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Baro B, Rodriguez-Rodriguez JA, Calabria I, Hernáez ML, Gil C, Queralt E. Dual Regulation of the mitotic exit network (MEN) by PP2A-Cdc55 phosphatase. PLoS Genet 2013; 9:e1003966. [PMID: 24339788 PMCID: PMC3854864 DOI: 10.1371/journal.pgen.1003966] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 10/04/2013] [Indexed: 12/17/2022] Open
Abstract
Exit from mitosis in budding yeast is triggered by activation of the key mitotic phosphatase Cdc14. At anaphase onset, the protease separase and Zds1 promote the downregulation of PP2ACdc55 phosphatase, which facilitates Cdk1-dependent phosphorylation of Net1 and provides the first wave of Cdc14 activity. Once Cdk1 activity starts to decline, the mitotic exit network (MEN) is activated to achieve full Cdc14 activation. Here we describe how the PP2ACdc55 phosphatase could act as a functional link between FEAR and MEN due to its action on Bfa1 and Mob1. We demonstrate that PP2ACdc55 regulates MEN activation by facilitating Cdc5- and Cdk1-dependent phosphorylation of Bfa1 and Mob1, respectively. Downregulation of PP2ACdc55 initiates MEN activity up to Cdc15 by Bfa1 inactivation. Surprisingly, the premature Bfa1 inactivation observed does not entail premature MEN activation, since an additional Cdk1-Clb2 inhibitory signal acting towards Dbf2-Mob1 activity restrains MEN activity until anaphase. In conclusion, we propose a clear picture of how PP2ACdc55 functions affect the regulation of various MEN components, contributing to mitotic exit. Cell cycle studies over the years have tried to elucidate the molecular mechanisms behind cell division, one of the most highly regulated of all cell processes, which ensures life in all organisms. Protein phosphorylation emerged as a key regulatory mechanism in the cell cycle. The highly conserved family of cyclin-dependent kinases, the Cdks, are considered the main component of the cell cycle control system. However, it has become clear that opposing phosphatases also play a key role in determining the phosphorylation state of the proteins. Cells enter mitosis when mitotic Cdk activity increases, having its pick of activity during metaphase. To exit mitosis, cells must coordinate chromosome segregation with Cdk inactivation processes involving the activation of protein phosphatases. Here we show that the phosphatase PP2A regulates the mitotic exit network (MEN) by counteracting the phosphorylation of Bfa1 and Mob1. Our findings provide new insights into the mechanism by which PP2A-Cdc55 functions affect the regulation of various MEN components that contribute to mitotic exit. The core signalling elements of the MEN, SIN and Hippo pathways are highly conserved. Therefore, studies of MEN regulation will contribute to our understanding of MEN-related pathways in other organisms.
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Affiliation(s)
- Barbara Baro
- Cell Cycle Group, Cancer Epigenetics and Biology Program (PEBC), Institut d'Investigacions Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Jose-Antonio Rodriguez-Rodriguez
- Cell Cycle Group, Cancer Epigenetics and Biology Program (PEBC), Institut d'Investigacions Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Ines Calabria
- Cell Cycle Group, Cancer Epigenetics and Biology Program (PEBC), Institut d'Investigacions Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - María Luisa Hernáez
- Unidad de Proteómica, Parque Científico de Madrid, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Concha Gil
- Unidad de Proteómica, Parque Científico de Madrid, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Ethel Queralt
- Cell Cycle Group, Cancer Epigenetics and Biology Program (PEBC), Institut d'Investigacions Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
- * E-mail:
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Mahmood SF, Gruel N, Chapeaublanc E, Lescure A, Jones T, Reyal F, Vincent-Salomon A, Raynal V, Pierron G, Perez F, Camonis J, Del Nery E, Delattre O, Radvanyi F, Bernard-Pierrot I. A siRNA screen identifies RAD21, EIF3H, CHRAC1 and TANC2 as driver genes within the 8q23, 8q24.3 and 17q23 amplicons in breast cancer with effects on cell growth, survival and transformation. Carcinogenesis 2013; 35:670-82. [PMID: 24148822 DOI: 10.1093/carcin/bgt351] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
RNA interference has boosted the field of functional genomics, by making it possible to carry out 'loss-of-function' screens in cultured cells. Here, we performed a small interfering RNA screening, in three breast cancer cell lines, for 101 candidate driver genes overexpressed in amplified breast tumors and belonging to eight amplicons on chromosomes 8q and 17q, investigating their role in cell survival/proliferation. This screening identified eight driver genes that were amplified, overexpressed and critical for breast tumor cell proliferation or survival. They included the well-described oncogenic driver genes for the 17q12 amplicon, ERBB2 and GRB7. Four of six other candidate driver genes-RAD21 and EIF3H, both on chromosome 8q23, CHRAC1 on chromosome 8q24.3 and TANC2 on chromosome 17q23-were confirmed to be driver genes regulating the proliferation/survival of clonogenic breast cancer cells presenting an amplification of the corresponding region. Indeed, knockdown of the expression of these genes decreased cell viability, through both cell cycle arrest and apoptosis induction, and inhibited the formation of colonies in anchorage-independent conditions, in soft agar. Strategies for inhibiting the expression of these genes or the function of the proteins they encode are therefore of potential value for the treatment of breast cancers presenting amplifications of the corresponding genomic region.
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Jin Y, Da W. Screening of key genes in gastric cancer with DNA microarray analysis. Eur J Med Res 2013; 18:37. [PMID: 24093889 PMCID: PMC3852022 DOI: 10.1186/2047-783x-18-37] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 09/05/2013] [Indexed: 12/23/2022] Open
Abstract
Background The aim of this study was to identify key genes and novel potential therapeutic targets related to gastric cancer (GC) by comparing cancer tissue samples and healthy control samples using DNA microarray analysis. Methods Microarray data set GSE19804 was downloaded from Gene Expression Omnibus. Preprocessing and differential analysis were conducted with of R statistical software packages, and a number of differentially expressed genes (DEGs) were obtained. Cluster analysis was also done with gene expression values. Functional enrichment analysis was performed for all the DEGs with DAVID tools. The significantly up- and downregulated genes were selected out and their interactors were retrieved with STRING and HitPredict, followed by construction of networks. For all the genes in the two networks, GeneCodis was chosen for gene function annotation. Results A total of 638 DEGs were identified, and we found that SPP1 and FABP4 were the markedly up- and downregulated genes, respectively. Cell cycle and regulation of proliferation were the most significantly overrepresented functional terms in up- and downregulated genes. In addition, extracellular matrix–receptor interaction was found to be significant in the SPP1-included interaction network. Conclusions A range of DEGs were obtained for GC. These genes not only provided insights into the pathogenesis of GC but also could develop into biomarkers for diagnosis or treatment.
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Affiliation(s)
- Yong Jin
- Department of gastroenterology, The 6th People's Hospital affiliated to Shanghai Jiaotong University, No, 600 Yishan Road, Shanghai 200233, China.
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Sajesh BV, Lichtensztejn Z, McManus KJ. Sister chromatid cohesion defects are associated with chromosome instability in Hodgkin lymphoma cells. BMC Cancer 2013; 13:391. [PMID: 23962039 PMCID: PMC3751861 DOI: 10.1186/1471-2407-13-391] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 08/19/2013] [Indexed: 12/25/2022] Open
Abstract
Background Chromosome instability manifests as an abnormal chromosome complement and is a pathogenic event in cancer. Although a correlation between abnormal chromosome numbers and cancer exist, the underlying mechanisms that cause chromosome instability are poorly understood. Recent data suggests that aberrant sister chromatid cohesion causes chromosome instability and thus contributes to the development of cancer. Cohesion normally functions by tethering nascently synthesized chromatids together to prevent premature segregation and thus chromosome instability. Although the prevalence of aberrant cohesion has been reported for some solid tumors, its prevalence within liquid tumors is unknown. Consequently, the current study was undertaken to evaluate aberrant cohesion within Hodgkin lymphoma, a lymphoid malignancy that frequently exhibits chromosome instability. Methods Using established cytogenetic techniques, the prevalence of chromosome instability and aberrant cohesion was examined within mitotic spreads generated from five commonly employed Hodgkin lymphoma cell lines (L-1236, KM-H2, L-428, L-540 and HDLM-2) and a lymphocyte control. Indirect immunofluorescence and Western blot analyses were performed to evaluate the localization and expression of six critical proteins involved in the regulation of sister chromatid cohesion. Results We first confirmed that all five Hodgkin lymphoma cell lines exhibited chromosome instability relative to the lymphocyte control. We then determined that each Hodgkin lymphoma cell line exhibited cohesion defects that were subsequently classified into mild, moderate or severe categories. Surprisingly, ~50% of the mitotic spreads generated from L-540 and HDLM-2 harbored cohesion defects. To gain mechanistic insight into the underlying cause of the aberrant cohesion we examined the localization and expression of six critical proteins involved in cohesion. Although all proteins produced the expected nuclear localization pattern, striking differences in RAD21 expression was observed: RAD21 expression was lowest in L-540 and highest within HDLM-2. Conclusion We conclude that aberrant cohesion is a common feature of all five Hodgkin lymphoma cell lines evaluated. We further conclude that aberrant RAD21 expression is a strong candidate to underlie aberrant cohesion, chromosome instability and contribute to the development of the disease. Our findings support a growing body of evidence suggesting that cohesion defects and aberrant RAD21 expression are pathogenic events that contribute to tumor development.
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Affiliation(s)
- Babu V Sajesh
- Manitoba Institute of Cell Biology and the Department of Biochemistry & Medical Genetics, University of Manitoba, ON6010 - 675 McDermot Avenue, Winnipeg, Manitoba MB R3E 0V9, Canada
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Yadav S, Sehrawat A, Eroglu Z, Somlo G, Hickey R, Yadav S, Liu X, Awasthi YC, Awasthi S. Role of SMC1 in overcoming drug resistance in triple negative breast cancer. PLoS One 2013; 8:e64338. [PMID: 23717600 PMCID: PMC3661439 DOI: 10.1371/journal.pone.0064338] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 04/12/2013] [Indexed: 11/30/2022] Open
Abstract
Triple-negative breast cancer (TNBC) is one of the hardest subtypes of breast cancer to treat due to the heterogeneity of the disease and absence of well-defined molecular targets. Emerging evidence has shown the role of cohesin in the formation and progression of various cancers including colon and lung cancer but the role of cohesin in breast cancer remains elusive. Our data showed that structural maintenance of chromosome 1 (SMC1), a subunit of the cohesin protein complex, is differentially overexpressed both at RNA and protein level in a panel of TNBC cell lines as compared to normal epithelial or luminal breast cancer cells, suggesting that the amplified product of this normal gene may play role in tumorigenesis in TNBC. In addition, our results show that induced overexpression of SMC1 through transient transfection enhanced cell migration and anchorage independent growth while its suppression with targeted small interfering RNA (siRNA) reduced the migration ability of TNBC cells. Increased expression of SMC1 also lead to increase in the mesenchymal marker vimentin and decrease in the normal epithelial marker, E-cadherin. Immunocytochemical studies along with flow cytometry and cell fractionation showed the localization of SMC1 in the nucleus, cytoplasm and also in the plasma membrane. The knockdown of SMC1 by siRNA sensitized the TNBC cells towards a PARP inhibitor (ABT-888) and IC50 was approximately three fold less than ABT-888 alone. The cytotoxic effect of combination of SMC1 suppression and ABT-888 was also confirmed by the colony propagation assay. Taken together, these studies report for the first time that SMC1 is overexpressed in TNBC cells where it plays a role in cell migration and drug sensitivity, and thus provides a potential therapeutic target for this highly invasive breast cancer subtype.
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Affiliation(s)
- Sushma Yadav
- Department of Diabetes, Endocrinology and Metabolic Diseases, City of Hope Comprehensive Cancer Center, Duarte, California, United States of America.
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O'Neil NJ, van Pel DM, Hieter P. Synthetic lethality and cancer: cohesin and PARP at the replication fork. Trends Genet 2013; 29:290-7. [PMID: 23333522 PMCID: PMC3868440 DOI: 10.1016/j.tig.2012.12.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 11/28/2012] [Accepted: 12/14/2012] [Indexed: 01/19/2023]
Abstract
Cohesins are mutated in a significant number of tumors of various types making them attractive targets for chemotherapeutic intervention. However, cohesins have a spectrum of cellular roles including sister chromatid cohesion, transcription, replication, and repair. Which of these roles are central to cancer biology and which roles can be exploited for therapeutic intervention? Genetic interaction networks in yeast have identified synthetic lethal interactions between mutations in cohesin and replication fork mediators. These interactions are conserved in worms and in human cells suggesting that inhibition of replication fork stability mediators such as poly (ADP-ribose) polymerase (PARP) could result in the specific killing of tumors with cohesin mutations. These findings also highlight the utility of genetic interaction networks in model organisms for the identification of clinically relevant interactions. Here, we review this type of approach, emphasizing the power of synthetic lethal interactions to reveal new avenues for developing cancer therapeutics.
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Affiliation(s)
- Nigel J O'Neil
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
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Sánchez-Peña ML, Isaza CE, Pérez-Morales J, Rodríguez-Padilla C, Castro JM, Cabrera-Ríos M. Identification of potential biomarkers from microarray experiments using multiple criteria optimization. Cancer Med 2013; 2:253-65. [PMID: 23634293 PMCID: PMC3639664 DOI: 10.1002/cam4.69] [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: 01/23/2012] [Revised: 01/23/2013] [Accepted: 01/24/2013] [Indexed: 12/14/2022] Open
Abstract
Microarray experiments are capable of determining the relative expression of tens of thousands of genes simultaneously, thus resulting in very large databases. The analysis of these databases and the extraction of biologically relevant knowledge from them are challenging tasks. The identification of potential cancer biomarker genes is one of the most important aims for microarray analysis and, as such, has been widely targeted in the literature. However, identifying a set of these genes consistently across different experiments, researches, microarray platforms, or cancer types is still an elusive endeavor. Besides the inherent difficulty of the large and nonconstant variability in these experiments and the incommensurability between different microarray technologies, there is the issue of the users having to adjust a series of parameters that significantly affect the outcome of the analyses and that do not have a biological or medical meaning. In this study, the identification of potential cancer biomarkers from microarray data is casted as a multiple criteria optimization (MCO) problem. The efficient solutions to this problem, found here through data envelopment analysis (DEA), are associated to genes that are proposed as potential cancer biomarkers. The method does not require any parameter adjustment by the user, and thus fosters repeatability. The approach also allows the analysis of different microarray experiments, microarray platforms, and cancer types simultaneously. The results include the analysis of three publicly available microarray databases related to cervix cancer. This study points to the feasibility of modeling the selection of potential cancer biomarkers from microarray data as an MCO problem and solve it using DEA. Using MCO entails a new optic to the identification of potential cancer biomarkers as it does not require the definition of a threshold value to establish significance for a particular gene and the selection of a normalization procedure to compare different experiments is no longer necessary.
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Affiliation(s)
- Matilde L Sánchez-Peña
- Bio IE Lab, Industrial Engineering Department, University of Puerto Rico at Mayaguez, Mayagüez, Puerto Rico
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Aure MR, Steinfeld I, Baumbusch LO, Liestøl K, Lipson D, Nyberg S, Naume B, Sahlberg KK, Kristensen VN, Børresen-Dale AL, Lingjærde OC, Yakhini Z. Identifying in-trans process associated genes in breast cancer by integrated analysis of copy number and expression data. PLoS One 2013; 8:e53014. [PMID: 23382830 PMCID: PMC3559658 DOI: 10.1371/journal.pone.0053014] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 11/22/2012] [Indexed: 12/12/2022] Open
Abstract
Genomic copy number alterations are common in cancer. Finding the genes causally implicated in oncogenesis is challenging because the gain or loss of a chromosomal region may affect a few key driver genes and many passengers. Integrative analyses have opened new vistas for addressing this issue. One approach is to identify genes with frequent copy number alterations and corresponding changes in expression. Several methods also analyse effects of transcriptional changes on known pathways. Here, we propose a method that analyses in-cis correlated genes for evidence of in-trans association to biological processes, with no bias towards processes of a particular type or function. The method aims to identify cis-regulated genes for which the expression correlation to other genes provides further evidence of a network-perturbing role in cancer. The proposed unsupervised approach involves a sequence of statistical tests to systematically narrow down the list of relevant genes, based on integrative analysis of copy number and gene expression data. A novel adjustment method handles confounding effects of co-occurring copy number aberrations, potentially a large source of false positives in such studies. Applying the method to whole-genome copy number and expression data from 100 primary breast carcinomas, 6373 genes were identified as commonly aberrant, 578 were highly in-cis correlated, and 56 were in addition associated in-trans to biological processes. Among these in-trans process associated and cis-correlated (iPAC) genes, 28% have previously been reported as breast cancer associated, and 64% as cancer associated. By combining statistical evidence from three separate subanalyses that focus respectively on copy number, gene expression and the combination of the two, the proposed method identifies several known and novel cancer driver candidates. Validation in an independent data set supports the conclusion that the method identifies genes implicated in cancer.
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Affiliation(s)
- Miriam Ragle Aure
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway
- K. G. Jebsen Centre for Breast Cancer Research, Institute for Clinical Medicine, University of Oslo, Oslo, Norway
| | - Israel Steinfeld
- Laboratory of Computational Biology, Computer Science Department, Israel Institute of Technology, Haifa, Israel
| | - Lars Oliver Baumbusch
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway
| | - Knut Liestøl
- Biomedical Informatics Lab, Department of Computer Science, University of Oslo, Oslo, Norway
- Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
| | - Doron Lipson
- Laboratory of Computational Biology, Computer Science Department, Israel Institute of Technology, Haifa, Israel
| | - Sandra Nyberg
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway
- K. G. Jebsen Centre for Breast Cancer Research, Institute for Clinical Medicine, University of Oslo, Oslo, Norway
| | - Bjørn Naume
- Division of Cancer Medicine and Radiotherapy, Department of Oncology, Oslo University Hospital Radiumhospitalet, Oslo, Norway
| | - Kristine Kleivi Sahlberg
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway
- K. G. Jebsen Centre for Breast Cancer Research, Institute for Clinical Medicine, University of Oslo, Oslo, Norway
| | - Vessela N. Kristensen
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway
- K. G. Jebsen Centre for Breast Cancer Research, Institute for Clinical Medicine, University of Oslo, Oslo, Norway
- Institute for Clinical Epidemiology and Molecular Biology (EpiGen) Akershus University Hospital, Akershus, Norway
| | - Anne-Lise Børresen-Dale
- Department of Genetics, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Oslo, Norway
- K. G. Jebsen Centre for Breast Cancer Research, Institute for Clinical Medicine, University of Oslo, Oslo, Norway
| | - Ole Christian Lingjærde
- K. G. Jebsen Centre for Breast Cancer Research, Institute for Clinical Medicine, University of Oslo, Oslo, Norway
- Biomedical Informatics Lab, Department of Computer Science, University of Oslo, Oslo, Norway
- Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
- * E-mail: (OCL); (ZY)
| | - Zohar Yakhini
- Laboratory of Computational Biology, Computer Science Department, Israel Institute of Technology, Haifa, Israel
- Agilent Laboratories, Tel Aviv, Israel
- * E-mail: (OCL); (ZY)
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McEwan MV, Eccles MR, Horsfield JA. Cohesin is required for activation of MYC by estradiol. PLoS One 2012; 7:e49160. [PMID: 23145106 PMCID: PMC3493498 DOI: 10.1371/journal.pone.0049160] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 10/09/2012] [Indexed: 12/13/2022] Open
Abstract
Cohesin is best known as a multi-subunit protein complex that holds together replicated sister chromatids from S phase until G2. Cohesin also has an important role in the regulation of gene expression. We previously demonstrated that the cohesin complex positively regulates expression of the oncogene MYC. Cell proliferation driven by MYC contributes to many cancers, including breast cancer. The MYC oncogene is estrogen-responsive and a transcriptional target of estrogen receptor alpha (ERα). Estrogen-induced cohesin binding sites coincide with ERα binding at the MYC locus, raising the possibility that cohesin and ERα combine actions to regulate MYC transcription. The objective of this study was to investigate a putative role for cohesin in estrogen induction of MYC expression. We found that siRNA-targeted depletion of a cohesin subunit, RAD21, decreased MYC expression in ER-positive (MCF7 and T47D) and ER-negative (MDA-MB-231) breast cancer cell lines. In addition, RAD21 depletion blocked estradiol-mediated activation of MYC in ER-positive cell lines, and decreased ERα binding to estrogen response elements (EREs) upstream of MYC, without affecting total ERα levels. Treatment of MCF7 cells with estradiol caused enrichment of RAD21 binding at upstream enhancers and at the P2 promoter of MYC. Enriched binding at all sites, except the P2 promoter, was dependent on ERα. Since RAD21 depletion did not affect transcription driven by an exogenous reporter construct containing a naked ERE, chromatin-based mechanisms are likely to be involved in cohesin-dependent MYC transcription. This study demonstrates that ERα activation of MYC can be modulated by cohesin. Together, these results demonstrate a novel role for cohesin in estrogen-mediated regulation of MYC and the first evidence that cohesin plays a role in ERα binding.
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Affiliation(s)
- Miranda V. McEwan
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Michael R. Eccles
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Julia A. Horsfield
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
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Horsfield JA, Print CG, Mönnich M. Diverse developmental disorders from the one ring: distinct molecular pathways underlie the cohesinopathies. Front Genet 2012; 3:171. [PMID: 22988450 PMCID: PMC3439829 DOI: 10.3389/fgene.2012.00171] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 08/17/2012] [Indexed: 11/13/2022] Open
Abstract
The multi-subunit protein complex, cohesin, is responsible for sister chromatid cohesion during cell division. The interaction of cohesin with DNA is controlled by a number of additional regulatory proteins. Mutations in cohesin, or its regulators, cause a spectrum of human developmental syndromes known as the “cohesinopathies.” Cohesinopathy disorders include Cornelia de Lange Syndrome and Roberts Syndrome. The discovery of novel roles for chromatid cohesion proteins in regulating gene expression led to the idea that cohesinopathies are caused by dysregulation of multiple genes downstream of mutations in cohesion proteins. Consistent with this idea, Drosophila, mouse, and zebrafish cohesinopathy models all show altered expression of developmental genes. However, there appears to be incomplete overlap among dysregulated genes downstream of mutations in different components of the cohesion apparatus. This is surprising because mutations in all cohesion proteins would be predicted to affect cohesin’s roles in cell division and gene expression in similar ways. Here we review the differences and similarities between genetic pathways downstream of components of the cohesion apparatus, and discuss how such differences might arise, and contribute to the spectrum of cohesinopathy disorders. We propose that mutations in different elements of the cohesion apparatus have distinct developmental outcomes that can be explained by sometimes subtly different molecular effects.
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Affiliation(s)
- Julia A Horsfield
- Department of Pathology, Dunedin School of Medicine, The University of Otago Dunedin, New Zealand
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Molecular resistance fingerprint of pemetrexed and platinum in a long-term survivor of mesothelioma. PLoS One 2012; 7:e40521. [PMID: 22905093 PMCID: PMC3414492 DOI: 10.1371/journal.pone.0040521] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2011] [Accepted: 06/11/2012] [Indexed: 12/29/2022] Open
Abstract
Background Pemetrexed, a multi-folate inhibitor combined with a platinum compound is the first-line treatment of malignant mesothelioma, but median survival is still one year. Intrinsic and acquired resistance to pemetrexed is common, but its biological basis is obscure. Here we report for the first time a genome-wide profile of acquired resistance in the tumour from an exceptional case with advanced pleural mesothelioma and almost six years survival after 39 cycles of second-line pemetrexed/carboplatin treatment. Methodology and Principal Findings Genome-wide analysis with Illumina BeadChip Kit of 25,000 genes was performed on mRNA from pre-treatment and post-resistance biopsies from this individual as well on case and control samples from our previously published study (in total 17 samples). Cell specific expression of proteins encoded by selected genes were analysed by immunohistochemistry. Serial serum levels of CA125, CYFRA21-1 and SMRP levels were examined. TS protein, the main target of pemetrexed was overexpressed. Proteins and genes related to DNA damage response, elongation and telomere extension and repair related directly and indirectly to platinum resistance were overexpressed, as the CHK1 protein and the genes CHEK2, LIG3, POLD1, POLA2, FANCD2, PRPF19, RECQ5 respectively, the last two not previously described in mesothelioma. We observed a down-regulation of leukocyte transendothelial migration and cell adhesion molecules pathways. Silencing of NT5C in two mesothelioma cell lines did not sensitize the cells to Pemetrexed. Proposed resistance markers are TS, KRT7/ CK7, TYMP/ thymidine phosphorylase and down-regulated SPARCL1 and CDKN1B. Moreover, comparison of the primary expression of the sensitive versus a primary resistant case showed multi-fold overexpressed DNA repair, cell cycle, cytokinesis, and spindle formation in the latter. Serum CA125 and SMRP reflected the clinical and radiological course and tumour burden. Conclusions Genome-wide microarray of mesothelioma pre- and post-resistance biopsies indicated a novel resistance signature to pemetrexed/carboplatin that deserve validation in a larger cohort.
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Supernat A, Lapińska-Szumczyk S, Sawicki S, Wydra D, Biernat W, Zaczek AJ. Deregulation of RAD21 and RUNX1 expression in endometrial cancer. Oncol Lett 2012. [PMID: 23205091 DOI: 10.3892/ol.2012.794] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cohesins and cohesin-regulated genes are deregulated in numerous types of human cancer. However, data concerning their status and role in endometrial cancer are scarce. This study aimed to determine the clinical significance of double-strand-break repair protein rad21 homolog (RAD21) and runt-related transcription factor 1 (RUNX1) gene dosage and mRNA expression in endometrial cancer. RAD21 is a component of the cohesin complex, crucial for chromosome segregation and DNA repair. RUNX1 is the transcription factor implicated in RAD21 regulation. The study group included 144 endometrial cancer patients. RAD21 and RUNX1 expression profiles were measured by reverse-transcription quantitative PCR. RAD21 gene dosage was determined by quantitative PCR. RAD21 gene dosage was associated with RAD21 mRNA expression (ϱ=0.22; p=0.009). Furthermore, RAD21 expression strongly correlated with RUNX1 expression (ϱ=0.43; p<0.0000001). Increased RAD21 gene dosage correlated with more advanced tumor stage (p=0.021), higher grade (p=0.021), cervical involvement (p=0.01) and the absence of obesity (p=0.025), while RAD21 mRNA expression correlatd with cervical involvement (p=0.027). The mRNA expression of RAD21 and RUNX1 was found to be deregulated and co-dependent in endometrial cancer. RAD21 gene dosage is associated with unfavorable tumor characteristics. However, elucidating the role of these molecular markers in endometrial oncogenesis requires further investigation, including functional studies and survival analysis.
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Affiliation(s)
- Anna Supernat
- Department of Medical Biotechnology, Intercollegiate Faculty of Biotechnology,University of Gdańsk and Medical University of Gdańsk, 80-211 Gdańsk
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Yan M, Xu H, Waddell N, Shield-Artin K, Haviv I, McKay MJ, Fox SB. Enhanced RAD21 cohesin expression confers poor prognosis in BRCA2 and BRCAX, but not BRCA1 familial breast cancers. Breast Cancer Res 2012; 14:R69. [PMID: 22537934 PMCID: PMC3446404 DOI: 10.1186/bcr3176] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 02/26/2012] [Accepted: 04/26/2012] [Indexed: 12/17/2022] Open
Abstract
INTRODUCTION The RAD21 gene encodes a key component of the cohesin complex, which is essential for chromosome segregation, and together with BRCA1 and BRCA2, for high-fidelity DNA repair by homologous recombination. Although its expression correlates with early relapse and treatment resistance in sporadic breast cancers, it is unclear whether familial breast cancers behave in a similar manner. METHODS We performed an immunohistochemical analysis of RAD21 expression in a cohort of 94 familial breast cancers (28 BRCA1, 27 BRCA2, and 39 BRCAX) and correlated these data with genotype and clinicopathologic parameters, including survival. In these cancers, we also correlated RAD21 expression with genomic expression profiling and gene copy-number changes and miRNAs predicted to target RAD21. RESULTS No significant differences in nuclear RAD21 expression were observed between BRCA1 (12 (43%) of 28), BRCA2 (12 (44%) of 27), and BRCAX cancers (12 (33%) of 39 (p = 0.598). No correlation was found between RAD21 expression and grade, size, or lymph node, ER, or HER2 status (all P > 0.05). As for sporadic breast cancers, RAD21 expression correlated with shorter survival in grade 3 (P = 0.009) and but not in grade 1 (P = 0.065) or 2 cancers (P = 0.090). Expression of RAD21 correlated with poorer survival in patients treated with chemotherapy (P = 0.036) but not with hormonal therapy (P = 0.881). RAD21 expression correlated with shorter survival in BRCA2 (P = 0.006) and BRCAX (P = 0.008), but not BRCA1 cancers (P = 0.713). Changes in RAD21 mRNA were reflected by genomic changes in DNA copy number (P < 0.001) and by RAD21 protein expression, as assessed with immunohistochemistry (P = 0.047). High RAD21 expression was associated with genomic instability, as assessed by the total number of base pairs affected by genomic change (P = 0.048). Of 15 miRNAs predicted to target RAD21, mir-299-5p inversely correlated with RAD21 expression (P = 0.002). CONCLUSIONS Potential use of RAD21 as a predictive and prognostic marker in familial breast cancers is hence feasible and may therefore take into account the patient's BRCA1/2 mutation status.
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Affiliation(s)
- Max Yan
- Department of Anatomical Pathology, Prince of Wales Hospital, Barker Street, Randwick, 2031, Australia
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64
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Fan B, Dachrut S, Coral H, Yuen ST, Chu KM, Law S, Zhang L, Ji J, Leung SY, Chen X. Integration of DNA copy number alterations and transcriptional expression analysis in human gastric cancer. PLoS One 2012; 7:e29824. [PMID: 22539939 PMCID: PMC3335165 DOI: 10.1371/journal.pone.0029824] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 12/03/2011] [Indexed: 12/16/2022] Open
Abstract
Background Genomic instability with frequent DNA copy number alterations is one of the key hallmarks of carcinogenesis. The chromosomal regions with frequent DNA copy number gain and loss in human gastric cancer are still poorly defined. It remains unknown how the DNA copy number variations contributes to the changes of gene expression profiles, especially on the global level. Principal Findings We analyzed DNA copy number alterations in 64 human gastric cancer samples and 8 gastric cancer cell lines using bacterial artificial chromosome (BAC) arrays based comparative genomic hybridization (aCGH). Statistical analysis was applied to correlate previously published gene expression data obtained from cDNA microarrays with corresponding DNA copy number variation data to identify candidate oncogenes and tumor suppressor genes. We found that gastric cancer samples showed recurrent DNA copy number variations, including gains at 5p, 8q, 20p, 20q, and losses at 4q, 9p, 18q, 21q. The most frequent regions of amplification were 20q12 (7/72), 20q12–20q13.1 (12/72), 20q13.1–20q13.2 (11/72) and 20q13.2–20q13.3 (6/72). The most frequent deleted region was 9p21 (8/72). Correlating gene expression array data with aCGH identified 321 candidate oncogenes, which were overexpressed and showed frequent DNA copy number gains; and 12 candidate tumor suppressor genes which were down-regulated and showed frequent DNA copy number losses in human gastric cancers. Three networks of significantly expressed genes in gastric cancer samples were identified by ingenuity pathway analysis. Conclusions This study provides insight into DNA copy number variations and their contribution to altered gene expression profiles during human gastric cancer development. It provides novel candidate driver oncogenes or tumor suppressor genes for human gastric cancer, useful pathway maps for the future understanding of the molecular pathogenesis of this malignancy, and the construction of new therapeutic targets.
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Affiliation(s)
- Biao Fan
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, United States of America
- Department of Surgery, Beijing Cancer Hospital & Institute, Peking University School of Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Beijing, China
| | - Somkid Dachrut
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, United States of America
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Ho Coral
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, United States of America
| | - Siu Tsan Yuen
- Department of Pathology, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong
| | - Kent Man Chu
- Department of Surgery; The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong
| | - Simon Law
- Department of Surgery; The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong
| | - Lianhai Zhang
- Department of Surgery, Beijing Cancer Hospital & Institute, Peking University School of Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Beijing, China
| | - Jiafu Ji
- Department of Surgery, Beijing Cancer Hospital & Institute, Peking University School of Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Beijing, China
- * E-mail: (XC); (SYL); (JFJ)
| | - Suet Yi Leung
- Department of Pathology, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong
- * E-mail: (XC); (SYL); (JFJ)
| | - Xin Chen
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, United States of America
- * E-mail: (XC); (SYL); (JFJ)
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Abstract
The cohesin complex, named for its key role in sister chromatid cohesion, also plays critical roles in gene regulation and DNA repair. It performs all three functions in single cell eukaryotes such as yeasts, and in higher organisms such as man. Minor disruption of cohesin function has significant consequences for human development, even in the absence of measurable effects on chromatid cohesion or chromosome segregation. Here we survey the roles of cohesin in gene regulation and DNA repair, and how these functions vary from yeast to man.
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Affiliation(s)
- Dale Dorsett
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, MO 63104, USA.
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66
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Wu N, Yu H. The Smc complexes in DNA damage response. Cell Biosci 2012; 2:5. [PMID: 22369641 PMCID: PMC3329402 DOI: 10.1186/2045-3701-2-5] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 02/27/2012] [Indexed: 02/03/2023] Open
Abstract
The structural maintenance of chromosomes (Smc) proteins regulate nearly all aspects of chromosome biology and are critical for genomic stability. In eukaryotes, six Smc proteins form three heterodimers--Smc1/3, Smc2/4, and Smc5/6--which together with non-Smc proteins form cohesin, condensin, and the Smc5/6 complex, respectively. Cohesin is required for proper chromosome segregation. It establishes and maintains sister-chromatid cohesion until all sister chromatids achieve bipolar attachment to the mitotic spindle. Condensin mediates chromosome condensation during mitosis. The Smc5/6 complex has multiple roles in DNA repair. In addition to their major functions in chromosome cohesion and condensation, cohesin and condensin also participate in the cellular DNA damage response. Here we review recent progress on the functions of all three Smc complexes in DNA repair and their cell cycle regulation by posttranslational modifications, such as acetylation, phosphorylation, and sumoylation. An in-depth understanding of the mechanisms by which these complexes promote DNA repair and genomic stability may help us to uncover the molecular basis of genomic instability in human cancers and devise ways that exploit this instability to treat cancers.
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Affiliation(s)
- Nan Wu
- Department of Pharmacology, Howard Hughes Medical Institute, 6001 Forest Park Road, Dallas, TX 75390, USA.
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Rhodes JM, McEwan M, Horsfield JA. Gene regulation by cohesin in cancer: is the ring an unexpected party to proliferation? Mol Cancer Res 2011; 9:1587-607. [PMID: 21940756 DOI: 10.1158/1541-7786.mcr-11-0382] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cohesin is a multisubunit protein complex that plays an integral role in sister chromatid cohesion, DNA repair, and meiosis. Of significance, both over- and underexpression of cohesin are associated with cancer. It is generally believed that cohesin dysregulation contributes to cancer by leading to aneuploidy or chromosome instability. For cancers with loss of cohesin function, this idea seems plausible. However, overexpression of cohesin in cancer appears to be more significant for prognosis than its loss. Increased levels of cohesin subunits correlate with poor prognosis and resistance to drug, hormone, and radiation therapies. However, if there is sufficient cohesin for sister chromatid cohesion, overexpression of cohesin subunits should not obligatorily lead to aneuploidy. This raises the possibility that excess cohesin promotes cancer by alternative mechanisms. Over the last decade, it has emerged that cohesin regulates gene transcription. Recent studies have shown that gene regulation by cohesin contributes to stem cell pluripotency and cell differentiation. Of importance, cohesin positively regulates the transcription of genes known to be dysregulated in cancer, such as Runx1, Runx3, and Myc. Furthermore, cohesin binds with estrogen receptor α throughout the genome in breast cancer cells, suggesting that it may be involved in the transcription of estrogen-responsive genes. Here, we will review evidence supporting the idea that the gene regulation function of cohesin represents a previously unrecognized mechanism for the development of cancer.
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Affiliation(s)
- Jenny M Rhodes
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
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68
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Abstract
Cohesin is a conserved multisubunit protein complex with diverse cellular roles, making key contributions to the coordination of chromosome segregation, the DNA damage response and chromatin regulation by epigenetic mechanisms. Much has been learned in recent years about the roles of cohesin in a physiological context, whereas its potential and emerging role in tumour initiation and/or progression has received relatively little attention. In this Opinion article we examine how cohesin deregulation could contribute to cancer development on the basis of its physiological roles.
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Affiliation(s)
- Huiling Xu
- Research Division, Peter MacCallum Cancer Centre, Melbourne, Victoria 8006, Australia
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69
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Bekhouche I, Finetti P, Adelaïde J, Ferrari A, Tarpin C, Charafe-Jauffret E, Charpin C, Houvenaeghel G, Jacquemier J, Bidaut G, Birnbaum D, Viens P, Chaffanet M, Bertucci F. High-resolution comparative genomic hybridization of inflammatory breast cancer and identification of candidate genes. PLoS One 2011; 6:e16950. [PMID: 21339811 PMCID: PMC3037286 DOI: 10.1371/journal.pone.0016950] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Accepted: 01/18/2011] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Inflammatory breast cancer (IBC) is an aggressive form of BC poorly defined at the molecular level. We compared the molecular portraits of 63 IBC and 134 non-IBC (nIBC) clinical samples. METHODOLOGY/FINDINGS Genomic imbalances of 49 IBCs and 124 nIBCs were determined using high-resolution array-comparative genomic hybridization, and mRNA expression profiles of 197 samples using whole-genome microarrays. Genomic profiles of IBCs were as heterogeneous as those of nIBCs, and globally relatively close. However, IBCs showed more frequent "complex" patterns and a higher percentage of genes with CNAs per sample. The number of altered regions was similar in both types, although some regions were altered more frequently and/or with higher amplitude in IBCs. Many genes were similarly altered in both types; however, more genes displayed recurrent amplifications in IBCs. The percentage of genes whose mRNA expression correlated with CNAs was similar in both types for the gained genes, but ∼7-fold lower in IBCs for the lost genes. Integrated analysis identified 24 potential candidate IBC-specific genes. Their combined expression accurately distinguished IBCs and nIBCS in an independent validation set, and retained an independent prognostic value in a series of 1,781 nIBCs, reinforcing the hypothesis for a link with IBC aggressiveness. Consistent with the hyperproliferative and invasive phenotype of IBC these genes are notably involved in protein translation, cell cycle, RNA processing and transcription, metabolism, and cell migration. CONCLUSIONS Our results suggest a higher genomic instability of IBC. We established the first repertory of DNA copy number alterations in this tumor, and provided a list of genes that may contribute to its aggressiveness and represent novel therapeutic targets.
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Affiliation(s)
- Ismahane Bekhouche
- Marseille Cancer Research Center (CRCM), UMR891 Inserm, Institut Paoli-Calmettes (IPC), Department of Molecular Oncology, Marseille, France
| | - Pascal Finetti
- Marseille Cancer Research Center (CRCM), UMR891 Inserm, Institut Paoli-Calmettes (IPC), Department of Molecular Oncology, Marseille, France
| | - José Adelaïde
- Marseille Cancer Research Center (CRCM), UMR891 Inserm, Institut Paoli-Calmettes (IPC), Department of Molecular Oncology, Marseille, France
| | - Anthony Ferrari
- Marseille Cancer Research Center (CRCM), UMR891 Inserm, Institut Paoli-Calmettes (IPC), Department of Molecular Oncology, Marseille, France
| | - Carole Tarpin
- Department of Medical Oncology, Institut Paoli-Calmettes (IPC), Marseille, France
| | - Emmanuelle Charafe-Jauffret
- Marseille Cancer Research Center (CRCM), UMR891 Inserm, Institut Paoli-Calmettes (IPC), Department of Molecular Oncology, Marseille, France
- Université de la Méditerranée, Marseille, France
- Department of BioPathology, Institut Paoli-Calmettes (IPC), Marseille, France
| | - Colette Charpin
- Université de la Méditerranée, Marseille, France
- Department of Pathology, Hôpital Nord, Marseille, France
| | | | - Jocelyne Jacquemier
- Marseille Cancer Research Center (CRCM), UMR891 Inserm, Institut Paoli-Calmettes (IPC), Department of Molecular Oncology, Marseille, France
- Department of BioPathology, Institut Paoli-Calmettes (IPC), Marseille, France
| | - Ghislain Bidaut
- Bioinformatics, Marseille Cancer Research Center (CRCM), Marseille, France
| | - Daniel Birnbaum
- Marseille Cancer Research Center (CRCM), UMR891 Inserm, Institut Paoli-Calmettes (IPC), Department of Molecular Oncology, Marseille, France
| | - Patrice Viens
- Department of Medical Oncology, Institut Paoli-Calmettes (IPC), Marseille, France
- Université de la Méditerranée, Marseille, France
| | - Max Chaffanet
- Marseille Cancer Research Center (CRCM), UMR891 Inserm, Institut Paoli-Calmettes (IPC), Department of Molecular Oncology, Marseille, France
| | - François Bertucci
- Marseille Cancer Research Center (CRCM), UMR891 Inserm, Institut Paoli-Calmettes (IPC), Department of Molecular Oncology, Marseille, France
- Department of Medical Oncology, Institut Paoli-Calmettes (IPC), Marseille, France
- Université de la Méditerranée, Marseille, France
- * E-mail:
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70
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Xu H, Yan M, Patra J, Natrajan R, Yan Y, Swagemakers S, Tomaszewski JM, Verschoor S, Millar EK, van der Spek P, Reis-Filho JS, Ramsay RG, O'Toole SA, McNeil CM, Sutherland RL, McKay MJ, Fox SB. Enhanced RAD21 cohesin expression confers poor prognosis and resistance to chemotherapy in high grade luminal, basal and HER2 breast cancers. Breast Cancer Res 2011; 13:R9. [PMID: 21255398 PMCID: PMC3109576 DOI: 10.1186/bcr2814] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 08/11/2010] [Accepted: 01/21/2011] [Indexed: 01/09/2023] Open
Abstract
INTRODUCTION RAD21 is a component of the cohesin complex, which is essential for chromosome segregation and error-free DNA repair. We assessed its prognostic and predictive power in a cohort of in situ and invasive breast cancers, and its effect on chemosensitivity in vitro. METHODS RAD21 immunohistochemistry was performed on 345 invasive and 60 pure in situ carcinomas. Integrated genomic and transcriptomic analyses were performed on a further 48 grade 3 invasive cancers. Chemosensitivity was assessed in breast cancer cell lines with an engineered spectrum of RAD21 expression. RESULTS RAD21 expression correlated with early relapse in all patients (hazard ratio (HR) 1.74, 95% confidence interval (CI) 1.06 to 2.86, P = 0.029). This was due to the effect of grade 3 tumors (but not grade 1 or 2) in which RAD21 expression correlated with early relapse in luminal (P = 0.040), basal (P = 0.018) and HER2 (P = 0.039) groups. In patients treated with chemotherapy, RAD21 expression was associated with shorter overall survival (P = 0.020). RAD21 mRNA expression correlated with DNA copy number, with amplification present in 32% (7/22) of luminal, 31% (4/13) of basal and 22% (2/9) of HER2 grade 3 cancers. Variations in RAD21 mRNA expression in the clinical samples were reflected in the gene expression data from 36 breast cancer cell lines. Knockdown of RAD21 in the MDA-MB-231 breast cancer cell line significantly enhanced sensitivity to cyclophosphamide, 5-fluorouracil and etoposide. The findings for the former two drugs recapitulated the clinical findings. CONCLUSIONS RAD21 expression confers poor prognosis and resistance to chemotherapy in high grade luminal, basal and HER2 breast cancers. RAD21 may be a novel therapeutic target.
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Affiliation(s)
- Huiling Xu
- Research Division, Peter MacCallum Cancer Centre, Locked Bag 1, A'Beckett Street, Melbourne, Vic 8006, Australia
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71
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Global transcriptional analysis of yeast cell death induced by mutation of sister chromatid cohesin. Comp Funct Genomics 2010:634283. [PMID: 18551189 PMCID: PMC2423420 DOI: 10.1155/2008/634283] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2007] [Revised: 03/31/2008] [Accepted: 04/22/2008] [Indexed: 02/05/2023] Open
Abstract
Cohesin is a protein complex that regulates sister chromatid cohesin during cell division. Malfunction in chromatid cohesin results in chromosome missegregation and aneuploidy. Here, we report that mutations of MCD1 and PDS5, two major components of cohesin in budding yeast, cause apoptotic cell death, which is characterized by externalization of phosphatidylserine at cytoplasmic membrane, chromatin condensation and fragmentation, and ROS production. Microarray analysis suggests that the cell death caused by mutation of MCD1 or PDS5 is due to the internal stress response, contrasting to the environmental or external stress response induced by external stimuli, such as hydrogen peroxide. A common feature shared by the internal stress response and external stress response is the response to stimulus, including response to DNA damage, mitochondria functions, and oxidative stress, which play an important role in yeast apoptotic cell death.
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72
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Mannini L, Menga S, Musio A. The expanding universe of cohesin functions: a new genome stability caretaker involved in human disease and cancer. Hum Mutat 2010; 31:623-30. [PMID: 20513141 DOI: 10.1002/humu.21252] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cohesin is responsible for sister chromatid cohesion, ensuring the correct chromosome segregation. Beyond this role, cohesin and regulatory cohesin genes seem to play a role in preserving genome stability and gene transcription regulation. DNA damage is thought to be a major culprit for many human diseases, including cancer. Our present knowledge of the molecular basis underlying genome instability is extremely limited. Mutations in cohesin genes cause human diseases such as Cornelia de Lange syndrome and Roberts syndrome/SC phocomelia, and all the cell lines derived from affected patients show genome instability. Cohesin mutations have also been identified in colorectal cancer. Here, we will discuss the human disorders caused by alterations of cohesin function, with emphasis on the emerging role of cohesin as a genome stability caretaker.
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Affiliation(s)
- Linda Mannini
- Istituto di Tecnologie Biomediche, Consiglio Nazionale delle Ricerche, Pisa, Italy
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73
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Sjögren C, Ström L. S-phase and DNA damage activated establishment of sister chromatid cohesion--importance for DNA repair. Exp Cell Res 2010; 316:1445-53. [PMID: 20043905 DOI: 10.1016/j.yexcr.2009.12.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 12/17/2009] [Accepted: 12/21/2009] [Indexed: 01/23/2023]
Abstract
By holding sister chromatids together from the moment of their formation until their separation at anaphase, the multi subunit protein complex Cohesin guarantees correct chromosome segregation. This S-phase established chromatid cohesion is also essential for repair of DNA double strand breaks (DSB) in postreplicative cells. In addition, Cohesin has to be recruited to a DSB, and new cohesion has to form in response to the damage for repair. When it became clear that cohesion is created de novo in response to DNA breaks, the term "damage induced cohesion" (DI-cohesion) was coined. It is now established that certain factors are needed for establishment of both S-phase and DI-cohesion, while others have been found to be unique for respective process. In addition, post-translational modifications of Cohesin components that are functionally important for cohesion formation, either during S-phase or in response to damage, have recently been identified. Here, we present and discuss the current models for establishment of S-phase and DI-cohesion in the context of their involvement in DSB repair.
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Affiliation(s)
- Camilla Sjögren
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
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74
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Røe OD, Anderssen E, Sandeck H, Christensen T, Larsson E, Lundgren S. Malignant pleural mesothelioma: genome-wide expression patterns reflecting general resistance mechanisms and a proposal of novel targets. Lung Cancer 2010; 67:57-68. [PMID: 19380173 DOI: 10.1016/j.lungcan.2009.03.016] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 01/12/2009] [Accepted: 03/17/2009] [Indexed: 10/20/2022]
Abstract
Malignant pleural mesothelioma is an asbestos-related multi-resistant tumour with increasing incidence worldwide. Well-characterized snap-frozen normal parietal, visceral pleura and mesothelioma samples were analysed with Affymetrix Human Genome U133 Plus 2.0 GeneChip oligoarray of 38500 genes. We discovered a close relation between gene profile and resistance towards topoisomerase poisons, alkylating agents, antitubulines, antifolates, platinum compounds and radiation therapy. Target genes of chemo- (e.g. TOP2A, BIRC5/Survivin and proteasome) and radiotherapy (e.g. BRCA2, FANCA, FANCD2, CCNB1 and RAD50) were significantly overexpressed. The Fanconi anemia/BRCA2 pathway, responsible for homologous recombination DNA repair appears as a key pathway in both chemo- and radio-resistance of mesothelioma. Leukocyte trans-endothelial migration gene down-regulation could partly explain resistance against immunological therapies. Gene expression features found in other resistant cancer types related to DNA repair and replication are shared by mesothelioma and could represent general features of tumour resistance. Targeted suppression of some of those key genes and pathways combined with chemotherapy or radiation could improve the outcome of mesothelioma therapy. We propose CHEK1, RAD21, FANCD2 and RAN as new co-targets for mesothelioma treatment. The pro-angiogenic AGGF1 mRNA and protein was highly overexpressed in all tumours and may serve as a target for anti-angiogenic treatment. Overexpression of NQO1 may render mesothelioma sensitive to the novel compound beta-Lapachone.
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75
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Nakamura Y, Migita T, Hosoda F, Okada N, Gotoh M, Arai Y, Fukushima M, Ohki M, Miyata S, Takeuchi K, Imoto I, Katai H, Yamaguchi T, Inazawa J, Hirohashi S, Ishikawa Y, Shibata T. Krüppel-like factor 12 plays a significant role in poorly differentiated gastric cancer progression. Int J Cancer 2009; 125:1859-67. [PMID: 19588488 DOI: 10.1002/ijc.24538] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Gastric cancer is the second common malignant neoplasia in Japan, and its poorly differentiated form is a deadly disease. To identify novel candidate oncogenes contributing to its genesis, we examined copy-number alterations in 50 primary poorly differentiated gastric cancers using an array-based comparative genomic hybridization (array-CGH). Many genetic changes were identified, including a novel amplification of the 13q22 locus. Several genes are located in this locus, and selective knockdown of one for the Krüppel-like factor 12 (KLF12) induced significant growth-arrest in the HGC27 gastric cancer cell line. Microarray analysis also demonstrated that genes associated with cell proliferation were mostly changed by KLF12 knockdown. To explore the oncogenic function of KLF12, we introduced a full length of human KLF12 cDNA into NIH3T3 and AZ-521 cell lines and found that overexpression significantly enhanced their invasive potential. In clinical samples, KLF12 mRNA in cancer tissue was increased in 11 of 28 cases (39%) when compared with normal gastric epithelium. Clinicopathological analysis further demonstrated a significant correlation between KLF12mRNA levels and tumor size (p = 0.038). These data suggest that the KLF12 gene plays an important role in poorly differentiated gastric cancer progression and is a potential target of therapeutic measures.
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Affiliation(s)
- Yu Nakamura
- Cancer Genomics Project, National Cancer Center Research Institute, Tokyo 104-0045, Japan
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Sehl ME, Langer LR, Papp JC, Kwan L, Seldon JL, Arellano G, Reiss J, Reed EF, Dandekar S, Korin Y, Sinsheimer JS, Zhang ZF, Ganz PA. Associations between single nucleotide polymorphisms in double-stranded DNA repair pathway genes and familial breast cancer. Clin Cancer Res 2009; 15:2192-203. [PMID: 19276285 PMCID: PMC2778342 DOI: 10.1158/1078-0432.ccr-08-1417] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
PURPOSE DNA damage recognition and repair play a major role in risk for breast cancer. We investigated 104 single nucleotide polymorphisms (SNP) in 17 genes whose protein products are involved in double-stranded break repair (DSBR). EXPERIMENTAL DESIGN We used a case-control design. Both the case individuals affected with breast cancer or with both breast and ovarian cancers and the controls had similar familial risk of breast cancer and were participants in a high-risk cancer registry. RESULTS We found that 12 of the polymorphisms are associated with breast or breast and ovarian cancers, most notably rs16888927, rs16888997, and rs16889040, found in introns of RAD21, suggesting that SNPs in other genes in the DSBR pathway in addition to BRCA1 and BRCA2 may affect breast cancer risk. CONCLUSIONS SNPs within or near several DSBR DNA repair pathway genes are associated with breast cancer in individuals from a high-risk population. In addition, our study reemphasizes the unique perspective that recruitment of cases and controls from family cancer registries has for gene discovery studies.
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Affiliation(s)
- Mary E Sehl
- Divisions of Hematology and Oncology and Geriatrics, Department of Medicine, David Geffen School of Medicine at University of California at Los Angeles, USA.
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Jalava SE, Porkka KP, Rauhala HE, Isotalo J, Tammela TL, Visakorpi T. TCEB1 promotes invasion of prostate cancer cells. Int J Cancer 2009; 124:95-102. [PMID: 18844214 DOI: 10.1002/ijc.23916] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Amplification of the long arm of chromosome 8 is one of the most recurrent findings in prostate cancer and it is associated with poor prognosis. Several minimal regions of amplification suggest multiple target genes which are yet to be identified. We have previously shown that TCEB1, EIF3S3, KIAA0196 and RAD21 are amplified and overexpressed in prostate cancer and they are located in the 8q area. In this study, we examined the functional effects of these genes to prostate cancer cell phenotype. We overexpressed and inhibited the genes by lentivirus mediated overexpression and RNA interference, respectively. shRNA mediated TCEB1 silencing decreased significantly cellular invasion of PC-3 and DU145 cells through Matrigel. TCEB1 silencing reduced the anchorage-independent growth of PC-3 cells. Similar effects were not seen with any other genes. When overexpressed in NIH 3T3 cells, TCEB1 and EIF3S3 increased the growth rate of the cells. Transcriptional profiling of TCEB1 silenced PC-3 cells revealed decrease of genes involved in invasion and metastasis. Finally, we also confirmed here the overexpression of TCEB1 in hormone-refractory prostate tumors. This study indicates that TCEB1 promotes invasion of prostate cancer cells, is involved in development of hormone-refractory prostate cancer and is thereby a strong candidate to be one of the target genes for the 8q gain.
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Affiliation(s)
- Sanni E Jalava
- Laboratory of Cancer Genetics, Institute of Medical Technology, University of Tampere and Tampere University Hospital, Tampere, Finland
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78
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Yang H, Ren Q, Zhang Z. Cleavage of Mcd1 by caspase-like protease Esp1 promotes apoptosis in budding yeast. Mol Biol Cell 2008; 19:2127-34. [PMID: 18321989 PMCID: PMC2366870 DOI: 10.1091/mbc.e07-11-1113] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Revised: 01/29/2008] [Accepted: 02/27/2008] [Indexed: 11/11/2022] Open
Abstract
Over the last decade, yeast has been used successfully as a model system for studying the molecular mechanism of apoptotic cell death. Here, we report that Mcd1, the yeast homology of human cohesin Rad21, plays an important role in hydrogen peroxide-induced apoptosis in yeast. On induction of cell death, Mcd1 is cleaved and the C-terminal fragment is translocated from nucleus into mitochondria, causing the decrease of mitochondrial membrane potential and the amplification of cell death in a cytochrome c-dependent manner. We further demonstrate that the caspase-like protease Esp1 has dual functions and that it is responsible for the cleavage of Mcd1 during the hydrogen peroxide-induced apoptosis. When apoptosis is induced, Esp1 is released from the anaphase inhibitor Pds1. The activated Esp1 acts as caspase-like protease for the cleavage of Mcd1, which enhances the cell death via its translocation from nucleus to mitochondria.
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Affiliation(s)
- Hui Yang
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071
| | - Qun Ren
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071
| | - Zhaojie Zhang
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071
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79
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Pierga JY, Reis-Filho JS, Cleator SJ, Dexter T, MacKay A, Simpson P, Fenwick K, Iravani M, Salter J, Hills M, Jones C, Ashworth A, Smith IE, Powles T, Dowsett M. Microarray-based comparative genomic hybridisation of breast cancer patients receiving neoadjuvant chemotherapy. Br J Cancer 2007; 96:341-51. [PMID: 17133270 PMCID: PMC2359992 DOI: 10.1038/sj.bjc.6603483] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Revised: 10/12/2006] [Accepted: 10/23/2006] [Indexed: 12/29/2022] Open
Abstract
We analysed the molecular genetic profiles of breast cancer samples before and after neoadjuvant chemotherapy with combination doxorubicin and cyclophosphamide (AC). DNA was obtained from microdissected frozen breast core biopsies from 44 patients before chemotherapy. Additional samples were obtained before the second course of chemotherapy (D21) and after the completion of the treatment (surgical specimens) in 17 and 21 patients, respectively. Microarray-based comparative genome hybridisation was performed using a platform containing approximately 5800 bacterial artificial chromosome clones (genome-wide resolution: 0.9 Mb). Analysis of the 44 pretreatment biopsies revealed that losses of 4p, 4q, 5q, 12q13.11-12q13.12, 17p11.2 and 17q11.2; and gains of 1p, 2p, 7q, 9p, 11q, 19p and 19q were significantly associated with oestrogen receptor negativity. 16q21-q22.1 losses were associated with lobular and 8q24 gains with ductal types. Losses of 5q33.3-q4 and 18p11.31 and gains of 6p25.1-p25.2 and Xp11.4 were associated with HER2 amplification. No correlations between DNA copy number changes and clinical response to AC were found. Microarray-based comparative genome hybridisation analysis of matched pretreatment and D21 biopsies failed to identify statistically significant differences, whereas a comparison between matched pretreatment and surgical samples revealed a statistically significant acquired copy number gain on 11p15.2-11p15.5. The modest chemotherapy-driven genomic changes, despite profound loss of cell numbers, suggest that there is little therapeutic selection of resistant non-modal cell lineages.
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Affiliation(s)
- J-Y Pierga
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
- Medical Oncology Department, Institut Curie, Paris, cedex 5, France
| | - J S Reis-Filho
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - S J Cleator
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - T Dexter
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - A MacKay
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - P Simpson
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - K Fenwick
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - M Iravani
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - J Salter
- Academic Department of Biochemistry, Royal Marsden Hospital NHS Trust, Fulham Road, London, SW3 6JJ, UK
| | - M Hills
- Academic Department of Biochemistry, Royal Marsden Hospital NHS Trust, Fulham Road, London, SW3 6JJ, UK
| | - C Jones
- Section of Paediatric Oncology, Institute of Cancer Research, London, SM2 5NG, UK
| | - A Ashworth
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
| | - I E Smith
- Breast Cancer Unit, Royal Marsden Hospital, London, SW3 6JJ, UK
| | - T Powles
- Breast Cancer Unit, Royal Marsden Hospital, London, SW3 6JJ, UK
| | - M Dowsett
- Breakthrough Breast Cancer Research Center, The Institute of Cancer Research, London, SW3 6JB, UK
- Academic Department of Biochemistry, Royal Marsden Hospital NHS Trust, Fulham Road, London, SW3 6JJ, UK
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80
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Abstract
Replicated DNA molecules are physically connected by cohesin complexes from the time of their synthesis in S-phase until they are segregated during anaphase of the subsequent mitosis or meiosis. This sister chromatid cohesion is essential for the biorientation of chromosomes on the mitotic or meiotic spindle. In addition, cohesion is also essential during G2-phase of the cell cycle to allow repair of DNA double-strand breaks by homologous recombination. Although cohesion can normally only be established during S-phase, recent work in yeast has shown that DNA double-strand breaks induce the recruitment of cohesin to the damage site and lead to the de novo formation of cohesion at this site. It is unknown if similar mechanisms operate in higher eukaryotes, but in mammalian cells phosphorylation of the cohesin subunit Smc1 by the protein kinase Atm has been shown to be important for DNA repair. We discuss how cohesin and sister chromatid cohesion might facilitate the repair of damaged DNA.
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Affiliation(s)
- Erwan Watrin
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
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81
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Toyoda Y, Yanagida M. Coordinated requirements of human topo II and cohesin for metaphase centromere alignment under Mad2-dependent spindle checkpoint surveillance. Mol Biol Cell 2006; 17:2287-302. [PMID: 16510521 PMCID: PMC1446084 DOI: 10.1091/mbc.e05-11-1089] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Revised: 02/16/2006] [Accepted: 02/21/2006] [Indexed: 01/27/2023] Open
Abstract
Cohesin maintains sister chromatid cohesion until its Rad21/Scc1/Mcd1 is cleaved by separase during anaphase. DNA topoisomerase II (topo II) maintains the proper topology of chromatid DNAs and is essential for chromosome segregation. Here we report direct observations of mitotic progression in individual HeLa cells after functional disruptions of hRad21, NIPBL, a loading factor for hRad21, and topo II alpha,beta by RNAi and a topo II inhibitor, ICRF-193. Mitosis is delayed in a Mad2-dependent manner after disruption of either or both cohesin and topo II. In hRad21 depletion, interphase pericentric architecture becomes aberrant, and anaphase is virtually permanently delayed as preseparated chromosomes are misaligned on the metaphase spindle. Topo II disruption perturbs centromere organization leading to intense Bub1, but no Mad2, on kinetochores and sustains a Mad2-dependent delay in anaphase onset with persisting securin. Thus topo II impinges upon centromere/kinetochore function. Disruption of topo II by RNAi or ICRF-193 overrides the mitotic delay induced by cohesin depletion: sister centromeres are aligned and anaphase spindle movements occur. The ensuing accumulation of catenations in preseparated sister chromatids may overcome the reduced tension arising from cohesin depletion, causing the override. Cohesin and topo II have distinct, yet coordinated functions in metaphase alignment.
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Affiliation(s)
- Yusuke Toyoda
- Department of Gene Mechanisms, Graduate School of Biostudies, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan
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