1,721,031 research outputs found
Genetic and epigenetic complexity in myeloproliferative neoplasms
No full textThe past 7 years have witnessed remarkable progress in our understanding of the genetics of BCR-ABL-negative myeloproliferative neoplasms (MPNs) and has revealed layers of unexpected complexity. Deregulation of JAK2 signaling has emerged as a central feature, but despite having biological activities that recapitulate the cardinal features MPNs in model systems, JAK2 mutations are often secondary events. Several other mutated genes have been identified with a common theme of involvement in the epigenetic control of gene expression. Remarkably, the somatic mutations identified to date do not seem to be acquired in any preferred order, and it is possible that the disease-initiating events remain to be identified. The finding of complex clonal hierarchies in many cases suggests genetic instability that, in principle, may be inherited or acquired. A common haplotype has been identified that is strongly associated with the acquisition of JAK2 mutations, but the cause of relatively high-penetrance familial predisposition to MPNs remains elusive. This review summarizes the established facts relating to the genetics of MPNs, but highlights recent findings and areas of controversy.<br/
Molecular monitoring of chronic myeloid leukemia: principles and interlaboratory standardization
No full textSerial quantification of BCR-ABL1 messenger RNA (mRNA) is an important therapeutic indicator for patients with chronic myeloid leukemia, but historically, there has been substantial variation in results reported by different laboratories. To help improve the comparability of results, an international scale (IS) for BCR-ABL1 was proposed which is being implemented by testing laboratories worldwide. This is being achieved most commonly by the derivation of laboratory-specific conversion factors, but increasingly by the use of kits or reagents that are calibrated to the first World Health Organization International Genetic Reference Panel for quantitation of BCR-ABL1 mRNA. Recent attention has focused on the need to define and validate levels of deeper molecular response (MR) within the context of the IS. While there has been substantial progress in the alignment of results, BCR-ABL1 measurement is technically challenging and standardization is an ongoing process. <br/
Ponatinib as targeted therapy for FGFR1 fusions associated with the 8p11 myeloproliferative syndrome
No full textThe 8p11 myeloproliferative syndrome is a rare, aggressive myeloproliferative neoplasm characterised by constitutively active FGFR1 fusion proteins that arise from specificchromosomal translocations and which drive aberrant proliferation. Although FGFR1 inhibitors have shown in vitro activity against FGFR1 fusions, none are in use clinically and there is a need to assess additional compounds as potential therapy. Here we use cell linesand primary cells to investigate ponatinib (AP24534). Ponatinib-treated Ba/F3 cells transformed by ZMYM2-FGFR1 and BCR-FGFR1 and the FGFR1OP2-FGFR1 positiveKG1A cell line showed reduced proliferation and decreased survival when compared to control cells. Inhibition induced apoptosis and reduced phosphorylation of the FGFR1 fusionproteins and substrates. Ponatinib-treated cells from five 8p11 myeloproliferative syndrome patients showed reduced colony growth compared to controls. In one evaluable patient, ponatinib specifically reduced numbers of FGFR1-fusion gene positive colonies. Ponatinib therefore shows considerable promise for the treatment of patients with 8p11myeloproliferative syndrome
Cytogenetics of chronic myeloid leukaemia
No full textThe standard Philadelphia (Ph) translocation t(9;22), its variants and a proportion of Ph-negative cases are positive for the BCR-ABL fusion gene, as determined by molecular analysis. Extensive deletions of chromosome 9 and 22 derived sequences around the translocation breakpoints on the derivative 9 are seen in 10–30% of patients at diagnosis and may confer a worse prognosis. Additional cytogenetic changes can occur in the few months before or during disease progression and are often specific for blast morphology; however, the molecular basis of the most common additional cytogenetic abnormalities is largely unknown. Cytogenetics is important for monitoring patient response to treatment but is increasingly being replaced by the more sensitive and less invasive techniques of RT-PCR and FISH
Age-related loss of chromosome Y is associated with levels of sex hormone binding globulin and clonal hematopoiesis defined by TET2, TP53, and CBL mutations
No full textMosaic loss of the Y-chromosome (LOY) is the most common somatic alteration in men. We aimed to assess the relationship between LOY and serum biomarkers in UK Biobank and explore the interaction with constitutional and somatic genetics. LOY was strongly associated with levels of sex hormone binding globulin (SHBG, β=0.12, PFDR= P = 7.44×10−36, adjusted for age, age squared, gender, smoking status, smoking intensity and principal genetic components), a key regulator of testosterone bioavailability associated with diverse disorders including cancer and autoimmune diseases. Furthermore, LOY was associated with total testosterone (TT, β=0.09, PFDR=2.23 × 10−20), but not bioavailable testosterone (PFDR=0.46) or free testosterone (PFDR=0.75). These relationships remained significant after sensitivity analysis that included comorbidities and body mass index (SHBG, β = 0.08, PFDR = 4.61×10−21; TT, β = 0.05, PFDR = 4.13 × 10−9). Mendelian randomisation suggested a causal effect of SHBG on LOY in BioBank Japan (P=6.58×10−4) but there was no evidence for an effect of LOY on SHBG (P=0.46). Assessment of cis-eQTLs for 13 genes associated with LOY identified two SNPs that were also associated with levels of SHBG, however only rs7141210 (imprinted DLK1-MEG3 locus) modified the relationship between SHBG and LOY (rs7141210-T/T; Pinteraction=0.04) with low levels of SHBG seen specifically in men without LOY (β=-0.02, P=0.001), but not those with LOY (P=0.41). Age-related clonal hematopoiesis (CH) defined by somatic driver mutations was not associated with sex hormone levels but was associated with LOY at clonal fractions >30% (OR=1.52, P=2.92×10−4). TET2, TP53, and CBL mutations were enriched in high level LOY cases, but not DNMT3A or ASXL1. Our findings thus identify independent relationships between LOY, sex hormones and CH
Clonal myelopoiesis promotes adverse outcomes in chronic kidney disease
No full textWe sought to determine the relationship between age-related clonal hematopoiesis (CH) and chronic kidney disease (CKD). CH, defined as mosaic chromosome abnormalities (mCA) and/or driver mutations was identified in 5449 (2.9%) eligible UK Biobank participants (n = 190,487 median age = 58 years). CH was negatively associated with glomerular filtration rate estimated from cystatin-C (eGFR.cys; β = −0.75, P = 2.37 × 10
–4), but not with eGFR estimated from creatinine, and was specifically associated with CKD defined by eGFR.cys < 60 (OR = 1.02, P = 8.44 × 10
–8). In participants without prevalent myeloid neoplasms, eGFR.cys was associated with myeloid mCA (n = 148, β = −3.36, P = 0.01) and somatic driver mutations (n = 3241, β = −1.08, P = 6.25 × 10
–5) associated with myeloid neoplasia (myeloid CH), specifically mutations in CBL, TET2, JAK2, PPM1D and GNB1 but not DNMT3A or ASXL1. In participants with no history of cardiovascular disease or myeloid neoplasms, myeloid CH increased the risk of adverse outcomes in CKD (HR = 1.6, P = 0.002) compared to those without myeloid CH. Mendelian randomisation analysis provided suggestive evidence for a causal relationship between CH and CKD (P = 0.03). We conclude that CH, and specifically myeloid CH, is associated with CKD defined by eGFR.cys. Myeloid CH promotes adverse outcomes in CKD, highlighting the importance of the interaction between intrinsic and extrinsic factors to define the health risk associated with CH.
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Favorable outcome of allogeneic hematopoietic cell transplantation for 8p11 myeloproliferative syndrome associated with BCR-FGFR1 gene fusion
No full textWe report the case of a child who presented with nonspecificsymptoms suggestive of a rheumatologic disorder, whose bonemarrow had a complex translocation involving the FGFR1 locus.Hematopathologic findings were subtle and did not definitivelyindicate malignancy. Because he responded poorly to initial treatmentwith hydroxyurea, and in light of the progressive clinicalcourse associated with the 8p11 myeloproliferative syndrome, heunderwent an unrelated-donor hematopoietic stem cell transplant.This patient’s atypical presentation highlights the importance ofobtaining cytogenetic analysis at the time of bone marrow samplingand considering this uncommon entity in the differential diagnosisof hematologic disorders
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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