Abstract: Objective To investigate the effect of PML (NLS-) on proliferation and apoptosis of leukemic NB4 cells by the over-expression of PML(NLS-) induced by adenoviruses. Methods Recombinant adenovirus plasmid Ad-PML (NLS-) was digested and linearized with Pac I enzyme then transfected into AD293 cells. After amplified the Recombinant adenovirus Ad-PML(NLS-) for four times, to test recombinant adenovirus titer. After Recombinant adenovirus transfected into NB4 cells, infection efficiency was detected by fluorescence microscopy imaging and flow cytometry, the transcription and expression level of PML(NLS-) in NB4 cells were detected by RT-PCR and Western blot. Cell proliferation was detected by MTT. Cell cycle and apoptosis was detected by flow cytometry. Results Recombinant adenovirus plasmid Ad-PML (NLS-) was exactly digested and sequenced. The titer of amplified virus was . The efficiency of transfection was 75%, and PML(NLS-) had a high level expression in NB4 cells. The activity of cell proliferation in NB4 cells was significant enhanced compared with the untransfected and empty viral vector (p<0.05). The proportion of cells in S phase was obviously increased while which was obviously decreased in G1 phase. The rate of apoptosis in the experimental group was obviously lower than the empty viral vector. Conclusions The over-expression of PML(NLS-) could promote the proliferation of NB4 cells in vitro and inhibit the apoptosis.

Key words: PML(NLS-), acute promyelocytic leukemia, proliferation, apoptosis