Profiles of tumor-infiltrating immune cells and prognostic genes associated with the microenvironment of bladder cancer

The immune microenvironment in bladder cancer (BC) and its significance still remain poorly understood. The present work aims to investigate tumor-infiltrating immune cells (TIICs) and prognostic genes associated with the tumor microenvironment (TME) of BC. The immune and stromal scores of BC samples from The Cancer Genome Atlas database were downloaded from the ESTIMATE website. Based on these scores, BC samples were assigned to the high and low score groups and 429 intersecting differentially expressed genes were identified. Functional enrichment analysis further revealed that these genes dramatically participated in the immune-related biological processes and signaling pathways. Two TME-related genes, angiotensin II receptor type 2 (AGTR2) and sclerostin domain containing 1 (SOSTDC1), were identified to establish an immune-related risk model using Cox regression analyses. Intriguingly, patients with high-risk scores had poor outcomes (p < 0.001). The areas under the curve for the risk model in predicting 3- and 5-year survival rates were 0.692 and 0.707, respectively. Kaplan-Meier survival analysis showed that the expression of AGTR2 and SOSTDC1 significantly correlated with the overall survival of BC patients. Additionally, 22 TIICs in the BC microenvironment were analyzed with the CIBERSORT algorithm. This study indicated that the effective components of TME affected the clinical outcomes of BC patients and might provide a basis for the development of new immunotherapies for BC patients.