bcl-2基因反义寡核苷酸的设计与白血病细胞对Ara-C敏感性研究

寻找在bcl-2mRNA上除了起始区以外的反义寡核苷酸作用的敏感位点和观察这些核苷酸对白血病细胞的阿糖胞苷敏感性的影响。用RNAstructure软件模拟bcl-2mRNA的二级结构设计合成两端硫代修饰反义寡核苷酸，用MTT法测定抑制HL-60和K562细胞的阿糖胞苷半数抑制浓度（IC50）值；用流式细胞术检测HL-60和K562细胞凋亡率和bcl-2蛋白表达水平。结果发现，10μmol/Lbcl-2基因的反义寡核苷酸同Ara-C结合使用，能明显地抑制HL-60和K562细胞bcl-2基因蛋白的表达，促进细胞凋亡，减低Ara-C的IC50值；同时发现针对蛋白编码区的反义寡核苷酸有更强的作用。结论：除了bcl-2mRNA的起始区外，在bcl-2mRNA的其他部位存在有设计反义寡核苷酸更有效的位点，该项研究将为反义药物的设计提供新的有用途径。

Design of Antisense Oligodeoxynucleotide Targeting at bcl-2 mRNA and Observation on Its Effect on the Sensitivity of Leukemia Cells to Arabinosyl Cytosine

The effective target sites for antisense oligodeoxynucleotides (AS-ODN) on bcl-2 mRNA, except its start region, were looked for and their effects on the sensitivity of HL-60 and K562 leukemia cells to arabinosyl cytosine (Ara-C) were observed. The secondary structure of bcl-2 mRNA was simulated with RNAstructure microsoftware, and AS-ODNs, targeting at some sites, were designed and synthesizd with phosphorothioate modifying. The median inhibitory concentration (IC(50)) of Ara-C for HL-60 and K562 cells was determined with MTT method; the apoptosis rate and bcl-2 protein expression level were assayed by flow cytometry. The results showed that 10 micro mol/L bcl-2 AS-ODN combined with Ara-C inhibited the expression of bcl-2 protein, increased apoptosis in HL-60 and K562 cells and decresed IC(50) of Ara-C significantly. The AS-ODN targeting the coding region of bcl-2 mRNA had stronger effect than AS-ODN targeting the translation initiation region. In conclusion, the much more effective sites for antisense oligodeoxynucleotides to target, except translation start region, might provide a new useful way for antisense drug design.