Effect of Down-Regulatory Nucleostemin Expression on Autophagy Activities in p53 Null HL-60 Leukemia Cells

Abstract

Based on previous microarry and bioinformatic analysis results, to investigate the effect of nucleostemin(NS) expression down-regulation on autophagy activity in p53 null HL-60 leukemia cells, so as to provide evidence for studying mechanisms of p53-independent signal pathway of NS in details. The autophagy activity of HL-60 cells after down-regulation of NS expression was detected with acidine orange staining, Western blot and transmission electron mcrioscope technique. The expression level of NS in test groups was lower than that in blank control and negative control groups after HL-60 cells were readily transinfected by lentivirus. The result of acidine orange staining showed that the number of acid vesicular organelle in test groups(22.4±0.76)% was higher than that in blank control groups(3.1±0.28)% and negative control groups(6.2±0.64)% (P<0.05). Western blot showed that the ratio of LC3II/LC3I in test groups(1.537±0.072) was higher than that in blank control and negative control groups (1.010±0.039) and (0.608±0.008). The result of transmission electron mcrioscopy also showed that the number of autophagosomes in test group(8.7±3.1) was higher than that in the blank control and negative control groups(4.2±1.2) and (2.3±0.5). Autophagy activty can be enhanced after the level of NS was down regulated. The change indicates the signaling transductions screened by bioinformatic analysis may be one of p53-independent pathway of NS, which lays a foundation for contineously studying key points of p53-independent signal pathway of NS.