| 1. |
- Aguilar, Helena, et al.
(författare)
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VAV3 mediates resistance to breast cancer endocrine therapy
- 2014
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Ingår i: Breast Cancer Research. - : BioMed Central. - 1465-5411 .- 1465-542X. ; 16:3, s. R53-
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Endocrine therapies targeting cell proliferation and survival mediated by estrogen receptor alpha (ERalpha) are among the most effective systemic treatments for ERalpha-positive breast cancer. However, most tumors initially responsive to these therapies acquire resistance through mechanisms that involve ERalpha transcriptional regulatory plasticity. Here, we identify VAV3 as a critical component in this process.METHODS: A cell-based chemical compound screen was carried out to identify therapeutic strategies against resistance to endocrine therapy. Binding to ERalpha was evaluated by molecular docking analyses, an agonist fluoligand assay, and short-hairpin (sh) RNA-mediated protein depletion. Microarray analyses were performed to identify altered gene expression. Western blot of signaling and proliferation markers and shRNA-mediated protein depletion in viability and clonogenic assays were performed to delineate the role of VAV3. Genetic variation in VAV3 was assessed for association with the response to tamoxifen. Immunohistochemical analyses of VAV3 were carried out to determine the association with therapy response and different tumor markers. An analysis of gene expression association with drug sensitivity was carried out to identify a potential therapeutic approach based on differential VAV3 expression.RESULTS: The compound YC-1 was found to comparatively reduce the viability of cell models of acquired resistance. This effect was probably not due to activation of its canonical target (soluble guanylyl cyclase) but instead a result of binding to ERalpha. VAV3 was selectively reduced upon exposure to YC-1 or ERalpha depletion and, accordingly, VAV3 depletion comparatively reduced the viability of cell models of acquired resistance. In the clinical scenario, germline variation in VAV3 was associated with response to tamoxifen in Japanese breast cancer patients (rs10494071 combined P value = 8.4 x 10-4). The allele association combined with gene expression analyses indicated that low VAV3 expression predicts better clinical outcome. Conversely, high nuclear VAV3 expression in tumor cells was associated with poorer endocrine therapy response. Based on VAV3 expression levels and the response to erlotinib in cancer cell lines, targeting EGFR signaling may be a promising therapeutic strategy.CONCLUSIONS: This study proposes VAV3 as a biomarker and rationale signaling target to prevent and/or overcome resistance to endocrine therapy in breast cancer.
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| 2. |
- Andersen, Sören M., et al.
(författare)
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A scalable route to 5-substituted 3-isoxazolol fibrinolysis inhibitor AZD6564
- 2014
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Ingår i: Organic Process Research & Development. - : American Chemical Society (ACS). - 1083-6160 .- 1520-586X. ; 18:8, s. 952-959
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Tidskriftsartikel (refereegranskat)abstract
- A practical and chromatography-free multikilogram synthesis of a 3-isoxazolol containing antifibrinolytic agent, AZD6564, has been developed in eight steps and 7% overall yield starting from methyl 2-chloroisonicotinate. Highlights in the synthesis are a Negishi coupling and an enzymatic resolution of a racemic ester.
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| 3. |
- Baecklund, Fredrik, et al.
(författare)
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A comprehensive evaluation of the role of genetic variation in follicular lymphoma survival
- 2014
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Ingår i: BMC Medical Genetics. - : Springer Science and Business Media LLC. - 1471-2350. ; 15, s. 113-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Survival in follicular lymphoma (FL) is highly variable, even within prognostic groups defined by tumor grade and the Follicular Lymphoma International Prognostic Index. Studies suggest that germline single nucleotide polymorphisms (SNPs) may hold prognostic information but further investigation is needed. Methods: We explored the association between SNPs and FL outcome using two approaches: 1) Two independent genome-wide association studies (GWAS) of similar to 300.000 SNPs followed by a meta-analysis encompassing 586 FL patients diagnosed in Denmark/Sweden 1999-2002 and in the United States 2001-2006; and 2) Investigation of 22 candidate-gene variants previously associated with FL outcome in the Danish/Swedish cohort (N = 373). We estimated time to lymphoma-specific death (approach 1 and 2) and lymphoma progression (approach 2) with hazard ratios (HR) and 95% confidence intervals (CI) in a multivariable Cox regression model. Results: In the GWAS meta-analysis, using a random effects model, no variants were associated with lymphoma-specific death at a genome-wide significant level (p < 5.0x10(-8)). The strongest association was observed for tightly linked SNPs on 17q24 near the ABCA10 and ABCA6 genes (rs10491178 HRrandom = 3.17, 95% CI 2.09-4.79, prandom = 5.24x10(-8)). The ABCA10 and ABCA6 genes belong to a family of genes encoding for ABC transporter proteins, implicated in multidrug resistance. In line with a previous study, rs2466571 in CD46 (HR = 0.73, 95% CI 0.58-0.91, p = 0.006) showed nominal association with lymphoma progression, as did two highly linked SNPs in IL8 (rs4073 HR = 0.78, 95% CI 0.62-0.97, p = 0.02; rs2227307 HR = 0.75, 95% CI 0.60-0.94, p = 0.01) previously associated with overall survival. Conclusions: The results suggest a possible role for multidrug resistance in FL survival and add to the evidence that genetic variation in CD46 and IL8 may have prognostic implications in FL. Our findings need further confirmation in other independent populations or in a larger multicenter GWAS.
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| 4. |
- Berglund, Erik, et al.
(författare)
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Functional role of the Ca2+-activated Cl- channel DOG1/TMEM16A in gastrointestinal stromal tumor cells
- 2014
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827 .- 1090-2422. ; 326:2, s. 315-325
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Tidskriftsartikel (refereegranskat)abstract
- DOG1, a Ca2+-activated Cl- channel (CaCC), was identified in 2004 to be robustly expressed in gastrointestinal stromal tumors (GIST). It was rapidly included as a tumor marker in routine diagnostics, but the functional role remained unknown. CaCCs are important regulators of normal physiological functions, but also implicated in tumorigenesis, cancer progression, metastasis, cell migration, apoptosis, proliferation and viability in several malignancies. We therefore investigated whether DOG1 plays a role in the three latter in GIST by utilizing in vitro cell model systems. Confocal microscopy identified different subcellular localizations of DOG1 in imatinib-sensitive and imatinib-resistant cells. Electrophysiological studies confirmed that DOG1-specific pharmacological agents possess potent activating and inhibiting properties. Proliferation assays showed small effects up to 72 h, and flow cytometric analysis of adherent cells with 7-AAD/Annexin V detected no pharmacological effects on viable GIST cells. However, inhibition of DOG1 conveyed pro-apoptotic effects among early apoptotic imatinib-resistant cells. In conclusion, DOG1 generates Cl- currents in GIST that can be regulated pharmacologically, with small effects on cell viability and proliferation in vitro. Inhibition of DOG1 might act pro-apoptotic on some early apoptotic GIST cell populations. Further studies are warranted to fully illuminate the function of DOG1 and its potential as therapeutic target.
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| 5. |
- Berglund, Erik, et al.
(författare)
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Intracellular concentration of the tyrosine kinase inhibitor imatinib in gastrointestinal stromal tumor cells.
- 2014
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Ingår i: Anti-Cancer Drugs. - 0959-4973 .- 1473-5741. ; 25:4, s. 415-22
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Tidskriftsartikel (refereegranskat)abstract
- Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm in the gastrointestinal tract. In most GISTs, the underlying mechanism is a gain-of-function mutation in the KIT or the PDGFRA gene. Imatinib is a tyrosine kinase inhibitor that specifically blocks the intracellular ATP-binding sites of these receptors. A correlation exists between plasma levels of imatinib and progression-free survival, but it is not known whether the plasma concentration correlates with the intracellular drug concentration. We determined intracellular imatinib levels in two GIST cell lines: the imatinib-sensitive GIST882 and the imatinib-resistant GIST48. After exposing the GIST cells to imatinib, the intracellular concentrations were evaluated using LC-MS (TOF). The concentration of imatinib in clinical samples from three patients was also determined to assess the validity and reliability of the method in the clinical setting. Determination of imatinib uptake fits within detection levels and values are highly reproducible. The GIST48 cells showed significantly lower imatinib uptake compared with GIST882 in therapeutic doses, indicating a possible difference in uptake mechanisms. Furthermore, imatinib accumulated in the tumor tissues and showed intratumoral regional differences. These data show, for the first time, a feasible and reproducible technique to measure intracellular imatinib levels in experimental and clinical settings. The difference in the intracellular imatinib concentration between the cell lines and clinical samples indicates that drug transporters may contribute toward resistance mechanisms in GIST cells. This highlights the importance of further clinical studies to quantify drug transporter expression and measure intracellular imatinib levels in GIST patients.
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| 6. |
- Fredén Klenfeldt, Isak, 1980, et al.
(författare)
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Prevalence of Obsessive-compulsive Disorder in Relation to Depression and Cognition in an Elderly Population
- 2014
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Ingår i: The American journal of geriatric psychiatry. - : Elsevier BV. - 1064-7481. ; 22:3, s. 301-308
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Tidskriftsartikel (refereegranskat)abstract
- Objectives We examined the 1-month prevalence of obsessive-compulsive disorder (OCD) and obsessive-compulsive symptoms (OCS) not fulfilling OCD criteria in relation to sex, age, social and mental function, comorbid depression, and cognitive functioning in an elderly nondemented population. Settings and Participants Population-based sample (N = 900), stratified into two age groups: 70-year-olds (335 women and 224 men) and those aged 78 and above (341 women). Measurements Semi-structured interviews. Psychiatric symptoms were assessed with the Comprehensive Psychopathological Rating Scale and Mini-International Neuropsychiatric Interview, mental and social function with the GAF-scale, memory function with the Word Recall Task and general cognition with MMSE. OCD and Depression were diagnosed according to DSM-IV. Results The one-month prevalence of OCD was 2.9%; a further 21% had OCS. Among 70-year-olds, the prevalence of OCD was 1.3% in men and 4.5% in women. Depression was more common among those with OCD (34.6%) than among those with (12.7%) and without (8.0%) OCS. GAF-score was lower among those with OCD (74.8) and OCS (82.9) compared with individuals without obsessions and compulsions (88.2). The association between OCD and GAF-score remained after adjustment for age, sex, and depression. The OCD subgroup with checking behavior had more memory and concentration problems and did worse on Word Recall Task than other groups in our sample. Conclusions We found that OCD and OCS are common among the elderly. Both conditions are related to depression and poorer mental and social functioning. Physicians who meet elderly patients need to be aware of OCD as it is potentially treatable.
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| 7. |
- Gunnarsson, Robert, 1972-, et al.
(författare)
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Brackets and the structure sense
- 2014
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Ingår i: Development of Mathematics Teaching: Design, Scale, Effects. - Linköping : Svensk förening för MatematikDidaktisk Forskning - SMDF. - 9789197393492 ; , s. 47-55
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Konferensbidrag (refereegranskat)abstract
- Brackets are essential structure elements in mathematics expressions. However, students have shown to have scattered understanding of the concept of brackets and how they are used in mathematical expressions. In this paper we present data that illustrate students’ perceptions of the word “brackets” and how these perceptions influence their use of brackets in numerical expressions. Based on our data we argue that the teaching of the concept of brackets also need to describe brackets as ordered pairs where each symbol has a unique counterpart and that insertion of brackets can, but does not have to, modify the structure of an expression.
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| 8. |
- Hayes, Jerrard M, et al.
(författare)
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Fc Gamma Receptor Glycosylation Modulates the Binding of IgG Glycoforms : A Requirement for Stable Antibody Interactions
- 2014
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 13:12, s. 5471-5485
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Tidskriftsartikel (refereegranskat)abstract
- FcγRs play a critical role in the immune response following recognition of invading particles and tumor associated antigens by circulating antibodies. In the present study we investigated the role of FcγR glycosylation in the IgG interaction and observed a stabilizing role for receptor N-glycans. We performed a complete glycan analysis of the recombinant FcγRs (FcγRIa, FcγRIIa, FcγRIIb, FcγRIIIaPhe158/Val158, and FcγRIIIb) expressed in human cells and demonstrate that receptor glycosylation is complex and varied between receptors. We used surface plasmon resonance to establish binding patterns between rituximab and all receptors. Complex binding was observed for FcγRIa and FcγRIIIa. The IgG-FcγR interaction was further investigated using a combination of kinetic experiments and enzymatically deglycosylated FcγRIa and FcγRIIIaPhe158/Val158 receptors in an attempt to determine the underlying binding mechanism. We observed that antibody binding levels decreased for deglycosylated receptors, and at the same time, binding kinetics were altered and showed a more rapid approach to steady state, followed by an increase in the antibody dissociation rate. Binding of rituximab to deglycosylated FcγRIIIaPhe158 was now consistent with a 1:1 binding mechanism, while binding of rituximab to FcγRIIIaVal158 remained heterogeneous. Kinetic data support a complex binding mechanism, involving heterogeneity in both antibody and receptor, where fucosylated and afucosylated antibody forms compete in receptor binding and in receptor molecules where heterogeneity in receptor glycosylation plays an important role. The exact nature of receptor glycans involved in IgG binding remains unclear and determination of rate and affinity constants are challenging. Here, the use of more extended competition experiments appear promising and suggest that it may be possible to determine dissociation rate constants for high affinity afucosylated antibodies without the need to purify or express such variants. The data described provide further insight into the complexity of the IgG-FcγR interaction and the influence of FcγR glycosylation.
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| 9. |
- Karlsson, Caroline, et al.
(författare)
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Comparison of methods for predicting regolith thickness in previously glaciated terrain, Stockholm, Sweden
- 2014
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Ingår i: Geoderma. - : Elsevier BV. - 0016-7061 .- 1872-6259. ; 226, s. 116-129
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge about regolith thickness is important in several civil and environmental engineering fields. However, subsurface characteristics such as regolith thickness are difficult to determine through surface investigations and maps at regional scales. This paper presents four methods for estimating regolith thickness in a GIS environment for previously glaciated terrain with high frequency of rock outcrops: linear regression (LR) using topographical covariates; inverse distance weighting (IOW) interpolation of regolith thickness point data from well drillings: a trigonometrical approach (TA) developed for this study which uses outcrop slopes and distance between outcrops; and a simplified regolith model (SRM). The SRM is a model modified from TA which estimates the regolith thickness based on outcrops, slopes and the distance to outcrops in eight directions. The methods were compared for three study areas (Tyreso, Vallentuna and Osteraker) in Stockholm County, Sweden. Based on the results in this paper, LR proved to be the most accurate method for regolith thickness estimation, measured through root mean square error values. Whereas IDW was the most accurate method in terms of error within 2 m, which would make it a suitable model if and when large datasets of regolith point data are available. When drilling data is scarce then both the TA and SRM methods can be used for regolith estimations. However, the SRM proved to be a more accurate regolith thickness model compared to TA. SRM shows promising results and could be used at a preliminary stage in engineering projects where little or no data is available prior to detailed field investigations in previously glaciated terrain.
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| 10. |
- Karlsson, Louise, et al.
(författare)
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Mephedrone, Methylone and 3,4-Methylenedioxypyrovalerone (MDPV) Induce Conditioned Place Preference in Mice
- 2014
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Ingår i: Basic & Clinical Pharmacology & Toxicology. - : Wiley: 12 months. - 1742-7835 .- 1742-7843. ; 115:5, s. 411-416
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Tidskriftsartikel (refereegranskat)abstract
- During the last decade, there has been a worldwide increase in popularity and abuse of synthetic cathinones. Common ingredients of the so-called bath salts include mephedrone, methylone and 3,4-methylenedioxypyrovalerone (MDPV). Relatively little information about the pharmacology and addiction potential of these drugs is available. We used the conditioned place preference (CPP) paradigm to explore the reinforcing effects of three different synthetic cathinones. The primary aim of this study was to investigate whether mephedrone, methylone and MDPV induce CPP in mice. The secondary aims were to investigate a possible dose-response CPP and whether the synthetic cathinones induce higher CPP than amphetamine at equal dose. C57BL/6 mice were conditioned to mephedrone, methylone, MDPV and amphetamine at doses of 0.5, 2, 5, 10 or 20mg/kg (i.p.). During the conditioning, the mice received two training sessions per day for 4days. All four tested drugs showed a significant place preference compared with controls. Mice conditioned with MDPV (5 and 10mg/kg) displayed a greater preference score compared to mice conditioned with amphetamine (5 and 10mg/kg). Our findings show that mephedrone, methylone and MDPV produce CPP equal or higher than amphetamine strongly suggesting addictive properties. Given the public health concern of abuse, future pharmacological studies are necessary to fully understand the effects of these drugs.
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