RESUMO
Demethylation of FOXP3-TSDR (Treg specific demethylated region) is a hallmark of stable differentiation and suppressive function of regulatory T (Treg) cells. Previous protocols aiming at human naïve T cell differentiation failed to implement a Treg cell specific epigenetic signature. Ten-eleven translocation (TET) enzymes catalyze DNA demethylation. Plasmids towardexpression of a fusion protein encompassing nonfunctional Cas9, the catalytic domain of TET1, blue fluorescent protein, and encoding single guide RNAs (sgRNAs) targeting specific segments of the FOXP3-TSDR were engineered and transfected into Jurkat T cells. FOXP3-TSDR methylation was analyzed by deep-amplicon bisulfite sequencing while cellular Foxp3, Tbet, Gata3, and Rorgt mRNA levels were determined by real-time PCR. Overexpression of dCas9TET1 significantly decreased Jurkat cell FOXP3-TSDR methylation and increased Foxp3 mRNA expression while expressions of master transcription factor mRNAs of other major T cell lineages remained largely unaffected. dCas9-TET1 construct transfection mediated Treg programming of patients' primary T cells might be feasible.
Assuntos
Sistemas CRISPR-Cas/genética , Metilação de DNA/genética , Fatores de Transcrição Forkhead/metabolismo , Edição de Genes/métodos , Oxigenases de Função Mista/genética , Proteínas Proto-Oncogênicas/genética , Linfócitos T Reguladores/citologia , Proteína 9 Associada à CRISPR/genética , Diferenciação Celular/imunologia , Linhagem Celular Tumoral , Desmetilação , Fatores de Transcrição Forkhead/genética , Fator de Transcrição GATA3/genética , Humanos , Células Jurkat , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , RNA Guia de Cinetoplastídeos/genética , RNA Mensageiro/genética , Linfócitos T Reguladores/imunologiaRESUMO
A human cell line of neuroblastic tissue, which was believed to have been lost to science due to its unavailability in public repositories, is revived and reclassified. In the 1970s, a triple set of neuroblastoma (NB) cell lines became available for research as MYCN-amplified vs nonamplified models (CHP-126/-134 and CHP-100, respectively). Confusingly, CHP-100 was used in subsequent years as a model for NB and, since the 1990s, as a model for neuroepithelioma and later as a model for Ewing's sarcoma (ES), which inevitably led to non-reproducible results. A deposit at a bioresource center revealed that globally available stocks of CHP-100 were identical to the prominent NB cell line IMR-32 and CHP-100 was included into the list of misidentified cell lines. Now we report on the rediscovery of an authentic CHP-100 cell line and provide evidence of incorrect classification during establishment. We show that CHP-100 cells carry a t(11;22)(q24;q12) type II EWSR1-FLI1 fusion and identify it as a classic ES. Although the question of whether CHP-100 was a virtual and never existing cell line from the beginning is now clarified, the results of all relevant publications should be considered questionable. Neither the time of the cross-contamination event with IMR-32 is known nor was the final classification as a model for Ewing family of tumors available with an associated short tandem repeat profile. After a long road of errors and confusion, authentic CHP-100 is now characterized as a type II EWSR1-FLI1 fusion model 44 years after its establishment.
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Mutations in components of the major spliceosome have been described in disorders with craniofacial anomalies, e.g., Nager syndrome and mandibulofacial dysostosis type Guion-Almeida. The U5 spliceosomal complex of eight highly conserved proteins is critical for pre-mRNA splicing. We identified biallelic mutations in TXNL4A, a member of this complex, in individuals with Burn-McKeown syndrome (BMKS). This rare condition is characterized by bilateral choanal atresia, hearing loss, cleft lip and/or palate, and other craniofacial dysmorphisms. Mutations were found in 9 of 11 affected families. In 8 families, affected individuals carried a rare loss-of-function mutation (nonsense, frameshift, or microdeletion) on one allele and a low-frequency 34 bp deletion (allele frequency 0.76%) in the core promoter region on the other allele. In a single highly consanguineous family, formerly diagnosed as oculo-oto-facial dysplasia, the four affected individuals were homozygous for a 34 bp promoter deletion, which differed from the promoter deletion in the other families. Reporter gene and in vivo assays showed that the promoter deletions led to reduced expression of TXNL4A. Depletion of TXNL4A (Dib1) in yeast demonstrated reduced assembly of the tri-snRNP complex. Our results indicate that BMKS is an autosomal-recessive condition, which is frequently caused by compound heterozygosity of low-frequency promoter deletions in combination with very rare loss-of-function mutations.
Assuntos
Atresia das Cóanas/genética , Surdez/congênito , Deleção de Genes , Cardiopatias Congênitas/genética , Regiões Promotoras Genéticas/genética , Ribonucleoproteína Nuclear Pequena U5/genética , Spliceossomos/genética , Alelos , Pré-Escolar , Atresia das Cóanas/diagnóstico , Surdez/diagnóstico , Surdez/genética , Exossomos/genética , Fácies , Feminino , Perfilação da Expressão Gênica , Frequência do Gene , Genes Reporter , Cardiopatias Congênitas/diagnóstico , Heterozigoto , Homozigoto , Humanos , Masculino , Mutação , Análise de Sequência com Séries de Oligonucleotídeos , Linhagem , Fenótipo , Ribonucleoproteína Nuclear Pequena U5/metabolismo , Análise de Sequência de DNA , Spliceossomos/metabolismoRESUMO
BACKGROUND: Retinoblastoma is the most common malignant cancer of the eye in children. Although metastatic retinoblastoma is rare, cure rates for this advanced disease remain below 50%. High-level polo-like kinase 1 expression in retinoblastomas has previously been shown to be correlated with adverse outcome parameters. Polo-like kinase 1 is a serine/threonine kinase involved in cell cycle regulation at the G2/M transition. Polo-like kinase 1 inhibition has been demonstrated to have anti-tumour effects in preclinical models of several paediatric tumours. Here, we assessed its efficacy against retinoblastoma cell lines. METHODS: Expression of polo-like kinase 1 was determined in a panel of retinoblastoma cell lines by polymerase chain reaction and western blot analysis. We analysed viability (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT assay), proliferation (5-bromo-2'-deoxyuridine enzyme-linked immunosorbent assay), cell cycle progression (propidium iodid staining) and apoptosis (cell death enzyme-linked immunosorbent assay) in three retinoblastoma cell lines after treatment with two adenosine triphosphate-competitive polo-like kinase 1 inhibitors, BI6727 or GSK461364. Activation of polo-like kinase 1 downstream signalling components including TP53 were assessed. RESULTS: Treatment of retinoblastoma cells with either BI6727 or GSK461364 reduced cell viability and proliferative capacity and induced both cell cycle arrest and apoptosis. Polo-like kinase 1 inhibition also induced the p53 signalling pathway. Analysis of key players in cell cycle control revealed that low nanomolar concentrations of either polo-like kinase 1 inhibitor upregulated cyclin B1 and increased activated cyclin-dependent kinase 1 (phosphorylated at Y15) in retinoblastoma cell lines. CONCLUSIONS: These preclinical data indicate that polo-like kinase 1 inhibitors could be useful as components in rationally designed chemotherapy protocols to treat patients with metastasized retinoblastoma in early phase clinical trials.
Assuntos
Antineoplásicos/farmacologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Neoplasias da Retina/patologia , Retinoblastoma/patologia , Apoptose/efeitos dos fármacos , Benzimidazóis/farmacologia , Western Blotting , Proteína Quinase CDC2 , Ciclo Celular/efeitos dos fármacos , Proteínas de Ciclo Celular/genética , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ciclina B1/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Humanos , Fosforilação , Reação em Cadeia da Polimerase , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Pteridinas/farmacologia , Reação em Cadeia da Polimerase em Tempo Real , Neoplasias da Retina/genética , Neoplasias da Retina/metabolismo , Retinoblastoma/genética , Retinoblastoma/metabolismo , Tiofenos/farmacologia , Células Tumorais Cultivadas , Quinase 1 Polo-LikeRESUMO
The neurodevelopmental disorder Angelman syndrome (AS) has an incidence of 1:15.000 live births and is caused by absence of UBE3A protein, showing imprinted gene expression in the brain. Imprinted genes are controlled by differentially methylated regions resulting in parent-of-origin dependent gene expression. Two iPS cell lines derived from patients with AS and one healthy control iPSC line were used to integrate a 3rd generation reverse tetracycline transactivator protein (rtTA3) into the AAVS1 locus on chromosome 19. The rtTA allows tetracycline-dependent activation of an inducible promoter that can be introduced at a position of interest in the cell lines described here.
Assuntos
Síndrome de Angelman , Células-Tronco Pluripotentes Induzidas , Células-Tronco Pluripotentes Induzidas/metabolismo , Síndrome de Angelman/genética , Humanos , Linhagem CelularRESUMO
Continuous cell lines are important and commonly used in vitro models in breast cancer (BC) research. Selection of the appropriate model cell line is crucial and requires consideration of their molecular characteristics. To characterize BC cell line models in depth, we profiled a panel of 29 authenticated and publicly available BC cell lines by mRNA-sequencing, mutation analysis, and immunoblotting. Gene expression profiles separated BC cell lines in two major clusters that represent basal-like (mainly triple-negative BC) and luminal BC subtypes, respectively. HER2-positive cell lines were located within the luminal cluster. Mutation calling highlighted the frequent aberration of TP53 and BRCA2 in BC cell lines, which, therefore, share relevant characteristics with primary BC. Furthermore, we showed that the data can be used to find novel, potential oncogenic fusion transcripts, e.g., FGFR2::CRYBG1 and RTN4IP1::CRYBG1 in cell line MFM-223, and to elucidate the regulatory circuit of IRX genes and KLF15 as novel candidate tumor suppressor genes in BC. Our data indicated that KLF15 was activated by IRX1 and inhibited by IRX3. Moreover, KLF15 inhibited IRX1 in cell line HCC-1599. Each BC cell line carries unique molecular features. Therefore, the molecular characteristics of BC cell lines described here might serve as a valuable resource to improve the selection of appropriate models for BC research.
Assuntos
Neoplasias da Mama , Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Feminino , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Mama/metabolismo , Proteínas de Transporte , Proteínas Mitocondriais/metabolismoRESUMO
Retinoblastoma are childhood eye tumors arising from retinal precursor cells. Two distinct retinoblastoma subtypes with different clinical behavior have been described based on gene expression and methylation profiling. Using consensus clustering of DNA methylation analysis from 61 retinoblastomas, we identify a MYCN-driven cluster of subtype 2 retinoblastomas characterized by DNA hypomethylation and high expression of genes involved in protein synthesis. Subtype 2 retinoblastomas outside the MYCN-driven cluster are characterized by high expression of genes from mesodermal development, including NKX2-5. Knockdown of MYCN expression in retinoblastoma cell models causes growth arrest and reactivates a subtype 1-specific photoreceptor signature. These molecular changes suggest that removing the driving force of MYCN oncogenic activity rescues molecular circuitry driving subtype 1 biology. The MYCN-RB gene signature generated from the cell models better identifies MYCN-driven retinoblastoma than MYCN amplification and can identify cases that may benefit from MYCN-targeted therapy. MYCN drives tumor progression in a molecularly defined retinoblastoma subgroup, and inhibiting MYCN activity could restore a more differentiated and less aggressive tumor biology.
Assuntos
Proteína Proto-Oncogênica N-Myc , Retinoblastoma , Humanos , Retinoblastoma/genética , Retinoblastoma/patologia , Proteína Proto-Oncogênica N-Myc/genética , Proteína Proto-Oncogênica N-Myc/metabolismo , Metilação de DNA , Neoplasias da Retina/genética , Neoplasias da Retina/patologia , Neoplasias da Retina/metabolismo , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral , Desdiferenciação Celular/genética , Feminino , Masculino , Pré-EscolarRESUMO
The Airn macro ncRNA is the master regulator of imprinted expression in the Igf2r imprinted gene cluster where it silences three flanking genes in cis. Airn transcription shows unusual features normally viewed as promoter specific, such as impaired post-transcriptional processing and a macro size. The Airn transcript is 108 kb long, predominantly unspliced and nuclear localized, with only a minority being variably spliced and exported. Here, we show by deletion of the Airn ncRNA promoter and replacement with a constitutive strong or weak promoter that splicing suppression and termination, as well as silencing activity, are maintained by strong Airn expression from an exogenous promoter. This indicates that all functional regions are located within the Airn transcript. DNA methylation of the maternal imprint control element (ICE) restricts Airn expression to the paternal allele and we also show that a strong active promoter is required to maintain the unmethylated state of the paternal ICE. Thus, Airn expression not only induces silencing of flanking mRNA genes but also protects the paternal copy of the ICE from de novo methylation.
Assuntos
Inativação Gênica , Regiões Promotoras Genéticas , RNA não Traduzido/genética , Transcrição Gênica , Células Cultivadas , Metilação de DNA , Expressão Gênica , Humanos , Família Multigênica , Deleção de SequênciaRESUMO
Because of the diversity of clinical symptoms, the diagnosis of mitochondrial DNA (mtDNA) deletion disorders can be difficult. Here, we describe an 8-month-old boy presenting clinically exclusively with refractory anemia. Mutation analysis in our patient revealed a large, novel deletion in his mtDNA encompassing ATPase 6, cytochrome oxidase subunit III, NADH dehydrogenase genes ND3 to ND6, and cytochrome b. Comparison with other cases from the literature showed that there is no genotype-phenotype correlation regarding hematologic features. It is not possible to predict whether our patient will develop additional features from Pearson syndrome or Kearns-Sayre syndrome, both syndromic mitochondrial disorders with hematological manifestations.
Assuntos
Anemia Refratária/genética , Anemia Sideroblástica/genética , DNA Mitocondrial/genética , Síndrome de Kearns-Sayre/genética , Doenças Mitocondriais/genética , Deleção de Sequência , Acil-CoA Desidrogenase de Cadeia Longa/deficiência , Síndrome Congênita de Insuficiência da Medula Óssea , Análise Mutacional de DNA , Humanos , Lactente , Erros Inatos do Metabolismo Lipídico , Masculino , Proteínas Mitocondriais/genética , Doenças MuscularesRESUMO
Human and animal cell lines serve as model systems in a wide range of life sciences such as cancer and infection research or drug screening. Reproducible data are highly dependent on authenticated, contaminant-free cell lines, no better delivered than by the official and certified biorepositories. Offering a web portal to high-throughput information on these model systems will facilitate working with and comparing to these references by data otherwise dispersed at different sources. We here provide DSMZCellDive to access a comprehensive data source on human and animal cell lines, freely available at celldive.dsmz.de. A wide variety of data sources are generated such as RNA-seq transcriptome data and STR (short tandem repeats) profiles. Several starting points ease entering the database via browsing, searching or visualising. This web tool is designed for further expansion on meta and high-throughput data to be generated in future. Explicated examples for the power of this novel tool include analysis of B-cell differentiation markers, homeo-oncogene expression, and measurement of genomic loss of heterozygosities by an enlarged STR panel of 17 loci. Sharing the data on cell lines by the biorepository itself will be of benefit to the scientific community since it (1) supports the selection of appropriate model cell lines, (2) ensures reliability, (3) avoids misleading data, (4) saves on additional experimentals, and (5) serves as reference for genomic and gene expression data.
Assuntos
Repetições de Microssatélites , Neoplasias , Animais , Linhagem Celular , Humanos , Neoplasias/genética , Reprodutibilidade dos Testes , TranscriptomaRESUMO
Retinoblastoma is a tumor of the eye in children under the age of five caused by biallelic inactivation of the RB1 tumor suppressor gene in maturing retinal cells. Cancer models are essential for understanding tumor development and in preclinical research. Because of the complex organization of the human retina, such models were challenging to develop for retinoblastoma. Here, we present an organoid model based on differentiation of human embryonic stem cells into neural retina after inactivation of RB1 by CRISPR/Cas9 mutagenesis. Wildtype and RB1 heterozygous mutant retinal organoids were indistinguishable with respect to morphology, temporal development of retinal cell types and global mRNA expression. However, loss of pRB resulted in spatially disorganized organoids and aberrant differentiation, indicated by disintegration of organoids beyond day 130 of differentiation and depletion of most retinal cell types. Only cone photoreceptors were abundant and continued to proliferate, supporting these as candidate cells-of-origin for retinoblastoma. Transcriptome analysis of RB1 knockout organoids and primary retinoblastoma revealed gain of a retinoblastoma expression signature in the organoids, characterized by upregulation of RBL1 (p107), MDM2, DEK, SYK and HELLS. In addition, genes related to immune response and extracellular matrix were specifically upregulated in RB1-negative organoids. In vitro retinal organoids therefore display some features associated with retinoblastoma and, so far, represent the only valid human cancer model for the development of this disease.
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The SARS-CoV-2 pandemic is a major global threat that sparked global research efforts. Pre-clinical and biochemical SARS-CoV-2 studies firstly rely on cell culture experiments where the importance of choosing an appropriate cell culture model is often underestimated. We here present a bottom-up approach to identify suitable permissive cancer cell lines for drug screening and virus research. Human cancer cell lines were screened for the SARS-CoV-2 cellular entry factors ACE2 and TMPRSS2 based on RNA-seq data of the Cancer Cell Line Encyclopedia (CCLE). However, experimentally testing permissiveness towards SARS-CoV-2 infection, we found limited correlation between receptor expression and permissiveness. This underlines that permissiveness of cells towards viral infection is determined not only by the presence of entry receptors but is defined by the availability of cellular resources, intrinsic immunity, and apoptosis. Aside from established cell culture infection models CACO-2 and CALU-3, three highly permissive human cell lines, colon cancer cell lines CL-14 and CL-40 and the breast cancer cell line CAL-51 and several low permissive cell lines were identified. Cell lines were characterised in more detail offering a broader choice of non-overexpression in vitro infection models to the scientific community. For some cell lines a truncated ACE2 mRNA and missense variants in TMPRSS2 might hint at disturbed host susceptibility towards viral entry.
Assuntos
COVID-19/virologia , Receptores Virais , SARS-CoV-2/fisiologia , Internalização do Vírus , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/metabolismo , Linhagem Celular Tumoral , Humanos , Receptores Virais/genética , Receptores Virais/metabolismo , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismoRESUMO
Retinoblastoma is a childhood tumor of the retina that is caused mostly by biallelic inactivation of the tumor suppressor gene RB1. To generate a research resource, we abrogated expression of RB1 in H9 hESCs by CRISPR/Cas9 induced deletion of the RB1 promoter, either on one or on both alleles. This enables studies on the role of RB1 loss during differentiation, for example in differentiation towards neural retina. The generation of three isogenic lines per deletion state enables validation of phenotypic results in independent clonal lines.
Assuntos
Células-Tronco Embrionárias Humanas , Neoplasias da Retina , Retinoblastoma , Criança , Células-Tronco Embrionárias Humanas/metabolismo , Humanos , Regiões Promotoras Genéticas/genética , Neoplasias da Retina/genética , Retinoblastoma/genética , Proteínas de Ligação a Retinoblastoma/genética , Proteína do Retinoblastoma/genética , Ubiquitina-Proteína Ligases/genéticaRESUMO
Structures resembling whole organs, called organoids, are generated using pluripotent stem cells and 3D culturing methods. This relies on the ability of cells to self-reorganize after dissociation. In combination with certain supplemented factors, differentiation can be directed toward the formation of several organ-like structures. Here, a protocol for the generation of retinal organoids containing all seven retinal cell types is described. This protocol does not depend on Matrigel, and by keeping the organoids single and independent at all times, fusion is prevented and monitoring of differentiation is improved. Comprehensive phenotypic characterization of the in vitro-generated retinal organoids is achieved by the protocol for immunostaining outlined here. By comparing different stages of retinal organoids, the decrease and increase of certain cell populations can be determined. In order to be able to detect even small differences, it is necessary to quantify the immunofluorescent signals, for which we have provided a detailed protocol describing signal quantitation using the image-processing program Fiji. © 2020 The Authors. Basic Protocol 1: Differentiation protocol for 3D retinal organoids Basic Protocol 2: Immunostaining protocol for cryosections of retinal organoids Support Protocol: Embedding and sectioning protocol for 3D retinal organoids Basic Protocol 3: Quantitation protocol using Fiji.
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Organoides/citologia , Retina/citologia , Técnicas de Cultura de Tecidos , Diferenciação Celular , Células-Tronco Embrionárias , HumanosRESUMO
Transcriptional interference and transcription through regulatory elements (transcriptional read-through) are implicated in gene silencing and the establishment of DNA methylation. Transcriptional read-through is needed to seed DNA methylation at imprinted genes in the germ line and can lead to aberrant gene silencing by DNA methylation in human disease. To enable the study of parameters and factors influencing transcriptional interference and transcriptional read-through at human promoters, we established a somatic cell culture system. At two promoters of imprinted genes (UBE3A and SNRPN) and two promoters shown to be silenced by aberrant transcriptional read-through in human disease (MSH2 and HBA2) we tested, if transcriptional read-through is sufficient for gene repression and the acquisition of DNA methylation. Induction of transcriptional read-through from the doxycycline-inducible CMV promoter resulted in consistent repression of all downstream promoters, independent of promoter type and orientation. Repression was dependent on ongoing transcription, since withdrawal of induction resulted in reactivation. DNA methylation was not acquired at any of the promoters. Overexpression of DNMT3A and DNMT3L, factors needed for DNA methylation establishment in oocytes, was still not sufficient for the induction of DNA methylation. This indicates that induction of DNA methylation has more complex requirements than transcriptional read-through and the presence of de novo DNA methyltransferases.
RESUMO
Biallelic inactivation of the retinoblastoma tumor suppressor gene (RB1) causes formation of retinoblastoma, a retinal eye tumor occurring in early childhood. Using the CRISPR/Cas9 nickase system, exon 1 of RB1 was deleted, including the RB1 promoter. As a result, sublines were generated carrying deletions of RB1 exon 1/promoter on one or both alleles.
Assuntos
Éxons/genética , Regiões Promotoras Genéticas/genética , Retinoblastoma/genética , Alelos , Sistemas CRISPR-Cas/genética , Imunofluorescência , Heterozigoto , Humanos , Cariotipagem , Masculino , Repetições de Microssatélites/genética , Proteínas de Ligação a Retinoblastoma/genética , Ubiquitina-Proteína Ligases/genéticaRESUMO
Familial Adult Myoclonic Epilepsy (FAME) is a genetically heterogeneous disorder characterized by cortical tremor and seizures. Intronic TTTTA/TTTCA repeat expansions in SAMD12 (FAME1) are the main cause of FAME in Asia. Using genome sequencing and repeat-primed PCR, we identify another site of this repeat expansion, in MARCH6 (FAME3) in four European families. Analysis of single DNA molecules with nanopore sequencing and molecular combing show that expansions range from 3.3 to 14 kb on average. However, we observe considerable variability in expansion length and structure, supporting the existence of multiple expansion configurations in blood cells and fibroblasts of the same individual. Moreover, the largest expansions are associated with micro-rearrangements occurring near the expansion in 20% of cells. This study provides further evidence that FAME is caused by intronic TTTTA/TTTCA expansions in distinct genes and reveals that expansions exhibit an unexpectedly high somatic instability that can ultimately result in genomic rearrangements.
Assuntos
Expansão das Repetições de DNA , Epilepsias Mioclônicas/genética , Proteínas de Membrana/genética , Ubiquitina-Proteína Ligases/genética , Adolescente , Adulto , Idoso , Mapeamento Cromossômico , Feminino , Humanos , Íntrons , Masculino , Pessoa de Meia-Idade , Linhagem , Adulto JovemRESUMO
Inactivation of the tumor suppressor gene RB1 is causal for development of retinoblastoma, a tumor of the neural retina arising in children under the age of five. In addition, secondary RB1 mutations are found in many other tumor types. To investigate retinoblastoma formation in vitro, stem cells with inactivated RB1 can be differentiated into neural retina. To enable such studies, two sublines of hESC line H9 carrying mutations in RB1 exon 3 in heterozygous or homozygous state were generated and characterized. Homozygous mutation led to loss of RB1 protein expression. Resource table.
Assuntos
Proteína do Retinoblastoma/genética , Retinoblastoma/genética , Heterozigoto , Homozigoto , Humanos , MutaçãoRESUMO
Angelman syndrome (AS) is a neurodevelopmental disorder with leading symptoms of happy demeanor, intellectual disability, ataxia and seizures. AS can be caused by genetic and epigenetic aberrations, resulting in the absence of functional UBE3A protein in the brain. UBE3A is an imprinted gene, which is, in neurons of the brain, expressed exclusively from maternal chromosome 15. The generated iPSC line was derived from skin fibroblasts of a patient with AS, who, due to an imprinting defect, lacked DNA methylation at the chromosome 15 imprinting center, which controls maternal-specific expression of UBE3A. Resource table.
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Síndrome de Angelman/genética , Impressão Genômica/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Criança , Feminino , HumanosRESUMO
Two isogenic hiPSC lines, ZIPi013-B and ZIPi013-E, were generated by reprogramming fetal dermal fibroblasts with episomal vectors. Previously, the same fetal fibroblasts were reprogrammed multiple times in a study comparing other reprogramming methods. As a consequence, the genomes have been sequenced multiple times. Both new cell lines offer the opportunity to study basic stem cell biology and model human disease. They can be applied as reference cell lines for creating isogenic clones bearing disease mutations on a well-characterized genomic background, as both cell lines have demonstrated excellent differentiation capacity in multiple labs. Resource table.