RESUMO
Defective DNA mismatch repair and nonfunctional mechanisms controlling the proper progression of the cell cycle have been proposed as being responsible for the genomic instability and accumulation of karyotypic alterations in endometrial cancer (EC). To assess whether numerical chromosomal anomalies (aneuploidy) and microsatellite instability (MSI) might be representative of distinctive tumour behaviour, paraffin-embedded tissue samples from 86 patients with sporadic EC were evaluated by both fluorescence in situ hybridisation (FISH) and microsatellite analysis, using free nuclei and genomic DNAs (respectively). Approximately one-third of the tumours analysed (24/74; 32%) exhibited MSI, whereas 38/86 (44%) of the EC samples displayed aneuploidy. The majority of the unstable cases (15/24; 63%) were from advanced-stage patients. Conversely, 23 (61%) out of the 38 tumours with aneuploidy were from early-stage patients. No apparent correlation was found between MSI and aneuploidy, whereas the immunohistochemical (IHC) analysis revealed that inactivation of the MLH1 mismatch repair gene may be involved in the majority of the MSI+ sporadic ECs. No genetic or cytogenetic alteration analysed here seems to add any significant predictive value to the stage of disease.
Assuntos
Aneuploidia , Neoplasias do Endométrio/genética , Repetições de Microssatélites/genética , Proteínas Adaptadoras de Transdução de Sinal , Adulto , Idoso , Pareamento Incorreto de Bases/genética , Proteínas de Transporte , Cromossomos Humanos Par 1/genética , Cromossomos Humanos Par 10/genética , Feminino , Humanos , Hibridização in Situ Fluorescente , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Proteínas de Neoplasias/genética , Proteínas Nucleares , TrissomiaRESUMO
Retrospective analysis of chromosomal changes in endometrial carcinoma was performed by fluorescence in situ hybridization on free nuclei isolated from formalin-fixed paraffin-embedded tissue. We examined 23 archival samples for numerical aberrations of chromosomes 1 and 10 with the use of specific DNA probes for the pericentromeric and centromeric regions of these two chromosomes. Numerical aberrations of chromosomes 1 and 10 were detected in 39% of the case analyzed, and the frequency of trisomy 10 tended to increase as the histological grade worsened. Our findings confirm the association of cytogenetic anomalies involving chromosomes 1 and 10 with endometrial carcinoma, as reported by other studies, and suggest that changes in centromere 10 copy number may correlate with the degree of tumor differentiation.
Assuntos
Aneuploidia , Carcinoma Adenoescamoso/genética , Carcinoma Endometrioide/genética , Cromossomos Humanos Par 10/genética , Cromossomos Humanos Par 1/genética , Neoplasias do Endométrio/genética , Adulto , Idoso , Feminino , Marcadores Genéticos , Humanos , Hibridização in Situ Fluorescente , Pessoa de Meia-Idade , Inclusão em Parafina , Estudos RetrospectivosRESUMO
The distal long arm of chromosome 10 harbors genes of biomedical interest such as MXI1, a putative tumor suppressor gene, and those encoding the adrenergic receptors alpha2A (ADRA2A) and beta1 (ADRB1). As part of a physical and genetic study of this genomic region, we constructed a 1.5-Mb YAC contig mapping to 10q25 that contains MXI1 and ADRA2A as well as a number of STSs. Rare cutting restriction site analysis of overlapping YACs allowed fine mapping of these genes and markers along the contig and revealed the presence of four CpG islands. MXI1 and ADRA2A appear to be about 600 kb apart, whereas ADRB1 is separated from ADRA2A by a distance larger than previously reported.
Assuntos
Proteínas de Ligação a DNA/genética , Receptores Adrenérgicos alfa 2/genética , Fatores de Transcrição/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Mapeamento Cromossômico , Cromossomos Artificiais de Levedura/genética , Cromossomos Humanos Par 10/genética , Ilhas de CpG , Genes Supressores de Tumor , Marcadores Genéticos , Humanos , Hibridização in Situ Fluorescente , Mapeamento por Restrição , Sitios de Sequências Rotuladas , Proteínas Supressoras de TumorRESUMO
Specific chromosomal aberrations might indicate the position of genes responsible for a particular disease. Neuroblastoma is characterized by frequent deletions and/or rearrangements of the subtelomeric 1p region which, accordingly, is believed to host one or more oncosuppressor gene(s) directly or indirectly involved in the development of this and other tumors. Identification of these genes could be facilitated if cell lines with well characterized interstitial deletions or reciprocal translocations could be available for application of positional cloning strategies. In the present report we present additional and novel molecular data on three well established neuroblastoma cell lines (NLF, NMB and NGP). In one of these we have identified two sites that might be good candidates for hosting oncosuppressor genes; one of these is flanked by the D1S47 and ENO1 loci while the other is distal to the A12M2 locus.
Assuntos
Clonagem Molecular/métodos , Neuroblastoma , Translocação Genética , Humanos , Hibridização in Situ Fluorescente , Células Tumorais Cultivadas/citologia , Células Tumorais Cultivadas/fisiologiaRESUMO
Cytogenetic and molecular studies suggest that chromosome 1p might contain oncosuppressor genes involved in the pathogenesis of neuroblastoma and other adult tumors. The isolation of these genes by the 'positional cloning' approach will be facilitated by the characterization of cell lines with well defined chromosomal aberrations. In the present report we provide molecular data on the NGP neuroblastoma cell line which contains a reciprocal t(1;15) translocation. Two regions, possibly hosting oncosuppressor genes, have been identified: one is distal to the ENO1 locus, the other one is comprised between PND and A12M2 and corresponds to that of a constitutional t(1;17) translocation described in a neuroblastoma patient. Genetic data also suggest that the NGP cell line, despite the presence of two chromosomes 1, might be hemizygous for the subtelomeric 1p region.
Assuntos
Cromossomos Humanos Par 15 , Cromossomos Humanos Par 1 , Família Multigênica , Neuroblastoma/genética , Translocação Genética , Adulto , Sequência de Bases , Cromossomos Artificiais de Levedura/genética , DNA de Neoplasias/genética , Rearranjo Gênico , Heterozigoto , Homozigoto , Humanos , Hibridização in Situ Fluorescente , Dados de Sequência Molecular , Sequências Repetitivas de Ácido Nucleico , Células Tumorais CultivadasRESUMO
The CYP2C gene cluster on chromosome 10q24 encodes the P450IIC enzymes, members of the cytochrome P450 monooxygenase superfamily. The P450-IIC enzymes are required for the metabolism of a number of foreign compounds, including the drugs mephenytoin and tolbutamide, and are also thought to be involved in the metabolism of endogenous steroid hormones. Several different CYP2C cDNA clones have been isolated; however, the exact number of genes and the genomic arrangement of the CYP2C cluster have remained unknown. Using a combination of STS and restriction mapping to characterize YAC clones, we have constructed a 2.4-Mb physical map that incorporates the CYP2C gene cluster. The cluster spans approximately 500 kb on proximal 10q24 and comprises four genes arranged in the order CYP2C8-CYP2C9-CYP2C19-CYP2C18. The map also includes an adjacent gene, the serum retinol binding protein gene (RBP4). The incorporation of Généthon CA repeat genetic markers suggests the orientation of the loci to be Cen-RBP4-CYP2C18-CYP2C19-CYP2C9-CYP2C8-Tel .
Assuntos
Hidrocarboneto de Aril Hidroxilases , Mapeamento Cromossômico , Cromossomos Humanos Par 10 , Sistema Enzimático do Citocromo P-450/genética , Esteroide 16-alfa-Hidroxilase , Esteroide Hidroxilases/genética , Sequência de Bases , Citocromo P-450 CYP2C8 , Citocromo P-450 CYP2C9 , Genes , Humanos , Dados de Sequência Molecular , Família Multigênica , Proteínas de Ligação ao Retinol/genética , Sitios de Sequências RotuladasRESUMO
A reciprocal t(1;15)(p36.1-36.3;q25-26) has been identified in an established neuroblastoma cell line (NGP) that earlier studies had shown to carry, among others, a rearrangement at the 1p subtelomeric region. Though it has not been possible to establish whether this translocation was constitutional, it is of interest to note that one of the breakpoints is located within the well-known 1p consensus site of tumor-associated chromosomal rearrangements where, as a result of the reciprocal translocation, the FES oncogene has been transferred from autosome 15. It is to be expected that the molecular cloning of the 1p and 15q translocation breakpoints may yield crucial data for understanding the association between specific chromosomal rearrangements and malignant tumor progression.
Assuntos
Cromossomos Humanos Par 15 , Cromossomos Humanos Par 1 , Sequência Consenso , Neuroblastoma/genética , Translocação Genética , Sequência de Bases , Mapeamento Cromossômico , Rearranjo Gênico , Marcadores Genéticos , Humanos , Hibridização in Situ Fluorescente , Dados de Sequência Molecular , Proto-Oncogenes , Células Tumorais CultivadasRESUMO
The protozoan flagellate Trichomonas vaginalis is responsible for human trichomoniasis, one of the most widespread sexually transmitted diseases in the world. Several methods are currently used for laboratory diagnosis, including direct microscopic observation, cell culture, immunological techniques, and more recently, DNA probing and gene amplification. This report describes an in situ hybridization technique with specific DNA probes labeled with either biotin, rhodamine, or fluorescein for detection of T. vaginalis with fluorescence microscopy. Repetitive DNA sequences were evident in the nuclei of the protozoa as intensively fluorescent regions, giving a spotted pattern. No cross-reactivity between the probes and the DNAs of mammalian cells, yeasts, or bacteria was noted. This technique is potentially useful for the diagnosis of human trichomoniasis in clinical samples.
Assuntos
DNA de Protozoário/genética , Hibridização in Situ Fluorescente/métodos , Trichomonas vaginalis/genética , Trichomonas vaginalis/isolamento & purificação , Animais , Sondas de DNA/genética , Estudos de Avaliação como Assunto , Feminino , Humanos , Mapeamento por Restrição , Vaginite por Trichomonas/diagnóstico , Vaginite por Trichomonas/microbiologia , Vagina/microbiologiaRESUMO
A cDNA clone coding for a human brain protein (HuD), which is highly homologous to the Drosophila neuronal determination protein Elav and elicits antibody formation in a high proportion of patients with paraneoplastic encephalomyelitis, was used to isolate a lambda phage recombinant clone, including a large fragment of the relevant human genomic region. The fragment proved to be an efficient probe for the precise subregional mapping of the gene by molecular in situ hybridization onto extended human prometaphase chromosomes. Analysis of banded metaphases with clear hybridization signals pointed unequivocally to the localization of the HuD gene to human chromosome band 1p34.
Assuntos
Cromossomos Humanos Par 1 , Proteínas do Tecido Nervoso/genética , Proteínas de Ligação a RNA/genética , Mapeamento Cromossômico , Sondas de DNA , Proteínas ELAV , Proteína Semelhante a ELAV 4 , Humanos , Hibridização in Situ FluorescenteRESUMO
Previous reports from our group suggested the preferential integration of the viral construct Ad5/SV40 at the short arm subtelomeric region of human chromosome 1. The present study narrows the region of viral integration to site 1p36.1 in a close cytogenetic overlap with the U1 snRNA gene cluster (RNU1) within a distance necessarily smaller than 400 kb as suggested by the size of the YAC in which the two markers were found to coexist. This finding supports the hypothesis that the chromosomal site in question may have a constitutional propensity to genetic recombination.
Assuntos
Adenovírus Humanos/genética , Cromossomos Humanos Par 1 , RNA Nuclear Pequeno/genética , Vírus 40 dos Símios/genética , Integração Viral , Mapeamento Cromossômico , Cromossomos Artificiais de Levedura , Genes , Humanos , Hibridização in Situ Fluorescente , Mapeamento por RestriçãoRESUMO
The structural gene for beta-galactoside-binding protein (Lgals-1), a cell growth regulatory molecule and cystostatic factor, is assigned to the E-region of mouse chromosome 15 and to the region q12-q13.1 of human chromosome 22. The evolutionary conservation of these two regions has been previously suggested from comparative mapping of several loci. These include the murine SIS oncogene (Pdgfb) and its human homolog, the platelet-derived growth factor-beta polypeptide, PDGFB. The findings presented here extend the genetic homology of the two regions.
Assuntos
Cromossomos Humanos Par 22 , Galactosídeos , Hemaglutininas/genética , Animais , Evolução Biológica , Mapeamento Cromossômico , Galectinas , Humanos , Hibridização in Situ Fluorescente , Camundongos , Fator de Crescimento Derivado de Plaquetas/genética , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-sisRESUMO
Trichomoniasis is one of the most widespread sexually transmitted diseases in the world. Diagnosis can be achieved by several methods, such as direct microscopic observation of vaginal discharge, cell culture, and immunological techniques. A 2.3-kb Trichomonas vaginalis DNA fragment present in strains from diverse geographic areas was cloned and used as a probe to detect T. vaginalis DNA in vaginal discharge by a dot blot hybridization technique. This probe was specific for T. vaginalis DNA. It recognized strains from two regions in Italy (Sardinia, Piemonte) and from Mozambique (Africa). In addition, our probe did not cross-react with bacterial (Escherichia coli, Enterococcus spp., group B streptococci, Gardnerella vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, and Lactobacillus spp.), viral (herpes simplex virus type 2), fungal (Candida albicans), protozoan (Entamoeba histolytica, Giardia lamblia, Plasmodium falciparum, Leishmania major, and Leishmania infantum), or human nucleic acids. The probe reacted with Pentatrichomonas hominis and Trichomonas foetus. The limit signal recognized by our probe corresponded to the DNA of 200 T. vaginalis isolates. The 2.3-kb probe was used in a clinical analysis of 98 samples. Of these, 20 samples were found to be positive both with the probe and by cell culture, and only 14 of these were positive by a standard wet mount method.