Rab5a suppresses autophagy to promote drug resistance in cancer cells.

Cancers are huge problems that need to be investigated thoroughly. Rab5a plays an important part in the regulation of intracellular membrane trafficking. However, its role in cancer and autophagy has not been fully determined. In this study, we analyzed the correlation between Rab5a expression and patients' prognosis and then explored the effect of Rab5a knockdown on different cell lines using western blotting and fluorescence. Our results showed that up-regulated Rab5a positively correlated with the prognosis of gastric cancer patients. After knocking down Rab5a, mTOR activity was inhibited and autophagy flux increased. We also found that in our cisplatin-resistant cells, knockdown of Rab5a activated autophagy via mTOR pathway and could reverse drug resistance while overexpression of Rab5a in drug sensitive cells increased drug tolerance. In conclusion, our study demonstrates that Rab5a can suppress autophagy through mTOR and promote drug resistance in gastric cancer cells.