Immune Microenvironment-Related Genes Contribute to Clinical Prognosis in Patients with Triple-Negative Breast Cancer

Abstract

Background:Triple-negative breast cancer (TNBC) is a high-risk breast cancer subtype, which accounts for 15% to 20% of all breast cancers and generally has a poor prognosis. TNBC patients have high recurrence post-surgery and high risk of metastasis to other organs. The tumor microenvironment (TME) plays important roles in the carcinogenesis, development, and metastasis of tumors. Methods: This study aimed to investigate the effects of immune and stromal cell-related genes on TNBC prognosis. The ESTIMATE algorithm was used to calculate the immune/stromal scores of TNBC samples from the GEO database. The samples were divided into high- and low- score groups and the differential expression genes were identified using the limma package within R. Functional enrichment and protein-protein interaction (PPI) network analyses revealed that these genes are primarily involved in immune responses. Results:Survival analysis in both GSE21653 and KM-plotter website showed that 36 genes were significantly related to disease-free survival (DFS) of TNBC. Another survival analysis by R package survival in GSE58812 indicated that 14 genes of 36 were greatly interrelated to DFS of TNBC. Moreover, the expression levels of some of these genes were verified through immunohistochemical staining and RT-qPCR. Finally, four genes importantly associated with TNBC prognosis were identified with Cox-LASSO analysis. Time-dependent receiver-operating characteristic (ROC) analysis displayed an area under the curve (AUC) of 0.95 for one-year survival rate, indicating the four genes performed very well for prognosis prediction. Conclusions:In conclusion, we identified four genes, including BIRC3, CD8A, GNLY and TRIM22, that are possibly associated with the TME and are potential prognostic and therapeutic markers of TNBC.