Identification CXCL9 is a Potential Prognostic Biomarker in Ovarian and Gastric Cancer and is Correlated with Immune Infiltrates
Abstract Background CXCL9 also known as an interferon gamma-inducible chemokine that belonging to the CXC chemokine family. It plays a role in promoting chemotaxis, inducing leukocyte differentiation and multiplication, and triggering tissue extravasation. Methods The TIMER (Tumor Immune Estimation Resource) and cancer microarray database Oncomine were used to dig at CXCL9 expression. The clinic prognostic level of CXCL9 was evaluated via Kaplan-Meier plotter. Then, Using TIMER and GEPIA, we investigated whether CXCL9 expression impacted cancer immune infiltrates. Results CXCL9 expression has been found to be significantly lower in ovarian and gastric cancers relative to normal tissues. In patients with ovarian cancer (OS HR = 0.78, P = 0.0017; PFS HR = 0.85, R = 0.015) and gastric cancer (OS HR = 0.55, P = 1.1e-08; PFS HR = 0.58, R = 7.6e-07), low CXCL9 expression was correlation to PFS (progression-free survival) and OS (poor overall survival). Furthermore, in OV and GC, CXCL9 was shown to have a close interaction with tumor-infiltrating immunity cells (B cells, CD4 + and CD8 + T cells, macrophages, neutrophils, and dendritic cells). CXCL9 expression, on the other hand, was shown to be closely related to several immune markers. Conclusion In OV and GC, CXCL9 mRNA level is strongly associated with prognosis and levels of penetration tumor-infiltrating immunity cell. The CXCL9 expression may also play a role in controlling TAMs (tumor-associated macrophages), DCs (Dendritic cells), CTLs (cytotoxic lymphocytes), and NK (natural killer) cells in OV and GC. CXCL9 may be seen as an independent marker that assesses the prognosis in OV and GC patients. Besides, CXCL9 expression level also can assess the immune cell subtypes of tumor microenvironment in OV and GC.