Role of ST7‑AS1 in the malignant progression of gastric cancer (GC) andits molecular mechanisms were investigated. ST7‑AS1 level in GC tissues and matchednormal tissues was determined by quantitative real‑time polymerase chain reaction (qRT‑PCR).Its level in GC patients presenting different tumor stages and tumor sizes wasdetermined. Subsequently, ST7‑AS1 level in epithelial cells of gastric mucosaand GC cell lines was examined. Cellular behavior of GC cells, including viability,apoptosis, migration, invasion and cell cycle, influenced by ST7‑AS1 was evaluated.The interaction between ST7‑AS1 and EZH2 was assessed by RNA immunoprecipitation (RIP)assay. The involvement of EZH2 in the progression of GC mediated by ST7‑AS1 wasidentified. ST7‑AS1 was upregulated in GC tissues and cell lines.... Its level waspositively correlated to tumor stage and tumor size of GC. Knockdown of ST7‑AS1attenuated proliferative, migratory and invasive abilities, arrested cell cycleprogression and induced apoptosis of GC cells. EZH2 was identified to interactwith ST7‑AS1, which attenuated the regulatory effects of ST7‑AS1 on migratoryand invasive abilities of GC cells. Upregulated ST7‑AS1 in GC accelerated proliferation,migration and invasion, and inhibited apoptosis, thus aggravating the progressionof GC.