ABSTRACT
Constitutive activation of nuclear transcription factor-κB (NF-κB) exists in a variety of leukemia, and induction of apoptosis through blocking NF-κB activation may be an alternative strategy for leukemia treatment. The aim of this study was to investigate the inducing effect of modified adenovirus 5-based adenovirus vector (i.e. chimeric Ad5F35 Vec)-mediated expression of mutant IκBα (IκBαDN) on apoptosis of HL-60 cells. The recombinant Ad5F35-IκBαDN Vec carrying IκBαDN cDNA which deleted the first 1-70 amino acids coding sequences at 5' terminal of human IκBα was transfected into HL-60 cells. The apoptosis, NF-κB DNA binding activity, the expressions of IκBα, cIAP-2 and xIAP in HL-60 cells were detected by DNA binding assay, flow cytometry, real-time quantitative polymerase chain reaction and Western blot respectively. The results showed that apoptosis rates were 22.53 ± 2.999%, 6.08 ± 2.464% and 4.86 ± 1.366% for Ad5F35-IκBαDN Vec-infected or blank vector of Ad5F35-EGFP Vec-transfected and untransfected HL-60 cells respectively, which showed a significant difference between Ad5F35-IκBαDN Vec-transfected and untransfected cells (p < 0.001) and between Ad5F35-IκBαDN Vec-transfected and Ad5F35-EGFP Vec-transfected cells (p < 0.001, p < 0.002), while NF-κB DNA binding activity was decreased, the truncated IκBα was expressed, and IκBα mRNA expression was up-regulated, but the expression of cIAP-2 and xIAP mRNA was down-regulated after transduction for 48 hours. It is concluded that the chimeric Ad5F35 Vec can effectively mediate the expression of IκBαDN cDNA in HL-60 cells, leading to the inhibition of NF-κB DNA binding activity and inducing apoptosis of HL-60 cells.