1.
2.
Björn, Niclas, 1990-
(författare)
Pharmacogenetic biomarkers for chemotherapy-induced adverse drug reactions
2019
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) 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.
3.
Ljunggren, Stefan, 1988-
(författare)
Lipoproteomics : Environmental and Genetic Factors Affecting High-Density Lipoprotein (HDL)
2016
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Lipoprotein particles act as lipid transporters in the blood stream, and measuring cholesterol content in specific subclasses of lipoprotein particles has long been, and still is, a frequently used tool to estimate the risk of cardiovascular disease (CVD). High-density lipoprotein (HDL) is a subclass of lipoproteins often regarded as providing protection against CVD via several functions including reverse cholesterol transport and anti-inflammatory capacities. However, the precise relationship between HDL cholesterol levels and health outcome is still unclear. Lately, new approaches to study HDL composition and function have therefore become more important.HDL function is to a large extent dependent on its proteome, containing more than 100 proteins. Investigating the proteome in individuals with altered gene expression for HDL-associated proteins or with known exposure to environmental contaminants may reveal new insights into how HDL metabolism is affected by various factors. This is of interest in order to better understand the role of HDL in CVD.Papers I and II focus on two different mutations in a structural HDL protein, apolipoprotein A-I (L202P and K131del), and one mutation in the scavenger receptor class B-1 (P297S), which is involved in selective lipid uptake of cholesterol mainly into hepatocytes and adrenal cells. The HDL proteome was analyzed using two-dimensional gel electrophoresis and mass spectrometry. The L202P mutation was identified in HDL of the heterozygote carriers together with a significant decrease of apolipoprotein E and increased zinc-alpha-2-glycoprotein. By contrast, the second apolipoprotein AI mutation (K131del) was associated with significantly elevated alpha-1-antitrypsin and transthyretin levels. Protein analyses of the scavenger receptor class B1 P297S heterozygotes showed a significant increase in HDL apoL-1 along with increased free apoE. The carriers showed no difference in antioxidative capability but a significant increase in apoA-I methionine oxidation.Papers III and IV focus on persistent organic pollutants that may influence HDL composition and function. These compounds accumulate in humans, and exposure has been linked to an increased risk of CVD. To provide a better understanding of the HDL system in relation to pollutants, a population living in a contaminated area was studied. Persistent organic pollutants in isolated HDL were quantified using high-resolution gas chromatography mass spectrometry and significantly increased levels were found in individuals with CVD as compared to healthy controls. Furthermore, there was a significant negative association between the pollutants and paraoxonase-1 anti-oxidant activity. Studying the proteome with nano-liquid chromatography tandem mass spectrometry led to the identification of 118 proteins in HDL, of which ten were significantly associated with the persistent organic pollutants.In summary, the present studies demonstrate protein pattern alterations in HDL associated with inherited genetic variants or pollutant exposure. The studies also provide a set of methods that are useful tools to further comprehend the complexity of lipoprotein metabolism and function. The results are important in order to improve our understanding of HDL in CVD and to explain an increased risk of CVD associated with exposure to organic pollutants.
4.
Munthe, Christian, 1962
(författare)
Etiska aspekter på regenerativ medicin : Ethical aspects on regenerative medicine
2003
Ingår i: SNIB-konferensen 2003, Chalmers tekniska högskola, Göteborg, 16-18 maj 2003.
Konferensbidrag (övrigt vetenskapligt/konstnärligt) abstract
Inom den regenerativa medicinen strävar man efter att ersätta skadat eller sjukligt biologiskt mänskligt material (celler, organ, kroppsdelar) med nya biologiska komponenter. Området aktualiserar en rad etiska frågeställningar vad gäller (1) produktionen av ersättningsmaterialet (t.ex. embryonala stamceller eller införskaffande av transplantationsvävnad från donatorer), (2) risker i samband med försök på människa (genmodifierat material, material från djur), samt (3) gränserna för hur långt man bör gå i denna slags försök att förlänga människans livsspann. Föredraget ger en kort översikt över dessa frågeställningar, ståndpunkter och argument i debatten kring dem.
5.
Hörnblad, Andreas, 1982-
(författare)
Imaging the pancreas : new aspects on lobular development and adult constitution
2011
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
The mouse pancreas is a mixed exocrine and endocrine glandconsisting of three lobular compartments: the splenic, duodenal and gastric lobes. During embryogenesis, the pancreas forms from two progenitor populations located on the dorsal and ventral side of the primitive gut tube. These anlagen are brought in close proximity as the gut elongates and rotates, and fuse to form a single organ. The splenic and duodenal lobes develop from the dorsal and ventral anlagen, respectively. In the adult pancreas, exocrine tissue secretes digestive enzymes intothe gut lumen to support nutrient uptake. The endocrine Islets of Langerhans are scattered throughout the exocrine tissue and aid in regulation of energy homeostasis through the secretion of hormones. One of the key players in energy homeostasis is the pancreatic ß-cell, which is the most abundant cell type of the islets. The β-cells regulates blood glucose levels through the action of insulin. Conditions where this regulation does not function properly are gathered under the common name of Diabetes mellitus. Type 1 diabetes (T1D) is characterized by insulin deficiency due to autoimmune destruction of the ß-cells. Using recently developed protocols for optical projection tomography (OPT) whole-organ imaging, we have revealed new spatial and quantitative aspects on ß-cell mass dynamics and immune infiltration during the course of T1D development in the non-obese diabetic (NOD) mouse model. We show that although immune infiltration appears to occur asynchronously throughout the organ, smaller islets, mainly located in the periphery of the organ, preferentially loose their ß-cells during early stages of disease progression. Larger islets appear more resistant to the autoimmune attack and our data indicate the existence of a compensatory proliferative capacity within these islets. We also report the appearance of structures resembling tertiary lymphoid organs (TLOs) in association with the remaining islets during later phases of T1D progression. OPT has already proven to be a useful tool for assessments of ß-cellmass in the adult mouse pancreas. However, as with other techniques, previous protocols have relied on a tedious degree of manual postivacquisition editing. To further refine OPT-based assessment of pancreatic ß-cell mass distribution in the murine pancreas, we implemented a computational statistical approach, Contrast-Limited Adaptive Histogram Normalisation (CLAHE), to the OPT projection data of pancreata from C57Bl/6 mice. This methodology provided increased islet detection sensitivity, improved islet morphology and diminished subjectivity in thresholding for reconstruction and quantification. Using this approach, we could report a substantially higher number of islets than previously described for this strain and provide evidence of significant differences in islet mass distribution between the pancreatic lobes. The gastric lobe stood out in particular and contained a 75% higher islet density as compared to the splenic lobe. Although the development of the early pancreatic buds has been relatively well studied, later morphogenetic events are less clear and information regarding the formation of the gastric lobe has largely been missing. Using OPT we have generated a quantitative three-dimensional road map of pancreatic morphogenesis in the mouse. We show that the gastric lobe forms as a perpendicular outgrowth fromthe stem of the dorsal pancreas at around embryonic day (e) 13.5, which grows into a mesenchymal domain overlaying the pyloric sphincter and proximal part of the glandular stomach. By analyzing mutant mice with aberrant spleen development, we further demonstrate that proper formation of the gastric lobe is dependent on the initial formation of the closely positioned spleen, indicating a close interplay between pancreatic and splenic mesenchyme during development. Additionally, we show that the expression profile of markers for pancreatic multipotent progenitors within the pancreas is heterogenous with regards to lobular origin. Altogether, our studies regarding the morphogenesis and adult constitution of the mouse pancreas recognize lobular heterogeneities that add important information for future interpretations of this organ.
6.
Pfister, Anna, 1984-
(författare)
Outcomes of Myosin 1C Gene Expression Depletion on Cancer-related Pathways, in Vitro and in Clinical Samples
2016
Licentiatavhandling (övrigt vetenskapligt/konstnärligt) abstract
The unconventional myosin IC has previously been suggested to be a haploinsufficient tumour suppressor. The mechanism for this action has hitherto been unknown, however, and hence we decided to attempt to elucidate the genes involved. The first study involved knock-down of MYO1C using siRNA technology followed by whole transcriptiome microarray analysis performed on samples taken at different time points post transfection. This revealed a cornucopia of differential expressions compared to the negative control, among them we found an early up-regulation of the PI3K/AKT pathway and the pathway for prostate cancer. Among the down regulated pathways we found endometrial-, colorectal cancer and small cell lung cancer as well as the cell cycle pathway which was a little counter intuitive to the hypothesis that MYO1C suppresses cancer. For the next study six different genes (CCND1, CCND2, CDKN2B, CDKN2C, MYC, RBL1) important for the transitions into S-phase of the cell cycle were therefore chosen for validation using qPCR. These six genes and MYO1C were analysed on both the original time series and a new biological replicate as well as a well stratified set of endometrial carcinoma samples. We were able to verify the significant down-regulation of CCND2 in both time series indicating that this is caused by the depletion of MYO1C. In the tumour samples we saw a negative correlation between the expression of MYO1C and FIGO grade corroborating results previously found by our group when looking at protein expression.
7.
Andersen, Peter M.
(författare)
Is all ALS genetic?
2017
Ingår i: Neurology. - 0028-3878 .- 1526-632X. ; 89:3, s. 220-221
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
8.
9.
Ladenvall, Per, 1972
(författare)
Genetic variation at the human tissue-type plasminogen activator locus
2002
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Tissue-type plasminogen activator (tPA) is the key initiator of intravascular fibrinolysis. Family studies suggest that tPA release is regulated by hereditary factors. The aim of the present thesis was therefore to test the hypothesis that a neutral polymorphism at the tPA locus is associated with vascular release of tPA, and if so search the tPA locus for functional polymorphisms that could explain this finding. An identified genetic marker of vascular tPA release was then investigated in an association study of myocardial infarction.Vascular tPA release rates were assessed in 51 healthy males by the perfused forearm model. By this invasive procedure blood samples were simultaneously drawn from the brachial artery and vein. Net release of tPA was defined as the venoarterial plasma concentration difference times local plasma flow. In an initial study, subjects were typed for an Alu insertion polymorphism in intron eight of the tPA gene. A significant association with both basal and stimulated tPA release rates was observed. As the Alu polymorphism is neutral, this finding prompted us to search the tPA locus for putative functional variations, that could explain our observation. Regulatory and coding regions of the tPA gene were re-sequenced in 30 chromosomes and eight single nucleotide polymorphisms (SNPs) were discovered. All SNPs were typed in the 51 subjects who had taken part in invasive experi-ments as well as in 240 subjects in whom plasma levels of tPA had been determined. The results showed a high level of linkage disequilibrium among the majority of SNPs and thus, only a few common haplotypes were observed. Three of the SNPs showed a significant association with vascular release rates of tPA, but were not significantly associated with plasma levels of tPA. The closest association was observed for tPA -7,351C>T, which is located in an enhancer region upstream of the gene. Initial in vitro studies suggested a preferential binding of the transcription factor Sp1 to the C allele, which is the allele that was associated with a high tPA release rate. Since it was recently shown that Sp1 mediates induction of tPA gene transcription through the enhancer, this finding indicates that tPA -7,351C>T is functional. This SNP was therefore tested in a prospective nested case-control study on myocardial infarction in northern Sweden, which included 61 cases with a first myocardial infarction and 120 controls matched for age, sex, and geographical region. The results showed that both tPA -7,351C>T and plasma tPA antigen were associated with myocardial infarction and this association was independent of traditional risk factors. Carriers of the T allele had an increased risk of myocardial infarction.In conclusion, eight novel SNPs were identified at the tPA locus. The enhancer -7,351C>T variant, which was associated both with vascular tPA release rates and myocardial infraction, is of putative functional importance. Thus, the genetic variation at this locus appears important for physiological regulation of tPA.
10.
