Navegando por Assunto "Tumores em animais"

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Acesso aberto (Open Access)
Caracterização do padrão de expressão e metilação do gene P21CDKN1A/CIP1 em tumores mamários caninos
(Universidade Federal do Pará, 2018-04-20) SOUSA, Raissa Melo de; BORGES, Bárbara do Nascimento; http://lattes.cnpq.br/0676220027193876
The most of canine mammary tumors are malignant and associated with the animal death. One of the factors involved in this pathogenesis is the change in the expression level of the gene P21, which in turn encodes a protein that can inhibit tumor initiation and tumor progression. The methylation profile of gene can affect the cellular level of p21 and lead gene silencing or overexpression. Whereas the functional importance of the P21 gene, this study aimed to evalu-ate the methylation profile and expression in mammary tumors of dogs, in order to identify molecular markers of early diagnosis, survival and prognosis. Therefore, 83 tumor and non-tumor tissue samples were collected from dogs, undergoing surgery at the Veterinary Hospital "Mário Dias Teixeira”, in Belém -Pará. the DNA and RNA from each sample were submitted to extraction using a commercial kit. For the methylation analyzes, the obtained DNA was sub-mitted to the modification process, with a subsequent technique of Bisulfite Sequencing PCR, using region-specific primers and subsequent visualization in 2% agarose gel. The sequencing results were analyzed in BiQ Analyzer software in order to evaluate the methylation pattern. For gene expression analysis, the target gene mRNA was quantified using the real-time PCR technique using the GAPDH and HPRT1 genes as constitutive controls. Statistical data was performed using the Fisher Exact, Odds Ratio and Mann-Whitney tests in the GraphPad Prism program, considering the significant results when p ≤0.05, with a 95% confidence inter-val. In order to evaluate the methylation profile, the CpG islands of the P21 gene were characterized. The island 1 is located in an intron with 34 CGs, while an island 2 was identified in the exon, with 22 CGs. Both amplified generating a fragment of ~ 300bp. At island 1 no methylation was detected, whereas island 2 was methylated, but the island methylation profile was not different between the tumor, non-tumor and control samples. With these results was impossible compare the methylation values with clinical and expression data, suggesting that these regions are not altered. The expression levels of the tumor samples were low when compared to the non-tumor samples and control, with p (0.0001), show that the role of p21 in these tumors may be altered but not statistically significant when correlated with clinical histopathological data of patients. However, a reduced expression in the survival of animals> 1 year of age was observed, and a high expression in animals with survival <1 year of age, suggesting the influence of p21 as a marker of prognosis. More detailed studies of the P21 gene are still needed to see if these changes could be used as molecular markers, and thus aid on the prognosis and detection of cancer in the species.
Acesso aberto (Open Access)
Perfil de expressão e de metilação de genes dos complexos polycomb 1 e 2 em tumores mamários caninos
(Universidade Federal do Pará, 2017-02-17) LUNA, Francisco Canindé Ferreira de; BORGES, Bárbara do Nascimento; http://lattes.cnpq.br/0676220027193876
The Polycomb complex (PcG) consists of multiprotein factors that mediate the repression of various genes in the body. PcG proteins are divided into two distinct complexes, PRC1 and PRC2, with PRC1 having E3 ligase activity, catalyzing the mono-ubiquitination of histone H2A at lysine residues at position 119 (H2AK119ub), while PRC2 has methyltransferase activity, mediating mono, di, and trimethylation on histone H3 at lysine residues at position 27 (H3K27me2 / 3). It is known that PRC1 is subdivided into non-canonical and canonical complexes, the latter being composed of CBX proteins (CBX2, CBX4, CBX6, CBX7 or CBX8). Already PRC2, it comprises three central proteins: SUZ12, EED and EZH1 or EZH2, which is the methyltransferase protein responsible for conferring the main enzymatic activity to the PRC2 complex. It is known that deregulation of PcG proteins may alter developmental pathways, causing a disordered increase in cell proliferation, inhibition of apoptosis, and increase of tumor cells. Among the tumors with altered expression of PcG are mammary tumors. In canines, this type of tumor is the most frequent neoplasm in bitches. Thus, the objective of this study was to evaluate the methylation and expression pattern of the CBX2 and CBX7 (PRC1), and EED, EZH2 and SUZ12 (PRC2) genes in breast tumors in dogs from the state of Pará. Samples of neoplastic and non-neoplastic tissue from 40 animals collected at the Veterinary Hospital of the Federal Rural University of Amazônia. For the analysis of the methylation pattern, the samples were converted by sodium bisulfite and submitted to the Bissulfite sequence PCR technique to detect possible methylated areas. For analysis of RNA expression, cDNA conversion and subsequent quantification of transcripts were performed using Taqman probe detection. Fluorescence emission was captured with the aid of the ABI PRISM 7500 Sequence Detection System. Statistical analyzes were performed using the Kruskal-Wallis test and the Mann Whitnae test to evaluate the associations of methylation patterns with expression levels, and those with tumor progression and other clinicopathological characteristics. The results were considered significant when p <0, 05.