Abstract
MicroRNAs (miRNAs) are small, evolutionarily conserved, non-coding RNAs playing a role in the proliferation, metastasis, apoptosis, chemo-sensitivity, and chemo-resistance of gastric cancer, as well as the stemness of gastric cancer stem cells. miR-708-3p induces gastric cancer cell chemo-resistance, but its actual role in gastric cancer progression remains unclear. This paper shows that miR-708-3p is upregulated in gastric cancer samples and that a high miR-708-3p expression in gastric cancer patients is associated with poor overall survival. Our functional study results indicate that miR-708-3p overexpression promotes gastric cancer cell proliferation and migration, inhibits cell apoptosis, and facilitates the transition from the G0/G1 to the G2/M phase. Furthermore, reducing miR-708-3p levels yielded opposite effects. Next, our in vivo experiments revealed that miR-708-3p advanced gastric cancer cell growth in nude mice. The underlying mechanism was the regulation of ethanolamine kinase 1 (ETNK1) expression by miR-708-3p, which bound to the 3'UTR of the ETNK1 gene in gastric cancer cells. Finally, the recovery assay results showed that ETNK1 overexpression could slow miR-708-3p-induced gastric cancer progression. In conclusion, we identified a new miR-708-3p/ETNK1 pathway involved in gastric cancer progression. These results may offer new targets for gastric cancer therapy and markers for gastric cancer prognosis.