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Carlsen EØ, Lee Y, Magnus P, Jugessur A, Page CM, Nustad HE, Håberg SE, Lie RT, Magnus MC. An examination of mediation by DNA methylation on birthweight differences induced by assisted reproductive technologies. Clin Epigenetics 2022; 14:151. [PMID: 36443807 PMCID: PMC9703677 DOI: 10.1186/s13148-022-01381-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 11/16/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Children born after assisted reproductive technologies (ART) differ in birthweight from those naturally conceived. It has been hypothesized that this might be explained by epigenetic mechanisms. We examined whether cord blood DNA methylation mediated the birthweight difference between 890 newborns conceived by ART (764 by fresh embryo transfer and 126 frozen thawed embryo transfer) and 983 naturally conceived newborns from the Norwegian Mother, Father, and Child Cohort Study (MoBa). DNA methylation was measured by the Illumina Infinium MethylationEPIC array. We conducted mediation analyses to assess whether differentially methylated CpGs mediated the differences in birthweight observed between: (1) fresh embryo transfer and natural conception and (2) frozen and fresh embryo transfer. RESULTS We observed a difference in birthweight between fresh embryo transfer and naturally conceived offspring of - 120 g. 44% (95% confidence interval [CI] 26% to 81%) of this difference in birthweight between fresh embryo transfer and naturally conceived offspring was explained by differences in methylation levels at four CpGs near LOXL1, CDH20, and DRC1. DNA methylation differences at two CpGs near PTGS1 and RASGRP4 jointly mediated 22% (95% CI 8.1% to 50.3%) of the birthweight differences between fresh and frozen embryo transfer. CONCLUSION Our findings suggest that DNA methylation is an important mechanism in explaining birthweight differences according to the mode of conception. Further research should examine how gene regulation at these loci influences fetal growth.
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Affiliation(s)
- Ellen Ø. Carlsen
- grid.418193.60000 0001 1541 4204Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway ,grid.5510.10000 0004 1936 8921Department of Community Medicine, Institute of Health and Society, University of Oslo, Oslo, Norway
| | - Yunsung Lee
- grid.418193.60000 0001 1541 4204Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Per Magnus
- grid.418193.60000 0001 1541 4204Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Astanand Jugessur
- grid.418193.60000 0001 1541 4204Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway ,grid.7914.b0000 0004 1936 7443Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Christian M. Page
- grid.418193.60000 0001 1541 4204Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway ,grid.5510.10000 0004 1936 8921Department of Mathematics, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Haakon E. Nustad
- grid.418193.60000 0001 1541 4204Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway ,Deepinsight, Oslo, Norway
| | - Siri E. Håberg
- grid.418193.60000 0001 1541 4204Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Rolv T. Lie
- grid.418193.60000 0001 1541 4204Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway ,grid.7914.b0000 0004 1936 7443Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Maria C. Magnus
- grid.418193.60000 0001 1541 4204Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
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Huang S, Wang J, Zhang L, Tian S, Wang Y, Shao X, Zhou S, Yu P. Ras guanine nucleotide-releasing protein-4 promotes renal inflammatory injury in type 2 diabetes mellitus. Metabolism 2022; 131:155177. [PMID: 35218794 DOI: 10.1016/j.metabol.2022.155177] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 01/31/2022] [Accepted: 02/18/2022] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Ras guanine nucleotide-releasing protein-4 (RasGRP4) is an activator of Ras protein, which plays significant roles in both the inflammatory response and immune activation. This study determined the role of RasGRP4 in diabetic kidney disease (DKD) progression. METHODS CRISPR/Cas9 technology was used to establish RasGRP4 knockout (KO) mice. Diabetes was induced by a high-fat diet combined with five consecutive daily intraperitoneal injections of streptozotocin (60 mg/kg) in C57BL/6J wild-type (WT) mice and RasGRP4 KO mice. Hematoxylin and eosin, periodic acid-Schiff, and Masson's trichrome staining were used to observe the histology of pathological injury. Immunohistochemical staining was used to analyze inflammatory cell infiltration. Quantitative PCR and Western blotting were used to detect the expression of inflammatory mediators and the activation of signaling pathways in renal tissues. In vitro cell co-culture experiments were performed to explore the interactions between peripheral blood mononuclear cells (PBMCs) and glomerular endothelial cells (GEnCs). RESULTS RasGRP4 KO mice developed less severe diabetic kidney injury compared to WT mice, exhibiting lower proteinuria, reduced CD3+ T lymphocyte and F4/80+ macrophage infiltration, less inflammatory mediator expression including interleukin 6, tumor necrosis alpha, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1, and lower expression levels of critical signal transduction molecules in the NLR family pyrin domain-containing 3 inflammasome and mitogen-activated protein kinase (MAPK)/nuclear factor kappa B (NF-κB) signaling pathways in the diabetic kidney. In vitro experiments showed that the adhesion function of PBMCs of RasGRP4 KO mice was reduced compared to that of WT mice. Moreover, the expression of adhesion molecules and critical signal transduction molecules in the NLRP3 inflammasome and MAPK/NF-κB signaling pathways in GEnCs was stimulated by the supernatant of PBMCs, which were derived from RasGRP4 KO mice treated with high glucose and were also significantly reduced compared to those derived from WT mice. CONCLUSION RasGRP4 promotes the inflammatory injury mediated by PBMCs in diabetes, probably by regulating the interaction between PBMCs and GEnCs and further activating the NLRP3 inflammasome and MAPK/NF-κB signaling pathways.
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Affiliation(s)
- Shuai Huang
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Junmei Wang
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Li Zhang
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Shasha Tian
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Yao Wang
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Xian Shao
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Saijun Zhou
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Pei Yu
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China.
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Heterozygous variants in GATA2 contribute to DCML deficiency in mice by disrupting tandem protein binding. Commun Biol 2022; 5:376. [PMID: 35440757 PMCID: PMC9018821 DOI: 10.1038/s42003-022-03316-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 03/23/2022] [Indexed: 12/11/2022] Open
Abstract
Accumulating lines of clinical evidence support the emerging hypothesis that loss-of-function mutations of GATA2 cause inherited hematopoietic diseases, including Emberger syndrome; dendritic cell, monocyte B and NK lymphoid (DCML) deficiency; and MonoMAC syndrome. Here, we show that mice heterozygous for an arginine-to-tryptophan substitution mutation in GATA2 (G2R398W/+), which was found in a patient with DCML deficiency, substantially phenocopy human DCML deficiency. Mice heterozygous for the GATA2-null mutation (G2-/+) do not show such phenotypes. The G2R398W protein possesses a decreased DNA-binding affinity but obstructs the function of coexpressed wild-type GATA2 through specific cis-regulatory regions, which contain two GATA motifs in direct-repeat arrangements. In contrast, G2R398W is innocuous in mice containing single GATA motifs. We conclude that the dominant-negative effect of mutant GATA2 on wild-type GATA2 through specific enhancer/silencer of GATA2 target genes perturbs the GATA2 transcriptional network, leading to the development of the DCML-like phenotype. The present mouse model provides an avenue for the understanding of molecular mechanisms underlying the pathogenesis of GATA2-related hematopoietic diseases.
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Cooke M, Kazanietz MG. Overarching roles of diacylglycerol signaling in cancer development and antitumor immunity. Sci Signal 2022; 15:eabo0264. [PMID: 35412850 DOI: 10.1126/scisignal.abo0264] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Diacylglycerol (DAG) is a lipid second messenger that is generated in response to extracellular stimuli and channels intracellular signals that affect mammalian cell proliferation, survival, and motility. DAG exerts a myriad of biological functions through protein kinase C (PKC) and other effectors, such as protein kinase D (PKD) isozymes and small GTPase-regulating proteins (such as RasGRPs). Imbalances in the fine-tuned homeostasis between DAG generation by phospholipase C (PLC) enzymes and termination by DAG kinases (DGKs), as well as dysregulation in the activity or abundance of DAG effectors, have been widely associated with tumor initiation, progression, and metastasis. DAG is also a key orchestrator of T cell function and thus plays a major role in tumor immunosurveillance. In addition, DAG pathways shape the tumor ecosystem by arbitrating the complex, dynamic interaction between cancer cells and the immune landscape, hence representing powerful modifiers of immune checkpoint and adoptive T cell-directed immunotherapy. Exploiting the wide spectrum of DAG signals from an integrated perspective could underscore meaningful advances in targeted cancer therapy.
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Affiliation(s)
- Mariana Cooke
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Medicine, Einstein Medical Center Philadelphia, Philadelphia, PA 19141, USA
| | - Marcelo G Kazanietz
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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5
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Benoit A, Bou-Petit E, Chou H, Lu M, Guilbert C, Luo VM, Assouline S, Morin RD, Dmitrienko S, Estrada-Tejedor R, Johnson NA, Mann KK. Mutated RAS-associating proteins and ERK activation in relapse/refractory diffuse large B cell lymphoma. Sci Rep 2022; 12:779. [PMID: 35039569 PMCID: PMC8764096 DOI: 10.1038/s41598-021-04736-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 12/06/2021] [Indexed: 11/16/2022] Open
Abstract
Diffuse large B cell lymphoma (DLBCL) is successfully treated with combination immuno-chemotherapy, but relapse with resistant disease occurs in ~ 40% of patients. However, little is known regarding relapsed/refractory DLBCL (rrDLBCL) genetics and alternative therapies. Based on findings from other tumors, we hypothesized that RAS-MEK-ERK signaling would be upregulated in resistant tumors, potentially correlating with mutations in RAS, RAF, or associated proteins. We analyzed mutations and phospho-ERK levels in tumor samples from rrDLBCL patients. Unlike other tumor types, rrDLBCL is not mutated in any Ras or Raf family members, despite having increased expression of p-ERK. In paired biopsies comparing diagnostic and relapsed specimens, 33% of tumors gained p-ERK expression, suggesting a role in promoting survival. We did find mutations in several Ras-associating proteins, including GEFs, GAPs, and downstream effectors that could account for increased ERK activation. We further investigated mutations in one such protein, RASGRP4. In silico modeling indicated an increased interaction between H-Ras and mutant RASGRP4. In cell lines, mutant RASGRP4 increased basal p-ERK expression and lead to a growth advantage in colony forming assays when challenged with doxorubicin. Relapsed/refractory DLBCL is often associated with increased survival signals downstream of ERK, potentially corresponding with mutations in protein controlling RAS/MEK/ERK signaling.
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Affiliation(s)
- Alexandre Benoit
- Lady Davis Institute, Jewish General Hospital, 3755 Côte Sainte-Catherine Road, Montreal, QC, H3T 1E2, Canada.,Division of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Elisabeth Bou-Petit
- Grup de Química Farmacèutica, IQS School of Engineering, Universitat Ramon Llull, Barcelona, Spain
| | - Hsiang Chou
- Lady Davis Institute, Jewish General Hospital, 3755 Côte Sainte-Catherine Road, Montreal, QC, H3T 1E2, Canada.,Division of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Melissa Lu
- Université de Montréal-Faculté de Médecine, Montreal, Canada
| | - Cynthia Guilbert
- Lady Davis Institute, Jewish General Hospital, 3755 Côte Sainte-Catherine Road, Montreal, QC, H3T 1E2, Canada
| | - Vincent Mingyi Luo
- Lady Davis Institute, Jewish General Hospital, 3755 Côte Sainte-Catherine Road, Montreal, QC, H3T 1E2, Canada.,Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
| | - Sarit Assouline
- Lady Davis Institute, Jewish General Hospital, 3755 Côte Sainte-Catherine Road, Montreal, QC, H3T 1E2, Canada.,Division of Experimental Medicine, McGill University, Montreal, QC, Canada.,Gerald Bronfman Department of Oncology, McGill University, Montreal, QC, Canada
| | - Ryan D Morin
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Svetlana Dmitrienko
- Division of Pathology, McGill University Health Centre, Montreal, QC, Canada
| | - Roger Estrada-Tejedor
- Grup de Química Farmacèutica, IQS School of Engineering, Universitat Ramon Llull, Barcelona, Spain
| | - Nathalie A Johnson
- Lady Davis Institute, Jewish General Hospital, 3755 Côte Sainte-Catherine Road, Montreal, QC, H3T 1E2, Canada.,Division of Experimental Medicine, McGill University, Montreal, QC, Canada.,Gerald Bronfman Department of Oncology, McGill University, Montreal, QC, Canada
| | - Koren K Mann
- Lady Davis Institute, Jewish General Hospital, 3755 Côte Sainte-Catherine Road, Montreal, QC, H3T 1E2, Canada. .,Division of Experimental Medicine, McGill University, Montreal, QC, Canada. .,Gerald Bronfman Department of Oncology, McGill University, Montreal, QC, Canada.
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6
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Regulation of the Small GTPase Ras and Its Relevance to Human Disease. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2021; 2262:19-43. [PMID: 33977469 DOI: 10.1007/978-1-0716-1190-6_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ras research has experienced a considerable boost in recent years, not least prompted by the Ras initiative launched by the NCI in 2013 ( https://www.cancer.gov/research/key-initiatives/ras ), accompanied and conditioned by a strongly reinvigorated determination within the Ras community to develop therapeutics attacking directly the Ras oncoproteins. As a member of the small G-protein superfamily, function and transforming activity of Ras all revolve about its GDP/GTP loading status. For one thing, the extent of GTP loading will determine the proportion of active Ras in the cell, with implications for intensity and quality of downstream signaling. But also the rate of nucleotide exchange, i.e., the Ras-GDP/GTP cycling rate, can have a major impact on Ras function, as illustrated perhaps most impressively by newly discovered fast-cycling oncogenic mutants of the Ras-related GTPase Rac1. Thus, while the last years have witnessed memorable new findings and technical developments in the Ras field, leading to an improved insight into many aspects of Ras biology, they have not jolted at the basics, but rather deepened our view of the fundamental regulatory principles of Ras activity control. In this brief review, we revisit the role and mechanisms of Ras nucleotide loading and its implications for cancer in the light of recent findings.
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7
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Zaballos MA, Acuña-Ruiz A, Morante M, Crespo P, Santisteban P. Regulators of the RAS-ERK pathway as therapeutic targets in thyroid cancer. Endocr Relat Cancer 2019; 26:R319-R344. [PMID: 30978703 DOI: 10.1530/erc-19-0098] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 04/11/2019] [Indexed: 12/30/2022]
Abstract
Thyroid cancer is mostly an ERK-driven carcinoma, as up to 70% of thyroid carcinomas are caused by mutations that activate the RAS/ERK mitogenic signaling pathway. The incidence of thyroid cancer has been steadily increasing for the last four decades; yet, there is still no effective treatment for advanced thyroid carcinomas. Current research efforts are focused on impairing ERK signaling with small-molecule inhibitors, mainly at the level of BRAF and MEK. However, despite initial promising results in animal models, the clinical success of these inhibitors has been limited by the emergence of tumor resistance and relapse. The RAS/ERK pathway is an extremely complex signaling cascade with multiple points of control, offering many potential therapeutic targets: from the modulatory proteins regulating the activation state of RAS proteins to the scaffolding proteins of the pathway that provide spatial specificity to the signals, and finally, the negative feedbacks and phosphatases responsible for inactivating the pathway. The aim of this review is to give an overview of the biology of RAS/ERK regulators in human cancer highlighting relevant information on thyroid cancer and future areas of research.
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Affiliation(s)
- Miguel A Zaballos
- Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto de Salud Carlos III, Madrid, Spain
| | - Adrián Acuña-Ruiz
- Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Morante
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto de Salud Carlos III, Madrid, Spain
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Cantabria, Santander, Spain
| | - Piero Crespo
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto de Salud Carlos III, Madrid, Spain
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Cantabria, Santander, Spain
| | - Pilar Santisteban
- Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Instituto de Salud Carlos III, Madrid, Spain
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Ksionda O, Limnander A, Roose JP. RasGRP Ras guanine nucleotide exchange factors in cancer. FRONTIERS IN BIOLOGY 2013; 8:508-532. [PMID: 24744772 PMCID: PMC3987922 DOI: 10.1007/s11515-013-1276-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
RasGRP proteins are activators of Ras and other related small GTPases by the virtue of functioning as guanine nucleotide exchange factors (GEFs). In vertebrates, four RasGRP family members have been described. RasGRP-1 through -4 share many structural domains but there are also subtle differences between each of the different family members. Whereas SOS RasGEFs are ubiquitously expressed, RasGRP proteins are expressed in distinct patterns, such as in different cells of the hematopoietic system and in the brain. Most studies have concentrated on the role of RasGRP proteins in the development and function of immune cell types because of the predominant RasGRP expression profiles in these cells and the immune phenotypes of mice deficient for Rasgrp genes. However, more recent studies demonstrate that RasGRPs also play an important role in tumorigenesis. Examples are skin- and hematological-cancers but also solid malignancies such as melanoma or prostate cancer. These novel studies bring up many new and unanswered questions related to the molecular mechanism of RasGRP-driven oncogenesis, such as new receptor systems that RasGRP appears to respond to as well as regulatory mechanism for RasGRP expression that appear to be perturbed in these cancers. Here we will review some of the known aspects of RasGRP biology in lymphocytes and will discuss the exciting new notion that RasGRP Ras exchange factors play a role in oncogenesis downstream of various growth factor receptors.
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Affiliation(s)
- Olga Ksionda
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Andre Limnander
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jeroen P. Roose
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
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The shortest isoform of C/EBPβ, liver inhibitory protein (LIP), collaborates with Evi1 to induce AML in a mouse BMT model. Blood 2013; 121:4142-55. [PMID: 23547050 DOI: 10.1182/blood-2011-07-368654] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ecotropic viral integration site 1 (Evi1) is one of the master regulators in the development of acute myeloid leukemia (AML) and myelodysplastic syndrome. High expression of Evi1 is found in 10% of patients with AML and indicates a poor outcome. Several recent studies have indicated that Evi1 requires collaborative factors to induce AML. Therefore, the search for candidate factors that collaborate with Evi1 in leukemogenesis is one of the key issues in uncovering the mechanism of Evi1-related leukemia. Previously, we succeeded in making a mouse model of Evi1-related leukemia using a bone marrow transplantation (BMT) system. In the Evi1-induced leukemic cells, we identified frequent retroviral integrations near the CCAAT/enhancer-binding protein β (C/EBPβ) gene and overexpression of its protein. These findings imply that C/EBPβ is a candidate gene that collaborates with Evi1 in leukemogenesis. Cotransduction of Evi1 and the shortest isoform of C/EBPβ, liver inhibitory protein (LIP), induced AML with short latencies in a mouse BMT model. Overexpression of LIP alone also induced AML with longer latencies. However, excision of all 3 isoforms of C/EBPβ (LAP*/LAP/LIP) did not inhibit the development of Evi1-induced leukemia. Therefore, isoform-specific intervention that targets LIP is required when we consider C/EBPβ as a therapeutic target.
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GPCR activation of Ras and PI3Kc in neutrophils depends on PLCb2/b3 and the RasGEF RasGRP4. EMBO J 2012; 31:3118-29. [PMID: 22728827 PMCID: PMC3400018 DOI: 10.1038/emboj.2012.167] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 05/15/2012] [Indexed: 12/31/2022] Open
Abstract
The molecular mechanisms by which receptors regulate the Ras Binding Domains of the PIP3-generating, class I PI3Ks remain poorly understood, despite their importance in a range of biological settings, including tumorigenesis, activation of neutrophils by pro-inflammatory mediators, chemotaxis of Dictyostelium and cell growth in Drosophila. We provide evidence that G protein-coupled receptors (GPCRs) can stimulate PLCb2/b3 and diacylglycerol- dependent activation of the RasGEF, RasGRP4 in neutrophils. The genetic loss of RasGRP4 phenocopies knock-in of a Ras-insensitive version of PI3Kc in its effects on PI3Kc-dependent PIP3 accumulation, PKB activation, chemokinesis and reactive oxygen species (ROS) formation. These results establish a new mechanism by which GPCRs can stimulate Ras, and the broadly important principle that PLCs can control activation of class I PI3Ks.
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Enomoto Y, Kitaura J, Shimanuki M, Kato N, Nishimura K, Takahashi M, Nakakuma H, Kitamura T, Sonoki T. MicroRNA-125b-1 accelerates a C-terminal mutant of C/EBPα (C/EBPα-C(m))-induced myeloid leukemia. Int J Hematol 2012; 96:334-41. [PMID: 22843432 DOI: 10.1007/s12185-012-1143-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2011] [Revised: 07/02/2012] [Accepted: 07/02/2012] [Indexed: 01/15/2023]
Abstract
MicroRNA-125b-1 (miR-125b-1) is a target of the chromosomal translocations t(11;14)(q24;q32) and t(2;11)(p21;q23), which are found in human B-lymphoid and myeloid malignancies, respectively. These translocations result in overexpression of mature miR-125b, consisting of 22 nucleotides. To analyze the role of miR-125b-1 in leukemogenesis, we created a bone marrow transplantation model using a retrovirus vector containing GFP expression elements. Sole transduction of miR-125b-1 into bone marrow cells resulted in expansion of hematopoietic cells expressing GFP. Compared with cells lacking GFP expression, we observed that GFP(+)/CD11b(+) or GFP(+)/Gr(-)1(+) cells were increased in the bone marrow and spleen. Although previous studies reported sole induction of miR-125b-induced leukemia, we did not find leukemic transformation in our model. Transduction of miR-125b-1 did accelerate myeloid tumors induced by a C-terminal mutant of CAAT-enhancer binding protein (C/EBPα-C(m)), a class II-like mutation. As miR-125b has been shown to hasten the development of leukemia in a BCR/ABL-transduced animal model, our present results support the conclusion that overexpression of miR-125b cooperates with other genetic alterations in the pathogenesis of myeloid malignancies.
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Affiliation(s)
- Yutaka Enomoto
- Division of Cellular Therapy, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
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Aberrant expression of RasGRP1 cooperates with gain-of-function NOTCH1 mutations in T-cell leukemogenesis. Leukemia 2011; 26:1038-45. [PMID: 22116551 DOI: 10.1038/leu.2011.328] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Ras guanyl nucleotide-releasing proteins (RasGRPs) are activators of Ras. Previous studies have indicated the possible involvement of RasGRP1 and RasGRP4 in leukemogenesis. Here, the predominant role of RasGRP1 in T-cell leukemogenesis is clarified. Notably, increased expression of RasGRP1, but not RasGRP4, was frequently observed in human T-cell malignancies. In a mouse bone marrow transplantation model, RasGRP1 exclusively induced T-cell acute lymphoblastic leukemia/lymphoma (T-ALL) after a shorter latency when compared with RasGRP4. Accordingly, Ba/F3 cells transduced with RasGRP1 survived longer under growth factor withdrawal or phorbol ester stimulation than those transduced with RasGRP4, presumably due to the efficient activation of Ras. Intriguingly, NOTCH1 mutations resulting in a gain of function were found in 77% of the RasGRP1-mediated mouse T-ALL samples. In addition, gain-of-function NOTCH1 mutation was found in human T-cell malignancy with elevated expression of RasGRP1. Importantly, RasGRP1 and NOTCH1 signaling cooperated in the progression of T-ALL in the murine model. The leukemogenic advantage of RasGRP1 over RasGRP4 was attenuated by the disruption of a protein kinase C phosphorylation site (RasGRP1(Thr184)) not present on RasGRP4. In conclusion, cooperation between aberrant expression of RasGRP1, a strong activator of Ras, and secondary gain-of-function mutations of NOTCH1 have an important role in T-cell leukemogenesis.
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Abstract
Ras guanyl nucleotide releasing proteins (RasGRPs) are guanyl nucleotide exchange factors that activate Ras and related GTPases such as Rap. Like Sos proteins, RasGRPs have a catalytic region composed of a Ras exchange motif (REM) and a CDC25 domain. RasGRPs also possess a pair of atypical EF hands that may bind calcium in vivo and a C1 domain resembling the diacylglycerol (DAG)-binding domain of protein kinase C. DAG directly activates RasGRPs by a membrane recruitment mechanism as well as indirectly by PKC-mediated phosphorylation. RasGRPs are prominently expressed in blood cells. RasGRP1 acts downstream of TCR, while RasGRP1 and RasGRP3 both act downstream of BCR. Together, they regulate Ras in adaptive immune cells. RasGRP2, through Rap, plays a role in controlling platelet adhesion, while RasGRP4 controls Ras activation in mast cells. RasGRP malfunction likely contributes to autoimmunity and may contribute to blood malignancies. RasGRPs might prove to be viable drug targets. The intracellular site of RasGRP action and the relationship between RasGRPs and other Ras regulatory mechanisms are subjects of lively debate.
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Affiliation(s)
- James C Stone
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
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14
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Mutations in the transmembrane and juxtamembrane domains enhance IL27R transforming activity. Biochem J 2011; 438:155-64. [PMID: 21631431 DOI: 10.1042/bj20110351] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cytokines and their receptors regulate haemopoiesis by controlling cellular growth, survival and differentiation. Thus it is not surprising that mutations of cytokine receptors contribute to the formation of haemopoietic disorders, including cancer. We recently identified transforming properties of IL27R, the ligand-binding component of the receptor for interleukin-27. Although wild-type IL27R exhibits transforming properties in haemopoietic cells, in the present study we set out to determine if the transforming activity of IL27R could be enhanced by mutation. We identified three mutations of IL27R that enhance its transforming activity. One of these mutations is a phenylalanine to cysteine mutation at residue 523 (F523C) in the transmembrane domain of the receptor. The two other mutations identified involve deletions of amino acids in the cytoplasmic juxtamembrane region of the receptor. Expression of each of these mutant IL27R proteins led to rapid cytokine-independent transformation in haemopoietic cells. Moreover, the rate of transformation induced by these mutants was significantly greater than that induced by wild-type IL27R. Expression of these IL27R mutants also induced enhanced activation of JAK (Janus kinase)/STAT (signal transducer and activator of transcription) signalling compared with wild-type. An activating deletion mutation of IL27R enhanced homodimerization of the receptor by a mechanism that may involve disulfide bonding. These transforming IL27R mutants displayed equal or greater transforming activity than bona fide haemopoietic oncogenes such as BCR-ABL (breakpoint cluster region-Abelson murine leukaemia viral oncogene homologue) and JAK2-V617F. Since IL27R is expressed on haemopoietic stem cells, lymphoid cells and myeloid cells, including acute myeloid leukaemia blast cells, mutation of this receptor has the potential to contribute to a variety of haemopoietic neoplasms.
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15
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Enomoto Y, Kitaura J, Hatakeyama K, Watanuki J, Akasaka T, Kato N, Shimanuki M, Nishimura K, Takahashi M, Taniwaki M, Haferlach C, Siebert R, Dyer MJS, Asou N, Aburatani H, Nakakuma H, Kitamura T, Sonoki T. Eμ/miR-125b transgenic mice develop lethal B-cell malignancies. Leukemia 2011; 25:1849-56. [DOI: 10.1038/leu.2011.166] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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16
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Dowdy CR, Xie R, Frederick D, Hussain S, Zaidi SK, Vradii D, Javed A, Li X, Jones SN, Lian JB, van Wijnen AJ, Stein JL, Stein GS. Definitive hematopoiesis requires Runx1 C-terminal-mediated subnuclear targeting and transactivation. Hum Mol Genet 2009; 19:1048-57. [PMID: 20035012 DOI: 10.1093/hmg/ddp568] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Runx1 is a key hematopoietic transcription factor required for definitive hematopoiesis and is a frequent target of leukemia-related chromosomal translocations. The resulting fusion proteins, while retaining DNA binding activity, display loss of subnuclear targeting and associated transactivation functions encoded by the C-terminus of the protein. To define the precise contribution of the Runx1 C-terminus in development and leukemia, we created a knock-in mouse with a C-terminal truncation by introducing a single nucleic acid substitution in the native Runx1 locus. This mutation (Runx1(Q307X)) models genetic lesions observed in patients with leukemia and myeloproliferative disorders. The Runx1(Q307X) homozygous mouse exhibits embryonic lethality at E12.5 due to central nervous system hemorrhages and a complete lack of hematopoietic stem cell function. While able to bind DNA, Runx1(Q307X) is unable to activate target genes, resulting in deregulation of various hematopoietic markers. Thus, we demonstrate that the subnuclear targeting and transcriptional regulatory activities of the Runx1 C-terminus are critical for hematopoietic development. We propose that compromising the C-terminal functions of Runx1 is a common mechanism for the pathological consequences of a variety of somatic mutations and Runx1-related leukemic fusion proteins observed in human patients.
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Affiliation(s)
- Christopher R Dowdy
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, Worcester, MA 01655, USA
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