Integrative analysis of S100A2 in pan-cancer and verification in glioma

Abstract S100A2 (S100 Calcium Binding Protein A2) is one of the 25 members of S100 protein family. S100A2 was involved with suppress tumor invasion and cancer progression. However, there was no pan-cancer analysis of S100A2 reported recently. This study sought to identify the effect of A100A2 on the immunological role and prognosis in pan-cancer. The expression of S100A2 was analyzed in 33 different cancers by using TCGA and GTEx database. The analysis of S100A2 gene expression was performed using the glioma samples from the cancer genome atlas (TCGA)-lower grade glioma and glioblastoma (GBMLGG) cohort. We assessed the association of S100A2 expression with molecular and immune subtypes in pan cancer. Then, we explored the S100A2-bingding proteins, the biological and molecular functions of S100A2, diagnosis and prognosis of S100A2 in pan cancer. Subsequently, based on the pan cancer analysis, we narrowed the focus to the relationship of S100A2 expression with clinical characteristics, overall survival (OS), disease-specific survival (DSS), and progression- free interval (PFI) in the GBMLGG. In addition, we analyzed the correlation of S100A2 and immune cells in pan cancer from the TIMER2 database. S100A2 was differently expressed in pan cancer, and it was associated with molecular subtypes and immune subtypes in various cancers. The infiltration levels of CD8+ T cells, CD4+ T cells were associated with S100A2 expression. Pan cancer cox regression analysis showed that S100A2 high expression can cause a poor prognosis. Further investigation showed that the higher expression S100A2 had a worse OS, DSS and PFI in some clinical subgroups of GBMLGG. Our results showed that S100A2 expression was linked to WHO grade, IDH status, gender, age, and histological type of GBMLGG. We also found that the first 50 important genes that positively correlated with S100A2 expression in GBMLGG. In conclusion, our research provides a molecular biomarker for the therapy in GBMLGG.