bcr/abl mRNA反义寡核苷酸对慢性粒细胞白血病Ph~ 细胞的作用

Ph~ 慢性粒细胞白血病(CML)的bcr/abl融合基因在其发病机制中具有重要作用。为研究bcr/abl反义寡核苷酸对CML细胞的作用,将合成两种18个碱基的bcr/abl硫代反义寡核苷酸与相应CML细胞系(K562细胞)及患者细胞共同孵育。结果发现,bcr/abl反义寡核苷酸可明显抑制K562细胞生长;对CML细胞CFU-GM抑制率为54％—91％,部分病例CFU-GM可有bcr/abl mRNA消失而PCR检测为阴性。上述抑制都是序列特异性的,与剂量呈正相关关系。通过流式细胞仪PI染色分析DNA含量,检测具有凋亡间接特征的亚二倍体细胞数量,发现反义寡核苷酸诱导细胞凋亡是其主要作用机制。本实验为bcr/abl反义寡核苷酸CML基因治疗及体外骨髓净化提供了依据。

Effects of bcr/abl mRNA Antisense Oligonucleotides on Ph Positive Chronic Myelogenous Leukemia Cells

The bcr/abl gene has been documented as having a significant role to play in the pathogenesis of Ph chronic myelogenous leukemia (CML). To study the effects of the bcr/abl antisense oligonucleotides on Ph CML cells, the celis from K562 celis and patients with CML were exposed to syn-thetic 18 bp phosphorothioate oligonucleotides complementary to two identified bcr/abl junctions. We had found antisense oligonucleotides were effective in inhibiting the growth of K562 celis. The forma-tion of granulocyte - macrophage clolony (CFU - GM) from patients with CML was inhibited (54% -91% inhibition) and in some cases, no expression of bcr/abl mRNA was detected from residual colony formation by RT- PCR. The inhibition also was antisense sequence - specific and dose - depen-dent. Analysing of cellular DNA content to determine apoptosis indirectly by using propidium iodide (PI) on the flow cytometer, we found that inducing apoptosis by bcr/abl antisense oligonucleotides ap-pears to be the mainly mechanism. These data indicated that bcr/abl antisense oligonucleotides can be useful for in vivo antisense therapy and ex vivo marrow purging.