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Negri G, Magini P, Milani D, Colapietro P, Rusconi D, Scarano E, Bonati MT, Priolo M, Crippa M, Mazzanti L, Wischmeijer A, Tamburrino F, Pippucci T, Finelli P, Larizza L, Gervasini C. From Whole Gene Deletion to Point Mutations of EP300-Positive Rubinstein-Taybi Patients: New Insights into the Mutational Spectrum and Peculiar Clinical Hallmarks. Hum Mutat 2015; 37:175-83. [PMID: 26486927 DOI: 10.1002/humu.22922] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 10/12/2015] [Indexed: 12/16/2022]
Abstract
Rubinstein-Taybi syndrome (RSTS) is a rare congenital neurodevelopmental disorder characterized by growth deficiency, skeletal abnormalities, dysmorphic features, and intellectual disability. Causative mutations in CREBBP and EP300 genes have been identified in ∼55% and ∼8% of affected individuals. To date, only 28 EP300 alterations in 29 RSTS clinically described patients have been reported. EP300 analysis of 22 CREBBP-negative RSTS patients from our cohort led us to identify six novel mutations: a 376-kb deletion depleting EP300 gene; an exons 17-19 deletion (c.(3141+1_3142-1)_(3590+1_3591-1)del/p.(Ile1047Serfs*30)); two stop mutations, (c.3829A>T/p.(Lys1277*) and c.4585C>T/p.(Arg1529*)); a splicing mutation (c.1878-12A>G/p.(Ala627Glnfs*11)), and a duplication (c.4640dupA/p.(Asn1547Lysfs*3)). All EP300-mutated individuals show a mild RSTS phenotype and peculiar findings including maternal gestosis, skin manifestation, especially nevi or keloids, back malformations, and a behavior predisposing to anxiety. Furthermore, the patient carrying the complete EP300 deletion does not show a markedly severe clinical picture, even if a more composite phenotype was noticed. By characterizing six novel EP300-mutated patients, this study provides further insights into the EP300-specific clinical presentation and expands the mutational repertoire including the first case of a whole gene deletion. These new data will enhance EP300-mutated cases identification highlighting distinctive features and will improve the clinical practice allowing a better genotype-phenotype correlation.
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Affiliation(s)
- Gloria Negri
- Genetica Medica, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italia
| | - Pamela Magini
- Laboratorio di Genetica Medica, Dipartimento di Scienze Mediche e Chirurgiche, Policlinico Ospedaliero Universitario S. Orsola-Malpighi, Bologna, Italia
| | - Donatella Milani
- Unità di Pediatria ad alta Intensità di Cura, Fondazione IRCCS Ca' Granda, Milano, Italia
| | - Patrizia Colapietro
- Genetica Medica, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italia
| | - Daniela Rusconi
- Genetica Medica, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italia
| | - Emanuela Scarano
- UO di Endocrinologia Pediatrica e Malattie Rare, Dipartimento di Pediatria, Ospedale Universitario S. Orsola Malpighi, Università degli Studi di Bologna, Bologna, Italia
| | - Maria Teresa Bonati
- Clinica di Genetica Medica, IRCCS Istituto Auxologico Italiano, Milano, Italia
| | - Manuela Priolo
- UOC Genetica Medica, Azienda Ospedaliera Bianchi-Melacrino-Morelli, Reggio Calabria, Italia
| | - Milena Crippa
- Laboratorio di Citogenetica e Genetica Molecolare, Centro di Ricerche e Tecnologie Biomediche, IRCCS Istituto Auxologico Italiano, Milano, Italia
| | - Laura Mazzanti
- UO di Endocrinologia Pediatrica e Malattie Rare, Dipartimento di Pediatria, Ospedale Universitario S. Orsola Malpighi, Università degli Studi di Bologna, Bologna, Italia
| | - Anita Wischmeijer
- Laboratorio di Genetica Medica, Dipartimento di Scienze Mediche e Chirurgiche, Policlinico Ospedaliero Universitario S. Orsola-Malpighi, Bologna, Italia
| | - Federica Tamburrino
- UO di Endocrinologia Pediatrica e Malattie Rare, Dipartimento di Pediatria, Ospedale Universitario S. Orsola Malpighi, Università degli Studi di Bologna, Bologna, Italia
| | - Tommaso Pippucci
- Laboratorio di Genetica Medica, Dipartimento di Scienze Mediche e Chirurgiche, Policlinico Ospedaliero Universitario S. Orsola-Malpighi, Bologna, Italia
| | - Palma Finelli
- Laboratorio di Citogenetica e Genetica Molecolare, Centro di Ricerche e Tecnologie Biomediche, IRCCS Istituto Auxologico Italiano, Milano, Italia.,Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milano, Italia
| | - Lidia Larizza
- Genetica Medica, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italia.,Laboratorio di Citogenetica e Genetica Molecolare, Centro di Ricerche e Tecnologie Biomediche, IRCCS Istituto Auxologico Italiano, Milano, Italia
| | - Cristina Gervasini
- Genetica Medica, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italia
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Yamamoto K, Yakushijin K, Okamura A, Ueda S, Nakamachi Y, Kawano S, Matsuoka H, Minami H. Hyperdiploidy and duplication of der(11)ins(10;11)(p12;q23q14) in acute myeloid leukemia with MLL/MLLT10fusion gene. Leuk Lymphoma 2013; 54:2055-8. [DOI: 10.3109/10428194.2012.762094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Lehnus KS, Donovan LK, Huang X, Zhao N, Warr TJ, Pilkington GJ, An Q. CD133 glycosylation is enhanced by hypoxia in cultured glioma stem cells. Int J Oncol 2013; 42:1011-7. [PMID: 23340741 DOI: 10.3892/ijo.2013.1787] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 10/17/2012] [Indexed: 11/06/2022] Open
Abstract
The cancer stem cell (CSC) marker CD133 is widely expressed in gliomas and employed mostly by use of the CD133/1 antibody which binds the extracellular glycosylated AC133 epitope. CD133 recognition may, however, be affected by its glycosylation pattern and oxygen tension. The present study investigates the effect of oxygen deprivation on CD133 expression and glycosylation status employing a high AC133-expressing glioblastoma multiforme (GBM) cell line, IN699. IN699 cells were cultured under normoxic (21% O2) and hypoxic (3% O2) conditions. CD133 expression was analysed by western blotting (WB), qRT-PCR, immunocytochemistry (ICC) and flow cytometry using the glycosylation-specific antibody CD133/1 and ab19898 which binds the unglycosylated intra-cellular residues of CD133. By flow cytometry, ab19898 detected 94.1% and 96.2% CD133+ cells under normoxia and hypoxia, respectively. Hypoxia significantly increased the percentage of CD133+ cells from 69% to 92% using CD133/1 (p<0.005). Moreover, a significantly higher geomean fluorescence intensity (GMI) was demonstrated by ab19898 (p<0.005) in CD133+ cells. WB and qRT-PCR results were consistent with flow cytometry data. Furthermore, over a period of 72-h incubation under normoxic and hypoxic conditions after autoMACS sorting, an average of 31.8% and 42.2%, respectively, of CD133-negative IN699 cells became positive using CD133/1. Our data show that a) previously reported CD133- cells may have been misidentified using the glycosylation-specific CD133/1 as constitutive expression of CD133 was detected by the intracellular antibody ab19898; b) hypoxia promotes glycosylation status of CD133, indicating possible involvement of glycosylated CD133 in the process of anti-hypoxia-mediated apoptosis.
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Affiliation(s)
- Kristina S Lehnus
- Cellular and Molecular Neuro-Oncology Research Group, Institute of Biomedical and Biomolecular Science, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK
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