Análise do perfil de metilação e expressão do gene COX-2 em Sapajus apella como modelo experimenta para adenocarcinoma gástrico.

Ministério da Educação, Universidade Federal Rural da Amazônia, Fundação de Amparo a Pesquisa do Estado do Pará, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior e Conselho Nacional de Desenvolvimento Científico e Tecnológico.O adenocarcinoma gástrico continua a ser um fardo mundial como uma das principais causas de morte relacionada ao câncer. Existem duas formas de adenocarcinoma gástrico: a do tipo difuso e a do intestinal, sendo esta última caracterizada através de uma série de passos seqüenciais. Uma das enzimas mais alteradas durante esta progressão é a COX-2 que está presente em tumores e lesões pré-neoplásicas, sendo que vários estudos sugeriram que esta pode ser um fator importante na carcinogênese gástrica. Com o objetivo de estudar o padrão de metilação e de expressão de COX-2 durante os estágios de desenvolvimento do adenocarcinoma gástrico do tipo intestinal, foram utilizados seis animais da espécie Sapajus apella, induzidos à carcinogênese gástrica pelo uso de N-metil-N-nitrosurea (MNU), um potente agente mutagênico pertence à classe das nitrosamidas. A seqüência da região promotora do gene COX-2 de S. apella foi obtida usando iniciadores desenhados a partir das seqüências de Homo sapiens e Saimiri boliviensis, e utilizada para a identificação de sítios de ligação de fatores de transcrição e de elementos cis-regulatórios. A análise de metilação foi realizada pela técnica de PCR Metilação Específica (MSP) e a expressão analisada por Imunohistoquímica (IHQ). Foram obtidas 20 amostras, sendo que dos seis animais induzidos, apenas um desenvolveu tumor, enquanto os demais vieram a óbito ainda com lesões pré-neoplásicas. Foi obtido um fragmento de 675 pb do promotor de COX-2 de S. apella, e este apresentou uma similaridade de 99,2% e 68,2% com H. sapiens e S. boliviensis, respectivamente, sugerindo que S. apella pode ser considerado um modelo mais adequado que Saimiri para o estudo da carcinogênese comparada. Foram identificados diversos sítios de ligação para fatores de transcrição (CdxA, GATA-1 e GATA-2), bem como elementos cis-regulatórios, (P53RE, NF-Y e STAT), idênticos aos descritos para humanos. A análise de MSP revelou que todas as amostras analisadas (tecido normal, lesões pré-neoplásicas e tecido tumoral) apresentaram-se metiladas para o gene estudado. Já o teste de IHQ revelou que amostras normais foram as únicas que não apresentaram a expressão do gene, sugerindo que a região analisada em S. apella, não representa uma região chave na expressão de COX-2, fazendo-se necessários estudos mais aprofundados acerca da regulação transcricional desse gene.Gastric câncer (GC) remains one of the main causes of death by câncer in the world. There are two hystological types of GC: Diffuse and Intestinal, and the latter is characterized by the presence of pre-neoplastic lesions. One of the most altered enzymes during the Intestinal GC pathway is COX-2, considered an important marker of this type of lesion. This work aims to study the methylation and expression pattern of COX-2 during the Intestinal GC pathway in six animais of Sapajus apella, induced by N-methyl-N-Nitrosurea (MNU). The promoter sequence of S. apella COX-2 gene was obtained using primers designed from conserved regions of Homo sapiens and Saimiri boliviensis, and used for the Identification of transcription factors and cis-regulatory elements binding sites. Methylation pattern was assessed using Methylation Specific PCR (MSP) technique and the expression was analyzed by Immunohistochemistry (IHQ). A total of 20 samples were obtained, and from the six initially induced animais, only one developed gastric tumor. A fragment of 675 pb from the promoter region of S. apella COX-2 was obtained and this sequence was 99.2% and 68.2% similar with H. sapiens and S. boliviensis, suggesting that S. apella may be considered a more appropriate animal model than Saimiri for the comparative oncology study. Similar to humans, several binding sites for transcription factors (CdxA, GATA-1 and GATA-2), and cis-regulatory elements (P53RE, NF-Y and STAT), were identified in S. apella sequence. MSP revealed that ali studied samples (normal, pre-neoplastic and tumoral) were methylated. On the other hand, IHQ results pinpointed to a positive expression of COX-2 in ali pre-neoplastic and tumoral samples, suggesting that the analyzed fragment may not represent a core region in the COX-2 regulation in GC of S. apella. Our results suggest the needed of more studies about the transcriptional regulation of this gene in GC

Mitochondrial DNA Alterations in Glioblastoma (GBM)

Glioblastoma (GBM) is an extremely aggressive tumor originating from neural stem cells of the central nervous system, which has high histopathological and genomic diversity. Mitochondria are cellular organelles associated with the regulation of cellular metabolism, redox signaling, energy generation, regulation of cell proliferation, and apoptosis. Accumulation of mutations in mitochondrial DNA (mtDNA) leads to mitochondrial dysfunction that plays an important role in GBM pathogenesis, favoring abnormal energy and reactive oxygen species production and resistance to apoptosis and to chemotherapeutic agents. The present review summarizes the known mitochondrial DNA alterations related to GBM, their cellular and metabolic consequences, and their association with diagnosis, prognosis, and treatment

COX-2 gene expression and methylation profile in Sapajus apella as an experimental model for gastric adenocarcinoma

<div><p>Abstract Gastric cancer (GC) remains one of the main causes of cancer-related death worldwide. There are two distinct histological types of GC: diffuse and intestinal. The latter is characterized by the presence of pre-neoplastic lesions. One of the most frequently altered enzymes in intestinal GC is COX-2, an important lesion marker. This work aimed to study COX-2 methylation and expression in N-methyl-N-Nitrosurea (MNU)-induced intestinal GC in six Sapajus apella animals. The partial promoter sequence of S. apella COX-2 gene was obtained and used to identify transcription factors and cis-regulatory element binding sites. The COX-2 methylation pattern was assessed using Methylation-Specific PCR (MSP), and expression was analyzed by immunohistochemistry (IHQ). A total of 20 samples were obtained. A 675 bp fragment of the S. apella COX-2 promoter region was obtained, and it was 99.2% and 68.2% similar to H. sapiens and S. boliviensis, respectively. Similar to humans, several transcription factors and cis-regulatory element binding sites were identified in the S. apella sequence. MSP revealed that all samples were methylated. However, IHQ results demonstrated positive COX-2 expression in all pre-neoplastic and tumoral samples. The results suggest that the analyzed fragment is not crucial in COX-2 regulation of GC in S. apella.</p></div

Expression pattern of Cdkn2b and its regulators in canine mammary tumors

Federal University of Pará. Biological Science Institute. Molecular Biology Laboratory. Belém, PA, Brazil / Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura de Tecidos e Citogenética. Ananindeua, PA, Brasil.Federal University of Pará. Biological Science Institute. Molecular Biology Laboratory. Belém, PA, Brazil.Federal University of Pará. Oncology Research Center. Belem, PA, Brazil.Federal Rural University of Amazonia. Health and Animal Production Institute. Animal Pathology Laboratory. Belém, PA, Brazil.Federal Rural University of Amazonia. Health and Animal Production Institute. Animal Pathology Laboratory. Belém, PA, Brazil.Ophir Loyola Hospital. Molecular Biology Laboratory. Belém, PA, Brazil / Federal University of Pará. Molecular Biology and Human Cytogenetics Laboratory. Belém, PA, Brazil.Federal University of Pará. Biological Science Institute. Molecular Biology Laboratory. Belém, PA, Brazil.Federal University of Pará. Biological Science Institute. Molecular Biology Laboratory. Belém, PA, Brazil.Background/Aim: In female dogs, mammary cancer is the most frequent cancer type, accounting for 50% of all tumors affecting these animals. Amongst the commonly altered genes in cancer is the cell-cycle regulator cyclin-dependent kinase inhibitor 2B (Cdkn2b), whose expression is negatively regulated by protein products of BMI1 proto-oncogene (Bmi1), MYC proto-oncogene (Myc) and T-box gene transcription factor 2 (Tbx2) genes. Considering this, the aim of this study was to evaluate the expression pattern of the Cdkn2b gene and these regulators in canine mammary tumors of dogs from Northern Brazil (Belém, Pará). Material and Methods: Gene expression in samples from 33 animals was assessed by real-time polymerase chain reaction. To check the influence of methylation on gene expression, bisulfite sequencing polymerase chain reaction was also performed. Results: All studied genes, except Cdkn2b, were found at increased expression levels in tumor tissue when compared with control samples. No correlation between expression and methylation data was observed. Conclusion: Our results suggest these markers may have a diagnostic value in the veterinary clinic

An update on the epigenetics of glioblastomas

Federal University of Pará. Institute of Biological Sciences. Molecular Biology Laboratory. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Sciences. Molecular Biology Laboratory. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Sciences. Molecular Biology Laboratory. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Sciences. Molecular Biology Laboratory. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Sciences. Molecular Biology Laboratory. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Sciences. Molecular Biology Laboratory. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Sciences. Molecular Biology Laboratory. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Sciences. Molecular Biology Laboratory. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Sciences. Human Cytogenetics Laboratory. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Federal University of Pará. Institute of Biological Sciences. Molecular Biology Laboratory. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Sciences. Molecular Biology Laboratory. Belém, PA, Brazil.Glioblastomas, also known as glioblastoma multiforme (GBM), are the most aggressive and malignant type of primary brain tumor in adults, exhibiting notable variability at the histopathological, genetic and epigenetic levels. Recently, epigenetic alterations have emerged as a common hallmark of many tumors, including GBM. Considering that a deeper understanding of the epigenetic modifications that occur in GBM may increase the knowledge regarding the tumorigenesis, progression and recurrence of this disease, in this review we discuss the recent major advances in GBM epigenetics research involving histone modification, glioblastoma stem cells, DNA methylation, noncoding RNAs expression, including their main alterations and the use of epigenetic therapy as a valid option for GBM treatment

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data