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Sample records for brca2 mediate structural

  1. A human BRCA2 complex containing a structural DNA binding component influences cell cycle progression.

    Science.gov (United States)

    Marmorstein, L Y; Kinev, A V; Chan, G K; Bochar, D A; Beniya, H; Epstein, J A; Yen, T J; Shiekhattar, R

    2001-01-26

    Germline mutations of the human BRCA2 gene confer susceptibility to breast cancer. Although the function of the BRCA2 protein remains to be determined, murine cells homozygous for BRCA2 inactivation display chromosomal aberrations. We have isolated a 2 MDa BRCA2-containing complex and identified a structural DNA binding component, designated as BRCA2-Associated Factor 35 (BRAF35). BRAF35 contains a nonspecific DNA binding HMG domain and a kinesin-like coiled coil domain. Similar to BRCA2, BRAF35 mRNA expression levels in mouse embryos are highest in proliferating tissues with high mitotic index. Strikingly, nuclear staining revealed a close association of BRAF35/BRCA2 complex with condensed chromatin coincident with histone H3 phosphorylation. Importantly, antibody microinjection experiments suggest a role for BRCA2/BRAF35 complex in modulation of cell cycle progression. PMID:11207365

  2. The epistatic relationship between BRCA2 and the other RAD51 mediators in homologous recombination.

    Directory of Open Access Journals (Sweden)

    Yong Qing

    2011-07-01

    Full Text Available RAD51 recombinase polymerizes at the site of double-strand breaks (DSBs where it performs DSB repair. The loss of RAD51 causes extensive chromosomal breaks, leading to apoptosis. The polymerization of RAD51 is regulated by a number of RAD51 mediators, such as BRCA1, BRCA2, RAD52, SFR1, SWS1, and the five RAD51 paralogs, including XRCC3. We here show that brca2-null mutant cells were able to proliferate, indicating that RAD51 can perform DSB repair in the absence of BRCA2. We disrupted the BRCA1, RAD52, SFR1, SWS1, and XRCC3 genes in the brca2-null cells. All the resulting double-mutant cells displayed a phenotype that was very similar to that of the brca2-null cells. We suggest that BRCA2 might thus serve as a platform to recruit various RAD51 mediators at the appropriate position at the DNA-damage site.

  3. Haplotype structure in Ashkenazi Jewish BRCA1 and BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Im, Kate M; Kirchhoff, Tomas; Wang, Xianshu;

    2011-01-01

    Three founder mutations in BRCA1 and BRCA2 contribute to the risk of hereditary breast and ovarian cancer in Ashkenazi Jews (AJ). They are observed at increased frequency in the AJ compared to other BRCA mutations in Caucasian non-Jews (CNJ). Several authors have proposed that elevated allele fre...

  4. Haplotype structure in Ashkenazi Jewish BRCA1 and BRCA2 mutation carriers

    NARCIS (Netherlands)

    Im, Kate M.; Kirchhoff, Tomas; Wang, Xianshu; Green, Todd; Chow, Clement Y.; Vijai, Joseph; Korn, Joshua; Gaudet, Mia M.; Fredericksen, Zachary; Pankratz, V. Shane; Guiducci, Candace; Crenshaw, Andrew; McGuffog, Lesley; Kartsonaki, Christiana; Morrison, Jonathan; Healey, Sue; Sinilnikova, Olga M.; Mai, Phuong L.; Greene, Mark H.; Piedmonte, Marion; Rubinstein, Wendy S.; Hogervorst, Frans B.; Rookus, Matti A.; Collee, J. Margriet; Hoogerbrugge, Nicoline; van Asperen, Christi J.; Meijers-Heijboer, Hanne E. J.; van Roozendaal, Cees E.; Caldes, Trinidad; Perez-Segura, Pedro; Jakubowska, Anna; Lubinski, Jan; Huzarski, Tomasz; Blecharz, Pawel; Nevanlinna, Heli; Aittomaki, Kristiina; Lazaro, Conxi; Blanco, Ignacio; Barkardottir, Rosa B.; Montagna, Marco; D'Andrea, Emma; Devilee, Peter; Olopade, Olufunmilayo I.; Neuhausen, Susan L.; Peissel, Bernard; Bonanni, Bernardo; Peterlongo, Paolo; Singer, Christian F.; Rennert, Gad; Lejbkowicz, Flavio; Andrulis, Irene L.; Glendon, Gord; Ozcelik, Hilmi; Toland, Amanda Ewart; Caligo, Maria Adelaide; Beattie, Mary S.; Chan, Salina; Domchek, Susan M.; Nathanson, Katherine L.; Rebbeck, Timothy R.; Phelan, Catherine; Narod, Steven; John, Esther M.; Hopper, John L.; Buys, Saundra S.; Daly, Mary B.; Southey, Melissa C.; Terry, Mary-Beth; Tung, Nadine; Hansen, Thomas V. O.; Osorio, Ana; Benitez, Javier; Duran, Mercedes; Weitzel, Jeffrey N.; Garber, Judy; Hamann, Ute; Peock, Susan; Cook, Margaret; Oliver, Clare T.; Frost, Debra; Platte, Radka; Evans, D. Gareth; Eeles, Ros; Izatt, Louise; Paterson, Joan; Brewer, Carole; Hodgson, Shirley; Morrison, Patrick J.; Porteous, Mary; Walker, Lisa; Rogers, Mark T.; Side, Lucy E.; Godwin, Andrew K.; Schmutzler, Rita K.; Wappenschmidt, Barbara; Laitman, Yael; Meindl, Alfons; Deissler, Helmut; Varon-Mateeva, Raymonda; Preisler-Adams, Sabine; Kast, Karin; Venat-Bouvet, Laurence; Stoppa-Lyonnet, Dominique; Chenevix-Trench, Georgia; Easton, Douglas F.; Klein, Robert J.; Daly, Mark J.; Friedman, Eitan; Dean, Michael; Clark, Andrew G.; Altshuler, David M.; Antoniou, Antonis C.; Couch, Fergus J.; Offit, Kenneth; Gold, Bert

    2011-01-01

    Three founder mutations in BRCA1 and BRCA2 contribute to the risk of hereditary breast and ovarian cancer in Ashkenazi Jews (AJ). They are observed at increased frequency in the AJ compared to other BRCA mutations in Caucasian non-Jews (CNJ). Several authors have proposed that elevated allele freque

  5. BRCA1 and BRCA2 gene testing

    Science.gov (United States)

    The BRCA1 and BRCA2 gene test is a blood test that can tell you if you have a higher ... BRCA1 and BRCA2 are genes that suppress malignant tumors (cancer) in humans. When these genes change (become ...

  6. Deficiency of human BRCA2 leads to impaired homologous recombination but maintains normal nonhomologous end joining.

    Science.gov (United States)

    Xia, F; Taghian, D G; DeFrank, J S; Zeng, Z C; Willers, H; Iliakis, G; Powell, S N

    2001-07-17

    Carriers of BRCA2 germline mutations are at high risk to develop early-onset breast cancer. The underlying mechanisms of how BRCA2 inactivation predisposes to malignant transformation have not been established. Here, we provide direct functional evidence that human BRCA2 promotes homologous recombination (HR), which comprises one major pathway of DNA double-strand break repair. We found that up-regulated HR after transfection of wild-type (wt) BRCA2 into a human tumor line with mutant BRCA2 was linked to increased radioresistance. In addition, BRCA2-mediated enhancement of HR depended on the interaction with Rad51. In contrast to the tumor suppressor BRCA1, which is involved in multiple DNA repair pathways, BRCA2 status had no impact on the other principal double-strand break repair pathway, nonhomologous end joining. Thus, there exists a specific regulation of HR by BRCA2, which may function to maintain genomic integrity and suppress tumor development in proliferating cells. PMID:11447276

  7. Interrogation of the protein-protein interactions between human BRCA2 BRC repeats and RAD51 reveals atomistic determinants of affinity

    OpenAIRE

    Cole, Daniel J.; Eeson Rajendra; Meredith Roberts-Thomson; Bryn Hardwick; Grahame J. McKenzie; Payne, Mike C.; Ashok R Venkitaraman; Chris-Kriton Skylaris

    2011-01-01

    The breast cancer suppressor BRCA2 controls the recombinase RAD51 in the reactions that mediate homologous DNA recombination, an essential cellular process required for the error-free repair of DNA double-stranded breaks. The primary mode of interaction between BRCA2 and RAD51 is through the BRC repeats, which are ~35 residue peptide motifs that interact directly with RAD51 in vitro. Human BRCA2, like its mammalian orthologues, contains 8 BRC repeats whose sequence and spacing are evolutionar...

  8. Effect of BRCA2 sequence variants predicted to disrupt exonic splice enhancers on BRCA2 transcripts

    Directory of Open Access Journals (Sweden)

    Brewster Brooke L

    2010-05-01

    Full Text Available Abstract Background Genetic screening of breast cancer patients and their families have identified a number of variants of unknown clinical significance in the breast cancer susceptibility genes, BRCA1 and BRCA2. Evaluation of such unclassified variants may be assisted by web-based bioinformatic prediction tools, although accurate prediction of aberrant splicing by unclassified variants affecting exonic splice enhancers (ESEs remains a challenge. Methods This study used a combination of RT-PCR analysis and splicing reporter minigene assays to assess five unclassified variants in the BRCA2 gene that we had previously predicted to disrupt an ESE using bioinformatic approaches. Results Analysis of BRCA2 c.8308 G > A (p.Ala2770Thr by mRNA analysis, and BRCA2 c.8962A > G (p.Ser2988Gly, BRCA2 c.8972G > A (p.Arg2991His, BRCA2 c.9172A > G (p.Ser3058Gly, and BRCA2 c.9213G > T (p.Glu3071Asp by a minigene assay, revealed no evidence for aberrant splicing. Conclusions These results illustrate the need for improved methods for predicting functional ESEs and the potential consequences of sequence variants contained therein.

  9. Cycling with BRCA2 from DNA repair to mitosis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyunsook, E-mail: HL212@snu.ac.kr

    2014-11-15

    Genetic integrity in proliferating cells is guaranteed by the harmony of DNA replication, appropriate DNA repair, and segregation of the duplicated genome. Breast cancer susceptibility gene BRCA2 is a unique tumor suppressor that is involved in all three processes. Hence, it is critical in genome maintenance. The functions of BRCA2 in DNA repair and homology-directed recombination (HDR) have been reviewed numerous times. Here, I will briefly go through the functions of BRCA2 in HDR and focus on the emerging roles of BRCA2 in telomere homeostasis and mitosis, then discuss how BRCA2 exerts distinct functions in a cell-cycle specific manner in the maintenance of genomic integrity. - Highlights: • BRCA2 is a multifaceted tumor suppressor and is crucial in genetic integrity. • BRCA2 exerts distinct functions in cell cycle-specific manner. • Mitotic kinases regulate diverse functions of BRCA2 in mitosis and cytokinesis.

  10. Cycling with BRCA2 from DNA repair to mitosis

    International Nuclear Information System (INIS)

    Genetic integrity in proliferating cells is guaranteed by the harmony of DNA replication, appropriate DNA repair, and segregation of the duplicated genome. Breast cancer susceptibility gene BRCA2 is a unique tumor suppressor that is involved in all three processes. Hence, it is critical in genome maintenance. The functions of BRCA2 in DNA repair and homology-directed recombination (HDR) have been reviewed numerous times. Here, I will briefly go through the functions of BRCA2 in HDR and focus on the emerging roles of BRCA2 in telomere homeostasis and mitosis, then discuss how BRCA2 exerts distinct functions in a cell-cycle specific manner in the maintenance of genomic integrity. - Highlights: • BRCA2 is a multifaceted tumor suppressor and is crucial in genetic integrity. • BRCA2 exerts distinct functions in cell cycle-specific manner. • Mitotic kinases regulate diverse functions of BRCA2 in mitosis and cytokinesis

  11. Interrogation of the protein-protein interactions between human BRCA2 BRC repeats and RAD51 reveals atomistic determinants of affinity.

    Science.gov (United States)

    Cole, Daniel J; Rajendra, Eeson; Roberts-Thomson, Meredith; Hardwick, Bryn; McKenzie, Grahame J; Payne, Mike C; Venkitaraman, Ashok R; Skylaris, Chris-Kriton

    2011-07-01

    The breast cancer suppressor BRCA2 controls the recombinase RAD51 in the reactions that mediate homologous DNA recombination, an essential cellular process required for the error-free repair of DNA double-stranded breaks. The primary mode of interaction between BRCA2 and RAD51 is through the BRC repeats, which are ∼35 residue peptide motifs that interact directly with RAD51 in vitro. Human BRCA2, like its mammalian orthologues, contains 8 BRC repeats whose sequence and spacing are evolutionarily conserved. Despite their sequence conservation, there is evidence that the different human BRC repeats have distinct capacities to bind RAD51. A previously published crystal structure reports the structural basis of the interaction between human BRC4 and the catalytic core domain of RAD51. However, no structural information is available regarding the binding of the remaining seven BRC repeats to RAD51, nor is it known why the BRC repeats show marked variation in binding affinity to RAD51 despite only subtle sequence variation. To address these issues, we have performed fluorescence polarisation assays to indirectly measure relative binding affinity, and applied computational simulations to interrogate the behaviour of the eight human BRC-RAD51 complexes, as well as a suite of BRC cancer-associated mutations. Our computational approaches encompass a range of techniques designed to link sequence variation with binding free energy. They include MM-PBSA and thermodynamic integration, which are based on classical force fields, and a recently developed approach to computing binding free energies from large-scale quantum mechanical first principles calculations with the linear-scaling density functional code onetep. Our findings not only reveal how sequence variation in the BRC repeats directly affects affinity with RAD51 and provide significant new insights into the control of RAD51 by human BRCA2, but also exemplify a palette of computational and experimental tools for the

  12. Interrogation of the protein-protein interactions between human BRCA2 BRC repeats and RAD51 reveals atomistic determinants of affinity.

    Directory of Open Access Journals (Sweden)

    Daniel J Cole

    2011-07-01

    Full Text Available The breast cancer suppressor BRCA2 controls the recombinase RAD51 in the reactions that mediate homologous DNA recombination, an essential cellular process required for the error-free repair of DNA double-stranded breaks. The primary mode of interaction between BRCA2 and RAD51 is through the BRC repeats, which are ∼35 residue peptide motifs that interact directly with RAD51 in vitro. Human BRCA2, like its mammalian orthologues, contains 8 BRC repeats whose sequence and spacing are evolutionarily conserved. Despite their sequence conservation, there is evidence that the different human BRC repeats have distinct capacities to bind RAD51. A previously published crystal structure reports the structural basis of the interaction between human BRC4 and the catalytic core domain of RAD51. However, no structural information is available regarding the binding of the remaining seven BRC repeats to RAD51, nor is it known why the BRC repeats show marked variation in binding affinity to RAD51 despite only subtle sequence variation. To address these issues, we have performed fluorescence polarisation assays to indirectly measure relative binding affinity, and applied computational simulations to interrogate the behaviour of the eight human BRC-RAD51 complexes, as well as a suite of BRC cancer-associated mutations. Our computational approaches encompass a range of techniques designed to link sequence variation with binding free energy. They include MM-PBSA and thermodynamic integration, which are based on classical force fields, and a recently developed approach to computing binding free energies from large-scale quantum mechanical first principles calculations with the linear-scaling density functional code onetep. Our findings not only reveal how sequence variation in the BRC repeats directly affects affinity with RAD51 and provide significant new insights into the control of RAD51 by human BRCA2, but also exemplify a palette of computational and

  13. Contributions of the RAD51 N-terminal domain to BRCA2-RAD51 interaction.

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    Subramanyam, Shyamal; Jones, William T; Spies, Maria; Spies, M Ashley

    2013-10-01

    RAD51 DNA strand exchange protein catalyzes the central step in homologous recombination, a cellular process fundamentally important for accurate repair of damaged chromosomes, preservation of the genetic integrity, restart of collapsed replication forks and telomere maintenance. BRCA2 protein, a product of the breast cancer susceptibility gene, is a key recombination mediator that interacts with RAD51 and facilitates RAD51 nucleoprotein filament formation on single-stranded DNA generated at the sites of DNA damage. An accurate atomistic level description of this interaction, however, is limited to a partial crystal structure of the RAD51 core fused to BRC4 peptide. Here, by integrating homology modeling and molecular dynamics, we generated a structure of the full-length RAD51 in complex with BRC4 peptide. Our model predicted previously unknown hydrogen bonding patterns involving the N-terminal domain (NTD) of RAD51. These interactions guide positioning of the BRC4 peptide within a cavity between the core and the NTDs; the peptide binding separates the two domains and restricts internal dynamics of RAD51 protomers. The model's depiction of the RAD51-BRC4 complex was validated by free energy calculations and in vitro functional analysis of rationally designed mutants. All generated mutants, RAD51(E42A), RAD51(E59A), RAD51(E237A), RAD51(E59A/E237A) and RAD51(E42A/E59A/E237A) maintained basic biochemical activities of the wild-type RAD51, but displayed reduced affinities for the BRC4 peptide. Strong correlation between the calculated and experimental binding energies confirmed the predicted structure of the RAD51-BRC4 complex and highlighted the importance of RAD51 NTD in RAD51-BRCA2 interaction. PMID:23935068

  14. Interrogation of the Protein-Protein Interactions between Human BRCA2 BRC Repeats and RAD51 Reveals Atomistic Determinants of Affinity

    OpenAIRE

    Cole, Daniel J.; Rajendra, Eeson; Roberts-Thomson, Meredith; Hardwick, Bryn; Grahame J. McKenzie; Payne, Mike C.; Ashok R Venkitaraman; Skylaris, Chris-Kriton

    2011-01-01

    The breast cancer suppressor BRCA2 controls the recombinase RAD51 in the reactions that mediate homologous DNA recombination, an essential cellular process required for the error-free repair of DNA double-stranded breaks. The primary mode of interaction between BRCA2 and RAD51 is through the BRC repeats, which are ∼35 residue peptide motifs that interact directly with RAD51 in vitro. Human BRCA2, like its mammalian orthologues, contains 8 BRC repeats whose sequence and spacing are evolutionar...

  15. Cloning a cDNA encoding an alternatively spliced protein of BRCA2-associated factor 35.

    Science.gov (United States)

    Wang, Chiang; McCarty, Ida M; Balazs, Louisa; Li, Yi; Steiner, Mitchell S

    2002-07-01

    Inheritance of mutations in the breast cancer susceptibility gene, BRCA2, predisposes humans to breast and ovarian cancers. Inherited mutations in the BRCA2 gene are also known to cause susceptibility to prostate cancer. BRCA2 protein exists in a large multi-protein complex from which a novel structural DNA binding protein BRCA2-associated factor 35 (BRAF35) has been isolated. We have cloned a novel cDNA encoding an alternatively spliced protein of BRAF35, designated as BRAF25. BRAF25 transcript is present in various human cells. We have precisely mapped the BRAF25 cDNA sequence to the genomic chromosome 19 sequence. Analysis of the predicted sequence of BRAF25 identified a protein of 215 amino acids. BRAF25 contains a truncated high mobility group domain, a kinesin-like coiled-coil domain and multiple Src homology 2 (SH2) motifs. Western blot analysis using antibodies specific for BRAF25 revealed the presence of BRAF25 in human prostate cancer cells. PMID:12083779

  16. A mitotic function for the high-mobility group protein HMG20b regulated by its interaction with the BRC repeats of the BRCA2 tumor suppressor.

    Science.gov (United States)

    Lee, M; Daniels, M J; Garnett, M J; Venkitaraman, A R

    2011-07-28

    The inactivation of BRCA2, a suppressor of breast, ovarian and other epithelial cancers, triggers instability in chromosome structure and number, which are thought to arise from defects in DNA recombination and mitotic cell division, respectively. Human BRCA2 controls DNA recombination via eight BRC repeats, evolutionarily conserved motifs of ∼35 residues, that interact directly with the recombinase RAD51. How BRCA2 controls mitotic cell division is debated. Several studies by different groups report that BRCA2 deficiency affects cytokinesis. Moreover, its interaction with HMG20b, a protein of uncertain function containing a promiscuous DNA-binding domain and kinesin-like coiled coils, has been implicated in the G2-M transition. We show here that HMG20b depletion by RNA interference disturbs the completion of cell division, suggesting a novel function for HMG20b. In vitro, HMG20b binds directly to the BRC repeats of BRCA2, and exhibits the highest affinity for BRC5, a motif that binds poorly to RAD51. Conversely, the BRC4 repeat binds strongly to RAD51, but not to HMG20b. In vivo, BRC5 overexpression inhibits the BRCA2-HMG20b interaction, recapitulating defects in the completion of cell division provoked by HMG20b depletion. In contrast, BRC4 inhibits the BRCA2-RAD51 interaction and the assembly of RAD51 at sites of DNA damage, but not the completion of cell division. Our findings suggest that a novel function for HMG20b in cytokinesis is regulated by its interaction with the BRC repeats of BRCA2, and separate this unexpected function for the BRC repeats from their known activity in DNA recombination. We propose that divergent tumor-suppressive pathways regulating chromosome segregation as well as chromosome structure may be governed by the conserved BRC motifs in BRCA2. PMID:21399666

  17. Tumor Mutation Burden Forecasts Outcome in Ovarian Cancer with BRCA1 or BRCA2 Mutations

    DEFF Research Database (Denmark)

    Birkbak, Nicolai Juul; Kochupurakkal, Bose; Gonzalez-Izarzugaza, Jose Maria;

    2013-01-01

    Background: Increased number of single nucleotide substitutions is seen in breast and ovarian cancer genomes carrying disease-associated mutations in BRCA1 or BRCA2. The significance of these genome-wide mutations is unknown. We hypothesize genome-wide mutation burden mirrors deficiencies in DNA ...... cancer is a genomic marker of prognosis and predictor of treatment response. This marker may reflect the degree of deficiency in BRCA-mediated pathways, or the extent of compensation for the deficiency by alternative echanisms....... repair and is associated with treatment outcome in ovarian cancer. Methods and Results: The total number of synonymous and non-synonymous exome mutations (Nmut), and the presence of germline or somatic mutation in BRCA1 or BRCA2 (mBRCA) were extracted from whole-exome sequences of high-grade serous...... mutations. In cancers with wild-type BRCA, tumor Nmut was associated with treatment response in patients with no residual disease after surgery. Conclusions: Tumor Nmut was associated with treatment response and with both PFS and OS in patients with highgrade serous ovarian cancer carrying BRCA1 or BRCA2...

  18. BRCA2 Mutations in 154 Finnish Male Breast Cancer Patients

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    Kirsi Syrjäkoski

    2004-09-01

    Full Text Available The etiology and pathogenesis of male breast cancer (MBC are poorly known. This is due to the fact that the disease is rare, and large-scale genetic epidemiologic studies have been difficult to carry out. Here, we studied the frequency of eight recurrent Finnish BRCA2 founder mutations in a large cohort of 154 MBC patients (65% diagnosed in Finland from 1967 to 1996. Founder mutations were detected in 10 patients (6.5%, eight of whom carried the 9346(-2 A>G mutation. Two novel mutations (4075 delGT and 5808 del5 were discovered in a screening of the entire BRCA2 coding region in 34 samples. However, these mutations were not found in the rest of the 120 patients studied. Patients with positive family history of breast and/or ovarian cancer were often BRCA2 mutation carriers (44%, whereas those with no family history showed a low frequency of involvement (3.6%; P < .0001. Finally, we found only one Finnish MBC patient with 999 dell, the most common founder mutation in Finnish female breast cancer (FBC patients, and one that explains most of the hereditary FBC and MBC cases in Iceland. The variation in BRCA2 mutation spectrum between Finnish MBC patients and FBC patients in Finland and breast cancer patients in Iceland suggests that modifying genetic and environmental factors may significantly influence the penetrance of MBC and FBC in individuals carrying germline BRCA2 mutations in some populations.

  19. Comprehensive genomic analysis of a BRCA2 deficient human pancreatic cancer.

    Directory of Open Access Journals (Sweden)

    Louise J Barber

    Full Text Available Capan-1 is a well-characterised BRCA2-deficient human cell line isolated from a liver metastasis of a pancreatic adenocarcinoma. Here we report a genome-wide assessment of structural variations and high-depth exome characterization of single nucleotide variants and small insertion/deletions in Capan-1. To identify potential somatic and tumour-associated variations in the absence of a matched-normal cell line, we devised a novel method based on the analysis of HapMap samples. We demonstrate that Capan-1 has one of the most rearranged genomes sequenced to date. Furthermore, small insertions and deletions are detected more frequently in the context of short sequence repeats than in other genomes. We also identify a number of novel mutations that may represent genetic changes that have contributed to tumour progression. These data provide insight into the genomic effects of loss of BRCA2 function.

  20. Comprehensive Genomic Analysis of a BRCA2 Deficient Human Pancreatic Cancer

    Science.gov (United States)

    Kozarewa, Iwanka; Fenwick, Kerry; Assiotis, Ioannis; Mitsopoulos, Costas; Sims, David; Hakas, Jarle; Zvelebil, Marketa; Lord, Christopher J.; Ashworth, Alan

    2011-01-01

    Capan-1 is a well-characterised BRCA2-deficient human cell line isolated from a liver metastasis of a pancreatic adenocarcinoma. Here we report a genome-wide assessment of structural variations and high-depth exome characterization of single nucleotide variants and small insertion/deletions in Capan-1. To identify potential somatic and tumour-associated variations in the absence of a matched-normal cell line, we devised a novel method based on the analysis of HapMap samples. We demonstrate that Capan-1 has one of the most rearranged genomes sequenced to date. Furthermore, small insertions and deletions are detected more frequently in the context of short sequence repeats than in other genomes. We also identify a number of novel mutations that may represent genetic changes that have contributed to tumour progression. These data provide insight into the genomic effects of loss of BRCA2 function. PMID:21750719

  1. BRCA1/BRCA2 founder mutations and cancer risks

    DEFF Research Database (Denmark)

    Nielsen, Henriette Roed; Nilbert, Mef; Petersen, Janne; Ladelund, Steen; Thomassen, Mads; Pedersen, Inge Søkilde; Hansen, Thomas V O; Skytte, Anne-Bine; Borg, Åke; Therkildsen, Christina

    2016-01-01

    Mutations in the BRCA1 and BRCA2 genes significantly contribute to hereditary breast cancer and ovarian cancer, but the phenotypic effect from different mutations is insufficiently recognized. We used a western Danish clinic-based cohort of 299 BRCA families to study the female cancer risk in...... mutation carriers and their untested first-degree relatives. Founder mutations were characterized and the risk of cancer was assessed in relation to the specific mutations. In BRCA1, the cumulative cancer risk at age 70 was 35 % for breast cancer and 29 % for ovarian cancer. In BRCA2, the cumulative risk...... was 44 % for breast cancer and 15 % for ovarian cancer. We identified 47 distinct BRCA1 mutations and 48 distinct mutations in BRCA2. Among these, 8 founder mutations [BRCA1 c.81-?_4986+?del, c.3319G>T (p.Glu1107*), c.3874delT and c.5213G>A (p.Gly1738Glu) and BRCA2 c.6373delA, c.7008-1G>A, c.7617+1G...

  2. Comprehensive BRCA1 and BRCA2 mutational profile in Lithuania.

    Science.gov (United States)

    Janavičius, Ramūnas; Rudaitis, Vilius; Mickys, Ugnius; Elsakov, Pavel; Griškevičius, Laimonas

    2014-05-01

    There is limited knowledge about the BRCA1/2 mutational profile in Lithuania. We aimed to define the full BRCA1 and BRCA2 mutational spectrum and the clinically relevant prevalence of these gene mutations in Lithuania. A data set of 753 unrelated probands, recruited through a clinical setting, was used and consisted of 380 female breast cancer cases, 213 epithelial ovarian cancer cases, 20 breast and ovarian cancer cases, and 140 probands with positive family history of breast or ovarian cancer. A comprehensive mutation analysis of the BRCA1/2 genes by high resolution melting analysis coupled with Sanger sequencing and multiplex ligation-dependent probe amplification analysis was performed. Genetic analysis revealed 32 different pathogenic germline BRCA1/2 mutations: 20 in the BRCA1 gene and 12 in the BRCA2 gene, including four different large genomic rearrangements in the BRCA1 gene. In all, 10 novel BRCA1/2 mutations were found. Nine different recurrent BRCA1 mutations and two recurrent BRCA2 mutations were identified, which comprised 90.4% of all BRCA1/2 mutations. BRCA1 exon 1-3 deletion and BRCA2 c.658_659del are reported for the first time as recurrent mutations, pointing to a possible Baltic founder effect. Approximately 7% of breast cancer and 22% of ovarian cancer patients without family history and an estimated 0.5-0.6% of all Lithuanian women were found to be carriers of mutations in the BRCA1 or BRCA2 gene. PMID:25066507

  3. Contralateral breast cancer after radiotherapy among BRCA1 and BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Bernstein, Jonine L; Thomas, Duncan C; Shore, Roy E;

    2013-01-01

    Women with germline BRCA1 or BRCA2 (BRCA1/BRCA2) mutations are at very high risk of developing breast cancer, including asynchronous contralateral breast cancer (CBC). BRCA1/BRCA2 genes help maintain genome stability and assist in DNA repair. We examined whether the risk of CBC associated with...

  4. Common genetic variants and modification of penetrance of BRCA2-associated breast cancer

    DEFF Research Database (Denmark)

    Gaudet, Mia M; Kirchhoff, Tomas; Green, Todd;

    2010-01-01

    The considerable uncertainty regarding cancer risks associated with inherited mutations of BRCA2 is due to unknown factors. To investigate whether common genetic variants modify penetrance for BRCA2 mutation carriers, we undertook a two-staged genome-wide association study in BRCA2 mutation carri...

  5. Comprehensive Genomic Analysis of a BRCA2 Deficient Human Pancreatic Cancer

    OpenAIRE

    Barber, Louise J.; Rosa Rosa, Juan M.; Kozarewa, Iwanka; Fenwick, Kerry; Assiotis, Ioannis; Mitsopoulos, Costas; Sims, David; Hakas, Jarle; Zvelebil, Marketa; Lord, Christopher J; Ashworth, Alan

    2011-01-01

    Capan-1 is a well-characterised BRCA2-deficient human cell line isolated from a liver metastasis of a pancreatic adenocarcinoma. Here we report a genome-wide assessment of structural variations and high-depth exome characterization of single nucleotide variants and small insertion/deletions in Capan-1. To identify potential somatic and tumour-associated variations in the absence of a matched-normal cell line, we devised a novel method based on the analysis of HapMap samples. We demonstrate th...

  6. Classifying Variants of Undetermined Significance in BRCA2 with Protein Likelihood Ratios

    Directory of Open Access Journals (Sweden)

    Mary S. Beattie

    2008-01-01

    Full Text Available Background: Missense (amino-acid changing variants found in cancer predisposition genes often create difficulties when clinically interpreting genetic testing results. Although bioinformatics has developed approaches to predicting the impact of these variants, many of these approaches have not been readily applicable in the clinical setting. Bioinformatics approaches for predicting the impact of these variants have not yet found their footing in clinical practice because 1 interpreting the medical relevance of predictive scores is difficult; 2 the relationship between bioinformatics “predictors” (sequence conservation, protein structure and cancer susceptibility is not understood.Methodology/Principal Findings: We present a computational method that produces a probabilistic likelihood ratio predictive of whether a missense variant impairs protein function. We apply the method to a tumor suppressor gene, BRCA2, whose loss of function is important to cancer susceptibility. Protein likelihood ratios are computed for 229 unclassified variants found in individuals from high-risk breast/ovarian cancer families. We map the variants onto a protein structure model, and suggest that a cluster of predicted deleterious variants in the BRCA2 OB1 domain may destabilize BRCA2 and a protein binding partner, the small acidic protein DSS1. We compare our predictions with variant “re-classifications” provided by Myriad Genetics, a biotechnology company that holds the patent on BRCA2 genetic testing in the U.S., and with classifications made by an established medical genetics model [1]. Our approach uses bioinformatics data that is independent of these genetics-based classifications and yet shows significant agreement with them. Preliminary results indicate that our method is less likely to make false positive errors than other bioinformatics methods, which were designed to predict the impact of missense mutations in general

  7. Molecular characterization, homology modeling and docking studies of the R2787H missense variation in BRCA2 gene: Association with breast cancer.

    Science.gov (United States)

    Riahi, Aouatef; Messaoudi, Abdelmonem; Mrad, Ridha; Fourati, Asma; Chabouni-Bouhamed, Habiba; Kharrat, Maher

    2016-08-21

    The significance of many BRCA unclassified variants (UVs) has not been evaluated. Classification of these variations as neutral or pathogenic presents a significant challenge and has important implications for breast and ovarian cancer genetic counseling. Here we report a combined molecular and computational approach to classify BRCA UVs missense variations. By using the LOH (Loss of heterozygosity) analysis at the BRCA1/BRCA2 loci, five bioinformatics approaches namely fathmm, PhD-SNP, SNAP, MutationTaster and Human Splicing Finder and the association with the clinico-pathological characteristics related to BRCA tumors, we were able to classify the R2787H (in BRCA2 gene) variant as pathogenic. Then, to investigate the functional role of the R2787H variation in altering BRCA2 structure, the homology model of this variant was constructed using the Rattus norvegicus BRCA2 (PDB ID: 1IYJ) as a template. The predicted model was then assessed for stereochemical quality and side chain environment. Furthermore, docking and binding free energy simulations were performed to investigate the ssDNA-BRCA2 complex interaction. Binding energy value calculation proves that this substitution affects the complex stability. Moreover, this alteration was not found in one hundred healthy controls. These findings suggest that R2787H variant could have potential functional impact. Our approach might be useful for evaluation of BRCA unclassified variants. However additional functional analyzes may provide appropriate assessment to classify such variants. PMID:27211102

  8. BRCA2-deficient sarcomatoid mammary tumors exhibit multidrug resistance.

    Science.gov (United States)

    Jaspers, Janneke E; Sol, Wendy; Kersbergen, Ariena; Schlicker, Andreas; Guyader, Charlotte; Xu, Guotai; Wessels, Lodewyk; Borst, Piet; Jonkers, Jos; Rottenberg, Sven

    2015-02-15

    Pan- or multidrug resistance is a central problem in clinical oncology. Here, we use a genetically engineered mouse model of BRCA2-associated hereditary breast cancer to study drug resistance to several types of chemotherapy and PARP inhibition. We found that multidrug resistance was strongly associated with an EMT-like sarcomatoid phenotype and high expression of the Abcb1b gene, which encodes the drug efflux transporter P-glycoprotein. Inhibition of P-glycoprotein could partly resensitize sarcomatoid tumors to the PARP inhibitor olaparib, docetaxel, and doxorubicin. We propose that multidrug resistance is a multifactorial process and that mouse models are useful to unravel this. PMID:25511378

  9. The Icelandic founder mutation BRCA2 999del5: analysis of expression

    International Nuclear Information System (INIS)

    A founder mutation in the BRCA2 gene (BRCA2 999del5) accounts for 7–8% of female breast cancers and for 40% of male breast cancers in Iceland. If expressed, the mutant gene would encode a protein consisting of the first 256 amino acids of the BRCA2 protein. The purpose of this study was to determine whether this mutant protein is produced in heterozygous individuals and, if so, what might be the functional consequences of mutant protein production. The presence of BRCA2 999del5 transcripts in fibroblasts from heterozygous individuals was assayed by cDNA synthesis and sequencing. The potential protein-coding portion of BRCA2 999del5 was cloned into the pIND(SP1)/V5-His vector and expressed in COS7 cells. The presence of the mutant protein in cell lysates from heterozygous fibroblasts and from COS7 cells was tested by a number of methods including immunoprecipitation, affinity purification with nickel-coated agarose beads, Western blotting and ELISA, using antibodies to the N-terminal end of BRCA2, antiserum specific for the 16 nonrelevant amino acids at the carboxyl end and antibodies to fusion partners of recombinant proteins. The frequency of the BRCA2 999del5 transcript in heterozygous fibroblasts was about one-fifth of the wild-type transcript; however, no mutant protein could be detected. Overexpression of BRCA2 999del5 mRNA in COS7 cells failed to produce a mutant protein unless degradation by proteasomes was blocked. Our results show that the protein product of BRCA2 999del5 is extremely unstable. Therefore, an increase in breast cancer risk in BRCA2 999del5 carriers is due to haploinsufficiency at the BRCA2 locus

  10. Effects of BRCA2 deficiency on telomere recombination in non-ALT and ALT cells

    Directory of Open Access Journals (Sweden)

    Sapir Ester

    2011-12-01

    Full Text Available Abstract Background Recent studies suggest that BRCA2 affects telomere maintenance. Interestingly, anti cancer treatments that involve BRCA2 and telomerase individually are currently being explored. In the light of the above recent studies their combinatorial targeting may be justified in the development of future treatments. In order to investigate effects of BRCA2 that can be explored for this combinatorial targeting we focused on the analysis of recombination rates at telomeres by monitoring T-SCEs (Telomere Sister Chromatid Exchanges. Results We observed a significant increase in T-SCE frequencies in four BRCA2 defective human cell lines thus suggesting that BRCA2 suppresses recombination at telomeres. To test this hypothesis further we analyzed T-SCE frequencies in a set of Chinese hamster cell lines with or without functional BRCA2. Our results indicate that introduction of functional BRCA2 normalizes frequencies of T-SCEs thus supporting the notion that BRCA2 suppresses recombination at telomeres. Given that ALT (Alternative Lengthening of Telomeres positive cells maintain telomeres by recombination we investigated the effect of BRCA2 depletion in these cells. Our results show that this depletion causes a dramatic reduction in T-SCE frequencies in ALT positive cells, but not in non-ALT cells. Conclusion BRCA2 suppresses recombination at telomeres in cells that maintain them by conventional mechanisms. Furthermore, BRCA2 depletion in ALT positive cells reduces high levels of T-SCEs normally found in these cells. Our results could be potentially important for refining telomerase-based anti-cancer therapies.

  11. Interaction with PALB2 Is Essential for Maintenance of Genomic Integrity by BRCA2.

    Science.gov (United States)

    Hartford, Suzanne A; Chittela, Rajanikant; Ding, Xia; Vyas, Aradhana; Martin, Betty; Burkett, Sandra; Haines, Diana C; Southon, Eileen; Tessarollo, Lino; Sharan, Shyam K

    2016-08-01

    Human breast cancer susceptibility gene, BRCA2, encodes a 3418-amino acid protein that is essential for maintaining genomic integrity. Among the proteins that physically interact with BRCA2, Partner and Localizer of BRCA2 (PALB2), which binds to the N-terminal region of BRCA2, is vital for its function by facilitating its subnuclear localization. A functional redundancy has been reported between this N-terminal PALB2-binding domain and the C-terminal DNA-binding domain of BRCA2, which undermines the relevance of the interaction between these two proteins. Here, we describe a genetic approach to examine the functional significance of the interaction between BRCA2 and PALB2 by generating a knock-in mouse model of Brca2 carrying a single amino acid change (Gly25Arg, Brca2G25R) that disrupts this interaction. In addition, we have combined Brca2G25R homozygosity as well as hemizygosity with Palb2 and Trp53 heterozygosity to generate an array of genotypically and phenotypically distinct mouse models. Our findings reveal defects in body size, fertility, meiotic progression, and genome stability, as well as increased tumor susceptibility in these mice. The severity of the phenotype increased with a decrease in the interaction between BRCA2 and PALB2, highlighting the significance of this interaction. In addition, our findings also demonstrate that hypomorphic mutations such as Brca2G25R have the potential to be more detrimental than the functionally null alleles by increasing genomic instability to a level that induces tumorigenesis, rather than apoptosis. PMID:27490902

  12. Tamoxifen and Risk of Contralateral Breast Cancer for BRCA1 and BRCA2 Mutation Carriers

    DEFF Research Database (Denmark)

    Phillips, Kelly-Anne; Milne, Roger L; Rookus, Matti A;

    2013-01-01

    To determine whether adjuvant tamoxifen treatment for breast cancer (BC) is associated with reduced contralateral breast cancer (CBC) risk for BRCA1 and/or BRCA2 mutation carriers.......To determine whether adjuvant tamoxifen treatment for breast cancer (BC) is associated with reduced contralateral breast cancer (CBC) risk for BRCA1 and/or BRCA2 mutation carriers....

  13. Molecular biology in radiation oncology. Radiation oncology perspective of BRCA1 and BRCA2

    International Nuclear Information System (INIS)

    The breast cancer susceptibility genes, BRCA1 and BRCA2, are used to illustrate the application of molecular biology to clinical radiation oncology. Identified by linkage analysis and cloned, the structure of the genes and the numerous mutations are determined by molecular biology techniques that examine the structure of the DNA and the proteins made by the normal and mutant alleles. Mutations in the non-transcribed portion of the gene will not be found in protein structure assays and may be important in gene function. In addition to potential deleterious mutations, normal polymorphisms of the gene will also be detected, therefore not all differences in gene sequence may represent important mutations, a finding that complicates genetic screening and counseling. The localization of the protein in the nucleus, the expression in relation to cell cycle and the association with RAD51 led to the discovery that the two BRCA genes may be involved in transcriptional regulation and DNA repair. The defect in DNA repair can increase radiosensitivity which might improve local control using breast-conserving treatment in a tumor which is homozygous for the loss of the gene (i.e., BRCA1 and BRCA2 are tumor suppressor genes). This is supported by the early reports of a high rate of local control with breast-conserving therapy. Nonetheless, this radiosensitivity theoretically may also lead to increased susceptibility to carcinogenic effects in surviving cells, a finding that might not be observed for decades. The susceptibility to radiation-induced DNA damage appears also to make the cells more sensitive to chemotherapy. Understanding the role of the normal BRCA genes in DNA repair might help define a novel mechanism for radiation sensitization by interfering with the normal gene function using a variety of molecular or biochemical therapies

  14. Molecular biology in radiation oncology. Radiation oncology perspective of BRCA1 and BRCA2

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, C.N. [Harvard Medical School (United States). Joint Center for Radiation Therapy

    1999-07-01

    The breast cancer susceptibility genes, BRCA1 and BRCA2, are used to illustrate the application of molecular biology to clinical radiation oncology. Identified by linkage analysis and cloned, the structure of the genes and the numerous mutations are determined by molecular biology techniques that examine the structure of the DNA and the proteins made by the normal and mutant alleles. Mutations in the non-transcribed portion of the gene will not be found in protein structure assays and may be important in gene function. In addition to potential deleterious mutations, normal polymorphisms of the gene will also be detected, therefore not all differences in gene sequence may represent important mutations, a finding that complicates genetic screening and counseling. The localization of the protein in the nucleus, the expression in relation to cell cycle and the association with RAD51 led to the discovery that the two BRCA genes may be involved in transcriptional regulation and DNA repair. The defect in DNA repair can increase radiosensitivity which might improve local control using breast-conserving treatment in a tumor which is homozygous for the loss of the gene (i.e., BRCA1 and BRCA2 are tumor suppressor genes). This is supported by the early reports of a high rate of local control with breast-conserving therapy. Nonetheless, this radiosensitivity theoretically may also lead to increased susceptibility to carcinogenic effects in surviving cells, a finding that might not be observed for decades. The susceptibility to radiation-induced DNA damage appears also to make the cells more sensitive to chemotherapy. Understanding the role of the normal BRCA genes in DNA repair might help define a novel mechanism for radiation sensitization by interfering with the normal gene function using a variety of molecular or biochemical therapies.

  15. Hyperthermia adds to trabectedin effectiveness and thermal enhancement is associated with BRCA2 degradation and impairment of DNA homologous recombination repair.

    Science.gov (United States)

    Harnicek, Dominique; Kampmann, Eric; Lauber, Kirsten; Hennel, Roman; Cardoso Martins, Ana Sofia; Guo, Yang; Belka, Claus; Mörtl, Simone; Gallmeier, Eike; Kanaar, Roland; Mansmann, Ulrich; Hucl, Tomas; Lindner, Lars H; Hiddemann, Wolfgang; Issels, Rolf D

    2016-07-15

    The tetrahydroisoquinoline trabectedin is a marine compound with approved activity against human soft-tissue sarcoma. It exerts antiproliferative activity mainly by specific binding to the DNA and inducing DNA double-strand breaks (DSB). As homologous recombination repair (HRR)-deficient tumors are more susceptible to trabectedin, hyperthermia-mediated on-demand induction of HRR deficiency represents a novel and promising strategy to boost trabectedin treatment. For the first time, we demonstrate enhancement of trabectedin effectiveness in human sarcoma cell lines by heat and characterize cellular events and molecular mechanisms related to heat-induced effects. Hyperthermic temperatures (41.8 or 43°C) enhanced significantly trabectedin-related clonogenic cell death and G2/M cell cycle arrest followed by cell type-dependent induction of apoptosis or senescence. Heat combination increased accumulation of γH2AX foci as key marker of DSBs. Expression of BRCA2 protein, an integral protein of the HRR machinery, was significantly decreased by heat. Consequently, recruitment of downstream RAD51 to γH2AX-positive repair foci was almost abolished indicating relevant impairment of HRR by heat. Accordingly, enhancement of trabectedin effectiveness was significantly augmented in BRCA2-proficient cells by hyperthermia and alleviated in BRCA2 knockout or siRNA-transfected BRCA2 knockdown cells. In peripheral blood mononuclear cells isolated from sarcoma patients, increased numbers of nuclear γH2AX foci were detected after systemic treatment with trabectedin and hyperthermia of the tumor region. The findings establish BRCA2 degradation by heat as a key factor for a novel treatment strategy that allows targeted chemosensitization to trabectedin and other DNA damaging antitumor drugs by on-demand induction of HRR deficiency. PMID:26933761

  16. Fine-Scale Mapping at 9p22.2 Identifies Candidate Causal Variants That Modify Ovarian Cancer Risk in BRCA1 and BRCA2 Mutation Carriers

    Science.gov (United States)

    Vigorito, Elena; Kuchenbaecker, Karoline B.; Beesley, Jonathan; Adlard, Julian; Agnarsson, Bjarni A.; Andrulis, Irene L.; Arun, Banu K.; Barjhoux, Laure; Belotti, Muriel; Benitez, Javier; Berger, Andreas; Bojesen, Anders; Bonanni, Bernardo; Brewer, Carole; Caldes, Trinidad; Caligo, Maria A.; Campbell, Ian; Chan, Salina B.; Claes, Kathleen B. M.; Cohn, David E.; Cook, Jackie; Daly, Mary B.; Damiola, Francesca; Davidson, Rosemarie; de Pauw, Antoine; Delnatte, Capucine; Diez, Orland; Domchek, Susan M.; Dumont, Martine; Durda, Katarzyna; Dworniczak, Bernd; Easton, Douglas F.; Eccles, Diana; Edwinsdotter Ardnor, Christina; Eeles, Ros; Ejlertsen, Bent; Ellis, Steve; Evans, D. Gareth; Feliubadalo, Lidia; Fostira, Florentia; Foulkes, William D.; Friedman, Eitan; Frost, Debra; Gaddam, Pragna; Ganz, Patricia A.; Garber, Judy; Garcia-Barberan, Vanesa; Gauthier-Villars, Marion; Gehrig, Andrea; Gerdes, Anne-Marie; Giraud, Sophie; Godwin, Andrew K.; Goldgar, David E.; Hake, Christopher R.; Hansen, Thomas V. O.; Healey, Sue; Hodgson, Shirley; Hogervorst, Frans B. L.; Houdayer, Claude; Hulick, Peter J.; Imyanitov, Evgeny N.; Isaacs, Claudine; Izatt, Louise; Izquierdo, Angel; Jacobs, Lauren; Jakubowska, Anna; Janavicius, Ramunas; Jaworska-Bieniek, Katarzyna; Jensen, Uffe Birk; John, Esther M.; Vijai, Joseph; Karlan, Beth Y.; Kast, Karin; Investigators, KConFab; Khan, Sofia; Kwong, Ava; Laitman, Yael; Lester, Jenny; Lesueur, Fabienne; Liljegren, Annelie; Lubinski, Jan; Mai, Phuong L.; Manoukian, Siranoush; Mazoyer, Sylvie; Meindl, Alfons; Mensenkamp, Arjen R.; Montagna, Marco; Nathanson, Katherine L.; Neuhausen, Susan L.; Nevanlinna, Heli; Niederacher, Dieter; Olah, Edith; Olopade, Olufunmilayo I.; Ong, Kai-ren; Osorio, Ana; Park, Sue Kyung; Paulsson-Karlsson, Ylva; Pedersen, Inge Sokilde; Peissel, Bernard; Peterlongo, Paolo; Pfeiler, Georg; Phelan, Catherine M.; Piedmonte, Marion; Poppe, Bruce; Pujana, Miquel Angel; Radice, Paolo; Rennert, Gad; Rodriguez, Gustavo C.; Rookus, Matti A.; Ross, Eric A.; Schmutzler, Rita Katharina; Simard, Jacques; Singer, Christian F.; Slavin, Thomas P.; Soucy, Penny; Southey, Melissa; Steinemann, Doris; Stoppa-Lyonnet, Dominique; Sukiennicki, Grzegorz; Sutter, Christian; Szabo, Csilla I.; Tea, Muy-Kheng; Teixeira, Manuel R.; Teo, Soo-Hwang; Terry, Mary Beth; Thomassen, Mads; Tibiletti, Maria Grazia; Tihomirova, Laima; Tognazzo, Silvia; van Rensburg, Elizabeth J.; Varesco, Liliana; Varon-Mateeva, Raymonda; Vratimos, Athanassios; Weitzel, Jeffrey N.; McGuffog, Lesley; Kirk, Judy; Toland, Amanda Ewart; Hamann, Ute; Lindor, Noralane; Ramus, Susan J.; Greene, Mark H.; Couch, Fergus J.; Offit, Kenneth; Pharoah, Paul D. P.; Chenevix-Trench, Georgia; Antoniou, Antonis C.

    2016-01-01

    Population-based genome wide association studies have identified a locus at 9p22.2 associated with ovarian cancer risk, which also modifies ovarian cancer risk in BRCA1 and BRCA2 mutation carriers. We conducted fine-scale mapping at 9p22.2 to identify potential causal variants in BRCA1 and BRCA2 mutation carriers. Genotype data were available for 15,252 (2,462 ovarian cancer cases) BRCA1 and 8,211 (631 ovarian cancer cases) BRCA2 mutation carriers. Following genotype imputation, ovarian cancer associations were assessed for 4,873 and 5,020 SNPs in BRCA1 and BRCA 2 mutation carriers respectively, within a retrospective cohort analytical framework. In BRCA1 mutation carriers one set of eight correlated candidate causal variants for ovarian cancer risk modification was identified (top SNP rs10124837, HR: 0.73, 95%CI: 0.68 to 0.79, p-value 2× 10−16). These variants were located up to 20 kb upstream of BNC2. In BRCA2 mutation carriers one region, up to 45 kb upstream of BNC2, and containing 100 correlated SNPs was identified as candidate causal (top SNP rs62543585, HR: 0.69, 95%CI: 0.59 to 0.80, p-value 1.0 × 10−6). The candidate causal in BRCA1 mutation carriers did not include the strongest associated variant at this locus in the general population. In sum, we identified a set of candidate causal variants in a region that encompasses the BNC2 transcription start site. The ovarian cancer association at 9p22.2 may be mediated by different variants in BRCA1 mutation carriers and in the general population. Thus, potentially different mechanisms may underlie ovarian cancer risk for mutation carriers and the general population. PMID:27463617

  17. Fine-Scale Mapping at 9p22.2 Identifies Candidate Causal Variants That Modify Ovarian Cancer Risk in BRCA1 and BRCA2 Mutation Carriers.

    Science.gov (United States)

    Vigorito, Elena; Kuchenbaecker, Karoline B; Beesley, Jonathan; Adlard, Julian; Agnarsson, Bjarni A; Andrulis, Irene L; Arun, Banu K; Barjhoux, Laure; Belotti, Muriel; Benitez, Javier; Berger, Andreas; Bojesen, Anders; Bonanni, Bernardo; Brewer, Carole; Caldes, Trinidad; Caligo, Maria A; Campbell, Ian; Chan, Salina B; Claes, Kathleen B M; Cohn, David E; Cook, Jackie; Daly, Mary B; Damiola, Francesca; Davidson, Rosemarie; Pauw, Antoine de; Delnatte, Capucine; Diez, Orland; Domchek, Susan M; Dumont, Martine; Durda, Katarzyna; Dworniczak, Bernd; Easton, Douglas F; Eccles, Diana; Edwinsdotter Ardnor, Christina; Eeles, Ros; Ejlertsen, Bent; Ellis, Steve; Evans, D Gareth; Feliubadalo, Lidia; Fostira, Florentia; Foulkes, William D; Friedman, Eitan; Frost, Debra; Gaddam, Pragna; Ganz, Patricia A; Garber, Judy; Garcia-Barberan, Vanesa; Gauthier-Villars, Marion; Gehrig, Andrea; Gerdes, Anne-Marie; Giraud, Sophie; Godwin, Andrew K; Goldgar, David E; Hake, Christopher R; Hansen, Thomas V O; Healey, Sue; Hodgson, Shirley; Hogervorst, Frans B L; Houdayer, Claude; Hulick, Peter J; Imyanitov, Evgeny N; Isaacs, Claudine; Izatt, Louise; Izquierdo, Angel; Jacobs, Lauren; Jakubowska, Anna; Janavicius, Ramunas; Jaworska-Bieniek, Katarzyna; Jensen, Uffe Birk; John, Esther M; Vijai, Joseph; Karlan, Beth Y; Kast, Karin; Investigators, KConFab; Khan, Sofia; Kwong, Ava; Laitman, Yael; Lester, Jenny; Lesueur, Fabienne; Liljegren, Annelie; Lubinski, Jan; Mai, Phuong L; Manoukian, Siranoush; Mazoyer, Sylvie; Meindl, Alfons; Mensenkamp, Arjen R; Montagna, Marco; Nathanson, Katherine L; Neuhausen, Susan L; Nevanlinna, Heli; Niederacher, Dieter; Olah, Edith; Olopade, Olufunmilayo I; Ong, Kai-Ren; Osorio, Ana; Park, Sue Kyung; Paulsson-Karlsson, Ylva; Pedersen, Inge Sokilde; Peissel, Bernard; Peterlongo, Paolo; Pfeiler, Georg; Phelan, Catherine M; Piedmonte, Marion; Poppe, Bruce; Pujana, Miquel Angel; Radice, Paolo; Rennert, Gad; Rodriguez, Gustavo C; Rookus, Matti A; Ross, Eric A; Schmutzler, Rita Katharina; Simard, Jacques; Singer, Christian F; Slavin, Thomas P; Soucy, Penny; Southey, Melissa; Steinemann, Doris; Stoppa-Lyonnet, Dominique; Sukiennicki, Grzegorz; Sutter, Christian; Szabo, Csilla I; Tea, Muy-Kheng; Teixeira, Manuel R; Teo, Soo-Hwang; Terry, Mary Beth; Thomassen, Mads; Tibiletti, Maria Grazia; Tihomirova, Laima; Tognazzo, Silvia; van Rensburg, Elizabeth J; Varesco, Liliana; Varon-Mateeva, Raymonda; Vratimos, Athanassios; Weitzel, Jeffrey N; McGuffog, Lesley; Kirk, Judy; Toland, Amanda Ewart; Hamann, Ute; Lindor, Noralane; Ramus, Susan J; Greene, Mark H; Couch, Fergus J; Offit, Kenneth; Pharoah, Paul D P; Chenevix-Trench, Georgia; Antoniou, Antonis C

    2016-01-01

    Population-based genome wide association studies have identified a locus at 9p22.2 associated with ovarian cancer risk, which also modifies ovarian cancer risk in BRCA1 and BRCA2 mutation carriers. We conducted fine-scale mapping at 9p22.2 to identify potential causal variants in BRCA1 and BRCA2 mutation carriers. Genotype data were available for 15,252 (2,462 ovarian cancer cases) BRCA1 and 8,211 (631 ovarian cancer cases) BRCA2 mutation carriers. Following genotype imputation, ovarian cancer associations were assessed for 4,873 and 5,020 SNPs in BRCA1 and BRCA 2 mutation carriers respectively, within a retrospective cohort analytical framework. In BRCA1 mutation carriers one set of eight correlated candidate causal variants for ovarian cancer risk modification was identified (top SNP rs10124837, HR: 0.73, 95%CI: 0.68 to 0.79, p-value 2× 10-16). These variants were located up to 20 kb upstream of BNC2. In BRCA2 mutation carriers one region, up to 45 kb upstream of BNC2, and containing 100 correlated SNPs was identified as candidate causal (top SNP rs62543585, HR: 0.69, 95%CI: 0.59 to 0.80, p-value 1.0 × 10-6). The candidate causal in BRCA1 mutation carriers did not include the strongest associated variant at this locus in the general population. In sum, we identified a set of candidate causal variants in a region that encompasses the BNC2 transcription start site. The ovarian cancer association at 9p22.2 may be mediated by different variants in BRCA1 mutation carriers and in the general population. Thus, potentially different mechanisms may underlie ovarian cancer risk for mutation carriers and the general population. PMID:27463617

  18. Structure-mediated nanoscopy

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Bañas, Andrew Rafael; Aabo, Thomas;

    2013-01-01

    optical trapping handles for convenient mechanical control using only optical forces [6]. These microstructures can be effectively handled with simultaneous top- and side-view on our BioPhotonics Workstation to carry out proof-of-principle experiments illustrating the six-degree-of-freedom optical...... structures with built-in waveguides for us, we were able to put the idea of optically steerable freestanding waveguides – coined: wave-guided optical waveguides - to the test using our BioPhotonics Workstation [7]. We also proposed designing micro-structures for so-called structure-mediated access to the...

  19. Brca2 and Trp53 deficiency cooperate in the progression of mouse prostate tumourigenesis.

    Directory of Open Access Journals (Sweden)

    Jeffrey C Francis

    2010-06-01

    Full Text Available Epidemiological studies have shown that one of the strongest risk factors for prostate cancer is a family history of the disease, suggesting that inherited factors play a major role in prostate cancer susceptibility. Germline mutations in BRCA2 predispose to breast and ovarian cancer with its predominant tumour suppressor function thought to be the repair of DNA double-strand breaks. BRCA2 has also been implicated in prostate cancer etiology, but it is unclear the impact that mutations in this gene have on prostate tumourigenesis. Here we have undertaken a genetic analysis in the mouse to determine the role of Brca2 in the adult prostate. We show that deletion of Brca2 specifically in prostate epithelia results in focal hyperplasia and low-grade prostate intraepithelial neoplasia (PIN in animals over 12 months of age. Simultaneous deletion of Brca2 and the tumour suppressor Trp53 in prostate epithelia gave rise to focal hyperplasia and atypical cells at 6 months, leading to high-grade PIN in animals from 12 months. Epithelial cells in these lesions show an increase in DNA damage and have higher levels of proliferation, but also elevated apoptosis. Castration of Brca2;Trp53 mutant animals led to regression of PIN lesions, but atypical cells persisted that continued to proliferate and express nuclear androgen receptor. This study provides evidence that Brca2 can act as a tumour suppressor in the prostate, and the model we describe should prove useful in the development of new therapeutic approaches.

  20. VEGFR3 Inhibition Chemosensitizes Ovarian Cancer Stemlike Cells through Down-Regulation of BRCA1 and BRCA2

    Directory of Open Access Journals (Sweden)

    Jaeyoung Lim

    2014-04-01

    Full Text Available In ovarian cancer, loss of BRCA gene expression in tumors is associated with improved response to chemotherapy and increased survival. A means to pharmacologically downregulate BRCA gene expression could improve the outcomes of patients with BRCA wild-type tumors. We report that vascular endothelial growth factor receptor 3 (VEGFR3 inhibition in ovarian cancer cells is associated with decreased levels of both BRCA1 and BRCA2. Inhibition of VEGFR3 in ovarian tumor cells was associated with growth arrest. CD133+ ovarian cancer stemlike cells were preferentially susceptible to VEGFR3-mediated growth inhibition. VEGFR3 inhibition–mediated down-regulation of BRCA gene expression reversed chemotherapy resistance and restored chemosensitivity in resistant cell lines in which a BRCA2 mutation had reverted to wild type. Finally, we demonstrate that tumor-associated macrophages are a primary source of VEGF-C in the tumor microenvironment. Our studies suggest that VEGFR3 inhibition may be a pharmacologic means to downregulate BRCA genes and improve the outcomes of patients with BRCA wild-type tumors.

  1. Clues to the Function of the Tumour Susceptibility Gene BRCA2

    Directory of Open Access Journals (Sweden)

    Simon A. Gayther

    1998-01-01

    Full Text Available The breast cancer susceptibility gene BRCA2 was isolated in 1995. BRCA2 is a large gene comprising 10,254 nucleotides and 26 coding exons. Neither the nucleotide nor the predicted protein sequences (comprising 3,418 amino acids have provided substantial clues about its function. As a result, researchers have been trying to elucidate the function using a combination of cell biological and biochemical methods and the construction of animal models using gene targeting in mice. Recent data suggest that BRCA2 may participate in pathways associated with recombination or double-strand DNA break repair and may act by either sensing or responding to DNA damage. In addition, there is evidence to suggest that BRCA2 functions in a manner similar to the previously isolated breast cancer susceptibility gene BRCA1.

  2. Low frequency of large genomic rearrangements of BRCA1 and BRCA2 in western Denmark

    DEFF Research Database (Denmark)

    Thomassen, Mads; Gerdes, Anne-Marie; Cruger, Dorthe; Jensen, Peter K A; Kruse, Torben A

    2006-01-01

    Germline mutations in BRCA1 and BRCA2 predispose female carriers to breast and ovarian cancer. The majority of mutations identified are small deletions or insertions or are nonsense mutations. Large genomic rearrangements in BRCA1 are found with varying frequencies in different populations, but...... BRCA2 rearrangements have not been investigated thoroughly. The objective in this study was to determine the frequency of large genomic rearrangements in BRCA1 and BRCA2 in a large group of Danish families with increased risk of breast and ovarian cancer. A total of 617 families previously tested...... negative for mutations involving few bases were screened with multiplex ligation-dependent probe amplification (MLPA). Two deletions in BRCA1 were identified in three families; no large rearrangements were detected in BRCA2. The large deletions constitute 3.8% of the BRCA1 mutations identified, which is...

  3. Women with BRCA1 and BRCA2 mutations survive ovarian cancer at higher rates

    Science.gov (United States)

    Results from a National Cancer Institute (NCI) sponsored multicenter study published in the Journal of the American Medical Association on January 25, 2012, provides strong evidence that BRCA1 and BRCA2 gene mutation carriers with ovarian cancer were more

  4. BRCA1 and BRCA2 protein expressions in an ovotestis of a 46, XX true hermaphrodite

    International Nuclear Information System (INIS)

    BRCA1 and BRCA2 breast cancer susceptibility genes encode proteins, the normal cellular functions of which are complex and multiple, and germ-line mutations in individuals predispose both to breast and to ovarian cancer. There is nevertheless substantial evidence linking BRCA1 and BRCA2 to homologous recombination and DNA repair, to transcriptional control and to tissue proliferation. There is controversy regarding the localization of BRCA1 and BRCA2 proteins to either nucleus or cytoplasm and whether the expression is present in premeiotic germ cells or can still be expressed in mitotic spermatogonia. We report herein an immunohistochemical study of BRCA1 and BRCA2 distribution in a rather unsual tissue (an ovotestis), which addresses this issue

  5. A BRCA2 mutation incorrectly mapped in the original BRCA2 reference sequence, is a common West Danish founder mutation disrupting mRNA splicing

    DEFF Research Database (Denmark)

    Thomassen, Mads; Pedersen, Inge Søkilde; Vogel, Ida;

    2011-01-01

    Inherited mutations in the tumor suppressor genes BRCA1 and BRCA2 predispose carriers to breast and ovarian cancer. The authors have identified a mutation in BRCA2, 7845+1G>A (c.7617+1G>A), not previously regarded as deleterious because of incorrect mapping of the splice junction in the originally......, loss of exon 15 in the final transcript interrupting the open reading frame was demonstrated. Furthermore, the mutation segregates with a cancer phenotype in 18 Danish families. By genetic analysis of more than 3,500 Danish breast/ovarian cancer risk families, the mutation was identified as the most...

  6. Will Chinese ovarian cancer patients benefit from knowing the BRCA2 mutation status?

    OpenAIRE

    Liu, Guo-Yan; Zhang, Wei

    2012-01-01

    In Western countries, the mutation status of the BRCA1 and BRCA2 genes is commonly determined for genetic counseling among members of families with a history of breast or ovarian cancer, especially for women of the Ashkenazi Jewish ethnicity. Recent studies in the Cancer Genome Atlas project have demonstrated that BRCA2 mutation carriers are more responsive to platinum-based chemotherapy among high-grade serous ovarian cancer patients. Thus, in Western countries, the mutation status of BRCA1 ...

  7. Dysfunctional telomeres in human BRCA2 mutated breast tumors and cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Bodvarsdottir, Sigridur K., E-mail: skb@hi.is [Cancer Research Laboratory, BioMedical Centre, Faculty of Medicine, University of Iceland, Vatnsmyrarvegi 16, 101 Reykjavik (Iceland); Steinarsdottir, Margret [Chromosome Laboratory, Department of Genetics and Molecular Medicine, Landspitali University Hospital, Reykjavik (Iceland); Bjarnason, Hordur; Eyfjord, Jorunn E. [Cancer Research Laboratory, BioMedical Centre, Faculty of Medicine, University of Iceland, Vatnsmyrarvegi 16, 101 Reykjavik (Iceland)

    2012-01-03

    In the present study the possible involvement of telomeres in chromosomal instability of breast tumors and cell lines from BRCA2 mutation carriers was examined. Breast tumors from BRCA2 mutation carriers showed significantly higher frequency of chromosome end-to-end fusions (CEFs) than tumors from non-carriers despite normal telomere DNA content. Frequent CEFs were also found in four different BRCA2 heterozygous breast epithelial cell lines, occasionally with telomere signal at the fusion point, indicating telomere capping defects. Extrachromosomal telomeric repeat (ECTR) DNA was frequently found scattered around metaphase chromosomes and interstitial telomere sequences (ITSs) were also common. Telomere sister chromatid exchanges (T-SCEs), characteristic of cells using alternative lengthening of telomeres (ALT), were frequently detected in all heterozygous BRCA2 cell lines as well as the two ALT positive cell lines tested. Even though T-SCE frequency was similar in BRCA2 heterozygous and ALT positive cell lines they differed in single telomere signal loss and ITSs. Chromatid type alterations were more prominent in the BRCA2 heterozygous cell lines that may have propensity for telomere based chromosome healing. Telomere dysfunction-induced foci (TIFs) formation, identified by co-localization of telomeres and {gamma}-H2AX, supported telomere associated DNA damage response in BRCA2 heterozygous cell lines. TIFs were found in interphase nuclei, at chromosome ends, ITSs and ECTR DNA. In conclusion, our results suggest that BRCA2 has an important role in telomere stabilization by repressing CEFs through telomere capping and the prevention of telomere loss by replication stabilization.

  8. BRCA1/BRCA2-deficient cells are sensitive to mitomycin C and tirapazamine

    International Nuclear Information System (INIS)

    Full text: BRCA1- and BRCA2- deficient cells have defective repair of double-strand breaks (DSBs) via homologous recombination (HR). The toxicity profiles of these cells is of interest in the treatment of breast and ovarian cancer arising in mutation carriers. We focused on Mitomycin C (MMC), which produces DNA interstrand crosslinks, and Tirapazamine (TPZ), which is activated by hypoxia, and inhibits DNA replication and topoisomerase II. BRCA1-deficient HCC1937 cells, derived from a breast cancer in a BRCA1 carrier, were compared to cells corrected with wild-type (wt) BRCA1. BRCA2-deficient Capan-1 cells, derived from a pancreatic cancer in a BRCA2 carrier, were compared to a wt BRCA2-corrected clone. Expressing the BRC4 peptide in MCF-7 cells disrupted the association of BRCA2 with Rad51, thereby inactivating the function of BRCA2. Clonogenic cell survival was measured in response to X-rays, MMC, and TPZ (under hypoxia). BRCA1- and BRCA2-deficient cells were moderately sensitive to X-rays, consistent with defective DSB repair. Sensitivity to MMC often reveals cells with a defect in HR, but also defines the phenotype of Fanconi anemia, which has no major HR defect. Both BRCA1 and BRCA2 deficiency resulted in marked MMC sensitivity. After 0.5μM MMC, survival was reduced >100-fold without wt BRCA1 and 10-fold in BRCA2-inactivated MCF-7 cells. Based on a screen of yeast mutants that showed HR-deficient yeast were sensitive to TPZ, TPZ hypersensitivity was also observed in BRCA1/2-deficient cells. After 5μM TPZ, wt BRCA1 survival was 0.3, whereas BRCA1-deficient survival was <0.001. Similarly, BRCA2-deficient Capan-1 cells showed a ∼100-fold increased sensitivity to TPZ. The marked sensitivity of BRCA-deficient cancer cells to MMC and TPZ has important implications for the optimum systemic therapy of these tumors in the clinic. The critical damage that leads to this marked sensitivity, and how it depends on HR, is the subject of ongoing studies

  9. BRCA1 and BRCA2 mutations in central and southern Italian patients

    International Nuclear Information System (INIS)

    Protein truncation test (PTT) and single-strand conformation polymorphism (SSCP) assay were used to scan the BRCA1 and BRCA2 genes in 136 unrelated Italian breast/ovarian cancer patients. In the sample tested, BRCA1 and BRCA2 equally contributed to site-specific breast cancer patients who reported one to two breast cancer-affected first-/ second-degree relative(s) or who were diagnosed before age 40 years in the absence of a family history of breast/ovarian cancer. BRCA1 and BRCA2 mutations were mostly found in patients with disease diagnosis before and after age 50 years, respectively. Moreover, in cases with familial clustering of site-specific breast cancer, BRCA1 mostly accounted for tumours diagnosed before age 40 years and BRCA2 for tumours diagnosed after age 50 years. The BRCA1 and BRCA2 mutation spectrum was consistent with a lack of significant founder effects in the sample of patients studied. Germline BRCA1 and BRCA2 mutations account for most hereditary breast/ovarian cancers and are associated with male breast cancer. Furthermore, constitutional mutations in these genes may occur in breast/ovarian cancer patients that do not meet stringent criteria of autosomal-dominant predisposition. The relevance of BRCA1 and BRCA2 mutations in such patients is still debated. We sought to determine the impact of BRCA1 and BRCA2 mutations in a population of patients from central and southern Italy. We analyzed the BRCA1 and BRCA2 coding regions in 136 unrelated probands: 117 females with breast/ovarian cancer and 19 males with breast cancer. This population of patients was mostly representative of cases who are at risk for hereditary susceptibility, but who do not meet stringent criteria of autosomal-dominant predisposition. Probands, subclassified as follows, were consecutively recruited depending on informed consent from patients attending breast cancer clinics in Rome and Naples. Selection criteria for females were as follows: breast cancer with breast cancer

  10. Role of BRCA2 mutation status on overall survival among breast cancer patients from Sardinia

    International Nuclear Information System (INIS)

    Germline mutations in BRCA1 or BRCA2 genes have been demonstrated to increase the risk of developing breast cancer. Conversely, the impact of BRCA mutations on prognosis and survival of breast cancer patients is still debated. In this study, we investigated the role of such mutations on breast cancer-specific survival among patients from North Sardinia. Among incident cases during the period 1997–2002, a total of 512 breast cancer patients gave their consent to undergo BRCA mutation screening by DHPLC analysis and automated DNA sequencing. The Hakulinen, Kaplan-Meier, and Cox regression methods were used for both relative survival assessment and statistical analysis. In our series, patients carrying a germline mutation in coding regions and splice boundaries of BRCA1 and BRCA2 genes were 48/512 (9%). Effect on overall survival was evaluated taking into consideration BRCA2 carriers, who represented the vast majority (44/48; 92%) of mutation-positive patients. A lower breast cancer-specific overall survival rate was observed in BRCA2 mutation carriers after the first two years from diagnosis. However, survival rates were similar in both groups after five years from diagnosis. No significant difference was found for age of onset, disease stage, and primary tumour histopathology between the two subsets. In Sardinian breast cancer population, BRCA2 was the most affected gene and the effects of BRCA2 germline mutations on patients' survival were demonstrated to vary within the first two years from diagnosis. After a longer follow-up observation, breast cancer-specific rates of death were instead similar for BRCA2 mutation carriers and non-carriers

  11. Mutation analysis of BRCA1 and BRCA2 cancer predisposition genes in radiation hypersensitive cancer patients

    International Nuclear Information System (INIS)

    Purpose: The dose intensity of radiotherapy (RT) used in cancer treatment is limited in rare individuals who display severe normal tissue reactions after standard RT treatments. Novel predictive assays are required to identify these individuals prior to treatment. The mechanisms responsible for such reactions are unknown, but may involve dysfunction of genes involved in the sensing and response of cells to DNA damage. The breast cancer susceptibility genes BRCA1 and BRCA2 are implicated in DNA damage repair and the control of genome stability. The purpose of this study was to determine if clinical radiation hypersensitivity is related to mutations of the BRCA1 and BRCA2 genes. Such information is of potential use in the clinical management of BRCA mutation carriers and their families. Methods and Materials: Twenty-two cancer patients who developed severe normal tissue reactions after RT were screened for mutations of BRCA1 and BRCA2, using various methods including protein truncation testing, direct DNA sequencing, and a PCR-based BRCA1 exon 13 duplication test. Results: No mutations were detected in the 22 patients tested, despite screening for the majority of commonly described types of mutations of BRCA1 and BRCA2. Conclusion: These early results suggest that genes other than BRCA1 and BRCA2 probably account for most cases of clinical radiation hypersensitivity, and that screening for mutations of BRCA1 and BRCA2 is unlikely to be useful in predicting response to radiotherapy. However, it has not been excluded that some BRCA1 or BRCA2 heterozygotes might experience unexpected RT toxicity; further BRCA mutation screening on radiation sensitive individuals is warranted

  12. Breast imaging findings in women with BRCA1- and BRCA2-associated breast carcinoma

    International Nuclear Information System (INIS)

    AIM: To document the breast imaging findings of women with BRCA1 and BRCA2-associated breast carcinoma. MATERIALS AND METHODS: Family history clinic records identified 18 BRCA1 and 10 BRCA2 cases who collectively were diagnosed with 27 invasive breast carcinomas and four ductal carcinoma in situ (DCIS) lesions. All underwent pre-operative imaging (29 mammogram and 22 ultrasound examinations). All invasive BRCA-associated breast carcinoma cases were compared with age-matched cases of sporadic breast carcinoma. RESULTS: Within the BRCA cases the age range was 26-62 years, mean 36 years. Two mammograms were normal and 27 (93%) abnormal. The most common mammographic features were defined mass (63%) and microcalcifications (37%). Thirty-four percent of women had a dense mammographic pattern, 59% mixed and 7% fatty. Ultrasound was performed in 22 patients and in 21 (95%) indicated a mass. This was classified as benign in 24%, indeterminate in 29% and malignant in 48%. Mammograms of BRCA1-associated carcinomas more frequently showed a defined mass compared with BRCA2-associated carcinomas, 72 versus 36% (73% control group) whilst mammograms of BRCA2-associated carcinomas more frequently showed microcalcification, 73 versus 12% (8% control group; p<0.001). Thirty-six percent of the BRCA2-associated carcinomas were pure DCIS while none of the BRCA1 associated carcinomas were pure DCIS (p=0.004). Of those patients undergoing regular mammographic screening, 100% of BRCA2-associated carcinomas were detected compared with 75% of BRCA1-associated carcinomas. CONCLUSION: These data suggest that the imaging findings of BRCA1 and BRCA2-associated carcinomas differ from each other and from age-matched cases of sporadic breast carcinoma

  13. Loss of nuclear BRCA1 protein staining in normal tissue cells derived from BRCA1 and BRCA2 mutation carriers

    International Nuclear Information System (INIS)

    Enhanced genomic instability has been recently reported in normal cells derived from BRCA1/2 mutation carriers when placed in vitro in non-physiological stress conditions. We present here original data which help to explain the observed genomic instability. Leucocytes from BRCA1/2 mutation carriers, sporadic breast cancer patients and controls were prepared for BRCA1 immunocytochemistry. We show that BRCA1 containing nuclear dot like structures are detectable in about 80% of the leucocytes from controls and sporadic breast cancer patients, but are absent in the majority of normal cells from BRCA1 as well as BRCA2 mutation carriers (also in their normal breast cells). Our results thus indicate that the genomic instability observed in normal cells from BRCA1 and BRCA2 mutation carriers is associated with a down-regulation of nuclear BRCA1 protein accumulation in the dot like structures. These results suggest in addition that immunocytochemical or alternative molecular screening strategies might help to identify women with a high risk for breast (ovarian) cancer even when the underlying genetic defect remains undetectable

  14. Loss of nuclear BRCA1 protein staining in normal tissue cells derived from BRCA1 and BRCA2 mutation carriers

    Energy Technology Data Exchange (ETDEWEB)

    Brakeleer, Sylvia de [Laboratory of Molecular Oncology (Department of Medical Oncology), UZ Brussel, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels (Belgium); Bogdani, Marika [Department of Experimental Pathology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels (Belgium); Greve, Jacques de [Laboratory of Molecular Oncology (Department of Medical Oncology), UZ Brussel, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels (Belgium); Familial Cancer Clinic, UZ Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium); Decock, Julie [Laboratory of Molecular Oncology (Department of Medical Oncology), UZ Brussel, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels (Belgium); Sermijn, Erica [Familial Cancer Clinic, UZ Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium); Bonduelle, Maryse [Familial Cancer Clinic, UZ Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium); Goelen, Guido [Familial Cancer Clinic, UZ Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium); Teugels, Erik [Laboratory of Molecular Oncology (Department of Medical Oncology), UZ Brussel, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels (Belgium) and Familial Cancer Clinic, UZ Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium)]. E-mail: eteugels@uzbrussel.be

    2007-06-01

    Enhanced genomic instability has been recently reported in normal cells derived from BRCA1/2 mutation carriers when placed in vitro in non-physiological stress conditions. We present here original data which help to explain the observed genomic instability. Leucocytes from BRCA1/2 mutation carriers, sporadic breast cancer patients and controls were prepared for BRCA1 immunocytochemistry. We show that BRCA1 containing nuclear dot like structures are detectable in about 80% of the leucocytes from controls and sporadic breast cancer patients, but are absent in the majority of normal cells from BRCA1 as well as BRCA2 mutation carriers (also in their normal breast cells). Our results thus indicate that the genomic instability observed in normal cells from BRCA1 and BRCA2 mutation carriers is associated with a down-regulation of nuclear BRCA1 protein accumulation in the dot like structures. These results suggest in addition that immunocytochemical or alternative molecular screening strategies might help to identify women with a high risk for breast (ovarian) cancer even when the underlying genetic defect remains undetectable.

  15. Double Heterozygosity of BRCA2 and STK11 in Familial Breast Cancer Detected by Exome Sequencing

    Directory of Open Access Journals (Sweden)

    Mojgan ATAEI-KACHOUEI

    2015-10-01

    Full Text Available Background: Germ-line mutations of BRCA1 and BRCA2 genes are responsible for approximately 25-30% of dominantly inherited familial breast cancers; still a big part of genetic component is unknown. The aim of this study was to investigate genetic causes of familial breast cancer in a pedigree with recessive pattern of inheritance.Methods: We applied exome sequencing as a useful approach in heterogeneous diseases gene identification in present study for familial breast cancer. Sanger sequencing was applied for validation and segregation analysis of mutations.Results: Here, we describe a family with three affected sisters of early-onset invasive ductal carcinoma due to heterozygous frame shift mutation rs80359352 in BRCA2 gene as the first report in Iranian patients in association with a novel missense SNP of STK11 (p.S422G. These mutations are inherited from their normal father.Conclusion: Despite apparent recessive pattern of inheritance a dominant gene (here BRCA2 can be involved in pathogenesis of hereditary breast cancer which can be explained by incomplete penetrance of BRCA2 mutations. Keywords: BRCA2, Familial breast cancer, rs80359352, STK11, Iran

  16. Nuclear localization of Rad51B is independent of BRCA2

    Energy Technology Data Exchange (ETDEWEB)

    Miller, K A; Hinz, J M; Yamada, A; Thompson, L H; Albala, J S

    2005-06-28

    Human Rad51 is critical for the maintenance of genome stability through its role in the repair of DNA double-strand breaks. Rad51B (Rad51L1/hRec2) is one of the five known paralogs of human Rad51 found in a multi-protein complex with three other Rad51 paralogs, Rad51C, Rad51D and Xrcc2. Examination of EGFP-Rad51B fusion protein in HeLa S3 cells and immunofluorescence in several human cell lines confirms the nuclear localization of Rad51B. This is the first report to detail putative interactions of a Rad51 paralog protein with BRCA2. Utilization of a BRCA2 mutant cell line, CAPAN-1 suggests that Rad51B localizes to the nucleus independent of BRCA2. Although both Rad51B and BRCA2 are clearly involved in the homologous recombinational repair pathway, Rad51B and BRCA2 do not appear to associate directly. Furthermore, mutations in the KKLK motif of Rad51B, amino acid residues 4-7, mislocalizes Rad51B to the cytoplasm suggesting that this is the nuclear localization signal for the Rad51B protein. Examination of wild-type EGFP-Rad51B fusion protein in mammalian cells deficient in Rad51C showed that Rad51B localizes to the nucleus independent of Rad51C; further suggesting that Rad51B, like Rad51C, contains its own nuclear localization signal.

  17. Non-catalytic Roles for XPG with BRCA1 and BRCA2 in Homologous Recombination and Genome Stability.

    Science.gov (United States)

    Trego, Kelly S; Groesser, Torsten; Davalos, Albert R; Parplys, Ann C; Zhao, Weixing; Nelson, Michael R; Hlaing, Ayesu; Shih, Brian; Rydberg, Björn; Pluth, Janice M; Tsai, Miaw-Sheue; Hoeijmakers, Jan H J; Sung, Patrick; Wiese, Claudia; Campisi, Judith; Cooper, Priscilla K

    2016-02-18

    XPG is a structure-specific endonuclease required for nucleotide excision repair, and incision-defective XPG mutations cause the skin cancer-prone syndrome xeroderma pigmentosum. Truncating mutations instead cause the neurodevelopmental progeroid disorder Cockayne syndrome, but little is known about how XPG loss results in this devastating disease. We identify XPG as a partner of BRCA1 and BRCA2 in maintaining genomic stability through homologous recombination (HRR). XPG depletion causes DNA double-strand breaks, chromosomal abnormalities, cell-cycle delays, defective HRR, inability to overcome replication fork stalling, and replication stress. XPG directly interacts with BRCA2, RAD51, and PALB2, and XPG depletion reduces their chromatin binding and subsequent RAD51 foci formation. Upstream in HRR, XPG interacts directly with BRCA1. Its depletion causes BRCA1 hyper-phosphorylation and persistent chromatin binding. These unexpected findings establish XPG as an HRR protein with important roles in genome stability and suggest how XPG defects produce severe clinical consequences including cancer and accelerated aging. PMID:26833090

  18. Missense polymorphisms in BRCA1 and BRCA2 and risk of breast and ovarian cancer

    DEFF Research Database (Denmark)

    Dombernowsky, Sarah Louise; Weischer, Maren; Freiberg, Jacob Johannes;

    2009-01-01

    PURPOSE: BRCA1 and BRCA2 are key tumor suppressors with a role in cellular DNA repair, genomic stability, and checkpoint control. Mutations in BRCA1 and BRCA2 often cause hereditary breast and ovarian cancer; however, missense polymorphisms in these genes pose a problem in genetic counseling, as...... and/or ovarian cancer. Therefore, genetic counseling of such families safely can disregard findings of these missense polymorphisms....... their impact on risk of breast and ovarian cancer is unclear. EXPERIMENTAL DESIGN: We resequenced BRCA1 and BRCA2 in 194 women with a familial history of breast and/or ovarian cancer and identified nine possibly biologically relevant polymorphisms (BRCA1 Gln356Arg, Pro871Leu, Glu1038Gly, Ser1613Gly, and...

  19. Distinct functions of BRCA1 and BRCA2 in double-strand break repair

    International Nuclear Information System (INIS)

    Individuals carrying BRCA mutations are predisposed to breast cancer. The BRCA1 and BRCA2 proteins are required for homologous recombination and DNA break repair, leading to the suggestion that they act in concert. However, direct evidence of a stable BRCA1/BRCA2 complex has not been demonstrated. Rather, the two proteins have been found as constituents of discrete, but perhaps nonexclusive complexes that are critical for repair. We discuss the interaction of BRCA1 with the BACH1 and BARD1 proteins, and suggest that the pleiotropic nature of mutations in BRCA1 may be associated with defects in protein–protein interactions. In contrast, the role of BRCA2 in DNA repair may be more defined by its direct interaction with the RAD51 recombinase

  20. A high-throughput protocol for mutation scanning of the BRCA1 and BRCA2 genes

    International Nuclear Information System (INIS)

    Detection of mutations by DNA sequencing can be facilitated by scanning methods to identify amplicons which may have mutations. Current scanning methods used for the detection of germline sequence variants are laborious as they require post-PCR manipulation. High resolution melting (HRM) is a cost-effective rapid screening strategy, which readily detects heterozygous variants by melting curve analysis of PCR products. It is well suited to screening genes such as BRCA1 and BRCA2 as germline pathogenic mutations in these genes are always heterozygous. Assays for the analysis of all coding regions and intron-exon boundaries of BRCA1 and BRCA2 were designed, and optimised. A final set of 94 assays which ran under identical amplification conditions were chosen for BRCA1 (36) and BRCA2 (58). Significant attention was placed on primer design to enable reproducible detection of mutations within the amplicon while minimising unnecessary detection of polymorphisms. Deoxyinosine residues were incorporated into primers that overlay intronic polymorphisms. Multiple 384 well plates were used to facilitate high throughput. 169 BRCA1 and 239 BRCA2 known sequence variants were used to test the amplicons. We also performed an extensive blinded validation of the protocol with 384 separate patient DNAs. All heterozygous variants were detected with the optimised assays. This is the first HRM approach to screen the entire coding region of the BRCA1 and BRCA2 genes using one set of reaction conditions in a multi plate 384 well format using specifically designed primers. The parallel screening of a relatively large number of samples enables better detection of sequence variants. HRM has the advantages of decreasing the necessary sequencing by more than 90%. This markedly reduced cost of sequencing will result in BRCA1 and BRCA2 mutation testing becoming accessible to individuals who currently do not undergo mutation testing because of the significant costs involved

  1. Evidence for a Chk2-BRCA1-BRCA2 pathway in controlling homologous recombination

    International Nuclear Information System (INIS)

    The BRCA2 protein is thought to play a role as a supportive protein for the assembly of Rad51 filaments at the sites of DNA damage or stalled DNA replication, and thereby facilitates the process of homologous recombination (HR). We provide direct evidence that the interaction of BRCA2 and Rad51, via the BRC repeat motifs of BRCA2, is the key to its function in HR. Furthermore, the BRCA2's role to facilitate HR is dependent on a replicating DNA template, closely linking the process of HR to DNA replication. To date, no other role for BRCA2 has been elucidated in-vivo. BRCA1, by contrast, has a complex series of functions including a supportive role in HR, a possible role in non-homologous recombination (NHR), transcriptional co-activation and E3 ubiquitin ligase activity. The protein undergoes extensive post-translational modification, principally by phosphorylation, in both S-phase and in response to DNA damage. We show that ATM-dependent modifications of BRCA1 are important for S-phase and G2/M checkpoints, but have no direct impact on DNA repair. However, a chk2 dependent modification of BRCA1 at serine-988, appears critical for the promotion of Rad51-dependent HR and the inhibition of Mre11/Rad50/NBS1- dependent repair. Direct modification of chk2 kinase activity, by over-expression of a kinase-dead chk2, results in an identical phenotype as seen with the S988A mutation of BRCA1. Taken together, these results suggest that a chk2-BRCA1-BRCA2 dependent pathway promotes error-free HR, suppresses error-prone NHR and thereby maintains genomic stability

  2. Functional assays for analysis of variants of uncertain significance in BRCA2

    DEFF Research Database (Denmark)

    Guidugli, Lucia; Carreira, Aura; Caputo, Sandrine M;

    2014-01-01

    Missense variants in the BRCA2 gene are routinely detected during clinical screening for pathogenic mutations in patients with a family history of breast and ovarian cancer. These subtle changes frequently remain of unknown clinical significance because of the lack of genetic information that may...... help establish a direct correlation with cancer predisposition. Therefore, alternative ways of predicting the pathogenicity of these variants are urgently needed. Since BRCA2 is a protein involved in important cellular mechanisms such as DNA repair, replication, and cell cycle control, functional...

  3. Novel de novo BRCA2 mutation in a patient with a family history of breast cancer

    DEFF Research Database (Denmark)

    Hansen, Thomas V O; Bisgaard, Marie Luise; Jønson, Lars;

    2008-01-01

    BACKGROUND: BRCA2 germ-line mutations predispose to breast and ovarian cancer. Mutations are widespread and unclassified splice variants are frequently encountered. We describe the parental origin and functional characterization of a novel de novo BRCA2 splice site mutation found in a patient...... whole blood. The paternity was determined by single nucleotide polymorphism (SNP) microarray analysis. Parental origin of the de novo mutation was determined by establishing mutation-SNP haplotypes by variant specific PCR, while de novo and mosaic status was investigated by sequencing of DNA from...

  4. BRCA1 and BRCA2 mutations in Danish families with hereditary breast and/or ovarian cancer

    DEFF Research Database (Denmark)

    Thomassen, Mads; Hansen, Thomas V O; Borg, Ake;

    2008-01-01

    A national study of BRCA1 and BRCA2 mutations in Danish HBOC (Hereditary Breast Ovarian Cancer) families revealed a total number of 322 mutation positive families, 206 (64%) BRCA1 and 116 (36%) BRCA2 positive families from a population of 5.5 million inhabitants. Seven hundred and twenty six muta...

  5. Large BRCA1 and BRCA2 genomic rearrangements in Danish high risk breast-ovarian cancer families

    DEFF Research Database (Denmark)

    Hansen, Thomas v O; Jønson, Lars; Albrechtsen, Anders;

    2009-01-01

    BRCA1 and BRCA2 germ-line mutations predispose to breast and ovarian cancer. Large genomic rearrangements of BRCA1 account for 0-36% of all disease causing mutations in various populations, while large genomic rearrangements in BRCA2 are more rare. We examined 642 East Danish breast and/or ovarian...

  6. Association between BRCA1 and BRCA2 mutations and survival in women with invasive epithelial ovarian cancer

    DEFF Research Database (Denmark)

    Bolton, Kelly L; Chenevix-Trench, Georgia; Goh, Cindy; Sadetzki, Siegal; Ramus, Susan J; Karlan, Beth Y; Lambrechts, Diether; Despierre, Evelyn; Barrowdale, Daniel; McGuffog, Lesley; Healey, Sue; Easton, Douglas F; Sinilnikova, Olga; Benítez, Javier; García, María J; Neuhausen, Susan; Gail, Mitchell H; Hartge, Patricia; Peock, Susan; Frost, Debra; Evans, D Gareth; Eeles, Rosalind; Godwin, Andrew K; Daly, Mary B; Kwong, Ava; Ma, Edmond S K; Lázaro, Conxi; Blanco, Ignacio; Montagna, Marco; D'Andrea, Emma; Nicoletto, Maria Ornella; Johnatty, Sharon E; Kjær, Susanne Krüger; Jensen, Allan; Høgdall, Estrid; Goode, Ellen L; Fridley, Brooke L; Loud, Jennifer T; Greene, Mark H; Mai, Phuong L; Chetrit, Angela; Lubin, Flora; Hirsh-Yechezkel, Galit; Glendon, Gord; Andrulis, Irene L; Toland, Amanda E; Senter, Leigha; Gore, Martin E; Gourley, Charlie; Michie, Caroline O; Song, Honglin; Tyrer, Jonathan; Whittemore, Alice S; McGuire, Valerie; Sieh, Weiva; Kristoffersson, Ulf; Olsson, Håkan; Borg, Åke; Levine, Douglas A; Steele, Linda; Beattie, Mary S; Chan, Salina; Nussbaum, Robert L; Moysich, Kirsten B; Gross, Jenny; Cass, Ilana; Walsh, Christine; Li, Andrew J; Leuchter, Ronald; Gordon, Ora; Garcia-Closas, Montserrat; Gayther, Simon A; Chanock, Stephen J; Antoniou, Antonis C; Pharoah, Paul D P

    2012-01-01

    Approximately 10% of women with invasive epithelial ovarian cancer (EOC) carry deleterious germline mutations in BRCA1 or BRCA2. A recent article suggested that BRCA2-related EOC was associated with an improved prognosis, but the effect of BRCA1 remains unclear....

  7. BRCA2 Polymorphic Stop Codon K3326X and the Risk of Breast, Prostate, and Ovarian Cancers

    DEFF Research Database (Denmark)

    Meeks, Huong D; Song, Honglin; Michailidou, Kyriaki;

    2016-01-01

    BACKGROUND: The K3326X variant in BRCA2 (BRCA2*c.9976A>T; p.Lys3326*; rs11571833) has been found to be associated with small increased risks of breast cancer. However, it is not clear to what extent linkage disequilibrium with fully pathogenic mutations might account for this association. There i...

  8. Will Chinese ovarian cancer patients benefit from knowing the BRCA2 mutation status?

    Institute of Scientific and Technical Information of China (English)

    Guo-Yan Liu; Wei Zhang

    2012-01-01

    In Western countries,the mutation status of the BRCA1 and BRCA2 genes is commonly determined for genetic counseling among members of families with a history of breast or ovarian cancer,especially for women of the Ashkenazi Jewish ethnicity.Recent studies in the Cancer Genome Atlas project have demonstrated that BRCA2 mutation carriers are more responsive to platinum-based chemotherapy among high-grade serous ovarian cancer patients.Thus,in Western countries,the mutation status of BRCA1 and BRCA2 is recognized to have an important value with which to assess cancer risk and therapeutic response.However,very limited studies of BRCA1 and BRCA2 mutations and their implications for counseling and therapeutic prediction have been conducted in China.Therefore,a potentially important genetic test that is technically simple has not benefited Chinese women with an increased risk of breast or ovarian cancer.This article summarizes the current progress in the study of BRCA1/2 mutation in China and recommends an increased effort in applying advances in genetic testing to the clinical management of Chinese patients with ovarian cancer.

  9. Breast cancer in a male-to-female transsexual patient with a BRCA2 mutation.

    Science.gov (United States)

    Corman, Vinciane; Potorac, Iulia; Manto, Florence; Dassy, Sarah; Segers, Karin; Thiry, Albert; Bours, Vincent; Daly, Adrian F; Beckers, Albert

    2016-05-01

    Breast cancer is rare in male patients. Certain predisposing factors, be they genetic (e.g., BRCA2 gene mutations) or hormonal (imbalance between estrogen and androgen levels), have been implicated in male breast cancer pathophysiology. Male-to-female (MtF) transsexualism is a condition that generally involves cross-sex hormone therapy. Anti-androgens and estrogens are used to mimic the female hormonal environment and induce the cross-sex secondary characteristics. In certain situations, the change in the hormonal milieu can be disadvantageous and favor the development of hormone-dependent pathologies, such as cancer. We report a case of a MtF transgender patient who developed breast cancer after 7 years of cross-sex hormonal therapy. The patient was found to be BRCA2 positive, and suffered recurrent disease. The patient was unaware of being a member of an established BRCA2 mutation-positive kindred. This represents the first case of a BRCA2 mutation predisposing to breast cancer in a MtF transgender patient. PMID:27000661

  10. Breast tumor characteristics of BRCA1 and BRCA2 gene mutation carriers on MRI

    NARCIS (Netherlands)

    Veltman, J.; Mann, R.; Kok, T.; Obdeijn, I. M.; Hoogerbrugge, N.; Blickman, J. G.; Boetes, C.

    2008-01-01

    The appearance of malignant lesions in BRCA1 and BRCA2 mutation carriers (BRCA-MCs) on mammography and magnetic resonance imaging (MRI) was evaluated. Thus, 29 BRCA-MCs with breast cancer were retrospectively evaluated and the results compared with an age, tumor size and tumor type matched control g

  11. Targeted prostate cancer screening in BRCA1 and BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Bancroft, Elizabeth K; Page, Elizabeth C; Castro, Elena;

    2014-01-01

    BACKGROUND: Men with germline breast cancer 1, early onset (BRCA1) or breast cancer 2, early onset (BRCA2) gene mutations have a higher risk of developing prostate cancer (PCa) than noncarriers. IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in ...

  12. Breast tumor characteristics of BRCA1 and BRCA2 gene mutation carriers on MRI

    NARCIS (Netherlands)

    J. Veltman; R. Mann; T. Kok (Theo); A.I.M. Obdeijn (Inge-Marie); N. Hoogerbrugge (Nicoline); J.G. Blickman; C. Boetes

    2008-01-01

    textabstractThe appearance of malignant lesions in BRCA1 and BRCA2 mutation carriers (BRCA-MCs) on mammography and magnetic resonance imaging (MRI) was evaluated. Thus, 29 BRCA-MCs with breast cancer were retrospectively evaluated and the results compared with an age, tumor size and tumor type match

  13. Breast conservation in BRCA1 or BRCA2 mutation carriers with early stage breast cancer

    International Nuclear Information System (INIS)

    The role of breast conservation therapy (limited surgery and irradiation of the breast with/without axilla) in the approximately 5% of breast cancer patients who harbour a germline mutation in BRCA1 or BRCA2, is a largely unexplored area and is seen by some as controversial. The relatively high cumulative risk of second primary cancers in such patients and concern about a possible decreased ability of mutation carriers to repair DNA damage caused by radiation has fuelled this controversy. Published studies of breast conservation therapy in carriers of a mutation in BRCA1 or BRCA2 are reviewed, with particular attention to their methodology. These studies have not demonstrated any increase in radiation sensitivity of normal tissues in mutation carriers, either in terms of increased early or late toxicity or tumourigenesis. Likewise, tumour sensitivity to radiotherapy, which might be expected based on the known functions of the BRCA1 and BRCA2 genes, has not been documented to date in mutation carriers. Further, methodologically rigorous studies of large numbers of breast cancer patients who carry a mutation in BRCA1 or BRCA2 are required to fully elucidate these issues. Copyright (2001) Blackwell Science Pty Ltd

  14. Refined histopathological predictors of BRCA1 and BRCA2 mutation status

    DEFF Research Database (Denmark)

    Spurdle, Amanda B; Couch, Fergus J; Parsons, Michael T;

    2014-01-01

    INTRODUCTION: The distribution of histopathological features of invasive breast tumors in BRCA1 or BRCA2 germline mutation carriers differs from that of individuals with no known mutation. Histopathological features thus have utility for mutation prediction, including statistical modeling to asse...

  15. Common Genetic Variants and Modification of Penetrance of BRCA2-Associated Breast Cancer

    Science.gov (United States)

    Guiducci, Candace; Segrè, Ayellet V.; McGee, Kate; McGuffog, Lesley; Kartsonaki, Christiana; Morrison, Jonathan; Healey, Sue; Sinilnikova, Olga M.; Stoppa-Lyonnet, Dominique; Mazoyer, Sylvie; Gauthier-Villars, Marion; Sobol, Hagay; Longy, Michel; Frenay, Marc; GEMO Study Collaborators; Hogervorst, Frans B. L.; Rookus, Matti A.; Collée, J. Margriet; Hoogerbrugge, Nicoline; van Roozendaal, Kees E. P.; Piedmonte, Marion; Rubinstein, Wendy; Nerenstone, Stacy; Van Le, Linda; Blank, Stephanie V.; Caldés, Trinidad; de la Hoya, Miguel; Nevanlinna, Heli; Aittomäki, Kristiina; Lazaro, Conxi; Blanco, Ignacio; Arason, Adalgeir; Johannsson, Oskar T.; Barkardottir, Rosa B.; Devilee, Peter; Olopade, Olofunmilayo I.; Neuhausen, Susan L.; Wang, Xianshu; Fredericksen, Zachary S.; Peterlongo, Paolo; Manoukian, Siranoush; Barile, Monica; Viel, Alessandra; Radice, Paolo; Phelan, Catherine M.; Narod, Steven; Rennert, Gad; Lejbkowicz, Flavio; Flugelman, Anath; Andrulis, Irene L.; Glendon, Gord; Ozcelik, Hilmi; Toland, Amanda E.; Montagna, Marco; D'Andrea, Emma; Friedman, Eitan; Laitman, Yael; Borg, Ake; Beattie, Mary; Ramus, Susan J.; Domchek, Susan M.; Nathanson, Katherine L.; Rebbeck, Tim; Spurdle, Amanda B.; Chen, Xiaoqing; Holland, Helene; John, Esther M.; Hopper, John L.; Buys, Saundra S.; Daly, Mary B.; Southey, Melissa C.; Terry, Mary Beth; Tung, Nadine; Overeem Hansen, Thomas V.; Nielsen, Finn C.; Greene, Mark I.; Mai, Phuong L.; Osorio, Ana; Durán, Mercedes; Andres, Raquel; Benítez, Javier; Weitzel, Jeffrey N.; Garber, Judy; Hamann, Ute; Peock, Susan; Cook, Margaret; Oliver, Clare; Frost, Debra; Platte, Radka; Evans, D. Gareth; Lalloo, Fiona; Eeles, Ros; Izatt, Louise; Walker, Lisa; Eason, Jacqueline; Barwell, Julian; Godwin, Andrew K.; Schmutzler, Rita K.; Wappenschmidt, Barbara; Engert, Stefanie; Arnold, Norbert; Gadzicki, Dorothea; Dean, Michael; Gold, Bert; Klein, Robert J.; Couch, Fergus J.; Chenevix-Trench, Georgia; Easton, Douglas F.; Daly, Mark J.; Antoniou, Antonis C.; Altshuler, David M.; Offit, Kenneth

    2010-01-01

    The considerable uncertainty regarding cancer risks associated with inherited mutations of BRCA2 is due to unknown factors. To investigate whether common genetic variants modify penetrance for BRCA2 mutation carriers, we undertook a two-staged genome-wide association study in BRCA2 mutation carriers. In stage 1 using the Affymetrix 6.0 platform, 592,163 filtered SNPs genotyped were available on 899 young (<40 years) affected and 804 unaffected carriers of European ancestry. Associations were evaluated using a survival-based score test adjusted for familial correlations and stratified by country of the study and BRCA2*6174delT mutation status. The genomic inflation factor (λ) was 1.011. The stage 1 association analysis revealed multiple variants associated with breast cancer risk: 3 SNPs had p-values<10−5 and 39 SNPs had p-values<10−4. These variants included several previously associated with sporadic breast cancer risk and two novel loci on chromosome 20 (rs311499) and chromosome 10 (rs16917302). The chromosome 10 locus was in ZNF365, which contains another variant that has recently been associated with breast cancer in an independent study of unselected cases. In stage 2, the top 85 loci from stage 1 were genotyped in 1,264 cases and 1,222 controls. Hazard ratios (HR) and 95% confidence intervals (CI) for stage 1 and 2 were combined and estimated using a retrospective likelihood approach, stratified by country of residence and the most common mutation, BRCA2*6174delT. The combined per allele HR of the minor allele for the novel loci rs16917302 was 0.75 (95% CI 0.66–0.86, ) and for rs311499 was 0.72 (95% CI 0.61–0.85, ). FGFR2 rs2981575 had the strongest association with breast cancer risk (per allele HR = 1.28, 95% CI 1.18–1.39, ). These results indicate that SNPs that modify BRCA2 penetrance identified by an agnostic approach thus far are limited to variants that also modify risk of sporadic BRCA2 wild-type breast cancer. PMID:21060860

  16. Common genetic variants and modification of penetrance of BRCA2-associated breast cancer.

    Directory of Open Access Journals (Sweden)

    Mia M Gaudet

    2010-10-01

    Full Text Available The considerable uncertainty regarding cancer risks associated with inherited mutations of BRCA2 is due to unknown factors. To investigate whether common genetic variants modify penetrance for BRCA2 mutation carriers, we undertook a two-staged genome-wide association study in BRCA2 mutation carriers. In stage 1 using the Affymetrix 6.0 platform, 592,163 filtered SNPs genotyped were available on 899 young (<40 years affected and 804 unaffected carriers of European ancestry. Associations were evaluated using a survival-based score test adjusted for familial correlations and stratified by country of the study and BRCA2*6174delT mutation status. The genomic inflation factor (λ was 1.011. The stage 1 association analysis revealed multiple variants associated with breast cancer risk: 3 SNPs had p-values<10(-5 and 39 SNPs had p-values<10(-4. These variants included several previously associated with sporadic breast cancer risk and two novel loci on chromosome 20 (rs311499 and chromosome 10 (rs16917302. The chromosome 10 locus was in ZNF365, which contains another variant that has recently been associated with breast cancer in an independent study of unselected cases. In stage 2, the top 85 loci from stage 1 were genotyped in 1,264 cases and 1,222 controls. Hazard ratios (HR and 95% confidence intervals (CI for stage 1 and 2 were combined and estimated using a retrospective likelihood approach, stratified by country of residence and the most common mutation, BRCA2*6174delT. The combined per allele HR of the minor allele for the novel loci rs16917302 was 0.75 (95% CI 0.66-0.86, and for rs311499 was 0.72 (95% CI 0.61-0.85, . FGFR2 rs2981575 had the strongest association with breast cancer risk (per allele HR = 1.28, 95% CI 1.18-1.39, . These results indicate that SNPs that modify BRCA2 penetrance identified by an agnostic approach thus far are limited to variants that also modify risk of sporadic BRCA2 wild-type breast cancer.

  17. Mutations in BRCA1 and BRCA2 Uruguayan families with breast / ovarian

    International Nuclear Information System (INIS)

    Germline mutations in BRCA1 and BRCA2 are associated with susceptibility hereditary to breast (CM) and ovarian cancer (OC). The proportion of high risk families carrying mutations in BRCA1 / 2 (20% -70%) and the spectrum of mutations are variable and dependent on the location and type of families studied. In this communication we update our results on the frequency and type of mutations in BRCA1 / 2 families in Uruguayan breast / ovarian cancer. Patients and methods. 39 selected families were included in the study from patients referred to the Unit of the Hospital de Clinicas Oncogene tics for genetic risk assessment and who had at least 3 cases of CM (at least one diagnosed before age 50) or 2 cases with any of the following sub: Parental transmittance, bilateral breast cancer, breast cancer male, ovarian cancer. Results. 8 8 families different mutations (20%), 6 were identified in BRCA1 and BRCA2 2, all resulting in premature termination codon. Regarding family history, 33 families had history of CM and 6 remaining history of CM and CO. Among the first 6 mutations diagnosed (Five in BRCA1 and one in BRCA2) and between the latter 2 mutations (1 in BRCA1 and 1 in BRCA2). Regarding the index cases, all BRCA2 mutations were detected in patients in whom the disease was diagnosed before the 50, 5 of them carrying CM and CO. The BRCA1 were found in a patient with CO diagnosed at age 55 and a patient with CM diagnosed before 50 years. Conclusions. The proportion of flamilies with BRCA1 / 2 is of agreement with that reported in previous studies involving selected families based on similar criteria, but the relative frequency of engagement

  18. BRCA1 and BRCA2 Unclassified Variants and Missense Polymorphisms in Algerian Breast/Ovarian Cancer Families

    Directory of Open Access Journals (Sweden)

    Farid Cherbal

    2012-01-01

    Full Text Available Background: BRCA1 and BRCA2 germline mutations predispose heterozygous carriers to hereditary breast/ovarian cancer. However, unclassified variants (UVs (variants with unknown clinical significance and missense polymorphisms in BRCA1 and BRCA2 genes pose a problem in genetic counseling, as their impact on risk of breast and ovarian cancer is still unclear. The objective of our study was to identify UVs and missense polymorphisms in Algerian breast/ovarian cancer patients and relatives tested previously for BRCA1 and BRCA2 genes germline mutations analysis.

  19. Recurrent germline mutations in BRCA1 and BRCA2 genes in high risk families in Israel.

    Science.gov (United States)

    Laitman, Yael; Simeonov, Monica; Herskovitz, Liron; Kushnir, Anya; Shimon-Paluch, Shani; Kaufman, Bella; Zidan, Jamal; Friedman, Eitan

    2012-06-01

    The spectrum of germline mutations among Jewish non Ashkenazi high risk breast/ovarian cancer families includes a few predominant mutations in BRCA1 (185delAG and Tyr978X) and BRCA2 (8765delAG). A few additional recurring mutations [A1708E, 981delAT, C61G (BRCA1) R2336P, and IVS2 + 1G > A (BRCA2)] have been reported in Jewish non Ashkenazi families. The 4153delA*BRCA1 C61G*BRCA1 and the 4075delGT*BRCA2 has been reported to recur in Russian/Polish non Jews and Ashkenazim, respectively. The rate of these recurring mutations has not been reported in Israeli high risk families. Genotyping for these recurring mutations by restriction enzyme digest and sequencing method was applied to high risk, predominantly cancer affected, unrelated Israeli individuals of Ashkenazi (n = 827), non Ashkenazi (n = 2,777), non Jewish Caucasians (n = 193), and 395 of mixed ethnicity. Jewish participants included 827 Ashkenazi, 804 Balkans, 847 North Africans, 234 Yemenites, and 892 Asians (Iraq and Iran). Age at diagnosis of breast cancer (median ± SD) (n = 2,484) was 47.2 ± 9.6 for all women participants. Males (n = 236) were also included, of whom 24 had breast cancer and 35 had pancreatic cancer. Overall, 8/282 (2.8%) of the Balkan cases carried the BRCA1*A1708E mutation, 4/180 (2.2%) the R2336P mutation, and 0/270 the IVS2 + 1G > A BRCA2 mutations, respectively. Of North Africans, 7/264 (2.65%) carried the BRCA1*981delAT mutation. The BRCA1*C61G mutation was detected in 3/269 Ashkenazi, non Ashkenazi, and non Jewish Russians; the BRCA1*Tyr978X mutation was detected in 23/3220 individuals of non Ashkenazi origin, exclusively of Asian ethnicity (23/892, 2.6% of the Asians tested). The BRCA1*4153delA mutation was noted in 2/285 non Jewish Caucasians, and none of the Ashkenazim (n = 500) carried the BRCA2*4075delGT mutation. Jewish high risk families of North African, Asian, and Balkan descent should be screened for the 981delAT, Tyr978X, A1708E BRCA1, and the R2336P BRCA2 mutations

  20. Reproductive and hormonal factors, and ovarian cancer risk for BRCA1 and BRCA2 mutation carriers:

    DEFF Research Database (Denmark)

    Antoniou, Antonis C; Rookus, Matti; Andrieu, Nadine;

    2009-01-01

    BACKGROUND: Several reproductive and hormonal factors are known to be associated with ovarian cancer risk in the general population, including parity and oral contraceptive (OC) use. However, their effect on ovarian cancer risk for BRCA1 and BRCA2 mutation carriers has only been investigated in a...... small number of studies. METHODS: We used data on 2,281 BRCA1 carriers and 1,038 BRCA2 carriers from the International BRCA1/2 Carrier Cohort Study to evaluate the effect of reproductive and hormonal factors on ovarian cancer risk for mutation carriers. Data were analyzed within a weighted Cox...... proportional hazards framework. RESULTS: There were no significant differences in the risk of ovarian cancer between parous and nulliparous carriers. For parous BRCA1 mutation carriers, the risk of ovarian cancer was reduced with each additional full-term pregnancy (P trend = 0.002). BRCA1 carriers who had...

  1. The pathology of familial breast cancer: The pre-BRCA1/BRCA2 era - historical perspectives

    International Nuclear Information System (INIS)

    A proportion of breast carcinomas develop as a result of a genetic predispostion to the disease. Prior to cloning of the BRCA1 and BRCA2 genes a limited number of studies were carried out to identify specific histopathological characteristics of hereditary breast cancer. These studies are the subject of this review. The main finding was the association of the (atypical) medullary type of breast cancer with a family history; the most important caveat being that medullary breast cancer is found more frequently in young patients. In view of the frequent bilateral occurrence of lobular cancer, this histologic type is also likely to be associated with a predisposing genetic defect. Future investigations will have to test this hypothesis. In addition to mutations in the BRCA1 and BRCA2 genes, there are as yet unidentified genetic defects predisposing to breast cancer development, and histopathology may well help in identifying these genes in the future

  2. Hypoxia and Human Genome Stability: Downregulation of BRCA2 Expression in Breast Cancer Cell Lines

    OpenAIRE

    Daniele Fanale; Viviana Bazan; Stefano Caruso; Marta Castiglia; Giuseppe Bronte; Christian Rolfo; Giuseppe Cicero; Antonio Russo

    2013-01-01

    Previously, it has been reported that hypoxia causes increased mutagenesis and alteration in DNA repair mechanisms. In 2005, an interesting study showed that hypoxia-induced decreases in BRCA1 expression and the consequent suppression of homologous recombination may lead to genetic instability. However, nothing is yet known about the involvement of BRCA2 in hypoxic conditions in breast cancer. Initially, a cell proliferation assay allowed us to hypothesize that hypoxia could negatively regula...

  3. Role of BRCA1 and BRCA2 mutations in pancreatic cancer

    OpenAIRE

    Greer, Julia B; David C. Whitcomb

    2006-01-01

    Germline mutations in the tumour suppressor genes breast cancer antigen gene (BRCA)1 and BRCA2 have been proven to portend a drastically increased lifetime risk of breast and ovarian cancers in the individuals who carry them. A number of studies have shown that the third most common cancer associated with these mutations is pancreatic cancer. BRCA1/2 mutations are characterised by “allelic” or “phenotypic” heterogeneity, in that they demonstrate differing cancer expressivity between and withi...

  4. Identification of a Danish breast/ovarian cancer family double heterozygote for BRCA1 and BRCA2 mutations

    DEFF Research Database (Denmark)

    Steffensen, Ane Y; Jønson, Lars; Ejlertsen, Bent; Gerdes, Anne-Marie; Nielsen, Finn C; Hansen, Thomas V O

    2010-01-01

    Mutations in the two breast cancer susceptibility genes BRCA1 and BRCA2 are associated with increased risk of breast and ovarian cancer. Patients with mutations in both genes are rarely reported and often involve Ashkenazi founder mutations. Here we report the first identification of a Danish...... breast and ovarian cancer family heterozygote for mutations in the BRCA1 and BRCA2 genes. The BRCA1 nucleotide 5215G > A/c.5096G > A mutation results in the missense mutation Arg1699Gln, while the BRCA2 nucleotide 859 + 4A > G/c.631 + 4A > G is novel. Exon trapping experiments and reverse transcriptase...... (RT)-PCR analysis revealed that the BRCA2 mutation results in skipping of exon 7, thereby introducing a frameshift and a premature stop codon. We therefore classify the mutation as disease causing. Since the BRCA1 Arg1699Gln mutation is also suggested to be disease-causing, we consider this family...

  5. Screening of 1331 Danish breast and/or ovarian cancer families identified 40 novel BRCA1 and BRCA2 mutations

    DEFF Research Database (Denmark)

    Hansen, Thomas V O; Jønson, Lars; Steffensen, Ane Y; Andersen, Mette K; Kjaergaard, Susanne; Gerdes, Anne-Marie; Ejlertsen, Bent; Nielsen, Finn C

    2011-01-01

    Germ-line mutations in the tumour suppressor genes BRCA1 and BRCA2 predispose to breast and ovarian cancer. Since 1999 we have performed mutational screening of breast and/or ovarian cancer patients in East Denmark. During this period we have identified 40 novel sequence variations in BRCA1 and...... BRCA2 in high risk breast and/or ovarian cancer families. The mutations were detected via pre-screening using dHPLC or high-resolution melting and direct sequencing. We identified 16 variants in BRCA1, including 9 deleterious frame-shift mutations, 2 intronic variants, 4 missense mutations, and 1......, the presumed significance of the missense mutations was predicted in silico using the align GVGD algorithm. In conclusion, the mutation screening identified 40 novel variants in the BRCA1 and BRCA2 genes and thereby extends the knowledge of the BRCA1/BRCA2 mutation spectrum. Nineteen of the mutations...

  6. Screening of 1331 Danish breast and/or ovarian cancer families identified 40 novel BRCA1 and BRCA2 mutations

    DEFF Research Database (Denmark)

    Hansen, Thomas V O; Jønson, Lars; Steffensen, Ane Y; Andersen, Mette K; Kjaergaard, Susanne; Gerdes, Anne-Marie; Ejlertsen, Bent; Nielsen, Finn C

    2011-01-01

    Germ-line mutations in the tumour suppressor genes BRCA1 and BRCA2 predispose to breast and ovarian cancer. Since 1999 we have performed mutational screening of breast and/or ovarian cancer patients in East Denmark. During this period we have identified 40 novel sequence variations in BRCA1 and...... BRCA2 in high risk breast and/or ovarian cancer families. The mutations were detected via pre-screening using dHPLC or high-resolution melting and direct sequencing. We identified 16 variants in BRCA1, including 9 deleterious frame-shift mutations, 2 intronic variants, 4 missense mutations, and 1......, the presumed significance of the missense mutations was predicted in silico using the align GVGD algorithm. In conclusion,the mutation screening identified 40 novel variants in the BRCA1 and BRCA2 genes and thereby extends the knowledge of the BRCA1/BRCA2 mutation spectrum. Nineteen of the mutations...

  7. Mitomycin-Induced Interstitial Pneumonitis in a Patient with BRCA2 Associated Metastatic Pancreatic Carcinoma

    Directory of Open Access Journals (Sweden)

    Muhammad Wasif Saif

    2010-05-01

    Full Text Available Dear Sir, Interstitial lung diseases are diffuse parenchymal lung diseases, and represent a heterogeneous group of disorders including lymphocytic interstitial pneumonitis, interstitial lung diseases of unknown etiology, including sarcoidosis, idiopathic pulmonary fibrosis, and pulmonary fibrosis associated with connective tissue diseases [1]. Most of the interstitial disorders have a restrictive pattern with reductions in total lung capacity, functional residual capacity, and residual volume [2]. The lung has significant susceptibility to injury from a variety of chemotherapeutic agents (Table 1. The clinician must be familiar with classic chemotherapeutic agents with well-described pulmonary toxicities and must also be vigilant about a host of new agents that may exert adverse effects on lung function [3]. BRCA2 mutations have been known to be associated with higher incidence of breast, ovarian and pancreatic adenocarcinoma [4, 5, 6]. Although present in only a minority of pancreatic cancers, mutations in the BRCA2 gene could provide a rational target for treatment with chemotherapeutic agents. Van der Heijden et al. have demonstrated that pancreatic cancer cells having defects in Fanconi anemia and BRCA2 pathway are remarkably sensitive to mitomycin-C both in culture and mice [7, 8]. Isacoff et al. reported good results with mitomycin-C plus fluorouracil regimen in first-line therapy of locally advanced pancreatic cancer, with two out of 50 patients achieving complete remission [9]. Another study using the same regimen in patients with metastatic pancreatic carcinoma also showed some activity including one complete remission [10].

  8. High penetrances of BRCA1 and BRCA2 mutations confirmed in a prospective series

    Directory of Open Access Journals (Sweden)

    Møller Pål

    2010-01-01

    Full Text Available Abstract Penetrances of BRCA1 and BRCA2 mutations have been derived from retrospective studies, implying the possibility of ascertainment biases to influence the results. We have followed women at risk for breast and/or ovarian cancer for two decades, and report the prospectively observed age-related annual incidence rates to contract breast or ovarian cancer for women with deleterious BRCA1 or BRCA2 mutations based on 4830 observation years. Patients were grouped according to mutation, age and having/not having had previous cancer. In women not having had previous cancer and aged 40-59 years, the annual incidence rate to contract breast or ovarian cancer in those having the most frequent BRCA1 founder mutations was 4.0%, for women in this age group and with less frequent BRCA1 mutations annual incidence rate was 5.9%, and for women with BRCA2 mutations 3.5%. The observed figures may be used for genetic counseling of healthy mutation carriers in the respective age groups. The results may indicate that less frequent BRCA1 mutations have higher penetrances than BRCA1 founder mutations.

  9. The role of BRCA1 and BRCA2 in prostate cancer

    Institute of Scientific and Technical Information of China (English)

    Elena Castro; Rosalind Eeles

    2012-01-01

    One of the strongest risk factors for prostate cancer is a family history of the disease.Germline mutations in the breast cancer predisposition gene 2 (BRCA2) are the genetic events known to date that confer the highest risk of prostate cancer (8.6-fold in men ≤ 65 years).Although the role of BRCA2 and BRCA1 in prostate tumorigenesis remains unrevealed,deleterious mutations in both genes have been associated with more aggressive disease and poor clinical outcomes.The increasing incidence of prostate cancer worldwide supports the need for new methods to predict outcome and identify patients with potentially lethal forms of the disease.As we present here,BRCA germline mutations,mainly in the BRCA2gene,are one of those predictive factors.We will also discuss the implications of these mutations in the management of prostate cancer and hypothesize on the potential for the development of strategies for sporadic cases with similar characteristics.

  10. Characterization of BRCA1 and BRCA2 splicing variants: a collaborative report by ENIGMA consortium members

    DEFF Research Database (Denmark)

    Thomassen, Mads; Blanco, Ana; Montagna, Marco;

    2012-01-01

    laboratories. Splicing analysis was performed by reverse transcriptase PCR or mini gene assay, and sequencing to identify aberrant transcripts. The findings were compared to bioinformatic predictions using four programs. The posterior probability of pathogenicity was estimated using multifactorial likelihood...... was initiated to evaluate and implement strategies to characterize the clinical significance of BRCA1 and BRCA2 variants. As an initial project of the ENIGMA Splicing Working Group, we report splicing and multifactorial likelihood analysis of 25 BRCA1 and BRCA2 variants from seven different...... analysis, including co-occurrence with a deleterious mutation, segregation and/or report of family history. Abnormal splicing patterns expected to lead to a non-functional protein were observed for 7 variants (BRCA1 c.441+2T>A, c.4184_4185+2del, c.4357+1G>A, c.4987-2A>G, c.5074G>C, BRCA2 c.316+5G>A, and c...

  11. Disseminated medulloblastoma in a child with germline BRCA2 6174delT mutation and without Fanconi anemia

    OpenAIRE

    Jingying eXu; Ashley Sloane Margol; Anju eShukla; Xiuhai eRen; Finlay, Jonathan L.; Krieger, Mark D.; Gilles, Floyd H.; Couch, Fergus J.; Meraj eAziz; Fung, Eric T; Shahab eAsgharzadeh; Barrett, Michael T.; Anat eErdreich-Epstein

    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 i...

  12. BRCA1 and BRCA2 sequence variations detected with next-generation sequencing in patients with premature ovarian insufficiency

    Science.gov (United States)

    Yılmaz, Nafiye Karakaş; Karagin, Peren Hatice; Terzi, Yunus Kasım; Kahyaoğlu, İnci; Yılmaz, Saynur; Erkaya, Salim; Şahin, Feride İffet

    2016-01-01

    Objective Although the association between BRCA1 and BRCA2 gene mutations and breast and ovarian cancer is known, there is insufficient data about premature ovarian insufficiency (POI). However, several studies have reported that there might be a relationship between POI and BRCA1 and BRCA2 gene mutation. Therefore, in the present study, we aimed to investigate the role of BRCA1 and BRCA2 gene mutations in the etiology of POI in a Turkish population. Material and Methods The cohort was classified into two groups: a study group, consisting of 56 individuals diagnosed with premature ovarian insufficiency (and who were younger than 40 years of age, had an antral follicle count 12 IU/I), and a control group, consisting of 45 fertile individuals. A total of 101 individuals were analyzed by next-generation sequencing to detect BRCA1 and BRCA2 gene mutations. Results We detected four new variations (p.T1246N and p.R1835Q in BRCA1 and p.I3312V and IVS-7T>A in BRCA2) that had not been reported before. Conclusion We did not find an association between the BRCA1 and BRCA2 gene mutations and premature ovarian insufficiency. However, larger, functional studies are needed to clarify the association.

  13. Characterization of BRCA1 and BRCA2 splicing variants: a collaborative report by ENIGMA consortium members.

    Science.gov (United States)

    Thomassen, Mads; Blanco, Ana; Montagna, Marco; Hansen, Thomas V O; Pedersen, Inge S; Gutiérrez-Enríquez, Sara; Menéndez, Mireia; Fachal, Laura; Santamariña, Marta; Steffensen, Ane Y; Jønson, Lars; Agata, Simona; Whiley, Phillip; Tognazzo, Silvia; Tornero, Eva; Jensen, Uffe B; Balmaña, Judith; Kruse, Torben A; Goldgar, David E; Lázaro, Conxi; Diez, Orland; Spurdle, Amanda B; Vega, Ana

    2012-04-01

    Mutations in BRCA1 and BRCA2 predispose carriers to early onset breast and ovarian cancer. A common problem in clinical genetic testing is interpretation of variants with unknown clinical significance. The Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) consortium was initiated to evaluate and implement strategies to characterize the clinical significance of BRCA1 and BRCA2 variants. As an initial project of the ENIGMA Splicing Working Group, we report splicing and multifactorial likelihood analysis of 25 BRCA1 and BRCA2 variants from seven different laboratories. Splicing analysis was performed by reverse transcriptase PCR or mini gene assay, and sequencing to identify aberrant transcripts. The findings were compared to bioinformatic predictions using four programs. The posterior probability of pathogenicity was estimated using multifactorial likelihood analysis, including co-occurrence with a deleterious mutation, segregation and/or report of family history. Abnormal splicing patterns expected to lead to a non-functional protein were observed for 7 variants (BRCA1 c.441+2T>A, c.4184_4185+2del, c.4357+1G>A, c.4987-2A>G, c.5074G>C, BRCA2 c.316+5G>A, and c.8754+3G>C). Combined interpretation of splicing and multifactorial analysis classified an initiation codon variant (BRCA2 c.3G>A) as likely pathogenic, uncertain clinical significance for 7 variants, and indicated low clinical significance or unlikely pathogenicity for another 10 variants. Bioinformatic tools predicted disruption of consensus donor or acceptor sites with high sensitivity, but cryptic site usage was predicted with low specificity, supporting the value of RNA-based assays. The findings also provide further evidence that clinical RNA-based assays should be extended from analysis of invariant dinucleotides to routinely include all variants located within the donor and acceptor consensus splicing sites. Importantly, this study demonstrates the added value of

  14. Embryonic stem cells deficient for Brca2 or Blm exhibit divergent genotoxic profiles that support opposing activities during homologous recombination

    International Nuclear Information System (INIS)

    The breast cancer susceptibility protein, Brca2 and the RecQ helicase, Blm (Bloom syndrome mutated) are tumor suppressors that maintain genome integrity, at least in part, through homologous recombination (HR). Brca2 facilitates HR by interacting with Rad51 in multiple regions, the BRC motifs encoded by exon 11 and a single domain encoded by exon 27; however, the exact importance of these regions is not fully understood. Blm also interacts with Rad51 and appears to suppress HR in most circumstances; however, its yeast homologue Sgs1 facilitates HR in response to some genotoxins. To better understand the biological importance of these two proteins, we performed a genotoxic screen on mouse embryonic stem (ES) cells impaired for either Brca2 or Blm to establish their genotoxic profiles (a cellular dose-response to a wide range of agents). This is the first side-by-side comparison of these two proteins in an identical genetic background. We compared cells deleted for Brca2 exon 27 to cells reduced for Blm expression and find that the Brca2- and Blm-impaired cells exhibit genotoxic profiles that reflect opposing activities during HR. Cells deleted for Brca2 exon 27 are hypersensitive to γ-radiation, streptonigrin, mitomycin C and camptothecin and mildly resistant to ICRF-193 which is similar to HR defective cells null for Rad54. By contrast, Blm-impaired cells are hypersensitive to ICRF-193, mildly resistant to camptothecin and mitomycin C and more strongly resistant to hydroxyurea. These divergent profiles support the notion that Brca2 and Blm perform opposing functions during HR in mouse ES cells

  15. BRCA1 and BRCA2 Gene Mutations Screening In Sporadic Breast Cancer Patients In Kazakhstan.

    Directory of Open Access Journals (Sweden)

    Ainur R. Akilzhanova

    2013-05-01

    Full Text Available Background: A large number of distinct mutations in the BRCA1 and BRCA2 genes have been reported worldwide, but little is known regarding the role of these inherited susceptibility genes in breast cancer risk among Kazakhstan women. Aim: To evaluate the role of BRCA1/2 mutations in Kazakhstan women presenting with sporadic breast cancer. Methods: We investigated the distribution and nature of polymorphisms in BRCA1 and BRCA2 entire coding regions in 156 Kazakhstan sporadic breast cancer cases and 112 age-matched controls using automatic direct sequencing. Results: We identified 22 distinct variants, including 16 missense mutations and 6 polymorphisms in BRCA1/2 genes. In BRCA1, 9 missense mutations and 3 synonymous polymorphisms were observed. In BRCA2, 7 missense mutations and 3 polymorphisms were detected. There was a higher prevalence of observed mutations in Caucasian breast cancer cases compared to Asian cases (p<0.05; higher frequencies of sequence variants were observed in Asian controls. No recurrent or founder mutations were observed in BRCA1/2 genes. There were no statistically significant differences in age at diagnosis, tumor histology, size of tumor, and lymph node involvement between women with breast cancer with or without the BRCA sequence alterations. Conclusions: Considering the majority of breast cancer cases are sporadic, the present study will be helpful in the evaluation of the need for the genetic screening of BRCA1/2 mutations and reliable genetic counseling for Kazakhstan sporadic breast cancer patients. Evaluation of common polymorphisms and mutations and breast cancer risk in families with genetic predisposition to breast cancer is ongoing in another current investigation. 

  16. Clinical Considerations of BRCA1- and BRCA2-Mutation Carriers: A Review

    Directory of Open Access Journals (Sweden)

    O. Bougie

    2011-01-01

    Full Text Available Individuals who carry an inherited mutation in the breast cancer 1 (BRCA1 and BRCA2 genes have a significant risk of developing breast and ovarian cancer over the course of their lifetime. As a result, there are important considerations for the clinician in the counseling, followup and management of mutation carriers. This review outlines salient aspects in the approach to patients at high risk of developing breast and ovarian cancer, including criteria for genetic testing, screening guidelines, surgical prophylaxis, and chemoprevention.

  17. Impact of heterozygous mutations in BRCA1 and BRCA2. Sensitivity to genotoxic drugs

    International Nuclear Information System (INIS)

    The carriers of heterozygous mutations in BRCA1 / 2 have a high risk of developing breast cancer. The loss of the normal allele with consequent loss of function is frequently observed in tumor level. Since these genes involved in the cellular response to genetic damage, loss of function can determine differences in sensitivity to genotoxic agents. In this study investigated whether heterozygous mutations in BRCA1 / 2 modify the sensitivity to genotoxic drugs using lymphoblastic cell lines developed from individuals who carry no mutation carriers and heterozygous for BRCA1 / 2. Materials and methods. Chemo sensitivity of the cell lines was compared lymphoblastoid GM13709 (mutation in exon 11 of BRCA1 2187delA), GM14622 (level 607stop mutation in exon 11 of BRCA2) and GM 14453 (normal BRCA1 / 2) from exposure to Adriamycin (0.2-2.5 mM) and Cisplatin (0.625- 80mM) through the test of cell viability based on MTT reduction. It determined the inhibitory concentration 50 (IC50) from curves regression dose-response obtained after 24 hours of drug exposure. It 5 independent experiments performed in triplicate. Results. The line GM14622 was significantly (P = 0.003) more sensitive to Adriamycin (IC50: 0.585 mM) than the Control GM14453 (IC50: 1.364 mM) online while GM13709 was similar to the control (IC50: 1.324 mM) response. Turn the line GM14622 was also significantly (P = 0.01) more sensitive cisplatin (IC50: 12.7 mM) than the line GM14453 (IC50: 28.6mm) and GM13709 had the same response as the (IC50: 28.6 mM) control. Discussion and Conclusions. Our results suggest that mutations deleterious heterozygous BRCA2 may confer increased sensitivity to drugs genotoxic, which may have implications in the management of patients carrying or BRCA2 mutations in women with sporadic breast cancer exhibit low expression of BRCA2

  18. Telomere length shows no association with BRCA1 and BRCA2 mutation status

    DEFF Research Database (Denmark)

    Killick, Emma; Tymrakiewicz, Malgorzata; Cieza-Borrella, Clara;

    2014-01-01

    time of enrollment and blood donation, 21 of whom have developed prostate cancer whilst on study. The second group consisted of 283 female BRCA1/2 mutation carriers and controls (mean age 48 years), half of whom had been diagnosed with breast cancer prior to enrollment. TL was quantified by qPCR from...... DNA extracted from peripheral blood lymphocytes. Weighted and unweighted Cox regressions and linear regression analyses were used to assess whether TL was associated with BRCA1/2 mutation status or cancer risk. We found no evidence for association between developing cancer or being a BRCA1 or BRCA2...

  19. Presymptomatic breast cancer in Egypt: role of BRCA1 and BRCA2 tumor suppressor genes mutations detection

    Directory of Open Access Journals (Sweden)

    Hashishe Mervat M

    2010-06-01

    Full Text Available Abstract Background Breast cancer is one of the most common diseases affecting women. Inherited susceptibility genes, BRCA1 and BRCA2, are considered in breast, ovarian and other common cancers etiology. BRCA1 and BRCA2 genes have been identified that confer a high degree of breast cancer risk. Objective Our study was performed to identify germline mutations in some exons of BRCA1 and BRCA2 genes for the early detection of presymptomatic breast cancer in females. Methods This study was applied on Egyptian healthy females who first degree relatives to those, with or without a family history, infected with breast cancer. Sixty breast cancer patients, derived from 60 families, were selected for molecular genetic testing of BRCA1 and BRCA2 genes. The study also included 120 healthy first degree female relatives of the patients, either sisters and/or daughters, for early detection of presymptomatic breast cancer mutation carriers. Genomic DNA was extracted from peripheral blood lymphocytes of all the studied subjects. Universal primers were used to amplify four regions of the BRCA1 gene (exons 2,8,13 and 22 and one region (exon 9 of BRCA2 gene using specific PCR. The polymerase chain reaction was carried out. Single strand conformation polymorphism assay and heteroduplex analysis were used to screen for mutations in the studied exons. In addition, DNA sequencing of the normal and mutated exons were performed. Results Mutations in both BRCA1 and BRCA2 genes were detected in 86.7% of the families. Current study indicates that 60% of these families were attributable to BRCA1 mutations, while 26.7% of them were attributable to BRCA2 mutations. Results showed that four mutations were detected in the BRCA1 gene, while one mutation was detected in the BRCA2 gene. Asymptomatic relatives, 80(67% out of total 120, were mutation carriers. Conclusions BRCA1 and BRCA2 genes mutations are responsible for a significant proportion of breast cancer. BRCA mutations

  20. Killing the umpire: cooperative defects in mitotic checkpoint and BRCA2 genes on the road to transformation

    International Nuclear Information System (INIS)

    Recent findings from mouse models of BRCA2 genetic lesions have provided intriguing insights and important questions concerning modes of tumor development in familial breast and ovarian cancers. Fibroblasts from mice homozygous for the BRCA2Tr allele grow poorly and display an array of chromosomal abnormalities that are consistent with a role for BRCA2 in DNA repair. This growth defect can be overcome and cellular transformation promoted by the expression of defective, dominant negative alleles of p53 and of the mitotic checkpoint gene Bub1, both of which are known to induce chromosome instability. These findings are mirrored in the genetic lesions sustained in tumors found in the rare BRCA2Tr/Trmice that survive to adulthood, which include defects in p53 as well as the mitotic checkpoint proteins Bub1 and Mad3L. Together, these data hint that tumors in these mice evolve from an unusually intense selective pressure to remove DNA damage checkpoints, which in turn might be facilitated by chromosomal abolition of mitotic checkpoints and the consequent increase in shuffling of genetic information. How these genetic lesions co-operate to yield transformed cells and how these data relate to BRCA1 and BRCA2 defects in the human population are important questions raised by this work

  1. Regulation of BRCA1, BRCA2 and BARD1 intracellular trafficking.

    Science.gov (United States)

    Henderson, Beric R

    2005-09-01

    The subcellular location and function of many proteins are regulated by nuclear-cytoplasmic shuttling. BRCA1 and BARD1 provide an interesting model system for understanding the influence of protein dimerization on nuclear transport and localization. These proteins function predominantly in the nucleus to regulate cell cycle progression, DNA repair/recombination and gene transcription, and their export to the cytoplasm has been linked to apoptosis. Germ-line mutations in the BRCA1/BRCA2 and BARD1 genes predispose to risk of breast/ovarian cancer, and certain mutations impair protein function and nuclear accumulation. BRCA1 and BARD1 shuttle between the nucleus and cytoplasm; however heterodimerization masks the nuclear export signals located within each protein, causing nuclear retention of the BRCA1-BARD1 complex and potentially influencing its role in DNA repair, cell survival and regulation of centrosome duplication. This review discusses BRCA1, BRCA2 and BARD1 subcellular localization with emphasis on regulation of transport by protein dimerization and its functional implications. PMID:16108063

  2. Contribution of BRCA1 and BRCA2 Germline Mutations to Early Algerian Breast Cancer.

    Science.gov (United States)

    Henouda, Sarra; Bensalem, Assia; Reggad, Rym; Serrar, Nedda; Rouabah, Leila; Pujol, Pascal

    2016-01-01

    Breast cancer is the most common female malignancy and the leading cancer mortality cause among Algerian women. Germline mutations in the BRCA1 and BRCA2 genes in patients with early-onset breast cancer have not been clearly identified within the Algerian population. It is necessary to study the BRCA1/2 genes involvement in the Algerian breast cancer occurrence. We performed this study to define germline mutations in BRCA1/2 and their implication in breast cancer among young women from eastern Algeria diagnosed or treated with primary invasive breast cancer at the age of 40 or less who were referred to Anti-Cancer Center of Setif, Algeria. Case series were unselected for family history. Eight distinct pathogenic mutations were identified in eight unrelated families. Three deleterious mutations and one large genomic rearrangement involving deletion of exon 2 were found in BRCA1 gene. In addition, four mutations within the BRCA2 gene and one large genomic rearrangement were identified. Novel mutation was found among Algerian population. Moreover, five variants of uncertain clinical significance and favor polymorphisms were identified. Our data suggest that BRCA1/2 mutations are responsible for a significant proportion of breast cancer in Algerian young women. PMID:26997744

  3. Telomere length shows no association with BRCA1 and BRCA2 mutation status.

    Directory of Open Access Journals (Sweden)

    Emma Killick

    Full Text Available This study aimed to determine whether telomere length (TL is a marker of cancer risk or genetic status amongst two cohorts of BRCA1 and BRCA2 mutation carriers and controls. The first group was a prospective set of 665 male BRCA1/2 mutation carriers and controls (mean age 53 years, all healthy at time of enrollment and blood donation, 21 of whom have developed prostate cancer whilst on study. The second group consisted of 283 female BRCA1/2 mutation carriers and controls (mean age 48 years, half of whom had been diagnosed with breast cancer prior to enrollment. TL was quantified by qPCR from DNA extracted from peripheral blood lymphocytes. Weighted and unweighted Cox regressions and linear regression analyses were used to assess whether TL was associated with BRCA1/2 mutation status or cancer risk. We found no evidence for association between developing cancer or being a BRCA1 or BRCA2 mutation carrier and telomere length. It is the first study investigating TL in a cohort of genetically predisposed males and although TL and BRCA status was previously studied in females our results don't support the previous finding of association between hereditary breast cancer and shorter TL.

  4. Elevated expression of Ki-67 identifies aggressive prostate cancers but does not distinguish BRCA1 or BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Mitra, A V; Jameson, C; Barbachano, Y;

    2010-01-01

    Prostate cancers in men with germline BRCA1 and BRCA2 mutations are more aggressive than morphologically similar cancers in men without these mutations. This study was performed to test the hypothesis that enhanced expression of Ki-67, as a surrogate of cell proliferation, is a characteristic...... and benign tissues (p0.5). Similar results were obtained when the data were analysed using a threshold set at 3.5 and 7.1%. This study shows that elevated expression of Ki-67 is associated both with aggressive prostate cancers and with high Gleason score irrespective of whether their occurrence is...... against a background of BRCA1 or BRCA2 mutations or as sporadic disease. The data suggest that, since elevated Ki-67 does not distinguish prostate cancers occurring in BRCA1 or BRCA2 mutation carriers from sporadic prostatic malignancies, the effects of these genetic mutations are probably independent...

  5. Identification of a BRCA2-specific modifier locus at 6p24 related to breast cancer risk

    DEFF Research Database (Denmark)

    Gaudet, Mia M; Kuchenbaecker, Karoline B; Vijai, Joseph;

    2013-01-01

    Common genetic variants contribute to the observed variation in breast cancer risk for BRCA2 mutation carriers; those known to date have all been found through population-based genome-wide association studies (GWAS). To comprehensively identify breast cancer risk modifying loci for BRCA2 mutation...... carriers, we conducted a deep replication of an ongoing GWAS discovery study. Using the ranked P-values of the breast cancer associations with the imputed genotype of 1.4 M SNPs, 19,029 SNPs were selected and designed for inclusion on a custom Illumina array that included a total of 211,155 SNPs as part of...... a multi-consortial project. DNA samples from 3,881 breast cancer affected and 4,330 unaffected BRCA2 mutation carriers from 47 studies belonging to the Consortium of Investigators of Modifiers of BRCA1/2 were genotyped and available for analysis. We replicated previously reported breast cancer...

  6. Exome mutation burden predicts clinical outcome in ovarian cancer carrying mutated BRCA1 and BRCA2 genes

    DEFF Research Database (Denmark)

    Birkbak, Nicolai Juul; Kochupurakkal, Bose; Gonzalez-Izarzugaza, Jose Maria;

    2013-01-01

    Reliable biomarkers predicting resistance or sensitivity to anti-cancer therapy are critical for oncologists to select proper therapeutic drugs in individual cancer patients. Ovarian and breast cancer patients carrying germline mutations in BRCA1 or BRCA2 genes are often sensitive to DNA damaging......-type BRCA1 and BRCA2 genes. These results suggest that in cancers with DNA repair deficiency caused by functional BRCA loss, higher versus lower Nmut may reflect the status of deficiency or rescue by alternative mechanism(s) for DNA repair, with lower Nmut predicting for resistance to DNA-damaging drugs in...... drugs and relative to non-mutation carriers present a favorable clinical outcome following therapy. Genome sequencing studies have shown a high number of mutations in the tumor genome in patients carrying BRCA1 or BRCA2 mutations (mBRCA). The present study used exome-sequencing and SNP 6 array data of...

  7. Two different BRCA2 mutations found in a multigenerational family with a history of breast, prostate, and lung cancers

    Directory of Open Access Journals (Sweden)

    Caporale DA

    2014-06-01

    Full Text Available Diane A Caporale, Erica E SwensonDepartment of Biology, University of Wisconsin – Stevens Point, Stevens Point, WI, USAAbstract: Breast and lung cancer are two of the most common malignancies in the United States, causing approximately 40,000 and 160,000 deaths each year, respectively. Over 80% of hereditary breast cancer cases are due to mutations in two breast cancer predisposition genes, BRCA1 and BRCA2. These are tumor-suppressor genes associated with DNA repair. Since the discovery of these two genes in the mid-1990s, several other breast cancer predisposition genes have been identified, such as the CHEK2 gene encoding a regulator of BRCA1. Recently, studies have begun investigating the roles of BRCA1 and BRCA2 gene expression in lung cancer. We conducted a family-based case study that included a bloodline of Italian heritage with several cases of breast cancer and associated cancers (prostate and stomach through multiple generations and on a nonblood relative of Scottish/Irish descent who was consecutively diagnosed with breast and lung cancer. Cancer history and environmental risk factors were recorded for each family member. To investigate possible genetic risks, we screened for mutations in specific hypervariable regions of the BRCA1, BRCA2, and CHEK2 genes. DNA was extracted and isolated from the individuals' hair follicles and cheek cells. Polymerase chain reaction (PCR, allele-specific PCR, and DNA sequencing were performed to identify and verify the presence or absence of mutations in these regions. Genotypes of several family members were determined and carriers of mutations were identified. Here we report for the first time the occurrence of two different BRCA2 frameshift mutations within the same family. Specifically, three Italian family members were found to be carriers of the BRCA2-c.2808_2811delACAA (3036delACAA mutation, a 4-nucleotide deletion in exon 11, which is a truncated mutation that causes deleterious function of

  8. Sequence Variants of BRCA1 and BRCA2 Genes in Four Iranian Families with Breast and Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    F Keshavarzi

    2011-06-01

    Full Text Available "nBackground: BRCA1 and BRCA2 genes have been recognized to be responsible for 20-30% of hereditary breast can­cers and approximately 50% of familial breast and ovarian cancers. Therefore, the demand for BRCA1 and BRCA2 muta­tion screening is rapidly increasing as their identification will affect medical management of people at increased risk. Because of high costs involved in analysis of BRCA1 and 2 genes, contribution of different mutation types in BRCA1 and 2 and not knowing who should be tested has hampered wide spread use of molecular testing of high -risk fami­lies. There is a need to identify the genes and types of mutations involved in breast or ovarian cancers at different age of onsets and polymorphism and polymorphic variations in our population."nMethods: Twenty-seven patients with either early onset breast cancer (at age≤ 35 years or a personal and/or family his­tory of breast or ovarian cancer and 50 control subjects participated in this study. After collecting blood samples and extract­ing DNA, BRCA1 and BRCA2 genes were fully sequenced."nResults: Thirteen missense substitutions in BRCA1 and BRCA2 (9 and 4, respectively were revealed. Two nucleotide substitu­tions were novel (Gly1140Ser in BRCA1 and Glu1391Gly in BRCA2. The Glu1038Pro and Gly1140Ser were found in large series of breast and ovarian cancer and matched controls."nConclusion: Some nucleotide substitutions were seen only in single families and other in several. In other cases, muta­tions were seen in both BRCA1 and BRCA2 genes. Clinical significance of these mutations was evaluated comparing with normal controls.  

  9. A role of BRCA1 and BRCA2 germline mutations in breast cancer susceptibility within Sardinian population

    International Nuclear Information System (INIS)

    In recent years, numerous studies have assessed the prevalence of germline mutations in BRCA1 and BRCA2 genes in various cohorts. We here extensively investigated the prevalence and geographical distribution of BRCA1-2 mutations in the entire genetically-homogeneous Sardinian population. The occurrence of phenotypic characteristics which may be predictive for the presence of BRCA1-2 germline mutations was also evaluated. Three hundred and forty-eight breast cancer patients presenting a familial recurrence of invasive breast or ovarian carcinoma with at least two affected family members were screened for BRCA1-2 mutations by DHPLC analysis and DNA sequencing. Association of BRCA1 and BRCA2 mutational status with clinical and pathological parameters was evaluated by Pearson's Chi-Squared test. Overall, 8 BRCA1 and 5 BRCA2 deleterious mutations were detected in 35/348 (10%) families; majority (23/35;66%) of mutations was found in BRCA2 gene. The geographical distribution of BRCA1-2 mutations was related to three specific large areas of Sardinia, reflecting its ancient history: a) the Northern area, linguistically different from the rest of the island (where a BRCA2 c.8764-8765delAG mutation with founder effect was predominant); b) the Middle area, land of the ancient Sardinian population (where BRCA2 mutations are still more common than BRCA1 mutations); and c) the South-Western area, with many Phoenician and Carthaginian locations (where BRCA1 mutations are prevalent). We also found that phenotypic features such as high tumor grading and lack of expression of estrogen/progesterone receptors together with age at diagnosis and presence of ovarian cancer in the family may be predictive for the presence of BRCA1-2 germline mutations

  10. The BRCA1/BRCA2/Rad51 complex is a prognostic and predictive factor in early breast cancer

    International Nuclear Information System (INIS)

    Background and purpose: The breast cancer susceptibility genes BRCA1 and BRCA2 interact with Rad51, one of the central components in the homologous recombination repair pathway. This study evaluates the prognostic and predictive role of BRCA1, BRCA2 and Rad51, individually and as a complex, in breast cancer. Materials and methods: Expression of BRCA1, BRCA2 and Rad51 was investigated using immunohistochemistry in tumours from 224 women with early breast cancer, who were randomised to receive postoperative radiotherapy or adjuvant chemotherapy (CMF). Results: Fifty-three percent (112/212) of the tumours had reduced expression of the BRCA1/BRCA2/Rad51 complex. Low expression correlated to high histologic grade (p = 0.05). Patients with low expression of the complex developed significantly more local recurrences as compared to patients with high expression (RR = 3.20, 95% CI 1.48-6.88, p = 0.003). Expression of the BRCA1/BRCA2/Rad51 complex was an independent prognostic factor in multivariate analysis (p = 0.03). Patients with low expression of the complex responded well to radiotherapy (RR = 0.31, 95% CI 0.14-0.70, p = 0.005), whereas patients with high expression had few local recurrences and no additional benefit from radiotherapy (RR = 1.08, 95% CI 0.40-2.90, p = 0.88). Conclusions: Low expression of the BRCA1/BRCA2/Rad51 complex is a marker of poor prognosis, but predicts good response to radiotherapy in patients with early breast cancer

  11. Inducibility of nuclear Rad51 foci after DNA damage distinguishes all Fanconi anemia complementation groups from D1/BRCA2

    International Nuclear Information System (INIS)

    Fanconi anemia (FA) is a cancer susceptibility disorder characterized by chromosomal instability and hypersensitivity to DNA cross-linking agents. So far 11 complementation groups have been identified, from which only FA-D1/BRCA2 and FA-J are defective downstream of the central FANCD2 protein as cells from these groups are capable of monoubiquitinating FANCD2. In this study we show that cells derived from patients from the new complementation groups, FA-I, FA-J and FA-L are all proficient in DNA damage induced Rad51 foci formation, making the cells from FA-D1/BRCA2 patients that are defective in this process the sole exception. Although FA-B patient HSC230 was previously reported to also have biallelic BRCA2 mutations, we found normal Rad51 foci formation in cells from this patient, consistent with the recent identification of an X-linked gene being mutated in four unrelated FA-B patients. Thus, our data show that none of the FA proteins, except BRCA2, are required to sequester Rad51 into nuclear foci. Since cells from the FA-D1 and FA-J patient groups are both able to monoubiquitinate FANCD2, the 'Rad51 foci phenotype' provides a convenient assay to distinguish between these two groups. Our results suggest that FANCJ and FANCD1/BRCA2 are part of the integrated FANC/BRCA DNA damage response pathway or, alternatively, that they represent sub-pathways in which only FANCD1/BRCA2 is directly connected to the process of homologous recombination

  12. De novo recurrent germline mutation of the BRCA2 gene in a patient with early onset breast cancer

    OpenAIRE

    van der Luijt, R. B.; van Zon, P. H A; Jansen, R.; van der Sijs-Bos, C. J M; Warlam-Rodenhuis, C.; Ausems, M.

    2001-01-01

    Germline mutations in either of the two major breast cancer predisposition genes, BRCA1 and BRCA2, account for a significant proportion of hereditary breast/ovarian cancer. Identification of breast cancer patients carrying mutations of these genes is primarily based on a positive family history of breast/ovarian cancer or early onset of the disease or both. In the course of mutation screening of the BRCA1 and BRCA2 genes in a hospital based series of patients with risk factors for hereditary ...

  13. Identification of a BRCA2-Specific Modifier Locus at 6p24 Related to Breast Cancer Risk

    Science.gov (United States)

    Vijai, Joseph; Klein, Robert J.; Kirchhoff, Tomas; McGuffog, Lesley; Barrowdale, Daniel; Dunning, Alison M.; Lee, Andrew; Dennis, Joe; Healey, Sue; Dicks, Ed; Soucy, Penny; Sinilnikova, Olga M.; Pankratz, Vernon S.; Wang, Xianshu; Eldridge, Ronald C.; Tessier, Daniel C.; Vincent, Daniel; Bacot, Francois; Hogervorst, Frans B. L.; Peock, Susan; Stoppa-Lyonnet, Dominique; Peterlongo, Paolo; Schmutzler, Rita K.; Nathanson, Katherine L.; Piedmonte, Marion; Singer, Christian F.; Thomassen, Mads; Hansen, Thomas v. O.; Neuhausen, Susan L.; Blanco, Ignacio; Greene, Mark H.; Garber, Judith; Weitzel, Jeffrey N.; Andrulis, Irene L.; Goldgar, David E.; D'Andrea, Emma; Caldes, Trinidad; Nevanlinna, Heli; Osorio, Ana; van Rensburg, Elizabeth J.; Arason, Adalgeir; Rennert, Gad; van den Ouweland, Ans M. W.; van der Hout, Annemarie H.; Kets, Carolien M.; Aalfs, Cora M.; Wijnen, Juul T.; Ausems, Margreet G. E. M.; Frost, Debra; Ellis, Steve; Fineberg, Elena; Platte, Radka; Evans, D. Gareth; Jacobs, Chris; Adlard, Julian; Tischkowitz, Marc; Porteous, Mary E.; Damiola, Francesca; Golmard, Lisa; Barjhoux, Laure; Longy, Michel; Belotti, Muriel; Ferrer, Sandra Fert; Mazoyer, Sylvie; Spurdle, Amanda B.; Manoukian, Siranoush; Barile, Monica; Genuardi, Maurizio; Arnold, Norbert; Meindl, Alfons; Sutter, Christian; Wappenschmidt, Barbara; Domchek, Susan M.; Pfeiler, Georg; Friedman, Eitan; Jensen, Uffe Birk; Robson, Mark; Shah, Sohela; Lazaro, Conxi; Mai, Phuong L.; Benitez, Javier; Southey, Melissa C.; Schmidt, Marjanka K.; Fasching, Peter A.; Peto, Julian; Humphreys, Manjeet K.; Wang, Qin; Michailidou, Kyriaki; Sawyer, Elinor J.; Burwinkel, Barbara; Guénel, Pascal; Bojesen, Stig E.; Milne, Roger L.; Brenner, Hermann; Lochmann, Magdalena; Aittomäki, Kristiina; Dörk, Thilo; Margolin, Sara; Mannermaa, Arto; Lambrechts, Diether; Chang-Claude, Jenny; Radice, Paolo; Giles, Graham G.; Haiman, Christopher A.; Winqvist, Robert; Devillee, Peter; García-Closas, Montserrat; Schoof, Nils; Hooning, Maartje J.; Cox, Angela; Pharoah, Paul D. P.; Jakubowska, Anna; Orr, Nick; González-Neira, Anna; Pita, Guillermo; Alonso, M. Rosario; Hall, Per; Couch, Fergus J.; Simard, Jacques; Altshuler, David; Easton, Douglas F.; Chenevix-Trench, Georgia; Antoniou, Antonis C.; Offit, Kenneth

    2013-01-01

    Common genetic variants contribute to the observed variation in breast cancer risk for BRCA2 mutation carriers; those known to date have all been found through population-based genome-wide association studies (GWAS). To comprehensively identify breast cancer risk modifying loci for BRCA2 mutation carriers, we conducted a deep replication of an ongoing GWAS discovery study. Using the ranked P-values of the breast cancer associations with the imputed genotype of 1.4 M SNPs, 19,029 SNPs were selected and designed for inclusion on a custom Illumina array that included a total of 211,155 SNPs as part of a multi-consortial project. DNA samples from 3,881 breast cancer affected and 4,330 unaffected BRCA2 mutation carriers from 47 studies belonging to the Consortium of Investigators of Modifiers of BRCA1/2 were genotyped and available for analysis. We replicated previously reported breast cancer susceptibility alleles in these BRCA2 mutation carriers and for several regions (including FGFR2, MAP3K1, CDKN2A/B, and PTHLH) identified SNPs that have stronger evidence of association than those previously published. We also identified a novel susceptibility allele at 6p24 that was inversely associated with risk in BRCA2 mutation carriers (rs9348512; per allele HR = 0.85, 95% CI 0.80–0.90, P = 3.9×10−8). This SNP was not associated with breast cancer risk either in the general population or in BRCA1 mutation carriers. The locus lies within a region containing TFAP2A, which encodes a transcriptional activation protein that interacts with several tumor suppressor genes. This report identifies the first breast cancer risk locus specific to a BRCA2 mutation background. This comprehensive update of novel and previously reported breast cancer susceptibility loci contributes to the establishment of a panel of SNPs that modify breast cancer risk in BRCA2 mutation carriers. This panel may have clinical utility for women with BRCA2 mutations weighing options for medical

  14. Identification of a BRCA2-specific modifier locus at 6p24 related to breast cancer risk.

    Directory of Open Access Journals (Sweden)

    Mia M Gaudet

    Full Text Available Common genetic variants contribute to the observed variation in breast cancer risk for BRCA2 mutation carriers; those known to date have all been found through population-based genome-wide association studies (GWAS. To comprehensively identify breast cancer risk modifying loci for BRCA2 mutation carriers, we conducted a deep replication of an ongoing GWAS discovery study. Using the ranked P-values of the breast cancer associations with the imputed genotype of 1.4 M SNPs, 19,029 SNPs were selected and designed for inclusion on a custom Illumina array that included a total of 211,155 SNPs as part of a multi-consortial project. DNA samples from 3,881 breast cancer affected and 4,330 unaffected BRCA2 mutation carriers from 47 studies belonging to the Consortium of Investigators of Modifiers of BRCA1/2 were genotyped and available for analysis. We replicated previously reported breast cancer susceptibility alleles in these BRCA2 mutation carriers and for several regions (including FGFR2, MAP3K1, CDKN2A/B, and PTHLH identified SNPs that have stronger evidence of association than those previously published. We also identified a novel susceptibility allele at 6p24 that was inversely associated with risk in BRCA2 mutation carriers (rs9348512; per allele HR = 0.85, 95% CI 0.80-0.90, P = 3.9 × 10(-8. This SNP was not associated with breast cancer risk either in the general population or in BRCA1 mutation carriers. The locus lies within a region containing TFAP2A, which encodes a transcriptional activation protein that interacts with several tumor suppressor genes. This report identifies the first breast cancer risk locus specific to a BRCA2 mutation background. This comprehensive update of novel and previously reported breast cancer susceptibility loci contributes to the establishment of a panel of SNPs that modify breast cancer risk in BRCA2 mutation carriers. This panel may have clinical utility for women with BRCA2 mutations weighing options for

  15. Fine-Scale Mapping at 9p22.2 Identifies Candidate Causal Variants That Modify Ovarian Cancer Risk in BRCA1 and BRCA2 Mutation Carriers

    DEFF Research Database (Denmark)

    Vigorito, Elena; Kuchenbaecker, Karoline B; Beesley, Jonathan;

    2016-01-01

    Population-based genome wide association studies have identified a locus at 9p22.2 associated with ovarian cancer risk, which also modifies ovarian cancer risk in BRCA1 and BRCA2 mutation carriers. We conducted fine-scale mapping at 9p22.2 to identify potential causal variants in BRCA1 and BRCA2 ...

  16. An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers

    NARCIS (Netherlands)

    S. Blein (Sophie); C. Bardel (Claire); V. Danjean (Vincent); L. McGuffog (Lesley); S. Healey (Sue); D. Barrowdale (Daniel); A. Lee (Andrew); J. Dennis (Joe); K.B. Kuchenbaecker (Karoline); P. Soucy (Penny); M.B. Terry (Mary Beth); W. Chung (Wendy); D. Goldgar (David); S.S. Buys (Saundra); R. Janavicius (Ramunas); L. Tihomirova (Laima); N. Tung (Nadine); C.M. Dorfling (Cecilia); E.J. van Rensburg (Elizabeth); S.L. Neuhausen (Susan); Y.C. Ding (Yuan); A-M. Gerdes (Anne-Marie); B. Ejlertsen (Bent); F. Nielsen (Finn); T.V.O. Hansen (Thomas); A. Osorio (Ana); J. Benítez (Javier); R.A. Conejero (Raquel Andrés); E. Segota (Ena); J.N. Weitzel (Jeffrey); M. Thelander (Margo); P. Peterlongo (Paolo); P. Radice (Paolo); V. Pensotti (Valeria); R. Dolcetti (Riccardo); B. Bonnani (Bernardo); B. Peissel (Bernard); D. Zaffaroni (D.); G. Scuvera (Giulietta); S. Manoukian (Siranoush); L. Varesco (Liliana); G.L. Capone (Gabriele L.); L. Papi (Laura); L. Ottini (Laura); D. Yannoukakos (Drakoulis); I. Konstantopoulou (I.); J. Garber (Judy); U. Hamann (Ute); A. Donaldson (Alan); A. Brady (A.); C. Brewer (Carole); C. Foo (Claire); D.G. Evans (Gareth); D. Frost (Debra); D. Eccles (Diana); F. Douglas (Fiona); J. Cook (Jackie); L. Adlard; J. Barwell (Julian); L.J. Walker (Lisa); L. Izatt (Louise); L. Side (Lucy); M.J. Kennedy (John); M. Tischkowitz (Marc); M.T. Rogers (Mark); M.E. Porteous (Mary); P.J. Morrison (Patrick); R. Platte (Radka); R. Eeles (Ros); R. Davidson (Rosemarie); S. Hodgson (Shirley); T.J. Cole (Trevor); A.K. Godwin (Andrew); C. Isaacs (Claudine); K.B.M. Claes (Kathleen B.M.); K. De Leeneer (Kim); A. Meindl (Alfons); P.A. Gehrig (Paola A.); B. Wapenschmidt (Barbara); C. Sutter (Christian); C. Engel (Christoph); D. Niederacher (Dieter); D. Steinemann (Doris); H. Plendl (Hansjoerg); K. Kast (Karin); K. Rhiem (Kerstin); N. Ditsch (Nina); N. Arnold (Norbert); R. Varon-Mateeva (Raymonda); R.K. Schmutzler (Rita); S. Preisler-Adams (Sabine); N.B. Markov (Nadja Bogdanova); S. Wang-Gohrke (Shan); A. de Pauw (Antoine); C. Lefol (Cédrick); C. Lasset (Christine); D. Leroux (Dominique); E. Rouleau (Etienne); F. Damiola (Francesca); H. Dreyfus (Hélène); L. Barjhoux (Laure); L. Golmard (Lisa); N. Uhrhammer (Nancy); V. Bonadona (Valérie); V. Sornin (Valérie); Y.-J. Bignon (Yves-Jean); J. Carter (Jonathan); L. van Le (Linda); M. Piedmonte (Marion); P. DiSilvestro (Paul); M. de La Hoya (Miguel); T. Caldes (Trinidad); H. Nevanlinna (Heli); K. Aittomäki (Kristiina); A. Jager (Agnes); A.M.W. van den Ouweland (Ans); C.M. Kets; C.M. Aalfs (Cora); F.E. van Leeuwen (F.); F.B.L. Hogervorst (Frans); E.J. Meijers-Heijboer (Hanne); J.C. Oosterwijk (Jan); K.E. van Roozendaal (Kees); M.A. Rookus (M.); P. Devilee (Peter); R.B. van der Luijt (Rob); E. Olah; O. Díez (Orland); A. Teulé (A.); C. Lazaro (Conxi); I. Blanco (Ignacio); J. Del Valle (Jesús); A. Jakubowska (Anna); G. Sukiennicki (Grzegorz); J. Gronwald (Jacek); J. Lubinski (Jan); K. Durda (Katarzyna); K. Jaworska-Bieniek (Katarzyna); B.A. Agnarsson (Bjarni); C. Maugard; A. Amadori (Alberto); M. Montagna (Marco); P.J. Teixeira; A.B. Spurdle (Amanda); W.D. Foulkes (William); C. Olswold (Curtis); N.M. Lindor (Noralane); V.S. Pankratz (Shane); C. Szabo (Csilla); A. Lincoln (Anne); L. Jacobs (Lauren); M. Corines (Marina); M. Robson (Mark); J. Vijai (Joseph); A. Berger (Andreas); A. Fink-Retter (Anneliese); C.F. Singer (Christian); C. Rappaport (Christine); D.G. Kaulich (Daphne Gschwantler); G. Pfeiler (Georg); M.-K. Tea; M.H. Greene (Mark); P.L. Mai (Phuong); G. Rennert (Gad); E.N. Imyanitov (Evgeny); A.M. Mulligan (Anna Marie); G. Glendon (Gord); I.L. Andrulis (Irene); S. Tchatchou (Sandrine); A.E. Toland (Amanda); I.S. Pedersen (Inge Sokilde); M. Thomassen (Mads); T.A. Kruse (Torben); U.B. Jensen; M.A. Caligo (Maria); E. Friedman (Eitan); J. Zidan (Jamal); Y. Laitman (Yael); A. Lindblom (Annika); B. Melin (Beatrice); B. Arver (Brita Wasteson); N. Loman (Niklas); R. Rosenquist (R.); O.I. Olopade (Olofunmilayo); R. Nussbaum (Robert); S.J. Ramus (Susan); K.L. Nathanson (Katherine); S.M. Domchek (Susan); R. Rebbeck (Timothy); B.K. Arun (Banu); G. Mitchell (Gillian); B. Karlan; K.J. Lester (Kathryn); S. Orsulic (Sandra); D. Stoppa-Lyonnet (Dominique); G. Thomas (Gilles); J. Simard (Jacques); F.J. Couch (Fergus); K. Offit (Kenneth); D.F. Easton (Douglas); G. Chenevix-Trench (Georgia); A.C. Antoniou (Antonis C.); S. Mazoyer (Sylvie); C. Phelan (Catherine); O. Sinilnikova (Olga); D.G. Cox (David)

    2015-01-01

    textabstractIntroduction: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of whi

  17. An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers

    NARCIS (Netherlands)

    Blein, Sophie; Bardel, Claire; Danjean, Vincent; McGuffog, Lesley; Healey, Sue; Barrowdale, Daniel; Lee, Andrew; Dennis, Joe; Kuchenbaecker, Karoline B.; Soucy, Penny; Terry, Mary Beth; Chung, Wendy K.; Goldgar, David E.; Buys, Saundra S.; Janavicius, Ramunas; Tihomirova, Laima; Tung, Nadine; Dorfling, Cecilia M.; van Rensburg, Elizabeth J.; Neuhausen, Susan L.; Ding, Yuan Chun; Gerdes, Anne-Marie; Ejlertsen, Bent; Nielsen, Finn C.; Hansen, Thomas V. O.; Osorio, Ana; Benitez, Javier; Andres Conejero, Raquel; Segota, Ena; Weitzel, Jeffrey N.; Thelander, Margo; Peterlongo, Paolo; Radice, Paolo; Pensotti, Valeria; Dolcetti, Riccardo; Bonanni, Bernardo; Peissel, Bernard; Zaffaroni, Daniela; Scuvera, Giulietta; Manoukian, Siranoush; Varesco, Liliana; Capone, Gabriele L.; Papi, Laura; Ottini, Laura; Yannoukakos, Drakoulis; Konstantopoulou, Irene; Garber, Judy; Hamann, Ute; Donaldson, Alan; Brady, Angela; Brewer, Carole; Foo, Claire; Evans, D. Gareth; Frost, Debra; Eccles, Diana; Douglas, Fiona; Cook, Jackie; Adlard, Julian; Barwell, Julian; Walker, Lisa; Izatt, Louise; Side, Lucy E.; Kennedy, M. John; Tischkowitz, Marc; Rogers, Mark T.; Porteous, Mary E.; Morrison, Patrick J.; Platte, Radka; Eeles, Ros; Davidson, Rosemarie; Hodgson, Shirley; Cole, Trevor; Godwin, Andrew K.; Isaacs, Claudine; Claes, Kathleen; De Leeneer, Kim; Meindl, Alfons; Gehrig, Andrea; Wappenschmidt, Barbara; Sutter, Christian; Engel, Christoph; Niederacher, Dieter; Steinemann, Doris; Plendl, Hansjoerg; Kast, Karin; Rhiem, Kerstin; Ditsch, Nina; Arnold, Norbert; Varon-Mateeva, Raymonda; Schmutzler, Rita K.; Preisler-Adams, Sabine; Markov, Nadja Bogdanova; Wang-Gohrke, Shan; de Pauw, Antoine; Lefol, Cedrick; Lasset, Christine; Leroux, Dominique; Rouleau, Etienne; Damiola, Francesca; Dreyfus, Helene; Barjhoux, Laure; Golmard, Lisa; Uhrhammer, Nancy; Bonadona, Valerie; Sornin, Valerie; Bignon, Yves-Jean; Carter, Jonathan; Van Le, Linda; Piedmonte, Marion; DiSilvestro, Paul A.; de la Hoya, Miguel; Caldes, Trinidad; Nevanlinna, Heli; Aittomaki, Kristiina; Jager, Agnes; van den Ouweland, Ans M. W.; Kets, Carolien M.; Aalfs, Cora M.; van Leeuwen, Flora E.; Hogervorst, Frans B. L.; Meijers-Heijboer, Hanne E. J.; Oosterwijk, Jan C.; van Roozendaal, Kees E. P.; Rookus, Matti A.; Devilee, Peter; van der Luijt, Rob B.; Olah, Edith; Diez, Orland; Teule, Alex; Lazaro, Conxi; Blanco, Ignacio; Del Valle, Jesus; Jakubowska, Anna; Sukiennicki, Grzegorz; Gronwald, Jacek; Lubinski, Jan; Durda, Katarzyna; Jaworska-Bieniek, Katarzyna; Agnarsson, Bjarni A.; Maugard, Christine; Amadori, Alberto; Montagna, Marco; Teixeira, Manuel R.; Spurdle, Amanda B.; Foulkes, William; Olswold, Curtis; Lindor, Noralane M.; Pankratz, Vernon S.; Szabo, Csilla I.; Lincoln, Anne; Jacobs, Lauren; Corines, Marina; Robson, Mark; Vijai, Joseph; Berger, Andreas; Fink-Retter, Anneliese; Singer, Christian F.; Rappaport, Christine; Kaulich, Daphne Geschwantler; Pfeiler, Georg; Tea, Muy-Kheng; Greene, Mark H.; Mai, Phuong L.; Rennert, Gad; Imyanitov, Evgeny N.; Mulligan, Anna Marie; Glendon, Gord; Andrulis, Irene L.; Tchatchou, Sandrine; Toland, Amanda Ewart; Pedersen, Inge Sokilde; Thomassen, Mads; Kruse, Torben A.; Jensen, Uffe Birk; Caligo, Maria A.; Friedman, Eitan; Zidan, Jamal; Laitman, Yael; Lindblom, Annika; Melin, Beatrice; Arver, Brita; Loman, Niklas; Rosenquist, Richard; Olopade, Olufunmilayo I.; Nussbaum, Robert L.; Ramus, Susan J.; Nathanson, Katherine L.; Domchek, Susan M.; Rebbeck, Timothy R.; Arun, Banu K.; Mitchell, Gillian; Karlan, Beth Y.; Lester, Jenny; Orsulic, Sandra; Stoppa-Lyonnet, Dominique; Thomas, Gilles; Simard, Jacques; Couch, Fergus J.; Offit, Kenneth; Easton, Douglas F.; Chenevix-Trench, Georgia; Antoniou, Antonis C.; Mazoyer, Sylvie; Phelan, Catherine M.; Sinilnikova, Olga M.; Cox, David G.

    2015-01-01

    Introduction: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitoc

  18. An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers.

    NARCIS (Netherlands)

    Blein, S.; Bardel, C.; Danjean, V.; McGuffog, L.; Healey, S.; Barrowdale, D.; Lee, A.; Dennis, J.; Kuchenbaecker, K.B.; Soucy, P.; Terry, M.B.; Chung, W.K.; Goldgar, D.E.; Buys, S.S.; Janavicius, R.; Tihomirova, L.; Tung, N.; Dorfling, C.M.; Rensburg, E.J. van; Neuhausen, S.L.; Ding, Y.C.; Gerdes, A.M.; Ejlertsen, B.; Nielsen, F.C.; Hansen, T.V.; Osorio, A.; Benitez, J.; Conejero, R.A.; Segota, E.; Weitzel, J.N.; Thelander, M.; Peterlongo, P.; Radice, P.; Pensotti, V.; Dolcetti, R.; Bonanni, B.; Peissel, B.; Zaffaroni, D.; Scuvera, G.; Manoukian, S.; Varesco, L.; Capone, G.L.; Papi, L.; Ottini, L.; Yannoukakos, D.; Konstantopoulou, I.; Garber, J.; Hamann, U.; Donaldson, A.; Brady, A.; Brewer, C.; Foo, C.; Evans, D.G.; Frost, D.; Eccles, D.; Douglas, F.; Cook, J.; Adlard, J.; Barwell, J.; Walker, L.; Izatt, L.; Side, L.E.; Kennedy, M.J.; Tischkowitz, M.; Rogers, M.T.; Porteous, M.E.; Morrison, P.J.; Platte, R.; Eeles, R.; Davidson, R.; Hodgson, S.; Cole, T.; Godwin, A.K.; Isaacs, C.; Claes, K.; Leeneer, K. De; Meindl, A.; Gehrig, A.; Wappenschmidt, B.; Sutter, C.; Engel, C.; Niederacher, D.; Steinemann, D.; Plendl, H.; Kast, K.; Rhiem, K.; Ditsch, N.; Arnold, N.; Varon-Mateeva, R.; Schmutzler, R.K.; Preisler-Adams, S.; Markov, N.B.; Wang-Gohrke, S.; Pauw, A. de; Lefol, C.; Lasset, C.; Leroux, D.; Rouleau, E.; Damiola, F.; Dreyfus, H.; Barjhoux, L.; Golmard, L.; Uhrhammer, N.; Bonadona, V.; Sornin, V.; Bignon, Y.J.; Carter, J.; Le, L; Piedmonte, M.; DiSilvestro, P.A.; Hoya, M. de la; Caldes, T.; Nevanlinna, H.; Aittomaki, K.; Jager, A.; Ouweland, A.M. van den; Kets, C.M.; Aalfs, C.M.; Leeuwen, F.E. van; Hogervorst, F.B.; Meijers-Heijboer, H.E.; Oosterwijk, J.C.; Roozendaal, K.E. van; Rookus, M.A.; Devilee, P.; Luijt, R.B. van der; Olah, E.; Diez, O.; Teule, A.; Lazaro, C.; Blanco, I.; Valle, J.; Jakubowska, A.; Sukiennicki, G.; Gronwald, J.; Lubinski, J.; Durda, K.; Jaworska-Bieniek, K.; Agnarsson, B.A.; Maugard, C.; Amadori, A.; Montagna, M.; Teixeira, M.R.; Spurdle, A.B.; Foulkes, W.; Olswold, C.; Lindor, N.M.; Pankratz, V.S.; Szabo, C.I.; Lincoln, A.; Jacobs, L.; Corines, M.; Robson, M.; Vijai, J.; Berger, A.; Fink-Retter, A.; Singer, C.F.; Rappaport, C.; Kaulich, D.G.; Pfeiler, G.; Tea, M.K.; Greene, M.H.; Mai, P.L.; Rennert, G.; Imyanitov, E.N.; Mulligan, A.M.; Glendon, G.; Andrulis, I.L.; Tchatchou, S.; Toland, A.E.; Pedersen, I.S.; Thomassen, M.; Kruse, T.A.; Jensen, U.B.; Caligo, M.A.; Friedman, E.; Zidan, J.; Laitman, Y.; Lindblom, A.; Melin, B.; Arver, B.; Loman, N.; Rosenquist, R.; Olopade, O.I.; Nussbaum, R.L.; Ramus, S.J.; Nathanson, K.L.; Domchek, S.M.; Rebbeck, T.R.; Arun, B.K.; Mitchell, G.; Karlan, B.Y.; Lester, J.; Orsulic, S.; Stoppa-Lyonnet, D.; Thomas, G; Simard, J.; Couch, F.J.; Offit, K.; Easton, D.F.; Chenevix-Trench, G.; Antoniou, A.C.; Mazoyer, S.; Phelan, C.M.; Sinilnikova, O.M.; Cox, D.G.

    2015-01-01

    INTRODUCTION: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitoc

  19. Pathology of Breast and Ovarian Cancers among BRCA1 and BRCA2 Mutation Carriers: Results from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA)

    DEFF Research Database (Denmark)

    Mavaddat, Nasim; Barrowdale, Daniel; Andrulis, Irene L;

    2012-01-01

    BACKGROUND: Previously, small studies have found that BRCA1 and BRCA2 breast tumors differ in their pathology. Analysis of larger datasets of mutation carriers should allow further tumor characterization. METHODS: We used data from 4,325 BRCA1 and 2,568 BRCA2 mutation carriers to analyze the...

  20. Recurrent BRCA1 and BRCA2 mutations in breast cancer patients of African ancestry.

    Science.gov (United States)

    Zhang, Jing; Fackenthal, James D; Zheng, Yonglan; Huo, Dezheng; Hou, Ningqi; Niu, Qun; Zvosec, Cecilia; Ogundiran, Temidayo O; Hennis, Anselm J; Leske, Maria Cristina; Nemesure, Barbara; Wu, Suh-Yuh; Olopade, Olufunmilayo I

    2012-07-01

    Recurrent mutations constituted nearly three quarters of all BRCA1 mutations and almost half of all BRCA2 mutations identified in the first cohort of the Nigerian Breast Cancer Study. To further characterize breast/ovarian cancer risks associated with BRCA1/BRCA2 mutations in the African diaspora, we genotyped recurrent mutations among Nigerian, African American, and Barbadian breast cancer patients. A replication cohort of 356 Nigerian breast cancer patients was genotyped for 12 recurrent BRCA1/2 mutant alleles (Y101X, 1742insG, 4241delTG, M1775R, 4359insC, C64Y, 1623delTTAAA, Q1090X, and 943ins10 from BRCA1, and 1538delAAGA, 2630del11, and 9045delGAAA from BRCA2) by means of SNaPshot followed by direct sequencing or by direct sequencing alone. In addition, 260 African Americans and 118 Barbadians were genotyped for six of the recurrent BRCA1 mutations by SNaPshot assay. Of all the BRCA1/2 recurrent mutations we identified in the first cohort, six were identified in 11 patients in the replication study. These mutation carriers constitute 3.1 % [95 % Confidence Interval (CI) 1.6-5.5 %] of the replication cohort. By comparison, 6.9 % (95 % CI 4.7-9.7 %) of the discovery cohort carried BRCA1/2 recurrent mutations. For the subset of recurrent mutations we tested in breast cancer cases from Barbados or the United States, only two 943ins10 carriers were identified in African Americans. Nigerian breast cancer patients from Ibadan carry a broad and unique spectrum of BRCA1/2 mutations. Our data suggest that BRCA1/2 mutation testing limited to recurrent mutations is not sufficient to understand the BRCA1/2-associated breast cancer risk in African populations in the diaspora. As the cost of Sanger sequencing is considerably reduced, deploying innovative technologies such as high throughput DNA sequencing of BRCA1/2 and other cancer susceptibility genes will be essential for identifying high-risk individuals and families to reduce the burden of aggressive early onset breast

  1. Evaluation of a candidate breast cancer associated SNP in ERCC4 as a risk modifier in BRCA1 and BRCA2 mutation carriers. Results from the Consortium of Investigators of Modifiers of BRCA1/BRCA2 (CIMBA)

    DEFF Research Database (Denmark)

    Osorio, A; Milne, R L; Pita, G;

    2009-01-01

    Background:In this study we aimed to evaluate the role of a SNP in intron 1 of the ERCC4 gene (rs744154), previously reported to be associated with a reduced risk of breast cancer in the general population, as a breast cancer risk modifier in BRCA1 and BRCA2 mutation carriers.Methods:We have geno...

  2. Evaluation of a candidate breast cancer associated SNP in ERCC4 as a risk modifier in BRCA1 and BRCA2 mutation carriers. Results from the Consortium of Investigators of Modifiers of BRCA1/BRCA2 (CIMBA)

    DEFF Research Database (Denmark)

    Osorio, A.; Milne, R.L.; Pita, G.;

    2009-01-01

    BACKGROUND: In this study we aimed to evaluate the role of a SNP in intron 1 of the ERCC4 gene (rs744154), previously reported to be associated with a reduced risk of breast cancer in the general population, as a breast cancer risk modifier in BRCA1 and BRCA2 mutation carriers. METHODS: We have g...

  3. Low prevalence of HER2 positivity amongst BRCA1 and BRCA2 mutation carriers and in primary BRCA screens.

    Science.gov (United States)

    Evans, D G; Lalloo, F; Howell, S; Verhoef, S; Woodward, E R; Howell, A

    2016-02-01

    The aim of this study is to delineate more clearly the prevalence of HER2+ breast cancer in women with germline BRCA1/2 mutations. For this purpose, we analysed primary mutation screens on women with breast cancer with unequivocal HER2 amplification and assessed the proportion of BRCA1 and BRCA2 breast cancers that were HER2+ comparing this with the existing literature. The results are that 1063 primary BRCA screens had confirmed tumour HER2 status. If HER2+ only 2.5 % (4/156) and 3.2 % (5/156) of women had a BRCA1 or BRCA2 mutation identified respectively; compared to 27.7 % (115/415) and 8.2 % (34/415) with triple negative tumours. Only 2.1 % (4/195) women with BRCA1-related breast cancer had HER2 amplified breast cancers rising to 6.8 % (n = 12, p = 0.04) in BRCA2. These rates are in keeping with most of the existing literature except a recent large multicenter report which documented higher rates but with no control group. The study concluded that true HER2-amplified breast cancers are rare amongst BRCA1 mutation carriers and are less common in BRCA2 than background rates. PMID:26888723

  4. Genetic Variation at 9p22.2 and Ovarian Cancer Risk for BRCA1 and BRCA2 Mutation Carriers

    DEFF Research Database (Denmark)

    Ramus, Susan J; Kartsonaki, Christiana; Gayther, Simon A;

    2011-01-01

    Background Germline mutations in the BRCA1 and BRCA2 genes are associated with increased risks of breast and ovarian cancers. Although several common variants have been associated with breast cancer susceptibility in mutation carriers, none have been associated with ovarian cancer susceptibility....

  5. Genetic variation at 9p22.2 and ovarian cancer risk for BRCA1 and BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Ramus, Susan J; Kartsonaki, Christiana; Gayther, Simon A;

    2011-01-01

    Germline mutations in the BRCA1 and BRCA2 genes are associated with increased risks of breast and ovarian cancers. Although several common variants have been associated with breast cancer susceptibility in mutation carriers, none have been associated with ovarian cancer susceptibility. A genome-w...

  6. Prevalence of BRCA1 and BRCA2 Germline Mutations in Breast Cancer Women of Multiple Ethnic Region in Northwest China

    NARCIS (Netherlands)

    Ou, Jianghua; Wu, Tao; Sijmons, Rolf; Ni, Duo; Xu, Wenting; Upur, Halmurat

    2013-01-01

    Purpose: The aim of this study is to further understand the status of BRCA1 and BRCA2 mutation among Chinese high-risk breast cancer patients in multiple-ethnic regions of China. Methods: A total of 79 blood samples of high-risk breast cancer patients from Xinjiang Uyghur autonomous region were anal

  7. Increased Chromosomal Radiosensitivity in Women Carrying BRCA1/BRCA2 Mutations Assessed With the G2 Assay

    International Nuclear Information System (INIS)

    Purpose: Several in vitro studies suggest that BRCA1 and BRCA2 mutation carriers present increased sensitivity to ionizing radiation. Different assays for the assessment of deoxyribonucleic acid double-strand break repair capacity have been used, but results are rather inconsistent. Given the concerns about the possible risks of breast screening with mammography in mutation carrier women and the potentially damaging effects of radiotherapy, the purpose of this study was to further investigate the radiosensitivity of this population. Methods and Materials: The G2 chromosomal radiosensitivity assay was used to assess chromosomal breaks in lymphocyte cultures after exposure to 1 Gy. A group of familiar breast cancer patients carrying a mutation in the BRCA1 or BRCA2 gene (n = 15) and a group of healthy mutation carriers (n = 5) were investigated and compared with a reference group of healthy women carrying no mutation (n = 21). Results: BRCA1 and BRCA2 mutation carriers had a significantly higher number of mean chromatid breaks per cell (p = 0.006) and a higher maximum number of breaks (p = 0.0001) as compared with their matched controls. Both healthy carriers and carriers with a cancer history were more radiosensitive than controls (p = 0.002 and p = 0.025, respectively). Age was not associated with increased radiosensitivity (p = 0.868). Conclusions: Our results indicate that BRCA1 and BRCA2 mutation carriers show enhanced radiosensitivity, presumably because of the involvement of the BRCA genes in deoxyribonucleic acid repair and cell cycle control mechanisms.

  8. Increased risk of male cancer and identification of a potential prostate cancer cluster region in BRCA2

    DEFF Research Database (Denmark)

    Roed Nielsen, Henriette; Petersen, Janne; Therkildsen, Christina; Skytte, Anne-Bine; Nilbert, Mef

    2016-01-01

    BACKGROUND: The risk of cancer in men from BRCA1 and BRCA2 families is relevant to define to motivate genetic testing and optimize recommendations for surveillance. MATERIAL AND METHODS: We assessed the risk of cancer in male mutation carriers and their first-degree relatives in 290 BRCA1 and BRC...

  9. Analysis of large deletions in BRCA1, BRCA2 and PALB2 genes in Finnish breast and ovarian cancer families

    Directory of Open Access Journals (Sweden)

    Sólyom Szilvia

    2008-05-01

    Full Text Available Abstract Background BRCA1 and BRCA2 are the two most important genes associated with familial breast and ovarian cancer susceptibility. In addition, PALB2 has recently been identified as a breast cancer susceptibility gene in several populations. Here we have evaluated whether large genomic rearrangement in these genes could explain some of Finnish breast and/or ovarian cancer families. Methods Altogether 61 index patients of Northern Finnish breast and/or ovarian cancer families were analyzed by Multiplex ligation-dependent probe amplification (MLPA method in order to identify exon deletions and duplications in BRCA1, BRCA2 and PALB2. The families have been comprehensively screened for germline mutation in these genes by conventional methods of mutation analysis and were found negative. Results We identified one large deletion in BRCA1, deleting the most part of the gene (exon 1A-13 in one family with family history of ovarian cancer. No large genomic rearrangements were identified in either BRCA2 or PALB2. Conclusion In Finland, women eligible for BRCA1 or BRCA2 mutation screening, when found negative, could benefit from screening for large genomic rearrangements at least in BRCA1. On the contrary, the genomic rearrangements in PALB2 seem not to contribute to the hereditary breast cancer susceptibility.

  10. PGD for hereditary breast and ovarian cancer : the route to universal tests for BRCA1 and BRCA2 mutation carriers

    NARCIS (Netherlands)

    Drusedau, Marion; Dreesen, Jos C.; Derks-Smeets, Inge; Coonen, Edith; van Golde, Ron; van Echten-Arends, Jannie; Kastrop, Peter M. M.; Blok, Marinus J.; Gomez-Garcia, Encarna; Geraedts, Joep P.; Smeets, Hubert J.; de Die-Smulders, Christine E.; Paulussen, Aimee D.

    2013-01-01

    Preimplantation Genetic Diagnosis (PGD) is a method of testing in vitro embryos as an alternative to prenatal diagnosis with possible termination of pregnancy in case of an affected child. Recently, PGD for hereditary breast and ovarian cancer caused by BRCA1 and BRCA2 mutations has found its way in

  11. The androgen receptor CAG repeat polymorphism and modification of breast cancer risk in BRCA1 and BRCA2 mutation carriers

    International Nuclear Information System (INIS)

    The androgen receptor (AR) gene exon 1 CAG repeat polymorphism encodes a string of 9–32 glutamines. Women with germline BRCA1 mutations who carry at least one AR allele with 28 or more repeats have been reported to have an earlier age at onset of breast cancer. A total of 604 living female Australian and British BRCA1 and/or BRCA2 mutation carriers from 376 families were genotyped for the AR CAG repeat polymorphism. The association between AR genotype and disease risk was assessed using Cox regression. AR genotype was analyzed as a dichotomous covariate using cut-points previously reported to be associated with increased risk among BRCA1 mutation carriers, and as a continuous variable considering smaller allele, larger allele and average allele size. There was no evidence that the AR CAG repeat polymorphism modified disease risk in the 376 BRCA1 or 219 BRCA2 mutation carriers screened successfully. The rate ratio associated with possession of at least one allele with 28 or more CAG repeats was 0.74 (95% confidence interval 0.42–1.29; P = 0.3) for BRCA1 carriers, and 1.12 (95% confidence interval 0.55–2.25; P = 0.8) for BRCA2 carriers. The AR exon 1 CAG repeat polymorphism does not appear to have an effect on breast cancer risk in BRCA1 or BRCA2 mutation carriers

  12. Germline mutation in BRCA1 or BRCA2 and ten-year survival for women diagnosed with epithelial ovarian cancer

    DEFF Research Database (Denmark)

    Candido-dos-Reis, Francisco J; Song, Honglin; Goode, Ellen L; Cunningham, Julie M; Fridley, Brooke L; Larson, Melissa C; Alsop, Kathryn; Dicks, Ed; Harrington, Patricia; Ramus, Susan J; de Fazio, Anna; Mitchell, Gillian; Fereday, Sian; Bolton, Kelly L; Gourley, Charlie; Michie, Caroline; Karlan, Beth; Lester, Jenny; Walsh, Christine; Cass, Ilana; Olsson, Håkan; Gore, Martin; Benitez, Javier J; Garcia, Maria J; Andrulis, Irene; Mulligan, Anna Marie; Glendon, Gord; Blanco, Ignacio; Lazaro, Conxi; Whittemore, Alice S; McGuire, Valerie; Sieh, Weiva; Montagna, Marco; Alducci, Elisa; Sadetzki, Siegal; Chetrit, Angela; Kwong, Ava; Kjaer, Susanne K; Jensen, Allan; Høgdall, Estrid; Neuhausen, Susan; Nussbaum, Robert; Daly, Mary; Greene, Mark H; Mai, Phuong L; Loud, Jennifer T; Moysich, Kirsten; Toland, Amanda E; Lambrechts, Diether; Ellis, Steve; Frost, Debra; Brenton, James D; Tischkowitz, Marc; Easton, Douglas F; Antoniou, Antonis; Chenevix-Trench, Georgia; Gayther, Simon A; Bowtell, David; Pharoah, Paul D P

    2015-01-01

    PURPOSE: To analyze the effect of germline mutations in BRCA1 and BRCA2 on mortality in patients with ovarian cancer up to 10 years after diagnosis. EXPERIMENTAL DESIGN: We used unpublished survival time data for 2,242 patients from two case-control studies and extended survival time data for 4......,314 patients from previously reported studies. All participants had been screened for deleterious germline mutations in BRCA1 and BRCA2. Survival time was analyzed for the combined data using Cox proportional hazard models with BRCA1 and BRCA2 as time-varying covariates. Competing risks were analyzed using...... Fine and Gray model. RESULTS: The combined 10-year overall survival rate was 30% [95% confidence interval (CI), 28%-31%] for non-carriers, 25% (95% CI, 22%-28%) for BRCA1 carriers, and 35% (95% CI, 30%-41%) for BRCA2 carriers. The HR for BRCA1 was 0.53 at time zero and increased over time becoming...

  13. Analysis of large deletions in BRCA1, BRCA2 and PALB2 genes in Finnish breast and ovarian cancer families

    International Nuclear Information System (INIS)

    BRCA1 and BRCA2 are the two most important genes associated with familial breast and ovarian cancer susceptibility. In addition, PALB2 has recently been identified as a breast cancer susceptibility gene in several populations. Here we have evaluated whether large genomic rearrangement in these genes could explain some of Finnish breast and/or ovarian cancer families. Altogether 61 index patients of Northern Finnish breast and/or ovarian cancer families were analyzed by Multiplex ligation-dependent probe amplification (MLPA) method in order to identify exon deletions and duplications in BRCA1, BRCA2 and PALB2. The families have been comprehensively screened for germline mutation in these genes by conventional methods of mutation analysis and were found negative. We identified one large deletion in BRCA1, deleting the most part of the gene (exon 1A-13) in one family with family history of ovarian cancer. No large genomic rearrangements were identified in either BRCA2 or PALB2. In Finland, women eligible for BRCA1 or BRCA2 mutation screening, when found negative, could benefit from screening for large genomic rearrangements at least in BRCA1. On the contrary, the genomic rearrangements in PALB2 seem not to contribute to the hereditary breast cancer susceptibility

  14. Association of type and location of BRCA1 and BRCA2 mutations with risk of breast and ovarian cancer

    DEFF Research Database (Denmark)

    Rebbeck, Timothy R; Mitra, Nandita; Wan, Fei;

    2015-01-01

    IMPORTANCE: Limited information about the relationship between specific mutations in BRCA1 or BRCA2 (BRCA1/2) and cancer risk exists. OBJECTIVE: To identify mutation-specific cancer risks for carriers of BRCA1/2. DESIGN, SETTING, AND PARTICIPANTS: Observational study of women who were ascertained...

  15. Association of type and location of BRCA1 and BRCA2 mutations with risk of breast and ovarian cancer

    NARCIS (Netherlands)

    R. Rebbeck (Timothy); N. Mitra (Nandita); F. Wan (Fei); O. Sinilnikova (Olga); S. Healey (Sue); L. McGuffog (Lesley); G. Chenevix-Trench (Georgia); D.F. Easton (Douglas); A.C. Antoniou (Antonis C.); K.L. Nathanson (Katherine); Y. Laitman (Yael); A. Kushnir (Anya); S. Paluch-Shimon (Shani); R. Berger (Raanan); J. Zidan (Jamal); E. Friedman (Eitan); H. Ehrencrona (Hans); M. Stenmark-Askmalm (Marie); Z. Einbeigi (Zakaria); N. Loman (Niklas); K. Harbst (Katja); J. Rantala (Johanna); B. Melin (Beatrice); D. Huo (Dezheng); O.I. Olopade (Olofunmilayo); J.L. Seldon (Joyce); P.A. Ganz (Patricia); R.L. Nussbaum (Robert L.); S. Chan (Salina); K. Odunsi (Kunle); S.A. Gayther (Simon); S.M. Domchek (Susan); B.K. Arun (Banu); K.H. Lu (Karen); G. Mitchell (Gillian); B. Karlan; C.S. Walsh (Christine); K.J. Lester (Kathryn); A.K. Godwin (Andrew); S.S. Pathak; E.B. Ross (Eric); M.J. Daly (Mark); A.S. Whittemore (Alice); E.M. John (Esther); A. Miron (Alexander); M.B. Terry (Mary Beth); W.K. Chung (Wendy K.); D. Goldgar (David); S.S. Buys (Saundra); R. Janavicius (Ramunas); L. Tihomirova (Laima); N. Tung (Nadine); C.M. Dorfling (Cecilia); E.J. van Rensburg (Elizabeth); L. Steele (Linda); S.L. Neuhausen (Susan); Y.C. Ding (Yuan); B. Ejlertsen (Bent); A-M. Gerdes (Anne-Marie); T.V.O. Hansen (Thomas); T. Ramon Y Cajal; A. Osorio (Ana); J. Benítez (Javier); J. Godino (Javier); M.I. Tejada; M. Duran (Mercedes); J.N. Weitzel (Jeffrey); K.A. Bobolis (Kristie A.); S.R. Sand (Sharon); A. Fontaine (Annette); A. Savarese (Antonella); B. Pasini (Barbara); B. Peissel (Bernard); B. Bonnani (Bernardo); D. Zaffaroni (Daniela); F. Vignolo-Lutati (Francesca); G. Scuvera (Giulietta); G. Giannini (Giuseppe); L. Bernard (Loris); M. Genuardi (Maurizio); P. Radice (Paolo); R. Dolcetti (Riccardo); S. Manoukian (Siranoush); V. Pensotti (Valeria); V. Gismondi (Viviana); D. Yannoukakos (Drakoulis); F. Fostira (Florentia); J. Garber (Judy); D. Torres (Diana); M.U. Rashid (Muhammad); U. Hamann (Ute); S. Peock (Susan); D. Frost (Debra); R. Platte (Radka); D.G. Evans (Gareth); R. Eeles (Rosalind); R. Davidson (Rosemarie); D. Eccles (Diana); T. Cole (Trevor); J. Cook (Jackie); C. Brewer (Carole); S. Hodgson (Shirley); P.J. Morrison (Patrick); L.J. Walker (Lisa); M.E. Porteous (Mary); M.J. Kennedy (John); L. Izatt (Louise); L. Adlard; A. Donaldson (Alan); S.D. Ellis (Steve); P. Sharma (Priyanka); R.K. Schmutzler (Rita); B. Wapenschmidt (Barbara); A. Becker (Alexandra); K. Rhiem (Kerstin); E. Hahnen (Eric); C. Engel (Christoph); A. Meindl (Alfons); S. Engert (Stefanie); N. Ditsch (Nina); N. Arnold (Norbert); H. Plendl (Hansjoerg); C. Mundhenke (Christoph); D. Niederacher (Dieter); M.C. Fleisch (Markus); C. Sutter (Christian); C.R. Bartram; N. Dikow (Nicola); S. Wang-Gohrke (Shan); D. Gadzicki (Dorothea); D. Steinemann (Doris); K. Kast (Karin); M. Beer (Marit); R. Varon-Mateeva (Raymonda); P.A. Gehrig (Paola A.); B.H.F. Weber (Bernhard); D. Stoppa-Lyonnet (Dominique); M. Belotti (Muriel); M. Gauthier-Villars (Marion); F. Damiola (Francesca); N. Boutry-Kryza (N.); C. Lasset (Christine); H. Sobol (Hagay); J.-P. Peyrat; D.W. Muller (Danièle); J.P. Fricker (Jean Pierre); M.-A. Collonge-Rame; I. Mortemousque (Isabelle); C. Nogues (Catherine); E. Rouleau (Etienne); C. Isaacs (Claudine); A. de Paepe (Anne); B. Poppe (Bruce); K. Claes (Kathleen); K. De Leeneer (Kim); M. Piedmonte (Marion); G. Rodriguez (Gustavo); K. Wakely (Katie); J.F. Boggess (John); S.V. Blank (Stephanie); J. Basil (Jack); M. Azodi (Masoud); K.-A. Phillips (Kelly-Anne); T. Caldes (Trinidad); M. de La Hoya (Miguel); A. Romero (Atocha); H. Nevanlinna (Heli); K. Aittomäki (Kristiina); A.H. van der Hout (Annemarie); F.B.L. Hogervorst (Frans); S. Verhoef; J.M. Collee (Margriet); C.M. Seynaeve (Caroline); J.C. Oosterwijk (Jan); J.J. Gille (Johan); J.T. Wijnen (Juul); E.B. Gómez García (Encarna); C.M. Kets; M.G.E.M. Ausems (Margreet); C.M. Aalfs (Cora); P. Devilee (Peter); A.R. Mensenkamp (Arjen); A. Kwong (Ava); E. Olah; J. Papp (Janos); O. Díez (Orland); C. Lazaro (Conxi); E. Darder (Esther); I. Blanco (Ignacio); M. Salinas; A. Jakubowska (Anna); J. Lubinski (Jan); J. Gronwald (Jacek); K. Jaworska-Bieniek (Katarzyna); K. Durda (Katarzyna); G. Sukiennicki (Grzegorz); T. Huzarski (Tomasz); T. Byrski (Tomasz); C. Cybulski (Cezary); A. Toloczko-Grabarek (Aleksandra); E. Złowocka-Perłowska (Elzbieta); J. Menkiszak (Janusz); A. Arason (Adalgeir); R.B. Barkardottir (Rosa); J. Simard (Jacques); R. Laframboise (Rachel)

    2015-01-01

    textabstractImportance: Limited information about the relationship between specific mutations in BRCA1 or BRCA2 (BRCA1/2) and cancer risk exists. Objective: To identify mutation-specific cancer risks for carriers of BRCA1/2. Design, Setting, and Participants: Observational study ofwomen whowere asce

  16. Ovarian cancer susceptibility alleles and risk of ovarian cancer in BRCA1 and BRCA2 mutation carriers

    NARCIS (Netherlands)

    Ramus, S.J.; Antoniou, A.C.; Kuchenbaecker, K.B.; Soucy, P.; Beesley, J.; Chen, X.; McGuffog, L.; Sinilnikova, O.M.; Healey, S.; Barrowdale, D.; Lee, A.; Thomassen, M.; Gerdes, A.M.; Kruse, T.A.; Jensen, U.B.; Skytte, A.B.; Caligo, M.A.; Liljegren, A.; Lindblom, A.; Olsson, H.; Kristoffersson, U.; Stenmark-Askmalm, M.; Melin, B.; Swe, B.; Domchek, S.M.; Nathanson, K.L.; Rebbeck, T.R.; Jakubowska, A.; Lubinski, J.; Jaworska, K.; Durda, K.; Zlowocka, E.; Gronwald, J.; Huzarski, T.; Byrski, T.; Cybulski, C.; Toloczko-Grabarek, A.; Osorio, A.; Benitez, J.; Duran, M.; Tejada, M.I.; Hamann, U.; Rookus, M.; Leeuwen, F.E. van; Aalfs, C.M.; Meijers-Heijboer, H.E.; Asperen, C.J. van; Roozendaal, K.E. van; Hoogerbrugge-van der Linden, N.; Collee, J.M.; Kriege, M.; Luijt, R.B. van der; Hebon, .; Embrace, .; Peock, S.; Frost, D.; Ellis, S.D.; Platte, R.; Fineberg, E.; Evans, D.G.; Lalloo, F.; Jacobs, C.; Eeles, R.; Adlard, J.; Davidson, R.; Eccles, D.; Cole, T.; Cook, J.; Paterson, J.; Douglas, F.; Brewer, C.; Hodgson, S.; Morrison, P.J.; Walker, L.; Porteous, M.E.; Kennedy, M.J.; Pathak, H.; Godwin, A.K.; Stoppa-Lyonnet, D.; Caux-Moncoutier, V.; Pauw, A. de; Gauthier-Villars, M.; Mazoyer, S.; Leone, M.; Calender, A.; Lasset, C.; Bonadona, V.; Hardouin, A.; Berthet, P.; Bignon, Y.J.; Uhrhammer, N.; Faivre, L.; Loustalot, C.; Gemo, .; Buys, S.; Daly, M.; Miron, A.; Terry, M.B.; Chung, W.K.; John, E.M.; Ligtenberg, M.J.

    2012-01-01

    Germline mutations in BRCA1 and BRCA2 are associated with increased risks of breast and ovarian cancer. A genome-wide association study (GWAS) identified six alleles associated with risk of ovarian cancer for women in the general population. We evaluated four of these loci as potential modifiers of

  17. Ovarian cancer susceptibility alleles and risk of ovarian cancer in BRCA1 and BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Ramus, Susan J; Antoniou, Antonis C; Kuchenbaecker, Karoline B;

    2012-01-01

    Germline mutations in BRCA1 and BRCA2 are associated with increased risks of breast and ovarian cancer. A genome-wide association study (GWAS) identified six alleles associated with risk of ovarian cancer for women in the general population. We evaluated four of these loci as potential modifiers ...

  18. Candidate genetic modifiers for breast and ovarian cancer risk in BRCA1 and BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Peterlongo, Paolo; Chang-Claude, Jenny; Moysich, Kirsten B;

    2015-01-01

    BACKGROUND: BRCA1 and BRCA2 mutation carriers are at substantially increased risk for developing breast and ovarian cancer. The incomplete penetrance coupled with the variable age at diagnosis in carriers of the same mutation suggests the existence of genetic and nongenetic modifying factors. In ...

  19. Prostate screening uptake in Australian BRCA1 and BRCA2 carriers

    Directory of Open Access Journals (Sweden)

    McKinley Joanne M

    2007-09-01

    Full Text Available Abstract Men who carry mutations in BRCA1 or BRCA2 are at increased risk for prostate cancer. However the efficacy of prostate screening in this setting is uncertain and limited data exists on the uptake of prostate screening by mutation carriers. This study prospectively evaluated uptake of prostate cancer screening in a multi-institutional cohort of mutation carriers. Subjects were unaffected male BRCA1 and BRCA2 mutation carriers, aged 40–69 years, enrolled in the Kathleen Cuningham Consortium for Research into Familial Breast Cancer (kConFab and who had completed a mailed, self-report follow-up questionnaire 3 yearly after study entry. Of the 75 male carriers in this study, only 26 (35% had elected to receive their mutation result. Overall, 51 (68% did not recall having received a recommendation to have prostate screening because of their family history, but 41 (55% had undergone a prostate specific antigen (PSA test and 32 (43% a digital rectal examination (DRE in the previous 3 years. Those who were aware of their mutation result were more likely to have received a recommendation for prostate screening (43 vs. 6%, p = 0.0001, and to have had a PSA test (77 vs. 43%, p = 0.005 and a DRE (69 vs. 29%, p = 0.001 in the previous 3 years. The majority of unaffected males enrolled in kConFab with a BRCA1/2 mutation have not sought out their mutation result. However, of those aware of their positive mutation status, most have undergone at least one round of prostate screening in the previous 3 years.

  20. Age and Geographical Distribution in Families with BRCA1/BRCA2 Mutations in the Slovak Republic

    Directory of Open Access Journals (Sweden)

    Ciernikova Sona

    2006-12-01

    Full Text Available Abstract Molecular diagnostics of hereditary breast and/or ovarian cancer is mainly based on detection of BRCA1 and BRCA2 germline mutations in suspected families. The aim of the study was to determine the frequency, age and geographical distribution in 130 Slovak hereditary breast and ovarian cancer (HBOC families diagnosed within the years 2000-2004. Mutation screening was performed by single-strand conformation polymorphism (SSCP, heteroduplex analysis (HDA and sequencing of PCR products showing an abnormal migration pattern. Twenty of 130 (15.6% HBOC suspected families were found to carry mutations in BRCA1 or BRCA2 genes. The glossary data from the National Cancer Registry of Slovakia (NCRS were compared with the results from HBOC suspected kindreds. Age distribution of breast cancer onset in our study group showed the highest proportion of onset in HBC families within the 5th decade of life, while NCRS reports at least a ten year later onset. These findings confirmed that cases of breast cancer under 50 years of age can be used as one of the principal criteria to assign a family as a hereditary breast and/or ovarian cancer kindred. In contrast with unselected ovarian cancer cases, about 75% of all HOC index cases were diagnosed between 40 and 49 years of age. To study the geographical distribution of hereditary breast and/or ovarian cancer, Slovakia was divided into three parts. The distribution of HBOC suspected families approximately follows this division, with an increasing number in the western area of the country.

  1. Regulation of Rad51-Mediated Homologous Recombination by BRCA2, DSS1 and RAD52

    DEFF Research Database (Denmark)

    Rants, Louise Olthaver Juhl

    involved with the proteasome. In U. maydis, the Rad52 orthologue seems relegated to a less prominent role than in Saccharomyces cerevisiae, similar to what is found in human cells. We find that Rad52 functionally overlaps with Brh2-ΔNBD, and Rad52 colocalizes with both Brh2 and Rfa1 (subunit of RPA) in...

  2. Screening for large rearrangements of the BRCA2 gene in Spanish families with breast/ovarian cancer.

    Science.gov (United States)

    Gutiérrez-Enríquez, Sara; de la Hoya, Miguel; Martínez-Bouzas, Cristina; Sanchez de Abajo, Ana; Ramón y Cajal, Teresa; Llort, Gemma; Blanco, Ignacio; Beristain, Elena; Díaz-Rubio, Eduardo; Alonso, Carmen; Tejada, María-Isabel; Caldés, Trinidad; Diez, Orland

    2007-05-01

    Germ-line mutations in BRCA1 and BRCA2 are responsible for about 30-60% of the hereditary breast and ovarian cancer (HBOC). A large number of point mutations have been described in both genes. However, large deletions and duplications that disrupt one or more exons are overlooked by point mutation detection approaches. Over the past years several rearrangements have been identified in BRCA1, while few studies have been designed to screen this type of mutations in BRCA2. Our aim was to estimate the prevalence of large genomic rearrangements in the BRCA2 gene in Spanish breast/ovarian cancer families. The multiplex ligation-dependent probe amplification (MLPA) was employed to search gross deletions or duplications of BRCA2 in 335 Spanish moderate to high-risk breast/ovarian cancer families previously screened negative for point mutations by conventional methods. Four different and novel large genomic alterations were consistently identified by MLPA in five families, respectively: deletions of exon 2, exons 10-12 and exons 15-16 and duplication of exon 20 (in two families). RT-PCR experiments confirmed the deletion of exons 15-16. All patients harbouring a genomic rearrangement were members of high-risk families, with three or more breast/ovarian cancer cases or the presence of breast cancer in males. We provide evidence that the BRCA2 rearrangements seem to account for a relatively small proportion of familial breast cancer cases in Spanish population. The screening for these alterations as part of the comprehensive genetic testing can be recommended, especially in multiple case breast/ovarian families and families with male breast cancer cases. PMID:17063271

  3. Several tetratricopeptide repeat (TPR) motifs of FANCG are required for assembly of the BRCA2/D1-D2-G-X3 complex, FANCD2 monoubiquitylation and phleomycin resistance

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, James B. [Molecular Oncology and Stem Cell Research Group, School of Biological Sciences, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB (United Kingdom); Blom, Eric [Department of Clinical Genetics and Human Genetics, VU University Medical Center, Van der Boechorststraat 7, NL-1081 BT Amsterdam (Netherlands); Cunningham, Ryan; Xiao, Yuxuan [Molecular Oncology and Stem Cell Research Group, School of Biological Sciences, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB (United Kingdom); Kupfer, Gary M. [Departments of Pediatrics and Pathology, Yale University School of Medicine, Section of Hematology/Oncology, 333 Cedar Street, New Haven, CT 0652 (United States); Jones, Nigel J., E-mail: njjones@liv.ac.uk [Molecular Oncology and Stem Cell Research Group, School of Biological Sciences, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB (United Kingdom)

    2010-07-07

    The Fanconi anaemia (FA) FANCG protein is an integral component of the FA nuclear core complex that is required for monoubiquitylation of FANCD2. FANCG is also part of another protein complex termed D1-D2-G-X3 that contains FANCD2 and the homologous recombination repair proteins BRCA2 (FANCD1) and XRCC3. Formation of the D1-D2-G-X3 complex is mediated by serine-7 phosphorylation of FANCG and occurs independently of the FA core complex and FANCD2 monoubiquitylation. FANCG contains seven tetratricopeptide repeat (TPR) motifs that mediate protein-protein interactions and here we show that mutation of several of the TPR motifs at a conserved consensus residue ablates the in vivo binding activity of FANCG. Expression of mutated TPR1, TPR2, TPR5 and TPR6 in Chinese hamster fancg mutant NM3 fails to functionally complement its hypersensitivities to mitomycin C (MMC) and phleomycin and fails to restore FANCD2 monoubiquitylation. Using co-immunoprecipitation analysis, we demonstrate that these TPR-mutated FANCG proteins fail to interact with BRCA2, XRCC3, FANCA or FANCF. The interactions of other proteins in the D1-D2-G-X3 complex are also absent, including the interaction of BRCA2 with both the monoubiquitylated (FANCD2-L) and non-ubiquitylated (FANCD2-S) isoforms of FANCD2. Interestingly, a mutation of TPR7 (R563E), that complements the MMC and phleomycin hypersensitivity of human FA-G EUFA316 cells, fails to complement NM3, despite the mutated FANCG protein co-precipitating with FANCA, BRCA2 and XRCC3. Whilst interaction of TPR7-mutated FANCG with FANCF does appear to be reduced in NM3, FANCD2 is monoubiquitylated suggesting that sub-optimal interactions of FANCG in the core complex and the D1-D2-G-X3 complex are responsible for the observed MMC- and phleomycin-hypersensitivity, rather than a defect in FANCD2 monoubiquitylation. Our data demonstrate that FANCG functions as a mediator of protein-protein interactions and is vital for the assembly of multi-protein complexes

  4. Several tetratricopeptide repeat (TPR) motifs of FANCG are required for assembly of the BRCA2/D1-D2-G-X3 complex, FANCD2 monoubiquitylation and phleomycin resistance

    International Nuclear Information System (INIS)

    The Fanconi anaemia (FA) FANCG protein is an integral component of the FA nuclear core complex that is required for monoubiquitylation of FANCD2. FANCG is also part of another protein complex termed D1-D2-G-X3 that contains FANCD2 and the homologous recombination repair proteins BRCA2 (FANCD1) and XRCC3. Formation of the D1-D2-G-X3 complex is mediated by serine-7 phosphorylation of FANCG and occurs independently of the FA core complex and FANCD2 monoubiquitylation. FANCG contains seven tetratricopeptide repeat (TPR) motifs that mediate protein-protein interactions and here we show that mutation of several of the TPR motifs at a conserved consensus residue ablates the in vivo binding activity of FANCG. Expression of mutated TPR1, TPR2, TPR5 and TPR6 in Chinese hamster fancg mutant NM3 fails to functionally complement its hypersensitivities to mitomycin C (MMC) and phleomycin and fails to restore FANCD2 monoubiquitylation. Using co-immunoprecipitation analysis, we demonstrate that these TPR-mutated FANCG proteins fail to interact with BRCA2, XRCC3, FANCA or FANCF. The interactions of other proteins in the D1-D2-G-X3 complex are also absent, including the interaction of BRCA2 with both the monoubiquitylated (FANCD2-L) and non-ubiquitylated (FANCD2-S) isoforms of FANCD2. Interestingly, a mutation of TPR7 (R563E), that complements the MMC and phleomycin hypersensitivity of human FA-G EUFA316 cells, fails to complement NM3, despite the mutated FANCG protein co-precipitating with FANCA, BRCA2 and XRCC3. Whilst interaction of TPR7-mutated FANCG with FANCF does appear to be reduced in NM3, FANCD2 is monoubiquitylated suggesting that sub-optimal interactions of FANCG in the core complex and the D1-D2-G-X3 complex are responsible for the observed MMC- and phleomycin-hypersensitivity, rather than a defect in FANCD2 monoubiquitylation. Our data demonstrate that FANCG functions as a mediator of protein-protein interactions and is vital for the assembly of multi-protein complexes

  5. Pathology of breast and ovarian cancers among BRCA1 and BRCA2 mutation carriers: results from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA)

    Science.gov (United States)

    Mavaddat, Nasim; Barrowdale, Daniel; Andrulis, Irene L.; Domchek, Susan M.; Eccles, Diana; Nevanlinna, Heli; Ramus, Susan J.; Spurdle, Amanda; Robson, Mark; Sherman, Mark; Mulligan, Anna Marie; Couch, Fergus J.; Engel, Christoph; McGuffog, Lesley; Healey, Sue; Sinilnikova, Olga M.; Southey, Melissa C.; Terry, Mary Beth; Goldgar, David; O’Malley, Frances; John, Esther M.; Janavicius, Ramunas; Tihomirova, Laima; Hansen, Thomas v O; Nielsen, Finn C.; Osorio, Ana; Stavropoulou, Alexandra; Benítez, Javier; Manoukian, Siranoush; Peissel, Bernard; Barile, Monica; Volorio, Sara; Pasini, Barbara; Dolcetti, Riccardo; Putignano, Anna Laura; Ottini, Laura; Radice, Paolo; Hamann, Ute; Rashid, Muhammad U.; Hogervorst, Frans B.; Kriege, Mieke; van der Luijt, Rob B.; Peock, Susan; Frost, Debra; Evans, D. Gareth; Brewer, Carole; Walker, Lisa; Rogers, Mark T.; Side, Lucy E.; Houghton, Catherine; Weaver, JoEllen; Godwin, Andrew K.; Schmutzler, Rita K.; Wappenschmidt, Barbara; Meindl, Alfons; Kast, Karin; Arnold, Norbert; Niederacher, Dieter; Sutter, Christian; Deissler, Helmut; Gadzicki, Doroteha; Preisler-Adams, Sabine; Varon-Mateeva, Raymonda; Schönbuchner, Ines; Gevensleben, Heidrun; Stoppa-Lyonnet, Dominique; Belotti, Muriel; Barjhoux, Laure; Isaacs, Claudine; Peshkin, Beth N.; Caldes, Trinidad; de al Hoya, Miguel; Cañadas, Carmen; Heikkinen, Tuomas; Heikkilä, Päivi; Aittomäki, Kristiina; Blanco, Ignacio; Lazaro, Conxi; Brunet, Joan; Agnarsson, Bjarni A.; Arason, Adalgeir; Barkardottir, Rosa B.; Dumont, Martine; Simard, Jacques; Montagna, Marco; Agata, Simona; D’Andrea, Emma; Yan, Max; Fox, Stephen; Rebbeck, Timothy R.; Rubinstein, Wendy; Tung, Nadine; Garber, Judy E.; Wang, Xianshu; Fredericksen, Zachary; Pankratz, Vernon S.; Lindor, Noralane M.; Szabo, Csilla; Offit, Kenneth; Sakr, Rita; Gaudet, Mia M.; Singer, Christian F.; Tea, Muy-Kheng; Rappaport, Christine; Mai, Phuong L.; Greene, Mark H.; Sokolenko, Anna; Imyanitov, Evgeny; Toland, Amanda Ewart; Senter, Leigha; Sweet, Kevin; Thomassen, Mads; Gerdes, Anne-Marie; Kruse, Torben; Caligo, Maria; Aretini, Paolo; Rantala, Johanna; von Wachenfeld, Anna; Henriksson, Karin; Steele, Linda; Neuhausen, Susan L.; Nussbaum, Bob; Beattie, Mary; Odunsi, Kunle; Sucheston, Lara; Gayther, Simon A; Nathanson, Kate; Gross, Jenny; Walsh, Christine; Karlan, Beth; Chenevix-Trench, Georgia; Easton, Douglas F.; Antoniou, Antonis C.

    2011-01-01

    Background Previous small studies found that BRCA1 and BRCA2 breast tumors differ in their pathology. Analysis of larger datasets of mutation carriers should allow further tumor characterization. Methods We used data from 4,325 BRCA1 and 2,568 BRCA2 mutation carriers to analyze the pathology of invasive breast, ovarian and contralateral breast cancers. Results There was strong evidence that the proportion of estrogen receptor (ER)-negative breast tumors decreased with age at diagnosis among BRCA1 (p-trend=1.2×10−5) but increased with age at diagnosis among BRCA2 carriers (p-trend=6.8×10−6). The proportion of triple negative tumors decreased with age at diagnosis in BRCA1 carriers but increased with age at diagnosis of BRCA2 carriers. In both BRCA1 and BRCA2 carriers, ER-negative tumors were of higher histological grade than ER-positive tumors (Grade 3 vs. Grade 1, p=1.2×10−13 for BRCA1 and p=0.001 for BRCA2). ER and progesterone receptor (PR) expression were independently associated with mutation carrier status (ER-positive odds ratio (OR) for BRCA2=9.4, 95%CI:7.0-12.6 and PR-positive OR=1.7, 95%CI:1.3-2.3, under joint analysis). Lobular tumors were more likely to be BRCA2-related (OR for BRCA2=3.3, 95%CI:2.4-4.4, p=4.4×10−14), and medullary tumors BRCA1-related (OR for BRCA2=0.25, 95%CI:0.18-0.35, p=2.3×10−15). ER-status of the first breast cancer was predictive of ER-status of asynchronous contralateral breast cancer (p=0.0004 for BRCA1; p=0.002 for BRCA2). There were no significant differences in ovarian cancer morphology between BRCA1 and BRCA2 carriers (serous:67%; mucinous:1%; endometriod:12%; clear-cell:2%). Conclusions/Impact Pathology characteristics of BRCA1 and BRCA2 tumors may be useful for improving risk prediction algorithms and informing clinical strategies for screening and prophylaxis. PMID:22144499

  6. Large Genomic Rearrangements of BRCA1 and BRCA2 among Patients Referred for Genetic Analysis in Galicia (NW Spain): Delimitation and Mechanism of Three Novel BRCA1 Rearrangements

    OpenAIRE

    Fachal, Laura; Blanco, Ana; Santamariña, Marta; Carracedo, Angel; Vega, Ana

    2014-01-01

    In the Iberian Peninsula, which includes mainly Spain and Portugal, large genomic rearrangements (LGRs) of BRCA1 and BRCA2 have respectively been found in up to 2.33% and 8.4% of families with hereditary breast and/or ovarian cancer (HBOC) that lack point mutations and small indels. In Galicia (Northwest Spain), the spectrum and frequency of BRCA1/BRCA2 point mutations differs from the rest of the Iberian populations. However, to date there are no Galician frequency reports of BRCA1/BRCA2 LGR...

  7. An entire exon 3 germ-line rearrangement in the BRCA2 gene: pathogenic relevance of exon 3 deletion in breast cancer predisposition

    Directory of Open Access Journals (Sweden)

    Demange Liliane

    2011-09-01

    Full Text Available Abstract Background Germ-line mutations in the BRCA1 and BRCA2 genes are major contributors to hereditary breast/ovarian cancer. Large rearrangements are less frequent in the BRCA2 gene than in BRCA1. We report, here, the first total deletion of exon 3 in the BRCA2 gene that was detected during screening of 2058 index cases from breast/ovarian cancer families for BRCA2 large rearrangements. Deletion of exon 3, which is in phase, does not alter the reading frame. Low levels of alternative transcripts lacking exon 3 (Δ3 delta3 transcript have been reported in normal tissues, which raises the question whether deletion of exon 3 is pathogenic. Methods Large BRCA2 rearrangements were analysed by QMPSF (Quantitative Multiplex PCR of Short Fluorescent Fragments or MLPA (Multiplex Ligation-Dependent Probe Amplification. The exon 3 deletion was characterized with a "zoom-in" dedicated CGH array to the BRCA2 gene and sequencing. To determine the effect of exon 3 deletion and assess its pathogenic effect, three methods of transcript quantification were used: fragment analysis of FAM-labelled PCR products, specific allelic expression using an intron 2 polymorphism and competitive quantitative RT-PCR. Results Large rearrangements of BRCA2 were detected in six index cases out of 2058 tested (3% of all deleterious BRCA2 mutations. This study reports the first large rearrangement of the BRCA2 gene that includes all of exon 3 and leads to an in frame deletion of exon 3 at the transcriptional level. Thirty five variants in exon 3 and junction regions of BRCA2 are also reported, that contribute to the interpretation of the pathogenicity of the deletion. The quantitative approaches showed that there are three classes of delta3 BRCA2 transcripts (low, moderate and exclusive. Exclusive expression of the delta3 transcript by the mutant allele and segregation data provide evidence for a causal effect of the exon 3 deletion. Conclusion This paper highlights that large

  8. Evaluation of two different models to predict BRCA1 and BRCA2 mutations in a cohort of Danish hereditary breast and/or ovarian cancer families

    DEFF Research Database (Denmark)

    Gerdes, Anne-Marie; Cruger, D G; Thomassen, M; Kruse, T A

    2006-01-01

    To meet the increasing demand for BRCA1 and BRCA2 mutation analysis, a robust system for selecting families who have a higher chance of a mutation has become important. Several models have been developed to help predict which samples are more likely to be mutation positive than others. We have...... undertaken a complete BRCA1 and BRCA2 mutation analysis in 267 Danish families with high-risk family history. We found deleterious mutations in 28% (76) of the families, 68% (52) of those in BRCA1 and 32% (24) in BRCA2. We compared our results with two popular manual models developed to estimate the chance...

  9. Classifications within molecular subtypes enables identification of BRCA1/BRCA2 mutation carriers by RNA tumor profiling

    DEFF Research Database (Denmark)

    Larsen, Martin J; Kruse, Torben A; Tan, Qihua;

    2013-01-01

    Pathogenic germline mutations in BRCA1 or BRCA2 are detected in less than one third of families with a strong history of breast cancer. It is therefore expected that mutations still remain undetected by currently used screening methods. In addition, a growing number of BRCA1/2 sequence variants of...... unclear pathogen significance are found in the families, constituting an increasing clinical challenge. New methods are therefore needed to improve the detection rate and aid the interpretation of the clinically uncertain variants. In this study we analyzed a series of 33 BRCA1, 22 BRCA2, and 128 sporadic......-specific BRCA1/2 gene signatures were successfully validated in two independent data sets with high accuracies. Although additional validation studies are required, indication of BRCA1/2 involvement ("BRCAness") by RNA profiling could potentially be valuable as a tool for distinguishing pathogenic mutations...

  10. [Gynecological Care and Prevention of Gynecological Malignancies in BRCA1 and BRCA2 Mutation Carriers].

    Science.gov (United States)

    Zikán, M

    2016-01-01

    This paper summarizes the current knowledge of gynecological care aspects in women with inherited predisposition to breast and ovarian cancer, i.e. BRCA1 and BRCA2 mutation carriers, and proposes guidelines for furher management of these women, addressing follow-up recommendations, prophylactic surgery indications and preimplantation genetic conseling. It evaluates cancer risk and severity of ovarian cancer in particular with regards to its high mortality resulting from aggressive biological behavior of the tumor and late detection rates. BRCA-positive women should be enrolled in prevention programs including carefull surveillance, prophylactic surgery or pre-implantation genetic counseling. Follow-up care consists of gynecological examination, expert oncogynecological ultrasound and tumor marker CA125 examination every six months. However, the most effective strategy for mortality reduction in ovarian cancer is prophylactic surgery--salpingo-oophorectomy (and hysterectomy). The optimal age for surgery is between 35 to 40 years. Prophylactic salpingo-oophorectomy performed in premenopausal women was proved to reduce the risk of ovarian as well as breast cancer. Symptoms of estrogen deficiency after prophylactic surgery can be suppressed by administration of hormone replacement therapy without increasing the risk of breast cancer. Preimplantation genetic diagnosis is an effective way to prevent the trans--mission of hereditary predisposition to the next generation. The management of patients with hereditary suspceptibility to ovarian cancer should be confined to specialized centres. PMID:26691939

  11. Targeting BRCA1 and BRCA2 Deficiencies with G-Quadruplex-Interacting Compounds.

    Science.gov (United States)

    Zimmer, Jutta; Tacconi, Eliana M C; Folio, Cecilia; Badie, Sophie; Porru, Manuela; Klare, Kerstin; Tumiati, Manuela; Markkanen, Enni; Halder, Swagata; Ryan, Anderson; Jackson, Stephen P; Ramadan, Kristijan; Kuznetsov, Sergey G; Biroccio, Annamaria; Sale, Julian E; Tarsounas, Madalena

    2016-02-01

    G-quadruplex (G4)-forming genomic sequences, including telomeres, represent natural replication fork barriers. Stalled replication forks can be stabilized and restarted by homologous recombination (HR), which also repairs DNA double-strand breaks (DSBs) arising at collapsed forks. We have previously shown that HR facilitates telomere replication. Here, we demonstrate that the replication efficiency of guanine-rich (G-rich) telomeric repeats is decreased significantly in cells lacking HR. Treatment with the G4-stabilizing compound pyridostatin (PDS) increases telomere fragility in BRCA2-deficient cells, suggesting that G4 formation drives telomere instability. Remarkably, PDS reduces proliferation of HR-defective cells by inducing DSB accumulation, checkpoint activation, and deregulated G2/M progression and by enhancing the replication defect intrinsic to HR deficiency. PDS toxicity extends to HR-defective cells that have acquired olaparib resistance through loss of 53BP1 or REV7. Altogether, these results highlight the therapeutic potential of G4-stabilizing drugs to selectively eliminate HR-compromised cells and tumors, including those resistant to PARP inhibition. PMID:26748828

  12. Breast tumor characteristics of BRCA1 and BRCA2 gene mutation carriers on MRI

    Energy Technology Data Exchange (ETDEWEB)

    Veltman, J.; Mann, R.; Blickman, J.G.; Boetes, C. [University Medical Center, 430 Department of Radiology, P.O. Box 9101, Nijmegen (Netherlands); Kok, T. [University Medical Center, Department of Radiology, Groningen (Netherlands); Obdeijn, I.M. [Erasmus Medical Center Daniel den Hoed Cancer Center, Department of Radiology, Rotterdam (Netherlands); Hoogerbrugge, N. [University Medical Center, Department of Human Genetics, Nijmegen (Netherlands)

    2008-05-15

    The appearance of malignant lesions in BRCA1 and BRCA2 mutation carriers (BRCA-MCs) on mammography and magnetic resonance imaging (MRI) was evaluated. Thus, 29 BRCA-MCs with breast cancer were retrospectively evaluated and the results compared with an age, tumor size and tumor type matched control group of 29 sporadic breast cancer cases. Detection rates on both modalities were evaluated. Tumors were analyzed on morphology, density (mammography), enhancement pattern and kinetics (MRI). Overall detection was significantly better with MRI than with mammography (55/58 vs 44/57, P = 0.021). On mammography, lesions in the BRCA-MC group were significantly more described as rounded (12//19 vs 3/13, P = 0.036) and with sharp margins (9/19 vs 1/13, P = 0.024). On MRI lesions in the BRCA-MC group were significantly more described as rounded (16/27 vs 7/28, P = 0.010), with sharp margins (20/27 vs 7/28, P < 0.001) and with rim enhancement (7/27 vs 1/28, P = 0.025). No significant difference was found for enhancement kinetics (P = 0.667). Malignant lesions in BRCA-MC frequently have morphological characteristics commonly seen in benign lesions, like a rounded shape or sharp margins. This applies for both mammography and MRI. However the possibility of MRI to evaluate the enhancement pattern and kinetics enables the detection of characteristics suggestive for a malignancy. (orig.)

  13. Breast tumor characteristics of BRCA1 and BRCA2 gene mutation carriers on MRI

    International Nuclear Information System (INIS)

    The appearance of malignant lesions in BRCA1 and BRCA2 mutation carriers (BRCA-MCs) on mammography and magnetic resonance imaging (MRI) was evaluated. Thus, 29 BRCA-MCs with breast cancer were retrospectively evaluated and the results compared with an age, tumor size and tumor type matched control group of 29 sporadic breast cancer cases. Detection rates on both modalities were evaluated. Tumors were analyzed on morphology, density (mammography), enhancement pattern and kinetics (MRI). Overall detection was significantly better with MRI than with mammography (55/58 vs 44/57, P = 0.021). On mammography, lesions in the BRCA-MC group were significantly more described as rounded (12//19 vs 3/13, P = 0.036) and with sharp margins (9/19 vs 1/13, P 0.024). On MRI lesions in the BRCA-MC group were significantly more described as rounded (16/27 vs 7/28, P = 0.010), with sharp margins (20/27 vs 7/28, P < 0.001) and with rim enhancement (7/27 vs 1/28, P = 0.025). No significant difference was found for enhancement kinetics (P = 0.667). Malignant lesions in BRCA-MC frequently have morphological characteristics commonly seen in benign lesions, like a rounded shape or sharp margins. This applies for both mammography and MRI. However the possibility of MRI to evaluate the enhancement pattern and kinetics enables the detection of characteristics suggestive for a malignancy. (orig.)

  14. An international survey of surveillance schemes for unaffected BRCA1 and BRCA2 mutation carriers.

    Science.gov (United States)

    Madorsky-Feldman, Dana; Sklair-Levy, Miri; Perri, Tamar; Laitman, Yael; Paluch-Shimon, Shani; Schmutzler, Rita; Rhiem, Kerstin; Lester, Jenny; Karlan, Beth Y; Singer, Christian F; Van Maerken, Tom; Claes, Kathleen; Brunet, Joan; Izquierdo, Angel; Teulé, Alex; Lee, Jong Won; Kim, Sung-Won; Arun, Banu; Jakubowska, Anna; Lubinski, Jan; Tucker, Katherine; Poplawski, Nicola K; Varesco, Liliana; Bonelli, Luigina Ada; Buys, Saundra S; Mitchell, Gillian; Tischkowitz, Marc; Gerdes, Anne-Marie; Seynaeve, Caroline; Robson, Mark; Kwong, Ava; Tung, Nadine; Tessa, Nalven; Domchek, Susan M; Godwin, Andrew K; Rantala, Johanna; Arver, Brita; Friedman, Eitan

    2016-06-01

    Female BRCA1/BRCA2 mutation carriers are at substantially increased risk for developing breast and/or ovarian cancer, and are offered enhanced surveillance including screening from a young age and risk-reducing surgery (RRS)-mastectomy (RRM) and/or salpingo-oophorectomy (RRSO). While there are established guidelines for early detection of breast cancer in high-risk women who have not undergone RRM, there are less developed guidelines after RRM. We evaluated the schemes offered before and after RRS in internationally diverse high-risk clinics. An e-mailed survey was distributed to high-risk clinics affiliated with CIMBA. Overall, 22 centers from 16 countries responded. Pre RRS surveillance schemes overwhelmingly included breast imaging (primarily MRI) from 18 to 30 years and clinical breast exam (CBE) at 6-12 month intervals. For ovarian cancer, all but 6 centers offered semiannual/annual gynecological exam, transvaginal ultrasound, and CA 125 measurements. Post RRM, most centers offered only annual CBE while 4 centers offered annual MRI, primarily for substantial residual breast tissue. After RRSO only 4 centers offered specific gynecological surveillance. Existing guidelines for breast/ovarian cancer detection in BRCA carriers are being applied pre RRS but are not globally harmonized, and most centers offer no specific surveillance post RRS. From this comprehensive multinational study it is clear that evidence-based, long-term prospective data on the most effective scheme for BRCA carriers post RRS is needed. PMID:27117159

  15. Two different BRCA2 mutations found in a multigenerational family with a history of breast, prostate, and lung cancers

    OpenAIRE

    Caporale DA; Swenson EE

    2014-01-01

    Diane A Caporale, Erica E SwensonDepartment of Biology, University of Wisconsin – Stevens Point, Stevens Point, WI, USAAbstract: Breast and lung cancer are two of the most common malignancies in the United States, causing approximately 40,000 and 160,000 deaths each year, respectively. Over 80% of hereditary breast cancer cases are due to mutations in two breast cancer predisposition genes, BRCA1 and BRCA2. These are tumor-suppressor genes associated with DNA repair. Since the discovery...

  16. Two different BRCA2 mutations found in a multigenerational family with a history of breast, prostate, and lung cancers

    OpenAIRE

    Caporale, Diane

    2014-01-01

    Diane A Caporale, Erica E SwensonDepartment of Biology, University of Wisconsin – Stevens Point, Stevens Point, WI, USAAbstract: Breast and lung cancer are two of the most common malignancies in the United States, causing approximately 40,000 and 160,000 deaths each year, respectively. Over 80% of hereditary breast cancer cases are due to mutations in two breast cancer predisposition genes, BRCA1 and BRCA2. These are tumor-suppressor genes associated with DNA repair. Since the disco...

  17. Anti-Müllerian hormone serum concentrations of women with germline BRCA1 or BRCA2 mutations

    Science.gov (United States)

    Phillips, Kelly-Anne; Collins, Ian M.; Milne, Roger L.; McLachlan, Sue Anne; Friedlander, Michael; Hickey, Martha; Stern, Catharyn; Hopper, John L.; Fisher, Richard; Kannemeyer, Gordon; Picken, Sandra; Smith, Charmaine D.; Kelsey, Thomas W.; Anderson, Richard A.

    2016-01-01

    STUDY QUESTION Do women with BRCA1 or BRCA2 mutations have reduced ovarian reserve, as measured by circulating anti-Müllerian hormone (AMH) concentration? SUMMARY ANSWER Women with a germline mutation in BRCA1 have reduced ovarian reserve as measured by AMH. WHAT IS KNOWN ALREADY The DNA repair enzymes encoded by BRCA1 and BRCA2 are implicated in reproductive aging. Circulating AMH is a biomarker of ovarian reserve and hence reproductive lifespan. STUDY DESIGN, SIZE, DURATION This was a cross-sectional study of AMH concentrations of 693 women at the time of enrolment into the Kathleen Cuningham Foundation Consortium for research in the Familial Breast Cancer (kConFab) cohort study (recruitment from 19 August 1997 until 18 September 2012). AMH was measured on stored plasma samples between November 2014 and January 2015 using an electrochemiluminescence immunoassay platform. PARTICIPANTS/MATERIALS, SETTING, METHODS Eligible women were from families segregating BRCA1 or BRCA2 mutations and had known mutation status. Participants were aged 25–45 years, had no personal history of cancer, retained both ovaries and were not pregnant or breastfeeding at the time of plasma storage. Circulating AMH was measured for 172 carriers and 216 non-carriers from families carrying BRCA1 mutations, and 147 carriers and 158 non-carriers from families carrying BRCA2 mutations. Associations between plasma AMH concentration and carrier status were tested by linear regression, adjusted for age at plasma storage, oral contraceptive use, body mass index and cigarette smoking. MAIN RESULTS AND THE ROLE OF CHANCE Mean AMH concentration was negatively associated with age (P IVF outside the submitted work. The remaining authors have nothing to declare and no conflicts of interest. PMID:27094481

  18. Novel mutations in the BRCA1 and BRCA2 genes in Iranian women with early-onset breast cancer

    International Nuclear Information System (INIS)

    Breast cancer is the most common female malignancy and a major cause of death in middle-aged women. So far, germline mutations in the BRCA1 and BRCA2 genes in patients with early-onset breast and/or ovarian cancer have not been identified within the Iranian population. With the collaboration of two main centres for cancer in Iran, we obtained clinical information, family history and peripheral blood from 83 women under the age of 45 with early-onset breast cancer for scanning of germline mutations in the BRCA1 and BRCA2 genes. We analysed BRCA1 exons 11 and BRCA2 exons 10 and 11 by the protein truncation test, and BRCA1 exons 2, 3, 5, 13 and 20 and BRCA2 exons 9, 17, 18 and 23 with the single-strand conformation polymorphism assay on genomic DNA amplified by polymerase chain reaction. Ten sequence variants were identified: five frameshifts (putative mutations – four novel); three missense changes of unknown significance and two polymorphisms, one seen commonly in both Iranian and British populations. Identification of these novel mutations suggests that any given population should develop a mutation database for its programme of breast cancer screening. The pattern of mutations seen in the BRCA genes seems not to differ from other populations studied. Early-onset breast cancer (less than 45 years) and a limited family history is sufficient to justify mutation screening with a detection rate of over 25% in this group, whereas sporadic early-onset breast cancer (detection rate less than 5%) is unlikely to be cost-effective

  19. VEGFR3 Inhibition Chemosensitizes Ovarian Cancer Stemlike Cells through Down-Regulation of BRCA1 and BRCA2

    OpenAIRE

    Jaeyoung Lim; Kun Yang; Barbie Taylor-Harding; W. Ruprecht Wiedemeyer; Buckanovich, Ronald J.

    2014-01-01

    In ovarian cancer, loss of BRCA gene expression in tumors is associated with improved response to chemotherapy and increased survival. A means to pharmacologically downregulate BRCA gene expression could improve the outcomes of patients with BRCA wild-type tumors. We report that vascular endothelial growth factor receptor 3 (VEGFR3) inhibition in ovarian cancer cells is associated with decreased levels of both BRCA1 and BRCA2. Inhibition of VEGFR3 in ovarian tumor cells was associated with gr...

  20. Common genetic variation at BARD1 is not associated with breast cancer risk in BRCA1 or BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Spurdle, Amanda B; Marquart, Louise; McGuffog, Lesley;

    2011-01-01

    Inherited BRCA1 and BRCA2 (BRCA1/2) mutations confer elevated breast cancer risk. Knowledge of factors that can improve breast cancer risk assessment in BRCA1/2 mutation carriers may improve personalized cancer prevention strategies....

  1. Common breast cancer-predisposition alleles are associated with breast cancer risk in BRCA1 and BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Antoniou, Antonis C; Spurdle, Amanda B; Sinilnikova, Olga M;

    2008-01-01

    Germline mutations in BRCA1 and BRCA2 confer high risks of breast cancer. However, evidence suggests that these risks are modified by other genetic or environmental factors that cluster in families. A recent genome-wide association study has shown that common alleles at single nucleotide...... polymorphisms (SNPs) in FGFR2 (rs2981582), TNRC9 (rs3803662), and MAP3K1 (rs889312) are associated with increased breast cancer risks in the general population. To investigate whether these loci are also associated with breast cancer risk in BRCA1 and BRCA2 mutation carriers, we genotyped these SNPs in a sample...... of 10,358 mutation carriers from 23 studies. The minor alleles of SNP rs2981582 and rs889312 were each associated with increased breast cancer risk in BRCA2 mutation carriers (per-allele hazard ratio [HR] = 1.32, 95% CI: 1.20-1.45, p(trend) = 1.7 x 10(-8) and HR = 1.12, 95% CI: 1.02-1.24, p(trend) = 0...

  2. No evidence of increased breast cancer risk for proven noncarriers from BRCA1 and BRCA2 families

    DEFF Research Database (Denmark)

    Nielsen, Henriette Roed; Petersen, Janne; Krogh, Lotte; Nilbert, Mef; Skytte, Anne-Bine

    2016-01-01

    In families screened for mutations in the BRCA1 or BRCA2 genes and found to have a segregating mutation the breast cancer risk for women shown not to carry the family-specific mutation might be at above "average" risk. We assessed the risk of breast cancer in a clinic based cohort of 725 female...... proven noncarriers in 239 BRCA1 and BRCA2 families compared with birth-matched controls from the Danish Civil Registration System. Prospective analysis showed no significantly increased risk for breast cancer in noncarriers with a hazard ratio of 0.67 [95 % confidence interval (CI) 0.32-1.42, p = 0.......29] for all family members who tested negative and 0.87 (95 % CI 0.38-1.97, p = 0.73) for non-carries who were first-degree relatives of mutation carriers. Proven noncarriers from BRCA1 and BRCA2 families have no markedly increased risk for breast cancer compared to the general population, and our data do...

  3. Effect of Prior Bilateral Oophorectomy on the Presentation of Breast Cancer in BRCA1 and BRCA2 Mutation Carriers

    Directory of Open Access Journals (Sweden)

    Metcalfe Kelly A

    2005-04-01

    Full Text Available Abstract Purpose To compare the presentation of invasive breast cancer in BRCA1 and BRCA2 mutation carriers with and without prior bilateral oophorectomy. Patients and methods Women with a BRCA1 or BRCA2 mutation with the diagnosis of invasive breast cancer were identified from ten cancer genetics clinics. The medical history, medical treatment records and pathology reports for the breast cancers were reviewed. Information was abstracted from medical charts, including history (and date of oophorectomy, date of breast cancer diagnosis, stage of disease, and pathologic characteristics of the breast cancer. Women with prior bilateral oophorectomy were matched by age, year of diagnosis, and mutation with one or more women who had two intact ovaries at the time of breast cancer diagnosis. Characteristics of the breast tumours were compared between the two groups. Results Women with prior bilateral oophorectomy presented with smaller tumours on average compared to women without prior oophorectomy (mean size 1.50 cm vs. 1.95 cm; p = 0.01. Additionally, although not statistically significant, women with intact ovaries were more likely to have high-grade tumour (70% vs. 54%: p = 0.10 and to have positive lymph nodes (34% vs. 18%; p = 0.11 compared to women with prior bilateral oophorectomy. Conclusions Bilateral oophorectomy prior to breast cancer appears to favourably influence the biological presentation of breast cancer in BRCA1 and BRCA2 mutation carriers.

  4. An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers

    OpenAIRE

    Blein, Sophie; Bardel, Claire; Danjean, Vincent; McGuffog, Lesley; Healey, Sue; Barrowdale, Daniel; Lee, Andrew; Dennis, Joe; Kuchenbaecker, Karoline B.; Soucy, Penny; Terry, Mary Beth; Chung, Wendy K.; Goldgar, David E; Buys, Saundra S.; Janavicius, Ramunas

    2015-01-01

    Introduction: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their meta...

  5. An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers

    OpenAIRE

    Blein, Sophie; Bardel, Claire; Danjean, Vincent; McGuffog, Lesley; Healey, Sue; Barrowdale, Daniel; Lee, Andrew; Dennis, Joe; Kuchenbaecker, Karoline B.; Soucy, Penny; Terry, Mary Beth; Chung, Wendy K.; Goldgar, David E; Buys, Saundra S.; Janavicius, Ramunas

    2015-01-01

    Introduction Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metab...

  6. An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers

    OpenAIRE

    Blein, Sophie; Bardel, Claire; Danjean, Vincent; McGuffog, Lesley; Healey, Sue; Barrowdale, Daniel; Lee, Andrew; Dennis, Joe; Kuchenbaecker, Karoline B.; Soucy, Penny; Terry, Mary Beth; Chung, Wendy K.; Goldgar, David E; Buys, Saundra S.; Janavicius, Ramunas

    2015-01-01

    INTRODUCTION: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their meta...

  7. A prospective investigation of predictive and modifiable risk factors for breast cancer in unaffected BRCA1 and BRCA2 gene carriers

    OpenAIRE

    O'Sullivan, Jacintha

    2013-01-01

    Background Breast cancer is the most common female cancer worldwide. The lifetime risk of a woman being diagnosed with breast cancer is approximately 12.5%. For women who carry the deleterious mutation in either of the BRCA genes, BRCA1 or BRCA2, the risk of developing breast or ovarian cancer is significantly increased. In recent years there has been increased penetrance of BRCA1 and BRCA2 associated breast cancer, prompting investigation into the role of modifiable risk factors in this ...

  8. Detection of BRCA1 and BRCA2 gene mutation in Egyptian females with breast cancer and their relatives by PCR-SSCP method.

    Science.gov (United States)

    Fattouh, Mona; Ahmed, Hydi; Hafez, Elsayed El-Sayed

    2011-01-01

    Germline mutations in the BRCA1 or BRCA2 genes predispose their carriers to breast or/and ovarian cancers during their lifetime. This study was performed to identify germline mutations in BRCA1 and BRCA2 genes for the early detection of pre-symptomatic mutation carriers in Egyptian healthy females who were first-degree relatives of affected women from families with and without family history of breast cancer. Sixty-two patients (index cases) with invasive breast cancer belonging to sixty families and their asymptomatic female first-degree relatives (300 cases) were studied for germline mutations of BRCA1 and BRCA2 genes. Five mutations were detected in 52 families (86.7%) with inherited mutations in either BRCA1 or BRCA2. Sixty percent of these families had BRCA1 mutation and 26.7% had BRCA2 mutations. They were identified by using the combination of SSCP and heteroduplex analysis. All but one of the mutations were detected within the BRCA1 gene in addition to one mutation in the BRCA2 gene. PMID:23082475

  9. Ovarian Cancer Susceptibility Alleles and Risk of Ovarian Cancer in BRCA1 and BRCA2 Mutation Carriers

    Science.gov (United States)

    Ramus, Susan J.; Antoniou, Antonis C; Kuchenbaecker, Karoline B.; Soucy, Penny; Beesley, Jonathan; Chen, Xiaoqing; McGuffog, Lesley; Sinilnikova, Olga M.; Healey, Sue; Barrowdale, Daniel; Lee, Andrew; Thomassen, Mads; Gerdes, Anne-Marie; Kruse, Torben A.; Jensen, Uffe Birk; Skytte, Anne-Bine; Caligo, Maria A.; Liljegren, Annelie; Lindblom, Annika; Olsson, Håkan; Kristoffersson, Ulf; Stenmark-Askmalm, Marie; Melin, Beatrice; Domchek, Susan M.; Nathanson, Katherine L.; Rebbeck, Timothy R.; Jakubowska, Anna; Lubinski, Jan; Jaworska, Katarzyna; Durda, Katarzyna; Złowocka, Elżbieta; Gronwald, Jacek; Huzarski, Tomasz; Byrski, Tomasz; Cybulski, Cezary; Toloczko-Grabarek, Aleksandra; Osorio, Ana; Benitez, Javier; Duran, Mercedes; Tejada, Maria-Isabel; Hamann, Ute; Rookus, Matti; van Leeuwen, Flora E.; Aalfs, Cora M.; Meijers-Heijboer, Hanne E.J.; van Asperen, Christi J.; van Roozendaal, K.E.P.; Hoogerbrugge, Nicoline; Collée, J. Margriet; Kriege, Mieke; van der Luijt, Rob B.; Peock, Susan; Frost, Debra; Ellis, Steve D.; Platte, Radka; Fineberg, Elena; Evans, D. Gareth; Lalloo, Fiona; Jacobs, Chris; Eeles, Ros; Adlard, Julian; Davidson, Rosemarie; Eccles, Diana; Cole, Trevor; Cook, Jackie; Paterson, Joan; Douglas, Fiona; Brewer, Carole; Hodgson, Shirley; Morrison, Patrick J.; Walker, Lisa; Porteous, Mary E.; Kennedy, M. John; Pathak, Harsh; Godwin, Andrew K.; Stoppa-Lyonnet, Dominique; Caux-Moncoutier, Virginie; de Pauw, Antoine; Gauthier-Villars, Marion; Mazoyer, Sylvie; Léoné, Mélanie; Calender, Alain; Lasset, Christine; Bonadona, Valérie; Hardouin, Agnès; Berthet, Pascaline; Bignon, Yves-Jean; Uhrhammer, Nancy; Faivre, Laurence; Loustalot, Catherine; Buys, Saundra; Daly, Mary; Miron, Alex; Terry, Mary Beth; Chung, Wendy K.; John, Esther M; Southey, Melissa; Goldgar, David; Singer, Christian F; Tea, Muy-Kheng; Pfeiler, Georg; Fink-Retter, Anneliese; Hansen, Thomas v. O.; Ejlertsen, Bent; Johannsson, Oskar Th.; Offit, Kenneth; Kirchhoff, Tomas; Gaudet, Mia M.; Vijai, Joseph; Robson, Mark; Piedmonte, Marion; Phillips, Kelly-Anne; Van Le, Linda; Hoffman, James S; Toland, Amanda Ewart; Montagna, Marco; Tognazzo, Silvia; Imyanitov, Evgeny; Isaacs, Claudine; Janavicius, Ramunas; Lazaro, Conxi; Blanco, Ignacio; Tornero, Eva; Navarro, Matilde; Moysich, Kirsten B.; Karlan, Beth Y.; Gross, Jenny; Olah, Edith; Vaszko, Tibor; Teo, Soo-Hwang; Ganz, Patricia A.; Beattie, Mary S.; Dorfling, Cecelia M; van Rensburg, Elizabeth J; Diez, Orland; Kwong, Ava; Schmutzler, Rita K.; Wappenschmidt, Barbara; Engel, Christoph; Meindl, Alfons; Ditsch, Nina; Arnold, Norbert; Heidemann, Simone; Niederacher, Dieter; Preisler-Adams, Sabine; Gadzicki, Dorotehea; Varon-Mateeva, Raymonda; Deissler, Helmut; Gehrig, Andrea; Sutter, Christian; Kast, Karin; Fiebig, Britta; Schäfer, Dieter; Caldes, Trinidad; de la Hoya, Miguel; Nevanlinna, Heli; Aittomäki, Kristiina; Plante, Marie; Spurdle, Amanda B.; Neuhausen, Susan L.; Ding, Yuan Chun; Wang, Xianshu; Lindor, Noralane; Fredericksen, Zachary; Pankratz, V. Shane; Peterlongo, Paolo; Manoukian, Siranoush; Peissel, Bernard; Zaffaroni, Daniela; Bonanni, Bernardo; Bernard, Loris; Dolcetti, Riccardo; Papi, Laura; Ottini, Laura; Radice, Paolo; Greene, Mark H.; Mai, Phuong L.; Andrulis, Irene L.; Glendon, Gord; Ozcelik, Hilmi; Pharoah, Paul D.P.; Gayther, Simon A.; Simard, Jacques; Easton, Douglas F.; Couch, Fergus J.; Chenevix-Trench, Georgia

    2012-01-01

    Germline mutations in BRCA1 and BRCA2 are associated with increased risks of breast and ovarian cancer. A genome-wide association study (GWAS) identified six alleles associated with risk of ovarian cancer for women in the general population. We evaluated four of these loci as potential modifiers of ovarian cancer risk for BRCA1 and BRCA2 mutation carriers. Four single-nucleotide polymorphisms (SNPs), rs10088218 (at 8q24), rs2665390 (at 3q25), rs717852 (at 2q31), and rs9303542 (at 17q21), were genotyped in 12,599 BRCA1 and 7,132 BRCA2 carriers, including 2,678 ovarian cancer cases. Associations were evaluated within a retrospective cohort approach. All four loci were associated with ovarian cancer risk in BRCA2 carriers; rs10088218 per-allele hazard ratio (HR) = 0.81 (95% CI: 0.67–0.98) P-trend = 0.033, rs2665390 HR = 1.48 (95% CI: 1.21–1.83) P-trend = 1.8 × 10−4, rs717852 HR = 1.25 (95% CI: 1.10–1.42) P-trend = 6.6 × 10−4, rs9303542 HR = 1.16 (95% CI: 1.02–1.33) P-trend = 0.026. Two loci were associated with ovarian cancer risk in BRCA1 carriers; rs10088218 per-allele HR = 0.89 (95% CI: 0.81–0.99) P-trend = 0.029, rs2665390 HR = 1.25 (95% CI: 1.10–1.42) P-trend = 6.1 × 10−4. The HR estimates for the remaining loci were consistent with odds ratio estimates for the general population. The identification of multiple loci modifying ovarian cancer risk may be useful for counseling women with BRCA1 and BRCA2 mutations regarding their risk of ovarian cancer. PMID:22253144

  10. Recommendations for prevention in carriers of BRCA1 and BRCA2 mutations

    International Nuclear Information System (INIS)

    It is estimated that 5% -10% of all breast cancers in women are developed in the context of inherited susceptibility of dominant autosomal, where the BRCA1 and BRCA2 are the main known associated genes. The inheritance of a mutated allele of some of these genes confers a risk extremely high in the breast cancer. In fact, while in the general population in countries with high incidence of breast cancer such as Uruguay, the cumulative risk of developing the disease is around 10% -12%, in the carriers of a germ line mutation in BRCA1 / 2 such risk can reach 85%. Furthermore, they present an increased risk of developing other tumors, including ovarian cancer. The recommendations for monitoring / screening are based on expert opinion. In relation to breast cancer, the emphasis is on the early onset controls than the general population, which is based on the younger age presentation of the disease in genetically predisposed women. Recommendations for ovarian cancer consists of trans vaginal ultrasound and determination of serum levels of CA125 from 30-35 years. The suboptimal results obtained with the conventional monitoring methods emphasize the importance of incorporating more useful procedures. In these sense preliminary results show that mammary magnetic resonance imaging has higher sensitivity. Moreover, proteomics allowed development of promising techniques to improve the early diagnosis of ovarian cancer. Primary prevention options include mastectomy and prophylactic oophorectomy and chemo prevention. Difficulties in early detection of ovarian cancer and its high mortality justify consider prophylactic oophorectomy as a management option from 35 years and once completed the family. In the case of breast cancer, if while prophylactic mastectomy has proven very effective, is unacceptable for most patients. Monitoring to detect early and chemo prevention are important alternatives. In all cases, the management should be individualized based on the level of risk and

  11. Phenotypic features and genetic characterization of male breast cancer families: identification of two recurrent BRCA2 mutations in north-east of Italy

    Directory of Open Access Journals (Sweden)

    Miolo GianMaria

    2006-06-01

    Full Text Available Abstract Background Breast cancer in men is an infrequent occurrence, accounting for ~1% of all breast tumors with an incidence of about 1:100,000. The relative rarity of male breast cancer (MBC limits our understanding of the epidemiologic, genetic and clinical features of this tumor. Methods From 1997 to 2003, 10 MBC patients were referred to our Institute for genetic counselling and BRCA1/2 testing. Here we report on the genetic and phenotypic characterization of 10 families with MBC from the North East of Italy. In particular, we wished to assess the occurrence of specific cancer types in relatives of MBC probands in families with and without BRCA2 predisposing mutations. Moreover, families with recurrent BRCA2 mutations were also characterized by haplotype analysis using 5 BRCA2-linked dinucleotide repeat markers and 8 intragenic BRCA2 polymorphisms. Results Two pathogenic mutations in the BRCA2 gene were observed: the 9106C>T (Q2960X and the IVS16-2A>G (splicing mutations, each in 2 cases. A BRCA1 mutation of uncertain significance 4590C>G (P1491A was also observed. In families with BRCA2 mutations, female breast cancer was more frequent in the first and second-degree relatives compared to the families with wild type BRCA1/2 (31.9% vs. 8.0% p = 0.001. Reconstruction of the chromosome phasing in three families and the analysis of three isolated cases with the IVS16-2A>G BRCA2 mutation identified the same haplotype associated with MBC, supporting the possibility that this founder mutation previously detected in Slovenian families is also present in the North East of our Country. Moreover, analysis of one family with the 9106C>T BRCA2 mutation allowed the identification of common haplotypes for both microsatellite and intragenic polymorphisms segregating with the mutation. Three isolated cases with the same mutation shared the same intragenic polymorphisms and three 5' microsatellite markers, but showed a different haplotype for 3' markers

  12. Relationship Between Mutations In BRCA1 And BRCA2 Genes And Breast Cancer Prevalence Among Egyptian Women

    International Nuclear Information System (INIS)

    Breast cancer represents the most common cancer of women in the world and it is a biologically heterogeneous disease influenced by complex interactions between multiple genetic and environmental risk factors. In Egypt, breast cancer is classified as the first rank cancer case among women. The present study included 55 patients with breast cancer from Upper Egypt of which 40 patients had sporadic and 15 had familial breast cancers. Mutations in DNA of exons 10 and 11 of BRCA1 and BRCA2 were detected by single strand conformation polymorphisms (SSCPs) and sequencing. Moreover, BRCA1 protein expression was detected by immunostaining technique and correlation between risk factors and incidence rate of breast cancer. The results revealed 5 mutations (unclassified variants); three mutations (60%) were recorded internationally in Breast Information Cancer (BIC), one of them was 1767 C→T(550 Asn→His) and previously recorded in the Arabic world and the other 2 novel mutations were 1663 T→ C(479 Asp→Gly) and del AG 6079. The results obtained in the present study also demonstrated that the increase of the negative immunostaining of ''BRCA1'' protein in the tumour cells of BRCA1 mutation carriers was comparable to familial and sporadic breast cancer non-carrier. Accurate estimation of the relative frequency of BRCA1 and BRCA2 mutations in Egyptian breast cancer patients could not be deduced from the results of this relatively small pilot study. More studies with larger numbers of patients are needed to clarify the relation between BRCA1 and BRCA2 gene mutations and the prediction of breast cancer in Egypt.

  13. Histopathological features of breast tumours in BRCA1, BRCA2 and mutation-negative breast cancer families

    International Nuclear Information System (INIS)

    Histopathological features of BRCA1 and BRCA2 tumours have previously been characterised and compared with unselected breast tumours; however, familial non-BRCA1/2 tumours are less well known. The aim of this study was to characterise familial non-BRCA1/2 tumours and to evaluate routine immunohistochemical and pathological markers that could help us to further distinguish families carrying BRCA1/2 mutations from other breast cancer families. Breast cancer tissue specimens (n = 262) from 25 BRCA1, 20 BRCA2 and 74 non-BRCA1/2 families were studied on a tumour tissue microarray. Immunohistochemical staining of oestrogen receptor (ER), progesterone receptor (PgR) and p53 as well as the histology and grade of these three groups were compared with each other and with the respective information on 862 unselected control patients from the archives of the Pathology Department of Helsinki University Central Hospital. Immunohistochemical staining of erbB2 was also performed among familial cases. BRCA1-associated cancers were diagnosed younger and were more ER-negative and PgR-negative, p53-positive and of higher grade than the other tumours. However, in multivariate analysis the independent factors compared with non-BRCA1/2 tumours were age, grade and PgR negativity. BRCA2 cases did not have such distinctive features compared with non-BRCA1/2 tumours or with unselected control tumours. Familial cases without BRCA1/2 mutations had tumours of lower grade than the other groups. BRCA1 families differed from mutation-negative families by age, grade and PgR status, whereas ER status was not an independent marker

  14. Evaluation of the Needs of Male Carriers of Mutations in BRCA1 or BRCA2 Who Have Undergone Genetic Counseling

    OpenAIRE

    Liede, Alexander; Metcalfe, Kelly; Hanna, Danielle; Hoodfar, Elizabeth; Snyder, Carrie; Durham, Carolyn; Lynch, Henry T.; Narod, Steven A.

    2000-01-01

    To date, the concerns of men at risk of inheriting a BRCA1 mutation or a BRCA2 mutation have received little attention. It had been anticipated that few men would be interested in predictive testing when a BRCA mutation was identified in their family. However, these men are often affected emotionally by diagnoses of breast cancer in their relatives and may themselves harbor fears that cancer will develop. Male carriers of BRCA1/2 mutations are at increased risk of development of cancers of se...

  15. A Rapid and Reliable Test for BRCA1 and BRCA2 Founder Mutation Analysis in Paraffin Tissue Using Pyrosequencing

    OpenAIRE

    Zhang, Liying; Kirchhoff, Tomas; Yee, Cindy J; Offit, Kenneth

    2009-01-01

    The founder mutations in BRCA (BRCA1*185delAG, BRCA1*5382insC, and BRCA2*6174delT) account for 95% of the detectable BRCA mutations in breast and ovarian cancer families of Ashkenazi Jewish ancestry. Optimal clinical management of individuals from these high-risk families relies on the identification of BRCA founder mutations in the laboratory. We have therefore developed a rapid and reliable approach using pyrosequencing, which allows for the detection of these frequent frameshift mutations ...

  16. International distribution and age estimation of the Portuguese BRCA2 c.156_157insAlu founder mutation

    DEFF Research Database (Denmark)

    Peixoto, Ana; Santos, Catarina; Pinheiro, Manuela;

    2011-01-01

    total of 5,443 suspected HBOC families from several countries. Whereas the c.156_157insAlu BRCA2 mutation was detected in 11 of 149 suspected HBOC families from Portugal, representing 37.9% of all deleterious mutations, in other countries it was detected only in one proband living in France and in four...... individuals requesting predictive testing living in France and in the USA, all being Portuguese immigrants. After performing an extensive haplotype study in carrier families, we estimate that this founder mutation occurred 558 +/- 215 years ago. We further demonstrate significant quantitative differences...

  17. International distribution and age estimation of the Portuguese BRCA2 c.156_157insAlu founder mutation

    DEFF Research Database (Denmark)

    Peixoto, Ana; Santos, Catarina; Pinheiro, Manuela;

    2011-01-01

    total of 5,443 suspected HBOC families from several countries. Whereas the c.156_157insAlu BRCA2 mutation was detected in 11 of 149 suspected HBOC families from Portugal, representing 37.9% of all deleterious mutations, in other countries it was detected only in one proband living in France and in four...... individuals requesting predictive testing living in France and in the USA, all being Portuguese immigrants. After performing an extensive haplotype study in carrier families, we estimate that this founder mutation occurred 558 ± 215 years ago. We further demonstrate significant quantitative differences...

  18. Analysis of Founder Mutations in Rare Tumors Associated With Hereditary Breast/Ovarian Cancer Reveals a Novel Association of BRCA2 Mutations with Ampulla of Vater Carcinomas.

    Science.gov (United States)

    Pinto, Pedro; Peixoto, Ana; Santos, Catarina; Rocha, Patrícia; Pinto, Carla; Pinheiro, Manuela; Leça, Luís; Martins, Ana Teresa; Ferreira, Verónica; Bartosch, Carla; Teixeira, Manuel R

    2016-01-01

    BRCA1 and BRCA2 mutations are responsible for hereditary breast and ovarian cancer, but they also confer an increased risk for the development of rarer cancers associated with this syndrome, namely, cancer of the pancreas, male breast, peritoneum, and fallopian tube. The objective of this work was to quantify the contribution of the founder mutations BRCA2 c.156_157insAlu and BRCA1 c.3331_3334del for cancer etiology in unselected hospital-based cohorts of Portuguese patients diagnosed with these rarer cancers, by using a strategy that included testing of archival tumor tissue. A total of 102 male breast, 68 pancreatic and 33 peritoneal/fallopian tube carcinoma cases were included in the study. The BRCA2 c.156_157insAlu mutation was observed with a frequency of 7.8% in male breast cancers, 3.0% in peritoneal/fallopian tube cancers, and 1.6% in pancreatic cancers, with estimated total contributions of germline BRCA2 mutations of 14.3%, 5.5%, and 2.8%, respectively. No carriers of the BRCA1 c.3331_3334del mutation were identified. During our study, a patient with an ampulla of Vater carcinoma was incidentally found to carry the BRCA2 c.156_157insAlu mutation, so we decided to test a consecutive series of additional 15 ampullary carcinomas for BRCA1/BRCA2 mutations using a combination of direct founder mutation testing and full gene analysis with next generation sequencing. BRCA2 mutations were observed with a frequency of 14.3% in ampulla of Vater carcinomas. In conclusion, taking into account the implications for both the individuals and their family members, we recommend that patients with these neoplasias should be offered BRCA1/BRCA2 genetic testing and we here show that it is feasible to test for founder mutations in archival tumor tissue. Furthermore, we identified for the first time a high frequency of germline BRCA2 mutations in ampullary cancers. PMID:27532258

  19. Dealing with the tests for BRCA1 and BRCA2 screening from the clinicians point of view

    International Nuclear Information System (INIS)

    The two major hereditary breast cancer susceptibility genes, BRCA1 and BRCA2 are associated with 85 to 90% of all hereditary breast and ovarian cancers. They encode for two proteins who participate in a common DNA damage response pathway associated with the double-strand break repair. The standard of gene analysis is complete gene sequencing, although this is a very expensive and time-consuming method. Therefore, it is necessary to select families with a high a-priori risk for having a mutation. Interpretation of gene testing results may be difficult as penetrance is not hundred percent and due to unclassified variants. Prevention of breast and ovarian cancer is possible with prophylactic surgery. Alternatively, endocrine prevention or intensified surveillance could be tried. The evidence of BRCA1 and BRCA2 concerning radiosensitivity is not clear yet. The susceptibility to radiation-induced DNA damage could have implications for therapy options. As the benefits of so far used diagnostic or therapeutic tools are high, they outweigh the possible risks due to increased radiosensitivity. (orig.)

  20. Predicting the Pathogenic Potential of BRCA1 and BRCA2 Gene Variants Identified in Clinical Genetic Testing

    Directory of Open Access Journals (Sweden)

    Clare Brookes

    2015-05-01

    Full Text Available Objectives: Missense variants are very commonly detected when screening for mutations in the BRCA1 and BRCA2 genes. Pathogenic mutations in the BRCA1 and BRCA2 genes lead to an increased risk of developing breast, ovarian, prostate and/or pancreatic cancer. This study aimed to assess the predictive capability of in silico programmes and mutation databases in assisting diagnostic laboratories to determine the pathogenicity of sequence-detectable mutations. Methods: Between July 2011 and April 2013, an analysis was undertaken of 13 missense BRCA gene variants that had been detected in patients referred to the Genetic Health Services New Zealand (Northern Hub for BRCA gene analysis. The analysis involved the use of 13 in silico protein prediction programmes, two in silico transcript analysis programmes and the examination of three BRCA gene databases. Results: In most of the variants, the analysis showed different in silico interpretations. This illustrates the interpretation challenges faced by diagnostic laboratories. Conclusion: Unfortunately, when using online mutation databases and carrying out in silico analyses, there is significant discordance in the classification of some missense variants in the BRCA genes. This discordance leads to complexities in interpreting and reporting these variants in a clinical context. The authors have developed a simple procedure for analysing variants; however, those of unknown significance largely remain unknown. As a consequence, the clinical value of some reports may be negligible.

  1. BRCA1 and BRCA2 mutation prevalence and clinical characteristics of a population-based series of ovarian cancer cases from Denmark

    DEFF Research Database (Denmark)

    Soegaard, M.; Kjaer, S.K.; Cox, M.; Wozniak, E.; Hogdall, E.; Blaakaer, J.; Jacobs, I.J.; Gayther, S.A.; Ramus, S.J.; Høgdall, Claus Kim

    2008-01-01

    PURPOSE: To evaluate the prevalence of BRCA1 and BRCA2 mutations and associations with clinical correlates of disease in a population-based series of ovarian cancer cases from Denmark. METHODS: DNA sequencing and multiplex ligation-dependent probe amplification analysis were used to analyze the...... BRCA1 and BRCA2 genes for coding sequence mutations and large genomic rearrangements in 445 confirmed cases of ovarian cancer. We evaluated associations between mutation status and clinical characteristics, including cancer risks for first-degree relatives and clinicopathologic features of tumors....... RESULTS: Deleterious BRCA1 or BRCA2 mutations were identified in 26 cases; thus, mutations in these genes are responsible for at least 5.8% of ovarian cancer cases in this population. Five different mutations were identified in more than one individual, suggesting that they may be founder mutations in...

  2. Invasive breast cancer following bilateral subcutaneous mastectomy in a BRCA2 mutation carrier: a case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Galvez Maria

    2005-08-01

    Full Text Available Abstract Background Primary prevention of breast cancer through prophylactic mastectomy can reduce the risk of malignancy in high-risk individuals. No type of mastectomy completely removes all breast tissue, but a subcutaneous mastectomy leaves more tissue in situ than does a simple mastectomy. Case presentation We report a case of invasive breast cancer in a BRCA2-positive woman 33 years after bilateral subcutaneous mastectomy. To our knowledge, only one case of primary breast cancer after prophylactic mastectomy in a BRCA1-positive patient has been reported in the literature and none in BRCA2-positive individuals. Conclusion Careful documentation and long follow-up is essential to fully assess the benefits and risks of preventive surgical procedures in BRCA1 and BRCA2 mutation carriers.

  3. Sanger Sequencing for BRCA1 c.68_69del, BRCA1 c.5266dup and BRCA2 c.5946del Mutation Screen on Pap Smear Cytology Samples

    Directory of Open Access Journals (Sweden)

    Sin Hang Lee

    2016-02-01

    Full Text Available Three sets of polymerase chain reaction (PCR primers were designed for heminested PCR amplification of the target DNA fragments in the human genome which include the site of BRCA1 c.68_69del, BRCA1 c.5266dup and BRCA2 c.5946del respectively, to prepare the templates for direct Sanger sequencing screen of these three founder mutations. With a robust PCR mixture, crude proteinase K digestate of the fixed cervicovaginal cells in the liquid-based Papanicolaou (Pap cytology specimens can be used as the sample for target DNA amplification without pre-PCR DNA extraction, purification and quantitation. The post-PCR products can be used directly as the sequencing templates without further purification or quantitation. By simplifying the frontend procedures for template preparation, the cost for screening these three founder mutations can be reduced to about US $200 per test when performed in conjunction with human papillomavirus (HPV assays now routinely ordered for cervical cancer prevention. With this projected price structure, selective patients in a high-risk population can be tested and each provided with a set of DNA sequencing electropherograms to document the absence or presence of these founder mutations in her genome to help assess inherited susceptibility to breast and ovarian cancer in this era of precision molecular personalized medicine.

  4. Sanger Sequencing for BRCA1 c.68_69del, BRCA1 c.5266dup and BRCA2 c.5946del Mutation Screen on Pap Smear Cytology Samples.

    Science.gov (United States)

    Lee, Sin Hang; Zhou, Shaoxia; Zhou, Tianjun; Hong, Guofan

    2016-01-01

    Three sets of polymerase chain reaction (PCR) primers were designed for heminested PCR amplification of the target DNA fragments in the human genome which include the site of BRCA1 c.68_69del, BRCA1 c.5266dup and BRCA2 c.5946del respectively, to prepare the templates for direct Sanger sequencing screen of these three founder mutations. With a robust PCR mixture, crude proteinase K digestate of the fixed cervicovaginal cells in the liquid-based Papanicolaou (Pap) cytology specimens can be used as the sample for target DNA amplification without pre-PCR DNA extraction, purification and quantitation. The post-PCR products can be used directly as the sequencing templates without further purification or quantitation. By simplifying the frontend procedures for template preparation, the cost for screening these three founder mutations can be reduced to about US $200 per test when performed in conjunction with human papillomavirus (HPV) assays now routinely ordered for cervical cancer prevention. With this projected price structure, selective patients in a high-risk population can be tested and each provided with a set of DNA sequencing electropherograms to document the absence or presence of these founder mutations in her genome to help assess inherited susceptibility to breast and ovarian cancer in this era of precision molecular personalized medicine. PMID:26867194

  5. Design of potent inhibitors of human RAD51 recombinase based on BRC motifs of BRCA2 protein: modeling and experimental validation of a chimera peptide.

    KAUST Repository

    Nomme, Julian

    2010-08-01

    We have previously shown that a 28-amino acid peptide derived from the BRC4 motif of BRCA2 tumor suppressor inhibits selectively human RAD51 recombinase (HsRad51). With the aim of designing better inhibitors for cancer treatment, we combined an in silico docking approach with in vitro biochemical testing to construct a highly efficient chimera peptide from eight existing human BRC motifs. We built a molecular model of all BRC motifs complexed with HsRad51 based on the crystal structure of the BRC4 motif-HsRad51 complex, computed the interaction energy of each residue in each BRC motif, and selected the best amino acid residue at each binding position. This analysis enabled us to propose four amino acid substitutions in the BRC4 motif. Three of these increased the inhibitory effect in vitro, and this effect was found to be additive. We thus obtained a peptide that is about 10 times more efficient in inhibiting HsRad51-ssDNA complex formation than the original peptide.

  6. Expression of DNA Damage Response Molecules PARP1, γH2AX, BRCA1, and BRCA2 Predicts Poor Survival of Breast Carcinoma Patients

    Directory of Open Access Journals (Sweden)

    See-Hyoung Park

    2015-08-01

    Full Text Available BACKGROUND: Poly(ADP-ribose polymerase 1 (PARP1, γH2AX, BRCA1, and BRCA2 are conventional molecular indicators of DNA damage in cells and are often overexpressed in various cancers. In this study, we aimed, using immunohistochemical detection, whether the co-expression of PARP1, γH2AX, BRCA1, and BRCA2 in breast carcinoma (BCA tissue can provide more reliable prediction of survival of BCA patients. MATERIALS AND METHODS: We investigated immunohistochemical expression and prognostic significance of the expression of PARP1, γH2AX, BRCA1, and BRCA2 in 192 cases of BCAs. RESULTS: The expression of these four molecules predicted earlier distant metastatic relapse, shorter overall survival (OS, and relapse-free survival (RFS by univariate analysis. Multivariate analysis revealed the expression of PARP1, γH2AX, and BRCA2 as independent poor prognostic indicators of OS and RFS. In addition, the combined expressional pattern of BRCA1, BRCA2, PARP1, and γH2AX (CSbbph was an additional independent prognostic predictor for OS (P < .001 and RFS (P < .001. The 10-year OS rate was 95% in the CSbbph-low (CSbbph scores 0 and 1 subgroup, but that was only 35% in the CSbbph-high (CSbbph score 4 subgroup. CONCLUSION: This study has demonstrated that the individual and combined expression patterns of PARP1, γH2AX, BRCA1, and BRCA2 could be helpful in determining an accurate prognosis for BCA patients and for the selection of BCA patients who could potentially benefit from anti-PARP1 therapy with a combination of genotoxic chemotherapeutic agents.

  7. Breast and Ovarian Cancer Risk due to Prevalence of BRCA1 and BRCA2 Variants in Pakistani Population: A Pakistani Database Report

    Directory of Open Access Journals (Sweden)

    Ayesha Farooq

    2011-01-01

    Mutational screening of the exons in all the samples of our study group did not reveal any pathogenic mutation. These results along with the results of the previous Pakistani studies for both BRCA1 and BRCA2 genes were summed up to prepare a Pakistani database. Percentage involvement of these genes was estimated. Nine percent of these cancers show alterations in BRCA1 gene while 3 percent have shown BRCA2 variants. The remaining 88 percent of breast and ovarian cancers can be attributed to the involvement of other genes.

  8. Genotyping of BRCA1, BRCA2, p53, CDKN2A, MLH1 and MSH2 genes in a male patient with secondary breast cancer

    International Nuclear Information System (INIS)

    Some tumour suppressor genes (BRCA2) and mismatch repair genes (MSH2, MLH1) are correlated with an increased risk for male breast cancer. Our patient developed secondary breast cancer after the treatment for Hodgkin’s disease in childhood. DNA was isolated from the patients’ blood and screened for mutations, polymorphisms and variants in BRCA1, BRCA2, p53, CDKN2A, MLH1 and MSH2 genes. We found no mutations but common polymorphisms, and three variants in mismatch repair genes. Nucleotide variants c.2006-6T>C and p.G322D in MSH2 might be correlated with male breast cancer

  9. Common variants in LSP1, 2q35 and 8q24 and breast cancer risk for BRCA1 and BRCA2 mutation carriers

    Science.gov (United States)

    Antoniou, Antonis C.; Sinilnikova, Olga M.; McGuffog, Lesley; Healey, Sue; Nevanlinna, Heli; Heikkinen, Tuomas; Simard, Jacques; Spurdle, Amanda B.; Beesley, Jonathan; Chen, Xiaoqing; Neuhausen, Susan L.; Ding, Yuan C.; Couch, Fergus J.; Wang, Xianshu; Fredericksen, Zachary; Peterlongo, Paolo; Peissel, Bernard; Bonanni, Bernardo; Viel, Alessandra; Bernard, Loris; Radice, Paolo; Szabo, Csilla I.; Foretova, Lenka; Zikan, Michal; Claes, Kathleen; Greene, Mark H.; Mai, Phuong L.; Rennert, Gad; Lejbkowicz, Flavio; Andrulis, Irene L.; Ozcelik, Hilmi; Glendon, Gord; Gerdes, Anne-Marie; Thomassen, Mads; Sunde, Lone; Caligo, Maria A.; Laitman, Yael; Kontorovich, Tair; Cohen, Shimrit; Kaufman, Bella; Dagan, Efrat; Baruch, Ruth Gershoni; Friedman, Eitan; Harbst, Katja; Barbany-Bustinza, Gisela; Rantala, Johanna; Ehrencrona, Hans; Karlsson, Per; Domchek, Susan M.; Nathanson, Katherine L.; Osorio, Ana; Blanco, Ignacio; Lasa, Adriana; Benítez, Javier; Hamann, Ute; Hogervorst, Frans B.L.; Rookus, Matti A.; Collee, J. Margriet; Devilee, Peter; Ligtenberg, Marjolijn J.; van der Luijt, Rob B.; Aalfs, Cora M.; Waisfisz, Quinten; Wijnen, Juul; van Roozendaal, Cornelis E.P.; Peock, Susan; Cook, Margaret; Frost, Debra; Oliver, Clare; Platte, Radka; Evans, D. Gareth; Lalloo, Fiona; Eeles, Rosalind; Izatt, Louise; Davidson, Rosemarie; Chu, Carol; Eccles, Diana; Cole, Trevor; Hodgson, Shirley; Godwin, Andrew K.; Stoppa-Lyonnet, Dominique; Buecher, Bruno; Léoné, Mélanie; Bressac-de Paillerets, Brigitte; Remenieras, Audrey; Caron, Olivier; Lenoir, Gilbert M.; Sevenet, Nicolas; Longy, Michel; Ferrer, Sandra Fert; Prieur, Fabienne; Goldgar, David; Miron, Alexander; John, Esther M.; Buys, Saundra S.; Daly, Mary B.; Hopper, John L.; Terry, Mary Beth; Yassin, Yosuf; Gschwantler-Kaulich, Daphne; Staudigl, Christine; Hansen, Thomas v. O.; Barkardottir, Rosa Bjork; Kirchhoff, Tomas; Pal, Prodipto; Kosarin, Kristi; Offit, Kenneth; Piedmonte, Marion; Rodriguez, Gustavo C.; Wakeley, Katie; Boggess, John F.; Basil, Jack; Schwartz, Peter E.; Blank, Stephanie V.; Toland, Amanda E.; Montagna, Marco; Casella, Cinzia; Imyanitov, Evgeny N.; Allavena, Anna; Schmutzler, Rita K.; Versmold, Beatrix; Engel, Christoph; Meindl, Alfons; Ditsch, Nina; Arnold, Norbert; Niederacher, Dieter; Deißler, Helmut; Fiebig, Britta; Suttner, Christian; Schönbuchner, Ines; Gadzicki, Dorothea; Caldes, Trinidad; de la Hoya, Miguel; Pooley, Karen A.; Easton, Douglas F.; Chenevix-Trench, Georgia

    2009-01-01

    Genome-wide association studies of breast cancer have identified multiple single nucleotide polymorphisms (SNPs) that are associated with increased breast cancer risks in the general population. In a previous study, we demonstrated that the minor alleles at three of these SNPs, in FGFR2, TNRC9 and MAP3K1, also confer increased risks of breast cancer for BRCA1 or BRCA2 mutation carriers. Three additional SNPs rs3817198 at LSP1, rs13387042 at 2q35 and rs13281615 at 8q24 have since been reported to be associated with breast cancer in the general population, and in this study we evaluated their association with breast cancer risk in 9442 BRCA1 and 5665 BRCA2 mutation carriers from 33 study centres. The minor allele of rs3817198 was associated with increased breast cancer risk only for BRCA2 mutation carriers [hazard ratio (HR) = 1.16, 95% CI: 1.07–1.25, P-trend = 2.8 × 10−4]. The best fit for the association of SNP rs13387042 at 2q35 with breast cancer risk was a dominant model for both BRCA1 and BRCA2 mutation carriers (BRCA1: HR = 1.14, 95% CI: 1.04–1.25, P = 0.0047; BRCA2: HR = 1.18 95% CI: 1.04–1.33, P = 0.0079). SNP rs13281615 at 8q24 was not associated with breast cancer for either BRCA1 or BRCA2 mutation carriers, but the estimated association for BRCA2 mutation carriers (per-allele HR = 1.06, 95% CI: 0.98–1.14) was consistent with odds ratio estimates derived from population-based case–control studies. The LSP1 and 2q35 SNPs appear to interact multiplicatively on breast cancer risk for BRCA2 mutation carriers. There was no evidence that the associations vary by mutation type depending on whether the mutated protein is predicted to be stable or not. PMID:19656774

  10. Does tumorigenesis select for or against mutations of the DNA repair-associated genes BRCA2 and MRE11?: Considerations from somatic mutations in microsatellite unstable (MSI gastrointestinal cancers

    Directory of Open Access Journals (Sweden)

    Elghalbzouri-Maghrani Elhaam

    2006-01-01

    Full Text Available Abstract Background The BRCA2 and MRE11 proteins participate in the repair of double-strand DNA breaks by homologous recombination. Germline BRCA2 mutations predispose to ovarian, breast and pancreatic cancer, while a germline MRE11 mutation is associated with an ataxia telangiectasia-like disorder. Somatic mutations of BRCA2 are rare in typical sporadic cancers. In tumors having microsatellite instability (MSI, somatic truncating mutations in a poly [A] tract of BRCA2 are reported on occasion. Results We analyzed gastrointestinal MSI cancers by whole gene BRCA2 sequencing, finding heterozygous truncating mutations in seven (47% of 15 patients. There was no cellular functional defect in RAD51 focus-formation in three heterozygously mutated lines studied, although other potential functions of the BRCA2 protein could still be affected. A prior report of mutations in primary MSI tumors affecting the IVS5-(5–15 poly [T] tract of the MRE11 gene was confirmed and extended by analysis of the genomic sequence and protein expression in MSI cancer cell lines. Statistical analysis of the published MRE11 mutation rate in MSI tumors did not provide evidence for a selective pressure favoring biallelic mutations at this repeat. Conclusion Perhaps conflicting with common suspicions, the data are not compatible with selective pressures during tumorigenesis promoting the functional loss of BRCA2 and MRE11 in MSI tumors. Instead, these data fit closely with an absence of selective pressures acting on BRCA2 and MRE11 gene status during tumorigenesis.

  11. Activism and the Online Mediation Opportunity Structure

    DEFF Research Database (Denmark)

    Uldam, Julie

    2013-01-01

    The annual United Nations (UN) Framework Convention on Climate Change conferences provides a transnational mediation opportunity structure for activist networks to contest policies that favor market-based models for solving the climate crisis. Online technologies, including commercial social media...... climate change activism. This impedes possibilities for using online media to protest at the radical end of the climate justice movement spectrum. This article explores this interrelationship between activist demands and (online) modes of action through a focus on the mobilization efforts of London...

  12. Factors influencing ovulation and the risk of ovarian cancer in BRCA1 and BRCA2 mutation carriers.

    Science.gov (United States)

    Kotsopoulos, Joanne; Lubinski, Jan; Gronwald, Jacek; Cybulski, Cezary; Demsky, Rochelle; Neuhausen, Susan L; Kim-Sing, Charmaine; Tung, Nadine; Friedman, Susan; Senter, Leigha; Weitzel, Jeffrey; Karlan, Beth; Moller, Pal; Sun, Ping; Narod, Steven A

    2015-09-01

    The role of the lifetime number of ovulatory cycles has not been evaluated in the context of BRCA-associated ovarian cancer. Thus, we conducted a matched case-control study to evaluate the relationship between the cumulative number of ovulatory cycles (and contributing components) and risk of developing ovarian cancer in BRCA mutation carriers (1,329 cases and 5,267 controls). Information regarding reproductive and hormonal factors was collected from a routinely administered questionnaire. Conditional logistic regression was used to evaluate all associations. We observed a 45% reduction in the risk of developing ovarian cancer among women in the lowest vs. highest quartile of ovulatory cycles (OR = 0.55; 95% CI 0.41-0.75, p = 0.0001). Breastfeeding for more than 12 months was associated with a 38% (95% CI 0.48-0.79) and 50% (95% CI 0.29-0.84) reduction in risk among BRCA1 and BRCA2 mutation carriers, respectively. For oral contraceptive use, maximum benefit was seen with five or more years of use among BRCA1 mutation carriers (OR = 0.50; 95% CI 0.40-0.63) and three or more years for BRCA2 mutation carriers (OR = 0.42; 95% CI 0.22-0.83). Increasing parity was associated with a significant inverse trend among BRCA1 (OR = 0.87; 95% CI 0.79-0.96; p-trend = 0.005) but not BRCA2 mutation carriers (OR 0.98; 95% CI 0.81-1.19; p-trend = 0.85). A later age at menopause was associated with an increased risk in women with a BRCA1 mutation (OR trend = 1.18; 95% CI 1.03-1.35; p = 0.02). These findings support an important role of breastfeeding and oral contraceptive use for the primary prevention of ovarian cancer among women carrying BRCA mutations. PMID:25482078

  13. Association analysis of PALB2 and BRCA2 in bipolar disorder and schizophrenia in a scandinavian case-control sample

    DEFF Research Database (Denmark)

    Tesli, Martin; Athanasiu, Lavinia; Mattingsdal, Morten;

    2010-01-01

    ,868/2,938) and the STEP-UCL/ED-DUB-STEP2 study (n¿=¿2,558/3,274) in a meta-analysis which revealed a P-value of 1.2¿×¿10(-5) for association between PALB2 SNP rs420259 and BD (n¿=¿5,547/20,241). Neither the PALB2 SNP rs420259 nor the BRCA2 SNP rs9567552 were nominally significantly associated with the SCZ...... (Nominal P¿=¿0.00043). Additionally, we replicated the association between PALB2 SNP rs420259 and BD (Nominal P¿=¿0.025). We then combined our sample with another Nordic case-control sample (n¿=¿435/11,491) from Iceland, and added results from the Wellcome Trust Case Control Consortium (WTCCC) (n¿=¿1...

  14. Targeted prostate cancer screening in men with mutations in BRCA1 and BRCA2 detects aggressive prostate cancer: preliminary analysis of the results of the IMPACT study

    DEFF Research Database (Denmark)

    Mitra, Anita V; Bancroft, Elizabeth K; Barbachano, Yolanda;

    2011-01-01

    Study Type - Diagnostic (validating cohort)
Level of Evidence 1b OBJECTIVES: To evaluate the role of targeted prostate cancer screening in men with BRCA1 or BRCA2 mutations, an international study, IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening ...

  15. Presymptomatic testing for BRCA1 and BRCA2: how distressing are the pre-test weeks? Rotterdam/Leiden Genetics Working Group

    NARCIS (Netherlands)

    L.N. Lodder; P. Devilee (Peter); M.F. Niermeijer (Martinus); C.J. Cornelisse (Cees); P.G. Frets; R.W. Trijsburg (Wim); E.J. Meijers-Heijboer (Hanne); J.G.M. Klijn (Jan); H.J. Duivenvoorden (Hugo); A. Tibben (Arend); A. Wagner (Anja); C.A. van der Meer

    1999-01-01

    textabstractPresymptomatic DNA testing for autosomal dominant hereditary breast/ovarian cancer (HBOC) became an option after the identification of the BRCA1 and BRCA2 genes in 1994-1995. Healthy female mutation carriers have a high lifetime risk for breast cancer (56-87

  16. Evaluation of chromosome 6p22 as a breast cancer risk modifier locus in a follow-up study of BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Stevens, Kristen N; Wang, Xianshu; Fredericksen, Zachary; Pankratz, Vernon S; Greene, Mark H; Andrulis, Irene L; Thomassen, Mads; Caligo, Maria; Nathanson, Katherine L; Jakubowska, Anna; Osorio, Ana; Hamann, Ute; Godwin, Andrew K; Stoppa-Lyonnet, Dominique; Southey, Melissa; Buys, Saundra S; Singer, Christian F; Hansen, Thomas V O; Arason, Adalgeir; Offit, Kenneth; Piedmonte, Marion; Montagna, Marco; Imyanitov, Evgeny; Tihomirova, Laima; Sucheston, Lara; Beattie, Mary; Neuhausen, Susan L; Szabo, Csilla I; Simard, Jacques; Spurdle, Amanda B; Healey, Sue; Chen, Xiaoqing; Rebbeck, Timothy R; Easton, Douglas F; Chenevix-Trench, Georgia; Antoniou, Antonis C; Couch, Fergus J

    2012-01-01

    Several common germline variants identified through genome-wide association studies of breast cancer risk in the general population have recently been shown to be associated with breast cancer risk for BRCA1 and/or BRCA2 mutation carriers. When combined, these variants can identify marked differe...

  17. Cross-species comparison of aCGH data from mouse and human BRCA1- and BRCA2-mutated breast cancers

    NARCIS (Netherlands)

    Holstege, H.; Van Beers, E.; Velds, A.; Liu, X.; Joosse, S.A.; Klarenbeek, S.; Schut, E.; Kerkhoven, R.; Klijn, C.N.; Wessels, L.F.A.; Nederlof, P.M.; Jonkers, J.

    2010-01-01

    Background: Genomic gains and losses are a result of genomic instability in many types of cancers. BRCA1- and BRCA2-mutated breast cancers are associated with increased amounts of chromosomal aberrations, presumably due their functions in genome repair. Some of these genomic aberrations may harbor g

  18. Detection and precise mapping of germline rearrangements in BRCA1, BRCA2, MSH2, and MLH1 using zoom-in array comparative genomic hybridization (aCGH)

    DEFF Research Database (Denmark)

    Staaf, Johan; Törngren, Therese; Rambech, Eva; Johansson, Ulla; Persson, Camilla; Sellberg, Gunilla; Tellhed, Lina; Nilbert, Mef; Borg, Ake

    2008-01-01

    deletions or duplications occurring in BRCA1 (n=11), BRCA2 (n=2), MSH2 (n=7), or MLH1 (n=9). Additionally, we demonstrate its applicability for uncovering complex somatic rearrangements, exemplified by zoom-in analysis of the PTEN and CDKN2A loci in breast cancer cells. The sizes of rearrangements ranged...

  19. Common Breast Cancer Susceptibility Alleles and the Risk of Breast Cancer for BRCA1 and BRCA2 Mutation Carriers : Implications for Risk Prediction

    NARCIS (Netherlands)

    Antoniou, Antonis C.; Beesley, Jonathan; McGuffog, Lesley; Sinilnikova, Olga M.; Healey, Sue; Neuhausen, Susan L.; Ding, Yuan Chun; Rebbeck, Timothy R.; Weitzel, Jeffrey N.; Lynch, Henry T.; Isaacs, Claudine; Ganz, Patricia A.; Tomlinson, Gail; Olopade, Olufunmilayo I.; Couch, Fergus J.; Wang, Xianshu; Lindor, Noralane M.; Pankratz, Vernon S.; Radice, Paolo; Manoukian, Siranoush; Peissel, Bernard; Zaffaroni, Daniela; Barile, Monica; Viel, Alessandra; Allavena, Anna; Dall'Olio, Valentina; Peterlongo, Paolo; Szabo, Csilla I.; Zikan, Michal; Claes, Kathleen; Poppe, Bruce; Foretova, Lenka; Mai, Phuong L.; Greene, Mark H.; Rennert, Gad; Lejbkowicz, Flavio; Glendon, Gord; Ozcelik, Hilmi; Andrulis, Irene L.; Thomassen, Mads; Gerdes, Anne-Marie; Sunde, Lone; Cruger, Dorthe; Jensen, Uffe Birk; Caligo, Maria; Friedman, Eitan; Kaufman, Bella; Laitman, Yael; Milgrom, Roni; Dubrovsky, Maya; Cohen, Shimrit; Borg, Ake; Jernstroem, Helena; Lindblom, Annika; Rantala, Johanna; Stenmark-Askmalm, Marie; Melin, Beatrice; Nathanson, Kate; Domchek, Susan; Jakubowska, Ania; Lubinski, Jan; Huzarski, Tomasz; Osorio, Ana; Lasa, Adriana; Duran, Mercedes; Tejada, Maria-Isabel; Godino, Javier; Benitez, Javier; Hamann, Ute; Kriege, Mieke; Hoogerbrugge, Nicoline; van der Luijt, Rob B.; van Asperen, Christi J.; Devilee, Peter; Meijers-Heijboer, E. J.; Blok, Marinus J.; Aalfs, Cora M.; Hogervorst, Frans; Rookus, Matti; Cook, Margaret; Oliver, Clare; Frost, Debra; Conroy, Don; Evans, D. Gareth; Lalloo, Fiona; Pichert, Gabriella; Davidson, Rosemarie; Cole, Trevor; Cook, Jackie; Paterson, Joan; Hodgson, Shirley; Morrison, Patrick J.; Porteous, Mary E.; Walker, Lisa; Kennedy, M. John; Dorkins, Huw; Peock, Susan; Godwin, Andrew K.; Stoppa-Lyonnet, Dominique; de Pauw, Antoine; Mazoyer, Sylvie; Bonadona, Valerie; Lasset, Christine; Dreyfus, Helene; Leroux, Dominique; Hardouin, Agnes; Berthet, Pascaline; Faivre, Laurence; Loustalot, Catherine; Noguchi, Tetsuro; Sobol, Hagay; Rouleau, Etienne; Nogues, Catherine; Frenay, Marc; Venat-Bouvet, Laurence; Hopper, John L.; Daly, Mary B.; Terry, Mary B.; John, Esther M.; Buys, Saundra S.; Yassin, Yosuf; Miron, Alexander; Goldgar, David; Singer, Christian F.; Dressler, Anne Catharina; Gschwantler-Kaulich, Daphne; Pfeiler, Georg; Hansen, Thomas V. O.; Jnson, Lars; Agnarsson, Bjarni A.; Kirchhoff, Tomas; Offit, Kenneth; Devlin, Vincent; Dutra-Clarke, Ana; Piedmonte, Marion; Rodriguez, Gustavo C.; Wakeley, Katie; Boggess, John F.; Basil, Jack; Schwartz, Peter E.; Blank, Stephanie V.; Toland, Amanda Ewart; Montagna, Marco; Casella, Cinzia; Imyanitov, Evgeny; Tihomirova, Laima; Blanco, Ignacio; Lazaro, Conxi; Ramus, Susan J.; Sucheston, Lara; Karlan, Beth Y.; Gross, Jenny; Schmutzler, Rita; Wappenschmidt, Barbara; Engel, Christoph; Meindl, Alfons; Lochmann, Magdalena; Arnold, Norbert; Heidemann, Simone; Varon-Mateeva, Raymonda; Niederacher, Dieter; Sutter, Christian; Deissler, Helmut; Gadzicki, Dorothea; Preisler-Adams, Sabine; Kast, Karin; Schoenbuchner, Ines; Caldes, Trinidad; de la Hoya, Miguel; Aittomaeki, Kristiina; Nevanlinna, Heli; Simard, Jacques; Spurdle, Amanda B.; Holland, Helene; Chen, Xiaoqing; Platte, Radka; Chenevix-Trench, Georgia; Easton, Douglas F.

    2010-01-01

    The known breast cancer susceptibility polymorphisms in FGFR2, TNRC9/TOX3, MAP3K1, LSP1, and 2q35 confer increased risks of breast cancer for BRCA1 or BRCA2 mutation carriers. We evaluated the associations of 3 additional single nucleotide polymorphisms (SNPs), rs4973768 in SLC4A7/NEK10, rs6504950 i

  20. Common breast cancer susceptibility alleles and the risk of breast cancer for BRCA1 and BRCA2 mutation carriers: implications for risk prediction

    DEFF Research Database (Denmark)

    Antoniou, Antonis C; Beesley, Jonathan; McGuffog, Lesley;

    2010-01-01

    The known breast cancer susceptibility polymorphisms in FGFR2, TNRC9/TOX3, MAP3K1, LSP1, and 2q35 confer increased risks of breast cancer for BRCA1 or BRCA2 mutation carriers. We evaluated the associations of 3 additional single nucleotide polymorphisms (SNPs), rs4973768 in SLC4A7/NEK10, rs650495...

  1. Common breast cancer susceptibility alleles and the risk of breast cancer for BRCA1 and BRCA2 mutation carriers: Implications for risk prediction

    NARCIS (Netherlands)

    A.C. Antoniou (Antonis); J. Beesley (Jonathan); L. McGuffog (Lesley); O. Sinilnikova (Olga); S. Healey (Sue); S.L. Neuhausen (Susan); Y.C. Ding (Yuan); R. Rebbeck (Timothy); J.N. Weitzel (Jeffrey); H. Lynch (Henry); C. Isaacs (Claudine); P.A. Ganz (Patricia); G. Tomlinson (Gail); O.I. Olopade (Olofunmilayo); F.J. Couch (Fergus); X. Wang (Xing); N.M. Lindor (Noralane); V.S. Pankratz (Shane); P. Radice (Paolo); S. Manoukian (Siranoush); B. Peissel (Bernard); D. Zaffaroni (D.); M. Barile (Monica); A. Viel (Alessandra); A. Allavena (Anna); V. Dall'Olio (Valentina); P. Peterlongo (Paolo); C. Szabo (Csilla); M. Zikan (Michal); K. Claes (Kathleen); B. Poppe (Bruce); L. Foretova (Lenka); P.L. Mai (Phuong); M.H. Greene (Mark); G. Rennert (Gad); F. Lejbkowicz (Flavio); G. Glendon (Gord); H. Ozcelik (Hilmi); I.L. Andrulis (Irene); M. Thomassen (Mads); A-M. Gerdes (Anne-Marie); L. Sunde (Lone); D. Cruger (Dorthe); U.B. Jensen; M.A. Caligo (Maria); E. Friedman (Eitan); B. Kaufman (Bella); Y. Laitman (Yael); R. Milgrom (Roni); M. Dubrovsky (Maya); S. Cohen (Shimrit); Å. Borg (Åke); H. Jernström (H.); A. Lindblom (Annika); J. Rantala (Johanna); M. Stenmark-Askmalm (M.); B. Melin (Beatrice); K.L. Nathanson (Katherine); S.M. Domchek (Susan); A. Jakubowska (Anna); J. Lubinski (Jan); T. Huzarski (Tomasz); A. Osorio (Ana); A. Lasa (Adriana); M. Durán (Mercedes); M.I. Tejada; J. Godino (Javier); J. Benitez (Javier); U. Hamann (Ute); M. Kriege (Mieke); N. Hoogerbrugge (Nicoline); R.B. van der Luijt (Rob); C.J. van Asperen (Christi); P. Devilee (Peter); E.J. Meijers-Heijboer (Hanne); M.J. Blok (Marinus); C.M. Aalfs (Cora); F.B.L. Hogervorst (Frans); M.A. Rookus (Matti); M. Cook (Margaret); C.T. Oliver (Clare); D. Frost (Debra); D. Conroy (Don); D.G. Evans (Gareth); F. Lalloo (Fiona); G. Pichert (Gabriella); R. Davidson (Rosemarie); T.J. Cole (Trevor); J. Paterson (Joan); S.V. Hodgson (Shirley); P.J. Morrison (Patrick); M.E. Porteous (Mary); L.J. Walker (Lisa); M.J. Kennedy (John); H. Dorkins (Huw); S. Peock (Susan); A.K. Godwin (Andrew); D. Stoppa-Lyonnet (Dominique); A. de Pauw (Antoine); S. Mazoyer (Sylvie); V. Bonadona (Valérie); C. Lasset (Christine); H. Dreyfus (Hélène); D. Leroux (Dominique); A. hardouin (Agnès); P. Berthet (Pascaline); L. Faivre (Laurence); C. Loustalot (Catherine); T. Noguchi (Tetsuro); H. Sobol (Hagay); E. Rouleau (Etienne); C. Nogues (Catherine); M. Frenay (Marc); L. Vénat-Bouvet (Laurence); J. Hopper (John); M.J. Daly (Mark); M-B. Terry (Mary-beth); E.M. John (Esther); S.S. Buys (Saundra); Y. Yassin (Yosuf); A. Miron (Alexander); D. Goldgar (David); C.F. Singer (Christian); C. Dressler (Catherina); D. Gschwantler-Kaulich (Daphne); G. Pfeiler (Georg); T.V.O. Hansen (Thomas); L. Jnson (Lars); B.A. Agnarsson (Bjarni); T. Kircchoff (Tomas); K. Offit (Kenneth); V. Devlin (Vincent); A. Dutra-Clarke (Ana); M. Piedmonte (Marion); G.C. Rodriguez (Gustavo); K. Wakeley (Katie); J.F. Boggess (John); J. Basil (Jack); P.E. Schwartz (Peter); S.V. Blank (Stephanie); A.E. Toland (Amanda); M. Montagna (Marco); C. Casella (Cinzia); E.N. Imyanitov (Evgeny); L. Tihomirova (Laima); I. Blanco (Ignacio); C. Lazaro (Conxi); S.J. Ramus (Susan); L. Sucheston (Lara); B.Y. Karlan (Beth); J. Gross (Jenny); R.K. Schmutzler (Rita); B. Wapenschmidt (Barbara); C. Engel (Christoph); A. Meindl (Alfons); M. Lochmann (Magdalena); N. Arnold (Norbert); S. Heidemann (Simone); R. Varon-Mateeva (Raymonda); D. Niederacher (Dieter); C. Sutter (Christian); H. Deissler (Helmut); D. Gadzicki (Dorothea); S. Preisler-Adams (Sabine); K. Kast (Karin); I. Schönbuchner (Ines); T. Caldes (Trinidad); M. de La Hoya (Miguel); K. Aittomäki (Kristiina); H. Nevanlinna (Heli); J. Simard (Jacques); A.B. Spurdle (Amanda); H. Holland (Helene); G. Chenevix-Trench (Georgia); R. Platte (Radka); D.F. Easton (Douglas)

    2010-01-01

    textabstractThe known breast cancer susceptibility polymorphisms in FGFR2, TNRC9/TOX3, MAP3K1, LSP1, and 2q35 confer increased risks of breast cancer for BRCA1 or BRCA2 mutation carriers. We evaluated the associations of 3 additional single nucleotide polymorphisms (SNPs), rs4973768 in SLC4A7/NEK10,

  2. DNA glycosylases involved in base excision repair may be associated with cancer risk in BRCA1 and BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Osorio, Ana; Milne, Roger L; Kuchenbaecker, Karoline;

    2014-01-01

    Single Nucleotide Polymorphisms (SNPs) in genes involved in the DNA Base Excision Repair (BER) pathway could be associated with cancer risk in carriers of mutations in the high-penetrance susceptibility genes BRCA1 and BRCA2, given the relation of synthetic lethality that exists between one of th...

  3. Predictive Factors for BRCA1 and BRCA2 Genetic Testing in an Asian Clinic-Based Population.

    Directory of Open Access Journals (Sweden)

    Edward S Y Wong

    Full Text Available The National Comprehensive Cancer Network (NCCN has proposed guidelines for the genetic testing of the BRCA1 and BRCA2 genes, based on studies in western populations. This current study assessed potential predictive factors for BRCA mutation probability, in an Asian population.A total of 359 breast cancer patients, who presented with either a family history (FH of breast and/or ovarian cancer or early onset breast cancer, were accrued at the National Cancer Center Singapore (NCCS. The relationships between clinico-pathological features and mutational status were calculated using the Chi-squared test and binary logistic regression analysis.Of 359 patients, 45 (12.5% had deleterious or damaging missense mutations in BRCA1 and/or BRCA2. BRCA1 mutations were more likely to be found in ER-negative than ER-positive breast cancer patients (P=0.01. Moreover, ER-negative patients with BRCA mutations were diagnosed at an earlier age (40 vs. 48 years, P=0.008. Similarly, triple-negative breast cancer (TNBC patients were more likely to have BRCA1 mutations (P=0.001 and that these patients were diagnosed at a relatively younger age than non-TNBC patients (38 vs. 46 years, P=0.028. Our analysis has confirmed that ER-negative status, TNBC status and a FH of hereditary breast and ovarian cancer (HBOC are strong factors predicting the likelihood of having BRCA mutations.Our study provides evidence that TNBC or ER-negative patients may benefit from BRCA genetic testing, particularly younger patients (<40 years or those with a strong FH of HBOC, in Asian patients.

  4. Common breast cancer susceptibility alleles and the risk of breast cancer for BRCA1 and BRCA2 mutation carriers: implications for risk prediction

    Science.gov (United States)

    Antoniou, Antonis C; Beesley, Jonathan; McGuffog, Lesley; Sinilnikova, Olga M.; Healey, Sue; Neuhausen, Susan L.; Ding, Yuan Chun; Rebbeck, Timothy R.; Weitzel, Jeffrey N.; Lynch, Henry T.; Isaacs, Claudine; Ganz, Patricia A.; Tomlinson, Gail; Olopade, Olufunmilayo I.; Couch, Fergus J.; Wang, Xianshu; Lindor, Noralane M.; Pankratz, Vernon S.; Radice, Paolo; Manoukian, Siranoush; Peissel, Bernard; Zaffaroni, Daniela; Barile, Monica; Viel, Alessandra; Allavena, Anna; Dall’Olio, Valentina; Peterlongo, Paolo; Szabo, Csilla I.; Zikan, Michal; Claes, Kathleen; Poppe, Bruce; Foretova, Lenka; Mai, Phuong L.; Greene, Mark H.; Rennert, Gad; Lejbkowicz, Flavio; Glendon, Gord; Ozcelik, Hilmi; Andrulis, Irene L.; Thomassen, Mads; Gerdes, Anne-Marie; Sunde, Lone; Cruger, Dorthe; Jensen, Uffe Birk; Caligo, Maria; Friedman, Eitan; Kaufman, Bella; Laitman, Yael; Milgrom, Roni; Dubrovsky, Maya; Cohen, Shimrit; Borg, Ake; Jernström, Helena; Lindblom, Annika; Rantala, Johanna; Stenmark-Askmalm, Marie; Melin, Beatrice; Nathanson, Kate; Domchek, Susan; Jakubowska, Ania; Lubinski, Jan; Huzarski, Tomasz; Osorio, Ana; Lasa, Adriana; Durán, Mercedes; Tejada, Maria-Isabel; Godino, Javier; Benitez, Javier; Hamann, Ute; Kriege, Mieke; Hoogerbrugge, Nicoline; van der Luijt, Rob B; van Asperen, Christi J; Devilee, Peter; Meijers-Heijboer, E.J.; Blok, Marinus J; Aalfs, Cora M.; Hogervorst, Frans; Rookus, Matti; Cook, Margaret; Oliver, Clare; Frost, Debra; Conroy, Don; Evans, D. Gareth; Lalloo, Fiona; Pichert, Gabriella; Davidson, Rosemarie; Cole, Trevor; Cook, Jackie; Paterson, Joan; Hodgson, Shirley; Morrison, Patrick J.; Porteous, Mary E.; Walker, Lisa; Kennedy, M. John; Dorkins, Huw; Peock, Susan; Godwin, Andrew K.; Stoppa-Lyonnet, Dominique; de Pauw, Antoine; Mazoyer, Sylvie; Bonadona, Valérie; Lasset, Christine; Dreyfus, Hélène; Leroux, Dominique; Hardouin, Agnès; Berthet, Pascaline; Faivre, Laurence; Loustalot, Catherine; Noguchi, Tetsuro; Sobol, Hagay; Rouleau, Etienne; Nogues, Catherine; Frénay, Marc; Vénat-Bouvet, Laurence; Hopper, John L.; Daly, Mary B.; Terry, Mary B.; John, Esther M.; Buys, Saundra S.; Yassin, Yosuf; Miron, Alex; Goldgar, David; Singer, Christian F.; Dressler, Anne Catharina; Gschwantler-Kaulich, Daphne; Pfeiler, Georg; Hansen, Thomas V. O.; Jønson, Lars; Agnarsson, Bjarni A.; Kirchhoff, Tomas; Offit, Kenneth; Devlin, Vincent; Dutra-Clarke, Ana; Piedmonte, Marion; Rodriguez, Gustavo C.; Wakeley, Katie; Boggess, John F.; Basil, Jack; Schwartz, Peter E.; Blank, Stephanie V.; Toland, Amanda Ewart; Montagna, Marco; Casella, Cinzia; Imyanitov, Evgeny; Tihomirova, Laima; Blanco, Ignacio; Lazaro, Conxi; Ramus, Susan J.; Sucheston, Lara; Karlan, Beth Y.; Gross, Jenny; Schmutzler, Rita; Wappenschmidt, Barbara; Engel, Christoph; Meindl, Alfons; Lochmann, Magdalena; Arnold, Norbert; Heidemann, Simone; Varon-Mateeva, Raymonda; Niederacher, Dieter; Sutter, Christian; Deissler, Helmut; Gadzicki, Dorothea; Preisler-Adams, Sabine; Kast, Karin; Schönbuchner, Ines; Caldes, Trinidad; de la Hoya, Miguel; Aittomäki, Kristiina; Nevanlinna, Heli; Simard, Jacques; Spurdle, Amanda B.; Holland, Helene; Chen, Xiaoqing; Platte, Radka; Chenevix-Trench, Georgia; Easton, Douglas F.

    2010-01-01

    The known breast cancer (BC) susceptibility polymorphisms in FGFR2, TNRC9/TOX3, MAP3K1,LSP1 and 2q35 confer increased risks of BC for BRCA1 or BRCA2 mutation carriers. We evaluated the associations of three additional SNPs, rs4973768 in SLC4A7/NEK10, rs6504950 in STXBP4/COX11 and rs10941679 at 5p12 and reanalyzed the previous associations using additional carriers in a sample of 12,525 BRCA1 and 7,409 BRCA2 carriers. Additionally, we investigated potential interactions between SNPs and assessed the implications for risk prediction. The minor alleles of rs4973768 and rs10941679 were associated with increased BC risk for BRCA2 carriers (per-allele Hazard Ratio (HR)=1.10, 95%CI:1.03-1.18, p=0.006 and HR=1.09, 95%CI:1.01-1.19, p=0.03, respectively). Neither SNP was associated with BC risk for BRCA1 carriers and rs6504950 was not associated with BC for either BRCA1 or BRCA2 carriers. Of the nine polymorphisms investigated, seven were associated with BC for BRCA2 carriers (FGFR2, TOX3, MAP3K1, LSP1, 2q35, SLC4A7, 5p12, p-values:7×10−11-0.03), but only TOX3 and 2q35 were associated with the risk for BRCA1 carriers (p=0.0049, 0.03 respectively). All risk associated polymorphisms appear to interact multiplicatively on BC risk for mutation carriers. Based on the joint genotype distribution of the seven risk associated SNPs in BRCA2 mutation carriers, the 5% of BRCA2 carriers at highest risk (i.e. between 95th and 100th percentiles) were predicted to have a probability between 80% and 96% of developing BC by age 80, compared with 42-50% for the 5% of carriers at lowest risk. Our findings indicated that these risk differences may be sufficient to influence the clinical management of mutation carriers. PMID:21118973

  5. Prevalence of BRCA1 and BRCA2 gene mutations in families with medium and high risk of breast and ovarian cancer in Brazil

    Directory of Open Access Journals (Sweden)

    V.F. Esteves

    2009-05-01

    Full Text Available Of all malignant neoplasias affecting women, breast cancer has the highest incidence rate in Brazil. The objective of the present study was to determine the frequency of genetic modifications in families with medium and high risk for breast and ovarian cancer from different regions of Brazil. An exploratory, descriptive study was carried out on the prevalence of the BRCA1 and BRCA2 mutations in case series of high-risk families for breast and/or ovarian cancer. After heredogram construction, a blood sample was taken and DNA extraction was performed in all index cases. The protein truncation test was used to screen for truncated mutations in exon 11 of the BRCA1 gene and in exons 10 and 11 of the BRCA2 gene. Of the 612 individuals submitted to genetic testing, 21 (3.4%, 19 women and 2 men, had mutations in the BRCA1 or BRCA2 genes. Of the 19 BRCA1 mutations found in the 18 participants, 7 consisted of ins6kb mutations, 4 were 5382insC, 3 were 2156delGinsCC, 2 were 185delAG, 1 was C1201G, 1 was C3522T, and 1 was 3450del4. With respect to the BRCA2 gene, 3 mutations were found: 5878del10, 5036delA and 4232insA (one case each. The prevalence of germline mutations in the BRCA1 and BRCA2 genes found in the present study was lower than reported by other studies on high-risk Brazilian populations. The inclusion of individuals with medium risk may have contributed to the lower prevalence observed.

  6. DNA glycosylases involved in base excision repair may be associated with cancer risk in BRCA1 and BRCA2 mutation carriers.

    Directory of Open Access Journals (Sweden)

    Ana Osorio

    2014-04-01

    Full Text Available Single Nucleotide Polymorphisms (SNPs in genes involved in the DNA Base Excision Repair (BER pathway could be associated with cancer risk in carriers of mutations in the high-penetrance susceptibility genes BRCA1 and BRCA2, given the relation of synthetic lethality that exists between one of the components of the BER pathway, PARP1 (poly ADP ribose polymerase, and both BRCA1 and BRCA2. In the present study, we have performed a comprehensive analysis of 18 genes involved in BER using a tagging SNP approach in a large series of BRCA1 and BRCA2 mutation carriers. 144 SNPs were analyzed in a two stage study involving 23,463 carriers from the CIMBA consortium (the Consortium of Investigators of Modifiers of BRCA1 and BRCA2. Eleven SNPs showed evidence of association with breast and/or ovarian cancer at p<0.05 in the combined analysis. Four of the five genes for which strongest evidence of association was observed were DNA glycosylases. The strongest evidence was for rs1466785 in the NEIL2 (endonuclease VIII-like 2 gene (HR: 1.09, 95% CI (1.03-1.16, p = 2.7 × 10(-3 for association with breast cancer risk in BRCA2 mutation carriers, and rs2304277 in the OGG1 (8-guanine DNA glycosylase gene, with ovarian cancer risk in BRCA1 mutation carriers (HR: 1.12 95%CI: 1.03-1.21, p = 4.8 × 10(-3. DNA glycosylases involved in the first steps of the BER pathway may be associated with cancer risk in BRCA1/2 mutation carriers and should be more comprehensively studied.

  7. A non-synonymous polymorphism in IRS1 modifies risk of developing breast and ovarian cancers in BRCA1 and ovarian cancer in BRCA2 mutation carriers

    Science.gov (United States)

    Ding, Yuan C.; McGuffog, Lesley; Healey, Sue; Friedman, Eitan; Laitman, Yael; Shani-Shimon–Paluch; Kaufman, Bella; Liljegren, Annelie; Lindblom, Annika; Olsson, Håkan; Kristoffersson, Ulf; Stenmark-Askmalm, Marie; Melin, Beatrice; Domchek, Susan M.; Nathanson, Katherine L.; Rebbeck, Timothy R.; Jakubowska, Anna; Lubinski, Jan; Jaworska, Katarzyna; Durda, Katarzyna; Gronwald, Jacek; Huzarski, Tomasz; Cybulski, Cezary; Byrski, Tomasz; Osorio, Ana; Cajal, Teresa Ramóny; Stavropoulou, Alexandra V; Benítez, Javier; Hamann, Ute; Rookus, Matti; Aalfs, Cora M.; de Lange, Judith L.; Meijers-Heijboer, Hanne E.J.; Oosterwijk, Jan C.; van Asperen, Christi J.; García, Encarna B. Gómez; Hoogerbrugge, Nicoline; Jager, Agnes; van der Luijt, Rob B.; Easton, Douglas F.; Peock, Susan; Frost, Debra; Ellis, Steve D.; Platte, Radka; Fineberg, Elena; Evans, D. Gareth; Lalloo, Fiona; Izatt, Louise; Eeles, Ros; Adlard, Julian; Davidson, Rosemarie; Eccles, Diana; Cole, Trevor; Cook, Jackie; Brewer, Carole; Tischkowitz, Marc; Godwin, Andrew K.; Pathak, Harsh; Stoppa-Lyonnet, Dominique; Sinilnikova, Olga M.; Mazoyer, Sylvie; Barjhoux, Laure; Léoné, Mélanie; Gauthier-Villars, Marion; Caux-Moncoutier, Virginie; de Pauw, Antoine; Hardouin, Agnès; Berthet, Pascaline; Dreyfus, Hélène; Ferrer, Sandra Fert; Collonge-Rame, Marie-Agnès; Sokolowska, Johanna; Buys, Saundra; Daly, Mary; Miron, Alex; Terry, Mary Beth; Chung, Wendy; John, Esther M; Southey, Melissa; Goldgar, David; Singer, Christian F; Maria, Muy-Kheng Tea; Gschwantler-Kaulich, Daphne; Fink-Retter, Anneliese; Hansen, Thomas v. O.; Ejlertsen, Bent; Johannsson, Oskar Th.; Offit, Kenneth; Sarrel, Kara; Gaudet, Mia M.; Vijai, Joseph; Robson, Mark; Piedmonte, Marion R; Andrews, Lesley; Cohn, David; DeMars, Leslie R.; DiSilvestro, Paul; Rodriguez, Gustavo; Toland, Amanda Ewart; Montagna, Marco; Agata, Simona; Imyanitov, Evgeny; Isaacs, Claudine; Janavicius, Ramunas; Lazaro, Conxi; Blanco, Ignacio; Ramus, Susan J; Sucheston, Lara; Karlan, Beth Y.; Gross, Jenny; Ganz, Patricia A.; Beattie, Mary S.; Schmutzler, Rita K.; Wappenschmidt, Barbara; Meindl, Alfons; Arnold, Norbert; Niederacher, Dieter; Preisler-Adams, Sabine; Gadzicki, Dorotehea; Varon-Mateeva, Raymonda; Deissler, Helmut; Gehrig, Andrea; Sutter, Christian; Kast, Karin; Nevanlinna, Heli; Aittomäki, Kristiina; Simard, Jacques; Spurdle, Amanda B.; Beesley, Jonathan; Chen, Xiaoqing; Tomlinson, Gail E.; Weitzel, Jeffrey; Garber, Judy E.; Olopade, Olufunmilayo I.; Rubinstein, Wendy S.; Tung, Nadine; Blum, Joanne L.; Narod, Steven A.; Brummel, Sean; Gillen, Daniel L.; Lindor, Noralane; Fredericksen, Zachary; Pankratz, Vernon S.; Couch, Fergus J.; Radice, Paolo; Peterlongo, Paolo; Greene, Mark H.; Loud, Jennifer T.; Mai, Phuong L.; Andrulis, Irene L.; Glendon, Gord; Ozcelik, Hilmi; Gerdes, Anne-Marie; Thomassen, Mads; Jensen, Uffe Birk; Skytte, Anne-Bine; Caligo, Maria A.; Lee, Andrew; Chenevix-Trench, Georgia; Antoniou, Antonis C; Neuhausen, Susan L.

    2012-01-01

    Background We previously reported significant associations between genetic variants in insulin receptor substrate 1 (IRS1) and breast cancer risk in women carrying BRCA1 mutations. The objectives of this study were to investigate whether the IRS1 variants modified ovarian cancer risk and were associated with breast cancer risk in a larger cohort of BRCA1 and BRCA2 mutation carriers. Methods IRS1 rs1801123, rs1330645, and rs1801278 were genotyped in samples from 36 centers in the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Data were analyzed by a retrospective cohort approach modeling the associations with breast and ovarian cancer risks simultaneously. Analyses were stratified by BRCA1 and BRCA2 status and mutation class in BRCA1 carriers. Results Rs1801278 (Gly972Arg) was associated with ovarian cancer risk for both BRCA1 [Hazard ratio (HR) = 1.43; 95% CI: 1.06–1.92; p = 0.019] and BRCA2 mutation carriers (HR=2.21; 95% CI: 1.39–3.52, p=0.0008). For BRCA1 mutation carriers, the breast cancer risk was higher in carriers with class 2 mutations than class 1 (mutations (class 2 HR=1.86, 95% CI: 1.28–2.70; class 1 HR=0.86, 95%CI:0.69–1.09; p-for difference=0.0006). Rs13306465 was associated with ovarian cancer risk in BRCA1 class 2 mutation carriers (HR = 2.42; p = 0.03). Conclusion The IRS1 Gly972Arg SNP, which affects insulin-like growth factor and insulin signaling, modifies ovarian cancer risk in BRCA1 and BRCA2 mutation carriers and breast cancer risk in BRCA1 class 2 mutation carriers. Impact These findings may prove useful for risk prediction for breast and ovarian cancers in BRCA1 and BRCA2 mutation carriers. PMID:22729394

  8. Family Structure and Mediators of Adolescent Drug Use

    Science.gov (United States)

    Broman, Clifford L.; Li, Xin; Reckase, Mark

    2008-01-01

    This study investigates how family structure is associated with adolescent drug use and how parenting, peer use, religiosity, and neighborhood problems may mediate the relationship. The authors use structural equation modeling to examine the relationship between family structure and drug use across race, and examine potential mediators. Using data…

  9. Microbial mediation of complex subterranean mineral structures

    Science.gov (United States)

    Tisato, Nicola; Torriani, Stefano F. F.; Monteux, Sylvain; Sauro, Francesco; de Waele, Jo; Tavagna, Maria Luisa; D'Angeli, Ilenia M.; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso R. R.

    2015-10-01

    Helictites—an enigmatic type of mineral structure occurring in some caves—differ from classical speleothems as they develop with orientations that defy gravity. While theories for helictite formation have been forwarded, their genesis remains equivocal. Here, we show that a remarkable suite of helictites occurring in Asperge Cave (France) are formed by biologically-mediated processes, rather than abiotic processes as had hitherto been proposed. Morphological and petro-physical properties are inconsistent with mineral precipitation under purely physico-chemical control. Instead, microanalysis and molecular-biological investigation reveals the presence of a prokaryotic biofilm intimately associated with the mineral structures. We propose that microbially-influenced mineralization proceeds within a gliding biofilm which serves as a nucleation site for CaCO3, and where chemotaxis influences the trajectory of mineral growth, determining the macroscopic morphology of the speleothems. The influence of biofilms may explain the occurrence of similar speleothems in other caves worldwide, and sheds light on novel biomineralization processes.

  10. Cross-species comparison of aCGH data from mouse and human BRCA1- and BRCA2-mutated breast cancers

    International Nuclear Information System (INIS)

    Genomic gains and losses are a result of genomic instability in many types of cancers. BRCA1- and BRCA2-mutated breast cancers are associated with increased amounts of chromosomal aberrations, presumably due their functions in genome repair. Some of these genomic aberrations may harbor genes whose absence or overexpression may give rise to cellular growth advantage. So far, it has not been easy to identify the driver genes underlying gains and losses. A powerful approach to identify these driver genes could be a cross-species comparison of array comparative genomic hybridization (aCGH) data from cognate mouse and human tumors. Orthologous regions of mouse and human tumors that are commonly gained or lost might represent essential genomic regions selected for gain or loss during tumor development. To identify genomic regions that are associated with BRCA1- and BRCA2-mutated breast cancers we compared aCGH data from 130 mouse Brca1Δ/Δ;p53Δ/Δ, Brca2Δ/Δ;p53Δ/Δ and p53Δ/Δ mammary tumor groups with 103 human BRCA1-mutated, BRCA2-mutated and non-hereditary breast cancers. Our genome-wide cross-species analysis yielded a complete collection of loci and genes that are commonly gained or lost in mouse and human breast cancer. Principal common CNAs were the well known MYC-associated gain and RB1/INTS6-associated loss that occurred in all mouse and human tumor groups, and the AURKA-associated gain occurred in BRCA2-related tumors from both species. However, there were also important differences between tumor profiles of both species, such as the prominent gain on chromosome 10 in mouse Brca2Δ/Δ;p53Δ/Δ tumors and the PIK3CA associated 3q gain in human BRCA1-mutated tumors, which occurred in tumors from one species but not in tumors from the other species. This disparity in recurrent aberrations in mouse and human tumors might be due to differences in tumor cell type or genomic organization between both species. The selection of the oncogenome during mouse and

  11. Protein-mediated surface structuring in biomembranes

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    Maggio B.

    2005-01-01

    Full Text Available The lipids and proteins of biomembranes exhibit highly dissimilar conformations, geometrical shapes, amphipathicity, and thermodynamic properties which constrain their two-dimensional molecular packing, electrostatics, and interaction preferences. This causes inevitable development of large local tensions that frequently relax into phase or compositional immiscibility along lateral and transverse planes of the membrane. On the other hand, these effects constitute the very codes that mediate molecular and structural changes determining and controlling the possibilities for enzymatic activity, apposition and recombination in biomembranes. The presence of proteins constitutes a major perturbing factor for the membrane sculpturing both in terms of its surface topography and dynamics. We will focus on some results from our group within this context and summarize some recent evidence for the active involvement of extrinsic (myelin basic protein, integral (Folch-Lees proteolipid protein and amphitropic (c-Fos and c-Jun proteins, as well as a membrane-active amphitropic phosphohydrolytic enzyme (neutral sphingomyelinase, in the process of lateral segregation and dynamics of phase domains, sculpturing of the surface topography, and the bi-directional modulation of the membrane biochemical reactivity.

  12. Response to a Third-Line Mitomycin C (MMC-Based Chemotherapy in a Patient with Metastatic Pancreatic Adenocarcinoma Carrying Germline BRCA2 Mutation

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    Pavani Chalasani

    2008-05-01

    Full Text Available Context Gemcitabine remains the mainstay of palliative chemotherapy for those patients with unresectable or metastatic pancreatic cancer. Objective radiological responses to gemcitabine are rare and reported median survival is only about six months. New therapeutic concepts and strategies are needed in order to improve those dismal statistics. Case report We report here a case of a patient with metastatic pancreatic cancer responding to a third-line therapy with combination of mitomycin C and capecitabine. Interestingly, the patient had a strong family history of breast cancer and tested positive to germline BRCA2 mutation. Conclusion We feel that this is of interest because of preclinical reports of increased sensitivity of pancreatic cells carrying BRCA2 mutations to DNA-intercalating agents such as mitomycin C. Further research and clinical trials are warranted to support this novel concept.

  13. Durable Clinical Benefit of Pertuzumab in a Young Patient with BRCA2 Mutation and HER2-Overexpressing Breast Cancer Involving the Brain

    Directory of Open Access Journals (Sweden)

    Anna Koumarianou

    2016-01-01

    Full Text Available Patients with HER2-positive breast cancer and brain metastases have limited treatment options, and, as a result of their poor performance status and worse prognosis, they are underrepresented in clinical trials. Not surprisingly, these patients may not be fit enough to receive any active treatment and are offered supportive therapy. BRCA2 mutations are reported to be rarely associated with HER2-overexpressing advanced breast cancer and even more rarely with brain metastases at diagnosis. We report on a BRCA2-positive breast cancer patient with metastatic disease in multiple sites, including the brain, and poor performance status who exhibited an extraordinary clinical and imaging response to the novel anti-HER2 therapy pertuzumab after multiple lines of therapy including anti-HER2 targeting. To our knowledge, the clinicopathologic and therapeutic characteristics of this patient point to a unique case and an urgent need for further investigation of pertuzumab in patients with brain metastases.

  14. Germline ATM mutational analysis in BRCA1/BRCA2 negative hereditary breast cancer families by MALDI-TOF mass spectrometry.

    Science.gov (United States)

    Graña, B; Fachal, L; Darder, E; Balmaña, J; Ramón Y Cajal, T; Blanco, I; Torres, A; Lázaro, C; Diez, O; Alonso, C; Santamariña, M; Velasco, A; Teulé, A; Lasa, A; Blanco, A; Izquierdo, A; Borràs, J; Gutiérrez-Enríquez, S; Vega, A; Brunet, J

    2011-07-01

    Biallelic inactivation of ATM gene causes the rare autosomal recessive disorder Ataxia-telangiectasia (A-T). Female relatives of A-T patients have a two-fold higher risk of developing breast cancer (BC) compared with the general population. ATM mutation carrier identification is laborious and expensive, therefore, a more rapid and directed strategy for ATM mutation profiling is needed. We designed a case-control study to determine the prevalence of 32 known ATM mutations causing A-T in Spanish population in 323 BRCA1/BRCA2 negative hereditary breast cancer (HBC) cases and 625 matched Spanish controls. For the detection of the 32 ATM mutations we used the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry technique. We identified one patient carrier of the c.8264_8268delATAAG ATM mutation. This mutation was not found in the 625 controls. These results suggest a low frequency of these 32 A-T causing mutations in the HBC cases in our population. Further case-control studies analyzing the entire coding and flanking sequences of the ATM gene are warranted in Spanish BC patients to know its implication in BC predisposition. PMID:21445571

  15. The role of germline alterations in the DNA damage response genes BRIP1 and BRCA2 in melanoma susceptibility.

    Science.gov (United States)

    Tuominen, Rainer; Engström, Pär G; Helgadottir, Hildur; Eriksson, Hanna; Unneberg, Per; Kjellqvist, Sanela; Yang, Muyi; Lindén, Diana; Edsgärd, Daniel; Hansson, Johan; Höiom, Veronica

    2016-07-01

    We applied a targeted sequencing approach to identify germline mutations conferring a moderately to highly increased risk of cutaneous and uveal melanoma. Ninety-two high-risk melanoma patients were screened for inherited variation in 120 melanoma candidate genes. Observed gene variants were filtered based on frequency in reference populations, cosegregation with melanoma in families and predicted functional effect. Several novel or rare genetic variants in genes involved in DNA damage response, cell-cycle regulation and transcriptional control were identified in melanoma patients. Among identified genetic alterations was an extremely rare variant (minor allele frequency of 0.00008) in the BRIP1 gene that was found to cosegregate with the melanoma phenotype. We also found a rare nonsense variant in the BRCA2 gene (rs11571833), previously associated with cancer susceptibility but not with melanoma, which showed weak association with melanoma susceptibility in the Swedish population. Our results add to the growing knowledge about genetic factors associated with melanoma susceptibility and also emphasize the role of DNA damage response as an important factor in melanoma etiology. © 2016 Wiley Periodicals, Inc. PMID:27074266

  16. The spectrum of BRCA1 and BRCA2 alleles in Latin America and the Caribbean: a clinical perspective.

    Science.gov (United States)

    Dutil, Julie; Golubeva, Volha A; Pacheco-Torres, Alba L; Diaz-Zabala, Hector J; Matta, Jaime L; Monteiro, Alvaro N

    2015-12-01

    Hereditary cancer predisposition gene testing allows the identification of individuals at high risk of cancer that may benefit from increased surveillance, chemoprevention, and prophylactic surgery. In order to implement clinical genetic strategies adapted to each population's needs and intrinsic genetic characteristic, this review aims to present the current status of knowledge about the spectrum of BRCA pathogenic variants in Latin American populations. We have conducted a comprehensive review of 33 studies published between 1994 and 2015 reporting the prevalence and/or spectrum of BRCA1 (OMIM 113705) and BRCA2 (OMIM 600185) variants. The combined sample size for these studies consisted of 4835 individuals from 13 countries in Latin America and the Caribbean, as well as in Hispanics in the United States. A total of 167 unique pathogenic variants have been reported in the existing literature. In unselected breast cancer cases, the prevalence ranged from 1.2 to 27.1%. Some countries presented a few recurrent pathogenic variants, while others were characterized by diverse, non-recurrent variants. The proportion of BRCA pathogenic variants shared between Hispanics in the United States and Latin American populations was estimated at 10.4%. Within Latin America and the Caribbean, 8.2% of the BRCA variants reported were present in more than one country. Countries with high prevalence of BRCA pathogenic variants may benefit from more aggressive testing strategies, while testing of recurrent variant panels might present a cost-effective solution for improving genetic testing in some, but not all, countries. PMID:26564481

  17. Comparison of risk assessment models of BRCA1 and BRCA2 mutation carrier in patients with breast cancer

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    Rybchenko L.A.

    2013-12-01

    Full Text Available Analysis of efficiency of the algorithm BOADICEA using and Manchester scoring system to predict the carrier of BRCA1 and BRCA2 mutations in Ukranian patients with breast cancer was performed. Materials for this study were the results of clinical, imunogistological, pathogistological, genealogical, molecular genetic researches of 146 patients with breast cancer. Calculations of mutations risk were performed using BOADICEA algorithm and Manchester scoring system. In the total group of patients the area under the curve while predicting BRCA1 mutations with algorithm BOADICEA was 0.86, with Manchester scoring system - 0.84, and in calculation of the combined risk of BRCA mutations - 0.83 and 0.84, respectively. However, statistical difference between the areas of algorithms has not been established (p> 0.05, it indicates to the same discriminatory power of the test models. Better sensitivity, specificity, positive and negative predictive value of results of BOADICEA algorithm was reached in 6% of BRCA1 probability and in 8% threshold of BRCA1/2 mutations. The Manchester scoring system has showed the best operating characteristics with 6 and 13-point probability of BRCA1 and BRCA1/2 mutations respectively. Patients with probability of mutations with such thresholds may be offered molecular study of pathogenic alleles.

  18. Fanconi anemia with biallelic FANCD1/BRCA2 mutations - Case report of a family with three affected children.

    Science.gov (United States)

    Svojgr, Karel; Sumerauer, David; Puchmajerova, Alena; Vicha, Ales; Hrusak, Ondrej; Michalova, Kyra; Malis, Josef; Smisek, Petr; Kyncl, Martin; Novotna, Drahuse; Machackova, Eva; Jencik, Jan; Pycha, Karel; Vaculik, Miroslav; Kodet, Roman; Stary, Jan

    2016-03-01

    Fanconi anemia, complementation group D1 with bi-allelic FANCD1 (BRCA2) mutations, is a very rare genetic disorder characterized by early onset of childhood malignancies, including acute leukemia, brain cancer and nephroblastoma. Here, we present a case report of a family with 3 affected children in terms of treatment outcome, toxicity and characterization of the malignancies using comprehensive cytogenetic analysis. The first child was diagnosed with T-cell acute lymphoblastic leukemia when he was 11 months old. During chemotherapy, he suffered from repeated pancytopenia, sepsis and severe vincristine polyneuropathy, and 18 months after primary diagnosis, he succumbed to secondary acute monocytic leukemia. The second child was diagnosed with stage 2 triphasic nephroblastoma (Wilms tumor), when he was 3 years and 11 months old. During chemotherapy, he suffered from vincristine polyneuropathy. Currently, he is in complete remission, 29 months following the initial diagnosis. The third child was diagnosed with medulloblastoma with classical histology, when she was 4 years and 5 months old. After the first cycle of chemotherapy, she suffered from prolonged pancytopenia, sepsis and severe skin and mucosal toxicity. Six weeks after primary diagnosis, a first relapse in the posterior fossa was diagnosed, and at 7 and half months after primary diagnosis, a second relapse was diagnosed that led to the patient's death. Our case report underscores tumor heterogeneity, treatment toxicity and poor outcome in Fanconi anemia patients of complementation group D1. PMID:26657402

  19. A simple method for co-segregation analysis to evaluate the pathogenicity of unclassified variants; BRCA1 and BRCA2 as an example

    Directory of Open Access Journals (Sweden)

    Gómez García Encarna

    2009-06-01

    Full Text Available Abstract Background Assessment of the clinical significance of unclassified variants (UVs identified in BRCA1 and BRCA2 is very important for genetic counselling. The analysis of co-segregation of the variant with the disease in families is a powerful tool for the classification of these variants. Statistical methods have been described in literature but these methods are not always easy to apply in a diagnostic setting. Methods We have developed an easy to use method which calculates the likelihood ratio (LR of an UV being deleterious, with penetrance as a function of age of onset, thereby avoiding the use of liability classes. The application of this algorithm is publicly available http://www.msbi.nl/cosegregation. It can easily be used in a diagnostic setting since it requires only information on gender, genotype, present age and/or age of onset for breast and/or ovarian cancer. Results We have used the algorithm to calculate the likelihood ratio in favour of causality for 3 UVs in BRCA1 (p.M18T, p.S1655F and p.R1699Q and 5 in BRCA2 (p.E462G p.Y2660D, p.R2784Q, p.R3052W and p.R3052Q. Likelihood ratios varied from 0.097 (BRCA2, p.E462G to 230.69 (BRCA2, p.Y2660D. Typing distantly related individuals with extreme phenotypes (i.e. very early onset cancer or old healthy individuals are most informative and give the strongest likelihood ratios for or against causality. Conclusion Although co-segregation analysis on itself is in most cases insufficient to prove pathogenicity of an UV, this method simplifies the use of co-segregation as one of the key features in a multifactorial approach considerably.

  20. Analysis of PALB2 Gene in BRCA1/BRCA2 Negative Spanish Hereditary Breast/Ovarian Cancer Families with Pancreatic Cancer Cases

    Science.gov (United States)

    de la Hoya, Miguel; Osorio, Ana; Diez, Orland; Miramar, María Dolores; Infante, Mar; Martinez-Bouzas, Cristina; Torres, Asunción; Lasa, Adriana; Llort, Gemma; Brunet, Joan; Graña, Begoña; Perez Segura, Pedro; Garcia, María José; Gutiérrez-Enríquez, Sara; Carracedo, Ángel; Tejada, María-Isabel; Velasco, Eladio A.; Calvo, María-Teresa; Balmaña, Judith; Benitez, Javier; Caldés, Trinidad

    2013-01-01

    Background The PALB2 gene, also known as FANCN, forms a bond and co-localizes with BRCA2 in DNA repair. Germline mutations in PALB2 have been identified in approximately 1% of familial breast cancer and 3–4% of familial pancreatic cancer. The goal of this study was to determine the prevalence of PALB2 mutations in a population of BRCA1/BRCA2 negative breast cancer patients selected from either a personal or family history of pancreatic cancer. Methods 132 non-BRCA1/BRCA2 breast/ovarian cancer families with at least one pancreatic cancer case were included in the study. PALB2 mutational analysis was performed by direct sequencing of all coding exons and intron/exon boundaries, as well as multiplex ligation-dependent probe amplification. Results Two PALB2 truncating mutations, the c.1653T>A (p.Tyr551Stop) previously reported, and c.3362del (p.Gly1121ValfsX3) which is a novel frameshift mutation, were identified. Moreover, several PALB2 variants were detected; some of them were predicted as pathological by bioinformatic analysis. Considering truncating mutations, the prevalence rate of our population of BRCA1/2-negative breast cancer patients with pancreatic cancer is 1.5%. Conclusions The prevalence rate of PALB2 mutations in non-BRCA1/BRCA2 breast/ovarian cancer families, selected from either a personal or family pancreatic cancer history, is similar to that previously described for unselected breast/ovarian cancer families. Future research directed towards identifying other gene(s) involved in the development of breast/pancreatic cancer families is required. PMID:23935836

  1. Comprehensive analysis of BRCA1, BRCA2 and TP53 germline mutation and tumor characterization: a portrait of early-onset breast cancer in Brazil.

    Directory of Open Access Journals (Sweden)

    Dirce Maria Carraro

    Full Text Available Germline mutations in BRCA1, BRCA2 and TP53 genes have been identified as one of the most important disease-causing issues in young breast cancer patients worldwide. The specific defective biological processes that trigger germline mutation-associated and -negative tumors remain unclear. To delineate an initial portrait of Brazilian early-onset breast cancer, we performed an investigation combining both germline and tumor analysis. Germline screening of the BRCA1, BRCA2, CHEK2 (c.1100delC and TP53 genes was performed in 54 unrelated patients <35 y; their tumors were investigated with respect to transcriptional and genomic profiles as well as hormonal receptors and HER2 expression/amplification. Germline mutations were detected in 12 out of 54 patients (22% [7 in BRCA1 (13%, 4 in BRCA2 (7% and one in TP53 (2% gene]. A cancer familial history was present in 31.4% of the unrelated patients, from them 43.7% were carriers for germline mutation (37.5% in BRCA1 and in 6.2% in the BRCA2 genes. Fifty percent of the unrelated patients with hormone receptor-negative tumors carried BRCA1 mutations, percentage increasing to 83% in cases with familial history of cancer. Over-representation of DNA damage-, cellular and cell cycle-related processes was detected in the up-regulated genes of BRCA1/2-associated tumors, whereas cell and embryo development-related processes were over-represented in the up-regulated genes of BRCA1/2-negative tumors, suggesting distinct mechanisms driving the tumorigenesis. An initial portrait of the early-onset breast cancer patients in Brazil was generated pointing out that hormone receptor-negative tumors and positive familial history are two major risk factors for detection of a BRCA1 germline mutation. Additionally, the data revealed molecular factors that potentially trigger the tumor development in young patients.

  2. Comprehensive analysis of BRCA1, BRCA2 and TP53 germline mutation and tumor characterization: a portrait of early-onset breast cancer in Brazil.

    Science.gov (United States)

    Carraro, Dirce Maria; Koike Folgueira, Maria Aparecida Azevedo; Garcia Lisboa, Bianca Cristina; Ribeiro Olivieri, Eloisa Helena; Vitorino Krepischi, Ana Cristina; de Carvalho, Alex Fiorini; de Carvalho Mota, Louise Danielle; Puga, Renato David; do Socorro Maciel, Maria; Michelli, Rodrigo Augusto Depieri; de Lyra, Eduardo Carneiro; Grosso, Stana Helena Giorgi; Soares, Fernando Augusto; Achatz, Maria Isabel Alves de Souza Waddington; Brentani, Helena; Moreira-Filho, Carlos Alberto; Brentani, Maria Mitzi

    2013-01-01

    Germline mutations in BRCA1, BRCA2 and TP53 genes have been identified as one of the most important disease-causing issues in young breast cancer patients worldwide. The specific defective biological processes that trigger germline mutation-associated and -negative tumors remain unclear. To delineate an initial portrait of Brazilian early-onset breast cancer, we performed an investigation combining both germline and tumor analysis. Germline screening of the BRCA1, BRCA2, CHEK2 (c.1100delC) and TP53 genes was performed in 54 unrelated patients profiles as well as hormonal receptors and HER2 expression/amplification. Germline mutations were detected in 12 out of 54 patients (22%) [7 in BRCA1 (13%), 4 in BRCA2 (7%) and one in TP53 (2%) gene]. A cancer familial history was present in 31.4% of the unrelated patients, from them 43.7% were carriers for germline mutation (37.5% in BRCA1 and in 6.2% in the BRCA2 genes). Fifty percent of the unrelated patients with hormone receptor-negative tumors carried BRCA1 mutations, percentage increasing to 83% in cases with familial history of cancer. Over-representation of DNA damage-, cellular and cell cycle-related processes was detected in the up-regulated genes of BRCA1/2-associated tumors, whereas cell and embryo development-related processes were over-represented in the up-regulated genes of BRCA1/2-negative tumors, suggesting distinct mechanisms driving the tumorigenesis. An initial portrait of the early-onset breast cancer patients in Brazil was generated pointing out that hormone receptor-negative tumors and positive familial history are two major risk factors for detection of a BRCA1 germline mutation. Additionally, the data revealed molecular factors that potentially trigger the tumor development in young patients. PMID:23469205

  3. An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers.

    OpenAIRE

    Blein, Sophie; Bardel, Claire; Danjean, Vincent; McGuffog, Lesley; Healey, Sue; Barrowdale, Daniel; Lee, Andrew; Dennis, Joe; Kuchenbaecker, Karoline B.; Soucy, Penny; Terry, Mary Beth; Chung, Wendy K.; Goldgar, David E; Buys, Saundra S.; Janavicius, Ramunas

    2015-01-01

    Individuals carrying pathogenic mutations in BRCA1/2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals from different mitochondrial haplogroups differ in their metabolism and sensitivity to ...

  4. Common variants in LSP1, 2q35 and 8q24 and breast cancer risk for BRCA1 and BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Antoniou, A.C.; Sinilnikova, O.M.; McGuffog, L.;

    2009-01-01

    Genome-wide association studies of breast cancer have identified multiple single nucleotide polymorphisms (SNPs) that are associated with increased breast cancer risks in the general population. In a previous study, we demonstrated that the minor alleles at three of these SNPs, in FGFR2, TNRC9...... and MAP3K1, also confer increased risks of breast cancer for BRCA1 or BRCA2 mutation carriers. Three additional SNPs rs3817198 at LSP1, rs13387042 at 2q35 and rs13281615 at 8q24 have since been reported to be associated with breast cancer in the general population, and in this study we evaluated...... their association with breast cancer risk in 9442 BRCA1 and 5665 BRCA2 mutation carriers from 33 study centres. The minor allele of rs3817198 was associated with increased breast cancer risk only for BRCA2 mutation carriers [hazard ratio (HR) = 1.16, 95% CI: 1.07-1.25, P-trend = 2.8 x 10(-4)]. The best fit...

  5. BRCA1 and BRCA2 germline mutation analysis among Indian women from south India: identification of four novel mutations and high-frequency occurrence of 185delAG mutation

    Indian Academy of Sciences (India)

    Kannan Vaidyanathan; Smita Lakhotia; H M Ravishankar; Umaira Tabassum; Geetashree Mukherjee; Kumaravel Somasundaram

    2009-09-01

    Mutations in the BRCA1 and BRCA2 genes profoundly increase the risk of developing breast and/or ovarian cancer among women. To explore the contribution of BRCA1 and BRCA2 mutations in the development of hereditary breast cancer among Indian women, we carried out mutation analysis of the BRCA1 and BRCA2 genes in 61 breast or ovarian cancer patients from south India with a positive family history of breast and/or ovarian cancer. Mutation analysis was carried out using conformation-sensitive gel electrophoresis (CSGE) followed by sequencing. Mutations were identified in 17 patients (28.0%); 15 (24.6%) had BRCA1 mutations and two (3.28%) had BRCA2 mutations. While no specific association between BRCA1 or BRCA2 mutations with cancer type was seen, mutations were more often seen in families with ovarian cancer. While 40% (4/10) and 30.8% (4/12) of families with ovarian or breast and ovarian cancer had mutations, only 23.1% (9/39) of families with breast cancer carried mutations in the BRCA1 and BRCA2 genes. In addition, while BRCA1 mutations were found in all age groups, BRCA2 mutations were found only in the age group of ≤ 40 years. Of the BRCA1 mutations, there were three novel mutations (295delCA; 4213T → A; 5267T → G) and three mutations that have been reported earlier. Interestingly, 185delAG, a BRCA1 mutation which occurs at a very high frequency in Ashkenazi Jews, was found at a frequency of 16.4% (10/61). There was one novel mutation (4866insT) and one reported mutation in BRCA2. Thus, our study emphasizes the importance of mutation screening in familial breast and/or ovarian cancers, and the potential implications of these findings in genetic counselling and preventive therapy.

  6. Spectrum and characterisation of BRCA1 and BRCA2 deleterious mutations in high-risk Czech patients with breast and/or ovarian cancer

    Directory of Open Access Journals (Sweden)

    Kosinova Veronika

    2008-05-01

    Full Text Available Abstract Background The incidence of breast cancer has doubled over the past 20 years in the Czech Republic. Hereditary factors may be a cause of young onset, bilateral breast or ovarian cancer, and familial accumulation of the disease. BRCA1 and BRCA2 mutations account for an important fraction of hereditary breast and ovarian cancer cases. One thousand and ten unrelated high-risk probands with breast and/or ovarian cancer were analysed for the presence of a BRCA1 or BRCA2 gene mutation at the Masaryk Memorial Cancer Institute (Czech Republic during 1999–2006. Methods The complete coding sequences and splice sites of both genes were screened, and the presence of large intragenic rearrangements in BRCA1 was verified. Putative splice-site variants were analysed at the cDNA level for their potential to alter mRNA splicing. Results In 294 unrelated families (29.1% of the 1,010 probands pathogenic mutations were identified, with 44 different BRCA1 mutations and 41 different BRCA2 mutations being detected in 204 and 90 unrelated families, respectively. In total, three BRCA1 founder mutations (c.5266dupC; c.3700_3704del5; p.Cys61Gly and two BRCA2 founder mutations (c.7913_7917del5; c.8537_8538del2 represent 52% of all detected mutations in Czech high-risk probands. Nine putative splice-site variants were evaluated at the cDNA level. Three splice-site variants in BRCA1 (c.302-3C>G; c.4185G>A and c.4675+1G>A and six splice-site variants in BRCA2 (c.475G>A; c.476-2>G; c.7007G>A; c.8755-1G>A; c.9117+2T>A and c.9118-2A>G were demonstrated to result in aberrant transcripts and are considered as deleterious mutations. Conclusion This study represents an evaluation of deleterious genetic variants in the BRCA1 and 2 genes in the Czech population. The classification of several splice-site variants as true pathogenic mutations may prove useful for genetic counselling of families with high risk of breast and ovarian cancer.

  7. Haplotype analysis of TP53 polymorphisms, Arg72Pro and Ins16, in BRCA1 and BRCA2 mutation carriers of French Canadian descent

    International Nuclear Information System (INIS)

    The TP53 polymorphisms Arg72Pro (Ex4+199 G>C) and Ins16 (IVS3+24 ins16) have been proposed to modify risk of breast cancer associated with germline BRCA1 and BRCA2 mutations. Allele frequencies of these polymorphisms were investigated to determine if they modify risk in BRCA mutation carriers in breast cancer cases drawn from French Canadian cancer families, a population shown to exhibit strong founder effects. The frequencies of the TP53 alleles, genotypes and haplotypes of 157 index breast cancer cases comprised of 42 BRCA1 mutation carriers, 57 BRCA2 mutation carriers, and 58 BRCA mutation-negative cases, where each case was drawn from independently ascertained families were compared. The effect of TP53 variants on the age of diagnosis was also investigated for these groups. The TP53 polymorphisms were also investigated in 112 women of French Canadian descent with no personal history of cancer. The BRCA mutation-positive groups had the highest frequency of homozygous carriers of the 72Pro allele compared with mutation-negative group. The TP53 polymorphisms exhibited linkage disequilibrium (p < 0.001), where the 72Arg and Ins16minus alleles occurred in strong disequilibrium. The highest frequency of carriers of Ins16minus-72Arg haplotype occurred in the BRCA mutation-negative groups. The BRCA1 mutation carriers homozygous for the 72Pro allele had the youngest ages of diagnosis of breast cancer. However none of these observations were statistically significant. In contrast, the BRCA2 mutation carriers homozygous for the 72Pro allele had a significantly older age of diagnosis of breast cancer (p = 0.018). Moreover, in this group, the mean age of diagnosis of breast cancer in carriers of the Ins16minus-72Arg haplotype was significantly younger than that of the individuals who did not this carry this haplotype (p = 0.009). We observed no significant association of breast cancer risk with TP53 genetic variants based on BRCA1/2 mutation carrier status. Although the

  8. Risk factors for endometrial cancer among women with a BRCA1 or BRCA2 mutation: a case control study.

    Science.gov (United States)

    Segev, Yakir; Rosen, Barry; Lubinski, Jan; Gronwald, Jacek; Lynch, Henry T; Moller, Pal; Kim-Sing, Charmaine; Ghadirian, Parviz; Karlan, Beth; Eng, Charis; Gilchrist, Dawna; Neuhausen, Susan L; Eisen, Andrea; Friedman, Eitan; Euhus, David; Ping, Sun; Narod, Steven A

    2015-09-01

    BRCA mutation carriers may use tamoxifen for breast cancer prevention or treatment. Hormone replacement therapy is often prescribed after surgical menopause and oral contraceptives are recommended for ovarian cancer prevention. The objective of this study was to assess the impact of these medications and other risk factors on endometrial cancer risk in BRCA carriers. Women with a BRCA1 or BRCA2 mutation were identified from a registry of mutation carriers. Cases were 83 women who had a diagnosis of endometrial cancer. Controls were 1027 matched women who did not develop endometrial cancer and who had an intact uterus. All women completed a baseline questionnaire, which included questions about ages at menarche and menopause, oral contraceptive use, hormone replacement therapy use, hysterectomy, oophorectomy, breast cancer history and tamoxifen use. We estimated the odds ratio associated with each risk factor in a multivariate analysis. No differences were found between cases and controls in terms of age at menarche, BMI, smoking, or oral contraceptive use. In a multivariate analysis, for women taking estrogen-only hormone replacement therapy, the odds ratio was 0.23 (95% CI 0.03-1.78, p = 0.16), and for women taking progesterone-only hormone replacement therapy the odds ratio was 6.91 (95% CI 0.99-98.1, p = 0.05). The adjusted odds ratio for endometrial cancer associated with a history of tamoxifen use was 3.50 (95% CI 1.51-8.10, p = 0.003). The observed increased risk of endometrial cancer associated with progesterone-only therapy merits further study. PMID:25838159

  9. Mediating Structures in Sámi Language Revitalisation

    OpenAIRE

    Sarivaara, Erika; Keskitalo, Pigga

    2016-01-01

    The revitalisation of the Sámi languages and support for language domains are central educational measures in the post-assimilation situation in Northern Europe. Taking critical indigenous education as the starting point, this metatheoretical article discusses language revitalisation through mediating structures. Mediating structures provide the tools necessary to use language revitalisation as a means to counter the legacy of assimilation that has seriously affected the Sámi languages and ca...

  10. Mediating Structures in Sámi Language Revitalisation

    OpenAIRE

    Erika Sarivaara; Pigga Keskitalo

    2016-01-01

    The revitalisation of the Sámi languages and support for language domains are central educational measures in the post-assimilation situation in Northern Europe. Taking critical indigenous education as the starting point, this meta-theoretical article discusses language revitalisation through mediating structures. Mediating structures provide the tools necessary to use language revitalisation as a means to counter the legacy of assimilation that has seriously affected the Sámi languages and c...

  11. 中国汉族人群中BRCA1和BRCA2基因突变携带者患乳腺癌风险的研究%Breast cancer risk in BRCA1 and BRCA2 mutation carriers in Chinese Han population

    Institute of Scientific and Technical Information of China (English)

    杨晓晨; 胡震; 吴炅; 柳光宇; 沈镇宙; 邵志敏

    2015-01-01

    背景与目的:BRCA1和BRCA2基因突变携带者终生患乳腺癌和卵巢癌的风险显著增高。通过遗传咨询,突变携带者可采取适当的措施来降低相应肿瘤的发生风险。目前,相关的报道几乎均为白种人,尚缺乏中国人群的资料。该研究旨在探索中国汉族人群中BRCA1和BRCA2基因突变携带者患乳腺癌的风险。方法:回顾20个经基因检测证实携带BRCA1或BRCA2致病性基因突变的汉族乳腺癌高风险家系。利用Kaplan-Meier生存分析法对女性BRCA1/2基因突变携带者单侧乳腺癌及对侧乳腺癌的累积发病风险进行估算。结果:BRCA1和BRCA2基因突变携带者70岁时单侧乳腺癌的累积发病风险(外显率)分别为67.2%(sx 0.100)和76.8%(sx 0.079)。与BRCA1不同的是,BRCA2基因突变携带者70岁后乳腺癌累积发病率继续增加,到80岁时达93.1%。BRCA1/2基因突变携带者对侧乳腺癌10年和20年的累积发病率分别为19.4%(sx 0.089)和50.3%(sx 0.155)。结论:中国汉族人群中BRCA1和BRCA2基因突变携带者具有很高的乳腺癌发病风险。因而对中国高风险人群进行BRCA1/2基因突变检测具有重要临床意义。%Background and purpose: BRCA1 and BRCA2 mutation carriers have a high lifetime risk of developing breast and ovarian cancer. Through genetic counseling, mutation carriers can take the appropriate measures to reduce such cancer risk. At present, almost all related studies were conducted in Caucasian, while, the studies in Chinese population were rare. This study aimed to investigate the risk of breast cancer in BRCA1 and BRCA2 mutation carriers in Chinese Han population. Methods:Twenty unrelated families with BRCA1 or BRCA2 mutations were re-viewed. Kaplan-Meier analyses were used to estimate the cumulative risks of unilateral breast cancer and contralateral breast cancer for female BRCA1 and BRCA2 mutation carriers. Results:Breast cancer risk to 70 years (penetrance) was 67

  12. Prospective Study of Breast Cancer Incidence in Women With a BRCA1 or BRCA2 Mutation Under Surveillance With and Without Magnetic Resonance Imaging

    Science.gov (United States)

    Warner, Ellen; Hill, Kimberley; Causer, Petrina; Plewes, Donald; Jong, Roberta; Yaffe, Martin; Foulkes, William D.; Ghadirian, Parviz; Lynch, Henry; Couch, Fergus; Wong, John; Wright, Frances; Sun, Ping; Narod, Steven A.

    2011-01-01

    Purpose The sensitivity of magnetic resonance imaging (MRI) for breast cancer screening exceeds that of mammography. If MRI screening reduces mortality in women with a BRCA1 or BRCA2 mutation, it is expected that the incidence of advanced-stage breast cancers should be reduced in women undergoing MRI screening compared with those undergoing conventional screening. Patients and Methods We followed 1,275 women with a BRCA1 or BRCA2 mutation for a mean of 3.2 years. In total, 445 women were enrolled in an MRI screening trial in Toronto, Ontario, Canada, and 830 were in the comparison group. The cumulative incidences of ductal carcinoma in situ (DCIS), early-stage, and late-stage breast cancers were estimated at 6 years in the cohorts. Results There were 41 cases of breast cancer in the MRI-screened cohort (9.2%) and 76 cases in the comparison group (9.2%). The cumulative incidence of DCIS or stage I breast cancer at 6 years was 13.8% (95% CI, 9.1% to 18.5%) in the MRI-screened cohort and 7.2% (95% CI, 4.5% to 9.9%) in the comparison group (P = .01). The cumulative incidence of stages II to IV breast cancers was 1.9% (95% CI, 0.2% to 3.7%) in the MRI-screened cohort and 6.6% (95% CI, 3.8% to 9.3%) in the comparison group (P = .02). The adjusted hazard ratio for the development of stages II to IV breast cancer associated with MRI screening was 0.30 (95% CI, 0.12 to 0.72; P = .008). Conclusion Annual surveillance with MRI is associated with a significant reduction in the incidence of advanced-stage breast cancer in BRCA1 and BRCA2 carriers. PMID:21444874

  13. A prospective investigation of predictive and modifiable risk factors for breast cancer in unaffected BRCA1 and BRCA2 gene carriers

    International Nuclear Information System (INIS)

    Breast cancer is the most common female cancer worldwide. The lifetime risk of a woman being diagnosed with breast cancer is approximately 12.5%. For women who carry the deleterious mutation in either of the BRCA genes, BRCA1 or BRCA2, the risk of developing breast or ovarian cancer is significantly increased. In recent years there has been increased penetrance of BRCA1 and BRCA2 associated breast cancer, prompting investigation into the role of modifiable risk factors in this group. Previous investigations into this topic have relied on participants recalling lifetime weight changes and subjective methods of recording physical activity. The influence of obesity-related biomarkers, which may explain the link between obesity, physical activity and breast cancer risk, has not been investigated prospectively in this group. This paper describes the design of a prospective cohort study investigating the role of predictive and modifiable risk factors for breast cancer in unaffected BRCA1 and BRCA2 gene mutation carriers. Participants will be recruited from breast cancer family risk clinics and genetics clinics. Lifestyle risk factors that will be investigated will include body composition, metabolic syndrome and its components, physical activity and dietary intake. PBMC telomere length will be measured as a potential predictor of breast cancer occurrence. Measurements will be completed on entry to the study and repeated at two years and five years. Participants will also be followed annually by questionnaire to track changes in risk factor status and to record cancer occurrence. Data will be analysed using multiple regression models. The study has an accrual target of 352 participants. The results from this study will provide valuable information regarding the role of modifiable lifestyle risk factors for breast cancer in women with a deleterious mutation in the BRCA gene. Additionally, the study will attempt to identify potential blood biomarkers which may be predictive

  14. Whole exome sequencing suggests much of non-BRCA1/BRCA2 familial breast cancer is due to moderate and low penetrance susceptibility alleles.

    Directory of Open Access Journals (Sweden)

    Francisco Javier Gracia-Aznarez

    Full Text Available The identification of the two most prevalent susceptibility genes in breast cancer, BRCA1 and BRCA2, was the beginning of a sustained effort to uncover new genes explaining the missing heritability in this disease. Today, additional high, moderate and low penetrance genes have been identified in breast cancer, such as P53, PTEN, STK11, PALB2 or ATM, globally accounting for around 35 percent of the familial cases. In the present study we used massively parallel sequencing to analyze 7 BRCA1/BRCA2 negative families, each having at least 6 affected women with breast cancer (between 6 and 10 diagnosed under the age of 60 across generations. After extensive filtering, Sanger sequencing validation and co-segregation studies, variants were prioritized through either control-population studies, including up to 750 healthy individuals, or case-control assays comprising approximately 5300 samples. As a result, a known moderate susceptibility indel variant (CHEK2 1100delC and a catalogue of 11 rare variants presenting signs of association with breast cancer were identified. All the affected genes are involved in important cellular mechanisms like DNA repair, cell proliferation and survival or cell cycle regulation. This study highlights the need to investigate the role of rare variants in familial cancer development by means of novel high throughput analysis strategies optimized for genetically heterogeneous scenarios. Even considering the intrinsic limitations of exome resequencing studies, our findings support the hypothesis that the majority of non-BRCA1/BRCA2 breast cancer families might be explained by the action of moderate and/or low penetrance susceptibility alleles.

  15. Large genomic rearrangements of BRCA1 and BRCA2 among patients referred for genetic analysis in Galicia (NW Spain): delimitation and mechanism of three novel BRCA1 rearrangements.

    Science.gov (United States)

    Fachal, Laura; Blanco, Ana; Santamariña, Marta; Carracedo, Angel; Vega, Ana

    2014-01-01

    In the Iberian Peninsula, which includes mainly Spain and Portugal, large genomic rearrangements (LGRs) of BRCA1 and BRCA2 have respectively been found in up to 2.33% and 8.4% of families with hereditary breast and/or ovarian cancer (HBOC) that lack point mutations and small indels. In Galicia (Northwest Spain), the spectrum and frequency of BRCA1/BRCA2 point mutations differs from the rest of the Iberian populations. However, to date there are no Galician frequency reports of BRCA1/BRCA2 LGRs. Here we used multiplex ligation-dependent probe amplification (MLPA) to screen 651 Galician index cases (out of the 830 individuals referred for genetic analysis) without point mutations or small indels. We identified three different BRCA1 LGRs in four families. Two of them have been previously classified as pathogenic LGRs: the complete deletion of BRCA1 (identified in two unrelated families) and the deletion of exons 1 to 13. We also identified the duplication of exons 1 and 2 that is a LGR with unknown pathogenicity. Determination of the breakpoints of the BRCA1 LGRs using CNV/SNP arrays and sequencing identified them as NG_005905.2:g.70536_180359del, NG_005905.2:g.90012_97270dup, and NC_000017.10:g.41230935_41399840delinsAluSx1, respectively; previous observations of BRCA1 exon1-24del, exon1-2dup, and exon1-13del LGRs have not characterized them in such detail. All the BRCA1 LGRs arose from unequal homologous recombination events involving Alu elements. We also detected, by sequencing, one BRCA2 LGR, the Portuguese founder mutation c.156_157insAluYa5. The low frequency of BRCA1 LGRs within BRCA1 mutation carriers in Galicia (2.34%, 95% CI: 0.61-7.22) seems to differ from the Spanish population (9.93%, 95% CI: 6.76-14.27, P-value = 0.013) and from the rest of the Iberian population (9.76%, 95% CI: 6.69-13.94, P-value = 0.014). PMID:24686251

  16. Long-term outcomes of breast cancer in women aged 30 years or younger, based on family history, pathology and BRCA1/BRCA2/TP53 status

    OpenAIRE

    Evans, D G R; Moran, A.; R Hartley; Dawson, J; Bulman, B.; Knox, F; Howell, A.; Lalloo, F

    2010-01-01

    Background: There are relatively few articles addressing long-term follow-up in women with breast cancer at very young ages. Methods: We have updated and extended our population-based analysis of breast cancer diagnosed at the age ⩽30 years in North-west England to include an extra 15 patients with mutation testing in BRCA1, BRCA2 and TP53, with 115 of 288 consecutive cases being tested. Kaplan–Meier curves were generated to assess overall survival, contralateral breast cancer and other secon...

  17. Haplotype analysis suggest common founders in carriers of the recurrent BRCA2 mutation, 3398delAAAAG, in French Canadian hereditary breast and/ovarian cancer families

    Directory of Open Access Journals (Sweden)

    Foulkes William D

    2006-03-01

    Full Text Available Abstract Background The 3398delAAAAG mutation in BRCA2 was recently found to recur in breast and/or ovarian cancer families from the French Canadian population of Quebec, a population that has genetic attributes consistent with a founder effect. To characterize the contribution of this mutation in this population, this study established the frequency of this mutation in breast and ovarian cancer cases unselected for family history of cancer, and determined if mutation carriers shared a common ancestry. Methods The frequency was estimated by assaying the mutation in series of French Canadian breast cancer cases diagnosed before age 41 (n = 60 or 80 (n = 127 years of age, and ovarian cancer cases (n = 80 unselected for family history of cancer by mutation analysis. Haplotype analysis was performed to determine if mutation carriers shared a common ancestry. Members from 11 families were analyzed using six polymorphic microsatellite markers (cen-D13S260-D13S1699-D13S1698-D13S1697-D13S1701-D13S171-tel spanning approximately a 3.6 cM interval at the chromosomal region 13q13.1, which contains BRCA2. Allele frequencies were estimated by genotyping 47 unaffected female individuals derived from the same population. Haplotype reconstruction of unaffected individuals was performed using the program PHASE. Results The recurrent BRCA2 mutation occurred in 1 of 60 (1.7% women diagnosed with breast cancer before 41 years of age and one of 80 (1.3% women with ovarian cancer. No mutation carriers were identified in the series of breast cancer cases diagnosed before age 80. Mutation carriers harboured one of two haplotypes, 7-3-9-3 – [3/4]-7, that varied with marker D13S1701 and which occurred at a frequency of 0.001. The genetic analysis of D13S1695, a polymorphic marker located approximately 0.3 cM distal to D13S171, did not favour a genetic recombination event to account for the differences in D13S1701 alleles within the haplotype. Although mutation carriers

  18. DCIS in BRCA1 and BRCA2 mutation carriers: prevalence, phenotype, and expression of oncodrivers C-MET and HER3

    OpenAIRE

    Yang, Rachel L.; Mick, Rosemarie; Lee, Kathreen; Holly L Graves; Nathanson, Katherine L.; Domchek, Susan M.; Kelz, Rachel R; Zhang, Paul J; Czerniecki, Brian J.

    2015-01-01

    Background Studies report conflicting evidence regarding the existence of a DCIS-associated premalignant pathway in BRCA mutation carriers. We aimed to examine the prevalence, phenotype, and expression of oncodrivers in pure DCIS (pDCIS) and invasive breast cancer with concurrent DCIS (IBC + DCIS) in mutation carriers. Methods A cohort of BRCA1 and BRCA2 mutation carriers >18 years old who underwent surgery for breast cancer at an academic hospital (1992–2011) and had pathology available for ...

  19. Water-mediated ionic interactions in protein structures

    Indian Academy of Sciences (India)

    R Sabarinathan; K Aishwarya; R Sarani; M Kirti Vaishnavi; K Sekar

    2011-06-01

    It is well known that water molecules play an indispensable role in the structure and function of biological macromolecules. The water-mediated ionic interactions between the charged residues provide stability and plasticity and in turn address the function of the protein structures. Thus, this study specifically addresses the number of possible water-mediated ionic interactions, their occurrence, distribution and nature found in 90% non-redundant protein chains. Further, it provides a statistical report of different charged residue pairs that are mediated by surface or buried water molecules to form the interactions. Also, it discusses its contributions in stabilizing various secondary structural elements of the protein. Thus, the present study shows the ubiquitous nature of the interactions that imparts plasticity and flexibility to a protein molecule.

  20. Multifactorial likelihood assessment of BRCA1 and BRCA2 missense variants confirms that BRCA1:c.122A>G(p.His41Arg is a pathogenic mutation.

    Directory of Open Access Journals (Sweden)

    Phillip J Whiley

    Full Text Available Rare exonic, non-truncating variants in known cancer susceptibility genes such as BRCA1 and BRCA2 are problematic for genetic counseling and clinical management of relevant families. This study used multifactorial likelihood analysis and/or bioinformatically-directed mRNA assays to assess pathogenicity of 19 BRCA1 or BRCA2 variants identified following patient referral to clinical genetic services. Two variants were considered to be pathogenic (Class 5. BRCA1:c.4484G> C(p.Arg1495Thr was shown to result in aberrant mRNA transcripts predicted to encode truncated proteins. The BRCA1:c.122A>G(p.His41Arg RING-domain variant was found from multifactorial likelihood analysis to have a posterior probability of pathogenicity of 0.995, a result consistent with existing protein functional assay data indicating lost BARD1 binding and ubiquitin ligase activity. Of the remaining variants, seven were determined to be not clinically significant (Class 1, nine were likely not pathogenic (Class 2, and one was uncertain (Class 3.These results have implications for genetic counseling and medical management of families carrying these specific variants. They also provide additional multifactorial likelihood variant classifications as reference to evaluate the sensitivity and specificity of bioinformatic prediction tools and/or functional assay data in future studies.

  1. Small-molecule inhibitors identify the RAD52-ssDNA interaction as critical for recovery from replication stress and for survival of BRCA2 deficient cells

    Science.gov (United States)

    Hengel, Sarah R; Malacaria, Eva; Folly da Silva Constantino, Laura; Bain, Fletcher E; Diaz, Andrea; Koch, Brandon G; Yu, Liping; Wu, Meng; Pichierri, Pietro; Spies, M Ashley; Spies, Maria

    2016-01-01

    The DNA repair protein RAD52 is an emerging therapeutic target of high importance for BRCA-deficient tumors. Depletion of RAD52 is synthetically lethal with defects in tumor suppressors BRCA1, BRCA2 and PALB2. RAD52 also participates in the recovery of the stalled replication forks. Anticipating that ssDNA binding activity underlies the RAD52 cellular functions, we carried out a high throughput screening campaign to identify compounds that disrupt the RAD52-ssDNA interaction. Lead compounds were confirmed as RAD52 inhibitors in biochemical assays. Computational analysis predicted that these inhibitors bind within the ssDNA-binding groove of the RAD52 oligomeric ring. The nature of the inhibitor-RAD52 complex was validated through an in silico screening campaign, culminating in the discovery of an additional RAD52 inhibitor. Cellular studies with our inhibitors showed that the RAD52-ssDNA interaction enables its function at stalled replication forks, and that the inhibition of RAD52-ssDNA binding acts additively with BRCA2 or MUS81 depletion in cell killing. DOI: http://dx.doi.org/10.7554/eLife.14740.001 PMID:27434671

  2. Rad18 is required for functional interactions between FANCD2, BRCA2, and Rad51 to repair DNA topoisomerase 1-poisons induced lesions and promote fork recovery

    Science.gov (United States)

    Tripathi, Kaushlendra; Mani, Chinnadurai; Clark, David W; Palle, Komaraiah

    2016-01-01

    Camptothecin (CPT) and its analogues are chemotherapeutic agents that covalently and reversibly link DNA Topoisomerase I to its nicked DNA intermediate eliciting the formation of DNA double strand breaks (DSB) during replication. The repair of these DSB involves multiple DNA damage response and repair proteins. Here we demonstrate that CPT-induced DNA damage promotes functional interactions between BRCA2, FANCD2, Rad18, and Rad51 to repair the replication-associated DSB through homologous recombination (HR). Loss of any of these proteins leads to equal disruption of HR repair, causes chromosomal aberrations and sensitizes cells to CPT. Rad18 appears to function upstream in this repair pathway as its downregulation prevents activation of FANCD2, diminishes BRCA2 and Rad51 protein levels, formation of nuclear foci of all three proteins and recovery of stalled or collapsed replication forks in response to CPT. Taken together this work further elucidates the complex interplay of DNA repair proteins in the repair of replication-associated DSB. PMID:26871286

  3. Molecular Component Structures Mediated Formation of Self-assemblies

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Molecular recognition directed self-assemblies from complementary molecular components, melamine and barbituric acid derivatives were studied by means of NMR, fluorescence, and TEM. It was found that both the process of the self-assembly and the morphologies of the result ed self-assemblies could be mediated by modifying the structures of the molecular components used. The effect of the structures of the molecular components on the formation of the self-as semblies was discussed in terms of intermolecular interactions.

  4. A nucleoside anticancer drug, 1-(3-C-ethynyl-β-D-ribo-pentofuranosylcytosine (TAS106, sensitizes cells to radiation by suppressing BRCA2 expression

    Directory of Open Access Journals (Sweden)

    Fukushima Masakazu

    2011-07-01

    Full Text Available Abstract Background A novel anticancer drug 1-(3-C-ethynyl-β-D-ribo-pentofuranosylcytosine (ECyd, TAS106 has been shown to radiosensitize tumor cells and to improve the therapeutic efficiency of X-irradiation. However, the effect of TAS106 on cellular DNA repair capacity has not been elucidated. Our aim in this study was to examine whether TAS106 modified the repair capacity of DNA double-strand breaks (DSBs in tumor cells. Methods Various cultured cell lines treated with TAS106 were irradiated and then survival fraction was examined by the clonogenic survival assays. Repair of sublethal damage (SLD, which indicates DSBs repair capacity, was measured as an increase of surviving cells after split dose irradiation with an interval of incubation. To assess the effect of TAS106 on the DSBs repair activity, the time courses of γ-H2AX and 53BP1 foci formation were examined by using immunocytochemistry. The expression of DNA-repair-related proteins was also examined by Western blot analysis and semi-quantitative RT-PCR analysis. Results In clonogenic survival assays, pretreatment of TAS106 showed radiosensitizing effects in various cell lines. TAS106 inhibited SLD repair and delayed the disappearance of γ-H2AX and 53BP1 foci, suggesting that DSB repair occurred in A549 cells. Western blot analysis demonstrated that TAS106 down-regulated the expression of BRCA2 and Rad51, which are known as keys among DNA repair proteins in the homologous recombination (HR pathway. Although a significant radiosensitizing effect of TAS106 was observed in the parental V79 cells, pretreatment with TAS106 did not induce any radiosensitizing effects in BRCA2-deficient V-C8 cells. Conclusions Our results indicate that TAS106 induces the down-regulation of BRCA2 and the subsequent abrogation of the HR pathway, leading to a radiosensitizing effect. Therefore, this study suggests that inhibition of the HR pathway may be useful to improve the therapeutic efficiency of

  5. A screen for germline mutations in the gene encoding CCCTC-binding factor (CTCF) in familial non-BRCA1/BRCA2 breast cancer

    International Nuclear Information System (INIS)

    The CCCTC-binding factor (CTCF), known as a versatile transcription factor and chromatin insulator and to be involved in X inactivation, has also been suggested to be a tumour suppressor on 16q. We investigated 153 patients with familial non-BRCA1/BRCA2 breast cancer for germline mutations in the CTCF gene. Mutation screening of CTCF was performed by denaturing high-performance liquid chromatography followed by cycle sequencing. We found two sequence variants, 240G→A in the 5' untranslated region and 1455C→T (S388S) in exon 4, in five familial breast cancer cases. Three of these five cases had both variants. Cases and controls showed the same prevalence for the two variants, which were found in linkage disequilibrium in most cases and controls. The present study suggests that germline mutations in CTCF are not important as a risk factor for breast cancer

  6. IMPLICATION DE CERTAINES MUTATIONS DANS LES GENES BRCA1 ET BRCA2 SUR LA PRÉDISPOSITION AU CANCER DU SEIN ET AU CANCER OVARIEN

    Directory of Open Access Journals (Sweden)

    Lucian Negura

    2007-08-01

    Full Text Available Le cancer du sein, ainsi que celui ovarien, est une maladie fréquente chez les femmes, ayant un traitement assez difficile et, malheureusement, de sérieuses répercutions sur le physique ; c’est pourquoi il s’avère essentiel que la maladie soit dépistée dès les phases précoces. La prédisposition génétique est responsable de 5% des cancers et de 25% des cas apparus avant l’age de 30 ans [Breast Cancer Linkage Consortium, 1997]. Nous présentons ici l’implication des gènes suppresseurs des tumeurs BRCA1 et BRCA2 sur cette prédisposition.

  7. Common variants at the 19p13.1 and ZNF365 loci are associated with ER subtypes of breast cancer and ovarian cancer risk in BRCA1 and BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Couch, Fergus J; Gaudet, Mia M; Antoniou, Antonis C;

    2012-01-01

    Genome-wide association studies (GWAS) identified variants at 19p13.1 and ZNF365 (10q21.2) as risk factors for breast cancer among BRCA1 and BRCA2 mutation carriers, respectively. We explored associations with ovarian cancer and with breast cancer by tumor histopathology for these variants in mut...

  8. Common variants at 12p11, 12q24, 9p21, 9q31.2 and in ZNF365 are associated with breast cancer risk for BRCA1 and/or BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Antoniou, Antonis C; Kuchenbaecker, Karoline B; Soucy, Penny;

    2012-01-01

    Several common alleles have been shown to be associated with breast and/or ovarian cancer risk for BRCA1 and BRCA2 mutation carriers. Recent genome-wide association studies of breast cancer have identified eight additional breast cancer susceptibility loci: rs1011970 (9p21, CDKN2A/B), rs10995190 ...

  9. Common variants at 12p11, 12q24, 9p21, 9q31.2 and in ZNF365 are associated with breast cancer risk for BRCA1 and/or BRCA2 mutation carriers

    NARCIS (Netherlands)

    Antoniou, A.C.; Kuchenbaecker, K.B.; Soucy, P.; Beesley, J.; Chen, X.; McGuffog, L.; Lee, A.; Barrowdale, D.; Healey, S.; Sinilnikova, O.M.; Caligo, M.A.; Loman, N.; Harbst, K.; Lindblom, A.; Arver, B.; Rosenquist, R.; Karlsson, P.; Nathanson, K.; Domchek, S.; Rebbeck, T.; Jakubowska, A.; Lubinski, J.; Jaworska, K.; Durda, K.; Zlowowcka-Perlowska, E.; Osorio, A.; Duran, M.; Andres, R.; Benitez, J.; Hamann, U.; Hogervorst, F.B.; Os, T.A. van; Verhoef, S.; Meijers-Heijboer, H.E.; Wijnen, J.; Gomez Garcia, E.B.; Ligtenberg, M.J.L.; Kriege, M.; Collee, J.M.; Ausems, M.G.; Oosterwijk, J.C.; Peock, S.; Frost, D.; Ellis, S.D.; Platte, R.; Fineberg, E.; Evans, D.G.; Lalloo, F.; Jacobs, C.; Eeles, R.; Adlard, J.; Davidson, R.; Cole, T.; Cook, J.; Paterson, J.; Douglas, F.; Brewer, C.; Hodgson, S.; Morrison, P.J.; Walker, L.; Rogers, M.T.; Donaldson, A.; Dorkins, H.; Godwin, A.K.; Bove, B.; Stoppa-Lyonnet, D.; Houdayer, C.; Buecher, B.; Pauw, A. de; Mazoyer, S.; Calender, A.; Leone, M.; Bressac-de Paillerets, B.; Caron, O.; Sobol, H.; Frenay, M.; Prieur, F.; Ferrer, S.U.; Mortemousque, I.; Buys, S.; Daly, M.; Miron, A.; Terry, M.U.; Hopper, J.L.; John, E.M.; Southey, M.; Goldgar, D.; Singer, C.F.; Fink-Retter, A.; Tea, M.K.; Kaulich, D.U.; Hansen, T.V.; Nielsen, F.C.; Barkardottir, R.B.; Gaudet, M.; Kirchhoff, T.; Joseph, V.; Dutra-Clarke, A.; Offit, K.; Piedmonte, M., et al.

    2012-01-01

    INTRODUCTION: Several common alleles have been shown to be associated with breast and/or ovarian cancer risk for BRCA1 and BRCA2 mutation carriers. Recent genome-wide association studies of breast cancer have identified eight additional breast cancer susceptibility loci: rs1011970 (9p21, CDKN2A/B),

  10. Common variants at 12p11, 12q24, 9p21, 9q31.2 and in ZNF365 are associated with breast cancer risk for BRCA1 and/or BRCA2 mutation carriers

    NARCIS (Netherlands)

    Antoniou, Antonis C.; Kuchenbaecker, Karoline B.; Soucy, Penny; Beesley, Jonathan; Chen, Xiaoqing; McGuffog, Lesley; Lee, Andrew; Barrowdale, Daniel; Healey, Sue; Sinilnikova, Olga M.; Caligo, Maria A.; Loman, Niklas; Harbst, Katja; Lindblom, Annika; Arver, Brita; Rosenquist, Richard; Karlsson, Per; Nathanson, Kate; Domchek, Susan; Rebbeck, Tim; Jakubowska, Anna; Lubinski, Jan; Jaworska, Katarzyna; Durda, Katarzyna; Zlowowcka-Perlowska, Elzbieta; Osorio, Ana; Duran, Mercedes; Andres, Raquel; Benitez, Javier; Hamann, Ute; Hogervorst, Frans B.; van Os, Theo A.; Verhoef, Senno; Meijers-Heijboer, Hanne E. J.; Wijnen, Juul; Garcia, Encarna B. Gomez; Ligtenberg, Marjolijn J.; Kriege, Mieke; Collee, Margriet; Ausems, Margreet G. E. M.; Oosterwijk, Jan C.; Peock, Susan; Frost, Debra; Ellis, Steve D.; Platte, Radka; Fineberg, Elena; Evans, D. Gareth; Lalloo, Fiona; Jacobs, Chris; Eeles, Ros; Adlard, Julian; Davidson, Rosemarie; Cole, Trevor; Cook, Jackie; Paterson, Joan; Douglas, Fiona; Brewer, Carole; Hodgson, Shirley; Morrison, Patrick J.; Walker, Lisa; Rogers, Mark T.; Donaldson, Alan; Dorkins, Huw; Godwin, Andrew K.; Bove, Betsy; Stoppa-Lyonnet, Dominique; Houdayer, Claude; Buecher, Bruno; de Pauw, Antoine; Mazoyer, Sylvie; Calender, Alain; Leone, Melanie; Bressac-de Paillerets, Brigitte; Caron, Olivier; Sobol, Hagay; Frenay, Marc; Prieur, Fabienne; Ferrer, Sandra Fert; Mortemousque, Isabelle; Buys, Saundra; Daly, Mary; Miron, Alexander; Terry, Mary Beth; Hopper, John L.; John, Esther M.; Southey, Melissa; Goldgar, David; Singer, Christian F.; Fink-Retter, Anneliese; Tea, Muy-Kheng; Kaulich, Daphne Geschwantler; Hansen, Thomas V. O.; Nielsen, Finn C.; Barkardottir, Rosa B.; Gaudet, Mia; Kirchhoff, Tomas; Joseph, Vijai; Dutra-Clarke, Ana; Offit, Kenneth; Piedmonte, Marion; Kirk, Judy; Cohn, David; Hurteau, Jean; Byron, John; Fiorica, James; Toland, Amanda E.; Montagna, Marco; Oliani, Cristina; Imyanitov, Evgeny; Isaacs, Claudine; Tihomirova, Laima; Blanco, Ignacio; Lazaro, Conxi; Teule, Alex; Del Valle, J.; Gayther, Simon A.; Odunsi, Kunle; Gross, Jenny; Karlan, Beth Y.; Olah, Edith; Teo, Soo-Hwang; Ganz, Patricia A.; Beattie, Mary S.; Dorfling, Cecelia M.; van Rensburg, Elizabeth Jansen; Diez, Orland; Kwong, Ava; Schmutzler, Rita K.; Wappenschmidt, Barbara; Engel, Christoph; Meindl, Alfons; Ditsch, Nina; Arnold, Norbert; Heidemann, Simone; Niederacher, Dieter; Preisler-Adams, Sabine; Gadzicki, Dorothea; Varon-Mateeva, Raymonda; Deissler, Helmut; Gehrig, Andrea; Sutter, Christian; Kast, Karin; Fiebig, Britta; Schaefer, Dieter; Caldes, Trinidad; de la Hoya, Miguel; Nevanlinna, Heli; Muranen, Taru A.; Lesperance, Bernard; Spurdle, Amanda B.; Neuhausen, Susan L.; Ding, Yuan C.; Wang, Xianshu; Fredericksen, Zachary; Pankratz, Vernon S.; Lindor, Noralane M.; Peterlongo, Paolo; Manoukian, Siranoush; Peissel, Bernard; Zaffaroni, Daniela; Bonanni, Bernardo; Bernard, Loris; Dolcetti, Riccardo; Papi, Laura; Ottini, Laura; Radice, Paolo; Greene, Mark H.; Loud, Jennifer T.; Andrulis, Irene L.; Ozcelik, Hilmi; Mulligan, Anna Marie; Glendon, Gord; Thomassen, Mads; Gerdes, Anne-Marie; Jensen, Uffe B.; Skytte, Anne-Bine; Kruse, Torben A.; Chenevix-Trench, Georgia; Couch, Fergus J.; Simard, Jacques; Easton, Douglas F.

    2012-01-01

    Introduction: Several common alleles have been shown to be associated with breast and/or ovarian cancer risk for BRCA1 and BRCA2 mutation carriers. Recent genome-wide association studies of breast cancer have identified eight additional breast cancer susceptibility loci: rs1011970 (9p21, CDKN2A/B),

  11. BRCA1 5272-1G>A and BRCA2 5374delTATG are founder mutations of high relevance for genetic counselling in breast/ovarian cancer families of Spanish origin.

    Science.gov (United States)

    Infante, M; Durán, M; Acedo, A; Pérez-Cabornero, L; Sanz, D J; García-González, M; Beristain, E; Esteban-Cardeñosa, E; de la Hoya, M; Teulé, A; Vega, A; Tejada, M-I; Lastra, E; Miner, C; Velasco, E A

    2010-01-01

    The distribution of BRCA1 and BRCA2 germ line mutations in breast/ovarian cancer families varies among different populations, which typically present a wide spectrum of unique mutations. Splicing mutation 5272-1G>A of BRCA1 and frameshift mutation 5374delTATG of BRCA2 are highly prevalent mutations in Castilla-León (Spain), accounting for 18.4% and 13.6% of BRCA1 and BRCA2 positive families, respectively. To test the presence of founder effects, 9 Spanish 5272-1G>A and 13 5374delTATG families were genotyped with polymorphic markers linked to BRCA1 or BRCA2. All the 5272-1G>A families shared a common haplotype in eight markers (1.1 Mb region) and the mutation age was estimated in 15 generations (approximately 380 years). A conserved haplotype associated to 5374delTATG was observed in four markers (0.82 Mb). The mutation occurred approximately 48 generations ago (approximately 1200 years). Each mutation likely arose from a common ancestor that could be traced to a small area of Castilla-León and expanded to other Spanish regions. They can have a significant impact on the clinical management of asymptomatic carriers as well as on the genetic screening strategy to be followed in populations with Spanish ancestries. PMID:19912264

  12. Common breast cancer susceptibility alleles are associated with tumor subtypes in BRCA1 and BRCA2 mutation carriers: results from the Consortium of Investigators of Modifiers of BRCA1/2

    DEFF Research Database (Denmark)

    Mulligan, Anna Marie; Couch, Fergus J; Barrowdale, Daniel;

    2011-01-01

    ABSTRACT: INTRODUCTION: Previous studies have demonstrated that common breast cancer susceptibility alleles are differentially associated with breast cancer risk for BRCA1 and/or BRCA2 mutation carriers. It is currently unknown how these alleles are associated with different breast cancer subtype...

  13. Common breast cancer susceptibility alleles are associated with tumour subtypes in BRCA1 and BRCA2 mutation carriers: results from the Consortium of Investigators of Modifiers of BRCA1/2

    NARCIS (Netherlands)

    Mulligan, A.M.; Couch, F.J.; Barrowdale, D.; Domchek, S.M.; Eccles, D.; Nevanlinna, H.; Ramus, S.J.; Robson, M.; Sherman, M.; Spurdle, A.B.; Wappenschmidt, B.; Lee, A.; McGuffog, L.; Healey, S.; Sinilnikova, O.M.; Janavicius, R.; Hansen, T.V.; Nielsen, F.C.; Ejlertsen, B.; Osorio, A.; Munoz-Repeto, I.; Duran, M.; Godino, J.; Pertesi, M.; Benitez, J.; Peterlongo, P.; Manoukian, S.; Peissel, B.; Zaffaroni, D.; Cattaneo, E.; Bonanni, B.; Viel, A.; Pasini, B.; Papi, L.; Ottini, L.; Savarese, A.; Bernard, L.; Radice, P.; Hamann, U.; Verheus, M.; Meijers-Heijboer, H.E.; Wijnen, J.; Gomez Garcia, E.B.; Nelen, M.R.; Kets, C.M.; Seynaeve, C.; Tilanus-Linthorst, M.M.; Luijt, R.B. van der; Os, T.V.; Rookus, M.; Frost, D.; Jones, J.L.; Evans, D.G.; Lalloo, F.; Eeles, R.; Izatt, L.; Adlard, J.; Davidson, R.; Cook, J.; Donaldson, A.; Dorkins, H.; Gregory, H.; Eason, J.; Houghton, C.; Barwell, J.; Side, L.E.; McCann, E.; Murray, A.; Peock, S.; Godwin, A.K.; Schmutzler, R.K.; Rhiem, K.; Engel, C.; Meindl, A.; Ruehl, I.; Arnold, N.; Niederacher, D.; Sutter, C.; Deissler, H.; Gadzicki, D.; Kast, K.; Preisler-Adams, S.; Varon-Mateeva, R.; Schoenbuchner, I.; Fiebig, B.; Heinritz, W.; Schafer, D.; Gevensleben, H.; Caux-Moncoutier, V.; Fassy-Colcombet, M.; Cornelis, F.; Mazoyer, S.; Leone, M.; Boutry-Kryza, N.; Hardouin, A.; Berthet, P.; Muller, D.; Fricker, J.P.; Mortemousque, I.; Pujol, P.

    2011-01-01

    ABSTRACT: INTRODUCTION: Previous studies have demonstrated that common breast cancer susceptibility alleles are differentially associated with breast cancer risk for BRCA1 and/or BRCA2 mutation carriers. It is currently unknown how these alleles are associated with different breast cancer subtypes i

  14. Common breast cancer susceptibility alleles are associated with tumour subtypes in BRCA1 and BRCA2 mutation carriers : results from the Consortium of Investigators of Modifiers of BRCA1/2

    NARCIS (Netherlands)

    Mulligan, Anna Marie; Couch, Fergus J.; Barrowdale, Daniel; Domchek, Susan M.; Eccles, Diana; Nevanlinna, Heli; Ramus, Susan J.; Robson, Mark; Sherman, Mark; Spurdle, Amanda B.; Wappenschmidt, Barbara; Lee, Andrew; McGuffog, Lesley; Healey, Sue; Sinilnikova, Olga M.; Janavicius, Ramunas; Hansen, Thomas V. O.; Nielsen, Finn C.; Ejlertsen, Bent; Osorio, Ana; Munoz-Repeto, Ivan; Duran, Mercedes; Godino, Javier; Pertesi, Maroulio; Benitez, Javier; Peterlongo, Paolo; Manoukian, Siranoush; Peissel, Bernard; Zaffaroni, Daniela; Cattaneo, Elisa; Bonanni, Bernardo; Viel, Alessandra; Pasini, Barbara; Papi, Laura; Ottini, Laura; Savarese, Antonella; Bernard, Loris; Radice, Paolo; Hamann, Ute; Verheus, Martijn; Meijers-Heijboer, Hanne E. J.; Wijnen, Juul; Garcia, Encarna B. Gomez; Nelen, Marcel R.; Kets, C. Marleen; Seynaeve, Caroline; Tilanus-Linthorst, Madeleine M. A.; van der Luijt, Rob B.; van Os, Theo; Rookus, Matti; Frost, Debra; Jones, J. Louise; Evans, D. Gareth; Lalloo, Fiona; Eeles, Ros; Izatt, Louise; Adlard, Julian; Davidson, Rosemarie; Cook, Jackie; Donaldson, Alan; Dorkins, Huw; Gregory, Helen; Eason, Jacqueline; Houghton, Catherine; Barwell, Julian; Side, Lucy E.; McCann, Emma; Murray, Alex; Peock, Susan; Godwin, Andrew K.; Schmutzler, Rita K.; Rhiem, Kerstin; Engel, Christoph; Meindl, Alfons; Ruehl, Ina; Arnold, Norbert; Niederacher, Dieter; Sutter, Christian; Deissler, Helmut; Gadzicki, Dorothea; Kast, Karin; Preisler-Adams, Sabine; Varon-Mateeva, Raymonda; Schoenbuchner, Ines; Fiebig, Britta; Heinritz, Wolfram; Schaefer, Dieter; Gevensleben, Heidrun; Caux-Moncoutier, Virginie; Fassy-Colcombet, Marion; Cornelis, Francois; Mazoyer, Sylvie; Leone, Melanie; Boutry-Kryza, Nadia; Hardouin, Agnes; Berthet, Pascaline; Muller, Daniele; Fricker, Jean-Pierre; Mortemousque, Isabelle; Pujol, Pascal; Coupier, Isabelle; Lebrun, Marine; Kientz, Caroline; Longy, Michel; Sevenet, Nicolas; Stoppa-Lyonnet, Dominique; Isaacs, Claudine; Caldes, Trinidad; de la Hoya, Miguel; Heikkinen, Tuomas; Aittomaki, Kristiina; Blanco, Ignacio; Lazaro, Conxi; Barkardottir, Rosa B.; Soucy, Penny; Dumont, Martine; Simard, Jacques; Montagna, Marco; Tognazzo, Silvia; D'Andrea, Emma; Fox, Stephen; Yan, Max; Rebbeck, Tim; Olopade, Olufunmilayo I.; Weitzel, Jeffrey N.; Lynch, Henry T.; Ganz, Patricia A.; Tomlinson, Gail E.; Wang, Xianshu; Fredericksen, Zachary; Pankratz, Vernon S.; Lindor, Noralane M.; Szabo, Csilla; Offit, Kenneth; Sakr, Rita; Gaudet, Mia; Bhatia, Jasmine; Kauff, Noah; Singer, Christian F.; Tea, Muy-Kheng; Gschwantler-Kaulich, Daphne; Fink-Retter, Anneliese; Mai, Phuong L.; Greene, Mark H.; Imyanitov, Evgeny; O'Malley, Frances P.; Ozcelik, Hilmi; Glendon, Gordon; Toland, Amanda E.; Gerdes, Anne-Marie; Thomassen, Mads; Kruse, Torben A.; Jensen, Uffe Birk; Skytte, Anne-Bine; Caligo, Maria A.; Soller, Maria; Henriksson, Karin; Wachenfeldt, von Anna; Arver, Brita; Stenmark-Askmalm, Marie; Karlsson, Per; Ding, Yuan Chun; Neuhausen, Susan L.; Beattie, Mary; Pharoah, Paul D. P.; Moysich, Kirsten B.; Nathanson, Katherine L.; Karlan, Beth Y.; Gross, Jenny; John, Esther M.; Daly, Mary B.; Buys, Saundra M.; Southey, Melissa C.; Hopper, John L.; Terry, Mary Beth; Chung, Wendy; Miron, Alexander F.; Goldgar, David; Chenevix-Trench, Georgia; Easton, Douglas F.; Andrulis, Irene L.; Antoniou, Antonis C.

    2011-01-01

    Introduction: Previous studies have demonstrated that common breast cancer susceptibility alleles are differentially associated with breast cancer risk for BRCA1 and/or BRCA2 mutation carriers. It is currently unknown how these alleles are associated with different breast cancer subtypes in BRCA1 an

  15. Evaluation of an amplicon-based next-generation sequencing panel for detection of BRCA1 and BRCA2 genetic variants.

    Science.gov (United States)

    Shin, Saeam; Hwang, In Sik; Lee, Seung-Tae; Choi, Jong Rak

    2016-08-01

    The recent advances in the next-generation sequencing (NGS) technology have enabled fast, accurate, and cost-effective genetic testing. Here, we evaluated the performance of a targeted NGS panel for BRCA1/2 sequencing and confirmed its applicability in routine clinical diagnostics. We tested samples from 88 patients using the TruSeq custom panel (Illumina Inc, USA) and a MiSeq sequencer (Illumina) and compared the results to the outcomes of conventional Sanger sequencing. All 1015 sequence variations identified by Sanger sequencing were detected by NGS, except for one missense variant that might have been missed due to a rare mutation on a primer-binding site. One deletion variation, c.1909 + 12delT of BRCA2, was falsely called in all samples due to a homopolymer error. In addition, seven different single-nucleotide substitutions with low variant frequencies (range: 16.2-33.3 %) were falsely called by NGS. In a separate batch, 10 different false-positive variations were found in five samples. The overall sensitivity and positive predictive value of NGS were estimated to be 99.9 and 87.5 %, respectively. The false-positive results could be excluded by setting quality and alternative allele ratio filters and/or by visual inspection using the IGV software. Targeted NGS panel for BRCA1 and BRCA2 showed an excellent agreement with Sanger sequencing results. We therefore conclude that this NGS panel can be used for routine diagnostic method in a clinical genetic laboratory. PMID:27383479

  16. No germline mutations in the histone acetyltransferase gene EP300 in BRCA1 and BRCA2 negative families with breast cancer and gastric, pancreatic, or colorectal cancer

    International Nuclear Information System (INIS)

    Mutations in BRCA1, BRCA2, ATM, TP53, CHK2 and PTEN account for many, but not all, multiple-case breast and ovarian cancer families. The histone acetyltransferase gene EP300 may function as a tumour suppressor gene because it is sometimes somatically mutated in breast, colorectal, gastric and pancreatic cancers, and is located on a region of chromosome 22 that frequently undergoes loss of heterozygosity in many cancer types. We hypothesized that germline mutations in EP300 may account for some breast cancer families that include cases of gastric, pancreatic and/or colorectal cancer. We screened the entire coding region of EP300 for mutations in the youngest affected members of 23 non-BRCA1/BRCA2 breast cancer families with at least one confirmed case of gastric, pancreatic and/or colorectal cancer. These families were ascertained in Australia through the Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer. Denaturing HPLC analysis identified a heterozygous alteration at codon 211, specifically a GGC to AGC (glycine to serine) alteration, in two individuals. This conservative amino acid change was not within any known functional domains of EP300. The frequency of the Ser211 variant did not differ significanlty between a series of 352 breast cancer patients (4.0%) and 254 control individuals (2.8%; P = 0.5). The present study does not support a major role for EP300 mutations in breast and ovarian cancer families with a history of gastric, pancreatic and/or colorectal cancer

  17. Mediating Structures in Sámi Language Revitalisation

    Directory of Open Access Journals (Sweden)

    Erika Sarivaara

    2016-02-01

    Full Text Available The revitalisation of the Sámi languages and support for language domains are central educational measures in the post-assimilation situation in Northern Europe. Taking critical indigenous education as the starting point, this meta-theoretical article discusses language revitalisation through mediating structures. Mediating structures provide the tools necessary to use language revitalisation as a means to counter the legacy of assimilation that has seriously affected the Sámi languages and caused language change. The article brings together recent research on the revitalisation of the Sámi languages. These studies are oriented towards the present situation of the Sámi languages and efforts to revive the languages. Relying on previous studies as well as new research, the article presents a communal model of language recovery, which facilitates an increase in the number of language speakers and also supports language domains. Such a mediating language revitalisation model builds social harmony in a postcolonial situation. The article emphasises the key tasks involved in the recovery of endangered languages.

  18. BRCA1 and BRCA2 gene mutations in familial breast cancer%家族性乳腺癌家系成员乳腺癌易感基因突变的研究

    Institute of Scientific and Technical Information of China (English)

    李军改; 回天立; 李峥; 白杨; 马国明; 孙玉巧; 李春晓; 耿翠芝

    2012-01-01

    目的 研究河北省地区家族性乳腺癌家系中的患者及健康一级亲属乳腺癌易感基因1(BRCA1)和乳腺癌易感基因2(BRCA2)突变位点及携带情况.方法 研究对象为2002年6月至2008年5月河北医科大学第四医院接诊的乳腺癌患者及其亲属,分别来自12个独立的汉族家族性乳腺癌家系,该家系中有2个及2个以上一级或二级亲属乳腺癌患病史,研究病例包括13例患者及46例健康一级亲属,共59例样本.由外周血提取基因组DNA,采用聚合酶链反应-单链构象多态性分析(PCR-SSCP)和基因测序技术对国内外报告中常见的4个BRCA1/BRCA2突变热点区域(BRCA1:外显子2、11、20;BRCA2外显子11)进行检测.结果 发现1个BRCA1突变位点(4193insA)和1个BRCA2突变位点(5329insT),全部为移码突变;发现4个变异位点(BRCA1:4165T>A 、287G>C,BRCA2:6251G>T、5416C>A),4193insA、5329insT、287G>C携带者的家系中均有3例乳腺癌患者.结论 BRCA1(4193insA)、BRCA2(5329insT)以及BRCA1:4165T>A 、287G>C和BRCA2:6251G>T、5416C>A可能是河北省家族性乳腺癌相关性突变位点,其携带者家系中乳腺癌发病率明显升高,建议对其一级亲属密切随访或尽早进行手术或药物干预.%Objectiff To investigate mutations and the carrying of breast cancer susceptibility gene ( BRCA) 1 and BRCA2 among patients and their healthy first degree relatives in family constellation of breast cancer in Hebei province . Mtehods This study involved breast cancer patients treated in the Fourth Affiliated Hospital of Hebei Medical University from June, 2002to May, 2008 and their relative, including 59 samples (13 patients and 46 healthy first degree relatives from 12 independent families of Han Nationality in which 2 or more first or second degree relatives had breast cancer history . Four BRCA1/ BRCA2 mutation hot spots ( BRCA1; Exon2,11,20 ; BRCA2; Exonl 1) commonly reported in literature were detected by extracting DNA from

  19. Development and Validation of a Next-Generation Sequencing Assay for BRCA1 and BRCA2 Variants for the Clinical Laboratory.

    Science.gov (United States)

    Strom, Charles M; Rivera, Steven; Elzinga, Christopher; Angeloni, Taraneh; Rosenthal, Sun Hee; Goos-Root, Dana; Siaw, Martin; Platt, Jamie; Braastadt, Cory; Cheng, Linda; Ross, David; Sun, Weimin

    2015-01-01

    The objective of this study was to design and validate a next-generation sequencing assay (NGS) to detect BRCA1 and BRCA2 mutations. We developed an assay using random shearing of genomic DNA followed by RNA bait tile hybridization and NGS sequencing on both the Illumina MiSeq and Ion Personal Gene Machine (PGM). We determined that the MiSeq Reporter software supplied with the instrument could not detect deletions greater than 9 base pairs. Therefore, we developed an alternative alignment and variant calling software, Quest Sequencing Analysis Pipeline (QSAP), that was capable of detecting large deletions and insertions. In validation studies, we used DNA from 27 stem cell lines, all with known deleterious BRCA1 or BRCA2 mutations, and DNA from 67 consented control individuals who had a total of 352 benign variants. Both the MiSeq/QSAP combination and PGM/Torrent Suite combination had 100% sensitivity for the 379 known variants in the validation series. However, the PGM/Torrent Suite combination had a lower intra- and inter-assay precision of 96.2% and 96.7%, respectively when compared to the MiSeq/QSAP combination of 100% and 99.4%, respectively. All PGM/Torrent Suite inconsistencies were false-positive variant assignments. We began commercial testing using both platforms and in the first 521 clinical samples MiSeq/QSAP had 100% sensitivity for BRCA1/2 variants, including a 64-bp deletion and a 10-bp insertion not identified by PGM/Torrent Suite, which also suffered from a high false-positive rate. Neither the MiSeq nor PGM platform with their supplied alignment and variant calling software are appropriate for a clinical laboratory BRCA sequencing test. We have developed an NGS BRCA1/2 sequencing assay, MiSeq/QSAP, with 100% analytic sensitivity and specificity in the validation set consisting of 379 variants. The MiSeq/QSAP combination has sufficient performance for use in a clinical laboratory. PMID:26295337

  20. Structural equation modeling versus marginal structural modeling for assessing mediation in the presence of posttreatment confounding.

    Science.gov (United States)

    Moerkerke, Beatrijs; Loeys, Tom; Vansteelandt, Stijn

    2015-06-01

    Inverse probability weighting for marginal structural models has been suggested as a strategy to estimate the direct effect of a treatment or exposure on an outcome in studies where the effect of mediator on outcome is subject to posttreatment confounding. This type of confounding, whereby confounders of the effect of mediator on outcome are themselves affected by the exposure, complicates mediation analyses and necessitates apt analysis strategies. In this article, we contrast the inverse probability weighting approach with the traditional path analysis approach to mediation analysis. We show that in a particular class of linear models, adjustment for posttreatment confounding can be realized via a fairly standard modification of the traditional path analysis approach. The resulting approach is simpler; by avoiding inverse probability weighting, it moreover results in direct effect estimators with smaller finite sample bias and greater precision. We further show that a particular variant of the G-estimation approach from the causal inference literature is equivalent with the path analysis approach in simple linear settings but is more generally applicable in settings with interactions and/or noncontinuous mediators and confounders. We conclude that the use of inverse probability weighting for marginal structural models to adjust for posttreatment confounding in mediation analysis is primarily indicated in nonlinear models for the outcome. PMID:25751514

  1. High rate of mutations in the BRCA1, BRCA2, CHEK2, NBN, and BLM genes in Russian ovarian cancer patients

    Directory of Open Access Journals (Sweden)

    Ye. I. Bateneva

    2015-01-01

    Full Text Available Background. The early diagnosis of ovarian cancer (OC is an important problem in modern gynecological oncology due to significant detection rates for late-stage tumors. Intensive screening of patients from high-risk groups that include OC predisposition gene mutation carriers is indicated.Subjects and methods. An unselected group of 202 patients with OC and two control groups of blood donors: 591 healthy females; 1197 persons (including 591 females, 606 males were examined. Patients and healthy individuals who identified themselves as ethnic Russians and residents of the Russian Federation participated in the study. Whole peripheral blood samples were collected at the Clinical Subdivisions of the N.N. Blokhin Russian Cancer Research Center and at the Department of Transfusiology of the Acad. B.V. Petrovsky Russian Research Center of Surgery in 2012–2013. Informed consent was obtained from all the participants. DNA was extracted using a Prep-GS-Genetics reagent kit. Real-time polymerase chain reaction genotyping assay was carried out by melting-curve analysis employing an BRCA SNP genotyping kit(BRCA1 and BRCA2 gene mutations and original oligonucleotides (CHEK2, NBN, and BLM gene mutations. Thirteen population-specific mutations, including 7 (185delAG, 4153delA, 5382insC, 3819delGTAAA, 3875delGTCT, 300T>G, and 2080delA in the BRCA1 gene, 1 (6174delT in the BRCA2 gene, 3 (1100delC, IVS2+1G>A, and 470T>C in the CHEK2 gene, 1 (657delACAAA in the NBN gene, and 1 (1642C>T in the BLM gene, were genotyped. Polymerase chain reaction was performed using a DTprime real-time detection thermal cycler.Results and discussion. BRCA1 and BRCA2 gene mutations were detected in 46 (22.8 % patients with OC; the prevailing mutation in the BRCA1 gene was 5382insC (58.7 %. OC was diagnosed in 32.6 % of the patients aged 51 years or older. The rate of moderate-penetrance mutations (1100delC and IVS2+1G>A in the CHEK2 gene, 657del5 in the NBN gene, and 1642

  2. Common breast cancer susceptibility alleles are associated with tumor subtypes in BRCA1 and BRCA2 mutation carriers: results from the Consortium of Investigators of Modifiers of BRCA1/2

    DEFF Research Database (Denmark)

    Mulligan, Anna Marie; Couch, Fergus J; Barrowdale, Daniel;

    2011-01-01

    ABSTRACT: INTRODUCTION: Previous studies have demonstrated that common breast cancer susceptibility alleles are differentially associated with breast cancer risk for BRCA1 and/or BRCA2 mutation carriers. It is currently unknown how these alleles are associated with different breast cancer subtype...... subtypes. As more risk modifying variants are identified, incorporating these associations into breast cancer subtype-specific risk models may improve clinical management for mutation carriers....

  3. Non-catalytic Roles for XPG with BRCA1 and BRCA2 in Homologous Recombination and Genome Stability

    DEFF Research Database (Denmark)

    Trego, Kelly S.; Groesser, Torsten; Davalos, Albert R.;

    2016-01-01

    XPG is a structure-specific endonuclease required for nucleotide excision repair, and incision-defective XPG mutations cause the skin cancer-prone syndrome xeroderma pigmentosum. Truncating mutations instead cause the neurodevelopmental progeroid disorder Cockayne syndrome, but little is known...

  4. Climate mediates the effects of disturbance on ant assemblage structure

    Science.gov (United States)

    Gibb, Heloise; Sanders, Nathan J.; Dunn, Robert R.; Watson, Simon; Photakis, Manoli; Abril, Silvia; Andersen, Alan N.; Angulo, Elena; Armbrecht, Inge; Arnan, Xavier; Baccaro, Fabricio B.; Bishop, Tom R.; Boulay, Raphael; Castracani, Cristina; Del Toro, Israel; Delsinne, Thibaut; Diaz, Mireia; Donoso, David A.; Enríquez, Martha L.; Fayle, Tom M.; Feener, Donald H.; Fitzpatrick, Matthew C.; Gómez, Crisanto; Grasso, Donato A.; Groc, Sarah; Heterick, Brian; Hoffmann, Benjamin D.; Lach, Lori; Lattke, John; Leponce, Maurice; Lessard, Jean-Philippe; Longino, John; Lucky, Andrea; Majer, Jonathan; Menke, Sean B.; Mezger, Dirk; Mori, Alessandra; Munyai, Thinandavha C.; Paknia, Omid; Pearce-Duvet, Jessica; Pfeiffer, Martin; Philpott, Stacy M.; de Souza, Jorge L. P.; Tista, Melanie; Vasconcelos, Heraldo L.; Vonshak, Merav; Parr, Catherine L.

    2015-01-01

    Many studies have focused on the impacts of climate change on biological assemblages, yet little is known about how climate interacts with other major anthropogenic influences on biodiversity, such as habitat disturbance. Using a unique global database of 1128 local ant assemblages, we examined whether climate mediates the effects of habitat disturbance on assemblage structure at a global scale. Species richness and evenness were associated positively with temperature, and negatively with disturbance. However, the interaction among temperature, precipitation and disturbance shaped species richness and evenness. The effect was manifested through a failure of species richness to increase substantially with temperature in transformed habitats at low precipitation. At low precipitation levels, evenness increased with temperature in undisturbed sites, peaked at medium temperatures in disturbed sites and remained low in transformed sites. In warmer climates with lower rainfall, the effects of increasing disturbance on species richness and evenness were akin to decreases in temperature of up to 9°C. Anthropogenic disturbance and ongoing climate change may interact in complicated ways to shape the structure of assemblages, with hot, arid environments likely to be at greatest risk. PMID:25994675

  5. "Social separation" among women under 40 years of age diagnosed with breast cancer and carrying a BRCA1 or BRCA2 mutation.

    Science.gov (United States)

    Kenen, Regina; Ardern-Jones, Audrey; Eeles, Rosalind

    2006-06-01

    We conducted an exploratory, qualitative study investigating experiences of women who had developed breast cancer under the age of 40 and who were identified as BRCA1 or BRCA2 mutation carriers. These germline mutation carriers face an increased lifetime risk of a second primary breast cancer and an increased risk for a primary ovarian cancer. Thirteen women who fit this criteria participated in three focus groups conducted at a major cancer center in the UK during Spring 2003. We asked broad, open-ended questions that allowed for a wide range of responses about their cancer and genetic testing experiences, physical and psycho-social concerns, family and partner reactions and their need for social support. The women expressed feelings of devastation, loneliness, feeling different and isolation, ambivalence about having to support family members, worries about partner's anxiety and depression, and anxiety about talking to family members, especially children. These feelings were stronger after the cancer diagnosis and compounded by the genetic test results that occurred at a later time. We also found that, at least temporarily, the women experienced what we call "social separation"--emotional distance from, or dissonance with groups they interact with or are part of, e.g., family and friends, frequently leading to a reduction in communication or a change in previously unstated, but accepted normal interaction. We concentrate on a few characteristics of social separation-feelings of aloneness, isolation and separation, use of silence and verbal discretion, the relationship between estrangement and kinship interaction and norm disruption, and are looking at social patterns of interpersonal relationships that may occur when risk and illness statuses are new and framing and feeling rules have not as yet been clearly developed due to a cultural lag. PMID:16724273

  6. The Micropillar Structure on Silk Fibroin Film Influence Intercellular Connection Mediated by Nanotubular Structures

    Directory of Open Access Journals (Sweden)

    Renchuan You

    2014-06-01

    Full Text Available Tunneling nanotubes are important membrane channels for cell-to-cell communication. In this study, we investigated the effect of the microenvironment on nanotubular structures by preparing a three-dimensional silk fibroin micropillar structure. In previous reports, tunneling nanotubes were described as stretched membrane channels between interconnected cells at their nearest distance. They hover freely in the cell culture medium and do not contact with the substratum. Interestingly, the micropillars could provide supporting points for nanotubular connection on silk fibroin films, where nanotubular structure formed a stable anchor at contact points. Consequently, the extension direction of nanotubular structure was affected by the micropillar topography. This result suggests that the hovering tunneling nanotubes in the culture medium will come into contact with the raised roadblock on the substrates during long-distance extension. These findings imply that the surface microtopography of biomaterials have an important influence on cell communication mediated by tunneling nanotubes.

  7. Differences in the frequency and distribution of BRCA1 and BRCA2 mutations in breast/ovarian cancer cases from the Basque country with respect to the Spanish population: implications for genetic counselling.

    Science.gov (United States)

    Beristain, E; Martínez-Bouzas, C; Guerra, I; Viguera, N; Moreno, J; Ibañez, E; Díez, J; Rodríguez, F; Mallabiabarrena, G; Luján, S; Gorostiaga, J; De Pablo, J L; Mendizabal, J L; Tejada, M I

    2007-12-01

    The prevalence of unique and recurrent BRCA1 and BRCA2 pathogenic mutations and unclassified variants varies among different populations. Two hundred and thirty-six breast and/or ovarian cancer patients were analysed to clarify the role of these genes in the Basque Country. We also studied 130 healthy women from the general population from the same region. Fifteen different pathological mutations were found in 16 index cases: 10 truncating mutations, 4 missense mutations and 1 splicing mutation. c.3002_3003insT and c.5788_5789delGT, both in exon 11 of BRCA2 have not previously been described. No pathological mutations were found in cases of sporadic juvenile breast cancer. There are no recurrent mutations in our population; apart from the mutation c.9254_9258del5, which appears in only two index cases. We have also found a lot of variants whose effect is unknown. From these variants, 17 have not previously been described: 6 missenses, 6 synonymous and 5 alterations in intronic regions. We would like to highlight the fact that 14.3% of patients with 3 or more cases of breast cancer in the family, and 16.7% of patients with family history of breast and ovarian cancer, present a pathological mutation in BRCA1 or BRCA2. This manuscript demonstrates that each population can have different mutations and due to this, Genetic Counselling and selection criteria must be different for each population. Furthermore, this article describes for the first time some new mutations and unclassified variants found in our population. PMID:17262179

  8. ENIGMA-Evidence-based network for the interpretation of germline mutant alleles: An international initiative to evaluate risk and clinical significance associated with sequence variation in BRCA1 and BRCA2 genes

    DEFF Research Database (Denmark)

    Spurdle, Amanda B; Healey, Sue; Devereau, Andrew;

    2012-01-01

    As genetic testing for predisposition to human diseases has become an increasingly common practice in medicine, the need for clear interpretation of the test results is apparent. However, for many disease genes, including the breast cancer susceptibility genes BRCA1 and BRCA2, a significant...... than 100 research scientists and clinicians from 19 countries. Within ENIGMA, there are presently six working groups focused on the following topics: analysis, clinical, database, functional, tumor histopathology, and mRNA splicing. ENIGMA provides a mechanism to pool resources, exchange methods and...

  9. Average Risks of Breast and Ovarian Cancer Associated with BRCA1 or BRCA2 Mutations Detected in Case Series Unselected for Family History: A Combined Analysis of 22 Studies

    OpenAIRE

    Antoniou, A; Pharoah, P. D. P.; Narod, S.; Risch, H A; Eyfjord, J. E.; Hopper, J L; Loman, N.; Olsson, H; Johannsson, O.; Borg, Å.; Pasini, B; Radice, P.; Manoukian, S; Eccles, D M; N. Tang

    2003-01-01

    Germline mutations in BRCA1 and BRCA2 confer high risks of breast and ovarian cancer, but the average magnitude of these risks is uncertain and may depend on the context. Estimates based on multiple-case families may be enriched for mutations of higher risk and/or other familial risk factors, whereas risk estimates from studies based on cases unselected for family history have been imprecise. We pooled pedigree data from 22 studies involving 8,139 index case patients unselected for family his...

  10. CBR with Commonsense Reasoning and Structure Mapping: An Application to Mediation

    CERN Document Server

    Baydin, Atilim Gunes; Simoff, Simeon; Sierra, Carles

    2011-01-01

    Mediation is an important method in dispute resolution. We implement a case based reasoning approach to mediation integrating analogical and commonsense reasoning components that allow an artificial mediation agent to satisfy requirements expected from a human mediator, in particular: utilizing experience with cases in different domains; and structurally transforming the set of issues for a better solution. We utilize a case structure based on ontologies reflecting the perceptions of the parties in dispute. The analogical reasoning component, employing the Structure Mapping Theory from psychology, provides a flexibility to respond innovatively in unusual circumstances, in contrast with conventional approaches confined into specialized problem domains. We aim to build a mediation case base incorporating real world instances ranging from interpersonal or intergroup disputes to international conflicts.

  11. Causal Models for Mediation Analysis: An Introduction to Structural Mean Models.

    Science.gov (United States)

    Zheng, Cheng; Atkins, David C; Zhou, Xiao-Hua; Rhew, Isaac C

    2015-01-01

    Mediation analyses are critical to understanding why behavioral interventions work. To yield a causal interpretation, common mediation approaches must make an assumption of "sequential ignorability." The current article describes an alternative approach to causal mediation called structural mean models (SMMs). A specific SMM called a rank-preserving model (RPM) is introduced in the context of an applied example. Particular attention is given to the assumptions of both approaches to mediation. Applying both mediation approaches to the college student drinking data yield notable differences in the magnitude of effects. Simulated examples reveal instances in which the traditional approach can yield strongly biased results, whereas the RPM approach remains unbiased in these cases. At the same time, the RPM approach has its own assumptions that must be met for correct inference, such as the existence of a covariate that strongly moderates the effect of the intervention on the mediator and no unmeasured confounders that also serve as a moderator of the effect of the intervention or the mediator on the outcome. The RPM approach to mediation offers an alternative way to perform mediation analysis when there may be unmeasured confounders. PMID:26717122

  12. Structural Differentiation and Ambidexterity: The Mediating Role of Integration Mechanisms

    OpenAIRE

    Jansen, Justin; Tempelaar, Michiel; Bosch, Frans; Volberda, Henk

    2008-01-01

    textabstractPrior studies have emphasized that structural attributes are crucial to simultaneously pursuing exploration and exploitation, yet our understanding of antecedents of ambidexterity is still limited. Structural differentiation can help ambidextrous organizations to maintain multiple inconsistent and conflicting demands; however, differentiated exploratory and exploitative activities need to be mobilized, coordinated, integrated, and applied. Based on this idea, we delineate formal a...

  13. Membrane-mediated changes in the structure of chromosomes.

    Science.gov (United States)

    Belyaev, N D; Budker, V G; Dubrovskaya, V A; Khristoljubova, N B; Kiseleva, E V; Matveeva, N M; Sukojan, M A

    1985-01-01

    In the present paper the interaction of metaphase chromosomes and chromatin with model and natural lipid membranes was studied. It was shown that chromatin and chromosomes are able to form complexes with membranes in the presence of divalent cations. In such complexes, the typical structure of chromosomes is altered. The character of this alteration in chromosomal structure was investigated with the use of electron microscopy and chemical modification with dimethylsulphate (DMS). The latter is possible because, according to the presented data, the condensation of chromatin into chromosomes is associated with a decrease in accessibility of N-3 in adenine (the protection of the minor groove of DNA) to modifications, and with an increased methylation of N-1 in adenine (the disarrangement of the secondary structure of DNA). It was shown that the interaction of chromosomes with liposomes provides various levels of unfolding up to the appearance of chromatin-like structures. The secondary DNA structure of decondensed chromosomes coincides with the secondary structure of chromosomal but not chromatin DNA, whereas the extent of shielding of the minor groove of DNA in such decondensed structures typical for chromatin DNA. It is possible to suggest that the chromosomal decondensation in telophase of mitosis is initiated by the action of a membrane component of the developing nuclear envelope. PMID:3926416

  14. Climate mediates the effects of disturbance on ant assemblage structure

    Czech Academy of Sciences Publication Activity Database

    Gibb, H.; Sanders, N. J.; Dunn, R. R.; Watson, S.; Photakis, M.; Abril, S.; Andersen, A. N.; Angulo, E.; Armbrecht, I.; Arnan, X.; Baccaro, F. B.; Bishop, T. R.; Boulay, R.; Castracani, C.; Del Toro, I.; Delsinne, T.; Diaz, M.; Donoso, D. A.; Enríquez, M. L.; Fayle, Tom; Feener Jr., D. H.; Fitzpatrik, M. C.; Gómez, C.; Grasso, D. A.; Groc, S.; Heterick, B.; Hoffmann, B. D.; Lach, L.; Lattke, J.; Leponce, M.; Lessard, J.-P.; Longino, J.; Lucky, A.; Majer, J.; Menke, S. B.; Mezger, D.; Mori, A.; Munyai, T. C.; Paknia, O.; Pearce-Duvet, J.; Pfeiffer, M.; Philpott, S. M.; de Souza, J. L. P.; Tista, M.; Vasconcelos, H. L.; Vonshak, M.; Parr, C. L.

    2015-01-01

    Roč. 282, č. 1808 (2015), article number 20150418. ISSN 0962-8452 Institutional support: RVO:60077344 Keywords : assemblage structure * dominance * global warming Subject RIV: EH - Ecology, Behaviour Impact factor: 5.051, year: 2014

  15. Factors mediating the restoration of structurally degraded soils

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Moldrup, Per; Schjønning, Per;

    the incubation period, structural stability estimated as the amount of water-dispersible clay decreased with prevailing moisture content, and native organic matter. Also, microbial activity significantly increased with addition of exogenous organic matter. At the end of incubation, there was...... kaolinitic soil and lowest for the smectitic soil. Among the illitic soils, aggregate workability increased with native organic matter content. Addition of exogenous organic material showed little effect on soil physical properties. Results points to the possibility of regenerating the structure of......Soil structure is essential for sustained provision of ecosystem services such as water filtering and storage, waste disposal, carbon sequestration and many more. Structural degradation/disaggregation of soils emanating from human activities such as mining, grading and filling interferes with the...

  16. Chirality-Mediated Mechanical and Structural Properties of Oligopeptide Hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Taraban, Marc B.; Feng, Yue; Hammouda, Boualem; Hyland, Laura L.; Yu, Y. Bruce (NIST); (Maryland)

    2012-10-29

    The origin and the effects of homochirality in the biological world continuously stimulate numerous hypotheses and much debate. This work attempts to look at the biohomochirality issue from a different angle - the mechanical properties of the bulk biomaterial and their relation to nanoscale structures. Using a pair of oppositely charged peptides that co-assemble into hydrogels, we systematically investigated the effect of chirality on the mechanical properties of these hydrogels through different combinations of syndiotactic and isotactic peptides. It was found that homochirality confers mechanical advantage, resulting in a higher elastic modulus and strain yield value. Yet, heterochirality confers kinetic advantage, resulting in faster gelation. Structurally, both homochiral and heterochiral hydrogels are made of fibers interconnected by lappet-like webs, but the homochiral peptide fibers are thicker and denser. These results highlight the possible role of biohomochirality in the evolution and/or natural selection of biomaterials.

  17. Structural basis for angiopoietin-1–mediated signaling initiation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xuehong [Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Seegar, Tom C. M. [Virginia Commonwealth Univ., Richmond, VA (United States); Dalton, Annamarie C. [Virginia Commonwealth Univ., Richmond, VA (United States); Tzvetkova-Robev, Dorothea [Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Goldgur, Yehuda [Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Rajashankar, Kanagalaghatta R. [Argonne National Lab. (ANL), Argonne, IL (United States); Nikolov, Dimitar B. [Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Barton, William A. [Virginia Commonwealth Univ., Richmond, VA (United States)

    2013-04-30

    Angiogenesis is a complex cellular process involving multiple regulatory growth factors and growth factor receptors. Among them, the ligands for the endothelial-specific tunica intima endothelial receptor tyrosine kinase 2 (Tie2) receptor kinase, angiopoietin-1 (Ang1) and Ang2, play essential roles in balancing vessel stability and regression during both developmental and tumor-induced angiogenesis. Despite possessing a high degree of sequence identity, Ang1 and Ang2 have distinct functional roles and cell-signaling characteristics. Here, we present the crystal structures of Ang1 both unbound and in complex with the Tie2 ectodomain. Comparison of the Ang1-containing structures with their Ang2-containing counterparts provide insight into the mechanism of receptor activation and reveal molecular surfaces important for interactions with Tie2 coreceptors and associated signaling proteins. Using structure-based mutagenesis, we identify a loop within the angiopoietin P domain, adjacent to the receptor-binding interface, which confers the specific agonist/antagonist properties of the molecule. We demonstrate using cell-based assays that an Ang2 chimera containing the Ang1 loop sequence behaves functionally similarly to Ang1 as a constitutive Tie2 agonist, able to efficiently dissociate the inhibitory Tie1/Tie2 complex and elicit Tie2 clustering and downstream signaling.

  18. Influence of structure on de degradation with lacase mediator systems

    OpenAIRE

    Almansa, Eva; Andreas, Kandelbauer; Pereira, Luciana; Paulo, Artur Cavaco

    2004-01-01

    A new laccase was purified from Trametes hirsuta IMA2002. The laccase had a molecular mass of 62 kDa and an isoelectric point of pH 7. It had an optimum pH of 3.0 and an optimum temperature of 558C. The laccase was quite stable at 308C and pH 4.0 with a half-life of more than 100 hours. On ABTS, yringaldazide, and DMP the laccase showed KM and Kcat values of 75, 12 and 37 mM and 64, 83 and 54 s_1, respectively. The structurally diverse commercial dyes Indigo Carmine, Lanaset Blue 2R, Diamond ...

  19. Structural topography-mediated high temperature wetting symmetry breaking

    CERN Document Server

    Li, Jing; Liu, Yahua; Hao, Chonglei; Li, Minfei; Chaudhury, Manoj K; Yao, Shuhuai

    2015-01-01

    Directed motion of liquid droplets is of considerable importance in various industrial processes. Despite extensive advances in this field of research, our understanding and the ability to control droplet dynamics at high temperature remain limited, in part due to the emergence of complex wetting states intertwined by the phase change process at the triple-phase interfaces. Here we show that two concurrent wetting states (Leidenfrost and contact boiling) can be manifested in a single droplet above its boiling point rectified by the presence of asymmetric textures. The breaking of the wetting symmetry at high temperature subsequently leads to the preferential motion towards the region with higher heat transfer coefficient. We demonstrate experimentally and analytically that the droplet vectoring is intricately dependent on the interplay between the structural topography and its imposed thermal state. Our fundamental understanding and the ability to control the droplet dynamics at high temperature represent an ...

  20. Structural insight into magnetochrome-mediated magnetite biomineralization

    Science.gov (United States)

    Siponen, Marina I.; Legrand, Pierre; Widdrat, Marc; Jones, Stephanie R.; Zhang, Wei-Jia; Chang, Michelle C. Y.; Faivre, Damien; Arnoux, Pascal; Pignol, David

    2013-10-01

    Magnetotactic bacteria align along the Earth's magnetic field using an organelle called the magnetosome, a biomineralized magnetite (Fe(II)Fe(III)2O4) or greigite (Fe(II)Fe(III)2S4) crystal embedded in a lipid vesicle. Although the need for both iron(II) and iron(III) is clear, little is known about the biological mechanisms controlling their ratio. Here we present the structure of the magnetosome-associated protein MamP and find that it is built on a unique arrangement of a self-plugged PDZ domain fused to two magnetochrome domains, defining a new class of c-type cytochrome exclusively found in magnetotactic bacteria. Mutational analysis, enzyme kinetics, co-crystallization with iron(II) and an in vitro MamP-assisted magnetite production assay establish MamP as an iron oxidase that contributes to the formation of iron(III) ferrihydrite eventually required for magnetite crystal growth in vivo. These results demonstrate the molecular mechanisms of iron management taking place inside the magnetosome and highlight the role of magnetochrome in iron biomineralization.

  1. Testing Mediation in Structural Equation Modeling: The Effectiveness of the Test of Joint Significance

    Science.gov (United States)

    Leth-Steensen, Craig; Gallitto, Elena

    2016-01-01

    A large number of approaches have been proposed for estimating and testing the significance of indirect effects in mediation models. In this study, four sets of Monte Carlo simulations involving full latent variable structural equation models were run in order to contrast the effectiveness of the currently popular bias-corrected bootstrapping…

  2. Landscape structure mediates the effects of a stressor on field vole populations

    DEFF Research Database (Denmark)

    Dalkvist, Trine; Sibly, Richard M.; Topping, Christopher John

    2013-01-01

    Spatio-temporal landscape heterogeneity has rarely been considered in population-level impact assessments. Here we test whether landscape heterogeneity is important by examining the case of a pesticide applied seasonally to orchards which may affect non-target vole populations, using a validated...... results show that accurate prediction of population impact cannot be achieved without taking account of landscape structure. The specifics of landscape structure and habitat connectivity are likely always important in mediating the effects of stressors....

  3. Structural Waters Define a Functional Channel Mediating Activation of the GPCR, rhodopsin

    Energy Technology Data Exchange (ETDEWEB)

    Angel, T.; Gupta, S; Jastrzebska, B; Palczewski, K; Chance, M

    2009-01-01

    Structural water molecules may act as prosthetic groups indispensable for proper protein function. In the case of allosteric activation of G protein-coupled receptors (GPCRs), water likely imparts structural plasticity required for agonist-induced signal transmission. Inspection of structures of GPCR superfamily members reveals the presence of conserved embedded water molecules likely important to GPCR function. Coupling radiolytic hydroxyl radical labeling with rapid H2O18 solvent mixing, we observed no exchange of these structural waters with bulk solvent in either ground state or for the Meta II or opsin states. However, the radiolysis approach permitted labeling of selected side chain residues within the transmembrane helices and revealed activation-induced changes in local structural constraints likely mediated by dynamics of both water and protein. These results suggest both a possible general mechanism for water-dependent communication in family A GPCRs based on structural conservation, and a strategy for probing membrane protein structure.

  4. Synthesis of antibacterial silver-based nanodisks and dendritic structures mediated by royal jelly

    OpenAIRE

    Mendoza-Reséndez, R.; Gómez-Treviño, A.; Barriga-Castro, E.D.; Núñez, Nuria O.; Luna, C.

    2014-01-01

    The one-step preparation of silver nanoparticles and dendritic structures mediated by aqueous royal jelly solutions has been investigated for the first time. It has been found that royal jelly (RJ) is a complex organic matrix that can be simultaneously used as a reducing and stabilizing agent in the chemical synthesis of colloidal silver-based nanostructures from aqueous AgNO3 solutions, without the requirement of additional reagents or heating sources to initiate the oxidation-reduction reac...

  5. Long-term changes in corneal structure and tear inflammatory mediators after orthokeratology and LASIK

    OpenAIRE

    González-Pérez, Javier; Villa-Collar, César; González-Méijome, José Manuel; Garcia-Porta, Nery; Parafita, Manuel A.

    2012-01-01

    PURPOSE: To monitor changes in corneal structure and level of inflammatory mediators in tears of myopic patients following orthokeratology (OK) and laser in situ keratomileusis (LASIK). METHODS: Sixty-two myopic subjects were analyzed in this prospective study. Thirty-two had worn Paragon CRT contact lenses and 30 underwent standard LASIK. Thirty-two control subjects were also recruited. Pachometry and corneal topography were performed 12 months after both interventions. Tears were collec...

  6. Mannosyl Glycodendritic Structure Inhibits DC-SIGN-Mediated Ebola Virus Infection in cis and in trans

    Science.gov (United States)

    Lasala, Fátima; Arce, Eva; Otero, Joaquín R.; Rojo, Javier; Delgado, Rafael

    2003-01-01

    We have designed a glycodendritic structure, BH30sucMan, that blocks the interaction between dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) and Ebola virus (EBOV) envelope. BH30sucMan inhibits DC-SIGN-mediated EBOV infection at nanomolar concentrations. BH30sucMan may counteract important steps of the infective process of EBOV and, potentially, of microorganisms shown to exploit DC-SIGN for cell entry and infection. PMID:14638512

  7. Regulatory Focus as a Mediator of the Influence of Initiating Structure and Servant Leadership on Employee Behavior

    Science.gov (United States)

    Neubert, Mitchell J.; Kacmar, K. Michele; Carlson, Dawn S.; Chonko, Lawrence B.; Roberts, James A.

    2008-01-01

    In this research, the authors test a model in which the regulatory focus of employees at work mediates the influence of leadership on employee behavior. In a nationally representative sample of 250 workers who responded over 2 time periods, prevention focus mediated the relationship of initiating structure to in-role performance and deviant…

  8. Forest stand structure, productivity, and age mediate climatic effects on aspen decline

    Science.gov (United States)

    Bell, David M.; Bradford, John B.; Lauenroth, William K.

    2014-01-01

    Because forest stand structure, age, and productivity can mediate the impacts of climate on quaking aspen (Populus tremuloides) mortality, ignoring stand-scale factors limits inference on the drivers of recent sudden aspen decline. Using the proportion of aspen trees that were dead as an index of recent mortality at 841 forest inventory plots, we examined the relationship of this mortality index to forest structure and climate in the Rocky Mountains and Intermountain Western United States. We found that forest structure explained most of the patterns in mortality indices, but that variation in growing-season vapor pressure deficit and winter precipitation over the last 20 years was important. Mortality index sensitivity to precipitation was highest in forests where aspen exhibited high densities, relative basal areas, quadratic mean diameters, and productivities, whereas sensitivity to vapor pressure deficit was highest in young forest stands. These results indicate that the effects of drought on mortality may be mediated by forest stand development, competition with encroaching conifers, and physiological vulnerabilities of large trees to drought. By examining mortality index responses to both forest structure and climate, we show that forest succession cannot be ignored in studies attempting to understand the causes and consequences of sudden aspen decline.

  9. 三苯氧胺与遗传性BRCA1和BRCA2基因突变妇女乳腺癌的发病率国家乳腺和肠道外科辅助治疗计划(NSABP-P1)乳腺癌预防试验%Tamoxifen and Breast Cancer Incidence Among Women With Inherited Mutations in BRCA1 and BRCA2 National Surgical Adjuvant Breast and Bowel Project (NSABP-P1) Breast Cancer Prevention Trial

    Institute of Scientific and Technical Information of China (English)

    Mary-Claire King; Joseph Costantino; Lawrence Wickerham; Norman Wolmark; Bernard Fisher; Sam Wieand; Kathryn Hale; Ming Lee; Tom Walsh; Kelly Owens; Jonathan Tait; Lesli Ford; Barbara K. Dunn

    2002-01-01

    @@ 背景:对于年龄≥35岁、未患乳腺癌的妇女,应用三苯氧胺可以降低雌激素受体(ER)阳性乳腺癌的发生率,但是不能降低ER阴性乳腺癌的发生率.对于有BRCA1和BRCA2基因突变的极高危妇女,三苯氧胺对乳腺癌发生率的影响仍不明确.

  10. Novel peptide-mediated interactions derived from high-resolution 3-dimensional structures.

    Directory of Open Access Journals (Sweden)

    Amelie Stein

    2010-05-01

    Full Text Available Many biological responses to intra- and extracellular stimuli are regulated through complex networks of transient protein interactions where a globular domain in one protein recognizes a linear peptide from another, creating a relatively small contact interface. These peptide stretches are often found in unstructured regions of proteins, and contain a consensus motif complementary to the interaction surface displayed by their binding partners. While most current methods for the de novo discovery of such motifs exploit their tendency to occur in disordered regions, our work here focuses on another observation: upon binding to their partner domain, motifs adopt a well-defined structure. Indeed, through the analysis of all peptide-mediated interactions of known high-resolution three-dimensional (3D structure, we found that the structure of the peptide may be as characteristic as the consensus motif, and help identify target peptides even though they do not match the established patterns. Our analyses of the structural features of known motifs reveal that they tend to have a particular stretched and elongated structure, unlike most other peptides of the same length. Accordingly, we have implemented a strategy based on a Support Vector Machine that uses this features, along with other structure-encoded information about binding interfaces, to search the set of protein interactions of known 3D structure and to identify unnoticed peptide-mediated interactions among them. We have also derived consensus patterns for these interactions, whenever enough information was available, and compared our results with established linear motif patterns and their binding domains. Finally, to cross-validate our identification strategy, we scanned interactome networks from four model organisms with our newly derived patterns to see if any of them occurred more often than expected. Indeed, we found significant over-representations for 64 domain-motif interactions, 46 of

  11. Surface Mediated Structures: Stabilization of Metastable Polymorphs on the Example of Paracetamol

    Science.gov (United States)

    2014-01-01

    The preparation of typically thermodynamically unstable polymorphic structures is a challenge. However, solid surfaces are well established aids for the formation and stabilization of polymorphic structures within, for instance, organic electronics. In this study, we report the stabilization of a pharmaceutically relevant substance via a solid surface at ambient conditions. Form III of paracetamol, which is typically unstable in the bulk at standard conditions, can be stabilized with a model silica surface by a standard spin coating procedure followed by rapid heat treatment. Such a preparation technique allows the use of atomic force microscopy and grazing incidence X-ray diffraction measurements revealing detailed information on the morphology and structure of the polymorph. Furthermore, the results exhibit that this polymorph is stable over a long period of time revealing surface mediated stabilization. These findings demonstrate a novel approach to provide thermodynamic stability when applied to similar molecules with specific applications. PMID:25126023

  12. Detailed analysis of water structure in a solvent mediated electron tunneling mechanism

    International Nuclear Information System (INIS)

    This work aims at describing the water structure characteristics that influence the electron transfer superexchange mechanism by explicitly calculating the solvent mediated conductance between the donor and acceptor in a generic pair. The method employed here is based on the non-equilibrium Green function formalism for calculating the conductance over solvent trajectories previously determined by molecular dynamics methods. A non-exponential dependence of the conductance is observed with respect to the distance between the donor and the acceptor. Local fluctuations of the solvent structure are responsible for the non-monotonic dependence, mainly due to the formation of solvent bridges that act as a molecular wire connecting the sites. This shortcutting phenomenon is observed for certain ranges of distances between the donor and acceptor in the pair. Charge on the sites strongly affects the local solvent structure and causes qualitative changes in the distance dependence of the tunneling probability.

  13. Insight into structure dynamics of soil microbiota mediated by the richness of replanted Pseudostellaria heterophylla.

    Science.gov (United States)

    Zhao, Yong-Po; Lin, Sheng; Chu, Leixia; Gao, JiangTao; Azeem, Saadia; Lin, Wenxiong

    2016-01-01

    Consecutive monoculture of crops causes serious diseases and significant decline in yield and quality, and microbes in the rhizosphere are closely linked with plant health. Here we systematically studied the structure dynamics of soil microbiota in the monocropping system of Pseudostellaria heterophlla. The results illustrated that the successive cropping of P. heterophylla shifts the diversity and structure of microbial community in rhizosphere soil of P. heterophylla, showing that the diversity of microbial community in rhizosphere soil of P. heterophylla was decreased with the increase of planting years while the structure of microbial community became more deteriorative. Moreover, the population size of typical pathogens increased and the beneficial bacterial population decreased with the increasing years of monoculture, which resulted in the microecological imbalance in P. heterophylla rhizosphere, thereby caused serious replanting diseases in monocropping system. Our results suggested that structure dynamics of rhizosphere microbial communities were mediated by the richness of replanted P. heterophylla, and thus the replant disease result from the imbalanced microbial structure with a higher ratio of pathogens/beneficial bacteria in rhizosphere soil under monocropping regimes. This finding provides a clue to open a new avenue for modulating the root microbiome to enhance the crop production and sustainability. PMID:27188449

  14. Hemi-fused structure mediates and controls fusion and fission in live cells.

    Science.gov (United States)

    Zhao, Wei-Dong; Hamid, Edaeni; Shin, Wonchul; Wen, Peter J; Krystofiak, Evan S; Villarreal, Seth A; Chiang, Hsueh-Cheng; Kachar, Bechara; Wu, Ling-Gang

    2016-06-23

    Membrane fusion and fission are vital for eukaryotic life. For three decades, it has been proposed that fusion is mediated by fusion between the proximal leaflets of two bilayers (hemi-fusion) to produce a hemi-fused structure, followed by fusion between the distal leaflets, whereas fission is via hemi-fission, which also produces a hemi-fused structure, followed by full fission. This hypothesis remained unsupported owing to the lack of observation of hemi-fusion or hemi-fission in live cells. A competing fusion hypothesis involving protein-lined pore formation has also been proposed. Here we report the observation of a hemi-fused Ω-shaped structure in live neuroendocrine chromaffin cells and pancreatic β-cells, visualized using confocal and super-resolution stimulated emission depletion microscopy. This structure is generated from fusion pore opening or closure (fission) at the plasma membrane. Unexpectedly, the transition to full fusion or fission is determined by competition between fusion and calcium/dynamin-dependent fission mechanisms, and is notably slow (seconds to tens of seconds) in a substantial fraction of the events. These results provide key missing evidence in support of the hemi-fusion and hemi-fission hypothesis in live cells, and reveal the hemi-fused intermediate as a key structure controlling fusion and fission, as fusion and fission mechanisms compete to determine the transition to fusion or fission. PMID:27309816

  15. Linking Organizational Structure, Technological Support and Process Innovation: the Mediating Role of Knowledge Sharing in the Iraqi Textile Industry

    Directory of Open Access Journals (Sweden)

    Al-Mamoori Amal Ghalib Rashid

    2015-01-01

    Full Text Available This paper investigates the relationships among organizational structure, technological support, knowledge sharing and process innovation and whether knowledge sharing has a mediating effect on these relationships. Based on the survey among employees in the Iraqi textile industry, the results revealed that organizational structure and technological support positively and significantly influence knowledge sharing. Knowledge sharing was also found to be an important mediator between organizational structure, support technology and process innovation. The findings bear implications to the Iraqi government’s call for innovation in the Iraqi textile industry.

  16. Building Collaborative Structures for Teachers' Autonomy and Self-Efficacy: The Mediating Role of Participative Management and Learning Culture

    Science.gov (United States)

    Lu, Jiafang; Jiang, Xinhui; Yu, Huen; Li, Dongyu

    2015-01-01

    This study focused on the collaborative structure-building behavior of school principals and examined how such behavior affects teacher empowerment. More important, it tested the mediating effects of participative management and learning culture. By collecting nested data from 104 schools in Hong Kong and adopting multilevel structural equation…

  17. Water-mediated variability in the structure of relaxed-state haemoglobin

    International Nuclear Information System (INIS)

    Partial dehydration of high-salt horse methaemoglobin crystals tends to shift the structure from the R state to the R2 state, in agreement with previous observations that movements in the molecule resulting from changes in water content mimic those involved in protein action. The crystal structure of high-salt horse methaemoglobin has been determined at environmental relative humidities (r.h.) of 88, 79, 75 and 66%. The molecule is in the R state in the native and the r.h. 88% crystals. At r.h. 79%, the water content of the crystal is reduced and the molecule appears to move towards the R2 state. The crystals undergo a water-mediated transformation involving a doubling of one of the unit-cell parameters and an increase in water content when the environmental humidity is further reduced to r.h. 75%. The water content is now similar to that in the native crystals and the molecules are in the R state. The crystal structure at r.h. 66% is similar, but not identical, to that at r.h. 75%, but the solvent content is substantially reduced and the molecules have a quaternary structure that is in between those corresponding to the R and R2 states. Thus, variation in hydration leads to variation in the quaternary structure. Furthermore, partial dehydration appears to shift the structure from the R state to the R2 state. This observation is in agreement with the earlier conclusion that the changes in protein structure that accompany partial dehydration are similar to those that occur during protein action

  18. Uncovering molecular structural mechanisms of signaling mediated by the prion protein

    International Nuclear Information System (INIS)

    The glycosyl phosphatidylinositol (GPI) - anchored prion protein (PrPc), usually associated with neurodegenerative diseases, modulates various cellular responses and may scaffold multiprotein cell surface signaling complexes. Engagement of PrPc with the secretable cochaperone hop/STI 1 induces neurotrophic transmembrane signals through unknown molecular mechanisms. We addressed whether interaction of Pr Pc and hop STI 1 entails structural rearrangements relevant for signaling. Circular dichroism and fluorescence spectroscopy showed that PrPc:hop/STI 1 interaction triggers loss of PrP helical structures, involving at least a perturbation of the Pr Pc143-153 beta-helix. Novel SAXS models revealed a significant C-terminal compaction of hop/STI 1 when bound to PrPc. Differing from a recent dimeric model of human hop/STI 1, both size exclusion chromatography and SAXS data support a monomeric form of free murine hop/STI 1. Changes in the Pr Pc143-153 beta-helix may engage the transmembrane signaling protein laminin receptor precursor and neural cell adhesion molecule, both of which bind that domain of Pr Pc, and further ligands may be engaged by the tertiary structural changes of hop/STI 1. These reciprocal structural modifications indicate a versatile mechanism for signaling mediated by Pr Pc:hop/STI 1 interaction, consistent with the hypothesis that Pr Pc scaffolds multiprotein signaling complexes at the cell surface. (author)

  19. PLCγ-activated signalling is essential for TrkB mediated sensory neuron structural plasticity

    Directory of Open Access Journals (Sweden)

    Rocha-Sanchez Sonia M

    2010-10-01

    Full Text Available Abstract Background The vestibular system provides the primary input of our sense of balance and spatial orientation. Dysfunction of the vestibular system can severely affect a person's quality of life. Therefore, understanding the molecular basis of vestibular neuron survival, maintenance, and innervation of the target sensory epithelia is fundamental. Results Here we report that a point mutation at the phospholipase Cγ (PLCγ docking site in the mouse neurotrophin tyrosine kinase receptor TrkB (Ntrk2 specifically impairs fiber guidance inside the vestibular sensory epithelia, but has limited effects on the survival of vestibular sensory neurons and growth of afferent processes toward the sensory epithelia. We also show that expression of the TRPC3 cation calcium channel, whose activity is known to be required for nerve-growth cone guidance induced by brain-derived neurotrophic factor (BDNF, is altered in these animals. In addition, we find that absence of the PLCγ mediated TrkB signalling interferes with the transformation of bouton type afferent terminals of vestibular dendrites into calyces (the largest synaptic contact of dendrites known in the mammalian nervous system on type I vestibular hair cells; the latter are normally distributed in these mutants as revealed by an unaltered expression pattern of the potassium channel KCNQ4 in these cells. Conclusions These results demonstrate a crucial involvement of the TrkB/PLCγ-mediated intracellular signalling in structural aspects of sensory neuron plasticity.

  20. BRCA1 and BRCA2 Mutations

    Science.gov (United States)

    ... risk of cancer of the ovary , fallopian tube , peritoneum , and pancreas. Men who have a BRCA1 or ... one of the previous criteria? *Cancer of the peritoneum and fallopian tubes should be considered a part ...

  1. BRCA1 and BRCA2 gene testing

    Science.gov (United States)

    ... man's risk of eveloping: Breast cancer Pancreatic cancer Testicular cancer Prostate cancer Only about 5% of breast cancers ... Risk Assessment, Genetic Counseling, and Genetic Testing. U.S. Preventive Services Task Force Web site. Current as of ...

  2. A novel DNA computing model based on RecA-mediated triple-stranded DNA structure

    Institute of Scientific and Technical Information of China (English)

    Fang Gang; Zhang Shemin; Dong Yafei; Xu Jin

    2007-01-01

    The field of DNA computing emerged in 1994 after Adleman's paper was published. Henceforth, a few scholars solved some noted NP-complete problems in this way. And all these methods of DNA computing are based on conventional Watson-Crick hydrogen bond of doublehelical DNA molecule. In this paper, we show that the triple-stranded DNA structure mediated by RecA protein can be used for solving computational problems. Sequence-specific recognition of double-stranded DNA by oligonucleotide-directed triple helix (triplex) formation is used to carry out the algorithm. We present procedure for the 3-vertex-colorability problems. In our proposed procedure, it is suggested that it is possible to solve more complicated problems with more variables by this model.

  3. Structural and optical control of DNA-mediated Janus plasmonic nanostructures

    Science.gov (United States)

    Xu, Lifeng; Wang, Geng; Shen, Jianlei; Geng, Heping; Li, Wenqin; Wu, Longlong; Gao, Shanshan; Wang, Jianing; Wang, Lihua; Fan, Chunhai; Chen, Gang

    2016-04-01

    The broken symmetry of Janus nanostructures (JNs) provides a distinctive means to express drastically different chemical and physical characters within a single particle and acquire emergent properties usually inconceivable for homogeneous or symmetric nanostructures. In spite of their tremendous application potential, considerable challenges are encountered in identifying pathways to synthesize or assemble JNs with a controllable geometry and morphology. Here, we exploit the reverse process of growth, i.e. silver etching, to quantitatively control the structural and optical properties of the DNA-mediated Au-Ag JNs. The transmission electron microscopy and optical measurements, along with numerical simulations, present a comprehensive view of the etching dynamics and a detailed analysis of the influencing factors that provide handles for regulating the silver etching rate and progress. In addition, a novel type of composite JN is proposed and a model system is designed and engineered through dynamical control of the etching and DNA-hybridization processes.The broken symmetry of Janus nanostructures (JNs) provides a distinctive means to express drastically different chemical and physical characters within a single particle and acquire emergent properties usually inconceivable for homogeneous or symmetric nanostructures. In spite of their tremendous application potential, considerable challenges are encountered in identifying pathways to synthesize or assemble JNs with a controllable geometry and morphology. Here, we exploit the reverse process of growth, i.e. silver etching, to quantitatively control the structural and optical properties of the DNA-mediated Au-Ag JNs. The transmission electron microscopy and optical measurements, along with numerical simulations, present a comprehensive view of the etching dynamics and a detailed analysis of the influencing factors that provide handles for regulating the silver etching rate and progress. In addition, a novel type of

  4. Uncovering molecular structural mechanisms of signaling mediated by the prion protein

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Sebastian A.; Linden, Rafael [Universidade Federal do Rio de Janeiro (IBCCF/UFRl), RJ (Brazil). Inst. de Biofisica Carlos Chagas Filho; Cordeiro, Yraima; Rocha e Lima, Luis M.T. da [Universidade Federal do Rio de Janeiro (FF/UFRl), RJ (Brazil). Fac. de Farmacia; Lopes, Marilene H. [Instituto Ludwig de Pesquisa de Cancer, Sao Paulo, SP (Brazil); Silva, Jerson L.; Foguel, Debora [Universidade Federal do Rio de Janeiro (IBqM/UFRl), RJ (Brazil). Inst. de Bioquimica Medica

    2009-07-01

    The glycosyl phosphatidylinositol (GPI) - anchored prion protein (PrP{sup c}), usually associated with neurodegenerative diseases, modulates various cellular responses and may scaffold multiprotein cell surface signaling complexes. Engagement of PrP{sup c} with the secretable cochaperone hop/STI 1 induces neurotrophic transmembrane signals through unknown molecular mechanisms. We addressed whether interaction of Pr P{sup c} and hop STI 1 entails structural rearrangements relevant for signaling. Circular dichroism and fluorescence spectroscopy showed that PrP{sup c}:hop/STI 1 interaction triggers loss of PrP helical structures, involving at least a perturbation of the Pr P{sup c}{sub 143-153} beta-helix. Novel SAXS models revealed a significant C-terminal compaction of hop/STI 1 when bound to PrP{sup c}. Differing from a recent dimeric model of human hop/STI 1, both size exclusion chromatography and SAXS data support a monomeric form of free murine hop/STI 1. Changes in the Pr P{sup c}{sub 143-153} beta-helix may engage the transmembrane signaling protein laminin receptor precursor and neural cell adhesion molecule, both of which bind that domain of Pr P{sup c}, and further ligands may be engaged by the tertiary structural changes of hop/STI 1. These reciprocal structural modifications indicate a versatile mechanism for signaling mediated by Pr P{sup c}:hop/STI 1 interaction, consistent with the hypothesis that Pr P{sup c} scaffolds multiprotein signaling complexes at the cell surface. (author)

  5. Transcriptional regulation mechanism mediated by miRNA-DNA•DNA triplex structure stabilized by Argonaute.

    Science.gov (United States)

    Toscano-Garibay, Julia D; Aquino-Jarquin, Guillermo

    2014-11-01

    Transcription regulation depends on interactions between repressor or activator proteins with promoter sequences, while post-transcriptional regulation typically relies on microRNA (miRNA) interaction with sequences in 5' and 3'-Untranslated regions (UTRs) of messenger RNA (mRNA). However, several pieces of evidence suggest that miRNA:Argonaute (AGO) complexes may also suppress transcription through RNA interference (RNAi) components and epigenetic mechanisms. However, recent observations suggest that miRNA-induced transcriptional silencing could be exerted by an unknown mechanism independent of chromatin modifiers. The RNA-DNA•DNA triplex structure has emerged as an important RNA tertiary motif in which successive non-canonical base pairs form between a DNA-DNA duplex and a third strand. Frequently, promoters have Purine (PU)-rich tracts, and some Triplex-forming oligonucleotides (TFOs) targeting these regulatory regions have been shown to inhibit transcription selectively. Here, we summarize observations suggesting that miRNAs exert regulation over promoter regions through miRNA-DNA•DNA triplex structure formation stabilized by AGO proteins which represents a plausible model of RNA-mediated Transcriptional gene silencing (TGS). PMID:25086339

  6. Oxidative Conversion Mediates Antiproliferative Effects of tert-Butylhydroquinone: Structure and Activity Relationship Study.

    Science.gov (United States)

    Sanidad, Katherine Z; Sukamtoh, Elvira; Wang, Weicang; Du, Zheyuan; Florio, Ellie; He, Lili; Xiao, Hang; Decker, Eric A; Zhang, Guodong

    2016-05-18

    Previous studies have shown that tert-butylhydroquinone (TBHQ), a widely used food antioxidant, has cytotoxic effects at high doses; however, the underlying mechanisms are not well understood. Here, we found that the effects of TBHQ on cell proliferation, cell cycle progression, and apoptosis are mainly mediated by its oxidative conversion to a quinone metabolite tert-butylquinone (TBQ). Co-addition of cupric ion (Cu(2+)) caused accelerated oxidative conversion of TBHQ to TBQ and enhanced the biological activities of TBHQ on cell proliferation, cell cycle progression, and apoptosis in MC38 colon cancer cells. In contrast, co-addition of ethylenediaminetetraacetic acid (EDTA) suppressed TBHQ oxidation and inhibited the biological activities of TBHQ in MC38 cells. For example, after 24 h of treatment in basal medium, low-dose TBHQ (1.88-7.5 μM) had little effect on MC38 cell proliferation, while co-addition of 50 μM Cu(2+) caused 30-70% inhibition of cell proliferation; in contrast, treatment with high-dose TBHQ (15 μM) inhibited 50 ± 4% MC38 proliferation, which was abolished by co-addition of 50 μM EDTA. We further showed that TBQ had more potent actions on cell proliferation and associated cellular responses than TBHQ, supporting a critical role of TBQ formation in the biological activities of TBHQ. Finally, a structure and activity relationship study showed that the fast-oxidized para-hydroquinones had potent antiproliferative effects in MC38 cells, while the slow-oxidized para-hydroquinones had weak or little biological activities. Together, these results suggest that the biological activities of TBHQ and other para-hydroquinones are mainly mediated by their oxidative metabolism to generate more biologically active quinone metabolites. PMID:27111399

  7. Lower Level Mediation Effect Analysis in Two-Level Studies: A Note on a Multilevel Structural Equation Modeling Approach

    Science.gov (United States)

    Raykov, Tenko; Mels, Gerhard

    2007-01-01

    This article presents a didactic discussion of a multilevel covariance structure modeling approach to estimation of lowest level mediation effect indexes in two-level studies. The procedure is useful when addressing questions about relations among total and indirect effects between variables of interest while accounting for the hierarchical…

  8. Parent-Child Relations and Peer Associations as Mediators of the Family Structure--Substance Use Relationship

    Science.gov (United States)

    Crawford, Lizabeth A.; Novak, Katherine B.

    2008-01-01

    Using data from the National Education Longitudinal Survey of 1988, the authors assess the extent to which adolescents' levels of parental attachment and opportunities for participating in delinquent activities mediate the family structure--substance use relationship. A series of hierarchical regressions supported the hypotheses that high levels…

  9. The Impact of Structural Empowerment on Organizational Citizenship Behavior-Organization and Job Performance: A Mediating Role of Burnout

    OpenAIRE

    Hina Jaffery; Hassan Farooq

    2015-01-01

    The banking sector employees are usually exposed to potential job burnout which impacts their employee performance. This study examined the impact of structural empowerment on organizational citizenship behavior-organization (henceforth, OCBO) and job performance and further examined the mediating effect of job burnout in the relationships of structural empowerment, OCBO and job performance. In this study, data from 282 employees was taken from four banks: both public and private sectors. Two...

  10. The Impact of Structural Empowerment on Organizational Citizenship Behavior-Organization and Job Performance: A Mediating Role of Burnout

    Directory of Open Access Journals (Sweden)

    Hina Jaffery

    2015-10-01

    Full Text Available The banking sector employees are usually exposed to potential job burnout which impacts their employee performance. This study examined the impact of structural empowerment on organizational citizenship behavior-organization (henceforth, OCBO and job performance and further examined the mediating effect of job burnout in the relationships of structural empowerment, OCBO and job performance. In this study, data from 282 employees was taken from four banks: both public and private sectors. Two stage sampling technique was carried out to collect data. In the first stage probability cluster sampling and in the second stage convenience sampling was used. Different data analysis techniques like correlation, regression analysis, were used to test the four hypotheses of the study. Findings show that there are strong positive relationships of structural empowerment with OCBO and job performance. It has also proved that job burnout strongly mediates the relationship of structural empowerment and organizational citizenship-behavior (OCBO and weakly mediates the relationship between structural empowerment and job performance. The findings would help the HR executives of the organizations to formulate future development to combat the burnout and ensure effective overall performance of employees through structurally empowering them.

  11. Structurally novel steroidal spirooxindole by241 potently inhibits tumor growth mainly through ROS-mediated mechanisms.

    Science.gov (United States)

    Shi, Xiao-Jing; Yu, Bin; Wang, Jun-Wei; Qi, Ping-Ping; Tang, Kai; Huang, Xin; Liu, Hong-Min

    2016-01-01

    Cancer cells always have increased ROS levels, thus making them more vulnerable to persistent endogenous oxidative stress. The biochemical difference between cancer and normal cells could be exploited to achieve selective cancer cell killing by exogenous ROS-producing agents. Herein we described a structurally novel steroidal spirooxindole by241 and its anticancer efficacy. By241 exhibited potent inhibition against human cancer cells and less toxic to normal cells. By241 concentration-dependently induced apoptosis of MGC-803 and EC9706 cells, accompanied with the mitochondrial dysfunction and increased ROS levels. NAC can completely restore the decreased cell viability of MGC-803 cells caused by by241, suggesting ROS-mediated mechanisms. The expression levels of proteins involved in the mitochondrion-related pathways were detected, showing increased expression of proapoptotic proteins and decreased expression of anti-apoptotic proteins, and activation of caspases-9/-3, but without activating caspase-8 expression. Pretreatment with Z-VAD-FMK partially rescued by241-induced apoptosis of MGC-803 cells. Additionally, by241 inhibited mTOR, activated p53 and its downstream proteins, cleaved MDM2 and PI3K/AKT as well as NF-κB signaling pathway. In vivo experiments showed that by241 did not have significant acute oral toxicity and exerted good anticancer efficacy against MGC-803 bearing mice models. Therefore, by241 may serve as a lead for further development for cancer therapy. PMID:27527552

  12. Ability of structurally diverse natural products and synthetic chemicals to induce gene expression mediated by estrogen receptors from various species.

    Science.gov (United States)

    Matthews, J B; Fertuck, K C; Celius, T; Huang, Y-W; Fong, C J; Zacharewski, T R

    2002-10-01

    The ability of 14 structurally diverse estrogenic compounds to induce reporter gene expression mediated by estrogen receptors (ERs) from different species was examined. MCF-7 cells were transiently transfected with a Gal4-regulated luciferase reporter gene (17m5-G-Luc) and Gal4-ER chimeric receptors containing the D, E and F domains of the human alpha (Gal4-hERalphadef), mouse alpha (Gal4-mERalphadef), mouse beta (Gal4-mERbetadef), chicken (Gal4-cERalphadef), green anole (Gal4-aERalphadef), Xenopus (Gal4-xERdef) or rainbow trout alpha ERs (Gal4-rtERalphadef). The efficacy of 17beta-estradiol (E2) in inducing reporter gene expression was similar among the different constructs overall, with EC(50) values ranging from 0.05 to 0.7nM. However, Gal4-rtERalphadef had an EC(50) value at 37 degrees C of 28nM, though at 20 degrees C an EC(50) value of 1nM was observed. Despite a similar response to E2 treatment among the ERs, many differences were observed in the magnitude of the response to other structurally diverse chemicals. For example, coumestrol induced Gal4-mERbetadef- and Gal4-aERdef-mediated reporter gene expression 164- and 8-fold greater, respectively, than mediated with the other Gal4-ERs. As well, in contrast to results with other Gal4-ERs, alpha-zearalenol consistently induced Gal4-rtERalphadef-mediated reporter gene activity at lower concentrations than did E2. Overall, the results demonstrate that selected estrogenic compounds exhibit a differential ability to induce reporter gene activity mediated by ERs from different vertebrate species. These data also highlight the importance of incubation temperature when examining rtERalpha-mediated activity. PMID:12477484

  13. Parental Attachment, Separation-Individuation, and College Student Adjustment: A Structural Equation Analysis of Mediational Effects

    Science.gov (United States)

    Mattanah, Jonathan F.; Hancock, Gregory R.; Brand, Bethany L.

    2004-01-01

    Secure parental attachment and healthy levels of separation-individuation have been consistently linked to greater college student adjustment. The present study proposes that the relation between parental attachment and college adjustment is mediated by healthy separation-individuation. The authors gathered data on maternal and paternal…

  14. Structure of the Membrane-tethering GRASP Domain Reveals a Unique PDZ Ligand Interaction That Mediates Golgi Biogenesis

    Energy Technology Data Exchange (ETDEWEB)

    S Truschel; D Sengupta; A Foote; A Heroux; M Macbeth; A Linstedt

    2011-12-31

    Biogenesis of the ribbon-like membrane network of the mammalian Golgi requires membrane tethering by the conserved GRASP domain in GRASP65 and GRASP55, yet the tethering mechanism is not fully understood. Here, we report the crystal structure of the GRASP55 GRASP domain, which revealed an unusual arrangement of two tandem PDZ folds that more closely resemble prokaryotic PDZ domains. Biochemical and functional data indicated that the interaction between the ligand-binding pocket of PDZ1 and an internal ligand on PDZ2 mediates the GRASP self-interaction, and structural analyses suggest that this occurs via a unique mode of internal PDZ ligand recognition. Our data uncover the structural basis for ligand specificity and provide insight into the mechanism of GRASP-dependent membrane tethering of analogous Golgi cisternae.

  15. Structure of the Membrane-tethering GRASP Domain Reveals a Unique PDZ Ligand Interaction That Mediates Golgi Biogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Truschel, S.T.; Heroux, A.; Sengupta, D.; Foote, A.; Macbeth, M. R.; Linstedt, A. D.

    2011-06-10

    Biogenesis of the ribbon-like membrane network of the mammalian Golgi requires membrane tethering by the conserved GRASP domain in GRASP65 and GRASP55, yet the tethering mechanism is not fully understood. Here, we report the crystal structure of the GRASP55 GRASP domain, which revealed an unusual arrangement of two tandem PDZ folds that more closely resemble prokaryotic PDZ domains. Biochemical and functional data indicated that the interaction between the ligand-binding pocket of PDZ1 and an internal ligand on PDZ2 mediates the GRASP self-interaction, and structural analyses suggest that this occurs via a unique mode of internal PDZ ligand recognition. Our data uncover the structural basis for ligand specificity and provide insight into the mechanism of GRASP-dependent membrane tethering of analogous Golgi cisternae.

  16. Mechanisms of Lin28-Mediated miRNA and mRNA Regulation—A Structural and Functional Perspective

    Directory of Open Access Journals (Sweden)

    Udo Heinemann

    2013-08-01

    Full Text Available Lin28 is an essential RNA-binding protein that is ubiquitously expressed in embryonic stem cells. Its physiological function has been linked to the regulation of differentiation, development, and oncogenesis as well as glucose metabolism. Lin28 mediates these pleiotropic functions by inhibiting let-7 miRNA biogenesis and by modulating the translation of target mRNAs. Both activities strongly depend on Lin28’s RNA-binding domains (RBDs, an N-terminal cold-shock domain (CSD and a C-terminal Zn-knuckle domain (ZKD. Recent biochemical and structural studies revealed the mechanisms of how Lin28 controls let-7 biogenesis. Lin28 binds to the terminal loop of pri- and pre-let-7 miRNA and represses their processing by Drosha and Dicer. Several biochemical and structural studies showed that the specificity of this interaction is mainly mediated by the ZKD with a conserved GGAGA or GGAGA-like motif. Further RNA crosslinking and immunoprecipitation coupled to high-throughput sequencing (CLIP-seq studies confirmed this binding motif and uncovered a large number of new mRNA binding sites. Here we review exciting recent progress in our understanding of how Lin28 binds structurally diverse RNAs and fulfills its pleiotropic functions.

  17. Minimum structural requirements for cell membrane leakage-mediated anti-MRSA activity of macrocyclic bis(bibenzyl)s.

    Science.gov (United States)

    Fujii, Kana; Morita, Daichi; Onoda, Kenji; Kuroda, Teruo; Miyachi, Hiroyuki

    2016-05-01

    Macrocyclic bis(bibenzyl)-type phenolic natural products, found exclusively in bryophytes, exhibit potent antibacterial activity towards methicillin-resistant Staphylococcus aureus (anti-MRSA activity). Here, in order to identify the minimum essential structure for cell membrane leakage-mediated anti-MRSA activity of these compounds, we synthesized acyclic fragment structures and evaluated their anti-MRSA activity. The activities of all of the acyclic fragments tested exhibited similar characteristics to those of the macrocycles, i.e., anti-MRSA bactericidal activity, an enhancing effect on influx and efflux of ethidium bromide (EtBr: fluorescent DNA-binder) in Staphylococcus aureus cells, and bactericidal activity towards a Staphylococcus aureus strain resistant to 2-phenoxyphenol (4). The latter result suggests that they have a different mechanism of action from 4, which is a FabI inhibitor previously proposed to be the minimum active fragment of riccardin-type macrocycles. Thus, cyclic structure is not a necessary condition for cell membrane leakage-mediated anti-MRSA activity of macrocyclic bis(bibenzyl)s. PMID:26995530

  18. The Augmented Cognitive Mediation Model: Examining Antecedents of Factual and Structural Breast Cancer Knowledge Among Singaporean Women.

    Science.gov (United States)

    Lee, Edmund W J; Shin, Mincheol; Kawaja, Ariffin; Ho, Shirley S

    2016-05-01

    As knowledge acquisition is an important component of health communication research, this study examines factors associated with Singaporean women's breast cancer knowledge using an augmented cognitive mediation model. We conducted a nationally representative study that surveyed 802 women between the ages of 30 and 70 using random-digit dialing. The results supported the augmented cognitive mediation model, which proposes the inclusion of risk perception as a motivator of health information seeking and structural knowledge as an additional knowledge dimension. There was adequate support for the hypothesized paths in the model. Risk perception was positively associated with attention to newspaper, television, Internet, and interpersonal communication. Attention to the three media channels was associated with interpersonal communication, but only newspaper and television attention were associated with elaboration. Interpersonal communication was positively associated with structural knowledge, whereas elaboration was associated with both factual and structural knowledge. Differential indirect effects between media attention and knowledge dimensions via interpersonal communication and elaboration were found. Theoretical and practical implications are discussed. PMID:27128006

  19. RNA Structures as Mediators of Neurological Diseases and as Drug Targets.

    Science.gov (United States)

    Bernat, Viachaslau; Disney, Matthew D

    2015-07-01

    RNAs adopt diverse folded structures that are essential for function and thus play critical roles in cellular biology. A striking example of this is the ribosome, a complex, three-dimensionally folded macromolecular machine that orchestrates protein synthesis. Advances in RNA biochemistry, structural and molecular biology, and bioinformatics have revealed other non-coding RNAs whose functions are dictated by their structure. It is not surprising that aberrantly folded RNA structures contribute to disease. In this Review, we provide a brief introduction into RNA structural biology and then describe how RNA structures function in cells and cause or contribute to neurological disease. Finally, we highlight successful applications of rational design principles to provide chemical probes and lead compounds targeting structured RNAs. Based on several examples of well-characterized RNA-driven neurological disorders, we demonstrate how designed small molecules can facilitate the study of RNA dysfunction, elucidating previously unknown roles for RNA in disease, and provide lead therapeutics. PMID:26139368

  20. Structural Reproduction of Social Networks in Computer-Mediated Communication Forums

    Science.gov (United States)

    Stefanone, M. A.; Gay, G.

    2008-01-01

    This study explores the relationship between the structure of an existing social network and the structure of an emergent discussion-board network in an undergraduate university class. Thirty-one students were issued with laptop computers that remained in their possession for the duration of the semester. While using these machines, participants'…

  1. Spontaneous structuration in coacervate-based protocells by polyoxometalate-mediated membrane assembly.

    Science.gov (United States)

    Williams, David S; Patil, Avinash J; Mann, Stephen

    2014-05-14

    Molecularly crowded, polyelectrolyte/ribonucleotide-enriched membrane-free coacervate droplets are transformed into membrane-bounded sub-divided vesicles by using a polyoxometalate-mediated surface-templating procedure. The coacervate to vesicle transition results in reconstruction of the coacervate micro-droplets into novel three-tiered micro-compartments comprising a semi-permeable negatively charged polyoxometalate/polyelectrolyte outer membrane, a sub-membrane coacervate shell, and an internal aqueous lumen. We demonstrate that organic dyes, ssDNA, magnetic nanoparticles and enzymes can be concentrated into the interior of the micro-compartments by sequestration into the coacervate micro-droplets prior to vesicle formation. The vesicle-encapsulated proteins are inaccessible to proteases in the external medium, and can be exploited for the spatial localization and coupling of two-enzyme cascade reactions within single or between multiple populations of hybrid vesicles dispersed in aqueous media. PMID:24515342

  2. Impacts of pH-mediated EPS structure on probiotic bacterial pili-whey proteins interactions.

    Science.gov (United States)

    Burgain, Jennifer; Scher, Joel; Lebeer, Sarah; Vanderleyden, Jos; Corgneau, Magda; Guerin, Justine; Caillet, Céline; Duval, Jérôme F L; Francius, Gregory; Gaiani, Claire

    2015-10-01

    Probiotic bacteria are routinely incorporated into dairy foods because of the health benefits they can provide when consumed. In this work, the marked pH-dependence of the pili/EPS organization at the outer surface of Lactobacillus rhamnosus GG is characterized in detail by Single Cell Force Microscopy and cell electrophoretic mobility measurements analyzed according to formalisms for nanomechanical contact and soft particle electrokinetics, respectively. At pH 6.8, LGG pili are easily accessible by AFM tips functionalized with whey proteins for specific binding, while at pH 4.8 the collapsed EPS surface layer significantly immobilized the LGG pili. This resulted in their reduced accessibility to the specific whey-coated AFM tip, and to stronger whey protein-pili rupture forces. Thus, pili interactions with whey proteins are screened to an extent that depends on the pH-mediated embedment of the pili within the EPS layer. PMID:26209966

  3. Crystal Structure of Cu/Zn Superoxide Dismutase from Taenia Solium Reveals Metal-mediated Self-assembly

    Energy Technology Data Exchange (ETDEWEB)

    A Hernandez-Santoyo; A Landa; E Gonzalez-Mondragon; M Pedraza-Escalona; R Parra-Unda; A Rodriguez-Romero

    2011-12-31

    Taenia solium is the cestode responsible for porcine and human cysticercosis. The ability of this parasite to establish itself in the host is related to its evasion of the immune response and its antioxidant defence system. The latter includes enzymes such as cytosolic Cu/Zn superoxide dismutase. In this article, we describe the crystal structure of a recombinant T. solium Cu/Zn superoxide dismutase, representing the first structure of a protein from this organism. This enzyme shows a different charge distribution at the entrance of the active channel when compared with human Cu/Zn superoxide dismutase, giving it interesting properties that may allow the design of specific inhibitors against this cestode. The overall topology is similar to other superoxide dismutase structures; however, there are several His and Glu residues on the surface of the protein that coordinate metal ions both intra- and intermolecularly. Interestingly, one of these ions, located on the {beta}2 strand, establishes a metal-mediated intermolecular {beta}-{beta} interaction, including a symmetry-related molecule. The factors responsible for the abnormal protein-protein interactions that lead to oligomerization are still unknown; however, high metal levels have been implicated in these phenomena, but exactly how they are involved remains unclear. The present results suggest that this structure could be useful as a model to explain an alternative mechanism of protein aggregation commonly observed in insoluble fibrillar deposits.

  4. Soil development mediated by traditional practices shape the stand structure of Spanish juniper woodland

    OpenAIRE

    Javier de la Fuente-Leon; Edgar Lafuente-Jimenez; Daphne Hermosilla; Miguel Broto-Cartagena; Antonio Gasco

    2014-01-01

    Aim of study: Assessing the effect of soil development on the stand structure of a Spanish juniper forest traditionally shaped by livestock browsing and wood extraction. Area of study: Berlanga de Duero (Soria, Castilla y León), Spain.Material and Methods: A stand inventory served to record stand structure. Tree age, height, DBH, basal area, and overbark volume were determined in each plot. Results were pooled considering two well-differentiated degrees of soil evolution. One-way ANOVAs (and ...

  5. Molecular Structure, Function, and Dynamics of Clathrin-Mediated Membrane Traffic

    OpenAIRE

    Kirchhausen, Tom; Owen, David; Harrison, Stephen C.

    2014-01-01

    Clathrin is a molecular scaffold for vesicular uptake of cargo at the plasma membrane, where its assembly into cage-like lattices underlies the clathrin-coated pits of classical endocytosis. This review describes the structures of clathrin, major cargo adaptors, and other proteins that participate in forming a clathrin-coated pit, loading its contents, pinching off the membrane as a lattice-enclosed vesicle, and recycling the components. It integrates as much of the structural information as ...

  6. Structure-Property-Transfection Relationships in Polycation-mediated Non-viral DNA Delivery

    OpenAIRE

    Layman, John

    2008-01-01

    Non-viral gene delivery agents, such as cationic polyelectrolytes, are attractive replacements to viruses due to the absence of potential immunogenic risk and the ability to tune their macromolecular structure. Although non-viral vectors possess numerous design advantages, several investigators have shown that transfer efficiencies are considerably lower when compared to viral vectors. The work reported in this dissertation aims to fundamentally understand the underlying structure-transfect...

  7. Mechanochemically induced disordered structures of vincamine: the different mediation of two cross-linked polymers.

    Science.gov (United States)

    Hasa, Dritan; Perissutti, Beatrice; Chierotti, Michele Remo; Gobetto, Roberto; Grabnar, Iztok; Bonifacio, Alois; Dall'Acqua, Stefano; Invernizzi, Sergio; Voinovich, Dario

    2012-10-15

    The aims of this research were to prepare highly bioavailable binary cogrounds (vincamine-AcDiSol(®) or PVP-Cl) by means of a mechanochemical process and to study the mediation of each polymer in the induction of physical transformations of the drug. From a set of fifteen cogrounds for each crosslinked polymer, two samples were selected in each group on the basis of the AUC of in vitro dissolution profiles with the help of a statistical comparison. The chosen samples were analysed by means of TEM, XRPD, Raman-spectroscopy/imaging, SSNMR, also including the study of (1)H spin-lattice relaxation times. The research encompassed in vivo oral absorption studies in rats, pharmacokinetic analysis and physical stability studies during 1 year. An intimate drug-polymer mixing was found in the coground samples with domain average dimensions smaller than 100 Å; this reflected in a remarkable enhancement of the in vitro and in vivo bioavailability. Different disordered states were detected in the coground samples as a function of cogrinding time and the type and amount of polymer used. Though both crosslinked polymers produced a remarkable enhancement of the oral bioavailability, coground systems based on AcDiSol(®) are preferable in terms of pharmacokinetic performance and physical stability. PMID:22721852

  8. Sensitivity analysis for linear structural equation models, longitudinal mediation with latent growth models and blended learning in biostatistics education

    Science.gov (United States)

    Sullivan, Adam John

    In chapter 1, we consider the biases that may arise when an unmeasured confounder is omitted from a structural equation model (SEM) and sensitivity analysis techniques to correct for such biases. We give an analysis of which effects in an SEM are and are not biased by an unmeasured confounder. It is shown that a single unmeasured confounder will bias not just one but numerous effects in an SEM. We present sensitivity analysis techniques to correct for biases in total, direct, and indirect effects when using SEM analyses, and illustrate these techniques with a study of aging and cognitive function. In chapter 2, we consider longitudinal mediation with latent growth curves. We define the direct and indirect effects using counterfactuals and consider the assumptions needed for identifiability of those effects. We develop models with a binary treatment/exposure followed by a model where treatment/exposure changes with time allowing for treatment/exposure-mediator interaction. We thus formalize mediation analysis with latent growth curve models using counterfactuals, makes clear the assumptions and extends these methods to allow for exposure mediator interactions. We present and illustrate the techniques with a study on Multiple Sclerosis(MS) and depression. In chapter 3, we report on a pilot study in blended learning that took place during the Fall 2013 and Summer 2014 semesters here at Harvard. We blended the traditional BIO 200: Principles of Biostatistics and created ID 200: Principles of Biostatistics and epidemiology. We used materials from the edX course PH207x: Health in Numbers: Quantitative Methods in Clinical & Public Health Research and used. These materials were used as a video textbook in which students would watch a given number of these videos prior to class. Using surveys as well as exam data we informally assess these blended classes from the student's perspective as well as a comparison of these students with students in another course, BIO 201

  9. Enzyme-mediated self-assembly of highly ordered structures from disordered proteins

    International Nuclear Information System (INIS)

    Wheat gluten is an amorphous storage protein. Trypsin hydrolysis of wheat gluten produced glutamine-rich peptides. Some peptides were able to self-assemble into fibrous structures extrinsic to native wheat gluten. The final material was an in situ formed peptide composite of highly ordered nanometer-sized fibrils and micron-sized fibers embedded in an unassembled peptide matrix. Fourier transform infrared spectroscopic and x-ray diffraction data suggested that the new structures resembled that of cross- β fibrils found in some insect silk and implicated in prion diseases. The largest self-assembled fibers were about 10 µm in diameter with right-handed helicity and appeared to be bundles of smaller nanometer-sized fibrils. Results demonstrated the potential for utilizing natural mechanisms of protein self-assembly to design advanced materials that can provide a wide range of structural and chemical functionality

  10. Structures of Cas9 Endonucleases Reveal RNA-Mediated Conformational Activation

    OpenAIRE

    Jinek, Martin; Jiang, Fuguo; Taylor, David W.; Sternberg, Samuel H.; Kaya, Emine; MA, ENBO; Anders, Carolin; Hauer, Michael; Zhou, Kaihong; Lin, Steven; Kaplan, Matias; Anthony T Iavarone; Charpentier, Emmanuelle; Nogales, Eva; Doudna, Jennifer A.

    2014-01-01

    Type II CRISPR (clustered regularly interspaced short palindromic repeats)–Cas (CRISPR-associated) systems use an RNA-guided DNA endonuclease, Cas9, to generate double-strand breaks in invasive DNA during an adaptive bacterial immune response. Cas9 has been harnessed as a powerful tool for genome editing and gene regulation in many eukaryotic organisms. We report 2.6 and 2.2 angstrom resolution crystal structures of two major Cas9 enzyme subtypes, revealing the structural core shared by all C...

  11. P-glycoprotein-mediated resistance to chemotherapy in cancer cells: using recombinant cytosolic domains to establish structure-function relationships

    Directory of Open Access Journals (Sweden)

    Di Pietro A.

    1999-01-01

    Full Text Available Resistance to chemotherapy in cancer cells is mainly mediated by overexpression of P-glycoprotein (Pgp, a plasma membrane ATP-binding cassette (ABC transporter which extrudes cytotoxic drugs at the expense of ATP hydrolysis. Pgp consists of two homologous halves each containing a transmembrane domain and a cytosolic nucleotide-binding domain (NBD which contains two consensus Walker motifs, A and B, involved in ATP binding and hydrolysis. The protein also contains an S signature characteristic of ABC transporters. The molecular mechanism of Pgp-mediated drug transport is not known. Since the transporter has an extraordinarily broad substrate specificity, its cellular function has been described as a "hydrophobic vacuum cleaner". The limited knowledge about the mechanism of Pgp, partly due to the lack of a high-resolution structure, is well reflected in the failure to efficiently inhibit its activity in cancer cells and thus to reverse multidrug resistance (MDR. In contrast to the difficulties encountered when studying the full-length Pgp, the recombinant NBDs can be obtained in large amounts as soluble proteins. The biochemical and biophysical characterization of recombinant NBDs is shown here to provide a suitable alternative route to establish structure-function relationships. NBDs were shown to bind ATP and analogues as well as potent modulators of MDR, such as hydrophobic steroids, at a region close to the ATP site. Interestingly, flavonoids also bind to NBDs with high affinity. Their binding site partly overlaps both the ATP-binding site and the steroid-interacting region. Therefore flavonoids constitute a new promising class of bifunctional modulators of Pgp.

  12. An RNA secondary structure bias for non-homologous reverse transcriptase-mediated deletions in vivo

    DEFF Research Database (Denmark)

    Duch, Mogens; Carrasco, Maria L; Jespersen, Thomas;

    2004-01-01

    result from template switching during first-strand cDNA synthesis and that the choice of acceptor sites for non-homologous recombination are guided by non-paired regions. Our results may have implications for recombination events taking place within structured regions of retroviral RNA genomes......, especially in the absence of longer stretches of sequence similarity....

  13. Interactional and Structural Characteristics of Communication and Social Interactions during Computer-Mediated Communication

    Science.gov (United States)

    Gibbs, William J.; Bernas, Roman S.

    2008-01-01

    This study used precepts of social network theory to examine the interactional and structural characteristics of communication in peer-mentoring conferences. Twelve discussion conferences were set up to support students during a teaching practicum experience. The conferences were governed by students with minimal instructor involvement. It was…

  14. Structure and function of ABCG2-rich extracellular vesicles mediating multidrug resistance.

    Directory of Open Access Journals (Sweden)

    Vicky Goler-Baron

    Full Text Available Multidrug resistance (MDR is a major impediment to curative cancer chemotherapy. The ATP-Binding Cassette transporters ABCG2, ABCB1 and ABCC2 form a unique defense network against multiple structurally and functionally distinct chemotherapeutics, thereby resulting in MDR. Thus, deciphering novel mechanisms of MDR and their overcoming is a major goal of cancer research. Recently we have shown that overexpression of ABCG2 in the membrane of novel extracellular vesicles (EVs in breast cancer cells results in mitoxantrone resistance due to its dramatic sequestration in EVs. However, nothing is known about EVs structure, biogenesis and their ability to concentrate multiple antitumor agents. To this end, we here found that EVs are structural and functional homologues of bile canaliculi, are apically localized, sealed structures reinforced by an actin-based cytoskeleton and secluded from the extracellular milieu by the tight junction proteins occludin and ZO-1. Apart from ABCG2, ABCB1 and ABCC2 were also selectively targeted to the membrane of EVs. Moreover, Ezrin-Radixin-Moesin protein complex selectively localized to the border of the EVs membrane, suggesting a key role for the tethering of MDR pumps to the actin cytoskeleton. The ability of EVs to concentrate and sequester different antitumor drugs was also explored. Taking advantage of the endogenous fluorescence of anticancer drugs, we found that EVs-forming breast cancer cells display high level resistance to topotecan, imidazoacridinones and methotrexate via efficient intravesicular drug concentration hence sequestering them away from their cellular targets. Thus, we identified a new modality of anticancer drug compartmentalization and resistance in which multiple chemotherapeutics are actively pumped from the cytoplasm and highly concentrated within the lumen of EVs via a network of MDR transporters differentially targeted to the EVs membrane. We propose a composite model for the structure and

  15. Hierarchically structured one-dimensional TiO2 for protein immobilization, direct electrochemistry, and mediator-free glucose sensing.

    Science.gov (United States)

    Si, Peng; Ding, Shujiang; Yuan, Jun; Lou, Xiong Wen David; Kim, Dong-Hwan

    2011-09-27

    A novel one-dimensional hierarchically structured TiO(2) (1DHS TiO(2)) was synthesized by a solvothermal method using multiwalled carbon nanotubes (MWCNTs) as a template and evaluated for the immobilization of protein and biosensing applications. Characterization studies showed that the 1DHS TiO(2) possessed an anatase crystalline structure and a large surface area with narrow pore size distribution. Fast direct electron transfer was observed for glucose oxidase (GOx) immobilized on the 1DHS TiO(2), and excellent electrocatalytic performance for glucose detection can be obtained without a mediator. The glucose sensor based on the GOx/1DHS TiO(2)-modified electrode had a high sensitivity of 9.90 μA mM(-1) cm(-2) and a low detection limit of 1.29 μM. The fabricated biosensor displayed good selectivity and long-term stability, indicating that the novel structured TiO(2) is a promising material for the immobilization of biomolecules and the fabrication of third-generation biosensors. PMID:21866956

  16. Participation Structures as a Mediational Means: Learning Balinese Gamelan in the United States through Intent Participation, Mediated Discourse, and Distributed Cognition

    Science.gov (United States)

    Jocuns, Andrew

    2009-01-01

    Participation has presented a complex unit of analysis for interactional sociolinguistics. In this study I add another dimension to participation by considering recent theories related to sociocultural activity theory--mediated discourse analysis and distributed cognition. Drawing on examples from "maguru panggul", the traditional pedagogy of…

  17. A structurally plastic ribonucleoprotein complex mediates post-transcriptional gene regulation in HIV-1.

    Science.gov (United States)

    Fernandes, Jason D; Booth, David S; Frankel, Alan D

    2016-07-01

    HIV replication requires the nuclear export of essential, intron-containing viral RNAs. To facilitate export, HIV encodes the viral accessory protein Rev which binds unspliced and partially spliced viral RNAs and creates a ribonucleoprotein complex that recruits the cellular Chromosome maintenance factor 1 export machinery. Exporting RNAs in this manner bypasses the necessity for complete splicing as a prerequisite for mRNA export, and allows intron-containing RNAs to reach the cytoplasm intact for translation and virus packaging. Recent structural studies have revealed that this entire complex exhibits remarkable plasticity at many levels of organization, including RNA folding, protein-RNA recognition, multimer formation, and host factor recruitment. In this review, we explore each aspect of plasticity from structural, functional, and possible therapeutic viewpoints. WIREs RNA 2016, 7:470-486. doi: 10.1002/wrna.1342 For further resources related to this article, please visit the WIREs website. PMID:26929078

  18. Discerning direct and mediated effects of ecological structures and processes on adolescents' educational outcomes.

    Science.gov (United States)

    Benner, Aprile D; Graham, Sandra; Mistry, Rashmita S

    2008-05-01

    This short-term longitudinal study examined the relations among family and school characteristics, family-level processes (youth perceptions of parent-adolescent interactions), school-level processes (youth perceptions of school belonging, school climate), adolescents' school engagement, and later academic performance. Participants were an ethnically diverse, urban sample of 1,120 9th-grade students (M age = 14.6 years). The structural characteristics of families and schools influenced the proximal processes that occurred therein, and these proximal processes, in turn, influenced students' proximal (i.e., engagement) and distal educational outcomes (i.e., grades in school). Moreover, the structural characteristics of families and schools influenced proximal and distal outcomes indirectly through their influence on the proximal processes. The multimediated ecological model suggested that intervening at the process level may be a successful means of improving both adolescents' engagement in school and their subsequent school performance. PMID:18473648

  19. Ecological Networks over the Edge: Hypergraph Trait-Mediated Indirect Interaction (TMII) Structure.

    Science.gov (United States)

    Golubski, Antonio J; Westlund, Erik E; Vandermeer, John; Pascual, Mercedes

    2016-05-01

    Analyses of ecological network structure have yielded important insights into the functioning of complex ecological systems. However, such analyses almost universally omit non-pairwise interactions, many classes of which are crucial for system structure, function, and resilience. Hypergraphs are mathematical constructs capable of considering such interactions: we discuss their utility for studying ecological networks containing diverse interaction types, and associated challenges and strategies. We demonstrate the approach using a real-world coffee agroecosystem in which resistance to agricultural pests depends upon a large number of TMIIs. A hypergraph representation successfully reflects both the importance of species imposing such effects and the context-dependency of that importance in terms of how it is affected by removal of other species from the system. PMID:26924738

  20. A Cluster of Thin Tubular Structures Mediates Transformation of the Endoplasmic Reticulum to Autophagic Isolation Membrane

    OpenAIRE

    Uemura, Takefumi; Yamamoto, Masaya; Kametaka, Ai; Sou, Yu-shin; Yabashi, Atsuko; Yamada, Akane; Annoh, Hiromichi; Kametaka, Satoshi; Komatsu, Masaaki; Waguri, Satoshi

    2014-01-01

    Recent findings have suggested that the autophagic isolation membrane (IM) might originate from a domain of the endoplasmic reticulum (ER) called the omegasome. However, the morphological relationships between ER, omegasome, and IM remain unclear. In the present study, we found that hybrid structures composed of a double FYVE domain-containing protein 1 (DFCP1)-positive omegasome and the IM accumulated in Atg3-deficient mouse embryonic fibroblasts (MEFs). Moreover, correlative light and elect...

  1. Structural insights into viral determinants of nematode mediated grapevine fanleaf virus transmission

    OpenAIRE

    Schellenberger, Pascale; Sauter, Claude; Lorber, Bernard; Bron, Patrick; Trapani, Stefano; Bergdoll, Marc; Marmonier, Aurelie; Schmitt-Keichinger, Corinne; Lemaire, Olivier; Demangeat, Gerard; Ritzenthaler, Christophe

    2011-01-01

    Many animal and plant viruses rely on vectors for their transmission from host to host. Grapevine fanleaf virus (GFLV), a picorna-like virus from plants, is transmitted specifically by the ectoparasitic nematode Xiphinema index. The icosahedral capsid of GFLV, which consists of 60 identical coat protein subunits (CP), carries the determinants of this specificity. Here, we provide novel insight into GFLV transmission by nematodes through a comparative structural and functional analysis of two ...

  2. Precursor Mediated Synthesis of Nanostructured Silicas: From Precursor-Surfactant Ion Pairs to Structured Materials

    OpenAIRE

    Peter Hesemann; Thy Phung Nguyen; Samir El Hankari

    2014-01-01

    The synthesis of nanostructured anionic-surfactant-templated mesoporous silica (AMS) recently appeared as a new strategy for the formation of nanostructured silica based materials. This method is based on the use of anionic surfactants together with a co-structure-directing agent (CSDA), mostly a silylated ammonium precursor. The presence of this CSDA is necessary in order to create ionic interactions between template and silica forming phases and to ensure sufficient affinity between the tw...

  3. Structure of Ostertagia ostertagi ASP-1: insights into disulfide-mediated cyclization and dimerization.

    Science.gov (United States)

    Borloo, Jimmy; Geldhof, Peter; Peelaers, Iris; Van Meulder, Frederik; Ameloot, Paul; Callewaert, Nico; Vercruysse, Jozef; Claerebout, Edwin; Strelkov, Sergei V; Weeks, Stephen D

    2013-04-01

    The cysteine-rich secretory/antigen 5/pathogenesis-related 1 (CAP) protein superfamily is composed of a functionally diverse group of members that are found in both eukaryotes and prokaryotes. The excretome/secretome of numerous helminths (parasitic nematodes) contains abundant amounts of CAP members termed activation-associated secreted proteins (ASPs). Although ASPs are necessary for the parasitic life cycle in the host, the current lack of structural and functional information limits both understanding of their actual role in host-parasite interactions and the development of new routes in controlling parasitic infections and diseases. Alleviating this knowledge gap, a 1.85 Å resolution structure of recombinantly produced Oo-ASP-1 from Ostertagia ostertagi, which is one of the most prevalent gastrointestinal parasites in cattle worldwide, was solved. Overall, Oo-ASP-1 displays the common hallmark architecture shared by all CAP-superfamily members, including the N-terminal CAP and C-terminal cysteine-rich domains, but it also reveals a number of highly peculiar features. In agreement with studies of the natively produced protein, the crystal structure shows that Oo-ASP-1 forms a stable dimer that has been found to be primarily maintained via an intermolecular disulfide bridge, hence the small interaction surface of only 306.8 Å(2). Moreover, unlike any other ASP described to date, an additional intramolecular disulfide bridge links the N- and C-termini of each monomer, thereby yielding a quasi-cyclic molecule. Taken together, the insights presented here form an initial step towards a better understanding of the actual biological role(s) that this ASP plays in host-parasite interactions. The structure is also essential to help to define the key regions of the protein suitable for development of ASP-based vaccines, which would enable the current issues surrounding anthelmintic resistance in the treatment of parasitic infections and diseases to be circumvented

  4. Dopamine synapse is a neuroligin-2-mediated contact between dopaminergic presynaptic and GABAergic postsynaptic structures.

    Science.gov (United States)

    Uchigashima, Motokazu; Ohtsuka, Toshihisa; Kobayashi, Kazuto; Watanabe, Masahiko

    2016-04-12

    Midbrain dopamine neurons project densely to the striatum and form so-called dopamine synapses on medium spiny neurons (MSNs), principal neurons in the striatum. Because dopamine receptors are widely expressed away from dopamine synapses, it remains unclear how dopamine synapses are involved in dopaminergic transmission. Here we demonstrate that dopamine synapses are contacts formed between dopaminergic presynaptic and GABAergic postsynaptic structures. The presynaptic structure expressed tyrosine hydroxylase, vesicular monoamine transporter-2, and plasmalemmal dopamine transporter, which are essential for dopamine synthesis, vesicular filling, and recycling, but was below the detection threshold for molecules involving GABA synthesis and vesicular filling or for GABA itself. In contrast, the postsynaptic structure of dopamine synapses expressed GABAergic molecules, including postsynaptic adhesion molecule neuroligin-2, postsynaptic scaffolding molecule gephyrin, and GABAA receptor α1, without any specific clustering of dopamine receptors. Of these, neuroligin-2 promoted presynaptic differentiation in axons of midbrain dopamine neurons and striatal GABAergic neurons in culture. After neuroligin-2 knockdown in the striatum, a significant decrease of dopamine synapses coupled with a reciprocal increase of GABAergic synapses was observed on MSN dendrites. This finding suggests that neuroligin-2 controls striatal synapse formation by giving competitive advantage to heterologous dopamine synapses over conventional GABAergic synapses. Considering that MSN dendrites are preferential targets of dopamine synapses and express high levels of dopamine receptors, dopamine synapse formation may serve to increase the specificity and potency of dopaminergic modulation of striatal outputs by anchoring dopamine release sites to dopamine-sensing targets. PMID:27035941

  5. Evidence of ion intercalation mediated band structure modification and opto-ionic coupling in lithium niobite

    Energy Technology Data Exchange (ETDEWEB)

    Shank, Joshua C.; Tellekamp, M. Brooks; Doolittle, W. Alan, E-mail: alan.doolittle@ece.gatech.edu [Department of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

    2015-01-21

    The theoretically suggested band structure of the novel p-type semiconductor lithium niobite (LiNbO{sub 2}), the direct coupling of photons to ion motion, and optically induced band structure modifications are investigated by temperature dependent photoluminescence. LiNbO{sub 2} has previously been used as a memristor material but is shown here to be useful as a sensor owing to the electrical, optical, and chemical ease of lithium removal and insertion. Despite the high concentration of vacancies present in lithium niobite due to the intentional removal of lithium atoms, strong photoluminescence spectra are observed even at room temperature that experimentally confirm the suggested band structure implying transitions from a flat conduction band to a degenerate valence band. Removal of small amounts of lithium significantly modifies the photoluminescence spectra including additional larger than stoichiometric-band gap features. Sufficient removal of lithium results in the elimination of the photoluminescence response supporting the predicted transition from a direct to indirect band gap semiconductor. In addition, non-thermal coupling between the incident laser and lithium ions is observed and results in modulation of the electrical impedance.

  6. Interplay between desolvation and secondary structure in mediating cosolvent and temperature induced alpha-synuclein aggregation

    International Nuclear Information System (INIS)

    Both increased temperature and moderate concentrations of fluorinated alcohols enhance aggregation of the Parkinson's disease-associated protein α-synuclein (αS). Here, we investigate the secondary structural rearrangements induced by heating and trifluoroethanol [TFE]. At low TFE concentrations, CD spectra feature a negative peak characteristic of disordered polypeptides near 200 nm and a slight shoulder around 220 nm suggesting some polyproline-II content. Upon heating, these peaks weaken, while a weak negative signal develops at 222 nm. At high TFE concentrations, the spectra show distinct minima at 208 and 222 nm, indicative of considerable α-helical structure, which diminish upon heating. We observe a crossover between the low-TFE and high-TFE behavior near 15% TFE, where we previously showed that a partially helical intermediate is populated. We postulate that the protein is well solvated by water at low TFE concentrations and by TFE at high TFE concentrations, but may become desolvated at the crossover point. We discuss the potential roles and interplay of desolvation and helical secondary structure in driving αS aggregation. (paper)

  7. Structural insights into viral determinants of nematode mediated Grapevine fanleaf virus transmission.

    Science.gov (United States)

    Schellenberger, Pascale; Sauter, Claude; Lorber, Bernard; Bron, Patrick; Trapani, Stefano; Bergdoll, Marc; Marmonier, Aurélie; Schmitt-Keichinger, Corinne; Lemaire, Olivier; Demangeat, Gérard; Ritzenthaler, Christophe

    2011-05-01

    Many animal and plant viruses rely on vectors for their transmission from host to host. Grapevine fanleaf virus (GFLV), a picorna-like virus from plants, is transmitted specifically by the ectoparasitic nematode Xiphinema index. The icosahedral capsid of GFLV, which consists of 60 identical coat protein subunits (CP), carries the determinants of this specificity. Here, we provide novel insight into GFLV transmission by nematodes through a comparative structural and functional analysis of two GFLV variants. We isolated a mutant GFLV strain (GFLV-TD) poorly transmissible by nematodes, and showed that the transmission defect is due to a glycine to aspartate mutation at position 297 (Gly297Asp) in the CP. We next determined the crystal structures of the wild-type GFLV strain F13 at 3.0 Å and of GFLV-TD at 2.7 Å resolution. The Gly297Asp mutation mapped to an exposed loop at the outer surface of the capsid and did not affect the conformation of the assembled capsid, nor of individual CP molecules. The loop is part of a positively charged pocket that includes a previously identified determinant of transmission. We propose that this pocket is a ligand-binding site with essential function in GFLV transmission by X. index. Our data suggest that perturbation of the electrostatic landscape of this pocket affects the interaction of the virion with specific receptors of the nematode's feeding apparatus, and thereby severely diminishes its transmission efficiency. These data provide a first structural insight into the interactions between a plant virus and a nematode vector. PMID:21625570

  8. Structural insights into viral determinants of nematode mediated Grapevine fanleaf virus transmission.

    Directory of Open Access Journals (Sweden)

    Pascale Schellenberger

    2011-05-01

    Full Text Available Many animal and plant viruses rely on vectors for their transmission from host to host. Grapevine fanleaf virus (GFLV, a picorna-like virus from plants, is transmitted specifically by the ectoparasitic nematode Xiphinema index. The icosahedral capsid of GFLV, which consists of 60 identical coat protein subunits (CP, carries the determinants of this specificity. Here, we provide novel insight into GFLV transmission by nematodes through a comparative structural and functional analysis of two GFLV variants. We isolated a mutant GFLV strain (GFLV-TD poorly transmissible by nematodes, and showed that the transmission defect is due to a glycine to aspartate mutation at position 297 (Gly297Asp in the CP. We next determined the crystal structures of the wild-type GFLV strain F13 at 3.0 Å and of GFLV-TD at 2.7 Å resolution. The Gly297Asp mutation mapped to an exposed loop at the outer surface of the capsid and did not affect the conformation of the assembled capsid, nor of individual CP molecules. The loop is part of a positively charged pocket that includes a previously identified determinant of transmission. We propose that this pocket is a ligand-binding site with essential function in GFLV transmission by X. index. Our data suggest that perturbation of the electrostatic landscape of this pocket affects the interaction of the virion with specific receptors of the nematode's feeding apparatus, and thereby severely diminishes its transmission efficiency. These data provide a first structural insight into the interactions between a plant virus and a nematode vector.

  9. Decorin core protein (decoron shape complements collagen fibril surface structure and mediates its binding.

    Directory of Open Access Journals (Sweden)

    Joseph P R O Orgel

    Full Text Available Decorin is the archetypal small leucine rich repeat proteoglycan of the vertebrate extracellular matrix (ECM. With its glycosaminoglycuronan chain, it is responsible for stabilizing inter-fibrillar organization. Type I collagen is the predominant member of the fibrillar collagen family, fulfilling both organizational and structural roles in animal ECMs. In this study, interactions between decoron (the decorin core protein and binding sites in the d and e(1 bands of the type I collagen fibril were investigated through molecular modeling of their respective X-ray diffraction structures. Previously, it was proposed that a model-based, highly curved concave decoron interacts with a single collagen molecule, which would form extensive van der Waals contacts and give rise to strong non-specific binding. However, the large well-ordered aggregate that is the collagen fibril places significant restraints on modes of ligand binding and necessitates multi-collagen molecular contacts. We present here a relatively high-resolution model of the decoron-fibril collagen complex. We find that the respective crystal structures complement each other well, although it is the monomeric form of decoron that shows the most appropriate shape complementarity with the fibril surface and favorable calculated energies of interaction. One molecule of decoron interacts with four to six collagen molecules, and the binding specificity relies on a large number of hydrogen bonds and electrostatic interactions, primarily with the collagen motifs KXGDRGE and AKGDRGE (d and e(1 bands. This work helps us to understand collagen-decorin interactions and the molecular architecture of the fibrillar ECM in health and disease.

  10. Precursor Mediated Synthesis of Nanostructured Silicas: From Precursor-Surfactant Ion Pairs to Structured Materials

    Directory of Open Access Journals (Sweden)

    Peter Hesemann

    2014-04-01

    Full Text Available The synthesis of nanostructured anionic-surfactant-templated mesoporous silica (AMS recently appeared as a new strategy for the formation of nanostructured silica based materials. This method is based on the use of anionic surfactants together with a co-structure-directing agent (CSDA, mostly a silylated ammonium precursor. The presence of this CSDA is necessary in order to create ionic interactions between template and silica forming phases and to ensure sufficient affinity between the two phases. This synthetic strategy was for the first time applied in view of the synthesis of surface functionalized silica bearing ammonium groups and was then extended on the formation of materials functionalized with anionic carboxylate and bifunctional amine-carboxylate groups. In the field of silica hybrid materials, the “anionic templating” strategy has recently been applied for the synthesis of silica hybrid materials from cationic precursors. Starting from di- or oligosilylated imidazolium and ammonium precursors, only template directed hydrolysis-polycondensation reactions involving complementary anionic surfactants allowed accessing structured ionosilica hybrid materials. The mechanistic particularity of this approach resides in the formation of precursor-surfactant ion pairs in the hydrolysis-polycondensation mixture. This review gives a systematic overview over the various types of materials accessed from this cooperative ionic templating approach and highlights the high potential of this original strategy for the formation of nanostructured silica based materials which appears as a complementary strategy to conventional soft templating approaches.

  11. Soil development mediated by traditional practices shape the stand structure of Spanish juniper woodland

    Directory of Open Access Journals (Sweden)

    Javier de la Fuente-Leon

    2014-03-01

    Full Text Available Aim of study: Assessing the effect of soil development on the stand structure of a Spanish juniper forest traditionally shaped by livestock browsing and wood extraction. Area of study: Berlanga de Duero (Soria, Castilla y León, Spain.Material and Methods: A stand inventory served to record stand structure. Tree age, height, DBH, basal area, and overbark volume were determined in each plot. Results were pooled considering two well-differentiated degrees of soil evolution. One-way ANOVAs (and Tukey’s test and regressions between growth parameters were performed to assess significant differences between growth performances on both types of soils. Research highlights: Deeper soils yielded significant higher plant density and stand stock figures than stony shallower profiles despite the intense past livestock activity in the area; and single tree-size was also significantly greater. Non-significant differences were found for merchantable junipers age (≈120-160 years. Wood extraction and livestock browsing should be limited on shallower soils to allow soil and forest evolution; as well as to preserve the genetic pool better adapted to hardest growing conditions.Keywords: livestock browsing; forest development; Juniperus thurifera L.; soil evolution; stand stock.

  12. FOOD PROCESSING TECHNOLOGY AS A MEDIATOR OF FUNCTIONALITY. STRUCTURE-PROPERTY-PROCESS RELATIONSHIPS

    Directory of Open Access Journals (Sweden)

    Ester Betoret

    2015-02-01

    Full Text Available During the last years, the food industry has been facing technical and economic changes both in society and in the food processing practices, paying high attention to food products that meet the consumers´ demands. In this direction, the study areas in food process and products have evolved mainly from safety to other topics such as quality, environment or health. The improvement of the food products is now directed towards ensuring nutritional and specific functional benefits. Regarding the processes evolution, they are directed to ensure the quality and safety of environmentally friendly food products produced optimizing the use of resources, minimally affecting or even enhancing their nutritional and beneficial characteristics. The product structure both in its raw form and after processing plays an important role maintaining, enhancing and delivering the bioactive compounds in the appropriate target within the organism. The aim of this review is to make an overview on some synergistic technologies that can constitute a technological process to develop functional foods, enhancing the technological and/or nutritional functionality of the food products in which they are applied. More concretely, the effect of homogenization, vacuum impregnation and drying operations on bioactive compounds have been reviewed, focusing on the structure changes produced and its relationship on the product functionality, as well as on the parameters and the strategies used to quantify and increase the achieved functionality.

  13. Habitat structure mediates predation risk for sedentary prey: Experimental tests of alternative hypotheses

    Science.gov (United States)

    Chalfoun, A.D.; Martin, T.E.

    2009-01-01

    Predation is an important and ubiquitous selective force that can shape habitat preferences of prey species, but tests of alternative mechanistic hypotheses of habitat influences on predation risk are lacking. 2. We studied predation risk at nest sites of a passerine bird and tested two hypotheses based on theories of predator foraging behaviour. The total-foliage hypothesis predicts that predation will decline in areas of greater overall vegetation density by impeding cues for detection by predators. The potential-prey-site hypothesis predicts that predation decreases where predators must search more unoccupied potential nest sites. 3. Both observational data and results from a habitat manipulation provided clear support for the potential-prey-site hypothesis and rejection of the total-foliage hypothesis. Birds chose nest patches containing both greater total foliage and potential nest site density (which were correlated in their abundance) than at random sites, yet only potential nest site density significantly influenced nest predation risk. 4. Our results therefore provided a clear and rare example of adaptive nest site selection that would have been missed had structural complexity or total vegetation density been considered alone. 5. Our results also demonstrated that interactions between predator foraging success and habitat structure can be more complex than simple impedance or occlusion by vegetation. ?? 2008 British Ecological Society.

  14. Sunlight mediated seasonality in canopy structure and photosynthetic activity of Amazonian rainforests

    International Nuclear Information System (INIS)

    Resolving the debate surrounding the nature and controls of seasonal variation in the structure and metabolism of Amazonian rainforests is critical to understanding their response to climate change. In situ studies have observed higher photosynthetic and evapotranspiration rates, increased litterfall and leaf flushing during the Sunlight-rich dry season. Satellite data also indicated higher greenness level, a proven surrogate of photosynthetic carbon fixation, and leaf area during the dry season relative to the wet season. Some recent reports suggest that rainforests display no seasonal variations and the previous results were satellite measurement artefacts. Therefore, here we re-examine several years of data from three sensors on two satellites under a range of sun positions and satellite measurement geometries and document robust evidence for a seasonal cycle in structure and greenness of wet equatorial Amazonian rainforests. This seasonal cycle is concordant with independent observations of solar radiation. We attribute alternative conclusions to an incomplete study of the seasonal cycle, i.e. the dry season only, and to prognostications based on a biased radiative transfer model. Consequently, evidence of dry season greening in geometry corrected satellite data was ignored and the absence of evidence for seasonal variation in lidar data due to noisy and saturated signals was misinterpreted as evidence of the absence of changes during the dry season. Our results, grounded in the physics of radiative transfer, buttress previous reports of dry season increases in leaf flushing, litterfall, photosynthesis and evapotranspiration in well-hydrated Amazonian rainforests. (letter)

  15. Structured superparamagnetic nanoparticles for high performance mediator of magnetic fluid hyperthermia: synthesis, colloidal stability and biocompatibility evaluation.

    Science.gov (United States)

    Thorat, N D; Otari, S V; Bohara, R A; Yadav, H M; Khot, V M; Salunkhe, A B; Phadatare, M R; Prasad, A I; Ningthoujam, R S; Pawar, S H

    2014-09-01

    Core-shell structures with magnetic core and metal/polymer shell provide a new opportunity for constructing highly efficient mediator for magnetic fluid hyperthermia. Herein, a facile method is described for the synthesis of superparamagnetic LSMO@Pluronic F127 core-shell nanoparticles. Initially, the surface of the LSMO nanoparticles is functionalized with oleic acid and the polymeric shell formation is achieved through hydrophobic interactions with oleic acid. Each step is optimized to get good dispersion and less aggregation. This methodology results into core-shell formation, of average diameter less than 40 nm, which was stable under physiological conditions. After making a core-shell formulation, a significant increase of specific absorption rate (up to 300%) has been achieved with variation of the magnetization (Fe3O4. MTT assay is used to evaluate the toxicity of bare and core-shell MNPs. The mechanism of cell death by necrosis and apoptosis is studied with sequential staining of acridine orange and ethidium bromide using fluorescence and confocal microscopy. The present work reports a facile method for the synthesis of core-shell structure which significantly improves SAR and biocompatibility of bare LSMO MNPs, indicating potential application for hyperthermia. PMID:25063164

  16. Structural Insights into the Niemann-Pick C1 (NPC1)-Mediated Cholesterol Transfer and Ebola Infection.

    Science.gov (United States)

    Gong, Xin; Qian, Hongwu; Zhou, Xinhui; Wu, Jianping; Wan, Tao; Cao, Pingping; Huang, Weiyun; Zhao, Xin; Wang, Xudong; Wang, Peiyi; Shi, Yi; Gao, George F; Zhou, Qiang; Yan, Nieng

    2016-06-01

    Niemann-Pick disease type C (NPC) is associated with mutations in NPC1 and NPC2, whose gene products are key players in the endosomal/lysosomal egress of low-density lipoprotein-derived cholesterol. NPC1 is also the intracellular receptor for Ebola virus (EBOV). Here, we present a 4.4 Å structure of full-length human NPC1 and a low-resolution reconstruction of NPC1 in complex with the cleaved glycoprotein (GPcl) of EBOV, both determined by single-particle electron cryomicroscopy. NPC1 contains 13 transmembrane segments (TMs) and three distinct lumenal domains A (also designated NTD), C, and I. TMs 2-13 exhibit a typical resistance-nodulation-cell division fold, among which TMs 3-7 constitute the sterol-sensing domain conserved in several proteins involved in cholesterol metabolism and signaling. A trimeric EBOV-GPcl binds to one NPC1 monomer through the domain C. Our structural and biochemical characterizations provide an important framework for mechanistic understanding of NPC1-mediated intracellular cholesterol trafficking and Ebola virus infection. PMID:27238017

  17. Dopamine agonist suppression of rapid-eye-movement sleep is secondary to sleep suppression mediated via limbic structures

    International Nuclear Information System (INIS)

    The effects of pergolide, a direct dopamine receptor agonist, on sleep and wakefulness, motor behavior and 3H-spiperone specific binding in limbic structures and striatum in rats was studied. The results show that pergolide induced a biphasic dose effect, with high doses increasing wakefulness and suppressing sleep while low dose decreased wakefulness, but increased sleep. It was shown that pergolide-induced sleep suppression was blocked by α-glupenthixol and pimozide, two dopamine receptor antagonists. It was further shown that pergolide merely delayed the rebound resulting from rapid-eye-movement (REM) sleep deprivation, that dopamine receptors stimulation had no direct effect on the period, phase or amplitude of the circadian rhythm of REM sleep propensity and that there was no alteration in the coupling of REM sleep episodes with S2 episodes. Rapid-eye-movement sleep deprivation resulted in increased sensitivity to the pergolide-induced wakefulness stimulation and sleep suppression and pergolide-induced motor behaviors of locomotion and head bobbing. 3H-spiperone specific binding to dopamine receptors was shown to be altered by REM sleep deprivation in the subcortical limbic structures. It is concluded that the REM sleep suppressing action of dopamine receptor stimulation is secondary to sleep suppression per se and not secondary to a unique effect on the REM sleep. Further, it is suggested that the wakefulness stimulating action of dopamine receptor agonists is mediated by activation of the dopamine receptors in the terminal areas of the mesolimbocortical dopamine projection system

  18. Structure-Based Identification of a Potent Inhibitor Targeting Stp1-Mediated Virulence Regulation in Staphylococcus aureus.

    Science.gov (United States)

    Zheng, Weihao; Cai, Xiaodan; Xie, Mingsheng; Liang, Yujie; Wang, Tao; Li, Zigang

    2016-08-18

    The increasing threats of antibiotic resistance urge the need for developing new strategies against bacterial infections. Targeting eukaryotic-like Ser/Thr phosphatase Stp1-mediated virulence regulation represents a promising approach for combating staphylococcal infection yet to be explored. Here, we report the 2.32-Å resolution crystal structure of Stp1. Stp1 binds an unexpected fourth metal ion, which is important for Stp1's enzymatic activity as demonstrated by amino acid substitution studies. Inspired by the structural details of Stp1, we identified a potent and selective Stp1 inhibitor, aurintricarboxylic acid (ATA). Transcriptome analysis and biochemical studies supported Stp1 as the target of ATA inhibition within the pathogen, preventing upregulation of virulence genes. Notably, ATA did not affect in vitro growth of Staphylococcus aureus, while simultaneously attenuating staphylococcal virulence in mice. Our findings demonstrate that ATA is a potent anti-virulence compound against staphylococcal infection, laying the foundation for further developing new scaffolds for Stp1-targeted small molecules. PMID:27499528

  19. Structural basis for Marburg virus VP35-mediated immune evasion mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Ramanan, Parameshwaran; Edwards, Megan R.; Shabman, Reed S.; Leung, Daisy W.; Endlich-Frazier, Ariel C.; Borek, Dominika M.; Otwinowski, Zbyszek; Liu, Gai; Huh, Juyoung; Basler, Christopher F.; Amarasinghe, Gaya K. [Sinai; (WU-MED); (UTSMC)

    2013-07-22

    Filoviruses, marburgvirus (MARV) and ebolavirus (EBOV), are causative agents of highly lethal hemorrhagic fever in humans. MARV and EBOV share a common genome organization but show important differences in replication complex formation, cell entry, host tropism, transcriptional regulation, and immune evasion. Multifunctional filoviral viral protein (VP) 35 proteins inhibit innate immune responses. Recent studies suggest double-stranded (ds)RNA sequestration is a potential mechanism that allows EBOV VP35 to antagonize retinoic-acid inducible gene-I (RIG-I) like receptors (RLRs) that are activated by viral pathogen–associated molecular patterns (PAMPs), such as double-strandedness and dsRNA blunt ends. Here, we show that MARV VP35 can inhibit IFN production at multiple steps in the signaling pathways downstream of RLRs. The crystal structure of MARV VP35 IID in complex with 18-bp dsRNA reveals that despite the similar protein fold as EBOV VP35 IID, MARV VP35 IID interacts with the dsRNA backbone and not with blunt ends. Functional studies show that MARV VP35 can inhibit dsRNA-dependent RLR activation and interferon (IFN) regulatory factor 3 (IRF3) phosphorylation by IFN kinases TRAF family member-associated NFkb activator (TANK) binding kinase-1 (TBK-1) and IFN kB kinase e (IKKe) in cell-based studies. We also show that MARV VP35 can only inhibit RIG-I and melanoma differentiation associated gene 5 (MDA5) activation by double strandedness of RNA PAMPs (coating backbone) but is unable to inhibit activation of RLRs by dsRNA blunt ends (end capping). In contrast, EBOV VP35 can inhibit activation by both PAMPs. Insights on differential PAMP recognition and inhibition of IFN induction by a similar filoviral VP35 fold, as shown here, reveal the structural and functional plasticity of a highly conserved virulence factor.

  20. Successive invasion-mediated interspecific hybridizations and population structure in the endangered cichlid Oreochromis mossambicus.

    Directory of Open Access Journals (Sweden)

    Cyril Firmat

    Full Text Available Hybridization between invasive and native species accounts among the major and pernicious threats to biodiversity. The Mozambique tilapia Oreochromis mossambicus, a widely used freshwater aquaculture species, is especially imperiled by this phenomenon since it is recognized by the IUCN as an endangered taxon due to genetic admixture with O. niloticus an invasive congeneric species. The Lower Limpopo and the intermittent Changane River (Mozambique drain large wetlands of potentially great importance for conservation of O. mossambicus, but their populations have remained unstudied until today. Therefore we aimed (1 to estimate the autochthonous diversity and population structure among genetically pure O. mossambicus populations to provide a baseline for the conservation genetics of this endangered species, (2 to quantify and describe genetic variation of the invasive populations and investigate the most likely factors influencing their spread, (3 to identify O. mossambicus populations unaffected by hybridization. Bayesian assignment tests based on 423 AFLP loci and the distribution of 36 species-specific mitochondrial haplotypes both indicate a low frequency of invasive and hybrid genotypes throughout the system, but nevertheless reveal evidence for limited expansion of two alien species (O. niloticus and O. andersonii and their hybrids in the Lower Limpopo. O. mossambicus populations with no traces of hybridization are identified. They exhibit a significant genetic structure. This contrasts with previously published estimates and provides rather promising auspices for the conservation of O. mossambicus. Especially, parts of the Upper Changane drainage and surrounding wetlands are identified as refugial zones for O. mossambicus populations. They should therefore receive high conservation priority and could represent valuable candidates for the development of aquaculture strains based on local genetic resources.

  1. Unravelling the Influence of Cognitive Style on Chinese Students' Classroom Behaviours: The Mediating Effects of the Structure-Oriented/Depth-Oriented Learning Approach

    Science.gov (United States)

    Cheng, Hong-Yu; Guan, Shu-Yi

    2015-01-01

    This study was designed to investigate how cognitive style affects Chinese students' learning behaviours in the classroom. A concept labelled as the structure-oriented vs. depth-oriented learning approach was constructed, and its mediating effects in the link between cognitive style and learning behaviour were proposed and examined in this study.…

  2. Sequences of a hairpin structure in the 3'-untranslated region mediate regulation of human pulmonary surfactant protein B mRNA stability.

    Science.gov (United States)

    Huang, Helen W; Payne, David E; Bi, Weizhen; Pan, Su; Bruce, Shirley R; Alcorn, Joseph L

    2012-05-15

    The ability of pulmonary surfactant to reduce alveolar surface tension requires adequate expression of surfactant protein B (SP-B). Dexamethasone (DEX, 10(-7) M) increases human SP-B mRNA stability by a mechanism that requires a 126-nt-long segment (the 7.6S region) of the 3'-untranslated region (3'-UTR). The objective of this study was to identify sequences in the 7.6S region that mediate regulation of SP-B mRNA stability. The 7.6S region was found to be sufficient for DEX-mediated stabilization of mRNA. Sequential substitution mutagenesis of the 7.6S region indicates that a 90-nt region is required for DEX-mediated stabilization and maintenance of intrinsic stability. In this region, one 30-nt-long element (002), predicted to form a stem-loop structure, is sufficient for DEX-mediated stabilization of mRNA and intrinsic mRNA stability. Cytosolic proteins specifically bind element 002, and binding activity is unaffected whether proteins are isolated from cells incubated in the absence or presence of DEX. While loop sequences of element 002 have no role in regulation of SP-B mRNA stability, the proximal stem sequences are required for DEX-mediated stabilization and specific binding of proteins. Mutation of the sequences that comprise the proximal or distal arm of the stem negates the destabilizing activity of element 002 on intrinsic SP-B mRNA stability. These results indicate that cytosolic proteins bind a single hairpin structure that mediates intrinsic and hormonal regulation of SP-B mRNA stability via mechanisms that involve sequences of the stems of the hairpin structure. PMID:22367784

  3. The role of burnout syndrome as a mediator for the effect of psychosocial risk factors on the intensity of musculoskeletal disorders: a structural equation modeling approach.

    Science.gov (United States)

    Gholami, Tahereh; Pahlavian, Ahmad Heidari; Akbarzadeh, Mahdi; Motamedzade, Majid; Moghaddam, Rashid Heidari

    2016-01-01

    This study examined the hypothesis that burnout syndrome mediates effects of psychosocial risk factors and intensity of musculoskeletal disorders (MSDs) among hospital nurses. The sample was composed of 415 nurses from various wards across five hospitals of Iran's Hamedan University of Medical Sciences. Data were collected through three questionnaires: job content questionnaire, Maslach burnout inventory and visual analogue scale. Results of structural equation modeling with a mediating effect showed that psychosocial risk factors were significantly related to changes in burnout, which in turn affects intensity of MSDs. PMID:27075269

  4. The Effects of Supervisors' Support and Mediating Factors on the Nurses' Job Performance Using Structural Equation Modeling: A Case Study.

    Science.gov (United States)

    Ravangard, Ramin; Yasami, Shamim; Shokrpour, Nasrin; Sajjadnia, Zahra; Farhadi, Payam

    2015-01-01

    Nurses are the largest group and an important part of the providers in the health care systems that who a key role in hospitals. Any defect and deficiency in their work can result in irreversible outcomes. This study aimed to determine the effect of supervisors' support and mediating factors on the job performance (JOBPER) of 400 nurses working in the teaching hospitals affiliated to Shiraz University of Medical Sciences, using structural equation modeling. The results showed that the supervisor's support had a significant negative effect on work-family conflict (t = -2.57) and a positive effect on organizational commitment (t = 4.03); Work-family conflict had a significant positive effect on job stress (t = 11.24) and a negative effect on organizational commitment (t = -3.35) and JOBPER (t = -2.29). Family-work conflict had a positive effect on job stress (t = 4.48) and a negative effect on organizational commitment (t = -2.54). Finally, job stress had a negative effect (t = -3.30), and organizational commitment showed a positive effect (t = 5.96) on the studied nurses' JOBPER. According to the results, supervisor's support could influence JOBPER through reducing work-family conflict and increasing organizational commitment. Therefore, to improve the nurses' JOBPER in the hospitals, some strategies are recommended. PMID:26218002

  5. A structural domain mediates attachment of ethanolamine phosphoglycerol to eukaryotic elongation factor 1A in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Eva Greganova

    Full Text Available Ethanolamine phosphoglycerol (EPG represents a protein modification that so far has only been found in eukaryotic elongation factor 1A (eEF1A. In mammals and plants, EPG is covalently attached to two conserved glutamate residues located in domains II and III of eEF1A. In contrast, Trypanosoma brucei eEF1A contains a single EPG attached to Glu362 in domain III. The sequence and/or structural requirements for covalent linkage of EPG to eEF1A have not been determined for any organism. Using a combination of biosynthetic labelling of parasites with tritiated ethanolamine and mass spectrometry analyses, we demonstrate that replacement of Glu362 in T. brucei eEF1A by site-directed mutagenesis prevents EPG attachment, whereas single or multiple amino acid substitutions around the attachment site are not critical. In addition, by expressing a series of eEF1A deletion mutants in T. brucei procyclic forms, we demonstrate that a peptide consisting of 80 amino acids of domain III of eEF1A is sufficient for EPG attachment to occur. Furthermore, EPG addition also occurs if domain III of eEF1A is fused to a soluble reporter protein. To our knowledge, this is the first report addressing amino acid sequence, or structure, requirements for EPG modification of eEF1A in any organism. Using T. brucei as a model organism, we show that amino acid substitutions around the modification site are not critical for EPG attachment and that a truncated version of domain III of eEF1A is sufficient to mediate EPG addition.

  6. A Structural Analysis of Executive Functions and Socioeconomic Status in School-Age Children: Cognitive Factors as Effect Mediators

    Science.gov (United States)

    Aran-Filippetti, Vanessa; Richaud de Minzi, Maria Cristina

    2012-01-01

    Socioeconomic status (SES) is a well-known predictor of cognitive achievement and executive functioning, although the underlying cognitive mediating processes remain unclear. The authors analyze the association between different socioeconomic indicators and the executive functions (EF) of schoolchildren and the possible cognitive mediating factors…

  7. An analytical tool-box for comprehensive biochemical, structural and transcriptome evaluation of oral biofilms mediated by mutans streptococci.

    Science.gov (United States)

    Klein, Marlise I; Xiao, Jin; Heydorn, Arne; Koo, Hyun

    2011-01-01

    Biofilms are highly dynamic, organized and structured communities of microbial cells enmeshed in an extracellular matrix of variable density and composition (1, 2). In general, biofilms develop from initial microbial attachment on a surface followed by formation of cell clusters (or microcolonies) and further development and stabilization of the microcolonies, which occur in a complex extracellular matrix. The majority of biofilm matrices harbor exopolysaccharides (EPS), and dental biofilms are no exception; especially those associated with caries disease, which are mostly mediated by mutans streptococci (3). The EPS are synthesized by microorganisms (S. mutans, a key contributor) by means of extracellular enzymes, such as glucosyltransferases using sucrose primarily as substrate (3). Studies of biofilms formed on tooth surfaces are particularly challenging owing to their constant exposure to environmental challenges associated with complex diet-host-microbial interactions occurring in the oral cavity. Better understanding of the dynamic changes of the structural organization and composition of the matrix, physiology and transcriptome/proteome profile of biofilm-cells in response to these complex interactions would further advance the current knowledge of how oral biofilms modulate pathogenicity. Therefore, we have developed an analytical tool-box to facilitate biofilm analysis at structural, biochemical and molecular levels by combining commonly available and novel techniques with custom-made software for data analysis. Standard analytical (colorimetric assays, RT-qPCR and microarrays) and novel fluorescence techniques (for simultaneous labeling of bacteria and EPS) were integrated with specific software for data analysis to address the complex nature of oral biofilm research. The tool-box is comprised of 4 distinct but interconnected steps (Figure 1): 1) Bioassays, 2) Raw Data Input, 3) Data Processing, and 4) Data Analysis. We used our in vitro biofilm model and

  8. Identification of putative estrogen receptor-mediated endocrine disrupting chemicals using QSAR- and structure-based virtual screening approaches

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Liying; Sedykh, Alexander; Tripathi, Ashutosh [Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC (United States); Zhu, Hao [The Rutgers Center for Computational and Integrative Biology, Rutgers University, Camden, NJ (United States); Department of Chemistry, Rutgers University, Camden, NJ (United States); Afantitis, Antreas; Mouchlis, Varnavas D.; Melagraki, Georgia [NovaMechanics Ltd., Nicosia (Cyprus); Rusyn, Ivan, E-mail: iir@unc.edu [Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC (United States); Tropsha, Alexander, E-mail: alex_tropsha@unc.edu [Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC (United States)

    2013-10-01

    Identification of endocrine disrupting chemicals is one of the important goals of environmental chemical hazard screening. We report on the development of validated in silico predictors of chemicals likely to cause estrogen receptor (ER)-mediated endocrine disruption to facilitate their prioritization for future screening. A database of relative binding affinity of a large number of ERα and/or ERβ ligands was assembled (546 for ERα and 137 for ERβ). Both single-task learning (STL) and multi-task learning (MTL) continuous quantitative structure–activity relationship (QSAR) models were developed for predicting ligand binding affinity to ERα or ERβ. High predictive accuracy was achieved for ERα binding affinity (MTL R{sup 2} = 0.71, STL R{sup 2} = 0.73). For ERβ binding affinity, MTL models were significantly more predictive (R{sup 2} = 0.53, p < 0.05) than STL models. In addition, docking studies were performed on a set of ER agonists/antagonists (67 agonists and 39 antagonists for ERα, 48 agonists and 32 antagonists for ERβ, supplemented by putative decoys/non-binders) using the following ER structures (in complexes with respective ligands) retrieved from the Protein Data Bank: ERα agonist (PDB ID: 1L2I), ERα antagonist (PDB ID: 3DT3), ERβ agonist (PDB ID: 2NV7), and ERβ antagonist (PDB ID: 1L2J). We found that all four ER conformations discriminated their corresponding ligands from presumed non-binders. Finally, both QSAR models and ER structures were employed in parallel to virtually screen several large libraries of environmental chemicals to derive a ligand- and structure-based prioritized list of putative estrogenic compounds to be used for in vitro and in vivo experimental validation. - Highlights: • This is the largest curated dataset inclusive of ERα and β (the latter is unique). • New methodology that for the first time affords acceptable ERβ models. • A combination of QSAR and docking enables prediction of affinity and function.

  9. Identification of putative estrogen receptor-mediated endocrine disrupting chemicals using QSAR- and structure-based virtual screening approaches

    International Nuclear Information System (INIS)

    Identification of endocrine disrupting chemicals is one of the important goals of environmental chemical hazard screening. We report on the development of validated in silico predictors of chemicals likely to cause estrogen receptor (ER)-mediated endocrine disruption to facilitate their prioritization for future screening. A database of relative binding affinity of a large number of ERα and/or ERβ ligands was assembled (546 for ERα and 137 for ERβ). Both single-task learning (STL) and multi-task learning (MTL) continuous quantitative structure–activity relationship (QSAR) models were developed for predicting ligand binding affinity to ERα or ERβ. High predictive accuracy was achieved for ERα binding affinity (MTL R2 = 0.71, STL R2 = 0.73). For ERβ binding affinity, MTL models were significantly more predictive (R2 = 0.53, p < 0.05) than STL models. In addition, docking studies were performed on a set of ER agonists/antagonists (67 agonists and 39 antagonists for ERα, 48 agonists and 32 antagonists for ERβ, supplemented by putative decoys/non-binders) using the following ER structures (in complexes with respective ligands) retrieved from the Protein Data Bank: ERα agonist (PDB ID: 1L2I), ERα antagonist (PDB ID: 3DT3), ERβ agonist (PDB ID: 2NV7), and ERβ antagonist (PDB ID: 1L2J). We found that all four ER conformations discriminated their corresponding ligands from presumed non-binders. Finally, both QSAR models and ER structures were employed in parallel to virtually screen several large libraries of environmental chemicals to derive a ligand- and structure-based prioritized list of putative estrogenic compounds to be used for in vitro and in vivo experimental validation. - Highlights: • This is the largest curated dataset inclusive of ERα and β (the latter is unique). • New methodology that for the first time affords acceptable ERβ models. • A combination of QSAR and docking enables prediction of affinity and function. • The results have

  10. Mediation Analysis

    OpenAIRE

    David P. MacKinnon; Fairchild, Amanda J.; Fritz, Matthew S.

    2007-01-01

    Mediating variables are prominent in psychological theory and research. A mediating variable transmits the effect of an independent variable on a dependent variable. Differences between mediating variables and confounders, moderators, and covariates are outlined. Statistical methods to assess mediation and modern comprehensive approaches are described. Future directions for mediation analysis are discussed.

  11. Causal mediation analysis with a latent mediator.

    Science.gov (United States)

    Albert, Jeffrey M; Geng, Cuiyu; Nelson, Suchitra

    2016-05-01

    Health researchers are often interested in assessing the direct effect of a treatment or exposure on an outcome variable, as well as its indirect (or mediation) effect through an intermediate variable (or mediator). For an outcome following a nonlinear model, the mediation formula may be used to estimate causally interpretable mediation effects. This method, like others, assumes that the mediator is observed. However, as is common in structural equations modeling, we may wish to consider a latent (unobserved) mediator. We follow a potential outcomes framework and assume a generalized structural equations model (GSEM). We provide maximum-likelihood estimation of GSEM parameters using an approximate Monte Carlo EM algorithm, coupled with a mediation formula approach to estimate natural direct and indirect effects. The method relies on an untestable sequential ignorability assumption; we assess robustness to this assumption by adapting a recently proposed method for sensitivity analysis. Simulation studies show good properties of the proposed estimators in plausible scenarios. Our method is applied to a study of the effect of mother education on occurrence of adolescent dental caries, in which we examine possible mediation through latent oral health behavior. PMID:26363769

  12. Crystal Structure of A. aeolicus Argonaute, a Site-Specific DNA-Guided Endoribonuclease, Provides Insights into RISC-Mediated mRNA Cleavage

    OpenAIRE

    Yuan, Yu-Ren; Pei, Yi; Ma, Jin-Biao; Kuryavyi, Vitaly; Zhadina, Maria; Meister, Gunter; Chen, Hong-Ying; Dauter, Zbigniew; Tuschl, Thomas; Patel, Dinshaw J.

    2005-01-01

    Argonaute (Ago) proteins constitute a key component of the RNA-induced silencing complex (RISC). We report the crystal structure of Aquifex aeolicus Ago (Aa-Ago) together with binding and cleavage studies, which establish this eubacterial Ago as a bona fide guide DNA strand-mediated site-specific RNA endonuclease. We have generated a stereochemically robust model of the complex, where the guide DNA-mRNA duplex is positioned within a basic channel spanning the bilobal interface, such that the ...

  13. The Schizosaccharomyces pombe Mediator

    DEFF Research Database (Denmark)

    Venturi, Michela

    In the past several years great attention has been dedicated to the characterization of the Mediator complex in a different range of model organisms. Mediator is a conserved co-activator complex involved in transcriptional regulation and it conveys signals from regulatory transcription factors to...... the basal transcription machinery. Mediator was initially isolated from Saccharomyces cerevisiae based on its ability to render a RNA polymerase II in vitro transcription system responsive to activators. Additionally, structural studies have revealed striking structural similarities between S....... cerevisiae, Schizosaccharomyces pombe and mammalian Mediator. In our study, we have taken the S. pombe Mediator into consideration and characterized genetically and biochemically two subunits already know in S. cerevisiae, Med9 and Med11, but still not identified in the S. pombe Mediator. Genetic analysis...

  14. Biogenesis of non-structural protein 1 (nsp1) and nsp1-mediated type I interferon modulation in arteriviruses

    International Nuclear Information System (INIS)

    Type I interferons (IFNs-α/β) play a key role for the antiviral state of host, and the porcine arterivirus; porcine reproductive and respiratory syndrome virus (PRRSV), has been shown to down-regulate the production of IFNs during infection. Non-structural protein (nsp) 1 of PRRSV has been identified as a viral IFN antagonist, and the nsp1α subunit of nsp1 has been shown to degrade the CREB-binding protein (CBP) and to inhibit the formation of enhanceosome thus resulting in the suppression of IFN production. The study was expanded to other member viruses in the family Arteriviridae: equine arteritis virus (EAV), murine lactate dehydrogenase-elevating virus (LDV), and simian hemorrhagic fever virus (SHFV). While PRRSV–nsp1 and LDV–nsp1 were auto-cleaved to produce the nsp1α and nsp1β subunits, EAV–nsp1 remained uncleaved. SHFV–nsp1 was initially predicted to be cleaved to generate three subunits (nsp1α, nsp1β, and nsp1γ), but only two subunits were generated as SHFV–nsp1αβ and SHFV–nsp1γ. The papain-like cysteine protease (PLP) 1α motif in nsp1α remained inactive for SHFV, and only the PLP1β motif of nsp1β was functional to generate SHFV–nsp1γ subunit. All subunits of arterivirus nsp1 were localized in the both nucleus and cytoplasm, but PRRSV–nsp1β, LDV–nsp1β, EAV–nsp1, and SHFV–nsp1γ were predominantly found in the nucleus. All subunits of arterivirus nsp1 contained the IFN suppressive activity and inhibited both interferon regulatory factor 3 (IRF3) and NF-κB mediated IFN promoter activities. Similar to PRRSV–nsp1α, CBP degradation was evident in cells expressing LDV–nsp1α and SHFV–nsp1γ, but no such degradation was observed for EAV–nsp1. Regardless of CBP degradation, all subunits of arterivirus nsp1 suppressed the IFN-sensitive response element (ISRE)-promoter activities. Our data show that the nsp1-mediated IFN modulation is a common strategy for all arteriviruses but their mechanism of action may differ

  15. Biogenesis of non-structural protein 1 (nsp1) and nsp1-mediated type I interferon modulation in arteriviruses

    Energy Technology Data Exchange (ETDEWEB)

    Han, Mingyuan; Kim, Chi Yong [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, IL 61802 (United States); Rowland, Raymond R.R.; Fang, Ying [Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, KS 66506 (United States); Kim, Daewoo [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, IL 61802 (United States); Yoo, Dongwan, E-mail: dyoo@illinois.edu [Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, IL 61802 (United States)

    2014-06-15

    Type I interferons (IFNs-α/β) play a key role for the antiviral state of host, and the porcine arterivirus; porcine reproductive and respiratory syndrome virus (PRRSV), has been shown to down-regulate the production of IFNs during infection. Non-structural protein (nsp) 1 of PRRSV has been identified as a viral IFN antagonist, and the nsp1α subunit of nsp1 has been shown to degrade the CREB-binding protein (CBP) and to inhibit the formation of enhanceosome thus resulting in the suppression of IFN production. The study was expanded to other member viruses in the family Arteriviridae: equine arteritis virus (EAV), murine lactate dehydrogenase-elevating virus (LDV), and simian hemorrhagic fever virus (SHFV). While PRRSV–nsp1 and LDV–nsp1 were auto-cleaved to produce the nsp1α and nsp1β subunits, EAV–nsp1 remained uncleaved. SHFV–nsp1 was initially predicted to be cleaved to generate three subunits (nsp1α, nsp1β, and nsp1γ), but only two subunits were generated as SHFV–nsp1αβ and SHFV–nsp1γ. The papain-like cysteine protease (PLP) 1α motif in nsp1α remained inactive for SHFV, and only the PLP1β motif of nsp1β was functional to generate SHFV–nsp1γ subunit. All subunits of arterivirus nsp1 were localized in the both nucleus and cytoplasm, but PRRSV–nsp1β, LDV–nsp1β, EAV–nsp1, and SHFV–nsp1γ were predominantly found in the nucleus. All subunits of arterivirus nsp1 contained the IFN suppressive activity and inhibited both interferon regulatory factor 3 (IRF3) and NF-κB mediated IFN promoter activities. Similar to PRRSV–nsp1α, CBP degradation was evident in cells expressing LDV–nsp1α and SHFV–nsp1γ, but no such degradation was observed for EAV–nsp1. Regardless of CBP degradation, all subunits of arterivirus nsp1 suppressed the IFN-sensitive response element (ISRE)-promoter activities. Our data show that the nsp1-mediated IFN modulation is a common strategy for all arteriviruses but their mechanism of action may differ

  16. Secondary BRCA1 mutations in BRCA1-mutated ovarian carcinomas with platinum resistance

    OpenAIRE

    Swisher, Elizabeth M.; Sakai, Wataru; Karlan, Beth Y.; Wurz, Kaitlyn; Urban, Nicole; Taniguchi, Toshiyasu

    2008-01-01

    Although ovarian carcinomas with mutated BRCA1 or BRCA2 are sensitive to platinum compounds, such carcinomas eventually develop platinum resistance. Previously, we showed that acquired resistance to cisplatin in BRCA2-mutated tumors can be mediated by secondary intragenic mutations in BRCA2 that restore the wild-type BRCA2 reading frame. Here, we show that secondary mutations of BRCA1 also occur in BRCA1-mutated ovarian cancer with platinum resistance. We evaluated 9 recurrent BRCA1-mutated o...

  17. Population testing for cancer predisposing BRCA1/BRCA2 mutations

    OpenAIRE

    Wardle, J

    2014-01-01

    Background: Technological advances raise the possibility of systematic population-based genetic testing for cancer-predisposing mutations, but it is uncertain whether benefits outweigh disadvantages. We directly compared the psychological/quality-of-life consequences of such an approach to family history (FH)–based testing. Methods: In a randomized controlled trial of BRCA1/2 gene-mutation testing in the Ashkenazi Jewish (AJ) population, we compared testing all participants in the...

  18. BRCA1 and BRCA2: Cancer Risk and Genetic Testing

    Science.gov (United States)

    ... BP. Fanconi anemia and the development of leukemia. Best practice & research. Clinical Haematology 2014; 27(3-4):214- ... 2007; 39(2):165–167. [PubMed Abstract] Related Resources Cancer Genetics Risk ... and Human Services National Institutes of Health National Cancer Institute ...

  19. BRCA1- and BRCA2-Associated Ovarian Cancer: different diseases?

    NARCIS (Netherlands)

    P.M.L.H. Vencken (Peggy)

    2014-01-01

    markdownabstract__Abstract__ Ovarian cancer will develop in approximately 1.4% of the Dutch women accounting for approximately 1250 new patients yearly in the Netherlands, which is comparable with the incidence in other Western world countries. The disease mainly develops in women of 40 years of ag

  20. "Choice" and destiny: the substrate composition and mechanical stability of settlement structures can mediate coral recruit fate in post-bleached reefs

    Science.gov (United States)

    Yadav, Shreya; Rathod, Pooja; Alcoverro, Teresa; Arthur, Rohan

    2016-03-01

    Increasingly frequent and intense ocean warming events seriously test the buffer and recovery capacities of tropical coral reefs. Post-disturbance, available settlement structures on a reef (often dead coral skeletons) vary considerably in their mechanical stability and substrate composition, critically influencing coral recruit settlement choice and fate. In the wake of a coral mass mortality in the Lakshadweep archipelago, we examine (1) the relative availability of recruit settlement structures (from stable to unstable: reef platform, dead massive coral, consolidated rubble, dead corymbose coral, dead tabular coral, and unconsolidated rubble) in 12 recovering reefs across three atolls in the archipelago, (2) the substrate composition [crustose coralline algae (CCA), mixed turf, macroalgae] of these structural forms, and (3) whether the choice and fate of young coral are mediated by the substrate and stability of different structural forms. For this, we measured the abundance and distribution of recruit (recovery potential, aiding in assessments of reef resilience.

  1. Structure-function analysis of Leishmania lipophosphoglycan. Distinct domains that mediate binding and inhibition of endothelial cell function.

    Science.gov (United States)

    Ho, J L; Kim, H K; Sass, P M; He, S; Geng, J; Xu, H; Zhu, B; Turco, S J; Lo, S K

    1996-10-01

    We have shown that Leishmania lipophosphoglycan (LPG) inhibits IL-1 beta gene expression in human monocytes. Here, we show that LPG can bind in a time-dependent manner and suppress endothelial cell activation, possibly via specific LPG domains. Endotoxin (10 ng/ml, 4 h) consistently caused endothelium to increase monocyte adhesion (approximately 20-fold). LPG pretreatment (2 microM, 2 h) completely blocked endotoxin-mediated monocyte adhesion. LPG did not grossly suppress endothelial functions because TNF-alpha- and IL-1 beta-mediated adhesion toward monocytes were not affected. Using four highly purified LPG fragments (namely, repeating phosphodisaccharide (PGM), phosphoglycan, phosphosaccharide core-lyso-alkyl-phosphatidylinositol (core-PI), and lyso-alkyl-phosphatidylinositol (lyso-PI)), we examined whether these fragments can independently inhibit endothelial adhesion. In contrast to that of intact LPG, neither the four LPG fragments (2 microM, 2 h) independently nor the co-addition of phosphoglycan and core-P1 fragments blocked the endotoxin-mediated adhesion to monocytes. To determine whether the fragments can reverse the effect of intact LPG, endothelial cells were first pretreated with the LPG fragments (10 microM, 15 min), followed by the addition of LPG (2 microM). All four LPG fragments fully reversed the effect of LPG. Simultaneous addition of LPG fragments and intact LPG caused only partial suppression (approximately 45%), while the addition of LPG fragments 14 min later had no reversal effect. Flow cytometry revealed that only core-P1 and lyso-P1 competitively inhibited (approximately 30%) LPG binding. Conversely, LPG competed with the binding of [3H]lyso-P1 (approximately 30%). Furthermore, mAb against the PGM reversed (approximately 70%) the effect of LPG. Thus, the lyso-P1 domain on LPG mediates binding to endothelial cells, whereas the PGM domain mediates the cell inhibitory effect. PMID:8816410

  2. Dose Self-Esteem Mediates the Association Between Personality Traits and Happiness? A Structural Equation Modeling Approach

    OpenAIRE

    Nikolaos Tsigilis; Dalia Srebauite

    2015-01-01

    The present study was set out to explore the association among self-report happiness, personality traits and self-esteem in the Greek cultural setting. In particular, it was examined the mediating role of self-esteem on the relation of extraversion, neuroticism and happiness. In the study participated 207 Greek adults aged 25-60 years old. Three different questionnaires were administered to all participants: the Oxford Happiness Questionnaire (OHQ), the Eysenck Personality Questionnaire Revis...

  3. Enhancing Crystalline Structural Orders of Polymer Semiconductors for Efficient Charge Transport via Polymer-Matrix-Mediated Molecular Self-Assembly.

    Science.gov (United States)

    Lei, Yanlian; Deng, Ping; Lin, Ming; Zheng, Xuelin; Zhu, Furong; Ong, Beng S

    2016-08-01

    A facile polymer-matrix-mediated molecular self-assembly of polymer semiconductors into highly crystalline orders for efficient charge transport in organic thin-film transistors is demonstrated. Phenomenal enhancements in field-effect mobility of about one order of magnitude and current on/off ratio of two to three orders of magnitude are realized with polyacrylonitrile-incorporated polymer semiconductor compositions via solution deposition. PMID:27168128

  4. Structure of the thermophilic l-Arabinose isomerase from Geobacillus kaustophilus reveals metal-mediated intersubunit interactions for activity and thermostability.

    Science.gov (United States)

    Choi, Jin Myung; Lee, Yong-Jik; Cao, Thinh-Phat; Shin, Sun-Mi; Park, Min-Kyu; Lee, Han-Seung; di Luccio, Eric; Kim, Seong-Bo; Lee, Sang-Jae; Lee, Sang Jun; Lee, Sung Haeng; Lee, Dong-Woo

    2016-04-15

    Thermophilic l-arabinose isomerase (AI), which catalyzes the interconversion of l-arabinose and l-ribulose, can be used to produce d-tagatose, a sugar substitute, from d-galactose. Unlike mesophilic AIs, thermophilic AIs are highly dependent on divalent metal ions for their catalytic activity and thermostability at elevated temperatures. However, the molecular basis underlying the substrate preferences and metal requirements of multimeric AIs remains unclear. Here we report the first crystal structure of the apo and holo forms of thermophilic Geobacillus kaustophilus AI (GKAI) in hexamer form. The structures, including those of GKAI in complex with l-arabitol, and biochemical analyses revealed not only how the substrate-binding site of GKAI is formed through displacement of residues at the intersubunit interface when it is bound to Mn(2+), but also revealed the water-mediated H-bonding networks that contribute to the structural integrity of GKAI during catalysis. These observations suggest metal-mediated isomerization reactions brought about by intersubunit interactions at elevated temperatures are responsible for the distinct active site features that promote the substrate specificity and thermostability of thermophilic AIs. PMID:26946941

  5. Crystal structure of A. aeolicus argonaute, a site-specific DNA-guided endoribonuclease, provides insights into RISC-mediated mRNA cleavage

    Energy Technology Data Exchange (ETDEWEB)

    Yuan,Y.; Pei, Y.; Ma, J.; Kuryavyi, V.; Zhadina, M.; Meister, G.; Chen, H.; Dauter, Z.; Tuschi, T.; Patel, D.

    2005-01-01

    Argonaute (Ago) proteins constitute a key component of the RNA-induced silencing complex (RISC). We report the crystal structure of Aquifex aeolicus Ago (Aa-Ago) together with binding and cleavage studies, which establish this eubacterial Ago as a bona fide guide DNA strand-mediated site-specific RNA endonuclease. We have generated a stereochemically robust model of the complex, where the guide DNA-mRNA duplex is positioned within a basic channel spanning the bilobal interface, such that the 5' phosphate of the guide strand can be anchored in a basic pocket, and the mRNA can be positioned for site-specific cleavage by RNase H-type divalent cation-coordinated catalytic Asp residues of the PIWI domain. Domain swap experiments involving chimeras of human Ago (hAgo1) and cleavage-competent hAgo2 reinforce the role of the PIWI domain in 'slicer' activity. We propose a four-step Ago-mediated catalytic cleavage cycle model, which provides distinct perspectives into the mechanism of guide strand-mediated mRNA cleavage within the RISC.

  6. The Tripartite Influence model of body image and eating disturbance: a covariance structure modeling investigation testing the mediational role of appearance comparison.

    Science.gov (United States)

    van den Berg, Patricia; Thompson, J Kevin; Obremski-Brandon, Karen; Coovert, Michael

    2002-11-01

    Recent theoretical approaches to the etiology of eating disorders and body image disturbances have begun to focus on multifactorial models. In the current study, the Tripartite Influence model was examined in a large sample of college females (ages 18-22). This model proposes that three primary core sources of influence--parents, peers and media--contribute to the development of body image and eating disturbances. Additionally, the model suggests that at least two factors mediate the relationship between influences and disturbance-appearance comparison and internalization of media information. In this study, appearance comparison was examined as a mediational link between peer, family and media influence variables and the outcome disturbance measures of eating dysfunction and body image dissatisfaction. Covariance structure modeling (CSM) was used to test the proposed pathways. The results indicated that appearance comparison mediated the effects of family and media influences on body dissatisfaction, which in turn influenced restrictive and bulimic behaviors. In addition, peer influences had a direct influence on restriction. Perfectionism was hypothesized to relate to body dissatisfaction, but was in fact found to influence appearance comparison. The findings were limited by the necessity of several modifications to the originally proposed models, yet offer replication and extension of previous work with appearance comparison and support for further testing of the Tripartite Influence model. PMID:12445590

  7. Structure of MRDI Explains its Dual Function as a Metabolic Enzyme and a Mediator of Cell Invasion

    OpenAIRE

    Templeton, Paul D.; Litman, Elizabeth S.; Metzner, Sandra I.; Ahn, Natalie G.; Sousa, Marcelo C.

    2013-01-01

    Metastatic melanoma is among the most intractable cancers to treat, where patients show resistance to therapy and limited survival time. A critical step in the development of metastatic melanoma is the acquisition of invasion and transition from thin to thick tumors on the skin, followed by invasion to lymph nodes. Prior studies have shown that metastatic melanoma is associated with dysregulation of RhoA and enhanced expression of a protein named “mediator of RhoA-dependent invasion (MRDI)”. ...

  8. Evaluation of structure, chaperone-like activity and protective ability of peroxynitrite modified human α-Crystallin subunits against copper-mediated ascorbic acid oxidation.

    Science.gov (United States)

    Ghahramani, Maryam; Yousefi, Reza; Khoshaman, Kazem; Moghadam, Sogand Sasan; Kurganov, Boris I

    2016-06-01

    The copper-catalyzed oxidation of ascorbic acid (ASA) to dehydroascorbate (DHA) and hydrogen peroxide plays a central role in pathology of cataract diseases during ageing and in diabetic patients. In the current study, the structural feature, chaperone-like activity and protective ability of peroxynitrite (PON) modified αA- and αB-Crystallin (Cry) against copper-mediated ASA oxidation were studied using different spectroscopic measurements and gel mobility shift assay. Upon PON modification, additional to protein structural alteration, the contents of nitrotyrosine, nitrotryptophan, dityrosine and carbonyl groups were significantly increased. Moreover, αB-Cry demonstrates significantly larger capacity for PON modification than αA-Cry. Also, based on the extent of PON modification, these proteins may display an improved chaperone-like activity and enhanced protective ability against copper-mediated ASA oxidation. In the presence of copper ions, chaperone-like activity of both native and PON-modified α-Cry subunits were appreciably improved. Additionally, binding of copper ions to native and PON-modified proteins results in the significant reduction of their solvent exposed hydrophobic patches. Overall, the increase in chaperone-like activity/ASA protective ability of PON-modified α-Cry and additional enhancement of its chaperoning action with copper ions appear to be an important defense mechanism offered by this protein. PMID:26896727

  9. Interactive ion-mediated sap flow regulation in olive and laurel stems: physicochemical characteristics of water transport via the pit structure.

    Directory of Open Access Journals (Sweden)

    Jeongeun Ryu

    Full Text Available Sap water is distributed and utilized through xylem conduits, which are vascular networks of inert pipes important for plant survival. Interestingly, plants can actively regulate water transport using ion-mediated responses and adapt to environmental changes. However, ionic effects on active water transport in vascular plants remain unclear. In this report, the interactive ionic effects on sap transport were systematically investigated for the first time by visualizing the uptake process of ionic solutions of different ion compositions (K+/Ca2+ using synchrotron X-ray and neutron imaging techniques. Ionic solutions with lower K+/Ca2+ ratios induced an increased sap flow rate in stems of Olea europaea L. and Laurus nobilis L. The different ascent rates of ionic solutions depending on K+/Ca2+ ratios at a fixed total concentration increases our understanding of ion-responsiveness in plants from a physicochemical standpoint. Based on these results, effective structural changes in the pit membrane were observed using varying ionic ratios of K+/Ca2+. The formation of electrostatically induced hydrodynamic layers and the ion-responsiveness of hydrogel structures based on Hofmeister series increase our understanding of the mechanism of ion-mediated sap flow control in plants.

  10. Structure sensitive chemical reactivity by palladium concave nanocubes and nanoflowers synthesised by a seed mediated procedure in aqueous medium

    Science.gov (United States)

    Sreedhala, S.; Sudheeshkumar, V.; Vinod, C. P.

    2014-06-01

    Palladium nanocubes and their transformation to concave nanocubes and nanoflowers are realised by a seed mediated procedure in aqueous medium and at room temperature using cationic surfactants. The concave nanocubes and nanoflowers were found to be enclosed by high index facets. The under co-ordinated atoms present on the high index facets make these nanostructures chemically more active towards Suzuki coupling and Heck coupling reactions compared to the conventional nanocubes and spherical nanoparticles of similar size.Palladium nanocubes and their transformation to concave nanocubes and nanoflowers are realised by a seed mediated procedure in aqueous medium and at room temperature using cationic surfactants. The concave nanocubes and nanoflowers were found to be enclosed by high index facets. The under co-ordinated atoms present on the high index facets make these nanostructures chemically more active towards Suzuki coupling and Heck coupling reactions compared to the conventional nanocubes and spherical nanoparticles of similar size. Electronic supplementary information (ESI) available: Additional HRTEM images, UV-Vis spectra and details of TOF calculation. See DOI: 10.1039/c4nr01283f

  11. Structure-based network analysis of activation mechanisms in the ErbB family of receptor tyrosine kinases: the regulatory spine residues are global mediators of structural stability and allosteric interactions.

    Directory of Open Access Journals (Sweden)

    Kevin A James

    Full Text Available The ErbB protein tyrosine kinases are among the most important cell signaling families and mutation-induced modulation of their activity is associated with diverse functions in biological networks and human disease. We have combined molecular dynamics simulations of the ErbB kinases with the protein structure network modeling to characterize the reorganization of the residue interaction networks during conformational equilibrium changes in the normal and oncogenic forms. Structural stability and network analyses have identified local communities integrated around high centrality sites that correspond to the regulatory spine residues. This analysis has provided a quantitative insight to the mechanism of mutation-induced "superacceptor" activity in oncogenic EGFR dimers. We have found that kinase activation may be determined by allosteric interactions between modules of structurally stable residues that synchronize the dynamics in the nucleotide binding site and the αC-helix with the collective motions of the integrating αF-helix and the substrate binding site. The results of this study have pointed to a central role of the conserved His-Arg-Asp (HRD motif in the catalytic loop and the Asp-Phe-Gly (DFG motif as key mediators of structural stability and allosteric communications in the ErbB kinases. We have determined that residues that are indispensable for kinase regulation and catalysis often corresponded to the high centrality nodes within the protein structure network and could be distinguished by their unique network signatures. The optimal communication pathways are also controlled by these nodes and may ensure efficient allosteric signaling in the functional kinase state. Structure-based network analysis has quantified subtle effects of ATP binding on conformational dynamics and stability of the EGFR structures. Consistent with the NMR studies, we have found that nucleotide-induced modulation of the residue interaction networks is not

  12. Gravity in gauge mediation

    International Nuclear Information System (INIS)

    We investigate O'Raifeartaigh-type models for F-term supersymmetry breaking in gauge mediation scenarios in the presence of gravity. It is pointed out that the vacuum structure of those models is such that in metastable vacua gravity mediation contribution to scalar masses is always suppressed to the level below 1 percent, almost sufficient for avoiding FCNC problem. Close to that limit, gravitino mass can be in the range 10-100 GeV, opening several interesting possibilities for gauge mediation models, including Giudice-Masiero mechanism for μ and Bμ generation. Gravity sector can include stabilized moduli.

  13. Evidence for small-molecule-mediated loop stabilization in the structure of the isolated Pin1 WW domain

    Energy Technology Data Exchange (ETDEWEB)

    Mortenson, David E.; Kreitler, Dale F.; Yun, Hyun Gi; Gellman, Samuel H., E-mail: gellman@chem.wisc.edu; Forest, Katrina T., E-mail: gellman@chem.wisc.edu [University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2013-12-01

    Two structures of a small protein with a defined tertiary fold, the isolated Pin1 WW domain, have been determined via racemic crystallization with small-molecule additives. These additives, which are either racemic or achiral, appear to stabilize a dynamic loop region of the structure. The human Pin1 WW domain is a small autonomously folding protein that has been useful as a model system for biophysical studies of β-sheet folding. This domain has resisted previous attempts at crystallization for X-ray diffraction studies, perhaps because of intrinsic conformational flexibility that interferes with the formation of a crystal lattice. Here, the crystal structure of the human Pin1 WW domain has been obtained via racemic crystallization in the presence of small-molecule additives. Both enantiomers of a 36-residue variant of the Pin1 WW domain were synthesized chemically, and the l- and d-polypeptides were combined to afford diffracting crystals. The structural data revealed packing interactions of small carboxylic acids, either achiral citrate or a d,l mixture of malic acid, with a mobile loop region of the WW-domain fold. These interactions with solution additives may explain our success in crystallization of this protein racemate. Molecular-dynamics simulations starting from the structure of the Pin1 WW domain suggest that the crystal structure closely resembles the conformation of this domain in solution. The structural data presented here should provide a basis for further studies of this important model system.

  14. Evidence for small-molecule-mediated loop stabilization in the structure of the isolated Pin1 WW domain

    International Nuclear Information System (INIS)

    Two structures of a small protein with a defined tertiary fold, the isolated Pin1 WW domain, have been determined via racemic crystallization with small-molecule additives. These additives, which are either racemic or achiral, appear to stabilize a dynamic loop region of the structure. The human Pin1 WW domain is a small autonomously folding protein that has been useful as a model system for biophysical studies of β-sheet folding. This domain has resisted previous attempts at crystallization for X-ray diffraction studies, perhaps because of intrinsic conformational flexibility that interferes with the formation of a crystal lattice. Here, the crystal structure of the human Pin1 WW domain has been obtained via racemic crystallization in the presence of small-molecule additives. Both enantiomers of a 36-residue variant of the Pin1 WW domain were synthesized chemically, and the l- and d-polypeptides were combined to afford diffracting crystals. The structural data revealed packing interactions of small carboxylic acids, either achiral citrate or a d,l mixture of malic acid, with a mobile loop region of the WW-domain fold. These interactions with solution additives may explain our success in crystallization of this protein racemate. Molecular-dynamics simulations starting from the structure of the Pin1 WW domain suggest that the crystal structure closely resembles the conformation of this domain in solution. The structural data presented here should provide a basis for further studies of this important model system

  15. Structural basis of the zinc- and terbium-mediated inhibition of ferroxidase activity in Dps ferritin-like proteins

    OpenAIRE

    Havukainen, Heli; Haataja, Sauli; Kauko, Anni; Pulliainen, Arto T.; Salminen, Annika; Haikarainen, Teemu; Finne, Jukka; Papageorgiou, Anastassios C.

    2008-01-01

    Streptococcus suis Dpr is an iron-binding protein involved in oxidative stress resistance. It belongs to the bacterial Dps protein family whose members form dodecameric assemblies. Previous studies have shown that zinc and terbium inhibit iron incorporation in Listeria innocua Dps protein. In order to gain structural insights into the inhibitory effect of zinc and terbium, the crystal structures of Streptococcus suis Dpr complexes with these ions were determined at 1.8 Å and 2.1 Å, respective...

  16. Structural basis of SETD6-mediated regulation of the NF-kB network via methyl-lysine signaling

    Science.gov (United States)

    Chang, Yanqi; Levy, Dan; Horton, John R.; Peng, Junmin; Zhang, Xing; Gozani, Or; Cheng, Xiaodong

    2011-01-01

    SET domain containing 6 (SETD6) monomethylates the RelA subunit of nuclear factor kappa B (NF-κB). The ankyrin repeats of G9a-like protein (GLP) recognizes RelA monomethylated at Lys310. Adjacent to Lys310 is Ser311, a known phosphorylation site of RelA. Ser311 phosphorylation inhibits Lys310 methylation by SETD6 as well as binding of Lys310me1 by GLP. The structure of SETD6 in complex with RelA peptide containing the methylation site, in the presence of S-adenosyl-l-methionine, reveals a V-like protein structure and suggests a model for NF-κB binding to SETD6. In addition, structural modeling of the GLP ankyrin repeats bound to Lys310me1 peptide provides insight into the molecular basis for inhibition of Lys310me1 binding by Ser311 phosphorylation. Together, these findings provide a structural explanation for a key cellular signaling pathway centered on RelA Lys310 methylation, which is generated by SETD6 and recognized by GLP, and incorporate a methylation–phosphorylation switch of adjacent lysine and serine residues. Finally, SETD6 is structurally similar to the Rubisco large subunit methyltransferase. Given the restriction of Rubisco to plant species, this particular appearance of the protein lysine methyltransferase has been evolutionarily well conserved. PMID:21515635

  17. Structural basis of SETD6-mediated regulation of the NF-kB network via methyl-lysine signaling

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yanqi; Levy, Dan; Horton, John R.; Peng, Junmin; Zhang, Xing; Gozani, Or; Cheng, Xiaodong (Emory-MED); (Stanford)

    2011-10-10

    SET domain containing 6 (SETD6) monomethylates the RelA subunit of nuclear factor kappa B (NF-{kappa}B). The ankyrin repeats of G9a-like protein (GLP) recognizes RelA monomethylated at Lys310. Adjacent to Lys310 is Ser311, a known phosphorylation site of RelA. Ser311 phosphorylation inhibits Lys310 methylation by SETD6 as well as binding of Lys310me1 by GLP. The structure of SETD6 in complex with RelA peptide containing the methylation site, in the presence of S-adenosyl-l-methionine, reveals a V-like protein structure and suggests a model for NF-{kappa}B binding to SETD6. In addition, structural modeling of the GLP ankyrin repeats bound to Lys310me1 peptide provides insight into the molecular basis for inhibition of Lys310me1 binding by Ser311 phosphorylation. Together, these findings provide a structural explanation for a key cellular signaling pathway centered on RelA Lys310 methylation, which is generated by SETD6 and recognized by GLP, and incorporate a methylation-phosphorylation switch of adjacent lysine and serine residues. Finally, SETD6 is structurally similar to the Rubisco large subunit methyltransferase. Given the restriction of Rubisco to plant species, this particular appearance of the protein lysine methyltransferase has been evolutionarily well conserved.

  18. Photochemical synthesis of bimetallic Au-Ag nanoparticles with "core-shell" type structure by seed mediated catalytic growth

    Institute of Scientific and Technical Information of China (English)

    DONG Shou-an; TANG Chun

    2005-01-01

    The colloidal Au core/Ag shell structure composite nanoparticles were synthesized in PEG-acetone solution by photochemical route. The monodispersed Au nanoparticles with average diameter of 3.9 nm were used as growth seeds. The optical property of colloids and the sizes of composite nanoparticles were characterized when the molar ratio of Au to Ag ranges from 4 : 1 to 1 : 4. The results show that a composite nanoparticle structure similar to strawberry shape is formed at the molar ratio of Au to Ag from 4 : 1 to 1 : 1; the composite nanoparticles consisting of a core of Au and shell of Ag were generated at the 1: 4 molar ratio, having a striking feature of forming interconnected network structure.

  19. Solvent and Water Mediated Structural Variations in Deoxynivalenol and Their Potential Implications on the Disruption of Ribosomal Function.

    Science.gov (United States)

    Foroud, Nora A; Shank, Roxanne A; Kiss, Douglas; Eudes, François; Hazendonk, Paul

    2016-01-01

    Fusarium head blight (FHB) is a disease of cereal crops caused by trichothecene producing Fusarium species. Trichothecenes, macrocylicic fungal metabolites composed of three fused rings (A-C) with one epoxide functionality, are a class of mycotoxins known to inhibit protein synthesis in eukaryotic ribosomes. These toxins accumulate in the kernels of infected plants rendering them unsuitable for human and animal consumption. Among the four classes of trichothecenes (A-D) A and B are associated with FHB, where the type B trichothecene deoxynivalenol (DON) is most relevant. While it is known that these toxins inhibit protein synthesis by disrupting peptidyl transferase activity, the exact mechanism of this inhibition is poorly understood. The three-dimensional structures and H-bonding behavior of DON were evaluated using one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy techniques. Comparisons of the NMR structure presented here with the recently reported crystal structure of DON bound in the yeast ribosome reveal insights into the possible toxicity mechanism of this compound. The work described herein identifies a water binding pocket in the core structure of DON, where the 3OH plays an important role in this interaction. These results provide preliminary insights into how substitution at C3 reduces trichothecene toxicity. Further investigations along these lines will provide opportunities to develop trichothecene remediation strategies based on the disruption of water binding interactions with 3OH. PMID:27582730

  20. The saponin-mediated enhanced uptake of targeted saporin-based drugs is strongly dependent on the saponin structure.

    Science.gov (United States)

    Bachran, Christopher; Sutherland, Mark; Heisler, Iring; Hebestreit, Philipp; Melzig, Matthias F; Fuchs, Hendrik

    2006-04-01

    Saponins are a group of plant glycosides consisting of a steroid or triterpenoid aglycone to which one or more sugar chains are attached. They exhibit cell membrane-permeabilizing properties and, thus, have been investigated for their therapeutic potential. Recently, at a non-permeabilizing concentration saponinum album from Gypsophila paniculata L. has been described to enhance the cytotoxicity of a chimeric toxin in a cell culture model. To elucidate whether this enhancing effect is also mediated by other saponins, we analyzed the ability of seven different saponins to enhance the cytotoxicity of a targeted chimeric toxin. The chimeric toxin is composed of saporin, a plant ribosome-inactivating toxin, a cleavable adapter, and human epidermal growth factor (EGF). Cytotoxicity on EGF receptor (EGFR)-bearing cells was analyzed both alone and after combined application of saponin and chimeric toxin. Only two of the tested saponins, quillajasaponin and saponinum album, enhanced cytotoxicity by more than 1,000-fold, whereas the enhancement factors of the other saponins were only approximately 10-fold. In contrast to saponinum album, quillajasaponin enhanced the cytotoxicity both on control cells lacking EGFR and on target cells, indicating that, in this case, the enhancement is not target cell receptor specific. This is also the case for some of the saponins with low enhancement factors. Saponinum album resulted in a more than 13,600-fold receptor-specific enhancement, decreasing the 50% inhibitory concentration (IC(50)) from 2.4 nM to 0.18 pM, which renders it the best option to promote saporin-3-based drug uptake while retaining specificity for the EGFR. PMID:16565437

  1. Complex Mediation

    DEFF Research Database (Denmark)

    Bødker, Susanne; Andersen, Peter Bøgh

    2005-01-01

    This article has its starting point in a large number of empirical findings regarding computer-mediated work. These empirical findings have challenged our understanding of the role of mediation in such work; on the one hand as an aspect of communication and cooperation at work and on the other ha...

  2. Specialized Mediation.

    Science.gov (United States)

    Hammond, Carol; And Others

    1992-01-01

    Six articles discuss librarians as mediators in special circumstances. Highlights include the reference librarian and the information paraprofessional; effective reference mediation for nontraditional public library users, including mentally impaired patrons and illiterate adults; the academic librarian's role in the education process; and…

  3. A Common Structural Component for β-Subunit Mediated Modulation of Slow Inactivation in Different KV Channels

    DEFF Research Database (Denmark)

    Strutz-Seebohm, Nathalie; Henrion, Ulrike; Schmitt, Nicole;

    2013-01-01

    inactivation by structurally dissimilar β-subunits in different KV channels. Conclusion: We propose a model in which structural changes accompanying activation and β-subunit modulation allosterically constrain the backbone carbonyl oxygen atoms via the side chain of the respective X-residue in the signature......Background/Aims: Potassium channels are tetrameric proteins providing potassium selective passage through lipid embedded proteinaceous pores with highest fidelity. The selectivity results from binding to discrete potassium binding sites and stabilization of a hydrated potassium ion in a central...... internal cavity. The four potassium binding sites, generated by the conserved TTxGYGD signature sequence are formed by the backbone carbonyls of the amino acids TXGYG. Residues KV1.5-Val481, KV4.3-Leu368 and KV7.1- Ile 313 represent the amino acids in the X position of the respective channels. Methods...

  4. Structure of the Membrane-tethering GRASP Domain Reveals a Unique PDZ Ligand Interaction That Mediates Golgi Biogenesis*

    OpenAIRE

    Truschel, Steven T.; Sengupta, Debrup; Foote, Adam; Heroux, Annie; Macbeth, Mark R.; Linstedt, Adam D.

    2011-01-01

    Biogenesis of the ribbon-like membrane network of the mammalian Golgi requires membrane tethering by the conserved GRASP domain in GRASP65 and GRASP55, yet the tethering mechanism is not fully understood. Here, we report the crystal structure of the GRASP55 GRASP domain, which revealed an unusual arrangement of two tandem PDZ folds that more closely resemble prokaryotic PDZ domains. Biochemical and functional data indicated that the interaction between the ligand-binding pocket of PDZ1 and an...

  5. Structural study of TTR-52 reveals the mechanism by which a bridging molecule mediates apoptotic cell engulfment

    OpenAIRE

    Kang, Yanyong; Zhao, Dongfeng; Liang, Huanhuan; Liu, Bin; Zhang, Yan; Liu, Qinwen; Wang, Xiaochen; Liu, Yingfang

    2012-01-01

    Apoptotic cells display various “eat me” signals that can be recognized through bridging molecules that cross-link the dying cells to phagocytes. This work illustrates the first full-length structure of such a bridging molecule, TTR-52. The study elucidates the binding of these bridging molecules with the apoptotic cell signals and phagocyte receptors, providing valuable new insight into the process of apoptotic cell recognition.

  6. Conserved waters mediate structural and functional activation of family A (rhodopsin-like) G protein-coupled receptors

    Energy Technology Data Exchange (ETDEWEB)

    Angel, T.; Chance, M; Palczewski, K

    2009-01-01

    G protein-coupled receptors with seven transmembrane {alpha}-helices (GPCRs) comprise the largest receptor superfamily and are involved in detecting a wide variety of extracellular stimuli. The availability of high-resolution crystal structures of five prototypical GPCRs, bovine and squid rhodopsin, engineered A2A-adenosine, {beta}1- and {beta}2-adrenergic receptors, permits comparative analysis of features common to these and likely all GPCRs. We provide an analysis of the distribution of water molecules in the transmembrane region of these GPCR structures and find conserved contacts with microdomains demonstrated to be involved in receptor activation. Colocalization of water molecules associating with highly conserved and functionally important residues in several of these GPCR crystal structures supports the notion that these waters are likely to be as important to proper receptor function as the conserved residues. Moreover, in the absence of large conformational changes in rhodopsin after photoactivation, we propose that ordered waters contribute to the functional plasticity needed to transmit activation signals from the retinal-binding pocket to the cytoplasmic face of rhodopsin and that fundamental features of the mechanism of activation, involving these conserved waters, are shared by many if not all family A receptors.

  7. Implications of fire-mediated changes in larch forest structure on leaf litter inputs, organic layer accumulation, and permafrost dynamics

    Science.gov (United States)

    Ganzlin, P.; Alexander, H. D.; Petronio, B.; Natali, S.; Davydov, S.

    2012-12-01

    The boreal forest is an expansive biome and stores the majority of the world's above and belowground carbon stocks. These forests are very vulnerable to changes in global climate. As climate warms and dries, boreal forest ecosystems are expected to experience greater fire activity. An increase in fire activity will likely lead to greater consumption of the soil organic layer (SOL), the thick layer of undecomposed mosses and other plant materials lying above the mineral soil. Because the SOL serves as a natural barrier to seed germination, a reduction in SOL depth could increase tree seedling establishment during post-fire succession. This could ultimately lead to stands of greater density, with potentially cascading effects on belowground carbon dynamics due to density-driven changes in understory microenvironment and leaf litter inputs, especially in forests dominated by deciduous species. In permafrost-affected regions, organic soil materials - especially mosses - are important insulators of permafrost and the high content of thermally protected carbon it contains. In order to assess the importance of fire-mediated changes in stand density on permafrost dynamics, we surveyed forests of Cajander Larch (Larix cajander) surrounding the Northeast Science Station in far northeastern Siberia. Two sets of low and high-density stands were selected to establish a natural density gradient in these forests. In each stand we evaluated stand density effects on aboveground biomass, leaf litter inputs, moss abundance, organic layer depth, and permafrost thaw depth. Here we show that the low-density larch stands had significantly higher moss abundance, green moss depth, and organic layer depth. The insulating organic layer was nearly 25% shallower in high-density stands, which was accompanied by a nearly 50% increase in depth of seasonal permafrost thaw. In addition to density, stand biomass and landscape position may also be very important factors in determining litter inputs

  8. A Graphical Representation of the Mediated Effect

    OpenAIRE

    Fritz, Matthew S.; David P. MacKinnon

    2008-01-01

    Mediation analysis is widely used in the social sciences. Despite the popularity of mediation models, few researchers have used graphical methods, other than structural path diagrams, to represent their models. Plots of the mediated effect can help a researcher better understand the results of the analysis and convey these results to others. This article presents a method for creating and interpreting plots of the mediated effect for a variety of mediation models, including models with a dich...

  9. PRED treatment mediated stable and efficient water oxidation performance of the Fe2O3 nano-coral structure

    Science.gov (United States)

    Shinde, Pravin S.; Lee, Hyun Hwi; Lee, Su Yong; Lee, Young Mi; Jang, Jum Suk

    2015-09-01

    Herein, we demonstrate that an electrochemical surface treatment of Fe foil with simple pulse reverse electrodeposition (PRED) prior to thermal oxidation can substantially enhance the photoelectrochemical (PEC) stability and water splitting performance of Fe2O3/Fe photoanodes. Comprehensive structural (XRD, FESEM, and HRTEM), compositional (XPS depth profiling), and electrochemical (EIS and Mott-Schottky) analyses were performed to understand the effect of PRED treatment on the PEC performance of fabricated photoanodes. It is revealed that air-exposed Fe foil is prone to formation of a loosely bound surface oxide layer that, upon annealing at 800 °C, results in an unstable Fe2O3 nano-flake (2-3 μm long) morphology. In contrast, when such Fe foil is pre-treated with PRED to etch the loosely bound oxide layer, adherent inverse-opal-like nano-coral structures (60-100 nm thin) are formed. In addition to stability improvement, PRED-treatment also assists in exposing the photocatalytically active high index [104] facet sites of hematite. Thin hematite nano-coral structures with high index [104] facet sites significantly improved the separation of photo-generated charge carriers and oxygen evolution kinetics, resulting in performance enhancement with excellent photocurrent stability for extended duration in a 1 M NaOH solution under one sun illumination. The net photocurrent density for nano-coral morphology was 0.813 mA cm-2 at 1.23 V vs. RHE, which is the highest reported value for pristine hematite photoanodes fabricated from Fe foil.Herein, we demonstrate that an electrochemical surface treatment of Fe foil with simple pulse reverse electrodeposition (PRED) prior to thermal oxidation can substantially enhance the photoelectrochemical (PEC) stability and water splitting performance of Fe2O3/Fe photoanodes. Comprehensive structural (XRD, FESEM, and HRTEM), compositional (XPS depth profiling), and electrochemical (EIS and Mott-Schottky) analyses were performed to

  10. Flavoprotein-Mediated Tellurite Reduction: Structural Basis and Applications to the Synthesis of Tellurium-Containing Nanostructures

    Science.gov (United States)

    Arenas-Salinas, Mauricio; Vargas-Pérez, Joaquín I.; Morales, Wladimir; Pinto, Camilo; Muñoz-Díaz, Pablo; Cornejo, Fabián A.; Pugin, Benoit; Sandoval, Juan M.; Díaz-Vásquez, Waldo A.; Muñoz-Villagrán, Claudia; Rodríguez-Rojas, Fernanda; Morales, Eduardo H.; Vásquez, Claudio C.; Arenas, Felipe A.

    2016-01-01

    The tellurium oxyanion tellurite (TeO32-) is extremely harmful for most organisms. It has been suggested that a potential bacterial tellurite resistance mechanism would consist of an enzymatic, NAD(P)H-dependent, reduction to the less toxic form elemental tellurium (Te0). To date, a number of enzymes such as catalase, type II NADH dehydrogenase and terminal oxidases from the electron transport chain, nitrate reductases, and dihydrolipoamide dehydrogenase (E3), among others, have been shown to display tellurite-reducing activity. This activity is generically referred to as tellurite reductase (TR). Bioinformatic data resting on some of the abovementioned enzymes enabled the identification of common structures involved in tellurite reduction including vicinal catalytic cysteine residues and the FAD/NAD(P)+-binding domain, which is characteristic of some flavoproteins. Along this line, thioredoxin reductase (TrxB), alkyl hydroperoxide reductase (AhpF), glutathione reductase (GorA), mercuric reductase (MerA), NADH: flavorubredoxin reductase (NorW), dihydrolipoamide dehydrogenase, and the putative oxidoreductase YkgC from Escherichia coli or environmental bacteria were purified and assessed for TR activity. All of them displayed in vitro TR activity at the expense of NADH or NADPH oxidation. In general, optimal reducing conditions occurred around pH 9–10 and 37°C. Enzymes exhibiting strong TR activity produced Te-containing nanostructures (TeNS). While GorA and AhpF generated TeNS of 75 nm average diameter, E3 and YkgC produced larger structures (>100 nm). Electron-dense structures were observed in cells over-expressing genes encoding TrxB, GorA, and YkgC. PMID:27507969

  11. Basin-wide variations in Amazon forest structure and function are mediated by both soils and climate

    Directory of Open Access Journals (Sweden)

    C. A. Quesada

    2012-06-01

    Full Text Available Forest structure and dynamics vary across the Amazon Basin in an east-west gradient coincident with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates.

    Soil samples were collected in a total of 59 different forest plots across the Amazon Basin and analysed for exchangeable cations, carbon, nitrogen and pH, with several phosphorus fractions of likely different plant availability also quantified. Physical properties were additionally examined and an index of soil physical quality developed. Bivariate relationships of soil and climatic properties with above-ground wood productivity, stand-level tree turnover rates, above-ground wood biomass and wood density were first examined with multivariate regression models then applied. Both forms of analysis were undertaken with and without considerations regarding the underlying spatial structure of the dataset.

    Despite the presence of autocorrelated spatial structures complicating many analyses, forest structure and dynamics were found to be strongly and quantitatively related to edaphic as well as climatic conditions. Basin-wide differences in stand-level turnover rates are mostly influenced by soil physical properties with variations in rates of coarse wood production mostly related to soil phosphorus status. Total soil P was a better predictor of wood production rates than any of the fractionated organic- or inorganic-P pools. This suggests that it is not only the immediately available P forms, but probably the entire soil phosphorus pool that is interacting with forest growth on longer timescales.

    A role for soil potassium in modulating Amazon forest dynamics through its effects on stand-level wood density was also detected. Taking this into account, otherwise enigmatic variations in stand-level biomass across the

  12. Modified siRNA Structure With a Single Nucleotide Bulge Overcomes Conventional siRNA-mediated Off-target Silencing

    OpenAIRE

    Dua, Pooja; Yoo, Jae Wook; Kim, Soyoun; Lee, Dong-ki

    2011-01-01

    Off-target gene silencing is a major concern when using RNA interference. Imperfect pairing of the antisense strand with unintended mRNA targets is one of the main causes of small interfering RNA (siRNA) off-target silencing. To overcome this, we have developed “bulge-siRNA,” a modified siRNA backbone structure with a single nucleotide (nt) bulge placed in the antisense strand. We found that siRNAs with a bulge at position 2 of the antisense strand were able to discriminate better between per...

  13. Structural and functional insight into how the Plasmodium falciparum VAR2CSA protein mediates binding to chondroitin sulfate A in placental malaria.

    Science.gov (United States)

    Clausen, Thomas M; Christoffersen, Stig; Dahlbäck, Madeleine; Langkilde, Annette Eva; Jensen, Kamilla E; Resende, Mafalda; Agerbæk, Mette Ø; Andersen, Daniel; Berisha, Besim; Ditlev, Sisse B; Pinto, Vera V; Nielsen, Morten A; Theander, Thor G; Larsen, Sine; Salanti, Ali

    2012-07-01

    Malaria is a major global health problem. Pregnant women are susceptible to infection regardless of previously acquired immunity. Placental malaria is caused by parasites capable of sequestering in the placenta. This is mediated by VAR2CSA, a parasite antigen that interacts with chondroitin sulfate A (CSA). One vaccine strategy is to block this interaction with VAR2CSA-specific antibodies. It is a priority to define a small VAR2CSA fragment that can be used in an adhesion blocking vaccine. In this, the obvious approach is to define regions of VAR2CSA involved in receptor binding. It has been shown that full-length recombinant VAR2CSA binds specifically to CSA with nanomolar affinity, and that the CSA-binding site lies in the N-terminal part of the protein. In this study we define the minimal binding region by truncating VAR2CSA and analyzing CSA binding using biosensor technology. We show that the core CSA-binding site lies within the DBL2X domain and parts of the flanking interdomain regions. This is in contrast to the idea that single domains do not possess the structural requirements for specific CSA binding. Small-angle x-ray scattering measurements enabled modeling of VAR2CSA and showed that the CSA-binding DBL2X domain is situated in the center of the structure. Mutating classic sulfate-binding sites in VAR2CSA, along with testing dependence of ionic interactions, suggest that the CSA binding is not solely dependent on the sulfated CSA structure. Based on these novel PfEMP1 structure-function studies, we have constructed a small VAR2CSA antigen that has the capacity to induce highly adhesion-blocking antibodies. PMID:22570492

  14. Structure and function of broadly reactive antibody PG16 reveal an H3 subdomain that mediates potent neutralization of HIV-1

    Energy Technology Data Exchange (ETDEWEB)

    Pejchal, Robert; Walker, Laura M.; Stanfield, Robyn L.; Phogat, Sanjay K.; Koff, Wayne C.; Poignard, Pascal; Burton, Dennis R.; Wilson, Ian A. (Scripps); (IAVI)

    2010-11-15

    Development of an effective vaccine against HIV-1 will likely require elicitation of broad and potent neutralizing antibodies against the trimeric surface envelope glycoprotein (Env). Monoclonal antibodies (mAbs) PG9 and PG16 neutralize {approx}80% of HIV-1 isolates across all clades with extraordinary potency and target novel epitopes preferentially expressed on Env trimers. As these neutralization properties are ideal for a vaccine-elicited antibody response to HIV-1, their structural basis was investigated. The crystal structure of the antigen-binding fragment (Fab) of PG16 at 2.5 {angstrom} resolution revealed its unusually long, 28-residue, complementarity determining region (CDR) H3 forms a unique, stable subdomain that towers above the antibody surface. A 7-residue 'specificity loop' on the 'hammerhead' subdomain was identified that, when transplanted from PG16 to PG9 and vice versa, accounted for differences in the fine specificity and neutralization of these two mAbs. The PG16 electron density maps also revealed that a CDR H3 tyrosine was sulfated, which was confirmed for both PG9 (doubly) and PG16 (singly) by mass spectral analysis. We further showed that tyrosine sulfation plays a role in binding and neutralization. An N-linked glycan modification is observed in the variable light chain, but not required for antigen recognition. Further, the crystal structure of the PG9 light chain at 3.0 {angstrom} facilitated homology modeling to support the presence of these unusual features in PG9. Thus, PG9 and PG16 use unique structural features to mediate potent neutralization of HIV-1 that may be of utility in antibody engineering and for high-affinity recognition of a variety of therapeutic targets.

  15. Structural and Functional Insight into How the Plasmodium falciparum VAR2CSA Protein Mediates Binding to Chondroitin Sulfate A in Placental Malaria*

    Science.gov (United States)

    Clausen, Thomas M.; Christoffersen, Stig; Dahlbäck, Madeleine; Langkilde, Annette Eva; Jensen, Kamilla E.; Resende, Mafalda; Agerbæk, Mette Ø.; Andersen, Daniel; Berisha, Besim; Ditlev, Sisse B.; Pinto, Vera V.; Nielsen, Morten A.; Theander, Thor G.; Larsen, Sine; Salanti, Ali

    2012-01-01

    Malaria is a major global health problem. Pregnant women are susceptible to infection regardless of previously acquired immunity. Placental malaria is caused by parasites capable of sequestering in the placenta. This is mediated by VAR2CSA, a parasite antigen that interacts with chondroitin sulfate A (CSA). One vaccine strategy is to block this interaction with VAR2CSA-specific antibodies. It is a priority to define a small VAR2CSA fragment that can be used in an adhesion blocking vaccine. In this, the obvious approach is to define regions of VAR2CSA involved in receptor binding. It has been shown that full-length recombinant VAR2CSA binds specifically to CSA with nanomolar affinity, and that the CSA-binding site lies in the N-terminal part of the protein. In this study we define the minimal binding region by truncating VAR2CSA and analyzing CSA binding using biosensor technology. We show that the core CSA-binding site lies within the DBL2X domain and parts of the flanking interdomain regions. This is in contrast to the idea that single domains do not possess the structural requirements for specific CSA binding. Small-angle x-ray scattering measurements enabled modeling of VAR2CSA and showed that the CSA-binding DBL2X domain is situated in the center of the structure. Mutating classic sulfate-binding sites in VAR2CSA, along with testing dependence of ionic interactions, suggest that the CSA binding is not solely dependent on the sulfated CSA structure. Based on these novel PfEMP1 structure-function studies, we have constructed a small VAR2CSA antigen that has the capacity to induce highly adhesion-blocking antibodies. PMID:22570492

  16. The rhizosphere and PAH amendment mediate impacts on functional and structural bacterial diversity in sandy peat soil

    Energy Technology Data Exchange (ETDEWEB)

    Yrjaelae, Kim, E-mail: kim.yrjala@helsinki.f [Department of Biological and Environmental Sciences, General Microbiology, University of Helsinki, P.O. Box 56, (Biocenter 1C), 00014 Helsinki (Finland); Keskinen, Anna-Kaisa; Akerman, Marja-Leena; Fortelius, Carola [METROPOLIA University of Applied Science, Vantaa (Finland); Sipilae, Timo P. [Department of Biological and Environmental Sciences, General Microbiology, University of Helsinki, P.O. Box 56, (Biocenter 1C), 00014 Helsinki (Finland)

    2010-05-15

    To reveal the degradation capacity of bacteria in PAH polluted soil and rhizosphere we combined bacterial extradiol ring-cleavage dioxygenase and 16S rRNA analysis in Betula pubescens rhizoremediation. Characterisation of the functional bacterial community by RFLP revealed novel environmental dioxygenases, and their putative hosts were studied by 16S rRNA amplification. Plant rhizosphere and PAH amendment effects were detected by the RFLP/T-RFLP analysis. Functional species richness increased in the birch rhizosphere and PAH amendment impacted the compositional diversity of the dioxygenases and the structural 16S rRNA community. A shift from an Acidobacteria and Verrucomicrobia dominated to an Alpha- and Betaproteobacteria dominated community structure was detected in polluted soil. Clone sequence analysis indicated catabolic significance of Burkholderia in PAH polluted soil. These results advance our understanding of rhizoremediation and unveil the extent of uncharacterized functional bacteria to benefit bioremediation by facilitating the development of the molecular tool box to monitor bacterial populations in biodegradation. - The bacterial community analysis using 16S rRNA and extradiol dioxygenase marker genes in rhizoremediation revealed both a rhizosphere and a PAH-pollution effect.

  17. The developmental relationship between DHEA and visual attention is mediated by structural plasticity of cortico-amygdalar networks.

    Science.gov (United States)

    Nguyen, Tuong-Vi; Gower, Patricia; Albaugh, Matthew D; Botteron, Kelly N; Hudziak, James J; Fonov, Vladimir S; Collins, Louis; Ducharme, Simon; McCracken, James T

    2016-08-01

    Humans and the great apes are the only species demonstrated to exhibit adrenarche, a key developmental event leading to increased production of dehydroepiandrosterone (DHEA), suggesting that this hormone may play an important evolutionary role. Similarly, visual attention networks have been shown to evolve in a human-specific manner, with some anatomical connections and elements of cortical organization exclusive to our species. Existing studies of human brain development support the notion that DHEA shows significant uptake in cortical structures and the amygdala, and as such, could be involved in the bottom-up regulation of visual attention. Here we examined associations between DHEA, structural covariance of the amygdala with whole-brain cortical thickness, and tests of visual attention, in a longitudinal sample of typically developing children and adolescents 6-22 years of age. We found that DHEA predicted covariance between amygdalar volume and the left occipital pole, right somatosensory parietal cortex and right anterior cingulate cortex. Amygdala-occipital covariance predicted visual awareness; amygdala-parietal covariance predicted visuo-motor dexterity and processing speed; amygdala-prefrontal covariance predicted global attentional impairment. Further, effects of DHEA were above and beyond those of age and sex, as well as distinct from those of pubertal stage, estradiol and testosterone. These findings support the notion that DHEA may play a unique role in shaping amygdala-dependent cortical plasticity and in regulating 'bottom-up' visual attention processes from childhood to young adulthood. PMID:27236606

  18. A Common Structural Component for β-Subunit Mediated Modulation of Slow Inactivation in Different KV Channels

    Directory of Open Access Journals (Sweden)

    Nathalie Strutz-Seebohm

    2013-06-01

    Full Text Available Background/Aims: Potassium channels are tetrameric proteins providing potassium selective passage through lipid embedded proteinaceous pores with highest fidelity. The selectivity results from binding to discrete potassium binding sites and stabilization of a hydrated potassium ion in a central internal cavity. The four potassium binding sites, generated by the conserved TTxGYGD signature sequence are formed by the backbone carbonyls of the amino acids TXGYG. Residues KV1.5-Val481, KV4.3-Leu368 and KV7.1- Ile 313 represent the amino acids in the X position of the respective channels. Methods: Here, we study the impact of these residues on ion selectivity, permeation and inactivation kinetics as well as the modulation by β-subunits using site-specific mutagenesis, electrophysiological analyses and molecular dynamics simulations. Results: We identify this position as key in modulation of slow inactivation by structurally dissimilar β-subunits in different KV channels. Conclusion: We propose a model in which structural changes accompanying activation and β-subunit modulation allosterically constrain the backbone carbonyl oxygen atoms via the side chain of the respective X-residue in the signature sequence to reduce conductance during slow inactivation.

  19. The rhizosphere and PAH amendment mediate impacts on functional and structural bacterial diversity in sandy peat soil

    International Nuclear Information System (INIS)

    To reveal the degradation capacity of bacteria in PAH polluted soil and rhizosphere we combined bacterial extradiol ring-cleavage dioxygenase and 16S rRNA analysis in Betula pubescens rhizoremediation. Characterisation of the functional bacterial community by RFLP revealed novel environmental dioxygenases, and their putative hosts were studied by 16S rRNA amplification. Plant rhizosphere and PAH amendment effects were detected by the RFLP/T-RFLP analysis. Functional species richness increased in the birch rhizosphere and PAH amendment impacted the compositional diversity of the dioxygenases and the structural 16S rRNA community. A shift from an Acidobacteria and Verrucomicrobia dominated to an Alpha- and Betaproteobacteria dominated community structure was detected in polluted soil. Clone sequence analysis indicated catabolic significance of Burkholderia in PAH polluted soil. These results advance our understanding of rhizoremediation and unveil the extent of uncharacterized functional bacteria to benefit bioremediation by facilitating the development of the molecular tool box to monitor bacterial populations in biodegradation. - The bacterial community analysis using 16S rRNA and extradiol dioxygenase marker genes in rhizoremediation revealed both a rhizosphere and a PAH-pollution effect.

  20. Abnormal structural luteolysis in ovaries of the senescence accelerated mouse (SAM): expression of Fas ligand/Fas-mediated apoptosis signaling molecules in luteal cells.

    Science.gov (United States)

    Kiso, Minako; Manabe, Noboru; Komatsu, Kohji; Shimabe, Munetake; Miyamoto, Hajime

    2003-12-01

    Senescence accelerated mouse-prone (SAMP) mice with a shortened life span show accelerated changes in many of the signs of aging and a shorter reproductive life span than SAM-resistant (SAMR) controls. We previously showed that functional regression (progesterone dissimilation) occurs in abnormally accumulated luteal bodies (aaLBs) of SAMP mice, but structural regression of luteal cells in aaLB is inhibited. A deficiency of luteal cell apoptosis causes the abnormal accumulation of LBs in SAMP ovaries. In the present study, to show the abnormality of Fas ligand (FasL)/Fas-mediated apoptosis signal transducing factors in the aaLBs of the SAMP ovaries, we assessed the changes in the expression of FasL, Fas, caspase-8 and caspase-3 mRNAs by reverse transcription-polymerase chain reaction, and in the expression and localization of FasL, Fas and activated caspase-3 proteins by Western blotting and immunohistochemistry, respectively, during the estrus cycle/luteolysis. These mRNAs and proteins were expressed in normal LBs of both SAMP and SAMR ovaries, but not at all or only in trace amounts in aaLBs of SAMP, indicating that structural regression is inhibited by blockage of the expression of these transducing factors in luteal cells of aaLBs in SAMP mice. PMID:14967896

  1. New insight to structure-function relationship of GalNAc mediated primary interaction between insecticidal Cry1Ac toxin and HaALP receptor of Helicoverpa armigera.

    Directory of Open Access Journals (Sweden)

    Anindita Sengupta

    Full Text Available Over the last few decades Cry1Ac toxin has been widely used in controlling the insect attack due to its high specificity towards target insects. The pore-forming toxin undergoes a complex mechanism in the insect midgut involving sequential interaction with specific glycosylated receptors in which terminal GalNAc molecule plays a vital role. Recent studies on Cry toxins interactions with specific receptors revealed the importance of several amino acid residues in domain III of Cry1Ac, namely Q509, N510, R511, Y513 and W545, serve as potential binding sites that surround the putative GalNAc binding pocket and mediate the toxin-receptor interaction. In the present study, alanine substitution mutations were generated in the Cry1Ac domain III region and functional significance of those key residues was monitored by insect bioassay on Helicoverpa armigera larvae. In addition, ligand blot analysis and SPR binding assay was performed to monitor the binding characteristics of Cry1Ac wild type and mutant toxins towards HaALP receptor isolated from Helicoverpa armigera. Mutagenesis data revealed that, alanine substitutions in R511, Y513 and W545 substantially impacted the relative affinity towards HaALP receptor and toxicity toward target insect. Furthermore, in silico study of GalNAc-mediated interaction also confirmed the important roles of these residues. This structural analysis will provide a detail insight for evaluating and engineering new generation Cry toxins to address the problem of change in insect behavioral patterns.

  2. An X-ray chamber for in situ structural studies of solvent-mediated nanoparticle self-assembly

    International Nuclear Information System (INIS)

    Technical details and experimental examples are given for a novel sample environment allowing X-ray investigations of self-assembly phenomena induced by controlled bulk solvent evaporation and nanoscale solvent adsorption/desorption. Spontaneous ordering of nanoparticles (NPs) occurring as a consequence of solvent evaporation can yield highly ordered and extended NP superlattices bearing both fundamental scientific interest and potential for technological application. A versatile experimental chamber has been developed allowing (i) controlled in situ deposition of NP solutions on solid substrates, (ii) rate-controlled evaporation of the bulk solvent, and (iii) adsorption/desorption of nano-thick solvent films onto preformed NP assemblies. Within this hermetically sealed chamber all the stages of self-assembly, including macroscopic solution evaporation, NP thin-film formation and its subsequent structural transformation induced by nano-thick solvent films, can be characterized in situ by X-ray scattering techniques. Here, technical design and calibration details are provided, as well as three experimental examples highlighting the chamber’s performances and potential. Examples include the controlled adsorption of thin toluene films on flat silicon wafers, the observation of transient accumulation of gold NPs near the toluene–vapour interface, and preliminary data on the structural effects of fast macroscopic solvent evaporation followed by nanoscale solvent adsorption/desorption from a vapour phase. By combining bulk evaporation rate control, fine tuning of the thickness of adsorbed solvent films and in situ X-ray characterization capabilities, this cell enables explorations of both near-to-equilibrium and far-from-equilibrium routes to NP self-assembly

  3. An X-ray chamber for in situ structural studies of solvent-mediated nanoparticle self-assembly

    Energy Technology Data Exchange (ETDEWEB)

    Calzolari, Davide C. E.; Pontoni, Diego, E-mail: pontoni@esrf.fr [European Synchrotron Radiation Facility, Beamline ID15, 38043 Grenoble (France); Daillant, Jean [CEA, IRAMIS, LIONS, Batiment 125, CEA Saclay, F-91191 Gif-sur-Yvette Cedex (France); Reichert, Harald [European Synchrotron Radiation Facility, Beamline ID15, 38043 Grenoble (France); Max-Planck-Institut für Metallforschung, Heisenbergstrasse 3, D-70569 Stuttgart (Germany)

    2013-03-01

    Technical details and experimental examples are given for a novel sample environment allowing X-ray investigations of self-assembly phenomena induced by controlled bulk solvent evaporation and nanoscale solvent adsorption/desorption. Spontaneous ordering of nanoparticles (NPs) occurring as a consequence of solvent evaporation can yield highly ordered and extended NP superlattices bearing both fundamental scientific interest and potential for technological application. A versatile experimental chamber has been developed allowing (i) controlled in situ deposition of NP solutions on solid substrates, (ii) rate-controlled evaporation of the bulk solvent, and (iii) adsorption/desorption of nano-thick solvent films onto preformed NP assemblies. Within this hermetically sealed chamber all the stages of self-assembly, including macroscopic solution evaporation, NP thin-film formation and its subsequent structural transformation induced by nano-thick solvent films, can be characterized in situ by X-ray scattering techniques. Here, technical design and calibration details are provided, as well as three experimental examples highlighting the chamber’s performances and potential. Examples include the controlled adsorption of thin toluene films on flat silicon wafers, the observation of transient accumulation of gold NPs near the toluene–vapour interface, and preliminary data on the structural effects of fast macroscopic solvent evaporation followed by nanoscale solvent adsorption/desorption from a vapour phase. By combining bulk evaporation rate control, fine tuning of the thickness of adsorbed solvent films and in situ X-ray characterization capabilities, this cell enables explorations of both near-to-equilibrium and far-from-equilibrium routes to NP self-assembly.

  4. Gap junctions mediate large-scale Turing structures in a mean-field cortex driven by subcortical noise

    Science.gov (United States)

    Steyn-Ross, Moira L.; Steyn-Ross, D. A.; Wilson, M. T.; Sleigh, J. W.

    2007-07-01

    One of the grand puzzles in neuroscience is establishing the link between cognition and the disparate patterns of spontaneous and task-induced brain activity that can be measured clinically using a wide range of detection modalities such as scalp electrodes and imaging tomography. High-level brain function is not a single-neuron property, yet emerges as a cooperative phenomenon of multiply-interacting populations of neurons. Therefore a fruitful modeling approach is to picture the cerebral cortex as a continuum characterized by parameters that have been averaged over a small volume of cortical tissue. Such mean-field cortical models have been used to investigate gross patterns of brain behavior such as anesthesia, the cycles of natural sleep, memory and erasure in slow-wave sleep, and epilepsy. There is persuasive and accumulating evidence that direct gap-junction connections between inhibitory neurons promote synchronous oscillatory behavior both locally and across distances of some centimeters, but, to date, continuum models have ignored gap-junction connectivity. In this paper we employ simple mean-field arguments to derive an expression for D2 , the diffusive coupling strength arising from gap-junction connections between inhibitory neurons. Using recent neurophysiological measurements reported by Fukuda [J. Neurosci. 26, 3434 (2006)], we estimate an upper limit of D2≈0.6cm2 . We apply a linear stability analysis to a standard mean-field cortical model, augmented with gap-junction diffusion, and find this value for the diffusive coupling strength to be close to the critical value required to destabilize the homogeneous steady state. Computer simulations demonstrate that larger values of D2 cause the noise-driven model cortex to spontaneously crystalize into random mazelike Turing structures: centimeter-scale spatial patterns in which regions of high-firing activity are intermixed with regions of low-firing activity. These structures are consistent with the

  5. Gap junctions mediate large-scale Turing structures in a mean-field cortex driven by subcortical noise.

    Science.gov (United States)

    Steyn-Ross, Moira L; Steyn-Ross, D A; Wilson, M T; Sleigh, J W

    2007-07-01

    One of the grand puzzles in neuroscience is establishing the link between cognition and the disparate patterns of spontaneous and task-induced brain activity that can be measured clinically using a wide range of detection modalities such as scalp electrodes and imaging tomography. High-level brain function is not a single-neuron property, yet emerges as a cooperative phenomenon of multiply-interacting populations of neurons. Therefore a fruitful modeling approach is to picture the cerebral cortex as a continuum characterized by parameters that have been averaged over a small volume of cortical tissue. Such mean-field cortical models have been used to investigate gross patterns of brain behavior such as anesthesia, the cycles of natural sleep, memory and erasure in slow-wave sleep, and epilepsy. There is persuasive and accumulating evidence that direct gap-junction connections between inhibitory neurons promote synchronous oscillatory behavior both locally and across distances of some centimeters, but, to date, continuum models have ignored gap-junction connectivity. In this paper we employ simple mean-field arguments to derive an expression for D2, the diffusive coupling strength arising from gap-junction connections between inhibitory neurons. Using recent neurophysiological measurements reported by Fukuda [J. Neurosci. 26, 3434 (2006)], we estimate an upper limit of D2 approximately 0.6cm2. We apply a linear stability analysis to a standard mean-field cortical model, augmented with gap-junction diffusion, and find this value for the diffusive coupling strength to be close to the critical value required to destabilize the homogeneous steady state. Computer simulations demonstrate that larger values of D2 cause the noise-driven model cortex to spontaneously crystalize into random mazelike Turing structures: centimeter-scale spatial patterns in which regions of high-firing activity are intermixed with regions of low-firing activity. These structures are consistent

  6. Structural Incorporation of Uranium into Iron Oxides: A Competitive Secondary Sequestration Pathway Mediated by Fe(II)

    Science.gov (United States)

    Massey, M. S.; Lezama-Pacheco, J. S.; Nico, P. S.; Bargar, J.; Fendorf, S.

    2011-12-01

    Uranium retention and sequestration pathways determine the long-term fate of this important contaminant in soils and sediments. Direct, enzymatic U reduction and subsequent precipitation of UO2 is one potential sequestration pathway, but indirect U transformations can also occur as a result of reactions with microbially-generated Fe(II). Here we explored uranium retention mechanisms active during abiotic reduction of U(VI) by aqueous Fe(II), in the presence of ferrihydrite, in Ca and carbonate-bearing solutions. Ferrihydrite transformation and U reduction were studied in batch incubations containing Ca (0 and 4 mM), carbonate (3.8 mM), ferrihydrite (~180 mg/L), Fe(II) (0.3 mM), and a range of concentrations of uranyl (1 to 170 μM). Uranium retention pathways were differentiated using extended x-ray absorption fine structure (EXAFS) spectroscopy and synchrotron X-ray powder diffraction. At U concentrations >50 μM, U(VI) reduction to U(IV) and subsequent precipitation of UO2 was a dominant sequestration pathway. At lower U concentrations (1-10 μM), UO2 precipitation was not observed and incorporation into goethite, the secondary transformation product of ferrihydrite, was dominant. For groundwaters having micromolar U(VI) concentrations, U incorporation into ferrihydrite transformation products via microbially-produced Fe(II) may be an important sequestration process.

  7. Structure-activity relationship of polyphenols on inhibition of chemical mediator release from rat peritoneal exudate cells.

    Science.gov (United States)

    Yamada, K; Shoji, K; Mori, M; Ueyama, T; Matsuo, N; Oka, S; Nishiyama, K; Sugano, M

    1999-03-01

    The effect of phenolic compounds in foodstuffs on histamine and leukotriene B4 (LTB4) release from rat peritoneal exudate cells and their antioxidative activity were examined to assess their antiallergenic activities. Among them, triphenols such as pyrogallol and gallic acid inhibited histamine release from the cells, but diphenols did not. On the other hand, o- and p-diphenols such as catechol and hydroquinone with strong antioxidative activity inhibited LTB4 release as strongly as pyrogallol, but an m-derivative resorcinol with weak antioxidative activity did not. Though carboxylated compounds and their noncarboxylated counterparts were antioxidative, the former exerted a much weaker inhibitory effect on the LTB4 release than the latter. In flavonols, only myricetin with a triphenolic B ring strongly inhibited histamine release, but all flavonols strongly suppressed LTB4 release irrespective of the number of OH groups in the B ring. Among flavonoids with an o-diphenolic B ring, flavonol and flavone with a C4-carbonyl group strongly inhibited LTB4 release, whereas the activity of anthocyan without C4-carbonyl was much weaker than the above compounds. These results suggest that triphenolic structure is essential for the inhibition of histamine release. On the other hand, antioxidative activity and membrane permeability of phenolic compounds seemed to be essential for the inhibition of LTB4 release. In addition, the C4-carbonyl group seemed to be important for strongly inhibiting LTB4 release. PMID:10476914

  8. Structural Basis of Cytotoxicity Mediated by the Type III Secretion Toxin ExoU from Pseudomonas aeruginosa

    Science.gov (United States)

    Gendrin, Claire; Contreras-Martel, Carlos; Bouillot, Stéphanie; Elsen, Sylvie; Lemaire, David; Skoufias, Dimitrios A.; Huber, Philippe; Attree, Ina; Dessen, Andréa

    2012-01-01

    The type III secretion system (T3SS) is a complex macromolecular machinery employed by a number of Gram-negative pathogens to inject effectors directly into the cytoplasm of eukaryotic cells. ExoU from the opportunistic pathogen Pseudomonas aeruginosa is one of the most aggressive toxins injected by a T3SS, leading to rapid cell necrosis. Here we report the crystal structure of ExoU in complex with its chaperone, SpcU. ExoU folds into membrane-binding, bridging, and phospholipase domains. SpcU maintains the N-terminus of ExoU in an unfolded state, required for secretion. The phospholipase domain carries an embedded catalytic site whose position within ExoU does not permit direct interaction with the bilayer, which suggests that ExoU must undergo a conformational rearrangement in order to access lipids within the target membrane. The bridging domain connects catalytic domain and membrane-binding domains, the latter of which displays specificity to PI(4,5)P2. Both transfection experiments and infection of eukaryotic cells with ExoU-secreting bacteria show that ExoU ubiquitination results in its co-localization with endosomal markers. This could reflect an attempt of the infected cell to target ExoU for degradation in order to protect itself from its aggressive cytotoxic action. PMID:22496657

  9. Dityrosine, 3,4-dihydroxyphenylalanine (DOPA), and radical formation from tyrosine residues on milk proteins with globular and flexible structures as a result of riboflavin-mediated photo-oxidation

    DEFF Research Database (Denmark)

    Dalsgaard, Trine K; Nielsen, Jacob H; Brown, Bronwyn E;

    2011-01-01

    Riboflavin-mediated photo-oxidative damage to protein Tyr residues has been examined to determine whether protein structure influences competing protein oxidation pathways in single proteins and protein mixtures. EPR studies resulted in the detection of Tyr-derived o-semiquione radicals, with this...

  10. Social Structure and Genetic Distance Mediate Nestmate Recognition and Aggressiveness in the Facultative Polygynous Ant Pheidole pallidula

    Science.gov (United States)

    De Laet, Sophie; Lenoir, Alain; Passera, Luc; Aron, Serge

    2016-01-01

    In social insects, the evolutionary stability of cooperation depends on the privileged relationships between individuals of the social group, which is facilitated by the recognition of relatives. Nestmate recognition is based on genetically determined cues and/or environmentally derived chemical components present on the cuticle of individuals. Here, we studied nestmate recognition in the ant Pheidole pallidula, a species where both single-queen (monogyne) and multiple-queen (polygyne) colonies co-occur in the same population. We combined geographical, genetic and chemical analyses to disentangle the factors influencing the level of intraspecific aggressiveness. We show that encounters between workers from neighbouring colonies (i.e., nests less than 5 m away) are on average less aggressive than those between workers from more distant colonies. Aggressive behaviour is associated with the level of genetic difference: workers from monogyne colonies are more aggressive than workers from polygyne colonies, and the intensity of aggressiveness is positively associated with the genetic distance between colonies. Since the genetic distance is correlated with the spatial distance between pairs of colonies, the lower level of aggression toward neighbours may result from their higher relatedness. In contrast, the analysis of overall cuticular hydrocarbon profiles shows that aggressive behaviour is associated neither with the chemical diversity of colonies, nor with the chemical distances between them. When considering methyl-branched alkanes only, however, chemical distances differed between monogyne and polygyne colonies and were significantly associated with aggressiveness. Altogether, these results show that the social structure of colonies and the genetic distances between colonies are two major factors influencing the intensity of agonistic behaviours in the ant P. pallidula. PMID:27243627

  11. Structured Approach Therapy for Combat-Related PTSD in Returning U.S. Veterans: Complementary Mediation by Changes in Emotion Functioning.

    Science.gov (United States)

    Sautter, Frederic J; Glynn, Shirley M; Becker-Cretu, Julia J; Senturk, Damla; Armelie, Aaron P; Wielt, Dustin B

    2016-08-01

    To address the impact of combat-related posttraumatic stress disorder (PTSD) on U.S. Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) veterans, the investigators developed a 12-session manualized PTSD treatment for couples called structured approach therapy (SAT). A randomized controlled trial had shown that 29 OEF/OIF veterans with combat-related PTSD who had participated in SAT showed significantly greater reductions in PTSD compared to 28 veterans receiving a 12-session PTSD family education intervention (Sautter, Glynn, Cretu, Senturk, & Vaught, 2015). We conducted supplemental follow-up and mediation analyses, which tested the hypothesis that changes in emotion functioning play a significant role in the decreases in PTSD symptoms primarily observed in veterans who had received SAT. Veterans assigned to the SAT condition showed significantly greater decreases than those assigned to PTSD family education in emotion regulation problems (p SAT. These findings suggest that SAT may aid veterans in improving their ability to regulate trauma-related emotions. PMID:27472747

  12. Structural Relation Pattern between Deviant Personality Traits, Risk Perception and Treatment Motivation in People with Substance Dependency: The Mediating Role of Risk Perception

    Directory of Open Access Journals (Sweden)

    S Basharpoor

    2016-02-01

    Full Text Available Objective: The current study was conducted to investigate the pattern of structural relations between deviant personality traits, risk perception and treatment motivation in people with substance dependency. Method: A descriptive- correlational method was used in this study. All the drug addicts referring to Ardabil centers of addiction treatment in second half of 2014 constituted the statistical population of this study. The number of 140 individuals from this population was selected via cluster sampling and responded to stages of change readiness and treatment eagerness scale, personality deviance scale, and cognitive appraisal of risky events (CARE questionnaire. Results: The results showed that risk perception and three components of treatment motivation are negatively correlated with hostile thoughts, denigration of others, low self-confidence, dependency, submissiveness; however, risk perception was positively associated with the three components of treatment motivation. The results of regression analyses also revealed that 53% variance of recognition, 44 % variance of ambivalence, and 47 % of variance of step taking were explained by deviant personality traits. Model fitness indexed confirmed the path of deviant personality traits to treatment motivation via the mediating role of risk perception. Conclusion: The findings of this study suggest that low risk perception is one of the explanatory pathways for the relationship between deviant personality traits and treatment motivation.

  13. Nest suitability, fine-scale population structure and male-mediated dispersal of a solitary ground nesting bee in an urban landscape.

    Directory of Open Access Journals (Sweden)

    Margarita M López-Uribe

    Full Text Available Bees are the primary pollinators of flowering plants in almost all ecosystems. Worldwide declines in bee populations have raised awareness about the importance of their ecological role in maintaining ecosystem functioning. The naturally strong philopatric behavior that some bee species show can be detrimental to population viability through increased probability of inbreeding. Furthermore, bee populations found in human-altered landscapes, such as urban areas, can experience lower levels of gene flow and effective population sizes, increasing potential for inbreeding depression in wild bee populations. In this study, we investigated the fine-scale population structure of the solitary bee Colletes inaequalis in an urbanized landscape. First, we developed a predictive spatial model to detect suitable nesting habitat for this ground nesting bee and to inform our field search for nests. We genotyped 18 microsatellites in 548 female individuals collected from nest aggregations throughout the study area. Genetic relatedness estimates revealed that genetic similarity among individuals was slightly greater within nest aggregations than among randomly chosen individuals. However, genetic structure among nest aggregations was low (Nei's GST = 0.011. Reconstruction of parental genotypes revealed greater genetic relatedness among females than among males within nest aggregations, suggesting male-mediated dispersal as a potentially important mechanism of population connectivity and inbreeding avoidance. Size of nesting patch was positively correlated with effective population size, but not with other estimators of genetic diversity. We detected a positive trend between geographic distance and genetic differentiation between nest aggregations. Our landscape genetic models suggest that increased urbanization is likely associated with higher levels of inbreeding. Overall, these findings emphasize the importance of density and distribution of suitable nesting

  14. Nest suitability, fine-scale population structure and male-mediated dispersal of a solitary ground nesting bee in an urban landscape.

    Science.gov (United States)

    López-Uribe, Margarita M; Morreale, Stephen J; Santiago, Christine K; Danforth, Bryan N

    2015-01-01

    Bees are the primary pollinators of flowering plants in almost all ecosystems. Worldwide declines in bee populations have raised awareness about the importance of their ecological role in maintaining ecosystem functioning. The naturally strong philopatric behavior that some bee species show can be detrimental to population viability through increased probability of inbreeding. Furthermore, bee populations found in human-altered landscapes, such as urban areas, can experience lower levels of gene flow and effective population sizes, increasing potential for inbreeding depression in wild bee populations. In this study, we investigated the fine-scale population structure of the solitary bee Colletes inaequalis in an urbanized landscape. First, we developed a predictive spatial model to detect suitable nesting habitat for this ground nesting bee and to inform our field search for nests. We genotyped 18 microsatellites in 548 female individuals collected from nest aggregations throughout the study area. Genetic relatedness estimates revealed that genetic similarity among individuals was slightly greater within nest aggregations than among randomly chosen individuals. However, genetic structure among nest aggregations was low (Nei's GST = 0.011). Reconstruction of parental genotypes revealed greater genetic relatedness among females than among males within nest aggregations, suggesting male-mediated dispersal as a potentially important mechanism of population connectivity and inbreeding avoidance. Size of nesting patch was positively correlated with effective population size, but not with other estimators of genetic diversity. We detected a positive trend between geographic distance and genetic differentiation between nest aggregations. Our landscape genetic models suggest that increased urbanization is likely associated with higher levels of inbreeding. Overall, these findings emphasize the importance of density and distribution of suitable nesting patches for enhancing

  15. Mediatized Humanitarianism

    DEFF Research Database (Denmark)

    Vestergaard, Anne

    2014-01-01

    The article investigates the implications of mediatization for the legitimation strategies of humanitarian organizations. Based on a (full population) corpus of ~400 pages of brochure material from 1970 to 2007, the micro-textual processes involved in humanitarian organizations' efforts to...... legitimate themselves and their moral claim were examined. A time trend analysis of the prioritization of actors in the material indicates that marked shifts in legitimation loci have taken place during the past 40 years. A discourse analysis unfolds the three dominant discourses behind these shifts, namely...... legitimation by accountancy, legitimation by institutionalization, and legitimation by compensation. The analysis relates these changes to a problem of trust associated with mediatization through processes of mediation....

  16. Construction of Mediators for Heterogeneous Data Source Integration Systems

    Institute of Scientific and Technical Information of China (English)

    高明; 宋瀚涛

    2003-01-01

    To construct mediators for data integration systems that integrate structured and semi-structured data, and to facilitate the reformulation and decomposition of the query, the presented system uses the XML processing language (XPL) for the mediator. With XPL, it is easy to construct mediators for data integration based on XML, and it can accelerate the work in the mediator.

  17. Mediatized play

    DEFF Research Database (Denmark)

    Johansen, Stine Liv

    Children’s play must nowadays be understood as a mediatized field in society and culture. Media – understood in a very broad sense - holds severe explanatory power in describing and understanding the practice of play, since play happens both with, through and inspired by media of different sorts........ In this presentation the case of ‘playing soccer’ will be outlined through its different mediated manifestations, including soccer games and programs on TV, computer games, magazines, books, YouTube videos and soccer trading cards....

  18. Mediating Business

    DEFF Research Database (Denmark)

    "Mediating Business" is a study of the expansion of business journalism. Building on evidence from Denmark, Finland, Norway and Sweden, "Mediating Business" is a comparative and multidisciplinary study of one of the major transformations of the mass media and the realm of business - nationally and...... globally. The book explores the history of key innovations and innovators in the business press. It analyzes changes in the discourse of business journalism associated with the growth in business news and the development of new ways of framing business issues and events. Finally, it examines the...... organizational implications of the increased media visibility of business and, in particular, the development of corporate governance and media relations....

  19. The mediation proportion: a structural equation approach for estimating the proportion of exposure effect on outcome explained by an intermediate variable

    DEFF Research Database (Denmark)

    Ditlevsen, Susanne; Christensen, Ulla; Lynch, John;

    2005-01-01

    It is often of interest to assess how much of the effect of an exposure on a response is mediated through an intermediate variable. However, systematic approaches are lacking, other than assessment of a surrogate marker for the endpoint of a clinical trial. We review a measure of "proportion...... of several intermediate variables. Binary or categorical variables can be included directly through threshold models. We call this measure the mediation proportion, that is, the part of an exposure effect on outcome explained by a third, intermediate variable. Two examples illustrate the approach. The first...... of a social class effect on a health outcome that is mediated by psychologic variables. Both the mediator and the response are composed of several ordered categorical variables, with confounders present. Finally, we extend the example to more than one mediator....

  20. Doing statistical mediation and moderation

    CERN Document Server

    Jose, Paul E

    2013-01-01

    Written in a friendly, conversational style, this book offers a hands-on approach to statistical mediation and moderation for both beginning researchers and those familiar with modeling. Starting with a gentle review of regression-based analysis, Paul Jose covers basic mediation and moderation techniques before moving on to advanced topics in multilevel modeling, structural equation modeling, and hybrid combinations, such as moderated mediation. User-friendly features include numerous graphs and carefully worked-through examples; ""Helpful Suggestions"" about procedures and pitfalls; ""Knowled

  1. Magnetic, structural, and electronic properties of iron sulfide Fe{sub 3}S{sub 4} nanoparticles synthesized by the polyol mediated process

    Energy Technology Data Exchange (ETDEWEB)

    Lyubutin, I. S., E-mail: lyubutin@ns.crys.ras.ru; Starchikov, S. S. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Lin, Chun-Rong, E-mail: crlin@mail.stut.edu.tw; Lu, Shin-Zong; Shaikh, Muhammad Omar [Southern Taiwan University of Science and Technology, Department of Mechanical Engineering, Institute of Nanotechnology (China); Funtov, K. O.; Dmitrieva, T. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Ovchinnikov, S. G., E-mail: sgo@iph.krasn.ru; Edelman, I. S.; Ivantsov, R. [Siberian Branch of Russian Academy of Sciences, Kirensky Institute of Physics (Russian Federation)

    2013-01-15

    Iron sulfide nanoparticles Fe{sub 3}S{sub 4} with the spinel-type crystal structure were synthesized by the polyol mediated process. The particle size depends on preparation conditions and varies from 9 to 20 nm. Moessbauer data have revealed that the dominating fraction of iron ions in the 9-nm sample is in the high-spin ferric state. This implies an occurrence of the cation vacancies in nonstoichiometric greigite. The stoichiometric phase of greigite Fe{sub 3}S{sub 4} dominates in the 18-nm-size nanoparticles. Magnetic measurements have shown a ferrimagnetic behavior of all samples at temperatures between 78 and 300 K. The estimated value of magnetic moment of the stoichiometric greigite nanoparticles is about 3.5 {mu}{sub B} per Fe{sub 3}S{sub 4} unit. The Moessbauer spectra indicate a superparamagnetic behavior of small particles, and some fraction of superparamagnetic phase is observed in all samples synthesized which may be caused by the particle size distribution. The blocking temperatures of T{sub B} Almost-Equal-To 230 and 250 K are estimated for the 9 and 14 nm particles, respectively. The Moessbauer parameters indicate a great degree of covalency in the Fe-S bonds and support the fast electron Fe{sup 3+} Leftwards-Arrow-Over-Rightwards-Arrow Fe{sup 2+} exchange in the B-sites of greigite. An absence of the Verwey transition at temperatures between 90 and 295 K is established supporting a semimetal type of conductivity. The temperature and magnetic field dependences of the magnetic circular dichroism (MCD) of optical spectra were measured in Fe{sub 3}S{sub 4} for the first time. The spectra differ substantially from that of the isostructural oxide Fe{sub 3}O{sub 4}. It is supposed that the MCD spectra of greigite nanoparticles result from the collective electron excitations in a wide band with superimposed peaks of the d-d transitions in Fe ions.

  2. Sequences of a hairpin structure in the 3′-untranslated region mediate regulation of human pulmonary surfactant protein B mRNA stability

    OpenAIRE

    Huang, Helen W.; Payne, David E.; Bi, Weizhen; Pan, Su; Bruce, Shirley R.; Alcorn, Joseph L.

    2012-01-01

    The ability of pulmonary surfactant to reduce alveolar surface tension requires adequate expression of surfactant protein B (SP-B). Dexamethasone (DEX, 10−7 M) increases human SP-B mRNA stability by a mechanism that requires a 126-nt-long segment (the 7.6S region) of the 3′-untranslated region (3′-UTR). The objective of this study was to identify sequences in the 7.6S region that mediate regulation of SP-B mRNA stability. The 7.6S region was found to be sufficient for DEX-mediated stabilizati...

  3. Minimal gaugino mediation

    International Nuclear Information System (INIS)

    We propose minimal gaugino mediation as the simplest known solution to the supersymmetric flavor and CP problems. The framework predicts a very minimal structure for the soft parameters at ultrahigh energies: gaugino masses are unified and non-vanishing whereas all other soft supersymmetry breaking parameters vanish. We show that this boundary condition naturally arises from a small extra dimension and present a complete model which includes a new extra-dimensional solution to the μ problem. We briefly discuss the predicted superpartner spectrum as a function of the two parameters of the model. The commonly ignored renormalization group evolution above the GUT scale is crucial to the viability of minimal gaugino mediation but does not introduce new model dependence

  4. Minimal Gaugino Mediation

    International Nuclear Information System (INIS)

    The authors propose Minimal Gaugino Mediation as the simplest known solution to the supersymmetric flavor and CP problems. The framework predicts a very minimal structure for the soft parameters at ultra-high energies: gaugino masses are unified and non-vanishing whereas all other soft supersymmetry breaking parameters vanish. The authors show that this boundary condition naturally arises from a small extra dimension and present a complete model which includes a new extra-dimensional solution to the mu problem. The authors briefly discuss the predicted superpartner spectrum as a function of the two parameters of the model. The commonly ignored renormalization group evolution above the GUT scale is crucial to the viability of Minimal Gaugino Mediation but does not introduce new model dependence

  5. Racial and Socioeconomic Status Differences in Depressive Symptoms among Black and White Youth: An Examination of the Mediating Effects of Family Structure, Stress and Support

    Science.gov (United States)

    Miller, Byron; Taylor, John

    2012-01-01

    Stress research shows that race, socioeconomic status (SES), and family context significantly impact an adolescent's psychological well-being, yet little is known about the mediating effects of family context on racial and SES differences in depressive symptoms among Black and White youth. We investigate these associations using a sample of 875…

  6. PRACTICAL ASPECTS OF MEDIATION

    OpenAIRE

    IULIA FLOCA

    2011-01-01

    Today the Romanian state gives some advantages to those who use mediation. If the Romanian state would take further steps, mediation would work as in the countries with old tradition. The article refers to success and failure got in the two years of practice. The mediation can be seen in two aspects: The first aspect regarding the mediation itself can lead to a mediation agreement. The mediation agreement gives both winnings to the conflict parts and professional satisfactions to the mediator...

  7. The Impact of Supporting Professional Characteristics on Adaptive Performance of Organization: Testing The Mediation Role of Organizational Commitment With Structural Equation Modelling

    OpenAIRE

    Hasan Kose; Gokhan Ozer,

    2013-01-01

    Organizational commitment has been employed widely in the organizational research related to employee workplace behavior. Also it has effects on organizations as well as employees. Hence, this study aims to investigate the mediation role of organizational commitment on the effect of supporting professional characteristics on organizaitonal adaptive performance. The study was applied to 403 participants from various small and medium sized enterprises quoted to İstanbul Trade Chamber. Correlati...

  8. Micro dynamics in mediation

    OpenAIRE

    Boserup, Hans

    2014-01-01

    The author has identified a number of styles in mediation, which lead to different processes and different outcomes. Through discourse and conversation analysis he examines the micro dynamics in three of these, the postmodern styles: systemic, transformative and narrative mediation. The differences between the three mediation ideologies and practice is illustrated through role play scripts enacted in each style. Mediator and providers of mediation and trainers in mediation are encouraged to a...

  9. The Economics of First-Contract Mediation

    OpenAIRE

    Dobbelaere, Sabien; LUTTENS, Roland Iwan

    2013-01-01

    This paper provides an economic foundation for non-binding mediation to stimulate first collective bargaining agreements, as implemented in British Columbia since 1993. We show that the outcome of first-contract mediation is Pareto efficient and proves immune to the insider-outsider problem of underhiring. We also demonstrate that equilibrium wages and profits under mediation coincide with the Owen values of the corresponding cooperative game with the coalitional structure that follows from u...

  10. General Gaugino Mediation

    OpenAIRE

    Sudano, Matthew

    2010-01-01

    The spectrum of a class of gaugino mediation models with arbitrary hidden sector is considered. These models are defined by a diagonal breaking of the mediating gauge group, which places them outside the realm of General Gauge Mediation. While gauginos get masses as in ordinary gauge mediation, the scalar masses are screened.

  11. Surfactant-Mediated Growth Revisited

    International Nuclear Information System (INIS)

    The x-ray structure analysis of the oxygen-surfactant-mediated growth of Ni on Cu(001) identifies up to 0.15 monolayers of oxygen in subsurface octahedral sites. This questions the validity of the general view that surfactant oxygen floats on top of the growing Ni film. Rather, the surfactant action is ascribed to an oxygen-enriched zone extending over the two topmost layers. Surface stress measurements support this finding. Our results have important implications for the microscopic understanding of surfactant-mediated growth and the change of the magnetic anisotropy of the Ni films

  12. Structure-activity relationships of vanillic acid ester analogs in inhibitory effect of antigen-mediated degranulation in rat basophilic leukemia RBL-2H3 cells.

    Science.gov (United States)

    Ishimata, Nao; Ito, Hideyuki; Tai, Akihiro

    2016-08-01

    Methyl vanillate (1) showed strong degranulation inhibitory activity among vanillin derivatives tested. In order to find structure-activity relationships for developing anti-allergic agents with simple structures and potent activity, we synthesized several vanillic acid (VA) ester derivatives with C1-C4 and C8 alkyl chains and evaluated their degranulation inhibitory activities. The most active compound of VA ester derivatives was derivative 5 with a C4 straight alkyl chain, and derivative 5 exhibited approximately three-fold greater inhibitory activity than that of 1. Moreover, we designed 8 types of analogs based on 5, and we found that the minimum structure for potent degranulation inhibitory activity requires direct connection of the butyl ester moiety on the benzene ring and at least one hydroxyl group on the benzene ring. Butyl meta or para hydroxyl benzoate (10 or 11) has a simpler structure than that of 5 and exhibited more potent degranulation inhibitory activity than that of 5. PMID:27324979

  13. The jurisprudence of responsive mediation: An empirical examination of Chinese people's mediation in action

    OpenAIRE

    Ali, S

    2013-01-01

    Community mediation in China has a long history and finds its roots in both cultural (traditional Confucian ideologies) and functional (the avoidance of social conflicts) aims. Recently, however, owing to changes in societal values occurring alongside China’s economic open-door policy, traditional values are losing their prominent role in the mediation process. Meanwhile, reforms are being carried out to provide greater structure to community mediation in China. The combination of these chang...

  14. Lumbar Facet Joint Compressive Injury Induces Lasting Changes in Local Structure, Nociceptive Scores, and Inflammatory Mediators in a Novel Rat Model

    Directory of Open Access Journals (Sweden)

    James L. Henry

    2012-01-01

    Full Text Available Objective. To develop a novel animal model of persisting lumbar facet joint pain. Methods. Sprague Dawley rats were anaesthetized and the right lumbar (L5/L6 facet joint was exposed and compressed to ~1 mm with modified clamps applied for three minutes; sham-operated and naïve animals were used as control groups. After five days, animals were tested for hind-paw sensitivity using von Frey filaments and axial deep tissue sensitivity by algometer on assigned days up to 28 days. Animals were sacrificed at selected times for histological and biochemical analysis. Results. Histological sections revealed site-specific loss of cartilage in model animals only. Tactile hypersensitivity was observed for the ipsi- and contralateral paws lasting 28 days. The threshold at which deep tissue pressure just elicited vocalization was obtained at three lumbar levels; sensitivity at L1>L3/4>L6. Biochemical analyses revealed increases in proinflammatory cytokines, especially TNF-α, IL-1α, and IL-1β. Conclusions. These data suggest that compression of a facet joint induces a novel model of local cartilage loss accompanied by increased sensitivity to mechanical stimuli and by increases in inflammatory mediators. This new model may be useful for studies on mechanisms and treatment of lumbar facet joint pain and osteoarthritis.

  15. EVALUATION OF THE STRUCTURAL AND MOLECULAR WEIGHT CHANGES OF LIGNIN DURING THE TREATMENT OF HARDWOOD ALKALINE PEROXIDE MECHANICAL PULP WITH LACCASE AND A LACCASE-MEDIATOR-SYSTEM

    Directory of Open Access Journals (Sweden)

    Yu Liu,

    2012-07-01

    Full Text Available Alkaline Peroxide Mechanical Pulp (APMP of triploid of Populus tomentosa was modified by laccase and a Laccase-Mediator-System (LMS. The influence of the following main variables on the pulp physical properties were studied: enzyme dosage, reaction time, treatment temperature, and pH. Under the optimum conditions of laccase treatment – pH 5, temperature 50 °C, pulp consistency 4%, and a reaction time of 60 min – the optimum charge of laccase was 2u/g. It was also found that the tensile strength and tear indices of the pulps treated with laccase increased significantly. The two-stage method of enzyme-mild acidic hydrolysis was adopted to isolate lignin from the APMP pulps both before and after enzymatic treatments. The functional groups in all lignin samples were qualitatively and quantitatively analyzed with 31P-NMR spectra. The molecular weight distributions of all the lignin samples were obtained through Gel Permeation Chromatography (GPC after the lignin samples were benzoylated.

  16. Activation of Methane and Ethane as Mediated by the Triatomic Anion HNbN(-) : Electronic Structure Similarity with a Pt Atom.

    Science.gov (United States)

    Ma, Jia-Bi; Xu, Lin-Lin; Liu, Qing-Yu; He, Sheng-Gui

    2016-04-11

    Investigations of the intrinsic properties of gas-phase transition metal nitride (TMN) ions represent one approach to gain a fundamental understanding of the active sites of TMN catalysts, the activities and electronic structures of which are known to be comparable to those of noble metal catalysts. Herein, we investigate the structures and reactivities of the triatomic anions HNbN(-) by means of mass spectrometry and photoelectron imaging spectroscopy, in conjunction with density functional theory calculations. The HNbN(-) anions are capable of activating CH4 and C2 H6 through oxidative addition, exhibiting similar reactivities to free Pt atoms. The similar electronic structures of HNbN(-) and Pt, especially the active orbitals, are responsible for this resemblance. Compared to the inert NbN(-) , the coordination of the H atom in HNbN(-) is indispensable. New insights into how to replace noble metals with TMNs may be derived from this combined experimental/computational study. PMID:26954294

  17. Roles of type IV pili, flagellum-mediated motility and extracellular DNA in the formation of mature multicellular structures in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Barken, Kim B; Pamp, Sünje J; Yang, Liang;

    2008-01-01

    When grown as a biofilm in laboratory flow chambers Pseudomonas aeruginosa can develop mushroom-shaped multicellular structures consisting of distinct subpopulations in the cap and stalk portions. We have previously presented evidence that formation of the cap portion of the mushroom......-shaped structures in P. aeruginosa biofilms occurs via bacterial migration and depends on type IV pili (Mol Microbiol 50: 61-68). In the present study we examine additional factors involved in the formation of this multicellular substructure. While pilA mutants, lacking type IV pili, are deficient in mushroom cap...

  18. Nucleation-mediated synthesis and enhanced catalytic properties of Au-Pd bimetallic tripods and bipyramids with twinned structures and high-energy facets

    Science.gov (United States)

    Zhang, Lei; Chen, Qiaoli; Wang, Xue; Jiang, Zhiyuan

    2016-01-01

    The Au-Pd alloy has been proved to be an excellent catalyst in many applications, such as the electro-oxidation of formic acid, CO oxidation and oxidation of alcohols to aldehydes. However, most of the research has been focused on the shape-controlled Au-Pd alloy NCs with a single-crystal structure. Due to the existence of high-energy atoms on the twin defects, twinned structures usually will further increase their catalytic activities. It is necessary to develop a method to prepare the Au-Pd alloy with twinned structures and investigate their catalytic properties. Herein, we successfully synthesized Au-Pd alloy tripods and bipyramids with twinned structures by the cooperation of cetyltrimethyl ammonium chloride (CTAC) and cetyltrimethyl ammonium bromide (CTAB). The tripods contain one twin plane, while the bipyramids consist of a fivefold-twinned structure. In addition, the tripods and bipyramids are both exposed by high-energy facets. We proposed that the tripods and bipyramids are evolved from bipyramid seeds and fivefold twinned seeds, respectively. The as-prepared Au-Pd tripods and bipyramids performed better activity for electrocatalytic oxidation of formic acid compared to the cubic Au-Pd nanoparticles.The Au-Pd alloy has been proved to be an excellent catalyst in many applications, such as the electro-oxidation of formic acid, CO oxidation and oxidation of alcohols to aldehydes. However, most of the research has been focused on the shape-controlled Au-Pd alloy NCs with a single-crystal structure. Due to the existence of high-energy atoms on the twin defects, twinned structures usually will further increase their catalytic activities. It is necessary to develop a method to prepare the Au-Pd alloy with twinned structures and investigate their catalytic properties. Herein, we successfully synthesized Au-Pd alloy tripods and bipyramids with twinned structures by the cooperation of cetyltrimethyl ammonium chloride (CTAC) and cetyltrimethyl ammonium bromide (CTAB

  19. The structural basis of Edc3- and Scd6-mediated activation of the Dcp1:Dcp2 mRNA decapping complex

    OpenAIRE

    Fromm, Simon A; Truffault, Vincent; Kamenz, Julia; Braun, Joerg E.; Hoffmann, Niklas A.; Izaurralde, Elisa; Sprangers, Remco

    2011-01-01

    5′ mRNA caps are removed by the Dcp1:Dcp2 complex. This study provides the structural basis of the competitive interaction of two activators, Edc3 and Scd6, with Dcp2. The activators are required for full decapping activity of the complex and its localization to P-bodies.

  20. Insights into Protein Sequence and Structure-Derived Features Mediating 3D Domain Swapping Mechanism using Support Vector Machine Based Approach

    Directory of Open Access Journals (Sweden)

    Khader Shameer

    2010-06-01

    Full Text Available 3-dimensional domain swapping is a mechanism where two or more protein molecules form higher order oligomers by exchanging identical or similar subunits. Recently, this phenomenon has received much attention in the context of prions and neuro-degenerative diseases, due to its role in the functional regulation, formation of higher oligomers, protein misfolding, aggregation etc. While 3-dimensional domain swap mechanism can be detected from three-dimensional structures, it remains a formidable challenge to derive common sequence or structural patterns from proteins involved in swapping. We have developed a SVM-based classifier to predict domain swapping events using a set of features derived from sequence and structural data. The SVM classifier was trained on features derived from 150 proteins reported to be involved in 3D domain swapping and 150 proteins not known to be involved in swapped conformation or related to proteins involved in swapping phenomenon. The testing was performed using 63 proteins from the positive dataset and 63 proteins from the negative dataset. We obtained 76.33% accuracy from training and 73.81% accuracy from testing. Due to high diversity in the sequence, structure and functions of proteins involved in domain swapping, availability of such an algorithm to predict swapping events from sequence and structure-derived features will be an initial step towards identification of more putative proteins that may be involved in swapping or proteins involved in deposition disease. Further, the top features emerging in our feature selection method may be analysed further to understand their roles in the mechanism of domain swapping.

  1. Structure-functional analysis of human immunodeficiency virus type 1 (HIV-1) Vpr: role of leucine residues on Vpr-mediated transactivation and virus replication

    International Nuclear Information System (INIS)

    HIV-1 Vpr has been shown to transactivate LTR-directed expression through its interaction with several proteins of cellular origin including the glucocorticoid receptor (GR). Upon activation, steroid receptors bind to proteins containing the signature motif LxxLL, translocate into the nucleus, bind to their response element, and activate transcription. The presence of such motifs in HIV-1 Vpr has prompted us to undertake the analysis of the role of specific leucine residue(s) involved in Vpr-GR interaction, subcellular localization and its effect on Vpr-GR-mediated transactivation. The individual leucine residues present in H I, II, and III were mutated in the Vpr molecule and evaluated for their ability to interact with GR, transactivate GRE and HIV-1 LTR promoters, and their colocalization with GR. While Vpr mutants L42 and L67 showed reduced activation, substitutions at L20, L23, L26, L39, L64, and L68 exhibited a similar and slightly higher level of activation compared to Vprwt. Interestingly, a substitution at residue L22 resulted in a significantly higher GRE and HIV-1 LTR transactivation (8- to 11-fold higher) in comparison to wild type. Confocal microscopy indicated that Vpr L22A exhibited a distinct condensed nuclear localization pattern different from the nuclear/perinuclear pattern noted with Vprwt. Further, electrophoretic mobility shift assay (EMSA) revealed that the VprL22A-GR complex had higher DNA-binding activity when compared to the wild type Vpr-GR complex. These results suggest a contrasting role for the leucine residues on HIV-1 LTR-directed transactivation dependent upon their location in Vpr

  2. Shared mediated workspaces

    OpenAIRE

    Greef, Tjerk de; Gullström, Charlie; Handberg, Leif; Nefs, H.T.; Parnes, Peter

    2012-01-01

    Shared mediated spaces provide viable alternatives for meetings and interactions. The development of collaborative mediated workspaces and shared negotiation spaces will have a fundamental impact on all human practices. Previous design-led research, has identified spatial design concepts, such as mediated gaze, and spatial montage, which, if unaddressed, may be said to impose friction, and thus impact negatively on the experience of mediated presence. The current paper discusses a set of conc...

  3. Mediation and Conflict Management

    OpenAIRE

    Gerald Eisenkopf

    2009-01-01

    Mediation is a popular process to manage conflicts, but there is little systematic insight into its mechanisms. This paper discusses the results from an experiment in which a mediator can induce two conflict parties to behave cooperatively. If the mediator recommends cooperative behavior and threatens to punish deviations, she achieves the efficient solution. Similar results even obtain if the mediator is biased towards one party or has no incentive to prevent the conflict. Communication betw...

  4. Confidentiality of mediation communications

    OpenAIRE

    Koo, AKC

    2011-01-01

    Discusses the common law protection afforded to mediation negotiations by the without prejudice rule, legal professional privilege and the mediation agreement signed by all parties prior to the commencement of the mediation process. Examines the inclusion of admissions within the without prejudice rule, and the exceptions to the rule. Notes two pieces of legislation offering protection, namely the US Uniform Mediation Act 2001 and Directive 2008/52. Argues that the limited protection in the U...

  5. Bayesian Mediation Analysis

    OpenAIRE

    Yuan, Ying; MacKinnon, David P.

    2009-01-01

    This article proposes Bayesian analysis of mediation effects. Compared to conventional frequentist mediation analysis, the Bayesian approach has several advantages. First, it allows researchers to incorporate prior information into the mediation analysis, thus potentially improving the efficiency of estimates. Second, under the Bayesian mediation analysis, inference is straightforward and exact, which makes it appealing for studies with small samples. Third, the Bayesian approach is conceptua...

  6. Mediation as Signal

    OpenAIRE

    Holler, M.J.; Lindner, I.

    2004-01-01

    This paper analyzes mediation as a signal. Starting from a stylized case, a game theoretical model of one-sided incomplete information, taken from Cho and Kreps (1987), is applied to discuss strategic effects of mediation. It turns out that to reject mediation can be interpreted as a ”negative signal” while the interpretation of accepting or proposing mediation is ambiguous and does not necessarily change the prior beliefs of the uninformed party. This asymmetry suggests that, in equilibrium,...

  7. Mediators as Walrasian Auctioneers

    OpenAIRE

    Dickenson, David L.

    2004-01-01

    This article opens up mediation to systematic economic analysis by considering mediators as analogous.to the Walrasian auctioneers of exchange theory. By altering trade-off rates among bargaining issues, mediators facilitate a process leading towards Pareto efficient voluntary settlements.

  8. Hybrid Gauge Mediation

    OpenAIRE

    McGarrie, Moritz

    2011-01-01

    Inspired by four dimensional (de)constructions, we use the framework of "General gauge mediation in five dimensions" to interpolate between gaugino and ordinary gauge mediation. In particular we emphasise that an intermediate hybrid regime of mediation may be obtained in these higher dimensional models as has been obtained in the quiver gauge models.

  9. Bayesian Mediation Analysis

    Science.gov (United States)

    Yuan, Ying; MacKinnon, David P.

    2009-01-01

    In this article, we propose Bayesian analysis of mediation effects. Compared with conventional frequentist mediation analysis, the Bayesian approach has several advantages. First, it allows researchers to incorporate prior information into the mediation analysis, thus potentially improving the efficiency of estimates. Second, under the Bayesian…

  10. mediation: R Package for Causal Mediation Analysis

    Directory of Open Access Journals (Sweden)

    Dustin Tingley

    2014-09-01

    Full Text Available In this paper, we describe the R package mediation for conducting causal mediation analysis in applied empirical research. In many scientific disciplines, the goal of researchers is not only estimating causal effects of a treatment but also understanding the process in which the treatment causally affects the outcome. Causal mediation analysis is frequently used to assess potential causal mechanisms. The mediation package implements a comprehensive suite of statistical tools for conducting such an analysis. The package is organized into two distinct approaches. Using the model-based approach, researchers can estimate causal mediation effects and conduct sensitivity analysis under the standard research design. Furthermore, the design-based approach provides several analysis tools that are applicable under different experimental designs. This approach requires weaker assumptions than the model-based approach. We also implement a statistical method for dealing with multiple (causally dependent mediators, which are often encountered in practice. Finally, the package also offers a methodology for assessing causal mediation in the presence of treatment noncompliance, a common problem in randomized trials.

  11. Elastocapillary-mediated interfacial assembly

    Science.gov (United States)

    Evans, Arthur

    2015-11-01

    Particles confined to an interface are present in a large number of industrial applications and ubiquitous in cellular biophysics. Interactions mediated by the interface, such as capillary effects in the presence of surface tension, give rise to rafts and aggregates whose structure is ultimately determined by geometric characteristics of these adsorbed particles. A common strategy for assembling interfacial structures relies on exploiting these interactions by tuning particle anisotropy, either by constructing rigid particles with heterogeneous wetting properties or fabricating particles that have a naturally anisotropic shape. Less explored, however, is the scenario where the interface causes the particles to deform. In this talk I will discuss the implications for interfacial assembly using elastocapillary-mediated interactions. The competition between surface energy and elasticity can wrinkle and buckle adsorbed soft particles, leading to complicated (but programmable) aggregates.

  12. Structural Relation Pattern between Deviant Personality Traits, Risk Perception and Treatment Motivation in People with Substance Dependency: The Mediating Role of Risk Perception

    OpenAIRE

    S Basharpoor

    2016-01-01

    Objective: The current study was conducted to investigate the pattern of structural relations between deviant personality traits, risk perception and treatment motivation in people with substance dependency. Method: A descriptive- correlational method was used in this study. All the drug addicts referring to Ardabil centers of addiction treatment in second half of 2014 constituted the statistical population of this study. The number of 140 individuals from this population was selected vi...

  13. Structural and Functional Conversion of Molecular Chaperone ClpB from the Gram-Positive Halophilic Lactic Acid Bacterium Tetragenococcus halophilus Mediated by ATP and Stress▿

    OpenAIRE

    Sugimoto, Shinya; Yoshida, Hiroyuki; Mizunoe, Yoshimitsu; Tsuruno, Keigo; Nakayama, Jiro; Sonomoto, Kenji

    2006-01-01

    In this study, we report the purification, initial structural characterization, and functional analysis of the molecular chaperone ClpB from the gram-positive, halophilic lactic acid bacterium Tetragenococcus halophilus. A recombinant T. halophilus ClpB (ClpBTha) was overexpressed in Escherichia coli and purified by affinity chromatography, hydroxyapatite chromatography, and gel filtration chromatography. As demonstrated by gel filtration chromatography, chemical cross-linking with glutaralde...

  14. Ecosystem engineering in fragmented forests: Edge-mediated hyper-abundance of leaf-cutting ants and resulting impacts on forest structure, microclimate and regeneration

    OpenAIRE

    Meyer, Sebastian T.

    2008-01-01

    Fragmentation of habitats, especially of tropical rainforests, ranks globally among the most pervasive man-made disturbances of ecosystems. There is growing evidence for long-term effects of forest frag-mentation and the accompanying creation of artificial edges on ecosystem functioning and forest structure, which are altered in a way that generally transforms these forests into early successional systems. Edge-induced disruption of species interactions can be among the driving mechanisms gov...

  15. Optical and electrical properties of stacked binary InAs-GaAs quantum dot structures prepared under Surfactant-mediated growth conditions

    International Nuclear Information System (INIS)

    The structural, optical and electrical properties of a 10-layer InAs/GaAs quantum dots (QDs) system having InAs layers (2.9ML) grown under surfactant growth conditions, using only an impinging In beam, were investigated. This growth mode still resulted in the formation of quantum dots, but with dot sizes smaller and sample quality better than those for normal growth (NG) of ∼3ML InAs-GaAs QD structures. Room temperature photoluminescence measurements showed PL emission from this sample at 1200-1300 nm, i.e. reaching the telecom O-band. At low substrate growth temperatures (LT), 2500C, and under the same 'Arsenic free' growth condition an InAs/GaAs superlattice structure without the formation of QD was successfully grown with up to 2.9MLs of InAs, which was not achievable under NG conditions. Both samples showed a noticeable photocurrent when illuminated with 1.2 - 1.3 μm lasers. Thus they can be used as photoconductive materials that can be excited with wavelength longer than that used for the well-known LT-GaAs ultrafast material and close to the telecom wavelengths of 1.3 μm for Terahertz imaging or other optoelectronic applications.

  16. Crystal Structure of PKG I:cGMP Complex Reveals a cGMP-Mediated Dimeric Interface that Facilitates cGMP-Induced Activation.

    Science.gov (United States)

    Kim, Jeong Joo; Lorenz, Robin; Arold, Stefan T; Reger, Albert S; Sankaran, Banumathi; Casteel, Darren E; Herberg, Friedrich W; Kim, Choel

    2016-05-01

    Cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG) is a key regulator of smooth muscle and vascular tone and represents an important drug target for treating hypertensive diseases and erectile dysfunction. Despite its importance, its activation mechanism is not fully understood. To understand the activation mechanism, we determined a 2.5 Å crystal structure of the PKG I regulatory (R) domain bound with cGMP, which represents the activated state. Although we used a monomeric domain for crystallization, the structure reveals that two R domains form a symmetric dimer where the cGMP bound at high-affinity pockets provide critical dimeric contacts. Small-angle X-ray scattering and mutagenesis support this dimer model, suggesting that the dimer interface modulates kinase activation. Finally, structural comparison with the homologous cyclic AMP-dependent protein kinase reveals that PKG is drastically different from protein kinase A in its active conformation, suggesting a novel activation mechanism for PKG. PMID:27066748

  17. Regional and large-scale patterns in Amazon forest structure and function are mediated by variations in soil physical and chemical properties

    Directory of Open Access Journals (Sweden)

    C. A. Quesada

    2009-04-01

    Full Text Available Forest structure and dynamics have been noted to vary across the Amazon Basin in an east-west gradient in a pattern which coincides with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates.

    To test this hypothesis and assess the importance of edaphic properties in affect forest structure and dynamics, soil and plant samples were collected in a total of 59 different forest plots across the Amazon Basin. Samples were analysed for exchangeable cations, C, N, pH with various P fractions also determined. Physical properties were also examined and an index of soil physical quality developed.

    Overall, forest structure and dynamics were found to be strongly and quantitatively related to edaphic conditions. Tree turnover rates emerged to be mostly influenced by soil physical properties whereas forest growth rates were mainly related to a measure of available soil phosphorus, although also dependent on rainfall amount and distribution. On the other hand, large scale variations in forest biomass could not be explained by any of the edaphic properties measured, nor by variation in climate.

    A new hypothesis of self-maintaining forest dynamic feedback mechanisms initiated by edaphic conditions is proposed. It is further suggested that this is a major factor determining forest disturbance levels, species composition and forest productivity on a Basin wide scale.

  18. Conserved Structural Motifs at the C-Terminus of Baculovirus Protein IE0 are Important for its Functions in Transactivation and Supporting hr5-mediated DNA Replication

    Directory of Open Access Journals (Sweden)

    Neta Luria

    2012-05-01

    Full Text Available IE0 and IE1 are transactivator proteins of the most studied baculovirus, the Autographa californica multiple nucleopolyhedrovirus (AcMNPV. IE0 is a 72.6 kDa protein identical to IE1 with the exception of its 54 N-terminal amino acid residues. To gain some insight about important structural motifs of IE0, we expressed the protein and C‑terminal mutants of it under the control of the Drosophila heat shock promoter and studied the transactivation and replication functions of the transiently expressed proteins. IE0 was able to promote replication of a plasmid bearing the hr5 origin of replication of AcMNPV in transient transfections with a battery of eight plasmids expressing the AcMNPV genes dnapol, helicase, lef-1, lef-2, lef-3, p35, ie-2 and lef-7. IE0 transactivated expression of the baculovirus 39K promoter. Both functions of replication and transactivation were lost after introduction of selected mutations at the basic domain II and helix-loop-helix conserved structural motifs in the C-terminus of the protein. These IE0 mutants were unable to translocate to the cell nucleus. Our results point out the important role of some structural conserved motifs to the proper functioning of IE0.

  19. Gauge mediation in metastable vacua

    International Nuclear Information System (INIS)

    Until recently, dynamical supersymmetry breaking seemed an exceptional phenomenon, involving chiral gauge theories with a special structure. Recently it has become clear that requiring only metastable states with broken supersymmetry leads to a far broader class of theories. In this paper, we extend these constructions still further, finding new classes which, unlike earlier theories, do not have unbroken, approximate R symmetries. This allows construction of new models with low energy gauge mediation

  20. Phenomenological Implications of Deflected Mirage Mediation: Comparison with Mirage Mediation

    OpenAIRE

    Altunkaynak, Baris; Everett, Lisa L.; Kim, Ian-Woo; Nelson, Brent D.; Rao, Yongyan

    2010-01-01

    We compare the collider phenomenology of mirage mediation and deflected mirage mediation, which are two recently proposed "mixed" supersymmetry breaking scenarios motivated from string compactifications. The scenarios differ in that deflected mirage mediation includes contributions from gauge mediation in addition to the contributions from gravity mediation and anomaly mediation also present in mirage mediation. The threshold effects from gauge mediation can drastically alter the low energy s...

  1. Flavor mediation delivers natural SUSY

    Science.gov (United States)

    Craig, Nathaniel; McCullough, Matthew; Thaler, Jesse

    2012-06-01

    If supersymmetry (SUSY) solves the hierarchy problem, then naturalness considerations coupled with recent LHC bounds require non-trivial superpartner flavor structures. Such "Natural SUSY" models exhibit a large mass hierarchy between scalars of the third and first two generations as well as degeneracy (or alignment) among the first two generations. In this work, we show how this specific beyond the standard model (SM) flavor structure can be tied directly to SM flavor via "Flavor Mediation". The SM contains an anomaly-free SU(3) flavor symmetry, broken only by Yukawa couplings. By gauging this flavor symmetry in addition to SM gauge symmetries, we can mediate SUSY breaking via (Higgsed) gauge mediation. This automatically delivers a natural SUSY spectrum. Third-generation scalar masses are suppressed due to the dominant breaking of the flavor gauge symmetry in the top direction. More subtly, the first-two-generation scalars remain highly degenerate due to a custodial U(2) symmetry, where the SU(2) factor arises because SU(3) is rank two. This custodial symmetry is broken only at order ( m c /m t )2. SUSY gauge coupling unification predictions are preserved, since no new charged matter is introduced, the SM gauge structure is unaltered, and the flavor symmetry treats all matter multiplets equally. Moreover, the uniqueness of the anomaly-free SU(3) flavor group makes possible a number of concrete predictions for the superpartner spectrum.

  2. Habitat management affects soil chemistry and allochthonous organic inputs mediating microbial structure and exo-enzyme activity in Wadden Sea salt-marsh soils

    Science.gov (United States)

    Mueller, Peter; Granse, Dirk; Thi Do, Hai; Weingartner, Magdalena; Nolte, Stefanie; Hoth, Stefan; Jensen, Kai

    2016-04-01

    The Wadden Sea (WS) region is Europe's largest wetland and home to approximately 20% of its salt marsh area. Mainland salt marshes of the WS are anthropogenically influenced systems and have traditionally been used for livestock grazing in wide parts. After foundation of WS National Parks in the late 1980s and early 1990s, artificial drainage has been abandoned; however, livestock grazing is still common in many areas of the National Parks and is under ongoing discussion as a habitat-management practice. While studies so far focused on effects of livestock grazing on biodiversity, little is known about how biogeochemical processes, element cycling, and particularly carbon sequestration are affected. Here, we present data from a recent field study focusing on grazing effects on soil properties, microbial exo-enzyme activity, microbial abundance and structure. Exo-enzyme activity was studied conducting digestive enzyme assays for various enzymes involved in C- and N cycling. Microbial abundance and structure was assessed measuring specific gene abundance of fungi and bacteria using quantitative PCR. Soil compaction induced by grazing led to higher bulk density and decreases in soil redox (∆ >100 mV). Soil pH was significantly lower in grazed parts. Further, the proportion of allochthonous organic matter (marine input) was significantly smaller in grazed vs. ungrazed sites, likely caused by a higher sediment trapping capacity of the taller vegetation in the ungrazed sites. Grazing induced changes in bulk density, pH and redox resulted in reduced activity of enzymes involved in microbial C acquisition; however, there was no grazing effect on enzymes involved in N acquisition. While changes in pH, bulk density or redox did not affect microbial abundance and structure, the relative amount of marine organic matter significantly reduced the relative abundance of fungi (F:B ratio). We conclude that livestock grazing directly affects microbial exo-enzyme activity, thus

  3. Predicting P-Glycoprotein-Mediated Drug Transport Based On Support Vector Machine and Three-Dimensional Crystal Structure of P-glycoprotein

    OpenAIRE

    Bikadi, Zsolt; Hazai, Istvan; Malik, David; Jemnitz, Katalin; Veres, Zsuzsa; Hari, Peter; Ni, Zhanglin; Loo, Tip W.; Clarke, David M.; Hazai, Eszter; Mao, Qingcheng

    2011-01-01

    Human P-glycoprotein (P-gp) is an ATP-binding cassette multidrug transporter that confers resistance to a wide range of chemotherapeutic agents in cancer cells by active efflux of the drugs from cells. P-gp also plays a key role in limiting oral absorption and brain penetration and in facilitating biliary and renal elimination of structurally diverse drugs. Thus, identification of drugs or new molecular entities to be P-gp substrates is of vital importance for predicting the pharmacokinetics,...

  4. Anomalous ionic conductivity of Sc sub 2 (WO sub 4) sub 3 mediated by structural changes at high pressures and temperatures

    CERN Document Server

    Secco, R A; Imanaka, N; Adachi, G

    2002-01-01

    The ionic conductivity of Sc sub 2 (WO sub 4) sub 3 at 400 deg. C shows a normal decrease with increase in pressure up to 2.9 GPa but then increases anomalously at pressures up to 4.3 GPa. Synchrotron in situ x-ray diffraction results show that Sc sub 2 (WO sub 4) sub 3 undergoes pressure-induced amorphization at pressures coincident with the reversal in conductivity behaviour. The loss of crystal structure at high pressure may be associated with the property of negative thermal expansion in Sc sub 2 (WO sub 4) sub 3.

  5. Mitomycin-Induced Interstitial Pneumonitis in a Patient with BRCA2 Associated Metastatic Pancreatic Carcinoma

    OpenAIRE

    Muhammad Wasif Saif; Tong Dai

    2010-01-01

    Dear Sir, Interstitial lung diseases are diffuse parenchymal lung diseases, and represent a heterogeneous group of disorders including lymphocytic interstitial pneumonitis, interstitial lung diseases of unknown etiology, including sarcoidosis, idiopathic pulmonary fibrosis, and pulmonary fibrosis associated with connective tissue diseases [1]. Most of the interstitial disorders have a restrictive pattern with reductions in total lung capacity, functional residual capacity, and residua...

  6. Patient Perceptions of Telephone vs. In-Person BRCA1/BRCA2 Genetic Counseling.

    Science.gov (United States)

    Peshkin, Beth N; Kelly, Scott; Nusbaum, Rachel H; Similuk, Morgan; DeMarco, Tiffani A; Hooker, Gillian W; Valdimarsdottir, Heiddis B; Forman, Andrea D; Joines, Jessica Rispoli; Davis, Claire; McCormick, Shelley R; McKinnon, Wendy; Graves, Kristi D; Isaacs, Claudine; Garber, Judy; Wood, Marie; Jandorf, Lina; Schwartz, Marc D

    2016-06-01

    Telephone genetic counseling (TC) for hereditary breast/ovarian cancer risk has been associated with positive outcomes in high risk women. However, little is known about how patients perceive TC. As part of a randomized trial of TC versus usual care (UC; in-person genetic counseling), we compared high risk women's perceptions of: (1) overall satisfaction with genetic counseling; (2) convenience; (3) attentiveness during the session; (4) counselor effectiveness in providing support; and (5) counselor ability to recognize emotional responses during the session. Among the 554 participants (TC, N = 272; UC, N = 282), delivery mode was not associated with self-reported satisfaction. However, TC participants found counseling significantly more convenient than UC participants (OR = 4.78, 95 % CI = 3.32, 6.89) while also perceiving lower levels of support (OR = 0.56, 95 % CI = 0.40-0.80) and emotional recognition (OR = 0.53, 95 % CI = 0.37-0.76). In exploratory analyses, we found that non-Hispanic white participants reported higher counselor support in UC than in TC (69.4 % vs. 52.8 %; OR = 3.06, 95 % CI = 1.39-6.74), while minority women perceived less support in UC vs. TC (58.3 % vs. 38.7 %; OR = 0.80, 95 % CI = 0.39-1.65). We discuss potential research and practice implications of these findings which may further improve the effectiveness and utilization of TC. PMID:26455498

  7. Effects of BRCA1 and BRCA2 mutations on female fertility

    OpenAIRE

    Smith, Ken R.; Hanson, Heidi A.; Mineau, Geraldine P; Buys, Saundra S.

    2011-01-01

    Women with BRCA1/2 mutations have a significantly higher lifetime risk of developing breast or ovarian cancer. We suggest that female mutation carriers may have improved fitness owing to enhanced fertility relative to non-carriers. Here we show that women who are carriers of BRCA1/2 mutations living in natural fertility conditions have excess fertility as well as excess post-reproductive mortality in relation to controls. Individuals who tested positive for BRCA1/2 mutations who linked into m...

  8. BRCA1 and BRCA2 mutations in Iranian breast cancer patients: A systematic review

    OpenAIRE

    Hossein Neamatzadeh; Seyed Mostafa Shiryazdi; Seyed Mahdi Kalantar

    2015-01-01

    Background: BRCA1/2 genes mutation prevalence varies among ethnic groups and may be influenced by founder mutations. Understanding BRCA1/2 genes mutations is important for reducing breast cancer (BC) incidence, accurate risk assessment and counseling. This systematic review of the literature was conducted to addressing BRCA1/2 mutations in Iranian BC patients. Materials and Methods: A search for relevant articles was run on before January 2014 using MedLine, PubMed, Science Iranian Database, ...

  9. Structural and functional conversion of molecular chaperone ClpB from the gram-positive halophilic lactic acid bacterium Tetragenococcus halophilus mediated by ATP and stress.

    Science.gov (United States)

    Sugimoto, Shinya; Yoshida, Hiroyuki; Mizunoe, Yoshimitsu; Tsuruno, Keigo; Nakayama, Jiro; Sonomoto, Kenji

    2006-12-01

    In this study, we report the purification, initial structural characterization, and functional analysis of the molecular chaperone ClpB from the gram-positive, halophilic lactic acid bacterium Tetragenococcus halophilus. A recombinant T. halophilus ClpB (ClpB(Tha)) was overexpressed in Escherichia coli and purified by affinity chromatography, hydroxyapatite chromatography, and gel filtration chromatography. As demonstrated by gel filtration chromatography, chemical cross-linking with glutaraldehyde, and electron microscopy, ClpB(Tha) forms a homohexameric single-ring structure in the presence of ATP under nonstress conditions. However, under stress conditions, such as high-temperature (>45 degrees C) and high-salt concentrations (>1 M KCl), it dissociated into dimers and monomers, regardless of the presence of ATP. The hexameric ClpB(Tha) reactivated heat-aggregated proteins dependent upon the DnaK system from T. halophilus (KJE(Tha)) and ATP. Interestingly, the mixture of dimer and monomer ClpB(Tha), which was formed under stress conditions, protected substrate proteins from thermal inactivation and aggregation in a manner similar to those of general molecular chaperones. From these results, we hypothesize that ClpB(Tha) forms dimers and monomers to function as a holding chaperone under stress conditions, whereas it forms a hexamer ring to function as a disaggregating chaperone in cooperation with KJE(Tha) and ATP under poststress conditions. PMID:16997952

  10. Structural and Functional Conversion of Molecular Chaperone ClpB from the Gram-Positive Halophilic Lactic Acid Bacterium Tetragenococcus halophilus Mediated by ATP and Stress▿

    Science.gov (United States)

    Sugimoto, Shinya; Yoshida, Hiroyuki; Mizunoe, Yoshimitsu; Tsuruno, Keigo; Nakayama, Jiro; Sonomoto, Kenji

    2006-01-01

    In this study, we report the purification, initial structural characterization, and functional analysis of the molecular chaperone ClpB from the gram-positive, halophilic lactic acid bacterium Tetragenococcus halophilus. A recombinant T. halophilus ClpB (ClpBTha) was overexpressed in Escherichia coli and purified by affinity chromatography, hydroxyapatite chromatography, and gel filtration chromatography. As demonstrated by gel filtration chromatography, chemical cross-linking with glutaraldehyde, and electron microscopy, ClpBTha forms a homohexameric single-ring structure in the presence of ATP under nonstress conditions. However, under stress conditions, such as high-temperature (>45°C) and high-salt concentrations (>1 M KCl), it dissociated into dimers and monomers, regardless of the presence of ATP. The hexameric ClpBTha reactivated heat-aggregated proteins dependent upon the DnaK system from T. halophilus (KJETha) and ATP. Interestingly, the mixture of dimer and monomer ClpBTha, which was formed under stress conditions, protected substrate proteins from thermal inactivation and aggregation in a manner similar to those of general molecular chaperones. From these results, we hypothesize that ClpBTha forms dimers and monomers to function as a holding chaperone under stress conditions, whereas it forms a hexamer ring to function as a disaggregating chaperone in cooperation with KJETha and ATP under poststress conditions. PMID:16997952

  11. LncRNA Khps1 Regulates Expression of the Proto-oncogene SPHK1 via Triplex-Mediated Changes in Chromatin Structure.

    Science.gov (United States)

    Postepska-Igielska, Anna; Giwojna, Alena; Gasri-Plotnitsky, Lital; Schmitt, Nina; Dold, Annabelle; Ginsberg, Doron; Grummt, Ingrid

    2015-11-19

    Although thousands of long noncoding RNAs (lncRNAs) have been discovered, very little is known about their mode of action. Here we functionally characterize an E2F1-regulated lncRNA named Khps1, which is transcribed in antisense orientation to the proto-oncogene SPHK1. Khps1 activates SPHK1 expression by recruiting the histone acetyltransferase p300/CBP to the SPHK1 promoter, which leads to local changes of the chromatin structure that ensures E2F1 binding and enhances transcription. Mechanistically, this is achieved by direct association of Khps1 with a homopurine stretch upstream of the transcription start site of SPHK1, which forms a DNA-RNA triplex that anchors the lncRNA and associated effector proteins to the gene promoter. The results reveal an lncRNA- and E2F1-driven regulatory loop in which E2F1-dependent induction of antisense RNA leads to changes in chromatin structure, facilitating E2F1-dependent expression of SPHK1 and restriction of E2F1-induced apoptosis. PMID:26590717

  12. Ultrasound-mediated structural changes in cells revealed by FTIR spectroscopy: A contribution to the optimization of gene and drug delivery

    Science.gov (United States)

    Grimaldi, Paola; Di Giambattista, Lucia; Giordani, Serena; Udroiu, Ion; Pozzi, Deleana; Gaudenzi, Silvia; Bedini, Angelico; Giliberti, Claudia; Palomba, Raffaele; Congiu Castellano, Agostina

    2011-12-01

    Ultrasound effects on biological samples are gaining a growing interest concerning in particular, the intracellular delivery of drugs and genes in a safe and in a efficient way. Future progress in this field will require a better understanding of how ultrasound and acoustic cavitation affect the biological system properties. The morphological changes of cells due to ultrasound (US) exposure have been extensively studied, while little attention has been given to the cells structural changes. We have exposed two different cell lines to 1 MHz frequency ultrasound currently used in therapy, Jurkat T-lymphocytes and NIH-3T3 fibroblasts, both employed as models respectively in the apoptosis and in the gene therapy studies. The Fourier Transform Infrared (FTIR) Spectroscopy was used as probe to reveal the structural changes in particular molecular groups belonging to the main biological systems. The genotoxic damage of cells exposed to ultrasound was ascertained by the Cytokinesis-Block Micronucleus (CBMN) assay. The FTIR spectroscopy results, combined with multivariate statistical analysis, regarding all cellular components (lipids, proteins, nucleic acids) of the two cell lines, show that Jurkat cells are more sensitive to therapeutic ultrasound in the lipid and protein regions, whereas the NIH-3T3 cells are more sensitive in the nucleic acids region; a meaningful genotoxic effect is present in both cell lines only for long sonication times while in the Jurkat cells also a significant cytotoxic effect is revealed for long times of exposure to ultrasound.

  13. BRCA1-mediated repression of select X chromosome genes

    Directory of Open Access Journals (Sweden)

    Ropers H Hilger

    2004-09-01

    Full Text Available Abstract Recently BRCA1 has been implicated in the regulation of gene expression from the X chromosome. In this study the influence of BRCA1 on expression of X chromosome genes was investigated. Complementary DNA microarrays were used to compare the expression levels of X chromosome genes in 18 BRCA1-associated ovarian cancers to those of the 13 "BRCA1-like" and 14 "BRCA2-like" sporadic tumors (as defined by previously reported expression profiling. Significance was determined using parametric statistics with P

  14. A randomized trial comparing structured and lifestyle goals in an internet-mediated walking program for people with type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Fortlage Laurie A

    2007-11-01

    Full Text Available Abstract Background The majority of individuals with type 2 diabetes do not exercise regularly. Pedometer-based walking interventions can help; however, pedometer-based interventions targeting only total daily accumulated steps might not yield the same health benefits as physical activity programs specifying a minimum duration and intensity of physical activity bouts. Methods This pilot randomized trial compared two goal-setting strategies: 1 lifestyle goals targeting total daily accumulated step counts and 2 structured goals targeting bout steps defined as walking that lasts for 10 minutes or longer at a pace of at least 60 steps per minute. We sought to determine which goal-setting strategy was more effective at increasing bout steps. Participants were sedentary adults with type 2 diabetes. All participants: wore enhanced pedometers with embedded USB ports; uploaded detailed, time-stamped step-count data to a website called Stepping Up to Health; and received automated step-count feedback, automatically calculated goals, and tailored motivational messages throughout the six-week intervention. Only the automated goal calculations and step-count feedback differed between the two groups. The primary outcome of interest was increase in steps taken during the previously defined bouts of walking (lasting at least 10 minutes or longer at a pace of at least 60 steps per minute between baseline and end of the intervention. Results Thirty-five participants were randomized and 30 (86% completed the pilot study. Both groups significantly increased bout steps, but there was no statistically significant difference between groups. Among study completers, bout steps increased by 1921 ± 2729 steps a day. Those who received lifestyle goals were more satisfied with the intervention (p = 0.006 and wore the pedometer more often (p Conclusion In this six-week intervention, Lifestyle Goals group participants achieved increases in bout steps comparable to the

  15. Mediational effects of self-efficacy dimensions in the relationship between knowledge of dengue and dengue preventive behaviour with respect to control of dengue outbreaks: a structural equation model of a cross-sectional survey.

    Directory of Open Access Journals (Sweden)

    Affendi Isa

    Full Text Available BACKGROUND: Dengue fever is endemic in Malaysia, with frequent major outbreaks in urban areas. The major control strategy relies on health promotional campaigns aimed at encouraging people to reduce mosquito breeding sites close to people's homes. However, such campaigns have not always bee