Gene expression patterns associated with tumor-infiltrating CD4+and CD8+T cells in invasive breast carcinomas

Background: Breast carcinoma is one of the most common tumors in women. The immune microenvironment, especially T cell infiltration, is related to the occurrence and prognosis of breast carcinoma. Objective: This study investigated the gene expression patterns associated with tumor-infiltrating CD4+ and CD8+ T cells in invasive breast carcinomas. Methods: The gene expression data and corresponding clinical phenotype data from the Cancer Genome Atlas Breast Invasive Carcinoma (TCGA-BRCA) were downloaded. The stromal and immune score were calculated using ESTIMATE. The differentially expressed genes (DEGs) with a high vs. low stromal score and a high vs. low immune score were screened and then functionally enriched. The tumor-infiltrating immune cells were investigated using the Cibersort algorithm, and the CD4+ and CD8+ T cell-related genes were identified using a Spearman correlation test of infiltrating abundance with the DEGs. Moreover, the miRNA-mRNA pairs and lncRNA-miRNA pairs were predicted to construct the competing endogenous RNAs (ceRNA) network. Kaplan-Meier (K-M) survival curves were also plotted. Results: In total, 478 DEGs with a high vs. low stromal score and 796 DEGs with a high vs. low immune score were identified. In addition, 39 CD4+ T cell-related genes and 78 CD8+ T cell-related genes were identified; of these, 14 genes were significantly associated with the prognosis of BRCA patients. Moreover, for CD4+ T cell-related genes, the chr22-38_28785274-29006793.1-miR-34a/c-5p-CAPN6 axis was identified from the ceRNA network, whereas the chr22-38_28785274-29006793.1-miR-494-3p-SL C9A7 axis was identified for CD8+ T cell-related genes. Conclusions: The chr22-38_28785274-29006793.1-miR-34a/c-5p-CAPN6 axis and the chr22-38_28785 274-29006793.1-miR-494-3p-SLC9A7 axis might regulate cellular activities associated with CD4+ and CD8+ T cell infiltration, respectively, in BRCA. (c) 2021 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.