High infiltration level of a prognostic improvement associated T cells is favorable for the prognosis of patients with gastric adenocarcinoma.

Gastric cancer is the fifth most common cancer and the third leading cause of cancer-related deaths worldwide. Currently, research on the tumor microenvironment of gastric cancer remains to be developed. In this study, we obtained scRNA-seq data of gastric cancer from the GEO database, and used the Seurat package for clustering. We used the Bayesian cell Proportion Reconstruction algorithm to calculate the cell subpopulation content in TCGA samples, and combined it with TCGA survival data to perform Kaplan-Meier and univariable Cox analyses. We further performed multivariable Cox regression analysis incorporating age, sex, TNM stage, and histological type to evaluate the independent prognostic value of PIA T-cells. We found that a prognostic improvement associated T cells (PIA T-cells) had a better prognosis in gastric adenocarcinoma tissues with higher levels of PIA T-cells. To further characterize the biological identity of this population, we analyzed canonical T-cell functional markers and found that PIA T-cells exhibited a distinct phenotypic profile (CD4(low/negative), CD8A(moderate), GZMB(moderate), IFNG(low)), distinguishing them from other T-cell subsets. Unlike other T cell subpopulations, PIA T-cells expressed significantly higher levels of eight genes (ASPM, ATAD2, CENPF, DUT, MKI67, NUSAP1, TOP2A, and TYMS). The study of PIA T-cells may provide insights into gastric cancer tumor microenvironment-related treatments and inform future therapeutic strategies.