| 61. |
- Berntsson, Shala Ghaderi, et al.
(författare)
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Analysis of DNA repair gene polymorphisms and survival in low-grade and anaplastic gliomas
- 2011
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Ingår i: Journal of Neuro-Oncology. - : Springer Science and Business Media LLC. - 0167-594X .- 1573-7373. ; 105:3, s. 531-538
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Tidskriftsartikel (refereegranskat)abstract
- 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 II and grade III gliomas samples, collected in Sweden and Denmark. The statistically significant genetic variants from the first dataset (P < 0.05) were taken forward for confirmation in a second dataset of 72 grade II and III gliomas from northern UK. In this dataset, eight gene variants mapping to five different DNA repair genes (ATM, NEIL1, NEIL2, ERCC6 and RPA4) which were associated with survival. Finally, these eight genetic variants were adjusted for treatment, malignancy grade, patient age and gender, leaving one variant, rs4253079, mapped to ERCC6, with a significant association to survival (OR 0.184, 95% CI 0.054-0.63, P = 0.007). We suggest a possible novel association between rs4253079 and survival in this group of patients with low-grade and anaplastic gliomas that needs confirmation in larger datasets.
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| 62. |
- Bhattacharjee, Samsiddhi, et al.
(författare)
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A subset-based approach improves power and interpretation for the combined analysis of genetic association studies of heterogeneous traits
- 2012
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Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297 .- 1537-6605. ; 90:5, s. 821-835
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Tidskriftsartikel (refereegranskat)abstract
- Pooling genome-wide association studies (GWASs) increases power but also poses methodological challenges because studies are often heterogeneous. For example, combining GWASs of related but distinct traits can provide promising directions for the discovery of loci with small but common pleiotropic effects. Classical approaches for meta-analysis or pooled analysis, however, might not be suitable for such analysis because individual variants are likely to be associated with only a subset of the traits or might demonstrate effects in different directions. We propose a method that exhaustively explores subsets of studies for the presence of true association signals that are in either the same direction or possibly opposite directions. An efficient approximation is used for rapid evaluation of p values. We present two illustrative applications, one for a meta-analysis of separate case-control studies of six distinct cancers and another for pooled analysis of a case-control study of glioma, a class of brain tumors that contains heterogeneous subtypes. Both the applications and additional simulation studies demonstrate that the proposed methods offer improved power and more interpretable results when compared to traditional methods for the analysis of heterogeneous traits. The proposed framework has applications beyond genetic association studies.
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| 63. |
- Björkblom, Benny, et al.
(författare)
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Distinct metabolic hallmarks of WHO classified adult glioma subtypes
- 2022
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Ingår i: Neuro-Oncology. - : Oxford University Press. - 1522-8517 .- 1523-5866. ; 24:9, s. 1454-1468
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Gliomas are complex tumors with several genetic aberrations and diverse metabolic programs contributing to their aggressive phenotypes and poor prognoses. This study defines key metabolic features that can be used to differentiate between glioma subtypes, with potential for improved diagnostics and subtype targeted therapy.METHODS: Cross-platform global metabolomic profiling coupled with clinical, genetic, and pathological analysis of glioma tissue from 224 tumors - oligodendroglioma (n=31), astrocytoma (n=31) and glioblastoma (n=162) - were performed. Identified metabolic phenotypes were evaluated in accordance with the WHO classification, IDH-mutation, 1p/19q-codeletion, WHO-grading 2-4, and MGMT promoter methylation.RESULTS: Distinct metabolic phenotypes separate all six analyzed glioma subtypes. IDH-mutated subtypes, expressing 2-hydroxyglutaric acid, were clearly distinguished from IDH-wildtype subtypes. Considerable metabolic heterogeneity outside of the mutated IDH pathway were also evident, with key metabolites being high expression of glycerophosphates, inositols, monosaccharides and sugar alcohols and low levels of sphingosine and lysoglycerophospholipids in IDH-mutants. Among the IDH-mutated subtypes, we observed high levels of amino acids, especially glycine and 2-aminoadipic acid, in grade 4 glioma, and N-acetyl aspartic acid in low-grade astrocytoma and oligodendroglioma. Both IDH-wildtype and mutated oligodendroglioma and glioblastoma were characterized by high levels of acylcarnitines, likely driven by rapid cell growth and hypoxic features. We found elevated levels of 5-HIAA in gliosarcoma and a subtype of oligodendroglioma not yet defined as a specific entity, indicating a previously not described role for the serotonin pathway linked to glioma with bimorphic tissue.CONCLUSION: Key metabolic differences exist across adult glioma subtypes.
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| 64. |
- Björkblom, Benny, et al.
(författare)
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Pre-diagnostic plasma metabolites linked to future brain tumor development
- 2018
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Ingår i: Neuro-Oncology. - : Oxford University Press. - 1522-8517 .- 1523-5866. ; 20, s. 288-289
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- BACKGROUND: The Northern Sweden Health and Disease Study is a unique population-based biobank linked to the clinical data registries. The samples originate from over 133 000 individuals living in the northern part of Sweden, and primarily collected during health checkups from the age of 40 years. Our project aims to investigate alterations in metabolite signatures in blood plasma of healthy blood donors that later in life developed a tumor. Brain tumors, especially glioblastoma is associated with poor prognosis. To explore early events of metabolic reprograming linked to future diagnosis, we investigated alterations in metabolite concentrations in plasma collected several years before diagnosis with matched healthy controls.MATERIALS AND METHODS: In total 392 analytical samples (256 repeated timepoint and 136 single timepoint, case-control samples) were analyzed using GCTOFMS. Constrained randomization of run order was utilized to maximize information output and minimize the false discovery rate. By use of reference databases, we could with high confidence quantify and identify 150 plasma metabolites. We detected metabolites with significant alterations in concertation between pre-clinical glioma cases and healthy controls by the effect projection approach based on orthogonal partial least squares (OPLSEP).RESULTS AND CONCLUSIONS: For the repeated blood samples, we designed and applied a novel multivariate strategy for high resolution biomarker pattern discovery. We utilize the fact that we have available samples from two repeated time points prior to diagnosis for each future glioma case and their matched controls to construct a small design of experiment (DoE) of four samples for each match pair. The data for each individual DoE was evaluated by OPLS-EP to determine the effect of each individual metabolite in relation to control-case, time and their interaction. Finally, latent significance calculations by means of OPLS were used to extract and evaluate the correct latent biomarker and highlight true significance of individual metabolites. Our study presents an approach to minimize confounding effects due to systematic noise from sampling, the analytical method, as well as take into account personalized metabolic levels over time, enabling biomarker detection within a smaller sample group. We will present and discuss the latest results and biomarkers from this exploratory metabolomics study at the meeting
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| 65. |
- Brandefors, Lena, et al.
(författare)
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Prognostic factors and primary treatment for Waldenstrom macroglobulinemia : a Swedish Lymphoma Registry study
- 2018
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Ingår i: British Journal of Haematology. - : WILEY. - 0007-1048 .- 1365-2141. ; 183:4, s. 564-577
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Tidskriftsartikel (refereegranskat)abstract
- We present a nationwide prospective Swedish registry-based study of Waldenstrom macroglobulinaemia (WM), that focuses on incidence and survival in relation to clinical prognostic factors and primary systemic therapies. A total of 1511 patients with WM and lymphoplasmocytic lymphoma (LPL) were registered in the Swedish Lymphoma Registry (SLR) between 1 January 2000 and 31 December 2014. The age-adjusted incidence of WM/LPL was 11.5 per million persons per year, three times higher than the reported incidence worldwide. Medical records were retrieved for 1135 patients (75%). A retrospective review showed that 981 (86.1%) of these patients fulfilled the World Health Organization diagnostic criteria for WM and these patients were analysed further. The overall survival (OS) improved between two periods - 2000-2006 and 2007-2014 - with a five-year OS of 61% and 70%, respectively. Significant prognostic factors for OS, evaluated at the time of diagnosis, were age, elevated lactate dehydrogenase level and haemoglobin <= 115 g/l for patients receiving therapy 0-3 months after diagnosis, and age, poor performance status, haemoglobin <= 115 g/l, and female sex in "watch and wait" patients (multivariable analysis). The level of the IgM monoclonal immunoglobulin had no significant prognostic value. Rituximab included in first-line therapy was associated with improved survival.
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| 66. |
- Brandefors, Lena, 1960-
(författare)
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Waldenstrom's macroglobulinemia : population based studies of familial aggregation and prognostic factors
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundWaldenstrom’s macroglobulinemia (WM) is a rare lymphoproliferative disorder with a world-wide incidence of 3-4 patients per million persons per year. In Sweden, the incidence was about three times higher, and approximately 100 patients per year are reported to the Swedish Lymphoma Registry (SLR). Our aim was to study the WM population with focus on incidence and survival in relation to clinical prognostic factors and primary therapies (Paper I-II). We also discussed the diagnostic difficulties in patients with non-WM lymphoplasmacytic lymphoma (LPL). In Paper III-IV, we study familial WM from different aspects to better understand underlying pathogenetic factors.Patients and methodsThe patients in all four studies were collected from SLR. In papers I and II, a total of 1511 patients with WM and non-WM LPL were registered between 2000 and 2014, and medical records were retrieved for 1139 patients (75%). A retrospective review showed that 981 and 33 (after review by haematopathologist) of these patients fulfilled the World Health Organization (WHO) diagnostic criteria for WM and non-WM LPL, respectively. In Paper III and IV, we used SLR and the Northern Lymphoma Registry (NLR) for the years 1997- 2011. We identified 12 families with a family history of WM, IgM monoclonal gammopathy of undetermined significance (MGUS) and/or multiple myeloma (MM).ResultsIn paper I, the overall survival (OS) for WM improved between the two time periods, 2000-2006 and 2007-2014, with a five-year OS of 61% and 70%, respectively. Significant prognostic factors for OS at the time of diagnosis in asymptomatic patients in no need of therapy were age, poor performance status (PS), haemoglobin ≤115 g/l, and female sex. Elevated lactate dehydrogenase (LDH) level and haemoglobin ≤115 g/l were significant prognostic factors for patients receiving therapy 0-3 months after diagnosis. The level of the IgM monoclonal immunoglobulin (MI) had no significant prognostic value. Rituximab included in first-line therapy was associated with improved survival. Paper II describes the differential diagnostic difficulties in non-WM LPL, especially with Marginal Zone Lymphoma (MZL). The non-WM LPL patients had more adverse prognostic factors as elevated LDH, anaemia, and lymphocytosis at diagnosis compared to the patients with WM. Despite this, the OS did not significantly differ between the groups (P = 0.249). The median OS for non-WM LPL was 71 months and the three-year and five-year survival was 71 % and 55%, respectively. The OS and RS were worse for males than females. In Paper III, we showed that age-adjusted incidence in Norrbotten and Västerbotten for WM and non-WM LPL was higher than expected – 17.5 and 14.8 per million person and year, respectively. The corresponding figure for Sweden was 10.5 per million persons per year. Autoimmune diseases or haematological malignancies in the medical history in patients or in their relatives were reported in nine and five of the 12 families, respectively. The relatives showed a high proportion abnormal serum protein electrophoresis (SPE): 12/56 (21%) showed MGUS and 13/56 (25%) showed abnormalities in the immunoglobulin levels (i.e., subnormal levels and poly/oligoclonality). Paper IV describes hyperphosphorylated paratarg 7 (pP-7), a target of 11% of the monoclonal immunoglobulin M (IgM) in WM and MGUS of IgM type, and distribution in Sweden and in familial WM. The frequency of pP-7 seems to be in line or lower in non-familial WM (7.1%) and higher in familial WM (16.7%) in the counties of Norrbotten and Västerbotten than in earlier published studies. Positive analysis for pP-7 was shown up to 10 years before diagnosis of WM.ConclusionWe show that in a rare disease such as WM registry studies might bring new knowledge about incidence, disease characteristic, prognostic factors, treatments, and outcome. We also identified aggregation of families with WM in an effort to better understand the underlying pathogenesis
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| 67. |
- Campanella, Gianluca, et al.
(författare)
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Epigenome-wide association study of adiposity and future risk of obesity-related diseases
- 2018
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Ingår i: International Journal of Obesity. - : Nature Publishing Group. - 0307-0565 .- 1476-5497. ; 42:12, s. 2022-2035
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Tidskriftsartikel (refereegranskat)abstract
- Background: Obesity is an established risk factor for several common chronic diseases such as breast and colorectal cancer, metabolic and cardiovascular diseases; however, the biological basis for these relationships is not fully understood. To explore the association of obesity with these conditions, we investigated peripheral blood leucocyte (PBL) DNA methylation markers for adiposity and their contribution to risk of incident breast and colorectal cancer and myocardial infarction.Methods: DNA methylation profiles (Illumina Infinium® HumanMethylation450 BeadChip) from 1941 individuals from four population-based European cohorts were analysed in relation to body mass index, waist circumference, waist-hip and waistheight ratio within a meta-analytical framework. In a subset of these individuals, data on genome-wide gene expression level, biomarkers of glucose and lipid metabolism were also available. Validation of methylation markers associated with all adiposity measures was performed in 358 individuals. Finally, we investigated the association of obesity-related methylation marks with breast, colorectal cancer and myocardial infarction within relevant subsets of the discovery population.Results: We identified 40 CpG loci with methylation levels associated with at least one adiposity measure. Of these, one CpG locus (cg06500161) in ABCG1 was associated with all four adiposity measures (P=9.07×10−8 to 3.27×10−18) and lower transcriptional activity of the full-length isoform of ABCG1 (P=6.00×10−7), higher triglyceride levels (P=5.37×10−9) and higher triglycerides-to-HDL cholesterol ratio (P=1.03×10−10). Of the 40 informative and obesity-related CpG loci, two (in IL2RB and FGF18) were significantly associated with colorectal cancer (inversely, P<1.6×10−3) and one intergenic locus on chromosome 1 was inversely associated with myocardial infarction (P<1.25×10−3), independently of obesity and established risk factors.Conclusion: Our results suggest that epigenetic changes, in particular altered DNA methylation patterns, may be an intermediate biomarker at the intersection of obesity and obesity-related diseases, and could offer clues as to underlying biological mechanisms.
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| 68. |
- Chatziioannou, Aristotelis, et al.
(författare)
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Blood-based omic profiling supports female susceptibility to tobacco smoke-induced cardiovascular diseases
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- We recently reported that differential gene expression and DNA methylation profiles in blood leukocytes of apparently healthy smokers predicts with remarkable efficiency diseases and conditions known to be causally associated with smoking, suggesting that blood-based omic profiling of human populations may be useful for linking environmental exposures to potential health effects. Here we report on the sex-specific effects of tobacco smoking on transcriptomic and epigenetic features derived from genome-wide profiling in white blood cells, identifying 26 expression probes and 92 CpG sites, almost all of which are affected only in female smokers. Strikingly, these features relate to numerous genes with a key role in the pathogenesis of cardiovascular disease, especially thrombin signaling, including the thrombin receptors on platelets F2R (coagulation factor II (thrombin) receptor; PAR1) and GP5 (glycoprotein 5), as well as HMOX1 (haem oxygenase 1) and BCL2L1 (BCL2-like 1) which are involved in protection against oxidative stress and apoptosis, respectively. These results are in concordance with epidemiological evidence of higher female susceptibility to tobacco-induced cardiovascular disease and underline the potential of blood-based omic profiling in hazard and risk assessment.
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| 69. |
- Choi, Dong-Joo, et al.
(författare)
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The genomic landscape of familial glioma
- 2023
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 9:17
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Tidskriftsartikel (refereegranskat)abstract
- Glioma is a rare brain tumor with a poor prognosis. Familial glioma is a subset of glioma with a strong genetic predisposition that accounts for approximately 5% of glioma cases. We performed whole-genome sequencing on an exploratory cohort of 203 individuals from 189 families with a history of familial glioma and an additional validation cohort of 122 individuals from 115 families. We found significant enrichment of rare deleterious variants of seven genes in both cohorts, and the most significantly enriched gene was HERC2 (P = 0.0006). Furthermore, we identified rare noncoding variants in both cohorts that were predicted to affect transcription factor binding sites or cause cryptic splicing. Last, we selected a subset of discovered genes for validation by CRISPR knockdown screening and found that DMBT1, HP1BP3, and ZCH7B3 have profound impacts on proliferation. This study performs comprehensive surveillance of the genomic landscape of familial glioma.
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| 70. |
- Costas, Laura, et al.
(författare)
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Reproductive Factors, Exogenous Hormone Use, and Risk of B-Cell Non-Hodgkin Lymphoma in a Cohort of Women From the European Prospective Investigation Into Cancer and Nutrition
- 2019
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Ingår i: American Journal of Epidemiology. - : OXFORD UNIV PRESS INC. - 0002-9262 .- 1476-6256. ; 188:2, s. 274-281
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Tidskriftsartikel (refereegranskat)abstract
- The role of hormonal factors in the etiology of lymphoid neoplasms remains unclear. Previous studies have yielded conflicting results, have lacked sufficient statistical power to assess many lymphoma subtypes, or have lacked detailed information on relevant exposures. Within the European Prospective Investigation Into Cancer and Nutrition cohort, we analyzed comprehensive data on reproductive factors and exogenous hormone use collected at baseline (1992-2000) among 343,458 women, including data on 1,427 incident cases of B-cell non-Hodgkin lymphoma (NHL) and its major subtypes identified after a mean follow-up period of 14 years (through 2015). We estimated hazard ratios and 95% confidence intervals using multivariable proportional hazards modeling. Overall, we observed no statistically significant associations between parity, age at first birth, breastfeeding, oral contraceptive use, or ever use of postmenopausal hormone therapy and risk of B-cell NHL or its subtypes. Women who had undergone surgical menopause had a 51% higher risk of B-cell NHL (based on 67 cases) than women with natural menopause (hazard ratio = 1.51, 95% confidence interval: 1.17, 1.94). Given that this result may have been due to chance, our results provide little support for the hypothesis that sex hormones play a role in lymphomagenesis.
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