Pan-Cancer Analysis Reveals SOX2 as a Promising Prognostic and Immunotherapeutic Biomarker Across Various Cancer Types, Including Pancreatic Cancer

SOX2 is associated with the initiation, growth, and progression of various tumors and is related to stem cells. However, further studies of SOX2 in a pan-cancer context are warranted. In this study, we obtained pan-cancer and clinical data from TCGA, GTEx, STRING, and TISIDB databases and we analyzed the relationship between SOX2 expression levels and changes in gene diagnostics and survival prognosis. Additionally, we compared the expression levels of SOX2 in pancreatic cancer and healthy pancreatic tissues using Wilcoxon's rank-sum test. Functional enrichment analysis was conducted to identify potential signaling pathways and biological functions. To determine the prognostic value, we used the area under the curve (AUC) and Cox regression analysis. We further developed nomograms to predict overall survival at 1, 6, and 12 months after cancer diagnosis. Moreover, we assessed immune cell infiltration using single-sample gene set enrichment analysis. The methylation status of SOX2 was analyzed using the UALCAN and MethSurv databases. Furthermore, we verified the differential expression of SOX2 in pancreatic cancer cell lines by western blotting and quantitative polymerase chain reaction. We also confirmed the effect of SOX2 on the invasion and migration of pancreatic cancer cells using transwell and scratch assays. The biological effects were confirmed using a clone-formation assay. Our findings suggest that SOX2 is highly expressed in various tumor tissues and has potential clinical significance. It can be used as a new biomarker for pancreatic adenocarcinoma and plays a crucial role in immune infiltration.