ORCID Profile
0000-0003-0312-161X
Current Organisations
Cambridge University Hospitals
,
University of Cambridge
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Publisher: Springer Science and Business Media LLC
Date: 19-12-2018
DOI: 10.1038/S41467-018-07620-0
Abstract: We recently identified the splicing kinase gene SRPK1 as a genetic vulnerability of acute myeloid leukemia (AML). Here, we show that genetic or pharmacological inhibition of SRPK1 leads to cell cycle arrest, leukemic cell differentiation and prolonged survival of mice transplanted with MLL -rearranged AML. RNA-seq analysis demonstrates that SRPK1 inhibition leads to altered isoform levels of many genes including several with established roles in leukemogenesis such as MYB , BRD4 and MED24 . We focus on BRD4 as its main isoforms have distinct molecular properties and find that SRPK1 inhibition produces a significant switch from the short to the long isoform at the mRNA and protein levels. This was associated with BRD4 eviction from genomic loci involved in leukemogenesis including BCL2 and MYC . We go on to show that this switch mediates at least part of the anti-leukemic effects of SRPK1 inhibition. Our findings reveal that SRPK1 represents a plausible new therapeutic target against AML.
Publisher: Informa UK Limited
Date: 12-2011
DOI: 10.1128/MCB.05830-11
Publisher: Springer Science and Business Media LLC
Date: 09-2015
DOI: 10.1038/NATURE14888
Publisher: American Society of Hematology
Date: 21-04-2022
Abstract: The accessibility of cell surface proteins makes them tractable for targeting by cancer immunotherapy, but identifying suitable targets remains challenging. Here we describe plasma membrane profiling of primary human myeloma cells to identify an unprecedented number of cell surface proteins of a primary cancer. We used a novel approach to prioritize immunotherapy targets and identified a cell surface protein not previously implicated in myeloma, semaphorin-4A (SEMA4A). Using knock-down by short-hairpin RNA and CRISPR/nuclease-dead Cas9 (dCas9), we show that expression of SEMA4A is essential for normal myeloma cell growth in vitro, indicating that myeloma cells cannot downregulate the protein to avoid detection. We further show that SEMA4A would not be identified as a myeloma therapeutic target by standard CRISPR/Cas9 knockout screens because of exon skipping. Finally, we potently and selectively targeted SEMA4A with a novel antibody-drug conjugate in vitro and in vivo.
Publisher: American Society of Hematology
Date: 07-07-2011
DOI: 10.1182/BLOOD-2010-12-327593
Abstract: The JAK2 V617F mutation is present in the majority of patients with a myeloproliferative neoplasm (MPN) and is sufficient to recapitulate an MPN in murine models. However, the consequences of JAK2 mutations for myeloid differentiation are poorly understood. After systematic analyses of a large cohort of JAK2-mutated MPN patients, we demonstrate in vivo that JAK2 mutations do not alter hematopoietic stem and progenitor cell com-partment size or in vitro behavior but generate expansion of later myeloid differentiation compartments, where homozygous expression of the mutation confers an added proliferative advantage at the single-cell level. In addition, we demonstrate that these findings may be partially explained by the expression pattern of JAK2, which markedly increases on myeloid differentiation. Our findings have potential clinical relevance, as they predict that JAK2 inhibitors may control myeloproliferation, but may have limited efficacy in eradicating the leukemic stem cells that sustain the human MPN.
Publisher: Springer Science and Business Media LLC
Date: 10-2011
DOI: 10.1038/NATURE10509
Publisher: Massachusetts Medical Society
Date: 16-08-2012
Publisher: American Society of Hematology
Date: 21-03-2013
DOI: 10.1182/BLOOD-2012-07-446120
Abstract: The ERG stem cell enhancer is active in acute myeloid leukemia and is regulated by a heptad of transcription factors. Expression signatures derived from ERG promoter–enhancer activity and heptad expression are associated with clinical outcome.
Publisher: American Society of Hematology
Date: 12-12-2019
Abstract: Cohesin mutations are common in myeloid malignancy. Sasca et al elucidate the potential role of cohesin loss in myelodysplastic syndrome and acute myeloid leukemia (MDS/AML). They demonstrate that cohesin binding is critical for erythroid-specific gene expression and that reduction in cohesin impairs terminal erythroid maturation and promotes myeloid malignancy.
Publisher: Public Library of Science (PLoS)
Date: 28-01-2011
Publisher: American Society of Hematology
Date: 28-07-2011
DOI: 10.1182/BLOOD-2011-02-338848
Abstract: The t(12 ) translocation that generates the ETV6-RUNX1 (TEL-AML1) fusion gene, is the most common chromosomal rearrangement in childhood cancer and is exclusively associated with B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The translocation arises in utero and is necessary but insufficient for the development of leukemia. Single-nucleotide polymorphism array analysis of ETV6-RUNX1 patient s les has identified multiple additional genetic alterations however, the role of these lesions in leukemogenesis remains undetermined. Moreover, murine models of ETV6-RUNX1 ALL that faithfully recapitulate the human disease are lacking. To identify novel genes that cooperate with ETV6-RUNX1 in leukemogenesis, we generated a mouse model that uses the endogenous Etv6 locus to coexpress the Etv6-RUNX1 fusion and Sleeping Beauty transposase. An insertional mutagenesis screen was performed by intercrossing these mice with those carrying a Sleeping Beauty transposon array. In contrast to previous models, a substantial proportion (20%) of the offspring developed BCP-ALL. Isolation of the transposon insertion sites identified genes known to be associated with BCP-ALL, including Ebf1 and Epor, in addition to other novel candidates. This is the first mouse model of ETV6-RUNX1 to develop BCP-ALL and provides important insight into the cooperating genetic alterations in ETV6-RUNX1 leukemia.
Publisher: Springer Science and Business Media LLC
Date: 04-07-2018
DOI: 10.1038/LEU.2017.210
Abstract: Prognostic gene expression signatures have been proposed as clinical tools to clarify therapeutic options in acute myeloid leukemia (AML). However, these signatures rely on measuring large numbers of genes and often perform poorly when applied to independent cohorts or those with older patients. Long intergenic non-coding RNAs (lincRNAs) are emerging as important regulators of cell identity and oncogenesis, but knowledge of their utility as prognostic markers in AML is limited. Here we analyze transcriptomic data from multiple cohorts of clinically annotated AML patients and report that (i) microarrays designed for coding gene expression can be repurposed to yield robust lincRNA expression data, (ii) some lincRNA genes are located in close proximity to hematopoietic coding genes and show strong expression correlations in AML, (iii) lincRNA gene expression patterns distinguish cytogenetic and molecular subtypes of AML, (iv) lincRNA signatures composed of three or four genes are independent predictors of clinical outcome and further dichotomize survival in European Leukemia Net (ELN) risk groups and (v) an analytical tool based on logistic regression analysis of quantitative PCR measurement of four lincRNA genes (LINC4) can be used to determine risk in AML.
Publisher: Springer Science and Business Media LLC
Date: 02-08-2010
DOI: 10.1038/ONC.2010.320
Abstract: The T-cell oncogene Lim-only 2 (LMO2) critically influences both normal and malignant haematopoiesis. LMO2 is not normally expressed in T cells, yet ectopic expression is seen in the majority of T-acute lymphoblastic leukaemia (T-ALL) patients with specific translocations involving LMO2 in only a subset of these patients. Ectopic lmo2 expression in thymocytes of transgenic mice causes T-ALL, and retroviral vector integration into the LMO2 locus was implicated in the development of clonal T-cell disease in patients undergoing gene therapy. Using array-based chromatin immunoprecipitation, we now demonstrate that in contrast to B-acute lymphoblastic leukaemia, human T-ALL s les largely use promoter elements with little influence from distal enhancers. Active LMO2 promoter elements in T-ALL included a previously unrecognized third promoter, which we demonstrate to be active in cell lines, primary T-ALL patients and transgenic mice. The ETS factors ERG and FLI1 previously implicated in lmo2-dependent mouse models of T-ALL bind to the novel LMO2 promoter in human T-ALL s les, while in return LMO2 binds to blood stem rogenitor enhancers in the FLI1 and ERG gene loci. Moreover, LMO2, ERG and FLI1 all regulate the +1 enhancer of HHEX/PRH, which was recently implicated as a key mediator of early progenitor expansion in LMO2-driven T-ALL. Our data therefore suggest that a self-sustaining triad of LMO2/ERG/FLI1 stabilizes the expression of important mediators of the leukaemic phenotype such as HHEX/PRH.
Publisher: Springer Science and Business Media LLC
Date: 09-08-2013
DOI: 10.1038/LEU.2013.234
Abstract: Small molecule inhibition of the BET family of proteins, which bind acetylated lysines within histones, has been shown to have a marked therapeutic benefit in pre-clinical models of mixed lineage leukemia (MLL) fusion protein-driven leukemias. Here, we report that I-BET151, a highly specific BET family bromodomain inhibitor, leads to growth inhibition in a human erythroleukemic (HEL) cell line as well as in erythroid precursors isolated from polycythemia vera patients. One of the genes most highly downregulated by I-BET151 was LMO2, an important oncogenic regulator of hematopoietic stem cell development and erythropoiesis. We previously reported that LMO2 transcription is dependent upon Janus kinase 2 (JAK2) kinase activity in HEL cells. Here, we show that the transcriptional changes induced by a JAK2 inhibitor (TG101209) and I-BET151 in HEL cells are significantly over-lapping, suggesting a common pathway of action. We generated JAK2 inhibitor resistant HEL cells and showed that these retain sensitivity to I-BET151. These data highlight I-BET151 as a potential alternative treatment against myeloproliferative neoplasms driven by constitutively active JAK2 kinase.
Publisher: Springer Science and Business Media LLC
Date: 23-09-2021
Publisher: Wiley
Date: 11-09-2012
DOI: 10.1002/CYTO.A.22116
Abstract: Mutations within the nucleophosmin NPM1 gene occur in approximately one-third of cases of acute myeloid leukemia (AML). These mutations result in cytoplasmic accumulation of the mutant NPM protein. NPM1 mutations are currently detected by molecular methods. Using s les from 37 AML patients, we investigated whether imaging flow cytometry could be a viable alternative to this current technique. Bone marrow eripheral blood cells were stained with anti-NPM antibody and DRAQ5 nuclear stain, and data were acquired on an ImageStream imaging flow cytometer (Amnis Corp., Seattle, USA). Using the similarity feature for data analysis, we demonstrated that this technique could successfully identify cases of AML with a NPM1 mutation based on cytoplasmic NPM protein staining (at similarity threshold of 1.1 sensitivity 88% and specificity 90%). Combining data of mean fluorescence intensity and % dissimilar staining in a 0-2 scoring system further improved the sensitivity (100%). Imaging flow cytometry has the potential to be included as part of a standard flow cytometry antibody panel to identify potential NPM1 mutations as part of diagnosis and minimal residual disease monitoring. Imaging flow cytometry is an exciting technology that has many possible applications in the diagnosis of hematological malignancies, including the potential to integrate modalities.
Publisher: American Society of Hematology
Date: 02-09-2010
DOI: 10.1182/BLOOD-2009-12-259747
Abstract: The JAK2 V617F mutation is found in most patients with a myeloproliferative neoplasm and is sufficient to produce a myeloproliferative phenotype in murine retroviral transplantation or transgenic models. However, several lines of evidence suggest that disease phenotype is influenced by the level of mutant JAK2 signaling, and we have therefore generated a conditional knock-in mouse in which a human JAK2 V617F is expressed under the control of the mouse Jak2 locus. Human and murine Jak2 transcripts are expressed at similar levels, and mice develop modest increases in hemoglobin and platelet levels reminiscent of human JAK2 V617F–positive essential thrombocythemia. The phenotype is transplantable and accompanied by increased terminal erythroid and megakaryocyte differentiation together with increased numbers of clonogenic progenitors, including erythropoietin-independent erythroid colonies. Unexpectedly, JAK2V617F mice develop reduced numbers of lineage−Sca-1+c-Kit+ cells, which exhibit increased DNA damage, reduced apoptosis, and reduced cell cycling. Moreover, competitive bone marrow transplantation studies demonstrated impaired hematopoietic stem cell function in JAK2V617F mice. These results suggest that the chronicity of human myeloproliferative neoplasms may reflect a balance between impaired hematopoietic stem cell function and the accumulation of additional mutations.
Publisher: American Society of Hematology
Date: 15-11-2006
DOI: 10.1182/BLOOD-2005-12-013748
Abstract: The identification of an acquired mutation of JAK2 in patients with myeloproliferative disorders has raised questions about the relationship between mutation-positive and mutation-negative subtypes, timing of the JAK2 mutation, and molecular mechanisms of disease progression. Here we demonstrate that patients with V617F(-) essential thrombocythemia do not commonly progress to become V617F(+). Consistent with the concept of distinct pathogenetic mechanisms, we show that patients with and without the JAK2 mutation have different patterns of cytogenetic abnormality, with virtually all patients carrying the 20q deletion or trisomy 9 being V617F(+). We also investigated the existence of a "pre-JAK2" phase by comparing the proportion of clonally derived granulocytes, estimated from X-chromosome inactivation patterns (XCIPs), with the proportion of V617F(+) granulocytes. Our results demonstrate that inherent XCIP variability between granulocytes and T cells produces a systematically biased pattern of results that may be misinterpreted as evidence for an excess of clonally derived granulocytes, an observation that limits the utility of XCIP analysis in this context. Lastly, we studied 4 patients with V617F(+) myeloproliferative disorders who subsequently developed acute myeloid leukemia. In 3 patients the leukemic cells were V617F(-), suggesting that in these patients the leukemia arose in a V617F(-) cell.
Publisher: Springer Science and Business Media LLC
Date: 13-11-2013
DOI: 10.1038/LEU.2013.338
Publisher: American Society of Hematology
Date: 15-09-2001
Publisher: Wiley
Date: 22-03-2010
DOI: 10.1111/J.1365-2141.2010.08083.X
Abstract: Approximately 50% of essential thrombocythaemia and primary myelo-fibrosis patients do not have a JAK2 V617F mutation. Up to 5% of these are reported to have a MPL exon 10 mutation but testing for MPL is not routine as there are multiple mutation types. The ability to routinely assess both JAK2 and MPL mutations would be beneficial in the differential diagnosis of unexplained thrombocytosis or myelofibrosis. We developed and applied a high resolution melt (HRM) assay, capable of detecting all known MPL mutations in a single analysis, for the detection of MPL exon 10 mutations. We assessed 175 ET and PMF patients, including 67 that were JAK2 V617F-negative by real time polymerase chain reaction (PCR). Overall, 19/175 (11%) patients had a MPL exon 10 mutation, of whom 16 were JAK2 V617F-negative (16/67 24%). MPL mutation types were W515L (11), W515K (4), W515R (2) and W515A (1). One patient had both W515L and S505N MPL mutations and these were present in the same haemopoietic colonies. Real time PCR for JAK2 V617F analysis and HRM for MPL exon 10 status identified one or more clonal marker in 71% of patients. This combined genetic approach increases the sensitivity of meeting the World Health Organization diagnostic criteria for these myeloproliferative neoplasms.
Publisher: Wiley
Date: 19-02-2009
DOI: 10.1111/J.1365-2141.2008.07560.X
Abstract: This study looked for clonal ersity in patients with a myeloproliferative neoplasm associated with more than one acquired genetic lesion. A tyrosine kinase mutation and a cytogenetic lesion were present in the same clone in six of seven patients. By contrast, the genetic lesions were present in separate clones in all six patients with two tyrosine kinase pathway mutations. Moreover, in two patients the clones were genetically unrelated by X-chromosome inactivation studies. These data demonstrated clonal ersity in a subset of patients with early stage haematopoietic malignancy and showed, for the first time, that such clones may arise independently.
Publisher: American Association for Cancer Research (AACR)
Date: 09-11-2022
DOI: 10.1158/1078-0432.CCR-22-1284
Abstract: Molibresib is a selective, small molecule inhibitor of the bromodomain and extra-terminal (BET) protein family. This was an open-label, two-part, Phase I/II study investigating molibresib monotherapy for the treatment of hematological malignancies (NCT01943851). Part 1 (dose escalation) determined the recommended Phase 2 dose (RP2D) of molibresib in patients with acute myeloid leukemia (AML), Non–Hodgkin lymphoma (NHL), or multiple myeloma. Part 2 (dose expansion) investigated the safety and efficacy of molibresib at the RP2D in patients with relapsed/refractory myelodysplastic syndrome (MDS as well as AML evolved from antecedent MDS) or cutaneous T-cell lymphoma (CTCL). The primary endpoint in Part 1 was safety and the primary endpoint in Part 2 was objective response rate (ORR). There were 111 patients enrolled (87 in Part 1, 24 in Part 2). Molibresib RP2Ds of 75 mg daily (for MDS) and 60 mg daily (for CTCL) were selected. Most common Grade 3+ adverse events included thrombocytopenia (37%), anemia (15%), and febrile neutropenia (15%). Six patients achieved complete responses [3 in Part 1 (2 AML, 1 NHL), 3 in Part 2 (MDS)], and 7 patients achieved partial responses [6 in Part 1 (4 AML, 2 NHL), 1 in Part 2 (MDS)]. The ORRs for Part 1, Part 2, and the total study population were 10% [95% confidence interval (CI), 4.8–18.7], 25% (95% CI, 7.3–52.4), and 13% (95% CI, 6.9–20.6), respectively. While antitumor activity was observed with molibresib, use was limited by gastrointestinal and thrombocytopenia toxicities. Investigations of molibresib as part of combination regimens may be warranted.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for brian huntly.