Objective:This study aims to investigate the expression of long intergenic noncoding RNA 460(linc00460)in gastric cancer and its relationship with clinicopathological features and prognosis of gastric cancer patients. Methods:Differential expression of linc00460 was systematically evaluated based on the Cancer Genome Atlas(TCGA)gastric cancer database. Then 88 patients who underwent gastric cancer surgery were included to verify TCGA results by RT-qPCR. The linc00460 expression in AGS,HGC-27,MKN45,MGC-803,and normal gastric epithelial GES-1 were detected by RT-qPCR. Gene set enrichment analysis(GSEA)was used to predict the regulation genes of linc00460. AGS cells were transfected with pcDNA-linc00460 and pcDNA3.1,respectively. Western blot was used to detect the expression of related proteins and CCK-8 method to detect the proliferation of cells in the two groups. Results:We found and confirmed that linc00460 was highly expressed in gastric cancer tissue samples and cells(P < 0.05);moreover,high linc00460 expression was associated with M-stage;there was a strong negative correlation between the expression of linc00460 and the overall survival of patients with gastric cancer(P < 0.05);furthermore,univariate and multivariate analysis of the Cox proportional hazards model confirmed that linc00460 was an independent predictor of gastric cancer-related survival(P < 0.05). The linc00460 high-expression samples in TCGA GC datasets were enriched in the regulation of DNA damage response signal transduction by P53 class mediator,the positive regulation of signal transduction by P53 class mediator,the regulation of meiotic nuclear division and the positive regulation of nuclear division gene sets. The expression level of linc00460 in the pcDNA-linc00460 transfected AGS cells was significantly higher than that of pcDNA3.1 group(P < 0.05). Western blot results showed that linc00460 could down-regulate the P53 and up-regulate Bcl-2 and Cyclin B1 expressions. CCK-8 results showed cell proliferation in AGS cells of the pcDNA-linc00460 group was significantly higher than that in the pcDNA3.1 group(P < 0.05). Conclusion:Linc00460 is highly expressed in gastric cancer tissues,and patients with high linc00460 level result in a poor prognosis. Linc00460 may promote the growth of gastric cancer cells by up-regulating the P53 signaling pathway,and linc00460 may be involved in the malignant progression of gastric cancer.