124 results on '"Dahmane N"'
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2. L’immunothérapie orale au lait de vache : expérience d’un service de pédiatrie à Alger
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Dahmane, N., Sekfali, L., Bouferoua, F., Belaid, B., Berkane, I., Djidjik, R., and Benhalla, N.K.
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- 2020
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3. Four species of bacteria deterministically assemble to form a stable biofilm in a millifluidic channel
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Monmeyran, A., Benyoussef, W., Thomen, P., Dahmane, N., Baliarda, A., Jules, M., Aymerich, S., and Henry, N.
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- 2021
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4. EPH81 Statural Growth of at Term Newborns with Intrauterine Growth Retardation: A Prospective Cohort Study in Algeria
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Bouferoua, F, primary, Boucenna, H, additional, Bouterfas, N, additional, Dahmane, N, additional, Khiari, MEM, additional, Mahi, L, additional, and Benhalla, KN, additional
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- 2022
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5. 4 SPECIES OF BACTERIA DETERMINISTICALLY FORM A STABLE BIOFILM IN A MILLIFLUIDIC CHANNEL: ASSEMBLY PRINCIPLES
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Monmeyran, A., primary, Benyoussef, W., additional, Thomen, P., additional, Dahmane, N., additional, Baliarda, A., additional, Jules, M., additional, Aymerich, S., additional, and Henry, N., additional
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- 2021
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6. Autotransplantation for renovascular hypertension in children with solitary functioning kidney
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Krmar, R T, Sandberg, J, Ghahramani, L, Sikorska, W, Dahmane, N, Svensson, A, and Tydén, G
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- 2013
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7. La part de la mauvaise compliance chez les enfants sensibilisés aux pneumallergènes dans le non contrôle de l’asthme
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Dahmane, N., primary
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- 2020
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8. Activation of the transcription factor Gli1 and the Sonic hedgehog signalling pathway in skin tumours
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Dahmane, N., Lee, J., Robins, P., Heller, P., and Ruiz i Altaba, A.
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Basal cell carcinoma -- Research ,Genetic transcription -- Research ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - Abstract
Sporadic basal cell carcinoma (BCC) is a common malignant cancer. Overexpression of Sonic hedgehog (Shh) is shown to induce BCCs in mice. The ectopic expression of the zinc-finger transcription factor Gli1 in an embryonic frog epidermis, is shown to lead to the development of tumours expressing endogenous Gli1. It indicates that loss of Patched (Ptc) or overexpression of Shh is not the only cause of Gli1 induction and sporadic BCC formation.
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- 1997
9. P-209 – La bicuspidie aortique chez l'enfant dans tous ses états
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Aboura, R., primary, Ladjouze, A., additional, Kedji, L., additional, Maoudj, A., additional, Berkouk, K., additional, Bensmina, M., additional, Bouhafs, N., additional, Dahmane, N., additional, Melzi, S., additional, Anane, T., additional, and Laraba, A., additional
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- 2015
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10. P-474 – Neurofibromatose type I (NF1): une présentation clinique particulière
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Dahmane, N., primary, Kedji, L., additional, Melzi, S., additional, Berkouk, K., additional, Maoudj, A., additional, Bensmina, M., additional, Ladjouz, A., additional, Bouhafs, N., additional, Aboura, R., additional, Anane, T., additional, and Laraba, A., additional
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- 2015
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11. P-053 – Quelles normes utiliser pour le bilan lipidique chez l'enfant?
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Berkouk, K., primary, Bensmina, M., additional, Aboura, R., additional, Maoudj, A., additional, Kedji, L., additional, Ladjouze, A., additional, Bouhafs, N., additional, Dahmane, N., additional, Melzi, S., additional, Anane, T., additional, and Laraba, A., additional
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- 2015
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12. P-316 – Syndrome d'Escobar: Une pathologie méconnue de diagnostic facile
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Berkouk, K., primary, Benzaid, A., additional, Bouhafs, N., additional, Maoudj, A., additional, Kedjl, L., additional, Bensmina, M., additional, Ladjouze, A., additional, Aboura, R., additional, Melzi, S., additional, Dahmane, N., additional, Anane, T., additional, and Laraba, A., additional
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- 2015
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13. P-203 – Existe-t-il des lésions précoces d'athérosclérose en cas d'HF hétérozygotes?
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Berkouk, K., primary, Bensmina, M., additional, Kedji, L., additional, Maoudj, A., additional, Ladjouze, A., additional, Aboura, R., additional, Bouhafs, N., additional, Melzi, S., additional, Dahmane, N., additional, Anane, T., additional, and Laraba, A., additional
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- 2015
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14. SFP P-158 - Facteurs de risque de caries dentaires chez les enfants d’âge préscolaire
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Bensmina, M., primary, Berkouk, K., additional, Ladjouze, A., additional, Kedji, L., additional, Maoudj, A., additional, Bouhafs, N., additional, Dahmane, N., additional, Melzi, S., additional, Anane, T., additional, and Laraba, A., additional
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- 2014
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15. SFP P-013 - Education thérapeutique de l’enfant diabétique : Savoir et savoir faire
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Berkouk, K., primary, Bensmina, M., additional, Ladjouze, A., additional, Maoudj, A., additional, Aboura, R., additional, Kedji, L., additional, Melzi, S., additional, Bouhafs, N., additional, Dahmane, N., additional, Anane, T., additional, and Laraba, A., additional
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- 2014
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16. SFP P-001 - Facteurs de risque d’athérosclérose chez l’enfant
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Berkouk, K., primary, Bensmina, M., additional, Aboura, R., additional, Kedji, L., additional, Maoudj, A., additional, Ladjouze, A., additional, Bouhafs, N., additional, Melzi, S., additional, Dahmane, N., additional, Anane, T., additional, and Laraba, A., additional
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- 2014
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17. SFP P-034 - Anémies hémolytiques auto-immunes : À propos de 26 observations
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Kedji, L., primary, Maoudj, A., additional, Berkouk, K., additional, Bensmina, M., additional, Ladjouze, A., additional, Aboura, R., additional, Bouhafs, N., additional, Dahmane, N., additional, Melzi, S., additional, Anane, T., additional, and Laraba, A., additional
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- 2014
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18. Embryonic regionalization of the neocortex
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Ruiz Altaba, Ariel, Gitton, Y, and Dahmane, N
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Telencephalon/embryology ,nervous system ,Gene Expression Regulation ,Morphogenesis ,Animals ,Developmental ,Body Patterning ,Neocortex/embryology - Abstract
Understanding the development of the vertebrate brain and in particular that of the neocortex, where high brain functions reside, remains one of the most difficult and exciting tasks in biology. In this review, we discuss recent experimental evidence as well as different possibilities for the intrinsic regionalization of the embryonic dorsal telencephalon, which may be related to the formation of distinct functional areas in the adult neocortex.
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- 2001
19. Autotransplantation for renovascular hypertension in children with solitary functioning kidney
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Krmar, R T, primary, Sandberg, J, additional, Ghahramani, L, additional, Sikorska, W, additional, Dahmane, N, additional, Svensson, A, additional, and Tydén, G, additional
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- 2012
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20. RP58/ZNF238 directly modulates proneurogenic gene levels and is required for neuronal differentiation and brain expansion
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Xiang, C, primary, Baubet, V, additional, Pal, S, additional, Holderbaum, L, additional, Tatard, V, additional, Jiang, P, additional, Davuluri, R V, additional, and Dahmane, N, additional
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- 2011
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21. Sonic hedgehog regulates the growth and patterning of the cerebellum
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Dahmane, N., primary and Ruiz-i-Altaba, A., additional
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- 1999
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22. Erratum: Activation of the transcription factor Gli1 and the Sonic hedgehog signalling pathway in skin tumours
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Dahmane, N., primary, Lee, J., additional, Robins, P., additional, Heller, P., additional, and Altaba, A. Ruiz i, additional
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- 1997
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23. Corrections
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Dahmane, N., Lee, J., Robins, P., Heller, P., and Ruiz i Altaba, A.
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Genetic transcription -- Research ,Skin tumors -- Research ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - Published
- 1997
24. Down syndrome-critical region contains a gene homologous to Drosophila sim expressed during rat and human central nervous system development.
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Dahmane, N, primary, Charron, G, additional, Lopes, C, additional, Yaspo, M L, additional, Maunoury, C, additional, Decorte, L, additional, Sinet, P M, additional, Bloch, B, additional, and Delabar, J M, additional
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- 1995
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25. RP58/ZNF238 directly modulates proneurogenic gene levels and is required for neuronal differentiation and brain expansion.
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Xiang, C, Baubet, V, Pal, S, Holderbaum, L, Tatard, V, Jiang, P, Davuluri, R V, and Dahmane, N
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NEOCORTEX ,TUMOR growth ,BRAIN tumors ,CEREBRAL cortex ,NEURONS - Abstract
Although neurogenic pathways have been described in the developing neocortex, less is known about mechanisms ensuring correct neuronal differentiation thus also preventing tumor growth. We have shown that RP58 (aka zfp238 or znf238) is highly expressed in differentiating neurons, that its expression is lost or diminished in brain tumors, and that its reintroduction blocks their proliferation. Mice with loss of RP58 die at birth with neocortical defects. Using a novel conditional RP58 allele here we show that its CNS-specific loss yields a novel postnatal phenotype: microencephaly, agenesis of the corpus callosum and cerebellar hypoplasia that resembles the chr1qter deletion microcephaly syndrome in human. RP58 mutant brains maintain precursor pools but have reduced neuronal and increased glial differentiation. Well-timed downregulation of pax6, ngn2 and neuroD1 depends on RP58 mediated transcriptional repression, ngn2 and neuroD1 being direct targets. Thus, RP58 may act to favor neuronal differentiation and brain growth by coherently repressing multiple proneurogenic genes in a timely manner. [ABSTRACT FROM AUTHOR]
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- 2012
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26. The Sonic Hedgehog-Gli pathway regulates dorsal brain growth and tumorigenesis.
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Dahmane, N, Sánchez, P, Gitton, Y, Palma, V, Sun, T, Beyna, M, Weiner, H, and Ruiz i Altaba, A
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The mechanisms that regulate the growth of the brain remain unclear. We show that Sonic hedgehog (Shh) is expressed in a layer-specific manner in the perinatal mouse neocortex and tectum, whereas the Gli genes, which are targets and mediators of SHH signaling, are expressed in proliferative zones. In vitro and in vivo assays show that SHH is a mitogen for neocortical and tectal precursors and that it modulates cell proliferation in the dorsal brain. Together with its role in the cerebellum, our findings indicate that SHH signaling unexpectedly controls the development of the three major dorsal brain structures. We also show that a variety of primary human brain tumors and tumor lines consistently express the GLI genes and that cyclopamine, a SHH signaling inhibitor, inhibits the proliferation of tumor cells. Using the in vivo tadpole assay system, we further show that misexpression of GLI1 induces CNS hyperproliferation that depends on the activation of endogenous Gli1 function. SHH-GLI signaling thus modulates normal dorsal brain growth by controlling precursor proliferation, an evolutionarily important and plastic process that is deregulated in brain tumors.
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- 2001
27. Embryonic regionalization of the neocortex
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Altaba, A. Ruiz i, Gitton, Y., and Dahmane, N.
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- 2001
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28. Ovarian vein thrombosis with symptoms prior to term - a case report
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Wernekinck, C., Dahmane, N., Petsson, A., and Thomassen, P.
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- 1997
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29. Immunoglobulin superfamily 3 (Igsf3) function is dispensable for brain development.
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Cocito C, Xiang C, Huang M, Gongora T, Surana P, Davuluri R, Dahmane N, and Greenfield JP
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- Animals, Mice, Neurons metabolism, Membrane Proteins metabolism, Membrane Proteins genetics, Neurogenesis genetics, Immunoglobulins genetics, Immunoglobulins metabolism, Gene Expression Regulation, Developmental, Mice, Knockout, Brain metabolism, Brain growth & development, Cell Movement genetics
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The Immunoglobulin superfamily (IgSF) is a heterogeneous and conserved family of adhesion proteins crucial during the development of the central nervous system including neuronal migration and synaptogenesis. The Immunoglobulin superfamily member 3 (IGSF3) is expressed in the developing brain and has been suggested to play a role during morphological development of the granule cells neurites in the cerebellum. In addition, a role for IGSF3 in supporting glioma progression has been recently demonstrated. Remaining unexplored is the physiological role of IGSF3 in regulating brain development, including neocortical development. We generated an Igsf3 knockout (KO) mouse using a CRISPR/Cas9-based approach and explored the function of Igsf3 in regulating cortical development. We found that Igsf3 largely co-localizes with other IgSF proteins during cortical development and despite its expression being developmentally regulated in neuronal progenitors and in postmitotic neurons, Igsf3 is not essential for brain development, neuronal migration, or neuronal maturation., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)
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- 2025
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30. Designing a Time-Dependent Therapeutic Strategy using CDK4/6 Inhibitors in an Intracranial ATRT Model.
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Martin B, Guadix SW, Sathian R, Laramee M, Pandey A, Ray I, Wang A, Davuluri R, Thomas CJ, Dahmane N, and Souweidane M
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Background: Inhibitors targeting cyclin-dependent kinases 4 and 6 (CDK4/6), crucial for cell cycle regulation, have shown promise in early-stage studies for treating central nervous system (CNS) tumors. However, challenges such as limited CNS penetration, optimal treatment duration, and systemic side effects have impeded their clinical translation for pediatric brain tumors (PBTs)., Methods: We evaluated the potency of CDK4/6 inhibitors across various PBTs cell lines, focusing particularly on palbociclib against atypical teratoid rhabdoid tumor (ATRT) with cell viability assays and gene expression analysis. Additionally, we assessed the efficacy and safety of intrathecal (IT) delivery of palbociclib through neurotoxicity and pharmacokinetic studies, along with survival assessments in murine leptomeningeal ATRT models., Results: Palbociclib showed the highest potency across various PBT cells, with extended treatments reducing growth inhibition 50 (GI50) values from the micromolar to nanomolar range. It suppressed critical cell cycle genes (CCNB1, CCNA2, CDK1) in BT-16 ATRT cells. Neurotoxicity (GFAP, CD45, NeuN, Iba1) and pharmacokinetic assays confirmed IT route as a feasible and effective method for delivering palbociclib to the cerebrospinal fluid (CSF), avoiding systemic toxicity and enhancing drug concentration to the brain. Finally, metronomic IT delivery using an osmotic pump (48mg/kg) increased survival in two murine leptomeningeal ATRT models, showcasing its potential as a novel therapy for leptomeningeal tumors., Conclusions: Metronomic IT delivery of palbociclib enhances drug efficacy and safety, improves survival, and offers a promising treatment strategy for PBTs with CSF dissemination., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)
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- 2024
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31. Pooled CRISPR screens with joint single-nucleus chromatin accessibility and transcriptome profiling.
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Yan RE, Corman A, Katgara L, Wang X, Xue X, Gajic ZZ, Sam R, Farid M, Friedman SM, Choo J, Raimondi I, Ganesan S, Katsevich E, Greenfield JP, Dahmane N, and Sanjana NE
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Pooled single-cell CRISPR screens have profiled either gene expression or chromatin accessibility but not both modalities. Here we develop MultiPerturb-seq, a high-throughput CRISPR screening platform with joint single-nucleus chromatin accessibility, transcriptome and guide RNA capture using combinatorial indexing combined with droplet microfluidics to scale throughput and integrate all three modalities. We identify key differentiation genes in a rare pediatric cancer and establish ZNHIT1 as a potential target for cancer reprogramming therapy., Competing Interests: Competing interests: The New York Genome Center and New York University have applied for patents related to the work in this article. N.E.S. is an adviser to Qiagen and a cofounder and adviser of TruEdit Bio and OverT Bio. The other authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)
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- 2024
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32. The Genetics of Chiari 1 Malformation.
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Yan RE, Chae JK, Dahmane N, Ciaramitaro P, and Greenfield JP
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Chiari malformation type 1 (CM1) is a structural defect that involves the herniation of the cerebellar tonsils through the foramen magnum, causing mild to severe neurological symptoms. Little is known about the molecular and developmental mechanisms leading to its pathogenesis, prompting current efforts to elucidate genetic drivers. Inherited genetic disorders are reported in 2-3% of CM1 patients; however, CM1, including familial forms, is predominantly non-syndromic. Recent work has focused on identifying CM1-asscoiated variants through the study of both familial cases and de novo mutations using exome sequencing. This article aims to review the current understanding of the genetics of CM1. We discuss three broad classes of CM1 based on anatomy and link them with genetic lesions, including posterior fossa-linked, macrocephaly-linked, and connective tissue disorder-linked CM1. Although the genetics of CM1 are only beginning to be understood, we anticipate that additional studies with diverse patient populations, tissue types, and profiling technologies will reveal new insights in the coming years.
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- 2024
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33. Influence of focused ultrasound on locoregional drug delivery to the brain: Potential implications for brain tumor therapy.
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Uribe Cardenas R, Laramee M, Ray I, Dahmane N, Souweidane M, and Martin B
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- Mice, Animals, Blood-Brain Barrier, Drug Delivery Systems methods, Sonication methods, Microbubbles, Brain, Brain Neoplasms drug therapy
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Introduction: Efficient delivery of therapeutics across the blood-brain barrier (BBB) for the treatment of central nervous system (CNS) tumors is a major challenge to the development of safe and efficacious therapies. Locoregional drug delivery platforms offer an improved therapeutic index by achieving high drug concentrations in the target tissue with negligible systemic exposure. Intrathecal (intraventricular) [IT] and convection-enhanced delivery [CED] are two clinically relevant methods being employed for various CNS malignancies. Both of these standalone platforms suffer from passive post-administration distribution forces, sometimes limiting the desired distribution for tumor therapy. Focused ultrasound and microbubble-mediated blood-brain barrier opening (FUS-BBBO) is a recent modality used for enhanced drug delivery. It is postulated that coupling of FUS with these alternative delivery routes may provide benefits. Multimodality FUS may provide the desired ability to increase the depth of parenchymal delivery following IT administration and provide a means for contour directionality with CED. Further, the transient enhanced permeability achieved with FUS-BBBO is well established, but drug residence and transit times, important to clinical dose scheduling, have not yet been defined. The present investigation comprises two discrete studies: 1. Conduct a comprehensive quantitative evaluation to elucidate the effect of FUS-BBBO as it relates to varying routes of administration (IT and IV) in its capacity to facilitate drug penetration within the striatal-thalamic region. 2. Investigate the impact of combining FUS-BBBO with CED on drug distribution, with a specific focus on the temporal dynamics of drug retention within the target region., Methods: Firstly, we quantitatively assessed how FUS-BBBO coupled with IT and IV altered fluorescent dye (Dextran 2000 kDa and 70 kDa) distribution and concentration in a predetermined striatal-thalamic region in naïve mice. Secondly, we analyzed the pharmacokinetic effects of using FUS mediated BBB disruption coupled with CED by measuring the volume of distribution and time-dependent concentration of the dye., Results: Our results indicate that IV administration coupled with FUS-BBBO successfully enhances delivery of dye into the pre-defined sonication targets. Conversely, measurable dye in the sonication target was consistently less after IT administration. FUS enhances the distribution volume of dye after CED. Furthermore, a shorter time of residence was observed when CED was coupled with FUS-BBBO application when compared to CED alone., Conclusion: 1. Based on our findings, IV delivery coupled with FUS-BBBO is a more efficient means for delivery to deep targets (i.e. striatal-thalamic region) within a predefined spatial conformation compared to IT administration. 2. FUS-BBBO increases the volume of distribution (Vd) of dye after CED administration, but results in a shorter time of residence. Whether this finding is reproducible with other classes of agents (e.g., cytotoxic agents, antibodies, viral particles, cellular therapies) needs to be studied., (Copyright © 2023 Elsevier B.V. All rights reserved.)
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- 2023
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34. Leptomeningeal dissemination in pediatric brain tumors.
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Cocito C, Martin B, Giantini-Larsen AM, Valcarce-Aspegren M, Souweidane MM, Szalontay L, Dahmane N, and Greenfield JP
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- Child, Humans, Prognosis, Meningeal Neoplasms diagnosis, Meningeal Neoplasms secondary, Brain Neoplasms pathology, Medulloblastoma diagnosis, Medulloblastoma pathology, Cerebellar Neoplasms pathology
- Abstract
Leptomeningeal disease (LMD) in pediatric brain tumors (PBTs) is a poorly understood and categorized phenomenon. LMD incidence rates, as well as diagnosis, treatment, and screening practices, vary greatly depending on the primary tumor pathology. While LMD is encountered most frequently in medulloblastoma, reports of LMD have been described across a wide variety of PBT pathologies. LMD may be diagnosed simultaneously with the primary tumor, at time of recurrence, or as primary LMD without a primary intraparenchymal lesion. Dissemination and seeding of the cerebrospinal fluid (CSF) involves a modified invasion-metastasis cascade and is often the result of direct deposition of tumor cells into the CSF. Cells develop select environmental advantages to survive the harsh, nutrient poor and turbulent environment of the CSF and leptomeninges. Improved understanding of the molecular mechanisms that underlie LMD, along with improved diagnostic and treatment approaches, will help the prognosis of children affected by primary brain tumors., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)
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- 2023
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35. Preclinical validation of a novel therapeutic strategy for choroid plexus carcinoma.
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Martin B, Garman T, Laramee M, Wang A, Zhang X, Beck E, Wilson K, Klumpp-Thomas C, McKnight C, Xu X, Hagen N, Holland D, Dahmane N, Thomas CJ, and Souweidane M
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- Child, Humans, Mice, Animals, Melphalan, Topotecan, Mammals, Choroid Plexus Neoplasms drug therapy, Choroid Plexus Neoplasms genetics, Choroid Plexus Neoplasms pathology, Carcinoma
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Choroid plexus carcinoma (CPC) is a rare infantile brain tumor with an aggressive clinical course that often leaves children with debilitating side effects due to aggressive and toxic chemotherapies. Development of novel therapeutical strategies for this disease have been extremely limited owing to the rarity of the disease and the paucity of biologically relevant substrates. We conducted the first high-throughput screen (HTS) on a human patient-derived CPC cell line (Children Cancer Hospital Egypt, CCHE-45) and identified 427 top hits highlighting key molecular targets in CPC. Furthermore, a combination screen with a wide variety of targets revealed multiple synergistic combinations that may pave the way for novel therapeutical strategies against CPC. Based on in vitro efficiency, central nervous system (CNS) penetrance ability and feasible translational potential, two combinations using a DNA alkylating or topoisomerase inhibitors in combination with an ataxia telangiectasia mutated and rad3 (ATR) inhibitor (topotecan/elimusertib and melphalan/elimusertib respectively) were validated in vitro and in vivo. Pharmacokinetic assays established increased brain penetrance with intra-arterial (IA) delivery over intra-venous (IV) delivery and demonstrated a higher CNS penetrance for the combination melphalan/elimusertib. The mechanisms of synergistic activity for melphalan/elimusertib were assessed through transcriptome analyses and showed dysregulation of key oncogenic pathways (e.g. MYC, mammalian target of rapamycin mTOR, p53) and activation of critical biological processes (e.g. DNA repair, apoptosis, hypoxia, interferon gamma). Importantly, IA administration of melphalan combined with elimusertib led to a significant increase in survival in a CPC genetic mouse model. In conclusion, this study is, to the best of our knowledge, the first that identifies multiple promising combinatorial therapeutics for CPC and emphasizes the potential of IA delivery for the treatment of CPC., (Copyright © 2023 Elsevier B.V. All rights reserved.)
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- 2023
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36. Developments in high-throughput functional epigenomics: CRISPR-single-cell assay for transposase-accessible chromatin using sequencing screens.
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E Yan R, P Greenfield J, and Dahmane N
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- Chromatin Immunoprecipitation Sequencing, Clustered Regularly Interspaced Short Palindromic Repeats, High-Throughput Nucleotide Sequencing, Humans, Sequence Analysis, DNA, Transposases genetics, Transposases metabolism, Chromatin genetics, Epigenomics
- Abstract
Tweetable abstract CRISPR-scATAC-seq screens pave the way for high-throughput functional epigenomics by linking perturbations to a broad view of epigenetic state and messages hidden within accessible sequences.
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- 2022
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37. RP58 Represses Transcriptional Programs Linked to Nonneuronal Cell Identity and Glioblastoma Subtypes in Developing Neurons.
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Xiang C, Frietze KK, Bi Y, Li Y, Dal Pozzo V, Pal S, Alexander N, Baubet V, D'Acunto V, Mason CE, Davuluri RV, and Dahmane N
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- Animals, Cell Differentiation genetics, Cell Movement genetics, Mice, Neurogenesis physiology, Neuroglia metabolism, Repressor Proteins genetics, Gene Expression Regulation, Developmental physiology, Glioblastoma metabolism, Neurons metabolism, Repressor Proteins metabolism
- Abstract
How mammalian neuronal identity is progressively acquired and reinforced during development is not understood. We have previously shown that loss of RP58 (ZNF238 or ZBTB18), a BTB/POZ-zinc finger-containing transcription factor, in the mouse brain leads to microcephaly, corpus callosum agenesis, and cerebellum hypoplasia and that it is required for normal neuronal differentiation. The transcriptional programs regulated by RP58 during this process are not known. Here, we report for the first time that in embryonic mouse neocortical neurons a complex set of genes normally expressed in other cell types, such as those from mesoderm derivatives, must be actively repressed in vivo and that RP58 is a critical regulator of these repressed transcriptional programs. Importantly, gene set enrichment analysis (GSEA) analyses of these transcriptional programs indicate that repressed genes include distinct sets of genes significantly associated with glioma progression and/or pluripotency. We also demonstrate that reintroducing RP58 in glioma stem cells leads not only to aspects of neuronal differentiation but also to loss of stem cell characteristics, including loss of stem cell markers and decrease in stem cell self-renewal capacities. Thus, RP58 acts as an in vivo master guardian of the neuronal identity transcriptome, and its function may be required to prevent brain disease development, including glioma progression.
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- 2021
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38. PET, image-guided HDAC inhibition of pediatric diffuse midline glioma improves survival in murine models.
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Tosi U, Kommidi H, Adeuyan O, Guo H, Maachani UB, Chen N, Su T, Zhang G, Pisapia DJ, Dahmane N, Ting R, and Souweidane MM
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- Animals, Convection, Disease Models, Animal, Drug Delivery Systems methods, Humans, Mice, Positron-Emission Tomography, Brain Stem Neoplasms pathology, Glioma diagnostic imaging, Glioma drug therapy, Glioma pathology
- Abstract
Efforts at altering the dismal prognosis of pediatric midline gliomas focus on direct delivery strategies like convection-enhanced delivery (CED), where a cannula is implanted into tumor. Successful CED treatments require confirmation of tumor coverage, dosimetry, and longitudinal in vivo pharmacokinetic monitoring. These properties would be best determined clinically with image-guided dosimetry using theranostic agents. In this study, we combine CED with novel, molecular-grade positron emission tomography (PET) imaging and show how PETobinostat, a novel PET-imageable HDAC inhibitor, is effective against DIPG models. PET data reveal that CED has significant mouse-to-mouse variability; imaging is used to modulate CED infusions to maximize tumor saturation. The use of PET-guided CED results in survival prolongation in mouse models; imaging shows the need of CED to achieve high brain concentrations. This work demonstrates how personalized image-guided drug delivery may be useful in potentiating CED-based treatment algorithms and supports a foundation for clinical translation of PETobinostat., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)
- Published
- 2020
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39. Missing diversity in brain tumor trials.
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Taha B, Winston G, Tosi U, Hartley B, Hoffman C, Dahmane N, Mason CE, and Greenfield JP
- Abstract
Background: Clinical trials for brain tumors represent a significant opportunity for both patients and providers to understand and combat a disease with substantial morbidity. The aim of this study was to quantify and map ethnic and racial representation in brain tumor trials and examine the potential gaps in trial recruitment. We also show that these representation gaps persist even in large multicultural cities like New York City., Methods: We analyzed brain tumor clinical trials registered on www.clinicaltrials.gov between July 1, 2005 and completed on or before November 11, 2017. We used a combination of PubMed/MEDLINE and Google Scholar to find associated publications and obtained trial information as well as patient demographic information (when available) including race or ancestry., Results: Out of 471 trials, 27% had no published results. Only 28.4% of trials with results reported race or ethnicity of trial participants, with no observed upward trend by year. Whites were significantly overrepresented in trials for metastatic brain tumors ( P < .001) and high-grade trials ( P < .001). Blacks/African Americans (AAs), Hispanics, and Asians were significantly underrepresented ( P < .001) in high-grade trials, while only Blacks/AAs were underrepresented in trials for metastatic brain tumors ( P < .001). Representation gaps were not observed in pediatric trials. Despite being a multicultural hub, New York City displayed similar gaps in trial representation., Conclusions: Despite increasing representation in the American population, minorities are underrepresented in brain tumor trials. In addition, despite numerous legal requirements and ethical mandates, published results including race-based information are remarkably absent from 70% of brain tumor trials., (© The Author(s) 2020. Published by Oxford University Press, the Society for Neuro-Oncology and the European Association of Neuro-Oncology.)
- Published
- 2020
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40. B7-H3 as a Prognostic Biomarker and Therapeutic Target in Pediatric central nervous system Tumors.
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Maachani UB, Tosi U, Pisapia DJ, Mukherjee S, Marnell CS, Voronina J, Martinez D, Santi M, Dahmane N, Zhou Z, Hawkins C, and Souweidane MM
- Abstract
B7-H3 (CD276), a member of the B7 superfamily, is an important factor in downregulating immune responses against tumors. It is also aberrantly expressed in many human malignancies. Beyond immune regulatory roles, its overexpression has been linked to invasive metastatic potential and poor prognosis in patients with cancer. Antibody-dependent cell-mediated cytotoxicity strategies targeting B7-H3 are currently in development, and early-phase clinical trials have shown encouraging preliminary results. To understand the role of B7-H3 in pediatric central nervous system (CNS) malignancies, a comprehensive panel of primary CNS tumors of childhood was examined by immunohistochemistry for levels and extent of B7-H3 expression. In addition, B7-H3 m-RNA expression status and association with overall survival in various pediatric CNS tumor types was accessed by curating publicly available patient gene expression data sets derived from bioinformatics analysis and visualization platforms (GlioVis). We demonstrate that B7-H3 is broadly expressed in pediatric glial and nonglial CNS tumors, and its aberrant expression, as determined by immunohistochemical staining intensity, correlates with tumor grade. Moreover, high B7-H3 m-RNA expression is significantly associated with worse survival and could potentially improve prognostication in various brain tumor types of childhood. B7-H3 can be used as a therapeutic target, given its tumor selectivity and the availability of targeted therapeutic agents to this antigen., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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41. Multivariate Analysis of Preoperative Magnetic Resonance Imaging Reveals Transcriptomic Classification of de novo Glioblastoma Patients.
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Rathore S, Akbari H, Bakas S, Pisapia JM, Shukla G, Rudie JD, Da X, Davuluri RV, Dahmane N, O'Rourke DM, and Davatzikos C
- Abstract
Glioblastoma, the most frequent primary malignant brain neoplasm, is genetically diverse and classified into four transcriptomic subtypes, i. e., classical, mesenchymal, proneural, and neural. Currently, detection of transcriptomic subtype is based on ex vivo analysis of tissue that does not capture the spatial tumor heterogeneity. In view of accumulative evidence of in vivo imaging signatures summarizing molecular features of cancer, this study seeks robust non-invasive radiographic markers of transcriptomic classification of glioblastoma, based solely on routine clinically-acquired imaging sequences. A pre-operative retrospective cohort of 112 pathology-proven de novo glioblastoma patients, having multi-parametric MRI (T1, T1-Gd, T2, T2-FLAIR), collected from the Hospital of the University of Pennsylvania were included. Following tumor segmentation into distinct radiographic sub-regions, diverse imaging features were extracted and support vector machines were employed to multivariately integrate these features and derive an imaging signature of transcriptomic subtype. Extracted features included intensity distributions, volume, morphology, statistics, tumors' anatomical location, and texture descriptors for each tumor sub-region. The derived signature was evaluated against the transcriptomic subtype of surgically-resected tissue specimens, using a 5-fold cross-validation method and a receiver-operating-characteristics analysis. The proposed model was 71% accurate in distinguishing among the four transcriptomic subtypes. The accuracy (sensitivity/specificity) for distinguishing each subtype (classical, mesenchymal, proneural, neural) from the rest was equal to 88.4% (71.4/92.3), 75.9% (83.9/72.8), 82.1% (73.1/84.9), and 75.9% (79.4/74.4), respectively. The findings were also replicated in The Cancer Genomic Atlas glioblastoma dataset. The obtained imaging signature for the classical subtype was dominated by associations with features related to edge sharpness, whereas for the mesenchymal subtype had more pronounced presence of higher T2 and T2-FLAIR signal in edema, and higher volume of enhancing tumor and edema. The proneural and neural subtypes were characterized by the lower T1-Gd signal in enhancing tumor and higher T2-FLAIR signal in edema, respectively. Our results indicate that quantitative multivariate analysis of features extracted from clinically-acquired MRI may provide a radiographic biomarker of the transcriptomic profile of glioblastoma. Importantly our findings can be influential in surgical decision-making, treatment planning, and assessment of inoperable tumors., (Copyright © 2019 Rathore, Akbari, Bakas, Pisapia, Shukla, Rudie, Da, Davuluri, Dahmane, O'Rourke and Davatzikos.)
- Published
- 2019
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42. Immune landscapes associated with different glioblastoma molecular subtypes.
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Martinez-Lage M, Lynch TM, Bi Y, Cocito C, Way GP, Pal S, Haller J, Yan RE, Ziober A, Nguyen A, Kandpal M, O'Rourke DM, Greenfield JP, Greene CS, Davuluri RV, and Dahmane N
- Subjects
- Antigens, CD20 analysis, Antigens, CD20 immunology, Brain Neoplasms pathology, Glioblastoma pathology, Humans, Brain Neoplasms immunology, Glioblastoma immunology, Immunity, Cellular immunology, Tumor Microenvironment immunology
- Abstract
Recent work has highlighted the tumor microenvironment as a central player in cancer. In particular, interactions between tumor and immune cells may help drive the development of brain tumors such as glioblastoma multiforme (GBM). Despite significant research into the molecular classification of glioblastoma, few studies have characterized in a comprehensive manner the immune infiltrate in situ and within different GBM subtypes.In this study, we use an unbiased, automated immunohistochemistry-based approach to determine the immune phenotype of the four GBM subtypes (classical, mesenchymal, neural and proneural) in a cohort of 98 patients. Tissue Micro Arrays (TMA) were stained for CD20 (B lymphocytes), CD5, CD3, CD4, CD8 (T lymphocytes), CD68 (microglia), and CD163 (bone marrow derived macrophages) antibodies. Using automated image analysis, the percentage of each immune population was calculated with respect to the total tumor cells. Mesenchymal GBMs displayed the highest percentage of microglia, macrophage, and lymphocyte infiltration. CD68
+ and CD163+ cells were the most abundant cell populations in all four GBM subtypes, and a higher percentage of CD163+ cells was associated with a worse prognosis. We also compared our results to the relative composition of immune cell type infiltration (using RNA-seq data) across TCGA GBM tumors and validated our results obtained with immunohistochemistry with an external cohort and a different method. The results of this study offer a comprehensive analysis of the distribution and the infiltration of the immune components across the four commonly described GBM subgroups, setting the basis for a more detailed patient classification and new insights that may be used to better apply or design immunotherapies for GBM.- Published
- 2019
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43. Transcriptome signatures associated with meningioma progression.
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Viaene AN, Zhang B, Martinez-Lage M, Xiang C, Tosi U, Thawani JP, Gungor B, Zhu Y, Roccograndi L, Zhang L, Bailey RL, Storm PB, O'Rourke DM, Resnick AC, Grady MS, and Dahmane N
- Subjects
- Computational Biology, Female, Humans, Male, Meningeal Neoplasms pathology, Meningioma pathology, Neoplasm Grading, Neurofibromin 2 genetics, RNA-Seq, Tumor Microenvironment genetics, Disease Progression, Meningeal Neoplasms genetics, Meningioma genetics, Transcriptome
- Abstract
Meningiomas are the most common primary brain tumor of adults. The majority are benign (WHO grade I), with a mostly indolent course; 20% of them (WHO grade II and III) are, however, considered aggressive and require a more complex management. WHO grade II and III tumors are heterogeneous and, in some cases, can develop from a prior lower grade meningioma, although most arise de novo. Mechanisms leading to progression or implicated in de novo grade II and III tumorigenesis are poorly understood. RNA-seq was used to profile the transcriptome of grade I, II, and III meningiomas and to identify genes that may be involved in progression. Bioinformatic analyses showed that grade I meningiomas that progress to a higher grade are molecularly different from those that do not. As such, we identify GREM2, a regulator of the BMP pathway, and the snoRNAs SNORA46 and SNORA48, as being significantly reduced in meningioma progression. Additionally, our study has identified several novel fusion transcripts that are differentially present in meningiomas, with grade I tumors that did not progress presenting more fusion transcripts than all other tumors. Interestingly, our study also points to a difference in the tumor immune microenvironment that correlates with histopathological grade.
- Published
- 2019
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44. Checkpoint Blockade Reverses Anergy in IL-13Rα2 Humanized scFv-Based CAR T Cells to Treat Murine and Canine Gliomas.
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Yin Y, Boesteanu AC, Binder ZA, Xu C, Reid RA, Rodriguez JL, Cook DR, Thokala R, Blouch K, McGettigan-Croce B, Zhang L, Konradt C, Cogdill AP, Panjwani MK, Jiang S, Migliorini D, Dahmane N, Posey AD Jr, June CH, Mason NJ, Lin Z, O'Rourke DM, and Johnson LA
- Abstract
We generated two humanized interleukin-13 receptor α2 (IL-13Rα2) chimeric antigen receptors (CARs), Hu07BBz and Hu08BBz, that recognized human IL-13Rα2, but not IL-13Rα1. Hu08BBz also recognized canine IL-13Rα2. Both of these CAR T cell constructs demonstrated superior tumor inhibitory effects in a subcutaneous xenograft model of human glioma compared with a humanized EGFRvIII CAR T construct used in a recent phase 1 clinical trial (ClinicalTrials.gov: NCT02209376). The Hu08BBz demonstrated a 75% reduction in orthotopic tumor growth using low-dose CAR T cell infusion. Using combination therapy with immune checkpoint blockade, humanized IL-13Rα2 CAR T cells performed significantly better when combined with CTLA-4 blockade, and humanized EGFRvIII CAR T cells' efficacy was improved by PD-1 and TIM-3 blockade in the same mouse model, which was correlated with the levels of checkpoint molecule expression in co-cultures with the same tumor in vitro . Humanized IL-13Rα2 CAR T cells also demonstrated benefit from a self-secreted anti-CTLA-4 minibody in the same mouse model. In addition to a canine glioma cell line (J3T), canine osteosarcoma lung cancer and leukemia cell lines also express IL-13Rα2 and were recognized by Hu08BBz. Canine IL-13Rα2 CAR T cell was also generated and tested in vitro by co-culture with canine tumor cells and in vivo in an orthotopic model of canine glioma. Based on these results, we are designing a pre-clinical trial to evaluate the safety of canine IL-13Rα2 CAR T cells in dog with spontaneous IL-13Rα2-positive glioma, which will help to inform a human clinical trial design for glioblastoma using humanized scFv-based IL-13Rα2 targeting CAR T cells.
- Published
- 2018
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45. In vivo evaluation of EGFRvIII mutation in primary glioblastoma patients via complex multiparametric MRI signature.
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Akbari H, Bakas S, Pisapia JM, Nasrallah MP, Rozycki M, Martinez-Lage M, Morrissette JJD, Dahmane N, O'Rourke DM, and Davatzikos C
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Brain Neoplasms pathology, Cohort Studies, Female, Follow-Up Studies, Glioblastoma pathology, Humans, Male, Middle Aged, Prognosis, Young Adult, Biomarkers, Tumor genetics, Brain Neoplasms genetics, Diffusion Tensor Imaging methods, ErbB Receptors genetics, Glioblastoma genetics, Magnetic Resonance Imaging methods, Mutation
- Abstract
Background: Epidermal growth factor receptor variant III (EGFRvIII) is a driver mutation and potential therapeutic target in glioblastoma. Non-invasive in vivo EGFRvIII determination, using clinically acquired multiparametric MRI sequences, could assist in assessing spatial heterogeneity related to EGFRvIII, currently not captured via single-specimen analyses. We hypothesize that integration of subtle, yet distinctive, quantitative imaging/radiomic patterns using machine learning may lead to non-invasively determining molecular characteristics, and particularly the EGFRvIII mutation., Methods: We integrated diverse imaging features, including the tumor's spatial distribution pattern, via support vector machines, to construct an imaging signature of EGFRvIII. This signature was evaluated in independent discovery (n = 75) and replication (n = 54) cohorts of de novo glioblastoma, and compared with the EGFRvIII status obtained through an assay based on next-generation sequencing., Results: The cross-validated accuracy of the EGFRvIII signature in classifying the mutation status in individual patients of the independent discovery and replication cohorts was 85.3% (specificity = 86.3%, sensitivity = 83.3%, area under the curve [AUC] = 0.85) and 87% (specificity = 90%, sensitivity = 78.6%, AUC = 0.86), respectively. The signature was consistent with EGFRvIII+ tumors having increased neovascularization and cell density, as well as a distinctive spatial pattern involving relatively more frontal and parietal regions compared with EGFRvIII- tumors., Conclusions: An imaging signature of EGFRvIII was found, revealing a complex, yet distinct macroscopic glioblastoma phenotype. By non-invasively capturing the tumor in its entirety, the proposed methodology can assist in evaluating the tumor's spatial heterogeneity, hence overcoming common spatial sampling limitations of tissue-based analyses. This signature can preoperatively stratify patients for EGFRvIII-targeted therapies, and potentially monitor dynamic mutational changes during treatment.
- Published
- 2018
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46. Eddy current evaluation of recovered conductive waste purity.
- Author
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Dahmane N, Ayad A, and Bensaid S
- Subjects
- Electric Impedance, Copper, Recycling
- Abstract
The main goal of this paper is to present a new approach to evaluate the recovered conductive granular waste purity. For this purpose, the eddy current approach which is commonly applied in nondestructive evaluation has been used. The experimental tests consist of several samples composed of copper particles mixed with sand inserted in a cylindrical container with solenoidal coil. The impedance of the coil is measured, using precision LRC-meter, for several frequencies per sample and used according to the Experiment Design Methodology (EDM) to determinate the relationship between input and output of experiments, to have a quadratic model that will be used for inversion. The input and output are successively impedance and percentage of copper particles contained in the container. The results show the capability of the proposed approach to evaluate the conductive recovered waste purity., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
- Full Text
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47. Radiomic MRI signature reveals three distinct subtypes of glioblastoma with different clinical and molecular characteristics, offering prognostic value beyond IDH1.
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Rathore S, Akbari H, Rozycki M, Abdullah KG, Nasrallah MP, Binder ZA, Davuluri RV, Lustig RA, Dahmane N, Bilello M, O'Rourke DM, and Davatzikos C
- Subjects
- ErbB Receptors analysis, Female, Humans, Male, O(6)-Methylguanine-DNA Methyltransferase analysis, Prognosis, Survival Analysis, Brain diagnostic imaging, Brain Neoplasms diagnostic imaging, Glioblastoma diagnostic imaging, Isocitrate Dehydrogenase analysis, Magnetic Resonance Imaging methods
- Abstract
The remarkable heterogeneity of glioblastoma, across patients and over time, is one of the main challenges in precision diagnostics and treatment planning. Non-invasive in vivo characterization of this heterogeneity using imaging could assist in understanding disease subtypes, as well as in risk-stratification and treatment planning of glioblastoma. The current study leveraged advanced imaging analytics and radiomic approaches applied to multi-parametric MRI of de novo glioblastoma patients (n = 208 discovery, n = 53 replication), and discovered three distinct and reproducible imaging subtypes of glioblastoma, with differential clinical outcome and underlying molecular characteristics, including isocitrate dehydrogenase-1 (IDH1), O
6 -methylguanine-DNA methyltransferase, epidermal growth factor receptor variant III (EGFRvIII), and transcriptomic subtype composition. The subtypes provided risk-stratification substantially beyond that provided by WHO classifications. Within IDH1-wildtype tumors, our subtypes revealed different survival (p < 0.001), thereby highlighting the synergistic consideration of molecular and imaging measures for prognostication. Moreover, the imaging characteristics suggest that subtype-specific treatment of peritumoral infiltrated brain tissue might be more effective than current uniform standard-of-care. Finally, our analysis found subtype-specific radiogenomic signatures of EGFRvIII-mutated tumors. The identified subtypes and their clinical and molecular correlates provide an in vivo portrait of phenotypic heterogeneity in glioblastoma, which points to the need for precision diagnostics and personalized treatment.- Published
- 2018
- Full Text
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48. Impact of Cell Surface Molecules on Conjugative Transfer of the Integrative and Conjugative Element ICE St3 of Streptococcus thermophilus.
- Author
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Dahmane N, Robert E, Deschamps J, Meylheuc T, Delorme C, Briandet R, Leblond-Bourget N, Guédon E, and Payot S
- Subjects
- Evolution, Molecular, Conjugation, Genetic, Gene Transfer, Horizontal, Genome, Bacterial, Streptococcus thermophilus genetics
- Abstract
Integrative conjugative elements (ICEs) are chromosomal elements that are widely distributed in bacterial genomes, hence contributing to genome plasticity, adaptation, and evolution of bacteria. Conjugation requires a contact between both the donor and the recipient cells and thus likely depends on the composition of the cell surface envelope. In this work, we investigated the impact of different cell surface molecules, including cell surface proteins, wall teichoic acids, lipoteichoic acids, and exopolysaccharides, on the transfer and acquisition of ICE St3 from Streptococcus thermophilus The transfer of ICE St3 from wild-type (WT) donor cells to mutated recipient cells increased 5- to 400-fold when recipient cells were affected in lipoproteins, teichoic acids, or exopolysaccharides compared to when the recipient cells were WT. These mutants displayed an increased biofilm-forming ability compared to the WT, suggesting better cell interactions that could contribute to the increase of ICE St3 acquisition. Microscopic observations of S. thermophilus cell surface mutants showed different phenotypes (aggregation in particular) that can also have an impact on conjugation. In contrast, the same mutations did not have the same impact when the donor cells, instead of recipient cells, were mutated. In that case, the transfer frequency of ICE St3 decreased compared to that with the WT. The same observation was made when both donor and recipient cells were mutated. The dominant effect of mutations in donor cells suggests that modifications of the cell envelope could impair the establishment or activity of the conjugation machinery required for DNA transport. IMPORTANCE ICEs contribute to horizontal gene transfer of adaptive traits (for example, virulence, antibiotic resistance, or biofilm formation) and play a considerable role in bacterial genome evolution, thus underlining the need of a better understanding of their conjugative mechanism of transfer. While most studies focus on the different functions encoded by ICEs, little is known about the effect of host factors on their conjugative transfer. Using ICE St3 of S. thermophilus as a model, we demonstrated the impact of lipoproteins, teichoic acids, and exopolysaccharides on ICE transfer and acquisition. This opens up new avenues to control gene transfer mediated by ICEs., (Copyright © 2018 American Society for Microbiology.)
- Published
- 2018
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49. Vascular niche IL-6 induces alternative macrophage activation in glioblastoma through HIF-2α.
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Wang Q, He Z, Huang M, Liu T, Wang Y, Xu H, Duan H, Ma P, Zhang L, Zamvil SS, Hidalgo J, Zhang Z, O'Rourke DM, Dahmane N, Brem S, Mou Y, Gong Y, and Fan Y
- Subjects
- Animals, Arginase immunology, Cell Line, Tumor, Cells, Cultured, Disease Progression, Humans, Macrophage Colony-Stimulating Factor immunology, Mice, Microvessels cytology, Monocytes immunology, Neoplasms, Experimental immunology, Transcriptional Activation, Tumor Microenvironment, Basic Helix-Loop-Helix Transcription Factors genetics, Endothelial Cells immunology, Glioblastoma immunology, Interleukin-6 immunology, Macrophage Activation immunology, Macrophages immunology
- Abstract
Spatiotemporal regulation of tumor immunity remains largely unexplored. Here we identify a vascular niche that controls alternative macrophage activation in glioblastoma (GBM). We show that tumor-promoting macrophages are spatially proximate to GBM-associated endothelial cells (ECs), permissive for angiocrine-induced macrophage polarization. We identify ECs as one of the major sources for interleukin-6 (IL-6) expression in GBM microenvironment. Furthermore, we reveal that colony-stimulating factor-1 and angiocrine IL-6 induce robust arginase-1 expression and macrophage alternative activation, mediated through peroxisome proliferator-activated receptor-γ-dependent transcriptional activation of hypoxia-inducible factor-2α. Finally, utilizing a genetic murine GBM model, we show that EC-specific knockout of IL-6 inhibits macrophage alternative activation and improves survival in the GBM-bearing mice. These findings illustrate a vascular niche-dependent mechanism for alternative macrophage activation and cancer progression, and suggest that targeting endothelial IL-6 may offer a selective and efficient therapeutic strategy for GBM, and possibly other solid malignant tumors.
- Published
- 2018
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50. SHP2 regulates proliferation and tumorigenicity of glioma stem cells.
- Author
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Roccograndi L, Binder ZA, Zhang L, Aceto N, Zhang Z, Bentires-Alj M, Nakano I, Dahmane N, and O'Rourke DM
- Subjects
- Adult, Aged, Brain Neoplasms pathology, Carcinogenesis pathology, Cell Culture Techniques, Cell Line, Tumor, Female, Gene Expression Regulation, Neoplastic, Gene Knockdown Techniques, Glioma pathology, Humans, Male, Neoplastic Stem Cells pathology, Protein Tyrosine Phosphatase, Non-Receptor Type 11 antagonists & inhibitors, Protein Tyrosine Phosphatase, Non-Receptor Type 11 genetics, Proto-Oncogene Mas, SOXB1 Transcription Factors metabolism, Tissue Scaffolds, Brain Neoplasms enzymology, Carcinogenesis metabolism, Cell Proliferation physiology, Glioma enzymology, Neoplastic Stem Cells enzymology, Protein Tyrosine Phosphatase, Non-Receptor Type 11 metabolism
- Abstract
SHP2 is a cytoplasmic protein tyrosine phosphatase (PTPase) involved in multiple signaling pathways and was the first identified proto-oncogene PTPase. Previous work in glioblastoma (GBM) has demonstrated the role of SHP2 PTPase activity in modulating the oncogenic phenotype of adherent GBM cell lines. Mutations in PTPN11, the gene encoding SHP2, have been identified with increasing frequency in GBM. Given the importance of SHP2 in developing neural stem cells, and the importance of glioma stem cells (GSCs) in GBM oncogenesis, we explored the functional role of SHP2 in GSCs. Using paired differentiated and stem cell primary cultures, we investigated the association of SHP2 expression with the tumor stem cell compartment. Proliferation and soft agar assays were used to demonstrate the functional contribution of SHP2 to cell growth and transformation. SHP2 expression correlated with SOX2 expression in GSC lines and was decreased in differentiated cells. Forced differentiation of GSCs by removal of growth factors, as confirmed by loss of SOX2 expression, also resulted in decreased SHP2 expression. Lentiviral-mediated knockdown of SHP2 inhibited proliferation. Finally, growth in soft-agar was similarly inhibited by loss of SHP2 expression. Our results show that SHP2 function is required for cell growth and transformation of the GSC compartment in GBM.
- Published
- 2017
- Full Text
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