miR-1285 Restrains Gastric Cancer Cell Growth and Causes Apoptosis by Negatively Regulating RAB1A.

MicroRNAs (miRNAs) act as critical biological factors in gastric cancer (GC). miR-1285 has been ascertained as a crucial antioncogene in some cancers. However, the effect of miR-1285 in GC and the regulatory mechanism are not clear. In this study, we revealed that miR-1285 expression was significantly reduced in GC. Overexpressing miR-1285 restrained GC cell multiplication and accelerated apoptosis, whereas suppressing miR-1285 facilitated cell growth and restrained apoptosis. The level of miR-1285 was negatively related to the RAB1A level in GC tissue specimens. RAB1A was verified by reporter gene assay as a target of miR-1285. Overexpression of miR-1285 suppressed the RAB1A level, whereas suppression of miR-1285 promoted the level of RAB1A expression. Knockdown of RAB1A resulted in analogical biological effect as that caused by overexpressing miR-1285. Moreover, both miR-1285 overexpression and RAB1A knockdown led to suppression of the mTOR/S6K1 pathway. By contrast, inhibition of miR-1285 promoted the mTOR/S6K1 pathway. In addition, miR-1285 also regulated the Bcl-2/Bax pathway. Taken together, our data indicate that miR-1285 suppresses GC cell multiplication by restraining the mTOR/S6K1 pathway and induces cell apoptosis by regulating the Bcl-2/Bax pathway via modulating RAB1A.