Astragalus polysaccharide enhanced antitumor effects of Apatinib in gastric cancer AGS cells by inhibiting AKT signalling pathway

Apatinib has been proved effective in the treatment of advanced gastric cancer. Traditional Chinese medicine is often considered as adjuvants which could increase the effects and counteract the side effects of chemotherapy. The present study aims to explore the antitumor effects of Astragalus polysaccharide (AsPs) in combination with Apatinib in gastric cancer AGS cells. Our results demonstrated that the expression of VEGFR-2 was observed in human gastric cancer line AGS. Both Apatinib and AsPs could significantly inhibit the proliferation of AGS cells in a dose-dependent manner and Apatinib in combination with AsPs showed enhanced inhibitory effects on cell proliferation, migration and invasion compared with Apatinib monotherapy. Moreover, there was a remarkable increase in apoptosis following Apatinib treatment which could be enhanced by the addition of AsPs. Western blotting showed that the combination of Apatinib and AsPs could inhibit the expression of phosphorylated AKT (p-AKT) and MMP-9 expression. In addition, both Apatinib alone and Apatinib in combination with AsPs induced celluar autophagy which could be attenuated by the autophagy inhibitor 3-MA. The suppression of autophagy leaded to further apoptosis induction and cell proliferation suppression. In conclusion, the current study showed AsPs enhanced antitumor effects of Apatinib on AGS cells by the mechanism which includes inhibition of AKT signaling pathway. Apatinib-induced autophagy could be attenuated by 3-MA, which subsequently increased the apoptosis rate. On the basis of our study, the combination of Apatinib and AsPs could be considered as a potential candidate in the gastric cancer treatment.