| 1. |
- Arthur, Cecilia, et al.
(author)
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Patient-Specific Assays Based on Whole-Genome Sequencing Data to Measure Residual Disease in Children With Acute Lymphoblastic Leukemia : A Proof of Concept Study
- 2022
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In: Frontiers in Oncology. - : Frontiers Media S.A.. - 2234-943X. ; 12
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Journal article (peer-reviewed)abstract
- Risk-adapted treatment in acute lymphoblastic leukemia (ALL) relies on genetic information and measurable residual disease (MRD) monitoring. In this proof of concept study, DNA from diagnostic bone marrow (BM) of six children with ALL, without stratifying genetics or central nervous system (CNS) involvement, underwent whole-genome sequencing (WGS) to identify structural variants (SVs) in the leukemic blasts. Unique sequences generated by SVs were targeted with patient-specific droplet digital PCR (ddPCR) assays. Genomic DNA (gDNA) from BM and cell-free DNA (cfDNA) from plasma and cerebrospinal fluid (CSF) were analyzed longitudinally. WGS with 30x coverage enabled target identification in all cases. Limit of quantifiability (LoQ) and limit of detection (LoD) for the ddPCR assays (n = 15) were up to 10(-5) and 10(-6), respectively. All targets were readily detectable in a multiplexed ddPCR with minimal DNA input (1 ng of gDNA) at a 10(-1) dilution, and targets for half of the patients were also detectable at a 10(-2) dilution. The level of MRD in BM at end of induction and end of consolidation block 1 was in a comparable range between ddPCR and clinical routine methods for samples with detectable residual disease, although our approach consistently detected higher MRD values for patients with B-cell precursor ALL. Additionally, several samples with undetectable MRD by flow cytometry were MRD-positive by ddPCR. In plasma, the level of leukemic targets decreased in cfDNA over time following the MRD level detected in BM. cfDNA was successfully extracted from all diagnostic CSF samples (n = 6), and leukemic targets were detected in half of these. The results suggest that our approach to design molecular assays, together with ddPCR quantification, is a technically feasible option for accurate MRD quantification and that cfDNA may contribute valuable information regarding MRD and low-grade CNS involvement.
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| 2. |
- Perland, Emelie, et al.
(author)
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Structural prediction of two novel human atypical SLC transporters, MFSD4A and MFSD9, and their neuroanatomical distribution in mice
- 2017
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:10
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Journal article (peer-reviewed)abstract
- Out of the 430 known solute carriers (SLC) in humans, 30% are still orphan transporters regarding structure, distribution or function. Approximately one third of all SLCs belong to the evolutionary conserved and functionally diverse Major Facilitator Superfamily (MFS). Here, we studied the orphan proteins, MFSD4A and MFSD9, which are atypical SLCs of MFS type. Hidden Markov Models were used to identify orthologues in several vertebrates, and human MFSD4A and MFSD9 share high sequence identity with their identified orthologues. MFSD4A and MFSD9 also shared more than 20% sequence identity with other phylogenetically related SLC and MFSD proteins, allowing new family clustering. Homology models displayed 12 transmembrane segments for both proteins, which were predicted to fold into a transporter-shaped structure. Furthermore, we analysed the location of MFSD4A and MFSD9 in adult mouse brain using immunohistochemistry, showing abundant neuronal protein staining. As MFSD4A and MFSD9 are plausible transporters expressed in food regulatory brain areas, we monitored transcriptional changes in several mouse brain areas after 24 hours food-deprivation and eight weeks of high-fat diet, showing that both genes were affected by altered food intake in vivo. In conclusion, we propose MFSD4A and MFSD9 to be novel transporters, belonging to disparate SLC families. Both proteins were located to neurons in mouse brain, and their mRNA expression levels were affected by the diet.
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| 3. |
- Öfverholm, Ingegerd, et al.
(author)
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The prognostic impact of IKZF1 deletions and UKALL genetic classifiers in paediatric B-cell precursor acute lymphoblastic leukaemia treated according to NOPHO 2008 protocols
- 2023
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In: British Journal of Haematology. - : Wiley-Blackwell. - 0007-1048 .- 1365-2141. ; 202:2, s. 384-392
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Journal article (peer-reviewed)abstract
- We investigated 390 paediatric B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) patients treated according to NOPHO ALL 2008, regarding copy number alterations (CNA) of eight loci associated with adverse prognosis, including IKZF1. The impact on outcome was investigated for each locus individually, combined as CNA profiles and together with cytogenetic information. The presence of IKZF1 deletion or a poor-risk CNA profile was associated with poor outcome in the whole cohort. In the standard-risk group, IKZF1-deleted cases had an inferior probability of relapse-free survival (pRFS) (p <= 0.001) and overall survival (pOS) (p <= 0.001). Additionally, among B-other patients, IKZF1 deletion correlated with poor pRFS (60% vs. 90%) and pOS (65% vs. 89%). Both IKZF1 deletion and a poor-risk CNA profile were independent factors for relapse and death in multivariable analyses adjusting for known risk factors including measurable residual disease. Our data indicate that BCP-ALL patients with high-risk CNA or IKZF1 deletion have worse prognosis despite otherwise low-risk features. Conversely, patients with both a good CNA and cytogenetic profile had a superior relapse-free (p <= 0.001) and overall survival (p <= 0.001) in the cohort, across all risk groups. Taken together, our findings highlight the potential of CNA assessment to refine stratification in ALL.
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