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Sample records for repair mmr gene

  1. Evaluation of Lynch syndrome modifier genes in 748 MMR mutation carriers.

    Science.gov (United States)

    Houlle, Solene; Charbonnier, Françoise; Houivet, Estelle; Tinat, Julie; Buisine, Marie-Pierre; Caron, Olivier; Benichou, Jacques; Baert-Desurmont, Stéphanie; Frebourg, Thierry

    2011-08-01

    Several studies have reported that, in Lynch syndrome resulting from mutations of the mismatch repair (MMR) genes, a CA repeat ≤17 within the IGF1 promoter, SNPs within the xenobiotic metabolizing enzyme gene CYP1A1 and SNPs on 8q23.3 and 11q23.1 modify colorectal cancer (CRC) risk in MMR mutation carriers. We analysed the impact of these polymorphisms on CRC risk in 748 French MMR mutation carriers derived from 359 families. We also analysed the effect of the Novel 1 SNP (18q21), which has recently been shown to increase CRC risk in the general population. We observed a significant difference in the CRC-free survival time between males and females, between MSH2 and MSH6 mutation carriers and between MLH1 and MSH6, indicating that this series is representative of Lynch syndrome. In contrast, the univariate log-rank test, as well as multivariate Cox model analysis controlling for familial aggregation and mutated MMR gene, year of birth and gender showed that the polymorphic alleles tested were not associated with a significant CRC risk increase, neither on the entire sample nor among males and females. This discrepancy with previous reports might be explained both by the genetic heterogeneity between the different populations analysed and the allelic heterogeneity of the MMR mutations. We conclude that genotyping of these polymorphisms is not useful to evaluate CRC risk in MMR mutation carriers and to optimize their clinical follow-up.

  2. Diversity of the clinical presentation of the MMR gene biallelic mutations.

    Science.gov (United States)

    Bougeard, Gaëlle; Olivier-Faivre, Laurence; Baert-Desurmont, Stéphanie; Tinat, Julie; Martin, Cosette; Bouvignies, Emilie; Vasseur, Stéphanie; Huet, Frédéric; Couillault, Gérard; Vabres, Pierre; Le Pessot, Florence; Chapusot, Caroline; Malka, David; Bressac-de Paillerets, Brigitte; Tosi, Mario; Frebourg, Thierry

    2014-03-01

    Constitutional mismatch repair-deficiency, due to biallelic mutations of MMR genes, results in a tumour spectrum characterized by leukaemias, lymphomas, brain tumours and adenocarcinomas of the gastro-intestinal tract, occurring mostly in childhood. We report here two families illustrating the phenotypic diversity associated with biallelic MMR mutations. In the first family, two siblings developed six malignancies including glioblastoma, lymphoblastic T cell lymphoma, rectal and small bowel adenocarcinoma with onset as early as 6 years of age. We showed that this dramatic clinical presentation was due to the presence of two complex genomic PMS2 deletions in each patient predicted to result into complete PMS2 inactivation. In the second family, the index case presented with an early form of Lynch syndrome with colorectal adenocarcinomas at ages 17 and 20 years, and urinary tract tumours at the age of 25 years. We identified in this patient two MSH6 mutations corresponding to a frameshift deletion and an in frame deletion. The latter was not predicted to result into complete inactivation of MSH6. These reports show that the clinical expression of biallelic MMR mutations depends on the biological impact of the second MMR mutation and that, in clinical practice, the presence of a second MMR mutation located in trans should also be considered in patients suspected to present a Lynch syndrome with an unusual early-onset of tumours.

  3. Mismatch repair system (MMR) status correlates with response and survival in non-small cell lung cancer (NSCLC) patients.

    Science.gov (United States)

    Scartozzi, Mario; Franciosi, Vittorio; Campanini, Nicoletta; Benedetti, Giovanni; Barbieri, Fausto; Rossi, Giulio; Berardi, Rossana; Camisa, Roberta; Silva, Rosa Rita; Santinelli, Alfredo; Ardizzoni, Andrea; Crinò, Lucio; Rindi, Guido; Cascinu, Stefano

    2006-07-01

    Pre-clinical data suggested a relationship between inactivation of hMLH1 and hMSH2 and resistance to drugs like cisplatin and carboplatin, but not oxaliplatin. We then hypothesised that NSCLC showing loss of expression of the mismatch repair system (MMR), could be refractory to cisplatin-based, but not to oxaliplatin-based chemotherapy. Immunohistochemical expression of hMLH1 and hMSH2 was analysed on tumour samples from 93 advanced NSCLC, receiving chemotherapy with either cisplatin or oxaliplatin in combination with gemcitabine. Patients showing loss of hMLH1 or hMSH2 expression in > or = 50% of tumour cells were deemed MMR-negative (Group A), whereas cases with a normal hMLH1 or hMSH2 expression in > 50% of the tumour cells were defined MMR-positive (Group B). No differences in the response and progression rate were found in the whole patients population and in the gemcitabine/cisplatin group for both hMLH1 and hMSH2. In the gemcitabine/oxaliplatin group response rate was 38% and 0% (p=0.04) for patients with or without loss of hMSH2 expression. Median survival according to MMR status in Groups A and B, respectively was: 17 months versus 9 months for hMLH1 (p=0.031) and 10 months versus 9 months for hMSH2 (p=0.8330). Both the difference in response rate and in median survival observed according to MMR status seem to confirm what has been suggested by preclinical studies.

  4. Topoisomerase-1 and -2A gene copy numbers are elevated in mismatch repair-proficient colorectal cancers

    DEFF Research Database (Denmark)

    Sønderstrup, Ida Marie Heeholm; Nygård, Sune Boris; Poulsen, Tim Svenstrup

    2015-01-01

    (MMR) subtypes of CRC have been associated with benefit from adjuvant chemotherapy of primary CRC. Given the involvement of the topoisomerase enzymes in DNA replication and repair, we raised the hypothesis that an association may exist between TOP gene copy numbers and MMR proficiency/deficiency in CRC...... patients with deficient MMR (dMMR) CRC. TOP1 and TOP2A gene copy numbers and their ratios per nucleus were correlated with MMR status using the Mann-Whitney test. Validation cohort: FFPE samples from 154 patients with primary stage III CRC (originally included in the RANX05 study) were classified according...

  5. Higher occurrence of childhood cancer in families with germline mutations in BRCA2, MMR and CDKN2A genes

    DEFF Research Database (Denmark)

    Magnusson, S.; Borg, A.; Kristoffersson, U.

    2008-01-01

    The contribution of hereditary factors for development of childhood tumors is limited to some few known syndromes associated with predominance of tumors in childhood. Occurrence of childhood tumors in hereditary cancer syndromes such as BRCA1/2 associated breast and ovarian cancer, DNA-mismatch r......-mismatch repair (MMR) genes associated hereditary non polyposis colorectal cancer and CDKN2A associated familial malignant melanoma are very little studied. Herein we report the prevalence of childhood tumors (diagnosed......The contribution of hereditary factors for development of childhood tumors is limited to some few known syndromes associated with predominance of tumors in childhood. Occurrence of childhood tumors in hereditary cancer syndromes such as BRCA1/2 associated breast and ovarian cancer, DNA...

  6. Mismatch-mediated error prone repair at the immunoglobulin genes.

    Science.gov (United States)

    Chahwan, Richard; Edelmann, Winfried; Scharff, Matthew D; Roa, Sergio

    2011-12-01

    The generation of effective antibodies depends upon somatic hypermutation (SHM) and class-switch recombination (CSR) of antibody genes by activation induced cytidine deaminase (AID) and the subsequent recruitment of error prone base excision and mismatch repair. While AID initiates and is required for SHM, more than half of the base changes that accumulate in V regions are not due to the direct deamination of dC to dU by AID, but rather arise through the recruitment of the mismatch repair complex (MMR) to the U:G mismatch created by AID and the subsequent perversion of mismatch repair from a high fidelity process to one that is very error prone. In addition, the generation of double-strand breaks (DSBs) is essential during CSR, and the resolution of AID-generated mismatches by MMR to promote such DSBs is critical for the efficiency of the process. While a great deal has been learned about how AID and MMR cause hypermutations and DSBs, it is still unclear how the error prone aspect of these processes is largely restricted to antibody genes. The use of knockout models and mice expressing mismatch repair proteins with separation-of-function point mutations have been decisive in gaining a better understanding of the roles of each of the major MMR proteins and providing further insight into how mutation and repair are coordinated. Here, we review the cascade of MMR factors and repair signals that are diverted from their canonical error free role and hijacked by B cells to promote genetic diversification of the Ig locus. This error prone process involves AID as the inducer of enzymatically-mediated DNA mismatches, and a plethora of downstream MMR factors acting as sensors, adaptors and effectors of a complex and tightly regulated process from much of which is not yet well understood.

  7. Gene expression of the mismatch repair gene MSH2 in primary colorectal cancer

    DEFF Research Database (Denmark)

    Jensen, Lars Henrik; Kuramochi, Hidekazu; Crüger, Dorthe Gylling

    2011-01-01

    Microsatellite instability (MSI) is caused by defective mismatch repair (MMR) and is one of the very few molecular markers with proven clinical importance in colorectal cancer with respect to heredity, prognosis, and treatment effect. The gene expression of the MMR gene MSH2 may be a quantitative...... marker for the level of MMR and a potential molecular marker with clinical relevance. The aim was to investigate the gene expression of MSH2 in primary operable colorectal cancer in correlation with MSI, protein expression, and promoter hypermethylation. In a cohort of 210 patients, the primary tumor...... and lymphnode metastases were analyzed with immunohistochemistry, methylation and MSI analyses, and quantitative polymerase chain reaction (PCR). The median gene expression of MSH2 was 1.00 (range 0.16-11.2, quartiles 0.70-1.51) and there was good agreement between the gene expression in primary tumor and lymph...

  8. Risk of colorectal cancer for people with a mutation in both a MUTYH and a DNA mismatch repair gene

    Science.gov (United States)

    Win, Aung Ko; Reece, Jeanette C.; Buchanan, Daniel D.; Clendenning, Mark; Young, Joanne P.; Cleary, Sean P.; Kim, Hyeja; Cotterchio, Michelle; Dowty, James G.; MacInnis, Robert J.; Tucker, Katherine M.; Winship, Ingrid M.; Macrae, Finlay A.; Burnett, Terrilea; Le Marchand, Loïc; Casey, Graham; Haile, Robert W.; Newcomb, Polly A.; Thibodeau, Stephen N.; Lindor, Noralane M.; Hopper, John L.; Gallinger, Steven; Jenkins, Mark A.

    2015-01-01

    The base excision repair protein, MUTYH, functionally interacts with the DNA mismatch repair (MMR) system. As genetic testing moves from testing one gene at a time, to gene panel and whole exome next generation sequencing approaches, understanding the risk associated with co-existence of germline mutations in these genes will be important for clinical interpretation and management. From the Colon Cancer Family Registry, we identified 10 carriers who had both a MUTYH mutation (6 with c.1187G>A p.(Gly396Asp), 3 with c.821G>A p.(Arg274Gln), and 1 with c.536A>G p.(Tyr179Cys)) and a MMR gene mutation (3 in MLH1, 6 in MSH2, and 1 in PMS2), 375 carriers of a single (monoallelic) MUTYH mutation alone, and 469 carriers of a MMR gene mutation alone. Of the 10 carriers of both gene mutations, 8 were diagnosed with colorectal cancer. Using a weighted cohort analysis, we estimated that risk of colorectal cancer for carriers of both a MUTYH and a MMR gene mutation was substantially higher than that for carriers of a MUTYH mutation alone [hazard ratio (HR) 21.5, 95 % confidence interval (CI) 9.19–50.1; p colorectal cancer for carriers of a MMR gene mutation alone. Our finding suggests MUTYH mutation testing in MMR gene mutation carriers is not clinically informative. PMID:26202870

  9. Determining the functional significance of mismatch repair gene missense variants using biochemical and cellular assays

    DEFF Research Database (Denmark)

    Heinen, Christopher D; Juel Rasmussen, Lene

    2012-01-01

    provided an important experimental tool for studying the functional consequences of VUS. However, beyond this repair assay, a number of other experimental methods have been developed that allow us to test the effect of a VUS on discrete biochemical steps or other aspects of MMR function. Here, we describe......ABSTRACT: With the discovery that the hereditary cancer susceptibility disease Lynch syndrome (LS) is caused by deleterious germline mutations in the DNA mismatch repair (MMR) genes nearly 20 years ago, genetic testing can now be used to diagnose this disorder in patients. A definitive diagnosis...

  10. [Comparison of geno- and cytotoxicity of methylnitrosourea on MMR-proficient and MMR-deficient human tumor cell lines].

    Science.gov (United States)

    Tronov, V A; Kramarenko, I I; Smirnova, T D; Terekhov, S M

    2006-01-01

    Deficient mismatch repair (MMR) is identified as a mutation of one of four major MMR genes and(or) microsatellite instability. These genomic changes are used as markers of MMR status of the heredity nonpolyposis colorectal cancer (HNPCC) spectrum tumors--familial and sporadic tumors of colon and extracolonic cancers fulfilling Amsterdam clinical criteria II. MMR-deficiency results in mutator phenotype and resistance to geno- and cytotoxicity of alkylating agents. The main cytotoxic damage to DNA in response to chemical methylation is O6-methylguanine (O6-mG). The secondary DNA strand breaks, which are formed during the MMR functioning, are proposed to be required for methylation induced cytotoxicity. We have assumed that the secondary double stand breaks (DSB) upon DNA methylation are able to represent functional efficiency of MMR in cells. The purpose of the paper was to test this assumption on human tumor cells differing in MMR-status and pulse-treated with methylnitrosourea (MNU). We used 3 cell lines: HeLa (MMR-competent endometrial tumor cells), HCT116 (MMR-deficient colorectal carcinoma cells), and Colo320 (sigmoid intestine tumor cells with uncharacterized MMR status). DSBs were evaluated with neutral comet assay. Cytotoxicity/viability was evaluated with MTT-asay and apoptotic index (frequency of morphologically determined apoptotic cells). We show that 1) cytotoxic effect of MNU (250 microM) on HeLa cells was exhibited 3 days after pulse-treatment of cells with MNU; 2) DSBs occurred 48 h after the drug treatment but prior to the onset of apoptosis of HeLa cells; 3) MMR-deficient HCT116 cells were resistant to the drug: no decreased viability, DSBs and apoptosis were observed during 3 days after cell treatment. Both cell lines exhibited high sensitivity to etoposide, classical inductor of unrepairable DSBs and p53. Etoposide has been found to induce DSBs in 6-12 h, which was followed by apoptosis (in 24 h). Colo320 cells exhibited intermediate position

  11. A Database to Support the Interpretation of Human Mismatch Repair Gene Variants

    NARCIS (Netherlands)

    Ou, Jianghua; Niessen, Renee C.; Vonk, Jan; Westers, Helga; Hofstra, Robert M. W.; Sijmons, Rolf H.

    2008-01-01

    Germline mutations in the mismatch repair (MMR) genes MLH1, MSH2, MSH6, or PMS2 can cause Lynch syndrome. This syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC), is an autosomal dominantly-inherited disorder predominantly characterized by colorectal and endometrial cancer. Tr

  12. Approaches to diagnose DNA mismatch repair gene defects in cancer

    DEFF Research Database (Denmark)

    Peña-Diaz, Javier; Rasmussen, Lene Juel

    2016-01-01

    The DNA repair pathway mismatch repair (MMR) is responsible for the recognition and correction of DNA biosynthetic errors caused by inaccurate nucleotide incorporation during replication. Faulty MMR leads to failure to address the mispairs or insertion deletion loops (IDLs) left behind...... already been well defined and their pathogenicity assessed. Despite this substantial wealth of knowledge, the effects of a large number of alterations remain uncharacterized (variants of uncertain significance, VUSs). The advent of personalized genomics is likely to increase the list of VUSs found in MMR...

  13. Mutation mismatch repair gene deletions in diffuse large B-cell lymphoma.

    Science.gov (United States)

    Couronné, Lucile; Ruminy, Philippe; Waultier-Rascalou, Agathe; Rainville, Vinciane; Cornic, Marie; Picquenot, Jean-Michel; Figeac, Martin; Bastard, Christian; Tilly, Hervé; Jardin, Fabrice

    2013-05-01

    To further unravel the molecular pathogenesis of diffuse large B-cell lymphoma (DLBCL), we performed high-resolution comparative genomic hybridization on lymph node biopsies from 70 patients. With this strategy, we identified microdeletions of genes involved in the mutation mismatch repair (MMR) pathway in two samples. The first patient presented with a homozygous deletion of MSH2-MSH6 due to duplication of an unbalanced pericentric inversion of chromosome 2. The other case showed a PMS2 heterozygous deletion. PMS2 and MSH2-MSH6 abnormalities, respectively, resulted in a decrease and complete loss of gene expression. However, unlike tumors associated with the hereditary non-polyposis colorectal cancer syndrome or immunodeficiency-related lymphomas, no microsatellite instability was detected. Mutational profiles revealed especially in one patient an aberrant hypermutation without a clear activation-induced cytidine deaminase signature, indicating a breakdown of the high-fidelity repair in favor of the error-prone repair pathway. Our findings suggest that in a rare subset of patients, inactivation of the genes of the MMR pathway is likely an important step in the molecular pathogenesis of DLBCL and does not involve the same molecular mechanisms as other common neoplasms with MMR deficiency.

  14. Association between expression of DNA mismatch repair genes and clinical features and prognosis of patients with radical resection of colon cancer.

    Science.gov (United States)

    Wang, J B; Ma, D L; Li, J Y; Sun, Q D; Liu, Y E

    2016-08-19

    The aim of this study was to investigate the clinical significance of the expression of DNA mismatch repair (MMR) genes in patients subjected to radical surgical removal of colon cancer, as well as their correlation with disease prognosis. Ninety stage II and III colon cancer patients who received laparoscopic radical resection of colon cancer at our hospital were recruited in this study. The expression of hMLH1, hMSH2, hMSH6, and hPMS2 in the resected tumor tissues was examined by SP immunohistochemistry, in order to analyze the relationship between defective DNA MMR (dMMR) and the clinico-pathological features and prognosis of colon cancer. Patients were followed up over a period of 5-35 months, and the Kaplan-Meier survival curve was plotted. dMMR was confirmed in 27 subjects (30.0%), among whom recurrence with metastasis and death was reported in 5 (18.5%) and 2 (7.4%) patients, respectively. The remaining 63 subjects displayed proficient DNA MMR (pMMR); among these, 19 (30.2%) and 7 (11.1%) recurrences with metastasis and death were reported, respectively. dMMR showed no significant correlation with gender, age, or therapeutic modality (P > 0.05), but was significantly correlated with the degree of differentiation, tumor location, number of resected lymph nodes, presence of ileus, and TNM stage (P colon cancers.

  15. Non-DBS DNA Repair Genes Regulate Radiation-induced Cytogenetic Damage Repair and Cell Cycle Progression

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry H.; Emami, Kamal; Casey, Rachael; Wu, Honglu

    2008-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in DSB repair, and its impact on cytogenetic responses has not been systematically studied. In the present study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by transfection with small interfering RNA in human fibroblast cells. The purpose of this study is to identify new roles of these selected genes on regulating DSB repair and cell cycle progression , as measured in the micronuclei formation and chromosome aberration. In response to IR, the formation of MN was significantly increased by suppressed expression of 5 genes: Ku70 in the DSB repair pathway, XPA in the NER pathway, RPA1 in the MMR pathway, and RAD17 and RBBP8 in cell cycle control. Knocked-down expression of 4 genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Furthermore, loss of XPA, P21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Most of the 11 genes that affected cytogenetic responses are not known to have clear roles influencing DBS repair. Nine of these 11 genes were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate the biological consequences after IR.

  16. Non-DBS DNA Repair Genes Regulate Radiation-induced Cytogenetic Damage Repair and Cell Cycle Progression

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry H.; Emami, Kamal; Casey, Rachael; Wu, Honglu

    2008-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in DSB repair, and its impact on cytogenetic responses has not been systematically studied. In the present study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by transfection with small interfering RNA in human fibroblast cells. The purpose of this study is to identify new roles of these selected genes on regulating DSB repair and cell cycle progression , as measured in the micronuclei formation and chromosome aberration. In response to IR, the formation of MN was significantly increased by suppressed expression of 5 genes: Ku70 in the DSB repair pathway, XPA in the NER pathway, RPA1 in the MMR pathway, and RAD17 and RBBP8 in cell cycle control. Knocked-down expression of 4 genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Furthermore, loss of XPA, P21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Most of the 11 genes that affected cytogenetic responses are not known to have clear roles influencing DBS repair. Nine of these 11 genes were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate the biological consequences after IR.

  17. Role of APC and DNA mismatch repair genes in the development of colorectal cancers

    Directory of Open Access Journals (Sweden)

    Roy Deodutta

    2003-12-01

    Full Text Available Abstract Colorectal cancer is the third most common cause of cancer-related death in both men and women in the western hemisphere. According to the American Cancer Society, an estimated 105,500 new cases of colon cancer with 57,100 deaths will occur in the U.S. in 2003, accounting for about 10% of cancer deaths. Among the colon cancer patients, hereditary risk contributes approximately 20%. The main inherited colorectal cancers are the familial adenomatous polyposis (FAP and the hereditary nonpolyposis colorectal cancers (HNPCC. The FAP and HNPCC are caused due to mutations in the adenomatous polyposis coli (APC and DNA mismatch repair (MMR genes. The focus of this review is to summarize the functions of APC and MMR gene products in the development of colorectal cancers.

  18. Mismatch repair-deficient crypt foci in Lynch syndrome--molecular alterations and association with clinical parameters.

    Directory of Open Access Journals (Sweden)

    Laura Staffa

    Full Text Available Lynch syndrome is caused by germline mutations of DNA mismatch repair (MMR genes, most frequently MLH1 and MSH2. Recently, MMR-deficient crypt foci (MMR-DCF have been identified as a novel lesion which occurs at high frequency in the intestinal mucosa from Lynch syndrome mutation carriers, but very rarely progress to cancer. To shed light on molecular alterations and clinical associations of MMR-DCF, we systematically searched the intestinal mucosa from Lynch syndrome patients for MMR-DCF by immunohistochemistry. The identified lesions were characterised for alterations in microsatellite-bearing genes with proven or suspected role in malignant transformation. We demonstrate that the prevalence of MMR-DCF (mean 0.84 MMR-DCF per 1 cm2 mucosa in the colorectum of Lynch syndrome patients was significantly associated with patients' age, but not with patients' gender. No MMR-DCF were detectable in the mucosa of patients with sporadic MSI-H colorectal cancer (n = 12. Microsatellite instability of at least one tested marker was detected in 89% of the MMR-DCF examined, indicating an immediate onset of microsatellite instability after MMR gene inactivation. Coding microsatellite mutations were most frequent in the genes HT001 (ASTE1 with 33%, followed by AIM2 (17% and BAX (10%. Though MMR deficiency alone appears to be insufficient for malignant transformation, it leads to measurable microsatellite instability even in single MMR-deficient crypts. Our data indicate for the first time that the frequency of MMR-DCF increases with patients' age. Similar patterns of coding microsatellite instability in MMR-DCF and MMR-deficient cancers suggest that certain combinations of coding microsatellite mutations, including mutations of the HT001, AIM2 and BAX gene, may contribute to the progression of MMR-deficient lesions into MMR-deficient cancers.

  19. Measles, Mumps, Rubella (MMR)

    Science.gov (United States)

    ... at Each Vaccine: MMR (Measles, Mumps and Rubella) Vaccine Children's Hospital of Philadelphia (CHOP): Learn about measles, how ... Disease Control and Prevention AAP Urges Parents to Vaccinate Children to Protect Against Measles (1/23/15) American ...

  20. Identification of mismatch repair gene mutations in young patients with colorectal cancer and in patients with multiple tumours associated with hereditary non-polyposis colorectal cancer

    NARCIS (Netherlands)

    Niessen, R C; Berends, M J W; Wu, Y; Sijmons, R H; Hollema, H; Ligtenberg, M J L; de Walle, H E K; de Vries, E G E; Karrenbeld, A; Buys, C H C M; van der Zee, A G J; Hofstra, R M W; Kleibeuker, J H

    2006-01-01

    Background: Patients with early-onset colorectal cancer (CRC) or those with multiple tumours associated with hereditary non-polyposis colorectal cancer (HNPCC) raise suspicion of the presence of germline DNA mismatch repair (MMR) gene mutations. Aim: To analyse the value of family history,

  1. Identification of mismatch repair gene mutations in young patients with colorectal cancer and in patients with multiple tumours associated with hereditary non-polyposis colorectal cancer.

    NARCIS (Netherlands)

    Niessen, R.C.; Berends, M.J.; Wu, Y.; Sijmons, R.H.; Hollema, H.; Ligtenberg, M.J.L.; Walle, H.E. de; Vries, E.G.F. de; Karrenbeld, A.; Buys, C.H.C.M.; Zee, A.G. van der; Hofstra, R.M.; Kleibeuker, J.H.

    2006-01-01

    BACKGROUND: Patients with early-onset colorectal cancer (CRC) or those with multiple tumours associated with hereditary non-polyposis colorectal cancer (HNPCC) raise suspicion of the presence of germline DNA mismatch repair (MMR) gene mutations. AIM: To analyse the value of family history,

  2. Cancer risk and survival in path_MMR carriers by gene and gender up to 75 years of age

    DEFF Research Database (Denmark)

    Møller, Pål; Seppälä, Toni; Bernstein, Inge

    2017-01-01

    : This observational, international, multicentre study aimed to determine prospectively observed incidences of cancers and survival in path_MMR carriers up to 75 years of age. RESULTS: 3119 patients were followed for a total of 24 475 years. Cumulative incidences at 75 years (risks) for colorectal cancer were 46%, 43......% and 18%; and for brain tumours 1%, 5% and 1%, respectively. Ovarian cancer occurred mainly premenopausally. By contrast, upper gastrointestinal, urinary tract and prostate cancers occurred predominantly at older ages. Overall 5-year survival for prostate cancer was 100%, urinary bladder 93%, ureter 85......%, duodenum 67%, stomach 61%, bile duct 29%, brain 22% and pancreas 0%. Path_PMS2 carriers had lower risk for cancer. CONCLUSION: Carriers of different path_MMR variants exhibit distinct patterns of cancer risk and survival as they age. Risk estimates for counselling and planning of surveillance and treatment...

  3. Comparative analysis of meiotic progression in female mice bearing mutations in genes of the DNA mismatch repair pathway.

    Science.gov (United States)

    Kan, Rui; Sun, Xianfei; Kolas, Nadine K; Avdievich, Elena; Kneitz, Burkhard; Edelmann, Winfried; Cohen, Paula E

    2008-03-01

    The DNA mismatch repair (MMR) family functions in a variety of contexts to preserve genome integrity in most eukaryotes. In particular, members of the MMR family are involved in the process of meiotic recombination in germ cells. MMR gene mutations in mice result in meiotic disruption during prophase I, but the extent of this disruption often differs between male and female meiocytes. To address the role of MMR proteins specifically in female meiosis, we explored the progression of oocytes through prophase I and the meiotic divisions in mice harboring deletions in members of the MMR pathway (Mlh1, Mlh3, Exo1, and an ATPase-deficient variant of Mlh1, Mlh1(G67R)). The colocalization of MLH1 and MLH3, key proteins involved in stabilization of nascent crossovers, was dependent on intact heterodimer formation and was highly correlated with the ability of oocytes to progress through to metaphase II. The exception was Exo1(-/-) oocytes, in which normal MLH1/MLH3 localization was observed followed by failure to proceed to metaphase II. All mutant oocytes were able to resume meiosis after dictyate arrest, but they showed a dramatic decline in chiasmata (to less than 25% of normal), accompanied by varied progression through metaphase I. Taken together, these results demonstrate that MMR function is required for the formation and stabilization of crossovers in mammalian oocytes and that, in the absence of a functional MMR system, the failure to maintain chiasmata results in a reduced ability to proceed normally through the first and second meiotic divisions, despite near-normal levels of meiotic resumption after dictyate arrest.

  4. Prognostic impact of mismatch repair genes germline defects in colorectal cancer patients: are all mutations equal?

    Science.gov (United States)

    Maccaroni, Elena; Bracci, Raffaella; Giampieri, Riccardo; Bianchi, Francesca; Belvederesi, Laura; Brugiati, Cristiana; Pagliaretta, Silvia; Del Prete, Michela; Scartozzi, Mario; Cascinu, Stefano

    2015-01-01

    Background Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRC) syndrome, caused by germline mutations in MisMatch Repair (MMR) genes, particularly in MLH1, MSH2 and MSH6. Patients with LS seem to have a more favourable prognosis than those with sporadic CRC, although the prognostic impact of different mutation types is unknown. Aim of our study is to compare survival outcomes of different types of MMR mutations in patients with LS-related CRC. Methods 302 CRC patients were prospectively selected on the basis of Amsterdam or Revised Bethesda criteria to undergo genetic testing: direct sequencing of DNA and MLPA were used to examine the entire MLH1, MSH2 and MSH6 coding sequence. Patients were classified as mutation-positive or negative according to the genetic testing result. Results A deleterious MMR mutation was found in 38/302 patients. Median overall survival (OS) was significantly higher in mutation-positive vs mutation-negative patients (102.6 vs 77.7 months, HR:0.63, 95%CI:0.46–0.89, p = 0.0083). Different types of mutation were significantly related with OS: missense or splicing-site mutations were associated with better OS compared with rearrangement, frameshift or non-sense mutations (132.5 vs 82.5 months, HR:0.46, 95%CI:0.16–0.82, p = 0.0153). Conclusions Our study confirms improved OS for LS-patients compared with mutation-negative CRC patients. In addition, not all mutations could be considered equal: the better prognosis in CRC patients with MMR pathogenic missense or splicing site mutation could be due to different functional activity of the encoded MMR protein. This matter should be investigated by use of functional assays in the future. PMID:26485756

  5. Zebrafish with mutations in mismatch repair genes develop neurofibromas and other tumors.

    NARCIS (Netherlands)

    Feitsma, H.; Kuiper, R.V.; Korving, J.; Nijman, I.J.; Cuppen, E.

    2008-01-01

    Defective mismatch repair (MMR) in humans causes hereditary nonpolyposis colorectal cancer. This genetic predisposition to colon cancer is linked to heterozygous familial mutations, and loss-of-heterozygosity is necessary for tumor development. In contrast, the rare cases with biallelic MMR

  6. Endometrial tumour BRAF mutations and MLH1 promoter methylation as predictors of germline mismatch repair gene mutation status: a literature review.

    Science.gov (United States)

    Metcalf, Alexander M; Spurdle, Amanda B

    2014-03-01

    Colorectal cancer (CRC) that displays high microsatellite instability (MSI-H) can be caused by either germline mutations in mismatch repair (MMR) genes, or non-inherited transcriptional silencing of the MLH1 promoter. A correlation between MLH1 promoter methylation, specifically the 'C' region, and BRAF V600E status has been reported in CRC studies. Germline MMR mutations also greatly increase risk of endometrial cancer (EC), but no systematic review has been undertaken to determine if these tumour markers may be useful predictors of MMR mutation status in EC patients. Endometrial cancer cohorts meeting review inclusion criteria encompassed 2675 tumours from 20 studies for BRAF V600E, and 447 tumours from 11 studies for MLH1 methylation testing. BRAF V600E mutations were reported in 4/2675 (0.1%) endometrial tumours of unknown MMR mutation status, and there were 7/823 (0.9%) total sequence variants in exon 11 and 27/1012 (2.7%) in exon 15. Promoter MLH1 methylation was not observed in tumours from 32 MLH1 mutation carriers, or for 13 MSH2 or MSH6 mutation carriers. MMR mutation-negative individuals with tumour MLH1 and PMS2 IHC loss displayed MLH1 methylation in 48/51 (94%) of tumours. We have also detailed specific examples that show the importance of MLH1 promoter region, assay design, and quantification of methylation. This review shows that BRAF mutations occurs so infrequently in endometrial tumours they can be discounted as a useful marker for predicting MMR-negative mutation status, and further studies of endometrial cohorts with known MMR mutation status are necessary to quantify the utility of tumour MLH1 promoter methylation as a marker of negative germline MMR mutation status in EC patients.

  7. Targeted gene repair – in the arena

    OpenAIRE

    2003-01-01

    The development of targeted gene repair is under way and, despite some setbacks, shows promise as an alternative form of gene therapy. This approach uses synthetic DNA molecules to activate and direct the cell’s inherent DNA repair systems to correct inborn errors. The progress of this technique and its therapeutic potential are discussed in relation to the treatment of genetic diseases.

  8. Diagnosis of Constitutional Mismatch Repair-Deficiency Syndrome Based on Microsatellite Instability and Lymphocyte Tolerance to Methylating Agents

    DEFF Research Database (Denmark)

    Bodo, Sahra; Colas, Chrystelle; Buhard, Olivier

    2015-01-01

    BACKGROUND & AIMS: Patients with bi-allelic germline mutations in mismatch repair (MMR) genes (MLH1, MSH2, MSH6, or PMS2) develop a rare but severe variant of Lynch syndrome called constitutional MMR deficiency (CMMRD). This syndrome is characterized by early-onset colorectal cancers, lymphomas o...

  9. A study of molecular signals deregulating mismatch repair genes in prostate cancer compared to benign prostatic hyperplasia.

    Science.gov (United States)

    Basu, Sanmitra; Majumder, Subhadipa; Bhowal, Ankur; Ghosh, Alip; Naskar, Sukla; Nandy, Sumit; Mukherjee, Subhabrata; Sinha, Rajan Kumar; Basu, Keya; Karmakar, Dilip; Banerjee, Soma; Sengupta, Sanghamitra

    2015-01-01

    Prostate cancer is one of the leading causes of mortality among aging males. There is an unmet requirement of clinically useful biomarkers for early detection of prostate cancer to reduce the liabilities of overtreatment and accompanying morbidity. The present population-based study investigates the factors disrupting expression of multiple functionally related genes of DNA mismatch repair pathway in prostate cancer patients to identify molecular attributes distinguishing adenocarcinoma from benign hyperplasia of prostate. Gene expression was compared between tissue samples from prostate cancer and benign prostatic hyperplasia using real-time-PCR, western blot and immunohistochemistry. Assessment of genotypes of seven single-nucleotide-polymorphisms of three MMR genes was conducted using PCR-coupled RFLP and sequencing. Promoter methylation was interrogated by methylation-specific-PCR and bisulfite-sequencing. Interaction between microRNAs and MMR genes was verified by 3'UTR-based dual luciferase assays. Concurrent reduction of three MMR genes namely hMLH1, hMSH6 and hMSH2 (34-85%, Pprostate cancer tissues. hMSH6 polymorphism rs1800932(Pro92Pro) conferred a borderline protection in cancer patients (OR = 0.33, 95% CI = 0.15-0.75). Relative transcript level of hMLH1 was inversely related (r = -0.59, Pprostate cancer. This comparative study reflects that microRNA expression level, particularly hsa-miR-155, exhibits predictive signature of prostate adenocarcinoma.

  10. The CREB Coactivator CRTC2 is a Lymphoma Tumor Suppressor that Preserves Genome Integrity Through Transcription of DNA Mismatch Repair Genes

    Science.gov (United States)

    Fang, Minggang; Pak, Magnolia L.; Chamberlain, Lynn; Xing, Wei; Yu, Hongbo; Green, Michael R.

    2015-01-01

    SUMMARY The CREB-regulated transcription coactivator CRTC2 stimulates CREB target gene expression and has a well-established role in modulating glucose and lipid metabolism. Here we find, unexpectedly, that loss of CRTC2, as well as CREB1 and its coactivator CREB-binding protein (CBP), results in a deficiency in DNA mismatch repair (MMR) and a resultant increased mutation frequency. We show that CRTC2, CREB1 and CBP are transcriptional activators of well-established MMR genes, including EXO1, MSH6, PMS1 and POLD2. Mining of expression profiling databases and analysis of patient samples reveal that CRTC2 and its target MMR genes are down-regulated in specific T-cell lymphoma subtypes, which are microsatellite unstable. The levels of acetylated histone H3 on the CRTC2 promoter are significantly reduced in lymphoma compared to normal tissue, explaining the decreased CRTC2 expression. Our results establish a role for CRTC2 as a lymphoma tumor suppressor gene that preserves genome integrity by stimulating transcription of MMR genes. PMID:26004186

  11. MMR: risk, choice, chance.

    Science.gov (United States)

    Fitzpatrick, Michael

    2004-01-01

    The unfolding of the measles, mumps and rubella (MMR) controversy reveals some of the key features of the cultural climate affecting matters of health and illness in contemporary society. A high level of anxiety around issues of health is reflected in a heightened sense of individual vulnerability to environmental dangers (such as atmospheric pollution, electromagnetic fields, bioterrorism) and in a general aversion to risk, particularly in relation to children. This mood has proved responsive to views sceptical, if not hostile, towards science and medicine and associated professionals, particularly in the sphere of immunization. The result is that uptake of MMR vaccination in the UK has fallen, from a peak of 92% in the mid-1990s to a national level of 82% in 2003 (at the age of two); in London uptake is now less than 75%-much less in some areas-causing a significant risk of outbreaks of measles. In the USA too, the proportion of parents opting out of regulations requiring immunization as a condition of school entry has increased significantly in some areas, though these controversies appear to have had little impact so far in continental Europe.

  12. Clinical problems of colorectal cancer and endometrial cancer cases with unknown cause of tumor mismatch repair deficiency (suspected Lynch syndrome

    Directory of Open Access Journals (Sweden)

    Buchanan DD

    2014-10-01

    Full Text Available Daniel D Buchanan,1,2 Christophe Rosty,1,3,4 Mark Clendenning,1 Amanda B Spurdle,5 Aung Ko Win2 1Oncogenomics Group, Genetic Epidemiology Laboratory, Department of Pathology, The University of Melbourne, Parkville, VIC, Australia; 2Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, VIC, Australia; 3Envoi Specialist Pathologists, Herston, QLD, Australia; 4School of Medicine, University of Queensland, Herston, QLD, Australia; 5Molecular Cancer Epidemiology Laboratory, Genetics and Computational Biology Division, QIMR Berghofer Medical Research Institute, Herston, QLD, AustraliaAbstract: Carriers of a germline mutation in one of the DNA mismatch repair (MMR genes have a high risk of developing numerous different cancers, predominantly colorectal cancer and endometrial cancer (known as Lynch syndrome. MMR gene mutation carriers develop tumors with MMR deficiency identified by tumor microsatellite instability or immunohistochemical loss of MMR protein expression. Tumor MMR deficiency is used to identify individuals most likely to carry an MMR gene mutation. However, MMR deficiency can also result from somatic inactivation, most commonly methylation of the MLH1 gene promoter. As tumor MMR testing of all incident colorectal and endometrial cancers (universal screening is becoming increasingly adopted, a growing clinical problem is emerging for individuals who have tumors that show MMR deficiency who are subsequently found not to carry an MMR gene mutation after genetic testing using the current diagnostic approaches (Sanger sequencing and multiplex ligation-dependent probe amplification and who also show no evidence of MLH1 methylation. The inability to determine the underlying cause of tumor MMR deficiency in these "Lynch-like" or "suspected Lynch syndrome" cases has significant implications on the clinical management of these individuals and their relatives. When the

  13. Evaluating the performance of clinical criteria for predicting mismatch repair gene mutations in Lynch syndrome: a comprehensive analysis of 3,671 families.

    Science.gov (United States)

    Steinke, Verena; Holzapfel, Stefanie; Loeffler, Markus; Holinski-Feder, Elke; Morak, Monika; Schackert, Hans K; Görgens, Heike; Pox, Christian; Royer-Pokora, Brigitte; von Knebel-Doeberitz, Magnus; Büttner, Reinhard; Propping, Peter; Engel, Christoph

    2014-07-01

    Carriers of mismatch repair (MMR) gene mutations have a high lifetime risk for colorectal and endometrial cancers, as well as other malignancies. As mutation analysis to detect these patients is expensive and time-consuming, clinical criteria and tumor-tissue analysis are widely used as pre-screening methods. The aim of our study was to evaluate the performance of commonly applied clinical criteria (the Amsterdam I and II Criteria, and the original and revised Bethesda Guidelines) and the results of tumor-tissue analysis in predicting MMR gene mutations. We analyzed 3,671 families from the German HNPCC Registry and divided them into nine mutually exclusive groups with different clinical criteria. A total of 680 families (18.5%) were found to have a pathogenic MMR gene mutation. Among all 1,284 families with microsatellite instability-high (MSI-H) colorectal cancer, the overall mutation detection rate was 53.0%. Mutation frequencies and their distribution between the four MMR genes differed significantly between clinical groups (p small-bowel cancer (p small-bowel cancer were clinically relevant predictors for Lynch syndrome. © 2013 UICC.

  14. DNA repair genes in the Megavirales pangenome.

    Science.gov (United States)

    Blanc-Mathieu, Romain; Ogata, Hiroyuki

    2016-06-01

    The order 'Megavirales' represents a group of eukaryotic viruses with a large genome encoding a few hundred up to two thousand five hundred genes. Several members of Megavirales possess genes involved in major DNA repair pathways. Some of these genes were likely inherited from an ancient virus world and some others were derived from the genomes of their hosts. Here we examine molecular phylogenies of key DNA repair enzymes in light of recent hypotheses on the origin of Megavirales, and propose that the last common ancestors of the individual families of the order Megavirales already possessed DNA repair functions to achieve and maintain a moderately large genome and that this repair capacity gradually increased, in a family-dependent manner, during their recent evolution.

  15. Association of common variants in mismatch repair genes and breast cancer susceptibility: a multigene study

    Directory of Open Access Journals (Sweden)

    Pina Julieta

    2009-09-01

    Full Text Available Abstract Background MMR is responsible for the repair of base-base mismatches and insertion/deletion loops. Besides this, MMR is also associated with an anti-recombination function, suppressing homologous recombination. Losses of heterozygosity and/or microsatellite instability have been detected in a large number of skin samples from breast cancer patients, suggesting a potential role of MMR in breast cancer susceptibility. Methods We carried out a hospital-based case-control study in a Caucasian Portuguese population (287 cases and 547 controls to estimate the susceptibility to non-familial breast cancer associated with some polymorphisms in mismatch repair genes (MSH3, MSH4, MSH6, MLH1, MLH3, PMS1 and MUTYH. Results Using unconditional logistic regression we found that MLH3 (L844P, G>A polymorphism GA (Leu/Pro and AA (Pro/Pro genotypes were associated with a decreased risk: OR = 0.65 (0.45-0.95 (p = 0.03 and OR = 0.62 (0.41-0.94 (p = 0.03, respectively. Analysis of two-way SNP interaction effects on breast cancer revealed two potential associations to breast cancer susceptibility: MSH3 Ala1045Thr/MSH6 Gly39Glu - AA/TC [OR = 0.43 (0.21-0.83, p = 0.01] associated with a decreased risk; and MSH4 Ala97Thr/MLH3 Leu844Pro - AG/AA [OR = 2.35 (1.23-4.49, p = 0.01], GG/AA [OR = 2.11 (1.12-3,98, p = 0.02], and GG/AG [adjusted OR = 1.88 (1.12-3.15, p = 0.02] all associated with an increased risk for breast cancer. Conclusion It is possible that some of these common variants in MMR genes contribute significantly to breast cancer susceptibility. However, further studies with a large sample size will be needed to support our results.

  16. Transactivation of repair genes by BRCA1.

    Science.gov (United States)

    El-Deiry, Wafik S

    2002-01-01

    Recent studies have identified a link between the BRCA1 tumor suppressor and transcriptional regulation of a group of genes involved in nucleotide excision repair. There is some controversy regarding the precise mechanism of upregulation of XPE DDB2 or XPC by BRCA1, with some evidence suggesting that p53 is involved in their regulation. Some evidence suggests BRCA1 may stabilize p53 and direct regulation of DNA repair genes, although how BRCA1 stabilizes p53 remains unclear and whether BRCA1 can upregulate DNA repair genes in a p53-independent manner remains a possibility. A transcriptional component to the action of BRCA1 and involvement of XP genes brings up new and interesting questions about breast cancer development and therapy.

  17. A study of molecular signals deregulating mismatch repair genes in prostate cancer compared to benign prostatic hyperplasia.

    Directory of Open Access Journals (Sweden)

    Sanmitra Basu

    Full Text Available Prostate cancer is one of the leading causes of mortality among aging males. There is an unmet requirement of clinically useful biomarkers for early detection of prostate cancer to reduce the liabilities of overtreatment and accompanying morbidity. The present population-based study investigates the factors disrupting expression of multiple functionally related genes of DNA mismatch repair pathway in prostate cancer patients to identify molecular attributes distinguishing adenocarcinoma from benign hyperplasia of prostate. Gene expression was compared between tissue samples from prostate cancer and benign prostatic hyperplasia using real-time-PCR, western blot and immunohistochemistry. Assessment of genotypes of seven single-nucleotide-polymorphisms of three MMR genes was conducted using PCR-coupled RFLP and sequencing. Promoter methylation was interrogated by methylation-specific-PCR and bisulfite-sequencing. Interaction between microRNAs and MMR genes was verified by 3'UTR-based dual luciferase assays. Concurrent reduction of three MMR genes namely hMLH1, hMSH6 and hMSH2 (34-85%, P<0.05 was observed in prostate cancer tissues. hMSH6 polymorphism rs1800932(Pro92Pro conferred a borderline protection in cancer patients (OR = 0.33, 95% CI = 0.15-0.75. Relative transcript level of hMLH1 was inversely related (r = -0.59, P<0.05 with methylation quotient of its promoter which showed a significantly higher methylation density (P = 0.008, Z = -2.649 in cancer patients. hsa-miR-155, hsa-miR-141 and hsa-miR-21 gene expressions were significantly elevated (66-85%, P<0.05 in tumor specimens and negatively correlated (r = -0.602 to -0.527, P<0.05 with that of MMR genes. hsa-miR-155 & hsa-miR-141 and hsa-miR-155 & hsa-miR-21 were demonstrated to bind to their putative seed sequences in hMLH1 and hMSH6 3'UTRs respectively. Relatively higher expression of DNA methyl-transferases (DNMT1 and DNMT3b and HIF-1α genes (34-50%, P<0.05 were also detected in tumor

  18. Immunohistochemical expression of mismatch repair genes: A screening tool for predicting mutator phenotype in liver fluke infection-associated intrahepatic cholangiocarcinoma

    Institute of Scientific and Technical Information of China (English)

    Upama Liengswangwong; Anant Karalak; Yukio Morishita; Masayuki Noguchi; Thiravud Khuhaprema; Petcharin Srivatanakul; Masanao Miwa

    2006-01-01

    AIM: To clarify possible contributions of DNA mismatch repair (MMR) system in carcinogenesis of liver fluke infection-associated intrahepatic cholangiocarcinoma (ICC) by using immunohistochemical assay.METHODS: A total of 29 ICC samples, which had been assessed for genomic instability by a PCR-based method, were used for study. They were examined immunohistochemically to demonstrate protein expression of two MMR genes, hMSH2 and hMLH1.Results obtained were compared with their mutator phenotype assessed previously.RESULTS: Either hMSH2or hMLH1 protein was obviously expressed in 28 of 29 (96.6%) ICC samples.Positive nuclear localization of hMSH2 or hMLH1 protein was observed in 86.2% (25/29) or 93.1% (27/29) ICC cases, respectively, while their negative nuclear reactivity was only detected in 13.8% (4/29) or 6.9% (2/29) ICC cases analyzed, respectively.CONCLUSION: Our study, probably for the first time,showed through immunohistochemical detection of hMSH2 and hMLH1 gene that DNA MMR system does not play a prominent role in liver fluke infection-associated cholangiocarcinogenesis. These results confirm previous findings on mutational status of these genes assessed through a PCR-based method. The immunohistochemical analysis has proven to be an effective and sensitive approach for screening MMR deficiency regardless of somatic inactivation or promoter hypermethylation of hMSH2 and/or hMLH1 gene. Furthermore,immunohistochemistry is more advantageous compared to mutator phenotyping assay in terms of simplicity,less time consuming and cost effectiveness for screening possible involvements of target MMR genes in tumorigenesis.

  19. Homologous and homeologous intermolecular gene conversion are not differentially affected by mutations in the DNA damage or the mismatch repair genes RAD1, RAD50, RAD51, RAD52, RAD54, PMS1 and MSH2

    Energy Technology Data Exchange (ETDEWEB)

    Porter, G.; Westmoreland, J.; Priebe, S. [National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States)] [and others

    1996-06-01

    Mismatch repair (MMR) genes or genes involved in both DNA damage repair and homologous recombination might affect homeologous vs. homologous recombination differentially. Spontaneous mitotic gene conversion between a chromosome and a homologous or homeologous donor sequence (14% diverged) on a single copy plasmid was examined in wild-type Saccharomyces cerevisiae strains and in MMR or DNA damage repair mutants. Homologous recombination in rad51, rad52 and rad54 mutants was considerably reduced, while there was little effect of rad1, rad50, pms1 and msh2 null mutations. DNA divergence resulted in no differential effect on recombination rates in the wild type or the mutants; there was only a five- to 10-fold reduction in homeologous relative to homologous recombination regardless of background. Since DNA divergence is known to affect recombination in some systems, we propose that differences in the role of MMR depends on the mode of recombination and/or the level of divergence. Based on analysis of the recombination breakpoints, there is a minimum of three homologous bases required at a recombination junction. A comparison of Rad{sup +} vs. rad52 strains revealed that while all conversion tracts are continuous, elimination of RAD52 leads to the appearance of a novel class of very short conversion tracts. 67 refs., 5 figs., 4 tabs.

  20. MMR Vaccination and Febrile Seizures

    DEFF Research Database (Denmark)

    Vestergaard, Mogens; Hviid, Anders; Madsen, Kreesten Meldgaard

    2004-01-01

    CONTEXT: The rate of febrile seizures increases following measles, mumps, and rubella (MMR) vaccination but it is unknown whether the rate varies according to personal or family history of seizures, perinatal factors, or socioeconomic status. Furthermore, little is known about the long-term outcome...... of febrile seizures following vaccination. OBJECTIVES: To estimate incidence rate ratios (RRs) and risk differences of febrile seizures following MMR vaccination within subgroups of children and to evaluate the clinical outcome of febrile seizures following vaccination. DESIGN, SETTING, AND PARTICIPANTS......: Incidence of first febrile seizure, recurrent febrile seizures, and subsequent epilepsy. RESULTS: A total of 439,251 children (82%) received MMR vaccination and 17,986 children developed febrile seizures at least once; 973 of these febrile seizures occurred within 2 weeks of MMR vaccination. The RR...

  1. Alcohol Consumption and the Risk of Colorectal Cancer for Mismatch Repair Gene Mutation Carriers.

    Science.gov (United States)

    Dashti, S Ghazaleh; Buchanan, Daniel D; Jayasekara, Harindra; Ait Ouakrim, Driss; Clendenning, Mark; Rosty, Christophe; Winship, Ingrid M; Macrae, Finlay A; Giles, Graham G; Parry, Susan; Casey, Graham; Haile, Robert W; Gallinger, Steven; Le Marchand, Loïc; Thibodeau, Stephen N; Lindor, Noralane M; Newcomb, Polly A; Potter, John D; Baron, John A; Hopper, John L; Jenkins, Mark A; Win, Aung Ko

    2017-03-01

    Background: People with germline mutation in one of the DNA mismatch repair (MMR) genes have increased colorectal cancer risk. For these high-risk people, study findings of the relationship between alcohol consumption and colorectal cancer risk have been inconclusive.Methods: 1,925 MMR gene mutations carriers recruited into the Colon Cancer Family Registry who had completed a questionnaire on lifestyle factors were included. Weighted Cox proportional hazard regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between alcohol consumption and colorectal cancer.Results: Colorectal cancer was diagnosed in 769 carriers (40%) at a mean (SD) age of 42.6 (10.3) years. Compared with abstention, ethanol consumption from any alcoholic beverage up to 14 g/day and >28 g/day was associated with increased colorectal cancer risk (HR, 1.50; 95% CI, 1.09-2.07 and 1.69; 95% CI, 1.07-2.65, respectively; Ptrend = 0.05), and colon cancer risk (HR, 1.78; 95% CI, 1.27-2.49 and 1.94; 95% CI, 1.19-3.18, respectively; Ptrend = 0.02). However, there was no clear evidence for an association with rectal cancer risk. Also, there was no evidence for associations between consumption of individual alcoholic beverage types (beer, wine, spirits) and colorectal, colon, or rectal cancer risk.Conclusions: Our data suggest that alcohol consumption, particularly more than 28 g/day of ethanol (∼2 standard drinks of alcohol in the United States), is associated with increased colorectal cancer risk for MMR gene mutation carriers.Impact: Although these data suggested that alcohol consumption in MMR carriers was associated with increased colorectal cancer risk, there was no evidence of a dose-response, and not all types of alcohol consumption were associated with increased risk. Cancer Epidemiol Biomarkers Prev; 26(3); 366-75. ©2016 AACR. ©2016 American Association for Cancer Research.

  2. Genetic screens to identify pathogenic gene variants in the common cancer predisposition Lynch syndrome

    DEFF Research Database (Denmark)

    Drost, Mark; Lützen, Anne; van Hees, Sandrine

    2013-01-01

    In many individuals suspected of the common cancer predisposition Lynch syndrome, variants of unclear significance (VUS), rather than an obviously pathogenic mutations, are identified in one of the DNA mismatch repair (MMR) genes. The uncertainty of whether such VUS inactivate MMR, and therefore...... for the translation of personalized genomics into targeted healthcare....

  3. Gene Therapy for Fracture Repair

    Science.gov (United States)

    2007-05-01

    case, the external catheter hub is visible (D), though the internal tubing cannot be visualized by X-Ray. 11 MLV-based vector with BMP-2/4...catheter) injection. Top: A fluoroscope was used to visualize a radio- opaque contrast dye during a percutaneous injection from the lateral aspect...analysis was performed using ImaGene software (BioDiscovery, El Segundo, CA), that used an internal statistical analysis of the signal intensity of

  4. Distinct Gene Expression Signatures in Lynch Syndrome and Familial Colorectal Cancer Type X

    DEFF Research Database (Denmark)

    Valentin, Mev; Therkildsen, Christina; Veerla, Srinivas;

    2013-01-01

    Heredity is estimated to cause at least 20% of colorectal cancer. The hereditary nonpolyposis colorectal cancer subset is divided into Lynch syndrome and familial colorectal cancer type X (FCCTX) based on presence of mismatch repair (MMR) gene defects.......Heredity is estimated to cause at least 20% of colorectal cancer. The hereditary nonpolyposis colorectal cancer subset is divided into Lynch syndrome and familial colorectal cancer type X (FCCTX) based on presence of mismatch repair (MMR) gene defects....

  5. Methylation Analysis of DNA Mismatch Repair Genes Using DNA Derived from the Peripheral Blood of Patients with Endometrial Cancer: Epimutation in Endometrial Carcinogenesis.

    Science.gov (United States)

    Takeda, Takashi; Banno, Kouji; Yanokura, Megumi; Adachi, Masataka; Iijima, Moito; Kunitomi, Haruko; Nakamura, Kanako; Iida, Miho; Nogami, Yuya; Umene, Kiyoko; Masuda, Kenta; Kobayashi, Yusuke; Yamagami, Wataru; Hirasawa, Akira; Tominaga, Eiichiro; Susumu, Nobuyuki; Aoki, Daisuke

    2016-10-14

    Germline mutation of DNA mismatch repair (MMR) genes is a cause of Lynch syndrome. Methylation of MutL homolog 1 (MLH1) and MutS homolog 2 (MSH2) has been detected in peripheral blood cells of patients with colorectal cancer. This methylation is referred to as epimutation. Methylation of these genes has not been studied in an unselected series of endometrial cancer cases. Therefore, we examined methylation of MLH1, MSH2, and MSH6 promoter regions of peripheral blood cells in 206 patients with endometrial cancer using a methylation-specific polymerase chain reaction (MSP). Germline mutation of MMR genes, microsatellite instability (MSI), and immunohistochemistry (IHC) were also analyzed in each case with epimutation. MLH1 epimutation was detected in a single patient out of a total of 206 (0.49%)-1 out of 58 (1.72%) with an onset age of less than 50 years. The patient with MLH1 epimutation showed high level MSI (MSI-H), loss of MLH1 expression and had developed endometrial cancer at 46 years old, complicated with colorectal cancer. No case had epimutation of MSH2 or MSH6. The MLH1 epimutation detected in a patient with endometrial cancer may be a cause of endometrial carcinogenesis. This result indicates that it is important to check epimutation in patients with endometrial cancer without a germline mutation of MMR genes.

  6. Improved generation of rat gene knockouts by target-selected mutagenesis in mismatch repair-deficient animals

    Directory of Open Access Journals (Sweden)

    van Roekel Henk S

    2008-10-01

    Full Text Available Abstract Background The laboratory rat (Rattus norvegicus is one of the preferred model organisms in physiological and pharmacological research, although the availability of specific genetic models, especially gene knockouts, is limited. N-ethyl-N-nitrosourea (ENU-driven target-selected mutagenesis is currently the most successful method in rats, although it is still very laborious and expensive. Results As ENU-induced DNA damage is normally recognized by the mismatch repair (MMR system, we hypothesized that the effectiveness of the target-selected mutagenesis approach could be improved by using a MMR-deficient genetic background. Indeed, Msh6 knockout rats were found to be more sensitive to ENU treatment and the germ line mutation rate was boosted more than two-fold to 1 mutation per 585 kb. In addition, the molecular mutation spectrum was found to be changed in favor of generating knockout-type alleles by ~20%, resulting in an overall increase in efficiency of ~2.5 fold. The improved effectiveness was demonstrated by high throughput mutation discovery in 70 Mb of sequence in a set of only 310 mutant F1 rats. This resulted in the identification of 89 mutations of which four introduced a premature stopcodon and 64 resulted in amino acid changes. Conclusion Taken together, we show that the use of a MMR-deficient background considerably improves ENU-driven target-selected mutagenesis in the rat, thereby reducing animal use as well as screening costs. The use of a mismatch repair-deficient genetic background for improving mutagenesis and target-selected knockout efficiency is in principle applicable to any organism of interest.

  7. Improved generation of rat gene knockouts by target-selected mutagenesis in mismatch repair-deficient animals

    Science.gov (United States)

    van Boxtel, Ruben; Toonen, Pim W; Verheul, Mark; van Roekel, Henk S; Nijman, Isaac J; Guryev, Victor; Cuppen, Edwin

    2008-01-01

    Background The laboratory rat (Rattus norvegicus) is one of the preferred model organisms in physiological and pharmacological research, although the availability of specific genetic models, especially gene knockouts, is limited. N-ethyl-N-nitrosourea (ENU)-driven target-selected mutagenesis is currently the most successful method in rats, although it is still very laborious and expensive. Results As ENU-induced DNA damage is normally recognized by the mismatch repair (MMR) system, we hypothesized that the effectiveness of the target-selected mutagenesis approach could be improved by using a MMR-deficient genetic background. Indeed, Msh6 knockout rats were found to be more sensitive to ENU treatment and the germ line mutation rate was boosted more than two-fold to 1 mutation per 585 kb. In addition, the molecular mutation spectrum was found to be changed in favor of generating knockout-type alleles by ~20%, resulting in an overall increase in efficiency of ~2.5 fold. The improved effectiveness was demonstrated by high throughput mutation discovery in 70 Mb of sequence in a set of only 310 mutant F1 rats. This resulted in the identification of 89 mutations of which four introduced a premature stopcodon and 64 resulted in amino acid changes. Conclusion Taken together, we show that the use of a MMR-deficient background considerably improves ENU-driven target-selected mutagenesis in the rat, thereby reducing animal use as well as screening costs. The use of a mismatch repair-deficient genetic background for improving mutagenesis and target-selected knockout efficiency is in principle applicable to any organism of interest. PMID:18840264

  8. Construction of heteroduplex DNA and in vitro model for functional analysis of mismatch repair

    Institute of Scientific and Technical Information of China (English)

    WANG Yi; Clark Alan; WANG Jiaxun; SUN Menghong; SHI Daren

    2004-01-01

    Functional deficiency of mismatch repair (MMR) system is one of the mechanisms of tumorigenesis. With the development of the investigation and the requirement from the clinical diagnosis and treatment it is necessary to build up a method to evaluate the functional status of the whole MMR system in the concerned tumors. The original ssDNA and dsDNA from wild type (wt) bacteriophage M13mp2 and its three derivates with mutation points in the lacZα Gene have been used to construct two kinds of heteroduplex DNA molecules. One named del(2) has two bases deleted in the negative strand, the other has a G·G mismatch base pair in the negative strand too. Introducing this heteroduplex DNA into E. Coli NR9162 (mutS-) without the MMR ability on the indicator plate with x-gal and IPTG, there are three kinds of plaques, mixture plaque as the characteristic phenotype of heteroduplex DNA, blue and clear plaques. If the cell extract is mismatch repair competent the percentage of the mixture plaque will decrease after incubation with these heteroduplex DNA, the repair efficiency is expressed in percentage as 100× (1 minus the ratio of percentages of mixture plaque obtained from the extract-treated sample and untreated samples), which can imply the functional status of MMR system of certain samples. After large T-antigen-dependent SV-40 DNA replication assay cell extract from TK6, a human lymphoblastoid B-cell lymphoma cell line with MMR ability, and Lovo, a human colonic carcinoma cell line with MMR deficiency have incubated with these heteroduplex DNA. The repair efficiency of TK6 to del(2) is more than 60%, to G·G is more than 50%. The Lovo efficiency to del(2) is less than 10%, to G·G is less than 20%. Therefore, in this in vitro model used for functional analysis of mismatch repair of heteroduplex DNA as the repair target, TK6 can serve as the control for MMR proficiency and Lovo as the control for MMR deficiency. Using this model the tumor tissue from a case of hereditary

  9. In vivo DNA mismatch repair measurement in zebrafish embryos and its use in screening of environmental carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yuanhong [Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035 (China); Huang, Changjiang, E-mail: cjhuang5711@163.com [Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035 (China); Bai, Chenglian; Du, Changchun; Liao, Junhua [Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035 (China); Dong, Qiaoxiang, E-mail: dqxdong@163.com [Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035 (China); School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou 325035 (China)

    2016-01-25

    Highlights: • We developed an in vivo DNA mismatch repair (MMR) measurement assay in zebrafish embryos. • This assay involves microinjection of homo- and heteroduplex EGFP plasmids into zebrafish embryos. • This novel assay was validated with embryos from the MMR-deficient mlh1 mutant fish. • We successfully applied this assay for detecting environmental chemicals with carcinogenic effect. • This novel assay can be used for screening of environmental carcinogens. - Abstract: Impairment of DNA mismatch repair (MMR) function leads to the development and progression of certain cancers. Many environmental contaminants can target DNA MMR system. Currently, measurement of MMR activity is limited to in vitro or in vivo methods at the cell line level, and reports on measurement of MMR activity at the live organism level are lacking. Here, we report an efficient method to measure DNA MMR activity in zebrafish embryos. A G-T mismatch was introduced into enhanced green fluorescent protein (EGFP) gene. Repair of the G-T mismatch to G-C in the heteroduplex plasmid generates a functional EGFP expression. The heteroduplex plasmid and a similarly constructed homoduplex plasmid were injected in parallel into the same batch of embryos at 1-cell stage and EGFP expression in EGFP positive embryos was quantified at 24 h after injection. MMR efficiency was calculated as the total fluorescence intensity of embryos injected with the heteroduplex construct divided by that of embryos injected with the homoduplex construct. Our results showed 73% reduction of MMR activity in embryos derived from MMR-deficient mlh1 mutant fish (positive control) when compared with embryos from MMR-competent wild type AB line fish, indicating feasibility of in vivo MMR activity measurement in zebrafish embryos. We further applied this novel assay for measurement of MMR efficiency in embryos exposed to environmental chemicals such as cadmium chloride (CdCl{sub 2}), benzo[a]pyrene (BaP), and

  10. MUTYH and the mismatch repair system: partners in crime?

    Science.gov (United States)

    Niessen, Renée C; Sijmons, Rolf H; Ou, J; Olthof, Sandra G M; Osinga, Jan; Ligtenberg, Marjolijn J; Hogervorst, Frans B L; Weiss, Marjan M; Tops, Carli M J; Hes, Frederik J; de Bock, Geertruida H; Buys, Charles H C M; Kleibeuker, Jan H; Hofstra, Robert M W

    2006-03-01

    Biallelic germline mutations of MUTYH-a gene encoding a base excision repair protein-are associated with an increased susceptibility of colorectal cancer. Whether monoallelic MUTYH mutations also increase cancer risk is not yet clear, although there is some evidence suggesting a slight increase of risk. As the MUTYH protein interacts with the mismatch repair (MMR) system, we hypothesised that the combination of a monoallelic MUTYH mutation with an MMR gene mutation increases cancer risk. We therefore investigated the prevalence of monoallelic MUTYH mutations in carriers of a germline MMR mutation: 40 carriers of a truncating mutation (group I) and 36 of a missense mutation (group II). These patients had been diagnosed with either colorectal or endometrial cancer. We compared their MUTYH mutation frequencies with those observed in a group of 134 Dutch colorectal and endometrial cancer patients without an MMR gene mutation (0.7%) and those reported for Caucasian controls (1.5%). In group I one monoallelic MUTYH mutation was found (2.5%). In group II five monoallelic germline MUTYH mutations were found (14%), four of them in MSH6 missense mutation carriers (20%). Of all patients with an MMR gene mutation, only those with a missense mutation showed a significantly higher frequency of (monoallelic) MUTYH mutations than the Dutch cancer patients without MMR gene mutations (P = 0.002) and the published controls (P = 0.001). These results warrant further study to test the hypothesis of mutations in MMR genes (in particular MSH6) and MUTYH acting together to increase cancer risk.

  11. Alkylation damage causes MMR-dependent chromosomal instability in vertebrate embryos.

    NARCIS (Netherlands)

    Feitsma, H.; Akay, A.; Cuppen, E.

    2008-01-01

    S(N)1-type alkylating agents, like N-methyl-N-nitrosourea (MNU) and N-ethyl-N-nitrosourea (ENU), are potent mutagens. Exposure to alkylating agents gives rise to O(6)-alkylguanine, a modified base that is recognized by DNA mismatch repair (MMR) proteins but is not repairable, resulting in

  12. Diagnostic criteria for constitutional mismatch repair deficiency syndrome

    DEFF Research Database (Denmark)

    Wimmer, Katharina; Kratz, Christian P; Vasen, Hans F A;

    2014-01-01

    Constitutional mismatch repair deficiency (CMMRD) syndrome is a distinct childhood cancer predisposition syndrome that results from biallelic germline mutations in one of the four MMR genes, MLH1, MSH2, MSH6 or PMS2. The tumour spectrum is very broad, including mainly haematological, brain...

  13. Influence of very short patch mismatch repair on SOS inducing lesions after aminoglycoside treatment in Escherichia coli.

    Science.gov (United States)

    Baharoglu, Zeynep; Mazel, Didier

    2014-01-01

    Low concentrations of aminoglycosides induce the SOS response in Vibrio cholerae but not in Escherichia coli. In order to determine whether a specific factor present in E. coli prevents this induction, we developed a genetic screen where only SOS inducing mutants are viable. We identified the vsr gene coding for the Vsr protein of the very short patch mismatch repair (VSPR) pathway. The effect of mismatch repair (MMR) mutants was also studied. We propose that lesions formed upon aminoglycoside treatment are preferentially repaired by VSPR without SOS induction in E. coli and by MMR when VSPR is impaired.

  14. Loss of DNA mismatch repair imparts a selective advantage in planarian adult stem cells.

    Directory of Open Access Journals (Sweden)

    Jessica P Hollenbach

    Full Text Available Lynch syndrome (LS leads to an increased risk of early-onset colorectal and other types of cancer and is caused by germline mutations in DNA mismatch repair (MMR genes. Loss of MMR function results in a mutator phenotype that likely underlies its role in tumorigenesis. However, loss of MMR also results in the elimination of a DNA damage-induced checkpoint/apoptosis activation barrier that may allow damaged cells to grow unchecked. A fundamental question is whether loss of MMR provides pre-cancerous stem cells an immediate selective advantage in addition to establishing a mutator phenotype. To test this hypothesis in an in vivo system, we utilized the planarian Schmidtea mediterranea which contains a significant population of identifiable adult stem cells. We identified a planarian homolog of human MSH2, a MMR gene which is mutated in 38% of LS cases. The planarian Smed-msh2 is expressed in stem cells and some progeny. We depleted Smed-msh2 mRNA levels by RNA-interference and found a striking survival advantage in these animals treated with a cytotoxic DNA alkylating agent compared to control animals. We demonstrated that this tolerance to DNA damage is due to the survival of mitotically active, MMR-deficient stem cells. Our results suggest that loss of MMR provides an in vivo survival advantage to the stem cell population in the presence of DNA damage that may have implications for tumorigenesis.

  15. Loss of DNA mismatch repair imparts a selective advantage in planarian adult stem cells.

    Science.gov (United States)

    Hollenbach, Jessica P; Resch, Alissa M; Palakodeti, Dasaradhi; Graveley, Brenton R; Heinen, Christopher D

    2011-01-01

    Lynch syndrome (LS) leads to an increased risk of early-onset colorectal and other types of cancer and is caused by germline mutations in DNA mismatch repair (MMR) genes. Loss of MMR function results in a mutator phenotype that likely underlies its role in tumorigenesis. However, loss of MMR also results in the elimination of a DNA damage-induced checkpoint/apoptosis activation barrier that may allow damaged cells to grow unchecked. A fundamental question is whether loss of MMR provides pre-cancerous stem cells an immediate selective advantage in addition to establishing a mutator phenotype. To test this hypothesis in an in vivo system, we utilized the planarian Schmidtea mediterranea which contains a significant population of identifiable adult stem cells. We identified a planarian homolog of human MSH2, a MMR gene which is mutated in 38% of LS cases. The planarian Smed-msh2 is expressed in stem cells and some progeny. We depleted Smed-msh2 mRNA levels by RNA-interference and found a striking survival advantage in these animals treated with a cytotoxic DNA alkylating agent compared to control animals. We demonstrated that this tolerance to DNA damage is due to the survival of mitotically active, MMR-deficient stem cells. Our results suggest that loss of MMR provides an in vivo survival advantage to the stem cell population in the presence of DNA damage that may have implications for tumorigenesis.

  16. Assessment of single nucleotide polymorphisms in screening 52 DNA repair and cell cycle control genes in Fanconi anemia patients

    Directory of Open Access Journals (Sweden)

    Petrović Sandra

    2015-01-01

    Full Text Available Fanconi anemia (FA is a rare genetically heterogeneous disorder associated with bone marrow failure, birth defects and cancer susceptibility. Apart from the disease- causing mutations in FANC genes, the identification of specific DNA variations, such as single nucleotide polymorphisms (SNPs, in other candidate genes may lead to a better clinical description of this condition enabling individualized treatment with improvement of the prognosis. In this study, we have assessed 95 SNPs located in 52 key genes involved in base excision repair (BER, nucleotide excision repair (NER, mismatch repair (MMR, double strand break (DSB repair and cell cycle control using a DNA repair chip (Asper Biotech, Estonia which includes most of the common variants for the candidate genes. The SNP genotyping was performed in five FA-D2 patients and in one FA-A patient. The polymorphisms studied were synonymous (n=10, nonsynonymous (missense (n=52 and in non-coding regions of the genome (introns and 5 ‘and 3’ untranslated regions (UTR (n=33. Polymorphisms found at the homozygous state are selected for further analysis. Our results have shown a significant inter-individual variability among patients in the type and the frequency of SNPs and also elucidate the need for further studies of polymorphisms located in ATM, APEX APE 1, XRCC1, ERCC2, MSH3, PARP4, NBS1, BARD1, CDKN1B, TP53 and TP53BP1 which may be of great importance for better clinical description of FA. In addition, the present report recommends the use of SNPs as predictive and prognostic genetic markers to individualize therapy of FA patients. [Projekat Ministarstva nauke Republike Srbije, br. 173046

  17. The news for MMR and clinical cancer%DNA错配修复和临床肿瘤新进展

    Institute of Scientific and Technical Information of China (English)

    马守成; 赵达

    2011-01-01

    DNA复制是一个严谨有序的过程,细胞分裂时,碱基错配的概率约为1/1010~1/109.错配修复系统(MMR)是一个从细菌到真核细胞皆保守的DNA修复途径,它负责修复DNA中错配的碱基,或者DNA聚合酶的校对功能失调而引起的复制错误,插入,遗失碱基,使DNA整体复制的保真度增加50~1000倍.MMR系统失控会导致DNA序列中微卫星序列的不稳定性(MSI)或编码功能蛋白的基因突变,改变正常细胞功能,从而引发肿瘤.%DNA replication is an extraordinarily faithful process, mutation occures at a frequency of 1/10 or 1/10 base pairs per cell division. The MMR pathway, a DNA repair pathway conserved from bacteria to humans, targets base substitution mismatches and insertion-deletion mismatches that arise as a result of replication errors that escape the proofreading function of DNA polymerases. In doing so, MMR contributes an additional 50 ~ 1000-fold to the o-verall fidelity of replication. Thus, inactivation of MMR confers a strong mutated phenotype in which the rate of spontaneous mutation is greatly elevated,such as microsatellite stability (MSI) , or mutated genes that code functional proteins, thus give rise to cancer.

  18. Epigenetic changes of DNA repair genes in cancer

    Institute of Scientific and Technical Information of China (English)

    Christoph Lahtz; Gerd P. Pfeifer

    2011-01-01

    'Every Hour Hurts, The Last One Kills'. That is an old saying about getting old. Every day, thousands of DNA damaging events take place in each cell of our body, but efficient DNA repair systems have evolved to prevent that. However, our DNA repair system and that of most other organisms are not as perfect as that of Deinococcus radiodurans, for example, which is able to repair massive amounts of DNA damage at one time. In many instances, accumulation of DNA damage has been linked to cancer, and genetic deficiencies in specific DNA repair genes are associated with tumor-prone phenotypes. In addition to mutations, which can be either inherited or somatically acquired, epigenetic silencing of DNA repair genes may promote tumorigenesis. This review will summarize current knowledge of the epigenetic inactivation of different DNA repair components in human cancer.

  19. Mismatch repair genes (hMLH1, hPMS1, hPMS2, GTBP/hMSH6, hMSH2) in the pathogenesis of hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Abdel-Rahman N. Zekri; Gelane M. Sabry; Abeer A. Bahnassy; Kamal A. Shalaby; Sabrin A. Abdel-Wahabh; Serag Zakaria

    2005-01-01

    AIM: DNA misrnatch repair (MMR) is an impotent mechanism for maintaining fidelity of genomic DNA. Abnormalities in one or more MMR genes are implicated in the development of many cancers. We investigated the role of expression of MMR genes (hMLH1, hPMS1, hPMS2, GTBP/hMSH6, hMSH2) in hepatocellular carcinogenesis. METHODS: We evaluated the expression level of MMR genes in 33 hepatocellular carcinoma (HCC) cases using the multiplex reverse transcription (RT) PCR assays, as well as in 16 cases of normal adjacent hepatic tissues. Β-actin gene was used as an internal control and calibrator for quantification of gene expression. RESULTS: Out of the 33 studied cases, 25 were HCV positiveand 30 (90.9%) showed reduced expression in one or more of the studied MMR genes. Reduced expression was found in hMSH2 (71.9%), hMLH1 (53.3%), GTBP (51.1%), hPMS2 (33.3%) and hPMS1 (6%). A significant correlation was found between reduced expression of hPMS2(P= 0.0069) and GTBP(P= 0.0034), hPMS2and non-cirrhosis (P= 0.0197),hMLH1 and high grade. On the other hand, 57.1%, 50%, 20%, 18.8%, and 6% of the normal tissues distant to tumors showed reduced expression of hMSH2, hMLH1, GTBP, hPMS2, and hPMS1 respectively. Multivariate analysis revealed a significant correlation between the expression level of hMSH2(P= 0.008), hMLH1 (P= 0.001) and GTBP (P = 0.032)and HCC, between hPMS2, GTBP and HCVassociated HCC (P<0.001, 0.002).CONCLUSION: Reduced expression of MMR genes seemsto play an important role in HCV-associated HCC. hPMS2 islikely involved at an early stage of hepatocarcinogenesis since it was detected in normal adjacent tissues. Reduced expression of hPMS2 provides a growth advantage and stimulates proliferation which encourages malignant transformation in non-cirrhotic HCV-infected patients via acquisition of more genetic damages.

  20. Impaired Cytogenetic Damage Repair and Cell Cycle Regulation in Response to Ionizing Radiation in Human Fibroblast Cells with Individual Knock-down of 25 Genes

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry; Emami, Kamal; Hammond, Dianne; Casey, Rachael; Mehta, Satish; Jeevarajan, Antony; Pierson, Duane; Wu, Honglu

    2008-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have demonstrated that genes with upregulated expression induced by IR may play important roles in DNA damage sensing, cell cycle checkpoint and chromosomal repair, the relationship between the regulation of gene expression by IR and its impact on cytogenetic responses to ionizing radiation has not been systematically studied. In our present study, the expression of 25 genes selected based on their transcriptional changes in response to IR or from their known DNA repair roles were individually knocked down by siRNA transfection in human fibroblast cells. Chromosome aberrations (CA) and micronuclei (MN) formation were measured as the cytogenetic endpoints. Our results showed that the yield of MN and/or CA formation were significantly increased by suppressed expression of 5 genes that included Ku70 in the DSB repair pathway; XPA in the NER pathway; RPA1 in the MMR pathway; RAD17 and RBBP8 in cell cycle control. Knocked-down expression of 4 genes including MRE11A, RAD51 in the DSB pathway, and SESN1 and SUMO1 showed significant inhibition of cell cycle progression, possibly because of severe impairment of DNA damage repair. Furthermore, loss of XPA, p21 and MLH1 expression resulted in both enhanced cell cycle progression and significantly higher yield of cytogenetic damage, indicating the involvement of these gene products in both cell cycle control and DNA damage repair. Of these 11 genes that affected the cytogenetic response, 9 were up-regulated in the cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulating the biological consequences after IR. Failure to express these IR-responsive genes, such as by gene mutation, could seriously change the outcome of the post IR scenario and lead to carcinogenesis.

  1. Preferential loss of mismatch repair function in refractory and relapsed acute myeloid leukemia: potential contribution to AML progression

    Institute of Scientific and Technical Information of China (English)

    Guogen Mao; Fenghua Yuan; Kimberly Absher; C Darrell Jennings; Dianna S Howard; Craig T Jordan; Liya Gu

    2008-01-01

    Acute myeloid leukemia (AML) is an aggressive hematological cancer. Despite therapeutic regimens that lead to complete remission, the vast majority of patients undergo relapse. The molecular mechanisms underlying AML development and relapse remain incompletely defined. To explore whether loss of DNA mismatch repair (MMR) function is involved in AML, we screened two key MMR genes, MSH2 and MLH1, for mutations and promoter hypermethylation in leukemia specimens from 53 AML patients and blood from 17 non-cancer controls. We show here that whereas no amino acid alteration or promoter hypermethylation was detected in all control samples, 18 AML patients exhibited either mutations in MMR genes or hypermethylation in the MLH1 promoter. In vitro functional MMR analysis revealed that almost all the mutations analyzed resulted in loss of MMR function. MMR defects were significantly more frequent in patients with refractory or relapsed AML compared with newly diagnosed patients. These observations suggest for the first time that the loss of MMR function is associated with refractory and relapsed AML and may contribute to disease pathogenesis.

  2. Completion of meiosis in male zebrafish (Danio rerio) despite lack of DNA mismatch repair gene mlh1

    NARCIS (Netherlands)

    Leal, M.C.; Feitsma, H.; Cuppen, E.; França, L.R.; Schulz, R.W.

    2008-01-01

    Mlh1 is a member of DNA mismatch repair (MMR) machinery and is also essential for the stabilization of crossovers during the first meiotic division. Recently, we have shown that zebrafish mlh1 mutant males are completely infertile because of a block in metaphase I, whereas females are fertile but ha

  3. Completion of meiosis in male zebrafish (Danio rerio) despite lack of DNA mismatch repair gene mlh1.

    NARCIS (Netherlands)

    Leal, M.C.; Feitsma, H.; Cuppen, E.; Franca, L.R.; Schulz, R.W.

    2008-01-01

    Mlh1 is a member of DNA mismatch repair (MMR) machinery and is also essential for the stabilization of crossovers during the first meiotic division. Recently, we have shown that zebrafish mlh1 mutant males are completely infertile because of a block in metaphase I, whereas females are fertile but

  4. Dynamic regulation of cerebral DNA repair genes by psychological stress

    DEFF Research Database (Denmark)

    Forsberg, Kristin; Aalling, Nadia; Wörtwein, Gitta

    2015-01-01

    for maintaining genomic integrity. The aim of the present study was to characterize the pattern of cerebral DNA repair enzyme regulation after stress through the quantification of a targeted range of gene products involved in different types of DNA repair. 72 male Sprague-Dawley rats were subjected to either...... was seen in HC, but with overall smaller effects and without the induction after acute stress. Nuclear DNA damage from oxidation as measured by the comet assay was unaffected by stress in both regions. We conclude that psychological stress have a dynamic influence on brain DNA repair gene expression...

  5. Evaluation of MMR Vaccination and Autism Link

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2002-11-01

    Full Text Available A retrospective cohort study of autism in all children born in Denmark from January 1991 through December 1998 and those receiving measles, mumps, and rubella (MMR vaccination is reported from the Danish Epidemiology Science Center, Aarhus, Denmark.

  6. Nuclear translocation contributes to regulation of DNA excision repair activities

    DEFF Research Database (Denmark)

    Knudsen, Nina Østergaard; Andersen, Sofie Dabros; Lützen, Anne;

    2009-01-01

    , it is evident that proteins from the different DNA repair pathways interact [Y. Wang, D. Cortez, P. Yazdi, N. Neff, S.J. Elledge, J. Qin, BASC, a super complex of BRCA1-associated proteins involved in the recognition and repair of aberrant DNA structures, Genes Dev. 14 (2000) 927-939; M. Christmann, M......DNA mutations are circumvented by dedicated specialized excision repair systems, such as the base excision repair (BER), nucleotide excision repair (NER), and mismatch repair (MMR) pathways. Although the individual repair pathways have distinct roles in suppressing changes in the nuclear DNA.......T. Tomicic, W.P. Roos, B. Kaina, Mechanisms of human DNA repair: an update, Toxicology 193 (2003) 3-34; N.B. Larsen, M. Rasmussen, L.J. Rasmussen, Nuclear and mitochondrial DNA repair: similar pathways? Mitochondrion 5 (2005) 89-108]. Protein interactions are not only important for function, but also...

  7. Control of gene editing by manipulation of DNA repair mechanisms.

    Science.gov (United States)

    Danner, Eric; Bashir, Sanum; Yumlu, Saniye; Wurst, Wolfgang; Wefers, Benedikt; Kühn, Ralf

    2017-04-03

    DNA double-strand breaks (DSBs) are produced intentionally by RNA-guided nucleases to achieve genome editing through DSB repair. These breaks are repaired by one of two main repair pathways, classic non-homologous end joining (c-NHEJ) and homology-directed repair (HDR), the latter being restricted to the S/G2 phases of the cell cycle and notably less frequent. Precise genome editing applications rely on HDR, with the abundant c-NHEJ formed mutations presenting a barrier to achieving high rates of precise sequence modifications. Here, we give an overview of HDR- and c-NHEJ-mediated DSB repair in gene editing and summarize the current efforts to promote HDR over c-NHEJ.

  8. Clinical features and mismatch repair gene mutation screening in Chinese patients with hereditary nonpolyposis colorectal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Shan-Run Liu; Bo Zhao; Zhen-Jun Wang; Yuan-Lian Wan; Yan-Ting Huang

    2004-01-01

    AIM: Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominantly- inherited cancer-susceptibility syndrome that confers an increased risk for colorectal cancer and a variety of other tumors at a young age. It has been associated with germline mutations in five mismatch repair (MMR) genes (hMSH2, hMLH1, hPMS1, hPMS2, and hMSH6/GTBP). The great majority of germline mutations were found in hMSH2 and hMLH1. The purpose of this study was to analyze the clinical features of Chinese HNPCC patients and to screen hMSH2 and hMLH1 gene mutations. METHODS: Twenty-eight independent Chinese families were collected, of which 15 met Amsterdam criteria I and 13 met the Japanese clinical diagnosis criteria. The data were recorded including sex, site of colorectal cancer (CRC),age of diagnosis, history of synchronous and/or metachronous CRC, instance of extracolonic cancers, and histopathology of tumors. Peripheral blood samples were collected from all pedigrees after formal written consents were signed. PCR and denaturing high-performance liquid chromatography (DHPLC) were used to screen the coding regions of hMSH2 and hMLH1 genes. The samples showing abnormal DHPLC profiles were sequenced by a 377 DNA sequencer.RESULTS: One hundred and seventy malignant neoplasms were found in one hundred and twenty-six patients (multiple cancer in twenty-three), including one hundred and twentyseven CRCs, fifteen gastric, seven endometrial, and five esophageal cancers. Seventy-seven point eight percent of the patients had CRCs, sharing the features of early occurrence (average age of onset, 45.9 years) and of the right-sided predominance reported in the literature. In Chinese HNPCC patients, gastric cancer occurred more frequently, accounting for 11.9% of all cancers patients and ranking second in the spectrum of HNPCC predisposing cancers. Synchronous CRCs occurred less frequently, only accounting for 3.1% of the total CRCs. Twenty percent of the colorectal patients had

  9. Pregnancy outcome following M.MR vaccination

    Directory of Open Access Journals (Sweden)

    nahid Lorzadeh

    2007-09-01

    Full Text Available Lorzadeh N1, Ghafarzadeh M1, Vahabi S2, Lashgar-ara GhR3 1. Assistant professor, Department of gynecology, Faculty of medicine, Lorestan University of medical sciences 2. Assistant profwssor, Department of anesthesiology, Faculty of medicine, Lorestan University of medical sciences 3. General practitioner, Information and drugs center of Lorestan health department Abstract Background: In this study we evaluate the outcome of pregnancy in the patient that received M. MR vaccine during M.MR vaccination program on Lorestan of fall 2003. Materials and methods: This is a descriptive epidemiologic study, we evaluated all of women that vaccinated with M.MR vaccine during pre and post conception. We collected and analyzed all of information like prognosis of pregnancy, congenital rubella syndrome, gestational age weigh of newborn. Results: In 92 pregnancy women infected with MMR vaccine, the prognosis of pregnancy clearly seen 88 pregnant women (96% 73 (83% had normal and healthy newborn infant and 5 (6% had spontaneot abortion and 10 pregnant women (11% had legal abortion. Mean gestational age at birth was 39.5 ± 2.1 and weigh of newborn was 3257 ± 535 grams. None of the live born infants had not congenital rubella syndrome. Conclusion: In this study we showed M.MR vaccination during pregnancy had not any complication pregnancy. But pregnancy yet is an contraindication for M.MR vaccibnation, vecause this patient theories have risk of congenital rubella syndrome.

  10. Suppressed expression of non-DSB repair genes inhibits gamma-radiation-induced cytogenetic repair and cell cycle arrest.

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry H; Emami, Kamal; Hammond, Dianne; Casey, Rachael; Mehta, Satish K; Jeevarajan, Antony S; Pierson, Duane L; Wu, Honglu

    2008-11-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in double-strand break (DSB) repair, and its impact on cytogenetic responses has not been well studied. The purpose of this study is to identify new roles of IR inducible genes in regulating DSB repair and cell cycle progression. In this study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by small interfering RNA in human fibroblast cells. Frequency of micronuclei (MN) formation and chromosome aberrations were measured to determine efficiency of cytogenetic repair, especially DSB repair. In response to IR, the formation of MN was significantly increased by suppressed expression of five genes: Ku70 (DSB repair pathway), XPA (nucleotide excision repair pathway), RPA1 (mismatch repair pathway), RAD17 and RBBP8 (cell cycle control). Knocked-down expression of four genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Moreover, decreased XPA, p21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Nine of these eleven genes, whose knock-down expression affected cytogenetic repair, were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate IR-induced biological consequences. Furthermore, eight non-DBS repair genes showed involvement in regulating DSB repair, indicating that

  11. Dual daughter strand incision is processive and increases the efficiency of DNA mismatch repair

    NARCIS (Netherlands)

    N. Hermans (Nicolaas); C. Laffeber; M. Cristovao (Michele); Artola-Borán, M. (Mariela); Mardenborough, Y. (Yannicka); P. Ikpa (Pauline); Jaddoe, A. (Aruna); H.H.K. Winterwerp (Herrie); C. Wyman (Claire); J. Jiricny (Josef); R. Kanaar (Roland); P. Friedhoff (Peter); J.H.G. Lebbink (Joyce)

    2016-01-01

    textabstractDNA mismatch repair (MMR) is an evolutionarily-conserved process responsible for the repair of replication errors. In Escherichia coli, MMR is initiated by MutS and MutL, which activate MutH to incise transiently-hemimethylated GATC sites. MMR efficiency depends on the distribution of th

  12. Genome Wide In silico Analysis of the Mismatch Repair Components of Plasmodium falciparum and Their Comparison with Human Host

    Science.gov (United States)

    Tarique, Mohammed; Ahmad, Moaz; Chauhan, Manish; Tuteja, Renu

    2017-01-01

    Malaria a major parasitic infection globally particularly in tropical and sub-tropical regions of the world is responsible for about 198 million cases and estimated deaths due to this disease are about 0.6 million. The emergence of drug resistance in the malaria parasite is alarming and it is necessary to understand its underlying cause and molecular mechanisms. It has been established that drug resistant malaria parasites have defective mismatch repair (MMR) therefore it is essential to study this pathway and its components in detail. Recently a number of non-synonymous Single Nucleotide Polymorphisms have been reported in genes involved in MMR pathways. PfMLH is an endonuclease essential to restore the MMR in drug resistant strains of Plasmodium falciparum. Considering all these facts about the role of MMR in emergence of drug resistant parasite, in this manuscript we report a genome wide analysis of the components of the MMR pathway such as MLH, Pms1, MSH2-1, MSH2-2, MSH6, and UvrD using in silico bioinformatics based approaches. The phylogenetic analysis revealed evolutionary closeness with the MMR components of various organisms. It is noteworthy that P. falciparum contains two homologs of MSH2, which are located on different chromosomes. The structural modeling of these components showed their similarity with the human/yeast MMR components. The docking studies reveal that PfUvrD and PfMLH interact with each other. The in silico identification of interacting partners of the major MMR components identified numerous P. falciparum specific proteins. In line with our previous studies the present study will also contribute significantly to understand the MMR pathway of malaria parasite. PMID:28232818

  13. Clinicopathologic factors identify sporadic mismatch repair-defective colon cancers

    DEFF Research Database (Denmark)

    Halvarsson, Britta; Anderson, Harald; Domanska, Katarina;

    2008-01-01

    Identification of sporadic mismatch repair (MMR)-defective colon cancers is increasingly demanded for decisions on adjuvant therapies. We evaluated clinicopathologic factors for the identification of these prognostically favorable tumors. Histopathologic features in 238 consecutive colon cancers...... and excluded 61.5% of the tumors from MMR testing. This clinicopathologic index thus successfully selects MMR-defective colon cancers. Udgivelsesdato: 2008-Feb...

  14. Targeted gene repair: the ups and downs of a promising gene therapy approach.

    Science.gov (United States)

    de Semir, David; Aran, Josep M

    2006-08-01

    As a novel form of molecular medicine based on direct actions over the genes, targeted gene repair has raised consideration recently above classical gene therapy strategies based on genetic augmentation or complementation. Targeted gene repair relies on the local induction of the cell's endogenous DNA repair mechanisms to attain a therapeutic gene conversion event within the genome of the diseased cell. Successful repair has been achieved both in vitro and in vivo with a variety of corrective molecules ranging from oligonucleotides (chimeraplasts, modified single-stranded oligonucleotides, triplex-forming oligonucleotides), to small DNA fragments (small fragment homologous replacement (SFHR)), and even viral vectors (AAV-based). However, controversy on the consistency and lack of reproducibility of early experiments regarding frequencies and persistence of targeted gene repair, particularly for chimeraplasty, has flecked the field. Nevertheless, several hurdles such as inefficient nuclear uptake of the corrective molecules, and misleading assessment of targeted repair frequencies have been identified and are being addressed. One of the key bottlenecks for exploiting the overall potential of the different targeted gene repair modalities is the lack of a detailed knowledge of their mechanisms of action at the molecular level. Several studies are now focusing on the assessment of the specific repair pathway(s) involved (homologous recombination, mismatch repair, etc.), devising additional strategies to increase their activity (using chemotherapeutic drugs, chimeric nucleases, etc.), and assessing the influence of the cell cycle in the regulation of the repair process. Until therapeutic correction frequencies for single gene disorders are reached both in cellular and animal models, precision and undesired side effects of this promising gene therapy approach will not be thoroughly evaluated.

  15. Influencing factors in MMR immunisation decision making.

    Science.gov (United States)

    Hill, Marie C; Cox, Carol L

    Immunisation decision making is not a straightforward process for parents. Many factors influence parental decision making on whether they immunise their child with the measles, mumps and rubella (MMR) vaccine. The feasibility study described in this article provides insight into influencing factors associated with decisions regarding the immunisation of children by parents. The study findings suggest that the practice nurse is a credible source of information for parents seeking informed decision making. At a time when the incidence of measles and mumps is rising in the UK, the provision of appropriate information by the practice nurse has the potential to increase uptake of the MMR vaccine.

  16. C-terminal fluorescent labeling impairs functionality of DNA mismatch repair proteins.

    Directory of Open Access Journals (Sweden)

    Angela Brieger

    Full Text Available The human DNA mismatch repair (MMR process is crucial to maintain the integrity of the genome and requires many different proteins which interact perfectly and coordinated. Germline mutations in MMR genes are responsible for the development of the hereditary form of colorectal cancer called Lynch syndrome. Various mutations mainly in two MMR proteins, MLH1 and MSH2, have been identified so far, whereas 55% are detected within MLH1, the essential component of the heterodimer MutLα (MLH1 and PMS2. Most of those MLH1 variants are pathogenic but the relevance of missense mutations often remains unclear. Many different recombinant systems are applied to filter out disease-associated proteins whereby fluorescent tagged proteins are frequently used. However, dye labeling might have deleterious effects on MutLα's functionality. Therefore, we analyzed the consequences of N- and C-terminal fluorescent labeling on expression level, cellular localization and MMR activity of MutLα. Besides significant influence of GFP- or Red-fusion on protein expression we detected incorrect shuttling of single expressed C-terminal GFP-tagged PMS2 into the nucleus and found that C-terminal dye labeling impaired MMR function of MutLα. In contrast, N-terminal tagged MutLαs retained correct functionality and can be recommended both for the analysis of cellular localization and MMR efficiency.

  17. Molecular cloning of the human excision repair gene ERCC-6.

    NARCIS (Netherlands)

    C. Troelstra (Christine); H. Odijk (Hanny); J. de Wit (Jan); A. Westerveld (Andries); L.H. Thompson; D. Bootsma (Dirk); J.H.J. Hoeijmakers (Jan)

    1990-01-01

    textabstractThe UV-sensitive, nucleotide excision repair-deficient Chinese hamster mutant cell line UV61 was used to identify and clone a correcting human gene, ERCC-6. UV61, belonging to rodent complementation group 6, is only moderately UV sensitive in comparison with mutant lines in groups 1 to 5

  18. Dominant mutations in S. cerevisiae PMS1 identify the Mlh1-Pms1 endonuclease active site and an exonuclease 1-independent mismatch repair pathway.

    Directory of Open Access Journals (Sweden)

    Catherine E Smith

    2013-10-01

    Full Text Available Lynch syndrome (hereditary nonpolypsis colorectal cancer or HNPCC is a common cancer predisposition syndrome. Predisposition to cancer in this syndrome results from increased accumulation of mutations due to defective mismatch repair (MMR caused by a mutation in one of the mismatch repair genes MLH1, MSH2, MSH6 or PMS2/scPMS1. To better understand the function of Mlh1-Pms1 in MMR, we used Saccharomyces cerevisiae to identify six pms1 mutations (pms1-G683E, pms1-C817R, pms1-C848S, pms1-H850R, pms1-H703A and pms1-E707A that were weakly dominant in wild-type cells, which surprisingly caused a strong MMR defect when present on low copy plasmids in an exo1Δ mutant. Molecular modeling showed these mutations caused amino acid substitutions in the metal coordination pocket of the Pms1 endonuclease active site and biochemical studies showed that they inactivated the endonuclease activity. This model of Mlh1-Pms1 suggested that the Mlh1-FERC motif contributes to the endonuclease active site. Consistent with this, the mlh1-E767stp mutation caused both MMR and endonuclease defects similar to those caused by the dominant pms1 mutations whereas mutations affecting the predicted metal coordinating residue Mlh1-C769 had no effect. These studies establish that the Mlh1-Pms1 endonuclease is required for MMR in a previously uncharacterized Exo1-independent MMR pathway.

  19. Common variants associated with general and MMR vaccine-related febrile seizures

    Science.gov (United States)

    Feenstra, Bjarke; Pasternak, Björn; Geller, Frank; Carstensen, Lisbeth; Wang, Tongfei; Huang, Fen; Eitson, Jennifer L.; Hollegaard, Mads V.; Svanström, Henrik; Vestergaard, Mogens; Hougaard, David M.; Schoggins, John W.; Jan, Lily Yeh; Melbye, Mads; Hviid, Anders

    2014-01-01

    Febrile seizures represent a recognized serious adverse event following measles, mumps, and rubella (MMR) vaccination. We conducted a series of genome-wide association scans comparing children with MMR-related febrile seizures, children with febrile seizures unrelated to vaccination, and controls with no history of febrile seizures. Two loci were distinctly associated with MMR-related febrile seizures, harboring the interferon-stimulated gene IFI44L (rs273259; P = 5.9×10−12 vs. controls; P =1.2×10−9 vs. MMR-unrelated febrile seizures) and the measles virus receptor CD46 (rs1318653; P = 9.6×10−11 vs. controls; P = 1.6×10−9 vs. MMR-unrelated febrile seizures). Furthermore, four loci were associated with febrile seizures in general implicating the sodium channel genes SCN1A (rs6432860; P = 2.2×10−16) and SCN2A (rs3769955; P = 3.1×10−10), a TMEM16 family gene (TMEM16C; rs114444506; P = 3.7×10−20), and a region associated with magnesium levels (12q21.33; rs11105468; P = 3.4×10−11). Finally, functional relevance of TMEM16C was demonstrated with electrophysiological experiments in wild-type and knockout rats. PMID:25344690

  20. Mismatch repair genes Mlh1 and Mlh3 modify CAG instability in Huntington's disease mice: genome-wide and candidate approaches.

    Directory of Open Access Journals (Sweden)

    Ricardo Mouro Pinto

    2013-10-01

    Full Text Available The Huntington's disease gene (HTT CAG repeat mutation undergoes somatic expansion that correlates with pathogenesis. Modifiers of somatic expansion may therefore provide routes for therapies targeting the underlying mutation, an approach that is likely applicable to other trinucleotide repeat diseases. Huntington's disease Hdh(Q111 mice exhibit higher levels of somatic HTT CAG expansion on a C57BL/6 genetic background (B6.Hdh(Q111 than on a 129 background (129.Hdh(Q111 . Linkage mapping in (B6x129.Hdh(Q111 F2 intercross animals identified a single quantitative trait locus underlying the strain-specific difference in expansion in the striatum, implicating mismatch repair (MMR gene Mlh1 as the most likely candidate modifier. Crossing B6.Hdh(Q111 mice onto an Mlh1 null background demonstrated that Mlh1 is essential for somatic CAG expansions and that it is an enhancer of nuclear huntingtin accumulation in striatal neurons. Hdh(Q111 somatic expansion was also abolished in mice deficient in the Mlh3 gene, implicating MutLγ (MLH1-MLH3 complex as a key driver of somatic expansion. Strikingly, Mlh1 and Mlh3 genes encoding MMR effector proteins were as critical to somatic expansion as Msh2 and Msh3 genes encoding DNA mismatch recognition complex MutSβ (MSH2-MSH3. The Mlh1 locus is highly polymorphic between B6 and 129 strains. While we were unable to detect any difference in base-base mismatch or short slipped-repeat repair activity between B6 and 129 MLH1 variants, repair efficiency was MLH1 dose-dependent. MLH1 mRNA and protein levels were significantly decreased in 129 mice compared to B6 mice, consistent with a dose-sensitive MLH1-dependent DNA repair mechanism underlying the somatic expansion difference between these strains. Together, these data identify Mlh1 and Mlh3 as novel critical genetic modifiers of HTT CAG instability, point to Mlh1 genetic variation as the likely source of the instability difference in B6 and 129 strains and suggest

  1. Mismatch repair genes Mlh1 and Mlh3 modify CAG instability in Huntington's disease mice: genome-wide and candidate approaches.

    Science.gov (United States)

    Pinto, Ricardo Mouro; Dragileva, Ella; Kirby, Andrew; Lloret, Alejandro; Lopez, Edith; St Claire, Jason; Panigrahi, Gagan B; Hou, Caixia; Holloway, Kim; Gillis, Tammy; Guide, Jolene R; Cohen, Paula E; Li, Guo-Min; Pearson, Christopher E; Daly, Mark J; Wheeler, Vanessa C

    2013-10-01

    The Huntington's disease gene (HTT) CAG repeat mutation undergoes somatic expansion that correlates with pathogenesis. Modifiers of somatic expansion may therefore provide routes for therapies targeting the underlying mutation, an approach that is likely applicable to other trinucleotide repeat diseases. Huntington's disease Hdh(Q111) mice exhibit higher levels of somatic HTT CAG expansion on a C57BL/6 genetic background (B6.Hdh(Q111) ) than on a 129 background (129.Hdh(Q111) ). Linkage mapping in (B6x129).Hdh(Q111) F2 intercross animals identified a single quantitative trait locus underlying the strain-specific difference in expansion in the striatum, implicating mismatch repair (MMR) gene Mlh1 as the most likely candidate modifier. Crossing B6.Hdh(Q111) mice onto an Mlh1 null background demonstrated that Mlh1 is essential for somatic CAG expansions and that it is an enhancer of nuclear huntingtin accumulation in striatal neurons. Hdh(Q111) somatic expansion was also abolished in mice deficient in the Mlh3 gene, implicating MutLγ (MLH1-MLH3) complex as a key driver of somatic expansion. Strikingly, Mlh1 and Mlh3 genes encoding MMR effector proteins were as critical to somatic expansion as Msh2 and Msh3 genes encoding DNA mismatch recognition complex MutSβ (MSH2-MSH3). The Mlh1 locus is highly polymorphic between B6 and 129 strains. While we were unable to detect any difference in base-base mismatch or short slipped-repeat repair activity between B6 and 129 MLH1 variants, repair efficiency was MLH1 dose-dependent. MLH1 mRNA and protein levels were significantly decreased in 129 mice compared to B6 mice, consistent with a dose-sensitive MLH1-dependent DNA repair mechanism underlying the somatic expansion difference between these strains. Together, these data identify Mlh1 and Mlh3 as novel critical genetic modifiers of HTT CAG instability, point to Mlh1 genetic variation as the likely source of the instability difference in B6 and 129 strains and suggest that MLH1

  2. Mismatch repair protein expression and colorectal cancer in Hispanics from Puerto Rico.

    Science.gov (United States)

    De Jesus-Monge, Wilfredo E; Gonzalez-Keelan, Carmen; Zhao, Ronghua; Hamilton, Stanley R; Rodriguez-Bigas, Miguel; Cruz-Correa, Marcia

    2010-06-01

    Colorectal cancer (CRC) is a leading cause of morbidity and mortality and alterations in mismatch repair (MMR) genes, leading to absent protein (negative) expression, are responsible for approximately 20% of CRC cases. Immunohistochemistry is a tool for prescreening of MMR protein expression in CRC but the literature on its use on Hispanics is scarce. However, Hispanics represent the second leading ethnicity in the United States (US) and CRC is a public health burden in this group. Our objectives were to determine the frequency of MMR protein-negative CRC and to evaluate its association with clinical and pathological characteristics among Hispanics from Puerto Rico, for the first time to our knowledge. A retrospective observational study of unselected CRC patients from the Puerto Rico Medical Center from 2001 to 2005 was done. MLH1 and MSH2, the most commonly altered MMR genes, protein expression was evaluated using immunohistochemistry, with microsatellite instability (MSI) and BRAF gene analyses in the absence of MLH1 protein expression. One-hundred sixty-four CRC patients were evaluated: the overall MMR protein-negative frequency was 4.3%, with 0.6% frequency of co-occurrence of MLH1-protein negative expression, MSI-high, and normal BRAF gene. MMR protein-negative expression was associated with proximal colon location (P = 0.02) and poor histological tumor differentiation (P = 0.001), but not with other characteristics. The frequency of MMR protein-negative CRC in Hispanics from Puerto Rico was lower than reported in other populations. This finding may explain the lower CRC incidence rate among US Hispanics as compared to US non-Hispanic whites and blacks.

  3. DNA repair and gene therapy: implications for translational uses.

    Science.gov (United States)

    Limp-Foster, M; Kelley, M R

    2000-01-01

    Gene therapy has been proposed to have implications in the treatment of cancer. By genetically manipulating the hematopoietic stem cell compartment with genes that confer resistance to chemotherapeutic agents, the dose escalation that is necessary to effectively treat the cancers could potentially be achieved. DNA repair genes are some of the potential candidates to confer increased resistance to chemotherapeutic agents. Although initial focus in this area has been on the direct reversal protein (MGMT), its protective ability is limited to those agents that produce O(6)-methylGuanine cross-links-agents that are not extensively used clinically (e.g., nitrosoureas). Furthermore, most alkylating agents attack more sites in DNA other than O(6)-methylGuanine, such that the protections afforded by MGMT may prevent the initial cytotoxicity, but at a price of increased mutational burden and potential secondary leukemias. Therefore, some of the genes that are being tested as candidates for gene transfer are base excision repair (BER) genes. We and others have found that overexpression of selective BER genes confers resistance to chemotherapeutic agents such as thiotepa, ionizing radiation, bleomycin, and other agents. As these "proof of concept" analyses mature, many more clinically relevant chemotherapeutic agents can be tested for BER protective ability.

  4. Mammalian mismatch repair

    DEFF Research Database (Denmark)

    Pena Diaz, Javier; Jiricny, Josef

    2012-01-01

    A considerable surge of interest in the mismatch repair (MMR) system has been brought about by the discovery of a link between Lynch syndrome, an inherited predisposition to cancer of the colon and other organs, and malfunction of this key DNA metabolic pathway. This review focuses on recent...... advances in our understanding of the molecular mechanisms of canonical MMR, which improves replication fidelity by removing misincorporated nucleotides from the nascent DNA strand. We also discuss the involvement of MMR proteins in two other processes: trinucleotide repeat expansion and antibody maturation...

  5. Gene therapy and peripheral nerve repair: a perspective

    Directory of Open Access Journals (Sweden)

    Stefan A. Hoyng

    2015-07-01

    Full Text Available Clinical phase I/II studies have demonstrated the safety of gene therapy for a variety of central nervous system disorders, including Canavan’s, Parkinson’s and Alzheimer’s disease, retinal diseases and pain. The majority of gene therapy studies in the CNS have used adeno-associated viral vectors (AAV and the first AAV-based therapeutic, a vector encoding lipoprotein lipase, is now marketed in Europe under the name Glybera. These remarkable advances may become relevant to translational research on gene therapy to promote peripheral nervous system (PNS repair. This short review first summarizes the results of gene therapy in animal models for peripheral nerve repair. Secondly, we identify key areas of future research in the domain of PNS-gene therapy. Finally, a perspective is provided on the path to clinical translation of PNS gene therapy for traumatic nerve injuries. In the latter section we discuss the route and mode of delivery of the vector to human patients, the efficacy and safety of the vector, and the choice of the patient population for a first possible proof-of-concept clinical study.

  6. Induction of a mutant phenotype in human repair proficient cells after overexpression of a mutated human DNA repair gene.

    NARCIS (Netherlands)

    P.B.G.M. Belt; M.F. van Oostenrijk; H. Odijk (Hanny); J.H.J. Hoeijmakers (Jan); C.M.P. Backendorf (Claude)

    1991-01-01

    textabstractAntisense and mutated cDNA of the human excision repair gene ERCC-1 were overexpressed in repair efficient HeLa cells by means of an Epstein-Barr-virus derived CDNA expression vector. Whereas antisense RNA did not influence the survival of the transfected cells, a mutated cDNA generating

  7. Sister chromatid gene conversion is a prominent double-strand break repair pathway in mammalian cells

    OpenAIRE

    Johnson, Roger D.; Jasin, Maria

    2000-01-01

    In mammalian cells, repair of DNA double-strand breaks (DSBs) occurs by both homologous and non-homologous mechanisms. By definition, homologous recombination requires a template with sufficient sequence identity to the damaged molecule in order to direct repair. We now show that the sister chromatid acts as a repair template in a substantial proportion of DSB repair events. The outcome of sister chromatid repair is primarily gene conversion unassociated with reciprocal exchange. This contras...

  8. Regulation of the Saccharomyces cerevisiae DNA repair gene RAD16.

    Science.gov (United States)

    Bang, D D; Timmermans, V; Verhage, R; Zeeman, A M; van de Putte, P; Brouwer, J

    1995-05-25

    The RAD16 gene product has been shown to be essential for the repair of the silenced mating type loci [Bang et al. (1992) Nucleic Acids Res. 20, 3925-3931]. More recently we demonstrated that the RAD16 and RAD7 proteins are also required for repair of non-transcribed strands of active genes in Saccharomyces cerevisiae [Waters et al. (1993) Mol. Gen. Genet. 239, 28-32]. We have studied the regulation of the RAD16 gene and found that the RAD16 transcript levels increased up to 7-fold upon UV irradiation. Heat shock at 42 degrees C also results in elevated levels of RAD16 mRNA. In sporulating MAT alpha/MATa diploid cells RAD16 mRNA is also induced. The basal level of the RAD16 transcript is constant during the mitotic cell cycle. G1-arrested cells show normal induction of RAD16 mRNA upon UV irradiation demonstrating that the induction is not a secondary consequence of G2 cell cycle arrest following UV irradiation. However, in cells arrested in G1 the induction of RAD16 mRNA after UV irradiation is not followed by a rapid decline as occurs in normal growing cells suggesting that the down regulation of RAD16 transcription is dependent on progression into the cell cycle.

  9. Double-strand break damage and associated DNA repair genes predispose smokers to gene methylation

    OpenAIRE

    Leng, Shuguang; Stidley, Christine A.; Willink, Randy; Bernauer, Amanda; Do, Kieu; Picchi, Maria A.; Sheng, Xin; Frasco, Melissa, A.; Berg, David Van Den; Gilliland, Frank D.; Zima, Christopher; Crowell, Richard E.; Belinsky, Steven A.

    2008-01-01

    Gene promoter hypermethylation in sputum is a promising biomarker for predicting lung cancer. Identifying factors that predispose smokers to methylation of multiple gene promoters in the lung could impact strategies for early detection and chemoprevention. This study evaluated the hypothesis that double-strand break repair capacity and sequence variation in genes in this pathway are associated with a high methylation index in a cohort of current and former cancer-free smokers. A 50% reduction...

  10. Simulated microgravity influenced the expression of DNA damage repair genes

    Science.gov (United States)

    Zhang, Meng; Sun, Yeqing; Jiawei, Liu; Wang, Ting

    2016-07-01

    Ionizing radiation and microgravity were considered to be the most important stress factors of space environmental the respective study of the biological effects of the radiation and microgravity carried out earlier, but the interaction of the effects of radiation with microgravity started later, and due to difference of the materials and methods the result of this experiment were not consistent. To further investigate the influence of microgravity on the expression of the radiation damage repair genes, the seed of Arabidopsis (Col) and its gravity-insensitive mutant (PIN2) were exposed to 0.1Gy of the dose of energetic carbon-ion beam radiation (LET = 30KeV / μm), and the germinated seed were than fixed in the 3D random positioning apparatus immediately for a 10-day simulated microgravity. By measuring the deflection angle of root tip and the changes of the expression of Ku70 and RAD51 protein, we investigated the impact of microgravity effect on radiation damage repair systems. The results shown that radiation, microgravity and microgravity with radiation could increase the angle of the root of the Col significantly, but no obvious effect on PIN2 type. The radiation could increase the expression of Ku70 significantly in both Col and PIN2, microgravity does not affect the expression, but the microgravity with radiation could decrease the expression of Ku70. This result shown that the microgravity could influence the radiation damage repair systems in molecular level. Moreover, our findings were important to understand the molecular mechanism of the impact of microgravity effect on radiation damage repair systems in vivo.

  11. Polymorphism of the DNA Base Excision Repair Genes in Keratoconus

    Directory of Open Access Journals (Sweden)

    Katarzyna A. Wojcik

    2014-10-01

    Full Text Available Keratoconus (KC is a degenerative corneal disorder for which the exact pathogenesis is not yet known. Oxidative stress is reported to be associated with this disease. The stress may damage corneal biomolecules, including DNA, and such damage is primarily removed by base excision repair (BER. Variation in genes encoding BER components may influence the effectiveness of corneal cells to cope with oxidative stress. In the present work we genotyped 5 polymorphisms of 4 BER genes in 284 patients and 353 controls. The A/A genotype of the c.–1370T>A polymorphism of the DNA polymerase γ (POLG gene was associated with increased occurrence of KC, while the A/T genotype was associated with decreased occurrence of KC. The A/G genotype and the A allele of the c.1196A>G polymorphism of the X-ray repair cross-complementing group 1 (XRCC1 were associated with increased, and the G/G genotype and the G allele, with decreased KC occurrence. Also, the C/T and T as well as C/C genotypes and alleles of the c.580C>T polymorphism of the same gene displayed relationship with KC occurrence. Neither the g.46438521G>C polymorphism of the Nei endonuclease VIII-like 1 (NEIL1 nor the c.2285T>C polymorphism of the poly(ADP-ribose polymerase-1 (PARP-1 was associated with KC. In conclusion, the variability of the XRCC1 and POLG genes may play a role in KC pathogenesis and determine the risk of this disease.

  12. A cost-effectiveness analysis of colorectal screening of hereditary nonpolyposis colorectal carcinoma gene carriers

    NARCIS (Netherlands)

    Vasen, HFA; van Ballegooijen, M; Buskens, E; Kleibeuker, JK; Taal, BG; Griffioen, G; Nagengast, FM; Menko, FH; Khan, PM

    1998-01-01

    BACKGROUND. It has been estimated that the prevalence of carriers of a mutated mismatch repair (MMR) gene among the general population in Western countries is between 5 and 50 per 10,000. These carriers have a risk of >85% of developing colorectal carcinoma (CRC) and therefore need careful

  13. Gene variants of unknown clinical significance in Lynch syndrome. An introduction for clinicians

    NARCIS (Netherlands)

    Sijmons, Rolf H.; Greenblatt, Marc S.; Genuardi, Maurizio

    2013-01-01

    Clinicians referring patients for genetic testing for Lynch syndrome will sooner or later receive results for DNA Mismatch Repair (MMR) genes reporting DNA changes that are unclear from a clinical point of view. These changes are referred to as variants of unknown, or unclear, clinical significance

  14. First report of a de novo germline mutation in the MLH1 gene

    NARCIS (Netherlands)

    Stulp, Rein P; Vos, Yvonne J; Mol, Bart; Karrenbeld, Arend; de Raad, Monique; van der Mijle, Huub J C; Sijmons, Rolf H

    2006-01-01

    Hereditary non-polyposis colorectal carcinoma (HNPCC) is an autosomal dominant disorder associated with colorectal and endometrial cancer and a range of other tumor types. Germline mutations in the DNA mismatch repair (MMR) genes, particularly MLH1, MSH2, and MSH6, underlie this disorder. The vast m

  15. A cost-effectiveness analysis of colorectal screening of hereditary nonpolyposis colorectal carcinoma gene carriers

    NARCIS (Netherlands)

    Vasen, HFA; van Ballegooijen, M; Buskens, E; Kleibeuker, JK; Taal, BG; Griffioen, G; Nagengast, FM; Menko, FH; Khan, PM

    1998-01-01

    BACKGROUND. It has been estimated that the prevalence of carriers of a mutated mismatch repair (MMR) gene among the general population in Western countries is between 5 and 50 per 10,000. These carriers have a risk of >85% of developing colorectal carcinoma (CRC) and therefore need careful follow-up

  16. Evolution and mutagenesis of the mammalian excision repair gene ERCC-1

    NARCIS (Netherlands)

    M. van Duin (Mark); J. van den Tol; P. Warmerdam (Peter); H. Odijk (Hanny); D.N. Meijer (Dies); A. Westerveld (Andries); D. Bootsma (Dirk); J.H.J. Hoeijmakers (Jan)

    1988-01-01

    textabstractThe human DNA excision repair protein ERCC-1 exhibits homology to the yeast RADIO repair protein and its longer C-terminus displays similarity to parts of the E.coli repair proteins uvrA and uvrC. To study the evolution of this 'mosaic' ERCC-1 gene we have isolated the mouse homologue.

  17. Distinct Clinicopathological Patterns of Mismatch Repair Status in Colorectal Cancer Stratified by KRAS Mutations.

    Directory of Open Access Journals (Sweden)

    Wenbin Li

    Full Text Available In sporadic colorectal cancer (CRC, the BRAFV600E mutation is associated with deficient mismatch repair (MMR status and inversely associated with to KRAS mutations. In contrast to deficient MMR (dMMR CRC, data on the presence of KRAS oncogenic mutations in proficient MMR (pMMR CRC and their relationship with tumor progression are scarce. We therefore examined the MMR status in combination with KRAS mutations in 913 Chinese patients and correlated the findings obtained with clinical and pathological features. The MMR status was determined based on detection of MLH1, MSH2, MSH6 and PMS2 expression. KRAS mutation and dMMR status were detected in 36.9% and 7.5% of cases, respectively. Four subtypes were determined by MMR and KRAS mutation status: KRAS (+/pMMR (34.0%, KRAS (+/dMMR (2.9%, KRAS (-/pMMR (58.5% and KRAS (-/dMMR (4.6%. A higher percentage of pMMR tumors with KRAS mutation were most likely to be female (49.0%, proximal located (45.5%, a mucinous histology (38.4%, and to have increased lymph node metastasis (60.3%, compared with pMMR tumors without BRAFV600E and KRAS mutations (36.0%, 29.3%, 29.4% and 50.7%, respectively; all P < 0.01. To the contrary, compared with those with KRAS(-/dMMR tumors, patients with KRAS(+/dMMR tumors demonstrated no statistically significant differences in gender, tumor location, pT depth of invasion, lymph node metastasis, pTNM stage, and histologic grade. This study revealed that specific epidemiologic and clinicopathologic characteristics are associated with MMR status stratified by KRAS mutation. Knowledge of MMR and KRAS mutation status may enhance molecular pathologic staging of CRC patients and metastatic progression in CRC can be estimated based on the combination of these biomarkers.

  18. Mechanisms and functions of DNA mismatch repair

    Institute of Scientific and Technical Information of China (English)

    Guo MinLi

    2008-01-01

    DNA mismatch repair (MMR) is a highly conserved biological pathway that plays a key role in maintaining genomic stability. The specificity of MMR is primarily for base-base mismatches and insertion/deletion mispairs generated dur-ing DNA replication and recombination. MMR also suppresses homeologous recombination and was recently shown to play a role in DNA damage signaling in eukaryotic cells. Escherichia coli MutS and MutL and their eukaryotic homo-logs, MutSα and MutLα, respectively, are key players in MMR-associated genome maintenance. Many other protein components that participate in various DNA metabolic pathways, such as PCNA and RPA, are also essential for MMR. Defects in MMR are associated with genome-wide instability, predisposition to certain types of cancer including he-reditary non-polyposis colorectal cancer, resistance to certain chemotherapeutic agents, and abnormalities in meiosis and sterility in mammalian systems.

  19. Changes in DNA repair during aging

    Science.gov (United States)

    Gorbunova, Vera; Seluanov, Andrei; Mao, Zhiyong; Hine, Christpher

    2007-01-01

    DNA is a precious molecule. It encodes vital information about cellular content and function. There are only two copies of each chromosome in the cell, and once the sequence is lost no replacement is possible. The irreplaceable nature of the DNA sets it apart from other cellular molecules, and makes it a critical target for age-related deterioration. To prevent DNA damage cells have evolved elaborate DNA repair machinery. Paradoxically, DNA repair can itself be subject to age-related changes and deterioration. In this review we will discuss the changes in efficiency of mismatch repair (MMR), base excision repair (BER), nucleotide excision repair (NER) and double-strand break (DSB) repair systems during aging, and potential changes in DSB repair pathway usage that occur with age. Mutations in DNA repair genes and premature aging phenotypes they cause have been reviewed extensively elsewhere, therefore the focus of this review is on the comparison of DNA repair mechanisms in young versus old. PMID:17913742

  20. Unintended events following immunization with MMR: a systematic review.

    Science.gov (United States)

    Jefferson, Tom; Price, Deirdre; Demicheli, Vittorio; Bianco, Elvira

    2003-09-08

    Public debate over the safety of the trivalent measles, mumps and rubella (MMR) vaccine and the drop in vaccination rates in several countries persists despite its almost universal use and accepted effectiveness. We carried out a systematic review to assess the evidence of unintended effects (beneficial or harmful) associated with MMR and the applicability of systematic reviewing methods to the field of safety evaluation. Eligible studies were comparative prospective or retrospective on healthy individuals up to 15 years of age, carried out or published by 2003. We identified 120 articles satisfying our inclusion criteria and included 22. MMR is associated with a lower incidence of upper respiratory tract infections, a higher incidence of irritability, similar incidence of other adverse effects compared to placebo and is likely to be associated with benign thrombocytopenic purpura (TP), parotitis, joint and limb complaints and aseptic meningitis (mumps Urabe strain-containing MMR). Exposure to MMR is unlikely to be associated with Crohn's disease, ulcerative colitis, autism or aseptic meningitis (mumps Jeryl-Lynn strain-containing MMR). The design and reporting of safety outcomes in MMR vaccine studies, both pre- and post-marketing, are largely inadequate. The evidence of adverse events following immunization with MMR cannot be separated from its role in preventing the target diseases.

  1. MMR vaccination of children with egg allergy is safe

    DEFF Research Database (Denmark)

    Andersen, Dorthe Vestergård; Jørgensen, Inger Merete

    2013-01-01

    Measles, mumps and rubella (MMR) vaccination is part of the Danish Childhood Vaccination Programme. It is known that children may react with anaphylaxis to MMR vaccines containing traces of egg protein. In Denmark, national clinical guidelines recommend that children with egg allergy be referred...

  2. A mononucleotide repeat in PRRT2 is an important, frequent target of mismatch repair deficiency in cancer

    NARCIS (Netherlands)

    I. Teles Alves (Inês); Cano, D. (David); R. Böttcher (René); H.A.G.M. van der Korput (Hetty); W.N.M. Dinjens (Winand); G.W. Jenster (Guido); J. Trapman (Hans)

    2017-01-01

    textabstractThe DNA mismatch repair (MMR) system corrects DNA replication mismatches thereby contributing to the maintenance of genomic stability. MMR deficiency has been observed in prostate cancer but its impact on the genomic landscape of these tumours is not known. In order to identify MMR assoc

  3. Interaction of DNA repair gene polymorphisms and aflatoxin B1 in the risk of hepatocellular carcinoma

    OpenAIRE

    2014-01-01

    Aflatoxin B1 (AFB1) is an important environmental carcinogen and can induce DNA damage and involve in the carcinogenesis of hepatocellular carcinoma (HCC). The deficiency of DNA repair capacity related to the polymorphisms of DNA repair genes might play a central role in the process of HCC tumorigenesis. However, the interaction of DNA repair gene polymorphisms and AFB1 in the risk of hepatocellular carcinoma has not been elucidated. In this study, we investigated whether six polymorphisms (i...

  4. Whole Gene Capture Analysis of 15 CRC Susceptibility Genes in Suspected Lynch Syndrome Patients.

    Directory of Open Access Journals (Sweden)

    Anne M L Jansen

    Full Text Available Lynch Syndrome (LS is caused by pathogenic germline variants in one of the mismatch repair (MMR genes. However, up to 60% of MMR-deficient colorectal cancer cases are categorized as suspected Lynch Syndrome (sLS because no pathogenic MMR germline variant can be identified, which leads to difficulties in clinical management. We therefore analyzed the genomic regions of 15 CRC susceptibility genes in leukocyte DNA of 34 unrelated sLS patients and 11 patients with MLH1 hypermethylated tumors with a clear family history.Using targeted next-generation sequencing, we analyzed the entire non-repetitive genomic sequence, including intronic and regulatory sequences, of 15 CRC susceptibility genes. In addition, tumor DNA from 28 sLS patients was analyzed for somatic MMR variants.Of 1979 germline variants found in the leukocyte DNA of 34 sLS patients, one was a pathogenic variant (MLH1 c.1667+1delG. Leukocyte DNA of 11 patients with MLH1 hypermethylated tumors was negative for pathogenic germline variants in the tested CRC susceptibility genes and for germline MLH1 hypermethylation. Somatic DNA analysis of 28 sLS tumors identified eight (29% cases with two pathogenic somatic variants, one with a VUS predicted to pathogenic and LOH, and nine cases (32% with one pathogenic somatic variant (n = 8 or one VUS predicted to be pathogenic (n = 1.This is the first study in sLS patients to include the entire genomic sequence of CRC susceptibility genes. An underlying somatic or germline MMR gene defect was identified in ten of 34 sLS patients (29%. In the remaining sLS patients, the underlying genetic defect explaining the MMRdeficiency in their tumors might be found outside the genomic regions harboring the MMR and other known CRC susceptibility genes.

  5. Molecular characterization of the human excision repair gene ERCC-1: cDNA cloning and aminoacid homology with the yeast DNA repair gene RAD10.

    NARCIS (Netherlands)

    M. van Duin (Mark); J. de Wit (Jan); H. Odijk (Hanny); A. Westerveld (Andries); A. Yasui (Akira); M.H.M. Koken (Marcel); J.H.J. Hoeijmakers (Jan); D. Bootsma (Dirk)

    1986-01-01

    textabstractThe human excision repair gene ERCC-7 was cloned after DNA mediated gene transfer to the CHO mutant 43-38, which is sensitive to ultraviolet light and mitomycin-C. We describe the cloning and sequence analysis of the ERCC-7 cDNA and partial characterization of the gene. ERCC.1 has a size

  6. Analysis of DNA repair gene polymorphisms and survival in low-grade and anaplastic gliomas

    DEFF Research Database (Denmark)

    Berntsson, Shala Ghaderi; Wibom, Carl; Sjöström, Sara;

    2011-01-01

    The purpose of this study was to explore the variation in DNA repair genes in adults with WHO grade II and III gliomas and their relationship to patient survival. We analysed a total of 1,458 tagging single-nucleotide polymorphisms (SNPs) that were selected to cover DNA repair genes, in 81 grade ...

  7. Detection of coding microsatellite frameshift mutations in DNA mismatch repair-deficient mouse intestinal tumors.

    Science.gov (United States)

    Woerner, Stefan M; Tosti, Elena; Yuan, Yan P; Kloor, Matthias; Bork, Peer; Edelmann, Winfried; Gebert, Johannes

    2015-11-01

    Different DNA mismatch repair (MMR)-deficient mouse strains have been developed as models for the inherited cancer predisposing Lynch syndrome. It is completely unresolved, whether coding mononucleotide repeat (cMNR) gene mutations in these mice can contribute to intestinal tumorigenesis and whether MMR-deficient mice are a suitable molecular model of human microsatellite instability (MSI)-associated intestinal tumorigenesis. A proof-of-principle study was performed to identify mouse cMNR-harboring genes affected by insertion/deletion mutations in MSI murine intestinal tumors. Bioinformatic algorithms were developed to establish a database of mouse cMNR-harboring genes. A panel of five mouse noncoding mononucleotide markers was used for MSI classification of intestinal matched normal/tumor tissues from MMR-deficient (Mlh1(-/-) , Msh2(-/-) , Msh2(LoxP/LoxP) ) mice. cMNR frameshift mutations of candidate genes were determined by DNA fragment analysis. Murine MSI intestinal tumors but not normal tissues from MMR-deficient mice showed cMNR frameshift mutations in six candidate genes (Elavl3, Tmem107, Glis2, Sdccag1, Senp6, Rfc3). cMNRs of mouse Rfc3 and Elavl3 are conserved in type and length in their human orthologs that are known to be mutated in human MSI colorectal, endometrial and gastric cancer. We provide evidence for the utility of a mononucleotide marker panel for detection of MSI in murine tumors, the existence of cMNR instability in MSI murine tumors, the utility of mouse subspecies DNA for identification of polymorphic repeats, and repeat conservation among some orthologous human/mouse genes, two of them showing instability in human and mouse MSI intestinal tumors. MMR-deficient mice hence are a useful molecular model system for analyzing MSI intestinal carcinogenesis.

  8. Truncation of the MSH2 C-terminal 60 amino acids disrupts effective DNA mismatch repair and is causative for Lynch syndrome.

    Science.gov (United States)

    Wielders, Eva; Delzenne-Goette, Elly; Dekker, Rob; van der Valk, Martin; Te Riele, Hein

    2017-04-01

    Missense variants of DNA mismatch repair (MMR) genes pose a problem in clinical genetics as long as they cannot unambiguously be assigned as the cause of Lynch syndrome (LS). To study such variants of uncertain clinical significance, we have developed a functional assay based on direct measurement of MMR activity in mouse embryonic stem cells expressing mutant protein from the endogenous alleles. We have applied this protocol to a specific truncation mutant of MSH2 that removes 60 C-terminal amino acids and has been found in suspected LS families. We show that the stability of the MSH2/MSH6 heterodimer is severely perturbed, causing attenuated MMR in in vitro assays and cancer predisposition in mice. This mutation can therefore unambiguously be considered as deleterious and causative for LS.

  9. RRAF-V600E is not involved in the colorectal tumorigenesis of HNPCC in patients with functional MLH1 and MSH2 genes

    NARCIS (Netherlands)

    Domingo, E; Niessen, RC; Oliveira, C; Alhopuro, P; Moutinho, C; Espin, E; Armengol, M; Sijmons, RH; Kleibeuker, JH; Seruca, R; Aaltonen, LA; Imai, K; Yamamoto, H; Schwartz, S; Hofstra, RMW

    2005-01-01

    Recently, it was shown that the oncogenic activation of BRAF, a member of the RAS/RAF family of kinases, by the V600E mutation is characteristic for sporadic colon tumors with microsatellite instability. Further, it was shown to associate with the silencing of the mismatch repair (MMR) gene MLH1 by

  10. DNA mismatch repair deficiency in sporadic colorectal cancer and Lynch Syndrome

    OpenAIRE

    Poulogiannis, George; Frayling, Ian; Arends, Mark

    2009-01-01

    Abstract DNA mismatch repair (MMR) deficiency is one of the best understood forms of genetic instability in colorectal cancer (CRC), and is characterised by the loss of function of the MMR pathway. Failure to repair replication-associated errors due to a defective MMR system allows persistence of mismatch mutations all over the genome, but especially in regions of repetitive DNA known as microsatellites, giving rise to the phenomenon of microsatellite instability (MSI). A high freq...

  11. MMR vaccination of children with egg allergy is safe

    DEFF Research Database (Denmark)

    Andersen, Dorthe Vestergård; Jørgensen, Inger Merete

    2013-01-01

    Measles, mumps and rubella (MMR) vaccination is part of the Danish Childhood Vaccination Programme. It is known that children may react with anaphylaxis to MMR vaccines containing traces of egg protein. In Denmark, national clinical guidelines recommend that children with egg allergy be referred...... to vaccination at a paediatric ward despite changed recommendations in other countries. The purpose of this study was to determine whether children with egg allergy presented with anaphylactic/allergic reactions to MMR vaccination and to discuss whether Danish recommendations should be upheld....

  12. MMR vaccination of children with egg allergy is safe

    DEFF Research Database (Denmark)

    Andersen, Dorthe Vestergård; Jørgensen, Inger Merete

    2013-01-01

    Measles, mumps and rubella (MMR) vaccination is part of the Danish Childhood Vaccination Programme. It is known that children may react with anaphylaxis to MMR vaccines containing traces of egg protein. In Denmark, national clinical guidelines recommend that children with egg allergy be referred...... to vaccination at a paediatric ward despite changed recommendations in other countries. The purpose of this study was to determine whether children with egg allergy presented with anaphylactic/allergic reactions to MMR vaccination and to discuss whether Danish recommendations should be upheld....

  13. Transfection of the cloned human excision repair gene ERCC-1 to UV-sensitive CHO mutants only corrects the repair defect in complementation group 2 mutants.

    NARCIS (Netherlands)

    M. van Duin (Mark); J.H. Janssen; J. de Wit (Jan); J.H.J. Hoeijmakers (Jan); L.H. Thompson; D. Bootsma (Dirk); A. Westerveld (Andries)

    1988-01-01

    textabstractThe human DNA-excision repair gene ERCC-1 is cloned by its ability to correct the excision-repair defect of the ultraviolet light- and mitomycin-C-sensitive CHO mutant cell line 43-3B. This mutant is assigned to complementation group 2 of the excision-repair-deficient CHO mutants. In ord

  14. DREMECELS: A Curated Database for Base Excision and Mismatch Repair Mechanisms Associated Human Malignancies.

    Directory of Open Access Journals (Sweden)

    Ankita Shukla

    Full Text Available DNA repair mechanisms act as a warrior combating various damaging processes that ensue critical malignancies. DREMECELS was designed considering the malignancies with frequent alterations in DNA repair pathways, that is, colorectal and endometrial cancers, associated with Lynch syndrome (also known as HNPCC. Since lynch syndrome carries high risk (~40-60% for both cancers, therefore we decided to cover all three diseases in this portal. Although a large population is presently affected by these malignancies, many resources are available for various cancer types but no database archives information on the genes specifically for only these cancers and disorders. The database contains 156 genes and two repair mechanisms, base excision repair (BER and mismatch repair (MMR. Other parameters include some of the regulatory processes that have roles in these disease progressions due to incompetent repair mechanisms, specifically BER and MMR. However, our unique database mainly provides qualitative and quantitative information on these cancer types along with methylation, drug sensitivity, miRNAs, copy number variation (CNV and somatic mutations data. This database would serve the scientific community by providing integrated information on these disease types, thus sustaining diagnostic and therapeutic processes. This repository would serve as an excellent accompaniment for researchers and biomedical professionals and facilitate in understanding such critical diseases. DREMECELS is publicly available at http://www.bioinfoindia.org/dremecels.

  15. Triple Negative Breast Cancers Have a Reduced Expression of DNA Repair Genes

    Science.gov (United States)

    Andreis, Daniele; Bertoni, Ramona; Giardini, Roberto; Fox, Stephen B.; Broggini, Massimo; Bottini, Alberto; Zanoni, Vanessa; Bazzola, Letizia; Foroni, Chiara; Generali, Daniele; Damia, Giovanna

    2013-01-01

    DNA repair is a key determinant in the cellular response to therapy and tumor repair status could play an important role in tailoring patient therapy. Our goal was to evaluate the mRNA of 13 genes involved in different DNA repair pathways (base excision, nucleotide excision, homologous recombination, and Fanconi anemia) in paraffin embedded samples of triple negative breast cancer (TNBC) compared to luminal A breast cancer (LABC). Most of the genes involved in nucleotide excision repair and Fanconi Anemia pathways, and CHK1 gene were significantly less expressed in TNBC than in LABC. PARP1 levels were higher in TNBC than in LABC. In univariate analysis high level of FANCA correlated with an increased overall survival and event free survival in TNBC; however multivariate analyses using Cox regression did not confirm FANCA as independent prognostic factor. These data support the evidence that TNBCs compared to LABCs harbour DNA repair defects. PMID:23825533

  16. Polymorphisms of the DNA repair genes XRCC1 and XRCC3 in a Brazilian population

    Directory of Open Access Journals (Sweden)

    Duarte Márcia Cristina

    2005-01-01

    Full Text Available In several DNA repair genes, polymorphisms may result in reduced repair capacity, which has been implicated as a risk factor for various types of cancer. The frequency of the polymorphic alleles varies among populations, suggesting an ethnic distribution of genotypes. We genotyped 300 healthy Southeastern Brazilian individuals (262 of European ancestry and 38 of African ancestry for polymorphisms of codons 194 and 399 of the XRCC1 base excision repair pathway gene and of codon 241 of the XRCC3 homologous recombination repair pathway gene. The allele frequencies were 0.07 for the Arg194Trp and 0.33 for the Arg399Gln codons of the XRCC1 gene and 0.35 for the Thr241Met codon of the XRCC3 gene. The genotypic frequencies were within Hardy-Weinberg equilibrium. These frequencies showed ethnic variability when compared with those obtained for different populations from several countries.

  17. DNA repair in human cells: from genetic complementation to isolation of genes.

    NARCIS (Netherlands)

    D. Bootsma (Dirk); A. Westerveld (Andries); J.H.J. Hoeijmakers (Jan)

    1988-01-01

    textabstractThe genetic disease xeroderma pigmentosum (XP) demonstrates the association between defective repair of DNA lesions and cancer. Complementation analysis performed on XP cell strains and on repair deficient rodent cell lines has revealed that at least nine and possibly more than 13 genes

  18. Cloning and characterization of the human DNA-excision repair gene ERCC-1

    NARCIS (Netherlands)

    M. van Duin (Michel)

    1988-01-01

    textabstractIt is the aim of the work described in this thesis to isolate and characterize human genes involved DNA excision repair. This will facilitate the understanding of the mechanism of this repair process whereas it also provides an important step to better understand the relationship

  19. Cloning and characterization of the human DNA-excision repair gene ERCC-1

    NARCIS (Netherlands)

    M. van Duin (Michel)

    1988-01-01

    textabstractIt is the aim of the work described in this thesis to isolate and characterize human genes involved DNA excision repair. This will facilitate the understanding of the mechanism of this repair process whereas it also provides an important step to better understand the relationship between

  20. DNA repair in human cells: from genetic complementation to isolation of genes.

    NARCIS (Netherlands)

    D. Bootsma (Dirk); A. Westerveld (Andries); J.H.J. Hoeijmakers (Jan)

    1988-01-01

    textabstractThe genetic disease xeroderma pigmentosum (XP) demonstrates the association between defective repair of DNA lesions and cancer. Complementation analysis performed on XP cell strains and on repair deficient rodent cell lines has revealed that at least nine and possibly more than 13 genes

  1. SELECTIVE-INHIBITION OF REPAIR OF ACTIVE GENES BY HYPERTHERMIA IS DUE TO INHIBITION OF GLOBAL AND TRANSCRIPTION COUPLED REPAIR PATHWAYS

    NARCIS (Netherlands)

    SAKKERS, RJ; FILON, AR; BRUNSTING, JF; KAMPINGA, HH; KONINGS, AWT; MULLENDERS, LHF

    1995-01-01

    Hyperthermia specifically inhibits the repair of UV-induced DNA photolesions in transcriptionally active genes, To define more precisely which mechanisms underlie the heat-induced inhibition of repair of active genes, removal of cyclobutane pyrimidine dimers (CPDs) was studied in human fibroblasts w

  2. DNA Mismatch Repair System: Repercussions in Cellular Homeostasis and Relationship with Aging

    Directory of Open Access Journals (Sweden)

    Juan Cristóbal Conde-Pérezprina

    2012-01-01

    Full Text Available The mechanisms that concern DNA repair have been studied in the last years due to their consequences in cellular homeostasis. The diverse and damaging stimuli that affect DNA integrity, such as changes in the genetic sequence and modifications in gene expression, can disrupt the steady state of the cell and have serious repercussions to pathways that regulate apoptosis, senescence, and cancer. These altered pathways not only modify cellular and organism longevity, but quality of life (“health-span”. The DNA mismatch repair system (MMR is highly conserved between species; its role is paramount in the preservation of DNA integrity, placing it as a necessary focal point in the study of pathways that prolong lifespan, aging, and disease. Here, we review different insights concerning the malfunction or absence of the DNA-MMR and its impact on cellular homeostasis. In particular, we will focus on DNA-MMR mechanisms regulated by known repair proteins MSH2, MSH6, PMS2, and MHL1, among others.

  3. DNA Mismatch Repair System: Repercussions in Cellular Homeostasis and Relationship with Aging

    Science.gov (United States)

    Conde-Pérezprina, Juan Cristóbal; León-Galván, Miguel Ángel; Konigsberg, Mina

    2012-01-01

    The mechanisms that concern DNA repair have been studied in the last years due to their consequences in cellular homeostasis. The diverse and damaging stimuli that affect DNA integrity, such as changes in the genetic sequence and modifications in gene expression, can disrupt the steady state of the cell and have serious repercussions to pathways that regulate apoptosis, senescence, and cancer. These altered pathways not only modify cellular and organism longevity, but quality of life (“health-span”). The DNA mismatch repair system (MMR) is highly conserved between species; its role is paramount in the preservation of DNA integrity, placing it as a necessary focal point in the study of pathways that prolong lifespan, aging, and disease. Here, we review different insights concerning the malfunction or absence of the DNA-MMR and its impact on cellular homeostasis. In particular, we will focus on DNA-MMR mechanisms regulated by known repair proteins MSH2, MSH6, PMS2, and MHL1, among others. PMID:23213348

  4. Differential expression of tissue repair genes in the pathogenesis of chronic obstructive pulmonary disease

    National Research Council Canada - National Science Library

    Gosselink, John V; Hayashi, Shizu; Elliott, W Mark; Xing, Li; Chan, Becky; Yang, Luojia; Wright, Claire; Sin, Don; Paré, Peter D; Pierce, John A; Pierce, Richard A; Patterson, Alex; Cooper, Joel; Hogg, James C

    2010-01-01

    .... The expression of 54 genes associated with repair of repetitively damaged tissue was measured in 136 paired samples of small bronchioles and surrounding lung tissue separated by laser capture microdissection...

  5. Production of truncated MBD4 protein by frameshift mutation in DNA mismatch repair-deficient cells enhances 5-fluorouracil sensitivity that is independent of hMLH1 status.

    Science.gov (United States)

    Suzuki, Satoshi; Iwaizumi, Moriya; Tseng-Rogenski, Stephanie; Hamaya, Yasushi; Miyajima, Hiroaki; Kanaoka, Shigeru; Sugimoto, Ken; Carethers, John M

    2016-07-02

    Methyl-CpG binding domain protein 4 (MBD4) is a DNA glycosylase that can remove 5-fluorodeoxyuracil from DNA as well as repair T:G or U:G mismatches. MBD4 is a target for frameshift mutation with DNA mismatch repair (MMR) deficiency, creating a truncated MBD4 protein (TruMBD4) that lacks its glycosylase domain. Here we show that TruMBD4 plays an important role for enhancing 5-fluorouracil (5FU) sensitivity in MMR-deficient colorectal cancer cells. We found biochemically that TruMBD4 binds to 5FU incorporated into DNA with higher affinity than MBD4. TruMBD4 reduced the 5FU affinity of the MMR recognition complexes that determined 5FU sensitivity by previous reports, suggesting other mechanisms might be operative to trigger cytotoxicity. To analyze overall 5FU sensitivity with TruMBD4, we established TruMBD4 overexpression in hMLH1-proficient or -deficient colorectal cancer cells followed by treatment with 5FU. 5FU-treated TruMBD4 cells demonstrated diminished growth characteristics compared to controls, independently of hMLH1 status. Flow cytometry revealed more 5FU-treated TruMBD4 cells in S phase than controls. We conclude that patients with MMR-deficient cancers, which show characteristic resistance to 5FU therapy, may be increased for 5FU sensitivity via secondary frameshift mutation of the base excision repair gene MBD4.

  6. Efficient and reproducible identification of mismatch repair deficient colon cancer

    DEFF Research Database (Denmark)

    Joost, Patrick; Bendahl, Pär-Ola; Halvarsson, Britta;

    2013-01-01

    BACKGROUND: The identification of mismatch-repair (MMR) defective colon cancer is clinically relevant for diagnostic, prognostic and potentially also for treatment predictive purposes. Preselection of tumors for MMR analysis can be obtained with predictive models, which need to demonstrate ease...... of application and favorable reproducibility. METHODS: We validated the MMR index for the identification of prognostically favorable MMR deficient colon cancers and compared performance to 5 other prediction models. In total, 474 colon cancers diagnosed ≥ age 50 were evaluated with correlation between...... and efficiently identifies MMR defective colon cancers with high sensitivity and specificity. The model shows stable performance with low inter-observer variability and favorable performance when compared to other MMR predictive models....

  7. Genomic survey and expression analysis of DNA repair genes in the genus Leptospira.

    Science.gov (United States)

    Martins-Pinheiro, Marinalva; Schons-Fonseca, Luciane; da Silva, Josefa B; Domingos, Renan H; Momo, Leonardo Hiroyuki Santos; Simões, Ana Carolina Quirino; Ho, Paulo Lee; da Costa, Renata M A

    2016-04-01

    Leptospirosis is an emerging zoonosis with important economic and public health consequences and is caused by pathogenic leptospires. The genus Leptospira belongs to the order Spirochaetales and comprises saprophytic (L. biflexa), pathogenic (L. interrogans) and host-dependent (L. borgpetersenii) members. Here, we present an in silico search for DNA repair pathways in Leptospira spp. The relevance of such DNA repair pathways was assessed through the identification of mRNA levels of some genes during infection in animal model and after exposition to spleen cells. The search was performed by comparison of available Leptospira spp. genomes in public databases with known DNA repair-related genes. Leptospires exhibit some distinct and unexpected characteristics, for instance the existence of a redundant mechanism for repairing a chemically diverse spectrum of alkylated nucleobases, a new mutS-like gene and a new shorter version of uvrD. Leptospira spp. shares some characteristics from Gram-positive, as the presence of PcrA, two RecQ paralogs and two SSB proteins; the latter is considered a feature shared by naturally competent bacteria. We did not find a significant reduction in the number of DNA repair-related genes in both pathogenic and host-dependent species. Pathogenic leptospires were enriched for genes dedicated to base excision repair and non-homologous end joining. Their evolutionary history reveals a remarkable importance of lateral gene transfer events for the evolution of the genus. Up-regulation of specific DNA repair genes, including components of SOS regulon, during infection in animal model validates the critical role of DNA repair mechanisms for the complex interplay between host/pathogen.

  8. [Characteristics and Outcomes of Treatment in Patients with Stage IV Colorectal Cancer with Mismatch Repair Deficiency].

    Science.gov (United States)

    Ishibashi, Keiichiro; Chika, Noriyasu; Suzuki, Okihide; Ito, Tetsuya; Amano, Kunihiko; Kumamoto, Kensuke; Fukuchi, Minoru; Kumagai, Youichi; Mochiki, Erito; Ishida, Hideyuki

    2016-11-01

    Mismatch repair(MMR)protein deficiency in colorectal cancer is well correlated with high-level microsatellite instability (MSI-H). There are little data on mismatch repair deficiency(dMMR)colorectal cancers in Japan. In addition, we have no available data on the therapeutic efficacy of oxaliplatin(oxa)-based chemotherapy, one of the standard treatment regimens for metastatic colorectal cancer, for patients with dMMR colorectal cancer. The subjects were 254 patients with Stage IV colorectal cancer whose tumors were immunohistochemically stained for MMR proteins, MLH1, MSH2, MSH6, and PMS2. Patients who underwent R0 resection were excluded. Clinicopathologic factors and the efficacy of oxa-based chemotherapy were compared between patients with dMMR colorectal cancer and those with mismatch repair proficient(pMMR)colorectal cancer. There were 7(2.8%)patients with dMMR. Four patients demonstrated both MLH1 and PMS2 loss, while 3 patients demonstrated both MSH2 and MSH6 loss. Though the dMMR had a higher frequency in female patients(p=0.02) and a lower frequency in those with liver metastasis(pcolorectal cancers was lower than those(4-11%)reported in Western countries. Therefore, the clinical significance of universal screeningfor dMMR in all colorectal cancer samples may not be valid. Concerningsurvival benefit, oxa-based chemotherapy seems to be an effective alternative in clinical practice for metastatic colorectal cancer patients with dMMR.

  9. Transcript RNA supports precise repair of its own DNA gene.

    Science.gov (United States)

    Keskin, Havva; Meers, Chance; Storici, Francesca

    2016-01-01

    The transfer of genetic information from RNA to DNA is considered an extraordinary process in molecular biology. Despite the fact that cells transcribe abundant amount of RNA with a wide range of functions, it has been difficult to uncover whether RNA can serve as a template for DNA repair and recombination. An increasing number of experimental evidences suggest a direct role of RNA in DNA modification. Recently, we demonstrated that endogenous transcript RNA can serve as a template to repair a DNA double-strand break (DSB), the most harmful DNA lesion, not only indirectly via formation of a DNA copy (cDNA) intermediate, but also directly in a homology driven mechanism in budding yeast. These results point out that the transfer of genetic information from RNA to DNA is more general than previously thought. We found that transcript RNA is more efficient in repairing a DSB in its own DNA (in cis) than in a homologous but ectopic locus (in trans). Here, we summarize current knowledge about the process of RNA-driven DNA repair and recombination, and provide further data in support of our model of DSB repair by transcript RNA in cis. We show that a DSB is precisely repaired predominately by transcript RNA and not by residual cDNA in conditions in which formation of cDNA by reverse transcription is inhibited. Additionally, we demonstrate that defects in ribonuclease (RNase) H stimulate precise DSB repair by homologous RNA or cDNA sequence, and not by homologous DNA sequence carried on a plasmid. These results highlight an antagonistic role of RNase H in RNA-DNA recombination. Ultimately, we discuss several questions that should be addressed to better understand mechanisms and implications of RNA-templated DNA repair and recombination.

  10. DNA repair gene polymorphisms in relation to chromosome aberration frequencies in retired radiation workers

    Energy Technology Data Exchange (ETDEWEB)

    Wilding, Craig S. [Genetics Department, Westlakes Research Institute, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3JY (United Kingdom)]. E-mail: craig.wilding@westlakes.ac.uk; Relton, Caroline L. [Genetics Department, Westlakes Research Institute, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3JY (United Kingdom); Paediatric and Lifecourse Epidemiology Research Group, School of Clinical Medical Sciences (Child Health), Newcastle University, Sir James Spence Institute, Royal Victoria Infirmary, Newcastle-upon-Tyne NE1 4LP (United Kingdom); Rees, Gwen S. [Genetics Department, Westlakes Research Institute, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3JY (United Kingdom); Tarone, Robert E. [International Epidemiology Institute, 1455 Research Boulevard, Suite 550, Rockville, MD 20850 (United States); Whitehouse, Caroline A. [Genetics Department, Westlakes Research Institute, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3JY (United Kingdom); Tawn, E. Janet [Genetics Department, Westlakes Research Institute, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3JY (United Kingdom)

    2005-02-15

    Polymorphic variation in DNA repair genes was examined in a group of retired workers from the British Nuclear Fuels plc facility at Sellafield in relation to previously determined translocation frequencies in peripheral blood lymphocytes. Variation at seven polymorphisms in four genes involved in the base excision repair (XRCC1 R194W, R399Q and a [AC]{sub n} microsatellite in the 3' UTR) and double strand break repair (XRCC3 T241M and a [AC]{sub n} microsatellite in intron 3 of XRCC3, XRCC4 I134T, and a GACTAn microsatellite located 120kb 5' of XRCC5) pathways was determined for 291 retired radiation workers who had received cumulative occupational external radiation doses of between 0 and 1873mSv. When the interaction between radiation dose and each DNA repair gene polymorphism was examined in relation to translocation frequency there was no evidence for any of the polymorphisms studied influencing the response to occupational exposure. A positive interaction observed between genotype (individuals with at least one allele >=20 repeat units) at a microsatellite locus in the XRCC3 gene and smoking status should be interpreted cautiously because interactions were investigated for seven polymorphisms and two exposures. Nonetheless, further research is warranted to examine whether this DNA repair gene variant might be associated with a sub-optimal repair response to smoking-induced DNA damage and hence an increased frequency of translocations.

  11. Chromosomal Aberrations and DNA Repair Gene Variants in a Radon-exposed Population

    Energy Technology Data Exchange (ETDEWEB)

    Kiuru, A.; Lindholm, C.; Koivistoinen, A.; Salomaa, S.

    2004-07-01

    Polymorphisms of XRCC1 (X-ray repair cross-complementing group 1), XRCC3 (X-ray repair cross-complementing group 3), and hOGG1 (the human homologue of the yeast OGG1 gene) DNA repair genes have been associated with altered DNA repair capacity and risk of various cancers. In the present study our goal was to clarify the influence of various DNA repair gene variants on the frequency of chromosomal aberrations (CA) in subjects exposed to residential radon. The study group of 84 non-smoking, healthy individuals exposed to domestic radon were analysed using the fluorescence in-situ hybridization (FISH) technique. No association between radon concentration and CA frequencies was observed. However, a significant increase with age was shown as well as a large variability in translocation frequencies between individuals within the same age group. In order to investigate the role of individual susceptibility to this variation genotypes of DNA repair genes XRCC1 (codons 194, 280 and 399), XRCC3 (codon 241) and hOGG1 (codon 326) were determined from leukocyte DNA using methods based on polymerase chain reaction. Multiple regression analysis was applied to evaluate the effect of the polymorphisms and the other confounding factors (age, exposure to randon etc) to the frequency of CA. The preliminary statistical analyses showed that the different gene appeared not to be related to a pronounced increase in chromosome aberration frequencies observed by FISH painting. However, the analysis indicated that the homozygous variant of XRCC3 codon 241 was associated (P<0.05) with two-ways translocations in conjunction with age. Larger studies, both with regard to the cohort and the number of gene variants are needed to elucidate the influence of other DNA repair variants to the yield of chromosomal aberrations. The results indicate that the chromosomal translocations accumulated by age (spontaneous background) may be partly explained by defects in homologous recombination repair. (Author

  12. Genome analysis of DNA repair genes in the alpha proteobacterium Caulobacter crescentus

    Directory of Open Access Journals (Sweden)

    Menck Carlos FM

    2007-03-01

    Full Text Available Abstract Background The integrity of DNA molecules is fundamental for maintaining life. The DNA repair proteins protect organisms against genetic damage, by removal of DNA lesions or helping to tolerate them. DNA repair genes are best known from the gamma-proteobacterium Escherichia coli, which is the most understood bacterial model. However, genome sequencing raises questions regarding uniformity and ubiquity of these DNA repair genes and pathways, reinforcing the need for identifying genes and proteins, which may respond to DNA damage in other bacteria. Results In this study, we employed a bioinformatic approach, to analyse and describe the open reading frames potentially related to DNA repair from the genome of the alpha-proteobacterium Caulobacter crescentus. This was performed by comparison with known DNA repair related genes found in public databases. As expected, although C. crescentus and E. coli bacteria belong to separate phylogenetic groups, many of their DNA repair genes are very similar. However, some important DNA repair genes are absent in the C. crescentus genome and other interesting functionally related gene duplications are present, which do not occur in E. coli. These include DNA ligases, exonuclease III (xthA, endonuclease III (nth, O6-methylguanine-DNA methyltransferase (ada gene, photolyase-like genes, and uracil-DNA-glycosylases. On the other hand, the genes imuA and imuB, which are involved in DNA damage induced mutagenesis, have recently been described in C. crescentus, but are absent in E. coli. Particularly interesting are the potential atypical phylogeny of one of the photolyase genes in alpha-proteobacteria, indicating an origin by horizontal transfer, and the duplication of the Ada orthologs, which have diverse structural configurations, including one that is still unique for C. crescentus. Conclusion The absence and the presence of certain genes are discussed and predictions are made considering the particular

  13. Eukaryotic Mismatch Repair in Relation to DNA Replication.

    Science.gov (United States)

    Kunkel, Thomas A; Erie, Dorothy A

    2015-01-01

    Three processes act in series to accurately replicate the eukaryotic nuclear genome. The major replicative DNA polymerases strongly prevent mismatch formation, occasional mismatches that do form are proofread during replication, and rare mismatches that escape proofreading are corrected by mismatch repair (MMR). This review focuses on MMR in light of increasing knowledge about nuclear DNA replication enzymology and the rate and specificity with which mismatches are generated during leading- and lagging-strand replication. We consider differences in MMR efficiency in relation to mismatch recognition, signaling to direct MMR to the nascent strand, mismatch removal, and the timing of MMR. These studies are refining our understanding of relationships between generating and repairing replication errors to achieve accurate replication of both DNA strands of the nuclear genome.

  14. Preferential repair of DNA double-strand break at the active gene in vivo.

    Science.gov (United States)

    Chaurasia, Priyasri; Sen, Rwik; Pandita, Tej K; Bhaumik, Sukesh R

    2012-10-19

    Previous studies have demonstrated transcription-coupled nucleotide/base excision repair. We report here for the first time that DNA double-strand break (DSB) repair is also coupled to transcription. We generated a yeast strain by introducing a homing (Ho) endonuclease cut site followed by a nucleotide sequence for multiple Myc epitopes at the 3' end of the coding sequence of a highly active gene, ADH1. This yeast strain also contains the Ho cut site at the nearly silent or poorly active mating type α (MATα) locus and expresses Ho endonuclease under the galactose-inducible GAL1 promoter. Using this strain, DSBs were generated at the ADH1 and MATα loci in galactose-containing growth medium that induced HO expression. Subsequently, yeast cells were transferred to dextrose-containing growth medium to stop HO expression, and the DSB repair was monitored at the ADH1 and MATα loci by PCR, using the primer pairs flanking the Ho cut sites. Our results revealed a faster DSB repair at the highly active ADH1 than that at the nearly silent MATα locus, hence implicating a transcription-coupled DSB repair at the active gene in vivo. Subsequently, we extended this study to another gene, PHO5 (carrying the Ho cut site at its coding sequence), under transcriptionally active and inactive growth conditions. We found a fast DSB repair at the active PHO5 gene in comparison to its inactive state. Collectively, our results demonstrate a preferential DSB repair at the active gene, thus supporting transcription-coupled DSB repair in living cells.

  15. Polymorphisms in human DNA repair genes and head and neck squamous cell carcinoma

    Indian Academy of Sciences (India)

    Rim Khlifi; Ahmed Rebai; Amel Hamza-Chaffai

    2012-12-01

    Genetic polymorphisms in some DNA repair proteins are associated with a number of malignant transformations like head and neck squamous cell carcinoma (HNSCC). Xeroderma pigmentosum group D (XPD) and X-ray repair cross-complementing proteins 1 (XRCC1) and 3 (XRCC3) genes are involved in DNA repair and were found to be associated with HNSCC in numerous studies. To establish our overall understanding of possible relationships between DNA repair gene polymorphisms and development of HNSCC, we surveyed the literature on epidemiological studies that assessed potential associations with HNSCC risk in terms of gene–environment interactions, genotype-induced functional defects in enzyme activity and/or protein expression, and the influence of ethnic origin on these associations.We conclude that large, well-designed studies of common polymorphisms in DNA repair genes are needed. Such studies may benefit from analysis of multiple genes or polymorphisms and from the consideration of relevant exposures that may influence the likelihood of HNSCC when DNA repair capacity is reduced.

  16. Assignment of ten DNA repair genes from Schizosaccharomyces pombe to chromosomal NotI restriction fragments

    NARCIS (Netherlands)

    B.C. Broughton; N.C. Barbet; J. Murray (Johanne); F.Z. Watts (Felicity); M.H.M. Koken (Marcel); A.R. Lehmann (Alan); A.M. Carr (Anthony)

    1991-01-01

    textabstractTen DNA repair (rad) genes from the fission yeast, Schizosaccharomyces pombe were mapped to the 17 NotI fragments of the three chromosomes. Nine of the genes map to chromosome I, but there is no evidence for significant clustering.

  17. FISH comets show that the salvage enzyme TK1 contributes to gene-specific DNA repair

    Directory of Open Access Journals (Sweden)

    Stephen eDownes

    2014-08-01

    Full Text Available Thymidine kinase 1 (TK1 is a salvage enzyme that phosphorylates thymidine, imported from surrounding fluids, to create dTMP, which is further phosphorylated to the DNA precursor dTTP. TK1 deficiency has for a long time been known to cause increased cellular sensitivity to DNA damage. We have examined preferential strand break repair of DNA domains in TK1+ and TK1- clones of the Raji cell line, by the Comet-FISH technique, in bulk DNA and in the actively transcribed tumour suppressor (TP53 and human telomerase reverse transcriptase (hTERT gene regions, over 1 hour after 5Gy γ-irradiation. Results showed that repair of the TP53 and hTERT gene regions was more efficient in TK1+ compared to TK1- cells, while levels of genomic DNA repair were consistant between the two cell-lines. The targeted gene-specific repair in TK+ cells occurred rapidly, mainly over the first 15 minute repair-period. Therefore, TK1 is needed for preferential repair of actively transcribed regions, through a previously unsuspected mechanism. In principle, TK1 could exert its protective effects through supply of a supplementary dTTP pool for accurate repair of damaged genes; but Raji TK1+ cells in thymidine free media still show preferential repair of transcribed regions. TK1 therefore does not exert its protective effects through dTTP pools, but through another unidentified mechanism, which affects sensitivity to and mutagenicity by DNA damaging agents.

  18. FISH comets show that the salvage enzyme TK1 contributes to gene-specific DNA repair

    Science.gov (United States)

    McAllister, Katherine A.; Yasseen, Akeel A.; McKerr, George; Downes, C. S.; McKelvey-Martin, Valerie J.

    2014-01-01

    Thymidine kinase 1 (TK1) is a salvage enzyme that phosphorylates thymidine, imported from surrounding fluids, to create dTMP, which is further phosphorylated to the DNA precursor dTTP. TK1 deficiency has for a long time been known to cause increased cellular sensitivity to DNA damage. We have examined preferential strand break repair of DNA domains in TK1+ and TK1- clones of the Raji cell line, by the Comet-FISH technique, in bulk DNA and in the actively transcribed tumor suppressor (TP53) and human telomerase reverse transcriptase (hTERT) gene regions, over 1 h after 5Gy γ-irradiation. Results showed that repair of the TP53 and hTERT gene regions was more efficient in TK1+ compared to TK1- cells, a trend also reflected to a lesser degree in genomic DNA repair between the cell-lines. The targeted gene-specific repair in TK+ cells occurred rapidly, mainly over the first 15 min repair-period. Therefore, TK1 is needed for preferential repair of actively transcribed regions, through a previously unsuspected mechanism. In principle, TK1 could exert its protective effects through supply of a supplementary dTTP pool for accurate repair of damaged genes; but Raji TK1+ cells in thymidine free media still show preferential repair of transcribed regions. TK1 therefore does not exert its protective effects through dTTP pools, but through another unidentified mechanism, which affects sensitivity to and mutagenicity by DNA damaging agents. PMID:25152750

  19. 'Hide-then-hit' to explain the importance of genotypic polymorphism of DNA repair genes in determining susceptibility to cancer

    Institute of Scientific and Technical Information of China (English)

    Pei-Ei Wu; Chen-Yang Shen

    2011-01-01

    Interindividual variations in DNA repair capacity/efficiency linked to the presence of polymorphisms in DNA repair-related genes have been suggested to account for different risk of developing cancers. In this review article, on the basis of breast cancer formation as a model, we propose a 'hide-then-hit' hypothesis indicating the importance of escaping checkpoint surveillance for sub-optimal DNA repair variants to cause cancer. Therefore, only cells with subtle defects in repair capacity arising from low-penetrance variants of DNA repair genes would have the opportunity to grow and accumulate the genetic changes needed for cancer formation, without triggering cell-cycle checkpoint surveillance. Furthermore, distinct from high-penetrance alleles, these polymorphic alleles of DNA repair genes would predispose carriers to a higher risk of developing cancer but would not necessarily cause cancer. To examine this,we simultaneously genotyped multiple SNPs of cell-cycle checkpoint genes and the DNA repair genes. Support for the hypothesis came from observations that breast cancer risk associated with variant genotypes of DNA repair genes became more significant in be confirmed by biological evidence in which a cause-effect relationship has to be established. However, based on this, possible gene-gene interaction is considered to play an important role in modifying the cancer risk associated with genotypic polymorphism of DNA repair gene in different study populations.

  20. Genetic variants of the DNA repair genes from Exome Aggregation Consortium (EXAC) database: significance in cancer.

    Science.gov (United States)

    Das, Raima; Ghosh, Sankar Kumar

    2017-04-01

    DNA repair pathway is a primary defense system that eliminates wide varieties of DNA damage. Any deficiencies in them are likely to cause the chromosomal instability that leads to cell malfunctioning and tumorigenesis. Genetic polymorphisms in DNA repair genes have demonstrated a significant association with cancer risk. Our study attempts to give a glimpse of the overall scenario of the germline polymorphisms in the DNA repair genes by taking into account of the Exome Aggregation Consortium (ExAC) database as well as the Human Gene Mutation Database (HGMD) for evaluating the disease link, particularly in cancer. It has been found that ExAC DNA repair dataset (which consists of 228 DNA repair genes) comprises 30.4% missense, 12.5% dbSNP reported and 3.2% ClinVar significant variants. 27% of all the missense variants has the deleterious SIFT score of 0.00 and 6% variants carrying the most damaging Polyphen-2 score of 1.00, thus affecting the protein structure and function. However, as per HGMD, only a fraction (1.2%) of ExAC DNA repair variants was found to be cancer-related, indicating remaining variants reported in both the databases to be further analyzed. This, in turn, may provide an increased spectrum of the reported cancer linked variants in the DNA repair genes present in ExAC database. Moreover, further in silico functional assay of the identified vital cancer-associated variants, which is essential to get their actual biological significance, may shed some lights in the field of targeted drug development in near future. Copyright © 2017. Published by Elsevier B.V.

  1. The mismatch repair system modulates curcumin sensitivity through induction of DNA strand breaks and activation of G2-M checkpoint.

    Science.gov (United States)

    Jiang, Zhihua; Jin, ShunQian; Yalowich, Jack C; Brown, Kevin D; Rajasekaran, Baskaran

    2010-03-01

    The highly conserved mismatch (MMR) repair system corrects postreplicative errors and modulates cellular responses to genotoxic agents. Here, we show that the MMR system strongly influences cellular sensitivity to curcumin. Compared with MMR-proficient cells, isogenically matched MMR-deficient cells displayed enhanced sensitivity to curcumin. Similarly, cells suppressed for MLH1 or MSH2 expression by RNA interference displayed increased curcumin sensitivity. Curcumin treatment generated comparable levels of reactive oxygen species and the mutagenic adduct 8-oxo-guanine in MMR-proficient and MMR-deficient cells; however, accumulation of gammaH2AX foci, a marker for DNA double-strand breaks (DSB), occurred only in MMR-positive cells in response to curcumin treatment. Additionally, MMR-positive cells showed activation of Chk1 and induction of G(2)-M cell cycle checkpoint following curcumin treatment and inhibition of Chk1 by UCN-01 abrogated Chk1 activation and heightened apoptosis in MMR-proficient cells. These results indicate that curcumin triggers the accumulation of DNA DSB and induction of a checkpoint response through a MMR-dependent mechanism. Conversely, in MMR-compromised cells, curcumin-induced DSB is significantly blunted, and as a result, cells fail to undergo cell cycle arrest, enter mitosis, and die through mitotic catastrophe. The results have potential therapeutic value, especially in the treatment of tumors with compromised MMR function.

  2. Regulation of plant MSH2 and MSH6 genes in the UV-B-induced DNA damage response.

    Science.gov (United States)

    Lario, Luciana D; Ramirez-Parra, Elena; Gutierrez, Crisanto; Casati, Paula; Spampinato, Claudia P

    2011-05-01

    Deleterious effects of UV-B radiation on DNA include the formation of cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidone photoproducts (6-4PPs). These lesions must be repaired to maintain the integrity of DNA and provide genetic stability. Of the several repair systems involved in the recognition and removal of UV-B-induced lesions in DNA, the focus in the present study was on the mismatch repair system (MMR). The contribution of MutSα (MSH2-MSH6) to UV-induced DNA lesion repair and cell cycle regulation was investigated. MSH2 and MSH6 genes in Arabidopsis and maize are up-regulated by UV-B, indicating that MMR may have a role in UV-B-induced DNA damage responses. Analysis of promoter sequences identified MSH6 as a target of the E2F transcription factors. Using electrophoretic mobility shift assays, MSH6 was experimentally validated as an E2F target gene, suggesting an interaction between MMR genes and the cell cycle control. Mutations in MSH2 or MSH6 caused an increased accumulation of CPDs relative to wild-type plants. In addition, msh2 mutant plants showed a different expression pattern of cell cycle marker genes after the UV-B treatment when compared with wild-type plants. Taken together, these data provide evidence that plant MutSα is involved in a UV-B-induced DNA damage response pathway.

  3. Measles, Mumps, Rubella and the MMR Vaccine during Pregnancy

    Science.gov (United States)

    ... in the U.S., but vaccination programs have greatly decreased their incidence. These viruses are still common in ... where a woman received the MMR vaccine during pregnancy. They did not experience adverse complications and there was no increased rate of birth defects. I have heard about a ...

  4. Danish MMR vaccination coverage is considerably higher than reported.

    Science.gov (United States)

    Holt, Nanna; Mygind, Anna; Bro, Flemming

    2017-02-01

    The Danish childhood vaccination programme offers protection against measles, mumps, and rubella (MMR). Nevertheless, many children appear to be unvaccinated according to the national registers. The aim of this study was to estimate the MMR1 vaccination coverage based on a medical record review of children whose vaccination status is negative according to the register-based data. We conducted a cross-sectional study of 19 randomly selected general practices in the Central Denmark Region including 1,712 children aged 18-42 months. The practices received a registration form listing children with a negative MMR1 vaccination status in the register-based data. The general practices then validated the children's vaccination status by medical record review. In total, 94% of the children had been vaccinated according to the medical records in general practice compared with 86% according to the register-based data. Of the 246 children who were unvaccinated according to the register-based data, 135 (55%) had been vaccinated according to the medical records. This discrepancy was due mainly to administrative reimbursement errors. The MMR1 vaccination coverage in Denmark seems to be considerably higher than reflected in national registers. Using medical record review to re-assess the vaccination status revealed that most of the supposedly unvaccinated children had, in fact, been vaccinated. The Danish Research Foundation for General Practice and the General Practitioners' Foundation for Education and Development. not relevant.

  5. Cross-calibration of the Siemens mMR

    DEFF Research Database (Denmark)

    Keller, Sune H; Jakoby, Björn; Svalling, Susanne;

    2016-01-01

    BACKGROUND: We present a quick and easy method to perform quantitatively accurate PET scans of typical water-filled PET plastic shell phantoms on the Siemens Biograph mMR PET/MR system. We perform regular cross-calibrations (Xcal) of our PET systems, including the PET/MR, using a Siemens mCT wate...

  6. Cross-calibration of the Siemens mMR

    DEFF Research Database (Denmark)

    Keller, Sune H; Jakoby, Björn; Svalling, Susanne

    2016-01-01

    BACKGROUND: We present a quick and easy method to perform quantitatively accurate PET scans of typical water-filled PET plastic shell phantoms on the Siemens Biograph mMR PET/MR system. We perform regular cross-calibrations (Xcal) of our PET systems, including the PET/MR, using a Siemens mCT water...

  7. MMR (Measles, Mumps and Rubella) Vaccine: What You Need to Know

    Science.gov (United States)

    ... they would return. 2 Wanhdowshheonu?ld get MMR vaccine Children should get 2 doses of MMR vaccine: • First ... be given at the same time as other vaccines. Children between 1 and 12 years of age can ...

  8. Acquired temozolomide resistance in human glioblastoma cell line U251 is caused by mismatch repair deficiency and can be overcome by lomustine.

    Science.gov (United States)

    Stritzelberger, J; Distel, L; Buslei, R; Fietkau, R; Putz, F

    2017-08-20

    Glioblastoma multiforme (GBM) is the most common malignant primary brain tumor in adults. While the alkylating agent temozolomide (TMZ) has prolonged overall survival, resistance evolution represents an important clinical problem. Therefore, we studied the effectiveness of radiotherapy and CCNU in an in vitro model of acquired TMZ resistance. We studied the MGMT-methylated GBM cell line U251 and its in vitro derived TMZ-resistant subline, U251/TMZ-R. Cytotoxicity of TMZ, CCNU, and radiation was tested. Both cell lines were analyzed for MGMT promotor status and expression of mismatch repair genes (MMR). The influence of MMR inhibition by cadmium chloride (CdCl2) on the effects of both drugs was evaluated. During the resistance evolution process in vitro, U251/TMZ-R developed MMR deficiency, but MGMT status did not change. U251/TMZ-R cells were more resistant to TMZ than parental U251 cells (cell viability: 92.0% in U251/TMZ-R/69.2% in U251; p = 0.032) yet more sensitive to CCNU (56.4%/80.8%; p = 0.023). The effectiveness of radiotherapy was not reduced in the TMZ-resistant cell line. Combination of CCNU and TMZ showed promising results for both cell lines and overcame resistance. CdCl2-induced MMR deficiency increased cytotoxicity of CCNU. Our results confirm MMR deficiency as a crucial process for resistance evolution to TMZ. MMR-deficient TMZ-resistant GBM cells were particularly sensitive to CCNU and to combined CCNU/TMZ. Effectiveness of radiotherapy was preserved in TMZ-resistant cells. Consequently, CCNU might be preferentially considered as a treatment option for recurrent MGMT-methylated GBM and may even be suitable for prevention of resistance evolution in primary treatment.

  9. Gene Expression in Experimental Aortic Coarctation and Repair: Candidate Genes for Therapeutic Intervention?

    Science.gov (United States)

    LaDisa, John F; Bozdag, Serdar; Olson, Jessica; Ramchandran, Ramani; Kersten, Judy R; Eddinger, Thomas J

    2015-01-01

    Coarctation of the aorta (CoA) is a constriction of the proximal descending thoracic aorta and is one of the most common congenital cardiovascular defects. Treatments for CoA improve life expectancy, but morbidity persists, particularly due to the development of chronic hypertension (HTN). Identifying the mechanisms of morbidity is difficult in humans due to confounding variables such as age at repair, follow-up duration, coarctation severity and concurrent anomalies. We previously developed an experimental model that replicates aortic pathology in humans with CoA without these confounding variables, and mimics correction at various times using dissolvable suture. Here we present the most comprehensive description of differentially expressed genes (DEGs) to date from the pathology of CoA, which were obtained using this model. Aortic samples (n=4/group) from the ascending aorta that experiences elevated blood pressure (BP) from induction of CoA, and restoration of normal BP after its correction, were analyzed by gene expression microarray, and enriched genes were converted to human orthologues. 51 DEGs with >6 fold-change (FC) were used to determine enriched Gene Ontology terms, altered pathways, and association with National Library of Medicine Medical Subject Headers (MeSH) IDs for HTN, cardiovascular disease (CVD) and CoA. The results generated 18 pathways, 4 of which (cell cycle, immune system, hemostasis and metabolism) were shared with MeSH ID's for HTN and CVD, and individual genes were associated with the CoA MeSH ID. A thorough literature search further uncovered association with contractile, cytoskeletal and regulatory proteins related to excitation-contraction coupling and metabolism that may explain the structural and functional changes observed in our experimental model, and ultimately help to unravel the mechanisms responsible for persistent morbidity after treatment for CoA.

  10. MMR-Vaccine and Regression in Autism Spectrum Disorders: Negative Results Presented from Japan

    Science.gov (United States)

    Uchiyama, Tokio; Kurosawa, Michiko; Inaba, Yutaka

    2007-01-01

    It has been suggested that the measles, mumps, and rubella vaccine (MMR) is a cause of regressive autism. As MMR was used in Japan only between 1989 and 1993, this time period affords a natural experiment to examine this hypothesis. Data on 904 patients with autism spectrum disorders (ASD) were analyzed. During the period of MMR usage no…

  11. DNA damage and gene therapy of xeroderma pigmentosum, a human DNA repair-deficient disease

    Energy Technology Data Exchange (ETDEWEB)

    Dupuy, Aurélie [Laboratory of Genetic Instability and Oncogenesis UMR8200CNRS, Institut Gustave Roussy and University Paris-Sud, Villejuif (France); Sarasin, Alain, E-mail: alain.sarasin@gustaveroussy.fr [Laboratory of Genetic Instability and Oncogenesis UMR8200CNRS, Institut Gustave Roussy and University Paris-Sud, Villejuif (France); Service de Génétique, Institut Gustave Roussy (France)

    2015-06-15

    Graphical abstract: - Highlights: • Full correction of mutation in the XPC gene by engineered nucleases. • Meganucleases and TALENs are inhibited by 5-MeC for inducing double strand breaks. • Gene therapy of XP cells is possible using homologous recombination for DSB repair. - Abstract: Xeroderma pigmentosum (XP) is a genetic disease characterized by hypersensitivity to ultra-violet and a very high risk of skin cancer induction on exposed body sites. This syndrome is caused by germinal mutations on nucleotide excision repair genes. No cure is available for these patients except a complete protection from all types of UV radiations. We reviewed the various techniques to complement or to correct the genetic defect in XP cells. We, particularly, developed the correction of XP-C skin cells using the fidelity of the homologous recombination pathway during repair of double-strand break (DSB) in the presence of XPC wild type sequences. We used engineered nucleases (meganuclease or TALE nuclease) to induce a DSB located at 90 bp of the mutation to be corrected. Expression of specific TALE nuclease in the presence of a repair matrix containing a long stretch of homologous wild type XPC sequences allowed us a successful gene correction of the original TG deletion found in numerous North African XP patients. Some engineered nucleases are sensitive to epigenetic modifications, such as cytosine methylation. In case of methylated sequences to be corrected, modified nucleases or demethylation of the whole genome should be envisaged. Overall, we showed that specifically-designed TALE-nuclease allowed us to correct a 2 bp deletion in the XPC gene leading to patient's cells proficient for DNA repair and showing normal UV-sensitivity. The corrected gene is still in the same position in the human genome and under the regulation of its physiological promoter. This result is a first step toward gene therapy in XP patients.

  12. Temozolomide Resistance in Glioblastoma Cell Lines: Implication of MGMT, MMR, P-Glycoprotein and CD133 Expression.

    Science.gov (United States)

    Perazzoli, Gloria; Prados, Jose; Ortiz, Raul; Caba, Octavio; Cabeza, Laura; Berdasco, Maria; Gónzalez, Beatriz; Melguizo, Consolación

    2015-01-01

    The use of temozolomide (TMZ) has improved the prognosis for glioblastoma multiforme patients. However, TMZ resistance may be one of the main reasons why treatment fails. Although this resistance has frequently been linked to the expression of O6-methylguanine-DNA methyltransferase (MGMT) it seems that this enzyme is not the only molecular mechanism that may account for the appearance of drug resistance in glioblastoma multiforme patients as the mismatch repair (MMR) complex, P-glycoprotein, and/or the presence of cancer stem cells may also be implicated. Four nervous system tumor cell lines were used to analyze the modulation of MGMT expression and MGMT promoter methylation by TMZ treatment. Furthermore, 5-aza-2'-deoxycytidine was used to demethylate the MGMT promoter and O(6)-benzylguanine to block GMT activity. In addition, MMR complex and P-glycoprotein expression were studied before and after TMZ exposure and correlated with MGMT expression. Finally, the effect of TMZ exposure on CD133 expression was analyzed. Our results showed two clearly differentiated groups of tumor cells characterized by low (A172 and LN229) and high (SF268 and SK-N-SH) basal MGMT expression. Interestingly, cell lines with no MGMT expression and low TMZ IC50 showed a high MMR complex expression, whereas cell lines with high MGMT expression and high TMZ IC50 did not express the MMR complex. In addition, modulation of MGMT expression in A172 and LN229 cell lines was accompanied by a significant increase in the TMZ IC50, whereas no differences were observed in SF268 and SK-N-SH cell lines. In contrast, P-glycoprotein and CD133 was found to be unrelated to TMZ resistance in these cell lines. These results may be relevant in understanding the phenomenon of TMZ resistance, especially in glioblastoma multiforme patients laking MGMT expression, and may also aid in the design of new therapeutic strategies to improve the efficacy of TMZ in glioblastoma multiforme patients.

  13. Noncanonical mismatch repair as a source of genomic instability in human cells

    DEFF Research Database (Denmark)

    Pena Diaz, Javier; Bregenhorn, Stephanie; Ghodgaonkar, Medini;

    2012-01-01

    Mismatch repair (MMR) is a key antimutagenic process that increases the fidelity of DNA replication and recombination. Yet genetic experiments showed that MMR is required for antibody maturation, a process during which the immunoglobulin loci of antigen-stimulated B cells undergo extensive mutage...

  14. A multistep genomic screen identifies new genes required for repair of DNA double-strand breaks in Saccharomyces cerevisiae.

    Science.gov (United States)

    McKinney, Jennifer Summers; Sethi, Sunaina; Tripp, Jennifer DeMars; Nguyen, Thuy N; Sanderson, Brian A; Westmoreland, James W; Resnick, Michael A; Lewis, L Kevin

    2013-04-15

    Efficient mechanisms for rejoining of DNA double-strand breaks (DSBs) are vital because misrepair of such lesions leads to mutation, aneuploidy and loss of cell viability. DSB repair is mediated by proteins acting in two major pathways, called homologous recombination and nonhomologous end-joining. Repair efficiency is also modulated by other processes such as sister chromatid cohesion, nucleosome remodeling and DNA damage checkpoints. The total number of genes influencing DSB repair efficiency is unknown. To identify new yeast genes affecting DSB repair, genes linked to gamma radiation resistance in previous genome-wide surveys were tested for their impact on repair of site-specific DSBs generated by in vivo expression of EcoRI endonuclease. Eight members of the RAD52 group of DNA repair genes (RAD50, RAD51, RAD52, RAD54, RAD55, RAD57, MRE11 and XRS2) and 73 additional genes were found to be required for efficient repair of EcoRI-induced DSBs in screens utilizing both MATa and MATα deletion strain libraries. Most mutants were also sensitive to the clastogenic chemicals MMS and bleomycin. Several of the non-RAD52 group genes have previously been linked to DNA repair and over half of the genes affect nuclear processes. Many proteins encoded by the protective genes have previously been shown to associate physically with each other and with known DNA repair proteins in high-throughput proteomics studies. A majority of the proteins (64%) share sequence similarity with human proteins, suggesting that they serve similar functions. We have used a genetic screening approach to detect new genes required for efficient repair of DSBs in Saccharomyces cerevisiae. The findings have spotlighted new genes that are critical for maintenance of genome integrity and are therefore of greatest concern for their potential impact when the corresponding gene orthologs and homologs are inactivated or polymorphic in human cells.

  15. Polymorphisms in base excision repair genes: Breast cancer risk and individual radiosensitivity

    Science.gov (United States)

    Patrono, Clarice; Sterpone, Silvia; Testa, Antonella; Cozzi, Renata

    2014-01-01

    Breast cancer (BC) is the most common cancer among women worldwide. The aetiology and carcinogenesis of BC are not clearly defined, although genetic, hormonal, lifestyle and environmental risk factors have been established. The most common treatment for BC includes breast-conserving surgery followed by a standard radiotherapy (RT) regimen. However, radiation hypersensitivity and the occurrence of RT-induced toxicity in normal tissue may affect patients’ treatment. The role of DNA repair in cancer has been extensively investigated, and an impaired DNA damage response may increase the risk of BC and individual radiosensitivity. Single nucleotide polymorphisms (SNPs) in DNA repair genes may alter protein function and modulate DNA repair efficiency, influencing the development of various cancers, including BC. SNPs in DNA repair genes have also been studied as potential predictive factors for the risk of RT-induced side effects. Here, we review the literature on the association between SNPs in base excision repair (BER) genes and BC risk. We focused on X-ray repair cross complementing group 1 (XRCC1), which plays a key role in BER, and on 8-oxoguanine DNA glycosylase 1, apurinic/apyrimidinic endonuclease 1 and poly (ADP-ribose) polymerase-1, which encode three important BER enzymes that interact with XRCC1. Although no association between SNPs and radiation toxicity has been validated thus far, we also report published studies on XRCC1 SNPs and variants in other BER genes and RT-induced side effects in BC patients, emphasising that large well-designed studies are needed to determine the genetic components of individual radiosensitivity. PMID:25493225

  16. Gene therapy and peripheral nerve repair : a perspective

    NARCIS (Netherlands)

    Hoyng, Stefan A; de Winter, Fred; Tannemaat, Martijn R; Blits, Bas; Malessy, Martijn J A; Verhaagen, J.

    2015-01-01

    Clinical phase I/II studies have demonstrated the safety of gene therapy for a variety of central nervous system disorders, including Canavan's, Parkinson's (PD) and Alzheimer's disease (AD), retinal diseases and pain. The majority of gene therapy studies in the CNS have used adeno-associated viral

  17. Gene therapy and peripheral nerve repair : a perspective

    NARCIS (Netherlands)

    Hoyng, Stefan A; de Winter, Fred; Tannemaat, Martijn R; Blits, Bas; Malessy, Martijn J A; Verhaagen, J.

    2015-01-01

    Clinical phase I/II studies have demonstrated the safety of gene therapy for a variety of central nervous system disorders, including Canavan's, Parkinson's (PD) and Alzheimer's disease (AD), retinal diseases and pain. The majority of gene therapy studies in the CNS have used adeno-associated viral

  18. Cloning of human and mouse genes homologous to RAD52, a yeast gene involved in DNA repair and recombination.

    NARCIS (Netherlands)

    D.F.R. Muris; O.Y. Bezzubova (Olga); J-M. Buerstedde; K. Vreeken; A.S. Balajee; C.J. Osgood; C. Troelstra (Christine); J.H.J. Hoeijmakers (Jan); K. Ostermann; H. Schmidt (Henning); A.T. Natarajan; J.C.J. Eeken; P.H.M. Lohmann (Paul); A. Pastink (Albert)

    1994-01-01

    textabstractThe RAD52 gene of Saccharomyces cerevisiae is required for recombinational repair of double-strand breaks. Using degenerate oligonucleotides based on conserved amino acid sequences of RAD52 and rad22, its counterpart from Schizosaccharomyces pombe, RAD52 homologs from man and mouse were

  19. Chromosomal localization of three repair genes: the xeroderma pigmentosum group C gene and two human homologs of yeast RAD23.

    NARCIS (Netherlands)

    P.J. van der Spek (Peter); E.M.E. Smit (Elisabeth); H.B. Beverloo (Berna); K. Sugasawa (Kaoru); C. Matsutani; F. Hanaoka (Fumio); J.H.J. Hoeijmakers (Jan); A. Hagemeier

    1994-01-01

    textabstractThe nucleotide excision repair (NER) disorder xeroderma pigmentosum (XP) is characterized by sun (UV) sensitivity, predisposition to skin cancer, and extensive genetic heterogeneity. Recently, we reported the cloning and analysis of three human NER genes, XPC, HHR23A, and HHR23B. The

  20. Antibody persistence in young adults 1 year after MMR immunization by aerosol or by subcutaneous route.

    Science.gov (United States)

    Díaz-Ortega, José Luis; Bennett, John V; Castañeda, D; Martinez, D; de Castro, J Fernandez

    2010-10-18

    Information on antibody persistence after aerosol revaccination with MMR components is limited. Thus, antibody titers were determined in 283 adult participants in a MMR vaccine trial 12 months after revaccination. One group had received aerosolized Triviraten vaccine while two other groups received either injected Triviraten or MMR II vaccine. Both MMR vaccines contained the same rubella strain, but different measles and mumps strains. Seropositivity to measles persisted in 98% of aerosolized vaccine recipients, 92% of injected Triviraten, and 95% of injected MMR II. All participants in the three groups retained seropositivity to rubella, while less than 50% remained seropositive to mumps. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Structural and functional conservation of two human homologs of the yeast DNA repair gene RAD6.

    NARCIS (Netherlands)

    M.H.M. Koken (Marcel); P. Reynolds (Paul); I. Jaspers-Dekker (Iris); L. Prakash; S. Prakash; D. Bootsma (Dirk); J.H.J. Hoeijmakers (Jan)

    1991-01-01

    textabstractThe RAD6 gene of Saccharomyces cerevisiae encodes a ubiquitin-conjugating enzyme (E2) that is required for DNA repair, damage-induced mutagenesis, and sporulation. We have cloned the two human RAD6 homologs, designated HHR6A and HHR6B. The two 152-amino acid human proteins share 95% sequ

  2. Comprehensive analysis of DNA repair gene variants and risk of meningioma

    DEFF Research Database (Denmark)

    Bethke, L.; Murray, A.; Webb, E.

    2008-01-01

    of meningioma and exposure to ionizing radiation is also well known and led us to examine whether variants in DNA repair genes contribute to disease susceptibility. METHODS: We analyzed 1127 tagging single-nucleotide polymorphisms (SNPs) that were selected to capture most of the common variation in 136 DNA...

  3. Semiconservative replication, genetic repair, and many-gened genomes: Extending the quasispecies paradigm to living systems

    Science.gov (United States)

    Tannenbaum, Emmanuel; Shakhnovich, Eugene I.

    2005-12-01

    Quasispecies theory has emerged as an important tool for modeling the evolutionary dynamics of biological systems. We review recent advances in the field, with an emphasis on the quasispecies dynamics of semiconservatively replicating genomes. Applications to cancer and adult stem cell growth are discussed. Additional topics, such as genetic repair and many-gene genomes, are covered as well.

  4. Assessing pathogenicity of MLH1 variants by co-expression of human MLH1 and PMS2 genes in yeast

    Directory of Open Access Journals (Sweden)

    Hudler Petra

    2009-10-01

    Full Text Available Abstract Background Loss of DNA mismatch repair (MMR in humans, mainly due to mutations in the hMLH1 gene, is linked to hereditary nonpolyposis colorectal cancer (HNPCC. Because not all MLH1 alterations result in loss of MMR function, accurate characterization of variants and their classification in terms of their effect on MMR function is essential for reliable genetic testing and effective treatment. To date, in vivo assays for functional characterization of MLH1 mutations performed in various model systems have used episomal expression of the modified MMR genes. We describe here a novel approach to determine accurately the functional significance of hMLH1 mutations in vivo, based on co-expression of human MLH1 and PMS2 in yeast cells. Methods Yeast MLH1 and PMS1 genes, whose protein products form the MutLα complex, were replaced by human orthologs directly on yeast chromosomes by homologous recombination, and the resulting MMR activity was tested. Results The yeast strain co-expressing hMLH1 and hPMS2 exhibited the same mutation rate as the wild-type. Eight cancer-related MLH1 variants were introduced, using the same approach, into the prepared yeast model, and their effect on MMR function was determined. Five variants (A92P, S93G, I219V, K618R and K618T were classified as non-pathogenic, whereas variants T117M, Y646C and R659Q were characterized as pathogenic. Conclusion Results of our in vivo yeast-based approach correlate well with clinical data in five out of seven hMLH1 variants and the described model was thus shown to be useful for functional characterization of MLH1 variants in cancer patients found throughout the entire coding region of the gene.

  5. Loss of transcription factor early growth response gene 1 results in impaired endochondral bone repair.

    Science.gov (United States)

    Reumann, Marie K; Strachna, Olga; Yagerman, Sarah; Torrecilla, Daniel; Kim, Jihye; Doty, Stephen B; Lukashova, Lyudmila; Boskey, Adele L; Mayer-Kuckuk, Philipp

    2011-10-01

    Transcription factors that play a role in ossification during development are expected to participate in postnatal fracture repair since the endochondral bone formation that occurs in embryos is recapitulated during fracture repair. However, inherent differences exist between bone development and fracture repair, including a sudden disruption of tissue integrity followed by an inflammatory response. This raises the possibility that repair-specific transcription factors participate in bone healing. Here, we assessed the consequence of loss of early growth response gene 1 (EGR-1) on endochondral bone healing because this transcription factor has been shown to modulate repair in vascularized tissues. Model fractures were created in ribs of wild type (wt) and EGR-1(-/-) mice. Differences in tissue morphology and composition between these two animal groups were followed over 28 post fracture days (PFDs). In wt mice, bone healing occurred in healing phases characteristic of endochondral bone repair. A similar healing sequence was observed in EGR-1(-/-) mice but was impaired by alterations. A persistent accumulation of fibrin between the disconnected bones was observed on PFD7 and remained pronounced in the callus on PFD14. Additionally, the PFD14 callus was abnormally enlarged and showed increased deposition of mineralized tissue. Cartilage ossification in the callus was associated with hyper-vascularity and -proliferation. Moreover, cell deposits located in proximity to the callus within skeletal muscle were detected on PFD14. Despite these impairments, repair in EGR-1(-/-) callus advanced on PFD28, suggesting EGR-1 is not essential for healing. Together, this study provides genetic evidence that EGR-1 is a pleiotropic regulator of endochondral fracture repair. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Polymorphisms in DNA Repair Genes and MDR1 and the Risk for Non-Hodgkin Lymphoma

    Directory of Open Access Journals (Sweden)

    Hee Nam Kim

    2014-04-01

    Full Text Available The damage caused by oxidative stress and exposure to cigarette smoke and alcohol necessitate DNA damage repair and transport by multidrug resistance-1 (MDR1. To explore the association between polymorphisms in these genes and non-Hodgkin lymphoma risk, we analyzed 15 polymorphisms of 12 genes in a population-based study in Korea (694 cases and 1700 controls. Four genotypes of DNA repair pathway genes (XRCC1 399 GA, OGG1 326 GG, BRCA1 871 TT, and WRN 787 TT were associated with a decreased risk for NHL [odds ratio (ORXRCC1 GA = 0.80, p = 0.02; OROGG1 GG = 0.70, p = 0.008; ORBRCA1 TT = 0.71, p = 0.048; ORWRN TT = 0.68, p = 0.01]. Conversely, the MGMT 115 CT genotype was associated with an increased risk for NHL (OR = 1.25, p = 0.04. In the MDR1 gene, the 1236 CC genotype was associated with a decreased risk for NHL (OR = 0.74, p = 0.04, and the 3435 CT and TT genotypes were associated with an increased risk (OR3435CT = 1.50, p < 0.0001; OR3435TT = 1.43, p = 0.02. These results suggest that polymorphisms in the DNA repair genes XRCC1, OGG1, BRCA1, WRN1, and MGMT and in the MDR1 gene may affect the risk for NHL in Korean patients.

  7. Cytogenetic Response to Ionizing Radiation Exposure in Human Fibroblasts with Suppressed Expression of Non-DSB Repair Genes

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry H.; Emami, Kamal; Hammond, Dianne; Mehta, Satish K.; Jeevarajan, Antony S.; Pierson, Duane L.; Wu, Honglu

    2009-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in double-strand break (DSB) repair, and its impact on cytogenetic responses has not been well studied. The purpose of this study is to identify new roles of IR inducible genes in radiation-induced chromosome aberrations and micronuclei formation. In the study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by small interfering RNA in human fibroblast cells. Frequencies of micronuclei (MN) formation and chromosome aberrations were measured to determine the efficiency of cytogenetic repair, and the fraction of bi-nucleated cells in the MN analysis was used as a marker for cell cycle progression. In response to gamma radiation, the formation of MN was significantly increased by suppressed expression of five genes: Ku70 (DSB repair pathway), XPA (nucleotide excision repair pathway), RPA1 (mismatch repair pathway), RAD17 and RBBP8 (cell cycle control). Knocked-down expression of four genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Moreover, decreased XPA, p21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Nine of these eleven genes, whose knock-down expression affected cytogenetic repair, were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate IR

  8. Cytogenetic Response to Ionizing Radiation Exposure in Human Fibroblasts with Suppressed Expression of Non-DSB Repair Genes

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry H.; Emami, Kamal; Hammond, Dianne; Mehta, Satish K.; Jeevarajan, Antony S.; Pierson, Duane L.; Wu, Honglu

    2009-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in double-strand break (DSB) repair, and its impact on cytogenetic responses has not been well studied. The purpose of this study is to identify new roles of IR inducible genes in radiation-induced chromosome aberrations and micronuclei formation. In the study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by small interfering RNA in human fibroblast cells. Frequencies of micronuclei (MN) formation and chromosome aberrations were measured to determine the efficiency of cytogenetic repair, and the fraction of bi-nucleated cells in the MN analysis was used as a marker for cell cycle progression. In response to gamma radiation, the formation of MN was significantly increased by suppressed expression of five genes: Ku70 (DSB repair pathway), XPA (nucleotide excision repair pathway), RPA1 (mismatch repair pathway), RAD17 and RBBP8 (cell cycle control). Knocked-down expression of four genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Moreover, decreased XPA, p21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Nine of these eleven genes, whose knock-down expression affected cytogenetic repair, were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate IR

  9. Mutagen sensitivity and DNA repair of the EGFR gene in oropharyngeal cancer.

    Science.gov (United States)

    Reiter, Maximilian; Welz, Christian; Baumeister, Philipp; Schwenk-Zieger, Sabina; Harréus, Ulrich

    2010-07-01

    Epidermal growth factor receptor (EGFR) is overexpressed in several epithelial malignancies, including head and neck squamous cell cancer. Up to 90% of the tumour cases in this area exhibit EGFR overexpression. The reasons for overexpression are still not clear. Mutagen sensitivity, pre-existing conditions for genotoxic damage, gene amplification, and reduced DNA repair of the EGFR gene are possible causes for EGFR protein overexpression. DNA damage in macroscopically healthy pharyngeal mucosal tissue of 30 patients with (15) and without cancer (15) of the oropharynx was evaluated after incubation with Benz[a]pyren-7,8-diol-9,10-epoxid (BPDE), a tobacco-associated carcinogen. Emerging DNA fragmentation of the EGFR gene located on chromosome 7 was evaluated. The centromere of the chromosome served as a reference gene. Comet FISH was applied to assess the mutagen sensitivity in these regions. The extent of DNA repair was evaluated in the same samples after a 24-h repair-period. Differences in gene amplification and protein expression between the two groups were analysed by Interphase-FISH (I-FISH) and immunohistochemistry (IHC), respectively. BPDE caused significant DNA damage compared to the negative control in oropharyngeal mucosa cells of patients with- and without carcinoma. DNA fragmentation of the EGFR gene in the two groups was comparable. Mutagen sensitivity was significantly higher in the EGFR gene than in the reference gene, but fragmentation of the EGFR gene was not enhanced compared to the DNA damage of the entire DNA. The DNA repair period led to a significant reduction in DNA damage levels in all groups, without preference for any of the groups or genes. EGFR amplification was found in 7.7% of the tumour patients but not in control patients. Of the patients with oropharyngeal carcinoma, 66.6% showed enhanced expression of EGFR protein (grades 2 and 3), whereas only 13% of tumour-free patients showed such protein expression. No significant differences in

  10. Evaluating the effects of genetic variants of DNA repair genes using cytogenetic mutagen sensitivity approaches.

    Science.gov (United States)

    Abdel-Rahman, Sherif Z; El-Zein, Randa A

    2011-08-01

    Mutagen sensitivity, measured in short-term cultures of peripheral blood lymphocytes by cytogenetic endpoints, is an indirect measure for DNA repair capacity and has been used for many years as a biomarker for intrinsic susceptibility for cancer. In this article, we briefly give an overview of the different cytogenetic mutagen sensitivity approaches that have been used successfully to evaluate the biological effects of polymorphisms in DNA repair genes based on a current review of the literature and based on the need for biomarkers that would allow the characterization of the biological and functional significance of such polymorphisms. We also address some of the future challenges facing this emerging area of research.

  11. Complementary analysis of microsatellite tumor profile and mismatch repair defects in colorectal carcinomas

    Institute of Scientific and Technical Information of China (English)

    Alfredo Blanes; Salvador J Diaz-Cano

    2006-01-01

    Microsatellite instability (MSI) is a prognostic factor and a marker of deficient mismatch repair (MMR) in colorectal adenocarcinomas (CRC). However, a proper application of this marker requires understanding the following: (1)The MSI concept: The PCR approach must amplify the correct locus and accurately identify the microsatellite pattern in the patient's normal tissue. MSI is demonstrated when the length of DNA sequences in a tumor differs from that of nontumor tissue. Any anomalous expansion or reduction of tandem repeats results in extra-bands normally located in the expected size range (100 bp,above or below the expected product), differ from the germline pattern by some multiple of the repeating unit,and must show appropriate stutter. (2) MSI mechanisms:MMR gene inactivation (by either mutation or protein down-regulation as frequently present in deep CRC compartments) leads to mutation accumulation in a cell with every cellular division, resulting in malignant transformation. These mechanisms can express tumor progression and result in a decreased prevalence of aneuploid cells and loss of the physiologic cell kinetic correlations in the deep CRC compartments. MSI molecular mechanisms are not necessarily independent from chromosomal instability and may coexist in a given CRC. (3) Because of intratumoural heterogeneity, at least two samples from each CRC should be screened, preferably from the superficial (tumor cells above the muscularis propria) and deep (tumor cells infiltrating the muscularis propria) CRC compartments to cover the topographic tumor heterogeneity. (4) Pathologists play a critical role in identifying microsatellite-unstable CRC, such as occur in young patients with synchronous or metachronous tumors or with tumors showing classic histologic features. In these cases, MSI testing and/or MMR immunohistochemistry are advisable, along with gene sequencing and genetic counseling if appropriate. MSI is an excellent functional and prognostically

  12. Exonuclease 1 and its versatile roles in DNA repair

    DEFF Research Database (Denmark)

    Keijzers, Guido; Liu, Dekang; Rasmussen, Lene Juel

    2016-01-01

    Exonuclease 1 (EXO1) is a multifunctional 5' → 3' exonuclease and a DNA structure-specific DNA endonuclease. EXO1 plays roles in DNA replication, DNA mismatch repair (MMR) and DNA double-stranded break repair (DSBR) in lower and higher eukaryotes and contributes to meiosis, immunoglobulin...... maturation, and micro-mediated end-joining in higher eukaryotes. In human cells, EXO1 is also thought to play a role in telomere maintenance. Mutations in the human EXO1 gene correlate with increased susceptibility to some cancers. This review summarizes recent studies on the enzymatic functions...... and biological roles of EXO1, its possible protective role against cancer and aging, and regulation of EXO1 by posttranslational modification....

  13. Low-level infrared laser modulates muscle repair and chromosome stabilization genes in myoblasts.

    Science.gov (United States)

    da Silva Neto Trajano, Larissa Alexsandra; Stumbo, Ana Carolina; da Silva, Camila Luna; Mencalha, Andre Luiz; Fonseca, Adenilson S

    2016-08-01

    Infrared laser therapy is used for skeletal muscle repair based on its biostimulative effect on satellite cells. However, shortening of telomere length limits regenerative potential in satellite cells, which occurs after each cell division cycle. Also, laser therapy could be more effective on non-physiologic tissues. This study evaluated low-level infrared laser exposure effects on mRNA expression from muscle injury repair and telomere stabilization genes in myoblasts in normal and stressful conditions. Laser fluences were those used in clinical protocols. C2C12 myoblast cultures were exposed to low-level infrared laser (10, 35, and 70 J/cm(2)) in standard or normal (10 %) and reduced (2 %) fetal bovine serum concentrations; total RNA was extracted for mRNA expression evaluation from muscle injury repair (MyoD and Pax7) and chromosome stabilization (TRF1 and TRF2) genes by real time quantitative polymerization chain reaction. Data show that low-level infrared laser increases the expression of MyoD and Pax7 in 10 J/cm(2) fluence, TRF1 expression in all fluences, and TRF2 expression in 70 J/cm(2) fluence in both 10 and 2 % fetal bovine serum. Low-level infrared laser increases mRNA expression from genes related to muscle repair and telomere stabilization in myoblasts in standard or normal and stressful conditions.

  14. Enhanced gene repair mediated by methyl-CpG-modified single-stranded oligonucleotides

    Science.gov (United States)

    Bertoni, Carmen; Rustagi, Arjun; Rando, Thomas A.

    2009-01-01

    Gene editing mediated by oligonucleotides has been shown to induce stable single base alterations in genomic DNA in both prokaryotic and eukaryotic organisms. However, the low frequencies of gene repair have limited its applicability for both basic manipulation of genomic sequences and for the development of therapeutic approaches for genetic disorders. Here, we show that single-stranded oligodeoxynucleotides (ssODNs) containing a methyl-CpG modification and capable of binding to the methyl-CpG binding domain protein 4 (MBD4) are able to induce >10-fold higher levels of gene correction than ssODNs lacking the specific modification. Correction was stably inherited through cell division and was confirmed at the protein, transcript and genomic levels. Downregulation of MBD4 expression using RNAi prevented the enhancement of gene correction efficacy obtained using the methyl-CpG-modified ssODN, demonstrating the specificity of the repair mechanism being recruited. Our data demonstrate that efficient manipulation of genomic targets can be achieved and controlled by the type of ssODN used and by modulation of the repair mechanism involved in the correction process. This new generation of ssODNs represents an important technological advance that is likely to have an impact on multiple applications, especially for gene therapy where permanent correction of the genetic defect has clear advantages over viral and other nonviral approaches currently being tested. PMID:19854937

  15. DNA-repair gene variants are associated with glioblastoma survival

    DEFF Research Database (Denmark)

    Wibom, Carl; Sjöström, Sara; Henriksson, Roger

    2012-01-01

    genes, in 138 glioblastoma samples from Sweden and Denmark. We confirmed our findings in an independent cohort of 121 glioblastoma patients from the UK. Our analysis revealed nine SNPs annotating MSH2, RAD51L1 and RECQL4 that were significantly (p

  16. Gene expression signatures for colorectal cancer microsatellite status and HNPCC

    DEFF Research Database (Denmark)

    Kruhøffer, M; Jensen, J L; Laiho, P;

    2005-01-01

    The majority of microsatellite instable (MSI) colorectal cancers are sporadic, but a subset belongs to the syndrome hereditary non-polyposis colorectal cancer (HNPCC). Microsatellite instability is caused by dysfunction of the mismatch repair (MMR) system that leads to a mutator phenotype, and MSI...... of 101 stage II and III colorectal cancers (34 MSI, 67 microsatellite stable (MSS)) using high-density oligonucleotide microarrays. From these data, we constructed a nine-gene signature capable of separating the mismatch repair proficient and deficient tumours. Subsequently, we demonstrated...

  17. Chromosomal localization of three repair genes: The xeroderma pigmentosum group C gene and two human homologs of yeast RAD23

    Energy Technology Data Exchange (ETDEWEB)

    Spek, P.J. van der; Smit, E.M.E.; Beverloo, H.B. [Erasmus Univ., Rotterdam (Netherlands)] [and others

    1994-10-01

    The nucleotide excision repair (NER) disorder xeroderma pigmentosum (XP) is characterized by sun (UV) sensitivity, predisposition to skin cancer, and extensive genetic heterogeneity. Recently, we reported the cloning and analysis of three human NER genes, XPC, HHR23A, and HHR23B. The previously cloned XPC gene is involved in the common XP complementation group C, which is defective in excision repair of nontranscribed sequences in the genome. The XPC protein was found to be complexed with the product of HHR23B, one of the two human homologs of the Saccharomyes cerevisiae NER gene RAD23. Here we present the chromosomal localization by in situ hybridization using haptenized probes of all three genes. The HHR23A gene was assigned to chromosome 19p13.2. Interestingly, the HHR23B and XPC genes, the product of which forms a tight complex, were found to colocalize on band 3p25.1. Pulsed-field gel electrophoresis revealed that the HHR23B and XPC genes possibly share a MluI restriction fragment of about 625 kb. Potential involvement of the HHR23 genes in human genetic disorders is discussed. 53 refs., 4 figs., 2 tabs.

  18. Transcriptional and post-transcriptional regulation of nucleotide excision repair genes in human cells

    Energy Technology Data Exchange (ETDEWEB)

    Lefkofsky, Hailey B. [Translational Oncology Program, University of Michigan Medical School, Ann Arbor, MI (United States); Veloso, Artur [Translational Oncology Program, University of Michigan Medical School, Ann Arbor, MI (United States); Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI (United States); Bioinformatics Program, Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI (United States); Ljungman, Mats, E-mail: ljungman@umich.edu [Translational Oncology Program, University of Michigan Medical School, Ann Arbor, MI (United States); Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI (United States); Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI (United States)

    2015-06-15

    Nucleotide excision repair (NER) removes DNA helix-distorting lesions induced by UV light and various chemotherapeutic agents such as cisplatin. These lesions efficiently block the elongation of transcription and need to be rapidly removed by transcription-coupled NER (TC-NER) to avoid the induction of apoptosis. Twenty-nine genes have been classified to code for proteins participating in nucleotide excision repair (NER) in human cells. Here we explored the transcriptional and post-transcriptional regulation of these NER genes across 13 human cell lines using Bru-seq and BruChase-seq, respectively. Many NER genes are relatively large in size and therefore will be easily inactivated by UV-induced transcription-blocking lesions. Furthermore, many of these genes produce transcripts that are rather unstable. Thus, these genes are expected to rapidly lose expression leading to a diminished function of NER. One such gene is ERCC6 that codes for the CSB protein critical for TC-NER. Due to its large gene size and high RNA turnover rate, the ERCC6 gene may act as dosimeter of DNA damage so that at high levels of damage, ERCC6 RNA levels would be diminished leading to the loss of CSB expression, inhibition of TC-NER and the promotion of cell death.

  19. Ultraviolet damage, DNA repair and vitamin D in nonmelanoma skin cancer and in malignant melanoma: an update.

    Science.gov (United States)

    Reichrath, Jörg; Rass, Knuth

    2014-01-01

    -induced tumorigenesis of melanoma and nonmelanoma skin cancer. An interesting new perspective in DNA damage and repair research lies in the participation of mammalian mismatch repair (MMR) in UV damage correction. As MMR enzyme hMSH2 displays a p53 target gene, is induced by UVB radiation and is involved in NER pathways, studies have now been initiated to elucidate the physiological and pathophysiological role of MMR in malignant melanoma and nonmelanoma skin cancer development. Interestingly, increasing evidence now demonstrates an important function of the vitamin D endocrine system (VDES) for prevention of BCC, SCC and melanoma, identifying the vitamin D receptor as a tumor suppressor in the skin.

  20. Randomised cluster trial to support informed parental decision-making for the MMR vaccine

    Directory of Open Access Journals (Sweden)

    Bekker Hilary

    2011-06-01

    Full Text Available Abstract Background In the UK public concern about the safety of the combined measles, mumps and rubella [MMR] vaccine continues to impact on MMR coverage. Whilst the sharp decline in uptake has begun to level out, first and second dose uptake rates remain short of that required for population immunity. Furthermore, international research consistently shows that some parents lack confidence in making a decision about MMR vaccination for their children. Together, this work suggests that effective interventions are required to support parents to make informed decisions about MMR. This trial assessed the impact of a parent-centred, multi-component intervention (balanced information, group discussion, coaching exercise on informed parental decision-making for MMR. Methods This was a two arm, cluster randomised trial. One hundred and forty two UK parents of children eligible for MMR vaccination were recruited from six primary healthcare centres and six childcare organisations. The intervention arm received an MMR information leaflet and participated in the intervention (parent meeting. The control arm received the leaflet only. The primary outcome was decisional conflict. Secondary outcomes were actual and intended MMR choice, knowledge, attitude, concern and necessity beliefs about MMR and anxiety. Results Decisional conflict decreased for both arms to a level where an 'effective' MMR decision could be made one-week (effect estimate = -0.54, p Conclusions Whilst both the leaflet and the parent meeting reduced parents' decisional conflict, the parent meeting appeared to enable parents to act upon their decision leading to vaccination uptake.

  1. A data mining approach for classifying DNA repair genes into ageing-related or non-ageing-related

    Directory of Open Access Journals (Sweden)

    Vasieva Olga

    2011-01-01

    Full Text Available Abstract Background The ageing of the worldwide population means there is a growing need for research on the biology of ageing. DNA damage is likely a key contributor to the ageing process and elucidating the role of different DNA repair systems in ageing is of great interest. In this paper we propose a data mining approach, based on classification methods (decision trees and Naive Bayes, for analysing data about human DNA repair genes. The goal is to build classification models that allow us to discriminate between ageing-related and non-ageing-related DNA repair genes, in order to better understand their different properties. Results The main patterns discovered by the classification methods are as follows: (a the number of protein-protein interactions was a predictor of DNA repair proteins being ageing-related; (b the use of predictor attributes based on protein-protein interactions considerably increased predictive accuracy of attributes based on Gene Ontology (GO annotations; (c GO terms related to "response to stimulus" seem reasonably good predictors of ageing-relatedness for DNA repair genes; (d interaction with the XRCC5 (Ku80 protein is a strong predictor of ageing-relatedness for DNA repair genes; and (e DNA repair genes with a high expression in T lymphocytes are more likely to be ageing-related. Conclusions The above patterns are broadly integrated in an analysis discussing relations between Ku, the non-homologous end joining DNA repair pathway, ageing and lymphocyte development. These patterns and their analysis support non-homologous end joining double strand break repair as central to the ageing-relatedness of DNA repair genes. Our work also showcases the use of protein interaction partners to improve accuracy in data mining methods and our approach could be applied to other ageing-related pathways.

  2. DNA Repair Gene Polymorphisms in Relation to Non-Small Cell Lung Cancer Survival

    Directory of Open Access Journals (Sweden)

    Yuliang Su

    2015-07-01

    Full Text Available Background: Single nucleotide polymorphisms (SNPs in the DNA repair genes are suspected to be related to the survival of lung cancer patients due to their possible influence on DNA repair capacity (DRC. However, the study results are inconsistent. Methods: A follow-up study of 610 non-small cell lung cancer (NSCLC patients was conducted to investigate genetic polymorphisms associated with the DNA repair genes in relation to NSCLC survival; 6 SNPs were genotyped, including XRCC1 (rs25487 G>A, hOGG1 (rs1052133 C>G, MUTYH (rs3219489 G>C, XPA (rs1800975 G>A, ERCC2 (rs1799793 G>A and XRCC3 (rs861539 C>T. Kaplan-Meier survival curve and Cox proportional hazards regression analyses were performed. SNP-SNP interaction was also examined using the survival tree analysis. Results: Advanced disease stage and older age at diagnosis were associated with poor prognosis of NSCLC. Patients with the variant ‘G' allele of hOGG1 rs1052133 had poor overall survival compared with those with the homozygous wild ‘CC' genotype, especially in female patients, adenocarcinoma histology, early stage, light smokers and without family history of cancer. For never smoking female lung cancer patients, individuals carrying homozygous variant ‘AA' genotype of XPA had shorter survival time compared to those with wild ‘G' alleles. Furthermore, females carrying homozygous variant XPA and hOGG1 genotypes simultaneously had 2.78-fold increased risk for death. Among all 6 polymorphisms, the homozygous variant ‘AA' of XPA carriers had poor prognosis compared to the carriers of wild ‘G' alleles of XPA together with other base excision repair (BER polymorphisms. Conclusions: Besides disease stage and age, the study found DNA repair gene polymorphisms were associated with lung cancer survival.

  3. Germline mutations in DNA repair genes predispose asbestos-exposed patients to malignant pleural mesothelioma.

    Science.gov (United States)

    Betti, Marta; Casalone, Elisabetta; Ferrante, Daniela; Aspesi, Anna; Morleo, Giulia; Biasi, Alessandra; Sculco, Marika; Mancuso, Giuseppe; Guarrera, Simonetta; Righi, Luisella; Grosso, Federica; Libener, Roberta; Pavesi, Mansueto; Mariani, Narciso; Casadio, Caterina; Boldorini, Renzo; Mirabelli, Dario; Pasini, Barbara; Magnani, Corrado; Matullo, Giuseppe; Dianzani, Irma

    2017-10-01

    Malignant pleural mesothelioma (MPM) is a rare, aggressive cancer caused by asbestos exposure. An inherited predisposition has been suggested to explain multiple cases in the same family and the observation that not all individuals highly exposed to asbestos develop the tumor. Germline mutations in BAP1 are responsible for a rare cancer predisposition syndrome that includes predisposition to mesothelioma. We hypothesized that other genes involved in hereditary cancer syndromes could be responsible for the inherited mesothelioma predisposition. We investigated the prevalence of germline variants in 94 cancer-predisposing genes in 93 MPM patients with a quantified asbestos exposure. Ten pathogenic truncating variants (PTVs) were identified in PALB2, BRCA1, FANCI, ATM, SLX4, BRCA2, FANCC, FANCF, PMS1 and XPC. All these genes are involved in DNA repair pathways, mostly in homologous recombination repair. Patients carrying PTVs represented 9.7% of the panel and showed lower asbestos exposure than did all the other patients (p = 0.0015). This suggests that they did not efficiently repair the DNA damage induced by asbestos and leading to carcinogenesis. This study shows that germline variants in several genes may increase MPM susceptibility in the presence of asbestos exposure and may be important for specific treatment. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  4. DNA damage and gene therapy of xeroderma pigmentosum, a human DNA repair-deficient disease.

    Science.gov (United States)

    Dupuy, Aurélie; Sarasin, Alain

    2015-06-01

    Xeroderma pigmentosum (XP) is a genetic disease characterized by hypersensitivity to ultra-violet and a very high risk of skin cancer induction on exposed body sites. This syndrome is caused by germinal mutations on nucleotide excision repair genes. No cure is available for these patients except a complete protection from all types of UV radiations. We reviewed the various techniques to complement or to correct the genetic defect in XP cells. We, particularly, developed the correction of XP-C skin cells using the fidelity of the homologous recombination pathway during repair of double-strand break (DSB) in the presence of XPC wild type sequences. We used engineered nucleases (meganuclease or TALE nuclease) to induce a DSB located at 90 bp of the mutation to be corrected. Expression of specific TALE nuclease in the presence of a repair matrix containing a long stretch of homologous wild type XPC sequences allowed us a successful gene correction of the original TG deletion found in numerous North African XP patients. Some engineered nucleases are sensitive to epigenetic modifications, such as cytosine methylation. In case of methylated sequences to be corrected, modified nucleases or demethylation of the whole genome should be envisaged. Overall, we showed that specifically-designed TALE-nuclease allowed us to correct a 2 bp deletion in the XPC gene leading to patient's cells proficient for DNA repair and showing normal UV-sensitivity. The corrected gene is still in the same position in the human genome and under the regulation of its physiological promoter. This result is a first step toward gene therapy in XP patients.

  5. Low intensity infrared laser affects expression of oxidative DNA repair genes in mitochondria and nucleus

    Science.gov (United States)

    Fonseca, A. S.; Magalhães, L. A. G.; Mencalha, A. L.; Geller, M.; Paoli, F.

    2014-11-01

    Practical properties and physical characteristics of low intensity lasers have made possible their application to treat soft tissue diseases. Excitation of intracellular chromophores by red and infrared radiation at low energy fluences with increase of mitochondrial metabolism is the basis of the biostimulation effect but free radicals can be produced. DNA lesions induced by free radicals are repaired by the base excision repair pathway. In this work, we evaluate the expression of POLγ and APEX2 genes related to repair of mitochondrial and nuclear DNA, respectively. Skin and muscle tissue of Wistar rats were exposed to low intensity infrared laser at different fluences. One hour and 24 hours after laser exposure, tissue samples were withdrawn for total RNA extraction, cDNA synthesis, and evaluation of POLγ and APEX2 mRNA expression by real time quantitative polymerase chain reaction. Skin and muscle tissue of Wistar rats exposed to laser radiation show different expression of POLγ and APEX2 mRNA depending of the fluence and time after exposure. Our study suggests that a low intensity infrared laser affects expression of genes involved in repair of oxidative lesions in mitochondrial and nuclear DNA.

  6. Both microsatellite length and sequence context determine frameshift mutation rates in defective DNA mismatch repair.

    Science.gov (United States)

    Chung, Heekyung; Lopez, Claudia G; Holmstrom, Joy; Young, Dennis J; Lai, Jenny F; Ream-Robinson, Deena; Carethers, John M

    2010-07-01

    It is generally accepted that longer microsatellites mutate more frequently in defective DNA mismatch repair (MMR) than shorter microsatellites. Indeed, we have previously observed that the A10 microsatellite of transforming growth factor beta type II receptor (TGFBR2) frameshifts -1 bp at a faster rate than the A8 microsatellite of activin type II receptor (ACVR2), although both genes become frameshift-mutated in >80% of MMR-defective colorectal cancers. To experimentally determine the effect of microsatellite length upon frameshift mutation in gene-specific sequence contexts, we altered the microsatellite length within TGFBR2 exon 3 and ACVR2 exon 10, generating A7, A10 and A13 constructs. These constructs were cloned 1 bp out of frame of EGFP, allowing a -1 bp frameshift to drive EGFP expression, and stably transfected into MMR-deficient cells. Subsequent non-fluorescent cells were sorted, cultured for 7-35 days and harvested for EGFP analysis and DNA sequencing. Longer microsatellites within TGFBR2 and ACVR2 showed significantly higher mutation rates than shorter ones, with TGFBR2 A13, A10 and A7 frameshifts measured at 22.38x10(-4), 2.17x10(-4) and 0.13x10(-4), respectively. Surprisingly, shorter ACVR2 constructs showed three times higher mutation rates at A7 and A10 lengths than identical length TGFBR2 constructs but comparably lower at the A13 length, suggesting influences from both microsatellite length as well as the sequence context. Furthermore, the TGFBR2 A13 construct mutated into 33% A11 sequences (-2 bp) in addition to expected A12 (-1 bp), indicating that this construct undergoes continual subsequent frameshift mutation. These data demonstrate experimentally that both the length of a mononucleotide microsatellite and its sequence context influence mutation rate in defective DNA MMR.

  7. Analysis of crossover breakpoints yields new insights into the nature of the gene conversion events associated with large NF1 deletions mediated by nonallelic homologous recombination.

    Science.gov (United States)

    Bengesser, Kathrin; Vogt, Julia; Mussotter, Tanja; Mautner, Victor-Felix; Messiaen, Ludwine; Cooper, David N; Kehrer-Sawatzki, Hildegard

    2014-02-01

    Large NF1 deletions are mediated by nonallelic homologous recombination (NAHR). An in-depth analysis of gene conversion operating in the breakpoint-flanking regions of large NF1 deletions was performed to investigate whether the rate of discontinuous gene conversion during NAHR with crossover is increased, as has been previously noted in NAHR-mediated rearrangements. All 20 germline type-1 NF1 deletions analyzed were mediated by NAHR associated with continuous gene conversion within the breakpoint-flanking regions. Continuous gene conversion was also observed in 31/32 type-2 NF1 deletions investigated. In contrast to the meiotic type-1 NF1 deletions, type-2 NF1 deletions are predominantly of post-zygotic origin. Our findings therefore imply that the mitotic as well as the meiotic NAHR intermediates of large NF1 deletions are processed by long-patch mismatch repair (MMR), thereby ensuring gene conversion tract continuity instead of the discontinuous gene conversion that is characteristic of short-patch repair. However, the single type-2 NF1 deletion not exhibiting continuous gene conversion was processed without MMR, yielding two different deletion-bearing chromosomes, which were distinguishable in terms of their breakpoint positions. Our findings indicate that MMR failure during NAHR, followed by post-meiotic/mitotic segregation, has the potential to give rise to somatic mosaicism in human genomic rearrangements by generating breakpoint heterogeneity.

  8. Rearrangement of Rag-1 recombinase gene in DNA-repair deficient/immunodeficient ``wasted`` mice

    Energy Technology Data Exchange (ETDEWEB)

    Woloschak, G.E.; Weaver, P.; Churchill, M.; Chang-Liu, C-M. [Argonne National Lab., IL (United States); Libertin, C.R. [Loyola Univ., Maywood, IL (United States)

    1992-11-01

    Mice recessive for the autosomal gene ``wasted`` (wst) display a disease pattern which includes increased sensitivity to the killing effects of ionizing radiation, immunodeficiency, and neurologic dysfunction. The recent cloning and characterization of recombinase genes (Rag-l/Rag-2) expressed in lymphoid and possibly central nervous system tissues prompted us to examine expression of these genes in DNA repair-deficient/immunodeficient wasted mice. Our results revealed that in thymus tissue, a small Rag-I transcript (1.0 kb) was detected in wst/wst mice that was not evident in thymus from control mice. In wst/{sm_bullet} mice, a two-fold increase in Rag-1 mRNA was evident in thymus tissue. Rag-2 mRNA could only be detected in thymus tissue from wst/{sm_bullet} and not from wst/wst or parental control BCF, mice. Southern blots revealed a rearrangement or deletion within the Rag-1 gene of affected wasted mice that was not evident in known strain-specific parental or littermate controls. These results support the idea that the Rag-1 gene may map at or near the locus for the wasted mutation. In addition, they suggest the importance of recombinase function in normal immune and central nervous system development as well as the potential contribution of this gene family to the normal repair of radiation-induced DNA damage.

  9. First report of a de novo germline mutation in the MLH1 gene

    Institute of Scientific and Technical Information of China (English)

    Rein P Stulp; Yvonne J Vos; Bart Mol; Arend Karrenbeld; Monique de Raad; Huub JC van der Mijle; Rolf H Sijmons

    2006-01-01

    Hereditary non-polyposis colorectal carcinoma (HNPCC)is an autosomal dominant disorder associated with colorectal and endometrial cancer and a range of other tumor types. Germline mutations in the DNA mismatch repair (MMR) genes, particularly MLH1, MSH2, and MSH6, underlie this disorder. The vast majority of these HNPCC-associated mutations have been proven,or assumed, given the family history of cancer, to be transmitted through several generations. To the best of our knowledge, only a single case of a de novo germline MMR gene mutation (in MSH2) has been reported till now. Here, we report a patient with a de novo mutation in MLH1. We identified a MLH1 Q701X truncating mutation in the blood lymphocytes of a male who had been diagnosed with rectal cancer at the age of 35. His family history of cancer was negative for the first- and second-degree relatives. The mutation could not be detected in the patient's parents and sibling and paternity was confirmed with a set of highly polymorphic markers. Non-penetrance and small family size is the common explanation of verified negative family histories of cancer in patients with a germline MMR gene mutation. However, in addition to some cases explained by non-paternity, de novo germline mutations should be considered as a possible explanation as well. As guidelines that stress not to restrict MMR gene mutation testing to patients with a positive family history are more widely introduced, more cases of de novo MMR gene germline mutations may be revealed.

  10. DNA repair gene ERCC2 polymorphisms and associations with breast and ovarian cancer risk

    Directory of Open Access Journals (Sweden)

    Rabiau Nadège

    2008-05-01

    Full Text Available Abstract Breast and ovarian cancers increased in the last decades. Except rare cases with a genetic predisposition and high penetrance, these pathologies are viewed as a polygenic disease. In this concept, association studies look for genetic variations such as polymorphisms in low penetrance genes, i.e. genes in interaction with environmental factors. DNA repair systems that protect the genome from deleterious endogenous and exogenous damages have been shown to have significantly reduced. In particular, enzymes of the nucleotide excision repair pathway are suspected to be implicated in cancer. In this study, 2 functional polymorphisms in a DNA repair gene ERCC2 were analyzed. The population included 911 breast cancer cases, 51 ovarian cancer cases and 1000 controls. The genotyping of 2 SNP (Single Nucleotide Polymorphism was carried out on the population with the MGB (Minor Groove Binder probe technique which consists of the use of the allelic discrimination with the Taqman® method. This study enabled us to show an increase in risk of breast cancer with no oral contraceptive users and with women exhibiting a waist-to-hip ratio (WHR > 0.85 for Asn homozygous for ERCC2 312.

  11. A comparison of synthetic oligodeoxynucleotides, DNA fragments and AAV-1 for targeted episomal and chromosomal gene repair

    Directory of Open Access Journals (Sweden)

    Leclerc Xavier

    2009-04-01

    Full Text Available Abstract Background Current strategies for gene therapy of inherited diseases consist in adding functional copies of the gene that is defective. An attractive alternative to these approaches would be to correct the endogenous mutated gene in the affected individual. This study presents a quantitative comparison of the repair efficiency using different forms of donor nucleic acids, including synthetic DNA oligonucleotides, double stranded DNA fragments with sizes ranging from 200 to 2200 bp and sequences carried by a recombinant adeno-associated virus (rAAV-1. Evaluation of each gene repair strategy was carried out using two different reporter systems, a mutated eGFP gene or a dual construct with a functional eGFP and an inactive luciferase gene, in several different cell systems. Gene targeting events were scored either following transient co-transfection of reporter plasmids and donor DNAs, or in a system where a reporter construct was stably integrated into the chromosome. Results In both episomal and chromosomal assays, DNA fragments were more efficient at gene repair than oligonucleotides or rAAV-1. Furthermore, the gene targeting frequency could be significantly increased by using DNA repair stimulating drugs such as doxorubicin and phleomycin. Conclusion Our results show that it is possible to obtain repair frequencies of 1% of the transfected cell population under optimized transfection protocols when cells were pretreated with phleomycin using rAAV-1 and dsDNA fragments.

  12. Assessment by Southern blot analysis of UV-induced damage and repair in human immunoglobulin genes.

    Science.gov (United States)

    Bianchi, M S; Bianchi, N O; de la Chapelle, A

    1990-09-01

    Irradiation of DNA with UV light induces pyrimidine dimers and (6-4) photoproducts. The presence of one of these photolesions in the restriction site of a given endonuclease inhibits DNA cleavage and induces the formation of fragments by incomplete DNA digestion which appear as additional, facultative bands in Southern hybridization autoradiograms. The number and size of these fragments show a positive correlation with the UV dose. The response to UV light of immunoglobulin light-chain constant kappa and heavy-chain constant mu genes was analyzed with 2 specific probes. Constant kappa and mu genes when irradiated as part of the chromatin of living lymphocytes showed a UV sensitivity similar to that of naked DNA. The same genes from granulocytes had 50-60 times lower UV sensitivity. When cells were allowed to repair photolesions for 24 h the facultative bands from granulocytes disappeared indicating that these cells were able to remove photolesions from constant kappa and mu genes. Facultative bands from lymphocytes showed a smaller decrease of density after 24 h repair. This suggests that lymphocytes are less efficient than granulocytes in removing UV damage from constant kappa and mu genes.

  13. Impact of DNA mismatch repair system alterations on human fertility and related treatments.

    Science.gov (United States)

    Hu, Min-hao; Liu, Shu-yuan; Wang, Ning; Wu, Yan; Jin, Fan

    2016-01-01

    DNA mismatch repair (MMR) is one of the biological pathways, which plays a critical role in DNA homeostasis, primarily by repairing base-pair mismatches and insertion/deletion loops that occur during DNA replication. MMR also takes part in other metabolic pathways and regulates cell cycle arrest. Defects in MMR are associated with genomic instability, predisposition to certain types of cancers and resistance to certain therapeutic drugs. Moreover, genetic and epigenetic alterations in the MMR system demonstrate a significant relationship with human fertility and related treatments, which helps us to understand the etiology and susceptibility of human infertility. Alterations in the MMR system may also influence the health of offspring conceived by assisted reproductive technology in humans. However, further studies are needed to explore the specific mechanisms by which the MMR system may affect human infertility. This review addresses the physiological mechanisms of the MMR system and associations between alterations of the MMR system and human fertility and related treatments, and potential effects on the next generation.

  14. Tissue repair genes: the TiRe database and its implication for skin wound healing.

    Science.gov (United States)

    Yanai, Hagai; Budovsky, Arie; Tacutu, Robi; Barzilay, Thomer; Abramovich, Amir; Ziesche, Rolf; Fraifeld, Vadim E

    2016-04-19

    Wound healing is an inherent feature of any multicellular organism and recent years have brought about a huge amount of data regarding regular and abnormal tissue repair. Despite the accumulated knowledge, modulation of wound healing is still a major biomedical challenge, especially in advanced ages. In order to collect and systematically organize what we know about the key players in wound healing, we created the TiRe (Tissue Repair) database, an online collection of genes and proteins that were shown to directly affect skin wound healing. To date, TiRe contains 397 entries for four organisms: Mus musculus, Rattus norvegicus, Sus domesticus, and Homo sapiens. Analysis of the TiRe dataset of skin wound healing-associated genes showed that skin wound healing genes are (i) over-conserved among vertebrates, but are under-conserved in invertebrates; (ii) enriched in extracellular and immuno-inflammatory genes; and display (iii) high interconnectivity and connectivity to other proteins. The latter may provide potential therapeutic targets. In addition, a slower or faster skin wound healing is indicative of an aging or longevity phenotype only when assessed in advanced ages, but not in the young. In the long run, we aim for TiRe to be a one-station resource that provides researchers and clinicians with the essential data needed for a better understanding of the mechanisms of wound healing, designing new experiments, and the development of new therapeutic strategies. TiRe is freely available online at http://www.tiredb.org.

  15. Reduced Activity of Double-Strand Break Repair Genes in Prostate Cancer Patients With Late Normal Tissue Radiation Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Oorschot, Bregje van, E-mail: b.vanoorschot@amc.uva.nl [Laboratory for Experimental Oncology and Radiobiology (LEXOR), Center for Molecular Medicine (CEMM), Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Hovingh, Suzanne E. [Laboratory for Experimental Oncology and Radiobiology (LEXOR), Center for Molecular Medicine (CEMM), Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Moerland, Perry D. [Bioinformatics Laboratory, Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Medema, Jan Paul; Stalpers, Lukas J.A. [Laboratory for Experimental Oncology and Radiobiology (LEXOR), Center for Molecular Medicine (CEMM), Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Vrieling, Harry [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands); Franken, Nicolaas A.P. [Laboratory for Experimental Oncology and Radiobiology (LEXOR), Center for Molecular Medicine (CEMM), Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands)

    2014-03-01

    Purpose: To investigate clinical parameters and DNA damage response as possible risk factors for radiation toxicity in the setting of prostate cancer. Methods and Materials: Clinical parameters of 61 prostate cancer patients, 34 with (overresponding, OR) and 27 without (non-responding, NR) severe late radiation toxicity were assembled. In addition, for a matched subset the DNA damage repair kinetics (γ-H2AX assay) and expression profiles of DNA repair genes were determined in ex vivo irradiated lymphocytes. Results: Examination of clinical data indicated none of the considered clinical parameters to be correlated with the susceptibility of patients to develop late radiation toxicity. Although frequencies of γ-H2AX foci induced immediately after irradiation were similar (P=.32), significantly higher numbers of γ-H2AX foci were found 24 hours after irradiation in OR compared with NR patients (P=.03). Patient-specific γ-H2AX foci decay ratios were significantly higher in NR patients than in OR patients (P<.0001). Consequently, NR patients seem to repair DNA double-strand breaks (DSBs) more efficiently than OR patients. Moreover, gene expression analysis indicated several genes of the homologous recombination pathway to be stronger induced in NR compared with OR patients (P<.05). A similar trend was observed in genes of the nonhomologous end-joining repair pathway (P=.09). This is congruent with more proficient repair of DNA DSBs in patients without late radiation toxicity. Conclusions: Both gene expression profiling and DNA DSB repair kinetics data imply that less-efficient repair of radiation-induced DSBs may contribute to the development of late normal tissue damage. Induction levels of DSB repair genes (eg, RAD51) may potentially be used to assess the risk for late radiation toxicity.

  16. Altered Gene Expressions and Cytogenetic Repair Efficiency in Cells with Suppressed Expression of XPA after Proton Exposure

    Science.gov (United States)

    Zhang, Ye; Rohde, Larry H.; Gridley, Daila S.; Mehta, Satish K.; Pierson, Duane L.; Wu, Honglu

    2009-01-01

    Cellular responses to damages from ionizing radiation (IR) exposure are influenced not only by the genes involved in DNA double strand break (DSB) repair, but also by non- DSB repair genes. We demonstrated previously that suppressed expression of several non-DSB repair genes, such as XPA, elevated IR-induced cytogenetic damages. In the present study, we exposed human fibroblasts that were treated with control or XPA targeting siRNA to 250 MeV protons (0 to 4 Gy), and analyzed chromosome aberrations and expressions of genes involved in DNA repair. As expected, after proton irradiation, cells with suppressed expression of XPA showed a significantly elevated frequency of chromosome aberrations compared with control siRNA treated (CS) cells. Protons caused more severe DNA damages in XPA knock-down cells, as 36% cells contained multiple aberrations compared to 25% in CS cells after 4Gy proton irradiation. Comparison of gene expressions using the real-time PCR array technique revealed that expressions of p53 and its regulated genes in irradiated XPA suppressed cells were altered similarly as in CS cells, suggesting that the impairment of IR induced DNA repair in XPA suppressed cells is p53-independent. Except for XPA, which was more than 2 fold down regulated in XPA suppressed cells, several other DNA damage sensing and repair genes (GTSE1, RBBP8, RAD51, UNG and XRCC2) were shown a more than 1.5 fold difference between XPA knock-down cells and CS cells after proton exposure. The possible involvement of these genes in the impairment of DNA repair in XPA suppressed cells will be further investigated.

  17. MMR vaccine in 14 months old children, intramuscular versus subcutaneous administration

    NARCIS (Netherlands)

    Lafeber AF; Klis FRM van der; Marzec AHJO; Labadie J; Ommen R van; Strieder TG; Berbers GAM; Utrecht Stichting Thuiszorg; Amersfoort Stichting Thuiszorg Eemland (STE),; LVO

    2001-01-01

    In this study we compared the recommended subcutaneous administration of the RIVM MMR vaccine with the intramuscular administration for both safety and immunogenicity. Study subjects were 14 months old children, living in Amersfoort or Utrecht, who were eligible for their first MMR vaccination. The

  18. No Effect of MMR Withdrawal on the Incidence of Autism: A Total Population Study

    Science.gov (United States)

    Honda, Hideo; Shimizu, Yasuo; Rutter, Michael

    2005-01-01

    Background: A causal relationship between the measles, mumps, and rubella (MMR) vaccine and occurrence of autism spectrum disorders (ASD) has been claimed, based on an increase in ASD in the USA and the UK after introduction of the MMR vaccine. However, the possibility that this increase is coincidental has not been eliminated. The unique…

  19. Role of Cell Cycle Regulation and MLH1, A Key DNA Mismatch Repair Protein, In Adaptive Survival Responses. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    David A. Boothman

    1999-08-11

    Due to several interesting findings on both adaptive survival responses (ASRs) and DNA mismatch repair (MMR), this grant was separated into two discrete Specific Aim sets (each with their own discrete hypotheses). The described experiments were simultaneously performed.

  20. Temozolomide Resistance in Glioblastoma Cell Lines: Implication of MGMT, MMR, P-Glycoprotein and CD133 Expression.

    Directory of Open Access Journals (Sweden)

    Gloria Perazzoli

    Full Text Available The use of temozolomide (TMZ has improved the prognosis for glioblastoma multiforme patients. However, TMZ resistance may be one of the main reasons why treatment fails. Although this resistance has frequently been linked to the expression of O6-methylguanine-DNA methyltransferase (MGMT it seems that this enzyme is not the only molecular mechanism that may account for the appearance of drug resistance in glioblastoma multiforme patients as the mismatch repair (MMR complex, P-glycoprotein, and/or the presence of cancer stem cells may also be implicated.Four nervous system tumor cell lines were used to analyze the modulation of MGMT expression and MGMT promoter methylation by TMZ treatment. Furthermore, 5-aza-2'-deoxycytidine was used to demethylate the MGMT promoter and O(6-benzylguanine to block GMT activity. In addition, MMR complex and P-glycoprotein expression were studied before and after TMZ exposure and correlated with MGMT expression. Finally, the effect of TMZ exposure on CD133 expression was analyzed.Our results showed two clearly differentiated groups of tumor cells characterized by low (A172 and LN229 and high (SF268 and SK-N-SH basal MGMT expression. Interestingly, cell lines with no MGMT expression and low TMZ IC50 showed a high MMR complex expression, whereas cell lines with high MGMT expression and high TMZ IC50 did not express the MMR complex. In addition, modulation of MGMT expression in A172 and LN229 cell lines was accompanied by a significant increase in the TMZ IC50, whereas no differences were observed in SF268 and SK-N-SH cell lines. In contrast, P-glycoprotein and CD133 was found to be unrelated to TMZ resistance in these cell lines.These results may be relevant in understanding the phenomenon of TMZ resistance, especially in glioblastoma multiforme patients laking MGMT expression, and may also aid in the design of new therapeutic strategies to improve the efficacy of TMZ in glioblastoma multiforme patients.

  1. Proteasome inhibition enhances resistance to DNA damage via upregulation of Rpn4-dependent DNA repair genes.

    Science.gov (United States)

    Karpov, Dmitry S; Spasskaya, Daria S; Tutyaeva, Vera V; Mironov, Alexander S; Karpov, Vadim L

    2013-09-17

    The 26S proteasome is an ATP-dependent multi-subunit protease complex and the major regulator of intracellular protein turnover and quality control. However, its role in the DNA damage response is controversial. We addressed this question in yeast by disrupting the transcriptional regulation of the PRE1 proteasomal gene. The mutant strain has decreased proteasome activity and is hyper-resistant to various DNA-damaging agents. We found that Rpn4-target genes MAG1, RAD23, and RAD52 are overexpressed in this strain due to Rpn4 stabilisation. These genes represent three different pathways of base excision, nucleotide excision and double strand break repair by homologous recombination (DSB-HR). Consistently, the proteasome mutant displays increased DSB-HR activity. Our data imply that the proteasome may have a negative role in DNA damage response.

  2. Mutation rates of TGFBR2 and ACVR2 coding microsatellites in human cells with defective DNA mismatch repair.

    Directory of Open Access Journals (Sweden)

    Heekyung Chung

    Full Text Available Microsatellite instability promotes colonic tumorigenesis through generating frameshift mutations at coding microsatellites of tumor suppressor genes, such as TGFBR2 and ACVR2. As a consequence, signaling through these TGFbeta family receptors is abrogated in DNA Mismatch repair (MMR-deficient tumors. How these mutations occur in real time and mutational rates of these human coding sequences have not previously been studied. We utilized cell lines with different MMR deficiencies (hMLH1-/-, hMSH6-/-, hMSH3-/-, and MMR-proficient to determine mutation rates. Plasmids were constructed in which exon 3 of TGFBR2 and exon 10 of ACVR2 were cloned +1 bp out of frame, immediately after the translation initiation codon of an enhanced GFP (EGFP gene, allowing a -1 bp frameshift mutation to drive EGFP expression. Mutation-resistant plasmids were constructed by interrupting the coding microsatellite sequences, preventing frameshift mutation. Stable cell lines were established containing portions of TGFBR2 and ACVR2, and nonfluorescent cells were sorted, cultured for 7-35 days, and harvested for flow cytometric mutation detection and DNA sequencing at specific time points. DNA sequencing revealed a -1 bp frameshift mutation (A9 in TGFBR2 and A7 in ACVR2 in the fluorescent cells. Two distinct fluorescent populations, M1 (dim, representing heteroduplexes and M2 (bright, representing full mutants were identified, with the M2 fraction accumulating over time. hMLH1 deficiency revealed 11 (5.91 x 10(-4 and 15 (2.18 x 10(-4 times higher mutation rates for the TGFBR2 and ACVR2 microsatellites compared to hMSH6 deficiency, respectively. The mutation rate of the TGFBR2 microsatellite was approximately 3 times higher in both hMLH1 and hMSH6 deficiencies than the ACVR2 microsatellite. The -1 bp frameshift mutation rates of TGFBR2 and ACVR2 microsatellite sequences are dependent upon the human MMR background.

  3. Rapid assessment of repair of ultraviolet DNA damage with a modified host-cell reactivation assay using a luciferase reporter gene and correlation with polymorphisms of DNA repair genes in normal human lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Qiao Yawei; Spitz, Margaret R.; Guo Zhaozheng; Hadeyati, Mohammad; Grossman, Lawrence; Kraemer, Kenneth H.; Wei Qingyi

    2002-11-30

    As DNA repair plays an important role in genetic susceptibility to cancer, assessment of the DNA repair phenotype is critical for molecular epidemiological studies of cancer. In this report, we compared use of the luciferase (luc) reporter gene in a host-cell reactivation (HCR) (LUC) assay of repair of ultraviolet (UV) damage to DNA to use of the chloramphenicol (cat) gene-based HCR (CAT) assay we used previously for case-control studies. We performed both the assays on cryopreserved lymphocytes from 102 healthy non-Hispanic white subjects. There was a close correlation between DNA repair capacity (DRC) as measured by the LUC and CAT assays. Although these two assays had similar variation, the LUC assay was faster and more sensitive. We also analyzed the relationship between DRC and the subjects' previously determined genotypes for four polymorphisms of two nucleotide-excision repair (NER) genes (in intron 9 of xeroderma pigmentosum (XP) C and exons 6, 10 and 23 of XPD) and one polymorphism of a base-excision repair gene in exon 10 of X-ray complementing group 1 (XRCC1). The DRC was significantly lower in subjects homozygous for one or more polymorphisms of the two NER genes than in subjects with other genotypes (P=0.010). In contrast, the polymorphic XRCC1 allele had no significant effect on DRC. These results suggest that the post-UV LUC assay measures NER phenotype and that polymorphisms of XPC and XPD genes modulate DRC. For population studies of the DNA repair phenotype, many samples need to be evaluated, and so the LUC assay has several advantages over the CAT assay: the LUC assay was more sensitive, had less variation, was not radioactive, was easier to perform, and required fewer cryopreserved cells. These features make the LUC-based HCR assay suitable for molecular epidemiological studies.

  4. Mathematical model of MMR inversion for geophysical data

    Directory of Open Access Journals (Sweden)

    Suabsagun Yooyuanyong

    2007-09-01

    Full Text Available In this paper, we present an analysis of the solution to a number of geophysical inverse problems which are generally non-unique. The mathematical inverse problem that arises is commonly ill-posed in the sense that small changes in the data lead to large changes in the solution. We conduct the inversion algorithm to explore the conductivity for the ground structure. The algorithm uses the data in the form of magnetic field measurements for magnetometric resistivity (MMR. The inversion example is performed to investigate the conductivity ground profile that best fits the observed data. The result is compared with the true model and discussed to show the efficiency of the method. The model for the inversion example with the apparent conductivity and the true conductivity are plotted to show the convergence of the algorithm.

  5. Rearrangement of RAG-1 recombinase gene in DNA-repair deficient ``wasted`` mice

    Energy Technology Data Exchange (ETDEWEB)

    Woloschak, G.E.; Libertin, C.R.; Weaver, P. [Loyola Univ., Chicago, IL (United States); Churchill, M.; Chang-Liu, C.M. [Argonne National Lab., IL (United States)

    1993-11-01

    Mice recessive for the autosomal gene ``wasted`` wst display a disease pattern which includes increased sensitivity to the killing effects of ionizing radiation, immunodeficiency, and neurologic dysfunction. The recent cloning and characterization of recombinase genes (RAG-l/RAG-2) expressed in lymphoid and possibly central nervous system tissues prompted us to examine expression of these genes in DNA repair-deficient/immunodeficient wasted mice. Our results revealed expression of RAG-1 mRNA in spinal cord (but not brain) of control mice; no expression of RAG-1 mRNA was detected in spinal cord or brain from wst/wst mice or their normal littermates (wst/{center_dot}mice). In thymus tissue, a small RAG-1 transcript (1.0 kb) was detected in wst/wst mice that was not evident in thymus from control mice. In wst/{center_dot}mice, a two-fold increase in RAG-1 mRNA was evident in thymus tissue. RAG-2 mRNA could only be detected in thymus tissue from wst/{center_dot} and not from wst/wst or parental control BCF{sub 1} mice. Southern blots revealed a rearrangement/deletion within the RAG-1 gene of affected wasted mice, not evident in known strain-specific parental or littermate controls. These results support the idea that the RAG-1 gene may map at or near the locus for the wasted mutation. In addition, they suggest the importance of recombinase function in normal immune and central nervous system development as well as the potential contribution of this gene family to the normal repair of radiation-induced DNA damage.

  6. Paradoxical DNA repair and peroxide resistance gene conservation in Bacillus pumilus SAFR-032.

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    Jason Gioia

    Full Text Available BACKGROUND: Bacillus spores are notoriously resistant to unfavorable conditions such as UV radiation, gamma-radiation, H2O2, desiccation, chemical disinfection, or starvation. Bacillus pumilus SAFR-032 survives standard decontamination procedures of the Jet Propulsion Lab spacecraft assembly facility, and both spores and vegetative cells of this strain exhibit elevated resistance to UV radiation and H2O2 compared to other Bacillus species. PRINCIPAL FINDINGS: The genome of B. pumilus SAFR-032 was sequenced and annotated. Lists of genes relevant to DNA repair and the oxidative stress response were generated and compared to B. subtilis and B. licheniformis. Differences in conservation of genes, gene order, and protein sequences are highlighted because they potentially explain the extreme resistance phenotype of B. pumilus. The B. pumilus genome includes genes not found in B. subtilis or B. licheniformis and conserved genes with sequence divergence, but paradoxically lacks several genes that function in UV or H2O2 resistance in other Bacillus species. SIGNIFICANCE: This study identifies several candidate genes for further research into UV and H2O2 resistance. These findings will help explain the resistance of B. pumilus and are applicable to understanding sterilization survival strategies of microbes.

  7. Selenium compounds activate ATM-dependent DNA damage responses via the mismatch repair protein hMLH1 in colorectal cancer cells

    Science.gov (United States)

    Epidemiological and animal studies indicate that selenium supplementation suppresses risk of colorectal and other cancers. The majority of colorectal cancers are characterized by a defective DNA mismatch repair (MMR) process. Here, we have employed the MMR-deficient HCT 116 colorectal cancer cells ...

  8. The democratization of gene editing: Insights from site-specific cleavage and double-strand break repair.

    Science.gov (United States)

    Jasin, Maria; Haber, James E

    2016-08-01

    DNA double-strand breaks (DSBs) are dangerous lesions that if not properly repaired can lead to genomic change or cell death. Organisms have developed several pathways and have many factors devoted to repairing DSBs, which broadly occurs by homologous recombination, which relies on an identical or homologous sequence to template repair, or nonhomologous end-joining. Much of our understanding of these repair mechanisms has come from the study of induced DNA cleavage by site-specific endonucleases. In addition to their biological role, these cellular pathways can be co-opted for gene editing to study gene function or for gene therapy or other applications. While the first gene editing experiments were done more than 20 years ago, the recent discovery of RNA-guided endonucleases has simplified approaches developed over the years to make gene editing an approach that is available to the entire biomedical research community. Here, we review DSB repair mechanisms and site-specific cleavage systems that have provided insight into these mechanisms and led to the current gene editing revolution.

  9. Specific targeted gene repair using single-stranded DNA oligonucleotides at an endogenous locus in mammalian cells uses homologous recombination.

    Science.gov (United States)

    McLachlan, Jennifer; Fernandez, Serena; Helleday, Thomas; Bryant, Helen E

    2009-12-03

    The feasibility of introducing point mutations in vivo using single-stranded DNA oligonucleotides (ssON) has been demonstrated but the efficiency and mechanism remain elusive and potential side effects have not been fully evaluated. Understanding the mechanism behind this potential therapy may help its development. Here, we demonstrate the specific repair of an endogenous non-functional hprt gene by a ssON in mammalian cells, and show that the frequency of such an event is enhanced when cells are in S-phase of the cell cycle. A potential barrier in using ssONs as gene therapy could be non-targeted mutations or gene rearrangements triggered by the ssON. Both the non-specific mutation frequencies and the frequency of gene rearrangements were largely unaffected by ssONs. Furthermore, we find that the introduction of a mutation causing the loss of a functional endogenous hprt gene by a ssON occurred at a similarly low but statistically significant frequency in wild type cells and in cells deficient in single strand break repair, nucleotide excision repair and mismatch repair. However, this mutation was not induced in XRCC3 mutant cells deficient in homologous recombination. Thus, our data suggest ssON-mediated targeted gene repair is more efficient in S-phase and involves homologous recombination.

  10. Expression of DNA repair genes in burned skin exposed to low-level red laser.

    Science.gov (United States)

    Trajano, Eduardo Tavares Lima; Mencalha, Andre Luiz; Monte-Alto-Costa, Andréa; Pôrto, Luís Cristóvão; de Souza da Fonseca, Adenilson

    2014-11-01

    Although red laser lights lie in the region of non-ionizing radiations in the electromagnetic spectrum, there are doubts whether absorption of these radiations causes lesions in the DNA molecule. Our aim was to investigate the expression of the genes involved with base excision and nucleotide excision repair pathways in skin tissue submitted to burn injury and exposed to low-level red laser. Wistar rats were divided as follows: control group-rats burned and not irradiated, laser group-rats burned and irradiated 1 day after injury for five consecutive days, and later laser group-rats injured and treated 4 days after injury for five consecutive days. Irradiation was performed according to a clinical protocol (20 J/cm(2), 100 mW, continuous wave emission mode). The animals were sacrificed on day 10, and scarred tissue samples were withdrawn for total RNA extraction, complementary DNA (cDNA) synthesis, and evaluation of gene expression by quantitative polymerase chain reaction. Low-level red laser exposure (1) reduces the expression of APE1 messenger (mRNA), (2) increases the expression of OGG1 mRNA, (3) reduces the expression of XPC mRNA, and (4) increases the expression of XPA mRNA both in laser and later laser groups. Red laser exposure at therapeutic fluences alters the expression of genes related to base excision and nucleotide excision pathways of DNA repair during wound healing of burned skin.

  11. Are SNP-Smoking Association Studies Needed in Controls? DNA Repair Gene Polymorphisms and Smoking Intensity.

    Science.gov (United States)

    Verde, Zoraida; Reinoso, Luis; Chicharro, Luis Miguel; Resano, Pilar; Sánchez-Hernández, Ignacio; Rodríguez González-Moro, Jose Miguel; Bandrés, Fernando; Gómez-Gallego, Félix; Santiago, Catalina

    2015-01-01

    Variations in tobacco-related cancers, incidence and prevalence reflect differences in tobacco consumption in addition to genetic factors. Besides, genes related to lung cancer risk could be related to smoking behavior. Polymorphisms altering DNA repair capacity may lead to synergistic effects with tobacco carcinogen-induced lung cancer risk. Common problems in genetic association studies, such as presence of gene-by-environment (G x E) correlation in the population, may reduce the validity of these designs. The main purpose of this study was to evaluate the independence assumption for selected SNPs and smoking behaviour in a cohort of 320 healthy Spanish smokers. We found an association between the wild type alleles of XRCC3 Thr241Met or KLC3 Lys751Gln and greater smoking intensity (OR = 12.98, 95% CI = 2.86-58.82 and OR=16.90, 95% CI=2.09-142.8; respectively). Although preliminary, the results of our study provide evidence that genetic variations in DNA-repair genes may influence both smoking habits and the development of lung cancer. Population-specific G x E studies should be carried out when genetic and environmental factors interact to cause the disease.

  12. Are SNP-Smoking Association Studies Needed in Controls? DNA Repair Gene Polymorphisms and Smoking Intensity.

    Directory of Open Access Journals (Sweden)

    Zoraida Verde

    Full Text Available Variations in tobacco-related cancers, incidence and prevalence reflect differences in tobacco consumption in addition to genetic factors. Besides, genes related to lung cancer risk could be related to smoking behavior. Polymorphisms altering DNA repair capacity may lead to synergistic effects with tobacco carcinogen-induced lung cancer risk. Common problems in genetic association studies, such as presence of gene-by-environment (G x E correlation in the population, may reduce the validity of these designs. The main purpose of this study was to evaluate the independence assumption for selected SNPs and smoking behaviour in a cohort of 320 healthy Spanish smokers. We found an association between the wild type alleles of XRCC3 Thr241Met or KLC3 Lys751Gln and greater smoking intensity (OR = 12.98, 95% CI = 2.86-58.82 and OR=16.90, 95% CI=2.09-142.8; respectively. Although preliminary, the results of our study provide evidence that genetic variations in DNA-repair genes may influence both smoking habits and the development of lung cancer. Population-specific G x E studies should be carried out when genetic and environmental factors interact to cause the disease.

  13. A systematic gene-gene and gene-environment interaction analysis of DNA repair genes XRCC1, XRCC2, XRCC3, XRCC4, and oral cancer risk.

    Science.gov (United States)

    Yang, Cheng-Hong; Lin, Yu-Da; Yen, Ching-Yui; Chuang, Li-Yeh; Chang, Hsueh-Wei

    2015-04-01

    Oral cancer is the sixth most common cancer worldwide with a high mortality rate. Biomarkers that anticipate susceptibility, prognosis, or response to treatments are much needed. Oral cancer is a polygenic disease involving complex interactions among genetic and environmental factors, which require multifaceted analyses. Here, we examined in a dataset of 103 oral cancer cases and 98 controls from Taiwan the association between oral cancer risk and the DNA repair genes X-ray repair cross-complementing group (XRCCs) 1-4, and the environmental factors of smoking, alcohol drinking, and betel quid (BQ) chewing. We employed logistic regression, multifactor dimensionality reduction (MDR), and hierarchical interaction graphs for analyzing gene-gene (G×G) and gene-environment (G×E) interactions. We identified a significantly elevated risk of the XRCC2 rs2040639 heterozygous variant among smokers [adjusted odds ratio (OR) 3.7, 95% confidence interval (CI)=1.1-12.1] and alcohol drinkers [adjusted OR=5.7, 95% CI=1.4-23.2]. The best two-factor based G×G interaction of oral cancer included the XRCC1 rs1799782 and XRCC2 rs2040639 [OR=3.13, 95% CI=1.66-6.13]. For the G×E interaction, the estimated OR of oral cancer for two (drinking-BQ chewing), three (XRCC1-XRCC2-BQ chewing), four (XRCC1-XRCC2-age-BQ chewing), and five factors (XRCC1-XRCC2-age-drinking-BQ chewing) were 32.9 [95% CI=14.1-76.9], 31.0 [95% CI=14.0-64.7], 49.8 [95% CI=21.0-117.7] and 82.9 [95% CI=31.0-221.5], respectively. Taken together, the genotypes of XRCC1 rs1799782 and XRCC2 rs2040639 DNA repair genes appear to be significantly associated with oral cancer. These were enhanced by exposure to certain environmental factors. The observations presented here warrant further research in larger study samples to examine their relevance for routine clinical care in oncology.

  14. Dietary Berries and Ellagic Acid Prevent Oxidative DNA Damage and Modulate Expression of DNA Repair Genes

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    Ramesh C. Gupta

    2008-03-01

    Full Text Available DNA damage is a pre-requisite for the initiation of cancer and agents that reduce this damage are useful in cancer prevention. In this study, we evaluated the ability of whole berries and berry phytochemical, ellagic acid to reduce endogenous oxidative DNA damage. Ellagic acid was selected based on > 95% inhibition of 8-oxodeoxyguosine (8-oxodG and other unidentified oxidative DNA adducts induced by 4-hydroxy-17B;-estradiol and CuCl2 in vitro. Inhibition of the latter occurred at lower concentrations (10 u(microM than that for 8-oxodG (100 u(microM. In the in vivo study, female CD-1 mice (n=6 were fed either a control diet or diet supplemented with ellagic acid (400 ppm and dehydrated berries (5% w/w with varying ellagic acid contents -- blueberry (low, strawberry (medium and red raspberry (high, for 3 weeks. Blueberry and strawberry diets showed moderate reductions in endogenous DNA adducts (25%. However, both red raspberry and ellagic acid diets showed a significant reduction of 59% (p < 0.001 and 48% (p < 0.01, respectively. Both diets also resulted in a 3-8 fold over-expression of genes involved in DNA repair such as xeroderma pigmentosum group A complementing protein (XPA, DNA excision repair protein (ERCC5 and DNA ligase III (DNL3. These results suggest that red raspberry and ellagic acid reduce endogenous oxidative DNA damage by mechanisms which may involve increase in DNA repair.

  15. Nucleotide Excision Repair in Cellular Chromatin: Studies with Yeast from Nucleotide to Gene to Genome

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    Simon Reed

    2012-09-01

    Full Text Available Here we review our development of, and results with, high resolution studies on global genome nucleotide excision repair (GGNER in Saccharomyces cerevisiae. We have focused on how GGNER relates to histone acetylation for its functioning and we have identified the histone acetyl tranferase Gcn5 and acetylation at lysines 9/14 of histone H3 as a major factor in enabling efficient repair. We consider results employing primarily MFA2 as a model gene, but also those with URA3 located at subtelomeric sequences. In the latter case we also see a role for acetylation at histone H4. We then go on to outline the development of a high resolution genome-wide approach that enables one to examine correlations between histone modifications and the nucleotide excision repair (NER of UV-induced cyclobutane pyrimidine dimers throughout entire genomes. This is an approach that will enable rapid advances in understanding the complexities of how compacted chromatin in chromosomes is processed to access DNA damage and then returned to its pre-damaged status to maintain epigenetic codes.

  16. Polymorphisms in nucleotide excision repair genes, smoking and intake of fruit and vegetables in relation to lung cancer

    DEFF Research Database (Denmark)

    Raaschou-Nielsen, Ole; Sørensen, Mette; Overvad, Kim

    2007-01-01

    Polymorphisms in nucleotide excision repair genes have been associated with risk for lung cancer. We examined gene-environment interactions in relation to lung cancer in 430 cases and 790 comparison persons identified within a prospective cohort of 57,053 persons. We included polymorphisms...... in the XPC, XPA and XPD genes involved in the nucleotide excision DNA repair pathway and analysed possible interactions with smoking and dietary intake of fruit and vegetables in relation to risk for lung cancer. We found that intake of fruit was associated with lower risk for lung cancer only among carriers...

  17. A non-canonical mismatch repair pathway in prokaryotes

    Science.gov (United States)

    Castañeda-García, A.; Prieto, A. I.; Rodríguez-Beltrán, J.; Alonso, N.; Cantillon, D.; Costas, C.; Pérez-Lago, L.; Zegeye, E. D.; Herranz, M.; Plociński, P.; Tonjum, T.; García de Viedma, D.; Paget, M.; Waddell, S. J.; Rojas, A. M.; Doherty, A. J.; Blázquez, J.

    2017-01-01

    Mismatch repair (MMR) is a near ubiquitous pathway, essential for the maintenance of genome stability. Members of the MutS and MutL protein families perform key steps in mismatch correction. Despite the major importance of this repair pathway, MutS–MutL are absent in almost all Actinobacteria and many Archaea. However, these organisms exhibit rates and spectra of spontaneous mutations similar to MMR-bearing species, suggesting the existence of an alternative to the canonical MutS–MutL-based MMR. Here we report that Mycobacterium smegmatis NucS/EndoMS, a putative endonuclease with no structural homology to known MMR factors, is required for mutation avoidance and anti-recombination, hallmarks of the canonical MMR. Furthermore, phenotypic analysis of naturally occurring polymorphic NucS in a M. smegmatis surrogate model, suggests the existence of M. tuberculosis mutator strains. The phylogenetic analysis of NucS indicates a complex evolutionary process leading to a disperse distribution pattern in prokaryotes. Together, these findings indicate that distinct pathways for MMR have evolved at least twice in nature. PMID:28128207

  18. Early passage bone marrow stromal cells express genes involved in nervous system development supporting their relevance for neural repair

    NARCIS (Netherlands)

    Nandoe, R.D.S.; Bossers, K.; Ritfeld, G.J.; Blits, B.; Grotenhuis, J.A.; Verhaagen, J.; Oudega, M.

    2011-01-01

    PURPOSE: The assessment of the capacity of bone marrow stromal cells (BMSC) to repair the nervous system using gene expression profiling. The evaluation of effects of long-term culturing on the gene expression profile of BMSC. METHODS: Fourty four k whole genome rat microarrays were used to study

  19. Synergistic interactions between RAD5, RAD16, and RAD54, three partially homologous yeast DNA repair genes each in a different repair pathway

    Energy Technology Data Exchange (ETDEWEB)

    Glassner, B.J. [Univ. of California, Berkeley, CA (United States); Mortimer, R.K. [Univ. of California, Berkeley, CA (United States)]|[Lawrence Berkeley Laboratory, Berkeley, CA (United States)

    1994-07-01

    Considerable homology has recently been noted between the proteins encoded by the RAD5, RAD16 and RAD54 genes of Saccharomyces cerevisiae. These genes are members of the RAD6, RAD3 and RAD50 epistasis groups, respectively, which correspond to the three major DNA repair pathways in yeast. These proteins also share homology with other eucaryotic proteins, including those encoded by SNF2 and MO1 of yeast, brahma and lodestar of Drosophila and the human ERCC6 gene. The homology shares features with known helicases, suggesting a newly identified helicase subfamily. We have constructed a series of congenic single-, double- and triple-deletion mutants involving RAD5, RAD16 and RAD54 to examine the interactions between these genes. Each deletion mutation alone has only a moderate effect on survival after exposure to UV radiation. Each pairwise-double mutant exhibits marked synergism. The triple-deletion mutant displays further synergism. These results confirm the assignment of the RAD54 gene to the RAD50 epistasis group and suggest that the RAD16 gene plays a larger role in DNA repair after exposure to UV radiation than has been suggested previously. Additionally, the proteins encoded by RAD5, RAD16, and RAD54 may compete for the same substrate after damage induced by UV radiation, possibly at an early step in their respective pathways. 49 refs., 6 figs., 2 tabs.

  20. Haplotype analyses of DNA repair gene polymorphisms and their role in ulcerative colitis.

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    Avinash Bardia

    Full Text Available Ulcerative colitis (UC is a major clinical form of inflammatory bowel disease. UC is characterized by mucosal inflammation limited to the colon, always involving the rectum and a variable extent of the more proximal colon in a continuous manner. Genetic variations in DNA repair genes may influence the extent of repair functions, DNA damage, and thus the manifestations of UC. This study thus evaluated the role of polymorphisms of the genes involved in DNA repair mechanisms. A total of 171 patients and 213 controls were included. Genotyping was carried out by ARMS PCR and PCR-RFLP analyses for RAD51, XRCC3 and hMSH2 gene polymorphisms. Allelic and genotypic frequencies were computed in both control & patient groups and data was analyzed using appropriate statistical tests. The frequency of 'A' allele of hMSH2 in the UC group caused statistically significant increased risk for UC compared to controls (OR 1.64, 95% CI 1.16-2.31, p = 0.004. Similarly, the CT genotype of XRCC3 gene was predominant in the UC group and increased the risk for UC by 1.75 fold compared to controls (OR 1.75, 95% CI 1.15-2.67, p = 0.03, further confirming the risk of 'T' allele in UC. The GC genotype frequency of RAD51 gene was significantly increased (p = 0.02 in the UC group (50.3% compared to controls (38%. The GC genotype significantly increased the risk for UC compared to GG genotype by 1.73 fold (OR 1.73, 95% CI 1.14-2.62, p = 0.02 confirming the strong association of 'C' allele with UC. Among the controls, the SNP loci combination of hMSH2:XRCC3 were in perfect linkage. The GTC and ACC haplotypes were found to be predominant in UC than controls with a 2.28 and 2.93 fold significant increase risk of UC.

  1. Polymorphisms in genes controlling inflammation and tissue repair in rheumatoid arthritis: a case control study

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    de Vogel Lisette

    2011-03-01

    Full Text Available Abstract Background Various cytokines and inflammatory mediators are known to be involved in the pathogenesis of rheumatoid arthritis (RA. We hypothesized that polymorphisms in selected inflammatory response and tissue repair genes contribute to the susceptibility to and severity of RA. Methods Polymorphisms in TNFA, IL1B, IL4, IL6, IL8, IL10, PAI1, NOS2a, C1INH, PARP, TLR2 and TLR4 were genotyped in 376 Caucasian RA patients and 463 healthy Caucasian controls using single base extension. Genotype distributions in patients were compared with those in controls. In addition, the association of polymorphisms with the need for anti-TNF-α treatment as a marker of RA severity was assessed. Results The IL8 781 CC genotype was associated with early onset of disease. The TNFA -238 G/A polymorphism was differentially distributed between RA patients and controls, but only when not corrected for age and gender. None of the polymorphisms was associated with disease severity. Conclusions We here report an association between IL8 781 C/T polymorphism and age of onset of RA. Our findings indicate that there might be a role for variations in genes involved in the immune response and in tissue repair in RA pathogenesis. Nevertheless, additional larger genomic and functional studies are required to further define their role in RA.

  2. Repair of spinal cord injury by neural stem cells modified with BDNF gene in rats

    Institute of Scientific and Technical Information of China (English)

    Wei LI; Wen-Qin CAI; Cheng-Ren LI

    2006-01-01

    Objective To explore repair of spinal cord injury by neural stem cells (NSCs) modified with brain derived neurotrophic factor (BDNF) gene (BDNF-NSCs) in rats. Methods Neural stem cells modified with BDNF gene were transplanted into the complete transection site of spinal cord at the lumbar 4 (L4) level in rats. Motor function of rats'hind limbs was observed and HE and X-gal immunocytochemical staining, in situ hybridization, and retrograde HRP tracing were also performed. Results BDNF-NSCs survived and integrated well with host spinal cord. In the transplant group, some X-gal positive, NF-200 positive, GFAP positive, BDNF positive, and BDNF mRNA positive cells, and many NF-200 positive nerve fibers were observed in the injury site. Retrograde HRP tracing through sciatic nerve showed some HRP positive cells and nerve fibers near the rostral side of the injury one month after transplant and with time, they increased in number. Examinations on rats' motor function and behavior demonstrated that motor function of rats' hind limbs improved better in the transplant group than the injury group. Conclusion BDNF-NSCs can survive, differentiate,and partially integrate with host spinal cord, and they significantly ameliorate rats ' motor function of hind limbs, indicating their promising role in repairing spinal cord injury.

  3. Repairing DNA damage in xeroderma pigmentosum: T4N5 lotion and gene therapy.

    Science.gov (United States)

    Zahid, Sarwar; Brownell, Isaac

    2008-04-01

    Patients with xeroderma pigmentosum (XP) have defective DNA repair and are at a high risk for cutaneous malignancies. Standard treatments for XP are limited in scope and effectiveness. Understanding the molecular etiology of XP has led to the development of novel therapeutic approaches, including enzyme and gene therapies. One new topical treatment utilizing bacteriophage T4 endonuclease 5 (T4N5) in a liposomal lotion is currently in clinical trials and has received a Fast Track designation from the FDA. Gene therapy for XP, while making leaps in preclinical studies, has been slower to develop due to tactical hurdles, but seems to have much potential for future treatment. If these treatments prove effective in lowering the risk of cancer in patients with XP, they may also be found useful in reducing skin cancers in other at-risk patient populations.

  4. Novel Mutations in MLH1 and MSH2 Genes in Mexican Patients with Lynch Syndrome

    Science.gov (United States)

    Moreno-Ortiz, Jose Miguel; Ayala-Madrigal, María de la Luz; Corona-Rivera, Jorge Román; Maciel-Gutiérrez, Víctor; Franco-Topete, Ramón Antonio; Armendáriz-Borunda, Juan; Pérez-Carbonell, Lucia; Rhees, Jennifer; Gutiérrez-Angulo, Melva

    2016-01-01

    Background. Lynch Syndrome (LS) is characterized by germline mutations in the DNA mismatch repair (MMR) genes MLH1, MSH2, MSH6, and PMS2. This syndrome is inherited in an autosomal dominant pattern and is characterized by early onset colorectal cancer (CRC) and extracolonic tumors. The aim of this study was to identify mutations in MMR genes in three Mexican patients with LS. Methods. Immunohistochemical analysis was performed as a prescreening method to identify absent protein expression. PCR, Denaturing High Performance Liquid Chromatography (dHPLC), and Sanger sequencing complemented the analysis. Results. Two samples showed the absence of nuclear staining for MLH1 and one sample showed loss of nuclear staining for MSH2. The mutations found in MLH1 gene were c.2103+1G>C in intron 18 and compound heterozygous mutants c.1852_1854delAAG (p.K618del) and c.1852_1853delinsGC (p.K618A) in exon 16. In the MSH2 gene, we identified mutation c.638dupT (p.L213fs) in exon 3. Conclusions. This is the first report of mutations in MMR genes in Mexican patients with LS and these appear to be novel. PMID:27247567

  5. Novel Mutations in MLH1 and MSH2 Genes in Mexican Patients with Lynch Syndrome

    Directory of Open Access Journals (Sweden)

    Jose Miguel Moreno-Ortiz

    2016-01-01

    Full Text Available Background. Lynch Syndrome (LS is characterized by germline mutations in the DNA mismatch repair (MMR genes MLH1, MSH2, MSH6, and PMS2. This syndrome is inherited in an autosomal dominant pattern and is characterized by early onset colorectal cancer (CRC and extracolonic tumors. The aim of this study was to identify mutations in MMR genes in three Mexican patients with LS. Methods. Immunohistochemical analysis was performed as a prescreening method to identify absent protein expression. PCR, Denaturing High Performance Liquid Chromatography (dHPLC, and Sanger sequencing complemented the analysis. Results. Two samples showed the absence of nuclear staining for MLH1 and one sample showed loss of nuclear staining for MSH2. The mutations found in MLH1 gene were c.2103+1G>C in intron 18 and compound heterozygous mutants c.1852_1854delAAG (p.K618del and c.1852_1853delinsGC (p.K618A in exon 16. In the MSH2 gene, we identified mutation c.638dupT (p.L213fs in exon 3. Conclusions. This is the first report of mutations in MMR genes in Mexican patients with LS and these appear to be novel.

  6. Low vaccine efficacy of mumps component among MMR vaccine recipients in Chennai, India

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    Jeevan Malaiyan

    2014-01-01

    Full Text Available Introduction of MMR vaccine was believed to have resulted in a decline in the incidence of measles, mumps and rubella infections. However, recent reports suggest the re-emergence of mumps infection worldwide in the vaccinated populations. It was proposed that the reason for this re-emergence was poor efficacy of MMR vaccine. The present study was aimed to investigate mumps infection in MMR vaccinated and non-vaccinated populations in Chennai, India. Blood samples were collected from acute mumps cases (n=74, 42<12 yr age, 54% males and investigated for IgM antibody against mumps, IgG antibody against measles, mumps and rubella viruses by ELISA. Sixty seven (91% patients had received MMR vaccine. All the 67 vaccinated cases were positive for parotitis, and mumps IgM. However, only 10 (15% were positive for IgG. All samples (100% were positive for rubella and measles IgG. These findings showed the occurrence of mumps infection among MMR vaccinated individuals in Chennai, India. The MMR vaccine failed to generate anti-mumps IgG. The reason may be low vaccine efficacy of the mumps component of the MMR vaccine used.

  7. Mutation screening of mismatch repair gene Mlh3 in familial esophageal cancer

    Institute of Scientific and Technical Information of China (English)

    Hong-Xu Liu; Yu Li; Xue-Dong Jiang; Hong-Nian Yin; Lin Zhang; Yu Wang; Jun Yang

    2006-01-01

    AIM: To shed light on the possible role of mismatch repair gene Mlh3 in familial esophageal cancer (FEC).METHODS: A total of 66 members from 10 families suggestive of a genetic predisposition to hereditary esophageal cancer were screened for germline mutations in Mlh3 with denaturing high performance liquid chromatography (DHPLC), a newly developed method of comparative sequencing based on heteroduplex detection. For all samples exhibiting abnormal DHPLC profiles,sequence changes were evaluated by cycle sequencing.For any mutation in family members, we conducted a segregation study to compare its prevalence in sporadic esophageal cancer patients and normal controls.RESULTS: Exons of Mlh3 in all samples were successfully examined. Overall, 4 missense mutations and 3 polymorphisms were identified in 4 families. Mlh3 missense mutations in families 9 and 10 might be pathogenic, but had a reduced penetrance. While in families 1 and 7,there was no sufficient evidence supporting the monogenic explanations of esophageal cancers in families.The mutations were found in 33% of high-risk families and 50% of low-risk families.CONCLUSION: Mlh3 is a high risk gene with a reduced penetrance in some families. However, it acts as a low risk gene for esophageal cancer in most families. Mutations of Mlh3 may work together with other genes in an accumulated manner and result in an increased risk of esophageal tumor. DHPLC is a robust and sensitive technique for screening gene mutations.

  8. Tissue-engineering strategies to repair joint tissue in osteoarthritis: nonviral gene-transfer approaches.

    Science.gov (United States)

    Madry, Henning; Cucchiarini, Magali

    2014-10-01

    Loss of articular cartilage is a common clinical consequence of osteoarthritis (OA). In the past decade, substantial progress in tissue engineering, nonviral gene transfer, and cell transplantation have provided the scientific foundation for generating cartilaginous constructs from genetically modified cells. Combining tissue engineering with overexpression of therapeutic genes enables immediate filling of a cartilage defect with an engineered construct that actively supports chondrogenesis. Several pioneering studies have proved that spatially defined nonviral overexpression of growth-factor genes in constructs of solid biomaterials or hydrogels is advantageous compared with gene transfer or scaffold alone, both in vitro and in vivo. Notably, these investigations were performed in models of focal cartilage defects, because advanced cartilage-repair strategies based on the principles of tissue engineering have not advanced sufficiently to enable resurfacing of extensively degraded cartilage as therapy for OA. These studies serve as prototypes for future technological developments, because they raise the possibility that cartilage constructs engineered from genetically modified chondrocytes providing autocrine and paracrine stimuli could similarly compensate for the loss of articular cartilage in OA. Because cartilage-tissue-engineering strategies are already used in the clinic, combining tissue engineering and nonviral gene transfer could prove a powerful approach to treat OA.

  9. Fibrin patch-based insulin-like growth factor-1 gene-modified stem cell transplantation repairs ischemic myocardium

    OpenAIRE

    Li, Jun; Zhu, Kai; Yang, Shan; WANG, YULIN; Guo, Changfa; Yin, Kanhua; Wang, Chunsheng; Lai, Hao

    2015-01-01

    Bone marrow mesenchymal stem cells (BMSCs), tissue-engineered cardiac patch, and therapeutic gene have all been proposed as promising therapy strategies for cardiac repair after myocardial infarction. In our study, BMSCs were modified with insulin-like growth factor-1 (IGF-1) gene, loaded into a fibrin patch, and then transplanted into a porcine model of ischemia/reperfusion (I/R) myocardium injury. The results demonstrated that IGF-1 gene overexpression could promote proliferation of endothe...

  10. Image reconstruction of mMR PET data using the open source software STIR

    Energy Technology Data Exchange (ETDEWEB)

    Markiewicz, Pawel [Centre for Medical Image Computing, University College London, London (United Kingdom); Thielemans, Kris [Institute of Nuclear Medicine, University College London, London (United Kingdom); Burgos, Ninon [Centre for Medical Image Computing, University College London, London (United Kingdom); Manber, Richard [Institute of Nuclear Medicine, University College London, London (United Kingdom); Jiao, Jieqing [Centre for Medical Image Computing, University College London, London (United Kingdom); Barnes, Anna [Institute of Nuclear Medicine, University College London, London (United Kingdom); Atkinson, David [Centre for Medical Imaging, University College London, London (United Kingdom); Arridge, Simon R [Centre for Medical Image Computing, University College London, London (United Kingdom); Hutton, Brian F [Institute of Nuclear Medicine, University College London, London (United Kingdom); Ourselin, Sébastien [Centre for Medical Image Computing, University College London, London (United Kingdom); Dementia Research Centre, University College London, London (United Kingdom)

    2014-07-29

    Simultaneous PET and MR acquisitions have now become possible with the new hybrid Biograph Molecular MR (mMR) scanner from Siemens. The purpose of this work is to create a platform for mMR 3D and 4D PET image reconstruction which would be freely accessible to the community as well as fully adjustable in order to obtain optimal images for a given research task in PET imaging. The proposed platform is envisaged to prove useful in developing novel and robust image bio-markers which could then be adapted for use on the mMR scanner.

  11. [Correlation between mismatch repair proteins status and clinicopathological characteristics in sporadic colorectal cancer patients].

    Science.gov (United States)

    Xiao, Z T; Zhang, R X; Zhao, Y; Peng, J H; Lu, S X; Zhang, H Z; Ding, P R; Wu, X J; Lu, Z H; Li, L R; Wan, D S; Pan, Z Z; Chen, G

    2017-04-25

    Objective: To explore the expression of mismatch repair (MMR) proteins in sporadic colorectal cancer (SCRC) patients, and its association with clinicopathological characteristics of SCRC. Methods: Patients with histologically confirmed colorectal cancer were consecutively recruited between December 2011 and June 2015 at Sun Yat-sen University Cancer Center. The exclusion criteria included multiple primary colorectal tumors, hereditary colorectal cancer (including Lynch syndrome, familial adenomatous polyposis), and the patients without the MMR proteins status tested. A total of 2 684 patients were included. Correlations of MMR proteins status and patients' demographics (including gender, age), tumor characteristics (site and differentiation) and TNM staging (excluding 315 SCRC patients receiving neoadjuvant therapy) were investigated. Results: The percentage of deficient MMR (dMMR) in these SCRC patients was 10.2%, and that of proficient MMR (pMMR) was 89.8%. The dMMR was more likely to be detected in younger (≤59 old years) SCRC patients compared to the elderly (>59 years) [12.7%(179/1 406)vs 7.5%(96/1 278), Pcolon cancer was significantly higher than that in left colon cancer and rectal cancer [22.7%(151/664)vs 7.2%(69/956)vs 5.2%(55/1 064), Pcolon mucinous adenocarcinoma among SCRC.

  12. 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.

  13. Molecular Mechanisms of Ultraviolet Radiation-Induced DNA Damage and Repair

    Directory of Open Access Journals (Sweden)

    Rajesh P. Rastogi

    2010-01-01

    Full Text Available DNA is one of the prime molecules, and its stability is of utmost importance for proper functioning and existence of all living systems. Genotoxic chemicals and radiations exert adverse effects on genome stability. Ultraviolet radiation (UVR (mainly UV-B: 280–315 nm is one of the powerful agents that can alter the normal state of life by inducing a variety of mutagenic and cytotoxic DNA lesions such as cyclobutane-pyrimidine dimers (CPDs, 6-4 photoproducts (6-4PPs, and their Dewar valence isomers as well as DNA strand breaks by interfering the genome integrity. To counteract these lesions, organisms have developed a number of highly conserved repair mechanisms such as photoreactivation, base excision repair (BER, nucleotide excision repair (NER, and mismatch repair (MMR. Additionally, double-strand break repair (by homologous recombination and nonhomologous end joining, SOS response, cell-cycle checkpoints, and programmed cell death (apoptosis are also operative in various organisms with the expense of specific gene products. This review deals with UV-induced alterations in DNA and its maintenance by various repair mechanisms.

  14. Horizontal gene transfer regulation in bacteria as a "spandrel" of DNA repair mechanisms.

    Directory of Open Access Journals (Sweden)

    Saliou Fall

    Full Text Available Horizontal gene transfer (HGT is recognized as the major force for bacterial genome evolution. Yet, numerous questions remain about the transferred genes, their function, quantity and frequency. The extent to which genetic transformation by exogenous DNA has occurred over evolutionary time was initially addressed by an in silico approach using the complete genome sequence of the Ralstonia solanacearum GMI1000 strain. Methods based on phylogenetic reconstruction of prokaryote homologous genes families detected 151 genes (13.3% of foreign origin in the R. solanacearum genome and tentatively identified their bacterial origin. These putative transfers were analyzed in comparison to experimental transformation tests involving 18 different genomic DNA positions in the genome as sites for homologous or homeologous recombination. Significant transformation frequency differences were observed among these positions tested regardless of the overall genomic divergence of the R. solanacearum strains tested as recipients. The genomic positions containing the putative exogenous DNA were not systematically transformed at the highest frequencies. The two genomic "hot spots", which contain recA and mutS genes, exhibited transformation frequencies from 2 to more than 4 orders of magnitude higher than positions associated with other genes depending on the recipient strain. These results support the notion that the bacterial cell is equipped with active mechanisms to modulate acquisition of new DNA in different genomic positions. Bio-informatics study correlated recombination "hot-spots" to the presence of Chi-like signature sequences with which recombination might be preferentially initiated. The fundamental role of HGT is certainly not limited to the critical impact that the very rare foreign genes acquired mainly by chance can have on the bacterial adaptation potential. The frequency to which HGT with homologous and homeologous DNA happens in the environment

  15. Stimulation of proteoglycan synthesis by glucuronosyltransferase-I gene delivery: a strategy to promote cartilage repair.

    Science.gov (United States)

    Venkatesan, N; Barré, L; Benani, A; Netter, P; Magdalou, J; Fournel-Gigleux, S; Ouzzine, M

    2004-12-28

    Osteoarthritis is a degenerative joint disease characterized by a progressive loss of articular cartilage components, mainly proteoglycans (PGs), leading to destruction of the tissue. We investigate a therapeutic strategy based on stimulation of PG synthesis by gene transfer of the glycosaminoglycan (GAG)-synthesizing enzyme, beta1,3-glucuronosyltransferase-I (GlcAT-I) to promote cartilage repair. We previously reported that IL-1beta down-regulated the expression and activity of GlcAT-I in primary rat chondrocytes. Here, by using antisense oligonucleotides, we demonstrate that GlcAT-I inhibition impaired PG synthesis and deposition in articular cartilage explants, emphasizing the crucial role of this enzyme in PG anabolism. Thus, primary chondrocytes and cartilage explants were engineered by lipid-mediated gene delivery to efficiently overexpress a human GlcAT-I cDNA. Interestingly, GlcAT-I overexpression significantly enhanced GAG synthesis and deposition as evidenced by (35)S-sulfate incorporation, histology, estimation of GAG content, and fluorophore-assisted carbohydrate electrophoresis analysis. Metabolic labeling and Western blot analyses further suggested that GlcAT-I expression led to an increase in the abundance rather than in the length of GAG chains. Importantly, GlcAT-I delivery was able to overcome IL-1beta-induced PG depletion and maintain the anabolic activity of chondrocytes. Moreover, GlcAT-I also restored PG synthesis to a normal level in cartilage explants previously depleted from endogenous PGs by IL-1beta-treatment. In concert, our investigations strongly indicated that GlcAT-I was able to control and reverse articular cartilage defects in terms of PG anabolism and GAG content associated with IL-1beta. This study provides a basis for a gene therapy approach to promote cartilage repair in degenerative joint diseases.

  16. Polymorphisms in DNA Repair Genes and Susceptibility to Glioma in a Chinese Population

    Directory of Open Access Journals (Sweden)

    Jun-Hong Guan

    2013-02-01

    Full Text Available The excision repair cross-complementing rodent repair deficiency complementation group 1 (ERCC1, and X-ray repair cross-complementing group 1 (XRCC1 genes appear to protect mammalian cells from the harmful effects of ionizing radiation. We conducted a large case-control study to investigate the association of polymorphisms in ERCC1 C118T, ERCC1 C8092A, XRCC1 A194T, XRCC1 A194T, and XRCC3 C241T, with glioma risk in a Chinese population. Five single nucleotide polymorphisms (SNPs were genotyped, using the MassARRAY IPLEX platform, in 443 glioma cases and 443 controls. Association analyses based on an χ2 test and binary logistic regression were performed to determine the odds ratio (OR and a 95% confidence interval (95% CI for each SNP. For XRCC1 Arg194Trp, the variant genotype T/T was strongly associated with a lower risk of glioma cancer when compared with the wild type C/C (OR = 2.45, 95% CI = 1.43–4.45. Individuals carrying the XRCC1 399A allele had an increased risk of glioma (OR = 1.33, 95% CI = 1.02–1.64. The XRCC3 241T/T genotype was associated with a strong increased glioma risk (OR = 3.78, 95% CI = 1.86–9.06. Further analysis of the interactions of two susceptibility-associated SNPs, XRCC1 Arg194Trp and XRCC3 Thr241Met, showed that the combination of the XRCC1 194T and XRCC3 241T alleles brought a large increase in glioma risk (OR = 2.75, 95% CI = 1.54–4.04. XRCC1 Arg194Trp, XRCC1 Arg399Gln, and XRCC3 C241T, appear to be associated with susceptibility to glioma in a Chinese population.

  17. Fibrin patch-based insulin-like growth factor-1 gene-modified stem cell transplantation repairs ischemic myocardium

    Science.gov (United States)

    Li, Jun; Zhu, Kai; Yang, Shan; Wang, Yulin; Guo, Changfa; Yin, Kanhua; Wang, Chunsheng

    2015-01-01

    Bone marrow mesenchymal stem cells (BMSCs), tissue-engineered cardiac patch, and therapeutic gene have all been proposed as promising therapy strategies for cardiac repair after myocardial infarction. In our study, BMSCs were modified with insulin-like growth factor-1 (IGF-1) gene, loaded into a fibrin patch, and then transplanted into a porcine model of ischemia/reperfusion (I/R) myocardium injury. The results demonstrated that IGF-1 gene overexpression could promote proliferation of endothelial cells and cardiomyocyte-like differentiation of BMSCs in vitro. Four weeks after transplantation of fibrin patch loaded with gene-modified BMSCs, IGF-1 overexpression could successfully promote angiogenesis, inhibit remodeling, increase grafted cell survival and reduce apoptosis. In conclusion, the integrated strategy, which combined fibrin patch with IGF-1 gene modified BMSCs, could promote the histological cardiac repair for a clinically relevant porcine model of I/R myocardium injury. PMID:25767192

  18. Vascular endothelial growth factor gene transfection to enhance the repair of avascular necrosis of the femoral head of rabbit

    Institute of Scientific and Technical Information of China (English)

    杨操; 杨述华; 杜靖远; 李进; 许伟华; 熊宇芳

    2003-01-01

    Objective To explore a new method for the therapy of avascular necrosis of the femoral head.Methods The recombinant plasmid pCD-hVEGF165 was mixed with collagen and was implanted in the necrotic femoral head. The expression of vascular endothelial growth factor (VEGF) was examined by RNA dot hybridization and immunohistochemical techniques. Repair of the femoral head was observed by histological and histomorphometric analysis.Results The expression of VEGF was detected in the femoral head transfected with the VEGF gene. The femoral head transfected with the VEGF gene showed a significant increase in angiogenesis 2 and 4 weeks after gene transfection and a significant increase in bone formation 6 and 8 weeks after gene transfection on histomorphometric analysis (P<0.01).Conclusions Transfection of the VEGF gene enhances bone tissue angiogenesis. Repair of osteonecrosis could be accelerated accordingly, thus providing a potential method for therapy of osteonecrosis.

  19. Enzymatic repair of selected cross-linked homoduplex molecules enhances nuclear gene rescue from Pompeii and Herculaneum remains.

    Science.gov (United States)

    Di Bernardo, Giovanni; Del Gaudio, Stefania; Cammarota, Marcella; Galderisi, Umberto; Cascino, Antonino; Cipollaro, Marilena

    2002-02-15

    Ancient DNA (aDNA) samples extracted from the bone remains of six equids buried by the Vesuvius eruption in 79 AD were investigated to test pre-amplification and enzymatic repair procedures designed to enhance the rescue of nuclear genes. The extracts, which proved all positive for Equidae mtDNA amplification, proved positive only four times out of 18 when tested for single-copy Equidae nuclear genes (epsilon globin, p53 and gamma interferon). Pre-amplification did not change the number of retrieved aDNA sequences but 10 times out of 14 enzymatic repair restored the amplifiability of the genes analysed, proving that repair increases the rate of successful rescue from 22 to alpha(lambda)mu(omicron)sigma(tau) 80%. These findings support the hypothesis that some of these cross-linked aDNA molecules, which are not completely separated when DNA is extracted under denaturing conditions, become homoduplex substrates for Pol I and/or T4 ligase action upon renaturation. aDNA authenticity is proved by the homology of the nucleotide sequences of loci tested to the corresponding modern Equidae sequences. Data also indicate that cross-linked homoduplex molecules selected by denaturation of the extract are repaired without any chimera formation. The general features of aDNA amplification with and without denaturation and enzymatic repair are discussed.

  20. p53 Gene repair with zinc finger nucleases optimised by yeast 1-hybrid and validated by Solexa sequencing.

    Directory of Open Access Journals (Sweden)

    Frank Herrmann

    Full Text Available The tumor suppressor gene p53 is mutated or deleted in over 50% of human tumors. As functional p53 plays a pivotal role in protecting against cancer development, several strategies for restoring wild-type (wt p53 function have been investigated. In this study, we applied an approach using gene repair with zinc finger nucleases (ZFNs. We adapted a commercially-available yeast one-hybrid (Y1H selection kit to allow rapid building and optimization of 4-finger constructs from randomized PCR libraries. We thus generated novel functional zinc finger nucleases against two DNA sites in the human p53 gene, near cancer mutation 'hotspots'. The ZFNs were first validated using in vitro cleavage assays and in vivo episomal gene repair assays in HEK293T cells. Subsequently, the ZFNs were used to restore wt-p53 status in the SF268 human cancer cell line, via ZFN-induced homologous recombination. The frequency of gene repair and mutation by non-homologous end-joining was then ascertained in several cancer cell lines, using a deep sequencing strategy. Our Y1H system facilitates the generation and optimisation of novel, sequence-specific four- to six-finger peptides, and the p53-specific ZFN described here can be used to mutate or repair p53 in genomic loci.

  1. p53 Gene Repair with Zinc Finger Nucleases Optimised by Yeast 1-Hybrid and Validated by Solexa Sequencing

    Science.gov (United States)

    Herrmann, Frank; Garriga-Canut, Mireia; Baumstark, Rebecca; Fajardo-Sanchez, Emmanuel; Cotterell, James; Minoche, André; Himmelbauer, Heinz; Isalan, Mark

    2011-01-01

    The tumor suppressor gene p53 is mutated or deleted in over 50% of human tumors. As functional p53 plays a pivotal role in protecting against cancer development, several strategies for restoring wild-type (wt) p53 function have been investigated. In this study, we applied an approach using gene repair with zinc finger nucleases (ZFNs). We adapted a commercially-available yeast one-hybrid (Y1H) selection kit to allow rapid building and optimization of 4-finger constructs from randomized PCR libraries. We thus generated novel functional zinc finger nucleases against two DNA sites in the human p53 gene, near cancer mutation ‘hotspots’. The ZFNs were first validated using in vitro cleavage assays and in vivo episomal gene repair assays in HEK293T cells. Subsequently, the ZFNs were used to restore wt-p53 status in the SF268 human cancer cell line, via ZFN-induced homologous recombination. The frequency of gene repair and mutation by non-homologous end-joining was then ascertained in several cancer cell lines, using a deep sequencing strategy. Our Y1H system facilitates the generation and optimisation of novel, sequence-specific four- to six-finger peptides, and the p53-specific ZFN described here can be used to mutate or repair p53 in genomic loci. PMID:21695267

  2. Ndrg3 gene regulates DSB repair during meiosis through modulation the ERK signal pathway in the male germ cells

    Science.gov (United States)

    Pan, Hongjie; Zhang, Xuan; Jiang, Hanwei; Jiang, Xiaohua; Wang, Liu; Qi, Qi; Bi, Yuan; Wang, Jian; Shi, Qinghua; Li, Runsheng

    2017-01-01

    The N-myc downstream regulated gene (NDRG) family consists of 4 members, NDRG-1, -2, -3, -4. Physiologically, we found Ndrg3, a critical gene which led to homologous lethality in the early embryo development, regulated the male meiosis in mouse. The expression of Ndrg3 was enhanced specifically in germ cells, and reached its peak level in the pachytene stage spermatocyte. Haplo-insufficiency of Ndrg3 gene led to sub-infertility during the male early maturation. In the Ndrg3+/− germ cells, some meiosis events such as DSB repair and synaptonemal complex formation were impaired. Disturbances on meiotic prophase progression and spermatogenesis were observed. In mechanism, the attenuation of pERK1/2 signaling was detected in the heterozygous testis. With our primary spermatocyte culture system, we found that lactate promoted DSB repair via ERK1/2 signaling in the male mouse germ cells in vitro. Deficiency of Ndrg3 gene attenuated the activation of ERK which further led to the aberrancy of DSB repair in the male germ cells in mouse. Taken together, we reported that Ndrg3 gene modulated the lactate induced ERK pathway to facilitate DSB repair in male germ cells, which further regulated meiosis and subsequently fertility in male mouse. PMID:28290521

  3. Ndrg3 gene regulates DSB repair during meiosis through modulation the ERK signal pathway in the male germ cells.

    Science.gov (United States)

    Pan, Hongjie; Zhang, Xuan; Jiang, Hanwei; Jiang, Xiaohua; Wang, Liu; Qi, Qi; Bi, Yuan; Wang, Jian; Shi, Qinghua; Li, Runsheng

    2017-03-14

    The N-myc downstream regulated gene (NDRG) family consists of 4 members, NDRG-1, -2, -3, -4. Physiologically, we found Ndrg3, a critical gene which led to homologous lethality in the early embryo development, regulated the male meiosis in mouse. The expression of Ndrg3 was enhanced specifically in germ cells, and reached its peak level in the pachytene stage spermatocyte. Haplo-insufficiency of Ndrg3 gene led to sub-infertility during the male early maturation. In the Ndrg3(+/-) germ cells, some meiosis events such as DSB repair and synaptonemal complex formation were impaired. Disturbances on meiotic prophase progression and spermatogenesis were observed. In mechanism, the attenuation of pERK1/2 signaling was detected in the heterozygous testis. With our primary spermatocyte culture system, we found that lactate promoted DSB repair via ERK1/2 signaling in the male mouse germ cells in vitro. Deficiency of Ndrg3 gene attenuated the activation of ERK which further led to the aberrancy of DSB repair in the male germ cells in mouse. Taken together, we reported that Ndrg3 gene modulated the lactate induced ERK pathway to facilitate DSB repair in male germ cells, which further regulated meiosis and subsequently fertility in male mouse.

  4. Recombination-dependent deletion formation in mammalian cells deficient in the nucleotide excision repair gene ERCC1.

    Science.gov (United States)

    Sargent, R G; Rolig, R L; Kilburn, A E; Adair, G M; Wilson, J H; Nairn, R S

    1997-11-25

    Nucleotide excision repair proteins have been implicated in genetic recombination by experiments in Saccharomyces cerevisiae and Drosophila melanogaster, but their role, if any, in mammalian cells is undefined. To investigate the role of the nucleotide excision repair gene ERCC1, the hamster homologue to the S. cerevisiae RADIO gene, we disabled the gene by targeted knockout. Partial tandem duplications of the adenine phosphoribosyltransferase (APRT) gene then were constructed at the endogenous APRT locus in ERCC1- and ERCC1+ cells. To detect the full spectrum of gene-altering events, we used a loss-of-function assay in which the parental APRT+ tandem duplication could give rise to APRT- cells by homologous recombination, gene rearrangement, or point mutation. Measurement of rates and analysis of individual APRT- products indicated that gene rearrangements (principally deletions) were increased at least 50-fold, whereas homologous recombination was affected little. The formation of deletions is not caused by a general effect of the ERCC1 deficiency on gene stability, because ERCC1- cell lines with a single wild-type copy of the APRT gene yielded no increase in deletions. Thus, deletion formation is dependent on the tandem duplication, and presumably the process of homologous recombination. Recombination-dependent deletion formation in ERCC1- cells is supported by a significant decrease in a particular class of crossover products that are thought to arise by repair of a heteroduplex intermediate in recombination. We suggest that the ERCC1 gene product in mammalian cells is involved in the processing of heteroduplex intermediates in recombination and that the misprocessed intermediates in ERCC1- cells are repaired by illegitimate recombination.

  5. Is hospital based MMR vaccination for children with egg allergy here to stay?

    LENUS (Irish Health Repository)

    Hawkes, C P

    2010-01-01

    Egg allergy is incorrectly considered to constitute a contraindication to MMR in the community, despite a long history of its safe administration to egg allergic children. The product insert perpetuates this misinformation but the Irish guidelines from the RCPI are unequivocal. We reviewed all paediatric cases vaccinated in our hospital in 2007-2008. Forty seven of 91 children receiving vaccinations in hospital, had been referred for MMR due to concerns regarding egg allergy. In 32% (n=15), GP referral for vaccination was made despite correspondence from the clinic advising routine vaccination in the community. Nineteen were second MMR immunisations, which should all have occurred in the community. Unnecessary hospital referral for MMR vaccination is an extra burden on hospital resources, and causes unwarranted anxiety amongst parents of children with egg allergy. A change in practice seems difficult to achieve, as many referrals happen despite individualised correspondence to GPs and other referring clinicians outlining the current guidelines.

  6. MMR (measles, mumps, and rubella) vaccine - what you need to know

    Science.gov (United States)

    ... taken in its entirety from the CDC MMR (Measles, Mumps, & Rubella) Vaccine Information Statement (VIS): www.cdc. ... Why get vaccinated? Measles, mumps, and rubella are serious ... common, especially among children. Measles Measles virus causes ...

  7. A survey of UK parental attitudes to the MMR vaccine and trust in medical authority.

    Science.gov (United States)

    Casiday, Rachel; Cresswell, Tricia; Wilson, Deb; Panter-Brick, Catherine

    2006-01-12

    Contested reports associating the MMR vaccine with autism have resulted in diminished confidence and uptake of the vaccine in the UK. This postal survey of parent's decisions, attitudes and use of information about MMR immunisation was constructed from questions derived from in-depth qualitative work. The setting was a Primary Care Trust in northeast England (N=996). Both MMR-accepting and refusing parents were supportive of immunisation, yet the high level of concern about the safety of the vaccine expressed even by parents who had immunised their children is worrying in its implications for public confidence and trust in health care. The findings suggest that the ability of practitioners to provide effective professional advice about MMR vaccine could be undermined if a government were to directly promote the vaccine to parents. Practitioners should continue to provide parents with accurate information, while communicating respect for parents' intentions to protect their children's health.

  8. The Gene Targeting Approach of Small Fragment Homologous Replacement (SFHR Alters the Expression Patterns of DNA Repair and Cell Cycle Control Genes

    Directory of Open Access Journals (Sweden)

    Silvia Pierandrei

    2016-01-01

    Full Text Available Cellular responses and molecular mechanisms activated by exogenous DNA that invades cells are only partially understood. This limits the practical use of gene targeting strategies. Small fragment homologous replacement (SFHR uses a small exogenous wild-type DNA fragment to restore the endogenous wild-type sequence; unfortunately, this mechanism has a low frequency of correction. In this study, we used a mouse embryonic fibroblast cell line with a stably integrated mutated gene for enhanced green fluorescence protein. The restoration of a wild-type sequence can be detected by flow cytometry analysis. We quantitatively analyzed the expression of 84 DNA repair genes and 84 cell cycle control genes. Peculiar temporal gene expression patterns were observed for both pathways. Different DNA repair pathways, not only homologous recombination, as well as the three main cell cycle checkpoints appeared to mediate the cellular response. Eighteen genes were selected as highly significant target/effectors of SFHR. We identified a wide interconnection between SFHR, DNA repair, and cell cycle control. Our results increase the knowledge of the molecular mechanisms involved in cell invasion by exogenous DNA and SFHR. Specific molecular targets of both the cell cycle and DNA repair machineries were selected for manipulation to enhance the practical application of SFHR.

  9. A peek into the possible future of management of articular cartilage injuries: gene therapy and scaffolds for cartilage repair.

    Science.gov (United States)

    Kim, Hubert T; Zaffagnini, Stefano; Mizuno, Shuichi; Abelow, Stephen; Safran, Marc R

    2006-10-01

    Two rapidly progressing areas of research will likely contribute to cartilage repair procedures in the foreseeable future: gene therapy and synthetic scaffolds. Gene therapy refers to the transfer of new genetic information to cells that contribute to the cartilage repair process. This approach allows for manipulation of cartilage repair at the cellular and molecular level. Scaffolds are the core technology for the next generation of autologous cartilage implantation procedures in which synthetic matrices are used in conjunction with chondrocytes. This approach can be improved further using bioreactor technologies to enhance the production of extracellular matrix proteins by chondrocytes seeded onto a scaffold. The resulting "neo-cartilage implant" matures within the bioreactor, and can then be used to fill cartilage defects.

  10. Phenotypic Heterogeneity by Germline Mismatch Repair Gene Defect in Lynch Syndrome Patients.

    Science.gov (United States)

    Hernâni-Eusébio, Jorge; Barbosa, Elisabete

    2016-10-01

    Introdução: A síndrome de Lynch é a forma hereditária mais comum de cancro colo-rectal, sendo também responsável por cancro do endométrio e de outros tipos. Associa-se a mutações germinativas nos genes de mismatch repair do ADN e a instabilidade de microssatélites. As mutações MLH1 e MSH2 têm um fenótipo de síndrome de Lynch ‘clássico’, sendo o MSH2 mais associado a cancro extra-cólico. Mutações do MSH6 e PMS2 têm um fenótipo atípico. A expressão clínica é heterogénea, existindo uma correlação entre o gene mismatch repair mutado e o padrão fenotípico. Material e Métodos: Análise retrospetiva dos dados clínicos de doentes que cumpriam os critérios de Amesterdão ou que tinha mutações nos genes mismatch repair, entre setembro de 2012 e outubro de 2015. Resultados: Identificámos 28 doentes. Dezassete tinham cancro colo-rectal sendo a localização no cólon direito predominante. Cinco tiveram cancro do endométrio (mediana da idade de diagnóstico – 53), sem qualquer mutação no MSH6. Cinco desenvolveram outros cancros. Todos os casos com mutações mismatch repair estudados tinham instabilidade de microssatélites. Discussão: Na maioria dos casos foi encontrada mutação no MSH2 apesar de o MLH1 ser descrito na literatura como o gene mais frequentemente mutado. Interessa dizer que os doentes com cancro colo-rectal não evidenciam uma tendência para ter muito infiltrado inflamatório. Na maioria dos casos foi realizada colectomia parcial apesar da incidência elevada de lesões síncronas e metácronas associadas. Histerectomia e anexectomia profilática foi realizada em doentes em menopausa/perimenopausa. Conclusão: O registo standardizado dos dados dos doentes poderá levar a um melhor acompanhamento e conhecimento desta síndrome. O uso das Guidelines de Bethesda poderá identificar novos casos que escapam aos critérios de Amesterdão. A pesquisa de instabilidade de microssatélites deve ser feita em muito maior n

  11. [The relationship between MMR vaccination level and the number of new cases of autism in children].

    Science.gov (United States)

    Mrozek-Budzyn, Dorota; Kiełtyka, Agnieszka

    2008-01-01

    The MMR vaccination coverage in Malopolskie voivodeship improved rapidly and finally reached a high level during last years. The number of new cases of autism spectrum disorders in children during that time revealed a slightly rising but not significant trend, while the number of childhood autism were stable. Ecological study showed no correlation between MMR vaccination and an increased risk of childhood autism and autism spectrum disorders in children.

  12. Role of the Mmr efflux pump in drug resistance in Mycobacterium tuberculosis.

    Science.gov (United States)

    Rodrigues, Liliana; Villellas, Cristina; Bailo, Rebeca; Viveiros, Miguel; Aínsa, José A

    2013-02-01

    Efflux pumps are membrane proteins capable of actively transporting a broad range of substrates from the cytoplasm to the exterior of the cell. Increased efflux activity in response to drug treatment may be the first step in the development of bacterial drug resistance. Previous studies showed that the efflux pump Mmr was significantly overexpressed in strains exposed to isoniazid. In the work to be described, we constructed mutants lacking or overexpressing Mmr in order to clarify the role of this efflux pump in the development of resistance to isoniazid and other drugs in M. tuberculosis. The mmr knockout mutant showed an increased susceptibility to ethidium bromide, tetraphenylphosphonium, and cetyltrimethylammonium bromide (CTAB). Overexpression of mmr caused a decreased susceptibility to ethidium bromide, acriflavine, and safranin O that was obliterated in the presence of the efflux inhibitors verapamil and carbonyl cyanide m-chlorophenylhydrazone. Isoniazid susceptibility was not affected by the absence or overexpression of mmr. The fluorometric method allowed the detection of a decreased efflux of ethidium bromide in the knockout mutant, whereas the overexpressed strain showed increased efflux of this dye. This increased efflux activity was inhibited in the presence of efflux inhibitors. Under our experimental conditions, we have found that efflux pump Mmr is mainly involved in the susceptibility to quaternary compounds such as ethidium bromide and disinfectants such as CTAB. The contribution of this efflux pump to isoniazid resistance in Mycobacterium tuberculosis still needs to be further elucidated.

  13. XRCC1 and XPD DNA repair gene polymorphisms: a potential risk factor for glaucoma in the Pakistani population

    NARCIS (Netherlands)

    Yousaf, S.; Khan, M.I.; Micheal, S.; Akhtar, F.; Ali, S.H.; Riaz, M.; Ali, M.; Lall, P.; Waheed, N.K.; Hollander, A.I. den; Ahmed, A.; Qamar, R.

    2011-01-01

    PURPOSE: The present study was designed to determine the association of polymorphisms of the DNA repair genes X-ray cross-complementing group 1 (XRCC1) (c.1316G>A [rs25487]) and xeroderma pigmentosum complementation group D (XPD) (c.2298A>C [rs13181]) with primary open-angle glaucoma (POAG) an

  14. Cloning, comparative mapping, and RNA expression of the mouse homologues of the Saccharomyces cerevisiae nucleotide excision repair gene RAD23.

    NARCIS (Netherlands)

    P.J. van der Spek (Peter); C.E. Visser (Cécile); F. Hanaoka (Fumio); B. Smit (Bep); A. Hagemeijer (Anne); D. Bootsma (Dirk); J.H.J. Hoeijmakers (Jan)

    1996-01-01

    textabstractThe Saccharomyces cerevisiae RAD23 gene is involved in nucleotide excision repair (NER). Two human homologs of RAD23, HHR23A and HHR23B (HGMW-approved symbols RAD23A and RAD23B), were previously isolated. The HHR23B protein is complexed with the protein defective in the cancer-prone

  15. Conserved pattern of antisense overlapping transcription in the homologous ERCC-1 and yeast RAD10 DNA repair gene regions.

    NARCIS (Netherlands)

    M. van Duin (Mark); J. van den Tol; J.H.J. Hoeijmakers (Jan); D. Bootsma (Dirk); I.P. Rupp; P. Reynolds (Paul); L. Prakash; S. Prakash

    1989-01-01

    textabstractWe report that the genes for the homologous Saccharomyces cerevisiae RAD10 and human ERCC-1 DNA excision repair proteins harbor overlapping antisense transcription units in their 3' regions. Since naturally occurring antisense transcription is rare in S. cerevisiae and humans (this is

  16. Genetic Variation in Base Excision Repair Pathway Genes, Pesticide Exposure, and Prostate Cancer Risk

    National Research Council Canada - National Science Library

    Kathryn Hughes Barry; Stella Koutros; Sonja I. Berndt; Gabriella Andreotti; Jane A. Hoppin; Dale P. Sandler; Laurie A. Burdette; Meredith Yeager; Laura E. Beane Freeman; Jay H. Lubin; Xiaomei Ma; Tongzhang Zheng; Michael C. R. Alavanja

    2011-01-01

    .... OBJECTIVES: Because base excision repair (BER) is the predominant pathway involved in repairing oxidative damage, we evaluated interactions between 39 pesticides and 394 tag single-nucleotide polymorphisms (SNPs...

  17. SNPs in DNA repair or oxidative stress genes and late subcutaneous fibrosis in patients following single shot partial breast irradiation

    OpenAIRE

    2012-01-01

    Abstract Background The aim of this study was to evaluate the potential association between single nucleotide polymorphisms related response to radiotherapy injury, such as genes related to DNA repair or enzymes involved in anti-oxidative activities. The paper aims to identify marker genes able to predict an increased risk of late toxicity studying our group of patients who underwent a Single Shot 3D-CRT PBI (SSPBI) after BCS (breast conserving surgery). Methods A total of 57 breast cancer pa...

  18. DNA Damage/Repair and Polymorphism of the hOGG1 Gene in Lymphocytes of AMD Patients

    Directory of Open Access Journals (Sweden)

    Katarzyna Wozniak

    2009-01-01

    Full Text Available Oxidative stress is thought to play a role in the pathogenesis of age-related macular degeneration (AMD. We determined the extent of oxidative DNA damage and the kinetics of its removal as well as the genotypes of the Ser326Cys polymorphism of the hOGG1 gene in lymphocytes of 30 wet AMD patients and 30 controls. Oxidative DNA damage induced by hydrogen peroxide and its repair were evaluated by the comet assay and DNA repair enzymes. We observed a higher extent of endogenous oxidative DNA damage and a lower efficacy of its repair in AMD patients as compared with the controls. We did not find any correlation between the extent of DNA damage and efficacy of DNA repair with genotypes of the Ser326Cys polymorphism. The results obtained suggest that oxidative DNA damage and inefficient DNA repair can be associated with AMD and the variability of the hOOG1 gene may not contribute to this association.

  19. DNA repair and gene targeting in plant end-joining mutants

    NARCIS (Netherlands)

    Jia, Qi

    2011-01-01

    DNA double-strand breaks (DSBs) can be repaired by homologous recombination (HR) or by non-homologous end joining (NHEJ). The latter mechanism is the major route for DSB repair in the somatic cells of higher eukaryotes, including plants. If we could manipulate the balance of the DSB repair pathways

  20. DNA repair and gene targeting in plant end-joining mutants

    NARCIS (Netherlands)

    Jia, Qi

    2011-01-01

    DNA double-strand breaks (DSBs) can be repaired by homologous recombination (HR) or by non-homologous end joining (NHEJ). The latter mechanism is the major route for DSB repair in the somatic cells of higher eukaryotes, including plants. If we could manipulate the balance of the DSB repair pathways

  1. Mismatch repair genes of Streptococcus pneumoniae: HexA confers a mutator phenotype in Escherichia coli by negative complementation.

    Science.gov (United States)

    Prudhomme, M; Méjean, V; Martin, B; Claverys, J P

    1991-11-01

    DNA repair systems able to correct base pair mismatches within newly replicated DNA or within heteroduplex molecules produced during recombination are widespread among living organisms. Evidence that such generalized mismatch repair systems evolved from a common ancestor is particularly strong for two of them, the Hex system of the gram-positive Streptococcus pneumoniae and the Mut system of the gram-negative Escherichia coli and Salmonella typhimurium. The homology existing between HexA and MutS and between HexB and MutL prompted us to investigate the effect of expressing hex genes in E. coli. Complementation of mutS or mutL mutations, which confer a mutator phenotype, was assayed by introducing on a multicopy plasmid the hexA and hexB genes, under the control of an inducible promoter, either individually or together in E. coli strains. No decrease in mutation rate was conferred by either hexA or hexB gene expression. However, a negative complementation effect was observed in wild-type E. coli cells: expression of hexA resulted in a typical Mut- mutator phenotype. hexB gene expression did not increase the mutation rate either individually or in conjunction with hexA. Since expression of hexA did not affect the mutation rate in mutS mutant cells and the hexA-induced mutator effect was recA independent, it is concluded that this effect results from inhibition of the Mut system. We suggest that HexA, like its homolog MutS, binds to mismatches resulting from replication errors, but in doing so it protects them from repair by the Mut system. In agreement with this hypothesis, an increase in mutS gene copy number abolished the hexA-induced mutator phenotype. HexA protein could prevent repair either by being unable to interact with Mut proteins or by producing nonfunctional repair complexes.

  2. Survey of unaffected BRCA and mismatch repair (MMR) mutation positive individuals.

    Science.gov (United States)

    McKinnon, Wendy; Banks, Kimberly C; Skelly, Joan; Kohlmann, Wendy; Bennett, Robin; Shannon, Kristen; Larson-Haidle, Joy; Ashakaga, Taka; Weitzel, Jeffrey N; Wood, Marie

    2009-01-01

    Many individuals do not proceed with cancer predisposition testing due to fears of genetic discrimination (GD). We report the results of a survey of 47 unaffected, mutation positive individuals regarding insurance outcomes. Participants recruited from six different Cancer Risk Programs across the country were queried about their experiences with health, life, and disability insurance, as well as employment issues. Eighty-seven percent of participants carried a BRCA mutation and 87% were part of a group insurance plan at the time of testing. Forty-seven percent of participants self-paid for testing. Less than 10% of participants reported that their results were placed in the general medical record, while 43% did not know where their results were placed. Due to concerns about GD, 13% of participants stated they avoided changing jobs. Thirteen percent stated that their at-risk relatives had not undergone testing for the familial mutation due to fears about GD. Adverse events following genetic testing included two denials from private health insurers, one denial for average life insurance coverage and one denial for additional disability insurance. There were no reports of job discrimination. Results suggest fear of GD is prevalent, yet data do not support evidence that GD exists.

  3. Basic fibroblast growth factor gene transfection in repair of internal carotid artery aneurysm wall

    Institute of Scientific and Technical Information of China (English)

    Lei Jiao; Ming Jiang; Jinghai Fang; Yinsheng Deng; Zejun Chen; Min Wu

    2012-01-01

    Surgery or interventional therapy has some risks in the treatment of cerebral aneurysm. We established an internal carotid artery aneurysm model by dripping elastase in the crotch of the right internal and external carotid arteries of New Zealand rabbits. Following model induction, lentivirus carrying basic fibroblast growth factor was injected through the ear vein. We found that the longer the action time of the lentivirus, the smaller the aneurysm volume. Moreover, platelet-derived growth factor expression in the aneurysm increased, but smooth muscle 22 alpha and hypertension-related gene 1 mRNA expression decreased. At 1, 2, 3, and 4 weeks following model establishment, following 1 week of injection of lentivirus carrying basic fibroblast growth factor, the later the intervention time, the more severe the blood vessel damage, and the bigger the aneurysm volume, the lower the smooth muscle 22 alpha and hypertension-related gene 1 mRNA expression. Simultaneously, platelet-derived growth factor expression decreased. These data suggest that recombinant lentivirus carrying basic fibroblast growth factor can repair damaged cells in the aneurysmal wall and inhibit aneurysm dynamic growth, and that the effect is dependent on therapeutic duration.

  4. Cell and gene therapy for arrhythmias: Repair of cardiac conduction damage

    Institute of Scientific and Technical Information of China (English)

    Yong-Fu Xiao

    2011-01-01

    Action potentials generated in the sinoatrial node(SAN)dominate the rhythm and rate of a healthy human heart.Subsequently,these action potentials propagate to the whole heart via its conduction system .Abnormalities of impulse generation and/or propagation in a heart can cause arrhythmias.For example,SAN dysfunction or conduction block of the atrioventricular node can lead to serious bradycardia which is currently treated with an implanted electronic pacemaker.On the other hand conduction damage may cause reentrant tachyarrhythmias which are primarily treated pharmacologically or by medical device-based therapies,including defibrillation and tissue ablation.However,drug therapies sometimes may not be effective or are associated with serious side effects.Device-based therapies for cardiac arrhythmias,even with well developed technology,still face inadequacies,limitations,hardware complications,and other challenges.Therefore,scientists are actively seeking other alternatives for antiarrhythmic therapy.In particular,cells and genes used for repairing cardiac conduction damage/defect have been investigated in various studies both in vitro and in vivo.Despite the complexities of the excitation and conduction systems of the heart,cell and gene-based strategies provide novel alternatives for treatment or cure of cardiac anhythmias.This review summarizes some highlights of recent research progress in this field.

  5. Expression Silence of DNA Repair Gene hMGMT Induced by RNA Interference

    Institute of Scientific and Technical Information of China (English)

    LI Xiu-ying; LAI Yan-dong

    2007-01-01

    Objective: MGMT protein expression has been associated with tumor resistance to alkylating agents. The objective of this paper is to construct the RNA interference vector which can specifically induce the expression silence of human DNA repair gene hMGMT. Methods: The hMGMT specific siRNA expression cassette was made by two steps PCR, linked with pUC19 to get pU6-MGMTi, co-transfected with pEGFP-C1 into 16HBE and screened by G418. The MGMT mRNA and protein levels were detected by RT-PCR and Western Blot respectively. Results: hMGMT specific RNA interfere vector pU6-MGMTi was constructed successfully. In transfected 16HBE cells MGMT mRNA level could hardly be detected and the protein level was only 10% of control. Conclusion: MGMT specific RNAi expression cassette can effectively inhibit MGMT expression. MGMT silence cell line was built by co-transfection technology, which offered condition for studying the gene function of MGMT.

  6. Characterisation of the promoter region of the human DNA-repair gene Rad51.

    Science.gov (United States)

    Hasselbach, L; Haase, S; Fischer, D; Kolberg, H C; Stürzbecher, H W

    2005-01-01

    Regulatory elements of the 5'-flanking region of the DNA-repair gene Rad51 were analysed to characterise pathological alterations of Rad51 mRNA expression during tumour development. Various fragments of the Rad51 promoter were cloned into the pGL3 reporter vector and the respective promoter activity was determined by luciferase assays in transfected U2-OS cells. Transcription factor binding was identified using Protein/DNA arrays. The region encompassing base pairs -204 to -58 was identified as crucial for Rad51 gene transcription. Down regulator sequences are present upstream (-305 to -204) and downstream (-48 and +204) of this core promoter element. Promoter activity is significantly enhanced by substituting G at the polymorphic positions +135 and +172 for C and T, respectively. Transcription factors Ets1/PEA3, E2F1, p53, EGR1, and Stat5 were identified as relevant for regulating expression of Rad51. We identified three separate cis-sequence elements within the Rad51 transcriptional promoter, one ensuring basal levels of expression and two elements limiting expression to relatively low levels. The characterisation of transcription factor binding might help to explain high-level expression of Rad51 in a variety of solid tumours. The polymorphic sites appear important for the increased risk of breast and/or ovarian cancer for BRCA2 mutation carriers.

  7. The effect of a DNA repair gene on cellular invasiveness: XRCC3 over-expression in breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Veronica L Martinez-Marignac

    Full Text Available Over-expression of DNA repair genes has been associated with resistance to radiation and DNA-damage induced by chemotherapeutic agents such as cisplatin. More recently, based on the analysis of genome expression profiling, it was proposed that over-expression of DNA repair genes enhances the invasive behaviour of tumour cells. In this study we present experimental evidence utilizing functional assays to test this hypothesis. We assessed the effect of the DNA repair proteins known as X-ray complementing protein 3 (XRCC3 and RAD51, to the invasive behavior of the MCF-7 luminal epithelial-like and BT20 basal-like triple negative human breast cancer cell lines. We report that stable or transient over-expression of XRCC3 but not RAD51 increased invasiveness in both cell lines in vitro. Moreover, XRCC3 over-expressing MCF-7 cells also showed a higher tumorigenesis in vivo and this phenotype was associated with increased activity of the metalloproteinase MMP-9 and the expression of known modulators of cell-cell adhesion and metastasis such as CD44, ID-1, DDR1 and TFF1. Our results suggest that in addition to its' role in facilitating repair of DNA damage, XRCC3 affects invasiveness of breast cancer cell lines and the expression of genes associated with cell adhesion and invasion.

  8. Mismatch repair balances leading and lagging strand DNA replication fidelity.

    Directory of Open Access Journals (Sweden)

    Scott A Lujan

    Full Text Available The two DNA strands of the nuclear genome are replicated asymmetrically using three DNA polymerases, α, δ, and ε. Current evidence suggests that DNA polymerase ε (Pol ε is the primary leading strand replicase, whereas Pols α and δ primarily perform lagging strand replication. The fact that these polymerases differ in fidelity and error specificity is interesting in light of the fact that the stability of the nuclear genome depends in part on the ability of mismatch repair (MMR to correct different mismatches generated in different contexts during replication. Here we provide the first comparison, to our knowledge, of the efficiency of MMR of leading and lagging strand replication errors. We first use the strand-biased ribonucleotide incorporation propensity of a Pol ε mutator variant to confirm that Pol ε is the primary leading strand replicase in Saccharomyces cerevisiae. We then use polymerase-specific error signatures to show that MMR efficiency in vivo strongly depends on the polymerase, the mismatch composition, and the location of the mismatch. An extreme case of variation by location is a T-T mismatch that is refractory to MMR. This mismatch is flanked by an AT-rich triplet repeat sequence that, when interrupted, restores MMR to > 95% efficiency. Thus this natural DNA sequence suppresses MMR, placing a nearby base pair at high risk of mutation due to leading strand replication infidelity. We find that, overall, MMR most efficiently corrects the most potentially deleterious errors (indels and then the most common substitution mismatches. In combination with earlier studies, the results suggest that significant differences exist in the generation and repair of Pol α, δ, and ε replication errors, but in a generally complementary manner that results in high-fidelity replication of both DNA strands of the yeast nuclear genome.

  9. Gene and pathway level analyses of germline DNA-repair gene variants and prostate cancer susceptibility using the iCOGS-genotyping array

    DEFF Research Database (Denmark)

    Saunders, Edward J; Dadaev, Tokhir; Leongamornlert, Daniel A

    2016-01-01

    BACKGROUND: Germline mutations within DNA-repair genes are implicated in susceptibility to multiple forms of cancer. For prostate cancer (PrCa), rare mutations in BRCA2 and BRCA1 give rise to moderately elevated risk, whereas two of B100 common, low-penetrance PrCa susceptibility variants identif...

  10. NPM-ALK mediates phosphorylation of MSH2 at tyrosine 238, creating a functional deficiency in MSH2 and the loss of mismatch repair.

    Science.gov (United States)

    Bone, K M; Wang, P; Wu, F; Wu, C; Li, L; Bacani, J T; Andrew, S E; Lai, R

    2015-05-15

    The vast majority of anaplastic lymphoma kinase-positive anaplastic large cell lymphoma (ALK+ALCL) tumors express the characteristic oncogenic fusion protein NPM-ALK, which mediates tumorigenesis by exerting its constitutive tyrosine kinase activity on various substrates. We recently identified MSH2, a protein central to DNA mismatch repair (MMR), as a novel binding partner and phosphorylation substrate of NPM-ALK. Here, using liquid chromatography-mass spectrometry, we report for the first time that MSH2 is phosphorylated by NPM-ALK at a specific residue, tyrosine 238. Using GP293 cells transfected with NPM-ALK, we confirmed that the MSH2(Y238F) mutant is not tyrosine phosphorylated. Furthermore, transfection of MSH2(Y238F) into these cells substantially decreased the tyrosine phosphorylation of endogenous MSH2. Importantly, gene transfection of MSH2(Y238F) abrogated the binding of NPM-ALK with endogenous MSH2, re-established the dimerization of MSH2:MSH6 and restored the sensitivity to DNA mismatch-inducing drugs, indicative of MMR return. Parallel findings were observed in two ALK+ALCL cell lines, Karpas 299 and SUP-M2. In addition, we found that enforced expression of MSH2(Y238F) into ALK+ALCL cells alone was sufficient to induce spontaneous apoptosis. In conclusion, our findings have identified NPM-ALK-induced phosphorylation of MSH2 at Y238 as a crucial event in suppressing MMR. Our studies have provided novel insights into the mechanism by which oncogenic tyrosine kinases disrupt MMR.

  11. Downregulation of homologous recombination DNA repair genes by HDAC inhibition in prostate cancer is mediated through the E2F1 transcription factor.

    Directory of Open Access Journals (Sweden)

    Sushant K Kachhap

    Full Text Available BACKGROUND: Histone deacetylase inhibitors (HDACis re-express silenced tumor suppressor genes and are currently undergoing clinical trials. Although HDACis have been known to induce gene expression, an equal number of genes are downregulated upon HDAC inhibition. The mechanism behind this downregulation remains unclear. Here we provide evidence that several DNA repair genes are downregulated by HDAC inhibition and provide a mechanism involving the E2F1 transcription factor in the process. METHODOLOGY/PRINCIPAL FINDINGS: Applying Analysis of Functional Annotation (AFA on microarray data of prostate cancer cells treated with HDACis, we found a number of genes of the DNA damage response and repair pathways are downregulated by HDACis. AFA revealed enrichment of homologous recombination (HR DNA repair genes of the BRCA1 pathway, as well as genes regulated by the E2F1 transcription factor. Prostate cancer cells demonstrated a decreased DNA repair capacity and an increased sensitization to chemical- and radio-DNA damaging agents upon HDAC inhibition. Recruitment of key HR repair proteins to the site of DNA damage, as well as HR repair capacity was compromised upon HDACi treatment. Based on our AFA data, we hypothesized that the E2F transcription factors may play a role in the downregulation of key repair genes upon HDAC inhibition in prostate cancer cells. ChIP analysis and luciferase assays reveal that the downregulation of key repair genes is mediated through decreased recruitment of the E2F1 transcription factor and not through active repression by repressive E2Fs. CONCLUSIONS/SIGNIFICANCE: Our study indicates that several genes in the DNA repair pathway are affected upon HDAC inhibition. Downregulation of the repair genes is on account of a decrease in amount and promoter recruitment of the E2F1 transcription factor. Since HDAC inhibition affects several pathways that could potentially have an impact on DNA repair, compromised DNA repair upon HDAC

  12. Gene polymorphisms of the DNA Repairing Genes APE1 and XRCC1 among Smoking Lung Cancer Egyptians

    Directory of Open Access Journals (Sweden)

    Rezk Ahmed Abd-ellateef Elbaz, Salim Abd-elhady Habib, Maha Ebraheem Esmael Ebraheem, Gamal Kamel EL-Ebidy, Lamiaa Mohamed Mahmoud Ramadan and Ahmed Settin

    2012-04-01

    Full Text Available Lung cancer is the leading cause of cancer-related mortality worldwide and is thus a major public health problem. DNA base damage or losses caused by endogenous and exogenous agents occur constantly at a high frequency in human cells. The removal or repair of damaged bases is an important mechanism in protecting the integrity of the genome. APE1 (Apurinic/Apyrimidinic Endonuclease 1 and XRCC1 (X-ray cross-complementing group1 are DNA repair proteins that play important roles in the base excision repair (BER pathway. The focus of this work is limited to the association between polymorphisms in the DNA repair genes, (APE1 Asp148Glu (2197 T→G and XRCC1 Arg399Gln (28152 G→A genotypes, cigarette smoking and lung cancer. This study has included 131 cases affected with lung cancers include; 33cases with small cell carcinoma (25.2% and 98 cases with non-small cell carcinoma (74.8%. They were recruited from oncology Center, Mansoura University, Egypt; in the period between April 2008 to March 2010. For comparison, a negative control group including 150 healthy individuals randomly selected from blood donors. Controls were selected by random sampling cancer-free individuals without a past history of cancer, who visited Mansoura University hospitals and provided peripheral blood between April 2008 and March 2010. DNA was extracted from the whole peripheral blood using generation DNA purification capture column kit (Gentra system, USA and genotyping for APE1 Glu148Asp and XRCC1 Arg399Gln polymorphisms was performed by a PCR--CTPP (PCR with confronting two-pair primers method. The collected data were organized and statistically analyzed using SPSS statistical computer package version 10 software. we observed that, There were no significant differences in the frequencies of the APE1 Asp148Glu (2197 T→G polymorphism of all genotypes and alleles in all lung cancer cases compared to all healthy controls. Also, there were no significant differences in the

  13. Cloning of the hexA mismatch-repair gene of Streptococcus pneumoniae and identification of the product.

    Science.gov (United States)

    Martin, B; Prats, H; Claverys, J P

    1985-01-01

    The hexA mismatch repair gene of Streptococcus pneumoniae has been cloned into multicopy plasmid vectors. The cloned hexA gene is expressed as judged from its ability to complement various chromosomal hexA- alleles. Its direction of transcription was defined and the functional limits were localized by original methods relying on homology-dependent integration of nonautonomous chimeric plasmids carrying chromosomal inserts into the chromosome. Comparison of the proteins encoded by recombinant plasmids and by restriction fragments allowed us to identify an Mr 94 000 protein as the probable product of the hexA gene.

  14. Use of the comet-FISH assay to compare DNA damage and repair in p53 and hTERT genes following ionizing radiation.

    Directory of Open Access Journals (Sweden)

    Declan J McKenna

    Full Text Available The alkaline single cell gel electrophoresis (comet assay can be combined with fluorescent in situ hybridisation (FISH methodology in order to investigate the localisation of specific gene domains within an individual cell. The number and position of the fluorescent signal(s provides information about the relative damage and subsequent repair that is occurring in the targeted gene domain(s. In this study, we have optimised the comet-FISH assay to detect and compare DNA damage and repair in the p53 and hTERT gene regions of bladder cancer cell-lines RT4 and RT112, normal fibroblasts and Cockayne Syndrome (CS fibroblasts following γ-radiation. Cells were exposed to 5Gy γ-radiation and repair followed for up to 60 minutes. At each repair time-point, the number and location of p53 and hTERT hybridisation spots was recorded in addition to standard comet measurements. In bladder cancer cell-lines and normal fibroblasts, the p53 gene region was found to be rapidly repaired relative to the hTERT gene region and the overall genome, a phenomenon that appeared to be independent of hTERT transcriptional activity. However, in the CS fibroblasts, which are defective in transcription coupled repair (TCR, this rapid repair of the p53 gene region was not observed when compared to both the hTERT gene region and the overall genome, proving the assay can detect variations in DNA repair in the same gene. In conclusion, we propose that the comet-FISH assay is a sensitive and rapid method for detecting differences in DNA damage and repair between different gene regions in individual cells in response to radiation. We suggest this increases its potential for measuring radiosensitivity in cells and may therefore have value in a clinical setting.

  15. Stimulation of DNA repair and increased light output in response to UV irradiation in Escherichia coli expressing lux genes.

    Science.gov (United States)

    Cutter, Kerry L; Alloush, Habib M; Salisbury, Vyv C

    2007-01-01

    It has previously been suggested that the evolutionary drive of bacterial bioluminescence is a mechanism of DNA repair. By assessing the UV sensitivity of Escherichia coli, it is shown that the survival of UV-irradiated E. coli constitutively expressing luxABCDE in the dark is significantly better than either a strain with no lux gene expression or the same strain expressing only luciferase (luxAB) genes. This shows that UV resistance is dependent on light output, and not merely on luciferase production. Also, bacterial survival was found to be dependent on the conditions following UV irradiation, as bioluminescence-mediated repair was not as efficient as repair in visible light. Moreover, photon emission revealed a dose-dependent increase in light output per cell after UV exposure, suggesting that increased lux gene expression correlates with UV-induced DNA damage. This phenomenon has been previously documented in organisms where the lux genes are under their natural luxR regulation but has not previously been demonstrated under the regulation of a constitutive promoter.

  16. c-Myc directly regulates the transcription of the NBS1 gene involved in DNA double-strand break repair.

    Science.gov (United States)

    Chiang, Yu-Chi; Teng, Shu-Chun; Su, Yi-Ning; Hsieh, Fon-Jou; Wu, Kou-Juey

    2003-05-23

    The c-myc proto-oncogene encodes a ubiquitous transcription factor involved in the control of cell growth and implicated in inducing tumorigenesis. Understanding the function of c-Myc and its role in cancer depends upon the identification of c-Myc target genes. Nijmegen breakage syndrome (NBS) is a chromosomal-instability syndrome associated with cancer predisposition, radiosensitivity, and chromosomal instability. The NBS gene product, NBS1 (p95 or nibrin), is a part of the hMre11 complex, a central player associated with double-strand break (DSB) repair. NBS1 contains domains characteristic for proteins involved in DNA repair, recombination, and replication. Here we show that c-Myc directly activates NBS1. c-Myc-mediated induction of NBS1 gene transcription occurs in different tissues, is independent of cell proliferation, and is mediated by a c-Myc binding site in the intron 1 region of NBS1 gene. Overexpression of NBS1 in Rat1a cells increased cell proliferation. These results indicate that NBS1 is a direct transcriptional target of c-Myc and links the function of c-Myc to the regulation of DNA DSB repair pathway operating during DNA replication.

  17. Gypenosides causes DNA damage and inhibits expression of DNA repair genes of human oral cancer SAS cells.

    Science.gov (United States)

    Lu, Kung-Wen; Chen, Jung-Chou; Lai, Tung-Yuan; Yang, Jai-Sing; Weng, Shu-Wen; Ma, Yi-Shih; Tang, Nou-Ying; Lu, Pei-Jung; Weng, Jing-Ru; Chung, Jing-Gung

    2010-01-01

    Gypenosides (Gyp) are the major components of Gynostemma pentaphyllum Makino, a Chinese medical plant. Recently, Gyp has been shown to induce cell cycle arrest and apoptosis in many human cancer cell lines. However, there is no available information to address the effects of Gyp on DNA damage and DNA repair-associated gene expression in human oral cancer cells. Therefore, we investigated whether Gyp induced DNA damage and DNA repair gene expression in human oral cancer SAS cells. The results from flow cytometric assay indicated that Gyp-induced cytotoxic effects led to a decrease in the percentage of viable SAS cells. The results from comet assay revealed that the incubation of SAS cells with Gyp led to a longer DNA migration smear (comet tail) when compared with control and this effect was dose-dependent. The results from real-time PCR analysis indicated that treatment of SAS cells with 180 mug/ml of Gyp for 24 h led to a decrease in 14-3-3sigma, DNA-dependent serine/threonine protein kinase (DNAPK), p53, ataxia telangiectasia mutated (ATM), ataxia-telangiectasia and Rad3-related (ATR) and breast cancer gene 1 (BRCA1) mRNA expression. These observations may explain the cell death caused by Gyp in SAS cells. Taken together, Gyp induced DNA damage and inhibited DNA repair-associated gene expressions in human oral cancer SAS cells in vitro.

  18. Manipulation of cell cycle progression can counteract the apparent loss of correction frequency following oligonucleotide-directed gene repair

    Directory of Open Access Journals (Sweden)

    Kmiec Eric B

    2007-02-01

    Full Text Available Abstract Background Single-stranded oligonucleotides (ssODN are used routinely to direct specific base alterations within mammalian genomes that result in the restoration of a functional gene. Despite success with the technique, recent studies have revealed that following repair events, correction frequencies decrease as a function of time, possibly due to a sustained activation of damage response signals in corrected cells that lead to a selective stalling. In this study, we use thymidine to slow down the replication rate to enhance repair frequency and to maintain substantial levels of correction over time. Results First, we utilized thymidine to arrest cells in G1 and released the cells into S phase, at which point specific ssODNs direct the highest level of correction. Next, we devised a protocol in which cells are maintained in thymidine following the repair reaction, in which the replication is slowed in both corrected and non-corrected cells and the initial correction frequency is retained. We also present evidence that cells enter a senescence state upon prolonged treatment with thymidine but this passage can be avoided by removing thymidine at 48 hours. Conclusion Taken together, we believe that thymidine may be used in a therapeutic fashion to enable the maintenance of high levels of treated cells bearing repaired genes.

  19. Contribution of DNA double-strand break repair gene XRCC3 genotypes to oral cancer susceptibility in Taiwan.

    Science.gov (United States)

    Tsai, Chia-Wen; Chang, Wen-Shin; Liu, Juhn-Cherng; Tsai, Ming-Hsui; Lin, Cheng-Chieh; Bau, Da-Tian

    2014-06-01

    The DNA repair gene X-ray repair cross complementing protein 3 (XRCC3) is thought to play a major role in double-strand break repair and in maintaining genomic stability. Very possibly, defective double-strand break repair of cells can lead to carcinogenesis. Therefore, a case-control study was performed to reveal the contribution of XRCC3 genotypes to individual oral cancer susceptibility. In this hospital-based research, the association of XRCC3 rs1799794, rs45603942, rs861530, rs3212057, rs1799796, rs861539, rs28903081 genotypes with oral cancer risk in a Taiwanese population was investigated. In total, 788 patients with oral cancer and 956 age- and gender-matched healthy controls were genotyped. The results showed that there was significant differential distribution among oral cancer and controls in the genotypic (p=0.001428) and allelic (p=0.0013) frequencies of XRCC3 rs861539. As for the other polymorphisms, there was no difference between case and control groups. In gene-lifestyle interaction analysis, we have provided the first evidence showing that there is an obvious joint effect of XRCC3 rs861539 genotype with individual areca chewing habits on oral cancer risk. In conclusion, the T allele of XRCC3 rs861539, which has an interaction with areca chewing habit in oral carcinogenesis, may be an early marker for oral cancer in Taiwanese.

  20. Escherichia coli radD (yejH) gene: a novel function involved in radiation resistance and double-strand break repair

    OpenAIRE

    Chen, Stefanie H.; Byrne, Rose T.; Wood, Elizabeth A; Cox, Michael M.

    2015-01-01

    A transposon insertion screen implicated the yejH gene in the repair of ionizing radiation-induced damage. The yejH gene, which exhibits significant homology to the human transcription-coupled DNA repair gene XPB, is involved in the repair of double strand DNA breaks. Deletion of yejH significantly sensitized cells to agents that cause double strand breaks (ionizing radiation, UV radiation, ciprofloxacin). In addition, deletion of both yejH and radA hypersensitized the cells to ionizing radia...

  1. Mating-type suppression of the DNA-repair defect of the yeast rad6 delta mutation requires the activity of genes in the RAD52 epistasis group.

    Science.gov (United States)

    Yan, Y X; Schiestl, R H; Prakash, L

    1995-06-01

    The RAD6 gene of Saccharomyces cerevisiae is required for post-replication repair of UV-damaged DNA, UV mutagenesis, and sporulation. Here, we show that the radiation sensitivity of a MATa rad6 delta strain can be suppressed by the MAT alpha 2 gene carried on a multicopy plasmid. The a1-alpha 2 suppression is specific to the RAD6 pathway, as mutations in genes required for nucleotide excision repair or for recombinational repair do not show such mating-type suppression. The a1-alpha 2 suppression of the rad6 delta mutation requires the activity of the RAD52 group of genes, suggesting that suppression occurs by channelling of post-replication gaps present in the rad6 delta mutant into the RAD52 recombinational repair pathway. The a1-alpha 2 repressor could mediate this suppression via an enhancement in the expression, or the activity, of recombination genes.

  2. Exome sequencing identifies rare deleterious mutations in DNA repair genes FANCC and BLM as potential breast cancer susceptibility alleles.

    Directory of Open Access Journals (Sweden)

    Ella R Thompson

    2012-09-01

    Full Text Available Despite intensive efforts using linkage and candidate gene approaches, the genetic etiology for the majority of families with a multi-generational breast cancer predisposition is unknown. In this study, we used whole-exome sequencing of thirty-three individuals from 15 breast cancer families to identify potential predisposing genes. Our analysis identified families with heterozygous, deleterious mutations in the DNA repair genes FANCC and BLM, which are responsible for the autosomal recessive disorders Fanconi Anemia and Bloom syndrome. In total, screening of all exons in these genes in 438 breast cancer families identified three with truncating mutations in FANCC and two with truncating mutations in BLM. Additional screening of FANCC mutation hotspot exons identified one pathogenic mutation among an additional 957 breast cancer families. Importantly, none of the deleterious mutations were identified among 464 healthy controls and are not reported in the 1,000 Genomes data. Given the rarity of Fanconi Anemia and Bloom syndrome disorders among Caucasian populations, the finding of multiple deleterious mutations in these critical DNA repair genes among high-risk breast cancer families is intriguing and suggestive of a predisposing role. Our data demonstrate the utility of intra-family exome-sequencing approaches to uncover cancer predisposition genes, but highlight the major challenge of definitively validating candidates where the incidence of sporadic disease is high, germline mutations are not fully penetrant, and individual predisposition genes may only account for a tiny proportion of breast cancer families.

  3. Polymorphism of the DNA repair gene XPA and susceptibility to lung cancer

    Institute of Scientific and Technical Information of China (English)

    Jinfu Zhu; Zhibin Hu; Hongxia Ma; Xiang Huo; Lin Xu; Jiannong Zhou; Hongbing Shen; Yijiang Chen

    2005-01-01

    Objective: To study the relationship between one polymorphism in the promoter of the DNA repair gene XPA and the susceptibility to lung cancer. Methods: Genotypes were determined by the PCR-restriction fragment length polymorphism (PCR-RFLP)method in 310 histologically-confirmed lung cancer cases and 341 age and sex frequency-matched cancer-free controls. Results: The XPA A23G genotype frequencies were 27.1% (AA), 42.9% (AG), and 30.0% (GG) in case patients and 21.1% (AA), 52.8% (AG),and 26.1% (GG) in control subjects. Multivariate logistic regression analysis revealed that individuals carrying at least one 23G variant allele (AG + GG genotypes) had a significantly decreased risk for lung cancer (adjusted OR = 0.66; 95% CI = 0.44- 0.98) compared with the wild-type genotype (23AA). Stratified analysis showed that the protective effect was more evident in subjects with a family history of cancer. Conclusion: These results suggest that the XPA A23G polymorphism may have a role in lung cancer susceptibility in this study population.

  4. Human INO80 chromatin-remodelling complex contributes to DNA double-strand break repair via the expression of Rad54B and XRCC3 genes.

    Science.gov (United States)

    Park, Eun-Jung; Hur, Shin-Kyoung; Kwon, Jongbum

    2010-10-15

    Recent studies have shown that the SWI/SNF family of ATP-dependent chromatin-remodelling complexes play important roles in DNA repair as well as in transcription. The INO80 complex, the most recently described member of this family, has been shown in yeast to play direct role in DNA DSB (double-strand break) repair without affecting the expression of the genes involved in this process. However, whether this function of the INO80 complex is conserved in higher eukaryotes has not been investigated. In the present study, we found that knockdown of hINO80 (human INO80) confers DNA-damage hypersensitivity and inefficient DSB repair. Microarray analysis and other experiments have identified the Rad54B and XRCC3 (X-ray repair complementing defective repair in Chinese-hamster cells 3) genes, implicated in DSB repair, to be repressed by hINO80 deficiency. Chromatin immunoprecipitation studies have shown that hINO80 binds to the promoters of the Rad54B and XRCC3 genes. Re-expression of the Rad54B and XRCC3 genes rescues the DSB repair defect in hINO80-deficient cells. These results suggest that hINO80 assists DSB repair by positively regulating the expression of the Rad54B and XRCC3 genes. Therefore, unlike yeast INO80, hINO80 can contribute to DSB repair indirectly via gene expression, suggesting that the mechanistic role of this chromatin remodeller in DSB repair is evolutionarily diversified.

  5. DNA repair: Dynamic defenders against cancer and aging

    Energy Technology Data Exchange (ETDEWEB)

    Fuss, Jill O.; Cooper, Priscilla K.

    2006-04-01

    (UV) component of sunlight. NER can be divided into two classes based on where the repair occurs. NER occurring in DNA that is not undergoing transcription (i.e., most of the genome) is called global genome repair (GGR or GGNER), while NER taking place in the transcribed strand of active genes is called transcription-coupled repair (TCR or TC-NER). We will explore NER in more detail below. Mismatch repair (MMR) is another type of excision repair that specifically removes mispaired bases resulting from replication errors. DNA damage can also result in breaks in the DNA backbone, in one or both strands. Single-strand breaks (SSBs) are efficiently repaired by a mechanism that shares common features with the later steps in BER. Double-strand breaks (DSBs) are especially devastating since by definition there is no intact complementary strand to serve as a template for repair, and even one unrepaired DSB can be lethal [3]. In cells that have replicated their DNA prior to cell division, the missing information can be supplied by the duplicate copy, or sister chromatid, and DSBs in these cells are faithfully repaired by homologous recombination involving the exchange of strands of DNA between the two copies. However, most cells in the body are non-dividing, and in these cells the major mechanism for repairing DSBs is by non-homologous end joining (NHEJ), which as the name implies involves joining two broken DNA ends together without a requirement for homologous sequence and which therefore has a high potential for loss of genetic information.

  6. Parotid swelling due to Hoshino strain following MMR vac-cination in iranian immunization program

    Institute of Scientific and Technical Information of China (English)

    Majid Avijgan; Mandana Moghni; Seyyed Kamyar Mostafavi Zadeh; Masoud Hafizi

    2008-01-01

    This paper reports two seronegative cases of parotid swelling following MMR vaccination,which contains Hoshino strain of mumps virus.This study showed a high,(5%)potential reactogenicity induced by Hoshino strain of current MMR vaccine administered in Iranian EPI.The rate of complication of parotid swelling follow-ing national immunization against mumps is more than natural infection.Based on the results of this report, there is the first report of occurrence of parotid swelling 31 days following MMR vaccination.This reaction or complication may not be dependent on the vaccine dose,because one of cases presented parotid swelling fol-lowing taking one fifth of conventional dose of vaccine.It must be considered this strain may be with high rate of complication and be the subject of change of mumps strain of this vaccine in national immunization program of Iran.

  7. Association between DNA damage response and repair genes and risk of invasive serous ovarian cancer.

    Directory of Open Access Journals (Sweden)

    Joellen M Schildkraut

    Full Text Available BACKGROUND: We analyzed the association between 53 genes related to DNA repair and p53-mediated damage response and serous ovarian cancer risk using case-control data from the North Carolina Ovarian Cancer Study (NCOCS, a population-based, case-control study. METHODS/PRINCIPAL FINDINGS: The analysis was restricted to 364 invasive serous ovarian cancer cases and 761 controls of white, non-Hispanic race. Statistical analysis was two staged: a screen using marginal Bayes factors (BFs for 484 SNPs and a modeling stage in which we calculated multivariate adjusted posterior probabilities of association for 77 SNPs that passed the screen. These probabilities were conditional on subject age at diagnosis/interview, batch, a DNA quality metric and genotypes of other SNPs and allowed for uncertainty in the genetic parameterizations of the SNPs and number of associated SNPs. Six SNPs had Bayes factors greater than 10 in favor of an association with invasive serous ovarian cancer. These included rs5762746 (median OR(odds ratio(per allele = 0.66; 95% credible interval (CI = 0.44-1.00 and rs6005835 (median OR(per allele = 0.69; 95% CI = 0.53-0.91 in CHEK2, rs2078486 (median OR(per allele = 1.65; 95% CI = 1.21-2.25 and rs12951053 (median OR(per allele = 1.65; 95% CI = 1.20-2.26 in TP53, rs411697 (median OR (rare homozygote = 0.53; 95% CI = 0.35 - 0.79 in BACH1 and rs10131 (median OR( rare homozygote = not estimable in LIG4. The six most highly associated SNPs are either predicted to be functionally significant or are in LD with such a variant. The variants in TP53 were confirmed to be associated in a large follow-up study. CONCLUSIONS/SIGNIFICANCE: Based on our findings, further follow-up of the DNA repair and response pathways in a larger dataset is warranted to confirm these results.

  8. FRAGILE HISTIDINE TRIAD GENE EXPRESSION AND ITS CORRALATION WITH MISMATCH REPAIR PROTEIN IN HUMAN SPORADIC COLORECTAL CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    姚成才; 林从尧

    2004-01-01

    Objective: To investigate the expression of fragile histidine triad (FHIT) gene and its correlation with clinicopathological features and correlation with mismatch repair protein (mainly MLH1 and MSH2) in human sporadic colorectal carcinoma (SCC). Methods:Immunohistochemistry SP method was used to determine the expression of FHIT, MLH1 and MSH2 protein in surgically resected specimens of 84 human SCC. Results:The positive rates of FHIT, MLH1 and MSH2 protein expression were 48.81%, 92.86% and 100% respectively.Loss or reduced expression of FHIT protein was not related with tumors clinicopathological features such as age, gender,tumors site and histological type (P>0.05), but was correlated with tumors invade depth, degree of the differentiation, Ducks' stage and metastasis (P<0.05). There was no relationship between FHIT gene expression and MLH1 protein (r=0.0991, P>0.05) and MSH2 protein (r=0.0000, P=l.00) expression in human SCC. Conclusion:Absent or reduction of FHIT gene expression consists of high proportion and is a frequent event in SCC. FHIT gene is involved in the development and progression of human SCC and may be a candidate tumors suppressor gene. The relationship between alteration of FHIT gene expression and mismatch repair protein (mainly MLH1 and MSH2)deserved further study in human SCC.

  9. Rearrangement of Rag-1 recombinase gene in DNA-repair deficient/immunodeficient wasted'' mice

    Energy Technology Data Exchange (ETDEWEB)

    Woloschak, G.E.; Weaver, P.; Churchill, M.; Chang-Liu, C-M. (Argonne National Lab., IL (United States)); Libertin, C.R. (Loyola Univ., Maywood, IL (United States))

    1992-01-01

    Mice recessive for the autosomal gene wasted'' (wst) display a disease pattern which includes increased sensitivity to the killing effects of ionizing radiation, immunodeficiency, and neurologic dysfunction. The recent cloning and characterization of recombinase genes (Rag-l/Rag-2) expressed in lymphoid and possibly central nervous system tissues prompted us to examine expression of these genes in DNA repair-deficient/immunodeficient wasted mice. Our results revealed that in thymus tissue, a small Rag-I transcript (1.0 kb) was detected in wst/wst mice that was not evident in thymus from control mice. In wst/[sm bullet] mice, a two-fold increase in Rag-1 mRNA was evident in thymus tissue. Rag-2 mRNA could only be detected in thymus tissue from wst/[sm bullet] and not from wst/wst or parental control BCF, mice. Southern blots revealed a rearrangement or deletion within the Rag-1 gene of affected wasted mice that was not evident in known strain-specific parental or littermate controls. These results support the idea that the Rag-1 gene may map at or near the locus for the wasted mutation. In addition, they suggest the importance of recombinase function in normal immune and central nervous system development as well as the potential contribution of this gene family to the normal repair of radiation-induced DNA damage.

  10. Polymorphisms in DNA repair genes, smoking, and bladder cancer risk: findings from the International Consortium of Bladder Cancer

    Science.gov (United States)

    Stern, Mariana C.; Lin, Jie; Figueroa, Jonine D.; Kelsey, Karl T.; Kiltie, Anne E.; Yuan, Jian-Min; Matullo, Giuseppe; Fletcher, Tony; Benhamou, Simone; Taylor, Jack A.; Placidi, Donatella; Zhang, Zuo-Feng; Steineck, Gunnar; Rothman, Nathaniel; Kogevinas, Manolis; Silverman, Debra; Malats, Nuria; Chanock, Stephen; Wu, Xifeng; Karagas, Margaret R.; Andrew, Angeline S.; Nelson, Heather H.; Bishop, D. Timothy; Sak, Sei Chung; Choudhury, Ananya; Barrett, Jennifer H; Elliot, Faye; Corral, Román; Joshi, Amit D.; Gago-Dominguez, Manuela; Cortessis, Victoria K.; Xiang, Yong-Bing; Vineis, Paolo; Sacerdote, Carlotta; Guarrera, Simonetta; Polidoro, Silvia; Allione, Alessandra; Gurzau, Eugen; Koppova, Kvetoslava; Kumar, Rajiv; Rudnai, Peter; Porru, Stefano; Carta, Angela; Campagna, Marcello; Arici, Cecilia; Park, SungShim Lani; Garcia-Closas, Montserrat

    2009-01-01

    Tobacco smoking is the most important and well-established bladder cancer risk factor, and a rich source of chemical carcinogens and reactive oxygen species that can induce damage to DNA in urothelial cells. Therefore, common variation in DNA repair genes might modify bladder cancer risk. In this study we present results from meta- and pooled analyses conducted as part of the International Consortium of Bladder Cancer. We included data on 10 single nucleotide polymorphisms corresponding to 7 DNA repair genes from 13 studies. Pooled- and meta-analyses included 5,282 cases and 5,954 controls of non-Latino white origin. We found evidence for weak but consistent associations with ERCC2 D312N (rs1799793) (per allele OR = 1.10; 95% CI = 1.01–1.19; p = 0.021), NBN E185Q (rs1805794) (per allele OR = 1.09; 95% CI = 1.01–1.18; p = 0.028), and XPC A499V (rs2228000) (per allele OR = 1.10; 95% CI = 1.00–1.21, p = 0.044). The association with NBN E185Q was limited to ever smokers (interaction p = 0.002), and was strongest for the highest levels of smoking dose and smoking duration. Overall, our study provides the strongest evidence to date for a role of common variants in DNA repair genes in bladder carcinogenesis. PMID:19706757

  11. Targeted Modification of Gene Function Exploiting Homology-Directed Repair of TALEN-Mediated Double-Strand Breaks in Barley.

    Science.gov (United States)

    Budhagatapalli, Nagaveni; Rutten, Twan; Gurushidze, Maia; Kumlehn, Jochen; Hensel, Goetz

    2015-07-06

    Transcription activator-like effector nucleases open up new opportunities for targeted mutagenesis in eukaryotic genomes. Similar to zinc-finger nucleases, sequence-specific DNA-binding domains can be fused with effector domains like the nucleolytically active part of FokI to induce double-strand breaks and thereby modify the host genome on a predefined target site via nonhomologous end joining. More sophisticated applications of programmable endonucleases involve the use of a DNA repair template facilitating homology-directed repair (HDR) so as to create predefined rather than random DNA sequence modifications. The aim of this study was to demonstrate the feasibility of editing the barley genome by precisely modifying a defined target DNA sequence resulting in a predicted alteration of gene function. We used gfp-specific transcription activator-like effector nucleases along with a repair template that, via HDR, facilitates conversion of gfp into yfp, which is associated with a single amino acid exchange in the gene product. As a result of co-bombardment of leaf epidermis, we detected yellow fluorescent protein accumulation in about three of 100 mutated cells. The creation of a functional yfp gene via HDR was unambiguously confirmed by sequencing of the respective genomic site. In addition to the allele conversion accomplished in planta, a readily screenable marker system is introduced that might be useful for optimization approaches in the field of genome editing.

  12. The Mutyh base excision repair gene influences the inflammatory response in a mouse model of ulcerative colitis.

    Directory of Open Access Journals (Sweden)

    Ida Casorelli

    Full Text Available BACKGROUND: The Mutyh DNA glycosylase is involved in the repair of oxidized DNA bases. Mutations in the human MUTYH gene are responsible for colorectal cancer in familial adenomatous polyposis. Since defective DNA repair genes might contribute to the increased cancer risk associated with inflammatory bowel diseases, we compared the inflammatory response of wild-type and Mutyh(-/- mice to oxidative stress. METHODOLOGY/PRINCIPAL FINDINGS: The severity of colitis, changes in expression of genes involved in DNA repair and inflammation, DNA 8-oxoguanine levels and microsatellite instability were analysed in colon of mice treated with dextran sulfate sodium (DSS. The Mutyh(-/- phenotype was associated with a significant accumulation of 8-oxoguanine in colon DNA of treated mice. A single DSS cycle induced severe acute ulcerative colitis in wild-type mice, whereas lesions were modest in Mutyh(-/- mice, and this was associated with moderate variations in the expression of several cytokines. Eight DSS cycles caused chronic colitis in both wild-type and Mutyh(-/- mice. Lymphoid hyperplasia and a significant reduction in Foxp3(+ regulatory T cells were observed only in Mutyh(-/- mice. CONCLUSIONS: The findings indicate that, in this model of ulcerative colitis, Mutyh plays a major role in maintaining intestinal integrity by affecting the inflammatory response.

  13. New single nucleotide polymorphisms (SNPs) in homologous recombination repair genes detected by microarray analysis in Polish breast cancer patients.

    Science.gov (United States)

    Romanowicz, Hanna; Strapagiel, Dominik; Słomka, Marcin; Sobalska-Kwapis, Marta; Kępka, Ewa; Siewierska-Górska, Anna; Zadrożny, Marek; Bieńkiewicz, Jan; Smolarz, Beata

    2016-11-30

    Breast cancer is the most common cause of malignancy and mortality in women worldwide. This study aimed at localising homologous recombination repair (HR) genes and their chromosomal loci and correlating their nucleotide variants with susceptibility to breast cancer. In this study, authors analysed the association between single nucleotide polymorphisms (SNPs) in homologous recombination repair genes and the incidence of breast cancer in the population of Polish women. Blood samples from 94 breast cancer patients were analysed as test group. Individuals were recruited into the study at the Department of Oncological Surgery and Breast Diseases of the Institute of the Polish Mother's Memorial Hospital in Lodz, Poland. Healthy controls (n = 500) were obtained from the Biobank Laboratory, Department of Molecular Biophysics, University of Lodz. Then, DNA of breast cancer patients was compared with one of the disease-free women. The test was supported by microarray analysis. Statistically significant correlations were identified between breast cancer and 3 not described previously SNPs of homologous recombination repair genes BRCA1 and BRCA2: rs59004709, rs4986852 and rs1799950. Further studies on larger groups are warranted to support the hypothesis of correlation between the abovementioned genetic variants and breast cancer risk.

  14. Transplantation of erythropoietin gene-modified neural stem cells improves the repair of injured spinal cord

    Directory of Open Access Journals (Sweden)

    Min-fei Wu

    2015-01-01

    Full Text Available The protective effects of erythropoietin on spinal cord injury have not been well described. Here, the eukaryotic expression plasmid pcDNA3.1 human erythropoietin was transfected into rat neural stem cells cultured in vitro. A rat model of spinal cord injury was established using a free falling object. In the human erythropoietin-neural stem cells group, transfected neural stem cells were injected into the rat subarachnoid cavity, while the neural stem cells group was injected with non-transfected neural stem cells. Dulbecco′s modified Eagle′s medium/F12 medium was injected into the rats in the spinal cord injury group as a control. At 1-4 weeks post injury, the motor function in the rat lower limbs was best in the human erythropoietin-neural stem cells group, followed by the neural stem cells group, and lastly the spinal cord injury group. At 72 hours, compared with the spinal cord injury group, the apoptotic index and Caspase-3 gene and protein expressions were apparently decreased, and the bcl-2 gene and protein expressions were noticeably increased, in the tissues surrounding the injured region in the human erythropoietin-neural stem cells group. At 4 weeks, the cavities were clearly smaller and the motor and somatosensory evoked potential latencies were remarkably shorter in the human erythropoietin-neural stem cells group and neural stem cells group than those in the spinal cord injury group. These differences were particularly obvious in the human erythropoietin-neural stem cells group. More CM-Dil-positive cells and horseradish peroxidase-positive nerve fibers and larger amplitude motor and somatosensory evoked potentials were found in the human erythropoietin-neural stem cells group and neural stem cells group than in the spinal cord injury group. Again, these differences were particularly obvious in the human erythropoietin-neural stem cells group. These data indicate that transplantation of erythropoietin gene-modified neural stem

  15. Transplantation of erythropoietin gene-modified neural stem cells improves the repair of injured spinal cord.

    Science.gov (United States)

    Wu, Min-Fei; Zhang, Shu-Quan; Gu, Rui; Liu, Jia-Bei; Li, Ye; Zhu, Qing-San

    2015-09-01

    The protective effects of erythropoietin on spinal cord injury have not been well described. Here, the eukaryotic expression plasmid pcDNA3.1 human erythropoietin was transfected into rat neural stem cells cultured in vitro. A rat model of spinal cord injury was established using a free falling object. In the human erythropoietin-neural stem cells group, transfected neural stem cells were injected into the rat subarachnoid cavity, while the neural stem cells group was injected with non-transfected neural stem cells. Dulbecco's modified Eagle's medium/F12 medium was injected into the rats in the spinal cord injury group as a control. At 1-4 weeks post injury, the motor function in the rat lower limbs was best in the human erythropoietin-neural stem cells group, followed by the neural stem cells group, and lastly the spinal cord injury group. At 72 hours, compared with the spinal cord injury group, the apoptotic index and Caspase-3 gene and protein expressions were apparently decreased, and the bcl-2 gene and protein expressions were noticeably increased, in the tissues surrounding the injured region in the human erythropoietin-neural stem cells group. At 4 weeks, the cavities were clearly smaller and the motor and somatosensory evoked potential latencies were remarkably shorter in the human erythropoietin-neural stem cells group and neural stem cells group than those in the spinal cord injury group. These differences were particularly obvious in the human erythropoietin-neural stem cells group. More CM-Dil-positive cells and horseradish peroxidase-positive nerve fibers and larger amplitude motor and somatosensory evoked potentials were found in the human erythropoietin-neural stem cells group and neural stem cells group than in the spinal cord injury group. Again, these differences were particularly obvious in the human erythropoietin-neural stem cells group. These data indicate that transplantation of erythropoietin gene-modified neural stem cells into the

  16. Transplantation of erythropoietin gene-modiifed neural stem cells improves the repair of injured spinal cord

    Institute of Scientific and Technical Information of China (English)

    Min-fei Wu; Shu-quan Zhang; Rui Gu; Jia-bei Liu; Ye Li; Qing-san Zhu

    2015-01-01

    The protective effects of erythropoietin on spinal cord injury have not been well described. Here, the eukaryotic expression plasmid pcDNA3.1 human erythropoietin was transfected into rat neural stem cells culturedin vitro. A rat model of spinal cord injury was established using a free falling object. In the human erythropoietin-neural stem cells group, transfected neural stem cells were injected into the rat subarachnoid cavity, while the neural stem cells group was inject-ed with non-transfected neural stem cells. Dulbecco’s modified Eagle’s medium/F12 medium was injected into the rats in the spinal cord injury group as a control. At 1–4 weeks post injury, the motor function in the rat lower limbs was best in the human erythropoietin-neural stem cells group, followed by the neural stem cells group, and lastly the spinal cord injury group. At 72 hours, compared with the spinal cord injury group, the apoptotic index and Caspase-3 gene and protein expressions were apparently decreased, and the bcl-2 gene and protein expressions were noticeably increased, in the tissues surrounding the injured region in the human erythro-poietin-neural stem cells group. At 4 weeks, the cavities were clearly smaller and the motor and somatosensory evoked potential latencies were remarkably shorter in the human erythropoi-etin-neural stem cells group and neural stem cells group than those in the spinal cord injury group. These differences were particularly obvious in the human erythropoietin-neural stem cells group. More CM-Dil-positive cells and horseradish peroxidase-positive nerve fibers and larger amplitude motor and somatosensory evoked potentials were found in the human erythro-poietin-neural stem cells group and neural stem cells group than in the spinal cord injury group. Again, these differences were particularly obvious in the human erythropoietin-neural stem cells group. These data indicate that transplantation of erythropoietin gene-modified neural stem cells into the

  17. Heteroduplex DNA mismatch repair system of Streptococcus pneumoniae: cloning and expression of the hexA gene.

    OpenAIRE

    Balganesh, T S; Lacks, S A

    1985-01-01

    Mutations affecting heteroduplex DNA mismatch repair in Streptococcus pneumoniae were localized in two genes, hexA and hexB, by fractionation of restriction fragments carrying mutant alleles. A fragment containing the hexA4 allele was cloned in the S. pneumoniae cloning system, and the hexA+ allele was introduced into the recombinant plasmid by chromosomal facilitation of plasmid transfer. Subcloning localized the functional hexA gene to a 3.5-kilobase segment of the cloned pneumococcal DNA. ...

  18. Two DNA repair and recombination genes in Saccharomyces cerevisiae, RAD52 and RAD54, are induced during meiosis

    Energy Technology Data Exchange (ETDEWEB)

    Cole, G.M.; Mortimer, R.K. (Univ. of California, Berkeley (United States)); Schild, D. (Lawrence Berkeley Lab., CA (United States))

    1989-07-01

    The DNA repair and recombination genes of Saccharomyces cerevisiae, RAD52 and RAD54, were transcriptionally induced approximately 10- to 15-fold in sporulating MATa/{alpha} cells. Congenic MATa/a cells, which did not sporulate, did not show similar increases. Assays of {beta}-galactosidase activity in strains harboring either a RAD52- or RAD54-lacZ gene fusion indicated that this induction occurred at a time concomitant with a commitment to meiotic recombination, as measured by prototroph formation from his1 heteroalleles.

  19. A small interfering RNA screen of genes involved in DNA repair identifies tumor-specific radiosensitization by POLQ knockdown

    DEFF Research Database (Denmark)

    Higgins, Geoff S; Prevo, Remko; Lee, Yin-Fai

    2010-01-01

    radiosensitivity are largely unknown. We have conducted a small interfering RNA (siRNA) screen of 200 genes involved in DNA damage repair aimed at identifying genes whose knockdown increased tumor radiosensitivity. Parallel siRNA screens were conducted in irradiated and unirradiated tumor cells (SQ20B...... polymerase ) as a potential tumor-specific target. Subsequent investigations showed that POLQ knockdown resulted in radiosensitization of a panel of tumor cell lines from different primary sites while having little or no effect on normal tissue cell lines. These findings raise the possibility that POLQ...

  20. RAD1 and RAD10, but not other excision repair genes, are required for double-strand break-induced recombination in Saccharomyces cerevisiae.

    Science.gov (United States)

    Ivanov, E L; Haber, J E

    1995-04-01

    HO endonuclease-induced double-strand breaks (DSBs) in the yeast Saccharomyces cerevisiae can be repaired by the process of gap repair or, alternatively, by single-strand annealing if the site of the break is flanked by directly repeated homologous sequences. We have shown previously (J. Fishman-Lobell and J. E. Haber, Science 258:480-484, 1992) that during the repair of an HO-induced DSB, the excision repair gene RAD1 is needed to remove regions of nonhomology from the DSB ends. In this report, we present evidence that among nine genes involved in nucleotide excision repair, only RAD1 and RAD10 are required for removal of nonhomologous sequences from the DSB ends. rad1 delta and rad10 delta mutants displayed a 20-fold reduction in the ability to execute both gap repair and single-strand annealing pathways of HO-induced recombination. Mutations in RAD2, RAD3, and RAD14 reduced HO-induced recombination by about twofold. We also show that RAD7 and RAD16, which are required to remove UV photodamage from the silent HML, locus, are not required for MAT switching with HML or HMR as a donor. Our results provide a molecular basis for understanding the role of yeast nucleotide excision repair gene and their human homologs in DSB-induced recombination and repair.

  1. Repair genes expression profile of MLH1, MSH2 and ATM in the normal oral mucosa of chronic smokers.

    Science.gov (United States)

    Alves, Mônica Ghislaine Oliveira; Carta, Celina Faig Lima; de Barros, Patrícia Pimentel; Issa, Jaqueline Scholz; Nunes, Fábio Daumas; Almeida, Janete Dias

    2017-01-01

    The aim of this study was to evaluate the effect of chronic smoking on the expression profile of the repair genes MLH1, MSH2 and ATM in the normal oral mucosa of chronic smokers and never smokers. The sample consisted of thirty exfoliative cytology smears per group obtained from Smokers and Never Smokers. Total RNA was extracted and expression of the MLH1, MSH2 and ATM genes were evaluated by quantitative real-time and immunocytochemistry. The gene and protein expression data were correlated to the clinical data. Gene expression was analyzed statistically using the Student t-test and Pearson's correlation coefficient, with pexpression of MLH1, MSH2, ATM and age, number of cigarettes consumed per day, time of smoking during life, smoking history or levels of CO in expired air. The expression of genes and proteins related to DNA repair mechanism MLH1, MSH2 and ATM in the normal oral mucosa of chronic smokers was reduced. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. DNA repair and damage pathway related cancer suppressor genes in low-dose-rate irradiated AKR/J an IR mice

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Hyun Soon; Bong, Jin Jong; Kang, Yumi; Choi, Moo Hyun; Lee, Hae Un; Yoo, Jae Young; Choi, Seung Jin; Kim, Hee Sun [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd, Gyeongju (Korea, Republic of); Lee, Kyung Mi [Global Research Lab, BAERI Institute, Dept. of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of)

    2012-11-15

    It has been reported that low-dose-rate radiation stimulates the immune response, prolongs life span and inhibits carcinogenesis. The high dose-rate radiation influences the expression of DNA repair and damage-related genes. In contrast, DNA repair and damage signaling triggered by low-dose-rate irradiation remain unclear. In the present study, we investigated the differential expression of DNA repair and damage pathway related genes in the thymus of AKR/J and ICR mice after 100th day low-dose-rate irradiation. Our findings demonstrated that low-dose-rate γ -radiation suppressed tumorigenesis.

  3. Simultaneous vaccination with MMR and DTaP-IPV-Hib and rate of hospital admissions with any infections

    DEFF Research Database (Denmark)

    Sørup, Signe; Benn, Christine S; Poulsen, Anja

    2016-01-01

    and inactivated vaccines may increase child mortality compared with the live vaccine alone. We examined the hypothesis that simultaneous administration of MMR and the inactivated DTaP-IPV-Hib vaccine compared with MMR alone is associated with higher incidence of infectious disease admissions. METHODS: Nationwide......BACKGROUND: In Denmark, live measles, mumps, and rubella vaccine (MMR) is associated with a reduced risk of infectious disease admissions, particularly for lower respiratory tract infections. In low-income countries, simultaneous vaccination (i.e. vaccination at the same visit) with live......, 4965 children had simultaneous MMR and DTaP-IPV-Hib as their most recent vaccination. Compared with MMR alone, simultaneous administration was associated with a higher rate of lower respiratory tract infections (adjusted incidence rate ratio (IRR), 1.27; 95% confidence interval (CI), 1...

  4. Failure to induce a DNA repair gene, RAD54, in Saccharomyces cerevisiae does not affect DNA repair or recombination phenotypes

    Energy Technology Data Exchange (ETDEWEB)

    Cole, G.M.; Mortimer, R.K. (Univ. of California, Berkeley (USA))

    1989-08-01

    The Saccharomyces cerevisiae RAD54 gene is transcriptionally regulated by a broad spectrum of DNA-damaging agents. Induction of RAD54 by DNA-damaging agents is under positive control. Sequences responsible for DNA damage induction (the DRS element) lie within a 29-base-pair region from -99 to -70 from the most proximal transcription start site. This inducible promoter element is functionally separable from a poly(dA-dT) region immediately downstream which is required for constitutive expression. Deletions which eliminate induction of RAD54 transcription by DNA damage but do not affect constitutive expression have no effect on growth or survival of noninducible strains relative to wild-type strains in the presence of DNA-damaging agents. The DRS element is also not required for homothallic mating type switching, transcriptional induction of RAD54 during meiosis, meiotic recombination, or spontaneous or X-ray-induced mitotic recombination. We find no phenotype for a lack of induction of RAD54 message via the damage-inducible DRS, which raises significant questions about the physiology of DNA damage induction in S. cerevisiae.

  5. Homology Requirements and Competition between Gene Conversion and Break-Induced Replication during Double-Strand Break Repair.

    Science.gov (United States)

    Mehta, Anuja; Beach, Annette; Haber, James E

    2017-02-02

    Saccharomyces cerevisiae mating-type switching is initiated by a double-strand break (DSB) at MATa, leaving one cut end perfectly homologous to the HMLα donor, while the second end must be processed to remove a non-homologous tail before completing repair by gene conversion (GC). When homology at the matched end is ≤150 bp, efficient repair depends on the recombination enhancer, which tethers HMLα near the DSB. Thus, homology shorter than an apparent minimum efficient processing segment can be rescued by tethering the donor near the break. When homology at the second end is ≤150 bp, second-end capture becomes inefficient and repair shifts from GC to break-induced replication (BIR). But when pol32 or pif1 mutants block BIR, GC increases 3-fold, indicating that the steps blocked by these mutations are reversible. With short second-end homology, absence of the RecQ helicase Sgs1 promotes gene conversion, whereas deletion of the FANCM-related Mph1 helicase promotes BIR. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Comparison Between helium cycle and Supercritical CO{sub 2} Cycle for MMR and AMR

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Seong Jun; Lee, Jeong Ik; Ahn, Yoon Han; Lee, Je Kyoung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-05-15

    Korea Atomic Energy Research Institute (KAERI) started the development of Mobile Multi-Purpose Reactor (MMR), which is a 10MWth gas-cooled reactor. MMR is aiming for maximizing mobility, high performance, durability and safety. This is in order to use the MMR for many purposes such as ship propulsion, train engine and so on. MMR generally uses helium Brayton cycle as a power conversion system since it can obtain very simple system arrangement with direct cycle. However, some researchers have proposed that the supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle can be more efficient energy converting cycle for the high temperature gas cooled reactor (HTGR) and the very high temperature reactor (VHTR) system as well. Thus, this paper is to compare helium Brayton cycle to the S-CO{sub 2} Brayton cycle in terms of the efficiency while varying turbine inlet temperature (T. I. T). A cascaded S-CO{sub 2} cycle which had been proposed by Argonne National laboratory (ANL) was used as the S-CO{sub 2} Brayton cycle configuration. This cycle is to overcome the mismatch of temperature drop between reactor coolant and CO{sub 2} through the reactor heat exchanger (RHX). Our research team reviewed the ANL research by using the in-house codes developed by the Korea Advanced institute of Science and Technology (KAIST) research team. The calculation error between the in-house code and previous result was -0.36%.

  7. Evaluation of cell proliferation, apoptosis, and dna-repair genes as potential biomarkers for ethanol-induced cns alterations

    Directory of Open Access Journals (Sweden)

    Hicks Steven D

    2012-10-01

    Full Text Available Abstract Background Alcohol use disorders (AUDs lead to alterations in central nervous system (CNS architecture along with impaired learning and memory. Previous work from our group and that of others suggests that one mechanism underlying these changes is alteration of cell proliferation, apoptosis, and DNA-repair in neural stem cells (NSCs produced as a consequence of ethanol-induced effects on the expression of genes related to p53-signaling. This study tests the hypothesis that changes in the expression of p53-signaling genes represent biomarkers of ethanol abuse which can be identified in the peripheral blood of rat drinking models and human AUD subjects and posits that specific changes may be correlated with differences in neuropsychological measures and CNS structure. Results Remarkably, microarray analysis of 350 genes related to p53-signaling in peripheral blood leukocytes (PBLs of binge-drinking rats revealed 190 genes that were significantly altered after correcting for multiple testing. Moreover, 40 of these genes overlapped with those that we had previously observed to be changed in ethanol-exposed mouse NSCs. Expression changes in nine of these genes were tested for independent confirmation by a custom QuantiGene Plex (QGP assay for a subset of p53-signaling genes, where a consistent trend for decreased expression of mitosis-related genes was observed. One mitosis-related gene (Pttg1 was also changed in human lymphoblasts cultured with ethanol. In PBLs of human AUD subjects seven p53-signaling genes were changed compared with non-drinking controls. Correlation and principal components analysis were then used to identify significant relationships between the expression of these seven genes and a set of medical, demographic, neuropsychological and neuroimaging measures that distinguished AUD and control subjects. Two genes (Ercc1 and Mcm5 showed a highly significant correlation with AUD-induced decreases in the volume of the left

  8. Evaluation of cell proliferation, apoptosis, and DNA-repair genes as potential biomarkers for ethanol-induced CNS alterations.

    Science.gov (United States)

    Hicks, Steven D; Lewis, Lambert; Ritchie, Julie; Burke, Patrick; Abdul-Malak, Ynesse; Adackapara, Nyssa; Canfield, Kelly; Shwarts, Erik; Gentile, Karen; Meszaros, Zsuzsa Szombathyne; Middleton, Frank A

    2012-10-25

    Alcohol use disorders (AUDs) lead to alterations in central nervous system (CNS) architecture along with impaired learning and memory. Previous work from our group and that of others suggests that one mechanism underlying these changes is alteration of cell proliferation, apoptosis, and DNA-repair in neural stem cells (NSCs) produced as a consequence of ethanol-induced effects on the expression of genes related to p53-signaling. This study tests the hypothesis that changes in the expression of p53-signaling genes represent biomarkers of ethanol abuse which can be identified in the peripheral blood of rat drinking models and human AUD subjects and posits that specific changes may be correlated with differences in neuropsychological measures and CNS structure. Remarkably, microarray analysis of 350 genes related to p53-signaling in peripheral blood leukocytes (PBLs) of binge-drinking rats revealed 190 genes that were significantly altered after correcting for multiple testing. Moreover, 40 of these genes overlapped with those that we had previously observed to be changed in ethanol-exposed mouse NSCs. Expression changes in nine of these genes were tested for independent confirmation by a custom QuantiGene Plex (QGP) assay for a subset of p53-signaling genes, where a consistent trend for decreased expression of mitosis-related genes was observed. One mitosis-related gene (Pttg1) was also changed in human lymphoblasts cultured with ethanol. In PBLs of human AUD subjects seven p53-signaling genes were changed compared with non-drinking controls. Correlation and principal components analysis were then used to identify significant relationships between the expression of these seven genes and a set of medical, demographic, neuropsychological and neuroimaging measures that distinguished AUD and control subjects. Two genes (Ercc1 and Mcm5) showed a highly significant correlation with AUD-induced decreases in the volume of the left parietal supramarginal gyrus and

  9. Quantitative comparison of PET performance—Siemens Biograph mCT and mMR

    Energy Technology Data Exchange (ETDEWEB)

    Karlberg, Anna M.; Sæther, Oddbjørn [Department of Radiology and Nuclear Medicine, St. Olavs Hospital, Olav Kyrres gt 17, 7006 Trondheim (Norway); Eikenes, Live [Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Postbox 8905, 7491 Trondheim (Norway); Goa, Pål Erik [Department of Radiology and Nuclear Medicine, St. Olavs Hospital, Olav Kyrres gt 17, 7006 Trondheim (Norway); Department of Physics, Norwegian University of Science and Technology, Trondheim (Norway)

    2016-02-25

    Integrated clinical whole-body PET/MR systems were introduced in 2010. In order to bring this technology into clinical usage, it is of great importance to compare the performance with the well-established PET/CT. The aim of this study was to evaluate PET performance, with focus on image quality, on Siemens Biograph mMR (PET/MR) and Siemens Biograph mCT (PET/CT). A direct quantitative comparison of the performance characteristics between the mMR and mCT system was performed according to National Electrical Manufacturers Association (NEMA) NU 2-2007 protocol. Spatial resolution, sensitivity, count rate and image quality were evaluated. The evaluation was supplemented with additional standardized uptake value (SUV) measurements. The spatial resolution was similar for the two systems. Average sensitivity was higher for the mMR (13.3 kcps/MBq) compared to the mCT system (10.0 kcps/MBq). Peak noise equivalent count rate (NECR) was slightly higher for the mMR (196 kcps @ 24.4 kBq/mL) compared to the mCT (186 kcps @ 30.1 kBq/mL). Scatter fractions in the clinical activity concentration range yielded lower values for the mCT (34.9 %) compared to those for the mMR (37.0 %). Best image quality of the systems resulted in approximately the same mean hot sphere contrast and a difference of 19 percentage points (pp) in mean cold contrast, in favour of the mCT. In general, point spread function (PSF) increased hot contrast and time of flight (TOF) increased both hot and cold contrast. Highest hot contrast for the smallest sphere (10 mm) was achieved with the combination of TOF and PSF on the mCT. Lung residual error was higher for the mMR (22 %) than that for the mCT (17 %), with no effect of PSF. With TOF, lung residual error was reduced to 8 % (mCT). SUV was accurate for both systems, but PSF caused overestimations for the 13-, 17- and 22-mm spheres. Both systems proved good performance characteristics, and the PET image quality of the mMR was close to that of the m

  10. ROLE OF MISMATCH REPAIR PROTEINS IN THE PROCESSING OF CISPLATIN INTERSTRAND CROSS-LINKS

    Science.gov (United States)

    Sawant, Akshada; Kothandapani, Anbarasi; Zhitkovich, Anatoly; Sobol, Robert W.; Patrick, Steve M.

    2015-01-01

    Mismatch repair (MMR) deficiency gives rise to cisplatin resistance and can lead to poor prognosis in cancers. Various models have been proposed to explain this low level of resistance caused due to loss of MMR proteins. We have shown that MMR proteins are required to maintain cisplatin interstrand cross-links (ICLs) on the DNA leading to increased cellular sensitivity. In our previous studies, we have shown that BER processing of the cisplatin ICLs is mutagenic. Polymerase β (Polβ) can generate mismatches which leads to the activation and the recruitment of mismatch repair proteins. In this paper, we distinguished between the requirement of different downstream MMR proteins for maintaining cisplatin sensitivity. We show that the MutSα (MSH2-MSH6) heterocomplex is required to maintain cisplatin sensitivity, whereas the Mutsβ complex has no effect. These results can be correlated with the increased repair of cisplatin ICLs and ICL induced DNA double strand breaks (DSBs) in the resistant cells. Moreover, we show that MLH1 proficient cells displayed a cisplatin sensitive phenotype when compared with the MLH1 deficient cells and the ATPase activity of MLH1 is essential to mediate this effect. Based on these results, we propose that MutSα as well as the downstream MMR pathway proteins are essential to maintain a cisplatin sensitive phenotype as a consequence of processing Polβ induced mismatches at sites flanking cisplatin ICLs. PMID:26519826

  11. Deficiency in nucleotide excision repair family gene activity, especially ERCC3, is associated with non-pigmented hair fiber growth.

    Directory of Open Access Journals (Sweden)

    Mei Yu

    Full Text Available We conducted a microarray study to discover gene expression patterns associated with a lack of melanogenesis in non-pigmented hair follicles (HF by microarray. Pigmented and non-pigmented HFs were collected and micro-dissected into the hair bulb (HB and the upper hair sheaths (HS including the bulge region. In comparison to pigmented HS and HBs, nucleotide excision repair (NER family genes ERCC1, ERCC2, ERCC3, ERCC4, ERCC5, ERCC6, XPA, NTPBP, HCNP, DDB2 and POLH exhibited statistically significantly lower expression in non- pigmented HS and HBs. Quantitative PCR verified microarray data and identified ERCC3 as highly differentially expressed. Immunohistochemistry confirmed ERCC3 expression in HF melanocytes. A reduction in ERCC3 by siRNA interference in human melanocytes in vitro reduced their tyrosinase production ability. Our results suggest that loss of NER gene function is associated with a loss of melanin production capacity. This may be due to reduced gene transcription and/or reduced DNA repair in melanocytes which may eventually lead to cell death. These results provide novel information with regard to melanogenesis and its regulation.

  12. Redox regulation of genome stability by effects on gene expression, epigenetic pathways and DNA damage/repair.

    Science.gov (United States)

    Mikhed, Yuliya; Görlach, Agnes; Knaus, Ulla G; Daiber, Andreas

    2015-08-01

    Reactive oxygen and nitrogen species (e.g. H2O2, nitric oxide) confer redox regulation of essential cellular signaling pathways such as cell differentiation, proliferation, migration and apoptosis. In addition, classical regulation of gene expression or activity, including gene transcription to RNA followed by translation to the protein level, by transcription factors (e.g. NF-κB, HIF-1α) and mRNA binding proteins (e.g. GAPDH, HuR) is subject to redox regulation. This review will give an update of recent discoveries in this field, and specifically highlight the impact of reactive oxygen and nitrogen species on DNA repair systems that contribute to genomic stability. Emphasis will be placed on the emerging role of redox mechanisms regulating epigenetic pathways (e.g. miRNA, DNA methylation and histone modifications). By providing clinical correlations we discuss how oxidative stress can impact on gene regulation/activity and vise versa, how epigenetic processes, other gene regulatory mechanisms and DNA repair can influence the cellular redox state and contribute or prevent development or progression of disease.

  13. Redox regulation of genome stability by effects on gene expression, epigenetic pathways and DNA damage/repair

    Directory of Open Access Journals (Sweden)

    Yuliya Mikhed

    2015-08-01

    Full Text Available Reactive oxygen and nitrogen species (e.g. H2O2, nitric oxide confer redox regulation of essential cellular signaling pathways such as cell differentiation, proliferation, migration and apoptosis. In addition, classical regulation of gene expression or activity, including gene transcription to RNA followed by translation to the protein level, by transcription factors (e.g. NF-κB, HIF-1α and mRNA binding proteins (e.g. GAPDH, HuR is subject to redox regulation. This review will give an update of recent discoveries in this field, and specifically highlight the impact of reactive oxygen and nitrogen species on DNA repair systems that contribute to genomic stability. Emphasis will be placed on the emerging role of redox mechanisms regulating epigenetic pathways (e.g. miRNA, DNA methylation and histone modifications. By providing clinical correlations we discuss how oxidative stress can impact on gene regulation/activity and vise versa, how epigenetic processes, other gene regulatory mechanisms and DNA repair can influence the cellular redox state and contribute or prevent development or progression of disease.

  14. DNA Repair Gene Polymorphisms in the Nucleotide Excision Repair Pathway and Lung Cancer Risk: A Meta-analysis

    Institute of Scientific and Technical Information of China (English)

    Chao-rong Mei; Meng Luo; Hong-mei Li; Wen-jun Deng; Qing-hua Zhou

    2011-01-01

    Objective: A number of studies have reported the association of “XPA”, “XPC”, “XPD/ERCC2” gene polymorphisms with lung cancer risk. However, the results were conflict. To clarify the impact of polymorphisms of “XPA”, “XPC”; “XPD/ERCC2”, on lung cancer risk, a meta-analysis was performed in this study. Methods: The electronic databases PubMed and Embase were retrieved for studies included in this meta-analysis by “XPA”; “XPC”, “XPD/ERCC2”, “lung”, “cancer/neoplasm/tumor/carcinoma”, “polymorphism” (An upper date limit of October, 31, 2009). A meta-analysis was performed to evaluate the relationship among XPA, XPC and XPD polymorphism and lung cancer risks. Results: A total of 31 publications retrieved from Pubmed and Embase included in this study. XPC A939C CC genotype increased lung cancer risk in total population (recessive genetic model: OR=1.23, 95% Cl:1.05-1.44;homozygote comparison: OR=1.21,95%Cl:1.02-1.43and CC vs. CA contrast: OR=1.25,95%Cl:1.06-1.48), except in Asians. XPD A751C, 751C allele and CC genotype also increased lung cancer risk in total population and in Caucasians (recessive genetic model: Total population: OR=1.20, 95%Cl:1.07-1.35). No significant correlation was found between XPD A751C and lung cancer risk in Asians and African Americans. XPD G312A AA genotype increased lung cancer risk in total population, in Asians and Caucasians(recessive genetic model: Total population: OR=1.20, 95%Cl:1.06-1.36). No significant association was found between XPA G23A, XPC C499T, XPD C156A and lung cancer risk. Conclusion: Our results suggest that the polymorphisms in XPC and XPD involve in lung cancer risks. XPA polymorphisms is less related to lung cancer risk.

  15. Association Between Polymorphisms of DNA Repair Gene XRCC1 and DNA Damage in Asbestos-Exposed Workers

    Institute of Scientific and Technical Information of China (English)

    XIAO-HONG ZHAO; GUANG JIA; YONG-QUAN LIU; SHAO-WEI LIU; LEI YAN; YU JIN; NIAN LIU

    2006-01-01

    Objective To compare the asbestos-induced DNA damage and repair capacities of DNA damage between 104 asbestos exposed workers and 101 control workers in Qingdao City of China and to investigate the possible association between polymorphisms in codon 399 of XRCC1 and susceptibility to asbestosis. Methods DNA damage levels in peripheral bloodlymphocytes were determined by comet assay, and XRCC 1 genetic polymorphisms of DNA samples from 51 asbestosis cases and 53 non-asbestosis workers with a similar asbestos exposure history were analyzed by PCR/RFLP. Results The basal comet scores (3.95±2.95) were significantly higher in asbestos-exposed workers than in control workers (0.10±0.28). After 1 h H2O2 stimulation, DNA damage of lymphocytes exhibited different increases. After a 4 h repair period, the comet scores were 50.98±19.53 in asbestos-exposed workers and 18.32±12.04 in controls. The residual DNA damage (RD) was significantly greater (P<0.01) in asbestos-exposed workers (35.62%) than in controls (27.75%). XRCC1 genetic polymorphism in 104 asbestos-exposed workers was not associated with increased risk of asbestosis. But compared with polymorphisms in the DNA repair gene XRCC1 (polymorphisms in codon 399) and the DNA damage induced by asbestos, the comet scores in asbestosis cases with Gln/Gln, Gln/Arg, and Arg/Arg were 40.26±18.94, 38.03±28.22, and 32.01±11.65, respectively, which were higher than those in non-asbestosis workers with the same genotypes (25.58±11.08, 37.08±14.74, and 29.38±10.15). There were significant differences in the comet scores between asbestosis cases and non-asbestosis workers with Gln/Gln by Student's t-test (P<0.05 or 0.01). The comet scores were higher in asbestosis workers with Gln/Gln than in those with Arg/Arg and in non-asbestosis workers exposed to asbestos, but without statistically significant difference. Conclusions Exposure to asbestos may be related to DNA damage or the capacity of cells to repair H2O2-induced

  16. Parents' champions vs. vested interests: Who do parents believe about MMR? A qualitative study

    Directory of Open Access Journals (Sweden)

    Petticrew Mark

    2007-03-01

    Full Text Available Abstract Background Despite the Government acting quickly to reassure parents about MMR safety following the publication of the 1998 paper by Wakefield and colleagues, MMR uptake declined. One of the reasons suggested for this decline is a loss of public trust in politicians and health professionals. The purpose of this analysis was to examine parents' views on the role the media, politicians and health professionals have played in providing credible evidence about MMR safety. Methods A qualitative focus group study conducted with parents living in Central Scotland. Eighteen focus groups were conducted with 72 parents (64 mothers and 8 fathers between November 2002 and March 2003. Purposive sampling was used to ensure maximum variation among parents. Results In the period after the MMR controversy, parents found it difficult to know who to trust to offer balanced and accurate information. The general consensus was that politicians were untrustworthy in matters of health. The motives of primary health care providers were suspected by some parents, who saw them as having a range of vested interests (including financial incentives. Among the sources of evidence seen by some parents as more credible were other parents, and Andrew Wakefield who was viewed as an important whistle-blower and champion of ordinary parents. Conclusion The provision of accurate information is only one aspect of helping parents make immunisation decisions. Establishing and maintaining trust in the information provided is also important. The MMR controversy may provide useful lessons for health professionals about trust and credibility that may be generalisable to future health controversies.

  17. Delayed adaptive immunity is related to higher MMR vaccine-induced antibody titers in children.

    Science.gov (United States)

    Strömbeck, Anna; Lundell, Anna-Carin; Nordström, Inger; Andersson, Kerstin; Adlerberth, Ingegerd; Wold, Agnes E; Rudin, Anna

    2016-04-01

    There are notable inter-individual variations in vaccine-specific antibody responses in vaccinated children. The aim of our study was to investigate whether early-life environmental factors and adaptive immune maturation prior and close to measles-mumps-rubella (MMR) immunization relate to magnitudes of vaccine-specific antibody titers. In the FARMFLORA birth cohort, including both farming and non-farming families, children were immunized with the MMR vaccine at 18 months of age. MMR vaccine-induced antibody titers were measured in plasma samples obtained at 36 months of age. Infants' blood samples obtained at birth, 3-5 days and at 4 and 18 months of age were analyzed for T- and B-cell numbers, proportions of naive and memory T and B cells, and fractions of putative regulatory T cells. Multivariate factor analyses show that higher anti-MMR antibody titers were associated with a lower degree of adaptive immune maturation, that is, lower proportions of memory T cells and a lower capacity of mononuclear cells to produce cytokines, but with higher proportions of putative regulatory T cells. Further, children born by cesarean section (CS) had significantly higher anti-measles titers than vaginally-born children; and CS was found to be associated with delayed adaptive immunity. Also, girls presented with significantly higher anti-mumps and anti-rubella antibody levels than boys at 36 months of age. These results indicate that delayed adaptive immune maturation before and in close proximity to immunization seems to be advantageous for the ability of children to respond with higher anti-MMR antibody levels after vaccination.

  18. A mutation in the XPB/ERCC3 DNA repair transcription gene, associated with trichothiodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Weeda, G.; Donker, I.; Vermeulen, W. [Erasmus Univ., Rotterdam (Netherlands)] [and others

    1997-02-01

    Trichothiodystrophy (TTD) is a rare, autosomal recessive disorder characterized by sulfur-deficient brittle hair and nails, mental retardation, impaired sexual development, and ichthyosis. Photosensitivity has been reported in {approximately}50% of the cases, but no skin cancer is associated with TTD. Virtually all photosensitive TTD patients have a deficiency in the nucleotide excision repair (NER) of UV-induced DNA damage that is indistinguishable from that of xeroderma pigmentosum (XP) complementation group D (XP-D) patients. DNA repair defects in XP-D are associated with two additional, quite different diseases; XP, a sun-sensitive and cancer-prone repair disorder, and Cockayne syndrome (CS), a photosensitive condition characterized by physical and mental retardation and wizened facial appearance. One photosensitive TTD case constitutes a new repair-deficient complementation group, TTD-A. Remarkably, both TTD-A and XP-D defects are associated with subunits of TFIIH, a basal transcription factor with a second function in DNA repair. Thus, mutations in TFIIH components may, on top of a repair defect, also cause transcriptional insufficiency, which may explain part of the non-XP clinical features of TTD. To date, three patients with the remarkable conjunction of XP and CS but not TM have been assigned to XP complementation group B (XP-B). Here we present the characterization of the NER defect in two mild TTD patients (TTD6VI and TTD4VI) and confirm the assignment to X-PB. The causative mutation was found to be a single base substitution resulting in a missense mutation (T119P) in a region of the XPB protein. These findings define a third TTD complementation group, extend the clinical heterogeneity associated with XP-B, stress the exclusive relationship between TTD and mutations in subunits of repair/transcription factor TFIIH, and strongly support the concept of {open_quotes}transcription syndromes.{close_quotes} 46 refs., 6 figs., 2 tabs.

  19. Gene Expression Profiling in the Injured Spinal Cord of Trachemys scripta elegans: An Amniote with Self-Repair Capabilities

    Science.gov (United States)

    Valentin-Kahan, Adrián; García-Tejedor, Gabriela B.; Robello, Carlos; Trujillo-Cenóz, Omar; Russo, Raúl E.; Alvarez-Valin, Fernando

    2017-01-01

    Slider turtles are the only known amniotes with self-repair mechanisms of the spinal cord that lead to substantial functional recovery. Their strategic phylogenetic position makes them a relevant model to investigate the peculiar genetic programs that allow anatomical reconnection in some vertebrate groups but are absent in others. Here, we analyze the gene expression profile of the response to spinal cord injury (SCI) in the turtle Trachemys scripta elegans. We found that this response comprises more than 1000 genes affecting diverse functions: reaction to ischemic insult, extracellular matrix re-organization, cell proliferation and death, immune response, and inflammation. Genes related to synapses and cholesterol biosynthesis are down-regulated. The analysis of the evolutionary distribution of these genes shows that almost all are present in most vertebrates. Additionally, we failed to find genes that were exclusive of regenerating taxa. The comparison of expression patterns among species shows that the response to SCI in the turtle is more similar to that of mice and non-regenerative Xenopus than to Xenopus during its regenerative stage. This observation, along with the lack of conserved “regeneration genes” and the current accepted phylogenetic placement of turtles (sister group of crocodilians and birds), indicates that the ability of spinal cord self-repair of turtles does not represent the retention of an ancestral vertebrate character. Instead, our results suggest that turtles developed this capability from a non-regenerative ancestor (i.e., a lineage specific innovation) that was achieved by re-organizing gene expression patterns on an essentially non-regenerative genetic background. Among the genes activated by SCI exclusively in turtles, those related to anoxia tolerance, extracellular matrix remodeling, and axonal regrowth are good candidates to underlie functional recovery. PMID:28223917

  20. DNA damage and DNA mismatch repair of plants under adverse circumstance stress: A review%逆境胁迫下植物DNA损伤和DNA错配修复研究进展

    Institute of Scientific and Technical Information of China (English)

    钟鸣; 陈琢; 刘宛; 李培军; 台培东

    2012-01-01

    The genomic DNAs in plants are quite stable in normal circumstances, but easily to be damaged under adverse circumstance stresses such as chemical mutagens, ultraviolet ray, ionizing radiation, and fungal and bacteria toxins, as well as the reactive oxygen free radicals generated in plant metabolic processes. The main DNA lesions are the altered bases, apurinic/apyrimi-dinic (AP)-sites, mismatch base, deletion or insertion, linked pyrimidines, DNA adducts, DNA strand breaks, methylated damage, and intra- and inter-strand crosslinks. These DNA lesions could be genotoxic or cytotoxic to plant cells, while the repair of the DNA lesions is the basis of the plant antagonism to all kinds of damage. This paper summarized the research progress on the DNA damage (methylated damage, and DNA adducts) and DNA mismatch repair (procaryotic organism MMR, botanic MMR, and microsatellite instability) of plants. It was considered that in the bioremediation of environmental contaminants and in the early diagnosis and assessment of environmental pollution, plant DNA mismatch repair genes and MMR mutants would have higher application prospective.%在正常条件下植物体内的基因组是稳定的,但在逆境胁迫条件下(如化学诱变物、紫外线、电离辐射、细菌及真菌毒素、以及代谢过程中产生的活性氧自由基等),细胞DNA容易遭受伤害,其主要损伤形式为碱基改变、脱碱基位点、碱基错配、插入或缺失、嘧啶联合、DNA加合物、DNA链断裂、甲基化损伤、DNA链内和链间交联.这些受损伤的DNA对植物细胞产生遗传毒性或细胞毒性.对DNA损伤进行修复则是机体抵御各种伤害的基础.本文介绍了植物DNA损伤(甲基化损伤、DNA加合物等)和DNA错配修复(DNA mismatch repair,MMR)(原核生物MMR、植物的MMR、植物微卫星的不稳定性)的研究进展.认为植物DNA错配修复基因及MMR突变体在环境毒物生物修复和环境污染的早期诊断与评价方面具有较高的应用前景.

  1. PAH-DNA adducts in environmentally exposed population in relation to metabolic and DNA repair gene polymorphisms

    Energy Technology Data Exchange (ETDEWEB)

    Binkova, Blanka [Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 14220 Prague (Czech Republic); Chvatalova, Irena [Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 14220 Prague (Czech Republic); Lnenickova, Zdena [Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 14220 Prague (Czech Republic); Milcova, Alena [Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 14220 Prague (Czech Republic); Tulupova, Elena [Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 14220 Prague (Czech Republic); Cancer Biomarkers and Prevention Group, Biocentre, University of Leicester (United Kingdom); Farmer, Peter B. [Cancer Biomarkers and Prevention Group, Biocentre, University of Leicester (United Kingdom); Sram, Radim J. [Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine AS CR and Health Institute of Central Bohemia, Videnska 1083, 14220 Prague (Czech Republic)]. E-mail: sram@biomed.cas.cz

    2007-07-01

    Epidemiologic studies indicate that prolonged exposure to particulate air pollution may be associated with increased risk of cardiovascular diseases and cancer in general population. These effects may be attributable to polycyclic aromatic hydrocarbons (PAHs) adsorbed to respirable air particles. It is expected that metabolic and DNA repair gene polymorphisms may modulate individual susceptibility to PAH exposure. This study investigates relationships between exposure to PAHs, polymorphisms of these genes and DNA adducts in group of occupationally exposed policemen (EXP, N = 53, males, aged 22-50 years) working outdoors in the downtown area of Prague and in matched 'unexposed' controls (CON, N = 52). Personal exposure to eight carcinogenic PAHs (c-PAHs) was evaluated by personal samplers during working shift prior to collection of biological samples. Bulky-aromatic DNA adducts were analyzed in lymphocytes by {sup 32}P-postlabeling assay. Polymorphisms of metabolizing (GSTM1, GSTP1, GSTT1, EPHX1, CYP1A1-MspI) and DNA repair (XRCC1, XPD) genes were determined by PCR-based RFLP assays. As potential modifiers and/or cofounders, urinary cotinine levels were analyzed by radioimmunoassay, plasma levels of vitamins A, C, E and folates by HPLC, cholesterol and triglycerides using commercial kits. During the sampling period ambient particulate air pollution was as follows: PM10 32-55 {mu}g/m{sup 3}, PM2.5 27-38 {mu}g/m{sup 3}, c-PAHs 18-22 ng/m{sup 3}; personal exposure to c-PAHs: 9.7 ng/m{sup 3} versus 5.8 ng/m{sup 3} (P < 0.01) for EXP and CON groups, respectively. The total DNA adduct levels did not significantly differ between EXP and CON groups (0.92 {+-} 0.28 adducts/10{sup 8} nucleotides versus 0.82 {+-} 0.23 adducts/10{sup 8} nucleotides, P = 0.065), whereas the level of the B[a]P-'like' adduct was significantly higher in exposed group (0.122 {+-} 0.036 adducts/10{sup 8} nucleotides versus 0.099 {+-} 0.035 adducts/10{sup 8} nucleotides, P = 0

  2. High prevalence of deficient mismatch repair phenotype and the V600E BRAF mutation in elderly patients with colorectal cancer.

    Science.gov (United States)

    Aparicio, Thomas; Schischmanoff, Olivier; Poupardin, Cecile; Mary, Florence; Soufir, Nadem; Barrat, Christophe; Bellaiche, Guy; Boubaya, Marouane; Choudat, Laurence; Cucherousset, Joel; DesGuetz, Gaetan; Wind, Philippe; Benamouzig, Robert

    2014-10-01

    Colorectal cancer (CRC) occurs mostly in the elderly. However, the biology of CRC in elderly has been poorly studied. This study examined the prevalence of deficient mismatch repair phenotype (dMMR) and BRAF mutations according to age. MMR phenotype was prospectively determined by molecular analysis in patients of all ages undergoing surgery for CRC. BRAF V600E mutation status was analysed in a subset of dMMR tumours. A total of 754 patients who underwent surgery between 2005 and 2008 were included in the study. Amongst them, 272 (36%) were ≥75years old. The proportion of women prevalence of dMMR was 19.4% in patients ≥75 and 10.7% in patients prevalence of dMMR was significantly higher in women than in men (27% vs 10.2%, respectively; p=0.003) but was similar in women and men prevalence of the BRAF V600E mutation according to sex (78% in women and 70% in men, p=0.9). The prevalence of dMMR in CRC is high in patients over 75. In elderly patients, dMMR tumours are significantly more frequent in women than in men. The BRAF mutation is frequent in elderly patients with CRC. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Quantifying the contributions of base selectivity, proofreading and mismatch repair to nuclear DNA replication in Saccharomyces cerevisiae.

    Science.gov (United States)

    St Charles, Jordan A; Liberti, Sascha E; Williams, Jessica S; Lujan, Scott A; Kunkel, Thomas A

    2015-07-01

    Mismatches generated during eukaryotic nuclear DNA replication are removed by two evolutionarily conserved error correction mechanisms acting in series, proofreading and mismatch repair (MMR). Defects in both processes are associated with increased susceptibility to cancer. To better understand these processes, we have quantified base selectivity, proofreading and MMR during nuclear DNA replication in Saccharomyces cerevisiae. In the absence of proofreading and MMR, the primary leading and lagging strand replicases, polymerase ɛ and polymerase δ respectively, synthesize DNA in vivo with somewhat different error rates and specificity, and with apparent base selectivity that is more than 100 times higher than measured in vitro. Moreover, leading and lagging strand replication fidelity rely on a different balance between proofreading and MMR. On average, proofreading contributes more to replication fidelity than does MMR, but their relative contributions vary from nearly all proofreading of some mismatches to mostly MMR of other mismatches. Thus accurate replication of the two DNA strands results from a non-uniform and variable balance between error prevention, proofreading and MMR.

  4. Marked increase in biofilm-derived rough pneumococcal variants and rifampin-resistant strains not due to hex gene mutations.

    Science.gov (United States)

    McEllistrem, M Catherine; Scott, Jennifer R; Zuniga-Castillo, Jacobo; Khan, Saleem A

    2009-06-01

    Otitis, pneumonia, and meningitis are tissue-based pneumococcal infections that can be associated with biofilms. The emergence of phenotypic rough variants, also known as acapsular small-colony variants, is essential for pneumococcal biofilm formation. These rough variants can increase nearly 100-fold in biofilms over time and can arise through single nucleotide polymorphisms (SNPs), deletions, or tandem duplications in the first gene of the capsular operon, cps3D. We detected a 100-fold increase in rifampin-resistant (Rif(r)) mutants in biofilms compared to planktonic cultures using a nonvaccine serotype 3 strain, which is causing an increasing number of cases of otitis in the 7-valent pneumococcal conjugate vaccine era. Since both rough variants and Rif(r) strains can arise through SNPs, they could emerge due to alteration of the mismatch repair (MMR) system. The Hex system, a pneumococcal MMR system, repairs mismatches during replication and transformation. In this study, no mutations were detected in the hexAB gene sequences among several rough variants with unique mutations in the cps3D gene. Within a hexA null mutant grown in broth, we detected only a 17.5-fold increase in rough variants compared to the wild-type parental strain. Taken together, these data suggest that mutations in the hex genes and modulation of hexA activity are unlikely to account for the generation of biofilm-derived rough variants.

  5. Beryllium chloride-induced oxidative DNA damage and alteration in the expression patterns of DNA repair-related genes.

    Science.gov (United States)

    Attia, Sabry M; Harisa, Gamaleldin I; Hassan, Memy H; Bakheet, Saleh A

    2013-09-01

    Beryllium metal has physical properties that make its use essential for very specific applications, such as medical diagnostics, nuclear/fusion reactors and aerospace applications. Because of the widespread human exposure to beryllium metals and the discrepancy of the genotoxic results in the reported literature, detail assessments of the genetic damage of beryllium are warranted. Mice exposed to beryllium chloride at an oral dose of 23mg/kg for seven consecutive days exhibited a significant increase in the level of DNA-strand breaking and micronuclei formation as detected by a bone marrow standard comet assay and micronucleus test. Whereas slight beryllium chloride-induced oxidative DNA damage was detected following formamidopyrimidine DNA glycosylase digestion, digestion with endonuclease III resulted in considerable increases in oxidative DNA damage after the 11.5 and 23mg/kg/day treatment as detected by enzyme-modified comet assays. Increased 8-hydroxydeoxyguanosine was also directly correlated with increased bone marrow micronuclei formation and DNA strand breaks, which further confirm the involvement of oxidative stress in the induction of bone marrow genetic damage after exposure to beryllium chloride. Gene expression analysis on the bone marrow cells from beryllium chloride-exposed mice showed significant alterations in genes associated with DNA damage repair. Therefore, beryllium chloride may cause genetic damage to bone marrow cells due to the oxidative stress and the induced unrepaired DNA damage is probably due to the down-regulation in the expression of DNA repair genes, which may lead to genotoxicity and eventually cause carcinogenicity.

  6. DNA repair gene XRCC3 241Met variant and breast cancer susceptibility of Azeri population in Iranian

    Directory of Open Access Journals (Sweden)

    Gohari-Lasaki Sahar

    2015-01-01

    Full Text Available DNA-repair systems are essential for repairing damage that occurs when there is recombination between homologous chromosomes. The gene XRCC3 (X-ray cross complementing group 3 encodes a member of the RecA/Rad51-related protein family that participates in homologous recombination to maintain chromosome stability and repair DNA damage. The Thr241Met XRCC3-18067C>T, rs861539 substitution, a C to T transition at codon 241 in exon7, thus plays critical roles in cancer development. The aim of this study was association between XRCC3 Thr241Met polymorphism and risk of sporadic breast cancer in Azari population. We analysed DNA samples from 100 sporadic breast cancer patients and 100 healthy women, for XRCC3 Thr241Met polymorphism using PCR-RFLP. Genotype specific risks were tested using chi-test with 95% confident intervals. Frequency of Thr/Thr at codon 241was 69% in controls and 70% in patients, Thr/Met frequency was 22% in controls and 13 % in patients, the Met/Met genotype was 9% incontrols and 17% in patients. No correlation between the genotype and allele distribution and increased susceptibility for breast Cancer. Our results suggested that in pre-menopausal women, breast cancer riskis not significantly associated with rs861539 in Azari population.

  7. Similar immunogenicity of measles-mumps-rubella (MMR) vaccine administrated at 8 months versus 12 months age in children.

    Science.gov (United States)

    He, Hanqing; Chen, Enfu; Chen, Haiping; Wang, Zhifang; Li, Qian; Yan, Rui; Guo, Jing; Zhou, Yang; Pan, Jinren; Xie, Shuyun

    2014-06-30

    Two doses of measles-mumps-rubella (MMR) strategy has been recommended by World Health Organization and is also widely adopted in many countries. In order to provide the evidence for perfecting the immunization strategy of MMR, this study evaluated the safety and immunogenicity of MMR with different two-dose schedule in infants. 280 participants were enrolled and randomly allocated to Group 1 (first dose at 8 months) or Group 2 (first dose at 12 months), and both groups administered the second dose at 10 months later. Solicited local and general symptoms after each vaccination with MMR were mild and infrequent in all participants of two groups. After administration of the first dose of MMR, seropositive rates were 100% in both groups for measles, 89.3% in Group 1 and 87.1% in Group 2 for mumps (P=0.578), 92.0% in Group 1 and 92.9% in Group 2 (P=0.393). The seropositive rates of mumps decreased significantly (from >86% to measles and rubella. All children get the positive titer for three vaccines in two groups after given the second dose MMR, higher seroconversion rate was found for mumps both in two groups (71.7% vs 77.2%, P=0.370). In conclusion, this study indicated that the MMR was well tolerated and immunogenic against measles, mumps and rubella with schedule of first dose both at 8 months and 12 months age. Our findings strongly supported that two doses of MMR can be introduced by replacing the first dose of MR in current EPI with MMR at 8 months age and the second dose at 18 months in China.

  8. Association between perfluoroalkyl substance exposure and asthma and allergic disease in children as modified by MMR vaccination.

    Science.gov (United States)

    Timmermann, Clara Amalie Gade; Budtz-Jørgensen, Esben; Jensen, Tina Kold; Osuna, Christa Elyse; Petersen, Maria Skaalum; Steuerwald, Ulrike; Nielsen, Flemming; Poulsen, Lars K; Weihe, Pál; Grandjean, Philippe

    2017-12-01

    Perfluoroalkyl substances (PFASs) are highly persistent chemicals that might be associated with asthma and allergy, but the associations remain unclear. Therefore, this study examined whether pre- and postnatal PFAS exposure was associated with childhood asthma and allergy. Measles, mumps, and rubella (MMR) vaccination in early life may have a protective effect against asthma and allergy, and MMR vaccination is therefore taken into account when evaluating these associations. In a cohort of Faroese children whose mothers were recruited during pregnancy, serum concentrations of five PFASs - Perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) - were measured at three timepoints (maternal serum in pregnancy week 34-36 and child serum at ages 5 and 13 years) and their association with immunoglobulin E (IgE) (cord blood and at age 7 years) and asthma/allergic diseases (questionnaires at ages 5 and 13 years and skin prick test at age 13 years) was determined. A total of 559 children were included in the analyses. Interactions with MMR vaccination were evaluated. Among 22 MMR-unvaccinated children, higher levels of the five PFASs at age 5 years were associated with increased odds of asthma at ages 5 and 13. The associations were reversed among MMR-vaccinated children. Prenatal PFAS exposure was not associated with childhood asthma or allergic diseases regardless of MMR vaccination status. In conclusion, PFAS exposure at age 5 was associated with increased risk of asthma among a small subgroup of MMR-unvaccinated children but not among MMR-vaccinated children. While PFAS exposure may impact immune system functions, this study suggests that MMR vaccination might be a potential effect-modifier.

  9. Replication Stalling and Heteroduplex Formation within CAG/CTG Trinucleotide Repeats by Mismatch Repair

    KAUST Repository

    Viterbo, David

    2016-03-16

    Trinucleotide repeat expansions are responsible for at least two dozen neurological disorders. Mechanisms leading to these large expansions of repeated DNA are still poorly understood. It was proposed that transient stalling of the replication fork by the repeat tract might trigger slippage of the newly-synthesized strand over its template, leading to expansions or contractions of the triplet repeat. However, such mechanism was never formally proven. Here we show that replication fork pausing and CAG/CTG trinucleotide repeat instability are not linked, stable and unstable repeats exhibiting the same propensity to stall replication forks when integrated in a yeast natural chromosome. We found that replication fork stalling was dependent on the integrity of the mismatch-repair system, especially the Msh2p-Msh6p complex, suggesting that direct interaction of MMR proteins with secondary structures formed by trinucleotide repeats in vivo, triggers replication fork pauses. We also show by chromatin immunoprecipitation that Msh2p is enriched at trinucleotide repeat tracts, in both stable and unstable orientations, this enrichment being dependent on MSH3 and MSH6. Finally, we show that overexpressing MSH2 favors the formation of heteroduplex regions, leading to an increase in contractions and expansions of CAG/CTG repeat tracts during replication, these heteroduplexes being dependent on both MSH3 and MSH6. These heteroduplex regions were not detected when a mutant msh2-E768A gene in which the ATPase domain was mutated was overexpressed. Our results unravel two new roles for mismatch-repair proteins: stabilization of heteroduplex regions and transient blocking of replication forks passing through such repeats. Both roles may involve direct interactions between MMR proteins and secondary structures formed by trinucleotide repeat tracts, although indirect interactions may not be formally excluded.

  10. Lack of DNA mismatch repair protein MSH6 in the rat results in hereditary non-polyposis colorectal cancer-like tumorigenesis.

    NARCIS (Netherlands)

    van Boxtel, R.; Toonen, P.W.; van Roekel, H.S.; Verheul, M.; Smits, B.M.; Korving, J.; de Bruin, A.; Cuppen, E.

    2008-01-01

    To understand genetic instability in relation to tumorigenesis, experimental animal models have proven very useful. The DNA mismatch repair (MMR) machinery safeguards genomic integrity by repairing mismatches, insertion or deletion loops and responding to genotoxic agents. Here, we describe the func

  11. Antioxidative Dietary Compounds Modulate Gene Expression Associated with Apoptosis, DNA Repair, Inhibition of Cell Proliferation and Migration

    Directory of Open Access Journals (Sweden)

    Likui Wang

    2014-09-01

    Full Text Available Many dietary compounds are known to have health benefits owing to their antioxidative and anti-inflammatory properties. To determine the molecular mechanism of these food-derived compounds, we analyzed their effect on various genes related to cell apoptosis, DNA damage and repair, oxidation and inflammation using in vitro cell culture assays. This review further tests the hypothesis proposed previously that downstream products of COX-2 (cyclooxygenase-2 called electrophilic oxo-derivatives induce antioxidant responsive elements (ARE, which leads to cell proliferation under antioxidative conditions. Our findings support this hypothesis and show that cell proliferation was inhibited when COX-2 was down-regulated by polyphenols and polysaccharides. Flattened macrophage morphology was also observed following the induction of cytokine production by polysaccharides extracted from viili, a traditional Nordic fermented dairy product. Coix lacryma-jobi (coix polysaccharides were found to reduce mitochondrial membrane potential and induce caspase-3- and 9-mediated apoptosis. In contrast, polyphenols from blueberries were involved in the ultraviolet-activated p53/Gadd45/MDM2 DNA repair system by restoring the cell membrane potential. Inhibition of hypoxia-inducible factor-1 by saponin extracts of ginsenoside (Ginsen and Gynostemma and inhibition of S100A4 by coix polysaccharides inhibited cancer cell migration and invasion. These observations suggest that antioxidants and changes in cell membrane potential are the major driving forces that transfer signals through the cell membrane into the cytosol and nucleus, triggering gene expression, changes in cell proliferation and the induction of apoptosis or DNA repair.

  12. Association of obesity with DNA mismatch repair status and clinical outcome in patients with stage II or III colon carcinoma participating in NCCTG and NSABP adjuvant chemotherapy trials.

    Science.gov (United States)

    Sinicrope, Frank A; Foster, Nathan R; Yoon, Harry H; Smyrk, Thomas C; Kim, George P; Allegra, Carmen J; Yothers, Greg; Nikcevich, Daniel A; Sargent, Daniel J

    2012-02-01

    Although the importance of obesity in colon cancer risk and outcome is recognized, the association of body mass index (BMI) with DNA mismatch repair (MMR) status is unknown. BMI (kg/m(2)) was determined in patients with TNM stage II or III colon carcinomas (n = 2,693) who participated in randomized trials of adjuvant chemotherapy. The association of BMI with MMR status and survival was analyzed by logistic regression and Cox models, respectively. Overall, 427 (16%) tumors showed deficient MMR (dMMR), and 630 patients (23%) were obese (BMI ≥ 30 kg/m(2)). Obesity was significantly associated with younger age (P = .021), distal tumor site (P = .012), and a lower rate of dMMR tumors (10% v 17%; P Obesity remained associated with lower rates of dMMR (odds ratio, 0.57; 95% CI, 0.41 to 0.79; P obese patients, rates of dMMR were lower in men compared with women (8% v 13%; P = .041). Obesity was associated with higher recurrence rates (P = .0034) and independently predicted worse disease-free survival (DFS; hazard ratio [HR], 1.37; 95% CI, 1.14 to 1.64; P = .0010) and overall survival (OS), whereas dMMR predicted better DFS (HR, 0.59; 95% CI, 0.47 to 0.74; P obese patients. Colon cancers from obese patients are less likely to show dMMR, suggesting obesity-related differences in the pathogenesis of colon cancer. Although obesity was independently associated with adverse outcome, the favorable prognostic impact of dMMR was maintained among obese patients.

  13. DNA Mismatch Repair Interacts with CAF-1- and ASF1A-H3-H4-dependent Histone (H3-H4)2 Tetramer Deposition.

    Science.gov (United States)

    Rodriges Blanko, Elena; Kadyrova, Lyudmila Y; Kadyrov, Farid A

    2016-04-22

    DNA mismatch repair (MMR) is required for the maintenance of genome stability and protection of humans from several types of cancer. Human MMR occurs in the chromatin environment, but little is known about the interactions between MMR and the chromatin environment. Previous research has suggested that MMR coincides with replication-coupled assembly of the newly synthesized DNA into nucleosomes. The first step in replication-coupled nucleosome assembly is CAF-1-dependent histone (H3-H4)2 tetramer deposition, a process that involves ASF1A-H3-H4 complex. In this work we used reconstituted human systems to investigate interactions between MMR and CAF-1- and ASF1A-H3-H4-dependent histone (H3-H4)2 tetramer deposition. We have found that MutSα inhibits CAF-1- and ASF1A-H3-H4-dependent packaging of a DNA mismatch into a tetrasome. This finding supports the idea that MMR occurs before the DNA mismatch is packaged into the tetrasome. Our experiments have also revealed that CAF-1- and ASF1A-H3-H4-dependent deposition of the histone (H3-H4)2 tetramers does not interfere with MMR reactions. In addition, we have established that unnecessary degradation of the discontinuous strand that takes place in both DNA polymerase δ (Pol δ)- and DNA polymerase ϵ (Pol ϵ)-dependent MMR reactions is suppressed by CAF-1- and ASF1A-H3-H4-dependent deposition of the histone (H3-H4)2 tetramers. These data suggest that CAF-1- and ASF1A-H3-H4-dependent deposition of the histone (H3-H4)2 tetramers is compatible with MMR and protects the discontinuous daughter strand from unnecessary degradation by MMR machinery.

  14. The blame frame: media attribution of culpability about the MMR-autism vaccination scare.

    Science.gov (United States)

    Holton, Avery; Weberling, Brooke; Clarke, Christopher E; Smith, Michael J

    2012-01-01

    Scholars have examined how news media frame events, including responsibility for causing and fixing problems, and how these frames inform public judgment. This study analyzed 281 newspaper articles about a controversial medical study linking the measles, mumps, and rubella (MMR) vaccination with autism. Given criticism of the study and its potential negative impact on vaccination rates across multiple countries, the current study examined actors to whom news media attributed blame for the MMR-vaccine association, sources used to support those attributions, and what solutions (e.g., mobilizing information), if any, were offered. This study provides unique insight by examining the evolution of these attributions over the lifetime of the controversy. Findings emphasize how news media may attribute blame in health risk communication and how that ascription plays a potentially vital role in shaping public behavior. Theoretical and practical implications are discussed.

  15. SNPs in DNA repair or oxidative stress genes and late subcutaneous fibrosis in patients following single shot partial breast irradiation

    Directory of Open Access Journals (Sweden)

    Falvo Elisabetta

    2012-01-01

    Full Text Available Abstract Background The aim of this study was to evaluate the potential association between single nucleotide polymorphisms related response to radiotherapy injury, such as genes related to DNA repair or enzymes involved in anti-oxidative activities. The paper aims to identify marker genes able to predict an increased risk of late toxicity studying our group of patients who underwent a Single Shot 3D-CRT PBI (SSPBI after BCS (breast conserving surgery. Methods A total of 57 breast cancer patients who underwent SSPBI were genotyped for SNPs (single nucleotide polymorphisms in XRCC1, XRCC3, GST and RAD51 by Pyrosequencing technology. Univariate analysis (ORs and 95% CI was performed to correlate SNPs with the risk of developing ≥ G2 fibrosis or fat necrosis. Results A higher significant risk of developing ≥ G2 fibrosis or fat necrosis in patients with: polymorphic variant GSTP1 (Ile105Val (OR = 2.9; 95%CI, 0.88-10.14, p = 0.047. Conclusions The presence of some SNPs involved in DNA repair or response to oxidative stress seem to be able to predict late toxicity. Trial Registration ClinicalTrials.gov: NCT01316328

  16. Trichostatin A enhances vascular repair by injected human endothelial progenitors through increasing the expression of TAL1-dependent genes.

    Science.gov (United States)

    Palii, Carmen G; Vulesevic, Branka; Fraineau, Sylvain; Pranckeviciene, Erinija; Griffith, Alexander J; Chu, Alphonse; Faralli, Hervé; Li, Yuhua; McNeill, Brian; Sun, Jie; Perkins, Theodore J; Dilworth, F Jeffrey; Perez-Iratxeta, Carol; Suuronen, Erik J; Allan, David S; Brand, Marjorie

    2014-05-01

    A major goal of cell therapy for vascular diseases is to promote revascularization through the injection of endothelial stem/progenitor cells. The gene regulatory mechanisms that underlie endothelial progenitor-mediated vascular repair, however, remain elusive. Here, we identify the transcription factor TAL1/SCL as a key mediator of the vascular repair function of primary human endothelial colony-forming cells (ECFCs). Genome-wide analyses in ECFCs demonstrate that TAL1 activates a transcriptional program that promotes cell adhesion and migration. At the mechanistic level, we show that TAL1 upregulates the expression of migratory and adhesion genes through recruitment of the histone acetyltransferase p300. Based on these findings, we establish a strategy that enhances the revascularization efficiency of ECFCs after ischemia through ex vivo priming with the histone deacetylase inhibitor TSA. Thus, small molecule epigenetics drugs are effective tools for modifying the epigenome of stem/progenitor cells prior to transplantation as a means to enhance their therapeutic potential.

  17. Three-dimensionally Specific Inhibition of DNA Repair-Related Genes by Activated KRAS in Colon Crypt Model

    Directory of Open Access Journals (Sweden)

    Toshiyuki Tsunoda

    2010-05-01

    Full Text Available Growth and differentiation of colonic epithelium are regulated in the three-dimensional (3D physiological architecture, colonic crypt, and deregulation of 3D interactions is involved in tumorigenesis. Cell-based 3D culture systems provide a suitable approach bridging the gap between two-dimensional (2D culture and animal models. KRAS mutations are found at high frequencies in human colorectal cancer (CRC; however, KRAS-targeted cancer therapy has not been developed. Here, we have established a 3D cell culture model resembling the colonic crypt by use of HKe3 cells, human CRC HCT116 cells disrupted at activated KRAS. In this 3D colonic crypt model, HKe3 cells showed the features of time course-dependent transit-amplifying and terminal-differentiated stages, which are characteristic of normal colonic crypt. On the basis of the features of HCT116 cells, activated KRAS inhibited normal cell polarity and apoptosis in 3D culture. The expression of DNA repair-related tumor suppressor genes including TP53, BRCA1, BRCA2, and EXO-1 was markedly suppressed by activated KRAS in 3D culture but not in 2D culture. These results together suggest that activated KRAS plays critical roles in the accumulation of genetic alterations through inhibition of DNA repair genes and apoptosis and that this 3D culture model will provide a useful tool for investigating the molecular mechanisms of CRC development.

  18. Regulated expression of the Saccharomyces cerevisiae DNA repair gene RAD7 in response to DNA damage and during sporulation.

    Science.gov (United States)

    Jones, J S; Prakash, L; Prakash, S

    1990-06-11

    The RAD7 gene of Saccharomyces cerevisiae affects the proficiency of excision repair of DNA damaged by UV light. Here, we report our studies on the regulation of the RAD7 gene in response to UV irradiation and during sporulation. RAD7 transcript levels increased 6-fold within 40 min of exposure of cells to 37 J/m2 of UV light. Higher UV doses also elicited rapid increases in the level of RAD7 mRNA. RAD7 mRNA levels increased in sporulating MATa/MAT alpha diploid cells, but not in the asporogenous MATa/MATa strain exposed to sporulation conditions. The increase in RAD7 mRNA level in MATa/MAT alpha cells was 15-fold after 6 h and 9-fold after 7 h in sporulation medium; thereafter, RAD7 mRNA levels declined. Periodic transcription of RAD7 during sporulation suggests a role for RAD7 in this process.

  19. What are parents' perspectives on psychological empowerment in the MMR vaccination decision? A focus group study

    OpenAIRE

    Fadda, Marta; Galimberti, Elisa; Carraro, Valter; Peter J Schulz

    2016-01-01

    Objectives Most developed countries do not have compulsory immunisation requirements, but instead issue recommendations. Although parents are expected to make an informed, autonomous (ie, empowered) decision regarding their children's vaccinations, there is no evidence about how parents' interpret this demand nor on the latitude of their decision-making. The goal of this study is to gain insights from parents residing in a low measles-mumps-rubella (MMR) uptake area on what constitutes feelin...

  20. Measles, the media, and MMR: Impact of the 2014-15 measles outbreak.

    Science.gov (United States)

    Cataldi, Jessica R; Dempsey, Amanda F; O'Leary, Sean T

    2016-12-07

    In late 2014, a measles outbreak beginning in California received significant media attention. To better understand the impact of this outbreak, we conducted a survey to assess and compare among vaccine hesitant and non-hesitant new mothers how this outbreak affected vaccine knowledge, attitudes, vaccination plans, and media use. A cross-sectional email survey of English-speaking women with a child ⩽1year old using a convenience sample of women from nine obstetrics and gynecology (OB/GYN) practices in Colorado assessed vaccine hesitancy, knowledge and attitudes about MMR vaccines and the outbreak, MMR vaccination plans before and after the outbreak, and use of and trust for media sources related to the outbreak. The response rate was 50% (351/701). Knowledge about the outbreak was high and vaccination attitudes were mostly favorable. Forty-eight percent of respondents thought MMR vaccine was more important after the outbreak. Online news (76%), television news (75%), and social media (68%) were the most frequently used media sources, yet were highly trusted by only 18%, 22%, and 1% of respondents respectively. Government websites (34%) and information from a doctor's office (34%) were infrequently used, but were highly trusted by 62% and 60% of respondents. Knowledge of the outbreak was lower among vaccine-hesitant respondents. Few mothers changed MMR vaccination plans after the outbreak. New mothers had high levels of knowledge and favorable attitudes about vaccination after the 2014-15 measles outbreak. Media sources used the most are not the most trusted. Communication about outbreaks of vaccine-preventable diseases should include spread of accurate information to new media sources and strengthening of existing trust in traditional media. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. The role of mismatch repair in small-cell lung cancer cells

    DEFF Research Database (Denmark)

    Hansen, L T; Thykjaer, T; Ørntoft, T F

    2003-01-01

    . Surprisingly, MSI was not detected in 86MI and it appears to express all the major MMR components hMSH2, hMSH6, hMLH1, hPMS2, hMSH3, hMLH3, MBD4 (MED1) and hExo1. These data are consistent with at least two possibilities: (1) A missense mutation in one of the MMR genes, which dissociates MSI from drug...

  2. CDX2 downregulation is associated with poor differentiation and MMR deficiency in colon cancer

    DEFF Research Database (Denmark)

    Olsen, J.; Eiholm, Susanne; Kirkeby, L T

    2016-01-01

    , and migration. In this study, we investigated CDX2 mRNA and protein expression in relation to the clinicopathological characteristics of colon cancer, including mismatch repair status and recurrence risk. METHODS: Tumor samples were obtained from colon cancer patients. Biopsies from tumor tissue and normal......BACKGROUND: Homeobox genes are often deregulated in cancer and can have both oncogenic and tumor-suppressing potential. The Caudal-related homeobox transcription factor 2 (CDX2) is an intestine-specific transcription factor. CDX2 has been implicated in differentiation, proliferation, cell adhesion...

  3. Association between perfluoroalkyl substance exposure and asthma and allergic disease in children as modified by MMR vaccination

    DEFF Research Database (Denmark)

    Timmermann, Clara Amalie Gade; Budtz-Jørgensen, Esben; Jensen, Tina Kold

    2017-01-01

    , and rubella (MMR) vaccination in early life may have a protective effect against asthma and allergy, and MMR vaccination is therefore taken into account when evaluating these associations. In a cohort of Faroese children whose mothers were recruited during pregnancy, serum concentrations of five PFASs...... – Perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) – were measured at three timepoints (maternal serum in pregnancy week 34–36 and child serum at ages 5 and 13 years) and their association...... with immunoglobulin E (IgE) (cord blood and at age 7 years) and asthma/allergic diseases (questionnaires at ages 5 and 13 years and skin prick test at age 13 years) was determined. A total of 559 children were included in the analyses. Interactions with MMR vaccination were evaluated. Among 22 MMR...

  4. Association between perfluoroalkyl substance exposure and asthma and allergic disease in children as modified by MMR vaccination

    DEFF Research Database (Denmark)

    Timmermann, Clara Amalie Gade; Budtz-Jørgensen, Esben; Jensen, Tina Kold

    2017-01-01

    , and rubella (MMR) vaccination in early life may have a protective effect against asthma and allergy, and MMR vaccination is therefore taken into account when evaluating these associations. In a cohort of Faroese children whose mothers were recruited during pregnancy, serum concentrations of five PFASs...... - Perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) - were measured at three timepoints (maternal serum in pregnancy week 34-36 and child serum at ages 5 and 13 years) and their association...... with immunoglobulin E (IgE) (cord blood and at age 7 years) and asthma/allergic diseases (questionnaires at ages 5 and 13 years and skin prick test at age 13 years) was determined. A total of 559 children were included in the analyses. Interactions with MMR vaccination were evaluated. Among 22 MMR...

  5. [Lack of association between MMR vaccination and the incidence of autism in children: a case-control study].

    Science.gov (United States)

    Mrozek-Budzyn, Dorota; Kiełtyka, Agnieszka; Majewska, Renata

    2009-01-01

    The matched case-control study has been undertook to investigate whether measles, mumps, and rubella (MMR) vaccine may be casually associated with autism in children. Cases were children to 14-year old with diagnosis of core autism or atypical autism. Controls were matched on age, sex and general practice. The 96 cases and 192 controls were included. The study provides strong evidence against association of autism with both MMR and a single measles individual vaccine. Additionally children vaccinated with MMR, regardless of age of vaccination (to 18th, 24th and 36th month of life), had risk equal half of that of single measles vaccinated (for vaccinated to 18th month OR=0.41 95%PU: 0.20-0.85). Our findings confirm that MMR vaccination is not associated with an increased risk of autism in children.

  6. The GH/IGF-1 axis in a critical period early in life determines cellular DNA repair capacity by altering transcriptional regulation of DNA repair-related genes: implications for the developmental origins of cancer.

    Science.gov (United States)

    Podlutsky, Andrej; Valcarcel-Ares, Marta Noa; Yancey, Krysta; Podlutskaya, Viktorija; Nagykaldi, Eszter; Gautam, Tripti; Miller, Richard A; Sonntag, William E; Csiszar, Anna; Ungvari, Zoltan

    2017-02-23

    Experimental, clinical, and epidemiological findings support the concept of developmental origins of health and disease (DOHAD), suggesting that early-life hormonal influences during a sensitive period around adolescence have a powerful impact on cancer morbidity later in life. The endocrine changes that occur during puberty are highly conserved across mammalian species and include dramatic increases in circulating GH and IGF-1 levels. Importantly, patients with developmental IGF-1 deficiency due to GH insensitivity (Laron syndrome) do not develop cancer during aging. Rodents with developmental GH/IGF-1 deficiency also exhibit significantly decreased cancer incidence at old age, marked resistance to chemically induced carcinogenesis, and cellular resistance to genotoxic stressors. Early-life treatment of GH/IGF-1-deficient mice and rats with GH reverses the cancer resistance phenotype; however, the underlying molecular mechanisms remain elusive. The present study was designed to test the hypothesis that developmental GH/IGF-1 status impacts cellular DNA repair mechanisms. To achieve that goal, we assessed repair of γ-irradiation-induced DNA damage (single-cell gel electrophoresis/comet assay) and basal and post-irradiation expression of DNA repair-related genes (qPCR) in primary fibroblasts derived from control rats, Lewis dwarf rats (a model of developmental GH/IGF-1 deficiency), and GH-replete dwarf rats (GH administered beginning at 5 weeks of age, for 30 days). We found that developmental GH/IGF-1 deficiency resulted in persisting increases in cellular DNA repair capacity and upregulation of several DNA repair-related genes (e.g., Gadd45a, Bbc3). Peripubertal GH treatment reversed the radiation resistance phenotype. Fibroblasts of GH/IGF-1-deficient Snell dwarf mice also exhibited improved DNA repair capacity, showing that the persisting influence of peripubertal GH/IGF-1 status is not species-dependent. Collectively, GH/IGF-1 levels during a critical period

  7. Intralesional tuberculin (PPD) versus measles, mumps, rubella (MMR) vaccine in treatment of multiple warts: a comparative clinical and immunological study.

    Science.gov (United States)

    Shaheen, Maha Adel; Salem, Samar Abdallah M; Fouad, Dina Adel; El-Fatah, Abeer Aly Abd

    2015-01-01

    Intralesional purified protein derivative (PPD) or mumps, measles, rubella (MMR) were not previously compared regarding their efficacy or mechanism of action in treatment of warts. We aimed to compare their efficacy in treatment of multiple warts and investigate their effect on serum interleukin (IL)-4 and IL-12. Thirty patients with multiple warts were included (10 treated with PPD, 10 with MMR, and 10 with normal saline (control)). Injection was done every 3 weeks until clearance or maximum of three treatments. Clinical response of target and distant warts was evaluated. Serum ILs-4 and -12 were assessed before and after treatment. A significantly higher rate of complete response was found in target and distant warts with PPD (60% each) and MMR (80%, 40%, respectively) compared with controls (0%), with no significant difference between both treatments. After treatment, the control group showed the lowest serum IL-12 and IL-4 levels compared with the MMR- and PPD-treated groups with statistically significant difference in between. MMR resulted in a significantly higher serum IL-12 than PPD. With PPD, IL-4 was increased with statistically significant change compared with pretreat-ment level. Intralesional PPD and MMR show comparable efficacy and safety in treatment of multiple warts. Serum ILs-4 and-12 increase following antigen injection. © 2015 Wiley Periodicals, Inc.

  8. Strategies for psbA gene expression in cyanobacteria, green algae and higher plants: from transcription to PSII repair.

    Science.gov (United States)

    Mulo, Paula; Sakurai, Isamu; Aro, Eva-Mari

    2012-01-01

    The Photosystem (PS) II of cyanobacteria, green algae and higher plants is prone to light-induced inactivation, the D1 protein being the primary target of such damage. As a consequence, the D1 protein, encoded by the psbA gene, is degraded and re-synthesized in a multistep process called PSII repair cycle. In cyanobacteria, a small gene family codes for the various, functionally distinct D1 isoforms. In these organisms, the regulation of the psbA gene expression occurs mainly at the level of transcription, but the expression is fine-tuned by regulation of translation elongation. In plants and green algae, the D1 protein is encoded by a single psbA gene located in the chloroplast genome. In chloroplasts of Chlamydomonas reinhardtii the psbA gene expression is strongly regulated by mRNA processing, and particularly at the level of translation initiation. In chloroplasts of higher plants, translation elongation is the prevalent mechanism for regulation of the psbA gene expression. The pre-existing pool of psbA transcripts forms translation initiation complexes in plant chloroplasts even in darkness, while the D1 synthesis can be completed only in the light. Replacement of damaged D1 protein requires also the assistance by a number of auxiliary proteins, which are encoded by the nuclear genome in green algae and higher plants. Nevertheless, many of these chaperones are conserved between prokaryotes and eukaryotes. Here, we describe the specific features and fundamental differences of the psbA gene expression and the regeneration of the PSII reaction center protein D1 in cyanobacteria, green algae and higher plants. This article is part of a Special Issue entitled Photosystem II.

  9. Prevalence and Spectrum of Germline Cancer Susceptibility Gene Mutations Among Patients With Early-Onset Colorectal Cancer.

    Science.gov (United States)

    Pearlman, Rachel; Frankel, Wendy L; Swanson, Benjamin; Zhao, Weiqiang; Yilmaz, Ahmet; Miller, Kristin; Bacher, Jason; Bigley, Christopher; Nelsen, Lori; Goodfellow, Paul J; Goldberg, Richard M; Paskett, Electra; Shields, Peter G; Freudenheim, Jo L; Stanich, Peter P; Lattimer, Ilene; Arnold, Mark; Liyanarachchi, Sandya; Kalady, Matthew; Heald, Brandie; Greenwood, Carla; Paquette, Ian; Prues, Marla; Draper, David J; Lindeman, Carolyn; Kuebler, J Philip; Reynolds, Kelly; Brell, Joanna M; Shaper, Amy A; Mahesh, Sameer; Buie, Nicole; Weeman, Kisa; Shine, Kristin; Haut, Mitchell; Edwards, Joan; Bastola, Shyamal; Wickham, Karen; Khanduja, Karamjit S; Zacks, Rosemary; Pritchard, Colin C; Shirts, Brian H; Jacobson, Angela; Allen, Brian; de la Chapelle, Albert; Hampel, Heather

    2017-04-01

    Hereditary cancer syndromes infer high cancer risks and require intensive cancer surveillance, yet the prevalence and spectrum of these conditions among unselected patients with early-onset colorectal cancer (CRC) is largely undetermined. To determine the frequency and spectrum of cancer susceptibility gene mutations among patients with early-onset CRC. Overall, 450 patients diagnosed with colorectal cancer younger than 50 years were prospectively accrued from 51 hospitals into the Ohio Colorectal Cancer Prevention Initiative from January 1, 2013, to June 20, 2016. Mismatch repair (MMR) deficiency was determined by microsatellite instability and/or immunohistochemistry. Germline DNA was tested for mutations in 25 cancer susceptibility genes using next-generation sequencing. Mutation prevalence and spectrum in patients with early-onset CRC was determined. Clinical characteristics were assessed by mutation status. In total 450 patients younger than 50 years were included in the study, and 75 gene mutations were found in 72 patients (16%). Forty-eight patients (10.7%) had MMR-deficient tumors, and 40 patients (83.3%) had at least 1 gene mutation: 37 had Lynch syndrome (13, MLH1 [including one with constitutional MLH1 methylation]; 16, MSH2; 1, MSH2/monoallelic MUTYH; 2, MSH6; 5, PMS2); 1 patient had the APC c.3920T>A, p.I1307K mutation and a PMS2 variant; 9 patients (18.8%) had double somatic MMR mutations (including 2 with germline biallelic MUTYH mutations); and 1 patient had somatic MLH1 methylation. Four hundred two patients (89.3%) had MMR-proficient tumors, and 32 patients (8%) had at least 1 gene mutation: 9 had mutations in high-penetrance CRC genes (5, APC; 1, APC/PMS2; 2, biallelic MUTYH; 1, SMAD4); 13 patients had mutations in high- or moderate-penetrance genes not traditionally associated with CRC (3, ATM; 1, ATM/CHEK2; 2, BRCA1; 4, BRCA2; 1, CDKN2A; 2, PALB2); 10 patients had mutations in low-penetrance CRC genes (3, APC c.3920T>A, p.I1307K; 7

  10. DNA repair genes implicated in triple negative familial non-BRCA1/2 breast cancer predisposition.

    Science.gov (United States)

    Ollier, Marie; Radosevic-Robin, Nina; Kwiatkowski, Fabrice; Ponelle, Flora; Viala, Sandrine; Privat, Maud; Uhrhammer, Nancy; Bernard-Gallon, Dominique; Penault-Llorca, Frédérique; Bignon, Yves-Jean; Bidet, Yannick

    2015-01-01

    Among breast cancers, 10 to 15% of cases would be due to hereditary risk. In these familial cases, mutations in BRCA1 and BRCA2 are found in only 15% to 20%, meaning that new susceptibility genes remain to be found. Triple-negative breast cancers represent 15% of all breast cancers, and are generally aggressive tumours without targeted therapies available. Our hypothesis is that some patients with triple negative breast cancer could share a genetic susceptibility different from other types of breast cancers. We screened 36 candidate genes, using pyrosequencing, in all the 50 triple negative breast cancer patients with familial history of cancer but no BRCA1 or BRCA2 mutation of a population of 3000 families who had consulted for a familial breast cancer between 2005 and 2013. Any mutations were also sequenced in available relatives of cases. Protein expression and loss of heterozygosity were explored in tumours. Seven deleterious mutations in 6 different genes (RAD51D, MRE11A, CHEK2, MLH1, MSH6, PALB2) were observed in one patient each, except the RAD51D mutation found in two cases. Loss of heterozygosity in the tumour was found for 2 of the 7 mutations. Protein expression was absent in tumour tissue for 5 mutations. Taking into consideration a specific subtype of tumour has revealed susceptibility genes, most of them in the homologous recombination DNA repair pathway. This may provide new possibilities for targeted therapies, along with better screening and care of patients.

  11. Polysaccharides of Aloe vera induce MMP-3 and TIMP-2 gene expression during the skin wound repair of rat.

    Science.gov (United States)

    Tabandeh, Mohammad Reza; Oryan, Ahmad; Mohammadalipour, Adel

    2014-04-01

    Polysaccharides are the main macromolecules of Aloe vera gel but no data about their effect on extracellular matrix (ECM) elements are available. Here, mannose rich Aloe vera polysaccharides (AVP) with molecular weight between 50 and 250 kDa were isolated and characterized. Open cutaneous wounds on the back of 45 rats (control and treated) were daily treated with 25mg (n=15) and 50 mg (n=15) AVP for 30 days. The levels of MMP-3 and TIMP-2 gene expression were analyzed using real time PCR. The levels of n-acetyl glucosamine (NAGA), n-acetyl galactosamine (NAGLA) and collagen contents were also measured using standard biochemical methods. Faster wound closure was observed at day 15 post wounding in AVP treated animals in comparison with untreated group. At day 10 post wounding, AVP inhibited MMP-3 gene expression, while afterwards MMP-3 gene expression was upregulated. AVP enhanced TIMP-2 gene expression, collagen, NAGLA and NAGA synthesis in relation to untreated wounds. Our results suggest that AVP has positive effects on the regulation of ECM factor synthesis, which open up new perspectives for the wound repair activity of Aloe vera polysaccharide at molecular level.

  12. Genomic structure and characterization of the Drosophila S3 ribosomal/DNA repair gene and mutant alleles.

    Science.gov (United States)

    Kelley, M R; Xu, Y; Wilson, D M; Deutsch, W A

    2000-03-01

    The Drosophila S3 protein is known to be associated with ribosomes, where it is thought to play a role in the initiation of protein translation. The S3 protein also contains a DNA repair activity, efficiently processing 8-oxoguanine residues in DNA via an N-glycosylase/apurinic-apyrimidinic (AP) lyase activity. The gene that encodes S3 has previously been localized to one of the Minute loci on chromosome 3 in Drosophila. This study focused on the genomic organization of S3 at M(3)95A, initial promoter characterization, and analysis of three mutant alleles at this locus. The S3 gene was found to be a single-copy gene 2 to 3 kb in length and containing a single intron. The upstream 1.6-kb region was analyzed for promoter activity, identifying a presumptive regulatory domain containing potential enhancer and suppressor elements. This finding is of interest, as the S3 gene is constitutively expressed throughout development and mRNA is most likely maternally inherited. Lastly, three Minute alleles from the same locus were sequenced and two alleles found to contain a 22-bp deletion in exon 2, resulting in a truncated S3 protein, although wildtype levels of S3 mRNA and protein were detected in the viable heterozygous Minute alleles, possibly reflecting dosage compensation.

  13. RAD25 (SSL2), the yeast homolog of the human xeroderma pigmentosum group B DNA repair gene, is essential for viability

    Energy Technology Data Exchange (ETDEWEB)

    Park, E.; Prakash, L. (Univ. of Rochester School of Medicine, NY (United States)); Guzder, S.N.; Prakash, S. (Univ. of Rochester, NY (United States)); Koken, M.H.M.; Jaspers-Dekker, I.; Weeda, G.; Hoeijmakers, H.J. (Erasmus Univ., Rotterdam (Netherlands))

    1992-12-01

    Xeroderma pigmentosum (XP) patients are extremely sensitive to ultraviolet (UV) light and suffer from a high incidence of skin cancers, due to a defect in nucleotide excision repair. The disease is genetically heterogeneous, and seven complementation groups, A-G, have been identified. Homologs of human excision repair genes ERCC1, XPDC/ERCC2, and XPAC have been identified in the yeast Saccharomyces cerevisiae. Since no homolog of human XPBC/ERCC3 existed among the known yeast genes, we cloned the yeast homolog by using XPBC cDNA as a hybridization probe. The yeast homolog, RAD25 (SSL2), encodes a protein of 843 amino acids (M[sub r] 95,356). The RAD25 (SSL2)- and XPCX-encoded proteins share 55% identical and 72% conserved amino acid residues, and the two proteins resemble one another in containing the conserved DNA helicase sequence motifs. A nonsense mutation at codon 799 that deletes the 45 C-terminal amino acid residues in RAD25 (SSL2) confers UV sensitivity. This mutation shows epistasis with genes in the excision repair group, whereas a synergistic increase in UN sensitivity occurs when it is combined with mutations in genes in other DNA repair pathways, indicating that RAD25 (SSL2) functions in excision repair but not in other repair pathways. We also show that RAD25 (SSL2) is an essential gene. A mutation of the Lys[sup 392] residue to arginine in the conserved Walker type A nucleotide-binding motif is lethal, suggesting an essential role of the putative RAD 25 (SSL2) ATPase/DNA helicase activity in viability. 40 refs., 3 figs., 1 tab.

  14. Low-level laser irradiation alters mRNA expression from genes involved in DNA repair and genomic stabilization in myoblasts

    Science.gov (United States)

    Trajano, L. A. S. N.; Sergio, L. P. S.; Silva, C. L.; Carvalho, L.; Mencalha, A. L.; Stumbo, A. C.; Fonseca, A. S.

    2016-07-01

    Low-level lasers are used for the treatment of diseases in soft and bone tissues, but few data are available regarding their effects on genomic stability. In this study, we investigated mRNA expression from genes involved in DNA repair and genomic stabilization in myoblasts exposed to low-level infrared laser. C2C12 myoblast cultures in different fetal bovine serum concentrations were exposed to low-level infrared laser (10, 35 and 70 J cm-2), and collected for the evaluation of DNA repair gene expression. Laser exposure increased gene expression related to base excision repair (8-oxoguanine DNA glycosylase and apurinic/apyrimidinic endonuclease 1), nucleotide excision repair (excision repair cross-complementation group 1 and xeroderma pigmentosum C protein) and genomic stabilization (ATM serine/threonine kinase and tumor protein p53) in normal and low fetal bovine serum concentrations. Results suggest that genomic stability could be part of a biostimulation effect of low-level laser therapy in injured muscles.

  15. Human longevity and variation in DNA damage response and repair: study of the contribution of sub-processes using competitive gene-set analysis.

    Science.gov (United States)

    Debrabant, Birgit; Soerensen, Mette; Flachsbart, Friederike; Dato, Serena; Mengel-From, Jonas; Stevnsner, Tinna; Bohr, Vilhelm A; Kruse, Torben A; Schreiber, Stefan; Nebel, Almut; Christensen, Kaare; Tan, Qihua; Christiansen, Lene

    2014-09-01

    DNA-damage response and repair are crucial to maintain genetic stability, and are consequently considered central to aging and longevity. Here, we investigate whether this pathway overall associates to longevity, and whether specific sub-processes are more strongly associated with longevity than others. Data were applied on 592 SNPs from 77 genes involved in nine sub-processes: DNA-damage response, base excision repair (BER), nucleotide excision repair, mismatch repair, non-homologous end-joining, homologous recombinational repair (HRR), RecQ helicase activities (RECQ), telomere functioning and mitochondrial DNA processes. The study population was 1089 long-lived and 736 middle-aged Danes. A self-contained set-based test of all SNPs displayed association with longevity (P-value=9.9 × 10(-5)), supporting that the overall pathway could affect longevity. Investigation of the nine sub-processes using the competitive gene-set analysis by Wang et al indicated that BER, HRR and RECQ associated stronger with longevity than the respective remaining genes of the pathway (P-values=0.004-0.048). For HRR and RECQ, only one gene contributed to the significance, whereas for BER several genes contributed. These associations did, however, generally not pass correction for multiple testing. Still, these findings indicate that, of the entire pathway, variation in BER might influence longevity the most. These modest sized P-values were not replicated in a German sample. This might, though, be due to differences in genotyping procedures and investigated SNPs, potentially inducing differences in the coverage of gene regions. Specifically, five genes were not covered at all in the German data. Therefore, investigations in additional study populations are needed before final conclusion can be drawn.

  16. Many amino acid substitution variants identified in DNA repair genes during human population screenings are predicted to impact protein function

    Energy Technology Data Exchange (ETDEWEB)

    Xi, T; Jones, I M; Mohrenweiser, H W

    2003-11-03

    Over 520 different amino acid substitution variants have been previously identified in the systematic screening of 91 human DNA repair genes for sequence variation. Two algorithms were employed to predict the impact of these amino acid substitutions on protein activity. Sorting Intolerant From Tolerant (SIFT) classified 226 of 508 variants (44%) as ''Intolerant''. Polymorphism Phenotyping (PolyPhen) classed 165 of 489 amino acid substitutions (34%) as ''Probably or Possibly Damaging''. Another 9-15% of the variants were classed as ''Potentially Intolerant or Damaging''. The results from the two algorithms are highly associated, with concordance in predicted impact observed for {approx}62% of the variants. Twenty one to thirty one percent of the variant proteins are predicted to exhibit reduced activity by both algorithms. These variants occur at slightly lower individual allele frequency than do the variants classified as ''Tolerant'' or ''Benign''. Both algorithms correctly predicted the impact of 26 functionally characterized amino acid substitutions in the APE1 protein on biochemical activity, with one exception. It is concluded that a substantial fraction of the missense variants observed in the general human population are functionally relevant. These variants are expected to be the molecular genetic and biochemical basis for the associations of reduced DNA repair capacity phenotypes with elevated cancer risk.

  17. Associations of polymorphisms in DNA repair genes and MDR1 gene with chemotherapy response and survival of non-small cell lung cancer.

    Directory of Open Access Journals (Sweden)

    Yan Du

    Full Text Available OBJECTIVES: We aimed to determine the associations of genetic polymorphisms of excision repair cross-complementation group 1 (ERCC1 rs11615, xeroderma pigmentosum group D (XPD/ERCC2 rs13181, X-ray repair cross complementing group 1 (XRCC1 rs25487, XRCC3 rs1799794, and breast cancer susceptibility gene 1 (BRCA1 rs1799966 from the DNA repair pathway and multiple drug resistance 1 (MDR1/ABCB1 rs1045642 with response to chemotherapy and survival of non-small cell lung cancer (NSCLC in a Chinese population. MATERIALS AND METHODS: A total of 352 NSCLC patients were enrolled to evaluate the associations of the six SNPs with response to chemotherapy and overall survival. Logistic regressions were applied to test the associations of genetic polymorphisms with response to chemotherapy in 161 advanced NSCLC patients. Overall survival was analyzed in 161 advanced and 156 early stage NSCLC patients using the Kaplan-Meier method with log-rank test, respectively. Multivariate Cox proportional hazards model was performed to determine the factors independently associated with NSCLC prognosis. RESULTS: BRCA1 rs1799966 minor allele C (TC+CC vs. TT, OR = 0.402, 95% CI = 0.204-0.794, p = 0.008 and MDR1/ABCB1 rs1045642 minor allele A (GA +AA vs. GG, OR = 0.478, 95% CI = 0.244-0.934, p = 0.030 were associated with a better response to chemotherapy in advanced NSCLC patients. Survival analyses indicated that BRCA1 rs1799966 TC+CC genotypes were associated with a decreased risk of death (HR = 0.617, 95% CI = 0.402-0.948, p = 0.028 in advanced NSCLC patients, and the association was still significant after the adjustment for covariates. Multivariate Cox regression analysis showed that ERCC1 rs11615 AA genotype (P = 0.020 and smoking (p = 0.037 were associated with increased risks of death in early stage NSCLC patients after surgery. CONCLUSIONS: Polymorphisms of genes in DNA repair pathway and MDR1 could contribute to chemotherapy response and survival of patients with

  18. Intergenerational and striatal CAG repeat instability in Huntington's disease knock-in mice involve different DNA repair genes.

    Science.gov (United States)

    Dragileva, Ella; Hendricks, Audrey; Teed, Allison; Gillis, Tammy; Lopez, Edith T; Friedberg, Errol C; Kucherlapati, Raju; Edelmann, Winfried; Lunetta, Kathryn L; MacDonald, Marcy E; Wheeler, Vanessa C

    2009-01-01

    Modifying the length of the Huntington's disease (HD) CAG repeat, the major determinant of age of disease onset, is an attractive therapeutic approach. To explore this we are investigating mechanisms of intergenerational and somatic HD CAG repeat instability. Here, we have crossed HD CAG knock-in mice onto backgrounds deficient in mismatch repair genes, Msh3 and Msh6, to discern the effects on CAG repeat size and disease pathogenesis. We find that different mechanisms predominate in inherited and somatic instability, with Msh6 protecting against intergenerational contractions and Msh3 required both for increasing CAG length and for enhancing an early disease phenotype in striatum. Therefore, attempts to decrease inherited repeat size may entail a full understanding of Msh6 complexes, while attempts to block the age-dependent increases in CAG size in striatal neurons and to slow the disease process will require a full elucidation of Msh3 complexes and their function in CAG repeat instability.

  19. Deproteinized bone with VEGF gene transfer to facilitate the repair of early avascular necrosis of femoral head of rabbit

    Institute of Scientific and Technical Information of China (English)

    CAO Kai; HUANG Wei; AN Hong; JIANG Dian-ming; SHU Yong; HAN Zhi-min

    2009-01-01

    Objective: To explore a new method for early avascular necrosis of femoral head (AVNFH) therapy.Methods: Sixty-nine AVNFH New Zealand adult rabbits were randomly divided into three groups with equal number. In Group A, deproteinized bone (DPB) that absorbed with recombinant plasmid pcDNA3.1-hVEGF165 was implanted into the drilled tunnel of necrotic femoral head. In Group B, only DPB was implanted. In Group C, only tunnel was drilled without DPB or plasmid implanted. Femoral head specimens were obtained at postoperative 1, 2, 4, 8, 16 weeks. The expression of VEGF165 and collagen I was detected by immunohistochemistry. Bone formation was detected generally by X-ray. Angiogenesis and the repair of the femoral head were observed histologically.Results: The expression of VEGF 165 could be detected 2 weeks after implantation in Group A, but it was not observed in other groups. The result of collagen I expression had a significantly difference 2, 4 and 8 weeks after operation in Group A from those in other groups (P<0.01).X-ray results indicated that there was more bone formation in Group A than in other groups. The regenerated capillary vessels staining result of necrotic femoral head in Group A was significantly different from those in other groups at postoperative 2 and 4 weeks (P<0.01).Conclusions: Transfection ofhVEGF165 gene enhances local angiogenesis and DPB-VEGF compound improves the repair of necrotic femoral head. Deproteinized bone grafting with VEGF gene transfer provides a potential method for the treatment of osteonecrosis.

  20. Sequence and stress-response analyses of the DNA mismatch repair gene hexA in Lactococcus lactis.

    Science.gov (United States)

    Ren, J; Park, J H; Dunn, N W; Kim, W S

    2001-10-01

    The DNA mismatch repair gene hexA was identified in Lactococcus lactis by PCR amplification by using a pair of primers homologous to the DNA-binding Dps protein. The gene in its entirety, including the regulatory regions, was sequenced, by using a strategy of chromosomal walking based on two PCR protocols. The open reading frame of 2526 bp was preceded by a strong ribosome-binding site (AGGAAG) and was followed by a potential transcription terminator (hairpin loop structure). The 5' terminus of the hexA mRNA was located 135 bp upstream of the start codon, and putative -10 and -35 regions were identified. The deduced amino acid sequence revealed two motifs, the ATP/GTP-binding site (P-loop) and the "MutS family signature". The hexA promoter was cloned into pMU1327, which contained a promoter-less CAT reporter gene, and the promoter activity was examined under oxidative-stress conditions. It appears that the promoter activity is down-shifted by H2O2 at 4 mM.

  1. Frequent mutations of the CA simple sequence repeat in intron 1 of EGFR in mismatch repair-deficient colorectal cancers

    Institute of Scientific and Technical Information of China (English)

    Marie-Pierre Buisine; Thècla Lesuffleur; Agnès Wacrenier; Christophe Mariette; Emmanuelle Leteurtre; Fabienne Escande; Sana Aissi; Amandine Ketele; Annette Leclercq; Nicole Porchet

    2008-01-01

    AIM:To investigate the polymorphic simple sequence repeat in intron 1 of the epidermal growth factor receptor gene(EGFR)(CA-SSR I),which is known to affect the efficiency of gene transcription as a putative target of the mismatch repair (MMR) machinery in colorectal tumors.METHODS:The CA-SSR I genotype was analyzed in a total of 86 primary colorectal tumors,selected upon their microsatellite instability (MSI) status [42 with high frequency MSI (MSI-H) and 44 microsatellite stable (MSS)]and their respective normal tissue.The effect of the CASSR I genotype on the expression of the EGFR gene was evaluated in 18 specimens using quantitative real-time reverse transcription PCR and immunohistochemistry.RESULTS:Mutations in CA-SSR I were detected in 86%(36 of 42) of MSI-H colorectal tumors and 0% (0 of 44) of MSS tumors,indicating the EGFR gene as a novel putative specific target of the defective MMR system (P<0.001).Impaired expression of EGFR was detected in most of the colorectal tumors analyzed [6/12 (50%) at the mRNA level and 15/18 (83%) at the peptide level].However,no association was apparent between EGFR expression and CA-SSR I status in tumors or normal tissues.CONCLUSION:Our results suggest that CA-SSR I sequence does not contribute to the regulation of EGFR transcription in colon,and should thus not be considered as a promising predictive marker for response to EGFR inhibitors in patients with colorectal cancer.

  2. Ultraviolet B retards growth, induces oxidative stress, and modulates DNA repair-related gene and heat shock protein gene expression in the monogonont rotifer, Brachionus sp

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ryeo-Ok [Department of Chemistry, and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Rhee, Jae-Sung [Department of Molecular and Environmental Bioscience, Graduate School, Hanyang University, Seoul 133-791 (Korea, Republic of); Won, Eun-Ji [Department of Environmental Marine Sciences, College of Science and Technology, Hanyang University, Ansan 426-791 (Korea, Republic of); Lee, Kyun-Woo [Department of Chemistry, and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Kang, Chang-Mo [Laboratory of Cytogenetics and Tissue Regeneration, Korea Institute of Radiological and Medical Science, Seoul 139-709 (Korea, Republic of); Lee, Young-Mi [Department of Green Life Science, College of Convergence, Sangmyung University, Seoul 110-743 (Korea, Republic of); Lee, Jae-Seong, E-mail: jslee2@hanyang.ac.kr [Department of Chemistry, and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Department of Molecular and Environmental Bioscience, Graduate School, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2011-02-15

    Ultraviolet B (UV-B) radiation causes direct cellular damage by breakage of DNA strands and oxidative stress induction in aquatic organisms. To understand the effect of UV-B radiation on the rotifer, Brachionus sp., several parameters including 24-h survival rate, population growth rate, and ROS level were measured after exposure to a wide range of UV-B doses. To check the expression of other important inducible genes such as replication protein A (RPA), DNA-dependent protein kinase (DNA-PK), Ku70, Ku80, and heat shock proteins (hsps) after UV-B radiation, we observed dose- and time-dependency at 2 kJ/m{sup 2}. We also examined 13 hsp genes for their roles in the UV-B damaged rotifer. Results showed that UV-B remarkably inhibited the population growth of Brachionus sp. The level of intracellular reactive oxygen species (ROS) was high at 2 kJ/m{sup 2}, suggesting that 2 kJ/m{sup 2} would already be toxic. This result was supported by other enzymatic activities, such as GSH levels, glutathione peroxidase, glutathione S-transferase, and glutathione reductase. For dose dependency, low doses of UV-B radiation (2, 4, and 6 kJ/m{sup 2}) significantly up-regulated the examined genes (e.g. RPA, DNA-PK, Ku70, and Ku80). For the time course study, RPA genes showed immediate up-regulation but returned to basal or lower expression levels compared to the control 3 h after UV-B exposure. The DNA-PK and Ku70/80 genes significantly increased, indicating that they may be involved in repairing processes against a low dose of UV-B exposure (2 kJ/m{sup 2}). At the basal level, the hsp90{alpha}1 gene showed the highest expression, and followed by hsp10, hsp30, hsp60, and hsc70, and hsp90{beta} in adults (w/o egg). In eggs, the hsp10 gene was expressed the highest, and followed by hsp30, hsp27, hsp90{alpha}1, and hsp60 genes. In real-time RT-PCR array on rotifer hsp genes, low doses of UV-B radiation (2 and 4 kJ/m{sup 2}) showed up-regulation of several hsp genes but most of the hsp

  3. Proliferation rate but not mismatch repair affects the long-term response of colon carcinoma cells to 5FU treatment.

    Science.gov (United States)

    Choudhary, B; Hanski, M L; Zeitz, M; Hanski, C

    2012-07-01

    The role of mismatch repair (MMR) in the response of colon carcinoma cells to 5-fluorouracil (5FU) is not well understood. In most of the in vitro studies only short-term response was investigated. We focussed here on the influence of MMR status on the mechanism of the short- and long-term response to clinically relevant 5FU concentrations by using isogenic or semiisogenic cell line pairs expressing/nonexpressing the hMLH1 protein, an important component of the MMR system. We show that the lower survival of MMR-proficient than of MMR-deficient cells in the clonogenic survival assay is due to a more frequent early cell arrest and to subsequent senescence. By contrast, the long-term cell growth after treatment, which is also affected by long-term arrest and senescence, is independent from the MMR status. The overall effect on the long-term cell growth is a cumulative result of cell proliferation rate-dependent growth inhibition, apoptosis and necrotic cell death. The main long-term cytotoxic effect of 5FU is the inhibition of growth while apoptosis and the necrotic cell death are minor contributions.

  4. The DNA-mismatch repair enzyme hMSH2 modulates UV-B-induced cell cycle arrest and apoptosis in melanoma cells.

    Science.gov (United States)

    Seifert, Markus; Scherer, Stefan J; Edelmann, Wilfried; Böhm, Markus; Meineke, Viktor; Löbrich, Markus; Tilgen, Wolfgang; Reichrath, Jörg

    2008-01-01

    The mechanisms by which the post-replicative DNA mismatch repair (MMR) enzyme MSH2 is involved in the complex response mechanisms to UV damage are yet to be clarified. Here, we show increased levels of MSH2 mRNA in malignant melanoma, metastases of melanoma, and melanoma cell (MeWo) lines as compared with melanocytic nevi or primary cultured benign melanocytes. UV-B treatment modulated MSH2 expression and silencing of MSH2 gene expression using small interfering RNA technology regulated UV-B-induced cell cycle arrest and apoptosis in human MeWo. We show that MSH2-deficient non-malignant mouse fibroblasts (MEF-/-) are partially resistant against UV-B-induced apoptosis and show reduced S-Phase accumulation. In addition, we show that an Msh2 point mutation (MEFGA) that affects MMR does not affect UV-B-induced apoptosis. In conclusion, we demonstrate that MSH2 modulates in human melanocytes both UV-B-induced cell cycle regulation and apoptosis, most likely via independent, uncoupled mechanisms.

  5. Mismatch repair status and synchronous metastases in colorectal cancer

    DEFF Research Database (Denmark)

    Nordholm-Carstensen, Andreas; Krarup, Peter-Martin; Morton, Dion

    2015-01-01

    The causality between the metastatic potential, mismatch repair status (MMR) and survival in colorectal cancer (CRC) is complex. This study aimed to investigate the impact of MMR in CRC on the occurrence of synchronous metastases (SCCM) and survival in patients with SCCM on a national basis....... A nationwide cohort study of 6,692 patients diagnosed with CRC between 2010 and 2012 was conducted. Data were prospectively entered into the Danish Colorectal Cancer Group's database and merged with data from the Danish Pathology Registry and the National Patient Registry. Multivariable and multinomial...... metastases (aOR = 0.69, 95% CI:0.26-1.29, p = 0.436) were unaffected by MMR. MMR in patients with SCCM had no impact on survival (Cox: adjusted Hazard Ratio (aHR) = 0.76, 95% CI: 0.54-1.06, p = 0.101; Proportional excess hazards: aHR = 0.73, 95% CI: 0.50-1.07, p = 0.111) when adjusting for other prognostic...

  6. Genetic variations in DNA repair genes, radiosensitivity to cancer and susceptibility to acute tissue reactions in radiotherapy-treated cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Chistiakov, Dimitry A. (Dept. of Pathology, Univ. of Pittsburgh, Pittsburgh (US)); Voronova, Natalia V. (Dept. of Molecular Diagnostics, National Research Center GosNIIgenetika, Moscow (RU)); Chistiakov, Pavel A. (Dept. of Radiology, Cancer Research Center, Moscow (RU))

    2008-06-15

    Ionizing radiation is a well established carcinogen for human cells. At low doses, radiation exposure mainly results in generation of double strand breaks (DSBs). Radiation-related DSBs could be directly linked to the formation of chromosomal rearrangements as has been proven for radiation-induced thyroid tumors. Repair of DSBs presumably involves two main pathways, non-homologous end joining (NHEJ) and homologous recombination (HR). A number of known inherited syndromes, such as ataxia telangiectasia, ataxia-telangiectasia like-disorder, radiosensitive severe combined immunodeficiency, Nijmegen breakage syndrome, and LIG4 deficiency are associated with increased radiosensitivity and/or cancer risk. Many of them are caused by mutations in DNA repair genes. Recent studies also suggest that variations in the DNA repair capacity in the general population may influence cancer susceptibility. In this paper, we summarize the current status of DNA repair proteins as potential targets for radiation-induced cancer risk. We will focus on genetic alterations in genes involved in HR- and NHEJ-mediated repair of DSBs, which could influence predisposition to radiation-related cancer and thereby explain interindividual differences in radiosensitivity or radioresistance in a general population

  7. Hereditary Ovarian Cancer: Not Only BRCA 1 and 2 Genes

    Directory of Open Access Journals (Sweden)

    Angela Toss

    2015-01-01

    Full Text Available More than one-fifth of ovarian tumors have hereditary susceptibility and, in about 65–85% of these cases, the genetic abnormality is a germline mutation in BRCA genes. Nevertheless, several other suppressor genes and oncogenes have been associated with hereditary ovarian cancers, including the mismatch repair (MMR genes in Lynch syndrome, the tumor suppressor gene, TP53, in the Li-Fraumeni syndrome, and several other genes involved in the double-strand breaks repair system, such as CHEK2, RAD51, BRIP1, and PALB2. The study of genetic discriminators and deregulated pathways involved in hereditary ovarian syndromes is relevant for the future development of molecular diagnostic strategies and targeted therapeutic approaches. The recent development and implementation of next-generation sequencing technologies have provided the opportunity to simultaneously analyze multiple cancer susceptibility genes, reduce the delay and costs, and optimize the molecular diagnosis of hereditary tumors. Particularly, the identification of mutations in ovarian cancer susceptibility genes in healthy women may result in a more personalized cancer risk management with tailored clinical and radiological surveillance, chemopreventive approaches, and/or prophylactic surgeries. On the other hand, for ovarian cancer patients, the identification of mutations may provide potential targets for biologic agents and guide treatment decision-making.

  8. The Saccharomyces cerevisiae RAD7 and RAD16 genes are required for inducible excision of endonuclease III sensitive-sites, yet are not needed for the repair of these lesions following a single UV dose.

    Science.gov (United States)

    Scott, A D; Waters, R

    1997-01-31

    The RAD7 and RAD16 genes of Saccharomyces cerevisiae have roles in the repair of UV induced CPDs in nontranscribed genes [1], and in the repair of CPDs in the nontranscribed strand of transcribed genes [2]. Previously, we identified an inducible component to nucleotide excision repair (NER), which is absent in a rad16 delta strain [3]. We have examined the repair of UV induced endonuclease III sensitive-sites (EIIISS), and have shown repair of these lesions to proceed by NER but their removal from nontranscribed regions is independent of RAD7 and RAD16. Furthermore, EIIISS are repaired with equal efficiency from both transcribed and nontranscribed genes [4]. In order to dissect the roles of RAD7 and RAD16 in the above processes we examined the repair of EIIISS in the MAT alpha and HML alpha loci, which are, respectively, transcriptionally active and inactive in alpha haploid cells. These loci have elevated levels of these lesions after UV (in genomic DNA EIIISS constitute about 10% of total lesions, whereas CPDs are about 70% of total lesions). We have shown that excision of UV induced EIIISS is enhanced following a prior UV irradiation. No enhancement of repair was detected in either the rad7 delta or the rad16 delta mutant. The fact that RAD7 and RAD16 are not required for the repair of EIIISS per se yet are required for the enhanced excision of these lesions from MAT alpha and HML alpha suggests two possibilities. These genes have two roles in NER, namely in the repair of CPDs from nontranscribed sequences, and in enhancing NER itself regardless of whether these genes' products are required for the excision of the specific lesion being repaired. In the latter case, the induction of RAD7 and RAD16 may increase the turnover of complexes stalled in nontranscribed DNA so as to increase the availability of NER proteins for the repair of CPDs and EIIISS in all regions of the genome.

  9. Promoter Hypermethylation of DNA Repair Gene MGMT in Laryngeal Squamous Cell Carcinoma

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The relationship between hypermethylation of CpG islands in the promoter regions of O6methylguanine DNA methyltransferase (MGMT)genes and laryngeal squamous cell carcinoma was explored. Methylation-specific PCR and semi-quantitative RT-PCR were used to study the promoter methylation and mRNA expression of the MGMT gene in laryngeal carcinoma tissues, t issues adjacent to the tumor and normal laryngeal tissues. Hypermethylation of MGMT gene was detected in 16 samples of 46 (34.8 %) laryngeal squamous cell carcinoma samples. However, the MGMT hypermethylation was not detected in all tissues adjacent to the tumors and normal tissues. No significant difference in MGMT gene hypermethylation was found in samples with different histological grades (x2= 3. 130, P=0. 077) or in samples from patients with different TNM status (x2=3. 957, P=0. 138). No expression of MGMT mRNA was detected in all hypermethylated laryngeal carcinoma tissues. The expression of MGMT mRNA was detected in all unmethylated laryngeal carcinoma tissues, tissues adjacent to the tumors and normal tissues. It suggests that MGMT gene promoter hypermethylation is associated with MGMT gene transcription loss in laryngeal carcinoma tissues and possibly plays an important role in carcinogenesis of laryngeal tissues.

  10. Immunoglobulin genes undergo legitimate repair in human B cells not only after cis- but also frequent trans-class switch recombination.

    Science.gov (United States)

    Laffleur, B; Bardet, S M; Garot, A; Brousse, M; Baylet, A; Cogné, M

    2014-01-01

    Immunoglobulin (Ig) genes specifically recruit activation-induced deaminase (AID) for 'on-target' DNA deamination, initiating either variable (V) region somatic hypermutation, or double-strand break intermediates of class switch recombination (CSR). Such breaks overwhelmingly undergo legitimate intra-Ig repair rather than rare illegitimate and potentially oncogenic junctions outside of Ig loci. We show that in human B cells, legitimate synapsis and repair efficiently join Ig genes whether physically linked on one chromosome or located apart on both alleles. This indicates mechanisms faithfully recognizing and/or pairing loci with homology in structure and accessibility, thus licensing interchromosomal trans-CSR junctions while usually preventing illegitimate interchromosomal recombination with AID off-target genes. Physical linkage of IgH genes in cis on the same allele just increases the likelihood of legitimate repair by another fourfold. The strongest force driving CSR might thus be recognition of legitimate target genes. Formation of IgH intra-allelic loops along this process would then constitute a consequence rather than a pre-requisite of this gene-pairing process.

  11. Genetic variants in DNA double-strand break repair genes and risk of salivary gland carcinoma: a case-control study.

    Directory of Open Access Journals (Sweden)

    Li Xu

    Full Text Available DNA double strand break (DSB repair is the primary defense mechanism against ionizing radiation-induced DNA damage. Ionizing radiation is the only established risk factor for salivary gland carcinoma (SGC. We hypothesized that genetic variants in DSB repair genes contribute to individual variation in susceptibility to SGC. To test this hypothesis, we conducted a case-control study in which we analyzed 415 single nucleotide polymorphisms (SNPs in 45 DSB repair genes in 352 SGC cases and 598 controls. Multivariate logistic regression analysis was performed to calculate odds ratios (ORs and 95% confidence intervals (CIs. Rs3748522 in RAD52 and rs13180356 in XRCC4 were significantly associated with SGC after Bonferroni adjustment; ORs (95% CIs for the variant alleles of these SNPs were 1.71 (1.40-2.09, P = 1.70 × 10(-7 and 0.58 (0.45-0.74, P = 2.00 × 10(-5 respectively. The genetic effects were modulated by histological subtype. The association of RAD52-rs3748522 with SGC was strongest for mucoepidermoid carcinoma (OR = 2.21, 95% CI: 1.55-3.15, P = 1.25 × 10(-5, n = 74, and the association of XRCC4-rs13180356 with SGC was strongest for adenoid cystic carcinoma (OR = 0.60, 95% CI: 0.42-0.87, P = 6.91 × 10(-3, n = 123. Gene-level association analysis revealed one gene, PRKDC, with a marginally significant association with SGC risk in non-Hispanic whites. To our knowledge, this study is the first to comprehensively evaluate the genetic effect of DSB repair genes on SGC risk. Our results indicate that genetic variants in the DSB repair pathways contribute to inter-individual differences in susceptibility to SGC and show that the impact of genetic variants differs by histological subtype. Independent studies are warranted to confirm these findings.

  12. Loss of genes related to Nucleotide Excision Repair (NER) and implications for reductive genome evolution in symbionts of deep-sea vesicomyid clams

    Science.gov (United States)

    Shimamura, Shigeru; Kaneko, Takashi; Ozawa, Genki; Matsumoto, Mamiko Nishino; Koshiishi, Takeru; Takaki, Yoshihiro; Kato, Chiaki; Takai, Ken; Yoshida, Takao; Fujikura, Katsunori; Barry, James P.

    2017-01-01

    Intracellular thioautotrophic symbionts of deep-sea vesicomyid clams lack some DNA repair genes and are thought to be undergoing reductive genome evolution (RGE). In this study, we addressed two questions, 1) how these symbionts lost their DNA repair genes and 2) how such losses affect RGE. For the first question, we examined genes associated with nucleotide excision repair (NER; uvrA, uvrB, uvrC, uvrD, uvrD paralog [uvrDp] and mfd) in 12 symbionts of vesicomyid clams belonging to two clades (5 clade I and 7 clade II symbionts). While uvrA, uvrDp and mfd were conserved in all symbionts, uvrB and uvrC were degraded in all clade I symbionts but were apparently intact in clade II symbionts. UvrD was disrupted in two clade II symbionts. Among the intact genes in Ca. Vesicomyosocius okutanii (clade I), expressions of uvrD and mfd were detected by reverse transcription-polymerase chain reaction (RT-PCR), but those of uvrA and uvrDp were not. In contrast, all intact genes were expressed in the symbiont of Calyptogena pacifica (clade II). To assess how gene losses affect RGE (question 2), genetic distances of the examined genes in symbionts from Bathymodiolus septemdierum were shown to be larger in clade I than clade II symbionts. In addition, these genes had lower guanine+cytosine (GC) content and higher repeat sequence densities in clade I than measured in clade II. Our results suggest that NER genes are currently being lost from the extant lineages of vesicomyid clam symbionts. The loss of NER genes and mutY in these symbionts is likely to promote increases in genetic distance and repeat sequence density as well as reduced GC content in genomic genes, and may have facilitated reductive evolution of the genome. PMID:28199404

  13. Phylogeny of Mycobacterium tuberculosis Beijing strains constructed from polymorphisms in genes involved in DNA replication, recombination and repair.

    Directory of Open Access Journals (Sweden)

    Olga Mestre

    Full Text Available BACKGROUND: The Beijing family is a successful group of M. tuberculosis strains, often associated with drug resistance and widely distributed throughout the world. Polymorphic genetic markers have been used to type particular M. tuberculosis strains. We recently identified a group of polymorphic DNA repair replication and recombination (3R genes. It was shown that evolution of M. tuberculosis complex strains can be studied using 3R SNPs and a high-resolution tool for strain discrimination was developed. Here we investigated the genetic diversity and propose a phylogeny for Beijing strains by analyzing polymorphisms in 3R genes. METHODOLOGY/PRINCIPAL FINDINGS: A group of 3R genes was sequenced in a collection of Beijing strains from different geographic origins. Sequence analysis and comparison with the ones of non-Beijing strains identified several SNPs. These SNPs were used to type a larger collection of Beijing strains and allowed identification of 26 different sequence types for which a phylogeny was constructed. Phylogenetic relationships established by sequence types were in agreement with evolutionary pathways suggested by other genetic markers, such as Large Sequence Polymorphisms (LSPs. A recent Beijing genotype (Bmyc10, which included 60% of strains from distinct parts of the world, appeared to be predominant. CONCLUSIONS/SIGNIFICANCE: We found SNPs in 3R genes associated with the Beijing family, which enabled discrimination of different groups and the proposal of a phylogeny. The Beijing family can be divided into different groups characterized by particular genetic polymorphisms that may reflect pathogenic features. These SNPs are new, potential genetic markers that may contribute to better understand the success of the Beijing family.

  14. Repair of full-thickness articular cartilage defects by cultured mesenchymal stem cells transfected with the transforming growth factor {beta}{sub 1} gene

    Energy Technology Data Exchange (ETDEWEB)

    Guo Xiaodong [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Zheng Qixin [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Yang Shuhua [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Shao Zengwu [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Yuan Quan [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Pan Zhengqi [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Tang Shuo [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Liu Kai [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Quan Daping [Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

    2006-12-15

    Articular cartilage repair remains a clinical and scientific challenge with increasing interest focused on the combined techniques of gene transfer and tissue engineering. Transforming growth factor beta 1 (TGF-{beta}{sub 1}) is a multifunctional molecule that plays a central role in promotion of cartilage repair, and inhibition of inflammatory and alloreactive immune response. Cell mediated gene therapy can allow a sustained expression of TGF-{beta}{sub 1} that may circumvent difficulties associated with growth factor delivery. The objective of this study was to investigate whether TGF-{beta}{sub 1} gene modified mesenchymal stem cells (MSCs) could enhance the repair of full-thickness articular cartilage defects in allogeneic rabbits. The pcDNA{sub 3}-TGF-{beta}{sub 1} gene transfected MSCs were seeded onto biodegradable poly-L-lysine coated polylactide (PLA) biomimetic scaffolds in vitro and allografted into full-thickness articular cartilage defects in 18 New Zealand rabbits. The pcDNA{sub 3} gene transfected MSCs/biomimetic scaffold composites and the cell-free scaffolds were taken as control groups I and II, respectively. The follow-up times were 2, 4, 12 and 24 weeks. Macroscopical, histological and ultrastructural studies were performed. In vitro SEM studies found that abundant cartilaginous matrices were generated and completely covered the interconnected pores of the scaffolds two weeks post-seeding in the experimental groups. In vivo, the quality of regenerated tissue improved over time with hyaline cartilage filling the chondral region and a mixture of trabecular and compact bone filling the subchondral region at 24 weeks post-implantation. Joint repair in the experimental groups was better than that of either control group I or II, with respect to: (1) synthesis of hyaline cartilage specific extracellular matrix at the upper portion of the defect; (2) reconstitution of the subchondral bone at the lower portion of the defect and (3) inhibition of

  15. Attitudinal and Demographic Predictors of Measles-Mumps-Rubella Vaccine (MMR) Uptake during the UK Catch-Up Campaign 2008–09: Cross-Sectional Survey

    Science.gov (United States)

    Brown, Katrina; Fraser, Graham; Ramsay, Mary; Shanley, Ruth; Cowley, Noel; van Wijgerden, Johan; Toff, Penelope; Falconer, Michelle; Hudson, Michael; Green, John; Kroll, J. Simon; Vincent, Charles; Sevdalis, Nick

    2011-01-01

    Background and Objective Continued suboptimal measles-mumps-rubella (MMR) vaccine uptake has re-established measles epidemic risk, prompting a UK catch-up campaign in 2008–09 for children who missed MMR doses at scheduled age. Predictors of vaccine uptake during catch-ups are poorly understood, however evidence from routine schedule uptake suggests demographics and attitudes may be central. This work explored this hypothesis using a robust evidence-based measure. Design Cross-sectional self-administered questionnaire with objective behavioural outcome. Setting and Participants 365 UK parents, whose children were aged 5–18 years and had received <2 MMR doses before the 2008–09 UK catch-up started. Main Outcome Measures Parents' attitudes and demographics, parent-reported receipt of invitation to receive catch-up MMR dose(s), and catch-up MMR uptake according to child's medical record (receipt of MMR doses during year 1 of the catch-up). Results Perceived social desirability/benefit of MMR uptake (OR = 1.76, 95% CI = 1.09–2.87) and younger child age (OR = 0.78, 95% CI = 0.68–0.89) were the only independent predictors of catch-up MMR uptake in the sample overall. Uptake predictors differed by whether the child had received 0 MMR doses or 1 MMR dose before the catch-up. Receipt of catch-up invitation predicted uptake only in the 0 dose group (OR = 3.45, 95% CI = 1.18–10.05), whilst perceived social desirability/benefit of MMR uptake predicted uptake only in the 1 dose group (OR = 9.61, 95% CI = 2.57–35.97). Attitudes and demographics explained only 28% of MMR uptake in the 0 dose group compared with 61% in the 1 dose group. Conclusions Catch-up MMR invitations may effectively move children from 0 to 1 MMR doses (unimmunised to partially immunised), whilst attitudinal interventions highlighting social benefits of MMR may effectively move children from 1 to 2 MMR doses (partially to fully immunised). Older children may be

  16. Attitudinal and demographic predictors of measles-mumps-rubella vaccine (MMR uptake during the UK catch-up campaign 2008-09: cross-sectional survey.

    Directory of Open Access Journals (Sweden)

    Katrina Brown

    Full Text Available BACKGROUND AND OBJECTIVE: Continued suboptimal measles-mumps-rubella (MMR vaccine uptake has re-established measles epidemic risk, prompting a UK catch-up campaign in 2008-09 for children who missed MMR doses at scheduled age. Predictors of vaccine uptake during catch-ups are poorly understood, however evidence from routine schedule uptake suggests demographics and attitudes may be central. This work explored this hypothesis using a robust evidence-based measure. DESIGN: Cross-sectional self-administered questionnaire with objective behavioural outcome. SETTING AND PARTICIPANTS: 365 UK parents, whose children were aged 5-18 years and had received <2 MMR doses before the 2008-09 UK catch-up started. MAIN OUTCOME MEASURES: Parents' attitudes and demographics, parent-reported receipt of invitation to receive catch-up MMR dose(s, and catch-up MMR uptake according to child's medical record (receipt of MMR doses during year 1 of the catch-up. RESULTS: Perceived social desirability/benefit of MMR uptake (OR = 1.76, 95% CI = 1.09-2.87 and younger child age (OR = 0.78, 95% CI = 0.68-0.89 were the only independent predictors of catch-up MMR uptake in the sample overall. Uptake predictors differed by whether the child had received 0 MMR doses or 1 MMR dose before the catch-up. Receipt of catch-up invitation predicted uptake only in the 0 dose group (OR = 3.45, 95% CI = 1.18-10.05, whilst perceived social desirability/benefit of MMR uptake predicted uptake only in the 1 dose group (OR = 9.61, 95% CI = 2.57-35.97. Attitudes and demographics explained only 28% of MMR uptake in the 0 dose group compared with 61% in the 1 dose group. CONCLUSIONS: Catch-up MMR invitations may effectively move children from 0 to 1 MMR doses (unimmunised to partially immunised, whilst attitudinal interventions highlighting social benefits of MMR may effectively move children from 1 to 2 MMR doses (partially to fully immunised. Older children may be

  17. Repair of endonuclease-induced double-strand breaks in Saccharomyces cerevisiae: essential role for genes associated with nonhomologous end-joining.

    OpenAIRE

    Lewis, L K; Westmoreland, J W; Resnick, M A

    1999-01-01

    Repair of double-strand breaks (DSBs) in chromosomal DNA by nonhomologous end-joining (NHEJ) is not well characterized in the yeast Saccharomyces cerevisiae. Here we demonstrate that several genes associated with NHEJ perform essential functions in the repair of endonuclease-induced DSBs in vivo. Galactose-induced expression of EcoRI endonuclease in rad50, mre11, or xrs2 mutants, which are deficient in plasmid DSB end-joining and some forms of recombination, resulted in G2 arrest and rapid ce...

  18. Cobalt-induced genotoxicity in male zebrafish (Danio rerio), with implications for reproduction and expression of DNA repair genes

    Energy Technology Data Exchange (ETDEWEB)

    Reinardy, Helena C.; Syrett, James R. [School of Biomedical and Biological Sciences, University of Plymouth (United Kingdom); Jeffree, Ross A. [Faculty of Science, University of Technology, Sydney, PO Box 123, Broadway, NSW 2007 (Australia); Henry, Theodore B., E-mail: ted.henry@plymouth.ac.uk [School of Biomedical and Biological Sciences, University of Plymouth (United Kingdom); Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN 37996 (United States); Department of Forestry, Wildlife and Fisheries, University of Tennessee, Knoxville, TN 37996. USA (United States); Jha, Awadhesh N. [School of Biomedical and Biological Sciences, The University of Plymouth (United Kingdom)

    2013-01-15

    Although cobalt (Co) is an environmental contaminant of surface waters in both radioactive (e.g. {sup 60}Co) and non-radioactive forms, there is relatively little information about Co toxicity in fishes. The objective of this study was to investigate acute and chronic toxicity of Co in zebrafish, with emphasis on male genotoxicity and implications for reproductive success. The lethal concentration for 50% mortality (LC{sub 50}) in larval zebrafish exposed (96 h) to 0-50 mg l{sup -1} Co was 35.3 {+-} 1.1 (95% C.I.) mg l{sup -1} Co. Adult zebrafish were exposed (13 d) to sub-lethal (0-25 mg l{sup -1}) Co and allowed to spawn every 4 d and embryos were collected. After 12-d exposure, fertilisation rate was reduced (6% total eggs fertilised, 25 mg l{sup -1}) and embryo survival to hatching decreased (60% fertilised eggs survived, 25 mg l{sup -1}). A concentration-dependent increase in DNA strand breaks was detected in sperm from males exposed (13 d) to Co, and DNA damage in sperm returned to control levels after males recovered for 6 d in clean water. Induction of DNA repair genes (rad51, xrcc5, and xrcc6) in testes was complex and not directly related to Co concentration, although there was significant induction in fish exposed to 15 and 25 mg l{sup -1} Co relative to controls. Induction of 4.0 {+-} 0.9, 2.5 {+-} 0.7, and 3.1 {+-} 0.7-fold change (mean {+-} S.E.M. for rad51, xrcc5, and xrcc6, respectively) was observed in testes at the highest Co concentration (25 mg l{sup -1}). Expression of these genes was not altered in offspring (larvae) spawned after 12-d exposure. Chronic exposure to Co resulted in DNA damage in sperm, induction of DNA repair genes in testes, and indications of reduced reproductive success.

  19. Somatic mutations of APC gene in carcinomas from hereditary non-polyposis colorectal cancer patients

    Institute of Scientific and Technical Information of China (English)

    Jian Huang; Shu Zheng; Shen-Hang Jin; Su-Zhan Zhang

    2004-01-01

    AIM: To investigate the mutational features of adenomatous polyposis coii (APC) gene and its possible arising mechanism in hereditary non-polyposis colorectal cancers (HNPCC).METHODS: PCR-based In Vitro Synthesized Protein Test (IVSP) assay and sequencing analysis were used to confirm somatic mutations of whole APC gene in 19 HNPCC cases. RESULTS: Eleven cases with 13 mutations were determined to harbor APC mutations. The prevalence of APC mutation was 58%(11/19). The mutations consisted of 9 frameshift and 4 nonsense ones, indicating that there were more frameshift mutations (69%). The frameshift mutations allexhibited deletion or insertion of 1-2 bp and most of them (7/9) happened at simple nucleotide repeat sequences, particularly within (A)n tracts (5/9). All point mutations presented C-to-T transitions at CpG sites. CONCLUSION: Mutations of APC gene were detected in more than half of HNPCC, indicating that its mutation was a common molecular event and might play an important role in the tumorigenesis of HNPCC. Locations of frameshift mutations at simple nucleotide repeat sequences and point mutations at CpG sites suggested that many mutations probably derived from endogenous processes including mismatch repair (MMR) deficiency. Defective MMR might affect the nature of APC mutations in HNPCC and likely occur earlier than APC mutational inactivation in some patients.

  20. Integration-defective lentiviral vector mediates efficient gene editing through homology-directed repair in human embryonic stem cells.

    Science.gov (United States)

    Wang, Yebo; Wang, Yingjia; Chang, Tammy; Huang, He; Yee, Jiing-Kuan

    2016-11-28

    Human embryonic stem cells (hESCs) are used as platforms for disease study, drug screening and cell-based therapy. To facilitate these applications, it is frequently necessary to genetically manipulate the hESC genome. Gene editing with engineered nucleases enables site-specific genetic modification of the human genome through homology-directed repair (HDR). However, the frequency of HDR remains low in hESCs. We combined efficient expression of engineered nucleases and integration-defective lentiviral vector (IDLV) transduction for donor template delivery to mediate HDR in hESC line WA09. This strategy led to highly efficient HDR with more than 80% of the selected WA09 clones harboring the transgene inserted at the targeted genomic locus. However, certain portions of the HDR clones contained the concatemeric IDLV genomic structure at the target site, probably resulted from recombination of the IDLV genomic input before HDR with the target. We found that the integrase protein of IDLV mediated the highly efficient HDR through the recruitment of a cellular protein, LEDGF/p75. This study demonstrates that IDLV-mediated HDR is a powerful and broadly applicable technology to carry out site-specific gene modification in hESCs.

  1. Methylation and protein expression of DNA repair genes: association with chemotherapy exposure and survival in sporadic ovarian and peritoneal carcinomas

    Directory of Open Access Journals (Sweden)

    Walsh Tom

    2009-07-01

    Full Text Available Abstract Background DNA repair genes critically regulate the cellular response to chemotherapy and epigenetic regulation of these genes may be influenced by chemotherapy exposure. Restoration of BRCA1 and BRCA2 mediates resistance to platinum chemotherapy in recurrent BRCA1 and BRCA2 mutated hereditary ovarian carcinomas. We evaluated BRCA1, BRCA2, and MLH1 protein expression in 115 sporadic primary ovarian carcinomas, of which 31 had paired recurrent neoplasms collected after chemotherapy. Additionally, we assessed whether promoter methylation of BRCA1, MLH1 or FANCF influenced response to chemotherapy or explained alterations in protein expression after chemotherapy exposure. Results Of 115 primary sporadic ovarian carcinomas, 39 (34% had low BRCA1 protein and 49 (42% had low BRCA2 expression. BRCA1 and BRCA2 protein expression were highly concordant (p Conclusion Low BRCA1 expression in primary sporadic ovarian carcinoma is associated with prolonged survival. Recurrent ovarian carcinomas commonly have increased BRCA1 and/or BRCA2 protein expression post chemotherapy exposure which could mediate resistance to platinum based therapies. However, alterations in expression of these proteins after chemotherapy are not commonly mediated by promoter methylation, and other regulatory mechanisms are likely to contribute to these alterations.

  2. Defects in the DNA repair and transcription gene ERCC2(XPD) in trichothiodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Takayama, K.; Salazar, E.P.; Thompson, L.H. [Lawrence Livermore National Lab., CA (United States)] [and others

    1996-02-01

    Trichothiodystrophy (TTD) is a rare autosomal recessive disorder characterized by brittle hair with reduced sulfur content, ichthyosis, peculiar face, and mental and growth retardation. Clinical photosensitivity is present in {approximately}50% of TTD patients but is not associated with an elevated frequency of cancers. Previous complementation studies show that the photosensitivity in nearly all of the studied patients is due to a defect in the same genetic locus that underlies the cancer-prone genetic disorder xeroderma pigmentosum group D (XP-D). Nucleotide-sequence analysis of the ERCC2 cDNA from three TTD cell strains (TTD1VI, TTD3VI, and TTD1RO) revealed mutations within the region from amino acid 713-730 and within previously identified helicase functional domains. The various clinical presentations and DNA repair characteristics of the cell strains can be correlated with the particular mutations found in the ERCC2 locus. Mutations of Arg658 to either His or Cys correlate with TTD cell strains with intermediate UV-sensitivity, mutation of Arg722 to Trp correlates with highly UV-sensitive TTD cell strains, and mutation of Arg683 to Trp correlates with XP-D. Alleles with mutation of Arg616 to Pro or with the combined mutation of Leu461 to Val and deletion of 716-730 are found in both XP-D and TTD cell strains. 39 refs., 2 figs., 3 tabs.

  3. DNA repair mechanisms in eukaryotes: Special focus in Entamoeba histolytica and related protozoan parasites.

    Science.gov (United States)

    López-Camarillo, César; Lopez-Casamichana, Mavil; Weber, Christian; Guillen, Nancy; Orozco, Esther; Marchat, Laurence A

    2009-12-01

    Eukaryotic cell viability highly relies on genome stability and DNA integrity maintenance. The cellular response to DNA damage mainly consists of six biological conserved pathways known as homologous recombination repair (HRR), non-homologous end-joining (NHEJ), base excision repair (BER), mismatch repair (MMR), nucleotide excision repair (NER), and methyltransferase repair that operate in a concerted way to minimize genetic information loss due to a DNA lesion. Particularly, protozoan parasites survival depends on DNA repair mechanisms that constantly supervise chromosomes to correct damaged nucleotides generated by cytotoxic agents, host immune pressure or cellular processes. Here we reviewed the current knowledge about DNA repair mechanisms in the most relevant human protozoan pathogens. Additionally, we described the recent advances to understand DNA repair mechanisms in Entamoeba histolytica with special emphasis in the use of genomic approaches based on bioinformatic analysis of parasite genome sequence and microarrays technology.

  4. Candidate driver genes involved in genome maintenance and DNA repair in Sézary syndrome.

    Science.gov (United States)

    Woollard, Wesley J; Pullabhatla, Venu; Lorenc, Anna; Patel, Varsha M; Butler, Rosie M; Bayega, Anthony; Begum, Nelema; Bakr, Farrah; Dedhia, Kiran; Fisher, Joshua; Aguilar-Duran, Silvia; Flanagan, Charlotte; Ghasemi, Aria A; Hoffmann, Ricarda M; Castillo-Mosquera, Nubia; Nuttall, Elisabeth A; Paul, Arisa; Roberts, Ceri A; Solomonidis, Emmanouil G; Tarrant, Rebecca; Yoxall, Antoinette; Beyers, Carl Z; Ferreira, Silvia; Tosi, Isabella; Simpson, Michael A; de Rinaldis, Emanuele; Mitchell, Tracey J; Whittaker, Sean J

    2016-06-30

    Sézary syndrome (SS) is a leukemic variant of cutaneous T-cell lymphoma (CTCL) and represents an ideal model for study of T-cell transformation. We describe whole-exome and single-nucleotide polymorphism array-based copy number analyses of CD4(+) tumor cells from untreated patients at diagnosis and targeted resequencing of 101 SS cases. A total of 824 somatic nonsynonymous gene variants were identified including indels, stop-gain/loss, splice variants, and recurrent gene variants indicative of considerable molecular heterogeneity. Driver genes identified using MutSigCV include POT1, which has not been previously reported in CTCL; and TP53 and DNMT3A, which were also identified consistent with previous reports. Mutations in PLCG1 were detected in 11% of tumors including novel variants not previously described in SS. This study is also the first to show BRCA2 defects in a significant proportion (14%) of SS tumors. Aberrations in PRKCQ were found to occur in 20% of tumors highlighting selection for activation of T-cell receptor/NF-κB signaling. A complex but consistent pattern of copy number variants (CNVs) was detected and many CNVs involved genes identified as putative drivers. Frequent defects involving the POT1 and ATM genes responsible for telomere maintenance were detected and may contribute to genomic instability in SS. Genomic aberrations identified were enriched for genes implicated in cell survival and fate, specifically PDGFR, ERK, JAK STAT, MAPK, and TCR/NF-κB signaling; epigenetic regulation (DNMT3A, ASLX3, TET1-3); and homologous recombination (RAD51C, BRCA2, POLD1). This study now provides the basis for a detailed functional analysis of malignant transformation of mature T cells and improved patient stratification and treatment.

  5. Prevalence of Germline Mutations in Genes Engaged in DNA Damage Repair by Homologous Recombination in Patients with Triple-Negative and Hereditary Non-Triple-Negative Breast Cancers.

    Directory of Open Access Journals (Sweden)

    Pawel Domagala

    Full Text Available This study sought to assess the prevalence of common germline mutations in several genes engaged in the repair of DNA double-strand break by homologous recombination in patients with triple-negative breast cancers and hereditary non-triple-negative breast cancers. Tumors deficient in this type of DNA damage repair are known to be especially sensitive to DNA cross-linking agents (e.g., platinum drugs and to poly(ADP-ribose polymerase (PARP inhibitors.Genetic testing was performed for 36 common germline mutations in genes engaged in the repair of DNA by homologous recombination, i.e., BRCA1, BRCA2, CHEK2, NBN, ATM, PALB2, BARD1, and RAD51D, in 202 consecutive patients with triple-negative breast cancers and hereditary non-triple-negative breast cancers.Thirty five (22.2% of 158 patients in the triple-negative group carried mutations in genes involved in DNA repair by homologous recombination, while 10 (22.7% of the 44 patients in the hereditary non-triple-negative group carried such mutations. Mutations in BRCA1 were most frequent in patients with triple-negative breast cancer (18.4%, and mutations in CHEK2 were most frequent in patients with hereditary non-triple-negative breast cancers (15.9%. In addition, in the triple-negative group, mutations in CHEK2, NBN, and ATM (3.8% combined were found, while mutations in BRCA1, NBN, and PALB2 (6.8% combined were identified in the hereditary non-triple-negative group.Identifying mutations in genes engaged in DNA damage repair by homologous recombination other than BRCA1/2 can substantially increase the proportion of patients with triple-negative breast cancer and hereditary non-triple-negative breast cancer who may be eligible for therapy using PARP inhibitors and platinum drugs.

  6. Polymorphisms in DNA repair genes XRCC2 and XRCC3 risk of gastric cancer in Turkey

    Directory of Open Access Journals (Sweden)

    İlhami Gok

    2014-09-01

    Full Text Available We studied the prevalence of polymorphisms in genes XRCC2 and XRCC3 in stomach cancer patients who lived in North Eastern Turkey. A total of 61 cancer patients and 78 controls were included in this study. Single nucleotide changes were studied in XRCC2 and XRCC3 genes at locus Arg188His and Thr241Met. Blood samples were taken from the patients and controls, and DNA was isolated. The regions of interest were amplified using a polymerase chain reaction method. After amplification, we used restriction enzymes (HphI and NcoI to digest the amplified product. Digested product was then run through gel electrophoresis. We identified changes in the nucleotides in these specific regions. It was found that the Arg188His polymorphism of the XRCC2 gene was about 39% (24 out of the 61 among cancer patients. However, only 15% (12 out of 78 of the control group indicated this polymorphism. We also observed that 18 of the 61 cancer patients (29% carried the Thr241Met polymorphism of the XRCC3 gene whereas 11 of the 78 (14% individuals in the control group had the polymorphism. Our results showed a significant difference in polymorphism ratios between the cancer patients and health control group for the regions of interest. This result clearly showed that these polymorphisms increase the risk of stomach cancer and might be a strong marker for early diagnosis of gastric cancer.

  7. DNA mismatch repair gene MSH6 implicated in determining age at natural menopause

    DEFF Research Database (Denmark)

    Perry, John R B; Hsu, Yi-Hsiang; Chasman, Daniel I

    2014-01-01

    The length of female reproductive lifespan is associated with multiple adverse outcomes, including breast cancer, cardiovascular disease and infertility. The biological processes that govern the timing of the beginning and end of reproductive life are not well understood. Genetic variants are kno...... to contribute to ∼50% of the variation in both age at menarche and menopause, but to date the known genes explain...

  8. INTRALESIONAL MEASLES, MUMPS AND RUBELLA (MMR VACCINE-AN EFFECTIVE THERAPEUTIC TOOL IN THE TREATMENT OF WART

    Directory of Open Access Journals (Sweden)

    Raju

    2015-11-01

    Full Text Available BACKGROUND: Warts are common cutaneous viral infection. Various therapeutic modalities have been using in treatment of wart, but none of them are standardised. Immunotherapy is new current approach in the treatment of wart. AIMS: To know the efficacy and safety profile of Measles Mumps Rubella (MMR Vaccine in the treatment of wart. METHODS: MMR vaccine was injected into a largest single wart intralesionally and subsequent injections given every 2 weeks apart for about 3 to 5 times. Every month followup of patients was done to know the clearance of wart. RESULTS: Complete remission of warts seen in 70.4% of patients, partial remission seen in 22.2% and no response was seen in 7.4% of patients. No serious adverse side effects were seen in the current study. CONCLUSION: MMR vaccine can be considered as a safe, effective, inexpensive intralesional immunotherapeutic modality in the treatment of wart.

  9. Efficient gene targeting by homology-directed repair in rat zygotes using TALE nucleases.

    Science.gov (United States)

    Remy, Séverine; Tesson, Laurent; Menoret, Séverine; Usal, Claire; De Cian, Anne; Thepenier, Virginie; Thinard, Reynald; Baron, Daniel; Charpentier, Marine; Renaud, Jean-Baptiste; Buelow, Roland; Cost, Gregory J; Giovannangeli, Carine; Fraichard, Alexandre; Concordet, Jean-Paul; Anegon, Ignacio

    2014-08-01

    The generation of genetically modified animals is important for both research and commercial purposes. The rat is an important model organism that until recently lacked efficient genetic engineering tools. Sequence-specific nucleases, such as ZFNs, TALE nucleases, and CRISPR/Cas9 have allowed the creation of rat knockout models. Genetic engineering by homology-directed repair (HDR) is utilized to create animals expressing transgenes in a controlled way and to introduce precise genetic modifications. We applied TALE nucleases and donor DNA microinjection into zygotes to generate HDR-modified rats with large new sequences introduced into three different loci with high efficiency (0.62%-5.13% of microinjected zygotes). Two of these loci (Rosa26 and Hprt1) are known to allow robust and reproducible transgene expression and were targeted for integration of a GFP expression cassette driven by the CAG promoter. GFP-expressing embryos and four Rosa26 GFP rat lines analyzed showed strong and widespread GFP expression in most cells of all analyzed tissues. The third targeted locus was Ighm, where we performed successful exon exchange of rat exon 2 for the human one. At all three loci we observed HDR only when using linear and not circular donor DNA. Mild hypothermic (30°C) culture of zygotes after microinjection increased HDR efficiency for some loci. Our study demonstrates that TALE nuclease and donor DNA microinjection into rat zygotes results in efficient and reproducible targeted donor integration by HDR. This allowed creation of genetically modified rats in a work-, cost-, and time-effective manner.

  10. The Effect of Polymorphisms in DNA Repair Genes and Carcinogen Metabolizers on Leukocyte Telomere Length: A Cohort of Healthy Spanish Smokers.

    Science.gov (United States)

    Verde, Zoraida; Reinoso-Barbero, Luis; Chicharro, Luis; Resano, Pilar; Sánchez-Hernández, Ignacio; Rodríguez González-Moro, Jose Miguel; Bandrés, Fernando; Gómez-Gallego, Félix; Santiago, Catalina

    2016-04-01

    Smoking implies exposure to carcinogenic agents that causes DNA damage, which could be suspected to enhance telomere attrition. To protect and deal with DNA damage, cells possess mechanisms that repair and neutralize harmful substances. Polymorphisms altering DNA repair capacity or carcinogen metabolism may lead to synergistic effects with tobacco carcinogen-induced shorter telomere length independently of cancer interaction. The aim of this study was to explore the association between leukocyte telomere length (LTL) and several genetic polymorphisms in DNA repair genes and carcinogen metabolizers in a cohort of healthy smokers. We evaluated the effect of six genetic polymorphisms in cytochrome P1A1 (Ile462Val), XRCC1 (Arg399Gln), APEX1 (Asp148Glu), XRCC3 (Thr241Met), and XPD (Asp312Asn; Lys751Gln) on LTL in a cohort of 145 healthy smokers in addition to smoking habits. Logistic regression analysis showed an association between XRCC1 399Gln allele and shorter telomere length (OR = 5.03, 95% CI = 1.08% to 23.36%). There were not association between the rest of polymorphisms analyzed and LTL. Continuous exposure to tobacco could overwhelm the DNA repair machinery, making the effect of the polymorphisms that reduce repair capacity more pronounced. Analyzing the function of smoking-induced DNA-repair genes and LTL is an important goal in order to identify therapeutic targets to treat smoking-induced diseases. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Gene expression and DNA repair in progeroid syndromes and human aging.

    Science.gov (United States)

    Kyng, Kasper J; Bohr, Vilhelm A

    2005-11-01

    Human progeroid syndromes are caused by mutations in single genes accelerating some but not all features of normal aging. Most progeroid disorders are linked to defects in genome maintenance, and while it remains unknown if similar processes underlie normal and premature aging, they provide useful models for the study of aging. Altered transcription is speculated to play a causative role in aging, and is involved in the pathology of most if not all progeroid syndromes. Previous studies demonstrate that there is a similar pattern of gene expression changes in primary cells from old and Werner syndrome compared to young suggesting a presence of common cellular aging mechanisms in old and progeria. Here we review the role of transcription in progeroid syndromes and discuss the implications of similar transcription aberrations in normal and premature aging.

  12. Interactive effects of ultraviolet-B radiation and pesticide exposure on DNA photo-adduct accumulation and expression of DNA damage and repair genes in Xenopus laevis embryos.

    Science.gov (United States)

    Yu, Shuangying; Tang, Song; Mayer, Gregory D; Cobb, George P; Maul, Jonathan D

    2015-02-01

    Pesticide use and ultraviolet-B (UVB) radiation have both been suggested to adversely affect amphibians; however, little is known about their interactive effects. One potential adverse interaction could involve pesticide-induced dysregulation of DNA repair pathways, resulting in greater numbers of DNA photo-adducts from UVB exposure. In the present study, we investigated the interactive effects of UVB radiation and two common pesticides (endosulfan and α-cypermethrin) on induction of DNA photo-adducts and expression of DNA damage and repair related genes in African clawed frog (Xenopus laevis) embryos. We examined 13 genes that are, collectively, involved in stress defense, cell cycle arrest, nucleotide excision repair (NER), base excision repair, mismatch repair, DNA repair regulation, and apoptosis. We exposed X. laevis embryos to 0, 25, and 50 μg/L endosulfan or 0, 2.5, and 5.0 μg/L α-cypermethrin for 96 h, with environmentally relevant exposures of UVB radiation during the last 7 h of the 96 h exposure. We measured the amount of cyclobutane pyrimidine dimers (CPDs) and mRNA abundance of the 13 genes among treatments including control, pesticide only, UVB only, and UVB and pesticide co-exposures. Each of the co-exposure scenarios resulted in elevated CPD levels compared to UVB exposure alone, suggesting an inhibitory effect of endosulfan and α-cypermethrin on CPD repair. This is attributed to results indicating that α-cypermethrin and endosulfan reduced mRNA abundance of XPA and HR23B, respectively, to levels that may affect the initial recognition of DNA lesions. In contrast, both pesticides increased transcript abundance of CSA and MUTL. In addition, mRNA abundance of HSP70 and GADD45α were increased by endosulfan and mRNA abundance of XPG was increased by α-cypermethrin. XPC, HR23B, XPG, and GADD45α exhibited elevated mRNA concentrations whereas there was a reduction in MUTL transcript concentrations in UVB-alone treatments. It appeared that even

  13. Participation of different genes in the ruptures repair of double chain in Escherichia coli stumps exposed to gamma radiation; Participacion de diferentes genes en la reparacion de rupturas de doble cadena en cepas de Escherichia coli expuestas a radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Serment G, J. H.; Martinez M, E.; Alcantara D, D., E-mail: jorge.serment@inin.gob.mx [ININ, Departamento de Biologia, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-05-01

    All living organisms are naturally exposed to radiation from different sources. Ionizing radiation produces a plethora of lesions upon DNA that can be categorized as single and double strand breaks and base damage. Among them, unrepaired double strand breaks (Dbs) have the greatest biological significance, since they are responsible of cell death. In Escherichia coli this kind of lesions are repaired mostly by homologous recombination. In this work the participation of some recombination genes in the repair of Dbs is evaluated. Escherichia coli defective strains were exposed to gamma radiation and incubated for different periods in ideal conditions. Both micro electrophoresis and pulse field gel electrophoresis techniques were used to evaluate the kinetics of repair of such lesions, reflecting the importance of each defective gene in the process. (Author)

  14. The novel quinolone CHM-1 induces DNA damage and inhibits DNA repair gene expressions in a human osterogenic sarcoma cell line.

    Science.gov (United States)

    Chen, Hung-Yi; Lu, Hsu-Feng; Yang, Jai-Sing; Kuo, Sheng-Chu; Lo, Chyi; Yang, Mei-Due; Chiu, Tsan-Hung; Chueh, Fu-Shin; Ho, Heng-Chien; Ko, Yang-Ching; Chung, Jing-Gung

    2010-10-01

    20-Fluoro-6,7-methylenedioxy-2-phenyl-4-quino-lone (CHM-1) has been reported to induce cell cycle arrest and apoptosis in many types of cancer cells. However, there is no available information to show CHM-1 affecting DNA damage and expression of associated repair genes. Herein, we investigated whether or not CHM-1 induced DNA damage and affected DNA repair gene expression in U-2 OS human osterogenic sarcoma cells. The comet assay showed that incubation of U-2 OS cells with 0, 0.75, 1.5, 3 and 6 μM of CHM-1 led to a longer DNA migration smear (comet tail). DNA gel electrophoresis showed that 3 μM of CHM-1 for 24 and 48 h treatment induced DNA fragmentation in U-2 OS cells. Real-time PCR analysis showed that treatment with 3 μM of CHM-1 for 24 h reduced the mRNA expression levels of ataxia telangiectasia mutated (ATM), ataxia-telangiectasia and Rad3-related (ATR), breast cancer 1, early onset (BRCA1), 14-3-3sigma (14-3-3σ), DNA-dependent serine/threonine protein kinase (DNA-PK) and O(6)-methylguanine-DNA methyltransferase (MGMT) genes in a time-dependent manner. Taken together, the results indicate that CHM-1 caused DNA damage and reduced DNA repair genes in U-2 OS cells, which may be the mechanism for CHM-1-inhibited cell growth and induction of apoptosis.

  15. The human Bloom syndrome gene suppresses the DNA replication and repair defects of yeast dna2 mutants.

    Science.gov (United States)

    Imamura, Osamu; Campbell, Judith L

    2003-07-08

    Bloom syndrome is a disorder of profound and early cancer predisposition in which cells become hypermutable, exhibit high frequency of sister chromatid exchanges, and show increased micronuclei. BLM, the gene mutated in Bloom syndrome, has been cloned previously, and the BLM protein is a member of the RecQ family of DNA helicases. Many lines of evidence suggest that BLM is involved either directly in DNA replication or in surveillance during DNA replication, but its specific roles remain unknown. Here we show that hBLM can suppress both the temperature-sensitive growth defect and the DNA damage sensitivity of the yeast DNA replication mutant dna2-1. The dna2-1 mutant is defective in a helicase-nuclease that is required either to coordinate with the crucial Saccharomyces cerevisiae (sc) FEN1 nuclease in Okazaki fragment maturation or to compensate for scFEN1 when its activity is impaired. We show that human BLM interacts with both scDna2 and scFEN1 by using coimmunoprecipitation from yeast extracts, suggesting that human BLM participates in the same steps of DNA replication or repair as scFEN1 and scDna2.

  16. Inactivation of RAD52 and HDF1 DNA repair genes leads to premature chronological aging and cellular instability

    Indian Academy of Sciences (India)

    SILVIA MERCADO-SÁENZ; BEATRIZ LÓPEZ-DÍAZ; FRANCISCO SENDRA-PORTERO; MANUEL MARTÍNEZ-MORILLO; MIGUEL J RUIZ-GÓMEZ

    2017-06-01

    The present study aims to investigate the role of radiation sensitive 52 (RAD52) and high-affinity DNA binding factor1 (HDF1) DNA repair genes on the life span of budding yeasts during chronological aging. Wild type (wt) and rad52,hdf1, and rad52 hdf1 mutant Saccharomyces cerevisiae strains were used. Chronological aging and survival assayswere studied by clonogenic assay and drop test. DNA damage was analyzed by electrophoresis after phenol extraction.Mutant analysis, colony forming units and the index of respiratory competence were studied by growing on dextroseand glycerol plates as a carbon source. Rad52 and rad52 hdf1 mutants showed a gradual decrease in surviving fractionin relation to wt and hdf1 mutant during aging. Genomic DNA was spontaneously more degraded during aging,mainly in rad52 mutants. This strain showed an increased percentage of revertant colonies. Moreover, all mutantsshowed a decrease in the index of respiratory competence during aging. The inactivation of RAD52 leads to prematurechronological aging with an increase in DNA degradation and mutation frequency. In addition, RAD52 and HDF1contribute to maintain the metabolic state, in a different way, during chronological aging. The results obtained couldhave important implications in the chronobiology of aging.

  17. Distinctive adaptive response to repeated exposure to hydrogen peroxide associated with upregulation of DNA repair genes and cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Gloria A. Santa-Gonzalez

    2016-10-01

    Full Text Available Many environmental and physiological stresses are chronic. Thus, cells are constantly exposed to diverse types of genotoxic insults that challenge genome stability, including those that induce oxidative DNA damage. However, most in vitro studies that model cellular response to oxidative stressors employ short exposures and/or acute stress models. In this study, we tested the hypothesis that chronic and repeated exposure to a micromolar concentration of hydrogen peroxide (H2O2 could activate DNA damage responses, resulting in cellular adaptations. For this purpose, we developed an in vitro model in which we incubated mouse myoblast cells with a steady concentration of ~50 μM H2O2 for one hour daily for seven days, followed by a final challenge of a 10 or 20X higher dose of H2O2 (0.5 or 1 mM. We report that intermittent long-term exposure to this oxidative stimulus nearly eliminated cell toxicity and significantly decreased genotoxicity (in particular, a >5-fold decreased in double-strand breaks resulting from subsequent acute exposure to oxidative stress. This protection was associated with cell cycle arrest in G2/M and induction of expression of nine DNA repair genes. Together, this evidence supports an adaptive response to chronic, low-level oxidative stress that results in genomic protection and up-regulated maintenance of cellular homeostasis.

  18. Evolution of DNA Double-Strand Break Repair by Gene Conversion: Coevolution Between a Phage and a Restriction-Modification System

    Science.gov (United States)

    Yahara, Koji; Horie, Ryota; Kobayashi, Ichizo; Sasaki, Akira

    2007-01-01

    The necessity to repair genome damage has been considered to be an immediate factor responsible for the origin of sex. Indeed, attack by a cellular restriction enzyme of invading DNA from several bacteriophages initiates recombinational repair by gene conversion if there is homologous DNA. In this work, we modeled the interaction between a bacteriophage and a bacterium carrying a restriction enzyme as antagonistic coevolution. We assume a locus on the bacteriophage genome has either a restriction-sensitive or a restriction-resistant allele, and another locus determines whether it is recombination/repair proficient or defective. A restriction break can be repaired by a co-infecting phage genome if one of them is recombination/repair proficient. We define the fitness of phage (resistant/sensitive and repair-positive/-negative) genotypes and bacterial (restriction-positive/-negative) genotypes by assuming random encounter of the genotypes, with given probabilities of single and double infections, and the costs of resistance, repair, and restriction. Our results show the evolution of the repair allele depends on \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}b_{1}/b_{0},\\end{equation*}\\end{document} the ratio of the burst size \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}b_{1}\\end{equation*}\\end{document} under damage to host cell physiology induced by an unrepaired double-strand break to the default burst size \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage

  19. Micronuclei in humans induced by exposure to low level of ionizing radiation: influence of polymorphisms in DNA repair genes

    Energy Technology Data Exchange (ETDEWEB)

    Angelini, Sabrina [Department of Pharmacology, University of Bologna, Via Irnerio 48, Bologna 40126 (Italy) and Department of Biosciences, Karolinska Institute, Novum, Huddinge 141 57 (Sweden)]. E-mail: angelini@biocfarm.unibo.it; Kumar, Rajiv [Department of Biosciences, Karolinska Institute, Novum, Huddinge 141 57 (Sweden); Division of Molecular Genetic Epidemiology, German Cancer Research Center (DKFZ), Heidelberg (Germany); Carbone, Fabio [Department of Pharmacology, University of Bologna, Via Irnerio 48, Bologna 40126 (Italy); Maffei, Francesca [Department of Pharmacology, University of Bologna, Via Irnerio 48, Bologna 40126 (Italy); Forti, Giorgio Cantelli [Department of Pharmacology, University of Bologna, Via Irnerio 48, Bologna 40126 (Italy); Violante, Francesco Saverio [Department of Biosciences, Karolinska Institute, Novum, Huddinge 141 57 (Sweden); Occupational Medicine Unit, S. Orsola-Malpighi Hospital, Via Pelagi 9, Bologna 40100 (Italy); Lodi, Vittorio [Department of Biosciences, Karolinska Institute, Novum, Huddinge 141 57 (Sweden); Curti, Stefania [Department of Biosciences, Karolinska Institute, Novum, Huddinge 141 57 (Sweden); Hemminki, Kari [Department of Biosciences, Karolinska Institute, Novum, Huddinge 141 57 (Sweden); Hrelia, Patrizia [Department of Pharmacology, University of Bologna, Via Irnerio 48, Bologna 40126 (Italy)

    2005-02-15

    Understanding the risks deriving from protracted exposure to low doses of ionizing radiation has remarkable societal importance in view of the large number of work settings in which sources of IR are encountered. To address this question, we studied the frequency of micronuclei (MN), which is an indicator of DNA damage, in a population exposed to low levels of ionizing radiation and in matched controls. In both exposed population and controls, the possible influence of single nucleotide polymorphisms in XRCC1, XRCC3 and XPD genes on the frequency of micronuclei was also evaluated. We also considered the effects of confounding factors, like smoking status, age and gender. The results indicated that MN frequency was significantly higher in the exposed workers than in the controls [8.62 {+-} 2.80 versus 6.86 {+-} 2.65; P = 0.019]. Radiological workers with variant alleles for XRCC1 or XRCC3 polymorphisms or wild-type alleles for XPD exon 23 or 10 polymorphisms showed a significantly higher MN frequency than controls with the same genotypes. Smoking status did not affect micronuclei frequency either in exposed workers or controls, while age was associated with increased MN frequency in the exposed only. In the combined population, gender but not age exerted an influence on the yield of MN, being higher in females than in males. Even though there is a limitation in this study due to the small number of subjects, these results suggest that even exposures to low level of ionizing radiation could have genotoxic effects and that XRCC3, XRCC1 and XPD polymorphisms might contribute to the increased genetic damage in susceptible individuals occupationally exposed to chronic low levels of ionizing radiation. For a clear conclusion on the induction of DNA damage caused by protracted exposure to low doses of ionizing radiation and the possible influence of genetic polymorphism in DNA repair genes larger studies are needed.

  20. Assessing SNP-SNP interactions among DNA repair, modification and metabolism related pathway genes in breast cancer susceptibility.

    Directory of Open Access Journals (Sweden)

    Yadav Sapkota

    Full Text Available Genome-wide association studies (GWASs have identified low-penetrance common variants (i.e., single nucleotide polymorphisms, SNPs associated with breast cancer susceptibility. Although GWASs are primarily focused on single-locus effects, gene-gene interactions (i.e., epistasis are also assumed to contribute to the genetic risks for complex diseases including breast cancer. While it has been hypothesized that moderately ranked (P value based weak single-locus effects in GWASs could potentially harbor valuable information for evaluating epistasis, we lack systematic efforts to investigate SNPs showing consistent associations with weak statistical significance across independent discovery and replication stages. The objectives of this study were i to select SNPs showing single-locus effects with weak statistical significance for breast cancer in a GWAS and/or candidate-gene studies; ii to replicate these SNPs in an independent set of breast cancer cases and controls; and iii to explore their potential SNP-SNP interactions contributing to breast cancer susceptibility. A total of 17 SNPs related to DNA repair, modification and metabolism pathway genes were selected since these pathways offer a priori knowledge for potential epistatic interactions and an overall role in breast carcinogenesis. The study design included predominantly Caucasian women (2,795 cases and 4,505 controls from Alberta, Canada. We observed two two-way SNP-SNP interactions (APEX1-rs1130409 and RPAP1-rs2297381; MLH1-rs1799977 and MDM2-rs769412 in logistic regression that conferred elevated risks for breast cancer (P(interaction<7.3 × 10(-3. Logic regression identified an interaction involving four SNPs (MBD2-rs4041245, MLH1-rs1799977, MDM2-rs769412, BRCA2-rs1799943 (P(permutation = 2.4 × 10(-3. SNPs involved in SNP-SNP interactions also showed single-locus effects with weak statistical significance, while BRCA2-rs1799943 showed stronger statistical significance (P

  1. Interactive effects of ultraviolet-B radiation and pesticide exposure on DNA photo-adduct accumulation and expression of DNA damage and repair genes in Xenopus laevis embryos

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Shuangying, E-mail: shuangying.yu@ttu.edu [Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, 1207 S. Gilbert Dr., Lubbock, TX 79416 (United States); Tang, Song, E-mail: song.tang@usask.ca [Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, 1207 S. Gilbert Dr., Lubbock, TX 79416 (United States); Mayer, Gregory D., E-mail: greg.mayer@ttu.edu [Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, 1207 S. Gilbert Dr., Lubbock, TX 79416 (United States); Cobb, George P., E-mail: george_cobb@baylor.edu [Department of Environmental Science, Baylor University, One Bear Place #97266, Waco, TX 76798 (United States); Maul, Jonathan D., E-mail: jonathan.maul@ttu.edu [Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, 1207 S. Gilbert Dr., Lubbock, TX 79416 (United States)

    2015-02-15

    Highlights: • Interactive effects of UVB radiation-pesticide co-exposures were examined in frogs. • Responses included induction of DNA photo-adducts and DNA damage and repair genes. • Elevated DNA adduct levels occurred for co-exposures compared to UVB alone. • One mechanism is that pesticides may alter nuclear excision repair gene expression. - Abstract: Pesticide use and ultraviolet-B (UVB) radiation have both been suggested to adversely affect amphibians; however, little is known about their interactive effects. One potential adverse interaction could involve pesticide-induced dysregulation of DNA repair pathways, resulting in greater numbers of DNA photo-adducts from UVB exposure. In the present study, we investigated the interactive effects of UVB radiation and two common pesticides (endosulfan and α-cypermethrin) on induction of DNA photo-adducts and expression of DNA damage and repair related genes in African clawed frog (Xenopus laevis) embryos. We examined 13 genes that are, collectively, involved in stress defense, cell cycle arrest, nucleotide excision repair (NER), base excision repair, mismatch repair, DNA repair regulation, and apoptosis. We exposed X. laevis embryos to 0, 25, and 50 μg/L endosulfan or 0, 2.5, and 5.0 μg/L α-cypermethrin for 96 h, with environmentally relevant exposures of UVB radiation during the last 7 h of the 96 h exposure. We measured the amount of cyclobutane pyrimidine dimers (CPDs) and mRNA abundance of the 13 genes among treatments including control, pesticide only, UVB only, and UVB and pesticide co-exposures. Each of the co-exposure scenarios resulted in elevated CPD levels compared to UVB exposure alone, suggesting an inhibitory effect of endosulfan and α-cypermethrin on CPD repair. This is attributed to results indicating that α-cypermethrin and endosulfan reduced mRNA abundance of XPA and HR23B, respectively, to levels that may affect the initial recognition of DNA lesions. In contrast, both pesticides

  2. [The putative link between the MMR vaccine and autism and refusal to vaccinate].

    Science.gov (United States)

    Segura Benedicto, Andreu

    2012-01-01

    The paper of Wakefield et al. in The Lancet, triggered a negative reaction to the MMR vaccine, even though it was just a series of cases and the association between vaccination and autism could well be anecdotal. However, it was found that this association was spurious, not only because of hidden biases but also to alterations of the data and other improper behavior of the two authors that they were expelled from medical council. Finally, the article was removed from the magazine. This episode invites to think about the credibility and trust in the authorities and professionals to the population, as well as the suspicions that may arise when there are potential conflicts of interest among professionals, industry magazines and the population. A special area of interest is on the distorted expectations of health interventions, including vaccination, particularly with regard to both individual and collective prevention.

  3. In vivo effects of UV radiation on multiple endpoints and expression profiles of DNA repair and heat shock protein (Hsp) genes in the cycloid copepod Paracyclopina nana

    Energy Technology Data Exchange (ETDEWEB)

    Won, Eun-Ji; Han, Jeonghoon [Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Yeonjung; Kumar, K. Suresh; Shin, Kyung-Hoon [Department of Marine Sciences and Convergent Technology, College of Science and Technology, Hanyang University, Ansan 426-791 (Korea, Republic of); Lee, Su-Jae [Department of Life Sciences, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Park, Heum Gi, E-mail: hgpark@gwnu.ac.kr [Department of Marine Resource Development, College of Life Sciences, Gangneung-Wonju National University, Gangneung 210-702 (Korea, Republic of); Lee, Jae-Seong, E-mail: jslee2@skku.edu [Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-08-15

    Highlights: • UV-B radiation induced a significant reduction of the re-brooding rate of ovigerous females. • A dose-dependent decrease in food ingestion and the rate of assimilation to the body upon UV radiation. • Expression of base excision repair-associated and hsp chaperoning genes was significantly increased upon UV radiation in P. nana. - Abstract: To evaluate the effects of ultraviolet (UV) radiation on energy acquisition and consumption, the copepod Paracyclopina nana was irradiated with several doses (0–3 kJ/m{sup 2}) of UV. After UV radiation, we measured the re-brooding success, growth pattern of newly hatched nauplii, ingestion rate, and assimilation of diet. In addition, we checked the modulated patterns of DNA repair and heat shock protein (hsp) chaperoning genes of P. nana. UV-B radiation induced a significant reduction (7–87%) of the re-brooding rate of ovigerous females, indicating that UV-induced egg sac damage is closely correlated with a reduction in the hatching rate of UV-irradiated ovigerous female offspring. Using chlorophyll a and stable carbon isotope incubation experiments, we found a dose-dependent decrease (P < 0.05) in food ingestion and the rate of assimilation to the body in response to UV radiation, implying that P. nana has an underlying ability to shift its balanced-energy status from growth and reproduction to DNA repair and adaptation. Also, expression of P. nana base excision repair (BER)-associated genes and hsp chaperoning genes was significantly increased in response to UV radiation in P. nana. These findings indicate that even 1 kJ/m{sup 2} of UV radiation induces a reduction in reproduction and growth patterns, alters the physiological balance and inhibits the ability to cope with UV-induced damage in P. nana.

  4. Association between Genetic Polymorphisms of DNA Repair Genes and Chromosomal Damage for 1,3-Butadiene-Exposed Workers in a Matched Study in China

    OpenAIRE

    2015-01-01

    The aim of the study was to examine the association between polymorphisms of DNA repair genes and chromosomal damage of 1,3-butadiene- (BD-) exposed workers. The study was conducted in 45 pairs of occupationally exposed workers in a BD product workshop and matched control workers in an administrative office and a circulatory water workshop in China. Newly developed biomarkers (micronuclei, MNi; nucleoplasmic bridges, NPBs; nuclear buds, NBUDs) in the cytokinesis-blocked micronucleus (CBMN) cy...

  5. Germ line mutations of mismatch repair genes in hereditary nonpolyposis colorectal cancer patients with small bowel cancer: International Society for Gastrointestinal Hereditary Tumours Collaborative Study

    DEFF Research Database (Denmark)

    Park, Jae-Gahb; Kim, Duck-Woo; Hong, Chang Won;

    2006-01-01

    PURPOSE: The aim of study was to determine the clinical characteristics and mutational profiles of the mismatch repair genes in hereditary nonpolyposis colorectal cancer (HNPCC) patients with small bowel cancer (SBC). EXPERIMENTAL DESIGN: A questionnaire was mailed to 55 members of the Internatio.......8%, P teens. The distribution of MSH2 mutations found in patients with HNPCC-associated SBCs significantly differed from that found in the control group (P

  6. Persistence of measles antibodies, following changes in the recommended age for the second dose of MMR-vaccine in Portugal.

    Science.gov (United States)

    Gonçalves, Guilherme; Frade, João; Nunes, Carla; Mesquita, João Rodrigo; Nascimento, Maria São José

    2015-09-22

    In populations vaccinated with two doses of combined measles-mumps-rubella vaccine (MMR), the serum levels of antibodies against measles depend on the vaccination schedule, time elapsed from the last dose and the area-specific epidemiological situation. Variables measuring "schedule" are age at first and second doses of MMR and intervals derived from that. Changes in vaccination schedules have been made in Portugal. The specific objectives of this study were to measure the association between those potential determinants and the concentration of measles-specific IgG antibodies, after the second dose of MMR. Convenience samples of three Portuguese birth cohorts were selected for this study (41, 66 and 60 born, respectively, in 2001-2003, 1990-1993 and 1994-1995). Geometric mean concentrations (GMC) for measles IgG were, respectively, 934, 251 and 144mIU/ml; pmeasles-IgG serum concentration decreased with time since last vaccination (waning immunity) and was not influenced by any other component of vaccination schedule, namely age at vaccination with the second dose of MMR. Waning levels of measles antibodies have been observed elsewhere but not as fast as it was observed in Portuguese birth cohorts in this study. Changes in the vaccination schedules might have to be considered in the future.

  7. Reasons for measles cases not being vaccinated with MMR: investigation into parents' and carers' views following a large measles outbreak.

    Science.gov (United States)

    McHale, P; Keenan, A; Ghebrehewet, S

    2016-03-01

    Uptake rates for the combined measles, mumps and rubella (MMR) vaccine have been below the required 95% in the UK since a retracted and discredited article linking the MMR vaccine with autism and inflammatory bowel disease was released in 1998. This study undertook semi-structured telephone interviews among parents or carers of 47 unvaccinated measles cases who were aged between 13 months and 9 years, during a large measles outbreak in Merseyside. Results showed that concerns over the specific links with autism remain an important cause of refusal to vaccinate, with over half of respondents stating this as a reason. A quarter stated child illness during scheduled vaccination time, while other reasons included general safety concerns and access issues. Over half of respondents felt that more information or a discussion with a health professional would help the decision-making process, while a third stated improved access. There was clear support for vaccination among respondents when asked about current opinions regarding MMR vaccine. The findings support the hypothesis that safety concerns remain a major barrier to MMR vaccination, and also support previous evidence that experience of measles is an important determinant in the decision to vaccinate.

  8. Association between Genetic Polymorphisms of DNA Repair Genes and Chromosomal Damage for 1,3-Butadiene-Exposed Workers in a Matched Study in China.

    Science.gov (United States)

    Xiang, Menglong; Sun, Lei; Dong, Xiaomei; Yang, Huan; Liu, Wen-bin; Zhou, Niya; Han, Xue; Zhou, Ziyuan; Cui, Zhihong; Liu, Jing-yi; Cao, Jia; Ao, Lin

    2015-01-01

    The aim of the study was to examine the association between polymorphisms of DNA repair genes and chromosomal damage of 1,3-butadiene- (BD-) exposed workers. The study was conducted in 45 pairs of occupationally exposed workers in a BD product workshop and matched control workers in an administrative office and a circulatory water workshop in China. Newly developed biomarkers (micronuclei, MNi; nucleoplasmic bridges, NPBs; nuclear buds, NBUDs) in the cytokinesis-blocked micronucleus (CBMN) cytome assay were adopted to detect chromosomal damage. PCR and PCR-restriction fragment length polymorphism (RFLP) are adopted to analyze polymorphisms of DNA repair genes, such as X-ray repair cross-complementing Group 1 (XRCC1), O6-methylguanine-DNA methyltransferase (MGMT), poly (adenosine diphosphate-ribose) polymerases (ADPRT), and apurinic/apyrimidinic endonucleases (APE1). The BD-exposed workers exhibited increased frequencies of MNi and NPBs when compared to subjects in the control group. The results also show that the BD-exposed workers carrying XRCC1 diplotypes TCGA-CCGG (4.25 ± 2.06 ‰) (FR = 2.10, 95% CI: 1.03-4.28) and TCGG-TCGA (5.80 ± 3.56 ‰) (FR = 2.75, 95% CI: 0.76-2.65) had statistically higher NBUD frequencies than those who carried diplotype TCGG-TCGG (1.89 ± 1.27 ‰). Our study suggests that polymorphisms of XRCC1 gene may influence chromosomal damage in BD-exposed workers.

  9. In vivo effects of UV radiation on multiple endpoints and expression profiles of DNA repair and heat shock protein (Hsp) genes in the cycloid copepod Paracyclopina nana.

    Science.gov (United States)

    Won, Eun-Ji; Han, Jeonghoon; Lee, Yeonjung; Kumar, K Suresh; Shin, Kyung-Hoon; Lee, Su-Jae; Park, Heum Gi; Lee, Jae-Seong

    2015-08-01

    To evaluate the effects of ultraviolet (UV) radiation on energy acquisition and consumption, the copepod Paracyclopina nana was irradiated with several doses (0-3kJ/m(2)) of UV. After UV radiation, we measured the re-brooding success, growth pattern of newly hatched nauplii, ingestion rate, and assimilation of diet. In addition, we checked the modulated patterns of DNA repair and heat shock protein (hsp) chaperoning genes of P. nana. UV-B radiation induced a significant reduction (7-87%) of the re-brooding rate of ovigerous females, indicating that UV-induced egg sac damage is closely correlated with a reduction in the hatching rate of UV-irradiated ovigerous female offspring. Using chlorophyll a and stable carbon isotope incubation experiments, we found a dose-dependent decrease (Pnana has an underlying ability to shift its balanced-energy status from growth and reproduction to DNA repair and adaptation. Also, expression of P. nana base excision repair (BER)-associated genes and hsp chaperoning genes was significantly increased in response to UV radiation in P. nana. These findings indicate that even 1kJ/m(2) of UV radiation induces a reduction in reproduction and growth patterns, alters the physiological balance and inhibits the ability to cope with UV-induced damage in P. nana.

  10. Normal repair of ultraviolet radiation-induced DNA damage in familial melanoma without CDKN2A or CDK4 gene mutation.

    Science.gov (United States)

    Shannon, J A; Matias, C; Luxford, C; Kefford, R F; Mann, G J

    1999-04-01

    Excessive sun exposure and family history are strong risk factors for the development of cutaneous melanoma. Inherited susceptibility to this type of skin cancer could therefore result from constitutively impaired capacity to repair ultraviolet (UV)-induced DNA lesions. While a proportion of familial melanoma kindreds exhibit germline mutations in the cell cycle regulatory gene CDKN2A (p16INK4a) or its protein target, cyclin-dependent kinase 4 (CDK4), the biochemical basis of most familial melanoma is unknown. We have examined lymphoblastoid cell lines from melanoma-affected and unaffected individuals from large hereditary melanoma kindreds which are not attributable to CDKN2A or CDK4 gene mutation. These lines were tested for sensitivity of clonogenic growth to UV radiation and for their ability to repair transfected UV-damaged plasmid templates (host cell reactivation). Two of seven affected-unaffected pairs differed in colony survival after exposure to UVB radiation; however, no significant differences were observed in the host-cell reactivation assays. These results indicate that melanoma susceptibility genes other than CDKN2A and CDK4 do not impair net capacity to repair UV-induced DNA damage.

  11. Polymorphisms in DNA Repair Gene XRCC3 and Susceptibility to Breast Cancer in Saudi Females

    Directory of Open Access Journals (Sweden)

    Alaa Mohammed Ali

    2016-01-01

    Full Text Available We investigated three common polymorphisms (SNPs in the XRCC3 gene (rs861539, rs1799794, and rs1799796 in 143 Saudi females suffering from breast cancer (median age = 51.4 years and 145 age matched normal healthy controls. DNA was extracted from whole blood and genotyping was conducted using PCR-RFLP. rs1799794 showed significant association, where AA and AA+AG occurred at a significantly higher frequency in the cancer patients compared to the control group (OR: 28.1; 95% CI: 3.76–21.12; χ2: 22.82; pT and rs1799796 A>G did not show a significant difference when the results in the patients and controls were compared. However, the frequency of rs1799796 differed significantly in patients with different age of diagnosis, tumor grade, and ER and HER2 status. The wild type A allele occurred at a higher frequency in the ER− and HER2− group. Our results among Saudis suggest that some variations in XRCC3 may contribute to breast cancer susceptibility. In conclusion, the results obtained during this study suggest that rs1799794 in XRCC3 shows strong association with breast cancer development in Saudi females.

  12. Insertional Mutagenesis by CRISPR/Cas9 Ribonucleoprotein Gene Editing in Cells Targeted for Point Mutation Repair Directed by Short Single-Stranded DNA Oligonucleotides.

    Science.gov (United States)

    Rivera-Torres, Natalia; Banas, Kelly; Bialk, Pawel; Bloh, Kevin M; Kmiec, Eric B

    2017-01-01

    CRISPR/Cas9 and single-stranded DNA oligonucleotides (ssODNs) have been used to direct the repair of a single base mutation in human genes. Here, we examine a method designed to increase the precision of RNA guided genome editing in human cells by utilizing a CRISPR/Cas9 ribonucleoprotein (RNP) complex to initiate DNA cleavage. The RNP is assembled in vitro and induces a double stranded break at a specific site surrounding the mutant base designated for correction by the ssODN. We use an integrated mutant eGFP gene, bearing a single base change rendering the expressed protein nonfunctional, as a single copy target in HCT 116 cells. We observe significant gene correction activity of the mutant base, promoted by the RNP and single-stranded DNA oligonucleotide with validation through genotypic and phenotypic readout. We demonstrate that all individual components must be present to obtain successful gene editing. Importantly, we examine the genotype of individually sorted corrected and uncorrected clonally expanded cell populations for the mutagenic footprint left by the action of these gene editing tools. While the DNA sequence of the corrected population is exact with no adjacent sequence modification, the uncorrected population exhibits heterogeneous mutagenicity with a wide variety of deletions and insertions surrounding the target site. We designate this type of DNA aberration as on-site mutagenicity. Analyses of two clonal populations bearing specific DNA insertions surrounding the target site, indicate that point mutation repair has occurred at the level of the gene. The phenotype, however, is not rescued because a section of the single-stranded oligonucleotide has been inserted altering the reading frame and generating truncated proteins. These data illustrate the importance of analysing mutagenicity in uncorrected cells. Our results also form the basis of a simple model for point mutation repair directed by a short single-stranded DNA oligonucleotides and

  13. Insertional Mutagenesis by CRISPR/Cas9 Ribonucleoprotein Gene Editing in Cells Targeted for Point Mutation Repair Directed by Short Single-Stranded DNA Oligonucleotides

    Science.gov (United States)

    Rivera-Torres, Natalia; Bialk, Pawel; Bloh, Kevin M.; Kmiec, Eric B.

    2017-01-01

    CRISPR/Cas9 and single-stranded DNA oligonucleotides (ssODNs) have been used to direct the repair of a single base mutation in human genes. Here, we examine a method designed to increase the precision of RNA guided genome editing in human cells by utilizing a CRISPR/Cas9 ribonucleoprotein (RNP) complex to initiate DNA cleavage. The RNP is assembled in vitro and induces a double stranded break at a specific site surrounding the mutant base designated for correction by the ssODN. We use an integrated mutant eGFP gene, bearing a single base change rendering the expressed protein nonfunctional, as a single copy target in HCT 116 cells. We observe significant gene correction activity of the mutant base, promoted by the RNP and single-stranded DNA oligonucleotide with validation through genotypic and phenotypic readout. We demonstrate that all individual components must be present to obtain successful gene editing. Importantly, we examine the genotype of individually sorted corrected and uncorrected clonally expanded cell populations for the mutagenic footprint left by the action of these gene editing tools. While the DNA sequence of the corrected population is exact with no adjacent sequence modification, the uncorrected population exhibits heterogeneous mutagenicity with a wide variety of deletions and insertions surrounding the target site. We designate this type of DNA aberration as on-site mutagenicity. Analyses of two clonal populations bearing specific DNA insertions surrounding the target site, indicate that point mutation repair has occurred at the level of the gene. The phenotype, however, is not rescued because a section of the single-stranded oligonucleotide has been inserted altering the reading frame and generating truncated proteins. These data illustrate the importance of analysing mutagenicity in uncorrected cells. Our results also form the basis of a simple model for point mutation repair directed by a short single-stranded DNA oligonucleotides and

  14. Influence of DNA repair gene polymorphisms of hOGG1, XRCC1, XRCC3, ERCC2 and the folate metabolism gene MTHFR on chromosomal aberration frequencies.

    Science.gov (United States)

    Skjelbred, Camilla Furu; Svendsen, Marit; Haugan, Vera; Eek, Anette Kildal; Clausen, Kjell Oskar; Svendsen, Martin Veel; Hansteen, Inger-Lise

    2006-12-01

    We have studied the effect of genetic polymorphisms in the DNA repair genes hOGG1, XRCC1, XRCC3, ERCC2 and the MTHFR gene in the folate metabolism on the frequencies of cells with chromosomal aberrations (CA), chromosome-type aberrations (CSA), chromatid-type aberrations (CTA), chromatid breaks (CTB) and chromatid gaps (CTG) scored in peripheral blood lymphocytes from 651 Norwegian subjects of Caucasian descendant. DNA was extracted from fixed cell suspensions. The log-linear Poisson regression model was used for the combined data which included age, smoking, occupational exposure and genotype for 449 subjects. Our results suggest that individuals carrying the hOGG1 326Cys or the XRCC1 399Gln allele have an increased risk of chromosomal damage, while individuals carrying the XRCC1 194Trp or the ERCC2 751Gln allele have a reduced risk regardless of smoking habits and age. Individuals carrying the XRCC1 280His allele had an increased risk of CSA which was only apparent in non-smokers. This was independent of age. A protective effect of the XRCC3 241Met allele was only found in the older age group in non-smokers for CA, CSA and CTA, and in smokers for CSA. In the youngest age group, the opposite effect was found, with an increased risk for CA, CTA and CTG in smokers. Carrying the MTHFR 222Val allele gave an increased risk for chromosome and chromatid-type aberrations for both non-smokers and smokers, especially for individuals in the older age group, and with variable results in the youngest age group. The variables included in the different regression models accounted, however, for only 4-10% of the variation. The frequency ratio for CTG was significantly higher than for CTA and CTB for only 7 of the 43 comparisons performed. Some of the gap frequencies diverge from the trend in the CA, CSA, CTA and CTB results.

  15. Search for genes essential for pneumococcal transformation: the RADA DNA repair protein plays a role in genomic recombination of donor DNA.

    Science.gov (United States)

    Burghout, Peter; Bootsma, Hester J; Kloosterman, Tomas G; Bijlsma, Jetta J E; de Jongh, Christa E; Kuipers, Oscar P; Hermans, Peter W M

    2007-09-01

    We applied a novel negative selection strategy called genomic array footprinting (GAF) to identify genes required for genetic transformation of the gram-positive bacterium Streptococcus pneumoniae. Genome-wide mariner transposon mutant libraries in S. pneumoniae strain R6 were challenged by transformation with an antibiotic resistance cassette and growth in the presence of the corresponding antibiotic. The GAF screen identified the enrichment of mutants in two genes, i.e., hexA and hexB, and the counterselection of mutants in 21 different genes during the challenge. Eight of the counterselected genes were known to be essential for pneumococcal transformation. Four other genes, i.e., radA, comGF, parB, and spr2011, have previously been linked to the competence regulon, and one, spr2014, was located adjacent to the essential competence gene comFA. Directed mutants of seven of the eight remaining genes, i.e., spr0459-spr0460, spr0777, spr0838, spr1259-spr1260, and spr1357, resulted in reduced, albeit modest, transformation rates. No connection to pneumococcal transformation could be made for the eighth gene, which encodes the response regulator RR03. We further demonstrated that the gene encoding the putative DNA repair protein RadA is required for efficient transformation with chromosomal markers, whereas transformation with replicating plasmid DNA was not significantly affected. The radA mutant also displayed an increased sensitivity to treatment with the DNA-damaging agent methyl methanesulfonate. Hence, RadA is considered to have a role in recombination of donor DNA and in DNA damage repair in S. pneumoniae.

  16. Down-regulation of the Nucleotide Excision Repair gene XPG as a new mechanism of drug resistance in human and murine cancer cells

    Directory of Open Access Journals (Sweden)

    Geroni Cristina

    2010-09-01

    Full Text Available Abstract Background Drug resistance is one of the major obstacles limiting the activity of anticancer agents. Activation of DNA repair mechanism often accounts for increase resistance to cancer chemotherapy. Results We present evidence that nemorubicin, a doxorubicin derivative currently in clinical evaluation, acts through a mechanism of action different from classical anthracyclines, requiring an intact nucleotide excision repair (NER system to exert its activity. Cells made resistant to nemorubicin show increased sensitivity to UV damage. We have analysed the mechanism of resistance and discovered a previously unknown mechanism resulting from methylation-dependent silencing of the XPG gene. Restoration of NER activity through XPG gene transfer or treatment with demethylating agents restored sensitivity to nemorubicin. Furthermore, we found that a significant proportion of ovarian tumors present methylation of the XPG promoter. Conclusions Methylation of a NER gene, as described here, is a completely new mechanism of drug resistance and this is the first evidence that XPG gene expression can be influenced by an epigenetic mechanism. The reported methylation of XPG gene could be an important determinant of the response to platinum based therapy. In addition, the mechanism of resistance reported opens up the possibility of reverting the resistant phenotype using combinations with demethylating agents, molecules already employed in the clinical setting.

  17. DNA Repair Genes ERCC1 and BRCA1 Expression in Non-Small Cell Lung Cancer Chemotherapy Drug Resistance.

    Science.gov (United States)

    Wang, Shuai; Liu, Feng; Zhu, Jingyan; Chen, Peng; Liu, Hongxing; Liu, Qi; Han, Junqing

    2016-06-12

    BACKGROUND Surgery combined with chemotherapy is an important therapy for non-small cell lung cancer (NSCLC). However, chemotherapy drug resistance seriously hinders the curative effect. Studies show that DNA repair genes ERCC1 and BRCA1 are associated with NSCLC chemotherapy, but their expression and mechanism in NSCLC chemotherapy drug-resistant cells has not been elucidated. MATERIAL AND METHODS NSCLC cell line A549 and drug resistance cell line A549/DDP were cultured. Real-time PCR and Western blot analyses were used to detect ERCC1 and BRCA1 mRNA expression. A549/DDP cells were randomly divided into 3 groups: the control group; the siRNA-negative control group (scramble group); and the siRNA ERCC1 and BRCA1siRNA transfection group. Real-time PCR and Western blot analyses were used to determine ERCC1 and BRCA1 mRNA and protein expression. MTT was used to detect cell proliferation activity. Caspase 3 activity was tested by use of a kit. Western blot analysis was performed to detect PI3K, AKT, phosphorylated PI3K, and phosphorylated AKT protein expression. RESULTS ERCC1 and BRCA1 were overexpressed in A549/DDP compared with A549 (P<0.05). ERCC1 and BRCA1siRNA transfection can significantly reduce ERCC1 and BRCA1 mRNA and protein expression (P<0.05). Downregulating ERCC1 and BRCA1 expression obviously inhibited cell proliferation and increased caspase 3 activity (P<0.05). Downregulating ERCC1 and BRCA1 significantly decreased PI3K and AKT phosphorylation levels (P<0.05). CONCLUSIONS ERCC1 and BRCA1 were overexpressed in NSCLC drug-resistant cells, and they regulated lung cancer occurrence and development through the phosphorylating PI3K/AKT signaling pathway.

  18. Mismatch Repair Status and BRAF Mutation Status in Metastatic Colorectal Cancer Patients: A Pooled Analysis of the CAIRO, CAIRO2, COIN, and FOCUS Studies

    NARCIS (Netherlands)

    Venderbosch, S.; Nagtegaal, I.D.; Maughan, T.S.; Smith, C.G.; Cheadle, J.P.; Fisher, D.; Kaplan, R.; Quirke, P.; Seymour, M.T.; Richman, S.D.; Meijer, G.A.; Ylstra, B.; Heideman, D.A.; Haan, A.F.J. de; Punt, C.J.A.; Koopman, M.

    2014-01-01

    PURPOSE: To determine the prevalence and prognostic value of mismatch repair (MMR) status and its relation to BRAF mutation (BRAF(MT)) status in metastatic colorectal cancer (mCRC). EXPERIMENTAL DESIGN: A pooled analysis of four phase III studies in first-line treatment of mCRC (CAIRO, CAIRO2, COIN,

  19. Assessment of the InSiGHT Interpretation Criteria for the Clinical Classification of 24 MLH1 and MSH2 Gene Variants.

    Science.gov (United States)

    Tricarico, Rossella; Kasela, Mariann; Mareni, Cristina; Thompson, Bryony A; Drouet, Aurélie; Staderini, Lucia; Gorelli, Greta; Crucianelli, Francesca; Ingrosso, Valentina; Kantelinen, Jukka; Papi, Laura; De Angioletti, Maria; Berardi, Margherita; Gaildrat, Pascaline; Soukarieh, Omar; Turchetti, Daniela; Martins, Alexandra; Spurdle, Amanda B; Nyström, Minna; Genuardi, Maurizio

    2017-01-01

    Pathogenicity assessment of DNA variants in disease genes to explain their clinical consequences is an integral component of diagnostic molecular testing. The International Society for Gastrointestinal Hereditary Tumors (InSiGHT) has developed specific criteria for the interpretation of mismatch repair (MMR) gene variants. Here, we performed a systematic investigation of 24 MLH1 and MSH2 variants. The assessments were done by analyzing population frequency, segregation, tumor molecular characteristics, RNA effects, protein expression levels, and in vitro MMR activity. Classifications were confirmed for 15 variants and changed for three, and for the first time determined for six novel variants. Overall, based on our results, we propose the introduction of some refinements to the InSiGHT classification rules. The proposed changes have the advantage of homogenizing the InSIGHT interpretation criteria with those set out by the Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) consortium for the BRCA1/BRCA2 genes. We also observed that the addition of only few clinical data was sufficient to obtain a more stable classification for variants considered as "likely pathogenic" or "likely nonpathogenic." This shows the importance of obtaining as many as possible points of evidence for variant interpretation, especially from the clinical setting.

  20. Macrophage-specific apoE gene repair reduces diet-induced hyperlipidemia and atherosclerosis in hypomorphic Apoe mice.

    Directory of Open Access Journals (Sweden)

    Nathalie Gaudreault

    Full Text Available BACKGROUND: Apolipoprotein (apo E is best known for its ability to lower plasma cholesterol and protect against atherosclerosis. Although the liver is the major source of plasma apoE, extra-hepatic sources of apoE, including from macrophages, account for up to 10% of plasma apoE levels. This study examined the contribution of macrophage-derived apoE expression levels in diet-induced hyperlipidemia and atherosclerosis. METHODOLOGY/PRINCIPAL FINDINGS: Hypomorphic apoE (Apoe(h/h mice expressing wildtype mouse apoE at ∼2-5% of physiological levels in all tissues were derived by gene targeting in embryonic stem cells. Cre-mediated gene repair of the Apoe(h/h allele in Apoe(h/hLysM-Cre mice raised apoE expression levels by 26 fold in freshly isolated peritoneal macrophages, restoring it to 37% of levels seen in wildtype mice. Chow-fed Apoe(h/hLysM-Cre and Apoe(h/h mice displayed similar plasma apoE and cholesterol levels (55.53±2.90 mg/dl versus 62.70±2.77 mg/dl, n = 12. When fed a high-cholesterol diet (HCD for 16 weeks, Apoe(h/hLysM-Cre mice displayed a 3-fold increase in plasma apoE and a concomitant 32% decrease in plasma cholesterol when compared to Apoe(h/h mice (602.20±22.30 mg/dl versus 888.80±24.99 mg/dl, n = 7. On HCD, Apoe(h/hLysM-Cre mice showed increased apoE immunoreactivity in lesional macrophages and liver-associated Kupffer cells but not hepatocytes. In addition, Apoe(h/hLysM-Cre mice developed 35% less atherosclerotic lesions in the aortic root than Apoe(h/h mice (167×10(3±16×10(3 µm(2 versus 259×10(3±56×10(3 µm(2, n = 7. This difference in atherosclerosis lesions size was proportional to the observed reduction in plasma cholesterol. CONCLUSIONS/SIGNIFICANCE: Macrophage-derived apoE raises plasma apoE levels in response to diet-induced hyperlipidemia and by such reduces atherosclerosis proportionally to the extent to which it lowers plasma cholesterol levels.

  1. Mismatch repair genes of Streptococcus pneumoniae: HexA confers a mutator phenotype in Escherichia coli by negative complementation.

    OpenAIRE

    Prudhomme, M; Méjean, V; Martin, B; Claverys, J P

    1991-01-01

    DNA repair systems able to correct base pair mismatches within newly replicated DNA or within heteroduplex molecules produced during recombination are widespread among living organisms. Evidence that such generalized mismatch repair systems evolved from a common ancestor is particularly strong for two of them, the Hex system of the gram-positive Streptococcus pneumoniae and the Mut system of the gram-negative Escherichia coli and Salmonella typhimurium. The homology existing between HexA and ...

  2. Minor Changes in Expression of the Mismatch Repair Protein MSH2 Exert a Major Impact on Glioblastoma Response to Temozolomide.

    Science.gov (United States)

    McFaline-Figueroa, José L; Braun, Christian J; Stanciu, Monica; Nagel, Zachary D; Mazzucato, Patrizia; Sangaraju, Dewakar; Cerniauskas, Edvinas; Barford, Kelly; Vargas, Amanda; Chen, Yimin; Tretyakova, Natalia; Lees, Jacqueline A; Hemann, Michael T; White, Forest M; Samson, Leona D

    2015-08-01

    Glioblastoma (GBM) is often treated with the cytotoxic drug temozolomide, but the disease inevitably recurs in a drug-resistant form after initial treatment. Here, we report that in GBM cells, even a modest decrease in the mismatch repair (MMR) components MSH2 and MSH6 have profound effects on temozolomide sensitivity. RNAi-mediated attenuation of MSH2 and MSH6 showed that such modest decreases provided an unexpectedly strong mechanism of temozolomide resistance. In a mouse xenograft model of human GBM, small changes in MSH2 were sufficient to suppress temozolomide-induced tumor regression. Using The Cancer Genome Atlas to analyze mRNA expression patterns in tumors from temozolomide-treated GBM patients, we found that MSH2 transcripts in primary GBM could predict patient responses to initial temozolomide therapy. In recurrent disease, the absence of microsatellite instability (the standard marker for MMR deficiency) suggests a lack of involvement of MMR in the resistant phenotype of recurrent disease. However, more recent studies reveal that decreased MMR protein levels occur often in recurrent GBM. In accordance with our findings, these reported decreases may constitute a mechanism by which GBM evades temozolomide sensitivity while maintaining microsatellite stability. Overall, our results highlight the powerful effects of MSH2 attenuation as a potent mediator of temozolomide resistance and argue that MMR activity offers a predictive marker for initial therapeutic response to temozolomide treatment.

  3. H. pylori-Induced DNA Strand Breaks Are Introduced by Nucleotide Excision Repair Endonucleases and Promote NF-κB Target Gene Expression

    Directory of Open Access Journals (Sweden)

    Mara L. Hartung

    2015-10-01

    Full Text Available The human bacterial pathogen Helicobacter pylori exhibits genotoxic properties that promote gastric carcinogenesis. H. pylori introduces DNA double strand breaks (DSBs in epithelial cells that trigger host cell DNA repair efforts. Here, we show that H. pylori-induced DSBs are repaired via error-prone, potentially mutagenic non-homologous end-joining. A genome-wide screen for factors contributing to DSB induction revealed a critical role for the H. pylori type IV secretion system (T4SS. Inhibition of transcription, as well as NF-κB/RelA-specific RNAi, abrogates DSB formation. DSB induction further requires β1-integrin signaling. DSBs are introduced by the nucleotide excision repair endonucleases XPF and XPG, which, together with RelA, are recruited to chromatin in a highly coordinated, T4SS-dependent manner. Interestingly, XPF/XPG-mediated DNA DSBs promote NF-κB target gene transactivation and host cell survival. In summary, H. pylori induces XPF/XPG-mediated DNA damage through activation of the T4SS/β1-integrin signaling axis, which promotes NF-κB target gene expression and host cell survival.

  4. Comprehensive SNP scan of DNA repair and DNA damage response genes reveal multiple susceptibility loci conferring risk to tobacco associated leukoplakia and oral cancer.

    Science.gov (United States)

    Mondal, Pinaki; Datta, Sayantan; Maiti, Guru Prasad; Baral, Aradhita; Jha, Ganga Nath; Panda, Chinmay Kumar; Chowdhury, Shantanu; Ghosh, Saurabh; Roy, Bidyut; Roychoudhury, Susanta

    2013-01-01

    Polymorphic variants of DNA repair and damage response genes play major role in carcinogenesis. These variants are suspected as predisposition factors to Oral Squamous Cell Carcinoma (OSCC). For identification of susceptible variants affecting OSCC development in Indian population, the "maximally informative" method of SNP selection from HapMap data to non-HapMap populations was applied. Three hundred twenty-five SNPs from 11 key genes involved in double strand break repair, mismatch repair and DNA damage response pathways were genotyped on a total of 373 OSCC, 253 leukoplakia and 535 unrelated control individuals. The significantly associated SNPs were validated in an additional cohort of 144 OSCC patients and 160 controls. The rs12515548 of MSH3 showed significant association with OSCC both in the discovery and validation phases (discovery P-value: 1.43E-05, replication P-value: 4.84E-03). Two SNPs (rs12360870 of MRE11A, P-value: 2.37E-07 and rs7003908 of PRKDC, P-value: 7.99E-05) were found to be significantly associated only with leukoplakia. Stratification of subjects based on amount of tobacco consumption identified SNPs that were associated with either high or low tobacco exposed group. The study reveals a synergism between associated SNPs and lifestyle factors in predisposition to OSCC and leukoplakia.

  5. Mice with DNA repair gene Ercc1 deficiency in a neural crest lineage are a model for late-onset Hirschsprung disease.

    Science.gov (United States)

    Selfridge, Jim; Song, Liang; Brownstein, David G; Melton, David W

    2010-06-04

    The Ercc1 gene is essential for nucleotide excision repair and is also important in recombination repair and the repair of interstrand crosslinks. We have previously used a floxed Ercc1 allele with a keratinocyte-specific Cre recombinase transgene to inactivate Ercc1 in the epidermal layer of the skin and so generate a mouse model for UV-induced non-melanoma skin cancer. Now, in an attempt to generate a model for UV-induced melanoma, we have used the floxed Ercc1 allele in combination with a Cre transgene under the control of the tyrosinase gene promoter to produce mice with Ercc1-deficient melanocytes that are hypersensitive to UV irradiation. These animals developed normally, but died when 4-6 months old with severe colonic obstruction. Melanocytes are derived from the neural crest and the tyrosinase promoter is also expressed in additional neural crest-derived lineages, including the progenitors of the parasympathetic nervous system that innervates the gastrointestinal tract and controls gut peristalsis. A functional enteric nervous system developed in floxed Ercc1 mice with the tyrosinase Cre transgene, but was found to have degenerated in the colons of affected mice. We suggest that accumulating unrepaired endogenous DNA damage in the Ercc1-deficient colonic parasympathetic ganglia leads to the degeneration of this network and results in a colonic obstructive disorder that resembles late-onset Hirschsprung disease in man.

  6. [Photoreactivating Activity of Bioluminescence: Repair of UV-damaged DNA of Escherichia coli Occurs with Assistance of lux-Genes of Marine Bacteria].

    Science.gov (United States)

    Zavilgelsky, G B; Melkina, O E; Kotova, V Yu; Konopleva, M N; Manukhov, I V; Pustovoit, K Ss

    2015-01-01

    The UV resistance of luminescent bacteria Escherichia coli AB1886 uvrA6 (pLeo1) containing the plasmid with luxCDABE genes of marine bacteria Photobacterium leiognathi is approximately two times higher than the UV resistance of non-luminous bacteria E. coli AB1886 uvrA6. Introduction of phr::kan(r) mutations (a defect in the functional activity of photolyase) into the genome of E. coli AB1886 uvrA6 (pLeo1) completely removes the high UV resistance of the cells. Therefore, photoreactivation that involves bacterial photolyase contributes mainly to the bioluminescence-induced DNA repair. It is shown that photoreactivating activity of bioluminescence of P. leiognathi is about 2.5 times lower compared with that one induced by a light source with λ > 385 nm. It is also shown that an increase in the bioluminescence intensity, induced by UV radiation in E. coli bacterial cells with a plasmid containing the luxCD ABE genes under RecA-LexA-regulated promoters, occurs only 25-30 min later after UV irradiation of cells and does not contribute to DNA repair. A quorum sensing regulatory system is not involved in the DNA repair by photolyase.

  7. Polymorphisms in XPC, XPD, XRCC1, and XRCC3 DNA repair genes and lung cancer risk in a population of Northern Spain

    Directory of Open Access Journals (Sweden)

    Tardón Adonina

    2007-08-01

    Full Text Available Abstract Background Polymorphisms in DNA repair genes have been associated to repair DNA lesions, and might contribute to the individual susceptibility to develop different types of cancer. Nucleotide excision repair (NER, base excision repair (BER, and double-strand break repair (DSBR are the main DNA repair pathways. We investigated the relationship between polymorphisms in two NER genes, XPC (poly (AT insertion/deletion: PAT-/+ and XPD (Asp312Asn and Lys751Gln, the BER gene XRCC1 (Arg399Gln, and the DSBR gene XRCC3 (Thr241Met and the risk of developing lung cancer. Methods A hospital-based case-control study was designed with 516 lung cancer patients and 533 control subjects, matched on ethnicity, age, and gender. Genotypes were determined by PCR-RFLP and the results were analysed using multivariate unconditional logistic regression, adjusting for age, gender and pack-years. Results Borderline association was found for XPC and XPD NER genes polymorphisms, while no association was observed for polymorphisms in BER and DSBR genes. XPC PAT+/+ genotype was associated with no statistically significant increased risk among ever smokers (OR = 1.40; 95%CI = 0.94–2.08, squamous cell carcinoma (OR = 1.44; 95%CI = 0.85–2.44, and adenocarcinoma (OR = 1.72; 95%CI = 0.97–3.04. XPD variant genotypes (312Asn/Asn and 751Gln/Gln presented a not statistically significant risk of developing lung cancer (OR = 1.52; 95%CI = 0.91–2.51; OR = 1.38; 95%CI = 0.85–2.25, respectively, especially among ever smokers (OR = 1.58; 95%CI = 0.96–2.60, heavy smokers (OR = 2.07; 95%CI = 0.74–5.75, and adenocarcinoma (OR = 1.88; 95%CI = 0.97–3.63. On the other hand, individuals homozygous for the XRCC1 399Gln allele presented no risk of developing lung cancer (OR = 0.87; 95%CI = 0.57–1.31 except for individuals carriers of 399Gln/Gln genotype and without family history of cancer (OR = 0.57; 95%CI = 0.33–0.98 and no association was found between XRCC3 Thr241Met

  8. Removal of nonhomologous DNA ends in double-strand break recombination: The role of the yeast ultraviolet repair gene RAD1

    Energy Technology Data Exchange (ETDEWEB)

    Fishman-Lobell, J.; Habert, J.E. (Brandeis Univ., Waltham, MA (United States))

    1992-10-15

    Double-strand breaks (DSBs) in Saccharomyces cerevisiae can be repaired by gene conversions or by deletions resulting from single-strand annealing between direct repeats of homologous sequences. Although rad1 mutants are resistant to x-rays and can complete DSB-mediated mating-type switching, they could not complete recombination when the ends of the break contained approximately 60 base pairs of nonhomology. Recombination was restored when the ends of the break were made homologous to donor sequences. Additionally, the absence of RAD1 led to the frequent appearance of a previously unobserved type of recombination product. These data suggest RAD1 is required to remove nonhomologous DNA from the 3{prime} ends of recombining DNA, a process analogous to the excision of photodimers during repair of ultraviolet-damaged DNA.

  9. Inducible Apoe Gene Repair in Hypomorphic ApoE Mice Deficient in the LDL Receptor Promotes Atheroma Stabilization with a Human-like Lipoprotein Profile

    Science.gov (United States)

    Eberlé, Delphine; Luk, Fu Sang; Kim, Roy Y.; Olivas, Victor R.; Kumar, Nikit; Posada, Jessica M.; Li, Kang; Gaudreault, Nathalie; Rapp, Joseph H.; Raffai, Robert L.

    2013-01-01

    Objective To study atherosclerosis regression in mice following plasma lipid reduction to moderately elevated apolipoprotein B (apoB)-lipoprotein levels. Approach and Results Chow-fed hypomorphic Apoe mice deficient in LDL receptor expression (Apoeh/hLdlr−/−Mx1-cre mice) develop hyperlipidemia and atherosclerosis. These mice were studied before and after inducible cre-mediated Apoe gene repair. By 1 week, induced mice displayed a 2-fold reduction in plasma cholesterol and triglyceride levels and a decrease in the non-HDL:HDL-cholesterol ratio from 87%:13% to 60%:40%. This halted atherosclerotic lesion growth and promoted macrophage loss and accumulation of thick collagen fibers for up to 8 weeks. Concomitantly, blood Ly-6Chi monocytes were decreased by 2-fold but lesional macrophage apoptosis was unchanged. The expression of several genes involved in extra-cellular matrix remodeling and cell migration were changed in lesional macrophages 1 week after Apoe gene repair. However, mRNA levels of numerous genes involved in cholesterol efflux and inflammation were not significantly changed at this time point. Conclusions Restoring apoE expression in Apoeh/hLdlr−/−Mx1-cre mice resulted in lesion stabilization in the context of a human-like ratio of non-HDL:HDL-cholesterol. Our data suggest that macrophage loss derived in part from reduced blood Ly-6Chi monocytes levels and genetic reprogramming of lesional macrophages. PMID:23788760

  10. Tendon repair

    Science.gov (United States)

    Repair of tendon ... Tendon repair can be performed using: Local anesthesia (the immediate area of the surgery is pain-free) ... a cut on the skin over the injured tendon. The damaged or torn ends of the tendon ...

  11. International congress on DNA damage and repair: Book of abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    This document contains the abstracts of 105 papers presented at the Congress. Topics covered include the Escherichia coli nucleotide excision repair system, DNA repair in malignant transformations, defective DNA repair, and gene regulation. (TEM)

  12. Biological Augmentation of Rotator Cuff Tendon Repair

    National Research Council Canada - National Science Library

    Kovacevic, David; Rodeo, Scott A

    2008-01-01

    A histologically normal insertion site does not regenerate following rotator cuff tendon-to-bone repair, which is likely due to abnormal or insufficient gene expression and/or cell differentiation at the repair site...

  13. [Effects of the MMR vaccination on the epidemiology of mumps in Germany].

    Science.gov (United States)

    Koch, J; Takla, A

    2013-09-01

    Mumps is an acute viral infectious disease characterized by fever and swelling and tenderness of one or more salivary glands, usually the parotid gland. Since 1976, the German Standing Committee on Vaccination (STIKO) has recommended a mumps vaccination as part of the routine immunization schedule in former West Germany. In East Germany, the vaccination was only introduced in 1991 after reunification. In the preceding decades, no comprehensive surveillance system existed in Germany. However, for East Germany and the successional federal states of former East Germany, data on mumps incidence are available from different Eastern surveillance systems for the time period 1968-2012. According to these data, the incidence of mumps has dropped from > 200 cases/100,000 annually in the pre-vaccine era to currently epidemiology and the increase of outbreaks among adolescents and young adults, the implementation of a nationwide mandatory notification was initiated and came into effect in March 2013. Mandatory notification enables the early detection of outbreaks and obtainment of comprehensive data for evaluation of the immunization program in place. Regarding the long-term prevention of mumps in Germany, it is hoped that--as part of the measles and rubella elimination effort--coverage rates for the second MMR dose among children will increase nationwide above 95% and existing vaccination gaps among adults will be closed.

  14. Dilemmas of a vitalizing vaccine market: lessons from the MMR vaccine/autism debate.

    Science.gov (United States)

    Bragesjö, Fredrik; Hallberg, Margareta

    2011-03-01

    A number of issues related to vaccines and vaccinations in society are discussed in this paper. Our purpose is to merge an analysis of some recent changes in the vaccine market with social science research on the relationship between citizens and authorities. The article has two empirical parts. The first shows how the vaccine market, which for many years has had immense financial problems, nowadays seems to becoming economically vitalized, mostly due to the production of new and profitable vaccines. However prosperous the future may appear, certain reactions from the public regarding vaccination initiatives offer insight into inherent problems of vaccine policies in many Western countries. In the second part of the article, these problems are exemplified with the recent controversy over the MMR (measles, mumps, and rubella) vaccine. We conclude that in spite of the improving profit-margins, the vaccine market remains vulnerable and insecure. Vaccines are permeated by society, even more so than pharmaceutics that are used to cure or alleviate illnesses. Radical changes in financial conditions with promises of a more profitable market will not, we argue, solve other even more fundamental problems.

  15. Turbomachinery Performance Map Application for Analyzing Cycle Off-Design Behavior of KAIST MMR

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Seong Kuk; Lee, Jekyoung; Kim, Seong Gu; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    The steam Rankine cycle has been mainly applied in the Power Conversion Unit (PCU) of the existing SMRs. For this reason, modularization and downsizing of the nuclear power plant including PCU is difficult due to complexity and large volume. To solve these problems, KAIST research team proposed a new concept of SMR, called KAIST MMR (Micro Modular Reactor), which utilizes S-CO2 as the working fluid. Due to high density of S-CO2 and the development of heat exchanger technology, such as the printed circuit heat exchanger (PCHE), it can achieve small PCU and modularization of system. This paper describes the method of performance maps to predict the turbomachinery performance for different inlet conditions. One of the most well-known methods is equivalent conditions which include corrected mass flow, corrected total enthalpy rise, and corrected speed. Appropriate performance at any conditions which are different from the design condition can be calculated. As further works, the predicted data from KAIST{sub T}MD will be compared to other experimental data. Also turbine code will be validated.

  16. Timely MMR vaccination in infancy: influence of attitudes and medical advice on the willingness to vaccinate.

    Science.gov (United States)

    Schönberger, K; Ludwig, M-S; Wildner, M; Kalies, H

    2012-11-01

    In light of the failure to eliminate measles by 2010, the closure of any gaps in immunisation coverage is of paramount importance to interrupt transmission and to protect vulnerable individuals. Not only vaccination-critical attitudes of parents but furthermore the medical advice by physician in charge influence the vaccine uptake. 3 groups of factors which potentially influence parental decisions on child vaccination were analysed by univariable and multivariable logistic regression for the timely uptake of the first and the second dose of measles vaccination: parents' attitudes towards immunization, the influence of medical and laypersons and the influence of the advice of a medical doctor. A total of 3 041 children were eligible for the analysis. 53.0% of these received the first and 42.9% the second MMR dose in time. If parents considered that vaccinations are important and protective as well as the consulted physician advices towards vaccinations, children had significantly higher chances of a timely vaccination. Whereas, if parents were afraid of vaccinations or get advised by an alternative practitioner, the children had lower chances of being vaccinated in time. If medical providers help parents to reduce uncertainties about vaccination the chance for children to be vaccinated in time increased. It appeared that there still are unmet information needs after the medical consultation. By and large the medical advice plays an important role for vaccination uptake and its timing. In order to raise the vaccination rates further target-population specific approaches are needed.

  17. Using electronic mail to improve MMR uptake amongst third level students.

    LENUS (Irish Health Repository)

    Cooney, F

    2010-03-01

    This study assessed the usefulness of email in informing third level students about special MMR clinics being provided on campus during a mumps outbreak in the North West of Ireland. Email messages were sent directly to students, informing them of the clinics, inviting them to make a clinic appointment by email and providing details of walk-in clinics. At the clinics, all 177 attendees were asked to fill out a questionnaire and the response rate was 89% (n=158). Regarding the main sources of information about the vaccination clinics, email was selected by 117 (74%) students, word-of-mouth by 27 (17%), posters\\/leaflets by 8 (5%), and other sources by 6 (4%). Use of email as a source of information was rated as very good\\/excellent by 115 (73%), as good by 35 (22%) and poor\\/fair by 8 (5%). This study demonstrates that email is a useful and acceptable way of informing third level students about immunisation clinics in an outbreak situation.

  18. Using electronic mail to improve MMR uptake amongst third level students.

    Science.gov (United States)

    Cooney, F; Ryan, A; Schinaia, N; Breslin, A

    2010-03-01

    This study assessed the usefulness of email in informing third level students about special MMR clinics being provided on campus during a mumps outbreak in the North West of Ireland. Email messages were sent directly to students, informing them of the clinics, inviting them to make a clinic appointment by email and providing details of walk-in clinics. At the clinics, all 177 attendees were asked to fill out a questionnaire and the response rate was 89% (n=158). Regarding the main sources of information about the vaccination clinics, email was selected by 117 (74%) students, word-of-mouth by 27 (17%), posters/leaflets by 8 (5%), and other sources by 6 (4%). Use of email as a source of information was rated as very good/excellent by 115 (73%), as good by 35 (22%) and poor/fair by 8 (5%). This study demonstrates that email is a useful and acceptable way of informing third level students about immunisation clinics in an outbreak situation.

  19. Healthcare workers and measles-mumps-rubella (MMR) status: how worried should we be about further outbreaks?

    Science.gov (United States)

    Basu, S; Giri, P; Adisesh, A; McNAUGHT, R

    2014-08-01

    Recently, a number of outbreaks of measles and mumps have occurred within the UK and Europe. Healthcare workers (HCWs) are at risk of contracting and transmitting disease to patients and staff. To examine this risk at the point of entry to healthcare, we assessed the serological results of new HCWs presenting for pre-placement clearance without evidence of measles-mumps-rubella (MMR) immunity between 1 April 2010 and 31 March 2012. Overall rates of serological positivity to MMR across all age groups were 88·2%, 68·8% and 93·9%, respectively. With regard to measles and mumps, there were statistically significant decreases in the percentage of HCWs born after 1980 that had positive serology (P outbreak within this cohort of HCWs appears low.

  20. Deoxyribonucleic acid repair gene X-ray repair cross-complementing group 1 polymorphisms and non-carcinogenic disease risk in different populations: A meta-analysis

    Directory of Open Access Journals (Sweden)

    Bagher Larijani

    2013-01-01

    Full Text Available Purpose: This study aims to assess a meta-analysis of the association of X-ray repair cross-complementing group 1 (XRCC1 polymorphisms with the risk of various non-carcinogenic diseases in different population. Materials and Methods: This meta-analysis was performed by critically reviewing reveals 38 studies involving 10043 cases and 11037 controls. Among all the eligible studies, 14 focused on Arg194Trp polymorphism, 33 described the Arg399Gln and three articles investigated on Arg280His. Populations were divided into three different ethnic subgroups include Caucasians, Asians and other (Turkish and Iranian. Results: Pooled results showed no correlation between Arg194Trp and non-carcinogenic disease. There was only weak relation in the recessive (odds ratio [OR] =1.11, 95% confidence interval [CI]: 0.86-1.44 model in Asian population and dominant (OR = 1.04, 95% CI: 0.66-1.63 model of other populations. In Arg399Gln polymorphism, there was no relation with diseases of interest generally. In the pooled analysis, there were weak relation in the dominant (OR = 1.08, 95% CI: 0.86-1.35 model of Asian population and quite well-correlation with recessive (OR = 1.49, 95% CI: 1.19-1.88, dominant (OR = 1.23, 95% CI: 0.94-1.62, and additive (OR = 1.23, 95% CI: 0.94-1.62 models of other subgroup. For Arg280His, there was a weak relation only in the dominant model (OR = 1.06, 95% CI: 0.74-1.51. Conclusion: The present meta-analysis correspondingly shows that Arg399Gln variant to be associated with increased non-carcinogenic diseases risk through dominant and recessive modes among Iranian and Turkish population. It also suggests a trend of dominant and recessive effect of Arg280His variant in all population and its possible protective effect on non-carcinogenic diseases.

  1. MSH3 mismatch repair protein regulates sensitivity to cytotoxic drugs and a histone deacetylase inhibitor in human colon carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Jae Myung Park

    Full Text Available BACKGROUND: MSH3 is a DNA mismatch repair (MMR gene that undergoes frequent somatic mutation in colorectal cancers (CRCs with MMR deficiency. MSH3, together with MSH2, forms the MutSβ heteroduplex that interacts with interstrand cross-links induced by drugs such as cisplatin. To date, the impact of MSH3 on chemosensitivity is unknown. METHODS: We utilized isogenic HCT116 (MLH1-/MSH3- cells where MLH1 is restored by transfer of chromosome 3 (HCT116+ch3 and also MSH3 by chromosome 5 (HCT116+3+5. We generated HCT116+3+5, SW480 (MLH1+/MSH3+ and SW48 (MLH1-/MSH3+ cells with shRNA knockdown of MSH3. Cells were treated with 5-fluorouracil (5-FU, SN-38, oxaliplatin, or the histone deacetylase (HDAC inhibitor PCI-24781 and cell viability, clonogenic survival, DNA damage and apoptosis were analyzed. RESULTS: MSH3-deficient vs proficient CRC cells showed increased sensitivity to the irinotecan metabolite SN-38 and to oxaliplatin, but not 5-FU, as shown in assays for apoptosis and clonogenic survival. In contrast, suppression of MLH1 attenuated the cytotoxic effect of 5-FU, but did not alter sensitivity to SN-38 or oxaliplatin. The impact of MSH3 knockdown on chemosensitivity to SN-38 and oxaliplatin was maintained independent of MLH1 status. In MSH3-deficient vs proficient cells, SN-38 and oxaliplatin induced higher levels of phosphorylated histone H2AX and Chk2, and similar results were found in MLH1-proficient SW480 cells. MSH3-deficient vs proficient cells showed increased 53BP1 nuclear foci after irradiation, suggesting that MSH3 can regulate DNA double strand break (DSB repair. We then utilized PCI-24781 that interferes with homologous recombination (HR indicated by a reduction in Rad51 expression. The addition of PCI-24781 to oxaliplatin enhanced cytotoxicity to a greater extent compared to either drug alone. CONCLUSION: MSH3 status can regulate the DNA damage response and extent of apoptosis induced by chemotherapy. The ability of MSH3 to regulate

  2. Association between Genetic Polymorphisms of DNA Repair Genes and Chromosomal Damage for 1,3-Butadiene-Exposed Workers in a Matched Study in China

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    Menglong Xiang

    2015-01-01

    Full Text Available The aim of the study was to examine the association between polymorphisms of DNA repair genes and chromosomal damage of 1,3-butadiene- (BD- exposed workers. The study was conducted in 45 pairs of occupationally exposed workers in a BD product workshop and matched control workers in an administrative office and a circulatory water workshop in China. Newly developed biomarkers (micronuclei, MNi; nucleoplasmic bridges, NPBs; nuclear buds, NBUDs in the cytokinesis-blocked micronucleus (CBMN cytome assay were adopted to detect chromosomal damage. PCR and PCR-restriction fragment length polymorphism (RFLP are adopted to analyze polymorphisms of DNA repair genes, such as X-ray repair cross-complementing Group 1 (XRCC1, O6-methylguanine-DNA methyltransferase (MGMT, poly (adenosine diphosphate-ribose polymerases (ADPRT, and apurinic/apyrimidinic endonucleases (APE1. The BD-exposed workers exhibited increased frequencies of MNi and NPBs when compared to subjects in the control group. The results also show that the BD-exposed workers carrying XRCC1 diplotypes TCGA-CCGG (4.25±2.06‰ (FR=2.10, 95% CI: 1.03–4.28 and TCGG-TCGA (5.80±3.56‰ (FR=2.75, 95% CI: 0.76–2.65 had statistically higher NBUD frequencies than those who carried diplotype TCGG-TCGG (1.89±1.27‰. Our study suggests that polymorphisms of XRCC1 gene may influence chromosomal damage in BD-exposed workers.

  3. Identification and Analysis of MS5(d): A Gene That Affects Double-Strand Break (DSB) Repair during Meiosis I in Brassica napus Microsporocytes.

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    Zeng, Xinhua; Yan, Xiaohong; Yuan, Rong; Li, Keqi; Wu, Yuhua; Liu, Fang; Luo, Junling; Li, Jun; Wu, Gang

    2016-01-01

    Here, we report the identification of the Brassica-specific gene MS5(d), which is responsible for male sterility in Brassica napus. The MS5(d) gene is highly expressed in the microsporocyte and encodes a protein that localizes to the nucleus. Light microscopy analyses have demonstrated that the MS5(d) gene affects microsporocyte meiosis in the thermosensitive genic male sterility line TE5A. Sequence comparisons and genetic complementation revealed a C-to-T transition in MS5(d), encoding a Leu-to-Phe (L281F) substitution and causing abnormal male meiosis in TE5A. These findings suggest arrested meiotic chromosome dynamics at pachytene. Furthermore, immunofluorescence analyses showed that double-strand break (DSB) formation and axial elements were normal but that DSB repair and spindle behavior were aberrant in TE5A meiocytes. Collectively, our results indicate that MS5(d) likely encodes a protein required for chromosomal DSB repair at early stages of meiosis in B. napus.

  4. FANCJ localization by mismatch repair is vital to maintain genomic integrity after UV irradiation.

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    Guillemette, Shawna; Branagan, Amy; Peng, Min; Dhruva, Aashana; Schärer, Orlando D; Cantor, Sharon B

    2014-02-01

    Nucleotide excision repair (NER) is critical for the repair of DNA lesions induced by UV radiation, but its contribution in replicating cells is less clear. Here, we show that dual incision by NER endonucleases, including XPF and XPG, promotes the S-phase accumulation of the BRCA1 and Fanconi anemia-associated DNA helicase FANCJ to sites of UV-induced damage. FANCJ promotes replication protein A phosphorylation and the arrest of DNA synthesis following UV irradiation. Interaction defective mutants of FANCJ reveal that BRCA1 binding is not required for FANCJ localization, whereas interaction with the mismatch repair (MMR) protein MLH1 is essential. Correspondingly, we find that FANCJ, its direct interaction with MLH1, and the MMR protein MSH2 function in a common pathway in response to UV irradiation. FANCJ-deficient cells are not sensitive to killing by UV irradiation, yet we find that DNA mutations are significantly enhanced. Thus, we considered that FANCJ deficiency could be associated with skin cancer. Along these lines, in melanoma we found several somatic mutations in FANCJ, some of which were previously identified in hereditary breast cancer and Fanconi anemia. Given that, mutations in XPF can also lead to Fanconi anemia, we propose collaborations between Fanconi anemia, NER, and MMR are necessary to initiate checkpoint activation in replicating human cells to limit genomic instability.

  5. The Rate and Spectrum of Spontaneous Mutations in Mycobacterium smegmatis, a Bacterium Naturally Devoid of the Postreplicative Mismatch Repair Pathway

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    Sibel Kucukyildirim

    2016-07-01

    Full Text Available Mycobacterium smegmatis is a bacterium that is naturally devoid of known postreplicative DNA mismatch repair (MMR homologs, mutS and mutL, providing an opportunity to investigate how the mutation rate and spectrum has evolved in the absence of a highly conserved primary repair pathway. Mutation accumulation experiments of M. smegmatis yielded a base-substitution mutation rate of 5.27 × 10−10 per site per generation, or 0.0036 per genome per generation, which is surprisingly similar to the mutation rate in MMR-functional unicellular organisms. Transitions were found more frequently than transversions, with the A:T→G:C transition rate significantly higher than the G:C→A:T transition rate, opposite to what is observed in most studied bacteria. We also found that the transition-mutation rate of M. smegmatis is significantly lower than that of other naturally MMR-devoid or MMR-knockout organisms. Two possible candidates that could be responsible for maintaining high DNA fidelity in this MMR-deficient organism are the ancestral-like DNA polymerase DnaE1, which contains a highly efficient DNA proofreading histidinol phosphatase (PHP domain, and/or the existence of a uracil-DNA glycosylase B (UdgB homolog that might protect the GC-rich M. smegmatis genome against DNA damage arising from oxidation or deamination. Our results suggest that M. smegmatis has a noncanonical Dam (DNA adenine methylase methylation system, with target motifs differing from those previously reported. The mutation features of M. smegmatis provide further evidence that genomes harbor alternative routes for improving replication fidelity, even in the absence of major repair pathways.

  6. Radio-adaptive response of base excision repair genes and proteins in human peripheral blood mononuclear cells exposed to gamma radiation.

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    Toprani, Sneh M; Das, Birajalaxmi

    2015-09-01

    Radio-adaptive response is a mechanism whereby a low-dose exposure (priming dose) induces resistance to a higher dose (challenging dose) thus significantly reducing its detrimental effects. Radiation-induced DNA damage gets repaired through various DNA repair pathways in human cells depending upon the type of lesion. The base excision repair (BER) pathway repairs radiation-induced base damage, abasic sites and single-strand breaks in cellular DNA. In the present study, an attempt has been made to investigate the involvement of BER genes and proteins in the radio-adaptive response in human resting peripheral blood mononuclear cells (PBMC). Venous blood samples were collected from 20 randomly selected healthy male individuals with written informed consent. PBMC were isolated and irradiated at a priming dose of 0.1 Gy followed 4h later with a challenging dose of 2.0 Gy (primed cells). Quantitation of DNA damage was done using the alkaline comet assay immediately and expression profile of BER genes and proteins were studied 30 min after the challenging dose using real-time quantitative polymerase chain reaction and western blot, respectively. The overall result showed significant (P ≤ 0.05) reduction of DNA damage in terms of percentage of DNA in tail (%T) with a priming dose of 0.1 Gy followed by a challenging dose of 2.0 Gy after 4 h. Twelve individuals showed significant (P ≤ 0.05) reduction in %T whereas eight individuals showed marginal reduction in DNA damage that was not statistically significant. However, at the transcriptional level, BER genes such as APE1, FEN1 and LIGASE1 showed significant (P ≤ 0.05) up-regulation in both groups. Significant (P ≤ 0.05) up-regulation was also observed at the protein level for OGG1, APE1, MBD4, FEN1 and LIGASE1 in primed cells. Up-regulation of some BER genes and proteins such as APE1, FEN1 and LIGASE1 in primed cells of resting PBMC is suggestive of active involvement of the BER pathway in radio-adaptive response.

  7. Integration of principles of systems biology and radiation biology: toward development of in silico models to optimize IUdR-mediated radiosensitization of DNA mismatch repair-deficient (damage tolerant human cancers

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    Timothy James Kinsella

    2011-08-01

    Full Text Available Over the last 7 years, we have focused our experimental and computational research efforts on improving our understanding of the biochemical, molecular, and cellular processing of iododeoxyuridine (IUdR and ionizing radiation (IR induced DNA base damage by DNA mismatch repair (MMR. These coordinated research efforts, sponsored by the National Cancer Institute Integrative Cancer Biology Program (ICBP, brought together system scientists with expertise in engineering, mathematics, and complex systems theory and translational cancer researchers with expertise in radiation biology. Our overall goal was to begin to develop computational models of IUdR- and/or IR- induced base damage processing by MMR that may provide new clinical strategies to optimize IUdR-mediated radiosensitiztion in MMR deficient (MMR- damage tolerant human cancers. Using multiple scales of experimental testing, ranging from purified protein systems to in vitro (cellular and to in vivo (human tumor xenografts in athymic mice models, we have begun to integrate and interpolate these experimental data with hybrid stochastic biochemical models of MMR damage processing and probabilistic cell cycle regulation models through a systems biology approach. In this article, we highlight the results and current status of our integration of radiation biology approaches and computational modeling to enhance IUdR-mediated radiosensitization in MMR- damage tolerant cancers.

  8. DNA mismatch repair deficiency and hereditary syndromes in Latino patients with colorectal cancer.

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    Ricker, Charité N; Hanna, Diana L; Peng, Cheng; Nguyen, Nathalie T; Stern, Mariana C; Schmit, Stephanie L; Idos, Greg E; Patel, Ravi; Tsai, Steven; Ramirez, Veronica; Lin, Sonia; Shamasunadara, Vinay; Barzi, Afsaneh; Lenz, Heinz-Josef; Figueiredo, Jane C

    2017-10-01

    The landscape of hereditary syndromes and clinicopathologic characteristics among US Latino/Hispanic individuals with colorectal cancer (CRC) remains poorly understood. A total of 265 patients with CRC who were enrolled in the Hispanic Colorectal Cancer Study were included in the current study. Information regarding CRC risk factors was elicited through interviews, and treatment and survival data were abstracted from clinical charts. Tumor studies and germline genetic testing results were collected from medical records or performed using standard molecular methods. The mean age of the patients at the time of diagnosis was 53.7 years (standard deviation, 10.3 years), and 48.3% were female. Overall, 21.2% of patients reported a first-degree or second-degree relative with CRC; 3.4% met Amsterdam I/II criteria. With respect to Bethesda guidelines, 38.5% of patients met at least 1 criterion. Of the 161 individuals who had immunohistochemistry and/or microsatellite instability testing performed, 21 (13.0%) had mismatch repair (MMR)-deficient (dMMR) tumors. dMMR tumors were associated with female sex (61.9%), earlier age at the time of diagnosis (50.4 ± 12.4 years), proximal location (61.9%), and first-degree (23.8%) or second-degree (9.5%) family history of CRC. Among individuals with dMMR tumors, 13 (61.9%) had a germline MMR mutation (MutL homolog 1 [MLH1] in 6 patients; MutS homolog 2 [MSH2] in 4 patients; MutS homolog 6 [MHS6] in 2 patients; and PMS1 homolog 2, mismatch repair system component [PMS2] in 1 patient). The authors identified 2 additional MLH1 mutation carriers by genetic testing who had not received immunohistochemistry/microsatellite instability testing. In total, 5.7% of the entire cohort were confirmed to have Lynch syndrome. In addition, 6 individuals (2.3%) had a polyposis phenotype. The percentage of dMMR tumors noted among Latino individuals (13%) is similar to estimates in non-Hispanic white individuals. In the current study, the majority of

  9. Inter-individual variation in nucleotide excision repair pathway is modulated by non-synonymous polymorphisms in ERCC4 and MBD4 genes

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    Allione, Alessandra, E-mail: alessandra.allione@hugef-torino.org [Human Genetics Foundation (HuGeF), Via Nizza 52, 10126 Turin (Italy); Guarrera, Simonetta; Russo, Alessia [Human Genetics Foundation (HuGeF), Via Nizza 52, 10126 Turin (Italy); Ricceri, Fulvio [Human Genetics Foundation (HuGeF), Via Nizza 52, 10126 Turin (Italy); Department of Medical Sciences, University of Turin, Via Santena 19, 10126 Turin (Italy); Purohit, Rituraj [Human Genetics Foundation (HuGeF), Via Nizza 52, 10126 Turin (Italy); Bioinformatics Division, School of Bio Sciences and Technology, Vellore Institute of Technology University, Vellore 632014, Tamil Nadu (India); Pagnani, Andrea; Rosa, Fabio; Polidoro, Silvia; Voglino, Floriana [Human Genetics Foundation (HuGeF), Via Nizza 52, 10126 Turin (Italy); Matullo, Giuseppe [Human Genetics Foundation (HuGeF), Via Nizza 52, 10126 Turin (Italy); Department of Medical Sciences, University of Turin, Via Santena 19, 10126 Turin (Italy)

    2013-11-15

    Highlights: • We reported a large inter-individual variability of NER capacity. • ERCC4 rs1800124 and MBD4 rs10342 nsSNP variants were associated with DNA repair capacity. • DNA–protein interaction analyses showed alteration of binding for ERCC4 and MBD4 variants. • A new possible cross-talk between NER and BER pathways has been reported. - Abstract: Inter-individual differences in DNA repair capacity (DRC) may lead to genome instability and, consequently, modulate individual cancer risk. Among the different DNA repair pathways, nucleotide excision repair (NER) is one of the most versatile, as it can eliminate a wide range of helix-distorting DNA lesions caused by ultraviolet light irradiation and chemical mutagens. We performed a genotype–phenotype correlation study in 122 healthy subjects in order to assess if any associations exist between phenotypic profiles of NER and DNA repair gene single nucleotide polymorphisms (SNPs). Individuals were genotyped for 768 SNPs with a custom Illumina Golden Gate Assay, and peripheral blood mononuclear cells (PBMCs) of the same subjects were tested for a NER comet assay to measure DRC after challenging cells by benzo(a)pyrene diolepoxide (BPDE). We observed a large inter-individual variability of NER capacity, with women showing a statistically significant lower DRC (mean ± SD: 6.68 ± 4.76; p = 0.004) than men (mean ± SD: 8.89 ± 5.20). Moreover, DRC was significantly lower in individuals carrying a variant allele for the ERCC4 rs1800124 non-synonymous SNP (nsSNP) (p = 0.006) and significantly higher in subjects with the variant allele of MBD4 rs2005618 SNP (p = 0.008), in linkage disequilibrium (r{sup 2} = 0.908) with rs10342 nsSNP. Traditional in silico docking approaches on protein–DNA and protein–protein interaction showed that Gly875 variant in ERCC4 (rs1800124) decreases the DNA–protein interaction and that Ser273 and Thr273 variants in MBD4 (rs10342) indicate complete loss of protein

  10. Stepwise deletions of polyA sequences in mismatch repair-deficient colorectal cancers.

    Science.gov (United States)

    Blake, C; Tsao, J L; Wu, A; Shibata, D

    2001-05-01

    PolyA simple repeat sequence deletions are common in tumors with microsatellite instability (MSI+). Such deletions occur one base at a time in DNA mismatch repair (MMR)-deficient yeast suggesting larger deletions in human MSI+ tumors represent multiple sequential stepwise losses. Sum total deletions in four polyA repeats were variable (between -17 to -45 bp) in 20 sporadic MSI+ colorectal cancers. Progressive but less extensive total deletions (maximum of -12 bp) occurred in similar polyA sequences in MMR-deficient mice (mlh1-/-) up to 478 days old. PolyA repeat lengths were relatively stable but already shortened in the MMR-deficient cell line HCT116. A transgene with 26 A's transfected into HCT116 shortened an average of 3.8 bases pairs after 469 days in culture, less than average deletions of BAT25 (-5.3) or BAT26 (-9.0) in MSI+ cancers. These findings further suggest that extensive polyA deletions common in MSI+ tumors likely reflect multiple stepwise smaller deletions that accumulate more than hundreds of divisions after loss of MMR.

  11. Antibody persistence in children aged 6-7years one year following booster immunization with two MMR vaccines applied by aerosol or by injection.

    Science.gov (United States)

    Díaz Ortega, José Luis; Castaneda, Deyanira; Arellano Quintanilla, Doris Ma; Martínez, David; Trumbo, Silas P; Fernández de Castro, Jorge

    2017-05-25

    In a previous study on booster vaccination, we reported that two aerosolized MMR vaccines were as safe and immunogenic as injectable vaccines containing the same antigens. We now present results of antibody persistence one year after immunization. To assess the antibody persistence for measles, mumps, and rubella one year following booster immunization. We performed clinical and serological follow-up of participants in a previous study of Mexican children aged 6-7years, in which participants were randomized to four groups receiving, by aerosolized or by injection, the MMR SII vaccine (Serum Institute of India), or the MMR II (Merck Sharp & Dhome). We evaluated the antibody persistence by PRN test for measles and by ELISA for rubella and mumps. The occurrence of clinical events was evaluated via periodic visits of a nurse team to children's schools and homes. Of the 260 initial participants, 241 completed one-year follow-up. There were only statistically significant differences in baseline seropositivity for mumps. One year after immunization, seropositivity in all groups was 100% for measles and rubella. The seropositivity rank for mumps was from 90.3% for the injected vaccine MMR II to 96.6% for vaccine MMR SII applied by aerosol; these differences were not statistically significant. With exception of the aerosolized vaccine MMR SII for the geometric mean titer (GMT) for measles, all study groups presented declination of GMT for the three viruses. The difference between the aerosolized vaccines MMR SII and MMR RII was statistically significant for mumps antibodies. Only mild clinical events were identified. Under conditions of no endemic transmission for measles and rubella, and of low circulation of mumps virus, school-aged children remained seropositive to the three viruses one year following booster immunization. The study was registered under CMN 2010-005 number at COFEPRIS (National Regulatory Authority). Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Deletion of the nucleotide excision repair gene Ercc1 reduces immunoglobulin class switching and alters mutations near switch recombination junctions

    NARCIS (Netherlands)

    C.E. Schrader; J. Vardo; E. Linehan; M.Z. Twarog; L.J. Niedernhofer (Laura); J. Stavnezer; J.H.J. Hoeijmakers (Jan)

    2004-01-01

    textabstractThe structure-specific endonuclease ERCC1-XPF is an essential component of the nucleotide excision DNA repair pathway. ERCC1-XPF nicks double-stranded DNA immediately adjacent to 3' single-strand regions. Substrates include DNA bubbles and flaps. Furthermore, ERCC1 interacts with Msh2, a

  13. Explorative study to identify novel candidate genes related to oxaliplatin efficacy and toxicity using a DNA repair array.

    NARCIS (Netherlands)

    Kweekel, D.M.; Antonini, N.F.; Nortier, J.W.; Punt, C.J.A.; Gelderblom, H.; Guchelaar, H.J.

    2009-01-01

    PURPOSE: To identify new polymorphisms (single nucleotide polymorphisms, SNPs) in DNA repair pathways that are associated with efficacy and toxicity in patients receiving oxaliplatin and capecitabine for advanced colorectal cancer (ACC). METHODS: We studied progression-free survival (PFS) in 91 ACC

  14. Bladder exstrophy repair

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    Bladder birth defect repair; Everted bladder repair; Exposed bladder repair; Repair of bladder exstrophy ... Bladder exstrophy repair involves two surgeries. The first surgery is to repair the bladder and the second one is to attach ...

  15. Complex DNA repair pathways as possible therapeutic targets to overcome temozolomide resistance in glioblastoma

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    Koji eYoshimoto

    2012-12-01

    Full Text Available Many conventional chemotherapeutic drugs exert their cytotoxic function by inducing DNA damage in the tumor cell. Therefore, a cell-inherent DNA repair pathway, which reverses the DNA-damaging effect of the cytotoxic drugs, can mediate therapeutic resistance to chemotherapy. The monofunctional DNA-alkylating agent temozolomide (TMZ is a commonly used chemotherapeutic drug and the gold standard treatment for glioblastoma. Although the activity of DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT has been described as the main modulator to determine the sensitivity of glioblastoma to TMZ, a subset of glioblastoma does not respond despite MGMT inactivation, suggesting that another DNA repair mechanism may also modulate the tolerance to TMZ. Considerable interest has focused on MGMT, mismatch repair (MMR, and the base-excision repair (BER pathway in the mechanism of mediating TMZ resistance, but emerging roles for the DNA strand-break repair pathway have been demonstrated. In the first part of this review article, we briefly review the significant role of MGMT, MMR, and the BER pathway in the tolerance to TMZ; in the last part, we review the recent publications that demonstrate possible roles of DNA strand-break repair pathways, such as single-strand break (SSB repair and double-strand break (DSB repair, as well as the Fanconi anemia pathway in the repair process after alkylating agent-based therapy. It is possible that all of these repair pathways have a potential to modulate the sensitivity to TMZ and aid in overcoming the therapeutic resistance in the clinic.

  16. Missed Opportunities for Measles, Mumps, and Rubella (MMR Immunization in Mesoamerica: Potential Impact on Coverage and Days at Risk.

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    Ali H Mokdad

    Full Text Available Recent outbreaks of measles in the Americas have received news and popular attention, noting the importance of vaccination to population health. To estimate the potential increase in immunization coverage and reduction in days at risk if every opportunity to vaccinate a child was used, we analyzed vaccination histories of children 11-59 months of age from large household surveys in Mesoamerica.Our study included 22,234 children aged less than 59 months in El Salvador, Guatemala, Honduras, Mexico, Nicaragua, and Panama. Child vaccination cards were used to calculate coverage of measles, mumps, and rubella (MMR and to compute the number of days lived at risk. A child had a missed opportunity for vaccination if their card indicated a visit for vaccinations at which the child was not caught up to schedule for MMR. A Cox proportional hazards model was used to compute the hazard ratio associated with the reduction in days at risk, accounting for missed opportunities.El Salvador had the highest proportion of children with a vaccine card (91.2% while Nicaragua had the lowest (76.5%. Card MMR coverage ranged from 44.6% in Mexico to 79.6% in Honduras while potential coverage accounting for missed opportunities ranged from 70.8% in Nicaragua to 96.4% in El Salvador. Younger children were less likely to have a missed opportunity. In Panama, children from households with higher expenditure were more likely to have a missed opportunity for MMR vaccination compared to the poorest (OR 1.62, 95% CI: 1.06-2.47. In Nicaragua, compared to children of mothers with no education, children of mothers with primary education and secondary education were less likely to have a missed opportunity (OR 0.46, 95% CI: 0.24-0.88 and OR 0.25, 95% CI: 0.096-0.65, respectively. Mean days at risk for MMR ranged from 158 in Panama to 483 in Mexico while potential days at risk ranged from 92 in Panama to 239 in El Salvador.Our study found high levels of missed opportunities for

  17. Missed Opportunities for Measles, Mumps, and Rubella (MMR) Immunization in Mesoamerica: Potential Impact on Coverage and Days at Risk.

    Science.gov (United States)

    Mokdad, Ali H; Gagnier, Marielle C; Colson, K Ellicott; Dansereau, Emily; Zúñiga-Brenes, Paola; Ríos-Zertuche, Diego; Haakenstad, Annie; Johanns, Casey K; Palmisano, Erin B; Hernandez, Bernardo; Iriarte, Emma

    2015-01-01

    Recent outbreaks of measles in the Americas have received news and popular attention, noting the importance of vaccination to population health. To estimate the potential increase in immunization coverage and reduction in days at risk if every opportunity to vaccinate a child was used, we analyzed vaccination histories of children 11-59 months of age from large household surveys in Mesoamerica. Our study included 22,234 children aged less than 59 months in El Salvador, Guatemala, Honduras, Mexico, Nicaragua, and Panama. Child vaccination cards were used to calculate coverage of measles, mumps, and rubella (MMR) and to compute the number of days lived at risk. A child had a missed opportunity for vaccination if their card indicated a visit for vaccinations at which the child was not caught up to schedule for MMR. A Cox proportional hazards model was used to compute the hazard ratio associated with the reduction in days at risk, accounting for missed opportunities. El Salvador had the highest proportion of children with a vaccine card (91.2%) while Nicaragua had the lowest (76.5%). Card MMR coverage ranged from 44.6% in Mexico to 79.6% in Honduras while potential coverage accounting for missed opportunities ranged from 70.8% in Nicaragua to 96.4% in El Salvador. Younger children were less likely to have a missed opportunity. In Panama, children from households with higher expenditure were more likely to have a missed opportunity for MMR vaccination compared to the poorest (OR 1.62, 95% CI: 1.06-2.47). In Nicaragua, compared to children of mothers with no education, children of mothers with primary education and secondary education were less likely to have a missed opportunity (OR 0.46, 95% CI: 0.24-0.88 and OR 0.25, 95% CI: 0.096-0.65, respectively). Mean days at risk for MMR ranged from 158 in Panama to 483 in Mexico while potential days at risk ranged from 92 in Panama to 239 in El Salvador. Our study found high levels of missed opportunities for immunizing

  18. Kin-cohort estimates for familial breast cancer risk in relation to variants in DNA base excision repair, BRCA1 interacting and growth factor genes

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    Rutter Joni L

    2004-03-01

    Full Text Available Abstract Background Subtle functional deficiencies in highly conserved DNA repair or growth regulatory processes resulting from polymorphic variation may increase genetic susceptibility to breast cancer. Polymorphisms in DNA repair genes can impact protein function leading to genomic instability facilitated by growth stimulation and increased cancer risk. Thus, 19 single nucleotide polymorphisms (SNPs in eight genes involved in base excision repair (XRCC1, APEX, POLD1, BRCA1 protein interaction (BRIP1, ZNF350, BRCA2, and growth regulation (TGFß1, IGFBP3 were evaluated. Methods Genomic DNA samples were used in Taqman 5'-nuclease assays for most SNPs. Breast cancer risk to ages 50 and 70 were estimated using the kin-cohort method in which genotypes of relatives are inferred based on the known genotype of the index subject and Mendelian inheritance patterns. Family cancer history data was collected from a series of genotyped breast cancer cases (N = 748 identified within a cohort of female US radiologic technologists. Among 2,430 female first-degree relatives of cases, 190 breast cancers were reported. Results Genotypes associated with increased risk were: XRCC1 R194W (WW and RW vs. RR, cumulative risk up to age 70, risk ratio (RR = 2.3; 95% CI 1.3–3.8; XRCC1 R399Q (QQ vs. RR, cumulative risk up to age 70, RR = 1.9; 1.1–3.9; and BRIP1 (or BACH1 P919S (SS vs. PP, cumulative risk up to age 50, RR = 6.9; 1.6–29.3. The risk for those heterozygous for BRCA2 N372H and APEX D148E were significantly lower than risks for homozygotes of either allele, and these were the only two results that remained significant after adjusting for multiple comparisons. No associations with breast cancer were observed for: APEX Q51H; XRCC1 R280H; IGFPB3 -202A>C; TGFß1 L10P, P25R, and T263I; BRCA2 N289H and T1915M; BRIP1 -64A>C; and ZNF350 (or ZBRK1 1845C>T, L66P, R501S, and S472P. Conclusion Some variants in genes within the base-excision repair pathway (XRCC1 and

  19. Dose response and adaptive response of non-homologous end joining repair genes and proteins in resting human peripheral blood mononuclear cells exposed to γ radiation.

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    Shelke, Shridevi; Das, Birajalaxmi

    2015-05-01

    Ionising radiation induces single-strand breaks, double-strand breaks (DSB) and base damages in human cell. DSBs are the most deleterious and if not repaired may lead to genomic instability and cell death. DSB can be repaired through non-homologous end joining (NHEJ) pathway in resting lymphocytes. In this study, NHEJ genes and proteins were studied in irradiated human peripheral blood mononuclear cells (PBMC) at resting stage. Dose-response, time point kinetics and adaptive-response studies were conducted in irradiated PBMC at various end points such as DNA damage quantitation, transcription and protein expression profile. Venous blood samples were collected from 20 random, normal and healthy donors with written informed consent. PBMC was separated and irradiated with various doses between 0.1 and 2.0 Gy ((60)CO-γ source) for dose-response study. Repair kinetics of DNA damage and time point changes in expression of genes and proteins were studied in post-irradiated PBMC at 2.0 Gy at various time points up to 240 min. Adaptive-response study was conducted with a priming dose of 0.1 Gy followed by a challenging dose of 2.0 Gy after 4-h incubation. Our results revealed that Ku70, Ku80, XLF and Ligase IV were significantly upregulated (P Adaptive-response study showed significantly increased expression of the proteins involved in NHEJ, suggesting their role in adaptive response in human PBMC at G0/G1, which has important implications to human health. © The Author 2014. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Gene expression analysis during recovery process indicates the mechanism for innate immune injury and repair from Coxsackievirus B3-induced myocarditis.

    Science.gov (United States)

    Yao, Hai-Lan; Song, Juan; Sun, Peng; Song, Qin-Qin; Sheng, Lin-Jun; Chi, Miao-Miao; Han, Jun

    2016-02-02

    To investigate the innate immune injury and repair mechanism during recovery from Coxsackievirus B3 (CVB3) induced myocarditis, we established an acute viral myocarditis recovery model by infecting BALB/c mice with CVB3. Histopathological examination of cardiac tissues after infection showed a gradual increase of myocardial injury to the maximum degree at 8 dpi (days post infection), followed by a recovery process with reduced viral replication. We also measured expression changes of innate immune genes in heart after 4, 8 and 12 days of infection using innate immune real-time PCR array. The results showed expression alterations in many Pattern Recognition Receptors (PRRs) genes upon CVB3 infection, which activated multiple important signaling pathways during recovery process. The expression of TLRs, RLRs, PKR and cytokines were s