RESUMEN
Prognostic gene expression signatures have been proposed as clinical tools to clarify therapeutic options in acute myeloid leukemia (AML). However, these signatures rely on measuring large numbers of genes and often perform poorly when applied to independent cohorts or those with older patients. Long intergenic non-coding RNAs (lincRNAs) are emerging as important regulators of cell identity and oncogenesis, but knowledge of their utility as prognostic markers in AML is limited. Here we analyze transcriptomic data from multiple cohorts of clinically annotated AML patients and report that (i) microarrays designed for coding gene expression can be repurposed to yield robust lincRNA expression data, (ii) some lincRNA genes are located in close proximity to hematopoietic coding genes and show strong expression correlations in AML, (iii) lincRNA gene expression patterns distinguish cytogenetic and molecular subtypes of AML, (iv) lincRNA signatures composed of three or four genes are independent predictors of clinical outcome and further dichotomize survival in European Leukemia Net (ELN) risk groups and (v) an analytical tool based on logistic regression analysis of quantitative PCR measurement of four lincRNA genes (LINC4) can be used to determine risk in AML.
Asunto(s)
Leucemia Mieloide Aguda/genética , ARN Largo no Codificante/genética , Transcriptoma/genética , Adolescente , Adulto , Femenino , Perfilación de la Expresión Génica/métodos , Humanos , Leucemia Mieloide Aguda/patología , Masculino , Persona de Mediana Edad , Pronóstico , Medición de Riesgo , Factores de Riesgo , Adulto JovenRESUMEN
Heterozygous GATA2 mutations underlie an array of complex hematopoietic and lymphatic diseases. Analysis of the literature reporting three recurrent GATA2 germline (g) mutations (gT354M, gR396Q and gR398W) revealed different phenotype tendencies. Although all three mutants differentially predispose to myeloid malignancies, there was no difference in leukemia-free survival for GATA2 patients. Despite intense interest, the molecular pathogenesis of GATA2 mutation is poorly understood. We functionally characterized a GATA2 mutant allelic series representing major disease phenotypes caused by germline and somatic (s) mutations in zinc finger 2 (ZF2). All GATA2 mutants, except for sL359V, displayed reduced DNA-binding affinity and transactivation compared with wild type (WT), which could be attributed to mutations of arginines critical for DNA binding or amino acids required for ZF2 domain structural integrity. Two GATA2 mutants (gT354M and gC373R) bound the key hematopoietic differentiation factor PU.1 more strongly than WT potentially perturbing differentiation via sequestration of PU.1. Unlike WT, all mutants failed to suppress colony formation and some mutants skewed cell fate to granulocytes, consistent with the monocytopenia phenotype seen in GATA2-related immunodeficiency disorders. These findings implicate perturbations of GATA2 function shaping the course of development of myeloid malignancy subtypes and strengthen complete or nearly complete haploinsufficiency for predisposition to lymphedema.
Asunto(s)
Diferenciación Celular/genética , Factor de Transcripción GATA2/genética , Sistema Hematopoyético/patología , Mutación/genética , Transcripción Genética/genética , Animales , Células COS , Chlorocebus aethiops , Femenino , Predisposición Genética a la Enfermedad/genética , Genotipo , Células HEK293 , Haploinsuficiencia/genética , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , FenotipoAsunto(s)
Mutación de Línea Germinal , Hiperaldosteronismo/genética , Proteínas Supresoras de Tumor/genética , Adulto , Anciano , Proteínas del Dominio Armadillo , Análisis Mutacional de ADN , Femenino , Predisposición Genética a la Enfermedad , Herencia , Humanos , Hiperaldosteronismo/diagnóstico , Masculino , Persona de Mediana Edad , Linaje , Fenotipo , Factores de Riesgo , Secuenciación del ExomaRESUMEN
We describe a novel ERBB1/EGFR somatic mutation (p. C329R; c.985 T > C) identified in a patient with JAK2V617F Polycythaemia Vera (PV). This substitution affects a conserved cysteine residue in EGFR domain 2 and leads to the formation of a ligand-independent covalent receptor dimer, associated with increased transforming potential. Aberrant signalling from the EGFRC329R receptor is cell type-dependent and in the TF1.8 erythroid cell line expression of this mutant suppresses EPO-induced differentiation. Clonal analysis shows that the dominant JAK2V617F-positive clone in this PV patient harbors EGFRC329R, thus this mutation may contribute to clonal expansion. Somatic mutations affecting other ERBB and related receptor tyrosine kinases are observed in myeloproliferative neoplasms (MPN), and we show elevated EGFR levels in MPN samples, consistent with previous reports. Thus activation of this group of receptors, via multiple mechanisms, may contribute to clonal growth and survival of the JAK2V617F disease clone in MPN.
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Janus Quinasa 2/genética , Leucemia Eritroblástica Aguda/genética , Mutación , Policitemia Vera/genética , Mielofibrosis Primaria/genética , Secuencia de Aminoácidos , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Células Clonales , Receptores ErbB/genética , Receptores ErbB/metabolismo , Eritroblastos/efectos de los fármacos , Eritroblastos/metabolismo , Eritroblastos/patología , Eritropoyetina/farmacología , Expresión Génica , Humanos , Janus Quinasa 2/metabolismo , Leucemia Eritroblástica Aguda/metabolismo , Leucemia Eritroblástica Aguda/patología , Policitemia Vera/metabolismo , Policitemia Vera/patología , Mielofibrosis Primaria/metabolismo , Mielofibrosis Primaria/patología , Multimerización de Proteína , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Transducción de SeñalAsunto(s)
Antineoplásicos Inmunológicos/farmacología , Proteínas de Unión al ADN/genética , Diagnóstico Tardío , Fusión Génica , Síndrome Hipereosinofílico/diagnóstico , Mesilato de Imatinib/farmacología , Proteínas Proto-Oncogénicas c-sis/genética , Anciano , Enfermedad Crónica , Humanos , Síndrome Hipereosinofílico/genética , Hibridación Fluorescente in Situ , Masculino , Polimorfismo de Nucleótido SimpleAsunto(s)
Factor de Transcripción GATA2/genética , Mutación de Línea Germinal/genética , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicos/genética , Elementos de Respuesta/genética , Trombocitopenia/genética , Western Blotting , Femenino , Células HEK293 , Humanos , Leucemia Mieloide Aguda/patología , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/patología , Linaje , Trombocitopenia/patologíaRESUMEN
BACKGROUND: BCR-ABL1 mutation analysis is recommended for chronic myeloid leukaemia patients. However, mutations may become undetectable after changing therapy, and it is unknown whether they have been eradicated. METHODS: We examined longitudinal data of patients with imatinib-resistant mutations, which became undetectable by Sanger sequencing to determine whether mutations could reappear, and the related circumstances. RESULTS: Identical imatinib- and nilotinib-resistant mutations reappeared following further therapy changes in five patients, and was associated with subsequent nilotinib resistance in four. CONCLUSION: The data suggest that some BCR-ABL1 mutations may persist at undetectable levels for many years after changing therapy, and can be reselected and confer resistance to subsequent inhibitors.
Asunto(s)
Proteínas de Fusión bcr-abl/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Mutación , Inhibidores de Proteínas Quinasas/farmacología , Adulto , Anciano , Benzamidas/farmacología , Resistencia a Antineoplásicos/genética , Femenino , Humanos , Mesilato de Imatinib , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Piperazinas/farmacología , Pirimidinas/farmacología , Estudios RetrospectivosRESUMEN
CONTEXT: Corticosteroid-binding globulin (CBG; SERPIN A6) gene mutations are rare; only four mutations have been described, often in association with fatigue and chronic pain, albeit with incomplete penetrance. PATIENT: We report a kindred with a novel SERPINA6 mutation. The proband, a 9-yr-old male, had excessive postexertional fatigue, weakness, and migraine. MAIN OUTCOME MEASURES AND RESULTS: Investigations revealed low morning and ACTH-stimulated peak cortisol levels. SERPIN A6 sequencing detected a novel exon 2 single base deletion (c.13delC) leading to a frameshift generating a stop codon within the signal peptide coding region (p.Leu5CysfsX26) and 50% reduced CBG levels in heterozygotes. The patient's father and two sisters share the mutation. Symptom expression within the family may have been modified by a polymorphic CBG allele (c.735G>T). Exogenous hydrocortisone had no effect on the fatigue. CONCLUSION: This report documents the fifth CBG gene mutation in humans and the second causing major effects on CBG levels. Individuals with low CBG levels may be misdiagnosed as having secondary hypocortisolism. The association with fatigue and idiopathic pain is again noted and may relate to altered stress system function. Variability of the phenotype may relate to other genetic variations of the CBG gene or environmental factors.
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Mutación Missense , Transcortina/genética , Secuencia de Aminoácidos , Secuencia de Bases , Niño , Chile , Análisis Mutacional de ADN , Fatiga/complicaciones , Fatiga/genética , Humanos , Masculino , Trastornos Migrañosos/complicaciones , Trastornos Migrañosos/genética , Debilidad Muscular/complicaciones , Debilidad Muscular/genética , Linaje , Polimorfismo de Nucleótido SimpleAsunto(s)
Trastornos de las Plaquetas Sanguíneas/genética , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Leucemia Mieloide Aguda/genética , Mutación , Trastornos de las Plaquetas Sanguíneas/diagnóstico , Niño , Preescolar , Femenino , Eliminación de Gen , Humanos , Leucemia Mieloide Aguda/diagnóstico , MasculinoRESUMEN
Expression of the autoimmune regulator gene (AIRE) and the presence of CD25(+)/forkhead box p3 (FoxP3)(+) T regulatory (T(reg)) cells were investigated in histologically normal adult thymi and in thymomas using immunohistochemistry and quantitative real-time polymerase chain reaction (PCR). In the normal thymus staining for AIRE was detected in the nucleus of some epithelial-like cells located in the medulla; in thymomas AIRE-positive cells were extremely rare and could be detected only in the areas of medullary differentiation of two B1 type, organoid thymomas. RNA was extracted from 36 cases of thymoma and 21 non-neoplastic thymi obtained from 11 myasthenic (MG(+)) and 10 non-myasthenic (MG(-)) patients. It was found that AIRE is 8.5-fold more expressed in non-neoplastic thymi than in thymomas (P = 0.01), and that the amount of AIRE transcripts present in the thymoma tissue are not influenced by the association with MG, nor by the histological type. A possible involvement of AIRE in the development of MG was suggested by the observation that medullary thymic epithelial cells isolated from AIRE-deficient mice contain low levels of RNA transcripts for CHRNA 1, a gene coding for acetylcholine receptor. Expression of human CHRNA 1 RNA was investigated in 34 human thymomas obtained from 20 MG(-) patients and 14 MG(+) patients. No significant difference was found in the two groups (thymoma MG(+), CHRNA1 = 0.013 +/- 0.03; thymoma MG-, CHRNA1 = 0.01 +/- 0.03). In normal and hyperplastic thymi CD25(+)/Foxp3(+) cells were located mainly in the medulla, and their number was not influenced by the presence of MG. Foxp3(+) and CD25(+) cells were significantly less numerous in thymomas. A quantitative estimate of T(reg) cells revealed that the levels of Foxp3 RNA detected in non-neoplastic thymi were significantly higher (P = 0.02) than those observed in 31 cases of thymomas. Our findings indicate that the tissue microenvironment of thymomas is defective in the expression of relevant functions that exert a crucial role in the negative selection of autoreactive lymphocytes.
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Linfocitos T Reguladores/inmunología , Timoma/inmunología , Neoplasias del Timo/inmunología , Factores de Transcripción/metabolismo , Adulto , Anciano , Femenino , Factores de Transcripción Forkhead/metabolismo , Humanos , Técnicas para Inmunoenzimas , Masculino , Persona de Mediana Edad , Miastenia Gravis/inmunología , Reacción en Cadena de la Polimerasa/métodos , Timo/inmunología , Factores de Transcripción/genética , Proteína AIREAsunto(s)
Proteínas de Unión al ADN/genética , Leucemia Mieloide/etiología , Factores de Transcripción/genética , Enfermedad Aguda , Cromosomas Humanos Par 16 , Análisis Mutacional de ADN , Proteínas de Unión al ADN/fisiología , Salud de la Familia , Humanos , Leucemia Mieloide/genética , Factor de Transcripción AP-2 , Factores de Transcripción/fisiologíaRESUMEN
Progressive myoclonus epilepsy 1 (EPM1) or Unverricht-Lundborg disease is a human autosomal recessive neurodegenerative disorder caused by mutations in cystatin B (CSTB). The CSTB gene maps to human chromosome 21 and encodes an inhibitor of lysosomal cysteine proteases. Five point mutations have been found, two of which are seen in numerous unrelated patients. However, the main CSTB mutation in EPM1, even among patients of different ethnic origins, is an expansion of a dodecamer repeat (CCCCGCCCCGCG) in the 5' flanking area of CSTB. Most normal alleles contain either two or three repeats, while rarer normal alleles that are highly unstable contain between 12 and 17 repeats. Mutant expanded alleles have been reported to contain between 30 and 80 copies and are also highly unstable, particularly via parental transmission. There is no apparent correlation between mutant repeat length and disease phenotype. While the repeat expansion is outside the CSTB transcriptional unit, it results in a marked decrease in CSTB expression, at least in certain cell types in vitro. CSTB homozygous knockout mice show some parallels to the phenotype of human EPM1 including myoclonic seizures, development of ataxia and neuropathological changes associated with cell loss via apoptosis. Loss of CSTB function due to mutations is consistent with the observed neurodegenerative pathology and phenotype, but the functional link to the epileptic phenotype of EPM1 remains largely unknown.
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Cistatinas/genética , Expansión de las Repeticiones de ADN/genética , Repeticiones de Minisatélite/genética , Epilepsias Mioclónicas Progresivas/genética , Secuencia de Bases , Cistatina B , Inhibidores de Cisteína Proteinasa/genética , Salud de la Familia , Femenino , Regulación de la Expresión Génica , Humanos , Masculino , Mutación , Epilepsias Mioclónicas Progresivas/patología , Linaje , Polimorfismo GenéticoRESUMEN
Trisomy 21, which causes Down syndrome, is the model human disorder due to the presence of a supernumerary chromosome. The completion of the sequence of chromosome 21 and the development of appropriate animal models now provide the molecular infrastructure and the reagents to elucidate the molecular mechanisms of the different phenotypes of Down syndrome. The study of the overexpression of single genes, and the dysregulation of global gene expression will enhance the understanding of the pathogenesis of the cognitive impairment of this syndrome.
Asunto(s)
Encéfalo/anomalías , Cromosomas Humanos Par 21/genética , Síndrome de Down/genética , Síndrome de Down/fisiopatología , Regulación del Desarrollo de la Expresión Génica/fisiología , Animales , Secuencia de Bases/fisiología , Encéfalo/patología , Encéfalo/fisiopatología , Modelos Animales de Enfermedad , Humanos , Ratones , Ratones Mutantes Neurológicos/anomalías , Ratones Mutantes Neurológicos/genética , Ratones Mutantes Neurológicos/metabolismo , FenotipoRESUMEN
Autoimmune polyendocrinopathy candidiasis-ectodermal dystrophy (APECED) is a rare recessively inherited disorder caused by mutations in the AIRE (autoimmune regulator) gene. APECED is characterized by variable combinations of endocrine autoimmune diseases such as Addison's disease, hypoparathyroidism, and type 1 diabetes. The AIRE protein contains motifs suggestive of a transcription regulator and can activate transcription of a reporter gene when fused to a heterologous DNA biding domain. In this article, mutation analyses of over 200 APECED patients published by several laboratories are summarized. To date 42 different mutations have been identified. These mutations include nonsense and missense mutations, small insertions and deletions leading into frame shifts, and splice site mutations. Although mutations are spread throughout the coding region of the gene some hotspots emerge, including the more common and recurrent mutations R257X and 967-979del13bp. Some of the identified mutations have been shown to affect subcellular localization or transactivation properties of the protein, thus providing insights into the functional properties of the predicted protein motifs.
Asunto(s)
Mutación/genética , Poliendocrinopatías Autoinmunes/genética , Factores de Transcripción/genética , Humanos , Proteína AIRERESUMEN
Recently the TMPRSS3 gene, which encodes a transmembrane serine protease, was found to be responsible for two non-syndromic recessive deafness loci located on human chromosome 21q22.3, DFNB8 and DFNB10. We found evidence for linkage to the DFNB8/10 locus in two unrelated consanguineous Tunisian families segregating congenital autosomal recessive sensorineural deafness. The audiometric tests showed a loss of hearing greater than 70 dB, in all affected individuals of both families. Mutation screening of TMPRSS3 revealed two novel missense mutations, W251C and P404L, altering highly conserved amino acids of the serine protease domain. Both mutations were not found in 200 control Tunisian chromosomes. The detection of naturally-occurring TMPRSS3 missense mutations in deafness families identifies functionally important amino acids. Comparative protein modeling of the TMPRSS3 protease domain predicted that W251C might lead to a structural rearrangement affecting the active site H257 and that P404L might alter the geometry of the active site loop and therefore affect the serine protease activity.
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Pérdida Auditiva Sensorineural/genética , Proteínas de la Membrana , Mutación Missense/genética , Proteínas de Neoplasias , Serina Endopeptidasas/genética , Secuencia de Aminoácidos , Audiometría , Secuencia de Bases , Sitios de Unión , Mapeo Cromosómico , Cromosomas Humanos Par 21/genética , Consanguinidad , Secuencia Conservada/genética , Análisis Mutacional de ADN , Femenino , Genes Recesivos/genética , Ligamiento Genético/genética , Genotipo , Pérdida Auditiva Sensorineural/congénito , Humanos , Masculino , Modelos Moleculares , Datos de Secuencia Molecular , Linaje , Estructura Terciaria de Proteína , Serina Endopeptidasas/química , TúnezRESUMEN
In order to identify candidate genes for Down syndrome phenotypes or monogenic disorders that map to human chromosome 21q22.3, we have used genomic sequence and expressed sequence tags mapping to an autosomal recessive deafness (DFNB10) critical region to isolate a novel 2.5-kb cDNA that maps between TFF1 and D21S49. A semi-quantitative reverse transcription/polymerase chain reaction method revealed that UBASH3A gene expression is limited to only a few tissues, with its highest expression in spleen, peripheral blood leukocytes, and bone marrow. The putative 661-amino-acid protein shows considerable homology to a hypothetical protein from Drosophila melanogaster but only domain homologies to other organisms. Both the human and D. melanogaster proteins contain protein-protein interaction domains, viz., SH3 and ubiquitin-associated (UBA) domains, in addition to a novel domain also containing a nuclear localization signal. This is the first protein described containing both UBA and SH3 domains. The gene, thus called UBASH3A, spans 40 kb and is divided into 15 exons. Mutation analysis excluded UBASH3A as being responsible for DFNB10.