1
|
Liu N, Low WY, Alinejad-Rokny H, Pederson S, Sadlon T, Barry S, Breen J. Seeing the forest through the trees: prioritising potentially functional interactions from Hi-C. Epigenetics Chromatin 2021; 14:41. [PMID: 34454581 PMCID: PMC8399707 DOI: 10.1186/s13072-021-00417-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 08/19/2021] [Indexed: 11/30/2022] Open
Abstract
Eukaryotic genomes are highly organised within the nucleus of a cell, allowing widely dispersed regulatory elements such as enhancers to interact with gene promoters through physical contacts in three-dimensional space. Recent chromosome conformation capture methodologies such as Hi-C have enabled the analysis of interacting regions of the genome providing a valuable insight into the three-dimensional organisation of the chromatin in the nucleus, including chromosome compartmentalisation and gene expression. Complicating the analysis of Hi-C data, however, is the massive amount of identified interactions, many of which do not directly drive gene function, thus hindering the identification of potentially biologically functional 3D interactions. In this review, we collate and examine the downstream analysis of Hi-C data with particular focus on methods that prioritise potentially functional interactions. We classify three groups of approaches: structural-based discovery methods, e.g. A/B compartments and topologically associated domains, detection of statistically significant chromatin interactions, and the use of epigenomic data integration to narrow down useful interaction information. Careful use of these three approaches is crucial to successfully identifying potentially functional interactions within the genome.
Collapse
Affiliation(s)
- Ning Liu
- Computational & Systems Biology, Precision Medicine Theme, South Australian Health & Medical Research Institute, SA, 5000, Adelaide, Australia
- Robinson Research Institute, University of Adelaide, SA, 5005, Adelaide, Australia
- Adelaide Medical School, University of Adelaide, SA, 5005, Adelaide, Australia
| | - Wai Yee Low
- The Davies Research Centre, School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, SA, 5371, Australia
| | - Hamid Alinejad-Rokny
- BioMedical Machine Learning Lab, The Graduate School of Biomedical Engineering, The University of New South Wales, NSW, 2052, Sydney, Australia
- Core Member of UNSW Data Science Hub, The University of New South Wales, 2052, Sydney, Australia
| | - Stephen Pederson
- Adelaide Medical School, University of Adelaide, SA, 5005, Adelaide, Australia
- Dame Roma Mitchell Cancer Research Laboratories (DRMCRL), Adelaide Medical School, University of Adelaide, SA, 5005, Adelaide, Australia
| | - Timothy Sadlon
- Robinson Research Institute, University of Adelaide, SA, 5005, Adelaide, Australia
- Women's & Children's Health Network, SA, 5006, North Adelaide, Australia
| | - Simon Barry
- Robinson Research Institute, University of Adelaide, SA, 5005, Adelaide, Australia
- Core Member of UNSW Data Science Hub, The University of New South Wales, 2052, Sydney, Australia
- Women's & Children's Health Network, SA, 5006, North Adelaide, Australia
| | - James Breen
- Computational & Systems Biology, Precision Medicine Theme, South Australian Health & Medical Research Institute, SA, 5000, Adelaide, Australia.
- Robinson Research Institute, University of Adelaide, SA, 5005, Adelaide, Australia.
- Adelaide Medical School, University of Adelaide, SA, 5005, Adelaide, Australia.
- South Australian Genomics Centre (SAGC), South Australian Health & Medical Research Institute (SAHMRI), SA, 5000, Adelaide, Australia.
| |
Collapse
|
2
|
Nakamura AJ. Beyond visualization of DNA double-strand breaks after radiation exposure. Int J Radiat Biol 2021; 98:522-527. [PMID: 33989105 DOI: 10.1080/09553002.2021.1930268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE Radiation science and radiation biology are fields where milestones have been set by numerous woman researchers, as represented by Marie Curie. This shows that it is a research field that is like a model of research diversity in modern society. In this review, I will describe what kind of research activities I have conducted as a Japanese woman researcher in the field of radiation science research. In addition, as a Japanese woman radiobiologist, I will describe the sense of mission I felt after the Fukushima Nuclear Power Plant accident and the research issues we must challenge in the future. CONCLUSION As a Japanese woman researcher, I have felt a bias in gender balance in the field of science in Japan. Also, after the Fukushima nuclear Power Plant accident, I sometimes felt that woman researchers would be more suitable when sharing research results and specialized knowledge with the general public. In recent years, the importance of STEAM (Science-Technology-Engineering-Art-Mathematics) education has been highlighted all over the world, and I believe that the field of radiation science falls exactly into the STEAM education category. STEAM education is for people of all gender. I hope that radiation science research will lead to various younger generations, and that the gender balance of Japanese scientific researchers will increase.
Collapse
Affiliation(s)
- Asako J Nakamura
- Department of Biological Science, College of Sciences, Ibaraki University, Mito, Japan
| |
Collapse
|
3
|
Savage SA, Walsh MF. Myelodysplastic Syndrome, Acute Myeloid Leukemia, and Cancer Surveillance in Fanconi Anemia. Hematol Oncol Clin North Am 2019; 32:657-668. [PMID: 30047418 DOI: 10.1016/j.hoc.2018.04.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Fanconi anemia (FA) is a DNA repair disorder associated with a high risk of cancer and bone marrow failure. Patients with FA may present with certain dysmorphic features, such as radial ray abnormalities, short stature, typical facies, bone marrow failure, or certain solid malignancies. Some patients may be recognized due to exquisite sensitivity after exposure to cancer therapy. FA is diagnosed by increased chromosomal breakage after exposure to clastogenic agents. It follows autosomal recessive and X-linked inheritance depending on the underlying genomic alterations. Recognizing patients with FA is important for therapeutic decisions, genetic counseling, and optimal clinical management.
Collapse
Affiliation(s)
- Sharon A Savage
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, 9609 Medical Center Drive, Room 6E456, MSC 9772, Bethesda, MD 20892-9772, USA
| | - Michael F Walsh
- Department of Medicine, Division of Solid Tumor, Memorial Sloan Kettering Cancer Center, 222 70th Street Room 412, New York, NY 10021, USA; Department of Medicine, Division of Clinical Cancer Genetics, Memorial Sloan Kettering Cancer Center, 222 70th Street Room 412, New York, NY 10021, USA; Department of Pediatrics, Memorial Sloan Kettering Cancer Center, 222 70th Street Room 412, New York, NY 10021, USA.
| |
Collapse
|
4
|
Abstract
Fanconi anemia is an inherited disease characterized by genomic instability, hypersensitivity to DNA cross-linking agents, bone marrow failure, short stature, skeletal abnormalities, and a high relative risk of myeloid leukemia and epithelial malignancies. The 21 Fanconi anemia genes encode proteins involved in multiple nuclear biochemical pathways that effect DNA interstrand crosslink repair. In the past, bone marrow failure was attributed solely to the failure of stem cells to repair DNA. Recently, non-canonical functions of many of the Fanconi anemia proteins have been described, including modulating responses to oxidative stress, viral infection, and inflammation as well as facilitating mitophagic responses and enhancing signals that promote stem cell function and survival. Some of these functions take place in non-nuclear sites and do not depend on the DNA damage response functions of the proteins. Dysfunctions of the canonical and non-canonical pathways that drive stem cell exhaustion and neoplastic clonal selection are reviewed, and the potential therapeutic importance of fully investigating the scope and interdependences of the canonical and non-canonical pathways is emphasized.
Collapse
Affiliation(s)
- Grover Bagby
- Departments of Medicine and Molecular and Medical Genetics, Division of Hematology and Medical Oncology, Knight Cancer Institute, Oregon Health & Science University, Portland, Oregon, USA
| |
Collapse
|
5
|
Lu L, Ge Y, Li ZH, Freie B, Clapp DW, Broxmeyer HE. CD34+++ Stem/Progenitor Cells Purified from Cryopreserved Normal Cord Blood can be Transduced with High Efficiency by a Retroviral Vector and Expanded Ex Vivo with Stable Integration and Expression of Fanconi Anemia Complementation C Gene. Cell Transplant 2017; 4:493-503. [PMID: 8520833 DOI: 10.1177/096368979500400510] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A future possibility for treatment of genetic diseases may be gene therapy using autologous cord blood (CB) stem/progenitor cells. This might require cryopreservation of CB stem/progenitor cells prior to purification, gene transduction, and ex vivo expansion of cells. To address this possibility, nonadherent low density T-lymphocyte depleted (NALT-) cells from fresh or cryopreserved cord blood were sorted for CD34+++ phenotype, transduced with a recombinant retroviral vector encoding Fanconi anemia complementation C (FACC) gene, and cells expanded ex vivo in suspension culture for 7 days with growth factors. The results demonstrate: 1) high recovery of viable cells after thawing; 2) high efficiency purification of CD34+++ cells from NALT- cells prior to and after cryopreservation; 3) high degree of expansion of nucleated cells and immature progenitors from CD34+++ cells before and after cryopreservation; 4) efficient transduction with stable integration and expression of newly introduced genes in cryopreserved and then sorted stem/progenitor cells, as detected prior to and after ex vivo expansion; and 5) high efficiency transduction of single isolated CD34+++ cells obtained from cryopreserved NALT- CB. This information should be of value for future studies evaluating the use of cryopreserved cord blood for gene transfer/gene therapy.
Collapse
Affiliation(s)
- L Lu
- Department of Medicine (Hematology/Oncology), Indiana University School of Medicine, Indianapolis 46202, USA
| | | | | | | | | | | |
Collapse
|
6
|
Palovcak A, Liu W, Yuan F, Zhang Y. Maintenance of genome stability by Fanconi anemia proteins. Cell Biosci 2017; 7:8. [PMID: 28239445 PMCID: PMC5320776 DOI: 10.1186/s13578-016-0134-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 12/07/2016] [Indexed: 12/20/2022] Open
Abstract
Persistent dysregulation of the DNA damage response and repair in cells causes genomic instability. The resulting genetic changes permit alterations in growth and proliferation observed in virtually all cancers. However, an unstable genome can serve as a double-edged sword by providing survival advantages in the ability to evade checkpoint signaling, but also creating vulnerabilities through dependency on alternative genomic maintenance factors. The Fanconi anemia pathway comprises an intricate network of DNA damage signaling and repair that are critical for protection against genomic instability. The importance of this pathway is underlined by the severity of the cancer predisposing syndrome Fanconi anemia which can be caused by biallelic mutations in any one of the 21 genes known thus far. This review delineates the roles of the Fanconi anemia pathway and the molecular actions of Fanconi anemia proteins in confronting replicative, oxidative, and mitotic stress.
Collapse
Affiliation(s)
- Anna Palovcak
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Gautier Building Room 311, 1011 NW 15th Street, Miami, FL 33136 USA
| | - Wenjun Liu
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Gautier Building Room 311, 1011 NW 15th Street, Miami, FL 33136 USA
| | - Fenghua Yuan
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Gautier Building Room 311, 1011 NW 15th Street, Miami, FL 33136 USA
| | - Yanbin Zhang
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Gautier Building Room 311, 1011 NW 15th Street, Miami, FL 33136 USA
| |
Collapse
|
7
|
Abstract
The balance between DNA damage, especially double strand breaks, and DNA damage repair is a critical determinant of chromosomal translocation frequency. The non-homologous end-joining repair (NHEJ) pathways seem to play the major role in the generation of chromosomal translocations. The "landscape" of chromosomal translocation identified in malignancies is largely due to selection processes which operate on the growth advantages conveyed to the cells by the functional consequences of chromosomal translocations (i.e., oncogenic fusion proteins and overexpression of oncogenes, both compromising tumor suppressor gene functions). Newer studies have shown that there is an abundance of local rearrangements in many tumors, like small deletions and inversions. A better understanding of the interplay between DNA repair mechanisms and the generation of tumorigenic translocations will, among many other things, depend on an improved understanding of DNA repair mechanisms and their interplay with chromatin and the 3D organization of the interphase nucleus.
Collapse
|
8
|
Flynn EK, Kamat A, Lach FP, Donovan FX, Kimble DC, Narisu N, Sanborn E, Boulad F, Davies SM, Gillio AP, Harris RE, MacMillan ML, Wagner JE, Smogorzewska A, Auerbach AD, Ostrander EA, Chandrasekharappa SC. Comprehensive analysis of pathogenic deletion variants in Fanconi anemia genes. Hum Mutat 2015; 35:1342-53. [PMID: 25168418 DOI: 10.1002/humu.22680] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 08/09/2014] [Indexed: 11/06/2022]
Abstract
Fanconi anemia (FA) is a rare recessive disease resulting from mutations in one of at least 16 different genes. Mutation types and phenotypic manifestations of FA are highly heterogeneous and influence the clinical management of the disease. We analyzed 202 FA families for large deletions, using high-resolution comparative genome hybridization arrays, single-nucleotide polymorphism arrays, and DNA sequencing. We found pathogenic deletions in 88 FANCA, seven FANCC, two FANCD2, and one FANCB families. We find 35% of FA families carry large deletions, accounting for 18% of all FA pathogenic variants. Cloning and sequencing across the deletion breakpoints revealed that 52 FANCA deletion ends, and one FANCC deletion end extended beyond the gene boundaries, potentially affecting neighboring genes with phenotypic consequences. Seventy-five percent of the FANCA deletions are Alu-Alu mediated, predominantly by AluY elements, and appear to be caused by nonallelic homologous recombination. Individual Alu hotspots were identified. Defining the haplotypes of four FANCA deletions shared by multiple families revealed that three share a common ancestry. Knowing the exact molecular changes that lead to the disease may be critical for a better understanding of the FA phenotype, and to gain insight into the mechanisms driving these pathogenic deletion variants.
Collapse
Affiliation(s)
- Elizabeth K Flynn
- Cancer Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, Maryland, 20892
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Romick-Rosendale LE, Lui VWY, Grandis JR, Wells SI. The Fanconi anemia pathway: repairing the link between DNA damage and squamous cell carcinoma. Mutat Res 2013; 743-744:78-88. [PMID: 23333482 DOI: 10.1016/j.mrfmmm.2013.01.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 01/03/2013] [Accepted: 01/05/2013] [Indexed: 12/18/2022]
Abstract
Fanconi anemia (FA) is a rare inherited recessive disease caused by mutations in one of fifteen genes known to encode FA pathway components. In response to DNA damage, nuclear FA proteins associate into high molecular weight complexes through a cascade of post-translational modifications and physical interactions, followed by the repair of damaged DNA. Hematopoietic cells are particularly sensitive to the loss of these interactions, and bone marrow failure occurs almost universally in FA patients. FA as a disease is further characterized by cancer susceptibility, which highlights the importance of the FA pathway in tumor suppression, and will be the focus of this review. Acute myeloid leukemia is the most common cancer type, often subsequent to bone marrow failure. However, FA patients are also at an extreme risk of squamous cell carcinoma (SCC) of the head and neck and gynecological tract, with an even greater incidence in those individuals who have received a bone marrow transplant and recovered from hematopoietic disease. FA tumor suppression in hematopoietic versus epithelial compartments could be mechanistically similar or distinct. Definition of compartment specific FA activities is now critical to assess the effects of today's bone marrow failure treatments on tomorrow's solid tumor development. It is our hope that current therapies can then be optimized to decrease the risk of malignant transformation in both hematopoietic and epithelial cells. Here we review our current understanding of the mechanisms of action of the Fanconi anemia pathway as it contributes to stress responses, DNA repair and squamous cell carcinoma susceptibility.
Collapse
Affiliation(s)
- Lindsey E Romick-Rosendale
- Division of Oncology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Vivian W Y Lui
- Department of Otolaryngology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Jennifer R Grandis
- Department of Otolaryngology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Susanne I Wells
- Division of Oncology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA.
| |
Collapse
|
10
|
Crossan GP, Patel KJ. The Fanconi anaemia pathway orchestrates incisions at sites of crosslinked DNA. J Pathol 2011; 226:326-37. [PMID: 21956823 DOI: 10.1002/path.3002] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 09/21/2011] [Accepted: 09/22/2011] [Indexed: 12/18/2022]
Abstract
Fanconi anaemia (FA) is a rare, autosomal recessive, genetically complex, DNA repair deficiency syndrome in man. Patients with FA exhibit a heterogeneous spectrum of clinical features. The most significant and consistent phenotypic characteristics are stem cell loss, causing progressive bone marrow failure and sterility, diverse developmental abnormalities and a profound predisposition to neoplasia. To date, 15 genes have been identified, biallelic disruption of any one of which results in this clinically defined syndrome. It is now apparent that all 15 gene products act in a common process to maintain genome stability. At the molecular level, a fundamental defect in DNA repair underlies this complex phenotype. Cells derived from FA patients spontaneously accumulate broken chromosomes and exhibit a marked sensitivity to DNA-damaging chemotherapeutic agents. Despite complementation analysis defining many components of the FA DNA repair pathway, no direct link to DNA metabolism was established until recently. First, it is now evident that the FA pathway is required to make incisions at the site of damaged DNA. Second, a specific component of the FA pathway has been identified that regulates nucleases previously implicated in DNA interstrand crosslink repair. Taken together, these data provide genetic and biochemical evidence that the FA pathway is a bona fide DNA repair pathway that directly mediates DNA repair transactions, thereby elucidating the specific molecular defect in human Fanconi anaemia.
Collapse
Affiliation(s)
- Gerry P Crossan
- MRC Laboratory of Molecular Biology, Division of Protein and Nucleic Acid Chemistry, Cambridge, UK.
| | | |
Collapse
|
11
|
Abstract
Fanconi anemia (FA) is a human disease of bone marrow failure, leukemia, squamous cell carcinoma, and developmental anomalies, including hypogonadism and infertility. Bone marrow transplants improve hematopoietic phenotypes but do not prevent other cancers. FA arises from mutation in any of the 15 FANC genes that cooperate to repair double stranded DNA breaks by homologous recombination. Zebrafish has a single ortholog of each human FANC gene and unexpectedly, mutations in at least two of them (fancl and fancd1(brca2)) lead to female-to-male sex reversal. Investigations show that, as in human, zebrafish fanc genes are required for genome stability and for suppressing apoptosis in tissue culture cells, in embryos treated with DNA damaging agents, and in meiotic germ cells. The sex reversal phenotype requires the action of Tp53 (p53), an activator of apoptosis. These results suggest that in normal sex determination, zebrafish oocytes passing through meiosis signal the gonadal soma to maintain expression of aromatase, an enzyme that converts androgen to estrogen, thereby feminizing the gonad and the individual. According to this model, normal male and female zebrafish differ in genetic factors that control the strength of the late meiotic oocyte-derived signal, probably by regulating the number of meiotic oocytes, which environmental factors can also alter. Transcripts from fancd1(brca2) localize at the animal pole of the zebrafish oocyte cytoplasm and are required for normal oocyte nuclear architecture, for normal embryonic development, and for preventing ovarian tumors. Embryonic DNA repair and sex reversal phenotypes provide assays for the screening of small molecule libraries for therapeutic substances for FA.
Collapse
|
12
|
Abstract
The FA (Fanconi anaemia) FANCD2 protein is pivotal in the cellular response to DNA interstrand cross-links. Establishing cells expressing exogenous FANCD2 has proven to be difficult compared with other DNA repair genes. We find that in transformed normal human fibroblasts, exogenous nuclear expression of FANCD2 induces apoptosis, dependent specifically on exons 10-13. This is the same region required for interaction with the histone acetyltransferase, Tip60. Deletion of exons 10-13 from FANCD2 N-terminal constructs (nucleotides 1-1100) eliminates the binary interaction with Tip60 and the cellular apoptotic response; moreover, cells can stably express FANCD2 at high levels if Tip60 is depleted. The results indicate that FANCD2-sponsored apoptosis requires an interaction with Tip60 and depends on Tip60.
Collapse
|
13
|
Selection and the cell cycle: positive Darwinian selection in a well-known DNA damage response pathway. J Mol Evol 2010; 71:444-57. [PMID: 21057781 DOI: 10.1007/s00239-010-9399-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Accepted: 10/06/2010] [Indexed: 10/18/2022]
Abstract
Cancer is a common occurrence in multi-cellular organisms and is not strictly limited to the elderly in a population. It is therefore possible that individuals with genotypes that protect against early onset cancers have a selective advantage. In this study the patterns of mutation in the proteins of a well-studied DNA damage response pathway have been examined for evidence of adaptive evolutionary change. Using a maximum likelihood framework and the mammalian species phylogeny, together with codon models of evolution, selective pressure variation across the interacting network of proteins has been detected. The presence of signatures of adaptive evolution in BRCA1 and BRCA2 has already been documented but the effect on the entire network of interacting proteins in this damage response pathway has, until now, been unknown. Positive selection is evident throughout the network with a total of 11 proteins out of 15 examined displaying patterns of substitution characteristic of positive selection. It is also shown here that modern human populations display evidence of an ongoing selective sweep in 9 of these DNA damage repair proteins. The results presented here provide the community with new residues that may be relevant to cancer susceptibility while also highlighting those proteins where human and mouse have undergone lineage-specific functional shift. An understanding of this damage response pathway from an evolutionary perspective will undoubtedly contribute to future cancer treatment approaches.
Collapse
|
14
|
Kee Y, D'Andrea AD. Expanded roles of the Fanconi anemia pathway in preserving genomic stability. Genes Dev 2010; 24:1680-94. [PMID: 20713514 DOI: 10.1101/gad.1955310] [Citation(s) in RCA: 246] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Studying rare human genetic diseases often leads to a better understanding of normal cellular functions. Fanconi anemia (FA), for example, has elucidated a novel DNA repair mechanism required for maintaining genomic stability and preventing cancer. The FA pathway, an essential tumor-suppressive pathway, is required for protecting the human genome from a specific type of DNA damage; namely, DNA interstrand cross-links (ICLs). In this review, we discuss the recent progress in the study of the FA pathway, such as the identification of new FANCM-binding partners and the identification of RAD51C and FAN1 (Fanconi-associated nuclease 1) as new FA pathway-related proteins. We also focus on the role of the FA pathway as a potential regulator of DNA repair choices in response to double-strand breaks, and its novel functions during the mitotic phase of the cell cycle.
Collapse
Affiliation(s)
- Younghoon Kee
- Department of Radiation Oncology and Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | | |
Collapse
|
15
|
Yarde DN, Oliveira V, Mathews L, Wang X, Villagra A, Boulware D, Shain KH, Hazlehurst LA, Alsina M, Chen DT, Beg AA, Dalton WS. Targeting the Fanconi anemia/BRCA pathway circumvents drug resistance in multiple myeloma. Cancer Res 2010; 69:9367-75. [PMID: 19934314 DOI: 10.1158/0008-5472.can-09-2616] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The Fanconi anemia/BRCA (FA/BRCA) DNA damage repair pathway plays a pivotal role in the cellular response to replicative stress induced by DNA alkylating agents and greatly influences drug response in cancer treatment. We recently reported that FA/BRCA genes are overexpressed and causative for drug resistance in human melphalan-resistant multiple myeloma cell lines. However, the transcriptional regulation of the FA/BRCA pathway is not understood. In this report, we describe for the first time a novel function of the NF-kappaB subunits, RelB/p50, as transcriptional activators of the FA/BRCA pathway. Specifically, our findings point to constitutive phosphorylation of IkappaB kinase alpha and subsequent alterations in FANCD2 expression and function as underlying events leading to melphalan resistance in repeatedly exposed multiple myeloma cells. Inhibiting NF-kappaB by small interfering RNA, blocking the IkappaB kinase complex with BMS-345541, or using the proteasome inhibitor bortezomib drastically reduced FA/BRCA gene expression and FANCD2 protein expression in myeloma cells, resulting in diminished DNA damage repair and enhanced melphalan sensitivity. Importantly, we also found that bortezomib decreases FA/BRCA gene expression in multiple myeloma patients. These results show for the first time that NF-kappaB transcriptionally regulates the FA/BRCA pathway and provide evidence for targeting Fanconi anemia-mediated DNA repair to enhance chemotherapeutic response and circumvent drug resistance in myeloma patients.
Collapse
Affiliation(s)
- Danielle N Yarde
- Cancer Biology Ph.D. Program, University of South Florida, Tampa, Florida 33612, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Abstract
Fanconi Anemia (FA) is an inherited genomic instability disorder, caused by mutations in genes regulating replication-dependent removal of interstrand DNA crosslinks. The Fanconi Anemia pathway is thought to coordinate a complex mechanism that enlists elements of three classic DNA repair pathways, namely homologous recombination, nucleotide excision repair, and mutagenic translesion synthesis, in response to genotoxic insults. To this end, the Fanconi Anemia pathway employs a unique nuclear protein complex that ubiquitinates FANCD2 and FANCI, leading to formation of DNA repair structures. Lack of obvious enzymatic activities among most FA members has made it challenging to unravel its precise modus operandi. Here we review the current understanding of how the Fanconi Anemia pathway components participate in DNA repair and discuss the mechanisms that regulate this pathway to ensure timely, efficient, and correct restoration of chromosomal integrity.
Collapse
Affiliation(s)
- George-Lucian Moldovan
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA
| | | |
Collapse
|
17
|
Gari K, Constantinou A. The role of the Fanconi anemia network in the response to DNA replication stress. Crit Rev Biochem Mol Biol 2009; 44:292-325. [PMID: 19728769 DOI: 10.1080/10409230903154150] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Fanconi anemia is a genetically heterogeneous disorder associated with chromosome instability and a highly elevated risk for developing cancer. The mutated genes encode proteins involved in the cellular response to DNA replication stress. Fanconi anemia proteins are extensively connected with DNA caretaker proteins, and appear to function as a hub for the coordination of DNA repair with DNA replication and cell cycle progression. At a molecular level, however, the raison d'être of Fanconi anemia proteins still remains largely elusive. The thirteen Fanconi anemia proteins identified to date have not been embraced into a single and defined biological process. To help put the Fanconi anemia puzzle into perspective, we begin this review with a summary of the strategies employed by prokaryotes and eukaryotes to tolerate obstacles to the progression of replication forks. We then summarize what we know about Fanconi anemia with an emphasis on biochemical aspects, and discuss how the Fanconi anemia network, a late acquisition in evolution, may function to permit the faithful and complete duplication of our very large vertebrate chromosomes.
Collapse
Affiliation(s)
- Kerstin Gari
- DNA Damage Response Laboratory, Cancer Research UK, London Research Institute, Clare Hall Laboratories, South Mimms, UK
| | | |
Collapse
|
18
|
Validation of Fanconi anemia complementation Group A assignment using molecular analysis. Genet Med 2009; 11:183-92. [PMID: 19367192 DOI: 10.1097/gim.0b013e318193ba67] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
PURPOSE Fanconi anemia is a genetically heterogeneous chromosomal breakage disorder exhibiting a high degree of clinical variability. Clinical diagnoses are confirmed by testing patient cells for increased sensitivity to crosslinking agents. Fanconi anemia complementation group assignment, essential for efficient molecular diagnosis of the disease, had not been validated for clinical application before this study. The purpose of this study was (1) confirmation of the accuracy of Fanconi anemia complementation group assignment to Group A (FANCA) and (2) development of a rapid mutation detection strategy that ensures the efficient capture of all FANCA mutations. METHODS Using fibroblasts from 29 patients, diagnosis of Fanconi anemia and assignment to complementation Group A was made through breakage analysis studies. FANCA coding and flanking sequences were analyzed using denaturing high pressure liquid chromatography, sequencing, and multiplex ligation-dependent probe amplification. Patients in which two mutations were not identified were analyzed by cDNA sequencing. Patients with no mutations were sequenced for mutations in FANCC, G, E, and F. RESULTS Of the 56 putative mutant alleles studied, 89% had an identifiable FANCA pathogenic mutation. Eight unique novel mutations were identified. CONCLUSION Complementation assignment to Group A was validated in a clinical laboratory setting using our FANCA rapid molecular testing strategy.
Collapse
|
19
|
Titus TA, Yan YL, Wilson C, Starks AM, Frohnmayer JD, Bremiller RA, Cañestro C, Rodriguez-Mari A, He X, Postlethwait JH. The Fanconi anemia/BRCA gene network in zebrafish: embryonic expression and comparative genomics. Mutat Res 2008; 668:117-32. [PMID: 19101574 DOI: 10.1016/j.mrfmmm.2008.11.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Accepted: 11/23/2008] [Indexed: 10/21/2022]
Abstract
Fanconi anemia (FA) is a genetic disease resulting in bone marrow failure, high cancer risks, and infertility, and developmental anomalies including microphthalmia, microcephaly, hypoplastic radius and thumb. Here we present cDNA sequences, genetic mapping, and genomic analyses for the four previously undescribed zebrafish FA genes (fanci, fancj, fancm, and fancn), and show that they reverted to single copy after the teleost genome duplication. We tested the hypothesis that FA genes are expressed during embryonic development in tissues that are disrupted in human patients by investigating fanc gene expression patterns. We found fanc gene maternal message, which can provide Fanc proteins to repair DNA damage encountered in rapid cleavage divisions. Zygotic expression was broad but especially strong in eyes, central nervous system and hematopoietic tissues. In the pectoral fin bud at hatching, fanc genes were expressed specifically in the apical ectodermal ridge, a signaling center for fin/limb development that may be relevant to the radius/thumb anomaly of FA patients. Hatching embryos expressed fanc genes strongly in the oral epithelium, a site of squamous cell carcinomas in FA patients. Larval and adult zebrafish expressed fanc genes in proliferative regions of the brain, which may be related to microcephaly in FA. Mature ovaries and testes expressed fanc genes in specific stages of oocyte and spermatocyte development, which may be related to DNA repair during homologous recombination in meiosis and to infertility in human patients. The intestine strongly expressed some fanc genes specifically in proliferative zones. Our results show that zebrafish has a complete complement of fanc genes in single copy and that these genes are expressed in zebrafish embryos and adults in proliferative tissues that are often affected in FA patients. These results support the notion that zebrafish offers an attractive experimental system to help unravel mechanisms relevant not only to FA, but also to breast cancer, given the involvement of fancj (brip1), fancn (palb2) and fancd1 (brca2) in both conditions.
Collapse
Affiliation(s)
- Tom A Titus
- Institute of Neuroscience, University of Oregon, 1425 E. 13th Avenue, Eugene, OR 97403, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Abstract
The ubiquitin system of protein modification has emerged as a crucial mechanism involved in the regulation of a wide array of cellular processes. As our knowledge of the pathways in this system has grown, so have the ties between the protein ubiquitin and human disease. The power of the ubiquitin system for therapeutic benefit blossomed with the approval of the proteasome inhibitor Velcade in 2003 by the FDA. Current drug discovery activities in the ubiquitin system seek to (i) expand the development of new proteasome inhibitors with distinct mechanisms of action and improved bioavailability, and (ii) validate new targets. This review summarizes our current understanding of the role of the ubiquitin system in various human diseases ranging from cancer, viral infection and neurodegenerative disorders to muscle wasting, diabetes and inflammation. I provide an introduction to the ubiquitin system, highlight some emerging relationships between the ubiquitin system and disease, and discuss current and future efforts to harness aspects of this potentially powerful system for improving human health. Republished from Current BioData's Targeted Proteins database (TPdb; ).
Collapse
|
21
|
García MJ, Benítez J. The Fanconi anaemia/BRCA pathway and cancer susceptibility. Searching for new therapeutic targets. Clin Transl Oncol 2008; 10:78-84. [PMID: 18258506 DOI: 10.1007/s12094-008-0160-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Breast cancer is one of the most frequent cancers in the world. The majority of cases are sporadic but around 15% show some type of familial aggregation and about 5% exhibit a clear hereditary pattern. Common and rare low- moderate-penetrance genes, and high-penetrance genes are thought to explain the genetic susceptibility to the disease. Only around 20% of the inherited risk to breast cancer is explained by germline mutations in the known high-penetrance susceptibility genes BRCA1 and BRCA2. Mutations in genes such as TP53 and PTEN have also been linked with high risk for breast cancer within specific cancer syndromes and rare germline variants in genes such as CHEK2 and ATM have been found to confer modest risk to breast cancer. However, we can say that less than 30% of familial risk of breast cancer is due to known genes. Identification in 2002 of the Fanconi anaemia (FA) gene FANCD1 as BRCA2 and recent studies indicating that heterozygous mutations in FANCN/PALB2 and FANCJ/ BRIP1 predispose to breast cancer have emphasised an important connection between the FA and BRCA pathway. Here we review the emerging DNA-damage response network consisting of FA and BRCA proteins, summarise what is currently known about the direct involvement of these molecules in breast cancer susceptibility and discuss the prospect offered by this pathway in order to identify more breast cancer related genes. We finally present the current stage of therapeutic options specifically targeting the FA/BRCA pathway and summarise the challenges this field encounters.
Collapse
Affiliation(s)
- Maria José García
- Group of Human Genetics, Human Cancer Genetics Program, Spanish National Cancer Centre (CNIO) and Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | | |
Collapse
|
22
|
AMD3100 synergizes with G-CSF to mobilize repopulating stem cells in Fanconi anemia knockout mice. Exp Hematol 2008; 36:1084-90. [PMID: 18495331 DOI: 10.1016/j.exphem.2008.03.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 03/18/2008] [Accepted: 03/21/2008] [Indexed: 11/20/2022]
Abstract
Fanconi anemia (FA) is a heterogeneous inherited disorder characterized by a progressive bone marrow (BM) failure and susceptibility to myeloid leukemia. Genetic correction using gene-transfer technology is one potential therapy. A major hurdle in applying this technology in FA patients is the inability of granulocyte colony-stimulating factor (G-CSF) to mobilize sufficient numbers of hematopoietic stem (HSC)/progenitor cells (HPC) from the BM to the peripheral blood. Whether the low number of CD34(+) cells is a result of BM hypoplasia or an inability of G-CSF to adequately mobilize FA HSC/HPC remains incompletely understood. Here we use competitive repopulation of lethally irradiated primary and secondary recipients to show that in two murine models of FA, AMD3100 synergizes with G-CSF resulting in a mobilization of HSC, whereas G-CSF alone fails to mobilize stem cells even in the absence of hypoplasia.
Collapse
|
23
|
Macé G, Briot D, Guervilly JH, Rosselli F. L'anémie de Fanconi : aspects cellulaires et moléculaires. ACTA ACUST UNITED AC 2007; 55:19-28. [PMID: 16904272 DOI: 10.1016/j.patbio.2006.04.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Accepted: 04/05/2006] [Indexed: 11/25/2022]
Abstract
Fanconi anemia (FA) is a recessive human cancer prone syndrome featuring bone marrow failure, developmental abnormalities and hypersensitivity to DNA crosslinking agents exposure. 11 among 12 FA gene have been isolated. The biochemical functions of the FANC proteins remain poorly understood. Anyhow, to cope with DNA crosslinks a cell needs a functional FANC pathway. Moreover, the FANC proteins appear to be involved in cell protection against oxidative damage and in the control of TNF-alpha activity. In this review, we describe the current understanding of the FANC pathway and we present how it may be integrated in the complex networks of proteins involved in maintaining the cellular homeostasis.
Collapse
Affiliation(s)
- G Macé
- Equipe Voie FANC/BRCA et Cancer FRE 2939 CNRS, Institut Gustave-Roussy, 39, rue Camille-Desmoulins, 94805 Villejuif, France
| | | | | | | |
Collapse
|
24
|
Vilcheck SK, Ceryak S, O'Brien TJ, Patierno SR. FANCD2 monoubiquitination and activation by hexavalent chromium [Cr(VI)] exposure: activation is not required for repair of Cr(VI)-induced DSBs. Mutat Res 2006; 610:21-30. [PMID: 16893675 PMCID: PMC2080350 DOI: 10.1016/j.mrgentox.2006.06.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2006] [Indexed: 12/29/2022]
Abstract
Fanconi anemia (FA) is a rare autosomal recessive disorder characterized by congenital abnormalities, progressive bone marrow failure, and cancer susceptibility. FA cells are hypersensitive to DNA crosslinking agents. FA is a genetically heterogeneous disease with at least 11 complementation groups. The eight cloned FA proteins interact in a common pathway with established DNA-damage-response proteins, including BRCA1 and ATM. Six FA proteins (A, C, E, F, G, and L) regulate the monoubiquitination of FANCD2 after DNA damage by crosslinking agents, which targets FANCD2 to BRCA1 nuclear foci containing BRCA2 (FANCD1) and RAD51. Some forms of hexavalent chromium [Cr(VI)] are implicated as respiratory carcinogens and induce several types of DNA lesions, including DNA interstrand crosslinks. We have shown that FA-A fibroblasts are hypersensitive to both Cr(VI)-induced apoptosis and clonogenic lethality. Here we show that Cr(VI) treatment induced monoubiquitination of FANCD2 in normal human fibroblasts, providing the first molecular evidence of Cr(VI)-induced activation of the FA pathway. FA-A fibroblasts demonstrated no FANCD2 monoubiquitination, in keeping with the requirement of FA-A for this modification. We also found that Cr(VI) treatment induced significantly more S-phase-dependent DNA double strand breaks (DSBs), as measured by gamma-H2AX expression, in FA-A fibroblasts compared to normal cells. However, and notably, DSBs were repaired equally in both normal and FA-A fibroblasts during recovery from Cr(VI) treatment. While previous research on FA has defined the genetic causes of this disease, it is critical in terms of individual risk assessment to address how cells from FA patients respond to genotoxic insult.
Collapse
Affiliation(s)
- Susan K Vilcheck
- Department of Pharmacology and Physiology, The George Washington University Medical Center, 2300 Eye Street, NW, Washington, DC 20037, United States
| | | | | | | |
Collapse
|
25
|
Abstract
The Fanconi anemia (FA) pathway consists of a unique, multi-subunit E3 ubiquitin ligase complex that is activated in a replication and DNA-damage dependent mechanism. This FA core complex possesses a putative helicase and an E3 ubiquitin ligase subunit, is assembled in both the nucleoplasm and in chromatin, and is required for the mono-ubiquitination of FANCD2, a downstream FA protein, following genotoxic stress. Clinically, absence of the FA pathway results in congenital defects, bone marrow failure, and cancer predisposition. At the cellular level, this pathway is required for chromosomal stability and cellular resistance to DNA interstrand crosslinkers (ICLs) such as mitomycin C (MMC). A general model has emerged for the FA pathway as an arm of the DNA-damage response following ICLs. This review will summarize the current understanding of the FA core complex and propose a model for its activity.
Collapse
Affiliation(s)
- Allan M Gurtan
- Biological and Biomedical Sciences Program, Harvard Medical School, Boston, Massachusetts 02115, USA
| | | |
Collapse
|
26
|
Gurtan AM, Stuckert P, D'Andrea AD. The WD40 Repeats of FANCL Are Required for Fanconi Anemia Core Complex Assembly. J Biol Chem 2006; 281:10896-905. [PMID: 16474167 DOI: 10.1074/jbc.m511411200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fanconi anemia (FA) is an autosomal recessive disorder characterized by aplastic anemia, cancer susceptibility, and cellular sensitivity to mitomycin C. Eight of the 11 cloned Fanconi anemia gene products (FANCA, -B, -C, -E, -F, -G, -L, and -M) form a multisubunit nuclear complex (FA core complex) required for monoubiquitination of a downstream FA protein, FANCD2. FANCL, which possesses three WD40 repeats and a plant homeodomain (PHD), is the putative E3 ubiquitin ligase subunit of the FA complex. Here, we demonstrate that the WD40 repeats of FANCL are required for interaction with other subunits of the FA complex. The PHD is dispensable for this interaction, although it is required for FANCD2 mono-ubiquitination. The PHD of FANCL also shares sequence similarity to the canonical RING finger of c-CBL, including a conserved tryptophan required for E2 binding by c-CBL. Mutation of this tryptophan in the FANCL PHD significantly impairs in vivo mono-ubiquitination of FANCD2 and in vitro auto-ubiquitination activity, and partially impairs restoration of mitomycin C resistance. We propose a model in which FANCL, via its WD40 region, binds the FA complex and, via its PHD, recruits an as-yet-unidentified E2 for mono-ubiquitination of FANCD2.
Collapse
Affiliation(s)
- Allan M Gurtan
- Biological and Biomedical Sciences Program, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | | |
Collapse
|
27
|
Léveillé F, Ferrer M, Medhurst AL, Laghmani EH, Rooimans MA, Bier P, Steltenpool J, Titus TA, Postlethwait JH, Hoatlin ME, Joenje H, de Winter JP. The nuclear accumulation of the Fanconi anemia protein FANCE depends on FANCC. DNA Repair (Amst) 2006; 5:556-65. [PMID: 16513431 DOI: 10.1016/j.dnarep.2006.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Revised: 01/10/2006] [Accepted: 01/13/2006] [Indexed: 01/18/2023]
Abstract
The Fanconi anemia (FA) protein FANCE is an essential component of the nuclear FA core complex, which is required for monoubiquitination of the downstream target FANCD2, an important step in the FA pathway of DNA cross-link repair. FANCE is predominantly localized in the nucleus and acts as a molecular bridge between the FA core complex and FANCD2, through direct binding of both FANCC and FANCD2. At present, it is poorly understood how the nuclear accumulation of FANCE is regulated and therefore we investigated the nuclear localization of this FA protein. We found that FANCE has a strong tendency to localize in the nucleus, since the addition of a nuclear export signal does not interfere with the nuclear localization of FANCE. We also demonstrate that the nuclear accumulation of FANCE does not rely solely on its nuclear localization signal motifs, but also on FANCC. The other FA proteins are not involved in the nuclear accumulation of FANCE, indicating a tight relationship between FANCC and FANCE, as suggested from their direct interaction. Finally, we show that the region of FANCE interacting with FANCC appears to be different from the region involved in binding FANCD2. This strengthens the idea that FANCE recruits FANCD2 to the core complex, without interfering with the binding of FANCC.
Collapse
Affiliation(s)
- France Léveillé
- Department of Clinical Genetics and Human Genetics, VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Digweed M. Genomic Instability in Fanconi Anaemia and Nijmegen Breakage Syndrome. Genome Integr 2006. [DOI: 10.1007/7050_013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
29
|
Macé G, Bogliolo M, Guervilly JH, Dugas du Villard JA, Rosselli F. 3R coordination by Fanconi anemia proteins. Biochimie 2005; 87:647-58. [PMID: 15935541 DOI: 10.1016/j.biochi.2005.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Fanconi anemia (FA) is a recessive cancer prone syndrome featuring bone marrow failure and hypersensitivity to DNA crosslinks. Nine FA genes have been isolated so far. The biochemical function(s) of the FA proteins remain(s) poorly determined. However, a large consensus exists on the evidence that, to cope with DNA cross-links, a cell needs a functional FA pathway. In this review, we resume current understanding of how the FA pathway works in response to DNA damage and how it is integrated in a complex network of proteins involved in the maintenance of the genetic stability.
Collapse
Affiliation(s)
- Gaëtane Macé
- Institut Gustave-Roussy PR2, UPR2169 du CNRS, 39, rue Camille-Desmoulins, 94805 Villejuif cedex, France
| | | | | | | | | |
Collapse
|
30
|
Habi O, Delisle MC, Messier N, Carreau M. Lack of self-renewal capacity in Fancc-/- stem cells after ex vivo expansion. Stem Cells 2005; 23:1135-41. [PMID: 16020692 DOI: 10.1634/stemcells.2004-0356] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Treatments of the hematological manifestation in Fanconi anemia (FA) are first supported by attempts to stimulate hematopoiesis with androgens or hematopoietic growth factors. However, the long-term curative treatment of the hematological manifestation in FA patients is bone marrow (BM) or cord blood stem cell transplantation. The success rate for BM transplantation is fairly high with HLA-matched sibling donors but is, unfortunately, low with HLA-matched unrelated donors. An alternative curative treatment for those patients with no sibling donors might be gene transfer into hematopoietic stem cells. Because FA patients have reduced numbers of stem/progenitor cells, ex vivo expansion of hematopoietic stem cells would be a crucial step in gene transfer protocols. Using the FA mouse model, Fancc-/-, we tested the ability of CD34- hematopoietic stem cells to support ex vivo expansion. We determined that Fancc-/- CD34- stem cells have reduced reconstitution ability and markedly reduced self-renewal ability after culture, as shown by secondary transplants. These results indicate that FA stem cells may not be well suited for ex vivo expansion before gene transfer or transplantation protocols.
Collapse
Affiliation(s)
- Ouassila Habi
- Human and Molecular Genetic Unit, CHUQ-Hôpital St-François d'Assise, 10 rue de l'Espinay, Quebec, QC, Canada G1L 3L5
| | | | | | | |
Collapse
|
31
|
Léveillé F, Blom E, Medhurst AL, Bier P, Laghmani EH, Johnson M, Rooimans MA, Sobeck A, Waisfisz Q, Arwert F, Patel KJ, Hoatlin ME, Joenje H, de Winter JP. The Fanconi anemia gene product FANCF is a flexible adaptor protein. J Biol Chem 2004; 279:39421-30. [PMID: 15262960 DOI: 10.1074/jbc.m407034200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Fanconi anemia (FA) protein FANCF is an essential component of a nuclear core complex that protects the genome against chromosomal instability, but the specific function of FANCF is still poorly understood. Based upon the homology between human and Xenopus laevis FANCF, we carried out an extensive mutagenesis study to examine which domains are functionally important and to gain more insight into the function of FANCF. In contrast to previous suggestions, we show that FANCF does not have a ROM-like function. We found that the C terminus of FANCF interacts directly with FANCG and allows the assembly of other FA proteins into a stable complex. The N terminus appears to stabilize the interaction with FANCA and FANCG and is essential for the binding of the FANCC/FANCE subcomplex. We identified several important amino acids in this N-terminal region but, surprisingly, many amino acid changes failed to affect the function of the FANCF protein. Our data demonstrate that FANCF acts as a flexible adaptor protein that plays a key role in the proper assembly of the FA core complex.
Collapse
Affiliation(s)
- France Léveillé
- Department of Clinical Genetics and Human Genetics, VU University Medical Center, Van der Boechorststraat 7, NL-1081BT Amsterdam, The Netherlands
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Pichierri P, Rosselli F. The DNA crosslink-induced S-phase checkpoint depends on ATR-CHK1 and ATR-NBS1-FANCD2 pathways. EMBO J 2004; 23:1178-87. [PMID: 14988723 PMCID: PMC380971 DOI: 10.1038/sj.emboj.7600113] [Citation(s) in RCA: 230] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2003] [Accepted: 01/12/2004] [Indexed: 02/07/2023] Open
Abstract
The genetic syndrome Fanconi anemia (FA) is characterized by aplastic anemia, cancer predisposition and hypersensitivity to DNA interstrand crosslinks (ICLs). FA proteins (FANCs) are thought to work in pathway(s) essential for dealing with crosslinked DNA. FANCs interact with other proteins involved in both DNA repair and S-phase checkpoint such as BRCA1, ATM and the RAD50/MRE11/NBS1 (RMN) complex. We deciphered the previously undefined pathway(s) leading to the ICLs-induced S-phase checkpoint and the role of FANCs in this process. We found that ICLs activate a branched pathway downstream of the ATR kinase: one branch depending on CHK1 activity and the other on the FANCs-RMN complex. The transient slow-down of DNA synthesis was abolished in cells lacking ATR, whereas CHK1-siRNA-treated cells, NBS1 or FA cells showed partial S-phase arrest. CHK1 RNAi in NBS1 or FA cells abolished the S-phase checkpoint, suggesting that CHK1 and FANCs/NBS1 proteins work on parallel pathways. Furthermore, we found that ICLs trigger ATR-dependent FANCD2 phosphorylation and FANCD2/ATR colocalization. This study demonstrates a novel relationship between the FA pathway(s) and the ATR kinase.
Collapse
Affiliation(s)
- Pietro Pichierri
- UPR 2169 du CNRS, Institut Gustave Roussy PR2, Villejuif Cedex, France
| | - Filippo Rosselli
- UPR 2169 du CNRS, Institut Gustave Roussy PR2, Villejuif Cedex, France
| |
Collapse
|
33
|
Brodeur I, Goulet I, Tremblay CS, Charbonneau C, Delisle MC, Godin C, Huard C, Khandjian EW, Buchwald M, Lévesque G, Carreau M. Regulation of the Fanconi Anemia Group C Protein through Proteolytic Modification. J Biol Chem 2004; 279:4713-20. [PMID: 14625294 DOI: 10.1074/jbc.m301291200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The function of the Fanconi anemia group C protein (FANCC) is still unknown, though many studies point to a role in damage response signaling. Unlike other known FA proteins, FANCC is mainly localized to the cytoplasm and is thought to act as a messenger of cellular damage rather than an effector of repair. FANCC has been shown to interact with several cytoplasmic and nuclear proteins and to delay the onset of apoptosis through redox regulation of GSTP1. We investigated the fate and function of FANCC during apoptosis. Here we show that FANCC undergoes proteolytic modification by a caspase into a predominant 47-kDa ubiquitinated protein fragment. Lack of proteolytic modification at the putative cleavage site delays apoptosis but does not affect MMC complementation. These results suggest that FANCC function is regulated through proteolytic processing.
Collapse
Affiliation(s)
- Isabelle Brodeur
- Unité de Génétique Humaine et Moléculaire, CHUQ-Pavillon St-François d'Assise, Quebec, Quebec G1L 3L5, Canada
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Abstract
Ubiquitination is a post-translational modification in which a small conserved peptide, ubiquitin, is appended to target proteins in the cell, through a series of complex enzymatic reactions. Recently, a particular form of ubiquitination, monoubiquitination, has emerged as a nonproteolytic reversible modification that controls protein function. In this review, we highlight recent findings on monoubiquitination as a signaling-induced modification, controlled, among others, by pathways originating from active receptor tyrosine kinases. Furthermore, we review the major cellular processes controlled by ubiquitin modification, including membrane trafficking, histone function, transcription regulation, DNA repair, and DNA replication.
Collapse
Affiliation(s)
- S Sigismund
- IFOM, The FIRC Institute for Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | | | | |
Collapse
|
35
|
Hölzel M, van Diest PJ, Bier P, Wallisch M, Hoatlin ME, Joenje H, de Winter JP. FANCD2 protein is expressed in proliferating cells of human tissues that are cancer-prone in Fanconi anaemia. J Pathol 2003; 201:198-203. [PMID: 14517836 DOI: 10.1002/path.1450] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Fanconi anaemia (FA) is an inherited form of progressive pancytopenia associated with developmental defects, chromosomal instability, and cancer predisposition. At least seven distinct FA proteins function in concert to protect the genome, a key step being the activation of FANCD2 by mono-ubiquitination. This paper reports an immunohistochemical analysis of FANCD2 expression in normal human tissue. The highest expression was observed in maturing spermatocytes and fetal oocytes (consistent with a role for FANCD2 in meiosis) and in germinal centre cells of the spleen, tonsil, and lymph nodes (consistent with a role in proliferation). FANCD2 expression was also seen in tissues predisposed to cancer development in FA patients: haematopoietic cells, especially in the fetus, and squamous cell epithelia, particularly in the head and neck region and uterine cervix. FANCD2 expression was also occasionally seen in the breast and Fallopian tube epithelium, the respiratory epithelium of the trachea, and the exocrine cells of the pancreas, indicating that these tissues may also be cancer-prone in FA. FANCD2 expression is frequently expressed in proliferating cells as demonstrated by Ki-67 immunofluorescence double staining, consistent with a function of FANCD2 in DNA replication.
Collapse
Affiliation(s)
- Michael Hölzel
- Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
36
|
Gordon SM, Buchwald M. Fanconi anemia protein complex: mapping protein interactions in the yeast 2- and 3-hybrid systems. Blood 2003; 102:136-41. [PMID: 12649160 DOI: 10.1182/blood-2002-11-3517] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Fanconi anemia (FA) is an autosomal recessive syndrome characterized by progressive bone marrow failure and cancer predisposition. Eight FA complementation groups have been identified. The FANCA, FANCC, FANCE, FANCF, and FANCG proteins form a nuclear complex required for the monoubiquination of the FANCD2 protein. To investigate the architecture of the FA protein complex, the yeast 2-hybrid system was used to map contact points of the FANCA/FANCG, FANCC/FANCE, and FANCF/FANCG interactions. FANCG was shown to interact with both the amino-terminus of FANCA and the carboxyl-terminal region of FANCF. A FANCG mutant truncated at the carboxyl-terminus retained the ability to interact with FANCA. The interaction between FANCG and FANCF was ablated by a Leu71Pro mutant of FANCG. A central region of FANCE was sufficient for FANCC binding. A Leu554Pro mutant of FANCC failed to interact with FANCE. To further examine complex assembly, the yeast 3-hybrid system was used to investigate the ability of FANCG to act as a molecular bridge in mediating interaction between other FA proteins. FANCG was able to mediate interaction between FANCA and FANCF, as well as between monomers of FANCA. Direct interaction between FANCE and FANCD2 was also demonstrated in the yeast 2-hybrid system. This interaction involving an amino-terminal region of FANCD2 may provide a link between the FA protein complex and its downstream targets.
Collapse
Affiliation(s)
- Susan M Gordon
- Program in Genetics and Genomic Biology, Research Institute, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.
| | | |
Collapse
|
37
|
Aubé M, Lafrance M, Brodeur I, Delisle MC, Carreau M. Fanconi anemia genes are highly expressed in primitive CD34+ hematopoietic cells. BMC BLOOD DISORDERS 2003; 3:1. [PMID: 12809565 PMCID: PMC194856 DOI: 10.1186/1471-2326-3-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2003] [Accepted: 06/16/2003] [Indexed: 11/10/2022]
Abstract
BACKGROUND: Fanconi anemia (FA) is a complex recessive genetic disease characterized by progressive bone marrow failure (BM) and a predisposition to cancer. We have previously shown using the Fancc mouse model that the progressive BM failure results from a hematopoietic stem cell defect suggesting that function of the FA genes may reside in primitive hematopoietic stem cells. METHODS: Since genes involved in stem cell differentiation and/or maintenance are usually regulated at the transcription level, we used a semiquantitative RT-PCR method to evaluate FA gene transcript levels in purified hematopoietic stem cells. RESULTS: We show that most FA genes are highly expressed in primitive CD34-positive and negative cells compared to lower levels in more differentiated cells. However, in CD34- stem cells the Fancc gene was found to be expressed at low levels while Fancg was undetectable in this population. Furthermore, Fancg expression is significantly decreased in Fancc -/- stem cells as compared to wild-type cells while the cancer susceptibility genes Brca1 and Fancd1/Brac2 are upregulated in Fancc-/- hematopoietic cells. CONCLUSIONS: These results suggest that FA genes are regulated at the mRNA level, that increased Fancc expression in LTS-CD34+ cells correlates with a role at the CD34+ differentiation stage and that lack of Fancc affects the expression of other FA gene, more specifically Fancg and Fancd1/Brca2, through an unknown mechanism.
Collapse
Affiliation(s)
- Michel Aubé
- Unité de génétique humaine et moléculaire, CHUQ-Hôpital St-François d'Assise, 10 rue de l'Espinay, Québec, Qc, Canada G1L 3L5
- Department of Pediatrics, Laval University, Québec, QC, Canada G1L 3L5
| | - Matthieu Lafrance
- Unité de génétique humaine et moléculaire, CHUQ-Hôpital St-François d'Assise, 10 rue de l'Espinay, Québec, Qc, Canada G1L 3L5
- Department of Pediatrics, Laval University, Québec, QC, Canada G1L 3L5
| | - Isabelle Brodeur
- Unité de génétique humaine et moléculaire, CHUQ-Hôpital St-François d'Assise, 10 rue de l'Espinay, Québec, Qc, Canada G1L 3L5
- Department of Pediatrics, Laval University, Québec, QC, Canada G1L 3L5
| | - Marie-Chantal Delisle
- Unité de génétique humaine et moléculaire, CHUQ-Hôpital St-François d'Assise, 10 rue de l'Espinay, Québec, Qc, Canada G1L 3L5
- Department of Pediatrics, Laval University, Québec, QC, Canada G1L 3L5
| | - Madeleine Carreau
- Unité de génétique humaine et moléculaire, CHUQ-Hôpital St-François d'Assise, 10 rue de l'Espinay, Québec, Qc, Canada G1L 3L5
- Department of Pediatrics, Laval University, Québec, QC, Canada G1L 3L5
| |
Collapse
|
38
|
Affiliation(s)
- Randy J Legerski
- Department of Molecular Genetics, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | | |
Collapse
|
39
|
Aubé M, Lafrance M, Charbonneau C, Goulet I, Carreau M. Hematopoietic stem cells from fancc(-/-) mice have lower growth and differentiation potential in response to growth factors. Stem Cells 2003; 20:438-47. [PMID: 12351814 DOI: 10.1634/stemcells.20-5-438] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Fanconi anemia (FA) is a complex recessive genetic disease characterized by progressive bone marrow (BM) failure. We have previously shown that stem cells from the FA group C mouse model have lower long-term primary and secondary reconstitution ability, and that bone marrow of Fancc(-/-) mice contained fewer lineage-negative (Lin(-))Thy1.2(low)Sca-1(+)c-kit(+) CD34(+) cells but normal levels of Lin(-)Thy1.2(low)Sca-1(+)c-kit(+)CD34(-) primitive cells. These data suggest that CD34(+) primitive cells have either a lower growth or differentiation potential, or that these cells have greater apoptosis levels. To investigate the role Fancc might have on the growth and differentiation potentials of primitive hematopoietic stem cells, we used a single-cell culture system and monitored cell viability, doubling potential, and apoptosis levels of Fancc(-/-) primitive Lin(-)Thy1.2(-)Sca-1(+) (LTS)-CD34(+) and LTS-CD34(-) stem cells. Results showed that Fancc(-/-) LTS-CD34(-) and LTS-CD34(+) cells had altered growth and apoptosis responses to combinations of stimulatory cytokines, most dramatically in response to a combination of factors that included interleukin-3 (IL-3) and IL-6. In addition, Fancc(-/-) LTS-CD34(-) and LTS-CD34(+) cells showed a lower differentiation potential than Fancc(+/+) cells. These results support a role for Fancc in the growth and differentiation of primitive hematopoietic cells and suggest that an altered response to stimulatory cytokines may contribute to BM aplasia in FA patients.
Collapse
Affiliation(s)
- Michel Aubé
- Unité de génétique humaine et moléculaire, CHUQ-Hôpital St-François d'Assise, Québec, Québec, Canada
| | | | | | | | | |
Collapse
|
40
|
Poot M, Yom JS, Whang SH, Kato JT, Gollahon KA, Rabinovitch PS. Werner syndrome cells are sensitive to DNA cross-linking drugs. FASEB J 2001; 15:1224-6. [PMID: 11344095 DOI: 10.1096/fj.00-0611fje] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- M Poot
- Department of Pathology, University of Washington, Seattle, Washington 98195-7705, USA.
| | | | | | | | | | | |
Collapse
|
41
|
Wajnrajch MP, Gertner JM, Huma Z, Popovic J, Lin K, Verlander PC, Batish SD, Giampietro PF, Davis JG, New MI, Auerbach AD. Evaluation of growth and hormonal status in patients referred to the International Fanconi Anemia Registry. Pediatrics 2001; 107:744-54. [PMID: 11335753 DOI: 10.1542/peds.107.4.744] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES 1) To determine the extent of short stature in patients with Fanconi anemia (FA); 2) to determine the extent and nature of endocrinopathy in FA; 3) to assess the impact on height of any endocrinopathies in these patients; and 4) to study the correlation, if any, between height, endocrinopathy, and FA complementation group. STUDY DESIGN Fifty-four patients with FA, 30 males and 24 females from 47 unrelated families, were prospectively evaluated in a Pediatric Clinical Research Center. The patients ranged in age from 0.1-31.9 years, with the mean age at assessment 8.6 years. RESULTS Endocrine abnormalities were found in 44 of the 54 FA patients tested (81%), including short stature, growth hormone (GH) insufficiency, hypothyroidism, glucose intolerance, hyperinsulinism, and/or overt diabetes mellitus. Twenty-one of 48 (44%) participants had a subnormal response to GH stimulation; 19 of 53 (36%) had overt or compensated hypothyroidism, while 8 of 40 participants had reduced thyroid-hormone binding. Two patients were diabetic at the time of study; impaired glucose tolerance was found in 8 of 40 patients (25%), but most surprisingly, hyperinsulinemia was present in 28 of 39 (72%) participants tested. Significantly, spontaneous overnight GH secretion was abnormal in all patients tested (n = 13). In addition, participants demonstrated a tendency toward primary hypothyroidism with serum tetraiodothyronine levels at the lower range of normal, while also having thyrotropin (thyroid-stimulating hormone) levels at the high end of normal. Sixteen patients were assigned to FA complementation group A, (FA-A), 12 to FA-C, and 5 to FA-G; 10 of the 12 participants in FA-C were homozygous for a mutation in the intron-4 donor splice site of the FANCC gene. Patients in groups FA-A and FA-G were relatively taller than the group as a whole (but still below the mean for the general population), whereas those in FA-C had a significantly reduced height for age. GH response to stimulation testing was most consistently normal in participants from FA-G, but this did not reach statistical significance. The tendency toward hypothyroidism was more pronounced in participants belonging to complementation groups FA-C and FA-G, whereas insulin resistance was most evident in patients in FA-G, and least evident in those in FA-C. Short stature was a very common finding among the patients with a mean height >2 standard deviations below the reference mean (standard deviation score: -2.35 +/- 0.28). Patients with subnormal GH response and those with overt or compensated hypothyroidism were shorter than the group with no endocrinopathies. The heights of those participants with glucose or insulin abnormalities were less severely affected than those of normoglycemic, normoinsulinemic participants, although all were significantly below the normal mean. The mean height standard deviation score of patients with entirely normal endocrine function was also >2 standard deviations below the normal mean, demonstrating that short stature is an inherent feature of FA. CONCLUSION Endocrinopathies are a common feature of FA, primarily manifesting as glucose/insulin abnormalities, GH insufficiency, and hypothyroidism. Although short stature is a well-recognized feature of FA, 23 patients (43%) were within 2 standard deviations, and 5 of these (9% of the total) were actually above the mean for height for the general population. Those patients with endocrine dysfunction are more likely to have short stature. These data indicate that short stature is an integral feature of FA, but that superimposed endocrinopathies further impact on growth. The demonstration of abnormal endogenous GH secretion may demonstrate an underlying hypothalamic-pituitary dysfunction that results in poor growth.
Collapse
Affiliation(s)
- M P Wajnrajch
- Department of Pediatrics and Children's Clinical Research Center, New York Presbyterian Hospital-Cornell University Medical Center, New York, New York 10021, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Sala-Trepat M, Rouillard D, Escarceller M, Laquerbe A, Moustacchi E, Papadopoulo D. Arrest of S-phase progression is impaired in Fanconi anemia cells. Exp Cell Res 2000; 260:208-15. [PMID: 11035915 DOI: 10.1006/excr.2000.4994] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fanconi anemia (FA) is an inherited cancer-susceptibility disorder, characterized by genomic instability, hypersensitivity to DNA cross-linking agents, and a prolonged G2 phase of the cell cycle. We observed a marked dose-dependent accumulation of FA cells in the G2 compartment after treatment with 4,5',8-trimethylpsoralen (Me(3)Pso) in combination with 365 nm irradiation. Using bivariate DNA distribution methodology, we determined the proportion of replicating and arresting S-phase cells and observed that, whereas normal cells arrested DNA replication in the presence of Me(3)Pso cross-links and monoadducts, FA lymphoblasts failed to arrest DNA synthesis. Taken together, the above data suggest that, in response to damage induced by DNA cross-linking agents, the S-phase checkpoint is inefficient in FA cells. This would lead to accumulation of secondary lesions, such as single- and double-strand breaks and gaps. The prolonged time in G2 phase seen in FA cells therefore exists in order to allow the cells to remove lesions which accumulated during the preceding abnormal S phase.
Collapse
|
43
|
Wong JC, Alon N, Norga K, Kruyt FA, Youssoufian H, Buchwald M. Cloning and analysis of the mouse Fanconi anemia group A cDNA and an overlapping penta zinc finger cDNA. Genomics 2000; 67:273-83. [PMID: 10936049 DOI: 10.1006/geno.2000.6252] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Despite the cloning of four disease-associated genes for Fanconi anemia (FA), the molecular pathogenesis of FA remains largely unknown. To study FA complementation group A using the mouse as a model system, we cloned and characterized the mouse homolog of the human FANCA cDNA. The mouse cDNA (Fanca) encodes a 161-kDa protein that shares 65% amino acid sequence identity with human FANCA. Fanca is located at the distal region of mouse chromosome 8 and has a ubiquitous pattern of expression in embryonic and adult tissues. Expression of the mouse cDNA in human FA-A cells restores the cellular drug sensitivity to normal levels. Thus, the expression pattern, protein structure, chromosomal location, and function of FANCA are conserved in the mouse. We also isolated a novel zinc finger protein, Zfp276, which has five C(2)H(2) domains. Interestingly, Zfp276 is situated in the Fanca locus, and the 3'UTR of its cDNA overlaps with the last four exons of Fanca in a tail-to-tail manner. Zfp276 is expressed in the same tissues as Fanca, but does not complement the mitomycin C (MMC)-sensitive phenotype of FA-A cells. The overlapping genomic organization between Zfp276 and Fanca may have relevance to the disease phenotype of FA.
Collapse
Affiliation(s)
- J C Wong
- Program in Genetics and Genomics Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
44
|
Abstract
Fanconi anemia is a polygenic trait hypothesized to be a DNA damage repair disease. We show that all three Fanconi anemia loci that have been cloned are expressed in the embryonic gonad during the period of primordial germ cell proliferation. Mice mutant for the Fanconi anemia complementation group C locus (Fancc) have reduced germ cell numbers as early as embryonic day E12.5, suggesting the Fancc protein functions prior to meiosis in both sexes. Depletion in the mutant occurs at a time when all three loci would be expressed in a wild-type gonad, implying a function in the early germline. Determination of the mitotic index of primordial germ cells by BrdU incorporation shows that germ cells in Fancc(-/-) mice proliferate significantly more slowly than littermate controls. This study demonstrates Fancc is required for mitotic proliferation of primordial germ cells.
Collapse
|
45
|
Vessey CJ, Norbury CJ, Hickson ID. Genetic disorders associated with cancer predisposition and genomic instability. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1999; 63:189-221. [PMID: 10506832 DOI: 10.1016/s0079-6603(08)60723-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Genomic instability in its broadest sense is a feature of virtually all neoplastic cells. In addition to the mutations and/or gene amplifications that appear to be a prerequisite for the acquisition of a neoplastic phenotype, human cancers exhibit other "markers" of genomic instability--in particular, a high degree of aneuploidy. Indeed, many studies have shown that aneuploidy is an almost invariant feature of cancer cells, and it has been argued by some that the emergence of aneuploid cells is a necessary step during tumorigenesis. The functional link between genomic instability and cancer is strengthened by the existence of several "genetic instability" disorders of humans that are associated with a moderate to severe increase in the incidence of cancers. These disorders include ataxia telangiectasia, Bloom's syndrome, Fanconi anemia, xeroderma pigmentosum, and Nijmegen breakage syndrome, all of which are very rare and are inherited in a recessive manner. Analysis of the cells from such cancer-prone individuals is clearly a potentially fruitful approach for delineating the genetic basis for instability in the genome. It is assumed that by identifying the underlying cause of genetic instability in these disorders, one can derive valuable information not only about the basis of particular genetic diseases, but also about the underlying causes of genomic instability in sporadic cancers in the general population. In this article, we review the clinical and cellular properties of genetic instability disorders associated with cancer predisposition. In particular, we focus on the rapid advances made in our understanding of these disorders that have derived from the cloning of the genes mutated in each case. Because in many instances the affected genes have analogs in lower eukaryotic species, we shall discuss how studies in yeasts in particular have proved valuable in our understanding of human diseases and predisposition to cancer.
Collapse
Affiliation(s)
- C J Vessey
- Imperial Cancer Research Fund Laboratories, University of Oxford, John Radcliffe Hospital, United Kingdom
| | | | | |
Collapse
|
46
|
Smith J, Andrau JC, Kallenbach S, Laquerbe A, Doyen N, Papadopoulo D. Abnormal rearrangements associated with V(D)J recombination in Fanconi anemia. J Mol Biol 1998; 281:815-25. [PMID: 9719637 DOI: 10.1006/jmbi.1998.1971] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The hallmark of Fanconi anemia (FA), a rare inherited cancer prone disorder, is a high level of chromosome breakage, spontaneous and induced by cross-linking agents. The increased genomic instability of FA is reflected at the gene level by an overproduction of intragenic deletions. Two of the eight FA genes have been cloned, however, their function remains unknown. We recently demonstrated that the lack of functional FA genes lead to a marked decrease in the fidelity of non-homologous end-joining, a pathway that mammalian cells predominantly use to repair DNA double-strand breaks (DSB). Knowing that specific DSB are generated during V(D)J recombination, here we have examined the molecular features of V(D)J rearrangements in normal and FA lymphoblasts belonging to complementation groups C and D. Using appropriate extrachromosomal recombination substrates, V(D)J coding and signal joint formation have been analysed quantitatively and qualitatively. Our results show that the frequency of coding and signal joint formation was not significantly different in normal and FA cells. However, when the fidelity of the V(D)J reaction was examined, we found that in normal human lymphoblasts V(D)J recombination proceeds with high precision, whereas, in FA cells a several fold increase in the frequency of aberrant rearrangements is associated with V(D)J coding joint formation. The abnormal recombinants that we recovered in FA are consistent with excessive degradation of DNA ends generated during the V(D)J reaction. On the basis of these findings, we propose a working model in which FA genes play a role in the control of the fidelity of rejoining of specific DNA ends. Such a defect may explain several basic features of FA, such as chromosomal instability and deletion proneness.
Collapse
Affiliation(s)
- J Smith
- UMR 218 CNRS, LRC n degrees1 CEA, Institut Curie-Recherche, 26 rue d'Ulm, Paris Cedex 05, 75248, France
| | | | | | | | | | | |
Collapse
|
47
|
Abstract
Some genes that contain premature nonsense codons express alternatively-spliced mRNA that has skipped the exon containing the nonsense codon. This paradoxical association of translation signals (nonsense codons) and RNA splicing has inspired numerous explanations. The first is based on the fact that premature nonsense codons often reduce mRNA abundance. The reduction in abundance of full-length mRNA then allows more efficient amplification during PCR of normal, minor, exon-deleted products. This mechanism has been demonstrated to explain an extensive correlation between nonsense codons and exon-skipping for the hamster Hprt gene. The second explanation is that the mutation producing an in-frame nonsense codon has an effect on exon definition. This has been demonstrated for the Mup and hamster Hprt gene by virtue of the fact that missense mutations at the same sites also are associated with the same exon-deleted mRNA. The third general explanation is that a hypothetical process takes place in the nucleus that recognizes nonsense codons, termed 'nuclear scanning', which then has an effect on mRNA splicing. Definitive evidence for nuclear scanning is lacking. My analysis of both nonsense and missense mutations associated with exon skipping in a large number of genes revealed that both types of mutations frequently introduce a T into a purine-rich DNA sequence and are often within 30 base pairs of the nearest exon boundary. This is intriguing given that purine-rich splicing enhancers are known to be inhibited by the introduction of a T. Almost all mutations associated with exon skipping occur in purine-rich or A/C-rich sequences, also characteristics of splicing enhancers. I conclude that most cases of exon skipping associated with premature termination codons may be adequately explained either by a structural effect on exon definition or by nonquantitative methods to measure mRNA, rather than an effect on a putative nuclear scanning mechanism.
Collapse
Affiliation(s)
- C R Valentine
- Division of Genetic and Reproductive Toxicology, National Center for Toxicological Research, Jefferson, AR 72079-9502, USA.
| |
Collapse
|
48
|
Escarceller M, Buchwald M, Singleton BK, Jeggo PA, Jackson SP, Moustacchi E, Papadopoulo D. Fanconi anemia C gene product plays a role in the fidelity of blunt DNA end-joining. J Mol Biol 1998; 279:375-85. [PMID: 9642044 DOI: 10.1006/jmbi.1998.1784] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mutations in genes controlling the correct functioning of the replicative, repair and recombination machineries may lead to genomic instability. A high level of spontaneous chromosomal aberrations amplified by treatment with DNA cross-linking agents is the hallmark of Fanconi anemia (FA), an inherited chromosomal instability syndrome associated with cancer proneness. Two of the eight FA genes have been cloned (FAA and FAC), but their function has not yet been defined. The lack of homology with known genes suggests the involvement of FA genes in a novel pathway specific to vertebrates. Using a DNA end-joining assay in cultured cells, we studied the processing of both blunt and cohesive-ended double strand breaks (DSB) in normal and FA cells. The results show that: (i) the overall ligation efficiency is normal in FA lymphoblasts; (ii) in FA-C, error-free processing of blunt-ended DSB is markedly decreased, resulting in a higher deletion frequency and larger deletion size; (iii) the fidelity of processing of blunt-DSB is completely restored in FACC cells (complemented with wild-type FAC gene) and the deletion size shifted to values similar to that observed in normal cells; (iv) the fidelity of cohesive end-joining is not affected in FA cells; (v) activities and/or expression of known factors involved in DSB processing, such as the components of the DNA-PK complex and XRCC4, are normal in FA cells. Our results provide strong evidence that the lack of a functional FAC gene results in loss of fidelity of end-joining, which likely accounts for the FA-C phenotype of chromosome instability. We conclude that FAC, and perhaps all FA gene products, are likely to play a role in the fidelity of end-joining of specific DSB.
Collapse
Affiliation(s)
- M Escarceller
- UMR 218 CNRS LRC n(o)1 du CEA, Institut Curie-Recherche, Paris, France
| | | | | | | | | | | | | |
Collapse
|
49
|
Abstract
Fanconi anemia (FA) is a pleiotropic inherited disease that causes bone marrow failure in children. However, the specific involvement of FA genes in hematopoiesis and their relation to bone marrow (BM) failure is still unclear. The increased sensitivity of FA cells to DNA cross-linking agents such as mitomycin C (MMC) and diepoxybutane (DEB), including the induction of chromosomal aberrations and delay in the G2 phase of the cell cycle, have suggested a role for the FA genes in DNA repair, cell cycle regulation, and apoptosis. We previously reported the cloning of the FA group C gene (FAC) and the generation of a Fac mouse model. Surprisingly, the Fac −/− mice did not show any of the hematologic defects found in FA patients. To better understand the relationship of FA gene functions to BM failure, we have analyzed the in vivo effect of an FA-specific DNA damaging agent in Fac −/− mice. The mice were found to be highly sensitive to DNA cross-linking agents; acute exposure to MMC produced a marked BM hypoplasia and degeneration of proliferative tissues and caused death within a few days of treatment. However, sequential, nonlethal doses of MMC caused a progressive decrease in all peripheral blood parameters of Fac −/− mice. This treatment targeted specifically the BM compartment, with no effect on other proliferative tissues. The progressive pancytopenia resulted from a reduction in the number of early and committed hematopoietic progenitors. These results indicate that the FA genes are involved in the physiologic response of hematopoietic progenitor cells to DNA damage.
Collapse
|
50
|
Escarceller M, Rousset S, Moustacchi E, Papadopoulo D. The fidelity of double strand breaks processing is impaired in complementation groups B and D of Fanconi anemia, a genetic instability syndrome. SOMATIC CELL AND MOLECULAR GENETICS 1997; 23:401-11. [PMID: 9661703 DOI: 10.1007/bf02673750] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In mammalian cells, nonhomologous end-joining is the predominant mechanism to eliminate DNA double strand breaks. Such events are at the origin of deletion mutagenesis and chromosomal rearrangements. The hallmark of Fanconi anemia, an inherited cancer prone disorder, is increased chromosomal breakage associated to over-production of deletions. Knowing that double strand breaks are at the origin of deletion mutagenesis, the question arises whether their processing is affected in FA. We set up a "host cell end-joining assay" to analyze the fate of double strand breaks into extrachromosomal substrates transiently replicated in normal and FA-D lymphoblasts. Although no difference in plasmid survival was found, blunt-ended breaks were sealed with significantly lower fidelity in FA cells, resulting in a higher deletion frequency and a larger deletion size. The results suggest that FA-D and FA-B gene products are likely to play a role in end-joining fidelity of specific DNA double strand breaks.
Collapse
Affiliation(s)
- M Escarceller
- UMR 218 CNRS, LRC n(0) 1 du CEA, Institut Curie-Recherche, Paris, France
| | | | | | | |
Collapse
|