51
|
Clemente-Ruiz M, Murillo-Maldonado JM, Benhra N, Barrio L, Pérez L, Quiroga G, Nebreda AR, Milán M. Gene Dosage Imbalance Contributes to Chromosomal Instability-Induced Tumorigenesis. Dev Cell 2016; 36:290-302. [PMID: 26859353 DOI: 10.1016/j.devcel.2016.01.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 11/27/2015] [Accepted: 01/08/2016] [Indexed: 01/15/2023]
Abstract
Chromosomal instability (CIN) is thought to be a source of mutability in cancer. However, CIN often results in aneuploidy, which compromises cell fitness. Here, we used the dosage compensation mechanism (DCM) of Drosophila to demonstrate that chromosome-wide gene dosage imbalance contributes to the deleterious effects of CIN-induced aneuploidy and its pro-tumorigenic action. We present evidence that resetting of the DCM counterbalances the damaging effects caused by CIN-induced changes in X chromosome number. Importantly, interfering with the DCM suffices to mimic the cellular effects of aneuploidy in terms of reactive oxygen species (ROS) production, JNK-dependent cell death, and tumorigenesis upon apoptosis inhibition. We unveil a role of ROS in JNK activation and a variety of cellular and tissue-wide mechanisms that buffer the deleterious effects of CIN, including DNA-damage repair, activation of the p38 pathway, and cytokine induction to promote compensatory proliferation. Our data reveal the existence of robust compensatory mechanisms that counteract CIN-induced cell death and tumorigenesis.
Collapse
Affiliation(s)
- Marta Clemente-Ruiz
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10-12, 08028 Barcelona, Spain
| | - Juan M Murillo-Maldonado
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10-12, 08028 Barcelona, Spain
| | - Najate Benhra
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10-12, 08028 Barcelona, Spain
| | - Lara Barrio
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10-12, 08028 Barcelona, Spain
| | - Lidia Pérez
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10-12, 08028 Barcelona, Spain
| | - Gonzalo Quiroga
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10-12, 08028 Barcelona, Spain
| | - Angel R Nebreda
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluis Companys, 23, 08011 Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10-12, 08028 Barcelona, Spain
| | - Marco Milán
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluis Companys, 23, 08011 Barcelona, Spain; Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10-12, 08028 Barcelona, Spain.
| |
Collapse
|
52
|
Vallot C, Ouimette JF, Rougeulle C. Establishment of X chromosome inactivation and epigenomic features of the inactive X depend on cellular contexts. Bioessays 2016; 38:869-80. [PMID: 27389958 DOI: 10.1002/bies.201600121] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
X chromosome inactivation (XCI) is an essential epigenetic process that ensures X-linked gene dosage equilibrium between sexes in mammals. XCI is dynamically regulated during development in a manner that is intimately linked to differentiation. Numerous studies, which we review here, have explored the dynamics of X inactivation and reactivation in the context of development, differentiation and diseases, and the phenotypic and molecular link between the inactive status, and the cellular context. Here, we also assess whether XCI is a uniform mechanism in mammals by analyzing epigenetic signatures of the inactive X (Xi) in different species and cellular contexts. It appears that the timing of XCI and the epigenetic signature of the inactive X greatly vary between species. Surprisingly, even within a given species, various Xi configurations are found across cellular states. We discuss possible mechanisms underlying these variations, and how they might influence the fate of the Xi.
Collapse
Affiliation(s)
- Céline Vallot
- Sorbonne Paris Cité, Epigenetics and Cell Fate, Université Paris Diderot, Paris, France
| | | | - Claire Rougeulle
- Sorbonne Paris Cité, Epigenetics and Cell Fate, Université Paris Diderot, Paris, France
| |
Collapse
|
53
|
Maeda I, Tajima S, Ariizumi Y, Doi M, Endo A, Naruki S, Hoshikawa M, Koizumi H, Kanemaki Y, Ueno T, Tsugawa K, Takagi M. Can synaptophysin be used as a marker of breast cancer diagnosed by core-needle biopsy in epithelial proliferative diseases of the breast? Pathol Int 2016; 66:369-75. [DOI: 10.1111/pin.12420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 04/03/2016] [Accepted: 04/29/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Ichiro Maeda
- Department of Pathology; St. Marianna University School of Medicine; Kawasaki Japan
| | - Shinya Tajima
- Department of Pathology; St. Marianna University School of Medicine; Kawasaki Japan
| | - Yasushi Ariizumi
- Department of Pathology; St. Marianna University School of Medicine; Kawasaki Japan
| | - Masatomo Doi
- Department of Pathology; St. Marianna University School of Medicine; Kawasaki Japan
| | - Akira Endo
- Department of Pathology; St. Marianna University School of Medicine; Kawasaki Japan
| | - Saeko Naruki
- Department of Pathology; St. Marianna University School of Medicine; Kawasaki Japan
| | - Masahiro Hoshikawa
- Department of Pathology; St. Marianna University School of Medicine; Kawasaki Japan
| | - Hirotaka Koizumi
- Department of Pathology; St. Marianna University School of Medicine; Kawasaki Japan
| | - Yoshihide Kanemaki
- Department of Radiology; St. Marianna University School of Medicine; Kawasaki Japan
| | - Takahiko Ueno
- Unit of Medical Statistics, Faculty of Medical Education and Culture; St. Marianna University School of Medicine; Kawasaki Japan
| | - Koichiro Tsugawa
- Department of Breast and Endocrine Surgery; St. Marianna University School of Medicine; Kawasaki Japan
| | - Masayuki Takagi
- Department of Pathology; St. Marianna University School of Medicine; Kawasaki Japan
| |
Collapse
|
54
|
Schmitt AM, Chang HY. Long Noncoding RNAs in Cancer Pathways. Cancer Cell 2016; 29:452-463. [PMID: 27070700 PMCID: PMC4831138 DOI: 10.1016/j.ccell.2016.03.010] [Citation(s) in RCA: 2311] [Impact Index Per Article: 288.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/01/2016] [Accepted: 03/14/2016] [Indexed: 12/16/2022]
Abstract
Genome-wide cancer mutation analyses are revealing an extensive landscape of functional mutations within the noncoding genome, with profound effects on the expression of long noncoding RNAs (lncRNAs). While the exquisite regulation of lncRNA transcription can provide signals of malignant transformation, we now understand that lncRNAs drive many important cancer phenotypes through their interactions with other cellular macromolecules including DNA, protein, and RNA. Recent advancements in surveying lncRNA molecular mechanisms are now providing the tools to functionally annotate these cancer-associated transcripts, making these molecules attractive targets for therapeutic intervention in the fight against cancer.
Collapse
Affiliation(s)
- Adam M Schmitt
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA 94305, USA.
| |
Collapse
|
55
|
Kang J, Lee HJ, Jun SY, Park ES, Maeng LS. Cancer-Testis Antigen Expression in Serous Endometrial Cancer with Loss of X Chromosome Inactivation. PLoS One 2015; 10:e0137476. [PMID: 26360551 PMCID: PMC4567132 DOI: 10.1371/journal.pone.0137476] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 08/17/2015] [Indexed: 01/28/2023] Open
Abstract
Background Cancer-testis antigens (CTAs) are potential targets for cancer immunotherapy. Many CTAs are located on the X chromosome and are epigenetically regulated. Loss of X chromosome inactivation (XCI) is observed in breast and ovarian cancers and is thought to be related to the overexpression of CTAs. We investigated the relation between expression of CTAs and loss of XCI in endometrial cancer. Materials and Methods We used data generated by The Cancer Genome Atlas Genome Data Analysis Centers and data for Xist knockout mice available at the Gene Expression Omnibus. Results The status of XCI was estimated by methylation status, and deletion or gain of the X chromosome. The endometrial cancers were classified into the following three groups: preserved inactivated X chromosome (Xi) (n = 281), partial reactivation of Xi (n = 52), and two copies of active X group (n = 38). Loss of XCI was more common in serous adenocarcinoma. Expression of CTAs increased in endometrial cancer with loss of XCI, which was accompanied by global hypomethylation. Expression of CTAs did not increase in Xist knockout mice. Conclusions Loss of XCI is common in serous adenocarcinoma. Global hypomethylation, and not loss of XCI, is the main mechanism of overexpression of CTAs.
Collapse
Affiliation(s)
- Jun Kang
- Department of Hospital Pathology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Inchun, Republic of Korea
- * E-mail:
| | - Hee Jin Lee
- Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
| | - Sun-Young Jun
- Department of Hospital Pathology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Inchun, Republic of Korea
| | - Eun Su Park
- Department of Hospital Pathology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Inchun, Republic of Korea
| | - Lee-so Maeng
- Department of Hospital Pathology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Inchun, Republic of Korea
| |
Collapse
|
56
|
Biesma HD, Schouten PC, Lacle MM, Sanders J, Brugman W, Kerkhoven R, Mandjes I, van der Groep P, van Diest PJ, Linn SC. Copy number profiling by array comparative genomic hybridization identifies frequently occurring BRCA2-like male breast cancer. Genes Chromosomes Cancer 2015; 54:734-44. [DOI: 10.1002/gcc.22284] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 06/25/2015] [Indexed: 11/08/2022] Open
Affiliation(s)
- Hedde D. Biesma
- Department of Molecular Pathology; Netherlands Cancer Institute; Amsterdam The Netherlands
| | - Philip C. Schouten
- Department of Molecular Pathology; Netherlands Cancer Institute; Amsterdam The Netherlands
| | - Miangela M. Lacle
- Department of Pathology; University Medical Center Utrecht; The Netherlands
| | - Joyce Sanders
- Department of Pathology; Netherlands Cancer Institute; Amsterdam The Netherlands
| | - Wim Brugman
- Genomics Core Facility, Netherlands Cancer Institute; Amsterdam The Netherlands
| | - Ron Kerkhoven
- Genomics Core Facility, Netherlands Cancer Institute; Amsterdam The Netherlands
| | - Ingrid Mandjes
- Data Center, Netherlands Cancer Institute; Amsterdam The Netherlands
| | | | - Paul J. van Diest
- Department of Pathology; University Medical Center Utrecht; The Netherlands
| | - Sabine C. Linn
- Department of Molecular Pathology; Netherlands Cancer Institute; Amsterdam The Netherlands
- Department of Pathology; University Medical Center Utrecht; The Netherlands
- Department of Medical Oncology; Netherlands Cancer Institute; Amsterdam The Netherlands
| |
Collapse
|
57
|
Abstract
Dynamic gene expression during cellular differentiation is tightly coordinated by transcriptional and post-transcriptional mechanisms. An emerging theme is the central role of long noncoding RNAs (lncRNAs) in the regulation of this specificity. Recent advances demonstrate that lncRNAs are expressed in a lineage-specific manner and control the development of several cell types in the hematopoietic system. Moreover, specific lncRNAs are induced to modulate innate and adaptive immune responses. lncRNAs can function via RNA-DNA, RNA-RNA, and RNA-protein target interactions. As a result, they affect several stages of gene regulation, including chromatin modification, mRNA biogenesis, and protein signaling. We discuss recent advances, future prospects, and challenges in understanding the roles of lncRNAs in immunity and immune-mediated diseases.
Collapse
Affiliation(s)
- Ansuman T Satpathy
- Howard Hughes Medical Institute and Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Howard Y Chang
- Howard Hughes Medical Institute and Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| |
Collapse
|
58
|
Swanson EC, Rapkin LM, Bazett-Jones DP, Lawrence JB. Unfolding the story of chromatin organization in senescent cells. Nucleus 2015; 6:254-60. [PMID: 26107557 DOI: 10.1080/19491034.2015.1057670] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Cell senescence, the permanent withdrawal of a cell from the cell cycle, is characterized by dramatic, cytological scale changes to DNA condensation throughout the genome. While prior emphasis has been placed on increases in heterochromatin, such as the formation of compact Senescent Associated Heterochromatin Foci (SAHF) structures, our recent findings showed that SAHF formation is preceded by the unravelling of constitutive heterochromatin into visibly extended structures, which we have termed Senescent Associated Distension of Satellites or SADS. Interestingly, neither of these marked changes in DNA condensation appear to be mediated by changes in canonical, heterochromatin-associated histone modifications. Rather, several observations suggest that these events may be facilitated by changes in LaminB1 levels and/or other factors that control higher-order chromatin architecture. Here, we review what is known about senescence-associated chromatin reorganization and present preliminary results using high-resolution microscopy techniques to show that each peri/centromeric satellite in senescent cells is comprised of several condensed domains connected by thin fibrils of satellite DNA. We then discuss the potential importance of these striking changes in chromatin condensation for cell senescence, and also as a model to provide a needed window into the higher-order packaging of the genome.
Collapse
Affiliation(s)
- Eric C Swanson
- a Department of Cell and Developmental Biology ; University of Massachusetts Medical School ; Worcester , MA USA
| | | | | | | |
Collapse
|
59
|
Fatima R, Akhade VS, Pal D, Rao SMR. Long noncoding RNAs in development and cancer: potential biomarkers and therapeutic targets. MOLECULAR AND CELLULAR THERAPIES 2015; 3:5. [PMID: 26082843 PMCID: PMC4469312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 05/19/2015] [Indexed: 11/21/2023]
Abstract
Long noncoding RNAs are emerging as key players in various fundamental biological processes. We highlight the varied molecular mechanisms by which lncRNAs modulate gene expression in diverse cellular contexts and their role in early mammalian development in this review. Furthermore, it is being increasingly recognized that altered expression of lncRNAs is specifically associated with tumorigenesis, tumor progression and metastasis. We discuss various lncRNAs implicated in different cancer types with a focus on their clinical applications as potential biomarkers and therapeutic targets in the pathology of diverse cancers.
Collapse
Affiliation(s)
- Roshan Fatima
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur, Bangalore 560064 India
| | - Vijay Suresh Akhade
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur, Bangalore 560064 India
| | - Debosree Pal
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur, Bangalore 560064 India
| | - Satyanarayana MR Rao
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur, Bangalore 560064 India
| |
Collapse
|
60
|
Fatima R, Akhade VS, Pal D, Rao SM. Long noncoding RNAs in development and cancer: potential biomarkers and therapeutic targets. MOLECULAR AND CELLULAR THERAPIES 2015; 3:5. [PMID: 26082843 PMCID: PMC4469312 DOI: 10.1186/s40591-015-0042-6] [Citation(s) in RCA: 203] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 05/19/2015] [Indexed: 02/07/2023]
Abstract
Long noncoding RNAs are emerging as key players in various fundamental biological processes. We highlight the varied molecular mechanisms by which lncRNAs modulate gene expression in diverse cellular contexts and their role in early mammalian development in this review. Furthermore, it is being increasingly recognized that altered expression of lncRNAs is specifically associated with tumorigenesis, tumor progression and metastasis. We discuss various lncRNAs implicated in different cancer types with a focus on their clinical applications as potential biomarkers and therapeutic targets in the pathology of diverse cancers.
Collapse
Affiliation(s)
- Roshan Fatima
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur, Bangalore 560064 India
| | - Vijay Suresh Akhade
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur, Bangalore 560064 India
| | - Debosree Pal
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur, Bangalore 560064 India
| | - Satyanarayana Mr Rao
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur, Bangalore 560064 India
| |
Collapse
|
61
|
Kang J, Lee HJ, Kim J, Lee JJ, Maeng LS. Dysregulation of X chromosome inactivation in high grade ovarian serous adenocarcinoma. PLoS One 2015; 10:e0118927. [PMID: 25742136 PMCID: PMC4351149 DOI: 10.1371/journal.pone.0118927] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 01/07/2015] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND One of the two copies of the X chromosome is randomly inactivated in females as a means of dosage compensation. Loss of X chromosome inactivation (XCI) is observed in breast and ovarian cancers, and is frequent in basal-like subtype and BRCA1 mutation-associated breast cancers. We investigated the clinical implications of the loss of XCI in ovarian cancer and the association between the loss of XCI and BRCA1 dysfunction. MATERIALS AND METHODS We used open source data generated by The Cancer Genome Atlas (TCGA) Genome Data Analysis Centers. Ward's hierarchical clustering method was used to classify the methylation status of the X chromosome. RESULTS We grouped 584 high grade serous ovarian adenocarcinomas (HG-SOA) according to methylation status, loss of heterozygosity and deletion or gain of X chromosome into the following five groups: preserved inactivated X chromosome (Xi) group (n = 175), partial reactivation of Xi group (n = 100), p arm deletion of Xi group (n = 35), q arm deletion of Xi group (n = 44), and two copies of active X group (n = 230). We found four genes (XAGE3, ZNF711, MAGEA4, and ZDHHC15) that were up-regulated by loss of XCI. HG-SOA with loss of XCI showed aggressive behavior (overall survival of partial reactivation of Xi group: HR 1.7, 95% CI 1.1-2.5, two copies of active X group: HR 1.4, 95% CI 1.0-1.9). Mutation and hypermethylation of BRCA1 were not frequent in HG-SOA with loss of XCI. CONCLUSIONS Loss of XCI is common in HG-SOA and is associated with poor clinical outcome. The role of BRCA1 in loss of XCI might be limited. XCI induced aberrant expression of cancer-testis antigens, which may have a role in tumor aggressiveness.
Collapse
Affiliation(s)
- Jun Kang
- Department of Hospital Pathology, Inchun St. Mary’s hospital, College of Medicine, The Catholic University of Korea, Inchun, Republic of Korea
- * E-mail:
| | - Hee Jin Lee
- Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
| | - Jiyoung Kim
- Department of Hospital Pathology, Inchun St. Mary’s hospital, College of Medicine, The Catholic University of Korea, Inchun, Republic of Korea
| | - Jae Jun Lee
- Department of Hospital Pathology, Inchun St. Mary’s hospital, College of Medicine, The Catholic University of Korea, Inchun, Republic of Korea
| | - Lee-so Maeng
- Department of Hospital Pathology, Inchun St. Mary’s hospital, College of Medicine, The Catholic University of Korea, Inchun, Republic of Korea
| |
Collapse
|
62
|
Chaligné R, Popova T, Mendoza-Parra MA, Saleem MAM, Gentien D, Ban K, Piolot T, Leroy O, Mariani O, Gronemeyer H, Vincent-Salomon A, Stern MH, Heard E. The inactive X chromosome is epigenetically unstable and transcriptionally labile in breast cancer. Genome Res 2015; 25:488-503. [PMID: 25653311 PMCID: PMC4381521 DOI: 10.1101/gr.185926.114] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 01/28/2015] [Indexed: 12/19/2022]
Abstract
Disappearance of the Barr body is considered a hallmark of cancer, although whether this corresponds to genetic loss or to epigenetic instability and transcriptional reactivation is unclear. Here we show that breast tumors and cell lines frequently display major epigenetic instability of the inactive X chromosome, with highly abnormal 3D nuclear organization and global perturbations of heterochromatin, including gain of euchromatic marks and aberrant distributions of repressive marks such as H3K27me3 and promoter DNA methylation. Genome-wide profiling of chromatin and transcription reveal modified epigenomic landscapes in cancer cells and a significant degree of aberrant gene activity from the inactive X chromosome, including several genes involved in cancer promotion. We demonstrate that many of these genes are aberrantly reactivated in primary breast tumors, and we further demonstrate that epigenetic instability of the inactive X can lead to perturbed dosage of X-linked factors. Taken together, our study provides the first integrated analysis of the inactive X chromosome in the context of breast cancer and establishes that epigenetic erosion of the inactive X can lead to the disappearance of the Barr body in breast cancer cells. This work offers new insights and opens up the possibility of exploiting the inactive X chromosome as an epigenetic biomarker at the molecular and cytological levels in cancer.
Collapse
Affiliation(s)
- Ronan Chaligné
- Centre de Recherche, Institut Curie, 75248 Paris Cedex 05, France; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3215, Institut Curie, 75248 Paris Cedex 05, France; Institut National de la Santé et de la Recherche Médicale U934, Institut Curie, 75248 Paris Cedex 05, France; Equipe Labellisée Ligue Contre le Cancer, UMR3215, 75248 Paris Cedex 05, France
| | - Tatiana Popova
- Centre de Recherche, Institut Curie, 75248 Paris Cedex 05, France; Institut National de la Santé et de la Recherche Médicale U830, Institut Curie, 75248 Paris Cedex 05, France
| | - Marco-Antonio Mendoza-Parra
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Equipe Labellisée Ligue Contre le Cancer, Centre National de la Recherche Scientifique UMR 7104, Institut National de la Santé et de la Recherche Médicale U964, University of Strasbourg, 67404 Illkirch Cedex, France
| | - Mohamed-Ashick M Saleem
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Equipe Labellisée Ligue Contre le Cancer, Centre National de la Recherche Scientifique UMR 7104, Institut National de la Santé et de la Recherche Médicale U964, University of Strasbourg, 67404 Illkirch Cedex, France
| | - David Gentien
- Centre de Recherche, Institut Curie, 75248 Paris Cedex 05, France; Department of Tumor Biology, Institut Curie, 75248 Paris Cedex 05, France
| | - Kristen Ban
- Centre de Recherche, Institut Curie, 75248 Paris Cedex 05, France; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3215, Institut Curie, 75248 Paris Cedex 05, France; Institut National de la Santé et de la Recherche Médicale U934, Institut Curie, 75248 Paris Cedex 05, France; Equipe Labellisée Ligue Contre le Cancer, UMR3215, 75248 Paris Cedex 05, France
| | - Tristan Piolot
- Centre de Recherche, Institut Curie, 75248 Paris Cedex 05, France; Plate-forme d'Imagerie Cellulaire et Tissulaire at BDD (Pict@BDD), Institut Curie, 75248 Paris Cedex 05, France
| | - Olivier Leroy
- Centre de Recherche, Institut Curie, 75248 Paris Cedex 05, France; Plate-forme d'Imagerie Cellulaire et Tissulaire at BDD (Pict@BDD), Institut Curie, 75248 Paris Cedex 05, France
| | - Odette Mariani
- Department of Tumor Biology, Institut Curie, 75248 Paris Cedex 05, France
| | - Hinrich Gronemeyer
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Equipe Labellisée Ligue Contre le Cancer, Centre National de la Recherche Scientifique UMR 7104, Institut National de la Santé et de la Recherche Médicale U964, University of Strasbourg, 67404 Illkirch Cedex, France;
| | - Anne Vincent-Salomon
- Centre de Recherche, Institut Curie, 75248 Paris Cedex 05, France; Equipe Labellisée Ligue Contre le Cancer, UMR3215, 75248 Paris Cedex 05, France; Institut National de la Santé et de la Recherche Médicale U830, Institut Curie, 75248 Paris Cedex 05, France; Department of Tumor Biology, Institut Curie, 75248 Paris Cedex 05, France;
| | - Marc-Henri Stern
- Centre de Recherche, Institut Curie, 75248 Paris Cedex 05, France; Institut National de la Santé et de la Recherche Médicale U830, Institut Curie, 75248 Paris Cedex 05, France; Department of Tumor Biology, Institut Curie, 75248 Paris Cedex 05, France;
| | - Edith Heard
- Centre de Recherche, Institut Curie, 75248 Paris Cedex 05, France; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3215, Institut Curie, 75248 Paris Cedex 05, France; Institut National de la Santé et de la Recherche Médicale U934, Institut Curie, 75248 Paris Cedex 05, France; Equipe Labellisée Ligue Contre le Cancer, UMR3215, 75248 Paris Cedex 05, France;
| |
Collapse
|
63
|
Richard JLC, Ogawa Y. Understanding the Complex Circuitry of lncRNAs at the X-inactivation Center and Its Implications in Disease Conditions. Curr Top Microbiol Immunol 2015; 394:1-27. [PMID: 25982976 DOI: 10.1007/82_2015_443] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Balanced gene expression is a high priority in order to maintain optimal functioning since alterations and variations could result in acute consequences. X chromosome inactivation (X-inactivation) is one such strategy utilized by mammalian species to silence the extra X chromosome in females to uphold a similar level of expression between the two sexes. A functionally versatile class of molecules called long noncoding RNA (lncRNA) has emerged as key regulators of gene expression and plays important roles during development. An lncRNA that is indispensable for X-inactivation is X-inactive specific transcript (Xist), which induces a repressive epigenetic landscape and creates the inactive X chromosome (Xi). With recent advents in the field of X-inactivation, novel positive and negative lncRNA regulators of Xist such as Jpx and Tsix, respectively, have broadened the regulatory network of X-inactivation. Xist expression failure or dysregulation has been implicated in producing developmental anomalies and disease states. Subsequently, reactivation of the Xi at a later stage of development has also been associated with certain tumors. With the recent influx of information about lncRNA biology and advancements in methods to probe lncRNA, we can now attempt to understand this complex network of Xist regulation in development and disease. It has become clear that the presence of an extra set of genes could be fatal for the organism. Only by understanding the precise ways in which lncRNAs function can treatments be developed to bring aberrations under control. This chapter summarizes our current understanding and knowledge with regard to how lncRNAs are orchestrated at the X-inactivation center (Xic), with a special focus on how genetic diseases come about as a consequence of lncRNA dysregulation.
Collapse
Affiliation(s)
- John Lalith Charles Richard
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center; Department of Pediatrics, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA
| | - Yuya Ogawa
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center; Department of Pediatrics, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA.
| |
Collapse
|
64
|
Chen LL, Zhao JC. Functional analysis of long noncoding RNAs in development and disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 825:129-58. [PMID: 25201105 DOI: 10.1007/978-1-4939-1221-6_4] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Once viewed as part of the "dark matter" of genome, long noncoding RNAs (lncRNAs), which are mRNA-like but lack open reading frames, have emerged as an integral part of the mammalian transcriptome. Recent work demonstrated that lncRNAs play multiple structural and functional roles, and their analysis has become a new frontier in biomedical research. In this chapter, we provide an overview of different lncRNA families, describe methodologies available to study lncRNA-protein and lncRNA-DNA interactions systematically, and use well-studied lncRNAs as examples to illustrate their functional importance during normal development and in disease states.
Collapse
Affiliation(s)
- Ling-Ling Chen
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China,
| | | |
Collapse
|
65
|
Zhang B, Xing X, Li J, Lowdon RF, Zhou Y, Lin N, Zhang B, Sundaram V, Chiappinelli KB, Hagemann IS, Mutch DG, Goodfellow PJ, Wang T. Comparative DNA methylome analysis of endometrial carcinoma reveals complex and distinct deregulation of cancer promoters and enhancers. BMC Genomics 2014; 15:868. [PMID: 25286960 PMCID: PMC4198682 DOI: 10.1186/1471-2164-15-868] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 09/24/2014] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Aberrant DNA methylation is a hallmark of many cancers. Classically there are two types of endometrial cancer, endometrioid adenocarcinoma (EAC), or Type I, and uterine papillary serous carcinoma (UPSC), or Type II. However, the whole genome DNA methylation changes in these two classical types of endometrial cancer is still unknown. RESULTS Here we described complete genome-wide DNA methylome maps of EAC, UPSC, and normal endometrium by applying a combined strategy of methylated DNA immunoprecipitation sequencing (MeDIP-seq) and methylation-sensitive restriction enzyme digestion sequencing (MRE-seq). We discovered distinct genome-wide DNA methylation patterns in EAC and UPSC: 27,009 and 15,676 recurrent differentially methylated regions (DMRs) were identified respectively, compared with normal endometrium. Over 80% of DMRs were in intergenic and intronic regions. The majority of these DMRs were not interrogated on the commonly used Infinium 450K array platform. Large-scale demethylation of chromosome X was detected in UPSC, accompanied by decreased XIST expression. Importantly, we discovered that the majority of the DMRs harbored promoter or enhancer functions and are specifically associated with genes related to uterine development and disease. Among these, abnormal methylation of transposable elements (TEs) may provide a novel mechanism to deregulate normal endometrium-specific enhancers derived from specific TEs. CONCLUSIONS DNA methylation changes are an important signature of endometrial cancer and regulate gene expression by affecting not only proximal promoters but also distal enhancers.
Collapse
MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Aldehyde Dehydrogenase 1 Family
- Carcinoma, Papillary/genetics
- Carcinoma, Papillary/metabolism
- Chromosomes, Human, X
- CpG Islands
- DNA (Cytosine-5-)-Methyltransferases/genetics
- DNA (Cytosine-5-)-Methyltransferases/metabolism
- DNA Methylation
- DNA Transposable Elements/genetics
- Endometrial Neoplasms/genetics
- Endometrial Neoplasms/physiopathology
- Enhancer Elements, Genetic/genetics
- Female
- Humans
- Kruppel-Like Factor 4
- Kruppel-Like Transcription Factors/genetics
- MutL Protein Homolog 1
- Nuclear Proteins/genetics
- Polymorphism, Single Nucleotide
- Promoter Regions, Genetic/genetics
- RNA, Long Noncoding/genetics
- Retinal Dehydrogenase/genetics
- Sequence Analysis, DNA
- Uterine Neoplasms/genetics
- Uterine Neoplasms/physiopathology
Collapse
Affiliation(s)
- Bo Zhang
- />Department of Genetics, Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63108 USA
| | - XiaoYun Xing
- />Department of Genetics, Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63108 USA
| | - Jing Li
- />Department of Genetics, Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63108 USA
- />Shanghai International Joint Cancer Institute, The Second Military Medical University, Shanghai, 200433 P. R. China
| | - Rebecca F Lowdon
- />Department of Genetics, Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63108 USA
| | - Yan Zhou
- />Key Laboratory for Applied Statistics of MOE, School of Mathematics and Statistics, Northeast Normal University, Changchun, Jilin Province 130024 P. R. China
| | - Nan Lin
- />Department of Mathematics and Division of Biostatistics, Washington University in Saint Louis, Saint Louis, MO 63130 USA
| | - Baoxue Zhang
- />Key Laboratory for Applied Statistics of MOE, School of Mathematics and Statistics, Northeast Normal University, Changchun, Jilin Province 130024 P. R. China
| | - Vasavi Sundaram
- />Department of Genetics, Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63108 USA
| | - Katherine B Chiappinelli
- />Department of Oncology, Sidney Kimmel Cancer Center, Johns Hopkins University, Baltimore, MD 21231 USA
| | - Ian S Hagemann
- />Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110 USA
| | - David G Mutch
- />Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Washington University School of Medicine, St Louis, MO 63124 USA
| | - Paul J Goodfellow
- />The Ohio State University Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210 USA
| | - Ting Wang
- />Department of Genetics, Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO 63108 USA
| |
Collapse
|
66
|
Briggs SF, Reijo Pera RA. X chromosome inactivation: recent advances and a look forward. Curr Opin Genet Dev 2014; 28:78-82. [PMID: 25461454 PMCID: PMC4339055 DOI: 10.1016/j.gde.2014.09.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 08/28/2014] [Accepted: 09/16/2014] [Indexed: 12/21/2022]
Abstract
X chromosome inactivation, the transcriptional inactivation of one X chromosome in somatic cells of female mammals, has revealed important advances in our understanding of development, epigenetic control, and RNA biology. Most of this knowledge comes from extensive studies in the mouse; however, there are some significant differences when compared to human biology. This is especially true in pluripotent cell types and, over the past few years, a significant amount of work has been dedicated to understanding these differences. This review focuses specifically on recent advances in the mechanism of Xist spreading, the role of Xist in cancer, the effects of reprogramming on X chromosome inactivation in human induced pluripotent stem cells, and new tools for studying X chromosome inactivation.
Collapse
Affiliation(s)
- Sharon F Briggs
- Department of Genetics, Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, CA, USA
| | - Renee A Reijo Pera
- Department of Cell Biology and Neurosciences, Montana State University, 207 Montana Hall, Bozeman, MT 59711-2460, USA; Department of Chemistry and Biochemistry, Montana State University, 207 Montana Hall, Bozeman, MT 59711-2460, USA.
| |
Collapse
|
67
|
Kononenko AV, Bansal R, Lee NCO, Grimes BR, Masumoto H, Earnshaw WC, Larionov V, Kouprina N. A portable BRCA1-HAC (human artificial chromosome) module for analysis of BRCA1 tumor suppressor function. Nucleic Acids Res 2014; 42:gku870. [PMID: 25260588 PMCID: PMC4245969 DOI: 10.1093/nar/gku870] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BRCA1 is involved in many disparate cellular functions, including DNA damage repair, cell-cycle checkpoint activation, gene transcriptional regulation, DNA replication, centrosome function and others. The majority of evidence strongly favors the maintenance of genomic integrity as a principal tumor suppressor activity of BRCA1. At the same time some functional aspects of BRCA1 are not fully understood. Here, a HAC (human artificial chromosome) module with a regulated centromere was constructed for delivery and expression of the 90 kb genomic copy of the BRCA1 gene into BRCA1-deficient human cells. A battery of functional tests was carried out to demonstrate functionality of the exogenous BRCA1. In separate experiments, we investigated the role of BRCA1 in maintenance of heterochromatin integrity within a human functional kinetochore. We demonstrated that BRCA1 deficiency results in a specific activation of transcription of higher-order alpha-satellite repeats (HORs) assembled into heterochromatin domains flanking the kinetochore. At the same time no detectable elevation of transcription was observed within HORs assembled into centrochromatin domains. Thus, we demonstrated a link between BRCA1 deficiency and kinetochore dysfunction and extended previous observations that BRCA1 is required to silence transcription in heterochromatin in specific genomic loci. This supports the hypothesis that epigenetic alterations of the kinetochore initiated in the absence of BRCA1 may contribute to cellular transformation.
Collapse
Affiliation(s)
- Artem V Kononenko
- Developmental Therapeutics Branch, National Cancer Institute, Bethesda, MD 20892, USA
| | - Ruchi Bansal
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, IN 46202, USA
| | - Nicholas C O Lee
- Developmental Therapeutics Branch, National Cancer Institute, Bethesda, MD 20892, USA
| | - Brenda R Grimes
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, IN 46202, USA
| | - Hiroshi Masumoto
- Laboratory of Cell Engineering, Department of Frontier Research, Kazusa DNA, Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, Scotland
| | - Vladimir Larionov
- Developmental Therapeutics Branch, National Cancer Institute, Bethesda, MD 20892, USA
| | - Natalay Kouprina
- Developmental Therapeutics Branch, National Cancer Institute, Bethesda, MD 20892, USA
| |
Collapse
|
68
|
Chaligné R, Heard E. X-chromosome inactivation in development and cancer. FEBS Lett 2014; 588:2514-22. [PMID: 24937141 DOI: 10.1016/j.febslet.2014.06.023] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 06/06/2014] [Indexed: 12/21/2022]
Abstract
X-chromosome inactivation represents an epigenetics paradigm and a powerful model system of facultative heterochromatin formation triggered by a non-coding RNA, Xist, during development. Once established, the inactive state of the Xi is highly stable in somatic cells, thanks to a combination of chromatin associated proteins, DNA methylation and nuclear organization. However, sporadic reactivation of X-linked genes has been reported during ageing and in transformed cells and disappearance of the Barr body is frequently observed in cancer cells. In this review we summarise current knowledge on the epigenetic changes that accompany X inactivation and discuss the extent to which the inactive X chromosome may be epigenetically or genetically perturbed in breast cancer.
Collapse
Affiliation(s)
- Ronan Chaligné
- Mammalian Developmental Epigenetics Group, Genetics and Developmental Biology Unit, Institut Curie, CNRS UMR3215, INSERM U934, 75248 Paris, France
| | - Edith Heard
- Mammalian Developmental Epigenetics Group, Genetics and Developmental Biology Unit, Institut Curie, CNRS UMR3215, INSERM U934, 75248 Paris, France.
| |
Collapse
|
69
|
Cunha LL, Ferreira RDC, de Matos PS, da Assumpção LVM, Ward LS. Both gender and concurrent chronic lymphocytic thyroiditis may influence the nuclear texture of papillary thyroid carcinomas cells. Endocr Res 2014; 39:126-9. [PMID: 24460065 DOI: 10.3109/07435800.2013.864302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A disparity in gender incidence has been reported in both papillary thyroid carcinoma (PTC) and chronic lymphocytic thyroiditis (CLT) diseases frequently associated and whose incidence has been increasing in parallel. We aimed to analyze differences in morphometric variables between male and female PTC patients and their relationship with the presence of concurrent CLT. The nuclear texture features of 100 hematoxylin-eosin stained nuclei from 100 consecutive classic PTC patients enrolled in our service were compared with their clinical and pathological features, including the presence of CLT. All patients were submitted to a standard management protocol and followed-up for 13-248 months (Mo = 117 months). Chromatin in women tended to present a denser and more homogeneous structure, in a less mottled pattern, with higher values of energy (p = 0.008) and diagonal moment (p = 0.032) than men. Concurrent CLT was more prevalent in women (41.42%) than in men (13.33%, p = 0.04) and was associated with higher cluster prominence values (p = 0.027), a parameter that indicates a predominance of high nuclear contrasted heterochromatin. A multivariate logistic regression analysis showed that higher cluster prominence was independently correlated with chromatin in patients who presented CLT but did not demonstrate any association between concurrent CLT and gender. We were unable to demonstrate any association between gender and any characteristic of tumor aggressiveness or patients outcome. Our results suggest that chromatin texture of hematoxylin-eosin stained nuclei in paraffin sections of PTC cells is related to both gender and concurrent CLT.
Collapse
|
70
|
Long noncoding RNAs: fresh perspectives into the RNA world. Trends Biochem Sci 2013; 39:35-43. [PMID: 24290031 DOI: 10.1016/j.tibs.2013.10.002] [Citation(s) in RCA: 277] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 10/23/2013] [Accepted: 10/24/2013] [Indexed: 12/15/2022]
Abstract
Large-scale mapping of transcriptomes has revealed significant levels of transcriptional activity within both unannotated and annotated regions of the genome. Interestingly, many of the novel transcripts demonstrate tissue-specific expression and some level of sequence conservation across species, but most have low protein-coding potential. Here, we describe progress in identifying and characterizing long noncoding RNAs (lncRNAs) and review how these transcripts interact with other biological molecules to regulate diverse cellular processes. We also preview emerging techniques that will help advance the discovery and characterization of novel transcripts. Finally, we discuss the role of lncRNAs in disease and therapeutics.
Collapse
|
71
|
Han BW, Chen YQ. Potential pathological and functional links between long noncoding RNAs and hematopoiesis. Sci Signal 2013; 6:re5. [PMID: 23962981 DOI: 10.1126/scisignal.2004099] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Differential abundance and activity of long noncoding RNAs (lncRNAs) are recognized as the hallmark features in various diseases. We highlight the lncRNAs that play a functional role in the development of blood cells. Many lncRNAs and the protein complexes within which they interact have been implicated in various types of cancers. Multiple lncRNAs participate in normal and may be implicated in malignant hematopoiesis associated with blood cell cancers, such as leukemia, by regulating gene expression through such mechanisms as redirecting chromatin remodeling complexes and activating epigenetic silencing, either of which can inactivate tumor suppressor genes or activate oncogenes. Because of their potential importance in cancers of the blood, lncRNAs may be useful as diagnostic and prognostic markers, and it may be possible to develop lncRNA-mediated therapy.
Collapse
Affiliation(s)
- Bo-Wei Han
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Science, Sun Yat-sen University, Guangzhou 510275, P. R. China
| | | |
Collapse
|
72
|
Lee JT, Bartolomei MS. X-inactivation, imprinting, and long noncoding RNAs in health and disease. Cell 2013; 152:1308-23. [PMID: 23498939 DOI: 10.1016/j.cell.2013.02.016] [Citation(s) in RCA: 503] [Impact Index Per Article: 45.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Indexed: 12/22/2022]
Abstract
X chromosome inactivation and genomic imprinting are classic epigenetic processes that cause disease when not appropriately regulated in mammals. Whereas X chromosome inactivation evolved to solve the problem of gene dosage, the purpose of genomic imprinting remains controversial. Nevertheless, the two phenomena are united by allelic control of large gene clusters, such that only one copy of a gene is expressed in every cell. Allelic regulation poses significant challenges because it requires coordinated long-range control in cis and stable propagation over time. Long noncoding RNAs have emerged as a common theme, and their contributions to diseases of imprinting and the X chromosome have become apparent. Here, we review recent advances in basic biology, the connections to disease, and preview potential therapeutic strategies for future development.
Collapse
Affiliation(s)
- Jeannie T Lee
- Howard Hughes Medical Institute, Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA.
| | | |
Collapse
|
73
|
Yildirim E, Kirby JE, Brown DE, Mercier FE, Sadreyev RI, Scadden DT, Lee JT. Xist RNA is a potent suppressor of hematologic cancer in mice. Cell 2013; 152:727-42. [PMID: 23415223 PMCID: PMC3875356 DOI: 10.1016/j.cell.2013.01.034] [Citation(s) in RCA: 373] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 12/04/2012] [Accepted: 01/23/2013] [Indexed: 02/06/2023]
Abstract
X chromosome aneuploidies have long been associated with human cancers, but causality has not been established. In mammals, X chromosome inactivation (XCI) is triggered by Xist RNA to equalize gene expression between the sexes. Here we delete Xist in the blood compartment of mice and demonstrate that mutant females develop a highly aggressive myeloproliferative neoplasm and myelodysplastic syndrome (mixed MPN/MDS) with 100% penetrance. Significant disease components include primary myelofibrosis, leukemia, histiocytic sarcoma, and vasculitis. Xist-deficient hematopoietic stem cells (HSCs) show aberrant maturation and age-dependent loss. Reconstitution experiments indicate that MPN/MDS and myelofibrosis are of hematopoietic rather than stromal origin. We propose that Xist loss results in X reactivation and consequent genome-wide changes that lead to cancer, thereby causally linking the X chromosome to cancer in mice. Thus, Xist RNA not only is required to maintain XCI but also suppresses cancer in vivo.
Collapse
Affiliation(s)
- Eda Yildirim
- Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA
| | | | | | | | | | | | | |
Collapse
|
74
|
Anguera MC, Sadreyev R, Zhang Z, Szanto A, Payer B, Sheridan SD, Kwok S, Haggarty SJ, Sur M, Alvarez J, Gimelbrant A, Mitalipova M, Kirby JE, Lee JT. Molecular signatures of human induced pluripotent stem cells highlight sex differences and cancer genes. Cell Stem Cell 2012; 11:75-90. [PMID: 22770242 PMCID: PMC3587778 DOI: 10.1016/j.stem.2012.03.008] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Revised: 12/10/2011] [Accepted: 03/08/2012] [Indexed: 11/25/2022]
Abstract
Although human induced pluripotent stem cells (hiPSCs) have enormous potential in regenerative medicine, their epigenetic variability suggests that some lines may not be suitable for human therapy. There are currently few benchmarks for assessing quality. Here we show that X-inactivation markers can be used to separate hiPSC lines into distinct epigenetic classes and that the classes are phenotypically distinct. Loss of XIST expression is strongly correlated with upregulation of X-linked oncogenes, accelerated growth rate in vitro, and poorer differentiation in vivo. Whereas differences in X-inactivation potential result in epigenetic variability of female hiPSC lines, male hiPSC lines generally resemble each other and do not overexpress the oncogenes. Neither physiological oxygen levels nor HDAC inhibitors offer advantages to culturing female hiPSC lines. We conclude that female hiPSCs may be epigenetically less stable in culture and caution that loss of XIST may result in qualitatively less desirable stem cell lines.
Collapse
Affiliation(s)
- Montserrat C. Anguera
- Howard Hughes Medical Institute, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Genetics, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Ruslan Sadreyev
- Howard Hughes Medical Institute, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Genetics, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Zhaoqing Zhang
- SAB Biosciences, Qiagen, 6951 Executive Way, Suite 100, Frederick, MD 21703, USA
| | - Attila Szanto
- Howard Hughes Medical Institute, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Genetics, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Bernhard Payer
- Howard Hughes Medical Institute, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Genetics, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Steven D. Sheridan
- Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Showming Kwok
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Stephen J. Haggarty
- Center for Human Genetic Research, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Mriganka Sur
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jason Alvarez
- Department of Genetics, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Alexander Gimelbrant
- Department of Genetics, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Maisam Mitalipova
- Whitehead Institute for Biomedical Sciences, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - James E. Kirby
- Department of Pathology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Jeannie T. Lee
- Howard Hughes Medical Institute, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Genetics, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| |
Collapse
|
75
|
Heterochromatin instability in cancer: from the Barr body to satellites and the nuclear periphery. Semin Cancer Biol 2012; 23:99-108. [PMID: 22722067 DOI: 10.1016/j.semcancer.2012.06.008] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 05/25/2012] [Accepted: 06/11/2012] [Indexed: 12/31/2022]
Abstract
In recent years it has been recognized that the development of cancer involves a series of not only genetic but epigenetic changes across the genome. At the same time, connections between epigenetic regulation, chromatin packaging, and overall nuclear architecture are increasingly appreciated. The cell-type specific organization of heterochromatin, established upon cell differentiation, is responsible for maintaining much of the genome in a repressed state, within a highly compartmentalized nucleus. This review focuses on recent evidence that in cancer the normal packaging and higher organization of heterochromatin is often compromised. Gross changes in nuclear morphology have long been a criterion for pathologic diagnosis of many cancers, but the specific nuclear components impacted, the mechanisms involved, and the implications for cancer progression have barely begun to emerge. We discuss recent findings regarding distinct heterochromatin types, including the inactive X chromosome, constitutive heterochromatin of peri/centric satellites, and the peripheral heterochromatic compartment (PHC). A theme developed here is that the higher-order organization of satellites and the peripheral heterochromatic compartment may be tightly linked, and that compromise of this organization may promote broad epigenomic imbalance in cancer. Recent studies into the potential role(s) of the breast cancer tumor suppressor, BRCA1, in maintaining heterochromatin will be highlighted. Many questions remain about this new area of cancer epigenetics, which is likely more important in cancer development and progression than widely appreciated. We propose that broad, stochastic compromise in heterochromatin maintenance would create a diversity of expression profiles, and thus a rich opportunity for one or more cells to emerge with a selective growth advantage and potential for neoplasia.
Collapse
|
76
|
[Application of the Barr body case in teaching practice of genetics]. YI CHUAN = HEREDITAS 2012; 34:503-8. [PMID: 22522168 DOI: 10.3724/sp.j.1005.2012.00503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
There are three classical problems at the chromosome level in cytogenetics, namely the formation mechanisms and effects of Barr body, polytenic chromosome, and lampbrush chromosome. Teachers and researchers keep sustaining attention to the Barr body because of the relationships between Barr body and the X chromosome dosage compensation effect in mammals, the human sex identification, and some human diseases. In our genetics teaching practice, we tried the case-based teaching method. We introduced the classical problems and research progress of the Barr body, as a line, into partial sections of our genetics teaching contents such as sex-linked genetic analysis, eukaryotic gene expression regulation, cancer genetic analysis, and genetic experiments. Finally, it will form a comprehensive summary of related knowledge of genetics through class discussion on the Barr body. We found that this teaching method can not only optimize the teaching contents of genetics, consolidate and widen students' basic knowledge, and help student to form the systemic and developmental views of a classical genetics problem, but also inspire students' interest in life sciences. Good teaching results have been achieved.
Collapse
|
77
|
Abstract
Cancer cells silence autosomal tumor suppressor genes by Knudson's two-hit mechanism in which loss-of-function mutations and then loss of heterozygosity occur at the tumor suppressor gene loci. However, the identification of X-linked tumor suppressor genes has challenged the traditional theory of 'two-hit inactivation' in tumor suppressor genes, introducing the novel concept that a single genetic hit can cause loss of tumor suppressor function. The mechanism through which these genes are silenced in human cancer is unclear, but elucidating the details will greatly enhance our understanding of the pathogenesis of human cancer. Here, we review the identification of X-linked tumor suppressor genes and discuss the potential mechanisms of their inactivation. In addition, we also discuss how the identification of X-linked tumor suppressor genes can potentially lead to new approaches in cancer therapy.
Collapse
Affiliation(s)
- Runhua Liu
- Division of Immunotherapy, Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA
- Department of Genetics, School of Medicine, University of Alabama at Birmingham and Comprehensive Cancer Center, Birmingham, AL, USA
| | - Mandy Kain
- Division of Immunotherapy, Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA
| | - Lizhong Wang
- Division of Immunotherapy, Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA
- Department of Genetics, School of Medicine, University of Alabama at Birmingham and Comprehensive Cancer Center, Birmingham, AL, USA
| |
Collapse
|
78
|
Vollebergh MA, Jonkers J, Linn SC. Genomic instability in breast and ovarian cancers: translation into clinical predictive biomarkers. Cell Mol Life Sci 2012; 69:223-45. [PMID: 21922196 PMCID: PMC11114988 DOI: 10.1007/s00018-011-0809-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 08/18/2011] [Accepted: 08/22/2011] [Indexed: 12/20/2022]
Abstract
Breast and ovarian cancer are among the most common malignancies diagnosed in women worldwide. Together, they account for the majority of cancer-related deaths in women. These cancer types share a number of features, including their association with hereditary cancer syndromes caused by heterozygous germline mutations in BRCA1 or BRCA2. BRCA-associated breast and ovarian cancers are hallmarked by genomic instability and high sensitivity to DNA double-strand break (DSB) inducing agents due to loss of error-free DSB repair via homologous recombination (HR). Recently, poly(ADP-ribose) polymerase inhibitors, a new class of drugs that selectively target HR-deficient tumor cells, have been shown to be highly active in BRCA-associated breast and ovarian cancers. This finding has renewed interest in hallmarks of HR deficiency and the use of other DSB-inducing agents, such as platinum salts or bifunctional alkylators, in breast and ovarian cancer patients. In this review we discuss the similarities between breast and ovarian cancer, the hallmarks of genomic instability in BRCA-mutated and BRCA-like breast and ovarian cancers, and the efforts to search for predictive markers of HR deficiency in order to individualize therapy in breast and ovarian cancer.
Collapse
Affiliation(s)
- Marieke A. Vollebergh
- Division of Molecular Biology, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
- Division of Medical Oncology, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands
| | - Jos Jonkers
- Division of Molecular Biology, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Sabine C. Linn
- Division of Molecular Biology, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
- Division of Medical Oncology, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands
| |
Collapse
|
79
|
Abstract
BACKGROUND X inactive-specific transcript (XIST) RNA is involved in X chromosome silencing in female cells and allows X chromosome equilibration with males. X inactive-specific transcript expression has been found to be dysregulated in a variety of human cancers when compared to normal cells; meanwhile, the inactivated X chromosome has been noted to be conspicuously absent in human cancer specimens, whereas X chromosome duplications are widely noted. The specific pathways whereby changes in X chromosome status and XIST expression occur in cancer remain incompletely described. Nevertheless, a role for XIST in BRCA1-mediated epigenetic activity has been proposed. METHODS Here we review the data regarding XIST expression and X chromosome status in a variety of female, male, and non-sex-related human cancers. CONCLUSIONS It is not yet known whether X chromosome duplication, XIST dysregulation, and over-expression of X-linked genes represent important factors in tumorgenesis or are simply a consequence of overall epigenetic instability in these cancers.
Collapse
|
80
|
BRCA1 tumour suppression occurs via heterochromatin-mediated silencing. Nature 2011; 477:179-84. [PMID: 21901007 PMCID: PMC3240576 DOI: 10.1038/nature10371] [Citation(s) in RCA: 354] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 07/15/2011] [Indexed: 12/24/2022]
Abstract
Mutations in tumor suppressor BRCA1 lead to breast and/or ovarian cancer. Here we show that loss of BRCA1 in mice results in transcriptional derepression of the tandemly repeated satellite DNA. BRCA1 deficiency is accompanied by reduction of condensed DNA regions in the genome and loss of ubiquitylation of histone H2A at satellite repeats. BRCA1 binds to satellite DNA regions in vivo and ubiquitylates H2A in vitro. Ectopic expression of an H2A fused to ubiquitin reverses the effects of BRCA1 loss, suggesting that BRCA1 maintains heterochromatin structure via ubiquitylation of histone H2A. Satellite DNA derepression was also observed mouse and human BRCA1 deficient breast cancers. Ectopic expression of satellite DNA can phenocopy BRCA1 loss in centrosome amplification, cell cycle checkpoint defects, DNA damage and genomic instability. We propose that the role of BRCA1 in maintaining global heterochromatin integrity accounts for many of its tumor suppressor functions.
Collapse
|
81
|
De La Fuente R, Baumann C, Viveiros MM. Role of ATRX in chromatin structure and function: implications for chromosome instability and human disease. Reproduction 2011; 142:221-34. [PMID: 21653732 PMCID: PMC3253860 DOI: 10.1530/rep-10-0380] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Functional differentiation of chromatin structure is essential for the control of gene expression, nuclear architecture, and chromosome stability. Compelling evidence indicates that alterations in chromatin remodeling proteins play an important role in the pathogenesis of human disease. Among these, α-thalassemia mental retardation X-linked protein (ATRX) has recently emerged as a critical factor involved in heterochromatin formation at mammalian centromeres and telomeres as well as facultative heterochromatin on the murine inactive X chromosome. Mutations in human ATRX result in an X-linked neurodevelopmental condition with various degrees of gonadal dysgenesis (ATRX syndrome). Patients with ATRX syndrome may exhibit skewed X chromosome inactivation (XCI) patterns, and ATRX-deficient mice exhibit abnormal imprinted XCI in the trophoblast cell line. Non-random or skewed XCI can potentially affect both the onset and severity of X-linked disease. Notably, failure to establish epigenetic modifications associated with the inactive X chromosome (Xi) results in several conditions that exhibit genomic and chromosome instability such as fragile X syndrome as well as cancer development. Insight into the molecular mechanisms of ATRX function and its interacting partners in different tissues will no doubt contribute to our understanding of the pathogenesis of ATRX syndrome as well as the epigenetic origins of aneuploidy. In turn, this knowledge will be essential for the identification of novel drug targets and diagnostic tools for cancer progression as well as the therapeutic management of global epigenetic changes commonly associated with malignant neoplastic transformation.
Collapse
Affiliation(s)
- Rabindranath De La Fuente
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, USA.
| | | | | |
Collapse
|
82
|
Antibody responses to NY-ESO-1 in primary breast cancer identify a subtype target for immunotherapy. PLoS One 2011; 6:e21129. [PMID: 21747904 PMCID: PMC3117860 DOI: 10.1371/journal.pone.0021129] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 05/20/2011] [Indexed: 01/22/2023] Open
Abstract
The highly immunogenic human tumor antigen NY-ESO-1 (ESO) is a target of choice for anti-cancer immune therapy. In this study, we assessed spontaneous antibody (Ab) responses to ESO in a large cohort of patients with primary breast cancer (BC) and addressed the correlation between the presence of anti-ESO Ab, the expression of ESO in the tumors and their characteristics. We found detectable Ab responses to ESO in 1% of the patients. Tumors from patients with circulating Ab to ESO exhibited common characteristics, being mainly hormone receptor (HR)− invasive ductal carcinomas of high grade, including both HER2− and HER2+ tumors. In line with these results, we detected ESO expression in 20% of primary HR− BC, including both ESO Ab+ and Ab− patients, but not in HR+ BC. Interestingly, whereas expression levels in ESO+ BC were not significantly different between ESO Ab+ and Ab− patients, the former had, in average, significantly higher numbers of tumor-infiltrated lymph nodes, indicating that lymph node invasion may be required for the development of spontaneous anti-tumor immune responses. Thus, the presence of ESO Ab identifies a tumor subtype of HR− (HER2− or HER2+) primary BC with frequent ESO expression and, together with the assessment of antigen expression in the tumor, may be instrumental for the selection of patients for whom ESO-based immunotherapy may complement standard therapy.
Collapse
|
83
|
Gibb EA, Brown CJ, Lam WL. The functional role of long non-coding RNA in human carcinomas. Mol Cancer 2011; 10:38. [PMID: 21489289 PMCID: PMC3098824 DOI: 10.1186/1476-4598-10-38] [Citation(s) in RCA: 1314] [Impact Index Per Article: 101.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Accepted: 04/13/2011] [Indexed: 12/15/2022] Open
Abstract
Long non-coding RNAs (lncRNAs) are emerging as new players in the cancer paradigm demonstrating potential roles in both oncogenic and tumor suppressive pathways. These novel genes are frequently aberrantly expressed in a variety of human cancers, however the biological functions of the vast majority remain unknown. Recently, evidence has begun to accumulate describing the molecular mechanisms by which these RNA species function, providing insight into the functional roles they may play in tumorigenesis. In this review, we highlight the emerging functional role of lncRNAs in human cancer.
Collapse
Affiliation(s)
- Ewan A Gibb
- British Columbia Cancer Agency Research Centre, Vancouver, Canada.
| | | | | |
Collapse
|
84
|
Hall LL, Lawrence JB. XIST RNA and architecture of the inactive X chromosome: implications for the repeat genome. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2011; 75:345-56. [PMID: 21447818 DOI: 10.1101/sqb.2010.75.030] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
XIST RNA paints and induces silencing of one X chromosome in mammalian female cells, providing a powerful model to investigate long-range chromosomal regulation. This chapter focuses on events downstream from the spread of XIST RNA across the interphase chromosome, to consider how this large noncoding RNA interacts with and silences a whole chromosome. Several lines of evidence are summarized that point to the involvement of repeat sequences in different aspects of the X-inactivation process. Although the "repeat genome" comprises close to half of the human genome, the potential for abundant repeats to contribute to genome regulation has been largely overlooked and may be underestimated. X inactivation has the potential to reveal roles of interspersed and other repeats in the genome. For example, evidence indicates that XIST RNA acts at the architectural level of the whole chromosome to induce formation of a silent core enriched for nongenic and repetitive (Cot-1) DNA, which corresponds to the DAPI-dense Barr body. Expression of repeat RNAs may contribute to chromosome remodeling, and evidence suggests that other types of repeat elements may be involved in escape from X inactivation. Despite great progress in decoding the rest of the genome, we suggest that the repeat genome may contain meaningful but complex language that remains to be better studied and understood.
Collapse
Affiliation(s)
- L L Hall
- Department of Cell Biology, University of Massachusetts Medical School, North Worcester, Massachusetts 01655, USA
| | | |
Collapse
|
85
|
Agrawal P, Dey P. Barr body in fine needle aspiration cytology of ovarian malignancies. Diagn Cytopathol 2011; 40:964-6. [PMID: 21416650 DOI: 10.1002/dc.21688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Accepted: 02/09/2011] [Indexed: 11/11/2022]
Abstract
The Barr body is the inactive X chromosome in a female somatic cell. It is readily identified as plano-convex structure of 2-3 micron in diameter on the periphery of the nuclear membrane. The aim of this study is to evaluate the significance of Barr body count in malignant ovarian tumors on fine needle aspiration cytology (FNAC) smears. In this retrospective study, Barr body was counted in FNAC smears of 20 successive malignant ovarian lesions and expressed as percentage. Mean (±SD) Barr body score was 2.4 ± 2.58. Minimum Barr body count was 1 and maximum was 9. The gross reduction of Barr body in ovarian neoplasms is an interesting cytomorphologic finding.
Collapse
Affiliation(s)
- Pallavi Agrawal
- Department of Cytology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | | |
Collapse
|
86
|
Karyagyna AS, Vassiliev MO, Ershova AS, Nurtdinov RN, Lossev IS. Probe-Level Universal Search (PLUS) algorithm for gender differentiation in affymetrix datasets. J Bioinform Comput Biol 2010; 8:553-77. [PMID: 20556862 DOI: 10.1142/s0219720010004823] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Revised: 01/22/2010] [Accepted: 02/12/2010] [Indexed: 11/18/2022]
Abstract
Affymetrix microarrays measure gene expression based on the intensity of hybridization of a panel of oligonucleotide probes (probe set) with mRNA. The signals from all probes within a probe set are converted into a single measure that represents the expression value of a gene. This step diminishes the number of independently measured parameters and eliminates from consideration individual "good-working" probes. We propose a new feature selection algorithm (Probe Level Universal Search or PLUS algorithm) for probe-level analysis of gene expression datasets. The algorithm evaluates the intensities of perfect-match Affymetrix probes individually and selects probes that allow one to distinguish two given classes of samples. The algorithm was used to differentiate the samples according to their gender ("gender differentiation"). The universal gender differentiating set of 3' Gene Affymetrix microarray probes was selected; the set consists of 38 probes from XIST gene of X-chromosome and 17 probes from five Y-chromosome genes: RPS4Y1, EIF1A, DDX3Y, JARID1D and USP9Y. The selection procedure based on the probes selected by PLUS algorithm differentiates the sex chromosome karyotype of the sample, reveals samples with incorrect gender labels and samples from patients with hereditary syndromes or cancer-associated chromosome abnormalities.
Collapse
Affiliation(s)
- Anna S Karyagyna
- NF Gamaleya Research Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, Institute of Agricultural Biotechnology, Moscow, Russia.
| | | | | | | | | |
Collapse
|
87
|
Ibrahim N, He L, Leong CO, Xing D, Karlan BY, Swisher EM, Rueda BR, Orsulic S, Ellisen LW. BRCA1-associated epigenetic regulation of p73 mediates an effector pathway for chemosensitivity in ovarian carcinoma. Cancer Res 2010; 70:7155-65. [PMID: 20807817 DOI: 10.1158/0008-5472.can-10-0668] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The majority of tumors arising in BRCA1 mutation carriers exhibit inactivation of p53, a key effector of cell death after DNA damage. Despite the loss of p53, BRCA1-deficient tumor cells exhibit increased sensitivity to cisplatin, and patients with BRCA1-associated ovarian carcinomas experience improved outcomes with platinum-based chemotherapy compared with sporadic cases. Although it is known that chemosensitivity in BRCA1-associated cancers is associated with unrepaired DNA damage, the specific effector pathway mediating the cellular response to platinum-induced damage in these tumors is poorly understood. Here, we show that the p53-related gene p73, encoding a proapoptotic protein that is linked to chemosensitivity in many settings, is upregulated through a novel epigenetic mechanism in both human and murine models of BRCA1-associated ovarian carcinoma. BRCA1-deficient ovarian carcinoma cells exhibit hypermethylation within a p73 regulatory region, which includes the binding site for the p73 transcriptional repressor ZEB1, leading to the abrogation of ZEB1 binding and increased expression of transactivating p73 isoforms (TAp73). Cisplatin chemotherapy induces TAp73 target genes specifically in BRCA1-deficient cells, and knockdown of TAp73 in these cells causes chemoresistance while having little or no effect on BRCA1-expressing tumor cells. In primary ovarian carcinomas, ZEB1 binding site methylation and TAp73 expression correlate with BRCA1 status and with clinical response. Together, these findings uncover a novel regulatory mechanism that supports the contribution of TAp73 as an important mediator of the response to platinum chemotherapy in a subset of ovarian carcinomas. TAp73 might represent a response predictor and potential therapeutic target for enhancing chemosensitivity in this disease.
Collapse
Affiliation(s)
- Nageatte Ibrahim
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Vincent Center for Reproductive Biology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
88
|
Fischer AH, Zhao C, Li QK, Gustafson KS, Eltoum IE, Tambouret R, Benstein B, Savaloja LC, Kulesza P. The cytologic criteria of malignancy. J Cell Biochem 2010; 110:795-811. [DOI: 10.1002/jcb.22585] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
89
|
Erwin JA, Lee JT. Characterization of X-chromosome inactivation status in human pluripotent stem cells. CURRENT PROTOCOLS IN STEM CELL BIOLOGY 2010; Chapter 1:Unit 1B.6. [PMID: 20127856 DOI: 10.1002/9780470151808.sc01b06s12] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
This unit describes a method of performing fluorescent in situ hybridization (FISH) of XIST and Cot-1 RNA in human pluripotent stem cells (hPSC) to characterize the epigenetic status of X-chromosome inactivation (XCI). hPSC laboratories commonly practice karyotypic analysis to monitor genetic stability; however, epigenetic stability is often overlooked. Several laboratories have recently shown that markers of XCI can be used as one effective screen to monitor the epigenetic status of hPSCs. Human embryonic stem cells (HESC) fall into three classes of XCI states: upregulating XIST upon differentiation, always expressing XIST in the undifferentiated and differentiated states, and never expressing XIST in the undifferentiated and differentiated states. Failure to express XIST represents an especially concerning state in hESC, as this state does not occur in healthy female cells but is often seen in malignancies. Herein, methods of carrying out XIST RNA and Cot-1 RNA FISH are described. FISH analysis of XIST RNA, unlike general expression analysis such as RT-PCR, allows for the classification of XCI on a single-cell level, enabling a quantitative determination of the degree of epigenetic change across the population. The complementary Cot-1 analysis measures the extent of repeat element expression throughout the nucleus and therefore enables determination, at a cytological level, of the extent to which the X chromosome is silent. Because the different steps of XCI are some of the first epigenetic changes to take place in differentiating hESC, analysis of the XCI state provides a first indication of an hESC culture's overall health.
Collapse
|
90
|
Hall LL, Byron M, Pageau G, Lawrence JB. AURKB-mediated effects on chromatin regulate binding versus release of XIST RNA to the inactive chromosome. ACTA ACUST UNITED AC 2009; 186:491-507. [PMID: 19704020 PMCID: PMC2733744 DOI: 10.1083/jcb.200811143] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
How XIST RNA strictly localizes across the inactive X chromosome is unknown; however, prophase release of human XIST RNA provides a clue. Tests of inhibitors that mimic mitotic chromatin modifications implicated an indirect role of PP1 (protein phosphatase 1), potentially via its interphase repression of Aurora B kinase (AURKB), which phosphorylates H3 and chromosomal proteins at prophase. RNA interference to AURKB causes mitotic retention of XIST RNA, unlike other mitotic or broad kinase inhibitors. Thus, AURKB plays an unexpected role in regulating RNA binding to heterochromatin, independent of mechanics of mitosis. H3 phosphorylation (H3ph) was shown to precede XIST RNA release, whereas results exclude H1ph involvement. Of numerous Xi chromatin (chromosomal protein) hallmarks, ubiquitination closely follows XIST RNA retention or release. Surprisingly, H3S10ph staining (but not H3S28ph) is excluded from Xi and is potentially linked to ubiquitination. Results suggest a model of multiple distinct anchor points for XIST RNA. This study advances understanding of RNA chromosome binding and the roles of AURKB and demonstrates a novel approach to manipulate and study XIST RNA.
Collapse
Affiliation(s)
- Lisa L Hall
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
| | | | | | | |
Collapse
|
91
|
Short B. Aurora B answers an XIST-ential question. J Biophys Biochem Cytol 2009. [PMCID: PMC2733741 DOI: 10.1083/jcb.1864if] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
92
|
Orlando FA, Brown KD. Unraveling breast cancer heterogeneity through transcriptomic and epigenomic analysis. Ann Surg Oncol 2009; 16:2270-9. [PMID: 19452229 DOI: 10.1245/s10434-009-0500-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 03/31/2009] [Accepted: 04/19/2009] [Indexed: 12/31/2022]
Abstract
Breast cancer diversity is histologically evident as various proliferative benign lesions, in situ carcinomas, and invasive carcinomas that may develop into distant metastases. Breast tumor molecular subtypes have been defined by genome-wide expression microarray technology and reveal associations between genetic alterations and the malignant phenotype. Early work has been conducted to use subtype-specific biomarkers to elucidate targeted treatment options early in the course of breast cancer progression. Additionally, DNA methylation is an epigenetic modification that contributes to breast cancer progression by transcriptionally silencing certain tumor suppressor genes. Among the genes characterized as targets for silencing are well-established tumor suppressors such as RASSF1A, RARB, SFN, and TGM2. Measuring elevated gene copy number and aberrant gene promoter methylation can further facilitate characterization of breast tumor molecular subtype; however, profiling of breast tumors based on epigenetic criteria has yet to be established. Epigenomic analysis has been investigated for clinical applicability, and it has great promise when used in combination with minimally invasive techniques for both diagnostic and prognostic purposes.
Collapse
Affiliation(s)
- Frank A Orlando
- Department of Surgery, University of Florida College of Medicine and UF Shands Cancer Center, Gainesville, FL, USA.
| | | |
Collapse
|
93
|
Sirchia SM, Tabano S, Monti L, Recalcati MP, Gariboldi M, Grati FR, Porta G, Finelli P, Radice P, Miozzo M. Misbehaviour of XIST RNA in breast cancer cells. PLoS One 2009; 4:e5559. [PMID: 19440381 PMCID: PMC2679222 DOI: 10.1371/journal.pone.0005559] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Accepted: 04/14/2009] [Indexed: 11/18/2022] Open
Abstract
A role of X chromosome inactivation process in the development of breast cancer have been suggested. In particular, the relationship between the breast cancer predisposing gene BRCA1 and XIST, the main mediator of X chromosome inactivation, has been intensely investigated, but still remains controversial. We investigated this topic by assessing XIST behaviour in different groups of breast carcinomas and in a panel of breast cancer cell lines both BRCA1 mutant and wild type. In addition, we evaluated the occurrence of broader defects of heterochromatin in relation to BRCA1 status in breast cancer cells. We provide evidence that in breast cancer cells BRCA1 is involved in XIST regulation on the active X chromosome, but not in its localization as previously suggested, and that XIST can be unusually expressed by an active X and can decorate it. This indicates that the detection of XIST cloud in cancer cell is not synonymous of the presence of an inactive X chromosome. Moreover, we show that global heterochromatin defects observed in breast tumor cells are independent of BRCA1 status. Our observations sheds light on a possible previously uncharacterized mechanism of breast carcinogenesis mediated by XIST misbehaviour, particularly in BRCA1-related cancers. Moreover, the significant higher levels of XIST-RNA detected in BRCA1-associated respect to sporadic basal-like cancers, opens the possibility to use XIST expression as a marker to discriminate between the two groups of tumors.
Collapse
Affiliation(s)
- Silvia M Sirchia
- Department of Medicine, Surgery and Dentistry, Medical Genetics Unit, Università degli Studi di Milano, Milano, Italy.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
94
|
Abstract
The ability to fuse cells is shared by many viruses, including common human pathogens and several endogenous viruses. Here we will discuss how cell fusion can link viruses to cancer, what types of cancers it can affect, how the existence of this link can be tested and how the hypotheses that we propose might affect the search for human oncogenic viruses. In particular, we will focus on the ability of cell fusion that is caused by viruses to induce chromosomal instability, a common affliction of cancer cells that has been thought to underlie the malignant properties of cancerous tumours.
Collapse
Affiliation(s)
- Dominik Duelli
- Department of Pathology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois 60064, USA.
| | | |
Collapse
|