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Gil JV, Miralles A, de las Heras S, Such E, Avetisyan G, Díaz-González Á, Santiago M, Fuentes C, Fernández JM, Lloret P, Navarro I, Montesinos P, Llop M, Barragán E. Comprehensive detection of CRLF2 alterations in acute lymphoblastic leukemia: a rapid and accurate novel approach. Front Mol Biosci 2024; 11:1362081. [PMID: 38370004 PMCID: PMC10869515 DOI: 10.3389/fmolb.2024.1362081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 01/22/2024] [Indexed: 02/20/2024] Open
Abstract
Introduction: Acute lymphoblastic leukemia (ALL) is a prevalent childhood cancer with high cure rate, but poses a significant medical challenge in adults and relapsed patients. Philadelphia-like acute lymphoblastic leukemia (Ph-like ALL) is a high-risk subtype, with approximately half of cases characterized by CRLF2 overexpression and frequent concomitant IKZF1 deletions. Methods: To address the need for efficient, rapid, and cost-effective detection of CRLF2 alterations, we developed a novel RT-qPCR technique combining SYBR Green and highresolution melting analysis on a single plate. Results: The method successfully identified CRLF2 expression, P2RY8::CRLF2 fusions, and CRLF2 and JAK2 variants, achieving a 100% sensitivity and specificity. Application of this method across 61 samples revealed that 24.59% exhibited CRLF2 overexpression, predominantly driven by IGH::CRLF2 (73.33%). High Resolution Melting analysis unveiled concurrent CRLF2 or JAK2 variants in 8.19% of samples, as well as a dynamic nature of CRLF2 alterations during disease progression. Discussion: Overall, this approach provides an accurate identification of CRLF2 alterations, enabling improved diagnostic and facilitating therapeutic decision-making.
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Affiliation(s)
- José Vicente Gil
- Accredited Research Group on Hematology, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
| | - Alberto Miralles
- Accredited Research Group on Hematology, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
| | - Sandra de las Heras
- Accredited Research Group on Hematology, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
| | - Esperanza Such
- Accredited Research Group on Hematology, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
- Hematology Service, Hospital Universitario y Politécnico la Fe, Valencia, Spain
- Centro de Investigación Biomédica en Red de Cáncer, CIBERONC CB16/12/00284, Instituto de Salud Carlos III, Madrid, Spain
| | - Gayane Avetisyan
- Accredited Research Group on Hematology, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
| | - Álvaro Díaz-González
- Accredited Research Group on Hematology, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
| | - Marta Santiago
- Accredited Research Group on Hematology, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
| | - Carolina Fuentes
- Accredited Research Group on Clinical and Translational Cancer Research, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
- Onco-Hematology Unit, Pediatrics Service, Hospital Universitario y Politécnico la Fe, Valencia, Spain
| | - José María Fernández
- Accredited Research Group on Clinical and Translational Cancer Research, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
- Onco-Hematology Unit, Pediatrics Service, Hospital Universitario y Politécnico la Fe, Valencia, Spain
| | - Pilar Lloret
- Accredited Research Group on Hematology, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
- Hematology Service, Hospital Universitario y Politécnico la Fe, Valencia, Spain
| | - Irene Navarro
- Accredited Research Group on Hematology, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
- Hematology Service, Hospital Universitario y Politécnico la Fe, Valencia, Spain
| | - Pau Montesinos
- Accredited Research Group on Hematology, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
- Hematology Service, Hospital Universitario y Politécnico la Fe, Valencia, Spain
| | - Marta Llop
- Accredited Research Group on Hematology, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
- Centro de Investigación Biomédica en Red de Cáncer, CIBERONC CB16/12/00284, Instituto de Salud Carlos III, Madrid, Spain
- Molecular Biology Unit, Clinical Analysis Service, Hospital Universitario y Politécnico la Fe, Valencia, Spain
| | - Eva Barragán
- Accredited Research Group on Hematology, Instituto de Investigación Sanitaria la Fe, Valencia, Spain
- Centro de Investigación Biomédica en Red de Cáncer, CIBERONC CB16/12/00284, Instituto de Salud Carlos III, Madrid, Spain
- Molecular Biology Unit, Clinical Analysis Service, Hospital Universitario y Politécnico la Fe, Valencia, Spain
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2
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Maiques-Diaz A, Martin-Subero JI. Biological, prognostic, and therapeutic impact of the epigenome in CLL. Semin Hematol 2023:S0037-1963(23)00092-6. [PMID: 38151379 DOI: 10.1053/j.seminhematol.2023.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 11/22/2023] [Indexed: 12/29/2023]
Abstract
Chronic lymphocytic leukemia (CLL) is characterized by widespread alterations in the genetic and epigenetic landscapes which seem to underlie the variable clinical manifestations observed in patients. Over the last decade, epigenomic studies have described the whole-genome maps of DNA methylation and chromatin features of CLL and normal B cells, identifying distinct epigenetic mechanisms operating in tumoral cells. DNA methylation analyses have identified that the CLL methylome contains imprints of the cell of origin, as well as of the proliferative history of the tumor cells, with both being strong independent prognostic predictors. Moreover, single-cell analysis revealed a higher degree of DNA methylation noise in CLL cells, which associates with transcriptional plasticity and disease aggressiveness. Integrative analysis of chromatin has uncovered chromatin signatures, as well as regulatory regions specifically active in each CLL subtype or in Richter transformed samples. Unique transcription factor (TF) binding motifs are overrepresented on those regions, suggesting that altered TF networks operate from disease initiation to progression as nongenetic factors mediating the oncogenic transcriptional profiles. Multiomics analysis has identified that response to treatment is modulated by an epigenetic imprint, and that treatments affect chromatin through the activity of particular set of TFs. Additionally, the epigenome is an axis of therapeutic vulnerability in CLL, as it can be targeted by inhibitors of histone modifying enzymes, that have shown promising preclinical results. Altogether, this review aims at summarizing the major findings derived from published literature to distill how altered epigenomic mechanisms contribute to CLL origin, evolution, clinical behavior, and response to treatment.
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Affiliation(s)
- Alba Maiques-Diaz
- Fundació de Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi i Sunyer (FRCB-IDIBAPS), Barcelona, Spain
| | - Jose Ignacio Martin-Subero
- Fundació de Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi i Sunyer (FRCB-IDIBAPS), Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain; Departamento de Fundamentos Clínicos, Universitat de Barcelona, Barcelona, Spain.
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3
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Kulis M, Martin-Subero JI. Integrative epigenomics in chronic lymphocytic leukaemia: Biological insights and clinical applications. Br J Haematol 2023; 200:280-290. [PMID: 36121003 DOI: 10.1111/bjh.18465] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/10/2022] [Accepted: 09/05/2022] [Indexed: 01/21/2023]
Abstract
Chronic lymphocytic leukaemia (CLL) is not only characterised by driver genetic alterations but by extensive epigenetic changes. Over the last decade, epigenomic studies have described the DNA methylome, chromatin accessibility, histone modifications and the three-dimensional (3D) genome architecture of CLL. Beyond its regulatory role, the DNA methylome contains imprints of the cellular origin and proliferative history of CLL cells. These two aspects are strong independent prognostic factors. Integrative analyses of chromatin marks have uncovered novel regulatory elements and altered transcription factor networks as non-genetic means mediating gene deregulation in CLL. Additionally, CLL cells display a disease-specific pattern of 3D genome interactions. From the technological perspective, we are currently witnessing a transition from bulk omics to single-cell analyses. This review aims at summarising the major findings from the epigenomics field as well as providing a prospect of the present and future of single-cell analyses in CLL.
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Affiliation(s)
- Marta Kulis
- Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain
| | - Jose Ignacio Martin-Subero
- Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.,Departamento de Fundamentos Clínicos, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Madrid, Spain
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4
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Shen J, Liu J. Bruton's tyrosine kinase inhibitors in the treatment of primary central nervous system lymphoma: A mini-review. Front Oncol 2022; 12:1034668. [PMID: 36465385 PMCID: PMC9713408 DOI: 10.3389/fonc.2022.1034668] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 10/31/2022] [Indexed: 09/19/2023] Open
Abstract
Primary central nervous system lymphoma (PCNSL) is a highly aggressive brain tumor with poor prognosis if no treatment. The activation of the NF-κB (nuclear factor kappa-B) is the oncogenic hallmark of PCNSL, and it was driven by B cell receptor (BCR) and Toll-like receptor (TLR) signaling pathways. The emergence of Bruton's tyrosine kinase inhibitors (BTKis) has brought the dawn of life to patients with PCNSL. This review summarizes the management of PCNSL with BTKis and potential molecular mechanisms of BTKi in the treatment of PCNSL. And the review will focus on the clinical applications of BTKi in the treatment of PCNSL including the efficacy and adverse events, the clinical trials currently being carried out, the underlying mechanisms of resistance to BTKi and possible solutions to drug resistance.
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Affiliation(s)
- Jing Shen
- Department of Hematology, Capital Medical University Affiliated Beijing Friendship Hospital, Beijing, China
| | - Jinghua Liu
- Department of Hematology, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, China
- Department of Hematology, Northern Theater General Hospital, Shenyang, China
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5
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Wang Z, Yan H, Boysen JC, Secreto CR, Tschumper RC, Ali D, Guo Q, Zhong J, Zhou J, Gan H, Yu C, Jelinek DF, Slager SL, Parikh SA, Braggio E, Kay NE. B cell receptor signaling drives APOBEC3 expression via direct enhancer regulation in chronic lymphocytic leukemia B cells. Blood Cancer J 2022; 12:99. [PMID: 35778390 PMCID: PMC9249768 DOI: 10.1038/s41408-022-00690-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 05/18/2022] [Accepted: 06/07/2022] [Indexed: 11/24/2022] Open
Abstract
Constitutively activated B cell receptor (BCR) signaling is a primary biological feature of chronic lymphocytic leukemia (CLL). The biological events controlled by BCR signaling in CLL are not fully understood and need investigation. Here, by analysis of the chromatin states and gene expression profiles of CLL B cells from patients before and after Bruton's tyrosine kinase inhibitor (BTKi) ibrutinib treatment, we show that BTKi treatment leads to a decreased expression of APOBEC3 family genes by regulating the activity of their enhancers. BTKi treatment reduces enrichment of enhancer marks (H3K4me1 and H3K27ac) and chromatin accessibility at putative APOBEC3 enhancers. CRISPR-Cas9 directed deletion or inhibition of the putative APOBEC3 enhancers leads to reduced APOBEC3 expression. We further find that transcription factor NFATc1 couples BCR signaling with the APOBEC3 enhancer activity to control APOBEC3 expression. We also find that enhancer-regulated APOBEC3 expression contributes to replication stress in malignant B cells. In total we demonstrate a novel mechanism for BTKi suppression of APOBEC3 expression via direct enhancer regulation in an NFATc1-dependent manner, implicating BCR signaling as a potential regulator of leukemic genomic instability.
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MESH Headings
- APOBEC Deaminases/biosynthesis
- APOBEC Deaminases/genetics
- APOBEC Deaminases/metabolism
- Chromatin
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/genetics
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Protein Kinase Inhibitors/pharmacology
- Pyrazoles/pharmacology
- Pyrimidines/pharmacology
- Receptors, Antigen, B-Cell/genetics
- Receptors, Antigen, B-Cell/metabolism
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Affiliation(s)
- Zhiquan Wang
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, 55905, USA.
| | - Huihuang Yan
- Division of Computational Biology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Justin C Boysen
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, 55905, USA
| | - Charla R Secreto
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, 55905, USA
| | | | - Dania Ali
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, 55905, USA
| | - Qianqian Guo
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Jian Zhong
- Epigenomics Development Laboratory, Epigenomics Program, Center for Individualized Medicine, Mayo Clinic, Rochester, MN, 55905, USA
| | - Jiaqi Zhou
- Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Haiyun Gan
- Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Chuanhe Yu
- The Hormel Institute, University of Minnesota, Austin, MN, 55912, USA
| | - Diane F Jelinek
- Department of Immunology, Mayo Clinic, Scottsdale, AZ, 85259, USA
| | - Susan L Slager
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, 55905, USA
- Division of Computational Biology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Sameer A Parikh
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, 55905, USA
| | - Esteban Braggio
- Division of Hematology/Oncology, Department of Medicine, Mayo Clinic, Scottsdale, AZ, 85259, USA
| | - Neil E Kay
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, 55905, USA.
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6
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George B, Mullick Chowdhury S, Hart A, Sircar A, Singh SK, Nath UK, Mamgain M, Singhal NK, Sehgal L, Jain N. Ibrutinib Resistance Mechanisms and Treatment Strategies for B-Cell lymphomas. Cancers (Basel) 2020; 12:cancers12051328. [PMID: 32455989 PMCID: PMC7281539 DOI: 10.3390/cancers12051328] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 05/17/2020] [Accepted: 05/19/2020] [Indexed: 02/03/2023] Open
Abstract
Chronic activation of B-cell receptor (BCR) signaling via Bruton tyrosine kinase (BTK) is largely considered to be one of the primary mechanisms driving disease progression in B-Cell lymphomas. Although the BTK-targeting agent ibrutinib has shown promising clinical responses, the presence of primary or acquired resistance is common and often leads to dismal clinical outcomes. Resistance to ibrutinib therapy can be mediated through genetic mutations, up-regulation of alternative survival pathways, or other unknown factors that are not targeted by ibrutinib therapy. Understanding the key determinants, including tumor heterogeneity and rewiring of the molecular networks during disease progression and therapy, will assist exploration of alternative therapeutic strategies. Towards the goal of overcoming ibrutinib resistance, multiple alternative therapeutic agents, including second- and third-generation BTK inhibitors and immunomodulatory drugs, have been discovered and tested in both pre-clinical and clinical settings. Although these agents have shown high response rates alone or in combination with ibrutinib in ibrutinib-treated relapsed/refractory(R/R) lymphoma patients, overall clinical outcomes have not been satisfactory due to drug-associated toxicities and incomplete remission. In this review, we discuss the mechanisms of ibrutinib resistance development in B-cell lymphoma including complexities associated with genomic alterations, non-genetic acquired resistance, cancer stem cells, and the tumor microenvironment. Furthermore, we focus our discussion on more comprehensive views of recent developments in therapeutic strategies to overcome ibrutinib resistance, including novel BTK inhibitors, clinical therapeutic agents, proteolysis-targeting chimeras and immunotherapy regimens.
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Affiliation(s)
- Bhawana George
- Department of Hematopathology, MD Anderson Cancer Center, Houston, TX 77030, USA;
| | - Sayan Mullick Chowdhury
- Department of Internal Medicine, the Ohio State University, Columbus, OH 43210, USA; (S.M.C.); (A.H.); (A.S.); (S.K.S.)
| | - Amber Hart
- Department of Internal Medicine, the Ohio State University, Columbus, OH 43210, USA; (S.M.C.); (A.H.); (A.S.); (S.K.S.)
| | - Anuvrat Sircar
- Department of Internal Medicine, the Ohio State University, Columbus, OH 43210, USA; (S.M.C.); (A.H.); (A.S.); (S.K.S.)
| | - Satish Kumar Singh
- Department of Internal Medicine, the Ohio State University, Columbus, OH 43210, USA; (S.M.C.); (A.H.); (A.S.); (S.K.S.)
| | - Uttam Kumar Nath
- Department of Medical Oncology & Hematology, All India Institute of Medical Sciences, Rishikesh 249203, India;
| | - Mukesh Mamgain
- Department of Biochemistry, All India Institute of Medical Sciences, Rishikesh 249203, India; (M.M.); (N.K.S.)
| | - Naveen Kumar Singhal
- Department of Biochemistry, All India Institute of Medical Sciences, Rishikesh 249203, India; (M.M.); (N.K.S.)
| | - Lalit Sehgal
- Department of Internal Medicine, the Ohio State University, Columbus, OH 43210, USA; (S.M.C.); (A.H.); (A.S.); (S.K.S.)
- Correspondence: (L.S.); (N.J.)
| | - Neeraj Jain
- Department of Medical Oncology & Hematology, All India Institute of Medical Sciences, Rishikesh 249203, India;
- Correspondence: (L.S.); (N.J.)
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7
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Fan Z, Kong M, Li M, Hong W, Fan X, Xu Y. Brahma Related Gene 1 (Brg1) Regulates Cellular Cholesterol Synthesis by Acting as a Co-factor for SREBP2. Front Cell Dev Biol 2020; 8:259. [PMID: 32500071 PMCID: PMC7243037 DOI: 10.3389/fcell.2020.00259] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 03/27/2020] [Indexed: 12/30/2022] Open
Abstract
Hepatocyte is a hub for cholesterol metabolism. Augmented synthesis of cholesterol in the liver is associated with hypercholesterolemia and contributes to the pathogenesis of a host of cardiovascular and metabolic diseases. Sterol response element binding protein 2 (SREBP2) regulates hepatic cholesterol metabolism by activating the transcription of rate-limiting enzymes in the cholesterol biosynthesis pathway. The underlying epigenetic mechanism is not well understood. We report here that mice with hepatocyte-specific knockout (CKO) of Brg1, a chromatin remodeling protein, exhibit reduced levels of hepatic cholesterol compared to the wild type (WT) littermates when placed on a high-fact diet (HFD) or a methionine-and-choline-deficient diet (MCD). Down-regulation of cholesterol levels as a result of BRG1 deficiency was accompanied by attenuation of cholesterogenic gene transcription. Likewise, BRG1 knockdown in hepatocytes markedly suppressed the induction of cholesterogenic genes by lipid depletion formulas. Brg1 interacted with SREBP2 and was recruited by SREBP2 to the cholesterogenic gene promoters. Reciprocally, Brg1 deficiency dampened the occupancies of SREBP2 on target promoters likely through modulating H3K9 methylation on the cholesterogenic gene promoters. Mechanistically, Brg1 recruited the H3K9 methyltransferase KDM3A to co-regulate pro-cholesterogenic transcription. KDM3A silencing dampened the cholesterogenic response in hepatocytes equivalent to Brg1 deficiency. In conclusion, our data demonstrate a novel epigenetic pathway that contributes to SREBP2-dependent cholesterol synthesis in hepatocytes.
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Affiliation(s)
- Zhiwen Fan
- Department of Pathology, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Ming Kong
- Key Laboratory of Targeted Intervention of Cardiovascular Disease and Collaborative Innovation Center for Cardiovascular Translational Medicine, Department of Pathophysiology, Nanjing Medical University, Nanjing, China
| | - Min Li
- Department of Clinical Medicine and Laboratory Center for Experimental Medicine, Jiangsu Health Vocational College, Nanjing, China
| | - Wenxuan Hong
- Key Laboratory of Targeted Intervention of Cardiovascular Disease and Collaborative Innovation Center for Cardiovascular Translational Medicine, Department of Pathophysiology, Nanjing Medical University, Nanjing, China
| | - Xiangshan Fan
- Department of Pathology, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Yong Xu
- Key Laboratory of Targeted Intervention of Cardiovascular Disease and Collaborative Innovation Center for Cardiovascular Translational Medicine, Department of Pathophysiology, Nanjing Medical University, Nanjing, China.,Institute of Biomedical Research, Liaocheng University, Liaocheng, China
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8
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Thomas F, Holmes KB, Kreuz S, Hillmen P, Lefevre PF. DAPK3 participates in the mRNA processing of immediate early genes in chronic lymphocytic leukaemia. Mol Oncol 2020; 14:1268-1281. [PMID: 32306542 PMCID: PMC7266284 DOI: 10.1002/1878-0261.12692] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/24/2020] [Accepted: 03/29/2020] [Indexed: 11/29/2022] Open
Abstract
Cross‐linking of the B‐cell receptor (BCR) induces transcriptional activation of immediate early genes (IEGs) including EGR1 and DUSP2 in chronic lymphocytic leukaemia (CLL). Here, we have shown that this transcriptional activation correlated with histone H3 threonine 6 and 11 phosphorylation. Both transcription and histone post‐translational modifications are repressed by ibrutinib, a small molecule inhibitor used in CLL treatment. Moreover, we have identified the death‐associated protein kinase 3 (DAPK3), as the kinase mediating these histone phosphorylation marks in response to activation of the BCR signalling pathway with this kinase being recruited to RNA polymerase II in an anti‐IgM‐dependent manner. DAPK inhibition mimics ibrutinib‐induced repression of both IEG mRNA and histone H3 phosphorylation and has anti‐proliferative effect comparable to ibrutinib in CLL in vitro. DAPK inhibitor does not repress transcription itself but impacts on mRNA processing and has a broader anti‐tumour effect than ibrutinib, by repressing both anti‐IgM‐ and CD40L‐dependent activation.
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Affiliation(s)
- Fraser Thomas
- Division of Haematology and Immunology, Leeds Institute of Medical Research at St. James's, University of Leeds, UK
| | - Katie B Holmes
- Division of Haematology and Immunology, Leeds Institute of Medical Research at St. James's, University of Leeds, UK
| | - Sarah Kreuz
- Division of Haematology and Immunology, Leeds Institute of Medical Research at St. James's, University of Leeds, UK
| | - Peter Hillmen
- Division of Haematology and Immunology, Leeds Institute of Medical Research at St. James's, University of Leeds, UK
| | - Pascal F Lefevre
- Division of Haematology and Immunology, Leeds Institute of Medical Research at St. James's, University of Leeds, UK
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9
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Xanthopoulos C, Kostareli E. Advances in Epigenetics and Epigenomics in Chronic Lymphocytic Leukemia. CURRENT GENETIC MEDICINE REPORTS 2019. [DOI: 10.1007/s40142-019-00178-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Abstract
Purpose of Review
The development and progression of chronic lymphocytic leukemia (CLL), a highly heterogenous B cell malignancy, are influenced by both genetic and environmental factors. Environmental factors, including pharmacological interventions, can affect the epigenetic landscape of CLL and thereby determine the CLL phenotype, clonal evolution, and clinical outcome. In this review, we critically present the latest advances in the field of CLL epigenomics/epigenetics in order to provide a systematic overview of to-date achievements and highlight the potential of epigenomics approaches in light of novel treatment therapies.
Recent Findings
Recent technological advances have enabled broad and precise mapping of the CLL epigenome. The identification of CLL-specific DNA methylation patterns has allowed for accurate CLL subtype definition, a better understanding of clonal origin and evolution, and the discovery of reliable biomarkers. More recently, studies have started to unravel the prognostic, predictive, and therapeutic potential of mapping chromatin dynamics and histone modifications in CLL. Finally, analysis of non-coding RNA expression has indicated their contribution to disease pathogenesis and helped to define prognostic subsets in CLL.
Summary
Overall, the potential of CLL epigenomics for predicting treatment response and resistance is mounting, especially with the advent of novel targeted CLL therapies.
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10
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Transcriptional Modulation by Idelalisib Synergizes with Bendamustine in Chronic Lymphocytic Leukemia. Cancers (Basel) 2019; 11:cancers11101519. [PMID: 31601046 PMCID: PMC6826782 DOI: 10.3390/cancers11101519] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/19/2019] [Accepted: 10/02/2019] [Indexed: 11/17/2022] Open
Abstract
The phosphatidyl-inositol 3 kinase (PI3K) δ inhibitor, idelalisib (IDE), is a potent inhibitor of the B-cell receptor pathway and a novel and highly effective agent for the treatment of chronic lymphocytic leukemia (CLL). We evaluated the activities of IDE in comparison to bendamusine (BEN), a commonly used alkylating agent, in primary CLL cells ex vivo. In contrast to BEN, IDE was cytotoxic to cells from extensively-treated patients, including those with a deletion (del)17p. Cross-resistance was not observed between BEN and IDE, confirming their different modes of cytotoxicity. Marked synergy was seen between BEN and IDE, even in cases that were resistant to BEN or IDE individually, and those with deletion (del) 17p. CD40L/interleukin 4 (IL4) co-treatment mimicking the CLL microenvironment increased resistance to IDE, but synergy was retained. PI3Kδ-deficient murine splenic B cells were more resistant to IDE and showed reduced synergy with BEN, thus confirming the importance of functional PI3Kδ protein. Although IDE was observed to induce γH2AX, IDE did not enhance activation of the DNA damage response nor DNA repair activity. Interestingly, IDE decreased global RNA synthesis and was antagonistic with 5,6-Dichlorobenzimidazole 1-b-D-ribofuranoside (DRB), an inhibitor of transcription. These findings add to the increasingly complex cellular effects of IDE, and B cell receptor (BCR) inhibitors in general, in CLL.
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