Selenoprotein GPX3 is a novel prognostic indicator for stomach adenocarcinoma and brain low-grade gliomas: Evidence from an integrative pan-cancer analysis.

BACKGROUND

The antioxidant enzyme is a selenoprotein that transports selenium in blood and maintains its levels in peripheral tissues. Aberrant expression is strongly linked to the development of some tumors. However, there is a scarcity of studies examining the pan-cancer expression patterns and prognostic relevance of .

METHODS

expression levels in normal tissues and multiple tumors were analyzed using TCGA, CCLE, GTEx, UALCAN and HPA databases. Forest plots and KM survival curves were utilized to evaluate the correlation between expression and the outcome of tumor patients. The prognostic value of in LGG was assessed utilizing the CGGA datasets, and that in STAD was tested by TCGA and GEO databases. A nomogram was then constructed to predict OS in STAD using R software. Additionally, the impact of on post-chemoradiotherapy OS in patients with LGG and STAD was evaluated using the KM method. The multiplicative interaction of expression, chemotherapy and radiotherapy on STAD and LGG was analyzed using logistic regression models. The correlation of with the immune infiltration, immune neoantigens and MMR genes were investigated in TCGA cohort.

RESULTS

exhibited downregulation across 21 tumor types, including STAD, with its decreased expression significantly associated with improved OS, DFS, PFS and DSS. Conversely, in LGG, low levels of expression were indicative of a poorer prognosis. Univariate and multivariate Cox models further identified as an independent predictor of STAD, and a nomogram based on expression and other independent factors showed high level of predictive accuracy. Moreover, low expression and chemotherapy prolonged the survival of STAD. In LGG patients, chemoradiotherapy, and chemotherapy, and and chemoradiotherapy may improve prognosis. Our observations reveal a notable connection between and immune infiltration, immune neoantigens, and MMR genes.

CONCLUSIONS

The variations in expression are linked to the controlling tumor development and could act as a promising biomarker that impacts the prognosis of specific cancers like STAD and LGG.