抑癌基因p16INK4a与p53抑制白血病细胞株生长作用的比较

 目的 比较野生型p16INK4a、p53抑癌基因的表达对白血病细胞株K562和HL60的生长抑制。方法 采用脂质体介导野生型p16INK4a、p53抑癌基因转染K562、HL60细胞并进行G418筛选，免疫印渍检测p16INK4a、p53基因的表达，通过细胞生长曲线检测细胞活力，流式细胞仪进行细胞DNA周期分析及细胞凋亡分析，采用联苯胺氧化试验检测K562细胞的分化。结果 转染后p53、p16INK4a在K562及HL60细胞中表达；与对照细胞相比，实验组细胞生长受到明显的抑制，G1期细胞数增加，S期细胞减少。与p16INK4a相比，抑癌基因p53使细胞表达Annexin V增加，显示出更强的致凋亡现象，尤其在HL60细胞株。结论 抑癌基因p16INK4a、p53能有效抑制白血病细胞株的生长，可能更适合复发、难治性白血病的基因治疗。

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 p16INK4a or p53 on growth and apoptosis in leukemic cells K562 and HL60. Methods The mammalian expression vectors containing p53, p16INK4a, or β-galac－tosidase cDNA were transfected into the K562 and HL60 cell lines , and the expression of the transfected genes was detected by Western-immunoblotting. The effect of the p16INK4a or p53 transfected cell culture was quanlified by trypan blue staining, and the number of recovered viable cells was assessed everyday after transfection. Cells were analyzed for expression of Annexin V for detection of apoptosis, and the cell cycle was analyzed by flow cytometry. Transfected K562 cells differentiation was measured by benzidine oxidation test. Results After transfection, p53 or p16INK4a gene expressed in transfected cells. When compared with control vector, p16INK4a or p53 eukaryotic expression vector significantly inhibited K562 or HL60 cells proliferation and increased the number of 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 transfected cells compared to p16INK4a transfected cells, especially in HL60 transfected cells. Conclusion Tumor suppressor gene p53 and p16INK4a, significantly inhibited K562 and HL60 cells proliferation, may be a viable future treatment for refractory leukemia.