Autophagy Protects from Raddeanin A-Induced Apoptosis in SGC-7901 Human Gastric Cancer Cells

Figure 1

(a) Effects of RA on cell inhibition. Cells were treated with different concentrations of RA for 12 h. The bars indicate standard errors. The asterisk indicates a significant increase in the inhibition rate between groups treated with RA or not. Data are expressed as mean ± SD of three experiments (). (b) Effects of RA on cell apoptosis. SGC-7901 cells were treated with different concentrations of RA for 12 h and harvested by trypsinization and centrifugation and then analyzed by FCM after staining with Annexin V-FITC and PI. Results shown are of an experiment representative of apoptosis. Q1-UL showed that cells were undergoing necrosis, and Q1-UR showed that cells were at the end stage of apoptosis. Q1-LL showed that cells were viable or there was no measurable apoptosis. Q1-LR showed that cells were undergoing apoptosis. (c) The morphologic change was assessed by fluorescence microscopy. Cells were fixed with 4% paraformaldehyde for 30 min after being treated with different concentrations of RA for 12 h at room temperature and washed once with PBS. Hoechst 33258 (50 ng/mL) was incubated for 30 min and then washed with PBS. Apoptotic cells were identified by the condensation and fragmentation of their nuclei and photographed by a Zeiss Axioplan 2 fluorescence microscope (400x). (d) The levels of apoptosis related proteins were tested by western blotting analysis. After cells were treated with 0, 4, 8, and 16 μM of RA for 12 h, the protein levels of Bcl-XL, Bcl-2, BAX, cleaved-caspase-3, and cleaved-PARP were determined by western blotting.

(a)

(b)

(c)

(d)