2025-06-252025-06-252024-08SILVA, Valéria Cristiane Santos da. Análise da expressão gênica de pacientes com adenocarcinoma gástrico associado ao vírus Epstein-Barr. Orientador: Fabiano Cordeiro Moreira. 2024. 63 f. Dissertação (Mestrado em Biotecnologia) - Universidade Federal do Pará, Instituto de Ciências Biológicas, Belém, 2025. Disponível em: https://repositorio.ufpa.br/jspui/handle/2011/17548. Acesso em:.https://repositorio.ufpa.br/jspui/handle/2011/17548Infection with the Epstein-Barr virus (EBV) is one of the risk factors for gastric cancer (GC). Epstein-Barr is a virus with oncogenic activity and was the first to be associated with malignant diseases such as lymphomas and carcinomas. Thus, EBV detection can be performed both by in situ hybridization and, currently, by using RNA sequencing techniques to identify the presence of viral genes in samples. In this context, aiming to better understand the EBV-positive subtype, this study proposed a molecular classification based on RNA sequencing of 76 tumor samples from patients diagnosed with GC. RNA sequencing of the samples was performed, and molecular classification was done using the Kraken2 software. Of the 76 samples, 8 were considered positive according to the adopted method. Subsequently, to understand the different mechanisms by which EBV might be acting in gastric cancer, we analyzed the patterns of human gene expression in samples classified as positive and negative. In our study, there are approximately 834 differentially expressed genes, of which 92 have an AUC greater than 0.85. These genes are associated with tumor progression, cellular metabolism, and innate and adaptive immunity. Additionally, viral genes expressed in the positive samples were evaluated, and we found manifestations of both lytic phase and latent phase genes. Finally, our study presents an efficient strategy for the molecular classification of EBV-positiveAcesso AbertoAttribution-NonCommercial-NoDerivs 3.0 Brazilhttp://creativecommons.org/licenses/by-nc-nd/3.0/br/Vírus Epstein-BarrNeoplasias gástricasAspectos molecularesRNA-seqHerpesviridaeAdenocarcinomaExpressão gênicaHerpesvirus humano 4Infecções por vírus Epstein-BarrCarcinogenosVírus oncogênicosDissertaçãoCNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA MOLECULAR E DE MICROORGANISMOSBIOTECNOLOGIA MOLECULAR