Roles of ASPP2 in the apoptosis, cell cycle and autophagy of starvation-induced HCT116 p53 +/+ cell line / 国际肿瘤学杂志

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(1) control group; (2) green fluorescent protein adenovirus (rAd-GFP) infection group; (3)ASPP2 adenovirus (rAd-ASPP2) infection group; (4)starvation group; (5)rAd-GFP + starvation group; (6) rAd-ASPP2 + 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 and autophagy.The cell apoptosis rate in rAd-GFP + starvation group was 10.00％ ± 1.42％,and 18.44％ ±2.06％ in rAd-ASPP2 + starvation group(q =9.548,P =0.000).The cell autophagy rate in rAd-GFP+ starvation group and rAd-ASPP2 + starvation group was 35.00％ ± 5.34％ and 57.61％ ± 6.06％ respectively(q =7.657,P =0.000).Over-expressed ASPP2 accelerated HCT116 G2/M arrest under starvation,but resulted in both G0/G1 and G2/M arrest without starvation.Conclusion These results suggest that ASPP2 can promote starvation-induced HCT116 p53 +/+ cells apoptosis and autophagy,and affect the cell cycle.