RESUMEN
The recurrent translocation t(5;11)(q35;p15.5) associated with a 5q deletion, del(5q), has been reported in childhood acute myeloid leukemia (AML). We report the cloning of the translocation breakpoints in de novo childhood AML harboring a cryptic t(5;11)(q35;p15.5). Fluorescence in situ hybridization (FISH) analysis demonstrated that the nucleoporin gene (NUP98) at 11p15.5 was disrupted by this translocation. By using 3'--rapid amplification of complementary DNA ends (3'-RACE) polymerase chain reaction, we identified a chimeric messenger RNA that results in the in-frame fusion of NUP98 to a novel gene, NSD1. The NSD1 gene has 2596 amino acid residues and a 85% homology to the murine Nsd1 with the domain structure being conserved. The NSD1 gene was localized to 5q35 by FISH and is widely expressed. The reciprocal transcript, NSD1-NUP98, was also detected by reverse transcriptase--polymerase chain reaction. This is the first report in which the novel gene NSD1 has been implicated in human malignancy. (Blood. 2001;98:1264-1267)
Asunto(s)
Proteínas Portadoras/genética , Cromosomas Humanos Par 11 , Cromosomas Humanos Par 5 , Péptidos y Proteínas de Señalización Intracelular , Leucemia Mieloide/genética , Proteínas de la Membrana/genética , Proteínas de Complejo Poro Nuclear , Proteínas Nucleares/genética , Translocación Genética , Enfermedad Aguda , Secuencia de Bases , Niño , Análisis Citogenético , Histona Metiltransferasas , N-Metiltransferasa de Histona-Lisina , Humanos , Leucemia Mieloide/etiología , Datos de Secuencia MolecularRESUMEN
The 5q- syndrome is a distinct subtype of myelodysplastic syndrome (MDS) characterized by refractory anemia, deletion of the long arm of chromosome 5, del(5q), as the sole cytogenetic abnormality, and a low frequency of transformation to acute leukemia. Using combined immunophenotyping and fluorescence in situ hybridization (FISH), studies were carried out on bone marrow smears of three 5q- syndrome cases to identify the cell lineages carrying the 5q deletion. In all three cases, the granulocytic, monocytic, and erythroid lineages possessed the del(5q) clonal marker, whereas the T-lymphocytes did not. Interestingly, in one case, cells of B-lymphoid lineage also showed the presence of the del(5q). This is the first report to date showing involvement of an acquired 5q deletion associated with MDS in B-cells. This result suggests that in some cases, MDS arises in a multipotent cell with a capacity to differentiate into both myeloid and lymphoid cells.
Asunto(s)
Anemia Refractaria/patología , Linfocitos B/patología , Deleción Cromosómica , Cromosomas Humanos Par 5/genética , Inmunofenotipificación , Hibridación Fluorescente in Situ , Síndromes Mielodisplásicos/genética , Síndromes Mielodisplásicos/patología , Adulto , Anciano , Anemia Refractaria/diagnóstico , Anemia Refractaria/genética , Biomarcadores , Células de la Médula Ósea/metabolismo , Células de la Médula Ósea/patología , Femenino , Humanos , Inmunofenotipificación/métodos , Hibridación Fluorescente in Situ/métodos , Persona de Mediana Edad , Síndromes Mielodisplásicos/diagnósticoRESUMEN
A diagnosis of granulocytic sarcoma was made in a 2-year-old child based on the detection of myelomonocytic blasts in tissue obtained from a subcutaneous nodule with no evidence of concomitant disease in the bone marrow. The child responded to systemic chemotherapy and is in remission 3 years later. An identical clone with an in frame fusion of the MLL and AF10 genes was identified from both tissue and bone marrow samples. The generation of an in frame MLL-AF10 fusion requires complex intra- and interchromosomal exchanges between chromosomes 10 and 11. In this case, an intrachromosomal rearrangement of chromosome 5 was also observed. This case illustrates the presence of systemic disease in extramedullary leukaemia, its response to systemic rather than topical therapy and suggests that the events leading to chromosomal translocations in leukaemia may be part of a generalized intracellular event.
Asunto(s)
Células de la Médula Ósea , Cromosomas Humanos Par 5 , Reordenamiento Génico , Leucemia Mieloide/genética , Proto-Oncogenes , Enfermedad Aguda , Fusión Artificial Génica , Proteínas de Unión al ADN/genética , Electroforesis en Gel de Agar , Femenino , N-Metiltransferasa de Histona-Lisina , Humanos , Hibridación Fluorescente in Situ , Lactante , Cariotipificación , Proteína de la Leucemia Mieloide-Linfoide , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Transcripción/genéticaRESUMEN
The 5q- syndrome is a myelodysplastic syndrome with the 5q deletion ¿del(5q) as the sole karyotypic abnormality. We are using the expressed sequence tag (EST) resource as our primary approach to identifying novel candidate genes for the 5q- syndrome. Seventeen ESTs were identified from the Human Gene Map at the National Center for Biotechnology Information that had no significant homology to any known genes and were assigned between DNA markers D5S413 and D5S487, flanking the critical region of the 5q- syndrome at 5q31-q32. Eleven of the 17 cDNAs from which the ESTs were derived (65%) were shown to map to the critical region of the 5q- syndrome by gene dosage analysis and were then sublocalized by PCR screening to a YAC contig encompassing the critical region. Eight of the 11 cDNA clones, upon full sequencing, had no significant homology to any known genes. Each of the 8 cDNA clones was shown to be expressed in human bone marrow. The complete coding sequence was obtained for 2 of the novel genes, termed C5orf3 and C5orf4. The 2.6-kb transcript of C5orf3 encodes a putative 505-amino-acid protein and contains an ATP/GTP-binding site motif A (P loop), suggesting that this novel gene encodes an ATP- or a GTP-binding protein. The novel gene C5orf4 has a transcript of 3.1 kb, encoding a putative 144-amino-acid protein. We describe the cloning of 2 novel human genes and the sequencing, expression patterns, and mapping to the critical region of the 5q- syndrome of a further 6 novel cDNA clones. Genomic localization and expression patterns would suggest that the 8 novel cDNAs described in this report represent potential candidate genes for the 5q- syndrome.
Asunto(s)
Deleción Cromosómica , Mapeo Cromosómico , Cromosomas Humanos Par 5 , Perfilación de la Expresión Génica , Síndromes Mielodisplásicos/genética , Secuencia de Aminoácidos , Secuencia de Bases , Northern Blotting , Médula Ósea/metabolismo , Clonación Molecular , Mapeo Contig , ADN Complementario/química , ADN Complementario/genética , Dosificación de Gen , Expresión Génica , Genes , Humanos , Datos de Secuencia Molecular , ARN Mensajero/metabolismo , Análisis de Secuencia de ADN , Distribución TisularRESUMEN
Partial deletion of the long arm of chromosome 5, del(5q), is the cytogenetic hallmark of the 5q-syndrome, a distinct subtype of myelodysplastic syndrome-refractory anemia (MDS-RA). Deletions of 5q also occur in the full spectrum of other de novo and therapy-related MDS and acute myeloid leukemia (AML) types, most often in association with other chromosome abnormalities. However, the loss of genetic material from 5q is believed to be of primary importance in the pathogenesis of all del(5q) disorders. In the present study, we performed fluorescence in situ hybridization (FISH) studies using a chromosome 5-specific whole chromosome painting probe and a 5q subtelomeric probe to determine the incidence of cryptic translocations. We studied archival fixed chromosome suspensions from 36 patients with myeloid disorders (predominantly MDS and AML) and del(5q) as the sole abnormality. In 3 AML patients studied, this identified a translocation of 5q subtelomeric sequences from the del(5q) to the short arm of an apparently normal chromosome 11. FISH with chromosome 11-specific subtelomeric probes confirmed the presence of 11p on the shortened 5q. Further FISH mapping confirmed that the 5q and 11p translocation breakpoints were the same in all 3 cases, between the nucleophosmin (NPM1) and fms-related tyrosine kinase 4 (FLT4) genes on 5q35 and the Harvey ras-1-related gene complex (HRC) and the radixin pseudogene (RDPX1) on 11p15.5. Importantly, all 3 patients with the cryptic t(5;11) were children: a total of 3 of 4 AML children studied. Two were classified as AML-M2 and the third was classified as M4. All 3 responded poorly to treatment and had short survival times, ranging from 10 to 18 months. Although del(5q) is rare in childhood AML, this study indicates that, within this subgroup, the incidence of cryptic t(5;11) may be high. It is significant that none of the 24 MDS patients studied, including 11 confirmed as having 5q-syndrome, had the translocation. Therefore, this appears to be a new nonrandom chromosomal translocation, specifically associated with childhood AML with a differentiated blast cell phenotype and the presence of a del(5q).
Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 11/genética , Cromosomas Humanos Par 5/genética , Leucemia Mieloide Aguda/genética , Leucemia Mielomonocítica Aguda/genética , Translocación Genética , Adulto , Anemia Refractaria con Exceso de Blastos/genética , Anemia Refractaria con Exceso de Blastos/patología , Diferenciación Celular , Niño , Preescolar , Cromosomas Humanos Par 11/ultraestructura , Cromosomas Humanos Par 5/ultraestructura , Femenino , Humanos , Hibridación Fluorescente in Situ , Cariotipificación , Leucemia Mieloide Aguda/mortalidad , Leucemia Mieloide Aguda/patología , Leucemia Mielomonocítica Aguda/mortalidad , Leucemia Mielomonocítica Aguda/patología , Masculino , Síndromes Mielodisplásicos/genética , Síndromes Mielodisplásicos/patología , Nucleofosmina , Pronóstico , Estudios Retrospectivos , Análisis de SupervivenciaRESUMEN
Cytogenetic studies in Chinese hamster ovary (CHO) cells using aqueous and organic extracts of pan masalas, as well as genomic damage observed among pan masala consumers have conclusively shown genotoxic potential of pan masala-a dry complex mixture of areca nut, lime, catechu, cardamom, unspecified flavoring agent, etc., often containing tobacco in it. Tobacco and areca nut, major ingredients of pan masala, are closely associated with oral cancer. The most widely studied group of compounds in the field of chemoprevention is retinoids which includes natural vitamin A, beta-carotene and synthetic derivatives of vitamin A. In the present study, antigenotoxic effect of beta-carotene (BC) and retinoic acid (RA) on genotoxic potential of pan masala have been evaluated in CHO cells with the help of sister chromatid exchange (SCE) frequency and chromosome aberration (CA) frequency as cytogenetic markers. The pulse treatment with pan masala plain/pan masala-tobacco (PM/PMT) extract in combination with either BC or RA yielded lower frequencies of CA and SCE in CHO cells as compared to the cultures treated with aqueous extract fo pan masalas alone. This antigenotoxic effect of BC and RA was more pronounced when treatment was given continuously for a longer duration. Thus, these results indicated possibility of using BC and RA to decrease the risk of oral cancer among pan masala chewers.
Asunto(s)
Antimutagênicos/farmacología , Areca/efectos adversos , Mutágenos/efectos adversos , Plantas Medicinales , Plantas Tóxicas , Tabaco sin Humo/efectos adversos , Tretinoina/farmacología , beta Caroteno/farmacología , Animales , Células CHO , Aberraciones Cromosómicas , Cricetinae , Intercambio de Cromátides HermanasRESUMEN
The 5q- syndrome is a distinct type of myelodysplastic syndrome (MDS) characterised by refractory anaemia, morphological abnormalities of megakaryocytes, and del(5q) as the sole cytogenetic abnormality. In contrast to patients with therapy-related MDS with 5q deletions, 5q- syndrome patients have a favourable prognosis and a low rate of transformation to acute leukaemia. We have previously delineated a common deleted region of 5.6 Mb between the gene for fibroblast growth factor acidic (FGF1) and the subunit of interleukin 12 (IL12B) in two patients with 5q- syndrome and small deletions, del(5)(q31q33). The present study used fluorescence in situ hybridisation (FISH) analysis of these and a third 5q- syndrome patient with a small deletion, del(5)(q33q34), to refine further the critical deleted region. This resulted in the narrowing of the common deleted region within 5q31.3-5q33 to approximately 3 Mb, flanked by the adrenergic receptor beta 2 (ADRB2) and IL/2B genes. The common region of loss in these three 5q- syndrome patients includes the macrophage colony-stimulating factor-1 receptor (CSF1R), secreted protein, acidic, cysteine-rich (SPARC), and glutamate receptor (GR1A1) genes. This 5q- syndrome critical region is telomeric to and distinct from the other critical regions on 5q associated with MDS and acute myeloid leukaemia.
Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 5/genética , Síndromes Mielodisplásicos/genética , Adulto , Anciano , Mapeo Cromosómico , Femenino , Marcadores Genéticos , Humanos , Hibridación Fluorescente in Situ , Cariotipificación , Persona de Mediana EdadRESUMEN
The 5q- syndrome is a myelodysplastic syndrome with specific hematological features and a good prognosis. Using molecular mapping techniques, we have previously defined the critical region of gene loss of the 5q- chromosome in the 5q- syndrome as the approximately 5-Mb region at 5q31-q33 flanked by the genes for FGF1 and IL12B. This region is completely represented by a series of overlapping YACs, and we are currently generating a transcription map with the aim of identifying the tumor-suppressor gene associated with the development of the 5q- syndrome. In this study two techniques have been used: first, the screening of full-length cDNA libraries with radiolabeled YACs and second, the mapping of chromosome 5-specific expressed sequence tags (ESTs) to a YAC contig. A 1-Mb YAC contig encompassing the CSF1R gene has been used to screen a fetal brain cDNA library, and this has resulted in the identification of two genes comprising one known gene previously localized to the region (ADRB2) and one known gene previously unlocalized. Six of 135 chromosome 5-specific ESTs were localized by PCR screening to the YAC contig mapping to the critical region of the 5q- syndrome. IMAGE cDNA clones for each of the six ESTs have been obtained. These seven (excluding ADRB2) newly assigned cDNA clones were subjected to further analysis. The expression patterns of each of the cDNA clones have been established in a range of human tissues, including bone marrow. Six of seven cDNAs are expressed in human bone marrow. Six of seven cDNAs have no known homology to any deposited human sequences, and one (C29) is dihydropyrimidinase-related protein-3, a member of a novel gene family. Genomic localization and expression patterns would suggest that these newly assigned cDNAs represent potential candidate genes for the 5q- syndrome.
Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 5 , Síndromes Mielodisplásicos/genética , Mapeo Cromosómico , Cromosomas Artificiales de Levadura , ADN Complementario , Dosificación de Gen , Humanos , Lugares Marcados de SecuenciaRESUMEN
Mitomycin C (MMC)-induced lymphocytic sister chromatid exchange (SCE) frequency was studied in 40 oral cancer (OC) patients, 40 normal tobacco chewers (NC) and in 40 normal healthy individuals not consuming tobacco/areca nut in any form. Significantly higher MMC-induced SCE/cell values were observed among OC patients as compared to healthy non-chewer controls as well as NC. Although the mean SCE frequency for NC was comparable to that of healthy controls, three individuals showed an SCE rate higher than the highest observed among controls. The comparable frequency of the tobacco habit in these three individuals with that of the rest of the thirty-seven individuals indicated the possible involvement of factors other than tobacco consumption for the higher susceptibility to mutagens.
Asunto(s)
Linfocitos/efectos de los fármacos , Neoplasias de la Boca/inmunología , Mutágenos/farmacología , Plantas Tóxicas , Intercambio de Cromátides Hermanas/efectos de los fármacos , Tabaco sin Humo , Adulto , Anciano , Anciano de 80 o más Años , Areca , Células Cultivadas , Dieta Vegetariana , Resistencia a Medicamentos , Femenino , Humanos , Masculino , Masticación , Persona de Mediana Edad , Mitomicina/farmacología , Plantas Medicinales , TemplanzaRESUMEN
The chromosome-damaging effects of urine concentrates (UCs) from tobacco plus areca nut (T/AN) chewers (a highly popular habit and a major risk factor for oral cancer in India) were evaluated on Chinese hamster ovary (CHO) cells employing two cytogenetic end-points, namely chromosome aberration (CA) and sister chromatid exchange (SCE) frequencies. Urine creatinine levels were comparable between controls and T/AN chewers. CA and SCE frequencies in CHO cells were found to be elevated significantly (P < 0.001) following treatment with UCs prepared from T/AN chewers (UC-T/AN chewers) as well as with UCs of non-chewer controls (UC-control subjects). Moreover, elevation of these two parameters by UC-T/AN chewers was significantly higher in comparison to that of UC-controls. The results of the present study indicated that besides the oral cavity, which is a target organ for T/AN chewers, mutagens/carcinogens in tobacco and areca nut might be playing a causative role in cancer of the urinary bladder as well.
Asunto(s)
Areca/metabolismo , Células CHO/efectos de los fármacos , Aberraciones Cromosómicas , Plantas Medicinales , Plantas Tóxicas , Intercambio de Cromátides Hermanas , Tabaco sin Humo/metabolismo , Tabaco sin Humo/toxicidad , Orina/química , Animales , Biotransformación , Creatinina/orina , Cricetinae , Humanos , Valores de ReferenciaRESUMEN
The significance of the interaction between alcohol and tobacco in causing head and neck cancers is well documented. Our previous reports on in vitro studies using aqueous and organic extracts as well as cytogenetic studies among pan masala consumers have conclusively shown the genotoxic potential of pan masala--a dry mixture of the areca nut, lime, catechu, unspecified flavouring agents, etc., often containing tobacco in it and is widely consumed in India. Now in the present report, the clastogenic effect of ethanol and pan masala in different combinations was evaluated on Chinese hamster ovary cells utilizing chromosome aberration (CA) frequency as an endpoint. An ethanol concentration of up to 2.0% had no effect on CA/cell value. The low-dose continuous treatment and high-dose short-term pre-, post- and simultaneous treatment of ethanol and aqueous extract of pan masala with and without tobacco yielded dose-dependent elevations in CA frequency, compared to any of these two substances alone. Thus, these results provide evidence that alcohol consumption may potentially increase the risk of oral cancer among pan masala chewers.
Asunto(s)
Areca , Etanol/toxicidad , Mutágenos/toxicidad , Extractos Vegetales/toxicidad , Plantas Medicinales , Animales , Células CHO/efectos de los fármacos , Compuestos de Calcio/toxicidad , Catequina/toxicidad , Supervivencia Celular , Aberraciones Cromosómicas , Cricetinae , Sinergismo Farmacológico , Aromatizantes/toxicidad , Mitosis/efectos de los fármacos , Pruebas de Mutagenicidad , Óxidos/toxicidad , Plantas Tóxicas , Tabaco sin Humo/toxicidadRESUMEN
Cytogenetic markers such as chromosome aberration (CA), sister-chromatid exchange (SCE) and micronucleated cells (MNC) were used to assess the genotoxic potential of dimethyl sulphoxide (DMSO) extract of pan masala with and without tobacco (PM-T and PM). Using in vitro short-term assays, the extracts were tested in the presence or absence of metabolic activation. In cultures without metabolic activation the extracts were found to increase the frequency of all the three parameters tested significantly, however those with activation elicited a weak response, implying that pan masalas contain solvent (DMSO)-soluble direct-acting mutagen.
Asunto(s)
Areca , Compuestos de Calcio/toxicidad , Catequina/toxicidad , Mutágenos/toxicidad , Óxidos/toxicidad , Extractos Vegetales/toxicidad , Plantas Medicinales , Plantas Tóxicas , Especias/toxicidad , Tabaco sin Humo/toxicidad , Animales , Biotransformación , Células CHO , Aberraciones Cromosómicas , Cricetinae , Pruebas de Micronúcleos , Intercambio de Cromátides HermanasRESUMEN
Effects of aqueous extracts of a popular brand of pan masala with and without tobacco (PM-T and PM) were studied for short duration treatment employing an in vitro system. Metabolic activation with S9 mix was also included. Frequency of all the three cytogenetic endpoints viz., chromosome aberration (CA); sister chromatid exchange (SCE) and % micronucleated cells (% MNC) were found to be elevated significantly in a dose-dependent manner in cultures without metabolic activation. However, addition of S9 activation system resulted in suppression of chromosomal damage. Our findings indicate that pan masalas contain water soluble direct acting mutagens.