miR-194 targets RBX1 gene to modulate proliferation and migration of gastric cancer cells.

RING box protein1 (RBX1), an essential component of SCF E3 ubiquitin ligases, plays an important role in gastric cancer. In the study, miR-194 and RBX1 expression was evaluated in 76 pairs of gastric tumor and non-tumor tissue samples by qRT-PCR, and clinicopathological characteristics were analyzed. CCK8, transwell assay, wound healing assay, and flow cytometry assay were performed to evaluate the effect of miR-194 on gastric cancer (GC) cellular proliferation, invasion, migration, apoptosis, and cell cycle, respectively. Luciferase reporter assays and Western blotting were used to evaluate whether RBX1 is a direct target of miR-194. The Kaplan-Meier method and log-rank test were used to evaluate the correlation between miR-194 or RBX1 expression and patient survival. Then, we found that miR-194 was significantly downregulated and RBX1 upregulated in GC tissues; both of which showed significant association with tumor size, location, invasion, and tumor node metastasis. Cell proliferation, invasion, and migration were significantly restricted with miR-194 overexpression. miR-194 downregulated RBX1 protein expression, and luciferase assays showed that binding sites in the RBX1 3'UTR were required for miR-194-mediated repression of RBX1, indicating that RBX1 was a direct target of miR-194. Transfection of RBX1 without the 3'UTR restored the miR-194-inhibiting migration function. miR-194 overexpression or RBX1 lowexpression was associated with prolonged survival of GC patients. In conclusion, upregulation of miR-194 can inhibit proliferation, migration, and invasion of GC cells, possibly by targeting RBX1. Aberrant expression of miR-194 and RBX1 is correlated to GC patient survival time.