Abstract: Objective To construct RGD-modified leukemia inhibitory factor（LIF） and interleukin-24（IL-24） gene co-expression adenovirus vector， and detect the inhibition effect for human leukemia MEG01 cells from LIF and IL-24.
MethodsThe RGD-modified adenovirus Ad.RGD-LIF， Ad.RGD-IL24 and Ad.RGD-LIF-IL24 were construct by using the method of homologous recombination. The adenovirus in QBI-293A cells were amplified， then the titer of adenovirus were detected. The infection efficiency of MEG01 leukemia cells were detected by flow cytometry. After infecting Ad.RGD-LIF， Ad.RGD-IL24 and Ad.RGD-LIF-IL24 adenovirus 48 hours， the expressions of LIF and IL24 in MEG01 cells were detected by Western blotting method. The CCK-8 and PE-AnexinV／7-AAD method were used to detect the growth inhibition and apoptosis of MEG01 cells. Then p53， Bax and Bcl-xl gene expressions in MEG01 cells infected with adenovirus were detected by Western blotting method. PI staining method was used to detect the cell cycle of MEG01 cells. Realtime PCR method was used to detect p21 and E2F1 gene expressions.
ResultsThe RGD-modified adenovirus Ad.RGD-LIF， Ad.RGD-IL24 and Ad.RGD-LIF-IL24 were construct successfully. Compared with the Ad-GFP group， RGD-modified adenovirus could enhance the infection efficiency of MEG01 cells significantly. Exogenous gene LIF and IL-24 could inhibit the growth of MEG01 cells and induce cell apoptosis through the regulation of p53， Bax and Bcl-xl gene expression. Besides， the double gene expression has a synergistic effect. In MEG01 cells， LIF and IL-24 over-expression could induce cell cycle arrest. Furthermore, LIF and IL24 could upregulate the expression of cell cycle regulated gene p21 and inhibit the E2F1 expression. Conclusion LIF and IL-24 co-expression adenovirus can inhibit the MEG01 cell growth， induce cell apoptosis and cell cycle arrest, probably by regulating the expression of p53, Bax and Bcl-xl in vitro.