Comparison of the effectiveness of eukaryotic expression vectors expressing tumor suppressor genes p16^INK4a and p53 in inhibiting leukemic cells proliferation

Objective To determine the effects of p16^INK4a or p53 on growth and apeptesis in leukemic cells K562 and HL60. Methods The mammalian expression vectors containing p53, p16^INK4a, or β-galaetosidase cDNA were transfected into the K562 and HL60 cell lines , and the expression of the transfeeted genes was detected by Western-immuneblotting. The effect of the p16^INK4a er p53 transfeeted cell culture was quanlified by trypan blue staining, and the number of recovered viable cells was assessed everyday after transfeetien. Cells were analyzed for expression of Annexin V for detection of apeptesis, and the cell cycle was analyzed by flow cytometry. Transfected K562 cells differentiation was measured by benzidine oxidation test. Results ＂After transfection, p53 er p16^INK4a gene expressed in transfeeted cells. When compared with control vector, p16^INK4a or p53 eukaryetie expression vector significantly inhibited K562 or HL60 cells proliferation and increased the number ef cells in G1 phase and decreased that in S phase. The percentage of cells expressing the apoptosis related cell surface antigen Annexin V was significantly higher in p53 transfeeted cells compared to p16^INK4a transfeeted cells, especially in HL60 transfected cells. Conclusion Tumor suppressor gone p53 and p16^INK4a, significantly inhibited K562 and HL60 cells proliferatien, may be a viable future treatment for refractory leukemia. Key words: Leukemia;  Gene, p16;  Gene, p53;  Transfection