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Pangeni RP, Olivaries I, Huen D, Buzatto VC, Dawson TP, Ashton KM, Davis C, Brodbelt AR, Jenkinson MD, Bièche I, Yang L, Latif F, Darling JL, Warr TJ, Morris MR. Genome-wide methylation analyses identifies Non-coding RNA genes dysregulated in breast tumours that metastasise to the brain. Sci Rep 2022; 12:1102. [PMID: 35058523 PMCID: PMC8776809 DOI: 10.1038/s41598-022-05050-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 12/08/2021] [Indexed: 02/06/2023] Open
Abstract
Brain metastases comprise 40% of all metastatic tumours and breast tumours are among the tumours that most commonly metastasise to the brain, the role that epigenetic gene dysregulation plays in this process is not well understood. We carried out 450 K methylation array analysis to investigate epigenetically dysregulated genes in breast to brain metastases (BBM) compared to normal breast tissues (BN) and primary breast tumours (BP). For this, we referenced 450 K methylation data for BBM tumours prepared in our laboratory with BN and BP from The Cancer Genome Atlas. Experimental validation on our initially identified genes, in an independent cohort of BP and in BBM and their originating primary breast tumours using Combined Bisulphite and Restriction Analysis (CoBRA) and Methylation Specific PCR identified three genes (RP11-713P17.4, MIR124-2, NUS1P3) that are hypermethylated and three genes (MIR3193, CTD-2023M8.1 and MTND6P4) that are hypomethylated in breast to brain metastases. In addition, methylation differences in candidate genes between BBM tumours and originating primary tumours shows dysregulation of DNA methylation occurs either at an early stage of tumour evolution (in the primary tumour) or at a later evolutionary stage (where the epigenetic change is only observed in the brain metastasis). Epigentic changes identified could also be found when analysing tumour free circulating DNA (tfcDNA) in patient’s serum taken during BBM biopsies. Epigenetic dysregulation of RP11-713P17.4, MIR3193, MTND6P4 are early events suggesting a potential use for these genes as prognostic markers.
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Olivares I, Pangeni RP, Huen D, Dawson TP, Ashton K, Davis C, Jenkinson MD, Brodbelt AR, Wang W, Darling JL, Warr TJ, Morris MR. Identifying epigenetic changes in breast tumours that metastasise to the brain. Eur J Surg Oncol 2018. [DOI: 10.1016/j.ejso.2018.01.567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Pangeni RP, Channathodiyil P, Huen DS, Eagles LW, Johal BK, Pasha D, Hadjistephanou N, Nevell O, Davies CL, Adewumi AI, Khanom H, Samra IS, Buzatto VC, Chandrasekaran P, Shinawi T, Dawson TP, Ashton KM, Davis C, Brodbelt AR, Jenkinson MD, Bièche I, Latif F, Darling JL, Warr TJ, Morris MR. The GALNT9, BNC1 and CCDC8 genes are frequently epigenetically dysregulated in breast tumours that metastasise to the brain. Clin Epigenetics 2015; 7:57. [PMID: 26052355 PMCID: PMC4457099 DOI: 10.1186/s13148-015-0089-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [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: 12/16/2014] [Accepted: 05/11/2015] [Indexed: 01/12/2023] Open
Abstract
Background Tumour metastasis to the brain is a common and deadly development in certain cancers; 18–30 % of breast tumours metastasise to the brain. The contribution that gene silencing through epigenetic mechanisms plays in these metastatic tumours is not well understood. Results We have carried out a bioinformatic screen of genome-wide breast tumour methylation data available at The Cancer Genome Atlas (TCGA) and a broad literature review to identify candidate genes that may contribute to breast to brain metastasis (BBM). This analysis identified 82 candidates. We investigated the methylation status of these genes using Combined Bisulfite and Restriction Analysis (CoBRA) and identified 21 genes frequently methylated in BBM. We have identified three genes, GALNT9, CCDC8 and BNC1, that were frequently methylated (55, 73 and 71 %, respectively) and silenced in BBM and infrequently methylated in primary breast tumours. CCDC8 was commonly methylated in brain metastases and their associated primary tumours whereas GALNT9 and BNC1 were methylated and silenced only in brain metastases, but not in the associated primary breast tumours from individual patients. This suggests differing roles for these genes in the evolution of metastatic tumours; CCDC8 methylation occurs at an early stage of metastatic evolution whereas methylation of GANLT9 and BNC1 occurs at a later stage of tumour evolution. Knockdown of these genes by RNAi resulted in a significant increase in the migratory and invasive potential of breast cancer cell lines. Conclusions These findings indicate that GALNT9 (an initiator of O-glycosylation), CCDC8 (a regulator of microtubule dynamics) and BNC1 (a transcription factor with a broad range of targets) may play a role in the progression of primary breast tumours to brain metastases. These genes may be useful as prognostic markers and their products may provide novel therapeutic targets. Electronic supplementary material The online version of this article (doi:10.1186/s13148-015-0089-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rajendra P Pangeni
- Brain Tumour Research Centre, University of Wolverhampton, Wolverhampton, UK
| | | | - David S Huen
- School of Biology, Chemistry and Forensic Sciences, University of Wolverhampton, Wolverhampton, UK
| | - Lawrence W Eagles
- Brain Tumour Research Centre, University of Wolverhampton, Wolverhampton, UK
| | - Balraj K Johal
- School of Biology, Chemistry and Forensic Sciences, University of Wolverhampton, Wolverhampton, UK
| | - Dawar Pasha
- School of Biology, Chemistry and Forensic Sciences, University of Wolverhampton, Wolverhampton, UK
| | - Natasa Hadjistephanou
- School of Biology, Chemistry and Forensic Sciences, University of Wolverhampton, Wolverhampton, UK
| | - Oliver Nevell
- School of Biology, Chemistry and Forensic Sciences, University of Wolverhampton, Wolverhampton, UK
| | - Claire L Davies
- School of Biology, Chemistry and Forensic Sciences, University of Wolverhampton, Wolverhampton, UK
| | - Ayobami I Adewumi
- School of Biology, Chemistry and Forensic Sciences, University of Wolverhampton, Wolverhampton, UK
| | - Hamida Khanom
- School of Biology, Chemistry and Forensic Sciences, University of Wolverhampton, Wolverhampton, UK
| | - Ikroop S Samra
- School of Biology, Chemistry and Forensic Sciences, University of Wolverhampton, Wolverhampton, UK
| | - Vanessa C Buzatto
- School of Biology, Chemistry and Forensic Sciences, University of Wolverhampton, Wolverhampton, UK
| | - Preethi Chandrasekaran
- School of Biology, Chemistry and Forensic Sciences, University of Wolverhampton, Wolverhampton, UK
| | - Thoraia Shinawi
- Centre for Rare Diseases and Personalised Medicine, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, UK
| | - Timothy P Dawson
- Department of Neurosciences, Lancashire Teaching Hospitals NHS Foundation Trust, Royal Preston Hospital, Fulwood, Preston, UK
| | - Katherine M Ashton
- Department of Neurosciences, Lancashire Teaching Hospitals NHS Foundation Trust, Royal Preston Hospital, Fulwood, Preston, UK
| | - Charles Davis
- Department of Neurosciences, Lancashire Teaching Hospitals NHS Foundation Trust, Royal Preston Hospital, Fulwood, Preston, UK
| | | | | | - Ivan Bièche
- Department of Genetics, Institute Curie, Paris, France
| | - Farida Latif
- Centre for Rare Diseases and Personalised Medicine, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, UK
| | - John L Darling
- Brain Tumour Research Centre, University of Wolverhampton, Wolverhampton, UK
| | - Tracy J Warr
- Brain Tumour Research Centre, University of Wolverhampton, Wolverhampton, UK
| | - Mark R Morris
- Brain Tumour Research Centre, University of Wolverhampton, Wolverhampton, UK ; School of Biology, Chemistry and Forensic Sciences, University of Wolverhampton, Wolverhampton, UK ; Centre for Rare Diseases and Personalised Medicine, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, UK
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Karakoula K, Jacques TS, Phipps KP, Harkness W, Thompson D, Harding BN, Darling JL, Warr TJ. Epigenetic genome-wide analysis identifies BEX1 as a candidate tumour suppressor gene in paediatric intracranial ependymoma. Cancer Lett 2013; 346:34-44. [PMID: 24333734 DOI: 10.1016/j.canlet.2013.12.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [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: 07/30/2013] [Revised: 12/02/2013] [Accepted: 12/04/2013] [Indexed: 12/13/2022]
Abstract
Promoter hypermethylation and transcriptional silencing is a common epigenetic mechanism of gene inactivation in cancer. To identify targets of epigenetic silencing in paediatric intracranial ependymoma, we used a pharmacological unmasking approach through treatment of 3 ependymoma short-term cell cultures with the demethylating agent 5-Aza-2'-deoxycytidine followed by global expression microarray analysis. We identified 55 candidate epigenetically silenced genes, which are involved in the regulation of apoptosis, Wnt signalling, p53 and cell differentiation. The methylation status of 26 of these genes was further determined by combined bisulfite restriction analysis (COBRA) and genomic sequencing in a cohort of 40 ependymoma samples. The most frequently methylated genes were BEX1 (27/40 cases), BAI2 (20/40), CCND2 (18/40), and CDKN2A (14/40). A high correlation between promoter hypermethylation and decreased gene expression levels was established by real-time quantitative PCR, suggesting the involvement of these genes in ependymoma tumourigenesis. Furthermore, ectopic expression of brain-expressed X-linked 1 (BEX1) in paediatric ependymoma short-term cell cultures significantly suppressed cell proliferation and colony formation. These data suggest that promoter hypermethylation contributes to silencing of target genes in paediatric intracranial ependymoma. Epigenetic inactivation of BEX1 supports its role as a candidate tumour suppressor gene in intracranial ependymoma, and a potential target for novel therapies for ependymoma in children.
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Affiliation(s)
- Katherine Karakoula
- Brain Tumour Research Centre, School of Applied Sciences, University of Wolverhampton, Wolverhampton WV1 1LY, UK.
| | - Thomas S Jacques
- Neural Development Unit, Birth Defects Research Centre, UCL Institute of Child Health, University College London, London WC1E 6BT, UK; Department of Histopathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | - Kim P Phipps
- Department of Neurosurgery, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | - William Harkness
- Department of Neurosurgery, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | - Dominic Thompson
- Department of Neurosurgery, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | - Brian N Harding
- Division of Neuropathology, Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104-4399, USA
| | - John L Darling
- Brain Tumour Research Centre, School of Applied Sciences, University of Wolverhampton, Wolverhampton WV1 1LY, UK
| | - Tracy J Warr
- Brain Tumour Research Centre, School of Applied Sciences, University of Wolverhampton, Wolverhampton WV1 1LY, UK
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Lehnus KS, Donovan LK, Huang X, Zhao N, Warr TJ, Pilkington GJ, An Q. CD133 glycosylation is enhanced by hypoxia in cultured glioma stem cells. Int J Oncol 2013; 42:1011-7. [PMID: 23340741 DOI: 10.3892/ijo.2013.1787] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 10/17/2012] [Indexed: 11/06/2022] Open
Abstract
The cancer stem cell (CSC) marker CD133 is widely expressed in gliomas and employed mostly by use of the CD133/1 antibody which binds the extracellular glycosylated AC133 epitope. CD133 recognition may, however, be affected by its glycosylation pattern and oxygen tension. The present study investigates the effect of oxygen deprivation on CD133 expression and glycosylation status employing a high AC133-expressing glioblastoma multiforme (GBM) cell line, IN699. IN699 cells were cultured under normoxic (21% O2) and hypoxic (3% O2) conditions. CD133 expression was analysed by western blotting (WB), qRT-PCR, immunocytochemistry (ICC) and flow cytometry using the glycosylation-specific antibody CD133/1 and ab19898 which binds the unglycosylated intra-cellular residues of CD133. By flow cytometry, ab19898 detected 94.1% and 96.2% CD133+ cells under normoxia and hypoxia, respectively. Hypoxia significantly increased the percentage of CD133+ cells from 69% to 92% using CD133/1 (p<0.005). Moreover, a significantly higher geomean fluorescence intensity (GMI) was demonstrated by ab19898 (p<0.005) in CD133+ cells. WB and qRT-PCR results were consistent with flow cytometry data. Furthermore, over a period of 72-h incubation under normoxic and hypoxic conditions after autoMACS sorting, an average of 31.8% and 42.2%, respectively, of CD133-negative IN699 cells became positive using CD133/1. Our data show that a) previously reported CD133- cells may have been misidentified using the glycosylation-specific CD133/1 as constitutive expression of CD133 was detected by the intracellular antibody ab19898; b) hypoxia promotes glycosylation status of CD133, indicating possible involvement of glycosylated CD133 in the process of anti-hypoxia-mediated apoptosis.
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Affiliation(s)
- Kristina S Lehnus
- Cellular and Molecular Neuro-Oncology Research Group, Institute of Biomedical and Biomolecular Science, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK
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Ward SJ, Karakoula K, Phipps KP, Harkness W, Hayward R, Thompson D, Jacques TS, Harding B, Darling JL, Thomas DGT, Warr TJ. Cytogenetic analysis of paediatric astrocytoma using comparative genomic hybridisation and fluorescence in-situ hybridisation. J Neurooncol 2010; 98:305-18. [DOI: 10.1007/s11060-009-0081-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2009] [Accepted: 11/30/2009] [Indexed: 11/29/2022]
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Karakoula K, Suarez-Merino B, Ward S, Phipps KP, Harkness W, Hayward R, Thompson D, Jacques TS, Harding B, Beck J, Thomas DGT, Warr TJ. Real-time quantitative PCR analysis of pediatric ependymomas identifies novel candidate genes including TPR at 1q25 and CHIBBY at 22q12-q13. Genes Chromosomes Cancer 2008; 47:1005-22. [PMID: 18663750 DOI: 10.1002/gcc.20607] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Loss of chromosome 22 and gain of 1q are the most frequent genomic aberrations in ependymomas, indicating that genes mapping to these regions are critical in their pathogenesis. Using real-time quantitative PCR, we measured relative copy numbers of 10 genes mapping to 22q12.3-q13.33 and 10 genes at 1q21-32 in a series of 47 pediatric intracranial ependymomas. Loss of one or more of the genes on 22 was detected in 81% of cases, with RAC2 and C22ORF2 at 22q12-q13.1 being deleted most frequently in 38% and 32% of ependymoma samples, respectively. Combined analysis of quantitative-PCR with methylation-specific PCR and bisulphite sequencing revealed a high rate (>60% ependymoma) of transcriptional inactivation of C22ORF2, indicating its potential importance in the development of pediatric ependymomas. Increase of relative copy numbers of at least one gene on 1q were detected in 61% of cases, with TPR at 1q25 displaying relative copy number gains in 38% of cases. Patient age was identified as a significant adverse prognostic factor, as a significantly shorter overall survival time (P = 0.0056) was observed in patients <2 years of age compared with patients who were >2 years of age. Loss of RAC2 at 22q13 or amplification of TPR at 1q25 was significantly associated with shorter overall survival in these younger patients (P = 0.0492 and P = < 0.0001, respectively). This study identifies candidate target genes within 1q and 22q that are potentially important in the pathogenesis of intracranial pediatric ependymomas.
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Affiliation(s)
- Katherine Karakoula
- Department of Molecular Neuroscience, Institute of Neurology, University College London, National Hospital for Neurology and Neurosurgery, London, UK
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Suarez-Merino B, Hubank M, Revesz T, Harkness W, Hayward R, Thompson D, Darling JL, Thomas DGT, Warr TJ. Microarray analysis of pediatric ependymoma identifies a cluster of 112 candidate genes including four transcripts at 22q12.1-q13.3. Neuro Oncol 2005. [PMID: 15701279 DOI: 10.1215/s1152851704000596] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Ependymomas are glial cell-derived tumors characterized by varying degrees of chromosomal abnormalities and variability in clinical behavior. Cytogenetic analysis of pediatric ependymoma has failed to identify consistent patterns of abnormalities, with the exception of monosomy of 22 or structural abnormalities of 22q. In this study, a total of 19 pediatric ependymoma samples were used in a series of expression profiling, quantitative real-time PCR (Q-PCR), and loss of heterozygosity experiments to identify candidate genes involved in the development of this type of pediatric malignancy. Of the 12,627 genes analyzed, a subset of 112 genes emerged as being abnormally expressed when compared to three normal brain controls. Genes with increased expression included the oncogene WNT5A; the p53 homologue p63; and several cell cycle, cell adhesion, and proliferation genes. Underexpressed genes comprised the NF2 interacting gene SCHIP-1 and the adenomatous polyposis coli (APC)-associated gene EB1 among others. We validated the abnormal expression of six of these genes by Q-PCR. The subset of differentially expressed genes also included four underexpressed transcripts mapping to 22q12.313.3. By Q-PCR we show that one of these genes, 7 CBX7(22q13.1), was deleted in 55% of cases. Other genes mapping to cytogenetic hot spots included two overexpressed and three underexpressed genes mapping to 1q31-41 and 6q21-q24.3, respectively. These genes represent candidate genes involved in ependymoma tumorigenesis. To the authors' knowledge, this is the first time microarray analysis and Q-PCR have been linked to identify heterozygous/homozygous deletions.
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Affiliation(s)
- Blanca Suarez-Merino
- Department of Molecular Neuroscience, Institute of Neurology, National Hospital for Neurology and Neurosurgery, University College London, London, UK
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9
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Suarez-Merino B, Hubank M, Revesz T, Harkness W, Hayward R, Thompson D, Darling JL, Thomas DG, Warr TJ. Microarray analysis of pediatric ependymoma identifies a cluster of 112 candidate genes including four transcripts at 22q12.1-q13.3. Neuro Oncol 2005; 7:20-31. [PMID: 15701279 PMCID: PMC1871622 DOI: 10.1215/s1152851704000596)] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Ependymomas are glial cell-derived tumors characterized by varying degrees of chromosomal abnormalities and variability in clinical behavior. Cytogenetic analysis of pediatric ependymoma has failed to identify consistent patterns of abnormalities, with the exception of monosomy of 22 or structural abnormalities of 22q. In this study, a total of 19 pediatric ependymoma samples were used in a series of expression profiling, quantitative real-time PCR (Q-PCR), and loss of heterozygosity experiments to identify candidate genes involved in the development of this type of pediatric malignancy. Of the 12,627 genes analyzed, a subset of 112 genes emerged as being abnormally expressed when compared to three normal brain controls. Genes with increased expression included the oncogene WNT5A; the p53 homologue p63; and several cell cycle, cell adhesion, and proliferation genes. Underexpressed genes comprised the NF2 interacting gene SCHIP-1 and the adenomatous polyposis coli (APC)-associated gene EB1 among others. We validated the abnormal expression of six of these genes by Q-PCR. The subset of differentially expressed genes also included four underexpressed transcripts mapping to 22q12.313.3. By Q-PCR we show that one of these genes, 7 CBX7(22q13.1), was deleted in 55% of cases. Other genes mapping to cytogenetic hot spots included two overexpressed and three underexpressed genes mapping to 1q31-41 and 6q21-q24.3, respectively. These genes represent candidate genes involved in ependymoma tumorigenesis. To the authors' knowledge, this is the first time microarray analysis and Q-PCR have been linked to identify heterozygous/homozygous deletions.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Tracy J. Warr
- Address correspondence to Tracy J. Warr, Department of Molecular Neuroscience, Neuro-Oncology Group, Institute of Neurology, Queen Square, London WC1N 3BG, UK (
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Abstract
Conventional therapies such as surgery, radiotherapy and, to a lesser extent, chemotherapy have produced significant increases in survival in patients with some types of brain tumours such as medulloblastoma. However, in many other types of brain tumour in both adults and children, the effect of these modalities has been more modest. A thorough understanding of the biology of malignant brain tumours is likely to provide the background for the development of new leads that might be amenable to therapeutic exploitation. This review examines some aspects of glioma biology that have been reported in the past 12 months, and which might be translated into clinical application.
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Affiliation(s)
- J L Darling
- University Department of Neurosurgery, Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, UK
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Abstract
The molecular genetic analysis of brain tumours has been the focus of considerable interest for a number of years. However, these studies have been largely directed towards understanding the fundamental biological processes involved in tumorigenesis and the techniques which have been used require considerable molecular biological skills. Unfortunately, there has not been the impetus to correlate basic biological studies with clinical or neuropathological features. The development of non-isotopic molecular cytogenetic in situ hybridization (ISH) techniques which can be applied to archival tumour material provides an opportunity to address a wide range of neuropathological questions at a genetic level. Identification of specific chromosomes has been made possible by the isolation of probes which recognize the highly repeated sequences present in the centromeric regions of individual chromosomes. Libraries of human chromosome-specific painting probes are also available. A range of probes which bind to the whole or part of specific single copy genes are becoming available. These can be detected with either fluorochromes with different emission colours or with enzymatic detection systems in either interphase nuclei derived from fresh, fixed and embedded tumour samples, touch preparations or smears (so-called 'interphase cytogenetics') as well as conventional metaphase spreads. Comparative genomic hybridization can be used to scan the entire genome for deletions or amplifications without any pre-existing information about the likely locations of these abnormalities or the availability of any specific DNA probes. These techniques can be used to identify aneuploidy or structural alterations in individual chromosomes and are likely to yield important information about the location of genes important in the pathogenesis of brain tumours and may also provide the basis for the refinement of diagnostic or prognostic criteria of these neoplasms.
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Affiliation(s)
- J L Darling
- University Department of Neurological Surgery, National Hospital for Neurology and Neurosurgery, London, UK
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Warr TJ, Parry EM, Parry JM. A comparison of two in vitro mammalian cell cytogenetic assays for the detection of mitotic aneuploidy using 10 known or suspected aneugens. Mutat Res 1993; 287:29-46. [PMID: 7683382 DOI: 10.1016/0027-5107(93)90143-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Two in vitro cytogenetic assays were evaluated for their ability to detect aneugenic and polyploidy-inducing agents using a battery of 10 known or suspected aneugens supplied as part of the EEC 4th Environmental Research and Development Programme. The compounds tested were colchicine, vinblastine, chloral hydrate, thiabendazole, hydroquinone, thimerosal, cadmium chloride, econazole nitrate, pyrimethamine and diazepam. The cell division aberration assay employed a differential chromosome/spindle staining procedure to detect perturbations of the mitotic division apparatus. This assay was carried out in two pulmonary-derived Chinese hamster cell lines; the immortal DON:Wg3h culture and a low passage LUC2 culture. The second assay involved quantification of metaphase chromosomes, for which only the LUC2 cell line was used, due to the stability of its diploid karyotype. All the chemicals induced spindle disturbances in the immortal line. In addition, all the compounds except cadmium chloride yielded positive results in the LUC2 culture, although many were not as potent. In the low passage line, 8 of the compounds (colchicine, vinblastine, chloral hydrate, thiabendazole, thimerosal, econazole nitrate, pyrimethamine and diazepam) induced aneuploidy and/or tetraploidy. Cadmium chloride was negative in the chromosome enumeration assay and hydroquinone yielded inconclusive results. The study of cell division aberrations was much less time-consuming and technically complex than the counting of metaphase chromosomes. In addition, it provided a degree of mechanistic understanding of the mode of action of some aneugenic and polyploidy-producing agents. However, the enumeration of chromosomes provides a more definitive data set for the evaluation of a chemical's aneugenic potential.
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Affiliation(s)
- T J Warr
- School of Biological Sciences, University College of Swansea, UK
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Mitchell CD, Ventris JA, Warr TJ, Cowell JK. Molecular definition in a somatic cell hybrid of a specific 2:13 translocation breakpoint in childhood rhabdomyosarcoma. Oncogene 1991; 6:89-92. [PMID: 1992447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A consistent, balanced, reciprocal chromosomal translocation t(2:13) (q35:q14) has been identified in alveolar rhabdomyosarcoma. Somatic cell hybrids have been constructed between rhabdomyosarcoma cell lines carrying the (2:13) translocation and mouse 3T3 cells. One hybrid cell line was shown to have retained the derivative (13:2) chromosome, but segregated the normal chromosome 13 and the derivative (2:13) chromosome. Using available DNA probes from human chromosome 13 we find that the loci for retinoblastoma, esterase D, p7D2, pG24E6.8 and pG14E1.9 lie distally to the 13q14 breakpoint, whereas those for p7F12, pHU10 and pG2E3.1 all lie proximally. Thus we have defined a region of 13q14 of approximately 28mB which contains the breakpoint associated with this rearrangement.
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Affiliation(s)
- C D Mitchell
- Leukemia Research Fund Department of Haematology and Oncology, Institute of Child Health, London, UK
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Abstract
Methyl vinyl sulphone (MVS) is a labile, Michael-reactive chemical, similar in structure to acrylamide (AA). Given that acrylamide is a reference mammalian mutagen and a rodent carcinogen, studies were undertaken to evaluate the potential genotoxicity of MVS. In common with AA, MVS was non-mutagenic to Salmonella but active as an aneugen to cultured mammalian cells. It is concluded that vinyl sulphones should be regarded as representative of a new class of genotoxic chemical whose mode of action is probably primarily dependent upon Michael reactivity to proteins.
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Affiliation(s)
- T J Warr
- School of Biological Sciences, University College of Swansea, Singleton Park, Great Britain
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