| 1. |
- Näslund, Olivia, et al.
(författare)
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Indications and outcome in surgically treated asymptomatic meningiomas: a single-center case-control study.
- 2020
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Ingår i: Acta neurochirurgica. - : Springer Science and Business Media LLC. - 0942-0940 .- 0001-6268. ; 162:9, s. 2155-63
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Tidskriftsartikel (refereegranskat)abstract
- Many meningiomas are detected incidentally and remain asymptomatic until intervention. The goal of this study was to describe the management and outcome in this group of surgically treated asymptomatic meningiomas.From 2004 to 2017, 45 patients with asymptomatic meningioma were surgically treated at Sahlgrenska University Hospital, and their medical records and imaging data were analyzed. The asymptomatic cases were matched with symptomatic ones with respect to age at diagnosis, location, WHO (World Health Organization) grade, and Simpson grade.Time from diagnosis to surgery differed between the asymptomatic and symptomatic patients (8.6 vs. 1.3months; p<0.001). Of symptomatic patients, 32.6% still used anti-epileptic drugs >1year after surgery, compared with 7.7% of the asymptomatic (p=0.003). Thirty-day complication rate was significantly higher among the asymptomatic cases (35.6% vs. 24.4%; 0.001), as well as the proportion of older asymptomatic individuals (>70years) experiencing postoperative complication compared with symptomatic patients of the same age group.As expected, asymptomatic cases had smaller tumors and waited longer for surgery. Surprisingly, complication rate was significantly higher among asymptomatic cases compared with their symptomatic control. Taken into account that many asymptomatic tumors are removed surgically due to patient's wish, one might suggest a more restrictive approach, especially in the elderly.
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| 2. |
- Bergström, Petra, et al.
(författare)
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Amyloid precursor protein expression and processing are differentially regulated during cortical neuron differentiation
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid precursor protein (APP) and its cleavage product amyloid beta (A beta) have been thoroughly studied in Alzheimer's disease. However, APP also appears to be important for neuronal development. Differentiation of induced pluripotent stem cells (iPSCs) towards cortical neurons enables in vitro mechanistic studies on human neuronal development. Here, we investigated expression and proteolytic processing of APP during differentiation of human iPSCs towards cortical neurons over a 100-day period. APP expression remained stable during neuronal differentiation, whereas APP processing changed. alpha-Cleaved soluble APP (sAPP alpha) was secreted early during differentiation, from neuronal progenitors, while beta-cleaved soluble APP (sAPP beta) was first secreted after deep-layer neurons had formed. Short A beta peptides, including A beta 1-15/16, peaked during the progenitor stage, while processing shifted towards longer peptides, such as A beta 1-40/42, when post-mitotic neurons appeared. This indicates that APP processing is regulated throughout differentiation of cortical neurons and that amyloidogenic APP processing, as reflected by A beta 1-40/42, is associated with mature neuronal phenotypes.
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| 3. |
- Bontell, Thomas Olsson
(författare)
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lmproving diagnosis of central nervous system tumours using genetic and epigenetic tools
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Brain tumor diagnostics has traditionally been based on histopathology stains. The introduction of immunohistochemistry stains resulted in improved ability to classify these often devastating tumors. The understanding of molecular markers in central nervous system tumors has improved substantially in recent decades. Demonstration of specific genetic changes such as mutations can have crucial impact on selection of therapy. Genetic changes also play an increasingly important role when it comes to classification of these tumors. Correct classification and grading are important to be able to give correct prognostic and predictive information and are of fundamental importance for efficient clinical patient handling. In this thesis, we use several molecular techniques to improve tumor diagnosis and tumor classification and investigate the utility of these methods to give a deeper understanding of these neoplastic processes. In Paper I, we investigated the DNA methylation profiling method for molecular classification of diffuse lower grade gliomas. We showed that DNA methylation profiling not only gave correct diagnostic and prognostic information but also were able to give reliable molecular information enabling molecular classification of the tumors according to the World Health Organization classification system. In Paper II, we assessed changes in DNA methylation pattern over time in diffuse IDH-mutant gliomas. We showed that tumors accumulated methylation alterations during progression, but that the overall methylation patterns most often were maintained upon recurrence. In Paper III, we explored if a proposed immunohistochemistry-based investigation of phenotype predicted survival and tumor recurrence in a clinical cohort of diffuse low-grade gliomas that were reclassified according to the 2021 WHO criteria. In Paper IV, we describe a 16-month-old patient with a tumor in the third ventricle with a relapse two years after diagnosis. The tumor was initially classified as a low-grade glioma but was after methylation profiling reclassified as an infant-type hemispheric glioma. To search for druggable targets and for further refinement of the molecular background both whole genome sequencing and whole transcriptome sequencing were performed. A novel TPR::ROS1 fusion gene was detected activating the MAPK-, PI3K- and JAK/STAT- pathways. In Paper V, we present a cystic pilocytic astrocytoma with KIAA1549::BRAF fusion in a 16-year-old patient. The tumor showed ganglion cell morphology and different vascularization in a nodular component. With extended molecular examination we were able to prove that the cells with ganglion cell morphology were of neoplastic origin. In conclusion, we further demonstrate the importance of adding molecular investigation in the histopathological diagnostic work-up. We also present arguments for the importance of evaluating molecular findings in correlation with the histomorphology picture.
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| 4. |
- Carstam, Louise, et al.
(författare)
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WHO Grade Loses Its Prognostic Value in Molecularly Defined Diffuse Lower-Grade Gliomas.
- 2021
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Ingår i: Frontiers in Oncology. - : Frontiers Media S.A.. - 2234-943X. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background: While molecular insights to diffuse lower-grade glioma (dLGG) have improved the basis for prognostication, most established clinical prognostic factors come from the pre-molecular era. For instance, WHO grade as a predictor for survival in dLGG with isocitrate dehydrogenase (IDH) mutation has recently been questioned. We studied the prognostic role of WHO grade in molecularly defined subgroups and evaluated earlier used prognostic factors in the current molecular setting.Material and Methods: A total of 253 adults with morphological dLGG, consecutively included between 2007 and 2018, were assessed. IDH mutations, codeletion of chromosomal arms 1p/19q, and cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) deletions were analyzed.Results: There was no survival benefit for patients with WHO grade 2 over grade 3 IDH-mut dLGG after exclusion of tumors with known CDKN2A/B homozygous deletion (n=157) (log-rank p=0.97). This was true also after stratification for oncological postoperative treatment and when astrocytomas and oligodendrogliomas were analyzed separately. In IDH-mut astrocytomas, residual tumor volume after surgery was an independent prognostic factor for survival (HR 1.02; 95% CI 1.01-1.03; p=0.003), but not in oligodendrogliomas (HR 1.02; 95% CI 1.00-1.03; p=0.15). Preoperative tumor size was an independent predictor in both astrocytomas (HR 1.03; 95% CI 1.00-1.05; p=0.02) and oligodendrogliomas (HR 1.05; 95% CI 1.01-1.09; p=0.01). Age was not a significant prognostic factor in multivariable analyses (astrocytomas p=0.64, oligodendrogliomas p=0.08).Conclusion: Our findings suggest that WHO grade is not a robust prognostic factor in molecularly well-defined dLGG. Preoperative tumor size remained a prognostic factor in both IDH-mut astrocytomas and oligodendrogliomas in our cohort, whereas residual tumor volume predicted prognosis in IDH-mut astrocytomas only. The age cutoffs for determining high risk in patients with IDH-mut dLGG from the pre-molecular era are not supported by our results.
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| 5. |
- Corell, Alba, et al.
(författare)
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Stemness and clinical features in relation to the subventricular zone in diffuse lower-grade glioma : an exploratory study
- 2022
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Ingår i: Neuro-Oncology Advances. - : Oxford University Press. - 2632-2498. ; 4:1
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Tidskriftsartikel (refereegranskat)abstract
- Background The subventricular zone (SVZ) of the human brain is a site of adult stem cell proliferation and a microenvironment for neural stem cells (NSCs). It has been suggested that NSCs in the SVZ are potential cells of origin containing driver mutations of glioblastoma, but their role in the origin of diffuse lower-grade gliomas (dLGGs) is not much studied. Methods We included 188 patients >= 18 years with IDH-mutated dLGG (WHO grades 2-3) histologically diagnosed between 2007 and 2020. Tissue microarrays of tumor samples for patients between 2007 and 2016 were used for immunodetection of Nestin, SOX2, SOX9, KLF4, NANOG, CD133 cMYC, and Ki67. DNA methylation profile was used for stemness index (mDNAsi). Tumor contact with the SVZ was assessed and the distance was computed. Results Overall, 70.2% of the dLGG had SVZ contact. Tumors with SVZ contact were larger (102.4 vs 30.9 mL, P < .01), the patients were older (44.3 vs 40.4 years, P = .04) and more often had symptoms related to increased intracranial pressure (31.8% vs 7.1%, P < .01). The expression of SOX2, SOX9, Nestin, and Ki67 showed intersample variability, but no difference was found between tumors with or without SVZ contact, nor with the actual distance to the SVZ. mDNAsi was similar between groups (P = .42). Conclusions We found no statistical relationship between proximity with the SVZ and mDNAsi or expression of SOX2, SOX9, Nestin, and Ki67 in IDH-mutated dLGG. Our data suggest that the potential impact of SVZ on IDH-mutated dLGG is probably not associated with a more stemness-like tumor profile.
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| 6. |
- Corell, Alba, et al.
(författare)
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The clinical significance of the T2-FLAIR mismatch sign in grade II and III gliomas: a population-based study.
- 2020
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Ingår i: BMC cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- The T2-FLAIR mismatch sign is an imaging finding highly suggestive of isocitrate dehydrogenase mutated (IDH-mut) 1p19q non-codeleted (non-codel) gliomas (astrocytomas). In previous studies, it has shown excellent specificity but limited sensitivity for IDH-mut astrocytomas. Whether the mismatch sign is a marker of a clinically relevant subtype of IDH-mut astrocytomas is unknown.We included histopathologically verified supratentorial lower-grade gliomas (LGG) WHO grade II-III retrospectively during the period 2010-2016. In the period 2017-2018, patients with suspected LGG radiologically were prospectively included, and in this cohort other diagnoses than glioma could occur. Clinical, radiological and molecular data were collected. For clinical evaluation we included all patients with IDH-mut astrocytomas. In the 2010-2016 cohort DNA methylation analysis with Infinium MethylationEPIC BeadChip (Illumina) was performed for patients withan IDH-mut astrocytomawith available tissue. We aimed to examine the association of the T2-FLAIRmismatch sign with clinical factors and outcomes. Additionally, we evaluated the diagnostic reliability of the mismatch sign and its relation to methylation profiles.Out of 215 patients with LGG, 135 had known IDH-mutation and 1p19q codeletion status. Fifty patients hadan IDH-mut astrocytoma and 12 of these (24.0%) showed a mismatch sign. The sensitivity and specificity of the mismatch sign for IDH-mut detection were 26.4 and 97.6%, respectively. There were no differences between patients withan IDH-mut astrocytoma with or without mismatch sign when grouped according to T2-FLAIR mismatch sign with respect to baseline characteristics, clinical outcomes and methylation profiles. The overall interrater agreement between neuroradiologist and clinical neurosurgeons for the T2-FLAIR mismatch sign was significant when all 215 MRI examination assessed (κ=0.77, p<0.001, N=215).The T2-FLAIR mismatch sign in patients withan IDH-mut astrocytoma is not associated with clinical presentation or outcome. It seems unlikely that the IDH-mut astrocytomas with mismatch sign represent a specific subentity. Finally, we have validated that the T2-FLAIR mismatch sign is a reliable and specific marker of IDH-mut astrocytomas.
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| 7. |
- Deland, Lily, et al.
(författare)
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Discovery of a rare GKAP1-NTRK2 fusion in a pediatric low-grade glioma, leading to targeted treatment with TRK-inhibitor larotrectinib
- 2021
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Ingår i: Cancer Biology & Therapy. - : Taylor & Francis. - 1538-4047 .- 1555-8576. ; 22:3, s. 184-195
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Tidskriftsartikel (refereegranskat)abstract
- Here we report a case of an 11-year-old girl with an inoperable tumor in the optic chiasm/hypothalamus, who experienced several tumor progressions despite three lines of chemotherapy treatment. Routine clinical examination classified the tumor as a BRAF-negative pilocytic astrocytoma. Copy-number variation profiling of fresh frozen tumor material identified two duplications in 9q21.32–33 leading to breakpoints within the GKAP1 and NTRK2 genes. RT-PCR Sanger sequencing revealed a GKAP1-NTRK2 exon 10–16 in-frame fusion, generating a putative fusion protein of 658 amino acids with a retained tyrosine kinase (TK) domain. Functional analysis by transient transfection of HEK293 cells showed the GKAP1-NTRK2 fusion protein to be activated through phosphorylation of the TK domain (Tyr705). Subsequently, downstream mediators of the MAPK- and PI3K-signaling pathways were upregulated in GKAP1-NTRK2 cells compared to NTRK2 wild-type; phosphorylated (p)ERK (3.6-fold), pAKT (1.8- fold), and pS6 ribosomal protein (1.4-fold). Following these findings, the patient was enrolled in a clinical trial and treated with the specific TRK-inhibitor larotrectinib, resulting in the arrest of tumor growth. The patient’s condition is currently stable and the quality of life has improved significantly. Our findings highlight the value of comprehensive clinical molecular screening of BRAF-negative pediatric low-grade gliomas, to reveal rare fusions serving as targets for precision therapy.
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| 8. |
- Deland, Lily, et al.
(författare)
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Novel TPR::ROS1 Fusion Gene Activates MAPK, PI3K and JAK/STAT Signaling in an Infant-type Pediatric Glioma.
- 2022
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Ingår i: Cancer genomics & proteomics. - : Anticancer Research USA Inc.. - 1109-6535 .- 1790-6245. ; 19:6, s. 711-726
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Tidskriftsartikel (refereegranskat)abstract
- Although fusion genes involving the proto-oncogene receptor tyrosine kinase ROS1 are rare in pediatric glioma, targeted therapies with small inhibitors are increasingly being approved for histology-agnostic fusion-positive solid tumors.Here, we present a 16-month-old boy, with a brain tumor in the third ventricle. The patient underwent complete resection but relapsed two years after diagnosis and underwent a second operation. The tumor was initially classified as a low-grade glioma (WHO grade 2); however, methylation profiling suggested the newly WHO-recognized type: infant-type hemispheric glioma. To further refine the molecular background, and search for druggable targets, whole genome (WGS) and whole transcriptome (RNA-Seq) sequencing was performed.Concomitant WGS and RNA-Seq analysis revealed several segmental gains and losses resulting in complex structural rearrangements and fusion genes. Among the top-candidates was a novel TPR::ROS1 fusion, for which only the 3' end of ROS1 was expressed in tumor tissue, indicating that wild type ROS1 is not normally expressed in the tissue of origin. Functional analysis by Western blot on protein lysates from transiently transfected HEK293 cells showed the TPR::ROS1 fusion gene to activate the MAPK-, PI3K- and JAK/STAT- pathways through increased phosphorylation of ERK, AKT, STAT and S6. The downstream pathway activation was also confirmed by immunohistochemistry on tumor tissue slides from the patient.We have mapped the activated oncogenic pathways of a novel ROS1-fusion gene and broadened the knowledge of the newly recognized infant-type glioma subtype. The finding facilitates suitable targeted therapies for the patient in case of relapse.
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| 9. |
- Fekete, Boglarka, et al.
(författare)
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The Gothenburg population-based glioblastoma research database: Methodological aspects and potential impact
- 2019
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Ingår i: Neurology and Neurosurgery. - 2631-4339. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Background: Glioblastoma Multiforme (GBM) is the most frequently encountered malignant primary brain tumour. Population-based studies of GBM are still scarce. The current paper describes the design of a prospective population-based multidisciplinary research effort on GBM. Objective: To address the impact of a wide range of clinical parameters in relation to clinical outcome and survival in a population-based cohort of patients with GBM. Further, we aim to examine the role of established and novel biomarkers in tumour tissue and blood in relation to response to treatment and clinical outcome. Methods: This is a single institution, population-based study with consecutive inclusion of patients based on a presumed diagnosis of GBM following radiological diagnostic work-up and discussion at a multidisciplinary tumour conference. Clinical parameters and treatment-related parameters at disease onset and during follow-up, and survival will be recorded. Health-related quality of life and emotional wellbeing for patients and their relatives will be assessed. Fresh-frozen and formalin-fixed paraffin-embedded (FFPE) tumour tissue is stored in an associated tissue biobank. Tissue micro-arrays are generated from representative areas of FFPE. Blood samples at admission for surgery and during follow-up are taken and stored frozen. Expected outcome: The study offers a multidisciplinary and translational approach to GBM research by linking a wide range of clinical parameters to biological parameters with high external validity. Thus, we expect to describe patterns of care and clinical course in a well-defined population-based cohort. Through a biomarker approach, we expect to 1) identify new biological subgroups of GBM, 2) explore and validate established and novel biomarkers for response to therapy, 3) estimate the proportion of patients suitable for targeted (“druggable”) therapy, and 4) explore and validate established and novel biomarkers for survival.
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| 10. |
- Ferreyra Vega, Sandra, et al.
(författare)
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DNA methylation profiling for molecular classification of adult diffuse lower-grade gliomas.
- 2021
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Ingår i: Clinical Epigenetics. - : Springer Nature. - 1868-7083 .- 1868-7075. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: DNA methylation profiling has facilitated and improved the classification of a wide variety of tumors of the central nervous system. In this study, we investigated the potential utility of DNA methylation profiling to achieve molecular diagnosis in adult primary diffuse lower-grade glioma (dLGG) according to WHO 2016 classification system. We also evaluated whether methylation profiling could provide improved molecular characterization and identify prognostic differences beyond the classical histological WHO grade together with IDH mutation status and 1p/19q codeletion status. All patients diagnosed with dLGG in the period 2007-2016 from the Västra Götaland region in Sweden were assessed for inclusion in the study.RESULTS: A total of 166 dLGG cases were subjected for genome-wide DNA methylation analysis. Of these, 126 (76%) were assigned a defined diagnostic methylation class with a class prediction score ≥ 0.84 and subclass score ≥ 0.50. The assigned methylation classes were highly associated with their IDH mutation status and 1p/19q codeletion status. IDH-wildtype gliomas were further divided into subgroups with distinct molecular features.CONCLUSION: The stratification of the patients by methylation profiling was as effective as the integrated WHO 2016 molecular reclassification at predicting the clinical outcome of the patients. Our study shows that DNA methylation profiling is a reliable and robust approach for the classification of dLGG into molecular defined subgroups, providing accurate detection of molecular markers according to WHO 2016 classification.
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