MicroRNA-124 inhibits cell invasion and epithelial-mesenchymal transition by directly repressing Snail2 in gastric cancer.

OBJECTIVE

MicroRNAs (miRNAs) act as critical regulators of genes expression involved in tumor biological processes. The study aimed to investigate the clinical significance and biological role of miR-124 in gastric cancer (GC).

PATIENTS AND METHODS

MiR-124 expression was analyzed from 88 GC tissues and adjacent normal tissues by quantitative Real-time PCR (qRT-PCR). Kaplan-Meier curves and log-rank test was used to evaluate the association between miR-124 and the over survival (OS) time of GC patients. MTT assays and transwell invasion assays were performed to assess cell proliferation and invasion. The relationship between miR-124 and Snail2 expression was analyzed by dual luciferase reporter assay. Western blot analyses were performed to detect the relative protein expression.

RESULTS

We found that miR-124 expression was significantly reduced in GC tissue samples when compared to the adjacent normal tissues (p<0.05). Lower miR-124 was found to be associated with tumor size (p=0.001), lymphatic metastasis (p=0.008) and TNM stage (p=0.015). Furthermore, patients who have lower miR-124 predicted poor OS time (p<0.05). Function studies suggested that cell proliferation and invasion ability of GC cells were inhibited by up-regulation of miR-124 expression. Moreover, we demonstrated that Snail2 was a direct target of miR-124. Meanwhile, miR-124 inhibited Epithelial-Mesenchymal Transition (EMT) process by repressing the Snail2 expression in GC cells.

CONCLUSIONS

MiR-124 acted as a tumor suppressor in GC and may be a useful target for GC treatment.