LIVIA ROSA FERNANDES
Projetos de Pesquisa
Unidades Organizacionais
LIM/31 - Laboratório de Genética e Hematologia Molecular, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
Agora exibindo 1 - 4 de 4
- 7-Ketocholesterol overcomes drug resistance in chronic myeloid leukemia cell lines beyond MDRI mechanism(2017) FERNANDES, Livia Rosa; STERN, Ana Carolina Bassi; CAVAGLIERI, Rita de Cassia; NOGUEIRA, Fabio Cesar Sousa; DOMONT, Gilberto; PALMISANO, Giuseppe; BYDLOWSKI, Sergio PauloChronic myeloid leukemia (CML) is a myeloproliferative disease with a characteristic BCR-ABL tyrosine kinase (TK) fusion protein. Despite the clinical efficacy accomplished by TKIs therapies, disease progression may affect patient response rate to these inhibitors due to a multitude of factors that could lead to development of a mechanism known as multidrug resistance (MDR). 7-Ketocholesterol (7KC) is an oxidized cholesterol derivative that has been extensively reported to cause cell death in a variety of cancer models. In this study, we showed the in vitro efficacy of 7KC against MDR leukemia cell line, Lucena. 7KC treatment induced reduction in cell viability, together with apoptosis-mediated cell death. Moreover, downregulation of MDR protein caused intracellular drug accumulation and 7KC co-incubation with either Daunorubicin or Vincristine reduced cell viability compared to the use of each drug alone. Additionally, quantitative label-free mass spectrometry-based protein quantification showed alteration of different molecular pathways involved in cell cycle arrest, induction of apoptosis and misfolded protein response. Conclusively, this study highlights the effect of 7KC as a sensitizing agent of multi drug resistance CML and elucidates its molecular mechanisms. Significance: CML patients treated with tyrosine kinase inhibitors (TKIs) have showed a 5-year estimated overall survival of 89%, with cumulative complete cytogenetic response of 87%. However, development of drug resistance is a common feature of the disease progression. This study aimed at showing the effect of 7KC as a cytotoxic and sensitizing agent of multidrug resistance CML cell lines. The cellular and molecular basis of this compound were elucidated using a comprehensive strategy based on quantitative proteomic and cell biology assays. We showed that 7KC induced cell death and overcomes drug resistance in CML through mechanisms that go beyond the classical MDR1 pathways.
- Outside-in, inside-out: Proteomic analysis of endothelial stress mediated by 7-ketocholesterol(2017) ROSA-FERNANDES, Livia; MASELLI, Luciana M. P.; MAEDA, Nair Y.; PALMISANO, Giuseppe; BYDLOWSKI, Sergio P.Oxysterols are cholesterol oxidation products formed through enzymatic or autoxidation mechanisms. 7-ketocholeterol (7KC) is one of most abundant oxysterols found in atherosclerotic lesions. Its role in atherosclerosis pathogenesis has been broadly studied in a variety of models. The arterial microenvironment is a multicellular dynamic compartment that, among other systemic factors, is continuously stimulated by 7KC. Endothelial cells have a key role on that environment, being in intimate contact with both the blood stream and the vessel wall, the site of disease origin. 7KC has been shown to promote endothelial cell death and/or dysfunction, depending on its concentration. However, its contribution to the cell microenvironment through cell stimulation has not received much attention. Here we applied mass spectrometry-based proteomics followed by bioinformatics workflow to analyze the effect of a non-toxic 7KC concentration on endothelial cell protein expression and secretion in vitro. Trypsin digests were prepared from the secretome of the endothelial cells and from the total cell pellet after 24 h exposure to 7KC. All samples were analyzed by high resolution and accurate mass nano-LC MS/MS. After database search and statistical analysis, differentially expressed proteins were selected for further studies. Our workflow identified 1805 secreted proteins and 2203 intracellular proteins, and of these, 48 and 53, respectively, were regulated. Regulated proteins upon 7KC exposure are involved in unfolded protein response, vascular homeostasis, and reduced control of angiogenesis. Moreover, blood coagulation was another main pathway regulated through Tissue Factor Pathway Inhibitor (TFPI), an antithrombotic agent associated with coronary disease that we found to be more than 2 times downregulated. Taken together, these data show differential endothelial protein regulation and secretion upon 7KC exposure for short time periods under non-toxic conditions. Herewith, these data support the role of 7KC in atherosclerosis pathophysiology and thus reinforce the deleterious effect of endothelial cells stress in the arterial microenvironment.
conferenceObject URINARY MMP-9 AS CANDIDATE FOR A NON-INVASIVE PROSTATE CANCER BIOMARKER REVEALED BY QUANTITATIVE PROTEOMICS ANALYSIS(2017) KAWAHARA, Rebeca; ORTEGA, Fabio; ROSA-FERNANDES, Livia; GUIMARAES, Vanessa; LEITE, Katia; NAHAS, Willian; SROUGI, Miguel; LARSEN, Martin; PALMISANO, Giuseppe- Interrelationship between ATP-binding cassette transporters and oxysterols(2013) RUIZ, Jorge L. M.; FERNANDES, Livia R.; LEVY, Debora; BYDLOWSKI, Sergio P.ATP-binding cassette (ABC) transporters constitute a ubiquitous superfamily of membrane proteins responsible for the translocation of several substances across membranes using the chemical energy provided by ATP hydrolysis. ABC transporters participate in many physiological and pathophysiological processes, including cholesterol and lipid transportation and multidrug resistance. Oxysterols are the products of cholesterol oxidation, formed by both enzymatic and non-enzymatic mechanisms. The role of oxysterols in cholesterol metabolism and several diseases has been widely investigated, but many questions remain to be answered. Several lines of evidence link ABC transporter functions with cholesterol and oxysterol metabolism. This review discusses ABC transporters, oxysterols, and how they interact with each other.