PECAM-1 is a prognostic-related biomarker and correlated with immune infiltrates in breast cancer

Abstract Background: Breast invasive carcinoma (BRCA) is the primary cause of cancer-associated mortality worldwide. Platelet endothelial cell adhesion molecule 1 (PECAM-1) has been implicated in a number of important biological processes. However, the interrelation between PECAM-1 gene expression, tumor immunity, and prognosis of patients with BRCA is unclear. The current study is aimed to analyze the expression and clinical significance of PECAM-1 in breast cancer and the correlation between PECAM-1 and immune infiltrations. Methods: The differential expressions of PECAM-1 in breast cancer tissues and normal tissues were evaluated via exploring TIMER, Oncomine and UALCAN databases; the relationship within expression level of PECAM-1 and outcome of breast patients was evaluated via Kaplan-Meier plotter and PrognoScan; the methylation of PECAM-1 were investigated through the MethSurv platform; the correlation between PECAM-1 and tumor immune cell infiltration was further investigated by TIMER and GEPIA databases; the correlation between PECAM-1 and gene makers of immune infiltration were checked using TIMER and GEPIA. Results: There were significant differences in PECAM-1 expression levels between breast invasive carcinoma tissues and adjacent normal tissues. Low PECAM-1 expression was significantly related to poor overall survival, progression-free survival and distant metastasis free survival in patients with breast cancer. In DNA methylation level, PECAM-1 hypermethylation in three CpG sites (cg20830094, cg00427260 and cg00879592) showed poor survival in breast cancer. PECAM-1 expression exhibited significantly positive correlations with the levels of infiltrated B cell, CD4+T cells, CD8+ T cells, neutrophils, macrophages, and dendritic cells in breast cancer. Furthermore, PECAM-1 expression is positively correlated with multiple immune gene makers in breast cancer.Conclusion: The expression of PECAM-1 can serves as a prognostic biomarker in breast invasive carcinoma and is correlated with immune infiltrates.