Abstract: Objective:To explore the regulation of human telomerase reverse transcriptase(hTERT) expression in HL-60 cell by Sp1.Methods:The Sp1 binding sites of hTERT promoter sequence(-116--88 bp) were assayed by electrophoretic mobility shift assay(EMSA).The hTERT mRNA expressions of HL-60 cells treated with different concentration of mithramycin were examined by RT-PCR.Results:The binding bands of DNA-protein were detected by autoradiography when nuclear protein interacted with hTERT promoter sequence.Mithramycin inhibited the binding of Sp1 and the sequences,and decreased the mRNA expression of hTERT with concentration dependent manner,and which of mithramycin of 200 nmol/L group and 100 nmol/L group were significantly lower than those of 50 nmol/L group,25 nmol/L group and the control group(P0.01).Conclusions:Sp1 can bind the promoter sequence(-116--88 bp),which can upregulate the mRNA expression of hTERT.