ESTELA MARIA NOVAK
Projetos de Pesquisa
Unidades Organizacionais
Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina
LIM/36 - Laboratório de Pediatria Clínica, Hospital das Clínicas, Faculdade de Medicina
LIM/31 - Laboratório de Genética e Hematologia Molecular, Hospital das Clínicas, Faculdade de Medicina
LIM/36 - Laboratório de Pediatria Clínica, Hospital das Clínicas, Faculdade de Medicina
LIM/31 - Laboratório de Genética e Hematologia Molecular, Hospital das Clínicas, Faculdade de Medicina
10 resultados
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- Synthesis, characterization and biological evaluation of Rutin-zinc(II) flavonoid -metal complex(2015) IKEDA, Norma Estefania Andrades; NOVAK, Estela Maria; MARIA, Durvanei Augusto; VELOSA, Adelia Segin; PEREIRA, Regina Mara SilvaSynthesis of compounds analogous to natural products from secondary metabolites, such as flavonoids, is a promising source of novel drugs. Rutin (quercetin-3-O-rutinoside) is a natural flavone, which has, in its chemical structure, different sites for coordination with transition metals and the complexation with these metals enhances its biological properties. Rutin-zinc(II), a flavonoid-metal complex, was synthesized and characterized by UV-VIS, FT-IR, elemental analysis and H-1 NMR. The antioxidant and antitumor activities, as well as the cytotoxicity and in vivo toxicity of this complex were evaluated and compared with the free rutin. Rutin-zinc(II) has not shown any cytotoxicity against normal cells (fibroblasts and HUVECs) or toxicity in BALB/c mice, but has shown antioxidant activity in vitro and cytotoxicity against leukemia (KG1, K562 and Jurkat), multiple myeloma (RPMI8226) and melanoma (B16F10 and SK-Mel-28) cell lines in vitro. In Ehrlich ascites carcinoma model, Rutin-zinc(II) modulated the mitochondrial membrane potential and the expression of genes related to cell cycle progression, angiogenesis and apoptosis.
- Differential expression of genes encoding proteins of the HGF/MET system in insulinomas(2015) MURAT, Cahue de Bernardis; ROSA, Paula Waki Lopes da; FORTES, Maria Angela Henriques Zanella; CORREA, Luciana; MACHADO, Marcel Cerqueira Cesar; NOVAK, Estela Maria; SIQUEIRA, Sheila Aparecida Coelho; PEREIRA, Maria Adelaide Albergaria; CORREA-GIANNELLA, Maria Lucia; GIANNELLA-NETO, Daniel; GIORGI, Ricardo RodriguesBackground: Insulinomas are the most common functional pancreatic neuroendocrine tumors, whereas histopathological features do not predict their biological behaviour. In an attempt to better understand the molecular processes involved in the tumorigenesis of islet beta cells, the present study evaluated the expression of genes belonging to the hepatocyte growth factor and its receptor (HGF/MET) system, namely, MET, HGF; HGFAC and ST14 (encode HGF activator and matriptase, respectively, two serine proteases that catalyze conversion of pro-HGF to active HGF); and SPINT1 and SPINT2 (encode serine peptidase inhibitors Kunitz type 1 and type 2, respectively, two inhibitors of HGF activator and of matriptase). Methods: Quantitative real-time reverse transcriptase polymerase chain reaction was employed to assess RNA expression of the target genes in 24 sporadic insulinomas: 15 grade 1 (G1), six grade 2 (G2) and three hepatic metastases. Somatic mutations of MET gene were searched by direct sequencing of exons 2, 10, 14, 16, 17 and 19. Results: Overexpression of MET was observed in the three hepatic metastases concomitantly with upregulation of the genes encoding HGF and matriptase and downregulation of SPINT1. A positive correlation was observed between MET RNA expression and Ki-67 proliferation index while a negative correlation was detected between SPINT1 expression and the mitotic index. No somatic mutations were found in MET gene. Conclusion: The final effect of the increased expression of HGF, its activator (matriptase) and its specific receptor (MET) together with a decreased expression of one potent inhibitor of matriptase (SPINT1) is probably a contribution to tumoral progression and metastatization in insulinomas.
- A model for preservation of thymocyte-depleted thymus(2023) DIAS, A. S.; DAMACENO-RODRIGUES, N. R.; GIMENEZ, T. M.; OLIVEIRA, P. M.; ZERBINI, M. C.; CARNEIRO-SAMPAIO, M.; FILHO, V. Odone; JATENE, M. B.; VASCONCELOS, D. M.; ROCHA, V.; NOVAK, E. M.DiGeorge syndrome is a disorder caused by a microdeletion on the long arm of chromosome 22. Approximately 1% of patients diagnosed with DiGeorge syndrome may have an absence of a functional thymus, which characterizes the complete form of the syndrome. These patients require urgent treatment to reconstitute T cell immunity. Thymus transplantation is a promising investigational procedure for reconstitution of thymic function in infants with congenital athymia. Here, we demonstrate a possible optimization of the preparation of thymus slices for transplantation through prior depletion of thymocytes and leukocyte cell lineages followed by cryopreservation with cryoprotective media (5% dextran FP 40, 5% Me2SO, and 5% FBS) while preserving tissue architecture. Thymus fragments were stored in liquid nitrogen at -196 & DEG;C for 30 days or one year. The tissue architecture of the fragments was preserved, including the distinction between medullary thymic epithelial cells (TECs), cortical TECs, and Hassall bodies. Moreover, depleted thymus fragments cryopreserved for one year were recolonized by intrathymic injections of 3 x 106 thymocytes per mL, demonstrating the capability of these fragments to support T cell development. Thus, this technique opens up the possibility of freezing and storing large volumes of thymus tissue for immediate transplantation into patients with DiGeorge syndrome or atypical (Omenn-like) phenotype.
- High-Resolution Magic-Angle-Spinning NMR in Revealing Hepatoblastoma Hallmarks(2022) TASIC, Ljubica; AVRAMOVIC, Natasa; JADRANIN, Milka; QUINTERO, Melissa; STANISIC, Danijela; MARTINS, Lucas G. G.; COSTA, Tassia Brena Barroso Carneiro; NOVAK, Estela; ODONE, Vicente; RIVAS, Maria; AGUIAR, Talita; CARRARO, Dirce Maria; CUNHA, Isabela Werneck da; COSTA, Cecilia Maria Lima da; MASCHIETTO, Mariana; KREPISCHI, AnaCancer is one of the leading causes of death in children and adolescents worldwide; among the types of liver cancer, hepatoblastoma (HBL) is the most common in childhood. Although it affects only two to three individuals in a million, it is mostly asymptomatic at diagnosis, so by the time it is detected it has already advanced. There are specific recommendations regarding HBL treatment, and ongoing studies to stratify the risks of HBL, understand the pathology, and predict prognostics and survival rates. Although magnetic resonance imaging spectroscopy is frequently used in diagnostics of HBL, high-resolution magic-angle-spinning (HR-MAS) NMR spectroscopy of HBL tissues is scarce. Using this technique, we studied the alterations among tissue metabolites of ex vivo samples from (a) HBL and non-cancer liver tissues (NCL), (b) HBL and adjacent non-tumor samples, and (c) two regions of the same HBL samples, one more centralized and the other at the edge of the tumor. It was possible to identify metabolites in HBL, then metabolites from the HBL center and the border samples, and link them to altered metabolisms in tumor tissues, highlighting their potential as biochemical markers. Metabolites closely related to liver metabolisms such as some phospholipids, triacylglycerides, fatty acids, glucose, and amino acids showed differences between the tissues.
- Gene expression profile suggesting immunological dysregulation in two Brazilian Bloom's syndrome cases(2020) MONTENEGRO, Marilia M.; QUAIO, Caio R.; PALMEIRA, Patricia; GASPARINI, Yanca; RANGEL-SANTOS, Andreia; DAMASCENO, Julian; NOVAK, Estela M.; GIMENEZ, Thamires M.; YAMAMOTO, Guilherme L.; RONJO, Rachel S.; NOVO-FILHO, Gil M.; CHEHIMI, Samar N.; ZANARDO, Evelin A.; DIAS, Alexandre T.; NASCIMENTO, Amom M.; COSTA, Thais V. M. M.; DUARTE, Alberto J. da S.; COUTINHO, Luiz L.; KIM, Chong A.; KULIKOWSKI, Leslie D.Background Bloom syndrome (BS) is a rare autosomal recessive chromosome instability disorder. The main clinical manifestations are growth deficiency, telangiectasic facial erythema, immunodeficiency, and increased risk to develop neoplasias at early age. Cytogenetic test for sister chromatid exchanges (SCEs) is used as a diagnostic marker for BS. In addition, most patients also present mutations in the & x202f;BLM & x202f;gene, related to defects in the DNA repair mechanism. However, the molecular mechanism behind the pathogenicity of BS is & x202f;still & x202f;not completely understood. Methods We describe two patients confirmed with BS by SCE and molecular analysis. Also, we performed the gene expression profile by the RNA-seq methodology in mRNA transcripts for differential gene expression analysis using as a biological condition for comparison BS versus health controls. Results We detected 216 differentially expressed genes related to immunological pathways such as positive regulation and activation of B cells, immune effector process and absence of difference of DNA repair genes expression. In addition; we also observed differentially expressed genes associated with apoptosis control, such as BCL2L1, CASP7, CDKN1A, E2F2, ITPR, CD274, TNFAIP6, TNFRSF25, TNFRSF13C, and TNFRSF17. Conclusion Our results suggest that the combination of altered expression of genes involved in signaling pathways of immune response and apoptosis control may contribute directly to the main characteristics observed in BS, such as recurrent infections, growth failure, and high risk of cancer. Transcriptome studies of other instability syndromes could allow a more accurate analysis of the relevant gene interactions associated with the destabilization of the genome. This is a first description of the profile of differential gene expression related to immunological aspects detected in patients with BS by RNA-seq.
- Antitumoural activity of Brazilian red propolis fraction enriched with xanthochymol and formononetin: An in vitro and in vivo study(2014) NOVAK, Estela Maria; SILVA, Martha Silveira e Costa; MARCUCCI, Maria Cristina; SAWAYA, Alexandra Christine Helena Frankland; LOPEZ, Begona Gimenez-Cassina; FORTES, Maria Angela Henriques Zanella; GIORGI, Ricardo Rodrigues; MARUMO, Kamila Tamie; RODRIGUES, Rosangela Felipe; MARIA, Durvanei AugustoIn this study, ultra-high performance liquid chromatography-mass spectrometry and tandem mass spectrometry of selected ions were used to characterise the ethanolic extract of a sample of Brazilian red propolis (EEBRP) and an active fraction (BRP-IV) containing xanthochymol and formononetin. The antiproliferative effect of BRP-IV was assayed using melanoma tumour xenografts in mice and HL-60, K562, RPMI8226, B16F10 cell lines. This fraction inhibited growth of tumour cell lines with IC50 values of 20.5 +/- 2.4 to 32.6 +/- 2.6 mu g/mL while EEBRP induced cytotoxic effect with IC50 values of 29.7 +/- 1.5 to 42.1 +/- 8.7 mu g/mL. BRP-IV also inhibited the proliferation of B16F10 cells by blocking cell cycle progression in the G2/M phase and inducing apoptosis. Administration of 10 mg/kg/day BRP-IV suppressed the growth of B16F0 tumour xenografts in C57BL/6 mice with less general toxicity than control groups. Taken together, these results indicate that BRP-IV can be considered a promising anticancer drug for the treatment of human cancers.
- HOXB7 mRNA is overexpressed in pancreatic ductal adenocarcinomas and its knockdown induces cell cycle arrest and apoptosis(2013) CHILE, Thais; FORTES, Maria Angela Henriques Zanella; CORREA-GIANNELLA, Maria Lucia Cardillo; BRENTANI, Helena Paula; MARIA, Durvanei Augusto; PUGA, Renato David; PAULA, Vanessa de Jesus R. de; KUBRUSLY, Marcia Saldanha; NOVAK, Estela Maria; BACCHELLA, Telesforo; GIORGI, Ricardo RodriguesBackground: Human homeobox genes encode nuclear proteins that act as transcription factors involved in the control of differentiation and proliferation. Currently, the role of these genes in development and tumor progression has been extensively studied. Recently, increased expression of HOXB7 homeobox gene (HOXB7) in pancreatic ductal adenocarcinomas (PDAC) was shown to correlate with an invasive phenotype, lymph node metastasis and worse survival outcomes, but no influence on cell proliferation or viability was detected. In the present study, the effects arising from the knockdown of HOXB7 in PDAC cell lines was investigated. Methods: Real time quantitative PCR (qRT-PCR) (Taqman) was employed to assess HOXB7 mRNA expression in 29 PDAC, 6 metastatic tissues, 24 peritumoral tissues and two PDAC cell lines. siRNA was used to knockdown HOXB7 mRNA in the cell lines and its consequences on apoptosis rate and cell proliferation were measured by flow cytometry and MTT assay respectively. Results: Overexpression of HOXB7 mRNA was observed in the tumoral tissues and in the cell lines MIA PaCa-2 and Capan-1. HOXB7 knockdown elicited (1) an increase in the expression of the pro-apoptotic proteins BAX and BAD in both cell lines; (2) a decrease in the expression of the anti-apoptotic protein BCL-2 and in cyclin D1 and an increase in the number of apoptotic cells in the MIA PaCa-2 cell line; (3) accumulation of cell in sub-G1 phase in both cell lines; (4) the modulation of several biological processes, especially in MIA PaCa-2, such as proteasomal ubiquit-independent catabolic process and cell cycle. Conclusion: The present study confirms the overexpression of HOXB7 mRNA expression in PDAC and demonstrates that decreasing its protein level by siRNA could significantly increase apoptosis and modulate several biological processes. HOXB7 might be a promising target for future therapies.
- BLM germline and somatic PKMYT1 and AHCY mutations: Genetic variations beyond MYCN and prognosis in neuroblastoma(2016) NOVAK, E. M.; HALLEY, N. S.; GIMENEZ, T. M.; RANGEL-SANTOS, A.; AZAMBUJA, A. M. P.; BRUMATTI, M.; PEREIRA, P. L.; VINCE, C. S. C.; GIORGI, R. R.; BENDITE, I.; CRISTOFANI, L. M.; ODONE-FILHO, V.Neuroblastoma (NB) is the most common extra cranial solid tumor of childhood and often lethal in childhood. Clinical and biologic characteristics that are independently prognostic of outcome in NB are currently used for risk stratification to optimally the therapy. It includes age at diagnosis, International Neuroblastoma Staging System tumor histopathology and MYCN amplification. However, even in patients with theoretically good prognosis, such as localized tumor and non amplified MYCN, either disease progress or recurrence may occur. Potential genetic determinants of this unfavorable behavior are not yet fully clarified. The presence of elevated expression of AHCY, PKMYT1, and BLM has accompanied poor prognosis MYCN-amplified neuroblastoma patients. Considering the potential implication of these genes on the clinical management of NB, we hypothesize that the identification-of genetic variations may have significant impact during development of the recurrent or progressive disease. Using targeted DNA sequencing, we analyzed the mutation profiles of the genes PKMYT1, AHCY, and BLM in tumor samples of five patients with MYCN amplified and 15 MYCN non-amplified NB. In our study, BLM germline variants were detected in two patients with MYCN-non-amplified neuroblastoma. Our data allow us to hypothesize that, regardless of MYCN status, these mutations partially abolish BLM protein activity by impairing its ATPase and helicase activities. BLM mutations are also clinically relevant because BLM plays an important role in DNA damage repair and the maintenance of genomic integrity. We also found a novel variant in our cohort, PKMYT1 mutation localized in the C-terminal domain with effect unknown on NB. We hypothesize that this variant may affect the catalytic activity of PKMYT1 in NB, specifically when CDK1 is complexed to cyclins. The prognostic value of this mutation must be further investigated. Another mutation identified was a nonsynonymous variant in AHCY. This variant may be related to the slow progression of the disease, even in more aggressive cases. It affects the maintenance of the catalytic capacity of AHCY, leading to the consequent functional effects observed in the NB patients studied. In conclusion, our hypothesis may provide that mutations in BLM, AHCY and PKMYT1 genes found in children with MYCN-amplified or MYCN-non amplified neuroblastomas, may be associated with the prognosis of the disease.
- LHX6 promoter hypermethylation in oncological pediatric patients conceived by IVF(2023) DANGONI, Gustavo Dib; TEIXEIRA, Anne Caroline Barbosa; VINCE, Carolina Sgarioni Camargo; NOVAK, Estela Maria; GIMENEZ, Thamiris Magalhaes; MASCHIETTO, Mariana; ODONE FILHO, Vicente; KREPISCHI, Ana Cristina VictorinoThe multifactorial etiology of pediatric cancer is poorly understood. Environmental factors occurring during embryogenesis can disrupt epigenetic signaling, resulting in several diseases after birth, including cancer. Associations between assisted reproductive technologies (ART), such as in vitro fertilization (IVF), and birth defects, imprinting disorders and other perinatal adverse events have been reported. IVF can result in methylation changes in the offspring, and a link with pediatric cancer has been suggested. In this study, we investigated the peripheral blood methylomes of 11 patients conceived by IVF who developed cancer in childhood. Methylation data of patients and paired sex/aged controls were obtained using the Infinium MethylationEPIC Kit (Illumina). We identified 25 differentially methylated regions (DMRs), 17 of them hypermethylated, and 8 hypomethylated in patients. The most significant DMR was a hypermethylated genomic segment located in the promoter region of LHX6, a transcription factor involved in the forebrain development and interneuron migration during embryogenesis. An additional control group was included to verify the LHX6 methylation status in children with similar cancers who were not conceived by ART. The higher LHX6 methylation levels in IVF patients compared to both control groups (healthy children and children conceived naturally who developed similar pediatric cancers), suggested that hypermethylation at the LHX6 promoter could be due to the IVF process and not secondary to the cancer itself. Further studies are required to evaluate this association and the potential role of LHX6 promoter hypermethylation for tumorigenesis.
- Unraveling the Genetic Architecture of Hepatoblastoma Risk: Birth Defects and Increased Burden of Germline Damaging Variants in Gastrointestinal/Renal Cancer Predisposition and DNA Repair Genes(2022) AGUIAR, Talita; TEIXEIRA, Anne; SCLIAR, Marilia O.; BARROS, Juliana Sobral de; LEMES, Renan B.; SOUZA, Silvia; TOLEZANO, Giovanna; SANTOS, Fernanda; TOJAL, Israel; CYPRIANO, Monica; TOLEDO, Silvia Regina Caminada de; VALADARES, Eugenia; PINTO, Raquel Borges; ARTIGALAS, Osvaldo Afonso Pinto; AGUIRRE NETO, Joaquim Caetano de; NOVAK, Estela; CRISTOFANI, Lilian Maria; SUGAYAMA, Sofia M. Miura; ODONE, Vicente; CUNHA, Isabela Werneck; COSTA, Cecilia Maria Lima da; ROSENBERG, Carla; KREPISCHI, AnaThe ultrarare hepatoblastoma (HB) is the most common pediatric liver cancer. HB risk is related to a few rare syndromes, and the molecular bases remain elusive for most cases. We investigated the burden of rare damaging germline variants in 30 Brazilian patients with HB and the presence of additional clinical signs. A high frequency of prematurity (20%) and birth defects (37%), especially craniofacial (17%, including craniosynostosis) and kidney (7%) anomalies, was observed. Putative pathogenic or likely pathogenic monoallelic germline variants mapped to 10 cancer predisposition genes (CPGs: APC, CHEK2, DROSHA, ERCC5, FAH, MSH2, MUTYH, RPS19, TGFBR2 and VHL) were detected in 33% of the patients, only 40% of them with a family history of cancer. These findings showed a predominance of CPGs with a known link to gastrointestinal/colorectal and renal cancer risk. A remarkable feature was an enrichment of rare damaging variants affecting different classes of DNA repair genes, particularly those known as Fanconi anemia genes. Moreover, several potentially deleterious variants mapped to genes impacting liver functions were disclosed. To our knowledge, this is the largest assessment of rare germline variants in HB patients to date, contributing to elucidate the genetic architecture of HB risk.