The prognosis value of proteasome activator subunit 3 expression in gastric cancer.

ABSTRACT

Gastric cancer (GC) is a highly aggressive malignant tumor, and, therefore, the prognosis evaluation of this disease is important. Proteasome activator subunit 3 (PSME3) is highly expressed in GC; however, its exact role in GC has yet to be clarified. The gene expression profiles for GC were downloaded to find a candidate prognostic biomarker, and PSME3 was selected. The expression level of the PSME3 gene in GC tissues was analyzed using a public database. The biological processes and signal pathways that PSME3 was involved in were further analyzed. Immunohistochemical staining of 181 GC tissues was performed to detect the expression of the PSME3 protein. The correlation between PSME3 expression and GC prognosis and its clinical and pathological parameters were investigated. It was found that PSME3 mRNA expression was higher in GC than in adjacent gastric tissues, and high PSME3 expression was significantly correlated with tumor stage, histological subtype, lymph node metastasis status, and Helicobacter pylori infection in patients with GC (all p<0.01). Bioinformatics showed that PSME3 mainly played an oncogenic role in the development of GC by regulating the cell cycle and inhibiting apoptosis. The PSME3 protein was overexpressed in 64.6% (117/181) of the analyzed samples, and overexpression of PSME3 was associated with a significantly poor prognosis. In addition, multivariate analysis suggested that PSME3 overexpression, tumor, node, metastasis stage, and tumor size are independent prognostic biomarkers for GC. We conclude that the overexpression of PSME3 was associated with a poor prognosis in patients with GC, and PSME3 might play an oncogenic role in the occurrence and development of GC.