一种用作阴性对照的siRNA可诱导人K562细胞向红系分化

A Negative Control siRNA Induces Erythroid Differentiation in Human K562 Cells

我们发现,一种在RNA干扰实验中用作阴性对照的商业化siRNA具有明显的诱导人慢性髓性白血病K562细胞系向红系方向分化的作用.它表现为K562细胞瞬时转染该siRNA后,红系分化的特异表面标志CD235及ε-、γ-和β-珠蛋白的表达升高,GATA-2的表达降低,细胞增殖速度减慢,软琼脂克隆形成率降低,并且此过程不伴随细胞凋亡.而生物信息学分析显示,该siRNA序列与目前所有已知人类基因均无明显同源性.研究结果提示,该siRNA不适于用作红系分化实验中的阴性对照.siRNA的作用远比人们目前所知的要复杂得多,siRNA的脱靶效应应当引起研究者的足够重视,在RNA干扰实验中阴性对照siRNA的选择会极大地影响对实验结果的判读.

We found that a commercial siRNA used as negative control in RNA interference experiments was able to markedly induce erythroid differentiation in human chronic myelogenous leukemia K562 cells.After transient transfection of this siRNA into K562 cells,the erythroid differentiation-specific cell surface marker CD235 and ε-,γ-and β-globin were up-regulated.GATA-2 was down-regulated.Cell proliferation rate decreased.And colony forming ability of K562 cells in soft agar was impaired.Apoptosis was not observed in this processing.Bioinformatic analysis did not show any sequence homology between this siRNA and all known human genes.The results indicated that this siRNA cannot be used as negative control in erythroid differentiation experiments.The effect of siRNA was far more complicated than it was expected.Investigators should pay much attention to the off-target effect of siRNA.The choice of negative control siRNA in RNA interference experiments greatly influences the interpretation of the experimental results.