Effects Of Dll4on Cell Growth And The Expression Of Protein Rb In Leukemia Cell Line K562

Objective: To explore the effects of gene Dll4on cell growth and the expression ofprotein Rb in leukemia cell line K562, and then to observe the specific mechanisms ofproliferation inhibition in K562cells effected by ligand Dll4of Notch.Methods: pBudCE4.1-Dll4plasmid was transfected into K562leukemia cells by thelipofectamine2000-coated DNA. As control plasmids, pBudCE4.1plasmid was alsotransfected. The pathogenic effect of the Dll4vector transfected cell culture wasquantified as follow:①48hours after transfection, the cells were collected with RIPAcell lysis buffer, the protein expression level of exogenous Dll4and Rb in each groupcells was detected by Western Blot；②48-hours after transfection, the Cell CountingKit-8was used to detect growth of K562cells, and the activity of caspase3andcaspase8was detected by eolorimetric assay.Results:48hours after transfected by Lipofectamine2000, Dll4and Rb proteinexpression could be detected by Western Blotting in K562cells. The results weresemi-quantitatived with Quantity0ne software and analyzed with SPSS statisticalsoftware. Expression of Dll4was detected in pBudCE4.1-Dll4transfected cells, andthe levels of Dll4and Rb protein in experimental group cells were significantly higherthan that in control groups. Cell growth of K562cells transfected withpBudCE4.1-Dll4plasmid was significantly inhibited compared with cells transfectedwith pBudCE4.1plasmid. The activity of caspase3and caspase8in the experimentalgroup was higher than that in two control groups (p<0.05).Conclusion: Expression of Dll4and Rb protein was increased in leukemia cellstransfected by recombinant plasmid pBudCE4.1-Dll4,which may inhibit the growthof K562cells and May induce cell cycle apoptosis.