Long non-coding RNAs contribute to the development of human cancers. We compared the long non-coding RNA levels in gastric cancer (GC) and para-cancerous tissues in the Gene Expression Omnibus, and found that small nucleolar RNA host gene 12 (SNHG12) was upregulated in GC tissues. Fluorescence in situ hybridization confirmed that SNHG12 is overexpressed in GC tissues. We then used data from The Cancer Genome Atlas to assess the association of SNHG12 expression with the clinicopathological characteristics and prognosis of GC patients and found that higher SNHG12 expression was associated with a greater tumor invasion depth and poorer survival. In vitro, silencing SNHG12 suppressed GC cell proliferation, migration and invasion, but induced apoptosis and cell cycle arrest. Overexpressing SNHG12 had the opposite effects. In xenografted mice, knocking down SNHG12 reduced GC tumor growth. Taken together, cancer pathway microarray and bioinformatics analyses, RNA pulldown assays, Western blotting and immunohistochemistry revealed that SNHG12 induces GC tumorigenesis by activating the phosphatidylinositol 3-kinase/AKT pathway. SNHG12 may thus be a useful marker for predicting poor survival in GC patients.
Keywords: AKT; PI3K; gastric cancer; lncRNA SNHG12; tumorigenesis.