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Rechberger JS, Toll SA, Vanbilloen WJF, Daniels DJ, Khatua S. Exploring the Molecular Complexity of Medulloblastoma: Implications for Diagnosis and Treatment. Diagnostics (Basel) 2023; 13:2398. [PMID: 37510143 PMCID: PMC10378552 DOI: 10.3390/diagnostics13142398] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/07/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
Medulloblastoma is the most common malignant brain tumor in children. Over the last few decades, significant progress has been made in revealing the key molecular underpinnings of this disease, leading to the identification of distinct molecular subgroups with different clinical outcomes. In this review, we provide an update on the molecular landscape of medulloblastoma and treatment strategies. We discuss the four main molecular subgroups (WNT-activated, SHH-activated, and non-WNT/non-SHH groups 3 and 4), highlighting the key genetic alterations and signaling pathways associated with each entity. Furthermore, we explore the emerging role of epigenetic regulation in medulloblastoma and the mechanism of resistance to therapy. We also delve into the latest developments in targeted therapies and immunotherapies. Continuing collaborative efforts are needed to further unravel the complex molecular mechanisms and profile optimal treatment for this devastating disease.
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Affiliation(s)
- Julian S Rechberger
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Stephanie A Toll
- Department of Pediatrics, Division of Hematology/Oncology, Children's Hospital of Michigan, Detroit, MI 48201, USA
| | - Wouter J F Vanbilloen
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA
- Department of Neurology, Elisabeth-Tweesteden Hospital, 5022 Tilburg, The Netherlands
| | - David J Daniels
- Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Soumen Khatua
- Department of Pediatric Hematology/Oncology, Section of Neuro-Oncology, Mayo Clinic, Rochester, MN 55905, USA
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2
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Shalom B, Salaymeh Y, Risling M, Katzav S. Unraveling the Oncogenic Potential of VAV1 in Human Cancer: Lessons from Mouse Models. Cells 2023; 12:cells12091276. [PMID: 37174676 PMCID: PMC10177506 DOI: 10.3390/cells12091276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/23/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
VAV1 is a hematopoietic signal transducer that possesses a GDP/GTP nucleotide exchange factor (GEF) that is tightly regulated by tyrosine phosphorylation, along with adapter protein domains, such as SH2 and SH3. Research on VAV1 has advanced over the years since its discovery as an in vitro activated oncogene in an NIH3T3 screen for oncogenes. Although the oncogenic form of VAV1 first identified in the screen has not been detected in human clinical tumors, its wild-type and mutant forms have been implicated in mammalian malignancies of various tissue origins, as well as those of the hematopoietic system. This review article addresses the activity of human VAV1 as an overexpressed or mutated gene and also describes the differences in the distribution of VAV1 mutations in the hematopoietic system and in other tissues. The knowledge accumulated thus far from GEMMs expressing VAV1 is described, with the conclusion that GEMMs of both wild-type VAV1 and mutant VAV1 do not form tumors, yet these will be generated when additional molecular insults, such as loss of p53 or KRAS mutation, occur.
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Affiliation(s)
- Batel Shalom
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University, Jerusalem 91120, Israel
| | - Yaser Salaymeh
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University, Jerusalem 91120, Israel
| | - Matan Risling
- Department of Military Medicine and "Tzameret", Faculty of Medicine, Hebrew University, Jerusalem 91120, Israel
- Medical Corps, Israel Defense Forces, Tel-Hashomer 02149, Israel
| | - Shulamit Katzav
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University, Jerusalem 91120, Israel
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3
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Gorini F, Miceli M, de Antonellis P, Amente S, Zollo M, Ferrucci V. Epigenetics and immune cells in medulloblastoma. Front Genet 2023; 14:1135404. [PMID: 36968588 PMCID: PMC10036437 DOI: 10.3389/fgene.2023.1135404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 02/27/2023] [Indexed: 03/12/2023] Open
Abstract
Medulloblastoma (MB) is a highly malignant childhood tumor of the cerebellum. Transcriptional and epigenetic signatures have classified MB into four molecular subgroups, further stratified into biologically different subtypes with distinct somatic copy-number aberrations, driver genes, epigenetic alterations, activated pathways, and clinical outcomes. The brain tumor microenvironment (BTME) is of importance to regulate a complex network of cells, including immune cells, involved in cancer progression in brain malignancies. MB was considered with a “cold” immunophenotype due to the low influx of immune cells across the blood brain barrier (BBB). Recently, this assumption has been reconsidered because of the identification of infiltrating immune cells showing immunosuppressive phenotypes in the BTME of MB tumors. Here, we are providing a comprehensive overview of the current status of epigenetics alterations occurring during cancer progression with a description of the genomic landscape of MB by focusing on immune cells within the BTME. We further describe how new immunotherapeutic approaches could influence concurring epigenetic mechanisms of the immunosuppressive cells in BTME. In conclusion, the modulation of these molecular genetic complexes in BTME during cancer progression might enhance the therapeutic benefit, thus firing new weapons to fight MB.
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Affiliation(s)
- Francesca Gorini
- Department of Molecular Medicine and Medical Biotechnology (DMMBM), University of Naples, Naples, Italy
| | - Marco Miceli
- CEINGE Biotecnologie Avanzate “Franco Salvatore”, Naples, Italy
| | - Pasqualino de Antonellis
- Department of Molecular Medicine and Medical Biotechnology (DMMBM), University of Naples, Naples, Italy
| | - Stefano Amente
- Department of Molecular Medicine and Medical Biotechnology (DMMBM), University of Naples, Naples, Italy
| | - Massimo Zollo
- Department of Molecular Medicine and Medical Biotechnology (DMMBM), University of Naples, Naples, Italy
- CEINGE Biotecnologie Avanzate “Franco Salvatore”, Naples, Italy
- DAI Medicina di Laboratorio e Trasfusionale, ‘AOU Federico II Policlinico, Naples, Italy
| | - Veronica Ferrucci
- Department of Molecular Medicine and Medical Biotechnology (DMMBM), University of Naples, Naples, Italy
- CEINGE Biotecnologie Avanzate “Franco Salvatore”, Naples, Italy
- *Correspondence: Veronica Ferrucci,
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4
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Vav1 accelerates Ras-driven lung cancer and modulates its tumor microenvironment. Cell Signal 2022; 97:110395. [PMID: 35752351 DOI: 10.1016/j.cellsig.2022.110395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/13/2022] [Accepted: 06/20/2022] [Indexed: 11/23/2022]
Abstract
The potential impact of Vav1 on human cancer was only recently acknowledged, as it is detected as a mutant or an overexpressed gene in various cancers, including lung cancer. Vav1, which is normally and exclusively expressed in the hematopoietic system functions as a specific GDP/GTP nucleotide exchange factor (GEF), strictly regulated by tyrosine phosphorylation. To investigate whether Vav1 plays a causative or facilitating role in-vivo in lung cancer development and to examine whether it co-operates with other oncogenes, such as mutant K-Ras, we generated novel mouse strains that express: Vav1 or K-RasG12D in type II pneumocytes, as well as a transgenic mouse line that expresses both Vav1 and K-RasG12D in these cells. Coexpression of Vav1 and K-RasG12D in the lungs dramatically increased malignant lung cancer lesions, and did so significantly faster than K-RasG12D alone, strongly suggesting that these two oncogenes synergize to enhance lung tumor development. Vav1 expression alone had no apparent effects on lung tumorigenesis. The increase in lung cancer in K-RasG12D/Vav1 mice was accompanied by an increase in B-cell, T-cells, and monocyte infiltration in the tumor microenvironment. Concomitantly, ERK phosphorylation was highly elevated in the lungs of K-RasG12 D/Vav1 mice. Also, several cytokines such as IL-4 and IL-13 which play a significant role in the immune system, were elevated in lungs of Vav1 and K-RasG12 D/Vav1 mice. Our findings emphasize the contribution of Vav1 to lung tumor development through its signaling properties.
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5
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Vav1 Promotes B-Cell Lymphoma Development. Cells 2022; 11:cells11060949. [PMID: 35326399 PMCID: PMC8946024 DOI: 10.3390/cells11060949] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 03/06/2022] [Accepted: 03/08/2022] [Indexed: 02/07/2023] Open
Abstract
Vav1 is normally and exclusively expressed in the hematopoietic system where it functions as a specific GDP/GTP nucleotide exchange factor (GEF), firmly regulated by tyrosine phosphorylation. Mutations and overexpression of Vav1 in hematopoietic malignancies, and in human cancers of various histologic origins, are well documented. To reveal whether overexpression of Vav1 in different tissues suffices for promoting the development of malignant lesions, we expressed Vav1 in transgenic mice by using the ubiquitous ROSA26 promoter (Rosa Vav1). We detected Vav1 expression in epithelial tissues of various organs including pancreas, liver, and lung. While carcinomas did not develop in these organs, surprisingly, we noticed the development of B-cell lymphomas. Rac1-GTP levels did not change in tissues from Rosa Vav1 mice expressing the transgenic Vav1, while ERK phosphorylation increased in the lymphomas, suggesting that signaling pathways are evoked. One of the growth factors analyzed by us as a suspect candidate to mediate paracrine stimulation in the lymphocytes was CSF-1, which was highly expressed in the epithelial compartment of Rosa Vav1 mice. The expression of its specific receptor, CSF-1R, was found to be highly expressed in the B-cell lymphomas. Taken together, our results suggest a potential cross-talk between epithelial cells expressing Vav1, that secrete CSF-1, and the lymphocytes that express CSF-1R, thus leading to the generation of B-cell lymphomas. Our findings provide a novel mechanism by which Vav1 contributes to tumor propagation.
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6
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Boudria R, Laurienté V, Oudar A, Harouna-Rachidi S, Dondi E, Le Roy C, Gardano L, Varin-Blank N, Guittat L. Regulatory interplay between Vav1, Syk and β-catenin occurs in lung cancer cells. Cell Signal 2021; 86:110079. [PMID: 34252536 DOI: 10.1016/j.cellsig.2021.110079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 06/30/2021] [Accepted: 07/05/2021] [Indexed: 01/15/2023]
Abstract
Vav1 exhibits two signal transducing properties as an adaptor protein and a regulator of cytoskeleton organization through its Guanine nucleotide Exchange Factor module. Although the expression of Vav1 is restricted to the hematopoietic lineage, its ectopic expression has been unraveled in a number of solid tumors. In this study, we show that in lung cancer cells, as such in hematopoietic cells, Vav1 interacts with the Spleen Tyrosine Kinase, Syk. Likewise, Syk interacts with β-catenin and, together with Vav1, regulates the phosphorylation status of β-catenin. Depletion of Vav1, Syk or β-catenin inhibits Rac1 activity and decreases cell migration suggesting the interplay of the three effectors to a common signaling pathway. This model is further supported by the finding that in turn, β-catenin regulates the transcription of Syk gene expression. This study highlights the elaborated connection between Vav1, Syk and β-catenin and the contribution of the trio to cell migration.
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Affiliation(s)
- Rofia Boudria
- INSERM, UMR 978, Bobigny, France; Labex Inflamex, Université Sorbonne Paris Nord, UFR SMBH, Bobigny, France
| | - Vanessa Laurienté
- INSERM, UMR 978, Bobigny, France; Labex Inflamex, Université Sorbonne Paris Nord, UFR SMBH, Bobigny, France
| | - Antonin Oudar
- INSERM, UMR 978, Bobigny, France; Labex Inflamex, Université Sorbonne Paris Nord, UFR SMBH, Bobigny, France
| | - Souleymane Harouna-Rachidi
- INSERM, UMR 978, Bobigny, France; Labex Inflamex, Université Sorbonne Paris Nord, UFR SMBH, Bobigny, France
| | - Elisabetta Dondi
- INSERM, UMR 978, Bobigny, France; Labex Inflamex, Université Sorbonne Paris Nord, UFR SMBH, Bobigny, France
| | - Christine Le Roy
- INSERM, UMR 978, Bobigny, France; Labex Inflamex, Université Sorbonne Paris Nord, UFR SMBH, Bobigny, France
| | - Laura Gardano
- INSERM, UMR 978, Bobigny, France; Labex Inflamex, Université Sorbonne Paris Nord, UFR SMBH, Bobigny, France
| | - Nadine Varin-Blank
- INSERM, UMR 978, Bobigny, France; Labex Inflamex, Université Sorbonne Paris Nord, UFR SMBH, Bobigny, France.
| | - Lionel Guittat
- INSERM, UMR 978, Bobigny, France; Labex Inflamex, Université Sorbonne Paris Nord, UFR SMBH, Bobigny, France.
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7
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Salaymeh Y, Farago M, Sebban S, Shalom B, Pikarsky E, Katzav S. Vav1 and mutant K-Ras synergize in the early development of pancreatic ductal adenocarcinoma in mice. Life Sci Alliance 2020; 3:e202000661. [PMID: 32277014 PMCID: PMC7156281 DOI: 10.26508/lsa.202000661] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/20/2020] [Accepted: 03/23/2020] [Indexed: 02/06/2023] Open
Abstract
To explore the contribution of Vav1, a hematopoietic signal transducer, to pancreatic ductal adenocarcinoma (PDAC) development, we generated transgenic mouse lines expressing, Vav1, K-RasG12D, or both K-RasG12D and Vav1 in pancreatic acinar cells. Co-expression of Vav1 and K-RasG12D synergistically enhanced acinar-to-ductal metaplasia (ADM) formation, far exceeding the number of lesions developed in K-RasG12D mice. Mice expressing only Vav1 did not develop ADM. Moreover, the incidence of PDAC in K-RasG12D/Vav1 was significantly higher than in K-RasG12D mice. Discontinuing Vav1 expression in K-RasG12D/Vav1 mice elicited a marked regression of malignant lesions in the pancreas, demonstrating Vav1 is required for generation and maintenance of ADM. Rac1-GTP levels in the K-RasG12D/Vav1 mice pancreas clearly demonstrated an increase in Rac1 activity. Treatment of K-RasG12D and K-RasG12D/Vav1 mice with azathioprine, an immune-suppressor drug which inhibits Vav1's activity as a GDP/GTP exchange factor, dramatically reduced the number of malignant lesions. These results suggest that Vav1 plays a role in the development of PDAC when co-expressed with K-RasG12D via its activity as a GEF for Rac1GTPase.
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Affiliation(s)
- Yaser Salaymeh
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Marganit Farago
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Shulamit Sebban
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Batel Shalom
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Eli Pikarsky
- The Lautenberg Center for Immunology and Cancer Research and Department of Pathology, Institute for Medical Research Israel-Canada, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Shulamit Katzav
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University Hadassah Medical School, Jerusalem, Israel
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8
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Maldonado MDM, Medina JI, Velazquez L, Dharmawardhane S. Targeting Rac and Cdc42 GEFs in Metastatic Cancer. Front Cell Dev Biol 2020; 8:201. [PMID: 32322580 PMCID: PMC7156542 DOI: 10.3389/fcell.2020.00201] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 03/09/2020] [Indexed: 12/20/2022] Open
Abstract
The Rho family GTPases Rho, Rac, and Cdc42 have emerged as key players in cancer metastasis, due to their essential roles in regulating cell division and actin cytoskeletal rearrangements; and thus, cell growth, migration/invasion, polarity, and adhesion. This review will focus on the close homologs Rac and Cdc42, which have been established as drivers of metastasis and therapy resistance in multiple cancer types. Rac and Cdc42 are often dysregulated in cancer due to hyperactivation by guanine nucleotide exchange factors (GEFs), belonging to both the diffuse B-cell lymphoma (Dbl) and dedicator of cytokinesis (DOCK) families. Rac/Cdc42 GEFs are activated by a myriad of oncogenic cell surface receptors, such as growth factor receptors, G-protein coupled receptors, cytokine receptors, and integrins; consequently, a number of Rac/Cdc42 GEFs have been implicated in metastatic cancer. Hence, inhibiting GEF-mediated Rac/Cdc42 activation represents a promising strategy for targeted metastatic cancer therapy. Herein, we focus on the role of oncogenic Rac/Cdc42 GEFs and discuss the recent advancements in the development of Rac and Cdc42 GEF-interacting inhibitors as targeted therapy for metastatic cancer, as well as their potential for overcoming cancer therapy resistance.
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Affiliation(s)
- Maria Del Mar Maldonado
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Julia Isabel Medina
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Luis Velazquez
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
| | - Suranganie Dharmawardhane
- Department of Biochemistry, School of Medicine, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
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9
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Dobson THW, Tao RH, Swaminathan J, Maegawa S, Shaik S, Bravo-Alegria J, Sharma A, Kennis B, Yang Y, Callegari K, Haltom AR, Taylor P, Kogiso M, Qi L, Khatua S, Goldman S, Lulla RR, Fangusaro J, MacDonald TJ, Li XN, Hawkins C, Rajaram V, Gopalakrishnan V. Transcriptional repressor REST drives lineage stage-specific chromatin compaction at Ptch1 and increases AKT activation in a mouse model of medulloblastoma. Sci Signal 2019; 12:12/565/eaan8680. [PMID: 30670636 DOI: 10.1126/scisignal.aan8680] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In medulloblastomas (MBs), the expression and activity of RE1-silencing transcription factor (REST) is increased in tumors driven by the sonic hedgehog (SHH) pathway, specifically the SHH-α (children 3 to 16 years) and SHH-β (infants) subgroups. Neuronal maturation is greater in SHH-β than SHH-α tumors, but both correlate with poor overall patient survival. We studied the contribution of REST to MB using a transgenic mouse model (RESTTG ) wherein conditional NeuroD2-controlled REST transgene expression in lineage-committed Ptch1 +/- cerebellar granule neuron progenitors (CGNPs) accelerated tumorigenesis and increased penetrance and infiltrative disease. This model revealed a neuronal maturation context-specific antagonistic interplay between the transcriptional repressor REST and the activator GLI1 at Ptch1 Expression of Arrb1, which encodes β-arrestin1 (a GLI1 inhibitor), was substantially reduced in proliferating and, to a lesser extent, lineage-committed RESTTG cells compared with wild-type proliferating CGNPs. Lineage-committed RESTTG cells also had decreased GLI1 activity and increased histone H3K9 methylation at the Ptch1 locus, which correlated with premature silencing of Ptch1 These cells also had decreased expression of Pten, which encodes a negative regulator of the kinase AKT. Expression of PTCH1 and GLI1 were less, and ARRB1 was somewhat greater, in patient SHH-β than SHH-α MBs, whereas that of PTEN was similarly lower in both subtypes than in others. Inhibition of histone modifiers or AKT reduced proliferation and induced apoptosis, respectively, in cultured REST-high MB cells. Our findings linking REST to differentiation-specific chromatin remodeling, PTCH1 silencing, and AKT activation in MB tissues reveal potential subgroup-specific therapeutic targets for MB patients.
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Affiliation(s)
- Tara H W Dobson
- Department of Pediatrics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Rong-Hua Tao
- Department of Pediatrics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
| | | | - Shinji Maegawa
- Department of Pediatrics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Shavali Shaik
- Department of Pediatrics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Javiera Bravo-Alegria
- Department of Pediatrics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Ajay Sharma
- Department of Pediatrics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Bridget Kennis
- Department of Pediatrics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Yanwen Yang
- Department of Pediatrics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Keri Callegari
- Department of Pediatrics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Amanda R Haltom
- Department of Pediatrics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Pete Taylor
- Department of Pediatrics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Mari Kogiso
- Texas Children's Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lin Qi
- Texas Children's Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Soumen Khatua
- Department of Pediatrics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Stewart Goldman
- Department of Pediatrics, Northwestern University, Chicago, IL 60611, USA
| | - Rishi R Lulla
- Department of Pediatrics, Northwestern University, Chicago, IL 60611, USA
| | - Jason Fangusaro
- Department of Pediatrics, Northwestern University, Chicago, IL 60611, USA
| | | | - Xiao-Nan Li
- Texas Children's Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA.,Department of Pediatrics, Northwestern University, Chicago, IL 60611, USA
| | - Cynthia Hawkins
- Department of Pathology, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Veena Rajaram
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Vidya Gopalakrishnan
- Department of Pediatrics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA. .,Molecular and Cellular Oncology, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA.,Brain Tumor Center, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA.,Center for Cancer Epigenetics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA.,The University of Texas MD Anderson Cancer Center-University of Texas Health Science Center at Houston Graduate School of Biomedical Sciences, Houston, TX 77030, USA
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10
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Vav1 mutations identified in human cancers give rise to different oncogenic phenotypes. Oncogenesis 2018; 7:80. [PMID: 30297765 PMCID: PMC6175932 DOI: 10.1038/s41389-018-0091-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/27/2018] [Accepted: 09/09/2018] [Indexed: 01/26/2023] Open
Abstract
Vav1 is physiologically active as a GDP/GTP nucleotide exchange factor (GEF) in the hematopoietic system. Overexpression of Vav1 in multiple tumor types is known to enhance oncogenicity, yet whether or not Vav1 is a bona fide oncogene is still a matter of debate. Although mutations in Vav1 were recently identified in human cancers of various origins, the functional activities of these mutants are not known. We tested the transforming potential of three mutations identified in human lung adenocarcinoma: E59K, D517E, and L801P. Results from several assays indicative of transforming activities such as rate of proliferation, growth in agar, and generation of tumors in NOD/SCID mice clearly indicated that E59K and D517E are highly transforming but L801P at the SH3 domain is not. The acquired oncogenic activity of these mutants can be attributed to their enhanced activity as GEFs for Rho/Rac GTPases. Deciphering of the mechanisms leading to overactivity of the tested mutants revealed that the E59K mutation facilitates cleavage of a truncated protein that is uncontrollably active as a GEF, while D517E generates a highly stable overexpressed protein that is also more active as a GEF than wild-type Vav1. These findings support the classification of Vav1 as a bona fide oncogene in human cancer.
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11
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Yi J, Wu J. Epigenetic regulation in medulloblastoma. Mol Cell Neurosci 2017; 87:65-76. [PMID: 29269116 DOI: 10.1016/j.mcn.2017.09.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 09/08/2017] [Accepted: 09/10/2017] [Indexed: 12/14/2022] Open
Abstract
Medulloblastoma is the most common malignant childhood brain tumor. The heterogeneous tumors are classified into four subgroups based on transcription profiles. Recent developments in genome-wide sequencing techniques have rapidly advanced the understanding of these tumors. The high percentages of somatic alterations of genes encoding chromatin regulators in all subgroups suggest that epigenetic deregulation is a major driver of medulloblastoma. In this report, we review the current understanding of epigenetic regulation in medulloblastoma with a focus on the functional studies of chromatin regulators in the initiation and progression of specific subgroups of medulloblastoma. We also discuss the potential usage of epigenetic inhibitors for medulloblastoma treatment.
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Affiliation(s)
- Jiaqing Yi
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA
| | - Jiang Wu
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA.
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12
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TGFβ promotes mesenchymal phenotype of pancreatic cancer cells, in part, through epigenetic activation of VAV1. Oncogene 2016; 36:2202-2214. [PMID: 27893715 DOI: 10.1038/onc.2016.378] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/14/2016] [Accepted: 08/29/2016] [Indexed: 02/06/2023]
Abstract
The highly homeostasis-resistant nature of cancer cells leads to their escape from treatment and to liver metastasis, which in turn makes pancreatic ductal adenocarcinoma (PDAC) difficult to treat, especially the squamous/epithelial-to-mesenchymal transition (EMT)-like subtype. As the molecular mechanisms underlying tumour heterogeneity remain elusive, we investigated whether epigenetic regulation might explain inter-individual differences in the progression of specific subtypes. DNA methylation profiling performed on cancer tissues prior to chemo/radiotherapy identified one hypermethylated CpG site (CpG6882469) in the VAV1 gene body that was correlated with demethylation of two promoter CpGs (CpG6772370/CpG6772811) in both PDAC and peripheral blood. Transforming growth factor β treatment induced gene-body hypermethylation, dissociation of DNMT1 from the promoter, and VAV1 expression via SMAD4 and mutant KrasG12D. Pharmacological inhibition of TGFβ-VAV1 signalling decreased the squamous/EMT-like cancer cells, promoted nuclear VAV1 localization, and enhanced the efficacy of gemcitabine in prolonging the survival of KPfl/flC mice. Together, the three VAV1 CpGs serve as biomarkers for prognosis and early detection, and the TGFβ-VAV1 axis represents a therapeutic target.
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Vav1: A Dr. Jekyll and Mr. Hyde protein--good for the hematopoietic system, bad for cancer. Oncotarget 2016; 6:28731-42. [PMID: 26353933 PMCID: PMC4745688 DOI: 10.18632/oncotarget.5086] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 08/07/2015] [Indexed: 01/10/2023] Open
Abstract
Many deregulated signal transducer proteins are involved in various cancers at numerous stages of tumor development. One of these, Vav1, is normally expressed exclusively in the hematopoietic system, where it functions as a specific GDP/GTP nucleotide exchange factor (GEF), strictly regulated by tyrosine phosphorylation. Vav was first identified in an NIH3T3 screen for oncogenes. Although the oncogenic form of Vav1 identified in the screen has not been detected in clinical human tumors, its wild-type form has recently been implicated in mammalian malignancies, including neuroblastoma, melanoma, pancreatic, lung and breast cancers, and B-cell chronic lymphocytic leukemia. In addition, it was recently identified as a mutated gene in human cancers of various origins. However, the activity and contribution to cancer of these Vav1 mutants is still unclear. This review addresses the physiological function of wild-type Vav1 and its activity as an oncogene in human cancer. It also discusses the novel mutations identified in Vav1 in various cancers and their potential contribution to cancer development as oncogenes or tumor suppressor genes.
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Kessler NJ, Van Baak TE, Baker MS, Laritsky E, Coarfa C, Waterland RA. CpG methylation differences between neurons and glia are highly conserved from mouse to human. Hum Mol Genet 2015; 25:223-32. [PMID: 26566671 DOI: 10.1093/hmg/ddv459] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 11/05/2015] [Indexed: 01/13/2023] Open
Abstract
Understanding epigenetic differences that distinguish neurons and glia is of fundamental importance to the nascent field of neuroepigenetics. A recent study used genome-wide bisulfite sequencing to survey differences in DNA methylation between these two cell types, in both humans and mice. That study minimized the importance of cell type-specific differences in CpG methylation, claiming these are restricted to localized genomic regions, and instead emphasized that widespread and highly conserved differences in non-CpG methylation distinguish neurons and glia. We reanalyzed the data from that study and came to markedly different conclusions. In particular, we found widespread cell type-specific differences in CpG methylation, with a genome-wide tendency for neuronal CpG-hypermethylation punctuated by regions of glia-specific hypermethylation. Alarmingly, our analysis indicated that the majority of genes identified by the primary study as exhibiting cell type-specific CpG methylation differences were misclassified. To verify the accuracy of our analysis, we isolated neuronal and glial DNA from mouse cortex and performed quantitative bisulfite pyrosequencing at nine loci. The pyrosequencing results corroborated our analysis, without exception. Most interestingly, we found that gene-associated neuron vs. glia CpG methylation differences are highly conserved across human and mouse, and are very likely to be functional. In addition to underscoring the importance of independent verification to confirm the conclusions of genome-wide epigenetic analyses, our data indicate that CpG methylation plays a major role in neuroepigenetics, and that the mouse is likely an excellent model in which to study the role of DNA methylation in human neurodevelopment and disease.
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Affiliation(s)
| | | | | | | | | | - Robert A Waterland
- Department of Pediatrics, Department of Molecular & Human Genetics, Baylor College of Medicine, USDA/ARS Children's Nutrition Research Center,Houston, TX, USA
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