Navegando por Palavras-chave "Leukemic stem cells"

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    Beta carbolinas: estudo dos mecanismos de morte, proliferação e diferenciação em leucemias e células-tronco leucêmicas
    (Universidade Federal de São Paulo (UNIFESP), 2018-10-25) Torquato, Heron Fernandes Vieira [UNIFESP]; Gamero, Edgar Julian Paredes [UNIFESP]; http://lattes.cnpq.br/9562213378846769; http://lattes.cnpq.br/7439686090439905; Universidade Federal de São Paulo (UNIFESP)
    Acute myeloid leukemia ( AML) is a type of cancer that occurs from the clonal expansion of myeloid pr ecursors. Over the past few years, a hypothesis used to explain the leukemia origin has been the presence of a rare population inside of the tumor, which represents a refractory reservoir to therapy, named leukemic stem cell (LSC). For this reason, the elimination of this population is considered an important treatment method nowadays. Among all natural products that have provided new molecules with different clinical applications, we highlight the betacarbolinic alkaloids, in particular, the canthinone and its derived, which have demonstrated diverse pharmacological activities s uch as antibacterial, antifungal, antimalarial, antiulcerogenic and cytotoxic. Thus, the aim of this project was to investigate the antitumor effects of betacarbolinic alkaloids in leukemias and in the LSC population. Therefore, the effects of betacarboline alkaloids on cell death, proliferation and differentiation were investigated. It was observed that the effect on cell death occurred by apoptosis ( dissipation of mitochondrial potential, permeabilization of lysosomes, production of reactive oxygen species [ROS], and activation of caspases) and by Necroptosis ( use of pharmacological inhibitors of necroptosis, Nec1 and necrosulfonamide, as well as their association with caspase inhibitors). In addition, a cytostatic effect with cell cycle ar rest in the G2/M phase associated by activation of DNA damage sensor proteins and the decrease of clonogenic capability was observed. Induction of cell differentiation was also observed by expression increased of myeloid differentiation markers ( CD15, C D11b, C D14, P U.1 and MPO). The differentiation also affected LSC population with expression increase of PU.1 factor, and proliferation increase, but the reduction of clonogenic potential. Part of the effects on differentiation and proliferation was blocked by the p38 inhibitor, SB203580. The results show important actions of this metabolites class, highlighting the effects of MTXc as privileged structures for the construction of new antileukemic drugs
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    Canthin-6-one induces cell death, cell cycle arrest and differentiation in human myeloid leukemia cells
    (Elsevier Science Bv, 2017) Vieira Torquato, Heron F. [UNIFESP]; Ribeiro-Filho, Antonio C.; Buri, Marcus V. [UNIFESP]; Araujo Junior, Roberto T. [UNIFESP]; Pimenta, Renata [UNIFESP]; de Oliveira, Jose Salvador R. [UNIFESP]; Filho, Valdir C.; Macho, Antonio; Paredes-Gamero, Edgar J. [UNIFESP]; de Oliveira Martins, Domingos T.
    Background: Canthin-6-one is a natural product isolated from various plant genera and from fungi with potential antitumor activity. In the present study, we evaluate the antitumor effects of canthin-6-one in human myeloid leukemia lineages. Methods: Kasumi-1 lineage was used as a model for acute myeloid leukemia. Cells were treated with canthin-6one and cell death, cell cycle and differentiation were evaluated in both total cells (Lin(+)) and leukemia stem cell population (CD34(+) CD38(-)Lin(-/low) Results: Among the human lineages tested, Kasumi-1 was the most sensitive to canthin-6-one. Canthin-6-one induced cell death with apoptotic (caspase activation, decrease of mitochondrial potential) and necrotic (lysosomal permeabilization, double labeling of annexin V/propidium iodide) characteristics. Moreover, canthin-6-one induced cell cycle arrest at Go/Gi (7 mu M) and G2 (45 mu m) evidenced by DNA content, BrdU incorporation and cyclin Bl/histone 3 quantification. Canthin-6-one also promoted differentiation of Kasumi-1, evidenced by an increase in the expression of myeloid markers (CD11 b and CD15) and the transcription factor PU.1. Furthermore, a reduction of the leukemic stem cell population and clonogenic capability of stem cells were observed. Conclusions: These results show that canthin-6-one can affect Kasumi-1 cells by promoting cell death, cell cycle arrest and cell differentiation depending on concentration used. General significance: Canthin-6-one presents an interesting cytotoxic activity against leukemic cells and represents a promising scaffold for the development of molecules for anti-leukemic applications, especially by its anti-leukemic stem cell activity. (C) 2017 Elsevier B.V. All rights reserved.