Dados do Resumo

Título

EXPLORING THE VIROME IN GASTRIC ADENOCARCINOMA THROUGH RNA-Seq DATA

Introdução

Gastric cancer (GC) is a malignant neoplasm of the gastrointestinal tract, ranking fifth in incidence and third in cancer mortality globally. The quest for effective molecular biomarkers for early detection and screening of GC remains challenging. In recent decades, high-throughput sequencing studies have investigated the mechanisms of GC carcinogenesis, focusing on the relationship between specific microbiomes and the development of this neoplasm.

Objetivo

To characterize the virome in tumor and non-tumor tissues of patients with gastric adenocarcinoma using RNA-Seq data.

Métodos

The study was approved by the Ethics Committee of the João de Barros Barreto University Hospital (CAAE 47580121.9.0000.5634). We included tumor tissue samples (n = 80) and adjacent tissue samples (n = 60) from patients with gastric adenocarcinoma. Total RNA was extracted using TRIzol® reagent and assessed for concentration and integrity. RNA libraries were prepared with the TruSeq Stranded Total RNA kit (Illumina, USA) and sequenced in paired-end mode on the NextSeq®500 platform (Illumina, USA). Sequenced reads were processed for quality and mapped against the Reference Viral DataBase (v28.0) using Kraken2 software. Kraken2 reports were integrated and analyzed in RStudio (v2024.04.2). Virome abundance and alpha diversity analyses were conducted at the genus level using the phyloseq (v.1.42.0), microbiome (v.1.20.0), and vegan (v.2.6.6) packages.

Resultados

A total of 337 viral genera were identified in both tumor and adjacent tissues, with 102 genera common to both. In tumors, 63.8% of the virome composition was composed of bacteriophages, while eukaryotic viruses accounted for 11.3%. In adjacent tissues, bacteriophages made up 61% and eukaryotic viruses 9.2%. Tumors exhibited a higher abundance of viral reads compared to adjacent tissues (Wilcoxon, p = 0.022). Among tumors, the most abundant viral genera were Lymphocryptovirus, Cytomegalovirus, and Betabaculovirus, whereas adjacent tissues showed greater predominance of Betabaculovirus, Lymphocryptovirus, and Orthotospovirus. Alpha diversity analyses revealed significant differences between tumor and adjacent tissues in richness (Wilcoxon, p = 0.00011), Shannon (Wilcoxon, p = 0.00027), and Simpson (Wilcoxon, p = 0.0039) indices.

Conclusões

This study identified significant differences in the composition and diversity of the virome between tumor and adjacent tissues in gastric adenocarcinoma. The predominance of bacteriophages, variations in viral genera, and differences in alpha diversity suggest a potential association between the virome and gastric carcinogenesis. These findings underscore the importance of exploring the virome as a potential biomarker for gastric cancer.

Financiador do resumo

Fundação Amazônia de Amparo a Estudos e Pesquisas (FAPESPA); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Palavras Chave

Virome; Gastric Adenocarcinoma; RNA-seq