Overexpression of SEZ6L2 Is associated with unfavourable prognosis and Immune infiltrates in breast cancer

Abstract

Abstract Background Breast invasive carcinoma (BRCA) is the most usual global malignancya and the leading cause of high proportion deaths. SEZ6L2 was revealed to be expressed in different cancers varies. Nevertheless, the prognostic values of SEZ6L2 and association with immune infiltrates in BRCA are still unclear. Methods In our study, the transcriptional expression profiles of SEZ6L2 and clinical information of BRCA patients were gained from TCGA platform and HPA databases. Kaplan-Meier method and Cox regression analysis was conducted to assess the influence of SEZ6L2 on overall survival(OS) and Progress Free Interval(PFI) in BRCA patients. The biological functions and potential mechanism of SEZ6L2 were investigated by functional enrichment analyses and network analysis of protein-protein interactions (PPI). In the end, tumor immune estimation resource (TIMER) and tumor-immune system interaction database (TISIDB) were chosen to investigate the relevance of SEZ6L2 to tumor-infiltrating immune cells. Results The expression of SEZ6L2 was significantly up-regulated in BRCA tissues compared with adjacent normal tissues. Overexpression SEZ6L2 is associated with poor prognosis. Multivariate Cox analysis identified SEZ6L2 as an independent poor prognostic factor in BRCA. Functional enrichment analyses revealed that enriched pathways included multiple pathways included the complement activation, humoral immune response mediated by circulating immunoglobulin, protein activation cascade, immunoglobulin complex and immunoglobulin. In addition, the SEZ6L2 expression was closely correlated to the infiltration levels of tumor-infiltrating immune cells(TIICs), included CD8 + T cells, CD4 + T cells, B cell, macrophages, neutrophils, and dendritic cells. Furthermore, we revealed a potential relationship between SEZ6L2 expression and the diverse marker genes of TIICs. Conclusion Increased SEZ6L2 mRNA expression is significantly correlated with negative prognosis and immune infiltrates in breast invasive carcinoma. SEZ6L2 maybe a novel prognostic biomarker and potential immune therapy target in BRCA.