MicroRNA-134 functions as a tumor suppressor gene in gastric cancer.

MiR-134 can function as an oncogene or a tumor suppressor gene depending on cell type. However, the function of miR-134 in gastric cancer remains unclear to date. This study aims to evaluate the function of miR-134 in gastric cancer and investigate its effect on the sensitivity of gastric cancer cells to 5-FU. The expression of miR-134 assayed by real-time PCR was significantly lower in gastric cancer tissues than in noncancerous tissues. Over-expression of miR-134 significantly inhibited the proliferation and growth in vivo, as well as promoted the apoptosis of gastric cancer cells by targeting KRAS. Finally, the up-regulation of miR-134 enhanced the sensitivity of gastric cancer cells to 5-FU. In conclusion, miR-134 suppresses tumor development in gastric cancer by targeting KRAS and enhances cell sensitivity to 5-FU. Our results encourage researchers to use 5-FU in combination with miR-134 to treat gastric cancer.