Biglycan Overexpression Predicts Poor Prognosis of Gastric Cancer

Abstract Background: Biglycan (BGN) encodes an extracellular matrix (ECM) proteoglycan. However, the potential diagnostic and prognostic value of BGN in gastric cancer (GC) have not yet been reported. In this analysis, BGN expression in GC was evaluated across the Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA), and Oncomine databases, and verified using immunohistochemistry (IHC). The relationship between BGN expression and clinicopathological parameters was assessed by chi-square test and logistic regression. We analyzed the prognostic value of BGN. Then, Gene set enrichment analysis (GSEA) was used to screen the signaling pathways involved in high BGN expression datasets in GC. Finally, CIBERSORT was used to evaluate the infiltration of immune cells in GC tissues, and the correlation between BGN and infiltrating immune cells was analyzed. Results: The results showed that the mRNA levels of BGN were significantly up-regulated in GC compared with normal tissues (all P <0.001). The Kaplan-Meier plotter online database suggested that patients with high BGN expression had a poor prognosis ( P =1.3e-10). In addition, using gene sets analysis, we found that pathways of bladder cancer, Wnt-signaling, TGF-beta signaling, and ECM-receptor interaction were differentially activated in high-expression BGN tissues. Furthermore, CIBERSORT analysis for the proportion of TICs revealed that macrophages M2 was positively correlated with BGN expression. Conclusions: In conclusion, BGN can be used as potential diagnostic markers of GC, and immune cell infiltration plays an important role in the occurrence and progression of GC. The finding may have significant implication for the diagnosis, prognosis and treatment of GC.