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Sample records for fanconi anemia complementation

  1. Identification of the Fanconi anemia complementation group I gene, FANCI.

    PubMed

    Dorsman, Josephine C; Levitus, Marieke; Rockx, Davy; Rooimans, Martin A; Oostra, Anneke B; Haitjema, Anneke; Bakker, Sietske T; Steltenpool, Jûrgen; Schuler, Dezsö; Mohan, Sheila; Schindler, Detlev; Arwert, Fré; Pals, Gerard; Mathew, Christopher G; Waisfisz, Quinten; de Winter, Johan P; Joenje, Hans

    2007-01-01

    To identify the gene underlying Fanconi anemia (FA) complementation group I we studied informative FA-I families by a genome-wide linkage analysis, which resulted in 4 candidate regions together encompassing 351 genes. Candidates were selected via bioinformatics and data mining on the basis of their resemblance to other FA genes/proteins acting in the FA pathway, such as: degree of evolutionary conservation, presence of nuclear localization signals and pattern of tissue-dependent expression. We found a candidate, KIAA1794 on chromosome 15q25-26, to be mutated in 8 affected individuals previously assigned to complementation group I. Western blots of endogenous FANCI indicated that functionally active KIAA1794 protein is lacking in FA-I individuals. Knock-down of KIAA1794 expression by siRNA in HeLa cells caused excessive chromosomal breakage induced by mitomycin C, a hallmark of FA cells. Furthermore, phenotypic reversion of a patient-derived cell line was associated with a secondary genetic alteration at the KIAA1794 locus. These data add up to two conclusions. First, KIAA1794 is a FA gene. Second, this gene is identical to FANCI, since the patient cell lines found mutated in this study included the reference cell line for group I, EUFA592.

  2. Fanconi Anemia Research Fund

    MedlinePlus

    ... Support Publications Fundraising News What is the Fanconi Anemia Research Fund? Fanconi anemia is an inherited disease that can lead to ... population. Lynn and Dave Frohnmayer started the Fanconi Anemia Research Fund, in 1989 to find effective treatments ...

  3. Fanconi anemia complementation group FANCD2 protein serine 331 phosphorylation is important for fanconi anemia pathway function and BRCA2 interaction.

    PubMed

    Zhi, Gang; Wilson, James B; Chen, Xiaoyong; Krause, Diane S; Xiao, Yuxuan; Jones, Nigel J; Kupfer, Gary M

    2009-11-15

    Fanconi anemia is a cancer-prone inherited bone marrow failure and cancer susceptibility syndrome with at least 13 complementation groups (FANCA, FANCB, FANCC, FANCD1, FANCD2, FANCE, FANCF, FANCG, FANCI, FANCJ, FANCL, FANCM, and FANCN). Our laboratory has previously described several regulatory phosphorylation events for core complex member proteins FANCG and FANCA by phosphorylation. In this study, we report a novel phosphorylation site serine 331 (S331) of FANCD2, the pivotal downstream player of the Fanconi anemia pathway. Phosphorylation of S331 is important for its DNA damage-inducible monoubiquitylation, resistance to DNA cross-linkers, and in vivo interaction with FANCD1/BRCA2. A phosphomimetic mutation at S331 restores all of these phenotypes to wild-type. In vitro and in vivo experiments show that phosphorylation of S331 is mediated by CHK1, the S-phase checkpoint kinase implicated in the Fanconi anemia DNA repair pathway.

  4. A human ortholog of archaeal DNA repair protein Hef is defective in Fanconi anemia complementation group M.

    PubMed

    Meetei, Amom Ruhikanta; Medhurst, Annette L; Ling, Chen; Xue, Yutong; Singh, Thiyam Ramsing; Bier, Patrick; Steltenpool, Jurgen; Stone, Stacie; Dokal, Inderjeet; Mathew, Christopher G; Hoatlin, Maureen; Joenje, Hans; de Winter, Johan P; Wang, Weidong

    2005-09-01

    Fanconi anemia is a genetic disease characterized by genomic instability and cancer predisposition. Nine genes involved in Fanconi anemia have been identified; their products participate in a DNA damage-response network involving BRCA1 and BRCA2 (refs. 2,3). We previously purified a Fanconi anemia core complex containing the FANCL ubiquitin ligase and six other Fanconi anemia-associated proteins. Each protein in this complex is essential for monoubiquitination of FANCD2, a key reaction in the Fanconi anemia DNA damage-response pathway. Here we show that another component of this complex, FAAP250, is mutant in individuals with Fanconi anemia of a new complementation group (FA-M). FAAP250 or FANCM has sequence similarity to known DNA-repair proteins, including archaeal Hef, yeast MPH1 and human ERCC4 or XPF. FANCM can dissociate DNA triplex, possibly owing to its ability to translocate on duplex DNA. FANCM is essential for monoubiquitination of FANCD2 and becomes hyperphosphorylated in response to DNA damage. Our data suggest an evolutionary link between Fanconi anemia-associated proteins and DNA repair; FANCM may act as an engine that translocates the Fanconi anemia core complex along DNA.

  5. Living with Fanconi Anemia

    MedlinePlus

    ... from the NHLBI on Twitter. Living With Fanconi Anemia Improvements in blood and marrow stem cell transplants ... November 1, 2011 Twitter Facebook YouTube Google+ SITE INDEX ACCESSIBILITY PRIVACY STATEMENT FOIA NO FEAR ACT OIG ...

  6. Fanconi anemia: current management.

    PubMed

    Kook, Hoon

    2005-01-01

    Fanconi anemia (FA) is an autosomal recessive chromosomal instability disorder, characterized by congenital anomalies, defective hematopoiesis and a high risk of developing acute myeloid leukemia and certain solid tumors. All racial and ethnic groups are at risk, and at least 11 complementation groups have been identified and the genes defective in eight of these have been identified (FANCA, C, D2, E, F, G, L and BRCA2). FA-A is the most common complementation group, accounting for approximately 65% of all affected individuals. The gold-standard screening test for FA is based on the characteristic hypersensitivity of FA cells to the crosslinking agents, such as mitomicin C or diepoxybutane. Recent progress has been made in identifying the genes bearing pathogenetically relevant mutations, but slower progress has been made in defining the precise functions of the proteins in normal cells, in part because that the proteins are multifunctional. Molecular studies have established that a common pathway exist, both between the FA proteins and other proteins involved in DNA repair such as NBS1, ATM, BRCA1 and BRCA2. Stem cell transplantation (SCT) is the only option for establishing normal hematopoiesis. To reduce undue toxicities due to inherent hypersensitivity, nonmyeloablative conditioning for transplants has been advocated. This review summarizes the general clinical and hematologic features and the current management of FA. Fanconi anemia (FA) is the commonest type of inherited bone marrow failure syndrome with the birth incidence of around three per million. The inheritance pattern is autosomal recessive with the estimated heterozygote frequency being one in 300 in Europe and the US.

  7. Complementation of a Fanconi anemia group A cell line by UbA{sup 52}

    SciTech Connect

    Moses, R.E.; Heina, J.A.; Jakobs, P.M.

    1994-09-01

    Cells from patients with Fanconi anemia (FA) display chromosomal instability and increased sensitivity to mitomycin C (MMC) and diepoxybutane (DEB) relative to normal cells. Several genes act in this pathway of DNA damage processing based upon four known complementation groups in FA. We have made a cDNA expression library in a vector with a G418 selectable marker to identify FA genes other than the FA-C group. Approximately 1 x 10{sup 6} independent cDNA clones were isolated with an average cDNA size of 1.5 kb. Five cell lines resistant to MMC and DEB were isolated from 6 x 10{sup 6} G418-resistant transfectants from 65 individual transfections of the FA-A fibroblast line GM6914. The isolated cell lines also showed normal chromosome stability. The same cDNA (600 bp) was recovered from three independent cell lines by PCR using flanking sequence primers. The gene has sequence identity with a known gene, the ubiquitin fusion gene, UbA{sub 52}. Interestingly, each of the cDNAs were inserted in antisense orientation relative to the cytomegalovirus (CMV) promoter as determined by sequencing and PCR using UbA{sub 52}-specific internal primers. Southern blot analysis indicated the cell lines had distinct chromosomal insertion sites. Mutation analysis by chemical cleavage showed no reading frame mutations, indicating that UbA{sub 52} is not the FA-A gene. Re-transfection with the UbA{sub 52} gene in antisense gave complementation for MMC, DEB and chromosome stability to varying degrees. Re-transfection of the antisense construct with the CMV promotor removed or with a sense construct did not alter the MMC sensitivity. We conclude that the antisense UbA{sub 52} gene has a non-specific effect, perhaps acting by altering the cell cycle or susceptibility to apoptosis.

  8. Fanconi anemia complementation group A cells are hypersensitive to chromium(VI)-induced toxicity.

    PubMed Central

    Vilcheck, Susan K; O'Brien, Travis J; Pritchard, Daryl E; Ha, Linan; Ceryak, Susan; Fornsaglio, Jamie L; Patierno, Steven R

    2002-01-01

    Fanconi anemia (FA) is an autosomal recessive disorder characterized by diverse developmental abnormalities, progressive bone marrow failure, and a markedly increased incidence of malignancy. FA cells are hypersensitive to DNA cross-linking agents, suggesting a general defect in the repair of DNA cross-links. Some forms of hexavalent chromium [Cr(VI)] are implicated as respiratory carcinogens and induce several types of DNA lesions, including ternary DNA-Cr-DNA interstrand cross-links (Cr-DDC). We hypothesized that human FA complementation group A (FA-A) cells would be hypersensitive to Cr(VI) and Cr(VI)-induced apoptosis. Using phosphatidylserine translocation and caspase-3 activation, human FA-A fibroblasts were found to be markedly hypersensitive to chromium-induced apoptosis compared with CRL-1634 cells, which are normal human foreskin fibroblasts (CRL). The clonogenicity of FA-A cells was also significantly decreased compared with CRL cells after Cr(VI) treatment. There was no significant difference in either Cr(VI) uptake or Cr-DNA adduct formation between FA-A and CRL cells. These results show that FA-A cells are hypersensitive to Cr(VI) and Cr-induced apoptosis and that this hypersensitivity is not due to increased Cr(VI) uptake or increased Cr-DNA adduct formation. The results also suggest that Cr-DDC may be proapoptotic lesions. These results are the first to show that FA cells are hypersensitive to an environmentally relevant DNA cross-linking agent. PMID:12426130

  9. The Simple Chordate Ciona intestinalis Has a Reduced Complement of Genes Associated with Fanconi Anemia.

    PubMed

    Stanley, Edward C; Azzinaro, Paul A; Vierra, David A; Howlett, Niall G; Irvine, Steven Q

    2016-01-01

    Fanconi anemia (FA) is a human genetic disease characterized by congenital defects, bone marrow failure, and increased cancer risk. FA is associated with mutation in one of 24 genes. The protein products of these genes function cooperatively in the FA pathway to orchestrate the repair of DNA interstrand cross-links. Few model organisms exist for the study of FA. Seeking a model organism with a simpler version of the FA pathway, we searched the genome of the simple chordate Ciona intestinalis for homologs of the human FA-associated proteins. BLAST searches, sequence alignments, hydropathy comparisons, maximum likelihood phylogenetic analysis, and structural modeling were used to infer the likelihood of homology between C. intestinalis and human FA proteins. Our analysis indicates that C. intestinalis indeed has a simpler and potentially functional FA pathway. The C. intestinalis genome was searched for candidates for homology to 24 human FA and FA-associated proteins. Support was found for the existence of homologs for 13 of these 24 human genes in C. intestinalis. Members of each of the three commonly recognized FA gene functional groups were found. In group I, we identified homologs of FANCE, FANCL, FANCM, and UBE2T/FANCT. Both members of group II, FANCD2 and FANCI, have homologs in C. intestinalis. In group III, we found evidence for homologs of FANCJ, FANCO, FANCQ/ERCC4, FANCR/RAD51, and FANCS/BRCA1, as well as the FA-associated proteins ERCC1 and FAN1. Evidence was very weak for the existence of homologs in C. intestinalis for any other recognized FA genes. This work supports the notion that C. intestinalis, as a close relative of vertebrates, but having a much reduced complement of FA genes, offers a means of studying the function of certain FA proteins in a simpler pathway than that of vertebrate cells.

  10. The Simple Chordate Ciona intestinalis Has a Reduced Complement of Genes Associated with Fanconi Anemia

    PubMed Central

    Stanley, Edward C.; Azzinaro, Paul A.; Vierra, David A.; Howlett, Niall G.; Irvine, Steven Q.

    2016-01-01

    Fanconi anemia (FA) is a human genetic disease characterized by congenital defects, bone marrow failure, and increased cancer risk. FA is associated with mutation in one of 24 genes. The protein products of these genes function cooperatively in the FA pathway to orchestrate the repair of DNA interstrand cross-links. Few model organisms exist for the study of FA. Seeking a model organism with a simpler version of the FA pathway, we searched the genome of the simple chordate Ciona intestinalis for homologs of the human FA-associated proteins. BLAST searches, sequence alignments, hydropathy comparisons, maximum likelihood phylogenetic analysis, and structural modeling were used to infer the likelihood of homology between C. intestinalis and human FA proteins. Our analysis indicates that C. intestinalis indeed has a simpler and potentially functional FA pathway. The C. intestinalis genome was searched for candidates for homology to 24 human FA and FA-associated proteins. Support was found for the existence of homologs for 13 of these 24 human genes in C. intestinalis. Members of each of the three commonly recognized FA gene functional groups were found. In group I, we identified homologs of FANCE, FANCL, FANCM, and UBE2T/FANCT. Both members of group II, FANCD2 and FANCI, have homologs in C. intestinalis. In group III, we found evidence for homologs of FANCJ, FANCO, FANCQ/ERCC4, FANCR/RAD51, and FANCS/BRCA1, as well as the FA-associated proteins ERCC1 and FAN1. Evidence was very weak for the existence of homologs in C. intestinalis for any other recognized FA genes. This work supports the notion that C. intestinalis, as a close relative of vertebrates, but having a much reduced complement of FA genes, offers a means of studying the function of certain FA proteins in a simpler pathway than that of vertebrate cells. PMID:27279728

  11. How Is Fanconi Anemia Treated?

    MedlinePlus

    ... from the NHLBI on Twitter. How Is Fanconi Anemia Treated? Doctors decide how to treat Fanconi anemia (FA) based on a person's age and how ... Long-term treatments for FA can: Cure the anemia. Damaged bone marrow cells are replaced with healthy ...

  12. Impaired FANCD2 monoubiquitination and hypersensitivity to camptothecin uniquely characterize Fanconi anemia complementation group M.

    PubMed

    Singh, Thiyam Ramsing; Bakker, Sietske T; Agarwal, Sheba; Jansen, Michael; Grassman, Elke; Godthelp, Barbara C; Ali, Abdullah Mahmood; Du, Chang-hu; Rooimans, Martin A; Fan, Qiang; Wahengbam, Kebola; Steltenpool, Jurgen; Andreassen, Paul R; Williams, David A; Joenje, Hans; de Winter, Johan P; Meetei, Amom Ruhikanta

    2009-07-02

    FANCM is a component of the Fanconi anemia (FA) core complex and one FA patient (EUFA867) with biallelic mutations in FANCM has been described. Strikingly, we found that EUFA867 also carries biallelic mutations in FANCA. After correcting the FANCA defect in EUFA867 lymphoblasts, a "clean" FA-M cell line was generated. These cells were hypersensitive to mitomycin C, but unlike cells defective in other core complex members, FANCM(-/-) cells were proficient in monoubiquitinating FANCD2 and were sensitive to the topoisomerase inhibitor camptothecin, a feature shared only with the FA subtype D1 and N. In addition, FANCM(-/-) cells were sensitive to UV light. FANCM and a C-terminal deletion mutant rescued the cross-linker sensitivity of FANCM(-/-) cells, whereas a FANCM ATPase mutant did not. Because both mutants restored the formation of FANCD2 foci, we conclude that FANCM functions in an FA core complex-dependent and -independent manner.

  13. Epithelial cancer in Fanconi anemia complementation group D2 (Fancd2) knockout mice.

    PubMed

    Houghtaling, Scott; Timmers, Cynthia; Noll, Meenakshi; Finegold, Milton J; Jones, Stephen N; Meyn, M Stephen; Grompe, Markus

    2003-08-15

    Fanconi anemia (FA) is a genetic disorder characterized by hypersensitivity to DNA damage, bone marrow failure, congenital defects, and cancer. To further investigate the in vivo function of the FA pathway, mice with a targeted deletion in the distally acting FA gene Fancd2 were created. Similar to human FA patients and other FA mouse models, Fancd2 mutant mice exhibited cellular sensitivity to DNA interstrand cross-links and germ cell loss. In addition, chromosome mispairing was seen in male meiosis. However, Fancd2 mutant mice also displayed phenotypes not observed in other mice with disruptions of proximal FA genes. These include microphthalmia, perinatal lethality, and epithelial cancers, similar to mice with Brca2/Fancd1 hypomorphic mutations. These additional phenotypes were not caused by defects in the ATM-mediated S-phase checkpoint, which was intact in primary Fancd2 mutant fibroblasts. The phenotypic overlap between Fancd2-null and Brca2/Fancd1 hypomorphic mice is consistent with a common function for both proteins in the same pathway, regulating genomic stability.

  14. Homozygosity mapping of Fanconi anemia

    SciTech Connect

    Gschwend, M.; Botstein, D.; Kruglyak, L.

    1994-09-01

    Fanconi anemia (FA) is a rare, recessive, genetically heterogeneous disease characterized by progressive insufficiency of the bone marrow and increased cellular sensitivity to DNA crosslinking agents. Complementation tests among different FA cells have indicated the presence of at least 4 FA-causing genes. One of the genes, FACC, was identified by functional complementation but appears unlikely to account for many phenotypically indistinguishable FA caes. We have begun a linkage study of FA using {open_quotes}homozygosity mapping{close_quotes}, a method that involves genotyping with DNA markers on affected individuals whose parents are related. Because FA is a rare recessive disease, it is most likely that probands are homozygous by descent at the disease locus and, therefore, at nearby DNA markers. Although the probability that any given marker will be homozygous in an inbred individual is high, given markers with moderate heterozygosities, the chance that two unrelated inbred individuals will be homozygous at the same marker is considerably lower. By locating overlapping regions of homozygosity between different families we hope to identify genes that cause FA. Sixteen consanguineous non-FACC FA families from the International Fanconi Anemia Registry at Rockefeller University are under study. An efficient algorithm for data analysis was developed and incorporated into software that can quickly compute exact multipoint lod scores using all markers on an entire chromosome. At the time of this writing, 171 of 229 microsatellite markers spaced at 20 cM intervals across the genome have been analyzed.

  15. Advances in the understanding of Fanconi Anemia Complementation Group D2 Protein (FANCD2) in human cancer.

    PubMed

    Shen, Yihang; Zhang, Jun; Yu, Herbert; Fei, Peiwen

    Fanconi anemia (FA) is a rare human genetic disease, resulting from dysfunction in any of 17 known complementation proteins: FANC-A, B, C, D1, D2, E, F, G, I, J, L, M, N, O, P, Q & S, and other unknowns. Besides the severe bone marrow failure, an extremely high incidence of cancer as well as many other clinic symptoms associated with FA patients, FA cells are known of insufficiency in homologous recombination, DNA mismatch repair, nucleotide excision repair, translesion DNA synthesis, and other molecular defects, leading to genome instability. Those similar molecular and cellular/tissue features show that all FA proteins function in one common signaling pathway, namely, the FA pathway. The monoubiquitination of FANCD2 is the central step of the FA pathway activation upon DNA damage or during DNA replication. The molecular functions of FANCD2 emerge as a very attractive filed of investigation in cancer research. Herein, we review the recent progresses in FANCD2 functions at these rapidly progressed aspects.

  16. A novel ubiquitin ligase is deficient in Fanconi anemia.

    PubMed

    Meetei, Amom Ruhikanta; de Winter, Johan P; Medhurst, Annette L; Wallisch, Michael; Waisfisz, Quinten; van de Vrugt, Henri J; Oostra, Anneke B; Yan, Zhijiang; Ling, Chen; Bishop, Colin E; Hoatlin, Maureen E; Joenje, Hans; Wang, Weidong

    2003-10-01

    Fanconi anemia is a recessively inherited disease characterized by congenital defects, bone marrow failure and cancer susceptibility. Cells from individuals with Fanconi anemia are highly sensitive to DNA-crosslinking drugs, such as mitomycin C (MMC). Fanconi anemia proteins function in a DNA damage response pathway involving breast cancer susceptibility gene products, BRCA1 and BRCA2 (refs. 1,2). A key step in this pathway is monoubiquitination of FANCD2, resulting in the redistribution of FANCD2 to nuclear foci containing BRCA1 (ref. 3). The underlying mechanism is unclear because the five Fanconi anemia proteins known to be required for this ubiquitination have no recognizable ubiquitin ligase motifs. Here we report a new component of a Fanconi anemia protein complex, called PHF9, which possesses E3 ubiquitin ligase activity in vitro and is essential for FANCD2 monoubiquitination in vivo. Because PHF9 is defective in a cell line derived from an individual with Fanconi anemia, we conclude that PHF9 (also called FANCL) represents a novel Fanconi anemia complementation group (FA-L). Our data suggest that PHF9 has a crucial role in the Fanconi anemia pathway as the likely catalytic subunit required for monoubiquitination of FANCD2.

  17. Cytokine overproduction and crosslinker hypersensitivity are unlinked in Fanconi anemia macrophages.

    PubMed

    Garbati, Michael R; Hays, Laura E; Rathbun, R Keaney; Jillette, Nathaniel; Chin, Kathy; Al-Dhalimy, Muhsen; Agarwal, Anupriya; Newell, Amy E Hanlon; Olson, Susan B; Bagby, Grover C

    2016-03-01

    The Fanconi anemia proteins participate in a canonical pathway that repairs cross-linking agent-induced DNA damage. Cells with inactivated Fanconi anemia genes are universally hypersensitive to such agents. Fanconi anemia-deficient hematopoietic stem cells are also hypersensitive to inflammatory cytokines, and, as importantly, Fanconi anemia macrophages overproduce such cytokines in response to TLR4 and TLR7/8 agonists. We questioned whether TLR-induced DNA damage is the primary cause of aberrantly regulated cytokine production in Fanconi anemia macrophages by quantifying TLR agonist-induced TNF-α production, DNA strand breaks, crosslinker-induced chromosomal breakage, and Fanconi anemia core complex function in Fanconi anemia complementation group C-deficient human and murine macrophages. Although both M1 and M2 polarized Fanconi anemia cells were predictably hypersensitive to mitomycin C, only M1 macrophages overproduced TNF-α in response to TLR-activating signals. DNA damaging agents alone did not induce TNF-α production in the absence of TLR agonists in wild-type or Fanconi anemia macrophages, and mitomycin C did not enhance TLR responses in either normal or Fanconi anemia cells. TLR4 and TLR7/8 activation induced cytokine overproduction in Fanconi anemia macrophages. Also, although TLR4 activation was associated with induced double strand breaks, TLR7/8 activation was not. That DNA strand breaks and chromosome breaks are neither necessary nor sufficient to account for the overproduction of inflammatory cytokines by Fanconi anemia cells suggests that noncanonical anti-inflammatory functions of Fanconi anemia complementation group C contribute to the aberrant macrophage phenotype and suggests that suppression of macrophage/TLR hyperreactivity might prevent cytokine-induced stem cell attrition in Fanconi anemia.

  18. Fanconi Anemia and its Diagnosis

    PubMed Central

    Auerbach, Arleen D.

    2009-01-01

    Fanconi anemia (FA) is a genetically and phenotypically heterogeneous recessive disorder characterized by diverse congenital malformations, progressive pancytopenia, and predisposition to both hematologic malignancies and solid tumors. Congenital anomalies vary from patient to patient and may affect skeletal morphogenesis as well as any of the major organ systems. Although this highly variable phenotype makes accurate diagnosis on the basis of clinical manifestations difficult in some patients, laboratory study of chromosomal breakage induced by diepoxybutane (DEB) or other crosslinking agents provides a unique cellular marker for the diagnosis of the disorder either prenatally or postnatally. Diagnosis based on abnormal response to DNA crosslinking agents can be used to identify the pre-anemia patient as well as patients with aplastic anemia or leukemia who may or may not have the physical stigmata associated with the syndrome. This overview will present our present knowledge regarding the varied phenotypic manifestations of FA and procedures for diagnosis based upon abnormal DNA damage responses. PMID:19622403

  19. Heterozygosity for p53 (Trp53+/-) accelerates epithelial tumor formation in fanconi anemia complementation group D2 (Fancd2) knockout mice.

    PubMed

    Houghtaling, Scott; Granville, Laura; Akkari, Yassmine; Torimaru, Yumi; Olson, Susan; Finegold, Milton; Grompe, Markus

    2005-01-01

    Fanconi anemia (FA) is an autosomal recessive disease characterized by progressive bone marrow failure and an increased susceptibility to cancer. FA is genetically heterogeneous, consisting of at least 11 complementation groups, FA-A through L, including FA-D1 (BRCA2) and D2. We have previously reported an increased incidence of epithelial tumors in Fancd2 knockout mice. To further investigate the role of the FA pathway in tumor prevention, Fancd2 mutant mice were crossed to mice with a null mutation in the tumor suppressor gene, Trp53. The tumor spectrum in Fancd2(-/-)/Trp53(+/-) mice included sarcomas expected in Trp53 heterozygotes, as well as mammary and lung adenocarcinomas that occur rarely in Trp53 heterozygotes. These tumors occurred earlier than in Fancd2(-/-) control mice. Therefore, the Fancd2(-/-)/Trp53(+/-) mice represent an improved model for the study of adenocarcinoma in FA. In addition, it was found that Fancd2(-/-) mouse embryonic fibroblasts but not Fancd2(-/-)/Trp53(-/-) mouse embryonic fibroblasts arrest following DNA damage. Therefore, Trp53 is required for the S phase checkpoint activation observed in Fancd2 mutant cells. Fancd2(-/-)/Trp53(-/-) cells showed an increase in aneuploidy and had multiple gross chromosomal rearrangements.

  20. Fanconi anemia complementation group D2 (FANCD2) functions independently of BRCA2- and RAD51-associated homologous recombination in response to DNA damage.

    PubMed

    Ohashi, Akihiro; Zdzienicka, Malgorzata Z; Chen, Junjie; Couch, Fergus J

    2005-04-15

    The BRCA2 breast cancer tumor suppressor is involved in the repair of double strand breaks and broken replication forks by homologous recombination through its interaction with DNA repair protein Rad51. Cells defective in BRCA2.FANCD1 are extremely sensitive to mitomycin C (MMC) similarly to cells deficient in any of the Fanconi anemia (FA) complementation group proteins (FANC). These observations suggest that the FA pathway and the BRCA2 and Rad51 repair pathway may be linked, although a functional connection between these pathways in DNA damage signaling remains to be determined. Here, we systematically investigated the interaction between these pathways. We show that in response to DNA damage, BRCA2-dependent Rad51 nuclear focus formation was normal in the absence of FANCD2 and that FANCD2 nuclear focus formation and mono-ubiquitination appeared normal in BRCA2-deficient cells. We report that the absence of BRCA2 substantially reduced homologous recombination repair of DNA breaks, whereas the absence of FANCD2 had little effect. Furthermore, we established that depletion of BRCA2 or Rad51 had a greater effect on cell survival in response to MMC than depletion of FANCD2 and that depletion of BRCA2 in FANCD2 mutant cells further sensitized these cells to MMC. Our results suggest that FANCD2 mediates double strand DNA break repair independently of Rad51-associated homologous recombination.

  1. Fanconi anemia proteins in telomere maintenance.

    PubMed

    Sarkar, Jaya; Liu, Yie

    2016-07-01

    Mammalian chromosome ends are protected by nucleoprotein structures called telomeres. Telomeres ensure genome stability by preventing chromosome termini from being recognized as DNA damage. Telomere length homeostasis is inevitable for telomere maintenance because critical shortening or over-lengthening of telomeres may lead to DNA damage response or delay in DNA replication, and hence genome instability. Due to their repetitive DNA sequence, unique architecture, bound shelterin proteins, and high propensity to form alternate/secondary DNA structures, telomeres are like common fragile sites and pose an inherent challenge to the progression of DNA replication, repair, and recombination apparatus. It is conceivable that longer the telomeres are, greater is the severity of such challenges. Recent studies have linked excessively long telomeres with increased tumorigenesis. Here we discuss telomere abnormalities in a rare recessive chromosomal instability disorder called Fanconi Anemia and the role of the Fanconi Anemia pathway in telomere biology. Reports suggest that Fanconi Anemia proteins play a role in maintaining long telomeres, including processing telomeric joint molecule intermediates. We speculate that ablation of the Fanconi Anemia pathway would lead to inadequate aberrant structural barrier resolution at excessively long telomeres, thereby causing replicative burden on the cell. Published by Elsevier B.V.

  2. The genetic and molecular basis of Fanconi anemia.

    PubMed

    de Winter, Johan P; Joenje, Hans

    2009-07-31

    The capacity to maintain genomic integrity is shared by all living organisms. Multiple pathways are distinguished that safeguard genomic stability, most of which have originated in primitive life forms. In human individuals, defects in these pathways are typically associated with cancer proneness. The Fanconi anemia pathway, one of these pathways, has evolved relatively late during evolution and exists - in its fully developed form - only in vertebrates. This pathway, in which thus far 13 distinct proteins have been shown to participate, appears essential for error-free DNA replication. Inactivating mutations in the corresponding genes underlie the recessive disease Fanconi anemia (FA). In the last decade the genetic basis of this disorder has been uncovered by a variety of approaches, including complementation cloning, genetic linkage analysis and protein association studies. Here we review these approaches, introduce the encoded proteins, and discuss their possible role in ensuring genomic integrity.

  3. Acquisition of Relative Interstrand Crosslinker Resistance and PARP Inhibitor Sensitivity in Fanconi Anemia Head and Neck Cancers.

    PubMed

    Lombardi, Anne J; Hoskins, Elizabeth E; Foglesong, Grant D; Wikenheiser-Brokamp, Kathryn A; Wiesmüller, Lisa; Hanenberg, Helmut; Andreassen, Paul R; Jacobs, Allison J; Olson, Susan B; Keeble, Winifred W; Hays, Laura E; Wells, Susanne I

    2015-04-15

    Fanconi anemia is an inherited disorder associated with a constitutional defect in the Fanconi anemia DNA repair machinery that is essential for resolution of DNA interstrand crosslinks. Individuals with Fanconi anemia are predisposed to formation of head and neck squamous cell carcinomas (HNSCC) at a young age. Prognosis is poor, partly due to patient intolerance of chemotherapy and radiation requiring dose reduction, which may lead to early recurrence of disease. Using HNSCC cell lines derived from the tumors of patients with Fanconi anemia, and murine HNSCC cell lines derived from the tumors of wild-type and Fancc(-/-) mice, we sought to define Fanconi anemia-dependent chemosensitivity and DNA repair characteristics. We utilized DNA repair reporter assays to explore the preference of Fanconi anemia HNSCC cells for non-homologous end joining (NHEJ). Surprisingly, interstrand crosslinker (ICL) sensitivity was not necessarily Fanconi anemia-dependent in human or murine cell systems. Our results suggest that the increased Ku-dependent NHEJ that is expected in Fanconi anemia cells did not mediate relative ICL resistance. ICL exposure resulted in increased DNA damage sensing and repair by PARP in Fanconi anemia-deficient cells. Moreover, human and murine Fanconi anemia HNSCC cells were sensitive to PARP inhibition, and sensitivity of human cells was attenuated by Fanconi anemia gene complementation. The observed reliance upon PARP-mediated mechanisms reveals a means by which Fanconi anemia HNSCCs can acquire relative resistance to the ICL-based chemotherapy that is a foundation of HNSCC treatment, as well as a potential target for overcoming chemoresistance in the chemosensitive individual. ©2015 American Association for Cancer Research.

  4. Overcoming reprogramming resistance of Fanconi anemia cells

    PubMed Central

    Müller, Lars U. W.; Milsom, Michael D.; Harris, Chad E.; Vyas, Rutesh; Brumme, Kristina M.; Parmar, Kalindi; Moreau, Lisa A.; Schambach, Axel; Park, In-Hyun; London, Wendy B.; Strait, Kelly; Schlaeger, Thorsten; DeVine, Alexander L.; Grassman, Elke; D'Andrea, Alan; Daley, George Q.

    2012-01-01

    Fanconi anemia (FA) is a recessive syndrome characterized by progressive fatal BM failure and chromosomal instability. FA cells have inactivating mutations in a signaling pathway that is critical for maintaining genomic integrity and protecting cells from the DNA damage caused by cross-linking agents. Transgenic expression of the implicated genes corrects the phenotype of hematopoietic cells, but previous attempts at gene therapy have failed largely because of inadequate numbers of hematopoietic stem cells available for gene correction. Induced pluripotent stem cells (iPSCs) constitute an alternate source of autologous cells that are amenable to ex vivo expansion, genetic correction, and molecular characterization. In the present study, we demonstrate that reprogramming leads to activation of the FA pathway, increased DNA double-strand breaks, and senescence. We also demonstrate that defects in the FA DNA-repair pathway decrease the reprogramming efficiency of murine and human primary cells. FA pathway complementation reduces senescence and restores the reprogramming efficiency of somatic FA cells to normal levels. Disease-specific iPSCs derived in this fashion maintain a normal karyotype and are capable of hematopoietic differentiation. These data define the role of the FA pathway in reprogramming and provide a strategy for future translational applications of patient-specific FA iPSCs. PMID:22371882

  5. Genetic Heterogeneity among Fanconi Anemia Heterozygotes and Risk of Cancer

    PubMed Central

    Berwick, Marianne; Satagopan, Jaya M.; Ben-Porat, Leah; Carlson, Ann; Mah, Katherine; Henry, Rashida; Diotti, Raffaella; Milton, Kelly; Pujara, Kanan; Landers, Tom; Batish, Sat Dev; Morales, José; Schindler, Detlev; Hanenberg, Helmut; Hromas, Robert; Levran, Orna; Auerbach, Arleen D.

    2013-01-01

    Fanconi anemia (FA) is a rare autosomal recessive disease characterized by a greatly increased risk of cancer among those diagnosed with the syndrome. The question as to whether FA heterozygotes are at increased risk for cancer is of great importance to those at risk for being a carrier. To address this question, we formed a cohort of grandparents of probands identified through the International Fanconi Anemia Registry. We obtained informed consent, a short questionnaire, and either blood or buccal swab DNA. After diagnosis of the proband was confirmed and complementation studies or DNA sequencing on the proband were completed, mutation analyses of the putative carriers and noncarriers was carried out. Standardized incidence ratios (SIR) were calculated to compare the observed cancer incidence of the grandparents and other relatives with the expected rates of cancer, using the Surveillance, Epidemiology, and End Results registries and the Connecticut Cancer registry. In the 944 study subjects who participated (784 grandparents and 160 other relatives), there was no suggestion of an increase in overall cancer incidence. On the other hand, a significantly higher rate of breast cancer than expected was observed among carrier grandmothers [SIR, 1.7; 95% confidence interval (95% CI), 1.1–2.7]. Among the grandmothers, those who were carriers of FANCC mutations were found to be at highest risk (SIR, 2.4; 95% CI, 1.1–5.2). Overall, there was no increased risk for cancer among FA heterozygotes in this study of Fanconi relatives, although there is some evidence that FANCC mutations are possibly breast cancer susceptibility alleles. PMID:17909071

  6. A male newborn with VACTERL association and Fanconi anemia with a FANCB deletion detected by array comparative genomic hybridization (aCGH).

    PubMed

    Umaña, Luis A; Magoulas, Pilar; Bi, Weimin; Bacino, Carlos A

    2011-12-01

    We report on a male newborn with multiple congenital abnormalities consistent with the diagnosis of VACTERL association (vertebral, anal, cardiac, tracheo-esophageal fistula, renal, and limb anomalies), who had Fanconi anemia (complementation group B) recognized by the detection of a deletion in chromosome Xp22.2 using an oligonucleotide array. The diagnosis of Fanconi anemia was confirmed by increased chromosomal breakage abnormalities observed in cultured cells that were treated with cross-linking agents. This is the first report in the literature of Fanconi anemia complementation group B detected by oligonucleotide array testing postnatally.

  7. Effects of ionizing radiation on cells from Fanconi's anemia patients

    SciTech Connect

    Duckworth-Rysiecki, G.; Taylor, A.M.

    1985-01-01

    The lymphocytes from some Fanconi's anemia patients appeared to be more radiosensitive than normal as measured by the number of X-ray-(or bleomycin-) induced chromosome aberrations seen following G2 treatment. Fibroblasts from the same patients, however, all showed the same degree of colony survival as normals following exposure to gamma-rays (Do, 1.13 +/- 0.072 (S.E.) Gy and 1.14 +/- 0.077 Gy for Fanconi's anemia and normal fibroblasts, respectively). The lack of increased radiosensitivity in Fanconi's fibroblasts was also observed by the same degree of inhibition of DNA synthesis as seen in normals following gamma-irradiation. The results show clearly that there is no increase in radiosensitivity common to all cell types from Fanconi's patients, although an apparent increase in chromosomal radiosensitivity may be seen in the lymphocytes from an occasional patient.

  8. Mutation analysis of the Fanconi Anemia Gene FACC

    SciTech Connect

    Verlander, P.C.; Lin, J.D.; Udono, M.U.; Zhang, Q.; Auerbach, A.D. ); Gibson, R.A.; Mathew, C.G. )

    1994-04-01

    Fanconi anemia (FA) is a genetically heterogeneous autosomal recessive disorder characterized by a unique hypersensitivity of cells to DNA cross-linking agents; a gene for complementation group C (FACC) has recently been cloned. The authors have amplified FACC exons with their flanking intron sequences from genomic DNA from 174 racially and ethnically diverse families in the International Fanconi Anemia Registry and have screened for mutations by using SSCP analysis. They have identified eight different variants in 32 families; three were detected in exon 1, one in exon 4, one in intron 4, two in exon 6, and one in exon 14. Two of the eight variants, in seven families, did not segregate with the disease allele in multiplex families, suggesting that these variants represented benign polymorphisms. Disease-associated mutations in FACC were detected in a total of 25 (14.4%) of 174 families screened. The most frequent mutations were IVS4 + 4 A [yields] T (intron 4; 12 families) and 322delG (exon 1; 9 families). Other, less common mutations include Q13X in exon 1, R185X and D195V in exon 6, and L554P in exon 14. The polymorphisms were S26F in exon 1 and G139E in exon 4. All patients in the study with 322delG, Q13X, R185X, and D195V are of northern or eastern European or southern Italian ancestry, and 18 of 19 have a mild form of the disease, while the 2 patients with L554P, both from the same family, have a severe phenotype. All 19 patients with IVS4 + 4 A [yields] T have Jewish ancestry and have a severe phenotype. 19 refs., 1 fig., 3 tabs.

  9. Fanconi Anemia: A Rarely Considered Cause of Macrocytosis During Childhood.

    PubMed

    Aslan, Deniz

    2017-10-01

    We describe a Turkish boy newly diagnosed with Fanconi anemia with mutation in the FANCA gene. The patient, with normal clinical phenotype and negative chromosomal breakage test result, presented with macrocytosis. No clinical or laboratory changes were observed in a follow-up period of 4 years. The diagnosis was confirmed molecularly after a prolonged and exhaustive investigation. He was found to be a compound heterozygote for 2 mutations in the FANCA gene (1 of which is novel, c.4261-2A>C). We present this experience to alert physicians that Fanconi anemia should be considered in the differential diagnosis of otherwise unexplained macrocytosis during childhood.

  10. UBE2W interacts with FANCL and regulates the monoubiquitination of Fanconi anemia protein FANCD2.

    PubMed

    Zhang, Yingying; Zhou, Xiaowei; Zhao, Lixia; Li, Chao; Zhu, Hengqi; Xu, Long; Shan, Liran; Liao, Xiang; Guo, Zekun; Huang, Peitang

    2011-02-01

    Fanconi anemia (FA) is a rare cancer-predisposing genetic disease mostly caused by improper regulation of the monoubiquitination of Fanconi anemia complementation group D2 (FANCD2). Genetic studies have indicated that ubiquitin conjugating enzyme UBE2T and HHR6 could regulate FANCD2 monoubiquitination through distinct mechanisms. However, the exact regulation mechanisms of FANCD2 monoubiquitination in response to different DNA damages remain unclear. Here we report that UBE2W, a new ubiquitin conjugating enzyme, could regulate FANCD2 monoubiquitination by mechanisms different from UBE2T or HHR6. Indeed, UBE2W exhibits ubiquitin conjugating enzyme activity and catalyzes the monoubiquitination of PHD domain of Fanconi anemia complementation group L (FANCL) in vitro. UBE2W binds to FANCL, and the PHD domain is both necessary and sufficient for this interaction in mammalian cells. In addition, over-expression of UBE2W in cells promotes the monoubiquitination of FANCD2 and down-regulated UBE2W markedly reduces the UV irradiation-induced but not MMC-induced FANCD2 monoubiquitination. These results indicate that UBE2W regulates FANCD2 monoubiquitination by mechanisms different from UBE2T and HRR6. It may provide an additional regulatory step in the activation of the FA pathway.

  11. UBE2W Interacts with FANCL and Regulates the Monoubiquitination of Fanconi Anemia Protein FANCD2

    PubMed Central

    Zhang, Yingying; Zhou, Xiaowei; Zhao, Lixia; Li, Chao; Zhu, Hengqi; Xu, Long; Shan, Liran; Liao, Xiang; Guo, Zekun; Huang, Peitang

    2011-01-01

    Fanconi anemia (FA) is a rare cancer-predisposing genetic disease mostly caused by improper regulation of the monoubiquitination of Fanconi anemia complementation group D2 (FANCD2). Genetic studies have indicated that ubiquitin conjugating enzyme UBE2T and HHR6 could regulate FANCD2 monoubiquitination through distinct mechanisms. However, the exact regulation mechanisms of FANCD2 monoubiquitination in response to different DNA damages remain unclear. Here we report that UBE2W, a new ubiquitin conjugating enzyme, could regulate FANCD2 monoubiquitination by mechanisms different from UBE2T or HHR6. Indeed, UBE2W exhibits ubiquitin conjugating enzyme activity and catalyzes the monoubiquitination of PHD domain of Fanconi anemia complementation group L (FANCL) in vitro. UBE2W binds to FANCL, and the PHD domain is both necessary and sufficient for this interaction in mammalian cells. In addition, overexpression of UBE2W in cells promotes the monoubiquitination of FANCD2 and down-regulated UBE2W markedly reduces the UV irradiation-induced but not MMC-induced FANCD2 monoubiquitination. These results indicate that UBE2W regulates FANCD2 monoubiquitination by mechanisms different from UBE2T and HRR6. It may provide an additional regulatory step in the activation of the FA pathway. PMID:21229326

  12. Fanconi anemia with concurrent thumb polydactyly and dorsal dimelia: a case report with discussion of embryology.

    PubMed

    Al-Qattan, M M

    2013-01-01

    Fanconi anemia is known to be associated with radial ray deficiency (thumb and radius hypoplasia), and its embryological basis remains to be poorly understood. We describe a rare case of Fanconi anemia with concurrent thumb polydactyly and dorsal dimelia. The embryological basis of limb abnormalities in Fanconi anemia patients is thought to be based on the complex interactions between the apical ectodermal ridge (where Fanconi anemia genes are expressed) and both the mesoderm (where Spalt-like 4 (SALL4) and Sonic hedgehog (SHH) are located and which are responsible for radial ray deficiency, thumb polydactyly, and triphalangism) and the dorsoventral axis (an error in that axis leads to dorsal dimelia).

  13. Anesthesia for a patient with Fanconi anemia for developmental dislocation of the hip: a case report.

    PubMed

    Dogan, Zafer; Yildiz, Huseyin; Coskuner, Ismail; Uzel, Murat; Garipardic, Mesut

    2014-01-01

    Fanconi anemia is a rare autosomal recessive inherited bone marrow failure syndrome with congenital and hematological abnormalities. Literature regarding the anesthetic management in these patients is limited. A management of a developmental dislocation of the hip was described in a patient with fanconi anemia. Because of the heterogeneous nature, a patient with fanconi anemia should be established thorough preoperative evaluation in order to diagnose on clinical features. In conclusion, we preferred caudal anesthesia in this patient with fanconi anemia without thrombocytopenia, because of avoiding from N2O, reducing amount of anesthetic, existing microcephaly, hypothyroidism and elevated liver enzymes, providing postoperative analgesia, and reducing amount of analgesic used postoperatively.

  14. The deubiquitinating enzyme USP1 regulates the Fanconi anemia pathway.

    PubMed

    Nijman, Sebastian M B; Huang, Tony T; Dirac, Annette M G; Brummelkamp, Thijn R; Kerkhoven, Ron M; D'Andrea, Alan D; Bernards, René

    2005-02-04

    Protein ubiquitination and deubiquitination are dynamic processes implicated in the regulation of numerous cellular pathways. Monoubiquitination of the Fanconi anemia (FA) protein FANCD2 appears to be critical in the repair of DNA damage because many of the proteins that are mutated in FA are required for FANCD2 ubiquitination. By screening a gene family RNAi library, we identify the deubiquitinating enzyme USP1 as a novel component of the Fanconi anemia pathway. Inhibition of USP1 leads to hyperaccumulation of monoubiquitinated FANCD2. Furthermore, USP1 physically associates with FANCD2, and the proteins colocalize in chromatin after DNA damage. Finally, analysis of crosslinker-induced chromosomal aberrations in USP1 knockdown cells suggests a role in DNA repair. We propose that USP1 deubiquitinates FANCD2 when cells exit S phase or recommence cycling after a DNA damage insult and may play a critical role in the FA pathway by recycling FANCD2.

  15. Disruption of mouse Slx4, a regulator of structure-specific nucleases, phenocopies Fanconi anemia.

    PubMed

    Crossan, Gerry P; van der Weyden, Louise; Rosado, Ivan V; Langevin, Frederic; Gaillard, Pierre-Henri L; McIntyre, Rebecca E; Gallagher, Ferdia; Kettunen, Mikko I; Lewis, David Y; Brindle, Kevin; Arends, Mark J; Adams, David J; Patel, Ketan J

    2011-02-01

    The evolutionarily conserved SLX4 protein, a key regulator of nucleases, is critical for DNA damage response. SLX4 nuclease complexes mediate repair during replication and can also resolve Holliday junctions formed during homologous recombination. Here we describe the phenotype of the Btbd12 knockout mouse, the mouse ortholog of SLX4, which recapitulates many key features of the human genetic illness Fanconi anemia. Btbd12-deficient animals are born at sub-Mendelian ratios, have greatly reduced fertility, are developmentally compromised and are prone to blood cytopenias. Btbd12(-/-) cells prematurely senesce, spontaneously accumulate damaged chromosomes and are particularly sensitive to DNA crosslinking agents. Genetic complementation reveals a crucial requirement for Btbd12 (also known as Slx4) to interact with the structure-specific endonuclease Xpf-Ercc1 to promote crosslink repair. The Btbd12 knockout mouse therefore establishes a disease model for Fanconi anemia and genetically links a regulator of nuclease incision complexes to the Fanconi anemia DNA crosslink repair pathway.

  16. A comprehensive strategy for the subtyping of patients with Fanconi anaemia: conclusions from the Spanish Fanconi Anemia Research Network

    PubMed Central

    Casado, José Antonio; Callén, Elsa; Jacome, Ariana; Río, Paula; Castella, Maria; Lobitz, Stephan; Ferro, Teresa; Muñoz, Arturo; Sevilla, Julián; Cantalejo, Ángeles; Cela, Elena; Cervera, José; Sánchez‐Calero, Jesús; Badell, Isabel; Estella, Jesús; Dasí, Ángeles; Olivé, Teresa; Ortega, Juan José; Rodriguez‐Villa, Antonia; Tapia, María; Molinés, Antonio; Madero, Luis; Segovia, José C; Neveling, Kornelia; Kalb, Reinhard; Schindler, Detlev; Hanenberg, Helmut; Surrallés, Jordi; Bueren, Juan A

    2007-01-01

    Background Fanconi anaemia is a heterogeneous genetic disease, where 12 complementation groups have been already described. Identifying the complementation group in patients with Fanconi anaemia constitutes a direct procedure to confirm the diagnosis of the disease and is required for the recruitment of these patients in gene therapy trials. Objective To determine the subtype of Fanconi anaemia patients in Spain, a Mediterranean country with a relatively high population (23%) of Fanconi anaemia patients belonging to the gypsy race. Methods Most patients could be subtyped by retroviral complementation approaches in peripheral blood T cells, although some mosaic patients were subtyped in cultured skin fibroblasts. Other approaches, mainly based on western blot analysis and generation of nuclear RAD51 and FANCJ foci, were required for the subtyping of a minor number of patients. Results and conclusions From a total of 125 patients included in the Registry of Fanconi Anaemia, samples from 102 patients were available for subtyping analyses. In 89 cases the subtype could be determined and in 8 cases exclusions of common complementation groups were made. Compared with other international studies, a skewed distribution of complementation groups was observed in Spain, where 80% of the families belonged to the Fanconi anaemia group A (FA‐A) complementation group. The high proportion of gypsy patients, all of them FA‐A, and the absence of patients with FA‐C account for this characteristic distribution of complementation groups. PMID:17105750

  17. Fanconi anemia links reactive oxygen species to insulin resistance and obesity.

    PubMed

    Li, Jie; Sipple, Jared; Maynard, Suzette; Mehta, Parinda A; Rose, Susan R; Davies, Stella M; Pang, Qishen

    2012-10-15

    Insulin resistance is a hallmark of obesity and type 2 diabetes. Reactive oxygen species (ROS) have been proposed to play a causal role in insulin resistance. However, evidence linking ROS to insulin resistance in disease settings has been scant. Since both oxidative stress and diabetes have been observed in patients with the Fanconi anemia (FA), we sought to investigate the link between ROS and insulin resistance in this unique disease model. Mice deficient for the Fanconi anemia complementation group A (Fanca) or Fanconi anemia complementation group C (Fancc) gene seem to be diabetes-prone, as manifested by significant hyperglycemia and hyperinsulinemia, and rapid weight gain when fed with a high-fat diet. These phenotypic features of insulin resistance are characterized by two critical events in insulin signaling: a reduction in tyrosine phosphorylation of the insulin receptor (IR) and an increase in inhibitory serine phosphorylation of the IR substrate-1 in the liver, muscle, and fat tissues from the insulin-challenged FA mice. High levels of ROS, spontaneously accumulated or generated by tumor necrosis factor alpha in these insulin-sensitive tissues of FA mice, were shown to underlie the FA insulin resistance. Treatment of FA mice with the natural anti-oxidant Quercetin restores IR signaling and ameliorates the diabetes- and obesity-prone phenotypes. Finally, pairwise screen identifies protein-tyrosine phosphatase (PTP)-α and stress kinase double-stranded RNA-dependent protein kinase (PKR) that mediate the ROS effect on FA insulin resistance. These findings establish a pathogenic and mechanistic link between ROS and insulin resistance in a unique human disease setting. ROS accumulation contributes to the insulin resistance in FA deficiency by targeting both PTP-α and PKR.

  18. Successful Treatment of Hepatocellular Carcinoma Complicated by Fanconi Anemia

    PubMed Central

    Takahashi, Koji; Suzuki, Eiichiro; Yokoyama, Masayuki; Inoue, Masanori; Wakamatsu, Toru; Saito, Tomoko; Kusakabe, Yuko; Ogasawara, Sadahisa; Ooka, Yoshihiko; Tawada, Akinobu; Nagao, Yuhei; Nakaseko, Chiaki; Chiba, Tetsuhiro

    2017-01-01

    A 42-year-old woman with liver tumors was referred to our hospital. Her condition was complicated by Fanconi anemia, and she had undergone total laryngectomy 8 years ago. On admission, contrast-enhanced computed tomography revealed hypervascular tumors in the right hepatic lobe. Ultrasound-guided tumor biopsy revealed that the tumor comprised moderately differentiated hepatocellular carcinoma. Although the patient exhibited preserved liver function (Child-Pugh A), complete blood count revealed severe pancytopenia. Eventually, the tumor was successfully treated by transcatheter arterial embolization (TAE). Both platelet transfusion and systemic administration of antibiotics were performed. She was discharged 35 days after TAE. PMID:28203135

  19. Linkage analysis of the Fanconi anemia gene FACC with chromosome 9q markers

    SciTech Connect

    Auerbach, A.D.; Shin, H.T.; Kaporis, A.G.

    1994-09-01

    Fanconi anemia (FA) is a genetically heterogeneous syndrome, with at least four different complementation groups as determined by cell fusion studies. The gene for complementation group C, FACC, has been cloned and mapped to chromosome 9q22.3 by in situ hybridization, while linkage analysis has supported the placement of another gene on chromosome 20q. We have analyzed five microsatellite markers and one RFLP on chromosome 9q in a panel of FA families from the International Fanconi Anemia Registry (IFAR) in order to place FACC on the genetic map. Polymorphisms were typed in 308 individuals from 51 families. FACC is tightly linked to both D9S151 [{Theta}{sub max}=0.025, Z{sub max}=7.75] and to D9S196 [{Theta}{sub max}=0.041, Z{sub max}=7.89]; multipoint analysis is in progress. We are currently screening a YAC clone that contains the entire FACC gene for additional microsatellite markers suitable for haplotype analysis of FA families.

  20. A simple diagnostic test for Fanconi anemia by flow cytometry.

    PubMed

    Miglierina, R; Le Coniat, M; Berger, R

    1991-03-01

    A simple diagnostic test for Fanconi anemia (FA) by flow cytometry is proposed. It is based on the cell cycle disturbances of FA cells and their sensitisation by alkylating agents. Following PHA-stimulation of whole blood cell cultures in the presence or absence of nitrogen mustard, the accumulation of cells in G2/M phase was measured. A sharp increase of cells in G2/M was observed in cultures from FA patients when nitrogen mustard was added. This increase allows one to distinguish FA patients from patients with anemias of other origin, healthy controls, and FA heterozygotes, as effectively as chromosome breakage studies. The rapidity of the test and its reliability as demonstrated on the ten FA patients studied, will make the diagnosis of FA easier in centers without cytogenetic laboratory facilities.

  1. Endocrine disorders in Fanconi anemia: recommendations for screening and treatment.

    PubMed

    Petryk, Anna; Kanakatti Shankar, Roopa; Giri, Neelam; Hollenberg, Anthony N; Rutter, Meilan M; Nathan, Brandon; Lodish, Maya; Alter, Blanche P; Stratakis, Constantine A; Rose, Susan R

    2015-03-01

    Endocrine problems are common in patients with Fanconi anemia (FA). About 80% of children and adults with FA have at least one endocrine abnormality, including short stature, GH deficiency, abnormal glucose or insulin metabolism, dyslipidemia, hypothyroidism, pubertal delay, hypogonadism, or impaired fertility. The goal of this report is to provide an overview of endocrine abnormalities and guidelines for routine screening and treatment to allow early diagnosis and timely intervention. This work is based on a comprehensive literature review, including relevant articles published between 1971 and 2014, and proceedings of a Consensus Conference held by the Fanconi Anemia Research Fund in 2013. The panel of experts collected published evidence and discussed its relevance to reflect current information about the endocrine care of children and adults with FA before the Consensus Conference and through subsequent deliberations that led to the consensus. Individuals with FA should be routinely screened for endocrine abnormalities, including evaluation of growth; glucose, insulin, and lipid metabolism; thyroid function; puberty; gonadal function; and bone mineral metabolism. Inclusion of an endocrinologist as part of the multidisciplinary patient care team is key to providing comprehensive care for patients with FA.

  2. Mechanism of Ubiquitination and Deubiquitination in the Fanconi Anemia Pathway.

    PubMed

    van Twest, Sylvie; Murphy, Vincent J; Hodson, Charlotte; Tan, Winnie; Swuec, Paolo; O'Rourke, Julienne J; Heierhorst, Jörg; Crismani, Wayne; Deans, Andrew J

    2017-01-19

    Monoubiquitination and deubiquitination of FANCD2:FANCI heterodimer is central to DNA repair in a pathway that is defective in the cancer predisposition syndrome Fanconi anemia (FA). The "FA core complex" contains the RING-E3 ligase FANCL and seven other essential proteins that are mutated in various FA subtypes. Here, we purified recombinant FA core complex to reveal the function of these other proteins. The complex contains two spatially separate FANCL molecules that are dimerized by FANCB and FAAP100. FANCC and FANCE act as substrate receptors and restrict monoubiquitination to the FANCD2:FANCI heterodimer in only a DNA-bound form. FANCA and FANCG are dispensable for maximal in vitro ubiquitination. Finally, we show that the reversal of this reaction by the USP1:UAF1 deubiquitinase only occurs when DNA is disengaged. Our work reveals the mechanistic basis for temporal and spatial control of FANCD2:FANCI monoubiquitination that is critical for chemotherapy responses and prevention of Fanconi anemia.

  3. Endocrine Disorders in Fanconi Anemia: Recommendations for Screening and Treatment

    PubMed Central

    Kanakatti Shankar, Roopa; Giri, Neelam; Hollenberg, Anthony N.; Rutter, Meilan M.; Nathan, Brandon; Lodish, Maya; Alter, Blanche P.; Stratakis, Constantine A.

    2015-01-01

    Context: Endocrine problems are common in patients with Fanconi anemia (FA). About 80% of children and adults with FA have at least one endocrine abnormality, including short stature, GH deficiency, abnormal glucose or insulin metabolism, dyslipidemia, hypothyroidism, pubertal delay, hypogonadism, or impaired fertility. The goal of this report is to provide an overview of endocrine abnormalities and guidelines for routine screening and treatment to allow early diagnosis and timely intervention. Evidence Acquisition: This work is based on a comprehensive literature review, including relevant articles published between 1971 and 2014, and proceedings of a Consensus Conference held by the Fanconi Anemia Research Fund in 2013. Evidence Synthesis: The panel of experts collected published evidence and discussed its relevance to reflect current information about the endocrine care of children and adults with FA before the Consensus Conference and through subsequent deliberations that led to the consensus. Conclusions: Individuals with FA should be routinely screened for endocrine abnormalities, including evaluation of growth; glucose, insulin, and lipid metabolism; thyroid function; puberty; gonadal function; and bone mineral metabolism. Inclusion of an endocrinologist as part of the multidisciplinary patient care team is key to providing comprehensive care for patients with FA. PMID:25575015

  4. The antitumor agent doxorubicin binds to Fanconi anemia group F protein.

    PubMed

    Kusayanagi, Tomoe; Tsukuda, Senko; Shimura, Satomi; Manita, Daisuke; Iwakiri, Kanako; Kamisuki, Shinji; Takakusagi, Yoichi; Takeuchi, Toshifumi; Kuramochi, Kouji; Nakazaki, Atsuo; Sakaguchi, Kengo; Kobayashi, Susumu; Sugawara, Fumio

    2012-11-01

    Doxorubicin, a commonly used cancer chemotherapy agent, elicits several potent biological effects, including synergistic-antitumor activity in combination with cisplatin. However, the mechanism of this synergism remains obscure. Here, we employed an improved T7 phage display screening method to identify Fanconi anemia group F protein (FANCF) as a doxorubicin-binding protein. The FANCF-doxorubicin interaction was confirmed by pull-down assay and SPR analysis. FANCF is a component of the Fanconi anemia complex, which monoubiquitinates D2 protein of Fanconi anemia group as a cellular response against DNA cross-linkers such as cisplatin. We observed that the monoubiquitination was inhibited by doxorubicin treatment.

  5. Stem Cell Gene Therapy for Fanconi Anemia: Report from the 1st International Fanconi Anemia Gene Therapy Working Group Meeting

    PubMed Central

    Tolar, Jakub; Adair, Jennifer E; Antoniou, Michael; Bartholomae, Cynthia C; Becker, Pamela S; Blazar, Bruce R; Bueren, Juan; Carroll, Thomas; Cavazzana-Calvo, Marina; Clapp, D Wade; Dalgleish, Robert; Galy, Anne; Gaspar, H Bobby; Hanenberg, Helmut; Von Kalle, Christof; Kiem, Hans-Peter; Lindeman, Dirk; Naldini, Luigi; Navarro, Susana; Renella, Raffaele; Rio, Paula; Sevilla, Julián; Schmidt, Manfred; Verhoeyen, Els; Wagner, John E; Williams, David A; Thrasher, Adrian J

    2011-01-01

    Survival rates after allogeneic hematopoietic cell transplantation (HCT) for Fanconi anemia (FA) have increased dramatically since 2000. However, the use of autologous stem cell gene therapy, whereby the patient's own blood stem cells are modified to express the wild-type gene product, could potentially avoid the early and late complications of allogeneic HCT. Over the last decades, gene therapy has experienced a high degree of optimism interrupted by periods of diminished expectation. Optimism stems from recent examples of successful gene correction in several congenital immunodeficiencies, whereas diminished expectations come from the realization that gene therapy will not be free of side effects. The goal of the 1st International Fanconi Anemia Gene Therapy Working Group Meeting was to determine the optimal strategy for moving stem cell gene therapy into clinical trials for individuals with FA. To this end, key investigators examined vector design, transduction method, criteria for large-scale clinical-grade vector manufacture, hematopoietic cell preparation, and eligibility criteria for FA patients most likely to benefit. The report summarizes the roadmap for the development of gene therapy for FA. PMID:21540837

  6. Pregnancy after allogeneic hematopoietic stem cell transplantation in a Fanconi anemia patient

    PubMed Central

    Atashkhoei, Simin; Fakhari, Solmaz; Bilehjani, Eissa; Farzin, Haleh

    2017-01-01

    Pregnancy in patients with Fanconi anemia (FA) is rare. However, there are reports of successful pregnancy in Fanconi patients after bone marrow transplantation (BMT, hematopoietic stem cell transplantation). We describe the case of a term pregnant woman with FA who was treated with BMT 2 years earlier. She underwent successful delivery with cesarean section using spinal anesthesia without any complications. PMID:28138266

  7. RAD18-mediated ubiquitination of PCNA activates the Fanconi anemia DNA repair network.

    PubMed

    Geng, Liyi; Huntoon, Catherine J; Karnitz, Larry M

    2010-10-18

    The Fanconi anemia (FA) network is important for the repair of interstrand DNA cross-links. A key event in FA pathway activation is the monoubiquitylation of the FA complementation group I (FANCI)-FANCD2 (ID) complex by FA complementation group L (FANCL), an E3 ubiquitin ligase. In this study, we show that RAD18, another DNA damage-activated E3 ubiquitin ligase, also participates in ID complex activation by ubiquitylating proliferating cell nuclear antigen (PCNA) on Lys164, an event required for the recruitment of FANCL to chromatin. We also found that monoubiquitylated PCNA stimulates FANCL-catalyzed FANCD2 and FANCI monoubiquitylation. Collectively, these experiments identify RAD18-mediated PCNA monoubiquitination as a central hub for the mobilization of the FA pathway by promoting FANCL-mediated FANCD2 monoubiquitylation.

  8. Fanconi's Anemia Effect or Sickle Cell Anemia Effect: That is the Question.

    PubMed

    Unal, Sule; Chui, David H K; Gumruk, Fatma

    2015-01-01

    A 16-year-old boy who was diagnosed to have sickle cell anemia was referred to our center. The parental consanguinity, growth retardation and dysmorphic features prompted a search for possible Fanconi's Anemia (FA). The diepoxybutane (DEB) test was positive, confirming FA. The interaction of both diseases might account for his relatively mild phenotype in terms of both sickle cell anemia (or Hb S, HBB: c.20A > T) and FA. The high Hb F level that might be related to concomitant FA, may have caused a milder phenotype of sickle cell anemia, whereas nitric oxide (NO) depletion as a consequence of sickle cell anemia, may have caused a delay in the bone marrow failure of FA.

  9. Defective FANCI binding by a fanconi anemia-related FANCD2 mutant.

    PubMed

    Sato, Koichi; Ishiai, Masamichi; Takata, Minoru; Kurumizaka, Hitoshi

    2014-01-01

    FANCD2 is a product of one of the genes associated with Fanconi anemia (FA), a rare recessive disease characterized by bone marrow failure, skeletal malformations, developmental defects, and cancer predisposition. FANCD2 forms a complex with FANCI (ID complex) and is monoubiquitinated, which facilitates the downstream interstrand crosslink (ICL) repair steps, such as ICL unhooking and nucleolytic end resection. In the present study, we focused on the chicken FANCD2 (cFANCD2) mutant harboring the Leu234 to Arg (L234R) substitution. cFANCD2 L234R corresponds to the human FANCD2 L231R mutation identified in an FA patient. We found that cFANCD2 L234R did not complement the defective ICL repair in FANCD2-/- DT40 cells. Purified cFANCD2 L234R did not bind to chicken FANCI, and its monoubiquitination was significantly deficient, probably due to the abnormal ID complex formation. In addition, the histone chaperone activity of cFANCD2 L234R was also defective. These findings may explain some aspects of Fanconi anemia pathogenesis by a FANCD2 missense mutation.

  10. Defective FANCI Binding by a Fanconi Anemia-Related FANCD2 Mutant

    PubMed Central

    Sato, Koichi; Ishiai, Masamichi; Takata, Minoru; Kurumizaka, Hitoshi

    2014-01-01

    FANCD2 is a product of one of the genes associated with Fanconi anemia (FA), a rare recessive disease characterized by bone marrow failure, skeletal malformations, developmental defects, and cancer predisposition. FANCD2 forms a complex with FANCI (ID complex) and is monoubiquitinated, which facilitates the downstream interstrand crosslink (ICL) repair steps, such as ICL unhooking and nucleolytic end resection. In the present study, we focused on the chicken FANCD2 (cFANCD2) mutant harboring the Leu234 to Arg (L234R) substitution. cFANCD2 L234R corresponds to the human FANCD2 L231R mutation identified in an FA patient. We found that cFANCD2 L234R did not complement the defective ICL repair in FANCD2−/− DT40 cells. Purified cFANCD2 L234R did not bind to chicken FANCI, and its monoubiquitination was significantly deficient, probably due to the abnormal ID complex formation. In addition, the histone chaperone activity of cFANCD2 L234R was also defective. These findings may explain some aspects of Fanconi anemia pathogenesis by a FANCD2 missense mutation. PMID:25489943

  11. Hearing loss and speech perception in noise difficulties in Fanconi anemia.

    PubMed

    Verheij, Emmy; Oomen, Karin P Q; Smetsers, Stephanie E; van Zanten, Gijsbert A; Speleman, Lucienne

    2017-10-01

    Fanconi anemia is a hereditary chromosomal instability disorder. Hearing loss and ear abnormalities are among the many manifestations reported in this disorder. In addition, Fanconi anemia patients often complain about hearing difficulties in situations with background noise (speech perception in noise difficulties). Our study aimed to describe the prevalence of hearing loss and speech perception in noise difficulties in Dutch Fanconi anemia patients. Retrospective chart review. A retrospective chart review was conducted at a Dutch tertiary care center. All patients with Fanconi anemia at clinical follow-up in our hospital were included. Medical files were reviewed to collect data on hearing loss and speech perception in noise difficulties. In total, 49 Fanconi anemia patients were included. Audiograms were available in 29 patients and showed hearing loss in 16 patients (55%). Conductive hearing loss was present in 24.1%, sensorineural in 20.7%, and mixed in 10.3%. A speech in noise test was performed in 17 patients; speech perception in noise was subnormal in nine patients (52.9%) and abnormal in two patients (11.7%). Hearing loss and speech perception in noise abnormalities are common in Fanconi anemia. Therefore, pure tone audiograms and speech in noise tests should be performed, preferably already at a young age, because hearing aids or assistive listening devices could be very valuable in developing language and communication skills. 4. Laryngoscope, 127:2358-2361, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  12. Regulation of Rev1 by the Fanconi Anemia Core Complex

    PubMed Central

    Kim, Hyungjin; Yang, Kailin; Dejsuphong, Donniphat; D’Andrea, Alan D.

    2011-01-01

    The fifteen known Fanconi Anemia (FA) proteins cooperate in a pathway which regulates DNA interstrand crosslink repair. Recent studies indicate that the FA pathway also controls Rev1-mediated translesion DNA synthesis (TLS). Here we identify a novel protein FAAP20, which is an integral subunit of the multisubunit FA core complex. FAAP20 binds to FANCA subunit and is required for complex stability and monoubiquitination of FANCD2. FAAP20 contains a UBZ4 (Ubiquitin Binding Zinc finger 4) domain and binds to the monoubiquitinated form of Rev1. FAAP20 binding stabilizes Rev1 nuclear foci and promotes the interaction of the FA core with PCNA/Rev1 DNA damage bypass complexes. FAAP20 therefore provides a critical link between the FA pathway and TLS polymerase activity. We propose that the FA core complex regulates crosslink repair, by channeling lesions to damage bypass pathways and preventing large DNA insertions and deletions. PMID:22266823

  13. Cellular therapy for fanconi anemia: the past, present, and future.

    PubMed

    MacMillan, Margaret L; Hughes, Mark R; Agarwal, Suneet; Daley, George Q

    2011-01-01

    Allogeneic hematopoietic cell transplantation (HCT) remains the only proven curative therapy for the hematologic manifestation of Fanconi anemia (FA). Over the past 2 decades, major advances have been made such that transplant outcomes have markedly improved. With the development of in vitro fertilization and preimplantation genetic diagnosis, HLA-matched sibling donor umbilical blood transplantation may be an option for more patients with FA. Recently, the use of pluripotent stem cells has been explored as a novel approach to model the hematopoietic developmental defects in FA, and to provide a potential source of autologous stem cells that can be genetically manipulated and used to generate corrected hematopoietic progenitors. Copyright © 2011 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  14. Modularized functions of the Fanconi anemia core complex.

    PubMed

    Huang, Yaling; Leung, Justin W C; Lowery, Megan; Matsushita, Nobuko; Wang, Yucai; Shen, Xi; Huong, Do; Takata, Minoru; Chen, Junjie; Li, Lei

    2014-06-26

    The Fanconi anemia (FA) core complex provides the essential E3 ligase function for spatially defined FANCD2 ubiquitination and FA pathway activation. Of the seven FA gene products forming the core complex, FANCL possesses a RING domain with demonstrated E3 ligase activity. The other six components do not have clearly defined roles. Through epistasis analyses, we identify three functional modules in the FA core complex: a catalytic module consisting of FANCL, FANCB, and FAAP100 is absolutely required for the E3 ligase function, and the FANCA-FANCG-FAAP20 and the FANCC-FANCE-FANCF modules provide nonredundant and ancillary functions that help the catalytic module bind chromatin or sites of DNA damage. Disruption of the catalytic module causes complete loss of the core complex function, whereas loss of any ancillary module component does not. Our work reveals the roles of several FA gene products with previously undefined functions and a modularized assembly of the FA core complex.

  15. Impaired mitophagy in Fanconi anemia is dependent on mitochondrial fission

    PubMed Central

    Barvalia, Maunish; Wu, Yu Jun; Loja, Tomáš; Boon, Huat Bay; Lleonart, Matilde E.; Verma, Rama S; Krejci, Lumir; Lyakhovich, Alex

    2016-01-01

    Fanconi anemia (FA) is a rare genetic disorder associated with bone-marrow failure, genome instability and cancer predisposition. Recently, we and others have demonstrated dysfunctional mitochondria with morphological alterations in FA cells accompanied by high reactive oxygen species (ROS) levels. Mitochondrial morphology is regulated by continuous fusion and fission events and the misbalance between these two is often accompanied by autophagy. Here, we provide evidence of impaired autophagy in FA. We demonstrate that FA cells have increased number of autophagic (presumably mitophagic) events and accumulate dysfunctional mitochondria due to an impaired ability to degrade them. Moreover, mitochondrial fission accompanied by oxidative stress (OS) is a prerequisite condition for mitophagy in FA and blocking this pathway may release autophagic machinery to clear dysfunctional mitochondria. PMID:27517150

  16. Novel FANCI mutations in Fanconi anemia with VACTERL association.

    PubMed

    Savage, Sharon A; Ballew, Bari J; Giri, Neelam; Chandrasekharappa, Settara C; Ameziane, Najim; de Winter, Johan; Alter, Blanche P

    2016-02-01

    Fanconi anemia (FA) is an inherited bone marrow failure syndrome caused by mutations in DNA repair genes; some of these patients may have features of the VACTERL association. Autosomal recessive mutations in FANCI are a rare cause of FA. We identified FANCI mutations by next generation sequencing in three patients in our FA cohort among several whose mutated gene was unknown. Four of the six mutations are novel and all mutations are likely deleterious to protein function. There are now 16 reported cases of FA due to FANCI of whom 7 have at least 3 features of the VACTERL association (44%). This suggests that the VACTERL association in patients with FA may be seen in patients with FANCI mutations more often than previously recognized.

  17. What is the DNA repair defect underlying Fanconi anemia?

    PubMed Central

    Duxin, Julien P.; Walter, Johannes C.

    2015-01-01

    Fanconi anemia (FA) is a rare human genetic disease characterized by bone marrow failure, cancer predisposition, and genomic instability. It has been known for many years that FA patient-derived cells are exquisitely sensitive to DNA interstrand cross-linking agents such as cisplatin and mitomycin C. On this basis, it was widely assumed that failure to repair endogenous interstrand cross-links (ICLs) causes FA, although the endogenous mutagen that generates these lesions remained elusive. Recent genetic evidence now suggests that endogenous aldehydes are the driving force behind FA. Importantly, aldehydes cause a variety of DNA lesions, including ICLs and DNA protein cross-links (DPCs), re-kindling the debate about which DNA lesions cause FA. In this review, we discuss new developments in our understanding of DPC and ICL repair, and how these findings bear on the question of which DNA lesion underlies FA. PMID:26512453

  18. Towards a Molecular Understanding of the Fanconi Anemia Core Complex

    PubMed Central

    Hodson, Charlotte; Walden, Helen

    2012-01-01

    Fanconi Anemia (FA) is a genetic disorder characterized by the inability of patient cells to repair DNA damage caused by interstrand crosslinking agents. There are currently 14 verified FA genes, where mutation of any single gene prevents repair of DNA interstrand crosslinks (ICLs). The accumulation of ICL damage results in genome instability and patients having a high predisposition to cancers. The key event of the FA pathway is dependent on an eight-protein core complex (CC), required for the monoubiquitination of each member of the FANCD2-FANCI complex. Interestingly, the majority of patient mutations reside in the CC. The molecular mechanisms underlying the requirement for such a large complex to carry out a monoubiquitination event remain a mystery. This paper documents the extensive efforts of researchers so far to understand the molecular roles of the CC proteins with regard to its main function in the FA pathway, the monoubiquitination of FANCD2 and FANCI. PMID:22675617

  19. Use Massive Parallel Sequencing and Exome Capture Technology to Sequence the Exome of Fanconi Anemia Children and Their Patents

    ClinicalTrials.gov

    2013-11-21

    Fanconi Anemia; Autosomal or Sex Linked Recessive Genetic Disease; Bone Marrow Hematopoiesis Failure, Multiple Congenital Abnormalities, and Susceptibility to Neoplastic Diseases.; Hematopoiesis Maintainance.

  20. Role of Complement in Autoimmune Hemolytic Anemia.

    PubMed

    Berentsen, Sigbjørn

    2015-09-01

    The classification of autoimmune hemolytic anemias and the complement system are reviewed. In autoimmune hemolytic anemia of the warm antibody type, complement-mediated cell lysis is clinically relevant in a proportion of the patients but is hardly essential for hemolysis in most patients. Cold antibody-mediated autoimmune hemolytic anemias (primary cold agglutinin disease, secondary cold agglutinin syndrome and paroxysmal cold hemoglobinuria) are entirely complement-mediated disorders. In cold agglutinin disease, efficient therapies have been developed in order to target the pathogenic B-cell clone, but complement modulation remains promising in some clinical situations. No established therapy exists for secondary cold agglutinin syndrome and paroxysmal cold hemoglobinuria, and the possibility of therapeutic complement inhibition is interesting. Currently, complement modulation is not clinically documented in any autoimmune hemolytic anemia. The most relevant candidate drugs and possible target levels of action are discussed.

  1. Role of Complement in Autoimmune Hemolytic Anemia

    PubMed Central

    Berentsen, Sigbjørn

    2015-01-01

    Summary The classification of autoimmune hemolytic anemias and the complement system are reviewed. In autoimmune hemolytic anemia of the warm antibody type, complement-mediated cell lysis is clinically relevant in a proportion of the patients but is hardly essential for hemolysis in most patients. Cold antibody-mediated autoimmune hemolytic anemias (primary cold agglutinin disease, secondary cold agglutinin syndrome and paroxysmal cold hemoglobinuria) are entirely complement-mediated disorders. In cold agglutinin disease, efficient therapies have been developed in order to target the pathogenic B-cell clone, but complement modulation remains promising in some clinical situations. No established therapy exists for secondary cold agglutinin syndrome and paroxysmal cold hemoglobinuria, and the possibility of therapeutic complement inhibition is interesting. Currently, complement modulation is not clinically documented in any autoimmune hemolytic anemia. The most relevant candidate drugs and possible target levels of action are discussed. PMID:26696798

  2. A Biochemical Approach to Understanding the Fanconi Anemia Pathway-Regulated Nucleases in Genome Maintenance for Preventing Bone Marrow Failure and Cancer

    DTIC Science & Technology

    2014-04-01

    the Fanconi Anemia Pathway- Regulated Nucleases in Genome Maintenance for Preventing Bone Marrow Failure and Cancer PRINCIPAL INVESTIGATOR...GRANT NUMBER 4. TITLE AND SUBTITLE A Biochemical Approach to Understanding the Fanconi Anemia Pathway-Regulated Nucleases in Genome Maintenance for...Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Fanconi anemia is the most prevalent inherited BMF syndromes, caused by mutations in

  3. Diagnosis of Fanconi anemia in children with atypical clinical features: a primary study.

    PubMed

    Liu, Rong; Hu, Tao; Li, Jun-hui; Liang, Chao; Gu, Wei-yue; Shi, Xiao-dong; Wang, Hong-xing

    2013-12-01

    Fanconi anemia is a severe congenital disorder associated with mutations in a cluster of genes responsible for DNA repair. Arriving at an accurate and timely diagnosis can be difficult in cases of Fanconi anemia with atypical clinical features. It is very important to increase the rate of accurate diagnosis for such cases in a clinical setting. The purpose of this study is to explore the clinical diagnosis of Fanconi anemia in children with atypical clinical features. Six cases of Fanconi anemia with atypical clinical features were enrolled in the study, and their clinical features were recorded, their FANCA gene transcription was assessed by RT-PCR, and FANCA mutations and the ubiquitination of FANCD2 protein were analyzed using DNA sequencing and western blotting respectively. All six cases showed atypical clinical features including no apparent deformities, lack of response to immune therapy, and progressively increasing bone marrow failure. They also have significantly increased fetal hemoglobin, negative mitomycin-induced fracture test results, and carry a FANCA gene missense mutation. Single protein ubiquitination of FANCD2 was not observed in those patients. The combination of clinical features, FANCA pathogenic gene mutation genotype and the absence of FANCD2 protein ubiquitination are helpful in the accurate and timely diagnosis of Fanconi anemia in children.

  4. Targeted gene therapy and cell reprogramming in Fanconi anemia

    PubMed Central

    Rio, Paula; Baños, Rocio; Lombardo, Angelo; Quintana-Bustamante, Oscar; Alvarez, Lara; Garate, Zita; Genovese, Pietro; Almarza, Elena; Valeri, Antonio; Díez, Begoña; Navarro, Susana; Torres, Yaima; Trujillo, Juan P; Murillas, Rodolfo; Segovia, Jose C; Samper, Enrique; Surralles, Jordi; Gregory, Philip D; Holmes, Michael C; Naldini, Luigi; Bueren, Juan A

    2014-01-01

    Gene targeting is progressively becoming a realistic therapeutic alternative in clinics. It is unknown, however, whether this technology will be suitable for the treatment of DNA repair deficiency syndromes such as Fanconi anemia (FA), with defects in homology-directed DNA repair. In this study, we used zinc finger nucleases and integrase-defective lentiviral vectors to demonstrate for the first time that FANCA can be efficiently and specifically targeted into the AAVS1 safe harbor locus in fibroblasts from FA-A patients. Strikingly, up to 40% of FA fibroblasts showed gene targeting 42 days after gene editing. Given the low number of hematopoietic precursors in the bone marrow of FA patients, gene-edited FA fibroblasts were then reprogrammed and re-differentiated toward the hematopoietic lineage. Analyses of gene-edited FA-iPSCs confirmed the specific integration of FANCA in the AAVS1 locus in all tested clones. Moreover, the hematopoietic differentiation of these iPSCs efficiently generated disease-free hematopoietic progenitors. Taken together, our results demonstrate for the first time the feasibility of correcting the phenotype of a DNA repair deficiency syndrome using gene-targeting and cell reprogramming strategies. PMID:24859981

  5. Dysregulated Ca2+ Homeostasis in Fanconi anemia cells

    PubMed Central

    Usai, Cesare; Ravera, Silvia; Cuccarolo, Paola; Panfoli, Isabella; Dufour, Carlo; Cappelli, Enrico; Degan, Paolo

    2015-01-01

    Fanconi Anemia (FA) is a rare and complex inherited blood disorder associated with bone marrow failure and malignancies. Many alterations in FA physiology appear linked to red-ox unbalance including alterations in the morphology and structure of nuclei, intermediate filaments and mitochondria, defective respiration, reduced ATP production and altered ATP/AMP ratio. These defects are consistently associated with impaired oxygen metabolism indeed treatment with antioxidants N-acetylcysteine (NAC) and resveratrol (RV) does rescue FA physiology. Due to the importance of the intracellular calcium signaling and its key function in the control of intracellular functions we were interested to study calcium homeostasis in FA. We found that FANCA cells display a dramatically low intracellular calcium concentration ([Ca2+]i) in resting conditions. This condition affects cellular responses to stress. The flux of Ca2+ mobilized by H2O2 from internal stores is significantly lower in FANCA cells in comparison to controls. The low basal [Ca2+]i in FANCA appears to be an actively maintained process controlled by a finely tuned interplay between different intracellular Ca2+ stores. The defects associated with the altered Ca2+ homeostasis appear consistently overlapping those related to the unbalanced oxidative metabolism in FA cells underlining a contiguity between oxidative stress and calcium homeostasis. PMID:25627108

  6. Fanconi Anemia Proteins and Their Interacting Partners: A Molecular Puzzle

    PubMed Central

    Kaddar, Tagrid; Carreau, Madeleine

    2012-01-01

    In recent years, Fanconi anemia (FA) has been the subject of intense investigations, primarily in the DNA repair research field. Many discoveries have led to the notion of a canonical pathway, termed the FA pathway, where all FA proteins function sequentially in different protein complexes to repair DNA cross-link damages. Although a detailed architecture of this DNA cross-link repair pathway is emerging, the question of how a defective DNA cross-link repair process translates into the disease phenotype is unresolved. Other areas of research including oxidative metabolism, cell cycle progression, apoptosis, and transcriptional regulation have been studied in the context of FA, and some of these areas were investigated before the fervent enthusiasm in the DNA repair field. These other molecular mechanisms may also play an important role in the pathogenesis of this disease. In addition, several FA-interacting proteins have been identified with roles in these “other” nonrepair molecular functions. Thus, the goal of this paper is to revisit old ideas and to discuss protein-protein interactions related to other FA-related molecular functions to try to give the reader a wider perspective of the FA molecular puzzle. PMID:22737580

  7. The fanconi anemia pathway limits human papillomavirus replication.

    PubMed

    Hoskins, Elizabeth E; Morreale, Richard J; Werner, Stephen P; Higginbotham, Jennifer M; Laimins, Laimonis A; Lambert, Paul F; Brown, Darron R; Gillison, Maura L; Nuovo, Gerard J; Witte, David P; Kim, Mi-Ok; Davies, Stella M; Mehta, Parinda A; Butsch Kovacic, Melinda; Wikenheiser-Brokamp, Kathryn A; Wells, Susanne I

    2012-08-01

    High-risk human papillomaviruses (HPVs) deregulate epidermal differentiation and cause anogenital and head and neck squamous cell carcinomas (SCCs). The E7 gene is considered the predominant viral oncogene and drives proliferation and genome instability. While the implementation of routine screens has greatly reduced the incidence of cervical cancers which are almost exclusively HPV positive, the proportion of HPV-positive head and neck SCCs is on the rise. High levels of HPV oncogene expression and genome load are linked to disease progression, but genetic risk factors that regulate oncogene abundance and/or genome amplification remain poorly understood. Fanconi anemia (FA) is a genome instability syndrome characterized at least in part by extreme susceptibility to SCCs. FA results from mutations in one of 15 genes in the FA pathway, whose protein products assemble in the nucleus and play important roles in DNA damage repair. We report here that loss of FA pathway components FANCA and FANCD2 stimulates E7 protein accumulation in human keratinocytes and causes increased epithelial proliferation and basal cell layer expansion in the HPV-positive epidermis. Additionally, FANCD2 loss stimulates HPV genome amplification in differentiating cells, demonstrating that the intact FA pathway functions to restrict the HPV life cycle. These findings raise the possibility that FA genes suppress HPV infection and disease and suggest possible mechanism(s) for reported associations of HPV with an FA cohort in Brazil and for allelic variation of FA genes with HPV persistence in the general population.

  8. Biallelic inactivation of REV7 is associated with Fanconi anemia

    PubMed Central

    Masliah-Planchon, Julien; Clairmont, Connor; Rousseau, Alix; Ceccaldi, Raphael; Dubois d’Enghien, Catherine; Bluteau, Olivier; Cuccuini, Wendy; Gachet, Stéphanie; Peffault de Latour, Régis; Leblanc, Thierry; Socié, Gérard; Baruchel, André; Stoppa-Lyonnet, Dominique; D’Andrea, Alan D.

    2016-01-01

    Fanconi anemia (FA) is a recessive genetic disease characterized by congenital abnormalities, chromosome instability, progressive bone marrow failure (BMF), and a strong predisposition to cancer. Twenty FA genes have been identified, and the FANC proteins they encode cooperate in a common pathway that regulates DNA crosslink repair and replication fork stability. We identified a child with severe BMF who harbored biallelic inactivating mutations of the translesion DNA synthesis (TLS) gene REV7 (also known as MAD2L2), which encodes the mutant REV7 protein REV7-V85E. Patient-derived cells demonstrated an extended FA phenotype, which included increased chromosome breaks and G2/M accumulation upon exposure to DNA crosslinking agents, γH2AX and 53BP1 foci accumulation, and enhanced p53/p21 activation relative to cells derived from healthy patients. Expression of WT REV7 restored normal cellular and functional phenotypes in the patient’s cells, and CRISPR/Cas9 inactivation of REV7 in a non-FA human cell line produced an FA phenotype. Finally, silencing Rev7 in primary hematopoietic cells impaired progenitor function, suggesting that the DNA repair defect underlies the development of BMF in FA. Taken together, our genetic and functional analyses identified REV7 as a previously undescribed FA gene, which we term FANCV. PMID:27500492

  9. Alternative donor hematopoietic cell transplantation for Fanconi anemia.

    PubMed

    MacMillan, Margaret L; DeFor, Todd E; Young, Jo-Anne H; Dusenbery, Kathryn E; Blazar, Bruce R; Slungaard, Arne; Zierhut, Heather; Weisdorf, Daniel J; Wagner, John E

    2015-06-11

    Historically, alternative donor hematopoietic cell transplantation (HCT) for Fanconi anemia (FA) patients resulted in excessive morbidity and mortality. To improve outcomes, we made sequential changes to the HCT conditioning regimen. A total of 130 FA patients (median age, 9.0 years; range, 1-48) underwent alternative donor HCT at the University of Minnesota between 1995 and 2012. All patients received cyclophosphamide (CY), single fraction total body irradiation (TBI), and antithymocyte globulin (ATG) with or without fludarabine (FLU), followed by T-cell-depleted bone marrow or unmanipulated umbilical cord blood transplantation. The addition of FLU enhanced engraftment 3-fold. The incidence of grades 2-4 acute and chronic graft-versus-host disease was 20% and 10%, respectively. Severe toxicity was highest in patients >10 years of age or those with a history of opportunistic infections or transfusions before HCT. Mortality was lowest in patients without a history of opportunistic infection or transfusions and who received conditioning with TBI 300 cGy, CY, FLU, and ATG. These patients had a probability of survival of 94% at 5 years. Alternative donor HCT is now associated with excellent survival for patients without prior opportunistic infections or transfusions and should be considered for all FA patients after the onset of marrow failure. These studies were registered at http://www.clinicaltrials.gov as NCT00005898, NCT00167206, and NCT00352976.

  10. Alternative donor hematopoietic cell transplantation for Fanconi anemia

    PubMed Central

    DeFor, Todd E.; Young, Jo-Anne H.; Dusenbery, Kathryn E.; Blazar, Bruce R.; Slungaard, Arne; Zierhut, Heather; Weisdorf, Daniel J.; Wagner, John E.

    2015-01-01

    Historically, alternative donor hematopoietic cell transplantation (HCT) for Fanconi anemia (FA) patients resulted in excessive morbidity and mortality. To improve outcomes, we made sequential changes to the HCT conditioning regimen. A total of 130 FA patients (median age, 9.0 years; range, 1-48) underwent alternative donor HCT at the University of Minnesota between 1995 and 2012. All patients received cyclophosphamide (CY), single fraction total body irradiation (TBI), and antithymocyte globulin (ATG) with or without fludarabine (FLU), followed by T-cell–depleted bone marrow or unmanipulated umbilical cord blood transplantation. The addition of FLU enhanced engraftment 3-fold. The incidence of grades 2-4 acute and chronic graft-versus-host disease was 20% and 10%, respectively. Severe toxicity was highest in patients >10 years of age or those with a history of opportunistic infections or transfusions before HCT. Mortality was lowest in patients without a history of opportunistic infection or transfusions and who received conditioning with TBI 300 cGy, CY, FLU, and ATG. These patients had a probability of survival of 94% at 5 years. Alternative donor HCT is now associated with excellent survival for patients without prior opportunistic infections or transfusions and should be considered for all FA patients after the onset of marrow failure. These studies were registered at http://www.clinicaltrials.gov as NCT00005898, NCT00167206, and NCT00352976. PMID:25824692

  11. Comprehensive Analysis of Pathogenic Deletion Variants in Fanconi Anemia Genes

    PubMed Central

    Flynn, Elizabeth K.; Kamat, Aparna; Lach, Francis P.; Donovan, Frank X.; Kimble, Danielle C.; Narisu, Narisu; Sanborn, Erica; Boulad, Farid; Davies, Stella M.; Gillio, Alfred P.; Harris, Richard E.; MacMillan, Margaret L.; Wagner, John E.; Smogorzewska, Agata; Auerbach, Arleen D.; Ostrander, Elaine A.; Chandrasekharappa, Settara C.

    2014-01-01

    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 (arrayCGH), Single Nucleotide Polymorphism arrays (SNParrays) 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 Non-Allelic 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. PMID:25168418

  12. Molecular analysis of Fanconi anemia: the experience of the Bone Marrow Failure Study Group of the Italian Association of Pediatric Onco-Hematology

    PubMed Central

    De Rocco, Daniela; Bottega, Roberta; Cappelli, Enrico; Cavani, Simona; Criscuolo, Maria; Nicchia, Elena; Corsolini, Fabio; Greco, Chiara; Borriello, Adriana; Svahn, Johanna; Pillon, Marta; Mecucci, Cristina; Casazza, Gabriella; Verzegnassi, Federico; Cugno, Chiara; Locasciulli, Anna; Farruggia, Piero; Longoni, Daniela; Ramenghi, Ugo; Barberi, Walter; Tucci, Fabio; Perrotta, Silverio; Grammatico, Paola; Hanenberg, Helmut; Della Ragione, Fulvio; Dufour, Carlo; Savoia, Anna

    2014-01-01

    Fanconi anemia is an inherited disease characterized by congenital malformations, pancytopenia, cancer predisposition, and sensitivity to cross-linking agents. The molecular diagnosis of Fanconi anemia is relatively complex for several aspects including genetic heterogeneity with mutations in at least 16 different genes. In this paper, we report the mutations identified in 100 unrelated probands enrolled into the National Network of the Italian Association of Pediatric Hematoly and Oncology. In approximately half of these cases, mutational screening was carried out after retroviral complementation analyses or protein analysis. In the other half, the analysis was performed on the most frequently mutated genes or using a next generation sequencing approach. We identified 108 distinct variants of the FANCA, FANCG, FANCC, FANCD2, and FANCB genes in 85, 9, 3, 2, and 1 families, respectively. Despite the relatively high number of private mutations, 45 of which are novel Fanconi anemia alleles, 26% of the FANCA alleles are due to 5 distinct mutations. Most of the mutations are large genomic deletions and nonsense or frameshift mutations, although we identified a series of missense mutations, whose pathogenetic role was not always certain. The molecular diagnosis of Fanconi anemia is still a tiered procedure that requires identifying candidate genes to avoid useless sequencing. Introduction of next generation sequencing strategies will greatly improve the diagnostic process, allowing a rapid analysis of all the genes. PMID:24584348

  13. Structure of the FANCI-FANCD2 Complex: Insights into the Fanconi Anemia DNA Repair Pathway

    SciTech Connect

    Joo, Woo; Xu, Guozhou; Persky, Nicole S.; Smogorzewska, Agata; Rudge, Derek G.; Buzovetsky, Olga; Elledge, Stephen J.; Pavletich, Nikola P.

    2011-08-29

    Fanconi anemia is a cancer predisposition syndrome caused by defects in the repair of DNA interstrand cross-links (ICLs). Central to this pathway is the Fanconi anemia I-Fanconi anemia D2 (FANCI-FANCD2) (ID) complex, which is activated by DNA damage-induced phosphorylation and monoubiquitination. The 3.4 angstrom crystal structure of the {approx}300 kilodalton ID complex reveals that monoubiquitination and regulatory phosphorylation sites map to the I-D interface, suggesting that they occur on monomeric proteins or an opened-up complex and that they may serve to stabilize I-D heterodimerization. The 7.8 angstrom electron-density map of FANCI-DNA crystals and in vitro data show that each protein has binding sites for both single- and double-stranded DNA, suggesting that the ID complex recognizes DNA structures that result from the encounter of replication forks with an ICL.

  14. Structure of the FANCI-FANCD2 Complex: Insights into the Fanconi Anemia DNA Repair Pathway

    SciTech Connect

    W Joo; G Xu; n Persky; A Smogorzewska; D Rudge; O Buzovetsky; S Elledge; N Pavletich

    2011-12-31

    Fanconi anemia is a cancer predisposition syndrome caused by defects in the repair of DNA interstrand cross-links (ICLs). Central to this pathway is the Fanconi anemia I-Fanconi anemia D2 (FANCI-FANCD2) (ID) complex, which is activated by DNA damage-induced phosphorylation and monoubiquitination. The 3.4 angstrom crystal structure of the {approx}300 kilodalton ID complex reveals that monoubiquitination and regulatory phosphorylation sites map to the I-D interface, suggesting that they occur on monomeric proteins or an opened-up complex and that they may serve to stabilize I-D heterodimerization. The 7.8 angstrom electron-density map of FANCI-DNA crystals and in vitro data show that each protein has binding sites for both single- and double-stranded DNA, suggesting that the ID complex recognizes DNA structures that result from the encounter of replication forks with an ICL.

  15. Structure of the FANCI-FANCD2 complex: insights into the Fanconi anemia DNA repair pathway.

    PubMed

    Joo, Woo; Xu, Guozhou; Persky, Nicole S; Smogorzewska, Agata; Rudge, Derek G; Buzovetsky, Olga; Elledge, Stephen J; Pavletich, Nikola P

    2011-07-15

    Fanconi anemia is a cancer predisposition syndrome caused by defects in the repair of DNA interstrand cross-links (ICLs). Central to this pathway is the Fanconi anemia I-Fanconi anemia D2 (FANCI-FANCD2) (ID) complex, which is activated by DNA damage-induced phosphorylation and monoubiquitination. The 3.4 angstrom crystal structure of the ~300 kilodalton ID complex reveals that monoubiquitination and regulatory phosphorylation sites map to the I-D interface, suggesting that they occur on monomeric proteins or an opened-up complex and that they may serve to stabilize I-D heterodimerization. The 7.8 angstrom electron-density map of FANCI-DNA crystals and in vitro data show that each protein has binding sites for both single- and double-stranded DNA, suggesting that the ID complex recognizes DNA structures that result from the encounter of replication forks with an ICL.

  16. The Fanconi anemia pathway promotes replication-dependent DNA interstrand cross-link repair.

    PubMed

    Knipscheer, Puck; Räschle, Markus; Smogorzewska, Agata; Enoiu, Milica; Ho, The Vinh; Schärer, Orlando D; Elledge, Stephen J; Walter, Johannes C

    2009-12-18

    Fanconi anemia is a human cancer predisposition syndrome caused by mutations in 13 Fanc genes. The disorder is characterized by genomic instability and cellular hypersensitivity to chemicals that generate DNA interstrand cross-links (ICLs). A central event in the activation of the Fanconi anemia pathway is the mono-ubiquitylation of the FANCI-FANCD2 complex, but how this complex confers ICL resistance remains enigmatic. Using a cell-free system, we showed that FANCI-FANCD2 is required for replication-coupled ICL repair in S phase. Removal of FANCD2 from extracts inhibits both nucleolytic incisions near the ICL and translesion DNA synthesis past the lesion. Reversal of these defects requires ubiquitylated FANCI-FANCD2. Our results show that multiple steps of the essential S-phase ICL repair mechanism fail when the Fanconi anemia pathway is compromised.

  17. The structure of FANCL, the catalytic subunit of the Fanconi Anemia core complex

    PubMed Central

    Cole, Ambrose R.; Lewis, Laurence P.C.; Walden, Helen

    2010-01-01

    The Fanconi Anemia pathway is activated in response to DNA damage, leading to monoubiquitination of the substrates FANCI and FANCD2 by the Fanconi Anemia core complex. Here we report the crystal structure of FANCL, the catalytic subunit of the Fanconi Anemia core complex at 3.2 Å. The structure reveals an architecture that is fundamentally different from previous sequence-based predictions. The molecule is composed of an N-terminal E2-like fold, which we term the ELF domain, a novel double-RWD (DRWD) domain, and a C-terminal RING domain predicted to facilitate E2 binding. Binding assays demonstrate that the DRWD domain, but not the ELF domain, is responsible for substrate binding. PMID:20154706

  18. Identification of de Novo Fanconi Anemia in Younger Patients With Newly Diagnosed Acute Myeloid Leukemia

    ClinicalTrials.gov

    2016-05-13

    Childhood Acute Erythroleukemia (M6); Childhood Acute Megakaryocytic Leukemia (M7); Childhood Acute Minimally Differentiated Myeloid Leukemia (M0); Childhood Acute Monoblastic Leukemia (M5a); Childhood Acute Monocytic Leukemia (M5b); Childhood Acute Myeloblastic Leukemia With Maturation (M2); Childhood Acute Myeloblastic Leukemia Without Maturation (M1); Childhood Acute Myelomonocytic Leukemia (M4); Childhood Myelodysplastic Syndromes; Chronic Myelomonocytic Leukemia; de Novo Myelodysplastic Syndromes; Fanconi Anemia; Refractory Anemia; Refractory Anemia With Excess Blasts; Refractory Anemia With Excess Blasts in Transformation; Refractory Anemia With Ringed Sideroblasts; Secondary Myelodysplastic Syndromes; Untreated Childhood Acute Myeloid Leukemia and Other Myeloid Malignancies

  19. The Fanconi anemia DNA repair pathway: structural and functional insights into a complex disorder.

    PubMed

    Walden, Helen; Deans, Andrew J

    2014-01-01

    Mutations in any of at least sixteen FANC genes (FANCA-Q) cause Fanconi anemia, a disorder characterized by sensitivity to DNA interstrand crosslinking agents. The clinical features of cytopenia, developmental defects, and tumor predisposition are similar in each group, suggesting that the gene products participate in a common pathway. The Fanconi anemia DNA repair pathway consists of an anchor complex that recognizes damage caused by interstrand crosslinks, a multisubunit ubiquitin ligase that monoubiquitinates two substrates, and several downstream repair proteins including nucleases and homologous recombination enzymes. We review progress in the use of structural and biochemical approaches to understanding how each FANC protein functions in this pathway.

  20. Stem Cell Genetic Therapy for Fanconi Anemia - A New Hope.

    PubMed

    Hanenberg, Helmut; Roellecke, Katharina; Wiek, Constanze

    2017-01-09

    Fanconi anemia (FA) is a rare inherited DNA disorder clinically characterized by congenital malformations, progressive bone marrow failure, and cancer susceptibility. Due to a strong survival advantage of spontaneously corrected 'normal' hematopoietic stem cells (HSCs) in a few patients, FA is considered a model disorder for genetic correction of autologous stem cells, where genetically corrected stem cells and their progeny have a strong in vivo selective advantage, ultimately leading to normal hematopoiesis. Despite these apparently ideal circumstances, three HSC gene therapy trials with gammaretroviral vectors (stage I) designed to cure the hematological manifestation of FA failed completely to provide long-term clinical benefits for patients, predominantly due to the combination of insufficient gene transfer technologies and incompletely understood FA HSC pathobiology. Currently, FA gene therapy is in stage II where, based on an improved understanding of the cellular defects in FA HSCs, consequently adapted transduction protocols are being used in two phase I/II trials for in vitro genetic correction of FANCA-deficient hematopoietic stem cells. These results are eagerly awaited. However, independent from the outcome of these studies, technologies are already available that seem highly attractive for testing in FA. In stage III, this would ultimately include targeted in vivo correction of autologous HSCs by overexpression of nonintegrating lentiviral vectors with scaffold/matrix attachment region elements using specific envelopes as pseudotypes. Although currently still challenging, in a few years in vivo genome editing approaches will be readily available in stage IV, in which the delivery of the editing machinery/complex is targeted to the autologous FA HSCs by the nonintegrating lentiviral vectors established in stage III. Even low levels of corrected stem cells will then quickly repopulate the entire hematopoiesis of the patient. We therefore are sanguine

  1. Massively parallel sequencing, aCGH, and RNA-Seq technologies provide a comprehensive molecular diagnosis of Fanconi anemia.

    PubMed

    Chandrasekharappa, Settara C; Lach, Francis P; Kimble, Danielle C; Kamat, Aparna; Teer, Jamie K; Donovan, Frank X; Flynn, Elizabeth; Sen, Shurjo K; Thongthip, Supawat; Sanborn, Erica; Smogorzewska, Agata; Auerbach, Arleen D; Ostrander, Elaine A

    2013-05-30

    Current methods for detecting mutations in Fanconi anemia (FA)-suspected patients are inefficient and often miss mutations. We have applied recent advances in DNA sequencing and genomic capture to the diagnosis of FA. Specifically, we used custom molecular inversion probes or TruSeq-enrichment oligos to capture and sequence FA and related genes, including introns, from 27 samples from the International Fanconi Anemia Registry at The Rockefeller University. DNA sequencing was complemented with custom array comparative genomic hybridization (aCGH) and RNA sequencing (RNA-seq) analysis. aCGH identified deletions/duplications in 4 different FA genes. RNA-seq analysis revealed lack of allele specific expression associated with a deletion and splicing defects caused by missense, synonymous, and deep-in-intron variants. The combination of TruSeq-targeted capture, aCGH, and RNA-seq enabled us to identify the complementation group and biallelic germline mutations in all 27 families: FANCA (7), FANCB (3), FANCC (3), FANCD1 (1), FANCD2 (3), FANCF (2), FANCG (2), FANCI (1), FANCJ (2), and FANCL (3). FANCC mutations are often the cause of FA in patients of Ashkenazi Jewish (AJ) ancestry, and we identified 2 novel FANCC mutations in 2 patients of AJ ancestry. We describe here a strategy for efficient molecular diagnosis of FA.

  2. Finnish Fanconi anemia mutations and hereditary predisposition to breast and prostate cancer.

    PubMed

    Mantere, T; Haanpää, M; Hanenberg, H; Schleutker, J; Kallioniemi, A; Kähkönen, M; Parto, K; Avela, K; Aittomäki, K; von Koskull, H; Hartikainen, J M; Kosma, V-M; Laasanen, S-L; Mannermaa, A; Pylkäs, K; Winqvist, R

    2015-07-01

    Mutations in downstream Fanconi anemia (FA) pathway genes, BRCA2, PALB2, BRIP1 and RAD51C, explain part of the hereditary breast cancer susceptibility, but the contribution of other FA genes has remained questionable. Due to FA's rarity, the finding of recurrent deleterious FA mutations among breast cancer families is challenging. The use of founder populations, such as the Finns, could provide some advantage in this. Here, we have resolved complementation groups and causative mutations of five FA patients, representing the first mutation confirmed FA cases in Finland. These patients belonged to complementation groups FA-A (n = 3), FA-G (n = 1) and FA-I (n = 1). The prevalence of the six FA causing mutations was then studied in breast (n = 1840) and prostate (n = 565) cancer cohorts, and in matched controls (n = 1176 females, n = 469 males). All mutations were recurrent, but no significant association with cancer susceptibility was observed for any: the prevalence of FANCI c.2957_2969del and c.3041G>A mutations was even highest in healthy males (1.7%). This strengthens the exclusive role of downstream genes in cancer predisposition. From a clinical point of view, current results provide fundamental information of the mutations to be tested first in all suspected FA cases in Finland. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Increased radiosensitivity of a subpopulation of T-lymphocyte progenitors from patients with Fanconi's anemia

    SciTech Connect

    Knox, S.J.; Wilson, F.D.; Greenberg, B.R.; Shifrine, M.; Rosenblatt, L.S.; Reeves, J.D.; Misra, H.

    1981-06-01

    In vitro radiation survival of peripheral blood T lymphocytes was studied in 15 clinically normal adults and 4 patients with Fanconi's anemia. Tritiated thymidine incorporation in a whole blood lymphocyte stimulation test (LST) and a newly developed whole blood T-lymphocyte colony assay were used to measure lymphocyte blastogenesis and colony formation in response to phytohemagglutinin (PHA) or concanavalin-A (Con-A) stimulation. Lymphocyte colony formation was found to be consistently more sensitive than the LST for detection of low-level radiation effects using both normal cells and lymphocytes from Fanconi's anemia patients. Lymphocytes from patients with Fanconi's anemia were significantly more sensitive to in vitro x irradiation than lymphocytes from clinically normal individuals as measured by their ability to divide when stimulated by PHA in the LST and colony formation assay. No significant difference in the radiosensitivity of the Con-A response was observed between the two groups. The PHA-responsive T-lymphocyte subpopulation in Fanconi's anemia patients appears to be intrinsically defective. The nature of this defect, significance in the disease process, and relevancy of these findings to the establishment of radiation protection standards are discussed.

  4. Increased radiosensitivity of a subpopulation ot T-lymphocyte progenitors from patients with Fanconi's anemia

    SciTech Connect

    Knox, S.J.; Wilson, F.D.; Greenberg, B.R.; Shifrine, M.; Rosenblatt, L.S.; Reeves, J.D.; Misra, H.

    1981-06-01

    In vitro radiation survival of peripheral blood T lymphocytes was studied in 15 clinically normal adults and 4 patients with Fanconi's anemia. Tritiated thymidine incorporation in a whole blood lymphocyte stimulation test (LST) and a newly developed whole blood T-lymphocyte colony assay were used to measure lymphocyte blastogenesis and colony formation in response to phytohemagglutinin (PHA) or concanavalin-A (Con-A) stimulation. Lymphocyte colony formation was found to be consistently more sensitive than the LST for detection of low-level radiation effects using both normal cells and lymphocytes from Fanconi's anemia patients. Lymphocytes from patients with Fanconi's anemia were significantly more sensitive to in vitro x-irradiation than lymphocytes from clinically normal individuals as measured by their ability to divide when stimulated by PHA in the LST (patients, D37 . 198 R; normals, D37 . 309 R, p . 0.057) and colony formation assay (patients, D37 . 53 R; normals, D37 . 109 R, p . 0.016). No significant difference in the radiosensitivity of the Con-A response was observed between the two groups. The PHA-responsive T-lymphocyte subpopulation in Fanconi's anemia patients appears to be intrinsically defective. The nature of this defect, significance in the disease process, and relevancy of these findings to the establishment of radiation protection standards are discussed.

  5. De Novo Chromosome Copy Number Variation in Fanconi Anemia-Associated Hematopoietic Defects

    DTIC Science & Technology

    2014-08-01

    Laboratory used two cell types for these experimental approaches: 090 hTERT and HCT116. 090 hTERT are a normal hTERT-immortalized skin fibroblast...Adam, Z., Rani, R., Zhang, X. and Pang, Q. (2008) Oxidative stress in Fanconi anemia hematopoiesis and disease progression. Antioxid Redox Signal, 10

  6. Phenotypic consequences in black South African Fanconi anemia patients homozygous for a founder mutation.

    PubMed

    Feben, Candice; Kromberg, Jennifer; Wainwright, Rosalind; Stones, David; Sutton, Chris; Poole, Janet; Haw, Tabitha; Krause, Amanda

    2014-05-01

    Fanconi anemia is a genotypically and phenotypically heterogeneous condition, characterized microscopically by chromosomal instability and breakage. Affected individuals manifest growth restriction and congenital physical abnormalities; most progress to hematological disease including bone marrow aplasia. Black South African Fanconi anemia patients share a common causative founder mutation in the Fanconi G gene in 80% of cases (637_643delTACCGCC). The aim of this study was to investigate the genotype-physical phenotype correlation in a cohort of individuals homozygous for this mutation. Thirty-five black patients were recruited from tertiary level hematology/oncology clinics in South Africa. Participants were subjected to a comprehensive clinical examination, documenting growth, congenital anomalies, and phenotypic variability. Descriptive statistical analysis showed significant growth abnormalities in many patients and a high frequency (97%) of skin pigmentary anomalies. Subtle anomalies of the eyes, ears, and hands occurred frequently (≥70%). Apart from malformations of the kidney (in 37%) and gastrointestinal tract (in 8.5%), congenital anomalies of other systems including the cardiovascular and central nervous systems, genitalia, and vertebrae were infrequent (<5%). The diagnosis of Fanconi anemia in black South African patients before the onset of hematological symptoms remains a clinical challenge, with the physical phenotype unlikely to be recognized by those without dysmorphology expertise.

  7. The Fanconi anemia ortholog FANCM ensures ordered homologous recombination in both somatic and meiotic cells in Arabidopsis.

    PubMed

    Knoll, Alexander; Higgins, James D; Seeliger, Katharina; Reha, Sarah J; Dangel, Natalie J; Bauknecht, Markus; Schröpfer, Susan; Franklin, F Christopher H; Puchta, Holger

    2012-04-01

    The human hereditary disease Fanconi anemia leads to severe symptoms, including developmental defects and breakdown of the hematopoietic system. It is caused by single mutations in the FANC genes, one of which encodes the DNA translocase FANCM (for Fanconi anemia complementation group M), which is required for the repair of DNA interstrand cross-links to ensure replication progression. We identified a homolog of FANCM in Arabidopsis thaliana that is not directly involved in the repair of DNA lesions but suppresses spontaneous somatic homologous recombination via a RecQ helicase (At-RECQ4A)-independent pathway. In addition, it is required for double-strand break-induced homologous recombination. The fertility of At-fancm mutant plants is compromised. Evidence suggests that during meiosis At-FANCM acts as antirecombinase to suppress ectopic recombination-dependent chromosome interactions, but this activity is antagonized by the ZMM pathway to enable the formation of interference-sensitive crossovers and chromosome synapsis. Surprisingly, mutation of At-FANCM overcomes the sterility phenotype of an At-MutS homolog4 mutant by apparently rescuing a proportion of crossover-designated recombination intermediates via a route that is likely At-MMS and UV sensitive81 dependent. However, this is insufficient to ensure the formation of an obligate crossover. Thus, At-FANCM is not only a safeguard for genome stability in somatic cells but is an important factor in the control of meiotic crossover formation.

  8. Identification of the Fanconi anemia (FANC) I protein, a monoubiquitinated FANCD2 paralog required for crosslink repair

    PubMed Central

    Smogorzewska, Agata; Matsuoka, Shuhei; Vinciguerra, Patrizia; McDonald, E. Robert; Hurov, Kristen E.; Luo, Ji; Ballif, Bryan A.; Gygi, Steven P.; Hofmann, Kay; D’Andrea, Alan D.; Elledge, Stephen J.

    2007-01-01

    Summary Fanconi anemia (FA) is a developmental and cancer-predisposition syndrome caused by mutations in genes controlling crosslink repair. Several FA proteins form a ubiquitin ligase that controls monoubiquitination of the FANCD2 protein in an ATR-dependent manner. Here we describe a new FA protein FANCI, identified as a ATM/ATR kinase substrate required for resistance to mitomycin C. FANCI shares sequence similarity with FANCD2, likely evolving from a common ancestral gene. The FANCI protein associates with FANCD2 and together, as the FANCI-FANCD2 (ID) complex, load onto chromatin in response to DNA damage. Like FANCD2, FANCI is monoubiquitinated and unexpectedly, ubiquitination of each protein is important for the maintenance of ubiquitin on the other, indicating the existence of a dual ubiquitin locking mechanism required for the ability of the ID complex to function. Mutation in FANCI is responsible for loss of a functional FA pathway in a patient with Fanconi anemia complementation group I. PMID:17412408

  9. FANCM of the Fanconi anemia core complex is required for both monoubiquitination and DNA repair.

    PubMed

    Xue, Yutong; Li, Yongjiang; Guo, Rong; Ling, Chen; Wang, Weidong

    2008-06-01

    In response to DNA damage, the Fanconi anemia (FA) core complex functions as a signaling machine for monoubiquitination of FANCD2 and FANCI. It remains unclear whether this complex can also participate in subsequent DNA repair. We have shown previously that the FANCM constituent of the complex contains a highly conserved helicase domain and an associated ATP-dependent DNA translocase activity. Here we show that FANCM also possesses an ATP-independent binding activity and an ATP-dependent bi-directional branch-point translocation activity on a synthetic four-way junction DNA, which mimics intermediates generated during homologous recombination or at stalled replication forks. Using an siRNA-based complementation system, we found that the ATP-dependent activities of FANCM are required for cellular resistance to a DNA-crosslinking drug, mitomycin C, but not for the monoubiquitination of FANCD2 and FANCI. In contrast, monoubiquitination requires the entire helicase domain of FANCM, which has both ATP dependent and independent activities. These data are consistent with participation of FANCM and its associated FA core complex in the FA pathway at both signaling through monoubiquitination and the ensuing DNA repair.

  10. Architecture and DNA Recognition Elements of the Fanconi Anemia FANCM-FAAP24 Complex

    PubMed Central

    Coulthard, Rachel; Deans, Andrew J.; Swuec, Paolo; Bowles, Maureen; Costa, Alessandro; West, Stephen C.; McDonald, Neil Q.

    2013-01-01

    Summary Fanconi anemia (FA) is a disorder associated with a failure in DNA repair. FANCM (defective in FA complementation group M) and its partner FAAP24 target other FA proteins to sites of DNA damage. FANCM-FAAP24 is related to XPF/MUS81 endonucleases but lacks endonucleolytic activity. We report a structure of an FANCM C-terminal fragment (FANCMCTD) bound to FAAP24 and DNA. This S-shaped structure reveals the FANCM (HhH)2 domain is buried, whereas the FAAP24 (HhH)2 domain engages DNA. We identify a second DNA contact and a metal center within the FANCM pseudo-nuclease domain and demonstrate that mutations in either region impair double-stranded DNA binding in vitro and FANCM-FAAP24 function in vivo. We show the FANCM translocase domain lies in proximity to FANCMCTD by electron microscopy and that binding fork DNA structures stimulate its ATPase activity. This suggests a tracking model for FANCM-FAAP24 until an encounter with a stalled replication fork triggers ATPase-mediated fork remodeling. PMID:23932590

  11. Modeling Fanconi Anemia pathogenesis and therapeutics using integration-free patient-derived iPSCs

    PubMed Central

    Montserrat, Nuria; Tarantino, Carolina; Gu, Ying; Yi, Fei; Xu, Xiuling; Zhang, Weiqi; Ruiz, Sergio; Plongthongkum, Nongluk; Zhang, Kun; Masuda, Shigeo; Nivet, Emmanuel; Tsunekawa, Yuji; Soligalla, Rupa Devi; Goebl, April; Aizawa, Emi; Kim, Na Young; Kim, Jessica; Dubova, Ilir; Li, Ying; Ren, Ruotong; Benner, Chris; del Sol, Antonio; Bueren, Juan; Trujillo, Juan Pablo; Surralles, Jordi; Cappelli, Enrico; Dufour, Carlo; Esteban, Concepcion Rodriguez; Belmonte, Juan Carlos Izpisua

    2014-01-01

    Fanconi Anemia (FA) is a recessive disorder characterized by genomic instability, congenital abnormalities, cancer predisposition and bone marrow failure. However, the pathogenesis of FA is not fully understood partly due to the limitations of current disease models. Here, we derive integration-free induced pluripotent stem cells (iPSCs) from an FA patient without genetic complementation and report in situ gene correction in FA-iPSCs as well as the generation of isogenic FANCA deficient human embryonic stem cell (ESC) lines. FA cellular phenotypes are recapitulated in iPSCs/ESCs and their adult stem/progenitor cell derivatives. By using isogenic pathogenic mutation-free controls as well as cellular and genomic tools, our model serves to facilitate the discovery of novel disease features. We validate our model as a drug-screening platform by identifying several compounds that improve hematopoietic differentiation of FA-iPSCs. These compounds are also able to rescue the hematopoietic phenotype of FA-patient bone marrow cells. PMID:24999918

  12. Direct inhibition of TNF-α promoter activity by Fanconi anemia protein FANCD2.

    PubMed

    Matsushita, Nobuko; Endo, Yujiro; Sato, Koichi; Kurumizaka, Hitoshi; Yamashita, Takayuki; Takata, Minoru; Yanagi, Shigeru

    2011-01-01

    Fanconi anemia (FA), an inherited disease, is associated with progressive bone marrow failure, predisposition to cancer, and genomic instability. Genes corresponding to 15 identified FA complementation groups have been cloned, and each gene product functions in the response to DNA damage induced by cross-linking agents and/or in protection against genome instability. Interestingly, overproduction of inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and aberrant activation of NF-κB-dependent transcriptional activity have been observed in FA cells. Here we demonstrated that FANCD2 protein inhibits NF-κB activity in its monoubiquitination-dependent manner. Furthermore, we detected a specific association between FANCD2 and an NF-κB consensus element in the TNF-α promoter by electrophoretic mobility shift assays (EMSA) and chromatin immunoprecipitation (ChIP) assay. Therefore, we propose FANCD2 deficiency promotes transcriptional activity of the TNF-α promoter and induces overproduction of TNF-which then sustains prolonged inflammatory responses. These results also suggest that artificial modulation of TNFα production could be a promising therapeutic approach to FA.

  13. Direct Inhibition of TNF-α Promoter Activity by Fanconi Anemia Protein FANCD2

    PubMed Central

    Matsushita, Nobuko; Endo, Yujiro; Sato, Koichi; Kurumizaka, Hitoshi; Yamashita, Takayuki; Takata, Minoru; Yanagi, Shigeru

    2011-01-01

    Fanconi anemia (FA), an inherited disease, is associated with progressive bone marrow failure, predisposition to cancer, and genomic instability. Genes corresponding to 15 identified FA complementation groups have been cloned, and each gene product functions in the response to DNA damage induced by cross-linking agents and/or in protection against genome instability. Interestingly, overproduction of inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and aberrant activation of NF-κB-dependent transcriptional activity have been observed in FA cells. Here we demonstrated that FANCD2 protein inhibits NF-κB activity in its monoubiquitination-dependent manner. Furthermore, we detected a specific association between FANCD2 and an NF-κB consensus element in the TNF-α promoter by electrophoretic mobility shift assays (EMSA) and chromatin immunoprecipitation (ChIP) assay. Therefore, we propose FANCD2 deficiency promotes transcriptional activity of the TNF-α promoter and induces overproduction of TNF-which then sustains prolonged inflammatory responses. These results also suggest that artificial modulation of TNFα production could be a promising therapeutic approach to FA. PMID:21912593

  14. The genomic organization of the Fanconi anemia group A (FAA) gene

    SciTech Connect

    Ianzano, L.; Centra, M.; Savino, M.

    1997-05-01

    Fanconi anemia (FA) is a genetically heterogeneous disease involving at least five genes on the basis of complementation analysis (FAA to FAE). The FAA gene has been recently isolated by two independent approaches, positional and functional cloning. In the present study we describe the genomic structure of the FAA gene. The gene contains 43 exons spanning approximately 80 kb as determined by the alignment of four cosmids and the fine localization of the first and the last exons in restriction fragments of these clones. Exons range from 34 to 188 bp. All but three of the splice sites were consistent with the ag-gt rule. We also describe three alternative splicing events in cDNA clones that result in the loss of exon 37, a 23-bp deletion at the 5{prime} end of exon 41. Sequence analysis of the 5{prime} region upstream of the putative transcription start site showed no obvious TATA and CAAT boxes, but did show a GC-rich region, typical of housekeeping genes. Knowledge of the structure of the FAA gene will provide an invaluable resource for the discovery of mutations in the gene that accounts for about 60-66% of FA patients. 24 refs., 3 figs., 1 tab.

  15. Oxidative stress-related mechanisms are associated with xenobiotics exerting excess toxicity to Fanconi anemia cells.

    PubMed Central

    Pagano, Giovanni; Manini, Paola; Bagchi, Debasis

    2003-01-01

    An extensive body of evidence has demonstrated the sensitivity of Fanconi anemia (FA) cells to redox-active xenobiotics, such as mitomycin C, diepoxybutane, cisplatin, and 8-methoxypsoralen plus ultraviolet irradiation, with toxicity mechanisms that are consistent with a deficiency of FA cells in coping with oxidative stress. A recent study has reported on excess sensitivity of FA complementation A group cells to chromium VI [Cr(VI)] toxicity, by postulating that a deficiency in Cr-DNA cross-link removal by FA cells and formation of Cr(VI)-associated cross-links may be the mechanism of Cr(VI)-induced cytotoxicity. However, the report failed to demonstrate any enhanced Cr uptake or, especially, any increase in Cr-DNA adducts. Thus, well-established findings on Cr(VI)-induced oxidative stress may explain excess sensitivity of FA cells to Cr(VI) in terms of its inability to cope with the Cr(VI)-induced prooxidant state. PMID:14594617

  16. Perspective: A defined role for multiple Fanconi anemia gene products in DNA damage associated ubiquitination.

    PubMed

    Tan, Winnie; Deans, Andrew J

    2017-03-15

    Fanconi anemia (FA) is an inherited blood disorder that causes bone marrow failure and high predisposition to cancers. The FA pathway guards the cells' genome stability by orchestrating the repair of interstrand crosslink during S phase of the cell cycle, preventing chromosomal instability that is a key event in the bone marrow failure syndrome. Central to FA pathway is loss of mono-ubiquitinated forms of the Fanconi proteins FANCI and FANCD2, a process that is normally mediated by a "core complex" of seven other Fanconi proteins. Each protein when mutated can cause FA. The FA core complex catalyzed reaction is critical for signalling DNA crosslink damage, such as that induced by chemotherapies. We present a perspective on the current understanding of FANCI and FANCD2 monoubiquitination-mediated DNA repair. Our recent biochemical reconstitution of the monoubiquitination (and deubiquitination) reactions creates a paradigm for understanding FA. Further biochemical analysis will create new opportunities to address the leukemic phenotype of FA patients.

  17. Renal artery stenosis: An unusual etiology of hypertensive encephalopathy in a child with fanconi anemia.

    PubMed

    Purkait, Radheshyam; Mukherji, Aritra; Datta, Sucharita; Bhadra, Ramchandra

    2015-01-01

    A 9-year-old girl, diagnosed case of Fanconi anemia, presented with generalized convulsion with altered sensorium. She had fever, severe pallor, sinus tachycardia, blood pressure of 180/120 mmHg in both upper and lower limb, pan-systolic murmur of grade 2/6, abdominal bruit and bilateral papilledema. A provisional diagnosis of hypertensive encephalopathy was made and managed with continuous labetalol infusion. Detailed evaluation including magnetic resonance angiography of renal artery detected underlying atrophic and non-functioning right kidney secondary to severe renal artery stenosis on the same side. She was started with multiple antihypertensives, but her blood pressure was maintained poorly. Later on, she underwent rightsided nephrectomy. Following surgery, she was doing well and maintaining normal blood pressure without any antihypertensives. Our child is the second reported case of Fanconi anemia associated with renal artery stenosis presenting with hypertensive encephalopathy.

  18. FANCI phosphorylation functions as a molecular switch to turn on the Fanconi anemia pathway.

    PubMed

    Ishiai, Masamichi; Kitao, Hiroyuki; Smogorzewska, Agata; Tomida, Junya; Kinomura, Aiko; Uchida, Emi; Saberi, Alihossein; Kinoshita, Eiji; Kinoshita-Kikuta, Emiko; Koike, Tohru; Tashiro, Satoshi; Elledge, Stephen J; Takata, Minoru

    2008-11-01

    In response to DNA damage or replication fork stress, the Fanconi anemia pathway is activated, leading to monoubiquitination of FANCD2 and FANCI and their colocalization in foci. Here we show that, in the chicken DT40 cell system, multiple alanine-substitution mutations in six conserved and clustered Ser/Thr-Gln motifs of FANCI largely abrogate monoubiquitination and focus formation of both FANCI and FANCD2, resulting in loss of DNA repair function. Conversely, FANCI carrying phosphomimic mutations on the same six residues induces constitutive monoubiquitination and focus formation of FANCI and FANCD2, and protects against cell killing and chromosome breakage by DNA interstrand cross-linking agents. We propose that the multiple phosphorylation of FANCI serves as a molecular switch in activation of the Fanconi anemia pathway. Mutational analysis of putative phosphorylation sites in human FANCI indicates that this switch is evolutionarily conserved.

  19. Dental Perspective of Rare Disease of Fanconi Anemia: Case Report with Review

    PubMed Central

    Goswami, Mridula; Bhushan, Urvashi; Goswami, Manoj

    2016-01-01

    Fanconi anemia is an extremely rare genetic disease characterized by chromosomal instability that induces congenital alterations in individuals. It causes defective hemopoiesis ultimately leading to bone marrow failure. Patients are susceptible to recurrent infections and increased risk of hemorrhage, as well as delayed and poor wound healing. Herein, we report a case of Fanconi anemia in which various classical signs of the disease were present. The patient has been on regular follow-up since three and a half years for management of dental problems. The different aspects of this rare disorder are discussed with emphasis on oral manifestations and their influence on the general health of affected patients. Due to an increased susceptibility to developing cancers in this specific population, it is imperative for pediatric dentists to know about the common oral manifestations and potentially cancerous lesions, in order to make an early diagnosis and provide comprehensive care and maintenance of oral health in affected individuals. PMID:27013901

  20. BRCA1 Regulation of Fanconi Anemia Proteins in DNA Damage Repair

    DTIC Science & Technology

    2006-05-01

    Fanconi Anemia (FA) is a rare autosomal recessive disorder. It has been shown that BRCA1 regulates one of FA proteins, called FANCD2 , by a process...that BRCA1 ubiquitination of FANCD2 is affected by association with the FANCA protein complex and by association with DNA damage when embedded in...chromatin. Specific aims are that (1) does BRCA1 monoubiquitinate FANCD2 in vivo using purified ubiquitination factors? (2) Do embedding FA proteins in

  1. BRCA1 Regulation of Fanconi Anemia Proteins in DNA Damage Repair

    DTIC Science & Technology

    2005-05-01

    damage. Fanconi Anemia (FA) is a rare autosomal recessive disorder. It has been shown that BRCA1 regulates one of FA proteins, called FANCD2 , by a...hypothesize that BRCAI ubiquitination of FANCD2 is affected by association with the FANdA protein complex and by association with DNA damage when embedded in...chromatin. Specific aims are that (1) does BRCA1 monoubiquitinate FANCD2 in vivo using purified ubiquitination factors? (2) Do embedding FA proteins

  2. FANCI is a second monoubiquitinated member of the Fanconi anemia pathway.

    PubMed

    Sims, Ashley E; Spiteri, Elizabeth; Sims, Robert J; Arita, Adriana G; Lach, Francis P; Landers, Thomas; Wurm, Melanie; Freund, Marcel; Neveling, Kornelia; Hanenberg, Helmut; Auerbach, Arleen D; Huang, Tony T

    2007-06-01

    Activation of the Fanconi anemia (FA) DNA damage-response pathway results in the monoubiquitination of FANCD2, which is regulated by the nuclear FA core ubiquitin ligase complex. A FANCD2 protein sequence-based homology search facilitated the discovery of FANCI, a second monoubiquitinated component of the FA pathway. Biallelic mutations in the gene coding for this protein were found in cells from four FA patients, including an FA-I reference cell line.

  3. Targeted disruption of the murine Facc gene: Towards the establishment of a mouse model for Fanconi anemia

    SciTech Connect

    Chen, M.; Auerbach, W.; Buchwald, M.

    1994-09-01

    Fanconi anemia (FA) is an autosomal recessive disease characterized by bone marrow failure, congenital malformations and predisposition to malignancies. The gene responsible for the defect in FA group C has been cloned and designated the Fanconi Anemia Complementation Group C gene (FACC). A murine cDNA for this gene (Facc) was also cloned. Here we report our progress in the establishment of a mouse model for FA. The mouse Facc cDNA was used as probe to screen a genomic library of mouse strain 129. More than twenty positive clones were isolated. Three of them were mapped and found to be overlapping clones, encompassing the genomic region from exon 8 to the end of the 3{prime} UTR of the mouse cDNA. A targeting vector was constructed using the most 5{prime} mouse genomic sequence available. The end result of the homologous recombination is that exon 8 is deleted and the neo gene is inserted. The last exon, exon 14, is essential for the complementing function of the FACC gene product; the disruption in the middle of the murine Facc gene should render this locus biologically inactive. This targeting vector was linearized and electroporated into R1 embryonic stem (ES) cells which were derived from the 129 mouse. Of 102 clones screened, 19 positive cell lines were identified. Four targeted cell lines have been used to produce chimeric mice. 129-derived ES cells were aggregated ex vivo into the morulas derived from CD1 mice and then implanted into foster mothers. 22 chimeras have been obtained. Moderately and strongly chimeric mice have been bred to test for germline transmission. Progeny with the expected coat color derived from 2 chimeras are currently being examined to confirm transmission of the targeted allele.

  4. Whole exome sequencing reveals concomitant mutations of multiple FA genes in individual Fanconi anemia patients

    PubMed Central

    2014-01-01

    Background Fanconi anemia (FA) is a rare inherited genetic syndrome with highly variable clinical manifestations. Fifteen genetic subtypes of FA have been identified. Traditional complementation tests for grouping studies have been used generally in FA patients and in stepwise methods to identify the FA type, which can result in incomplete genetic information from FA patients. Methods We diagnosed five pediatric patients with FA based on clinical manifestations, and we performed exome sequencing of peripheral blood specimens from these patients and their family members. The related sequencing data were then analyzed by bioinformatics, and the FANC gene mutations identified by exome sequencing were confirmed by PCR re-sequencing. Results Homozygous and compound heterozygous mutations of FANC genes were identified in all of the patients. The FA subtypes of the patients included FANCA, FANCM and FANCD2. Interestingly, four FA patients harbored multiple mutations in at least two FA genes, and some of these mutations have not been previously reported. These patients’ clinical manifestations were vastly different from each other, as were their treatment responses to androstanazol and prednisone. This finding suggests that heterozygous mutation(s) in FA genes could also have diverse biological and/or pathophysiological effects on FA patients or FA gene carriers. Interestingly, we were not able to identify de novo mutations in the genes implicated in DNA repair pathways when the sequencing data of patients were compared with those of their parents. Conclusions Our results indicate that Chinese FA patients and carriers might have higher and more complex mutation rates in FANC genes than have been conventionally recognized. Testing of the fifteen FANC genes in FA patients and their family members should be a regular clinical practice to determine the optimal care for the individual patient, to counsel the family and to obtain a better understanding of FA pathophysiology

  5. Mutations of the Fanconi anemia group A gene (FAA) in Italian patients.

    PubMed Central

    Savino, M; Ianzano, L; Strippoli, P; Ramenghi, U; Arslanian, A; Bagnara, G P; Joenje, H; Zelante, L; Savoia, A

    1997-01-01

    Fanconi anemia (FA) is an autosomal recessive disease characterized by progressive pancytopenia, congenital malformations, and predisposition to acute myeloid leukemia. At least five complementation groups (FA-A-FA-E) have been identified. The relative prevalence of FA-A has been estimated at an average of approximately 65% but may widely vary according to ethnic background. In Italy, 11 of 12 patients analyzed by cell-fusion studies were assigned to group FA-A, suggesting an unusually high relative prevalence of this FA subtype in patients of Italian ancestry. We have screened the 43 exons of the FAA gene and their flanking intronic sequences in 38 Italian FA patients, using RNA-SSCP. Ten different mutations were detected: three nonsense and one missense substitutions, four putative splice mutations, an insertion, and a duplication. Most of the mutations are expected to cause a premature termination of the FAA protein at various sites throughout the molecule. Four protein variants were also found, three of which were polymorphisms. The missense mutation D1359Y, not found in chromosomes from healthy unrelated individuals, was responsible for a local alteration of hydrophobicity in the FAA protein, and it was likely to be pathogenic. Thus, the mutations so far encountered in the FAA gene are essentially all different. Since screening based on the analysis of single exons by genomic DNA amplification apparently detects only a minority of the mutations, methods designed to detect alterations in the genomic structure of the gene or in the FAA polypeptide may be helpful in the identification of FAA mutations. Images Figure 1 Figure 2 Figure 3 PMID:9399890

  6. Primary Ovarian Insufficiency Induced by Fanconi Anemia E Mutation in a Mouse Model.

    PubMed

    Fu, Chun; Begum, Khurshida; Overbeek, Paul A

    2016-01-01

    In most cases of primary ovarian insufficiency (POI), the cause of the depletion of ovarian follicles is unknown. Fanconi anemia (FA) proteins are known to play important roles in follicular development. Using random insertional mutagenesis with a lentiviral transgene, we identified a family with reduced fertility in the homozygous transgenic mice. We identified the integration site and found that the lentivirus had integrated into intron 8 of the Fanconi E gene (Fance). By RT-PCR and in situ hybridization, we found that Fance transcript levels were significantly reduced. The Fance homozygous mutant mice were assayed for changes in ovarian development, follicle numbers and estrous cycle. Ovarian dysplasias and a severe lack of follicles were seen in the mutant mice. In addition, the estrous cycle was disrupted in adult females. Our results suggest that POI has been induced by the Fance mutation in this new mouse model.

  7. Primary Ovarian Insufficiency Induced by Fanconi Anemia E Mutation in a Mouse Model

    PubMed Central

    Fu, Chun; Begum, Khurshida; Overbeek, Paul A.

    2016-01-01

    In most cases of primary ovarian insufficiency (POI), the cause of the depletion of ovarian follicles is unknown. Fanconi anemia (FA) proteins are known to play important roles in follicular development. Using random insertional mutagenesis with a lentiviral transgene, we identified a family with reduced fertility in the homozygous transgenic mice. We identified the integration site and found that the lentivirus had integrated into intron 8 of the Fanconi E gene (Fance). By RT-PCR and in situ hybridization, we found that Fance transcript levels were significantly reduced. The Fance homozygous mutant mice were assayed for changes in ovarian development, follicle numbers and estrous cycle. Ovarian dysplasias and a severe lack of follicles were seen in the mutant mice. In addition, the estrous cycle was disrupted in adult females. Our results suggest that POI has been induced by the Fance mutation in this new mouse model. PMID:26939056

  8. Twenty years of the Italian Fanconi Anemia Registry: where we stand and what remains to be learned

    PubMed Central

    Risitano, Antonio M.; Marotta, Serena; Calzone, Rita; Grimaldi, Francesco; Zatterale, Adriana

    2016-01-01

    The natural history of Fanconi anemia remains hard to establish because of its rarity and its heterogeneous clinical presentation; since 1994, the Italian Fanconi Anemia Registry has collected clinical, epidemiological and genetic data of Italian Fanconi Anemia patients. This registry includes 180 patients with a confirmed diagnosis of Fanconi anemia who have either been enrolled prospectively, at diagnosis, or later on. After enrollment, follow-up data were periodically collected to assess the clinical course, possible complications and long-term survival; the median follow up was 15.6 years. The main goal of the study was to describe the natural history of Fanconi anemia, focusing on the following variables: family history, disease presentation, development of hematological manifestations, development of malignancies, occurrence of hematopoietic stem cell transplantation and survival. Typical morphological and/or hematological abnormalities and/or growth retardation were the most common manifestations at diagnosis; the majority of patients (77%) exhibited hematological abnormalities at the initial presentation, and almost all (96%) eventually developed hematological manifestations. More than half of the patients (57%) underwent a bone-marrow transplant. The occurrence of cancer was quite rare at diagnosis, whereas the cumulative incidence of malignancies at 10, 20 and 30 years was 5%, 8% and 22%, respectively, for hematological cancers and 1%, 15% and 32%, respectively, for solid tumors. Overall survival at 10, 20 and 30 years were 88%, 56% and 37%, respectively; the main causes of death were cancer, complications of the hematological presentation and complications of transplantation. These data clearly confirm the detrimental outcome of Fanconi anemia, with no major improvement in the past decades. PMID:26635036

  9. FANCD2 Western blot as a diagnostic tool for Brazilian patients with Fanconi anemia.

    PubMed

    Pilonetto, D V; Pereira, N F; Bitencourt, M A; Magdalena, N I R; Vieira, E R; Veiga, L B A; Cavalli, I J; Ribeiro, R C; Pasquini, R

    2009-03-01

    Fanconi anemia is a rare hereditary disease showing genetic heterogeneity due to a variety of mutations in genes involved in DNA repair pathways, which may lead to different clinical manifestations. Phenotypic variability makes diagnosis difficult based only on clinical manifestations, therefore laboratory tests are necessary. New advances in molecular pathogenesis of this disease led researchers to develop a diagnostic test based on Western blot for FANCD2. The objective of the present study was to determine the efficacy of this method for the diagnosis of 84 Brazilian patients with Fanconi anemia, all of whom tested positive for the diepoxybutane test, and 98 healthy controls. The FANCD2 monoubiquitinated isoform (FANCDS+/FANCD2L-) was not detected in 77 patients (91.7%). In 2 patients (2.4%), there was an absence of both the monoubiquitinated and the non-ubiquitinated proteins (FANCD2S-/FANCD2L-) and 5 patients (5.9%) had both isoforms (FANCD2S+/FANCD2L+). This last phenotype suggests downstream subtypes or mosaicism. All controls were diepoxybutane negative and were also negative on the FANCD2 Western blot. The Western blot for FANCD2 presented a sensitivity of 94% (79/84) and specificity of 100% (98/98). This method was confirmed as an efficient approach to screen Brazilian patients with deleterious mutations on FANCD2 (FANCD2S-/FANCD2L-) or other upstream genes of the FA/BRCA pathway (FANCDS+/FANCD2L-), to confirm the chromosome breakage test and to classify patients according to the level of FA/BRCA pathway defects. However, patients showing both FANCD2 isoforms (FANCD2S+/FANCD2L+) require additional studies to confirm mutations on downstream Fanconi anemia genes or the presence of mosaicism.

  10. Gene therapy in the treatment of Fanconi anemia, a progressive bone marrow failure syndrome.

    PubMed

    Williams, David A; Croop, James; Kelly, Patrick

    2005-10-01

    Fanconi anemia (FA) is a genetic disease characterized by progressive, fatal bone marrow failure, congenital anomalies and predisposition to cancer. Although stem cell transplantation is therapeutic, human leukocyte antigen-identical sibling donors are available to a minority of patients. In murine models and human cells in vitro, gene transfer corrects the FA cellular phenotype of chromosomal breakage in response to DNA-damaging agents, suggesting therapeutic use of gene transfer is possible. However, disease-specific characteristics make application of viral vector technology difficult. Multiple studies are currently underway to develop a gene therapy approach for treating this disease, including phase I trials.

  11. Advances in the understanding of the Fanconi anemia tumor suppressor pathway.

    PubMed

    Pickering, Anna; Zhang, Jun; Panneerselvam, Jayabal; Fei, Peiwen

    2013-12-01

    Extremely high cancer incidence in Fanconi anemia (FA) patients has long suggested that the FA signaling pathway is a tumor suppressor pathway. Indeed, our recent findings, for the first time, indicate that the FA pathway plays a significant role in suppressing the development of non-FA human cancer. Also our studies on FA group D2 protein (FANCD2) have, among the first, documented the crosstalks between the FA and Rad6/Rad18 (HHR6) pathways upon DNA damage. In this review, we will discuss how our studies enhance the understanding of the FA tumor suppressor pathway.

  12. Hypomorphic mutations in the gene encoding a key Fanconi anemia protein, FANCD2, sustain a significant group of FA-D2 patients with severe phenotype.

    PubMed

    Kalb, Reinhard; Neveling, Kornelia; Hoehn, Holger; Schneider, Hildegard; Linka, Yvonne; Batish, Sat Dev; Hunt, Curtis; Berwick, Marianne; Callen, Elsa; Surralles, Jordi; Casado, Jose A; Bueren, Juan; Dasi, Angeles; Soulier, Jean; Gluckman, Eliane; Zwaan, C Michel; van Spaendonk, Rosalina; Pals, Gerard; de Winter, Johan P; Joenje, Hans; Grompe, Markus; Auerbach, Arleen D; Hanenberg, Helmut; Schindler, Detlev

    2007-05-01

    FANCD2 is an evolutionarily conserved Fanconi anemia (FA) gene that plays a key role in DNA double-strand-type damage responses. Using complementation assays and immunoblotting, a consortium of American and European groups assigned 29 patients with FA from 23 families and 4 additional unrelated patients to complementation group FA-D2. This amounts to 3%-6% of FA-affected patients registered in various data sets. Malformations are frequent in FA-D2 patients, and hematological manifestations appear earlier and progress more rapidly when compared with all other patients combined (FA-non-D2) in the International Fanconi Anemia Registry. FANCD2 is flanked by two pseudogenes. Mutation analysis revealed the expected total of 66 mutated alleles, 34 of which result in aberrant splicing patterns. Many mutations are recurrent and have ethnic associations and shared allelic haplotypes. There were no biallelic null mutations; residual FANCD2 protein of both isotypes was observed in all available patient cell lines. These analyses suggest that, unlike the knockout mouse model, total absence of FANCD2 does not exist in FA-D2 patients, because of constraints on viable combinations of FANCD2 mutations. Although hypomorphic mutations arie involved, clinically, these patients have a relatively severe form of FA.

  13. Deficiency of UBE2T, the E2 Ubiquitin Ligase Necessary for FANCD2 and FANCI Ubiquitination, Causes FA-T Subtype of Fanconi Anemia.

    PubMed

    Rickman, Kimberly A; Lach, Francis P; Abhyankar, Avinash; Donovan, Frank X; Sanborn, Erica M; Kennedy, Jennifer A; Sougnez, Carrie; Gabriel, Stacey B; Elemento, Olivier; Chandrasekharappa, Settara C; Schindler, Detlev; Auerbach, Arleen D; Smogorzewska, Agata

    2015-07-07

    Fanconi anemia (FA) is a rare bone marrow failure and cancer predisposition syndrome resulting from pathogenic mutations in genes encoding proteins participating in the repair of DNA interstrand crosslinks (ICLs). Mutations in 17 genes (FANCA-FANCS) have been identified in FA patients, defining 17 complementation groups. Here, we describe an individual presenting with typical FA features who is deficient for the ubiquitin-conjugating enzyme (E2), UBE2T. UBE2T is known to interact with FANCL, the E3 ubiquitin-ligase component of the multiprotein FA core complex, and is necessary for the monoubiquitination of FANCD2 and FANCI. Proband fibroblasts do not display FANCD2 and FANCI monoubiquitination, do not form FANCD2 foci following treatment with mitomycin C, and are hypersensitive to crosslinking agents. These cellular defects are complemented by expression of wild-type UBE2T, demonstrating that deficiency of the protein UBE2T can lead to Fanconi anemia. UBE2T gene gains an alias of FANCT.

  14. Vulvar cancer in a patient with Fanconi's anemia, treated with 3D conformal radiotherapy.

    PubMed

    Harper, Jennifer L; Jenrette, Joseph M; Goddu, S Murty; Lal, Asheesh; Smith, Tim

    2004-06-01

    Fanconi's anemia (FA) is rare autosomal recessive disorder characterized by aplastic anemia, congenital anomalies, and cancer susceptibility. FA patients have deficiencies in DNA repair pathways that cause cellular sensitivity to ionizing radiation and cross-link agents such as mitomycin C and diepoxybutane (DEB). If these patients survive until early adulthood, they are at high risk for developing solid tumors, most commonly squamous cell carcinoma of the oropharynx, esophagus, and vulva. Treatment of these solid tumors with radiotherapy is complicated by the increased risk of normal tissue toxicity. Three-dimensional (3D) conformal radiotherapy is a technique that uses CT images to more accurately target tumors and maximize the dose to the tumor volume while limiting the dose to normal tissue. This report describes application of 3D conformal radiotherapy techniques to the treatment of vulvar cancer in a patient with FA in an attempt to limit the normal tissue volume exposed to radiation. Copyright 2004 Wiley-Liss, Inc.

  15. Interstitial lung disease in an adult with Fanconi anemia: Clues to the pathogenesis

    SciTech Connect

    Rubinstein, W.S.; Wenger, S.L.; Hoffman, R.M.

    1997-03-31

    We have studied a 38-year-old man with a prior diagnosis of Holt-Oram syndrome, who presented with diabetes mellitus. He had recently taken prednisone for idiopathic interstitial lung disease and trimethoprim-sulfamethoxazole for sinusitis. Thrombocytopenia progressed to pancytopenia. The patient had skeletal, cardiac, renal, cutaneous, endocrine, hepatic, neurologic, and hematologic manifestations of Fanconi anemia (FA). Chest radiographs showed increased interstitial markings at age 25, dyspnea began in his late 20s, and he stopped smoking at age 32. At age 38, computerized tomography showed bilateral upper lobe fibrosis, lower lobe honeycombing, and bronchiectasis. Pulmonary function tests, compromised at age 29, showed a moderately severe obstructive and restrictive pattern by age 38. Serum alpha-1 antitrypsin level was 224 (normal 85-213) mg/dL and PI phenotype was M1. Karyotype was 46,X-Y with a marked increase in chromosome aberrations induced in vitro by diepoxybutane. The early onset and degree of pulmonary disease in this patient cannot be fully explained by environmental or known genetic causes. The International Fanconi Anemia Registry (IFAR) contains no example of a similar pulmonary presentation. Gene-environment (ecogenetic) interactions in FA seem evident in the final phenotype. The pathogenic mechanism of lung involvement in FA may relate to oxidative injury and cytokine anomalies. 49 refs., 2 figs., 1 tab.

  16. Fanconi Anemia Gene Editing by the CRISPR/Cas9 System

    PubMed Central

    Osborn, Mark J.; Gabriel, Richard; Webber, Beau R.; DeFeo, Anthony P.; McElroy, Amber N.; Jarjour, Jordan; Starker, Colby G.; Wagner, John E.; Joung, J. Keith; Voytas, Daniel F.; von Kalle, Christof; Schmidt, Manfred; Blazar, Bruce R.

    2015-01-01

    Abstract Genome engineering with designer nucleases is a rapidly progressing field, and the ability to correct human gene mutations in situ is highly desirable. We employed fibroblasts derived from a patient with Fanconi anemia as a model to test the ability of the clustered regularly interspaced short palindromic repeats/Cas9 nuclease system to mediate gene correction. We show that the Cas9 nuclease and nickase each resulted in gene correction, but the nickase, because of its ability to preferentially mediate homology-directed repair, resulted in a higher frequency of corrected clonal isolates. To assess the off-target effects, we used both a predictive software platform to identify intragenic sequences of homology as well as a genome-wide screen utilizing linear amplification-mediated PCR. We observed no off-target activity and show RNA-guided endonuclease candidate sites that do not possess low sequence complexity function in a highly specific manner. Collectively, we provide proof of principle for precision genome editing in Fanconi anemia, a DNA repair-deficient human disorder. PMID:25545896

  17. Origin, functional role, and clinical impact of Fanconi anemia FANCA mutations

    PubMed Central

    Castella, Maria; Pujol, Roser; Callén, Elsa; Trujillo, Juan P.; Casado, José A.; Gille, Hans; Lach, Francis P.; Auerbach, Arleen D.; Schindler, Detlev; Benítez, Javier; Porto, Beatriz; Ferro, Teresa; Muñoz, Arturo; Sevilla, Julián; Madero, Luis; Cela, Elena; Beléndez, Cristina; de Heredia, Cristina Díaz; Olivé, Teresa; de Toledo, José Sánchez; Badell, Isabel; Torrent, Montserrat; Estella, Jesús; Dasí, Ángeles; Rodríguez-Villa, Antonia; Gómez, Pedro; Barbot, José; Tapia, María; Molinés, Antonio; Figuera, Ángela; Bueren, Juan A.

    2011-01-01

    Fanconi anemia is characterized by congenital abnormalities, bone marrow failure, and cancer predisposition. To investigate the origin, functional role, and clinical impact of FANCA mutations, we determined a FANCA mutational spectrum with 130 pathogenic alleles. Some of these mutations were further characterized for their distribution in populations, mode of emergence, or functional consequences at cellular and clinical level. The world most frequent FANCA mutation is not the result of a mutational “hot-spot” but results from worldwide dissemination of an ancestral Indo-European mutation. We provide molecular evidence that total absence of FANCA in humans does not reduce embryonic viability, as the observed frequency of mutation carriers in the Gypsy population equals the expected by Hardy-Weinberg equilibrium. We also prove that long distance Alu-Alu recombination can cause Fanconi anemia by originating large interstitial deletions involving FANCA and 2 adjacent genes. Finally, we show that all missense mutations studied lead to an altered FANCA protein that is unable to relocate to the nucleus and activate the FA/BRCA pathway. This may explain the observed lack of correlation between type of FANCA mutation and cellular phenotype or clinical severity in terms of age of onset of hematologic disease or number of malformations. PMID:21273304

  18. Fanconi anemia D2 protein confers chemoresistance in response to the anticancer agent, irofulven.

    PubMed

    Wang, Yutian; Wiltshire, Timothy; Senft, Jamie; Wenger, Sharon L; Reed, Eddie; Wang, Weixin

    2006-12-01

    The Fanconi anemia-BRCA pathway of genes are frequently mutated or epigenetically repressed in human cancer. The proteins of this pathway play pivotal roles in DNA damage signaling and repair. Irofulven is one of a new class of anticancer agents that are analogues of mushroom-derived illudin toxins. Preclinical studies and clinical trials have shown that irofulven is effective against several tumor cell types. The exact nature of irofulven-induced DNA damage is not completely understood. Previously, we have shown that irofulven activates ATM and its targets, NBS1, SMC1, CHK2, and p53. In this study, we hypothesize that irofulven induces DNA double-strand breaks and FANCD2 may play an important role in modulating cellular responses and chemosensitivity in response to irofulven treatment. By using cells that are proficient or deficient for FANCD2, ATR, or ATM, we showed that irofulven induces FANCD2 monoubiquitination and nuclear foci formation. ATR is important in mediating irofulven-induced FANCD2 monoubiquitination. Furthermore, we showed that FANCD2 plays a critical role in maintaining chromosome integrity and modulating chemosensitivity in response to irofulven-induced DNA damage. Therefore, this study suggests that it might be clinically significant to target irofulven therapy to cancers defective for proteins of the Fanconi anemia-BRCA pathway.

  19. Targeting the Fanconi anemia/BRCA pathway circumvents drug resistance in multiple myeloma.

    PubMed

    Yarde, Danielle N; Oliveira, Vasco; Mathews, Linda; Wang, Xingyu; Villagra, Alejandro; Boulware, David; Shain, Kenneth H; Hazlehurst, Lori A; Alsina, Melissa; Chen, Dung-Tsa; Beg, Amer A; Dalton, William S

    2009-12-15

    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.

  20. XPF-ERCC1 participates in the Fanconi anemia pathway of cross-link repair.

    PubMed

    Bhagwat, Nikhil; Olsen, Anna L; Wang, Anderson T; Hanada, Katsuhiro; Stuckert, Patricia; Kanaar, Roland; D'Andrea, Alan; Niedernhofer, Laura J; McHugh, Peter J

    2009-12-01

    Interstrand cross-links (ICLs) prevent DNA strand separation and, therefore, transcription and replication, making them extremely cytotoxic. The precise mechanism by which ICLs are removed from mammalian genomes largely remains elusive. Genetic evidence implicates ATR, the Fanconi anemia proteins, proteins required for homologous recombination, translesion synthesis, and at least two endonucleases, MUS81-EME1 and XPF-ERCC1. ICLs cause replication-dependent DNA double-strand breaks (DSBs), and MUS81-EME1 facilitates DSB formation. The subsequent repair of these DSBs occurs via homologous recombination after the ICL is unhooked by XPF-ERCC1. Here, we examined the effect of the loss of either nuclease on FANCD2 monoubiquitination to determine if the nucleolytic processing of ICLs is required for the activation of the Fanconi anemia pathway. FANCD2 was monoubiquitinated in Mus81(-/-), Ercc1(-/-), and XPF-deficient human, mouse, and hamster cells exposed to cross-linking agents. However, the monoubiquitinated form of FANCD2 persisted longer in XPF-ERCC1-deficient cells than in wild-type cells. Moreover, the levels of chromatin-bound FANCD2 were dramatically reduced and the number of ICL-induced FANCD2 foci significantly lower in XPF-ERCC1-deficient cells. These data demonstrate that the unhooking of an ICL by XPF-ERCC1 is necessary for the stable localization of FANCD2 to the chromatin and subsequent homologous recombination-mediated DSB repair.

  1. The Fanconi anemia proteins FANCD2 and FANCJ interact and regulate each other's chromatin localization.

    PubMed

    Chen, Xiaoyong; Wilson, James B; McChesney, Patricia; Williams, Stacy A; Kwon, Youngho; Longerich, Simonne; Marriott, Andrew S; Sung, Patrick; Jones, Nigel J; Kupfer, Gary M

    2014-09-12

    Fanconi anemia is a genetic disease resulting in bone marrow failure, birth defects, and cancer that is thought to encompass a defect in maintenance of genomic stability. Mutations in 16 genes (FANCA, B, C, D1, D2, E, F, G, I, J, L, M, N, O, P, and Q) have been identified in patients, with the Fanconi anemia subtype J (FA-J) resulting from homozygous mutations in the FANCJ gene. Here, we describe the direct interaction of FANCD2 with FANCJ. We demonstrate the interaction of FANCD2 and FANCJ in vivo and in vitro by immunoprecipitation in crude cell lysates and from fractions after gel filtration and with baculovirally expressed proteins. Mutation of the monoubiquitination site of FANCD2 (K561R) preserves interaction with FANCJ constitutively in a manner that impedes proper chromatin localization of FANCJ. FANCJ is necessary for FANCD2 chromatin loading and focus formation in response to mitomycin C treatment. Our results suggest not only that FANCD2 regulates FANCJ chromatin localization but also that FANCJ is necessary for efficient loading of FANCD2 onto chromatin following DNA damage caused by mitomycin C treatment.

  2. The Fanconi Anemia Proteins FANCD2 and FANCJ Interact and Regulate Each Other's Chromatin Localization*

    PubMed Central

    Chen, Xiaoyong; Wilson, James B.; McChesney, Patricia; Williams, Stacy A.; Kwon, Youngho; Longerich, Simonne; Marriott, Andrew S.; Sung, Patrick; Jones, Nigel J.; Kupfer, Gary M.

    2014-01-01

    Fanconi anemia is a genetic disease resulting in bone marrow failure, birth defects, and cancer that is thought to encompass a defect in maintenance of genomic stability. Mutations in 16 genes (FANCA, B, C, D1, D2, E, F, G, I, J, L, M, N, O, P, and Q) have been identified in patients, with the Fanconi anemia subtype J (FA-J) resulting from homozygous mutations in the FANCJ gene. Here, we describe the direct interaction of FANCD2 with FANCJ. We demonstrate the interaction of FANCD2 and FANCJ in vivo and in vitro by immunoprecipitation in crude cell lysates and from fractions after gel filtration and with baculovirally expressed proteins. Mutation of the monoubiquitination site of FANCD2 (K561R) preserves interaction with FANCJ constitutively in a manner that impedes proper chromatin localization of FANCJ. FANCJ is necessary for FANCD2 chromatin loading and focus formation in response to mitomycin C treatment. Our results suggest not only that FANCD2 regulates FANCJ chromatin localization but also that FANCJ is necessary for efficient loading of FANCD2 onto chromatin following DNA damage caused by mitomycin C treatment. PMID:25070891

  3. Defective homing is associated with altered Cdc42 activity in cells from patients with Fanconi anemia group A

    PubMed Central

    Zhang, Xiaoling; Shang, Xun; Guo, Fukun; Murphy, Kim; Kirby, Michelle; Kelly, Patrick; Reeves, Lilith; Smith, Franklin O.; Williams, David A.

    2008-01-01

    Previous studies showed that Fanconi anemia (FA) murine stem cells have defective reconstitution after bone marrow (BM) transplantation. The mechanism underlying this defect is not known. Here, we report defective homing of FA patient BM progenitors transplanted into mouse models. Using cells from patients carrying mutations in FA complementation group A (FA-A), we show that when transplanted into nonobese diabetic/severe combined immunodeficiency (NOD/SCID) recipient mice, FA-A BM cells exhibited impaired homing activity. FA-A cells also showed defects in both cell-cell and cell-matrix adhesion. Complementation of FA-A deficiency by reexpression of FANCA readily restored adhesion of FA-A cells. A significant decrease in the activity of the Rho GTPase Cdc42 was found associated with these defective functions in patient-derived cells, and expression of a constitutively active Cdc42 mutant was able to rescue the adhesion defect of FA-A cells. These results provide the first evidence that FA proteins influence human BM progenitor homing and adhesion via the small GTPase Cdc42-regulated signaling pathway. PMID:18565850

  4. Malfunction of nuclease ERCC1-XPF results in diverse clinical manifestations and causes Cockayne syndrome, xeroderma pigmentosum, and Fanconi anemia.

    PubMed

    Kashiyama, Kazuya; Nakazawa, Yuka; Pilz, Daniela T; Guo, Chaowan; Shimada, Mayuko; Sasaki, Kensaku; Fawcett, Heather; Wing, Jonathan F; Lewin, Susan O; Carr, Lucinda; Li, Tao-Sheng; Yoshiura, Koh-ichiro; Utani, Atsushi; Hirano, Akiyoshi; Yamashita, Shunichi; Greenblatt, Danielle; Nardo, Tiziana; Stefanini, Miria; McGibbon, David; Sarkany, Robert; Fassihi, Hiva; Takahashi, Yoshito; Nagayama, Yuji; Mitsutake, Norisato; Lehmann, Alan R; Ogi, Tomoo

    2013-05-02

    Cockayne syndrome (CS) is a genetic disorder characterized by developmental abnormalities and photodermatosis resulting from the lack of transcription-coupled nucleotide excision repair, which is responsible for the removal of photodamage from actively transcribed genes. To date, all identified causative mutations for CS have been in the two known CS-associated genes, ERCC8 (CSA) and ERCC6 (CSB). For the rare combined xeroderma pigmentosum (XP) and CS phenotype, all identified mutations are in three of the XP-associated genes, ERCC3 (XPB), ERCC2 (XPD), and ERCC5 (XPG). In a previous report, we identified several CS cases who did not have mutations in any of these genes. In this paper, we describe three CS individuals deficient in ERCC1 or ERCC4 (XPF). Remarkably, one of these individuals with XP complementation group F (XP-F) had clinical features of three different DNA-repair disorders--CS, XP, and Fanconi anemia (FA). Our results, together with those from Bogliolo et al., who describe XPF alterations resulting in FA alone, indicate a multifunctional role for XPF. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  5. Transfection of normal human and Chinese hamster DNA corrects diepoxybutane-induced chromosomal hypersensitivity of Fanconi anemia fibroblasts

    SciTech Connect

    Shaham, M.; Adler, B.; Ganguly, S.; Chaganti, R.S.K.

    1987-08-01

    Cultured cells from individuals affected with Fanconi anemia (FA) exhibit spontaneous chromosome breakage and hypersensitivity to the cell killing and clastogenic effects of the difunctional alkylating agent diepoxybutane (DEB). The authors report here the correction of both of these DEB-hypersensitivity phenotypes of FA cells achieved by cotransfection of normal placental of Chinese hamster lung cell DNA and the plasmid pSV2-neo-SVgpt. Transfectants were selected for clonogenic survival after treatment with DEB at a dose of 5 ..mu..gml. At this dose of DEB, the clonogenicity of normal fibroblasts was reduced to 50% and that of FA fibroblasts was reduced to zero. DEB-resistant (DEB/sup r/) colonies selected in this system exhibited a normal response to DEB-induced chromosome breakage and resistance to repeated DEB treatment. The neo and gpt sequences were detected by Southern blot analysis of DNA from one of four DEB/sup r/ colonies independently derived from transfection of human DNA and one of three DEB/sup r/ colonies independently derived from transfection of Chinese hamster DNA. The results demonstrate that DNA sequences that complement the two hallmark cellular phenotypes (cellular and chromosomal hypersensitivity to alkylating agents) of FA are present in human as well as Chinese hamster DNA. The cloning of these genes using transfection strategies can be expected to enable molecular characterization of FA

  6. Malfunction of Nuclease ERCC1-XPF Results in Diverse Clinical Manifestations and Causes Cockayne Syndrome, Xeroderma Pigmentosum, and Fanconi Anemia

    PubMed Central

    Kashiyama, Kazuya; Nakazawa, Yuka; Pilz, Daniela T.; Guo, Chaowan; Shimada, Mayuko; Sasaki, Kensaku; Fawcett, Heather; Wing, Jonathan F.; Lewin, Susan O.; Carr, Lucinda; Li, Tao-Sheng; Yoshiura, Koh-ichiro; Utani, Atsushi; Hirano, Akiyoshi; Yamashita, Shunichi; Greenblatt, Danielle; Nardo, Tiziana; Stefanini, Miria; McGibbon, David; Sarkany, Robert; Fassihi, Hiva; Takahashi, Yoshito; Nagayama, Yuji; Mitsutake, Norisato; Lehmann, Alan R.; Ogi, Tomoo

    2013-01-01

    Cockayne syndrome (CS) is a genetic disorder characterized by developmental abnormalities and photodermatosis resulting from the lack of transcription-coupled nucleotide excision repair, which is responsible for the removal of photodamage from actively transcribed genes. To date, all identified causative mutations for CS have been in the two known CS-associated genes, ERCC8 (CSA) and ERCC6 (CSB). For the rare combined xeroderma pigmentosum (XP) and CS phenotype, all identified mutations are in three of the XP-associated genes, ERCC3 (XPB), ERCC2 (XPD), and ERCC5 (XPG). In a previous report, we identified several CS cases who did not have mutations in any of these genes. In this paper, we describe three CS individuals deficient in ERCC1 or ERCC4 (XPF). Remarkably, one of these individuals with XP complementation group F (XP-F) had clinical features of three different DNA-repair disorders—CS, XP, and Fanconi anemia (FA). Our results, together with those from Bogliolo et al., who describe XPF alterations resulting in FA alone, indicate a multifunctional role for XPF. PMID:23623389

  7. Recent discoveries in the molecular pathogenesis of the inherited bone marrow failure syndrome Fanconi anemia.

    PubMed

    Mamrak, Nicholas E; Shimamura, Akiko; Howlett, Niall G

    2016-10-13

    Fanconi anemia (FA) is a rare autosomal and X-linked genetic disease characterized by congenital abnormalities, progressive bone marrow failure (BMF), and increased cancer risk during early adulthood. The median lifespan for FA patients is approximately 33years. The proteins encoded by the FA genes function together in the FA-BRCA pathway to repair DNA damage and to maintain genome stability. Within the past two years, five new FA genes have been identified-RAD51/FANCR, BRCA1/FANCS, UBE2T/FANCT, XRCC2/FANCU, and REV7/FANCV-bringing the total number of disease-causing genes to 21. This review summarizes the discovery of these new FA genes and describes how these proteins integrate into the FA-BRCA pathway to maintain genome stability and critically prevent early-onset BMF and cancer.

  8. How SUMOylation Fine-Tunes the Fanconi Anemia DNA Repair Pathway

    PubMed Central

    Coleman, Kate E.; Huang, Tony T.

    2016-01-01

    Fanconi anemia (FA) is a rare human genetic disorder characterized by developmental defects, bone marrow failure and cancer predisposition, primarily due to a deficiency in the repair of DNA interstrand crosslinks (ICLs). ICL repair through the FA DNA repair pathway is a complicated multi-step process, involving at least 19 FANC proteins and coordination of multiple DNA repair activities, including homologous recombination, nucleotide excision repair and translesion synthesis (TLS). SUMOylation is a critical regulator of several DNA repair pathways, however, the role of this modification in controlling the FA pathway is poorly understood. Here, we summarize recent advances in the fine-tuning of the FA pathway by small ubiquitin-like modifier (SUMO)-targeted ubiquitin ligases (STUbLs) and other SUMO-related interactions, and discuss the implications of these findings in the design of novel therapeutics for alleviating FA-associated condition, including cancer. PMID:27148358

  9. The vertebrate Hef ortholog is a component of the Fanconi anemia tumor-suppressor pathway.

    PubMed

    Mosedale, Georgina; Niedzwiedz, Wojciech; Alpi, Arno; Perrina, Franco; Pereira-Leal, Jose B; Johnson, Mark; Langevin, Frederic; Pace, Paul; Patel, Ketan J

    2005-09-01

    The helicase-associated endonuclease for fork-structured DNA (Hef) is an archaeabacterial protein that processes blocked replication forks. Here we have isolated the vertebrate Hef ortholog and investigated its molecular function. Disruption of this gene in chicken DT40 cells results in genomic instability and sensitivity to DNA cross-links. The similarity of this phenotype to that of cells lacking the Fanconi anemia-related (FA) tumor-suppressor genes led us to investigate whether Hef functions in this pathway. Indeed, we found a genetic interaction between the FANCC and Hef genes. In addition, Hef is a component of the FA nuclear protein complex that facilitates its DNA damage-inducible chromatin localization and the monoubiquitination of the FA protein FANCD2. Notably, Hef interacts directly with DNA structures that are intermediates in DNA replication. This discovery sheds light on the origins, regulation and molecular function of the FA tumor-suppressor pathway in the maintenance of genome stability.

  10. X ray sensitivity of diploid skin fibroblasts from patients with Fanconi's anemia

    NASA Technical Reports Server (NTRS)

    Kale, Ranjini

    1989-01-01

    Experiments were performed on Fanconi's anemia and normal human fibroblast cell lines growing in culture in an attempt to correlate cell cycle kinetics with genomic damage and determine their bearing on the mechanism of chromosome aberration induction. FA fibroblasts showed a significantly increased susceptibility to chromosomal breakage by x rays in the G2 phase of the cell cycle. No such response was observed in fibroblasts irradiated in the G0 phase. The observed increases in achromatic lesions and in chromatid deletions in FA cells as compared with normal cells appear to indicate that FA cells are deficient in strand break repair and also possibly in base damage excision repair. Experiments are now in progress to further elucidate the mechanisms involved.

  11. Evaluation of resveratrol and N-acetylcysteine for cancer chemoprevention in a Fanconi anemia murine model.

    PubMed

    Zhang, Qing-Shuo; Marquez-Loza, Laura; Sheehan, Andrea M; Watanabe-Smith, Kevin; Eaton, Laura; Benedetti, Eric; Major, Angela; Schubert, Kathryn; Deater, Matthew; Joseph, Eric; Grompe, Markus

    2014-04-01

    Fanconi anemia (FA) patients suffer from progressive bone marrow failure and often develop cancers. Previous studies showed that antioxidants tempol and resveratrol (RV) delayed tumor onset and reduced hematologic defects in FA murine models, respectively. Here we tested whether antioxidants N-acetylcysteine (NAC) or RV could delay cancer in tumor prone Fancd2(-/-) /Trp53(+/-) mice. Unlike tempol, neither compound had any significant chemopreventive effect in this model. We conclude that not all anti-oxidants are chemopreventive in FA. In addition, when given to Fancd2(-/-) mice, NAC helped maintain Fancd2(-/-) KSL cells in quiescence while tempol did not. The mechanisms behind the different actions of these antioxidants await further investigation.

  12. The Fanconi anemia ID2 complex: dueling saxes at the crossroads.

    PubMed

    Boisvert, Rebecca A; Howlett, Niall G

    2014-01-01

    Fanconi anemia (FA) is a rare recessive genetic disease characterized by congenital abnormalities, bone marrow failure and heightened cancer susceptibility in early adulthood. FA is caused by biallelic germ-line mutation of any one of 16 genes. While several functions for the FA proteins have been ascribed, the prevailing hypothesis is that the FA proteins function cooperatively in the FA-BRCA pathway to repair damaged DNA. A pivotal step in the activation of the FA-BRCA pathway is the monoubiquitination of the FANCD2 and FANCI proteins. Despite their importance for DNA repair, the domain structure, regulation, and function of FANCD2 and FANCI remain poorly understood. In this review, we provide an overview of our current understanding of FANCD2 and FANCI, with an emphasis on their posttranslational modification and common and unique functions.

  13. Ubiquitin-SUMO circuitry controls activated fanconi anemia ID complex dosage in response to DNA damage.

    PubMed

    Gibbs-Seymour, Ian; Oka, Yasuyoshi; Rajendra, Eeson; Weinert, Brian T; Passmore, Lori A; Patel, Ketan J; Olsen, Jesper V; Choudhary, Chunaram; Bekker-Jensen, Simon; Mailand, Niels

    2015-01-08

    We show that central components of the Fanconi anemia (FA) DNA repair pathway, the tumor suppressor proteins FANCI and FANCD2 (the ID complex), are SUMOylated in response to replication fork stalling. The ID complex is SUMOylated in a manner that depends on the ATR kinase, the FA ubiquitin ligase core complex, and the SUMO E3 ligases PIAS1/PIAS4 and is antagonized by the SUMO protease SENP6. SUMOylation of the ID complex drives substrate selectivity by triggering its polyubiquitylation by the SUMO-targeted ubiquitin ligase RNF4 to promote its removal from sites of DNA damage via the DVC1-p97 ubiquitin segregase complex. Deregulation of ID complex SUMOylation compromises cell survival following replication stress. Our results uncover a regulatory role for SUMOylation in the FA pathway, and we propose that ubiquitin-SUMO signaling circuitry is a mechanism that contributes to the balance of activated ID complex dosage at sites of DNA damage.

  14. Ku70 corrupts DNA repair in the absence of the Fanconi anemia pathway.

    PubMed

    Pace, Paul; Mosedale, Georgina; Hodskinson, Michael R; Rosado, Ivan V; Sivasubramaniam, Meera; Patel, Ketan J

    2010-07-09

    A conserved DNA repair response is defective in the human genetic illness Fanconi anemia (FA). Mutation of some FA genes impairs homologous recombination and error-prone DNA repair, rendering FA cells sensitive to DNA cross-linking agents. We found a genetic interaction between the FA gene FANCC and the nonhomologous end joining (NHEJ) factor Ku70. Disruption of both FANCC and Ku70 suppresses sensitivity to cross-linking agents, diminishes chromosome breaks, and reverses defective homologous recombination. Ku70 binds directly to free DNA ends, committing them to NHEJ repair. We show that purified FANCD2, a downstream effector of the FA pathway, might antagonize Ku70 activity by modifying such DNA substrates. These results reveal a function for the FA pathway in processing DNA ends, thereby diverting double-strand break repair away from abortive NHEJ and toward homologous recombination.

  15. FANCJ suppresses microsatellite instability and lymphomagenesis independent of the Fanconi anemia pathway.

    PubMed

    Matsuzaki, Kenichiro; Borel, Valerie; Adelman, Carrie A; Schindler, Detlev; Boulton, Simon J

    2015-12-15

    Microsatellites are short tandem repeat sequences that are highly prone to expansion/contraction due to their propensity to form non-B-form DNA structures, which hinder DNA polymerases and provoke template slippage. Although error correction by mismatch repair plays a key role in preventing microsatellite instability (MSI), which is a hallmark of Lynch syndrome, activities must also exist that unwind secondary structures to facilitate replication fidelity. Here, we report that Fancj helicase-deficient mice, while phenotypically resembling Fanconi anemia (FA), are also hypersensitive to replication inhibitors and predisposed to lymphoma. Whereas metabolism of G4-DNA structures is largely unaffected in Fancj(-/-) mice, high levels of spontaneous MSI occur, which is exacerbated by replication inhibition. In contrast, MSI is not observed in Fancd2(-/-) mice but is prevalent in human FA-J patients. Together, these data implicate FANCJ as a key factor required to counteract MSI, which is functionally distinct from its role in the FA pathway.

  16. Fanconi anemia: a model disease for studies on human genetics and advanced therapeutics.

    PubMed

    Bogliolo, Massimo; Surrallés, Jordi

    2015-08-01

    Fanconi anemia (FA) is characterized by bone marrow failure, malformations, and chromosome fragility. We review the recent discovery of FA genes and efforts to develop genetic therapies for FA in the last five years. Because current data exclude FANCM as an FA gene, 15 genes remain bona fide FA genes and three (FANCO, FANCR and FANCS) cause an FA like syndrome. Monoallelic mutations in 6 FA associated genes (FANCD1, FANCJ, FANCM, FANCN, FANCO and FANCS) predispose to breast and ovarian cancer. The products of all these genes are involved in the repair of stalled DNA replication forks by unhooking DNA interstrand cross-links and promoting homologous recombination. The genetic characterization of patients with FA is essential for developing therapies, including hematopoietic stem cell transplantation from a savior sibling donor after embryo selection, gene therapy, or genome editing using genetic recombination or engineered nucleases. Newly acquired knowledge about FA promises to provide therapeutic strategies in the near future.

  17. The Fanconi anemia ID2 complex: Dueling saxes at the crossroads

    PubMed Central

    Boisvert, Rebecca A; Howlett, Niall G

    2014-01-01

    Fanconi anemia (FA) is a rare recessive genetic disease characterized by congenital abnormalities, bone marrow failure and heightened cancer susceptibility in early adulthood. FA is caused by biallelic germ-line mutation of any one of 16 genes. While several functions for the FA proteins have been ascribed, the prevailing hypothesis is that the FA proteins function cooperatively in the FA-BRCA pathway to repair damaged DNA. A pivotal step in the activation of the FA-BRCA pathway is the monoubiquitination of the FANCD2 and FANCI proteins. Despite their importance for DNA repair, the domain structure, regulation, and function of FANCD2 and FANCI remain poorly understood. In this review, we provide an overview of our current understanding of FANCD2 and FANCI, with an emphasis on their posttranslational modification and common and unique functions. PMID:25486561

  18. X ray sensitivity of diploid skin fibroblasts from patients with Fanconi's anemia

    NASA Technical Reports Server (NTRS)

    Kale, Ranjini

    1989-01-01

    Experiments were performed on Fanconi's anemia and normal human fibroblast cell lines growing in culture in an attempt to correlate cell cycle kinetics with genomic damage and determine their bearing on the mechanism of chromosome aberration induction. FA fibroblasts showed a significantly increased susceptibility to chromosomal breakage by x rays in the G2 phase of the cell cycle. No such response was observed in fibroblasts irradiated in the G0 phase. The observed increases in achromatic lesions and in chromatid deletions in FA cells as compared with normal cells appear to indicate that FA cells are deficient in strand break repair and also possibly in base damage excision repair. Experiments are now in progress to further elucidate the mechanisms involved.

  19. Diagnosis of Myelodysplastic Syndrome Among a Cohort of 119 Patients With Fanconi Anemia

    PubMed Central

    Cioc, Adina M.; Wagner, John E.; MacMillan, Margaret L.; DeFor, Todd; Hirsch, Betsy

    2017-01-01

    Predisposition to myelodysplastic syndrome (MDS) and acute leukemia is a hallmark of Fanconi anemia (FA). Morphologic criteria for MDS in FA are not well established, nor is the significance of clonal chromosomal abnormalities. We reviewed bone marrow samples of 119 FA patients: 23 had MDS, with the most common subtype refractory cytopenia with multilineage dysplasia. The presence of MDS was highly correlated with the presence of clonal abnormalities. Neutrophil dysplasia and increased blasts were always associated with the presence of a clone, in contrast with dyserythropoiesis. The most frequent clones had gains of 1q and 3q and/or loss of 7. Karyotype complexity also correlated with MDS. One third of patients with 3q as a sole abnormality had no MDS; patients with 3q and an additional abnormality all had MDS. The data provide a rationale for integrating cytogenetic findings with independently evaluated morphologic findings for monitoring bone marrow status in FA. PMID:20023263

  20. Dearth and Delayed Maturation of Testicular Germ Cells in Fanconi Anemia E Mutant Male Mice

    PubMed Central

    Fu, Chun; Begum, Khurshida; Jordan, Philip W.; He, Yan; Overbeek, Paul A.

    2016-01-01

    After using a self-inactivating lentivirus for non-targeted insertional mutagenesis in mice, we identified a transgenic family with a recessive mutation that resulted in reduced fertility in homozygous transgenic mice. The lentiviral integration site was amplified by inverse PCR. Sequencing revealed that integration had occurred in intron 8 of the mouse Fance gene, which encodes the Fanconi anemia E (Fance) protein. Fanconi anemia (FA) proteins play pivotal roles in cellular responses to DNA damage and Fance acts as a molecular bridge between the FA core complex and Fancd2. To investigate the reduced fertility in the mutant males, we analyzed postnatal development of testicular germ cells. At one week after birth, most tubules in the mutant testes contained few or no germ cells. Over the next 2–3 weeks, germ cells accumulated in a limited number of tubules, so that some tubules contained germ cells around the full periphery of the tubule. Once sufficient numbers of germ cells had accumulated, they began to undergo the later stages of spermatogenesis. Immunoassays revealed that the Fancd2 protein accumulated around the periphery of the nucleus in normal developing spermatocytes, but we did not detect a similar localization of Fancd2 in the Fance mutant testes. Our assays indicate that although Fance mutant males are germ cell deficient at birth, the extant germ cells can proliferate and, if they reach a threshold density, can differentiate into mature sperm. Analogous to previous studies of FA genes in mice, our results show that the Fance protein plays an important, but not absolutely essential, role in the initial developmental expansion of the male germ line. PMID:27486799

  1. Dearth and Delayed Maturation of Testicular Germ Cells in Fanconi Anemia E Mutant Male Mice.

    PubMed

    Fu, Chun; Begum, Khurshida; Jordan, Philip W; He, Yan; Overbeek, Paul A

    2016-01-01

    After using a self-inactivating lentivirus for non-targeted insertional mutagenesis in mice, we identified a transgenic family with a recessive mutation that resulted in reduced fertility in homozygous transgenic mice. The lentiviral integration site was amplified by inverse PCR. Sequencing revealed that integration had occurred in intron 8 of the mouse Fance gene, which encodes the Fanconi anemia E (Fance) protein. Fanconi anemia (FA) proteins play pivotal roles in cellular responses to DNA damage and Fance acts as a molecular bridge between the FA core complex and Fancd2. To investigate the reduced fertility in the mutant males, we analyzed postnatal development of testicular germ cells. At one week after birth, most tubules in the mutant testes contained few or no germ cells. Over the next 2-3 weeks, germ cells accumulated in a limited number of tubules, so that some tubules contained germ cells around the full periphery of the tubule. Once sufficient numbers of germ cells had accumulated, they began to undergo the later stages of spermatogenesis. Immunoassays revealed that the Fancd2 protein accumulated around the periphery of the nucleus in normal developing spermatocytes, but we did not detect a similar localization of Fancd2 in the Fance mutant testes. Our assays indicate that although Fance mutant males are germ cell deficient at birth, the extant germ cells can proliferate and, if they reach a threshold density, can differentiate into mature sperm. Analogous to previous studies of FA genes in mice, our results show that the Fance protein plays an important, but not absolutely essential, role in the initial developmental expansion of the male germ line.

  2. Gene Therapy in Fanconi Anemia: A Matter of Time, Safety and Gene Transfer Tool Efficiency.

    PubMed

    Verhoeyen, Els; Roman-Rodriguez, Francisco Jose; Cosset, Francois-Loic; Levy, Camille; Rio, Paula

    2017-01-01

    Fanconi anemia (FA) is a rare genetic syndrome characterized by progressive marrow failure. Gene therapy by infusion of FA-corrected autologous hematopoietic stem cells (HSCs) may offer a potential cure since it is a monogenetic disease with mutations in the FANC genes, coding for DNA repair enzymes [1]. However, the collection of hCD34+-cells in FA patients implies particular challenges because of the reduced numbers of progenitor cells present in their bone marrow (BM) [2] or mobilized peripheral blood [3-5]. In addition, the FA genetic defect fragilizes the HSCs [6]. These particular features might explain why the first clinical trials using murine leukemia virus derived retroviral vectors conducted for FA failed to show engraftment of corrected cells. The gene therapy field is now moving towards the use of lentiviral vectors (LVs) evidenced by recent succesful clinical trials for the treatment of patients suffering from adrenoleukodystrophy (ALD) [7], β-thalassemia [8], metachromatic leukodystrophy [9] and Wiskott-Aldrich syndrome [10]. LV trials for X-linked severe combined immunodificiency and Fanconi anemia (FA) defects were recently initiated [11, 12]. Fifteen years of preclinical studies using different FA mouse models and in vitro research allowed us to find the weak points in the in vitro culture and transduction conditions, which most probably led to the initial failure of FA HSC gene therapy. In this review, we will focus on the different obstacles, unique to FA gene therapy, and how they have been overcome through the development of optimized protocols for FA HSC culture and transduction and the engineering of new gene transfer tools for FA HSCs. These combined advances in the field hopefully will allow the correction of the FA hematological defect in the near future. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. Functional correction of fanconi anemia group C hematopoietic cells by the use of a novel lentiviral vector.

    PubMed

    Yamada, K; Olsen, J C; Patel, M; Rao, K W; Walsh, C E

    2001-04-01

    Lentiviral vectors transduce nondividing hematopoietic cells more efficiently than other currently available vector systems. Here we report the results of human hematopoietic cell gene transfer using lentiviral vectors based upon human immunodeficiency virus (HIV-1) and equine infectious anemia virus (EIAV). EIAV is a nonprimate lentivirus and is severely restricted in its host range to horses and closely related equines. We employed the EIAV vector system to test for gene transfer to human Fanconi anemia (FA) hematopoietic cells by comparison with HIV-1- and Moloney murine leukemia virus-based systems. Fanconi anemia is characterized by bone marrow failure secondary to stem cell dysfunction. Fanconi anemia group C EBV-transformed lymphoblasts were transduced with all three viral vectors. Phenotypic correction of FA cells, as measured by mitomycin C drug resistance, was observed with a similar efficiency in all vector systems. This is the first description of lentiviral correction of FA cells and suggests that lentiviral vectors may be useful for FA gene transfer.

  4. Fanconi anemia

    MedlinePlus

    ... count ( CBC ) Developmental tests Drugs added to a blood sample to check for damage to chromosomes Hand x-ray and other imaging studies ( CT scan , MRI ) Hearing test HLA tissue typing (to find matching bone-marrow donors) Ultrasound of ...

  5. Fanconi anemia in brothers initially diagnosed with VACTERL association with hydrocephalus, and subsequently with Baller-Gerold syndrome

    SciTech Connect

    Rossbach, H.C.; Granan, N.H.; Rossi, A.R.; Barbosa, J.L.

    1996-01-02

    Two brothers with presumed Baller-Gerold syndrome, one of whom was previously diagnosed with the association of vertebral, cardiac, renal, limb anomalies, anal atresia, tracheo-esophageal fistula (VACTERL) association with hydrocephalus, were evaluated for chromosome breakage because of severe thrombo cytopenia in one of them. Spontaneous and clastogen-induced breakage was markedly increased in both patients as compared to control individuals. Clinical manifestations and chromosome breakage, consistent with Fanconi anemia, in patients with a prior diagnosis of either Baller-Gerold syndrome, reported earlier in one other patient, or with VACTERL association with hydrocephalus, recently reported in 3 patients, underline the clinical heterogeneity of Fanconi anemia and raise the question of whether these syndromes are distinct disorders or phenotypic variations of the same disease. 12 refs., 3 figs., 1 tab.

  6. Late effects in patients with Fanconi anemia following allogeneic hematopoietic stem cell transplantation from alternative donors

    PubMed Central

    Anur, Praveen; Friedman, Danielle N; Sklar, Charles; Oeffinger, Kevin; Castiel, Mercedes; Kearney, Julia; Singh, Bhuvanesh; Prockop, Susan E; Kernan, Nancy A; Scaradavou, Andromachi; Kobos, Rachel; Curran, Kevin; Ruggiero, Julianne; Zakak, Nicole; O’Reilly, Richard J; Boulad, Farid

    2016-01-01

    Hematopoietic stem cell transplantation (HSCT) is curative for hematological manifestations of Fanconi anemia (FA). We performed a retrospective analysis of 22 patients with FA and aplastic anemia, myelodysplastic syndrome or acute myelogenous leukemia who underwent a HSCT at Memorial Sloan Kettering Cancer Center and survived at least one year post-HSCT. Patients underwent either a total body irradiation (TBI) (N=18) or busulfan (N=4) based cytoreduction followed by T-cell depleted transplants from alternative donors. Twenty patients were alive at time of study with a 5 and 10 year overall survival of 100% and 84% and no evidence of chronic GVHD. Among the 18 patients receiving a TBI-based regimen, 11 (61%) had persistent hemochromatosis, four (22%) developed hypothyroidism, seven (39%) had insulin resistance and five (27%) developed hypertriglyceridemia after transplant. Eleven of 16 evaluable patients (68%), receiving TBI, developed gonadal dysfunction. Two patients who received a TBI-based regimen died of squamous cell carcinoma. One patient developed hemochromatosis, hypothyroidism, and gonadal dysfunction after Busulfan-based cytoreduction. TBI appears to be a risk factor for malignant and endocrine late effects in the FA host. Multidisciplinary follow-up of patients with FA (including cancer screening) is essential for early detection and management of late complications, and improving long-term outcomes. PMID:26999465

  7. Successful umbilical cord blood transplantation for Fanconi anemia using preimplantation genetic diagnosis for HLA-matched donor.

    PubMed

    Bielorai, Bella; Hughes, Mark R; Auerbach, Arleen D; Nagler, Arnon; Loewenthal, Ron; Rechavi, Gideon; Toren, Amos

    2004-12-01

    Fanconi anemia is a rare autosomal recessive disease characterized by bone marrow failure, developmental anomalies, and a high incidence of myelodysplasia and acute myeloid leukemia. Stem cell transplantation is the only curative treatment. In the absence of matched- sibling donor, an alternative mismatched family or matched unrelated donor can be used, but the results are inferior to the matched-sibling transplant and carry a high risk of morbidity and mortality. Preimplantation genetic diagnosis (PGD) has been increasingly used in recent years for mutation analysis for many genetic disorders and results in the birth of healthy children, saving the need for the termination of pregnancy of an affected embryo. The use of PGD for combined analysis of mutation and HLA-matching was reported for the first time in 2001. This enables the birth of an unaffected child who can serve as a donor for an affected sibling in need for stem cell transplantation. We report successful cord blood transplantation for a Fanconi anemia patient from his HLA-matched sibling, born after PGD that included mutation analysis for Fanconi anemia and HLA typing. PGD can provide an unaffected donor for a sibling affected by genetic disease in the absence of a compatible related donor. 2004 Wiley-Liss, Inc.

  8. Elevated levels of STAT1 in Fanconi anemia group A lymphoblasts correlate with the cells’ sensitivity to DNA interstrand crosslinking drugs

    PubMed Central

    Prieto-Remón, Inés; Sánchez-Carrera, Dámaso; López-Duarte, Mónica; Richard, Carlos; Pipaón, Carlos

    2013-01-01

    Progressive bone marrow failure starting in the first decade of life is one of the main characteristics of Fanconi anemia. Along with the bone marrow failure, this pathology is characterized by congenital malformations, endocrine dysfunction and an extraordinary predisposition to develop cancer. The fact that hematopoietic progenitor cells from subjects with Fanconi anemia are sensitive to both DNA-interstrand crosslinking agents and inflammatory cytokines, which are aberrantly overproduced in these patients, has led to different explanations for the causes of the bone marrow failure. We analyzed STAT1 expression in lymphoblastoid cell lines derived from patients with Fanconi anemia group A and correlated this with aspects of the Fanconi anemia phenotype such as sensitivity to genotoxic agents or to inhibitory cytokines. We provide evidence of overexpression of STAT1 in FANCA-deficient cells which has both transcriptional and post-translational components, and is related to the constitutive activation of ERK in Fanconi anemia group A cells, since it can be reverted by treatment with U0126. STAT1 phosphorylation was not defective in the lymphoblasts, so these cells accumulated higher levels of active STAT1 in response to interferon gamma, probably in relation to their greater sensitivity to this cytokine. On the other hand, inhibition of STAT1 by genetic or chemical means reverted the hypersensitivity of Fanconi anemia group A lymphoblasts to DNA interstrand crosslinking agents. Our data provide an explanation for the mixed sensitivity of Fanconi anemia group A cells to both genotoxic stress and inflammatory cytokines and indicate new targets for the treatment of bone marrow failure in these patients. PMID:23585528

  9. Correction of both spontaneous and DEB-induced chromosome instability in Fanconi anemia FA-C cells by FACC cDNA

    SciTech Connect

    Stavropoulos, D.J.; Tomkins, D.J.; Allingham-Hawkins, D.J.; Buchwald, M.

    1994-09-01

    Cells from all four Fanconi anemia complementation groups show hypersensitivity to cell-killing by mitomycin C (MMC), diepoxybutane (DEB) and other DNA cross-linking agents, and increased spontaneous and DEB-induced chromosome aberrations (CA). The extent of these phenotypes varies between lymphoblastoid cell lines from different complementation groups. Our data showed that the difference in MMC hypersensitivity and DEB-CA was not always coupled. While 230N (FA-B) had higher DEB-induced CA/cell than 536N (FA-C) (7.42 vs. 4.46 respectively), that latter was much more sensitive to cell-killing by MMC (dose at 10% survival, D{sub 10}: 5.2 vs. 1.2 ng/ml respectively). Strathdes et al. (1992) cloned a cDNA Fanconi anemia complementation group C (FACC) which complemented the hypersensitivity to MMC and DEB cell-killing of FA-C cells (536N) but not cells from the other three complementation groups. The present study was initiated to determine whether chromosome instability in 536N is also complemented by the FACC (FAC3) cDNA. The pREP4-FAC3 vector was transfected into 536N and transfectants selected with hygromycin B. The DEB D{sub 10} of 536N (1.0 {mu}M) was corrected to the control level (16.2 {mu}M for 3TO) by FACC (15.1 {mu}M for 536N-FACC), as previously demonstrated. Chromosome instability (cab, cse, ctb, cte) was determined without and with 0.1 {mu}g/ml DEB treatment. Spontaneous CA of 536N (0.30 aberrations/cell) was corrected to the control level (0.04 for 3TO) by FACC (0.06 for 536N-FACC). Similarly, the DEB-induced CA was corrected (2.74 for 536N vs. 0.06 and 0.02 for 3TO and 536N-FACC respectively). Thus, at least for FA complementation group C, hypersensitivity to cell-killing and chromosome instability are not dissociated and are most likely caused by the same gene defect.

  10. Identification of multiple nuclear export sequences in Fanconi anemia group A protein that contribute to CRM1-dependent nuclear export.

    PubMed

    Ferrer, Miriam; Rodríguez, Jose A; Spierings, Ellen A; de Winter, Johan P; Giaccone, Giuseppe; Kruyt, Frank A E

    2005-05-15

    The Fanconi anemia (FA) pathway plays an important role in maintaining genomic stability, and defects in this pathway cause cancer susceptibility. The FA proteins have been found to function primarily in a nuclear complex, although a cytoplasmic localization and function for several FA proteins has also been reported. In this study, we investigated the possibility that FANCA, FANCC and FANCG are subjected to active export out of the nucleus. After treatment with leptomycin B, a specific inhibitor of CRM1-mediated nuclear export, the accumulation of epitope-tagged FANCA in the nucleus increased, whereas FANCC was affected to a lesser extent and FANCG showed no response. CRM1-mediated export of FANCA was further confirmed using CRM1 cotransfection, which led to a dramatic relocalization of FANCA to the cytoplasm. Five functional leucine-rich nuclear export sequences (NESs) distributed throughout the FANCA sequence were identified and characterized using an in vivo export assay. Simultaneous inactivation of three of these NESs resulted in a discrete but reproducible increase of FANCA nuclear accumulation. However, these NES mutations did not affect the ability of FANCA to complement the mitomycin C or cisplatin sensitivity of FA-A lymphoblasts. Surprisingly, mutations in the other two NESs resulted in an almost complete relocation of the protein to cytoplasm, suggesting that these motifs overlap with domains that are crucial for nuclear import. Taken together, these findings indicate that FANCA can be actively exported out of the nucleus by CRM1, revealing a new mechanism to regulate the function of the FA protein complex.

  11. Therapeutic complement inhibition in complement-mediated hemolytic anemias: Past, present and future.

    PubMed

    Risitano, Antonio M; Marotta, Serena

    2016-06-01

    The introduction in the clinic of anti-complement agents represented a major achievement which gave to physicians a novel etiologic treatment for different human diseases. Indeed, the first anti-complement agent eculizumab has changed the treatment paradigm of paroxysmal nocturnal hemoglobinuria (PNH), dramatically impacting its severe clinical course. In addition, eculizumab is the first agent approved for atypical Hemolytic Uremic Syndrome (aHUS), a life-threatening inherited thrombotic microangiopathy. Nevertheless, such remarkable milestone in medicine has brought to the fore additional challenges for the scientific community. Indeed, the list of complement-mediated anemias is not limited to PNH and aHUS, and other human diseases can be considered for anti-complement treatment. They include other thrombotic microangiopathies, as well as some antibody-mediated hemolytic anemias. Furthermore, more than ten years of experience with eculizumab led to a better understanding of the individual steps of the complement cascade involved in the pathophysiology of different human diseases. Based on this, new unmet clinical needs are emerging; a number of different strategies are currently under development to improve current anti-complement treatment, trying to address these specific clinical needs. They include: (i) alternative anti-C5 agents, which may improve the heaviness of eculizumab treatment; (ii) broad-spectrum anti-C3 agents, which may improve the efficacy of anti-C5 treatment by intercepting the complement cascade upstream (i.e., preventing C3-mediated extravascular hemolysis in PNH); (iii) targeted inhibitors of selective complement activating pathways, which may prevent early pathogenic events of specific human diseases (e.g., anti-classical pathway for antibody-mediated anemias, or anti-alternative pathway for PNH and aHUS). Here we briefly summarize the status of art of current and future complement inhibition for different complement-mediated anemias

  12. Gender-related differences in the oxidant state of cells in Fanconi anemia heterozygotes.

    PubMed

    Petrovic, Sandra; Leskovac, Andreja; Kotur-Stevuljevic, Jelena; Joksic, Jelena; Guc-Scekic, Marija; Vujic, Dragana; Joksic, Gordana

    2011-07-01

    Abstract Fanconi anemia (FA) is a rare cancer-prone genetic disorder characterized by progressive bone marrow failure, chromosomal instability and redox abnormalities. There is much biochemical and genetic data, which strongly suggest that FA cells experience increased oxidative stress. The present study was designed to elucidate if differences in oxidant state exist between control, idiopathic bone marrow failure (idBMF) and FA cells, and to analyze oxidant state of cells in FA heterozygous carriers as well. The results of the present study confirm an in vivo prooxidant state of FA cells and clearly indicate that FA patients can be distinguished from idBMF patients based on the oxidant state of cells. Female carriers of FA mutation also exhibited hallmarks of an in vivo prooxidant state behaving in a similar manner as FA patients. On the other hand, the oxidant state of cells in FA male carriers and idBMF families failed to show any significant difference vs. controls. We demonstrate that the altered oxidant state influences susceptibility of cells to apoptosis in both FA patients and female carriers. The results highlight the need for further research of the possible role of mitochondrial inheritance in the pathogenesis of FA.

  13. Plasma ultrafiltrates from Fanconi Anemia patients induces chromosomal breakages in donor lymphocytes

    SciTech Connect

    Emerit, I.; Levy, A.; Pagano, G.

    1994-09-01

    The present study investigated the occurrence, if any, of transferable clastogenic activity in the plasma from Fanconi Anemia (FA) patients and their families. A total of 13 FA homozygotes, 25 parents, and 12 siblings were studied for their: (a) spontaneous and DEB-induced chromosomal instability, and (b) induction of chromosomal breaks in peripheral blood lymphocytes (PBL) from healthy donors, following exposure to plasma ultrafiltrates from FA subjects, their parents or siblings. Plasma was ultrafiltered through membranes with a cutoff at 10,000 daltons (YM 10 Amicon) and 0.25 ml-aliquote added to PBL from 14 healthy donors. DEB test provided FA confirmatory diagnosis. The occurrence of clastogenic factors (CF) was evident in all FA patients, except for one. In two out of three patients, who died during this study, very high CF levels were observed. Clastogenic activity was significantly higher in male than in female patients (p<0.05). No correlation was observed between CF data and spontaneous or DEB-induced chromosomal instability. Ultrafiltrates from parents and siblings showed less CF than FA homozygotes; however, concentration by ultrafiltration through YM 2 (3x to 5x) led to excess clastogenic activity. The control plasmas were lacking CF even after an 8x concentration. The present data suggest that CF formation in the plasma of FA patients is consistent with an in vivo prooxident state in FA.

  14. Bone mineral density in children with Fanconi anemia after hematopoietic cell transplantation

    PubMed Central

    Petryk, Anna; Polgreen, Lynda E.; Barnum, Jessie L.; Zhang, Lei; Hodges, James S.; Baker, K. Scott; Wagner, John E.; Steinberger, Julia; MacMillan, Margaret L.

    2015-01-01

    Fanconi anemia (FA) is an inherited DNA repair disorder associated with short stature and bone marrow failure usually requiring hematopoietic cell transplant (HCT). While low bone mineral density (BMD) has been reported in leukemia patients after HCT, little is known about BMD in FA children after HCT (FA HCT). This study's goals were to compare BMD in FA HCT to BMD in healthy controls, and in children who received HCT for hematologic malignancy (Cancer HCT), and to test for associations between BMD and risk factors for bone loss. This cross-sectional study included 20 FA HCT, 13 Cancer HCT, and 90 healthy controls, age-matched and <18 years old at evaluation. BMD Z-scores for total body (TBMD) and lumbar spine (LBMD) were measured by dual energy x-ray absorptiometry and adjusted for height-forage Z-score (HAZ). FA HCT had lower mean TBMDHAZ Z-score (by 0.8 SD) and higher fraction with Z-score ≤ −1 than healthy controls (42% vs. 11%). No LBMD deficits were detected. FA HCT and Cancer HCT groups did not differ significantly in TBMD or LBMD Z-scores. In FA HCT patients, lower BMI and lower percent fat were associated with lower BMD. This study highlights the importance of monitoring BMD to optimize bone health in FA patients. PMID:25591848

  15. Bone mineral density in children with fanconi anemia after hematopoietic cell transplantation.

    PubMed

    Petryk, Anna; Polgreen, Lynda E; Barnum, Jessie L; Zhang, Lei; Hodges, James S; Baker, K Scott; Wagner, John E; Steinberger, Julia; MacMillan, Margaret L

    2015-05-01

    Fanconi anemia (FA) is an inherited DNA repair disorder associated with short stature and bone marrow failure, usually requiring hematopoietic cell transplantation (HCT). Although low bone mineral density (BMD) has been reported in leukemia patients after HCT, little is known about BMD in FA children after HCT (FA HCT). This study's goals were to compare BMD in FA HCT to BMD in healthy controls and in children who received HCT for hematologic malignancy (cancer HCT), and to test for associations between BMD and risk factors for bone loss. This cross-sectional study included 20 FA HCT, 13 cancer HCT, and 90 healthy controls, age-matched and <18 years old at evaluation. BMD Z-scores for total body (TBMD) and lumbar spine (LBMD) were measured by dual energy x-ray absorptiometry and adjusted for height-for-age Z-score (HAZ). FA HCT had lower mean TBMDHAZ Z-score (by .8 SD) and higher fraction with Z-score ≤ -1 than healthy controls (42% versus 11%). No LBMD deficits were detected. FA HCT and cancer HCT groups did not differ significantly in TBMD or LBMD Z-scores. In FA HCT patients, lower body mass index and lower percent fat were associated with lower BMD. This study highlights the importance of monitoring BMD to optimize bone health in FA patients.

  16. Endocrinopathies, Bone Health, and Insulin Resistance in Patients with Fanconi Anemia after Hematopoietic Cell Transplantation.

    PubMed

    Barnum, Jessie L; Petryk, Anna; Zhang, Lei; DeFor, Todd E; Baker, K Scott; Steinberger, Julia; Nathan, Brandon; Wagner, John E; MacMillan, Margaret L

    2016-08-01

    A number of endocrinopathies have been described after hematopoietic cell transplantation (HCT), but data are limited in patients with Fanconi anemia (FA). We report several endocrine-based disorders in a cohort of 44 patients with FA after HCT compared with both 74 patients who received HCT for hematologic malignancies and with 275 healthy controls. Endocrinopathies assessed included hypothyroidism, hypogonadism, short stature, dyslipidemia, insulin resistance, abnormalities in body composition, and bone health. Most (86%) patients with FA had at least 1 endocrinopathy, with 11% having 3 or more. Hypothyroidism was seen in 57%, hypogonadism in 27%, short stature in 50%, and reduced total body and lumbar spine bone mineral density (BMD) (height adjusted Z-score < -1) in 57% and 21%, respectively. Vitamin D deficiency was seen in 71%. Short stature was associated with younger age at HCT and gonadal failure was associated with older age at HCT. Insulin resistance was associated with increased percent fat mass and increased android/gynoid ratio by dual energy X-ray absorptiometry. Hypothyroidism, short stature, and reduced total body BMD were more prevalent in patients with FA compared with patients with hematologic malignancies. We recommend an assessment before transplantation and close follow-up afterwards to ensure proper clinical management. Future studies should continue to explore the impact of HCT on endocrinopathies in FA patients.

  17. FAAP100 is essential for activation of the Fanconi anemia-associated DNA damage response pathway.

    PubMed

    Ling, Chen; Ishiai, Masamichi; Ali, Abdullah Mahmood; Medhurst, Annette L; Neveling, Kornelia; Kalb, Reinhard; Yan, Zhijiang; Xue, Yutong; Oostra, Anneke B; Auerbach, Arleen D; Hoatlin, Maureen E; Schindler, Detlev; Joenje, Hans; de Winter, Johan P; Takata, Minoru; Meetei, Amom Ruhikanta; Wang, Weidong

    2007-04-18

    The Fanconi anemia (FA) core complex plays a central role in the DNA damage response network involving breast cancer susceptibility gene products, BRCA1 and BRCA2. The complex consists of eight FA proteins, including a ubiquitin ligase (FANCL) and a DNA translocase (FANCM), and is essential for monoubiquitination of FANCD2 in response to DNA damage. Here, we report a novel component of this complex, termed FAAP100, which is essential for the stability of the core complex and directly interacts with FANCB and FANCL to form a stable subcomplex. Formation of this subcomplex protects each component from proteolytic degradation and also allows their coregulation by FANCA and FANCM during nuclear localization. Using siRNA depletion and gene knockout techniques, we show that FAAP100-deficient cells display hallmark features of FA cells, including defective FANCD2 monoubiquitination, hypersensitivity to DNA crosslinking agents, and genomic instability. Our study identifies FAAP100 as a new critical component of the FA-BRCA DNA damage response network.

  18. Identification of FAAP24, a Fanconi anemia core complex protein that interacts with FANCM.

    PubMed

    Ciccia, Alberto; Ling, Chen; Coulthard, Rachel; Yan, Zhijiang; Xue, Yutong; Meetei, Amom Ruhikanta; Laghmani, El Houari; Joenje, Hans; McDonald, Neil; de Winter, Johan P; Wang, Weidong; West, Stephen C

    2007-02-09

    The Fanconi anemia (FA) core complex plays a crucial role in a DNA damage response network with BRCA1 and BRCA2. How this complex interacts with damaged DNA is unknown, as only the FA core protein FANCM (the homolog of an archaeal helicase/nuclease known as HEF) exhibits DNA binding activity. Here, we describe the identification of FAAP24, a protein that targets FANCM to structures that mimic intermediates formed during the replication/repair of damaged DNA. FAAP24 shares homology with the XPF family of flap/fork endonucleases, associates with the C-terminal region of FANCM, and is a component of the FA core complex. FAAP24 is required for normal levels of FANCD2 monoubiquitylation following DNA damage. Depletion of FAAP24 by siRNA results in cellular hypersensitivity to DNA crosslinking agents and chromosomal instability. Our data indicate that the FANCM/FAAP24 complex may play a key role in recruitment of the FA core complex to damaged DNA.

  19. Hypersensitivities for acetaldehyde and other agents among cancer cells null for clinically relevant Fanconi anemia genes.

    PubMed

    Ghosh, Soma; Sur, Surojit; Yerram, Sashidhar R; Rago, Carlo; Bhunia, Anil K; Hossain, M Zulfiquer; Paun, Bogdan C; Ren, Yunzhao R; Iacobuzio-Donahue, Christine A; Azad, Nilofer A; Kern, Scott E

    2014-01-01

    Large-magnitude numerical distinctions (>10-fold) among drug responses of genetically contrasting cancers were crucial for guiding the development of some targeted therapies. Similar strategies brought epidemiological clues and prevention goals for genetic diseases. Such numerical guides, however, were incomplete or low magnitude for Fanconi anemia pathway (FANC) gene mutations relevant to cancer in FANC-mutation carriers (heterozygotes). We generated a four-gene FANC-null cancer panel, including the engineering of new PALB2/FANCN-null cancer cells by homologous recombination. A characteristic matching of FANCC-null, FANCG-null, BRCA2/FANCD1-null, and PALB2/FANCN-null phenotypes was confirmed by uniform tumor regression on single-dose cross-linker therapy in mice and by shared chemical hypersensitivities to various inter-strand cross-linking agents and γ-radiation in vitro. Some compounds, however, had contrasting magnitudes of sensitivity; a strikingly high (19- to 22-fold) hypersensitivity was seen among PALB2-null and BRCA2-null cells for the ethanol metabolite, acetaldehyde, associated with widespread chromosomal breakage at a concentration not producing breaks in parental cells. Because FANC-defective cancer cells can share or differ in their chemical sensitivities, patterns of selective hypersensitivity hold implications for the evolutionary understanding of this pathway. Clinical decisions for cancer-relevant prevention and management of FANC-mutation carriers could be modified by expanded studies of high-magnitude sensitivities.

  20. The Fanconi anemia DNA damage repair pathway in the spotlight for germline predisposition to colorectal cancer

    PubMed Central

    Esteban-Jurado, Clara; Franch-Expósito, Sebastià; Muñoz, Jenifer; Ocaña, Teresa; Carballal, Sabela; López-Cerón, Maria; Cuatrecasas, Miriam; Vila-Casadesús, Maria; Lozano, Juan José; Serra, Enric; Beltran, Sergi; Brea-Fernández, Alejandro; Ruiz-Ponte, Clara; Castells, Antoni; Bujanda, Luis; Garre, Pilar; Caldés, Trinidad; Cubiella, Joaquín; Balaguer, Francesc; Castellví-Bel, Sergi

    2016-01-01

    Colorectal cancer (CRC) is one of the most common neoplasms in the world. Fanconi anemia (FA) is a very rare genetic disease causing bone marrow failure, congenital growth abnormalities and cancer predisposition. The comprehensive FA DNA damage repair pathway requires the collaboration of 53 proteins and it is necessary to restore genome integrity by efficiently repairing damaged DNA. A link between FA genes in breast and ovarian cancer germline predisposition has been previously suggested. We selected 74 CRC patients from 40 unrelated Spanish families with strong CRC aggregation compatible with an autosomal dominant pattern of inheritance and without mutations in known hereditary CRC genes and performed germline DNA whole-exome sequencing with the aim of finding new candidate germline predisposition variants. After sequencing and data analysis, variant prioritization selected only those very rare alterations, producing a putative loss of function and located in genes with a role compatible with cancer. We detected an enrichment for variants in FA DNA damage repair pathway genes in our familial CRC cohort as 6 families carried heterozygous, rare, potentially pathogenic variants located in BRCA2/FANCD1, BRIP1/FANCJ, FANCC, FANCE and REV3L/POLZ. In conclusion, the FA DNA damage repair pathway may play an important role in the inherited predisposition to CRC. PMID:27165003

  1. The Fanconi Anemia Pathway Protects Genome Integrity from R-loops.

    PubMed

    García-Rubio, María L; Pérez-Calero, Carmen; Barroso, Sonia I; Tumini, Emanuela; Herrera-Moyano, Emilia; Rosado, Iván V; Aguilera, Andrés

    2015-11-01

    Co-transcriptional RNA-DNA hybrids (R loops) cause genome instability. To prevent harmful R loop accumulation, cells have evolved specific eukaryotic factors, one being the BRCA2 double-strand break repair protein. As BRCA2 also protects stalled replication forks and is the FANCD1 member of the Fanconi Anemia (FA) pathway, we investigated the FA role in R loop-dependent genome instability. Using human and murine cells defective in FANCD2 or FANCA and primary bone marrow cells from FANCD2 deficient mice, we show that the FA pathway removes R loops, and that many DNA breaks accumulated in FA cells are R loop-dependent. Importantly, FANCD2 foci in untreated and MMC-treated cells are largely R loop dependent, suggesting that the FA functions at R loop-containing sites. We conclude that co-transcriptional R loops and R loop-mediated DNA damage greatly contribute to genome instability and that one major function of the FA pathway is to protect cells from R loops.

  2. Fanconi anemia proteins FANCD2 and FANCI exhibit different DNA damage responses during S-phase

    PubMed Central

    Sareen, Archana; Chaudhury, Indrajit; Adams, Nicole; Sobeck, Alexandra

    2012-01-01

    Fanconi anemia (FA) pathway members, FANCD2 and FANCI, contribute to the repair of replication-stalling DNA lesions. FA pathway activation relies on phosphorylation of FANCI by the ataxia telangiectasia and Rad3-related (ATR) kinase, followed by monoubiquitination of FANCD2 and FANCI by the FA core complex. FANCD2 and FANCI are thought to form a functional heterodimer during DNA repair, but it is unclear how dimer formation is regulated or what the functions of the FANCD2–FANCI complex versus the monomeric proteins are. We show that the FANCD2–FANCI complex forms independently of ATR and FA core complex, and represents the inactive form of both proteins. DNA damage-induced FA pathway activation triggers dissociation of FANCD2 from FANCI. Dissociation coincides with FANCD2 monoubiquitination, which significantly precedes monoubiquitination of FANCI; moreover, monoubiquitination responses of FANCD2 and FANCI exhibit distinct DNA substrate specificities. A phosphodead FANCI mutant fails to dissociate from FANCD2, whereas phosphomimetic FANCI cannot interact with FANCD2, indicating that FANCI phosphorylation is the molecular trigger for FANCD2–FANCI dissociation. Following dissociation, FANCD2 binds replicating chromatin prior to—and independently of—FANCI. Moreover, the concentration of chromatin-bound FANCD2 exceeds that of FANCI throughout replication. Our results suggest that FANCD2 and FANCI function separately at consecutive steps during DNA repair in S-phase. PMID:22753026

  3. The Fanconi anemia associated protein FAAP24 uses two substrate specific binding surfaces for DNA recognition

    PubMed Central

    Wienk, Hans; Slootweg, Jack C.; Speerstra, Sietske; Kaptein, Robert; Boelens, Rolf; Folkers, Gert E.

    2013-01-01

    To maintain the integrity of the genome, multiple DNA repair systems exist to repair damaged DNA. Recognition of altered DNA, including bulky adducts, pyrimidine dimers and interstrand crosslinks (ICL), partially depends on proteins containing helix-hairpin-helix (HhH) domains. To understand how ICL is specifically recognized by the Fanconi anemia proteins FANCM and FAAP24, we determined the structure of the HhH domain of FAAP24. Although it resembles other HhH domains, the FAAP24 domain contains a canonical hairpin motif followed by distorted motif. The HhH domain can bind various DNA substrates; using nuclear magnetic resonance titration experiments, we demonstrate that the canonical HhH motif is required for double-stranded DNA (dsDNA) binding, whereas the unstructured N-terminus can interact with single-stranded DNA. Both DNA binding surfaces are used for binding to ICL-like single/double-strand junction-containing DNA substrates. A structural model for FAAP24 bound to dsDNA has been made based on homology with the translesion polymerase iota. Site-directed mutagenesis, sequence conservation and charge distribution support the dsDNA-binding model. Analogous to other HhH domain-containing proteins, we suggest that multiple FAAP24 regions together contribute to binding to single/double-strand junction, which could contribute to specificity in ICL DNA recognition. PMID:23661679

  4. Therapeutic gene editing in CD34(+) hematopoietic progenitors from Fanconi anemia patients.

    PubMed

    Diez, Begoña; Genovese, Pietro; Roman-Rodriguez, Francisco J; Alvarez, Lara; Schiroli, Giulia; Ugalde, Laura; Rodriguez-Perales, Sandra; Sevilla, Julian; Diaz de Heredia, Cristina; Holmes, Michael C; Lombardo, Angelo; Naldini, Luigi; Bueren, Juan Antonio; Rio, Paula

    2017-09-12

    Gene targeting constitutes a new step in the development of gene therapy for inherited diseases. Although previous studies have shown the feasibility of editing fibroblasts from Fanconi anemia (FA) patients, here we aimed at conducting therapeutic gene editing in clinically relevant cells, such as hematopoietic stem cells (HSCs). In our first experiments, we showed that zinc finger nuclease (ZFN)-mediated insertion of a non-therapeutic EGFP-reporter donor in the AAVS1 "safe harbor" locus of FA-A lymphoblastic cell lines (LCLs), indicating that FANCA is not essential for the editing of human cells. When the same approach was conducted with therapeutic FANCA donors, an efficient phenotypic correction of FA-A LCLs was obtained. Using primary cord blood CD34(+) cells from healthy donors, gene targeting was confirmed not only in in vitro cultured cells, but also in hematopoietic precursors responsible for the repopulation of primary and secondary immunodeficient mice. Moreover, when similar experiments were conducted with mobilized peripheral blood CD34(+) cells from FA-A patients, we could demonstrate for the first time that gene targeting in primary hematopoietic precursors from FA patients is feasible and compatible with the phenotypic correction of these clinically relevant cells. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

  5. Salivary flow rate, calcium, urea, total protein, and amylase levels in fanconi anemia.

    PubMed

    Mattioli, Tatiana Maria Folador; Koubik, Ana Cláudia; de Oliveira Ribas, Marina; França, Beatriz Helena Sottile; Brancher, João Armando; de Lima, Antonio Adilson Soares

    2010-03-01

    Fanconi anemia (FA) is a genetic disease characterized by a chromosomal instability that develops a progressive pancitopenia, leukemia, and/or solid tumors. Nevertheless, it is unknown if this illness induces changes on the salivary gland parenchyma and function. The aim of this study was to assess the stimulated salivary flow rate (SSFR) and calcium, urea, total protein, and amylase levels in saliva of FA patients. Stimulated whole saliva was collected from 34 randomly selected FA patients and 34 age-matched and sex-matched controls. Both samples were analyzed for salivary flow rate, calcium, urea, total proteins, and amylase. The SSFR was analyzed by gravimetric method and calcium, urea, total protein, and amylase concentrations were realized by chemistry tests. Mean values of SSFR for experimental and control groups were, respectively, 0.5 mL/min and 0.8 mL/min (P<0.05). Calcium concentration was 36% (P<0.05) and urea concentration was 21% (P<0.01) lower in the FA group saliva compared with saliva from the controls. The saliva concentration of amylase was almost equal in both groups. FA patients may exhibit significant changes in SSFR, calcium, and urea concentration of saliva.

  6. [Enrichment analysis of Fanconi anemia gene expression profiles in cancer related genesets].

    PubMed

    Zhou, Quan-quan; Wang, Xiao-juan; Zhu, Xiao-fan; Yuan, Wei-ping; Cheng, Tao

    2012-05-01

    To investigate the underlying tumor susceptibility mechanisms and reasons for the high risk of cancer in Fanconi anemia (FA). Gene Set Enrichment Analysis (GSEA) was performed to compare gene expression profiles between 21 FA patients' bone marrow (BM) mononuclear cell (BMNC) and 11 normal controls in cancer related gene sets from NCBI GEO database, then core enriched genes were identified by further investigation. Through enrichment analyzing biological processes of gene ontology sets and structural genomic gene sets between FA expression profiles and control, more details related with its tumor susceptibility had been revealed. Compared with normal control, gene expression in FA group had significant been enriched in resistance to Bcl-2 inhibitor gene set, fibroblast growth factors signalling pathways, insulin and insulin-like growth factors (IGF) signalling pathways induced cancer genesis gene sets. The high level of D4S234E, SST, FGFs, IGFs, FGFRs and IGFBP expression provided an initiate environment for tumorgenesis and drug resistance. There were significant differences in biogenesis extracellular molecules and cytomembrane structure organizations between FA and control. Genes with promoter regions around transcription start sites containing either motif RRCAGGTGNCV or CCTNTMAGA were enriched and those former genes match annotation for tumorgenic transcription factor 3 (TCF3). The high tumor susceptibility of FA patients may be closely related with the dramatic changes in cancer related growth factors and hormones environment. This study provides new insights into tumor susceptibility mechanism in FA patients.

  7. Programmable Bio-Nano-Chip based Cytologic Testing of Oral Potentially Malignant Disorders in Fanconi Anemia

    PubMed Central

    Floriano, Pierre; Abram, Tim; Taylor, Leander; Le, Cathy; Talavera, Humberto; Nguyen, Michael; Raja, Rameez; Gillenwater, Ann; McDevitt, John; Vigneswaran, Nadarajah

    2015-01-01

    Fanconi anemia (FA) is caused by mutations of DNA repair genes. The risk of oral squamous cell carcinoma (OSCC) among FA patients is 800-folds higher than in the general population. Early detection of OSCC, preferably at it precursor stage is critical in FA patients to improve their survival. In an ongoing clinical trial, we are evaluating the effectiveness of the programmable bio-nano-chip (p-BNC)-based oral cytology test in diagnosing oral potentially malignant disorders (OPMD) in non-FA patients. We used this test to compare the cytomorphometric and molecular biomarkers in OSCC cell lines derived from FA patients and non-FA patients and brush biopsy samples of a FA patient’s OPMD and normal mucosa of healthy volunteers. Our data showed that expression patterns of molecular biomarkers were not notably different between sporadic and FA OSCC cell lines. The p-BNC assay revealed significant differences in cytometric parameters and biomarker MCM2 expression between cytobrush samples of the FA patient and cytobrush samples of normal oral mucosa obtained from healthy volunteers. Microscopic examination of the FA patient’s OPMD confirmed the presence of dysplasia. Our pilot data suggests that p-BNC brush biopsy test recognizes dysplastic oral epithelial cells in a brush biopsy sample of a FA patient. PMID:25662766

  8. Programmable bio-nanochip-based cytologic testing of oral potentially malignant disorders in Fanconi anemia.

    PubMed

    Floriano, P N; Abram, T; Taylor, L; Le, C; Talavera, H; Nguyen, M; Raja, R; Gillenwater, A; McDevitt, J; Vigneswaran, N

    2015-07-01

    Fanconi anemia (FA) is caused by mutations of DNA repair genes. The risk of oral squamous cell carcinoma (OSCC) among FA patients is 800-folds higher than in the general population. Early detection of OSCC, preferably at it precursor stage, is critical in FA patients to improve their survival. In an ongoing clinical trial, we are evaluating the effectiveness of the programmable bio-nanochip (p-BNC)-based oral cytology test in diagnosing oral potentially malignant disorders (OPMD) in non-FA patients. We used this test to compare cytomorphometric and molecular biomarkers in OSCC cell lines derived from FA and non-FA patients to brush biopsy samples of a FA patient with OPMD and normal mucosa of healthy volunteers. Our data showed that expression patterns of molecular biomarkers were not notably different between sporadic and FA-OSCC cell lines. The p-BNC assay revealed significant differences in cytometric parameters and biomarker MCM2 expression between cytobrush samples of the FA patient and cytobrush samples of normal oral mucosa obtained from healthy volunteers. Microscopic examination of the FA patient's OPMD confirmed the presence of dysplasia. Our pilot data suggests that the p-BNC brush biopsy test recognized dysplastic oral epithelial cells in a brush biopsy sample of a FA patient. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. The Fanconi anemia associated protein FAAP24 uses two substrate specific binding surfaces for DNA recognition.

    PubMed

    Wienk, Hans; Slootweg, Jack C; Speerstra, Sietske; Kaptein, Robert; Boelens, Rolf; Folkers, Gert E

    2013-07-01

    To maintain the integrity of the genome, multiple DNA repair systems exist to repair damaged DNA. Recognition of altered DNA, including bulky adducts, pyrimidine dimers and interstrand crosslinks (ICL), partially depends on proteins containing helix-hairpin-helix (HhH) domains. To understand how ICL is specifically recognized by the Fanconi anemia proteins FANCM and FAAP24, we determined the structure of the HhH domain of FAAP24. Although it resembles other HhH domains, the FAAP24 domain contains a canonical hairpin motif followed by distorted motif. The HhH domain can bind various DNA substrates; using nuclear magnetic resonance titration experiments, we demonstrate that the canonical HhH motif is required for double-stranded DNA (dsDNA) binding, whereas the unstructured N-terminus can interact with single-stranded DNA. Both DNA binding surfaces are used for binding to ICL-like single/double-strand junction-containing DNA substrates. A structural model for FAAP24 bound to dsDNA has been made based on homology with the translesion polymerase iota. Site-directed mutagenesis, sequence conservation and charge distribution support the dsDNA-binding model. Analogous to other HhH domain-containing proteins, we suggest that multiple FAAP24 regions together contribute to binding to single/double-strand junction, which could contribute to specificity in ICL DNA recognition.

  10. Hypoxic Stress Facilitates Acute Activation and Chronic Down-Regulation of Fanconi Anemia Proteins

    PubMed Central

    Scanlon, Susan E.; Glazer, Peter M.

    2014-01-01

    Hypoxia induces genomic instability through replication stress and dysregulation of vital DNA repair pathways. The Fanconi anemia (FA) proteins, FANCD2 and FANCI, are key members of a DNA repair pathway that responds to replicative stress, suggesting that they undergo regulation by hypoxic conditions. Here acute hypoxic stress activates the FA pathway via ubiquitination of FANCD2 and FANCI in an ATR-dependent manner. In addition, the presence of an intact FA pathway is required for preventing hypoxia-induced DNA damage measurable by the comet assay, limiting the accumulation of γH2AX (a marker of DNA damage or stalled replication), and protecting cells from hypoxia-induced apoptosis. Furthermore, prolonged hypoxia induces transcriptional repression of FANCD2 in a manner analogous to the hypoxic down-regulation of BRCA1 and RAD51. Thus, hypoxia-induced FA pathway activation plays a key role in maintaining genome integrity and cell survival, while FA protein down-regulation with prolonged hypoxia contributes to genomic instability. PMID:24688021

  11. Second allogeneic hematopoietic cell transplantation for Patients with Fanconi anemia and Bone Marrow Failure

    PubMed Central

    Ayas, Mouhab; Eapen, Mary; Le-Rademacher, Jennifer; Carreras, Jeanette; Abdel-Azim, Hisham; Alter, Blanche P.; Anderlini, Paolo; Battiwalla, Minoo; Bierings, Marc; Buchbinder, David K.; Bonfim, Carmem; Camitta, Bruce M.; Fasth, Anders L.; Gale, Robert Peter; Lee, Michelle A.; Lund, Troy C.; Myers, Kasiani C.; Olsson, Richard F.; Page, Kristin M.; Prestidge, Tim D.; Radhi, Mohamed; Shah, Ami J.; Schultz, Kirk R.; Wirk, Baldeep; Wagner, John E.; Deeg, H. Joachim

    2015-01-01

    Second allogeneic hematopoietic cell transplantation (HCT) is the only salvage option for those for develop graft failure after their first HCT. Data on outcomes after second HCT in Fanconi anemia (FA) are scarce. We report outcomes after second allogeneic HCT for FA (n=81). The indication for second HCT was graft failure after the first HCT. Transplants occurred between 1990 and 2012. The timing of second transplantation predicted subsequent graft failure and survival. Graft failure was high when the second transplant occurred less than 3 months from the first. The 3-month probability of graft failure was 69% when the interval between first and second transplant was less than 3 months compared to 23% when the interval was longer (p<0.001). Consequently, survival rates were substantially lower when the interval between first and second transplant was less than 3 months, 23% at 1-year compared to 58%, when the interval was longer (p=0.001). The corresponding 5-year probabilities of survival were 16% and 45%, respectively (p=0.006). Taken together, these data suggest that fewer than half of FA patients undergoing a second HCT for graft failure are long-term survivors. There is an urgent need to develop strategies to lower graft failure after first HCT. PMID:26116087

  12. The Fanconi Anemia Pathway Protects Genome Integrity from R-loops

    PubMed Central

    García-Rubio, María L.; Pérez-Calero, Carmen; Barroso, Sonia I.; Tumini, Emanuela; Herrera-Moyano, Emilia; Rosado, Iván V.; Aguilera, Andrés

    2015-01-01

    Co-transcriptional RNA-DNA hybrids (R loops) cause genome instability. To prevent harmful R loop accumulation, cells have evolved specific eukaryotic factors, one being the BRCA2 double-strand break repair protein. As BRCA2 also protects stalled replication forks and is the FANCD1 member of the Fanconi Anemia (FA) pathway, we investigated the FA role in R loop-dependent genome instability. Using human and murine cells defective in FANCD2 or FANCA and primary bone marrow cells from FANCD2 deficient mice, we show that the FA pathway removes R loops, and that many DNA breaks accumulated in FA cells are R loop-dependent. Importantly, FANCD2 foci in untreated and MMC-treated cells are largely R loop dependent, suggesting that the FA functions at R loop-containing sites. We conclude that co-transcriptional R loops and R loop-mediated DNA damage greatly contribute to genome instability and that one major function of the FA pathway is to protect cells from R loops. PMID:26584049

  13. Hypomutability in Fanconi anemia cells is associated with increased deletion frequency at the HPRT locus

    SciTech Connect

    Papadopoulo, D.; Guillouf, C.; Moustacchi, E. ); Mohrenweiser, H. )

    1990-11-01

    Fanconi anemia (FA) is an inherited human disorder associated with a predisposition to cancer and characterized by anomalies in the processing of DNA cross-links and certain monoadducts. The authors reported previously that the frequency of psoralen-photoinduced mutations at the HPRT locus is lower in FA cells than in normal cells. This hypomutability is shown here to be associated with an increased frequency of deletions in the HPRT gene when either a mixture of cross-links and monoadducts or monoadducts alone are induced. Molecular analysis of mutants in the HPRT gene was carried out. In normal cells the majority of spontaneous and induced mutants are point mutations whereas in FA deletion mutations predominate. In that case a majority of mutants were found to lack individual exons or small clusters of exons whereas in normal cells large (complete or major gene loss) and small deletions are almost equally represented. Thus they propose that the FA defect lies in a mutagenic pathway that, in normal cells, involves by passing lesions and subsequent gap filling by a recombinational process during replication.

  14. BRCA/Fanconi anemia pathway implicates chemoresistance to gemcitabine in biliary tract cancer.

    PubMed

    Nakashima, Shinsuke; Kobayashi, Shogo; Nagano, Hiroaki; Tomokuni, Akira; Tomimaru, Yoshito; Asaoka, Tadafumi; Hama, Naoki; Wada, Hiroshi; Kawamoto, Koichi; Marubashi, Shigeru; Eguchi, Hidetoshi; Doki, Yuichiro; Mori, Masaki

    2015-05-01

    The BRCA/Fanconi anemia (FA) pathway plays a key role in the repair of DNA double strand breaks. We focused on this pathway to clarify chemoresistance mechanisms in biliary tract cancer (BTC). We also investigated changes in the CD24(+)/44(+) population that may be involved in chemoresistance, as this population likely includes cancer stem cells. We used three BTC cell lines to establish gemcitabine (GEM)-resistant (GR) cells and evaluated the expression of BRCA/FA pathway components, chemoresistance, and the effect of BRCA/FA pathway inhibition on the CD24(+)/44(+) population. FANCD2 and CD24 expression were evaluated in 108 resected BTC specimens. GR cells highly expressed the BRCA/FA components. The BRCA/FA pathway was upregulated by GEM and cisplatin (CDDP) exposure. Inhibition using siRNA and RAD51 inhibitor sensitized GR cells to GEM or CDDP. The CD24(+)/44(+) population was increased in GR and parent BTC cells treated with GEM or CDDP and highly expressed BRCA/FA genes. FANCD2 was related to CD24 expression in resected BTC specimens. Inhibition of the BRCA/FA pathway under GEM reduced the CD24(+)/44(+) population in MzChA1-GR cells. Thus, high expression of the BRCA/FA pathway is one mechanism of chemoresistance against GEM and/or CDDP and is related to the CD24(+)/44(+) population in BTC.

  15. Structural analysis of human FANCL, the E3 ligase in the Fanconi anemia pathway.

    PubMed

    Hodson, Charlotte; Cole, Ambrose R; Lewis, Laurence P C; Miles, Jennifer A; Purkiss, Andrew; Walden, Helen

    2011-09-16

    The Fanconi anemia (FA) pathway is essential for the repair of DNA interstrand cross-links. At the heart of this pathway is the monoubiquitination of the FANCI-FANCD2 (ID) complex by the multiprotein "core complex" containing the E3 ubiquitin ligase FANCL. Vertebrate organisms have the eight-protein core complex, whereas invertebrates apparently do not. We report here the structure of the central domain of human FANCL in comparison with the recently solved Drosophila melanogaster FANCL. Our data represent the first structural detail into the catalytic core of the human system and reveal that the central fold of FANCL is conserved between species. However, there are macromolecular differences between the FANCL proteins that may account for the apparent distinctions in core complex requirements between the vertebrate and invertebrate FA pathways. In addition, we characterize the binding of human FANCL with its partners, Ube2t, FANCD2, and FANCI. Mutational analysis reveals which residues are required for substrate binding, and we also show the domain required for E2 binding.

  16. Ubiquitin-like protein UBL5 promotes the functional integrity of the Fanconi anemia pathway.

    PubMed

    Oka, Yasuyoshi; Bekker-Jensen, Simon; Mailand, Niels

    2015-05-12

    Ubiquitin and ubiquitin-like proteins (UBLs) function in a wide array of cellular processes. UBL5 is an atypical UBL that does not form covalent conjugates with cellular proteins and which has a known role in modulating pre-mRNA splicing. Here, we report an unexpected involvement of human UBL5 in promoting the function of the Fanconi anemia (FA) pathway for repair of DNA interstrand crosslinks (ICLs), mediated by a specific interaction with the central FA pathway component FANCI. UBL5-deficient cells display spliceosome-independent reduction of FANCI protein stability, defective FANCI function in response to DNA damage and hypersensitivity to ICLs. By mapping the sequence determinants underlying UBL5-FANCI binding, we generated separation-of-function mutants to demonstrate that key aspects of FA pathway function, including FANCI-FANCD2 heterodimerization, FANCD2 and FANCI monoubiquitylation and maintenance of chromosome stability after ICLs, are compromised when the UBL5-FANCI interaction is selectively inhibited by mutations in either protein. Together, our findings establish UBL5 as a factor that promotes the functionality of the FA DNA repair pathway.

  17. Co-opting the Fanconi anemia genomic stability pathway enables herpesvirus DNA synthesis and productive growth.

    PubMed

    Karttunen, Heidi; Savas, Jeffrey N; McKinney, Caleb; Chen, Yu-Hung; Yates, John R; Hukkanen, Veijo; Huang, Tony T; Mohr, Ian

    2014-07-03

    DNA damage associated with viral DNA synthesis can result in double-strand breaks that threaten genome integrity and must be repaired. Here, we establish that the cellular Fanconi anemia (FA) genomic stability pathway is exploited by herpes simplex virus 1 (HSV-1) to promote viral DNA synthesis and enable its productive growth. Potent FA pathway activation in HSV-1-infected cells resulted in monoubiquitination of FA effector proteins FANCI and FANCD2 (FANCI-D2) and required the viral DNA polymerase. FANCD2 relocalized to viral replication compartments, and FANCI-D2 interacted with a multisubunit complex containing the virus-encoded single-stranded DNA-binding protein ICP8. Significantly, whereas HSV-1 productive growth was impaired in monoubiquitination-defective FA cells, this restriction was partially surmounted by antagonizing the DNA-dependent protein kinase (DNA-PK), a critical enzyme required for nonhomologous end-joining (NHEJ). This identifies the FA-pathway as a cellular factor required for herpesvirus productive growth and suggests that FA-mediated suppression of NHEJ is a fundamental step in the viral life cycle.

  18. Fanconi anemia proteins FANCD2 and FANCI exhibit different DNA damage responses during S-phase.

    PubMed

    Sareen, Archana; Chaudhury, Indrajit; Adams, Nicole; Sobeck, Alexandra

    2012-09-01

    Fanconi anemia (FA) pathway members, FANCD2 and FANCI, contribute to the repair of replication-stalling DNA lesions. FA pathway activation relies on phosphorylation of FANCI by the ataxia telangiectasia and Rad3-related (ATR) kinase, followed by monoubiquitination of FANCD2 and FANCI by the FA core complex. FANCD2 and FANCI are thought to form a functional heterodimer during DNA repair, but it is unclear how dimer formation is regulated or what the functions of the FANCD2-FANCI complex versus the monomeric proteins are. We show that the FANCD2-FANCI complex forms independently of ATR and FA core complex, and represents the inactive form of both proteins. DNA damage-induced FA pathway activation triggers dissociation of FANCD2 from FANCI. Dissociation coincides with FANCD2 monoubiquitination, which significantly precedes monoubiquitination of FANCI; moreover, monoubiquitination responses of FANCD2 and FANCI exhibit distinct DNA substrate specificities. A phosphodead FANCI mutant fails to dissociate from FANCD2, whereas phosphomimetic FANCI cannot interact with FANCD2, indicating that FANCI phosphorylation is the molecular trigger for FANCD2-FANCI dissociation. Following dissociation, FANCD2 binds replicating chromatin prior to-and independently of-FANCI. Moreover, the concentration of chromatin-bound FANCD2 exceeds that of FANCI throughout replication. Our results suggest that FANCD2 and FANCI function separately at consecutive steps during DNA repair in S-phase.

  19. Activation of the Fanconi anemia/BRCA pathway at low doses of ionization radiation.

    PubMed

    Bosch, Pau Castillo; Bogliolo, Massimo; Surrallés, Jordi

    2015-11-01

    Fanconi anemia (FA) is a rare, clinically heterogeneous autosomal recessive or X-linked genetic disease characterized by chromosome fragility, congenital malformations and cancer susceptibility. FA patients are usually radiosensitive when exposed to radiotherapy but the role of the FA in response to ionizing radiation (IR) is controversial. Here we have investigated IR-induced activation of the FA pathway by systematically analyzing monoubiquitination of the central protein FANCD2 and subsequent recruitment to stalled replication forks in primary fibroblasts. We developed an immunolabelling method to simultaneously visualize IR-induced FANCD2 and γH2AX foci in S-phase. We observed FANCD2 foci formation in a subset of IR-induced γH2AX foci in S-phase cells. This was observed at doses of IR ranging from 0.1 to 5.0Gy in a dose dependent non-threshold fashion. Our results indicate that minimum doses of IR can produce replication fork stalling and FA pathway activation during S-phase in primary cells.

  20. The PTEN phosphatase functions cooperatively with the Fanconi anemia proteins in DNA crosslink repair

    PubMed Central

    Vuono, Elizabeth A.; Mukherjee, Ananda; Vierra, David A.; Adroved, Morganne M.; Hodson, Charlotte; Deans, Andrew J.; Howlett, Niall G.

    2016-01-01

    Fanconi anemia (FA) is a genetic disease characterized by bone marrow failure and increased cancer risk. The FA proteins function primarily in DNA interstrand crosslink (ICL) repair. Here, we have examined the role of the PTEN phosphatase in this process. We have established that PTEN-deficient cells, like FA cells, exhibit increased cytotoxicity, chromosome structural aberrations, and error-prone mutagenic DNA repair following exposure to ICL-inducing agents. The increased ICL sensitivity of PTEN-deficient cells is caused, in part, by elevated PLK1 kinase-mediated phosphorylation of FANCM, constitutive FANCM polyubiquitination and degradation, and the consequent inefficient assembly of the FA core complex, FANCD2, and FANCI into DNA repair foci. We also establish that PTEN function in ICL repair is dependent on its protein phosphatase activity and ability to be SUMOylated, yet is independent of its lipid phosphatase activity. Finally, via epistasis analysis, we demonstrate that PTEN and FANCD2 function cooperatively in ICL repair. PMID:27819275

  1. Significance of the Fanconi anemia FANCD2 protein in sporadic and metastatic human breast cancer.

    PubMed

    Rudland, Philip S; Platt-Higgins, Angela M; Davies, Lowri M; de Silva Rudland, Suzete; Wilson, James B; Aladwani, Abdulaziz; Winstanley, John H R; Barraclough, Dong L; Barraclough, Roger; West, Christopher R; Jones, Nigel J

    2010-06-01

    FANCD2, a pivotal protein in the Fanconi anemia and BRCA pathway/network, is monoubiquitylated in the nucleus in response to DNA damage. This study examines the subcellular location and relationship with prognostic factors and patient survival of FANCD2 in breast cancer. Antibodies to FANCD2 were used to immunocytochemically stain 16 benign and 20 malignant breast specimens as well as 314 primary breast carcinomas to assess its association with subcellular compartment and prognostic factors using Fisher's Exact test or with patient survival over 20 years using Wilcoxon-Gehan statistics. Immunoreactive FANCD2 was found in the nucleus and cytoplasm of all 16 benign tissues, but nuclear staining was lost from a significant 19/20 malignant carcinomas (P < 0.0001). Antibodies to FANCD2 stained the cytoplasm of 196 primary carcinomas, leaving 118 as negatively stained. Negative cytoplasmic staining was significantly associated with positive staining for the metastasis-inducing proteins S100A4, S100P, osteopontin, and AGR2 (P < or = 0.002). Survival of patients with FANCD2-negative carcinomas was significantly worse (P < 0.0001) than those with positively stained carcinomas, and only 4% were alive at the census date. Multivariate regression analysis identified negative staining for cytoplasmic FANCD2 as the most significant indicator of patient death (P = 0.001). Thus FANCD2's cytoplasmic loss in the primary carcinomas may allow the selection of cells overexpressing proteins that can induce metastases before surgery.

  2. The Fanconi anemia protein FANCM is controlled by FANCD2 and the ATR/ATM pathways.

    PubMed

    Sobeck, Alexandra; Stone, Stacie; Landais, Igor; de Graaf, Bendert; Hoatlin, Maureen E

    2009-09-18

    Genomic stability requires a functional Fanconi anemia (FA) pathway composed of an upstream "core complex" (FA proteins A/B/C/E/F/G/L/M) that mediates monoubiquitination of the downstream targets FANCD2 and FANCI. Unique among FA core complex members, FANCM has processing activities toward replication-associated DNA structures, suggesting a vital role for FANCM during replication. Using Xenopus egg extracts, we analyzed the functions of FANCM in replication and the DNA damage response. xFANCM binds chromatin in a replication-dependent manner and is phosphorylated in response to DNA damage structures. Chromatin binding and DNA damage-induced phosphorylation of xFANCM are mediated in part by the downstream FA pathway protein FANCD2. Moreover, phosphorylation and chromatin recruitment of FANCM is regulated by two mayor players in the DNA damage response: the cell cycle checkpoint kinases ATR and ATM. Our results indicate that functions of FANCM are controlled by FA- and non-FA pathways in the DNA damage response.

  3. Physical and functional crosstalk between Fanconi anemia core components and the GINS replication complex.

    PubMed

    Tumini, Emanuela; Plevani, Paolo; Muzi-Falconi, Marco; Marini, Federica

    2011-02-07

    Fanconi anemia (FA) is an inherited disease characterized by bone marrow failure, increased cancer risk and hypersensitivity to DNA cross-linking agents, implying a role for this pathway in the maintenance of genomic stability. The central player of the FA pathway is the multi-subunit E3 ubiquitin ligase complex activated through a replication- and DNA damage-dependent mechanism. A consequence of the activation of the complex is the monoubiquitylation of FANCD2 and FANCI, late term effectors in the maintenance of genome integrity. The details regarding the coordination of the FA-dependent response and the DNA replication process are still mostly unknown. We found, by yeast two-hybrid assay and co-immunoprecipitation in human cells, that the core complex subunit FANCF physically interacts with PSF2, a member of the GINS complex essential for both the initiation and elongation steps of DNA replication. In HeLa cells depleted for PSF2, we observed a decreased binding to chromatin of the FA core complex, suggesting that the GINS complex may have a role in either loading or stabilizing the FA core complex onto chromatin. Consistently, GINS and core complex bind chromatin contemporarily upon origin firing and PSF2 depletion sensitizes cells to DNA cross-linking agents. However, depletion of PSF2 is not sufficient to reduce monoubiquitylation of FANCD2 or its localization to nuclear foci following DNA damage. Our results suggest a novel crosstalk between DNA replication and the FA pathway.

  4. Regulation of Fanconi anemia protein FANCD2 monoubiquitination by miR-302.

    PubMed

    Suresh, Bharathi; Kumar, A Madhan; Jeong, Hoe-Su; Cho, Youl-Hee; Ramakrishna, Suresh; Kim, Kye-Seong

    2015-10-16

    Fanconi anemia (FA) is a recessively inherited multigene disease characterized by congenital defects, progressive bone marrow failure, and heightened cancer susceptibility. Monoubiquitination of the FA pathway member FANCD2 contributes to the repair of replication stalling DNA lesions. However, cellular regulation of FANCD2 monoubiquitination remains poorly understood. In the present study, we identified the miR-302 cluster as a potential regulator of FANCD2 by bioinformatics analysis. MicroRNAs (miRNAs) are the major posttranscriptional regulators of a wide variety of biological processes, and have been implicated in a number of diseases. Expression of the exogenous miR-302 cluster (without miR-367) reduced FANCD2 monoubiquitination and nuclear foci formation. Furthermore, miR-302 cells showed extensive chromosomal breakage upon MMC treatment when compared to mock control cells. Taken together, our results suggest that overexpression of miR-302 plays a critical role in the regulation of FANCD2 monoubiquitination, resulting in characteristic defects in DNA repair within cells.

  5. Regulation of the Fanconi anemia pathway by a SUMO-like delivery network.

    PubMed

    Yang, Kailin; Moldovan, George-Lucian; Vinciguerra, Patrizia; Murai, Junko; Takeda, Shunichi; D'Andrea, Alan D

    2011-09-01

    The USP1/UAF1 complex deubiquitinates the Fanconi anemia protein FANCD2, thereby promoting homologous recombination and DNA cross-link repair. How USP1/UAF1 is targeted to the FANCD2/FANCI heterodimer has remained unknown. Here we show that UAF1 contains a tandem repeat of SUMO-like domains in its C terminus (SLD1 and SLD2). SLD2 binds directly to a SUMO-like domain-interacting motif (SIM) on FANCI. Deletion of the SLD2 sequence of UAF1 or mutation of the SIM on FANCI disrupts UAF1/FANCI binding and inhibits FANCD2 deubiquitination and DNA repair. The USP1/UAF1 complex also deubiquitinates PCNA-Ub, and deubiquitination requires the PCNA-binding protein hELG1. The SLD2 sequence of UAF1 binds to a SIM on hELG1, thus targeting the USP1/UAF1 complex to its PCNA-Ub substrate. We propose that the regulated targeting of USP1/UAF1 to its DNA repair substrates, FANCD2-Ub and PCNA-Ub, by SLD-SIM interactions coordinates homologous recombination and translesion DNA synthesis.

  6. ATR-ATRIP kinase complex triggers activation of the Fanconi anemia DNA repair pathway.

    PubMed

    Shigechi, Tomoko; Tomida, Junya; Sato, Koichi; Kobayashi, Masahiko; Eykelenboom, John K; Pessina, Fabio; Zhang, Yanbin; Uchida, Emi; Ishiai, Masamichi; Lowndes, Noel F; Yamamoto, Kenichi; Kurumizaka, Hitoshi; Maehara, Yoshihiko; Takata, Minoru

    2012-03-01

    ATR kinase activates the S-phase checkpoint when replication forks stall at sites of DNA damage. This event also causes phosphorylation of the Fanconi anemia (FA) protein FANCI, triggering its monoubiquitination of the key DNA repair factor FANCD2 by the FA core E3 ligase complex, thereby promoting this central pathway of DNA repair which permits replication to be restarted. However, the interplay between ATR and the FA pathway has been unclear. In this study, we present evidence that their action is directly linked, gaining insights into this relationship in a DT40 mutant cell line that is conditionally deficient in the critical ATR-binding partner protein ATRIP. Using this system, we showed that ATRIP was crucial for DNA damage-induced FANCD2 monoubiquitination and FANCI phosphorylation. ATR kinase phosphorylated recombinant FANCI protein in vitro, which was facilitated by the presence of FANCD2. Mechanistic investigations revealed that the RPA region but not the TopBP1 region of ATRIP was required for FANCD2 monoubiquitination, whereas Chk1 phosphorylation relied upon both domains. Together, our findings identify ATR as the kinase responsible for activating the FA pathway of DNA repair.

  7. Fanconi anemia pathway regulates convergent transcription-induced cell death at trinucleotide repeats in human cells

    PubMed Central

    Chatterjee, Nimrat; Lin, Yunfu; Wilson, John H.

    2016-01-01

    Almost 20 incurable neurodegenerative disorders are caused by trinucleotide repeat (TNR) expansion beyond a certain threshold, with disease time of onset and severity positively correlating with repeat length. Typically, long TNRs display a bias toward further expansion and repeats continue to expand not only during germline transmissions from parents to offspring, but also remain highly unstable in somatic tissues of patients. Hence, understanding TNR instability mechanisms sheds light on underlying disease pathology. Recently, we showed that activated ATR is the major signal for convergent-transcription-induced cell death at CAG repeats and is regulated by the mismatch repair (MMR) pathway. Additionally, components of other DNA repair pathways such as transcription-coupled nucleotide excision repair (TC-NER) and R-loop resolution by RNaseH reduce cell death. Because activated ATR signals the Fanconi anemia (FA) pathway of interstrand crosslink DNA repair, we asked whether the FA pathway also modulates convergent-transcription-induced cell death at expanded CAG repeats. We show here that siRNA knockdown of FA components—FANCI, FANCJ, FANCM, FANCA, and FANCD2—decreases cell death, suggesting that FA proteins, like MMR proteins, are activators of cell death during convergent transcription. PMID:27595121

  8. Genetic variants in fanconi anemia pathway genes BRCA2 and FANCA predict melanoma survival.

    PubMed

    Yin, Jieyun; Liu, Hongliang; Liu, Zhensheng; Wang, Li-E; Chen, Wei V; Zhu, Dakai; Amos, Christopher I; Fang, Shenying; Lee, Jeffrey E; Wei, Qingyi

    2015-02-01

    Cutaneous melanoma (CM) is the most lethal skin cancer. The Fanconi anemia (FA) pathway involved in DNA crosslink repair may affect CM susceptibility and prognosis. Using data derived from published genome-wide association study, we comprehensively analyzed the associations of 2,339 common single-nucleotide polymorphisms (SNPs) in 14 autosomal FA genes with overall survival (OS) in 858 CM patients. By performing false-positive report probability corrections and stepwise Cox proportional hazards regression analyses, we identified significant associations between CM OS and four putatively functional SNPs: BRCA2 rs10492396 (AG vs. GG: adjusted hazard ratio (adjHR)=1.85, 95% confidence interval (CI)=1.16-2.95, P=0.010), rs206118 (CC vs. TT+TC: adjHR=2.44, 95% CI=1.27-4.67, P=0.007), rs3752447 (CC vs. TT+TC: adjHR=2.10, 95% CI=1.38-3.18, P=0.0005), and FANCA rs62068372 (TT vs. CC+CT: adjHR=1.85, 95% CI=1.27-2.69, P=0.001). Moreover, patients with an increasing number of unfavorable genotypes (NUG) of these loci had markedly reduced OS and melanoma-specific survival (MSS). The final model incorporating with NUG, tumor stage, and Breslow thickness showed an improved discriminatory ability to classify both 5-year OS and 5-year MSS. Additional investigations, preferably prospective studies, are needed to validate our findings.

  9. Significance of the Fanconi Anemia FANCD2 Protein in Sporadic and Metastatic Human Breast Cancer

    PubMed Central

    Rudland, Philip S.; Platt-Higgins, Angela M.; Davies, Lowri M.; de Silva Rudland, Suzete; Wilson, James B.; Aladwani, Abdulaziz; Winstanley, John H.R.; Barraclough, Dong L.; Barraclough, Roger; West, Christopher R.; Jones, Nigel J.

    2010-01-01

    FANCD2, a pivotal protein in the Fanconi anemia and BRCA pathway/network, is monoubiquitylated in the nucleus in response to DNA damage. This study examines the subcellular location and relationship with prognostic factors and patient survival of FANCD2 in breast cancer. Antibodies to FANCD2 were used to immunocytochemically stain 16 benign and 20 malignant breast specimens as well as 314 primary breast carcinomas to assess its association with subcellular compartment and prognostic factors using Fisher’s Exact test or with patient survival over 20 years using Wilcoxon-Gehan statistics. Immunoreactive FANCD2 was found in the nucleus and cytoplasm of all 16 benign tissues, but nuclear staining was lost from a significant 19/20 malignant carcinomas (P < 0.0001). Antibodies to FANCD2 stained the cytoplasm of 196 primary carcinomas, leaving 118 as negatively stained. Negative cytoplasmic staining was significantly associated with positive staining for the metastasis-inducing proteins S100A4, S100P, osteopontin, and AGR2 (P ≤ 0.002). Survival of patients with FANCD2-negative carcinomas was significantly worse (P < 0.0001) than those with positively stained carcinomas, and only 4% were alive at the census date. Multivariate regression analysis identified negative staining for cytoplasmic FANCD2 as the most significant indicator of patient death (P = 0.001). Thus FANCD2’s cytoplasmic loss in the primary carcinomas may allow the selection of cells overexpressing proteins that can induce metastases before surgery. PMID:20363922

  10. Replication Protein A (RPA) deficiency activates the Fanconi anemia DNA repair pathway.

    PubMed

    Jang, Seok-Won; Jung, Jin Ki; Kim, Jung Min

    2016-09-01

    The Fanconi anemia (FA) pathway regulates DNA inter-strand crosslink (ICL) repair. Despite our greater understanding of the role of FA in ICL repair, its function in the preventing spontaneous genome instability is not well understood. Here, we show that depletion of replication protein A (RPA) activates the FA pathway. RPA1 deficiency increases chromatin recruitment of FA core complex, leading to FANCD2 monoubiquitination (FANCD2-Ub) and foci formation in the absence of DNA damaging agents. Importantly, ATR depletion, but not ATM, abolished RPA1 depletion-induced FANCD2-Ub, suggesting that ATR activation mediated FANCD2-Ub. Interestingly, we found that depletion of hSSB1/2-INTS3, a single-stranded DNA-binding protein complex, induces FANCD2-Ub, like RPA1 depletion. More interestingly, depletion of either RPA1 or INTS3 caused increased accumulation of DNA damage in FA pathway deficient cell lines. Taken together, these results indicate that RPA deficiency induces activation of the FA pathway in an ATR-dependent manner, which may play a role in the genome maintenance.

  11. Metformin improves defective hematopoiesis and delays tumor formation in Fanconi anemia mice.

    PubMed

    Zhang, Qing-Shuo; Tang, Weiliang; Deater, Matthew; Phan, Ngoc; Marcogliese, Andrea N; Li, Hui; Al-Dhalimy, Muhsen; Major, Angela; Olson, Susan; Monnat, Raymond J; Grompe, Markus

    2016-12-15

    Fanconi anemia (FA) is an inherited bone marrow failure disorder associated with a high incidence of leukemia and solid tumors. Bone marrow transplantation is currently the only curative therapy for the hematopoietic complications of this disorder. However, long-term morbidity and mortality remain very high, and new therapeutics are badly needed. Here we show that the widely used diabetes drug metformin improves hematopoiesis and delays tumor formation in Fancd2(-/-) mice. Metformin is the first compound reported to improve both of these FA phenotypes. Importantly, the beneficial effects are specific to FA mice and are not seen in the wild-type controls. In this preclinical model of FA, metformin outperformed the current standard of care, oxymetholone, by improving peripheral blood counts in Fancd2(-/-) mice significantly faster. Metformin increased the size of the hematopoietic stem cell compartment and enhanced quiescence in hematopoietic stem and progenitor cells. In tumor-prone Fancd2(-/-)Trp53(+/-) mice, metformin delayed the onset of tumors and significantly extended the tumor-free survival time. In addition, we found that metformin and the structurally related compound aminoguanidine reduced DNA damage and ameliorated spontaneous chromosome breakage and radials in human FA patient-derived cells. Our results also indicate that aldehyde detoxification might be one of the mechanisms by which metformin reduces DNA damage in FA cells. © 2016 by The American Society of Hematology.

  12. Hypoxic stress facilitates acute activation and chronic downregulation of fanconi anemia proteins.

    PubMed

    Scanlon, Susan E; Glazer, Peter M

    2014-07-01

    Hypoxia induces genomic instability through replication stress and dysregulation of vital DNA repair pathways. The Fanconi anemia (FA) proteins, FANCD2 and FANCI, are key members of a DNA repair pathway that responds to replicative stress, suggesting that they undergo regulation by hypoxic conditions. Here acute hypoxic stress activates the FA pathway via ubiquitination of FANCD2 and FANCI in an ATR-dependent manner. In addition, the presence of an intact FA pathway is required for preventing hypoxia-induced DNA damage measurable by the comet assay, limiting the accumulation of γH2AX (a marker of DNA damage or stalled replication), and protecting cells from hypoxia-induced apoptosis. Furthermore, prolonged hypoxia induces transcriptional repression of FANCD2 in a manner analogous to the hypoxic downregulation of BRCA1 and RAD51. Thus, hypoxia-induced FA pathway activation plays a key role in maintaining genome integrity and cell survival, while FA protein downregulation with prolonged hypoxia contributes to genomic instability. This work highlights the critical role of the FA pathway in response to hypoxic stress and identifies the pathway as a therapeutic target under hypoxic conditions. ©2014 American Association for Cancer Research.

  13. Sonic Hedgehog, VACTERL, and Fanconi anemia: Pathogenetic connections and therapeutic implications.

    PubMed

    Lubinsky, Mark

    2015-11-01

    Three systems with VACTERL association findings- mutations of the Sonic Hedgehog (SHH) signaling pathway in mice, murine adriamycin teratogenicity, and human Fanconi anemia (FA) pathway mutations, may all involve a similar mechanism. SHH is up-regulated in irradiated cells, and DNA breaks common with radiation damage in the adriamycin and FA systems are plausible signals for such effects, which would affect development. Since FA related DNA breakage occurs throughout life, SHH disturbances may account for later FA related findings involving hematopoietic and malignancy issues. In support, androgen, a standard treatment for FA hematologic failure, down-regulates SHH, and common FA malignancies such as squamous cell carcinomas and acute myeloid leukemia have been linked to enhanced SHH function. This suggests that interventions lowering SHH levels may be useful therapeutically. Also supporting a connection between pre- and post- natal findings, the frequency and number of VACTERL anomalies with FA correlate with the severity and onset of hematopoietic and malignancy issues. In FA, radial anomalies are the most common of these defects, followed by renal findings, while vertebral and gastrointestinal anomalies are relatively uncommon, a pattern that differs from observations of the VACTERL association. Genes with more severe effects also show a greatly increased incidence of brain abnormalities, and a paucity of such findings with other FA genes suggests that brain development is relatively refractory to SHH related effects, accounting for the rarity of such findings with the association.

  14. The nuclear accumulation of the Fanconi anemia protein FANCE depends on FANCC.

    PubMed

    Léveillé, France; Ferrer, Miriam; Medhurst, Annette L; Laghmani, El Houari; Rooimans, Martin A; Bier, Patrick; Steltenpool, Jurgen; Titus, Tom A; Postlethwait, John H; Hoatlin, Maureen E; Joenje, Hans; de Winter, Johan P

    2006-05-10

    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.

  15. Lentiviral-mediated Genetic Correction of Hematopoietic and Mesenchymal Progenitor Cells From Fanconi Anemia Patients.

    PubMed

    Jacome, Ariana; Navarro, Susana; Río, Paula; Yañez, Rosa M; González-Murillo, Africa; Luz Lozano, M; Lamana, Maria Luisa; Sevilla, Julian; Olive, Teresa; Diaz-Heredia, Cristina; Badell, Isabel; Estella, Jesus; Madero, Luis; Guenechea, Guillermo; Casado, José; Segovia, Jose C; Bueren, Juan A

    2009-06-01

    Previous clinical trials based on the genetic correction of purified CD34(+) cells with γ-retroviral vectors have demonstrated clinical efficacy in different monogenic diseases, including X-linked severe combined immunodeficiency, adenosine deaminase deficient severe combined immunodeficiency and chronic granulomatous disease. Similar protocols, however, failed to engraft Fanconi anemia (FA) patients with genetically corrected cells. In this study, we first aimed to correlate the hematological status of 27 FA patients with CD34(+) cell values determined in their bone marrow (BM). Strikingly, no correlation between these parameters was observed, although good correlations were obtained when numbers of colony-forming cells (CFCs) were considered. Based on these results, and because purified FA CD34(+) cells might have suboptimal repopulating properties, we investigated the possibility of genetically correcting unselected BM samples from FA patients. Our data show that the lentiviral transduction of unselected FA BM cells mediates an efficient phenotypic correction of hematopoietic progenitor cells and also of CD34(-) mesenchymal stromal cells (MSCs), with a reported role in hematopoietic engraftment. Our results suggest that gene therapy protocols appropriate for the treatment of different monogenic diseases may not be adequate for stem cell diseases like FA. We propose a new approach for the gene therapy of FA based on the rapid transduction of unselected hematopoietic grafts with lentiviral vectors (LVs).

  16. Lentiviral-mediated genetic correction of hematopoietic and mesenchymal progenitor cells from Fanconi anemia patients.

    PubMed

    Jacome, Ariana; Navarro, Susana; Río, Paula; Yañez, Rosa M; González-Murillo, Africa; Lozano, M Luz; Lamana, Maria Luisa; Sevilla, Julian; Olive, Teresa; Diaz-Heredia, Cristina; Badell, Isabel; Estella, Jesus; Madero, Luis; Guenechea, Guillermo; Casado, José; Segovia, Jose C; Bueren, Juan A

    2009-06-01

    Previous clinical trials based on the genetic correction of purified CD34(+) cells with gamma-retroviral vectors have demonstrated clinical efficacy in different monogenic diseases, including X-linked severe combined immunodeficiency, adenosine deaminase deficient severe combined immunodeficiency and chronic granulomatous disease. Similar protocols, however, failed to engraft Fanconi anemia (FA) patients with genetically corrected cells. In this study, we first aimed to correlate the hematological status of 27 FA patients with CD34(+) cell values determined in their bone marrow (BM). Strikingly, no correlation between these parameters was observed, although good correlations were obtained when numbers of colony-forming cells (CFCs) were considered. Based on these results, and because purified FA CD34(+) cells might have suboptimal repopulating properties, we investigated the possibility of genetically correcting unselected BM samples from FA patients. Our data show that the lentiviral transduction of unselected FA BM cells mediates an efficient phenotypic correction of hematopoietic progenitor cells and also of CD34(-) mesenchymal stromal cells (MSCs), with a reported role in hematopoietic engraftment. Our results suggest that gene therapy protocols appropriate for the treatment of different monogenic diseases may not be adequate for stem cell diseases like FA. We propose a new approach for the gene therapy of FA based on the rapid transduction of unselected hematopoietic grafts with lentiviral vectors (LVs).

  17. Lentiviral-mediated Genetic Correction of Hematopoietic and Mesenchymal Progenitor Cells From Fanconi Anemia Patients

    PubMed Central

    Jacome, Ariana; Navarro, Susana; Río, Paula; Yañez, Rosa M; González-Murillo, Africa; Luz Lozano, M; Lamana, Maria Luisa; Sevilla, Julian; Olive, Teresa; Diaz-Heredia, Cristina; Badell, Isabel; Estella, Jesus; Madero, Luis; Guenechea, Guillermo; Casado, José; Segovia, Jose C; Bueren, Juan A

    2009-01-01

    Previous clinical trials based on the genetic correction of purified CD34+ cells with γ-retroviral vectors have demonstrated clinical efficacy in different monogenic diseases, including X-linked severe combined immunodeficiency, adenosine deaminase deficient severe combined immunodeficiency and chronic granulomatous disease. Similar protocols, however, failed to engraft Fanconi anemia (FA) patients with genetically corrected cells. In this study, we first aimed to correlate the hematological status of 27 FA patients with CD34+ cell values determined in their bone marrow (BM). Strikingly, no correlation between these parameters was observed, although good correlations were obtained when numbers of colony-forming cells (CFCs) were considered. Based on these results, and because purified FA CD34+ cells might have suboptimal repopulating properties, we investigated the possibility of genetically correcting unselected BM samples from FA patients. Our data show that the lentiviral transduction of unselected FA BM cells mediates an efficient phenotypic correction of hematopoietic progenitor cells and also of CD34− mesenchymal stromal cells (MSCs), with a reported role in hematopoietic engraftment. Our results suggest that gene therapy protocols appropriate for the treatment of different monogenic diseases may not be adequate for stem cell diseases like FA. We propose a new approach for the gene therapy of FA based on the rapid transduction of unselected hematopoietic grafts with lentiviral vectors (LVs). PMID:19277017

  18. ATM-dependent Phosphorylation of the Fanconi Anemia Protein PALB2 Promotes the DNA Damage Response.

    PubMed

    Guo, Yingying; Feng, Wanjuan; Sy, Shirley M H; Huen, Michael S Y

    2015-11-13

    The Fanconi anemia protein PALB2, also known as FANCN, protects genome integrity by regulating DNA repair and cell cycle checkpoints. Exactly how PALB2 functions may be temporally coupled with detection and signaling of DNA damage is not known. Intriguingly, we found that PALB2 is transformed into a hyperphosphorylated state in response to ionizing radiation (IR). IR treatment specifically triggered PALB2 phosphorylation at Ser-157 and Ser-376 in manners that required the master DNA damage response kinase Ataxia telangiectasia mutated, revealing potential mechanistic links between PALB2 and the Ataxia telangiectasia mutated-dependent DNA damage responses. Consistently, dysregulated PALB2 phosphorylation resulted in sustained activation of DDRs. Full-blown PALB2 phosphorylation also required the breast and ovarian susceptible gene product BRCA1, highlighting important roles of the BRCA1-PALB2 interaction in orchestrating cellular responses to genotoxic stress. In summary, our phosphorylation analysis of tumor suppressor protein PALB2 uncovers new layers of regulatory mechanisms in the maintenance of genome stability and tumor suppression. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Hypersensitivities for Acetaldehyde and Other Agents among Cancer Cells Null for Clinically Relevant Fanconi Anemia Genes

    PubMed Central

    Ghosh, Soma; Sur, Surojit; Yerram, Sashidhar R.; Rago, Carlo; Bhunia, Anil K.; Hossain, M. Zulfiquer; Paun, Bogdan C.; Ren, Yunzhao R.; Iacobuzio-Donahue, Christine A.; Azad, Nilofer A.; Kern, Scott E.

    2014-01-01

    Large-magnitude numerical distinctions (>10-fold) among drug responses of genetically contrasting cancers were crucial for guiding the development of some targeted therapies. Similar strategies brought epidemiological clues and prevention goals for genetic diseases. Such numerical guides, however, were incomplete or low magnitude for Fanconi anemia pathway (FANC) gene mutations relevant to cancer in FANC-mutation carriers (heterozygotes). We generated a four-gene FANC-null cancer panel, including the engineering of new PALB2/FANCN-null cancer cells by homologous recombination. A characteristic matching of FANCC-null, FANCG-null, BRCA2/FANCD1-null, and PALB2/FANCN-null phenotypes was confirmed by uniform tumor regression on single-dose cross-linker therapy in mice and by shared chemical hypersensitivities to various inter-strand cross-linking agents and γ-radiation in vitro. Some compounds, however, had contrasting magnitudes of sensitivity; a strikingly high (19- to 22-fold) hypersensitivity was seen among PALB2-null and BRCA2-null cells for the ethanol metabolite, acetaldehyde, associated with widespread chromosomal breakage at a concentration not producing breaks in parental cells. Because FANC-defective cancer cells can share or differ in their chemical sensitivities, patterns of selective hypersensitivity hold implications for the evolutionary understanding of this pathway. Clinical decisions for cancer-relevant prevention and management of FANC-mutation carriers could be modified by expanded studies of high-magnitude sensitivities. PMID:24200853

  20. Regulation of Fanconi anemia protein FANCD2 monoubiquitination by miR-302

    SciTech Connect

    Suresh, Bharathi; Kumar, A. Madhan; Jeong, Hoe-Su; Cho, Youl-Hee; Ramakrishna, Suresh; Kim, Kye-Seong

    2015-10-16

    Fanconi anemia (FA) is a recessively inherited multigene disease characterized by congenital defects, progressive bone marrow failure, and heightened cancer susceptibility. Monoubiquitination of the FA pathway member FANCD2 contributes to the repair of replication stalling DNA lesions. However, cellular regulation of FANCD2 monoubiquitination remains poorly understood. In the present study, we identified the miR-302 cluster as a potential regulator of FANCD2 by bioinformatics analysis. MicroRNAs (miRNAs) are the major posttranscriptional regulators of a wide variety of biological processes, and have been implicated in a number of diseases. Expression of the exogenous miR-302 cluster (without miR-367) reduced FANCD2 monoubiquitination and nuclear foci formation. Furthermore, miR-302 cells showed extensive chromosomal breakage upon MMC treatment when compared to mock control cells. Taken together, our results suggest that overexpression of miR-302 plays a critical role in the regulation of FANCD2 monoubiquitination, resulting in characteristic defects in DNA repair within cells. - Highlights: • miR-302 binds to the 3′UTR promoter of the FANCD2 gene to regulate gene expression. • miR-302 cluster down-regulates FANCD2 protein expression. • miR-302 cluster reduces FANCD2 monoubiquitination and nuclear foci formation. • miR-302 exhibits the characteristic defects in DNA repair in cells.

  1. Effect of Repeated Antimicrobial Photodynamic Therapy in Treatment of Periodontitis Associated with Fanconi Anemia.

    PubMed

    Pavlič, Alenka; Matoh, Urban; Rajić, Vladan; Petelin, Milan

    2017-01-01

    Periodontal disease is one of common oral manifestations in patients with Fanconi anemia (FA). The aim of the study was to evaluate the effect of photodynamic therapy (PDT) on periodontal clinical and microbial parameters in a patient with FA. For a 16-year-old girl, diagnosed with having FA and periodontal disease, the protocol treatment with duration of 10 months was designed. Every 2 months, thorough oral cavity disinfection was followed by PDT, using photosensitizer phenothiazine chloride activated by a diode laser light. During each visit, periodontal parameters were evaluated: plaque index (PI), gingival index (GI), probing pocket depth (PPD), bleeding on probing (BOP), and clinical attachment level. Simultaneously, the presence of Candida albicans and of five periodontal pathogens was evaluated. Clinical results showed improvement in GI, BOP, and PPD during this 10-month period. BOP subsequently reduced from 100% to 79%, 72%, and 60% at 6, 8, and 10 months, respectively. The proportion of sites with PPD of ≥4 mm decreased from 38.7% at the baseline to zero after 10 months. Further, all five bacterial species and C. albicans were reduced significantly. PDT effectively influences periodontal healing and reduces periodontopathogenic bacteria without damaging the patient's tissues.

  2. Structural Analysis of Human FANCL, the E3 Ligase in the Fanconi Anemia Pathway*

    PubMed Central

    Hodson, Charlotte; Cole, Ambrose R.; Lewis, Laurence P. C.; Miles, Jennifer A.; Purkiss, Andrew; Walden, Helen

    2011-01-01

    The Fanconi anemia (FA) pathway is essential for the repair of DNA interstrand cross-links. At the heart of this pathway is the monoubiquitination of the FANCI-FANCD2 (ID) complex by the multiprotein “core complex” containing the E3 ubiquitin ligase FANCL. Vertebrate organisms have the eight-protein core complex, whereas invertebrates apparently do not. We report here the structure of the central domain of human FANCL in comparison with the recently solved Drosophila melanogaster FANCL. Our data represent the first structural detail into the catalytic core of the human system and reveal that the central fold of FANCL is conserved between species. However, there are macromolecular differences between the FANCL proteins that may account for the apparent distinctions in core complex requirements between the vertebrate and invertebrate FA pathways. In addition, we characterize the binding of human FANCL with its partners, Ube2t, FANCD2, and FANCI. Mutational analysis reveals which residues are required for substrate binding, and we also show the domain required for E2 binding. PMID:21775430

  3. Targeting the Fanconi Anemia/BRCA Pathway Circumvents Drug Resistance in Multiple Myeloma

    PubMed Central

    Yarde, Danielle N.; Oliveira, Vasco; Mathews, Linda; Wang, Xingyu; Villagra, Alejandro; Boulware, David; Shain, Kenneth H.; Hazlehurst, Lori A.; Alsina, Melissa; Chen, Dung-Tsa; Beg, Amer A.; Dalton, William S.

    2015-01-01

    The Fanconi Anemia (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 (MM) 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-κB subunits, RelB/p50, as transcriptional activators of the FA/BRCA pathway. Specifically, our findings point to constitutive phosphorylation of IκB Kinase IKKα and subsequent alterations in FANCD2 expression and function as underlying events leading to melphalan resistance in repeatedly exposed MM cells. Inhibiting NF-κB by siRNA, blocking the IKK 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-κB transcriptionally regulates the FA/BRCA pathway, and provide evidence for targeting FA-mediated DNA repair to enhance chemotherapeutic response and circumvent drug resistance in myeloma patients. PMID:19934314

  4. Co-opting the Fanconi Anemia Genomic Stability Pathway Enables Herpesvirus DNA Synthesis and Productive Growth

    PubMed Central

    Karttunen, Heidi; Savas, Jeffrey N.; McKinney, Caleb; Chen, Yu-Hung; Yates, John R.; Hukkanen, Veijo; Huang, Tony T.; Mohr, Ian

    2015-01-01

    SUMMARY DNA damage associated with viral DNA synthesis can result in double strand breaks that threaten genome integrity and must be repaired. Here, we establish that the cellular Fanconi Anemia (FA) genomic stability pathway is exploited by HSV1 to promote viral DNA synthesis and enable its productive growth. Potent FA pathway activation in HSV1-infected cells resulted in monoubiquitination of FA effector proteins, FANCI and FANCD2 (FANCI-D2) and required the viral DNA polymerase. FANCD2 relocalized to viral replication compartments and FANCI-D2 interacted with a multi-subunit complex containing the virus-encoded single-stranded DNA-binding protein ICP8. Significantly, while HSV1 productive growth was impaired in monoubiquitination-defective FA patient cells, this restriction was partially surmounted by antagonizing the DNA-dependent protein kinase (DNA-PK), a critical enzyme required for non-homologous end-joining (NHEJ). This identifies the FA-pathway as a new cellular factor required for herpesvirus productive growth and suggests that FA-mediated suppression of NHEJ is a fundamental step in the viral lifecycle. PMID:24954902

  5. Fanconi Syndrome Secondary to Deferasirox in Diamond-Blackfan Anemia: Case Series and Recommendations for Early Diagnosis.

    PubMed

    Papneja, Koyelle; Bhatt, Mihir D; Kirby-Allen, Melanie; Arora, Steven; Wiernikowski, John T; Athale, Uma H

    2016-08-01

    Deferasirox is an oral iron chelator used to treat patients with transfusion-related iron overload. We report, from two institutions, two children with Diamond-Blackfan anemia who developed Fanconi syndrome secondary to deferasirox administration, along with a review of the literature. The current recommendation for the laboratory monitoring of patients receiving deferasirox does not include serum electrolytes or urine analysis. Thus, despite routine clinic visits and bloodwork, these two patients presented with life-threatening electrolyte abnormalities requiring hospitalization. Hence, we propose the inclusion of serum electrolytes and urine analysis as part of routine monitoring to facilitate the early diagnosis of Fanconi syndrome in the context of high doses of deferasirox therapy. © 2016 Wiley Periodicals, Inc.

  6. Evidence for a founder effect for the IVS4 +4 A{r_arrow}T mutation in the Fanconi anemia gene FACC in a Jewish population

    SciTech Connect

    Verlander, P.C.; Kaporis, A.G.; Qian, L.

    1994-09-01

    Fanconi anemia (FA) is a genetically heterogeneous autosomal recessive disorder defined by hypersensitivity of cells to DNA cross-linking agents; a gene for complementation group C(FACC) has been cloned. Two common mutations, IVS4 +4 A{r_arrow}T and 322delG, and several rare mutations have recently been reported in affected individuals. We now report the development of amplification refractory mutation system (ARMS) assays for rapid, non-radioactive detection of these known mutations in FACC. Primer pairs specific for variant sequences were designed, with the 3{prime} terminal base of one primer matching the variant base. PCR products are separated by electrophoresis on 2.5% agarose gels; mutations are indicated by the presence of a band of a specific size. These ARMS assays can be multiplexed to allow screening for all known mutations in two PCR reactions. We have used these assays for detection of FACC mutations in affected individuals in the International Fanconi Anemia Registry (IFAR), and for carrier detection FACC families. IVS4 +4 A{r_arrow}T is the only FACC mutation found in Jewish FA patients and their families, of both Ashkenazi and Sephardic ancestry. This mutation was not found in any affected individual of non-Jewish origin. In addition, DNA samples from 1596 healthy Jewish individuals primarily of Ashkenazi ancestry were supplied to us by Dor Yeshorim. These samples, ascertained for carrier screening for Tay Sachs, cystic fibrosis, and other genetic diseases with a high frequency in the religious Jewish community served by this organization, were tested for both IVS4 +4 A{r_arrow}T and 322delG mutations; seventeen IVS4 +4 A{r_arrow}T are of Sephardic Jewish ancestry. We hypothesize that IVS4 +4 A{r_arrow}T is a very old mutation, predating the divergence of the Ashkenazi and Sephardic populations. Haplotype analysis with microsatellite markers is in progress.

  7. Irreversible repression of DNA synthesis in Fanconi anemia cells is alleviated by the product of a novel cyclin-related gene.

    PubMed Central

    Digweed, M; Günthert, U; Schneider, R; Seyschab, H; Friedl, R; Sperling, K

    1995-01-01

    Primary fibroblasts from patients with the genetic disease Fanconi anemia, which are hypersensitive to cross-linking agents, were used to screen a cDNA library for sequences involved in their abnormal cellular response to a cross-linking challenge. By using library partition and microinjection of in vitro-transcribed RNA, a cDNA clone, pSPHAR (S-phase response), which is able to correct the permanent repression of semiconservative DNA synthesis rates characteristic of these cells, was isolated. Wild-type SPHAR mRNA is expressed in all fibroblasts so far analyzed, including those of Fanconi anemia patients. Correction of the abnormal response in these cells appears therefore to be due to overexpression after cDNA transfer rather than to genetic complementation. The cDNA contains an open reading frame coding for a polypeptide of 7.5 kDa. Rabbit antiserum directed against a SPHAR peptide detects a protein of 7.9 kDa in Western blots (immunoblots) of whole-cell extracts from proliferating, but not resting, fibroblasts. The deduced amino acid sequence of SPHAR contains a motif found in the cyclins, and it is proposed that SPHAR acts within the injected cell by interfering with the cyclin-controlled maintenance of S phase. In agreement with this proposal, normal cells transfected with an antisense SPHAR expression vector have a significantly reduced rate of DNA synthesis during S phase and a prolonged G2 phase, reflecting the need for postreplicative DNA processing before entry into mitosis. PMID:7799938

  8. Defining the molecular interface that connects the Fanconi anemia protein FANCM to the Bloom syndrome dissolvasome.

    PubMed

    Hoadley, Kelly A; Xue, Yutong; Ling, Chen; Takata, Minoru; Wang, Weidong; Keck, James L

    2012-03-20

    The RMI subcomplex (RMI1/RMI2) functions with the BLM helicase and topoisomerase IIIα in a complex called the "dissolvasome," which separates double-Holliday junction DNA structures that can arise during DNA repair. This activity suppresses potentially harmful sister chromatid exchange (SCE) events in wild-type cells but not in cells derived from Bloom syndrome patients with inactivating BLM mutations. The RMI subcomplex also associates with FANCM, a component of the Fanconi anemia (FA) core complex that is important for repair of stalled DNA replication forks. The RMI/FANCM interface appears to help coordinate dissolvasome and FA core complex activities, but its precise role remains poorly understood. Here, we define the structure of the RMI/FANCM interface and investigate its roles in coordinating cellular DNA-repair activities. The X-ray crystal structure of the RMI core complex bound to a well-conserved peptide from FANCM shows that FANCM binds to both RMI proteins through a hydrophobic "knobs-into-holes" packing arrangement. The RMI/FANCM interface is shown to be critical for interaction between the components of the dissolvasome and the FA core complex. FANCM variants that substitute alanine for key interface residues strongly destabilize the complex in solution and lead to increased SCE levels in cells that are similar to those observed in blm- or fancm-deficient cells. This study provides a molecular view of the RMI/FANCM complex and highlights a key interface utilized in coordinating the activities of two critical eukaryotic DNA-damage repair machines.

  9. Oral manifestations compatible with chronic graft-versus-host disease in patients with Fanconi anemia.

    PubMed

    Grein Cavalcanti, Laura; Fuentes Araújo, Renata L; Bonfim, Carmem; Torres-Pereira, Cassius C

    2015-02-01

    Fanconi anemia (FA) is a genetic disease that is characterized by several congenital abnormalities and progressive bone marrow failure and is associated with an increased susceptibility to malignant disorders. Currently, the only potential cure for hematological disorders is hematopoietic stem cell transplantation (HSCT). However, 1 of the most common complications after HSCT is the development of oral chronic graft-versus-host disease (cGVHD), which is also a risk factor for the development of cancer, particularly oral squamous cell carcinoma. Therefore, the purpose of this study was to describe the prevalence and characteristics of oral manifestations compatible with cGVHD in patients diagnosed with FA according to the National Institutes of Health (NIH) consensus criteria. A total of 96 patients (51 females, 45 males; median age, 16 years) with FA, who were in medical follow-up after HSCT at the outpatient clinic of the bone marrow transplantation unit (Hospital de Clínicas from the Universidade Federal do Paraná) underwent an oral evaluation between January 2013 and December 2013. Post-HSCT periods varied from 1 to 261 months and were divided into 3 periods: immediate post-HSCT period; intermediate post-HSC period, and late post-HSCT period. Among the evaluated patients, 40 of 96 (42%) presented with oral manifestations of cGVHD, with 29 of 40 (73%) of these patients in the late post-HSCT period. NIH scale scores varied from 0 to 10, and lichenoid and hyperkeratotic lesions were the abnormalities most frequently observed (100%). Overall, a high prevalence of oral manifestations was observed for cGVHD patients with FA. These data highlight the importance of monitoring oral manifestations compatible with cGVHD to identify and treat individuals with a higher risk of developing oral cancer. Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  10. Cancer stem cells are enriched in Fanconi anemia head and neck squamous cell carcinomas

    PubMed Central

    WU, JEAN; MU, QINGSHAN; THIVIYANATHAN, VARATHARASA; ANNAPRAGADA, ANANTH; VIGNESWARAN, NADARAJAH

    2014-01-01

    Fanconi anemia (FA) patients have an increased risk of head and neck squamous cell carcinoma (HNSCC) at a higher rate with no apparent risk factors. HNSCC of FA patients is an aggressive tumor characterized by multifocal origin, early metastases and frequent recurrences. Given that cancer stem cells (CSC) drive tumorigenesis, tumor recurrence and metastasis, in this study, we characterized the CSC population in FA and sporadic HNSCC. The Aldefluor assay was used to characterize and isolate CSC with high aldehyde dehydrogenase (ALDH) activity (ALDHpos) in cell lines derived from FA and sporadic HNSCC. Isolated ALDHpos and ALDHneg cells were examined for the expression of stemness genes using reverse transcription-polymerase chain reaction (RT-PCR) array. Tumor cell-derived FA and sporadic HNSCC were examined for their ability to form tumorspheres in vitro. Stem-like cell population in FA and sporadic HNSCC in human and mouse xenograft tumors were evaluated using ALDH isoform 1 (ALDH1) immunohistochemistry. FA-HNSCC cell lines harbor a greater proportion of ALDHpos cells (15–31%) compared to sporadic HNSCC (10%). Expression of Nanog, Oct-3/4 and Stella, molecular markers of undifferentiated embryonic stem (ES) cells were detected in the ALDHpos FA-HNSCC cells and not in the ALDHneg cells. FA-HNSCC cell lines revealed enhanced in vitro tumorsphere formation compared to sporadic HNSCC cells. A higher percentage of ALDH1pos tumor cells are noted in the human and mouse xenograft tumors of FA-HNSCC compared to sporadic HNSCC tumors. FA-HNSCC are highly enriched for CSC and may serve as a model to develop CSC-targeted therapies for HNSCC. PMID:25340704

  11. A case report and literature review of Fanconi Anemia (FA) diagnosed by genetic testing.

    PubMed

    Solomon, Ponnumony John; Margaret, Priya; Rajendran, Ramya; Ramalingam, Revathy; Menezes, Godfred A; Shirley, Alph S; Lee, Seung Jun; Seong, Moon-Woo; Park, Sung Sup; Seol, Dodam; Seo, Soo Hyun

    2015-05-08

    Fanconi anemia (FA) is a genetically heterogeneous rare autosomal recessive disorder characterized by congenital malformations, hematological problems and predisposition to malignancies. The genes that have been found to be mutated in FA patients are called FANC. To date 16 distinct FANC genes have been reported. Among these, mutations in FANCA are the most frequent among FA patients worldwide which account for 60- 65%. In this study, a nine years old male child was brought to our hospital one year ago for opinion and advice. He was the third child born to consanguineous parents. The mutation analyses were performed for proband, parents, elder sibling and the relatives [maternal aunt and maternal aunt's son (cousin)]. Molecular genetic testing [targeted next-generation sequencing (MiSeq, Illumina method)] was performed by mutation analysis in 15 genes involved. Entire coding exons and their flanking regions of the genes were analysed. Sanger sequencing [(ABI 3730 analyzer by Applied Biosystems)] was performed using primers specific for 43 coding exons of the FANCA gene. A novel splice site mutation, c.3066 + 1G > T, (IVS31 + 1G > T), homozygote was detected by sequencing in the patient. The above sequence variant was identified in heterozygous state in his parents. Further, the above sequence variant was not identified in other family members (elder sibling, maternal aunt and cousin). It is concluded that genetic study should be done if possible in all the cases of suspected FA, including siblings, parents and close blood relatives. It will help us to plan appropriate treatment and also to select suitable donor for hematopoietic stem cell transplantation and to plan for genetic counseling. In addition to the case report, the main focus of this manuscript was to review literature on role of FANCA gene in FA since large number of FANCA mutations and polymorphisms have been identified.

  12. Molecular Cytogenetic Approach to Characterize Novel and Cryptic Chromosome Abnormalities in Childhood Myeloid Malignances of Fanconi Anemia.

    PubMed

    Borges, Maria L R; Capela de Matos, Roberto R; Amaral, Bethânia D A Silva; Soares-Ventura, Eliane M; Leite, Edinalva P; Silva, Mariluze O D; Cornélio, Maria T M Nogueira; Silva, Maria L M; Liehr, Thomas; Marques-Salles, Terezinha D J

    2017-03-01

    Myeloid malignancies can be either primary or secondary, whether or not a specific cause can be determined. Fanconi anemia (FA), a rare constitutional bone marrow failure, usually presents an increased possibility of clonal evolution, due to the increase in chromosomal instability, TP53 activation, and cell death. The evolution of FA may include aplastic anemia by the progressive failure of the bone marrow and myelod neoplasias, such as acute myeloid leukemia and myelodysplastic syndrome. Chromosome abnormalities, particularly of chromosomes, 1, 3, and 7, during the aplastic phase of the disease are predictive of evolution to acute myeloid leukemia/myelodysplastic syndrome. Cytogenetic studies are indispensable to characterize chromosome abnormalities, and thus an important part of the clinical management, and for planning of therapeutic interventions. Here, clinical data and outcomes of 4 FA, 3 of them with myeloid malignances and 1 asymptomatic, and detailed characterization of their chromosome abnormalities using cytogenetics techniques are described.

  13. Disseminated Medulloblastoma in a Child with Germline BRCA2 6174delT Mutation and without Fanconi Anemia

    PubMed Central

    Xu, Jingying; Margol, Ashley Sloane; Shukla, Anju; Ren, Xiuhai; Finlay, Jonathan L.; Krieger, Mark D.; Gilles, Floyd H.; Couch, Fergus J.; Aziz, Meraj; Fung, Eric T.; Asgharzadeh, Shahab; Barrett, Michael T.; Erdreich-Epstein, Anat

    2015-01-01

    Medulloblastoma, the most common malignant brain tumor in children, occurs with increased frequency in individuals with Fanconi anemia who have biallelic germline mutations in BRCA2. We describe an 8-year-old child who had disseminated anaplastic medulloblastoma and a deleterious heterozygous BRCA2 6174delT germline mutation. Molecular profiling was consistent with Group 4 medulloblastoma. The posterior fossa mass was resected and the patient received intensive chemotherapy and craniospinal irradiation. Despite this, the patient succumbed to a second recurrence of his medulloblastoma, which presented 8 months after diagnosis as malignant pleural and peritoneal effusions. Continuous medulloblastoma cell lines were isolated from the original tumor (CHLA-01-MED) and the malignant pleural effusion (CHLA-01R-MED). Here, we provide their analyses, including in vitro and in vivo growth, drug sensitivity, comparative genomic hybridization, and next generation sequencing analysis. In addition to the BRCA2 6174delT, the medulloblastoma cells had amplification of MYC, deletion at Xp11.2, and isochromosome 17, but no structural variations or overexpression of GFI1 or GFI1B. To our knowledge, this is the first pair of diagnosis/recurrence medulloblastoma cell lines, the only medulloblastoma cell lines with BRCA2 6174delT described to date, and the first reported case of a child with medulloblastoma associated with a germline BRCA2 6174delT who did not also have Fanconi anemia. PMID:26380221

  14. Differential expression of TP53 associated genes in Fanconi anemia cells after mitomycin C and hydroxyurea treatment.

    PubMed

    Martinez, Angélica; Hinz, John M; Gómez, Laura; Molina, Bertha; Acuña, Hilda; Jones, Irene M; Frias, Sara; Coleman, Matthew A

    2008-10-30

    Fanconi anemia (FA) is a rare, heritable chromosomal instability disease characterized by several congenital defects and cancer predisposition. Functional interactions between specific FA proteins and DNA damage response and repair activities have been reported, but the interplay between these mechanisms for maintaining genomic stability are not well understood. Many DNA damage response proteins are transcriptionally regulated by the tumor suppressor protein p53 (TP53), suggesting an important regulatory role for the DNA damage and stress response pathway. To better understand the association between FA and the DNA damage stress response we analyzed the levels of chromosomal damage and damage mediated gene transcription responses in lymphoblastoid cells derived from normal individuals and patients carrying the most common FA complementation group (FA-A). Chromosomal aberrations were first measured after exposure to mitomicyn C (MMC) or hydroxyurea (HU). Aliquots of the same cell were than assayed for the transcriptional response of 21 DNA damage and stress response genes using quantitative real-time PCR. The FA-A lymphoblastoid cells showed significant increases in the frequency of chromosome aberrations relative to non-FA-A lymphoblastoid lines after MMC treatment. The MMC induced damage was correlated with a general increase in expression of TP53-modulated DNA damage stress response genes involved in processes such as DNA repair, cell cycle progression, and apoptosis. Following HU treatment FA cells showed a decreased induction of CAs with much less transcriptional differences between targeted genes. Overall, the differences between the normal and FA-A cells after genotoxic treatments imply an increased activation and reliance of FA cells on the down-stream activities of TP53 for prevention of cell killing and chromosome damage from interstrand crosslinks but not for general replication arrest and double strand breaks. Furthermore, these results imply a

  15. Fanconi anemia cells with unrepaired DNA damage activate components of the checkpoint recovery process.

    PubMed

    Rodríguez, Alfredo; Torres, Leda; Juárez, Ulises; Sosa, David; Azpeitia, Eugenio; García-de Teresa, Benilde; Cortés, Edith; Ortíz, Rocío; Salazar, Ana M; Ostrosky-Wegman, Patricia; Mendoza, Luis; Frías, Sara

    2015-09-18

    The FA/BRCA pathway repairs DNA interstrand crosslinks. Mutations in this pathway cause Fanconi anemia (FA), a chromosome instability syndrome with bone marrow failure and cancer predisposition. Upon DNA damage, normal and FA cells inhibit the cell cycle progression, until the G2/M checkpoint is turned off by the checkpoint recovery, which becomes activated when the DNA damage has been repaired. Interestingly, highly damaged FA cells seem to override the G2/M checkpoint. In this study we explored with a Boolean network model and key experiments whether checkpoint recovery activation occurs in FA cells with extensive unrepaired DNA damage. We performed synchronous/asynchronous simulations of the FA/BRCA pathway Boolean network model. FA-A and normal lymphoblastoid cell lines were used to study checkpoint and checkpoint recovery activation after DNA damage induction. The experimental approach included flow cytometry cell cycle analysis, cell division tracking, chromosome aberration analysis and gene expression analysis through qRT-PCR and western blot. Computational simulations suggested that in FA mutants checkpoint recovery activity inhibits the checkpoint components despite unrepaired DNA damage, a behavior that we did not observed in wild-type simulations. This result implies that FA cells would eventually reenter the cell cycle after a DNA damage induced G2/M checkpoint arrest, but before the damage has been fixed. We observed that FA-A cells activate the G2/M checkpoint and arrest in G2 phase, but eventually reach mitosis and divide with unrepaired DNA damage, thus resolving the initial checkpoint arrest. Based on our model result we look for ectopic activity of checkpoint recovery components. We found that checkpoint recovery components, such as PLK1, are expressed to a similar extent as normal undamaged cells do, even though FA-A cells harbor highly damaged DNA. Our results show that FA cells, despite extensive DNA damage, do not loss the capacity to express

  16. GS-Nitroxide (JP4-039)-Mediated Radioprotection of Human Fanconi Anemia Cell Lines

    PubMed Central

    Bernard, Mark E.; Kim, Hyun; Berhane, Hebist; Epperly, Michael W.; Franicola, Darcy; Zhang, Xichen; Houghton, Frank; Shields, Donna; Wang, Hong; Bakkenist, Christopher J.; Frantz, Marie-Celine; Forbeck, Erin M.; Goff, Julie P.; Wipf, Peter; Greenberger, Joel S.

    2011-01-01

    Fanconi anemia (FA) is an inherited disorder characterized by defective DNA repair and cellular sensitivity to DNA crosslinking agents. Clinically, FA is associated with high risk for marrow failure, leukemia and head and neck squamous cell carcinoma (HNSCC). Radiosensitivity in FA patients compromises the use of total-body irradiation for hematopoietic stem cell transplantation and radiation therapy for HNSCC. A radioprotector for the surrounding tissue would therefore be very valuable during radiotherapy for HNSCC. Clonogenic radiation survival curves were determined for pre- or postirradiation treatment with the parent nitroxide Tempol or JP4-039 in cells of four FA patient-derived cell lines and two transgene-corrected subclonal lines. FancG–/– (PD326) and FancD2–/– (PD20F) patient lines were more sensitive to the DNA crosslinking agent mitomycin C (MMC) than their transgene-restored subclonal cell lines (both P < 0.0001). FancD2–/– cells were more radiosensitive than the transgene restored subclonal cell line (ñ = 2.0 ± 0.7 and 4.7 ± 2.2, respectively, P = 0.03). In contrast, FancG–/– cells were radioresistant relative to the transgene-restored subclonal cell line (ñ = 9.4 ± 1.5 and 2.2 ± 05, respectively, P = 0.001). DNA strand breaks measured by the comet assay correlated with radiosensitivity. Cell lines from a Fanc-C and Fanc-A patients showed radiosensitivity similar to that of Fanc-D2–/– cells. A fluorophore-tagged JP4-039 (BODIPY-FL) analog targeted the mitochondria of the cell lines. Preirradiation or postirradiation treatment with JP4-039 at a lower concentration than Tempol significantly increased the radioresistance and stabilized the antioxidant stores of all cell lines. Tempol increased the toxicity of MMC in FancD2–/– cells. These data provide support for the potential clinical use of JP4-039 for normal tissue radioprotection during chemoradiotherapy in FA patients. PMID:21939290

  17. GS-nitroxide (JP4-039)-mediated radioprotection of human Fanconi anemia cell lines.

    PubMed

    Bernard, Mark E; Kim, Hyun; Berhane, Hebist; Epperly, Michael W; Franicola, Darcy; Zhang, Xichen; Houghton, Frank; Shields, Donna; Wang, Hong; Bakkenist, Christopher J; Frantz, Marie-Celine; Forbeck, Erin M; Goff, Julie P; Wipf, Peter; Greenberger, Joel S

    2011-11-01

    Fanconi anemia (FA) is an inherited disorder characterized by defective DNA repair and cellular sensitivity to DNA crosslinking agents. Clinically, FA is associated with high risk for marrow failure, leukemia and head and neck squamous cell carcinoma (HNSCC). Radiosensitivity in FA patients compromises the use of total-body irradiation for hematopoietic stem cell transplantation and radiation therapy for HNSCC. A radioprotector for the surrounding tissue would therefore be very valuable during radiotherapy for HNSCC. Clonogenic radiation survival curves were determined for pre- or postirradiation treatment with the parent nitroxide Tempol or JP4-039 in cells of four FA patient-derived cell lines and two transgene-corrected subclonal lines. FancG(-/-) (PD326) and FancD2(-/-) (PD20F) patient lines were more sensitive to the DNA crosslinking agent mitomycin C (MMC) than their transgene-restored subclonal cell lines (both P < 0.0001). FancD2(-/-) cells were more radiosensitive than the transgene restored subclonal cell line (ñ = 2.0 ± 0.7 and 4.7 ± 2.2, respectively, P = 0.03). In contrast, FancG(-/-) cells were radioresistant relative to the transgene-restored subclonal cell line (ñ = 9.4 ± 1.5 and 2.2 ± 05, respectively, P = 0.001). DNA strand breaks measured by the comet assay correlated with radiosensitivity. Cell lines from a Fanc-C and Fanc-A patients showed radiosensitivity similar to that of Fanc-D2(-/-) cells. A fluorophore-tagged JP4-039 (BODIPY-FL) analog targeted the mitochondria of the cell lines. Preirradiation or postirradiation treatment with JP4-039 at a lower concentration than Tempol significantly increased the radioresistance and stabilized the antioxidant stores of all cell lines. Tempol increased the toxicity of MMC in FancD2(-/-) cells. These data provide support for the potential clinical use of JP4-039 for normal tissue radioprotection during chemoradiotherapy in FA patients.

  18. Molecular analysis by electron microscopy of the removal of psoralen-photoinduced DNA cross-links in normal and Fanconi's anemia fibroblasts

    SciTech Connect

    Rousset, S.; Nocentini, S.; Revet, B.; Moustacchi, E. )

    1990-04-15

    The induction and fate of psoralen-photoinduced DNA interstrand cross-links in the genome of Fanconi's anemia (FA) fibroblasts of complementation groups A and B, and of normal human fibroblasts, were investigated by quantitative analysis of totally denatured DNA fragments visualized by electron microscopy. 8-Methoxypsoralen (5 x 10(-5) M) interstrand cross-links were induced as a function of the near ultraviolet light dose. With time of postexposure incubation, a fraction of interstrand cross-links disappeared in all cell lines. However, 24 h after treatment, this removal was significantly lower in the two FA group A cell lines examined (34-39%) than in the FA group B and normal cell lines (43-53 and 47-57%, respectively). These data indicate that FA cells are at least able to recognize and incise interstrand cross-links, as normal cells do, although group A cells seem somewhat hampered in this process. This is in accord with data obtained on the same cell lines using another biochemical assay. Since the fate of cross-links in FA constituted a controversial matter, it is important to stress that two different methodologies applied to genetically well defined cell lines led to the same conclusions.

  19. Alternaria alternata invasive fungal infection in a patient with Fanconi's anemia after an unrelated bone marrow transplant.

    PubMed

    Ferreira, Isabelina de Sousa; Teixeira, Gilda; Abecasis, Manuel

    2013-02-01

    Alternaria spp. have emerged as opportunistic pathogens particularly in immunosuppressed patients, such as bone marrow transplant recipients. The authors present a case of Alternaria alternata in a patient with Fanconi's anemia, who received antifungal prophylaxis with posaconazole after an unrelated bone marrow transplantation, followed by empirical antifungal treatment with caspofungin when persistent fever emerged until cutaneous lesions eventually appeared. At that time there were clinical reasons to assume that the patient had an infection with an emerging fungus. This consideration triggered a change of the antifungal therapy from caspofungin to liposomal amphotericin B. After collecting sufficient evidence for the presence of an invasive fungal infection by A. alternata and given the severity of neutropenia and other immunosuppression, oral posaconazole was added to liposomal amphotericin B. The course of disease in this case suggests a possibly synergistic interaction between liposomal amphotericin B and posaconazole when administered simultaneously to treat an invasive systemic infection by Alternaria spp. in immunocompromised patients.

  20. A Distinct Replication Fork Protection Pathway Connects Fanconi Anemia Tumor Suppressors to RAD51-BRCA1/2

    PubMed Central

    Schlacher, Katharina; Wu, Hong; Jasin, Maria

    2014-01-01

    SUMMARY Genes mutated in patients with Fanconi anemia (FA) interact with the DNA repair genes BRCA1 and BRCA2/FANCD1 to suppress tumorigenesis, but the molecular functions ascribed to them cannot fully explain all of their cellular roles. Here, we show a repair-independent requirement for FA genes, including FANCD2, and BRCA1 in protecting stalled replication forks from degradation. Fork protection is surprisingly rescued in FANCD2-deficient cells by elevated RAD51 levels or stabilized RAD51 filaments. Moreover, FANCD2-mediated fork protection is epistatic with RAD51 functions, revealing an unanticipated fork protection pathway that connects FA genes to RAD51 and the BRCA1/2 breast cancer suppressors. Collective results imply a unified molecular mechanism for repair-independent functions of FA, RAD51, and BRCA1/2 proteins in preventing genomic instability and suppressing tumorigenesis. PMID:22789542

  1. Involvement of Fanconi anemia genes FANCD2 and FANCF in the molecular basis of drug resistance in leukemia.

    PubMed

    Yao, Chenjiao; Du, Wei; Chen, Haibiug; Xiao, Sheng; Huang, Lihua; Chen, Fang-Ping

    2015-06-01

    The Fanconi anemia (FA)‑associated proteins FANCF and FANCD2 are important components of the FA pathway of DNA crosslink repair. FANCF and FANCD2 have been found to be involved in drug‑resistant multiple myeloma, ovarian cancer, non‑small‑cell lung cancer, and head and neck cancer. However, it is unclear whether these two genes participate in adriamycin (ADR)‑resistant leukemia. Therefore, the aim of the current study was to investigate FANCF and FANCD2 expression in drug‑resistant and drug‑sensitive leukemia cells. Western blot analysis revealed enhanced FANCF expression and monoubiquitination of FANCD2 in ADR‑resistant cells. Additionally, it was observed that drug‑resistant cells had reduced DNA damage compared with drug‑sensitive cells. The results of this study indicate that the FA pathway may confer leukemia resistance to ADR via enhanced DNA interstrand crosslink repair.

  2. UHRF1 is a sensor for DNA interstrand crosslinks and recruits FANCD2 to initiate the Fanconi anemia pathway.

    PubMed

    Liang, Chih-Chao; Zhan, Bao; Yoshikawa, Yasunaga; Haas, Wilhelm; Gygi, Steven P; Cohn, Martin A

    2015-03-31

    The Fanconi anemia (FA) pathway is critical for the cellular response to toxic DNA interstrand crosslinks (ICLs). Using a biochemical purification strategy, we identified UHRF1 as a protein that specifically interacts with ICLs in vitro and in vivo. Reduction of cellular levels of UHRF1 by RNAi attenuates the FA pathway and sensitizes cells to mitomycin C. Knockdown cells display a drastic reduction in FANCD2 foci formation. Using live-cell imaging, we observe that UHRF1 is rapidly recruited to chromatin in response to DNA crosslinking agents and that this recruitment both precedes and is required for the recruitment of FANCD2 to ICLs. Based on these results, we describe a mechanism of ICL sensing and propose that UHRF1 is a critical factor that binds to ICLs. In turn, this binding is necessary for the subsequent recruitment of FANCD2, which allows the DNA repair process to initiate.

  3. A distinct replication fork protection pathway connects Fanconi anemia tumor suppressors to RAD51-BRCA1/2.

    PubMed

    Schlacher, Katharina; Wu, Hong; Jasin, Maria

    2012-07-10

    Genes mutated in patients with Fanconi anemia (FA) interact with the DNA repair genes BRCA1 and BRCA2/FANCD1 to suppress tumorigenesis, but the molecular functions ascribed to them cannot fully explain all of their cellular roles. Here, we show a repair-independent requirement for FA genes, including FANCD2, and BRCA1 in protecting stalled replication forks from degradation. Fork protection is surprisingly rescued in FANCD2-deficient cells by elevated RAD51 levels or stabilized RAD51 filaments. Moreover, FANCD2-mediated fork protection is epistatic with RAD51 functions, revealing an unanticipated fork protection pathway that connects FA genes to RAD51 and the BRCA1/2 breast cancer suppressors. Collective results imply a unified molecular mechanism for repair-independent functions of FA, RAD51, and BRCA1/2 proteins in preventing genomic instability and suppressing tumorigenesis.

  4. Role of Fanconi Anemia FANCG in Preventing Double-Strand Breakage and Chromosomal Rearrangement during DNA Replication

    SciTech Connect

    Tebbs, R S; Hinz, J M; Yamada, N A; Wilson, J B; Jones, N J; Salazar, E P; Thomas, C B; Jones, I M; Thompson, L H

    2003-10-04

    The Fanconi anemia (FA) proteins overlap with those of homologous recombination through FANCD1/BRCA2, but the biochemical functions of other FA proteins are unknown. By constructing and characterizing a null fancg mutant of hamster CHO cells, we present several new insights for FA. The fancg cells show a broad sensitivity to genotoxic agents, not supporting the conventional concept of sensitivity to only DNA crosslinking agents. The aprt mutation rate is normal, but hprt mutations are reduced, which we ascribe to the lethality of large deletions. CAD and dhfr gene amplification rates are increased, implying excess chromosomal breakage during DNA replication, and suggesting amplification as a contributing factor to cancer-proneness in FA patients. In S-phase cells, both spontaneous and mutagen-induced Rad51 nuclear foci are elevated. These results support a model in which FancG protein helps to prevent collapse of replication forks by allowing translesion synthesis or lesion bypass through homologous recombination.

  5. In-vivo assessment of DNA ligation efficiency and fidelity in cells from patients with Fanconi's anemia and other cancer-prone hereditary disorders.

    PubMed

    Rünger, T M; Sobotta, P; Dekant, B; Möller, K; Bauer, C; Kraemer, K H

    1993-04-01

    We developed a host cell DNA ligation assay, in which we transfected linearized plasmid pZ189 into human lymphoblasts or fibroblasts in order to assess the efficiency and accuracy of DNA ligation within these host cells. We used cell lines from patients with Fanconi's anemia and other chromosome breakage or instability syndromes (Bloom's syndrome, ataxia telangiectasia, Werner's syndrome). With the Fanconi's anemia lymphoblast line GM8010 we did not find a reduced, but a slightly hypermutable DNA ligation. Mutation analysis revealed a unique 7.9-12.5-fold increase in insertions or complex mutations. With cells from the other chromosome breakage/instability syndromes we also found a hypermutable and/or reduced DNA ligation. An impaired DNA ligation might be a common molecular mechanism of genetic instability in these disorders.

  6. Cells Deficient in the Fanconi Anemia Protein FANCD2 are Hypersensitive to the Cytotoxicity and DNA Damage Induced by Coffee and Caffeic Acid.

    PubMed

    Burgos-Morón, Estefanía; Calderón-Montaño, José Manuel; Orta, Manuel Luis; Guillén-Mancina, Emilio; Mateos, Santiago; López-Lázaro, Miguel

    2016-07-08

    Epidemiological studies have found a positive association between coffee consumption and a lower risk of cardiovascular disorders, some cancers, diabetes, Parkinson and Alzheimer disease. Coffee consumption, however, has also been linked to an increased risk of developing some types of cancer, including bladder cancer in adults and leukemia in children of mothers who drink coffee during pregnancy. Since cancer is driven by the accumulation of DNA alterations, the ability of the coffee constituent caffeic acid to induce DNA damage in cells may play a role in the carcinogenic potential of this beverage. This carcinogenic potential may be exacerbated in cells with DNA repair defects. People with the genetic disease Fanconi Anemia have DNA repair deficiencies and are predisposed to several cancers, particularly acute myeloid leukemia. Defects in the DNA repair protein Fanconi Anemia D2 (FANCD2) also play an important role in the development of a variety of cancers (e.g., bladder cancer) in people without this genetic disease. This communication shows that cells deficient in FANCD2 are hypersensitive to the cytotoxicity (clonogenic assay) and DNA damage (γ-H2AX and 53BP1 focus assay) induced by caffeic acid and by a commercial lyophilized coffee extract. These data suggest that people with Fanconi Anemia, or healthy people who develop sporadic mutations in FANCD2, may be hypersensitive to the carcinogenic activity of coffee.

  7. Cells Deficient in the Fanconi Anemia Protein FANCD2 are Hypersensitive to the Cytotoxicity and DNA Damage Induced by Coffee and Caffeic Acid

    PubMed Central

    Burgos-Morón, Estefanía; Calderón-Montaño, José Manuel; Orta, Manuel Luis; Guillén-Mancina, Emilio; Mateos, Santiago; López-Lázaro, Miguel

    2016-01-01

    Epidemiological studies have found a positive association between coffee consumption and a lower risk of cardiovascular disorders, some cancers, diabetes, Parkinson and Alzheimer disease. Coffee consumption, however, has also been linked to an increased risk of developing some types of cancer, including bladder cancer in adults and leukemia in children of mothers who drink coffee during pregnancy. Since cancer is driven by the accumulation of DNA alterations, the ability of the coffee constituent caffeic acid to induce DNA damage in cells may play a role in the carcinogenic potential of this beverage. This carcinogenic potential may be exacerbated in cells with DNA repair defects. People with the genetic disease Fanconi Anemia have DNA repair deficiencies and are predisposed to several cancers, particularly acute myeloid leukemia. Defects in the DNA repair protein Fanconi Anemia D2 (FANCD2) also play an important role in the development of a variety of cancers (e.g., bladder cancer) in people without this genetic disease. This communication shows that cells deficient in FANCD2 are hypersensitive to the cytotoxicity (clonogenic assay) and DNA damage (γ-H2AX and 53BP1 focus assay) induced by caffeic acid and by a commercial lyophilized coffee extract. These data suggest that people with Fanconi Anemia, or healthy people who develop sporadic mutations in FANCD2, may be hypersensitive to the carcinogenic activity of coffee. PMID:27399778

  8. Radiologic differences between bone marrow stromal and hematopoietic progenitor cell lines from Fanconi Anemia (Fancd2(-/-)) mice.

    PubMed

    Berhane, Hebist; Epperly, Michael W; Goff, Julie; Kalash, Ronny; Cao, Shaonan; Franicola, Darcy; Zhang, Xichen; Shields, Donna; Houghton, Frank; Wang, Hong; Wipf, Peter; Parmar, Kalindi; Greenberger, Joel S

    2014-01-01

    FancD2 plays a central role in the human Fanconi anemia DNA damage response (DDR) pathway. Fancd2(-/-) mice exhibit many features of human Fanconi anemia including cellular DNA repair defects. Whether the DNA repair defect in Fancd2(-/-) mice results in radiologic changes in all cell lineages is unknown. We measured stress of hematopoiesis in long-term marrow cultures and radiosensitivity in clonogenic survival curves, as well as comet tail intensity, total antioxidant stores and radiation-induced gene expression in hematopoietic progenitor compared to bone marrow stromal cell lines. We further evaluated radioprotection by a mitochondrial-targeted antioxidant GS-nitroxide, JP4-039. Hematopoiesis longevity in Fancd2(-/-) mouse long-term marrow cultures was diminished and bone marrow stromal cell lines were radiosensitive compared to Fancd2(+/+) stromal cells (Fancd2(-/-) D0 = 1.4 ± 0.1 Gy, ñ = 5.0 ± 0.6 vs. Fancd2(+/+) D0 = 1.6 ± 0.1 Gy, ñ = 6.7 ± 1.6), P = 0.0124 for D0 and P = 0.0023 for ñ, respectively). In contrast, Fancd2(-/-) IL-3-dependent hematopoietic progenitor cells were radioresistant (D0 = 1.71 ± 0.04 Gy and ñ = 5.07 ± 0.52) compared to Fancd2(+/+) (D0 = 1.39 ± 0.09 Gy and ñ = 2.31 ± 0.85, P = 0.001 for D0). CFU-GM from freshly explanted Fancd2(-/-) marrow was also radioresistant. Consistent with radiosensitivity, irradiated Fancd2(-/-) stromal cells had higher DNA damage by comet tail intensity assay compared to Fancd2(+/+) cells (P < 0.0001), slower DNA damage recovery, lower baseline total antioxidant capacity, enhanced radiation-induced depletion of antioxidants, and increased CDKN1A-p21 gene transcripts and protein. Consistent with radioresistance, Fancd2(-/-) IL-3-dependent hematopoietic cells had higher baseline and post irradiation total antioxidant capacity. While, there was no detectable alteration of radiation-induced cell cycle arrest with Fancd2(-/-) stromal cells, hematopoietic progenitor cells showed reduced G2/M cell cycle

  9. Radiologic Differences between Bone Marrow Stromal and Hematopoietic Progenitor Cell Lines from Fanconi Anemia (Fancd2−/−) Mice

    PubMed Central

    Berhane, Hebist; Epperly, Michael W.; Goff, Julie; Kalash, Ronny; Cao, Shaonan; Franicola, Darcy; Zhang, Xichen; Shields, Donna; Houghton, Frank; Wang, Hong; Wipf, Peter; Parmar, Kalindi; Greenberger, Joel S.

    2014-01-01

    FancD2 plays a central role in the human Fanconi anemia DNA damage response (DDR) pathway. Fancd2−/− mice exhibit many features of human Fanconi anemia including cellular DNA repair defects. Whether the DNA repair defect in Fancd2−/− mice results in radiologic changes in all cell lineages is unknown. We measured stress of hematopoiesis in long-term marrow cultures and radiosensitivity in clonogenic survival curves, as well as comet tail intensity, total antioxidant stores and radiation-induced gene expression in hematopoietic progenitor compared to bone marrow stromal cell lines. We further evaluated radioprotection by a mitochondrial-targeted antioxidant GS-nitroxide, JP4-039. Hematopoiesis longevity in Fancd2−/− mouse long-term marrow cultures was diminished and bone marrow stromal cell lines were radiosensitive compared to Fancd2+/+ stromal cells (Fancd2−/− D0 = 1.4 ± 0.1 Gy, ñ = 5.0 ± 0.6 vs. Fancd2+/+ D0 = 1.6 ± 0.1 Gy, ñ = 6.7 ± 1.6), P = 0.0124 for D0 and P = 0.0023 for ñ, respectively). In contrast, Fancd2−/− IL-3-dependent hematopoietic progenitor cells were radioresistant (D0 = 1.71 ± 0.04 Gy and ñ = 5.07 ± 0.52) compared to Fancd2+/+ (D0 = 1.39 ± 0.09 Gy and ñ = 2.31 ± 0.85, P = 0.001 for D0). CFU-GM from freshly explanted Fancd2−/− marrow was also radioresistant. Consistent with radiosensitivity, irradiated Fancd2−/− stromal cells had higher DNA damage by comet tail intensity assay compared to Fancd2+/+ cells (P < 0.0001), slower DNA damage recovery, lower baseline total antioxidant capacity, enhanced radiation-induced depletion of antioxidants, and increased CDKN1A-p21 gene transcripts and protein. Consistent with radioresistance, Fancd2−/− IL-3-dependent hematopoietic cells had higher baseline and post irradiation total antioxidant capacity. While, there was no detectable alteration of radiation-induced cell cycle arrest with Fancd2−/− stromal cells, hematopoietic progenitor cells showed reduced G2/M

  10. Forkhead transcription factor FoxF1 interacts with Fanconi anemia protein complexes to promote DNA damage response

    PubMed Central

    Pradhan, Arun; Ustiyan, Vladimir; Zhang, Yufang; Kalin, Tanya V.; Kalinichenko, Vladimir V.

    2016-01-01

    Forkhead box F1 (Foxf1) transcription factor is an important regulator of embryonic development but its role in tumor cells remains incompletely understood. While 16 proteins were characterized in Fanconi anemia (FA) core complex, its interactions with cellular transcriptional machinery remain poorly characterized. Here, we identified FoxF1 protein as a novel interacting partner of the FA complex proteins. Using multiple human and mouse tumor cell lines and Foxf1+/− mice we demonstrated that FoxF1 physically binds to and increases stability of FA proteins. FoxF1 co-localizes with FANCD2 in DNA repair foci in cultured cells and tumor tissues obtained from cisplatin-treated mice. In response to DNA damage, FoxF1-deficient tumor cells showed significantly reduced FANCD2 monoubiquitination and FANCM phosphorylation, resulting in impaired formation of DNA repair foci. FoxF1 knockdown caused chromosomal instability, nuclear abnormalities, and increased tumor cell death in response to DNA-damaging agents. Overexpression of FoxF1 in DNA-damaged cells improved stability of FA proteins, decreased chromosomal and nuclear aberrations, restored formation of DNA repair foci and prevented cell death after DNA damage. These findings demonstrate that FoxF1 is a key component of FA complexes and a critical mediator of DNA damage response in tumor cells. PMID:26625197

  11. Forkhead transcription factor FoxF1 interacts with Fanconi anemia protein complexes to promote DNA damage response.

    PubMed

    Pradhan, Arun; Ustiyan, Vladimir; Zhang, Yufang; Kalin, Tanya V; Kalinichenko, Vladimir V

    2016-01-12

    Forkhead box F1 (Foxf1) transcription factor is an important regulator of embryonic development but its role in tumor cells remains incompletely understood. While 16 proteins were characterized in Fanconi anemia (FA) core complex, its interactions with cellular transcriptional machinery remain poorly characterized. Here, we identified FoxF1 protein as a novel interacting partner of the FA complex proteins. Using multiple human and mouse tumor cell lines and Foxf1+/- mice we demonstrated that FoxF1 physically binds to and increases stability of FA proteins. FoxF1 co-localizes with FANCD2 in DNA repair foci in cultured cells and tumor tissues obtained from cisplatin-treated mice. In response to DNA damage, FoxF1-deficient tumor cells showed significantly reduced FANCD2 monoubiquitination and FANCM phosphorylation, resulting in impaired formation of DNA repair foci. FoxF1 knockdown caused chromosomal instability, nuclear abnormalities, and increased tumor cell death in response to DNA-damaging agents. Overexpression of FoxF1 in DNA-damaged cells improved stability of FA proteins, decreased chromosomal and nuclear aberrations, restored formation of DNA repair foci and prevented cell death after DNA damage. These findings demonstrate that FoxF1 is a key component of FA complexes and a critical mediator of DNA damage response in tumor cells.

  12. Regulation of the Fanconi anemia pathway by a CUE ubiquitin-binding domain in the FANCD2 protein.

    PubMed

    Rego, Meghan A; Kolling, Frederick W; Vuono, Elizabeth A; Mauro, Maurizio; Howlett, Niall G

    2012-09-06

    The Fanconi anemia (FA)-BRCA pathway is critical for the repair of DNA interstrand crosslinks (ICLs) and the maintenance of chromosome stability. A key step in FA-BRCA pathway activation is the covalent attachment of monoubiquitin to FANCD2 and FANCI. Monoubiquitinated FANCD2 and FANCI localize in chromatin-associated nuclear foci where they interact with several well-characterized DNA repair proteins. Importantly, very little is known about the structure, function, and regulation of FANCD2. Herein, we describe the identification and characterization of a CUE (coupling of ubiquitin conjugation to endoplasmic reticulum degradation) ubiquitin-binding domain (UBD) in FANCD2, and demonstrate that the CUE domain mediates noncovalent binding to ubiquitin in vitro. We show that although mutation of the CUE domain destabilizes FANCD2, the protein remains competent for DNA damage-inducible monoubiquitination and phosphorylation. Importantly, we demonstrate that the CUE domain is required for interaction with FANCI, retention of monoubiquitinated FANCD2, and FANCI in chromatin, and for efficient ICL repair. Our results suggest a model by which heterodimerization of monoubiquitinated FANCD2 and FANCI in chromatin is mediated in part through a noncovalent interaction between the FANCD2 CUE domain and monoubiquitin covalently attached to FANCI, and that this interaction shields monoubiquitinated FANCD2 from polyubiquitination and proteasomal degradation.

  13. A ubiquitin-binding protein, FAAP20, links RNF8-mediated ubiquitination to the Fanconi anemia DNA repair network.

    PubMed

    Yan, Zhijiang; Guo, Rong; Paramasivam, Manikandan; Shen, Weiping; Ling, Chen; Fox, David; Wang, Yucai; Oostra, Anneke B; Kuehl, Julia; Lee, Duck-Yeon; Takata, Minoru; Hoatlin, Maureen E; Schindler, Detlev; Joenje, Hans; de Winter, Johan P; Li, Lei; Seidman, Michael M; Wang, Weidong

    2012-07-13

    The Fanconi anemia (FA) protein network is necessary for repair of DNA interstrand crosslinks (ICLs), but its control mechanism remains unclear. Here we show that the network is regulated by a ubiquitin signaling cascade initiated by RNF8 and its partner, UBC13, and mediated by FAAP20, a component of the FA core complex. FAAP20 preferentially binds the ubiquitin product of RNF8-UBC13, and this ubiquitin-binding activity and RNF8-UBC13 are both required for recruitment of FAAP20 to ICLs. Both RNF8 and FAAP20 are required for recruitment of FA core complex and FANCD2 to ICLs, whereas RNF168 can modulate efficiency of the recruitment. RNF8 and FAAP20 are needed for efficient FANCD2 monoubiquitination, a key step of the FA network; RNF8 and the FA core complex work in the same pathway to promote cellular resistance to ICLs. Thus, the RNF8-FAAP20 ubiquitin cascade is critical for recruiting FA core complex to ICLs and for normal function of the FA network.

  14. Crosstalk between BRCA-Fanconi anemia and mismatch repair pathways prevents MSH2-dependent aberrant DNA damage responses.

    PubMed

    Peng, Min; Xie, Jenny; Ucher, Anna; Stavnezer, Janet; Cantor, Sharon B

    2014-08-01

    Several proteins in the BRCA-Fanconi anemia (FA) pathway, such as FANCJ, BRCA1, and FANCD2, interact with mismatch repair (MMR) pathway factors, but the significance of this link remains unknown. Unlike the BRCA-FA pathway, the MMR pathway is not essential for cells to survive toxic DNA interstrand crosslinks (ICLs), although MMR proteins bind ICLs and other DNA structures that form at stalled replication forks. We hypothesized that MMR proteins corrupt ICL repair in cells that lack crosstalk between BRCA-FA and MMR pathways. Here, we show that ICL sensitivity of cells lacking the interaction between FANCJ and the MMR protein MLH1 is suppressed by depletion of the upstream mismatch recognition factor MSH2. MSH2 depletion suppresses an aberrant DNA damage response, restores cell cycle progression, and promotes ICL resistance through a Rad18-dependent mechanism. MSH2 depletion also suppresses ICL sensitivity in cells deficient for BRCA1 or FANCD2, but not FANCA. Rescue by Msh2 loss was confirmed in Fancd2-null primary mouse cells. Thus, we propose that regulation of MSH2-dependent DNA damage response underlies the importance of interactions between BRCA-FA and MMR pathways.

  15. Histone H2AX and Fanconi anemia FANCD2 function in the same pathway to maintain chromosome stability.

    PubMed

    Bogliolo, Massimo; Lyakhovich, Alex; Callén, Elsa; Castellà, Maria; Cappelli, Enrico; Ramírez, María J; Creus, Amadeu; Marcos, Ricard; Kalb, Reinhard; Neveling, Kornelia; Schindler, Detlev; Surrallés, Jordi

    2007-03-07

    Fanconi anemia (FA) is a chromosome fragility syndrome characterized by bone marrow failure and cancer susceptibility. The central FA protein FANCD2 is known to relocate to chromatin upon DNA damage in a poorly understood process. Here, we have induced subnuclear accumulation of DNA damage to prove that histone H2AX is a novel component of the FA/BRCA pathway in response to stalled replication forks. Analyses of cells from H2AX knockout mice or expressing a nonphosphorylable H2AX (H2AX(S136A/S139A)) indicate that phosphorylated H2AX (gammaH2AX) is required for recruiting FANCD2 to chromatin at stalled replication forks. FANCD2 binding to gammaH2AX is BRCA1-dependent and cells deficient or depleted of H2AX show an FA-like phenotype, including an excess of chromatid-type chromosomal aberrations and hypersensitivity to MMC. This MMC hypersensitivity of H2AX-deficient cells is not further increased by depleting FANCD2, indicating that H2AX and FANCD2 function in the same pathway in response to DNA damage-induced replication blockage. Consequently, histone H2AX is functionally connected to the FA/BRCA pathway to resolve stalled replication forks and prevent chromosome instability.

  16. A simplified approach to improve the efficiency and safety of ex vivo hematopoietic gene therapy in fanconi anemia patients.

    PubMed

    Jacome, A; Navarro, S; Casado, J A; Rio, P; Madero, L; Estella, J; Sevilla, J; Badell, I; Ortega, J J; Olivé, T; Hanenberg, H; Segovia, J C; Bueren, J A

    2006-02-01

    Fanconi anemia (FA) is an inherited DNA repair disorder characterized by genetic instability of cells lacking a functional FA/BRCA pathway. Previous studies have shown that in vitro stimulation of bone marrow cells (BMCs) from FA mice promotes apoptosis, reduces the reconstitution ability of the stem cells, and induces myelodysplasia and myeloid leukemia upon reinfusion of the cells. This suggests the convenience of adapting standard protocols of gene therapy to FA. Here we show that the reserve of BM progenitors in FA patients is generally below 20% of normal values. Because this reduced reserve could activate the cycling of BM progenitors, we developed a simplified protocol to transduce BMCs from FA patients with gammaretroviral vectors. We demonstrate that a short in vitro manipulation (12-24 hr) of fresh mononuclear BMCs is sufficient to transduce 42% of hematopoietic progenitors from FA-A patients, in the absence of in vitro prestimulation. When FANCA-expressing vectors were used, this simple procedure reversed the phenotype of the BM progenitors from these patients. We propose that our approach will be more efficient and safer compared with standard gene therapy protocols for FA.

  17. Elucidation of the Fanconi Anemia Protein Network in Meiosis and Its Function in the Regulation of Histone Modifications.

    PubMed

    Alavattam, Kris G; Kato, Yasuko; Sin, Ho-Su; Maezawa, So; Kowalski, Ian J; Zhang, Fan; Pang, Qishen; Andreassen, Paul R; Namekawa, Satoshi H

    2016-10-18

    Precise epigenetic regulation of the sex chromosomes is vital for the male germline. Here, we analyze meiosis in eight mouse models deficient for various DNA damage response (DDR) factors, including Fanconi anemia (FA) proteins. We reveal a network of FA and DDR proteins in which FA core factors FANCA, FANCB, and FANCC are essential for FANCD2 foci formation, whereas BRCA1 (FANCS), MDC1, and RNF8 are required for BRCA2 (FANCD1) and SLX4 (FANCP) accumulation on the sex chromosomes during meiosis. In addition, FA proteins modulate distinct histone marks on the sex chromosomes: FA core proteins and FANCD2 regulate H3K9 methylation, while FANCD2 and RNF8 function together to regulate H3K4 methylation independently of FA core proteins. Our data suggest that RNF8 integrates the FA-BRCA pathway. Taken together, our study reveals distinct functions for FA proteins and illuminates the male sex chromosomes as a model to dissect the function of the FA-BRCA pathway.

  18. Crosstalk between BRCA-Fanconi anemia and mismatch repair pathways prevents MSH2-dependent aberrant DNA damage responses

    PubMed Central

    Peng, Min; Xie, Jenny; Ucher, Anna; Stavnezer, Janet; Cantor, Sharon B

    2014-01-01

    Several proteins in the BRCA-Fanconi anemia (FA) pathway, such as FANCJ, BRCA1, and FANCD2, interact with mismatch repair (MMR) pathway factors, but the significance of this link remains unknown. Unlike the BRCA-FA pathway, the MMR pathway is not essential for cells to survive toxic DNA interstrand crosslinks (ICLs), although MMR proteins bind ICLs and other DNA structures that form at stalled replication forks. We hypothesized that MMR proteins corrupt ICL repair in cells that lack crosstalk between BRCA-FA and MMR pathways. Here, we show that ICL sensitivity of cells lacking the interaction between FANCJ and the MMR protein MLH1 is suppressed by depletion of the upstream mismatch recognition factor MSH2. MSH2 depletion suppresses an aberrant DNA damage response, restores cell cycle progression, and promotes ICL resistance through a Rad18-dependent mechanism. MSH2 depletion also suppresses ICL sensitivity in cells deficient for BRCA1 or FANCD2, but not FANCA. Rescue by Msh2 loss was confirmed in Fancd2-null primary mouse cells. Thus, we propose that regulation of MSH2-dependent DNA damage response underlies the importance of interactions between BRCA-FA and MMR pathways. PMID:24966277

  19. Rad18 confers hematopoietic progenitor cell DNA damage tolerance independently of the Fanconi Anemia pathway in vivo.

    PubMed

    Yang, Yang; Poe, Jonathan C; Yang, Lisong; Fedoriw, Andrew; Desai, Siddhi; Magnuson, Terry; Li, Zhiguo; Fedoriw, Yuri; Araki, Kimi; Gao, Yanzhe; Tateishi, Satoshi; Sarantopoulos, Stefanie; Vaziri, Cyrus

    2016-05-19

    In cultured cancer cells the E3 ubiquitin ligase Rad18 activates Trans-Lesion Synthesis (TLS) and the Fanconi Anemia (FA) pathway. However, physiological roles of Rad18 in DNA damage tolerance and carcinogenesis are unknown and were investigated here. Primary hematopoietic stem and progenitor cells (HSPC) co-expressed RAD18 and FANCD2 proteins, potentially consistent with a role for Rad18 in FA pathway function during hematopoiesis. However, hematopoietic defects typically associated with fanc-deficiency (decreased HSPC numbers, reduced engraftment potential of HSPC, and Mitomycin C (MMC) -sensitive hematopoiesis), were absent in Rad18(-/-) mice. Moreover, primary Rad18(-/-) mouse embryonic fibroblasts (MEF) retained robust Fancd2 mono-ubiquitination following MMC treatment. Therefore, Rad18 is dispensable for FA pathway activation in untransformed cells and the Rad18 and FA pathways are separable in hematopoietic cells. In contrast with responses to crosslinking agents, Rad18(-/-) HSPC were sensitive to in vivo treatment with the myelosuppressive agent 7,12 Dimethylbenz[a]anthracene (DMBA). Rad18-deficient fibroblasts aberrantly accumulated DNA damage markers after DMBA treatment. Moreover, in vivo DMBA treatment led to increased incidence of B cell malignancy in Rad18(-/-) mice. These results identify novel hematopoietic functions for Rad18 and provide the first demonstration that Rad18 confers DNA damage tolerance and tumor-suppression in a physiological setting. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  20. Regulation of the Fanconi anemia pathway by a CUE ubiquitin-binding domain in the FANCD2 protein

    PubMed Central

    Rego, Meghan A.; Kolling, Frederick W.; Vuono, Elizabeth A.; Mauro, Maurizio

    2012-01-01

    The Fanconi anemia (FA)–BRCA pathway is critical for the repair of DNA interstrand crosslinks (ICLs) and the maintenance of chromosome stability. A key step in FA-BRCA pathway activation is the covalent attachment of monoubiquitin to FANCD2 and FANCI. Monoubiquitinated FANCD2 and FANCI localize in chromatin-associated nuclear foci where they interact with several well-characterized DNA repair proteins. Importantly, very little is known about the structure, function, and regulation of FANCD2. Herein, we describe the identification and characterization of a CUE (coupling of ubiquitin conjugation to endoplasmic reticulum degradation) ubiquitin-binding domain (UBD) in FANCD2, and demonstrate that the CUE domain mediates noncovalent binding to ubiquitin in vitro. We show that although mutation of the CUE domain destabilizes FANCD2, the protein remains competent for DNA damage-inducible monoubiquitination and phosphorylation. Importantly, we demonstrate that the CUE domain is required for interaction with FANCI, retention of monoubiquitinated FANCD2, and FANCI in chromatin, and for efficient ICL repair. Our results suggest a model by which heterodimerization of monoubiquitinated FANCD2 and FANCI in chromatin is mediated in part through a noncovalent interaction between the FANCD2 CUE domain and monoubiquitin covalently attached to FANCI, and that this interaction shields monoubiquitinated FANCD2 from polyubiquitination and proteasomal degradation. PMID:22855611

  1. Aurora A kinase is required for activation of the Fanconi anemia/BRCA pathway upon DNA damage.

    PubMed

    Chun, Min Jeong; Hwang, Soo Kyung; Kim, Hyoun Geun; Goh, Sung-Ho; Kim, Sunshin; Lee, Chang-Hun

    2016-07-01

    Previous studies have linked the DNA damage response to mitotic progression machinery. Mitotic kinases, such as Aurora A kinase and Polo-like kinase, are involved in the phosphorylation of cell cycle regulators in response to DNA damage. Here, we investigated the potential involvement of Aurora A kinase in the activation of the Fanconi anemia (FA)/BRCA pathway, which participates in cellular response to DNA interstrand cross-link lesions (ICL). Initially, we detected interactions between Aurora A kinase and FANCA protein, one of the components of the FA nuclear core complex. Silencing of Aurora A kinase led to inhibition of monoubiquitination of FANCD2 and formation of nuclear foci, the final consequences of FA/BRCA pathway activation upon ICL induction. An in vitro kinase assay revealed that Aurora A kinase phosphorylates S165 of FANCA. Moreover, this phosphorylation event was induced by the treatment with mitomycin C (MMC), an ICL-inducing agent. In cells overexpressing S165A mutant FANCA, monoubiquitination of FANCD2 and nuclear foci formation was impaired and cellular sensitivity to MMC was enhanced. These results suggest that S165 phosphorylation by Aurora A kinase is required for proper activation of the FA/BRCA pathway in response to DNA damage.

  2. Fanconi Anemia Mesenchymal Stromal Cells-Derived Glycerophospholipids Skew Hematopoietic Stem Cell Differentiation Through Toll-Like Receptor Signaling.

    PubMed

    Amarachintha, Surya; Sertorio, Mathieu; Wilson, Andrew; Li, Xiaoli; Pang, Qishen

    2015-11-01

    Fanconi anemia (FA) patients develop bone marrow (BM) failure or leukemia. One standard care for these devastating complications is hematopoietic stem cell transplantation. We identified a group of mesenchymal stromal cells (MSCs)-derived metabolites, glycerophospholipids, and their endogenous inhibitor, 5-(tetradecyloxy)-2-furoic acid (TOFA), as regulators of donor hematopoietic stem and progenitor cells. We provided two pieces of evidence that TOFA could improve hematopoiesis-supporting function of FA MSCs: (a) limiting-dilution cobblestone area-forming cell assay revealed that TOFA significantly increased cobblestone colonies in Fanca-/- or Fancd2-/- cocultures compared to untreated cocultures. (b) Competitive repopulating assay using output cells collected from cocultures showed that TOFA greatly alleviated the abnormal expansion of the donor myeloid (CD45.2+Gr1+Mac1+) compartment in both peripheral blood and BM of recipient mice transplanted with cells from Fanca-/- or Fancd2-/- cocultures. Furthermore, mechanistic studies identified Tlr4 signaling as the responsible pathway mediating the effect of glycerophospholipids. Thus, targeting glycerophospholipid biosynthesis in FA MSCs could be a therapeutic strategy to improve hematopoiesis and stem cell transplantation. © 2015 AlphaMed Press.

  3. Prevalence and clinical significance of visible oral lesions in patients with Fanconi Anemia at risk for head and neck cancer.

    PubMed

    Velleuer, Eunike; Dietrich, Ralf; Frohnmayer, Amy; Pomjanski, Natalia; Hays, Laura E; Biesterfeld, Stefan

    2017-05-24

    Fanconi anemia is a genetic bone marrow failure syndrome, variably associated with congenital anomalies and a sharply increased risk for epithelial malignancies. During the past 20 years, hematopoietic stem cell transplantation (HSCT) has dramatically improved survival. However, compared to the general population, FA patients are at greatly increased risk, and at a much younger age, for squamous cell carcinomas (SCC) of the oral cavity, esophagus and the anogenital region. The relative risk and age of onset appears to negatively correlate with HSCT in FA patients. Due to the underlying defect in DNA crosslink repair, standard chemotherapy protocols cannot be used in FA patients with SCCs. Therefore, early detection of precancerous lesions is the most promising option for long-term cure and survival. Based on oral screenings of 300 patients, we report here on the prevalence of visible oral lesions as potential precursors of oral SCCs in FA patients. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. Disrupted Signaling through the Fanconi Anemia Pathway Leads to Dysfunctional Hematopoietic Stem Cell Biology: Underlying Mechanisms and Potential Therapeutic Strategies

    PubMed Central

    Geiselhart, Anja; Lier, Amelie; Walter, Dagmar; Milsom, Michael D.

    2012-01-01

    Fanconi anemia (FA) is the most common inherited bone marrow failure syndrome. FA patients suffer to varying degrees from a heterogeneous range of developmental defects and, in addition, have an increased likelihood of developing cancer. Almost all FA patients develop a severe, progressive bone marrow failure syndrome, which impacts upon the production of all hematopoietic lineages and, hence, is thought to be driven by a defect at the level of the hematopoietic stem cell (HSC). This hypothesis would also correlate with the very high incidence of MDS and AML that is observed in FA patients. In this paper, we discuss the evidence that supports the role of dysfunctional HSC biology in driving the etiology of the disease. Furthermore, we consider the different model systems currently available to study the biology of cells defective in the FA signaling pathway and how they are informative in terms of identifying the physiologic mediators of HSC depletion and dissecting their putative mechanism of action. Finally, we ask whether the insights gained using such disease models can be translated into potential novel therapeutic strategies for the treatment of the hematologic disorders in FA patients. PMID:22675615

  5. Studies of protein-protein interactions in Fanconi anemia pathway to unravel the DNA interstrand crosslink repair mechanism.

    PubMed

    Siddiqui, Mohd Quadir; Rajpurohit, Yogendra S; Thapa, Pankaj S; Maurya, Ganesh Kumar; Banerjee, Kuheli; Khan, Mudassar Ali; Panda, Pragnya; Hasan, Syed K; Gadewal, Nikhil; Misra, Hari S; Varma, Ashok K

    2017-11-01

    Fanconi anemia (FA), a cancer predisposition syndrome exhibits hallmark feature of radial chromosome formation, and hypersensitivity to DNA crosslinking agents. A set of FA pathway proteins mainly FANCI, FANCD2 and BRCA2 are expressed to repair the covalent crosslink between the dsDNA. However, FA, BRCA pathways play an important role in DNA ICL repair as well as in homologous recombination repair, but the presumptive role of FA-BRCA proteins has not clearly explored particularly in context to function associated protein-protein interactions (PPIs). Here, in-vivo, in-vitro and in-silico studies have been performed for functionally relevant domains of FANCI, FANCD2 and BRCA2. To our conclusion, FANCI ARM repeat interacts with FANCD2 CUE domain and BRCA2 C-terminal region. Interestingly, FANCD2 CUE domain also interacts strongly with BRCA2 C-terminal region. Interactions between BRCA2 CTR and functionally relevant mutations Ser222Ala (cell cycle checkpoint mutant) and Leu231Arg (DNA ICL repair mutant) present in FANCD2 CUE domain have been analysed. To our finding, these mutations abrogate the binding between FANCD2 CUE domain and BRCA2 CTR. Furthermore, (1) different domain of FANCI, FANCD2 and BRCA2 are playing important role in PPIs, (2) mutations cause the impairment in the PPIs which in turn may disrupt the DNA ICL repair mechanism. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Upregulated LINE-1 Activity in the Fanconi Anemia Cancer Susceptibility Syndrome Leads to Spontaneous Pro-inflammatory Cytokine Production.

    PubMed

    Brégnard, Christelle; Guerra, Jessica; Déjardin, Stéphanie; Passalacqua, Frank; Benkirane, Monsef; Laguette, Nadine

    2016-06-01

    Fanconi Anemia (FA) is a genetic disorder characterized by elevated cancer susceptibility and pro-inflammatory cytokine production. Using SLX4(FANCP) deficiency as a working model, we questioned the trigger for chronic inflammation in FA. We found that absence of SLX4 caused cytoplasmic DNA accumulation, including sequences deriving from active Long INterspersed Element-1 (LINE-1), triggering the cGAS-STING pathway to elicit interferon (IFN) expression. In agreement, absence of SLX4 leads to upregulated LINE-1 retrotransposition. Importantly, similar results were obtained with the FANCD2 upstream activator of SLX4. Furthermore, treatment of FA cells with the Tenofovir reverse transcriptase inhibitor (RTi), that prevents endogenous retrotransposition, decreased both accumulation of cytoplasmic DNA and pro-inflammatory signaling. Collectively, our data suggest a contribution of endogenous RT activities to the generation of immunogenic cytoplasmic nucleic acids responsible for inflammation in FA. The additional observation that RTi decreased pro-inflammatory cytokine production induced by DNA replication stress-inducing drugs further demonstrates the contribution of endogenous RTs to sustaining chronic inflammation. Altogether, our data open perspectives in the prevention of adverse effects of chronic inflammation in tumorigenesis.

  7. Low-Dose Total-Body Irradiation and Fludarabine Phosphate Followed by Unrelated Donor Stem Cell Transplant in Treating Patients With Fanconi Anemia

    ClinicalTrials.gov

    2017-02-16

    Adult Acute Myeloid Leukemia in Remission; Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Childhood Acute Myeloid Leukemia in Remission; Childhood Myelodysplastic Syndromes; Fanconi Anemia; Previously Treated Myelodysplastic Syndromes

  8. Maternal serum alpha-fetoprotein levels are normal in Fanconi anemia: Can it be a lack of postnatal inhibition of AFP gene resulting in the elevation?

    PubMed

    Aslan, Deniz; Karabacak, Recep Onur; Aslan, Oner Deniz

    2017-04-01

    We investigated the feasibility of using serum alpha-fetoprotein (AFP) levels as a screening test for prenatal diagnosis of Fanconi anemia (FA). Serial measurements in maternal serum were recorded. Parents, both heterozygous for FA, had declined prenatal molecular testing. The infant was born with no somatic abnormalities, and FA was confirmed by postnatal molecular analysis. Maternal serum AFP levels during each trimester of pregnancy were normal indicating that these levels cannot be used as a screening test in prenatal diagnosis. Three-year follow-up after birth showed constantly elevated serum levels in the patient from the start, suggesting a lack of postnatal inhibition on AFP gene.

  9. Hydroxyurea induces chromosomal damage in G2 and enhances the clastogenic effect of mitomycin C in Fanconi anemia cells.

    PubMed

    Molina, Bertha; Marchetti, Francesco; Gómez, Laura; Ramos, Sandra; Torres, Leda; Ortiz, Rocio; Altamirano-Lozano, Mario; Carnevale, Alessandra; Frias, Sara

    2015-06-01

    Fanconi's anemia (FA) is a recessive disease; 16 genes are currently recognized in FA. FA proteins participate in the FA/BRCA pathway that plays a crucial role in the repair of DNA damage induced by crosslinking compounds. Hydroxyurea (HU) is an agent that induces replicative stress by inhibiting ribonucleotide reductase (RNR), which synthesizes deoxyribonucleotide triphosphates (dNTPs) necessary for DNA replication and repair. HU is known to activate the FA pathway; however, its clastogenic effects are not well characterized. We have investigated the effects of HU treatment alone or in sequential combination with mitomycin-C (MMC) on FA patient-derived lymphoblastoid cell lines from groups FA-A, B, C, D1/BRCA2, and E and on lymphocytes from two unclassified FA patients. All FA cells showed a significant increase (P < 0.05) in chromosomal aberrations following treatment with HU during the last 3 h before mitosis. Furthermore, when FA cells previously exposed to MMC were treated with HU, we observed an increase of MMC-induced DNA damage that was characterized by high occurrence of DNA breaks and a reduction in rejoined chromosomal aberrations. These findings show that exposure to HU during G2 induces chromosomal aberrations by a mechanism that is independent of its well-known role in replication fork stalling during S-phase and that HU interfered mainly with the rejoining process of DNA damage. We suggest that impaired oxidative stress response, lack of an adequate amount of dNTPs for DNA repair due to RNR inhibition, and interference with cell cycle control checkpoints underlie the clastogenic activity of HU in FA cells. Environ. Mol. Mutagen. 56:457-467, 2015. © 2015 Wiley Periodicals, Inc.

  10. Analysis of the pattern of expression of the Fanconi anemia group C (Facc) gene during murine development

    SciTech Connect

    Krasnoshtein, F.; Buchwald, M.

    1994-09-01

    Fanconi anemia (FA) is an autosomal recessive disorder characterized by a variety of congenital and skeletal malformations, progressive pancytopanenia and predisposition to malignancies. FA cells display chromosomal instability and hypersensitivity to DNA-damaging agents. Both the human and the corresponding murine cDNAs have been cloned in our lab. Here we describe the expression of Facc during mouse development, using mRNA in situ hybridization. Our aim is to obtain clues on the possible function of the Facc gene product during development that may help elucidate basic defect(s) in FA. In addition, knowledge of the exact pattern of Facc expression will assist in interpreting the phenotypes of mutant mice, currently being developed. In embryos the gene is diffusely expressed over the entire embryo, with higher hybridization levels in the mesenchyme and in both upper and lower extremities. Specific expression of Facc is seen in the perichondrium and marrow of long bones of hind limbs/hip; long bones of front limbs/shoulder region; developing digits of front and hind paws; and ribs. The signal is also detected in the following regions: cranial/frontal; facial/periorbital and maxillary/mandibular, hair follicles, diaphragm and lung. In addition, generalized Facc expression is seen during these embryonic stages. The pattern of Facc expression is consistent with the known skeletal abnormalities in FA patients, which include radial ray deformities, metacarpal hypoplasia, and abnormalities of lower limbs, ribs, head and face. The signal in the lung is consistent with the lung lobe absence and abnormal pulmonary drainage that have been detected in some FA patients. The sloped forehead and microcephaly in FA patients may have some association with the signal seen in the frontal region of the mouse cranium. Taken together, our results suggest that Facc is directly involved in the development of various embryonic tissues, particularly bone.

  11. Preventing over-resection by DNA2 helicase/nuclease suppresses repair defects in Fanconi anemia cells

    PubMed Central

    Karanja, Kenneth K; Lee, Eu Han; Hendrickson, Eric A; Campbell, Judith L

    2014-01-01

    FANCD2 is required for the repair of DNA damage by the FA (Fanconi anemia) pathway, and, consequently, FANCD2-deficient cells are sensitive to compounds such as cisplatin and formaldehyde that induce DNA:DNA and DNA:protein crosslinks, respectively. The DNA2 helicase/nuclease is required for RNA/DNA flap removal from Okazaki fragments during DNA replication and for the resection of DSBs (double-strand breaks) during HDR (homology-directed repair) of replication stress-induced damage. A knockdown of DNA2 renders normal cells as sensitive to cisplatin (in the absence of EXO1) and to formaldehyde (even in the presence of EXO1) as FANCD2−/− cells. Surprisingly, however, the depletion of DNA2 in FANCD2-deficient cells rescues the sensitivity of FANCD2−/− cells to cisplatin and formaldehyde. We previously showed that the resection activity of DNA2 acts downstream of FANCD2 to insure HDR of the DSBs arising when replication forks encounter ICL (interstrand crosslink) damage. The suppression of FANCD2−/− by DNA2 knockdowns suggests that DNA2 and FANCD2 also have antagonistic roles: in the absence of FANCD2, DNA2 somehow corrupts repair. To demonstrate that DNA2 is deleterious to crosslink repair, we used psoralen-induced ICL damage to trigger the repair of a site-specific crosslink in a GFP reporter and observed that “over-resection” can account for reduced repair. Our work demonstrates that excessive resection can lead to genome instability and shows that strict regulatory processes have evolved to inhibit resection nucleases. The suppression of FANCD2−/− phenotypes by DNA2 depletion may have implications for FA therapies and for the use of ICL-inducing agents in chemotherapy. PMID:24626199

  12. Genomic instability in mice is greater in Fanconi anemia caused by deficiency of Fancd2 than Fancg.

    PubMed

    Reliene, Ramune; Yamamoto, Mitsuko L; Rao, P Nagesh; Schiestl, Robert H

    2010-12-01

    Fanconi anemia (FA) results from mutations in the FANC genes and is characterized by bone marrow failure, birth defects, and a high incidence of cancer. FANCG is a part of the FA core complex that is responsible for monoubiquitination of FANCD2 and FANCI. The precise role of the FA pathway is not well understood, although it may be involved in homologous recombination (HR), nonhomologous end joining, and translesion synthesis (TLS). Fancd2(-/-) mice have a more severe phenotype than Fancg(-/-), and other FA core complex-deficient mice, although both Fancg and Fancd2 belong to the same FA pathway. We hypothesized that Fancd2 deficiency results in a more severe phenotype because Fancd2 also has a FA pathway-independent function in the maintenance of genomic integrity. To test this hypothesis, we determined the level of DNA damage and genomic instability in Fancd2(-/-), Fancg(-/-), and wild-type controls. Fancd2(-/-) mice displayed a higher magnitude of chromosomal breakage and micronucleus formation than the wild-type or Fancg(-/-) mice. Also, DNA strand breaks were increased in Fancd2(-/-) but not in Fancg(-/-) mice. In addition, Fancd2(-/-) mice displayed an elevated frequency of DNA deletions, resulting from HR at the endogenous p(un) locus. In contrast, in Fancg(-/-) mice, the frequency of DNA deletions was decreased. Thus, Fancd2 but not Fancg deficiency results in elevated chromosomal/DNA breakage and permanent genome rearrangements. This provides evidence that Fancd2 plays an additional role in the maintenance of genomic stability than Fancg, which might explain the higher predisposition to cancer seen in the Fancd2(-/-) mice.

  13. Preventing over-resection by DNA2 helicase/nuclease suppresses repair defects in Fanconi anemia cells.

    PubMed

    Karanja, Kenneth K; Lee, Eu Han; Hendrickson, Eric A; Campbell, Judith L

    2014-01-01

    FANCD2 is required for the repair of DNA damage by the FA (Fanconi anemia) pathway, and, consequently, FANCD2-deficient cells are sensitive to compounds such as cisplatin and formaldehyde that induce DNA:DNA and DNA:protein crosslinks, respectively. The DNA2 helicase/nuclease is required for RNA/DNA flap removal from Okazaki fragments during DNA replication and for the resection of DSBs (double-strand breaks) during HDR (homology-directed repair) of replication stress-induced damage. A knockdown of DNA2 renders normal cells as sensitive to cisplatin (in the absence of EXO1) and to formaldehyde (even in the presence of EXO1) as FANCD2(-/-) cells. Surprisingly, however, the depletion of DNA2 in FANCD2-deficient cells rescues the sensitivity of FANCD2(-/-) cells to cisplatin and formaldehyde. We previously showed that the resection activity of DNA2 acts downstream of FANCD2 to insure HDR of the DSBs arising when replication forks encounter ICL (interstrand crosslink) damage. The suppression of FANCD2(-/-) by DNA2 knockdowns suggests that DNA2 and FANCD2 also have antagonistic roles: in the absence of FANCD2, DNA2 somehow corrupts repair. To demonstrate that DNA2 is deleterious to crosslink repair, we used psoralen-induced ICL damage to trigger the repair of a site-specific crosslink in a GFP reporter and observed that "over-resection" can account for reduced repair. Our work demonstrates that excessive resection can lead to genome instability and shows that strict regulatory processes have evolved to inhibit resection nucleases. The suppression of FANCD2(-/-) phenotypes by DNA2 depletion may have implications for FA therapies and for the use of ICL-inducing agents in chemotherapy.

  14. FANCD2, FANCJ and BRCA2 cooperate to promote replication fork recovery independently of the Fanconi Anemia core complex.

    PubMed

    Raghunandan, Maya; Chaudhury, Indrajit; Kelich, Stephanie L; Hanenberg, Helmut; Sobeck, Alexandra

    2015-01-01

    Fanconi Anemia (FA) is an inherited multi-gene cancer predisposition syndrome that is characterized on the cellular level by a hypersensitivity to DNA interstrand crosslinks (ICLs). To repair these lesions, the FA pathway proteins are thought to act in a linear hierarchy: Following ICL detection, an upstream FA core complex monoubiquitinates the central FA pathway members FANCD2 and FANCI, followed by their recruitment to chromatin. Chromatin-bound monoubiquitinated FANCD2 and FANCI subsequently coordinate DNA repair factors including the downstream FA pathway members FANCJ and FANCD1/BRCA2 to repair the DNA ICL. Importantly, we recently showed that FANCD2 has additional independent roles: it binds chromatin and acts in concert with the BLM helicase complex to promote the restart of aphidicolin (APH)-stalled replication forks, while suppressing the firing of new replication origins. Here, we show that FANCD2 fulfills these roles independently of the FA core complex-mediated monoubiquitination step. Following APH treatment, nonubiquitinated FANCD2 accumulates on chromatin, recruits the BLM complex, and promotes robust replication fork recovery regardless of the absence or presence of a functional FA core complex. In contrast, the downstream FA pathway members FANCJ and BRCA2 share FANCD2's role in replication fork restart and the suppression of new origin firing. Our results support a non-linear FA pathway model at stalled replication forks, where the nonubiquitinated FANCD2 isoform - in concert with FANCJ and BRCA2 - fulfills a specific function in promoting efficient replication fork recovery independently of the FA core complex.

  15. Rad18 E3 ubiquitin ligase activity mediates Fanconi anemia pathway activation and cell survival following DNA Topoisomerase 1 inhibition.

    PubMed

    Palle, Komaraiah; Vaziri, Cyrus

    2011-05-15

    Camptothecin (CPT) and related chemotherapeutic drugs induce formation of DNA Topoisomerase I (Top1) covalent or cleavage complexes (Top1ccs) that block leading-strand DNA synthesis and elicit DNA Double Stranded Breaks (DSB) during S phase. The Fanconi Anemia (FA) pathway is implicated in tolerance of CPT-induced DNA damage yet the mechanism of FA pathway activation by Top1 poisons has not been studied. We show here that the FA core complex protein FANCA and monoubiquitinated FANCD2 (an effector of the FA pathway) are rapidly mobilized to chromatin in response to CPT treatment in several human cancer cell lines and untransformed primary human dermal fibroblasts. FANCD2 depletion using siRNA leads to impaired recovery from CPT-induced inhibition or DNA synthesis, persistence of γH2AX (a DSB marker) and reduced cell survival following CPT treatment. The E3 ubiquitin ligase Rad18 is necessary for CPT-induced recruitment of FANCA and FANCD2 to chromatin. Moreover, Rad18-depletion recapitulates the DNA synthesis and survival defects of FANCD2-deficiency in CPT-treated cells. It is well-established that Rad18 promotes FA pathway activation and DNA damage tolerance in response to bulky DNA lesions via a mechanism involving PCNA monoubiquitination. In contrast, PCNA monoubiquitination is not involved in Rad18-mediated FA pathway activation or cell survival following acquisition of CPT-induced DSB. Moreover, while Rad18 is implicated in recombinational repair of DSB via an E3 ligase-independent mechanism, we demonstrate that Rad18 E3 ligase activity is essential for appropriate FA pathway activation and DNA damage tolerance after CPT treatment. Taken together, our results define a novel pathway of Rad18-dependent DSB repair that is dissociable from known Rad18-mediated DNA repair mechanisms based on its independence from PCNA ubiquitination and requirement for E3 ligase activity.

  16. EGFR-activating mutations correlate with a Fanconi anemia-like cellular phenotype that includes PARP inhibitor sensitivity.

    PubMed

    Pfäffle, Heike N; Wang, Meng; Gheorghiu, Liliana; Ferraiolo, Natalie; Greninger, Patricia; Borgmann, Kerstin; Settleman, Jeffrey; Benes, Cyril H; Sequist, Lecia V; Zou, Lee; Willers, Henning

    2013-10-15

    In patients with lung cancer whose tumors harbor activating mutations in the EGF receptor (EGFR), increased responses to platinum-based chemotherapies are seen compared with wild-type cancers. However, the mechanisms underlying this association have remained elusive. Here, we describe a cellular phenotype of cross-linker sensitivity in a subset of EGFR-mutant lung cancer cell lines that is reminiscent of the defects seen in cells impaired in the Fanconi anemia pathway, including a pronounced G2-M cell-cycle arrest and chromosomal radial formation. We identified a defect downstream of FANCD2 at the level of recruitment of FAN1 nuclease and DNA interstrand cross-link (ICL) unhooking. The effect of EGFR mutation was epistatic with FANCD2. Consistent with the known role of FANCD2 in promoting RAD51 foci formation and homologous recombination repair (HRR), EGFR-mutant cells also exhibited an impaired RAD51 foci response to ICLs, but not to DNA double-strand breaks. EGFR kinase inhibition affected RAD51 foci formation neither in EGFR-mutant nor wild-type cells. In contrast, EGFR depletion or overexpression of mutant EGFR in wild-type cells suppressed RAD51 foci, suggesting an EGFR kinase-independent regulation of DNA repair. Interestingly, EGFR-mutant cells treated with the PARP inhibitor olaparib also displayed decreased FAN1 foci induction, coupled with a putative block in a late HRR step. As a result, EGFR-mutant lung cancer cells exhibited olaparib sensitivity in vitro and in vivo. Our findings provide insight into the mechanisms of cisplatin and PARP inhibitor sensitivity of EGFR-mutant cells, yielding potential therapeutic opportunities for further treatment individualization in this genetically defined subset of lung cancer.

  17. Regulation of the activation of the Fanconi anemia pathway by the p21 cyclin-dependent kinase inhibitor.

    PubMed

    Rego, M A; Harney, J A; Mauro, M; Shen, M; Howlett, N G

    2012-01-19

    Fanconi anemia (FA) is a rare disease characterized by congenital defects, progressive bone marrow failure and heightened cancer susceptibility. The FA proteins, BRCA1 and FANCD1/BRCA2 function cooperatively in the FA-BRCA pathway to repair damaged DNA. Activation of the FA-BRCA pathway occurs via the monoubiquitination of the FANCD2 and FANCI proteins, targeting these proteins to discrete nuclear foci where they function in DNA repair. The cellular regulation of FANCD2/I monoubiquitination, however, remains poorly understood. In this study, we have examined the roles of the p53 tumor suppressor protein, as well as its downstream target, the p21(Cip1/Waf1) cyclin-dependent kinase inhibitor, in the regulation of the activation of the FA-BRCA pathway. We demonstrate that, in contrast to p53, p21 has a major role in the regulation of the activation of the FA-BRCA pathway: p21 promotes S-phase and DNA damage-inducible FANCD2/I monoubiquitination and nuclear foci formation. Several lines of evidence establish that this effect is not a consequence of a defective G1-S checkpoint or altered cell-cycle progression in the absence of p21. Instead, we demonstrate that p21 is required for the transcriptional repression of the USP1 deubiquitinating enzyme upon exposure to DNA-damaging agents. In the absence of p21, persistent USP1 expression precludes the DNA damage-inducible accumulation of monoubiquitinated FANCD2 and FANCI. Consequently, p21(-/-) cells exhibit increased levels of mitomycin C-inducible complex chromosomal aberrations and elevated γH2AX nuclear foci formation. Our results demonstrate that p21 has a critical role in the regulation of the activation of the FA-BRCA pathway and suggest a broader role for p21 in the orchestration of DNA repair processes following exposure to DNA crosslinking agents.

  18. Genomic instability in mice is greater in Fanconi anemia caused by deficiency of Fancd2 than Fancg

    PubMed Central

    Reliene, Ramune; Yamamoto, Mitsuko L.; Rao, P. Nagesh; Schiestl, Robert H.

    2010-01-01

    Fanconi anemia (FA) results from mutations in the FANC genes and is characterized by bone marrow failure, birth defects and a high incidence of cancer. FANCG is a part of the FA core complex that is responsible for monoubiquitination of FANCD2 and FANCI. The precise role of the FA pathway is not well understood, although it may be involved in homologous recombination (HR), non-homologous end joining (NHEJ) and translesion synthesis (TLS). Fancd2−/− mice have a more severe phenotype than Fancg−/− and other FA core complex deficient mice, although both Fancg and Fancd2 belong to the same FA pathway. We hypothesized that Fancd2 deficiency results in a more severe phenotype because Fancd2 also has a FA pathway-independent function in the maintenance of genomic integrity. To test this hypothesis we determined the level of DNA damage and genomic instability in Fancd2−/−, Fancg−/− and wildtype controls. Fancd2−/− mice displayed a higher magnitude of chromosomal breakage and micronucleus formation than wildtype or Fancg−/− mice. Also, DNA strand breaks were increased in Fancd2−/− but not in Fancg−/− mice. In addition, Fancd2−/− mice displayed an elevated frequency of DNA deletions resulting from HR at the endogenous pun locus. In contrast, in Fancg−/− mice, the frequency of DNA deletions was decreased. Thus, Fancd2 but not Fancg deficiency results in elevated chromosomal/DNA breakage and permanent genome rearrangements. This provides evidence that Fancd2 plays an additional role in the maintenance of genomic stability than Fancg, which might explain the higher predisposition to cancer seen in the Fancd2−/− mice. PMID:21118969

  19. FANCD2, FANCJ and BRCA2 cooperate to promote replication fork recovery independently of the Fanconi Anemia core complex

    PubMed Central

    Raghunandan, Maya; Chaudhury, Indrajit; Kelich, Stephanie L.; Hanenberg, Helmut; Sobeck, Alexandra

    2015-01-01

    Fanconi Anemia (FA) is an inherited multi-gene cancer predisposition syndrome that is characterized on the cellular level by a hypersensitivity to DNA interstrand crosslinks (ICLs). To repair these lesions, the FA pathway proteins are thought to act in a linear hierarchy: Following ICL detection, an upstream FA core complex monoubiquitinates the central FA pathway members FANCD2 and FANCI, followed by their recruitment to chromatin. Chromatin-bound monoubiquitinated FANCD2 and FANCI subsequently coordinate DNA repair factors including the downstream FA pathway members FANCJ and FANCD1/BRCA2 to repair the DNA ICL. Importantly, we recently showed that FANCD2 has additional independent roles: it binds chromatin and acts in concert with the BLM helicase complex to promote the restart of aphidicolin (APH)-stalled replication forks, while suppressing the firing of new replication origins. Here, we show that FANCD2 fulfills these roles independently of the FA core complex-mediated monoubiquitination step. Following APH treatment, nonubiquitinated FANCD2 accumulates on chromatin, recruits the BLM complex, and promotes robust replication fork recovery regardless of the absence or presence of a functional FA core complex. In contrast, the downstream FA pathway members FANCJ and BRCA2 share FANCD2's role in replication fork restart and the suppression of new origin firing. Our results support a non-linear FA pathway model at stalled replication forks, where the nonubiquitinated FANCD2 isoform – in concert with FANCJ and BRCA2 – fulfills a specific function in promoting efficient replication fork recovery independently of the FA core complex. PMID:25659033

  20. Founder haplotype analysis of Fanconi anemia in the Korean population finds common ancestral haplotypes for a FANCG variant.

    PubMed

    Park, Joonhong; Kim, Myungshin; Jang, Woori; Chae, Hyojin; Kim, Yonggoo; Chung, Nack-Gyun; Lee, Jae-Wook; Cho, Bin; Jeong, Dae-Chul; Park, In Yang; Park, Mi Sun

    2015-05-01

    A common ancestral haplotype is strongly suggested in the Korean and Japanese patients with Fanconi anemia (FA), because common mutations have been frequently found: c.2546delC and c.3720_3724delAAACA of FANCA; c.307+1G>C, c.1066C>T, and c.1589_1591delATA of FANCG. Our aim in this study was to investigate the origin of these common mutations of FANCA and FANCG. We genotyped 13 FA patients consisting of five FA-A patients and eight FA-G patients from the Korean FA population. Microsatellite markers used for haplotype analysis included four CA repeat markers which are closely linked with FANCA and eight CA repeat markers which are contiguous with FANCG. As a result, Korean FA-A patients carrying c.2546delC or c.3720_3724delAAACA did not share the same haplotypes. However, three unique haplotypes carrying c.307+1G>C, c.1066C > T, or c.1589_1591delATA, that consisted of eight polymorphic loci covering a flanking region were strongly associated with Korean FA-G, consistent with founder haplotypes reported previously in the Japanese FA-G population. Our finding confirmed the common ancestral haplotypes on the origins of the East Asian FA-G patients, which will improve our understanding of the molecular population genetics of FA-G. To the best of our knowledge, this is the first report on the association between disease-linked mutations and common ancestral haplotypes in the Korean FA population.

  1. HLA-haploidentical T cell-depleted allogeneic hematopoietic stem cell transplantation in children with Fanconi anemia.

    PubMed

    Zecca, Marco; Strocchio, Luisa; Pagliara, Daria; Comoli, Patrizia; Bertaina, Alice; Giorgiani, Giovanna; Perotti, Cesare; Corbella, Franco; Brescia, Letizia; Locatelli, Franco

    2014-04-01

    We report the outcome of 12 consecutive pediatric patients with Fanconi anemia (FA) who had neither an HLA-identical sibling nor an HLA-matched unrelated donor and who were given T cell-depleted, CD34(+) positively selected cells from a haploidentical related donor after a reduced-intensity, fludarabine-based conditioning regimen. Engraftment was achieved in 9 of 12 patients (75%), and the cumulative incidence of graft rejection was 17% (95% confidence interval [CI], 5% to 59%). Cumulative incidences of grades II to IV acute and chronic graft-versus-host disease were 17% (95% CI, 5% to 59%) and 35% (95% CI, 14% to 89%), respectively. The conditioning regimen was well tolerated, with no fatal regimen-related toxicity and 3 cases of grade III regimen-related toxicity. The cumulative incidence of transplant-related mortality was 17% (95% CI, 5% to 59%). The 5-year overall survival, event-free survival, and disease-free survival were 83% (95% CI, 62% to 100%), 67% (95% CI, 40% to 93%), and 83% (95% CI, 62% to 100%), respectively. These data demonstrate that a fludarabine-based conditioning regimen, followed by infusion of high doses of T cell-depleted stem cells, is able to ensure engraftment with good overall survival and disease-free survival, confirming the feasibility of haploidentical hematopoietic stem cell transplantation in FA. To the best of our knowledge, this is the largest series of hematopoietic stem cell transplantation from a haploidentical related donor in FA patients reported to date. Copyright © 2014 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  2. Genetic inactivation of the Fanconi anemia gene FANCC identified in the hepatocellular carcinoma cell line HuH-7 confers sensitivity towards DNA-interstrand crosslinking agents

    PubMed Central

    2010-01-01

    Background Inactivation of the Fanconi anemia (FA) pathway through defects in one of 13 FA genes occurs at low frequency in various solid cancer entities among the general population. As FA pathway inactivation confers a distinct hypersensitivity towards DNA interstrand-crosslinking (ICL)-agents, FA defects represent rational targets for individualized therapeutic strategies. Except for pancreatic cancer, however, the prevalence of FA defects in gastrointestinal (GI) tumors has not yet been systematically explored. Results A panel of GI cancer cell lines was screened for FA pathway inactivation applying FANCD2 monoubiquitination and FANCD2/RAD51 nuclear focus formation and a newly identified FA pathway-deficient cell line was functionally characterized. The hepatocellular carcinoma (HCC) line HuH-7 was defective in FANCD2 monoubiquitination and FANCD2 nuclear focus formation but proficient in RAD51 focus formation. Gene complementation studies revealed that this proximal FA pathway inactivation was attributable to defective FANCC function in HuH-7 cells. Accordingly, a homozygous inactivating FANCC nonsense mutation (c.553C > T, p.R185X) was identified in HuH-7, resulting in partial transcriptional skipping of exon 6 and leading to the classic cellular FA hypersensitivity phenotype; HuH-7 cells exhibited a strongly reduced proliferation rate and a pronounced G2 cell cycle arrest at distinctly lower concentrations of ICL-agents than a panel of non-isogenic, FA pathway-proficient HCC cell lines. Upon retroviral transduction of HuH-7 cells with FANCC cDNA, FA pathway functions were restored and ICL-hypersensitivity abrogated. Analyses of 18 surgical HCC specimens yielded no further examples for genetic or epigenetic inactivation of FANCC, FANCF, or FANCG in HCC, suggesting a low prevalence of proximal FA pathway inactivation in this tumor type. Conclusions As the majority of HCC are chemoresistant, assessment of FA pathway function in HCC could identify small

  3. De Novo Chromosome Copy Number Variation in Fanconi Anemia-Associated Hematopoietic Defects

    DTIC Science & Technology

    2013-04-01

    We have confirmed re-expression of FANCA, FANCD2 , and FANCG in the FA-A + FANCA, FA-D2 + FANCD2 , and FA-G + FANCG cells, respectively. We have also...confirmed restoration of FANCD2 and FANCI monoubiquitination and functional complementation of the FA-A + FANCA and FA-D2 + FANCD2 cells. In...de novo CNVs Task 1. Correction of FA-A, FA-C, and FA-D2 hTERT cells with pLenti6.2/V5-FANCA, -FANCC, and FANCD2 , respectively. Sub-task 1

  4. Lung Cancer Cell Line Screen Links Fanconi Anemia/BRCA Pathway Defects to Increased Relative Biological Effectiveness of Proton Radiation

    SciTech Connect

    Liu, Qi; Ghosh, Priyanjali; Magpayo, Nicole; Testa, Mauro; Tang, Shikui; Gheorghiu, Liliana; Biggs, Peter; Paganetti, Harald; Efstathiou, Jason A.; Lu, Hsiao-Ming; Held, Kathryn D.; Willers, Henning

    2015-04-01

    Purpose: Growing knowledge of genomic heterogeneity in cancer, especially when it results in altered DNA damage responses, requires re-examination of the generic relative biological effectiveness (RBE) of 1.1 of protons. Methods and Materials: For determination of cellular radiosensitivity, we irradiated 17 lung cancer cell lines at the mid-spread-out Bragg peak of a clinical proton beam (linear energy transfer, 2.5 keV/μm). For comparison, 250-kVp X rays and {sup 137}Cs γ-rays were used. To estimate the RBE of protons relative to {sup 60}Co (Co60eq), we assigned an RBE(Co60Eq) of 1.1 to X rays to correct the physical dose measured. Standard DNA repair foci assays were used to monitor damage responses. FANCD2 was depleted using RNA interference. Results: Five lung cancer cell lines (29.4%) exhibited reduced clonogenic survival after proton irradiation compared with X-irradiation with the same physical doses. This was confirmed in a 3-dimensional sphere assay. Corresponding proton RBE(Co60Eq) estimates were statistically significantly different from 1.1 (P≤.05): 1.31 to 1.77 (for a survival fraction of 0.5). In 3 of these lines, increased RBE was correlated with alterations in the Fanconi anemia (FA)/BRCA pathway of DNA repair. In Calu-6 cells, the data pointed toward an FA pathway defect, leading to a previously unreported persistence of proton-induced RAD51 foci. The FA/BRCA-defective cells displayed a 25% increase in the size of subnuclear 53BP1 foci 18 hours after proton irradiation. Conclusions: Our cell line screen has revealed variations in proton RBE that are partly due to FA/BRCA pathway defects, suggesting that the use of a generic RBE for cancers should be revisited. We propose that functional biomarkers, such as size of residual 53BP1 foci, may be used to identify cancers with increased sensitivity to proton radiation.

  5. Rare cytogenetic abnormalities in acute myeloid leukemia transformed from Fanconi anemia – a case report

    PubMed Central

    2013-01-01

    Background Fanconi’s anemia (FA) is an inherited bone marrow failure syndrome that carries a higher risk of transformation to acute myeloid leukemia (AML) when compared with general population. AML is the initial presentation in approximately one third of patients. Case presentation A 17 year old male presented to the emergency room with history of high grade fever since two weeks. Examination revealed pallor, short stature and thumb polydactyly. There was no visceromegaly or lymphadenopathy. Complete blood count showed haemoglobin 3.4 gm/dl, MCV 100 fl and MCH 36 pg, white blood cell count 55.9 × 10 E9/L and platelet count 8 × 10E9/L. Peripheral blood smear revealed 26% blast cells. Bone marrow was hypercellular exhibiting infiltration with 21% blast cells. Auer rods were seen in few blast cells. These findings were consistent with acute myelomonocytic leukemia. These blasts cells expressed CD33, CD13, HLA-DR, CD117, CD34 antigens and cytoplasmic myeloperoxidase on immunophenotyping. Bone marrow cytogenetics revealed 46, XY, t (8:21) (q22; q22) [11] / 46, XY, add (2) (q37), t (8; 21) [4] / 46, XY [5]. Molecular studies showed positivity of FLT 3 D835 variant and negativity of NPM 1 and FLT3 ITD (internal tandem domain) mutation. Peripheral blood analysis for chromosomal breakage exhibited tri-radial and complex figures. He received induction chemotherapy with cytarabine and daunorubicin (3 + 7). Day 14 marrow revealed clearance of blast cells. Conclusion The recognition of specific cytogenetic abnormalities present in FA known to predispose to AML is crucial for early haematopoietic stem cell transplant (HSCT) before transformation to leukemia. PMID:23937881

  6. What Causes Aplastic Anemia?

    MedlinePlus

    ... to aplastic anemia. Examples include Fanconi anemia , Shwachman-Diamond syndrome, dyskeratosis (DIS-ker-ah-TO-sis) congenita, and Diamond-Blackfan anemia. Rate This Content: NEXT >> Featured Video ...

  7. Treatment of Fanconi anemia patients using fludarabine and low-dose total body irradiation followed by unrelated donor hematopoietic cell transplantation

    PubMed Central

    Thakar, Monica S; Kurre, Peter; Storb, Rainer; Kletzel, Morris; Frangoul, Haydar; Pulsipher, Michael A.; Leisenring, Wendy; Flowers, Mary Evelyn D; Sandmaier, Brenda M; Woolfrey, Ann; Kiem, Hans-Peter

    2010-01-01

    A non-myeloablative conditioning regimen consisting of fludarabine (FLU) and 2 Gy total body irradiation (TBI) has been used with great experience and engraftment success without promoting excessive non-relapse mortality (NRM) in medically infirm patients requiring hematopoietic cell transplantation (HCT). Here, we studied this same low-toxicity regimen as a means to promote engraftment of unrelated donor peripheral blood stem cells (PBSC) in patients with Fanconi Anemia (FA). All patients tolerated the regimen well with no mucositis or other severe toxicity. Of six patients transplanted, five achieved stable mixed or full donor chimerism. Acute and chronic graft-versus-host disease (GVHD) occurred in four and three patients, respectively. Three patients are alive and well a median of 45.9 (range, 20.9–68.1) months after transplant. In summary, this FLU-based regimen facilitates stable engraftment of unrelated PBSC but is associated with significant chronic GVHD. PMID:20581880

  8. Repair pathways independent of the Fanconi anemia nuclear core complex play a predominant role in mitigating formaldehyde-induced DNA damage

    SciTech Connect

    Noda, Taichi; Takahashi, Akihisa; Kondo, Natsuko; Mori, Eiichiro; Okamoto, Noritomo; Nakagawa, Yosuke; Ohnishi, Ken; Zdzienicka, Malgorzata Z.; Thompson, Larry H.; Helleday, Thomas; Asada, Hideo; and others

    2011-01-07

    The role of the Fanconi anemia (FA) repair pathway for DNA damage induced by formaldehyde was examined in the work described here. The following cell types were used: mouse embryonic fibroblast cell lines FANCA{sup -/-}, FANCC{sup -/-}, FANCA{sup -/-}C{sup -/-}, FANCD2{sup -/-} and their parental cells, the Chinese hamster cell lines FANCD1 mutant (mt), FANCGmt, their revertant cells, and the corresponding wild-type (wt) cells. Cell survival rates were determined with colony formation assays after formaldehyde treatment. DNA double strand breaks (DSBs) were detected with an immunocytochemical {gamma}H2AX-staining assay. Although the sensitivity of FANCA{sup -/-}, FANCC{sup -/-} and FANCA{sup -/-}C{sup -/-} cells to formaldehyde was comparable to that of proficient cells, FANCD1mt, FANCGmt and FANCD2{sup -/-} cells were more sensitive to formaldehyde than the corresponding proficient cells. It was found that homologous recombination (HR) repair was induced by formaldehyde. In addition, {gamma}H2AX foci in FANCD1mt cells persisted for longer times than in FANCD1wt cells. These findings suggest that formaldehyde-induced DSBs are repaired by HR through the FA repair pathway which is independent of the FA nuclear core complex. -- Research highlights: {yields} We examined to clarify the repair pathways of formaldehyde-induced DNA damage. Formaldehyde induces DNA double strand breaks (DSBs). {yields} DSBs are repaired through the Fanconi anemia (FA) repair pathway. {yields} This pathway is independent of the FA nuclear core complex. {yields} We also found that homologous recombination repair was induced by formaldehyde.

  9. Alcohol metabolism in human cells causes DNA damage and activates the Fanconi anemia – breast cancer susceptibility (FA-BRCA) DNA damage response network

    PubMed Central

    Abraham, Jessy; Balbo, Silvia; Crabb, David; Brooks, P.J.

    2011-01-01

    Background We recently reported that exposure of human cells in vitro to acetaldehyde resulted in activation of the Fanconi anemia-breast cancer associated (FA-BRCA) DNA damage response network. Methods To determine whether intracellular generation of acetaldehyde from ethanol metabolism can cause DNA damage and activate the FA-BRCA network, we engineered HeLa cells to metabolize alcohol by expression of human alcohol dehydrogenase 1B. Results Incubation of HeLa-ADH1B cells with ethanol (20 mM) resulted in acetaldehyde accumulation in the media which was prevented by co-incubation with 4-methyl pyrazole (4-MP), a specific inhibitor of ADH. Ethanol treatment of HeLa-ADH1B cells produced a 4-fold increase in the acetaldehyde-DNA adduct, N2-ethylidene-dGuo, and also resulted in activation of the Fanconi anemia -breast cancer susceptibility (FA-BRCA) DNA damage response network, as indicated by a monoubiquitination of FANCD2, and phosphorylation of BRCA1. Ser 1524 was identified as one site of BRCA1 phosphorylation. The increased levels of DNA adducts, FANCD2 monoubiquitination, and BRCA1 phosphorylation were all blocked by 4-MP, indicating that acetaldehyde, rather than ethanol itself, was responsible for all three responses. Importantly, the ethanol concentration we used is within the range that can be attained in the human body during social drinking. Conclusions Our results indicate that intracellular metabolism of ethanol to acetaldehyde results in DNA damage which activates the FA-BRCA DNA damage response network. PMID:21919919

  10. Fanconi anemia A is a nucleocytoplasmic shuttling molecule required for gonadotropin-releasing hormone (GnRH) transduction of the GnRH receptor.

    PubMed

    Larder, Rachel; Karali, Dimitra; Nelson, Nancy; Brown, Pamela

    2006-12-01

    GnRH binds its cognate G protein-coupled GnRH receptor (GnRHR) located on pituitary gonadotropes and drives expression of gonadotropin hormones. There are two gonadotropin hormones, comprised of a common alpha- and hormone-specific beta-subunit, which are required for gonadal function. Recently we identified that Fanconi anemia a (Fanca), a DNA damage repair gene, is differentially expressed within the LbetaT2 gonadotrope cell line in response to stimulation with GnRH. FANCA is mutated in more than 60% of cases of Fanconi anemia (FA), a rare genetically heterogeneous autosomal recessive disorder characterized by bone marrow failure, endocrine tissue cancer susceptibility, and infertility. Here we show that induction of FANCA protein is mediated by the GnRHR and that the protein constitutively adopts a nucleocytoplasmic intracellular distribution pattern. Using inhibitors to block nuclear import and export and a GnRHR antagonist, we demonstrated that GnRH induces nuclear accumulation of FANCA and green fluorescent protein (GFP)-FANCA before exporting back to the cytoplasm using the nuclear export receptor CRM1. Using FANCA point mutations that locate GFP-FANCA to the cytoplasm (H1110P) or functionally uncouple GFP-FANCA (Q1128E) from the wild-type nucleocytoplasmic distribution pattern, we demonstrated that wild-type FANCA was required for GnRH-induced activation of gonadotrope cell markers. Cotransfection of H1110P and Q1128E blocked GnRH activation of the alphaGsu and GnRHR but not the beta-subunit gene promoters. We conclude that nucleocytoplasmic shuttling of FANCA is required for GnRH transduction of the alphaGSU and GnRHR gene promoters and propose that FANCA functions as a GnRH-induced signal transducer.

  11. What Is Fanconi Anemia?

    MedlinePlus

    ... much more likely than others to develop cancerous solid tumors. The risk of solid tumors increases with age in people who have ... to FA are bone marrow failure, leukemia, and solid tumors. Advances in care and treatment have improved ...

  12. A novel role for Fanconi anemia (FA) pathway effector protein FANCD2 in cell cycle progression of untransformed primary human cells.

    PubMed

    Song, Ihn Young; Barkley, Laura R; Day, Tovah A; Weiss, Robert S; Vaziri, Cyrus

    2010-06-15

    Fanconi Anemia (FA) is a cancer-susceptibility syndrome characterized by cellular sensitivity to DNA inter-strand cross-link (ICL)-inducing agents. The Fanconia Anemia D2 (FANCD2) protein is implicated in repair of various forms of DNA damage including ICLs. Studies with replicating extracts from Xenopus eggs indicate a role for FANCD2 in processing and repair of DNA replication-associated double stranded breaks (DSB). We have investigated the role of FANCD2 in cell cycle progression of cultured human cells. Similar to Xenopus cell-free extracts, we show that chromatin association of FANCD2 in human cells is coupled to ongoing DNA replication. siRNA depletion experiments demonstrate that FANCD2 is necessary for efficient DNA synthesis. However, in contrast with Xenopus extracts, FANCD2-deficiency does not elicit a DNA damage response, and does not affect the elongation phase of DNA synthesis, suggesting that FANCD2 is dispensable for repair of replication-associated DNA damage. Using synchronized cultures of primary untransformed human dermal fibroblasts we demonstrate that FANCD2 is necessary for efficient initiation of DNA synthesis. Taken together, our results suggest a novel role for the FA pathway in regulation of DNA synthesis and cell cycle progression. Inefficient DNA replication may contribute to the genome instability and cancer-propensity of FA patients.

  13. Loss of Dependence on Continued Expression of the Human Papillomavirus 16 E7 Oncogene in Cervical Cancers and Precancerous Lesions Arising in Fanconi Anemia Pathway-Deficient Mice.

    PubMed

    Park, Soyeong; Park, Jung Wook; Pitot, Henry C; Lambert, Paul F

    2016-05-17

    Fanconi anemia (FA) is a rare genetic disorder caused by defects in DNA damage repair. FA patients often develop squamous cell carcinoma (SCC) at sites where high-risk human papillomaviruses (HPVs) are known to cause cancer, including the cervix. However, SCCs found in human FA patients are often HPV negative, even though the majority of female FA patients with anogenital cancers had preexisting HPV-positive dysplasia. We hypothesize that HPVs contribute to the development of SCCs in FA patients but that the continued expression of HPV oncogenes is not required for the maintenance of the cancer state because FA deficiency leads to an accumulation of mutations in cellular genes that render the cancer no longer dependent upon viral oncogenes. We tested this hypothesis, making use of Bi-L E7 transgenic mice in which we temporally controlled expression of HPV16 E7, the dominant viral oncogene in HPV-associated cancers. As seen before, the persistence of cervical neoplastic disease was highly dependent upon the continued expression of HPV16 E7 in FA-sufficient mice. However, in mice with FA deficiency, cervical cancers persisted in a large fraction of the mice after HPV16 E7 expression was turned off, indicating that these cancers had escaped from their dependency on E7. Furthermore, the severity of precancerous lesions also failed to be reduced significantly in the mice with FA deficiency upon turning off expression of E7. These findings confirm our hypothesis and may explain the fact that, while FA patients have a high frequency of infections by HPVs and HPV-induced precancerous lesions, the cancers are frequently HPV negative. IMPORTANCE  : Fanconi anemia (FA) patients are at high risk for developing squamous cell carcinoma (SCC) at sites where high-risk human papillomaviruses (HPVs) frequently cause cancer. Yet these SCCs are often HPV negative. FA patients have a genetic defect in their capacity to repair damaged DNA. HPV oncogenes cause an accumulation of DNA

  14. Loss of Dependence on Continued Expression of the Human Papillomavirus 16 E7 Oncogene in Cervical Cancers and Precancerous Lesions Arising in Fanconi Anemia Pathway-Deficient Mice

    PubMed Central

    Park, Soyeong; Park, Jung Wook; Pitot, Henry C.

    2016-01-01

    ABSTRACT   Fanconi anemia (FA) is a rare genetic disorder caused by defects in DNA damage repair. FA patients often develop squamous cell carcinoma (SCC) at sites where high-risk human papillomaviruses (HPVs) are known to cause cancer, including the cervix. However, SCCs found in human FA patients are often HPV negative, even though the majority of female FA patients with anogenital cancers had preexisting HPV-positive dysplasia. We hypothesize that HPVs contribute to the development of SCCs in FA patients but that the continued expression of HPV oncogenes is not required for the maintenance of the cancer state because FA deficiency leads to an accumulation of mutations in cellular genes that render the cancer no longer dependent upon viral oncogenes. We tested this hypothesis, making use of Bi-L E7 transgenic mice in which we temporally controlled expression of HPV16 E7, the dominant viral oncogene in HPV-associated cancers. As seen before, the persistence of cervical neoplastic disease was highly dependent upon the continued expression of HPV16 E7 in FA-sufficient mice. However, in mice with FA deficiency, cervical cancers persisted in a large fraction of the mice after HPV16 E7 expression was turned off, indicating that these cancers had escaped from their dependency on E7. Furthermore, the severity of precancerous lesions also failed to be reduced significantly in the mice with FA deficiency upon turning off expression of E7. These findings confirm our hypothesis and may explain the fact that, while FA patients have a high frequency of infections by HPVs and HPV-induced precancerous lesions, the cancers are frequently HPV negative. Importance   Fanconi anemia (FA) patients are at high risk for developing squamous cell carcinoma (SCC) at sites where high-risk human papillomaviruses (HPVs) frequently cause cancer. Yet these SCCs are often HPV negative. FA patients have a genetic defect in their capacity to repair damaged DNA. HPV oncogenes cause an

  15. Alcohol induces DNA damage and the Fanconi anemia D2 protein implicating FANCD2 in the DNA damage response pathways in brain.

    PubMed

    Rulten, S L; Hodder, E; Ripley, T L; Stephens, D N; Mayne, L V

    2008-07-01

    The largest cause of neurological damage to children is prenatal exposure to alcohol and chronic alcohol use in adults is associated with neurodegeneration, dementia and long-term behavioral changes. Microarray analysis identified the DNA damage response (DDR) gene, Fanconi anemia (Fanc) D2, to be robustly upregulated in mouse midbrain following 24-hour in vivo exposure to ethanol. In this study, we investigate the ability of ethanol to generate DNA strand breaks, predicted substrates for the Fanc pathway and the potential role of FANCD2 in the DDR to ethanol in brain. The effect of ethanol on FANCD2 mRNA levels was measured by quantitative real time PCR using mouse brain and human neuronal cells. FANCD2 protein levels and ubiquitination were measured by Western blotting and immunocytochemistry. DNA damage induction by ethanol/acetaldehyde was measured using the Comet assay and gamma H2AX immunocytochemistry. Levels of DNA and RNA synthesis were measured in cell strains using (3)H-thymidine or (3)H-uridine up-take. Chronic exposure to ethanol induced FANCD2 in mouse midbrain in vivo and in the nucleus of human neuronal cells in culture. However, there was no concomitant increase in the amount of ubiquitinated FANCD2. Acetaldehyde also induced nonubiquitinated FANCD2 protein, and we were able to demonstrate the ability of acetaldehyde to generate DNA double strand breaks, lesions which normally induce ubiquitination of FANCD2. Ethanol also inhibited both RNA and DNA synthesis in proliferating cells consistent with effects on transcription and replication. In contrast to other DNA damaging agents, ethanol/acetaldehyde generated DNA strand breaks without inducing ubiquitination of FANCD2, despite increasing protein levels in the nucleus. These data are consistent with recent reports that suggest the Fanconi anemia pathway plays an important role in the adult brain in response to DNA damage. Further work is required to establish what this role is, in particular the

  16. Mutational analysis of FANCL, FANCM and the recently identified FANCI suggests that among the 13 known Fanconi Anemia genes, only FANCD1/BRCA2 plays a major role in high-risk breast cancer predisposition.

    PubMed

    García, María J; Fernández, Victoria; Osorio, Ana; Barroso, Alicia; Fernández, Fernando; Urioste, Miguel; Benítez, Javier

    2009-11-01

    Fanconi Anemia (FA) is a rare recessive syndrome characterized by cellular hypersensitivity to DNA-cross-linking agents. To date, 13 FA complementation groups have been described and all 13 genes associated to each of these groups have been currently identified. Three of the known FA genes are also high-risk (FANCD1/BRCA2) or moderate-risk (FANCN/PALB2 and FANCJ/BRIP1) breast cancer susceptibility genes, which makes all members of the FA pathway particularly attractive breast cancer candidate genes. Most FA genes have been screened for mutations in breast cancer families negative for BRCA1/2 mutations but the role of FANCL, FANCM and the recently identified FANCI has not been evaluated to date. This fact and novel data sustaining greater functional relevance of the three genes within the FA pathway prompted us to scrutinize all coding sequences and splicing sites of FANCI, FANCL and FANCM in 95 BRCA1/2-negative index cases from Spanish high-risk breast cancer families. We identified 68 sequence variants of which 24 were coding and 44 non-coding. Six exonic and 26 non-coding variants had not been described previously. None of the coding changes caused clearly pathogenic changes and computational analysis of all non-described intronic variants did not revealed major impact in splicing. With the present study, all known FA genes have been evaluated within the context of breast cancer high-risk predisposition. Our results rule out a major role of FANCI, FANCL and FANCM in familial breast cancer susceptibility, suggesting that among the 13 known FA genes, only FANCD1/BRCA2 plays a major role in high-risk breast cancer predisposition.

  17. Histone chaperone activity of Fanconi anemia proteins, FANCD2 and FANCI, is required for DNA crosslink repair.

    PubMed

    Sato, Koichi; Ishiai, Masamichi; Toda, Kazue; Furukoshi, Satoshi; Osakabe, Akihisa; Tachiwana, Hiroaki; Takizawa, Yoshimasa; Kagawa, Wataru; Kitao, Hiroyuki; Dohmae, Naoshi; Obuse, Chikashi; Kimura, Hiroshi; Takata, Minoru; Kurumizaka, Hitoshi

    2012-08-29

    Fanconi anaemia (FA) is a rare hereditary disorder characterized by genomic instability and cancer susceptibility. A key FA protein, FANCD2, is targeted to chromatin with its partner, FANCI, and plays a critical role in DNA crosslink repair. However, the molecular function of chromatin-bound FANCD2-FANCI is still poorly understood. In the present study, we found that FANCD2 possesses nucleosome-assembly activity in vitro. The mobility of histone H3 was reduced in FANCD2-knockdown cells following treatment with an interstrand DNA crosslinker, mitomycin C. Furthermore, cells harbouring FANCD2 mutations that were defective in nucleosome assembly displayed impaired survival upon cisplatin treatment. Although FANCI by itself lacked nucleosome-assembly activity, it significantly stimulated FANCD2-mediated nucleosome assembly. These observations suggest that FANCD2-FANCI may regulate chromatin dynamics during DNA repair.

  18. Histone chaperone activity of Fanconi anemia proteins, FANCD2 and FANCI, is required for DNA crosslink repair

    PubMed Central

    Sato, Koichi; Ishiai, Masamichi; Toda, Kazue; Furukoshi, Satoshi; Osakabe, Akihisa; Tachiwana, Hiroaki; Takizawa, Yoshimasa; Kagawa, Wataru; Kitao, Hiroyuki; Dohmae, Naoshi; Obuse, Chikashi; Kimura, Hiroshi; Takata, Minoru; Kurumizaka, Hitoshi

    2012-01-01

    Fanconi anaemia (FA) is a rare hereditary disorder characterized by genomic instability and cancer susceptibility. A key FA protein, FANCD2, is targeted to chromatin with its partner, FANCI, and plays a critical role in DNA crosslink repair. However, the molecular function of chromatin-bound FANCD2-FANCI is still poorly understood. In the present study, we found that FANCD2 possesses nucleosome-assembly activity in vitro. The mobility of histone H3 was reduced in FANCD2-knockdown cells following treatment with an interstrand DNA crosslinker, mitomycin C. Furthermore, cells harbouring FANCD2 mutations that were defective in nucleosome assembly displayed impaired survival upon cisplatin treatment. Although FANCI by itself lacked nucleosome-assembly activity, it significantly stimulated FANCD2-mediated nucleosome assembly. These observations suggest that FANCD2-FANCI may regulate chromatin dynamics during DNA repair. PMID:22828868

  19. Fanconi anemia group J mutation abolishes its DNA repair function by uncoupling DNA translocation from helicase activity or disruption of protein-DNA complexes

    PubMed Central

    Wu, Yuliang; Sommers, Joshua A.; Suhasini, Avvaru N.; Leonard, Thomas; Deakyne, Julianna S.; Mazin, Alexander V.; Shin-ya, Kazuo; Kitao, Hiroyuki

    2010-01-01

    Fanconi anemia (FA) is a genetic disease characterized by congenital abnormalities, bone marrow failure, and susceptibility to leukemia and other cancers. FANCJ, one of 13 genes linked to FA, encodes a DNA helicase proposed to operate in homologous recombination repair and replicational stress response. The pathogenic FANCJ-A349P amino acid substitution resides immediately adjacent to a highly conserved cysteine of the iron-sulfur domain. Given the genetic linkage of the FANCJ-A349P allele to FA, we investigated the effect of this particular mutation on the biochemical and cellular functions of the FANCJ protein. Purified recombinant FANCJ-A349P protein had reduced iron and was defective in coupling adenosine triphosphate (ATP) hydrolysis and translocase activity to unwinding forked duplex or G-quadruplex DNA substrates or disrupting protein-DNA complexes. The FANCJ-A349P allele failed to rescue cisplatin or telomestatin sensitivity of a FA-J null cell line as detected by cell survival or γ-H2AX foci formation. Furthermore, expression of FANCJ-A349P in a wild-type background exerted a dominant-negative effect, indicating that the mutant protein interferes with normal DNA metabolism. The ability of FANCJ to use the energy from ATP hydrolysis to produce the force required to unwind DNA or destabilize protein bound to DNA is required for its role in DNA repair. PMID:20639400

  20. Factors Influencing the Decision-Making Process and Long-Term Interpersonal Outcomes for Parents Who Undergo Preimplantation Genetic Diagnosis for Fanconi Anemia: a Qualitative Investigation.

    PubMed

    Haude, K; McCarthy Veach, P; LeRoy, B; Zierhut, H

    2017-06-01

    Fanconi anemia (FA) is characterized by congenital malformations, progressive bone marrow failure, and predisposition to malignancy. Hematopoietic stem cell transplantation is used to treat FA, and best results are attained with sibling donors who are human leukocyte antigen (HLA) identical matches. Preimplantation genetic diagnosis (PGD) offers parents of an affected child the opportunity to have an unaffected child who is an HLA match. While some research has investigated parents' experiences during the PGD process, no published studies specifically address factors influencing their decision-making process and long-term interpersonal outcomes. The aims of this study are to: (1) examine parents' expectations and the influence of media, bioethics, and religion on their decision to undergo PGD; (2) examine parents' social support and emotional experiences during their PGD process; and (3) characterize long-term effects of PGD on relationship dynamics (partner, family, friends), others' attitudes, and parental regret. Nine parents participated in semi-structured interviews. Thematic analysis revealed their decision to use PGD was variously influenced by media, bioethics, and religion, in particular, affecting parents' initial confidence levels. Moreover, the PGD process was emotionally complex, with parents desiring varying amounts and types of support from different sources at different times. Parents reported others' attitudes towards them were similar or no different than before PGD. Parental regret regarding PGD was negligible. Results of this study will promote optimization of long-term care for FA families.

  1. Hyper-active non-homologous end joining selects for synthetic lethality resistant and pathological Fanconi anemia hematopoietic stem and progenitor cells

    PubMed Central

    Du, Wei; Amarachintha, Surya; Wilson, Andrew F.; Pang, Qishen

    2016-01-01

    The prominent role of Fanconi anemia (FA) proteins involves homologous recombination (HR) repair. Poly[ADP-ribose] polymerase1 (PARP1) functions in multiple cellular processes including DNA repair and PARP inhibition is an emerging targeted therapy for cancer patients deficient in HR. Here we show that PARP1 activation in hematopoietic stem and progenitor cells (HSPCs) in response to genotoxic or oxidative stress attenuates HSPC exhaustion. Mechanistically, PARP1 controls the balance between HR and non-homologous end joining (NHEJ) in double strand break (DSB) repair by preventing excessive NHEJ. Disruption of the FA core complex skews PARP1 function in DSB repair and led to hyper-active NHEJ in Fanca−/− or Fancc−/− HSPCs. Re-expression of PARP1 rescues the hyper-active NHEJ phenotype in Brca1−/−Parp1−/− but less effective in Fanca−/−Parp1−/− cells. Inhibition of NHEJ prevents myeloid/erythroid pathologies associated with synthetic lethality. Our results suggest that hyper-active NHEJ may select for “synthetic lethality” resistant and pathological HSPCs. PMID:26916217

  2. The Fanconi Anemia DNA Repair Pathway Is Regulated by an Interaction between Ubiquitin and the E2-like Fold Domain of FANCL.

    PubMed

    Miles, Jennifer A; Frost, Mark G; Carroll, Eilis; Rowe, Michelle L; Howard, Mark J; Sidhu, Ateesh; Chaugule, Viduth K; Alpi, Arno F; Walden, Helen

    2015-08-21

    The Fanconi Anemia (FA) DNA repair pathway is essential for the recognition and repair of DNA interstrand crosslinks (ICL). Inefficient repair of these ICL can lead to leukemia and bone marrow failure. A critical step in the pathway is the monoubiquitination of FANCD2 by the RING E3 ligase FANCL. FANCL comprises 3 domains, a RING domain that interacts with E2 conjugating enzymes, a central domain required for substrate interaction, and an N-terminal E2-like fold (ELF) domain. The ELF domain is found in all FANCL homologues, yet the function of the domain remains unknown. We report here that the ELF domain of FANCL is required to mediate a non-covalent interaction between FANCL and ubiquitin. The interaction involves the canonical Ile44 patch on ubiquitin, and a functionally conserved patch on FANCL. We show that the interaction is not necessary for the recognition of the core complex, it does not enhance the interaction between FANCL and Ube2T, and is not required for FANCD2 monoubiquitination in vitro. However, we demonstrate that the ELF domain is required to promote efficient DNA damage-induced FANCD2 monoubiquitination in vertebrate cells, suggesting an important function of ubiquitin binding by FANCL in vivo.

  3. Mutation in the COX4I1 gene is associated with short stature, poor weight gain and increased chromosomal breaks, simulating Fanconi anemia.

    PubMed

    Abu-Libdeh, Bassam; Douiev, Liza; Amro, Sarah; Shahrour, Maher; Ta-Shma, Asaf; Miller, Chaya; Elpeleg, Orly; Saada, Ann

    2017-10-01

    We describe a novel autosomal recessive form of mitochondrial disease in a child with short stature, poor weight gain, and mild dysmorphic features with highly suspected Fanconi anemia due to a mutation in COX4I1 gene. Whole Exome Sequencing was performed then followed by Sanger confirmation, identified a K101N mutation in COX4I1, segregating with the disease. This nuclear gene encodes the common isoform of cytochrome c oxidase (COX) subunit 4 (COX 4-1), an integral regulatory part of COX (respiratory chain complex IV) the terminal electron acceptor of the mitochondrial respiratory chain. The patient's fibroblasts disclosed decreased COX activity, impaired ATP production, elevated ROS production, decreased expression of COX4I1 mRNA and undetectable (COX4) protein. COX activity and ATP production were restored by lentiviral transfection with the wild-type gene. Our results demonstrate the first human mutation in the COX4I1 gene linked to diseases and confirm its role in the pathogenesis. Thus COX4I1 mutations should be considered in any patient with features suggestive of this diagnosis.

  4. Defects in the Fanconi Anemia Pathway in Head and Neck Cancer Cells Stimulate Tumor Cell Invasion through DNA-PK and Rac1 Signaling.

    PubMed

    Romick-Rosendale, Lindsey E; Hoskins, Elizabeth E; Privette Vinnedge, Lisa M; Foglesong, Grant D; Brusadelli, Marion G; Potter, S Steven; Komurov, Kakajan; Brugmann, Samantha A; Lambert, Paul F; Kimple, Randall J; Virts, Elizabeth L; Hanenberg, Helmut; Gillison, Maura L; Wells, Susanne I

    2016-04-15

    Head and neck squamous cell carcinoma (HNSCC) remains a devastating disease, and Fanconi anemia (FA) gene mutations and transcriptional repression are common. Invasive tumor behavior is associated with poor outcome, but relevant pathways triggering invasion are poorly understood. There is a significant need to improve our understanding of genetic pathways and molecular mechanisms driving advanced tumor phenotypes, to develop tailored therapies. Here we sought to investigate the phenotypic and molecular consequences of FA pathway loss in HNSCC cells. Using sporadic HNSCC cell lines with and without FA gene knockdown, we sought to characterize the phenotypic and molecular consequences of FA deficiency. FA pathway inactivation was confirmed by the detection of classic hallmarks of FA following exposure to DNA cross-linkers. Cells were subjected to RNA sequencing with qRT-PCR validation, followed by cellular adhesion and invasion assays in the presence and absence of DNA-dependent protein kinase (DNA-PK) and Rac1 inhibitors. We demonstrate that FA loss in HNSCC cells leads to cytoskeletal reorganization and invasive tumor cell behavior in the absence of proliferative gains. We further demonstrate that cellular invasion following FA loss is mediated, at least in part, through NHEJ-associated DNA-PK and downstream Rac1 GTPase activity. These findings demonstrate that FA loss stimulates HNSCC cell motility and invasion, and implicate a targetable DNA-PK/Rac1 signaling axis in advanced tumor phenotypes. ©2015 American Association for Cancer Research.

  5. The Fanconi anemia/BRCA pathway is involved in DNA interstrand cross-link repair of adriamycin-resistant leukemia cells.

    PubMed

    Yao, Chenjiao; Du, Wei; Chen, Haibing; Xiao, Sheng; Huang, Lihua; Chen, Fangping

    2015-03-01

    The Fanconi anemia/BRCA (FA/BRCA) pathway plays a vital role in DNA damage repair induced by DNA cross-linking agents and is closely related to drug response in cancer treatment. Here we demonstrate that the FA/BRCA pathway contributes to acquired drug resistance in adriamycin (ADR)-resistant leukemia cell lines, and disruption of this pathway partially reverses the drug resistance. We observed that ADR-resistant cells have reduced DNA interstrand cross-links (ICL) compared with ADR-sensitive cells. Western blot studies demonstrated enhanced FA protein expression in ADR-resistant cells. Using siRNA to knock down FANCF in K562/R drug-resistant cells showed increases in sensitivity to ADR and ADR-induced DNA damage, and demonstrated a direct relationship between the FA/BRCA pathway and drug sensitivity. Overexpression of FANCF in K562 drug-sensitive cells partially reproduced the drug-resistant phenotype. These results show that the FA/BRCA pathway is involved in acquired ADR resistance of leukemia cells. The FA/BRCA pathway may be a new target to reverse ADR resistance in leukemia treatment.

  6. Crystal structure of a Fanconi anemia-associated nuclease homolog bound to 5' flap DNA: basis of interstrand cross-link repair by FAN1

    SciTech Connect

    Gwon, Gwang Hyeon; Kim, Youngran; Liu, Yaqi; Watson, Adam T.; Jo, Aera; Etheridge, Thomas J.; Yuan, Fenghua; Zhang, Yanbin; Kim, YoungChang; Carr, Anthony M.; Cho, Yunje

    2014-10-15

    Fanconi anemia (FA) is an autosomal recessive genetic disorder caused by defects in any of 15 FA genes responsible for processing DNA interstrand cross-links (ICLs). The ultimate outcome of the FA pathway is resolution of cross-links, which requires structure-selective nucleases. FA-associated nuclease 1 (FAN1) is believed to be recruited to lesions by a monoubiquitinated FANCI–FANCD2 (ID) complex and participates in ICL repair. Here, we determined the crystal structure of Pseudomonas aeruginosa FAN1 (PaFAN1) lacking the UBZ (ubiquitin-binding zinc) domain in complex with 5' flap DNA. All four domains of the right-hand-shaped PaFAN1 are involved in DNA recognition, with each domain playing a specific role in bending DNA at the nick. The six-helix bundle that binds the junction connects to the catalytic viral replication and repair (VRR) nuclease (VRR nuc) domain, enabling FAN1 to incise the scissile phosphate a few bases distant from the junction. The six-helix bundle also inhibits the cleavage of intact Holliday junctions. PaFAN1 shares several conserved features with other flap structure-selective nucleases despite structural differences. A clamping motion of the domains around the wedge helix, which acts as a pivot, facilitates nucleolytic cleavage. The PaFAN1 structure provides insights into how archaeal Holliday junction resolvases evolved to incise 5' flap substrates and how FAN1 integrates with the FA complex to participate in ICL repair.

  7. Mouth self-examination as a screening tool for oral cancer in a high-risk group of patients with Fanconi anemia.

    PubMed

    Furquim, Camila Pinheiro; Pivovar, Allana; Cavalcanti, Laura Grein; Araújo, Renata Fuentes; Sales Bonfim, Carmem Maria; Torres-Pereira, Cassius Carvalho

    2014-10-01

    Oral cancer usually occurs at accessible sites, enabling early detection by visual inspection. Fanconi anemia (FA) is a recessive disorder associated with a high risk of developing head and neck solid tumors. The aim of this study was to assess the ability to perform mouth self-examination (MSE) in these patients. A total of 44 patients with FA, aged ≥ 18 years, were given a self-reported questionnaire to collect sociodemographic data and information about health-related behaviors and oral cancer awareness. They were asked to perform MSE, which was evaluated using criteria for mucosal visualization and retracting ability. Subsequently, an oral medicine specialist clinically examined all participants, and these findings were considered to be the gold standard. The sensitivity and specificity values of MSE were 43% and 44%, respectively. The MSE accuracy was 43%. Most patients (73%) reported that MSE was easy or very easy, although 75% showed insufficient performance. The accuracy of MSE alone is not sufficient to indicate whether MSE should be recommended as a strategy to prevent oral cancer in patients with FA. Nevertheless, the present results indicate that this inexpensive technique could be used as a tool for early detection of cancer in these patients. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. The nuclease hSNM1B/Apollo is linked to the Fanconi anemia pathway via its interaction with FANCP/SLX4.

    PubMed

    Salewsky, Bastian; Schmiester, Maren; Schindler, Detlev; Digweed, Martin; Demuth, Ilja

    2012-11-15

    The recessive genetic disorder Fanconi anemia (FA) is clinically characterized by congenital defects, bone marrow failure and an increased incidence of cancer. Cells derived from FA patients exhibit hypersensitivity to DNA interstrand crosslink (ICL)-inducing agents. We have earlier reported a similar cellular phenotype for human cells depleted of hSNM1B/Apollo (siRNA). In fact, hSNM1B/Apollo has a dual role in the DNA damage response and in generation and maintenance of telomeres, the latter function involving interaction with the shelterin protein TRF2. Here we find that ectopically expressed hSNM1B/Apollo co-immunoprecipitates with SLX4, a protein recently identified as a new FA protein, FANCP, and known to interact with several structure-specific nucleases. As shown by immunofluorescence analysis, FANCP/SLX4 depletion (siRNA) resulted in a significant reduction of hSNM1B/Apollo nuclear foci, supporting the functional relevance of this new protein interaction. Interestingly, as an additional consequence of FANCP/SLX4 depletion, we found a reduction of cellular TRF2, in line with its telomere-related function. Finally, analysis of human cells following double knockdown of hSNM1B/Apollo and FANCP/SLX4 indicated that they function epistatically. These findings further substantiate the role of hSNM1B/Apollo in a downstream step of the FA pathway during the repair of DNA ICLs.

  9. The carboxyl terminus of FANCE recruits FANCD2 to the Fanconi Anemia (FA) E3 ligase complex to promote the FA DNA repair pathway.

    PubMed

    Polito, David; Cukras, Scott; Wang, Xiaozhe; Spence, Paige; Moreau, Lisa; D'Andrea, Alan D; Kee, Younghoon

    2014-03-07

    Fanconi anemia (FA) is a genome instability syndrome characterized by bone marrow failure and cellular hypersensitivity to DNA cross-linking agents. In response to DNA damage, the FA pathway is activated through the cooperation of 16 FA proteins. A central player in the pathway is a multisubunit E3 ubiquitin ligase complex or the FA core complex, which monoubiquitinates its substrates FANCD2 and FANCI. FANCE, a subunit of the FA core complex, plays an essential role by promoting the integrity of the complex and by directly recognizing FANCD2. To delineate its role in substrate ubiquitination from the core complex assembly, we analyzed a series of mutations within FANCE. We report that a phenylalanine located at the highly conserved extreme C terminus, referred to as Phe-522, is a critical residue for mediating the monoubiquitination of the FANCD2-FANCI complex. Using the FANCE mutant that specifically disrupts the FANCE-FANCD2 interaction as a tool, we found that the interaction-deficient mutant conferred cellular sensitivity in reconstituted FANCE-deficient cells to a similar degree as FANCE null cells, suggesting the significance of the FANCE-FANCD2 interaction in promoting cisplatin resistance. Intriguingly, ectopic expression of the FANCE C terminus fragment alone in FA normal cells disrupts DNA repair, consolidating the importance of the FANCE-FANCD2 interaction in the DNA cross-link repair.

  10. HPV-16 E7 reveals a link between DNA replication stress, fanconi anemia D2 protein, and alternative lengthening of telomere-associated promyelocytic leukemia bodies.

    PubMed

    Spardy, Nicole; Duensing, Anette; Hoskins, Elizabeth E; Wells, Susanne I; Duensing, Stefan

    2008-12-01

    Expression of the high-risk human papillomavirus (HPV-16) E7 oncoprotein extends the life span of primary human keratinocytes and partially restores telomere length in the absence of telomerase. The molecular basis of this activity is incompletely understood. Here, we show that HPV-16 E7 induces an increased formation of alternative lengthening of telomeres (ALT)-associated promyelocytic leukemia bodies (APBs) in early passage primary human keratinocytes as well as HPV-negative tumor cells. This activity was found to require sequences of HPV-16 E7 involved in degradation of the retinoblastoma tumor suppressor protein as well as regions in the COOH terminus. HPV-16 E7-induced APBs contained ssDNA and several proteins that are involved in the response to DNA replication stress, most notably the Fanconi anemia D2 protein (FANCD2) as well as BRCA2 and MUS81. In line with these results, we found that FANCD2-containing APBs form in an ATR-dependent manner in HPV-16 E7-expressing cells. To directly show a role of FANCD2 in ALT, we provide evidence that knockdown of FANCD2 rapidly causes telomere dysfunction in cells that rely on ALT to maintain telomeres. Taken together, our results suggest a novel link between replication stress and recombination-based telomere maintenance that may play a role in HPV-16 E7-mediated extension of host cell life span and immortalization.

  11. Functional interaction between the Fanconi Anemia D2 protein and proliferating cell nuclear antigen (PCNA) via a conserved putative PCNA interaction motif.

    PubMed

    Howlett, Niall G; Harney, Julie A; Rego, Meghan A; Kolling, Frederick W; Glover, Thomas W

    2009-10-16

    Fanconi Anemia (FA) is a rare recessive disease characterized by congenital abnormalities, bone marrow failure, and cancer susceptibility. The FA proteins and the familial breast cancer susceptibility gene products, BRCA1 and FANCD1/BRCA2, function cooperatively in the FA-BRCA pathway to repair damaged DNA and to prevent cellular transformation. Activation of this pathway occurs via the mono-ubiquitination of the FANCD2 protein, targeting it to nuclear foci where it co-localizes with FANCD1/BRCA2, RAD51, and PCNA. The regulation of the mono-ubiquitination of FANCD2, as well as its function in DNA repair remain poorly understood. In this study, we have further characterized the interaction between the FANCD2 and PCNA proteins. We have identified a highly conserved, putative FANCD2 PCNA interaction motif (PIP-box), and demonstrate that mutation of this motif disrupts FANCD2-PCNA binding and precludes the mono-ubiquitination of FANCD2. Consequently, the FANCD2 PIP-box mutant protein fails to correct the mitomycin C hypersensitivity of FA-D2 patient cells. Our results suggest that PCNA may function as a molecular platform to facilitate the mono-ubiquitination of FANCD2 and activation of the FA-BRCA pathway.

  12. UBE2T, the Fanconi anemia core complex, and FANCD2 are recruited independently to chromatin: a basis for the regulation of FANCD2 monoubiquitination.

    PubMed

    Alpi, Arno; Langevin, Frederic; Mosedale, Georgina; Machida, Yuichi J; Dutta, Anindya; Patel, Ketan J

    2007-12-01

    The Fanconi anemia (FA) nuclear core complex and the E2 ubiquitin-conjugating enzyme UBE2T are required for the S phase and DNA damage-restricted monoubiquitination of FANCD2. This constitutes a key step in the FA tumor suppressor pathway, and much attention has been focused on the regulation at this point. Here, we address the importance of the assembly of the FA core complex and the subcellular localization of UBE2T in the regulation of FANCD2 monoubiquitination. We establish three points. First, the stable assembly of the FA core complex can be dissociated of its ability to function as an E3 ubiquitin ligase. Second, the actual E3 ligase activity is not determined by the assembly of the FA core complex but rather by its DNA damage-induced localization to chromatin. Finally, UBE2T and FANCD2 access this subcellular fraction independently of the FA core complex. FANCD2 monoubiquitination is therefore not regulated by multiprotein complex assembly but by the formation of an active E2/E3 holoenzyme on chromatin.

  13. FANCC, FANCE, and FANCD2 form a ternary complex essential to the integrity of the Fanconi anemia DNA damage response pathway.

    PubMed

    Gordon, Susan M; Alon, Noa; Buchwald, Manuel

    2005-10-28

    Fanconi anemia (FA) is a genetically heterogeneous disorder characterized by bone marrow failure, cancer predisposition, and increased cellular sensitivity to DNA-cross-linking agents. The products of seven of the nine identified FA genes participate in a protein complex required for monoubiquitination of the FANCD2 protein. Direct interaction of the FANCE protein with both fellow FA complex component FANCC and the downstream FANCD2 protein has been observed in the yeast two-hybrid system. Here, we demonstrate the ability of FANCE to mediate the interaction between FANCC and FANCD2 in the yeast three-hybrid system and confirm the FANCE-mediated association of FANCC with FANCD2 in human cells. A yeast two-hybrid system-based screen was devised to identify randomly mutagenized FANCE proteins capable of interaction with FANCC but not with FANCD2. Exogenous expression of these mutants in an FA-E cell line and subsequent evaluation of FANCD2 monoubiquitination and DNA cross-linker sensitivity indicated a critical role for the FANCE/FANCD2 interaction in maintaining FA pathway integrity. Three-hybrid experiments also demonstrated the ability of FANCE to mediate the interaction between FA core complex components FANCC and FANCF, indicating an additional role for FANCE in complex assembly. Thus, FANCE is shown to be a key mediator of protein interactions both in the architecture of the FA protein complex and in the connection of complex components to the putative downstream targets of complex activity.

  14. ΔNp63 activates the Fanconi anemia DNA repair pathway and limits the efficacy of cisplatin treatment in squamous cell carcinoma.

    PubMed

    Bretz, Anne Catherine; Gittler, Miriam P; Charles, Joël P; Gremke, Niklas; Eckhardt, Ines; Mernberger, Marco; Mandic, Robert; Thomale, Jürgen; Nist, Andrea; Wanzel, Michael; Stiewe, Thorsten

    2016-04-20

    TP63, a member of the p53 gene family gene, encodes the ΔNp63 protein and is one of the most frequently amplified genes in squamous cell carcinomas (SCC) of the head and neck (HNSCC) and lungs (LUSC). Using an epiallelic series of siRNAs with intrinsically different knockdown abilities, we show that the complete loss of ΔNp63 strongly impaired cell proliferation, whereas partial ΔNp63 depletion rendered cells hypersensitive to cisplatin accompanied by an accumulation of DNA damage. Expression profiling revealed wide-spread transcriptional regulation of DNA repair genes and in particular Fanconi anemia (FA) pathway components such as FANCD2 and RAD18 - known to be crucial for the repair of cisplatin-induced interstrand crosslinks. In SCC patients ΔNp63 levels significantly correlate with FANCD2 and RAD18 expression confirming ΔNp63 as a key activator of the FA pathway in vivo Mechanistically, ΔNp63 bound an upstream enhancer of FANCD2 inactive in primary keratinocytes but aberrantly activated by ΔNp63 in SCC. Consistently, depletion of FANCD2 sensitized to cisplatin similar to depletion of ΔNp63. Together, our results demonstrate that ΔNp63 directly activates the FA pathway in SCC and limits the efficacy of cisplatin treatment. Targeting ΔNp63 therefore would not only inhibit SCC proliferation but also sensitize tumors to chemotherapy.

  15. The Fanconi anemia pathway controls oncogenic response in hematopoietic stem and progenitor cells by regulating PRMT5-mediated p53 arginine methylation

    PubMed Central

    Du, Wei; Amarachintha, Surya; Erden, Ozlem; Wilson, Andrew; Pang, Qishen

    2016-01-01

    The Fanconi anemia (FA) pathway is involved in DNA damage and other cellular stress responses. We have investigated the role of the FA pathway in oncogenic stress response by employing an in vivo stress-response model expressing the Gadd45β-luciferase transgene. Using two inducible models of oncogenic activation (LSL-K-rasG12D and MycER), we show that hematopoietic stem and progenitor cells (HSPCs) from mice deficient for the FA core complex components Fanca or Fancc exhibit aberrant short-lived response to oncogenic insults. Mechanistic studies reveal that FA deficiency in HSPCs impairs oncogenic stress-induced G1 cell-cycle checkpoint, resulting from a compromised K-rasG12D-induced arginine methylation of p53 mediated by the protein arginine methyltransferase 5 (PRMT5). Furthermore, forced expression of PRMT5 in HSPCs from LSL-K-rasG12D/CreER-Fanca−/− mice prolongs oncogenic response and delays leukemia development in recipient mice. Our study defines an arginine methylation-dependent FA-p53 interplay that controls oncogenic stress response. PMID:27507053

  16. ΔNp63 activates the Fanconi anemia DNA repair pathway and limits the efficacy of cisplatin treatment in squamous cell carcinoma

    PubMed Central

    Bretz, Anne Catherine; Gittler, Miriam P.; Charles, Joël P.; Gremke, Niklas; Eckhardt, Ines; Mernberger, Marco; Mandic, Robert; Thomale, Jürgen; Nist, Andrea; Wanzel, Michael; Stiewe, Thorsten

    2016-01-01

    TP63, a member of the p53 gene family gene, encodes the ΔNp63 protein and is one of the most frequently amplified genes in squamous cell carcinomas (SCC) of the head and neck (HNSCC) and lungs (LUSC). Using an epiallelic series of siRNAs with intrinsically different knockdown abilities, we show that the complete loss of ΔNp63 strongly impaired cell proliferation, whereas partial ΔNp63 depletion rendered cells hypersensitive to cisplatin accompanied by an accumulation of DNA damage. Expression profiling revealed wide-spread transcriptional regulation of DNA repair genes and in particular Fanconi anemia (FA) pathway components such as FANCD2 and RAD18 - known to be crucial for the repair of cisplatin-induced interstrand crosslinks. In SCC patients ΔNp63 levels significantly correlate with FANCD2 and RAD18 expression confirming ΔNp63 as a key activator of the FA pathway in vivo. Mechanistically, ΔNp63 bound an upstream enhancer of FANCD2 inactive in primary keratinocytes but aberrantly activated by ΔNp63 in SCC. Consistently, depletion of FANCD2 sensitized to cisplatin similar to depletion of ΔNp63. Together, our results demonstrate that ΔNp63 directly activates the FA pathway in SCC and limits the efficacy of cisplatin treatment. Targeting ΔNp63 therefore would not only inhibit SCC proliferation but also sensitize tumors to chemotherapy. PMID:26819410

  17. The Carboxyl Terminus of FANCE Recruits FANCD2 to the Fanconi Anemia (FA) E3 Ligase Complex to Promote the FA DNA Repair Pathway*

    PubMed Central

    Polito, David; Cukras, Scott; Wang, Xiaozhe; Spence, Paige; Moreau, Lisa; D'Andrea, Alan D.; Kee, Younghoon

    2014-01-01

    Fanconi anemia (FA) is a genome instability syndrome characterized by bone marrow failure and cellular hypersensitivity to DNA cross-linking agents. In response to DNA damage, the FA pathway is activated through the cooperation of 16 FA proteins. A central player in the pathway is a multisubunit E3 ubiquitin ligase complex or the FA core complex, which monoubiquitinates its substrates FANCD2 and FANCI. FANCE, a subunit of the FA core complex, plays an essential role by promoting the integrity of the complex and by directly recognizing FANCD2. To delineate its role in substrate ubiquitination from the core complex assembly, we analyzed a series of mutations within FANCE. We report that a phenylalanine located at the highly conserved extreme C terminus, referred to as Phe-522, is a critical residue for mediating the monoubiquitination of the FANCD2-FANCI complex. Using the FANCE mutant that specifically disrupts the FANCE-FANCD2 interaction as a tool, we found that the interaction-deficient mutant conferred cellular sensitivity in reconstituted FANCE-deficient cells to a similar degree as FANCE null cells, suggesting the significance of the FANCE-FANCD2 interaction in promoting cisplatin resistance. Intriguingly, ectopic expression of the FANCE C terminus fragment alone in FA normal cells disrupts DNA repair, consolidating the importance of the FANCE-FANCD2 interaction in the DNA cross-link repair. PMID:24451376

  18. RNA interferences targeting the Fanconi anemia/BRCA pathway upstream genes reverse cisplatin resistance in drug-resistant lung cancer cells.

    PubMed

    Dai, Chun-Hua; Li, Jian; Chen, Ping; Jiang, He-Guo; Wu, Ming; Chen, Yong-Chang

    2015-09-18

    Cisplatin is one of the most commonly used chemotherapy agent for lung cancer. The therapeutic efficacy of cisplatin is limited by the development of resistance. In this study, we test the effect of RNA interference (RNAi) targeting Fanconi anemia (FA)/BRCA pathway upstream genes on the sensitivity of cisplatin-sensitive (A549 and SK-MES-1) and -resistant (A549/DDP) lung cancer cells to cisplatin. Using small interfering RNA (siRNA), knockdown of FANCF, FANCL, or FANCD2 inhibited function of the FA/BRCA pathway in A549, A549/DDP and SK-MES-1 cells, and potentiated sensitivity of the three cells to cisplatin. The extent of proliferation inhibition induced by cisplatin after knockdown of FANCF and/or FANCL in A549/DDP cells was significantly greater than in A549 and SK-MES-1 cells, suggesting that depletion of FANCF and/or FANCL can reverse resistance of cisplatin-resistant lung cancer cells to cisplatin. Furthermore, knockdown of FANCL resulted in higher cisplatin sensitivity and dramatically elevated apoptosis rates compared with knockdown of FANCF in A549/DDP cells, indicating that FANCL play an important role in the repair of cisplatin-induced DNA damage. Knockdown of FANCF, FANCL, or FANCD2 by RNAi could synergize the effect of cisplatin on suppressing cell proliferation in cisplatin-resistant lung cancer cells through inhibition of FA/BRCA pathway.

  19. Favourable long-term outcome after matched sibling transplantation for Fanconi-anemia (FA) and in vivo T-cell depletion.

    PubMed

    Huck, K; Hanenberg, H; Nürnberger, W; Dilloo, D; Burdach, S; Göbel, U; Laws, H J

    2008-01-01

    Hematopoietic stem cell transplantation is the only permanent treatment for the hematological manifestations in Fanconi anemia (FA). As FA patients have a dramatically increased intrinsic propensity to develop malignancies later in life and the genotoxic stress afflicted during conditioning advances the manifestation age especially of squamous cell carcinomas, choosing an optimally suited treatment regimen appears critical for long-term, tumor-free survival after stem cell transplantation. Here, we report our experiences in 6 consecutive FA patients transplanted with HLA-matched sibling donors where we combined an established pre-transplantation treatment consisting of thoraco-abdominal irradiation (TAI), cyclophosphamide (CYC) and cyclosporine A graft-versus-host prophylaxis with antibody-mediated IN VIVO T-cell depletion strategies after infusion of the graft. This approach has ensured sustained engraftment with long-term survival and an excellent post transplant performance status without any evidence of secondary malignancies in all six patients after a median follow-up of more than 10 years.

  20. Hyper-active non-homologous end joining selects for synthetic lethality resistant and pathological Fanconi anemia hematopoietic stem and progenitor cells.

    PubMed

    Du, Wei; Amarachintha, Surya; Wilson, Andrew F; Pang, Qishen

    2016-02-26

    The prominent role of Fanconi anemia (FA) proteins involves homologous recombination (HR) repair. Poly[ADP-ribose] polymerase1 (PARP1) functions in multiple cellular processes including DNA repair and PARP inhibition is an emerging targeted therapy for cancer patients deficient in HR. Here we show that PARP1 activation in hematopoietic stem and progenitor cells (HSPCs) in response to genotoxic or oxidative stress attenuates HSPC exhaustion. Mechanistically, PARP1 controls the balance between HR and non-homologous end joining (NHEJ) in double strand break (DSB) repair by preventing excessive NHEJ. Disruption of the FA core complex skews PARP1 function in DSB repair and led to hyper-active NHEJ in Fanca(-/-) or Fancc(-/-) HSPCs. Re-expression of PARP1 rescues the hyper-active NHEJ phenotype in Brca1(-/-)Parp1(-/-) but less effective in Fanca(-/-)Parp1(-/-) cells. Inhibition of NHEJ prevents myeloid/erythroid pathologies associated with synthetic lethality. Our results suggest that hyper-active NHEJ may select for "synthetic lethality" resistant and pathological HSPCs.

  1. Risk of head and neck squamous cell cancer and death in patients with Fanconi anemia who did and did not receive transplants.

    PubMed

    Rosenberg, Philip S; Socié, Gerard; Alter, Blanche P; Gluckman, Eliane

    2005-01-01

    Hematopoietic stem cell transplant (SCT) is currently the only therapy that can restore normal hematopoiesis in patients with Fanconi anemia (FA). Patients with FA have a high baseline risk of squamous cell cancers (SCCs) of the head, neck, and esophagus, and SCT conditioning may increase SCC incidence. We evaluated the risks of SCC and death in 145 patients with FA in the North American Survey (NAS) cohort who did not receive transplants, and 117 patients with FA in the Hôpital Saint Louis (SLH) cohort who did receive transplants. The age-specific hazard of SCC was 4.4-fold higher in patients who received transplants than in those who did not (P = .003), and SCCs occurred at significantly younger ages in the former (respective medians, 18 and 33 years, P = .004). Survival after SCC was similarly poor in both cohorts (P = .135, median, 13 months). The hazard of SCC increased at a greater than linear rate, to 4.4% per year by age 40 in NAS and 4.7% per year by 10 years after transplant in SLH. In SLH, the hazard of non-SCC death was biphasic, declining significantly (P = .004) from 7.1% per month during the first 6 months after transplant to 0.13% per month (1.6% per year) after the first year. Acute and chronic graft-versus-host diseases were significant SCC risk factors. Adverse event rates in these cohorts provide historical control rates to assess emerging therapies for FA.

  2. Monoubiquitinated Fanconi anemia D2 (FANCD2-Ub) is required for BCR-ABL1 kinase-induced leukemogenesis.

    PubMed

    Koptyra, M; Stoklosa, T; Hoser, G; Glodkowska-Mrowka, E; Seferynska, I; Klejman, A; Blasiak, J; Skorski, T

    2011-08-01

    Fanconi D2 (FANCD2) is monoubiquitinated on K561 (FANCD2-Ub) in response to DNA double-strand breaks (DSBs) to stimulate repair of these potentially lethal DNA lesions. FANCD2-Ub was upregulated in CD34+ chronic myeloid leukemia (CML) cells and in BCR-ABL1 kinase-positive cell lines in response to elevated levels of reactive oxygen species (ROS) and DNA cross-linking agent mitomycin C. Downregulation of FANCD2 and inhibition of FANCD2-Ub reduced the clonogenic potential of CD34+ CML cells and delayed BCR-ABL1 leukemogenesis in mice. Retarded proliferation of BCR-ABL1 positive FANCD2-/- leukemia cells could be rescued by FANCD2 expression. BCR-ABL1 positive FANCD2-/- cells accumulated more ROS-induced DSBs in comparison with BCR-ABL1 positive FANCD2+/+ cells. Antioxidants diminished the number of DSBs and enhanced proliferation of BCR-ABL1 positive FANCD2-/- cells. Expression of wild-type FANCD2 and FANCD2(S222A) phosphorylation-defective mutant (deficient in stimulation of intra-S phase checkpoint, but proficient in DSB repair), but not FANCD2(K561R) monoubiquitination-defective mutant (proficient in stimulation of intra-S phase checkpoint, but deficient in DSB repair) reduced the number of DSBs and facilitated proliferation of BCR-ABL1 positive FANCD2-/- cells. We hypothesize that FANCD2-Ub has an important role in BCR-ABL1 leukemogenesis because of its ability to facilitate the repair of numerous ROS-induced DSBs.

  3. Monoubiquitinated Fanconi Anemia D2 (FANCD2-Ub) Is Required for BCR-ABL1 Kinase -Induced Leukemogenesis

    PubMed Central

    Koptyra, Mateusz; Stoklosa, Tomasz; Hoser, Grazyna; Glodkowska-Mrowka, Eliza; Seferynska, Ilona; Klejman, Agata; Blasiak, Janusz; Skorski, Tomasz

    2011-01-01

    Fanconi D2 (FANCD2) is monoubiquitinated on K561 (FANCD2-Ub) in response to DNA double-strand breaks (DSBs) to stimulate repair of these potentially lethal DNA lesions. FANCD2-Ub was upregulated in CD34+ chronic myeloid leukemia (CML) cells and in BCR-ABL1 kinase –positive cell lines in response to elevated levels of reactive oxygen species (ROS) and DNA cross-linking agent mitomycin C. Downregulation of FANCD2 and inhibition of FANCD2-Ub reduced the clonogenic potential of CD34+ CML cells and delayed BCR-ABL1 leukemogenesis in mice. Retarded proliferation of BCR-ABL1 -positive FANCD2−/− leukemia cells could be rescued by FANCD2 expression. BCR-ABL1 –positive FANCD2−/− cells accumulated more ROS-induced DSBs in comparison to BCR-ABL1 –positive FANCD2+/+ cells. Antioxidants diminished the number of DSBs and enhanced proliferation of BCR-ABL1 –positive FANCD2−/− cells. Expression of wild-type FANCD2 and FANCD2(S222A) phosphorylation-defective mutant (deficient in stimulation of intra-S phase checkpoint but proficient in DSB repair), but not FANCD2(K561R) monoubiquitination-defective mutant (proficient in stimulation of intra-S phase checkpoint but deficient in DSB repair) reduced the number of DSBs and facilitated proliferation of BCR-ABL1 –positive FANCD2−/− cells. We hypothesize that FANCD2-Ub plays an important role in BCR-ABL1 leukemogenesis due to its ability to facilitate the repair of numerous ROS-induced DSBs. PMID:21519342

  4. A cross-linker-sensitive myeloid leukemia cell line from a 2-year-old boy with severe Fanconi anemia and biallelic FANCD1/BRCA2 mutations.

    PubMed

    Meyer, Stefan; Fergusson, William D; Oostra, Anneke B; Medhurst, Annette L; Waisfisz, Quinten; de Winter, Johan P; Chen, Fei; Carr, Trevor F; Clayton-Smith, Jill; Clancy, Tara; Green, Mike; Barber, Lisa; Eden, Osborn B; Will, Andrew M; Joenje, Hans; Taylor, G Malcolm

    2005-04-01

    Fanconi anemia (FA) is a rare autosomal recessive disorder characterized by congenital and developmental abnormalities, hypersensitivity to DNA cross-linking agents such as mitomycin C (MMC), and strong predisposition to acute myeloid leukemia (AML). In this article, we describe clinical and molecular findings in a boy with a severe FA phenotype who developed AML by the age of 2. Although he lacked a strong family history of cancer, he was subsequently shown to carry biallelic mutations in the FANCD1/BRCA2 gene. These included an IVS7 splice-site mutation, which is strongly associated with early AML in homozygous or compound heterozygous carrier status in FA-D1 patients. Myeloid leukemia cells from this patient have been maintained in culture for more than 1 year and have been designated as the SB1690CB cell line. Growth of SB1690CB is dependent on granulocyte macrophage colony stimulating factor or interleukin-3. This cell line has retained its MMC sensitivity and has undergone further spontaneous changes in the spectrum of cytogenetic aberrations compared with the primary leukemia. This is the second AML cell line derived from an FA-D1 patient and the first proof that malignant clones arising in FA patients can retain inherited MMC sensitivity. As FA-derived malignancies are normally not very responsive to treatment, this implies there are important mechanisms of acquiring correction of the cellular FA phenotype that would explain the poor chemoresponsiveness observed in FA-associated malignancies and might also play a role in the initiation and progression of cancer in the general population.

  5. Crosstalk between Translesion Synthesis, Fanconi Anemia Network, and Homologous Recombination Repair Pathways in Interstrand DNA Crosslink Repair and Development of Chemoresistance

    PubMed Central

    Haynes, Brittany; Saadat, Nadia; Myung, Brian; Shekhar, Malathy PV

    2014-01-01

    Bifunctional alkylating and platinum based drugs are chemotherapeutic agents used to treat cancer. These agents induce DNA adducts via formation of intrastrand or interstrand (ICL) DNA crosslinks, and DNA lesions of the ICL type are particularly toxic as they block DNA replication and/or DNA transcription. However, the therapeutic efficacies of these drugs are frequently limited due to the cancer cell’s enhanced ability to repair and tolerate these toxic DNA lesions. This ability to tolerate and survive the DNA damage is accomplished by a set of specialized low fidelity DNA polymerases called translesion synthesis (TLS) polymerases since high fidelity DNA polymerases are unable to replicate the damaged DNA template. TLS is a crucial initial step in ICL repair as it synthesizes DNA across the lesion thus preparing the damaged DNA template for repair by the homologous recombination (HR) pathway and Fanconi anemia (FA) network, processes critical for ICL repair. Here we review the molecular features and functional roles of TLS polymerases, discuss the collaborative interactions and cross-regulation of the TLS DNA damage tolerance pathway, the FA network and the BRCA-dependent HRR pathway, and the impact of TLS hyperactivation on development of chemoresistance. Finally, since TLS hyperactivation results from overexpression of Rad6/Rad18 ubiquitinating enzymes (fundamental components of the TLS pathway), increased PCNA ubiquitination, and/or increased recruitment of TLS polymerases, the potential benefits of selectively targeting critical components of the TLS pathway for enhancing anti-cancer therapeutic efficacy and curtailing chemotherapy-induced mutagenesis are also discussed. PMID:25795124

  6. AluY-mediated germline deletion, duplication and somatic stem cell reversion in UBE2T defines a new subtype of Fanconi anemia.

    PubMed

    Virts, Elizabeth L; Jankowska, Anna; Mackay, Craig; Glaas, Marcel F; Wiek, Constanze; Kelich, Stephanie L; Lottmann, Nadine; Kennedy, Felicia M; Marchal, Christophe; Lehnert, Erik; Scharf, Rüdiger E; Dufour, Carlo; Lanciotti, Marina; Farruggia, Piero; Santoro, Alessandra; Savasan, Süreyya; Scheckenbach, Kathrin; Schipper, Jörg; Wagenmann, Martin; Lewis, Todd; Leffak, Michael; Farlow, Janice L; Foroud, Tatiana M; Honisch, Ellen; Niederacher, Dieter; Chakraborty, Sujata C; Vance, Gail H; Pruss, Dmitry; Timms, Kirsten M; Lanchbury, Jerry S; Alpi, Arno F; Hanenberg, Helmut

    2015-09-15

    Fanconi anemia (FA) is a rare inherited disorder clinically characterized by congenital malformations, progressive bone marrow failure and cancer susceptibility. At the cellular level, FA is associated with hypersensitivity to DNA-crosslinking genotoxins. Eight of 17 known FA genes assemble the FA E3 ligase complex, which catalyzes monoubiquitination of FANCD2 and is essential for replicative DNA crosslink repair. Here, we identify the first FA patient with biallelic germline mutations in the ubiquitin E2 conjugase UBE2T. Both mutations were aluY-mediated: a paternal deletion and maternal duplication of exons 2-6. These loss-of-function mutations in UBE2T induced a cellular phenotype similar to biallelic defects in early FA genes with the absence of FANCD2 monoubiquitination. The maternal duplication produced a mutant mRNA that could encode a functional protein but was degraded by nonsense-mediated mRNA decay. In the patient's hematopoietic stem cells, the maternal allele with the duplication of exons 2-6 spontaneously reverted to a wild-type allele by monoallelic recombination at the duplicated aluY repeat, thereby preventing bone marrow failure. Analysis of germline DNA of 814 normal individuals and 850 breast cancer patients for deletion or duplication of UBE2T exons 2-6 identified the deletion in only two controls, suggesting aluY-mediated recombinations within the UBE2T locus are rare and not associated with an increased breast cancer risk. Finally, a loss-of-function germline mutation in UBE2T was detected in a high-risk breast cancer patient with wild-type BRCA1/2. Cumulatively, we identified UBE2T as a bona fide FA gene (FANCT) that also may be a rare cancer susceptibility gene.

  7. AluY-mediated germline deletion, duplication and somatic stem cell reversion in UBE2T defines a new subtype of Fanconi anemia

    PubMed Central

    Virts, Elizabeth L.; Jankowska, Anna; Mackay, Craig; Glaas, Marcel F.; Wiek, Constanze; Kelich, Stephanie L.; Lottmann, Nadine; Kennedy, Felicia M.; Marchal, Christophe; Lehnert, Erik; Scharf, Rüdiger E.; Dufour, Carlo; Lanciotti, Marina; Farruggia, Piero; Santoro, Alessandra; Savasan, Süreyya; Scheckenbach, Kathrin; Schipper, Jörg; Wagenmann, Martin; Lewis, Todd; Leffak, Michael; Farlow, Janice L.; Foroud, Tatiana M.; Honisch, Ellen; Niederacher, Dieter; Chakraborty, Sujata C.; Vance, Gail H.; Pruss, Dmitry; Timms, Kirsten M.; Lanchbury, Jerry S.; Alpi, Arno F.; Hanenberg, Helmut

    2015-01-01

    Fanconi anemia (FA) is a rare inherited disorder clinically characterized by congenital malformations, progressive bone marrow failure and cancer susceptibility. At the cellular level, FA is associated with hypersensitivity to DNA-crosslinking genotoxins. Eight of 17 known FA genes assemble the FA E3 ligase complex, which catalyzes monoubiquitination of FANCD2 and is essential for replicative DNA crosslink repair. Here, we identify the first FA patient with biallelic germline mutations in the ubiquitin E2 conjugase UBE2T. Both mutations were aluY-mediated: a paternal deletion and maternal duplication of exons 2–6. These loss-of-function mutations in UBE2T induced a cellular phenotype similar to biallelic defects in early FA genes with the absence of FANCD2 monoubiquitination. The maternal duplication produced a mutant mRNA that could encode a functional protein but was degraded by nonsense-mediated mRNA decay. In the patient's hematopoietic stem cells, the maternal allele with the duplication of exons 2–6 spontaneously reverted to a wild-type allele by monoallelic recombination at the duplicated aluY repeat, thereby preventing bone marrow failure. Analysis of germline DNA of 814 normal individuals and 850 breast cancer patients for deletion or duplication of UBE2T exons 2–6 identified the deletion in only two controls, suggesting aluY-mediated recombinations within the UBE2T locus are rare and not associated with an increased breast cancer risk. Finally, a loss-of-function germline mutation in UBE2T was detected in a high-risk breast cancer patient with wild-type BRCA1/2. Cumulatively, we identified UBE2T as a bona fide FA gene (FANCT) that also may be a rare cancer susceptibility gene. PMID:26085575

  8. Novel function of the Fanconi anemia group J or RECQ1 helicase to disrupt protein-DNA complexes in a replication protein A-stimulated manner.

    PubMed

    Sommers, Joshua A; Banerjee, Taraswi; Hinds, Twila; Wan, Bingbing; Wold, Marc S; Lei, Ming; Brosh, Robert M

    2014-07-18

    Understanding how cellular machinery deals with chromosomal genome complexity is an important question because protein bound to DNA may affect various cellular processes of nucleic acid metabolism. DNA helicases are at the forefront of such processes, yet there is only limited knowledge how they remodel protein-DNA complexes and how these mechanisms are regulated. We have determined that representative human RecQ and Fe-S cluster DNA helicases are potently blocked by a protein-DNA interaction. The Fanconi anemia group J (FANCJ) helicase partners with the single-stranded DNA-binding protein replication protein A (RPA) to displace BamHI-E111A bound to duplex DNA in a specific manner. Protein displacement was dependent on the ATPase-driven function of the helicase and unique properties of RPA. Further biochemical studies demonstrated that the shelterin proteins TRF1 and TRF2, which preferentially bind the telomeric repeat found at chromosome ends, effectively block FANCJ from unwinding the forked duplex telomeric substrate. RPA, but not the Escherichia coli single-stranded DNA-binding protein or shelterin factor Pot1, stimulated FANCJ ejection of TRF1 from the telomeric DNA substrate. FANCJ was also able to displace TRF2 from the telomeric substrate in an RPA-dependent manner. The stimulation of helicase-catalyzed protein displacement is also observed with the DNA helicase RECQ1, suggesting a conserved functional interaction of RPA-interacting helicases. These findings suggest that partnerships between RPA and interacting human DNA helicases may greatly enhance their ability to dislodge proteins bound to duplex DNA, an activity that is likely to be highly relevant to their biological roles in DNA metabolism.

  9. Impaired TIP60-mediated H4K16 acetylation accounts for the aberrant chromatin accumulation of 53BP1 and RAP80 in Fanconi anemia pathway-deficient cells.

    PubMed

    Renaud, Emilie; Barascu, Aurelia; Rosselli, Filippo

    2016-01-29

    To rescue collapsed replication forks cells utilize homologous recombination (HR)-mediated mechanisms to avoid the induction of gross chromosomal abnormalities that would be generated by non-homologous end joining (NHEJ). Using DNA interstrand crosslinks as a replication barrier, we investigated how the Fanconi anemia (FA) pathway promotes HR at stalled replication forks. FA pathway inactivation results in Fanconi anemia, which is associated with a predisposition to cancer. FANCD2 monoubiquitination and assembly in subnuclear foci appear to be involved in TIP60 relocalization to the chromatin to acetylates histone H4K16 and prevents the binding of 53BP1 to its docking site, H4K20Me2. Thus, FA pathway loss-of-function results in accumulation of 53BP1, RIF1 and RAP80 at damaged chromatin, which impair DNA resection at stalled replication fork-associated DNA breaks and impede HR. Consequently, DNA repair in FA cells proceeds through the NHEJ pathway, which is likely responsible for the accumulation of chromosome abnormalities. We demonstrate that the inhibition of NHEJ or deacetylase activity rescue HR in FA cells.

  10. The conserved Fanconi anemia nuclease Fan1 and the SUMO E3 ligase Pli1 act in two novel Pso2-independent pathways of DNA interstrand crosslink repair in yeast

    PubMed Central

    Fontebasso, Y.; Etheridge, T.J.; Oliver, A.W.; Murray, J.M.; Carr, A.M.

    2013-01-01

    DNA interstrand cross-links (ICLs) represent a physical barrier to the progression of cellular machinery involved in DNA metabolism. Thus, this type of adduct represents a serious threat to genomic stability and as such, several DNA repair pathways have evolved in both higher and lower eukaryotes to identify this type of damage and restore the integrity of the genetic material. Human cells possess a specialized ICL-repair system, the Fanconi anemia (FA) pathway. Conversely yeasts rely on the concerted action of several DNA repair systems. Recent work in higher eukaryotes identified and characterized a novel conserved FA component, FAN1 (Fanconi anemia-associated nuclease 1, or FANCD2/FANCI-associated nuclease 1). In this study, we characterize Fan1 in the yeast Schizosaccharomyces pombe. Using standard genetics, we demonstrate that Fan1 is a key component of a previously unidentified ICL-resolution pathway. Using high-throughput synthetic genetic arrays, we also demonstrate the existence of a third pathway of ICL repair, dependent on the SUMO E3 ligase Pli1. Finally, using sequence-threaded homology models, we predict and validate key residues essential for Fan1 activity in ICL repair. PMID:24192486

  11. A systems biology approach for elucidating the interaction of curcumin with Fanconi anemia FANC G protein and the key disease targets of leukemia.

    PubMed

    Mahato, David; Samanta, Dipayan; Mukhopadhyay, Sudit S; Krishnaraj, R Navanietha

    2017-06-01

    Fanconi anemia (FA) is an autosomal recessive disorder with a high risk of malignancies including acute myeloid leukemia and squamous cell carcinoma. There is a constant search out of new potential therapeutic molecule to combat this disorder. In most cases, patients with FA develop haematological malignancies with acute myeloid leukemia and acute lymphoblastic leukemia. Identifying drugs which can efficiently block the pathways of both these disorders can be an ideal and novel strategy to treat FA. The curcumin, a natural compound obtained from turmeric is an interesting therapeutic molecule as it has been reported in the literature to combat both FA as well as leukemia. However, its complete mechanism is not elucidated. Herein, a systems biology approach for elucidating the therapeutic potential of curcumin against FA and leukemia is investigated by analyzing the computational molecular interactions of curcumin ligand with FANC G of FA and seven other key disease targets of leukemia. The proteins namely DOT1L, farnesyl transferase (FDPS), histone decetylase (EP3000), Polo-like kinase (PLK-2), aurora-like kinase (AUKRB), tyrosine kinase (ABL1), and retinoic acid receptor alpha (RARA) were chosen as disease targets for leukemia and modeled structure of FANC G protein as the disease target for FA. The docking investigations showed that curcumin had a very high binding affinity of -8.1 kcal/mol with FANC G protein. The key disease targets of leukemia namely tyrosine kinase (ABL1), aurora-like kinase (AUKRB), and polo-like kinase (PLK-2) showed that they had the comparable binding affinities of -9.7 k cal/mol, -8.7 k cal/mol, and -8.6 k cal/mol, respectively with curcumin. Further, the percentage similarity scores obtained from PAM50 using EMBOSS MATCHER was shown to provide a clue to understand the structural relationships to an extent and to predict the binding affinity. This investigation shows that curcumin effectively interacts with the disease targets of both

  12. Complement deposition in autoimmune hemolytic anemia is a footprint for difficult-to-detect IgM autoantibodies.

    PubMed

    Meulenbroek, Elisabeth M; de Haas, Masja; Brouwer, Conny; Folman, Claudia; Zeerleder, Sacha S; Wouters, Diana

    2015-11-01

    In autoimmune hemolytic anemia autoantibodies against erythrocytes lead to increased clearance of the erythrocytes, which in turn results in a potentially fatal hemolytic anemia. Depending on whether IgG or IgM antibodies are involved, response to therapy is different. Proper identification of the isotype of the anti-erythrocyte autoantibodies is, therefore, crucial. However, detection of IgM autoantibodies can be challenging. We, therefore, set out to improve the detection of anti-erythrocyte IgM. Direct detection using a flow cytometry-based approach did not yield satisfactory improvements. Next, we analyzed whether the presence of complement C3 on a patient's erythrocytes could be used for indirect detection of anti-erythrocyte IgM. To this end, we fractionated patients' sera by size exclusion chromatography and tested which fractions yielded complement deposition on erythrocytes. Strikingly, we found that all patients with C3 on their erythrocytes according to standard diagnostic tests had an IgM anti-erythrocyte component that could activate complement, even if no such autoantibody had been detected with any other test. This also included all tested patients with only IgG and C3 on their erythrocytes, who would previously have been classified as having an IgG-only mediated autoimmune hemolytic anemia. Depleting patients' sera of either IgG or IgM and testing the remaining complement activation confirmed this result. In conclusion, complement activation in autoimmune hemolytic anemia is mostly IgM-mediated and the presence of covalent C3 on patients' erythrocytes can be taken as a footprint of the presence of anti-erythrocyte IgM. Based on this finding, we propose a diagnostic workflow that will aid in choosing the optimal treatment strategy.

  13. Outcomes after related and unrelated umbilical cord blood transplantation for hereditary bone marrow failure syndromes other than Fanconi anemia

    PubMed Central

    Bizzetto, Renata; Bonfim, Carmen; Rocha, Vanderson; Socié, Gérard; Locatelli, Franco; Chan, KaWah; Ramirez, Oscar; Stein, Joel; Nabhan, Samir; Miranda, Eliana; Passweg, Jakob; de Souza, Carmino Antonio; Gluckman, Eliane

    2011-01-01

    Background Allogeneic stem cell transplantation is the only curative option for patients with hereditary bone marrow failure syndromes. Umbilical cord blood is an alternative source of stem cells for allogeneic transplantation. Design and Methods This multicenter, retrospective study is based on data reported to the Eurocord Registry about patients with hereditary bone marrow failure syndrome who underwent umbilical cord blood transplantation. Results Sixty-four patients with hereditary bone marrow failure syndromes were transplanted from related (n=20) or unrelated donors (n=44). Diagnoses were Diamond-Blackfan anemia (21 patients), congenital amegakaryocytic thrombocytopenia (16 patients), dyskeratosis congenita (8 patients), Shwachman-Diamond syndrome (2 patients), severe congenital neutropenia (16 patients) and unclassified (1 patient). In the group of patients who received grafts from related donors, all patients but one received an HLA-matched sibling transplant. The median number of total nucleated cells infused was 5×107/kg. The cumulative incidence of neutrophil recovery at 60 days was 95%. Two patients had grade II–IV acute graft-versus-host disease, while the 2-year cumulative incidence of chronic graft-versus-host disease was 11%. The 3-year overall survival rate was 95%. In the group of patients who received grafts from unrelated donors, 86% had HLA-mismatched grafts and three received two umbilical cord blood units. The median number of total nucleated cells infused was 6.1×107/kg. The cumulative incidence of neutrophil recovery at day 60 in this group was 55%. The 100-day cumulative incidence of grade II–IV acute graft-versus-host disease was 24%, while the 2-year cumulative incidence of chronic graft-versus-host disease was 53%. The 3-year overall survival rate was 61%; better overall survival was associated with age less than 5 years (P=0.01) and 6.1×107/kg or more total nucleated cells infused (P=0.05). Conclusions In patients with

  14. Red blood cell destruction in autoimmune hemolytic anemia: role of complement and potential new targets for therapy.

    PubMed

    Berentsen, Sigbjørn; Sundic, Tatjana

    2015-01-01

    Autoimmune hemolytic anemia (AIHA) is a collective term for several diseases characterized by autoantibody-initiated destruction of red blood cells (RBCs). Exact subclassification is essential. We provide a review of the respective types of AIHA with emphasis on mechanisms of RBC destruction, focusing in particular on complement involvement. Complement activation plays a definitive but limited role in warm-antibody AIHA (w-AIHA), whereas primary cold agglutinin disease (CAD), secondary cold agglutinin syndrome (CAS), and paroxysmal cold hemoglobinuria (PCH) are entirely complement-dependent disorders. The details of complement involvement differ among these subtypes. The theoretical background for therapeutic complement inhibition in selected patients is very strong in CAD, CAS, and PCH but more limited in w-AIHA. The optimal target complement component for inhibition is assumed to be important and highly dependent on the type of AIHA. Complement modulation is currently not an evidence-based therapy modality in any AIHA, but a number of experimental and preclinical studies are in progress and a few clinical observations have been reported. Clinical studies of new complement inhibitors are probably not far ahead.

  15. Red Blood Cell Destruction in Autoimmune Hemolytic Anemia: Role of Complement and Potential New Targets for Therapy

    PubMed Central

    Berentsen, Sigbjørn

    2015-01-01

    Autoimmune hemolytic anemia (AIHA) is a collective term for several diseases characterized by autoantibody-initiated destruction of red blood cells (RBCs). Exact subclassification is essential. We provide a review of the respective types of AIHA with emphasis on mechanisms of RBC destruction, focusing in particular on complement involvement. Complement activation plays a definitive but limited role in warm-antibody AIHA (w-AIHA), whereas primary cold agglutinin disease (CAD), secondary cold agglutinin syndrome (CAS), and paroxysmal cold hemoglobinuria (PCH) are entirely complement-dependent disorders. The details of complement involvement differ among these subtypes. The theoretical background for therapeutic complement inhibition in selected patients is very strong in CAD, CAS, and PCH but more limited in w-AIHA. The optimal target complement component for inhibition is assumed to be important and highly dependent on the type of AIHA. Complement modulation is currently not an evidence-based therapy modality in any AIHA, but a number of experimental and preclinical studies are in progress and a few clinical observations have been reported. Clinical studies of new complement inhibitors are probably not far ahead. PMID:25705656

  16. Somatic, hematologic phenotype, long-term outcome, and effect of hematopoietic stem cell transplantation. An analysis of 97 Fanconi anemia patients from the Italian national database on behalf of the Marrow Failure Study Group of the AIEOP (Italian Association of Pediatric Hematology-Oncology).

    PubMed

    Svahn, Johanna; Bagnasco, Francesca; Cappelli, Enrico; Onofrillo, Daniela; Caruso, Silvia; Corsolini, Fabio; De Rocco, Daniela; Savoia, Anna; Longoni, Daniela; Pillon, Marta; Marra, Nicoletta; Ramenghi, Ugo; Farruggia, Piero; Locasciulli, Anna; Addari, Carmen; Cerri, Carla; Mastrodicasa, Elena; Casazza, Gabriella; Verzegnassi, Federico; Riccardi, Francesca; Haupt, Riccardo; Barone, Angelica; Cesaro, Simone; Cugno, Chiara; Dufour, Carlo

    2016-07-01

    We analyzed 97 Fanconi anemia patients from a clinic/biological database for genotype, somatic, and hematologic phenotype, adverse hematological events, solid tumors, and treatment. Seventy-two patients belonged to complementation group A. Eighty percent of patients presented with mild/moderate somatic phenotype and most with cytopenia. No correlation was seen between somatic/hematologic phenotype and number of missense mutations of FANCA alleles. Over follow-up, 33% of patients improved or maintained mild/moderate cytopenia or normal blood count, whereas remaining worsened cytopenia. Eleven patients developed a hematological adverse event (MDS, AML, pathological cytogenetics) and three developed solid tumors. 10 years cumulative risk of death of the whole cohort was 25.6% with median follow-up 5.8 years. In patients eligible to hematopoietic stem cell transplantation because of moderate cytopenia, mortality was significantly higher in subjects transplanted from matched unrelated donor over nontransplanted subjects, whereas there was no significant difference between matched sibling donor transplants and nontransplanted patients. In patients eligible to transplant because of severe cytopenia and clonal disease, mortality risk was not significantly different in transplanted from matched unrelated versus matched sibling donor versus nontransplanted subjects. The decision to transplant should rely on various elements including, type of donor, HLA matching, patient comorbidities, impairment, and clonal evolution of hematopoiesis. Am. J. Hematol. 91:666-671, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Complement

    MedlinePlus

    ... fungal infections and some parasitic infections such as malaria . Normal Results Total blood complement level: 41 to ... Glomerulonephritis Hepatitis Hereditary angioedema Kidney transplant Lupus nephritis Malaria Protein in diet Rheumatoid arthritis Septicemia Shock Systemic ...

  18. How Is Fanconi Anemia Diagnosed?

    MedlinePlus

    ... FA. Genetic tests for FA include the following. Chromosome Breakage Test This is the most common test ... in special laboratories (labs). It shows whether your chromosomes (long chains of genes) break more easily than ...

  19. Genetics Home Reference: Fanconi anemia

    MedlinePlus

    ... when the process of making new copies of DNA, called DNA replication , is blocked due to DNA damage. The FA pathway sends certain proteins to the area of damage, which trigger DNA repair so DNA replication can continue. The FA ...

  20. Anemias.

    PubMed

    Broadway-Duren, Jacqueline B; Klaassen, Hillary

    2013-12-01

    Anemias continue to present a challenge to the health care profession. Anemia is defined as a reduction in one or more of the RBC indices. Patients presenting with a mild form of anemia may be asymptomatic; however, in more serious cases the anemia can become life threatening. In many cases the clinical presentation also reflects the underlying cause. Anemia may be attributed to various causes, whereas autoimmune RBC destruction may be attributed to intrinsic and extrinsic factors. Laboratory tests are essential in facilitating early detection and differentiation of anemia.

  1. Anemia

    MedlinePlus

    ... a shortage of iron. This condition is called iron deficiency anemia.There are a few other types of ... Try to avoid these foods if you have iron deficiency anemia.Foods high in vitamin B12 include:meat ...

  2. Equine infectious anemia: preparation of a liquid antigen extract for the agar-gel immunodiffusion and complement-fixation tests.

    PubMed

    Boulanger, P; Bannister, G L; Carrier, S P

    1972-04-01

    An agar-gel immunodiffusion test recommended for the diagnosis of equine infectious anemia was evaluated. Our preliminary observations confirmed those of Coggins concerning the mechanism of the test and the results obtained. Furthermore, emphasis was put on the difficulties encountered in the production of spleen antigens with an optimum amount of reactivity. Acetone-ether extraction procedures for the preparation of a liquid antigen extract are described. This type of antigen was reactive in the complement-fixation test in 1:8 or greater dilution and it is proposed to use the complement-fixation test in assessing and standardizing the liquid antigen extract activity to be used in the immunodiffusion test. This antigen can also be concentrated or diluted, if required, to meet the reactivity of a standard antigen used in the test.

  3. Equine Infectious Anemia: Preparation of a Liquid Antigen Extract for the Agar-gel Immunodiffusion and Complement-fixation Tests

    PubMed Central

    Boulanger, P.; Bannister, G. L.; Carrier, S. P.

    1972-01-01

    An agar-gel immunodiffusion test recommended for the diagnosis of equine infectious anemia was evaluated. Our preliminary observations confirmed those of Coggins concerning the mechanism of the test and the results obtained. Furthermore, emphasis was put on the difficulties encountered in the production of spleen antigens with an optimum amount of reactivity. Acetone-ether extraction procedures for the preparation of a liquid antigen extract are described. This type of antigen was reactive in the complement-fixation test in 1:8 or greater dilution and it is proposed to use the complement-fixation test in assessing and standardizing the liquid antigen extract activity to be used in the immunodiffusion test. This antigen can also be concentrated or diluted, if required, to meet the reactivity of a standard antigen used in the test. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 4.Fig. 5.Fig. 6. PMID:4259924

  4. Amelioration of radiation-induced oral cavity mucositis and distant bone marrow suppression in fanconi anemia Fancd2-/- (FVB/N) mice by intraoral GS-nitroxide JP4-039.

    PubMed

    Berhane, Hebist; Shinde, Ashwin; Kalash, Ronny; Xu, Karen; Epperly, Michael W; Goff, Julie; Franicola, Darcy; Zhang, Xichen; Dixon, Tracy; Shields, Donna; Wang, Hong; Wipf, Peter; Li, Song; Gao, Xiang; Greenberger, Joel S

    2014-07-01

    The altered DNA damage response pathway in patients with Fanconi anemia (FA) may increase the toxicity of clinical radiotherapy. We quantitated oral cavity mucositis in irradiated Fanconi anemia Fancd2(-/-) mice, comparing this to Fancd2(+/-) and Fancd2(+/+) mice, and we measured distant bone marrow suppression and quantitated the effect of the intraoral radioprotector GS-nitroxide, JP4-039 in F15 emulsion. We found that FA mice were more susceptible to radiation injury and that protection from radiation injury by JP4-039/F15 was observed at all radiation doses. Adult 10-12-week-old mice, of FVB/N background Fancd2(-/-), Fancd2(+/-) and Fancd2(+/+) were head and neck irradiated with 24, 26, 28 or 30 Gy (large fraction sizes typical of stereotactic radiosurgery treatments) and subgroups received intraoral JP4-039 (0.4 mg/mouse in 100 μL F15 liposome emulsion) preirradiation. On day 2 or 5 postirradiation, mice were sacrificed, tongue tissue and femur marrow were excised for quantitation of radiation-induced stress response, inflammatory and antioxidant gene transcripts, histopathology and assay for femur marrow colony-forming hematopoietic progenitor cells. Fancd2(-/-) mice had a significantly higher percentage of oral mucosal ulceration at day 5 after 26 Gy irradiation (59.4 ± 8.2%) compared to control Fancd2(+/+) mice (21.7 ± 2.9%, P = 0.0063). After 24 Gy irradiation, Fancd2(-/-) mice had a higher oral cavity percentage of tongue ulceration compared to Fancd2(+/+) mice irradiated with higher doses of 26 Gy (P = 0.0123). Baseline and postirradiation oral cavity gene transcripts were altered in Fancd2(-/-) mice compared to Fancd2(+/+) controls. Fancd2(-/-) mice had decreased baseline femur marrow CFU-GM, BFUe and CFU-GEMM, which further decreased after 24 or 26 Gy head and neck irradiation. These changes were not seen in head- and neck-irradiated Fancd2(+/+) mice. In radiosensitive Fancd2(-/-) mice, biomarkers of both local oral cavity and distant marrow

  5. Amelioration of Radiation-Induced Oral Cavity Mucositis and Distant Bone Marrow Suppression in Fanconi Anemia Fancd2−/− (FVB/N) Mice by Intraoral GS-Nitroxide JP4-039

    PubMed Central

    Berhane, Hebist; Shinde, Ashwin; Kalash, Ronny; Xu, Karen; Epperly, Michael W.; Goff, Julie; Franicola, Darcy; Zhang, Xichen; Dixon, Tracy; Shields, Donna; Wang, Hong; Wipf, Peter; Li, Song; Gao, Xiang; Greenberger, Joel S.

    2014-01-01

    The altered DNA damage response pathway in patients with Fanconi anemia (FA) may increase the toxicity of clinical radiotherapy. We quantitated oral cavity mucositis in irradiated Fanconi anemia Fancd2−/− mice, comparing this to Fancd2+/− and Fancd2+/+ mice, and we measured distant bone marrow suppression and quantitated the effect of the intraoral radioprotector GS-nitroxide, JP4-039 in F15 emulsion. We found that FA mice were more susceptible to radiation injury and that protection from radiation injury by JP4-039/F15 was observed at all radiation doses. Adult 10–12-week-old mice, of FVB/N background Fancd2−/−, Fancd2+/− and Fancd2+/+ were head and neck irradiated with 24, 26, 28 or 30 Gy (large fraction sizes typical of stereotactic radiosurgery treatments) and subgroups received intraoral JP4-039 (0.4 mg/mouse in 100 μL F15 liposome emulsion) preirradiation. On day 2 or 5 postirradiation, mice were sacrificed, tongue tissue and femur marrow were excised for quantitation of radiation-induced stress response, inflammatory and antioxidant gene transcripts, histopathology and assay for femur marrow colony-forming hematopoietic progenitor cells. Fancd2−/− mice had a significantly higher percentage of oral mucosal ulceration at day 5 after 26 Gy irradiation (59.4 ± 8.2%) compared to control Fancd2+/+ mice (21.7 ± 2.9%, P = 0.0063). After 24 Gy irradiation, Fancd2−/− mice had a higher oral cavity percentage of tongue ulceration compared to Fancd2+/+ mice irradiated with higher doses of 26 Gy (P = 0.0123). Baseline and postirradiation oral cavity gene transcripts were altered in Fancd2−/− mice compared to Fancd2+/+ controls. Fancd2−/− mice had decreased baseline femur marrow CFU-GM, BFUe and CFU-GEMM, which further decreased after 24 or 26 Gy head and neck irradiation. These changes were not seen in head- and neck-irradiated Fancd2+/+ mice. In radiosensitive Fancd2−/− mice, biomarkers of both local oral cavity and distant marrow

  6. The Fanconi family adds a fraternal twin.

    PubMed

    Grompe, Markus; van de Vrugt, Henri

    2007-05-01

    The Fanconi anemia (FA) pathway plays an important role in DNA repair. In a recent issue of Cell, Smogorzewska et al. (2007) now demonstrate that FANCD2 has a paralog, FANCI. FANCI and FANCD2 form the "ID" complex that loads onto chromatin after DNA damage. Like FANCD2, monoubiquitination of FANCI requires the FA core complex. Importantly, FANCI and FANCD2 monoubiquitination is co-dependent, suggesting a novel mechanism in ubiquitin conjugation.

  7. Analysis of 133 meioses places the genes for nevoid basal cell carcinoma (gorlin) syndrome and fanconi anemia group C in a 2.6-cM interval and contributes to the fine map of 9q22.3

    SciTech Connect

    Farndon, P.A.; Hardy, C.; Kilpatrick, M.W.

    1994-09-15

    Four disease genes (NBCCS, ESS1, XPAC, FACC) map to 9q22.3-q31. A fine map of this region was produced by linkage and haplotype analysis using 12 DNA markers. The gene for nevoid basal cell carcinoma syndrome (NBCCS, Gorlin) has an important role in congenital malformations and carcinogenesis. Phase-known recombinants in a study of 133 meioses place NBCCS between (D9S12/D9S151) and D9S176. Haplotype analysis in a two-generation family suggests that NBCCS lies in a smaller interval of 2.6 cM centromeric to D9S287. These flanking markers will be useful clinically for gene tracking. Recombinants also map FACC (Fanconi anemia, group C) to the same region, between (D9S12/D9S151) and D9S287. The recombination rate between (D9S12/D9S151) and D9S53 in males is 8.3% and 13.2% in females, giving a sex-specific male:female ratio of 1:1.6 and a sex-averaged map distance of 10.4 cM. No double recombinants were detected, in agreement with the apparently complete level of interference predicted from the male chiasmata map. 19 refs., 2 figs., 1 tab.

  8. Replication of chicken anemia virus (CAV) requires apoptin and is complemented by VP3 of human torque teno virus (TTV).

    PubMed

    Prasetyo, Afiono Agung; Kamahora, Toshio; Kuroishi, Ayumu; Murakami, Kyoko; Hino, Shigeo

    2009-03-01

    To test requirement for apoptin in the replication of chicken anemia virus (CAV), an apoptin-knockout clone, pCAV/Ap(-), was constructed. DNA replication was completely abolished in cells transfected with replicative form of CAV/Ap(-). A reverse mutant competent in apoptin production regained the full level of DNA replication. DNA replication and virus-like particle (VLP) production of CAV/Ap(-) was fully complemented by supplementation of the wild-type apoptin. The virus yield of a point mutant, CAV/ApT(108)I, was 1/40 that of the wild type, even though its DNA replication level was full. The infectious titer of CAV was fully complemented by supplementing apoptin. Progeny virus was free from reverse mutation for T(108)I. To localize the domain within apoptin molecule inevitable for CAV replication, apoptin-mutant expressing plasmids, pAp1, pAp2, pAp3, and pAp4, were constructed by deleting amino acids 10-36, 31-59, 59-88 and 80-112, respectively. While Ap1 and Ap2 were preferentially localized in nuclei, Ap3 and Ap4 were mainly present in cytoplasm. Although complementation capacity of Ap3 and Ap4 was 1/10 of the wild type, neither of them completely lost its activity. VP3 of TTV did fully complement the DNA replication and VLP of CAV/Ap(-). These data suggest that apoptin is inevitable not only for DNA replication but also VLP of CAV. The common feature of apoptin and TTV-VP3 presented another evidence for close relatedness of CAV and TTV.

  9. Anemia

    MedlinePlus

    ... gives the red color to blood. It carries oxygen from the lungs to the rest of the body. Anemia has three main causes: blood loss, lack of red blood cell production, and high rates of red blood cell destruction. ...

  10. Anemia

    MedlinePlus

    ... Adults Making Your Wishes Known Home & Community Home › Aging & Health A to Z › Anemia Font size A A A Print Share Glossary Basic Facts & Information Causes & Symptoms Diagnosis & Tests Care & Treatment Lifestyle & Management Other Resources Caregiving How ...

  11. siRNA screening identifies differences in the Fanconi anemia pathway in BALB/c-Trp53+/− with susceptibility versus C57BL/6-Trp53+/− mice with resistance to mammary tumors

    PubMed Central

    Böhringer, M; Obermeier, K; Griner, N; Waldraff, D; Dickinson, E; Eirich, K; Schindler, D; Hagen, M; Jerry, D J; Wiesmüller, L

    2013-01-01

    BALB/c mice heterozygous for Trp53 develop a high proportion of spontaneous mammary tumors, a phenotype distinct from other mouse strains. BALB/c-Trp53+/− female mice, thus, resemble the hereditary Li-Fraumeni syndrome (LFS) characterized by early-onset of breast cancer, even though LFS involves TP53 mutations, which may involve not only loss- but also gain-of-function. Previous analysis of tumors in BALB/c-Trp53+/− females showed frequent loss of heterozygosity involving the wild-type allele of Trp53 and displayed characteristics indicative of mitotic recombination. Critical involvement of DNA double-strand break (DSB) repair dysfunction, particularly of homologous recombination (HR), was also noticed in the etiology of human breast cancer. To better define functional alterations in BALB/c-Trp53+/− mice, we applied a fluorescence-based DSB repair assay on mouse embryonic fibroblasts (MEFs) from BALB/c-Trp53+/− versus C57BL/6J-Trp53+/− mice. This approach revealed deregulation of HR but not non-homologous end-joining (NHEJ) in BALB/c-Trp53+/−, which was further confirmed for mammary epithelial cells. Screening of a small interfering RNA-library targeting DSB repair, recombination, replication and signaling genes, identified 25 genes causing differences between homologous DSB repair in the two strains upon silencing. Interactome analysis of the hits revealed clustering of replication-related and fanconi anemia (FA)/breast cancer susceptibility (BRCA) genes. Further dissection of the functional change in BALB/c-Trp53+/− by immunofluorescence microscopy of nuclear 53BP1, Replication protein A (RPA) and Rad51 foci uncovered differences in crosslink and replication-associated repair. Chromosome breakage, G2 arrest and biochemical analyses indicated a FA pathway defect downstream of FancD2 associated with reduced levels of BRCA2. Consistent with polygenic models for BRCA, mammary carcinogenesis in BALB/c-Trp53+/− mice may, therefore, be promoted by a BRCA

  12. siRNA screening identifies differences in the Fanconi anemia pathway in BALB/c-Trp53+/- with susceptibility versus C57BL/6-Trp53+/- mice with resistance to mammary tumors.

    PubMed

    Böhringer, M; Obermeier, K; Griner, N; Waldraff, D; Dickinson, E; Eirich, K; Schindler, D; Hagen, M; Jerry, D J; Wiesmüller, L

    2013-11-28

    BALB/c mice heterozygous for Trp53 develop a high proportion of spontaneous mammary tumors, a phenotype distinct from other mouse strains. BALB/c-Trp53+/- female mice, thus, resemble the hereditary Li-Fraumeni syndrome (LFS) characterized by early-onset of breast cancer, even though LFS involves TP53 mutations, which may involve not only loss- but also gain-of-function. Previous analysis of tumors in BALB/c-Trp53+/- females showed frequent loss of heterozygosity involving the wild-type allele of Trp53 and displayed characteristics indicative of mitotic recombination. Critical involvement of DNA double-strand break (DSB) repair dysfunction, particularly of homologous recombination (HR), was also noticed in the etiology of human breast cancer. To better define functional alterations in BALB/c-Trp53+/- mice, we applied a fluorescence-based DSB repair assay on mouse embryonic fibroblasts (MEFs) from BALB/c-Trp53+/- versus C57BL/6J-Trp53+/- mice. This approach revealed deregulation of HR but not non-homologous end-joining (NHEJ) in BALB/c-Trp53+/-, which was further confirmed for mammary epithelial cells. Screening of a small interfering RNA-library targeting DSB repair, recombination, replication and signaling genes, identified 25 genes causing differences between homologous DSB repair in the two strains upon silencing. Interactome analysis of the hits revealed clustering of replication-related and fanconi anemia (FA)/breast cancer susceptibility (BRCA) genes. Further dissection of the functional change in BALB/c-Trp53+/- by immunofluorescence microscopy of nuclear 53BP1, Replication protein A (RPA) and Rad51 foci uncovered differences in crosslink and replication-associated repair. Chromosome breakage, G2 arrest and biochemical analyses indicated a FA pathway defect downstream of FancD2 associated with reduced levels of BRCA2. Consistent with polygenic models for BRCA, mammary carcinogenesis in BALB/c-Trp53+/- mice may, therefore, be promoted by a BRCA modifier allele

  13. Diagnosis of Fanconi's anemia by flow cytometry.

    PubMed

    Miglierina, R; Le Coniat, M; Gendron, M; Berger, R

    1990-01-01

    FA is a progressive bone marrow aplasia genetically transmitted by a recessive autosomal gene or genes. In our laboratory, cytogenetic diagnosis is based on evaluation of the chromosomal breakage of mitotic cell derived from patient blood-cell cultures and sensitized by nitrogen mustard (NM). We have observed, in parallel with this test, fluctuations of the cell cycle of PHA- stimulated peripheral blood lymphocytes from FA patients as compared with controls. FA cells treated with NM show a dramatic and significant increase in G2/M phase after 72 hr in vitro culture, compared with untreated or control cells (normal controls and non-FA patients). This test is rapid and simple, as it consists in staining cells with a DNA dye (propidium iodide), followed by a flow cytometry analysis of the cell cycle phases. Our results in twelve patients are correlated with the cytogenetic results.

  14. [The Fanconi-Bickel syndrome].

    PubMed

    Velásquez, L; Portillo, V H; Sanjinés, R; Gamboa, J D; Feria-Kaiser, C; Valencia, P

    1991-04-01

    This is a case of a 15-month-old child suffering from Fanconi-Bickel syndrome, characterized with Fanconi syndrome manifestations (glycosuria, amino aciduria and phosphaturia), and the build-up of glycogen in the liver in a similar manner as seen in cases of glycogenesis type Ia. Due to the presence of liver glycogenosis, the patient also has a tendency towards hypoglycemia, ketonuria, hypercholesterolemia and hypertriglyceridemia. The glycogenosis seen in the patients with the Fanconi-Bickel syndrome, does not depend on a defect in the activity of the glucose-6-phosphatase enzyme, but in fact is due to a defect in the transporter which mobilizes glucose and galactose in the liver and in the basolateral membrane of the proximal tubule of the kidney.

  15. The Role of Fanconi/BRCA DNA Repair Pathway in Epithelial Ovarian Carcinogenesis

    DTIC Science & Technology

    2015-01-01

    PRINCIPAL INVESTIGATOR: Tanja Pejovic CONTRACTING ORGANIZATION: Oregon Health & Science University...TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Oregon Health & Science University 2525 Southwest 1st Avenue...Role in Ovarian Tumorigenesis Hays, L.E1, McWeeney S2, and Pejovic, T3. 1Fanconi Anemia Research Fund, Eugene, Oregon 2Department of Medical

  16. Transient Fanconi syndrome in Quarter horses

    PubMed Central

    Ohmes, Cameon M.; Davis, Elizabeth G.; Beard, Laurie A.; Vander Werf, Karie A.; Bianco, Alex W.; Giger, Urs

    2014-01-01

    Two Quarter horses with weight loss had glucosuria, euglycemia, and a mild metabolic acidosis suggesting a proximal renal tubular defect. Further testing revealed transient generalized aminoaciduria, lactic aciduria, and glucosuria, indicating Fanconi syndrome. Both horses recovered with supportive therapy. This is the first report of acquired Fanconi syndrome in horses. PMID:24489393

  17. Post-irradiation phosphorylation of structural maintenance chromosome 1 (SMC1) is independent of the Fanconi protein pathway

    SciTech Connect

    Nahas, Shareef A.; Lai, C.-H.; Gatti, Richard A. . E-mail: rgatti@mednet.ucla.edu

    2005-03-15

    Purpose: To confirm the sensitivity of cells from patients with Fanconi anemia (FA) to ionizing radiation, and to determine whether the phosphorylation of structural maintenance chromosome 1 (SMC1) was associated with radiosensitivity, as it is in other DNA repair disorders. Methods and materials: Using lymphoblastoid cell lines from FA patients before and after exposure to ionizing radiation, the colony survival assay, radioresistant DNA synthesis, and SMC1 phosphorylation were measured. FA lymphoblastoid cell lines that had been transfected with the wild-type FANC gene were used as controls. Results: Cells from FA patients of six complementation groups were radiosensitive. Despite this, SMC1 phosphorylation was normal in each case; radioresistant DNA synthesis, a measure of S phase checkpoint integrity, was defective in FANCD2 lymphoblastoid cell lines and was corrected in FANCD2 + D2 cells. Conclusions: The data indicate that the FANC pathway proteins play a major role in the cellular responses to ionizing radiation, but not in SMC1 phosphorylation or in the S phase checkpoint of FANCD2-deficient cells. Thus, SMC1 activation is not a common denominator of radiosensitivity, as has been suggested by radiation responses of cells from ataxia-telangiectasia, Nijmegen breakage syndrome, or Mre11 deficiency patients.

  18. Impaired function of Fanconi anemia type C-deficient macrophages.

    PubMed

    Liu, Ying; Ballman, Kimberly; Li, Deqiang; Khan, Shehnaz; Derr-Yellin, Ethel; Shou, Weinian; Haneline, Laura S

    2012-02-01

    FA is a genetic disorder characterized by BM failure, developmental defects, and cancer predisposition. Previous studies suggest that FA patients exhibit alterations in immunologic function. However, it is unclear whether the defects are immune cell-autonomous or secondary to leukopenia from evolving BM failure. Given the central role that macrophages have in the innate immune response, inflammation resolution, and antigen presentation for acquired immunity, we examined whether macrophages from Fancc-/- mice exhibit impaired function. Peritoneal inflammation induced by LPS or sodium periodate resulted in reduced monocyte/macrophage recruitment in Fancc-/- mice compared with WT controls. Fancc-/- mice also had decreased inflammatory monocytes mobilized into the peripheral blood after LPS treatment compared with controls. Furthermore, Fancc-/- peritoneal macrophages displayed cell-autonomous defects in function, including impaired adhesion to FN or endothelial cells, reduced chemoattractant-mediated migration, and decreased phagocytosis. Moreover, dysregulated F-actin rearrangement was detected in Fancc-/- macrophages after adhesion to FN, which was consistent with an observed reduction in RhoA-GTP levels. Importantly, these data suggest that impaired cytoskeletal rearrangements in Fancc-/- macrophages may be the common mechanism responsible for cell-autonomous defects detected in vitro, as well as altered monocyte/macrophage trafficking in vivo.

  19. What Are the Signs and Symptoms of Fanconi Anemia?

    MedlinePlus

    ... hands and feet, pale skin, and chest pain. Bone Marrow Failure When your bone marrow fails, it can't make enough red blood ... spots. In some people who have FA, the bone marrow makes a lot of harmful, immature white blood ...

  20. Unusual Anemias.

    PubMed

    Daughety, Molly Maddock; DeLoughery, Thomas G

    2017-03-01

    Many processes lead to anemia. This review covers anemias that are less commonly encountered in the United States. These anemias include hemoglobin defects like thalassemia, bone marrow failure syndromes like aplastic anemia and pure red cell aplasia, and hemolytic processes such as paroxysmal nocturnal hemoglobinuria. The pathogenesis, diagnostic workup, and treatment of these rare anemias are reviewed.

  1. Microcytic anemia.

    PubMed

    Shine, J W

    1997-05-15

    Because anemia is a condition rather than a disease, an underlying cause must be determined when anemia is identified. Microcytic anemia is a common category of anemia. Iron deficiency anemia is the most common type of microcytic anemia and is also the most common anemia. The clinical presentation of anemia varies according to its severity. Anemias resulting from chronic disease and thalassemia are also relatively common types of microcytic anemia and should be differentiated from iron deficiency to avoid repeated unnecessary trials of iron therapy. Low serum ferritin is the best single laboratory parameter for the diagnosis of iron deficiency. Serum iron, total iron binding capacity and hemoglobin electrophoresis, if necessary, can help differentiate the type of microcytic anemia in patients with normal or elevated levels of serum ferritin. If the evaluation identifies iron deficiency as the type of anemia, the underlying cause must be investigated.

  2. Pernicious Anemia

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Pernicious Anemia? Pernicious anemia (per-NISH-us uh-NEE-me-uh) is ... nervous system working properly. People who have pernicious anemia can't absorb enough vitamin B12 from food. ...

  3. Sundanese Complementation

    ERIC Educational Resources Information Center

    Kurniawan, Eri

    2013-01-01

    The focus of this thesis is the description and analysis of clausal complementation in Sundanese, an Austronesian language spoken in Indonesia. The thesis examined a range of clausal complement types in Sundanese, which consists of (i) "yen/(wi)rehna" "that" complements, (ii) "pikeun" "for" complements,…

  4. Sundanese Complementation

    ERIC Educational Resources Information Center

    Kurniawan, Eri

    2013-01-01

    The focus of this thesis is the description and analysis of clausal complementation in Sundanese, an Austronesian language spoken in Indonesia. The thesis examined a range of clausal complement types in Sundanese, which consists of (i) "yen/(wi)rehna" "that" complements, (ii) "pikeun" "for" complements,…

  5. Warm autoimmune hemolytic anemia.

    PubMed

    Naik, Rakhi

    2015-06-01

    Warm autoimmune hemolytic anemia (AIHA) is defined as the destruction of circulating red blood cells (RBCs) in the setting of anti-RBC autoantibodies that optimally react at 37°C. The pathophysiology of disease involves phagocytosis of autoantibody-coated RBCs in the spleen and complement-mediated hemolysis. Thus far, treatment is aimed at decreasing autoantibody production with immunosuppression or reducing phagocytosis of affected cells in the spleen. The role of complement inhibitors in warm AIHA has not been explored. This article addresses the diagnosis, etiology, and treatment of warm AIHA and highlights the role of complement in disease pathology.

  6. Rifampin-associated tubulointersititial nephritis and Fanconi syndrome presenting as hypokalemic paralysis.

    PubMed

    Min, Hong Ki; Kim, Eun Oh; Lee, Sang Ju; Chang, Yoon Kyung; Suh, Kwang Sun; Yang, Chul Woo; Kim, Suk Young; Hwang, Hyeon Seok

    2013-01-16

    Rifampin is one of the most important drugs in first-line therapies for tuberculosis. The renal toxicity of rifampin has been reported sporadically and acute tubulointerstitial nephritis (ATIN) is a frequent histological finding. We describe for the first time a case of ATIN and Fanconi syndrome presenting as hypokalemic paralysis, associated with the use of rifampin. A 42-year-old man was admitted with sudden-onset lower extremity paralysis and mild renal insufficiency. He had been treated for pulmonary tuberculosis with isoniazid, rifampin, and ethambutol for 2 months. Laboratory tests revealed proteinuria, profound hypokalemia, hyperchloremic metabolic acidosis with a normal anion gap, positive urine anion gap, hypophosphatemia with hyperphosphaturia, hypouricemia with hyperuricosuria, glycosuria with normal serum glucose level, generalized aminoaciduria, and β2-microglobulinuria. A kidney biopsy revealed findings typical of ATIN and focal granular deposits of immunoglubulin A and complement 3 in the glomeruli and tubules. Electron microscopy showed epithelial foot process effacement and electron-dense deposits in the subendothelial and mesangial spaces. Cessation of rifampin resolved the patient's clinical presentation of Fanconi syndrome, and improved his renal function and proteinuria. This case demonstrates that rifampin therapy can be associated with Fanconi syndrome presenting as hypokalemic paralysis, which is a manifestation of ATIN. Kidney function and the markers of proximal tubular injury should be carefully monitored in patients receiving rifampin.

  7. [Tenofovir-associated Fanconi`s syndrome and rickets in a HIV infected girl].

    PubMed

    Zúñiga, Marcela; Galindo, Armando; Galaz, María Isabel; Vivanco, Maritza; Romero, Patricio; Balboa, Paulina; Torrejón, Claudia

    2017-02-01

    Tenofovir (TDF) is an inhibitor of reverse transcriptase nucleotide analogue, although it has good tolerability and high anti-retroviral activity, its effect on the kidney has been a concern. To describe a girl infected with HIV who presented Fanconi syndrome during antiretroviral therapy with TDF. We describe a HIV-1-infected girl, who after 18 months treatment with TDF presented loss of strength and pain of the lower extremities with functional impairment. Laboratory findings were consistent with Fanconi syndrome. Radiographs showed bilateral hip fracture and wrists. Full recovery of Fanconi syndrome was achieved four months after changing antiretroviral therapy. TDF-prescribing physicians must be prepared to detect signs and symptoms of renal dysfunction and immediately consider switching to another antiviral drug.

  8. Neonatal anemia.

    PubMed

    Aher, Sanjay; Malwatkar, Kedar; Kadam, Sandeep

    2008-08-01

    Neonatal anemia and the need for red blood cell (RBC) transfusions are very common in neonatal intensive care units. Neonatal anemia can be due to blood loss, decreased RBC production, or increased destruction of erythrocytes. Physiologic anemia of the newborn and anemia of prematurity are the two most common causes of anemia in neonates. Phlebotomy losses result in much of the anemia seen in extremely low birthweight infants (ELBW). Accepting a lower threshold level for transfusion in ELBW infants can prevent these infants being exposed to multiple donors.

  9. Living with Anemia

    MedlinePlus

    ... Trials Links Related Topics Aplastic Anemia Hemolytic Anemia Iron-Deficiency Anemia Pernicious Anemia Sickle Cell Disease Send a ... Lead poisoning in children has been linked to iron-deficiency anemia . Teenagers also are at risk for anemia, ...

  10. How Is Anemia Diagnosed?

    MedlinePlus

    ... Trials Links Related Topics Aplastic Anemia Hemolytic Anemia Iron-Deficiency Anemia Pernicious Anemia Sickle Cell Disease Send a ... as to the cause of your anemia. In iron-deficiency anemia , for example, red blood cells usually are ...

  11. Complement inhibitors to treat IgM-mediated autoimmune hemolysis

    PubMed Central

    Wouters, Diana; Zeerleder, Sacha

    2015-01-01

    Complement activation in autoimmune hemolytic anemia may exacerbate extravascular hemolysis and may occasionally result in intravascular hemolysis. IgM autoantibodies as characteristically found in cold autoantibody autoimmune hemolytic anemia, in cold agglutinin disease but also in a considerable percentage of patients with warm autoantibodies are very likely to activate complement in vivo. Therapy of IgM-mediated autoimmune hemolytic anemia mainly aims to decrease autoantibody production. However, most of these treatments require time to become effective and will not stop immediate ongoing complement-mediated hemolysis nor prevent hemolysis of transfused red blood cells. Therefore pharmacological inhibition of the complement system might be a suitable approach to halt or at least attenuate ongoing hemolysis and improve the recovery of red blood cell transfusion in autoimmune hemolytic anemia. In recent years, several complement inhibitors have become available in the clinic, some of them with proven efficacy in autoimmune hemolytic anemia. In the present review, we give a short introduction on the pathogenesis of autoimmune hemolytic anemia, followed by an overview on the complement system with a special focus on its regulation. Finally, we will discuss complement inhibitors with regard to their potential efficacy to halt or attenuate hemolysis in complement-mediated autoimmune hemolytic anemia. PMID:26521297

  12. Rheumatoid anemia.

    PubMed

    Masson, Charles

    2011-03-01

    Rheumatoid anemia is a typical example of anemia of chronic disease. It differs from other forms of anemia, such as iron deficiency anemia or iatrogenic anemia. Rheumatoid anemia is normochromic, normocytic or, less often, microcytic, aregenerative, and accompanied with thrombocytosis. Serum transferrin levels are normal or low, transferrin saturation is decreased, serum ferritin levels are normal or high, the soluble transferrin receptor (sTfR) is not increased (a distinguishing feature with iron deficiency anemia), and the sTfR/log ferritin ratio is lower than 1. This review discusses the prevalence and impact of rheumatoid anemia based on a review of the literature. Iron metabolism, absorption, diffusion, storage, and use by the bone marrow are described using published data on transferrin, ferritin, and hepcidin. Hepcidin is now recognized as a key factor in rheumatoid anemia, in conjunction with the cytokine interleukin-6 (IL-6). Hepcidin is a hormone that lowers serum iron levels and regulates iron transport across membranes, preventing iron from exiting the enterocytes, macrophages, and hepatocytes. In addition, hepcidin inhibits intestinal iron absorption and iron release from macrophages and hepatocytes. The action of hepcidin is mediated by binding to the iron exporter ferroportin. Hepcidin expression in the liver is dependent on the protein hemojuvelin. Inflammation leads to increased hepcidin production via IL-6, whereas iron deficiency and factors associated with increased erythropoiesis (hypoxia, bleeding, hemolysis, dyserythropoiesis) suppress the production of hepcidin. Data from oncology studies and the effects of recombinant human IL-6 support a causal link between IL-6 production and the development of anemia in patients with chronic disease. IL-6 diminishes the proportion of nucleated erythroid cells in the bone marrow and lowers the serum iron level, and these abnormalities can be corrected by administering an IL-6 antagonist. IL-6 stimulates

  13. Pernicious anemia

    MedlinePlus

    ... anemia include: Weakened stomach lining (atrophic gastritis) An autoimmune condition in which the body's immune system attacks the actual intrinsic factor protein or the cells in the lining of ...

  14. Hemolytic Anemia

    MedlinePlus

    ... Hemoglobin is an iron-rich protein that carries oxygen from the lungs to the rest of the body. Anemia has three main causes: blood loss, lack of red blood cell production, or high rates of red blood cell destruction. ...

  15. Nutritional anemias.

    PubMed

    Oski, F A

    1979-10-01

    The role of the metals, iron and copper, and the vitamins E, folic acid, and B12 in the genesis of nutritional anemias in infancy have been reviewed. All are preventable. The precise requirements for each of these trace elements and vitamins in the small premature infant remain to be defined. The nonhematologic consequences of these nutritional deficiencies require further study. Anemia may prove to be the least important manifestation of the deficiency states.

  16. Hypocholesterolemia in chronic anemias with increased erythropoietic activity.

    PubMed

    Shalev, Hanna; Kapelushnik, Joseph; Moser, Asher; Knobler, Hilla; Tamary, Hannah

    2007-03-01

    Hypocholesterolemia of unknown etiology has been previously described in various chronic anemias. Few small studies also suggested that those patients have a lower incidence of atherosclerotic events. The aim of our study was to determine the extent of hypocholesterolemia in various types of anemias. We studied 59 patients with chronic anemias associated with high-erythropoietic activity (thalassemia intermedia, congenital dyserythropoietic anemia type I, congenital spherocytosis), 8 patients with low-erythropoietic activity anemias (acquired aplastic anemia, Fanconi anemia, and Diamond Blackfan anemia), and 20 healthy controls. Mean serum cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, hemoglobin, serum ferritin, soluble transferrin receptor (STR), and serum erythropoietin levels were determined in each patient. All patients with chronic anemia and increased erythropoietic activity had hypocholesterolemia, whereas none of those with low erythropoietic activity was hypocholesterolemic. Mean serum cholesterol, HDL cholesterol, and LDL cholesterol levels were found to be significantly lower in the high-erythropoietic activity group (80+/-19 mg/dl; 31+/-10 mg/dl; 35+/-14 mg/dl, respectively) compared with the control group (P<0.001; 0.001; 0.001, respectively) and the low-erythropoietic activity group (P<0.001; 0.001; 0.01, respectively). Significant inverse correlation (R2=0.507) was observed between serum cholesterol and STR levels, which in the absence of iron deficiency reflect bone marrow activity. Taken together, our results imply that hypocholesterolemia accompanies anemias with high-erythropoietic activity. We suggest that the high-erythropoitic activity-associated hypocholesterolemia is due to increased cholesterol requirements by the proliferating erythoid cells. Further studies are needed to elucidate the exact mechanism and the possible clinical consequences of this phenomenon.

  17. What Is Aplastic Anemia?

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Aplastic Anemia? Aplastic anemia (a-PLAS-tik uh-NEE-me-uh) is ... heart, heart failure , infections, and bleeding. Severe aplastic anemia can even cause death. Overview Aplastic anemia is ...

  18. [Fanconi syndrome in a 22-year-old African patient].

    PubMed

    Wetzstein, Morgane; Jauréguy, Maïté; Lanoix, Jean-Philippe; Poulain, Coralie; Berrou, Claire; Renou, Marianne; Cordonnier, Carole; Choukroun, Gabriel

    2014-11-01

    Acquired Fanconi syndrome can occur in patients with monoclonal gammopathy or after exposure to heavy metals or drug agents such as ifosfamide, and some antiretroviral therapies. Fanconi syndrome is characterized by a dysfunctional of the proximal tubular responsible in its complete form for polyuria, hypokalemia, glycosuria, hypophosphatemia and low molecular weight proteinuria. We report the case of a 22-year-old patient hospitalized with an acute renal failure secondary to a tubulo-interstitial nephritis associated with a complete Fanconi syndrome in a context of a poor general condition and fever. We described and analyzed the process leading to the diagnosis. Copyright © 2014 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

  19. Aplastic anemia.

    PubMed

    Usuki, Kensuke

    Treatments of aplastic anemia are comprised of supportive therapy and aplastic anemia-specific therapy aimed at restoring hematopoiesis. Supportive therapies include transfusion, G-CSF, and the administration of iron chelation agents, as well as dealing specifically with individual symptoms. Aplastic anemia-specific treatments given with the aim of achieving hematopoietic recovery include immunosuppressive therapy, allogeneic hematopoietic stem cell transplantation, and anabolic hormone therapy. Although transplantation provides complete recovery of hematopoiesis (cure), there is a risk of death due to transplant-related complications. The most effective immunosuppressive therapy is a combination of anti-thymocyte globulin and cyclosporine. This treatment is also effective against the secondary, drug-induced and hepatitis-associated forms of aplastic anemia. In the management of aplastic anemia, a treatment is selected from among these options depending on the disease severity and the age of the individual case. The thrombopoietin receptor agonist eltrombopag appears to be effective and to provide tri-lineage recovery of hematopoiesis in some cases. Indications for its use are expected to expand in Japan.

  20. Wissler–Fanconi syndrome and related diagnoses: a case report

    PubMed Central

    Albustani, Mustafa Q; Howard, Robert F

    2016-01-01

    Introduction Wissler–Fanconi syndrome is a rare rheumatic syndrome that was first described during the 1940s in Europe. Since then, many papers have been written that cover all aspects of this syndrome, most of which are in French and German language, with only a very few in English (none of them recent). We report here a case that fulfils the criteria for Wissler–Fanconi syndrome. Under the more general descriptive umbrella of Wissler–Fanconi syndrome, our patient also fulfils the Modified Jones criteria, and the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria for rheumatoid arthritis, and was interpreted by other internists and another rheumatologist as fulfilling the Yamaguchi criteria for adult onset Still’s disease. Case presentation A middle-aged female presented to the emergency department with shortness of breath and chest pain associated with fever, polyarthritis, and had a chronic polymorphic rash on the back and lower extremities. Blood analysis showed highly elevated inflammatory markers and rheumatoid factor. After ruling out other possible deferential diagnoses and reviewing the medical literature, the patient was diagnosed with Wissler–Fanconi syndrome. A combination of nonsteroidal anti-inflammatory drugs and steroids achieved complete remission. Conclusion This case report highlights the important differential diagnosis that may be included under the nomenclature of Wissler–Fanconi syndrome (subsepsis hyperergica). Features of Wissler–Fanconi syndrome can be found in a differential diagnosis that includes true sepsis, acute rheumatic fever, rheumatoid arthritis, and adult onset Still’s disease. PMID:27843372

  1. Anemia Due to Excessive Bleeding

    MedlinePlus

    ... Hemolytic Anemia Hemoglobin C, S-C, and E Diseases Iron Deficiency Anemia Sickle Cell Disease Thalassemias Vitamin Deficiency Anemia ( ... Hemolytic Anemia Hemoglobin C, S-C, and E Diseases Iron Deficiency Anemia Sickle Cell Disease Thalassemias Vitamin Deficiency Anemia ...

  2. Gestational anemia.

    PubMed

    Wahed, F; Latif, S A; Nessa, A; Bhuiyan, M R; Hossain, M B; Akther, A; Mahmud, M M

    2010-07-01

    Gestational anemia is a common public health problem in our country. Most anemia during pregnancy results from an increased need for iron as her body is making more blood. Often dietary supplementation does not provide enough iron to meet the extra needs. Also the growing baby takes all the iron it needs from mother, regardless of how much iron is stored in mother's blood. Gestational Anemia contributed significantly to maternal morbidity and mortality, IUGR, preterm delivery and perinatal morbidity and mortality. A high proportion of women in both industrialized and developing countries become anemic during pregnancy. The most important cause of gestational anemia due to iron deficiency, because high iron requirements during pregnancy are not easily fulfilled by dietary intake. Adequate iron stores can help a pregnant women replace lost red blood cells. So, iron supplementation is strongly recommended for all pregnant women in developing countries. Oral iron intake is the treatment of choice and almost all pregnant women can be treated effectively with oral iron preparation during their pregnancy period.

  3. p53 downregulates the Fanconi anaemia DNA repair pathway

    PubMed Central

    Jaber, Sara; Toufektchan, Eléonore; Lejour, Vincent; Bardot, Boris; Toledo, Franck

    2016-01-01

    Germline mutations affecting telomere maintenance or DNA repair may, respectively, cause dyskeratosis congenita or Fanconi anaemia, two clinically related bone marrow failure syndromes. Mice expressing p53Δ31, a mutant p53 lacking the C terminus, model dyskeratosis congenita. Accordingly, the increased p53 activity in p53Δ31/Δ31 fibroblasts correlated with a decreased expression of 4 genes implicated in telomere syndromes. Here we show that these cells exhibit decreased mRNA levels for additional genes contributing to telomere metabolism, but also, surprisingly, for 12 genes mutated in Fanconi anaemia. Furthermore, p53Δ31/Δ31 fibroblasts exhibit a reduced capacity to repair DNA interstrand crosslinks, a typical feature of Fanconi anaemia cells. Importantly, the p53-dependent downregulation of Fanc genes is largely conserved in human cells. Defective DNA repair is known to activate p53, but our results indicate that, conversely, an increased p53 activity may attenuate the Fanconi anaemia DNA repair pathway, defining a positive regulatory feedback loop. PMID:27033104

  4. [Sideroblastic anemias].

    PubMed

    Matthes, T

    2006-01-01

    Sideroblastic anemias are a heterogenous group of disorders characterized by the presence of sideroblasts in the bone marrow aspirate. Current classification schemes distinguish between diseases of the heme synthesis pathway and diseases of other mitochondrial pathways which can either be of primary origin (defects in mitochondrial DNA) or of secondary origin (defects in nuclear DNA). Although several distinct hereditary forms exist, sideroblastic anemias are most frequently acquired diseases and belong to the group of myelodysplastic syndromes with the propensity to develop into overt leukemia. Treatment is mainly supportive (vitamins, blood transfusions, cytokines) and only rarely are bone marrow transplantations performed. The molecular defects of a few hereditary forms have already been elucidated, but the genes involved in the acquired forms are still largely unknown.

  5. Sickle cell anemia - resources

    MedlinePlus

    Resources - sickle cell anemia ... The following organizations are good resources for information on sickle cell anemia : American Sickle Cell Anemia Association -- www.ascaa.org National Heart, Blood, and Lung Institute -- www. ...

  6. Cooley's Anemia Foundation

    MedlinePlus

    ... role in their lives. Welcome to the Cooley's Anemia Foundation Website The Cooley's Anemia Foundation is dedicated to serving people afflicted with ... major form of this genetic blood disease, Cooley's anemia/thalassemia major. Our mission is advancing the treatment ...

  7. Anemia (For Parents)

    MedlinePlus

    ... a drug or toxin. Anemia From Destruction of Red Blood Cells When the body destroys red blood cells (a ... but can affect all races. continue Anemia From Red Blood Cell Loss Blood loss can cause anemia — whether from ...

  8. [Refractory anemias].

    PubMed

    Efira, A; Azerad, M-A

    2013-09-01

    Refractory anemia, also known as myelodysplastic syndromes, forms a group of clonal diseases characterized by cytopenias with mostly rich bone marrow. Preferentially reaching an older population, the prognosis depends on both comorbidities and characteristics of the disease, which have been grouped into a score established in 1997 ("IPSS = International Prognostic Scoring System") and revised in 2012 ("R-IPSS = Revised IPSS"). Overall survival and risk of transformation into acute nonlymphoblastic leukemia can now be estimated fairly accurately. Based on these characteristics, the treatment will be mainly supportive or will use several new molecules: growth factors, lenalidomide, 5-azacitidine, etc. A minority of patients may also benefit from allogeneic BMT or sometimes immunosuppressive therapy.

  9. Ifosfamide-induced Fanconi syndrome with diabetes insipidus.

    PubMed

    Leem, Ah Young; Kim, Han Sang; Yoo, Byung Woo; Kang, Beo Deul; Kim, Min Hwan; Rha, Sun Young; Kim, Hyo Song

    2014-03-01

    Ifosfamide-induced Fanconi syndrome is a rare complication that typically occurs in young patients due to a cumulative dose of ifosfamide > 40-60 g/m(2), a reduction in kidney mass, or concurrent cisplatin treatment. It is usually characterized by severe and fatal progression accompanied by type II proximal renal tubular dysfunction, as evidenced by glycosuria, proteinuria, electrolyte loss, and metabolic acidosis. Diabetes insipidus is also a rare complication of ifosfamide-induced renal disease. We herein describe a case involving a 61-year-old man who developed ifosfamide-induced Fanconi syndrome accompanied by diabetes insipidus only a few days after the first round of chemotherapy. He had no known risk factors. In addition, we briefly review the mechanisms and possible therapeutic options for this condition based on other cases in the literature. Patients who receive ifosfamide must be closely monitored for renal impairment to avoid this rare but fatal complication.

  10. Fainting Fanconi syndrome clarified by proxy: a case report.

    PubMed

    Walsh, Stephen Benedict; Unwin, Robert; Kleta, Robert; Van't Hoff, William; Bass, Paul; Hussain, Khalid; Ellard, Sian; Bockenhauer, Detlef

    2017-07-11

    Rare diseases may elude diagnosis due to unfamiliarity of the treating physicians with the specific disorder. Yet, advances in genetics have tremendously enhanced our ability to establish specific and sometimes surprising diagnoses. We report a case of renal Fanconi syndrome associated with intermittent hypoglycemic episodes, the specific cause for which remained elusive for over 30 years, despite numerous investigations, including three kidney and one liver biopsy. The most recent kidney biopsy showed dysmorphic mitochondria, suggesting a mitochondrial disorder. When her son presented with hypoglycemia in the neonatal period, he underwent routine genetic testing for hyperinsulinemic hypoglycemia, which revealed a specific mutation in HNF4A. Subsequent testing of the mother confirmed the diagnosis also in her. Modern sequencing technologies that test multiple genes simultaneously enable specific diagnoses, even if the underlying disorder was not clinically suspected. The finding of mitochondrial dysmorphology provides a potential clue for the mechanism, by which the identified mutation causes renal Fanconi syndrome.

  11. Ifosfamide-induced Fanconi syndrome with diabetes insipidus

    PubMed Central

    Leem, Ah Young; Kim, Han Sang; Yoo, Byung Woo; Kang, Beo Deul; Kim, Min Hwan; Rha, Sun Young

    2014-01-01

    Ifosfamide-induced Fanconi syndrome is a rare complication that typically occurs in young patients due to a cumulative dose of ifosfamide > 40-60 g/m2, a reduction in kidney mass, or concurrent cisplatin treatment. It is usually characterized by severe and fatal progression accompanied by type II proximal renal tubular dysfunction, as evidenced by glycosuria, proteinuria, electrolyte loss, and metabolic acidosis. Diabetes insipidus is also a rare complication of ifosfamide-induced renal disease. We herein describe a case involving a 61-year-old man who developed ifosfamide-induced Fanconi syndrome accompanied by diabetes insipidus only a few days after the first round of chemotherapy. He had no known risk factors. In addition, we briefly review the mechanisms and possible therapeutic options for this condition based on other cases in the literature. Patients who receive ifosfamide must be closely monitored for renal impairment to avoid this rare but fatal complication. PMID:24648810

  12. [Differential diagnosis of anemias].

    PubMed

    Szerafin, László; Jakó, János

    2005-02-13

    The authors describe the factors influencing of normal hemoglobin level, pathogenetic and morphological classification of anemias and the possibilities to distinguish their different types. They highlight features of iron deficiency anemia and anemia of chronic diseases. They summarise in tables the basis of laboratory diagnosis and possibility of identification of different types of anemias.

  13. Bilineal Acute Leukemia Associated With Fanconi Syndrome: The First Case Report

    PubMed Central

    Miri-Aliabad, Ghasem; Sadat-Hosseini, Maryam; Dorgalaleh, Akbar

    2016-01-01

    Fanconi syndrome is a metabolic disorder involving dysfunction of the renal proximal tubules, resulting in excessive urinary excretion of several metabolites. Various factors may lead to Fanconi syndrome, as it may be a genetic disease with primary or secondary etiologies, or may be acquired. In this study, we report a unique case of Fanconi syndrome with development of a relatively rare acute leukemia, a condition that has not been reported before. The case was an 8-year-old boy with familial occurrence of Fanconi syndrome, presenting with pallor, asthenia, recurrent infections, growth failure, and a variety of biochemical and hematological abnormalities. After physical examination, radiographic studies, and comprehensive laboratory analyses, Fanconi syndrome associated with bilineal acute leukemia, of myeloid and T-lymphoid lineages, was diagnosed. PMID:27617066

  14. Nutritional anemias.

    PubMed

    Hoffbrand, A V; Herbert, V

    1999-10-01

    Folate, vitamin B12, and iron are the subjects of active biochemical and molecular research so that further understanding of their metabolism in health and in a wide variety of Inherited and acquired diseases can be achieved. The roles of folate and vitamin B12 in cardiovascular and neurologic diseases and in neural tube defects (NTDs) will be further explored in the next decade. The effects of prophylactic therapy and of food fortification with the vitamins on these diseases remain to be established. Iron deficiency is a public health problem in all countries and prevention or treatment, particularly in children in developing countries, are major goals. The increased recent understanding of iron metabolism and absorption may clarify the etiology of diseases of iron metabolism and of dietary iron overload. Improved iron chelation therapy for transfusion-dependent patients with refractory anemias will continue to be actively researched over the next decades.

  15. FANCD2-Controlled Chromatin Access of the Fanconi-Associated Nuclease FAN1 Is Crucial for the Recovery of Stalled Replication Forks

    PubMed Central

    Chaudhury, Indrajit; Stroik, Daniel R.

    2014-01-01

    Fanconi anemia (FA) is a cancer predisposition syndrome characterized by cellular hypersensitivity to DNA interstrand cross-links (ICLs). Within the FA pathway, an upstream core complex monoubiquitinates and recruits the FANCD2 protein to ICLs on chromatin. Ensuing DNA repair involves the Fanconi-associated nuclease 1 (FAN1), which interacts selectively with monoubiquitinated FANCD2 (FANCD2Ub) at ICLs. Importantly, FANCD2 has additional independent functions: it binds chromatin and coordinates the restart of aphidicolin (APH)-stalled replication forks in concert with the BLM helicase, while protecting forks from nucleolytic degradation by MRE11. We identified FAN1 as a new crucial replication fork recovery factor. FAN1 joins the BLM-FANCD2 complex following APH-mediated fork stalling in a manner dependent on MRE11 and FANCD2, followed by FAN1 nuclease-mediated fork restart. Surprisingly, APH-induced activation and chromatin recruitment of FAN1 occur independently of the FA core complex or the FAN1 UBZ domain, indicating that the FANCD2Ub isoform is dispensable for functional FANCD2-FAN1 cross talk during stalled fork recovery. In the absence of FANCD2, MRE11 exonuclease-promoted access of FAN1 to stalled forks results in severe FAN1-mediated nucleolytic degradation of nascent DNA strands. Thus, FAN1 nuclease activity at stalled replication forks requires tight regulation: too little inhibits fork restart, whereas too much causes fork degradation. PMID:25135477

  16. FANCD2-controlled chromatin access of the Fanconi-associated nuclease FAN1 is crucial for the recovery of stalled replication forks.

    PubMed

    Chaudhury, Indrajit; Stroik, Daniel R; Sobeck, Alexandra

    2014-11-01

    Fanconi anemia (FA) is a cancer predisposition syndrome characterized by cellular hypersensitivity to DNA interstrand cross-links (ICLs). Within the FA pathway, an upstream core complex monoubiquitinates and recruits the FANCD2 protein to ICLs on chromatin. Ensuing DNA repair involves the Fanconi-associated nuclease 1 (FAN1), which interacts selectively with monoubiquitinated FANCD2 (FANCD2(Ub)) at ICLs. Importantly, FANCD2 has additional independent functions: it binds chromatin and coordinates the restart of aphidicolin (APH)-stalled replication forks in concert with the BLM helicase, while protecting forks from nucleolytic degradation by MRE11. We identified FAN1 as a new crucial replication fork recovery factor. FAN1 joins the BLM-FANCD2 complex following APH-mediated fork stalling in a manner dependent on MRE11 and FANCD2, followed by FAN1 nuclease-mediated fork restart. Surprisingly, APH-induced activation and chromatin recruitment of FAN1 occur independently of the FA core complex or the FAN1 UBZ domain, indicating that the FANCD2(Ub) isoform is dispensable for functional FANCD2-FAN1 cross talk during stalled fork recovery. In the absence of FANCD2, MRE11 exonuclease-promoted access of FAN1 to stalled forks results in severe FAN1-mediated nucleolytic degradation of nascent DNA strands. Thus, FAN1 nuclease activity at stalled replication forks requires tight regulation: too little inhibits fork restart, whereas too much causes fork degradation.

  17. Anemia in pregnancy.

    PubMed

    Horowitz, Kari M; Ingardia, Charles J; Borgida, Adam F

    2013-06-01

    Hemodynamic changes occur in pregnancy to prepare for expected blood loss at delivery. Physiologic anemia occurs in pregnancy because plasma volume increases more quickly than red cell mass. Anemia is most commonly classified as microcytic, normocytic, or macrocytic. Iron deficiency anemia accounts for 75% of all anemias in pregnancy. Oral iron supplementation is the recommended treatment of iron deficiency anemia in pregnancy. Parenteral iron and erythropoietin can also be used in severe or refractory cases. Outcomes and treatments for other forms of inherited and acquired anemias in pregnancy vary by disease, and include nutritional supplementation, corticosteroids, supportive transfusions, and splenectomy.

  18. Born for a Noble Cause?--A Case Study on Fanconi Anemia

    ERIC Educational Resources Information Center

    Elwess, Nancy L.; Butterfield, Savanna R.; Charles, Amanda; DeVeaugh, Maxine C.; Lu, Gloria J.; Shafqat, Hira; Watts, Andrew

    2005-01-01

    The fictional case study presented here is not based on one case, but is actually based on several cases. College students enrolled in a bioethics course for non-majors wrote it. The case entails the thought processes and decision-making involved in order to save one child suffering from a genetic disorder by producing another child, a "designer…

  19. Fanconi anemia D2 protein is an apoptotic target mediated by caspases.

    PubMed

    Park, Su-Jung; Beck, Brian D; Saadatzadeh, M Reza; Haneline, Laura S; Clapp, D Wade; Lee, Suk-Hee

    2011-09-01

    FANCD2, a key factor in the FANC-BRCA1 pathway is monoubiquitinated and targeted to discrete nuclear foci following DNA damage. Since monoubiquitination of FANCD2 is a crucial indicator for cellular response to DNA damage, we monitored the fate of FANCD2 and its monoubiquitination following DNA damage. Disappearance of FANCD2 protein was induced following DNA damage in a dose-dependent manner, which correlated with degradation of BRCA1 and poly-ADP ribose polymerase (PARP), known targets for caspase-mediated apoptosis. Disappearance of FANCD2 was not affected by a proteasome inhibitor but was blocked by a caspase inhibitor. DNA damage-induced disappearance of FANCD2 was also observed in cells lacking FANCA, suggesting that disappearance of FANCD2 does not depend on FANC-BRCA1 pathway and FANCD2 monoubiquitination. In keeping with this, cells treated with TNF-α, an apoptotic stimulus without causing any DNA damage, also induced disappearance of FANCD2 without monoubiquitination. Together, our data suggest that FANCD2 is a target for caspase-mediated apoptotic pathway, which may be an early indicator for apoptotic cell death.

  20. De Novo Chromosome Copy Number Variation in Fanconi Anemia-Associated Hematopoietic Defects

    DTIC Science & Technology

    2012-04-01

    Correction of FA-A, FA-C, and FA-D2 hTERT cells with pLenti6.2/V5-FANCA, -FANCC, and FANCD2 , respectively. Sub-task 1. Selection and expansion of clonal...populations Sub-task 2. Mitomycin C cytotoxicity and clastogenicity assays, assessment of FANCD2 mono- ubiquitination status via immunoblotting and...a restoration of DNA damage-inducible FANCD2 monoubiquitination in these cells, compared with mutant FA-A hTERT cells (Figure 1). In addition, we

  1. Sequential renal and bone marrow transplants in a child with Fanconi anemia.

    PubMed

    Vincent, Carol L; Primack, William A; Hipps, John; Kasow, Kimberly A

    2016-02-01

    FA is an autosomal recessive disorder characterized by small stature and renal abnormalities. FA can lead to progressive bone marrow failure, myelodysplastic syndrome, or acute leukemia. Using a multidisciplinary team approach, we managed a 3-yr-old boy with FA who simultaneously developed renal and hematopoietic failure. Because renal function was insufficient to support the conditioning regimen for HCT, we performed a deceased donor renal transplant in December 2012 prior to HCT with the known risk of graft-versus-graft rejection of the donor kidney. Seven months later he underwent allogeneic HCT. He obtained myeloid engraftment on day +11 and peripheral blood chimerism demonstrated all donor by day +21. He developed asymptomatic CMV reactivation and despite antirejection medications, mild skin graft-versus-host disease. He has maintained excellent renal function and remains transfusion independent with full hematopoietic recovery. He has not experienced any renal rejection episodes nor developed donor-specific antibodies toward his renal donor. Peripheral blood chimerism remains completely HCT donor. He is clinically well, now greater than two and a half yr after renal transplant and two yr after HCT. The continuing close collaboration between the Pediatric Nephrology and Bone Marrow Transplant teams is a major factor in this successful outcome.

  2. Anemia in thyroid diseases.

    PubMed

    Szczepanek-Parulska, Ewelina; Hernik, Aleksandra; Ruchała, Marek

    2017-03-28

    Anemia is a frequent, although often underestimated, clinical condition accompanying thyroid diseases. In spite of the fact that anemia and thyroid dysfunction often occur simultaneously, the causative relationship between these two disorders remains ambiguous. Thyroid hormones stimulate erythrocytes precursors proliferation directly, as well as via erythropoietin production enhancement, whereas iron-deficient anemia negatively influences thyroid hormonal status. Thus, different forms of anemia might emerge in the course of thyroid dysfunction. In fact, normocytic anemia is most common, while macrocytic or microcytic anemia occur less frequently. Anemia in hypothyroidism might result from bone marrow depression, decreased erythropoietin production, comorbid diseases, or concomitant iron, vitamin B12 or folate deficiency. Altered iron metabolism and oxidative stress may contribute to anemia in hyperthyroidism. The risk of anemia in autoimmune thyroid disease (AITD) may be posed by pernicious anemia and atrophic gastritis, celiac disease, autoimmune hemolytic syndrome, or rheumatic disorders. The simultaneous occurrence of anemia and thyroid disease, as well as their close relation, make the diseases an important clinical problem. The aim of the study is to provide a comprehensive review summarizing data on the prevalence, potential mechanisms, and therapy of anemia in the course of thyroid diseases from the clinical and pathogenetic perspective. Thyroid dysfunction and autoimmune thyroid disease should be considered in differential diagnosis of treatment-resistant or refractory anemia, as well as in case of increased red blood cell distribution width (RDW). Of note is that the presence of AITD itself, independently from thyroid hormonal status, might affect hemoglobin level.

  3. Anemia in older persons.

    PubMed

    Bross, Michael H; Soch, Kathleen; Smith-Knuppel, Teresa

    2010-09-01

    Anemia in older persons is commonly overlooked despite mounting evidence that low hemoglobin levels are a significant marker of physiologic decline. Using the World Health Organization definition of anemia (hemoglobin level less than 13 g per dL [130 g per L] in men and less than 12 g per dL [120 g per L] in women), more than 10 percent of persons older than 65 years are anemic. The prevalence increases with age, approaching 50 percent in chronically ill patients living in nursing homes. There is increasing evidence that even mild anemia is associated with increased morbidity and mortality. Anemia warrants evaluation in all older persons, except those at the end of life or who decline interventions. About one third of persons have anemia secondary to a nutritional deficiency, one third have anemia caused by chronic inflammation or chronic kidney disease, and one third have unexplained anemia. Nutritional anemia is effectively treated with vitamin or iron replacement. Iron deficiency anemia often is caused by gastrointestinal bleeding and requires further investigation in most patients. Anemia of chronic inflammation or chronic kidney disease may respond to treatment of the underlying disease and selective use of erythropoiesis-stimulating agents. The treatment of unexplained anemia is difficult, and there is little evidence that treatment decreases morbidity and mortality, or improves quality of life. Occasionally, anemia may be caused by less common but potentially treatable conditions, such as autoimmune hemolytic anemia, malignancy, or myelodysplastic syndrome.

  4. Complement component 4

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003354.htm Complement component 4 To use the sharing features on this page, please enable JavaScript. Complement component 4 is a blood test that measures the ...

  5. Recurrent aphthous ulcers in Fanconi's anaemia: a case report.

    PubMed

    Otan, Feyza; Açikgöz, Gokhan; Sakallioglu, Umur; Ozkan, Burcu

    2004-05-01

    Fanconi's anaemia (FA) is an autosomal recessive disorder that is clinically characterized by aplastic anaemia, congenital malformations of the renal, cardiac, skeletal and skin structures, and an increased predisposition to malignancies. Patients with FA often present with bleeding and infection, which are symptoms related to thrombocytopenia and neutropenia. There are few reports of the oral manifestations of FA. We describe oral aphthous ulcerations in two siblings with FA. There was a rapid improvement and healing of ulcers after blood transfusions and increased haemoglobin levels. This may support the role of severe anaemia in oral ulcerations.

  6. Hypokalemic paralysis secondary to tenofovir induced fanconi syndrome

    PubMed Central

    Ramteke, Vishal V.; Deshpande, Rushi V.; Srivastava, Om; Wagh, Adinath

    2015-01-01

    Tenofovir induced fanconi syndrome (FS) presenting as hypokalemic paralysis is an extremely rare complication in patients on anti-retroviral therapy. We report a 50-year-old male with acquired immunodeficiency syndrome on tenofovir-based anti-retroviral therapy who presented with acute onset quadriparesis. On evaluation, he was found to have hypokalemia with hypophosphatemia, glucosuria and proteinuria suggesting FS. He regained normal power in limbs over next 12 h following correction of hypokalemia. Ours would be the second reported case in India. PMID:26692618

  7. The Anemias of Athletes.

    ERIC Educational Resources Information Center

    Eichner, Edward R.

    1986-01-01

    Diagnosing anemia in athletes is complicated because athletes normally have a pseudoanemia that needs no treatment. Athletes, however, can develop anemia from iron deficiency or footstrike hemolysis, which require diagnosis and treatment. (Author/MT)

  8. [Common anemias in neonatology].

    PubMed

    Humbert, J; Wacker, P

    1999-01-28

    We describe the four most common groups of neonatal anemia and their treatments, with particular emphasis on erythropoietin therapy. The hemolytic anemias include the ABO incompatibility (much more frequent, nowadays, than the Rh incompatibility, which has nearly disappeared following the use of anti-D immunoglobulin in postpartum Rh-negative mothers), hereditary spherocytosis and G-6-PD deficiency. Among hypoplastic anemias, that caused by Parvovirus B19 predominates, by far, over Diamond-Blackfan anemia, alpha-thalassemia and the rare sideroblastic anemias. "Hemorrhagic" anemias occur during twin-to-twin transfusions, or during feto-maternal transfusions. Finally, the multifactorial anemia of prematurity develops principally as a result of the rapid expansion of the blood volume in this group of patients. Erythropoietin therapy, often at doses much higher than those used in the adult, should be seriously considered in most cases of non-hypoplastic neonatal anemias, to minimise maximally the use of transfusions.

  9. The Anemias of Athletes.

    ERIC Educational Resources Information Center

    Eichner, Edward R.

    1986-01-01

    Diagnosing anemia in athletes is complicated because athletes normally have a pseudoanemia that needs no treatment. Athletes, however, can develop anemia from iron deficiency or footstrike hemolysis, which require diagnosis and treatment. (Author/MT)

  10. Anemia - Multiple Languages

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Anemia URL of this page: https://medlineplus.gov/languages/anemia.html Other topics A-Z Expand Section ...

  11. Fanconi anaemia and the repair of Watson and Crick DNA crosslinks.

    PubMed

    Kottemann, Molly C; Smogorzewska, Agata

    2013-01-17

    The function of Fanconi anaemia proteins is to maintain genomic stability. Their main role is in the repair of DNA interstrand crosslinks, which, by covalently binding the Watson and the Crick strands of DNA, impede replication and transcription. Inappropriate repair of interstrand crosslinks causes genomic instability, leading to cancer; conversely, the toxicity of crosslinking agents makes them a powerful chemotherapeutic. Fanconi anaemia proteins can promote stem-cell function, prevent tumorigenesis, stabilize replication forks and inhibit inaccurate repair. Recent advances have identified endogenous aldehydes as possible culprits of DNA damage that may induce the phenotypes seen in patients with Fanconi anaemia.

  12. Transient renal Fanconi syndrome in a Chihuahua exposed to Chinese chicken jerky treats.

    PubMed

    Hooijberg, E H; Furman, E; Leidinger, J; Brandstetter, D; Hochleithner, C; Sewell, A C; Leidinger, E; Giger, U

    2015-01-01

    Transient Fanconi syndrome without azotemia was diagnosed in a dog and was associated with ingestion of Chinese chicken jerky treats. Fanconi syndrome is a proximal renal tubular defect and a diagnosis was made based upon severe glucosuria with normoglycemia, and severe generalized aminoaciduria. The clinical signs of polyuria and polydipsia as well as the massive urinary metabolic abnormalities resolved after jerky treat withdrawal. While frequently seen in North America and Australia, this is the first report of jerky treat induced Fanconi syndrome in continental Europe. Clinicians should be aware of this potential intoxication and be vigilant for a history of jerky treat consumption in a dog with glucosuria.

  13. Myeloma and pernicious anemia.

    PubMed

    Perillie, P E

    1978-01-01

    Four cases of pernicious anemia developing in association with multiple myeloma are described. The description now of 14 cases demonstrating the association of these two disorders suggest a causative relationship. These observations, in addition to the previously well-documented increased coincidence of pernicious anemia and benign monoclonal gammopathy and pernicious anemia and hypoglobulinemia, suggest that screening for vitamine B12 deficiency in patients with gammopathies and for protein abnormalities in patients with pernicious anemia is indicated.

  14. Anemia (For Teens)

    MedlinePlus

    ... don't get enough iron in their diets. Iron Deficiency Anemia Iron deficiency anemia is the most common type of anemia ... when a person's diet is lacking in iron. Iron deficiency — when the body's stores of iron are reduced — ...

  15. Anemia (For Parents)

    MedlinePlus

    ... child may not be able to play contact sports because there's a risk that the spleen could rupture or hemorrhage. Certain forms of anemia (such as sickle cell disease) need other, more specific kinds of care and treatment. How Can I Prevent Iron-Deficiency Anemia in My Kids? Many kinds of anemia ...

  16. Thiamine responsive megaloblastic anemia.

    PubMed

    Mathews, Lulu; Narayanadas, K; Sunil, G

    2009-02-01

    This report describes a female child with thiamine responsive megaloblastic anemia syndrome (Rogers syndrome), presenting with anemia and diabetes mellitus responding to thiamine. She also had retinitis pigmentosa. The anemia improved and blood sugar was controlled with daily oral thiamine. Previously unreported olfactory abnormalities, as described in Wolfram syndrome, were also present in our patient.

  17. [Inherited aplastic anemias].

    PubMed

    Esteves, A C; Freitas, O; Almeida, T; Rosado, L

    2010-08-01

    The inherited aplastic anaemias are a heterogeneous group of disorders characterized by bone marrow failure, frequent association with one or more somatic anomalies and increased risk of cancer. They are rare disorders, usually diagnosed at paediatric age, and have significant premature mortality. The authors report 11 cases of inherited aplastic anaemias, 8 of Fanconi's anaemia and 3 of Dyskeratosis congenita. These cases were diagnosed in the last 14 years in the Dona Estefânia Hospital.

  18. Penicillin-induced immunohemolytic anemia associated with circulating immune complexes.

    PubMed

    Funicella, T; Weinger, R S; Moake, J L; Spruell, M; Rossen, R D

    1977-01-01

    Eleven days after administration of multiple penicillin analogs, a 55-year-old female developed a Coombs-positive hemolytic anemia. The patient's erythrocytes were coated with IgG, complement components (C4/C3) and her serum contained elevated 125I-Clq binding activity (a measure of the presence of immune complexes). Her serum, in the presence of fresh complement and penicillin, induced complement sensitization of normal erythrocytes. Immune complex-mediated complement activation and the haptene type of erythrocyte sensitization accounted for accelerated red blood cell destruction in this patient.

  19. Pregnancy in fanconi anaemia with bone marrow failure: a case report and review of the literature.

    PubMed

    Sorbi, Flavia; Mecacci, Federico; Di Filippo, Alessandro; Fambrini, Massimiliano

    2017-02-03

    Fanconi anaemia is a rare inherited disease characterized by congenital abnormalities, progressive bone marrow failure and predisposition to malignancy. Successful pregnancies in transplanted patients have been reported. In this paper we will describe the pregnancy of a patient with Fanconi anaemia without transplantation. A 34-year-old nulliparous woman with Fanconi anaemia was referred to our institution. Pregnancy was complicated by progressive pancytopenia and two severe infections. C-section was performed at 36 weeks. Both infant and mother are well. Successful pregnancy in a Fanconi anaemia patient with bone marrow failure is possible. The mode of delivery in patients with bone marrow failure should be determined by obstetric indications. The case highlights the safe outcome of the pregnancy with strict clinical and laboratory control by a multidisciplinary team.

  20. [Iron dysregulation and anemias].

    PubMed

    Ikuta, Katsuya

    2015-10-01

    Most iron in the body is utilized as a component of hemoglobin that delivers oxygen to the entire body. Under normal conditions, the iron balance is tightly regulated. However, iron dysregulation does occasionally occur; total iron content reductions cause iron deficiency anemia and overexpression of the iron regulatory peptide hepcidin disturbs iron utilization resulting in anemia of chronic disease. Conversely, the presence of anemia may ultimately lead to iron overload; for example, thalassemia, a common hereditary anemia worldwide, often requires transfusion, but long-term transfusions cause iron accumulation that leads to organ damage and other poor outcomes. On the other hand, there is a possibility that iron overload itself can cause anemia; iron chelation therapy for the post-transfusion iron overload observed in myelodysplastic syndrome or aplastic anemia improves dependency on transfusions in some cases. These observations reflect the extremely close relationship between anemias and iron metabolism.

  1. Complement-targeted therapeutics

    PubMed Central

    Ricklin, Daniel; Lambris, John D

    2010-01-01

    The complement system is a central component of innate immunity and bridges the innate to the adaptive immune response. However, it can also turn its destructive capabilities against host cells and is involved in numerous diseases and pathological conditions. Modulation of the complement system has been recognized as a promising strategy in drug discovery, and a large number of therapeutic modalities have been developed. However, successful marketing of complement-targeted drugs has proved to be more difficult than initially expected, and many strategies have been discontinued. The US Food and Drug Administration’s approval of the first complement-specific drug, an antibody against complement component C5 (eculizumab; Soliris), in March 2007, was a long-awaited breakthrough in the field. Approval of eculizumab validates the complement system as therapeutic target and might facilitate clinical development of other promising drug candidates. PMID:17989689

  2. Fever of unknown origin as the initial manifestation of valproate-induced Fanconi syndrome.

    PubMed

    Nozaki, Fumihito; Kumada, Tomohiro; Kusunoki, Takashi; Fujii, Tatsuya; Murayama, Kei; Ohtake, Akira

    2014-12-01

    Valproate-induced Fanconi syndrome is a rare adverse effect of valproate. Severely disabled patients who require tube feeding are reported to be susceptible to valproate-induced Fanconi syndrome. Although most patients with valproate-induced Fanconi syndrome are asymptomatic and detected incidentally with findings such as hypophosphatemia, hypouricemia, increased urinary β2-microglobulin, and generalized hyperaminoaciduria, clinical symptoms such as bone fracture, fever, tachypnea, and edema have been reported. This 15-year-old, severely disabled, tube-fed, male patient with cytochrome oxidase deficiency had taken valproate for 3 years when he developed fever for 3 weeks. Hypophosphatemia, hypouricemia, hypokalemia, increased urinary β2-microglobulin, and generalized hyperaminoaciduria, as well as hypocarnitinemia, were found, indicating that he had Fanconi syndrome. Valproate was the most likely cause of Fanconi syndrome in this patient. After discontinuation of valproate, the fever resolved immediately, and the laboratory findings normalized. Valproate-induced Fanconi syndrome should be considered when individuals taking valproate develop fever of unknown origin. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. The Global Burden of Anemia.

    PubMed

    Kassebaum, Nicholas J

    2016-04-01

    Anemia is an important cause of health loss. We estimated levels and trends of nonfatal anemia burden for 23 distinct etiologies in 188 countries, 20 age groups, and both sexes from 1990 to 2013. All available population-level anemia data were collected and standardized. We estimated mean hemoglobin, prevalence of anemia by severity, quantitative disability owing to anemia, and underlying etiology for each population using the approach of the Global Burden of Disease, Injuries and Risk Factors 2013 Study. Anemia burden is high. Developing countries account for 89% of all anemia-related disability. Iron-deficiency anemia remains the dominant cause of anemia. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Chromosome fragility in patients with Fanconi anaemia: diagnostic implications and clinical impact.

    PubMed

    Castella, Maria; Pujol, Roser; Callén, Elsa; Ramírez, Maria J; Casado, José A; Talavera, Maria; Ferro, Teresa; Muñoz, Arturo; Sevilla, Julián; Madero, Luis; Cela, Elena; Beléndez, Cristina; de Heredia, Cristina Díaz; Olivé, Teresa; de Toledo, José Sánchez; Badell, Isabel; Estella, Jesús; Dasí, Ángeles; Rodríguez-Villa, Antonia; Gómez, Pedro; Tapia, María; Molinés, Antonio; Figuera, Ángela; Bueren, Juan A; Surrallés, Jordi

    2011-04-01

    Fanconi anaemia (FA) is a rare syndrome characterized by bone marrow failure, malformations and cancer predisposition. Chromosome fragility induced by DNA interstrand crosslink (ICL)-inducing agents such as diepoxybutane (DEB) or mitomycin C (MMC) is the 'gold standard' test for the diagnosis of FA. To study the variability, the diagnostic implications and the clinical impact of chromosome fragility in FA. Data are presented from 198 DEB-induced chromosome fragility tests in patients with and without FA where information on genetic subtype, cell sensitivity to MMC and clinical data were available. This large series allowed quantification of the variability and the level of overlap in ICL sensitivity among patients with FA and the normal population. A new chromosome fragility index is proposed that provides a cut-off diagnostic level to unambiguously distinguish patients with FA, including mosaics, from non-FA individuals. Spontaneous chromosome fragility and its correlation with DEB-induced fragility was also analysed, indicating that although both variables are correlated, 54% of patients with FA do not have spontaneous fragility. The data reveal a correlation between malformations and sensitivity to ICL-inducing agents. This correlation was also statistically significant when the analysis was restricted to patients from the FA-A complementation group. Finally, chromosome fragility does not correlate with the age of onset of haematological disease. This study proposes a new chromosome fragility index and suggests that genome instability during embryo development may be related to malformations in FA, while DEB-induced chromosome breaks in T cells have no prognostic value for the haematological disease.

  5. Acute lymphoblastic leukemia in a child with Fanconi's anaemia.

    PubMed

    Mushtaq, Naureen; Wali, Rabia; Fadoo, Zehra; Saleem, Ali Faisal

    2012-07-01

    Fanconi anaemia (FA) is an autosomal recessive inherited disorder with progressive bone marrow failure, associated congenital malformation and solid and haematological malignancies. Acute myeloid leukemia is the commonest haematological malignancy followed by myelodysplastic syndrome in children with FA. FA transformed into acute lymphoblastic leukemia (ALL) is a rare phenomenon and one of the rarest haematological malignancies associated with this disorder. We are reporting a 13 years old girl with FA and positive chromosomal breakage. She required regular blood product transfusion. She was planned for haematopoietic stem cell transplantation (HSCT) but the sibling-matched donor was found to have chromosomal breaks as well. Later on, her peripheral smear showed blast cell. Bone marrow showed pre-B ALL. She was started on chemotherapy but died shortly due to complications of the treatment. For this rare condition conservative management is indeed essential, however, safe and appropriate chemotherapy regimen is needed.

  6. Targeting complement in therapy.

    PubMed

    Kirschfink, M

    2001-04-01

    With increasing evidence that complement activation significantly contributes to the pathogenesis of a large number of inflammatory diseases, strategies that interfere with its deleterious action have become a major focus in pharmacological research. Endogenous soluble complement inhibitors (C1 inhibitor, recombinant soluble complement receptor 1, antibodies) blocking key proteins of the cascade reaction, neutralizing the action of the complement-derived anaphylatoxin C5a, or interfering with complement receptor 3 (CR3, CD18/11b)-mediated adhesion of inflammatory cells to the vascular endothelium have successfully been tested in various animal models over the past years. Promising results consequently led to clinical trials. Furthermore, incorporation of membrane-bound complement regulators (decay-accelerating factor (CD55), membrane co-factor protein (CD46), CD59) in transgenic animals has provided a major step forward in protecting xenografts from hyperacute rejection. At the same time, the poor contribution of complement to the antitumor response, which is caused by multiple resistance mechanisms that hamper the efficacy of antibody-based tumor therapy, is increasingly recognized and requires pharmacologic intervention. First attempts have now been made to interfere with the resistance mechanisms, thereby improving complement-mediated tumor cell destruction.

  7. Complement in autoimmune diseases.

    PubMed

    Vignesh, Pandiarajan; Rawat, Amit; Sharma, Madhubala; Singh, Surjit

    2017-02-01

    The complement system is an ancient and evolutionary conserved element of the innate immune mechanism. It comprises of more than 20 serum proteins most of which are synthesized in the liver. These proteins are synthesized as inactive precursor proteins which are activated by appropriate stimuli. The activated forms of these proteins act as proteases and cleave other components successively in amplification pathways leading to exponential generation of final effectors. Three major pathways of complement pathways have been described, namely the classical, alternative and lectin pathways which are activated by different stimuli. However, all the 3 pathways converge on Complement C3. Cleavage of C3 and C5 successively leads to the production of the membrane attack complex which is final common effector. Excessive and uncontrolled activation of the complement has been implicated in the host of autoimmune diseases. But the complement has also been bemusedly described as the proverbial "double edged sword". On one hand, complement is the final effector of tissue injury in autoimmune diseases and on the other, deficiencies of some components of the complement can result in autoimmune diseases. Currently available tools such as enzyme based immunoassays for functional assessment of complement pathways, flow cytometry, next generation sequencing and proteomics-based approaches provide an exciting opportunity to study this ancient yet mysterious element of innate immunity.

  8. Anemia, fatigue and aging.

    PubMed

    Balducci, L

    2010-12-01

    Aging is associated with increased incidence and prevalence of both cancer and anemia. Cancer and aging may conspire in making anemia more frequent and more severe. This article reviews the causes and the consequences of anemia in the older individual. The most common causes include chronic inflammation that is a typical manifestation of aging, iron deficiency that may be due to chronic hemorrhage, malabsorption and Helicobacter pylori infection, cobalamin deficiency from malabsorption and renal insufficiency. Other causes of anemia whose prevalence is not well established include myelodysplasia, copper deficiency, hypothyroidism, and sarcopenia. Anemia is associated with increased risk of mortality, functional dependence, dementia, falls, and chemotherapy-related toxicity. When correcting the anemia of older cancer patients one should remember that the erythropoietic stimulating agents (ESA) may stimulate cancer growth and cause thrombosis. These products may be safe when given exclusively to patients receiving chemotherapy and when the hemoglobin levels are maintained below 12 g/dL.

  9. [Fatigue and anemia].

    PubMed

    Ivanova, K; Zeller, A

    2009-12-02

    We herein report on an 80-year old male patient with a history of muscle weakness, fatigue and weight loss since several months. Because of a pathologic synacthen test in combination with decreased levels of ACTH, we diagnosed a secondary chronic adrenal insufficiency. Because of a normochromic, normocytic, and hypo-proliferative anemia, bone marrow puncture was performed, showing an anemia of chronic disease. We initiated hydrocortisone and anemia and patients' symptoms were fully reconstituted.

  10. Anemia of inflammation.

    PubMed

    Nemeth, Elizabeta; Ganz, Tomas

    2014-08-01

    Anemia of inflammation (AI, also called anemia of chronic disease) is a common, typically normocytic, normochromic anemia that is caused by an underlying inflammatory disease. It is diagnosed when serum iron concentrations are low despite adequate iron stores, as evidenced by serum ferritin that is not low. In the setting of inflammation, it may be difficult to differentiate AI from iron deficiency anemia, and the 2 conditions may coexist. Treatment should focus on the underlying disease. Recent advances in molecular understanding of AI are stimulating the development of new pathophysiologically targeted experimental therapies.

  11. Congenital Hemolytic Anemia.

    PubMed

    Haley, Kristina

    2017-03-01

    Red blood cell (RBC) destruction can be secondary to intrinsic disorders of the RBC or to extrinsic causes. In the congenital hemolytic anemias, intrinsic RBC enzyme, RBC membrane, and hemoglobin disorders result in hemolysis. The typical clinical presentation is a patient with pallor, anemia, jaundice, and often splenomegaly. The laboratory features include anemia, hyperbilirubinemia, and reticulocytosis. For some congenital hemolytic anemias, splenectomy is curative. However, in other diseases, avoidance of drugs and toxins is the best therapy. Supportive care with transfusions are also mainstays of therapy. Chronic hemolysis often results in the formation of gallstones, and cholecystectomy is often indicated.

  12. Inborn anemias in mice

    SciTech Connect

    Bernstein, S.E.; Barker, J.E.; Russell, E.S.

    1981-06-01

    hereditary anemias of mice have been the chief objects of investigation. At present under study are four macrocytic anemias, five hemolytic anemias, nonhemolytic microcytic anemia, transitory siderocytic anemia, sex-linked iron-transport anemia, an ..cap alpha..-thalassemia, and a new target-cell anemia. Each of these blood dyscrasias is caused by the action of a unique mutant gene, which determines the structure of different intracellular molecules, and thus controls a different metabolic process. Thus our wide range of different hereditary anemias has considerable potential for uncovering many different aspects of hemopoietic homeostatic mechanisms in the mouse. Each anemia is studied through: (a) characterization of peripheral blood values, (b) determinations of radiosensitivity under a variety of conditions, (c) measurements of iron metabolism and heme synthesis, (d) histological and biochemical study of blood-forming tissue, (e) functional tests of the stem cell component, (f) examination of responses to erythroid stimuli, and (g) transplantation of tissue between individuals of differently affected genotypes.

  13. Metformin-induced hemolytic anemia.

    PubMed

    Kirkiz, Serap; Yarali, Nese; Arman Bilir, Ozlem; Tunc, Bahattin

    2014-01-01

    To report a rare side effect of metformin, an oral antidiabetic drug that is used for the treatment of type 2 diabetes mellitus. A 17-year-old boy was hospitalized for receiving acute lymphoblastic leukemia treatment that was composed of vincristine, L-asparaginase, daunorubicin, and prednisone. Hyperglycemia was determined without any clinical sign and metformin was started for steroid-induced insulin resistance. On the second day of metformin treatment, the patient's hemoglobin level decreased, and a direct Coombs test was positive for immunoglobulin G but negative for complement. An indirect Coombs test was negative. The glucose-6-phosphate dehydrogenase level was within the normal range. Drug-induced hemolytic anemia was suspected and metformin was discontinued. The jaundice gradually disappeared and there was no requirement for red blood cell transfusions. This case showed that physicians should be aware of the potential side effect of metformin although it is infrequent. © 2013 S. Karger AG, Basel.

  14. Who Is at Risk for Anemia?

    MedlinePlus

    ... Trials Links Related Topics Aplastic Anemia Hemolytic Anemia Iron-Deficiency Anemia Pernicious Anemia Sickle Cell Disease Send a ... babies are at risk for anemia because of iron deficiency. At-risk infants include those who are born ...

  15. TMA: beware of complements.

    PubMed

    Ricklin, Daniel; Cines, Douglas B

    2013-09-19

    In this issue of Blood, Jodele and colleagues report that defective complement regulation contributes to the development of thrombotic microangiopathy (TMA) after hematopoietic stem cell transplantation (HSCT) with important implications for diagnosis and management of this severe clinical complication.

  16. Complement in the Brain

    PubMed Central

    Veerhuis, Robert; Nielsen, Henrietta M.; Tenner, Andrea J.

    2011-01-01

    The brain is considered to be an immune privileged site, because the blood-brain barrier limits entry of blood borne cells and proteins into the central nervous system (CNS). As a result, the detection and clearance of invading microorganisms and senescent cells as well as surplus neurotransmitters, aged and glycated proteins, in order to maintain a healthy environment for neuronal and glial cells, is largely confined to the innate immune system. In recent years it has become clear that many factors of innate immunity are expressed throughout the brain. Neuronal and glial cells express Toll like receptors as well as complement receptors, and virtually all complement components can be locally produced in the brain, often in response to injury or developmental cues. However, as inflammatory reactions could interfere with proper functioning of the brain, tight and fine tuned regulatory mechanisms are warranted. In age related diseases, such as Alzheimer’s disease (AD), accumulating amyloid proteins elicit complement activation and a local, chronic inflammatory response that leads to attraction and activation of glial cells that, under such activation conditions, can produce neurotoxic substances, including pro-inflammatory cytokines and oxygen radicals. This process may be exacerbated by a disturbed balance between complement activators and complement regulatory proteins such as occurs in AD, as the local synthesis of these proteins is differentially regulated by pro-inflammatory cytokines. Much knowledge about the role of complement in neurodegenerative diseases has been derived from animal studies with transgenic overexpressing or knockout mice for specific complement factors or receptors. These studies have provided insight into the potential therapeutic use of complement regulators and complement receptor antagonists in chronic neurodegenerative diseases as well as in acute conditions, such as stroke. Interestingly, recent animal studies have also indicated that

  17. Sickle Cell Anemia

    MedlinePlus

    Sickle cell anemia is a disease in which your body produces abnormally shaped red blood cells. The cells are shaped like a crescent or sickle. They don' ... problem causes sickle cell anemia. People with the disease are born with two sickle cell genes, one ...

  18. Vitamin Deficiency Anemia

    MedlinePlus

    ... used to treat cancer can interfere with the metabolism of folate. Vitamin B-12 deficiency anemia risk factors include: Lack of intrinsic factor. Most people with a vitamin B-12 deficiency anemia lack intrinsic factor — a protein secreted by the stomach that is necessary for ...

  19. Fifth Cooley's anemia symposium

    SciTech Connect

    Bank, A.; Anderson, W.F.; Zaino, E.C.

    1985-01-01

    This book discusses the topics presented at the symposium on the subject of 'Thalassemia'. Sickle cell anemia is also briefly discussed. The aspects discussed are chromosomal defects of anemias particularly globin synthesis, and the role of messenger RNA and other chromosomes.

  20. [Hemolytic anemias in adults].

    PubMed

    Müller, A; Zimmermann, R; Krause, S W

    2011-11-01

    The erythrocyte lifespan in haemolytic anemia is shortened while erythropoesis is increased. Important labaratory findings are increased reticulocytes, LDH, indirect bilirubin and a decreased haptoglobin level. The most important diagnostic tool for further work up of hemolytic anemia is the direct antiglobulin test (DAT, Coombs test) to differentiate autoimmune hemolytic anemia (AIHA) from other causes. Another important group are fragmentation syndroms (hemolytic uremic syndrome and thrombotic thrombocytopenic purpura). In these forms of haemolytic anemia fragmented red blood cells can be found in the blood smear together with thrombocytopenia. A severe problem in paroxysmal nocturnal hematuria is the incidence of thrombosis. The following review describes the most important forms of hemolytic anemia in the adult and the diagnostic and therapeutic strategies.

  1. Complement component 3 (C3)

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003539.htm Complement component 3 (C3) To use the sharing features on ... and C4 are the most commonly measured complement components. A complement test may be used to monitor ...

  2. Thiamine responsive megaloblastic anemia syndrome.

    PubMed

    Ganesh, Ramaswamy; Ezhilarasi, S; Vasanthi, Thiruvengadam; Gowrishankar, Kalpana; Rajajee, Sarala

    2009-03-01

    Thiamine responsive megaloblastic anemia syndrome (TRMA) is a clinical triad characterized by thiamine-responsive anemia, diabetes mellitus and sensorineural deafness. We report a 4-year-old girl with TRMA whose anemia improved following administration of thiamine and this case report sensitizes the early diagnosis and treatment with thiamine in children presenting with anemia, diabetes and deafness.

  3. [Tenofovir-associated Fanconi's syndrome and rickets in a HIV infected girl].

    PubMed

    Zúñiga, Marcela; Galindo, Armando; Galaz, María Isabel; Vivanco, Maritza; Romero, Patricio; Balboa, Paulina; Torrejón, Claudia

    2016-09-09

    Tenofovir (TDF) is an inhibitor of reverse transcriptase nucleotide analogue, although it has good tolerability and high anti-retroviral activity, its effect on the kidney has been a concern. To describe a girl infected with HIV who presented Fanconi syndrome during antiretroviral therapy with TDF. We describe a HIV-1-infected girl, who after 18 months treatment with TDF presented loss of strength and pain of the lower extremities with functional impairment. Laboratory findings were consistent with Fanconi syndrome. Radiographs showed bilateral hip fracture and wrists. Full recovery of Fanconi syndrome was achieved four months after changing antiretroviral therapy. TDF-prescribing physicians must be prepared to detect signs and symptoms of renal dysfunction and immediately consider switching to another antiviral drug. Copyright © 2016 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Tenofovir-induced Fanconi syndrome in chronic hepatitis B monoinfected patients that reverted after tenofovir withdrawal.

    PubMed

    Viganò, Mauro; Brocchieri, Alessandra; Spinetti, Angiola; Zaltron, Serena; Mangia, Giampaolo; Facchetti, Floriana; Fugazza, Alessandro; Castelli, Francesco; Colombo, Massimo; Lampertico, Pietro

    2014-12-01

    Tenofovir disoproxil fumarate (TDF) is a nucleotide reverse transcriptase inhibitor widely used to treat patients with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) infection. Despite the excellent safety records of this regimen, a few cases of acute renal failure and Fanconi syndrome have been reported among HIV patients exposed to TDF. In the HBV monoinfection scenario, only two cases of TDF-associated Fanconi syndrome have been reported thus far. Here, we describe two additional patients with chronic hepatitis B (CHB) who developed a TDF-induced Fanconi syndrome that reverted after TDF withdrawal and had viral replication fully suppressed upon switching to entecavir (ETV). Though the overall risk of TDF associated severe renal toxicity in HBV patients appears to be negligible, both glomerular and tubular function should be monitored in patients exposed to TDF, especially when other renal risk factors or a history of previous exposure to adefovir dipivoxil (ADV) are present.

  5. Reduced FANCD2 influences spontaneous SCE and RAD51 foci formation in uveal melanoma and Fanconi anaemia.

    PubMed

    Gravells, P; Hoh, L; Solovieva, S; Patil, A; Dudziec, E; Rennie, I G; Sisley, K; Bryant, H E

    2013-11-14

    Uveal melanoma (UM) is unique among cancers in displaying reduced endogenous levels of sister chromatid exchange (SCE). Here we demonstrate that FANCD2 expression is reduced in UM and that ectopic expression of FANCD2 increased SCE. Similarly, FANCD2-deficient fibroblasts (PD20) derived from Fanconi anaemia patients displayed reduced spontaneous SCE formation relative to their FANCD2-complemented counterparts, suggesting that this observation is not specific to UM. In addition, spontaneous RAD51 foci were reduced in UM and PD20 cells compared with FANCD2-proficient cells. This is consistent with a model where spontaneous SCEs are the end product of endogenous recombination events and implicates FANCD2 in the promotion of recombination-mediated repair of endogenous DNA damage and in SCE formation during normal DNA replication. In both UM and PD20 cells, low SCE was reversed by inhibiting DNA-PKcs (DNA-dependent protein kinase, catalytic subunit). Finally, we demonstrate that both PD20 and UM are sensitive to acetaldehyde, supporting a role for FANCD2 in repair of lesions induced by such endogenous metabolites. Together, these data suggest FANCD2 may promote spontaneous SCE by influencing which double-strand break repair pathway predominates during normal S-phase progression.

  6. Reduced FANCD2 influences spontaneous SCE and RAD51 foci formation in uveal melanoma and Fanconi anaemia

    PubMed Central

    Gravells, P; Hoh, L; Solovieva, S; Patil, A; Dudziec, E; Rennie, I G; Sisley, K; Bryant, H E

    2013-01-01

    Uveal melanoma (UM) is unique among cancers in displaying reduced endogenous levels of sister chromatid exchange (SCE). Here we demonstrate that FANCD2 expression is reduced in UM and that ectopic expression of FANCD2 increased SCE. Similarly, FANCD2-deficient fibroblasts (PD20) derived from Fanconi anaemia patients displayed reduced spontaneous SCE formation relative to their FANCD2-complemented counterparts, suggesting that this observation is not specific to UM. In addition, spontaneous RAD51 foci were reduced in UM and PD20 cells compared with FANCD2-proficient cells. This is consistent with a model where spontaneous SCEs are the end product of endogenous recombination events and implicates FANCD2 in the promotion of recombination-mediated repair of endogenous DNA damage and in SCE formation during normal DNA replication. In both UM and PD20 cells, low SCE was reversed by inhibiting DNA-PKcs (DNA-dependent protein kinase, catalytic subunit). Finally, we demonstrate that both PD20 and UM are sensitive to acetaldehyde, supporting a role for FANCD2 in repair of lesions induced by such endogenous metabolites. Together, these data suggest FANCD2 may promote spontaneous SCE by influencing which double-strand break repair pathway predominates during normal S-phase progression. PMID:23318456

  7. Fanconi's syndrome and nephrogenic diabetes insipidus in an adult treated with ifosfamide.

    PubMed

    Ingemi, Amanda I; Bota, Vasile M; Peguero, Anyeri; Charpentier, Margaret

    2012-01-01

    Fanconi's syndrome is a serious condition characterized by type II proximal renal tubular dysfunction, with urinary loss of glucose, amino acids, phosphate, bicarbonate, and potassium. Ifosfamide-induced Fanconi's syndrome is reported in about 1.4-5% of children being treated for solid tumors, yet only a few cases have been reported in adults. We describe a 54-year-old man who came to the hospital with symptoms of neutropenic fever 4 days after his fourth cycle of ifosfamide and doxorubicin treatment for recurrent sarcoma with metastases to the lung. During admission, he was noted to have severe renal tubular dysfunction; ifosfamide-induced nephrogenic diabetes insipidus and Fanconi's syndrome were suspected. He received supportive therapy that resulted in incomplete resolution of signs and symptoms. The patient was discharged after a 5-day hospital stay when his white blood cell count increased from 0.1-2.5 × 10(3) /mm(3) and his fever had resolved. Use of the Naranjo adverse drug reaction probability scale indicated a probable relationship (score of 7) between the patient's development of diabetes insipidus and Fanconi's syndrome and his use of ifosfamide. This dual diagnosis of diabetes insipidus and Fanconi's syndrome in an adult makes this case unusual, as well as therapeutically challenging. We conducted a review of the existing literature regarding ifosfamide-induced Fanconi's syndrome and describe the proposed mechanisms and therapeutic options. This case suggests that patients treated with ifosfamide should be monitored closely for renal function to identify, and perhaps prevent, these rare adverse events. Preliminary animal models show promise for adding N-acetylcysteine to ifosfamide treatment, but more research is necessary before using this drug as a therapeutic option.

  8. Drug-induced Fanconi syndrome associated with fumaric acid esters treatment for psoriasis: a case series

    PubMed Central

    Balak, Deepak M.W.; Bouwes Bavinck, Jan Nico; de Vries, Aiko P.J.; Hartman, Jenny; Neumann, Hendrik A. Martino; Zietse, Robert; Thio, Hok Bing

    2016-01-01

    Background Fumaric acid esters (FAEs), an oral immunomodulating treatment for psoriasis and multiple sclerosis, have been anecdotally associated with proximal renal tubular dysfunction due to a drug-induced Fanconi syndrome. Few data are available on clinical outcomes of FAE-induced Fanconi syndrome. Methods Descriptive case series with two cases of Fanconi syndrome associated with FAE treatment diagnosed at two Dutch university nephrology departments, three cases reported at the Dutch and German national pharmacovigilance databases and six previously reported cases. Results All 11 cases involved female patients with psoriasis. The median age at the time of onset was 38 years [interquartile range (IQR) 37–46]. Patients received long-term FAEs treatment with a median treatment duration of 60 months (IQR 28–111). Laboratory tests were typically significant for low serum levels of phosphate and uric acid, while urinalysis showed glycosuria and proteinuria. Eight (73%) patients had developed a hypophosphataemic osteomalacia and three (27%) had pathological bone fractures. All patients discontinued FAEs, while four (36%) patients were treated with supplementation of phosphate and/or vitamin D. Five (45%) patients had persisting symptoms despite FAEs discontinuation. Conclusions FAEs treatment can cause drug-induced Fanconi syndrome, but the association has been reported infrequently. Female patients with psoriasis treated long term with FAEs seem to be particularly at risk. Physicians treating patients with FAEs should be vigilant and monitor for the potential occurrence of Fanconi syndrome. Measurement of the urinary albumin:total protein ratio is a suggested screening tool for tubular proteinuria in Fanconi syndrome. PMID:26798466

  9. Evaluation of Macrocytic Anemias.

    PubMed

    Green, Ralph; Dwyre, Denis M

    2015-10-01

    Macrocytic anemia, defined as a mean cell volume (MCV) ≥100 fL in adults, has a narrow differential diagnosis that requires evaluation of the peripheral blood smear as well as additional laboratory testing taken in conjunction with clinical information that includes patient history and physical examination findings. This review is an update on the approach to a patient with macrocytic anemia with attention paid to the differentiation of megaloblastic and non-megaloblastic macrocytic anemias. Critical to the determination of the diagnosis is the judicious use of laboratory testing and the evaluation of those findings in conjunction with the patient medical, surgical, and medication history.

  10. ANEMIA OF CENTRAL ORIGIN

    PubMed Central

    Ishii, Kazusa; Young, Neal S.

    2015-01-01

    Hypoproliferative anemia results from the inability of bone marrow to produce adequate numbers of red blood cells. The list of conditions that cause hypoproliferative anemia is long, starting from common etiologies as iron deficiency to rarer diagnoses of constitutional bone marrow failure syndromes. There is no perfect diagnostic algorithm, and clinical data may not always clearly distinguish “normal” from “abnormal”, yet it is important for practicing clinicians to recognize each condition so that treatment can be initiated promptly. This review describes diagnostic approaches to hypoproliferative anemia, with particular emphasis on bone marrow failure syndromes. PMID:26404444

  11. Acquired Fanconi syndrome in four cats treated with chlorambucil.

    PubMed

    Reinert, Natalie C; Feldman, David G

    2016-12-01

    Fanconi syndrome (FS) is well described in humans and dogs, but has not been reported in cats. This case series describes four cats with acquired FS. On the basis of clinical signs and intestinal biopsies, all cats were initially diagnosed with alimentary lymphoma or inflammatory bowel disease. Treatment with chlorambucil and corticosteroids was started at standard doses, based on published protocols. Within 2-26 months of the start of treatment, glucosuria, despite normoglycemia, was identified incidentally on routine biochemical screening; FS was diagnosed with urine metabolic assays, confirming aminoaciduria and glucosuria in all four cases. Neither polyuria nor polydipsia were noted in any case, and only 1/4 cats had any clinical signs at the time of diagnosis. Partial or complete resolution of FS was seen in 3/4 cases within 3 months of discontinuing chlorambucil therapy. This is the first case series to document acquired FS in the cat, and the first to suggest a possible association between chlorambucil and acquired FS. Cats treated with chlorambucil should be monitored for the development of glucosuria, and discontinuation of chlorambucil should be considered if FS is identified. Further study into the association between chlorambucil and acquired FS in cats is warranted. © The Author(s) 2015.

  12. Unraveling the Fanconi anaemia-DNA repair connection through DNA helicase and translocase activities

    SciTech Connect

    Thompson, L H

    2005-08-16

    How the Fanconi anaemia (FA) chromosome stability pathway functions to cope with interstrand crosslinks and other DNA lesions has been elusive, even after FANCD1 proved to be BRCA2, a partner of Rad51 in homologous recombination. The identification and characterization of two new Fanconi proteins having helicase motifs, FANCM and FANCJ/BRIP1/BACH1, implicates the FANC nuclear core complex as a participant in recognizing or processing damaged DNA, and the BRIP1 helicase as acting independently of this complex.

  13. Hepcidin and sports anemia.

    PubMed

    Kong, Wei-Na; Gao, Guofen; Chang, Yan-Zhong

    2014-01-01

    Iron is an important mineral element used by the body in a variety of metabolic and physiologic processes. These processes are highly active when the body is undergoing physical exercises. Prevalence of exercise-induced iron deficiency anemia (also known as sports anemia) is notably high in athletic populations, particularly those with heavy training loads. The pathogenesis of sports anemia is closely related to disorders of iron metabolism, and a more comprehensive understanding of the mechanism of iron metabolism in the course of physical exercises could expand ways of treatment and prevention of sports anemia. In recent years, there have been remarkable research advances regarding the molecular mechanisms underlying changes of iron metabolism in response to physical exercises. This review has covered these advances, including effects of exercise on duodenum iron absorption, serum iron status, iron distribution in organs, erythropoiesis, and hepcidin's function and its regulation. New methods for the treatment of exercise-induced iron deficiency are also discussed.

  14. Types of Hemolytic Anemia

    MedlinePlus

    ... Chinese, Filipino, Mediterranean, or African origin or descent. Hereditary Spherocytosis In this condition, a defect in the ... hemolytic anemia among people of Northern European descent. Hereditary Elliptocytosis (Ovalocytosis) Like hereditary spherocytosis, this condition also ...

  15. What Causes Anemia?

    MedlinePlus

    ... to cause anemia. Lack of Red Blood Cell Production Both acquired and inherited conditions and factors can ... damage the red blood cells' ability to carry oxygen. If the bone marrow is damaged, it can' ...

  16. Iron-Deficiency Anemia

    MedlinePlus Videos and Cool Tools

    ... Search Form Search the NHLBI, use the drop down list to select: the entire site, the Health ... Topics Anemia Blood Tests Blood Transfusion Restless Legs Syndrome Send a link to NHLBI to someone by ...

  17. Anemia and heart failure.

    PubMed

    O'Meara, Eileen; Murphy, Clare; McMurray, John J V

    2004-12-01

    Over the past few years, anemia has emerged as a powerful independent predictor of adverse outcomes in chronic heart failure (CHF). It affects up to 50% of patients with CHF, depending on the definition of anemia used and on the population studied. Even small reductions in hemoglobin are associated with worse outcome. However, the causes of anemia in CHF remain unclear, although impairment of renal function and inflammatory cytokines are proposed mechanisms. Both may act through impairment of the synthesis or action of erythropoietin. Preliminary studies have demonstrated improvement in symptoms, exercise tolerance, quality of life, and reductions in hospitalizations when patients with severe CHF were treated with erythropoietin. The benefits and the potential risks of such therapies will be further addressed in upcoming larger randomized trials. The recent interest in anemia reflects a new perspective in heart failure therapy, focusing on non-cardiovascular comorbidities.

  18. Outline of Hungarian Complementation.

    ERIC Educational Resources Information Center

    Szamosi, Michael

    This study presents a preliminary analysis of Hungarian complement constructions and the syntactic operations needed to account for them. The expository framework (and the implicit framework of the research itself) is based upon that of Rosenbaum (1967). The aim of the paper is to arrive at a rough picture of the kinds of structures and syntactic…

  19. Verbal Complementizers in Arabic

    ERIC Educational Resources Information Center

    Ahmed, Hossam Eldin Ibrahim

    2015-01-01

    A class of Modern Standard Arabic complementizers known as "'?inna' and its sisters" demonstrate unique case and word order restrictions. While CPs in Arabic allow both Subject-Verb (SV) and Verb-Subject (VS) word order and their subjects show nominative morphology, CPs introduced by "?inna" ban a verb from directly following…

  20. Management of renal anemia.

    PubMed

    Peco-Antic, Amira

    2005-01-01

    Normochromic normocytic anemia is common in children with chronic renal failure (CRF) when their glomerular filtration rate is below 35 ml/min/1.73 m2 BSA, but it may develop earlier in some forms of renal disease. An inadequate erythropoiesis due to insufficient erythropoietin synthesis in the kidneys is the main cause of renal anemia. Other reasons include reduced red blood cell lifespan, chronic blood loss, iron deficiency, inhibitors of erythropoiesis, and malnutrition. The presence of anemia contributes to many of the symptoms of uremia, including decreased appetite, decreased energy, poor cardiac function, and poor school performance. Therefore, correction of anemia dramatically improves the life of the child with CRF. Presently, the goal of anemia management is to maintain hematocrit concentrations at 33% to 36% and a hemoglobin concentration of at least 11 g/L. This can be accomplished by intravenous or subcutaneous administration of recombinant erythropoietin (rHuEPO, 100-300 U/kg/week) and iron preparations. If adequate iron stores cannot be maintained with oral therapy (2-3, max 6 mg/kg/day), intravenous iron should be administered. In order to optimize anemia management in children with CRF, future research should be concentrated on the normalization of hemoglobin early in the course of CRF, and the long-term effects on the child's development.

  1. [Heart failure and anemia].

    PubMed

    Reda, S; Motloch, L J; Hoppe, U C

    2013-09-01

    Chronic heart failure has an age-dependent prevalence of 2% and is therefore one of the most frequent diseases in western societies. A reduced hemoglobin concentration according to the definition of the World Health Organization is a common comorbidity affecting more than half of all heart failure patients. Elderly patients, patients suffering from renal impairment and women are more likely to develop anemia but a definitive etiology of anemia is only identified in the minority of cases. Anemia is associated with a poor clinical status and a greater risk of hospitalization and is a predictive factor for increased mortality. The incidence of anemia appears to increase with a poorer functional class. Intravenous iron therapy improves the exercise capacity in patients with systolic heart failure and iron deficiency and is currently being recommended for patients with persistent symptoms despite optimal medical and device therapy. However, erythropoietin-stimulating agents as a treatment for anemia in chronic heart failure have failed to improve clinical outcome in a large randomized trial. In patients with heart failure but with maintained ejection fraction, anemia is also associated with a poor prognosis. Specific therapeutic recommendations for these patients are still not available.

  2. How Is Iron-Deficiency Anemia Treated?

    MedlinePlus

    ... page from the NHLBI on Twitter. How Is Iron-Deficiency Anemia Treated? Treatment for iron-deficiency anemia will ... cases, surgery may be advised. Treatments for Severe Iron-Deficiency Anemia Blood Transfusion If your iron-deficiency anemia ...

  3. Special Education: Aplastic Anemia.

    PubMed

    Teramura; Mizoguchi

    1996-01-01

    WHAT IS HYPOPLASTIC ANEMIA? Aplastic anemia is a hematological disease characterized by pancytopenia and bone marrow hypoplasia. Acquired cases of aplastic anemia are almost all idiopathic and arise from unknown causes. Other cases of aplastic anemia are secondary and are caused by radiation, chemicals or viruses. PATHOPHYSIOLOGY: Aplastic anemia is manifested as a marked reduction in the number of pluripotent hematopoietic stem cells, but why this occurs is still uncertain. Some of the proposed causes include abnormalities of the hematopoietic stem cells, abnormalities in the hematopoietic microenvironment, and immunologically mediated damage to the hematopoietic stem cells (Figure 1). ABNORMALTIES OF THE HEMATOPOIETIC STEM CELLS: Patients with aplastic anemia, and long-term survivors in particular, are at increased risk of developing paroxysmal nocturnal hemoglobinuria (PNH), myelodysplastic syndrome (MDS), or acute myelocytic leukemia. This suggests that, in at least some of these patients, the hematopoietic stem cells themselves are abnormal. It also suggests that in some of these patients the blood cells are clonal (that is, all the blood cells are derived from a single pluripotent stem cell). In short, what these findings imply is that aplastic anemia may be caused by the emergence of an abnormal clone. Clonal hematopoiesis, however, can also be considered nothing more than a consequence. In other words, it is possible that hematopoiesis in this kind of patient is performed by a lone pluripotent stem cell that somehow managed to survive eradication. No definitive interpretation of clonal hematopoiesis has been agreed upon, and it is still a topic for future research. ABNORMAL HEMATOPOIETIC MICROENVIRONMENT: The presence of stromal cells, which form the microenvironment of bone marrow, is very important in hematopoiesis. Hematopoietic stem cells proliferate and differentiate either by adhering to stromal cells or by being stimulated by the various

  4. Complements do not lie.

    PubMed

    Robert, Stefanie Christina; Forbes, Suzanne Helen; Soleimanian, Surusch; Hadley, Julia S

    2011-12-13

    A 74-year-old patient presented with constitutional symptoms and was found to have acute kidney injury. He was known to have a prosthetic aortic valve. He was febrile with splenomegaly and vasculitic lesions on both hands. Nephritic screen revealed strongly positive cytoplasmic-antineutrophil cytoplasmic antibodies (c-ANCA). Differential diagnosis thus included a small vessel vasculitis or infective endocarditis. Transoesophageal echocardiography demonstrated no vegetations and serial blood cultures were negative. Immunosuppression for presumed granulomatosis with polyangiitis (Wegeners granulomatosis) was therefore instituted. The patient deteriorated, requiring multi-organ support. Renal biopsy showed a proliferative glomerulopathy and complements were low. Atypical screen for culture negative endocarditis revealed a strongly positive IgG-antibody titre against Bartonella henselae. Immunosuppression was discontinued and treatment for chronic Bartonellosis commenced. The patient made a remarkable recovery. His renal function quickly returned to normal, and ANCA titres and complements normalised. He was discharged home after completing a 6 week course of antibiotic therapy.

  5. Complements do not lie

    PubMed Central

    Robert, Stefanie Christina; Forbes, Suzanne Helen; Soleimanian, Surusch; Hadley, Julia S

    2011-01-01

    A 74-year-old patient presented with constitutional symptoms and was found to have acute kidney injury. He was known to have a prosthetic aortic valve. He was febrile with splenomegaly and vasculitic lesions on both hands. Nephritic screen revealed strongly positive cytoplasmic-antineutrophil cytoplasmic antibodies (c-ANCA). Differential diagnosis thus included a small vessel vasculitis or infective endocarditis. Transoesophageal echocardiography demonstrated no vegetations and serial blood cultures were negative. Immunosuppression for presumed granulomatosis with polyangiitis (Wegeners granulomatosis) was therefore instituted. The patient deteriorated, requiring multi-organ support. Renal biopsy showed a proliferative glomerulopathy and complements were low. Atypical screen for culture negative endocarditis revealed a strongly positive IgG-antibody titre against Bartonella henselae. Immunosuppression was discontinued and treatment for chronic Bartonellosis commenced. The patient made a remarkable recovery. His renal function quickly returned to normal, and ANCA titres and complements normalised. He was discharged home after completing a 6 week course of antibiotic therapy. PMID:22674942

  6. Complements do not lie.

    PubMed

    Robert, Stefanie Christina; Forbes, Suzanne Helen; Soleimanian, Surusch; Hadley, Julia S

    2011-12-01

    A 74-year-old patient presented with constitutional symptoms and was found to have acute kidney injury. He was known to have a prosthetic aortic valve. He was febrile with splenomegaly and vasculitic lesions on both hands. Nephritic screen revealed strongly positive cytoplasmic-antineutrophil cytoplasmic antibodies (c-ANCA). Differential diagnosis thus included a small vessel vasculitis or infective endocarditis. Transoesophageal echocardiography demonstrated no vegetations and serial blood cultures were negative. Immunosuppression for presumed granulomatosis with polyangiitis (Wegeners granulomatosis) was therefore instituted. The patient deteriorated, requiring multi-organ support. Renal biopsy showed a proliferative glomerulopathy and complements were low. Atypical screen for culture negative endocarditis revealed a strongly positive IgG-antibody titre against Bartonella henselae. Immunosuppression was discontinued and treatment for chronic Bartonellosis commenced. The patient made a remarkable recovery. His renal function quickly returned to normal, and ANCA titres and complements normalised. He was discharged home after completing a 6 week course of antibiotic therapy.

  7. IXO: The Instrument Complement

    NASA Astrophysics Data System (ADS)

    Nousek, John A.; IWG, IXO

    2009-01-01

    The International X-ray Observatory (IXO) has recently been created as a mission concept by a joint team of NASA, ESA and JAXA scientists, based on the previous Constellation-X and XEUS concepts. Definition of the IXO instruments is still under evolution, but the core instrument complement will include a Wide Field X-ray Imager, an X-ray Calorimeter / Narrow Field X-ray Imager, and an X-ray Grating Spectrometer. Other, modest additional instruments (such as a hard X-ray capability, a polarimeter, and a high time resolution detector) will also be considered. We present the current status of the IXO instrument complement and offer the opportunity for discussion of ideas relevant to the IXO mission concept process.

  8. Association of aplastic anaemia and Fanconi's disease with HLA-DRB1 alleles.

    PubMed

    Yari, F; Sobhani, M; Vaziri, M Z; Bagheri, N; Sabaghi, F; Talebian, A

    2008-12-01

    One of the most fascinating areas of research within the field of histocompatibility at present time concerns an observation that a major human histocompatibility system, human leucocyte antigen (HLA), is deeply involved in the development of a great number of diseases. Major histocompatibility complex is the most polymorphic system in the genome of different species. Recognition of HLA alleles could be useful in transplantation and disease studies. Genetic construct of HLA DRB1 was studied in Iranian normal populations and patients with aplastic anaemia and Fanconi's disease. DNA was extracted from the whole blood of 466 normal, 35 aplastic anaemia and 10 Fanconi's individuals. Then DRB1 gene polymorphism was studied by polymerase chain reaction-sequence-specific primer method. The HLA DRB1 gene analysis showed increase of DRB1*07 in aplastic anaemia patients compared to normal population (P = 0.02). According to this study, the frequency of DRB1*07 in normal individuals was 8.3, and in aplastic anaemia patients, 15.7%. Additionally, the frequency of DRB1*04 in normal, aplastic anaemia and Fanconi's individuals was 10, 5.7 and 20%, respectively. Our results of investigation showed correlation between some HLA alleles with the studied diseases. We reported the frequency of various DR types in aplastic and Fanconi's patients. This study could imply the possible role of HLA-DRB1*07 in the incidence of aplastic anaemia. Moreover, the frequency of DRB1*04, DRB1*03 and DRB1*15 alleles showed intermediate correlation with Fanconi's anaemia.

  9. Aplastic Anemia and Myelodysplastic Syndromes

    MedlinePlus

    ... of agranulocytosis and aplastic anemia. American Journal of Hematology. 2006;81(1):65–67. [3] Sekeres M. ... KA, Leporrier M, Rinder HM. Marrow-Damage Anemia: Hematology in Clinical Practice. 5th ed. China: The McGraw- ...

  10. Could Anemia Cause Hearing Loss?

    MedlinePlus

    ... fullstory_162793.html Could Anemia Cause Hearing Loss? Iron deficiency might keep ear cells from getting oxygen ... HealthDay News) -- Hearing loss may be linked to iron deficiency anemia -- a combination of low levels of ...

  11. [Autoimmune hemolytic anemia in children].

    PubMed

    Becheur, M; Bouslama, B; Slama, H; Toumi, N E H

    2015-01-01

    Autoimmune hemolytic anemia is a rare condition in children which differs from the adult form. It is defined by immune-mediated destruction of red blood cells caused by autoantibodies. Characteristics of the autoantibodies are responsible for the various clinical entities. Classifications of autoimmune hemolytic anemia include warm autoimmune hemolytic anemia, cold autoimmune hemolytic anemia, and paroxysmal cold hemoglobinuria. For each classification, this review discusses the epidemiology, etiology, clinical presentation, laboratory evaluation, and treatment options.

  12. Mechanisms of anemia in CKD.

    PubMed

    Babitt, Jodie L; Lin, Herbert Y

    2012-10-01

    Anemia is a common feature of CKD associated with poor outcomes. The current management of patients with anemia in CKD is controversial, with recent clinical trials demonstrating increased morbidity and mortality related to erythropoiesis stimulating agents. Here, we examine recent insights into the molecular mechanisms underlying anemia of CKD. These insights hold promise for the development of new diagnostic tests and therapies that directly target the pathophysiologic processes underlying this form of anemia.

  13. Sjögren's syndrome complicated with Fanconi syndrome and Hashimoto's thyroiditis: Case report and literature review.

    PubMed

    Shi, Mingmin; Chen, Lei

    2016-06-01

    We report a unique case of Sjögren's syndrome complicated with Fanconi syndrome and Hashimoto's thyroiditis in a 53-year-old Chinese woman, initially found to have proteinuria, fatigue and multiple old costal fractures. Distal tubular dysfunction is the most common renal damage in Sjögren's syndrome, while Fanconi syndrome (which is caused by proximal tubular dysfunction) and Hypothyroidism are rare complications of Sjögren's syndrome.

  14. Nutritional anemias and the elderly.

    PubMed

    Carmel, Ralph

    2008-10-01

    Nutritional anemias are important because they are easily reversed and because their underlying causes, most often unrelated to dietary intake, require individualized assessment. Iron-deficiency anemia (IDA) usually results from iron losses accompanying chronic bleeding, including loss to intestinal parasites, or from gastric disorders or malabsorption in the elderly. Cobalamin-deficiency anemia, the only nutritional anemia with predilection for the elderly, nearly always stems from failure of intrinsic factor (IF)-related absorption. Folate-deficiency anemia, the only nutritional anemia usually caused by poor intake, has nearly disappeared in countries that fortify food with folic acid. Copper-deficiency anemia, which usually results from malabsorptive disorders or from medical or nutritional interventions that provide inadequate copper or excess zinc, is uncommon but increasingly recognized. The prevalences of nutritional anemias, which are not always distinguished from non-anemic deficiency, are uncertain. The mean corpuscular volume (MCV) provides an essential diagnostic tool leading to judicious matching of relevant biochemical changes with relevant anemia. Nutritional anemias usually feature abnormal MCV, whereas the predominant anemias in the aged, especially the anemias of chronic disease/chronic inflammation (ACD/ACI), of renal failure, and of unknown causes, are typically normocytic.

  15. Megaloblastic anemia in North Africa.

    PubMed

    Maktouf, Chokri; Bchir, Attouma; Louzir, Hechmi; Mdhaffer, Moez; Elloumi, Moez; Ben Abid, Hela; Meddeb, Balkis; Makni, Faiza; Laatiri, Adnene; Soussi, Taoufik; Hafsia, Aicha; Dellagi, Koussay

    2006-07-01

    We prospectively studied 478 patients with megaloblastic anemia living in Tunisia. Overall, 98% of patients had vitamin B12 deficiency. Pernicious anemia accounted for most of these cases, and median age at presentation was 45 years. Megaloblastic anemia occurred in 19 subjects under 15 years of age, and of these, nine had the Immerslund-Graesbeck syndrome.

  16. How Is Aplastic Anemia Diagnosed?

    MedlinePlus

    ... from the NHLBI on Twitter. How Is Aplastic Anemia Diagnosed? Your doctor will diagnose aplastic anemia based on your medical and family histories, a ... your primary care doctor thinks you have aplastic anemia, he or she may refer you to a ...

  17. [Microcytic and hypochromic anemias].

    PubMed

    Chrobák, L

    2001-03-01

    In the majority of cases, microcytosis is the result of impaired hemoglobin synthesis. Disorders of iron metabolism and protoporphyrin and heme synthesis, as well as impaired globin synthesis, lead to defective hemoglobin production and to the generation of microcytosis and microcytic anemia. Iron deficiency anemie, anemia of chronic diseases, thalassemias, congenital sideroblastic anemias and homozygous HbE disease are the main representatives of microcytosis and microcytic anemias. Serum iron, total iron binding capacity, transferrin saturation, serum ferritin, serum transferrin receptor, transferrin receptor-ferritin index, and zinc-protoporhyrin concentration in erythrocytes are tests used for assessment of iron deficiency. The convention laboratory test for diagnosing iron deficiency is the measurement of serum ferritin. The most precise method for evaluating body iron stores is the examination for iron on aspirated bone marrow or marrow biopsy. Increased content of Hb A2 over 3.5% is diagnostic for beta-thalassemia. Presence of ringed sideroblasts is characteristic of sideroblastic anemias. Hemoglobin electrophoresis is required for the diagnosis of hemoglobinopathy E. The optimal therapeutic regimen in iron deficiency anemia used in this country is to administer 100 mg of elemental iron twice daily separately from meals. Ferrous sulphate (Ferronat Retard tbl. or Sorbifer Dulures tbl.) which are slow-releasing iron formulations are preferred because of their low cost, high bioavailability and low side-effects. Parenteral iron therapy is justified only in patients who cannot absorb iron, who have blood losses that exceed the maximal absorptive capacity of their intestinal tract or who are totally intolerant of oral iron. However, parenteral iron therapy may be associated with serious and even fatal side-effects.

  18. Iron Deficiency Anemia.

    PubMed

    DeLoughery, Thomas G

    2017-03-01

    Iron deficiency is one of the most common causes of anemia. The 2 main etiologies of iron deficiency are blood loss due to menstrual periods and blood loss due to gastrointestinal bleeding. Beyond anemia, lack of iron has protean manifestations, including fatigue, hair loss, and restless legs. The most efficient test for the diagnosis of iron deficiency is the serum ferritin. Iron replacement can be done orally, or in patients in whom oral iron is not effective or contraindicated, with intravenous iron. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. [Equine Infectious Anemia (EIA)].

    PubMed

    Kaiser, A; Meier, H P; Straub, R; Gerber, V

    2009-04-01

    Equine Infectious Anemia (EIA) is a reportable, eradicable epizootic disease caused by the equine lentivirus of the retrovirus family which affects equids only and occurs worldwide. The virus is transmitted by blood, mainly by sanguivorous insects. The main symptoms of the disease are pyrexia, apathy, loss of body condition and weight, anemia, edema and petechia. However, infected horses can also be inapparent carriers without any overt signs. The disease is diagnosed by serological tests like the Coggins test and ELISA tests. Presently, Switzerland is offi cially free from EIA. However, Switzerland is permanently at risk of introducing the virus as cases of EIA have recently been reported in different European countries.

  20. Resveratrol improves ifosfamide-induced Fanconi syndrome in rats

    SciTech Connect

    Sehirli, Ozer; Sakarcan, Abdullah; Velioglu-Oguenc, Ayliz; Cetinel, Sule; Gedik, Nursal; Yegen, Berrak C.; Sener, Goeksel . E-mail: gsener@marmara.edu.tr

    2007-07-01

    Regarding the mechanisms of ifosfamide (IFO)-induced urinary toxicity, several hypotheses have been put forward, among which oxidative stress and depletion of glutathione are suggested. This investigation elucidates the role of free radicals in IFO-induced toxicity and the protection by resveratrol, a natural phytoalexin. Wistar albino rats were injected intraperioneally with saline (0.9% NaCl; control), saline + resveratrol (RVT; 10 mg/kg/day), ifosfamide (IFO; 50 mg/kg/day) or IFO + RVT for 5 days. Urine was collected for 24 h during the 5th day, and at the 120th h after the first injections, animals were killed by decapitation and trunk blood was collected. Lactate dehydrogenase (LDH) activity, total antioxidant capacity (AOC) and pro-inflammatory cytokines TNF-{alpha}, IL-{beta} and IL-6 were assayed in plasma samples. Kidney and bladder tissues were obtained for biochemical and histological analysis. Formation of reactive oxygen species in the tissue samples was monitored by using chemiluminescence (CL) technique with luminol and lucigenin probes. The results demonstrated that IFO induced a Fanconi syndrome characterized by increased urinary sodium, phosphate, glucose and protein, along with increased serum creatinine and urea levels. On the other hand, RVT markedly ameliorated the severity of renal dysfunction induced by IFO. Furthermore IFO caused a significant decrease in plasma AOC, which was accompanied with significant increases in the levels of the pro-inflammatory mediators and LDH activity, while RVT treatment reversed all these biochemical indices. In the saline-treated IFO group, glutathione levels were decreased significantly, while the malondialdehyde levels, myeloperoxidase activity and collagen content were increased in both tissues, which were in parallel with the increases in CL values. In the RVT-treated IFO group, all of these oxidant responses were prevented significantly. Our results suggest that IFO causes oxidative damage in the renal

  1. Anemia: Evaluation and Diagnostic Tests.

    PubMed

    Cascio, Michael J; DeLoughery, Thomas G

    2017-03-01

    Anemia is among the most common medical problems and clinical and laboratory evaluation need to be approached logically. The complete blood count with red cell indices offers clues to diagnosis. Many anemias have characteristic red cell morphology. The reticulocyte count serves as a useful screen for hemolysis or blood loss. Testing for specific causes of the anemia is performed. Occasionally, examination of the bone marrow is required for diagnosis. Molecular testing is increasingly being use to aid the diagnostic process. This article reviews diagnostic tests for anemia and suggests a rational approach to determining the etiology of a patient's anemia.

  2. Living with Aplastic Anemia

    MedlinePlus

    ... Content: NEXT >> Featured Video Clinical Trials for Rare Blood Diseases (Neal Young, M.D.) 05/17/2012 In ... in the lives of people who have rare blood and bone marrow diseases, such as aplastic anemia. // Non Object? Updated: August ...

  3. Hepcidin and sports anemia

    PubMed Central

    2014-01-01

    Iron is an important mineral element used by the body in a variety of metabolic and physiologic processes. These processes are highly active when the body is undergoing physical exercises. Prevalence of exercise-induced iron deficiency anemia (also known as sports anemia) is notably high in athletic populations, particularly those with heavy training loads. The pathogenesis of sports anemia is closely related to disorders of iron metabolism, and a more comprehensive understanding of the mechanism of iron metabolism in the course of physical exercises could expand ways of treatment and prevention of sports anemia. In recent years, there have been remarkable research advances regarding the molecular mechanisms underlying changes of iron metabolism in response to physical exercises. This review has covered these advances, including effects of exercise on duodenum iron absorption, serum iron status, iron distribution in organs, erythropoiesis, and hepcidin’s function and its regulation. New methods for the treatment of exercise-induced iron deficiency are also discussed. PMID:24731443

  4. Autoimmune Hemolytic Anemia.

    PubMed

    Liebman, Howard A; Weitz, Ilene C

    2017-03-01

    Autoimmune hemolytic anemia is an acquired autoimmune disorder resulting in the production of antibodies directed against red blood cell antigens causing shortened erythrocyte survival. The disorders can present as a primary disorder (idiopathic) or secondary to other autoimmune disorders, malignancies, or infections. Treatment involves immune modulation with corticosteroids and other agents.

  5. Anemia and School Participation

    ERIC Educational Resources Information Center

    Bobonis, Gustavo J.; Miguel, Edward; Puri-Sharma, Charu

    2006-01-01

    Anemia is among the most widespread health problems for children in developing countries. This paper evaluates the impact of a randomized health intervention delivering iron supplementation and deworming drugs to Indian preschool children. At baseline, 69 percent were anemic and 30 percent had intestinal worm infections. Weight increased among…

  6. Anemia of inflammation.

    PubMed

    Roy, Cindy N

    2010-01-01

    Inflammation arising from various etiologies, including infection, autoimmune disorders, chronic diseases, and aging, can promote anemia. The anemia of inflammation (AI) is most often normocytic and normochromic and is usually mild. Characteristic changes in systemic iron handling, erythrocyte production, and erythrocyte life span all contribute to AI. The preferred treatment is directed at the underlying disease. However, when the inflammatory insult is intractable, or the cause has not been diagnosed, there are limited options for treatment of AI. Because anemia is a comorbid condition that is associated with poor outcomes in various chronic disease states, understanding its pathogenesis and developing new tools for its treatment should remain a priority. Hepcidin antimicrobial peptide has taken center stage in recent years as a potent modulator of iron availability. As the technology for quantitative hepcidin analysis improves, hepcidin's role in various disease states is also being revealed. Recent insights concerning the regulatory pathways that modify hepcidin expression have identified novel targets for drug development. As the field advances with such therapeutics, the analysis of the impact of normalized hemoglobin on disease outcomes will confirm whether anemia is a reversible independent contributor to the morbidity and mortality associated with inflammatory diseases.

  7. Sickle Cell Anemia Bibliography.

    ERIC Educational Resources Information Center

    Christy, Steven C.

    Presents sources for the acquisition of medical, social, psychological, educational, and practical knowledge of sickle cell anemia. The materials listed are designed to help parents, educators, and public service workers. Materials include journal articles, films, brochures, slides, and fact sheets. The usual bibliographic information is given.…

  8. Anemia and School Participation

    ERIC Educational Resources Information Center

    Bobonis, Gustavo J.; Miguel, Edward; Puri-Sharma, Charu

    2006-01-01

    Anemia is among the most widespread health problems for children in developing countries. This paper evaluates the impact of a randomized health intervention delivering iron supplementation and deworming drugs to Indian preschool children. At baseline, 69 percent were anemic and 30 percent had intestinal worm infections. Weight increased among…

  9. Sickle Cell Anemia Bibliography.

    ERIC Educational Resources Information Center

    Christy, Steven C.

    Presents sources for the acquisition of medical, social, psychological, educational, and practical knowledge of sickle cell anemia. The materials listed are designed to help parents, educators, and public service workers. Materials include journal articles, films, brochures, slides, and fact sheets. The usual bibliographic information is given.…

  10. How to approach chronic anemia.

    PubMed

    Koury, Mark J; Rhodes, Melissa

    2012-01-01

    We present herein an approach to diagnosing the cause of chronic anemia based on a patient's history and complete blood cell count (CBC). Four patterns that are encountered frequently in CBCs associated with chronic anemias are considered: (1) anemia with abnormal platelet and/or leukocyte counts, (2) anemia with increased reticulocyte counts, (3) life-long history of chronic anemia, and (4) anemia with inappropriately low reticulocytes. The pathophysiologic bases for some chronic anemias with low reticulocyte production are reviewed in terms of the bone marrow (BM) events that reduce normal rates of erythropoiesis. These events include: apoptosis of erythroid progenitor and precursor cells by intrinsic and extrinsic factors, development of macrocytosis when erythroblast DNA replication is impaired, and development of microcytosis due to heme-regulated eIF2α kinase inhibition of protein synthesis in iron-deficient or thalassemic erythroblasts.

  11. Complementing Gender Analysis Methods.

    PubMed

    Kumar, Anant

    2016-01-01

    The existing gender analysis frameworks start with a premise that men and women are equal and should be treated equally. These frameworks give emphasis on equal distribution of resources between men and women and believe that this will bring equality which is not always true. Despite equal distribution of resources, women tend to suffer and experience discrimination in many areas of their lives such as the power to control resources within social relationships, and the need for emotional security and reproductive rights within interpersonal relationships. These frameworks believe that patriarchy as an institution plays an important role in women's oppression, exploitation, and it is a barrier in their empowerment and rights. Thus, some think that by ensuring equal distribution of resources and empowering women economically, institutions like patriarchy can be challenged. These frameworks are based on proposed equality principle which puts men and women in competing roles. Thus, the real equality will never be achieved. Contrary to the existing gender analysis frameworks, the Complementing Gender Analysis framework proposed by the author provides a new approach toward gender analysis which not only recognizes the role of economic empowerment and equal distribution of resources but suggests to incorporate the concept and role of social capital, equity, and doing gender in gender analysis which is based on perceived equity principle, putting men and women in complementing roles that may lead to equality. In this article the author reviews the mainstream gender theories in development from the viewpoint of the complementary roles of gender. This alternative view is argued based on existing literature and an anecdote of observations made by the author. While criticizing the equality theory, the author offers equity theory in resolving the gender conflict by using the concept of social and psychological capital.

  12. [IgG kappa myeloma with Fanconi's syndrome and crystalline inclusions. Immunohistochemical and ultrastructural study].

    PubMed

    Schillinger, F; Hopfner, C; Montagnac, R; Milcent, T

    1993-04-17

    An IgG kappa light-chain myeloma, remarkable for the presence of inclusions in plasmocytes and proximal renal tubular cells, was discovered during investigations for renal failure associated with partial Fanconi's syndrome. An immunohistochemical study showed that the crystalline inclusions were positive for IgG and kappa light-chain in plasmocytes and exclusively for kappa light-chain in the renal tubular cells. An ultrastructural study showed that the inclusions were localized in lysosomes and had a 55 A periodicity. This case is similar to the forty odd myelomas or light-chain diseases reported in the literature and revealed by Fanconi's syndrome. Their prognosis is good, with a slow progression towards late renal failure. In our patient the preference of lesions for proximal tubular cells, the site of protein catabolism, was particular since in myelomas they are usually located in the distal tubular cells.

  13. Pathologic Femoral Neck Fracture Due to Fanconi Syndrome Induced by Adefovir Dipivoxil Therapy for Hepatitis B

    PubMed Central

    Lee, Yoon-Suk; Kim, Byung-Kook; Lee, Ho-Jae

    2016-01-01

    In Fanconi syndrome, hypophosphatemic osteomalacia is caused by proximal renal tubule dysfunction which leads to impaired reabsorption of amino acids, glucose, urate, and phosphate. We present a rare case of a 43-year-old Korean male who was found to have insufficiency stress fracture of the femoral neck secondary to osteomalacia due to Fanconi syndrome. He had been receiving low-dose adefovir dipivoxil (ADV, 10 mg/day) for the treatment of chronic hepatitis B virus infection for 7 years and he subsequently developed severe hypophosphatemia and proximal renal tubule dysfunction. The incomplete femoral neck fracture was fixed with multiple cannulated screws to prevent further displacement of the initial fracture. After cessation of ADV and correction of hypophosphatemia with oral phosphorus supplementation, the patient's clinical symptoms, such as bone pain, muscle weakness, and laboratory findings improved. PMID:27247753

  14. Acquired Fanconi syndrome in a dog exposed to jerky treats in Japan

    PubMed Central

    IGASE, Masaya; BABA, Kenji; SHIMOKAWA MIYAMA, Takako; NOGUCHI, Shunsuke; MIZUNO, Takuya; OKUDA, Masaru

    2015-01-01

    A 6-year-old spayed female Jack Russell Terrier presented with a 1-month history of lethargy, anorexia, vomiting and weight loss. The dog was fed beef and chicken jerky treats daily in addition to a commercial diet. Laboratory tests revealed azotemia, hypokalemia, hyperchloremia, metabolic acidosis and glucosuria with normoglycemia. Urine amino acid analysis showed significant amino acid loss into the urine. Thus, Fanconi syndrome was diagnosed, and based on the case history and extensive diagnostic testing, excessive consumption of jerky treats was strongly suspected as the cause. Glucosuria resolved 7 days after the withdrawal of jerky treats and fluid therapy. Aminoaciduria was substantially, but not completely, improved 3 months after diagnosis. Mild azotemia remained, suggesting chronic renal disease. To the best of our knowledge, this is the first reported case of Fanconi syndrome following the consumption of jerky treats in Japan. PMID:26062568

  15. Successful treatment of proximal renal tubular acidosis and Fanconi syndrome with vitamin D replacement.

    PubMed

    Ali, Syed Ahsan; Tariq, Muhammad

    2016-01-01

    Proximal renal tubular acidosis (RTA), also known as Type II RTA, is characterized by a defect in the ability to reabsorb bicarbonate (HCO 3 ) in the proximal tubule. It is usually associated with generalized dysfunction of the proximal tubule as part of Fanconi syndrome. Very few case reports in the literature support Vitamin D deficiency as a cause of proximal RTA. We present a case of a young female who presented with proximal RTA and Fanconi syndrome and excellently responded to Vitamin D replacement. Thus, work-up for the etiology of proximal RTA should include Vitamin D levels since replacement of this vitamin in those who are deficient can lead to cure of such patients.

  16. Complement inhibition in cancer therapy.

    PubMed

    Pio, Ruben; Ajona, Daniel; Lambris, John D

    2013-02-01

    For decades, complement has been recognized as an effector arm of the immune system that contributes to the destruction of tumor cells. In fact, many therapeutic strategies have been proposed that are based on the intensification of complement-mediated responses against tumors. However, recent studies have challenged this paradigm by demonstrating a tumor-promoting role for complement. Cancer cells seem to be able to establish a convenient balance between complement activation and inhibition, taking advantage of complement initiation without suffering its deleterious effects. Complement activation may support chronic inflammation, promote an immunosuppressive microenvironment, induce angiogenesis, and activate cancer-related signaling pathways. In this context, inhibition of complement activation would be a therapeutic option for treating cancer. This concept is relatively new and deserves closer attention. In this article, we summarize the mechanisms of complement activation on cancer cells, the cancer-promoting effect of complement initiation, and the rationale behind the use of complement inhibition as a therapeutic strategy against cancer.

  17. Significance of bone-marrow scintigraphy in aplastic anemia: concise communication. [/sup 99m/Tc-sulfur colloid; /sup 111/In-transferrin

    SciTech Connect

    Najean, Y.; Le Danvic, M.; Le Mercier, N.; Pecking, A.; Colonna, P.; Rain, J.D.

    1980-03-01

    Tc-99m colloid and In-111 transferrin were used in a semiquantitative scintigraphic study of bone-marrow activity in 76 patients with aplastic anemia, the majority of which were severe cases. The results are compared with other known prognostic parameters and with a predictive index formulated from a prior multiparametric analysis performed in 352 cases. In 47 cases parallel abnormality of Tc and In uptakes was noted and was well correlated with other prognostic factors. Indium uptake is apparently a good indicator of the severity of aplasia; extension of active erythroid tissue, demonstrated with this method, is correlated with prognosis. In nine cases, excessive in uptake is explained by dyserythropoiesis associated with granulo- and thrombocytopenia (Fanconi's anemia in most cases). In 20 of our patients, TcSC uptake was excessive compared with that of In and with other prognostic factors. Statistically, this phenomenon carries an unfavorable prognosis but its physiological meaning remains to be defined.

  18. Anemia in inflammatory bowel disease.

    PubMed

    Giannini, S; Martes, C

    2006-09-01

    Anemia is a frequent extraenteric complication of inflammatory bowel disease (IBD, Crohn's disease and ulcerative colitis). A systematic review of the literature shows that the overall prevalence of anemia ranges from 8.8% to 73.7% but differs whether in a setting of Crohn's disease or ulcerative colitis. A disabling complication of IBD, anemia worsens the patient's general condition and quality of life, and increases hospitalization rates. Different factors, including vitamin B12 and folic acid deficiency, bone marrow suppression secondary to drug therapy, autoimmune hemolytic anemia and the coexistence of myelodysplastic syndromes are involved in the pathogenesis of anemia in IBD. The main types of anemia in IBD are iron deficiency anemia and anemia accompanying chronic diseases. Correct diagnostic definition of anemia is a fundamental step in guiding the choice of therapeutic options, since the co-presence of different pathogenetic factors may sometimes require a more complex treatment plan. A review of anemia in IBD, its pathogenetic features, epidemiology, diagnosis and therapy based on evidence from recent studies is the focus of this article.

  19. Hypophosphataemic osteomalacia due to de Toni-Debre-Fanconi syndrome in a 19-year old girl.

    PubMed

    Tsilchorozidou, Tasoula; Yovos, John G

    2005-01-01

    Osteomalacia associated with adult onset Fanconi syndrome is thought to result from hypophosphataemia due to renal phosphate loss and relative 1,25-dihydroxyvitamin D3 deficiency. In this disorder, the impaired renal phosphate uptake occurs as part of a generalized tubular defect in association with other features such as bicarbonuria, glycosuria and aminoaciduria. Fanconi syndrome is either hereditary--juvenile form--or is associated with various acquired or heritable diseases. In adults, the disease is similar to the juvenile form, but osteomalacia is a prominent feature. We report a sporadic, adult onset, hypophosphataemia in a 19-year old female patient who presented after puberty complaining of bone and joint pain and difficulty in walking following a minor fall. Radiological examination revealed numerous bilateral fractures of the ribs and pelvis while biochemical investigations showed combination of high phosphate clearance, low serum bicarbonate, glycosuria and glycinuria. Known causes of acquired renal tubular dysfunction were ruled out. The patient was diagnosed as having idiopathic Fanconi syndrome and started on vitamin D3 (Alfacalcidol 1 mg/day) and oral phosphorus (Joulie Solution, 1.5 g/day), which led to resolution of symptoms and an increase in serum phosphate (from 0,54 to 0,71 mmol/l) within few months following the initiation of therapy. However, radiological re-examination showed no signs of fracture healing.

  20. [Anemia in the elderly].

    PubMed

    Maerevoet, M; Sattar, L; Bron, D; Gulbis, B; Pepersack, T

    2014-09-01

    Anaemia is a problem that affects almost 10% over 65 years and 20% over 85 years. There is no physiological anaemia in the elderly. Any anaemia expresses the existence of a pathological process, regardless of its severity. Anaemia in the elderly is always associated with a poor prognosis that is in terms of mortality, morbidity and risk of fragility. The diagnostic approach to anemia in the elderly is the same as in younger individual. There are many causes of anaemia; anaemia balance is a complex diagnostic process. Most anaemias are due to a deficiency, chronic inflammation or comorbidity. However, in the elderly, the etiology of anaemia is often multifactorial. In a number of cases remain unexplained anaemia. In a number of cases, anemia remain unexplained. Treatment of anaemia is the treatment of the cause, but specific therapeutic aspects to the elderly should be considered, as among other martial substitution or use of erythropoietin (EPO).

  1. Nanomedicine and the complement paradigm.

    PubMed

    Moghimi, S Moein; Farhangrazi, Z Shadi

    2013-05-01

    The role of complement in idiosyncratic reactions to nanopharmaceutical infusion is receiving increasing attention. We discuss this in relation to nanopharmaceutical development and the possible use of complement inhibitors to prevent related adverse reactions. We further call on initiation of genetic association studies to unravel the genetic basis of nanomedicine infusion-related adverse responses, since most of the polymorphic genes in the genome belong to the immune system. In this paper, idiosyncratic reactions based on complement activation are discussed in the context of newly available complement inhibitors. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Complement System in Lung Disease

    PubMed Central

    Pandya, Pankita H.

    2014-01-01

    In addition to its established contribution to innate immunity, recent studies have suggested novel roles for the complement system in the development of various lung diseases. Several studies have demonstrated that complement may serve as a key link between innate and adaptive immunity in a variety of pulmonary conditions. However, the specific contributions of complement to lung diseases based on innate and adaptive immunity are just beginning to emerge. Elucidating the role of complement-mediated immune regulation in these diseases will help to identify new targets for therapeutic interventions. PMID:24901241

  3. Extra-Renal Manifestations of Complement-Mediated Thrombotic Microangiopathies

    PubMed Central

    Hofer, Johannes; Rosales, Alejandra; Fischer, Caroline; Giner, Thomas

    2014-01-01

    Thrombotic microangiopathies (TMA) are rare but severe disorders, characterized by endothelial cell activation and thrombus formation leading to hemolytic anemia, thrombocytopenia, and organ failure. Complement over activation in combination with defects in its regulation is described in an increasing number of TMA and if primary for the disease denominated as atypical hemolytic-uremic syndrome. Although TMA predominantly affects the renal microvasculature, extra-renal manifestations are observed in 20% of patients including involvement of the central nerve system, cardiovascular system, lungs, skin, skeletal muscle, and gastrointestinal tract. Prompt diagnosis and treatment initiation are therefore crucial for the prognosis of disease acute phase and the long-term outcome. This review summarizes the available evidence on extra-renal TMA manifestations and discusses the role of acute and chronic complement activation by highlighting its complex interaction with inflammation, coagulation, and endothelial homeostasis. PMID:25250305

  4. [Anemia: guidelines comparison].

    PubMed

    Del Vecchio, Lucia

    2009-01-01

    The development of recombinant human erythropoietin and its introduction into the market in the late 1980s has significantly improved the quality of life of patients with chronic kidney disease (CKD) and reduced the need for blood transfusions. Starting from a cautious target, a progressive increase in the recommended hemoglobin levels has been observed over the years, in parallel with an increase in the obtained levels. This trend has gone together with the publication of findings of observational studies showing a relationship between the increase in hemoglobin levels and a reduction in the mortality risk, with the conduction of clinical trials testing the effects of complete anemia correction, and with the compilation of guidelines on anemia control in CKD patients by scientific societies and organizations. In the last two years, evidence of a possible increase in the mortality risk in those patients who were randomized to high hemoglobin levels has resulted in a decrease in the upper limit of the recommended Hb target to be obtained with erythropoietin stimulating agents (ESA), and consequently in a narrowing of the target range. Comparison of guidelines on anemia control in CKD patients is an interesting starting point to discuss single recommendations, strengthen their importance, or suggest new topics of research to fill up important gaps in knowledge.

  5. [Nutritional anemias in elderly patients].

    PubMed

    Serraj, Khalid; Federici, Laure; Kaltenbach, Georges; Andrès, Emmanuel

    2008-09-01

    Nutritional deficiencies cause one third of the cases of anemia in the elderly. The urgency of anemia management in elderly patients depends on tolerance and repercussions, rather than only on the hemoglobin level. Iron, vitamin B12 and folate are the most common deficiencies, and their levels should be tested. Chronic gastrointestinal bleeding is the principal cause of iron-deficiency anemia. Management is based on supplementation combined with effective etiological treatment.

  6. Anemia in severe acute malnutrition.

    PubMed

    Thakur, Neha; Chandra, Jagdish; Pemde, Harish; Singh, Varinder

    2014-04-01

    India has the highest prevalence of severe acute malnutrition (SAM). Severe anemia is one of the comorbidities responsible for increased mortality in severely malnourished children, yet it has not received the attention it should. The aim of the present study was to determine the prevalence and type of anemia and to evaluate the possible etiologies for severe anemia, in these children. A cross-sectional study of patients with SAM in a tertiary care hospital in northern India over a period of 12 mo from Sept. 1, 2010 to Aug. 31, 2011 was conducted. We observed the prevalence of severe anemia (hemoglobin < 7 g/dL), morphologic type of anemia, number of patients requiring blood transfusion, hematologic profile of mothers, nature of feeding, duration of exclusive breastfeeding, and the demographic profile of these patients. Included in the study were 131 cases of SAM. The age group varied between 6 and to 59 mo. Of patients with SAM, 67.3% had severe anemia; 13.8% had moderate anemia. Of these patients, 25% required packed red blood cell transfusion. The most common type of anemia was microcytic (38.6%) followed by megaloblastic (30.5%). A high incidence of severe anemia in SAM with a large proportion (25%) requiring blood transfusion is a pointer toward nutritional anemia being a very common comorbidity of SAM requiring hospital admission. Because megaloblastic anemia closely followed microcytic anemia, supplementation with vitamin B12 in addition to iron and folic acid would be recommended. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Iron-Deficiency Anemia (For Parents)

    MedlinePlus

    ... Blood Breastfeeding FAQs: How Much and How Often Vegan Food Guide Vegetarianism Anemia Word! Anemia Vitamins About ... Vegetarian Blood Coping With Common Period Problems Anemia Vegan Food Guide Vitamins and Minerals Contact Us Print ...

  8. Iron Deficiency Anemia in Pregnancy.

    PubMed

    Breymann, Christian

    2015-10-01

    Anemia is a common problem in obstetrics and perinatal care. Any hemoglobin below 10.5 g/dL can be regarded as true anemia regardless of gestational age. Reasons for anemia in pregnancy are mainly nutritional deficiencies, parasitic and bacterial diseases, and inborn red blood cell disorders such as thalassemias. The main cause of anemia in obstetrics is iron deficiency, which has a worldwide prevalence between estimated 20%-80% and consists of a primarily female population. Stages of iron deficiency are depletion of iron stores, iron-deficient erythropoiesis without anemia, and iron deficiency anemia, the most pronounced form of iron deficiency. Pregnancy anemia can be aggravated by various conditions such as uterine or placental bleedings, gastrointestinal bleedings, and peripartum blood loss. In addition to the general consequences of anemia, there are specific risks during pregnancy for the mother and the fetus such as intrauterine growth retardation, prematurity, feto-placental miss ratio, and higher risk for peripartum blood transfusion. Besides the importance of prophylaxis of iron deficiency, the main therapy options for the treatment of pregnancy anemia are oral iron and intravenous iron preparations.

  9. [Iron deficiency anemia and anemia of chronic disorders].

    PubMed

    Metzgeroth, G; Hastka, J

    2015-09-01

    Hypochromic-microcytic anemias are characterized by a hemoglobin deficiency of the erythrocytes. The main reason for the insufficient hemoglobin synthesis is, with exception of thalassemia and a few other rare conditions, primarily a disorder of iron metabolism. Differential diagnostic considerations are focused on iron deficiency anemia, with approximately 80% the most common form of anemia worldwide. Iron deficiency anemia shows a particularly high prevalence in developing countries, but is also in industrialized Western countries the most common cause of anemia. Infants, toddlers, premenopausal or pregnant women, and elderly people are at particularly high risk of iron deficiency anemia. The most important differential diagnosis for iron deficiency anemia is the anemia of chronic disorders (ACD). This anemia is caused by a disturbance of iron utilization (functional iron deficiency), in which iron absorption and iron release, as a nonspecific defense mechanism, is blocked to restrict iron availability for the inflammatory process but also withhold iron from the erythropoiesis. ACD is not rare, but plays a significant role in hospitalized patients and in the elderly. The differentiation between ACD and iron deficiency anemia is highly important from a clinical point of view, due to different types of further management. The cause for iron deficiency should be clarified in each case, whereas the etiology for ACD is often obvious. The standard treatment of iron deficiency anemia is oral iron supplementation. Intravenous iron application is reserved for problem patients. The best treatment for ACD is the elimination of the underlying chronic disorder. In case of persistent ACD, red blood cell transfusions, erythropoietin, and intravenous iron are used therapeutically.

  10. [Diagnosis and treatment of hemolytic anemia].

    PubMed

    Kamesaki, Toyomi

    2015-10-01

    Hemolytic anemia is defined as anemia due to a reduction of the RBC lifespan to less than the normal range of approximately 120 days. Patients with anemia and jaundice are often suspected to have hemolysis. Herein, different causes of hemolysis and the diagnostic algorithm are reviewed. Currently, there is no generic treatment for hemolytic anemia. Appropriate management of a patient with hemolytic anemia requires determination of the underlying cause. Treatments for the different causes of hemolytic anemia are also reviewed.

  11. Post-Babesiosis Warm Autoimmune Hemolytic Anemia.

    PubMed

    Woolley, Ann E; Montgomery, Mary W; Savage, William J; Achebe, Maureen O; Dunford, Kathleen; Villeda, Sarah; Maguire, James H; Marty, Francisco M

    2017-03-09

    Background Babesiosis, a tickborne zoonotic disease caused by intraerythrocytic protozoa of the genus babesia, is characterized by nonimmune hemolytic anemia that resolves with antimicrobial treatment and clearance of parasitemia. The development of warm-antibody autoimmune hemolytic anemia (also known as warm autoimmune hemolytic anemia [WAHA]) in patients with babesiosis has not previously been well described. Methods After the observation of sporadic cases of WAHA that occurred after treatment of patients for babesiosis, we conducted a retrospective cohort study of all the patients with babesiosis who were cared for at our center from January 2009 through June 2016. Data on covariates of interest were extracted from the medical records, including any hematologic complications that occurred within 3 months after the diagnosis and treatment of babesiosis. Results A total of 86 patients received a diagnosis of babesiosis during the 7.5-year study period; 18 of these patients were asplenic. WAHA developed in 6 patients 2 to 4 weeks after the diagnosis of babesiosis, by which time all the patients had had clinical and laboratory responses to antimicrobial treatment of babesiosis, including clearance of Babesia microti parasitemia. All 6 patients were asplenic (P<0.001) and had positive direct antiglobulin tests for IgG and complement component 3; warm autoantibodies were identified in all these patients. No alternative explanation for clinical hemolysis was found. WAHA required immunosuppressive treatment in 4 of the 6 patients. Conclusions We documented post-babesiosis WAHA in patients who did not have a history of autoimmunity; asplenic patients appeared to be particularly at risk.

  12. Nouns, Verbs and NP Complements.

    ERIC Educational Resources Information Center

    Platt, J. T.

    This paper investigates restrictions on three types of noun-phrase complements (gerundive, infinitive, clause) in English and seeks to point out some parallels between the occurrence of these three types in object positions. The author first presents a list of verbs which may be followed by noun-phrase complements; he then considers the occurrence…

  13. THE ETIOLOGY OF BARTONELLA MURIS ANEMIA OF THE ALBINO RAT

    PubMed Central

    Marmorston-Gottesman, J.; Perla, David

    1932-01-01

    1. Bartonella muris has been isolated in pure culture on Noguchi's leptospira medium from the blood of the splenectomized adult rat suffering with Bartonella muris anemia. 2. Bartonella muris is a small, actively motile, Gram-negative bacillus. It grows best on media containing blood and on Noguchi's leptospira medium. The optimal temperature for growth is 20–25°C. It produces neither gas nor acid on media containing sugars. It does not hemolyze blood in artificial media. Viability of the cultures in leptospira media was maintained for 36 days. 3. With this culture a severe anemia was produced in rats weighing 30 gm., with the occasional appearance of Bartonella muris bodies on the red cells. The anemia occurred within 24 hours, and lasted for 3 to 5 days with recovery of the rat. Bartonella muris was recovered in pure culture from the blood of these animals. The blood of these rats was infectious for other 30 gm. rats. 4. 3 week old rabbits were infected with cultures of Bartonella muris, a severe anemia resulting after an incubation period of 48 hours. The organism was recovered from the blood on the 5th day after injection. Bartonella muris is non-pathogenic for adult rabbits. 5. A severe anemia was produced in young guinea pigs with cultures of Bartonella muris within 48 hours. The organism was recovered on the 2nd and 5th days after injection. Postmortem examination revealed changes in the organs similar to those found in splenectomized rats suffering with spontaneous Bartonella muris anemia. 6. The infection was reproduced in white mice. In one instance a severe anemia developed on the 5th and 6th days. The organism was recovered on the 6th day. 7. The anemia was produced in splenectomized adult rats of non-carrier stock. The organism was recovered from the blood stream of these rats. A marked leukocytosis was noted (65,000) at the peak of the anemia as is found in the spontaneous disease in infected splenectomized adult rats. 8. Serological tests have

  14. Activation of complement during apheresis.

    PubMed Central

    Hetland, G; Mollnes, T E; Garred, P

    1991-01-01

    C3 activation products and the terminal complement complex (TCC) were examined in plasma during plasmapheresis of patients with Guillain-Barré Syndrome (GBS) (n = 4), Waldenström's syndrome (n = 4), and hypercholesterolaemia (n = 1), or during cytapheresis of platelet (n = 10) and granulocyte (n = 2) donors. Blood specimens were taken before, during and after the procedures. There was a significant activation of complement after apheresis in the GBS patients and one of the patients with Waldenström's syndrome, but not in the other patients. There were no significant differences in complement activation products before compared with after cytapheresis in the healthy donors. This demonstrates the biocompatibility with respect to complement activation of the materials used. The observed complement activation in some of the patients during plasma exchange is probably caused by activation products in the replacement plasma. PMID:1904328

  15. Disseminated intravascular coagulation due to IgM-mediated autoimmune hemolytic anemia.

    PubMed

    Bleakly, N Teresa; Fontaine, Magali J; Pate, Lisa L; Sutherland, Scott M; Jeng, Michael

    2011-08-01

    Disseminated intravascular coagulation (DIC) due to red cell hemolysis has been previously attributed to transfusion-related hemolytic reactions, but not to autoimmune hemolytic anemia. We report a case of DIC in a child with complement-fixing IgM-mediated cold-agglutinin autoimmune hemolysis, which resulted in arterial thrombosis and gangrene of the upper and lower extremities.

  16. Complement in health and disease.

    PubMed

    Carroll, Maria V; Sim, Robert B

    2011-09-16

    The complement system consists of about 35-40 proteins and glycoproteins present in blood plasma or on cell surfaces. Its main biological function is to recognise "foreign" particles and macromolecules, and to promote their elimination either by opsonisation or lysis. Although historically complement has been studied as a system for immune defence against bacteria, it has an important homeostatic role in which it recognises damaged or altered "self" components. Thus complement has major roles in both immune defence against microorganisms, and in clearance of damaged or "used" host components. Since complement proteins opsonise or lyse cells, complement can damage healthy host cells and tissues. The system is regulated by many endogenous regulatory proteins. Regulation is sometimes imperfect and both too much and too little complement activation is associated with many diseases. Excessive or inappropriate activation can cause tissue damage in diseases such as rheumatoid arthritis, age-related macular degeneration (AMD), multiple sclerosis, ischemia-reperfusion injury (e.g. ischemic stroke). Insufficient complement activity is associated with susceptibility to infection (mainly bacterial) and development of autoimmune disease, like SLE (systemic lupus erythematosus).

  17. Complement Evasion by Pathogenic Leptospira

    PubMed Central

    Fraga, Tatiana Rodrigues; Isaac, Lourdes; Barbosa, Angela Silva

    2016-01-01

    Leptospirosis is a neglected infectious disease caused by spirochetes from the genus Leptospira. Pathogenic microorganisms, notably those which reach the blood circulation such as Leptospira, have evolved multiple strategies to escape the host complement system, which is important for innate and acquired immunity. Leptospira avoid complement-mediated killing through: (i) recruitment of host complement regulators; (ii) acquisition of host proteases that cleave complement proteins on the bacterial surface; and, (iii) secretion of proteases that inactivate complement proteins in the Leptospira surroundings. The recruitment of host soluble complement regulatory proteins includes the acquisition of Factor H (FH) and FH-like-1 (alternative pathway), C4b-binding protein (C4BP) (classical and lectin pathways), and vitronectin (Vn) (terminal pathway). Once bound to the leptospiral surface, FH and C4BP retain cofactor activity of Factor I in the cleavage of C3b and C4b, respectively. Vn acquisition by leptospires may result in terminal pathway inhibition by blocking C9 polymerization. The second evasion mechanism lies in plasminogen (PLG) binding to the leptospiral surface. In the presence of host activators, PLG is converted to enzymatically active plasmin, which is able to degrade C3b, C4b, and C5 at the surface of the pathogen. A third strategy used by leptospires to escape from complement system is the active secretion of proteases. Pathogenic, but not saprophytic leptospires, are able to secrete metalloproteases that cleave C3 (central complement molecule), Factor B (alternative pathway), and C4 and C2 (classical and lectin pathways). The purpose of this review is to fully explore these complement evasion mechanisms, which act together to favor Leptospira survival and multiplication in the host. PMID:28066433

  18. Complement Evasion by Pathogenic Leptospira.

    PubMed

    Fraga, Tatiana Rodrigues; Isaac, Lourdes; Barbosa, Angela Silva

    2016-01-01

    Leptospirosis is a neglected infectious disease caused by spirochetes from the genus Leptospira. Pathogenic microorganisms, notably those which reach the blood circulation such as Leptospira, have evolved multiple strategies to escape the host complement system, which is important for innate and acquired immunity. Leptospira avoid complement-mediated killing through: (i) recruitment of host complement regulators; (ii) acquisition of host proteases that cleave complement proteins on the bacterial surface; and, (iii) secretion of proteases that inactivate complement proteins in the Leptospira surroundings. The recruitment of host soluble complement regulatory proteins includes the acquisition of Factor H (FH) and FH-like-1 (alternative pathway), C4b-binding protein (C4BP) (classical and lectin pathways), and vitronectin (Vn) (terminal pathway). Once bound to the leptospiral surface, FH and C4BP retain cofactor activity of Factor I in the cleavage of C3b and C4b, respectively. Vn acquisition by leptospires may result in terminal pathway inhibition by blocking C9 polymerization. The second evasion mechanism lies in plasminogen (PLG) binding to the leptospiral surface. In the presence of host activators, PLG is converted to enzymatically active plasmin, which is able to degrade C3b, C4b, and C5 at the surface of the pathogen. A third strategy used by leptospires to escape from complement system is the active secretion of proteases. Pathogenic, but not saprophytic leptospires, are able to secrete metalloproteases that cleave C3 (central complement molecule), Factor B (alternative pathway), and C4 and C2 (classical and lectin pathways). The purpose of this review is to fully explore these complement evasion mechanisms, which act together to favor Leptospira survival and multiplication in the host.

  19. Genetics of the complement system.

    PubMed Central

    Lachmann, P

    1975-01-01

    The complement system, unlike the coagulation system, was largely characterized by in-vitro techniques which did not make use of genetically deficient plasmas. The existence of the genetically deficient plasmas. The existence of the genetically deficient subjects therefore has served largely to increase our knowledge of the in-vivo role of complement. At the present time its clearest role is in the resistance to infection; obviously in the case of C3 deficiency and bacterial infection and possibly more subtly in the case of deficiency of the early active complement components and low virulence organisms. There is so far no evidence that genetic complement deficiency interferes with antibody formation or with the generation of tolerance as has been suggested in the pas (Azar et al, 1968; Dukor and Hartmann, 1973). PMID:768477

  20. Adefovir dipivoxil-induced Fanconi syndrome and its predictive factors: A study of 28 cases.

    PubMed

    Lin, Yong; Pan, Fan; Wang, Yingchao; Chen, Ziqian; Lin, Chun; Yao, Lvfeng; Zhang, Xin; Zhou, Rui; Pan, Chen

    2017-01-01

    The aim of the present study was to identify monitoring and prevention measures as well as predictive factors for early detection of renal toxicity associated with long-term administration of adefovir dipivoxil in order to avoid progression to Fanconi syndrome. Clinical data of 28 patients with Fanconi syndrome caused by long-term administration of adefovir dipivoxil for the treatment of chronic hepatitis B virus (HBV) infection were collected pre-and post-administration for analysis. Patients presented with fatigue, progressive systemic pain in multiple bones and joints, as well as difficulty in walking and pathological fractures in a number of severe cases. Laboratory examinations revealed hypophosphatemia, elevated serum cystatin C (Cys-C), elevated serum creatinine (SCr), reduced glomerular filtration rate (GFR), positive urinary protein, erythrocytes and glucose, as well as osteoporosis. In consequence, adefovir dipivoxil administration was stopped, and patients received concentrated divitamins, sodium phosphate syrup and calcitriol. Symptoms and abnormalities in laboratory examinations were significantly improved in all patients after 2-6 months. Therefore, serum phosphate, SCr, routine urine parameters, Cys-C and GFR should be monitored regularly in chronic HBV patients treated with adefovir dipivoxil. The following factors were identified as predictive of kidney damage and Fanconi syndrome: Age ≥40 years, living in rural areas, previous renal toxicity, estimated GFR (eGFR) <90 ml/min/1.73 m(2), hypertension, diabetes, cirrhosis and duration of adefovir dipivoxil treatment exceeding 24 months. The present results indicate that timely termination of adefovir dipivoxil treatment and replacement with other antiviral agents is critical once renal impairment appears, and that it is necessary to change to other antiviral agents and prolong the interval of administration according to the eGFR level.