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Alsufyani D, Lindesay J. Evidence of cancer-linked rodent zoonoses from biophysical genomic variations. Sci Rep 2023; 13:13969. [PMID: 37634038 PMCID: PMC10460378 DOI: 10.1038/s41598-023-41257-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 08/23/2023] [Indexed: 08/28/2023] Open
Abstract
As a mechanism to explore the role of environmental adaptation in establishing the optimal distribution of single nucleotide polymophisms (SNPs) within resident homeostatic populations, relationships between quantified environmental parameters and the frequencies of the variants are being explored. We have performed sequential double-blind scans on more than 30% of chromosome 3 in an attempt to discover possible relationships using simple mathematical functions that are indicative of "adaptive forces" on the variants due to specific quantified environmental agents. We have found an association of rs13071758 with rodent zoonotic diseases. This variant is within the FHIT gene, which spans the most fragile of the common fragile sites in human lymphoblasts. FHIT, which is highly sensitive to environmental carcinogens, is partially lost in most human cancers. This finding is consistent with other studies postulating an association between rodent zoonoses and cancer. We quantify the adaptive force on the T allele as 0.28 GEUs per unit of zoonotic rodent host richness.
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Affiliation(s)
- Daniah Alsufyani
- College of Sciences and Health Professions, King Saud Bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia.
- King Abdullah International Medical Research Center, Jeddah, Saudi Arabia.
| | - James Lindesay
- Computational Physics Laboratory, Department of Physics, Howard University, 2355 Sixth Street NW, Washington, DC, USA
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Hirpara A, Bloomfield M, Duesberg P. Speciation Theory of Carcinogenesis Explains Karyotypic Individuality and Long Latencies of Cancers. Genes (Basel) 2018; 9:genes9080402. [PMID: 30096943 PMCID: PMC6115917 DOI: 10.3390/genes9080402] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/14/2018] [Accepted: 07/27/2018] [Indexed: 12/20/2022] Open
Abstract
It has been known for over 100 years that cancers have individual karyotypes and arise only years to decades after initiating carcinogens. However, there is still no coherent theory to explain these definitive characteristics of cancer. The prevailing mutation theory holds that cancers are late because the primary cell must accumulate 3–8 causative mutations to become carcinogenic and that mutations, which induce chromosomal instability (CIN), generate the individual karyotypes of cancers. However, since there is still no proven set of mutations that transforms a normal to a cancer cell, we have recently advanced the theory that carcinogenesis is a form of speciation. This theory predicts carcinogens initiate cancer by inducing aneuploidy, which automatically unbalances thousands of genes and thus catalyzes chain-reactions of progressive aneuploidizations. Over time, these aneuploidizations have two endpoints, either non-viable karyotypes or very rarely karyotypes of new autonomous and immortal cancers. Cancer karyotypes are immortalized despite destabilizing congenital aneuploidy by clonal selections for autonomy—similar to those of conventional species. This theory predicts that the very low probability of converting the karyotype of a normal cell to that of a new autonomous cancer species by random aneuploidizations is the reason for the karyotypic individuality of new cancers and for the long latencies from carcinogens to cancers. In testing this theory, we observed: (1) Addition of mutagenic and non-mutagenic carcinogens to normal human and rat cells generated progressive aneuploidizations months before neoplastic transformation. (2) Sub-cloning of a neoplastic rat clone revealed heritable individual karyotypes, rather than the non-heritable karyotypes predicted by the CIN theory. (3) Analyses of neoplastic and preneoplastic karyotypes unexpectedly identified karyotypes with sets of 3–12 new marker chromosomes without detectable intermediates, consistent with single-step origins. We conclude that the speciation theory explains logically the long latencies from carcinogen exposure and the individuality of cancers. In addition, the theory supports the single-step origins of cancers, because karyotypic autonomy is all-or-nothing. Accordingly, we propose that preneoplastic aneuploidy and clonal neoplastic karyotypes provide more reliable therapeutic indications than current analyses of thousands of mutations.
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Affiliation(s)
- Ankit Hirpara
- Department of Molecular and Cell Biology, Donner Laboratory, University of California at Berkeley, Berkeley, CA 94720, USA.
| | - Mathew Bloomfield
- Department of Natural Sciences and Mathematics, Dominican University of California, San Rafael, CA 94 901, USA.
| | - Peter Duesberg
- Department of Molecular and Cell Biology, Donner Laboratory, University of California at Berkeley, Berkeley, CA 94720, USA.
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Bloomfield M, Duesberg P. Is cancer progression caused by gradual or simultaneous acquisitions of new chromosomes? Mol Cytogenet 2018; 11:4. [PMID: 29371887 PMCID: PMC5769399 DOI: 10.1186/s13039-017-0350-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 12/14/2017] [Indexed: 12/24/2022] Open
Abstract
Background Foulds defined, “Tumor progression (as a) permanent, irreversible qualitative change in one or more of its characters” (Cancer Res. 1954). Accordingly progressions, such as metastases and acquired drug-resistance, were since found to be subspecies of cancers with conserved and numerous new chromosomes. Here we ask whether cancers acquire numerous new chromosomes gradually or simultaneously in progressions. The currently prevailing theory of Nowell (Science, 1976) holds that unexplained “genetic instability” generates “variant sublines (with) changes in chromosome number” and that “clonal” progressions arise by “stepwise selection of more aggressive sublines”. The literature, however, contains many examples of “immediate” selections of progressions with numerous new chromosomes - notably experimentally initiated fusions between cancers and heterologous cells. Furthermore, the stepwise progression theory predicts intermediate sublines of cancers with multiple non-clonal additions of new chromosomes. However, the literature does not describe such intermediates. Results In view of these inconsistencies with stepwise progression we test here a saltational theory, in which the inherent variability of cancer-specific aneuploidy generates “immediate” progressions with individual clonal karyotypes, transcriptomes and phenotypes in single steps. Using cell fusion as an established controllable model of “immediate” progression, we generated seven immortal murine hybridomas by fusing immortal murine myeloma cells and normal antibody-producing B-cells with polyethylene glycol within a few minutes. These immortal hybridomas contained individual sets of 71 to 105 clonal chromosomes, compared to the 52 chromosomes of the parental myeloma. Thus the myeloma had gained 19 to 53 new clonal chromosomes in seven individual hybridomas in a single step. Furthermore, no stable intermediates were found, as would be predicted by a saltational process. Conclusions We conclude that random fusions between myelomas and normal B-cells generate clonal hybridomas with multiple, individual chromosomes in single steps. Similar single-step mechanisms may also generate the “late” clonal progressions of cancers with gains of numerous new chromosomes and thus explain the absence of intermediates. Latency would reflect the low probability of rare stochastic progressions. In conclusion, the karyotypic clonality of hybridomas and spontaneous progressions suggests karyotypic alterations as proximate causes of neoplastic progressions. Since cancer-specific aneuploidy catalyzes karyotypic variation, the degree of aneuploidy predicts the clinical risk of neoplastic progression, confirming classical predictions based on DNA content.
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Affiliation(s)
- Mathew Bloomfield
- 1Department of Molecular and Cell Biology, Donner Laboratory, University of California at Berkeley, Berkeley, CA 94720 USA.,2Present address: Department of Natural Sciences and Mathematics, Dominican University of California, San Rafael, CA USA
| | - Peter Duesberg
- 1Department of Molecular and Cell Biology, Donner Laboratory, University of California at Berkeley, Berkeley, CA 94720 USA
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Bloomfield M, Duesberg P. Inherent variability of cancer-specific aneuploidy generates metastases. Mol Cytogenet 2016; 9:90. [PMID: 28018487 PMCID: PMC5160004 DOI: 10.1186/s13039-016-0297-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 11/14/2016] [Indexed: 12/14/2022] Open
Abstract
Background The genetic basis of metastasis is still unclear because metastases carry individual karyotypes and phenotypes, rather than consistent mutations, and are rare compared to conventional mutation. There is however correlative evidence that metastasis depends on cancer-specific aneuploidy, and that metastases are karyotypically related to parental cancers. Accordingly we propose that metastasis is a speciation event. This theory holds that cancer-specific aneuploidy varies the clonal karyotypes of cancers automatically by unbalancing thousands of genes, and that rare variants form new autonomous subspecies with metastatic or other non-parental phenotypes like drug-resistance – similar to conventional subspeciation. Results To test this theory, we analyzed the karyotypic and morphological relationships between seven cancers and corresponding metastases. We found (1) that the cellular phenotypes of metastases were closely related to those of parental cancers, (2) that metastases shared 29 to 96% of their clonal karyotypic elements or aneusomies with the clonal karyotypes of parental cancers and (3) that, unexpectedly, the karyotypic complexity of metastases was very similar to that of the parental cancer. This suggests that metastases derive cancer-specific autonomy by conserving the overall complexity of the parental karyotype. We deduced from these results that cancers cause metastases by karyotypic variations and selection for rare metastatic subspecies. Further we asked whether metastases with multiple metastasis-specific aneusomies are assembled in one or multiple, sequential steps. Since (1) no stable karyotypic intermediates of metastases were observed in cancers here and previously by others, and (2) the karyotypic complexities of cancers are conserved in metastases, we concluded that metastases are generated from cancers in one step – like subspecies in conventional speciation. Conclusions We conclude that the risk of cancers to metastasize is proportional to the degree of cancer-specific aneuploidy, because aneuploidy catalyzes the generation of subspecies, including metastases, at aneuploidy-dependent rates. Since speciation by random chromosomal rearrangements and selection is unpredictable, the theory that metastases are karyotypic subspecies of cancers also explains Foulds’ rules, which hold that the origins of metastases are “abrupt” and that their phenotypes are “unpredictable.”
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Affiliation(s)
- Mathew Bloomfield
- Department of Molecular and Cell Biology; Donner Laboratory, University of California at Berkeley, Berkeley, CA 94720 USA ; Present address: Department of Natural Sciences and Mathematics, Dominican University of California, San Rafael, CA USA
| | - Peter Duesberg
- Department of Molecular and Cell Biology; Donner Laboratory, University of California at Berkeley, Berkeley, CA 94720 USA
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Borges A, Adega F, Chaves R. Establishment and characterization of a new feline mammary cancer cell line, FkMTp. Cytotechnology 2016; 68:1529-43. [PMID: 26883919 DOI: 10.1007/s10616-015-9912-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 08/14/2015] [Indexed: 12/28/2022] Open
Abstract
Studies on tumours in domestic animals are believed to greatly contribute to a better understanding of similar diseases in humans. Comparative studies have shown that feline mammary carcinomas share important features with human breast cancers, including a similar biological behaviour and histological appearance. In the present study we have established and characterized at different cellular levels one feline mammary cancer cell line, FkMTp, derived from a cat mammary carcinoma. The FkMTp cell line revealed to be a promising resource and tool to study tumour microevolution and all the mechanisms and processes involved in carcinogenesis from the tumour (primary culture) to the immortalized cell line. Several assays were conducted to assess the growth behaviour, differentiated morphology, anchorage independent growth in soft agar, wound-healing invasion and migration of the cell line across time (from the primary culture until the 160th passage). FkMTp revealed increased levels of anchorage independence, migration and invasion according to the course of time as well as different numbers of ploidy. These results demonstrate and validate the in vitro tumorigenicity of the FkMTp cell line. During the cell line establishment, it was cryopreserved approximately every six passages, including the tumour primary culture, allowing now the possibility to access almost any specific momento of the tumour progression.
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Affiliation(s)
- Ana Borges
- Laboratory of Cytogenomics and Animal Genomics (CAG), Department of Genetics and Biotechnology (DGB), Universityof Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
| | - Filomena Adega
- Laboratory of Cytogenomics and Animal Genomics (CAG), Department of Genetics and Biotechnology (DGB), Universityof Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
| | - Raquel Chaves
- Laboratory of Cytogenomics and Animal Genomics (CAG), Department of Genetics and Biotechnology (DGB), Universityof Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal.
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Zhu W, Kuziora M, Creasy T, Lai Z, Morehouse C, Guo X, Sebastian Y, Shen D, Huang J, Dry JR, Xue F, Jiang L, Yao Y, Higgs BW. BubbleTree: an intuitive visualization to elucidate tumoral aneuploidy and clonality using next generation sequencing data. Nucleic Acids Res 2015; 44:e38. [PMID: 26578606 PMCID: PMC4770205 DOI: 10.1093/nar/gkv1102] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 10/09/2015] [Indexed: 12/28/2022] Open
Abstract
Tumors are characterized by properties of genetic instability, heterogeneity, and significant oligoclonality. Elucidating this intratumoral heterogeneity is challenging but important. In this study, we propose a framework, BubbleTree, to characterize the tumor clonality using next generation sequencing (NGS) data. BubbleTree simultaneously elucidates the complexity of a tumor biopsy, estimating cancerous cell purity, tumor ploidy, allele-specific copy number, and clonality and represents this in an intuitive graph. We further developed a three-step heuristic method to automate the interpretation of the BubbleTree graph, using a divide-and-conquer strategy. In this study, we demonstrated the performance of BubbleTree with comparisons to similar commonly used tools such as THetA2, ABSOLUTE, AbsCN-seq and ASCAT, using both simulated and patient-derived data. BubbleTree outperformed these tools, particularly in identifying tumor subclonal populations and polyploidy. We further demonstrated BubbleTree's utility in tracking clonality changes from patients' primary to metastatic tumor and dating somatic single nucleotide and copy number variants along the tumor clonal evolution. Overall, the BubbleTree graph and corresponding model is a powerful approach to provide a comprehensive spectrum of the heterogeneous tumor karyotype in human tumors. BubbleTree is R-based and freely available to the research community (https://www.bioconductor.org/packages/release/bioc/html/BubbleTree.html).
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Affiliation(s)
- Wei Zhu
- Translational Bioinformatics, MedImmune, Gaithersburg, MD 20878, USA
| | - Michael Kuziora
- Translational Bioinformatics, MedImmune, Gaithersburg, MD 20878, USA
| | - Todd Creasy
- Translational Bioinformatics, MedImmune, Gaithersburg, MD 20878, USA
| | - Zhongwu Lai
- Oncology iMed, AstraZeneca, Waltham, MA 02451, USA
| | | | - Xiang Guo
- Clinical Biomarkers and Computational Biology, MedImmune, Gaithersburg, MD 20878, USA
| | - Yinong Sebastian
- Translational Bioinformatics, MedImmune, Gaithersburg, MD 20878, USA
| | - Dong Shen
- Translational Bioinformatics, MedImmune, Gaithersburg, MD 20878, USA
| | - Jiaqi Huang
- Translational Bioinformatics, MedImmune, Gaithersburg, MD 20878, USA
| | | | - Feng Xue
- Department of Liver Surgery and Liver Transplantation, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Liyan Jiang
- Department of Pulmonary, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Yihong Yao
- Translational Bioinformatics, MedImmune, Gaithersburg, MD 20878, USA
| | - Brandon W Higgs
- Translational Bioinformatics, MedImmune, Gaithersburg, MD 20878, USA
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Bloomfield M, Duesberg P. Karyotype alteration generates the neoplastic phenotypes of SV40-infected human and rodent cells. Mol Cytogenet 2015; 8:79. [PMID: 26500699 PMCID: PMC4618876 DOI: 10.1186/s13039-015-0183-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 09/28/2015] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Despite over 50 years of research, it remains unclear how the DNA tumor viruses SV40 and Polyoma cause cancers. Prevailing theories hold that virus-coded Tumor (T)-antigens cause cancer by inactivating cellular tumor suppressor genes. But these theories don't explain four characteristics of viral carcinogenesis: (1) less than one in 10,000 infected cells become cancer cells, (2) cancers have complex individual phenotypes and transcriptomes, (3) recurrent tumors without viral DNA and proteins, (4) preneoplastic aneuploidies and immortal neoplastic clones with individual karyotypes. RESULTS As an alternative theory we propose that viral carcinogenesis is a form of speciation, initiated by virus-induced aneuploidy. Since aneuploidy destabilizes the karyotype by unbalancing thousands of genes it catalyzes chain reactions of karyotypic and transcriptomic evolutions. Eventually rare karyotypes evolve that encode cancer-specific autonomy of growth. The low probability of forming new autonomous cancer-species by random karyotypic and transcriptomic variations predicts individual and clonal cancers. Although cancer karyotypes are congenitally aneuploid and thus variable, they are stabilized or immortalized by selections for variants with cancer-specific autonomy. Owing to these inherent variations cancer karyotypes are heterogeneous within clonal margins. To test this theory we analyzed karyotypes and phenotypes of SV40-infected human, rat and mouse cells developing into neoplastic clones. In all three systems we found (1) preneoplastic aneuploidies, (2) neoplastic clones with individual clonal but flexible karyotypes and phenotypes, which arose from less than one in 10,000 infected cells, survived over 200 generations, but were either T-antigen positive or negative, (3) spontaneous and drug-induced variations of neoplastic phenotypes correlating 1-to-1 with karyotypic variations. CONCLUSIONS Since all 14 virus-induced neoplastic clones tested contained individual clonal karyotypes and phenotypes, we conclude that these karyotypes have generated and since maintained these neoplastic clones. Thus SV40 causes cancer indirectly, like carcinogens, by inducing aneuploidy from which new cancer-specific karyotypes evolve automatically at low rates. This theory explains the (1) low probability of carcinogenesis per virus-infected cell, (2) the individuality and clonal flexibility of cancer karyotypes, (3) recurrence of neoplasias without viral T-antigens, and (4) the individual clonal karyotypes, transcriptomes and immortality of virus-induced neoplasias - all unexplained by current viral theories.
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Affiliation(s)
- Mathew Bloomfield
- Department of Molecular and Cell Biology, Donner Laboratory, University of California at Berkeley, Berkeley, CA USA
| | - Peter Duesberg
- Department of Molecular and Cell Biology, Donner Laboratory, University of California at Berkeley, Berkeley, CA USA
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Stepanenko A, Dmitrenko V. HEK293 in cell biology and cancer research: phenotype, karyotype, tumorigenicity, and stress-induced genome-phenotype evolution. Gene 2015; 569:182-90. [DOI: 10.1016/j.gene.2015.05.065] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 05/11/2015] [Accepted: 05/26/2015] [Indexed: 01/18/2023]
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Nicholson JM, Macedo JC, Mattingly AJ, Wangsa D, Camps J, Lima V, Gomes AM, Dória S, Ried T, Logarinho E, Cimini D. Chromosome mis-segregation and cytokinesis failure in trisomic human cells. eLife 2015; 4. [PMID: 25942454 PMCID: PMC4443816 DOI: 10.7554/elife.05068] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 05/01/2015] [Indexed: 12/11/2022] Open
Abstract
Cancer cells display aneuploid karyotypes and typically mis-segregate chromosomes at high rates, a phenotype referred to as chromosomal instability (CIN). To test the effects of aneuploidy on chromosome segregation and other mitotic phenotypes we used the colorectal cancer cell line DLD1 (2n = 46) and two variants with trisomy 7 or 13 (DLD1+7 and DLD1+13), as well as euploid and trisomy 13 amniocytes (AF and AF+13). We found that trisomic cells displayed higher rates of chromosome mis-segregation compared to their euploid counterparts. Furthermore, cells with trisomy 13 displayed a distinctive cytokinesis failure phenotype. We showed that up-regulation of SPG20 expression, brought about by trisomy 13 in DLD1+13 and AF+13 cells, is sufficient for the cytokinesis failure phenotype. Overall, our study shows that aneuploidy can induce chromosome mis-segregation. Moreover, we identified a trisomy 13-specific mitotic phenotype that is driven by up-regulation of a gene encoded on the aneuploid chromosome. DOI:http://dx.doi.org/10.7554/eLife.05068.001 The DNA in a human cell is divided between forty-six structures called chromosomes. Before a cell divides, it copies every chromosome so that each daughter cell will have the same DNA as the parent cell. These chromosomes align in the center of the cell and then the matching chromosomes are separated and pulled to opposite ends. However, in some cases the separation process does not work properly, which can produce cells that either have too many, or too few, chromosomes. Abnormal numbers of chromosomes within cells—called aneuploidy—is a leading cause of miscarriage and birth defects in humans. Aneuploidy is also a common feature of cancer cells. It is common for the chromosomes in cancer cells to be distributed unequally when the cell divides. This phenomenon is known as chromosomal instability, but the link between aneuploidy and chromosomal instability in cancer cells is not fully understood. Here, Nicholson et al. used live-cell imaging techniques to analyze healthy human cells and cancer cells that had either the normal forty-six chromosomes, or a defined extra chromosome. Nicholson et al. found that when the cells divided, the chromosomes in the cells that had an extra copy of chromosome 7 or 13 were more prone to distributing chromosomes unequally, compared to cells with a normal number of chromosomes. Nicholson et al. also observed that the cells with an extra chromosome 13 were unable to properly divide into two. These cells had increased levels of a protein called Spartin—which is important for the last stage in cell division—and this was responsible for the failure to produce two daughter cells. These findings show that aneuploidy can cause chromosomal instability in human cells. Furthermore, Nicholson et al. have identified a defect in cell division that is specifically caused by the presence of an extra chromosome 13 in human cells. A future challenge will be to determine how, and to what extent, different chromosomes can affect chromosome stability. This could be useful in the development of therapies against cancer cells with aneuploidy. DOI:http://dx.doi.org/10.7554/eLife.05068.002
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Affiliation(s)
- Joshua M Nicholson
- Department of Biological Sciences, Virginia Tech, Blacksburg, United States
| | - Joana C Macedo
- Aging and Aneuploidy Laboratory, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Aaron J Mattingly
- Department of Biological Sciences, Virginia Tech, Blacksburg, United States
| | - Darawalee Wangsa
- Genetics Branch, National Cancer Institute, National Institutes of Health, Bethesda, United States
| | - Jordi Camps
- Genetics Branch, National Cancer Institute, National Institutes of Health, Bethesda, United States
| | - Vera Lima
- Department of Genetics, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
| | - Ana M Gomes
- Aging and Aneuploidy Laboratory, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Sofia Dória
- Department of Genetics, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
| | - Thomas Ried
- Genetics Branch, National Cancer Institute, National Institutes of Health, Bethesda, United States
| | - Elsa Logarinho
- Aging and Aneuploidy Laboratory, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Daniela Cimini
- Department of Biological Sciences, Virginia Tech, Blacksburg, United States
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Stepanenko A, Andreieva S, Korets K, Mykytenko D, Huleyuk N, Vassetzky Y, Kavsan V. Step-wise and punctuated genome evolution drive phenotype changes of tumor cells. Mutat Res 2015; 771:56-69. [PMID: 25771981 DOI: 10.1016/j.mrfmmm.2014.12.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 12/14/2014] [Accepted: 12/18/2014] [Indexed: 06/04/2023]
Abstract
The pattern of genome evolution can be divided into two phases: the step-wise continuous phase (step-wise clonal evolution, stable dominant clonal chromosome aberrations (CCAs), and low frequency of non-CCAs, NCCAs) and punctuated phase (marked by elevated NCCAs and transitional CCAs). Depending on the phase, system stresses (the diverse CIN promoting factors) may lead to the very different phenotype responses. To address the contribution of chromosome instability (CIN) to phenotype changes of tumor cells, we characterized CCAs/NCCAs of HeLa and HEK293 cells, and their derivatives after genotoxic stresses (a stable plasmid transfection, ectopic expression of cancer-associated CHI3L1 gene or treatment with temozolomide) by conventional cytogenetics, copy number alterations (CNAs) by array comparative genome hybridization, and phenotype changes by cell viability and soft agar assays. Transfection of either the empty vector pcDNA3.1 or pcDNA3.1_CHI3L1 into 293 cells initiated the punctuated genome changes. In contrast, HeLa_CHI3L1 cells demonstrated the step-wise genome changes. Increased CIN correlated with lower viability of 293_pcDNA3.1 cells but higher colony formation efficiency (CFE). Artificial CHI3L1 production in 293_CHI3L1 cells increased viability and further contributed to CFE. The opposite growth characteristics of 293_CHI3L1 and HeLa_CHI3L1 cells were revealed. The effect and function of a (trans)gene can be opposite and versatile in cells with different genetic network, which is defined by genome context. Temozolomide treatment of 293_pcDNA3.1 cells intensified the stochastic punctuated genome changes and CNAs, and significantly reduced viability and CFE. In contrast, temozolomide treatment of HeLa_CHI3L1 cells promoted the step-wise genome changes, CNAs, and increased viability and CFE, which did not correlate with the ectopic CHI3L1 production. Thus, consistent coevolution of karyotypes and phenotypes was observed. CIN as a driving force of genome evolution significantly influences growth characteristics of tumor cells and should be always taken into consideration during the different experimental manipulations.
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Affiliation(s)
- Aleksei Stepanenko
- Department of Biosynthesis of Nucleic Acids, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv 03680, Ukraine.
| | - Svitlana Andreieva
- Department of Biosynthesis of Nucleic Acids, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv 03680, Ukraine
| | - Kateryna Korets
- Department of Biosynthesis of Nucleic Acids, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv 03680, Ukraine
| | - Dmytro Mykytenko
- Department of Biosynthesis of Nucleic Acids, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv 03680, Ukraine
| | - Nataliya Huleyuk
- Institute of Hereditary Pathology, National Academy of Medical Sciences of Ukraine, Lviv 79008, Ukraine
| | - Yegor Vassetzky
- CNRS UMR8126, Université Paris-Sud 11, Institut de Cancérologie Gustave Roussy, Villejuif 94805, France
| | - Vadym Kavsan
- Department of Biosynthesis of Nucleic Acids, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv 03680, Ukraine
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Parris GE. Cell-Cell Fusion, Chemotaxis and Metastasis. INTERCELLULAR COMMUNICATION IN CANCER 2015:227-254. [DOI: 10.1007/978-94-017-7380-5_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2025]
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Bloomfield M, McCormack A, Mandrioli D, Fiala C, Aldaz CM, Duesberg P. Karyotypic evolutions of cancer species in rats during the long latent periods after injection of nitrosourea. Mol Cytogenet 2014; 7:71. [PMID: 25614763 PMCID: PMC4302718 DOI: 10.1186/s13039-014-0071-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 10/10/2014] [Indexed: 11/22/2022] Open
Abstract
Background A century of research has established that cancers arise from tissues exposed to carcinogens only after long latencies of years to decades and have individual clonal karyotypes. Since speciation from known precursors also depends on long latencies and new species also have individual karyotypes, we and others have recently proposed that carcinogenesis is a form of speciation. According to this theory karyotypic evolutions generate new cancer species from normal cells as follows: Carcinogens induce aneuploidy (Figure 1). By unbalancing thousands of genes aneuploidy automatically destabilizes the karyotype and thus catalyzes random karyotypic variations. Selections of variants with proliferative phenotypes form non-clonal hyperplasias with persistently varying karyotypes. Very rare karyotypic variations form new cancer species with individual clonal karyotypes. Despite destabilization by the resulting congenital aneuploidies, cancer karyotypes are stabilized within narrow margins of variation by clonal selections for cancer-specific autonomy. Because all non-cancerous aneuploidies are unstable, all aneusomies of prospective cancers are joined in single-steps, rather than gradually. Since this mechanism is very inefficient, it predicts long latent periods from carcinogens to cancers and individual clonal cancer karyotypes. Results Here we have tested the predicted roles of karyotypic evolutions during the time course of carcinogenesis in an established experimental system. In this system injection of nitrosourea induces in female rats non-invasive mammary hyperplasias (“tumors”) after two or more months, and invasive carcinomas after six or more months. Accordingly four specific predictions were tested: (1) Invasive cancers are late and carry individual clonal karyotypes and phenotypes, (2) Persistent hyperplasias carry non-clonal karyotypes, (3) Non-clonal hyperplasias generate clonal cancers spontaneously but rarely, (4) Cancer-karyotypes arise with all individual clonal aneusomies in single-steps. All four predictions were experimentally confirmed. Conclusions Our results along with the literature reveal a coherent karyotypic mechanism of carcinogenesis: Carcinogens induce aneuploidy. The inherent instability of aneuploidy automatically catalyzes new karyotypic variations. Aneuploid karyotypes with proliferative phenotypes form varying non-clonal hyperplasias. Rare variations form cancer species with individual clonal karyotypes, which are stabilized by clonal selection for autonomy. The low odds of this mechanism explain the long latencies of carcinogenesis, the individuality and karyotypic clonality of cancers.
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Affiliation(s)
- Mathew Bloomfield
- Department of Molecular and Cell Biology, Donner Laboratory, University of California at Berkeley, Berkeley, CA USA
| | - Amanda McCormack
- Department of Molecular and Cell Biology, Donner Laboratory, University of California at Berkeley, Berkeley, CA USA
| | - Daniele Mandrioli
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD USA
| | - Christian Fiala
- Gynmed Ambulatorium, Mariahilferguertel 37, 1150 Vienna, Austria
| | - C Marcelo Aldaz
- Department of Molecular Carcinogenesis, M. D. Anderson Cancer Center, Smithville, Texas 78957 USA
| | - Peter Duesberg
- Department of Molecular and Cell Biology, Donner Laboratory, University of California at Berkeley, Berkeley, CA USA
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13
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Waters CE, Saldivar JC, Hosseini SA, Huebner K. The FHIT gene product: tumor suppressor and genome "caretaker". Cell Mol Life Sci 2014; 71:4577-87. [PMID: 25283145 DOI: 10.1007/s00018-014-1722-0] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 08/28/2014] [Indexed: 01/13/2023]
Abstract
The FHIT gene at FRA3B is one of the earliest and most frequently altered genes in the majority of human cancers. It was recently discovered that the FHIT gene is not the most fragile locus in epithelial cells, the cell of origin for most Fhit-negative cancers, eroding support for past claims that deletions at this locus are simply passenger events that are carried along in expanding cancer clones, due to extreme vulnerability to DNA damage rather than to loss of FHIT function. Indeed, recent reports have reconfirmed FHIT as a tumor suppressor gene with roles in apoptosis and prevention of the epithelial-mesenchymal transition. Other recent works have identified a novel role for the FHIT gene product, Fhit, as a genome "caretaker." Loss of this caretaker function leads to nucleotide imbalance, spontaneous replication stress, and DNA breaks. Because Fhit loss-induced DNA damage is "checkpoint blind," cells accumulate further DNA damage during subsequent cell cycles, accruing global genome instability that could facilitate oncogenic mutation acquisition and expedite clonal expansion. Loss of Fhit activity therefore induces a mutator phenotype. Evidence for FHIT as a mutator gene is discussed in light of these recent investigations of Fhit loss and subsequent genome instability.
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Affiliation(s)
- Catherine E Waters
- Biomedical Sciences Graduate Program, Ohio State University Wexner Medical Center, Columbus, OH, USA
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14
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Horne SD, Pollick SA, Heng HHQ. Evolutionary mechanism unifies the hallmarks of cancer. Int J Cancer 2014; 136:2012-21. [PMID: 24957955 DOI: 10.1002/ijc.29031] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 06/13/2014] [Indexed: 12/15/2022]
Abstract
The basis for the gene mutation theory of cancer that dominates current molecular cancer research consists of: the belief that gene-level aberrations such as mutations are the main cause of cancers, the concept that stepwise gene mutation accumulation drives cancer progression, and the hallmarks of cancer. The research community swiftly embraced the hallmarks of cancer, as such synthesis has supported the notions that common cancer genes are responsible for the majority of cancers and the complexity of cancer can be dissected into simplified molecular principles. The gene/pathway classification based on individual hallmarks provides explanation for the large number of diverse gene mutations, which is in contrast to the original estimation that only a handful of gene mutations would be discovered. Further, these hallmarks have been highly influential as they also provide the rationale and research direction for continued gene-based cancer research. While the molecular knowledge of these hallmarks is drastically increasing, the clinical implication remains limited, as cancer dynamics cannot be summarized by a few isolated/fixed molecular principles. Furthermore, the highly heterogeneous genetic signature of cancers, including massive stochastic genome alterations, challenges the utility of continuously studying each individual gene mutation under the framework of these hallmarks. It is therefore necessary to re-evaluate the concept of cancer hallmarks through the lens of cancer evolution. In this analysis, the evolutionary basis for the hallmarks of cancer will be discussed and the evolutionary mechanism of cancer suggested by the genome theory will be employed to unify the diverse molecular mechanisms of cancer.
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Affiliation(s)
- Steven D Horne
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI
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15
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Coward J, Harding A. Size Does Matter: Why Polyploid Tumor Cells are Critical Drug Targets in the War on Cancer. Front Oncol 2014; 4:123. [PMID: 24904834 PMCID: PMC4033620 DOI: 10.3389/fonc.2014.00123] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 05/11/2014] [Indexed: 12/14/2022] Open
Abstract
Tumor evolution presents a formidable obstacle that currently prevents the development of truly curative treatments for cancer. In this perspective, we advocate for the hypothesis that tumor cells with significantly elevated genomic content (polyploid tumor cells) facilitate rapid tumor evolution and the acquisition of therapy resistance in multiple incurable cancers. We appeal to studies conducted in yeast, cancer models, and cancer patients, which all converge on the hypothesis that polyploidy enables large phenotypic leaps, providing access to many different therapy-resistant phenotypes. We develop a flow-cytometry based method for quantifying the prevalence of polyploid tumor cells, and show the frequency of these cells in patient tumors may be higher than is generally appreciated. We then present recent studies identifying promising new therapeutic strategies that could be used to specifically target polyploid tumor cells in cancer patients. We argue that these therapeutic approaches should be incorporated into new treatment strategies aimed at blocking tumor evolution by killing the highly evolvable, therapy-resistant polyploid cell subpopulations, thus helping to maintain patient tumors in a drug sensitive state.
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Affiliation(s)
- Jermaine Coward
- Mater Medical Research Institute, Princess Alexandra Hospital , Woolloongabba, QLD , Australia
| | - Angus Harding
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute , Brisbane, QLD , Australia
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16
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Malcom JW, Kudra RS, Malone JH. The sex chromosomes of frogs: variability and tolerance offer clues to genome evolution and function. J Genomics 2014; 2:68-76. [PMID: 25031658 PMCID: PMC4091447 DOI: 10.7150/jgen.8044] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Frog sex chromosomes offer an ideal system for advancing our understanding of genome evolution and function because of the variety of sex determination systems in the group, the diversity of sex chromosome maturation states, the ease of experimental manipulation during early development. After briefly reviewing sex chromosome biology generally, we focus on what is known about frog sex determination, sex chromosome evolution, and recent, genomics-facilitated advances in the field. In closing we highlight gaps in our current knowledge of frog sex chromosomes, and suggest priorities for future research that can advance broad knowledge of gene dose and sex chromosome evolution.
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Affiliation(s)
- Jacob W Malcom
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, 06269 USA
| | - Randal S Kudra
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, 06269 USA
| | - John H Malone
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, 06269 USA
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17
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Menendez JA, Alarcón T, Corominas-Faja B, Cuyàs E, López-Bonet E, Martin AG, Vellon L. Xenopatients 2.0: reprogramming the epigenetic landscapes of patient-derived cancer genomes. Cell Cycle 2014; 13:358-70. [PMID: 24406535 DOI: 10.4161/cc.27770] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
In the science-fiction thriller film Minority Report, a specialized police department called "PreCrime" apprehends criminals identified in advance based on foreknowledge provided by 3 genetically altered humans called "PreCogs". We propose that Yamanaka stem cell technology can be similarly used to (epi)genetically reprogram tumor cells obtained directly from cancer patients and create self-evolving personalized translational platforms to foresee the evolutionary trajectory of individual tumors. This strategy yields a large stem cell population and captures the cancer genome of an affected individual, i.e., the PreCog-induced pluripotent stem (iPS) cancer cells, which are immediately available for experimental manipulation, including pharmacological screening for personalized "stemotoxic" cancer drugs. The PreCog-iPS cancer cells will re-differentiate upon orthotopic injection into the corresponding target tissues of immunodeficient mice (i.e., the PreCrime-iPS mouse avatars), and this in vivo model will run through specific cancer stages to directly explore their biological properties for drug screening, diagnosis, and personalized treatment in individual patients. The PreCog/PreCrime-iPS approach can perform sets of comparisons to directly observe changes in the cancer-iPS cell line vs. a normal iPS cell line derived from the same human genetic background. Genome editing of PreCog-iPS cells could create translational platforms to directly investigate the link between genomic expression changes and cellular malignization that is largely free from genetic and epigenetic noise and provide proof-of-principle evidence for cutting-edge "chromosome therapies" aimed against cancer aneuploidy. We might infer the epigenetic marks that correct the tumorigenic nature of the reprogrammed cancer cell population and normalize the malignant phenotype in vivo. Genetically engineered models of conditionally reprogrammable mice to transiently express the Yamanaka stemness factors following the activation of phenotypic copies of specific cancer diseases might crucially evaluate a "reprogramming cure" for cancer. A new era of xenopatients 2.0 generated via nuclear reprogramming of the epigenetic landscapes of patient-derived cancer genomes might revolutionize the current personalized translational platforms in cancer research.
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Affiliation(s)
- Javier A Menendez
- Metabolism & Cancer Group; Translational Research Laboratory; Catalan Institute of Oncology; Girona, Spain; Molecular Oncology Group; Girona Biomedical Research Institute (IDIBGI); Girona, Spain
| | - Tomás Alarcón
- Computational & Mathematical Biology Research Group; Centre de Recerca Matemàtica (CRM); Barcelona, Spain
| | - Bruna Corominas-Faja
- Metabolism & Cancer Group; Translational Research Laboratory; Catalan Institute of Oncology; Girona, Spain; Molecular Oncology Group; Girona Biomedical Research Institute (IDIBGI); Girona, Spain
| | - Elisabet Cuyàs
- Metabolism & Cancer Group; Translational Research Laboratory; Catalan Institute of Oncology; Girona, Spain; Molecular Oncology Group; Girona Biomedical Research Institute (IDIBGI); Girona, Spain
| | - Eugeni López-Bonet
- Department of Anatomical Pathology; Dr. Josep Trueta University Hospital of Girona; Girona, Spain
| | | | - Luciano Vellon
- IBYME; CONICET-Laboratorio de Immunohematología, Laboratorio de Química de Proteoglicanos y Matriz Extracelular; Buenos Aires, Argentina
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18
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Will we cure cancer by sequencing thousands of genomes? Mol Cytogenet 2013; 6:57. [PMID: 24330806 PMCID: PMC3906905 DOI: 10.1186/1755-8166-6-57] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 11/06/2013] [Indexed: 11/10/2022] Open
Abstract
The promise to understand cancer and develop efficacious therapies by sequencing thousands of cancers has not occurred. Mutations in specific genes termed oncogenes and tumor suppressor genes are extremely heterogeneous amongst the same type of cancer as well as between cancers. They provide little selective advantage to the cancer and in functional tests have yet to be shown to be sufficient for transformation. Here I discuss the karyotyptic theory of cancer and ask if it is time for a new approach to understanding and ultimately treating cancer.
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19
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McCormack A, Fan JL, Duesberg M, Bloomfield M, Fiala C, Duesberg P. Individual karyotypes at the origins of cervical carcinomas. Mol Cytogenet 2013; 6:44. [PMID: 24134916 PMCID: PMC3879223 DOI: 10.1186/1755-8166-6-44] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Accepted: 10/01/2013] [Indexed: 01/08/2023] Open
Abstract
Background In 1952 Papanicolaou et al. first diagnosed and graded cervical carcinomas based on individual “abnormal DNA contents” and cellular phenotypes. Surprisingly current papilloma virus and mutation theories of carcinomas do not mention these individualities. The viral theory holds that randomly integrated, defective genomes of papilloma viruses, which are often untranscribed, cause cervical carcinomas with unknown cofactors 20–50 years after infection. Virus-free carcinomas are attributed to mutations of a few tumor-suppressor genes, especially the p53 gene. But the paradox of how a few mutations or latent defective viral DNAs would generate carcinomas with endless individual DNA contents, degrees of malignancies and cellular phenotypes is unsolved. Since speciation predicts individuality, we test here the theory that cancers are autonomous species with individual clonal karyotypes and phenotypes. This theory postulates that carcinogens induce aneuploidy. By unbalancing mitosis genes aneuploidy catalyzes chain reactions of karyotypic evolutions. Most such evolutions end with non-viable karyotypes but a few become new cancer karyotypes. Despite congenitally unbalanced mitosis genes cancer karyotypes are stabilized by clonal selections for cancer-specific autonomy. Results To test the prediction of the speciation theory that individual carcinomas have individual clonal karyotypes and phenotypes, we have analyzed here the phenotypes and karyotypes of nine cervical carcinomas. Seven of these contained papilloma virus sequences and two did not. We determined phenotypic individuality and clonality based on the morphology and sociology of carcinoma cells in vitro. Karyotypic individuality and clonality were determined by comparing all chromosomes of 20 karyotypes of carcinomas in three-dimensional arrays. Such arrays list chromosome numbers on the x-axis, chromosome copy numbers on the y-axis and the number of karyotypes arrayed on the z-axis. We found (1) individual clonal karyotypes and phenotypes in all nine carcinomas, but no virus-specific markers, (2) 1-to-1 variations between carcinoma-specific karyotypes and phenotypes, e.g. drug-resistance and cell morphology, (3) proportionality between the copy numbers of chromosomes and the copy numbers of hundreds of over- and under-expressed mRNAs, (4) evidence that tobacco-carcinogens induce cervical carcinomas via aneuploidy, consistent with the speciation theory. Conclusions Since the individual clonal karyotypes of nine carcinomas correlated and co-varied 1-to-1 with complex individual transcriptomes and phenotypes, we have classical genetic and functional transcriptomic evidence to conclude that these karyotypes encode carcinomas - much like the clonal karyotypes that encode conventional species. These individual karyotypes explain the individual “DNA contents”, the endless grades of malignancies and the complex individual transcriptomes and phenotypes of carcinomas.
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Affiliation(s)
| | | | | | | | | | - Peter Duesberg
- Department of Molecular and Cell Biology; Donner Laboratory, University of California at Berkeley, Berkeley, CA, USA.
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20
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Nicholson JM, Cimini D. Cancer karyotypes: survival of the fittest. Front Oncol 2013; 3:148. [PMID: 23760367 PMCID: PMC3675379 DOI: 10.3389/fonc.2013.00148] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 05/22/2013] [Indexed: 11/13/2022] Open
Abstract
Cancer cells are typically characterized by complex karyotypes including both structural and numerical changes, with aneuploidy being a ubiquitous feature. It is becoming increasingly evident that aneuploidy per se can cause chromosome mis-segregation, which explains the higher rates of chromosome gain/loss observed in aneuploid cancer cells compared to normal diploid cells, a phenotype termed chromosomal instability (CIN). CIN can be caused by various mechanisms and results in extensive karyotypic heterogeneity within a cancer cell population. However, despite such karyotypic heterogeneity, cancer cells also display predominant karyotypic patterns. In this review we discuss the mechanisms of CIN, with particular emphasis on the role of aneuploidy on CIN. Further, we discuss the potential functional role of karyotypic patterns in cancer.
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21
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Coleman AE, McNeil N, Kovalchuck AL, Wangsa D, Ried T, Wang H. Cellular exposure to muscle relaxants and propofol could lead to genomic instability in vitro. J Biomed Res 2013; 26:117-24. [PMID: 23554740 PMCID: PMC3597328 DOI: 10.1016/s1674-8301(12)60021-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2011] [Revised: 01/05/2012] [Accepted: 01/28/2012] [Indexed: 11/25/2022] Open
Abstract
Anesthesia is widely used in several medical settings and accepted as safe. However, there is some evidence that anesthetic agents can induce genomic changes leading to neural degeneration or apoptosis. Although chromosomal changes have not been observed in vivo, this is most likely due to DNA repair mechanisms, apoptosis, or cellular senescence. Potential chromosomal alterations after exposure to common anesthetic agents may be relevant in patients with genomic instability syndromes or with aggressive treatment of malignancies. In this study, the P388 murine B cells were cultured in vitro, and spectral karyotyping (SKY) was utilized to uncover genome-wide changes. Clinically relevant doses of cisatracurium and propofol increased structural and numerical chromosomal instability. These results may be relevant in patients with underlying chromosomal instability syndromes or concurrently being exposed to chemotherapeutic agents. Future studies may include utilization of stimulated peripheral blood lymphocytes to further confirm the significance of these results.
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Affiliation(s)
- Allen Edward Coleman
- Department of Anesthesiology, Wayne State University, Detroit Medical Center, Detroit, Michigan 48201, USA
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22
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Duesberg P, McCormack A. Immortality of cancers: a consequence of inherent karyotypic variations and selections for autonomy. Cell Cycle 2013; 12:783-802. [PMID: 23388461 PMCID: PMC3610726 DOI: 10.4161/cc.23720] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Immortality is a common characteristic of cancers, but its origin and purpose are still unclear. Here we advance a karyotypic theory of immortality based on the theory that carcinogenesis is a form of speciation. Accordingly, cancers are generated from normal cells by random karyotypic rearrangements and selection for cancer-specific reproductive autonomy. Since such rearrangements unbalance long-established mitosis genes, cancer karyotypes vary spontaneously but are stabilized perpetually by clonal selections for autonomy. To test this theory we have analyzed neoplastic clones, presumably immortalized by transfection with overexpressed telomerase or with SV40 tumor virus, for the predicted clonal yet flexible karyotypes. The following results were obtained: (1) All immortal tumorigenic lines from cells transfected with overexpressed telomerase had clonal and flexible karyotypes; (2) Searching for the origin of such karyotypes, we found spontaneously increasing, random aneuploidy in human fibroblasts early after transfection with overexpressed telomerase; (3) Late after transfection, new immortal tumorigenic clones with new clonal and flexible karyotypes were found; (4) Testing immortality of one clone during 848 unselected generations showed the chromosome number was stable, but the copy numbers of 36% of chromosomes drifted ± 1; (5) Independent immortal tumorigenic clones with individual, flexible karyotypes arose after individual latencies; (6) Immortal tumorigenic clones with new flexible karyotypes also arose late from cells of a telomerase-deficient mouse rendered aneuploid by SV40 virus. Because immortality and tumorigenicity: (1) correlated exactly with individual clonal but flexible karyotypes; (2) originated simultaneously with such karyotypes; and (3) arose in the absence of telomerase, we conclude that clonal and flexible karyotypes generate the immortality of cancers.
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Affiliation(s)
- Peter Duesberg
- Department of Molecular and Cell Biology, Donner Laboratory, University of California at Berkeley, Berkeley, CA, USA.
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23
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Castro-Gamero AM, Borges KS, Lira RC, Andrade AF, Fedatto PF, Cruzeiro GAV, Silva RB, Fontes AM, Valera ET, Bobola M, Scrideli CA, Tone LG. Chromosomal heterogeneity and instability characterize pediatric medulloblastoma cell lines and affect neoplastic phenotype. Cytotechnology 2013; 65:871-85. [PMID: 23325114 DOI: 10.1007/s10616-012-9529-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 12/20/2012] [Indexed: 01/09/2023] Open
Abstract
Chromosomal heterogeneity is a hallmark of most tumors and it can drive critical events as growth advantages, survival advantages, progression and karyotypic evolution. Medulloblastoma (MB) is the most common malignant central nervous system tumor in children. This work attempted to investigate chromosomal heterogeneity and instability profiles of two MB pediatric cell lines and their relationship with cell phenotype. We performed GTG-banding and cytokinesis-block micronucleus cytome assays, as well as morphological characterization, cell population doubling time, colony-forming efficiency, and chemo-sensitivity assays in two pediatric MB cell lines (UW402 and UW473). Both MB cells showed a high chromosomal heterogeneity. UW473 cells showed ~2 fold higher both clonal- and non-clonal chromosomal alterations than UW402 cells. Besides, UW473 showed two clonal-groups well-differentiated by ploidy level (<2n> and <4n>) and also presented a significantly higher number of chromosomal instability biomarkers. These results were associated with high morphological heterogeneity and survival advantages for UW473 and proliferation advantages for UW402 cells. Moreover, UW473 was significantly more sensitive to methotrexate, temozolomide and cisplatin while UW402 cells were more sensitive to doxorubicin. These data suggest that distinct different degrees of karyotypic heterogeneity and instability may affect neoplasic phenotype of MB cells. These findings bring new insights into cell and tumor biology.
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Frankenberg-Schwager M, Gregus A. Chromosomal instability induced by mammography X-rays in primary human fibroblasts from BRCA1 and BRCA2 mutation carriers. Int J Radiat Biol 2012; 88:846-57. [PMID: 22788243 DOI: 10.3109/09553002.2012.711500] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE Mammography X-rays are known to induce DNA double-strand breaks (DSB) whose error-free recombinational repair requires the function of the tumour repressor genes BRCA1 (breast-cancer-associated gene 1) and BRCA2 (breast-cancer-associated gene 2). Since un- or misrepaired DSB lead to chromosomal anomalies which may promote the development of breast cancer, we have studied the potential of mammography X-rays for immediate and delayed induction of chromosomal anomalies in human primary fibroblasts from BRCA1 and BRCA2 mutation carriers. MATERIALS AND METHODS Primary human fibroblasts from three BRCA1, three BRCA2 mutation carriers, one BRCA2-deficient fanconi anemia (FA) patient and three normal individuals were exposed to various doses of mammography X-rays. Chromosomal anomalies at first mitosis and at several population doublings post-irradiation were assayed (Giemsa staining and Fish [fluorescence in situ hybridization]). RESULTS No effect of the BRCA mutation status was observed on survival curves after exposure to mammography X-rays and on the dose-dependent increase of chromosomal anomalies at first mitosis post-irradiation. In contrast, several population doublings after exposure to a low dose of only 0.5 Gy chromosomal instability, manifested as gross chromosomal rearrangements and aneuploidy, had developed in BRCA2-deficient FA fibroblasts and in some - but not all - BRCA heterozygous fibroblasts. CONCLUSIONS Low doses of mammography X-rays have the potential to induce chromosomal instability in fibroblasts from BRCA mutation carriers: Cells exhibit gross chromosomal rearrangements and aneuploidy similar to those observed in breast cancer cells. These results suggest that for women carrying a BRCA mutation early and frequent screening with mammography X-rays may not be the method of choice to detect breast cancer.
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25
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Stepanenko AA, Kavsan VM. Evolutionary karyotypic theory of cancer versus conventional cancer gene mutation theory. ACTA ACUST UNITED AC 2012. [DOI: 10.7124/bc.000059] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- A. A. Stepanenko
- Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine
| | - V. M. Kavsan
- Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine
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Duesberg P, Iacobuzio-Donahue C, Brosnan JA, McCormack A, Mandrioli D, Chen L. Origin of metastases: subspecies of cancers generated by intrinsic karyotypic variations. Cell Cycle 2012; 11:1151-66. [PMID: 22377695 DOI: 10.4161/cc.11.6.19580] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Conventional mutation theories do not explain (1) why the karyotypes of metastases are related to those of parental cancers but not to those of metastases of other cancers and (2) why cancers metastasize at rates that often far exceed those of conventional mutations. To answer these questions, we advance here the theory that metastases are autonomous subspecies of cancers, rather than mutations. Since cancers are species with intrinsically flexible karyotypes, they can generate new subspecies by spontaneous karyotypic rearrangements. This phylogenetic theory predicts that metastases are karyotypically related to parental cancers but not to others. Testing these predictions on metastases from two pancreatic cancers, we found: (1) Metastases had individual karyotypes and phenotypes. The karyotypes of metastases were related to, but different from, those of parental cancers in 11 out of 37 and 26 out of 49 parental chromosomal units. Chromosomal units are defined as intact chromosomes with cancer-specific copy numbers and marker chromosomes that are > 50% clonal. (2) Metastases from the two different cancers did not share chromosomal units. Testing the view that multi-chromosomal rearrangements occur simultaneously in cancers, as opposed to sequentially, we found spontaneous non-clonal rearrangements with as many new chromosomal units as in authentic metastases. We conclude that metastases are individual autonomous species differing from each other and parental cancers in species-specific karyotypes and phenotypes. They are generated from parental cancers by multiple simultaneous karyotypic rearrangements, much like new species. The species-specific individualities of metastases explain why so many searches for commonalities have been unsuccessful.
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Affiliation(s)
- Peter Duesberg
- Department of Molecular and Cell Biology, Donner Laboratory, University of California at Berkeley, Berkeley, CA, USA.
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28
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Kościelak J. The hypothesis on function of glycosphingolipids and ABO blood groups revisited. Neurochem Res 2012; 37:1170-84. [PMID: 22407244 DOI: 10.1007/s11064-012-0734-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2011] [Revised: 12/23/2011] [Accepted: 02/15/2012] [Indexed: 12/12/2022]
Abstract
Twenty-five years ago the author proposed new ideas of glycoprotein (GPs) and glycosphingolipid (GSLs) functions at the cell membrane. The GPs, apart from their glycan carrying capacity, were assumed to have specific, protein associated, functions. In contrast, GSLs such as those of globo and neolacto/lacto series, were considered to be energetically cheap membrane packing substances, filling in membrane spaces not covered with functional GPs. The terminal carbohydrate structures of the neolacto/lacto GSLs, i.e., sialic acid residues and ABH glycotopes, were postulated to have either regulatory or protective functions, respectively. A special active role was ascribed to terminal β-galactosyl residues of GSLs and GPs. Gangliosides were considered to be functional GSLs. In the present review the author discusses these old ideas in context of the contemporary knowledge and comes to the conclusion that they have not aged.
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Affiliation(s)
- Jerzy Kościelak
- Department of Biochemistry, Institute of Hematology and Transfusion Medicine, Warsaw, Poland.
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29
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Abstract
Aneuploidy is a common feature of cancer cells, and is believed to play a critical role in tumorigenesis and cancer progression. Most cancer cells also exhibit high rates of mitotic chromosome mis-segregation, a phenomenon known as chromosomal instability, which leads to high variability of the karyotype. Here, we describe the nature, nuances, and implications of cancer karyotypic diversity. Moreover, we summarize recent studies aimed at identifying the mitotic defects that may be responsible for inducing chromosome mis-segregation in cancer cells. These include kinetochore attachment errors, spindle assembly checkpoint dysfunction, mitotic spindle defects, and other cell division inaccuracies. Finally, we discuss how such mitotic errors generate karyotypic diversity in cancer cells.
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30
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Abstract
A good account of the nature of cancer should provide not only a description of its consistent features, but also how they arise, how they are maintained, why conventional chemotherapy succeeds, and fails, and where to look for better targets. Cancer was once regarded as enigmatic and inexplicable; more recently, the "mutation theory," based on random alterations in a relatively small set of proto-oncogenes and tumor suppressor genes, has enjoyed widespread acceptance. The "mutation theory," however, is noticeable for its failure to explain the basis of differential chemosensitivity, for providing a paucity of targets, especially druggable ones, and for justifying the development of targeted therapies with, in general, disappointingly abbreviated clinical benefit. Furthermore, this theory has mistakenly predicted a widespread commonality of consistent genetic abnormalities across the range of cancers, whereas the opposite, that is, roiling macrogenomic instability, is generally the rule. In contrast, concerning what actually is consistent, that is, the suite of metabolic derangements common to virtually all, especially aggressive, cancers, the "Mutation Theory" has nothing to say. Other hypotheses merit serious consideration "aneuploidy theories" posit whole-genome instability and imbalance as causally responsible for the propagation of the tumor. Another approach, that is, "derepression atavism," suggests cancer results from the release of an ancient survival program, characterized by the emergence of remarkably primitive features such as unicellularity, fermentation, and immortality; existential goals are served by heuristic genomic instability coupled with host-to-tumor biomass interconversion, mediated by the Warburg effect, a major component of the program. Carcinogenesis is here seen as a process of de-speciation; however, genomic nonrestabilization raises issues as to where on the tree of life cancers belong, as a genuinely alternative modus vivendi. Philosophical considerations aside, genomic instability offers the prospect of subtle new therapies based on loss of information rather than gain; and the consistent, specific, and broad-spectrum perfidy of the Warburg effect highlights a supplemental target of the highest priority.
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Affiliation(s)
- Mark D Vincent
- Department of Medical Oncology, London Regional Cancer Centre, London Health Sciences Centre, Ontario, Canada
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31
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Lee AJX, Swanton C. Tumour heterogeneity and drug resistance: personalising cancer medicine through functional genomics. Biochem Pharmacol 2011; 83:1013-20. [PMID: 22192819 DOI: 10.1016/j.bcp.2011.12.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2011] [Revised: 12/04/2011] [Accepted: 12/06/2011] [Indexed: 02/08/2023]
Abstract
Intrinsic and acquired drug resistance leads to the eventual failure of cancer treatment regimens in the majority of advanced solid tumours. Understanding drug resistance mechanisms will prove vital in the future development of personalised therapeutic approaches. Functional genomics technologies may permit the discovery of predictive biomarkers by unravelling pathways involved in drug resistance and allow the systematic identification of novel therapeutic targets. Such technologies offer the opportunity to develop personalised treatments and diagnostic tools that may improve the survival and quality of life of patients with cancer. However, despite progress in biomarker and drug target discovery, inter-tumour and intra-tumour molecular heterogeneity will limit the effective treatment of this disease. Combining an improved understanding of cancer cell survival mechanisms associated with intra-tumour heterogeneity and drug resistance may allow the selection of patients for specific treatment regimens that will maximise benefit, limit the acquisition of drug resistance and lessen the impact of deleterious side effects.
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Affiliation(s)
- Alvin J X Lee
- Translational Cancer Therapeutics, Cancer Research UK London Research Institute, UK.
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32
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Heng HH, Liu G, Stevens JB, Bremer SW, Ye KJ, Abdallah BY, Horne SD, Ye CJ. Decoding the genome beyond sequencing: The new phase of genomic research. Genomics 2011; 98:242-52. [DOI: 10.1016/j.ygeno.2011.05.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Revised: 05/16/2011] [Accepted: 05/18/2011] [Indexed: 10/18/2022]
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33
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Steinarsdottir M, Gudmundsson IH, Jonasson JG, Olafsdottir EJ, Eyfjörd JE, Ogmundsdottir HM. Cytogenetic polyclonality of breast carcinomas: association with clinico-pathological characteristics and outcome. Genes Chromosomes Cancer 2011; 50:930-9. [PMID: 21910159 DOI: 10.1002/gcc.20915] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 07/12/2011] [Indexed: 12/21/2022] Open
Abstract
Routinely used prognostic factors fail to predict clinical outcome in a significant proportion of breast cancer patients, implying that they can not detect some important biological characteristics. Chromosomal changes have been described in breast carcinomas for many years but their significance is not clear. We compared chromosomal changes with clinico-pathological characteristics and clinical outcome in 203 breast cancer patients with a follow-up of 9-18 years. Combining data from classical cytogenetics and flow cytometry revealed chromosomal abnormalities in 142 cases (70%). Of these, 51 (35.9%) contained two or more cytogenetically abnormal clones. Polyclonality was significantly associated with poor breast-cancer-specific survival (P = 0.03) within 5 years, independent of tumor size, lymph node metastases, and hormone receptors. Specific changes were similar to those previously described, but a new finding was a significant association between del 3p12p21 and poor survival. Polyclonality was significantly associated with TP53-mutations but not with a germline BRCA2 mutation. Less than one third of the polyclonal samples were identified by flow cytometry alone. Cytogenetic changes were detected in 17 out of 114 samples from non-tumorous tissue (15%), two of them identical with a clone in the corresponding tumor. Several samples contained clearly unrelated clones within the tumor and outside, implying either multifocal origin or early divergence. In conclusion, the common deletion on Chromosome 3p12p21 was associated with poor clinical outcome. Chromosomal polyclonality is common in breast carcinomas and predicts poor survival. Polyclonality was poorly detected by one-sample flow cytometry. Multiple sampling might improve the detection rate.
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Affiliation(s)
- Margret Steinarsdottir
- Chromosome Laboratory, Department of Genetics and Molecular Medicine, Landspitali University Hospital, Reykjavík, Iceland
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34
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Lee AJX, Endesfelder D, Rowan AJ, Walther A, Birkbak NJ, Futreal PA, Downward J, Szallasi Z, Tomlinson IPM, Howell M, Kschischo M, Swanton C. Chromosomal instability confers intrinsic multidrug resistance. Cancer Res 2011; 71:1858-70. [PMID: 21363922 DOI: 10.1158/0008-5472.can-10-3604] [Citation(s) in RCA: 346] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Aneuploidy is associated with poor prognosis in solid tumors. Spontaneous chromosome missegregation events in aneuploid cells promote chromosomal instability (CIN) that may contribute to the acquisition of multidrug resistance in vitro and heighten risk for tumor relapse in animal models. Identification of distinct therapeutic agents that target tumor karyotypic complexity has important clinical implications. To identify distinct therapeutic approaches to specifically limit the growth of CIN tumors, we focused on a panel of colorectal cancer (CRC) cell lines, previously classified as either chromosomally unstable (CIN(+)) or diploid/near-diploid (CIN(-)), and treated them individually with a library of kinase inhibitors targeting components of signal transduction, cell cycle, and transmembrane receptor signaling pathways. CIN(+) cell lines displayed significant intrinsic multidrug resistance compared with CIN(-) cancer cell lines, and this seemed to be independent of somatic mutation status and proliferation rate. Confirming the association of CIN rather than ploidy status with multidrug resistance, tetraploid isogenic cells that had arisen from diploid cell lines displayed lower drug sensitivity than their diploid parental cells only with increasing chromosomal heterogeneity and isogenic cell line models of CIN(+) displayed multidrug resistance relative to their CIN(-) parental cancer cell line derivatives. In a meta-analysis of CRC outcome following cytotoxic treatment, CIN(+) predicted worse progression-free or disease-free survival relative to patients with CIN(-) disease. Our results suggest that stratifying tumor responses according to CIN status should be considered within the context of clinical trials to minimize the confounding effects of tumor CIN status on drug sensitivity.
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Affiliation(s)
- Alvin J X Lee
- Translational Cancer Therapeutics Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
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35
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Roschke AV, Kirsch IR. Targeting karyotypic complexity and chromosomal instability of cancer cells. Curr Drug Targets 2011; 11:1341-50. [PMID: 20840077 DOI: 10.2174/1389450111007011341] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Accepted: 03/12/2010] [Indexed: 11/22/2022]
Abstract
Multiple karyotypic abnormalities and chromosomal instability are characteristic features of many cancers that are relatively resistant to chemotherapeutic agents currently used in the clinic. These same features represent potentially targetable "states" that are essentially tumor specific. The assessment of the chromosomal state of a cancer cell population may provide a guide for the selection or development of drugs active against aggressive and intractable cancers.
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Affiliation(s)
- Anna V Roschke
- Genetics Branch, Center for Cancer Research, National Cancer Institute, Building NNMC8, Room 5101, Bethesda, MD 20889-5105, USA.
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36
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37
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Tian T, Olson S, Whitacre JM, Harding A. The origins of cancer robustness and evolvability. Integr Biol (Camb) 2010; 3:17-30. [PMID: 20944865 DOI: 10.1039/c0ib00046a] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Unless diagnosed early, many adult cancers remain incurable diseases. This is despite an intense global research effort to develop effective anticancer therapies, calling into question the use of rational drug design strategies in targeting complex disease states such as cancer. A fundamental challenge facing researchers and clinicians is that cancers are inherently robust biological systems, able to survive, adapt and proliferate despite the perturbations resulting from anticancer drugs. It is essential that the mechanisms underlying tumor robustness be formally studied and characterized, as without a thorough understanding of the principles of tumor robustness, strategies to overcome therapy resistance are unlikely to be found. Degeneracy describes the ability of structurally distinct system components (e.g. proteins, pathways, cells, organisms) to be conditionally interchangeable in their contribution to system traits and it has been broadly implicated in the robustness and evolvability of complex biological systems. Here we focus on one of the most important mechanisms underpinning tumor robustness and degeneracy, the cellular heterogeneity that is the hallmark of most solid tumors. Based on a combination of computational, experimental and clinical studies we argue that stochastic noise is an underlying cause of tumor heterogeneity and particularly degeneracy. Drawing from a number of recent data sets, we propose an integrative model for the evolution of therapy resistance, and discuss recent computational studies that propose new therapeutic strategies aimed at defeating the adaptable cancer phenotype.
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38
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Klein A, Li N, Nicholson JM, McCormack AA, Graessmann A, Duesberg P. Transgenic oncogenes induce oncogene-independent cancers with individual karyotypes and phenotypes. ACTA ACUST UNITED AC 2010; 200:79-99. [PMID: 20620590 DOI: 10.1016/j.cancergencyto.2010.04.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 03/24/2010] [Accepted: 04/01/2010] [Indexed: 11/25/2022]
Abstract
Cancers are clones of autonomous cells defined by individual karyotypes, much like species. Despite such karyotypic evidence for causality, three to six synergistic mutations, termed oncogenes, are generally thought to cause cancer. To test single oncogenes, they are artificially activated with heterologous promoters and spliced into the germ line of mice to initiate cancers with collaborating spontaneous oncogenes. Because such cancers are studied as models for the treatment of natural cancers with related oncogenes, the following must be answered: 1) which oncogenes collaborate with the transgenes in cancers; 2) how do single transgenic oncogenes induce diverse cancers and hyperplasias; 3) what maintains cancers that lose initiating transgenes; 4) why are cancers aneuploid, over- and underexpressing thousands of normal genes? Here we try to answer these questions with the theory that carcinogenesis is a form of speciation. We postulate that transgenic oncogenes initiate carcinogenesis by inducing aneuploidy. Aneuploidy destabilizes the karyotype by unbalancing teams of mitosis genes. This instability thus catalyzes the evolution of new cancer species with individual karyotypes. Depending on their degree of aneuploidy, these cancers then evolve new subspecies. To test this theory, we have analyzed the karyotypes and phenotypes of mammary carcinomas of mice with transgenic SV40 tumor virus- and hepatitis B virus-derived oncogenes. We found that (1) a given transgene induced diverse carcinomas with individual karyotypes and phenotypes; (2) these karyotypes coevolved with newly acquired phenotypes such as drug resistance; (3) 8 of 12 carcinomas were transgene negative. Having found one-to-one correlations between individual karyotypes and phenotypes and consistent coevolutions of karyotypes and phenotypes, we conclude that carcinogenesis is a form of speciation and that individual karyotypes maintain cancers as they maintain species. Because activated oncogenes destabilize karyotypes and are dispensable in cancers, we conclude that they function indirectly, like carcinogens. Such oncogenes would thus not be valid models for the treatment of cancers.
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Affiliation(s)
- Andreas Klein
- Charité-Universitätsmedizin Berlin, Campus Charité Mitte, Institut für Biochemie, Monbijoustrasse 2, Berlin, Germany
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39
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Pavelka N, Rancati G, Li R. Dr Jekyll and Mr Hyde: role of aneuploidy in cellular adaptation and cancer. Curr Opin Cell Biol 2010; 22:809-15. [PMID: 20655187 DOI: 10.1016/j.ceb.2010.06.003] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 06/08/2010] [Indexed: 12/26/2022]
Abstract
When cells in our body change their genome and develop into cancer, we blame it on genome instability. When novel species conquer inhospitable environments, we credit it to genome evolution. From a cellular perspective, however, both processes are outcomes of the same fundamental biological properties-genome and pathway plasticity and the natural selection of cells that escape death and acquire growth advantages. Unraveling the consequences of genome plasticity at a cellular level is not only central to the understanding of species evolution but also crucial to deciphering important cell biological problems, such as how cancer cells emerge and how pathogens develop drug resistance. Aside from the well-known role of DNA sequence mutations, recent evidence suggests that changes in DNA copy numbers in the form of segmental or whole-chromosome aneuploidy can bring about large phenotypic variation. Although usually detrimental under conditions suitable for normal proliferation of euploid cells, aneuploidization may be a frequently occurring genetic change that enables pathogens or cancer cells to escape physiological or pharmacological roadblocks.
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Affiliation(s)
- Norman Pavelka
- Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO 64110, USA
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40
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Schvartzman JM, Sotillo R, Benezra R. Mitotic chromosomal instability and cancer: mouse modelling of the human disease. Nat Rev Cancer 2010; 10:102-15. [PMID: 20094045 PMCID: PMC5526619 DOI: 10.1038/nrc2781] [Citation(s) in RCA: 334] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The stepwise progression from an early dysplastic lesion to full-blown metastatic malignancy is associated with increases in genomic instability. Mitotic chromosomal instability - the inability to faithfully segregate equal chromosome complements to two daughter cells during mitosis - is a widespread phenomenon in solid tumours that is thought to serve as the fuel for tumorigenic progression. How chromosome instability (CIN) arises in tumours and what consequences it has are still, however, hotly debated issues. Here we review the recent literature with an emphasis on models that recapitulate observations from human disease.
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Affiliation(s)
- Juan-Manuel Schvartzman
- Program in Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
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41
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Vorsanova SG, Yurov YB, Iourov IY. Human interphase chromosomes: a review of available molecular cytogenetic technologies. Mol Cytogenet 2010; 3:1. [PMID: 20180947 PMCID: PMC2830939 DOI: 10.1186/1755-8166-3-1] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Accepted: 01/11/2010] [Indexed: 01/05/2023] Open
Abstract
Human karyotype is usually studied by classical cytogenetic (banding) techniques. To perform it, one has to obtain metaphase chromosomes of mitotic cells. This leads to the impossibility of analyzing all the cell types, to moderate cell scoring, and to the extrapolation of cytogenetic data retrieved from a couple of tens of mitotic cells to the whole organism, suggesting that all the remaining cells possess these genomes. However, this is far from being the case inasmuch as chromosome abnormalities can occur in any cell along ontogeny. Since somatic cells of eukaryotes are more likely to be in interphase, the solution of the problem concerning studying postmitotic cells and larger cell populations is interphase cytogenetics, which has become more or less applicable for specific biomedical tasks due to achievements in molecular cytogenetics (i.e. developments of fluorescence in situ hybridization -- FISH, and multicolor banding -- MCB). Numerous interphase molecular cytogenetic approaches are restricted to studying specific genomic loci (regions) being, however, useful for identification of chromosome abnormalities (aneuploidy, polyploidy, deletions, inversions, duplications, translocations). Moreover, these techniques are the unique possibility to establish biological role and patterns of nuclear genome organization at suprachromosomal level in a given cell. Here, it is to note that this issue is incompletely worked out due to technical limitations. Nonetheless, a number of state-of-the-art molecular cytogenetic techniques (i.e multicolor interphase FISH or interpahase chromosome-specific MCB) allow visualization of interphase chromosomes in their integrity at molecular resolutions. Thus, regardless numerous difficulties encountered during studying human interphase chromosomes, molecular cytogenetics does provide for high-resolution single-cell analysis of genome organization, structure and behavior at all stages of cell cycle.
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Affiliation(s)
- Svetlana G Vorsanova
- Institute of Pediatrics and Children Surgery, Rosmedtechnologii, Moscow, 127412, Russia
- National Research Center of Mental Health, Russian Academy of Medical Sciences, Moscow 119152, Russia
| | - Yuri B Yurov
- Institute of Pediatrics and Children Surgery, Rosmedtechnologii, Moscow, 127412, Russia
- National Research Center of Mental Health, Russian Academy of Medical Sciences, Moscow 119152, Russia
| | - Ivan Y Iourov
- Institute of Pediatrics and Children Surgery, Rosmedtechnologii, Moscow, 127412, Russia
- National Research Center of Mental Health, Russian Academy of Medical Sciences, Moscow 119152, Russia
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