Navegando por Palavras-chave "citogenética"
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- ItemAcesso aberto (Open Access)Avaliação da frequência das alterações citogenéticas e de expressão gênica em LMA ao diagnóstico e, sequencialmente, na remissão(Universidade Federal de São Paulo (UNIFESP), 2016-10-18) Serehi, Daniele Canavezi [UNIFESP]; Chauffaille, Maria de Lourdes Lopes Ferrari [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Acute myeloid leukemias (AML) are genetic heterogeneous neoplastic diseases. Distinctive clinical features in each subtype requires attention to define the proper disease classification and prognostic factors. With the recent reports of the increasing number of mutations and alternative pathways that regulates gene expression in AML, it becomes a challenge to establish an investigative conduct covering the widest possible range of the disease alterations, especially when there are a few studies assessing the scope of gene expression and cytogenetics in patients with AML.Therefore, a better understanding of genetic aspects of the disease is essential to propose improvements. Objective: Evaluate the frequency of different cytogenetic changes and the expression of some genes in adult patients with AML and correlate them with the clinical characteristics at diagnosis, the hematologic remission and risk stratification. Methods: We performed G-band karyotype of bone marrow aspirate; FISH-panel AML/MDS or PCR for PML-RARA, when there was no result of the karyotype, gene expressions analysis of FLT3, NPM1, CEBPA, WT1, RUNX1, MLL, CKIT, NRAS and KRAS via real-time PCR and mutation analysis of FLT3, NPM1 and CKIT genes. Results: In 55 cases, 80% of the karyotype, FISH and PCR to PML-RARA results were obtained, with a frequency of 53% rearrangements detected. In 44 patients it was possible to assess gene expression and analysis of mutations, with a frequency of 52% abnormal gene expressions - 32% in more than one gene, and 20.4% of mutations, indicating that gene expression can be influenced by other pathways, besides the mutations, to produce the leukemic cell phenotype. Conclusion: This study demonstrates the range of genetic alterations, many ongoing and unrelated to mutations, that can be found in patients with AML and offers a different view on the investigative approach of these diseases, endorsing the necessity for a broad diagnosis to trace an accurate profile of each case and properly determine the risk stratification and prognosis.
- ItemAcesso aberto (Open Access)Citogenética e biologia molecular em leucemia linfocítica crônica(Associação Brasileira de Hematologia e Hemoterapia e Terapia Celular, 2005-12-01) Chauffaille, Maria de Lourdes Lopes Ferrari [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Fleury Centro de Medicina DiagnósticaThe analysis of chromosomal abnormalities in chronic lymphocytic leukemia is important at diagnosis, since it allows the identification of a malignant clone as well as helping in the differentiation of other lymphoproliferative disorders; at follow up, in order to permit the detection of additional abnormalities; in the therapeutic decision, since the presence of del(17p) means resistance to treatment; in treatment monitoring as it allows the detection of residual disease or the diagnosis of transformation (Richter s transformation). Cytogenetics offers prognostic information and a better understanding of the disease. The analysis can be made by conventional G banding karyotyping, which detects around one third of abnormal cases or by FISH, which increases the rate of abnormality detection to 82%. FISH together with other prognostic criteria (mutation status, ZAP-70, etc) has allowed a better prognostication. The most frequent abnormalities are: trisomy 12 (+12), with a median survival of 9 years; translocation or deletion of 13q (t/del(13q)) with favorable prognosis and median survival of 11 years; deletion or translocation of 11q22-23, with 6.6 years of median survival; deletion of short arm of chromosome 17, del(17p), with median survival of 2.5 years; and deletion of 6q, translocation of 14q, giving a total of around 60% of the total abnormalities. Considering the importance of cytogenetics and prognostic information, every chronic lymphocytic leukemia patient should undergo FISH and karyotype evaluations, at diagnosis and during the follow up.
- ItemAcesso aberto (Open Access)CLL: chromosomal abnormalities (FISH) and their relation with clinical stage, CD38 and ZAP-70(Associação Brasileira de Hematologia e Hemoterapia e Terapia Celular, 2006-03-01) Nascimento, Marilia C. [UNIFESP]; Yamamoto, Mihoko [UNIFESP]; Rodrigues, Maria Madalena [UNIFESP]; Franco, Luciana F. [UNIFESP]; Kimura, Elisa Y. S. [UNIFESP]; Vasconcelos, Yuri [UNIFESP]; Oliveira, José Salvador Rodrigues de [UNIFESP]; Figueiredo, Vera L. P. [UNIFESP]; Chauffaille, Maria de Lourdes Lopes Ferrari [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Chronic lymphocytic leukemia is the most prevalent type of leukemia in the West. It is characterized by an extremely variable clinical course. The aim of the study was to detect the most frequent chromosomal abnormalities in patients with CLL using FISH, and assess them regarding age, gender, clinical stage and CD38 and ZAP-70 expressions. We found 51.7% of the patients with chromosome abnormalities. The most frequent one was del 13q14 in 34.5% of cases. It was associated to other alterations in 17.2%. 17p13 deletions were found in 17.2% and trisomy 12 in 13.8% (in isolation in 6.9% and associated to del 13q14, in 6.9% of the cases). An 11q22 deletion was found in one case associated to a 13q14 deletion. To better evaluate the relationship between chromosome aberrations and other prognostic factors in CLL, two cytogenetics groups were considered: favorable (13q deletion in isolation and no alteration) and unfavorable outcomes (trisomy 12, 17p13 deletion, 11q22 deletion and two simultaneous alterations).The unfavorable alterations were more frequently seen among young individuals (<60y). There were more females (70%) than males in this group (p=0.04). In relation to the Binet's staging system, patients with unfavorable cytogenetic alterations, tended to be B and C stages, while in the favorable group prevailed patients in stage A. Additionally, patients with poor prognostic cytogenetics tended to express CD38 and ZAP-70 proteins.
- ItemSomente MetadadadosEstudo da mutação do gene npm1 e sua relação com a mutação do gene flt3 em pacientes adultos com leucemia mieloide aguda(Universidade Federal de São Paulo (UNIFESP), 2014-11-26) Kimura, Eliza Yuriko Sugano [UNIFESP]; Yamamoto, Mihoko Yamamoto [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Introduction: AML is an aggressive and highly heterogeneous hematologic malignancy, as well as the most prevalent acute leukemia in adults. NPM1 mutation is a largely observed molecular change with significant prognostic value, especially in the intermediate cytogenetic group. Objective: Evaluate the frequency of NPM1 mutation, its prognostic value through clinical and laboratorial factors comparison and its association to FLT3 mutation. Methods: 121 consecutive patients with de novo AML were analyzed. The median age was 55 years (57 men and 64 women aged between 17-88). Diagnostic methods included morphological analysis, flow cytometric immunophenotyping and conventional G banding cytogenetic analysis. NPM1 molecular study was performed by sequencing the exon 12 genomic DNA, previously purified and subjected to PCR. The chain termination method applied was dideoxynucleotides and the amplification was reverse primer based. The electropherograms were analyzed by ABI PRISM 377 DNA Sequencing Analysis version 3.3. The sequences were aligned to the standard sequence contained in the GenBank database (accession number NM_002520.5). Results: The distribution of patients according to FAB classification were: 12 M0, 23 M1, 37 M2, 20 M3, 12 M4, M5a 6, 7 M5b, 2 M6, 1 N / C and 1 basophil. The NPM1 mutation was detected in 19.8% of LMAs studied and in 27.3% of the cytogenetic intermediate risk group. TCTC duplication (mutation A) was the most frequent, accounting for 77.3%. The NPM1 mutation was associated with increased leukocytosis (p = 0.002) and a higher percentage of blast cells in BM (p = 0.016). It was more frequent in monocytic LMAs (p = 0.003) and was rare or absent in M3 and M0. The CD34 expression was inversely related to the presence of the mutation and the double negative CD34 / HLA-DR (p <0.001 and p <0.012, respectively). CD14 expression was associated with NPM1 mutation (p = 0.022). In cytogenetic intermediate risk group, all parameters kept association and lower CD117 expression was observed in AML NPM1-mut compared to NPM1wt (63.5 vs. 96.5; p = 0.048). Assessing the molecular favorable prognosis group (NPM1-mut / FLT3wt) and the adverse group (NPM1wt / FLT3-ITD), the lack of expression of CD34 and double-negative for CD34 and HLA DR (p <0.001 and p = 0.005, respectively) were both associated with the favorable group. Age, gender and WBC showed no relevance. Furthermore, 18.2% (6/33) presented the favorable genetic prognosis (NPM1-mut / FLT3wt) while 9.1% (3/33) the adverse prognosis (NPM1wt / FLT3-ITD). Conclusion: The co-evaluation of FLT3 and NPM1 mutations enabled reallocation of 27% of the cytogenetic intermediate risk group patients between favorable or adverse prognosis group.
- ItemSomente MetadadadosPadronização do teste de arranjos de polimorfismos de nucleotídeos únicos (SNPa) para a detecção de anormalidades genético-moleculares em leucemia mieloide aguda e síndromes mielodisplásicas(Universidade Federal de São Paulo (UNIFESP), 2014-09-26) Noronha, Thiago Rodrigo de [UNIFESP]; Chauffaille, Maria de Lourdes Lopes Ferrari Chauffaille [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Introduction: Single nucleotide polymorphism array (SNPa) is a type of DNA microarray which is used to detect polymorphisms within a population. SNP is a variation of a single nucleotide in a DNA sequence, and is the most frequent type of variation in the genome. Millions of SNPs have been identified and a map of SNPs can be used as an excellent genotypic marker for research. SNPa has been widely used in cancer genetics due to its great performance in providing information of copy number variation (CNV) and copy neutral loss of heterozygosity (CN-LOH). In Onco-hematology, AML/MDS provide an interesting model for investigation of new molecular changes by SNPa with implications for pathogeneses of diseases. This is evidenced by the lack of cytogenetic abnormalities in cases of AML/MDS and general lack of molecular assays that can be used to detect such abnormalities. Objectives: The objectives of this study were to standardize the SNPa method in AML and MDS, and to establish the similarities and differences between SNPa and karyotype. Materials and Methods: 25 patients diagnosed with AML (n=22) and MDS (n = 3) were studied. The G-banding karyotype according to usual method and SNPa (Cytoscan HD - Affymetrix) were performed using DNA extracted from mononuclear cells from bone marrow (BM) and from buccal cells (BC). Results: The mean age of the patients studied was 54 years old, and the median age, 55 years (range from 28 – 93). 12 (48%) were male and 13 (52%) female. 10 patients showed abnormal karyotype (40,0%), 11 normal (44,0%) and 4 had no mitosis (16,0%). Regarding the BM SNPa: 17 were abnormal (68.0%) and 8 were normal (32.0%). Comparing the karyotype with SNPa from the 25 cases, by karyotype was possible to detect a total of 17 alterations (deletions/loss: 8, trissomy/gain: 7 and translocation: 2) and by SNPa a total of 42 alterations (loss: 17, gain: 16 and CN-LOH: 9). Conclusion: It was possible to standardize SNPa in AML/MDS and compare it with the abnormalities detected by karyotype. SNPa increased the detection rate of abnormalities compared to the karyotype. It was possible to confirm that it is a reliable and sensitive instrument for detecting submicroscopic and CN-LOH changes. SNPa also offered a new set of abnormalities that deserve to be further investigated in future studies.