Efeitos da clonagem na inativação do cromossomo X e da regulação nutricional do metabolismo da metionina na qualidade ovocitária em bovinos

Pós-graduação em Medicina Veterinária - FMVZ

Epigenetic and expression analysis of TRAIL-R2 and BCL2: on the TRAIL to knowledge of apoptosis in ovarian tumors

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

No Relationship between the Amount of DNA Damage and the Level of hMLH1 and RASSF1A Gene Expression in Bladder Cancer Cells Treated with Cisplatin and Gemcitabine

Tumor response to antineoplastic drugs is not always predictable. This is also true for bladder carcinoma, a highly recurrent neoplasia. Currently, the combination of cisplatin and gemcitabine is well accepted as a standard protocol for treating bladder carcinoma. However, in some cases, this treatment protocol causes harmful side effects. Therefore, we investigated the roles of the genes TP53, RASSF1A (a tumor suppressor gene) and hMLH1 (a gene involved in the mismatch repair pathway) in cell susceptibility to cisplatin/gemcitabine treatment. Two bladder transitional carcinoma cell (TCC) lines, RT4 (wild-type TP53) and 5637 (mutated TP53), were used in this study. First, we evaluated whether the genotoxic potential of cisplatin/gemcitabine was dependent on TP53 status. Then, we evaluated whether the two antineoplastic drugs modulated RASSF1A and hMLH1 expression in the two cell lines. Increased DNA damage was observed in both cell lines after treatment with cisplatin or gemcitabine and with the two drugs simultaneously, as depicted by the comet assay. A lack of RASSF1A expression and hypermethylation of its promoter were observed before and after treatment in both cell lines. On the other hand, hMLH1 downregulation, unrelated to methylation status, was observed in RT4 cells after treatment with cisplatin or with cisplatin and gemcitabine simultaneously (wild-type TP53); in 5637 cells, hMLH1 was upregulated only after treatment with gemcitabine. In conclusion, the three treatment protocols were genotoxic, independent of TP53 status. However, cisplatin was the most effective, causing the highest level of DNA damage in both wild-type and mutated TP53 cells. Gemcitabine was the least genotoxic agent in both cell lines. Furthermore, no relationship was observed between the amount of DNA damage and the level of hMLH1 and RASSF1A expression. Therefore, other alternative pathways might be involved in cisplatin and gemcitabine genotoxicity in these two bladder cancer cell lines.

Associação genética entre o perfil de ácidos graxos e outras características da carcaça e carne de bovinos da raça Nelore

Pós-graduação em Genética e Melhoramento Animal - FCAV

Metilação de mercúrio em águas da região amazônica na presença e ausência de macrófitas: experimentos em microcosmos

Pós-graduação em Química - IQ

Estudo da distribuição e do potencial de metilação do mercúrio em solos e sedimentos de áreas a serem inundadas para aproveitamento hidrelétrico: Vinicius Marques Gomes. -

Pós-graduação em Química - IQ

Análise de metilação da região promotora do gene RASSF1 em linhagens celulares derivadas de carcinomas mamários

O câncer de mama é o tipo de neoplasia que mostra as maiores taxas de mortalidade entre as mulheres no Brasil, provavelmente pelo fato de que, na maioria dos casos, a doença é diagnosticada em estadios avançados, dificultando o sucesso do tratamento. Dessa forma, essa doença é considerada um problema crítico de saúde pública. O câncer é uma doença que se caracteriza por sucessivas alterações genéticas e epigenéticas que causam um crescimento e multiplicação celular desordenados. A hipermetilação da região promotora de genes específicos pode levar ao silenciamento gênico, um evento importante no processo da carcinogênese. Este estudo analisou o padrão de metilação da isoforma RASSF1A do gene RASSF1 em linhagens celulares derivadas de carcinoma mamário. Esse gene está mapeado na região cromossômica 3p21.3 e, segundo dados da literatura, atua como supressor tumoral. O principal objetivo desse estudo foi investigar a presença de hipermetilação na região promotora desse gene em linhagens celulares de carcinomas mamários. Para a realização dessa análise foi empregada a metodologia de MSP (Methylation-specific Polymerase Chain Reaction) convencional e de qMSP (Methylation-Specific Polymerase Chain Reaction quantitativa em tempo real). Todas as linhagens de carcinomas mamários analisadas no estudo (MCF7, MDA-MB-231, MDA-MB-453, MDA-MB-134 e SKBR3) apresentaram um padrão hipermetilado na região promotora do gene RASSF1 corroborando com dados da literatura que relacionam a inativação desse gene à hipermetilação do promotor. Estes dados, associados aos obtidos em uma análise paralela realizada em nosso laboratório que demonstrou a re-expressão do gene RASSF1 após o tratamento com o agente desmetilante 5 aza 2’desoxicitidina, confirmam a regulação epigenética desse gene supressor tumoral

Avaliação do padrão de metilação dos genes ESR1, ESR2 e PGR nas linhagens celulares derivadas do câncer de mama

Breast cancer has received an increasing attention because it is one of the most common cancer type and a leading cause of morbity and mortality among women worldwide. This disease has been considered as a heterogeneous condition, demonstrating a large spectrum of clinical and histopathological variability. In the last two decades, several studies have been conducted to identify new molecular markers of cancer cells, including the alterations of DNA methylation, which is the major epigenetic mechanism associated with the control of gene expression. The hypermethylation of promoter-associated CpG islands contributes to the loss of function of several cancer-related genes, including those encoding to the estrogen receptor (ESR) and progesterone receptor (PGR). This study aimed to determine the methylation patterns of CpG islands of the genes encoding the estrogen receptor α (ESR1 gene, promoters A and B), estrogen receptor β (ESR2 gene) and progesterone receptor (PGR gene, promoter A and B) in 15 cell lines derived from breast cancer. The DNA methylation analysis was based on the “Methylation Specific-Polymerase Chain Reaction” (MSP), which provides a qualitative assessment of the methylation status of a specific CpG island. The results revealed heterogeneous data: the promoter region of ESR1A showed complete methylation in one cell line (BT549) and only two cell lines showed partial methylation (MDA-MB-231 and MDA-MB-453), while the others lineages presented unmethylated alleles. The promoter region of isoform ESR1B was unmethylated in the cell lines BT549, SKBR3 and T47D; partial methylation were observed in the cell lines MDA-MB- 231, MCF-7 and ZR-75-30, while the others cell lines presented complete methylation. All lineages showed complete or partial methylation of the ESR2 gene. The methylation pattern of the promoter A of the PGR ...(Complete abstract click electronic access below)

Análise de metilação do gene FOXE1 em carcinoma de células escamosas em cães: padronização metodológica

It is believed that epigenetic mechanisms such as DNA methylation are important for the tumorigenesis and maintenance of the altered state of tumor cells. DNA methylation occurs by the addition of a methyl group to carbon 5 of cytosine, catalyzed by the enzyme DNA methyl-transferase, which can change the expression of a gene, including the tumor suppressor genes. In human squamous cell carcinoma, several features have shown the etiological role of genes in tumor development. Among them, FOXE1 gene (forkhead box E1 - thyroid transcription factor) is presented with an important role in susceptibility to disease. Similarly the FOXE1 methylation pattern could alter the expression of this gene in dogs and predisposed to tumor on. Therefore, this study aims to investigate in dogs, the validity of the strategy employed in humans to analyze the FOXE1 methylation status. DNA extraction from fresh frozen tumoral samples was performed by Wizard Genomic® DNA Purification Kit. The methylation status was determined by MSP-PCR (methylation-specific polymerase chain reaction), using 2.0 ng of DNA treated with sodium bisulphate. One hundred micrograms of bisulphite-modified DNA was amplified using primers specific for either methylated or unmethylated DNA (primers sequences are available at http://pathology2.jhu.edu/pancreas/primer.pdf). The analysis of fragments was loaded on to 7% polyacrylamide gels and silver nitrate staining. In this stage of technical approach, 60% were FOXE1 hypermethylated. In conclusion, it was observed that the standard technique for assessing the methylation pattern of gene FOXE1 in humans can be used for the same evaluation in dogs. The correlation of these molecular data with clinical and histopathological parameters may have diagnostic and prognostic value and still be used as a tumor marker for therapeutic decision and surgical approach

Investigação do perfil de metilação de genes candidatos a biomarcadores na endometriose

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Alterações epigenéticas do gene RASSF1 e investigação de modulação gene-específica por non-coding RNA em linhagens celulares derivadas de carcinomas mamários

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Alterações epigenéticas e do número de cópias do gene SFN em carcinomas mamários

Pós-graduação em Ciências Biológicas (Genética) - IBB

Análise de Alterações Cromossômicas, Mutações no Éxon 1 e do Padrão de Metilação da Região Promotora do Gene FOXO3 em Síndrome Mielodisplásica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Polissacarídeos da biomassa do basidiomiceto Rhizoctonia solani: extração, purificação e atividade biológica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

PHF21B as a candidate tumor suppressor gene in head and neck squamous cell carcinomas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)