Abstract
OBJECTIVES: To explore the association between GPSM2 expression level and gastric cancer progression and analyze the functional pathways and action mechanism of GPSM2. METHODS: We analyzed GPSM2 expression levels in gastric cancer tumors based on data from the GEPIA database and the clinical data of 109 patients. Public databases enrichment analysis were used to assess the impact of GPSM2 expression level on survival outcomes and the functional pathways and action mechanism of GPSM2. We further observed the effects of GPSM2 knockdown and overexpression on proliferation, migration and apoptosis of MGC803 cells using CCK-8 assay, colony formation assay, flow cytometry and immunoblotting and on the growth of MGC803 cell xenografts in nude mice. RESULTS: Bioinformatic analysis and immunohistochemical staining of the clinical specimens both revealed high GPSM2 expressions in gastric cancer (P<0.01). A high GPSM2 expression was significantly correlated with T3-4 stages, N2-3 stages, a carcinoembryonic antigen (CEA) level ≥5 μg/L, and a carbohydrate antigen (CA) 19-9 level ≥37 kU/L (P<0.05). Cox regression analysis identified high GPSM2 expression as an independent risk factor affecting 5-year survival of the patients (P<0.05). Gene ontology (GO) analysis suggested that GPSM2 was involved in cell cycle regulation. In MGC803 cells, GPSM2 overexpression significantly promoted cell proliferation and G1/S transition and xenograft growth in nude mice. KEGG pathway enrichment analysis indicated that GPSM2 executed its biological functions by regulating the p53 signaling pathway, which was confirmed by the results of immunoblotting experiments showing suppression of p53 signaling pathway activity in GPSM2-over expressing MGC803 cells. CONCLUSIONS: GPSM2 is highly expressed in gastric cancer to affect patient prognosis by promoting tumor cell proliferation and G1/S transition possibly via inhibiting the p53 pathway.