| Abstract |
AN30 is extracted from stem and leaves of Thelypteris torresiana. Recently, select killing cancer cells through apoptosis and other mechanisms are proved to increase the efficacy of chemotherapy. Our previous studies indicate that AN30 can select kill oral cancer cells, however the mechanism is unclear. Autophagy is associated with chemotherapy drug. We found AN30 can induce apoptosis and autophagy. When oral cancer was pretreated with starvation, the AN30 cell toxicity is significantly reduced (cell survival rate of Ca9-22, from 64% in 1.5 µg/ml AN30 to 139% in starvation pretreatmen). Then we use autophagy maker acridine orange staining, LC3 in western blot analysis, and autophagy inhibitor chloroquine to investigate the relation of starvation, cell toxicity and autophagy. Our experimental results show the starvation induce autophagy, then suppress AN30 cell toxicity (24 hr cell survival rate of Ca9-22, from 64% in 1.5 µg/ml AN30 to 139% in starvation pretreatment), with high AO fluorescence expression in oral cancer cells, though the LC3-II level . But co-treat AN30 and autophagy inhibitor chloroquine cannot inhibit the starvation induced AN30 resistance in oral cancer cells (24 hr cell survival rate of Ca9-22, from 34% in 1.5 µg/ml AN30 and 12.5 CQ, to 61% in starvation pretreatment compared to 65% without CQ co-treatment). Previous studies indicate that AN30 can increase cellular ROS levels. Our future work will focus on the mechanism of starvation induced drug resistance which may associate with autophagy and ROS scavenge. |
|---|
