Dysregulation of Rab11a has been implicated in the progression of several
cancers. However, there have been no such studies for human
gastric cancers. In the current study, we examined
Rab11a protein expression and found it was upregulated in 49 of 108
gastric cancer tissues and correlated with local invasion, nodal
metastasis, and advanced stage.
Rab11a protein was higher in
gastric cancer cell lines than normal gastric cell line. We transfected Rab11a plasmid and
siRNA in both MGC803 and AGS cell lines. Rab11a overexpression increased the cell growth rate, colony numbers, and invasion ability in both MGC803 and AGS cell lines. Downregulation of Rab11a using
siRNA decreased the cell proliferation rate, colony numbers, and inhibited invasion. Rab11a overexpression also conferred
cisplatin resistance.
Annexin V/PI staining showed that Rab11a overexpression suppressed
cisplatin-induced apoptosis, while Rab11a depletion promoted cell apoptosis. We also showed that Rab11a overexpression maintained mitochondrial membrane potential. Western blot analysis revealed that Rab11a increased
protein expression of MMP2,
cyclin D1, Bcl-2, p-FAK, and p-AKT, while Rab11a depletion showed the opposite effects. Blockage of FAK using inhibitor downregulated Bcl-2,
cyclin D1, MMP2, and p-AKT expression and abolished the effects of Rab11a on these
proteins. In summary, our data demonstrated that Rab11a is upregulated in human
gastric cancers. Rab11a facilitated cell proliferation and invasion, as well as
cisplatin sensitivity and mitochondrial membrane potential, possibly via the FAK/AKT signaling pathway.