Thrombospondin-2 Holds Prognostic Values and is Associated with the Metastasis and Mismatch Repair Process in Gastric Cancer

Abstract Background: The study aims to investigate the expression level of Thrombospondin 2 (TSP2) in Gastric Cancer (GC) and determine the relationship between TSP2 and clinical characteristics and prognosis.Methods: The online database Gene Expression Profile Interactive Analysis (GEPIA) was used to analyze the mRNA expression level of TSP2 in GC. The Kaplan-Meier plotter prognostic analysis tool was used to evaluate the influence of TSP2 expression on clinical prognosis in GC patients. The expression level of TSP2 was analyzed in paraffin-embedded GC samples and adjacent normal tissues by immunohistochemistry. The relationship between clinicopathological characteristics and prognosis of GC patients. Next, the relationship between clinicopathological characteristics and prognosis of GC patients was assessed. Transwell experiment was used to evaluate the effect of TSP2 on the invasion and migration of HGC27 and AGS cells.Results: Compared with normal tissues, the expression of TSP2 mRNA in GC was significantly up-regulated, and it was closely related to the clinical stage of GC. The high expression of TSP2 significantly affected the OS, FP and PPS of patients with GC. Among them, the expression level of TSP2 did not affect the prognosis of patients with GC in N0 subgroup, but significantly affected the prognosis of patients with GC in N (1+2+3)subgroup. The protein expression level of TSP2 in GC tissue was significantly higher than in normal tissues (P<0.01). The overall survival (OS) rate of patients with high TSP2 expression was lower than the low TSP2 expression group (P=0.013). Knockdown of TSP2 can significantly inhibit the growth of GC cells. Proliferation, migration, invasion ability, and TSP2 expression level significantly correlate with mismatch repair genes such as PMS2, MSH6, MSH2, and MLH1 (P<0.05).Conclusion: The expression of TSP2 in GC is significantly increased, closely related to the metastasis and mismatch repair process of GC patients and affected GC patients' prognosis. It is a potential marker and treatment target for the prognosis of GC patients.