# Exploration of signature based on T cell-related genes in stomach adenocarcinoma by analysis of single cell sequencing data

## TL;DR

This study identifies a T cell-related gene signature in stomach cancer that predicts prognosis and immunotherapy response using single-cell RNA sequencing data.

## Contribution

A novel T cell-related gene signature is developed to predict survival and immune features in gastric cancer patients.

## Key findings

- A T cell-related gene signature was constructed and used for risk grouping in gastric cancer.
- Higher-risk groups showed more pro-tumor pathways and poorer immunotherapy response.
- Differences in immune cell infiltration were observed between risk groups.

## Abstract

Background: Gastric cancer (GC) is a leading reason for the death of cancer around the world. The immune microenvironment counts a great deal in immunotherapy of advanced tumors, in which T cells exert an indispensable function.

Methods: Single-cell RNA sequencing data were utilized to characterize the expression profile of T cells, followed by T cell-related genes (TCRGs) to construct signature and measure differences in survival time, enrichment pathways, somatic mutation status, immune status, and immunotherapy between groups.

Results: The complex tumor microenvironment was analyzed by scRNA-seq data of GC patients. We screened for these T cell signature expression genes and the TCRGs-based signature was successfully constructed and relied on the riskscore grouping. In gene set enrichment analysis, it was shown that pro-tumor and suppressive immune pathways were more abundant in the higher risk group. We also found different infiltration of immune cells in two groups, and that the higher risk samples had a poorer response to immunotherapy.

Conclusion: Our study established a prognostic model, in which different groups had different prognosis, immune status, and enriched features. These results have provided additional insights into prognostic evaluation and the development of highly potent immunotherapies in GC.