MicroRNA-187 regulates gastric cancer progression by targeting the tumor suppressor CRMP1

Aberrant expression of microRNAs contributes to the initiation and progression of numerous human cancers. The underlying effects and molecular mechanisms of microRNA-187 (miR-187) in gastric cancer (GC) remain unclear. The present study reports that miR-187 was significantly overexpressed in GC tissues compared to that in non-tumor tissues and was associated with malignant clinical factors such as depth of invasion (P = 0.005), tumor size (P = 0.024), lymph node metastasis (P = 0.048), and TNM stage (P = 0.035). Additionally, miR-187 promoted tumor growth in vivo, and significantly increased migration, invasion, and proliferation, but inhibited apoptosis in GC cells. It was found that collapsin response mediator protein 1 (CRMP1), a tumor suppressor, was a direct downstream target of miR-187 in GC. Furthermore, CRMP1 silencing resulted in similar effects on cell proliferation, migration, and apoptosis as those of miR-187 overexpressing GC cells. Additionally, the effects of miR-187 inhibitor on cell migration and cell apoptosis were reversed by CRMP1 downregulation. In summary, miR-187 promotes tumor progression by regulating CRMP1 expression in GC and may thus be a potential prognostic marker and a therapeutic target in GC.