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Sample records for somatic inactivating mutations

  1. Key tumor suppressor genes inactivated by "greater promoter" methylation and somatic mutations in head and neck cancer

    NARCIS (Netherlands)

    Guerrero-Preston, Rafael; Michailidi, Christina; Marchionni, Luigi; Pickering, Curtis R.; Frederick, Mitchell J.; Myers, Jeffrey N.; Yegnasubramanian, Srinivasan; Hadar, Tal; Noordhuis, Maartje G.; Zizkova, Veronika; Fertig, Elana; Agrawal, Nishant; Westra, William; Koch, Wayne; Califano, Joseph; Velculescu, Victor E.; Sidransky, David

    Tumor suppressor genes (TSGs) are commonly inactivated by somatic mutation and/or promoter methylation; yet, recent high-throughput genomic studies have not identified key TSGs inactivated by both mechanisms. We pursued an integrated molecular analysis based on methylation binding domain sequencing

  2. Somatic INK4a-ARF locus mutations: a significant mechanism of gene inactivation in squamous cell carcinomas of the head and neck.

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    Poi, M J; Yen, T; Li, J; Song, H; Lang, J C; Schuller, D E; Pearl, D K; Casto, B C; Tsai, M D; Weghorst, C M

    2001-01-01

    The INK4a-ARF locus is located on human chromosome 9p21 and is known to encode two functionally distinct tumor-suppressor genes. The p16(INK4a) (p16) tumor-suppressor gene product is a negative regulator of cyclin-dependent kinases 4 and 6, which in turn positively regulate progression of mammalian cells through the cell cycle. The p14(ARF) tumor-suppressor gene product specifically interacts with human double minute 2, leading to the subsequent stabilization of p53 and G(1) arrest. Previous investigations analyzing the p16 gene in squamous cell carcinomas of the head and neck (SCCHNs) have suggested the predominate inactivating events to be homozygous gene deletions and hypermethylation of the p16 promoter. Somatic mutational inactivation of p16 has been reported to be low (0-10%, with a combined incidence of 25 of 279, or 9%) and to play only a minor role in the development of SCCHN. The present study examined whether this particular mechanism of INK4a/ARF inactivation, specifically somatic mutation, has been underestimated in SCCHN by determining the mutational status of the p16 and p14(ARF) genes in 100 primary SCCHNs with the use of polymerase chain reaction technology and a highly sensitive, nonradioactive modification of single-stranded conformational polymorphism (SSCP) analysis termed "cold" SSCP. Exons 1alpha, 1beta, and 2 of INK4a/ARF were amplified using intron-based primers or a combination of intron- and exon-based primers. A total of 27 SCCHNs (27%) exhibited sequence alterations in this locus, 22 (22%) of which were somatic sequence alterations and five (5%) of which were a single polymorphism in codon 148. Of the 22 somatic alterations, 20 (91%) directly or indirectly involved exon 2, and two (9%) were located within exon 1alpha. No mutations were found in exon 1beta. All 22 somatic mutations would be expected to yield altered p16 proteins, but only 15 of them should affect p14(ARF) proteins. Specific somatic alterations included microdeletions or

  3. Somatic mutations of the histone H3K27 demethylase, UTX, in human cancer

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    van Haaften, Gijs; Dalgliesh, Gillian L; Davies, Helen; Chen, Lina; Bignell, Graham; Greenman, Chris; Edkins, Sarah; Hardy, Claire; O’Meara, Sarah; Teague, Jon; Butler, Adam; Hinton, Jonathan; Latimer, Calli; Andrews, Jenny; Barthorpe, Syd; Beare, Dave; Buck, Gemma; Campbell, Peter J; Cole, Jennifer; Dunmore, Rebecca; Forbes, Simon; Jia, Mingming; Jones, David; Kok, Chai Yin; Leroy, Catherine; Lin, Meng-Lay; McBride, David J; Maddison, Mark; Maquire, Simon; McLay, Kirsten; Menzies, Andrew; Mironenko, Tatiana; Lee, Mulderrig; Mudie, Laura; Pleasance, Erin; Shepherd, Rebecca; Smith, Raffaella; Stebbings, Lucy; Stephens, Philip; Tang, Gurpreet; Tarpey, Patrick S; Turner, Rachel; Turrell, Kelly; Varian, Jennifer; West, Sofie; Widaa, Sara; Wray, Paul; Collins, V Peter; Ichimura, Koichi; Law, Simon; Wong, John; Yuen, Siu Tsan; Leung, Suet Yi; Tonon, Giovanni; DePinho, Ronald A; Tai, Yu-Tzu; Anderson, Kenneth C; Kahnoski, Richard J.; Massie, Aaron; Khoo, Sok Kean; Teh, Bin Tean; Stratton, Michael R; Futreal, P Andrew

    2010-01-01

    Somatically acquired epigenetic changes are present in many cancers. Epigenetic regulation is maintained via post-translational modifications of core histones. Here, we describe inactivating somatic mutations in the histone lysine demethylase, UTX, pointing to histone H3 lysine methylation deregulation in multiple tumour types. UTX reintroduction into cancer cells with inactivating UTX mutations resulted in slowing of proliferation and marked transcriptional changes. These data identify UTX as a new human cancer gene. PMID:19330029

  4. POLE somatic mutations in advanced colorectal cancer.

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    Guerra, Joana; Pinto, Carla; Pinto, Diana; Pinheiro, Manuela; Silva, Romina; Peixoto, Ana; Rocha, Patrícia; Veiga, Isabel; Santos, Catarina; Santos, Rui; Cabreira, Verónica; Lopes, Paula; Henrique, Rui; Teixeira, Manuel R

    2017-12-01

    Despite all the knowledge already gathered, the picture of somatic genetic changes in colorectal tumorigenesis is far from complete. Recently, germline and somatic mutations in the exonuclease domain of polymerase epsilon, catalytic subunit (POLE) gene have been reported in a small subset of microsatellite-stable and hypermutated colorectal carcinomas (CRCs), affecting the proofreading activity of the enzyme and leading to misincorporation of bases during DNA replication. To evaluate the role of POLE mutations in colorectal carcinogenesis, namely in advanced CRC, we searched for somatic mutations by Sanger sequencing in tumor DNA samples from 307 cases. Microsatellite instability and mutation analyses of a panel of oncogenes were performed in the tumors harboring POLE mutations. Three heterozygous mutations were found in two tumors, the c.857C>G, p.Pro286Arg, the c.901G>A, p.Asp301Asn, and the c.1376C>T, p.Ser459Phe. Of the POLE-mutated CRCs, one tumor was microsatellite-stable and the other had low microsatellite instability, whereas KRAS and PIK3CA mutations were found in one tumor each. We conclude that POLE somatic mutations exist but are rare in advanced CRC, with further larger studies being necessary to evaluate its biological and clinical implications. © 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  5. Direct Transcriptional Consequences of Somatic Mutation in Breast Cancer

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    Adam Shlien

    2016-08-01

    Full Text Available Disordered transcriptomes of cancer encompass direct effects of somatic mutation on transcription, coordinated secondary pathway alterations, and increased transcriptional noise. To catalog the rules governing how somatic mutation exerts direct transcriptional effects, we developed an exhaustive pipeline for analyzing RNA sequencing data, which we integrated with whole genomes from 23 breast cancers. Using X-inactivation analyses, we found that cancer cells are more transcriptionally active than intermixed stromal cells. This is especially true in estrogen receptor (ER-negative tumors. Overall, 59% of substitutions were expressed. Nonsense mutations showed lower expression levels than expected, with patterns characteristic of nonsense-mediated decay. 14% of 4,234 rearrangements caused transcriptional abnormalities, including exon skips, exon reusage, fusions, and premature polyadenylation. We found productive, stable transcription from sense-to-antisense gene fusions and gene-to-intergenic rearrangements, suggesting that these mutation classes drive more transcriptional disruption than previously suspected. Systematic integration of transcriptome with genome data reveals the rules by which transcriptional machinery interprets somatic mutation.

  6. Mutation, somatic mutation and diseases of man

    International Nuclear Information System (INIS)

    Burnet, F.M.

    1976-01-01

    The relevance of the intrinsic mutagenesis for the evolution process, genetic diseases and the process of aging is exemplified. The fundamental reaction is the function of the DNA and the DNA-enzymes like the DNA-polymerases in replication, repair, and transcription. These defects are responsible for the mutation frequency and the genetic drift in the evolution process. They cause genetic diseases like Xeroderma pigmentosum which is described here in detail. The accumulation of structural and functional mistakes leads to diseases of old age, for example to autoimmune diseases and immune suppression. There is a proportionality between the duration of life and the frequency of mistakes in the enzymatic repair system. No possibility of prophylaxis or therapy is seen. Methods for prognosis could be developed. (AJ) [de

  7. Germinal and somatic mutations in cancer

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    Knudson, A.G. Jr.

    1977-01-01

    The role of germinal and somatic mutations in carcinogenesis leads to the conclusion that environmental carcinogens probably exert their effects via somatic mutations. Susceptibility to this process may itself be genetically determined, so we may deduce that two groups, one genetic and one non-genetic, are included in the 'environmental' class. Other individuals seem to acquire cancer even in the absence of such environmental agents, and these too may be classified into a genetic and a non-genetic group. It has been estimated that in industrial countries, the environmental groups include 70-80% of all cancer cases, but we are only beginning to know how to separate the genetic and non-genetic subgroups. The genetic subgroup of the 'non-environmental' group is very small, probably of the order of magnitude of 1-2% for cancer as a whole. The remainder, about 25%, comprises a non-genetic, non-environmental subgroup that seems to arise as a consequence of 'spontaneous' somatic mutations. The incidence of these 'background' cancers is what we should combat with preventive and therapeutic measures

  8. Gamma ray induced somatic mutations in rose

    International Nuclear Information System (INIS)

    Datta, S.K.

    1989-01-01

    Budwood of 32 rose cultivars (Rosa spp.) was exposed to 3-4 krad of gamma rays and eyes were grafted on Rosa indica var. odorata root stock. Radiosensitivity with respect to sprouting, survival and plant height, and mutation frequency varied with the cultivar and dose of gamma rays. Somatic mutations in flower colour/shape were detected as chimera in 21 cultivars. The size of the mutant sector varied from a narrow streak on a petal to a whole flower and from a portion of a branch to an entire branch. 14 mutants were detected in M 1 V 1 , four in M 1 V 2 and three in M 1 V 3 . Maximum number of mutations was detected following 3 krad treatment. Eyes from mutant branches were grafted again on root stock and non-chimeric mutants were aimed at by vegetative propagation. Mutants from 11 cultivars only could be isolated in pure form. Isolation of non-chimeric mutants sometimes is difficult due to weak growth of a mutant branch. In such a case, all normal looking branches are removed to force a better growth of the mutant branch. It is advisable to maintain irradiated plants at least for four years with drastic pruning in each year. Nine mutants viz. 'Sharada', 'Sukumari', 'Tangerine Contempo', 'Yellow Contempo', 'Pink Contempo', 'Striped Contempo', 'Twinkle', 'Curio' and 'Light Pink Prize' have already been released as new cultivars for commercialization [ref. MBNL No. 23 and 31] and others are being multiplied and assessed. The mutation spectrum appears to be wider for the cultivars 'Contempo' and 'Imperator'. Pigment composition of the original variety is relevant for the kind of flower colour mutations that can be induced

  9. Progression inference for somatic mutations in cancer

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    Leif E. Peterson

    2017-04-01

    Full Text Available Computational methods were employed to determine progression inference of genomic alterations in commonly occurring cancers. Using cross-sectional TCGA data, we computed evolutionary trajectories involving selectivity relationships among pairs of gene-specific genomic alterations such as somatic mutations, deletions, amplifications, downregulation, and upregulation among the top 20 driver genes associated with each cancer. Results indicate that the majority of hierarchies involved TP53, PIK3CA, ERBB2, APC, KRAS, EGFR, IDH1, VHL, etc. Research into the order and accumulation of genomic alterations among cancer driver genes will ever-increase as the costs of nextgen sequencing subside, and personalized/precision medicine incorporates whole-genome scans into the diagnosis and treatment of cancer. Keywords: Oncology, Cancer research, Genetics, Computational biology

  10. Somatic mutations in the transcriptional corepressor gene BCORL1 in adult acute myelogenous leukemia.

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    Li, Meng; Collins, Roxane; Jiao, Yuchen; Ouillette, Peter; Bixby, Dale; Erba, Harry; Vogelstein, Bert; Kinzler, Kenneth W; Papadopoulos, Nickolas; Malek, Sami N

    2011-11-24

    To further our understanding of the genetic basis of acute myelogenous leukemia (AML), we determined the coding exon sequences of ∼ 18 000 protein-encoding genes in 8 patients with secondary AML. Here we report the discovery of novel somatic mutations in the transcriptional corepressor gene BCORL1 that is located on the X-chromosome. Analysis of BCORL1 in an unselected cohort of 173 AML patients identified a total of 10 mutated cases (6%) with BCORL1 mutations, whereas analysis of 19 AML cell lines uncovered 4 (21%) BCORL1 mutated cell lines. The majority (87%) of the mutations in BCORL1 were predicted to inactivate the gene product as a result of nonsense mutations, splice site mutation, or out-of-frame insertions or deletions. These results indicate that BCORL1 by genetic criteria is a novel candidate tumor suppressor gene, joining the growing list of genes recurrently mutated in AML.

  11. Induction and isolation of somatic mutations in vegetatively propagated plants

    International Nuclear Information System (INIS)

    Donini, B.

    1975-01-01

    Research carried out since 1963 concentrated on techniques of mutagenic treatment: problems of exposure, type of radiation (acute irradiation by x- and γ-rays, and chronic exposure in the gamma field), conditions during and after irradiation, mechanisms of mutation induction, and methodology of isolation of somatic mutations. Analyses of somatic mutations included studies on apple, pear, olive, peach, grape and cherry plants. Young trees, dormant and rooted scions, summer and floral buds or seeds were used

  12. Somatic mutations in histiocytic sarcoma identified by next generation sequencing.

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    Liu, Qingqing; Tomaszewicz, Keith; Hutchinson, Lloyd; Hornick, Jason L; Woda, Bruce; Yu, Hongbo

    2016-08-01

    Histiocytic sarcoma is a rare malignant neoplasm of presumed hematopoietic origin showing morphologic and immunophenotypic evidence of histiocytic differentiation. Somatic mutation importance in the pathogenesis or disease progression of histiocytic sarcoma was largely unknown. To identify somatic mutations in histiocytic sarcoma, we studied 5 histiocytic sarcomas [3 female and 2 male patients; mean age 54.8 (20-72), anatomic sites include lymph node, uterus, and pleura] and matched normal tissues from each patient as germ line controls. Somatic mutations in 50 "Hotspot" oncogenes and tumor suppressor genes were examined using next generation sequencing. Three (out of five) histiocytic sarcoma cases carried somatic mutations in BRAF. Among them, G464V [variant frequency (VF) of 43.6 %] and G466R (VF of 29.6 %) located at the P loop potentially interfere with the hydrophobic interaction between P and activating loops and ultimately activation of BRAF. Also detected was BRAF somatic mutation N581S (VF of 7.4 %), which was located at the catalytic loop of BRAF kinase domain: its role in modifying kinase activity was unclear. A similar mutational analysis was also performed on nine acute monocytic/monoblastic leukemia cases, which did not identify any BRAF somatic mutations. Our study detected several BRAF mutations in histiocytic sarcomas, which may be important in understanding the tumorigenesis of this rare neoplasm and providing mechanisms for potential therapeutical opportunities.

  13. Somatic point mutation calling in low cellularity tumors.

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    Karin S Kassahn

    Full Text Available Somatic mutation calling from next-generation sequencing data remains a challenge due to the difficulties of distinguishing true somatic events from artifacts arising from PCR, sequencing errors or mis-mapping. Tumor cellularity or purity, sub-clonality and copy number changes also confound the identification of true somatic events against a background of germline variants. We have developed a heuristic strategy and software (http://www.qcmg.org/bioinformatics/qsnp/ for somatic mutation calling in samples with low tumor content and we show the superior sensitivity and precision of our approach using a previously sequenced cell line, a series of tumor/normal admixtures, and 3,253 putative somatic SNVs verified on an orthogonal platform.

  14. RADIA: RNA and DNA integrated analysis for somatic mutation detection.

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    Amie J Radenbaugh

    Full Text Available The detection of somatic single nucleotide variants is a crucial component to the characterization of the cancer genome. Mutation calling algorithms thus far have focused on comparing the normal and tumor genomes from the same individual. In recent years, it has become routine for projects like The Cancer Genome Atlas (TCGA to also sequence the tumor RNA. Here we present RADIA (RNA and DNA Integrated Analysis, a novel computational method combining the patient-matched normal and tumor DNA with the tumor RNA to detect somatic mutations. The inclusion of the RNA increases the power to detect somatic mutations, especially at low DNA allelic frequencies. By integrating an individual's DNA and RNA, we are able to detect mutations that would otherwise be missed by traditional algorithms that examine only the DNA. We demonstrate high sensitivity (84% and very high precision (98% and 99% for RADIA in patient data from endometrial carcinoma and lung adenocarcinoma from TCGA. Mutations with both high DNA and RNA read support have the highest validation rate of over 99%. We also introduce a simulation package that spikes in artificial mutations to patient data, rather than simulating sequencing data from a reference genome. We evaluate sensitivity on the simulation data and demonstrate our ability to rescue back mutations at low DNA allelic frequencies by including the RNA. Finally, we highlight mutations in important cancer genes that were rescued due to the incorporation of the RNA.

  15. The somatic mutation landscape of premalignant colorectal adenoma.

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    Lin, Shu-Hong; Raju, Gottumukkala S; Huff, Chad; Ye, Yuanqing; Gu, Jian; Chen, Jiun-Sheng; Hildebrandt, Michelle A T; Liang, Han; Menter, David G; Morris, Jeffery; Hawk, Ernest; Stroehlein, John R; Futreal, Andrew; Kopetz, Scott; Mishra, Lopa; Wu, Xifeng

    2017-06-12

    There are few studies which characterised the molecular alterations in premalignant colorectal adenomas. Our major goal was to establish colorectal adenoma genome atlas and identify molecular markers of progression from colorectal adenoma to adenocarcinoma. Whole-exome sequencing and targeted sequencing were carried out in 149 adenoma samples and paired blood from patients with conventional adenoma or sessile serrated adenoma to characterise the somatic mutation landscape for premalignant colorectal lesions. The identified somatic mutations were compared with those in colorectal cancer (CRC) samples from The Cancer Genome Atlas. A supervised random forest model was employed to identify gene panels differentiating adenoma from CRC. Similar somatic mutation frequencies, but distinctive driver mutations, were observed in sessile serrated adenomas and conventional adenomas. The final model included 20 genes and was able to separate the somatic mutation profile of colorectal adenoma and adenocarcinoma with an area under the curve of 0.941. The findings of this project hold potential to better identify patients with adenoma who may be candidates for targeted surveillance programmes and preventive interventions to reduce the incidence of CRC. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  16. The Landscape of Somatic Genetic Alterations in Breast Cancers From ATM Germline Mutation Carriers.

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    Weigelt, Britta; Bi, Rui; Kumar, Rahul; Blecua, Pedro; Mandelker, Diana L; Geyer, Felipe C; Pareja, Fresia; James, Paul A; Couch, Fergus J; Eccles, Diana M; Blows, Fiona; Pharoah, Paul; Li, Anqi; Selenica, Pier; Lim, Raymond S; Jayakumaran, Gowtham; Waddell, Nic; Shen, Ronglai; Norton, Larry; Wen, Hannah Y; Powell, Simon N; Riaz, Nadeem; Robson, Mark E; Reis-Filho, Jorge S; Chenevix-Trench, Georgia

    2018-02-28

    Pathogenic germline variants in ataxia-telangiectasia mutated (ATM), a gene that plays a role in DNA damage response and cell cycle checkpoints, confer an increased breast cancer (BC) risk. Here, we investigated the phenotypic characteristics and landscape of somatic genetic alterations in 24 BCs from ATM germline mutation carriers by whole-exome and targeted sequencing. ATM-associated BCs were consistently hormone receptor positive and largely displayed minimal immune infiltrate. Although 79.2% of these tumors exhibited loss of heterozygosity of the ATM wild-type allele, none displayed high activity of mutational signature 3 associated with defective homologous recombination DNA (HRD) repair. No TP53 mutations were found in the ATM-associated BCs. Analysis of an independent data set confirmed that germline ATM variants and TP53 somatic mutations are mutually exclusive. Our findings indicate that ATM-associated BCs often harbor bi-allelic inactivation of ATM, are phenotypically distinct from BRCA1/2-associated BCs, lack HRD-related mutational signatures, and that TP53 and ATM genetic alterations are likely epistatic.

  17. Somatic mutations affect key pathways in lung adenocarcinoma

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    Ding, Li; Getz, Gad; Wheeler, David A.; Mardis, Elaine R.; McLellan, Michael D.; Cibulskis, Kristian; Sougnez, Carrie; Greulich, Heidi; Muzny, Donna M.; Morgan, Margaret B.; Fulton, Lucinda; Fulton, Robert S.; Zhang, Qunyuan; Wendl, Michael C.; Lawrence, Michael S.; Larson, David E.; Chen, Ken; Dooling, David J.; Sabo, Aniko; Hawes, Alicia C.; Shen, Hua; Jhangiani, Shalini N.; Lewis, Lora R.; Hall, Otis; Zhu, Yiming; Mathew, Tittu; Ren, Yanru; Yao, Jiqiang; Scherer, Steven E.; Clerc, Kerstin; Metcalf, Ginger A.; Ng, Brian; Milosavljevic, Aleksandar; Gonzalez-Garay, Manuel L.; Osborne, John R.; Meyer, Rick; Shi, Xiaoqi; Tang, Yuzhu; Koboldt, Daniel C.; Lin, Ling; Abbott, Rachel; Miner, Tracie L.; Pohl, Craig; Fewell, Ginger; Haipek, Carrie; Schmidt, Heather; Dunford-Shore, Brian H.; Kraja, Aldi; Crosby, Seth D.; Sawyer, Christopher S.; Vickery, Tammi; Sander, Sacha; Robinson, Jody; Winckler, Wendy; Baldwin, Jennifer; Chirieac, Lucian R.; Dutt, Amit; Fennell, Tim; Hanna, Megan; Johnson, Bruce E.; Onofrio, Robert C.; Thomas, Roman K.; Tonon, Giovanni; Weir, Barbara A.; Zhao, Xiaojun; Ziaugra, Liuda; Zody, Michael C.; Giordano, Thomas; Orringer, Mark B.; Roth, Jack A.; Spitz, Margaret R.; Wistuba, Ignacio I.; Ozenberger, Bradley; Good, Peter J.; Chang, Andrew C.; Beer, David G.; Watson, Mark A.; Ladanyi, Marc; Broderick, Stephen; Yoshizawa, Akihiko; Travis, William D.; Pao, William; Province, Michael A.; Weinstock, George M.; Varmus, Harold E.; Gabriel, Stacey B.; Lander, Eric S.; Gibbs, Richard A.; Meyerson, Matthew; Wilson, Richard K.

    2009-01-01

    Determining the genetic basis of cancer requires comprehensive analyses of large collections of histopathologically well-classified primary tumours. Here we report the results of a collaborative study to discover somatic mutations in 188 human lung adenocarcinomas. DNA sequencing of 623 genes with known or potential relationships to cancer revealed more than 1,000 somatic mutations across the samples. Our analysis identified 26 genes that are mutated at significantly high frequencies and thus are probably involved in carcinogenesis. The frequently mutated genes include tyrosine kinases, among them the EGFR homologue ERBB4; multiple ephrin receptor genes, notably EPHA3; vascular endothelial growth factor receptor KDR; and NTRK genes. These data provide evidence of somatic mutations in primary lung adenocarcinoma for several tumour suppressor genes involved in other cancers—including NF1, APC, RB1 and ATM—and for sequence changes in PTPRD as well as the frequently deleted gene LRP1B. The observed mutational profiles correlate with clinical features, smoking status and DNA repair defects. These results are reinforced by data integration including single nucleotide polymorphism array and gene expression array. Our findings shed further light on several important signalling pathways involved in lung adenocarcinoma, and suggest new molecular targets for treatment. PMID:18948947

  18. Somatic CALR mutations in myeloproliferative neoplasms with nonmutated JAK2

    NARCIS (Netherlands)

    Nangalia, J.; Massie, C.E.; Baxter, E.J.; Nice, F.L.; Gundem, G.; Wedge, D.C.; Avezov, E.; Li, J.; Kollmann, K.; Kent, D.G.; Aziz, A.; Godfrey, A.L.; Hinton, J.; Martincorena, I.; Loo, P. Van; Jones, A.V.; Guglielmelli, P.; Tarpey, P.; Harding, H.P.; Fitzpatrick, J.D.; Goudie, C.T.; Ortmann, C.A.; Loughran, S.J.; Raine, K.; Jones, D.R.; Butler, A.P.; Teague, J.W.; O'Meara, S.; McLaren, S.; Bianchi, M.; Silber, Y.; Dimitropoulou, D.; Bloxham, D.; Mudie, L.; Maddison, M.; Robinson, B.; Keohane, C.; Maclean, C.; Hill, K.; Orchard, K.; Tauro, S.; Du, M.Q.; Greaves, M.; Bowen, D.; Huntly, B.J.; Harrison, C.N.; Cross, N.C.; Ron, D.; Vannucchi, A.M.; Papaemmanuil, E.; Campbell, P.J.; Green, A.R.

    2013-01-01

    BACKGROUND: Somatic mutations in the Janus kinase 2 gene (JAK2) occur in many myeloproliferative neoplasms, but the molecular pathogenesis of myeloproliferative neoplasms with nonmutated JAK2 is obscure, and the diagnosis of these neoplasms remains a challenge. METHODS: We performed exome sequencing

  19. Somatic activating ARAF mutations in Langerhans cell histiocytosis

    NARCIS (Netherlands)

    Nelson, David S.; Quispel, Willemijn; Badalian-Very, Gayane; van Halteren, Astrid G. S.; van den Bos, Cor; Bovée, Judith V. M. G.; Tian, Sara Y.; van Hummelen, Paul; Ducar, Matthew; MacConaill, Laura E.; Egeler, R. Maarten; Rollins, Barrett J.

    2014-01-01

    The extracellular signal-regulated kinase (ERK) signaling pathway is activated in Langerhans cell histiocytosis (LCH) histiocytes, but only 60% of cases carry somatic activating mutations of BRAF. To identify other genetic causes of ERK pathway activation, we performed whole exome sequencing on

  20. In vivo somatic mutation systems in the mouse

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    Russell, L.B.

    1979-01-01

    In an effort to meet the need for a fast and cheap in vivo prescreen for inherited mammalian point mutations, a somatic forward-mutation method, originally developed in an x-ray experiment, has more recently been tested in work with chemical mutagens. The method makes use of coat-color mutations because the gene product is usually locally expressed, mosaics can be detected with minimal effort, and opportunities for making comparison with induction of germinal point mutations are greatest.--Following treatment of embryos that are heterozygous at specific coat-color loci, various induced genetic changes can result in expression of the recessive (RS) in clones derived from mutant melanocyte precursor cells. However, other events, such as decrease in the number of precursor cells, or disturbed differentiation, can also result in spots, which with careful classification can usually be distinguished from RS's on the basis of their location and color. When this is done, the relative RS frequencies for a series of compounds at least roughly parallel the relative spermatogonial mutation rates. The fact that easily measurable (though low) RS rates are obtained with compounds that have yielded negative results in spermatogonial tests is not surprising in view of the fact that RS's can be caused by several mechanisms besides point mutation.--In spite of the parallelism observed in one laboratory, the usefulness of the in vivo somatic mutation method as a prescreen could come to be doubted because of major discrepancies between results of similar experiments at different laboratories. However, It appears probable that at least some of these discrepancies are due to failure to discriminate between spots that probably resulted from melanocyte insufficiency and spots that resulted from expression of the recessive.--Reverse somatic mutation systems can potentially avoid some of the pitfalls of forward mutation systems. Such system are still in developmental stages

  1. Somatic Mutations and Clonal Hematopoiesis in Aplastic Anemia.

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    Yoshizato, Tetsuichi; Dumitriu, Bogdan; Hosokawa, Kohei; Makishima, Hideki; Yoshida, Kenichi; Townsley, Danielle; Sato-Otsubo, Aiko; Sato, Yusuke; Liu, Delong; Suzuki, Hiromichi; Wu, Colin O; Shiraishi, Yuichi; Clemente, Michael J; Kataoka, Keisuke; Shiozawa, Yusuke; Okuno, Yusuke; Chiba, Kenichi; Tanaka, Hiroko; Nagata, Yasunobu; Katagiri, Takamasa; Kon, Ayana; Sanada, Masashi; Scheinberg, Phillip; Miyano, Satoru; Maciejewski, Jaroslaw P; Nakao, Shinji; Young, Neal S; Ogawa, Seishi

    2015-07-02

    In patients with acquired aplastic anemia, destruction of hematopoietic cells by the immune system leads to pancytopenia. Patients have a response to immunosuppressive therapy, but myelodysplastic syndromes and acute myeloid leukemia develop in about 15% of the patients, usually many months to years after the diagnosis of aplastic anemia. We performed next-generation sequencing and array-based karyotyping using 668 blood samples obtained from 439 patients with aplastic anemia. We analyzed serial samples obtained from 82 patients. Somatic mutations in myeloid cancer candidate genes were present in one third of the patients, in a limited number of genes and at low initial variant allele frequency. Clonal hematopoiesis was detected in 47% of the patients, most frequently as acquired mutations. The prevalence of the mutations increased with age, and mutations had an age-related signature. DNMT3A-mutated and ASXL1-mutated clones tended to increase in size over time; the size of BCOR- and BCORL1-mutated and PIGA-mutated clones decreased or remained stable. Mutations in PIGA and BCOR and BCORL1 correlated with a better response to immunosuppressive therapy and longer and a higher rate of overall and progression-free survival; mutations in a subgroup of genes that included DNMT3A and ASXL1 were associated with worse outcomes. However, clonal dynamics were highly variable and might not necessarily have predicted the response to therapy and long-term survival among individual patients. Clonal hematopoiesis was prevalent in aplastic anemia. Some mutations were related to clinical outcomes. A highly biased set of mutations is evidence of Darwinian selection in the failed bone marrow environment. The pattern of somatic clones in individual patients over time was variable and frequently unpredictable. (Funded by Grant-in-Aid for Scientific Research and others.).

  2. Determination of somatic mutations in human erythrocytes by cytometry

    International Nuclear Information System (INIS)

    Jensen, R.H.; Langlois, R.G.; Bigbee, W.L.

    1985-01-01

    Flow cytometric assays of human erythrocytes labeled with monoclonal antibodies specific for glycophorin A were used to enumerate variant cells that appear in peripheral blood as a result of somatic gene-loss mutations in erythrocyte precursor cells. The assay was performed on erythrocytes from 10 oncology patients who had received at least one treatment from radiation or mutagenic chemotherapy at least 3 weeks before being assayed. The patients were suffering from many different malignancies (e.g., breast, renal, bone, colon and lung), and were treated with several different mutagenic therapeutics (e.g., cisplatinum, adriamycin, daunomycin, or cyclophosphamide). The frequency of these variant cells is an indication of the amount of mutagenic damage accumulated in the individual's erythropoietic cell population. Comparing these results to HPRT clonogenic assays, we find similar baseline frequencies of somatic mutation as well as similar correlation with mutagenic exposures. 9 refs., 3 figs., 1 tab

  3. Determination of somatic mutations in human erythrocytes by cytometry

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    Jensen, R.H.; Langlois, R.G.; Bigbee, W.L.

    1985-06-21

    Flow cytometric assays of human erythrocytes labeled with monoclonal antibodies specific for glycophorin A were used to enumerate variant cells that appear in peripheral blood as a result of somatic gene-loss mutations in erythrocyte precursor cells. The assay was performed on erythrocytes from 10 oncology patients who had received at least one treatment from radiation or mutagenic chemotherapy at least 3 weeks before being assayed. The patients were suffering from many different malignancies (e.g., breast, renal, bone, colon and lung), and were treated with several different mutagenic therapeutics (e.g., cisplatinum, adriamycin, daunomycin, or cyclophosphamide). The frequency of these variant cells is an indication of the amount of mutagenic damage accumulated in the individual's erythropoietic cell population. Comparing these results to HPRT clonogenic assays, we find similar baseline frequencies of somatic mutation as well as similar correlation with mutagenic exposures. 9 refs., 3 figs., 1 tab.

  4. Biallelic germline and somatic mutations in malignant mesothelioma: multiple mutations in transcription regulators including mSWI/SNF genes.

    Science.gov (United States)

    Yoshikawa, Yoshie; Sato, Ayuko; Tsujimura, Tohru; Otsuki, Taiichiro; Fukuoka, Kazuya; Hasegawa, Seiki; Nakano, Takashi; Hashimoto-Tamaoki, Tomoko

    2015-02-01

    We detected low levels of acetylation for histone H3 tail lysines in malignant mesothelioma (MM) cell lines resistant to histone deacetylase inhibitors. To identify the possible genetic causes related to the low histone acetylation levels, whole-exome sequencing was conducted with MM cell lines established from eight patients. A mono-allelic variant of BRD1 was common to two MM cell lines with very low acetylation levels. We identified 318 homozygous protein-damaging variants/mutations (18-78 variants/mutations per patient); annotation analysis showed enrichment of the molecules associated with mammalian SWI/SNF (mSWI/SNF) chromatin remodeling complexes and co-activators that facilitate initiation of transcription. In seven of the patients, we detected a combination of variants in histone modifiers or transcription factors/co-factors, in addition to variants in mSWI/SNF. Direct sequencing showed that homozygous mutations in SMARCA4, PBRM1 and ARID2 were somatic. In one patient, homozygous germline variants were observed for SMARCC1 and SETD2 in chr3p22.1-3p14.2. These exhibited extended germline homozygosity and were in regions containing somatic mutations, leading to a loss of BAP1 and PBRM1 expression in MM cell line. Most protein-damaging variants were heterozygous in normal tissues. Heterozygous germline variants were often converted into hemizygous variants by mono-allelic deletion, and were rarely homozygous because of acquired uniparental disomy. Our findings imply that MM might develop through the somatic inactivation of mSWI/SNF complex subunits and/or histone modifiers, including BAP1, in subjects that have rare germline variants of these transcription regulators and/or transcription factors/co-factors, and in regions prone to mono-allelic deletion during oncogenesis. © 2014 UICC.

  5. Evaluation of Nine Somatic Variant Callers for Detection of Somatic Mutations in Exome and Targeted Deep Sequencing Data.

    Directory of Open Access Journals (Sweden)

    Anne Bruun Krøigård

    Full Text Available Next generation sequencing is extensively applied to catalogue somatic mutations in cancer, in research settings and increasingly in clinical settings for molecular diagnostics, guiding therapy decisions. Somatic variant callers perform paired comparisons of sequencing data from cancer tissue and matched normal tissue in order to detect somatic mutations. The advent of many new somatic variant callers creates a need for comparison and validation of the tools, as no de facto standard for detection of somatic mutations exists and only limited comparisons have been reported. We have performed a comprehensive evaluation using exome sequencing and targeted deep sequencing data of paired tumor-normal samples from five breast cancer patients to evaluate the performance of nine publicly available somatic variant callers: EBCall, Mutect, Seurat, Shimmer, Indelocator, Somatic Sniper, Strelka, VarScan 2 and Virmid for the detection of single nucleotide mutations and small deletions and insertions. We report a large variation in the number of calls from the nine somatic variant callers on the same sequencing data and highly variable agreement. Sequencing depth had markedly diverse impact on individual callers, as for some callers, increased sequencing depth highly improved sensitivity. For SNV calling, we report EBCall, Mutect, Virmid and Strelka to be the most reliable somatic variant callers for both exome sequencing and targeted deep sequencing. For indel calling, EBCall is superior due to high sensitivity and robustness to changes in sequencing depths.

  6. Evaluation of Nine Somatic Variant Callers for Detection of Somatic Mutations in Exome and Targeted Deep Sequencing Data.

    Science.gov (United States)

    Krøigård, Anne Bruun; Thomassen, Mads; Lænkholm, Anne-Vibeke; Kruse, Torben A; Larsen, Martin Jakob

    2016-01-01

    Next generation sequencing is extensively applied to catalogue somatic mutations in cancer, in research settings and increasingly in clinical settings for molecular diagnostics, guiding therapy decisions. Somatic variant callers perform paired comparisons of sequencing data from cancer tissue and matched normal tissue in order to detect somatic mutations. The advent of many new somatic variant callers creates a need for comparison and validation of the tools, as no de facto standard for detection of somatic mutations exists and only limited comparisons have been reported. We have performed a comprehensive evaluation using exome sequencing and targeted deep sequencing data of paired tumor-normal samples from five breast cancer patients to evaluate the performance of nine publicly available somatic variant callers: EBCall, Mutect, Seurat, Shimmer, Indelocator, Somatic Sniper, Strelka, VarScan 2 and Virmid for the detection of single nucleotide mutations and small deletions and insertions. We report a large variation in the number of calls from the nine somatic variant callers on the same sequencing data and highly variable agreement. Sequencing depth had markedly diverse impact on individual callers, as for some callers, increased sequencing depth highly improved sensitivity. For SNV calling, we report EBCall, Mutect, Virmid and Strelka to be the most reliable somatic variant callers for both exome sequencing and targeted deep sequencing. For indel calling, EBCall is superior due to high sensitivity and robustness to changes in sequencing depths.

  7. Inference of Tumor Phylogenies with Improved Somatic Mutation Discovery

    KAUST Repository

    Salari, Raheleh

    2013-01-01

    Next-generation sequencing technologies provide a powerful tool for studying genome evolution during progression of advanced diseases such as cancer. Although many recent studies have employed new sequencing technologies to detect mutations across multiple, genetically related tumors, current methods do not exploit available phylogenetic information to improve the accuracy of their variant calls. Here, we present a novel algorithm that uses somatic single nucleotide variations (SNVs) in multiple, related tissue samples as lineage markers for phylogenetic tree reconstruction. Our method then leverages the inferred phylogeny to improve the accuracy of SNV discovery. Experimental analyses demonstrate that our method achieves up to 32% improvement for somatic SNV calling of multiple related samples over the accuracy of GATK\\'s Unified Genotyper, the state of the art multisample SNV caller. © 2013 Springer-Verlag.

  8. Exome sequencing identifies recurrent somatic RAC1 mutations in melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Krauthammer, Michael; Kong, Yong; Ha, Byung Hak; Evans, Perry; Bacchiocchi, Antonella; McCusker, James P.; Cheng, Elaine; Davis, Matthew J.; Goh, Gerald; Choi, Murim; Ariyan, Stephan; Narayan, Deepak; Dutton-Regester, Ken; Capatana, Ana; Holman, Edna C.; Bosenberg, Marcus; Sznol, Mario; Kluger, Harriet M.; Brash, Douglas E.; Stern, David F.; Materin, Miguel A.; Lo, Roger S.; Mane, Shrikant; Ma, Shuangge; Kidd, Kenneth K.; Hayward, Nicholas K.; Lifton, Richard P.; Schlessinger, Joseph; Boggon, Titus J.; Halaban, Ruth (Yale-MED); (UCLA); (Queens)

    2012-10-11

    We characterized the mutational landscape of melanoma, the form of skin cancer with the highest mortality rate, by sequencing the exomes of 147 melanomas. Sun-exposed melanomas had markedly more ultraviolet (UV)-like C>T somatic mutations compared to sun-shielded acral, mucosal and uveal melanomas. Among the newly identified cancer genes was PPP6C, encoding a serine/threonine phosphatase, which harbored mutations that clustered in the active site in 12% of sun-exposed melanomas, exclusively in tumors with mutations in BRAF or NRAS. Notably, we identified a recurrent UV-signature, an activating mutation in RAC1 in 9.2% of sun-exposed melanomas. This activating mutation, the third most frequent in our cohort of sun-exposed melanoma after those of BRAF and NRAS, changes Pro29 to serine (RAC1{sup P29S}) in the highly conserved switch I domain. Crystal structures, and biochemical and functional studies of RAC1{sup P29S} showed that the alteration releases the conformational restraint conferred by the conserved proline, causes an increased binding of the protein to downstream effectors, and promotes melanocyte proliferation and migration. These findings raise the possibility that pharmacological inhibition of downstream effectors of RAC1 signaling could be of therapeutic benefit.

  9. Gastrointestinal stromal tumors, somatic mutations and candidate genetic risk variants.

    Directory of Open Access Journals (Sweden)

    Katie M O'Brien

    Full Text Available Gastrointestinal stromal tumors (GISTs are rare but treatable soft tissue sarcomas. Nearly all GISTs have somatic mutations in either the KIT or PDGFRA gene, but there are no known inherited genetic risk factors. We assessed the relationship between KIT/PDGFRA mutations and select deletions or single nucleotide polymorphisms (SNPs in 279 participants from a clinical trial of adjuvant imatinib mesylate. Given previous evidence that certain susceptibility loci and carcinogens are associated with characteristic mutations, or "signatures" in other cancers, we hypothesized that the characteristic somatic mutations in the KIT and PDGFRA genes in GIST tumors may similarly be mutational signatures that are causally linked to specific mutagens or susceptibility loci. As previous epidemiologic studies suggest environmental risk factors such as dioxin and radiation exposure may be linked to sarcomas, we chose 208 variants in 39 candidate genes related to DNA repair and dioxin metabolism or response. We calculated adjusted odds ratios (ORs and 95% confidence intervals (CIs for the association between each variant and 7 categories of tumor mutation using logistic regression. We also evaluated gene-level effects using the sequence kernel association test (SKAT. Although none of the association p-values were statistically significant after adjustment for multiple comparisons, SNPs in CYP1B1 were strongly associated with KIT exon 11 codon 557-8 deletions (OR = 1.9, 95% CI: 1.3-2.9 for rs2855658 and OR = 1.8, 95% CI: 1.2-2.7 for rs1056836 and wild type GISTs (OR = 2.7, 95% CI: 1.5-4.8 for rs1800440 and OR = 0.5, 95% CI: 0.3-0.9 for rs1056836. CYP1B1 was also associated with these mutations categories in the SKAT analysis (p = 0.002 and p = 0.003, respectively. Other potential risk variants included GSTM1, RAD23B and ERCC2. This preliminary analysis of inherited genetic risk factors for GIST offers some clues about the disease's genetic

  10. A pathway-centric survey of somatic mutations in Chinese patients with colorectal carcinomas.

    Directory of Open Access Journals (Sweden)

    Chao Ling

    Full Text Available Previous genetic studies on colorectal carcinomas (CRC have identified multiple somatic mutations in four candidate pathways (TGF-β, Wnt, P53 and RTK-RAS pathways on populations of European ancestry. However, it is under-studied whether other populations harbor different sets of hot-spot somatic mutations in these pathways and other oncogenes. In this study, to evaluate the mutational spectrum of novel somatic mutations, we assessed 41 pairs of tumor-stroma tissues from Chinese patients with CRC, including 29 colon carcinomas and 12 rectal carcinomas. We designed Illumina Custom Amplicon panel to target 43 genes, including genes in the four candidate pathways, as well as several known oncogenes for other cancers. Candidate mutations were validated by Sanger sequencing, and we further used SIFT and PolyPhen-2 to assess potentially functional mutations. We discovered 3 new somatic mutations in gene APC, TCF7L2, and PIK3CA that had never been reported in the COSMIC or NCI-60 databases. Additionally, we confirmed 6 known somatic mutations in gene SMAD4, APC, FBXW7, BRAF and PTEN in Chinese CRC patients. While most were previously reported in CRC, one mutation in PTEN was reported only in malignant endometrium cancer. Our study confirmed the existence of known somatic mutations in the four candidate pathways for CRC in Chinese patients. We also discovered a number of novel somatic mutations in these pathways, which may have implications for the pathogenesis of CRC.

  11. Novel somatic and germline mutations in intracranial germ cell tumours.

    Science.gov (United States)

    Wang, Linghua; Yamaguchi, Shigeru; Burstein, Matthew D; Terashima, Keita; Chang, Kyle; Ng, Ho-Keung; Nakamura, Hideo; He, Zongxiao; Doddapaneni, Harshavardhan; Lewis, Lora; Wang, Mark; Suzuki, Tomonari; Nishikawa, Ryo; Natsume, Atsushi; Terasaka, Shunsuke; Dauser, Robert; Whitehead, William; Adekunle, Adesina; Sun, Jiayi; Qiao, Yi; Marth, Gábor; Muzny, Donna M; Gibbs, Richard A; Leal, Suzanne M; Wheeler, David A; Lau, Ching C

    2014-07-10

    Intracranial germ cell tumours (IGCTs) are a group of rare heterogeneous brain tumours that are clinically and histologically similar to the more common gonadal GCTs. IGCTs show great variation in their geographical and gender distribution, histological composition and treatment outcomes. The incidence of IGCTs is historically five- to eightfold greater in Japan and other East Asian countries than in Western countries, with peak incidence near the time of puberty. About half of the tumours are located in the pineal region. The male-to-female incidence ratio is approximately 3-4:1 overall, but is even higher for tumours located in the pineal region. Owing to the scarcity of tumour specimens available for research, little is currently known about this rare disease. Here we report the analysis of 62 cases by next-generation sequencing, single nucleotide polymorphism array and expression array. We find the KIT/RAS signalling pathway frequently mutated in more than 50% of IGCTs, including novel recurrent somatic mutations in KIT, its downstream mediators KRAS and NRAS, and its negative regulator CBL. Novel somatic alterations in the AKT/mTOR pathway included copy number gains of the AKT1 locus at 14q32.33 in 19% of patients, with corresponding upregulation of AKT1 expression. We identified loss-of-function mutations in BCORL1, a transcriptional co-repressor and tumour suppressor. We report significant enrichment of novel and rare germline variants in JMJD1C, which codes for a histone demethylase and is a coactivator of the androgen receptor, among Japanese IGCT patients. This study establishes a molecular foundation for understanding the biology of IGCTs and suggests potentially promising therapeutic strategies focusing on the inhibition of KIT/RAS activation and the AKT1/mTOR pathway.

  12. Novel somatic and germline mutations in intracranial germ cell tumors

    Science.gov (United States)

    Wang, Linghua; Yamaguchi, Shigeru; Burstein, Matthew D.; Terashima, Keita; Chang, Kyle; Ng, Ho-Keung; Nakamura, Hideo; He, Zongxiao; Doddapaneni, Harshavardhan; Lewis, Lora; Wang, Mark; Suzuki, Tomonari; Nishikawa, Ryo; Natsume, Atsushi; Terasaka, Shunsuke; Dauser, Robert; Whitehead, William; Adekunle, Adesina; Sun, Jiayi; Qiao, Yi; Marth, Gábor; Muzny, Donna M.; Gibbs, Richard A.; Leal, Suzanne M.; Wheeler, David A.; Lau, Ching C.

    2015-01-01

    Intracranial germ cell tumors (IGCTs) are a group of rare heterogeneous brain tumors which are clinically and histologically similar to the more common gonadal GCTs. IGCTs show great variation in their geographic and gender distribution, histological composition and treatment outcomes. The incidence of IGCTs is historically 5–8 fold greater in Japan and other East Asian countries than in Western countries1 with peak incidence near the time of puberty2. About half of the tumors are located in the pineal region. The male-to-female incidence ratio is approximately 3–4:1 overall but even higher for tumors located in the pineal region3. Due to the scarcity of tumor specimens available for research, little is currently known about this rare disease. Here we report the analysis of 62 cases by next generation sequencing, SNP array and expression array. We find the KIT/RAS signaling pathway frequently mutated in over 50% of IGCTs including novel recurrent somatic mutations in KIT, its downstream mediators KRAS and NRAS, and its negative regulator CBL. Novel somatic alterations in the AKT/mTOR pathway included copy number gain of the AKT1 locus at 14q32.33 in 19% of patients, with corresponding upregulation of AKT1 expression. We identified loss-of-function mutations in BCORL1, a transcriptional corepressor and tumor suppressor. We report significant enrichment of novel and rare germline variants in JMJD1C, a histone demethylase and coactivator of the androgen receptor, among Japanese IGCT patients. This study establishes a molecular foundation for understanding the biology of IGCTs and suggests potentially promising therapeutic strategies focusing on the inhibition of KIT/RAS activation and the AKT1/mTOR pathway. PMID:24896186

  13. Somatic gene mutation in the human in relation to radiation risk

    International Nuclear Information System (INIS)

    Mendelsohn, M.L.

    1992-01-01

    This report discusses the measurement of somatic gene-mutation frequencies in the human. We ask the following questions. How well can they be measured? Do they respond to radiation? Can they also function as a dosimeter? What do they tell us about the somatic mutation theory of carcinogenesis?

  14. Induction of somatic mutation in chrysanthemum cultivar 'Anupam'

    International Nuclear Information System (INIS)

    Banerji, B.K.; Datta, S.K.

    1990-01-01

    Rooted cuttings of chrysanthemum cv. 'Anupam' were irradiated with 1.5, 2.0 and 2.5 Krad of gamma rays. Significant reduction in survival, plant height, branch, leaf and flower head number and leaf size were recorded after irradiation. Radio sensitivity was determined on the basis of different cytomorphological parameters. Different types of morphological abnormalities in leaves and flower and chromosomal abnormalities during root tip mitosis were observed and the total abnormalities increased with increase in exposure to gamma rays. Significant delay in flower bud initiation, first colour showing and full bloom were recorded in the treated population. Somatic mutations in flower colour could be induced in vM 1 as chimera and a total of three flower colour mutant, i.e., lighter, white and striped were isolated and established in pure form as new cultivars which are of direct use for floriculture industry. (author). 17 refs., 6 figs. , 2 tabs

  15. Population-based statistical inference for temporal sequence of somatic mutations in cancer genomes.

    Science.gov (United States)

    Rhee, Je-Keun; Kim, Tae-Min

    2018-04-20

    It is well recognized that accumulation of somatic mutations in cancer genomes plays a role in carcinogenesis; however, the temporal sequence and evolutionary relationship of somatic mutations remain largely unknown. In this study, we built a population-based statistical framework to infer the temporal sequence of acquisition of somatic mutations. Using the model, we analyzed the mutation profiles of 1954 tumor specimens across eight tumor types. As a result, we identified tumor type-specific directed networks composed of 2-15 cancer-related genes (nodes) and their mutational orders (edges). The most common ancestors identified in pairwise comparison of somatic mutations were TP53 mutations in breast, head/neck, and lung cancers. The known relationship of KRAS to TP53 mutations in colorectal cancers was identified, as well as potential ancestors of TP53 mutation such as NOTCH1, EGFR, and PTEN mutations in head/neck, lung and endometrial cancers, respectively. We also identified apoptosis-related genes enriched with ancestor mutations in lung cancers and a relationship between APC hotspot mutations and TP53 mutations in colorectal cancers. While evolutionary analysis of cancers has focused on clonal versus subclonal mutations identified in individual genomes, our analysis aims to further discriminate ancestor versus descendant mutations in population-scale mutation profiles that may help select cancer drivers with clinical relevance.

  16. Somatic mutations in leafs of tobacco seedlings induced by ionizing radiation and pesticide

    International Nuclear Information System (INIS)

    Shin, H. S.; Kim, J. K.; Song, H. S.; Lee, Y. I.

    2001-01-01

    Somatic mutations induced by the combined treatment of pesticide and ionizing radiation were analyzed in the leaves of tobacco seedlings. The pesticide (1,5 and 10 ppm of parathion) was sprayed directly onto the seedlings. The seedlings, with or without pretreatment of pesticide, were irradiated with 0.1 ∼10 Gy of gamma ray. The difference in the somatic mutation frequencies were not significant among groups treated with different concentration of pesticide. The somatic mutations in tobacco seedlings irradiated with gamma-ray showed a clear dose-response relationship in a range of 0.1 to 10 Gy. However, the combined treatment of pesticide and radiation did not cause any synergistic enhancement in the mutation frequencies. The highest efficiency in the induction of somatic mutations could be obtained by irradiating the seedlings with 5 Gy, 12 hours after 1 ppm of pesticide treatment, or 24 hours after 5 ppm of pesticide treatment

  17. Improvement of some ornamental plants by induced somatic mutations at National Botanical Research Institute

    International Nuclear Information System (INIS)

    Gupta, M.N.

    1980-01-01

    Research work on improvement of some ornamental plants by induced somatic mutations has been in progress at the National Botanical Research Institute, Lucknow, since 1964. The methods of treatments with gamma rays, detection, isolation and multiplication of induced somatic mutations have been given for Bougainvillea, Chrysanthemum, perennial Portulaca, rose and tuberose. During the last 15 years, a total of 38 new cultivars of different ornamentals evolved by gamna induced somatic mutations have been released. They include Bougainvillea 1; Chrysanthemum 28; perennial portulaca 6; rose 1 and tuberose 2. Descriptions of the original cultivars and their gamma induced mutants are given along with other pertinent details. (author)

  18. Somatic FAS mutations are common in patients with genetically undefined autoimmune lymphoproliferative syndrome.

    Science.gov (United States)

    Dowdell, Kennichi C; Niemela, Julie E; Price, Susan; Davis, Joie; Hornung, Ronald L; Oliveira, João Bosco; Puck, Jennifer M; Jaffe, Elaine S; Pittaluga, Stefania; Cohen, Jeffrey I; Fleisher, Thomas A; Rao, V Koneti

    2010-06-24

    Autoimmune lymphoproliferative syndrome (ALPS) is characterized by childhood onset of lymphadenopathy, hepatosplenomegaly, autoimmune cytopenias, elevated numbers of double-negative T (DNT) cells, and increased risk of lymphoma. Most cases of ALPS are associated with germline mutations of the FAS gene (type Ia), whereas some cases have been noted to have a somatic mutation of FAS primarily in their DNT cells. We sought to determine the proportion of patients with somatic FAS mutations among a group of our ALPS patients with no detectable germline mutation and to further characterize them. We found more than one-third (12 of 31) of the patients tested had somatic FAS mutations, primarily involving the intracellular domain of FAS resulting in loss of normal FAS signaling. Similar to ALPS type Ia patients, the somatic ALPS patients had increased DNT cell numbers and elevated levels of serum vitamin B(12), interleukin-10, and sFAS-L. These data support testing for somatic FAS mutations in DNT cells from ALPS patients with no detectable germline mutation and a similar clinical and laboratory phenotype to that of ALPS type Ia. These findings also highlight the potential role for somatic mutations in the pathogenesis of nonmalignant and/or autoimmune hematologic conditions in adults and children.

  19. Clinical significance of acquired somatic mutations in aplastic anaemia.

    Science.gov (United States)

    Marsh, J C W; Mufti, G J

    2016-08-01

    Aplastic anaemia (AA) is frequently associated with other disorders of clonal haemopoiesis such as paroxysmal nocturnal haemoglobinuria (PNH), myelodysplastic syndrome (MDS) and T-large granular lymphocytosis. Certain clones may escape the immune attack within the bone marrow environment and proliferate and attain a survival advantage over normal haemopoietic stem cells, such as trisomy 8, loss of heterozygosity of short arm of chromosome 6 and del13q clones. Recently acquired somatic mutations (SM), excluding PNH clones, have been reported in around 20-25 % of patients with AA, which predispose to a higher risk of later malignant transformation to MDS/acute myeloid leukaemia. Furthermore, certain SM, such as ASXL1 and DNMT3A are associated with poor survival following immunosuppressive therapy, whereas PIGA, BCOR/BCORL1 predict for good response and survival. Further detailed and serial analysis of the immune signature in AA is needed to understand the pathogenetic basis for the presence of clones with SM in a significant proportion of patients.

  20. Significance of somatic mutations and content alteration of mitochondrial DNA in esophageal cancer

    Directory of Open Access Journals (Sweden)

    Wang Yu-Fen

    2006-04-01

    Full Text Available Abstract Background The roles of mitochondria in energy metabolism, the generation of ROS, aging, and the initiation of apoptosis have implicated their importance in tumorigenesis. In this study we aim to establish the mutation spectrum and to understand the role of somatic mtDNA mutations in esophageal cancer. Methods The entire mitochondrial genome was screened for somatic mutations in 20 pairs (18 esophageal squamous cell carcinomas, one adenosquamous carcinoma and one adenocarcinoma of tumor/surrounding normal tissue of esophageal cancers, using temporal temperature gradient gel electrophoresis (TTGE, followed by direct DNA sequencing to identify the mutations. Results Fourteen somatic mtDNA mutations were identified in 55% (11/20 of tumors analyzed, including 2 novel missense mutations and a frameshift mutation in ND4L, ATP6 subunit, and ND4 genes respectively. Nine mutations (64% were in the D-loop region. Numerous germline variations were found, at least 10 of them were novel and five were missense mutations, some of them occurred in evolutionarily conserved domains. Using real-time quantitative PCR analysis, the mtDNA content was found to increase in some tumors and decrease in others. Analysis of molecular and other clinicopathological findings does not reveal significant correlation between somatic mtDNA mutations and mtDNA content, or between mtDNA content and metastatic status. Conclusion Our results demonstrate that somatic mtDNA mutations in esophageal cancers are frequent. Some missense and frameshift mutations may play an important role in the tumorigenesis of esophageal carcinoma. More extensive biochemical and molecular studies will be necessary to determine the pathological significance of these somatic mutations.

  1. No evidence of somatic aryl hydrocarbon receptor interacting protein mutations in sporadic endocrine neoplasia

    DEFF Research Database (Denmark)

    Raitila, A; Georgitsi, M; Karhu, A

    2007-01-01

    . Here, we have analyzed 32 pituitary adenomas and 79 other tumors of the endocrine system for somatic AIP mutations by direct sequencing. No somatic mutations were identified. However, two out of nine patients with prolactin-producing adenoma were shown to harbor a Finnish founder mutation (Q14X...... as non-secreting pituitary adenomas have been reported, most mutation-positive patients have had growth hormone-producing adenomas diagnosed at relatively young age. Pituitary adenomas are also component tumors of some familial endocrine neoplasia syndromes such as multiple endocrine neoplasia type 1...... (MEN1) and Carney complex (CNC). Genes underlying MEN1 and CNC are rarely mutated in sporadic pituitary adenomas, but more often in other lesions contributing to these two syndromes. Thus far, the occurrence of somatic AIP mutations has not been studied in endocrine tumors other than pituitary adenomas...

  2. Somatic USP8 Gene Mutations Are a Common Cause of Pediatric Cushing Disease.

    Science.gov (United States)

    Faucz, Fabio R; Tirosh, Amit; Tatsi, Christina; Berthon, Annabel; Hernández-Ramírez, Laura C; Settas, Nikolaos; Angelousi, Anna; Correa, Ricardo; Papadakis, Georgios Z; Chittiboina, Prashant; Quezado, Martha; Pankratz, Nathan; Lane, John; Dimopoulos, Aggeliki; Mills, James L; Lodish, Maya; Stratakis, Constantine A

    2017-08-01

    Somatic mutations in the ubiquitin-specific protease 8 (USP8) gene have been recently identified as the most common genetic alteration in patients with Cushing disease (CD). However, the frequency of these mutations in the pediatric population has not been extensively assessed. We investigated the status of the USP8 gene at the somatic level in a cohort of pediatric patients with corticotroph adenomas. The USP8 gene was fully sequenced in both germline and tumor DNA samples from 42 pediatric patients with CD. Clinical, biochemical, and imaging data were compared between patients with and without somatic USP8 mutations. Five different USP8 mutations (three missense, one frameshift, and one in-frame deletion) were identified in 13 patients (31%), all of them located in exon 14 at the previously described mutational hotspot, affecting the 14-3-3 binding motif of the protein. Patients with somatic mutations were older at disease presentation [mean 5.1 ± 2.1 standard deviation (SD) vs 13.1 ± 3.6 years, P = 0.03]. Levels of urinary free cortisol, midnight serum cortisol, and adrenocorticotropic hormone, as well as tumor size and frequency of invasion of the cavernous sinus, were not significantly different between the two groups. However, patients harboring somatic USP8 mutations had a higher likelihood of recurrence compared with patients without mutations (46.2% vs 10.3%, P = 0.009). Somatic USP8 gene mutations are a common cause of pediatric CD. Patients harboring a somatic mutation had a higher likelihood of tumor recurrence, highlighting the potential importance of this molecular defect for the disease prognosis and the development of targeted therapeutic options. Copyright © 2017 Endocrine Society

  3. Inactivation and inducible oncogenic mutation of p53 in gene targeted pigs.

    Directory of Open Access Journals (Sweden)

    Simon Leuchs

    Full Text Available Mutation of the tumor suppressor p53 plays a major role in human carcinogenesis. Here we describe gene-targeted porcine mesenchymal stem cells (MSCs and live pigs carrying a latent TP53(R167H mutant allele, orthologous to oncogenic human mutant TP53(R175H and mouse Trp53(R172H, that can be activated by Cre recombination. MSCs carrying the latent TP53(R167H mutant allele were analyzed in vitro. Homozygous cells were p53 deficient, and on continued culture exhibited more rapid proliferation, anchorage independent growth, and resistance to the apoptosis-inducing chemotherapeutic drug doxorubicin, all characteristic of cellular transformation. Cre mediated recombination activated the latent TP53(R167H allele as predicted, and in homozygous cells expressed mutant p53-R167H protein at a level ten-fold greater than wild-type MSCs, consistent with the elevated levels found in human cancer cells. Gene targeted MSCs were used for nuclear transfer and fifteen viable piglets were produced carrying the latent TP53(R167H mutant allele in heterozygous form. These animals will allow study of p53 deficiency and expression of mutant p53-R167H to model human germline, or spontaneous somatic p53 mutation. This work represents the first inactivation and mutation of the gatekeeper tumor suppressor gene TP53 in a non-rodent mammal.

  4. Somatic embryogenesis in cassava: A tool for mutation breeding

    International Nuclear Information System (INIS)

    Lee, K.S.; Duren, M. Van; Morpurgo, R.

    1997-01-01

    Cassava is an important food and livestock feed crop. The effect of gamma radiation on somatic embryogenesis and plant regeneration in cassava clones of African origin was investigated. Explants from young leaves of cassava were cultured on MS medium, supplemented with 18.1 mM 2,4-D and 2 mM CuSO4, solidified with 0.3% Phytagel. Compact and friable calli were observed after 10-15 days of explant culture in dark, which produced somatic embryos in all but one clone. The somatic embryos showed morphological aberrations, such as fused cotyledons, lack of meristematic tip, epicotyl elongation, and had low germination rate; desiccation of embryos increased germination. Histological study showed that the somatic embryos were of multicellular origin. Leaf explants were irradiated with doses between 4 to 38 Gy of gamma rays, and cultured on somatic embryo induction medium. In addition, somatic embryos were irradiated with gamma ray doses from 10 to 18 Gy, and analyzed for germination. LD 50 for embryogenic response of leaf-explants was at around 20 Gy, while that for somatic embryo germination was ca. 10 Gy. (author). 7 refs, 2 tabs

  5. Somatic embryogenesis in cassava: A tool for mutation breeding

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K S; Duren, M Van; Morpurgo, R [Agriculture and Biotechnology Laboratory, International Atomic Energy Agency, Seibersdorf (Austria)

    1997-07-01

    Cassava is an important food and livestock feed crop. The effect of gamma radiation on somatic embryogenesis and plant regeneration in cassava clones of African origin was investigated. Explants from young leaves of cassava were cultured on MS medium, supplemented with 18.1 mM 2,4-D and 2 mM CuSO4, solidified with 0.3% Phytagel. Compact and friable calli were observed after 10-15 days of explant culture in dark, which produced somatic embryos in all but one clone. The somatic embryos showed morphological aberrations, such as fused cotyledons, lack of meristematic tip, epicotyl elongation, and had low germination rate; desiccation of embryos increased germination. Histological study showed that the somatic embryos were of multicellular origin. Leaf explants were irradiated with doses between 4 to 38 Gy of gamma rays, and cultured on somatic embryo induction medium. In addition, somatic embryos were irradiated with gamma ray doses from 10 to 18 Gy, and analyzed for germination. LD{sub 50} for embryogenic response of leaf-explants was at around 20 Gy, while that for somatic embryo germination was ca. 10 Gy. (author). 7 refs, 2 tabs.

  6. Inference of Tumor Phylogenies with Improved Somatic Mutation Discovery

    KAUST Repository

    Salari, Raheleh; Saleh, Syed Shayon; Kashef-Haghighi, Dorna; Khavari, David; Newburger, Daniel E.; West, Robert B.; Sidow, Arend; Batzoglou, Serafim

    2013-01-01

    multiple, genetically related tumors, current methods do not exploit available phylogenetic information to improve the accuracy of their variant calls. Here, we present a novel algorithm that uses somatic single nucleotide variations (SNVs) in multiple

  7. Statistical method on nonrandom clustering with application to somatic mutations in cancer

    Directory of Open Access Journals (Sweden)

    Rejto Paul A

    2010-01-01

    Full Text Available Abstract Background Human cancer is caused by the accumulation of tumor-specific mutations in oncogenes and tumor suppressors that confer a selective growth advantage to cells. As a consequence of genomic instability and high levels of proliferation, many passenger mutations that do not contribute to the cancer phenotype arise alongside mutations that drive oncogenesis. While several approaches have been developed to separate driver mutations from passengers, few approaches can specifically identify activating driver mutations in oncogenes, which are more amenable for pharmacological intervention. Results We propose a new statistical method for detecting activating mutations in cancer by identifying nonrandom clusters of amino acid mutations in protein sequences. A probability model is derived using order statistics assuming that the location of amino acid mutations on a protein follows a uniform distribution. Our statistical measure is the differences between pair-wise order statistics, which is equivalent to the size of an amino acid mutation cluster, and the probabilities are derived from exact and approximate distributions of the statistical measure. Using data in the Catalog of Somatic Mutations in Cancer (COSMIC database, we have demonstrated that our method detects well-known clusters of activating mutations in KRAS, BRAF, PI3K, and β-catenin. The method can also identify new cancer targets as well as gain-of-function mutations in tumor suppressors. Conclusions Our proposed method is useful to discover activating driver mutations in cancer by identifying nonrandom clusters of somatic amino acid mutations in protein sequences.

  8. Biological and clinical evidence for somatic mutations in BRCA1 and BRCA2 as predictive markers for olaparib response in high-grade serous ovarian cancers in the maintenance setting.

    Science.gov (United States)

    Dougherty, Brian A; Lai, Zhongwu; Hodgson, Darren R; Orr, Maria C M; Hawryluk, Matthew; Sun, James; Yelensky, Roman; Spencer, Stuart K; Robertson, Jane D; Ho, Tony W; Fielding, Anitra; Ledermann, Jonathan A; Barrett, J Carl

    2017-07-04

    To gain a better understanding of the role of somatic mutations in olaparib response, next-generation sequencing (NGS) of BRCA1 and BRCA2 was performed as part of a planned retrospective analysis of tumors from a randomized, double-blind, Phase II trial (Study 19; D0810C00019; NCT00753545) in 265 patients with platinum-sensitive high-grade serous ovarian cancer. BRCA1/2 loss-of-function mutations were found in 55% (114/209) of tumors, were mutually exclusive, and demonstrated high concordance with Sanger-sequenced germline mutations in matched blood samples, confirming the accuracy (97%) of tumor BRCA1/2 NGS testing. Additionally, NGS identified somatic mutations absent from germline testing in 10% (20/209) of the patients. Somatic mutations had >80% biallelic inactivation frequency and were predominantly clonal, suggesting that BRCA1/2 loss occurs early in the development of these cancers. Clinical outcomes between placebo- and olaparib-treated patients with somatic BRCA1/2 mutations were similar to those with germline BRCA1/2 mutations, indicating that patients with somatic BRCA1/2 mutations benefit from treatment with olaparib.

  9. Genetic improvement of sweet potato through somatic embyrogenesis and in vitro induction of mutations

    Energy Technology Data Exchange (ETDEWEB)

    Sonnino, A; Thinh, N T; Santangelo, E; Mini, P [Centro Ricerche Energia, ENEA, Rome (Italy)

    1997-07-01

    Mutation breeding is a promising option for the genetic improvement of sweet potato. Callus induction, somatic embryogenesis and plant regeneration was investigated in twenty-two sweet potato varieties of different origin. Plant regeneration was found to depend on the genotype and composition of the induction medium. The regeneration through somatic embryogenesis induced morphological and physiological changes among the regenerated plants. The irradiation with 30 to 50 Gy of meristems before culture on induction medium inhibited somatic embryogenesis. A number of accessions were evaluated in field trials and showed wide differences in yield. (author). 6 refs, 6 tabs.

  10. Genetic improvement of sweet potato through somatic embyrogenesis and in vitro induction of mutations

    International Nuclear Information System (INIS)

    Sonnino, A.; Thinh, N.T.; Santangelo, E.; Mini, P.

    1997-01-01

    Mutation breeding is a promising option for the genetic improvement of sweet potato. Callus induction, somatic embryogenesis and plant regeneration was investigated in twenty-two sweet potato varieties of different origin. Plant regeneration was found to depend on the genotype and composition of the induction medium. The regeneration through somatic embryogenesis induced morphological and physiological changes among the regenerated plants. The irradiation with 30 to 50 Gy of meristems before culture on induction medium inhibited somatic embryogenesis. A number of accessions were evaluated in field trials and showed wide differences in yield. (author). 6 refs, 6 tabs

  11. Germline and somatic mutations in the MTOR gene in focal cortical dysplasia and epilepsy

    DEFF Research Database (Denmark)

    Møller, Rikke S; Weckhuysen, Sarah; Chipaux, Mathilde

    2016-01-01

    OBJECTIVE: To assess the prevalence of somatic MTOR mutations in focal cortical dysplasia (FCD) and of germline MTOR mutations in a broad range of epilepsies. METHODS: We collected 20 blood-brain paired samples from patients with FCD and searched for somatic variants using deep-targeted gene panel...... sequencing. Germline mutations in MTOR were assessed in a French research cohort of 93 probands with focal epilepsies and in a diagnostic Danish cohort of 245 patients with a broad range of epilepsies. Data sharing among collaborators allowed us to ascertain additional germline variants in MTOR. RESULTS: We...... detected recurrent somatic variants (p.Ser2215Phe, p.Ser2215Tyr, and p.Leu1460Pro) in the MTOR gene in 37% of participants with FCD II and showed histologic evidence for activation of the mTORC1 signaling cascade in brain tissue. We further identified 5 novel de novo germline missense MTOR variants in 6...

  12. Correlation of RET somatic mutations with clinicopathological features in sporadic medullary thyroid carcinomas

    Science.gov (United States)

    Moura, M M; Cavaco, B M; Pinto, A E; Domingues, R; Santos, J R; Cid, M O; Bugalho, M J; Leite, V

    2009-01-01

    Screening of REarranged during Transfection (RET) gene mutations has been carried out in different series of sporadic medullary thyroid carcinomas (MTC). RET-positive tumours seem to be associated to a worse clinical outcome. However, the correlation between the type of RET mutation and the patients' clinicopathological data has not been evaluated yet. We analysed RET exons 5, 8, 10–16 in fifty-one sporadic MTC, and found somatic mutations in thirty-three (64.7%) tumours. Among the RET-positive cases, exon 16 was the most frequently affected (60.6%). Two novel somatic mutations (Cys630Gly, c.1881del18) were identified. MTC patients were divided into three groups: group 1, with mutations in RET exons 15 and 16; group 2, with other RET mutations; group 3, having no RET mutations. Group 1 had higher prevalence (P=0.0051) and number of lymph node metastases (P=0.0017), and presented more often multifocal tumours (P=0.037) and persistent disease at last control (P=0.0242) than group 2. Detectable serum calcitonin levels at last screening (P=0.0119) and stage IV disease (P=0.0145) were more frequent in group 1, than in the other groups. Our results suggest that, among the sporadic MTC, cases with RET mutations in exons 15 and 16 are associated with the worst prognosis. Cases with other RET mutations have the most indolent course, and those with no RET mutations have an intermediate risk. PMID:19401695

  13. Somatic mutations in breast and serous ovarian cancer young patients : a systematic review and meta-analysis

    NARCIS (Netherlands)

    Encinas, Giselly; Maistro, Simone; Pasini, Fatima Solange; Hirata Katayama, Maria Lucia; Brentani, Maria Mitzi; de Bock, Geertruida Hendrika; Azevedo Koike Folgueira, Maria Aparecida

    2015-01-01

    Objective: our aim was to evaluate whether somatic mutations in five genes were associated with an early age at presentation of breast cancer (BC) or serous ovarian cancer (SOC). Methods: COSMIC database was searched for the five most frequent somatic mutations in BC and SOC. A systematic review of

  14. Somatic RET mutation in a patient with pigmented adrenal pheochromocytoma

    NARCIS (Netherlands)

    Maison, Nicole; Korpershoek, Esther; Eisenhofer, Graeme; Robledo, Mercedes; de Krijger, Ronald; Beuschlein, Felix

    UNLABELLED: Pheochromocytomas (PCC) and paraganglioma (PGL) are rare neuroendocrine tumors arising from chromaffin cells of the neural crest. Mutations in the RET-proto-oncogene are associated with sporadic pheochromocytoma, familial or sporadic medullary thyroid carcinoma (MTC) and multiple

  15. Cis-regulatory somatic mutations and gene-expression alteration in B-cell lymphomas.

    Science.gov (United States)

    Mathelier, Anthony; Lefebvre, Calvin; Zhang, Allen W; Arenillas, David J; Ding, Jiarui; Wasserman, Wyeth W; Shah, Sohrab P

    2015-04-23

    With the rapid increase of whole-genome sequencing of human cancers, an important opportunity to analyze and characterize somatic mutations lying within cis-regulatory regions has emerged. A focus on protein-coding regions to identify nonsense or missense mutations disruptive to protein structure and/or function has led to important insights; however, the impact on gene expression of mutations lying within cis-regulatory regions remains under-explored. We analyzed somatic mutations from 84 matched tumor-normal whole genomes from B-cell lymphomas with accompanying gene expression measurements to elucidate the extent to which these cancers are disrupted by cis-regulatory mutations. We characterize mutations overlapping a high quality set of well-annotated transcription factor binding sites (TFBSs), covering a similar portion of the genome as protein-coding exons. Our results indicate that cis-regulatory mutations overlapping predicted TFBSs are enriched in promoter regions of genes involved in apoptosis or growth/proliferation. By integrating gene expression data with mutation data, our computational approach culminates with identification of cis-regulatory mutations most likely to participate in dysregulation of the gene expression program. The impact can be measured along with protein-coding mutations to highlight key mutations disrupting gene expression and pathways in cancer. Our study yields specific genes with disrupted expression triggered by genomic mutations in either the coding or the regulatory space. It implies that mutated regulatory components of the genome contribute substantially to cancer pathways. Our analyses demonstrate that identifying genomically altered cis-regulatory elements coupled with analysis of gene expression data will augment biological interpretation of mutational landscapes of cancers.

  16. Detection of somatic mutations by high-resolution DNA melting (HRM) analysis in multiple cancers.

    Science.gov (United States)

    Gonzalez-Bosquet, Jesus; Calcei, Jacob; Wei, Jun S; Garcia-Closas, Montserrat; Sherman, Mark E; Hewitt, Stephen; Vockley, Joseph; Lissowska, Jolanta; Yang, Hannah P; Khan, Javed; Chanock, Stephen

    2011-01-17

    Identification of somatic mutations in cancer is a major goal for understanding and monitoring the events related to cancer initiation and progression. High resolution melting (HRM) curve analysis represents a fast, post-PCR high-throughput method for scanning somatic sequence alterations in target genes. The aim of this study was to assess the sensitivity and specificity of HRM analysis for tumor mutation screening in a range of tumor samples, which included 216 frozen pediatric small rounded blue-cell tumors as well as 180 paraffin-embedded tumors from breast, endometrial and ovarian cancers (60 of each). HRM analysis was performed in exons of the following candidate genes known to harbor established commonly observed mutations: PIK3CA, ERBB2, KRAS, TP53, EGFR, BRAF, GATA3, and FGFR3. Bi-directional sequencing analysis was used to determine the accuracy of the HRM analysis. For the 39 mutations observed in frozen samples, the sensitivity and specificity of HRM analysis were 97% and 87%, respectively. There were 67 mutation/variants in the paraffin-embedded samples, and the sensitivity and specificity for the HRM analysis were 88% and 80%, respectively. Paraffin-embedded samples require higher quantity of purified DNA for high performance. In summary, HRM analysis is a promising moderate-throughput screening test for mutations among known candidate genomic regions. Although the overall accuracy appears to be better in frozen specimens, somatic alterations were detected in DNA extracted from paraffin-embedded samples.

  17. Detection of somatic mutations by high-resolution DNA melting (HRM analysis in multiple cancers.

    Directory of Open Access Journals (Sweden)

    Jesus Gonzalez-Bosquet

    Full Text Available Identification of somatic mutations in cancer is a major goal for understanding and monitoring the events related to cancer initiation and progression. High resolution melting (HRM curve analysis represents a fast, post-PCR high-throughput method for scanning somatic sequence alterations in target genes. The aim of this study was to assess the sensitivity and specificity of HRM analysis for tumor mutation screening in a range of tumor samples, which included 216 frozen pediatric small rounded blue-cell tumors as well as 180 paraffin-embedded tumors from breast, endometrial and ovarian cancers (60 of each. HRM analysis was performed in exons of the following candidate genes known to harbor established commonly observed mutations: PIK3CA, ERBB2, KRAS, TP53, EGFR, BRAF, GATA3, and FGFR3. Bi-directional sequencing analysis was used to determine the accuracy of the HRM analysis. For the 39 mutations observed in frozen samples, the sensitivity and specificity of HRM analysis were 97% and 87%, respectively. There were 67 mutation/variants in the paraffin-embedded samples, and the sensitivity and specificity for the HRM analysis were 88% and 80%, respectively. Paraffin-embedded samples require higher quantity of purified DNA for high performance. In summary, HRM analysis is a promising moderate-throughput screening test for mutations among known candidate genomic regions. Although the overall accuracy appears to be better in frozen specimens, somatic alterations were detected in DNA extracted from paraffin-embedded samples.

  18. Identification of somatic mutations in postmortem human brains by whole genome sequencing and their implications for psychiatric disorders.

    Science.gov (United States)

    Nishioka, Masaki; Bundo, Miki; Ueda, Junko; Katsuoka, Fumiki; Sato, Yukuto; Kuroki, Yoko; Ishii, Takao; Ukai, Wataru; Murayama, Shigeo; Hashimoto, Eri; Nagasaki, Masao; Yasuda, Jun; Kasai, Kiyoto; Kato, Tadafumi; Iwamoto, Kazuya

    2018-04-01

    Somatic mutations in the human brain are hypothesized to contribute to the functional diversity of brain cells as well as the pathophysiology of neuropsychiatric diseases. However, there are still few reports on somatic mutations in non-neoplastic human brain tissues. This study attempted to unveil the landscape of somatic mutations in the human brain. We explored the landscape of somatic mutations in human brain tissues derived from three individuals with no neuropsychiatric diseases by whole-genome deep sequencing at a depth of around 100. The candidate mutations underwent multi-layered filtering, and were validated by ultra-deep target amplicon sequencing at a depth of around 200 000. Thirty-one somatic mutations were identified in the human brain, demonstrating the utility of whole-genome sequencing of bulk brain tissue. The mutations were enriched in neuron-expressed genes, and two-thirds of the identified somatic single nucleotide variants in the brain tissues were cytosine-to-thymine transitions, half of which were in CpG dinucleotides. Our developed filtering and validation approaches will be useful to identify somatic mutations in the human brain. The vulnerability of neuron-expressed genes to mutational events suggests their potential relevance to neuropsychiatric diseases. © 2017 The Authors. Psychiatry and Clinical Neurosciences published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Psychiatry and Neurology.

  19. 40 CFR 798.5300 - Detection of gene mutations in somatic cells in culture.

    Science.gov (United States)

    2010-07-01

    ... cells in culture. 798.5300 Section 798.5300 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY....5300 Detection of gene mutations in somatic cells in culture. (a) Purpose. Mammalian cell culture... selected by resistance to ouabain. (2) Description. Cells in suspension or monolayer culture are exposed to...

  20. MDS-associated somatic mutations and clonal hematopoiesis are common in idiopathic cytopenias of undetermined significance.

    Science.gov (United States)

    Kwok, Brian; Hall, Jeff M; Witte, John S; Xu, Yin; Reddy, Prashanti; Lin, Keming; Flamholz, Rachel; Dabbas, Bashar; Yung, Aine; Al-Hafidh, Jenan; Balmert, Emily; Vaupel, Christine; El Hader, Carlos; McGinniss, Matthew J; Nahas, Shareef A; Kines, Julie; Bejar, Rafael

    2015-11-19

    Establishing a diagnosis in patients suspected of having a myelodysplastic syndrome (MDS) can be challenging and could be informed by the identification of somatic mutations. We performed a prospective study to examine the frequency and types of mutations encountered in 144 patients with unexplained cytopenias. Based on bone marrow findings, 17% were diagnosed with MDS, 15% with idiopathic cytopenias of undetermined significance (ICUS) and some evidence of dysplasia, and 69% with ICUS and no dysplasia. Bone marrow DNA was sequenced for mutations in 22 frequently mutated myeloid malignancy genes. Somatic mutations were identified in 71% of MDS patients, 62% of patients with ICUS and some dysplasia, and 20% of ICUS patients and no dysplasia. In total, 35% of ICUS patients carried a somatic mutation or chromosomal abnormality indicative of clonal hematopoiesis. We validated these results in a cohort of 91 lower-risk MDS and 249 ICUS cases identified over a 6-month interval. Mutations were found in 79% of those with MDS, in 45% of those with ICUS with dysplasia, and in 17% of those with ICUS without dysplasia. The spectrum of mutated genes was similar with the exception of SF3B1 which was rarely mutated in patients without dysplasia. Variant allele fractions were comparable between clonal ICUS (CCUS) and MDS as were mean age and blood counts. We demonstrate that CCUS is a more frequent diagnosis than MDS in cytopenic patients. Clinical and mutational features are similar in these groups and may have diagnostic utility once outcomes in CCUS patients are better understood. © 2015 by The American Society of Hematology.

  1. Factors affecting the spontaneous mutational spectra in somatic mammalian cells

    Directory of Open Access Journals (Sweden)

    О.А. Ковальова

    2006-04-01

    Full Text Available  In our survey of references we are discussed the influence of factors biological origin on the spontaneous mutation specters in mammalian. Seasonal and age components influence on the frequence of cytogenetic anomalies. The immune and endocrinous systems are take part in control of the alteration of the spontaneous mutation specters. Genetical difference of sensibility in animal and human at the alteration of factors enviroment as and  genetical differences of repair systems activity are may influence on individual variation of spontaneous destabilization characters of chromosomal apparatus.

  2. Sun exposure causes somatic second-hit mutations and angiofibroma development in tuberous sclerosis complex

    Science.gov (United States)

    Tyburczy, Magdalena E.; Wang, Ji-an; Li, Shaowei; Thangapazham, Rajesh; Chekaluk, Yvonne; Moss, Joel; Kwiatkowski, David J.; Darling, Thomas N.

    2014-01-01

    Tuberous sclerosis complex (TSC) is characterized by the formation of tumors in multiple organs and is caused by germline mutation in one of two tumor suppressor genes, TSC1 and TSC2. As for other tumor suppressor gene syndromes, the mechanism of somatic second-hit events in TSC tumors is unknown. We grew fibroblast-like cells from 29 TSC skin tumors from 22 TSC subjects and identified germline and second-hit mutations in TSC1/TSC2 using next-generation sequencing. Eighteen of 22 (82%) subjects had a mutation identified, and 8 of the 18 (44%) subjects were mosaic with mutant allele frequencies of 0 to 19% in normal tissue DNA. Multiple tumors were available from four patients, and in each case, second-hit mutations in TSC2 were distinct indicating they arose independently. Most remarkably, 7 (50%) of the 14 somatic point mutations were CC>TT ultraviolet ‘signature’ mutations, never seen as a TSC germline mutation. These occurred exclusively in facial angiofibroma tumors from sun-exposed sites. These results implicate UV-induced DNA damage as a cause of second-hit mutations and development of TSC facial angiofibromas and suggest that measures to limit UV exposure in TSC children and adults should reduce the frequency and severity of these lesions. PMID:24271014

  3. Exome sequencing identifies highly recurrent MED12 somatic mutations in breast fibroadenoma.

    Science.gov (United States)

    Lim, Weng Khong; Ong, Choon Kiat; Tan, Jing; Thike, Aye Aye; Ng, Cedric Chuan Young; Rajasegaran, Vikneswari; Myint, Swe Swe; Nagarajan, Sanjanaa; Nasir, Nur Diyana Md; McPherson, John R; Cutcutache, Ioana; Poore, Gregory; Tay, Su Ting; Ooi, Wei Siong; Tan, Veronique Kiak Mien; Hartman, Mikael; Ong, Kong Wee; Tan, Benita K T; Rozen, Steven G; Tan, Puay Hoon; Tan, Patrick; Teh, Bin Tean

    2014-08-01

    Fibroadenomas are the most common breast tumors in women under 30 (refs. 1,2). Exome sequencing of eight fibroadenomas with matching whole-blood samples revealed recurrent somatic mutations solely in MED12, which encodes a Mediator complex subunit. Targeted sequencing of an additional 90 fibroadenomas confirmed highly frequent MED12 exon 2 mutations (58/98, 59%) that are probably somatic, with 71% of mutations occurring in codon 44. Using laser capture microdissection, we show that MED12 fibroadenoma mutations are present in stromal but not epithelial mammary cells. Expression profiling of MED12-mutated and wild-type fibroadenomas revealed that MED12 mutations are associated with dysregulated estrogen signaling and extracellular matrix organization. The fibroadenoma MED12 mutation spectrum is nearly identical to that of previously reported MED12 lesions in uterine leiomyoma but not those of other tumors. Benign tumors of the breast and uterus, both of which are key target tissues of estrogen, may thus share a common genetic basis underpinned by highly frequent and specific MED12 mutations.

  4. Polycythemia and paraganglioma with a novel somatic HIF2A mutation in a male.

    Science.gov (United States)

    Toyoda, Hidemi; Hirayama, Jyunya; Sugimoto, Yuka; Uchida, Keiichi; Ohishi, Kohshi; Hirayama, Masahiro; Komada, Yoshihiro

    2014-06-01

    Recently, a new syndrome of paraganglioma, somatostatinoma, and polycythemia has been discovered (known as Pacak-Zhuang syndrome). This new syndrome, with somatic HIF2A gain-of-function mutations, has never been reported in male patients. We describe a male patient with Pacak-Zhuang syndrome who carries a newly discovered HIF2A mutation. Congenital polycythemias have diverse etiologies, including germline mutations in the oxygen-sensing pathway. These include von Hippel-Lindau (Chuvash polycythemia), prolyl hydroxylase domain-containing protein-2, and hypoxia-inducible factor-2α (HIF-2α). Somatic gain-of-function mutations in the gene encoding HIF-2α were reported in patients with paraganglioma and polycythemia and have been found exclusively in female patients. Through sequencing of the HIF2A using DNA from paraganglioma in 15-year-old male patient, we identified a novel mutation of HIF2A: a heterozygous C to A substitution at base 1589 in exon 12 of HIF2A. The mutation was not found in germline DNA from leukocytes. The C1589A mutations resulted in substitution of alanine 530 in the HIF-2α protein with glutamic acid. This mutation is undoubtedly associated with increased HIF-2α activity and increased protein half-life, because it affects the vicinity of the prolyl hydroxylase target residue, proline 531. To our knowledge, this is the first report describing Pacak-Zhuang syndrome with somatic gain-of-function mutation in HIF2A in a male patient. Congenital polycythemia of unknown origin should raise suspicion for the novel disorder Pacak-Zhuang syndrome, even in male patients. Copyright © 2014 by the American Academy of Pediatrics.

  5. Variation of mutational burden in healthy human tissues suggests non-random strand segregation and allows measuring somatic mutation rates.

    Science.gov (United States)

    Werner, Benjamin; Sottoriva, Andrea

    2018-06-01

    The immortal strand hypothesis poses that stem cells could produce differentiated progeny while conserving the original template strand, thus avoiding accumulating somatic mutations. However, quantitating the extent of non-random DNA strand segregation in human stem cells remains difficult in vivo. Here we show that the change of the mean and variance of the mutational burden with age in healthy human tissues allows estimating strand segregation probabilities and somatic mutation rates. We analysed deep sequencing data from healthy human colon, small intestine, liver, skin and brain. We found highly effective non-random DNA strand segregation in all adult tissues (mean strand segregation probability: 0.98, standard error bounds (0.97,0.99)). In contrast, non-random strand segregation efficiency is reduced to 0.87 (0.78,0.88) in neural tissue during early development, suggesting stem cell pool expansions due to symmetric self-renewal. Healthy somatic mutation rates differed across tissue types, ranging from 3.5 × 10-9/bp/division in small intestine to 1.6 × 10-7/bp/division in skin.

  6. Variation of mutational burden in healthy human tissues suggests non-random strand segregation and allows measuring somatic mutation rates.

    Directory of Open Access Journals (Sweden)

    Benjamin Werner

    2018-06-01

    Full Text Available The immortal strand hypothesis poses that stem cells could produce differentiated progeny while conserving the original template strand, thus avoiding accumulating somatic mutations. However, quantitating the extent of non-random DNA strand segregation in human stem cells remains difficult in vivo. Here we show that the change of the mean and variance of the mutational burden with age in healthy human tissues allows estimating strand segregation probabilities and somatic mutation rates. We analysed deep sequencing data from healthy human colon, small intestine, liver, skin and brain. We found highly effective non-random DNA strand segregation in all adult tissues (mean strand segregation probability: 0.98, standard error bounds (0.97,0.99. In contrast, non-random strand segregation efficiency is reduced to 0.87 (0.78,0.88 in neural tissue during early development, suggesting stem cell pool expansions due to symmetric self-renewal. Healthy somatic mutation rates differed across tissue types, ranging from 3.5 × 10-9/bp/division in small intestine to 1.6 × 10-7/bp/division in skin.

  7. Oncogenetic tree model of somatic mutations and DNA methylation in colon tumors.

    Science.gov (United States)

    Sweeney, Carol; Boucher, Kenneth M; Samowitz, Wade S; Wolff, Roger K; Albertsen, Hans; Curtin, Karen; Caan, Bette J; Slattery, Martha L

    2009-01-01

    Our understanding of somatic alterations in colon cancer has evolved from a concept of a series of events taking place in a single sequence to a recognition of multiple pathways. An oncogenetic tree is a model intended to describe the pathways and sequence of somatic alterations in carcinogenesis without assuming that tumors will fall in mutually exclusive categories. We applied this model to data on colon tumor somatic alterations. An oncogenetic tree model was built using data on mutations of TP53, KRAS2, APC, and BRAF genes, methylation at CpG sites of MLH1 and TP16 genes, methylation in tumor (MINT) markers, and microsatellite instability (MSI) for 971 colon tumors from a population-based series. Oncogenetic tree analysis resulted in a reproducible tree with three branches. The model represents methylation of MINT markers as initiating a branch and predisposing to MSI, methylation of MHL1 and TP16, and BRAF mutation. APC mutation is the first alteration in an independent branch and is followed by TP53 mutation. KRAS2 mutation was placed a third independent branch, implying that it neither depends on, nor predisposes to, the other alterations. Individual tumors were observed to have alteration patterns representing every combination of one, two, or all three branches. The oncogenetic tree model assumptions are appropriate for the observed heterogeneity of colon tumors, and the model produces a useful visual schematic of the sequence of events in pathways of colon carcinogenesis.

  8. Flow-cytometric measurements of somatic cell mutations in Thorotrast patients

    International Nuclear Information System (INIS)

    Umeki, Shigeko; Kyoizumi, Seishi; Kusunoki, Yoichiro; Nakamura, Nori; Sasaki, Masao; Mori, Takesaburo; Ishikawa, Yuichi; Cologne, J.B.; Akiyama, Mitoshi.

    1992-10-01

    Exposure to ionizing radiation is a well-recognized risk factor for cancer development. Because ionizing radiation can induce mutations, an accurate way of measuring somatic mutation frequencies could be a useful tool for evaluating cancer risk. In the present study, we have examined in vivo somatic mutation frequencies at the erythrocyte glycophorin A and T-cell receptor loci in 18 Thorotrast patients. These persons have been continuously irradiated with alpha particles emitted from the internal deposition of thorium dioxide and thus have increased risks of certain malignant tumors. When compared with controls, the Thorotrast patients showed a significantly higher frequency of mutants at the lymphocyte T-cell receptor loci but not at the erythrocyte glycophorin A loci. (author)

  9. Somatic mutations in the transcriptional corepressor gene BCORL1 in adult acute myelogenous leukemia

    OpenAIRE

    Li, Meng; Collins, Roxane; Jiao, Yuchen; Ouillette, Peter; Bixby, Dale; Erba, Harry; Vogelstein, Bert; Kinzler, Kenneth W.; Papadopoulos, Nickolas; Malek, Sami N.

    2011-01-01

    To further our understanding of the genetic basis of acute myelogenous leukemia (AML), we determined the coding exon sequences of ∼ 18 000 protein-encoding genes in 8 patients with secondary AML. Here we report the discovery of novel somatic mutations in the transcriptional corepressor gene BCORL1 that is located on the X-chromosome. Analysis of BCORL1 in an unselected cohort of 173 AML patients identified a total of 10 mutated cases (6%) with BCORL1 mutations, whereas analysis of 19 AML cell...

  10. Identification of somatic mutations in cancer through Bayesian-based analysis of sequenced genome pairs.

    Science.gov (United States)

    Christoforides, Alexis; Carpten, John D; Weiss, Glen J; Demeure, Michael J; Von Hoff, Daniel D; Craig, David W

    2013-05-04

    The field of cancer genomics has rapidly adopted next-generation sequencing (NGS) in order to study and characterize malignant tumors with unprecedented resolution. In particular for cancer, one is often trying to identify somatic mutations--changes specific to a tumor and not within an individual's germline. However, false positive and false negative detections often result from lack of sufficient variant evidence, contamination of the biopsy by stromal tissue, sequencing errors, and the erroneous classification of germline variation as tumor-specific. We have developed a generalized Bayesian analysis framework for matched tumor/normal samples with the purpose of identifying tumor-specific alterations such as single nucleotide mutations, small insertions/deletions, and structural variation. We describe our methodology, and discuss its application to other types of paired-tissue analysis such as the detection of loss of heterozygosity as well as allelic imbalance. We also demonstrate the high level of sensitivity and specificity in discovering simulated somatic mutations, for various combinations of a) genomic coverage and b) emulated heterogeneity. We present a Java-based implementation of our methods named Seurat, which is made available for free academic use. We have demonstrated and reported on the discovery of different types of somatic change by applying Seurat to an experimentally-derived cancer dataset using our methods; and have discussed considerations and practices regarding the accurate detection of somatic events in cancer genomes. Seurat is available at https://sites.google.com/site/seuratsomatic.

  11. Suppression of different classes of somatic mutations in Arabidopsis by vir gene-expressing Agrobacterium strains.

    Science.gov (United States)

    Shah, Jasmine M; Ramakrishnan, Anantha Maharasi; Singh, Amit Kumar; Ramachandran, Subalakshmi; Unniyampurath, Unnikrishnan; Jayshankar, Ajitha; Balasundaram, Nithya; Dhanapal, Shanmuhapreya; Hyde, Geoff; Baskar, Ramamurthy

    2015-08-26

    Agrobacterium infection, which is widely used to generate transgenic plants, is often accompanied by T-DNA-linked mutations and transpositions in flowering plants. It is not known if Agrobacterium infection also affects the rates of point mutations, somatic homologous recombinations (SHR) and frame-shift mutations (FSM). We examined the effects of Agrobacterium infection on five types of somatic mutations using a set of mutation detector lines of Arabidopsis thaliana. To verify the effect of secreted factors, we exposed the plants to different Agrobacterium strains, including wild type (Ach5), its derivatives lacking vir genes, oncogenes or T-DNA, and the heat-killed form for 48 h post-infection; also, for a smaller set of strains, we examined the rates of three types of mutations at multiple time-points. The mutation detector lines carried a non-functional β-glucuronidase gene (GUS) and a reversion of mutated GUS to its functional form resulted in blue spots. Based on the number of blue spots visible in plants grown for a further two weeks, we estimated the mutation frequencies. For plants co-cultivated for 48 h with Agrobacterium, if the strain contained vir genes, then the rates of transversions, SHRs and FSMs (measured 2 weeks later) were lower than those of uninfected controls. In contrast, co-cultivation for 48 h with any of the Agrobacterium strains raised the transposition rates above control levels. The multiple time-point study showed that in seedlings co-cultivated with wild type Ach5, the reduced rates of transversions and SHRs after 48 h co-cultivation represent an apparent suppression of an earlier short-lived increase in mutation rates (peaking for plants co-cultivated for 3 h). An increase after 3 h co-cultivation was also seen for rates of transversions (but not SHR) in seedlings exposed to the strain lacking vir genes, oncogenes and T-DNA. However, the mutation rates in plants co-cultivated for longer times with this strain subsequently

  12. Mutational analysis of EGFR and related signaling pathway genes in lung adenocarcinomas identifies a novel somatic kinase domain mutation in FGFR4.

    Directory of Open Access Journals (Sweden)

    Jenifer L Marks

    2007-05-01

    Full Text Available Fifty percent of lung adenocarcinomas harbor somatic mutations in six genes that encode proteins in the EGFR signaling pathway, i.e., EGFR, HER2/ERBB2, HER4/ERBB4, PIK3CA, BRAF, and KRAS. We performed mutational profiling of a large cohort of lung adenocarcinomas to uncover other potential somatic mutations in genes of this signaling pathway that could contribute to lung tumorigenesis.We analyzed genomic DNA from a total of 261 resected, clinically annotated non-small cell lung cancer (NSCLC specimens. The coding sequences of 39 genes were screened for somatic mutations via high-throughput dideoxynucleotide sequencing of PCR-amplified gene products. Mutations were considered to be somatic only if they were found in an independent tumor-derived PCR product but not in matched normal tissue. Sequencing of 9MB of tumor sequence identified 239 putative genetic variants. We further examined 22 variants found in RAS family genes and 135 variants localized to exons encoding the kinase domain of respective proteins. We identified a total of 37 non-synonymous somatic mutations; 36 were found collectively in EGFR, KRAS, BRAF, and PIK3CA. One somatic mutation was a previously unreported mutation in the kinase domain (exon 16 of FGFR4 (Glu681Lys, identified in 1 of 158 tumors. The FGFR4 mutation is analogous to a reported tumor-specific somatic mutation in ERBB2 and is located in the same exon as a previously reported kinase domain mutation in FGFR4 (Pro712Thr in a lung adenocarcinoma cell line.This study is one of the first comprehensive mutational analyses of major genes in a specific signaling pathway in a sizeable cohort of lung adenocarcinomas. Our results suggest the majority of gain-of-function mutations within kinase genes in the EGFR signaling pathway have already been identified. Our findings also implicate FGFR4 in the pathogenesis of a subset of lung adenocarcinomas.

  13. Novel homozygous FANCL mutation and somatic heterozygous SETBP1 mutation in a Chinese girl with Fanconi Anemia.

    Science.gov (United States)

    Wu, Weiqing; Liu, Yang; Zhou, Qinghua; Wang, Qin; Luo, Fuwei; Xu, Zhiyong; Geng, Qian; Li, Peining; Zhang, Hui Z; Xie, Jiansheng

    2017-07-01

    Fanconi Anemia (FA) is a rare genetically heterogeneous disorder with 17 known complement groups caused by mutations in different genes. FA complementation group L (FA-L, OMIM #608111) occurred in 0.2% of all FA and only eight mutant variants in the FANCL gene were documented. Phenotype and genotype correlation in FANCL associated FA is still obscure. Here we describe a Chinese girl with FA-L caused by a novel homozygous mutation c.822_823insCTTTCAGG (p.Asp275LeufsX13) in the FANCL gene. The patient's clinical course was typical for FA with progression to bone marrow failure, and death from acute myelomonocytic leukemia (AML-M4) at 9 years of age. Mutation analysis also detected a likely somatic c.2608G > A (p.Gly870Ser) in the SETBP1 gene. Consistent copy number losses of 7q and 18p and gains of 3q and 21q and accumulated non-clonal single cell chromosomal abnormalities were detected in blood leukocytes as her FA progressed. This is the first Chinese FA-L case caused by a novel FANCL mutation. The somatic gene mutation and copy number aberrations could be used to monitor disease progression and the clinical findings provide further information for genotype-phenotype correlation for FA-L. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. Somatic Mutational Landscape of Splicing Factor Genes and Their Functional Consequences across 33 Cancer Types

    Directory of Open Access Journals (Sweden)

    Michael Seiler

    2018-04-01

    Full Text Available Summary: Hotspot mutations in splicing factor genes have been recently reported at high frequency in hematological malignancies, suggesting the importance of RNA splicing in cancer. We analyzed whole-exome sequencing data across 33 tumor types in The Cancer Genome Atlas (TCGA, and we identified 119 splicing factor genes with significant non-silent mutation patterns, including mutation over-representation, recurrent loss of function (tumor suppressor-like, or hotspot mutation profile (oncogene-like. Furthermore, RNA sequencing analysis revealed altered splicing events associated with selected splicing factor mutations. In addition, we were able to identify common gene pathway profiles associated with the presence of these mutations. Our analysis suggests that somatic alteration of genes involved in the RNA-splicing process is common in cancer and may represent an underappreciated hallmark of tumorigenesis. : Seiler et al. report that 119 splicing factor genes carry putative driver mutations over 33 tumor types in TCGA. The most common mutations appear to be mutually exclusive and are associated with lineage-independent altered splicing. Samples with these mutations show deregulation of cell-autonomous pathways and immune infiltration. Keywords: splicing, SF3B1, U2AF1, SRSF2, RBM10, FUBP1, cancer, mutation

  15. Somatic mutation analysis of MYH11 in breast and prostate cancer

    International Nuclear Information System (INIS)

    Alhopuro, Pia; Karhu, Auli; Winqvist, Robert; Waltering, Kati; Visakorpi, Tapio; Aaltonen, Lauri A

    2008-01-01

    MYH11 (also known as SMMHC) encodes the smooth-muscle myosin heavy chain, which has a key role in smooth muscle contraction. Inversion at the MYH11 locus is one of the most frequent chromosomal aberrations found in acute myeloid leukemia. We have previously shown that MYH11 mutations occur in human colorectal cancer, and may also be associated with Peutz-Jeghers syndrome. The mutations found in human intestinal neoplasia result in unregulated proteins with constitutive motor activity, similar to the mutant myh11 underlying the zebrafish meltdown phenotype characterized by disrupted intestinal architecture. Recently, MYH1 and MYH9 have been identified as candidate breast cancer genes in a systematic analysis of the breast cancer genome. The aim of this study was to investigate the role of somatic MYH11 mutations in two common tumor types; breast and prostate cancers. A total of 155 breast cancer and 71 prostate cancer samples were analyzed for those regions in MYH11 (altogether 8 exons out of 42 coding exons) that harboured mutations in colorectal cancer in our previous study. In breast cancer samples only germline alterations were observed. One prostate cancer sample harbored a frameshift mutation c.5798delC, which we have previously shown to result in a protein with unregulated motor activity. Little evidence for a role of somatic MYH11 mutations in the formation of breast or prostate cancers was obtained in this study

  16. Somatic mutations in breast and serous ovarian cancer young patients: a systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Giselly Encinas

    2015-10-01

    Full Text Available Summary Objective: our aim was to evaluate whether somatic mutations in five genes were associated with an early age at presentation of breast cancer (BC or serous ovarian cancer (SOC. Methods: COSMIC database was searched for the five most frequent somatic mutations in BC and SOC. A systematic review of PubMed was performed. Young age for BC and SOC patients was set at ≤35 and ≤40 years, respectively. Age groups were also classified in <30years and every 10 years thereafter. Results: twenty six (1,980 patients, 111 younger and 16 studies (598, 41 younger, were analyzed for BC and SOC, respectively. In BC, PIK3CA wild type tumor was associated with early onset, not confirmed in binary regression with estrogen receptor (ER status. In HER2-negative tumors, there was increased frequency of PIK3CA somatic mutation in older age groups; in ER-positive tumors, there was a trend towards an increased frequency of PIK3CA somatic mutation in older age groups. TP53 somatic mutation was described in 20% of tumors from both younger and older patients; PTEN, CDH1 and GATA3 somatic mutation was investigated only in 16 patients and PTEN mutation was detected in one of them. In SOC, TP53 somatic mutation was rather common, detected in more than 50% of tumors, however, more frequently in older patients. Conclusion: frequency of somatic mutations in specific genes was not associated with early-onset breast cancer. Although very common in patients with serous ovarian cancer diagnosed at all ages, TP53 mutation was more frequently detected in older women.

  17. Somatic mutations in Tradescantia as a model system for studying the effects of the environmental agents

    International Nuclear Information System (INIS)

    Cebulska-Wasilewska, A.

    1986-01-01

    The application of the plant model system for studying the biological effects of ionizing radiation and chemical mutagens is presented. The model system is based on the somatic mutation frequency in stamen hair cells of Tradescantia clones heterosygous for flower color. The interaction of chemical mutagens with radiation in the induction of somatic mutations was investigated. The results demonstrate the synergistic interaction between radiation and chemical mutagens like ethyl methanesulfonate and di-bromoethane. The synergistic effect is clearly manifested after combined treatment with radiation and chemicals. In the low dose region the effect depends on the radiation dose and chemical exposure. Other results show the influence of the fluoride treatment on the radiation effect. The fluoride treatment is likely to alter the DNA double strand breaks repair processes. Additionally the usefulness of the model system for studying the mutagenic effectiveness of the pollution in the ambient air is presented. 148 refs. (author)

  18. Novel Secondary Somatic Mutations in Ewing's Sarcoma and Desmoplastic Small Round Cell Tumors

    Science.gov (United States)

    Janku, Filip; Ludwig, Joseph A.; Naing, Aung; Benjamin, Robert S.; Brown, Robert E.; Anderson, Pete; Kurzrock, Razelle

    2014-01-01

    Background Ewing's sarcoma (ES) and desmoplastic small round cell tumors (DSRCT) are small round blue cell tumors driven by an N-terminal containing EWS translocation. Very few somatic mutations have been reported in ES, and none have been identified in DSRCT. The aim of this study is to explore potential actionable mutations in ES and DSRCT. Methodology Twenty eight patients with ES or DSRCT had tumor tissue available that could be analyzed by one of the following methods: 1) Next-generation exome sequencing platform; 2) Multiplex PCR/Mass Spectroscopy; 3) Polymerase chain reaction (PCR)-based single- gene mutation screening; 4) Sanger sequencing; 5) Morphoproteomics. Principal Findings Novel somatic mutations were identified in four out of 18 patients with advanced ES and two of 10 patients with advanced DSRCT (six out of 28 (21.4%));KRAS (n = 1), PTPRD (n = 1), GRB10 (n = 2), MET (n = 2) and PIK3CA (n = 1). One patient with both PTPRD and GRB10 mutations and one with a GRB10 mutation achieved a complete remission (CR) on an Insulin like growth factor 1 receptor (IGF1R) inhibitor based treatment. One patient, who achieved a partial remission (PR) with IGF1R inhibitor treatment, but later developed resistance, demonstrated a KRAS mutation in the post-treatment resistant tumor, but not in the pre-treatment tumor suggesting that the RAF/RAS/MEK pathway was activated with progression. Conclusions We have reported several different mutations in advanced ES and DSRCT that have direct implications for molecularly-directed targeted therapy. Our technology agnostic approach provides an initial mutational roadmap used in the path towards individualized combination therapy. PMID:25119929

  19. Induction of somatic mutations in ornamental plants by ionizing radiations and chemical mutagens

    International Nuclear Information System (INIS)

    Desai, B.M.; Abraham, V.

    1980-01-01

    Improvement in some ornamental plants through induction of somatic mutations by ionizing radiations and chemical mutagens viz. colchicine, EMS and DS has been attempted. Mutants of high ornamental value have been evolved, isolated and multiplied in canna, perennial portulaca, tuberose, bougainvillea, hibiscus, daisy, lilies. These pertain to changes in colour, shape and size of flower and foliage. Procedural details on induction, isolation, stabilisation of the mutants and description of the new characteristics are presented. (author)

  20. Survey on the frequency of somatic mutations in A-bomb survivors

    International Nuclear Information System (INIS)

    Akiyama, Mitoshi

    1992-01-01

    Several methods have recently been established for quantitatively detecting somatic cell mutations on a specific locus using human blood cells. These methods have enabled the biological estimation of A-bomb radiation doses in surveys on somatic cell mutations. This paper outlines HPRT, GPA, and TCR assays used to measure somatic cell mutations, focusing on the outcome in A-bomb survivors. HPRT assay is based on colony formation with interleukin-2. The frequency of HPRT mutant cells was significantly increased with advancing age in A-bomb survivors and was positively correlated with the frequency of chromosomal aberrations in lymphocytes. There was also a significantly positive correlation between HPRT mutant cell frequencies and DS86 estimated doses, although the slope was slow. In GPA assay, flow cytometric measurements of fluorescence-labeled erythrocytes are used to detect somatic cell mutations. There was a positive correlation between GPA mutant cell frequencies and age in A-bomb survivors. The GPA mutant cell frequencies showed much more positive correlation with lymphocyte chromosomal aberration frequencies than the HPRT mutant cell frequencies. When anti-CD3 antibody and anti-CD4 antibody are labeled with different fluorescences and are analyzed by using flow cytometry, TCR mutant cells having CD3 - 4 + can be detected. When the frequency of TCR mutant cells was examined in 342 A-bomb survivors, it did not correlate with radiation doses. This implies that TCR assay may be unadequate for biological estimation of A-bomb radiation doses throughout a lifetime of A-bomb survivors, because TCR mutant cells seems to be unable to live for a long time due to national selection. (N.K.)

  1. Screening for acyanogenic somatic mutations in cassava (Manihot esculenta Crantz)

    International Nuclear Information System (INIS)

    Moh, C.C.

    1976-01-01

    By irradiating the young stem cuttings (6-8 months old wood) of a cassava cultivar, Japonesa, (Manihot esculenta Crantz) with an acute dose of 4 kR from a 60 CO source, it was found that in a number of cases, the induced mutant characters appeared in the whole R 1 plants or in large chimeric sectors. This result suggested that a cassava plant could develop from one or two initial cells in the shoot apex of a bud. This unusual biological response to radiation provides a great advantage for selection in mutation breeding. By using the sodium picrate method, 2676 leaves from 1338 R 1 plants irradiated with 4 kR were screened for hydrocyanic acid content (HCN). As compared with the control, some leaves had higher and some had lower HCN level, indicating that the radiation broadened the variability. Whether or not those R 1 plants producing a lower level of HCN in the leaves are truly a genetic mutant cannot be ascertained at present. Further screening of the selected R 1 plants in the subsequent vegetative propagation generations will help to distinguish whether they are genetic mutants. (author)

  2. Somatic mitochondrial DNA mutations in cancer escape purifying selection and high pathogenicity mutations lead to the oncocytic phenotype: pathogenicity analysis of reported somatic mtDNA mutations in tumors

    International Nuclear Information System (INIS)

    Pereira, Luísa; Soares, Pedro; Máximo, Valdemar; Samuels, David C

    2012-01-01

    The presence of somatic mitochondrial DNA (mtDNA) mutations in cancer cells has been interpreted in controversial ways, ranging from random neutral accumulation of mutations, to positive selection for high pathogenicity, or conversely to purifying selection against high pathogenicity variants as occurs at the population level. Here we evaluated the predicted pathogenicity of somatic mtDNA mutations described in cancer and compare these to the distribution of variations observed in the global human population and all possible protein variations that could occur in human mtDNA. We focus on oncocytic tumors, which are clearly associated with mitochondrial dysfunction. The protein variant pathogenicity was predicted using two computational methods, MutPred and SNPs&GO. The pathogenicity score of the somatic mtDNA variants were significantly higher in oncocytic tumors compared to non-oncocytic tumors. Variations in subunits of Complex I of the electron transfer chain were significantly more common in tumors with the oncocytic phenotype, while variations in Complex V subunits were significantly more common in non-oncocytic tumors. Our results show that the somatic mtDNA mutations reported over all tumors are indistinguishable from a random selection from the set of all possible amino acid variations, and have therefore escaped the effects of purifying selection that act strongly at the population level. We show that the pathogenicity of somatic mtDNA mutations is a determining factor for the oncocytic phenotype. The opposite associations of the Complex I and Complex V variants with the oncocytic and non-oncocytic tumors implies that low mitochondrial membrane potential may play an important role in determining the oncocytic phenotype

  3. Comprehensive genomic profiling reveals inactivating SMARCA4 mutations and low tumor mutational burden in small cell carcinoma of the ovary, hypercalcemic-type.

    Science.gov (United States)

    Lin, Douglas I; Chudnovsky, Yakov; Duggan, Bridget; Zajchowski, Deborah; Greenbowe, Joel; Ross, Jeffrey S; Gay, Laurie M; Ali, Siraj M; Elvin, Julia A

    2017-12-01

    Small cell carcinoma of the ovary, hypercalcemic-type (SCCOHT) is a rare, extremely aggressive neoplasm that usually occurs in young women and is characterized by deleterious germline or somatic SMARCA4 mutations. We performed comprehensive genomic profiling (CGP) to potentially identify additional clinically and pathophysiologically relevant genomic alterations in SCCOHT. CGP assessment of all classes of coding alterations in up to 406 genes commonly altered in cancer and intronic regions for up to 31 genes commonly rearranged in cancer was performed on 18 SCCOHT cases (16 exhibiting classic morphology and 2 cases exhibiting exclusive a large cell variant morphology). In addition, a retrospective database search for clinically advanced ovarian tumors with genomic profiles similar to SCCOHT yielded 3 additional cases originally diagnosed as non-SCCOHT. CGP revealed inactivating SMARCA4 alterations and low tumor mutational burden (TMB) (<6mutations/Mb) in 94% (15/16) of SCCOHT with classic morphology. In contrast, both (2/2) cases exhibiting only large cell variant morphology were hypermutated (TMB scores of 90 and 360mut/Mb) and were wildtype for SMARCA4. In our retrospective search, an index ovarian cancer patient harboring inactivating SMARCA4 alterations, initially diagnosed as endometrioid carcinoma, was re-classified as SCCOHT and responded to an SCCOHT chemotherapy regimen. The vast majority of SCCOHT demonstrate genomic SMARCA4 loss with only rare co-occurring alterations. Our data support a role for CGP in the diagnosis and management of SCCOHT and of other lesions with overlapping histological and clinical features, since identifying the former by genomic profile suggests benefit from an appropriate regimen and treatment decisions, as illustrated by an index patient. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Effects of track structure and cell inactivation on the calculation of heavy ion mutation rates in mammalian cells

    Science.gov (United States)

    Cucinotta, F. A.; Wilson, J. W.; Shavers, M. R.; Katz, R.

    1996-01-01

    It has long been suggested that inactivation severely effects the probability of mutation by heavy ions in mammalian cells. Heavy ions have observed cross sections of inactivation that approach and sometimes exceed the geometric size of the cell nucleus in mammalian cells. In the track structure model of Katz the inactivation cross section is found by summing an inactivation probability over all impact parameters from the ion to the sensitive sites within the cell nucleus. The inactivation probability is evaluated using the dose-response of the system to gamma-rays and the radial dose of the ions and may be equal to unity at small impact parameters for some ions. We show how the effects of inactivation may be taken into account in the evaluation of the mutation cross sections from heavy ions in the track structure model through correlation of sites for gene mutation and cell inactivation. The model is fit to available data for HPRT mutations in Chinese hamster cells and good agreement is found. The resulting calculations qualitatively show that mutation cross sections for heavy ions display minima at velocities where inactivation cross sections display maxima. Also, calculations show the high probability of mutation by relativistic heavy ions due to the radial extension of ions track from delta-rays in agreement with the microlesion concept. The effects of inactivation on mutations rates make it very unlikely that a single parameter such as LET or Z*2/beta(2) can be used to specify radiation quality for heavy ion bombardment.

  5. Targeted disruption of Ataxia-telangiectasia mutated gene in miniature pigs by somatic cell nuclear transfer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young June; Ahn, Kwang Sung; Kim, Minjeong; Kim, Min Ju; Park, Sang-Min; Ryu, Junghyun; Ahn, Jin Seop; Heo, Soon Young; Kang, Jee Hyun; Choi, You Jung [Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan (Korea, Republic of); Choi, Seong-Jun [Institute of Tissue Regeneration Engineering, Dankook University, Cheonan (Korea, Republic of); Shim, Hosup, E-mail: shim@dku.edu [Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan (Korea, Republic of); Institute of Tissue Regeneration Engineering, Dankook University, Cheonan (Korea, Republic of); Department of Physiology, Dankook University School of Medicine, Cheonan (Korea, Republic of)

    2014-10-03

    Highlights: • ATM gene-targeted pigs were produced by somatic cell nuclear transfer. • A novel large animal model for ataxia telangiectasia was developed. • The new model may provide an alternative to the mouse model. - Abstract: Ataxia telangiectasia (A-T) is a recessive autosomal disorder associated with pleiotropic phenotypes, including progressive cerebellar degeneration, gonad atrophy, and growth retardation. Even though A-T is known to be caused by the mutations in the Ataxia telangiectasia mutated (ATM) gene, the correlation between abnormal cellular physiology caused by ATM mutations and the multiple symptoms of A-T disease has not been clearly determined. None of the existing ATM mouse models properly reflects the extent to which neurological degeneration occurs in human. In an attempt to provide a large animal model for A-T, we produced gene-targeted pigs with mutations in the ATM gene by somatic cell nuclear transfer. The disrupted allele in the ATM gene of cloned piglets was confirmed via PCR and Southern blot analysis. The ATM gene-targeted pigs generated in the present study may provide an alternative to the current mouse model for the study of mechanisms underlying A-T disorder and for the development of new therapies.

  6. Targeted disruption of Ataxia-telangiectasia mutated gene in miniature pigs by somatic cell nuclear transfer

    International Nuclear Information System (INIS)

    Kim, Young June; Ahn, Kwang Sung; Kim, Minjeong; Kim, Min Ju; Park, Sang-Min; Ryu, Junghyun; Ahn, Jin Seop; Heo, Soon Young; Kang, Jee Hyun; Choi, You Jung; Choi, Seong-Jun; Shim, Hosup

    2014-01-01

    Highlights: • ATM gene-targeted pigs were produced by somatic cell nuclear transfer. • A novel large animal model for ataxia telangiectasia was developed. • The new model may provide an alternative to the mouse model. - Abstract: Ataxia telangiectasia (A-T) is a recessive autosomal disorder associated with pleiotropic phenotypes, including progressive cerebellar degeneration, gonad atrophy, and growth retardation. Even though A-T is known to be caused by the mutations in the Ataxia telangiectasia mutated (ATM) gene, the correlation between abnormal cellular physiology caused by ATM mutations and the multiple symptoms of A-T disease has not been clearly determined. None of the existing ATM mouse models properly reflects the extent to which neurological degeneration occurs in human. In an attempt to provide a large animal model for A-T, we produced gene-targeted pigs with mutations in the ATM gene by somatic cell nuclear transfer. The disrupted allele in the ATM gene of cloned piglets was confirmed via PCR and Southern blot analysis. The ATM gene-targeted pigs generated in the present study may provide an alternative to the current mouse model for the study of mechanisms underlying A-T disorder and for the development of new therapies

  7. Classification of breast cancer patients using somatic mutation profiles and machine learning approaches.

    Science.gov (United States)

    Vural, Suleyman; Wang, Xiaosheng; Guda, Chittibabu

    2016-08-26

    The high degree of heterogeneity observed in breast cancers makes it very difficult to classify the cancer patients into distinct clinical subgroups and consequently limits the ability to devise effective therapeutic strategies. Several classification strategies based on ER/PR/HER2 expression or the expression profiles of a panel of genes have helped, but such methods often produce misleading results due to their dynamic nature. In contrast, somatic DNA mutations are relatively stable and lead to initiation and progression of many sporadic cancers. Hence in this study, we explore the use of gene mutation profiles to classify, characterize and predict the subgroups of breast cancers. We analyzed the whole exome sequencing data from 358 ethnically similar breast cancer patients in The Cancer Genome Atlas (TCGA) project. Somatic and non-synonymous single nucleotide variants identified from each patient were assigned a quantitative score (C-score) that represents the extent of negative impact on the gene function. Using these scores with non-negative matrix factorization method, we clustered the patients into three subgroups. By comparing the clinical stage of patients, we identified an early-stage-enriched and a late-stage-enriched subgroup. Comparison of the mutation scores of early and late-stage-enriched subgroups identified 358 genes that carry significantly higher mutations rates in the late stage subgroup. Functional characterization of these genes revealed important functional gene families that carry a heavy mutational load in the late state rich subgroup of patients. Finally, using the identified subgroups, we also developed a supervised classification model to predict the stage of the patients. This study demonstrates that gene mutation profiles can be effectively used with unsupervised machine-learning methods to identify clinically distinguishable breast cancer subgroups. The classification model developed in this method could provide a reasonable

  8. Seemingly neutral polymorphic variants may confer immunity to splicing-inactivating mutations

    DEFF Research Database (Denmark)

    Nielsen, Karsten Bork; Sørensen, Suzette; Cartegni, Luca

    2007-01-01

    assays to show that a missense mutation in exon 5 of the medium-chain acyl-CoA dehydrogenase (MCAD) gene primarily causes exon skipping by inactivating a crucial exonic splicing enhancer (ESE), thus leading to loss of a functional protein and to MCAD deficiency. This ESE functions by antagonizing...

  9. Whole-genome sequencing identifies recurrent somatic NOTCH2 mutations in splenic marginal zone lymphoma.

    Science.gov (United States)

    Kiel, Mark J; Velusamy, Thirunavukkarasu; Betz, Bryan L; Zhao, Lili; Weigelin, Helmut G; Chiang, Mark Y; Huebner-Chan, David R; Bailey, Nathanael G; Yang, David T; Bhagat, Govind; Miranda, Roberto N; Bahler, David W; Medeiros, L Jeffrey; Lim, Megan S; Elenitoba-Johnson, Kojo S J

    2012-08-27

    Splenic marginal zone lymphoma (SMZL), the most common primary lymphoma of spleen, is poorly understood at the genetic level. In this study, using whole-genome DNA sequencing (WGS) and confirmation by Sanger sequencing, we observed mutations identified in several genes not previously known to be recurrently altered in SMZL. In particular, we identified recurrent somatic gain-of-function mutations in NOTCH2, a gene encoding a protein required for marginal zone B cell development, in 25 of 99 (∼25%) cases of SMZL and in 1 of 19 (∼5%) cases of nonsplenic MZLs. These mutations clustered near the C-terminal proline/glutamate/serine/threonine (PEST)-rich domain, resulting in protein truncation or, rarely, were nonsynonymous substitutions affecting the extracellular heterodimerization domain (HD). NOTCH2 mutations were not present in other B cell lymphomas and leukemias, such as chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL; n = 15), mantle cell lymphoma (MCL; n = 15), low-grade follicular lymphoma (FL; n = 44), hairy cell leukemia (HCL; n = 15), and reactive lymphoid hyperplasia (n = 14). NOTCH2 mutations were associated with adverse clinical outcomes (relapse, histological transformation, and/or death) among SMZL patients (P = 0.002). These results suggest that NOTCH2 mutations play a role in the pathogenesis and progression of SMZL and are associated with a poor prognosis.

  10. The induction of somatic mutations by high-LET radiation observed using the Drosophila assay system

    International Nuclear Information System (INIS)

    Yoshikawa, Isao; Takatsuji, Toshihiro; Nagano, Masaaki; Hoshi, Masaharu; Takada, Jun; Endo, Satoru

    1999-01-01

    To evaluate the mutagenic potential of high-LET radiation, an analysis was made on the production of somatic mutations by 252 Cf fission neutron s and heavy particle ions accelerated by a synchrotron. A Drosophila strain that allows simultaneous detection of two types of mutations in an identical fly was constructed. One was a wing-hair mutation and the other was an eye-color mosaic spot mutation. Measurements were made using a combined assay system of both mutation assays. Larvae were exposed to radiation at the age of post-ovipositional day-3. The efficiency of 252 Cf neutrons for inducing wing-hair mosaic spots was very high, the relative biological effectiveness (RBE) = 8.5, but the efficiency for eye-color mosaic spot was nearly equal (RBE = 1.2) to that of 137 Cs γ-rays. The RBE of carbon ions for inducing wing-hair mosaic spots increased as an increase in LET values. The RBE for the induction of eye-color mutants did not change with LET. These relationships suggest that more complex types of DNA damages such as non-rejoinable strand break or clustered double strand break, which increase with LET may be responsible for the induction of wing-hair mutation, while simpler forms of molecular damage may induce a reversion in the white-ivory allele. (M.N.)

  11. Environmental modulation of somatic mutations: nature of interactions. Final report, 1 June 1974--31 May 1977

    International Nuclear Information System (INIS)

    Mericle, L.W.

    1977-05-01

    Research on this project has had as a major goal a combined ecologic-genetic investigation of somatic mutations in order to evaluate the impacts of certain changing environmental parameters. The ultimate aim, to better understand how such environmental-mutation interactions operate and to assure the information obtained be extrapolatable to conditions and events in nature. Higher plants delineate reproductive tissues late in development from meristematic, somatic tissues. Moreover, the prevailing method of reproduction may be without sexual fusion of gametes and/or wholly asexual (vegetative). Therefore, somatic mutations can have as far-reaching genetic significance for a plant population as when germ cells, themselves, are directly affected. Our data show diurnal temperature differences (DTD) of greater than or equal to 22.2 C-degrees to be very effective mutagenic agents in the Tradescantia somatic mutation system. Further, these ranges of DTD were found to occur often in important seed production areas. A DTD of 22.2 in magnitude can increase mutations 10-fold. And, durations short as 1-day can induce significant increases in mutation rate. Whether interaction of 22.2 DTD with low-level radiation (800 mR/day) is synergistic or attenuative is still debatable. We believe, however, that spontaneous, and 22.2 DTD induced, mutations occur mainly via the genetic mechanism of somatic crossing-over; mutations from acute ionizing radiation (e.g., 30-60 R γ) via chromosome breakage, producing micronuclei. Requirements for maximizing the Discriminatory Response Capability (DRC) in the Tradescantia somatic mutation system are set forth

  12. Somatic mutations associated with MRI-derived volumetric features in glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Gutman, David A.; Dunn, William D. [Emory University School of Medicine, Departments of Neurology, Atlanta, GA (United States); Emory University School of Medicine, Biomedical Informatics, Atlanta, GA (United States); Grossmann, Patrick; Alexander, Brian M. [Harvard Medical School, Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital, Boston, MA (United States); Cooper, Lee A.D. [Emory University School of Medicine, Biomedical Informatics, Atlanta, GA (United States); Georgia Institute of Technology, Department of Biomedical Engineering, Atlanta, GA (United States); Holder, Chad A. [Emory University School of Medicine, Radiology and Imaging Sciences, Atlanta, GA (United States); Ligon, Keith L. [Brigham and Women' s Hospital, Harvard Medical School, Pathology, Dana-Farber Cancer Institute, Boston, MA (United States); Aerts, Hugo J.W.L. [Harvard Medical School, Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital, Boston, MA (United States); Brigham and Women' s Hospital, Harvard Medical School, Radiology, Dana-Farber Cancer Institute, Boston, MA (United States)

    2015-12-15

    MR imaging can noninvasively visualize tumor phenotype characteristics at the macroscopic level. Here, we investigated whether somatic mutations are associated with and can be predicted by MRI-derived tumor imaging features of glioblastoma (GBM). Seventy-six GBM patients were identified from The Cancer Imaging Archive for whom preoperative T1-contrast (T1C) and T2-FLAIR MR images were available. For each tumor, a set of volumetric imaging features and their ratios were measured, including necrosis, contrast enhancing, and edema volumes. Imaging genomics analysis assessed the association of these features with mutation status of nine genes frequently altered in adult GBM. Finally, area under the curve (AUC) analysis was conducted to evaluate the predictive performance of imaging features for mutational status. Our results demonstrate that MR imaging features are strongly associated with mutation status. For example, TP53-mutated tumors had significantly smaller contrast enhancing and necrosis volumes (p = 0.012 and 0.017, respectively) and RB1-mutated tumors had significantly smaller edema volumes (p = 0.015) compared to wild-type tumors. MRI volumetric features were also found to significantly predict mutational status. For example, AUC analysis results indicated that TP53, RB1, NF1, EGFR, and PDGFRA mutations could each be significantly predicted by at least one imaging feature. MRI-derived volumetric features are significantly associated with and predictive of several cancer-relevant, drug-targetable DNA mutations in glioblastoma. These results may shed insight into unique growth characteristics of individual tumors at the macroscopic level resulting from molecular events as well as increase the use of noninvasive imaging in personalized medicine. (orig.)

  13. Somatic mutations associated with MRI-derived volumetric features in glioblastoma

    International Nuclear Information System (INIS)

    Gutman, David A.; Dunn, William D.; Grossmann, Patrick; Alexander, Brian M.; Cooper, Lee A.D.; Holder, Chad A.; Ligon, Keith L.; Aerts, Hugo J.W.L.

    2015-01-01

    MR imaging can noninvasively visualize tumor phenotype characteristics at the macroscopic level. Here, we investigated whether somatic mutations are associated with and can be predicted by MRI-derived tumor imaging features of glioblastoma (GBM). Seventy-six GBM patients were identified from The Cancer Imaging Archive for whom preoperative T1-contrast (T1C) and T2-FLAIR MR images were available. For each tumor, a set of volumetric imaging features and their ratios were measured, including necrosis, contrast enhancing, and edema volumes. Imaging genomics analysis assessed the association of these features with mutation status of nine genes frequently altered in adult GBM. Finally, area under the curve (AUC) analysis was conducted to evaluate the predictive performance of imaging features for mutational status. Our results demonstrate that MR imaging features are strongly associated with mutation status. For example, TP53-mutated tumors had significantly smaller contrast enhancing and necrosis volumes (p = 0.012 and 0.017, respectively) and RB1-mutated tumors had significantly smaller edema volumes (p = 0.015) compared to wild-type tumors. MRI volumetric features were also found to significantly predict mutational status. For example, AUC analysis results indicated that TP53, RB1, NF1, EGFR, and PDGFRA mutations could each be significantly predicted by at least one imaging feature. MRI-derived volumetric features are significantly associated with and predictive of several cancer-relevant, drug-targetable DNA mutations in glioblastoma. These results may shed insight into unique growth characteristics of individual tumors at the macroscopic level resulting from molecular events as well as increase the use of noninvasive imaging in personalized medicine. (orig.)

  14. The Impact of Environmental and Endogenous Damage on Somatic Mutation Load in Human Skin Fibroblasts.

    Directory of Open Access Journals (Sweden)

    Natalie Saini

    2016-10-01

    Full Text Available Accumulation of somatic changes, due to environmental and endogenous lesions, in the human genome is associated with aging and cancer. Understanding the impacts of these processes on mutagenesis is fundamental to understanding the etiology, and improving the prognosis and prevention of cancers and other genetic diseases. Previous methods relying on either the generation of induced pluripotent stem cells, or sequencing of single-cell genomes were inherently error-prone and did not allow independent validation of the mutations. In the current study we eliminated these potential sources of error by high coverage genome sequencing of single-cell derived clonal fibroblast lineages, obtained after minimal propagation in culture, prepared from skin biopsies of two healthy adult humans. We report here accurate measurement of genome-wide magnitude and spectra of mutations accrued in skin fibroblasts of healthy adult humans. We found that every cell contains at least one chromosomal rearrangement and 600–13,000 base substitutions. The spectra and correlation of base substitutions with epigenomic features resemble many cancers. Moreover, because biopsies were taken from body parts differing by sun exposure, we can delineate the precise contributions of environmental and endogenous factors to the accrual of genetic changes within the same individual. We show here that UV-induced and endogenous DNA damage can have a comparable impact on the somatic mutation loads in skin fibroblasts. Trial Registration: ClinicalTrials.gov NCT01087307.

  15. Development of a human somatic mutation detection method--GPA assay

    International Nuclear Information System (INIS)

    Mao Jianping; Dong Yan; Liu Bin; Lin Ruxian; Sun Zhixian

    2000-01-01

    Objective: To study the damage to human body caused by environmental radiation, and supervise the somatic mutations. Methods: Three monoclonal antibodies specific to M-type(3G4), N-type(6A8), and MN-type (3C5) of glycophorin A, respectively, were prepared. Fluorescence or biotin conjugated antibodies were bound specifically to formalin and/or dimethyl suber-imidate fixed erythrocytes. M, MN and N type cells were divided by cytometry to demonstrate the erythrocyte mutation characteristics (MN→MO, MM, NO, NN) and give out the variant frequency. Results: 1Wa, 1Wb and 2Wa methods of GPA assay were developed. Erythrocytes of MN type individuals could be separated to normal and single locus variant groups by 1W methods and they could be sorted as normal (MN), single gene deletion mutants (MO, NO), homozygous mutants (MM, NN) cell groups by 2Wa method. Conclusion: The assay is applicable to evaluating the frequency of variant erythrocytes from human somatic mutation

  16. Evaluation of Nine Somatic Variant Callers for Detection of Somatic Mutations in Exome and Targeted Deep Sequencing Data

    DEFF Research Database (Denmark)

    Krøigård, Anne Bruun; Thomassen, Mads; Lænkholm, Anne Vibeke

    2016-01-01

    a comprehensive evaluation using exome sequencing and targeted deep sequencing data of paired tumor-normal samples from five breast cancer patients to evaluate the performance of nine publicly available somatic variant callers: EBCall, Mutect, Seurat, Shimmer, Indelocator, Somatic Sniper, Strelka, VarScan 2...

  17. Somatic mutation in peripheral blood lymphocytes among Metro Manila residents: indicator of exposure to environmental pollution

    International Nuclear Information System (INIS)

    Yulo-Nazarea, Teresa; Cobar, Ma. Lucia C.; Nato, Alejandro Q.; Nazarea, Apolinario D.

    2001-01-01

    Results of a four-year study on somatic mutation in peripheral blood lymphocytes among Metro Manila residents as an indicator of exposure to environmental pollution conducted by the Philippine Nuclear Research Institute (PNRI) is presented. The study which involves mutation indexing of 200 blood donors demonstrated very strong correlation between high levels of ambient air pollution and increase incidence of mutation at the specific gene locus in peripheral blood lymphocytes among residents of specific areas in Metro Manila. Using the PNRI adapted protocol to determine incidence of mutation at a specific gene marker, hypoxanthine guanine phosphoribosyl transferase (HGPRT), our database analysis indicated a statistically significant difference between mean mutation index of blood donors residing in an area with lower level of pollution (Las Pinas) compared to those residents living in areas with the highest estimated pollution level (Valenzuela). The results of the statistical analyses should provide regulators the direction in incorporating the data into their pollution abatement program to maximize health impact. Biomarker analysis should play a greater role in the future in the formulation of national environment policies. The temporal variation of these ''aseline data'' as the Philippine moves forward through the next several years in its industrialization program should in itself be a very valuable source of environmental policy instruments. (Author)

  18. Endometrial cancer and somatic G>T KRAS transversion in patients with constitutional MUTYH biallelic mutations.

    Science.gov (United States)

    Tricarico, Rossella; Bet, Paola; Ciambotti, Benedetta; Di Gregorio, Carmela; Gatteschi, Beatrice; Gismondi, Viviana; Toschi, Benedetta; Tonelli, Francesco; Varesco, Liliana; Genuardi, Maurizio

    2009-02-18

    MUTYH-associated polyposis (MAP) is an autosomal recessive condition predisposing to colorectal cancer, caused by constitutional biallelic mutations in the base excision repair (BER) gene MUTYH. Colorectal tumours from MAP patients display an excess of somatic G>T mutations in the APC and KRAS genes due to defective BER function. To date, few extracolonic manifestations have been observed in MAP patients, and the clinical spectrum of this condition is not yet fully established. Recently, one patient with a diagnosis of endometrial cancer and biallelic MUTYH mutations has been described. We here report on two additional unrelated MAP patients with biallelic MUTYH germline mutations who developed endometrioid endometrial carcinoma. The endometrial tumours were evaluated for PTEN, PIK3CA, KRAS, BRAF and CTNNB1 mutations. A G>T transversion at codon 12 of the KRAS gene was observed in one tumour. A single 1bp frameshift deletion of PTEN was observed in the same sample. Overall, these findings suggest that endometrial carcinoma is a phenotypic manifestations of MAP and that inefficient repair of oxidative damage can be involved in its pathogenesis.

  19. Clinical implications of somatic mutations in aplastic anemia and myelodysplastic syndrome in genomic age.

    Science.gov (United States)

    Maciejewski, Jaroslaw P; Balasubramanian, Suresh K

    2017-12-08

    Recent technological advances in genomics have led to the discovery of new somatic mutations and have brought deeper insights into clonal diversity. This discovery has changed not only the understanding of disease mechanisms but also the diagnostics and clinical management of bone marrow failure. The clinical applications of genomics include enhancement of current prognostic schemas, prediction of sensitivity or refractoriness to treatments, and conceptualization and selective application of targeted therapies. However, beyond these traditional clinical aspects, complex hierarchical clonal architecture has been uncovered and linked to the current concepts of leukemogenesis and stem cell biology. Detection of clonal mutations, otherwise typical of myelodysplastic syndrome, in the course of aplastic anemia (AA) and paroxysmal nocturnal hemoglobinuria has led to new pathogenic concepts in these conditions and created a new link between AA and its clonal complications, such as post-AA and paroxysmal nocturnal hemoglobinuria. Distinctions among founder vs subclonal mutations, types of clonal evolution (linear or branching), and biological features of individual mutations (sweeping, persistent, or vanishing) will allow for better predictions of the biologic impact they impart in individual cases. As clonal markers, mutations can be used for monitoring clonal dynamics of the stem cell compartment during physiologic aging, disease processes, and leukemic evolution. © 2016 by The American Society of Hematology. All rights reserved.

  20. Somatic mutation and recombination induced with reactor thermal neutrons in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Zambrano A, F.; Guzman R, J.; Paredes G, L.; Delfin L, A.

    1997-01-01

    The SMART test of Drosophila melanogaster was used to quantify the effect over the somatic mutation and recombination induced by thermal and fast neutrons at the TRIGA Mark III reactor of the ININ at the power of 300 k W for times of 30, 60 and 120 minutes with total equivalent doses respectively of 20.8, 41.6 and 83.2 Sv. A linear relation between the radiation equivalent dose and the frequency of the genetic effects such as mutation and recombination was observed. The obtained results allow to conclude that SMART is a sensitive system to the induced damage by neutrons, so this can be used for studying its biological effects. (Author)

  1. Somatic loss of function mutations in neurofibromin 1 and MYC associated factor X genes identified by exome-wide sequencing in a wild-type GIST case

    International Nuclear Information System (INIS)

    Belinsky, Martin G.; Rink, Lori; Cai, Kathy Q.; Capuzzi, Stephen J.; Hoang, Yen; Chien, Jeremy; Godwin, Andrew K.; Mehren, Margaret von

    2015-01-01

    Approximately 10–15 % of gastrointestinal stromal tumors (GISTs) lack gain of function mutations in the KIT and platelet-derived growth factor receptor alpha (PDGFRA) genes. An alternate mechanism of oncogenesis through loss of function of the succinate-dehydrogenase (SDH) enzyme complex has been identified for a subset of these “wild type” GISTs. Paired tumor and normal DNA from an SDH-intact wild-type GIST case was subjected to whole exome sequencing to identify the pathogenic mechanism(s) in this tumor. Selected findings were further investigated in panels of GIST tumors through Sanger DNA sequencing, quantitative real-time PCR, and immunohistochemical approaches. A hemizygous frameshift mutation (p.His2261Leufs*4), in the neurofibromin 1 (NF1) gene was identified in the patient’s GIST; however, no germline NF1 mutation was found. A somatic frameshift mutation (p.Lys54Argfs*31) in the MYC associated factor X (MAX) gene was also identified. Immunohistochemical analysis for MAX on a large panel of GISTs identified loss of MAX expression in the MAX-mutated GIST and in a subset of mainly KIT-mutated tumors. This study suggests that inactivating NF1 mutations outside the context of neurofibromatosis may be the oncogenic mechanism for a subset of sporadic GIST. In addition, loss of function mutation of the MAX gene was identified for the first time in GIST, and a broader role for MAX in GIST progression was suggested. The online version of this article (doi:10.1186/s12885-015-1872-y) contains supplementary material, which is available to authorized users

  2. Diphtheria toxin resistance in human lymphocytes and lymphoblasts in the in vivo somatic cell mutation test

    International Nuclear Information System (INIS)

    Tomkins, D.J.; Wei, L.; Laurie, K.E.

    1985-01-01

    It has been shown that circulating peripheral blood lymphocytes can be used for the enumeration of 6-thioguanine-resistant cells that presumably arise by mutation in vivo. This somatic cell mutation test has been studied in lymphocytes from human populations exposed to known mutagens and/or carcinogens. The sensitivity of the test could be further enhanced by including other gene markers, since there is evidence for locus-specific differences in response to mutagens. Resistance to diphtheria toxin (Dip/sup r/) seemed like a potential marker to incorporate into the test because the mutation acts codominantly, can readily be selected in human diploid fibroblasts and Chinese hamster cells with no evidence for cell density or cross-feeding effects, and can be assayed for in nondividing cells by measuring protein synthesis inhibition. Blood samples were collected from seven individuals, and fresh, cryopreserved, or Epstein-Barr virus (EBV)-transformed lymphocytes were tested for continued DNA synthesis ( 3 H-thymidine, autoradiography) or protein synthesis ( 35 S-methionine, scintillation counting). Both fresh and cryopreserved lymphocytes, stimulated to divide with phytohemagglutinin (PHA), continued to synthesize DNA in the presence of high doses of diphtheria toxin (DT). Similarly, both dividing (PHA-stimulated) and nondividing fresh lymphocytes carried on significant levels of protein synthesis even 68 hr after exposure to 100 flocculating units (LF)/ml DT. The results suggest that human T and B lymphocytes may not be as sensitive to DT protein synthesis inhibition as human fibroblast and Chinese hamster cells. For this reason, Dip/sup r/ may not be a suitable marker for the somatic cell mutation test

  3. Nelson`s syndrome associated with a somatic frame shift mutation in the glucocorticoid recepter gene

    Energy Technology Data Exchange (ETDEWEB)

    Karl, M.; Stratakis, C.A.; Chrousos, G.P.; Katz, D.A.; Ali, I.U.; Oldfield, E.H. [National Inst. of Neurological Disorders and Stroke, Bethesda, MD (United States)] [and others

    1996-01-01

    Nelson`s syndrome is the appearance and/or progression of ACTH-secreting pituitary macroadenomas in patients who had previously undergone bilateral adrenalectomy for Cushing`s disease. Extremely high plasma ACTH levels and aggressive neoplastic growth might be explained by the lack of appropriate glucocorticoid negative feedback due to defective glucocorticoid signal transduction. To study the glucocorticoid receptor (GR) gene in Nelson`s syndrome, DNA was extracted from pituitary adenomas and leukocytes of four patients with this condition and amplified by PCR for direct sequence analysis. In one of the tumors, a heterozygous mutation, consisting of an insertion of a thymine between complementary DNA nucleotides 1188 and 1189, was found in exon 2. This frame-shift mutation led to premature termination at amino acid residue 366 of the world-type coding sequence, excluding the expression of a functioning receptor protein from the defective allele. The mutation was not detected in the sequence of the GR gene in the patient`s leukocyte DNA, indicating a somatic origin. By lowering the receptor number in tumorous cells, this defect might have caused local resistance to negative glucocorticoid feedback similar to that caused by the presence of a null allele in a kindred with the generalized glucocorticoid resistance syndrome. P53 protein accumulation, previously reported in 60% of corticotropinomas, could not be detected in any of the four pituitary tumors examined by immunohistochemistry. We suggest that a somatic GR defect might have played a pathophysiological role in the tumorigenesis of the corticotropinoma bearing this mutation. 35 refs., 3 figs., 1 tab.

  4. Somatic mosaicism of a CDKL5 mutation identified by next-generation sequencing.

    Science.gov (United States)

    Kato, Takeshi; Morisada, Naoya; Nagase, Hiroaki; Nishiyama, Masahiro; Toyoshima, Daisaku; Nakagawa, Taku; Maruyama, Azusa; Fu, Xue Jun; Nozu, Kandai; Wada, Hiroko; Takada, Satoshi; Iijima, Kazumoto

    2015-10-01

    CDKL5-related encephalopathy is an X-linked dominantly inherited disorder that is characterized by early infantile epileptic encephalopathy or atypical Rett syndrome. We describe a 5-year-old Japanese boy with intractable epilepsy, severe developmental delay, and Rett syndrome-like features. Onset was at 2 months, when his electroencephalogram showed sporadic single poly spikes and diffuse irregular poly spikes. We conducted a genetic analysis using an Illumina® TruSight™ One sequencing panel on a next-generation sequencer. We identified two epilepsy-associated single nucleotide variants in our case: CDKL5 p.Ala40Val and KCNQ2 p.Glu515Asp. CDKL5 p.Ala40Val has been previously reported to be responsible for early infantile epileptic encephalopathy. In our case, the CDKL5 heterozygous mutation showed somatic mosaicism because the boy's karyotype was 46,XY. The KCNQ2 variant p.Glu515Asp is known to cause benign familial neonatal seizures-1, and this variant showed paternal inheritance. Although we believe that the somatic mosaic CDKL5 mutation is mainly responsible for the neurological phenotype in the patient, the KCNQ2 variant might have some neurological effect. Genetic analysis by next-generation sequencing is capable of identifying multiple variants in a patient. Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  5. Molecular profiling of appendiceal epithelial tumors using massively parallel sequencing to identify somatic mutations.

    Science.gov (United States)

    Liu, Xiaoying; Mody, Kabir; de Abreu, Francine B; Pipas, J Marc; Peterson, Jason D; Gallagher, Torrey L; Suriawinata, Arief A; Ripple, Gregory H; Hourdequin, Kathryn C; Smith, Kerrington D; Barth, Richard J; Colacchio, Thomas A; Tsapakos, Michael J; Zaki, Bassem I; Gardner, Timothy B; Gordon, Stuart R; Amos, Christopher I; Wells, Wendy A; Tsongalis, Gregory J

    2014-07-01

    Some epithelial neoplasms of the appendix, including low-grade appendiceal mucinous neoplasm and adenocarcinoma, can result in pseudomyxoma peritonei (PMP). Little is known about the mutational spectra of these tumor types and whether mutations may be of clinical significance with respect to therapeutic selection. In this study, we identified somatic mutations using the Ion Torrent AmpliSeq Cancer Hotspot Panel v2. Specimens consisted of 3 nonneoplastic retention cysts/mucocele, 15 low-grade mucinous neoplasms (LAMNs), 8 low-grade/well-differentiated mucinous adenocarcinomas with pseudomyxoma peritonei, and 12 adenocarcinomas with/without goblet cell/signet ring cell features. Barcoded libraries were prepared from up to 10 ng of extracted DNA and multiplexed on single 318 chips for sequencing. Data analysis was performed using Golden Helix SVS. Variants that remained after the analysis pipeline were individually interrogated using the Integrative Genomics Viewer. A single Janus kinase 3 (JAK3) mutation was detected in the mucocele group. Eight mutations were identified in the V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) and GNAS complex locus (GNAS) genes among LAMN samples. Additional gene mutations were identified in the AKT1 (v-akt murine thymoma viral oncogene homolog 1), APC (adenomatous polyposis coli), JAK3, MET (met proto-oncogene), phosphatidylinositol-4,5-bisphosphate 3-kinase (PIK3CA), RB1 (retinoblastoma 1), STK11 (serine/threonine kinase 11), and tumor protein p53 (TP53) genes. Among the PMPs, 6 mutations were detected in the KRAS gene and also in the GNAS, TP53, and RB1 genes. Appendiceal cancers showed mutations in the APC, ATM (ataxia telangiectasia mutated), KRAS, IDH1 [isocitrate dehydrogenase 1 (NADP+)], NRAS [neuroblastoma RAS viral (v-ras) oncogene homolog], PIK3CA, SMAD4 (SMAD family member 4), and TP53 genes. Our results suggest molecular heterogeneity among epithelial tumors of the appendix. Next generation sequencing efforts

  6. Mutation inactivation of Nijmegen breakage syndrome gene (NBS1 in hepatocellular carcinoma and intrahepatic cholangiocarcinoma.

    Directory of Open Access Journals (Sweden)

    Yan Wang

    Full Text Available Nijmegen breakage syndrome (NBS with NBS1 germ-line mutation is a human autosomal recessive disease characterized by genomic instability and enhanced cancer predisposition. The NBS1 gene codes for a protein, Nbs1(p95/Nibrin, involved in the processing/repair of DNA double-strand breaks. Hepatocellular carcinoma (HCC is a complex and heterogeneous tumor with several genomic alterations. Recent studies have shown that heterozygous NBS1 mice exhibited a higher incidence of HCC than did wild-type mice. The objective of the present study is to assess whether NBS1 mutations play a role in the pathogenesis of human primary liver cancer, including HBV-associated HCC and intrahepatic cholangiocarcinoma (ICC. Eight missense NBS1 mutations were identified in six of 64 (9.4% HCCs and two of 18 (11.1% ICCs, whereas only one synonymous mutation was found in 89 control cases of cirrhosis and chronic hepatitis B. Analysis of the functional consequences of the identified NBS1 mutations in Mre11-binding domain showed loss of nuclear localization of Nbs1 partner Mre11, one of the hallmarks for Nbs1 deficiency, in one HCC and two ICCs with NBS1 mutations. Moreover, seven of the eight tumors with NBS1 mutations had at least one genetic alteration in the TP53 pathway, including TP53 mutation, MDM2 amplification, p14ARF homozygous deletion and promoter methylation, implying a synergistic effect of Nbs1 disruption and p53 inactivation. Our findings provide novel insight on the molecular pathogenesis of primary liver cancer characterized by mutation inactivation of NBS1, a DNA repair associated gene.

  7. A threshold in the dose-response relationship for X-ray induced somatic mutation frequency in drosophila melanogaster

    International Nuclear Information System (INIS)

    Koana, Takao; Sakai, Kazuo; Okada, M.O.

    2004-01-01

    The dose-response relationship of ionizing radiation and its stochastic effects has been thought to be linear without any thresholds for a long time. The basic data for this model was obtained from mutational assays using germ cells of male fruit fly Drosophila melanogaster. However, cancer-causing activity should be examined more appropriately in somatic cells than in germ cells. In this paper, we examined the dose-response relationship of X-ray irradiation and somatic mutation in drosophila, and found a threshold at approximately 1 Gy in the DNA repair proficient flies. In the repair deficient siblings, the threshold was smaller and the inclination of the dose-response curve was five times steeper. These results suggest that the dose-response relationship between X-ray irradiation and somatic mutation has a threshold, and that the DNA repair function contributes to its formation. (author)

  8. In utero DNA damage from environmental pollution is associated with somatic gene mutation in newborns

    Energy Technology Data Exchange (ETDEWEB)

    Perera, F.; Hemminki, K.; Jedrychowski, W.; Whyatt, R.; Campbell, U.; Hsu, Y.Z.; Santella, R.; Albertini, R.; O' Neill, J.P. [Columbia University, New York, NY (United States). School of Public Health

    2002-10-01

    Transplacental exposure to carcinogenic air pollutants from the combustion of fossil fuels is a growing health concern, given evidence of the heightened susceptibility of the fetus. These mutagenic/carcinogenic pollutants include aromatic compounds such as polycyclic aromatic hydrocarbons that bind to DNA, forming chemical-DNA adducts. The genotoxic effects of transplacental exposure in humans has been investigated by analyzing aromatic-DNA adducts and the frequency of gene mutations at the hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus in umbilical cord and maternal blood samples. Here the authors show, in a cross-sectional study of 67 mothers and 64 newborns from the Krakow Region of Poland, that aromatic-DNA adducts measured by P-32-postlabeling are positively associated with HPRT mutant frequency in the newborns (beta = 0.56, P = 0.03) after controlling for exposure to tobacco smoke, diet, and socioeconomic status. In contrast to the fetus, HPRT mutations and DNA adducts do not reflect similar exposure periods in the mother, and the maternal biomarkers were not correlated. Adducts were higher in the newborn than the mother, indicating differential susceptibility of the fetus to DNA damage; but HPRT mutation frequency was 4-fold lower, consistent with the long lifetime of the biomarker. These results provide the first demonstration of a molecular link between somatic mutation in the newborn and transplacental exposure to common air pollutants, a finding that is relevant to cancer risk assessment.

  9. Risk scaling factors from inactivation to chromosome aberrations, mutations and oncogenic transformations in mammalian cells

    International Nuclear Information System (INIS)

    Alkaharam, A.S.; Watt, D.E.

    1997-01-01

    Analyses of bio-effect mechanisms of damage to mammalian cells in terms of the quality parameter 'mean free path for primary ionisation', for heavy charged particles, strongly suggests that there is a common mechanism for the biological endpoints of chromosome aberrations, mutations and oncogenic transformation. The lethal lesions are identified as unrepaired double-strand breaks in the intracellular DNA. As data for the various endpoints studied can be represented in a unified scheme, for any radiation type, it follows that radiation risk factors can be determined on the basis of simple ratios to the inactivation cross sections. There are intrinsic physical reasons why neutrons can never reach the saturation level of heavier particles for equal fluences. The probabilities of risk with respect to inactivation, for chromosome dicentrics, mutation of the HPRT gene and of oncogenic transformation are respectively 0.24, 5.8 x 10 -5 , and 4.1 x 10 -3 . (author)

  10. Somatic mosaicism in families with hemophilia B: 11% of germline mutations originate within a few cell divisions post-fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Knoell, A.; Ketterling, R.P.; Vielhaber, E. [Mayo Clinic/Foundation, Rochester, MN (United States)] [and others

    1994-09-01

    Previous molecular estimates of mosaicism in the dystrophin and other genes generally have focused on the transmission of the mutated allele to two or more children by an individual without the mutation in leukocyte DNA. We have analyzed 414 families with hemophilia B by direct genomic sequencing and haplotype analysis, and have deduced the origin of mutation in 56 families. There was no origin individual who transmitted a mutant allele to more than one child. However, somatic mosaicism was detected by sequence analysis of four origin individuals (3{female} and 1{male}). The sensitivity of this analysis is typically one part in ten. In one additional female who had close to a 50:50 ratio of mutant to normal alleles, three of four noncarrier daughters inherited the haplotype associated with the mutant allele. This highlights a caveat in molecular analysis: a presumptive carrier in a family with sporadic disease does not necessarily have a 50% probability of transmitting the mutant allele to her offspring. After eliminating those families in which mosaicism could not be detected because of a total gene deletion or absence of DNA from a deduced origin individual, 5 of 43 origin individuals exhibited somatic mosaicism at a level that reflects a mutation within the first few cell divisions after fertilization. In one patient, analysis of cervical scrapings and buccal mucosa confirm the generalized distribution of somatic mutation. Are the first few cell divisions post-fertilization highly mutagenic, or do mutations at later divisions also give rise to somatic mosaicism? To address this question, DNA from origin individuals are being analyzed to detect somatic mosaicism at a sensitivity of 1:1000. Single nucleotide primer extension (SNuPE) has been utilized in eight families to date and no mosaicism has been detected. When the remaining 30 samples are analyzed, it will be possible to compare the frequency of somatic mosaicism at 0.1-10% with that of {ge}10%.

  11. Somatic mutations in stilbene estrogen-induced Syrian hamster kidney tumors identified by DNA fingerprinting

    Directory of Open Access Journals (Sweden)

    Roy Deodutta

    2004-01-01

    Full Text Available Abstract Kidney tumors from stilbene estrogen (diethylstilbestrol-treated Syrian hamsters were screened for somatic genetic alterations by Random Amplified Polymorphic DNA-polymerase chain-reaction (RAPD-PCR fingerprinting. Fingerprints from tumor tissue were generated by single arbitrary primers and compared with fingerprints for normal tissue from the same animal, as well as normal and tumor tissues from different animals. Sixty one of the arbitrary primers amplified 365 loci that contain approximately 476 kbp of the hamster genome. Among these amplified DNA fragments, 44 loci exhibited either qualitative or quantitative differences between the tumor tissues and normal kidney tissues. RAPD-PCR loci showing decreased and increased intensities in tumor tissue DNA relative to control DNA indicate that loci have undergone allelic losses and gains, respectively, in the stilbene estrogen-induced tumor cell genome. The presence or absence of the amplified DNA fragments indicate homozygous insertions or deletions in the kidney tumor DNA compared to the age-matched normal kidney tissue DNA. Seven of 44 mutated loci also were present in the kidney tissues adjacent to tumors (free of macroscopic tumors. The presence of mutated loci in uninvolved (non-tumor surrounding tissue adjacent to tumors from stilbene estrogen-treated hamsters suggests that these mutations occurred in the early stages of carcinogenesis. The cloning and sequencing of RAPD amplified loci revealed that one mutated locus had significant sequence similarity with the hamster Cyp1A1 gene. The results show the ability of RAPD-PCR to detect and isolate, in a single step, DNA sequences representing genetic alterations in stilbene estrogen-induced cancer cells, including losses of heterozygosity, and homozygous deletion and insertion mutations. RAPD-PCR provides an alternative molecular approach for studying cancer cytogenetics in stilbene estrogen-induced tumors in humans and experimental

  12. Distinct Mutations Led to Inactivation of Type 1 Fimbriae Expression in Shigella spp.

    Science.gov (United States)

    Bravo, Verónica; Puhar, Andrea; Sansonetti, Philippe; Parsot, Claude; Toro, Cecilia S.

    2015-01-01

    Shigella spp. are responsible for bacillary dysentery in humans. The acquisition or the modification of the virulence plasmid encoding factors promoting entry of bacteria into and dissemination within epithelial cells was a critical step in the evolution of these bacteria from their Escherichia coli ancestor(s). Incorporation of genomic islands (GI) and gene inactivation also shaped interactions between these pathogens and their human host. Sequence analysis of the GI inserted next to the leuX tRNA gene in S. boydii, S. dysenteriae, S. flexneri, S. sonnei and enteroinvasive E. coli (EIEC) suggests that this region initially carried the fec, yjhATS and fim gene clusters. The fim cluster encoding type I fimbriae is systematically inactivated in both reference strains and clinical isolates and distinct mutations are responsible for this inactivation in at least three phylogenetic groups. To investigate consequences of the presence of fimbriae on the outcome of the interaction of Shigella with host cells, we used a S. flexneri strain harboring a plasmid encoding the E. coli fim operon. Production of fimbriae by this recombinant strain increased the ability of bacteria to adhere to and enter into epithelial cells and had no effect on their ability to disseminate from cell to cell. The observations that production of type I fimbriae increases invasion of epithelial cells and that independent mutations abolish fimbriae production in Shigella suggest that these mutations correspond to pathoadaptive events. PMID:25811616

  13. Distinct mutations led to inactivation of type 1 fimbriae expression in Shigella spp.

    Directory of Open Access Journals (Sweden)

    Verónica Bravo

    Full Text Available Shigella spp. are responsible for bacillary dysentery in humans. The acquisition or the modification of the virulence plasmid encoding factors promoting entry of bacteria into and dissemination within epithelial cells was a critical step in the evolution of these bacteria from their Escherichia coli ancestor(s. Incorporation of genomic islands (GI and gene inactivation also shaped interactions between these pathogens and their human host. Sequence analysis of the GI inserted next to the leuX tRNA gene in S. boydii, S. dysenteriae, S. flexneri, S. sonnei and enteroinvasive E. coli (EIEC suggests that this region initially carried the fec, yjhATS and fim gene clusters. The fim cluster encoding type I fimbriae is systematically inactivated in both reference strains and clinical isolates and distinct mutations are responsible for this inactivation in at least three phylogenetic groups. To investigate consequences of the presence of fimbriae on the outcome of the interaction of Shigella with host cells, we used a S. flexneri strain harboring a plasmid encoding the E. coli fim operon. Production of fimbriae by this recombinant strain increased the ability of bacteria to adhere to and enter into epithelial cells and had no effect on their ability to disseminate from cell to cell. The observations that production of type I fimbriae increases invasion of epithelial cells and that independent mutations abolish fimbriae production in Shigella suggest that these mutations correspond to pathoadaptive events.

  14. The induction of somatic mutations by high-LET radiations using the drosophila assay system

    International Nuclear Information System (INIS)

    Yoshikawa, Isao; Takatsuji, Toshihiro

    2004-01-01

    Two types of somatic mutation in Drosophila melanogaster were examined to evaluate the relative biological effectiveness (RBE) of 252 Cf neutrons and heavy ions (carbon ions and neon ions) accelerated with a synchrotron for inducing mutations as a function of linear energy transfer (LET). One is the loss of heterozygosity for wing-hair mutations and the other the reversion of the mutant white-ivory. The measurements were made using a combined mutation assay system; so that induced mutant wing-hair clones as well as revertant eye-color clones could be detected simultaneously in the same fly. Larvae were irradiated at the age of 3 days post-oviposition. The efficiency of 252 Cf neutrons for inducing wing-hair mosaic spots is very high, RBE=8.5, but that for eye-color mosaic spot is almost equal (RBE=1.2) to that of 137 Cs γ-rays. RBE-LET relationships were obtained for the induction of wing-hair and eye-color mosaic spots. The RBE of carbon and neon ions for producing wing-hair mosaic spots increased with increasing LET values. The RBE for the induction of eye-color mutants did not change with LET. These relationships suggest that more complex types of DNA damage such as non-rejoinable strand breaks or clustered double strand breaks that increase with LET may be responsible for inducing the wing-hair mutation, while simpler forms of molecular damage may induce reversion in the white-ivory allele. (author)

  15. Enhanced susceptibility of a transposable-element-bearing strain of Drosophila melanogaster to somatic eye-color mutations by ethyl nitrosourea, methyl nitrosourea, and X-rays

    International Nuclear Information System (INIS)

    Ryo, H.; Kondo, S.; Rasmuson, B.

    1983-01-01

    A strain of Drosophila with the genes z and w + plus a transposable element (TE) is about 3 times more sensitive than a strain without TE toward somatic eye-color mutations after larval exposure to ethyl nitrosourea, methyl nitrosourea and X-rays. The assay system with TE is simple, reliable, and sensitive for detecting somatic mutations induced in vivo by mutagens. (orig.)

  16. Inactivation and mutation induction in Saccharomyces cerevisiae exposed to simulated sunlight: evaluation of action spectra.

    Science.gov (United States)

    Schenk-Meuser, K; Pawlowsky, K; Kiefer, J

    1992-07-15

    The effectiveness of polychromatic light irradiation was investigated for haploid yeast cells. Inactivation and mutation induction were measured in both a RAD-wildtype strain and an excision-repair defective strain. The behaviour of vegetative "wet" cells was compared to that of dehydrated cells. The aim of the study was to assess the interaction of UVC with other wavelengths in cells of different states of humidity. The irradiation procedure was therefore carried out using a solar simulator either with full spectrum or with a UVC-blocking filter (modified sunlight) added. The results were analysed on the basis of separately determined action spectra. The summation of the efficiency of individual wavelengths was compared to the values obtained from polychromatic irradiation. It is shown that the effects caused by the whole-spectrum irradiation in wet cells can be predicted sufficiently from the calculation, while dried wildtype cells exhibit higher mutation rates. Thus it can be assumed that drying-specific damage leads to lethal and mutagenic lesions which are processed in different ways, causing a synergistic behaviour in mutation induction. Irradiation of vegetative cells with modified sunlight (UVC-) results in less inactivation and lower mutation rates than were calculated. From these results it can be concluded that this antagonistic behaviour is caused by the interaction of near-UV photoproducts.

  17. Discovery and prioritization of somatic mutations in diffuse large B-cell lymphoma (DLBCL) by whole-exome sequencing

    OpenAIRE

    Lohr, Jens G.; Stojanov, Petar; Lawrence, Michael S.; Auclair, Daniel; Chapuy, Bjoern; Sougnez, Carrie; Cruz-Gordillo, Peter; Knoechel, Birgit; Asmann, Yan W.; Slager, Susan L.; Novak, Anne J.; Dogan, Ahmet; Ansell, Stephen M.; Link, Brian K.; Zou, Lihua

    2012-01-01

    To gain insight into the genomic basis of diffuse large B-cell lymphoma (DLBCL), we performed massively parallel whole-exome sequencing of 55 primary tumor samples from patients with DLBCL and matched normal tissue. We identified recurrent mutations in genes that are well known to be functionally relevant in DLBCL, including MYD88, CARD11, EZH2, and CREBBP. We also identified somatic mutations in genes for which a functional role in DLBCL has not been previously suspected. These genes include...

  18. Abiotic stress leads to somatic and heritable changes in homologous recombination frequency, point mutation frequency and microsatellite stability in Arabidopsis plants

    International Nuclear Information System (INIS)

    Yao Youli; Kovalchuk, Igor

    2011-01-01

    In earlier studies, we showed that abiotic stresses, such as ionizing radiation, heavy metals, temperature and water, trigger an increase in homologous recombination frequency (HRF). We also demonstrated that many of these stresses led to inheritance of high-frequency homologous recombination, HRF. Although an increase in recombination frequency is an important indicator of genome rearrangements, it only represents a minor portion of possible stress-induced mutations. Here, we analyzed the influence of heat, cold, drought, flood and UVC abiotic stresses on two major types of mutations in the genome, point mutations and small deletions/insertions. We used two transgenic lines of Arabidopsis thaliana, one allowing an analysis of reversions in a stop codon-containing inactivated β-glucuronidase transgene and another one allowing an analysis of repeat stability in a microsatellite-interrupted β-glucuronidase transgene. The transgenic Arabidopsis line carrying the β-glucuronidase-based homologous recombination substrate was used as a positive control. We showed that the majority of stresses increased the frequency of point mutations, homologous recombination and microsatellite instability in somatic cells, with the frequency of homologous recombination being affected the most. The analysis of transgenerational changes showed an increase in HRF to be the most prominent effect observed in progeny. Significant changes in recombination frequency were observed upon exposure to all types of stress except drought, whereas changes in microsatellite instability were observed upon exposure to UVC, heat and cold. The frequency of point mutations in the progeny of stress-exposed plants was the least affected; an increase in mutation frequency was observed only in the progeny of plants exposed to UVC. We thus conclude that transgenerational changes in genome stability in response to stress primarily involve an increase in recombination frequency.

  19. Inactivating mutations in ESCO2 cause SC phocomelia and Roberts syndrome: no phenotype-genotype correlation.

    Science.gov (United States)

    Schüle, Birgitt; Oviedo, Angelica; Johnston, Kathreen; Pai, Shashidhar; Francke, Uta

    2005-12-01

    The rare, autosomal recessive Roberts syndrome (RBS) is characterized by tetraphocomelia, profound growth deficiency of prenatal onset, craniofacial anomalies, microcephaly, and mental deficiency. SC phocomelia (SC) has a milder phenotype, with a lesser degree of limb reduction and with survival to adulthood. Since heterochromatin repulsion (HR) is characteristic for both disorders and is not complemented in somatic-cell hybrids, it has been hypothesized that the disorders are allelic. Recently, mutations in ESCO2 (establishment of cohesion 1 homolog 2) on 8p21.1 have been reported in RBS. To determine whether ESCO2 mutations are also responsible for SC, we studied three families with SC and two families in which variable degrees of limb and craniofacial abnormalities, detected by fetal ultrasound, led to pregnancy terminations. All cases were positive for HR. We identified seven novel mutations in exons 3-8 of ESCO2. In two families, affected individuals were homozygous--for a 5-nucleotide deletion in one family and a splice-site mutation in the other. In three nonconsanguineous families, probands were compound heterozygous for a single-nucleotide insertion or deletion, a nonsense mutation, or a splice-site mutation. Abnormal splice products were characterized at the RNA level. Since only protein-truncating mutations were identified, regardless of clinical severity, we conclude that genotype does not predict phenotype. Having established that RBS and SC are caused by mutations in the same gene, we delineated the clinical phenotype of the tetraphocomelia spectrum that is associated with HR and ESCO2 mutations and differentiated it from other types of phocomelia that are negative for HR.

  20. Impact of kinase activating and inactivating patient mutations on binary PKA interactions.

    Science.gov (United States)

    Röck, Ruth; Mayrhofer, Johanna E; Bachmann, Verena; Stefan, Eduard

    2015-01-01

    The second messenger molecule cAMP links extracellular signals to intracellular responses. The main cellular cAMP effector is the compartmentalized protein kinase A (PKA). Upon receptor initiated cAMP-mobilization, PKA regulatory subunits (R) bind cAMP thereby triggering dissociation and activation of bound PKA catalytic subunits (PKAc). Mutations in PKAc or RIa subunits manipulate PKA dynamics and activities which contribute to specific disease patterns. Mutations activating cAMP/PKA signaling contribute to carcinogenesis or hormone excess, while inactivating mutations cause hormone deficiency or resistance. Here we extended the application spectrum of a Protein-fragment Complementation Assay based on the Renilla Luciferase to determine binary protein:protein interactions (PPIs) of the PKA network. We compared time- and dose-dependent influences of cAMP-elevation on mutually exclusive PPIs of PKAc with the phosphotransferase inhibiting RIIb and RIa subunits and the protein kinase inhibitor peptide (PKI). We analyzed PKA dynamics following integration of patient mutations into PKAc and RIa. We observed that oncogenic modifications of PKAc(L206R) and RIa(Δ184-236) as well as rare disease mutations in RIa(R368X) affect complex formation of PKA and its responsiveness to cAMP elevation. With the cell-based PKA PPI reporter platform we precisely quantified the mechanistic details how inhibitory PKA interactions and defined patient mutations contribute to PKA functions.

  1. Inactivation of protein translocation by cold-sensitive mutations in the yajC-secDF operon

    NARCIS (Netherlands)

    Nouwen, N; Driessen, AJM

    2005-01-01

    Most mutations in the yajC-secDF operon identified via genetic screens confer a cold-sensitive growth phenotype. Here we report that two of these mutations confer this cold-sensitive phenotype by inactivating the SecDF-YajC complex in protein translocation.

  2. Human aging and somatic point mutations in mtDNA: a comparative study of generational differences (grandparents and grandchildren

    Directory of Open Access Journals (Sweden)

    Anderson Nonato do Rosário Marinho

    2011-01-01

    Full Text Available The accumulation of somatic mutations in mtDNA is correlated with aging. In this work, we sought to identify somatic mutations in the HVS-1 region (D-loop of mtDNA that might be associated with aging. For this, we compared 31 grandmothers (mean age: 63 ± 2.3 years and their 62 grandchildren (mean age: 15 ± 4.1 years, the offspring of their daughters. Direct DNA sequencing showed that mutations absent in the grandchildren were detected in a presumably homoplasmic state in three grandmothers and in a heteroplasmic state in an additional 13 grandmothers; no mutations were detected in the remaining 15 grandmothers. However, cloning followed by DNA sequencing in 12 grandmothers confirmed homoplasia in only one of the three mutations previously considered to be homoplasmic and did not confirm heteroplasmy in three out of nine grandmothers found to be heteroplasmic by direct sequencing. Thus, of 12 grandmothers in whom mtDNA was analyzed by cloning, eight were heteroplasmic for mutations not detected in their grandchildren. In this study, the use of genetically related subjects allowed us to demonstrate the occurrence of age-related (> 60 years old mutations (homoplasia and heteroplasmy. It is possible that both of these situations (homoplasia and heteroplasmy were a long-term consequence of mitochondrial oxidative phosphorylation that can lead to the accumulation of mtDNA mutations throughout life.

  3. Discovery and prioritization of somatic mutations in diffuse large B-cell lymphoma (DLBCL) by whole-exome sequencing

    Science.gov (United States)

    Lohr, Jens G.; Stojanov, Petar; Lawrence, Michael S.; Auclair, Daniel; Chapuy, Bjoern; Sougnez, Carrie; Cruz-Gordillo, Peter; Knoechel, Birgit; Asmann, Yan W.; Slager, Susan L.; Novak, Anne J.; Dogan, Ahmet; Ansell, Stephen M.; Zou, Lihua; Gould, Joshua; Saksena, Gordon; Stransky, Nicolas; Rangel-Escareño, Claudia; Fernandez-Lopez, Juan Carlos; Hidalgo-Miranda, Alfredo; Melendez-Zajgla, Jorge; Hernández-Lemus, Enrique; Schwarz-Cruz y Celis, Angela; Imaz-Rosshandler, Ivan; Ojesina, Akinyemi I.; Jung, Joonil; Pedamallu, Chandra S.; Lander, Eric S.; Habermann, Thomas M.; Cerhan, James R.; Shipp, Margaret A.; Getz, Gad; Golub, Todd R.

    2012-01-01

    To gain insight into the genomic basis of diffuse large B-cell lymphoma (DLBCL), we performed massively parallel whole-exome sequencing of 55 primary tumor samples from patients with DLBCL and matched normal tissue. We identified recurrent mutations in genes that are well known to be functionally relevant in DLBCL, including MYD88, CARD11, EZH2, and CREBBP. We also identified somatic mutations in genes for which a functional role in DLBCL has not been previously suspected. These genes include MEF2B, MLL2, BTG1, GNA13, ACTB, P2RY8, PCLO, and TNFRSF14. Further, we show that BCL2 mutations commonly occur in patients with BCL2/IgH rearrangements as a result of somatic hypermutation normally occurring at the IgH locus. The BCL2 point mutations are primarily synonymous, and likely caused by activation-induced cytidine deaminase–mediated somatic hypermutation, as shown by comprehensive analysis of enrichment of mutations in WRCY target motifs. Those nonsynonymous mutations that are observed tend to be found outside of the functionally important BH domains of the protein, suggesting that strong negative selection against BCL2 loss-of-function mutations is at play. Last, by using an algorithm designed to identify likely functionally relevant but infrequent mutations, we identify KRAS, BRAF, and NOTCH1 as likely drivers of DLBCL pathogenesis in some patients. Our data provide an unbiased view of the landscape of mutations in DLBCL, and this in turn may point toward new therapeutic strategies for the disease. PMID:22343534

  4. TGF-beta Sma/Mab signaling mutations uncouple reproductive aging from somatic aging.

    Directory of Open Access Journals (Sweden)

    Shijing Luo

    2009-12-01

    Full Text Available Female reproductive cessation is one of the earliest age-related declines humans experience, occurring in mid-adulthood. Similarly, Caenorhabditis elegans' reproductive span is short relative to its total life span, with reproduction ceasing about a third into its 15-20 day adulthood. All of the known mutations and treatments that extend C. elegans' reproductive period also regulate longevity, suggesting that reproductive span is normally linked to life span. C. elegans has two canonical TGF-beta signaling pathways. We recently found that the TGF-beta Dauer pathway regulates longevity through the Insulin/IGF-1 Signaling (IIS pathway; here we show that this pathway has a moderate effect on reproductive span. By contrast, TGF-beta Sma/Mab signaling mutants exhibit a substantially extended reproductive period, more than doubling reproductive span in some cases. Sma/Mab mutations extend reproductive span disproportionately to life span and act independently of known regulators of somatic aging, such as Insulin/IGF-1 Signaling and Dietary Restriction. This is the first discovery of a pathway that regulates reproductive span independently of longevity and the first identification of the TGF-beta Sma/Mab pathway as a regulator of reproductive aging. Our results suggest that longevity and reproductive span regulation can be uncoupled, although they appear to normally be linked through regulatory pathways.

  5. Distinct subtype distribution and somatic mutation spectrum of lymphomas in East Asia.

    Science.gov (United States)

    Ren, Weicheng; Li, Wei; Ye, Xiaofei; Liu, Hui; Pan-Hammarström, Qiang

    2017-07-01

    Here, we give an updated overview of the subtype distribution of lymphomas in East Asia and also present the genome sequencing data on two major subtypes of these tumors. The distribution of lymphoma types/subtypes among East Asian countries is very similar, with a lower proportion of B-cell malignancies and a higher proportion of T/natural killer (NK)-cell lymphomas as compared to Western populations. Extranodal NK/T-cell lymphoma is more frequently observed in East Asia, whereas follicular lymphoma and chronic lymphocytic leukemia, are proportionally lower. The incidence rate of lymphoma subtypes in Asians living in the US was generally intermediate to the general rate in US and Asia, suggesting that both genetic and environmental factors may underlie the geographical variations observed.Key cancer driver mutations have been identified in Asian patients with diffuse large B-cell lymphoma or extranodal NK/T-cell lymphoma through genome sequencing. A distinct somatic mutation profile has also been observed in Chinese diffuse large B-cell lymphoma patients. The incidence and distribution of lymphoma subtypes differed significantly between patients from East Asia and Western countries, suggesting subtype-specific etiologic mechanisms. Further studies on the mechanism underlying these geographical variations may give new insights into our understanding of lymphomagenesis.

  6. Next generation sequencing of Cytokeratin 20-negative Merkel cell carcinoma reveals ultraviolet-signature mutations and recurrent TP53 and RB1 inactivation.

    Science.gov (United States)

    Harms, Paul W; Collie, Angela M B; Hovelson, Daniel H; Cani, Andi K; Verhaegen, Monique E; Patel, Rajiv M; Fullen, Douglas R; Omata, Kei; Dlugosz, Andrzej A; Tomlins, Scott A; Billings, Steven D

    2016-03-01

    Merkel cell carcinoma is a rare but highly aggressive cutaneous neuroendocrine carcinoma. Cytokeratin 20 (CK20) is expressed in ~95% of Merkel cell carcinomas and is useful for distinction from morphologically similar entities including metastatic small-cell lung carcinoma. Lack of CK20 expression may make diagnosis of Merkel cell carcinoma more challenging, and has unknown biological significance. Approximately 80% of CK20-positive Merkel cell carcinomas are associated with the oncogenic Merkel cell polyomavirus. Merkel cell carcinomas lacking Merkel cell polyomavirus display distinct genetic changes from Merkel cell polyomavirus-positive Merkel cell carcinoma, including RB1 inactivating mutations. Unlike CK20-positive Merkel cell carcinoma, the majority of CK20-negative Merkel cell carcinomas are Merkel cell polyomavirus-negative, suggesting CK20-negative Merkel cell carcinomas predominantly arise through virus-independent pathway(s) and may harbor additional genetic differences from conventional Merkel cell carcinoma. Hence, we analyzed 15 CK20-negative Merkel cell carcinoma tumors (10 Merkel cell polyomavirus-negative, four Merkel cell polyomavirus-positive, and one undetermined) using the Ion Ampliseq Comprehensive Cancer Panel, which assesses copy number alterations and mutations in 409 cancer-relevant genes. Twelve tumors displayed prioritized high-level chromosomal gains or losses (average 1.9 per tumor). Non-synonymous high-confidence somatic mutations were detected in 14 tumors (average 11.9 per tumor). Assessing all somatic coding mutations, an ultraviolet-signature mutational profile was present, and more prevalent in Merkel cell polyomavirus-negative tumors. Recurrent deleterious tumor suppressor mutations affected TP53 (9/15, 60%), RB1 (3/15, 20%), and BAP1 (2/15, 13%). Oncogenic activating mutations included PIK3CA (3/15, 20%), AKT1 (1/15, 7%) and EZH2 (1/15, 7%). In conclusion, CK20-negative Merkel cell carcinoma display overlapping genetic changes

  7. Next Generation Sequencing of Cytokeratin 20-Negative Merkel Cell Carcinoma Reveals Ultraviolet Signature Mutations and Recurrent TP53 and RB1 Inactivation

    Science.gov (United States)

    Harms, Paul W.; Collie, Angela M. B.; Hovelson, Daniel H.; Cani, Andi K.; Verhaegen, Monique E.; Patel, Rajiv M.; Fullen, Douglas R.; Omata, Kei; Dlugosz, Andrzej A.; Tomlins, Scott A.; Billings, Steven D.

    2016-01-01

    Merkel cell carcinoma is a rare but highly aggressive cutaneous neuroendocrine carcinoma. Cytokeratin-20 (CK20) is expressed in approximately 95% of Merkel cell carcinomas and is useful for distinction from morphologically similar entities including metastatic small cell lung carcinoma. Lack of CK20 expression may make diagnosis of Merkel cell carcinoma more challenging, and has unknown biological significance. Approximately 80% of CK20-positive Merkel cell carcinomas are associated with the oncogenic Merkel cell polyomavirus. Merkel cell carcinomas lacking Merkel cell polyomavirus display distinct genetic changes from Merkel cell polyomavirus-positive Merkel cell carcinoma, including RB1 inactivating mutations. Unlike CK20-positive Merkel cell carcinoma, the majority of CK20-negative Merkel cell carcinomas are Merkel cell polyomavirus-negative, suggesting CK20-negative Merkel cell carcinomas predominantly arise through virus-independent pathway(s) and may harbor additional genetic differences from conventional Merkel cell carcinoma. Hence, we analyzed 15 CK20-negative Merkel cell carcinoma tumors (ten Merkel cell polyomavirus-negative, four Merkel cell polyomavirus-positive, and one undetermined) using the Ion Ampliseq Comprehensive Cancer Panel, which assesses copy number alterations and mutations in 409 cancer-relevant genes. Twelve tumors displayed prioritized high-level chromosomal gains or losses (average 1.9 per tumor). Non-synonymous high confidence somatic mutations were detected in 14 tumors (average 11.9 per tumor). Assessing all somatic coding mutations, an ultraviolet-signature mutational profile was present, and more prevalent in Merkel cell polyomavirus-negative tumors. Recurrent deleterious tumor suppressor mutations affected TP53 (9/15, 60%), RB1 (3/15, 20%), and BAP1 (2/15, 13%). Oncogenic activating mutations included PIK3CA (3/15, 20%), AKT1 (1/15, 7%)) and EZH2 (1/15, 7%). In conclusion, CK20-negative Merkel cell carcinoma display overlapping

  8. Mutation formation and inactivation of mammalian cells by heavy ions. 3

    International Nuclear Information System (INIS)

    Obaturov, G.M.

    1984-01-01

    Using parameter values of equations for cell inactivation cross-sections, theoretical curves were calculated for cell radiosensitivity (α 1 ) in dependence on LET. There is good agreement between calculated and experimental values of α 1 . The yield of lethal mutations of 1st and 2nd types and their sum in dependence on LET was also calculated. It was shown that for low LET ions cell radiosensitivity is caused by the 2nd type of mutation, independent of LET, proportional to DNA mass and inversely proportional to repair rate. For high LET ions when lethal mutation number per one track is more than one, α 1 is caused by the 1st type of mutation, proportional to cell nuclear cross-section and inversely proportional to LET. For intermediate LET ions α 1 is a complicated function of LET. It is follows from the equations that more than 17% of double strand breaks (DSB) take part in lethal mutation formation. Others are either repaired or formed in the process of experimentally determined DSB yield. (author)

  9. Somatic mutation load of estrogen receptor-positive breast tumors predicts overall survival: an analysis of genome sequence data.

    Science.gov (United States)

    Haricharan, Svasti; Bainbridge, Matthew N; Scheet, Paul; Brown, Powel H

    2014-07-01

    Breast cancer is one of the most commonly diagnosed cancers in women. While there are several effective therapies for breast cancer and important single gene prognostic/predictive markers, more than 40,000 women die from this disease every year. The increasing availability of large-scale genomic datasets provides opportunities for identifying factors that influence breast cancer survival in smaller, well-defined subsets. The purpose of this study was to investigate the genomic landscape of various breast cancer subtypes and its potential associations with clinical outcomes. We used statistical analysis of sequence data generated by the Cancer Genome Atlas initiative including somatic mutation load (SML) analysis, Kaplan-Meier survival curves, gene mutational frequency, and mutational enrichment evaluation to study the genomic landscape of breast cancer. We show that ER(+), but not ER(-), tumors with high SML associate with poor overall survival (HR = 2.02). Further, these high mutation load tumors are enriched for coincident mutations in both DNA damage repair and ER signature genes. While it is known that somatic mutations in specific genes affect breast cancer survival, this study is the first to identify that SML may constitute an important global signature for a subset of ER(+) tumors prone to high mortality. Moreover, although somatic mutations in individual DNA damage genes affect clinical outcome, our results indicate that coincident mutations in DNA damage response and signature ER genes may prove more informative for ER(+) breast cancer survival. Next generation sequencing may prove an essential tool for identifying pathways underlying poor outcomes and for tailoring therapeutic strategies.

  10. Pitfalls of improperly procured adjacent non-neoplastic tissue for somatic mutation analysis using next-generation sequencing

    Directory of Open Access Journals (Sweden)

    Lei Wei

    2016-10-01

    Full Text Available Abstract Background The rapid adoption of next-generation sequencing provides an efficient system for detecting somatic alterations in neoplasms. The detection of such alterations requires a matched non-neoplastic sample for adequate filtering of non-somatic events such as germline polymorphisms. Non-neoplastic tissue adjacent to the excised neoplasm is often used for this purpose as it is simultaneously collected and generally contains the same tissue type as the neoplasm. Following NGS analysis, we and others have frequently observed low-level somatic mutations in these non-neoplastic tissues, which may impose additional challenges to somatic mutation detection as it complicates germline variant filtering. Methods We hypothesized that the low-level somatic mutation observed in non-neoplastic tissues may be entirely or partially caused by inadvertent contamination by neoplastic cells during the surgical pathology gross assessment or tissue procurement process. To test this hypothesis, we applied a systematic protocol designed to collect multiple grossly non-neoplastic tissues using different methods surrounding each single neoplasm. The procedure was applied in two breast cancer lumpectomy specimens. In each case, all samples were first sequenced by whole-exome sequencing to identify somatic mutations in the neoplasm and determine their presence in the adjacent non-neoplastic tissues. We then generated ultra-deep coverage using targeted sequencing to assess the levels of contamination in non-neoplastic tissue samples collected under different conditions. Results Contamination levels in non-neoplastic tissues ranged up to 3.5 and 20.9 % respectively in the two cases tested, with consistent pattern correlated with the manner of grossing and procurement. By carefully controlling the conditions of various steps during this process, we were able to eliminate any detectable contamination in both patients. Conclusion The results demonstrated that the

  11. Effects of diurnal temperature difference and gamma radiation on the frequency of somatic cell mutations in the stamen hairs

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Kim, Won Rok; Kim, Jae Sung; Shin, Hae Shick; Lee, Jeong Joo

    1998-01-01

    This study deals with the effects of diurnal temperature difference (DTD) on somatic cell mutation frequencies in Tradescantia stamen hairs irradiated with radiation. Potted plants of Tradescantia 4430 were irradiated with 0.3, 0.5, 1.0 and 2.0 Gy of gamma radiation. The irradiated plants were maintained under two different experimental conditions; at constant temperature of 20 degree C (DTD0) and at 28 degree C for 14-h day and 8 degree C for 10-h night (DTD20). The somatic cell mutation rate in 0.5 Gy irradiated group showed a big increase on the 6th day and reached a maximum value on the 10th day after irradiation while the rate in the experimental group under the condition of DTD20 started to increase on the 8th day and got to a maximal value on the 14th day postirradiation. In both of the two experiments, the dose-response relationships were clearly linear. The slope of the DTD20 dose-response curve was much steeper than that of the DTD0 one. In conclusion, a great DTD, as one of environmental stresses, enhanced the effectiveness of radiation in the induction of somatic cell mutations and caused a shift of the peak interval of radiation-induced mutations in Tradescantia stamen hairs

  12. Homozygous Inactivating Mutation in NANOS3 in Two Sisters with Primary Ovarian Insufficiency

    Directory of Open Access Journals (Sweden)

    Mariza G. Santos

    2014-01-01

    Full Text Available Despite the increasing understanding of female reproduction, the molecular diagnosis of primary ovarian insufficiency (POI is seldom obtained. The RNA-binding protein NANOS3 poses as an interesting candidate gene for POI since members of the Nanos family have an evolutionarily conserved function in germ cell development and maintenance by repressing apoptosis. We performed mutational analysis of NANOS3 in a cohort of 85 Brazilian women with familial or isolated POI, presenting with primary or secondary amenorrhea, and in ethnically-matched control women. A homozygous p.Glu120Lys mutation in NANOS3 was identified in two sisters with primary amenorrhea. The substituted amino acid is located within the second C2HC motif in the conserved zinc finger domain of NANOS3 and in silico molecular modelling suggests destabilization of protein-RNA interaction. In vitro analyses of apoptosis through flow cytometry and confocal microscopy show that NANOS3 capacity to prevent apoptosis was impaired by this mutation. The identification of an inactivating missense mutation in NANOS3 suggests a mechanism for POI involving increased primordial germ cells (PGCs apoptosis during embryonic cell migration and highlights the importance of NANOS proteins in human ovarian biology.

  13. Somatic HLA mutations expose the role of class I–mediated autoimmunity in aplastic anemia and its clonal complications

    Science.gov (United States)

    Duke, Jamie L.; Xie, Hongbo M.; Stanley, Natasha; Atienza, Jamie; Perdigones, Nieves; Nicholas, Peter; Ferriola, Deborah; Li, Yimei; Huang, Hugh; Ye, Wenda; Morrissette, Jennifer J. D.; Kearns, Jane; Porter, David L.; Podsakoff, Gregory M.; Eisenlohr, Laurence C.; Biegel, Jaclyn A.; Chou, Stella T.; Monos, Dimitrios S.; Bessler, Monica; Olson, Timothy S.

    2017-01-01

    Acquired aplastic anemia (aAA) is an acquired deficiency of early hematopoietic cells, characterized by inadequate blood production, and a predisposition to myelodysplastic syndrome (MDS) and leukemia. Although its exact pathogenesis is unknown, aAA is thought to be driven by human leukocyte antigen (HLA)–restricted T cell immunity, with earlier studies favoring HLA class II-mediated pathways. Using whole-exome sequencing (WES), we recently identified 2 patients with aAA with somatic mutations in HLA class I genes. We hypothesized that HLA class I mutations are pathognomonic for autoimmunity in aAA, but were previously underappreciated because the major histocompatibility complex (MHC) region is notoriously difficult to analyze by WES. Using a combination of targeted deep sequencing of HLA class I genes and single nucleotide polymorphism array (SNP-A) genotyping, we screened 66 patients with aAA for somatic HLA class I loss. We found somatic HLA loss in 11 patients (17%), with 13 loss-of-function mutations in HLA-A*33:03, HLA-A*68:01, HLA-B*14:02, and HLA-B*40:02 alleles. Three patients had more than 1 mutation targeting the same HLA allele. Interestingly, HLA-B*14:02 and HLA-B*40:02 were significantly overrepresented in patients with aAA compared with ethnicity-matched controls. Patients who inherited the targeted HLA alleles, regardless of HLA mutation status, had a more severe disease course with more frequent clonal complications as assessed by WES, SNP-A, and metaphase cytogenetics, and more frequent secondary MDS. The finding of recurrent HLA class I mutations provides compelling evidence for a predominant HLA class I-driven autoimmunity in aAA and establishes a novel link between immunogenetics and clonal evolution of patients with aAA. PMID:28971166

  14. Somatic HLA Mutations Expose the Role of Class I-Mediated Autoimmunity in Aplastic Anemia and its Clonal Complications.

    Science.gov (United States)

    Babushok, Daria V; Duke, Jamie L; Xie, Hongbo M; Stanley, Natasha; Atienza, Jamie; Perdigones, Nieves; Nicholas, Peter; Ferriola, Deborah; Li, Yimei; Huang, Hugh; Ye, Wenda; Morrissette, Jennifer J D; Kearns, Jane; Porter, David L; Podsakoff, Gregory M; Eisenlohr, Laurence C; Biegel, Jaclyn A; Chou, Stella T; Monos, Dimitrios S; Bessler, Monica; Olson, Timothy S

    2017-10-10

    Acquired aplastic anemia (aAA) is an acquired deficiency of early hematopoietic cells, characterized by inadequate blood production, and a predisposition to myelodysplastic syndrome (MDS) and leukemia. Although its exact pathogenesis is unknown, aAA is thought to be driven by Human Leukocyte Antigen (HLA)-restricted T cell immunity, with earlier studies favoring HLA class II-mediated pathways. Using whole exome sequencing (WES), we recently identified two aAA patients with somatic mutations in HLA class I genes. We hypothesized that HLA class I mutations are pathognomonic for autoimmunity in aAA, but were previously underappreciated because the Major Histocompatibility Complex (MHC) region is notoriously difficult to analyze by WES. Using a combination of targeted deep sequencing of HLA class I genes and single nucleotide polymorphism array (SNP-A) genotyping we screened 66 aAA patients for somatic HLA class I loss. We found somatic HLA loss in eleven patients (17%), with thirteen loss-of-function mutations in HLA-A *33:03, HLA-A *68:01, HLA-B *14:02 and HLA-B *40:02 alleles. Three patients had more than one mutation targeting the same HLA allele. Interestingly, HLA-B *14:02 and HLA-B *40:02 were significantly overrepresented in aAA patients, compared to ethnicity-matched controls. Patients who inherited the targeted HLA alleles, regardless of HLA mutation status, had a more severe disease course with more frequent clonal complications as assessed by WES, SNP-A, and metaphase cytogenetics, and more frequent secondary MDS. The finding of recurrent HLA class I mutations provides compelling evidence for a predominant HLA class I-driven autoimmunity in aAA, and establishes a novel link between aAA patients' immunogenetics and clonal evolution.

  15. Germline and somatic polymerase ε and δ mutations define a new class of hypermutated colorectal and endometrial cancers.

    Science.gov (United States)

    Briggs, Sarah; Tomlinson, Ian

    2013-06-01

    Polymerases ε and δ are the main enzymes that replicate eukaryotic DNA. Accurate replication occurs through Watson-Crick base pairing and also through the action of the polymerases' exonuclease (proofreading) domains. We have recently shown that germline exonuclease domain mutations (EDMs) of POLE and POLD1 confer a high risk of multiple colorectal adenomas and carcinoma (CRC). POLD1 mutations also predispose to endometrial cancer (EC). These mutations are associated with high penetrance and dominant inheritance, although the phenotype can be variable. We have named the condition polymerase proofreading-associated polyposis (PPAP). Somatic POLE EDMs have also been found in sporadic CRCs and ECs, although very few somatic POLD1 EDMs have been detected. Both the germline and the somatic DNA polymerase EDMs cause an 'ultramutated', apparently microsatellite-stable, type of cancer, sometimes leading to over a million base substitutions per tumour. Here, we present the evidence for POLE and POLD1 as important contributors to the pathogenesis of CRC and EC, and highlight some of the key questions in this emerging field. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  16. Novel somatic mutations in large granular lymphocytic leukemia affecting the STAT-pathway and T-cell activation

    International Nuclear Information System (INIS)

    Andersson, E I; Rajala, H L M; Eldfors, S; Ellonen, P; Olson, T; Jerez, A; Clemente, M J; Kallioniemi, O; Porkka, K; Heckman, C; Loughran, T P Jr; Maciejewski, J P; Mustjoki, S

    2013-01-01

    T-cell large granular lymphocytic (T-LGL) leukemia is a clonal disease characterized by the expansion of mature CD3+CD8+ cytotoxic T cells. It is often associated with autoimmune disorders and immune-mediated cytopenias. Our recent findings suggest that up to 40% of T-LGL patients harbor mutations in the STAT3 gene, whereas STAT5 mutations are present in 2% of patients. In order to identify putative disease-causing genetic alterations in the remaining T-LGL patients, we performed exome sequencing from three STAT mutation-negative patients and validated the findings in 113 large granular lymphocytic (LGL) leukemia patients. On average, 11 CD8+ LGL leukemia cell-specific high-confidence nonsynonymous somatic mutations were discovered in each patient. Interestingly, all patients had at least one mutation that affects either directly the STAT3-pathway (such as PTPRT) or T-cell activation (BCL11B, SLIT2 and NRP1). In all three patients, the STAT3 pathway was activated when studied by RNA expression or pSTAT3 analysis. Screening of the remaining 113 LGL leukemia patients did not reveal additional patients with same mutations. These novel mutations are potentially biologically relevant and represent rare genetic triggers for T-LGL leukemia, and are associated with similar disease phenotype as observed in patients with mutations in the STAT3 gene

  17. Inactivation and mutation of cultured mammalian cells by aluminium characteristic ultrasoft X-rays

    International Nuclear Information System (INIS)

    Goodhead, D.T.

    1977-01-01

    Microdosimetric distributions for aluminium K characteristic ultrasoft X-rays and 4 He ion track intersections have been calculated and used to analyse recent biological results obtained with these radiations. Results on inactivation and mutation-induction to thioguanine resistance of both V79 Chinese hamster cells and HF19 human diploid fibroblasts in vitro were analysed in terms of the Kellerer-Rossi 'theory of dual radiation action'. The small quantum energy of the aluminium X-ray photons and the very short length of the secondary electrons which they produce highlight the inadequacy of the model. It has been shown that the model predicted r.b.e. values in conflict with those observed unless an additional variable was introduced, but that the introduction of such a variable created mathematical inconsistencies. The experimental evidence is contrary to the conventional usage and basis of the model. (author)

  18. MPLW515L is a novel somatic activating mutation in myelofibrosis with myeloid metaplasia.

    Science.gov (United States)

    Pikman, Yana; Lee, Benjamin H; Mercher, Thomas; McDowell, Elizabeth; Ebert, Benjamin L; Gozo, Maricel; Cuker, Adam; Wernig, Gerlinde; Moore, Sandra; Galinsky, Ilene; DeAngelo, Daniel J; Clark, Jennifer J; Lee, Stephanie J; Golub, Todd R; Wadleigh, Martha; Gilliland, D Gary; Levine, Ross L

    2006-07-01

    The JAK2V617F allele has recently been identified in patients with polycythemia vera (PV), essential thrombocytosis (ET), and myelofibrosis with myeloid metaplasia (MF). Subsequent analysis has shown that constitutive activation of the JAK-STAT signal transduction pathway is an important pathogenetic event in these patients, and that enzymatic inhibition of JAK2V617F may be of therapeutic benefit in this context. However, a significant proportion of patients with ET or MF are JAK2V617F-negative. We hypothesized that activation of the JAK-STAT pathway might also occur as a consequence of activating mutations in certain hematopoietic-specific cytokine receptors, including the erythropoietin receptor (EPOR), the thrombopoietin receptor (MPL), or the granulocyte-colony stimulating factor receptor (GCSFR). DNA sequence analysis of the exons encoding the transmembrane and juxtamembrane domains of EPOR, MPL, and GCSFR, and comparison with germline DNA derived from buccal swabs, identified a somatic activating mutation in the transmembrane domain of MPL (W515L) in 9% (4/45) of JAKV617F-negative MF. Expression of MPLW515L in 32D, UT7, or Ba/F3 cells conferred cytokine-independent growth and thrombopoietin hypersensitivity, and resulted in constitutive phosphorylation of JAK2, STAT3, STAT5, AKT, and ERK. Furthermore, a small molecule JAK kinase inhibitor inhibited MPLW515L-mediated proliferation and JAK-STAT signaling in vitro. In a murine bone marrow transplant assay, expression of MPLW515L, but not wild-type MPL, resulted in a fully penetrant myeloproliferative disorder characterized by marked thrombocytosis (Plt count 1.9-4.0 x 10(12)/L), marked splenomegaly due to extramedullary hematopoiesis, and increased reticulin fibrosis. Activation of JAK-STAT signaling via MPLW515L is an important pathogenetic event in patients with JAK2V617F-negative MF. The bone marrow transplant model of MPLW515L-mediated myeloproliferative disorders (MPD) exhibits certain features of human MF

  19. MPLW515L is a novel somatic activating mutation in myelofibrosis with myeloid metaplasia.

    Directory of Open Access Journals (Sweden)

    Yana Pikman

    2006-07-01

    Full Text Available The JAK2V617F allele has recently been identified in patients with polycythemia vera (PV, essential thrombocytosis (ET, and myelofibrosis with myeloid metaplasia (MF. Subsequent analysis has shown that constitutive activation of the JAK-STAT signal transduction pathway is an important pathogenetic event in these patients, and that enzymatic inhibition of JAK2V617F may be of therapeutic benefit in this context. However, a significant proportion of patients with ET or MF are JAK2V617F-negative. We hypothesized that activation of the JAK-STAT pathway might also occur as a consequence of activating mutations in certain hematopoietic-specific cytokine receptors, including the erythropoietin receptor (EPOR, the thrombopoietin receptor (MPL, or the granulocyte-colony stimulating factor receptor (GCSFR.DNA sequence analysis of the exons encoding the transmembrane and juxtamembrane domains of EPOR, MPL, and GCSFR, and comparison with germline DNA derived from buccal swabs, identified a somatic activating mutation in the transmembrane domain of MPL (W515L in 9% (4/45 of JAKV617F-negative MF. Expression of MPLW515L in 32D, UT7, or Ba/F3 cells conferred cytokine-independent growth and thrombopoietin hypersensitivity, and resulted in constitutive phosphorylation of JAK2, STAT3, STAT5, AKT, and ERK. Furthermore, a small molecule JAK kinase inhibitor inhibited MPLW515L-mediated proliferation and JAK-STAT signaling in vitro. In a murine bone marrow transplant assay, expression of MPLW515L, but not wild-type MPL, resulted in a fully penetrant myeloproliferative disorder characterized by marked thrombocytosis (Plt count 1.9-4.0 x 10(12/L, marked splenomegaly due to extramedullary hematopoiesis, and increased reticulin fibrosis.Activation of JAK-STAT signaling via MPLW515L is an important pathogenetic event in patients with JAK2V617F-negative MF. The bone marrow transplant model of MPLW515L-mediated myeloproliferative disorders (MPD exhibits certain features of

  20. Immunohistochemical loss of 5-hydroxymethylcytosine expression in acute myeloid leukaemia: relationship to somatic gene mutations affecting epigenetic pathways.

    Science.gov (United States)

    Magotra, Minoti; Sakhdari, Ali; Lee, Paul J; Tomaszewicz, Keith; Dresser, Karen; Hutchinson, Lloyd M; Woda, Bruce A; Chen, Benjamin J

    2016-12-01

    Genes affecting epigenetic pathways are frequently mutated in myeloid malignancies, including acute myeloid leukaemia (AML). The genes encoding TET2, IDH1 and IDH2 are among the most commonly mutated genes, and cause defective conversion of 5-methylcytosine into 5-hydroxymethylcytosine (5hmC), impairing demethylation of DNA, and presumably serving as driver mutations in leukaemogenesis. The aim of this study was to correlate 5hmC immunohistochemical loss with the mutation status of genes involved in epigenetic pathways in AML. Immunohistochemical staining with an anti-5hmC antibody was performed on 41 decalcified, formalin-fixed paraffin-embedded (FFPE) bone marrow biopsies from patients with AML. Archived DNA was subjected to next-generation sequencing for analysis of a panel of genes, including TET2, IDH1, IDH2, WT1 and DNMT3A. TET2, IDH1, IDH2, WT1 and DNMT3A mutations were found in 46% (19/41) of the cases. Ten of 15 cases (67%) with TET2, IDH1, IDH2 or WT1 mutations showed deficient 5hmC staining, whereas nine of 26 cases (35%) without a mutation in these genes showed loss of 5hmC. It is of note that all four cases with TET2 mutations showed deficient 5hmC staining. Overall, somatic mutations in TET2, IDH1, IDH2, WT1 and DNMT3A were common in our cohort of AML cases. Immunohistochemical staining for 5hmC was lost in the majority of cases harbouring mutations in these genes, reflecting the proposed relationship between dysfunctional epigenetic pathways and leukaemogenesis. © 2016 John Wiley & Sons Ltd.

  1. The uranyl influence on a mutation process in germ and somatic cells of mice

    International Nuclear Information System (INIS)

    Kostrova, L.N.; Mosseh, I.B.; Molofej, V.P.

    2008-01-01

    The mutagenic effect of uranyl was revealed by the chromosome rearrangement test in germ and somatic cells of mice. The effect value depended on duration of substance administration into organism. (authors)

  2. Impact of Somatic Mutations in the D-Loop of Mitochondrial DNA on the Survival of Oral Squamous Cell Carcinoma Patients

    Science.gov (United States)

    Lin, Jin-Ching; Wang, Chen-Chi; Jiang, Rong-San; Wang, Wen-Yi; Liu, Shih-An

    2015-01-01

    Objectives The aim of this study was to investigate somatic mutations in the D-loop of mitochondrial DNA (mtDNA) and their impact on survival in oral squamous cell carcinoma patients. Materials and Methods Surgical specimen confirmed by pathological examination and corresponding non-cancerous tissues were collected from 120 oral squamous cell carcinoma patients. The sequence in the D-loop of mtDNA from non-cancerous tissues was compared with that from paired cancer samples and any sequence differences were recognized as somatic mutations. Results Somatic mutations in the D-loop of mtDNA were identified in 75 (62.5%) oral squamous cell carcinoma patients and most of them occurred in the poly-C tract. Although there were no significant differences in demographic and tumor-related features between participants with and without somatic mutation, the mutation group had a better survival rate (5 year disease-specific survival rate: 64.0% vs. 43.0%, P = 0.0266). Conclusion Somatic mutation in D-loop of mtDNA was associated with a better survival in oral squamous cell carcinoma patients. PMID:25906372

  3. Somatic point mutations in mtDNA control region are influenced by genetic background and associated with healthy aging: a GEHA study

    DEFF Research Database (Denmark)

    Rose, Giuseppina; Romeo, Giuseppe; Dato, Serena

    2010-01-01

    and of mortality risk in the elderly. Our study provides new evidence on the relevance of mtDNA somatic mutations in aging and longevity and confirms that the occurrence of specific point mutations in the mtDNA control region may represent a strategy for the age-related remodelling of organismal functions....

  4. Somatic mosaicism for the COL7A1 mutation p.Gly2034Arg in the unaffected mother of a patient with dystrophic epidermolysis bullosa pruriginosa

    NARCIS (Netherlands)

    van den Akker, P. C.; Pasmooij, A. M. G.; Meijer, R.; Scheffer, H.; Jonkman, M. F.

    Dystrophic epidermolysis bullosa (DEB) is a heritable blistering disorder caused by mutations in the type VII collagen gene, COL7A1. Although revertant mosaicism is well known in DEB, 'forward' somatic mosaicism, in which a pathogenic mutation arises on a wild-type (WT) background, extending beyond

  5. Somatic mosaicism for the COL7A1 mutation p.Gly2034Arg in the unaffected mother of a patient with dystrophic epidermolysis bullosa pruriginosa

    NARCIS (Netherlands)

    Akker, P.C. van den; Pasmooij, A.M.; Meijer, R.; Scheffer, H.; Jonkman, M.F.

    2015-01-01

    Dystrophic epidermolysis bullosa (DEB) is a heritable blistering disorder caused by mutations in the type VII collagen gene, COL7A1. Although revertant mosaicism is well known in DEB, 'forward' somatic mosaicism, in which a pathogenic mutation arises on a wild-type (WT) background, extending beyond

  6. An integrated inspection of the somatic mutations in a lung squamous cell carcinoma using next-generation sequencing.

    Directory of Open Access Journals (Sweden)

    Lucy F Stead

    Full Text Available Squamous cell carcinoma (SCC of the lung kills over 350,000 people annually worldwide, and is the main lung cancer histotype with no targeted treatments. High-coverage whole-genome sequencing of the other main subtypes, small-cell and adenocarcinoma, gave insights into carcinogenic mechanisms and disease etiology. The genomic complexity within the lung SCC subtype, as revealed by The Cancer Genome Atlas, means this subtype is likely to benefit from a more integrated approach in which the transcriptional consequences of somatic mutations are simultaneously inspected. Here we present such an approach: the integrated analysis of deep sequencing data from both the whole genome and whole transcriptome (coding and non-coding of LUDLU-1, a SCC lung cell line. Our results show that LUDLU-1 lacks the mutational signature that has been previously associated with tobacco exposure in other lung cancer subtypes, and suggests that DNA-repair efficiency is adversely affected; LUDLU-1 contains somatic mutations in TP53 and BRCA2, allelic imbalance in the expression of two cancer-associated BRCA1 germline polymorphisms and reduced transcription of a potentially endogenous PARP2 inhibitor. Functional assays were performed and compared with a control lung cancer cell line. LUDLU-1 did not exhibit radiosensitisation or an increase in sensitivity to PARP inhibitors. However, LUDLU-1 did exhibit small but significant differences with respect to cisplatin sensitivity. Our research shows how integrated analyses of high-throughput data can generate hypotheses to be tested in the lab.

  7. Accelerated inactivation of the L-type calcium current due to a mutation in CACNB2b underlies Brugada syndrome

    DEFF Research Database (Denmark)

    Cordeiro, Jonathan M; Marieb, Mark; Pfeiffer, Ryan

    2009-01-01

    S in which loss of function is caused by accelerated inactivation of I(Ca). The proband, a 32 year old male, displayed a Type I ST segment elevation in two right precordial ECG leads following a procainamide challenge. EP study was positive with induction of polymorphic VT/VF. Interrogation of implanted ICD...... significantly faster in mutant channels between 0 and + 20 mV. Action potential voltage clamp experiments showed that total charge was reduced by almost half compared to WT. We report the first BrS mutation in CaCNB2b resulting in accelerated inactivation of L-type calcium channel current. Our results suggest...

  8. Somatic mutation profiles of MSI and MSS colorectal cancer identified by whole exome next generation sequencing and bioinformatics analysis.

    Directory of Open Access Journals (Sweden)

    Bernd Timmermann

    Full Text Available BACKGROUND: Colorectal cancer (CRC is with approximately 1 million cases the third most common cancer worldwide. Extensive research is ongoing to decipher the underlying genetic patterns with the hope to improve early cancer diagnosis and treatment. In this direction, the recent progress in next generation sequencing technologies has revolutionized the field of cancer genomics. However, one caveat of these studies remains the large amount of genetic variations identified and their interpretation. METHODOLOGY/PRINCIPAL FINDINGS: Here we present the first work on whole exome NGS of primary colon cancers. We performed 454 whole exome pyrosequencing of tumor as well as adjacent not affected normal colonic tissue from microsatellite stable (MSS and microsatellite instable (MSI colon cancer patients and identified more than 50,000 small nucleotide variations for each tissue. According to predictions based on MSS and MSI pathomechanisms we identified eight times more somatic non-synonymous variations in MSI cancers than in MSS and we were able to reproduce the result in four additional CRCs. Our bioinformatics filtering approach narrowed down the rate of most significant mutations to 359 for MSI and 45 for MSS CRCs with predicted altered protein functions. In both CRCs, MSI and MSS, we found somatic mutations in the intracellular kinase domain of bone morphogenetic protein receptor 1A, BMPR1A, a gene where so far germline mutations are associated with juvenile polyposis syndrome, and show that the mutations functionally impair the protein function. CONCLUSIONS/SIGNIFICANCE: We conclude that with deep sequencing of tumor exomes one may be able to predict the microsatellite status of CRC and in addition identify potentially clinically relevant mutations.

  9. SMARCA4 inactivating mutations cause concomitant Coffin–Siris syndrome, microphthalmia and small‐cell carcinoma of the ovary hypercalcaemic type

    Science.gov (United States)

    Mustafa, Noor; Vetro, Annalisa; Notarangelo, Lucia Dora; de Jonge, Hugo; Rinaldi, Berardo; Vergani, Debora; Giglio, Sabrina Rita; Morbini, Patrizia; Zuffardi, Orsetta

    2017-01-01

    Abstract SMARCA4 chromatin remodelling factor is mutated in 11% of Coffin–Siris syndrome (CSS) patients and in almost all small‐cell carcinoma of the ovary hypercalcaemic type (SCCOHT) tumours. Missense mutations with gain‐of‐function or dominant‐negative effects are associated with CSS, whereas inactivating mutations, leading to loss of SMARCA4 expression, have been exclusively found in SCCOHT. We applied whole‐exome sequencing to study a 15‐year‐old patient with mild CSS who concomitantly developed SCCOHT at age 13 years. Interestingly, our patient also showed congenital microphthalmia, which has never previously been reported in CSS patients. We detected a de novo germline heterozygous nonsense mutation in exon 19 of SMARCA4 (c.2935C > T;p.Arg979*), and a somatic frameshift mutation in exon 6 (c.1236_1236delC;p.Gln413Argfs*88), causing complete loss of SMARCA4 immunostaining in the tumour. The immunohistochemical findings are supported by the observation that the c.2935C > T mutant transcript was detected by reverse transcription polymerase chain reaction at a much lower level than the wild‐type allele in whole blood and the lymphoblastoid cell line of the proband, confirming nonsense‐mediated mRNA decay. Accordingly, immunoblotting demonstrated that there was approximately half the amount of SMARCA4 protein in the proband's cells as in controls. This study suggests that SMARCA4 constitutional mutations associated with CSS are not necessarily non‐truncating, and that haploinsufficiency may explain milder CSS phenotypes, as previously reported for haploinsufficient ARID1B. In addition, our case supports the dual role of chromatin remodellers in developmental disorders and cancer, as well as the involvement of SMARCA4 in microphthalmia, confirming previous findings in mouse models and the DECIPHER database. Finally, we speculate that mild CSS might be under‐recognized in a proportion of SCCOHT patients harbouring SMARCA4 mutations

  10. SMARCA4 inactivating mutations cause concomitant Coffin-Siris syndrome, microphthalmia and small-cell carcinoma of the ovary hypercalcaemic type.

    Science.gov (United States)

    Errichiello, Edoardo; Mustafa, Noor; Vetro, Annalisa; Notarangelo, Lucia Dora; de Jonge, Hugo; Rinaldi, Berardo; Vergani, Debora; Giglio, Sabrina Rita; Morbini, Patrizia; Zuffardi, Orsetta

    2017-09-01

    SMARCA4 chromatin remodelling factor is mutated in 11% of Coffin-Siris syndrome (CSS) patients and in almost all small-cell carcinoma of the ovary hypercalcaemic type (SCCOHT) tumours. Missense mutations with gain-of-function or dominant-negative effects are associated with CSS, whereas inactivating mutations, leading to loss of SMARCA4 expression, have been exclusively found in SCCOHT. We applied whole-exome sequencing to study a 15-year-old patient with mild CSS who concomitantly developed SCCOHT at age 13 years. Interestingly, our patient also showed congenital microphthalmia, which has never previously been reported in CSS patients. We detected a de novo germline heterozygous nonsense mutation in exon 19 of SMARCA4 (c.2935C > T;p.Arg979*), and a somatic frameshift mutation in exon 6 (c.1236_1236delC;p.Gln413Argfs*88), causing complete loss of SMARCA4 immunostaining in the tumour. The immunohistochemical findings are supported by the observation that the c.2935C > T mutant transcript was detected by reverse transcription polymerase chain reaction at a much lower level than the wild-type allele in whole blood and the lymphoblastoid cell line of the proband, confirming nonsense-mediated mRNA decay. Accordingly, immunoblotting demonstrated that there was approximately half the amount of SMARCA4 protein in the proband's cells as in controls. This study suggests that SMARCA4 constitutional mutations associated with CSS are not necessarily non-truncating, and that haploinsufficiency may explain milder CSS phenotypes, as previously reported for haploinsufficient ARID1B. In addition, our case supports the dual role of chromatin remodellers in developmental disorders and cancer, as well as the involvement of SMARCA4 in microphthalmia, confirming previous findings in mouse models and the DECIPHER database. Finally, we speculate that mild CSS might be under-recognized in a proportion of SCCOHT patients harbouring SMARCA4 mutations. © 2017 The Authors. The

  11. Simultaneous DNA and RNA mapping of somatic mitochondrial mutations across diverse human cancers

    DEFF Research Database (Denmark)

    Stewart, James B.; Alaei-Mahabadi, Babak; Radhakrishnan, Sabarinathan

    2015-01-01

    of evidence from both genomic and transcriptomic sequencing. We find that there is selective pressure against deleterious coding mutations, supporting that functional mitochondria are required in tumor cells, and also observe a strong mutational strand bias, compatible with endogenous replication...

  12. TumorTracer: a method to identify the tissue of origin from the somatic mutations of a tumor specimen

    DEFF Research Database (Denmark)

    Marquard, Andrea Marion; Birkbak, Nicolai Juul; Thomas, Cecilia Engel

    2015-01-01

    A substantial proportion of cancer cases present with a metastatic tumor and require further testing to determine the primary site; many of these are never fully diagnosed and remain cancer of unknown primary origin (CUP). It has been previously demonstrated that the somatic point mutations......-copy-number classifier on three independent data sets: 1669 newly available public tumors of various types, a cohort of 91 breast metastases, and a set of 24 specimens from 9 lung cancer patients subjected to multiregion sequencing. The cross-validation accuracy was highest when all three types of information were used...... detected in a tumor can be used to identify its site of origin with limited accuracy. We hypothesized that higher accuracy could be achieved by a classification algorithm based on the following feature sets: 1) the number of nonsynonymous point mutations in a set of 232 specific cancer-associated genes, 2...

  13. Comparison of somatic mutation frequencies at HGPRT locus induced by radiation and chemical pollutant from energy system

    International Nuclear Information System (INIS)

    Xu Honglan; Cao Yi; Duan Zhikai; Wu Qiqing; Chen Ying; Zhang Shuxian

    1998-12-01

    The somatic induction frequencies of mutation at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus induced by 60 Co γ-rays and Benzo-a-pyrene (B(a)P), which are representative of hazardous emission and pollutant from nuclear energy cycle and fossil-fuelled energy cycle respectively, were detected by using forward mutation assay and cloning technique in both V 79 Chinese hamster cells and human peripheral blood T-lymphocytes. Resistant mutants were selected with 6-thioguanine (6-TG). Dose-response curves and mathematical expressions were obtained for mutation frequencies and survival following γ-ray and B(a)P(+S 9 ) treatments. The dose ranges for the two mutagens were compared when they induced the same mutation frequencies. In V 79 /HGPRT assay system, when the mutation frequencies were 5∼35 mutants/10 6 cells the response of γ-rays in the dose range from 0.93∼4.96 Gy at dose rate of 1.16 Gy/min is nearly equivalent to that in the B(a)P dose range from 0.52∼4.27 μg/ml. By using cloning technique in T-lymphocytes, when the mutation frequencies were 1∼14 mutants/10 5 cells the response of γ-rays in the dose range from 0.05∼4.77 Gy at dose rate of 1.03 Gy/min is nearly equivalent to that in the B(a)P dose range from 0.15∼7.36 μg/ml. When the survival fraction is 37%, the mutation frequency induced by B(a)P is higher than that induced by 60 Co γ-rays

  14. Bimodal voltage dependence of TRPA1: mutations of a key pore helix residue reveal strong intrinsic voltage-dependent inactivation.

    Science.gov (United States)

    Wan, Xia; Lu, Yungang; Chen, Xueqin; Xiong, Jian; Zhou, Yuanda; Li, Ping; Xia, Bingqing; Li, Min; Zhu, Michael X; Gao, Zhaobing

    2014-07-01

    Transient receptor potential A1 (TRPA1) is implicated in somatosensory processing and pathological pain sensation. Although not strictly voltage-gated, ionic currents of TRPA1 typically rectify outwardly, indicating channel activation at depolarized membrane potentials. However, some reports also showed TRPA1 inactivation at high positive potentials, implicating voltage-dependent inactivation. Here we report a conserved leucine residue, L906, in the putative pore helix, which strongly impacts the voltage dependency of TRPA1. Mutation of the leucine to cysteine (L906C) converted the channel from outward to inward rectification independent of divalent cations and irrespective to stimulation by allyl isothiocyanate. The mutant, but not the wild-type channel, displayed exclusively voltage-dependent inactivation at positive potentials. The L906C mutation also exhibited reduced sensitivity to inhibition by TRPA1 blockers, HC030031 and ruthenium red. Further mutagenesis of the leucine to all natural amino acids individually revealed that most substitutions at L906 (15/19) resulted in inward rectification, with exceptions of three amino acids that dramatically reduced channel activity and one, methionine, which mimicked the wild-type channel. Our data are plausibly explained by a bimodal gating model involving both voltage-dependent activation and inactivation of TRPA1. We propose that the key pore helix residue, L906, plays an essential role in responding to the voltage-dependent gating.

  15. Analysis of genotoxic activity of ketamine and rocuronium bromide using the somatic mutation and recombination test in Drosophila melanogaster.

    Science.gov (United States)

    Koksal, Pakize Muge; Gürbüzel, Mehmet

    2015-03-01

    The present study evaluated the mutagenic and recombinogenic effects of two commonly used anesthetic agents, ketamine and rocuronium bromide, in medicine using the wing somatic mutation and recombination test (SMART) in Drosophila. The standard (ST) cross and the high-bioactivation (HB) cross with high sensitivity to procarcinogens and promutagens were used. The SMART test is based on the loss of heterozygosity, which occurs via various mechanisms, such as chromosome loss and deletion, half-translocation, mitotic recombination, mutation, and non-disjunction. Genetic alterations occurring in the somatic cells of the wing's imaginal discs result in mutant clones in the wing blade. Three-day-old trans-heterozygous larvae with two recessive markers, multiple wing hairs (mwh) and flare (flr(3)), were treated with ketamine and rocuronium bromide. Analysis of the ST cross indicated that ketamine exhibited genotoxicity activity and that this activity was particularly dependent on homologous mitotic recombination at concentrations of 250 μg/ml and above. Rocuronium bromide did not exert mutagenic and/or recombinogenic effects. In the HB cross, ketamine at a concentration of 1000 μg/ml and rocuronium bromide at all concentrations, with the exception of 250 μg/ml (inconclusive), exerted genotoxic effects, which could also be associated with the increase in mitotic recombination. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Mutational pattern of the nurse shark antigen receptor gene (NAR) is similar to that of mammalian Ig genes and to spontaneous mutations in evolution: the translesion synthesis model of somatic hypermutation.

    Science.gov (United States)

    Diaz, M; Velez, J; Singh, M; Cerny, J; Flajnik, M F

    1999-05-01

    The pattern of somatic mutations of shark and frog Ig is distinct from somatic hypermutation of Ig in mammals in that there is a bias to mutate GC base pairs and a low frequency of mutations. Previous analysis of the new antigen receptor gene in nurse sharks (NAR), however, revealed no bias to mutate GC base pairs and the frequency of mutation was comparable to that of mammalian IgG. Here, we analyzed 1023 mutations in NAR and found no targeting of the mechanism to any particular nucleotide but did obtain strong evidence for a transition bias and for strand polarity. As seen for all species studied to date, the serine codon AGC/T in NAR was a mutational hotspot. The NAR mutational pattern is most similar to that of mammalian IgG and furthermore both are strikingly akin to mutations acquired during the neutral evolution of nuclear pseudogenes, suggesting that a similar mechanism is at work for both processes. In yeast, most spontaneous mutations are introduced by the translesion synthesis DNA polymerase zeta (REV3) and in various DNA repair-deficient backgrounds transitions were more often REV3-dependent than were transversions. Therefore, we propose a model of somatic hypermutation where DNA polymerase zeta is recruited to the Ig locus. An excess of DNA glycosylases in germinal center reactions may further enhance the mutation frequency by a REV3-dependent mutagenic process known as imbalanced base excision repair.

  17. Somatic mutation and recombination induced by fast neutrons in the wing spot test of Drosophila Melanogaster

    International Nuclear Information System (INIS)

    Guzman R, J.; Varela, A.; Policroniades, R.; Delfin, A.; Graf, U.

    1994-01-01

    In the last decades, a large number of studies have been undertaken to evaluate the biological effects of gamma and X rays in Drosophila melanogaster. The majority of these investigations were performed on female and male germ cells. However, comparatively little is known in relation to the biological effects of fast neutrons, and especially in relation to their effects in somatic cells. (Author)

  18. A Threshold Exists in the Dose-response Relationship for Somatic Mutation Frequency Inducted by X-ray Irradiation of Drosophia

    International Nuclear Information System (INIS)

    Koana, T.; Takashima, Y.; Okada, M. O.; Ikehata, M.; Miyakoshi, J.; Sakai, K.

    2004-01-01

    The dose-response relationship of ionizing radiation and its stochastic effects has been thought to be linear without any thresholds. The basic data for this model was obtained from mutational assays in the male germ cells of fruits fly Drosophila melanogaster. However, carcinogenic activity should be examined more appropriately in somatic cells than in germ cells. Here, the dose-response relationship of X- ray irradiation and somatic mutation is examined in Drosophila. A threshold at approximately 1Gy was observed in the DNA repair proficient flies. In the repair deficient siblings, the threshold was smaller and the inclination of the dose-response curve was much steeper. These results suggest that the dose-response relationship between X-ray irradiation and somatic mutation has a threshold, and that the DNA repair function contributes to its formation. (Author) 35 refs

  19. Induction of somatic mutations by low-dose X-rays: the challenge in recognizing radiation-induced events.

    Science.gov (United States)

    Nagashima, Haruki; Shiraishi, Kumiko; Ohkawa, Saori; Sakamoto, Yuki; Komatsu, Kenshi; Matsuura, Shinya; Tachibana, Akira; Tauchi, Hiroshi

    2017-10-19

    It is difficult to distinguish radiation-induced events from spontaneous events during induction of stochastic effects, especially in the case of low-dose or low-dose-rate exposures. By using a hypersensitive system for detecting somatic mutations at the HPRT1 locus, we investigated the frequency and spectrum of mutations induced by low-dose X-rays. The mutant frequencies induced by doses of >0.15 Gy were statistically significant when compared with the spontaneous frequency, and a clear dose dependency was also observed for mutant frequencies at doses of >0.15 Gy. In contrast, mutant frequencies at doses of 0.2 Gy. Our observations suggest that there could be a critical dose for mutation induction at between 0.1 Gy and 0.2 Gy, where mutagenic events are induced by multiple DNA double-strand breaks (DSBs). These observations also suggest that low-dose radiation delivered at doses of <0.1 Gy may not result in DSB-induced mutations but may enhance spontaneous mutagenesis events. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  20. Somatic mutation in larvae of the silkworm, Bombyx mori, induced by heavy ion irradiation to diapause eggs

    Energy Technology Data Exchange (ETDEWEB)

    Kotani, Eiji; Furusawa, Toshiharu [Kyoto Inst. of Tech. (Japan). Faculty of Textile Science; Nagaoka, Shunji [Fujita Health Univ., Toyoake, Aichi (Japan). School of Health Sciences] [and others

    2002-12-01

    In order to investigate whether eggs of the black-striped strain (P{sup S}) of the silkworm, Bombyx mori, represent an appropriate model for estimating the biological effect of cosmic radiation, radiosensitivity of the eggs against X-rays and heavy ion particles was examined as ground-based experiments. The exposure of diapause eggs to X-rays or heavy ion particles resulted in somatic mutations appearing as a white spot on the black integument during larval stage. Irradiation of non-diapause eggs with X-rays demonstrated a significant difference in frequency of the mutation between fractionated and single administration doses, but no difference was observed in diapause eggs. Incidence of the mutation as induced by carbon ion beams for 15-day old eggs was higher for eggs that had been kept at 15 deg C than those kept at 25 deg C. Neon beam irradiation of diapause eggs displayed dose- and linear energy transfer (LET)-dependent effects, causing a maximal rate of the mutation at 150 keV/{mu}m. These results confirm that B. mori eggs represent valid models for estimating the biological effects of cosmic radiation. (author)

  1. NetNorM: Capturing cancer-relevant information in somatic exome mutation data with gene networks for cancer stratification and prognosis.

    Science.gov (United States)

    Le Morvan, Marine; Zinovyev, Andrei; Vert, Jean-Philippe

    2017-06-01

    Genome-wide somatic mutation profiles of tumours can now be assessed efficiently and promise to move precision medicine forward. Statistical analysis of mutation profiles is however challenging due to the low frequency of most mutations, the varying mutation rates across tumours, and the presence of a majority of passenger events that hide the contribution of driver events. Here we propose a method, NetNorM, to represent whole-exome somatic mutation data in a form that enhances cancer-relevant information using a gene network as background knowledge. We evaluate its relevance for two tasks: survival prediction and unsupervised patient stratification. Using data from 8 cancer types from The Cancer Genome Atlas (TCGA), we show that it improves over the raw binary mutation data and network diffusion for these two tasks. In doing so, we also provide a thorough assessment of somatic mutations prognostic power which has been overlooked by previous studies because of the sparse and binary nature of mutations.

  2. Somatic mutations in PIK3CA and activation of AKT in intraductal tubulopapillary neoplasms of the pancreas.

    Science.gov (United States)

    Yamaguchi, Hiroshi; Kuboki, Yuko; Hatori, Takashi; Yamamoto, Masakazu; Shiratori, Keiko; Kawamura, Shunji; Kobayashi, Makio; Shimizu, Michio; Ban, Shinichi; Koyama, Isamu; Higashi, Morihiro; Shin, Nobuhiro; Ishida, Kazuyuki; Morikawa, Takanori; Motoi, Fuyuhiko; Unno, Michiaki; Kanno, Atsushi; Satoh, Kennichi; Shimosegawa, Tooru; Orikasa, Hideki; Watanabe, Tomoo; Nishimura, Kazuhiko; Harada, Youji; Furukawa, Toru

    2011-12-01

    Intraductal tubulopapillary neoplasm (ITPN) is a recently recognized rare variant of intraductal neoplasms of the pancreas. Molecular aberrations underlying the neoplasm remain unknown. We investigated somatic mutations in PIK3CA, PTEN, AKT1, KRAS, and BRAF. We also investigated aberrant expressions of phosphorylated AKT, phosphatase and tensin homolog (PTEN), tumor protein 53 (TP53), SMAD4, and CTNNB1 in 11 cases of ITPNs and compared these data with those of 50 cases of intraductal papillary mucinous neoplasm (IPMN), another distinct variant of pancreatic intraductal neoplasms. Mutations in PIK3CA were found in 3 of 11 ITPNs but not in IPMNs (P = 0.005; Fisher exact test). In contrast, mutations in KRAS were found in none of the ITPNs but were found in 26 of the 50 IPMNs (P = 0.001; Fisher exact test). PIK3CA mutations were associated with strong expression of phosphorylated AKT (P AKT was apparent in most ITPNs but only in a few IPMNs (P SMAD4, and CTNNB1 were not statistically different between these neoplasms. Mutations in PIK3CA and the expression of phosphorylated AKT were not associated with age, sex, tissue invasion, and patients' prognosis in ITPNs. These results indicate that activation of the phosphatidylinositol 3-kinase pathway may play a crucial role in ITPNs but not in IPMNs. In contrast, the mutation in KRAS seems to play a major role in IPMNs but not in ITPNs. The activated phosphatidylinositol 3-kinase pathway may be a potential target for molecular diagnosis and therapy of ITPNs.

  3. MutSpec: a Galaxy toolbox for streamlined analyses of somatic mutation spectra in human and mouse cancer genomes.

    Science.gov (United States)

    Ardin, Maude; Cahais, Vincent; Castells, Xavier; Bouaoun, Liacine; Byrnes, Graham; Herceg, Zdenko; Zavadil, Jiri; Olivier, Magali

    2016-04-18

    The nature of somatic mutations observed in human tumors at single gene or genome-wide levels can reveal information on past carcinogenic exposures and mutational processes contributing to tumor development. While large amounts of sequencing data are being generated, the associated analysis and interpretation of mutation patterns that may reveal clues about the natural history of cancer present complex and challenging tasks that require advanced bioinformatics skills. To make such analyses accessible to a wider community of researchers with no programming expertise, we have developed within the web-based user-friendly platform Galaxy a first-of-its-kind package called MutSpec. MutSpec includes a set of tools that perform variant annotation and use advanced statistics for the identification of mutation signatures present in cancer genomes and for comparing the obtained signatures with those published in the COSMIC database and other sources. MutSpec offers an accessible framework for building reproducible analysis pipelines, integrating existing methods and scripts developed in-house with publicly available R packages. MutSpec may be used to analyse data from whole-exome, whole-genome or targeted sequencing experiments performed on human or mouse genomes. Results are provided in various formats including rich graphical outputs. An example is presented to illustrate the package functionalities, the straightforward workflow analysis and the richness of the statistics and publication-grade graphics produced by the tool. MutSpec offers an easy-to-use graphical interface embedded in the popular Galaxy platform that can be used by researchers with limited programming or bioinformatics expertise to analyse mutation signatures present in cancer genomes. MutSpec can thus effectively assist in the discovery of complex mutational processes resulting from exogenous and endogenous carcinogenic insults.

  4. Improvement of mutation rate and reduction of somatic effects by double treatment of chemical mutagens in barley

    International Nuclear Information System (INIS)

    Koo, B.C.; Maluszynski, M.

    1996-01-01

    Mutation techniques inducing more useful mutations and reducing somatic effects need to be improved for crop breeding. Seeds of barley varieties; Dema, Grosso were treated with two types of mutagens; 1) chemical treatment: single treatment or double treatment of two mutagens (N-nitroso-N-methylurea ; MNH, Sodium Azide; NaN 3 ) 2) gamma ray irradiation treatment. After treatment, half of seeds were used for germination test and half of seeds were sown to the field. With the higher dose of mutagen both chemical and gamma ray were plants treated, the higher rate of growth reduction rate was in M 1 seedling. In chemical treatment, germination rate of seeds, growth rate of coleoptile and root in double treatment of chemical mutagens were better than single treatments, especially in same dose. Growth inhibition rate of plant in double treatment of 1.0 mM MNH (0.5 mM MNH + 0.5 mM MNH), for example, were less than one of plants of single treatment of 1.0 mM MNH in pot and petri dish test. Growth reduction rate of culm and fertility rate in M 1 plants double treated in same dose of single treatment were also less than single one. With the higher dose of mutagen both chemical and gamma ray were plants treated, the higher frequency of chlorophyll mutants was in M 2 seedling. The rate of chlorophyll mutants in double treatment of chemical mutagens were higher than single treatment. Double treatment methods can be a improved method for induction of new good mutants, which were induced more useful mutations and reduced harmful somatic effects

  5. Somatic mutation in peripheral blood lymphocytes among Metro Manila residents: indicator of exposure to environmental pollution

    International Nuclear Information System (INIS)

    Yulo-Nazarea, M.T.; Cobar, M.L.C.; Endriga, M.A.; Sta Maria, E.J.; Nato, A.Q.; Eduardo, J.; Dy, R.

    1994-01-01

    Metro Manila is ranked as one of the world's most polluted cities where air quality levels are 2-3 times higher than the levels set by WHO. Development of diseases could be alleviated if early warning signs as occurrence of gene mutations are detected early enough. The adapted hypoxanthine guanine phosphoribosyl transferase (HGPRT) mutation assay measures the degree of mutation on the HGPRT gene and allows rapid evaluation of the occurrence of mutation in an individual exposed to radiation or mutagens within six months after exposure. The objective of the project is to (1) assay exposure of Metro Manila residents exposed to environmental pollution, (2) determine population groups significantly affected by pollutants and (3) construct an environmental baseline HGPRT mutation data bank specific to area in Metro Manila. A composite table of personal information of donors against mutation index in two barangays in Venezuela is presented. About 30% of the total samples are shown to have mutation index greater than 0.5. So far, the data show a slightly higher mutation rate among donors who are smokers with more than 5 hours outdoor exposure to pollutants per day than the corresponding class of non-smokers. (author). 5 refs.; 5 tabs

  6. Integrative genome analyses identify key somatic driver mutations of small-cell lung cancer

    NARCIS (Netherlands)

    Peifer, Martin; Fernandez-Cuesta, Lynnette; Sos, Martin L.; George, Julie; Seidel, Danila; Kasper, Lawryn H.; Plenker, Dennis; Leenders, Frauke; Sun, Ruping; Zander, Thomas; Menon, Roopika; Koker, Mirjam; Dahmen, Ilona; Mueller, Christian; Di Cerbo, Vincenzo; Schildhaus, Hans-Ulrich; Altmueller, Janine; Baessmann, Ingelore; Becker, Christian; de Wilde, Bram; Vandesompele, Jo; Boehm, Diana; Ansen, Sascha; Gabler, Franziska; Wilkening, Ines; Heynck, Stefanie; Heuckmann, Johannes M.; Lu, Xin; Carter, Scott L.; Cibulskis, Kristian; Banerji, Shantanu; Getz, Gad; Park, Kwon-Sik; Rauh, Daniel; Gruetter, Christian; Fischer, Matthias; Pasqualucci, Laura; Wright, Gavin; Wainer, Zoe; Russell, Prudence; Petersen, Iver; Chen, Yuan; Stoelben, Erich; Ludwig, Corinna; Schnabel, Philipp; Hoffmann, Hans; Muley, Thomas; Brockmann, Michael; Engel-Riedel, Walburga; Muscarella, Lucia A.; Fazio, Vito M.; Groen, Harry; Timens, Wim; Sietsma, Hannie; Thunnissen, Erik; Smit, Egbert; Heideman, Danielle A. M.; Snijders, Peter J. F.; Cappuzzo, Federico; Ligorio, Claudia; Damiani, Stefania; Field, John; Solberg, Steinar; Brustugun, Odd Terje; Lund-Iversen, Marius; Saenger, Joerg; Clement, Joachim H.; Soltermann, Alex; Moch, Holger; Weder, Walter; Solomon, Benjamin; Soria, Jean-Charles; Validire, Pierre; Besse, Benjamin; Brambilla, Elisabeth; Brambilla, Christian; Lantuejoul, Sylvie; Lorimier, Philippe; Schneider, Peter M.; Hallek, Michael; Pao, William; Meyerson, Matthew; Sage, Julien; Shendure, Jay; Schneider, Robert; Buettner, Reinhard; Wolf, Juergen; Nuernberg, Peter; Perner, Sven; Heukamp, Lukas C.; Brindle, Paul K.; Haas, Stefan; Thomas, Roman K.

    2012-01-01

    Small-cell lung cancer (SCLC) is an aggressive lung tumor subtype with poor prognosis(1-3). We sequenced 29 SCLC exomes, 2 genomes and 15 transcriptomes and found an extremely high mutation rate of 7.4 +/- 1 protein-changing mutations per million base pairs. Therefore, we conducted integrated

  7. Somatic frameshift mutations in the Bloom syndrome BLM gene are frequent in sporadic gastric carcinomas with microsatellite mutator phenotype

    Directory of Open Access Journals (Sweden)

    Matei Irina

    2001-08-01

    Full Text Available Abstract Background Genomic instability has been reported at microsatellite tracts in few coding sequences. We have shown that the Bloom syndrome BLM gene may be a target of microsatelliteinstability (MSI in a short poly-adenine repeat located in its coding region. To further characterize the involvement of BLM in tumorigenesis, we have investigated mutations in nine genes containing coding microsatellites in microsatellite mutator phenotype (MMP positive and negative gastric carcinomas (GCs. Methods We analyzed 50 gastric carcinomas (GCs for mutations in the BLM poly(A tract aswell as in the coding microsatellites of the TGFβ1-RII, IGFIIR, hMSH3, hMSH6, BAX, WRN, RECQL and CBL genes. Results BLM mutations were found in 27% of MMP+ GCs (4/15 cases but not in any of the MMP negative GCs (0/35 cases. The frequency of mutations in the other eight coding regions microsatellite was the following: TGFβ1-RII (60 %, BAX (27%, hMSH6 (20%,hMSH3 (13%, CBL (13%, IGFIIR (7%, RECQL (0% and WRN (0%. Mutations in BLM appear to be more frequently associated with frameshifts in BAX and in hMSH6and/or hMSH3. Tumors with BLM alterations present a higher frequency of unstable mono- and trinucleotide repeats located in coding regions as compared with mutator phenotype tumors without BLM frameshifts. Conclusions BLM frameshifts are frequent alterations in GCs specifically associated with MMP+tumors. We suggest that BLM loss of function by MSI may increase the genetic instability of a pre-existent unstable genotype in gastric tumors.

  8. Somatic frameshift mutations in the Bloom syndrome BLM gene are frequent in sporadic gastric carcinomas with microsatellite mutator phenotype

    Science.gov (United States)

    Calin, George; Ranzani, Guglielmina N; Amadori, Dino; Herlea, Vlad; Matei, Irina; Barbanti-Brodano, Giuseppe; Negrini, Massimo

    2001-01-01

    Background Genomic instability has been reported at microsatellite tracts in few coding sequences. We have shown that the Bloom syndrome BLM gene may be a target of microsatelliteinstability (MSI) in a short poly-adenine repeat located in its coding region. To further characterize the involvement of BLM in tumorigenesis, we have investigated mutations in nine genes containing coding microsatellites in microsatellite mutator phenotype (MMP) positive and negative gastric carcinomas (GCs). Methods We analyzed 50 gastric carcinomas (GCs) for mutations in the BLM poly(A) tract aswell as in the coding microsatellites of the TGFβ1-RII, IGFIIR, hMSH3, hMSH6, BAX, WRN, RECQL and CBL genes. Results BLM mutations were found in 27% of MMP+ GCs (4/15 cases) but not in any of the MMP negative GCs (0/35 cases). The frequency of mutations in the other eight coding regions microsatellite was the following: TGFβ1-RII (60 %), BAX (27%), hMSH6 (20%),hMSH3 (13%), CBL (13%), IGFIIR (7%), RECQL (0%) and WRN (0%). Mutations in BLM appear to be more frequently associated with frameshifts in BAX and in hMSH6and/or hMSH3. Tumors with BLM alterations present a higher frequency of unstable mono- and trinucleotide repeats located in coding regions as compared with mutator phenotype tumors without BLM frameshifts. Conclusions BLM frameshifts are frequent alterations in GCs specifically associated with MMP+tumors. We suggest that BLM loss of function by MSI may increase the genetic instability of a pre-existent unstable genotype in gastric tumors. PMID:11532193

  9. Somatic mutation of EZH2 (Y641) in follicular and diffuse large B-cell lymphomas of germinal center origin | Office of Cancer Genomics

    Science.gov (United States)

    Morin et al. describe recurrent somatic mutations in EZH2, a polycomb group oncogene. The mutation, found in the SET domain of this gene encoding a histone methyltransferase, is found only in a subset of lymphoma samples. Specifically, EZH2 mutations are found in about 12% of follicular lymphomas (FL) and almost 23% of diffuse large B-cell lymphomas (DLBCL) of germinal center origin. This paper goes on to demonstrate that altered EZH2 proteins, corresponding to the most frequent mutations found in human lymphomas, have reduced activity using in vitro histone methylation assays.

  10. Biodosimetry of Chernobyl cleanup workers from Estonia and Latvia using the glycophorin A in vivo somatic cell mutation assay

    International Nuclear Information System (INIS)

    Bigbee, W.L.; Jensen, R.H.; Veidebaum, T.

    1997-01-01

    The reactor accident at Chernobyl in 1986 necessitated a massive environmental cleanup that involved over 600,000 workers from all 15 Republics of the former Soviet Union. To determine whether the whole-body radiation received by workers in the course of these decontamination activities resulted in a detectable biological response, over 1,500 blood samples were obtained from cleanup workers sent from two Baltic countries, Estonia and Latvia. Here we report the results of studies of biodosimetry using the glycophorin A (GPA) locus in vivo somatic cell mutation assay applied to 734 blood samples from these workers, to 51 control samples from unexposed Baltic populations and to 94 samples from historical U.S. controls. The data reveal inconsistent evidence that the protracted radiation exposures received by these workers resulted in a significant dose-associated increase in GPA locus mutations compared with the controls. Taken together, these data suggest that the average radiation exposure to these workers does not greatly exceed 10 cGy, the minimum levels at which radiation effects might be detectable by the assay. Although the protracted nature of the exposure may have reduced the efficiency of induction of GPA locus mutations, it is likely that the estimated physical doses for these cleanup worker populations (median reported dose 9.5 cGy) were too low to result in radiation damage to erythroid stem cells that can be detected reliably by this method. 25 refs., 2 figs., 3 tabs

  11. Estimating Exceptionally Rare Germline and Somatic Mutation Frequencies via Next Generation Sequencing.

    Directory of Open Access Journals (Sweden)

    Jordan Eboreime

    Full Text Available We used targeted next generation deep-sequencing (Safe Sequencing System to measure ultra-rare de novo mutation frequencies in the human male germline by attaching a unique identifier code to each target DNA molecule. Segments from three different human genes (FGFR3, MECP2 and PTPN11 were studied. Regardless of the gene segment, the particular testis donor or the 73 different testis pieces used, the frequencies for any one of the six different mutation types were consistent. Averaging over the C>T/G>A and G>T/C>A mutation types the background mutation frequency was 2.6x10-5 per base pair, while for the four other mutation types the average background frequency was lower at 1.5x10-6 per base pair. These rates far exceed the well documented human genome average frequency per base pair (~10-8 suggesting a non-biological explanation for our data. By computational modeling and a new experimental procedure to distinguish between pre-mutagenic lesion base mismatches and a fully mutated base pair in the original DNA molecule, we argue that most of the base-dependent variation in background frequency is due to a mixture of deamination and oxidation during the first two PCR cycles. Finally, we looked at a previously studied disease mutation in the PTPN11 gene and could easily distinguish true mutations from the SSS background. We also discuss the limits and possibilities of this and other methods to measure exceptionally rare mutation frequencies, and we present calculations for other scientists seeking to design their own such experiments.

  12. Is Increased Low-dose somatic Radiosensitivity Associated with Increased Transgenerational Germline Mutation

    International Nuclear Information System (INIS)

    Brenner, David J.

    2008-01-01

    Using single-molecule polymerase chain reaction, the frequency of spontaneous and radiation-induced mutation at an expanded simple tandem repeat (ESTR) locus was studied in DNA samples extracted from sperm and bone marrow of Atm knockout (Atm+/-) heterozygous male mice. The frequency of spontaneous mutation in sperm and bone marrow in Atm+/- males did not significantly differ from that in wild-type BALB/c mice. Acute gamma-ray exposure did not affect ESTR mutation frequency in bone marrow and resulted in similar increases in sperm samples taken from Atm+/- and BALB/c males. Taken together, these results suggest that the Atm haploinsufficiency analyzed in our study does not affect spontaneous and radiation-induced ESTR mutation frequency in mice

  13. Germline PMS2 and somatic POLE exonuclease mutations cause hypermutability of the leading DNA strand in biallelic mismatch repair deficiency syndrome brain tumours.

    Science.gov (United States)

    Andrianova, Maria A; Chetan, Ghati Kasturirangan; Sibin, Madathan Kandi; Mckee, Thomas; Merkler, Doron; Narasinga, Rao Kvl; Ribaux, Pascale; Blouin, Jean-Louis; Makrythanasis, Periklis; Seplyarskiy, Vladimir B; Antonarakis, Stylianos E; Nikolaev, Sergey I

    2017-11-01

    Biallelic mismatch repair deficiency (bMMRD) in tumours is frequently associated with somatic mutations in the exonuclease domains of DNA polymerases POLE or POLD1, and results in a characteristic mutational profile. In this article, we describe the genetic basis of ultramutated high-grade brain tumours in the context of bMMRD. We performed exome sequencing of two second-cousin patients from a large consanguineous family of Indian origin with early onset of high-grade glioblastoma and astrocytoma. We identified a germline homozygous nonsense variant, p.R802*, in the PMS2 gene. Additionally, by genome sequencing of these tumours, we found extremely high somatic mutation rates (237/Mb and 123/Mb), as well as somatic mutations in the proofreading domain of POLE polymerase (p.P436H and p.L424V), which replicates the leading DNA strand. Most interestingly, we found, in both cancers, that the vast majority of mutations were consistent with the signature of POLE exo - , i.e. an abundance of C>A and C>T mutations, particularly in special contexts, on the leading strand. We showed that the fraction of mutations under positive selection among mutations in tumour suppressor genes is more than two-fold lower in ultramutated tumours than in other glioblastomas. Genetic analyses enabled the diagnosis of the two consanguineous childhood brain tumours as being due to a combination of PMS2 germline and POLE somatic variants, and confirmed them as bMMRD/POLE exo - disorders. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  14. Targeted heavy-ion microbeam irradiation of the embryo but not yolk in the diapause-terminated egg of the silkworm, bombyx mori, induces the somatic mutation

    International Nuclear Information System (INIS)

    Furusawa, Toshiharu; Fukamoto, Kana; Sakashita, Tetsuya; Funayama, Tomoo; Kobayashi, Yasuhiko; Kakizaki, Takehiko; Wada, Seiichi; Hamada, Nobuyuki; Suzuki, Hiromi; Ishioka, Noriaki; Nagaoka, Shunji

    2009-01-01

    Using heavy-ion microbeam, we report target irradiation of selected compartments within the diapause-terminated egg and its mutational consequences in the silkworm, Bombyx mori. On one hand, carbon-ion exposure of embryo to 0.5-6 Gy increased the somatic mutation frequency, suggesting targeted radiation effects. On the other, such increases were not observed when yolk was targeted, suggesting a lack of nontargeted bystander effect. (author)

  15. Analysis of relation between the mutation frequencies and somatic recombination induced by neutrons and the age of D. Melanogaster larvae

    International Nuclear Information System (INIS)

    Guzman R, J.; Zambrano A, F.; Paredes G, L.; Delfin L, A.; Quiroz R, C.

    1998-01-01

    Neutrons are subatomic particles with neutral electric charge, equal zero, which are emitted during the fissile material fission in nuclear reactors. It is known a little about biological effects induced by neutrons. There is a world interest in the use of reactors and accelerators for patients radiotherapy using neutrons with the purpose to destroy malignant cells of deep tumours where traditional methods have not given satisfactory results. There for it is required to do wide studies of biological effects of neutrons as well as their dosimetry. It was used the Smart test (Somatic Mutation and Recombination Test) of D. Melanogaster for quantifying the mutation induction and somatic recombination induced by neutrons of the National Institute of Nuclear Research reactor, at power of 300 and 1000 k W, with equivalent doses calculated 95.14 and 190.2 Sv for 300 k W and of 25.64 and 51.29 Sv for 1000 k W, using larvae with 72 or 96 hours aged. It was observed a linear relation between equivalent dose and genetic effects frequency, these last were greater when the reactor power was 1000 k W than those 300 k W. It was observed too that the damage was greater in 96 hours larvae than those 72 hours. The stain size presented an inverse relation with respect to larvae age. It is concluded that the Smart system is sensitive to neutrons effect and it responds of a directly proportional form to radiation dose, as well as to dose rate. It is noted more the effect when are used larvas in pre pupa stage where the irradiation target (imagal cells) is greater. The Smart is sensitive to damage induced by neutrons , thus can be used to studying its direct biological effects or by the use of chemical modulators. (Author)

  16. Somatic mutations in ATP1A1 and ATP2B3 lead to aldosterone-producing adenomas and secondary hypertension

    DEFF Research Database (Denmark)

    Beuschlein, Felix; Boulkroun, Sheerazed; Osswald, Andrea

    2013-01-01

    Primary aldosteronism is the most prevalent form of secondary hypertension. To explore molecular mechanisms of autonomous aldosterone secretion, we performed exome sequencing of aldosterone-producing adenomas (APAs). We identified somatic hotspot mutations in the ATP1A1 (encoding an Na+/K+ ATPase α...

  17. Somatic mosaicism of a point mutation in the dystrophin gene in a patient presenting with an asymmetrical muscle weakness and contractures

    NARCIS (Netherlands)

    Helderman-van den Enden, A. T. J. M.; Ginjaar, H. B.; Kneppers, A. L. J.; Bakker, E.; Breuning, M. H.; de Visser, M.

    2003-01-01

    We describe a patient with somatic mosaicism of a point mutation in the dystrophin gene causing benign muscular dystrophy with an unusual asymmetrical distribution of muscle weakness and contractures. To our knowledge this is the first patient with asymmetrical weakness and contractures in an

  18. Inspecting Targeted Deep Sequencing of Whole Genome Amplified DNA Versus Fresh DNA for Somatic Mutation Detection: A Genetic Study in Myelodysplastic Syndrome Patients.

    Science.gov (United States)

    Palomo, Laura; Fuster-Tormo, Francisco; Alvira, Daniel; Ademà, Vera; Armengol, María Pilar; Gómez-Marzo, Paula; de Haro, Nuri; Mallo, Mar; Xicoy, Blanca; Zamora, Lurdes; Solé, Francesc

    2017-08-01

    Whole genome amplification (WGA) has become an invaluable method for preserving limited samples of precious stock material and has been used during the past years as an alternative tool to increase the amount of DNA before library preparation for next-generation sequencing. Myelodysplastic syndromes (MDS) are a group of clonal hematopoietic stem cell disorders characterized by presenting somatic mutations in several myeloid-related genes. In this work, targeted deep sequencing has been performed on four paired fresh DNA and WGA DNA samples from bone marrow of MDS patients, to assess the feasibility of using WGA DNA for detecting somatic mutations. The results of this study highlighted that, in general, the sequencing and alignment statistics of fresh DNA and WGA DNA samples were similar. However, after variant calling and when considering variants detected at all frequencies, there was a high level of discordance between fresh DNA and WGA DNA (overall, a higher number of variants was detected in WGA DNA). After proper filtering, a total of three somatic mutations were detected in the cohort. All somatic mutations detected in fresh DNA were also identified in WGA DNA and validated by whole exome sequencing.

  19. Trichloroethylene exposure and somatic mutations of the VHL gene in patients with Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Fevotte Joelle

    2007-11-01

    Full Text Available Abstract Background We investigated the association between exposure to trichloroethylene (TCE and mutations in the von Hippel-Lindau (VHL gene and the subsequent risk for renal cell carcinoma (RCC. Methods Cases were recruited from a case-control study previously carried out in France that suggested an association between exposures to high levels of TCE and increased risk of RCC. From 87 cases of RCC recruited for the epidemiological study, 69 were included in the present study. All samples were evaluated by a pathologist in order to identify the histological subtype and then be able to focus on clear cell RCC. The majority of the tumour samples were fixed either in formalin or Bouin's solutions. The majority of the tumours were of the clear cell RCC subtype (48 including 2 cystic RCC. Mutation screening of the 3 VHL coding exons was carried out. A descriptive analysis was performed to compare exposed and non exposed cases of clear cell RCC in terms of prevalence of mutations in both groups. Results In the 48 cases of RCC, four VHL mutations were detected: within exon 1 (c.332G>A, p.Ser111Asn, at the exon 2 splice site (c.463+1G>C and c.463+2T>C and within exon 3 (c.506T>C, p.Leu169Pro. No difference was observed regarding the frequency of mutations in exposed versus unexposed groups: among the clear cell RCC, 25 had been exposed to TCE and 23 had no history of occupational exposure to TCE. Two patients with a mutation were identified in each group. Conclusion This study does not confirm the association between the number and type of VHL gene mutations and exposure to TCE previously described.

  20. Pre-thymic somatic mutation leads to high mutant frequency at hypoxanthine-guanine phosphoribosyltransferase gene

    Energy Technology Data Exchange (ETDEWEB)

    Jett, J. [Lawrence Livermore National Lab., CA (United States)

    1994-12-01

    While characterizing the background mutation spectrum of the Hypoxathine-guanine phosphoribosyltransferase (HPRT) gene in a healthy population, an outlier with a high mutant frequency of thioguanine resistant lymphocytes was found. When studied at the age of 46, this individual had been smoking 60 cigarettes per day for 38 years. His mutant frequency was calculated at 3.6 and 4.2x10{sup {minus}4} for two sampling periods eight months apart. Sequencing analysis of the HPRT gene in his mutant thioguanine resistant T lymphocytes was done to find whether the cells had a high rate of mutation, or if the mutation was due to a single occurrence of mutation and, if so, when in the T lymphocyte development the mutation occurred. By T-cell receptor analysis it has been found that out of 35 thioguanine resistant clones there was no dominant gamma T cell receptor gene rearrangement. During my appointment in the Science & Engineering Research Semester, I found that 34 of those clones have the same base substitution of G{yields}T at cDNA position 197. Due to the consistent mutant frequency from both sampling periods and the varying T cell receptors, the high mutant frequency cannot be due to recent proliferation of a mature mutant T lymphocyte. From the TCR and DNA sequence analysis we conclude that the G{yields}T mutation must have occurred in a T lymphocyte precursor before thymic differentiation so that the thioguanine resistant clones share the same base substitution but not the same gamma T cell receptor gene.

  1. Induction of mutation in Micrococcus pyogenes by chemical inactivation of sulfhydryl groups

    Energy Technology Data Exchange (ETDEWEB)

    Clark, J B; Wyss, O; Stone, W S

    1950-08-26

    The purpose of this work was to determine whether this naphthaquinone could induce antibiotic-resistant mutants in Micrococcus pyogenes var. aureus, and to determine if such mutagenicity was due to -SH inactivation.

  2. IgV(H) and bcl6 somatic mutation analysis reveals the heterogeneity of cutaneous B-cell lymphoma, and indicates the presence of undisclosed local antigens.

    Science.gov (United States)

    Franco, Renato; Camacho, Francisca I; Fernández-Vázquez, Amalia; Algara, Patrocinio; Rodríguez-Peralto, José L; De Rosa, Gaetano; Piris, Miguel A

    2004-06-01

    Our understanding of the ontology of B-cell lymphomas (BCL) has been improved by the study of mutational status of IgV(H) and bcl6 genes, but only a few cases of cutaneous BCL have been examined for this status. We analyzed IgV(H) and bcl6 somatic mutations in 10 cutaneous BCL, classified as follicular (three primary and one secondary), primary marginal zone (two cases), and diffuse large BCL (three primary and one secondary). We observed a lower rate (IgV(H) mutation in all marginal zone lymphomas, and a preferential usage of V(H)2-70 (one primary follicular and two primary diffuse large BCL). Fewer than expected replacement mutations in framework regions (FR) were observed in three primary follicular lymphomas (FLs) and in all diffuse large BCL, indicating a negative antigen selection pressure. Ongoing mutations were observed in eight of 10 cases. Only two primary FLs and two diffuse large BCL showed bcl6 somatic mutation. These data support the heterogeneous nature of the different cutaneous BCL, and specifically the distinction between cutaneous follicular and marginal zone lymphomas. The biased usage of V(H)2-70, the low rate of replacement mutation in the FR, and the presence of ongoing mutation imply that local antigens could modulate the growth of primary cutaneous BCL.

  3. A pan-cancer analysis of transcriptome changes associated with somatic mutations in U2AF1 reveals commonly altered splicing events.

    Directory of Open Access Journals (Sweden)

    Angela N Brooks

    Full Text Available Although recurrent somatic mutations in the splicing factor U2AF1 (also known as U2AF35 have been identified in multiple cancer types, the effects of these mutations on the cancer transcriptome have yet to be fully elucidated. Here, we identified splicing alterations associated with U2AF1 mutations across distinct cancers using DNA and RNA sequencing data from The Cancer Genome Atlas (TCGA. Using RNA-Seq data from 182 lung adenocarcinomas and 167 acute myeloid leukemias (AML, in which U2AF1 is somatically mutated in 3-4% of cases, we identified 131 and 369 splicing alterations, respectively, that were significantly associated with U2AF1 mutation. Of these, 30 splicing alterations were statistically significant in both lung adenocarcinoma and AML, including three genes in the Cancer Gene Census, CTNNB1, CHCHD7, and PICALM. Cell line experiments expressing U2AF1 S34F in HeLa cells and in 293T cells provide further support that these altered splicing events are caused by U2AF1 mutation. Consistent with the function of U2AF1 in 3' splice site recognition, we found that S34F/Y mutations cause preferences for CAG over UAG 3' splice site sequences. This report demonstrates consistent effects of U2AF1 mutation on splicing in distinct cancer cell types.

  4. Somatic mtDNA mutation spectra in the aging human putamen.

    Directory of Open Access Journals (Sweden)

    Siôn L Williams

    Full Text Available The accumulation of heteroplasmic mitochondrial DNA (mtDNA deletions and single nucleotide variants (SNVs is a well-accepted facet of the biology of aging, yet comprehensive mutation spectra have not been described. To address this, we have used next generation sequencing of mtDNA-enriched libraries (Mito-Seq to investigate mtDNA mutation spectra of putamen from young and aged donors. Frequencies of the "common" deletion and other "major arc" deletions were significantly increased in the aged cohort with the fold increase in the frequency of the common deletion exceeding that of major arc deletions. SNVs also increased with age with the highest rate of accumulation in the non-coding control region which contains elements necessary for translation and replication. Examination of predicted amino acid changes revealed a skew towards pathogenic SNVs in the coding region driven by mutation bias. Levels of the pathogenic m.3243A>G tRNA mutation were also found to increase with age. Novel multimeric tandem duplications that resemble murine control region multimers and yeast ρ(- mtDNAs, were identified in both young and aged specimens. Clonal ∼50 bp deletions in the control region were found at high frequencies in aged specimens. Our results reveal the complex manner in which the mitochondrial genome alters with age and provides a foundation for studies of other tissues and disease states.

  5. JAK2V617F Somatic Mutation In The General Population

    DEFF Research Database (Denmark)

    Nielsen, Camilla; Bojesen, Stig E; Nordestgaard, Børge G

    2014-01-01

    of myeloproliferative neoplasm from no disease (n=8 at re-examination) through essential thrombocythemia (n=20) and polycythemia vera (n=13) to primary myelofibrosis (n=7). Among those diagnosed with a myeloproliferative neoplasm only at re-examination in 2012, in the preceding years JAK2V617F mutation burden increased...

  6. Gain-of-function somatic mutations contribute to inflammation and blood vessel damage that lead to Alzheimer dementia: a hypothesis.

    Science.gov (United States)

    Marchesi, Vincent T

    2016-02-01

    Amyloid deposits are a characteristic feature of advanced Alzheimer dementia (AD), but whether they initiate the disease or are a consequence of it remains an unsettled question. To explore an alternative pathogenic mechanism, I propose that the triggering events that begin the pathogenic cascade are not amyloid deposits but damaged blood vessels caused by inflammatory reactions that lead to ischemia, amyloid accumulation, axonal degeneration, synaptic loss, and eventually irreversible neuronal cell death. Inflammation and blood vessel damage are well recognized complications of AD, but what causes them and why the cerebral microvasculature is affected have never been adequately addressed. Because heritable autosomal dominant mutations of NLRP3, APP, TREX1, NOTCH3, and Col4A1 are known to provoke inflammatory reactions and damage the brain in a wide variety of diseases, I propose that one or more low abundant, gain-of-function somatic mutations of the same 5 gene families damage the microvasculature of the brain that leads to dementia. This implies that the pathogenic triggers that lead to AD are derived not from external invaders or amyloid but from oxidative damage of our own genes. © FASEB.

  7. Germ-line mutations of the p53 tumor suppressor gene in patients with high risk for cancer inactivate the p53 protein.

    OpenAIRE

    Frebourg, T; Kassel, J; Lam, K T; Gryka, M A; Barbier, N; Andersen, T I; Børresen, A L; Friend, S H

    1992-01-01

    Germ-line mutations in the p53 tumor suppressor gene have been observed in patients with Li-Fraumeni syndrome, brain tumors, second malignancies, and breast cancers. It is unclear whether all of these mutations have inactivated p53 and thereby provide an increased risk for cancer. Therefore, it is necessary to establish the biological significance of these germ-line mutations by the functional and structural analysis of the resulting mutant p53 proteins. We analyzed the ability of seven germ-...

  8. Combination of RNA- and exome-sequencing efficiently eliminates false-positive somatic point mutations and indels – exemplified by cases of CN-AML

    DEFF Research Database (Denmark)

    Herborg, Laura Laine; Hansen, Marcus Celik; Roug, Anne Stidsholt

    Thorough annotation as a means of detecting highly relevant mutations, and aberrated genes, is becoming more feasible as the evidence of biological pathways underlying malignant transformation compiles. However, there is a continuous risk of misinterpretating both true and false positive observat......Thorough annotation as a means of detecting highly relevant mutations, and aberrated genes, is becoming more feasible as the evidence of biological pathways underlying malignant transformation compiles. However, there is a continuous risk of misinterpretating both true and false positive...... in the workflow, not only provides information on malignant expression profiles excluded here, but importantly help to capture the, often very few somatic mutations of myeloid leukaemia....

  9. Novel somatic mutations in the catalytic subunit of the protein kinase A as a cause of adrenal Cushing's syndrome: a European multicentric study.

    Science.gov (United States)

    Di Dalmazi, Guido; Kisker, Caroline; Calebiro, Davide; Mannelli, Massimo; Canu, Letizia; Arnaldi, Giorgio; Quinkler, Marcus; Rayes, Nada; Tabarin, Antoine; Laure Jullié, Marie; Mantero, Franco; Rubin, Beatrice; Waldmann, Jens; Bartsch, Detlef K; Pasquali, Renato; Lohse, Martin; Allolio, Bruno; Fassnacht, Martin; Beuschlein, Felix; Reincke, Martin

    2014-10-01

    Somatic mutations in PRKACA gene, encoding the catalytic subunit of protein kinase A (PKA), have been recently found in a high proportion of sporadic adenomas associated with Cushing's syndrome. The aim was to analyze the PRKACA mutation in a large cohort of patients with adrenocortical masses. Samples from nine European centers were included (Germany, n = 4; Italy, n = 4; France, n = 1). Samples were drawn from 149 patients with nonsecreting adenomas (n = 32 + 2 peritumoral), subclinical hypercortisolism (n = 36), Cushing's syndrome (n = 64 + 2 peritumoral), androgen-producing tumors (n = 4), adrenocortical carcinomas (n = 5 + 2 peritumoral), and primary bilateral macronodular adrenal hyperplasias (n = 8). Blood samples were available from patients with nonsecreting adenomas (n = 15), subclinical hypercortisolism (n = 10), and Cushing's syndrome (n = 35). Clinical and hormonal data were collected. DNA amplification by PCR of exons 6 and 7 of the PRKACA gene and direct sequencing were performed. PRKACA heterozygous mutations were found in 22/64 samples of Cushing's syndrome patients (34%). No mutations were found in peritumoral tissue and blood samples or in other tumors examined. The c.617A>C (p.Leu206Arg) occurred in 18/22 patients. Furthermore, two novel mutations were identified: c.600_601insGTG/p.Cys200_Gly201insVal in three patients and c.639C>G+c.638_640insATTATCCTGAGG/p.Ser213Arg+p.Leu212_Lys214insIle-Ile-Leu-Arg) in one. All the mutations involved a region implicated in interaction between PKA regulatory and catalytic subunits. Patients with somatic PRKACA mutations showed higher levels of cortisol after dexamethasone test and a smaller adenoma size, compared with nonmutated subjects. These data confirm and extend previous observations that somatic PRKACA mutations are specific for adrenocortical adenomas causing Cushing's syndrome.

  10. Somatic PTPN11 Mutation in a Child With Neuroblastoma and Protein Losing Enteropathy.

    Science.gov (United States)

    Obasaju, Patience; Brondon, Jennifer; Mir, Sabina; Fordham, Lynn A; Lee, Sang; Blatt, Julie

    2018-05-01

    Neuroblastoma and protein losing enteropathy (PLE) are diagnoses commonly seen by oncologists and gastroenterologists, respectively. The concurrence of these 2 entities is rare, and not well explained. We describe the sixth case of PLE in a child with neuroblastoma, and the first for which genetic information is available. Tumor DNA had a mutation in the PTPN11 gene, which has been described in neuroblastoma, and in Noonan syndrome-a diagnosis in which neuroblastoma and PLE independently have been reported. Constitutional DNA was normal. Genetic studies in future patients will be needed to support the link between neuroblastoma and PLE.

  11. Induction of somatic mutations in some vegetatively Propagated ornamentals by gamma radiation

    International Nuclear Information System (INIS)

    Das, P.K.; Ghosh, P.; Dube, S.; Dhua, S.P.

    1974-01-01

    Attempts were made to produce mutations in some vegetatively propagated ornamentals by acute and chronic gamma irradiation. Rooted cutting of Chrysanthemums and dormant bulbs of Dahlias were exposed to 1.5, 2.5, 3.5 and 2.0, 3.0 kR of acute doses respectively. In chronic irradiation, potted plants of Bougainvillea, Hibiscus, Allamanda, Achania, Jasminum, Chrysanthemum were exposed to several dose rates at different isodose arcs in the gamma field. Isolated mutants are being vegetatively multiplied and some of them have already been stabilized as pure forms. (M.G.B.)

  12. Single-Cell Analysis of Human Pancreas Reveals Transcriptional Signatures of Aging and Somatic Mutation Patterns.

    Science.gov (United States)

    Enge, Martin; Arda, H Efsun; Mignardi, Marco; Beausang, John; Bottino, Rita; Kim, Seung K; Quake, Stephen R

    2017-10-05

    As organisms age, cells accumulate genetic and epigenetic errors that eventually lead to impaired organ function or catastrophic transformation such as cancer. Because aging reflects a stochastic process of increasing disorder, cells in an organ will be individually affected in different ways, thus rendering bulk analyses of postmitotic adult cells difficult to interpret. Here, we directly measure the effects of aging in human tissue by performing single-cell transcriptome analysis of 2,544 human pancreas cells from eight donors spanning six decades of life. We find that islet endocrine cells from older donors display increased levels of transcriptional noise and potential fate drift. By determining the mutational history of individual cells, we uncover a novel mutational signature in healthy aging endocrine cells. Our results demonstrate the feasibility of using single-cell RNA sequencing (RNA-seq) data from primary cells to derive insights into genetic and transcriptional processes that operate on aging human tissue. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Rapid targeted somatic mutation analysis of solid tumors in routine clinical diagnostics.

    Science.gov (United States)

    Magliacane, Gilda; Grassini, Greta; Bartocci, Paola; Francaviglia, Ilaria; Dal Cin, Elena; Barbieri, Gianluca; Arrigoni, Gianluigi; Pecciarini, Lorenza; Doglioni, Claudio; Cangi, Maria Giulia

    2015-10-13

    Tumor genotyping is an essential step in routine clinical practice and pathology laboratories face a major challenge in being able to provide rapid, sensitive and updated molecular tests. We developed a novel mass spectrometry multiplexed genotyping platform named PentaPanel to concurrently assess single nucleotide polymorphisms in 56 hotspots of the 5 most clinically relevant cancer genes, KRAS, NRAS, BRAF, EGFR and PIK3CA for a total of 221 detectable mutations. To both evaluate and validate the PentaPanel performance, we investigated 1025 tumor specimens of 6 different cancer types (carcinomas of colon, lung, breast, pancreas, and biliary tract, and melanomas), systematically addressing sensitivity, specificity, and reproducibility of our platform. Sanger sequencing was also performed for all the study samples. Our data showed that PentaPanel is a high throughput and robust tool, allowing genotyping for targeted therapy selection of 10 patients in the same run, with a practical turnaround time of 2 working days. Importantly, it was successfully used to interrogate different DNAs isolated from routinely processed specimens (formalin-fixed paraffin embedded, frozen, and cytological samples), covering all the requirements of clinical tests. In conclusion, the PentaPanel platform can provide an immediate, accurate and cost effective multiplex approach for clinically relevant gene mutation analysis in many solid tumors and its utility across many diseases can be particularly relevant in multiple clinical trials, including the new basket trial approach, aiming to identify appropriate targeted drug combination strategies.

  14. Novel mutations in the CDKL5 gene in complex genotypes associated with West syndrome with variable phenotype: First description of somatic mosaic state.

    Science.gov (United States)

    Jdila, Marwa Ben; Issa, Abir Ben; Khabou, Boudour; Rhouma, Bochra Ben; Kamoun, Fatma; Ammar-Keskes, Leila; Triki, Chahnez; Fakhfakh, Faiza

    2017-10-01

    West syndrome is a rare epileptic encephalopathy of early infancy, characterized by epileptic spasms, hypsarrhythmia, and psychomotor retardation beginning in the first year of life. The present study reports the clinical, molecular and bioinformatic investigation in the three studied West patients. The results revealed a complex genotype with more than one mutation in each patient including the known mutations c.1910C>G (P2, P3); c.2372A>C in P3 and c.2395C>G in P1 and novel variants including c.616G>A, shared by the three patients P1, P2 and P3; c.1403G>C shared by P2 and P3 and c.2288A>G in patient P1. All the mutations were at somatic mosaic state and were de novo in the patients except ones (c.2372A>C). To our knowledge; the somatic mosaic state is described for the first time in patients with West syndrome. Five identified mutations were located in the C-terminal domain of the protein, while the novel mutation (c.616G>A) was in the catalytic domain. Bioinformatic tools predicted that this latter is the most pathogenic substitution affecting 3D protein structure and the secondary mRNA structure. Complex genotype composed of different combinations of mutations in each patient seems to be related to the phenotype variability. Copyright © 2017. Published by Elsevier B.V.

  15. The JAK2 V617F somatic mutation, mortality and cancer risk in the general population

    DEFF Research Database (Denmark)

    Nielsen, Camilla; Birgens, Henrik S; Nordestgaard, Børge G

    2011-01-01

    .1-1.1). Multifactorially adjusted hazard ratios for any cancer, hematologic cancer and myeloproliferative cancer were 3.7 (1.7-8.0), 58 (13-261) and 161 (12-2,197), respectively. Corresponding hazard ratios were 1.2 (0.8-2.0), 2.3 (0.2-25), 1.3 (0.3-5.4) for men versus women, and 1.0 (1.0-1.1), 1.1 (0.9-1.2), 0.9 (0......JAK2 V617F is present in the majority of patients with myeloproliferative cancer; however, its prevalence and clinical significance in the general population is unknown. We screened for presence of the mutation in 10,507 participants from the Copenhagen City Heart Study with up to 17.6 years...

  16. [THE SOMATIC MUTATIONS AND ABERRANT METHYLATION AS POTENTIAL GENETIC MARKERS OF URINARY BLADDER CANCER].

    Science.gov (United States)

    Mikhailenko, D S; Kushlinskii, N E

    2016-02-01

    All around the world, more than 330 thousands cases of bladder cancer are registered annually hence representing actual problem of modern oncology. Still in demand are search and characteristic of new molecular markers of bladder cancer detecting in tumor cells from urinary sediment and having high diagnostic accuracy. The studies of last decade, especially using methods of genome-wide sequencing, permitted to receive a large amount of experimental data concerning development and progression of bladder cancer The review presents systematic analysis of publications available in PubMed data base mainly of last five years. The original studies of molecular genetic disorders under bladder cancer and meta-analyzes were considered This approach permitted to detected the most common local alterations of DNA under bladder cancer which can be detected using routine genetic methods indifferent clinical material and present prospective interest for development of test-systems. The molecular genetic markers of disease can be activating missense mutations in 7 and 10 exons of gene of receptor of growth factor of fibroblasts 3 (FGFR3), 9 and 20 exons of gene of Phosphatidylinositol-4,5-bi-phosphate-3-kinase (PIK3CA) and mutation in -124 and -146 nucleotides in promoter of gene of catalytic subunit telomerase (TERT). The development of test-systems on the basis of aberrant methylation of CpG-islets of genes-suppressors still is seemed as a difficult task because of differences in pattern of methylation of different primary tumors at various stages of clonal evolution of bladder cancer though they can be considered as potential markers.

  17. High-throughput in vivo genotoxicity testing: an automated readout system for the somatic mutation and recombination test (SMART.

    Directory of Open Access Journals (Sweden)

    Benoit Lombardot

    Full Text Available Genotoxicity testing is an important component of toxicity assessment. As illustrated by the European registration, evaluation, authorization, and restriction of chemicals (REACH directive, it concerns all the chemicals used in industry. The commonly used in vivo mammalian tests appear to be ill adapted to tackle the large compound sets involved, due to throughput, cost, and ethical issues. The somatic mutation and recombination test (SMART represents a more scalable alternative, since it uses Drosophila, which develops faster and requires less infrastructure. Despite these advantages, the manual scoring of the hairs on Drosophila wings required for the SMART limits its usage. To overcome this limitation, we have developed an automated SMART readout. It consists of automated imaging, followed by an image analysis pipeline that measures individual wing genotoxicity scores. Finally, we have developed a wing score-based dose-dependency approach that can provide genotoxicity profiles. We have validated our method using 6 compounds, obtaining profiles almost identical to those obtained from manual measures, even for low-genotoxicity compounds such as urethane. The automated SMART, with its faster and more reliable readout, fulfills the need for a high-throughput in vivo test. The flexible imaging strategy we describe and the analysis tools we provide should facilitate the optimization and dissemination of our methods.

  18. Genetic signatures from amplification profiles characterize DNA mutation in somatic and radiation-induced sports of chrysanthemum

    International Nuclear Information System (INIS)

    Trigiano, R.N.; Scott, M.C.; Caetano-Anolles, G.

    1998-01-01

    The chrysanthemum (Dendranthema grandiflora Tzvelev.) cultivars 'Dark Charm', 'Salmon Charm', 'Coral Charm' and 'Dark Bronze Charm' are either radiation-induced mutants or spontaneous sports of 'Charm' and constitute a family or series of plants that primarily differ in flower color. These cultivars, which were difficult to differentiate genetically by DNA amplification fingerprinting (DAF), were easily identified by using arbitrary signatures from amplification profiles (ASAP). Genomic DNA was first amplified with three standard octamer arbitrary primers, all of which produced monomorphic profiles. Products from each of these DNA fingerprints were subsequently reamplified using four minihairpin decamer primers. The 12 primer combinations produced signatures containing approximately 37% polymorphic character loci, which were used to estimate genetic relationships between cultivars. Forty-six (32%) unique amplification products were associated with individual cultivars. The number of ASAP polymorphisms detected provided an estimate of the mutation rate in the mutant cultivars, ranging from 0.03% to 1.6% of nucleotide changes within an average of 18 kb of arbitrary amplified DAF sequence. The ASAP technique permits the clear genetic identification of somatic mutants and radiation-induced sports that are genetically highly homogeneous and should facilitate marker assisted breeding and protection of plant breeders rights of varieties or cultivars

  19. Novel biallelic mutations in MSH6 and PMS2 genes: gene conversion as a likely cause of PMS2 gene inactivation.

    Science.gov (United States)

    Auclair, Jessie; Leroux, Dominique; Desseigne, Françoise; Lasset, Christine; Saurin, Jean Christophe; Joly, Marie Odile; Pinson, Stéphane; Xu, Xiao Li; Montmain, Gilles; Ruano, Eric; Navarro, Claudine; Puisieux, Alain; Wang, Qing

    2007-11-01

    Since the first report by our group in 1999, more than 20 unrelated biallelic mutations in DNA mismatch repair genes (MMR) have been identified. In the present report, we describe two novel cases: one carrying compound heterozygous mutations in the MSH6 gene; and the other, compound heterozygous mutations in the PMS2 gene. Interestingly, the inactivation of one PMS2 allele was likely caused by gene conversion. Although gene conversion has been suggested to be a mutation mechanism underlying PMS2 inactivation, this is the first report of its involvement in a pathogenic mutation. The clinical features of biallelic mutation carriers were similar to other previously described patients, with the presence of café-au-lait spots (CALS), early onset of brain tumors, and colorectal neoplasia. Our data provide further evidence of the existence, although rare, of a distinct recessively inherited syndrome on the basis of MMR constitutional inactivation. The identification of this syndrome should be useful for genetic counseling, especially in families with atypical hereditary nonpolyposis colon cancer (HNPCC) associated with childhood cancers, and for the clinical surveillance of these mutation carriers. 2007 Wiley-Liss, Inc.

  20. Inactivating Mutation screening of Exon 6 and Exon 10E of FSHR gene in women with Polycystic Ovarian Syndrome in Vellore population

    Science.gov (United States)

    Sekar, Nishu; Sapre, Madhura; Kale, Vaikhari; Prabhu, Yogamaya D.; Renu, Kaviyarasi; Ramgir, Shalaka S.; Abilash, V. G.

    2017-11-01

    Polycystic Ovarian syndrome (PCOS) is a major cause of infertility in females of reproducing age and is typified by oligo-anovulation, hyperandrogenism, hirsutism and polycystic ovaries. FSHR gene located on chromosome 2 p21 is responsible for the normal follicular development and any deletion or mutation in the gene affects the interaction of FSH with its receptor. Thus, it becomes the candidate gene for PCOS study. Inactivating mutation in FSHR gene limits the receptor’s function by creating a complete block, changing the receptor-ligand complex or the basic hormone signal transduction.To screen the inactivating mutations in Exon 6 and Exon 10E of FSHR gene in women diagnosed with PCOS.PCR-RFLP analysis indicated that there were no inactivating mutations found in Exon 6 and Exon 10E. Variations in hormone levels were seen amongst the PCOS patients. There were no inactivating mutations found in FSHR gene of the women diagnosed with PCOS according to the Rotterdam criteria in Vellore population.

  1. Sex-related hearing impairment in Wolfram syndrome patients identified by inactivating WFS1 mutations

    NARCIS (Netherlands)

    Pennings, RJE; Huygen, PLM; van den Ouweland, JMW; Cryns, K; Dikkeschei, LD; Van Camp, G; Cremers, CWRJ

    2004-01-01

    This study examined the audiovestibular profile of 11 Wolfram syndrome patients (4 males, 7 females) from 7 families, with identified WFS1 mutations, and the audiometric profile of 17 related heterozygous carriers of WFS1 mutations. Patients with Wolfram syndrome showed a downsloping audiogram and

  2. Sex-related hearing impairment in Wolfram syndrome patients identified by inactivating WFS1 mutations.

    NARCIS (Netherlands)

    Pennings, R.J.E.; Huygen, P.L.M.; Ouweland, J.M.W. van den; Cryns, K.; Dikkeschei, L.D.; Camp, G. van; Cremers, C.W.R.J.

    2004-01-01

    This study examined the audiovestibular profile of 11 Wolfram syndrome patients (4 males, 7 females) from 7 families, with identified WFS1 mutations, and the audiometric profile of 17 related heterozygous carriers of WFS1 mutations. Patients with Wolfram syndrome showed a downsloping audiogram and

  3. [Comparative study of effect of infrared, submillimeter, and millimeter electromagnetic radiation on wing somatic mutations in Drosophila melanogaster induced by gamma-irradiation].

    Science.gov (United States)

    Fedorov, V I; Pogodin, A S; Dubatolova, T D; Varlamov, A V; Leont'ev, K V; Khamoian, A G

    2001-01-01

    It was shown that the number of spontaneous and gamma-radiation-induced somatic mutations in wing cells of fruit flies (third instar larvae) exposed to laser irradiation of submillimeter range (lambda = 81.5 microns) was significantly lower than in control. Laser irradiation did not affect the number of recombinations. Exposure to laser radiation in the infrared range and electromagnetic waves of the millimeter range (lambda = 3.8 mm) enhanced the effect of gamma-irradiation.

  4. To Screen Inactivation Mutation of Exon 1 of FSHR Gene in Polycystic Ovarian Syndrome: A South Indian Cohort Study

    Science.gov (United States)

    Sekar, Nishu; Yeole, Samiksha; Pradeep, Rashmi; Prabhu, Yogamaya D.; Renu, Kaviyarasi; Ramgir, Shalaka S.; Abilash, V. G.

    2017-11-01

    Polycystic ovary syndrome is an endocrine disorder. Irregular menstrual cycle, acne, facial hair and elevated androgen levels are the most common signs for PCOS. PCOS has an estimated prevalence of 4-12% among reproductive age women, thus making it a forerunner in female infertility. FSHR plays an important role in FSH signaling pathway making it an important gene for PCOS. In this study, we aim to focus on any association between the FSHR gene and PCOS. Our study was to evaluate any polymorphism of exon 1 of FSHR gene associated with PCOS.PCR-RFLP technique was performed on the PCOS samples. Hormonal changes were found in the patients. Exon 1 inactivation mutation of FSHR gene was not observed in the patient sample. A study of this association needs to be done using large sample size.

  5. Somatic mosaicism containing double mutations in PTCH1 revealed by generation of induced pluripotent stem cells from nevoid basal cell carcinoma syndrome.

    Science.gov (United States)

    Ikemoto, Yu; Takayama, Yoshinaga; Fujii, Katsunori; Masuda, Mokuri; Kato, Chise; Hatsuse, Hiromi; Fujitani, Kazuko; Nagao, Kazuaki; Kameyama, Kohzoh; Ikehara, Hajime; Toyoda, Masashi; Umezawa, Akihiro; Miyashita, Toshiyuki

    2017-08-01

    Nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant disorder characterised by developmental defects and tumorigenesis, such as medulloblastomas and basal cell carcinomas, caused by mutations of the patched-1 ( PTCH1 ) gene. In this article, we seek to demonstrate a mosaicism containing double mutations in PTCH1 in an individual with NBCCS. A de novo germline mutation of PTCH1 (c.272delG) was detected in a 31-year-old woman with NBCCS. Gene analysis of two out of four induced pluripotent stem cell (iPSC) clones established from the patient unexpectedly revealed an additional mutation, c.274delT. Deep sequencing confirmed a low-prevalence somatic mutation (5.5%-15.6% depending on the tissue) identical to the one found in iPSC clones. This is the first case of mosaicism unequivocally demonstrated in NBCCS. Furthermore, the mosaicism is unique in that the patient carries one normal and two mutant alleles. Because these mutations are located in close proximity, reversion error is likely to be involved in this event rather than a spontaneous mutation. In addition, this study indicates that gene analysis of iPSC clones can contribute to the detection of mosaicism containing a minor population carrying a second mutation. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  6. Association of Exon 10A and 10B inactivating mutation of follicle stimulating hormone receptor gene (FSHR) and Polycystic Ovarian Syndrome in Vellore cohort

    Science.gov (United States)

    Sekar, Nishu; Kulkarni, Rucha; Ozalkar, Sharvari; Prabhu, Yogamaya D.; Renu, Kaviyarasi; Ramgir, Shalaka S.; Abilash, V. G.

    2017-11-01

    Polycystic ovarian syndrome is the most common heterogenous endocrine disorder in women. Follicle stimulating hormone receptor is associated with normal development as well as maturation of follicles and triggers estrogen production in granulosa cells of the ovary. Inactivating mutation in FSHR gene correlated with reduction of ovarian function in women is due to damage to receptor function. This study aims to investigate whether inactivating mutations, in follicle stimulating hormone receptor gene is related to polycystic ovarian morphology in women with PCOS. Genomic DNA isolated from 15 subjects from Sandhya Hospital, Vellore (10 patients with PCOS and 5 healthy controls) was taken for this study. Patient data included a clinical report, hormonal levels, and ovarian morphological details. DNA isolation was followed by DNA amplification by polymerase chain reaction using Exon 10 A and Exon 10 B primers. The PCR-RFLP analysis was performed using Dde1 restriction enzyme. Here we discuss inactivating mutation found in Exon 10 of FSHR gene in patients with PCOS.The absence of inactivating mutation was observed through PCR-RFLP study on Exon 10A and Exon 10B.

  7. Somatic and germline mosaicism for a mutation of the PHEX gene can lead to genetic transmission of X-linked hypophosphatemic rickets that mimics an autosomal dominant trait.

    Science.gov (United States)

    Goji, Katsumi; Ozaki, Kayo; Sadewa, Ahmad H; Nishio, Hisahide; Matsuo, Masafumi

    2006-02-01

    Familial hypophosphatemic rickets is usually transmitted as an X-linked dominant disorder (XLH), although autosomal dominant forms have also been observed. Genetic studies of these disorders have identified mutations in PHEX and FGF23 as the causes of X-linked dominant disorder and autosomal dominant forms, respectively. The objective of the study was to describe the molecular genetic findings in a family affected by hypophosphatemic rickets with presumed autosomal dominant inheritance. We studied a family in which the father and the elder of his two daughters, but not the second daughter, were affected by hypophosphatemic rickets. The pedigree interpretation of the family suggested that genetic transmission of the disorder occurred as an autosomal dominant trait. Direct nucleotide sequencing of FGF23 and PHEX revealed that the elder daughter was heterozygous for an R567X mutation in PHEX, rather than FGF23, suggesting that the genetic transmission occurred as an X-linked dominant trait. Unexpectedly, the father was heterozygous for this mutation. Single-nucleotide primer extension and denaturing HPLC analysis of the father using DNA from single hair roots revealed that he was a somatic mosaic for the mutation. Haplotype analysis confirmed that the father transmitted the genotypes for 18 markers on the X chromosome equally to his two daughters. The fact that the father transmitted the mutation to only one of his two daughters indicated that he was a germline mosaic for the mutation. Somatic and germline mosaicism for an X-linked dominant mutation in PHEX may mimic autosomal dominant inheritance.

  8. Somatic mutation frequency in the stamen hairs of Tradescantia KU 7 and KU 9 clones exposed to low-level gamma rays

    International Nuclear Information System (INIS)

    Ichikawa, S.; Nagashima, C.; Takahashi, C.S.

    1981-01-01

    Two triploid clones (KU 7 and KU 9) of Tradescantia heterozygous for flower color were exposed to 1 to 42.3R of gamma rays or the scattering radiation in the gamma field of the Institute of Radiation . Breeding. Occurrence of somatic pink mutations in the stamen hairs was investigated 10 to 16 (or 14) days after irradiation. The mutation frequency was found to increase linearly with increasing gamma-ray exposure in the both clones, and the frequencies of 0.437 and 0.468 pink mutant events per 10 3 hairs per R were determined for KU 7 and KU 9, respectively. When the data collected in the present study were analyzed together with those obtained in earlier experiments in the gamma field, linear relationships of the somatic mutation frequency with gamma-ray (2.1 to 201.6R) and scattering radiation (0.72 to 57.6R) exposures were confirmed. Scattering radiation was found to have a genetical efficiency more than two times higher than that of gamma rays. Variation of spontaneous mutation frequency observed in the present study and in earlier studies was inversely correlated to temperature variation

  9. Frequency of Somatic TP53 Mutations in Combination with Known Pathogenic Mutations in Colon Adenocarcinoma, Non–Small Cell Lung Carcinoma, and Gliomas as Identified by Next-Generation Sequencing

    Directory of Open Access Journals (Sweden)

    Zahra Shajani-Yi

    2018-03-01

    Full Text Available The tumor suppressor gene TP53 is the most frequently mutated gene in human cancer. It encodes p53, a DNA-binding transcription factor that regulates multiple genes involved in DNA repair, metabolism, cell cycle arrest, apoptosis, and senescence. TP53 is associated with human cancer by mutations that lead to a loss of wild-type p53 function as well as mutations that confer alternate oncogenic functions that enable them to promote invasion, metastasis, proliferation, and cell survival. Identifying the discrete TP53 mutations in tumor cells may help direct therapies that are more effective. In this study, we identified the frequency of individual TP53 mutations in patients with colon adenocarcinoma (48%, non–small cell lung carcinoma (NSCLC (36%, and glioma/glioblastoma (28% at our institution using next-generation sequencing. We also identified the occurrence of somatic mutations in numerous actionable genes including BRAF, EGFR, KRAS, IDH1, and PIK3CA that occurred concurrently with these TP53 mutations. Of the 480 tumors examined that contained one or more mutations in the TP53 gene, 219 were colon adenocarcinomas, 215 were NSCLCs, and 46 were gliomas/glioblastomas. Among the patients positive for TP53 mutations diagnosed with colon adenocarcinoma, 50% also showed at least one mutation in pathogenic genes of which 14% were BRAF, 33% were KRAS, and 3% were NRAS. Forty-seven percent of NSCLC patients harboring TP53 mutations also had a mutation in at least one actionable pathogenic variant with the following frequencies: BRAF: 4%, EGFR: 10%, KRAS: 28%, and PIK3CA: 4%. Fifty-two percent of patients diagnosed with glioma/glioblastoma with a positive TP53 mutation had at least one concurrent mutation in a known pathogenic gene of which 9% were CDKN2A, 41% were IDH1, and 11% were PIK3CA.

  10. A Site Specific Model And Analysis Of The Neutral Somatic Mutation Rate In Whole-Genome Cancer Data

    DEFF Research Database (Denmark)

    Bertl, Johanna; Guo, Qianyun; Rasmussen, Malene Juul

    2017-01-01

    Detailed modelling of the neutral mutational process in cancer cells is crucial for identifying driver mutations and understanding the mutational mechanisms that act during cancer development. The neutral mutational process is very complex: whole-genome analyses have revealed that the mutation ra...

  11. Somatic mutation frequencies in the stamen hairs of stable and mutable clones of Tradescantia after acute gamma-ray treatments with small doses

    International Nuclear Information System (INIS)

    Ichikawa, Sadao; Takahashi, C.S.

    1977-01-01

    Young inflorescences of two different Tradescantia clones heterozygous for flower and stamen-hair color, one stable (KU 9) and the other spontaneously mutable (KU 20), were irradiated acutely with small doses (approx. 3 to 50 R) of 60 Co gamma-rays. Somatic mutation frequencies from blue to pink in the stamen hairs scored on post-irradiation days 10 to 16 increased essentially linearly with increasing gamma-ray dose in both clones. Despite about a 5-fold difference in spontaneous mutation frequency per hair found between the two clones, the dose-response curves of pink mutations determined were similar to each other, giving average mutation frequencies of 1.51 and 1.41 pink-mutant events per 1000 hairs per R for KU 9 and KU 20, respectively. These frequencies are comparable to earlier results obtained from acute irradiation treatments of other clones with higher doses. The doubling dose of pink mutation (the radiation dose making the mutation frequency double the spontaneous level) was calculated to be 2.09 R for KU 9, and this low doubling dose must be given full attention. On the other hand, the doubling dose for KU 20 (calculated to be 10.4 R) is of questionable value, being greatly subject to change because of the diversely variable spontaneous mutation frequency of this clone

  12. Relevance of the immunoglobulin VH somatic mutation status in patients with chronic lymphocytic leukemia treated with fludarabine, cyclophosphamide, and rituximab (FCR) or related chemoimmunotherapy regimens.

    Science.gov (United States)

    Lin, Katherine I; Tam, Constantine S; Keating, Michael J; Wierda, William G; O'Brien, Susan; Lerner, Susan; Coombes, Kevin R; Schlette, Ellen; Ferrajoli, Alessandra; Barron, Lynn L; Kipps, Thomas J; Rassenti, Laura; Faderl, Stefan; Kantarjian, Hagop; Abruzzo, Lynne V

    2009-04-02

    Although immunoglobulin V(H) mutation status (IgV(H) MS) is prognostic in patients with chronic lymphocytic leukemia (CLL) who are treated with alkylating agents or single-agent fludarabine, its significance in the era of chemoimmunotherapy is not known. We determined the IgV(H) somatic mutation status (MS) in 177 patients enrolled in a phase 2 study of fludarabine, cyclophosphamide, and rituximab (FCR) and in 127 patients treated with subsequent chemoimmunotherapy protocols. IgV(H) MS did not impact significantly on the complete remission (CR) rate of patients receiving FCR or related regimens. However, CR duration was significantly shorter in patients with CLL that used unmutated IgV(H) than those whose CLL used mutated IgV(H) (TTP 47% vs 82% at 6 years, P IgV(H) MS emerged as the only determinant of remission duration (hazard ratio 3.8, P IgV(H) status.

  13. Molecular spectrum of KRAS, NRAS, BRAF, PIK3CA, TP53, and APC somatic gene mutations in Arab patients with colorectal cancer: determination of frequency and distribution pattern

    Science.gov (United States)

    Al-Shamsi, Humaid O.; Jones, Jeremy; Fahmawi, Yazan; Dahbour, Ibrahim; Tabash, Aziz; Abdel-Wahab, Reham; Abousamra, Ahmed O. S.; Shaw, Kenna R.; Xiao, Lianchun; Hassan, Manal M.; Kipp, Benjamin R.; Kopetz, Scott; Soliman, Amr S.; McWilliams, Robert R.; Wolff, Robert A.

    2016-01-01

    Background The frequency rates of mutations such as KRAS, NRAS, BRAF, and PIK3CA in colorectal cancer (CRC) differ among populations. The aim of this study was to assess mutation frequencies in the Arab population and determine their correlations with certain clinicopathological features. Methods Arab patients from the Arab Gulf region and a population of age- and sex-matched Western patients with CRC whose tumors were evaluated with next-generation sequencing (NGS) were identified and retrospectively reviewed. The mutation rates of KRAS, NRAS, BRAF, PIK3CA, TP53, and APC were recorded, along with clinicopathological features. Other somatic mutation and their rates were also identified. Fisher’s exact test was used to determine the association between mutation status and clinical features. Results A total of 198 cases were identified; 99 Arab patients and 99 Western patients. Fifty-two point seven percent of Arab patients had stage IV disease at initial presentation, 74.2% had left-sided tumors. Eighty-nine point two percent had tubular adenocarcinoma and 10.8% had mucinous adenocarcinoma. The prevalence rates of KRAS, NRAS, BRAF, PIK3CA, TP53, APC, SMAD, FBXW7 mutations in Arab population were 44.4%, 4%, 4%, 13.1%, 52.5%, 27.3%, 2% and 3% respectively. Compared to 48.4%, 4%, 4%, 12.1%, 47.5%, 24.2%, 11.1% and 0% respectively in matched Western population. Associations between these mutations and patient clinicopathological features were not statistically significant. Conclusions This is the first study to report comprehensive hotspot mutations using NGS in Arab patients with CRC. The frequency of KRAS, NRAS, BRAF, TP53, APC and PIK3CA mutations were similar to reported frequencies in Western population except SMAD4 that had a lower frequency and higher frequency of FBXW7 mutation. PMID:28078112

  14. Germ-line mutations of the p53 tumor suppressor gene in patients with high risk for cancer inactivate the p53 protein.

    Science.gov (United States)

    Frebourg, T; Kassel, J; Lam, K T; Gryka, M A; Barbier, N; Andersen, T I; Børresen, A L; Friend, S H

    1992-07-15

    Germ-line mutations in the p53 tumor suppressor gene have been observed in patients with Li-Fraumeni syndrome, brain tumors, second malignancies, and breast cancers. It is unclear whether all of these mutations have inactivated p53 and thereby provide an increased risk for cancer. Therefore, it is necessary to establish the biological significance of these germ-line mutations by the functional and structural analysis of the resulting mutant p53 proteins. We analyzed the ability of seven germ-line mutant proteins observed in patients with Li-Fraumeni syndrome, second primary neoplasms, or familial breast cancer to block the growth of malignant cells and compared the structural properties of the mutant proteins to that of the wild-type protein. Six of seven missense mutations disrupted the growth inhibitory properties and structure of the wild-type protein. One germ-line mutation retained the features of the wild-type p53. Genetic analysis of the breast cancer family in which this mutation was observed indicated that this germ-line mutation was not associated with the development of cancer. These results demonstrate that germ-line p53 mutations observed in patients with Li-Fraumeni syndrome and with second malignancies have inactivated the p53 tumor suppressor gene. The inability of the germ-line p53 mutants to block the growth of malignant cells can explain why patients with these germ-line mutations have an increased risk for cancer. The observation of a functionally silent germ-line mutation indicates that, before associating a germ-line tumor suppressor gene mutation with cancer risk, it is prudent to consider its functional significance.

  15. Germ-line mutations of the p53 tumor suppressor gene in patients with high risk for cancer inactivate the p53 protein.

    Science.gov (United States)

    Frebourg, T; Kassel, J; Lam, K T; Gryka, M A; Barbier, N; Andersen, T I; Børresen, A L; Friend, S H

    1992-01-01

    Germ-line mutations in the p53 tumor suppressor gene have been observed in patients with Li-Fraumeni syndrome, brain tumors, second malignancies, and breast cancers. It is unclear whether all of these mutations have inactivated p53 and thereby provide an increased risk for cancer. Therefore, it is necessary to establish the biological significance of these germ-line mutations by the functional and structural analysis of the resulting mutant p53 proteins. We analyzed the ability of seven germ-line mutant proteins observed in patients with Li-Fraumeni syndrome, second primary neoplasms, or familial breast cancer to block the growth of malignant cells and compared the structural properties of the mutant proteins to that of the wild-type protein. Six of seven missense mutations disrupted the growth inhibitory properties and structure of the wild-type protein. One germ-line mutation retained the features of the wild-type p53. Genetic analysis of the breast cancer family in which this mutation was observed indicated that this germ-line mutation was not associated with the development of cancer. These results demonstrate that germ-line p53 mutations observed in patients with Li-Fraumeni syndrome and with second malignancies have inactivated the p53 tumor suppressor gene. The inability of the germ-line p53 mutants to block the growth of malignant cells can explain why patients with these germ-line mutations have an increased risk for cancer. The observation of a functionally silent germ-line mutation indicates that, before associating a germ-line tumor suppressor gene mutation with cancer risk, it is prudent to consider its functional significance. Images PMID:1631137

  16. A Somatic HIF2α Mutation-Induced Multiple and Recurrent Pheochromocytoma/Paraganglioma with Polycythemia: Clinical Study with Literature Review.

    Science.gov (United States)

    Liu, Qiuli; Wang, Yan; Tong, Dali; Liu, Gaolei; Yuan, Wenqiang; Zhang, Jun; Ye, Jin; Zhang, Yao; Yuan, Gang; Feng, Qingxing; Zhang, Dianzheng; Jiang, Jun

    2017-03-01

    A syndrome known as pheochromocytomas (PCC)/paragangliomas (PGL) and polycythemia resulted from gain-of-function mutation of hypoxia-inducible factor 2α (HIF2α) has been reported recently. However, clinical features of this syndrome vary from patient to patient. In our study, we described the clinical features of the patient within 15-year follow-up with a literature review. The patient presented with "red face" since childhood and was diagnosed with polycythemia and pheochromocytoma in 2000, and then, tumor was removed at his age of 27 (year 2000). However, 13 years later (2013), he was diagnosed with multiple paragangliomas. Moreover, 2 years later (2015), another two paragangaliomas were also confirmed. Genetic analysis of hereditary PCC/PGL-related genes was conducted. A somatic heterozygous missense mutation of HIF2α (c.1589C>T) was identified at exon 12, which is responsible for the elevated levels of HIF2α and erythropoietin (EPO) and subsequent development of paragangaliomas. However, this mutation was only found in the tumors from three different areas, not in the blood. So far, 13 cases of PCC/PGL with polycythemia have been reported. Among them, somatic mutations of HIF2α at exon 12 are responsible for 12 cases, and only 1 case was caused by germline mutation of HIF2α at exon 9. The HIF2α mutation-induced polycythemia with PCC/PGL is a rare syndrome with no treatment for cure. Comprehensive therapies for this disease include removal of the tumors and intermittent phlebotomies; administration of medications to control blood pressure and to prevent complications or death resulted from high concentration of red blood cell (RBC). Genetic test is strongly recommended for patients with early onset of polycythemia and multiple/recurrent PCC/PGL.

  17. Recent advances in understanding Cushing disease: resistance to glucocorticoid negative feedback and somatic USP8 mutations [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Eleni Daniel

    2017-05-01

    Full Text Available Cushing’s disease is a rare disease with a characteristic phenotype due to significant hypercortisolism driven by over-secretion of adrenocorticotropic hormone and to high morbidity and mortality if untreated. It is caused by a corticotroph adenoma of the pituitary, but the exact mechanisms leading to tumorigenesis are not clear. Recent advances in molecular biology such as the discovery of somatic mutations of the ubiquitin-specific peptidase 8 (USP8 gene allow new insights into the pathogenesis, which could be translated into exciting and much-needed therapeutic applications.

  18. Non-hyperfunctioning nodules from multinodular goiters: a minor role in pathogenesis for somatic activating mutations in the TSH-receptor and Gsalpha subunit genes.

    Science.gov (United States)

    Derrien, C; Sonnet, E; Gicquel, I; Le Gall, J Y; Poirier, J Y; David, V; Maugendre, D

    2001-05-01

    Constitutive activation of the cAMP pathway stimulates thyrocyte proliferation. Gain-of-function mutations in Gsalpha protein have already been identified in thyroid nodules which have lost the ability to trap iodine. In contrast, most of the studies failed to detect somatic activating mutations in the thyrotropin receptor (TSH-R) in non-hyperfunctioning thyroid tumors. The aim of this study was to screen for mutations TSH-R exon 10, encoding the whole intracytoplasmic area involved in signal transduction, and Gsalpha exons 8 and 9, containing the two hot-spot codons 201 and 227, in a subset of non-hyperfunctioning nodules from multinodular goiter. Identified by matching ultrasonography and scintiscan, 22 eufunctioning (normal 99Tc uptake) and 15 nonfunctioning (decreased 99Tc uptake) nodules from 27 non-toxic multinodular goiters were isolated. After DNA extraction, TSH-R exon 10 was analyzed by direct sequencing of the PCR products and Gsalpha exons 8 and 9 by Denaturing Gradient Gel Electrophoresis. No mutation of TSH-R or Gsalpha was detected in the 37 nodules analyzed. This absence of mutation, despite the use of two sensitive screening methods associated with the analysis of the TSH-R whole intracytoplasmic area and Gsalpha two hot-spot codons, suggests that TSH-R and Gsalpha play a minor role in the pathogenesis of non-toxic nodules from multinodular goiters.

  19. Origin of Somatic Mutations in β-Catenin versus Adenomatous Polyposis Coli in Colon Cancer: Random Mutagenesis in Animal Models versus Nonrandom Mutagenesis in Humans.

    Science.gov (United States)

    Yang, Da; Zhang, Min; Gold, Barry

    2017-07-17

    Wnt signaling is compromised early in the development of human colorectal cancer (CRC) due to truncating nonsense mutations in adenomatous polyposis coli (APC). CRC induced by chemical carcinogens, such as heterocyclic aromatic amines and azoxymethane, in mice also involves dysregulation of Wnt signaling but via activating missense mutations in the β-catenin oncogene despite the fact that genetically modified mice harboring an inactive APC allele efficiently develop CRC. In contrast, activating mutations in β-catenin are rarely observed in human CRC. Dysregulation of the Wnt signaling pathway by the two distinct mechanisms reveals insights into the etiology of human CRC. On the basis of calculations related to DNA adduct levels produced in mouse CRC models using mutagens, and the number of stem cells in the mouse colon, we show that two nonsense mutations required for biallelic disruption of APC are statistically unlikely to produce CRC in experiments using small numbers of mice. We calculate that an activating mutation in one allele near the critical GSK3β phosphorylation site on β-catenin is >10 5 -times more likely to produce CRC by random mutagenesis due to chemicals than inactivating two alleles in APC, yet it does not occur in humans. Therefore, the mutagenesis mechanism in human CRC cannot be random. We explain that nonsense APC mutations predominate in human CRC because of deamination at 5-methylcytosine at CGA and CAG codons, coupled with the number of human colonic stem cells and lifespan. Our analyses, including a comparison of mutation type and age at CRC diagnosis in U.S. and Chinese patients, also indicate that APC mutations in CRC are not due to environmental mutagens that randomly damage DNA.

  20. Somatic mutation and recombination induced with reactor thermal neutrons in Drosophila melanogaster; Mutacion y recombinacion somaticas inducidas con neutrones termicos de reactor en Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Zambrano A, F.; Guzman R, J.; Paredes G, L.; Delfin L, A. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    The SMART test of Drosophila melanogaster was used to quantify the effect over the somatic mutation and recombination induced by thermal and fast neutrons at the TRIGA Mark III reactor of the ININ at the power of 300 k W for times of 30, 60 and 120 minutes with total equivalent doses respectively of 20.8, 41.6 and 83.2 Sv. A linear relation between the radiation equivalent dose and the frequency of the genetic effects such as mutation and recombination was observed. The obtained results allow to conclude that SMART is a sensitive system to the induced damage by neutrons, so this can be used for studying its biological effects. (Author)

  1. Depolarized inactivation overcomes impaired activation to produce DRG neuron hyperexcitability in a Nav1.7 mutation in a patient with distal limb pain.

    Science.gov (United States)

    Huang, Jianying; Yang, Yang; Dib-Hajj, Sulayman D; van Es, Michael; Zhao, Peng; Salomon, Jody; Drenth, Joost P H; Waxman, Stephen G

    2014-09-10

    Sodium channel Nav1.7, encoded by SCN9A, is expressed in DRG neurons and regulates their excitability. Genetic and functional studies have established a critical contribution of Nav1.7 to human pain disorders. We have now characterized a novel Nav1.7 mutation (R1279P) from a female human subject with distal limb pain, in which depolarized fast inactivation overrides impaired activation to produce hyperexcitability and spontaneous firing in DRG neurons. Whole-cell voltage-clamp recordings in human embryonic kidney (HEK) 293 cells demonstrated that R1279P significantly depolarizes steady-state fast-, slow-, and closed-state inactivation. It accelerates deactivation, decelerates inactivation, and facilitates repriming. The mutation increases ramp currents in response to slow depolarizations. Our voltage-clamp analysis showed that R1279P depolarizes channel activation, a change that was supported by our multistate structural modeling. Because this mutation confers both gain-of-function and loss-of-function attributes on the Nav1.7 channel, we tested the impact of R1279P expression on DRG neuron excitability. Current-clamp studies reveal that R1279P depolarizes resting membrane potential, decreases current threshold, and increases firing frequency of evoked action potentials within small DRG neurons. The populations of spontaneously firing and repetitively firing neurons were increased by expressing R1279P. These observations indicate that the dominant proexcitatory gating changes associated with this mutation, including depolarized steady-state fast-, slow-, and closed-state inactivation, faster repriming, and larger ramp currents, override the depolarizing shift of activation, to produce hyperexcitability and spontaneous firing of nociceptive neurons that underlie pain. Copyright © 2014 the authors 0270-6474/14/3412328-13$15.00/0.

  2. Reduction of spontaneous somatic mutation frequency by a low-dose X irradiation of Drosophila larvae and possible involvement of DNA single-strand damage repair.

    Science.gov (United States)

    Koana, Takao; Takahashi, Takashi; Tsujimura, Hidenobu

    2012-03-01

    The third instar larvae of Drosophila were irradiated with X rays, and the somatic mutation frequency in their wings was measured after their eclosion. In the flies with normal DNA repair and apoptosis functions, 0.2 Gy irradiation at 0.05 Gy/min reduced the frequency of the so-called small spot (mutant cell clone with reduced reproductive activity) compared with that in the sham-irradiated flies. When apoptosis was suppressed using the baculovirus p35 gene, the small spot frequency increased four times in the sham-irradiated control group, but the reduction by the 0.2-Gy irradiation was still evident. In a non-homologous end joining-deficient mutant, the small spot frequency was also reduced by 0.2 Gy radiation. In a mutant deficient in single-strand break repair, no reduction in the small spot frequency by 0.2 Gy radiation was observed, and the small spot frequency increased with the radiation dose. Large spot (mutant cell clone with normal reproductive activity) frequency was not affected by suppression of apoptosis and increased monotonically with radiation dose in wild-type larvae and in mutants for single- or double-strand break repair. It is hypothesized that some of the small spots resulted from single-strand damage and, in wild-type larvae, 0.2 Gy radiation activated the normal single-strand break repair gene, which reduced the background somatic mutation frequency.

  3. Inactivation of Smad4 in gastric carcinomas.

    Science.gov (United States)

    Powell, S M; Harper, J C; Hamilton, S R; Robinson, C R; Cummings, O W

    1997-10-01

    Allelic loss of chromosome 18q has been noted in intestinal type gastric adenocarcinomas. Smad4 is a gene located at 18q that was recently cloned in humans and found to be significantly altered in pancreatic cancers. We sought to determine whether Smad4 genetic alterations played a significant role in gastric tumorigenesis by studying 35 gastric adenocarcinomas of all histopathological types and pathological stages. Microdissected specimens were used for mutational analysis of Smad4 at the nucleotide level, including the entire coding region and intron/exon boundaries. Allelic imbalance was also analyzed at the Smad4 locus using two nearby microsatellite markers. One case of apparent biallelic inactivation of Smad4 was found in our study of 35 gastric carcinomas. A nonsense point mutation at codon 334 was demonstrated, which, similar to other Smad4 mutations, is predicted to truncate the conserved COOH-terminal domain of this protein. This Smad4 C to T transition mutation was proven to be somatically acquired. Allelic loss was also noted on chromosome 18q at a marker near Smad4 in this mutated gastric cancer, apparently producing complete inactivation of Smad4 in this tumor. Significant 18q allelic loss (56% of 34 informative cases) was noted in our gastric carcinomas using microsatellite markers near the Smad4 locus, regardless of histological subtype or pathological stage. Additionally, three cases of microsatellite instability were observed. Thus, Smad4 inactivation was noted in our gastric carcinomas; however, this event was rare. The frequent loss of chromosomal arm 18q observed in gastric cancers suggests the presence of other tumor suppressor genes in this region that are involved in gastric tumorigenesis. Further studies are needed to identify these other targets of inactivation during gastric cancer development.

  4. Impact of somatic PI3K pathway and ERBB family mutations on pathological complete response (pCR) in HER2-positive breast cancer patients who received neoadjuvant HER2-targeted therapies.

    LENUS (Irish Health Repository)

    Toomey, Sinead

    2017-07-27

    The Cancer Genome Atlas analysis revealed that somatic EGFR, receptor tyrosine-protein kinase erbB-2 (ERBB2), Erb-B2 receptor tyrosine kinase 3 (ERBB3) and Erb-B2 receptor tyrosine kinase 4 (ERBB4) gene mutations (ERBB family mutations) occur alone or co-occur with somatic mutations in the gene encoding the phosphatidylinositol 3-kinase (PI3K) catalytic subunit (PIK3CA) in 19% of human epidermal growth factor receptor 2 (HER2)-positive breast cancers. Because ERBB family mutations can activate the PI3K\\/AKT pathway and likely have similar canonical signalling effects to PI3K pathway mutations, we investigated their combined impact on response to neoadjuvant HER2-targeted therapies.

  5. A site specific model and analysis of the neutral somatic mutation rate in whole-genome cancer data.

    Science.gov (United States)

    Bertl, Johanna; Guo, Qianyun; Juul, Malene; Besenbacher, Søren; Nielsen, Morten Muhlig; Hornshøj, Henrik; Pedersen, Jakob Skou; Hobolth, Asger

    2018-04-19

    Detailed modelling of the neutral mutational process in cancer cells is crucial for identifying driver mutations and understanding the mutational mechanisms that act during cancer development. The neutral mutational process is very complex: whole-genome analyses have revealed that the mutation rate differs between cancer types, between patients and along the genome depending on the genetic and epigenetic context. Therefore, methods that predict the number of different types of mutations in regions or specific genomic elements must consider local genomic explanatory variables. A major drawback of most methods is the need to average the explanatory variables across the entire region or genomic element. This procedure is particularly problematic if the explanatory variable varies dramatically in the element under consideration. To take into account the fine scale of the explanatory variables, we model the probabilities of different types of mutations for each position in the genome by multinomial logistic regression. We analyse 505 cancer genomes from 14 different cancer types and compare the performance in predicting mutation rate for both regional based models and site-specific models. We show that for 1000 randomly selected genomic positions, the site-specific model predicts the mutation rate much better than regional based models. We use a forward selection procedure to identify the most important explanatory variables. The procedure identifies site-specific conservation (phyloP), replication timing, and expression level as the best predictors for the mutation rate. Finally, our model confirms and quantifies certain well-known mutational signatures. We find that our site-specific multinomial regression model outperforms the regional based models. The possibility of including genomic variables on different scales and patient specific variables makes it a versatile framework for studying different mutational mechanisms. Our model can serve as the neutral null model

  6. NF2 tumor suppressor gene: a comprehensive and efficient detection of somatic mutations by denaturing HPLC and microarray-CGH.

    Science.gov (United States)

    Szijan, Irene; Rochefort, Daniel; Bruder, Carl; Surace, Ezequiel; Machiavelli, Gloria; Dalamon, Viviana; Cotignola, Javier; Ferreiro, Veronica; Campero, Alvaro; Basso, Armando; Dumanski, Jan P; Rouleau, Guy A

    2003-01-01

    The NF2 tumor suppressor gene, located in chromosome 22q12, is involved in the development of multiple tumors of the nervous system, either associated with neurofibromatosis 2 or sporadic ones, mainly schwannomas and meningiomas. In order to evaluate the role of the NF2 gene in sporadic central nervous system (CNS) tumors, we analyzed NF2 mutations in 26 specimens: 14 meningiomas, 4 schwannomas, 4 metastases, and 4 other histopathological types of neoplasms. Denaturing high performance liquid chromatography (denaturing HPLC) and comparative genomic hybridization on a DNA microarray (microarray- CGH) were used as scanning methods for small mutations and gross rearrangements respectively. Small mutations were identified in six out of seventeen meningiomas and schwannomas, one mutation was novel. Large deletions were detected in six meningiomas. All mutations were predicted to result in truncated protein or in the absence of a large protein domain. No NF2 mutations were found in other histopathological types of CNS tumors. These results provide additional evidence that mutations in the NF2 gene play an important role in the development of sporadic meningiomas and schwannomas. Denaturing HPLC analysis of small mutations and microarray-CGH of large deletions are complementary, fast, and efficient methods for the detection of mutations in tumor tissues.

  7. Mutations and epimutations in the origin of cancer

    Energy Technology Data Exchange (ETDEWEB)

    Peltomaeki, Paeivi, E-mail: Paivi.Peltomaki@Helsinki.Fi

    2012-02-15

    Cancer is traditionally viewed as a disease of abnormal cell proliferation controlled by a series of mutations. Mutations typically affect oncogenes or tumor suppressor genes thereby conferring growth advantage. Genomic instability facilitates mutation accumulation. Recent findings demonstrate that activation of oncogenes and inactivation of tumor suppressor genes, as well as genomic instability, can be achieved by epigenetic mechanisms as well. Unlike genetic mutations, epimutations do not change the base sequence of DNA and are potentially reversible. Similar to genetic mutations, epimutations are associated with specific patterns of gene expression that are heritable through cell divisions. Knudson's hypothesis postulates that inactivation of tumor suppressor genes requires two hits, with the first hit occurring either in somatic cells (sporadic cancer) or in the germline (hereditary cancer) and the second one always being somatic. Studies on hereditary and sporadic forms of colorectal carcinoma have made it evident that, apart from genetic mutations, epimutations may serve as either hit or both. Furthermore, recent next-generation sequencing studies show that epigenetic genes, such as those encoding histone modifying enzymes and subunits for chromatin remodeling systems, are themselves frequent targets of somatic mutations in cancer and can act like tumor suppressor genes or oncogenes. This review discusses genetic vs. epigenetic origin of cancer, including cancer susceptibility, in light of recent discoveries. Situations in which mutations and epimutations occur to serve analogous purposes are highlighted.

  8. MicroRNA genes and their target 3'-untranslated regions are infrequently somatically mutated in ovarian cancers.

    Directory of Open Access Journals (Sweden)

    Georgina L Ryland

    Full Text Available MicroRNAs are key regulators of gene expression and have been shown to have altered expression in a variety of cancer types, including epithelial ovarian cancer. MiRNA function is most often achieved through binding to the 3'-untranslated region of the target protein coding gene. Mutation screening using massively-parallel sequencing of 712 miRNA genes in 86 ovarian cancer cases identified only 5 mutated miRNA genes, each in a different case. One mutation was located in the mature miRNA, and three mutations were predicted to alter the secondary structure of the miRNA transcript. Screening of the 3'-untranslated region of 18 candidate cancer genes identified one mutation in each of AKT2, EGFR, ERRB2 and CTNNB1. The functional effect of these mutations is unclear, as expression data available for AKT2 and EGFR showed no increase in gene transcript. Mutations in miRNA genes and 3'-untranslated regions are thus uncommon in ovarian cancer.

  9. Distinct effects of the recurrent Mlh1G67R mutation on MMR functions, cancer, and meiosis

    OpenAIRE

    Avdievich, Elena; Reiss, Cora; Scherer, Stefan J.; Zhang, Yongwei; Maier, Sandra M.; Jin, Bo; Hou, Harry; Rosenwald, Andreas; Riedmiller, Hubertus; Kucherlapati, Raju; Cohen, Paula E.; Edelmann, Winfried; Kneitz, Burkhard

    2008-01-01

    Mutations in the human DNA mismatch repair (MMR) gene MLH1 are associated with hereditary nonpolyposis colorectal cancer (Lynch syndrome, HNPCC) and a significant proportion of sporadic colorectal cancer. The inactivation of MLH1 results in the accumulation of somatic mutations in the genome of tumor cells and resistance to the genotoxic effects of a variety of DNA damaging agents. To study the effect of MLH1 missense mutations on cancer susceptibility, we generated a mouse line carrying the ...

  10. Visualization portal for genetic variation (VizGVar): a tool for interactive visualization of SNPs and somatic mutations in exons, genes and protein domains.

    Science.gov (United States)

    Solano-Román, Antonio; Alfaro-Arias, Verónica; Cruz-Castillo, Carlos; Orozco-Solano, Allan

    2018-03-15

    VizGVar was designed to meet the growing need of the research community for improved genomic and proteomic data viewers that benefit from better information visualization. We implemented a new information architecture and applied user centered design principles to provide a new improved way of visualizing genetic information and protein data related to human disease. VizGVar connects the entire database of Ensembl protein motifs, domains, genes and exons with annotated SNPs and somatic variations from PharmGKB and COSMIC. VizGVar precisely represents genetic variations and their respective location by colored curves to designate different types of variations. The structured hierarchy of biological data is reflected in aggregated patterns through different levels, integrating several layers of information at once. VizGVar provides a new interactive, web-based JavaScript visualization of somatic mutations and protein variation, enabling fast and easy discovery of clinically relevant variation patterns. VizGVar is accessible at http://vizport.io/vizgvar; http://vizport.io/vizgvar/doc/. asolano@broadinstitute.org or allan.orozcosolano@ucr.ac.cr.

  11. Comparison of X-ray and gamma-ray dose-response curves for pink somatic mutations in Tradescantia clone 02

    International Nuclear Information System (INIS)

    Underbrink, A.G.; Kellerer, A.M.; Mills, R.E.; Sparrow, A.H.; Brookhaven National Lab., Upton, N.Y.

    1976-01-01

    Microdosimetric data indicate that the mean specific energy, xi, produced by individual charged particles from X rays and gamma rays is different for the two radiation qualities by nearly a factor of two. In order to test whether this influences the initial, linear component in the dose-effect relations, a comparison was made between dose-response curves for pink somatic mutations in Tradescantia clone 02 stamen hairs following X and gamma irradiations. Absorbed doses ranged from 2.66 to 300 rad. The results are in agreement with predictions made on the basis of microdosimetric data. At low doses gamma rays are substantially less effective than X rays. The RBE of gamma rays vs. X rays at low doses was approximately 0.6, a value lower than those usually reported in other experimental systems. (orig.) [de

  12. Tumor suppressor genes that escape from X-inactivation contribute to cancer sex bias

    OpenAIRE

    Dunford, Andrew; Weinstock, David M.; Savova, Virginia; Schumacher, Steven E.; Cleary, John P.; Yoda, Akinori; Sullivan, Timothy J.; Hess, Julian M.; Gimelbrant, Alexander A.; Beroukhim, Rameen; Lawrence, Michael S.; Getz, Gad; Lane, Andrew A.

    2016-01-01

    There is a striking and unexplained male predominance across many cancer types. A subset of X chromosome (chrX) genes can escape X-inactivation, which would protect females from complete functional loss by a single mutation. To identify putative “Escape from X-Inactivation Tumor Suppressor” (EXITS) genes, we compared somatic alterations from >4100 cancers across 21 tumor types for sex bias. Six of 783 non-pseudoautosomal region (PAR) chrX genes (ATRX, CNKSR2, DDX3X, KDM5C, KDM6A, and MAGEC3) ...

  13. TumorNext-Lynch-MMR: a comprehensive next generation sequencing assay for the detection of germline and somatic mutations in genes associated with mismatch repair deficiency and Lynch syndrome.

    Science.gov (United States)

    Gray, Phillip N; Tsai, Pei; Chen, Daniel; Wu, Sitao; Hoo, Jayne; Mu, Wenbo; Li, Bing; Vuong, Huy; Lu, Hsiao-Mei; Batth, Navanjot; Willett, Sara; Uyeda, Lisa; Shah, Swati; Gau, Chia-Ling; Umali, Monalyn; Espenschied, Carin; Janicek, Mike; Brown, Sandra; Margileth, David; Dobrea, Lavinia; Wagman, Lawrence; Rana, Huma; Hall, Michael J; Ross, Theodora; Terdiman, Jonathan; Cullinane, Carey; Ries, Savita; Totten, Ellen; Elliott, Aaron M

    2018-04-17

    The current algorithm for Lynch syndrome diagnosis is highly complex with multiple steps which can result in an extended time to diagnosis while depleting precious tumor specimens. Here we describe the analytical validation of a custom probe-based NGS tumor panel, TumorNext-Lynch-MMR, which generates a comprehensive genetic profile of both germline and somatic mutations that can accelerate and streamline the time to diagnosis and preserve specimen. TumorNext-Lynch-MMR can detect single nucleotide variants, small insertions and deletions in 39 genes that are frequently mutated in Lynch syndrome and colorectal cancer. Moreover, the panel provides microsatellite instability status and detects loss of heterozygosity in the five Lynch genes; MSH2 , MSH6 , MLH1 , PMS2 and EPCAM . Clinical cases are described that highlight the assays ability to differentiate between somatic and germline mutations, precisely classify variants and resolve discordant cases.

  14. Somatic mutations in mismatch repair genes in sporadic gastric carcinomas are not a cause but a consequence of the mutator phenotype

    NARCIS (Netherlands)

    Pinto, Mafalda; Wub, Ying; Mensink, Rob G. J.; Cirnes, Luis; Seruca, Raquel; Hofstra, Robert M. W.

    2008-01-01

    In hereditary nonpolyposis colorectal cancer (HNPCC), patients' mismatch repair (MMR) gene mutations cause MMR deficiency, leading to microsatellite instability (MSI-H). MSI-H is also found in a substantial fraction of sporadic gastric carcinomas (SGC), mainly due to MLH1 promoter hypermethylation,

  15. Synergistic effects of methyl methanesulfonate and X rays in inducing somatic mutations in the stamen hairs of Tradescantia clones, KU 27 and BNL 4430

    International Nuclear Information System (INIS)

    Ichikawa, Sadao; Yamaguchi, Akihiko; Okumura, Mikiko

    1993-01-01

    Young influorescences of Tradescantia clones KU 27 and BNL 4430, the both of which are blue/pink heterozygotes and have been demonstrated to be highly sensitive to alkylating agents, were exposed either to aqueous solutions of methyl methanesulfonate (MMS) for 16 hr alone (at 0.005 to 0.02% for KU 27 and at 0.005% for BNL 4430) or to acute 150 kVp X rays alone (161 to 531 mGy for Ku 27 and 501 to 976 mGy for BNL 4430), or in combinations (134 to 448 mGy for KU 27 and 458 to 865 mGy for BNL 4430 after the 0.005% MMS treatment). The induced somatic pink mutation frequencies per hair-cell division were studied and compared, and clone BNL 4430 was found to be nearly two times more sensitive to MMS than clone KU 27, while the X-ray-induced mutation frequencies in the latter was about 1.5 times higher than those in the former. The lower sensitivity to MMS of clone KU 27 (as compared with BNL 4430) was nevertheless about 5.6 times higher as compared with the responses of clone BNL 02 to MMS reported earlier, proving the high sensitivities of the two clones used in the present study. Clear synergistic effects of MMS and X rays were observed in the both clones, indicating that the mechanisms of inducing mutations are common at least in part between MMS and X rays. (author)

  16. Cadmium induces DNA damage in tobacco roots, but no DNA damage, somatic mutations or homologous recombination in tobacco leaves

    Czech Academy of Sciences Publication Activity Database

    Gichner, Tomáš; Patková, Zdeňka; Száková, J.; Demnerová, K.

    2004-01-01

    Roč. 559, 1/2 (2004), s. 49-57 ISSN 1383-5718 R&D Projects: GA ČR GA526/02/0293; GA ČR GA521/02/0400; GA MŠk LN00B030 Institutional research plan: CEZ:AV0Z5038910 Keywords : beta-Glucuronidase * Chlorophyll mutations * Comet assay Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.020, year: 2004

  17. Somatic mutations, allele loss, and DNA methylation of the Cub and Sushi Multiple Domains 1 (CSMD1 gene reveals association with early age of diagnosis in colorectal cancer patients.

    Directory of Open Access Journals (Sweden)

    Austin Y Shull

    Full Text Available The Cub and Sushi Multiple Domains 1 (CSMD1 gene, located on the short arm of chromosome 8, codes for a type I transmembrane protein whose function is currently unknown. CSMD1 expression is frequently lost in many epithelial cancers. Our goal was to characterize the relationships between CSMD1 somatic mutations, allele imbalance, DNA methylation, and the clinical characteristics in colorectal cancer patients.We sequenced the CSMD1 coding regions in 54 colorectal tumors using the 454FLX pyrosequencing platform to interrogate 72 amplicons covering the entire coding sequence. We used heterozygous SNP allele ratios at multiple CSMD1 loci to determine allelic balance and infer loss of heterozygosity. Finally, we performed methylation-specific PCR on 76 colorectal tumors to determine DNA methylation status for CSMD1 and known methylation targets ALX4, RUNX3, NEUROG1, and CDKN2A.Using 454FLX sequencing and confirming with Sanger sequencing, 16 CSMD1 somatic mutations were identified in 6 of the 54 colorectal tumors (11%. The nonsynonymous to synonymous mutation ratio of the 16 somatic mutations was 15:1, a ratio significantly higher than the expected 2:1 ratio (p = 0.014. This ratio indicates a presence of positive selection for mutations in the CSMD1 protein sequence. CSMD1 allelic imbalance was present in 19 of 37 informative cases (56%. Patients with allelic imbalance and CSMD1 mutations were significantly younger (average age, 41 years than those without somatic mutations (average age, 68 years. The majority of tumors were methylated at one or more CpG loci within the CSMD1 coding sequence, and CSMD1 methylation significantly correlated with two known methylation targets ALX4 and RUNX3. C:G>T:A substitutions were significantly overrepresented (47%, suggesting extensive cytosine methylation predisposing to somatic mutations.Deep amplicon sequencing and methylation-specific PCR reveal that CSMD1 alterations can correlate with earlier clinical

  18. Influence of radiation exposure rate on somatic mutation frequency and loss of reproductive integrity in tradescantia stamen hairs

    International Nuclear Information System (INIS)

    Ichikawa, S.; Nauman, C.H.; Sparrow, A.H.; Takahashi, C.S.

    1978-01-01

    Inflorescences of Tradescantia clone 02 (2n=12), hetero- or hemi-zygous for flower color, were exposed to a series of γ-ray exposures at two different exposure rates, 29.3 R/min and 0.026-0.52 R/min. Pink mutation-response curves, and survival curves based on reproductive integrity, were constructed for each of the exposure rates. Loss of reproductive integrity was also assessed at high (256 R/min) and low (0.52-4.17 R/min) γ-ray exposure rates in T. blossfeldiana (2n=72). All observations were made on stamen hairs. The higher exposure rate was 1.3-1.7 times more effective in inducing pink mutations in clone 02. A greater efficiency of the higher exposure rate was also found for both taxa at the loss of reproductive integrity endpoint. The D 0 values obtained at the higher exposure rates, 154 R for clone 02 and 720 R for T. blossfeldiana, were significantly lower than the corresponding values of 270 R and 1880 R obtained at the lower exposure rates. These D 0 's differ by factors of 1.75 and 2.61 for clone 02 and T. blossfeldiana, respectively. D 0 's for the two taxa were found to be inversely correlated with their interphase chromosome volumes. (Auth.)

  19. Transcriptome analysis of an apple (Malus × domestica) yellow fruit somatic mutation identifies a gene network module highly associated with anthocyanin and epigenetic regulation.

    Science.gov (United States)

    El-Sharkawy, Islam; Liang, Dong; Xu, Kenong

    2015-12-01

    Using RNA-seq, this study analysed an apple (Malus×domestica) anthocyanin-deficient yellow-skin somatic mutant 'Blondee' (BLO) and its red-skin parent 'Kidd's D-8' (KID), the original name of 'Gala', to understand the molecular mechanisms underlying the mutation. A total of 3299 differentially expressed genes (DEGs) were identified between BLO and KID at four developmental stages and/or between two adjacent stages within BLO and/or KID. A weighted gene co-expression network analysis (WGCNA) of the DEGs uncovered a network module of 34 genes highly correlated (r=0.95, P=9.0×10(-13)) with anthocyanin contents. Although 12 of the 34 genes in the WGCNA module were characterized and known of roles in anthocyanin, the remainder 22 appear to be novel. Examining the expression of ten representative genes in the module in 14 diverse apples revealed that at least eight were significantly correlated with anthocyanin variation. MdMYB10 (MDP0000259614) and MdGST (MDP0000252292) were among the most suppressed module member genes in BLO despite being undistinguishable in their corresponding sequences between BLO and KID. Methylation assay of MdMYB10 and MdGST in fruit skin revealed that two regions (MR3 and MR7) in the MdMYB10 promoter exhibited remarkable differences between BLO and KID. In particular, methylation was high and progressively increased alongside fruit development in BLO while was correspondingly low and constant in KID. The methylation levels in both MR3 and MR7 were negatively correlated with anthocyanin content as well as the expression of MdMYB10 and MdGST. Clearly, the collective repression of the 34 genes explains the loss-of-colour in BLO while the methylation in MdMYB10 promoter is likely causal for the mutation. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  20. Immunohistochemical null-phenotype for mismatch repair proteins in colonic carcinoma associated with concurrent MLH1 hypermethylation and MSH2 somatic mutations.

    Science.gov (United States)

    Wang, Tao; Stadler, Zsofia K; Zhang, Liying; Weiser, Martin R; Basturk, Olca; Hechtman, Jaclyn F; Vakiani, Efsevia; Saltz, Lenard B; Klimstra, David S; Shia, Jinru

    2018-04-01

    Microsatellite instability, a well-established driver pathway in colorectal carcinogenesis, can develop in both sporadic and hereditary conditions via different molecular alterations in the DNA mismatch repair (MMR) genes. MMR protein immunohistochemistry (IHC) is currently widely used for the detection of MMR deficiency in solid tumors. The IHC test, however, can show varied staining patterns, posing challenges in the interpretation of the staining results in some cases. Here we report a case of an 80-year-old female with a colonic adenocarcinoma that exhibited an unusual "null" IHC staining pattern with complete loss of all four MMR proteins (MLH1, MSH2, MSH6, and PMS2). This led to subsequent MLH1 methylation testing and next generation sequencing which demonstrated that the loss of all MMR proteins was associated with concurrent promoter hypermethylation of MLH1 and double somatic truncating mutations in MSH2. These molecular findings, in conjunction with the patient's age being 80 years and the fact that the patient had no personal or family cancer history, indicated that the MMR deficiency was highly likely sporadic in nature. Thus, the stringent Lynch syndrome type surveillance programs were not recommended to the patient and her family members. This case illustrates a rare but important scenario where a null IHC phenotype signifies complex underlying molecular alternations that bear clinical management implications, highlighting the need for recognition and awareness of such unusual IHC staining patterns.

  1. Analysis of the IgV(H) somatic mutations in splenic marginal zone lymphoma defines a group of unmutated cases with frequent 7q deletion and adverse clinical course.

    Science.gov (United States)

    Algara, Patricia; Mateo, Marisol S; Sanchez-Beato, Margarita; Mollejo, Manuela; Navas, Immaculada C; Romero, Lourdes; Solé, Francesc; Salido, Marta; Florensa, Lourdes; Martínez, Pedro; Campo, Elias; Piris, Miguel A

    2002-02-15

    This study aimed to correlate the frequency of somatic mutations in the IgV(H) gene and the use of specific segments in the V(H) repertoire with the clinical and characteristic features of a series of 35 cases of splenic marginal zone lymphoma (SMZL). The cases were studied by seminested polymerase chain reaction by using primers from the FR1 and J(H) region. The results showed unexpected molecular heterogeneity in this entity, with 49% unmutated cases (less than 2% somatic mutations). The 7q31 deletions and a shorter overall survival were more frequent in this group. Additionally a high percentage (18 of 40 sequences) of SMZL cases showed usage of the V(H)1-2 segment, thereby emphasizing the singularity of this neoplasia, suggesting that this tumor derives from a highly selected B-cell population and encouraging the search for specific antigens that are pathogenically relevant in the genesis or progression of this tumor.

  2. SubClonal Hierarchy Inference from Somatic Mutations: Automatic Reconstruction of Cancer Evolutionary Trees from Multi-region Next Generation Sequencing.

    Directory of Open Access Journals (Sweden)

    Noushin Niknafs

    2015-10-01

    Full Text Available Recent improvements in next-generation sequencing of tumor samples and the ability to identify somatic mutations at low allelic fractions have opened the way for new approaches to model the evolution of individual cancers. The power and utility of these models is increased when tumor samples from multiple sites are sequenced. Temporal ordering of the samples may provide insight into the etiology of both primary and metastatic lesions and rationalizations for tumor recurrence and therapeutic failures. Additional insights may be provided by temporal ordering of evolving subclones--cellular subpopulations with unique mutational profiles. Current methods for subclone hierarchy inference tightly couple the problem of temporal ordering with that of estimating the fraction of cancer cells harboring each mutation. We present a new framework that includes a rigorous statistical hypothesis test and a collection of tools that make it possible to decouple these problems, which we believe will enable substantial progress in the field of subclone hierarchy inference. The methods presented here can be flexibly combined with methods developed by others addressing either of these problems. We provide tools to interpret hypothesis test results, which inform phylogenetic tree construction, and we introduce the first genetic algorithm designed for this purpose. The utility of our framework is systematically demonstrated in simulations. For most tested combinations of tumor purity, sequencing coverage, and tree complexity, good power (≥ 0.8 can be achieved and Type 1 error is well controlled when at least three tumor samples are available from a patient. Using data from three published multi-region tumor sequencing studies of (murine small cell lung cancer, acute myeloid leukemia, and chronic lymphocytic leukemia, in which the authors reconstructed subclonal phylogenetic trees by manual expert curation, we show how different configurations of our tools can

  3. SubClonal Hierarchy Inference from Somatic Mutations: Automatic Reconstruction of Cancer Evolutionary Trees from Multi-region Next Generation Sequencing.

    Science.gov (United States)

    Niknafs, Noushin; Beleva-Guthrie, Violeta; Naiman, Daniel Q; Karchin, Rachel

    2015-10-01

    Recent improvements in next-generation sequencing of tumor samples and the ability to identify somatic mutations at low allelic fractions have opened the way for new approaches to model the evolution of individual cancers. The power and utility of these models is increased when tumor samples from multiple sites are sequenced. Temporal ordering of the samples may provide insight into the etiology of both primary and metastatic lesions and rationalizations for tumor recurrence and therapeutic failures. Additional insights may be provided by temporal ordering of evolving subclones--cellular subpopulations with unique mutational profiles. Current methods for subclone hierarchy inference tightly couple the problem of temporal ordering with that of estimating the fraction of cancer cells harboring each mutation. We present a new framework that includes a rigorous statistical hypothesis test and a collection of tools that make it possible to decouple these problems, which we believe will enable substantial progress in the field of subclone hierarchy inference. The methods presented here can be flexibly combined with methods developed by others addressing either of these problems. We provide tools to interpret hypothesis test results, which inform phylogenetic tree construction, and we introduce the first genetic algorithm designed for this purpose. The utility of our framework is systematically demonstrated in simulations. For most tested combinations of tumor purity, sequencing coverage, and tree complexity, good power (≥ 0.8) can be achieved and Type 1 error is well controlled when at least three tumor samples are available from a patient. Using data from three published multi-region tumor sequencing studies of (murine) small cell lung cancer, acute myeloid leukemia, and chronic lymphocytic leukemia, in which the authors reconstructed subclonal phylogenetic trees by manual expert curation, we show how different configurations of our tools can identify either a single

  4. Independent inactivation of arginine decarboxylase genes by nonsense and missense mutations led to pseudogene formation in Chlamydia trachomatis serovar L2 and D strains

    Directory of Open Access Journals (Sweden)

    Graham David E

    2009-07-01

    Full Text Available Abstract Background Chlamydia have reduced genomes that reflect their obligately parasitic lifestyle. Despite their different tissue tropisms, chlamydial strains share a large number of common genes and have few recognized pseudogenes, indicating genomic stability. All of the Chlamydiaceae have homologs of the aaxABC gene cluster that encodes a functional arginine:agmatine exchange system in Chlamydia (Chlamydophilapneumoniae. However, Chlamydia trachomatis serovar L2 strains have a nonsense mutation in their aaxB genes, and C. trachomatis serovar A and B strains have frameshift mutations in their aaxC homologs, suggesting that relaxed selection may have enabled the evolution of aax pseudogenes. Biochemical experiments were performed to determine whether the aaxABC genes from C. trachomatis strains were transcribed, and mutagenesis was used to identify nucleotide substitutions that prevent protein maturation and activity. Molecular evolution techniques were applied to determine the relaxation of selection and the scope of aax gene inactivation in the Chlamydiales. Results The aaxABC genes were co-transcribed in C. trachomatis L2/434, during the mid-late stage of cellular infection. However, a stop codon in the aaxB gene from this strain prevented the heterologous production of an active pyruvoyl-dependent arginine decarboxylase. Replacing that ochre codon with its ancestral tryptophan codon rescued the activity of this self-cleaving enzyme. The aaxB gene from C. trachomatis D/UW-3 was heterologously expressed as a proenzyme that failed to cleave and form the catalytic pyruvoyl cofactor. This inactive protein could be rescued by replacing the arginine-115 codon with an ancestral glycine codon. The aaxC gene from the D/UW-3 strain encoded an active arginine:agmatine antiporter protein, while the L2/434 homolog was unexpectedly inactive. Yet the frequencies of nonsynonymous versus synonymous nucleotide substitutions show no signs of relaxed

  5. A stochastic model of cell replicative senescence based on telomere shortening, oxidative stress, and somatic mutations in nuclear and mitochondrial DNA.

    Science.gov (United States)

    Sozou, P D; Kirkwood, T B

    2001-12-21

    Human diploid fibroblast cells can divide for only a limited number of times in vitro, a phenomenon known as replicative senescence or the Hayflick limit. Variability in doubling potential is observed within a clone of cells, and between two sister cells arising from a single mitotic division. This strongly suggests that the process by which cells become senescent is intrinsically stochastic. Among the various biochemical mechanisms that have been proposed to explain replicative senescence, particular interest has been focussed on the role of telomere reduction. In the absence of telomerase--an enzyme switched off in normal diploid fibro-blasts-cells lose telomeric DNA at each cell division. According to the telomere hypothesis of cell senescence, cells eventually reach a critically short telomere length and cell cycle arrest follows. In support of this concept, forced expression of telomerase in normal fibroblasts appears to prevent cell senescence. Nevertheless, the telomere hypothesis in its basic form has some difficulty in explaining the marked stochastic variations seen in the replicative lifespans of individual cells within a culture, and there is strong empirical and theoretical support for the concept that other kinds of damage may contribute to cellular ageing. We describe a stochastic network model of cell senescence in which a primary role is played by telomere reduction but in which other mechanisms (oxidative stress linked particularly to mitochondrial damage, and nuclear somatic mutations) also contribute. The model gives simulation results that are in good agreement with published data on intra-clonal variability in cell doubling potential and permits an analysis of how the various elements of the stochastic network interact. Such integrative models may aid in developing new experimental approaches aimed at unravelling the intrinsic complexity of the mechanisms contributing to human cell ageing. Copyright 2001 Academic Press.

  6. Mutations in the FHA-domain of ectopically expressed NBS1 lead to radiosensitization and to no increase in somatic mutation rates via a partial suppression of homologous recombination

    International Nuclear Information System (INIS)

    Ohara, Maki; Funyu, Yumi; Ebara, Shunsuke

    2014-01-01

    Ionizing radiation induces DNA double-strand breaks (DSBs). Mammalian cells repair DSBs through multiple pathways, and the repair pathway that is utilized may affect cellular radiation sensitivity. In this study, we examined effects on cellular radiosensitivity resulting from functional alterations in homologous recombination (HR). HR was inhibited by overexpression of the forkhead-associated (FHA) domain-mutated NBS1 (G27D/R28D: FHA-2D) protein in HeLa cells or in hamster cells carrying a human X-chromosome. Cells expressing FHA-2D presented partially (but significantly) HR-deficient phenotypes, which were assayed by the reduction of gene conversion frequencies measured with a reporter assay, a decrease in radiation-induced Mre11 foci formation, and hypersensitivity to camptothecin treatments. Interestingly, ectopic expression of FHA-2D did not increase the frequency of radiation-induced somatic mutations at the HPRT locus, suggesting that a partial reduction of HR efficiency has only a slight effect on genomic stability. The expression of FHA-2D rendered the exponentially growing cell population slightly (but significantly) more sensitive to ionizing radiation. This radiosensitization effect due to the expression of FHA-2D was enhanced when the cells were irradiated with split doses delivered at 24-h intervals. Furthermore, enhancement of radiation sensitivity by split dose irradiation was not seen in contact-inhibited G0/G1 populations, even though the cells expressed FHA-2D. These results suggest that the FHA domain of NBS1 might be an effective molecular target that can be used to induce radiosensitization using low molecular weight chemicals, and that partial inhibition of HR might improve the effectiveness of cancer radiotherapy. (author)

  7. The somatic FAH C.1061C>A change counteracts the frequent FAH c.1062+5G>A mutation and permits U1snRNA-based splicing correction.

    Science.gov (United States)

    Scalet, Daniela; Sacchetto, Claudia; Bernardi, Francesco; Pinotti, Mirko; van de Graaf, Stan F J; Balestra, Dario

    2018-05-01

    In tyrosinaemia type 1(HT1), a mosaic pattern of fumarylacetoacetase (FAH) immunopositive or immunonegative nodules in liver tissue has been reported in many patients. This aspect is generally explained by a spontaneous reversion of the mutation into a normal genotype. In one HT1 patient carrying the frequent FAH c.1062+5G>A mutation, a second somatic change (c.1061C>A) has been reported in the same allele, and found in immunopositive nodules. Here, we demonstrated that the c.1062+5G>A prevents usage of the exon 12 5' splice site (ss), even when forced by an engineered U1snRNA specifically designed on the FAH 5'ss to strengthen its recognition. Noticeably the new somatic c.1061C>A change, in linkage with the c.1062+5G>A mutation, partially rescues the defective 5'ss and is associated to trace level (~5%) of correct transcripts. Interestingly, this combined genetic condition strongly favored the rescue by the engineered U1snRNA, with correct transcripts reaching up to 60%. Altogether, these findings elucidate the molecular basis of HT1 caused by the frequent FAH c.1062+5G>A mutation, and demonstrate the compensatory effect of the c.1061C>A change in promoting exon definition, thus unraveling a rare mechanism leading to FAH immune-reactive mosaicism.

  8. Antibiotic resistance in Pseudomonas aeruginosa strains with increased mutation frequency due to inactivation of the DNA oxidative repair system

    DEFF Research Database (Denmark)

    Mandsberg, Lotte F; Ciofu, Oana; Kirkby, N

    2009-01-01

    ,8-dihydro-8-oxodeoxyguanosine) than PAO1 after exposure to PMNs, and they developed resistance to antibiotics more frequently. The mechanisms of resistance were increased β-lactamase production and overexpression of the MexCD-OprJ efflux-pump. Mutations in either the mutT or the mutY gene were found...... in resistant HP clinical isolates from patients with CF, and complementation with wild-type genes reverted the phenotype. In conclusion, oxidative stress might be involved in the development of resistance to antibiotics. We therefore suggest the possible use of antioxidants for CF patients to prevent...

  9. Analysis of IgV gene mutations in B cell chronic lymphocytic leukaemia according to antigen-driven selection identifies subgroups with different prognosis and usage of the canonical somatic hypermutation machinery.

    Science.gov (United States)

    Degan, Massimo; Bomben, Riccardo; Bo, Michele Dal; Zucchetto, Antonella; Nanni, Paola; Rupolo, Maurizio; Steffan, Agostino; Attadia, Vincenza; Ballerini, Pier Ferruccio; Damiani, Daniela; Pucillo, Carlo; Poeta, Giovanni Del; Colombatti, Alfonso; Gattei, Valter

    2004-07-01

    Cases of B-cell chronic lymphocytic leukaemia (B-CLL) with mutated (M) IgV(H) genes have a better prognosis than unmutated (UM) cases. We analysed the IgV(H) mutational status of B-CLL according to the features of a canonical somatic hypermutation (SHM) process, correlating this data with survival. In a series of 141 B-CLLs, 124 cases were examined for IgV(H) gene per cent mutations and skewing of replacement/silent mutations in the framework/complementarity-determining regions as evidence of antigen-driven selection; this identified three B-CLL subsets: significantly mutated (sM), with evidence of antigen-driven selection, not significantly mutated (nsM) and UM, without such evidence and IgV(H) gene per cent mutations above or below the 2% cut-off. sM B-CLL patients had longer survival within the good prognosis subgroup that had more than 2% mutations of IgV(H) genes. sM, nsM and UM B-CLL were also characterized for the biased usage of IgV(H) families, intraclonal IgV(H) gene diversification, preference of mutations to target-specific nucleotides or hotspots, and for the expression of enzymes involved in SHM (translesion DNA polymerase zeta and eta and activation-induced cytidine deaminase). These findings indicate the activation of a canonical SHM process in nsM and sM B-CLLs and underscore the role of the antigen in defining the specific clinical and biological features of B-CLL.

  10. Cellular and subcellular effect of heavy ions: A comparison of the induction of strand breaks and chromosomal aberration with the incidence of inactivation and mutation

    International Nuclear Information System (INIS)

    Kraft, G.; Kraft-Weyrather, W.; Ritter, S.; Scholz, M.; Stanton, J.

    1988-10-01

    Radiobiological effects of heavy charged particles are compared for a large variety of ions from Helium to Uranium and energies between 1 and 1000 MeV/u which correspond to LET values between 10 and 16000 keV/μm. The different cross section for the induction of strand breaks and chromosomal aberrations as well as for inactivation and mutation induction exhibit striking similarities when compared as function of the linear energy transfer (LET). At LET values below 100 keV/μm all data points of one specific effect form one single curve as a function of LET, independent of the atomic number of the ion. In this LET range, the biological effects are independent from the particle energy or track structure and depend only on the energy transfer. Therefore, LET is a good parameter in tis regime. For LET values greater than 100 keV/μm, the curves for the different ions separate from the common curve in order of increasing atomic numbers. In this regime LET is no longer a good parameter and the physical parameters of the formation of particle tracks are important. The similarity of the σ-LET curves for different endpoints indicates that the 'hook-structure' is produced by physical and chemical effects which occur before the biologically relevant lesions are formed. However, from the existing data of biological effects, it can be concluded that the efficiencies for cell killing are always smaller than those extrapolated from X-ray data on the basis of the energy deposition only. Therefore, cells which are directly hit by an HZE particle are not killed and undergo a finite risk of mutation and transformation. (orig.)

  11. Somatic mosaicism caused by monoallelic reversion of a mutation in T cells of a patient with ADA-SCID and the effects of enzyme replacement therapy on the revertant phenotype.

    Science.gov (United States)

    Moncada-Vélez, M; Vélez-Ortega, A; Orrego, J; Santisteban, I; Jagadeesh, J; Olivares, M; Olaya, N; Hershfield, M; Candotti, F; Franco, J

    2011-11-01

    Patients with adenosine deaminase (ADA) deficiency exhibit spontaneous and partial clinical remission associated with somatic reversion of inherited mutations. We report a child with severe combined immunodeficiency (T-B- SCID) due to ADA deficiency diagnosed at the age of 1 month, whose lymphocyte counts including CD4+ and CD8+ T and NK cells began to improve after several months with normalization of ADA activity in Peripheral blood lymphocytes (PBL), as a result of somatic mosaicism caused by monoallelic reversion of the causative mutation in the ADA gene. He was not eligible for haematopoietic stem cell transplantation (HSCT) or gene therapy (GT); therefore he was placed on enzyme replacement therapy (ERT) with bovine PEG-ADA. The follow-up of metabolic and immunologic responses to ERT included gradual improvement in ADA activity in erythrocytes and transient expansion of most lymphocyte subsets, followed by gradual stabilization of CD4+ and CD8+ T (with naïve phenotype) and NK cells, and sustained expansion of TCRγδ+ T cells. This was accompanied by the disappearance of the revertant T cells as shown by DNA sequencing from PBL. Although the patient's clinical condition improved marginally, he later developed a germinal cell tumour and eventually died at the age of 67 months from sepsis. This case adds to our current knowledge of spontaneous reversion of mutations in ADA deficiency and shows that the effects of the ERT may vary among these patients, suggesting that it could depend on the cell and type in which the somatic mosaicism is established upon reversion. © 2011 The Authors. Scandinavian Journal of Immunology © 2011 Blackwell Publishing Ltd.

  12. Somatic mutations of isocitrate dehydrogenases 1 and 2 are prognostic and follow-up markers in patients with acute myeloid leukaemia with normal karyotype

    Directory of Open Access Journals (Sweden)

    Virijevic Marijana

    2016-12-01

    Full Text Available Mutations in the isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2 genes are frequent molecular lesions in acute myeloid leukaemia with normal karyotype (AML-NK. The effects of IDH mutations on clinical features and treatment outcome in AML-NK have been widely investigated, but only a few studies monitored these mutations during follow-up.

  13. The Number of Point Mutations in Induced Pluripotent Stem Cells and Nuclear Transfer Embryonic Stem Cells Depends on the Method and Somatic Cell Type Used for Their Generation.

    Science.gov (United States)

    Araki, Ryoko; Mizutani, Eiji; Hoki, Yuko; Sunayama, Misato; Wakayama, Sayaka; Nagatomo, Hiroaki; Kasama, Yasuji; Nakamura, Miki; Wakayama, Teruhiko; Abe, Masumi

    2017-05-01

    Induced pluripotent stem cells hold great promise for regenerative medicine but point mutations have been identified in these cells and have raised serious concerns about their safe use. We generated nuclear transfer embryonic stem cells (ntESCs) from both mouse embryonic fibroblasts (MEFs) and tail-tip fibroblasts (TTFs) and by whole genome sequencing found fewer mutations compared with iPSCs generated by retroviral gene transduction. Furthermore, TTF-derived ntESCs showed only a very small number of point mutations, approximately 80% less than the number observed in iPSCs generated using retrovirus. Base substitution profile analysis confirmed this greatly reduced number of point mutations. The point mutations in iPSCs are therefore not a Yamanaka factor-specific phenomenon but are intrinsic to genome reprogramming. Moreover, the dramatic reduction in point mutations in ntESCs suggests that most are not essential for genome reprogramming. Our results suggest that it is feasible to reduce the point mutation frequency in iPSCs by optimizing various genome reprogramming conditions. We conducted whole genome sequencing of ntES cells derived from MEFs or TTFs. We thereby succeeded in establishing TTF-derived ntES cell lines with far fewer point mutations. Base substitution profile analysis of these clones also indicated a reduced point mutation frequency, moving from a transversion-predominance to a transition-predominance. Stem Cells 2017;35:1189-1196. © 2017 AlphaMed Press.

  14. Spectrum of somatic mutations detected by targeted next-generation sequencing and their prognostic significance in adult patients with acute lymphoblastic leukemia

    Directory of Open Access Journals (Sweden)

    Juan Feng

    2017-02-01

    Full Text Available Abstract Target-specific next-generation sequencing technology was used to analyze 112 genes in adult patients with acute lymphoblastic leukemia (ALL. This sequencing mainly focused on the specific mutational hotspots. Among the 121 patients, 93 patients were B-ALL (76.9%, and 28 patients (23.1% were T-ALL. Of the 121 patients, 110 (90.9% harbored at least one mutation. The five most frequently mutated genes in T-ALL are NOTCH1, JAK3, FBXW7, FAT1, and NRAS. In B-ALL, FAT1, SF1, CRLF2, TET2, and PTPN1 have higher incidence of mutations. Gene mutations are different between Ph+ALL and Ph−ALL patients. B-ALL patients with PTPN11 mutation and T-ALL patients with NOTCH1 and/or FBXW7 mutations showed better survival. But B-ALL with JAK1/JAK2 mutations showed worse survival. The results suggest that gene mutations exist in adult ALL patients universally, they are related with prognosis.

  15. Inactivation of the DNA repair gene O6-methylguanine-DNA methyltransferase by promoter hypermethylation is associated with G to A mutations in K-ras in colorectal tumorigenesis.

    Science.gov (United States)

    Esteller, M; Toyota, M; Sanchez-Cespedes, M; Capella, G; Peinado, M A; Watkins, D N; Issa, J P; Sidransky, D; Baylin, S B; Herman, J G

    2000-05-01

    O6-methylguanine DNA methyltransferase (MGMT) is a DNA repair protein that removes mutagenic and cytotoxic adducts from the O6 position of guanine. O6-methylguanine mispairs with thymine during replication, and if the adduct is not removed, this results in conversion from a guanine-cytosine pair to an adenine-thymine pair. In vitro assays show that MGMT expression avoids G to A mutations and MGMT transgenic mice are protected against G to A transitions at ras genes. We have recently demonstrated that the MGMT gene is silenced by promoter methylation in many human tumors, including colorectal carcinomas. To study the relevance of defective MGMT function by aberrant methylation in relation to the presence of K-ras mutations, we studied 244 colorectal tumor samples for MGMT promoter hypermethylation and K-ras mutational status. Our results show a clear association between the inactivation of MGMT by promoter hypermethylation and the appearance of G to A mutations at K-ras: 71% (36 of 51) of the tumors displaying this particular type of mutation had abnormal MGMT methylation, whereas only 32% (12 of 37) of those with other K-ras mutations not involving G to A transitions and 35% (55 of 156) of the tumors without K-ras mutations demonstrated MGMT methylation (P = 0.002). In addition, MGMT loss associated with hypermethylation was observed in the small adenomas, including those that do not yet contain K-ras mutations. Hypermethylation of other genes such as p16INK4a and p14ARF was not associated with either MGMT hypermethylation or K-ras mutation. Our data suggest that epigenetic silencing of MGMT by promoter hypermethylation may lead to a particular genetic change in human cancer, specifically G to A transitions in the K-ras oncogene.

  16. Ras mutations are rare in solitary cold and toxic thyroid nodules.

    Science.gov (United States)

    Krohn, K; Reske, A; Ackermann, F; Müller, A; Paschke, R

    2001-08-01

    Activation of ras proto-oncogenes as a result of point mutations is detectable in a significant percentage of most types of tumour. Similar to neoplasms of other organs, mutations of all three ras genes can be found in thyroid tumours. H-, K- and N-ras mutations have been detected in up to 20% of follicular adenomas and adenomatous nodules which were not functionally characterized. This raises the question as to whether ras mutations are specific for hypofunctional nodules and TSH receptor mutations for hyperfunctioning nodules. To investigate ras and TSH receptor mutations with respect to functional differentiation we studied 41 scintigraphically cold nodules and 47 toxic thyroid nodules. To address the likelihood of a somatic mutation we also studied the clonal origin of these tumours. Genomic DNA was extracted from nodular and surrounding tissue. Mutational hot spots in exons 1 and 2 of the H- and K-ras gene were PCR amplified and sequenced using big dye terminator chemistry. Denaturing gradient gel electrophoresis (DGGE) was used to verify sequencing results for the H-ras gene and to analyse the N-ras gene because its greater sensitivity in detecting somatic mutations. Clonality of nodular thyroid tissue was evaluated using X-Chromosome inactivation based on PCR amplification of the human androgen receptor locus. Monoclonal origin was detectable in 14 of 23 informative samples from cold thyroid nodules. In toxic thyroid nodules the frequency of clonal tissue was 20 in 30 informative cases. Only one point mutation could be found in the N-ras gene codon 61 (Gly to Arg) in a cold adenomatous nodule which was monoclonal. In toxic thyroid nodules no ras mutation was detectable. Our study suggests that ras mutations are rare in solitary cold and toxic thyroid nodules and that the frequent monoclonal origin of these tumours implies somatic mutations in genes other than H-, K- and N-ras.

  17. Tumor suppressor genes that escape from X-inactivation contribute to cancer sex bias

    Science.gov (United States)

    Dunford, Andrew; Weinstock, David M.; Savova, Virginia; Schumacher, Steven E.; Cleary, John P.; Yoda, Akinori; Sullivan, Timothy J.; Hess, Julian M.; Gimelbrant, Alexander A.; Beroukhim, Rameen; Lawrence, Michael S.; Getz, Gad; Lane, Andrew A.

    2016-01-01

    There is a striking and unexplained male predominance across many cancer types. A subset of X chromosome (chrX) genes can escape X-inactivation, which would protect females from complete functional loss by a single mutation. To identify putative “Escape from X-Inactivation Tumor Suppressor” (EXITS) genes, we compared somatic alterations from >4100 cancers across 21 tumor types for sex bias. Six of 783 non-pseudoautosomal region (PAR) chrX genes (ATRX, CNKSR2, DDX3X, KDM5C, KDM6A, and MAGEC3) more frequently harbored loss-of-function mutations in males (based on false discovery rate <0.1), compared to zero of 18,055 autosomal and PAR genes (P<0.0001). Male-biased mutations in genes that escape X-inactivation were observed in combined analysis across many cancers and in several individual tumor types, suggesting a generalized phenomenon. We conclude that biallelic expression of EXITS genes in females explains a portion of the reduced cancer incidence compared to males across a variety of tumor types. PMID:27869828

  18. Tumor-suppressor genes that escape from X-inactivation contribute to cancer sex bias.

    Science.gov (United States)

    Dunford, Andrew; Weinstock, David M; Savova, Virginia; Schumacher, Steven E; Cleary, John P; Yoda, Akinori; Sullivan, Timothy J; Hess, Julian M; Gimelbrant, Alexander A; Beroukhim, Rameen; Lawrence, Michael S; Getz, Gad; Lane, Andrew A

    2017-01-01

    There is a striking and unexplained male predominance across many cancer types. A subset of X-chromosome genes can escape X-inactivation, which would protect females from complete functional loss by a single mutation. To identify putative 'escape from X-inactivation tumor-suppressor' (EXITS) genes, we examined somatic alterations from >4,100 cancers across 21 tumor types for sex bias. Six of 783 non-pseudoautosomal region (PAR) X-chromosome genes (ATRX, CNKSR2, DDX3X, KDM5C, KDM6A, and MAGEC3) harbored loss-of-function mutations more frequently in males (based on a false discovery rate < 0.1), in comparison to zero of 18,055 autosomal and PAR genes (Fisher's exact P < 0.0001). Male-biased mutations in genes that escape X-inactivation were observed in combined analysis across many cancers and in several individual tumor types, suggesting a generalized phenomenon. We conclude that biallelic expression of EXITS genes in females explains a portion of the reduced cancer incidence in females as compared to males across a variety of tumor types.

  19. Mutation and Methylation Analysis of the Chromodomain-Helicase-DNA Binding 5 Gene in Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Kylie L. Gorringe

    2008-11-01

    Full Text Available Chromodomain, helicase, DNA binding 5 (CHD5 is a member of a subclass of the chromatin remodeling Swi/Snf proteins and has recently been proposed as a tumor suppressor in a diverse range of human cancers. We analyzed all 41 coding exons of CHD5 for somatic mutations in 123 primary ovarian cancers as well as 60 primary breast cancers using high-resolution melt analysis. We also examined methylation of the CHD5 promoter in 48 ovarian cancer samples by methylation-specific single-stranded conformation polymorphism and bisulfite sequencing. In contrast to previous studies, no mutations were identified in the breast cancers, but somatic heterozygous missense mutations were identified in 3 of 123 ovarian cancers. We identified promoter methylation in 3 of 45 samples with normal CHD5 and in 2 of 3 samples with CHD5 mutation, suggesting these tumors may have biallelic inactivation of CHD5. Hemizygous copy number loss at CHD5 occurred in 6 of 85 samples as assessed by single nucleotide polymorphism array. Tumors with CHD5 mutation or methylation were more likely to have mutation of KRAS or BRAF (P = .04. The aggregate frequency of CHD5 haploinsufficiency or inactivation is 16.2% in ovarian cancer. Thus, CHD5 may play a role as a tumor suppressor gene in ovarian cancer; however, it is likely that there is another target of the frequent copy number neutral loss of heterozygosity observed at 1p36.

  20. Comparative effects of ionizing radiation and two gaseous chemical mutagens on somatic mutation induction in one mutable and two non-mutable clones of Tradescantia

    International Nuclear Information System (INIS)

    Nauman, C.H.; Sparrow, A.H.; Schairer, L.A.

    1976-01-01

    The X-ray dose responses of mutable clone 0106 of Tradescantia (mutable for blue to pink), and its parent clone 02 have been determined for pink and colorless mutations in stamen hair cells, and are compared to the previously determined X-ray response for pink mutations of a third unrelated clone, clone 4430 (hybrid of T. subacaulis and T. hirsutiflora). X-ray response curves are compared to the response curves of the same three clones after exposure to the gaseous phase of the alkylating agent ethyl methanesulfate (EMS) and the fumigant and gasoline additive 1,2-dibromoethane (DBE). X-irradiation induces a pink mutation rate in mutable clone 0106 that is significantly higher than that of the nearly identical pink mutation rates in clones 02 and 4430. However, the colorless mutation rates of clones 02 and 0106 are not significantly different from one another. In clones 02 and 0106, pink mutations occur more frequently than colorless mutations at lower doses, but colorless dose-response curves saturate at higher doses than do those for pink mutations. Exposure-response curves for EMS and DBE have characteristics similar to those of X-ray response curves: exponential rise followed by an area of saturation. However, it was found that the relative sensitivities of the three clones to the gaseous mutagens and to ionizing radiation do not parallel one another. Where clones 02 and 4430 are equally sensitive to X-rays, at equal mutagen concentration clone 4430 is 6-7 times more sensitive to EMS and 7-9 times more sensitive to DBE than is clone 02. Mutable clone 0106 shows intermediate sensitivities to both EMS and DBE

  1. Detection of EGFR somatic mutations in non-small cell lung cancer (NSCLC) using a novel mutant-enriched liquidchip (MEL) technology.

    Science.gov (United States)

    Zhang, Li; Yang, Huiyi; Zhao, Yanwei; Liu, Wenchao; Wu, Shiyang; He, Jiaying; Luo, Xiaodi; Zhu, Zeyao; Xu, Jiasen; Zhou, Qinghua; Ren-Heidenreich, Lifen

    2012-09-01

    We have developed and standardized a novel technology, mutant-enriched liquidchip (MEL), for clinical detection of EGFR mutations. The MEL integrates a mutant-enriched PCR procedure with liquidchip technology for detections of EGFR exon 19 deletions and L858R mutation on both formalin-fixed and paraffin-embedded (FFPE) slides and plasma samples from patients with non-small cell lung cancer (NSCLC). The detection sensitivity was 0.1% of mutant DNA in the presence of its wild-type DNA. The cross-reaction rate was lower than 5%. To evaluate the MEL platform, the EGFR mutation status of 59 patients with advanced NSCLC treated with EGFRTKIs (Tyrosine Kinase Inhibitors) were tested on their FFPE samples. EGFR exon 19 deletions and L858R were detected in 21 patients (21/59) and 76.2% (16/21) of them had partial response to the EGFR-TKIs, while by sequencing method, only 4 (4/59) mutations were detected. Plasma samples from 627 patients with various stages of NSCLC were examined with the MEL and 22% of EGFR exon 19 deletions and L858R were detected. Furthermore, in patients with advanced disease there are more mutations detected in plasma samples than in patients with less advanced disease. In conclusion, the MEL is a sensitive, stable, and robust technology for detecting EGFR DNA mutations from both FFPE and plasma samples from patients with NSCLC and is now routinely used for clinical diagnosis.

  2. Somatic symptom disorder

    Science.gov (United States)

    ... related disorders; Somatization disorder; Somatiform disorders; Briquet syndrome; Illness anxiety disorder References American Psychiatric Association. Somatic symptom disorder. Diagnostic and Statistical Manual of Mental Disorders . ...

  3. Improved somatic mutagenesis in zebrafish using transcription activator-like effector nucleases (TALENs.

    Directory of Open Access Journals (Sweden)

    Finola E Moore

    Full Text Available Zinc Finger Nucleases (ZFNs made by Context-Dependent Assembly (CoDA and Transcription Activator-Like Effector Nucleases (TALENs provide robust and user-friendly technologies for efficiently inactivating genes in zebrafish. These designer nucleases bind to and cleave DNA at particular target sites, inducing error-prone repair that can result in insertion or deletion mutations. Here, we assess the relative efficiencies of these technologies for inducing somatic DNA mutations in mosaic zebrafish. We find that TALENs exhibited a higher success rate for obtaining active nucleases capable of inducing mutations than compared with CoDA ZFNs. For example, all six TALENs tested induced DNA mutations at genomic target sites while only a subset of CoDA ZFNs exhibited detectable rates of mutagenesis. TALENs also exhibited higher mutation rates than CoDA ZFNs that had not been pre-screened using a bacterial two-hybrid assay, with DNA mutation rates ranging from 20%-76.8% compared to 1.1%-3.3%. Furthermore, the broader targeting range of TALENs enabled us to induce mutations at the methionine translation start site, sequences that were not targetable using the CoDA ZFN platform. TALENs exhibited similar toxicity to CoDA ZFNs, with >50% of injected animals surviving to 3 days of life. Taken together, our results suggest that TALEN technology provides a robust alternative to CoDA ZFNs for inducing targeted gene-inactivation in zebrafish, making it a preferred technology for creating targeted knockout mutants in zebrafish.

  4. MO-DE-207B-01: JACK FOWLER JUNIOR INVESTIGATOR COMPETITION WINNER: Between Somatic Mutations and PET-Based Radiomic Features in Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yip, S; Coroller, T; Rios Velazquez, E; Parmar, C; Mak, R; Aerts, H [Brigham and Women’s Hospital, Dana Farber Cancer Institute, and Harvard Medical School, Boston, MA (United States); Kim, J [Brigham and Women’s Hospital, Boston Children’s Hospital and Harvard Medical School, Boston, MA (United States)

    2016-06-15

    Purpose: Although PET-based radiomic features have been proposed to quantify tumor heterogeneity and shown promise in outcome prediction, little is known about their relationship with tumor genetics. This study assessed the association of [{sup 18}F]fluorodeoxyglucose (FDG)-PET-based radiomic features with non-small cell lung cancer (NSCLC) mutations. Methods: 348 NSCLC patients underwent FDG-PET/CT scans before treatment and were tested for genetic mutations. 13% (44/348) and 28% (96/348) patients were found to harbor EGFR (EGFR+) and KRAS (KRAS+) mutations, respectively. We evaluated nineteen PET-based radiomic features quantifying phenotypic traits, and compared them with conventional PET features (metabolic tumor volume (MTV) and maximum-SUV). The association between the feature values and mutation status was evaluated using the Wilcoxcon-rank-sum-test. The ability of each measure to predict mutations was assessed by the area under the receiver operating curve (AUC). Noether’s test was used to determine if the AUCs were significantly from random (AUC=0.50). All p-values were corrected for multiple testing by controlling the false discovery rate (FDR{sub Wilcoxon} and FDR{sub Noether}) of 10%. Results: Eight radiomic features, MTV, and maximum-SUV, were significantly associated with the EGFR mutation (FDR{sub Wilcoxon}=0.01–0.10). However, KRAS+ demonstrated no significantly distinctive imaging features compared to KRAS− (FDR{sub Wilcoxon}≥0.92). EGFR+ and EGFR− were significantly discriminated by conventional PET features (AUC=0.61, FDR{sub Noether}=0.04 for MTV and AUC=0.64, FDR{sub Noether}=0.01 for maximum-SUV). Eight radiomic features were significantly predictive for EGFR+ compared to EGFR− (AUC=0.59–0.67, FDR{sub Noether}=0.0032–0.09). Normalized-inverse-difference-moment outperformed all features in predicting EGFR mutation (AUC=0.67, FDR{sub Noether}=0.0032). Moreover, only the radiomic feature normalized-inverse-difference-moment could

  5. Signatures of mutational processes in human cancer

    NARCIS (Netherlands)

    Alexandrov, L.B.; Nik-Zainal, S.; Wedge, D.C.; Aparicio, S.A.; Behjati, S.; Biankin, A.V.; Bignell, G.R.; Bolli, N.; Borg, A.; Borresen-Dale, A.L.; Boyault, S.; Burkhardt, B.; Butler, A.P.; Caldas, C.; Davies, H.R.; Desmedt, C.; Eils, R.; Eyfjord, J.E.; Foekens, J.A.; Greaves, M.; Hosoda, F.; Hutter, B.; Ilicic, T.; Imbeaud, S.; Imielinsk, M.; Jager, N.; Jones, D.T.; Knappskog, S.; Kool, M.; Lakhani, S.R.; Lopez-Otin, C.; Martin, S.; Munshi, N.C.; Nakamura, H.; Northcott, P.A.; Pajic, M.; Papaemmanuil, E.; Paradiso, A.; Pearson, J.V.; Puente, X.S.; Raine, K.; Ramakrishna, M.; Richardson, A.L.; Richter, J.; Rosenstiel, P.; Schlesner, M.; Schumacher, T.N.; Span, P.N.; Teague, J.W.; Totoki, Y.; Tutt, A.N.; Valdes-Mas, R.; Buuren, M.M. van; Veer, L. van 't; Vincent-Salomon, A.; Waddell, N.; Yates, L.R.; Zucman-Rossi, J.; Futreal, P.A.; McDermott, U.; Lichter, P.; Meyerson, M.; Grimmond, S.M.; Siebert, R.; Campo, E.; Shibata, T.; Pfister, S.M.; Campbell, P.J.; Stratton, M.R.; Schlooz-Vries, M.S.; Tol, J.J. van; Laarhoven, H.W. van; Sweep, F.C.; Bult, P.; et al.,

    2013-01-01

    All cancers are caused by somatic mutations; however, understanding of the biological processes generating these mutations is limited. The catalogue of somatic mutations from a cancer genome bears the signatures of the mutational processes that have been operative. Here we analysed 4,938,362

  6. Downregulation but lack of promoter hypermethylation or somatic mutations of the potential tumor suppressor CXXC5 in MDS and AML with deletion 5q

    DEFF Research Database (Denmark)

    Treppendahl, Marianne Bach; Möllgård, L; Hellström-Lindberg, E

    2013-01-01

    During recent years mutations in epigenetic modulators have been identified in several human cancers, including acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS)[1]. CXXC5 has been found to be necessary for retinoic acid induced differentiation of myelocytic leukemia cells, identify......During recent years mutations in epigenetic modulators have been identified in several human cancers, including acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS)[1]. CXXC5 has been found to be necessary for retinoic acid induced differentiation of myelocytic leukemia cells...

  7. Unusual late presentation of X-linked chronic granulomatous disease in an adult female with a somatic mosaic for a novel mutation in CYBB

    NARCIS (Netherlands)

    Wolach, Baruch; Scharf, Yitshak; Gavrieli, Ronit; de Boer, Martin; Roos, Dirk

    2005-01-01

    Most patients with chronic granulomatous disease (CGD) have mutations in the X-linked CYBB gene that encodes gp91(phox), a component of the phagocyte NADPH oxidase. The resulting X-linked form of CGD is usually manifested in boys. Rarely, X-CGD is encountered in female carriers with extreme

  8. Parental somatic and germ-line mosaicism for a FBN2 mutation and analysis of FBN2 transcript levels in dermal fibroblasts

    NARCIS (Netherlands)

    Putnam, E. A.; Park, E. S.; Aalfs, C. M.; Hennekam, R. C.; Milewicz, D. M.

    1997-01-01

    Congenital contractural arachnodactyly (CCA) is an autosomal dominant disorder that is phenotypically related to the Marfan syndrome. CCA has recently been shown to result from mutations in the FBN2 gene, which encodes an elastin-associated microfibrillar protein called fibrillin-2. Two siblings are

  9. The WHIM-like CXCR4(S338X) somatic mutation activates AKT and ERK, and promotes resistance to ibrutinib and other agents used in the treatment of Waldenstrom's Macroglobulinemia.

    Science.gov (United States)

    Cao, Y; Hunter, Z R; Liu, X; Xu, L; Yang, G; Chen, J; Patterson, C J; Tsakmaklis, N; Kanan, S; Rodig, S; Castillo, J J; Treon, S P

    2015-01-01

    CXCR4(WHIM) somatic mutations are common Waldenstrom's Macroglobulinemia (WM), and are associated with clinical resistance to ibrutinib. We engineered WM cells to express the most common WHIM (Warts, Hypogammaglobulinemia, Infections and Myelokathexis), CXCR(S338X) mutation in WM. Following SDF-1a stimulation, CXCR4(S338X) WM cells exhibited decreased receptor internalization, enhanced and sustained AKT kinase (AKT) and extracellular regulated kinase (ERK) signaling, decreased poly (ADP-ribose) polymerase and caspase 3 cleavage, and decreased Annexin V staining versus CXCR4 wild-type (WT) cells. CXCR4(S338X)-related signaling and survival effects were blocked by the CXCR4 inhibitor AMD3100. SDF-1a-treated CXCR4(S338X) WM cells showed sustained AKT and ERK activation and decreased apoptotic changes versus CXCR4(WT) cells following ibrutinib treatment, findings which were also reversed by AMD3100. AKT or ERK antagonists restored ibrutinib-triggered apoptotic changes in SDF-1a-treated CXCR4(S338X) WM cells demonstrating their role in SDF-1a-mediated ibrutinib resistance. Enhanced bone marrow pAKT staining was also evident in CXCR4(WHIM) versus CXCR4(WT) WM patients, and remained active despite ibrutinib therapy in CXCR4(WHIM) patients. Last, CXCR4(S338X) WM cells showed varying levels of resistance to other WM relevant therapeutics, including bendamustine, fludarabine, bortezomib and idelalisib in the presence of SDF-1a. These studies demonstrate a functional role for CXCR4(WHIM) mutations, and provide a framework for investigation of CXCR4 inhibitors in WM.

  10. The relationship of different somatic mutations induced by neutrons and X rays to loss of reproductive integrity in Tradescantia stamen hairs

    International Nuclear Information System (INIS)

    Underbrink, A.G.; Huczkowski, J.; Woch, B.; Gedlek, E.; Cebulska-Wasilewska, A.; Litwiniszyn, M.; Kasper, E.

    1978-01-01

    It was found that the survival curves derived from X-irradiations and neutrons of two energies are characteristic for those usually found in many other systems. It was also found that the loss of reproductive integrity and two visible cell-type aberrations or mutations follow a 1:1 ratio until higher doses are reached after neutron irradiation. This is also true for X rays, except that lethality was not observed at relatively low doses. The mutant event spectrum was found to change after a certain level of lethality was reached. It was also found that the spectra of mutations in relation to survival may be changed not only by dose but also by radiation quality. (author)

  11. Not All Next Generation Sequencing Diagnostics are Created Equal: Understanding the Nuances of Solid Tumor Assay Design for Somatic Mutation Detection

    Energy Technology Data Exchange (ETDEWEB)

    Gray, Phillip N., E-mail: pgray@ambrygen.com; Dunlop, Charles L.M.; Elliott, Aaron M. [Ambry Genetics, 15 Argonaut, Aliso Viejo, CA 92656 (United States)

    2015-07-17

    The molecular characterization of tumors using next generation sequencing (NGS) is an emerging diagnostic tool that is quickly becoming an integral part of clinical decision making. Cancer genomic profiling involves significant challenges including DNA quality and quantity, tumor heterogeneity, and the need to detect a wide variety of complex genetic mutations. Most available comprehensive diagnostic tests rely on primer based amplification or probe based capture methods coupled with NGS to detect hotspot mutation sites or whole regions implicated in disease. These tumor panels utilize highly customized bioinformatics pipelines to perform the difficult task of accurately calling cancer relevant alterations such as single nucleotide variations, small indels or large genomic alterations from the NGS data. In this review, we will discuss the challenges of solid tumor assay design/analysis and report a case study that highlights the need to include complementary technologies (i.e., arrays) and germline analysis in tumor testing to reliably identify copy number alterations and actionable variants.

  12. Comparative studies of the induction of somatic eye-color mutations in an unstable strain of Drosophila melanogaster by MMS and X-rays at different developmental stages

    International Nuclear Information System (INIS)

    Rasmuson, Aa.

    1985-01-01

    The UZ system in Drosophila melanogaster can be used as a screening system for mutagens. This survey is an attempt to correlate the size of the mutated area of the eyes with the age of the larvae at mutagen treatment. X-rays and MMS were used to give an indication of the mechanism of the instability, according to the different kinds of DNA damage induced. The results show that the mean size of red spots decreased with increasing age of larvae at treatment, while the mutation frequencies were increased because of the multiplication of the cells in the eye anlage susceptible to the mutagens. Red spots induced with MMS are smaller in size than X-ray-induced red spots, indicating a delay in the establishment of mutations from chemically-induced lesions compared to irradiation damage. White spots on the other hand were equally large in size, irrespective of inducing agent and about twice the size of the chemically-induced red spots, implying a faster and more direct action for fixation of deletions than for the production of MMS induced shifts in eye color from zeste to red. (Auth.)

  13. Cortisol and somatization.

    Science.gov (United States)

    Rief, W; Auer, C

    2000-05-01

    Somatization symptoms are frequently associated with depression, anxiety, and feelings of distress. These features interact with the activity of the HPA-axis. Therefore we investigated relationships between somatization symptoms and cortisol. Seventy-seven participants were classified into three groups: somatization syndrome (at least eight physical symptoms from the DSM-IV somatization disorder list), somatization syndrome combined with major depression, and healthy controls. The following data were collected: salivary cortisol at three time points (morning, afternoon, evening), nighttime urinary cortisol, serum cortisol after the dexamethasone suppression test (DST), and psychological variables such as depression, anxiety, somatization, and hypochondriasis. Salivary cortisol showed typical diurnal variations. However, the groups did not differ on any of the cortisol variables. A possible explanation may be counteracting effects of somatization and depression. Exploratory correlational analyses revealed that associations between cortisol and psychopathological variables were time-dependent. DST results correlated with psychological aspects of somatization, but not with the number of somatoform symptoms per se.

  14. Management of somatic symptoms

    DEFF Research Database (Denmark)

    Schröder, Andreas; Dimsdale, Joel

    2014-01-01

    on the recognition and effective management of patients with excessive and disabling somatic symptoms. The clinical presentation of somatic symptoms is categorized into three groups of patients: those with multiple somatic symptoms, those with health anxiety, and those with conversion disorder. The chapter provides...

  15. 'Haruna': uma nova mutação somática natural da videira 'Itália' 'Haruna': a new natural somatic mutation of 'Italia' grapevine

    Directory of Open Access Journals (Sweden)

    Adriane Marinho de Assis

    2013-03-01

    Full Text Available O objetivo deste estudo foi descrever as principais características físico-químicas e produtivas da uva fina de mesa 'Haruna', uma nova mutação natural originada da cv. Itália, em Uraí-PR, Brasil. O formato das bagas, elipsoide alongado bastante expressivo, é uma das características que mais difere essa nova mutação da uva 'Itália'. As bagas apresentam coloração verde-clara, tendendo ao amarelo na maturação plena, com pincel e polpa verde, crocante, firme, textura carnosa e de sabor moscatel, enquanto os cachos apresentam formato cilíndrico-cônico. O ciclo, bem como o desempenho produtivo e a suscetibilidade às doenças fúngicas assemelham- se aos da cv. Itália. Durante a maturação plena, apresenta teor médio de sólidos solúveis de 16,2ºBrix, superior à 'Itália, 0,5% de ácido tartárico e índice de maturação de 31,2. Trata-se de uma nova cultivar de uva fina de mesa com bom potencial de cultivo no Brasil.The aim of this study was to describe the main physical -chemical and productive characteristics of 'Haruna' table grape, a new natural mutation originated from cv. Italia, in Uraí, PR, Brazil. The berries present a very expressive large oval shape, which is the main characteristic that differ this new mutation from 'Italia' grape. The berries color is light green, tending to yellow at full maturity, with brush and flesh green, crunchy, firm, with fleshy texture and moscatel flavor, while the clusters present cylindrical-conical shape. The cycle, as well as the production performance and the susceptibility to fungal diseases is similar to the cv. Italia. During the full maturation, it has an average content of soluble solids of 16.2ºBrix, higher than 'Italia', 0.5% of tartaric acid and maturation index of 31.2. This is a new cultivar of fine table grape with potential for cultivation in Brazil.

  16. No evidence for functional inactivation of wild-type p53 protein by MDM2 overexpression in gastric carcinogenesis

    NARCIS (Netherlands)

    Blok, P.; Craanen, M. E.; Dekker, W.; Offerhaus, G. J.; Tytgat, G. N.

    1998-01-01

    Inactivation of wild-type p53 during gastric carcinogenesis is usually caused by mutations within exons 5-8 of the p53 gene leading to mutated, usually immunohistochemically detectable p53 proteins. However, functional inactivation of wild-type p53, mimicking mutational inactivation, may also result

  17. Molecular IgV(H) analysis demonstrates highly somatic mutated B cells in synovialitis of osteoarthritis: a degenerative disease is associated with a specific, not locally generated immune response.

    Science.gov (United States)

    Krenn, V; Hensel, F; Kim, H J; Souto Carneiro, M M; Starostik, P; Ristow, G; König, A; Vollmers, H P; Müller-Hermelink, H K

    1999-11-01

    In osteoarthritis (OA), the synovial tissue exhibits a nonfollicular inflammatory infiltration with a characteristic arrangement of lymphocytes and plasma cells. These arrangements are either small perivascular aggregates with plasma cells surrounding the lymphocytes or small groups of plasma cells, located in the vicinity of small blood vessels. These patterns suggest that B lymphocytes directly differentiate into plasma cells. To understand the B-cell response in OA, we analyzed the V(H) genes from B cells of synovial tissue of nine OA patients (average age, 71.5+/-10.5 years; six female and three male). V(H) gene repertoires were determined from RNA prepared from tissue cryosections and from DNA of single isolated B lymphocytes and plasma cells. The inflammatory infiltrate was analyzed immunohistochemically by detecting CD20, Ki-M4 (follicular dendritic cells), CD4, IgG, IgM, IgA, Ki-67, and by simultaneous demonstration of the plasma-cell-specific antigen CD138 (syndecan-1) and factor VIII. The molecular data demonstrate B cells with a high number of somatic mutations (average, 16.5 to 19.8), and high ratios of replacement to silent mutations in the small lymphocytic/plasmacellular aggregates of OA. In the tissue cryosections, the values of the sigmaR/sigmaS at the complementarity determining regions were 5.3 and 2.0 in the framework regions. For both the isolated B lymphocytes and plasma cells, the value of this ratio in the complementarity determining regions was 3.5. In the framework regions, the values of this ratio were 2.0 for the isolated B cells and 1.8 for the plasma cells. B lymphocytes and plasma cells exhibited a distribution not described thus far. Two patterns of B-cell distribution could be observed: (a) Centrally located CD20+ B and CD4+ and CD8+ T lymphocytes were surrounded directly by IgG (predominantly) or IgA and IgM plasma cells. No proliferating Ki-67-positive cells and no follicular dendritic cells (germinal centers) could be detected in

  18. Depolarized Inactivation Overcomes Impaired Activation to Produce DRG Neuron Hyperexcitability in a Nav1.7 Mutation in a Patient with Distal Limb Pain

    NARCIS (Netherlands)

    Huang, J.; Yang, Y; Dib-Hajj, S.D.; Es, M. van; Zhao, P.; Salomon, J.; Drenth, J.P.; Waxman, S.G.

    2014-01-01

    Sodium channel Nav1.7, encoded by SCN9A, is expressed in DRG neurons and regulates their excitability. Genetic and functional studies have established a critical contribution of Nav1.7 to human pain disorders. We have now characterized a novel Nav1.7 mutation (R1279P) from a female human subject

  19. Induction and identification of somatic mutations with particular reference to perennial plants. Part of a coordinated programme on improvement of vegetatively propagated crops and tree crops through radiation-induced mutations

    International Nuclear Information System (INIS)

    Zubrzycki, H.M.

    1980-06-01

    An attempt was made to obtain resistance of oranges (Citrus sinensis L. Osbeck) and grapefruit (C. paradisi Macf.) to Tristeza virus by induced mutation breeding. Two methods were used. In one, buds were treated with X or gamma radiation. The detached sprouts were subsequently grafted. In the other, a number of chemical mutagens were used: diethyl sulfate or propylenoxide on buds; diethyl sulfate or nitrosemethylurethane on seeds (2400). The selection and isolation of mutants from treated buds and seeds, respectively, are described. Intermediate results only are given and discussed

  20. Inactivation of CDK/pRb pathway normalizes survival pattern of lymphoblasts expressing the FTLD-progranulin mutation c.709-1G>A.

    Directory of Open Access Journals (Sweden)

    Carolina Alquezar

    Full Text Available BACKGROUND: Mutations in the progranulin (PGRN gene, leading to haploinsufficiency, cause familial frontotemporal lobar degeneration (FTLD-TDP, although the pathogenic mechanism of PGRN deficit is largely unknown. Allelic loss of PGRN was previously shown to increase the activity of cyclin-dependent kinase (CDK CDK6/pRb pathway in lymphoblasts expressing the c.709-1G>A PGRN mutation. Since members of the CDK family appear to play a role in neurodegenerative disorders and in apoptotic death of neurons subjected to various insults, we investigated the role of CDK6/pRb in cell survival/death mechanisms following serum deprivation. METHODOLOGY/PRINCIPAL FINDINGS: We performed a comparative study of cell viability after serum withdrawal of established lymphoblastoid cell lines from control and carriers of c.709-1G>A PGRN mutation, asymptomatic and FTLD-TDP diagnosed individuals. Our results suggest that the CDK6/pRb pathway is enhanced in the c.709-1G>A bearing lymphoblasts. Apparently, this feature allows PGRN-deficient cells to escape from serum withdrawal-induced apoptosis by decreasing the activity of executive caspases and lowering the dissipation of mitochondrial membrane potential and the release of cytochrome c from the mitochondria. Inhibitors of CDK6 expression levels like sodium butyrate or the CDK6 activity such as PD332991 were able to restore the vulnerability of lymphoblasts from FTLD-TDP patients to trophic factor withdrawal. CONCLUSION/SIGNIFICANCE: The use of PGRN-deficient lymphoblasts from FTLD-TDP patients may be a useful model to investigate cell biochemical aspects of this disease. It is suggested that CDK6 could be potentially a therapeutic target for the treatment of the FTLD-TDP.

  1. Prospects for cellular mutational assays in human populations

    International Nuclear Information System (INIS)

    Mendelsohn, M.L.

    1984-01-01

    Practical, sensitive, and effective human cellular assays for detecting somatic and germinal mutations would have great value in environmental mutagenesis and carcinogenesis studies. Such assays would fill the void between human mutagenicity and the data that exist from short-term tests and from mutagenicity in other species. This paper discusses the following possible human cellular assays: (1) HPRT (hypoxanthine phosphoribosyltransferase) somatic cell mutation based on 6-thioguanine resistance; (2) hemoglobin somatic cell mutation assay; (3) glycophorin somatic cell mutation assay; and (4) LDH-X sperm cell mutation assay. 18 references

  2. Prospects for cellular mutational assays in human populations

    Energy Technology Data Exchange (ETDEWEB)

    Mendelsohn, M.L.

    1984-06-29

    Practical, sensitive, and effective human cellular assays for detecting somatic and germinal mutations would have great value in environmental mutagenesis and carcinogenesis studies. Such assays would fill the void between human mutagenicity and the data that exist from short-term tests and from mutagenicity in other species. This paper discusses the following possible human cellular assays: (1) HPRT (hypoxanthine phosphoribosyltransferase) somatic cell mutation based on 6-thioguanine resistance; (2) hemoglobin somatic cell mutation assay; (3) glycophorin somatic cell mutation assay; and (4) LDH-X sperm cell mutation assay. 18 references.

  3. Somatic mosaicism and female-to-female transmission in a kindred with hemophilia B (factor IX deficiency)

    International Nuclear Information System (INIS)

    Taylor, S.A.M.; Deugau, K.V.; Lillicrap, D.P.

    1991-01-01

    Studies have shown that hemophilia B (Christmas disease; factor IX deficiency) results from many different mutations in the factor IX gene, of which >95% are single nulceotide substitutions. This study has identified a previously unreported form of hemophilia B in a patient who was a somatic mosaic for a guanine-to-cytosine transversion at nucleotide 31,170 in the factor IX gene. This point mutation changes the codon for residue 350 in the catalytic domain of factor IX from a cysteine to a serine. The authors used differential termination of primer extension to confirm and measure the degree of mosaicism. The study shows that a varying proportion of cells from hepatic, renal, smooth muscle, and hematopoietic populations possessed normal as well as mutant factor IX sequences. These results indicate that the mutation in this patient occurred either as an uncorrected half-chromatid mutation in the female gamete or as a replication or postreplication error in the initial mitotic divisions of the zygote preceding implantation. In addition, this kindred also contains two females in successive generations who have moderately severe factor IX deficiency. The molecular pathogenesis of this latter phenomenon has been studied and seems to relate to the unaccompanied expression of the mutant factor IX gene consequent upon a second, as yet undefined, genetic event that has prevented inactivation of sequences including the mutant factor IX gene on the X chromosome inherited from the affected male

  4. Somatization in Parkinson's Disease

    DEFF Research Database (Denmark)

    Carrozzino, Danilo; Bech, Per; Patierno, Chiara

    2017-01-01

    The current systematic review study is aimed at critically analyzing from a clinimetric viewpoint the clinical consequence of somatization in Parkinson's Disease (PD). By focusing on the International Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we...... consequence of such psychiatric symptom should be further evaluated by replacing the clinically inadequate diagnostic label of psychogenic parkinsonism with the psychosomatic concept of persistent somatization as conceived by the Diagnostic Criteria for Psychosomatic Research (DCPR)....

  5. Roles of Mitochondrial DNA Mutations in Stem Cell Ageing

    Directory of Open Access Journals (Sweden)

    Tianhong Su

    2018-03-01

    Full Text Available Mitochondrial DNA (mtDNA mutations accumulate in somatic stem cells during ageing and cause mitochondrial dysfunction. In this review, we summarize the studies that link mtDNA mutations to stem cell ageing. We discuss the age-related behaviours of the somatic mtDNA mutations in stem cell populations and how they potentially contribute to stem cell ageing by altering mitochondrial properties in humans and in mtDNA-mutator mice. We also draw attention to the diverse fates of the mtDNA mutations with different origins during ageing, with potential selective pressures on the germline inherited but not the somatic mtDNA mutations.

  6. Inactivation Data.xlsx

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data set is a spreadsheet that contains results of inactivation experiments that were conducted to to determine the effectiveness of chlorine in inactivating B....

  7. Lethals induced by γ-radiation in drosophila somatic cells

    International Nuclear Information System (INIS)

    Ivanov, A.I.

    1989-01-01

    Exposure of 3-hour drosophila male embryos to γ-radiation during the topographic segregation of the germ anlage nuclei caused recessive sex-linked lethals in somatic cells only. The selectivity of the screening was determined by the ratio of mutation frequencies induced in embryos and adult males. Analysis of lethal mutations shows that a minimal rate of the divergence between germinal and somatic patterns of the cell development is observed in the embryogenesis, the 3d instar larva and prepupa, and maximal in the 1st and 2nd larva and pupa

  8. Hypochondriasis and somatization.

    Science.gov (United States)

    Kellner, R

    1987-11-20

    Between 60% and 80% of healthy individuals experience somatic symptoms in any one week. About 10% to 20% of a random sample of people worry intermittently about illness. A substantial proportion of patients present physicians with somatic complaints for which no organic cause can be found. Patients who are hypochondriacal do not understand the benign nature of functional somatic symptoms and interpret these as evidence of disease. Hypochondriacal concerns range from common short-lived worries to persistent and distressing fears or convictions of having a disease. Hypochondriasis can be secondary to other psychiatric disorders (eg, melancholia or panic disorder), and hypochondriacal attitudes remit when the primary disorder is successfully treated. Patients with primary hypochondriasis are also anxious or depressed, but the fear of disease, or the false belief of having a disease, persists and is the most important feature of their psychopathology. There are substantial differences among hypochondriacal patients in their personalities and psychopathologies. Psychotherapy as well as psychotropic drugs are effective in the treatment of functional somatic symptoms. There are no adequate controlled studies on the value of psychotherapy in hypochondriasis; the recommended guidelines are based on uncontrolled studies of hypochondriasis and on controlled studies of the psychotherapy in similar disorders. The prognosis of functional somatic symptoms as well as that of hypochondriasis is good in a substantial proportion of patients.

  9. Dietary factors and Truncating APC Mutations in Sporadic Colorectal Adenomas

    NARCIS (Netherlands)

    Diergaarde, B.; Tiemersma, E.W.; Braam, H.; Muijen, van G.N.P.; Nagengast, F.M.; Kok, F.J.; Kampman, E.

    2005-01-01

    Inactivating mutations in APC are thought to be early, initiating events in colorectal carcinogenesis. To gain insight into the relationship between diet and inactivating APC mutations, we evaluated associations between dietary factors and the occurrence of these mutations in a Dutch case-control

  10. Dietary factors and truncating APC mutations in sporadic colorectal adenomas.

    NARCIS (Netherlands)

    Diergaarde, B.; Tiemersma, E.W.; Braam, H.; Muijen, G.N.P. van; Nagengast, F.M.; Kok, F.J.; Kampman, E.

    2005-01-01

    Inactivating mutations in APC are thought to be early, initiating events in colorectal carcinogenesis. To gain insight into the relationship between diet and inactivating APC mutations, we evaluated associations between dietary factors and the occurrence of these mutations in a Dutch case-control

  11. Skewed X-inactivation in cloned mice

    International Nuclear Information System (INIS)

    Senda, Sho; Wakayama, Teruhiko; Yamazaki, Yukiko; Ohgane, Jun; Hattori, Naka; Tanaka, Satoshi; Yanagimachi, Ryuzo; Shiota, Kunio

    2004-01-01

    In female mammals, dosage compensation for X-linked genes is accomplished by inactivation of one of two X chromosomes. The X-inactivation ratio (a percentage of the cells with inactivated maternal X chromosomes in the whole cells) is skewed as a consequence of various genetic mutations, and has been observed in a number of X-linked disorders. We previously reported that phenotypically normal full-term cloned mouse fetuses had loci with inappropriate DNA methylation. Thus, cloned mice are excellent models to study abnormal epigenetic events in mammalian development. In the present study, we analyzed X-inactivation ratios in adult female cloned mice (B6C3F1). Kidneys of eight naturally produced controls and 11 cloned mice were analyzed. Although variations in X-inactivation ratio among the mice were observed in both groups, the distributions were significantly different (Ansary-Bradley test, P < 0.01). In particular, 2 of 11 cloned mice showed skewed X-inactivation ratios (19.2% and 86.8%). Similarly, in intestine, 1 of 10 cloned mice had a skewed ratio (75.7%). Skewed X-inactivation was observed to various degrees in different tissues of different individuals, suggesting that skewed X-inactivation in cloned mice is the result of secondary cell selection in combination with stochastic distortion of primary choice. The present study is the first demonstration that skewed X-inactivation occurs in cloned animals. This finding is important for understanding both nuclear transfer technology and etiology of X-linked disorders

  12. Parental somatic mosaicism is underrecognized and influences recurrence risk of genomic disorders

    NARCIS (Netherlands)

    Campbell, I.M.; Yuan, B.; Robberecht, C.; Pfundt, R.P.; Szafranski, P.; McEntagart, M.E.; Nagamani, S.C.; Erez, A.; Bartnik, M.; Wisniowiecka-Kowalnik, B.; Plunkett, K.S.; Pursley, A.N.; Kang, S.H.; Bi, W.; Lalani, S.R.; Bacino, C.A.; Vast, M.; Marks, K.; Patton, M.; Olofsson, P.; Patel, A.; Veltman, J.A.; Cheung, S.W.; Shaw, C.A.; Vissers, L.E.L.M.; Vermeesch, J.R.; Lupski, J.R.; Stankiewicz, P.

    2014-01-01

    New human mutations are thought to originate in germ cells, thus making a recurrence of the same mutation in a sibling exceedingly rare. However, increasing sensitivity of genomic technologies has anecdotally revealed mosaicism for mutations in somatic tissues of apparently healthy parents. Such

  13. Inactivation of Caliciviruses

    Directory of Open Access Journals (Sweden)

    Raymond Nims

    2013-03-01

    Full Text Available The Caliciviridae family of viruses contains clinically important human and animal pathogens, as well as vesivirus 2117, a known contaminant of biopharmaceutical manufacturing processes employing Chinese hamster cells. An extensive literature exists for inactivation of various animal caliciviruses, especially feline calicivirus and murine norovirus. The caliciviruses are susceptible to wet heat inactivation at temperatures in excess of 60 °C with contact times of 30 min or greater, to UV-C inactivation at fluence ≥30 mJ/cm2, to high pressure processing >200 MPa for >5 min at 4 °C, and to certain photodynamic inactivation approaches. The enteric caliciviruses (e.g.; noroviruses display resistance to inactivation by low pH, while the non-enteric species (e.g.; feline calicivirus are much more susceptible. The caliciviruses are inactivated by a variety of chemicals, including alcohols, oxidizing agents, aldehydes, and β-propiolactone. As with inactivation of viruses in general, inactivation of caliciviruses by the various approaches may be matrix-, temperature-, and/or contact time-dependent. The susceptibilities of the caliciviruses to the various physical and chemical inactivation approaches are generally similar to those displayed by other small, non-enveloped viruses, with the exception that the parvoviruses and circoviruses may require higher temperatures for inactivation, while these families appear to be more susceptible to UV-C inactivation than are the caliciviruses.

  14. Germline BAP1 inactivation is preferentially associated with metastatic ocular melanoma and cutaneous-ocular melanoma families.

    Directory of Open Access Journals (Sweden)

    Ching-Ni Jenny Njauw

    Full Text Available BAP1 has been shown to be a target of both somatic alteration in high-risk ocular melanomas (OM and germline inactivation in a few individuals from cancer-prone families. These findings suggest that constitutional BAP1 changes may predispose individuals to metastatic OM and that familial permeation of deleterious alleles could delineate a new cancer syndrome.To characterize BAP1's contribution to melanoma risk, we sequenced BAP1 in a set of 100 patients with OM, including 50 metastatic OM cases and 50 matched non-metastatic OM controls, and 200 individuals with cutaneous melanoma (CM including 7 CM patients from CM-OM families and 193 CM patients from CM-non-OM kindreds.Germline BAP1 mutations were detected in 4/50 patients with metastatic OM and 0/50 cases of non-metastatic OM (8% vs. 0%, p = 0.059. Since 2/4 of the BAP1 carriers reported a family history of CM, we analyzed 200 additional hereditary CM patients and found mutations in 2/7 CM probands from CM-OM families and 1/193 probands from CM-non-OM kindreds (29% vs. 0.52%, p = .003. Germline mutations co-segregated with both CM and OM phenotypes and were associated with the presence of unique nevoid melanomas and highly atypical nevoid melanoma-like melanocytic proliferations (NEMMPs. Interestingly, 7/14 germline variants identified to date reside in C-terminus suggesting that the BRCA1 binding domain is important in cancer predisposition.Germline BAP1 mutations are associated with a more aggressive OM phenotype and a recurrent phenotypic complex of cutaneous/ocular melanoma, atypical melanocytic proliferations and other internal neoplasms (ie. COMMON syndrome, which could be a useful clinical marker for constitutive BAP1 inactivation.

  15. Recurrent Somatic Structural Variations Contribute to Tumorigenesis in Pediatric Osteosarcoma

    Directory of Open Access Journals (Sweden)

    Xiang Chen

    2014-04-01

    Full Text Available Pediatric osteosarcoma is characterized by multiple somatic chromosomal lesions, including structural variations (SVs and copy number alterations (CNAs. To define the landscape of somatic mutations in pediatric osteosarcoma, we performed whole-genome sequencing of DNA from 20 osteosarcoma tumor samples and matched normal tissue in a discovery cohort, as well as 14 samples in a validation cohort. Single-nucleotide variations (SNVs exhibited a pattern of localized hypermutation called kataegis in 50% of the tumors. We identified p53 pathway lesions in all tumors in the discovery cohort, nine of which were translocations in the first intron of the TP53 gene. Beyond TP53, the RB1, ATRX, and DLG2 genes showed recurrent somatic alterations in 29%–53% of the tumors. These data highlight the power of whole-genome sequencing for identifying recurrent somatic alterations in cancer genomes that may be missed using other methods.

  16. Second-hit mosaic mutation in mTORC1 repressor DEPDC5 causes focal cortical dysplasia-associated epilepsy.

    Science.gov (United States)

    Ribierre, Théo; Deleuze, Charlotte; Bacq, Alexandre; Baldassari, Sara; Marsan, Elise; Chipaux, Mathilde; Muraca, Giuseppe; Roussel, Delphine; Navarro, Vincent; Leguern, Eric; Miles, Richard; Baulac, Stéphanie

    2018-04-30

    DEP domain-containing 5 protein (DEPDC5) is a repressor of the recently recognized amino acid-sensing branch of the mTORC1 pathway. So far, its function in the brain remains largely unknown. Germline loss-of-function mutations in DEPDC5 have emerged as a major cause of familial refractory focal epilepsies, with case reports of sudden unexpected death in epilepsy (SUDEP). Remarkably, a fraction of patients also develop focal cortical dysplasia (FCD), a neurodevelopmental cortical malformation. We therefore hypothesized that a somatic second-hit mutation arising during brain development may support the focal nature of the dysplasia. Here, using postoperative human tissue, we provide the proof of concept that a biallelic 2-hit - brain somatic and germline - mutational mechanism in DEPDC5 causes focal epilepsy with FCD. We discovered a mutation gradient with a higher rate of mosaicism in the seizure-onset zone than in the surrounding epileptogenic zone. Furthermore, we demonstrate the causality of a Depdc5 brain mosaic inactivation using CRISPR-Cas9 editing and in utero electroporation in a mouse model recapitulating focal epilepsy with FCD and SUDEP-like events. We further unveil a key role of Depdc5 in shaping dendrite and spine morphology of excitatory neurons. This study reveals promising therapeutic avenues for treating drug-resistant focal epilepsies with mTORC1-targeting molecules.

  17. Genetic and somatic effects in animals maintained on tritiated water

    International Nuclear Information System (INIS)

    Carsten, A.L.; Brooks, A.; Commerford, S.L.; Cronkite, E.P.

    1981-01-01

    The possible genetic (dominant lethal mutations (DLM) and cytogenetic changes in the regenerating liver) and somatic (hematopoietic stem cell changes, growth and nonspecific life time shortening) effects in mice maintained on tritiated water (HTO) over two generations was investigated. Results to date are summarized

  18. Haploid rice plants in mutation studies

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, S [Institute of Radiation Breeding, Ministry of Agriculture and Forestry, Ohmiya, Ibaraki-ken (Japan)

    1970-03-01

    Studies were made on chlorophyll-deficient sectors and diploid-like sectors in haploid rice plants exposed to chronic gamma irradiation, and on germinal mutations in diploid strains derived from the haploid plants. The induction and elimination of somatic mutations in haploid plants and the occurrence of drastic germinal mutations in diploid strains from haploid plants are discussed. (author)

  19. Somatic and genetic effects

    International Nuclear Information System (INIS)

    Broerse, J.J.; Barendsen, G.W.; Kal, H.B.; Kogel, A.J. van der

    1983-01-01

    This book contains the extended abstracts of the contributions of the poster workshop sessions on somatic and genetic effects of the 7th international congress of radiation research. They cover the following main topics: haematopoietic and immune systems, mechanisms of late effects in various tissues, endogenous and exogenous factors in radiation carcinogenesis, teratogenic effects, genetic effects, in vitro transformation, tumour induction in different tissues, carcinogenesis in incorporated tissues, cancer epidemology and risk assessment. refs.; figs.; tabs

  20. Analysis of relation between the mutation frequencies and somatic recombination induced by neutrons and the age of D. Melanogaster larvae; Analisis de la relacion entre las frecuencias de mutacion y recombinacion somaticas inducidas por neutrones y la edad de las larvas en D. Melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Guzman R, J; Zambrano A, F; Paredes G, L; Delfin L, A; Quiroz R, C [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1998-07-01

    Neutrons are subatomic particles with neutral electric charge, equal zero, which are emitted during the fissile material fission in nuclear reactors. It is known a little about biological effects induced by neutrons. There is a world interest in the use of reactors and accelerators for patients radiotherapy using neutrons with the purpose to destroy malignant cells of deep tumours where traditional methods have not given satisfactory results. There for it is required to do wide studies of biological effects of neutrons as well as their dosimetry. It was used the Smart test (Somatic Mutation and Recombination Test) of D. Melanogaster for quantifying the mutation induction and somatic recombination induced by neutrons of the National Institute of Nuclear Research reactor, at power of 300 and 1000 k W, with equivalent doses calculated 95.14 and 190.2 Sv for 300 k W and of 25.64 and 51.29 Sv for 1000 k W, using larvae with 72 or 96 hours aged. It was observed a linear relation between equivalent dose and genetic effects frequency, these last were greater when the reactor power was 1000 k W than those 300 k W. It was observed too that the damage was greater in 96 hours larvae than those 72 hours. The stain size presented an inverse relation with respect to larvae age. It is concluded that the Smart system is sensitive to neutrons effect and it responds of a directly proportional form to radiation dose, as well as to dose rate. It is noted more the effect when are used larvas in pre pupa stage where the irradiation target (imagal cells) is greater. The Smart is sensitive to damage induced by neutrons , thus can be used to studying its direct biological effects or by the use of chemical modulators. (Author)

  1. KIT D816V mutation-positive cell fractions in lesional skin biopsies from adults with systemic mastocytosis

    DEFF Research Database (Denmark)

    Kielsgaard Kristensen, Thomas; Broesby-Olsen, Sigurd; Vestergaard, Hanne

    2013-01-01

    Most adults with systemic mastocytosis (SM) carry the somatic KIT D816V mutation, but the occurrence of the mutation in lesional skin remains to be characterized.......Most adults with systemic mastocytosis (SM) carry the somatic KIT D816V mutation, but the occurrence of the mutation in lesional skin remains to be characterized....

  2. Mammary-specific inactivation of E-cadherin and p53 impairs functional gland development and leads to pleomorphic invasive lobular carcinoma in mice

    Directory of Open Access Journals (Sweden)

    Patrick W. B. Derksen

    2011-05-01

    Breast cancer is the most common malignancy in women of the Western world. Even though a large percentage of breast cancer patients show pathological complete remission after standard treatment regimes, approximately 30–40% are non-responsive and ultimately develop metastatic disease. To generate a good preclinical model of invasive breast cancer, we have taken a tissue-specific approach to somatically inactivate p53 and E-cadherin, the cardinal cell-cell adhesion receptor that is strongly associated with tumor invasiveness. In breast cancer, E-cadherin is found mutated or otherwise functionally silenced in invasive lobular carcinoma (ILC, which accounts for 10–15% of all breast cancers. We show that mammary-specific stochastic inactivation of conditional E-cadherin and p53 results in impaired mammary gland function during pregnancy through the induction of anoikis resistance of mammary epithelium, resulting in loss of epithelial organization and a dysfunctional mammary gland. Moreover, combined inactivation of E-cadherin and p53 induced lactation-independent development of invasive and metastatic mammary carcinomas, which showed strong resemblance to human pleomorphic ILC. Dissemination patterns of mouse ILC mimic the human malignancy, showing metastasis to the gastrointestinal tract, peritoneum, lung, lymph nodes and bone. Our results confirm that loss of E-cadherin contributes to both mammary tumor initiation and metastasis, and establish a preclinical mouse model of human ILC that can be used for the development of novel intervention strategies to treat invasive breast cancer.

  3. The Somatic Genomic Landscape of Glioblastoma

    Science.gov (United States)

    Brennan, Cameron W.; Verhaak, Roel G.W.; McKenna, Aaron; Campos, Benito; Noushmehr, Houtan; Salama, Sofie R.; Zheng, Siyuan; Chakravarty, Debyani; Sanborn, J. Zachary; Berman, Samuel H.; Beroukhim, Rameen; Bernard, Brady; Wu, Chang-Jiun; Genovese, Giannicola; Shmulevich, Ilya; Barnholtz-Sloan, Jill; Zou, Lihua; Vegesna, Rahulsimham; Shukla, Sachet A.; Ciriello, Giovanni; Yung, WK; Zhang, Wei; Sougnez, Carrie; Mikkelsen, Tom; Aldape, Kenneth; Bigner, Darell D.; Van Meir, Erwin G.; Prados, Michael; Sloan, Andrew; Black, Keith L.; Eschbacher, Jennifer; Finocchiaro, Gaetano; Friedman, William; Andrews, David W.; Guha, Abhijit; Iacocca, Mary; O’Neill, Brian P.; Foltz, Greg; Myers, Jerome; Weisenberger, Daniel J.; Penny, Robert; Kucherlapati, Raju; Perou, Charles M.; Hayes, D. Neil; Gibbs, Richard; Marra, Marco; Mills, Gordon B.; Lander, Eric; Spellman, Paul; Wilson, Richard; Sander, Chris; Weinstein, John; Meyerson, Matthew; Gabriel, Stacey; Laird, Peter W.; Haussler, David; Getz, Gad; Chin, Lynda

    2013-01-01

    We describe the landscape of somatic genomic alterations based on multi-dimensional and comprehensive characterization of more than 500 glioblastoma tumors (GBMs). We identify several novel mutated genes as well as complex rearrangements of signature receptors including EGFR and PDGFRA. TERT promoter mutations are shown to correlate with elevated mRNA expression, supporting a role in telomerase reactivation. Correlative analyses confirm that the survival advantage of the proneural subtype is conferred by the G-CIMP phenotype, and MGMT DNA methylation may be a predictive biomarker for treatment response only in classical subtype GBM. Integrative analysis of genomic and proteomic profiles challenges the notion of therapeutic inhibition of a pathway as an alternative to inhibition of the target itself. These data will facilitate the discovery of therapeutic and diagnostic target candidates, the validation of research and clinical observations and the generation of unanticipated hypotheses that can advance our molecular understanding of this lethal cancer. PMID:24120142

  4. Concomitant mutation and epimutation of the MLH1 gene in a Lynch syndrome family.

    Science.gov (United States)

    Cini, Giulia; Carnevali, Ileana; Quaia, Michele; Chiaravalli, Anna Maria; Sala, Paola; Giacomini, Elisa; Maestro, Roberta; Tibiletti, Maria Grazia; Viel, Alessandra

    2015-04-01

    Lynch syndrome (LS) is an inherited predisposition cancer syndrome, typically caused by germline mutations in the mismatch repair genes MLH1, MSH2, MSH6 and PMS2. In the last years, a role for epimutations of the same genes has also been reported. MLH1 promoter methylation is a well known mechanism of somatic inactivation in tumors, and more recently, several cases of constitutional methylation have been identified. In four subjects affected by multiple tumors and belonging to a suspected LS family, we detected a novel secondary MLH1 gene epimutation. The methylation of MLH1 promoter was always linked in cis with a 997 bp-deletion (c.-168_c.116+713del), that removed exon 1 and partially involved the promoter of the same gene. Differently from cases with constitutional primary MLH1 inactivation, this secondary methylation was allele-specific and CpGs of the residual promoter region were totally methylated, leading to complete allele silencing. In the colon tumor of the proband, MLH1 and PMS2 expression was completely lost as a consequence of a pathogenic somatic point mutation (MLH1 c.199G>A, p.Gly67Arg) that also abrogated local methylation by destroying a CpG site. The evidences obtained highlight how MLH1 mutations and epimutations can reciprocally influence each other and suggest that an altered structure of the MLH1 locus results in epigenetic alteration. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. The somatic FAH C.1061C>A change counteracts the frequent FAH c.1062+5G>A mutation and permits U1snRNA-based splicing correction

    NARCIS (Netherlands)

    Scalet, Daniela; Sacchetto, Claudia; Bernardi, Francesco; Pinotti, Mirko; van de Graaf, Stan F. J.; Balestra, Dario

    2018-01-01

    In tyrosinaemia type 1(HT1), a mosaic pattern of fumarylacetoacetase (FAH) immunopositive or immunonegative nodules in liver tissue has been reported in many patients. This aspect is generally explained by a spontaneous reversion of the mutation into a normal genotype. In one HT1 patient carrying

  6. Stepwise decrease in daptomycin susceptibility in clinical Staphylococcus aureus isolates associated with an initial mutation in rpoB and a compensatory inactivation of the clpX gene

    DEFF Research Database (Denmark)

    Bæk, Kristoffer Torbjørn; Thøgersen, Louise; Mogensen, René G.

    2015-01-01

    , reduced expression of virulence traits, induced expression of the stress-associated transcriptional regulator, Spx, and slow growth. A subsequent acquired loss-of-function mutation in clpX partly alleviated the growth defect conferred by the rpoB mutation without changing antibiotic susceptibility...

  7. Somatic VHL gene alterations in MEN2-associated medullary thyroid carcinoma

    International Nuclear Information System (INIS)

    Koch, Christian A; Brouwers, Frederieke M; Vortmeyer, Alexander O; Tannapfel, Andrea; Libutti, Steven K; Zhuang, Zhengping; Pacak, Karel; Neumann, Hartmut PH; Paschke, Ralf

    2006-01-01

    Germline mutations in RET are responsible for multiple endocrine neoplasia type 2 (MEN2), an autosomal dominantly inherited cancer syndrome that is characterized by medullary thyroid carcinoma (MTC), pheochromocytoma, and parathyroid hyperplasia/adenoma. Recent studies suggest a 'second hit' mechanism resulting in amplification of mutant RET. Somatic VHL gene alterations are implicated in the pathogenesis of MEN2 pheochromocytomas. We hypothesized that somatic VHL gene alterations are also important in the pathogenesis of MEN2-associated MTC. We analyzed 6 MTCs and 1 C-cell hyperplasia (CCH) specimen from 7 patients with MEN2A and RET germline mutations in codons 609, 618, 620, or 634, using microdissection, microsatellite analysis, phosphorimage densitometry, and VHL mutation analysis. First, we searched for allelic imbalance between mutant and wild-type RET by using the polymorphic markers D10S677, D10S1239, and RET on thyroid tissue from these patients. Evidence for RET amplification by this technique could be demonstrated in 3 of 6 MTCs. We then performed LOH analysis using D3S1038 and D3S1110 which map to the VHL gene locus at 3p25/26. VHL gene deletion was present in 3 MTCs. These 3 MTCs also had an allelic imbalance between mutant and wild-type RET. Mutation analysis of the VHL gene showed a somatic frameshift mutation in 1 MTC that also demonstrated LOH at 3p25/26. In the 2 other MTCs with allelic imbalance of RET and somatic VHL gene deletion, no somatic VHL mutation could be detected. The CCH specimen did neither reveal RET imbalance nor somatic VHL gene alterations. These data suggest that a RET germline mutation is necessary for development of CCH, that allelic imbalance between mutant and wild-type RET may set off tumorigenesis, and that somatic VHL gene alterations may not play a major role in tumorigenesis of MEN2A-associated MTC

  8. Protecting genomic integrity in somatic cells and embryonic stem cells

    International Nuclear Information System (INIS)

    Hong, Y.; Cervantes, R.B.; Tichy, E.; Tischfield, J.A.; Stambrook, P.J.

    2007-01-01

    Mutation frequencies at some loci in mammalian somatic cells in vivo approach 10 -4 . The majority of these events occur as a consequence of loss of heterozygosity (LOH) due to mitotic recombination. Such high levels of DNA damage in somatic cells, which can accumulate with age, will cause injury and, after a latency period, may lead to somatic disease and ultimately death. This high level of DNA damage is untenable for germ cells, and by extrapolation for embryonic stem (ES) cells, that must recreate the organism. ES cells cannot tolerate such a high frequency of damage since mutations will immediately impact the altered cell, and subsequently the entire organism. Most importantly, the mutations may be passed on to future generations. ES cells, therefore, must have robust mechanisms to protect the integrity of their genomes. We have examined two such mechanisms. Firstly, we have shown that mutation frequencies and frequencies of mitotic recombination in ES cells are about 100-fold lower than in adult somatic cells or in isogenic mouse embryonic fibroblasts (MEFs). A second complementary protective mechanism eliminates those ES cells that have acquired a mutational burden, thereby maintaining a pristine population. Consistent with this hypothesis, ES cells lack a G1 checkpoint, and the two known signaling pathways that mediate the checkpoint are compromised. The checkpoint kinase, Chk2, which participates in both pathways is sequestered at centrosomes in ES cells and does not phosphorylate its substrates (i.e. p53 and Cdc25A) that must be modified to produce a G1 arrest. Ectopic expression of Chk2 does not rescue the p53-mediated pathway, but does restore the pathway mediated by Cdc25A. Wild type ES cells exposed to ionizing radiation do not accumulate in G1 but do so in S-phase and in G2. ES cells that ectopically express Chk2 undergo cell cycle arrest in G1 as well as G2, and appear to be protected from apoptosis

  9. Germline contamination and leakage in whole genome somatic single nucleotide variant detection.

    Science.gov (United States)

    Sendorek, Dorota H; Caloian, Cristian; Ellrott, Kyle; Bare, J Christopher; Yamaguchi, Takafumi N; Ewing, Adam D; Houlahan, Kathleen E; Norman, Thea C; Margolin, Adam A; Stuart, Joshua M; Boutros, Paul C

    2018-01-31

    The clinical sequencing of cancer genomes to personalize therapy is becoming routine across the world. However, concerns over patient re-identification from these data lead to questions about how tightly access should be controlled. It is not thought to be possible to re-identify patients from somatic variant data. However, somatic variant detection pipelines can mistakenly identify germline variants as somatic ones, a process called "germline leakage". The rate of germline leakage across different somatic variant detection pipelines is not well-understood, and it is uncertain whether or not somatic variant calls should be considered re-identifiable. To fill this gap, we quantified germline leakage across 259 sets of whole-genome somatic single nucleotide variant (SNVs) predictions made by 21 teams as part of the ICGC-TCGA DREAM Somatic Mutation Calling Challenge. The median somatic SNV prediction set contained 4325 somatic SNVs and leaked one germline polymorphism. The level of germline leakage was inversely correlated with somatic SNV prediction accuracy and positively correlated with the amount of infiltrating normal cells. The specific germline variants leaked differed by tumour and algorithm. To aid in quantitation and correction of leakage, we created a tool, called GermlineFilter, for use in public-facing somatic SNV databases. The potential for patient re-identification from leaked germline variants in somatic SNV predictions has led to divergent open data access policies, based on different assessments of the risks. Indeed, a single, well-publicized re-identification event could reshape public perceptions of the values of genomic data sharing. We find that modern somatic SNV prediction pipelines have low germline-leakage rates, which can be further reduced, especially for cloud-sharing, using pre-filtering software.

  10. A History of the Discovery of Random X Chromosome Inactivation in the Human Female and its Significance

    Directory of Open Access Journals (Sweden)

    Sophia Balderman

    2011-07-01

    Full Text Available Genetic determinants of sex in placental mammals developed by the evolution of primordial autosomes into the male and female sex chromosomes. The Y chromosome determines maleness by the action of the gene SRY, which encodes a protein that initiates a sequence of events prompting the embryonic gonads to develop into testes. The X chromosome in the absence of a Y chromosome results in a female by permitting the conversion of the embryonic gonads into ovaries. We trace the historical progress that resulted in the discovery that one X chromosome in the female is randomly inactivated in early embryogenesis, accomplishing approximate equivalency of X chromosome gene dosage in both sexes. This event results in half of the somatic cells in a tissue containing proteins encoded by the genes of the maternal X chromosome and half having proteins encoded by the genes of the paternal X chromosome, on average, accounting for the phenotype of a female heterozygote with an X chromosome mutation. The hypothesis of X chromosome inactivation as a random event early in embryogenesis was first described as a result of studies of variegated coat color in female mice. Similar results were found in women using the X chromosome-linked gene, glucose-6-phosphate dehydrogenase, studied in red cells. The random inactivation of the X chromosome-bearing genes for isoenzyme types A and B of glucose-6-phosphate dehydrogenase was used to establish the clonal origin of neoplasms in informative women with leiomyomas. Behind these discoveries are the stories of the men and women scientists whose research enlightened these aspects of X chromosome function and their implication for medicine.

  11. Are There Mutator Polymerases?

    Directory of Open Access Journals (Sweden)

    Miguel Garcia-Diaz

    2003-01-01

    Full Text Available DNA polymerases are involved in different cellular events, including genome replication and DNA repair. In the last few years, a large number of novel DNA polymerases have been discovered, and the biochemical analysis of their properties has revealed a long list of intriguing features. Some of these polymerases have a very low fidelity and have been suggested to play mutator roles in different processes, like translesion synthesis or somatic hypermutation. The current view of these processes is reviewed, and the current understanding of DNA polymerases and their role as mutator enzymes is discussed.

  12. The landscape of cancer genes and mutational processes in breast cancer

    NARCIS (Netherlands)

    Stephens, Philip J.; Tarpey, Patrick S.; Davies, Helen; van Loo, Peter; Greenman, Chris; Wedge, David C.; Nik-Zainal, Serena; Martin, Sancha; Varela, Ignacio; Bignell, Graham R.; Yates, Lucy R.; Papaemmanuil, Elli; Beare, David; Butler, Adam; Cheverton, Angela; Gamble, John; Hinton, Jonathan; Jia, Mingming; Jayakumar, Alagu; Jones, David; Latimer, Calli; Lau, King Wai; McLaren, Stuart; McBride, David J.; Menzies, Andrew; Mudie, Laura; Raine, Keiran; Rad, Roland; Chapman, Michael Spencer; Teague, Jon; Easton, Douglas; Langerød, Anita; Lee, Ming Ta Michael; Shen, Chen-Yang; tee, Benita Tan Kiat; Huimin, Bernice Wong; Broeks, Annegien; Vargas, Ana Cristina; Turashvili, Gulisa; Martens, John; Fatima, Aquila; Miron, Penelope; Chin, Suet-Feung; Thomas, Gilles; Boyault, Sandrine; Mariani, Odette; Lakhani, Sunil R.; van de Vijver, Marc; van 't Veer, Laura; Foekens, John

    2012-01-01

    All cancers carry somatic mutations in their genomes. A subset, known as driver mutations, confer clonal selective advantage on cancer cells and are causally implicated in oncogenesis(1), and the remainder are passenger mutations. The driver mutations and mutational processes operative in breast

  13. Osteoporosis and Somatization of Anxiety

    Directory of Open Access Journals (Sweden)

    Maria Papanikou

    2013-12-01

    Full Text Available Chronic stress can now be physiologically traced as a significant player in the creation of osteoporotic bones. The present pilot study involved 100 women (N = 42 have been diagnosed with osteopenia, N = 21 have been diagnosed with osteoporosis, N = 37 had a non-osteoporotic condition who participated in the Hellenic Society of Osteoporosis Association Support. Correlations between somatic symptoms of anxiety and osteoporosis, and among medications and somatization in women were explored. Assessments were based on a self-report demographic questionnaire and on the Short Anxiety Screening Test (SAST administered for detection of anxiety disorder and somatization. Statistical analysis detected non-significant differences regarding the correlation between anxiety symptomatology or somatization due to osteoporosis and osteopenia diagnosis. The same pattern is observed among women’s age group, the occupational and marital status. Hypothesis that the osteoporosis and osteopenia group would manifest significant relationships with the age group and medicines was confirmed, as well as between somatization and medicines that women with osteoporosis and osteopenia undertake. The results suggest that women are not prone to manifest anxiety or somatization in relation to the osteoporosis condition. However, the majority of women with osteoporosis and osteopenia consume more than two medicines other than those for osteoporosis. This quantity and combination they undertake appear to contribute and deteriorate their anxiety/somatization symptomatology. Further research based on a larger sample would give more definite results.

  14. Combining molecular and immunohistochemical analyses of key drivers in primary melanomas: interplay between germline and somatic variations.

    Science.gov (United States)

    Bruno, William; Martinuzzi, Claudia; Dalmasso, Bruna; Andreotti, Virginia; Pastorino, Lorenza; Cabiddu, Francesco; Gualco, Marina; Spagnolo, Francesco; Ballestrero, Alberto; Queirolo, Paola; Grillo, Federica; Mastracci, Luca; Ghiorzo, Paola

    2018-01-19

    Due to the high mutational somatic burden of Cutaneous Malignant Melanoma (CMM) a thorough profiling of the driver mutations and their interplay is necessary to explain the timing of tumorigenesis or for the identification of actionable genetic events. The aim of this study was to establish the mutation rate of some of the key drivers in melanoma tumorigenesis combining molecular analyses and/or immunohistochemistry in 93 primary CMMs from an Italian cohort also characterized for germline status, and to investigate an interplay between germline and somatic variants. BRAF mutations were present in 68% of cases, while CDKN2A germline mutations were found in 16 % and p16 loss in tissue was found in 63%. TERT promoter somatic mutations were detected in 38% of cases while the TERT -245T>C polymorphism was found in 51% of cases. NRAS mutations were found in 39% of BRAF negative or undetermined cases. NF1 was expressed in all cases analysed. MC1R variations were both considered as a dichotomous variable or scored. While a positive, although not significant association between CDKN2A germline mutations, but not MC1R variants, and BRAF somatic mutation was found, we did not observe other associations between germline and somatic events. A yet undescribed inverse correlation between TERT -245T>C polymorphism and the presence of BRAF mutation was found. It is possible to hypothesize that -245T>C polymorphism could be included in those genotypes which may influence the occurrence of BRAF mutations. Further studies are needed to investigate the role of -245T>C polymorphism as a germline predictor of BRAF somatic mutation status.

  15. A novel DCX missense mutation in a family with X-linked lissencephaly and subcortical band heterotopia syndrome inherited from a low-level somatic mosaic mother: Genetic and functional studies.

    Science.gov (United States)

    Tsai, Meng-Han; Kuo, Pei-Wen; Myers, Candace T; Li, Shih-Wen; Lin, Wei-Che; Fu, Ting-Ying; Chang, Hsin-Yun; Mefford, Heather C; Chang, Yao-Chung; Tsai, Jin-Wu

    2016-09-01

    To study the genetics and functional alteration of a family with X-linked lissencephaly and subcortical band heterotopia. Five affected patients (one male with lissencephaly, four female with subcortical band heterotopia) and their relatives were studied. Sanger sequencing of DCX gene, allele specific PCR and molecular inversion probe technique were performed. Mutant and wild type of the gene products, namely doublecortin, were expressed in cells followed by immunostaining to explore the localization of doublecortin and microtubules in cells. In vitro microtubule-binding protein spin-down assay was performed to quantify the binding ability of doublecortin to microtubules. We identified a novel DCX mutation c.785A > G, p.Asp262Gly that segregated with the affected members of the family. Allele specific PCR and molecular inversion probe technique demonstrated that the asymptomatic female carrier had an 8% mutant allele fraction in DNA derived from peripheral leukocytes. This mother had 7 children, 4 of whom were affected and all four affected siblings carried the mutation. Functional study showed that the mutant doublecortin protein had a significant reduction of its ability to bind microtubules. Low level mosaicism could be a cause of inherited risk from asymptomatic parents for DCX related lissencephaly-subcortical band heterotopia spectrum. This is particularly important in terms of genetic counselling for recurrent risk of future pregnancies. The reduced binding affinity of mutant doublecortin may contribute to developmental malformation of the cerebral cortex. Copyright © 2016 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  16. Ultraviolet inactivation of papain

    International Nuclear Information System (INIS)

    Baugher, J.F.; Grossweiner, L.I.

    1975-01-01

    Flash photolysis transient spectra (lambda > 250 nm) of aqueous papain showed that the initial products are the neutral tryptophan radical Trp (lambdasub(max) 510 nm), the tryptophan triplet state 3 Trp (lambdasub(max) 460 nm), the disulfide bridge electron adduct -SS - - (lambdasub(max) 420 nm) and the hydrated electron esub(aq) - . The -SS - - yield was not altered by nitrous oxide or air, indicating that the formation of this product does not involve electrons in the external medium. The original papain preparation was activated by irradiating under nitrogen. The action spectrum supports previous work attributing the low initial activity to blocking of cysteinyl site 25 with a mixed disulfide. Flask lamp irradiation in nitrogen led to activation at low starting activities and inactivation at higher starting activities, while only inactivation at the same quantum yield was observed with air saturation. The results are consistent with photoionization of an essential tryptophyl residue as the key inactivating step. (author)

  17. Energy parasites trigger oncogene mutation

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Jiří; Pokorný, Jan; Jandová, Anna; Kobilková, J.; Vrba, J.; Vrba, J. jr.

    2016-01-01

    Roč. 92, č. 10 (2016), s. 577-582 ISSN 0955-3002 R&D Projects: GA ČR GA16-12757S Institutional support: RVO:68378271 ; RVO:67985882 Keywords : cancer initiation * cell-mediated immunity * coherent electromagnetic states * genome somatic mutation * LDH virus * parasitic energy consumption Subject RIV: BO - Biophysics Impact factor: 1.992, year: 2016

  18. Somatically acquired structural genetic differences

    DEFF Research Database (Denmark)

    Magaard Koldby, Kristina; Nygaard, Marianne; Christensen, Kaare

    2016-01-01

    Structural genetic variants like copy number variants (CNVs) comprise a large part of human genetic variation and may be inherited as well as somatically acquired. Recent studies have reported the presence of somatically acquired structural variants in the human genome and it has been suggested t...... with age.European Journal of Human Genetics advance online publication, 20 April 2016; doi:10.1038/ejhg.2016.34....

  19. Somatic embryogenesis of Carica Papaya

    International Nuclear Information System (INIS)

    Alvina Lindsay Mijen; Rusli Ibrahim

    2006-01-01

    This paper describes the somatic embryogenesis of Carica papaya. Culture medium used was1/2 strength MS basal medium supplemented with 6% sucrose, 0.27 % agar, glutamine and various concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D). After 8 weeks in culture, the best concentration of 2,4-D to induce somatic embryo is at 45.2 μM. (Author)

  20. Monitoring Milk Somatic Cell Counts

    Directory of Open Access Journals (Sweden)

    Gheorghe Şteţca

    2014-11-01

    Full Text Available The presence of somatic cells in milk is a widely disputed issue in milk production sector. The somatic cell counts in raw milk are a marker for the specific cow diseases such as mastitis or swollen udder. The high level of somatic cells causes physical and chemical changes to milk composition and nutritional value, and as well to milk products. Also, the mastitic milk is not proper for human consumption due to its contribution to spreading of certain diseases and food poisoning. According to these effects, EU Regulations established the maximum threshold of admitted somatic cells in raw milk to 400000 cells / mL starting with 2014. The purpose of this study was carried out in order to examine the raw milk samples provided from small farms, industrial type farms and milk processing units. There are several ways to count somatic cells in milk but the reference accepted method is the microscopic method described by the SR EN ISO 13366-1/2008. Generally samples registered values in accordance with the admissible limit. By periodical monitoring of the somatic cell count, certain technological process issues are being avoided and consumer’s health ensured.

  1. Mutation analysis of inhibitory guanine nucleotide binding protein alpha (GNAI) loci in young and familial pituitary adenomas.

    Science.gov (United States)

    Demir, Hande; Donner, Iikki; Kivipelto, Leena; Kuismin, Outi; Schalin-Jäntti, Camilla; De Menis, Ernesto; Karhu, Auli

    2014-01-01

    Pituitary adenomas are neoplasms of the anterior pituitary lobe and account for 15-20% of all intracranial tumors. Although most pituitary tumors are benign they can cause severe symptoms related to tumor size as well as hypopituitarism and/or hypersecretion of one or more pituitary hormones. Most pituitary adenomas are sporadic, but it has been estimated that 5% of patients have a familial background. Germline mutations of the tumor suppressor gene aryl hydrocarbon receptor-interacting protein (AIP) predispose to hereditary pituitary neoplasia. Recently, it has been demonstrated that AIP mutations predispose to pituitary tumorigenesis through defective inhibitory GTP binding protein (Gαi) signaling. This finding prompted us to examine whether germline loss-of-function mutations in inhibitory guanine nucleotide (GTP) binding protein alpha (GNAI) loci are involved in genetic predisposition of pituitary tumors. To our knowledge, this is the first time GNAI genes are sequenced in order to examine the occurrence of inactivating germline mutations. Thus far, only somatic gain-of-function hot-spot mutations have been studied in these loci. Here, we have analyzed the coding regions of GNAI1, GNAI2, and GNAI3 in a set of young sporadic somatotropinoma patients (n = 32; mean age of diagnosis 32 years) and familial index cases (n = 14), thus in patients with a disease phenotype similar to that observed in AIP mutation carriers. In addition, expression of Gαi proteins was studied in human growth hormone (GH), prolactin (PRL), adrenocorticotropic hormone (ACTH)-secreting and non-functional pituitary tumors. No pathogenic germline mutations affecting the Gαi proteins were detected. The result suggests that loss-of-function mutations of GNAI loci are rare or nonexistent in familial pituitary adenomas.

  2. SOMATIC EMBRYOGENESIS AND MORPHOANATOMY OF Ocotea porosa SOMATIC EMBRYOS

    Directory of Open Access Journals (Sweden)

    Luciana Luiza Pelegrini

    2013-01-01

    Full Text Available Ocotea porosa seeds have strong tegument dormancy, recalcitrant behavior, low and irregular germination and that makes its natural propagation difficult. The aim of this study was to establish a protocol of regeneration of Ocotea porosa from somatic embryogenesis. Immature embryonic axes were inoculated on WPM culture medium supplemented with 2.4-D (200 μM combined or not with hydrolyzed casein or glutamine (0.5 or 1 g l-1, during 90 days. The repetitive embryogenesis was induced on medium with 2.4-D (22.62 μM combined with 2-iP (2.46 μM followed by transfer to culture medium with hydrolyzed casein or glutamine (1 g l-1 during 90 days. The maturation of somatic embryos was tested in culture medium containing NAA (0.5 μM and 2-iP (5; 10 and 20 μM. The highest percentage of somatic embryos induction (8.3% was observed in WPM culture medium containing 200 μM 2.4-D and 1 g L-1 hydrolyzed casein and the development of somatic embryos occurred indirectly. Repetitive somatic embryogenesis was promoted in WPM medium containing hydrolyzed casein or glutamine. However, the culture medium containing hydrolyzed casein promoted the maintenance of embryogenic capacity for more than two years. During the maturity phase, there was a low progression of globular embryos to cordiform and torpedo stages. The different ontogenetic stages of somatic embryos of Ocotea porosa were characterized by histological studies.

  3. SOMATIC EMBRYOGENESIS AND MORPHOANATOMY OF Ocotea porosa SOMATIC EMBRYOS

    Directory of Open Access Journals (Sweden)

    Luciana Luiza Pelegrini

    2013-12-01

    Full Text Available http://dx.doi.org/10.5902/1980509812343Ocotea porosa seeds have strong tegument dormancy, recalcitrant behavior, low and irregular germinationand that makes its natural propagation difficult. The aim of this study was to establish a protocol ofregeneration of Ocotea porosa from somatic embryogenesis. Immature embryonic axes were inoculatedon WPM culture medium supplemented with 2.4-D (200 μM combined or not with hydrolyzed casein orglutamine (0.5 or 1 g l-1, during 90 days. The repetitive embryogenesis was induced on medium with 2.4-D(22.62 μM combined with 2-iP (2.46 μM followed by transfer to culture medium with hydrolyzed caseinor glutamine (1 g l-1 during 90 days. The maturation of somatic embryos was tested in culture mediumcontaining NAA (0.5 μM and 2-iP (5; 10 and 20 μM. The highest percentage of somatic embryos induction(8.3% was observed in WPM culture medium containing 200 μM 2.4-D and 1 g L-1 hydrolyzed casein andthe development of somatic embryos occurred indirectly. Repetitive somatic embryogenesis was promotedin WPM medium containing hydrolyzed casein or glutamine. However, the culture medium containinghydrolyzed casein promoted the maintenance of embryogenic capacity for more than two years. Duringthe maturity phase, there was a low progression of globular embryos to cordiform and torpedo stages.The different ontogenetic stages of somatic embryos of Ocotea porosa were characterized by histologicalstudies.

  4. Feeding the world with induced mutations and biotechnology

    International Nuclear Information System (INIS)

    Mohan Jain, S.

    2002-01-01

    The paper discussed the following subjects: biotechnology - somaclonal variation, somatic embryogenesis, somatic cell hybridization; induced mutations - in banana, ornamental plants; in vitro mutagenesis; T-DNA insertional mutagenesis. Suggestions for improving biotechnology in the developing countries also presented in the paper

  5. Effect of Cryopreservation and Post-Cryopreservation Somatic Embryogenesis on the Epigenetic Fidelity of Cocoa (Theobroma cacao L.).

    Science.gov (United States)

    Adu-Gyamfi, Raphael; Wetten, Andy; Marcelino Rodríguez López, Carlos

    2016-01-01

    While cocoa plants regenerated from cryopreserved somatic embryos can demonstrate high levels of phenotypic variability, little is known about the sources of the observed variability. Previous studies have shown that the encapsulation-dehydration cryopreservation methodology imposes no significant extra mutational load since embryos carrying high levels of genetic variability are selected against during protracted culture. Also, the use of secondary rather than primary somatic embryos has been shown to further reduce the incidence of genetic somaclonal variation. Here, the effect of in vitro conservation, cryopreservation and post-cryopreservation generation of somatic embryos on the appearance of epigenetic somaclonal variation were comparatively assessed. To achieve this we compared the epigenetic profiles, generated using Methylation Sensitive Amplified Polymorphisms, of leaves collected from the ortet tree and from cocoa somatic embryos derived from three in vitro conditions: somatic embryos, somatic embryos cryopreserved in liquid nitrogen and somatic embryos generated from cryoproserved somatic embryos. Somatic embryos accumulated epigenetic changes but these were less extensive than in those regenerated after storage in LN. Furthermore, the passage of cryopreserved embryos through another embryogenic stage led to further increase in variation. Interestingly, this detected variability appears to be in some measure reversible. The outcome of this study indicates that the cryopreservation induced phenotypic variability could be, at least partially, due to DNA methylation changes. Phenotypic variability observed in cryostored cocoa somatic-embryos is epigenetic in nature. This variability is partially reversible, not stochastic in nature but a directed response to the in-vitro culture and cryopreservation.

  6. Pms2 and uracil-DNA glycosylases act jointly in the mismatch repair pathway to generate Ig gene mutations at A-T base pairs.

    Science.gov (United States)

    Girelli Zubani, Giulia; Zivojnovic, Marija; De Smet, Annie; Albagli-Curiel, Olivier; Huetz, François; Weill, Jean-Claude; Reynaud, Claude-Agnès; Storck, Sébastien

    2017-04-03

    During somatic hypermutation (SHM) of immunoglobulin genes, uracils introduced by activation-induced cytidine deaminase are processed by uracil-DNA glycosylase (UNG) and mismatch repair (MMR) pathways to generate mutations at G-C and A-T base pairs, respectively. Paradoxically, the MMR-nicking complex Pms2/Mlh1 is apparently dispensable for A-T mutagenesis. Thus, how detection of U:G mismatches is translated into the single-strand nick required for error-prone synthesis is an open question. One model proposed that UNG could cooperate with MMR by excising a second uracil in the vicinity of the U:G mismatch, but it failed to explain the low impact of UNG inactivation on A-T mutagenesis. In this study, we show that uracils generated in the G1 phase in B cells can generate equal proportions of A-T and G-C mutations, which suggests that UNG and MMR can operate within the same time frame during SHM. Furthermore, we show that Ung -/- Pms2 -/- mice display a 50% reduction in mutations at A-T base pairs and that most remaining mutations at A-T bases depend on two additional uracil glycosylases, thymine-DNA glycosylase and SMUG1. These results demonstrate that Pms2/Mlh1 and multiple uracil glycosylases act jointly, each one with a distinct strand bias, to enlarge the immunoglobulin gene mutation spectrum from G-C to A-T bases. © 2017 Girelli Zubani et al.

  7. X-chromosome inactivation in development and cancer.

    Science.gov (United States)

    Chaligné, Ronan; Heard, Edith

    2014-08-01

    X-chromosome inactivation represents an epigenetics paradigm and a powerful model system of facultative heterochromatin formation triggered by a non-coding RNA, Xist, during development. Once established, the inactive state of the Xi is highly stable in somatic cells, thanks to a combination of chromatin associated proteins, DNA methylation and nuclear organization. However, sporadic reactivation of X-linked genes has been reported during ageing and in transformed cells and disappearance of the Barr body is frequently observed in cancer cells. In this review we summarise current knowledge on the epigenetic changes that accompany X inactivation and discuss the extent to which the inactive X chromosome may be epigenetically or genetically perturbed in breast cancer. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  8. Development of antibiotic resistance and up-regulation of the antimutator gene pfpI in mutator Pseudomonas aeruginosa due to inactivation of two DNA oxidative repair genes (mutY, mutM)

    DEFF Research Database (Denmark)

    Mandsberg, Lotte Frigaard; Macia, Maria D.; Bergmann, Kirsten R.

    2011-01-01

    showed only a fivefold increase, whereas the single mutant PAOMMgm (mutM) showed a nonsignificant increase in MR compared with PAO1 and the single mutants. Mutations in the regulator nfxB leading to hyperexpression of MexCD-OprJ efflux pump were found as the mechanism of resistance to ciprofloxacin....... In this study, we constructed a double mutant in mutY and mutM (PAOMY-Mgm) and characterized the phenotype and the gene expression profile using microarray and RT-PCR. PAOMY-Mgm presented 28-fold increases in MR compared with wild-type reference strain PAO1. In comparison, the PAOMYgm (mutY) single mutant...... in the double mutant. A better fitness of the mutator compared with PAO1 was found in growth competition experiments in the presence of ciprofloxacin at concentrations just below minimal inhibitory concentration. Up-regulation of the antimutator gene pfpI, that has been shown to provide protection to oxidative...

  9. Mutational landscape of MCPyV-positive and MCPyV-negative Merkel cell carcinomas with implications for immunotherapy.

    Science.gov (United States)

    Goh, Gerald; Walradt, Trent; Markarov, Vladimir; Blom, Astrid; Riaz, Nadeem; Doumani, Ryan; Stafstrom, Krista; Moshiri, Ata; Yelistratova, Lola; Levinsohn, Jonathan; Chan, Timothy A; Nghiem, Paul; Lifton, Richard P; Choi, Jaehyuk

    2016-01-19

    Merkel cell carcinoma (MCC) is a rare but highly aggressive cutaneous neuroendocrine carcinoma, associated with the Merkel cell polyomavirus (MCPyV) in 80% of cases. To define the genetic basis of MCCs, we performed exome sequencing of 49 MCCs. We show that MCPyV-negative MCCs have a high mutation burden (median of 1121 somatic single nucleotide variants (SSNVs) per-exome with frequent mutations in RB1 and TP53 and additional damaging mutations in genes in the chromatin modification (ASXL1, MLL2, and MLL3), JNK (MAP3K1 and TRAF7), and DNA-damage pathways (ATM, MSH2, and BRCA1). In contrast, MCPyV-positive MCCs harbor few SSNVs (median of 12.5 SSNVs/tumor) with none in the genes listed above. In both subgroups, there are rare cancer-promoting mutations predicted to activate the PI3K pathway (HRAS, KRAS, PIK3CA, PTEN, and TSC1) and to inactivate the Notch pathway (Notch1 and Notch2). TP53 mutations appear to be clinically relevant in virus-negative MCCs as 37% of these tumors harbor potentially targetable gain-of-function mutations in TP53 at p.R248 and p.P278. Moreover, TP53 mutational status predicts death in early stage MCC (5-year survival in TP53 mutant vs wild-type stage I and II MCCs is 20% vs. 92%, respectively; P = 0.0036). Lastly, we identified the tumor neoantigens in MCPyV-negative and MCPyV-positive MCCs. We found that virus-negative MCCs harbor more tumor neoantigens than melanomas or non-small cell lung cancers (median of 173, 65, and 111 neoantigens/sample, respectively), two cancers for which immune checkpoint blockade can produce durable clinical responses. Collectively, these data support the use of immunotherapies for virus-negative MCCs.

  10. Mutation breeding in ornamental plants

    International Nuclear Information System (INIS)

    Datta, S.K.

    1990-01-01

    Full text: Mutation induction produced a large number of new promising varieties in ornamental species. 37 new mutants of Chrysanthemum and 14 of rose have been developed by mutations and released for commercialisation. The mutations in flower colour/shape were detected as chimeras in M 1 V 1 , M 1 V 2 , M 1 V 3 generations. The mutation frequency varied with the cultivar and exposure to gamma rays. Comparative analysis of original cultivars and their respective induced mutants on cytomorphological, anatomical and biochemical characters are being carried out for better understanding of the mechanism involved in the origin and evolution of somatic flower colour/shape mutations. Cytological analysis with reference to chromosomal aberrations, chromosome number, ICV, INV and DNA content gave no differences between the original and mutant cultivars. Analysis of florets/petal pigments by TLC and spectrophotometric methods indicated both qualitative and quantitative changes. (author)

  11. Bovine somatic cell nuclear transfer.

    Science.gov (United States)

    Ross, Pablo J; Cibelli, Jose B

    2010-01-01

    Somatic cell nuclear transfer (SCNT) is a technique by which the nucleus of a differentiated cell is introduced into an oocyte from which its genetic material has been removed by a process called enucleation. In mammals, the reconstructed embryo is artificially induced to initiate embryonic development (activation). The oocyte turns the somatic cell nucleus into an embryonic nucleus. This process is called nuclear reprogramming and involves an important change of cell fate, by which the somatic cell nucleus becomes capable of generating all the cell types required for the formation of a new individual, including extraembryonic tissues. Therefore, after transfer of a cloned embryo to a surrogate mother, an offspring genetically identical to the animal from which the somatic cells where isolated, is born. Cloning by nuclear transfer has potential applications in agriculture and biomedicine, but is limited by low efficiency. Cattle were the second mammalian species to be cloned after Dolly the sheep, and it is probably the most widely used species for SCNT experiments. This is, in part due to the high availability of bovine oocytes and the relatively higher efficiency levels usually obtained in cattle. Given the wide utilization of this species for cloning, several alternatives to this basic protocol can be found in the literature. Here we describe a basic protocol for bovine SCNT currently being used in our laboratory, which is amenable for the use of the nuclear transplantation technique for research or commercial purposes.

  12. Manual on mutation breeding. 2. ed.

    International Nuclear Information System (INIS)

    1977-01-01

    The manual is a compilation of work done on the use of induced mutations in plant breeding, and presents general methods and techniques in this field. The use of chemical mutagens and ionizing radiations (X-rays, gamma rays, α- and β-particles, protons, neutrons) are described as well as the effects of these mutagens. The different types of mutations achieved can be divided into genome mutations, chromosome mutations and extra nuclear mutations. Separate chapters deal with mutation techniques in breeding seed-propagated species and asexually propagated plants (examples of development of cultivars given). Plant characters which can be improved by mutation breeding include yield, ripening time, growth habit, disease resistance and tolerance to environmental factors (temperature, salinity etc.). The use of mutagens for some specific plant breeding problems is discussed and attention is also paid to somatic cell genetics in connection with induced mutations. The manual contains a comprehensive bibliography (60 p. references) and a subject index

  13. Somatic symptom profiles in the general population

    DEFF Research Database (Denmark)

    Eliasen, Marie; Jørgensen, Torben; Schröder, Andreas

    2017-01-01

    PURPOSE: The aim of this study was to identify and describe somatic symptom profiles in the general adult population in order to enable further epidemiological research within multiple somatic symptoms. METHODS: Information on 19 self-reported common somatic symptoms was achieved from a population...

  14. The use of radiations to induce useful mutations in fruit trees

    International Nuclear Information System (INIS)

    Donini, B.

    1976-01-01

    The researches carried out at Casaccia in this field had covered the problems of technique of mutagenic treatment, mechanism of mutation induction and methodology of somatic mutation isolation. To enhance the efficiency of somatic mutation induction several conditions during and after the treatment have been studied. More experience has been gained with regard to the induction of somatic mutation which raises from genetical event or by tissue arrangement of a chimaeric shoot apex. To increase the size of mutated sector treatment have been carried out on the primordia in a very early stages and to improve the methodology of somatic mutation special techniques have been adapted of handling the material in the propagation. Possibility for early detection of mutants has been explored in cherry by establishing a correlation between mutants and hormonal content. By using the above mentioned techniques, useful mutants have been isolated in cherries, grapes, olives and peaches. (author)

  15. Mutation induction by heavy ions

    Science.gov (United States)

    Kiefer, J.; Stoll, U.; Schneider, E.

    1994-10-01

    Mutation induction by heavy ions is compared in yeast and mammalian cells. Since mutants can only be recovered in survivors the influence of inactivation cross sections has to be taken into account. It is shown that both the size of the sensitive cellular site as well as track structure play an important role. Another parameter which influences the probability of mutation induction is repair: Contrary to naive assumptions primary radiation damage does not directly lead to mutations but requires modification to reconstitute the genetic machinery so that mutants can survive. The molecular structure of mutations was analyzed after exposure to deuterons by amplification with the aid of polymerase chain reaction. The results-although preliminary-demonstrate that even with densely ionizing particles a large fraction does not carry big deletions which suggests that point mutations may also be induced by heavy ions.

  16. Calreticulin Mutations in Myeloproliferative Neoplasms

    Directory of Open Access Journals (Sweden)

    Noa Lavi

    2014-10-01

    Full Text Available With the discovery of the JAK2V617F mutation in patients with Philadelphia chromosome-negative (Ph− myeloproliferative neoplasms (MPNs in 2005, major advances have been made in the diagnosis of MPNs, in understanding of their pathogenesis involving the JAK/STAT pathway, and finally in the development of novel therapies targeting this pathway. Nevertheless, it remains unknown which mutations exist in approximately one-third of patients with non-mutated JAK2 or MPL essential thrombocythemia (ET and primary myelofibrosis (PMF. At the end of 2013, two studies identified recurrent mutations in the gene encoding calreticulin (CALR using whole-exome sequencing. These mutations were revealed in the majority of ET and PMF patients with non-mutated JAK2 or MPL but not in polycythemia vera patients. Somatic 52-bp deletions (type 1 mutations and recurrent 5-bp insertions (type 2 mutations in exon 9 of the CALR gene (the last exon encoding the C-terminal amino acids of the protein calreticulin were detected and found always to generate frameshift mutations. All detected mutant calreticulin proteins shared a novel amino acid sequence at the C-terminal. Mutations in CALR are acquired early in the clonal history of the disease, and they cause activation of JAK/STAT signaling. The CALR mutations are the second most frequent mutations in Ph− MPN patients after the JAK2V617F mutation, and their detection has significantly improved the diagnostic approach for ET and PMF. The characteristics of the CALR mutations as well as their diagnostic, clinical, and pathogenesis implications are discussed in this review.

  17. Ectopic expression of AID in a non-B cell line triggers A:T and G:C point mutations in non-replicating episomal vectors.

    Directory of Open Access Journals (Sweden)

    Tihana Jovanic

    Full Text Available Somatic hypermutation (SHM of immunoglobulin genes is currently viewed as a two step process initiated by the deamination of deoxycytidine (C to deoxyuridine (U, catalysed by the activation induced deaminase (AID. Phase 1 mutations arise from DNA replication across the uracil residue or the abasic site, generated by the uracil-DNA glycosylase, yielding transitions or transversions at G:C pairs. Phase 2 mutations result from the recognition of the U:G mismatch by the Msh2/Msh6 complex (MutS Homologue, followed by the excision of the mismatched nucleotide and the repair, by the low fidelity DNA polymerase eta, of the gap generated by the exonuclease I. These mutations are mainly focused at A:T pairs. Whereas in activated B cells both G:C and A:T pairs are equally targeted, ectopic expression of AID was shown to trigger only G:C mutations on a stably integrated reporter gene. Here we show that when using non-replicative episomal vectors containing a GFP gene, inactivated by the introduction of stop codons at various positions, a high level of EGFP positive cells was obtained after transient expression in Jurkat cells constitutively expressing AID. We show that mutations at G:C and A:T pairs are produced. EGFP positive cells are obtained in the absence of vector replication demonstrating that the mutations are dependent only on the mismatch repair (MMR pathway. This implies that the generation of phase 1 mutations is not a prerequisite for the expression of phase 2 mutations.

  18. Mutation breedings in ornamental plants

    International Nuclear Information System (INIS)

    Matsubara, Hisao

    1984-01-01

    Several methods of obtaining somatic mutant plants by γ-ray irradiation on pieces of tissues as in vitro adventitious bud technique or small cutting methods with repeated pruning are described. 1) The irradiation to the adventitious buds in the small pieces of organ cultured in vitro and to the small cuttings are employed. Culture beds of agar or of Japanese Kanuma soil were used in vitro culture. In these experiments, Japanese Kanuma soil bed in in vitro culture worked well for root development and transplant of the induced mutants. 2) Combination with in vitro culture and repeated pruning technique were used for isolation and fixation of solid somatic mutant from small sectorial mutation induced by irradiation. This method was successful for begonia, chrysanthemum, aberia and winter daphne. 3) These data indicates that most of the induced mutant plants were non-chimeric, while a few others were chimeric. Among the new varieties, ''Gin-Sei'', ''Ryoku-Ha'', ''Big-Cross'', ''Kaede-Iron'', ''Mei-Fu-Hana-Tsukubane-Utsugi'' and ''Daphne-γ-3'' are non-chimeric, and ''Mini-Mini-Iron'' and ''Orange-Iron'' are chimeric. Moreover, these new varieties have remarkably differed in size and in color pattern from original variety. From the experimental results of somatic mutation, it is indicated that plant tissue culture have enormous potential in radiation breeding and in rapid propagation of the somatic mutant. (author)

  19. Induced somatic mutation in mango, mangifera indica L. cv. Langra

    International Nuclear Information System (INIS)

    Siddiqui, S.H.

    1985-01-01

    Dormant buds of mango (Mangifera indica L. cv. Langra) exposed to acute gamma-irradiation dosages of 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 kiloroentgens (kR), were grafted on to one-year-old seedling stock. Dosages of 2.0 and 3.0 kR were found satisfactory for the purpose, as measured by bud lethality and scion growth. A bud graft from 3.0 kR bore fruits of excellent quality. Compared with the control, the fruits were heavier, larger and had more creamish-yellow pulp. None of the other morphological changes expressed by the mutant fruits, observed over three fruiting seasons, were disadvantageous. The tree habit is being further investigated before the mutant can be considered for release as an improved cultivar. (author)

  20. Functional Analysis of Somatic Mutations in Lung Cancer

    Science.gov (United States)

    2015-10-01

    transformed cells. As shown in Figure 4, the 2nd generation inhibitors afatinib and neratinib , originally developed against the EGFR T790M mutant...show Figure. 4. Effect of EGFR inhibitors on growth of Ba/F3 cells transformed with EGFR exon 20 insertion mutants. Afatinib and neratinib (top panel...and EGFR L858R-expressing cells but, as with afatinib and neratinib , also inhibited wild type EGFR-expressing cells more effectively than cells

  1. Somatic mutation and cell differentiation in neoplastic transformation

    International Nuclear Information System (INIS)

    Huberman, E.; Collart, F.R.

    1987-01-01

    In brief, the authors suggest that tumor formation may result from continuous expression of growth facilitating genes that, as a result of irreversible changes during the initiation step, are placed under the control of genes expressed during normal differentiation. Thus, to understand carcinogenesis, we must decipher the processes that lead to the acquisition of a mature phenotype in both normal and tumor cells and characterize the growth dependency of tumor cells to inducers of cell differentiation. Furthermore, the growth of a variety of tumors may be controlled through the use of inducers of maturation that activate genes located beyond the gene that is altered during tumor initiation. 22 refs., 3 figs

  2. The glycophorin A assay for somatic cell mutations in humans

    International Nuclear Information System (INIS)

    Langlois, R.G.; Bigbee, W.L.; Jensen, R.H.

    1989-01-01

    In this report we briefly review our past experience and some new developments with the GPA assay. Particular emphasis will be placed on two areas that affect the utility of the GPA assay for human population monitoring. The first is our efforts to simplify the GPA assay to make it more generally available for large population studies. The second is to begin to understand some of the characteristics of human hemopoiesis which affect the accumulation and expression of mutant phenotype cells. 11 refs., 4 figs

  3. Mutation studies on garden roses: a review

    International Nuclear Information System (INIS)

    Datta, S.K.

    1997-01-01

    Most of the modern roses are the result of hybridization, selection and spontaneous mutation. For floriculture trade, there is always demand and necessity for new varieties due to change in taste and fashion. Mutation breeding is an established method for crop improvement. Induced somatic mutation breeding holds promise for effective improvement and have high potential for bringing about genetic improvement and it has led to a great burst of flower colour, form, pattern and other variations in rose by using ionizing radiations. The details of prospects and utilization of induced mutation breeding technique for developing new rose varieties have been compiled. (author)

  4. [Somatization disorders of the urogenital tract].

    Science.gov (United States)

    Günthert, E A

    2002-11-01

    Diffuse symptoms in the urogenital region can frequently be explained by somatization disorders. Since they cannot be proven either by laboratory tests or with common technical diagnostic methods, somatization disorders should always be taken into consideration. Somatization disorders are to be considered functional disorders. Since somatization disorders due to muscular tension prevail in the urogenital region, the functional disturbance can be explained by the muscular tension. Subsequently, muscular tension causes the pathophysiological development of symptoms. As a rule they appear as myofascial pain or disorder. Muscular tension can have a psychic origin. The absence of urological findings is typical. Males and females between the ages of 16 and 75 can be affected by somatization disorders in the urogenital region. Somatization disorders due to muscular tension belong to the large group of symptoms due to tension. Diagnostic and therapeutic procedures as well as the pathophysiology of somatization disorders due to muscular tension are illustrated by two detailed case-reports.

  5. Hemoglobin promotes somatic embryogenesis in peanut cultures.

    Science.gov (United States)

    Jayabalan, N; Anthony, P; Davey, M R; Power, J B; Lowe, K C

    2004-02-01

    Critical parameters influencing somatic embryogenesis include growth regulators and oxygen supply. Consequently, the present investigation has focused on optimization of a somatic embryogenic system for peanut (Arachis hypogaea L.) through media supplementation with the auxin, picloram. The latter at 30 mg L(-1) was optimal for inducing regeneration of somatic embryos from cultured explants of zygotic embryos. In contrast, somatic embryogenesis did not occur in the absence of this growth regulator. An assessment has also been made of the beneficial effect on somatic embryogenesis and plant regeneration of the commercial hemoglobin (Hb) solution, Erythrogen. Hemoglobin at 1:50 and 1:100 (v:v) stimulated increases in mean fresh weight (up to a maximum of 57% over control), mean number of explants producing somatic embryos (15%) and mean number of somatic embryos per explant (29%).

  6. Dimensions of somatization and hypochondriasis.

    Science.gov (United States)

    Ford, C V

    1995-05-01

    A significantly large group of patients who communicate their psychosocial distress in the form of physical symptoms are called somatizers. They tend to overuse medical services. The syndromes with which they present have indistinct boundaries, and there tends to be some fluidity of their symptomatic presentations. Underlying psychiatric disorders such as mood disorders, anxiety disorders (including obsessive compulsive disorder), and personality disorders are frequently present.

  7. Pathogen inactivation techniques.

    Science.gov (United States)

    Pelletier, J P R; Transue, S; Snyder, E L

    2006-01-01

    The desire to rid the blood supply of pathogens of all types has led to the development of many technologies aimed at the same goal--eradication of the pathogen(s) without harming the blood cells or generating toxic chemical agents. This is a very ambitious goal, and one that has yet to be achieved. One approach is to shun the 'one size fits all' concept and to target pathogen-reduction agents at the Individual component types. This permits the development of technologies that might be compatible with, for example, plasma products but that would be cytocidal and thus incompatible with platelet concentrates or red blood cell units. The technologies to be discussed include solvent detergent and methylene blue treatments--designed to inactivate plasma components and derivatives; psoralens (S-59--amotosalen) designed to pathogen-reduce units of platelets; and two products aimed at red blood cells, S-303 (a Frale--frangible anchor-linker effector compound) and Inactine (a binary ethyleneimine). A final pathogen-reduction material that might actually allow one material to inactivate all three blood components--riboflavin (vitamin B2)--is also under development. The sites of action of the amotosalen (S-59), the S-303 Frale, Inactine, and riboflavin are all localized in the nucleic acid part of the pathogen. Solvent detergent materials act by dissolving the plasma envelope, thus compromising the integrity of the pathogen membrane and rendering it non-infectious. By disrupting the pathogen's ability to replicate or survive, its infectivity is removed. The degree to which bacteria and viruses are affected by a particular pathogen-reducing technology relates to its Gram-positive or Gram-negative status, to the sporulation characteristics for bacteria, and the presence of lipid or protein envelopes for viruses. Concerns related to photoproducts and other breakdown products of these technologies remain, and the toxicology of pathogen-reduction treatments is a major ongoing area

  8. Free radical inactivation of trypsin

    International Nuclear Information System (INIS)

    Cudina, Ivana; Jovanovic, S.V.

    1988-01-01

    Reactivities of free radical oxidants, radical OH, Br2-anion radical and Cl 3 COO radical and a reductant, CO2-anion radical, with trypsin and reactive protein components were determined by pulse radiolysis of aqueous solutions at pH 7, 20 0 C. Highly reactive free radicals, radical OH, Br2-anion radical and CO2-anion radical, react with trypsin at diffusion controlled rates. Moderately reactive trichloroperoxy radical, k(Cl 3 COO radical + trypsin) preferentially oxidizes histidine residues. The efficiency of inactivation of trypsin by free radicals is inversely proportional to their reactivity. The yields of inactivation of trypsin by radical OH, Br2-anion radical and CO2-anion radical are low, G(inactivation) = 0.6-0.8, which corresponds to ∼ 10% of the initially produced radicals. In contrast, Cl 3 COO radical inactivates trypsin with ∼ 50% efficiency, i.e. G(inactivation) = 3.2. (author)

  9. Inactivation of Microorganisms

    Science.gov (United States)

    Alzamora, Stella Maris; Guerrero, Sandra N.; Schenk, Marcela; Raffellini, Silvia; López-Malo, Aurelio

    Minimal processing techniques for food preservation allow better retention of product flavor, texture, color, and nutrient content than comparable conventional treatments. A wide range of novel alternative physical factors have been intensely investigated in the last two decades. These physical factors can cause inactivation of microorganisms at ambient or sublethal temperatures (e.g., high hydrostatic pressure, pulsed electric fields, ultrasound, pulsed light, and ultraviolet light). These technologies have been reported to reduce microorganism population in foods while avoiding the deleterious effects of severe heating on quality. Among technologies, high-energy ultrasound (i.e., intensities higher than 1 W/cm2, frequencies between 18 and 100 kHz) has attracted considerable interest for food preservation applications (Mason et al., 1996; Povey and Mason, 1998).

  10. Mean inactivation dose (D)

    International Nuclear Information System (INIS)

    Vijayakumar, S.; Ng, T.C.; Raudkivi, U.; Meaney, T.J.

    1990-01-01

    By predicting treatment outcome to radiotherapy from in vitro radiobiological parameters, not only individual patient treatments can be tailored, but also new promising treatment protocols can be tried in patients in whom unfavorable outcome is predicted. In this respect, choosing the right parameter can be very important. Unlike D 0 and N which provide information of the distal part of the survival curve, mean inactivation dose (D) estimates overall radiosensitivity. However, the parameters reflecting the response at the clinically relevant low-dose region are neglected in the literature. In a literature survey of 98 papers in which survival curves or D 0 /N were used, only in 2 D was used. In 21 papers the D 0 /n values were important in drawing conclusions. By calculating D in 3 of these 21 papers, we show that the conclusion drawn may be altered with the use of D. The importance of ''low-dose-region-parameters'' is reviewed. (orig.)

  11. Identifying driver mutations in sequenced cancer genomes

    DEFF Research Database (Denmark)

    Raphael, Benjamin J; Dobson, Jason R; Oesper, Layla

    2014-01-01

    High-throughput DNA sequencing is revolutionizing the study of cancer and enabling the measurement of the somatic mutations that drive cancer development. However, the resulting sequencing datasets are large and complex, obscuring the clinically important mutations in a background of errors, nois...... patterns of mutual exclusivity. These techniques, coupled with advances in high-throughput DNA sequencing, are enabling precision medicine approaches to the diagnosis and treatment of cancer....

  12. The somatic genomic landscape of chromophobe renal cell carcinoma.

    Science.gov (United States)

    Davis, Caleb F; Ricketts, Christopher J; Wang, Min; Yang, Lixing; Cherniack, Andrew D; Shen, Hui; Buhay, Christian; Kang, Hyojin; Kim, Sang Cheol; Fahey, Catherine C; Hacker, Kathryn E; Bhanot, Gyan; Gordenin, Dmitry A; Chu, Andy; Gunaratne, Preethi H; Biehl, Michael; Seth, Sahil; Kaipparettu, Benny A; Bristow, Christopher A; Donehower, Lawrence A; Wallen, Eric M; Smith, Angela B; Tickoo, Satish K; Tamboli, Pheroze; Reuter, Victor; Schmidt, Laura S; Hsieh, James J; Choueiri, Toni K; Hakimi, A Ari; Chin, Lynda; Meyerson, Matthew; Kucherlapati, Raju; Park, Woong-Yang; Robertson, A Gordon; Laird, Peter W; Henske, Elizabeth P; Kwiatkowski, David J; Park, Peter J; Morgan, Margaret; Shuch, Brian; Muzny, Donna; Wheeler, David A; Linehan, W Marston; Gibbs, Richard A; Rathmell, W Kimryn; Creighton, Chad J

    2014-09-08

    We describe the landscape of somatic genomic alterations of 66 chromophobe renal cell carcinomas (ChRCCs) on the basis of multidimensional and comprehensive characterization, including mtDNA and whole-genome sequencing. The result is consistent that ChRCC originates from the distal nephron compared with other kidney cancers with more proximal origins. Combined mtDNA and gene expression analysis implicates changes in mitochondrial function as a component of the disease biology, while suggesting alternative roles for mtDNA mutations in cancers relying on oxidative phosphorylation. Genomic rearrangements lead to recurrent structural breakpoints within TERT promoter region, which correlates with highly elevated TERT expression and manifestation of kataegis, representing a mechanism of TERT upregulation in cancer distinct from previously observed amplifications and point mutations. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. X inactivation in females with X-linked Charcot-Marie-Tooth disease.

    LENUS (Irish Health Repository)

    Murphy, Sinéad M

    2012-07-01

    X-linked Charcot-Marie-Tooth disease (CMT1X) is the second most common inherited neuropathy, caused by mutations in gap junction beta-1 (GJB1). Males have a uniformly moderately severe phenotype while females have a variable phenotype, suggested to be due to X inactivation. We aimed to assess X inactivation pattern in females with CMT1X and correlate this with phenotype using the CMT examination score to determine whether the X inactivation pattern accounted for the variable phenotype in females with CMT1X. We determined X inactivation pattern in 67 females with CMT1X and 24 controls using the androgen receptor assay. We were able to determine which X chromosome carried the GJB1 mutation in 30 females. There was no difference in X inactivation pattern between patients and controls. In addition, there was no correlation between X inactivation pattern in blood and phenotype. A possible explanation for these findings is that the X inactivation pattern in Schwann cells rather than in blood may explain the variable phenotype in females with CMT1X.

  14. Stochastic modeling indicates that aging and somatic evolution in the hematopoetic system are driven by non-cell-autonomous processes.

    Science.gov (United States)

    Rozhok, Andrii I; Salstrom, Jennifer L; DeGregori, James

    2014-12-01

    Age-dependent tissue decline and increased cancer incidence are widely accepted to be rate-limited by the accumulation of somatic mutations over time. Current models of carcinogenesis are dominated by the assumption that oncogenic mutations have defined advantageous fitness effects on recipient stem and progenitor cells, promoting and rate-limiting somatic evolution. However, this assumption is markedly discrepant with evolutionary theory, whereby fitness is a dynamic property of a phenotype imposed upon and widely modulated by environment. We computationally modeled dynamic microenvironment-dependent fitness alterations in hematopoietic stem cells (HSC) within the Sprengel-Liebig system known to govern evolution at the population level. Our model for the first time integrates real data on age-dependent dynamics of HSC division rates, pool size, and accumulation of genetic changes and demonstrates that somatic evolution is not rate-limited by the occurrence of mutations, but instead results from aged microenvironment-driven alterations in the selective/fitness value of previously accumulated genetic changes. Our results are also consistent with evolutionary models of aging and thus oppose both somatic mutation-centric paradigms of carcinogenesis and tissue functional decline. In total, we demonstrate that aging directly promotes HSC fitness decline and somatic evolution via non-cell-autonomous mechanisms.

  15. Mitochondrial mutations and polymorphisms in psychiatric disorders

    NARCIS (Netherlands)

    V. Sequeira (Vasco); M.V. Martin (Maureen); S.M. Rollins; E.A. Moon (Emily); W.E. Bunney (William E); F. MacCiardi (Fabio); S. Lupoli (Sara); G.D. Smith; J. Kelsoe (John); C.N. Magnan (Christophe); M. van Oven (Mannis); P. Baldi (Pierre); D.C. Wallace; M.P. Vawter (Marquis)

    2012-01-01

    textabstractMitochondrial deficiencies with unknown causes have been observed in schizophrenia (SZ) and bipolar disorder (BD) in imaging and postmortem studies. Polymorphisms and somatic mutations in mitochondrial DNA (mtDNA) were investigated as potential causes with next generation sequencing of

  16. Mutations Inactivating Herpes Simplex Virus 1 MicroRNA miR-H2 Do Not Detectably Increase ICP0 Gene Expression in Infected Cultured Cells or Mouse Trigeminal Ganglia.

    Science.gov (United States)

    Pan, Dongli; Pesola, Jean M; Li, Gang; McCarron, Seamus; Coen, Donald M

    2017-01-15

    Herpes simplex virus 1 (HSV-1) latency entails the repression of productive ("lytic") gene expression. An attractive hypothesis to explain some of this repression involves inhibition of the expression of ICP0, a lytic gene activator, by a viral microRNA, miR-H2, which is completely complementary to ICP0 mRNA. To test this hypothesis, we engineered mutations that disrupt miR-H2 without affecting ICP0 in HSV-1. The mutant virus exhibited drastically reduced expression of miR-H2 but showed wild-type levels of infectious virus production and no increase in ICP0 expression in lytically infected cells, which is consistent with the weak expression of miR-H2 relative to the level of ICP0 mRNA in that setting. Following corneal inoculation of mice, the mutant was not significantly different from wild-type virus in terms of infectious virus production in the trigeminal ganglia during acute infection, mouse mortality, or the rate of reactivation from explanted latently infected ganglia. Critically, the mutant was indistinguishable from wild-type virus for the expression of ICP0 and other lytic genes in acutely and latently infected mouse trigeminal ganglia. The latter result may be related to miR-H2 being less effective in inhibiting ICP0 expression in transfection assays than a host microRNA, miR-138, which has previously been shown to inhibit lytic gene expression in infected ganglia by targeting ICP0 mRNA. Additionally, transfected miR-138 reduced lytic gene expression in infected cells more effectively than miR-H2. While this study provides little support for the hypothesis that miR-H2 promotes latency by inhibiting ICP0 expression, the possibility remains that miR-H2 might target other genes during latency. Herpes simplex virus 1 (HSV-1), which causes a variety of diseases, can establish lifelong latent infections from which virus can reactivate to cause recurrent disease. Latency is the most biologically interesting and clinically vexing feature of the virus. Ever since

  17. Function of the activated protein C (APC) autolysis loop in activated FVIII inactivation.

    Science.gov (United States)

    Cramer, Thomas J; Gale, Andrew J

    2011-06-01

    Activated protein C (APC) binds to its substrates activated factor V (FVa) and activated factor VIII (FVIIIa) with a basic exosite that consists of loops 37, 60, 70 and the autolysis loop. These loops have a high density of basic residues, resulting in a positive charge on the surface of APC. Many of these residues are important in the interaction of APC with FVa and FVIIIa. The current study focused on the function of the autolysis loop in the interaction with FVIIIa. This loop was previously shown to interact with FVa, and it inhibits APC inactivation by plasma serpins. Charged residues of the autolysis loop were individually mutated to alanine and the activity of these mutants was assessed in functional FVIIIa inactivation assays. The autolysis loop was functionally important for FVIIIa inactivation. Mutation of R306, K311 and R314 each resulted in significantly reduced FVIIIa inactivation. The inactivating cleavages of FVIIIa at R336 and R562 were affected equally by the mutations. Protein S and FV stimulated cleavage at R562 more than cleavage at R336, independent of mutations in the autolysis loop. Together, these results confirmed that the autolysis loop plays a significant role as part of the basic exosite on APC in the interaction with FVIIIa. © 2011 Blackwell Publishing Ltd.

  18. A continuous culture system of direct somatic embryogenesis in microspore-derived embryos of Brassica juncea.

    Science.gov (United States)

    Prabhudesai, V; Bhaskaran, S

    1993-03-01

    An efficient culture system has been developed for repeated cycles of somatic embryogenesis in microspore-derived embryos of Brassica juncea without a callus phase. Haploid embryos produced through anther culture showed a high propensity for direct production of somatic embryos in response to 2 mgL(-1) BA and 0.1 mgL(-1) NAA. The embryogenic cultures which comprised the elongated embryonal axis of microspore-derived embryos when explanted and grown on the medium of same composition produced a large number of secondary embryos. These somatic embryos in turn underwent axis elongation and produced more somatic embryos when explanted and cultured. This cycle of repetitive somatic embryogenesis continued with undiminished vigour passage after passage and was monitored for more than a year. Somatic embryos from any passage when isolated at cotyledonary stage and grown on auxin-free medium for 5 days and then on a medium containing NAA (0.1 mgL(-1)), developed into complete plants with a profuse root system and were easily established in the soil. The cytology of the root tips of these plants confirmed their haploid nature. The total absence of callus phase makes the system ideal for continuous cloning of androgenic lines, Agrobacterium-mediated transformation and mutation induction studies.

  19. Disease evolution and outcomes in familial AML with germline CEBPA mutations

    DEFF Research Database (Denmark)

    Tawana, Kiran; Wang, Jun; Renneville, Aline

    2015-01-01

    collected from 10 CEBPA-mutated families, representing 24 members with acute myeloid leukemia (AML). Whole-exome (WES) and deep sequencing were performed to genetically profile tumors and define patterns of clonal evolution. Germline CEBPA mutations clustered within the N-terminal and were highly penetrant......, with AML presenting at a median age of 24.5 years (range, 1.75-46 years). In all diagnostic tumors tested (n = 18), double CEBPA mutations (CEBPAdm) were detected, with acquired (somatic) mutations preferentially targeting the C-terminal. Somatic CEBPA mutations were unstable throughout the disease course...

  20. HPV-16 L1 genes with inactivated negative RNA elements induce potent immune responses

    International Nuclear Information System (INIS)

    Rollman, Erik; Arnheim, Lisen; Collier, Brian; Oeberg, Daniel; Hall, Haakan; Klingstroem, Jonas; Dillner, Joakim; Pastrana, Diana V.; Buck, Chris B.; Hinkula, Jorma; Wahren, Britta; Schwartz, Stefan

    2004-01-01

    Introduction of point mutations in the 5' end of the human papillomavirus type 16 (HPV-16) L1 gene specifically inactivates negative regulatory RNA processing elements. DNA vaccination of C57Bl/6 mice with the mutated L1 gene resulted in improved immunogenicity for both neutralizing antibodies as well as for broad cellular immune responses. Previous reports on the activation of L1 by codon optimization may be explained by inactivation of the regulatory RNA elements. The modified HPV-16 L1 DNA that induced anti-HPV-16 immunity may be seen as a complementary approach to protein subunit immunization against papillomavirus

  1. Personality characteristics in patients with somatized disorder

    Directory of Open Access Journals (Sweden)

    Ekaterina Anatolyevna Tolkach

    2010-01-01

    Full Text Available Objective: to study personality characteristics, behavioral style, and modes of relations with their people in patients with somatized disorder. Subjects and methods. Eighty-six patients diagnosed as having somatized disorder were examined using Leary's interpersonal diagnosis system. Results. The author revealed the following personality characteristics and behavioral styles: a depressed need for authoritarianism, dominance, autonomy, aggressiveness, a display of qualities, such as superfriendliness, benevolence, submissiveness, dependency, and suspiciousness. These characteristics give an insight into the development of somatization in patients with somatized disorder.

  2. Activating HER2 mutations in HER2 gene amplification negative breast cancer.

    Science.gov (United States)

    Bose, Ron; Kavuri, Shyam M; Searleman, Adam C; Shen, Wei; Shen, Dong; Koboldt, Daniel C; Monsey, John; Goel, Nicholas; Aronson, Adam B; Li, Shunqiang; Ma, Cynthia X; Ding, Li; Mardis, Elaine R; Ellis, Matthew J

    2013-02-01

    Data from 8 breast cancer genome-sequencing projects identified 25 patients with HER2 somatic mutations in cancers lacking HER2 gene amplification. To determine the phenotype of these mutations, we functionally characterized 13 HER2 mutations using in vitro kinase assays, protein structure analysis, cell culture, and xenograft experiments. Seven of these mutations are activating mutations, including G309A, D769H, D769Y, V777L, P780ins, V842I, and R896C. HER2 in-frame deletion 755-759, which is homologous to EGF receptor (EGFR) exon 19 in-frame deletions, had a neomorphic phenotype with increased phosphorylation of EGFR or HER3. L755S produced lapatinib resistance, but was not an activating mutation in our experimental systems. All of these mutations were sensitive to the irreversible kinase inhibitor, neratinib. These findings show that HER2 somatic mutation is an alternative mechanism to activate HER2 in breast cancer and they validate HER2 somatic mutations as drug targets for breast cancer treatment. We show that the majority of HER2 somatic mutations in breast cancer patients are activating mutations that likely drive tumorigenesis. Several patients had mutations that are resistant to the reversible HER2 inhibitor lapatinib, but are sensitive to the irreversible HER2 inhibitor, neratinib. Our results suggest that patients with HER2 mutation–positive breast cancers could benefit from existing HER2-targeted drugs.

  3. Tumor‐associated DNA mutation detection in individuals undergoing colonoscopy

    OpenAIRE

    Fleshner, Phillip; Braunstein, Glenn D.; Ovsepyan, Gayane; Tonozzi, Theresa R.; Kammesheidt, Anja

    2017-01-01

    Abstract The majority of colorectal cancers (CRC) harbor somatic mutations and epigenetic modifications in the tumor tissue, and some of these mutations can be detected in plasma as circulating tumor DNA (ctDNA). Precancerous colorectal lesions also contain many of these same mutations. This study examined plasma for ctDNA from patients undergoing a screening or diagnostic colonoscopy to determine the sensitivity and specificity of the ctDNA panel for detecting CRC and precancerous lesions. T...

  4. Mediators between bereavement and somatic symptoms

    Directory of Open Access Journals (Sweden)

    Konkolÿ Thege Barna

    2012-06-01

    Full Text Available Abstract Background In our research we examined the frequency of somatic symptoms among bereaved (N = 185 and non-bereaved men and women in a national representative sample (N = 4041 and investigated the possible mediating factors between bereavement status and somatic symptoms. Methods Somatic symptoms were measured by the Patient Health Questionnaire (PHQ-15, anxiety with a four-point anxiety rating scale, and depression with a nine-item shortened version of the Beck Depression Inventory. Results Among the bereaved, somatic symptoms proved to be significantly more frequent in both genders when compared to the non-bereaved, as did anxiety and depression. On the multivariate level, the results show that both anxiety and depression proved to be a mediator between somatic symptoms and bereavement. The effect sizes indicated that for both genders, anxiety was a stronger predictor of somatic symptoms than depression. Conclusions The results of our research indicate that somatic symptoms accompanying bereavement are not direct consequences of this state but they can be traced back to the associated anxiety and depression. These results draw attention to the need to recognize anxiety and depression looming in the background of somatic complaints in bereavement and to the importance of the dissemination of related information.

  5. Sulphur depletion altered somatic embryogenesis in Theobroma ...

    African Journals Online (AJOL)

    Somatic embryogenesis is a useful tool for Theobroma cacao improvement and propagation. Depending on culture medium composition, different morphogenetic structures (including somatic embryo) occur in response to alteration of genes expression patterns and biochemical changes. The effect of SO42- ion deficiency ...

  6. Optimization of somatic embryogenesis procedure for commercial ...

    African Journals Online (AJOL)

    The first objective of this study was to assess and optimize somatic embryo production in a genetically diverse range of cacao genotypes. The primary and secondary somatic embryogenesis response of eight promising cacao clones and a positive control was evaluated using modified versions of standard protocols.

  7. Direct somatic embryogenesis in Swietenia macrophylla King

    Directory of Open Access Journals (Sweden)

    Raúl Collado

    2006-04-01

    Full Text Available Swietenia macrophylla King is difficult to be propagated by tissue culture and there is not an efficient system via organogenesis, due to problems of microbial contamination, phenolic oxidation and death of tissue in the phase of in vitro establishment of explants. In order to establish a protocol for obtaining somatic embryos, zygotic embryos were used as initial plant material. Three combinations of 2,4-D with kinetin were studied, to obtain the formation of somatic embryos. After six weeks of culture, the number of explants with high and low somatic embryogenesis frequency were determined. So that the somatic embryos in globular stage reach the final stages of torpedo and cotyledonal, these were placed in three treatments with 6-BAP (0.2, 0.4 y 0.6 mg.l-1. The number of somatic embryos that reached the torpedo and cotyledonal stages were evaluated after 30 days of culture. Results demonstrated that direct somatic embryogenesis from immature zygotic embryos is obtained in the culture medium composed by MS salts with 4.0 mg.l-1 of 2,4-D and 1.0 mg.l-1 of kinetin. Higher percentage of somatic embryos in cotiledonal stage (91.7 %, was obtained with 0.4 mg.l-1 of 6-BAP. Key word: forestry, growth regulator, mahogany, somatic embryo, tissue culture

  8. Interspecific somatic hybridization between lettuce (Lactuca sativa) and wild species L. virosa.

    Science.gov (United States)

    Matsumoto, E

    1991-02-01

    Somatic hybrids between cultivated lettuce (Lactuca sativa) and a wild species L. virosa were produced by protoplast electrofusion. Hybrid selection was based on inactivation of L. sativa with 20mM iodoacetamide for 15 min, and the inability of L. virosa protoplasts to divide in the culture conditions used. Protoplasts were cultured in agarose beads in a revised MS media. In all 71 calli were formed and 21 of them differentiated shoots on LS medium containing 0.1mg/l NAA and 0.2mg/l BA. Most regenerated plants exhibited intermediate morphology. These plants were confirmed as hybrids by isoenzyme analysis. The majority of somatic hybrids had 2n=4x=36 chromosomes, and had more vigorous growth than either parent. Hybrids had normal flower morphology, but all were sterile.

  9. MMPI screening scales for somatization disorder.

    Science.gov (United States)

    Wetzel, R D; Brim, J; Guze, S B; Cloninger, C R; Martin, R L; Clayton, P J

    1999-08-01

    44 items on the MMPI were identified which appear to correspond to some of the symptoms in nine of the 10 groups on the Perley-Guze checklist for somatization disorder (hysteria). This list was organized into two scales, one reflecting the total number of symptoms endorsed and the other the number of organ systems with at least one endorsed symptom. Full MMPIs were then obtained from 29 women with primary affective disorder and 37 women with somatization disorder as part of a follow-up study of a consecutive series of 500 psychiatric clinic patients seen at Washington University. Women with the diagnosis of somatization disorder scored significantly higher on the somatization disorder scales created from the 44 items than did women with only major depression. These new scales appeared to be slightly more effective in identifying somatization disorder than the use of the standard MMPI scales for hypochondriasis and hysteria. Further development is needed.

  10. Recurrent SOX9 deletion campomelic dysplasia due to somatic mosaicism in the father.

    Science.gov (United States)

    Smyk, M; Obersztyn, E; Nowakowska, B; Bocian, E; Cheung, S W; Mazurczak, T; Stankiewicz, P

    2007-04-15

    Haploinsufficiency of SOX9, a master gene in chondrogenesis and testis development, leads to the semi-lethal skeletal malformation syndrome campomelic dysplasia (CD), with or without XY sex reversal. We report on two children with CD and a phenotypically normal father, a carrier of a somatic mosaic SOX9 deletion. This is the first report of a mosaic deletion of SOX9; few familial CD cases with germline and somatic mutation mosaicism have been described. Our findings confirm the utility of aCGH and indicate that for a more accurate estimate of the recurrence risk for a completely penetrant autosomal dominant disorder, parental somatic mosaicism should be considered in healthy parents. Copyright 2007 Wiley-Liss, Inc.

  11. Somatic Expression of Psychological Problems (Somatization: Examination with Structural Equation Model

    Directory of Open Access Journals (Sweden)

    Tugba Seda Çolak

    2014-09-01

    Full Text Available The main purpose of the research is to define which psychological symptoms (somatization, depression, obsessive ‐ compulsive, hostility, interpersonal sensitivity, anxiety, phobic anxiety, paranoid ideation and psychoticism cause somatic reactions at most. Total effect of these psychological symptoms on somatic symptoms had been investigated. Study was carried out with structural equation model to research the relation between the psychological symptoms and somatization. The main material of the research is formed by the data obtained from 492 people. SCL‐90‐R scale was used in order to obtain the data. As a result of the structural equation analysis, it has been found that 1Psychoticism, phobic anxiety, and paranoid ideation do not predict somatic symptoms.2There is a negative relation between interpersonal sensitivity level mand somatic reactions.3Anxiety symptoms had been found as causative to occur the highest level of somatic reactions.

  12. Novel technologies using radiation and somatic embryogenesis for Kenaf improvement

    International Nuclear Information System (INIS)

    Rusli Ibrahim; Siti Mariam Mohd Nahar; Siti Hajar Mohd Nahar; Abdul Rahim Harun; Azhar Mohamad; Sobri Hussein

    2010-01-01

    Full text: Kenaf (Hibiscus cannabinus L.) is a plant in the Malvaceae family, similar to roselle (Hibiscus sabdariffa), cotton (Gossypium hirsutum L.) and okra (Abelmoschus esculentus), holds a promising potential in the Malaysian bio composite industry. Its long fibres are suitable in the process of making a number of products such as pulp and paper, fibre and particle boards, as well as fibre reinforced plastic components and chemical absorbent. Most varieties of kenaf are photo period sensitive and vegetative growth increases until the daylight period becomes less than 12 h 30 min. flowering is then initiated and the vegetative growth rate declines. At present, most of the varieties planted by the farmers produced very low yield, between 3-5 tons/ha. The aim of this research proposal is to study the potential of using nuclear technique with the use radiation in combination with biotechnology to induce genetic variability in kenaf using somatic embryogenesis. Since mutation is a single cell event, irradiation of cell cultures such as somatic embryos will induce high rate of mutation for selection of desired traits. One of the main objectives of the project was to establish an efficient and productive regeneration system for intact plants from somatic embryos obtained from the original mother plant varieties: G4, V36 dan G393. Once regeneration protocol has been optimized, somatic embryos were irradiated using both acute (high dose rate) and chronic (lower dose rate) gamma irradiation with effective doses (2-3 doses). It takes between 4-5 months to reach maximum height of 4-6 meters from seed propagated plants before they can be harvested. With the use of in vitro mutagenesis, screening and selection of new mutant lines with traits of interest can be achieved within a short period of time (3-5 years). Field evaluations were carried out in collaboration with National Kenaf and Tobacco Board (NKTB) and Kelantan Biotech Corporation Sdn. Bhd. targeted for desired

  13. Mutation in cultured mammalian cells

    International Nuclear Information System (INIS)

    Nakamura, N.; Okada, S.

    1982-01-01

    Mammalian cell cultures were exposed to gamma-rays at various dose rates. Dose-rate effects were observed in cultured somatic cells of the mouse for cell killing and mutations resistant to 6-thioguanine (TGsup(r)) and to methotrexate (MTXsup(r)). Linear quadratic model may be applied to cell killing and TGsup(r) mutations in some cases but can not explain the whole data. Results at low doses with far low dose-rate were not predictable from data at high doses with acute or chronic irradiation. Radioprotective effects of dimethyl sulfoxide were seen only after acute exposure but not after chronic one, suggesting that damages by indirect action of radiations may be potentially reparable by cells. TGsup(r) mutations seem to contain gross structural changes whereas MTXsup(r) ones may have smaller alterations. (Namekawa, K.)

  14. A molecular switch driving inactivation in the cardiac K+ channel HERG.

    Directory of Open Access Journals (Sweden)

    David A Köpfer

    Full Text Available K(+ channels control transmembrane action potentials by gating open or closed in response to external stimuli. Inactivation gating, involving a conformational change at the K(+ selectivity filter, has recently been recognized as a major K(+ channel regulatory mechanism. In the K(+ channel hERG, inactivation controls the length of the human cardiac action potential. Mutations impairing hERG inactivation cause life-threatening cardiac arrhythmia, which also occur as undesired side effects of drugs. In this paper, we report atomistic molecular dynamics simulations, complemented by mutational and electrophysiological studies, which suggest that the selectivity filter adopts a collapsed conformation in the inactivated state of hERG. The selectivity filter is gated by an intricate hydrogen bond network around residues S620 and N629. Mutations of this hydrogen bond network are shown to cause inactivation deficiency in electrophysiological measurements. In addition, drug-related conformational changes around the central cavity and pore helix provide a functional mechanism for newly discovered hERG activators.

  15. Characterization of pathogenic germline mutations in human Protein Kinases

    Directory of Open Access Journals (Sweden)

    Orengo Christine A

    2011-07-01

    Full Text Available Abstract Background Protein Kinases are a superfamily of proteins involved in crucial cellular processes such as cell cycle regulation and signal transduction. Accordingly, they play an important role in cancer biology. To contribute to the study of the relation between kinases and disease we compared pathogenic mutations to neutral mutations as an extension to our previous analysis of cancer somatic mutations. First, we analyzed native and mutant proteins in terms of amino acid composition. Secondly, mutations were characterized according to their potential structural effects and finally, we assessed the location of the different classes of polymorphisms with respect to kinase-relevant positions in terms of subfamily specificity, conservation, accessibility and functional sites. Results Pathogenic Protein Kinase mutations perturb essential aspects of protein function, including disruption of substrate binding and/or effector recognition at family-specific positions. Interestingly these mutations in Protein Kinases display a tendency to avoid structurally relevant positions, what represents a significant difference with respect to the average distribution of pathogenic mutations in other protein families. Conclusions Disease-associated mutations display sound differences with respect to neutral mutations: several amino acids are specific of each mutation type, different structural properties characterize each class and the distribution of pathogenic mutations within the consensus structure of the Protein Kinase domain is substantially different to that for non-pathogenic mutations. This preferential distribution confirms previous observations about the functional and structural distribution of the controversial cancer driver and passenger somatic mutations and their use as a proxy for the study of the involvement of somatic mutations in cancer development.

  16. Fibroblast growth factor signaling is required for early somatic gonad development in zebrafish.

    Science.gov (United States)

    Leerberg, Dena M; Sano, Kaori; Draper, Bruce W

    2017-09-01

    The vertebrate ovary and testis develop from a sexually indifferent gonad. During early development of the organism, primordial germ cells (the gamete lineage) and somatic gonad cells coalesce and begin to undergo growth and morphogenesis to form this bipotential gonad. Although this aspect of development is requisite for a fertile adult, little is known about the genetic regulation of early gonadogenesis in any vertebrate. Here, we provide evidence that fibroblast growth factor (Fgf) signaling is required for the early growth phase of a vertebrate bipotential gonad. Based on mutational analysis in zebrafish, we show that the Fgf ligand 24 (Fgf24) is required for proliferation, differentiation, and morphogenesis of the early somatic gonad, and as a result, most fgf24 mutants are sterile as adults. Additionally, we describe the ultrastructural elements of the early zebrafish gonad and show that distinct somatic cell populations can be identified soon after the gonad forms. Specifically, we show that fgf24 is expressed in an epithelial population of early somatic gonad cells that surrounds an inner population of mesenchymal somatic gonad cells that are in direct contact with the germ cells, and that fgf24 is required for stratification of the somatic tissue. Furthermore, based on gene expression analysis, we find that differentiation of the inner mesenchymal somatic gonad cells into functional cell types in the larval and early juvenile-stage gonad is dependent on Fgf24 signaling. Finally, we argue that the role of Fgf24 in zebrafish is functionally analogous to the role of tetrapod FGF9 in early gonad development.

  17. Colocalization of somatic and meiotic double strand breaks near the Myc oncogene on mouse chromosome 15.

    Science.gov (United States)

    Ng, Siemon H; Maas, Sarah A; Petkov, Petko M; Mills, Kevin D; Paigen, Kenneth

    2009-10-01

    Both somatic and meiotic recombinations involve the repair of DNA double strand breaks (DSBs) that occur at preferred locations in the genome. Improper repair of DSBs during either mitosis or meiosis can lead to mutations, chromosomal aberration such as translocations, cancer, and/or cell death. Currently, no model exists that explains the locations of either spontaneous somatic DSBs or programmed meiotic DSBs or relates them to each other. One common class of tumorigenic translocations arising from DSBs is chromosomal rearrangements near the Myc oncogene. Myc translocations have been associated with Burkitt lymphoma in humans, plasmacytoma in mice, and immunocytoma in rats. Comparing the locations of somatic and meiotic DSBs near the mouse Myc oncogene, we demonstrated that the placement of these DSBs is not random and that both events clustered in the same short discrete region of the genome. Our work shows that both somatic and meiotic DSBs tend to occur in proximity to each other within the Myc region, suggesting that they share common originating features. It is likely that some regions of the genome are more susceptible to both somatic and meiotic DSBs, and the locations of meiotic hotspots may be an indicator of genomic regions more susceptible to DNA damage. (c) 2009 Wiley-Liss, Inc.

  18. Analysis of genetic stability at SSR loci during somatic embryogenesis in maritime pine (Pinus pinaster).

    Science.gov (United States)

    Marum, Liliana; Rocheta, Margarida; Maroco, João; Oliveira, M Margarida; Miguel, Célia

    2009-04-01

    Somatic embryogenesis (SE) is a propagation tool of particular interest for accelerating the deployment of new high-performance planting stock in multivarietal forestry. However, genetic conformity in in vitro propagated plants should be assessed as early as possible, especially in long-living trees such as conifers. The main objective of this work was to study such conformity based on genetic stability at simple sequence repeat (SSR) loci during somatic embryogenesis in maritime pine (Pinus pinaster Ait.). Embryogenic cell lines (ECLs) subjected to tissue proliferation during 6, 14 or 22 months, as well as emblings regenerated from several ECLs, were analyzed. Genetic variation at seven SSR loci was detected in ECLs under proliferation conditions for all time points, and in 5 out of 52 emblings recovered from somatic embryos. Three of these five emblings showed an abnormal phenotype consisting mainly of plagiotropism and loss of apical dominance. Despite the variation found in somatic embryogenesis-derived plant material, no correlation was established between genetic stability at the analyzed loci and abnormal embling phenotype, present in 64% of the emblings. The use of microsatellites in this work was efficient for monitoring mutation events during the somatic embryogenesis in P. pinaster. These molecular markers should be useful in the implementation of new breeding and deployment strategies for improved trees using SE.

  19. 75 FR 6211 - Prospective Grant of Exclusive License: Purified Inactivated Dengue Tetravalent Vaccine...

    Science.gov (United States)

    2010-02-08

    ... Exclusive License: Purified Inactivated Dengue Tetravalent Vaccine Containing a Common 30 Nucleotide Deletion in the 3'-UTR of Dengue Types 1,2,3, and 4 AGENCY: National Institutes of Health, Public Health...., ``Development of Mutations Useful for Attenuating Dengue Viruses and Chimeric Dengue Viruses''-- European Patent...

  20. Distinct pattern of p53 mutations in bladder cancer

    DEFF Research Database (Denmark)

    Spruck, C H; Rideout, W M; Olumi, A F

    1993-01-01

    A distinct mutational spectrum for the p53 tumor suppressor gene in bladder carcinomas was established in patients with known exposures to cigarette smoke. Single-strand conformational polymorphism analysis of exons 5 through 8 of the p53 gene showed inactivating mutations in 16 of 40 (40%) bladder...... tumors from smokers and 13 of 40 (33%) tumors from lifetime nonsmokers. Overall, 13 of the 50 (26%) total point mutations discovered in this and previous work were G:C-->C:G transversions, a relatively rare mutational type in human tumors. In six tumors, identical AGA (Arg)-->ACA (Thr) point mutations...... double mutations, four of which were tandem mutations on the same allele. No double mutations were found in tumors from nonsmoking patients. None of the mutations in smokers were G:C-->T:A transversions, which would be anticipated for exposure to the suspected cigarette smoke carcinogen 4-aminobiphenyl...

  1. Incidence and Outcome of BRCA Mutations in Unselected Patients with Triple Receptor-Negative Breast Cancer.

    LENUS (Irish Health Repository)

    Gonzalez-Angulo, Ana M

    2011-03-01

    To investigate the incidence of germline and somatic BRCA1\\/2 mutations in unselected patients with triple-negative breast cancer (TNBC) and determine the prognostic significance of carrying a mutation. Methods: DNA was obtained from 77 TNBC and normal tissues. BRCA1\\/2 exons\\/flanking regions were sequenced from tumor and patients classified as mutant or wild type (WT). Sequencing was repeated from normal tissue to identify germline and somatic mutations. Patient characteristics were compared with chi-square. Survival was estimated by Kaplan-Meier method and compared with log-rank. Cox proportional hazards models were fit to determine the independent association of mutation status with outcome.

  2. Imprinted X chromosome inactivation: evolution of mechanisms in distantly related mammals

    Directory of Open Access Journals (Sweden)

    Shafagh A. Waters

    2015-03-01

    Full Text Available In females, X chromosome inactivation (XCI ensures transcriptional silencing of one of the two Xs (either in a random or imprinted fashion in somatic cells. Comparing this silencing between species has offered insight into different mechanisms of X inactivation, providing clues into the evolution of this epigenetic process in mammals. Long-noncoding RNAs have emerged as a common theme in XCI of therian mammals (eutherian and marsupial. Eutherian X inactivation is regulated by the noncoding RNA product of XIST, within a cis-acting master control region called the X inactivation center (XIC. Marsupials XCI is XIST independent. Instead, XCI is controlled by the long-noncoding RNA Rsx, which appears to be a functional analog of the eutherian XIST gene, insofar that its transcript coats the inactive X and represses activity of genes in cis. In this review we discuss XCI in eutherians, and contrast imprinted X inactivation in mouse and marsupials. We provide particular focus on the evolution of genomic elements that confer the unique epigenetic features that characterize the inactive X chromosome.

  3. Altering the spectrum of immunoglobulin V gene somatic hypermutation by modifying the active site of AID

    OpenAIRE

    Wang, Meng; Rada, Cristina; Neuberger, Michael S.

    2010-01-01

    High-affinity antibodies are generated by somatic hypermutation with nucleotide substitutions introduced into the IgV in a semirandom fashion, but with intrinsic mutational hotspots strategically located to optimize antibody affinity maturation. The process is dependent on activation-induced deaminase (AID), an enzyme that can deaminate deoxycytidine in DNA in vitro, where its activity is sensitive to the identity of the 5?-flanking nucleotide. As a critical test of whether such DNA deaminati...

  4. Domain IV voltage-sensor movement is both sufficient and rate limiting for fast inactivation in sodium channels.

    Science.gov (United States)

    Capes, Deborah L; Goldschen-Ohm, Marcel P; Arcisio-Miranda, Manoel; Bezanilla, Francisco; Chanda, Baron

    2013-08-01

    Voltage-gated sodium channels are critical for the generation and propagation of electrical signals in most excitable cells. Activation of Na(+) channels initiates an action potential, and fast inactivation facilitates repolarization of the membrane by the outward K(+) current. Fast inactivation is also the main determinant of the refractory period between successive electrical impulses. Although the voltage sensor of domain IV (DIV) has been implicated in fast inactivation, it remains unclear whether the activation of DIV alone is sufficient for fast inactivation to occur. Here, we functionally neutralize each specific voltage sensor by mutating several critical arginines in the S4 segment to glutamines. We assess the individual role of each voltage-sensing domain in the voltage dependence and kinetics of fast inactivation upon its specific inhibition. We show that movement of the DIV voltage sensor is the rate-limiting step for both development and recovery from fast inactivation. Our data suggest that activation of the DIV voltage sensor alone is sufficient for fast inactivation to occur, and that activation of DIV before channel opening is the molecular mechanism for closed-state inactivation. We propose a kinetic model of sodium channel gating that can account for our major findings over a wide voltage range by postulating that DIV movement is both necessary and sufficient for fast inactivation.

  5. Pilates, Mindfulness and Somatic Education.

    Science.gov (United States)

    Caldwell, Karen; Adams, Marianne; Quin, Rebecca; Harrison, Mandy; Greeson, Jeffrey

    2013-12-01

    The Pilates Method is a form of somatic education with the potential to cultivate mindfulness - a mental quality associated with overall well-being. However, controlled studies are needed to determine whether changes in mindfulness are specific to the Pilates Method or also result from other forms of exercise. This quasi-experimental study compared Pilates Method mat classes and recreational exercise classes on measures of mindfulness and well-being at the beginning, middle and end of a 15 week semester. Total mindfulness scores increased overall for the Pilates Method group but not for the exercise control group, and these increases were directly related to end of semester ratings of self-regulatory self-efficacy, perceived stress and mood. Findings suggest that the Pilates Method specifically enhances mindfulness, and these increases are associated with other measures of wellness. The changes in mindfulness identified in this study support the role of the Pilates Method in the mental well-being of its practitioners and its potential to support dancers' overall well-being.

  6. Further evidence for a broader concept of somatization disorder using the somatic symptom index.

    Science.gov (United States)

    Hiller, W; Rief, W; Fichter, M M

    1995-01-01

    Somatization syndromes were defined in a sample of 102 psychosomatic inpatients according to the restrictive criteria of DSM-III-R somatization disorder and the broader diagnostic concept of the Somatic Symptom Index (SSI). Both groups showed a qualitatively similar pattern of psychopathological comorbidity and had elevated scores on measures of depression, hypochondriasis, and anxiety. A good discrimination between mild and severe forms of somatization was found by using the SSI criterion. SSI use accounted for a substantial amount of comorbidity variance, with rates of 15%-20% for depression, 16% for hypochondriasis, and 13% for anxiety. The results provide further evidence for the validity of the SSI concept, which reflects the clinical relevance of somatization in addition to the narrow definition of somatization disorder.

  7. Calreticulin Mutations in Bulgarian MPN Patients.

    Science.gov (United States)

    Pavlov, Ivan; Hadjiev, Evgueniy; Alaikov, Tzvetan; Spassova, Sylva; Stoimenov, Angel; Naumova, Elissaveta; Shivarov, Velizar; Ivanova, Milena

    2018-01-01

    Somatic mutations in JAK2, MPL and CALR are recurrently identified in most of the cases with Philadelphia chromosome negative myeloproliferative neoplasms (MPNs). We applied four molecular genetic methods for identification of CALR exon 9 mutations, including high resolution melt (HRM) analysis, Sanger sequencing, semiconductor target genes sequencing and whole exome sequencing. A total of 78 patients with myeloid malignancies were included in the study. We identified 14 CALR exon 9 mutated cases out of 78 studied patients with myeloid malignancies. All mutated patients were diagnosed with MPN being either PMF (n = 7) or ET (n = 7). Nine cases had type 1 mutations and 5 cases had type 2 mutations. CALR exon 9, MPL exon 10 and JAK2 p. V617F were mutually exclusive. There were no statistically significant differences in the hematological parameters between the cases with CALR and JAK2 or MPL mutations. Notably, all four techniques were fully concordant in the detection of CALR mutations. This is one of the few reports on the CALR mutations frequency in South-eastern populations. Our study shows that the frequency and patterns of these mutations is identical to those in the patients' cohorts from Western countries. Besides we demonstrated the utility of four different methods for their detection.

  8. symptomatology and comorbidity of somatization disorder amongst

    African Journals Online (AJOL)

    underlying mental disorder, manifesting solely as somatic symptoms or with ... unsatisfactory visit and seemingly ineffective treatment plan. ... patients of all ages and both gender with various ..... identity and physical health: Interdisciplinary.

  9. recA+-dependent inactivation of the lambda repressor in Escherichia coli lysogens by γ-radiation and by tif expression

    International Nuclear Information System (INIS)

    West, S.C.; Powell, K.A.; Emmerson, P.T.

    1975-01-01

    When lambda lysogens of E. coli are induced by γ-radiation the lambda repressor, as measured by its specific binding to lambda DNA, is rapidly inactivated by a recA + -dependent process which does not require new protein synthesis. This rapid inactivation is similar to inactivation of repressor by expression of the temperature sensitive E. coli mutation tif. In contrast, induction by UV irradiation or mitomycin C treatment requires new protein synthesis and there is a lag before the repressor is inactivated (Tomizawa and Ogawa, 1967; Shinagawa and Itoh, 1973). (orig.) [de

  10. Somatic surveillance: corporeal control through information networks

    OpenAIRE

    Monahan, Torin; Wall, Tyler

    2007-01-01

    Somatic surveillance is the increasingly invasive technological monitoring of and intervention into body functions. Within this type of surveillance regime, bodies are recast as nodes on vast information networks, enabling corporeal control through remote network commands, automated responses, or self-management practices. In this paper, we investigate three developments in somatic surveillance: nanotechnology systems for soldiers on the battlefield, commercial body-monitoring systems for hea...

  11. Dance and Somatic Inquiry in Studios and Community Dance Programs.

    Science.gov (United States)

    Eddy, Martha Hart

    2002-01-01

    Addresses pragmatic aspects of somatics in the public sector, investigating the fit of somatics within various institutions and settings, including universities, professional schools, and community programs. The article explores issues such as somatic movement approaches, certification, academic degrees in somatic study, confusions within the…

  12. six novel mutations in the TSC1 and TSC2 genes

    Indian Academy of Sciences (India)

    M. GLUSHKOVA

    2018-04-30

    Apr 30, 2018 ... RESEARCH ARTICLE ... nant disorder caused by inactivating TSC1 or TSC2 gene variants (Van ... premature protein truncation, while missense mutations are rare ..... TSC2 variants in our cohort are missense, frame-shift.

  13. Multicellularity makes somatic differentiation evolutionarily stable

    Science.gov (United States)

    Wahl, Mary E.; Murray, Andrew W.

    2016-01-01

    Many multicellular organisms produce two cell lineages: germ cells, whose descendants produce the next generation, and somatic cells, which support, protect, and disperse the germ cells. This germ-soma demarcation has evolved independently in dozens of multicellular taxa but is absent in unicellular species. A common explanation holds that in these organisms, inefficient intercellular nutrient exchange compels the fitness cost of producing nonreproductive somatic cells to outweigh any potential benefits. We propose instead that the absence of unicellular, soma-producing populations reflects their susceptibility to invasion by nondifferentiating mutants that ultimately eradicate the soma-producing lineage. We argue that multicellularity can prevent the victory of such mutants by giving germ cells preferential access to the benefits conferred by somatic cells. The absence of natural unicellular, soma-producing species previously prevented these hypotheses from being directly tested in vivo: to overcome this obstacle, we engineered strains of the budding yeast Saccharomyces cerevisiae that differ only in the presence or absence of multicellularity and somatic differentiation, permitting direct comparisons between organisms with different lifestyles. Our strains implement the essential features of irreversible conversion from germ line to soma, reproductive division of labor, and clonal multicellularity while maintaining sufficient generality to permit broad extension of our conclusions. Our somatic cells can provide fitness benefits that exceed the reproductive costs of their production, even in unicellular strains. We find that nondifferentiating mutants overtake unicellular populations but are outcompeted by multicellular, soma-producing strains, suggesting that multicellularity confers evolutionary stability to somatic differentiation. PMID:27402737

  14. Targeted capture massively parallel sequencing analysis of LCIS and invasive lobular cancer: Repertoire of somatic genetic alterations and clonal relationships.

    Science.gov (United States)

    Sakr, Rita A; Schizas, Michail; Carniello, Jose V Scarpa; Ng, Charlotte K Y; Piscuoglio, Salvatore; Giri, Dilip; Andrade, Victor P; De Brot, Marina; Lim, Raymond S; Towers, Russell; Weigelt, Britta; Reis-Filho, Jorge S; King, Tari A

    2016-02-01

    Lobular carcinoma in situ (LCIS) has been proposed as a non-obligate precursor of invasive lobular carcinoma (ILC). Here we sought to define the repertoire of somatic genetic alterations in pure LCIS and in synchronous LCIS and ILC using targeted massively parallel sequencing. DNA samples extracted from microdissected LCIS, ILC and matched normal breast tissue or peripheral blood from 30 patients were subjected to massively parallel sequencing targeting all exons of 273 genes, including the genes most frequently mutated in breast cancer and DNA repair-related genes. Single nucleotide variants and insertions and deletions were identified using state-of-the-art bioinformatics approaches. The constellation of somatic mutations found in LCIS (n = 34) and ILC (n = 21) were similar, with the most frequently mutated genes being CDH1 (56% and 66%, respectively), PIK3CA (41% and 52%, respectively) and CBFB (12% and 19%, respectively). Among 19 LCIS and ILC synchronous pairs, 14 (74%) had at least one identical mutation in common, including identical PIK3CA and CDH1 mutations. Paired analysis of independent foci of LCIS from 3 breasts revealed at least one common mutation in each of the 3 pairs (CDH1, PIK3CA, CBFB and PKHD1L1). LCIS and ILC have a similar repertoire of somatic mutations, with PIK3CA and CDH1 being the most frequently mutated genes. The presence of identical mutations between LCIS-LCIS and LCIS-ILC pairs demonstrates that LCIS is a clonal neoplastic lesion, and provides additional evidence that at least some LCIS are non-obligate precursors of ILC. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  15. Somatic Genomics and Clinical Features of Lung Adenocarcinoma: A Retrospective Study.

    Directory of Open Access Journals (Sweden)

    Jianxin Shi

    2016-12-01

    Full Text Available Lung adenocarcinoma (LUAD is the most common histologic subtype of lung cancer and has a high risk of distant metastasis at every disease stage. We aimed to characterize the genomic landscape of LUAD and identify mutation signatures associated with tumor progression.We performed an integrative genomic analysis, incorporating whole exome sequencing (WES, determination of DNA copy number and DNA methylation, and transcriptome sequencing for 101 LUAD samples from the Environment And Genetics in Lung cancer Etiology (EAGLE study. We detected driver genes by testing whether the nonsynonymous mutation rate was significantly higher than the background mutation rate and replicated our findings in public datasets with 724 samples. We performed subclonality analysis for mutations based on mutant allele data and copy number alteration data. We also tested the association between mutation signatures and clinical outcomes, including distant metastasis, survival, and tumor grade. We identified and replicated two novel candidate driver genes, POU class 4 homeobox 2 (POU4F2 (mutated in 9 [8.9%] samples and ZKSCAN1 (mutated in 6 [5.9%] samples, and characterized their major deleterious mutations. ZKSCAN1 was part of a mutually exclusive gene set that included the RTK/RAS/RAF pathway genes BRAF, EGFR, KRAS, MET, and NF1, indicating an important driver role for this gene. Moreover, we observed strong associations between methylation in specific genomic regions and somatic mutation patterns. In the tumor evolution analysis, four driver genes had a significantly lower fraction of subclonal mutations (FSM, including TP53 (p = 0.007, KEAP1 (p = 0.012, STK11 (p = 0.0076, and EGFR (p = 0.0078, suggesting a tumor initiation role for these genes. Subclonal mutations were significantly enriched in APOBEC-related signatures (p < 2.5×10-50. The total number of somatic mutations (p = 0.0039 and the fraction of transitions (p = 5.5×10-4 were associated with increased risk of

  16. Detection of somatic mosaicism in DMD using computer-assisted laser densitometry

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, J.E.; Allingham-Hawkins, D.J.; MacKenzie, J. [Hospital for Sick Children, Toronto (Canada)] [and others

    1994-09-01

    Approximately two-thirds of Duchenne muscular dystrophy (DMD) patients have a deletion in the dystrophin gene located at Xp21.1. Two PCR-based multiplex systems have been developed which detect 98% of deletions in affected males. Diagnosis of carrier females requires densitometry of PCR products following gel electrophoresis to calculate dosage of specific exons. We have developed a system in which fluorescently labelled PCR products are analysed using a GENESCANNER automated fragment analyser (ABI). Dosage is determined using computer-assisted laser densitometry (CALD). Recently, we diagnosed somatic mosaicism in the mother of an affected boy using this method. PCR analysis showed that the patient had a deletion that included exons 47-51 of his dystrophin gene. CALD analysis on the patient`s 36-year-old mother revealed a 29-34% reduction in the intensity of the bands corresponding to the deleted region of the gene rather than the 50% reduction normally seen in carrier females. A skin biopsy was obtain and monoclonal fibroblast colonies were tested by CALD for the deletion. Four of the twenty colonies screened were found to be deleted while the remaining colonies had two intact copies of the gene. We conclude that this patient is a somatic mosaic for DMD and that the mutation was the result of a post-zygotic event. This is the only case of somatic mosaicism detected among 800 women from 400 DMD families tested using CALD in our laboratory. At least one other case of possible somatic mosaicism has been reported but not confirmed. Germinal mosaicism is thought to occur in approximately 10% of mothers of sporadic DMD patients. Our findings indicate that somatic mosaicism is a much rarer condition among DMD carriers, thus suggesting that mitotic mutations in the dystrophin gene are more likely to occur later in embryogenesis after differentiation of the germline.

  17. The dual nature of mismatch repair as antimutator and mutator: for better or for worse

    Directory of Open Access Journals (Sweden)

    Sara Thornby Bak

    2014-08-01

    Full Text Available DNA is constantly under attack by a number of both exogenous and endogenous agents that challenge its integrity. Among the mechanisms that have evolved to counteract this deleterious action, mismatch repair (MMR has specialized in removing DNA biosynthetic errors that occur when replicating the genome. Malfunction or inactivation of this system results in an increase in spontaneous mutability and a strong predisposition to tumor development. Besides this key corrective role, MMR proteins are involved in other pathways of DNA metabolism such as mitotic and meiotic recombination and processing of oxidative damage. Surprisingly, MMR is also required for certain mutagenic processes. The mutagenic MMR has beneficial consequences contributing to the generation of a vast repertoire of antibodies through class switch recombination and somatic hypermutation processes. However, this non-canonical mutagenic MMR also has detrimental effects; it promotes repeat expansions associated with neuromuscular and neurodegenerative diseases and may contribute to cancer/disease-related aberrant mutations and translocations. The reaction responsible for replication error correction has been the most thoroughly studied and it is the subject to numerous reviews. This review describes briefly the biochemistry of MMR and focuses primarily on the non-canonical MMR activities described in mammals as well as emerging research implicating interplay of MMR and chromatin.

  18. piggyBac transposon somatic mutagenesis with an activated reporter and tracker (PB-SMART for genetic screens in mice.

    Directory of Open Access Journals (Sweden)

    Sean F Landrette

    Full Text Available Somatic forward genetic screens have the power to interrogate thousands of genes in a single animal. Retroviral and transposon mutagenesis systems in mice have been designed and deployed in somatic tissues for surveying hematopoietic and solid tumor formation. In the context of cancer, the ability to visually mark mutant cells would present tremendous advantages for identifying tumor formation, monitoring tumor growth over time, and tracking tumor infiltrations and metastases into wild-type tissues. Furthermore, locating mutant clones is a prerequisite for screening and analyzing most other somatic phenotypes. For this purpose, we developed a system using the piggyBac (PB transposon for somatic mutagenesis with an activated reporter and tracker, called PB-SMART. The PB-SMART mouse genetic screening system can simultaneously induce somatic mutations and mark mutated cells using bioluminescence or fluorescence. The marking of mutant cells enable analyses that are not possible with current somatic mutagenesis systems, such as tracking cell proliferation and tumor growth, detecting tumor cell infiltrations, and reporting tissue mutagenesis levels by a simple ex vivo visual readout. We demonstrate that PB-SMART is highly mutagenic, capable of tumor induction with low copy transposons, which facilitates the mapping and identification of causative insertions. We further integrated a conditional transposase with the PB-SMART system, permitting tissue-specific mutagenesis with a single cross to any available Cre line. Targeting the germline, the system could also be used to conduct F1 screens. With these features, PB-SMART provides an integrated platform for individual investigators to harness the power of somatic mutagenesis and phenotypic screens to decipher the genetic basis of mammalian biology and disease.

  19. The Somatic Complaints List: Validation of a self-report questionnaire assessing somatic complaints in children

    NARCIS (Netherlands)

    Jellesma, F. C.; Rieffe, C.J.; Meerum Terwogt, M.

    2007-01-01

    Objective: To evaluate the Somatic Complaint List (SCL) in children. Method: At T1, 365 fourth and 352 fifth graders completed the SCL, the Children's Somatization Inventory (CSI-C), and the Mood Questionnaire. Parents (n=564) completed the parental form of the CSI-C (CSI-P). Six months later, the

  20. Mutational effects of space flight on Zea mays seeds

    Science.gov (United States)

    Mei, M.; Qiu, Y.; He, Y.; Bucker, H.; Yang, C. H.

    1994-01-01

    The growth and development of more than 500 Zea mays seeds flown on Long Duration Exposure Facility (LDEF) were studied. Somatic mutations, including white-yellow stripes on leaves, dwarfing, change of leaf sheath color or seedling color were observed in plants developed from these seeds. When the frequency of white-yellow formation was used as the endpoint and compared with data from ground based studies, the dose to which maize seeds might be exposed during the flight was estimated to be equivalent to 635 cGy of gamma rays. Seeds from one particular holder gave a high mutation frequency and a wide mutation spectrum. White-yellow stripes on leaves were also found in some of the inbred progenies from plants displayed somatic mutation. Electron microscopy studies showed that the damage of chloroplast development in the white-yellow stripe on leaves was similar between seeds flown on LDEF and that irradiated by accelerated heavy ions on ground.

  1. Prospects for cellular mutational assays in human populations

    International Nuclear Information System (INIS)

    Mendelsohn, M.L.

    1985-01-01

    Practical, sensitive, effective, human cellular assays for detecting somatic and germinal mutations would have great value in environmental mutagenesis and carcinogenesis. When available, such assays should allow us to fill the void between human mutagenicity and the data that exist from short-term tests and from mutagenicity in other species. We will be able to validate the role of somatic mutations in carcinogenesis, to identify environmental factors that affect human germ cells, to integrate the effects of complex mixtures and the environment in the human subject, and to identify people who are hypersusceptible to genetic injury. Human cellular mutational assays, particularly when combined with cytogenetic and heritable mutational tests, promise to play pivotal roles in estimating the risk from low-dose radiation and chemical exposures. These combined methods avoid extrapolations of dose and from species to species, and may be sensitive enough and credible enough to permit politically, socially and scientifically acceptable risk management. 16 references

  2. Recurrent PTPRB and PLCG1 mutations in angiosarcoma.

    Science.gov (United States)

    Behjati, Sam; Tarpey, Patrick S; Sheldon, Helen; Martincorena, Inigo; Van Loo, Peter; Gundem, Gunes; Wedge, David C; Ramakrishna, Manasa; Cooke, Susanna L; Pillay, Nischalan; Vollan, Hans Kristian M; Papaemmanuil, Elli; Koss, Hans; Bunney, Tom D; Hardy, Claire; Joseph, Olivia R; Martin, Sancha; Mudie, Laura; Butler, Adam; Teague, Jon W; Patil, Meena; Steers, Graham; Cao, Yu; Gumbs, Curtis; Ingram, Davis; Lazar, Alexander J; Little, Latasha; Mahadeshwar, Harshad; Protopopov, Alexei; Al Sannaa, Ghadah A; Seth, Sahil; Song, Xingzhi; Tang, Jiabin; Zhang, Jianhua; Ravi, Vinod; Torres, Keila E; Khatri, Bhavisha; Halai, Dina; Roxanis, Ioannis; Baumhoer, Daniel; Tirabosco, Roberto; Amary, M Fernanda; Boshoff, Chris; McDermott, Ultan; Katan, Matilda; Stratton, Michael R; Futreal, P Andrew; Flanagan, Adrienne M; Harris, Adrian; Campbell, Peter J

    2014-04-01

    Angiosarcoma is an aggressive malignancy that arises spontaneously or secondarily to ionizing radiation or chronic lymphoedema. Previous work has identified aberrant angiogenesis, including occasional somatic mutations in angiogenesis signaling genes, as a key driver of angiosarcoma. Here we employed whole-genome, whole-exome and targeted sequencing to study the somatic changes underpinning primary and secondary angiosarcoma. We identified recurrent mutations in two genes, PTPRB and PLCG1, which are intimately linked to angiogenesis. The endothelial phosphatase PTPRB, a negative regulator of vascular growth factor tyrosine kinases, harbored predominantly truncating mutations in 10 of 39 tumors (26%). PLCG1, a signal transducer of tyrosine kinases, encoded a recurrent, likely activating p.Arg707Gln missense variant in 3 of 34 cases (9%). Overall, 15 of 39 tumors (38%) harbored at least one driver mutation in angiogenesis signaling genes. Our findings inform and reinforce current therapeutic efforts to target angiogenesis signaling in angiosarcoma.

  3. Is somatic comorbidity associated with more somatic symptoms, mental distress, or unhealthy lifestyle in elderly cancer survivors?

    Science.gov (United States)

    Grov, Ellen Karine; Fosså, Sophie D; Dahl, Alv A

    2009-06-01

    The associations of lifestyle factors, somatic symptoms, mental distress, and somatic comorbidity in elderly cancer survivors have not been well studied. This study examines these associations among elderly cancer survivors (age >or=65 years) in a population-based sample. A cross-sectional comparative study of Norwegian elderly cancer survivors. Combining information from The Norwegian Cancer Registry, and by self-reporting, 972 elderly cancer survivors were identified, of whom 632 (65%) had somatic comorbidity and 340 did not. Elderly cancer survivors with somatic comorbidity had significantly higher BMI, more performed minimal physical activity, had more somatic symptoms, used more medication, and had more frequently seen a medical doctor than survivors without somatic comorbidity. In multivariable analyses, unhealthy lifestyle and higher somatic symptoms scores were significantly associated with cancer cases with somatic comorbidity. In univariate analyses those with somatic comorbidity were significantly older, had lower levels of education, higher proportions of BMI >or= 30, less physical activity, poorer self-rated health, higher somatic symptoms score, more mental distress, had more frequently seen a medical doctor last year, and more frequently used daily medication. Our outcome measures of lifestyle, somatic symptoms and mental distress were all significantly associated with somatic comorbidity in elderly cancer survivors, however only lifestyle and somatic symptoms were significant in multivariable analyses. In elderly cancer survivors not only cancer, but also somatic comorbidity, deserve attention. Such comorbidity is associated with unhealthy lifestyles, more somatic symptoms and mental distress which should be evaluated and eventually treated.

  4. Whole-exome sequencing of muscle-invasive bladder cancer identifies recurrent mutations of UNC5C and prognostic importance of DNA repair gene mutations on survival.

    Science.gov (United States)

    Yap, Kai Lee; Kiyotani, Kazuma; Tamura, Kenji; Antic, Tatjana; Jang, Miran; Montoya, Magdeline; Campanile, Alexa; Yew, Poh Yin; Ganshert, Cory; Fujioka, Tomoaki; Steinberg, Gary D; O'Donnell, Peter H; Nakamura, Yusuke

    2014-12-15

    Because of suboptimal outcomes in muscle-invasive bladder cancer even with multimodality therapy, determination of potential genetic drivers offers the possibility of improving therapeutic approaches and discovering novel prognostic indicators. Using pTN staging, we case-matched 81 patients with resected ≥pT2 bladder cancers for whom perioperative chemotherapy use and disease recurrence status were known. Whole-exome sequencing was conducted in 43 cases to identify recurrent somatic mutations and targeted sequencing of 10 genes selected from the initial screening in an additional 38 cases was completed. Mutational profiles along with clinicopathologic information were correlated with recurrence-free survival (RFS) in the patients. We identified recurrent novel somatic mutations in the gene UNC5C (9.9%), in addition to TP53 (40.7%), KDM6A (21.0%), and TSC1 (12.3%). Patients who were carriers of somatic mutations in DNA repair genes (one or more of ATM, ERCC2, FANCD2, PALB2, BRCA1, or BRCA2) had a higher overall number of somatic mutations (P = 0.011). Importantly, after a median follow-up of 40.4 months, carriers of somatic mutations (n = 25) in any of these six DNA repair genes had significantly enhanced RFS compared with noncarriers [median, 32.4 vs. 14.8 months; hazard ratio of 0.46, 95% confidence interval (CI), 0.22-0.98; P = 0.0435], after adjustment for pathologic pTN staging and independent of adjuvant chemotherapy usage. Better prognostic outcomes of individuals carrying somatic mutations in DNA repair genes suggest these mutations as favorable prognostic events in muscle-invasive bladder cancer. Additional mechanistic investigation into the previously undiscovered role of UNC5C in bladder cancer is warranted. ©2014 American Association for Cancer Research.

  5. Regulation of Na+ channel inactivation by the DIII and DIV voltage-sensing domains.

    Science.gov (United States)

    Hsu, Eric J; Zhu, Wandi; Schubert, Angela R; Voelker, Taylor; Varga, Zoltan; Silva, Jonathan R

    2017-03-06

    Functional eukaryotic voltage-gated Na + (Na V ) channels comprise four domains (DI-DIV), each containing six membrane-spanning segments (S1-S6). Voltage sensing is accomplished by the first four membrane-spanning segments (S1-S4), which together form a voltage-sensing domain (VSD). A critical Na V channel gating process, inactivation, has previously been linked to activation of the VSDs in DIII and DIV. Here, we probe this interaction by using voltage-clamp fluorometry to observe VSD kinetics in the presence of mutations at locations that have been shown to impair Na V channel inactivation. These locations include the DIII-DIV linker, the DIII S4-S5 linker, and the DIV S4-S5 linker. Our results show that, within the 10-ms timeframe of fast inactivation, the DIV-VSD is the primary regulator of inactivation. However, after longer 100-ms pulses, the DIII-DIV linker slows DIII-VSD deactivation, and the rate of DIII deactivation correlates strongly with the rate of recovery from inactivation. Our results imply that, over the course of an action potential, DIV-VSDs regulate the onset of fast inactivation while DIII-VSDs determine its recovery. © 2017 Hsu et al.

  6. Somatization: a perspective from self psychology.

    Science.gov (United States)

    Rodin, G M

    1991-01-01

    Somatization is a complex phenomenon that occurs in many forms and diverse settings. It is not necessarily pathological and may be found in a variety of psychiatric disorders. Much of the psychiatric literature has focused on patients with conversion disorders and hypochondriasis. Psychoanalytic theories regarding such conditions were largely based upon concepts of drive, conflict, and defense. The perspective from self psychology, with its emphasis on subjective experience and the sense of self, may further enhance the psychoanalytic understanding of somatization. Individuals with disturbances in the stability and organization of the self may present with somatic symptoms and disturbances in emotional awareness. Somatization in such cases may be the experiential manifestation of a disturbance in the cohesion of the self and/or may result from defensive operations to ward off affect. The latter may be prominent when affective arousal triggers the psychological threat of fragmentation. Somatization may diminish in such individuals when a self-object relationship is formed that bolsters and consolidates the sense of self. The integration of affect into ongoing subjective experience may also be an important aspect of psychoanalytic treatment in such patients.

  7. Hypochondriacal concerns and somatization in panic disorder.

    Science.gov (United States)

    Furer, P; Walker, J R; Chartier, M J; Stein, M B

    1997-01-01

    To clarify the relationship between panic disorder and the symptoms of hypochondriasis and somatization, we evaluated these symptoms and diagnoses in patients attending an Anxiety Disorders Clinic. Structured clinical interviews, self-report measures, and symptom diaries were used to assess 21 patients with panic disorder, 23 patients with social phobia, and 22 control subjects with no psychiatric disorders. Ten of the patients with panic disorder (48%) also met DSM-IV criteria for hypochondriasis, whereas only one of the patients with social phobia and none of the healthy control subjects met the criteria for this diagnosis. None of the participants met DSM-IV criteria for somatization disorder, even though both anxiety groups reported high levels of somatic symptoms. The panic disorder group reported higher levels of fear about illness and disease conviction and endorsed more somatic symptoms than did the other groups. A higher proportion of panic disorder patients reported previously diagnosed medical conditions (48%) as compared with patients with social phobia (17%) or healthy control subjects (14%). The panic disorder patients with DSM-IV hypochondriasis obtained higher scores on measures of hypochondriacal concerns, somatization, blood-injury phobia, and general anxiety and distress than did the panic disorder patients without hypochondriasis. The results suggest a strong association between panic disorder and hypochondriasis.

  8. Cryopreservation of Arachis pintoi (leguminosae) somatic embryos.

    Science.gov (United States)

    Rey, H Y; Faloci, M; Medina, R; Dolce, N; Engelmann, F; Mroginski, L

    2013-01-01

    In this study, we successfully cryopreserved cotyledonary somatic embryos of diploid and triploid Arachis pintoi cytotypes using the encapsulation-dehydration technique. The highest survival rates were obtained when somatic embryos were encapsulated in calcium alginate beads and precultured in agitated (80 rpm) liquid establishment medium (EM) with daily increasing sucrose concentration (0.50, 0.75, and 1.0 M). The encapsulated somatic embryos were then dehydrated with silica gel for 5 h to 20% moisture content (fresh weight basis) and cooled either rapidly (direct immersion in liquid nitrogen, LN) or slowly (1 degree C per min from 25 degree C to -30 degree C followed by immersion in LN). Beads were kept in LN for a minimum of 1 h and then were rapidly rewarmed in a 30 degree C water-bath for 2 min. Finally, encapsulated somatic embryos were post-cultured in agitated (80 rpm) liquid EM with daily decreasing sucrose concentration (0.75 and 0.5 M) and transferred to solidified EM. Using this protocol, we obtained 26% and 30% plant regeneration from cryopreserved somatic embryos of diploid and triploid cytotypes. No morphological abnormalities were observed in any of the plants regenerated from cryopreserved embryos and their genetic stability was confirmed with 10 isozyme systems and nine RAPD profiles.

  9. The Eag domain regulates the voltage-dependent inactivation of rat Eag1 K+ channels.

    Directory of Open Access Journals (Sweden)

    Ting-Feng Lin

    Full Text Available Eag (Kv10 and Erg (Kv11 belong to two distinct subfamilies of the ether-à-go-go K+ channel family (KCNH. While Erg channels are characterized by an inward-rectifying current-voltage relationship that results from a C-type inactivation, mammalian Eag channels display little or no voltage-dependent inactivation. Although the amino (N-terminal region such as the eag domain is not required for the C-type inactivation of Erg channels, an N-terminal deletion in mouse Eag1 has been shown to produce a voltage-dependent inactivation. To further discern the role of the eag domain in the inactivation of Eag1 channels, we generated N-terminal chimeras between rat Eag (rEag1 and human Erg (hERG1 channels that involved swapping the eag domain alone or the complete cytoplasmic N-terminal region. Functional analyses indicated that introduction of the homologous hERG1 eag domain led to both a fast phase and a slow phase of channel inactivation in the rEag1 chimeras. By contrast, the inactivation features were retained in the reverse hERG1 chimeras. Furthermore, an eag domain-lacking rEag1 deletion mutant also showed the fast phase of inactivation that was notably attenuated upon co-expression with the rEag1 eag domain fragment, but not with the hERG1 eag domain fragment. Additionally, we have identified a point mutation in the S4-S5 linker region of rEag1 that resulted in a similar inactivation phenotype. Biophysical analyses of these mutant constructs suggested that the inactivation gating of rEag1 was distinctly different from that of hERG1. Overall, our findings are consistent with the notion that the eag domain plays a critical role in regulating the inactivation gating of rEag1. We propose that the eag domain may destabilize or mask an inherent voltage-dependent inactivation of rEag1 K+ channels.

  10. Mechanisms of mutations in myeloproliferative neoplasms.

    Science.gov (United States)

    Levine, Ross L

    2009-12-01

    In recent years, a series of studies have provided genetic insight into the pathogenesis of myeloproliferative neoplasms (MPNs). It is now known that JAK2V617F mutations are present in 90% of patients with polycythaemia vera (PV), 60% of patients with essential thrombocytosis (ET) and 50% of patients with myelofibrosis (MF). Despite the high prevalence of JAK2V617F mutations in these three myeloid malignancies, several questions remain. For example, how does one mutation contribute to the pathogenesis of three clinically distinct diseases, and how do some patients develop these diseases in the absence of a JAK2V617F mutation? Single nucleotide polymorphisms at various loci and somatic mutations, such as those in MPLW515L/K, TET2 and in exon 12 of JAK2, may also contribute to the pathogenesis of these MPNs. There are likely additional germline and somatic genetic factors important to the MPN phenotype. Additional studies of large MPN and control cohorts with new techniques will help identify these factors.

  11. The IARC TP53 mutation database: a resource for studying the significance of TP53 mutations in human cancers

    Directory of Open Access Journals (Sweden)

    Magali Olivier

    2007-02-01

    Full Text Available

    The tumor suppressor gene TP53 is frequently inactivated by gene mutations in many types of human sporadic cancers, and inherited TP53 mutations predispose to a wide spectrum of early-onset tumors (Li-Fraumeni et Li-Fraumenilike Syndromes. All TP53 gene variations (somatic and germline mutations, as well as polymorphisms that are reported in the scientific literature or in SNP databases are compiled in the IARC TP53 Database. This database provides structured data and analysis tools to study mutation patterns in human cancers and cell-lines and to investigate the clinical impact of mutations. It contains annotations related to the clinical and pathological characteristics of tumors, as well as the demographics and carcinogen exposure of patients. The IARC TP53 web site (http://www-p53.iarc.fr/ provides a search interface for the core database and includes a comprehensive user guide, a slideshow on TP53 mutations in human cancer, protocols and references for sequencing TP53 gene, and links to relevant publications and bioinformatics databases. The database interface allows download of entire data sets and propose various tools for the selection, analysis and downloads of specific sets of data according to user's query.

    Recently, new annotations on the functional properties of mutant p53 proteins have been integrated in this database. Indeed, the most frequent TP53 alterations observed in cancers (75% are missense mutations that result in the production of a mutant protein that differ from the wildtype by one single amino-acid. The characterization of the biological activities of these mutant proteins is thus very important. Over the last ten years, a great amount of systematic data has been generated from experimental assays performed in

  12. Autosomal dominant polycystic kidney disease caused by somatic and germline mosaicism.

    Science.gov (United States)

    Tan, A Y; Blumenfeld, J; Michaeel, A; Donahue, S; Bobb, W; Parker, T; Levine, D; Rennert, H

    2015-04-01

    Autosomal dominant polycystic kidney disease (ADPKD) is a heterogeneous genetic disorder caused by loss of function mutations of PKD1 or PKD2 genes. Although PKD1 is highly polymorphic and the new mutation rate is relatively high, the role of mosaicism is incompletely defined. Herein, we describe the molecular analysis of ADPKD in a 19-year-old female proband and her father. The proband had a PKD1 truncation mutation c.10745dupC (p.Val3584ArgfsX43), which was absent in paternal peripheral blood lymphocytes (PBL). However, very low quantities of this mutation were detected in the father's sperm DNA, but not in DNA from his buccal cells or urine sediment. Next generation sequencing (NGS) analysis determined the level of this mutation in the father's PBL, buccal cells and sperm to be ∼3%, 4.5% and 10%, respectively, consistent with somatic and germline mosaicism. The PKD1 mutation in ∼10% of her father's sperm indicates that it probably occurred early in embryogenesis. In ADPKD cases where a de novo mutation is suspected because of negative PKD gene testing of PBL, additional evaluation with more sensitive methods (e.g. NGS) of the proband PBL and paternal sperm can enhance detection of mosaicism and facilitate genetic counseling. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Cellular Mechanisms of Somatic Stem Cell Aging

    Science.gov (United States)

    Jung, Yunjoon

    2014-01-01

    Tissue homeostasis and regenerative capacity rely on rare populations of somatic stem cells endowed with the potential to self-renew and differentiate. During aging, many tissues show a decline in regenerative potential coupled with a loss of stem cell function. Cells including somatic stem cells have evolved a series of checks and balances to sense and repair cellular damage to maximize tissue function. However, during aging the mechanisms that protect normal cell function begin to fail. In this review, we will discuss how common cellular mechanisms that maintain tissue fidelity and organismal lifespan impact somatic stem cell function. We will highlight context-dependent changes and commonalities that define aging, by focusing on three age-sensitive stem cell compartments: blood, neural, and muscle. Understanding the interaction between extrinsic regulators and intrinsic effectors that operate within different stem cell compartments is likely to have important implications for identifying strategies to improve health span and treat age-related degenerative diseases. PMID:24439814

  14. Tumor-specific mutations in low-frequency genes affect their functional properties

    NARCIS (Netherlands)

    L. Erdem-Eraslan (Lale); D. Heijsman (Daphne); M. De Wit (Maurice); A.E. Kremer (Andreas); A. Sacchetti (Andrea); P.J. van der Spek (Peter); P.A.E. Sillevis Smitt (Peter); P.J. French (Pim)

    2015-01-01

    textabstractCausal genetic changes in oligodendrogliomas (OD) with 1p/19q co-deletion include mutations in IDH1, IDH2, CIC, FUBP1, TERT promoter and NOTCH1. However, it is generally assumed that more somatic mutations are required for tumorigenesis. This study aimed to establish whether genes

  15. Somatic seeds of Plantago asiatica L.

    Directory of Open Access Journals (Sweden)

    Emilia Andrzejewska-Golec

    2011-01-01

    Full Text Available Somatic seeds of Plantago asiatica L. were produced for the first time. Shoot-tips isolated from in vitro obtained 4-week shoots were encapsulated using sodium alginate and calcium chloride. Capsules with or without sucrose and with and without cytokinin - indole-3-butyric acid (IBA were used. Sucrose presence in capsules very distinctly influences somatic seeds of Plantago asiatica germination and their conversion into plants. However, addition of IBA to capsules has not clear influence on the ability of plant regrowth. Plantlets transplanted to soil grew to phenotypically normal plants.

  16. Human somatic cell nuclear transfer and cloning.

    Science.gov (United States)

    2012-10-01

    This document presents arguments that conclude that it is unethical to use somatic cell nuclear transfer (SCNT) for infertility treatment due to concerns about safety; the unknown impact of SCNT on children, families, and society; and the availability of other ethically acceptable means of assisted reproduction. This document replaces the ASRM Ethics Committee report titled, "Human somatic cell nuclear transfer (cloning)," last published in Fertil Steril 2000;74:873-6. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  17. The Role of Polymerase Gamma Mutations in Breast Tumorigenesis

    Science.gov (United States)

    2011-01-01

    481–484. [PubMed: 16020738] 47. Alonso A, Martin P, Albarran C, Aquilera B, Garcia O, Guzman A, et al. Detection of somatic mutations in the...Hum. Genet 2005;76:1081–1086. [PubMed: 15877282] 30. Spinazzola A, Viscomi C, Fernandez -Vizarra E, Carrara F, D’Adamo P, Calvo S, et al. MPV17 encodes

  18. Somatic tinnitus prevalence and treatment with tinnitus retraining therapy.

    Science.gov (United States)

    Ostermann, K; Lurquin, P; Horoi, M; Cotton, P; Hervé, V; Thill, M P

    2016-01-01

    Somatic tinnitus originates from increased activity of the dorsal cochlear nucleus, a cross-point between the somatic and auditory systems. Its activity can be modified by auditory stimulation or somatic system manipulation. Thus, sound enrichment and white noise stimulation might decrease tinnitus and associated somatic symptoms. The present uncontrolled study sought to determine somatic tinnitus prevalence among tinnitus sufferers, and to investigate whether sound therapy with counselling (tinnitus retraining therapy; TRT) may decrease tinnitus-associated somatic symptoms. To determine somatic tinnitus prevalence, 70 patients following the TRT protocol completed the Jastreboff Structured Interview (JSI) with additional questions regarding the presence and type of somatic symptoms. Among 21 somatic tinnitus patients, we further investigated the effects of TRT on tinnitus-associated facial dysesthesia. Before and after three months of TRT, tinnitus severity was evaluated using the Tinnitus Handicap Inventory (THI), and facial dysesthesia was assessed with an extended JSI-based questionnaire. Among the evaluated tinnitus patients, 56% presented somatic tinnitus-including 51% with facial dysesthesia, 36% who could modulate tinnitus by head and neck movements, and 13% with both conditions. Self-evaluation indicated that TRT significantly improved tinnitus and facial dysesthesia in 76% of patients. Three months of TRT led to a 50% decrease in mean THI and JSI scores regarding facial dysesthesia. Somatic tinnitus is a frequent and underestimated condition. We suggest an extension of the JSI, including specific questions regarding somatic tinnitus. TRT significantly improved tinnitus and accompanying facial dysesthesia, and could be a useful somatic tinnitus treatment.

  19. Human somatic, germinal and heritable mutagenicity

    International Nuclear Information System (INIS)

    Mendelsohn, M.L.

    1987-05-01

    This report deals with the general process of variant formation rather than with the consequences of a specific variant being present. It focusses on mutational mechanisms, mutagens, and the method for detecting de novo mutants and estimating mutation rate. It is to human genetics much like disease causation and prevention medicine are to medicine as a whole. The word ''mutagenicity'' is used in the title and throughout the text to connote the causation of all classes of genetic damage. Mutagenicity and the corresponding words mutation, mutagen and mutagenesis can have multiple meaning, sometimes relating to gene mutation, sometimes to heritable mutation, and somtimes to all types of genetic damage. 38 refs., 1 tab

  20. Normal X-inactivation mosaicism in corneas of heterozygous FlnaDilp2/+ female mice--a model of human Filamin A (FLNA diseases

    Directory of Open Access Journals (Sweden)

    Douvaras Panagiotis

    2012-02-01

    Full Text Available Abstract Background Some abnormalities of mouse corneal epithelial maintenance can be identified by the atypical mosaic patterns they produce in X-chromosome inactivation mosaics and chimeras. Human FLNA/+ females, heterozygous for X-linked, filamin A gene (FLNA mutations, display a range of disorders and X-inactivation mosaicism is sometimes quantitatively unbalanced. FlnaDilp2/+ mice, heterozygous for an X-linked filamin A (Flna nonsense mutation have variable eye, skeletal and other abnormalities, but X-inactivation mosaicism has not been investigated. The aim of this study was to determine whether X-inactivation mosaicism in the corneal epithelia of FlnaDilp2/+ mice was affected in any way that might predict abnormal corneal epithelial maintenance. Results X-chromosome inactivation mosaicism was studied in the corneal epithelium and a control tissue (liver of FlnaDilp2/+ and wild-type (WT female X-inactivation mosaics, hemizygous for the X-linked, LacZ reporter H253 transgene, using β-galactosidase histochemical staining. The corneal epithelia of FlnaDilp2/+ and WT X-inactivation mosaics showed similar radial, striped patterns, implying epithelial cell movement was not disrupted in FlnaDilp2/+ corneas. Corrected stripe numbers declined with age overall (but not significantly for either genotype individually, consistent with previous reports suggesting an age-related reduction in stem cell function. Corrected stripe numbers were not reduced in FlnaDilp2/+ compared with WT X-inactivation mosaics and mosaicism was not significantly more unbalanced in the corneal epithelia or livers of FlnaDilp2/+ than wild-type Flna+/+ X-inactivation mosaics. Conclusions Mosaic analysis identified no major effect of the mouse FlnaDilp2 mutation on corneal epithelial maintenance or the balance of X-inactivation mosaicism in the corneal epithelium or liver.

  1. Transfer of bacterial blight resistance from Oryza meyeriana to O.Sativa L.by asymmetric somatic hybridization

    Institute of Scientific and Technical Information of China (English)

    ZHU Yongsheng; CHEN Baotang; YU Shunwu; ZHANG Duanpin; ZHANG Xueqin; YAN Qiusheng

    2004-01-01

    Asymmetric somatic hybrid plants were produced between cultivated rice (Oryza sativa L.) and wild species [O. Meyeriana (Zoll. etMor, exSteud.)] with high resistance to rice bacterial blight. X-ray-irradiated protoplasts of the wild species were used as donor and chemically fused with iodoacetamide-inactivated protoplasts of rice cv. 02428to produce hybrids. Seventy-two plants were regenerated from 623 calli based on metabolic complementation. The morphological characters of the plants closely resembled that of the rice. Simple sequence repeats were employed to identify their hybridity. Cytological analysis of root-tips revealed that their chromosome number varied in the range of 27-38. The somatic hybrids were inoculated with strains of Xanthamonas oryzae pv. Oryzae at adult growth stage and demonstrated the resistance to bacterial blight introgression from the O. Meyeriana.

  2. Inhibition of Retinoblastoma Protein Inactivation

    Science.gov (United States)

    2017-11-01

    CONTRACT NUMBER Inhibition of Retinoblastoma Protein Inactivation 5b. GRANT NUMBER W81XWH-14-1-0329 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Seth M...confirmed 108 compounds as giving a dose-response curve with at least 30% inhibition at 10 µM. The flowchart of hit progression is shown on the...Cancer Research Program under Award No. W81XWH-14-1-0329 to S.M.R. Opinions, interpretations, conclusions, and recommendations are those of the author

  3. Impaired action potential initiation in GABAergic interneurons causes hyperexcitable networks in an epileptic mouse model carrying a human Na(V)1.1 mutation.

    Science.gov (United States)

    Hedrich, Ulrike B S; Liautard, Camille; Kirschenbaum, Daniel; Pofahl, Martin; Lavigne, Jennifer; Liu, Yuanyuan; Theiss, Stephan; Slotta, Johannes; Escayg, Andrew; Dihné, Marcel; Beck, Heinz; Mantegazza, Massimo; Lerche, Holger

    2014-11-05

    Mutations in SCN1A and other ion channel genes can cause different epileptic phenotypes, but the precise mechanisms underlying the development of hyperexcitable networks are largely unknown. Here, we present a multisystem analysis of an SCN1A mouse model carrying the NaV1.1-R1648H mutation, which causes febrile seizures and epilepsy in humans. We found a ubiquitous hypoexcitability of interneurons in thalamus, cortex, and hippocampus, without detectable changes in excitatory neurons. Interestingly, somatic Na(+) channels in interneurons and persistent Na(+) currents were not significantly changed. Instead, the key mechanism of interneuron dysfunction was a deficit of action potential initiation at the axon initial segment that was identified by analyzing action potential firing. This deficit increased with the duration of firing periods, suggesting that increased slow inactivation, as recorded for recombinant mutated channels, could play an important role. The deficit in interneuron firing caused reduced action potential-driven inhibition of excitatory neurons as revealed by less frequent spontaneous but not miniature IPSCs. Multiple approaches indicated increased spontaneous thalamocortical and hippocampal network activity in mutant mice, as follows: (1) more synchronous and higher-frequency firing was recorded in primary neuronal cultures plated on multielectrode arrays; (2) thalamocortical slices examined by field potential recordings revealed spontaneous activities and pathological high-frequency oscillations; and (3) multineuron Ca(2+) imaging in hippocampal slices showed increased spontaneous neuronal activity. Thus, an interneuron-specific generalized defect in action potential initiation causes multisystem disinhibition and network hyperexcitability, which can well explain the occurrence of seizures in the studied mouse model and in patients carrying this mutation. Copyright © 2014 the authors 0270-6474/14/3414874-16$15.00/0.

  4. Genetic and somatic effects in animals maintained on tritiated water

    International Nuclear Information System (INIS)

    Carsten, A.L.; Commerford, S.L.; Cronkite, E.P.; Brooks, A.

    1982-01-01

    Somatic and genetic effects of the continuous ingestion of tritiated water (HTO) at concentrations of 0.3, 1.0 and 3.0 μCi/ml were investigated in mice of the Hale-Stoner-Brookhaven strain. At these levels, there was no measurable somatic effect. Although genetic effects as measured by dominant lethal mutation (DLM) assay indicated a significant effect (P>0.01) on the number of viable embryos and early deaths in the 3.0 μCi/ml HTO group and on the number of viable embryos in the 1.0 μCi/ml HTO group, no genetic effects were significantly noted in the 0.3 μCi/ml HTO group. Liver cytogenetic studies showed a significant increase in the number of abnormal cells in the 3.0 μCi/ml HTO group. A reduction in bone marrow stem cells, without an attendant reduction in total marrow cellularity, was noted in the 3.0 and 1.0 μCi/ml HTO groups. There was no significant difference in any of the DLM parameters between animals maintained on 3.0 μCi/ml of HTO and animals exposed to the equivalent 137 Cs gamma dose (22 hours/day exposure). Consideration of the relative amounts and biological half lives of tritium present in the nucleus as water, DNA and histone suggests that after transient exposure to tritiated water, nearly all significant radiation damage can be attributed to tritium present in the nucleus as water. These data suggest that hazards from tritium attendant with normal reactor operation should not at this time be considered as a deterrent to the further development of fission and/or fusion reactor technology. (Namekawa, K.)

  5. Genetic transformation of olive somatic embryos through ...

    African Journals Online (AJOL)

    Administrator

    2011-06-20

    Jun 20, 2011 ... 2Department of Biochemistry, National Center of Genetic Engineering and Biotechnology, Tehran, Iran. Accepted 9 March, 2011. Transformed olive plants were regenerated from inoculated somatic embryos with Agrobacterium tumefacience strain GV3101, which carries the plasmid pBI-P5CS containing ...

  6. Somatic Embryogenesis and Plant Regeneration in Eggplant ...

    African Journals Online (AJOL)

    DR SIDHU

    2013-02-20

    Feb 20, 2013 ... Two as well as three way interactions of three eggplant genotypes, media compositions and explants. (hypocotyl, cotyledon and leaf) showed significant differences for plant regeneration. Among three explants, hypocotyl induced highest percent callusing, but cotyledon showed best results for somatic.

  7. Studies for Somatic Embryogenesis in Sweet Potato

    Science.gov (United States)

    Bennett, J. Rasheed; Prakash, C. S.

    1997-01-01

    The purpose of this study was to improve the somatic embryo (SE) system for plant production of sweet potato (Ipomoea batatas L(Lam)). Explants isolated from SE-derived sweet potato plants were compared with control (non SE-derived) plants for their competency for SE production. Leaf explants were cultured on Murashige-Skoog (MS) medium with 2,4-dichlorophenoxy acetic acid (0.2 mg/L) and 6-benzylaminopurine (2.5 mg/L) for 2 weeks in darkness and transferred to MS medium with abscisic acid (2.5 mg/L). Explants isolated from those plants developed through somatic embryogenesis produced new somatic embryos rapidly and in higher frequency than those isolated from control plants They also appeared to grow faster in tissue culture than the control plants. Current studies in the laboratory are examining whether plants derived from a cyclical embryogenesis system (five cycles) would have any further positive impact on the rapidity and frequency of somatic embryo development. More detailed studies using electron microscopy are expected to show the point of origin of the embryos and to allow determination of their quality throughout the cyclical process. This study may facilitate improved plant micropropagation, gene transfer and germplasm conservation in sweet potato.

  8. Studies on Somatic Embryogenesis in Sweetpotato

    Science.gov (United States)

    Bennett, J. Rasheed; Prakash, C. S.

    1997-01-01

    The purpose of this study was to improve the somatic embryo (SE) system for plant production of sweetpotato Ipomoea batatas L.(Lam)l. Explants isolated from SE-derived sweet potato plants were compared with control (non SE-derived) plants for their competency for SE production. Leaf explants were cultured on Murashige-Skoog (MS) medium with 2,4-dichlorophenoxy acetic acid (0.2 mg/L) and 6-benzylaminopurine (2.5 mg/L) for 2 weeks in darkness and transferred to MS medium with abscisic acid (2.5 Explants isolated from those plants developed through somatic embryo-genesis produced new somatic embryos rapidly and in higher frequency than those isolated from control plants. They also appeared to grow faster in tissue culture than the control plants. Current studies in the laboratory are examining whether plants derived from a cyclical embryogenesis system (five cycles) would have any further positive impact on the rapidity and frequency of somatic embryo development. More detailed studies using electron microscopy are expected to show the point of origin of the embryos and to allow determination of their quality throughout the cyclical process. This study may facilitate improved plant micropropagation, gene transfer and germplasm conservation in sweet potato.

  9. Relationship between somatization and remission with ECT.

    Science.gov (United States)

    Rasmussen, Keith G; Snyder, Karen A; Knapp, Rebecca G; Mueller, Martina; Yim, Eunsil; Husain, Mustafa M; Rummans, Teresa A; Sampson, Shirlene M; O'Connor, M Kevin; Bernstein, Hilary J; Kellner, Charles H

    2004-12-30

    Patients treated with electroconvulsive therapy (ECT) were divided into those with less severe depression and those with more severe depression. In the less severely depressed group, high somatic anxiety and hypochondriasis predicted a low likelihood of sustained remission with ECT. In the more severely depressed group, these traits were not predictive of ECT outcome.

  10. Somatic And Behavioral Changes Associated With Difuse ...

    African Journals Online (AJOL)

    Aims: The effects of diffuse transcranial electrical stimulation on somatic and behavioral changes in anaesthetized and unanaesthetized normal male and female Wister rats was studied. Method: Diffuse transcranial electrical stimulation (0-25v, frequency 90Hz,pulse width 1ms) was administered via two electrodes clipped ...

  11. Somatic Symptoms in Traumatized Children and Adolescents

    Science.gov (United States)

    Kugler, Brittany B.; Bloom, Marlene; Kaercher, Lauren B.; Truax, Tatyana V.; Storch, Eric A.

    2012-01-01

    Childhood exposure to trauma has been associated with increased rates of somatic symptoms (SS), which may contribute to diminished daily functioning. One hundred and sixty-one children residing at a residential treatment home who had experienced neglect and/or abuse were administered the Trauma Symptom Checklist for Children (TSCC), the…

  12. Somatic Embryogenesis in Juniperus Procera using Juniperus ...

    African Journals Online (AJOL)

    The aim for this particular research was initially an adaptation of optimum half strength lithium chloride-sodium propionate (LP) medium protocol for growth and proliferation of embryogenic ... Additional study on the effect of seed extraction to the growing embryogenic culture showed no effect on mature somatic embryos.

  13. [Interdependance between somatic symptoms, sleep and dreams].

    Science.gov (United States)

    Todorov, Assya

    2014-03-19

    Even in an established illness, somatic complains can hide other emotional inquiries. The therapist, always with a kind attitude, can ask more about patient's sexual life. This can be use of having a better idea of patient's life and problems. Talking about dreams can also be useful: it gives new and surprising elements about patient's personality and helps to progress on healing's way.

  14. Depression, disability and somatic diseases among elderly

    NARCIS (Netherlands)

    Verhaak, P.F.M.; Dekker, Janny; De Waal, M.W.M.; Van Marwijk, H.W.J.; Comijs, H.C.

    2014-01-01

    Objective: Depression among older adults is associated with both disability and somatic disease. We aimed to further understand this complicated relationship and to study the possible modifying effect of increasing age. Design: Cross sectional survey. Setting: Outpatient and inpatient clinics of

  15. Writing Bodies: Somatic Mind in Composition Studies.

    Science.gov (United States)

    Fleckenstein, Kristie S.

    1999-01-01

    Discusses the somatic mind, a permeable materiality in which mind and body resolve into a single entity which is (re)formed by the constantly shifting boundaries of discursive and corporeal intertextualities. Addresses its importance in composition studies. Critiques the poststructuralist disregard of corporeality. (CR)

  16. Depression and hypochondriasis in family practice patients with somatization disorder.

    Science.gov (United States)

    Oxman, T E; Barrett, J

    1985-10-01

    The relationships specified in DSM-III between somatization disorder and depression, and somatization disorder and hypochondriasis require further validation and easier methods of detection for use by primary care physicians. The authors investigated hypochondriacal and depressive symptoms in 13 family practice outpatients with somatization disorder. Pain complaints and depressive symptomatology were present in over 75% of this group, while hypochondriacal symptoms were present in 38%. The mean score on the somatization scale of the Hopkins Symptom Check List (HSCL-90) was greater than that reported for any other group. These findings support the separation of somatization disorder and hypochondriasis and suggest the need for better delineation of depressive subtypes in somatization disorder. The somatization scale of the HSCL-90 should be a useful screen for somatization disorder in future research.

  17. Delusional disorder-somatic type (or body dysmorphic disorder) and ...

    African Journals Online (AJOL)

    to distinguish cases of delusional disorder of somatic subtype from severe somatization .... features suggestive of a paranoid schizophrenia. Paranoid schizophrenia ... Of note is that the patient's personality and psychosocial functioning were ...

  18. Construction of a combinatorial pipeline using two somatic variant  calling  methods  for whole exome sequence data of gastric cancer.

    Science.gov (United States)

    Kohmoto, Tomohiro; Masuda, Kiyoshi; Naruto, Takuya; Tange, Shoichiro; Shoda, Katsutoshi; Hamada, Junichi; Saito, Masako; Ichikawa, Daisuke; Tajima, Atsushi; Otsuji, Eigo; Imoto, Issei

    2017-01-01

    High-throughput next-generation sequencing is a powerful tool to identify the genotypic landscapes of somatic variants and therapeutic targets in various cancers including gastric cancer, forming the basis for personalized medicine in the clinical setting. Although the advent of many computational algorithms leads to higher accuracy in somatic variant calling, no standard method exists due to the limitations of each method. Here, we constructed a new pipeline. We combined two different somatic variant callers with different algorithms, Strelka and VarScan 2, and evaluated performance using whole exome sequencing data obtained from 19 Japanese cases with gastric cancer (GC); then, we characterized these tumors based on identified driver molecular alterations. More single nucleotide variants (SNVs) and small insertions/deletions were detected by Strelka and VarScan 2, respectively. SNVs detected by both tools showed higher accuracy for estimating somatic variants compared with those detected by only one of the two tools and accurately showed the mutation signature and mutations of driver genes reported for GC. Our combinatorial pipeline may have an advantage in detection of somatic mutations in GC and may be useful for further genomic characterization of Japanese patients with GC to improve the efficacy of GC treatments. J. Med. Invest. 64: 233-240, August, 2017.

  19. Germ cell regeneration-mediated, enhanced mutagenesis in the ascidian Ciona intestinalis reveals flexible germ cell formation from different somatic cells.

    Science.gov (United States)

    Yoshida, Keita; Hozumi, Akiko; Treen, Nicholas; Sakuma, Tetsushi; Yamamoto, Takashi; Shirae-Kurabayashi, Maki; Sasakura, Yasunori

    2017-03-15

    The ascidian Ciona intestinalis has a high regeneration capacity that enables the regeneration of artificially removed primordial germ cells (PGCs) from somatic cells. We utilized PGC regeneration to establish efficient methods of germ line mutagenesis with transcription activator-like effector nucleases (TALENs). When PGCs were artificially removed from animals in which a TALEN pair was expressed, somatic cells harboring mutations in the target gene were converted into germ cells, this germ cell population exhibited higher mutation rates than animals not subjected to PGC removal. PGC regeneration enables us to use TALEN expression vectors of specific somatic tissues for germ cell mutagenesis. Unexpectedly, cis elements for epidermis, neural tissue and muscle could be used for germ cell mutagenesis, indicating there are multiple sources of regenerated PGCs, suggesting a flexibility of differentiated Ciona somatic cells to regain totipotency. Sperm and eggs of a single hermaphroditic, PGC regenerated animal typically have different mutations, suggesting they arise from different cells. PGCs can be generated from somatic cells even though the maternal PGCs are not removed, suggesting that the PGC regeneration is not solely an artificial event but could have an endogenous function in Ciona. This study provides a technical innovation in the genome-editing methods, including easy establishment of mutant lines. Moreover, this study suggests cellular mechanisms and the potential evolutionary significance of PGC regeneration in Ciona. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Ataxia-telangiectasia mutated (ATM) deficiency decreases reprogramming efficiency and leads to genomic instability in iPS cells

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Taisuke [Department of Cell Differentiation, The Sakaguchi Laboratory, School of Medicine, Keio University, Tokyo 160-8582 (Japan); Nagamatsu, Go, E-mail: gonag@sc.itc.keio.ac.jp [Department of Cell Differentiation, The Sakaguchi Laboratory, School of Medicine, Keio University, Tokyo 160-8582 (Japan); Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Kosaka, Takeo [Department of Urology, School of Medicine, Keio University, Tokyo 160-8582 (Japan); Takubo, Keiyo [Department of Cell Differentiation, The Sakaguchi Laboratory, School of Medicine, Keio University, Tokyo 160-8582 (Japan); Hotta, Akitsu [Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Department of Reprogramming Science, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto (Japan); Ellis, James [Ontario Human iPS Cell Facility, Molecular Genetics, University of Toronto, Developmental and Stem Cell Biology, SickKids, Toronto, Canada MG1L7 (Canada); Suda, Toshio, E-mail: sudato@sc.itc.keio.ac.jp [Department of Cell Differentiation, The Sakaguchi Laboratory, School of Medicine, Keio University, Tokyo 160-8582 (Japan)

    2011-04-08

    Highlights: {yields} iPS cells were induced with a fluorescence monitoring system. {yields} ATM-deficient tail-tip fibroblasts exhibited quite a low reprogramming efficiency. {yields} iPS cells obtained from ATM-deficient cells had pluripotent cell characteristics. {yields} ATM-deficient iPS cells had abnormal chromosomes, which were accumulated in culture. -- Abstract: During cell division, one of the major features of somatic cell reprogramming by defined factors, cells are potentially exposed to DNA damage. Inactivation of the tumor suppressor gene p53 raised reprogramming efficiency but resulted in an increased number of abnormal chromosomes in established iPS cells. Ataxia-telangiectasia mutated (ATM), which is critical in the cellular response to DNA double-strand breaks, may also play an important role during reprogramming. To clarify the function of ATM in somatic cell reprogramming, we investigated reprogramming in ATM-deficient (ATM-KO) tail-tip fibroblasts (TTFs). Although reprogramming efficiency was greatly reduced in ATM-KO TTFs, ATM-KO iPS cells were successfully generated and showed the same proliferation activity as WT iPS cells. ATM-KO iPS cells had a gene expression profile similar to ES cells and WT iPS cells, and had the capacity to differentiate into all three germ layers. On the other hand, ATM-KO iPS cells accumulated abnormal genome structures upon continuous passages. Even with the abnormal karyotype, ATM-KO iPS cells retained pluripotent cell characteristics for at least 20 passages. These data indicate that ATM does participate in the reprogramming process, although its role is not essential.

  1. Ataxia-telangiectasia mutated (ATM) deficiency decreases reprogramming efficiency and leads to genomic instability in iPS cells

    International Nuclear Information System (INIS)

    Kinoshita, Taisuke; Nagamatsu, Go; Kosaka, Takeo; Takubo, Keiyo; Hotta, Akitsu; Ellis, James; Suda, Toshio

    2011-01-01

    Highlights: → iPS cells were induced with a fluorescence monitoring system. → ATM-deficient tail-tip fibroblasts exhibited quite a low reprogramming efficiency. → iPS cells obtained from ATM-deficient cells had pluripotent cell characteristics. → ATM-deficient iPS cells had abnormal chromosomes, which were accumulated in culture. -- Abstract: During cell division, one of the major features of somatic cell reprogramming by defined factors, cells are potentially exposed to DNA damage. Inactivation of the tumor suppressor gene p53 raised reprogramming efficiency but resulted in an increased number of abnormal chromosomes in established iPS cells. Ataxia-telangiectasia mutated (ATM), which is critical in the cellular response to DNA double-strand breaks, may also play an important role during reprogramming. To clarify the function of ATM in somatic cell reprogramming, we investigated reprogramming in ATM-deficient (ATM-KO) tail-tip fibroblasts (TTFs). Although reprogramming efficiency was greatly reduced in ATM-KO TTFs, ATM-KO iPS cells were successfully generated and showed the same proliferation activity as WT iPS cells. ATM-KO iPS cells had a gene expression profile similar to ES cells and WT iPS cells, and had the capacity to differentiate into all three germ layers. On the other hand, ATM-KO iPS cells accumulated abnormal genome structures upon continuous passages. Even with the abnormal karyotype, ATM-KO iPS cells retained pluripotent cell characteristics for at least 20 passages. These data indicate that ATM does participate in the reprogramming process, although its role is not essential.

  2. Reduced rates of gene loss, gene silencing, and gene mutation in Dnmt1-deficient embryonic stem cells

    NARCIS (Netherlands)

    Chan, M.F.; van Amerongen, R.; Nijjar, T.; Cuppen, E.; Jones, P.A.; Laird, P.W.

    2001-01-01

    Tumor suppressor gene inactivation is a crucial event in oncogenesis. Gene inactivation mechanisms include events resulting in loss of heterozygosity (LOH), gene mutation, and transcriptional silencing. The contribution of each of these different pathways varies among tumor suppressor genes and by

  3. Charge immobilization of the voltage sensor in domain IV is independent of sodium current inactivation.

    Science.gov (United States)

    Sheets, Michael F; Hanck, Dorothy A

    2005-02-15

    Recovery from fast inactivation in voltage-dependent Na+ channels is associated with a slow component in the time course of gating charge during repolarization (i.e. charge immobilization), which results from the slow movement of the S4 segments in domains III and IV (S4-DIII and S4-DIV). Previous studies have shown that the non-specific removal of fast inactivation by the proteolytic enzyme pronase eliminated charge immobilization, while the specific removal of fast inactivation (by intracellular MTSET modification of a cysteine substituted for the phenylalanine in the IFM motif, ICMMTSET, in the inactivation particle formed by the linker between domains III and IV) only reduced the amount of charge immobilization by nearly one-half. To investigate the molecular origin of the remaining slow component of charge immobilization we studied the human cardiac Na+ channel (hH1a) in which the outermost arginine in the S4-DIV, which contributes approximately 20% to total gating charge (Qmax), was mutated to a cysteine (R1C-DIV). Gating charge could be fully restored in R1C-DIV by exposure to extracellular MTSEA, a positively charged methanethiosulphonate reagent. The RIC-DIV mutation was combined with ICMMTSET to remove fast inactivation, and the gating currents of R1C-DIV-ICM(MTSET) were recorded before and after modification with MTSEAo. Prior to MTSEAo, the time course of the gating charge during repolarization (off-charge) was best described by a single fast time constant. After MTSEA, the off-charge had both fast and slow components, with the slow component accounting for nearly 35% of Qmax. These results demonstrate that the slow movement of the S4-DIV during repolarization is not dependent upon the normal binding of the inactivation particle.

  4. Knockout of exogenous EGFP gene in porcine somatic cells using zinc-finger nucleases

    International Nuclear Information System (INIS)

    Watanabe, Masahito; Umeyama, Kazuhiro; Matsunari, Hitomi; Takayanagi, Shuko; Haruyama, Erika; Nakano, Kazuaki; Fujiwara, Tsukasa; Ikezawa, Yuka; Nakauchi, Hiromitsu

    2010-01-01

    Research highlights: → EGFP gene integrated in porcine somatic cells could be knocked out using the ZFN-KO system. → ZFNs induced targeted mutations in porcine primary cultured cells. → Complete absence of EGFP fluorescence was confirmed in ZFN-treated cells. -- Abstract: Zinc-finger nucleases (ZFNs) are expected as a powerful tool for generating gene knockouts in laboratory and domestic animals. Currently, it is unclear whether this technology can be utilized for knocking-out genes in pigs. Here, we investigated whether knockout (KO) events in which ZFNs recognize and cleave a target sequence occur in porcine primary cultured somatic cells that harbor the exogenous enhanced green fluorescent protein (EGFP) gene. ZFN-encoding mRNA designed to target the EGFP gene was introduced by electroporation into the cell. Using the Surveyor nuclease assay and flow cytometric analysis, we confirmed ZFN-induced cleavage of the target sequence and the disappearance of EGFP fluorescence expression in ZFN-treated cells. In addition, sequence analysis revealed that ZFN-induced mutations such as base substitution, deletion, or insertion were generated in the ZFN cleavage site of EGFP-expression negative cells that were cloned from ZFN-treated cells, thereby showing it was possible to disrupt (i.e., knock out) the function of the EGFP gene in porcine somatic cells. To our knowledge, this study provides the first evidence that the ZFN-KO system can be applied to pigs. These findings may open a new avenue to the creation of gene KO pigs using ZFN-treated cells and somatic cell nuclear transfer.

  5. Development of direct somatic embryogenesis and regeneration on citrus sinesis

    International Nuclear Information System (INIS)

    Chong Saw Peng; Alvina Lindsay Mijen; Rusli Ibrahim

    2004-01-01

    The plant regeneration processes in Citrus sinensis involves direct somatic embryogenesis. Culture medium used was MS basal supplemented with 50 mg/L sucrose, 0.27% agar and 0.1% vitamin at pH 5.8. Sucrose is the major carbon source for the induction of somatic embryo and also the maturation and germination of somatic embryo. (Author)

  6. RB1 mutation spectrum in a comprehensive nationwide cohort of retinoblastoma patients

    NARCIS (Netherlands)

    Dommering, Charlotte J.; Mol, Berber M.; Moll, Annette C.; Burton, Margaret; Cloos, Jacqueline; Dorsman, Josephine C.; Meijers-Heijboer, Hanne; van der Hout, Annemarie H.

    Background Retinoblastoma (Rb) is a childhood cancer of the retina, commonly initiated by biallelic inactivation of the RB1 gene. Knowledge of the presence of a heritable RB1 mutation can help in risk management and reproductive decision making. We report here on RB1 mutation scanning in a unique

  7. Lack of Mutation-histopathology Correlation in a Patient with Proteus Syndrome

    OpenAIRE

    Doucet, Meggie E.; Bloomhardt, Hadley M.; Moroz, Krzysztof; Lindhurst, Marjorie J.; Biesecker, Leslie G.

    2016-01-01

    Proteus syndrome (PS) is characterized by progressive, disproportionate, segmental overgrowth and tumor susceptibility caused by a somatic mosaic AKT1 activating mutation. Each individual has unique manifestations making this disorder extremely heterogeneous. We correlated three variables in 38 tissue samples from a patient who died with PS: the gross affection status, the microscopic affection status, and the mutation level. The AKT1 mutation was measured using a PCR-based RFLP assay. Thirte...

  8. Complicated biallelic inactivation of Pten in radiation-induced mouse thymic lymphomas

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Yu [Department of Biology, Graduate School of Science, Chiba University, Yayoicho, Inage-ku, Chiba 263-8522 (Japan); Experimental Radiobiology for Children' s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Takabatake, Takashi; Kakinuma, Shizuko; Amasaki, Yoshiko; Nishimura, Mayumi; Imaoka, Tatsuhiko; Yamauchi, Kazumi; Shang, Yi [Experimental Radiobiology for Children' s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Miyoshi-Imamura, Tomoko [Experimental Radiobiology for Children' s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Genetic Counseling Program, Graduate School of Humanities and Sciences, Ochanomizu University, 2-1-1 Otsuka, Bunkyou-ku, Tokyo 112-8610 (Japan); Nogawa, Hiroyuki [Department of Biology, Graduate School of Science, Chiba University, Yayoicho, Inage-ku, Chiba 263-8522 (Japan); Kobayashi, Yoshiro [Department of Biomolecular Science, Faculty of Science, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510 (Japan); Shimada, Yoshiya, E-mail: y_shimad@nirsgo.jp [Experimental Radiobiology for Children' s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2010-04-01

    Inactivation of the phosphatase and tensin homolog gene (Pten) occurs via multiple tissue-dependent mechanisms including epigenetic silencing, point mutations, insertions, and deletions. Although frequent loss of heterozygosity around the Pten locus and plausible involvement of epigenetic silencing have been reported in radiation-induced thymic lymphomas, the proportion of lymphomas with inactivated Pten and the spectrum of causal aberrations have not been extensively characterized. Here, we assessed the mode of Pten inactivation by comprehensive analysis of the expression and alteration of Pten in 23 radiation-induced thymic lymphomas developed in B6C3F1 mice. We found no evidence for methylation-associated silencing of Pten; rather, complex structural abnormalities comprised of missense and nonsense mutations, 1- and 3-bp insertions, and focal deletions were identified in 8 of 23 lymphomas (35%). Sequencing of deletion breakpoints suggested that aberrant V(D)J recombination and microhomology-mediated rearrangement were responsible for the focal deletions. Seven of the 8 lymphomas had biallelic alterations, and 4 of them did not express Pten protein. These Pten aberrations coincided with downstream Akt phosphorylation. In conclusion, we demonstrate that Pten inactivation is frequently biallelic and is caused by a variety of structural abnormalities (rather than by epigenetic silencing) and is involved in radiation-induced lymphomagenesis.

  9. Disruption of the IS6-AID linker affects voltage-gated calcium channel inactivation and facilitation.

    Science.gov (United States)

    Findeisen, Felix; Minor, Daniel L

    2009-03-01

    Two processes dominate voltage-gated calcium channel (Ca(V)) inactivation: voltage-dependent inactivation (VDI) and calcium-dependent inactivation (CDI). The Ca(V)beta/Ca(V)alpha(1)-I-II loop and Ca(2+)/calmodulin (CaM)/Ca(V)alpha(1)-C-terminal tail complexes have been shown to modulate each, respectively. Nevertheless, how each complex couples to the pore and whether each affects inactivation independently have remained unresolved. Here, we demonstrate that the IS6-alpha-interaction domain (AID) linker provides a rigid connection between the pore and Ca(V)beta/I-II loop complex by showing that IS6-AID linker polyglycine mutations accelerate Ca(V)1.2 (L-type) and Ca(V)2.1 (P/Q-type) VDI. Remarkably, mutations that either break the rigid IS6-AID linker connection or disrupt Ca(V)beta/I-II association sharply decelerate CDI and reduce a second Ca(2+)/CaM/Ca(V)alpha(1)-C-terminal-mediated process known as calcium-dependent facilitation. Collectively, the data strongly suggest that components traditionally associated solely with VDI, Ca(V)beta and the IS6-AID linker, are essential for calcium-dependent modulation, and that both Ca(V)beta-dependent and CaM-dependent components couple to the pore by a common mechanism requiring Ca(V)beta and an intact IS6-AID linker.

  10. Enhanced vulnerability of human proteins towards disease-associated inactivation through divergent evolution.

    Science.gov (United States)

    Medina-Carmona, Encarnación; Fuchs, Julian E; Gavira, Jose A; Mesa-Torres, Noel; Neira, Jose L; Salido, Eduardo; Palomino-Morales, Rogelio; Burgos, Miguel; Timson, David J; Pey, Angel L

    2017-09-15

    Human proteins are vulnerable towards disease-associated single amino acid replacements affecting protein stability and function. Interestingly, a few studies have shown that consensus amino acids from mammals or vertebrates can enhance protein stability when incorporated into human proteins. Here, we investigate yet unexplored relationships between the high vulnerability of human proteins towards disease-associated inactivation and recent evolutionary site-specific divergence of stabilizing amino acids. Using phylogenetic, structural and experimental analyses, we show that divergence from the consensus amino acids at several sites during mammalian evolution has caused local protein destabilization in two human proteins linked to disease: cancer-associated NQO1 and alanine:glyoxylate aminotransferase, mutated in primary hyperoxaluria type I. We demonstrate that a single consensus mutation (H80R) acts as a disease suppressor on the most common cancer-associated polymorphism in NQO1 (P187S). The H80R mutation reactivates P187S by enhancing FAD binding affinity through local and dynamic stabilization of its binding site. Furthermore, we show how a second suppressor mutation (E247Q) cooperates with H80R in protecting the P187S polymorphism towards inactivation through long-range allosteric communication within the structural ensemble of the protein. Our results support that recent divergence of consensus amino acids may have occurred with neutral effects on many functional and regulatory traits of wild-type human proteins. However, divergence at certain sites may have increased the propensity of some human proteins towards inactivation due to disease-associated mutations and polymorphisms. Consensus mutations also emerge as a potential strategy to identify structural hot-spots in proteins as targets for pharmacological rescue in loss-of-function genetic diseases. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please

  11. Sequential acquisition of mutations in myelodysplastic syndromes.

    Science.gov (United States)

    Makishima, Hideki

    2017-01-01

    Recent progress in next-generation sequencing technologies allows us to discover frequent mutations throughout the coding regions of myelodysplastic syndromes (MDS), potentially providing us with virtually a complete spectrum of driver mutations in this disease. As shown by many study groups these days, such driver mutations are acquired in a gene-specific fashion. For instance, DDX41 mutations are observed in germline cells long before MDS presentation. In blood samples from healthy elderly individuals, somatic DNMT3A and TET2 mutations are detected as age-related clonal hematopoiesis and are believed to be a risk factor for hematological neoplasms. In MDS, mutations of genes such as NRAS and FLT3, designated as Type-1 genes, may be significantly associated with leukemic evolution. Another type (Type-2) of genes, including RUNX1 and GATA2, are related to progression from low-risk to high-risk MDS. Overall, various driver mutations are sequentially acquired in MDS, at a specific time, in either germline cells, normal hematopoietic cells, or clonal MDS cells.

  12. Radiobiological inactivation of Epstein-Barr virus

    International Nuclear Information System (INIS)

    Henderson, E.; Heston, L.; Grogan, E.; Miller, G.

    1978-01-01

    Lymphocyte transforming properties of B95-8 strain Epstein-Barr virus (EBV) are very sensitive to inactivation by either uv or x irradiation. No dose of irradiation increases the transforming capacity of EBV. The x-ray dose needed for inactivation of EBV transformation (dose that results in 37% survival, 60,000 rads) is similar to the dose required for inactivation of plaque formation by herpes simplex virus type 1 (Fischer strain). Although herpes simplex virus is more sensitive than EBV to uv irradiation, this difference is most likely due to differences in the kinetics or mechanisms of repair of uv damage to the two viruses. The results lead to the hypothesis that a large part, or perhaps all, of the EBV genome is in some way needed to initiate transformation. The abilities of EBV to stimulate host cell DNA synthesis, to induce nuclear antigen, and to immortalize are inactivated in parallel. All clones of marmoset cells transformed by irradiated virus produce extracellular transforming virus. These findings suggest that the abilities of the virus to transform and to replicate complete progeny are inactivated together. The amounts of uv and x irradiation that inactivate transformation by B95-8 virus are less than the dose needed to inactivate early antigen induction by the nontransforming P 3 HR-1 strain of EBV. Based on radiobiological inactivation, 10 to 50% of the genome is needed for early antigen induction

  13. Acute myeloid leukemia-associated DNMT3A p.Arg882His mutation in a patient with Tatton-Brown-Rahman overgrowth syndrome as a constitutional mutation.

    Science.gov (United States)

    Kosaki, Rika; Terashima, Hiroshi; Kubota, Masaya; Kosaki, Kenjiro

    2017-01-01

    DNA methylation plays a critical role in both embryonic development and tumorigenesis and is mediated through various DNA methyltransferases. Constitutional mutations in the de novo DNA methyltransferase DNMT3A cause a recently identified Tatton-Brown-Rahman overgrowth syndrome (TBRS). Somatically acquired mutations in DNMT3A are causally associated with acute myeloid leukemia (AML), and p.Arg882His represents the most prevalent hotspot. So far, no patients with TBRS have been reported to have subsequently developed AML. Here, we report a live birth and the survival of a female with the TBRS phenotype who had a heterozygous constitutional DNMT3A mutation at the AML somatic mutation hotspot p.Arg882His in her DNA from peripheral blood and buccal tissue. Her characteristic features at birth included hypotonia, narrow palpebral fissures, ventricular septal defect, umbilical hernia, sacral cyst, Chiari type I anomaly. At the age of 6 years, she exhibited overgrowth (> 3 SD) and round face and intellectual disability. This report represents the first documentation of the same variant (DNMT3A p.Arg882His) as both the constitutional mutation associated with TBRS and the somatic mutation hotspot of AML. The observation neither confirms nor denies the notion that mutations responsible for TBRS and those for AML might share the same mode of action. Larger data sets are required to determine whether TBRS patients with constitutional DNMT3A mutations are at an increased risk for AML. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. Immunoglobulin diversification in B cell malignancies: internal splicing of heavy chain variable region as a by-product of somatic hypermutation

    NARCIS (Netherlands)

    Bende, R. J.; Aarts, W. M.; Pals, S. T.; van Noesel, C. J. M.

    2002-01-01

    In this study we describe alternative splicing of somatically mutated immunoglobulin (Ig) variable heavy chain (V-H) genes in three distinct primary B cell non-Hodgkin's lymphomas (B-NHL). In two V4-34 expressing lymphomas, ie a post-germinal center type B cell chronic lymphocytic leukemia (B-CLL)

  15. Photodynamic Inactivation of Mammalian Viruses and Bacteriophages

    Directory of Open Access Journals (Sweden)

    Liliana Costa

    2012-06-01

    Full Text Available Photodynamic inactivation (PDI has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process.

  16. Inactivation of DNA mismatch repair by variants of uncertain significance in the PMS2 gene.

    Science.gov (United States)

    Drost, Mark; Koppejan, Hester; de Wind, Niels

    2013-11-01

    Lynch syndrome (LS) is a common cancer predisposition caused by an inactivating mutation in one of four DNA mismatch repair (MMR) genes. Frequently a variant of uncertain significance (VUS), rather than an obviously pathogenic mutation, is identified in one of these genes. The inability to define pathogenicity of such variants precludes targeted healthcare. Here, we have modified a cell-free assay to test VUS in the MMR gene PMS2 for functional activity. We have analyzed nearly all VUS in PMS2 found thus far and describe loss of MMR activity for five, suggesting the applicability of the assay for diagnosis of LS. © 2013 WILEY PERIODICALS, INC.

  17. Whole-genome sequencing identifies recurrent mutations in chronic lymphocytic leukaemia

    Science.gov (United States)

    Puente, Xose S.; Pinyol, Magda; Quesada, Víctor; Conde, Laura; Ordóñez, Gonzalo R.; Villamor, Neus; Escaramis, Georgia; Jares, Pedro; Beà, Sílvia; González-Díaz, Marcos; Bassaganyas, Laia; Baumann, Tycho; Juan, Manel; López-Guerra, Mónica; Colomer, Dolors; Tubío, José M. C.; López, Cristina; Navarro, Alba; Tornador, Cristian; Aymerich, Marta; Rozman, María; Hernández, Jesús M.; Puente, Diana A.; Freije, José M. P.; Velasco, Gloria; Gutiérrez-Fernández, Ana; Costa, Dolors; Carrió, Anna; Guijarro, Sara; Enjuanes, Anna; Hernández, Lluís; Yagüe, Jordi; Nicolás, Pilar; Romeo-Casabona, Carlos M.; Himmelbauer, Heinz; Castillo, Ester; Dohm, Juliane C.; de Sanjosé, Silvia; Piris, Miguel A.; de Alava, Enrique; Miguel, Jesús San; Royo, Romina; Gelpí, Josep L.; Torrents, David; Orozco, Modesto; Pisano, David G.; Valencia, Alfonso; Guigó, Roderic; Bayés, Mónica; Heath, Simon; Gut, Marta; Klatt, Peter; Marshall, John; Raine, Keiran; Stebbings, Lucy A.; Futreal, P. Andrew; Stratton, Michael R.; Campbell, Peter J.; Gut, Ivo; López-Guillermo, Armando; Estivill, Xavier; Montserrat, Emili; López-Otín, Carlos; Campo, Elías

    2012-01-01

    Chronic lymphocytic leukaemia (CLL), the most frequent leukaemia in adults in Western countries, is a heterogeneous disease with variable clinical presentation and evolution1,2. Two major molecular subtypes can be distinguished, characterized respectively by a high or low number of somatic hypermutations in the variable region of immunoglobulin genes3,4. The molecular changes leading to the pathogenesis of the disease are still poorly understood. Here we performed whole-genome sequencing of four cases of CLL and identified 46 somatic mutations that potentially affect gene function. Further analysis of these mutations in 363 patients with CLL identified four genes that are recurrently mutated: notch 1 (NOTCH1), exportin 1 (XPO1), myeloid differentiation primary response gene 88 (MYD88) and kelch-like 6 (KLHL6). Mutations in MYD88 and KLHL6 are predominant in cases of CLL with mutated immunoglobulin genes, whereas NOTCH1 and XPO1 mutations are mainly detected in patients with unmutated immunoglobulins. The patterns of somatic mutation, supported by functional and clinical analyses, strongly indicate that the recurrent NOTCH1, MYD88 and XPO1 mutations are oncogenic changes that contribute to the clinical evolution of the disease. To our knowledge, this is the first comprehensive analysis of CLL combining whole-genome sequencing with clinical characteristics and clinical outcomes. It highlights the usefulness of this approach for the identification of clinically relevant mutations in cancer. PMID:21642962

  18. Mechanism of Bacillus subtilis spore inactivation by and resistance to supercritical CO2 plus peracetic acid.

    Science.gov (United States)

    Setlow, B; Korza, G; Blatt, K M S; Fey, J P; Setlow, P

    2016-01-01

    Determine how supercritical CO2 (scCO2 ) plus peracetic acid (PAA) inactivates Bacillus subtilis spores, factors important in spore resistance to scCO2 -PAA, and if spores inactivated by scCO2 -PAA are truly dead. Spores of wild-type B. subtilis and isogenic mutants lacking spore protective proteins were treated with scCO2 -PAA in liquid or dry at 35°C. Wild-type wet spores (aqueous suspension) were more susceptible than dry spores. Treated spores were examined for viability (and were truly dead), dipicolinic acid (DPA), mutations, permeability to nucleic acid stains, germination under different conditions, energy metabolism and outgrowth. ScCO2 -PAA-inactivated spores retained DPA, and survivors had no notable DNA damage. However, DPA was released from inactivated spores at a normally innocuous temperature (85°C), and colony formation from treated spores was salt sensitive. The inactivated spores germinated but did not outgrow, and these germinated spores had altered plasma membrane permeability and defective energy metabolism. Wet or dry coat-defective spores had increased scCO2 -PAA sensitivity, and dry spores but not wet spores lacking DNA protective proteins were more scCO2 -PAA sensitive. These findings suggest that scCO2 -PAA inactivates spores by damaging spores' inner membrane. The spore coat provided scCO2 -PAA resistance for both wet and dry spores. DNA protective proteins provided scCO2 -PAA resistance only for dry spores. These results provide information on mechanisms of spore inactivation of and resistance to scCO2 -PAA, an agent with increasing use in sterilization applications. © 2015 The Society for Applied Microbiology.

  19. Defect in IgV gene somatic hypermutation in common variable immuno-deficiency syndrome.

    Science.gov (United States)

    Levy, Y; Gupta, N; Le Deist, F; Garcia, C; Fischer, A; Weill, J C; Reynaud, C A

    1998-10-27

    Common Variable Immuno-Deficiency (CVID) is the most common symptomatic primary antibody-deficiency syndrome, but the basic immunologic defects underlying this syndrome are not well defined. We report here that among eight patients studied (six CVID and two hypogammaglobulinemic patients with recurrent infections), there is in two CVID patients a dramatic reduction in Ig V gene somatic hypermutation with 40-75% of IgG transcripts totally devoid of mutations in the circulating memory B cell compartment. Functional assays of the T cell compartment point to an intrinsic B cell defect in the process of antibody affinity maturation in these two cases.

  20. Evaluation of the recombination in somatic cells induced by radiation in different stages of Drosophila larval development

    International Nuclear Information System (INIS)

    Cruces, M.P.; Morales R, P.

    1997-01-01

    The mitotic recombination can happen spontaneously and its frequency is very low, however the recombination rate of a cell can be increased by the exposure to agents which cause damage to DNA. This type of agents are knew commonly as recombinogens. The ionizing radiation and a numerous chemical agents can be mentioned (Vogel, 1992). The objective of this work is to determine if the mutation/recombination rate induced by gamma rays varies with the development stage. In order to realize this investigation it was used the mutation and somatic recombination test of Drosophila wing (Graf and col. 1984). The mwh/ mwh and flr 3 /TM3, Ser stocks were used. (Author)

  1. Dogs cloned from adult somatic cells.

    Science.gov (United States)

    Lee, Byeong Chun; Kim, Min Kyu; Jang, Goo; Oh, Hyun Ju; Yuda, Fibrianto; Kim, Hye Jin; Hossein, M Shamim; Shamim, M Hossein; Kim, Jung Ju; Kang, Sung Keun; Schatten, Gerald; Hwang, Woo Suk

    2005-08-04

    Several mammals--including sheep, mice, cows, goats, pigs, rabbits, cats, a mule, a horse and a litter of three rats--have been cloned by transfer of a nucleus from a somatic cell into an egg cell (oocyte) that has had its nucleus removed. This technology has not so far been successful in dogs because of the difficulty of maturing canine oocytes in vitro. Here we describe the cloning of two Afghan hounds by nuclear transfer from adult skin cells into oocytes that had matured in vivo. Together with detailed sequence information generated by the canine-genome project, the ability to clone dogs by somatic-cell nuclear transfer should help to determine genetic and environmental contributions to the diverse biological and behavioural traits associated with the many different canine breeds.

  2. Should general psychiatry ignore somatization and hypochondriasis?

    Science.gov (United States)

    Creed, Francis

    2006-10-01

    This paper examines the tendency for general psychiatry to ignore somatization and hypochondriasis. These disorders are rarely included in national surveys of mental health and are not usually regarded as a concern of general psychiatrists; yet primary care doctors and other physicians often feel let down by psychiatry's failure to offer help in this area of medical practice. Many psychiatrists are unaware of the suffering, impaired function and high costs that can result from these disorders, because these occur mainly within primary care and secondary medical services. Difficulties in diagnosis and a tendency to regard them as purely secondary phenomena of depression, anxiety and related disorders mean that general psychiatry may continue to ignore somatization and hypochondriasis. If general psychiatry embraced these disorders more fully, however, it might lead to better prevention and treatment of depression as well as helping to prevent the severe disability that may arise in association with these disorders.

  3. Studies on cytological, physiological and genetic characteristics in somatic mutant strains of Sugi (Cryptomeria japonica D. Don)

    International Nuclear Information System (INIS)

    Maeta, T.; Somegou, M.; Nakahira, K.; Miyazaki, Y.; Kondo, T.

    1982-01-01

    From microscopic observation of the pollen of induced mutant strains in Sugi (Cryptomeria japonica D. Don), it was found that there were large differences in pollen fertility among the mutant strains, and that it deviated year to year from the mother plants. The large differences in frequency of sterile pollen among mutant strains depended on the genetic characteristics of each mutant strain. Higher frequencies of sterile pollen were observed at the terminal part of branchlets in some mutant strains, and this was considered to be induced by the lateness of flower-bud formation at low temperature conditions in late summer. Delayed formation and gibberellic acid treatment applied for flower induction resulted in low fertility and abnormality of pollen in mutant strains. Chromosome aberration in mutant strains was caused either by gamma irradiation or by some mutational events that responded to environmental conditions. In the former case, aberration might have been maintained for a long period through vegetative propagation. Some of the irregularities were due to mitotic cell division, because cells with micronuclei at the pacytene stage in pollen mother cells and with fragments at MI were observed. Somatic mutability of Kuma-sugi mutants after re-irradiation was investigated. From waxless mutants morphological somatic mutations, which have fat or stout stems and thick and short needles, were frequently produced, whereas from morphological mutants the lowest somatic mutation frequency was induced. In some mutant strains higher rooting ability than the mother plants was found, and the possibility of character improvement was pointed out. (author)

  4. Should general psychiatry ignore somatization and hypochondriasis?

    OpenAIRE

    CREED, FRANCIS

    2006-01-01

    This paper examines the tendency for general psychiatry to ignore somatization and hypochondriasis. These disorders are rarely included in national surveys of mental health and are not usually regarded as a concern of general psychiatrists; yet primary care doctors and other physicians often feel let down by psychiatry's failure to offer help in this area of medical practice. Many psychiatrists are unaware of the suffering, impaired function and high costs that can result fr...

  5. Is Pilates a Somatic Education Method?

    Directory of Open Access Journals (Sweden)

    Débora Pereira

    2014-12-01

    Full Text Available This paper renews the discussion about the relevance of the Pilates method to the field of Somatic Education. The impact of marketing – which sells the method as a fitness activity – and the academic research on the application of the method in the treatment of various medical disorders, as well as its role in the construction of contemporary dance aesthetics, are put into perspective.

  6. The somatic shunt cable model for neurons.

    OpenAIRE

    Durand, D

    1984-01-01

    The derivation of the equations for an electrical model of nerve cells is presented. The model consists of an equivalent cylinder, a lumped somatic impedance, and a variable shunt at the soma. This shunt was introduced to take into account the fast voltage decays observed following the injections of current pulses in some motoneurons and hippocampal granule cells that could not be explained by existing models. The shunt can be interpreted either by penetration damage with the electrode or by ...

  7. Analysis of a new morphogenetic mutation in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Mglinets, V.A.

    1987-01-01

    Somatic mosaicism for mutations monster and yellow was induced by gamma-irradiation of Drosophila melanogaster y/y; Dp(1; 2)sc 19 M(2)z/mn d embryos and larvae. Frequencies of mosaicism increased with the age of treated larvae, especially in the end of the 2nd larval instar. Autonomous expression of mn was observed throughout the whole range of larval age studied, though neither for all y/y spots nor for all parts of the spots. Dissimilarities in dynamics of mosaic spots and duplication induction suggest that the latter are not due to mn expression in somatic clones

  8. Children of people with somatization disorder.

    Science.gov (United States)

    Livingston, R

    1993-05-01

    The author investigated psychopathology, suicidal behavior, child abuse, somatization, and health care utilization in 34 children with a parent who has somatization disorder (SD-P) and two comparison groups: 41 children with a somatizing parent (SOM) (fewer symptoms than required for diagnosis of SD-P), and 30 pediatrically ill controls (CON). Child and parent versions of the Diagnostic Interview for Children and Adolescents were scored for diagnosis and symptom counts in specified categories. Medical records were obtained and abstracted. Children of SD-P had significantly more psychiatric disorders and suicide attempts than did children of SOM or the CON. SD-P and CON had significantly more unexplained physical symptoms than SOM. SD-P showed a trend toward more hospitalizations and experienced significantly more maltreatment. Children of SD-P are at significant risk in several respects. Clinical implications of these findings include a need for awareness and cooperation among general psychiatrists, primary care physicians, and child and adolescent psychiatrists to facilitate detection and treatment of these children's problems.

  9. SMARCB1/INI1 inactivation in renal medullary carcinoma.

    Science.gov (United States)

    Calderaro, Julien; Moroch, Julien; Pierron, Gaelle; Pedeutour, Florence; Grison, Camille; Maillé, Pascale; Soyeux, Pascale; de la Taille, Alexandre; Couturier, Jérome; Vieillefond, Annick; Rousselet, Marie Christine; Delattre, Olivier; Allory, Yves

    2012-09-01

    Renal medullary carcinoma (RMC), a rare and highly aggressive tumour which occurs in patients with sickle-cell disease, shares many clinicopathological features with collecting duct carcinoma (CDC). The molecular mechanisms underlying RMC and CDC are mainly unknown, and there is ongoing debate about their status as distinct entities. Loss of expression of SMARCB1/INI1, a chromatin remodelling regulator and repressor of cyclin D1 transcription, has been reported recently in RMC. The aim of our study was to investigate if such loss of expression is specific for RMC. SMARCB1/INI1 genetic alterations and cyclin D1 expression were also studied. Using immunochemistry, neoplastic cells showed complete loss of SMARCB1/INI1 expression in all six cases of RMC but in only one of 22 cases of CDC. In two RMC cases investigated, comparative genomic hybridization demonstrated complete loss of one SMARCB1/INI1 allele, with no other genomic imbalances, and no mutations were found on the remaining allele. Cyclin D1 was expressed in all RMCs, suggesting that SMARCB1/INI1 inactivation may result in increased cyclin D1 transcription. The specific SMARCB1/INI1 inactivation observed in RMCs suggests that RMC and CDC are different entities. © 2012 Blackwell Publishing Ltd.

  10. Biallelic inactivation of REV7 is associated with Fanconi anemia.

    Science.gov (United States)

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

    2016-09-01

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

  11. The mechanism of gene targeting in human somatic cells.

    Directory of Open Access Journals (Sweden)

    Yinan Kan

    2014-04-01

    Full Text Available Gene targeting in human somatic cells is of importance because it can be used to either delineate the loss-of-function phenotype of a gene or correct a mutated gene back to wild-type. Both of these outcomes require a form of DNA double-strand break (DSB repair known as homologous recombination (HR. The mechanism of HR leading to gene targeting, however, is not well understood in human cells. Here, we demonstrate that a two-end, ends-out HR intermediate is valid for human gene targeting. Furthermore, the resolution step of this intermediate occurs via the classic DSB repair model of HR while synthesis-dependent strand annealing and Holliday Junction dissolution are, at best, minor pathways. Moreover, and in contrast to other systems, the positions of Holliday Junction resolution are evenly distributed along the homology arms of the targeting vector. Most unexpectedly, we demonstrate that when a meganuclease is used to introduce a chromosomal DSB to augment gene targeting, the mechanism of gene targeting is inverted to an ends-in process. Finally, we demonstrate that the anti-recombination activity of mismatch repair is a significant impediment to gene targeting. These observations significantly advance our understanding of HR and gene targeting in human cells.

  12. DNA polymerase η mutational signatures are found in a variety of different types of cancer.

    Science.gov (United States)

    Rogozin, Igor B; Goncearenco, Alexander; Lada, Artem G; De, Subhajyoti; Yurchenko, Vyacheslav; Nudelman, German; Panchenko, Anna R; Cooper, David N; Pavlov, Youri I

    2018-01-01

    DNA polymerase (pol) η is a specialized error-prone polymerase with at least two quite different and contrasting cellular roles: to mitigate the genetic consequences of solar UV irradiation, and promote somatic hypermutation in the variable regions of immunoglobulin genes. Misregulation and mistargeting of pol η can compromise genome integrity. We explored whether the mutational signature of pol η could be found in datasets of human somatic mutations derived from normal and cancer cells. A substantial excess of single and tandem somatic mutations within known pol η mutable motifs was noted in skin cancer as well as in many other types of human cancer, suggesting that somatic mutations in A:T bases generated by DNA polymerase η are a common feature of tumorigenesis. Another peculiarity of pol ηmutational signatures, mutations in YCG motifs, led us to speculate that error-prone DNA synthesis opposite methylated CpG dinucleotides by misregulated pol η in tumors might constitute an additional mechanism of cytosine demethylation in this hypermutable dinucleotide.

  13. Consensus for EGFR mutation testing in non-small cell lung cancer: results from a European workshop

    DEFF Research Database (Denmark)

    Pirker, Robert; Herth, Felix J F; Kerr, Keith M

    2010-01-01

    Activating somatic mutations of the tyrosine kinase domain of epidermal growth factor receptor (EGFR) have recently been characterized in a subset of patients with advanced non-small cell lung cancer (NSCLC). Patients harboring these mutations in their tumors show excellent response to EGFR tyros...

  14. Mutations induced by X-radiation in the yeast Schizosaccharomyces pombe

    International Nuclear Information System (INIS)

    Loprieno, N.; Barale, R.; Baroncelli, S.; Cammellini, A.; Melani, M.; Nieri, R.; Nozzolini, M.; Rossi, A.M.; Pisa Univ.

    1975-01-01

    Experiments on strains of yeast with different genetic backgrounds were done to evaluate the kinetics of inactivation and mutation induction by X-radiation. A system of forward mutation induction in five loci was used and a specific mutation rate was evaluated for the wild type. From a comparison of observations with wild type and radiation-sensitive strains, it may be assumed that in this yeast, mutations are mainly the result of a repair-active process. The range of genotypic and phenotypic influence upon the specific locus mutation rate was evaluated with appropriate biological material and experiments

  15. Somatically Acquired LINE-1 Insertions in Normal Esophagus Undergo Clonal Expansion in Esophageal Squamous Cell Carcinoma.

    Science.gov (United States)

    Doucet-O'Hare, Tara T; Sharma, Reema; Rodić, Nemanja; Anders, Robert A; Burns, Kathleen H; Kazazian, Haig H

    2016-09-01

    Squamous cell carcinoma of the esophagus (SCC) is the most common form of esophageal cancer in the world and is typically diagnosed at an advanced stage when successful treatment is challenging. Understanding the mutational profile of this cancer may identify new treatment strategies. Because somatic retrotransposition has been shown in tumors of the gastrointestinal system, we focused on LINE-1 (L1) mobilization as a source of genetic instability in this cancer. We hypothesized that retrotransposition is ongoing in SCC patients. The expression of L1 encoded proteins is necessary for retrotransposition to occur; therefore, we evaluated the expression of L1 open reading frame 1 protein (ORF1p). Using immunohistochemistry, we detected ORF1p expression in all four SCC cases evaluated. Using L1-seq, we identified and validated 74 somatic insertions in eight tumors of the nine evaluated. Of these, 12 insertions appeared to be somatic, not genetically inherited, and sub-clonal (i.e., present in less than one copy per genome equivalent) in the adjacent normal esophagus (NE), while clonal in the tumor. Our results indicate that L1 retrotransposition is active in SCC of the esophagus and that insertion events are present in histologically NE that expands clonally in the subsequent tumor. © 2016 WILEY PERIODICALS, INC.

  16. Mutational Profiling of Malignant Mesothelioma Revealed Potential Therapeutic Targets in EGFR and NRAS

    Directory of Open Access Journals (Sweden)

    Jeong Eun Kim

    2018-04-01

    Full Text Available Pemetrexed and platinum (PP combination chemotherapy is the current standard first-line therapy for treatment of malignant mesothelioma (MM. However, a useful predictive biomarker for PP therapy is yet to be found. Here, we performed targeted exome sequencing to profile somatic mutations and copy number variations in 12 MM patients treated with PP therapy. We identified 187 somatic mutations in 12 patients (65 synonymous, 102 missense, 2 nonsense, 5 splice site, and 13 small coding insertions/deletions. We identified somatic mutations in 23 genes including BAP1, TP53, NRAS, and EGFR. Interestingly, rare NRAS p.Q61K and EGFR exon 19 deletions were observed in 2 patients. We also found somatic chromosomal copy number deletions in CDKN2A and CDKN2B genes. Genetic alteration related to response after PP therapy was not found. Somatic mutation profiling in MM patients receiving PP therapy revealed genetic alterations in potential therapeutic targets such as NRAS and EGFR. No alterations in genes with potential predictive role for PP therapy were found.

  17. Mutational Profiling of Malignant Mesothelioma Revealed Potential Therapeutic Targets in EGFR and NRAS.

    Science.gov (United States)

    Kim, Jeong Eun; Kim, Deokhoon; Hong, Yong Sang; Kim, Kyu-Pyo; Yoon, Young Kwang; Lee, Dae Ho; Kim, Sang-We; Chun, Sung-Min; Jang, Se Jin; Kim, Tae Won

    2018-04-01

    Pemetrexed and platinum (PP) combination chemotherapy is the current standard first-line therapy for treatment of malignant mesothelioma (MM). However, a useful predictive biomarker for PP therapy is yet to be found. Here, we performed targeted exome sequencing to profile somatic mutations and copy number variations in 12 MM patients treated with PP therapy. We identified 187 somatic mutations in 12 patients (65 synonymous, 102 missense, 2 nonsense, 5 splice site, and 13 small coding insertions/deletions). We identified somatic mutations in 23 genes including BAP1, TP53, NRAS, and EGFR. Interestingly, rare NRAS p.Q61K and EGFR exon 19 deletions were observed in 2 patients. We also found somatic chromosomal copy number deletions in CDKN2A and CDKN2B genes. Genetic alteration related to response after PP therapy was not found. Somatic mutation profiling in MM patients receiving PP therapy revealed genetic alterations in potential therapeutic targets such as NRAS and EGFR. No alterations in genes with potential predictive role for PP therapy were found. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  18. JAK and MPL mutations in myeloid malignancies.

    Science.gov (United States)

    Tefferi, Ayalew

    2008-03-01

    The Janus family of non-receptor tyrosine kinases (JAK1, JAK2, JAK3 and tyrosine kinase 2) transduces signals downstream of type I and II cytokine receptors via signal transducers and activators of transcription (STATs). JAK3 is important in lymphoid and JAK2 in myeloid cell proliferation and differentiation. The thrombopoietin receptor MPL is one of several JAK2 cognate receptors and is essential for myelopoiesis in general and megakaryopoiesis in particular. Germline loss-of-function (LOF) JAK3 and MPL mutations cause severe combined immunodeficiency and congenital amegakaryocytic thrombocytopenia, respectively. Germline gain-of-function (GOF) MPL mutation (MPLS505N) causes familial thrombocytosis. Somatic JAK3 (e.g. JAK3A572V, JAK3V722I, JAK3P132T) and fusion JAK2 (e.g. ETV6-JAK2, PCM1-JAK2, BCR-JAK2) mutations have respectively been described in acute megakaryocytic leukemia and acute leukemia/chronic myeloid malignancies. However, current attention is focused on JAK2 (e.g. JAK2V617F, JAK2 exon 12 mutations) and MPL (e.g. MPLW515L/K/S, MPLS505N) mutations associated with myeloproliferative neoplasms (MPNs). A JAK2 mutation, primarily JAK2V617F, is invariably associated with polycythemia vera (PV). The latter mutation also occurs in the majority of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). MPL mutational frequency in MPNs is substantially less (<10%). In general, despite a certain degree of genotype - phenotype correlations, the prognostic relevance of harbouring one of these mutations, or their allele burden when present, remains dubious. Regardless, based on the logical assumption that amplified JAK-STAT signalling is central to the pathogenesis of PV, ET and PMF, several anti-JAK2 tyrosine kinase inhibitors have been developed and are currently being tested in humans with these disorders.

  19. Genetic characterization in symptomatic female DMD carriers: lack of relationship between X-inactivation, transcriptional DMD allele balancing and phenotype

    Directory of Open Access Journals (Sweden)

    Brioschi Simona

    2012-08-01

    Full Text Available Abstract Background Although Duchenne and Becker muscular dystrophies, X-linked recessive myopathies, predominantly affect males, a clinically significant proportion of females manifesting symptoms have also been reported. They represent an heterogeneous group characterized by variable degrees of muscle weakness and/or cardiac involvement. Though preferential inactivation of the normal X chromosome has long been considered the principal mechanism behind disease manifestation in these females, supporting evidence is controversial. Methods Eighteen females showing a mosaic pattern of dystrophin expression on muscle biopsy were recruited and classified as symptomatic (7 or asymptomatic (11, based on the presence or absence of muscle weakness. The causative DMD gene mutations were identified in all cases, and the X-inactivation pattern was assessed in muscle DNA. Transcriptional analysis in muscles was performed in all females, and relative quantification of wild-type and mutated transcripts was also performed in 9 carriers. Dystrophin protein was quantified by immunoblotting in 2 females. Results The study highlighted a lack of relationship between dystrophic phenotype and X-inactivation pattern in females; skewed X-inactivation was found in 2 out of 6 symptomatic carriers and in 5 out of 11 asymptomatic carriers. All females were characterized by biallelic transcription, but no association was found between X-inactivation pattern and allele transcriptional balancing. Either a prevalence of wild-type transcript or equal proportions of wild-type and mutated RNAs was observed in both symptomatic and asymptomatic females. Moreover, very similar levels of total and wild-type transcripts were identified in the two groups of carriers. Conclusions This is the first study deeply exploring the DMD transcriptional behaviour in a cohort of female carriers. Notably, no relationship between X-inactivation pattern and transcriptional behaviour of DMD gene was

  20. The somatic symptom scale-8 (SSS-8): a brief measure of somatic symptom burden.

    Science.gov (United States)

    Gierk, Benjamin; Kohlmann, Sebastian; Kroenke, Kurt; Spangenberg, Lena; Zenger, Markus; Brähler, Elmar; Löwe, Bernd

    2014-03-01

    Somatic symptoms are the core features of many medical diseases, and they are used to evaluate the severity and course of illness. The 8-item Somatic Symptom Scale (SSS-8) was recently developed as a brief, patient-reported outcome measure of somatic symptom burden, but its reliability, validity, and usefulness have not yet been tested. To investigate the reliability, validity, and severity categories as well as the reference scores of the SSS-8. A national, representative general-population survey was performed between June 15, 2012, and July 15, 2012, in Germany, including 2510 individuals older than 13 years. The SSS-8 mean (SD), item-total correlations, Cronbach α, factor structure, associations with measures of construct validity (Patient Health Questionnaire-2 depression scale, Generalized Anxiety Disorder-2 scale, visual analog scale for general health status, 12-month health care use), severity categories, and percentile rank reference scores. The SSS-8 had excellent item characteristics and good reliability (Cronbach α = 0.81). The factor structure reflects gastrointestinal, pain, fatigue, and cardiopulmonary aspects of the general somatic symptom burden. Somatic symptom burden as measured by the SSS-8 was significantly associated with depression (r = 0.57 [95% CI, 0.54 to 0.60]), anxiety (r = 0.55 [95% CI, 0.52 to 0.58]), general health status (r = -0.24 [95% CI, -0.28 to -0.20]), and health care use (incidence rate ratio, 1.12 [95% CI, 1.10 to 1.14]). The SSS-8 severity categories were calculated in accordance with percentile ranks: no to minimal (0-3 points), low (4-7 points), medium (8-11 points), high (12-15 points), and very high (16-32 points) somatic symptom burden. For every SSS-8 severity category increase, there was a 53% (95% CI, 44% to 63%) increase in health care visits. The SSS-8 is a reliable and valid self-report measure of somatic symptom burden. Cutoff scores identify individuals with low, medium, high, and very high somatic

  1. Finding cancer driver mutations in the era of big data research.

    Science.gov (United States)

    Poulos, Rebecca C; Wong, Jason W H

    2018-04-02

    In the last decade, the costs of genome sequencing have decreased considerably. The commencement of large-scale cancer sequencing projects has enabled cancer genomics to join the big data revolution. One of the challenges still facing cancer genomics research is determining which are the driver mutations in an individual cancer, as these contribute only a small subset of the overall mutation profile of a tumour. Focusing primarily on somatic single nucleotide mutations in this review, we consider both coding and non-coding driver mutations, and discuss how such mutations might be identified from cancer sequencing datasets. We describe some of the tools and database that are available for the annotation of somatic variants and the identification of cancer driver genes. We also address the use of genome-wide variation in mutation load to establish background mutation rates from which to identify driver mutations under positive selection. Finally, we describe the ways in which mutational signatures can act as clues for the identification of cancer drivers, as these mutations may cause, or arise from, certain mutational processes. By defining the molecular changes responsible for driving cancer development, new cancer treatment strategies may be developed or novel preventative measures proposed.

  2. Impact of germline and somatic missense variations on drug binding sites.

    Science.gov (United States)

    Yan, C; Pattabiraman, N; Goecks, J; Lam, P; Nayak, A; Pan, Y; Torcivia-Rodriguez, J; Voskan