| 1. |
- Chu, Xia, 1981-
(författare)
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Aspects of MEN1 Tumorigenesis in Endocrine Pancreas and Adrenal Glands
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Multiple endocrine neoplasia syndrome type 1 (MEN1) is an autosomal dominantly inherited disease, which is described as an association of tumors mainly in endocrine organs, including pancreas and adrenal glands. Pancreatic neuroendocrine tumors (PNETs) are the most common cause of death in MEN1 patients. More than one third of the MEN1 patients also develop enlargement of the adrenals. MEN1 is caused by a germline mutation of MEN1 gene, a tumor suppressor gene that is located on the human chromosome 11. As noticed, the MEN1 related tumors often develop prior to inactivation of both wild type alleles, indicating MEN1 haploinsufficiency. In this thesis, I utilized a conventional Men1 mouse model that has the phenotype mimicking the human MEN 1 traits, in order to investigate MEN1 tumorigenesis in endocrine pancreas and adrenal glands. The microvascular aberrations contributing to development and maintenance of PNETs were characterized. The increased vascular density of PNETs developed in the Men1 mice was paralleled by an early and extensive redistribution of pericytes within endocrine tissue. These morphological alterations were supported by fine-tuned variations in expression of several angiogenic regulators (VEGF, FGF and PDGF) and were further potentiated by hypoxia. Vascular reactivity and blood perfusion of tumor arterioles were significantly altered in response to glucose and L-nitro-arginine methyl ester.Investigation of adrenals from10-month-old Men1 mice showed 681 proteins in mass spectrometry data sets, in which 52 proteins were commonly found in the Men1+/+ and Men1+/- adrenals, and the differential expression between the genotypes reached significant levels. Prdx3, catalyzing the reduction of oxidative stress to cell survival, is one of the overexpressed proteins. Some proteins belonging to the PPARα pathway, e.g. ACLY were also overexpressed. Subsequent microRNA (miRNA) profiling analysis of adrenals from the same age group revealed 31 miRNAs whose expression was significantly altered in comparison between the genotypes. The tumor suppressor miRNAs, miR-486, miR-330 and miR-214, were significantly downregulated in Men1+/- adrenals. The latter, miR-214, is known to inhibit ACLY expression. This finding was in concordance with the proteomic analysis. The oncogene miRNAs, miR-132 and miR-494, were significantly enhanced in the Men1+/- adrenals. Gene ontology analysis demonstrated overrepresentation of the miRNA-targeted genes that are involved in nucleic acid metabolism, vasculature development, angiogenesis, and transcription. Together, these finding after validation in humans may be exploited to improve MEN1 cancer treatment.
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| 2. |
- Cui, Tao, 1982-
(författare)
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Novel Circulating and Tissue Biomarkers for Small Intestine Neuroendocrine Tumors and Lung Carcinoids
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Small intestine neuroendocrine tumors (SI-NETs) and lung carcinoids (LCs) are relatively indolent tumors, which originate from neuroendocrine (NE) cells of the diffuse NE system. Metastases can spread before diagnosis. Thus, potential cures become unavailable, which entitles new biomarker development. Indeed, we aimed at developing Ma2 autoantibodies and olfactory receptor 51E1 (OR51E1) as potential novel biomarkers and exploring other candidate protein markers in patients’ serum.First, we established a sensitive, specific and reliable anti-Ma2 indirect ELISA to distinguish SI-NET patients from healthy controls. We detected longer progression-free and recurrence-free survivals in patients expressing low anti-Ma2 titers. Moreover, a high anti-Ma2 titer was more sensitive than chromogranin A for the risk of recurrence after radical operation of SI-NET patients.We then investigated OR51E1 expression in SI-NETs and LCs. OR51E1 mRNA expression, analyzed by quantitative real-time PCR, was high in microdissected SI-NET cells, in LC cell lines and in frozen LC specimens. Immunohistochemistry (IHC) showed abundant OR51E1 protein expression in SI-NETs. OR51E1 co-expressed with vesicular-monoamine-transporter-1 in the majority of normal and neoplastic enterochromaffin cells.Furthermore, the study on LCs revealed that OR51E1, somatostatin receptor (SSTR) 2, SSTR3, and SSTR5 are expressed in 85%, 71%, 25% and 39% of typical carcinoids (TCs), whereas in 86%, 79%, 43% and 36% of atypical carcinoids (ACs). Based on the proposed IHC scoring system, in the LC cases, where all SSTR subtypes were absent, membrane OR51E1 expression was detected in 10 out of 17 TCs and 1 out of 2 ACs. Moreover, higher OR51E1 scores were detected in 5 out of 6 OctreoScan-negative LC lesions.In addition, the last presented study used a novel suspension bead array, which targeted 124 unique proteins, by using Human Protein Atlas antibodies, to profile biotinylated serum samples from SI-NET patients and healthy controls. We showed 9 proteins, IGFBP2, IGF1, SHKBP1, ETS1, IL1α, STX2, MAML3, EGR3 and XIAP as significant contributors to tumor classification.In conclusion, we proposed Ma2 autoantibodies as a sensitive circulating marker for SI-NET recurrence; OR51E1 as a candidate therapeutic target for SI-NETs; whereas as a novel diagnostic marker for LCs and 9 serum proteins as novel potential SI-NET markers.
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| 3. |
- Cunningham, Janet Lynn, 1974-
(författare)
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Tumour Biological Factors Characterizing Metastasizing Serotonin-producing Ileocaecal Carcinoids
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this study, metastasizing serotonin-producing ileocaecal carcinoid tumours (MSPCs) were examined for biological characteristics that could be used to define clinically relevant subgroups within this patient population. Possible targets for new treatment options were also explored.It was found that MSPCs share several biological characteristics such as expression of serotonin, tachykinins (TKs), chromogranin A, islet autoantigen-2 and connective tissue growth factor (CTGF). TKs and serotonin were demonstrated in the same endocrine tumours in the gut and lung. IA-2 expression was shown to be up-regulated in MSPCs, possibly in connection with active hormone secretion. CTGF expression was high in tumour areas adjacent to extensive stroma expressing alpha-smooth muscle actin. This indicated myofibroblast differentiation, which may be associated with fibrosis-related complications prevalent in patients with MSPCs. When compared with other endocrine tumours, MSPCs behaved as a relatively homogeneous group, though within the MSPC population several subgroups could be defined. Patients with tumours displaying either a solid growth pattern and/or a Ki67 index ≥1% had a less favourable prognosis than those who did not. Another group of patients, who had increased plasma TK concentrations, were more likely to suffer from severe diarrhea. This information should be considered when discussing clinical treatment and when undertaking tumour biological studies. New treatment possibilities, such as drugs that specifically target TK receptors and antibodies to CTGF, are also discussed.In conclusion, MSPCs comprise a clinically relevant tumour group with similar biological features that are distinct from other endocrine tumours. Subgroups of patients within this patient category can be defined which may be relevant when establishing prognosis and when selecting future treatment modalities.
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| 4. |
- Larsson, Dhana E
(författare)
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Analyses of Dose-Response and Mechanistic Action of Different Anti-Cancer Drugs for Neuroendocrine Tumor Cell Lines
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cancer is a disease with poor response rates on available treatments. Problems with resistance and intolerance against cancer drugs are major reasons for failure of the drugs. The need to discover new cancer drugs is important. In this thesis screening of new cancer drugs and evaluation of their mechanism of action are discussed. The aim of the thesis was to find new compounds active against neuroendocrine tumors (NETs). In paper I, we screened 1280 substances on two bronchial carcinoid cell lines and one pancreatic carcinoid cell line. Eleven of these compounds were found to have antitumor activity at low concentrations. The most active agents were brefeldin A, emetine, bortezomib and idarubicin, having IC50 values (the concentration of the drug where > 50% of the cells die) < 1μM. In addition, sanguinarine, Bay11-7085, mitoxantrone, doxorubicin, β-lapachone, NSC 95397 and CGP- 74514A were active with IC50 values < 10 μM. In paper II, additional studies have been undertaken to investigate the combination effect of the most active drugs with conventional cytotoxic drugs used in clinical practice. If synergistic or additive effects are found, drugs with different mechanism of action and toxicity profiles may be combined, making it possible to reduce the toxic effects yet maintaining the antitumor activity. In paper III, studies were undertaken to find the mechanistic action, apoptosis or necrosis, of the drugs NSC 95397, brefeldin A, bortezomib and sanguinarine in NETs. All four drugs were shown to induce caspase-3 activity and nuclear fragmentation/condensation in the neuroendocrine tumor cell lines, indicating that their antitumor activity was induction of apoptosis. In paper IV, the mechanism of action was studied for CGP-74514A and emetine. Both drugs worked by induction of apoptosis. In addition, their cytotoxic activity was studied in a three-dimensional model, the in vitro hollow fiber model. The Hollow Fiber model permits more realistic simulation of in vivo drug effects in a controlled system providing data that more accurately reflects biological responses. Our results showed that the hollow fiber model may be suitable for studies of new drugs in the neuroendocrine tumor cell lines.
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| 5. |
- Li, Su-Chen, 1979-
(författare)
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Small Intestinal Neuroendocrine Tumor Analyses : Somatostatin Analog Effects and MicroRNA Profiling
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Small intestinal neuroendocrine tumors (SI-NETs) originate from serotonin-producing enterochromaffin (EC) cells in the intestinal mucosa. Somatostatin analogs (SSAs) are mainly used to control hormonal secretion and tumor growth. However, the molecular mechanisms leading to the control of SI-NETs are unknown. Although microRNAs (miRNAs) are post transcriptional regulators deeply studied in many cancers, are not well-defined in SI-NETs. We adopted a two-pronged strategy to investigate SSAs and miRNAs: first, to provide novel insights into how SSAs control NET cells, and second, to identify an exclusive SI-NET miRNA expression, and investigate the biological functions of miRNA targets.To accomplish the first aim, we treated CNDT2.5 cells with octreotide for 16 months. Affymetrix microarray was performed to study gene variation of CNDT2.5 cells in the presence or absence of octreotide. The study revealed that octreotide induces six genes, ANXA1, ARHGAP18, EMP1, GDF15, TGFBR2 and TNFSF15.To accomplish the second aim, SI-NET tissue specimens were used to run genome-wide Affymetrix miRNA arrays. The expression of five miRNAs (miR-96, -182, -183, -196a and -200a) was significantly upregulated in laser capture microdissected (LCM) tumor cells versus LCM normal EC cells, whereas the expression of four miRNAs (miR-31, -129-5p, -133a and -215) was significantly downregulated in LCM tumor cells. We also detected nine tissue miRNAs in serum samples, showing that the expression of five miRNAs is significantly increased in SSA treated patients versus untreated patients. Conversely, SSAs do not change miRNA expression of four low expressed miRNAs. Silencing miR-196a expression was used to investigate functional activities in NET cells. This experimental approach showed that four miR-196a target genes, HOXA9, HOXB7, LRP4 and RSPO2, are significantly upregulated in silenced miR-196a NET cells.In conclusion, ANXA1, ARHGAP18, EMP1, GDF15, TGFBR2 and TNFSF15 genes might regulate cell growth and differentiation in NET cells, and play a role in an innovative octreotide signaling pathway. The global SI-NET miRNA profiling revealed that nine selected miRNAs might be involved in tumorigenesis, and play a potential role as novel markers for follow-up. Indeed, silencing miR-196a demonstrated that HOXA9, HOXB7, LRP4 and RSPO2 genes are upregulated at both transcriptional and translational levels.
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| 6. |
- Ställvik, Olof, 1975-
(författare)
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Domarrollen : Rättsregler, yrkeskultur och ideal
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The role of judges has not previously been systematically analyzed in Swedish legal research. Rather, legal scholarship has focused on the role of courts as institutions in the legal system. This is despite the fact that legal education in Sweden is often said to be focused on the methods used by judges when dealing with cases. The aim of this dissertation is to consider the professional position of judges in Sweden by applying an interdisciplinary approach. This is done by combining the legal and constitutional notions of judicial independence with theories on professionalization and de-professionalization. Empirically the investigation is based on a constitutional and historical analysis as well as in-depth interviews with eighteen Swedish judges, thereby taking a broad methodological approach. The main conclusion is that actual judicial independence can not be attained solely by legal means and instruments. In fact, legal culture (as defined by the Finnish legal scholar Kaarlo Tuori) and judicial culture (as in professional culture) are more important for the existence of judicial independence than legal rules alone. Thus, professional values are often a more important guarantee of judicial integrity, professionalism and good judgment than constitutional or legal rules. However, legal rules can be a gauge as to how judicial independence is valued and ascertained in a specific legal culture. In Sweden, the judicial professional culture has been closely linked to the executive branch of government since the early 17th century. From a constitutional perspective, this raises questions concerning the independence of the judiciary vis-à-vis the executive and, perhaps more importantly, how judges perceive themselves and their role in the larger context of the Swedish legal order and legal culture. Are judges thus the agent of the executive, the protector of civil rights, the arbitrator of disputes, or something else? Furthermore, some recent developments in administrative management have put courts and judges under pressure. Often labeled New Public Management, these tendencies have conveyed a greater focus on the economic efficiency of public management, including auditing, management by objectives, and decentralization. This focus on management and economic efficiency threatens to infringe on professional autonomy and thus on judicial independence. However, this development is somewhat countered by other developments in Swedish legal culture, notably the influence of European human rights and community law.
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| 7. |
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