| 1. |
- Björn, Niclas, et al.
(author)
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Comparison of Variant Calls from Whole Genome and Whole Exome Sequencing Data Using Matched Samples
- 2018
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In: Journal of Next Generation Sequencing & Applications. - 2469-9853. ; 5:1, s. 1-8
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Journal article (peer-reviewed)abstract
- Whole exome sequencing (WES) has been extensively used in genomic research. As sequencing costs decline it is being replaced by whole genome sequencing (WGS) in large-scale genomic studies, but more comparative information on WES and WGS datasets would be valuable. Thus, we have extensively compared variant calls obtained from WGS and WES of matched germline DNA samples from 96 lung cancer patients. WGS provided more homogeneous coverage with higher genotyping quality, and identified more variants, than WES, regardless of exome coverage depth. It also called more reference variants, reflecting its power to call rare variants, and more heterozygous variants that met applied quality criteria, indicating that WGS is less prone to allelic drop outs. However, increasing WES coverage reduced the discrepancy between the WES and WGS results. We believe that as sequencing costs further decline WGS will become the method of choice even for research confined to the exome.
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| 2. |
- Björn, Niclas, et al.
(author)
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Genes and variants in hematopoiesis-related pathways are associated with gemcitabine/carboplatin-induced thrombocytopenia
- 2020
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In: The Pharmacogenomics Journal. - : Nature Publishing Group. - 1470-269X .- 1473-1150. ; 20:2, s. 179-191
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Journal article (peer-reviewed)abstract
- Chemotherapy-induced myelosuppression, including thrombocytopenia, is a recurrent problem during cancer treatments that may require dose alterations or cessations that could affect the antitumor effect of the treatment. To identify genetic markers associated with treatment-induced thrombocytopenia, we whole-exome sequenced 215 non-small cell lung cancer patients homogeneously treated with gemcitabine/carboplatin. The decrease in platelets (defined as nadir/baseline) was used to assess treatment-induced thrombocytopenia. Association between germline genetic variants and thrombocytopenia was analyzed at single-nucleotide variant (SNV) (based on the optimal false discovery rate, the severity of predicted consequence, and effect), gene, and pathway levels. These analyses identified 130 SNVs/INDELs and 25 genes associated with thrombocytopenia (P-value < 0.002). Twenty-three SNVs were validated in an independent genome-wide association study (GWAS). The top associations include rs34491125 in JMJD1C (P-value = 9.07 × 10−5), the validated variants rs10491684 in DOCK8 (P-value = 1.95 × 10−4), rs6118 in SERPINA5 (P-value = 5.83 × 10−4), and rs5877 in SERPINC1 (P-value = 1.07 × 10−3), and the genes CAPZA2 (P-value = 4.03 × 10−4) and SERPINC1 (P-value = 1.55 × 10−3). The SNVs in the top-scoring pathway “Factors involved in megakaryocyte development and platelet production” (P-value = 3.34 × 10−4) were used to construct weighted genetic risk score (wGRS) and logistic regression models that predict thrombocytopenia. The wGRS predict which patients are at high or low toxicity risk levels, for CTCAE (odds ratio (OR) = 22.35, P-value = 1.55 × 10−8), and decrease (OR = 66.82, P-value = 5.92 × 10−9). The logistic regression models predict CTCAE grades 3–4 (receiver operator characteristics (ROC) area under the curve (AUC) = 0.79), and large decrease (ROC AUC = 0.86). We identified and validated genetic variations within hematopoiesis-related pathways that provide a solid foundation for future studies using genetic markers for predicting chemotherapy-induced thrombocytopenia and personalizing treatments.
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| 3. |
- Björn, Niclas, 1990-
(author)
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Pharmacogenetic biomarkers for chemotherapy-induced adverse drug reactions
- 2019
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Doctoral thesis (other academic/artistic)abstract
- Cancer is a serious disease expected to be the world-leading cause of death in the 21st century. The use of harsh chemotherapies is motivated and accepted but, unfortunately, is often accompanied by severe toxicity and adverse drug reactions (ADRs). These occur because the classical chemotherapies’ common modes of action effectively kill and/or reduce the growth rate not only of tumour cells, but also of many other rapidly dividing healthy cells in the body. There are also considerable interindividual differences in ADRs, even between patients with similar cancers and disease stage treated with equal doses; some experience severe to life-threatening ADRs after one dose, leading to treatment delays, adjustments, or even discontinuation resulting in suboptimal treatment, while others remain unaffected through all treatment cycles. Being able to predict which patients are at high or low risk of ADRs, and to adjust doses accordingly before treatment, would probably decrease toxicity and patient suffering while also increasing treatment tolerability and effects. In this thesis, we have used next-generation sequencing (NGS) and bioinformatics for the prediction of myelosuppressive ADRs in lung and ovarian cancer patients treated with gemcitabine/carboplatin and paclitaxel/carboplatin.Paper I shows that ABCB1 and CYP2C8 genotypes have small effects inadequate for stratification of paclitaxel/carboplatin toxicity. This supports the transition to whole-exome sequencing (WES) and whole-genome sequencing (WGS). Papers II and IV, respectively, use WES and WGS, and demonstrate that genetic variation in or around genes involved in blood cell regulation and proliferation, or genes differentially expressed at chemotherapy exposure, can be used in polygenic prediction models for stratification of gemcitabine/carboplatininduced myelosuppression. Paper III reassuringly shows that WES and WGS are concordant and mostly yield comparable genotypes across the exome. Paper V proves that single-cell RNA sequencing of hematopoietic stem cells is a feasible method for elucidating differential transcriptional effects induced as a response to in vitro chemotherapy treatment.In conclusion, our results supports the transition to genome-wide approaches using WES, WGS, and RNA sequencing to establish polygenic models that combine effects of multiple pharmacogenetic biomarkers for predicting chemotherapy-induced ADRs. This approach could be applied to improve risk stratification and our understanding of toxicity and ADRs related to other drugs and diseases. We hope that our myelosuppression prediction models can be refined and validated to facilitate personalized treatments, leading to increased patient wellbeing and quality of life.
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| 4. |
- Björn, Niclas, 1990-, et al.
(author)
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Single-Cell RNA Sequencing of Hematopoietic Stem and Progenitor Cells Treated with Gemcitabine and Carboplatin.
- 2020
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In: Genes. - : MDPI. - 2073-4425. ; 11:5
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Journal article (peer-reviewed)abstract
- Treatments that include gemcitabine and carboplatin induce dose-limiting myelosuppression. The understanding of how human bone marrow is affected on a transcriptional level leading to the development of myelosuppression is required for the implementation of personalized treatments in the future. In this study, we treated human hematopoietic stem and progenitor cells (HSPCs) harvested from a patient with chronic myelogenous leukemia (CML) with gemcitabine/carboplatin. Thereafter, scRNA-seq was performed to distinguish transcriptional effects induced by gemcitabine/carboplatin. Gene expression was calculated and evaluated among cells within and between samples compared to untreated cells. Cell cycle analysis showed that the treatments effectively decrease cell proliferation, indicated by the proportion of cells in the G2M-phase dropping from 35% in untreated cells to 14.3% in treated cells. Clustering and t-SNE showed that cells within samples and between treated and untreated samples were affected differently. Enrichment analysis of differentially expressed genes showed that the treatments influence KEGG pathways and Gene Ontologies related to myeloid cell proliferation/differentiation, immune response, cancer, and the cell cycle. The present study shows the feasibility of using scRNA-seq and chemotherapy-treated HSPCs to find genes, pathways, and biological processes affected among and between treated and untreated cells. This indicates the possible gains of using single-cell toxicity studies for personalized medicine.
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| 5. |
- Björn, Niclas, 1990-, et al.
(author)
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Whole-genome sequencing and gene network modules predict gemcitabine/carboplatin-induced myelosuppression in non-small cell lung cancer patients
- 2020
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In: npj Systems Biology and Applications. - : Nature Publishing Group. - 2056-7189. ; 6:1
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Journal article (peer-reviewed)abstract
- Gemcitabine/carboplatin chemotherapy commonly induces myelosuppression, including neutropenia, leukopenia, and thrombocytopenia. Predicting patients at risk of these adverse drug reactions (ADRs) and adjusting treatments accordingly is a long-term goal of personalized medicine. This study used whole-genome sequencing (WGS) of blood samples from 96 gemcitabine/carboplatin-treated non-small cell lung cancer (NSCLC) patients and gene network modules for predicting myelosuppression. Association of genetic variants in PLINK found 4594, 5019, and 5066 autosomal SNVs/INDELs with p ≤ 1 × 10−3 for neutropenia, leukopenia, and thrombocytopenia, respectively. Based on the SNVs/INDELs we identified the toxicity module, consisting of 215 unique overlapping genes inferred from MCODE-generated gene network modules of 350, 345, and 313 genes, respectively. These module genes showed enrichment for differentially expressed genes in rat bone marrow, human bone marrow, and human cell lines exposed to carboplatin and gemcitabine (p < 0.05). Then using 80% of the patients as training data, random LASSO reduced the number of SNVs/INDELs in the toxicity module into a feasible prediction model consisting of 62 SNVs/INDELs that accurately predict both the training and the test (remaining 20%) data with high (CTCAE 3–4) and low (CTCAE 0–1) maximal myelosuppressive toxicity completely, with the receiver-operating characteristic (ROC) area under the curve (AUC) of 100%. The present study shows how WGS, gene network modules, and random LASSO can be used to develop a feasible and tested model for predicting myelosuppressive toxicity. Although the proposed model predicts myelosuppression in this study, further evaluation in other studies is required to determine its reproducibility, usability, and clinical effect.
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| 6. |
- Deventer, Marie H., et al.
(author)
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Off-target activity of NBOMes and NBOMe analogs at the mu opioid receptor
- 2023
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In: Archives of Toxicology. - : SPRINGER HEIDELBERG. - 0340-5761 .- 1432-0738. ; 97:5, s. 1367-1384
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Journal article (peer-reviewed)abstract
- New psychoactive substances (NPS) are introduced on the illicit drug market at a rapid pace. Their molecular targets are often inadequately elucidated, which contributes to the delayed characterization of their pharmacological effects. Inspired by earlier findings, this study set out to investigate the mu opioid receptor (MOR) activation potential of a large set of psychedelics, substances which typically activate the serotonin (5-HT2A) receptor as their target receptor. We observed that some substances carrying the N-benzyl phenethylamine (NBOMe) structure activated MOR, as confirmed by both the NanoBiT (R) beta arr2 recruitment assay and the G protein-based AequoScreen (R) Ca2+ release assay. The use of two orthogonal systems proved beneficial as some aspecific, receptor independent effects were found for various analogs when using the Ca2+ release assay. The specific off-target effects at MOR could be blocked by the opioid antagonist naloxone, suggesting that these NBOMes occupy the same common opioid binding pocket as conventional opioids. This was corroborated by molecular docking, which revealed the plausibility of multiple interactions of 25I-NBOMe with MOR, similar to those observed for opioids. Additionally, structure-activity relationship findings seen in vitro were rationalized in silico for two 25I-NBOMe isomers. Overall, as MOR activity of these psychedelics was only noticed at high concentrations, we consider it unlikely that for the tested compounds there will be a relevant opioid toxicity in vivo at physiologically relevant concentrations. However, small modifications to the original NBOMe structure may result in a panel of more efficacious and potent MOR agonists, potentially exhibiting a dual MOR/5-HT2A activation potential.
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| 7. |
- Elenstal, Emily, et al.
(author)
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Intralipid as a matrix additive for evaluating hyperlipidemic postmortem blood
- 2023
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In: Journal of Analytical Toxicology. - : OXFORD UNIV PRESS INC. - 0146-4760 .- 1945-2403. ; 47:6, s. 529-534
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Journal article (peer-reviewed)abstract
- Postmortem whole blood samples can differ greatly in quality where hyperlipemia is a frequent variable that can influence the results of analytical methods. The aim of this study was to investigate the influence of lipemia on postmortem analysis as well as demonstrate the usage of Intralipid in comparison to pooled postmortem lipids as matrix additives for meaningful evaluation and validation of hyperlipidemic postmortem samples. Hyperlipidemic blood samples were simulated by adding different concentrations of Intralipid or pooled authentic postmortem lipids to bovine whole blood. The hyperlipidemic blood samples were spiked with 14 benzodiazepines and five sedative and antianxiety drugs (alprazolam, clonazepam, 7-aminoclonazepam, diazepam, flunitrazepam, 7-aminoflunitrazepam, hydroxyzine, lorazepam, midazolam, nitrazepam, 7-aminonitrazepam, nordazepam, oxazepam, propiomazine, dihydropropiomazine, temazepam, triazolam, zolpidem and zopiclone). Samples were prepared with liquid-Liquid extraction followed by ultra-high performance liquid chromatography-mass spectrometry. The effects of lipemia on the recovery of analytes and internal standards (ISs) were evaluated to determine the effect of, and any differences between, the two additives. Lipemia was found to cause major interference when quantifying the analytes. For most analytes, the ISs could compensate for analyte losses. However, the most hydrophilic analytes (7-amino metabolites), together with the most lipophilic analytes (propiomazine and dihydropropiomazine), were greatly affected by lipemia (<50% recovery), and the IS could not compensate for analyte losses. In general, lower analyte recoveries were observed for samples with Intralipid as a lipemic additive in comparison to those containing pooled postmortem lipids. Both Intralipid and pooled postmortem lipids showed marked effects on the analytical results. Intralipid gave a good indication of the effects of lipemia and could be a useful tool for making a meaningful evaluation of hyperlipidemic postmortem samples during the method development and validation.
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| 8. |
- Engvall, Kristina, et al.
(author)
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Impact of persistent peripheral neuropathy on health-related quality of life among early-stage breast cancer survivors : a population-based cross-sectional study
- 2022
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In: Breast Cancer Research and Treatment. - : Springer. - 0167-6806 .- 1573-7217. ; 195, s. 379-391
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Journal article (peer-reviewed)abstract
- Background We explored the impact of persistent sensory and motor taxane-induced peripheral neuropathy (TIPN) symptoms on health-related quality of life (HRQL) among early-stage breast cancer survivors (ESBCS). Methods A population-based cohort of 884 residual-free ESBCS received a postal questionnaire, including the EORTC chemotherapy-induced PN (CIPN20) and the EORTC QLQ-C30 instruments. Mean scores of QLQ-C30 scales among ESBCS with and without TIPN were calculated and adjusted for confounding factors (age, lifestyle factors, co-morbidities; linear regression analyses). Interpretation of QLQ-C30 results were based on guidelines. Results Response rate was 79%, and 646 survivors were included in the analysis. In median, 3.6 (1.5-7.3) years had elapsed post-taxane treatment. All TIPN symptoms had a significant impact on global QoL, which worsened with increased severity of TIPN. Between 29.5% and 93.3% of ESBCS with moderate-severe TIPN reported a clinical important impairment of functioning and personal finances, 64.3-85.7% reporting "difficulty walking because of foot drop," and 53.1-81.3% reporting "problems standing/walking because of difficulty feeling ground under feet" had impaired functioning/finances. The difference in mean scores between affected and non-affected survivors was highest for "numbness in toes/feet" and "difficulty walking because of foot drop." Moderate-severe "difficulty climbing stairs or getting out of chair because of weakness of legs" and "problems standing/walking because of difficulty feeling ground under feet" were associated with the largest clinically important differences on all scales. Conclusion Persistent sensory and motor TIPN is associated with clinically relevant impairment of global QoL, functioning, and personal finances among ESBCS, which increased with level of TIPN severity.
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| 9. |
- Engvall, Kristina, 1978-
(author)
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Taxane-Induced Peripheral Neuropathy among Early-Stage Breast Cancer Survivors : Prevalence, Risk Factors, Quality of Life and Genetic Prediction Models
- 2024
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Doctoral thesis (other academic/artistic)abstract
- Background: Taxane-induced peripheral neuropathy (TIPN) is a common and distressful side effect. Little is known on how long TIPN persist and its effect on health-related quality of life (HRQL). The overall aim of this thesis was to study the prevalence and severity of persistent TIPN, to investigate its impact on HRQL and to explore the clinical and genetic risk factors for TIPN among early-stage breast cancer survivors (ESBCS). Methods: A population-based cohort of 884 recurrence-free ESBCS diagnosed 2010-2015 in the Southeast Health Care region, Sweden and 1768 control women without prior cancer, who received a postal questionnaire including EORTC chemotherapy-induced peripheral neuropathy (CIPN20) and QLQ-C30 instruments. Prevalence of TIPN symptoms and clinical risk factors were explored. Adjusted relative risks (RR) were estimated for ESBCS compared to control women. For impact on HRQL, adjusted mean scores of QLQ-C30 scales among ESBCS with and without TIPN were calculated. Blood samples from 362 ESBCS were whole-exome sequenced. We leveraged logistic regression models to develop and validate polygenic prediction models to estimate the risk of persistent PN symptoms in a training and test cohort. Results: The response rate was 79% for ESBCS and 59% for controls. The median time post-taxane was 3.6 years. The adjusted RR for ESBCS vs. controls was highest (RR 1.8) for tingling in feet and numbness in feet. Individual sensory symptoms occurred in 9%-48% and motor symptoms in 7%-61% of ESBCS. The most prevalent symptoms were difficulty opening jar and cramps in feet. Paclitaxel, older age, overweight, diabetes mellitus, vibrating hand tools, smoking and autoimmune disease were independent risk factors (Study I). All 13 sensory and motor TIPN symptoms at increased risks among ESBCS had a significant impact on global health status, which worsened with increased severity of TIPN. Between 30%-93% of ESBCS with moderate-severe TIPN reported a clinically important impairment of functioning and personal finances. Moderate-severe difficulty climbing stairs and problems standing/walking were associated with medium-large clinically important differences (Study II). In the explorative sub-study, two of five prediction models based on genetic and clinical risk factors obtained AUC results above 60% in the test cohort. Using the model for numbness in feet (35 SNVs) in the test cohort, 73% survivors were correctly predicted. For tingling in feet (55 SNVs) 70% were correctly predicted (Study III).Conclusions: Most sensory and motor symptoms are more common among taxane-treated ESBC survivors than in women from the general population, many symptoms persist ≥3.6 years. Persistent TIPN symptoms are associated with clinically relevant impairment of HRQL. Polygenic prediction models including clinical risk factors may be used to estimate the risk of persistent taxane-induced numbness in feet and tingling in feet.
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| 10. |
- Fritzson, Peter, et al.
(author)
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Biochemical Mathematical Modeling with Modelica and the BioChem Library
- 2007
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Conference paper (peer-reviewed)abstract
- Considering the large amounts of data that is nowadays produced in the biochemistry (functional genomics) it is difficult to extract the information from the measurements. There is currently also a great interest in the development of novel analytical technologies for rapid screening of disease symptoms in pharmaceutical and clinical ap-plications. Modeling and simulation can provide a useful help in understanding the rela-tions of the measured substances and to minimize the need for measurements. The Bio-Chem library presented here is the first free Modelica library available for mathematical modeling of biochemical processes. Three examples are shown to illustrate the library. First, a simple insulin model is presented. Then a simplified model of cholesterol to-gether with simulations are shown. Next, a simple drug model together with parameter estimation in NONMEN are presented. The BioChem library allows for fast and end-user friendly modeling of biomedical systems. The graphical user interface provides graphics similar to that used in the description of metabolic pathways in biochemistry.
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| 11. |
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| 12. |
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| 13. |
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| 14. |
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| 15. |
- Green, Henrik, 1975-
(author)
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Pharmacogenetic Studies of Paclitaxel in Ovarian Cancer : focus on interindividual differences in pharmacodynamics and pharmacokinetics
- 2007
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Doctoral thesis (other academic/artistic)abstract
- Ovarian cancer is one of the most common female cancer diseases in the world today and in Sweden more than 800 new cases are diagnosed every year. The standard treatment consists of chemotherapy with paclitaxel in combination with carboplatin after initial cytoreductive surgery. The response to treatment and the severity of adverse drug reactions after chemotherapy varies greatly among individuals, and one of the most important factors responsible for these differences is now recognized to be the genetic variability. One of the major obstacles to successful treatment is drug resistance. Several potential mechanisms have been suggested for the resistance to paclitaxel, such as mutations in the target protein β-tubulin, single nucleotide polymorphisms (SNPs) in the gene ABCB1, which encodes the transport protein P-glycoprotein. P-glycoprotein can mediate efflux of various drugs from cancer cells as well as from the circulation into the intestinal lumen, and overexpression and/or high activity leads to drug resistance and/or increased elimination. Another reason might be the high interindividual variability of paclitaxel plasma concentrations, which has been suggested to be influenced by variability in metabolic enzymes, such as CYP2C8 and CYP3A4, and transport proteins e.g. P-glycoprotein.In the studies constituting this thesis we have investigated the possibilities of predicting the pharmacokinetics of paclitaxel as well as the tumor response and adverse drug reactions after chemotherapy in the preparation of personalized chemotherapy. We studied the correlation between the response and the presence of mutations in the dominant β-tubulin gene and SNPs in ABCB1. DNA from 40 ovarian tumors was screened for sequence variations in the β-tubulin gene without finding any, showing that β-tubulin mutations are rare and unlikely to be a clinically relevant resistance mechanism for paclitaxel. The SNPs G2677T/A and C3435T in the ABCB1 gene were determined in 53 ovarian cancer tumors from patients with poor (progressive disease or relapse within one year) or good (disease-free survival of more than one year) response to paclitaxel-carboplatin chemotherapy. Patients homozygously mutated for G2677T/A had a higher probability of responding to chemotherapy. There was also a dose-dependent influence of the number of mutated alleles on the response to paclitaxel treatment. No correlation was found for the C3435T variant.By using a newly developed quantitative LC/MS method for the simultaneous determination of paclitaxel and its hydroxymetabolites in human plasma we assessed the individual elimination of paclitaxel in 33 ovarian cancer patients. The patients were genotyped for SNPs in the ABCB1, CYP2C8 and CYP3A4 genes and their in vivo CYP3A4 enzyme activity, tumor response and toxicity, especially the neurotoxicity, were determined. Patients heterozygous for G/A in position 2677 in ABCB1 had a significantly higher clearance of paclitaxel than patients with the wild type or homozygously mutated, but not compared to patients carrying the G/T alleles. A lower clearance of paclitaxel was also found for patients heterozygous for CYP2C8*3 when stratified according to the ABCB1 G2677T/A genotype. The CYP3A4 enzyme activity in vivo affected the relative influence of CYP2C8 and CYP3A4 on the metabolism, but not the total clearance of paclitaxel. The exposure to paclitaxel was correlated to the neurotoxicity, but not to the treatment response. In conclusion, our findings suggest that the SNP G2677T/A in the ABCB1 gene, but not β-tubulin mutations, might be a predictor for paclitaxel response and that the interindividual variability in paclitaxel pharmacokinetics might be predicted by ABCB1 and CYP2C8 genotypes and provide useful information for individualized chemotherapy.
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| 16. |
- Green, Henrik, 1975-
(author)
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Pharmacogenomics of importance for paclitaxel chemotherapy
- 2008
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In: Pharmacogenomics (London). - : Future Medicine Ltd. - 1462-2416 .- 1744-8042. ; 9:6, s. 671-674
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Journal article (peer-reviewed)abstract
- Paclitaxel (Taxol®) has a broad activity spectrum and is clinically used, often in combination with carboplatin, to treat breast, ovarian and lung cancer. The response to treatment and the severity of adverse drug reactions after chemotherapy varies greatly among individuals, and one of the most important factors responsible for these differences is now recognized to be the genetic variability. However, so far only genetic variants of ABCB1 have been indicated to be associated with response and pharmacokinetics of paclitaxel. Commercially, the patent on paclitaxel has expired: however, from a healthcare perspective, it would be beneficial to identify patients with risk of poor response or high risk of toxicity to reduce hospitalization costs. This artiicle focuses on the pharmacogenomic background for paclitaxel response and interindividual variability.
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| 17. |
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| 18. |
- Gundersen, Per Ole M., et al.
(author)
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Metabolite Profiling of Ortho-, Meta- and Para-Fluorofentanyl by Hepatocytes and High-Resolution Mass Spectrometry
- 2020
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In: Journal of Analytical Toxicology. - : Oxford University Press. - 0146-4760 .- 1945-2403. ; 44:2, s. 140-148
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Journal article (peer-reviewed)abstract
- New psychoactive substances are emerging on the illegal drug market. Synthetic opioids including fentanyl analogues are of special concern due to their high potency. This indicates the possibility of low drug concentrations in vivo and calls for sensitive analytical methods and identification of the most appropriate analytical targets. In this study the in vitro metabolism of ortho-, meta- and para-fluorofentanyl, three fluorinated derivatives of fentanyl, has been investigated using human hepatocytes and compared to the results from an authentic human urine sample. Based on knowledge on the metabolism of similar fentanyl analogues N-dealkylation and hydroxylation was hypothesized to be the most central pathways. The three fluorofentanyl isomers were incubated with pooled human hepatocytes at 1, 3 and 5 h. Liquid chromatography quadrupole time of flight mass spectrometry operating in data-dependent mode was used to analyse the hepatocyte samples, as well as the hydrolysed and non-hydrolysed authentic urine sample. Data were analysed by a targeted approach with a database of potential metabolites. The major metabolite formed in vitro was the N-dealkylation product norfluorofentanyl. In addition various hydroxylated metabolites, a N-oxide, dihydrodiol metabolites and a hydroxymethoxy metabolite were found. In total, 14 different metabolites were identified for each fluorofentanyl isomer. In the authentic urine sample, three metabolites were detected in addition to the ortho-fluorofentanyl parent compound, with hydroxymethoxy metabolite having the highest abundance followed by norfluorofentanyl and a metabolite hydroxylated on the ethylphenyl ring. This in vitro study showed that the metabolic pattern for ortho-, meta-, and para-fluorofentanyl was close to those previously reported for other fentanyl analogues. We suggest that the hydroxymethoxy metabolite and the metabolite hydroxylated on the ethylphenyl ring should be the metabolites primarily investigated in further studies to determine the most appropriate marker for intake of fluorofentanyl derivatives in urine drug screening for human subjects.
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| 19. |
- Haage, Pernilla, 1982-, et al.
(author)
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Enantioselective pharmacokinetics of tramadol and its three main metabolites; impact of CYP2D6, CYP2B6, and CYP3A4 genotype
- 2018
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In: Pharmacology Research & Perspectives. - : John Wiley & Sons. - 2052-1707. ; 6:4
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Journal article (peer-reviewed)abstract
- Tramadol is a complex drug, being metabolized by polymorphic enzymes and administered as a racemate with the (+)- and (-)-enantiomers of the parent compound and metabolites showing different pharmacological effects. The study aimed to simultaneously determine the enantiomer concentrations of tramadol, O-desmethyltramadol, N-desmethyltramadol, and N,O-didesmethyltramadol following a single dose, and elucidate if enantioselective pharmacokinetics is associated with the time following drug intake and if interindividual differences may be genetically explained. Nineteen healthy volunteers were orally administered either 50 or 100 mg tramadol, whereupon blood samples were drawn at 17 occasions. Enantiomer concentrations in whole blood were measured by LC-MS/MS and the CYP2D6,CYP2B6 and CYP3A4 genotype were determined, using the xTAG CYP2D6 Kit, pyrosequencing and real-time PCR, respectively. A positive correlation between the (+)/(-)-enantiomer ratio and time following drug administration was shown for all four enantiomer pairs. The largest increase in enantiomer ratio was observed for N-desmethyltramadol in CYP2D6 extensive and intermediate metabolizers, rising from about two to almost seven during 24 hours following drug intake. CYP2D6 poor metabolizers showed metabolic profiles markedly different from the ones of intermediate and extensive metabolizers, with large area under the concentration curves (AUCs) of the N-desmethyltramadol enantiomers and low corresponding values of the O-desmethyltramadol and N,O-didesmethyltramadol enantiomers, especially of the (+)-enantiomers. Homozygosity of CYP2B6 *5 and *6 indicated a reduced enzyme function, although further studies are required to confirm it. In conclusion, the increase in enantiomer ratios over time might possibly be used to distinguish a recent tramadol intake from a past one. It also implies that, even though (+)-O-desmethyltramadol is regarded the enantiomer most potent in causing adverse effects, one should not investigate the (+)/(-)-enantiomer ratio of O-desmethyltramadol in relation to side effects without consideration for the time that has passed since drug intake.
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| 20. |
- Jakobsen, Ingrid, 1984-
(author)
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Prognostic markers in acute myeloid leukemia : A candidate gene approach
- 2018
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Doctoral thesis (other academic/artistic)abstract
- The standard treatment of acute myeloid leukemia (AML) consists of induction chemotherapy, most commonly daunorubicin together with the nucleoside analogue cytarabine (Ara-C), followed by consolidation chemotherapy and in selected cases allogenic stem cell transplantation (allo-SCT). Despite a high initial response rate, a considerable proportion of all AML cases eventually suffer from relapse and the five-year overall survival rate in patients >60 years is only around 15%. Based on cytogenetic analysis, patients are divided into low risk, intermediate risk, and high-risk groups. While low risk patients have a high chance of reaching and remaining in remission after standard induction therapy, high-risk patients are likely to suffer from relapse and should be scheduled for allo-SCT when first complete remission is reached. The intermediate risk group consists of normal karyotype (NK) patients and those with karyotypes of uncertain clinical relevance, but the outcomes are heterogeneous. In NKAML patients, risk classification has improved with the addition of molecular markers including FLT3 internal tandem duplications (ITD) and mutations of NPM1 and CEBPA. Despite this development, there is a group of patients lacking reliable prognostic markers and in some cases the outcomes predicted do not match the outcomes observed, highlighting the need for additional markers. ABCB1 encodes a transporter protein responsible for the extrusion of cytotoxic compounds, including daunorubicin, over the cell membrane, and is a known resistance mechanism. Ara-C is subject to both activating and inactivating metabolic enzymes including DCK (activating), CDA and cN-II (inactivating). ABCB1, DCK, CDA and cN-II are all polymorphic, and SNPs affecting enzyme function and/or activity have potential as prognostic markers. In addition, recurrent IDH1/2 mutations lead to the expression of an enzyme with neomorphic activity associated with epigenetic alterations and disturbed differentiation. Mutations as well as a SNP in codon 105 of IDH1 have prognostic implications in AML, although the effects of different IDH mutations have been unclear. The aim of this thesis was to investigate SNPs in ABCB1 and genes associated with Ara-C metabolism, mutations in IDH1/2 and the IDH1 SNP, and their associations with treatment response and survival in AML. We show that the 1236C>T and 2677G>T SNPs in ABCB1 influence in vitro sensitivity towards AML drugs, with corresponding effects on NK-AML patient survival. These survival differences were seen mainly in patients lacking FLT3-ITD, further adding to the risk stratification. In contrast, the CDA SNPs 79A>C and -451C>T appear to influence survival mainly in FLT3-ITD positive cases. In conclusion, the above-mentioned SNPs have the potential to add important information to risk classifications especially in NK-AML patients with the ambiguous FLT3-ITD-/NPM1- or FLT3-ITD+/NPM1+ genotypes. In addition, we have shown that IDH2 R140 mutation is associated with impaired survival in AML, and that the IDH1 codon 105 SNP appears to confer a worse outcome in a subset of intermediate risk patients without FLT3-ITD. With the introduction of next generation sequencing into clinical diagnostics, IDH mutations may not only provide prognostic information but also guide the selection of patients for new drugs targeting the variant enzyme. Our results indicate that in addition to leukemia-specific mutations, constitutional SNPs may prove useful for further individualizing care-taking and should be considered when implementing these new techniques.
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| 21. |
- Jakobsson, Gerd, 1981-
(author)
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Oxycodone in Forensic Toxicology : Analytical Strategies and Interpretation
- 2022
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Doctoral thesis (other academic/artistic)abstract
- Oxycodone is a common finding in forensic casework and widely used as an analgetic. Oxycodone’s pharmacokinetic and pharmacodynamic properties make the interpretation of post mortem oxycodone blood concentrations complicated. Coadministered substances and inter-individual differences in metabolic capacity can alter the oxycodone blood concentration and thereby cause an unexpected pharmacological effect and possibly lead to negative side-effects, respiratory depression, and death. As the level of tolerance often is unknown in post mortem cases the correlation between blood concentration and effect is weak. In this thesis, the overall aim was to increase the ability to determine cause and manner of death in suspected oxycodone intoxications, by studying concentrations of oxycodone and its metabolites, CYP2D6 phenotype, as well as endogenous substances in post mortem cases. Moreover, trends and patterns in prescription and post mortem findings of substances causing pharmacodynamic and pharmacokinetic interactions with oxycodone were studied.In paper I, concentrations of oxycodone, noroxycodone, oxymorphone and noroxymorphone were determined in femoral blood from 192 post mortem cases by LC-MS/MS. Concentrations and the metabolite-to-parent drug ratio were studied in groups separated by cause of death, A) intoxication by oxycodone, B) intoxication caused by oxycodone and additional substance/s, C) intoxication where oxycodone did not contribute, D) other causes of death than intoxication. It was found that concentrations above 0.2 μg/g indicate an oxycodone intoxication but that concentrations up to 0.3 μg/g can be seen in tolerant individuals. The results also demonstrated that a low noroxycodone/oxycodone ratio indicates an oxycodone intoxication. Paper II included LC-MS/MS analysis as in paper I, and in addition, genotyping for CYP2D6 enzyme activity in 174 cases. The metabolite-to-parent drug ratios were compared between poor, intermediate, extensive, and ultra-rapid metabolizers. It was concluded that with knowledge of CYP2D6 activity the oxymorphone/oxycodone ratio could distinguish between oxycodone-related deaths and other causes of deaths. Paper III was a pharmacoepidemiological study where post mortem findings were investigated in combination with prescription records in 1081 cases to evaluate the presence of interacting drugs in oxycodone-related intoxications. One of the main findings was that pharmacodynamically interacting drugs were twice as often prescribed, and five times more common as a co-finding in oxycodone-related intoxications compared to other causes of death. An oxycodone prescription was missing in 34% of all cases, with a trend that individuals, 35 years or below, more often lacked an oxycodone prescription. In paper IV, the post mortem metabolome was explored in 934 cases to reveal possible biomarkers correlated with oxycodone intoxications. The results showed that levels of acylcarnitines, a group of endogenous substances involved in mitochondrial metabolism, were significantly decreased in oxycodone-related intoxications compared to a control group, revealing post mortem metabolome analysis as a possible complemental approach of interpretation in post mortem toxicology.In conclusion, this thesis emphasizes the importance of including metabolites in the toxicological analytical strategy to improve the interpretation in post mortem case work. Also, the applicability of pharmacogenetic analysis is highly useful in certain cases. Furthermore, the use of post mortem metabolomics is a possible future promising strategy to the early identification of oxycodone-related deaths.
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| 22. |
- Jakobsson, Gerd, 1981-, et al.
(author)
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Oxycodone-Related Deaths : The Significance of Pharmacokinetic and Pharmacodynamic Drug Interactions
- 2022
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In: European journal of drug metabolism and pharmacokinetics. - : Springer France. - 0378-7966 .- 2107-0180. ; 47, s. 259-270
-
Journal article (peer-reviewed)abstract
- Background and Objectives Oxycodone is frequently prescribed as well as detected in postmortem cases. Concurrent use of pharmacodynamically or pharmacokinetically interacting drugs can cause adverse effects or even fatal intoxication. The aims of this study were to investigate differences in prescriptions for and toxicological findings of pharmacodynamically and pharmacokinetically interacting drugs in fatal oxycodone-related intoxications and other causes of death. We also aimed to investigate the differences in prevalence of oxycodone prescriptions, and the detected postmortem oxycodone concentrations between fatal oxycodone-related intoxications and other causes of death. Methods Forensic autopsy cases (2012-2018) where oxycodone was identified in femoral blood (n = 1236) were included. Medical history and prescription data were retrieved from national databases and linked to the forensic toxicology findings. Results Oxycodone-related deaths were found to have higher blood concentrations of oxycodone (median 0.30 mu g/g vs. 0.05 mu g/g) and were less likely to have a prescription for oxycodone (OR 0.62) compared to nonintoxication deaths. Pharmacodynamically interacting drugs were prescribed in 79% and found in blood in 81% of the cases. Pharmacokinetically interacting drugs were rarely prescribed (1%). Oxycodone-related deaths were more likely to have prescriptions for a pharmacodynamically interacting drug (OR 1.7) and more often have co-findings of one or multiple pharmacodynamically interacting drugs (OR 5.6). Conclusion The results suggest that combined use of oxycodone and pharmacodynamically interacting drugs is associated with oxycodone-related death and that non-medical use of oxycodone is a potential risk factor for oxycodone-related intoxication.
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| 23. |
- Kronstrand, Robert, 1966-, et al.
(author)
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Rilmazafone: A Designer Benzodiazepine Pro-Drug Involved in Fatal Intoxications
- 2023
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In: Journal of Analytical Toxicology. - : OXFORD UNIV PRESS INC. - 0146-4760 .- 1945-2403. ; 47:7, s. 640-643
-
Journal article (peer-reviewed)abstract
- Rilmazafone is a pro-drug that can be prescribed in Japan to treat insomnia. Rilmazafone metabolizes into active compounds by a ring closure resulting in a triazolo benzodiazepine structure similar to alprazolam. In mid-2022, the National Board of Forensic Medicine in Sweden were requested to investigate two separate deaths with the suspected use of pagoclone. Packages labeled "Pagoclone" were found at each scene that was suspected to contain rilmazafone based on website information. During screening by high resolution mass spectrometry, rilmazafone metabolites were presumptively identified. Due to the lack of reference material for the active metabolites, the metabolites were synthesized in house and quantification of the compounds identified in the two autopsy cases was prompted. In Case 1, femoral blood concentrations of 7.9, 65 and 170 ng/g of the metabolites rilmazolam, N-desmethyl rilmazolam and di-desmethyl rilmazolam, respectively, were detected. Additional toxicological findings included the medications haloperidol, alimemazine, fluoxetine, olanzapine and acetaminophen. In Case 2, femoral blood concentrations of 1.7, 1.4 and 70 ng/g of rimazolam, N-desmethyl rilmazolam and di-desmethyl rilmazolam, respectively, were detected. Additional toxicological findings included loperamide, alimemazine and pregabalin. The intake of rilmazafone was determined as the cause of death in Case 1 and contributed in the Case 2.
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| 24. |
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| 25. |
- Rautio, Tobias, et al.
(author)
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An improved procedure for the synthesis of fourteen 4-OH and 3-MeO-4OH metabolites of fentanyl analogues from two intermediates on multi-gram scale
- 2022
-
In: Synthetic Communications. - : Taylor & Francis Inc. - 0039-7911 .- 1532-2432. ; 52:3, s. 392-401
-
Journal article (peer-reviewed)abstract
- Fentanyl analogues have appeared on the recreational drug market during the last ten years and caused many fatal overdoses around the world due to their high potencies. Their metabolites are of great interest for toxicology, metabolism and identification studies. According to the literature, fentanyl analogues with similar structures have similar metabolism profile. Therefore, a synthetic route that enables synthesis of the corresponding metabolites for several fentanyl analogues would be valuable. Fentanyl analogue metabolites are often polar and tailing on silica gel. Hence, the purification of these substances could be challengeable. In this work, a general synthetic route was developed and described for the multi-gram scale synthesis of 14 potential metabolites of seven fentanyl analogues. The synthetic route is concise and optimized, does not require any use of silica gel purification and is therefore convenient for large-scale synthesis. The overall yields of the metabolites were in the range of 25-57%.
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| 26. |
- Rautio, Tobias, et al.
(author)
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In vitro metabolite identification of acetylbenzylfentanyl, benzoylbenzylfentanyl, 3-fluoro-methoxyacetylfentanyl, and 3-phenylpropanoylfentanyl using LC-QTOF-HRMS together with synthesized references
- 2023
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In: Drug Testing and Analysis. - : WILEY. - 1942-7603 .- 1942-7611. ; 15:7, s. 711-729
-
Journal article (peer-reviewed)abstract
- Acetylbenzylfentanyl, benzoylbenzylfentanyl, 3-fluoro-methoxyacetylfentanyl, and 3-phenylpropanoylfentanyl are fentanyl analogs that have been reported to the European Monitoring Centre for Drugs and Drug Addiction in recent years. The aim of this study was to identify metabolic pathways and potential biomarker metabolites of these fentanyl analogs. The compounds were incubated (5 mu M) with cryopreserved hepatocytes for up to 5 h in vitro. Metabolites were analyzed with liquid chromatography-quadrupole time of flight-high-resolution mass spectrometry (LC-QTOF-HRMS). The experiments showed that acetylbenzylfentanyl, benzoylbenzylfentanyl, and 3-phenylpropanoylfentanyl were mainly metabolized through N-dealkylation (forming nor-metabolites) and 3-fluoro-methoxyacetylfentanyl mainly through demethylation. Other observed metabolites were formed by mono-/dihydroxylation, dihydrodiol formation, demethylation, dehydrogenation, amide hydrolysis, and/or glucuronidation. The experiments showed that a large number of metabolites of 3-phenylpropanoylfentanyl were formed. The exact position of hydroxy groups in formed monohydroxy metabolites could not be established solely based upon recorded MSMS spectra of hepatocyte samples. Therefore, potential monohydroxy metabolites of 3-phenylpropanoylfentanyl, with the hydroxy group in different positions, were synthesized and analyzed together with the hepatocyte samples. This approach could reveal that the beta position of the phenylpropanoyl moiety was highly favored; beta-OH-phenylpropanoylfentanyl was the most abundant metabolite after the nor-metabolite. Both metabolites have the potential to serve as biomarkers for 3-phenylpropanoylfentanyl. The nor-metabolites of acetylbenzylfentanyl, benzoylbenzylfentanyl, and 3-fluoro-methoxyacetylfentanyl do also seem to be suitable biomarker metabolites, as do the demethylated metabolite of 3-fluoro-methoxyacetylfentanyl. Identified metabolic pathways and formed metabolites were in agreement with findings in previous studies of similar fentanyl analogs.
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| 27. |
- Sidstedt, Maja, et al.
(author)
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Assessing the GeneRead SNP panel for analysis of low-template and PCR-inhibitory samples
- 2017
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In: Forensic Science International: Genetics Supplement Series. - : Elsevier BV. - 1875-1768 .- 1875-175X. ; 6, s. 267-269
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Journal article (peer-reviewed)abstract
- Massive parallel sequencing (MPS) is increasingly used for human identification purposes in forensic DNA laboratories. Forensic DNA samples are by nature heterogeneous and of varying quality, both concerning DNA integrity and matrices, creating a need for assays that can handle low amounts of DNA as well as impurities. Commercial short tandem repeat (STR) analysis kits for capillary electrophoresis-based separation have evolved drastically over the past years to handle low-template samples and high amounts of various PCR inhibitors. If MPS is to be used extensively in forensic laboratories there is a need to ascertain a similar performance. We have evaluated the GeneRead Individual Identity SNP panel (Qiagen) that includes 140 SNP markers, following the GeneRead DNAseq Targeted Panels V2 handbook for library preparation, applying low levels of DNA and relevant impurities. Analysis of down to 0.1 ng DNA generated SNP profiles with at least 85% called SNPs, after increasing the number of PCR cycles in the initial PCR from 20 to 24. The SNP assay handled extracts from four different DNA extraction methods, including Chelex with blood and saliva, without detrimental effects. Further, the assay was shown to tolerate relevant amounts of inhibitor solutions from soil, cigarettes, snuff and chewing gum. In conclusion, the performance of the SNP panel was satisfactory for casework-like samples.
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| 28. |
- Stalberga, Darta, et al.
(author)
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Metabolism studies of 4 Cl-CUMYL-PINACA, 4 F-CUMYL-5F-PINACA and 4 F-CUMYL-5F-PICA using human hepatocytes and LC-QTOF-MS analysis
- 2023
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In: Basic & Clinical Pharmacology & Toxicology. - : WILEY. - 1742-7835 .- 1742-7843. ; 132:3, s. 263-280
-
Journal article (peer-reviewed)abstract
- 4 Cl-cumyl-PINACA (SGT-157), 4 F-cumyl-5F-PINACA (4F-cumyl-5F-PINACA, SGT-65) and 4 F-cumyl-5F-PICA (4F-cumyl-5F-PICA, SGT-64) are a series of new halogenated cumyl synthetic cannabinoid receptor agonists (SCRAs). Due to rapid metabolism, monitoring and screening for SCRAs in biological matrices requires identification of their metabolites. It is an essential tool for estimating their spread and fluctuations in the global illicit market. The purpose of this study was to identify human biotransformations of 4 Cl-cumyl-PINACA, 4 F-cumyl-5F-PINACA and 4 F-cumyl-5F-PICA in vitro and characterize for the first time the metabolic pathways of halogenated cumyl SCRAs. 4 Cl-cumyl-PINACA, 4 F-cumyl-5F-PINACA and 4 F-cumyl-5F-PICA were incubated with human hepatocytes in duplicates for 0, 1, 3 and 5 h. The supernatants were analysed in data-dependent acquisition on a UHPLC-QToF-MS, and the potential metabolites were tentatively identified. A total of 11 metabolites were detected for 4 Cl-cumyl-PINACA, 21 for 4 F-cumyl-5F-PINACA and 10 for 4 F-cumyl-5F-PICA. The main biotransformations were oxidative defluorination, followed by hydroxylation with dehydrogenation, N-dealkylation, dihydrodiol formation and glucuronidation. Hydroxylations were most common at the tail moieties with higher abundancy for indole than indazole compounds. N-dealkylations were more common for fluorinated tail chain compounds than the non-fluorinated 4 Cl-cumyl-PINACA. In conclusion, many metabolites retained halogen groups at the cumyl moieties which, in various combinations, may be suitable as analytical biomarkers.
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| 29. |
- Svedberg, Anna, 1988-, et al.
(author)
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Genetic association of gemcitabine/carboplatin-induced leukopenia and neutropenia in non-small cell lung cancer patients using whole-exome sequencing.
- 2020
-
In: Lung Cancer. - : Elsevier. - 0169-5002 .- 1872-8332. ; 147, s. 106-114
-
Journal article (peer-reviewed)abstract
- OBJECTIVES: Gemcitabine/carboplatin treatment is known to cause severe adverse drug reactions which can lead to the need for reduction or cessation of chemotherapy. It would be beneficial to identify patients at risk of severe hematological toxicity in advance before treatment start. This study aims to identify genetic markers for gemcitabine/carboplatin-induced leukopenia and neutropenia in non-small cell lung cancer patients.MATERIAL AND METHODS: Whole-exome sequencing was performed on 215 patients. Association analysis was performed on single-nucleotide variants (SNVs) and genes, and the validation was based on an independent genome-wide association study (GWAS). Based on the association and validation analyses the genetic variants were then selected for and used in weighted genetic risk score (wGRS) prediction models for leukopenia and neutropenia.RESULTS: Association analysis identified 50 and 111 SNVs, and 12 and 20 genes, for leukopenia and neutropenia, respectively. Of these SNVS 20 and 19 were partially validated for leukopenia and neutropenia, respectively. The genes SVIL (p = 2.48E-06) and EFCAB2 (p = 4.63E-06) were significantly associated with leukopenia contain the partially validated SNVs rs3740003, rs10160013, rs1547169, rs10927386 and rs10927387. The wGRS prediction models showed significantly different risk scores for high and low toxicity patients.CONCLUSION: We have identified and partially validated genetic biomarkers in SNVs and genes correlated to gemcitabine/carboplatin-induced leukopenia and neutropenia and created wGRS models for predicting the risk of chemotherapy-induced hematological toxicity. These results provide a strong foundation for further studies of chemotherapy-induced toxicity.
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| 30. |
- Svedberg, Anna, 1988-
(author)
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Toxicity and pharmacokinetic biomarkers for personalized non-small cell lung cancer treatment
- 2020
-
Doctoral thesis (other academic/artistic)abstract
- Lung cancer is the leading cause of cancer-related deaths worldwide. Unfortunately, lung cancer is usually discovered at a late stage when the curative treatment options are limited. The treatment can include surgery, radiation, chemotherapy, targeted therapy and now also immunotherapy.The challenge in cancer treatment is to eradicate cancer by the use of harsh treatments, while still, keeping the patient alive. For this purpose, treatments with severe toxicities are usually accepted but regularly lead to dose reductions or postponed treatment. Large variations in response are generally observed between patients treated with the same drug at the same dose. The dose may be adequate in one patient while ineffective or cause severe adverse drug reactions in other patients. The occurrence of drug-induced toxicities can, however, also be a positive indicator of treatment response. In personalized treatment it is of importance to select the most suitable treatment option and give it at the most favorable dose, to enable the patients to stay on treatment during the time the treatment is able to affect cancer since the tumor commonly develops resistance towards the treatment eventually.In this thesis, inter-individual variability in pharmacokinetics and toxicity for the targeted therapy erlotinib, associated with the adverse events skin rash and diarrhea was studied. Inter-individual variability in toxicity was also studied for the chemotherapy treatment gemcitabine/carboplatin linked to the hematological toxicities neutropenia and leukopenia.Erlotinib was studied in papers I-IV. Erlotinib and its metabolite concentrations were determined using a validated LC-MS/MS method. Diarrhea was associated with erlotinib and the metabolite M13, while skin rash was associated with the activity of the erlotinib metabolizing enzyme CYP3A and the ABCG2 single nucleotide polymorphism rs10856870. CYP3A was also shown to be induced during treatment. Additionally, in vitro studies showed that genetic variability in ABCG2 contributes to differences in intracellular concentrations. Genes and gene variants were found to be associated with gemcitabine/carboplatininduced toxicity in paper V. The variants were partially validated, and two models were developed to estimate the risk of leukopenia or neutropenia based on a set of genetic variants.
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| 31. |
- Svensson, Samuel, 1962-, et al.
(author)
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Melanin inhibits cytotoxic effects of doxorubicin and daunorubicin in MOLT 4 cells
- 2003
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In: Pigment Cell Research. - : Wiley. - 0893-5785 .- 1600-0749. ; 16:4, s. 351-354
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Journal article (peer-reviewed)abstract
- In the present study we have developed a simple method to elucidate the melanin binding ability of different chemotherapeutic agents. The anthracyclines, doxorubicin and daunorubicin, or the alkylating agent cisplatin were preincubated with melanin (Sepia). Melanin and free drug was then separated through centrifugation and the cytotoxic effects of corresponding drug were evaluated in a MTT (3-(4,5-dimetyltiazol-2-yl)-2,5-difenyl-tetrazoliumbromide) assay using MOLT-4 cells. Our results show that melanin pretreatment shifted the IC50 value for doxorubicin from 0.06 to 0.97 ╡M and for daunorubicin from 0.04 to 0.80 pM. In contrast, the IC50 values of cisplatin was not influenced by melanin pretreatment indicating that cisplatin does not bind to melanin. By comparing equi-active concentrations from concentration-response curves with or without melanin pretreatment an approximate binding capacity of melanin could be estimated. Our results show that melanin binds about 900 nmol/mg doxorubicin and 760 nmol/mg daunorubicin. Chloroquine, which is known to bind to melanin with high affinity, was found to inhibit melanin binding of both daunorubicin and doxorubicin, thereby leading to an increased sensitivity of the anthracyclines. The clinical implications of melanin binding regarding unwanted accumulation of anthracyclines in the skin as well as chemoprotective effects against chemotherapy are discussed.
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| 32. |
- Truver, Michael, et al.
(author)
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Urinary Pharmacokinetics of Immediate and Controlled Release Oxycodone and its Phase I and II Metabolites Using LC-MS-MS
- 2022
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In: Journal of Analytical Toxicology. - Oxford, United Kingdom : Oxford University Press. - 0146-4760 .- 1945-2403. ; 46:9, s. 1025-1031
-
Journal article (peer-reviewed)abstract
- Oxycodone (OC) is a schedule II semisynthetic opioid in the USA that is prescribed for its analgesic effects and has a high potential for abuse. Prescriptions for OC vary based on the dosage and formulation, immediate release (IR) and controlled release (CR). Monitoring OC metabolites is beneficial for forensic casework. The limited studies that involve pharmacokinetics of the urinary excretion of OC metabolites leave a knowledge gap regarding the excretion of conjugated and minor metabolites, pharmacokinetic differences by formulation, and the impact of CYP2D6 activity on the metabolism and excretion of OC. The objectives of this study were to compare urinary excretion of phase I and II metabolites by formulation and investigate if ratio changes over time could be used to predict the time of intake. Subjects (n = 7) received a single 10 mg IR tablet of Oxycodone Actavis. A few weeks later the same subjects received a single 10 mg CR tablet of Oxycodone Actavis. During each setting, urine was collected at 0, 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 9, 10, 12, 14, 24, 48 and 72 h. Urine samples (100 mu L) were diluted with 900 mu L internal standard mixture and analyzed on an Acquity UPLC® I-class coupled to a Waters Xevo TQD using a previously validated method. The CYP2D6 phenotypes were categorized as poor metabolizers (PM), intermediate metabolizers (IM), extensive metabolizers (EM) and ultrarapid metabolizers (UM). Comparisons between IR and CR were performed using two-tailed paired t-test at a significance level of P = 0.05. The metabolite ratios showed a general increase over time. Four metabolite to parent ratios were used to predict the time of intake showing that predictions were best at the early time points.
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| 33. |
- Vandeputte, Marthe M., et al.
(author)
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Characterization of recent non-fentanyl synthetic opioids via three different in vitro µ-opioid receptor activation assays
- 2022
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In: Archives of Toxicology. - : SPRINGER HEIDELBERG. - 0340-5761 .- 1432-0738. ; 96, s. 877-897
-
Journal article (peer-reviewed)abstract
- New synthetic opioids (NSOs) are one of the fastest growing groups of new psychoactive substances. Amid this dynamic landscape, insight into the pharmacology of NSOs is important to estimate the harm potential of newly emerging drugs. In this work, we determined the mu-opioid receptor (MOR) affinity and activation potential of seven poorly characterized non-fentanyl NSOs (N-ethyl-U-47700, 3,4-difluoro-U-47700, U-47931E/bromadoline, 2,4-difluoro-U-48800, U-62066/spiradoline, 2F-viminol, ketobemidone) and a panel of nine reference opioids. MOR affinity was determined via [H-3]-DAMGO binding in rat brain tissue homogenates, and was found to correlate well with different functional parameters. MOR activation potential was studied at different levels of receptor signaling using three distinct assays (NanoBiT (R) MOR-beta-arrestin2/mini-G(alpha i) and AequoScreen (R)). The most active compounds were ketobemidone (EC50 32.8-528 nM; E-max 105-271%, relative to hydromorphone) and N-ethyl-U-47700 (EC50 241-767 nM; E-max 139-247%). The same opioids showed the strongest MOR affinity. As most of the other NSOs only weakly activated MOR in the three assays (EC50 values in the high nM-mu M range), they likely do not pose a high overdose risk. 2F-viminol (EC50 2.2-4.5 mu M; E-max 21.2-61.5%) and U-47931E/bromadoline (EC50 0.55-2.9 mu M; E-max 52.8-85.9%) were partial agonists compared to hydromorphone, and maximum receptor activation was not reached for 2,4-difluoro-U-48800 (EC50 > 22 µM). We further highlight the importance of considering specific assay characteristics upon interpretation of potencies, efficacies and biased agonism. As absolute values may greatly differ between assays with varying experimental set-ups, a comparison of functional parameters to those of well-characterized reference agonists is considered the most informative.
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| 34. |
- Wallgren, Jakob, 1987-, et al.
(author)
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Structure elucidation of urinary metabolites of fentanyl and five fentanyl analogues using LC-QTOF-MS, hepatocyte incubations and synthesized reference standards
- 2020
-
In: Journal of Analytical Toxicology. - : Oxford University Press. - 0146-4760 .- 1945-2403. ; 44:9
-
Journal article (peer-reviewed)abstract
- Fentanyl analogues constitute a particularly dangerous group of new psychoactive compounds responsible for many deaths around the world. Little is known about their metabolism and studies utilizing LC-QTOF-MS analysis of hepatocyte incubations and/or authentic urine samples does not allow for determination of the exact metabolite structures, especially when it comes to hydroxylated metabolites. In this study seven motifs (2-, 3-, 4- and β-OH as well as 3,4-diOH, 4-OH-3-OMe and 3-OH-4-OMe) of fentanyl and five fentanyl analogues, acetylfentanyl, acrylfentanyl, cyclopropylfentanyl, isobutyrylfentanyl and 4F-isobutyrylfentanyl were synthesized. The reference standards were analyzed by LC-QTOF-MS, which enabled identification of the major metabolites formed in hepatocyte incubations of the studied fentanyls. By comparison with our previous data sets, major urinary metabolites could tentatively be identified. For all analogues, β-OH, 4-OH and 4-OH-3-OMe were identified after hepatocyte incubation. β-OH was the major hydroxylated metabolite for all studied fentanyls, except for acetylfentanyl where 4-OH was more abundant. However, the ratio 4-OH/β-OH was higher in urine samples than in hepatocyte incubations for all studied fentanyls. Also, 3-OH-4-OMe was not detected in any hepatocyte samples, indicating a clear preference for the 4-OH-3-OMe, which was also found to be more abundant in urine compared to hepatocytes. The patterns appear to be consistent across all studied fentanyls and could serve as a starting point in the development of methods and synthesis of reference standards of novel fentanyl analogues where nothing is known about the metabolism.
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| 35. |
- Watanabe, Shimpei, et al.
(author)
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Biotransformation of the New Synthetic Cannabinoid with an Alkene, MDMB-4en-PINACA, by Human Hepatocytes, Human Liver Microsomes, and Human Urine and Blood
- 2019
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In: AAPS Journal. - : SPRINGER. - 1550-7416. ; 22:1
-
Journal article (peer-reviewed)abstract
- Although at a slower rate, new psychoactive substances continue to appear on the illicit drug market, challenging their detection in biological specimens by forensic and clinical toxicologists. Here, we report in vitro and in vivo metabolism of a new synthetic cannabinoid, methyl 3,3-dimethyl-2-[1-(pent-4-en-1-yl)-1H-indazole-3-carboxamido] butanoate (MDMB-4en-PINACA). This is the first report on metabolism of a synthetic cannabinoid with an alkene functional group at the alkyl side chain. MDMB-4en-PINACA was incubated with both human hepatocytes and human liver microsomes (HLM) for up to 5 h and 1 h, respectively. The samples were analyzed by liquid chromatography-quadrupole time-of-flight mass spectrometry. An authentic human urine and a corresponding blood sample were analyzed to confirm the in vitro metabolites. A total of 32 metabolites were detected, of which 11 metabolites were detected in hepatocyte samples, 31 in HLM, 2 in urine, and 1 in blood. Analysis of the metabolites revealed that the main metabolic pathway of the terminal alkene group of the pentenyl side chain is dihydrodiol formation, most likely via epoxidation. The majority of the metabolites were generated from ester hydrolysis and/or dihydrodiol formation with further hydroxylation and/or dehydrogenation. Two most abundant metabolites in hepatocyte incubation samples, M8 (ester hydrolysis and dihydrodiol) and M30 (ester hydrolysis), coincided the two detected urinary metabolites. Based on the results, M8 and M30 are proposed to be appropriate urinary markers for MDMB-4en-PINACA intake for screening, while the inclusion of the parent drug itself and M29 (hydroxylation) may be useful for confirmation purposes.
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| 36. |
- Watanabe, Shimpei, et al.
(author)
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Systematic In Vitro Metabolic Profiling of the OXIZID Synthetic Cannabinoids BZO-4en-POXIZID, BZO-POXIZID, 5F-BZO-POXIZID, BZO-HEXOXIZID and BZO-CHMOXIZID
- 2023
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In: Journal of Analytical Toxicology. - : OXFORD UNIV PRESS INC. - 0146-4760 .- 1945-2403. ; 47:5, s. 455-463
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Journal article (peer-reviewed)abstract
- A new class of synthetic cannabinoids termed OXIZIDs has recently emerged on the recreational drug market. In order to continue the detection of new drugs in biological specimens, the identification of metabolites is essential. The aim of this study was to elucidate the metabolites of BZO-4en-POXIZID produced in human liver microsomes (HLMs) and human hepatocyte incubations and to compare the results with closely related analogs using the same experimental setup. Each drug was incubated for 1 h in HLM and BZO-4en-POXIZID was also incubated in human hepatocytes for up to 3 h. Subsequently, the incubates were analyzed by liquid chromatography-high-resolution mass spectrometry. BZO-4en-POXIZID metabolites were obtained in the incubation with HLMs and human hepatocytes, via the metabolic pathways of dihydrodiol formation, hydroxylation, reduction of the alkene bond and glucuronidation. The major metabolic pathway was found to be dihydrodiol formation at the pentenyl tail moiety. BZO-POXIZID, 5 F-BZO-POXIZID, BZO-HEXOXIZID and BZO-CHMOXIZID underwent similar metabolism to those reported in the literature, via the metabolic pathways of N-dealkylation, hydroxylation, ketone formation and oxidative defluorination (to alcohol or carboxylic acid). The results suggest that OXIZIDs are mainly metabolized at the N-alkyl moiety and the major metabolic pathways are hydroxylation when the N-alkyl moiety is a simple hydrocarbon, whereas functional-group-specific pathways (dihydrodiol formation and oxidative defluorination) are preferred when the moiety contains specific functional groups (alkene or fluoro), as has been observed for other synthetic cannabinoids. The major metabolites generated via these major metabolic pathways should serve as useful analytical targets for urine analysis. Furthermore, the higher abundance of glucuronidated metabolite suggests that enzymatic hydrolysis of glucuronides may be necessary for urine analysis to increase phase I metabolite concentration and improve detection.
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- Åstrand, Anna, et al.
(author)
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Activation of the μ-opioid receptor by alicyclic fentanyls : Changes from high potency full agonists to low potency partial agonists with increasing alicyclic substructure
- 2021
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In: Drug Testing and Analysis. - : John Wiley & Sons. - 1942-7603 .- 1942-7611. ; 13:1, s. 169-174
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Journal article (peer-reviewed)abstract
- Fentanyl analogs represent an important group of new psychoactive substances and knowing their efficacy and potency might assist in interpreting observed concentrations. The potency of fentanyl analogs can be estimated from in vitro studies and can be used to establish structure-activity relationships. In this study, recombinant CHO-K1 cells (AequoScreen) expressing the human μ-opioid receptor were used to establish dose-response curves via luminescent analysis for cyclopropyl-, cyclobutyl-, cyclopentyl-, cyclohexyl-, and 2,2,3,3-tetramethylcyclopropylfentanyl (TMCPF), on three separate occasions, using eight different concentrations in an eight-fold serial dilution in triplicates starting at ~60 μM. Fentanyl was used as a full agonist reference while morphine and buprenorphine were included for comparison. Cyclopropylfentanyl (EC50 = 4.3 nM), cyclobutylfentanyl (EC50 = 6.2 nM), and cyclopentylfentanyl (EC50 = 13 nM) were full agonists slightly less potent than fentanyl (EC50 = 1.7 nM). Cyclohexylfentanyl (EC50 = 3.1 μM, efficacy 48%) and TMCPF (EC50 = 1.5 μM, efficacy 65%) were partial agonists less potent than morphine (EC50 = 430 nM). Based on the results, cyclopropyl-, cyclobutyl-, and cyclopentylfentanyl would be expected to induce intoxication or cause fatal poisonings at similar concentrations to fentanyl, while the toxic or fatal concentrations of cyclohexylfentanyl and TMCPF would be expected to be much higher.
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