Identification of molecular feature in tumor immune microenvironment of bladder cancer patients.

e16500 Background: Bladder cancer (BC) is the most common malignant tumor of the urinary system, with various heterogeneity. Immunotherapy has become one of the hot areas of cancer research. Tumor immune microenvironment is closely related to prognosis and immunotherapy effect. Therefore, Immune cell infiltration analysis is necessary for the prognosis and treatment of BC. Methods: In this study, we analyzed IMvigor210 dataset, which included complete expression data and detailed clinical information from a cohort associated with Bladder Urothelial Carcinoma (BLCA) immunotherapy. The dataset was divided into two groups based on tumor remission after immunotherapy, including 68 remission samples and 230 stable samples. The CIBERSORT program package was used for immune invasion analysis to compute the relative proportion of immune cells in the tumor tissue from tissue gene expression profiles. Results: Significant results of differentially immune cells proportion were obtained in 126 BC patients by CIBERSORT analysis ( p< 0.05). Compared with the stable group, the number of resting memory CD4+ T cells decreased and the number of CD8+T cells increased in the remission group. The relative proportion of immune cells in tumor microenvironment has certain influence on the occurrence and development of tumor. Conclusions: Memory CD4+ T cells in the resting state did not promote the activation and proliferation of CD8+ T cells, whereas resting memory CD4+ T cells were associated with poor outcome. The increased level of CD8+ T cells in tumor microenvironment was associated with the anti-tumor effect and improved prognosis of various cancers. The results indicate that resting memory CD4+ T cells and CD8+ T cells may be the target of immunotherapy.