| 1. |
- Bertolotto, Corine, et al.
(författare)
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A SUMOylation-defective MITF germline mutation predisposes to melanoma and renal carcinoma
- 2011
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 480:7375, s. 94-98
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Tidskriftsartikel (refereegranskat)abstract
- So far, no common environmental and/or phenotypic factor has been associated with melanoma and renal cell carcinoma (RCC). The known risk factors for melanoma include sun exposure, pigmentation and nevus phenotypes(1); risk factors associated with RCC include smoking, obesity and hypertension(2). A recent study of coexisting melanoma and RCC in the same patients supports a genetic predisposition underlying the association between these two cancers(3). The microphthalmia-associated transcription factor (MITF) has been proposed to act as a melanoma oncogene(4); it also stimulates the transcription of hypoxia inducible factor(5) (HIF1A), the pathway of which is targeted by kidney cancer susceptibility genes(6). We therefore proposed that MITF might have a role in conferring a genetic predisposition to co-occurring melanoma and RCC. Here we identify a germline missense substitution in MITF (Mi-E318K) that occurred at a significantly higher frequency in genetically enriched patients affected with melanoma, RCC or both cancers, when compared with controls. Overall, Mi-E318K carriers had a higher than fivefold increased risk of developing melanoma, RCC or both cancers. Codon 318 is located in a small-ubiquitin-like modifier (SUMO) consensus site (Psi KXE) and Mi-E318K severely impaired SUMOylation of MITF. Mi-E318K enhanced MITF protein binding to the HIF1A promoter and increased its transcriptional activity compared to wild-type MITF. Further, we observed a global increase in Mi-E318K occupied loci. In an RCC cell line, gene expression profiling identified a Mi-E318K signature related to cell growth, proliferation and inflammation. Lastly, the mutant protein enhanced melanocytic and renal cell clonogenicity, migration and invasion, consistent with a gain-of-function role in tumorigenesis. Our data provide insights into the link between SUMOylation, transcription and cancer.
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| 2. |
- Kim, Hyeongju, et al.
(författare)
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A pathogenic proteolysis-resistant huntingtin isoform induced by an antisense oligonucleotide maintains huntingtin function
- 2022
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Ingår i: JCI Insight. - : American Society for Clinical Investigation. - 2379-3708. ; 7:17
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Tidskriftsartikel (refereegranskat)abstract
- Huntington's disease (HD) is a late-onset neurological disorder for which therapeutics are not available. Its key pathological mechanism involves the proteolysis of polyglutamine-expanded (polyQ-expanded) mutant huntingtin (mHTT), which generates N-terminal fragments containing polyQ, a key contributor to HD pathogenesis. Interestingly, a naturally occurring spliced form of HTT mRNA with truncated exon 12 encodes an HTT (HTT & UDelta;12) with a deletion near the caspase-6 cleavage site. In this study, we used a multidisciplinary approach to characterize the therapeutic potential of targeting HTT exon 12. We show that HTT & UDelta;12 was resistant to caspase-6 cleavage in both cell-free and tissue lysate assays. However, HTT & UDelta;12 retained overall biochemical and structural properties similar to those of wt-HTT. We generated mice in which HTT exon 12 was truncated and found that the canonical exon 12 was dispensable for the main physiological functions of HTT, including embryonic development and intracellular trafficking. Finally, we pharmacologically induced HTT & UDelta;12 using the antisense oligonucleotide (ASO) QRX-704. QRX-704 showed predictable pharmacology and efficient biodistribution. In addition, it was stable for several months and inhibited pathogenic proteolysis. Furthermore, QRX-704 treatments resulted in a reduction of HTT aggregation and an increase in dendritic spine count. Thus, ASO-induced HTT exon 12 splice switching from HTT may provide an alternative therapeutic strategy for HD.
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| 3. |
- Törnquist, Elin, et al.
(författare)
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Dual modality neutron and x-ray tomography for enhanced image analysis of the bone-metal interface
- 2021
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Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 0031-9155 .- 1361-6560. ; 66:13
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Tidskriftsartikel (refereegranskat)abstract
- The bone tissue formed at the contact interface with metallic implants, particularly its 3D microstructure, plays a pivotal role for the structural integrity of implant fixation. X-ray tomography is the classical imaging technique used for accessing microstructural information from bone tissue. However, neutron tomography has shown promise for visualising the immediate bone-metal implant interface, something which is highly challenging with x-rays due to large differences in attenuation between metal and biological tissue causing image artefacts. To highlight and explore the complementary nature of neutron and x-ray tomography, proximal rat tibiae with titanium-based implants were imaged with both modalities. The two techniques were compared in terms of visualisation of different material phases and by comparing the properties of the individual images, such as the contrast-to-noise ratio. After superimposing the images using a dedicated image registration algorithm, the complementarity was further investigated via analysis of the dual modality histogram, joining the neutron and x-ray data. From these joint histograms, peaks with well-defined grey value intervals corresponding to the different material phases observed in the specimens were identified and compared. The results highlight differences in how neutrons and x-rays interact with biological tissues and metallic implants, as well as the benefits of combining both modalities. Future refinement of the joint histogram analysis could improve the segmentation of structures and tissues, and yield novel information about specimen-specific properties such as moisture content.
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| 4. |
- Vermeiren, Angelique P. A., et al.
(författare)
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The Association Between APOE epsilon 4 and Alzheimer-type Dementia Among Memory Clinic Patients is Confined to those with a Higher Education. The DESCRIPA Study
- 2013
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 35:2, s. 241-246
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Tidskriftsartikel (refereegranskat)abstract
- We assessed the interaction between the APOE epsilon 4 allele and education level in the etiology of Alzheimer's disease (AD) among memory clinic patients from the multicenter DESCRIPA study. Subjects (n = 544) were followed for 1 to 5 years. We used Cox's stratified survival modeling, adjusted for age, gender, and center. APOE epsilon 4 predicted the onset of AD-type dementia in middle (HR 3.45 95% CI 1.79-6.65, n = 222) and high (HR 3.67 95% CI 1.36-9.89, n = 139) but not in low educated subjects (HR 0.81, 95% CI 0.38-1.72, n = 183). This suggests that mechanisms in developing Alzheimer-type dementia may differ between educational groups that raises questions related to Alzheimer-type dementia prevention.
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