| 1. |
- Silins, Isabella, 1983-
(författare)
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Improved adrenocortical PET imaging
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Adrenal tumours can either be benign or malignant, hormone secreting or not, and they can be discovered through clinical examination of the patient or by pure chance. Increased knowledge in the area, plus the widespread use of imaging techniques, have resulted in a rising number of patients with adrenal tumours that subsequently need to be diagnosed. Improved imaging is needed for primary aldosteronism (PA) and adrenocortical carcinoma (ACC) but the positron emission tomography (PET) tracer currently in use, [11C]metomidate (MTO), has many important limitations. This thesis aims to improve adrenocortical PET imaging.Methods: Paper 1 investigated the pre-clinical properties of Para-Chloro-2-[18F]fluoroethyl-etomidate (CETO), by autoradiography, binding studies, ex vivo biodistribution on rats and in vivo imaging using mice and one non-human primate (NHP). Paper II investigated the clinical properties of [18F]CETO and included patients with various kinds of adrenocortical tumours, and healthy volunteers. Metabolic and kinetic analyses were performed and three out of five healthy volunteers also underwent [15O]water PET/CT to measure adrenal blood flow. Test-retest was performed on all healthy volunteers. Paper III assessed the in vivo and in-human radiation dosimetry of [18F]CETO. Ex vivo uptake data from rats and in vivo PET/CT from NHP and humans were used to calculate residence times. Paper IV evaluated the use of the block-sequential regularized expectation maximization (BSREM) reconstruction algorithm (Q.Clear, GE Healthcare, Milwaukee, USA) for [11C]MTO PET/CT in patients with PA.Results: Papers I and II demonstrated that [18F]CETO is highly specific to the adrenal cortex both in vitro and in vivo. The non-specific binding of [18F]CETO in the liver was significantly lower than that of [11C]MTO. [18F]CETO metabolizes rapidly and the single tissue irreversible (1T1k) kinetic model provided the best fit. [15O]water PET/CT results indicated that the adrenal [18F]CETO uptake was flow limited. Several retest values, including adrenal blood flow, were lower than the test values. Paper III found that the effective dose based on human data was 18.2 μSv/MBq and that the adrenal glands were the limiting organ regardless of species used. Paper IV showed that the BSREM reconstruction algorithm improves image quality, without compromising SUVmax quantification, and a β-value between 70 and 130 was found optimal.Conclusion: [18F]CETO PET/CT is a promising method for adrenocortical imaging and is safe for clinical imaging in terms of radiation dose. [18F]CETO PET/CT should be further investigated in patients with PA or ACC, preferably in conjunction with BSREM reconstruction.
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| 2. |
- Backman, Samuel, 1994-
(författare)
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Molecular studies of endocrine tumors : Insights from genetics and epigenetics
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Endocrine tumors may be benign or malignant and may occur in any of the hormone producing tissues. They share several biological characteristics, including a low mutation-burden, and may co-occur in several hereditary tumor syndromes. The aim of this thesis was to identify genetic and epigenetic aberrations in endocrine tumors.In paper I we performed a comprehensive DNA methylation analysis of 39 pheochromocytomas/paragangliomas as well as 4 normal adrenal medullae on the HumanMethylation27 BeadChip array. We validated two previously described clusters based on DNA methylation with distinct genetic associations.In Paper II we performed a transcriptomic analysis of 15 aldosterone producing adenomas. CTNNB1-mutated tumors were found to form a distinct subgroup based on gene expression and to share gene expression similarities with non-aldosterone producing adrenocortical tumors with CTNNB1 mutations, including overexpression of AFF3 and ISM1.In paper III we used whole genome sequencing to identify germline genetic variants in 14 patients with Multiple Endocrine Neoplasia type 1 previously found to be wildtype for the MEN1 gene on routine clinical testing. Three patients were found to carry previously undetected MEN1 mutations. Two patients were confirmed to have phenocopies caused by variants affecting CASR or CDC73. In total 9/14 patients were not found to have a disease-causing germline variant, suggesting that the syndrome may in some cases be due to chance co-occurrence of several sporadic tumors.In paper IV RNA-Seq and whole genome sequencing of a cohort of SI-NETs selected on the basis of unusually short or long survival was performed in order to identify disease causing genes and potential prognostic factors. We confirmed known genetic aberrations and found rare variants in known cancer driver genes. Based on gene expression two clusters that differ in prognosis were detected. Moreover, through integration of copy number variation data and gene expression, we identied novel potential disease causing genes.
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| 3. |
- Barazeghi, Elham
(författare)
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Studies of epigenetic deregulation in parathyroid tumors and small intestinal neuroendocrine tumors
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Deregulation of the epigenome is associated with the initiation and progression of various types of human cancers. Here we investigated the level of 5-hydroxymethylcytosine (5hmC), expression and function of TET1 and TET2, and DNA methylation in parathyroid tumors and small intestinal neuroendocrine tumors (SI-NETs).In Paper I, an undetectable/very low level of 5hmC in parathyroid carcinomas (PCs) compared to parathyroid adenomas with positive staining, suggested that 5hmC may represent a novel biomarker for parathyroid malignancy. Immunohistochemistry revealed that increased tumor weight in adenomas was associated with a more aberrant staining pattern of 5hmC and TET1. A growth regulatory role of TET1 was demonstrated in parathyroid tumor cells.Paper II revealed that the expression of TET2 was also deregulated in PCs, and promoter hypermethylation was detected in PCs when compared to normal parathyroid tissues. 5-aza-2′-deoxycytidine treatment of a primary PC cell culture induced TET2 expression and further supported involvement of promoter hypermethylation in TET2 gene repression. TET2 knockout demonstrated a role for TET2 in cell growth and migration, and as a candidate tumor suppressor gene.In Paper III, variable levels of 5hmC, and aberrant expression of TET1 and TET2 were observed in SI-NETs. We demonstrated a growth regulatory role for TET1, and cytoplasmic expression with absent nuclear localization for TET2 in SI-NETs. In vitro experiments supported the involvement of exportin-1 in TET2 mislocalization, and suggested that KPT-330/selinexor, an orally bioavailable selective inhibitor of exportin-1 and nuclear export, with anti-cancer effects, could be further investigated as a therapeutic option in patients with SI-NETs.In Paper IV, DNA methylation was compared between SI-NET primary tumors and metastases by reduced representation bisulfite sequencing. Three differentially methylated regions (DMR) on chromosome 18 were detected and chosen for further analyses. The PTPRM gene, at 18p11, displayed low expression in SI-NETs with high levels of methylation in the presumed CpG island shores, and in the DMR rather than the promoter region or exon 1/intron 1 boundary. PTPRM overexpression resulted in inhibition of cell growth, proliferation, and induction of apoptosis in SI-NET cells, suggesting a role for PTPRM as an epigenetically deregulated candidate tumor suppressor gene in SI-NETs.
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| 4. |
- Norlén, Olov
(författare)
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Small Intestinal Neuroendocrine Tumor : A Rare Malignancy with Favorable Outcome
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Small intestinal neuroendocrine tumor (SI-NET) is the most common small bowel tumor in Europe and USA, with an annual incidence of around 0.3-1.3/100000 persons. SI-NETs are the most common type of gastroenteropancreatic NETs (GEP-NETs), and they are known for their ability to produce hormones such as tachykinins and serotonin, as well as for their favorable long-term prognosis in comparison to gastrointestinal adenocarcinoma. The overall aim of the thesis was to investigate unknown or unclear aspects of SI-NET disease, in connection with prognosis, treatment and follow-up. Paper I confirmed several known negative prognostic factors and also showed, for the first time, that para-aortal lymph node metastases and peritoneal carcinomatosis were associated with worse survival by multivariable analyses. Locoregional surgery was associated with a low post-operative mortality, and a prolonged long-term survival by multivariable analysis. In Paper II we continued to investigate peritoneal carcinomatosis and found it be a risk factor not only for death, but also for emergency re-surgery. Furthermore, genetic analyses of samples from primary tumors in patients with and without peritoneal carcinomatosis showed a difference in the DNA between these two groups. In Paper III the outcome after liver surgery and/or radiofrequency ablation of liver metastases was investigated. To summarize, no difference in survival was seen in patients treated with surgery/radiofrequency ablation in comparison with matched controls. However, a superior radiological response of liver metasases and lower U-5-HIAA values were seen in patients subjected to liver surgery and/or radiofrequency ablation compared to matched controls. Paper IV compared ultrasonography, computed tomography and 11C-5HTP-PET in the follow-up after radiofrequency ablation of NET liver metastases. The study concluded that 11C-5HTP-PET depicted all residual tumors after RFA and that it, if used, should be combined with computed tomography for easier interpretation, as RFA areas are not clearly distinguishable with 11C-5HTP-PET alone. Paper V studied gallstone complications after somatostatin analog treatment in SI-NET patients, and concluded that there was a rather high risk to be subjected to a cholecystectomy due to biliary colic, cholecystitis, cholangitis or pancreatitis after primary surgery in somatostatin analog treated patients.
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| 5. |
- Daskalakis, Kosmas
(författare)
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Small Intestinal Neuroendocrine Tumors : Clinical Studies, Novel Serum Biomarkers and Sensitivity to Cytotoxic and Targeted Agents
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Small Intestinal Neuroendocrine Tumors (SI-NETs) are indolent neoplasms with an increasing annual incidence of approximately 1/100 000 people. They are often diagnosed at a late stage, restricting treatment efficacy. The aim of this thesis was to investigate clinical aspects of patients with advanced and/or disseminated disease with regard to clinical signs and management of abdominal fibrosis, the role of locoregional surgery and liver transplantation, as well as the ex vivo sensitivity of tumor samples to cytotoxic and targeted agents. Additionally, novel serum biomarkers for the diagnosis and prognosis of SI-NETs were investigated. In Paper I, abdominal fibrosis induced by serotonin and other cytokines from tumor cells, was associated with clinically significant symptoms of intestinal ischemia and/or obstructive uropathy, and was linked to advanced disease. Prompt recognition and minimally invasive intervention with superior mesenteric vein stenting and/or percutaneous nephrostomy and J stent treatment were effective in disease palliation. Paper II challenged the role of prophylactic, upfront locoregional surgery in Stage IV, which conferred no survival advantage in asymptomatic SI-NET patients. The option of delayed surgery as needed seemed to be comparable in all the outcomes examined, whilst also offering the advantage of fewer re-operations for intestinal obstruction in patients with already disseminated disease. Paper III confirmed that most young patients (<65 years) with SI-NET and liver metastases had a favorable survival with standardized multimodality treatment and that survival figures reported after liver transplantation for NETs do not surpass these figures. In Paper IV, 145 biomarkers were analyzed in blood serum using two different multiplex proximity assays. Subsequent ELISA and immunohistochemical analyses identified DcR3, TFF3 and midkine as novel serum biomarkers for SI-NETs. In Paper V, SI-NET samples were profiled with respect to sensitivity ex vivo to a panel of standard chemotherapeutics and targeted agents using a short-term total cell kill assay. SI-NETs exhibited variable but generally intermediate sensitivity ex vivo compared with other cancer diagnoses, calling for individualized selection of therapy.
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| 6. |
- Annerbo, Maria, 1967-
(författare)
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Calcium Homeostasis in Patients with Graves' Disease
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Patients with Graves´ Disease (GD) have a higher risk of developing more severe and prolonged hypocalcaemia after total thyroidectomy (TT) than patients who undergo surgery for benign atoxic goitre. Since TT is the most effective treatment for GD, it is crucial to identify mechanisms for postoperative hypocalcaemia. The aim of this thesis was to study the mechanisms of calcium metabolism in patients with GD.It is safe to operate on GD patients with TT. Results in Paper I showed fewer recurrences and equal complication rates compared to patients who underwent subtotal thyroidectomy (ST). The transient lowering of PTH seen in the hypocalcaemic patients was fully restored one month after surgery (Papers II and V).The calcium-sensing receptor (CaSR) is crucial for maintaining plasma calcium, and single nucleotide polymorphisms (SNPs) in the gene may alter the sensing function. Thus, we analysed SNPs in CaSR in GD patients (Paper II) and showed that they had a more left-shifted calcium-PTH set-point compared to controls, implicating higher sensitivity. This is also supported by the results in the group of postoperatively hypocalcaemic patients. They already had lower plasma calcium preoperatively (Papers II, IV and V) and lacked the T/G G/A G/C, a haplotype shown in Paper III to have a close relationship to higher p-calcium levels. Moreover, a lack of the T allele in rs1801725 was seen in the group of patients needing permanent treatment with calcium and vitamin D, i.e. > 12 months, (paper V).Patients who became hypocalcaemic (p-calcium < 2.00 mmol/L) on day one postoperatively, had lower preoperative levels of thyroid stimulating hormone (TSH) and higher levels of T3, this was also applied to the patient groups requiring temporary or permanent postoperative treatment (Papers II and V). In addition, hypocalcaemic patients treated for less than six months with anti-thyroid drugs had higher levels of bone metabolism markers CTX and P1NP than normocalcaemic patients (Paper V).In conclusion, the postoperative period of hypocalcaemia seen in patients with GD is a complex medical condition, caused by a combination of surgical trauma, different SNPs in CaSR, and high bone metabolism related to preoperative thyroid metabolism.
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| 7. |
- Halin Lejonklou, Margareta, 1966-
(författare)
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The MEN 1 Pancreas : Tumor Development and Haploinsufficiency
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Multiple Endocrine Neoplasia Type I Syndrome (MEN 1) is a monogenic autosomal dominantly inherited cancer syndrome caused by a heterozygous loss of the MEN1 gene, predisposing for endocrine cell proliferation and tumor formation. MEN 1 carriers classically develop tumors in endocrine organs; the parathyroids, the endocrine pancreas, and the pituitary. Other organs, endocrine and non-endocrine, may also be affected. The most common cause of death in MEN 1 is pancreatic endocrine tumor (PNET), which exhibit inactivation of both MEN1 alleles. The increased proliferation prior to loss of the wild-type allele indicates haploinsufficiency, and little is known concerning the mechanisms behind MEN 1 PNET development. The MEN1 protein, menin, lacking homology with other known proteins, is involved in several aspects of transcriptional regulation and chromatin organization.We report differential expression and subcellular localization of transcription factors important in pancreatic development, in human and mouse MEN 1 pancreas, compared to non-MEN 1 pancreas. A predominantly cytoplasmic localization of Neurogenin3 and NeuroD1 was observed in tumors as well as in MEN 1 non-tumorous pancreas.Notch signaling factor expression and localization were examined in the pancreas of a heterozygous Men1 mouse model, and compared with that of wild-type littermates. Nuclear Hes1 was lost in tumors, concomitant to weaker Notch1 NICD expression, and further, analyzed using qPCR, it was shown that Notch1 was less expressed in heterozygous islets compared to wild-type islets.Performing a global gene expression array, we identified differential gene expression in five-week-old heterozygous Men1 mouse islets, compared to islets from wild-type littermates. The array results for a subset of the differentially regulated genes were corroborated using qPCR, western blotting and in situ PLA. We additionally observed significantly accelerated proliferation in islets from young heterozygous animals.It is often problematic to determine prognosis for individual patients with PNET. This is especially true in the group of patients with well differentiated endocrine carcinomas. In the absence of metastases, morphological signs of malignancy are frequently lacking. We evaluated the expression of nuclear and cytoplasmic survivin in a clinically characterized patient material (n=111), and a high nuclear survivin expression proved to be a significant negative prognostic factor for survival.
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| 8. |
- Johansson, Peter, Associate professor, 1978-, et al.
(författare)
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Integrating advanced digital technologies in existing lean-based production systems : analysis of paradoxes, imbalances and management strategies
- 2024
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Ingår i: International Journal of Operations & Production Management. - : EMERALD GROUP PUBLISHING LTD. - 0144-3577 .- 1758-6593.
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Tidskriftsartikel (refereegranskat)abstract
- PurposeThe purpose of this paper is to advance the understanding of paradoxes, underlying tensions and potential management strategies when integrating digital technologies into existing lean-based production systems (LPSs), with the aim of achieving synergies and fostering the development of production systems.Design/methodology/approachThis study adopts a collaborative management research (CMR) approach to identify patterns of organisational tensions and paradoxes and explore management strategies to overcome them. The data were collected through interviews and focus group interviews with experts on lean and/or digital technologies from the companies, from documents and from workshops with the in-case researchers.FindingsThe findings of this paper provide insights into the salient organisational paradoxes embraced in the integration of digital technologies in LPS by identifying different aspects of the performing, organising, learning and belonging paradoxes. Furthermore, the findings demonstrate the intricacies and relatedness between different paradoxes and their resolutions, and more specifically, how a resolution strategy adopted to manage one paradox might unintentionally generate new tensions. This, in turn, calls for either re-contextualising actions to counteract the drift or the adoption of new resolution strategies.Originality/valueThis paper adds perspective to operations management (OM) research through the use of paradox theory, and we (1) provide a fine-grained perspective on why integration sometimes "fails" and label the forces of internal drift as mechanisms of imbalances and (2) provide detailed insights into how different management and resolution strategies are adopted, especially by identifying re-contextualising actions as a key to rebalancing organisational paradoxes in favour of the integration of digital technologies in LPSs.
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| 9. |
- Karakatsanis, Andreas, 1980-
(författare)
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Sentinel Node Biopsy for Breast Cancer : Aspects and evolution
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sentinel Node Biopsy (SNB) in clinical practice was pivotal to the shaping of modern diagnosis, staging and treatment of patients with breast cancer. The use of radioisotope (RI) and blue dye (BD) has led to high detection rates with low false negatives, but delivery-of-care limitations connected to these tracers as well as the need for methods addressing new clinical conundrums delineates the urge for new tracers with comparable performance, easier logistics and, ideally expanded implementations. Aim of the present thesis is to examine the outcomes of Superparamagnetic Iron Oxide (SPIO) nanoparticles, a new tracer based on magnetism for the detection of the sentinel nodes.Paper I is a prospective multicentre trial comparing SPIO to RI+BD, with all tracers injected at the same patient. In 206 patients, SPIO had a similar detection rate (97.6 vs 97.1%, p=0.76) whereas concordance between methods was 98%. The study was completed by a meta-analysis of similar trials published until that point. The detection rates were comparable (fixed OR:1.10; 0.67,1.79, p=0.71), and so was concordance between tracers (fixed RD: 0.00; -0.01, 0.01, p=0.82). Discoloration was present after periareolar SPIO injection in 39% of patients, almost exclusively treated with breast conservation, which reduced to 8.6% after 15 months of follow-up.Paper II was a pilot study of twelve patients with breast cancer and SNB performed where SPIO and the combination of RI+BD were injected, but SPIO was injected up to 15 days preoperatively, with total success in detection and complete concordance.Paper III tested the performance of SPIO as a sole tracer in a pragmatic double-arm non-randomised trial comparing it to the combination of RI+BD. Detection was 95.7% for SPIO and 96.8% for RI (p = 0.59). The preoperative injection of SPIO (1-27 d) enhanced SPIO specific detection (95.7 vs 86%, p=0.002).Paper IV is an interim analysis of a multicentre cohort study including patients with high-risk DCIS planned for breast conservation or any DCIS planned for mastectomy. SPIO was injected to “mark” the sentinel node but SNB was performed in a second operation only if invasive cancer was found at the first operation. In 151 included patients, this technique led to avoidance of 81.5% SNB, with a cost reduction of 14.1% for the entire cohort and 25.8% for the patients that did not have invasive cancer. The detection rate at reoperation was superior for SPIO and comparable with SNB detection at primary operation.In conclusion, SPIO is a novel tracer for SNB in breast cancer with comparable performance, fit for performance in a global setting and with wider clinical implementations compared to RI+BD.
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| 10. |
- Edfeldt, Katarina, 1979-
(författare)
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Small Intestinal Neuroendocrine Tumours : Genetic and Epigenetic Studies and Novel Serum Biomarkers
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Small intestinal neuroendocrine tumours (SI-NETs) are rare, hormone producing and proliferate slowly. Patients usually display metastases at time of diagnosis, the tumours are difficult to cure, and the disease course is unpredictable.The gene expression pattern was investigated in paper I, with emphasis on aggressive disease and tumour progression. Expression microarrays were performed on 42 tumours. Unsupervised hierarchal clustering revealed three clusters that were correlated to clinical features, and expression changes from primary tumour to metastasis. Eight novel genes, ACTG2, GREM2, REG3A, TUSC2, RUNX1, TGFBR2, TPH1 and CDH6 may be of importance for tumour progression.In paper II, expression of ACTG2 was detected in a fraction of SI-NETs, but not in normal enterochromaffin cells. Inhibition of histone methyltransferase and transfection of miR-145 induced expression and no effect was seen after DNA methylation or selective EZH2 inhibition in vitro. miR-145 expression was reduced in metastases compared to primary tumours. Overexpression of ACTG2 inhibited cell growth, and inducing ACTG2 may have therapeutic effects.TCEB3C (Elongin A3) is located on chromosome 18 and is imprinted in some tissues. In paper III a reduced protein expression was detected. The gene was epigenetically repressed by both DNA and histone methylation in a tumour tissue specific context. The expression was also induced in primary cell cultures after DNA demethylation and pyrosequencing revealed promoter region hypermethylation. Overexpression of TCEB3C inhibited cell growth by 50%, suggesting TCEB3C to be a tumour suppressor gene.In paper IV, 69 biomarkers were analysed in blood serum using multiplex proximity ligation assay. Nineteen markers displayed different levels between patients and controls. In an extended cohort, ELISA analysis showed elevated serum levels of Mindin, DcR3 and TFF3 in patients and protein expression in tumour cells. High levels of DcR3 and TFF3 were associated with poor survival, and DcR3 may be a marker for liver metastases. Mindin, DcR3, and TFF3 are potential novel diagnostic biomarkers for SI-NETs.
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