Synergistic Inhibitory Effect Of Smo Inhibitor Combined With Decitabine On MUTZ-1 Cells

Objective: To study the effects of Smo inhibitor in Shh signal pathway combined with Decitabine on proliferation,apoptosis and cell cycle of myelodysplastic syndromes MUTZ-1 cell line,and to explore the possible molecular mechanism.Methods: MUTZ-1 cell line was cultured in vitro.The cell proliferation rate was detected by CCK-8 method.The apoptosis and cell cycle changes were detected by Annexin V-FITC/PI double staining flow cytometry.The expression of Smo and Gli-1 m RNA was detected by real-time quantitative PCR.The expression of Smo,Gli-l,PI3 K,p-AKT,Bcl-2,Caspase-3 and Cyclin Dl was detected by Western blot.Results: Smo inhibitor Jervine or Decitabine alone could inhibit the proliferation of MUTZ-1 cells in a time-dependent and concentrationdependent manner.The combined intervention of the two drugs could significantly inhibit cell proliferation,induce apoptosis,and increase the proportion of cells in G1 phase and decrease the proportion of cells in S phase of cell cycle,indicating that Jervine can block the cell cycle of MUTZ-1 in G1/S phase.The results of q RT-PCR detection showed that the expression levels of Smo and G1i-1 m RNA in MUTZ-1 cells decreased significantly after the combined intervention of the two drugs.The results of Western blot assay showed that the expression levels of Smo,G1i-1,PI3 K,p-AKT,Bcl-2 and Cyclin Dl protein in MUTZ-1 cells were significantly down-regulated,after the combined intervention of the two drugs,while the expression level of Caspase-3 protein was on the contrary.Conclusion: Smo inhibitor combined with Decitabine has a synergistic effect on the proliferation and apoptosis of MUTZ-1 cells.The mechanism may be realized by interfering with Shh signal pathway to regulate PI3K/AKT signal axis and mediates the change of downstream protein expression.