lncRNA DSCR8 mediates miR-137/Cdc42 to regulate gastric cancer cell proliferation, invasion, and cell cycle as a competitive endogenous RNA.

lncRNA DSCR8 (Down syndrome critical region 8) is involved in progression of many cancers, but its specific role in gastric cancer (GC) is still unclear. Here, qRT-PCR detected upregulated expression of DSCR8 and Cdc42 and downregulated expression of miR-137 in GC. The protein expression level of Cdc42 in GC was upregulated as tested by western blot. Statistical analysis showed that DSCR8 was closely associated with some malignant clinicopathological features (such as tumor size, metastasis, and stage) in GC patients. Fluorescence in situ hybridization showed that DSCR8 was localized in the nucleus and cytoplasm. Dual-luciferase reporter gene, RNA immunoprecipitation, and biotin pull-down assays showed that DSCR8 could bind to miR-137 could bind to Cdc42. In vitro and in vivo assays showed that DSCR8 could promote proliferation, invasion, and the cycle of GC cells and inhibit cell apoptosis. In addition, a rescue experiment showed that DSCR8 regulated progression of GC cells via miR-137. Furthermore, DSCR8 regulated Cdc42 in GC cells by inhibiting miR-137. Taken together, these data indicated that DSCR8 could adsorb miR-137 to reduce its inhibitory effect on Cdc42 expression, thereby promoting the progression of GC cells and regulating the cell cycle. These results provide a novel direction for DSCR8 as a target of GC.