STI571诱导慢性髓系白血病K562细胞凋亡信号通路的研究

Signal Pathway in Apoptosis of K562 Cells Induced by STI571

本研究应用基因芯片探讨酪氨酸激酶抑制剂(STI571)对K562细胞生长、增殖的影响,研究STI571诱导细胞凋亡过程中基因表达的变化及STI571诱导K562细胞凋亡的机制。用RD-PCR技术制备基因芯片探针,然后制成K562细胞表达谱芯片;用相差显微镜观察K562细胞在STI571处理前后的形态变化;用MTT法检测K562细胞的凋亡,用制备的K562细胞表达谱芯片分析基因表达水平。结果表明,在体外培养条件下用1.0μmol/L的STI571处理K562细胞达到一定时间(24小时)后,K562细胞生长明显变缓,出现凋亡细胞的特征。用自制的K562细胞基因表达谱芯片检测显示,STI571诱导K562细胞凋亡前后的基因表达有差异。杂交检测后发现,经STI571诱导后基因表达下调的基因有9个,表达上调的基因有4个。这些表达变化的基因主要包括细胞周期相关基因、细胞代谢通路相关基因、信号转导和转录调节相关基因及抗凋亡基因。结论:STI571能有效抑制K562细胞生长,诱导K562细胞凋亡;筛选获得的靶基因在K562细胞恶性转化过程中发挥了重要作用,这为药物靶基因的筛选提供了理论基础。

This study was aimed to investigate the effect of tyrosine kinase inhibitor （ STI571 ） on growth and proliferation of K562 cells by using microarray method, the changes of gene expression in the process of K562 cell apoptosis induced by STI571 and the mechenism of K562 cell apoptosis. The gene microarray probes were prepared by RD-PCR technique, then the microarray of gene expression map was constructed; the morphologic changes of K562 cells were observed under phase-contrast microscopy before and after treatment with STI571 ; the apoptosis of K562 cells treated with STI571 was assayed by MTT method; the expression level of genes was analyzed by self-made microarray. The results indicated that after the treatment of STI571 for 24 hours, in K562 cells appeared major morphological changes, which ineluded nuclear shrinkage, membrane bleb and scattered apoptotic bodies. DNA gel electrophoresis also showed that the typical ＂DNA ladder＂ phenomena existed in the treated group. After hybridization, detection and analysis with microarray method, expression of 9 genes significantly down-regulated and expression of 4 genes up-regulated. These differentially expressed genes included cell cycle related genes, cell metabolizing pathway related genes, signal transduction and transcription regulation related genes and antiapoptosis genes. It is concluded that STI571 can effectively inhibit the K562 cell growth and induce K562 cell apoptosis. The genes screened from this microarray offer new information for exploration of pathogenesis of K562 cell malignant transformation and shows abundant potential targets for the treatment of CML.