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  • 1
    Keywords: CANCER DIAGNOSIS ; THERAPIES ; DNA repair ; methods ; NEW-YORK ; GENE ; GENES ; PATIENT ; CANCER ; CELL ; carcinoma ; radiotherapy ; DIAGNOSIS ; THERAPY ; cell cycle ; CELL-CYCLE ; prognosis ; BREAST ; breast cancer ; BREAST-CANCER ; CANCER-PATIENTS ; side effects ; CANCER PATIENTS
    Type of Publication: Book chapter
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  • 2
    Keywords: treatment ; ASSOCIATION ; polymorphism ; POLYMORPHISMS ; single nucleotide polymorphism ; SUSCEPTIBILITY ; VARIANTS ; SKIN ; mechanisms ; prevention ; HEALTH ; PROMOTER ; BREAST ; breast cancer ; BREAST-CANCER ; cancer prevention ; smoking ; SNP ; REPAIR ; WOMEN ; LYMPHOCYTES ; DAMAGE ; GENOTYPES ; cancer risk ; CANCER-PATIENTS ; INDIVIDUALS ; case-control studies ; DNA-DAMAGE ; CANCER PATIENTS ; SUSCEPTIBILITY GENE ; BODY ; RISK ; GENE ; ENZYMES ; DISEASE ; lung cancer ; LUNG-CANCER ; PATIENT ; MECHANISM ; DNA ; TUMORS ; validation ; DRUG ; RNA ; GENES ; THERAPY ; VITRO ; LUNG ; COMBINATION ; CANCER ; EXPRESSION ; IN-VITRO ; CELLS ; CELL ; tumor ; AGENTS ; radiotherapy ; NSCLC ; CANCER-RISK ; cancer research ; RNA EXPRESSION ; ENZYME ; case control studies ; analysis ; GENOTYPE ; PROFILES ; single-nucleotide ; development ; PROMOTER POLYMORPHISM ; XRCC1 ; VARIANT ; WEIGHT ; SINGLE NUCLEOTIDE POLYMORPHISMS ; SNPs ; case-control study ; GEMCITABINE ; CAPACITY ; DEFICIENCY ; small cell lung cancer ; AGENT ; SINGLE ; DNA repair ; MPO ; APE1
    Abstract: Cells in the body are permanently attacked by DNA-reactive species, both from intracellular and environmental sources. Inherited and acquired deficiencies in host defense mechanisms against DNA damage (metabolic and DNA repair enzymes) can modify cancer susceptibility as well as therapy response. Genetic profiles should help to identify high-risk individuals who subsequently can be enrolled in preventive measures or treated by tailored therapy regimens. Some of our attempts to define such risk profiles are presented. Cancer susceptibility: Single nucleotide polymorphisms (SNPs) in metabolic and repair genes were investigated in a hospital-based lung cancer case-control study. When evaluating the risk associated with different genotypes for N-acetyltransferases (Wikman et al. 2001) and glutathione-S-transferases (Risch et al. 2001), it is mandatory to distinguish between the three major histological subtypes of lung tumors. A promoter polymorphism of the myeloperoxidase gene MPO was shown to decrease lung cancer susceptibility mainly in small cell lung cancer (SCLC) (Dally et al. 2002). The CYP3A4*1B allele was also linked to an increased SCLC risk and in smoking women increased the risk of lung cancer eightfold (Dally et al. 2003b). Polymorphisms in DNA repair genes were shown to modulate lung cancer risk in smokers, and reduced DNA repair capacity elevated the disease risk (Rajaee-Behbahani et al. 2001). Investigations of several DNA repair gene variants revealed that lung cancer risk was only moderately affected by a single variant but was enhanced up to approximately threefold by specific risk allele combinations (Popanda et al. 2004). Therapy response: Inter-individual differences in therapy response are consistently observed with cancer chemotherapeutic agents. Initial results from ongoing studies showed that certain polymorphisms in drug transporter genes (ABCB1) differentially affect response outcome in histological subgroups of lung cancer. Stronger beneficial effects were seen in non-small cell lung cancer (NSCLC) patients following gemcitabine and in SCLC patients following etoposide-based treatment. Several DNA repair parameters (polymorphisms, RNA expression, and DNA repair capacity) were measured in vitro in lymphocytes of patients before radiotherapy and correlated with the occurrence of acute side effects (radio-hypersensitivity). Our initial analysis of several repair gene variants in breast cancer patients (n = 446) who received radiotherapy revealed no association of single polymorphisms and the development of side effects (moist desquamation of the irradiated normal skin). The risk for this side effect was, however, strongly reduced in normal weight women carrying a combination of XRCC1 399Gln and APE1 148Glu alleles, indicating that these variants afford some protection against radio-hypersensitivity (Chang-Claude et al. 2005). Based on these data we conclude that specific metabolic and DNA repair gene variants can affect cancer risk and therapy outcome. Predisposition to hereditary cancer syndromes is dominated by the strong effects of some high-penetrance tumor susceptibility genes, while predisposition to sporadic cancer is influenced by the combination of multiple low-penetrance genes, of which as a major challenge, many disease-relevant combinations remain to be identified. Before translating these findings into clinical use and application for public health measures, large population-based studies and validation of the results will be required.
    Type of Publication: Book chapter
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    German Medical Science GMS Publishing House; Düsseldorf
    In:  Mainz//2011; 56. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie (gmds), 6. Jahrestagung der Deutschen Gesellschaft für Epidemiologie (DGEpi); 20110926-20110929; Mainz; DOC11gmds226 /20110920/
    Publication Date: 2011-09-20
    Keywords: genetic variants ; DNA repair ; lymphoma ; ddc: 610
    Language: English
    Type: conferenceObject
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  • 5
    Keywords: CANCER ; EXPRESSION ; carcinoma ; CELL ; Germany ; LUNG ; COMMON ; lung cancer ; LUNG-CANCER ; EXPOSURE ; RISK ; GENE ; GENES ; HYBRIDIZATION ; DNA ; MECHANISM ; primary ; RISK-FACTORS ; mechanisms ; ASSOCIATION ; polymorphism ; POLYMORPHISMS ; SUSCEPTIBILITY ; NO ; AMPLIFICATION ; AGE ; DNA-REPAIR ; REPAIR ; CIGARETTE-SMOKING ; risk factors ; smoking ; PCR ; cancer risk ; DAMAGE ; RISK FACTOR ; REGION ; CARCINOGENS ; adenocarcinoma ; case-control studies ; squamous cell carcinoma ; INDIVIDUALS ; CANCER-RESEARCH ; SMOKERS ; NUCLEOTIDE EXCISION-REPAIR ; CELL CARCINOMA ; case control study ; case-control study ; REGRESSION ; OCCUPATIONAL-EXPOSURE ; CARCINOGEN ; HEAVY ; LUNG ADENOCARCINOMA ; PIGMENTOSUM GROUP-A
    Abstract: Polymorphisms of genes coding for DNA repair can affect lung cancer risk. A common single nucleotide (-4) G-to-A polymorphism was identified previously in the 5' untranslated region of the XPA gene. In a case-control study in European Caucasians, the influence of this polymorphism on primary lung cancer risk overall and according to histologic subtypes was investigated. Four hundred sixty-three lung cancer cases (including 204 adenocarcinoma and 212 squamous cell carcinoma) and 460 tumor-free hospital controls were investigated using PCR amplification and melting point analysis of sequence-specific hybridization probes. Odds ratios (OR) were calculated by multiple logistic regression analysis adjusting for age, gender, smoking habits, and occupational exposure and showed a slightly enhanced risk for all lung cancer cases as well as for squamous cell carcinoma and adenocarcinoma cases. Gene-environment interactions were analyzed with respect to smoking and occupational exposure. A nearly 3-fold increased risk for adenocarcinoma associated with the XPA AA genotype was observed for occupationally exposed individuals (OR, 2.95; 95% confidence interval, 1.42-6.14) and for heavy smokers (OR, 2.52; 95% confidence interval, 1.17-5.42). No genotype-dependent increase in OR was found for nonexposed individuals or those smoking 〈20 pack-years. The significant effect of the XPA polymorphism in heavy smokers and occupationally exposed individuals suggests an important gene-environment interaction for the XPA gene. The underlying mechanisms as to why AA homozygotes are predisposed to lung adenocarcinoma and which specific carcinogens are involved remains to be determined
    Type of Publication: Journal article published
    PubMed ID: 15598786
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  • 6
    Keywords: CANCER ; IRRADIATION ; radiotherapy ; Germany ; TOXICITY ; LUNG-CANCER ; RISK ; RISKS ; GENE ; GENES ; HYBRIDIZATION ; SURGERY ; radiation ; PATIENT ; DNA ; GENETIC POLYMORPHISMS ; SKIN ; ASSOCIATION ; polymorphism ; POLYMORPHISMS ; SUSCEPTIBILITY ; VARIANTS ; BREAST ; breast cancer ; BREAST-CANCER ; DESIGN ; DNA-REPAIR ; REPAIR ; DAMAGE ; PROBES ; CARRIERS ; CANCER PATIENTS ; body mass index ; NUCLEOTIDE EXCISION-REPAIR ; DNA repair ; radiation sensitivity ; ACID SUBSTITUTION VARIANTS ; radiosensitivity ; MASSES ; RE ; VARIANT ; CAPACITY ; CANCER SUSCEPTIBILITY ; XPD ; ALLELES ; INTERVAL ; DNA repair gene ; DNA repair genes ; GENETIC-POLYMORPHISM ; CARRIER ; GENOTYPE ; HAPLOTYPE
    Abstract: Purpose: Several DNA repair gene polymorphisms have been described, which affect DNA repair capacity and modulate cancer susceptibility. We evaluated the association of six polymorphisms in the DNA repair genes: XRCC1 (Arg(194) Trp, Arg(280)His, and Arg(399)GIn), APE1 (Asp(148)Glu), and XPD (Lys(751)Gln and Asp(312)Asn), with the risk of acute skin reactions following radiotherapy. Design: We conducted a prospective study of 446 female patients with breast cancer who received radiotherapy after breast-conserving surgery. Individual genetic polymorphisms were determined using melting point analysis of sequence-specific hybridization probes. The development of acute skin reactions (moist desquamation) associated with DNA repair gene polymorphisms was modeled using Cox proportional hazards, accounting for cumulative biologically effective radiation dose. Results: Overall, the development of acute toxicity, which presented in 77 patients, was not associated with the genetic variants studied, although the hazard ratios (HR) were generally below 1. Risks were however differential by body mass index. Among normal-weight patients only, both carriers of theAPE1 (148)Glu and the XRCC1 (399)Gln alleles had decreased risk of acute skin reactions after radiotherapy (HR, 0.49 and 0.51, respectively). The results for XRCC1 were confirmed by haplotype analysis. When considering joint effects, we observed that compared with homozygote carriers of the wild-type allele in both genes, the risk was most strongly reduced in carriers of both APE1 (148)Glu and XRCC1 (399)GIn alleles with normal weight [HR, 0.19; 95% confidence interval (95% CI), 0.06-0.56] but not in those with overweight (HR, 1.39; 95% CI, 0.56-3.45; P-interaction = 0-009). Conclusion: The XRCC1 (399)Gln or APE1 (148)Glu alleles may be protective against the development of acute side effects after radiotherapy in patients with normal weight
    Type of Publication: Journal article published
    PubMed ID: 16000577
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  • 7
    Keywords: CANCER ; IONIZING-RADIATION ; LUNG-CANCER ; EXPOSURE ; HISTORY ; POPULATION ; RISK ; GENE ; GENES ; radiation ; DNA ; FAMILY ; INDEX ; BIOMARKERS ; ASSOCIATION ; FREQUENCY ; polymorphism ; POLYMORPHISMS ; SUSCEPTIBILITY ; FREQUENCIES ; BREAST ; breast cancer ; BREAST-CANCER ; AGE ; family history ; WOMEN ; DNA-REPAIR ; REPAIR ; smoking ; COLORECTAL-CANCER ; BLADDER-CANCER ; cancer risk ; INSTABILITY ; PARAMETERS ; TRANSFORMATION ; genetic polymorphism ; case-control studies ; TOBACCO ; ALCOHOL ; BODY ; FLUORESCENCE ; DNA repair ; SKIN-CANCER ; POSTMENOPAUSAL WOMEN ; MASS INDEX ; MASSES ; BODIES ; case control study ; case-control study ; RE ; FAMILIES ; CAPACITY ; ALLELE ; SINGLE NUCLEOTIDE POLYMORPHISMS ; XPD ; individual susceptibility ; biomarker ; case control studies ; INTERVAL ; analysis ; PREMENOPAUSAL WOMEN ; FAMILY-HISTORY ; PREMENOPAUSAL ; odds ratio ; CANCER-RISK ; TOXICOLOGY ; microbiology ; CHINESE POPULATION ; - ; BODY-MASS ; BODY-MASS-INDEX ; biotechnology ; XRCC3 ; REPAIR GENE XRCC3
    Abstract: The X- ray repair cross- complementing group 3 gene ( XRCC3) belongs to a family of genes responsible for repairing DNA double- strand breaks caused by normal metabolic processes and exposure to ionizing radiation. Polymorphisms in DNA repair genes may alter an individual's capacity to repair damaged DNA and may lead to genetic instability and contribute to malignant transformation. We examined the role of a polymorphism in the XRCC3 gene ( rs861529; codon 241: threonine to methionine change) in determining breast cancer risk in Thai women. The study population consisted of 507 breast cancer cases and 425 healthy women. The polymorphism was analysed by fluorescence- based melting curve analysis. The XRCC3 241Met allele was found to be uncommon in the Thai population ( frequency 0.07 among cases and 0.05 among controls). Odds ratios ( OR) adjusted for age, body mass index, age at menarche, family history of breast cancer, menopausal status, reproduction parameters, use of contraceptives, tobacco smoking, involuntary tobacco smoking, alcohol drinking, and education were calculated for the entire population as well as for pre- and postmenopausal women. There was a significant association between 241Met carrier status and breast cancer risk ( OR 1.58, 95% confidence interval ( CI) 1.02 - 2.44). Among postmenopausal women, a slightly higher OR ( 1.82, 95% CI 0.95 - 3.51) was found than among premenopausal women ( OR 1.48, 95% CI 0.82 - 2.69). Our findings suggest that the XRCC3 Thr241Met polymorphism is likely to play a modifying role in the individual susceptibility to breast cancer among Thai women as already shown for women of European ancestry
    Type of Publication: Journal article published
    PubMed ID: 17701750
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  • 8
    Keywords: CANCER ; CELL ; LUNG ; PATHWAY ; PATHWAYS ; lung cancer ; LUNG-CANCER ; EPIDEMIOLOGY ; RISK ; GENE ; GENES ; validation ; DNA ; BIOMARKERS ; cell cycle ; CELL-CYCLE ; SEQUENCE ; ASSOCIATION ; SUSCEPTIBILITY ; SUSCEPTIBILITY LOCUS ; VARIANTS ; HEALTH ; NUMBER ; REPAIR ; smoking ; p53 ; cancer risk ; FRANCE ; genotyping ; DNA repair ; TP53 ; ONCOLOGY ; VARIANT ; METAANALYSIS ; XRCC1 ; SINGLE-NUCLEOTIDE POLYMORPHISMS ; biomarker ; analysis ; methods ; DNA repair genes ; pooled analysis ; USA ; cancer research ; CANCER-RISK ; OGG1 ; NOV ; GENOME-WIDE ASSOCIATION ; association study ; XRCC3 ; discussion ; POOLED-ANALYSIS ; CONSORTIUM ; genetic variants ; GENOME-WIDE ; APEX1
    Abstract: Background: The International Lung Cancer Consortium was established in 2004. To clarify the role of DNA repair genes in lung cancer susceptibility, we conducted a pooled analysis of genetic variants in DNA repair pathways, whose associations have been investigated by at least 3 individual studies. Methods: Data from 14 studies were pooled for 18 sequence variants in 12 DNA repair genes, including APEX1, OGG1, XRCC1, XRCC2, XRCC3, ERCC1, XPD, XPF, XPG, XPA, MGMT, and TP53. The total number of subjects included in the analysis for each variant ranged from 2,073 to 13,955 subjects. Results: Four of the variants were found to be weakly associated with lung cancer risk with borderline significance: these were XRCC3 T241M [heterozygote odds ratio (OR), 0.89; 95% confidence interval (95% CI), 0.79-0.99 and homozygote OR, 0.84; 95% Cl, 0.71-1.00] based on 3,467 cases and 5,021 controls from 8 studies, XPD K751Q (heterozygote OR, 0.99; 95% Cl, 0.89-1.10 and homozygote OR, 1.19; 95% CI, 1.02-1.39) based on 6,463 cases and 6,603 controls from 9 studies, and TP53 R72P (heterozygote OR, 1.14; 95% Cl, 1.00-1.29 and homozygote OR, 1.20; 95% CI, 1.02-1.42) based on 3,610 cases and 5,293 controls from 6 studies. OGG1 S326C homozygote was suggested to be associated with lung cancer risk in Caucasians (homozygote OR, 1.34; 95% CI, 1.01-1.79) based on 2,569 cases and 4,178 controls from 4 studies but not in Asians. The other 14 variants did not exhibit main effects on lung cancer risk. Discussion: In addition to data pooling, future priorities of International Lung Cancer Consortium include coordinated genotyping and multistage validation for ongoing genome-wide association studies. (Cancer Epidemiol Biomarkers Prev 2008;17(11):3081-9)
    Type of Publication: Journal article published
    PubMed ID: 18990748
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  • 9
    Keywords: CANCER ; CELLS ; EXPRESSION ; TUMORS ; COMPLEX ; prognosis ; RETINOIC ACID RECEPTORS
    Abstract: Impairment of endogenous differentiation pathways like retinoic acid (RA) signaling seems to be a central pathogenetic event in astrocytic gliomas. Among others, expression of the differentiation-promoting RA chaperon protein cellular retinoic acid binding protein 2 (CRABP2) is extenuated in high-grade gliomas. Against this background, we aimed at identifying potential pathomechanisms underlying reduced CRABP2 expression in these tumors. Employing MassARRAY methylation analysis we detected extensive CpG methylation upstream of the CRABP2 gene locus in a study sample comprising 100 astrocytic gliomas of WHO grade II to IV. Compared to non-tumorous control samples tumors revealed increased CpG methylation and methylation levels were inversely correlated to CRABP2 mRNA expression. Substantiating our in situ findings, CRABP2 mRNA levels increased in glioma cell lines after exposure to the demethylating agent 5-aza-2'-deoxycytidine. Finally, a distinct CpG methylation signature distinguished between primary glioblastoma on the one hand and the group of astrocytoma WHO II-III and secondary glioblastoma on the other hand. Altogether, our observations suggest that epigenetic silencing of CRABP2 might contribute to an immature phenotype in glioma cells.
    Type of Publication: Journal article published
    PubMed ID: 22275178
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  • 10
    Keywords: CANCER ; TUMOR-CELLS ; RISK ; GENE ; CELL-CYCLE ; CYCLE ; MAMMALIAN-CELLS ; XERODERMA-PIGMENTOSUM ; traditional Chinese medicine ; cancer therapy ; TRADITIONAL CHINESE-MEDICINE ; essential oil ; COCKAYNE-SYNDROME ; CSB ; INDUCED DNA-DAMAGE ; PIGMENTOSUM GROUP-C ; XPC ; CHENOPODIUM ; ERCC6 ; Synthetic lethal
    Abstract: Targeting synthetic lethality in DNA repair pathways has become a promising anti-cancer strategy. However little is known about such interactions with regard to the nucleotide excision repair (NER) pathway. Therefore, cell lines with a defect in the NER genes ERCC6 or XPC and their normal counterparts were screened with 53 chemically defined phytochemicals isolated from plants used in traditional Chinese medicine for differential cytotoxic effects. The screening revealed 12 drugs that killed NER-deficient cells more efficiently than proficient cells. Five drugs were further analyzed for IC(50) values, effects on cell cycle distribution, and induction of DNA damage. Ascaridol was the most effective compound with a difference of 〉1000-fold in resistance between normal and NER-deficient cells (IC(50) values for cells with deficiency in ERCC6: 0.15muM, XPC: 0.18muM, and normal cells: 〉180muM). NER-deficiency combined with ascaridol treatment led to G2/M-phase arrest, an increased percentage of subG1 cells, and a substantially higher DNA damage induction. These results were confirmed in a second set of NER-deficient and -proficient cell lines with isogenic background. Finally, ascaridol was characterized for its ability to generate oxidative DNA damage. The drug led to a dose-dependent increase in intracellular levels of reactive oxygen species at cytotoxic concentrations, but only NER-deficient cells showed a strongly induced amount of 8-oxodG sites. In summary, ascaridol is a cytotoxic and DNA-damaging compound which generates intracellular reactive oxidative intermediates and which selectively affects NER-deficient cells. This could provide a new therapeutic option to treat cancer cells with mutations in NER genes.
    Type of Publication: Journal article published
    PubMed ID: 22280988
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