using an improved reverse transcription-polymerase chain reaction (RT-PCR) ISH procedure. IMPT1 mRNA expression was significantly decreased in the cortical region in kidney sections from APRT-deficient male mice. APRT-deficient female mice are less severely affected by DHA-induced kidney stone disease, and we observed only a modest reduction in IMPT1 expression in kidneys from these mice. IMPT1 expression in APRT heterozygous mice was comparable to that in wild-type mice, suggesting imprinting of one of the parental alleles. These findings suggest that decreased IMPT1 mRNA expression may contribute to the impaired renal function in APRT-deficient male mice, and that RT-PCR ISH is a valuable tool for localizing the site of expression of transcripts that are not detectable using standard ISH procedures.
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Affiliation(s)
- Eleni G Tzortzaki
- Department of Genetics, Rutgers University, 604 Allison Road, NJ 08854-8082, Piscataway, USA
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47
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Wang L, Raikwar N, Yang M, Deng L, McAteer JA, Stambrook PJ, Sahota A, Tischfield JA. Induction of alpha-catenin, integrin alpha3, integrin beta6, and PDGF-B by 2,8-dihydroxyadenine crystals in cultured kidney epithelial cells. Exp Nephrol 2003; 10:365-73. [PMID: 12381921 DOI: 10.1159/000065301] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Homozygous adenine phosphoribosyltransferase (APRT) deficiency is associated with 2,8-dihydroxyadenine (DHA) nephrolithiasis. Using whole kidney RNA from Aprt knockout mice, we previously showed that the renal deposition of DHA leads to changes in the expression of genes involved in tissue injury. To determine the cellular basis for these changes, we investigated gene expression in cultured human kidney (NHK-C) and African green monkey (BSC-1) epithelial cells exposed to DHA or calcium oxalate monohydrate (COM) crystals. METHODS First-strand cDNAs, synthesized from mRNA isolated from treated and untreated cells, were hybridized to membrane-bound cDNA arrays containing 588 genes associated with various physiological and pathological processes. Changes in gene expression were confirmed by reverse transcription PCR. RESULTS Twenty-seven percent of the array cDNAs were expressed in untreated NHK-C cells at varying levels relative to a housekeeping gene. The expression of three adhesion molecules (alpha-catenin, integrin alpha3, and integrin beta6) and platelet-derived growth factor B (PDGF-B) was elevated following exposure of NHK-C cells to DHA. Increased expression of the adhesion molecules was also observed in BSC-1 cells, but PDGF-B expression could not be detected. COM crystals also stimulated the expression of these four genes in NHK-C cells, but the expression profile was quantitatively different compared with DHA. CONCLUSIONS These findings suggest that DHA crystals stimulate the expression of specific genes in kidney epithelial cells and that the pathways for DHA-induced cell injury may be similar to those for COM crystals. The induction of adhesion molecules and PDGF-B may affect cell-cell or cell-matrix interactions and/or alter the actin cytoskeleton. These alterations may ultimately contribute to crystal-induced renal injury.
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Affiliation(s)
- Li Wang
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Ind, USA
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48
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Abstract
BACKGROUND Human trials of alloantigen gene therapy, using the class I major histocompatibility complex (MHC) HLA-B7, have demonstrated the potential efficacy of this treatment for head and neck cancer. Its mechanism remains unclear. An immune-competent mouse model of MHC gene therapy to test factors potentially important to the tumor response is needed. METHODS Two cell lines were used, B4B8 cells that grow in Balb/c mice and SCC-VII cells that grow in C3H mice. The mouse MHC H2-K(b) was used as the therapeutic gene, because it is an alloantigen to both mice strains. Plasmids that encode the H2-K(b) cDNA were prepared, and the cell lines were transfected. Mice were injected subcutaneously with naive cells to determine the tumor kinetics and serve as controls. Mice were injected with H2-K(b) transfected cells and tumor growth was compared with controls. Mice that did not grow tumor were rechallenged with naive cells to assess for tumor immunity. Mice were injected with transfected and naive cells admixed to determine whether the concentration of the alloantigen is important. RESULTS B4B8 tumors grew slowly, whereas SCC-VII tumors grew rapidly. Transfection with H2-K(b) plasmid prevented or inhibited tumor growth of both the B4B8 and SCC-VII tumors. This growth inhibition was independent of the number of cells injected. In the mice that did not grow tumor, tumor immunity was demonstrated after challenge with naive cells in both models. There was no relationship between induction of immunity and the timing of the challenge or initial cell quantity. The mice injected with a mixture of naive and transfected cells grew tumor, although growth was delayed in the B4B8 model. CONCLUSIONS The results demonstrate that the two mouse models can serve as a rapid and slow growing tumor model of alloantigen gene therapy. In addition, it was noted that initial tumor cell number is not a significant factor for predicting tumor response and demonstrated that in both of these models alloantigen gene therapy results in significant antitumor immunity.
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Affiliation(s)
- Lyon L Gleich
- Department of Otolaryngology-Head and Neck Surgery, University of Cincinnati Medical Center, P.O. Box 670528, 213 Albert Sabin Way, Cincinnati, Ohio 45267-0528, USA.
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Dong J, Bohinski RJ, Li YQ, Van Waes C, Hendler F, Gleich L, Stambrook PJ. Antitumor effect of secreted Flt3-ligand can act at distant tumor sites in a murine model of head and neck cancer. Cancer Gene Ther 2003; 10:96-104. [PMID: 12536197 DOI: 10.1038/sj.cgt.7700534] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2002] [Indexed: 11/09/2022]
Abstract
The Flt3 ligand (Flt3-L) manifests antitumor activity, presumably due to its capacity to recruit dendritic cells and cause their proliferation. To assess whether local production of Flt3-L can mediate a "distant bystander" effect, murine B4B8 squamous cell carcinoma cells were transfected with a plasmid encoding a secretory form of Flt3-L to produce B4B8FL cells. Similarly, B4B8FL and B4B8 cells were transfected with herpes simplex virus thymidine kinase (HSVTK) to produce B4B8TK and B4B8FL/TK cells, which should be sensitive to ganciclovir (GCV), to know whether the effects of Flt3-L and HSVTK/GCV would be synergistic. To test for a distant bystander effect in vivo, B4B8FL, B4B8TK, and B4B8FL/TK cells were injected subcutaneously into the left flank of syngeneic Balb/c mice, and naïve B4B8 cells were injected into the right flank. The formation of tumors derived from B4B8FL and B4B8FL/TK cells was significantly delayed in both flanks compared with naïve B4B8 and B4B8TK cells. Growth of B4B8TK tumors in the ipsilateral flank was retarded following GCV treatment, but in contrast to B4B8FL and B4B8FL/TK cells, no distant bystander effect in the contralateral flank was observed. Immunohistochemistry showed lymphocytic infiltrates in both flanks of the B4B8FL and B4B8FL/TK groups. The data indicate that in these cells, local secretion of Flt3-L is sufficient to evoke a distant bystander effect but that expression of HSVTK, even after GCV administration, is not. Furthermore, the combination of local Flt3-L and HSVTK production, together with GCV administration, does not enhance the distant bystander effect produced by Flt3-L alone.
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Affiliation(s)
- Jian Dong
- Department of Cell Biology, Vontz Center for Molecular Studies, University of Cincinnati, Cincinnati, Ohio 45267-0521, USA
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50
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Tzortzaki EG, Glass D, Yang M, Evan AP, Bledsoe SB, Stambrook PJ, Sahota A, Tischfield JA. Gender- and age-dependent changes in kidney androgen protein mRNA expression in a knockout mouse model for nephrolithiasis. J Histochem Cytochem 2002; 50:1663-9. [PMID: 12486089 DOI: 10.1177/002215540205001211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Kidney androgen-regulated protein (Kap) is the most abundant protein in the mouse kidney, but its function is unknown. We previously observed a significant decrease in Kap mRNA expression in whole kidney tissue from male mice with adenine phosphoribosyltransferase (APRT) deficiency and 2,8-dihydroxyadenine (DHA) nephrolithiasis. The disease phenotype is more severe in male mice and is age-dependent. To identify the cellular basis for differential Kap expression, we used in situ hybridization (ISH) and reverse transcription-polymerase chain reaction ISH (RT-PCR ISH) to identify the cell types expressing this mRNA in paraffin-embedded kidney sections. In 1-month-old wild-type male mice, Kap was detected primarily in S3 proximal tubule segments, but expression was very low in female mice. In 1-month-old APRT-deficient male mice, Kap expression was decreased significantly and was undetectable in female mice. Kap mRNA was not detected in 3- or 6-month-old mice using our standard ISH protocol, but we observed intense cytoplasmic staining in S3 proximal tubules in wild-type male mice of these age groups using an improved RT-PCR ISH procedure. Our studies demonstrate age-, gender-, and APRT genotype-dependent changes in Kap mRNA expression in mouse kidney. Kap expression is under multihormonal control, and hormonal changes in DHA-induced nephrolithiasis may account for the decreased Kap expression in APRT-deficient mice.
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Affiliation(s)
- Eleni G Tzortzaki
- Department of Genetics, Rutgers University, Piscataway, New Jersey 08854, USA
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