DEBORA LEVY
Projetos de Pesquisa
Unidades Organizacionais
LIM/19 - Laboratório de Histocompatibilidade e Imunidade Celular, Hospital das Clínicas, Faculdade de Medicina
10 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 10
conferenceObject BONE MARROW MESENCHYMAL STEM CELLS DERIVED FROM HEALTHY DONORS BUT NOT THOSE DERIVED FROM ACUTE MYELOID LEUKEMIA PATIENTS ARE ABLE TO AFFECT PROLIFERATION AND DEATH OF LEUKEMIC CELL LINEAGES K562 AND K562 LUCENA(2021) FREITAS, F. A.; LEVY, D.; REICHERT, C. O.; LIMA-BARROS, P.; SAMPAIO-SILVA, J.; ROKITA-ROSA, L.; BYDLOWSKI, S. P.conferenceObject ONE STEP TECHNIQUETM IS EFFICIENT IN HARVESTING MESENCHYMAL STEM CELLS FROM HUMAN ADIPOSE TISSUE(2021) LEVY, D.; MELLO, L.; GIGLIO, P. N.; CENTURION, P.; VASQUEZ, M. W. M.; LOPES, L. A.; BYDLOWSKI, S. P.; DEMANGE, M. K.- LIMD2 Regulates Key Steps of Metastasis Cascade in Papillary Thyroid Cancer Cells via MAPK Crosstalk(2020) ARALDI, Rodrigo Pinheiro; MELO, Thatiana Correa de; LEVY, Debora; SOUZA, Dener Madeiro de; MAURICIO, Beatriz; COLOZZA-GAMA, Gabriel Avelar; BYDLOWSKI, Sergio Paulo; PENG, Hongzhuang; III, Frank J. Rauscher; CERUTTI, Janete MariaAlthough papillary thyroid carcinoma (PTC) has a good prognosis, 20-90% of patients show metastasis to regional lymph nodes and 10-15% of patients show metastasis to distant sites. Metastatic disease represents the main clinical challenge that impacts survival rate. We previously showed that LIMD2 was a novel metastasis-associated gene. In this study, to interrogate the role of LIMD2 in cancer invasion and metastasis, we used CRISPR-mediated knockout (KO) of LIMD2 in PTC cells (BCPAP and TPC1). Western blot and high-content screening (HCS) analysis confirmed functional KO of LIMD2. LIMD2 KO reduced in vitro invasion and migration. Ultrastructural analyses showed that cell polarity and mitochondria function and morphology were restored in LIMD2 KO cells. To unveil the signals supervising these phenotypic changes, we employed phospho-protein array. Several members of the MAPK superfamily showed robust reduction in phosphorylation. A Venn diagram displayed the overlap of kinases with reduced phosphorylation in both cell lines and showed that they were able to initiate or sustain the epithelial-mesenchymal transition (EMT) and DNA damage checkpoint. Flow cytometry and HCS validation analyses further corroborated the phospho-protein array data. Collectively, our findings show that LIMD2 enhances phosphorylation of kinases associated with EMT and invasion. Through cooperation with different kinases, it contributes to the increased genomic instability that ultimately promotes PTC progression.
- Identification of very small cancer stem cells expressing hallmarks of pluripotency in B16F10 melanoma cells and their reoccurrence in B16F10-derived clones(2020) CAMARA, Diana Aparecida Dias; SA JUNIOR, Paulo Luiz de; AZEVEDO, Ricardo Alexandre de; FIGUEIREDO, Carlos Rogerio; ARALDI, Rodrigo Pinheiro; LEVY, Debora; SOUZA, Dener Madeiro de; KERKIS, IrinaMelanoma is characterized by high heterogeneity and plasticity, most likely due to the presence of mutated melanocyte stem cells or immature progenitor cells in the skin that serves as precursors to melanoma. In the present study, for the first time, we identified rare cells in the murine melanoma B16F10, and human A2058 and SK-MEL-28 cell lines that express pluripotency markers, including Oct4, Nanog, Sox2 and a marker of melanoma cancer cells (ALDH1/2). These cells are very small with round morphology and they grow onto melanoma cells, thereby demonstrating feeder layer dependence similar to that of other pluripotent cells. These cells underwent self-renewal, symmetric and asymmetric division. We called these cells murine very small cancer stem cells (VSCSC). VSCSC were also found in B16F10-derived clones after 3-5 consecutive passages, where they occur as single cells or as small colonies, nevertheless, always using melanoma cells as feeders. These cells formed melanospheres enriched with Oct4-and ALDH1/2-positive cells. We also evaluated the possible effect of VSCSC that presented in the parental cell line (B16F10) and in clones based on their functional characteristics. We found that VCSCS present in the B16F10 cell line reappearing in their clones were required for continuous tumor growth and were responsible for melanoma cell heterogeneity and plasticity rather than directly affecting functional characteristics of melanoma cells. Our data, together with those of previous reports suggested the existence of melanoma-competent melanocyte stem cells, which corroborate the hypothesis of the existence of tumor-initiating cells and cancer stem cell hierarchies, at least in melanoma.
- 7-Ketocholesterol Promotes Oxiapoptophagy in Bone Marrow Mesenchymal Stem Cell from Patients with Acute Myeloid Leukemia(2019) PAZ, Jessica Liliane; LEVY, Debora; OLIVEIRA, Beatriz Araujo; MELO, Thatiana Correia de; FREITAS, Fabio Alessandro de; REICHERT, Cadiele Oliana; RODRIGUES, Alessandro; PEREIRA, Juliana; BYDLOWSKI, Sergio Paulo7-Ketocholesterol (7-KC) is a cholesterol oxidation product with several biological functions. 7-KC has the capacity to cause cell death depending on the concentration and specific cell type. Mesenchymal stem cells (MSCs) are multipotent cells with the ability to differentiate into various types of cells, such as osteoblasts and adipocytes, among others. MSCs contribute to the development of a suitable niche for hematopoietic stem cells, and are involved in the development of diseases, such as leukemia, to a yet unknown extent. Here, we describe the effect of 7-KC on the death of bone marrow MSCs from patients with acute myeloid leukemia (LMSCs). LMSCs were less susceptible to the death-promoting effect of 7-KC than other cell types. 7-KC exposure triggered the extrinsic pathway of apoptosis with an increase in activated caspase-8 and caspase-3 activity. Mechanisms other than caspase-dependent pathways were involved. 7-KC increased ROS generation by LMSCs, which was related to decreased cell viability. 7-KC also led to disruption of the cytoskeleton of LMSCs, increased the number of cells in S phase, and decreased the number of cells in the G1/S transition. Autophagosome accumulation was also observed. 7-KC downregulated the SHh protein in LMSCs but did not change the expression of SMO. In conclusion, oxiapoptophagy (OXIdative stress + APOPTOsis + autophagy) seems to be activated by 7-KC in LMSCs. More studies are needed to better understand the role of 7-KC in the death of LMSCs and the possible effects on the SHh pathway.
- Expression of CysLTR1 and 2 in Maturating Lymphocytes of Hyperplasic Tonsils Compared to Peripheral Cells in Children(2016) PAULUCCI, Bruno Peres; PEREIRA, Juliana; PICCIARELLI, Patricia; LEVY, Debora; FRANCESCO, Renata Cantisani diCysteinyl-leukotriene receptors 1 and 2 (CysLTR1 and 2) are related to allergic inflammatory responses. Recent studies demonstrated their role in lymphocyte division and maturation in the bone marrow. Few data are available about CysLTRs function in lymphocyte maturation in tonsils. The objectives of this study are to compare CysLTRs expression in peripheral blood lymphocytes with expression in maturating lymphocytes of hyperplasic tonsil and to check the influence of respiratory allergies in this process. Leukocytes of peripheral blood (PL) and hyperplasic tonsils of children were immunostained for CysLTR1, CysLTR2, CD3 (T cells), and CD19 (B cells) and read in flow cytometer. Lymphocyte of tonsils were divided in differentiating small cells (SC) and mitotic large cells (LC); percentage of B and T cells expressing CysLTRs was determined, and comparison was done using ANOVA and Tukey's tests. Data were analyzed as a whole and categorizing patients according the presence of allergies. Sixty children were enrolled in this study. There was a large expression of CysLTR1 and 2 in CD3+ LC, and such expression decreased progressively in SC and PL. In B cells, the highest expression of CysLTR1 and 2 was found in PL while SC showed the lowest and LC showed the intermediate expression. This pattern kept unchanged in groups of allergic and non-allergic individuals. CysLTRs seem to be involved in lymphocyte maturation that occurs in tonsils, without influence of allergies. New studies aiming the clinic treatment of tonsil hyperplasia must be targeted to the development of drugs capable of blocking both CysLTR1 and 2.
- Traditional and Advanced Cell Cultures in Hematopoietic Stem Cell Studies(2019) RIBEIRO-FILHO, Antonio Carlos; LEVY, Debora; RUIZ, Jorge Luis Maria; MANTOVANI, Marluce da Cunha; BYDLOWSKI, Sergio PauloHematopoiesis is the main function of bone marrow. Human hematopoietic stem and progenitor cells reside in the bone marrow microenvironment, making it a hotspot for the development of hematopoietic diseases. Numerous alterations that correspond to disease progression have been identified in the bone marrow stem cell niche. Complex interactions between the bone marrow microenvironment and hematopoietic stem cells determine the balance between the proliferation, differentiation and homeostasis of the stem cell compartment. Changes in this tightly regulated network can provoke malignant transformation. However, our understanding of human hematopoiesis and the associated niche biology remains limited due to accessibility to human material and the limits of in vitro culture models. Traditional culture systems for human hematopoietic studies lack microenvironment niches, spatial marrow gradients, and dense cellularity, rendering them incapable of effectively translating marrow physiology ex vivo. This review will discuss the importance of 2D and 3D culture as a physiologically relevant system for understanding normal and abnormal hematopoiesis.
- Impact of Oxysterols on Cell Death, Proliferation, and Differentiation Induction: Current Status(2021) FREITAS, Fabio Alessandro de; LEVY, Debora; ZARROUK, Amira; LIZARD, Gerard; BYDLOWSKI, Sergio PauloOxysterols are oxidized derivatives of cholesterol produced by enzymatic activity or non-enzymatic pathways (auto-oxidation). The oxidation processes lead to the synthesis of about 60 different oxysterols. Several oxysterols have physiological, pathophysiological, and pharmacological activities. The effects of oxysterols on cell death processes, especially apoptosis, autophagy, necrosis, and oxiapoptophagy, as well as their action on cell proliferation, are reviewed here. These effects, also observed in several cancer cell lines, could potentially be useful in cancer treatment. The effects of oxysterols on cell differentiation are also described. Among them, the properties of stimulating the osteogenic differentiation of mesenchymal stem cells while inhibiting adipogenic differentiation may be useful in regenerative medicine.
- Protocol for qRT-PCR analysis from formalin fixed paraffin embedded tissue sections from diffuse large b-cell lymphoma: Validation of the six-gene predictor score(2016) TEKIN, Nilgun; OMIDVAR, Nader; MORRIS, Tim Peter; CONGET, Paulette; BRUNA, Flavia; TIMAR, Botond; GAGYI, Eva; BASAK, Ranjan; NAIK, Omkar; AUEWARKUL, Chirayu; SRITANA, Narongrit; LEVY, Debora; CERCI, Juliano Julio; BYDLOWSKI, Sergio Paulo; PEREIRA, Juliana; DIMAMAY, Mark Pierre; NATIVIDAD, Filipinas; CHUNG, June-Key; BELDER, Nevin; KUZU, Isinsu; PAEZ, Diana; DONDI, Maurizio; CARR, Robert; OZDAG, Hilal; PADUA, Rose AnnAs a part of an international study on the molecular analysis of Diffuse Large B-cell Lymphoma (DLBCL), a robust protocol for gene expression analysis from RNA extraction to qRT-PCR using Formalin Fixed Paraffin Embedded tissues was developed. Here a study was conducted to define a strategy to validate the previously reported 6-gene (LMO2, BCL6, FN1, CCND2, SCYA3 and BCL2) model as predictor of prognosis in DLBCL. To avoid variation, all samples were tested in a single centre and single platform. This study comprised 8 countries (Brazil, Chile, Hungary, India, Philippines, S. Korea, Thailand and Turkey). Using the Kaplan-Meier and log rank test on patients (n=162) and two mortality risk groups (with those above and below the mean representing high and low risk groups) confirmed that the 6-gene predictor score correlates significantly with overall survival (OS, p< 0.01) but not with event free survival (EFS, p= 0.18). Adding the International Prognostic Index (IPI) shows that the 6-gene predictor score correlates significantly with high IPI scores for OS (p< 0.05), whereas those with low IPI scores show a trend not reaching significance (p= 0.08). This study defined an effective and economical qRT-PCR strategy and validated the 6-gene score as a predictor of OS in an international setting.
- Integrated molecular, biochemical, and physiological assessment unravels key extraction method mediated influences on rat neonatal cardiomyocytes(2018) JENSEN, Leonardo; NERI, Elida; BASSANEZE, Vinicius; OLIVEIRA, Nathalia C. De Almeida; DARIOLLI, Rafael; TURACA, Lauro T.; LEVY, Debora; VERONEZ, Douglas; FERRAZ, Mariana S. A.; ALENCAR, Adriano M.; BYDLOWSKI, Sergio P.; CESTARI, Idagene A.; KRIEGER, Jose EduardoNeonatal cardiomyocytes are instrumental for disease modeling, but the effects of different cell extraction methods on basic cell biological processes remain poorly understood. We assessed the influence of two popular methods to extract rat neonatal cardiomyocytes, Pre-plating (PP), and Percoll (PC) on cell structure, metabolism, and function. Cardiomyocytes obtained from PP showed higher gene expression for troponins, titin, and potassium and sodium channels compared to PC. Also, PP cells displayed higher levels of troponin I protein. Cells obtained from PC displayed higher lactate dehydrogenase activity and lactate production than PP cells, indicating higher anaerobic metabolism after 8 days of culture. In contrast, reactive oxygen species levels were higher in PP cells as indicated by ethidium and hydroxyethidium production. Consistent with these data, protein nitration was higher in PP cells, as well as nitrite accumulation in cell medium. Moreover, PP cells showed higher global intracellular calcium under basal and 1mM isoprenaline conditions. In a calcium-transient assessment under electrical stimulation (0.5Hz), PP cells displayed higher calcium amplitude than cardiomyocytes obtained from PC and using a traction force microscope technique we observed that PP cardiomyocytes showed the highest relaxation. Collectively, we demonstrated that extraction methods influence parameters related to cell structure, metabolism, and function. Overall, PP derived cells are more active and mature than PC cells, displaying higher contractile function and generating more reactive oxygen species. On the other hand, PC derived cells display higher anaerobic metabolism, despite comparable high yields from both protocols.