Exploring the prognostic features and immune landscape of exosome-related genes in breast cancer metastasis based on bioinformatics methods

Abstract Background Breast cancer (BRCA) is a tumor with a poor prognosis and easy metastasis. Exosomes have been proven to be involved in cell-to-cell communication, cell migration, angiogenesis, and other processes and are closely related to the immune microenvironment of cancer. However, its role in BRCA metastasis is still unclear. Methods This paper attempted to explore the role of exosome-related genes in BRCA metastasis from the perspective of computational biology. We downloaded 1724 exosome-related genes from the ExoCarta database. And 810 samples of metastatic and non-metastatic BRCA were downloaded from the TCGA database. 600 samples with positive correlation with metastasis were screened by WGCNA analysis of differentially expressed genes. Furthermore, three genes (JUP, CAPZA1, and ARVCF) that are significantly related to prognosis were screened by single-factor Cox regression and LASSO-Cox regression, and a risk-scoring model related to metastasis was constructed. According to the median risk score, the samples were divided into a high-risk group and a low-risk group, and then the infiltration abundance and immune function of immune cells were analyzed by CIBERSORT and ssGSEA methods, respectively. In addition, we also evaluated the differences in immune escape and drug sensitivity between the high-risk group and the low-risk group by Tide and the oncoPredict package, respectively. Results We identified that the signature of three exosome-related genes was closely related to BRCA metastasis. There were significant differences in survival rate, immune cell infiltration, and immune function between the high-risk group and the low-risk group according to the risk score. It was worth noting that M0 and M1 macrophages play an important role in BRCA metastasis. Finally, this paper also found that there were significant differences in the sensitivity of the two groups to multiple drugs. Conclusions The risk model of exosome-related genes related to BRCA metastasis is closely related to immune cells and immune function during BRCA metastasis, which may be helpful in improving the immunotherapy of BRCA.