Abstract
Gastric and colorectal cancers are common malignancies with high incidence and mortality worldwide. Early detection and individualized treatment are crucial to improving patient outcomes. Glutathione peroxidase-8 (GPX8), a member of the glutathione peroxidase family, emerges as a potential target for intervention in the treatment of various cancers. This study investigated the potential of GPX8 as a prognostic marker in patients with gastric and colorectal adenocarcinoma. The study employed a multi-omics approach to analyze GPX8 expression in both tumor and adjacent normal tissue of stomach adenocarcinoma (STAD), colon adenocarcinoma (COAD) and rectum adenocarcinoma patients. The Cancer Genome Atlas database was used to download the microarray data of GPX8 and clinical information for cancer patients. The TIMER database and TNMplot database were used to systematically evaluate the association of GPX8 with tumor-infiltrating lymphocytes in adenocarcinoma. Immunohistochemistry is used to detect GPX8 expression in clinical tumors and adjacent normal tissues. Univariate Cox analysis was performed to explore the relationship between GPX8 expression, immune cell levels, and the prognosis in cancer patients. GPX8 was significantly upregulated in tumor tissue and was associated with a poor prognosis in STAD and COAD patients. Furthermore, high GPX8 expression was found to be correlated with a higher degree of CD4+ T cell-infiltrating in COAD and neutrophil-infiltrating in STAD, indicating that GPX8 may play a role in immune evasion in cancer progression. This study highlights the potential of GPX8 as a prognostic marker in STAD and COAD, providing valuable insight into the development of personalized treatment strategies for cancer patients.