Inhibition of TGF-1 on Gli2 expression was promoted by TNF- in primary leukemia cells

Purpose Hedgehog (Hh) signaling pathway regulates a variety of tumors-related diseases including leukemia. Whether inhibition of TGF-beta 1 on Gli2 expression is promoted by TNF-alpha in primary leukemia cells remains to be determined. Methods Primary leukemia cells were treated with TGF-beta 1, TNF-alpha or SIS3 at different concentrations. Gli2 expression was detected by quantitative real-time PCR and western blot analyses. Results We found that TGF-beta significantly decreased Gli2 expression, and co-treatment with TNF-alpha further decreased Gli2 expression in primary leukemia cells. TNF-alpha can increased TGF-beta RI and TGF-beta RII protein expression in primary leukemia cells, while SIS3 inhibited the effect of TGF-beta. Conclusion Our results suggest that Gli2 expression in primary leukemia cells is induced by TGF-beta in a Smad3-dependent manner, and independent of Hh receptor signaling.