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Bjørn A Nexø

Publications and source records attributed to Bjørn A Nexø.

18 recordsLinked to original sources
PubMed2007

Polymorphisms in the genes ERCC2, XRCC3 and CD3EAP influence treatment outcome in multiple myeloma patients undergoing autologous bone marrow transplantation.

Individual variations in the ability to cope with DNA damage by DNA repair may be essential for the response to chemotherapy, since cancer cells from patients with an effective DNA repair may survive treatment. We have studied the effect on time to treatment failure (TTF) and overall survival (OS) of polymorphism in the DNA repair genes ERCC1, ERCC2 and XRCC3, and in the apoptotic genes PPP1R13L and CD3EAP in 348 patients with multiple myeloma undergoing autologous bone marrow transplantation. Carriers of the variant C-allele of ERCC2 K751Q, the variant T-allele of XRCC3 T241M and the variant A-allele of CD3EAP G-21A had a 1.3-fold, 1.8-fold and 1.9-fold longer TTF, respectively, than homozygous wild type carriers (p = 0.006, p = 0.004, p < 0.001). The polymorphism CD3EAP G-21A also had significant effect on OS (p < 0.045). The polymorphism ERCC2 K751Q may to be related to sex, since the prolonged TTF was only seen in women (p = 0.001). Carriers of the combination of variant alleles of ERCC2 K751Q and XRCC3 T241M had 2.8-fold longer TTF (p = 0.0002). This indicates that suboptimal repair of both DNA mechanisms favors prolonged TTF and that polymorphism in ERCC2, XRCC3 and CD3EAP predicts the outcome for patients treated with autologous stem cell transplantation.

Aged↗
PubMed2006

Peroxisome proliferator-activated [corrected] receptor-gamma2 [corrected] Pro12Ala, interaction with alcohol intake and NSAID use, in relation to risk of breast cancer in a prospective study of Danes.

Use of non-steroid anti-inflammatory drugs (NSAIDs) has been associated with decreased risk of breast cancer in epidemiological studies. Thus, a high-inflammatory response may be associated with increased breast cancer risk. It is thus possible that genetic variations leading to a modified inflammatory response will influence breast cancer risk. The purpose of this study was to determine if polymorphisms associated with an altered inflammatory response are associated with breast cancer risk, and to investigate the possible interaction with lifestyle factors such as alcohol use, smoking and NSAID use. We matched 361 female breast cancer cases with 361 controls, nested within the prospective 'Diet, Cancer and Health' study. Carriers of the variant Ala-allele of PPARgamma2 Pro12Ala were at lower risk of breast cancer (IRR=0.67, 95% CI=0.46-0.97). This was primarily due to an interaction with alcohol consumption. Alcohol consumption was associated with a 1.21-fold increased risk of breast cancer per 10 g alcohol/day (95% CI=1.06-1.35) among homozygous wild-type carriers, whereas alcohol was not associated with breast cancer risk among variant allele carriers (P for interaction=0.005). Non-users of NSAID, who were carriers of the variant allele of PPARgamma2 Pro12Ala, were at lower risk of breast cancer (IRR=0.44; 95% CI=0.26-0.73) compared with non-users carrying wild-type alleles (P for interaction=0.03). No effects were found for IL6 G-174C, IL8 T-251A and COX2 T8473C. Our results suggest that PPARgamma2 Pro12Ala is an important determinant in alcohol mediated breast carcinogenesis. We also observe interaction between NSAID, alcohol consumption and PPARgamma2 Pro12Ala genotype in relation to breast cancer risk.

Alanine↗
PubMed2006

Effects of polymorphisms in ERCC1, ASE-1 and RAI on the risk of colorectal carcinomas and adenomas: a case control study.

BACKGROUND: The risk of sporadic colorectal cancer is mainly associated with lifestyle factors and may be modulated by several genetic factors of low penetrance. Genetic variants represented by single nucleotide polymorphisms in genes encoding key players in the adenoma carcinoma sequence may contribute to variation in susceptibility to colorectal cancer. In this study, we aimed to evaluate whether the recently identified haplotype encompassing genes of DNA repair and apoptosis, is associated with increased risk of colorectal adenomas and carcinomas. METHODS: We used a case-control study design (156 carcinomas, 981 adenomas and 399 controls) to test the association between polymorphisms in the chromosomal region 19q13.2-3, encompassing the genes ERCC1, ASE-1 and RAI, and risk of colorectal adenomas and carcinomas in a Norwegian cohort. Odds ratio (OR) and 95% confidence interval (CI) were estimated by binary logistic regression model adjusting for age and gender. RESULTS: The ASE-1 polymorphism was associated with an increased risk of adenomas, OR of 1.39 (95% CI 1.06-1.81), which upon stratification was apparent among women only, OR of 1.66 (95% CI 1.15-2.39). The RAI polymorphism showed a trend towards risk reduction for both adenomas (OR of 0.70, 95% CI 0.49-1.01) and carcinomas (OR of 0.49, 95% CI 0.21-1.13) among women, although not significant. Women who were homozygous carriers of the high risk haplotype had an increased risk of colorectal cancer, OR of 2.19 (95% CI 0.95-5.04) compared to all non-carriers although the estimate was not statistically significant. CONCLUSION: We found no evidence that the studied polymorphisms were associated with risk of adenomas or colorectal cancer among men, but we found weak indications that the chromosomal region may influence risk of colorectal cancer and adenoma development in women.

Adenoma↗
PubMed2006

Gene-environment interactions between smoking and a haplotype of RAI, ASE-1 and ERCC1 polymorphisms among women in relation to risk of lung cancer in a population-based study.

Homozygous carriers of a haplotype consisting of ERCC1 Asn118Asn(A), ASE-1 G-21A(G), RAI IVS1 A4364G(A) are at increased risk of lung cancer especially among women. Here, we analyse for gene-environment interactions with the predefined haplotype in a case cohort study including 428 lung cancer cases and a comparison group of 800 persons, all from the prospective Diet, Cancer and Health cohort of 57,000 Danes. At high smoking intensity (>20g tobacco/day), there was only additional risk of smoking intensity among women who were homozygous carriers of the haplotype (IRR=2.03; 95% CI: 1.10-3.73 per 5 additional g tobacco/day).

Adult↗
PubMed2005

Associations between GPX1 Pro198Leu polymorphism, erythrocyte GPX activity, alcohol consumption and breast cancer risk in a prospective cohort study.

Breast cancer may be related to oxidative stress. Breast cancer patients have been reported to have lower antioxidant enzyme activity than healthy controls and the polymorphism GPX1 Pro198Leu has been associated with risk of lung and breast cancer. The purpose of the present nested case-control study was to determine whether GPX1 Pro198Leu and glutathione peroxidase (GPX) activity in prospectively collected blood samples are associated with breast cancer risk among postmenopausal women and whether GPX activity levels are associated with other known breast cancer risk factors. We matched 377 female breast cancer cases with 377 controls all nested within the prospective 'Diet, Cancer and Health' study of 57 000 Danes. Carriers of the variant T-allele of GPX1 Pro198Leu were at 1.43-fold higher risk of breast cancer compared with non-carriers (95% CI=1.07-1.92). Pre-diagnostic GPX activity tended to be lower in cases compared with controls. GPX activity was positively correlated with intake of alcohol (P<0.0001) and the catalytic activity was lowered 5% for each additional copy of the variant T-allele (P=0.0003). Alcohol intake was correlated with increased GPX activity for the C-allele but not for the T-allele. Results from this prospective study suggest that the GPX1 Pro198Leu-associated lowered GPX activity is associated with higher breast cancer risk among Danish women.

Alcohol Drinking↗
PubMed2005

Polymorphisms in RAI and in genes of nucleotide and base excision repair are not associated with risk of testicular cancer.

Testicular cancer has been suggested to be primed in utero and there is familiar occurrence, particularly brothers and sons of men with testicular cancer have increased risk. Although no specific causative genotoxic agents have been identified, variations in DNA repair capacity could be associated with the risk of testicular cancer. A case-control study of 184 testicular cancer cases and 194 population-based controls living in the Copenhagen Greater Area in Denmark was performed. We found that neither polymorphisms in several DNA repair genes nor alleles of several polymorphisms in the chromosomal of region 19q13.2-3, encompassing the genes ASE, ERCC1, RAI and XPD, were associated with risk of testicular cancer in Danish patients. This is in contrast to other cancers, where we reported strong associations between polymorphisms in ERCC1, ASE and RAI and occurrence of basal cell carcinoma, breast cancer and lung. To our knowledge this is the first study of DNA repair gene polymorphisms and risk of testicular cancer.

Case-Control Studies↗
PubMed2005

ERCC1, XPD and RAI mRNA levels in lymphocytes are not associated with lung cancer risk in a prospective study of Danes.

Low DNA-repair capacity has been associated with increased risk of several types of cancer. mRNA levels of the nucleotide excision repair genes ERCC1 and XPD have been shown to correlate with the DNA-repair capacity. Likewise, mRNA levels of several DNA-repair genes including ERCC1 have been shown to be lower in lymphocytes from patients with lung cancer and head and neck cancer compared with healthy persons. In these studies, the low DNA-repair gene expression levels could be either a risk factor for disease or a consequence of the same. In this nested case-cohort study, which to our knowledge, is the first prospective study of DNA-repair gene mRNA levels as predictors of lung cancer, we have investigated the occurrence of lung cancer in relation to the mRNA level of the two DNA-repair genes ERCC1 and XPD and the NF kappaB inhibitor RAI in blood samples prior to disease. Among 54,220 members of a Danish prospective cohort study, 265 lung cancer cases were identified and a sub-cohort comprising 272 individuals was used for comparison. The expression levels of the three adjacent genes were found to be highly inter-correlated, to be higher in women compared to men and to be lower in older individuals. The incidence rate ratios for lung cancer in association with one log-unit increase (natural logarithm) in mRNA levels were 1.12 (CI=0.89-1.41) for ERCC1, 1.00 (CI=0.83-1.21) for XPD and 1.25 (0.89-1.74) for RAI. In conclusion, this study indicated no association between mRNA expression of the DNA-repair genes ERCC1 and XPD and risk of subsequent development of lung cancer.

DNA-Binding Proteins↗
PubMed2005

Combinations of polymorphisms in XPD, XPC and XPA in relation to risk of lung cancer.

Inherited polymorphisms in DNA repair genes may contribute to genetic susceptibility to cancer. XPA, XPC and XPD all encode proteins that are part of the nucleotide excision repair pathway. In a nested case-cohort study, we have investigated the occurrence of lung cancer in relation to commonly occurring polymorphisms in XPA, XPC and XPD. Among 54,220 members of a Danish prospective cohort study, 265 lung cancer cases were identified and a sub-cohort comprising 272 individuals was used for comparison. We found that XPA A23G and XPC Lys939Gln polymorphisms may be risk factors for lung cancer and evidence that positive interactions between the polymorphisms in XPA/XPD and XPC/XPD may occur.

DNA Helicases↗
PubMed2005

Effect of polymorphisms in XPD, RAI, ASE-1 and ERCC1 on the risk of basal cell carcinoma among Caucasians after age 50.

We have investigated the occurrence of basal cell carcinoma (BCC) in relation to a number of single nucleotide polymorphisms (SNPs) in the chromosomal region 19q13.2-3. A case-control study including 322 basal cell carcinoma cases and a similar number of controls was nested in a population-based prospective investigation encompassing 57,053 Danes (aged 50-64 at inclusion) living in Copenhagen or Aarhus in Denmark. We found that the polymorphism XPD Arg156Arg was associated with risk of basal cell carcinoma (rate ratio (RR)=1.59, 95% confidence interval (CI)=1.02-2.50 for homozygous carriers of the A-allele), and that the association was strongest in the youngest age interval of the study group (50-55 years) (RR=2.33, 95% CI=1.03-5.28). The polymorphisms XPD Asp312Asn and XPD Lys751Gln were not associated with risk of basal cell carcinoma. While it cannot be ruled out that the present findings are due to chance, the present results are consistent with previous findings that XPD Arg156Arg is a weak risk factor for basal cell carcinoma.

Age of Onset↗
PubMed2005

SNP genotyping using microsphere-linked PNA and flow cytometric detection.

BACKGROUND: Single nucleotide polymorphisms (SNPs) represent the most frequent form of genetic variations. Some of the most sensitive methods for SNP genotyping employ synthetic oligonucleotides, such as the peptide nucleic acid (PNA). We introduce a new method combining allele-specific hybridization, PNA technology, and flow cytometric detection. We tested the design by genotyping a Danish basal cell carcinoma cohort of 80 individuals for an A/C SNP in exon 6 of the XPD gene. METHODS: Genomic DNA was amplified by a two-step polymerase chain reaction (PCR) in the presence of fluorescein-dyed primers and fluorescein-12-dUTP. The allele-specific PNA molecules were covalently coupled to carboxylated microspheres with and without rhodamine. Allele-specific hybridization between PCR products and immobilized PNA was carried out at 60 degrees C followed by flow cytometric detection. RESULTS: We present a fully functional two-bead genotyping system based on PNA capture and flow cytometric detection used for the correct and fast regenotyping of a Danish basal cell carcinoma cohort. CONCLUSIONS: This new assay presents a simple, rapid, and robust method for SNP genotyping for laboratories equipped with a standard flow cytometer. Moreover, this system offers potential for multiplexing and will be operational for middle-scale genotyping.

Basal Cell Carcinoma↗
PubMed2004

Two regions in chromosome 19q13.2-3 are associated with risk of lung cancer.

Lung cancer is the most common fatal cancer among Danish men, and the incidence rate is increasing among women. In a case-cohort study, we have investigated the occurrence of lung cancer in relation to a high-risk haplotype, previously identified for breast cancer among post-menopausal women, and in relation to the closely linked polymorphisms XPD Asp312Asn and Lys751Gln. Among 54220 members of a Danish prospective cohort study aged 50-64 at entry, 265 lung cancer cases were identified and a sub-cohort comprising 272 individuals was used for comparison. Among women in the 50-55 year age interval, homozygous carriers of the high-risk haplotype were at increased risk of lung cancer (RR=7.02, 95% CI=1.88-26.18). In the 56-60 year and 61-70 year age intervals, no associations were observed. Among men, no statistically significant associations were found in any age interval. Female homozygous carriers of the variant allele of XPD Lys751Gln were at significantly increased risk of lung cancer in the two younger age-intervals (50-55 years: RR=5.60, 95% CI=1.18-26.45, 56-60 years: RR=10.60, 95% CI=1.50-75.64). Among men, carriers of the variant allele of XPD Lys751Gln had a non-significantly increased risk of lung cancer in the youngest age interval (RR=6.38, 95% CI=0.74-54.90). When the polymorphisms in XPD Asp312Asn and Lys751Gln were mutually adjusted, XPD Asp312Asn was not associated with increased risk of cancer. We found no interaction between genotypes and duration of smoking. In conclusion, two regions of chromosome 19q13.2-3 seem to be associated with risk of lung cancer.

Aged↗
PubMed2004

A polymorphic marker in the first intron of the Werner gene associates with cognitive function in aged Danish twins.

Werner's syndrome is a premature aging syndrome with many features common to normal aging. The possible association between phenotypic markers for normal aging and SNP's in the WRN gene was investigated in 426 dizygotic, Danish twins age 70-90 years. All participants were scored every second year using a number of physical and cognitive tests. In addition their self-rated health was registered as well as self reported status with regards to nine diseases. Blood was drawn from all participants and purified DNA was typed for four SNP's in the WRN gene. The four SNP's were located in intron 1, exon 6, exon 9 and exon 34. In an unpaired analysis of this material a significant association between the intron 1 SNP and cognitive function was demonstrated. Our finding, which will need corroboration in independent samples, therefore may suggest that the t-allele of the intron 1 SNP is beneficial to cognitive function. However, since the t-allele of this SNP is very rare, we did not encounter any tt-homozygous individuals for this allele.

Activities of Daily Living↗
PubMed2004

No association between base excision repair gene polymorphisms and risk of lung cancer.

In a nested case-cohort study, we have investigated the occurrence of lung cancer in relation to polymorphisms in base excision repair genes XRCC1 and OGG1. Among 54,220 members of a Danish prospective cohort study, aged 50-65 years at entry, 265 lung cancer cases were identified and a subcohort comprising 272 individuals was used for comparison. No associations were found between the polymorphisms OGG1 Ser326Cys, XRCC1 Arg280His, and XRCCI Arg399Gln and risk of lung cancer. This is the first study of polymorphisms in base excision repair genes in relation to lung cancer among Danes.

Aged↗
PubMed2003

A specific haplotype of single nucleotide polymorphisms on chromosome 19q13.2-3 encompassing the gene RAI is indicative of post-menopausal breast cancer before age 55.

The new genetic information, in particular the greatly increased density of markers in the chromosomal maps, may permit analysis of the importance of genes in the development of disease exclusively from molecular epidemiological studies. Motivated by our previous results on the same region in relation to basal cell carcinoma we have investigated the occurrence of post-menopausal breast cancer in relation to a number of single nucleotide polymorphisms in the chromosomal region 19q13.2-3. A case-control study including 425 human cases and a similar number of controls was nested in a population-based prospective investigation encompassing 24 697 Danish post-menopausal women (aged 50-64 at inclusion) living in Copenhagen or Aarhus. We combined three markers located together in or near the gene RAI into a high-risk haplotype. Compared with all other haplotypes, those who were homozygous had a rate ratio of 1.64 (95% CI 1.17-2.29, P < or = 0.004) for development of breast cancer. When we further focused on those persons with post-menopausal breast cancer before age 55 the rate ratio increased to 9.5 (95% CI 2.21-40.79, P < or = 0.003). The likely explanation for our results is a common recessive genetic variant located in or near the gene RAI, which, when homozygous, conveys an increased risk of breast cancer. Presumably it is identical to the genetic variant previously observed in the same region that increases the risk of basal cell carcinoma before age 50.

Alleles↗
PubMed2002

Association of chromosome 19q13.2-3 haplotypes with basal cell carcinoma: tentative delineation of an involved region using data for single nucleotide polymorphisms in two cohorts.

We have previously used single nucleotide polymorphisms to detect an association of basal cell carcinoma (BCC) in Caucasian Americans and Danes with the genome region 19q13.2-3, which contains several genes involved in the nucleotide excision repair of DNA. In this exploratory paper we have extended the data and used them in a chromosomal scan. The results indicate the presence of a gene variation modulating the risk of developing BSS in a submegabase region including and surrounding the gene RAI. Specifically, persons that are homozygous for the haplotype RAI intron 1(A) RAI exon 6(A) appear at increased risk for BCC. In addition, we have looked for possible synergisms between all pairs of markers. We find that a marker in GLTSCR1, presumably separated from RAI by several million bases, supplements the most significant marker in RAI in separating cases from controls, which may suggest the presence of an independent, risk-modulating variation in this second gene region.

Adult↗