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Träfflista för sökning "WFRF:(Norlén Olov) srt2:(2015-2019)"

Sökning: WFRF:(Norlén Olov) > (2015-2019)

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1.
  • Backman, Samuel, et al. (författare)
  • Detection of Somatic Mutations in Gastroenteropancreatic Neuroendocrine Tumors Using Targeted Deep Sequencing
  • 2017
  • Ingår i: Anticancer Research. - : Anticancer Research USA Inc.. - 0250-7005 .- 1791-7530. ; 37:2, s. 705-712
  • Tidskriftsartikel (refereegranskat)abstract
    • Mutations affecting the mechanistic target of rapamycin (MTOR) signalling pathway are frequent in human cancer and have been identified in up to 15% of pancreatic neuroendocrine tumours (NETs). Grade A evidence supports the efficacy of MTOR inhibition with everolimus in pancreatic NETs. Although a significant proportion of patients experience disease stabilization, only a minority will show objective tumour responses. It has been proposed that genomic mutations resulting in activation of MTOR signalling could be used to predict sensitivity to everolimus.PATIENTS AND METHODS: Patients with NETs that underwent treatment with everolimus at our Institution were identified and those with available tumour tissue were selected for further analysis. Targeted next-generation sequencing (NGS) was used to re-sequence 22 genes that were selected on the basis of documented involvement in the MTOR signalling pathway or in the tumourigenesis of gastroenterpancreatic NETs. Radiological responses were documented using Response Evaluation Criteria in Solid Tumours.RESULTS: Six patients were identified, one had a partial response and four had stable disease. Sequencing of tumour tissue resulted in a median sequence depth of 667.1 (range=404-1301) with 1-fold coverage of 95.9-96.5% and 10-fold coverage of 87.6-92.2%. A total of 494 genetic variants were discovered, four of which were identified as pathogenic. All pathogenic variants were validated using Sanger sequencing and were found exclusively in menin 1 (MEN1) and death domain associated protein (DAXX) genes. No mutations in the MTOR pathway-related genes were observed.CONCLUSION: Targeted NGS is a feasible method with high diagnostic yield for genetic characterization of pancreatic NETs. A potential association between mutations in NETs and response to everolimus should be investigated by future studies.
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2.
  • Barazeghi, Elham, et al. (författare)
  • 5-Hydroxymethylcytosine discriminates between parathyroid adenoma and carcinoma
  • 2016
  • Ingår i: Clinical Epigenetics. - : Springer Science and Business Media LLC. - 1868-7083 .- 1868-7075. ; 8
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Primary hyperparathyroidism is characterized by enlarged parathyroid glands due to an adenoma (80-85 %) or multiglandular disease (similar to 15 %) causing hypersecretion of parathyroid hormone (PTH) and generally hypercalcemia. Parathyroid cancer is rare (<1-5 %). The epigenetic mark 5-hydroxymethylcytosine (5hmC) is reduced in various cancers, and this may involve reduced expression of the ten-eleven translocation 1 (TET1) enzyme. Here, we have performed novel experiments to determine the 5hmC level and TET1 protein expression in 43 parathyroid adenomas (PAs) and 17 parathyroid carcinomas (PCs) from patients who had local invasion or metastases and to address a potential growth regulatory role of TET1. Results: The global 5hmC level was determined by a semi-quantitative DNA immune-dot blot assay in a smaller number of tumors. The global 5hmC level was reduced in nine PCs and 15 PAs compared to four normal tissue samples (p < 0.05), and it was most severely reduced in the PCs. By immunohistochemistry, all 17 PCs stained negatively for 5hmC and TET1 showed negative or variably heterogeneous staining for the majority. All 43 PAs displayed positive 5hmC staining, and a similar aberrant staining pattern of 5hmC and TET1 was seen in about half of the PAs. Western blotting analysis of two PCs and nine PAs showed variable TET1 protein expression levels. A significantly higher tumor weight was associated to PAs displaying a more severe aberrant staining pattern of 5hmC and TET1. Overexpression of TET1 in a colony forming assay inhibited parathyroid tumor cell growth. Conclusions: 5hmC can discriminate between PAs and PCs. Whether 5hmC represents a novel marker for malignancy warrants further analysis in additional parathyroid tumor cohorts. The results support a growth regulatory role of TET1 in parathyroid tissue.
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3.
  • Barazeghi, Elham, et al. (författare)
  • A role for TET2 in parathyroid carcinoma
  • 2017
  • Ingår i: Endocrine-Related Cancer. - 1351-0088 .- 1479-6821. ; 24:7, s. 329-338
  • Tidskriftsartikel (refereegranskat)abstract
    • Primary hyperparathyroidism (pHPT) is rarely caused by parathyroid carcinoma (PC, <1-5% of pHPT cases). The TET proteins oxidize the epigenetic mark 5-methylcytosine to 5-hydroxymethylcytosine (5hmC) and inactivation by mutation or epigenetic deregulation of TET1 and TET2 play important roles in various cancers. Recently, we found that 5hmC was severely reduced in all of the analyzed PCs and with deranged expression of TET1 for the majority of PCs. Here, we have examined the expression of the TET2 protein in 15 5hmC-negative PCs from patients who had local invasion or metastases. Cell growth and cell migratory roles for TET2 as well as epigenetic deregulated expression were addressed. Immunohistochemistry revealed very low/undetectable expression of TET2 in all PCs and verified for two PCs that were available for western blotting analysis. Knockdown of TET2 in the parathyroid cell line sHPT-1 resulted in increased cell growth and increased cell migration. DNA sequencing of TET2 in PCs revealed two common variants and no obvious inactivating mutations. Quantitative bisulfite pyrosequencing analysis of the TET2 promoter CpG island revealed higher CpG methylation level in the PCs compared to that in normal tissues and treatment of a PC primary cell culture with the DNA methylation inhibitor 5-aza-2'-deoxycytidine caused increased expression of the methylated TET2 gene. Hence, the data suggest that deregulated expression of TET2 by DNA hypermethylation may contribute to the aberrantly low level of 5hmC in PCs and further that TET2 plays a cell growth and cell migratory regulatory role and may constitute a parathyroid tumor suppressor gene.
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5.
  • Barazeghi, Elham, et al. (författare)
  • Decrease of 5-hydroxymethylcytosine and TET1 with nuclear exclusion of TET2 in small intestinal neuroendocrine tumors.
  • 2018
  • Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407 .- 1471-2407. ; 18:1
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Small intestinal neuroendocrine tumors (SI-NETs) originate from enterochromaffin cells scattered in the intestinal mucosa of the ileum and jejunum. Loss of one copy of chromosome 18 is the most frequent observed aberration in primary tumors and metastases. The aim of this study was to investigate possible involvement of 5-hydroxymethylcytosine (5hmC), TET1 and TET2 in SI-NETs.METHODS: The analysis was conducted using 40 primary tumors and corresponding 47 metastases. The level of 5hmC, TET1 and TET2 was analyzed by DNA immune-dot blot assay and immunohistochemistry. Other methods included a colony forming assay, western blotting analysis, and quantitative bisulfite pyrosequencing analysis. The effect of the exportin-1 nuclear transport machinery inhibitors on cell proliferation and apoptosis was also explored using two SI-NET cell lines.RESULTS: Variable levels of 5hmC and a mosaic staining appearance with a mixture of positive and negative cell nuclei, regardless of cell number and staining strength, was observed overall both in primary tumors and metastases. Similarly aberrant staining pattern was observed for TET1 and TET2. In a number of tumors (15/32) mosaic pattern together with areas of negative staining was also observed for TET1. Abolished expression of TET1 in the tumors did not seem to involve hypermethylation of the TET1 promoter region. Overexpression of TET1 in a colony forming assay supported a function as cell growth regulator. In contrast to 5hmC and TET1, TET2 was also observed in the cytoplasm of all the analyzed SI-NETs regardless of nuclear localization. Treatment of CNDT2.5 and KRJ-I cells with the exportin-1 (XPO1/CRM1) inhibitor, leptomycin B, induced reduction in the cytoplasm and nuclear retention of TET2. Aberrant partitioning of TET2 from the nucleus to the cytoplasm seemed therefore to involve the exportin-1 nuclear transport machinery. Reduced cell proliferation and induction of apoptosis were observed after treatment of CNDT2.5 and KRJ-I cells with leptomycin B or KPT-330 (selinexor).CONCLUSIONS: SI-NETs are epigenetically dysregulated at the level of 5-hydroxymethylcytosine/ TET1/TET2. We suggest that KPT-330/selinexor or future developments should be considered and evaluated for single treatment of patients with SI-NET disease and also in combinations with somatostatin analogues, peptide receptor radiotherapy, or everolimus.
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7.
  • Crona, Joakim, et al. (författare)
  • Multiple and Secondary Hormone Secretion in Patients With Metastatic Pancreatic Neuroendocrine Tumours
  • 2016
  • Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 101:2, s. 445-452
  • Tidskriftsartikel (refereegranskat)abstract
    • CONTEXT:As a group, neuroendocrine tumors (NETs) secrete many different peptide hormones, yet heretofore each NET patient is typically thought to produce at most one hormone that causes a distinct hormonal syndrome. A minority of patients have multiple hormones at diagnosis and may also develop secondary hormone secretion at a later stage.OBJECTIVES:The objectives of the study were to determine the frequency and to describe the impact of multiple and secondary hormone secretion in sporadic gasteroenteropancreatic NET patients.DESIGN, SETTING, AND PARTICIPANTS:This was a retrospective analysis of patients (n = 972) with gasteroenteropancreatic NET treated at Uppsala University Hospital, Uppsala, Sweden. Patients with the secretion of multiple hormones at diagnosis and/or those developing secondary hormone secretion during the disease course were identified and studied in further detail.RESULTS:In pancreatic NETs (PNETs), a total of 19 of 323 patients (6%) had secretion of multiple hormones at diagnosis, and 14 of 323 (4%) had secondary changes during the disease course. These phenomena occurred exclusively in patients with an advanced disease stage, and secondary hormones were detected in a close time span with progressive disease. Patients with secondary insulin hypersecretion had increased morbidity as well as reduced survival (P < .002). In contrast, multiple and secondary hormone secretion was rarely seen in NETs of the small intestine with 0 and 1 of 603 cases, respectively.CONCLUSION:Diversity of PNET hormone secretion either at diagnosis or during the disease course occurred in a minority of patients (9.3%). These phenomena had a major impact on patient outcome both through increased morbidity and mortality. Our results support that patients with metastatic PNETs should be monitored for clinical symptoms of secondary hormone secretion during the disease course.
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8.
  • Crona, Joakim, et al. (författare)
  • Somatic Mutations and Genetic Heterogeneity at the CDKN1B Locus in Small Intestinal Neuroendocrine Tumors
  • 2015
  • Ingår i: Annals of Surgical Oncology. - : Springer Science and Business Media LLC. - 1068-9265 .- 1534-4681. ; 22, s. 1428-1435
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Until recently, the genetic landscape of small intestinal neuroendocrine tumors (SI-NETs) was limited to recurrent copy number alterations, most commonly a loss on chromosome 18. Intertumor heterogeneity with nonconcordant genotype in paired primary and metastatic lesions also is described, further contributing to the difficulty of unraveling the genetic enigma of SI-NETs. A recent study analyzing 55 SI-NET exomes nominated CDKN1B (p27) as a haploinsufficient tumor suppressor gene.METHODS: This study aimed to determine the frequency of CDKN1B inactivation and to investigate genotype-phenotype correlations. It investigated 362 tumors from 200 patients. All samples were resequenced for mutations in CDKN1B using automated Sanger sequencing. The expression of p27 was investigated in 12 CDKN1B mutant and nine wild type tumors.RESULTS: Some 8.5 % (17/200) of patients had tumors with pathogenic mutations in CDKN1B including 13 insertion deletions, four nonsense variants, and one stop-loss variant. All variants with available nontumoral DNA were classified as somatic. Inter- and intratumor heterogeneity at the CDKN1B locus was detected respectively in six of ten and two of ten patients. Patients with CDKN1B mutated tumors had both heterogeneous disease presentation and diverse prognosis. Expression of the p27 protein did not correlate with CDKN1B mutation status, and no differences in the clinical characteristics between CDKN1B mutated and CDKN1B wild type tumor carriers were found.CONCLUSION: This study corroborates the finding of CDKN1B as a potential haplo-insufficient tumor suppressor gene characterized by inter- and intratumor heterogeneity in SI-NETs.
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10.
  • Daskalakis, Kosmas, et al. (författare)
  • Association of a Prophylactic surgical approach to Stage IV Small Intestinal Neuroendocrine Tumors with Survival.
  • 2018
  • Ingår i: JAMA Oncology. - : American Medical Association (AMA). - 2374-2437 .- 2374-2445. ; 4:2, s. 183-189
  • Tidskriftsartikel (refereegranskat)abstract
    • Importance: Primary tumor resection and mesenteric lymph node dissection in asymptomatic patients with stage IV Small Intestinal Neuroendocrine Tumors (SI-NETs) is controversial.Objective:  To determine whether locoregional surgery performed at diagnosis in asymptomatic SI-NETs patients with distant metastases affects overall survival (OS), morbidity and mortality, length of hospital stay (LOS) and re-operation rates.Design: This investigation was a cohort study of asymptomatic patients with stage IV SI-NET, diagnosed between 1985 and 2015, using the prospective Uppsala database of SI-NETs and the Swedish National Patient Register. Patients included were followed until May 2016 and divided to a first group, which underwent Prophylactic Upfront Surgery within six months from diagnosis Combined with Oncological treatment (PUSCO group) and a second group, which was either treated non-surgically or operated later (Delayed Surgery As Needed Combined with Oncological treatment [DSANCO group]).Setting: A tertiary referral center with follow-up data from the Swedish National Patient Register.Participants: We included 363 stage IV SI-NET patients without any abdominal symptoms within 6 months from diagnosis, treated either with PUSCO (n=161) or DSANCO (n=202).Exposure: PUSCO vs DSANCO.Main Outcomes and Measures: Overall survival (OS), length of hospital stay (LOS), postoperative morbidity and mortality and re-operation rates measured from baseline. Propensity score match was performed between the two groups.Results: Two isonumerical groups (n=91) occurred after propensity score matching. There was no difference between groups in OS (PUSCO median 7.9 vs DSANCO 7.6 years; [hazard ratio] HR, 0.98; [95% CI, 0.70-1.37]; log-rank P=.93) and cancer-specific survival (median 7.7 vs 7.6 years, HR, 0.99; [95%CI, 0.71-1.40]; log-rank P=.99). There was no difference in 30-day mortality (0% in both matched groups) or postoperative morbidity (2% vs 1%; P>.99), LOS (median 73 vs 76 days; P=.64), LOS due to local tumor-related symptoms (median 7 vs 11.5 days; P=.81) or incisional hernia repairs (4% in both groups; P>.99).  Patients from the PUSCO group underwent more re-operative procedures (14%) compared to the DSANCO group (3%) due to intestinal obstruction (P< .001).Conclusion: Prophylactic upfront locoregional surgery confers no survival advantage in asymptomatic stage IV SI-NET patients. Delayed surgery as needed seems to be comparable in all examined outcomes, whilst offering the advantage of less re-operations for intestinal obstruction.  The value of a priori locoregional surgery in the presence of distant metastases is challenged and needs to be elucidated in a randomized controlled study. 
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