Effect of adenovirus-mediated p27 gene expression on the proliferation and apoptosis of HL-60 and Raji cell lines

Abstract

To explore the possible effect of p27 gene expression on the proliferation and apoptosis of HL-60 and Raji cell lines. The infections of HL-60 and Raji cells were performed by the adenovirus-mediated p27 gene transfection approach. The efficiency of Adp27 infection and the expression of p27 mRNA and protein were evaluated by X-gal staining, RT-PCR and flow cytometry. The proliferation and apoptosis of HL-60 and Raji cells were estimated by using trypan blue staining, MTT assay, Annexin V/PI and DNA ladder electrophoresis. The infection efficiency of HL-60 and Raji cells were 40.3 and 32%, respectively; RT-PCR and flow cytometry showed that there were significant expressions of p27 mRNA and protein of HL-60 and Raji cells infected by Adp27, while HL-60 cells themselves showed only faint p27 mRNA and protein, and Raji cells hardly presented p27 mRNA and protein. The strong proliferation inhibitions, which were in a time-dependent manner for HL-60 and Raji cells infected by Adp27, were indicated by cell growth curve and MTT assay. After 72 h infection of HL-60 and Raji cells by Adp27, the Annexin V+/PI- apoptotic cell rates were 46.9 and 35.7% respectively, which were significantly increased compared with control group (4.7 and 5.6% respectively). The typical DNA ladder bands were detectable in HL-60 and Raji cells after 48 h of Adp27 infection. The infection of HL-60 and Raji cells by means of adenoviral vector-mediated p27 gene could evidently inhibit cellular proliferation and promote cell apoptosis, which would provide experimental evidence for gene therapy of leukemia/lymphoma using adenovirus-mediated p27 gene approach.