Identification of a coagulation‐related signature correlated with immune infiltration and their prognostic implications in lung adenocarcinoma

BACKGROUND: Lung adenocarcinoma (LUAD) is a fatal form of lung cancer with a poor prognosis. Coagulation system had been confirmed closely related to tumor progression and the hypercoagulable state encouraged the immune infiltration and development of tumor cells, leading to a poor prognosis in cancer patients. However, the use of the coagulation‐related genes (CRGs) for prognosis in LUAD has yet to be determined. In this study, we constructed an immune‐related signature (CRRS) and identified a potential coagulation‐related biomarker (P2RX1). METHODS: We obtained a total of 209 CRGs based on two coagulation‐related KEGG pathways, then developed the CRRS signature by using the TCGA‐LUAD RNA‐seq data via the procedure of LASSO‐Cox regression, stepwise‐Cox regression, univariate and multivariate Cox regression. Grouped by the CRRS, Kaplan–Meier survival curves and receiver operating characteristic curves were drawn for the training and validation sets, respectively. In addition, single‐sample gene set enrichment analysis was exploited to explore immune infiltration level. Moreover, immunophenotypes and immunotherapy grouped by CRRS were further analyzed. RESULTS: We developed an immune‐related signature (CRRS) composed of COL1A2, F2, PLAUR, C4BPA, and P2RX1 in LUAD. CRRS was an independent risk factor for overall survival and displayed stable and powerful performance. Additionally, CRRS possessed distinctly superior accuracy than traditional clinical variables and molecular features. Functional analysis indicated that the differentially high expressed genes in the low‐risk group significantly enriched in T cell and B cell receptor signaling pathways. The low‐risk group was sensitive to anti‐PD‐1/PD‐L1 immunotherapy and displayed abundant immune infiltration and immune checkpoint gene expression. Finally, we identified an independent prognostic gene P2RX1. Low expression of P2RX1 associated with poor overall survival and decreased immune infiltration. CONCLUSIONS: Our study revealed a significant correlation between CRRS and immune infiltration. CRRS could serve as a promising tool to improve the clinical outcomes for individual LUAD patients.