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 6 0和K5 6 2细胞的阿糖胞苷半数抑制浓度 (IC50 )值 ;用流式细胞术检测HL 6 0和K5 6 2细胞凋亡率和bcl 2蛋白表达水平。结果发现 ,10 μmol 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 6 0和K5 6 2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 Look for sensitive sites on antisense oligonucleotides on the bcl 2 mRNA except for the start region and observe the effect of these nucleotides on cytarabine sensitivity to leukemic cells. RNAstructure software was used to simulate the secondary structure of bcl2mRNA. The antisense oligodeoxynucleotides modified by both ends were designed and synthesized. The IC50 values ​​of HL60 and K562 cells were determined by MTT assay. Flow cytometry was used to detect the apoptosis rate and bcl 2 protein expression in HL 60 and K5 6 2 cells. The results showed that 10 μmol Lbcl 2 antisense oligonucleotide combined with Ara C could significantly inhibit the expression of bcl 2 protein in HL 60 and K5 6 2 cells, promote apoptosis and decrease the IC50 of Ara C Value; At the same time, it was found that antisense oligonucleotides targeting protein coding region had a stronger effect. CONCLUSIONS: In addition to the initiation region of bcl 2 mRNA, there are more sites at which antisense oligonucleotides are designed to be located elsewhere in the bcl 2 mRNA, providing a new and useful avenue for antisense drug design