80 results found
Dawson MA, Borthakur G, Huntly B, et al., 2022, A phase I/II open-label study of molibresib for the treatment of relapsed/refractory hematologic malignancies., Clin Cancer Res
PURPOSE: Molibresib is a selective, small molecule inhibitor of the BET protein family. This was an open-label, two-part, Phase I/II study investigating molibresib monotherapy for the treatment of hematological malignancies (NCT01943851). EXPERIMENTAL DESIGN: Part 1 (dose escalation) determined the recommended Phase 2 dose (RP2D) of molibresib in patients with acute myeloid leukemia (AML), non-Hodgkin's 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). RESULTS: There were 111 patients enrolled (87 in Part 1, 24 in Part 2). Molibresib RP2Ds of 75 mg QD (for MDS) and 60 mg QD (for CTCL) were selected. Most common Grade 3+ AEs included thrombocytopenia (37%), anemia (15%) and febrile neutropenia (15%). Six patients achieved complete responses (three in Part 1 [two AML, one NHL], three in Part 2 [MDS]), and seven patients achieved partial responses (six in Part 1 [four AML, two NHL], one in Part 2 [MDS]). The ORRs for Part 1, Part 2, and the total study population were 10% (95% CI: 4.8-18.7), 25% (95% CI: 7.3-52.4), and 13% (95% CI: 6.9-20.6), respectively. CONCLUSIONS: While anti-tumor activity was observed with molibresib, use was limited by gastrointestinal and thrombocytopenia toxicities. Investigations of molibresib as part of combination regimens may be warranted.
Trasanidis N, Katsarou A, Ponnusamy K, et al., 2022, Systems medicine dissection of chr1q-amp reveals a novel PBX1-FOXM1 axis for targeted therapy in multiple myeloma, BLOOD, Vol: 139, Pages: 1939-1953, ISSN: 0006-4971
Ponnusamy K, Tzioni MM, Begum M, et al., 2022, The innate sensor ZBP1-IRF3 axis regulates cell proliferation in multiple myeloma, HAEMATOLOGICA, Vol: 107, Pages: 721-732, ISSN: 0390-6078
Roy A, Wang G, Iskander D, et al., 2021, Transitions in lineage specification and gene regulatory networks in hematopoietic stem/progenitor cells over human development, CELL REPORTS, Vol: 36, ISSN: 2211-1247
Karadimitris A, 2021, Chromatin-based, in cis and in trans regulatory rewiring underpins distinct oncogenic transcriptomes in multiple myeloma, Nature Communications, Vol: 12, Pages: 1-16, ISSN: 2041-1723
Multiple myeloma is a genetically heterogeneous cancer of the bone marrow plasma cells (PC). Distinct myeloma transcriptome profiles are primarily driven by myelomainitiating events (MIE) and converge into a mutually exclusive overexpression of the CCND1 and CCND2 oncogenes. Here, with reference to their normal counterparts, we find that myeloma PC enhanced chromatin accessibility combined with paired transcriptome profiling can classify MIE-defined genetic subgroups. Across and within different MM genetic subgroups, we ascribe regulation of genes and pathways critical for myeloma biology to unique or shared, developmentally activated or de novo formed candidate enhancers. Such enhancers co-opt recruitment of existing transcription factors, which although not transcriptionally deregulated per se, organise aberrant gene regulatory networks that help identify myeloma cell dependencies with prognostic impact. Finally, we identify and validate the critical super-enhancer that regulates ectopic expression of CCND2 in a subset of patients with MM and in chronic lymphocytic leukemia.
Iskander D, Wang G, Heuston EF, et al., 2021, Single-cell profiling of human bone marrow progenitors reveals mechanisms of failing erythropoiesis in Diamond-Blackfan anemia, SCIENCE TRANSLATIONAL MEDICINE, Vol: 13, ISSN: 1946-6234
Saavedra-Garcia P, Roman-Trufero M, Al-Sadah HA, et al., 2021, Systems level profiling of chemotherapy-induced stress resolution in cancer cells reveals druggable trade-offs, Proceedings of the National Academy of Sciences of USA, Vol: 118, ISSN: 0027-8424
Cancer cells can survive chemotherapy-induced stress, but how they recover from it is not known.Using a temporal multiomics approach, we delineate the global mechanisms of proteotoxic stressresolution in multiple myeloma cells recovering from proteasome inhibition. Our observations definelayered and protracted programmes for stress resolution that encompass extensive changes acrossthe transcriptome, proteome, and metabolome. Cellular recovery from proteasome inhibitioninvolved protracted and dynamic changes of glucose and lipid metabolism and suppression ofmitochondrial function. We demonstrate that recovering cells are more vulnerable to specific insultsthan acutely stressed cells and identify the general control nonderepressable 2 (GCN2)-driven cellularresponse to amino acid scarcity as a key recovery-associated vulnerability. Using a transcriptomeanalysis pipeline, we further show that GCN2 is also a stress-independent bona fide target intranscriptional signature-defined subsets of solid cancers that share molecular characteristics. Thus,identifying cellular trade-offs tied to the resolution of chemotherapy-induced stress in tumour cellsmay reveal new therapeutic targets and routes for cancer therapy optimisation.
Caputo VS, Trasanidis N, Xiao X, et al., 2021, Brd2/4 and Myc regulate alternative cell lineage programmes during early osteoclast differentiation in vitro, iScience, Vol: 24, Pages: 1-31, ISSN: 2589-0042
Osteoclast development in response to RANKL is critical for bone homeostasis in health and in disease. The early and direct chromatin regulatory changes imparted by the BET chromatin readers Brd2-4 and osteoclast-affiliated transcription factors (TF) during osteoclastogenesis are not known. Here, we demonstrate that in response to RANKL, early osteoclast development entails regulation of two alternative cell fate transcriptional programmes, osteoclast vs macrophage, with repression of the latter following activation of the former. Both programmes are regulated in a non-redundant manner by increased chromatin binding of Brd2 at promoters and of Brd4 at enhancers/super-enhancers. Myc, the top RANKL-induced TF, regulates osteoclast development in co-operation with Brd2/4 and Max and by establishing negative and positive regulatory loops with other lineage-affiliated TF. These insights into the transcriptional regulation of osteoclastogenesis suggest the clinical potential of selective targeting of Brd2/4 to abrogate pathological OC activation.
Iskander D, Wang G, Heuston EF, et al., 2020, Single-Cell Transcriptional Landscapes of Human Bone Marrow Reveal Distinct Erythroid Phenotypes Underpinned By Genotype in Diamond-Blackfan Anemia, Publisher: AMER SOC HEMATOLOGY, ISSN: 0006-4971
Luzzatto L, Karadimitris A, 2020, Paroxysmal nocturnal haemoglobinuria (PNH): novel therapies for an ancient disease, BRITISH JOURNAL OF HAEMATOLOGY, Vol: 191, Pages: 579-586, ISSN: 0007-1048
Chaidos A, Katsarou A, Mustafa C, et al., 2020, Interleukin 6-blockade treatment for severe COVID-19 in two patients with multiple myeloma, BRITISH JOURNAL OF HAEMATOLOGY, Vol: 190, Pages: E9-E11, ISSN: 0007-1048
Karadimitris A, 2020, Cord Blood CAR-NK Cells: Favorable Initial Efficacy and Toxicity but Durability of Clinical Responses Not Yet Clear, CANCER CELL, Vol: 37, Pages: 426-427, ISSN: 1535-6108
Ponnusamy K, Tzioni M-M, Begum M, et al., 2019, Novel ZBP1-IRF3 Dependency in Multiple Myeloma Mediated By IRF3-Driven Regulation of Cell Cycle Genes, BLOOD, Vol: 134, ISSN: 0006-4971
Trasanidis N, Katsarou A, Bergonia B, et al., 2019, PBX1 Co-Operates with FOXM1 to Regulate Myeloma Cell Proliferation and to Define an Ultra High-Risk chr1q Gain Myeloma Patient Subgroup, BLOOD, Vol: 134, ISSN: 0006-4971
Caputo VS, Trasanidis N, Xiao X, et al., 2019, Myc and Bet Proteins Orchestrate the Early Regulatory Genome Changes Required for Osteoclast Lineage Commitment, 61st Annual Meeting and Exposition of the American-Society-of-Hematology (ASH), Publisher: AMER SOC HEMATOLOGY, ISSN: 0006-4971
Katsarou A, Trasanidis N, Alvarez-Benayas J, et al., 2019, Oncogenic MAF in Co-Operation with IRF4 Confers Extensive Chromatin Re-Arrangement in Plasma Cells and Generates 'Neo-Enhancers' That Regulate Genes Critical for Myeloma Biology, 61st Annual Meeting and Exposition of the American-Society-of-Hematology (ASH), Publisher: AMER SOC HEMATOLOGY, ISSN: 0006-4971
Rotolo A, Caputo VS, Holubova M, et al., 2018, Enhanced anti-lymphoma activity of CAR19-iNKT cells underpinned by dual CD19 and CD1d targeting, Cancer Cell, Vol: 34, Pages: 596-610.e11, ISSN: 1535-6108
Chimeric antigen receptor anti-CD19 (CAR19)-T cell immunotherapy-induced clinical remissions in CD19+ B cell lymphomas are often short lived. We tested whether CAR19-engineering of the CD1d-restricted invariant natural killer T (iNKT) cells would result in enhanced anti-lymphoma activity. CAR19-iNKT cells co-operatively activated by CD1d- and CAR19-CD19-dependent interactions are more effective than CAR19-T cells against CD1d-expressing lymphomas in vitro and in vivo. The swifter in vivo anti-lymphoma activity of CAR19-iNKT cells and their enhanced ability to eradicate brain lymphomas underpinned an improved tumor-free and overall survival. CD1D transcriptional de-repression by all-trans retinoic acid results in further enhanced cytotoxicity of CAR19-iNKT cells against CD19+ chronic lymphocytic leukemia cells. Thus, iNKT cells are a highly efficient platform for CAR-based immunotherapy of lymphomas and possibly other CD1d-expressing cancers.
Rotolo A, Karadimitris A, Ruella M, 2018, Building upon the success of CART19: chimeric antigen receptor T cells for hematologic malignancies, LEUKEMIA & LYMPHOMA, Vol: 59, Pages: 2040-2055, ISSN: 1042-8194
Roy A, Bystry V, Bohn G, et al., 2017, High resolution IgH repertoire analysis reveals fetal liver as the likely origin of life-long, innate B lymphopoiesis in humans, Clinical Immunology, Vol: 183, Pages: 8-16, ISSN: 1521-6616
The ontogeny of the natural, public IgM repertoire remains incompletely explored. Here, high-resolution immunogenetic analysis of B cells from (unrelated) fetal, child, and adult samples, shows that although fetal liver (FL) and bone marrow (FBM) IgM repertoires are equally diversified, FL is the main source of IgM natural immunity during the 2nd trimester. Strikingly, 0.25% of all prenatal clonotypes, comprising 18.7% of the expressed repertoire, are shared with the postnatal samples, consistent with persisting fetal IgM+ B cells being a source of natural IgM repertoire in adult life. Further, the origins of specific stereotypic IgM+ B cell receptors associated with chronic lymphocytic leukemia, can be traced back to fetal B cell lymphopoiesis, suggesting that persisting fetal B cells can be subject to malignant transformation late in life. Overall, these novel data provide unique insights into the ontogeny of physiological and malignant B lymphopoiesis that spans the human lifetime.
Spanoudakis E, Papoutselis M, Terpos E, et al., 2016, Overexpression of RANKL by invariant NKT cells enriched in the bone marrow of patients with multiple myeloma, BLOOD CANCER JOURNAL, Vol: 6, ISSN: 2044-5385
Psaila B, Barkas N, Iskander D, et al., 2016, Single-cell profiling of human megakaryocyte-erythroid progenitors identifies distinct megakaryocyte and erythroid differentiation pathways, Genome Biology, Vol: 17, Pages: 1-19, ISSN: 1474-760X
BACKGROUND: Recent advances in single-cell techniques have provided the opportunity to finely dissect cellular heterogeneity within populations previously defined by "bulk" assays and to uncover rare cell types. In human hematopoiesis, megakaryocytes and erythroid cells differentiate from a shared precursor, the megakaryocyte-erythroid progenitor (MEP), which remains poorly defined. RESULTS: To clarify the cellular pathway in erythro-megakaryocyte differentiation, we correlate the surface immunophenotype, transcriptional profile, and differentiation potential of individual MEP cells. Highly purified, single MEP cells were analyzed using index fluorescence-activated cell sorting and parallel targeted transcriptional profiling of the same cells was performed using a specifically designed panel of genes. Differentiation potential was tested in novel, single-cell differentiation assays. Our results demonstrate that immunophenotypic MEP comprise three distinct subpopulations: "Pre-MEP," enriched for erythroid/megakaryocyte progenitors but with residual myeloid differentiation capacity; "E-MEP," strongly biased towards erythroid differentiation; and "MK-MEP," a previously undescribed, rare population of cells that are bipotent but primarily generate megakaryocytic progeny. Therefore, conventionally defined MEP are a mixed population, as a minority give rise to mixed-lineage colonies while the majority of cells are transcriptionally primed to generate exclusively single-lineage output. CONCLUSIONS: Our study clarifies the cellular hierarchy in human megakaryocyte/erythroid lineage commitment and highlights the importance of using a combination of single-cell approaches to dissect cellular heterogeneity and identify rare cell types within a population. We present a novel immunophenotyping strategy that enables the prospective identification of specific intermediate progenitor populations in erythro-megakaryopoiesis, allowing for in-de
Rotolo A, Caputo V, Karadimitris A, 2016, The prospects and promise of chimeric antigen receptor immunotherapy in multiple myeloma, British Journal of Haematology, Vol: 173, Pages: 350-364, ISSN: 1365-2141
Despite encouraging therapeutic advances, multiple myeloma (MM) remains an incurable malignancy. The exciting results of chimaeric antigen receptor (CAR)-based immunotherapy in CD19+ B-cell malignancies have spurred a great interest in extending the use of the CAR technology to other cancers, including MM.Availability of a specific, tumour-restricted antigen is crucial for the design of successful antibody-based CAR therapy. However, in MM, as in other malignancies, the relative dearth of such antigens-targets represents the main obstacle for the wider pre-clinical development and clinical application of the CAR technology.Here we provide an overview of the current progress and future promises of CAR technology in MM therapy. We highlight that, owing to its complexity, phenotypic and functional heterogeneity and the impact of the microenvironment, MM poses several challenges for CAR-based therapeutic approaches. Nevertheless, for the same reasons, MM can serve as a paradigm for better understanding, optimization and overall improvement of the CAR technology for the benefit of cancer and myeloma patients.
Karadimitris A, Chaidos A, Caputo V, et al., 2015, Myeloma Propagating Cells, Drug Resistance and Relapse, STEM CELLS, Vol: 33, Pages: 3205-3211, ISSN: 1066-5099
Chaidos A, Caputo V, Karadimitris A, 2015, Inhibition of bromodomain and extraterminal proteins (BET) as a potential therapeutic approach in haematological malignancies: emerging preclinical and clinical evidence, THERAPEUTIC ADVANCES IN HEMATOLOGY, Vol: 6, Pages: 128-141, ISSN: 2040-6207
Psaltopoulou T, Sergentanis TN, Sergentanis IN, et al., 2015, Alcohol intake, alcoholic beverage type and multiple myeloma risk: a meta-analysis of 26 observational studies, LEUKEMIA & LYMPHOMA, Vol: 56, Pages: 1484-1501, ISSN: 1042-8194
Ersek A, Xu K, Antonopoulos A, et al., 2015, Glycosphingolipid synthesis inhibition limits osteoclast activation and myeloma bone disease, Journal of Clinical Investigation, Vol: 125, Pages: 2279-2292, ISSN: 1558-8238
Glycosphingolipids (GSLs) are essential constituents of cell membranes and lipid rafts and can modulate signal transduction events. The contribution of GSLs in osteoclast (OC) activation and osteolytic bone diseases in malignancies such as the plasma cell dyscrasia multiple myeloma (MM) is not known. Here, we tested the hypothesis that pathological activation of OCs in MM requires de novo GSL synthesis and is further enhanced by myeloma cell–derived GSLs. Glucosylceramide synthase (GCS) inhibitors, including the clinically approved agent N-butyl-deoxynojirimycin (NB-DNJ), prevented OC development and activation by disrupting RANKL-induced localization of TRAF6 and c-SRC into lipid rafts and preventing nuclear accumulation of transcriptional activator NFATc1. GM3 was the prevailing GSL produced by patient-derived myeloma cells and MM cell lines, and exogenous addition of GM3 synergistically enhanced the ability of the pro-osteoclastogenic factors RANKL and insulin-like growth factor 1 (IGF-1) to induce osteoclastogenesis in precursors. In WT mice, administration of GM3 increased OC numbers and activity, an effect that was reversed by treatment with NB-DNJ. In a murine MM model, treatment with NB-DNJ markedly improved osteolytic bone disease symptoms. Together, these data demonstrate that both tumor-derived and de novo synthesized GSLs influence osteoclastogenesis and suggest that NB-DNJ may reduce pathological OC activation and bone destruction associated with MM.
Iskander D, Psaila B, Gerrard G, et al., 2015, Elucidation of the EP defect in Diamond-Blackfan anemia by characterization and prospective isolation of human EPs, BLOOD, Vol: 125, Pages: 2553-2557, ISSN: 0006-4971
Johnston AC, Naresh K, Barwick T, et al., 2015, Cutaneous presentation of an aggressive plasmablastic neoplasm indiscriminate between lymphoma and myeloma, ANNALS OF HEMATOLOGY, Vol: 94, Pages: 691-692, ISSN: 0939-5555
Pitcher DS, de Mattos-Shipley K, Tzortzis K, et al., 2015, Bortezomib Amplifies Effect on Intracellular Proteasomes by Changing Proteasome Structure, EBioMedicine, Vol: 2, Pages: 642-648
The proteasome inhibitor Bortezomib is used to treat multiple myeloma (MM). Bortezomib inhibits protein degradation by inactivating proteasomes’ active-sites. MM cells are exquisitely sensitive to Bortezomib - exhibiting a low-nanomolar IC50 - suggesting that minimal inhibition of degradation suffices to kill MM cells. Instead, we report, a low Bortezomib concentration, contrary to expectation, achieves severe inhibition of proteasome activity in MM cells: the degree of inhibition exceeds what one would expect from the small proportion of active-sites that Bortezomib inhibits. Our data indicate that Bortezomib achieves this severe inhibition by triggering secondary changes in proteasome structure that further inhibit proteasome activity. Comparing MM cells to other, Bortezomib-resistant, cancer cells shows that the degree of proteasome inhibition is the greatest in MM cells and only there leads to proteasome stress, providing an explanation for why Bortezomib is effective against MM but not other cancers.
Chaudhry MS, Karadimitris A, 2014, Role and Regulation of CD1d in Normal and Pathological B Cells, JOURNAL OF IMMUNOLOGY, Vol: 193, Pages: 4761-4768, ISSN: 0022-1767
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