MicroRNA-17-5p promotes gastric cancer proliferation, migration and invasion by directly targeting early growth response 2

MicroRNA-17-5p (miR-17-5p) has previously been reported to play an important role in tumor development and progression. However, it functions differently regarding different kinds of malignant tumor, and its role and mechanism in gastric cancer (GC) still lacks investigation. In this study, we detected the relationship between miR17-5p and the development of GC by qRT-PCR, and it turned out that the level of miR-17-5p was significantly higher in GC patients than that in normal controls, and the aberrant expression of miR-17-5p was correlated with lymph node metastasis. After that, we examined the effect of miR-17-5p taking on the proliferation, apoptosis, migration and invasion of GC cells and the underlying mechanism. Experiments indicated that knockdown of miR-17-5p inhibited the proliferation, invasion and migration, while promoting apoptosis of SGC7901 cells. Early Growth Response 2 (EGR2) protein or mRNA levels were downregulated or upregulated after overexpression or knockdown of miR17- 5p, respectively. By using dual luciferase assay and Western blot, we identified EGR2 as a functional target of miR-17-5p. As far as we know, this could be the first study to demonstrate that miR-17-5p is associated with tumor stage of GC and that it could possibly become a new therapeutic method for the treatment of GC.