The effect of recombinant human TNF-α apoptosis and bcl-2 gene expression of HL-60 cell line

Objectives The aim of this study was to investigate the effects and mechanisms of TNF-α on leukemic blasts and to search for the principle of the leukemic immunotherapy.Methods HL-60 cells were incubated with recombinant human TNF-α(rh-TNF-α). The number of bcl-2 protein expression positive cells was detected by immunocytochemistry and cell apoptosis by hematoxylin dye.Results Incubated with 10 U/ml?100 U/ml and 500 U/ml rhTNF-α, the number of apoptosis HL-60 cells was significantly higher than those of control groups (P0.05) accompanied by decreasing of bcl-2 expression positive HL-60 cells (P0.05) except the group in which HL-60 cells were incubated with 10 U/ml rhTNF-α for 2hr(P0.05). The higher the dose of rhTNF-α, the larger the effect. And the effect reached it′s apex at 8hr. The numbers of apoptosis HL-60 cells had a negative correlation with bcl-2 expression.Conclusions TNF-α can promote the apoptosis of HL-60 cells. Down-regulation of bcl-2 gene expression may be one of the mechanisms of TNF-α′s apoptosis-promoting effect.