Um caso de possível predisposição genética à síndrome mielodisplástica

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Fractal Characteristics of May-Grünwald-Giemsa Stained Chromatin Are Independent Prognostic Factors for Survival in Multiple Myeloma

The use of computerized image analysis for the study of nuclear texture features has provided important prognostic information for several neoplasias. Recently fractal characteristics of the chromatin structure in routinely stained smears have shown to be independent prognostic factors in acute leukemia. In the present study we investigated the influence of the fractal dimension (FD) of chromatin on survival of patients with multiple myeloma.We analyzed 67 newly diagnosed patients from our Institution treated in the Brazilian Multiple Myeloma Study Group. Diagnostic work-up consisted of peripheral blood counts, bone marrow cytology, bone radiograms, serum biochemistry and cytogenetics. The International Staging System (ISS) was used. In every patient, at least 40 digital nuclear images from diagnostic May-Grünwald-Giemsa stained bone marrow smears were acquired and transformed into pseudo-3D images. FD was determined by the Minkowski-Bouligand method extended to three dimensions. Goodness-of-fit of FD was estimated by the R(2) values in the log-log plots. The influence of diagnostic features on overall survival was analyzed in Cox regressions. Patients that underwent autologous bone marrow transplantation were censored at the day of transplantation.Median age was 56 years. According to ISS, 14% of the patients were stage I, 39% were stage II and 47% were stage III. Additional features of a bad prognosis were observed in 46% of the cases. When stratifying for ISS, both FD and its goodness-of-fit were significant prognostic factors in univariate analyses. Patients with higher FD values or lower goodness-of-fit showed a worse outcome. In the multivariate Cox-regression, FD, R(2), and ISS stage entered the final model, which showed to be stable in a bootstrap resampling study.Fractal characteristics of the chromatin texture in routine cytological preparations revealed relevant prognostic information in patients with multiple myeloma

Identificação das deleções e mutações do gene p53 em pacientes com mieloma múltiplo

O mieloma múltiplo (MM) é uma doença neoplásica caracterizada pelo acúmulo de plasmócitos na medula óssea (MO) com conseqüente osteólise, comprometimento da hematopoese e da síntese das imunoglobulinas normais e com a produção de imunoglobulina monoclonal ou de seus fragmentos. A sobrevida observada para pacientes com a doença varia de alguns meses a dez anos ou mais, o que impõe a busca de fatores prognósticos para a identificação de grupos que devam receber tratamento mais agressivo para o controle da doença. As anormalidades do cariótipo foram descritas, em geral, como fatores com valor prognóstico desfavorável. Por outro lado, não se encontram suficientemente estabelecidos os valores prognósticos das anormalidades numéricas do cromossomo 17 e das deleções e mutações do gene p53 em pacientes com MM. Frente ao exposto, estes constituíram os objetivos deste estudo. Para cumprir tais objetivos, foram avaliados 60 pacientes com MM no período de março de 1999 a dezembro de 2000. A avaliação das anormalidades numéricas do cromossomo 17 foi realizada por meio da análise citogenética convencional e do método de hibridização in situ com fluorescência (FISH), enquanto que a avaliação das deleções do gene foi realizada por meio do método FISH. As mutações do gene p53 foram investigadas por meio da reação em cadeia da polimerase, do polimorfismo de conformação em hélice simples e de seqüenciamento. Não foram identificadas mutações do gene p53 em qualquer dos pacientes incluídos no estudo. Em contraste, as deleções do gene, predominantemente monoalélicas, foram identificadas em 15,7% deles. Observamos ainda, que os pacientes com a deleção do gene p53 apresentaram menor probabilidade de sobrevida do que aqueles sem a deleção do gene (P= 0,0006). A mediana dos tempos de sobrevida global de pacientes do primeiro grupo foi menor do que a observada em pacientes do segundo grupo (7,5 e 17,0 meses, respectivamente; P= 0,05). Frente a estes resultados, pudemos concluir que a deleção do gene p53 constituiu um fator preditivo de menor sobrevida, em nossos casosMultiple myeloma (MM) is a neoplastic disease characterized by the accumulation of plasma cells in the bone marrow (BM) with consequent osteolysis, comprimising hematopoiesis and the synthesis of normal immunoglobins and the production of monoclonal immunoglobin or its fragments. The survival observed for patients with the disease varies from a few months to ten years or more, which makes the search for prognostic factors for the identification of groups which require more aggressive treatment for the control of the disease. Abnormalities of the karyotype have been described, in general, as factors with desfavorable prognostic value. On the other hand, the prognostic values of the numerical abnormalities of chromosome 17, and of the deletions and mutations of the p53 gene have not been sufficiently established as prognostic values in patients with MM. Thus, these were the objectives of this study. To view these objectives, 60 patients with MM were evaluated in the period of March, 1999 to December, 2000. The evaluation of the numerical abnormalities of chromossome 17 was performed by cytogenetic analysis and by the fluorescence in situ hybridization method (FISH), whilst the evaluation of p53 deletions was performed by FISH. The evaluation of p53 gene mutations was carried out using polymerase chain reaction, single strand conformation polymorphism and the sequencing. No mutations in the p53 gene were detected in any of the patients enroled in the study. In contrast, deletions of the gene, predominantly monoallelic, were identified in 15.7% of them. Furthermore, we observed that patients with p53 deletions demonstrated a lower probability of survival than those without gene deletion (P= 0.0006). The median survival time of the patients of the first group was lower than that observed in the second group of patients (7.5 and 17.0 months, respectively; P= 0.05). From these results, we may conclude that deletion of the p53 gene constituted a predictive factor of shorter survival, in our case

Detection of 13q deletion in multiple myeloma using immunomagnetically selected plasma cells Detecção de deleção 13q no mieloma múltiplo utilizando plasmócitos selecionados imunomagneticamente

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Polymorphisms of VEGF, GSTM1 and GSTT1 genes in multiple myeloma risk

sem informação30210510

Helicobacter pylori infection modulates the expression of miRNAs associated with DNA mismatch repair pathway

Genetic and epigenetic inactivation of DNA mismatch repair (MMR) genes might lead to modifications in cancer-related gene expression and cancer development. Recently, it has been shown that the infection by Helicobacter pylori, the major causative agent of gastric cancer, induces DNA damage and inhibits MMR DNA repair. Also, it has been reported that microRNAs (miRs) have an important role in regulating genomic stability and MMR DNA repair. Thus, the aim of this study was to identify miRs regulating MMR pathway in H. pylori-associated gastric carcinogenesis. To address this question, a gastric epithelial cell line and AGS cancer gastric cells were infected with several H. pylori strains. MMR gene expression and miRs correlating with H. pylori strain infection were evaluated. The results showed that H. pylori infection significantly down-regulated the expression of all selected MMR genes. Also, H. pylori infection modulated the expression of several miRs (including miR-150-5p, miR-155-5p, and miR-3163), after 4, 8, and 12 h of infection. Computational prediction of candidate miRs and their predicted MMR targeting sites were obtained from TargetScan, mirDB, and MetaCore. The generated data indicated that the selected miRs (miR-150-5p, miR-155-5p, and miR-3163) could possibly target and modulate MMR genes (POLD3, MSH2, and MSH3, respectively). The target validation was performed using mimics and luciferase gene reporter assays. Briefly, this study shows that H. pylori impairs MMR DNA repair pathway and identifies miRs that regulate MMR gene expression in gastric cancer.56413721379CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP300975/2014-72014/11862-