高三尖杉酯碱诱导K562和CML细胞凋亡及分化的实验研究

目的 明确三尖杉酯碱（HHT）治疗慢性粒细胞性白血病（CML）的机理。方法 应用细胞长曲线、克隆形成能力、细胞内血红蛋白含量测定、细胞形态，结合DNA凝胶电泳、流式细胞仪等方法，观察HHT对K562细胞株及CML慢性期细胞的作用方式。进一步用RT－PCR方法研究bcr-abl、c-myc 、max基因在转录水平的改变。结果 低浓度HHT抑制K562细胞的克隆形成能力并使K562细胞内血红蛋白含量增加；0.1umol /L 及以上浓度HHT可诱导K562细胞及CML细胞凋亡；细胞周期分析发现细胞阻滞于G1期。c-myc基因在加药24h开始下凋； bcr-abl和max基基的表达未见明显改变。结论 低浓度HHT可抑制K562 细胞增殖并诱导其向红系分化；超过一定“ 阈浓度”HHT可诱导K562细胞和CML慢性期细胞凋亡；HHT可通过抑制c-myc/max 表达来阻 滞细胞周期。

Experimental study apoptosis and differentiation on K562 And CML cell induced by homoharringtonine

Objective To elucidate the effects induced by homoharringtonine(HHT) on chronic myelogenous leukemia (CML) cells. Method Using cell growth curve, cloning ability, intracellular hemoglobin content determination, cell morphology, DNA gel electrophoresis and flow cytometry, we explored the patterns of HHT acting on K562 cell line and fresh CML cells. Then RT-PCR was used to detect the changes of expression of bcr-abl, c-myc and max genes. Results Low concentration of HHT inhibited the cloning ability of K562 and increased the content of intracellular hemoglobin within K562 cells; 0.1～5.0μmol/L HHT could induce apoptosis of K562 cells and 6 cases of CML cells; Cell cycle analysis showed that cells were blocked at G1 phase; C-myc gene was down-regulated at 24h after HHT treatment, while there were no changes in bcr-abl and max gene. Conclusion Low concentration HHT may inhibit proliferation of K562 and induce differentiation into erythroid lineage; Apoptosis was detected in K562 cells and CML cells when the concentration of HHT reached a certain threshold; HHT may block the cell cycle by downregulatlng the c-myc/max expression. (Shanghai Med J, 2001,24:166)