细胞周期蛋白依赖激酶抑制剂诱导HL-60细胞凋亡及分子机制研究

目的:探讨细胞周期蛋白依赖激酶(CDK)抑制剂SNS-032诱导人急性髓系白血病HL-60细胞凋亡的效应及可能的机制。 方法:以CDK抑制剂SNS-032作用于HL-60细胞株,实验细胞分为对照组、SNS-032组、白细胞介素(IL)-6组和SNS-032+IL-6组。MTT法检测细胞存活率,流式细胞术检测细胞凋亡, microRNA芯片技术分析细胞microRNA的表达谱差异,蛋白质印迹法检测JAK/STAT3相关信号通路蛋白的表达。 结果:SNS-032可降低细胞存活率,诱导HL-60细胞凋亡,对照组、100nmol/L和200nmol/L的SNS-032干预组细胞凋亡率分别为(5.9±1.7)%、(12.1±3.1)%和(59.4±3.6)%。microRNA芯片分析结果显示,SNS-032显著下调HL-60细胞miR-30a、miR-183、miR-20b、miR-26b、miR-20a、miR-589、miR-107、miR-181a、miR-106a、miR-17和miR-378c的表达水平,显著上调miR-320a的表达水平。蛋白质印迹法显示SNS-032可抑制STAT3的磷酸化和JAK2、MCL-1、C-MYC蛋白的表达。作为JAK/STAT3通路的激活剂,IL-6联合SNS-032不能逆转后者对HL-60细胞的杀伤作用(P>0.05),也不能逆转SNS-032对JAK2蛋白表达和磷酸化STAT3的抑制作用。结论:SNS-032能显著诱导人急性髓系白血病 HL-60细胞发生凋亡,其机制可能与抑制JAK2和STAT3磷酸化、抑制MCL-1和C-MYC及与之相关的miR-17-92基因簇表达水平有关。
Abstract: Objective: To investigate the effects of cycle-dependent kinase (CDK) inhibitor SNS-032 on apoptosis in human acute myeloid leukemia (AML) HL-60 cells and its molecular mechanisms. Methods: Cultured AML HL-60 cells were treated with various concentrations of SNS-032. Cell apoptosis was determined with flow cytometry;cell viability was measured by MTT assay; the profiles of microRNA expression of HL-60 cells were analyzed by microRNA microarray;the protein expressions of JAK2/STAT3 pathway were detected by Western blotting. Results: Apoptosis of AML HL-60 cells was induced by SNS-032; the rate of apoptosis was (5.9±1.7)%, (12.1±3.1)% and (59.4±3.6)% when HL-60 cells were treated with 0,100 and 200 nmol/L SNS-032. MicroRNA microarray analysis revealed that the levels of miR-30a, miR-183, miR-20b, miR-26b, miR-20a, miR-589, miR-107, miR-181a, miR-106a, miR-17 and miR-378c were down-regulated by SNS-032,whereas the levels of miR-320a and miR-H7* were up-regulated. Western blotting showed that SNS-032 strongly inhibited phosphorylation of STAT3 and protein expression of JAK2,C-MYC and MCL-1. Conclusion: CDK inhibitor SNS-032 can induce apoptosis of AML HL-60 cells, which is associated with the inhibition of MCL-1,C-MYC and JAK2/STAT3, and down-regulation of miR-17-92 family. Key words: Leukemia, myeloid, acute MicroRNAs Cyclin-dependent kinases/ biosynthesis Janus kinases STAT3 transcription factor Protein-tyrosine kinases/metabolism Signal transduction HL-60 cells Apoptosis Tumor cells, cultured