Abstract: ObjectiveTo explore the role of transforming growth factor-beta(TGF-β)signaling pathway in regulation of Gli in leukemia KG-1 cell line.MethodsKG-1 cells were treated with 0.1 ng/ml,1 ng/ml,and 10 ng/ml TGF-β1 for 6 hr,12 hr and 24 hr,respectively.The cells were collected after stimulation.Total mRNA was extracted.Gli 2 expression was detected.KG-1 cells were treated with 5 ng/ml TGF-β1 and 5 ng/ml TGF-β1+5 mol/L specific inhibitor of Smad 3 (SIS3),respectively,for 24 hr.The cells were collected after stimulation and total proteins were extracted.Gli 2 expression was detected.ResultsAfter the treatments of 1,10 ng/ml TGF-β1 to the KG-1 cells for 6 hr,12 hr,and 24 hr,Gli 2 mRNA expression decreased significantly(0.78,0.51,0.16 and 0.73,0.59,0.15,respectively)compared with those of the control group(P<0.05 for all).The Gli 2 expression(protein level)of control group was higher than that of the TGF-β treatment group,while much lower than that of TGF-β+SIS3 treatment group.ConclusionThe expression of Gli 2 in KG-1 cells induced by TGF-β is mediated through Smad 3 and the effect is independent of the Ptch/Smo axis.