| 1. |
- Agathangelidis, Andreas, et al.
(författare)
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Stereotyped B-cell receptors in one-third of chronic lymphocytic leukemia : a molecular classification with implications for targeted therapies
- 2012
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 119:19, s. 4467-4475
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Tidskriftsartikel (refereegranskat)abstract
- Mounting evidence indicates that grouping of chronic lymphocytic leukemia (CLL) into distinct subsets with stereotyped BCRs is functionally and prognostically relevant. However, several issues need revisiting, including the criteria for identification of BCR stereotypy and its actual frequency as well as the identification of "CLL-biased" features in BCR Ig stereotypes. To this end, we examined 7596 Ig VH (IGHV-IGHD-IGHJ) sequences from 7424 CLL patients, 3 times the size of the largest published series, with an updated version of our purpose-built clustering algorithm. We document that CLL may be subdivided into 2 distinct categories: one with stereotyped and the other with nonstereotyped BCRs, at an approximate ratio of 1: 2, and provide evidence suggesting a different ontogeny for these 2 categories. We also show that subset-defining sequence patterns in CLL differ from those underlying BCR stereotypy in other B-cell malignancies. Notably, 19 major subsets contained from 20 to 213 sequences each, collectively accounting for 943 sequences or one-eighth of the cohort. Hence, this compartmentalized examination of VH sequences may pave the way toward a molecular classification of CLL with implications for targeted therapeutic interventions, applicable to a significant number of patients assigned to the same subset.
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| 2. |
- Bessa, Agustina, et al.
(författare)
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Designing a Pragmatic Intervention to Help Improve the Bladder Cancer Patient Experience
- 2021
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Ingår i: Inquiry. - : Sage Publications. - 0046-9580 .- 1945-7243. ; 58
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Tidskriftsartikel (refereegranskat)abstract
- Bladder cancer (BC) is the 10th most common malignancy worldwide and the patient experience is found to be worse than that for patients diagnosed with other cancer types. We aimed to develop a wellbeing intervention to help improve the bladder cancer patient experience by ameliorating their health-related Quality of Life (HRQoL). We followed the 3 phases of the modified Medical Research Council (MRC) Framework for development of complex interventions. Following a systematic review of the literature on mental, sexual, and physical wellbeing, we conducted discussion groups with patients and healthcare professionals on these 3 themes. A consultation phase was then conducted with all relevant stakeholders to co-design a wellbeing intervention as part of a feasibility study. A pragmatic wellbeing feasibility trial was designed based on the hypothesis that a wellbeing program will increase patient awareness and attendance to services available to them and will better support their needs to improve HRQoL. The primary feasibility endpoints are patient attendance to the services offered and changes in HRQoL. The principle of patient centered care has strengthened the commitment to provide a holistic approach to support BC patients. In this study, we developed a wellbeing intervention in collaboration with patients and healthcare professionals to meet an unmet need in terms of the BC patient experience.
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| 3. |
- Cahill, Nicola, et al.
(författare)
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450K-array analysis of chronic lymphocytic leukemia cells reveals global DNA methylation to be relatively stable over time and similar in resting and proliferative compartments
- 2013
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Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 27:1, s. 150-158
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Tidskriftsartikel (refereegranskat)abstract
- In chronic lymphocytic leukemia (CLL), the microenvironment influences gene expression patterns; however, knowledge is limited regarding the extent to which methylation changes with time and exposure to specific microenvironments. Using high-resolution 450K arrays, we provide the most comprehensive DNA methylation study of CLL to date, analyzing paired diagnostic/follow-up samples from IGHV-mutated/untreated and IGHV-unmutated/treated patients (n = 36) and patient-matched peripheral blood and lymph node samples (n = 20). On an unprecedented scale, we revealed 2239 differentially methylated CpG sites between IGHV-mutated and unmutated patients, with the majority of sites positioned outside annotated CpG islands. Intriguingly, CLL prognostic genes (for example, CLLU1, LPL, ZAP70 and NOTCH1), epigenetic regulator (for example, HDAC9, HDAC4 and DNMT3B), B-cell signaling (for example, IBTK) and numerous TGF-beta and NF-kappa B/TNF pathway genes were alternatively methylated between subgroups. Contrary, DNA methylation over time was deemed rather stable with few recurrent changes noted within subgroups. Although a larger number of non-recurrent changes were identified among IGHV-unmutated relative to mutated cases over time, these equated to a low global change. Similarly, few changes were identified between compartment cases. Altogether, we reveal CLL subgroups to display unique methylation profiles and unveil methylation as relatively stable over time and similar within different CLL compartments, implying aberrant methylation as an early leukemogenic event. Leukemia (2013) 27, 150-158; doi:10.1038/leu.2012.245
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| 4. |
- Cahill, Nicola, 1983-, et al.
(författare)
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IGHV3-21 Gene Frequency in a Swedish Cohort of Patients With Newly Diagnosed Chronic Lymphocytic Leukemia
- 2012
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Ingår i: Clinical Lymphoma, Myeloma & Leukemia. - : Elsevier BV. - 2152-2650 .- 2152-2669. ; 12:3, s. 201-206
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Tidskriftsartikel (refereegranskat)abstract
- The IGHV3-21 gene has been shown to be overrepresented in Scandinavian patients with chronic lymphocytic leukemia (CLL). By investigating a population-based cohort of 337 Swedish patients with CLL, a lower (6.5%) IGHV3-21 frequency was determined relative to our previous hospital-based studies (10.1%-12.7%), yet this frequency remained higher compared to other Western CLL cohorts (2.6%-4.1%). Furthermore, we confirmed the poor outcome for patients with IGHV3-21 to be independent of mutational and stereotypy status. Background: Scandinavian patients with CLL have shown an overrepresentation of the poor-prognostic IGHV3-21 gene. Furthermore, approximately 50% of patients with IGHV3-21 carry stereotyped B-cell receptors, which implicate antigen selection in leukemogenesis. These patients have also been reported to have shorter time to progression than patients with nonstereotyped IGHV3-21. Materials and Methods: To investigate the IGHV3-21 frequency and the clinical impact of IGHV3-21 stereotypy, 337 newly diagnosed Swedish CLL patients from a population-based cohort were analyzed. Results: Interestingly, the IGHV3-21 frequency was indeed lower (6.5%) in this indolent patient cohort than in our previous hospital-based cohort studies (10.1%-12.7%). Hence, a selection bias of more-aggressive cases rendered a higher proportion of IGHV3-21 cases in our original studies. Nevertheless, the Swedish IGHV3-21 frequency still remained higher when compared with other larger European or American studies (2.6%-4.1%). Finally, we confirmed the poor outcome for IGHV3-21 patients to be independent of mutational status and found stereotypy to have no impact on survival or time to treatment. Conclusion: The Swedish geographic bias in IGHV3-21 gene frequency was validated albeit at a lower frequency than previously reported. Moreover, no prognostic value could be attributed to IGHV3-21 stereotype status.
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| 5. |
- Cahill, Nicola, et al.
(författare)
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Uncovering the DNA methylome in chronic lymphocytic leukemia
- 2013
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Ingår i: Epigenetics. - : Informa UK Limited. - 1559-2294 .- 1559-2308. ; 8:2, s. 138-148
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Forskningsöversikt (refereegranskat)abstract
- Over the past two decades, aberrant DNA methylation has emerged as a key player in the pathogenesis of chronic lymphocytic leukemia (CLL), and knowledge regarding its biological and clinical consequences in this disease has evolved rapidly. Since the initial studies relating DNA hypomethylation to genomic instability in CLL, a plethora of reports have followed showing the impact of DNA hypermethylation in silencing vital single gene promoters and the reversible nature of DNA methylation through inhibitor drugs. With the recognition that DNA hypermethylation events could potentially act as novel prognostic and treatment targets in CLL, the search for aberrantly methylated genes, gene families and pathways has ensued. Subsequently, the advent of microarray and next-generation sequencing technologies has supported the hunt for such targets, allowing exploration of the methylation landscape in CLL at an unprecedented scale. In light of these analyses, we now understand that different CLL prognostic subgroups are characterized by differential methylation profiles; we recognize DNA methylation of a number of signaling pathways genes to be altered in CLL, and acknowledge the role of DNA methylation outside of traditional CpG island promoters as fundamental players in the regulation of gene expression. Today, the significance and timing of altered DNA methylation within the complex epigenetic network of concomitant epigenetic messengers such as histones and miRNAs is an intensive area of research. In CLL, it appears that DNA methylation is a rather stable epigenetic mark occurring rather early in the disease pathogenesis. However, other consequences, such as how and why aberrant methylation marks occur, are less explored. In this review, we will not only provide a comprehensive summary of the current literature within the epigenetics field of CLL, but also highlight some of the novel findings relating to when, where, why and how altered DNA methylation materializes in CLL.
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| 6. |
- Cavelier, Lucia, et al.
(författare)
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Clonal distribution of BCR-ABL1 mutations and splice isoforms by single-molecule long-read RNA sequencing
- 2015
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Background: The evolution of mutations in the BCR-ABL1 fusion gene transcript renders CML patients resistant to tyrosine kinase inhibitor (TKI) based therapy. Thus screening for BCR-ABL1 mutations is recommended particularly in patients experiencing poor response to treatment. Herein we describe a novel approach for the detection and surveillance of BCR-ABL1 mutations in CML patients. Methods: To detect mutations in the BCR-ABL1 transcript we developed an assay based on the Pacific Biosciences (PacBio) sequencing technology, which allows for single-molecule long-read sequencing of BCR-ABL1 fusion transcript molecules. Samples from six patients with poor response to therapy were analyzed both at diagnosis and follow-up. cDNA was generated from total RNA and a 1,6 kb fragment encompassing the BCR-ABL1 transcript was amplified using long range PCR. To estimate the sensitivity of the assay, a serial dilution experiment was performed. Results: Over 10,000 full-length BCR-ABL1 sequences were obtained for all samples studied. Through the serial dilution analysis, mutations in CML patient samples could be detected down to a level of at least 1%. Notably, the assay was determined to be sufficiently sensitive even in patients harboring a low abundance of BCR-ABL1 levels. The PacBio sequencing successfully identified all mutations seen by standard methods. Importantly, we identified several mutations that escaped detection by the clinical routine analysis. Resistance mutations were found in all but one of the patients. Due to the long reads afforded by PacBio sequencing, compound mutations present in the same molecule were readily distinguished from independent alterations arising in different molecules. Moreover, several transcript isoforms of the BCR-ABL1 transcript were identified in two of the CML patients. Finally, our assay allowed for a quick turn around time allowing samples to be reported upon within 2 days. Conclusions: In summary the PacBio sequencing assay can be applied to detect BCR-ABL1 resistance mutations in both diagnostic and follow-up CML patient samples using a simple protocol applicable to routine diagnosis. The method besides its sensitivity, gives a complete view of the clonal distribution of mutations, which is of importance when making therapy decisions.
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| 7. |
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| 8. |
- Engvall, Marie, et al.
(författare)
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Detection of leukemia gene fusions by targeted RNA-sequencing in routine diagnostics
- 2020
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Ingår i: BMC Medical Genomics. - : BMC. - 1755-8794. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Background We have evaluated an NGS-based method to detect recurrent gene fusions of diagnostic and prognostic importance in hematological malignancies. Our goal was to achieve a highly specific assay with a simple workflow, short turnaround time and low cost. Method The assay uses a commercially available anchored multiplex PCR panel for target enrichment and library preparation, followed by sequencing using a MiSeq instrument. The panel includes all recurrent gene fusions in AML and ALL and is designed to detect gene-specific fusions without prior knowledge of the partner sequence or specific break points. Diagnostic RNA samples from 27 cases with hematological malignancies encompassing 23 different transcript variants were analyzed. In addition, 12 cases from a validation cohort were assessed. Result All known fusion transcripts were identified with a high degree of confidence, with a large number of reads covering the breakpoints. Importantly, we could identify gene fusions where conventional methods had failed due to cryptic rearrangements or rare fusion partners. The newly-identified fusion partners were verified by RT-PCR and transcript-specific qPCR was designed for patient-specific follow-up. In addition, 12 cases were correctly assessed in a blind test, without prior knowledge of molecular cytogenetics or diagnosis. Conclusion In summary, our results demonstrate that targeted RNA sequencing using anchored multiplex PCR can be implemented in a clinical laboratory for the detection of recurrent and rare gene fusions in hematological diagnostic samples.
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| 9. |
- Gudmundsson, Sanna, et al.
(författare)
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Revertant mosaicism repairs skin lesions in a patient with keratitis-ichthyosis-deafness syndrome by second-site mutations in connexin 26
- 2017
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Ingår i: Human Molecular Genetics. - : OXFORD UNIV PRESS. - 0964-6906 .- 1460-2083. ; 26:6, s. 1070-1077
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Tidskriftsartikel (refereegranskat)abstract
- Revertant mosaicism(RM) is a naturally occurring phenomenon where the pathogenic effect of a germline mutation is corrected by a second somatic event. Development of healthy-looking skin due to RM has been observed in patients with various inherited skin disorders, but not in connexin-related disease. We aimed to clarify the underlying molecular mechanisms of suspected RM in the skin of a patient with keratitis-ichthyosis-deafness (KID) syndrome. The patient was diagnosed with KID syndrome due to characteristic skin lesions, hearing deficiency and keratitis. Investigation of GJB2 encoding connexin (Cx) 26 revealed heterozygosity for the recurrent de novo germline mutation, c. 148G>A, p. Asp50Asn. At age 20, the patient developed spots of healthy-looking skin that grew in size and number within widespread erythrokeratodermic lesions. Ultradeep sequencing of two healthy-looking skin biopsies identified five somatic nonsynonymous mutations, independently present in cis with the p. Asp50Asn mutation. Functional studies of Cx26 in HeLa cells revealed co-expression of Cx26-Asp50Asn and wild-type Cx26 in gap junction channel plaques. However, Cx26-Asp50Asn with the second-site mutations identified in the patient displayed no formation of gap junction channel plaques. We argue that the second-site mutations independently inhibit Cx26-Asp50Asn expression in gap junction channels, reverting the dominant negative effect of the p. Asp50Asn mutation. To our knowledge, this is the first time RM has been reported to result in the development of healthy-looking skin in a patient with KID syndrome.
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| 10. |
- Gunnarsson, Rebeqa, et al.
(författare)
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Array-based genomic screening at diagnosis and during follow-up in chronic lymphocytic leukemia
- 2011
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 1592-8721 .- 0390-6078. ; 96:8, s. 1161-1169
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Tidskriftsartikel (refereegranskat)abstract
- Background High-resolution genomic microarrays enable simultaneous detection of copy-number aberrations such as the known recurrent aberrations in chronic lymphocytic leukemia [del(11q), del(13q), del(17p) and trisomy 12], and copy-number neutral loss of heterozygosity. Moreover, comparison of genomic profiles from sequential patients' samples allows detection of clonal evolution. Design and Methods We screened samples from 369 patients with newly diagnosed chronic lymphocytic leukemia from a population-based cohort using 250K single nucleotide polymorphism-arrays. Clonal evolution was evaluated in 59 follow-up samples obtained after 5-9 years. Results At diagnosis, copy-number aberrations were identified in 90% of patients; 70% carried known recurrent alterations, including del(13q) (55%), trisomy 12 (10.5%), del(11q) (10%), and del(17p) (4%). Additional recurrent aberrations were detected on chromosomes 2 (1.9%), 4 (1.4%), 8 (1.6%) and 14 (1.6%). Thirteen patients (3.5%) displayed recurrent copy-number neutral loss of heterozygosity on 13q, of whom 11 had concurrent homozygous del(13q). Genomic complexity and large 13q deletions correlated with inferior outcome, while the former was linked to poor-prognostic aberrations. In the follow-up study, clonal evolution developed in 8/24 (33%) patients with unmutated IGHV, and in 4/25 (16%) IGHV-mutated and treated patients. In contrast, untreated patients with mutated IGHV (n=10) did not acquire additional aberrations. The most common secondary event, del(13q), was detected in 6/12 (50%) of all patients with acquired alterations. Interestingly, aberrations on, for example, chromosome 6q, 8p, 9p and 10q developed exclusively in patients with unmutated IGHV. Conclusions Whole-genome screening revealed a high frequency of genomic aberrations in newly diagnosed chronic lymphocytic leukemia. Clonal evolution was associated with other markers of aggressive disease and commonly included the known recurrent aberrations.
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