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Islam A, Shaukat Z, Hussain R, Ricos MG, Dibbens LM, Gregory SL. Aneuploidy is Linked to Neurological Phenotypes Through Oxidative Stress. J Mol Neurosci 2024; 74:50. [PMID: 38693434 PMCID: PMC11062972 DOI: 10.1007/s12031-024-02227-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 04/19/2024] [Indexed: 05/03/2024]
Abstract
Aneuploidy, having an aberrant genome, is gaining increasing attention in neurodegenerative diseases. It gives rise to proteotoxic stress as well as a stereotypical oxidative shift which makes these cells sensitive to internal and environmental stresses. A growing body of research from numerous laboratories suggests that many neurodegenerative disorders, especially Alzheimer's disease and frontotemporal dementia, are characterised by neuronal aneuploidy and the ensuing apoptosis, which may contribute to neuronal loss. Using Drosophila as a model, we investigated the effect of induced aneuploidy in GABAergic neurons. We found an increased proportion of aneuploidy due to Mad2 depletion in the third-instar larval brain and increased cell death. Depletion of Mad2 in GABAergic neurons also gave a defective climbing and seizure phenotype. Feeding animals an antioxidant rescued the climbing and seizure phenotype. These findings suggest that increased aneuploidy leads to higher oxidative stress in GABAergic neurons which causes cell death, climbing defects, and seizure phenotype. Antioxidant feeding represents a potential therapy to reduce the aneuploidy-driven neurological phenotype.
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Affiliation(s)
- Anowarul Islam
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, 5042, Australia
- Epilepsy Research Group, Australian Centre for Precision Health, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Zeeshan Shaukat
- Epilepsy Research Group, Australian Centre for Precision Health, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Rashid Hussain
- Epilepsy Research Group, Australian Centre for Precision Health, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Michael G Ricos
- Epilepsy Research Group, Australian Centre for Precision Health, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Leanne M Dibbens
- Epilepsy Research Group, Australian Centre for Precision Health, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Stephen L Gregory
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, 5042, Australia.
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2
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Islam A, Shaukat Z, Newman DL, Hussain R, Ricos MG, Dibbens L, Gregory SL. Chromosomal Instability Causes Sensitivity to Polyamines and One-Carbon Metabolism. Metabolites 2023; 13:metabo13050642. [PMID: 37233683 DOI: 10.3390/metabo13050642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/02/2023] [Accepted: 05/04/2023] [Indexed: 05/27/2023] Open
Abstract
Aneuploidy, or having a disrupted genome, is an aberration commonly found in tumours but rare in normal tissues. It gives rise to proteotoxic stress as well as a stereotypical oxidative shift, which makes these cells sensitive to internal and environmental stresses. Using Drosophila as a model, we investigated the changes in transcription in response to ongoing changes to ploidy (chromosomal instability, CIN). We noticed changes in genes affecting one-carbon metabolism, specifically those affecting the production and use of s-adenosyl methionine (SAM). The depletion of several of these genes has led to cell death by apoptosis in CIN cells but not in normal proliferating cells. We found that CIN cells are particularly sensitive to SAM metabolism at least partly because of its role in generating polyamines. Feeding animals spermine was seen to rescue the cell death caused by the loss of SAM synthase in CIN tissues. The loss of polyamines led to decreased rates of autophagy and sensitivity to reactive oxygen species (ROS), which we have shown to contribute significantly to cell death in CIN cells. These findings suggest that a well-tolerated metabolic intervention such as polyamine inhibition has the potential to target CIN tumours via a relatively well-characterised mechanism.
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Affiliation(s)
- Anowarul Islam
- College of Medicine and Public Health, Flinders University, Adelaide 5042, Australia 2 Clinical and Health Sciences, University of South Australia, Adelaide 5001, Australia 3 School of Biological Sciences, University of Adelaide, Adelaide 5006, Australia
- Clinical and Health Sciences, University of South Australia, Adelaide 5001, Australia
| | - Zeeshan Shaukat
- Clinical and Health Sciences, University of South Australia, Adelaide 5001, Australia
| | - David L Newman
- School of Biological Sciences, University of Adelaide, Adelaide 5006, Australia
| | - Rashid Hussain
- Clinical and Health Sciences, University of South Australia, Adelaide 5001, Australia
| | - Michael G Ricos
- Clinical and Health Sciences, University of South Australia, Adelaide 5001, Australia
| | - Leanne Dibbens
- Clinical and Health Sciences, University of South Australia, Adelaide 5001, Australia
| | - Stephen L Gregory
- College of Medicine and Public Health, Flinders University, Adelaide 5042, Australia 2 Clinical and Health Sciences, University of South Australia, Adelaide 5001, Australia 3 School of Biological Sciences, University of Adelaide, Adelaide 5006, Australia
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3
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Liu D, Shaukat Z, Hussain R, Khan M, Gregory SL. Drosophila as a model for chromosomal instability. AIMS GENETICS 2021. [DOI: 10.3934/genet.2015.1.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
AbstractChromosomal instability (CIN) is a common feature of tumours that leads to increased genetic diversity in the tumour and poor clinical outcomes. There is considerable interest in understanding how CIN comes about and how its contribution to drug resistance and metastasis might be counteracted. In the last decade a number of CIN model systems have been developed in Drosophila that offer unique benefits both in understanding the development of CIN in a live animal as well as giving the potential to do genome wide screens for therapeutic candidate genes. This review outlines the mechanisms used in several Drosophila CIN model systems and summarizes some significant outcomes and opportunities that they have produced.
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Affiliation(s)
- Dawei Liu
- School of Molecular and Biomedical Science, University of Adelaide, North Terrace, Adelaide S.A. 5006, Australia
| | - Zeeshan Shaukat
- School of Molecular and Biomedical Science, University of Adelaide, North Terrace, Adelaide S.A. 5006, Australia
| | - Rashid Hussain
- School of Molecular and Biomedical Science, University of Adelaide, North Terrace, Adelaide S.A. 5006, Australia
| | - Mahwish Khan
- School of Molecular and Biomedical Science, University of Adelaide, North Terrace, Adelaide S.A. 5006, Australia
| | - Stephen L. Gregory
- School of Molecular and Biomedical Science, University of Adelaide, North Terrace, Adelaide S.A. 5006, Australia
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4
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Jilderda LJ, Zhou L, Foijer F. Understanding How Genetic Mutations Collaborate with Genomic Instability in Cancer. Cells 2021; 10:342. [PMID: 33562057 PMCID: PMC7914657 DOI: 10.3390/cells10020342] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 01/25/2021] [Accepted: 02/03/2021] [Indexed: 01/23/2023] Open
Abstract
Chromosomal instability is the process of mis-segregation for ongoing chromosomes, which leads to cells with an abnormal number of chromosomes, also known as an aneuploid state. Induced aneuploidy is detrimental during development and in primary cells but aneuploidy is also a hallmark of cancer cells. It is therefore believed that premalignant cells need to overcome aneuploidy-imposed stresses to become tumorigenic. Over the past decade, some aneuploidy-tolerating pathways have been identified through small-scale screens, which suggest that aneuploidy tolerance pathways can potentially be therapeutically exploited. However, to better understand the processes that lead to aneuploidy tolerance in cancer cells, large-scale and unbiased genetic screens are needed, both in euploid and aneuploid cancer models. In this review, we describe some of the currently known aneuploidy-tolerating hits, how large-scale genome-wide screens can broaden our knowledge on aneuploidy specific cancer driver genes, and how we can exploit the outcomes of these screens to improve future cancer therapy.
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Affiliation(s)
| | | | - Floris Foijer
- European Research Institute for the Biology of Ageing (ERIBA), University of Groningen, University Medical Centre Groningen, 9713 AV Groningen, The Netherlands; (L.J.J.); (L.Z.)
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Zhou L, Jilderda LJ, Foijer F. Exploiting aneuploidy-imposed stresses and coping mechanisms to battle cancer. Open Biol 2020; 10:200148. [PMID: 32873156 PMCID: PMC7536071 DOI: 10.1098/rsob.200148] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 07/30/2020] [Indexed: 02/06/2023] Open
Abstract
Aneuploidy, an irregular number of chromosomes in cells, is a hallmark feature of cancer. Aneuploidy results from chromosomal instability (CIN) and occurs in almost 90% of all tumours. While many cancers display an ongoing CIN phenotype, cells can also be aneuploid without displaying CIN. CIN drives tumour evolution as ongoing chromosomal missegregation will yield a progeny of cells with variable aneuploid karyotypes. The resulting aneuploidy is initially toxic to cells because it leads to proteotoxic and metabolic stress, cell cycle arrest, cell death, immune cell activation and further genomic instability. In order to overcome these aneuploidy-imposed stresses and adopt a malignant fate, aneuploid cancer cells must develop aneuploidy-tolerating mechanisms to cope with CIN. Aneuploidy-coping mechanisms can thus be considered as promising therapeutic targets. However, before such therapies can make it into the clinic, we first need to better understand the molecular mechanisms that are activated upon aneuploidization and the coping mechanisms that are selected for in aneuploid cancer cells. In this review, we discuss the key biological responses to aneuploidization, some of the recently uncovered aneuploidy-coping mechanisms and some strategies to exploit these in cancer therapy.
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Affiliation(s)
| | | | - Floris Foijer
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, 9713 AV, Groningen, The Netherlands
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Khan M, Shaukat Z, Saint R, Gregory SL. Chromosomal instability causes sensitivity to protein folding stress and ATP depletion. Biol Open 2018; 7:7/10/bio038000. [PMID: 30327366 PMCID: PMC6215417 DOI: 10.1242/bio.038000] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Aneuploidy – having an unbalanced genome – is poorly tolerated at the cellular and organismal level. It gives rise to proteotoxic stress as well as a stereotypical oxidative shift which makes these cells sensitive to internal and environmental stresses. Using Drosophila as a model, we found that protein folding stress is exacerbated by redox stress that occurs in response to ongoing changes to ploidy (chromosomal instability, CIN). We also found that if de novo nucleotide synthesis is blocked, CIN cells are dependent on a high level of lysosome function to survive. Depletion of adenosine monophosphate (AMP) synthesis enzymes led to DNA damage in CIN cells, which showed elevated activity of the DNA repair enzyme activated poly(ADP ribose) polymerase (PARP). PARP activation causes depletion of its substrate, nicotinamide adenine dinucleotide (NAD+) and subsequent loss of Adenosine Tri-Phosphate (ATP), and we found that adding ATP or nicotinamide (a precursor in the synthesis of NAD+) could rescue the observed phenotypes. These findings provide ways to interpret, target and exploit aneuploidy, which has the potential to offer tumour-specific therapies. Summary: Cells that gain or lose chromosomes during cell division are shown to be sensitive to ATP levels and protein folding stress.
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Affiliation(s)
- Mahwish Khan
- Department of Genetics, University of Adelaide, Adelaide 5006, Australia
| | - Zeeshan Shaukat
- Department of Genetics, University of Adelaide, Adelaide 5006, Australia
| | - Robert Saint
- College of Medicine and Public Health, Flinders University, Adelaide 5042, Australia
| | - Stephen L Gregory
- Department of Genetics, University of Adelaide, Adelaide 5006, Australia .,College of Medicine and Public Health, Flinders University, Adelaide 5042, Australia
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7
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Liu D, Shaukat Z, Xu T, Denton D, Saint R, Gregory S. Autophagy regulates the survival of cells with chromosomal instability. Oncotarget 2018; 7:63913-63923. [PMID: 27590505 PMCID: PMC5325413 DOI: 10.18632/oncotarget.11736] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 08/21/2016] [Indexed: 01/05/2023] Open
Abstract
Chromosomal instability (CIN) refers to genomic instability in which cells have gained or lost chromosomes or chromosomal fragments. A high level of CIN is common in solid tumours and is associated with cancer drug resistance and poor prognosis. The impact of CIN-induced stress and the resulting cellular responses are only just beginning to emerge. Using proliferating tissue in Drosophila as a model, we found that autophagy is activated in CIN cells and is necessary for their survival. Specifically, increasing the removal of defective mitochondria by mitophagy is able to lower levels of reactive oxygen species and the resultant cellular damage that is normally seen in CIN cells. In response to DNA damage, CIN is increased in a positive feedback loop, and we found that increasing autophagy by Tor depletion could decrease the level of CIN in proliferating cells. These findings underline the importance of autophagy control in the development of CIN tumours.
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Affiliation(s)
- Dawei Liu
- Department of Genetics, University of Adelaide, Adelaide, SA, Australia
| | - Zeeshan Shaukat
- Department of Genetics, University of Adelaide, Adelaide, SA, Australia
| | - Tianqi Xu
- Centre for Cancer Biology, University of South Australia, Adelaide, SA, Australia
| | - Donna Denton
- Centre for Cancer Biology, University of South Australia, Adelaide, SA, Australia
| | | | - Stephen Gregory
- Department of Genetics, University of Adelaide, Adelaide, SA, Australia
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8
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Hussain R, Shaukat Z, Khan M, Saint R, Gregory SL. Phosphoenolpyruvate Carboxykinase Maintains Glycolysis-driven Growth in Drosophila Tumors. Sci Rep 2017; 7:11531. [PMID: 28912546 PMCID: PMC5599506 DOI: 10.1038/s41598-017-11613-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/25/2017] [Indexed: 12/27/2022] Open
Abstract
Tumors frequently fail to pass on all their chromosomes correctly during cell division, and this chromosomal instability (CIN) causes irregular aneuploidy and oxidative stress in cancer cells. Our objective was to test knockdowns of metabolic enzymes in Drosophila to find interventions that could exploit the differences between normal and CIN cells to block CIN tumor growth without harming the host animal. We found that depleting by RNAi or feeding the host inhibitors against phosphoenolpyruvate carboxykinase (PEPCK) was able to block the growth of CIN tissue in a brat tumor explant model. Increasing NAD+ or oxidising cytoplasmic NADH was able to rescue the growth of PEPCK depleted tumors, suggesting a problem in clearing cytoplasmic NADH. Consistent with this, blocking the glycerol-3-phosphate shuttle blocked tumor growth, as well as lowering ROS levels. This work suggests that proliferating CIN cells are particularly vulnerable to inhibition of PEPCK, or its metabolic network, because of their compromised redox status.
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Affiliation(s)
- Rashid Hussain
- Department of Genetics and Evolution, University of Adelaide, Adelaide, 5006, Australia
| | - Zeeshan Shaukat
- Department of Genetics and Evolution, University of Adelaide, Adelaide, 5006, Australia
| | - Mahwish Khan
- Department of Genetics and Evolution, University of Adelaide, Adelaide, 5006, Australia
| | | | - Stephen L Gregory
- Department of Genetics and Evolution, University of Adelaide, Adelaide, 5006, Australia.
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9
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Poulton JS, Cuningham JC, Peifer M. Centrosome and spindle assembly checkpoint loss leads to neural apoptosis and reduced brain size. J Cell Biol 2017; 216:1255-1265. [PMID: 28351851 PMCID: PMC5412557 DOI: 10.1083/jcb.201607022] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 01/05/2017] [Accepted: 02/13/2017] [Indexed: 01/14/2023] Open
Abstract
Accurate mitotic spindle assembly is critical for mitotic fidelity and organismal development. Multiple processes coordinate spindle assembly and chromosome segregation. Two key components are centrosomes and the spindle assembly checkpoint (SAC), and mutations affecting either can cause human microcephaly. In vivo studies in Drosophila melanogaster found that loss of either component alone is well tolerated in the developing brain, in contrast to epithelial tissues of the imaginal discs. In this study, we reveal that one reason for that tolerance is the compensatory relationship between centrosomes and the SAC. In the absence of both centrosomes and the SAC, brain cells, including neural stem cells, experience massive errors in mitosis, leading to increased cell death, which reduces the neural progenitor pool and severely disrupts brain development. However, our data also demonstrate that neural cells are much more tolerant of aneuploidy than epithelial cells. Our data provide novel insights into the mechanisms by which different tissues manage genome stability and parallels with human microcephaly.
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Affiliation(s)
- John S Poulton
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 .,Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - John C Cuningham
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Mark Peifer
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 .,Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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10
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Liu D, Shaukat Z, Saint RB, Gregory SL. Chromosomal instability triggers cell death via local signalling through the innate immune receptor Toll. Oncotarget 2016; 6:38552-65. [PMID: 26462024 PMCID: PMC4770720 DOI: 10.18632/oncotarget.6035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 09/08/2015] [Indexed: 01/29/2023] Open
Abstract
Chromosomal instability (CIN) is a hallmark of cancer and has been implicated in cancer initiation, progression and the development of resistance to traditional cancer therapy. Here we identify a new property of CIN cells, showing that inducing CIN in proliferating Drosophila larval tissue leads to the activation of innate immune signalling in CIN cells. Manipulation of this immune pathway strongly affects the survival of CIN cells, primarily via JNK, which responds to both Toll and TNFα/Eiger. This pathway also activates Mmp1, which recruits hemocytes to the CIN tissue to provide local amplification of the immune response that is needed for effective elimination of CIN cells.
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Affiliation(s)
- Dawei Liu
- School of Biological Sciences, University of Adelaide, Adelaide, Australia
| | - Zeeshan Shaukat
- School of Biological Sciences, University of Adelaide, Adelaide, Australia
| | - Robert B Saint
- School of Biological Sciences, University of Adelaide, Adelaide, Australia
| | - Stephen L Gregory
- School of Biological Sciences, University of Adelaide, Adelaide, Australia
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11
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Rao CV, Asch AS, Yamada HY. Emerging links among Chromosome Instability (CIN), cancer, and aging. Mol Carcinog 2016; 56:791-803. [PMID: 27533343 DOI: 10.1002/mc.22539] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 07/14/2016] [Accepted: 08/15/2016] [Indexed: 12/15/2022]
Abstract
Aneuploidy was predicted to cause cancer. To test the prediction, various Chromosome Instability (CIN) mice models that carry transgenic mutations in mitotic regulators have been created. The availability of these mice has aided researchers in discovering connections between CIN, cancer, and aging. This review will focus on recent interdisciplinary findings regarding how CIN and aneuploidy affect carcinogenesis, immune dysfunction, and aging. High CIN can be generated in vivo by various intrinsic alterations (e.g., gene mutation, epigenetic modification) and extrinsic/environmental challenges (e.g., biological, chemical, biophysical), while immune surveillance, cell death, and natural turnover can remove cells with CIN. CIN itself is mutagenic and may cause further cellular mutations, which can be carcinogenic. Mitotically damaged cells can activate senescence-related tumor suppressors (e.g., p21WAF1 , p27KIP1 , p16INK4A ), which may lead to tissue-level senescence/aging through inflammatory paracrine mechanisms called Senescence-Associated Secretory Phenotype (SASP) and Senescence Inflammatory Response (SIR). Organs with high CIN show altered gene expressions in both organ-specific and non-specific manners. Organ-specific gene expression signatures include activation of oncogenic pathways. Non-organ-specific gene expression signatures include metabolic changes and downregulations in immune functions. Immune surveillance normally targets senescent cells and tetraploid cells, a form of aneuploidy, for elimination. However, with partial immune dysfunction, immune surveillance is weakened with systemic CIN. In this case, more senescent cells and aneuploid cells survive, which further leads to an inflammatory, pro-tumorigenic, and senescent/aging microenvironment. We also discuss how we may intervene in this sequence of events to prevent CIN- or age-related carcinogenesis and/or some aspects of tissue aging. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Chinthalapally V Rao
- Department of Medicine, Center for Cancer Prevention and Drug Development, Hematology/Oncology Section, University of Oklahoma Health Sciences Center (OUHSC), Oklahoma City, Oklahoma.,Stephenson Cancer Center, Hematology/Oncology, University of Oklahoma, Oklahoma City, Oklahoma
| | - Adam S Asch
- Stephenson Cancer Center, Hematology/Oncology, University of Oklahoma, Oklahoma City, Oklahoma
| | - Hiroshi Y Yamada
- Department of Medicine, Center for Cancer Prevention and Drug Development, Hematology/Oncology Section, University of Oklahoma Health Sciences Center (OUHSC), Oklahoma City, Oklahoma.,Stephenson Cancer Center, Hematology/Oncology, University of Oklahoma, Oklahoma City, Oklahoma
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12
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Sterile inflammation in Drosophila. Mediators Inflamm 2015; 2015:369286. [PMID: 25948885 PMCID: PMC4408615 DOI: 10.1155/2015/369286] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/27/2015] [Accepted: 03/27/2015] [Indexed: 12/18/2022] Open
Abstract
The study of immune responses in Drosophila has already yielded significant results with impacts on our understanding of vertebrate immunity, such as the characterization of the Toll receptor. Several recent papers have focused on the humoral response to damage signals rather than pathogens, particularly damage signals from tumour-like tissues generated by loss of cell polarity or chromosomal instability. Both the triggers that generate this sterile inflammation and the systemic and local effects of it are only just beginning to be characterized in Drosophila. Here we review the molecular mechanisms that are known that give rise to the recruitment of Drosophila phagocytes, called hemocytes, as well as the signals, such as TNFα, that stimulated hemocytes emit at sites of perceived damage. The signalling consequences of inflammation, such as the activation of JNK, and the potential for modifying this response are also discussed.
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13
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Chromosomal instability causes sensitivity to metabolic stress. Oncogene 2014; 34:4044-55. [PMID: 25347746 DOI: 10.1038/onc.2014.344] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 08/31/2014] [Accepted: 09/15/2014] [Indexed: 02/07/2023]
Abstract
Chromosomal INstability (CIN), a hallmark of cancer, refers to cells with an increased rate of gain or loss of whole chromosomes or chromosome parts. CIN is linked to the progression of tumors with poor clinical outcomes such as drug resistance. CIN can give tumors the diversity to resist therapy, but it comes at the cost of significant stress to tumor cells. To tolerate this, cancer cells must modify their energy use to provide adaptation against genetic changes as well as to promote their survival and growth. In this study, we have demonstrated that CIN induction causes sensitivity to metabolic stress. We show that mild metabolic disruption that does not affect normal cells, can lead to high levels of oxidative stress and subsequent cell death in CIN cells because they are already managing elevated stress levels. Altered metabolism is a differential characteristic of cancer cells, so our identification of key regulators that can exploit these changes to cause cell death may provide cancer-specific potential drug targets, especially for advanced cancers that exhibit CIN.
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14
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Neuronal necrosis is regulated by a conserved chromatin-modifying cascade. Proc Natl Acad Sci U S A 2014; 111:13960-5. [PMID: 25201987 DOI: 10.1073/pnas.1413644111] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Neuronal necrosis induced by calcium overload causes devastating brain dysfunction in diseases such as stroke and brain trauma. It has been considered a stochastic event lacking genetic regulation, and pharmacological means to suppress neuronal necrosis are lacking. Using a Drosophila model of calcium overloading, we found JIL-1/mitogen- and stress-activated protein kinase 1/2 is a regulator of neuronal necrosis through phosphorylation of histone H3 serine 28 (H3S28ph). Further, we identified its downstream events including displacement of polycomb repressive complex 1 (PRC1) and activation of Trithorax (Trx). To test the role of JIL-1/PRC1/Trx cascade in mammals, we studied the necrosis induced by glutamate in rat cortical neuron cultures and rodent models of brain ischemia and found the cascade is activated in these conditions and inhibition of the cascade suppresses necrosis in vitro and in vivo. Together, our research demonstrates that neuronal necrosis is regulated by a chromatin-modifying cascade, and this discovery may provide potential therapeutic targets and biomarkers for neuronal necrosis.
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Wong HWS, Shaukat Z, Wang J, Saint R, Gregory SL. JNK signaling is needed to tolerate chromosomal instability. Cell Cycle 2013; 13:622-31. [PMID: 24335260 DOI: 10.4161/cc.27484] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Chromosomal instability (CIN), as a common feature of tumors, represents a potential therapeutic target if ways can be found to specifically cause apoptosis in unstably dividing cells. We have previously shown that if signaling through the JNK pathway is reduced, apoptosis is triggered in models of chromosomal instability induced by loss of the spindle checkpoint. Here we identify components upstream and downstream of JNK that are able to mediate this effect, and test the involvement of p53 and DNA damage in causing apoptosis when JNK signaling is reduced in CIN cells. We show that cell cycle progression timing has a strong effect on the apoptosis seen when JNK signaling is reduced in genetically unstable cells: a shortened G 2 phase enhances the apoptosis, while lengthening G 2 rescues the JNK-deficient CIN cell death phenotype. Our findings suggest that chromosomal instability represents a significant stress to dividing cells, and that without JNK signaling, cells undergo apoptosis because they lack a timely and effective response to DNA damage.
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Affiliation(s)
- Heidi W-S Wong
- Department of Genetics; University of Melbourne; Melbourne, VIC, Australia
| | - Zeeshan Shaukat
- School of Molecular and Biomedical Sciences; University of Adelaide; Adelaide, SA, Australia
| | - Jianbin Wang
- Department of Genetics; University of Melbourne; Melbourne, VIC, Australia
| | - Robert Saint
- Department of Genetics; University of Melbourne; Melbourne, VIC, Australia; School of Molecular and Biomedical Sciences; University of Adelaide; Adelaide, SA, Australia
| | - Stephen L Gregory
- School of Molecular and Biomedical Sciences; University of Adelaide; Adelaide, SA, Australia
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16
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Cappello P, Blaser H, Gorrini C, Lin DCC, Elia AJ, Wakeham A, Haider S, Boutros PC, Mason JM, Miller NA, Youngson B, Done SJ, Mak TW. Role of Nek2 on centrosome duplication and aneuploidy in breast cancer cells. Oncogene 2013; 33:2375-84. [PMID: 23708664 DOI: 10.1038/onc.2013.183] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 04/04/2013] [Accepted: 04/04/2013] [Indexed: 11/09/2022]
Abstract
Breast cancer is the most common solid tumor and the second most common cause of death in women. Despite a large body of literature and progress in breast cancer research, many molecular aspects of this complex disease are still poorly understood, hindering the design of specific and effective therapeutic strategies. To identify the molecules important in breast cancer progression and metastasis, we tested the in vivo effects of inhibiting the functions of various kinases and genes involved in the regulation/modulation of the cytoskeleton by downregulating them in mouse PyMT mammary tumor cells and human breast cancer cell lines. These kinases and cytoskeletal regulators were selected based on their prognostic values for breast cancer patient survival. PyMT tumor cells, in which a selected gene was stably knocked down were injected into the tail veins of mice, and the formation of tumors in the lungs was monitored. One of the several genes found to be important for tumor growth in the lungs was NIMA-related kinases 2 (Nek2), a cell cycle-related protein kinase. Furthermore, Nek2 was also important for tumor growth in the mammary fat pad. In various human breast cancer cell lines, Nek2 knockdown induced aneuploidy and cell cycle arrest that led to cell death. Significantly, the breast cancer cell line most sensitive to Nek2 depletion was of the triple negative breast cancer subtype. Our data indicate that Nek2 has a pivotal role in breast cancer growth at primary and secondary sites, and thus may be an attractive and novel therapeutic target for this disease.
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Affiliation(s)
- P Cappello
- 1] The Campbell Family Institute for Breast Cancer Research, University Health Network, Toronto, Ontario, Canada [2] Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - H Blaser
- The Campbell Family Institute for Breast Cancer Research, University Health Network, Toronto, Ontario, Canada
| | - C Gorrini
- The Campbell Family Institute for Breast Cancer Research, University Health Network, Toronto, Ontario, Canada
| | - D C C Lin
- The Campbell Family Institute for Breast Cancer Research, University Health Network, TMDT East Tower, MaRS Centre, Toronto, Ontario, Canada
| | - A J Elia
- The Campbell Family Institute for Breast Cancer Research, University Health Network, Toronto, Ontario, Canada
| | - A Wakeham
- The Campbell Family Institute for Breast Cancer Research, University Health Network, Toronto, Ontario, Canada
| | - S Haider
- Informatics and Biocomputing Platform, Ontario Institute for Cancer Research, Toronto, Ontario, Canada
| | - P C Boutros
- Informatics and Biocomputing Platform, Ontario Institute for Cancer Research, Toronto, Ontario, Canada
| | - J M Mason
- The Campbell Family Institute for Breast Cancer Research, University Health Network, TMDT East Tower, MaRS Centre, Toronto, Ontario, Canada
| | - N A Miller
- 1] Laboratory Medicine Program, University Health Network, Toronto, Ontario, Canada [2] Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - B Youngson
- 1] Laboratory Medicine Program, University Health Network, Toronto, Ontario, Canada [2] Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - S J Done
- 1] The Campbell Family Institute for Breast Cancer Research, University Health Network, Toronto, Ontario, Canada [2] Laboratory Medicine Program, University Health Network, Toronto, Ontario, Canada [3] Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - T W Mak
- The Campbell Family Institute for Breast Cancer Research, University Health Network, Toronto, Ontario, Canada
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