Navegando por Palavras-chave "leucemia mieloide aguda"

Agora exibindo 1 - 3 de 3
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Avaliação da expressão do gene twist1 no microambiente hipóxico da leucemia mieloide aguda
    (Universidade Federal de São Paulo (UNIFESP), 2015-11-25) Malafaia, Emilia Carolina Oliveira Brandao [UNIFESP]; Kerbauy, Daniella Marcia Bahia [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    TWIST1, a basic helix-loop-helix (bHLH) transcription factor, plays a critical role in mesodermal development and organogenesis. Overexpressed TWIST1 has been thoroughly related to epithelial-mesenchymal transition (EMT) in solid tumors and has been described as an emerging poor prognostic factor in hematological neoplasms. Many questions remain to be addressed concerning to the role of TWIST1 in acute myeloid leukemia (AML). The understanding of TWIST1 in leukemia cells and its interaction with microenvironment can offer new insights in regards to physiopathology and therapeutic targets for patients with AML. Objectives: to evaluate the role of stroma contact and hypoxia in TWIST1 expression in myeloid cell lines. 2) To evaluate the functional impact of overexpressing TWIST1 on KG1a and PL21 cells. 3) To evaluate TWIST1 expression in primary cells of AML patients. Methods: In order to mimic bone marrow microenvironment, myeloid cells were co-cultured with mesenchymal HS5 cell line and PO2 1% was established with Smart -Trak ? 2 (Sierra Instruments, Inc.) equipment. Quantitative mRNA was determined using TaqMan ? Universal Master Mix (Applied Biosystems, Foster City, CA) and 3-step standard cycling conditions with sequence-specific primer TWIST1 normalized to the expression of ?-actin. KG1a and PL21 cells were transduced with lentivirus vector carrying e-GFP ("enhanced green fluorescence protein") for stable expression of TWIST1. Transduced cells were sorted by FITC fluorochrome and then verified through western blot analysis with TWIST1 antibody. For quantification of apoptosis, cells were labeled with PE-conjugated antibody using annexin V?phycoerythrin and propidium iodide (BD Biosciences, USA). DAPI (4',6- diamidino-2-phenylindole dihydrochloride) was used to stain DNA and determine cell cycle information. Apoptosis and cell cycle were analyzed by FACS -Becton Dickinson Canto II (BD Biosciences). Statistical analysis was assessed with unpaired t test and Fisher?s exact test. Results: Hypoxia induced TWIST1 mRNA expression in OCIAML3, PL21, KG1a and ML1 cell lines (fold-increased 46.3, 29.8, 12.9 and 2.3 respectively). Cells expressing endogenous TWIST1 protein (OCIAML3 and ML1)! 88!showed resistance to apoptosis in a hypoxic microenvironment (normoxia versus hypoxia: OCI/AML3, 22.6 % vs 11.7% and ML1, 29.8% vs. 7.5%) in contrast, cells not expressing endogenous TWIST1 protein (KG1a and PL21) went to apoptosis in the same conditions. Thus, overexpressing TWIST1 in KG1a and PL21 induced apoptosis protection in hypoxia (KG1a unmodified vs. modified: 17.6 ± 6.3 vs. 2.8 ± 6.3, p=0.04; PL21 unmodified vs. modified: 26.9 ± 10.9 vs. 3.2 ± 0.6, p=0.04). We found increased TWIST1 mRNA levels in bone marrow samples of 18 AML patients (3,329 ± 0,64) compared with 6 healthy controls (1,25 ± 0,62) (p= 0.03). Patients in the highest tertile of TWIST1 expression did not show differences in prognostic and complete remission after treatment compared with patients in low and middle tertile. Conclusion: Our data suggest TWIST1 gene expression protects acute myeloid leukemia cells from apoptosis in a hypoxic microenvironment. Moreover, our results showed increased expression of TWIST1 in AML patients. Thus, TWIST1 is a potential gene involved in leukemogenesis and should be further explored to understand disease biology and potential therapeutic targets.
  • Imagem de Miniatura
    Item
    Acesso 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.
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Transplante de células-tronco hematopoéticas e leucemia mieloide aguda: diretrizes brasileiras
    (Associação Brasileira de Hematologia e Hemoterapia e Terapia Celular, 2010-05-01) Silla, Lucia Mariano R.; Dulley, Frederico; Saboya, Rosaura; Paton, Eduardo; Kerbauy, Fábio Rodrigues [UNIFESP]; Arantes, Adriano de Moraes [UNIFESP]; Hamerschlak, Nelson; Hospital de Clínicas de Porto Alegre Serviço de Hematologia e Transplante de Medula Óssea; Universidade de São Paulo (USP); Hospital de Câncer de Barret Hemonúcleo; Universidade Federal de São Paulo (UNIFESP); Associação de Combate ao Câncer em Goiás Hospital Araújo Jorge Serviço de Transplante de Medula Óssea; Hospital Israelita Albert Einstein Programa de Hematologia e Transplante de Medula Óssea
    The objective of this work was to define guidelines for the indication of hematopoietic stem cells transplantation (HSCT) in the treatment of acute myeloid leukemia (AML) in Brazil. The role of HSCT in the treatment of AML was discussed by the authors and presented to the Brazilian Society of Bone Marrow Transplantation in a meeting to formulate and ratify the Brazilian Guidelines on HSCT. This consensus was based on a review of international publications and on the Brazilian experience in HSCT for the treatment of AML. The optimal treatment for AML in first complete remission (1CR) has not been defined yet. There is consensus on the indication of allogeneic HSCT with myeloablative conditioning for patients who present high risk cytogenetic changes. Allogeneic HSCT is not indicated for low cytogenetic risk 1RC patients and, apparently, allogeneic and autologous HSCT and consolidation chemotherapy are similar for intermediate risk patients.