Abstract:Objective To investigate the role of apoptosis stimulating protein 2 of p53（ASPP2）in the apoptosis, cell cycle and autophagy of starvation-induced colorectal cancer HCT116 p53^+/+(p53 wild-type) cell line. Methods Six groups were included: ⑴ control group; ⑵ green fluorescent protein adenovirus (rAd-GFP) infection group; ⑶ ASPP2 adenovirus (rAd-ASPP2) infection group; ⑷ starvation group; ⑸GFP+ starvation group; ⑹ASPP2+ starvation group. HCT116 cells were infected with ASPP2 adenovirus (rAd-ASPP2), resulting ASPP2 gene over-expression. The apoptosis, autophagy and cell cycle changes were induced by culturing with serum-free medium for 24 h. Apoptosis was evaluated by Calcein／PI uptaking test, and autophagy was observed by counting the red fluorescent protein autophagy plasmid CFP-Lc3 which was transfected into cytoplasm. Cell cycle was detected by flow cytometry. Statistical analysis was performed by one-way analysis of variance (ANOVA). Results Over-expressed ASPP2 was found to significantly promote starvation-induced HCT116 apoptosis（cell apoptosis rate: GFP+ starvation group : 10.00%±1.42%；ASPP2+ starvation group: 18.44%±2.06% P=0.000） and autophagy（cell autophagy rate: GFP+ starvation group : 35.00%±5.34%；ASPP2+ starvation group : 57.61%±6.06% P=0.000）, and accelerate HCT116 G₂/M arrest under starvation. But over-expressed ASPP2 could result in both G₀/G₁and G₂/M arrest without starvation. Conclusion These results suggest that ASPP2 can promote HCT116 p53^+/+cell apoptosis and autophagy, and affect the cell cycle.

Key words:Apoptosis,Cell cycle,Autophagy,Apoptosis stimulating protein 2 of p53