Y-盒结合蛋白1对白血病K562细胞多药耐药基因-1表达的调控

Regulation of Y-box protein 1 on the induced expression of mdr1 gene in human leukemia cell line K562

目的:观察多柔比星诱导K562细胞多药耐药基因-1(mdr1)基因表达过程中Y-盒结合蛋白1(YB-1)表达和核易位的变化情况,初步探讨YB-1蛋白对mdr1基因的转录调控。方法:多柔比星间歇性长期作用于K562细胞,剂量逐渐增加。RT-PCR检测mdr1,YB-1基因表达,流式细胞仪检测mdr1基因编码的P糖蛋白(P-gp)表达,蛋白质印迹检测YB-1蛋白核易位。通过RNA干扰技术使K562细胞中YB-1基因表达沉默,多柔比星处理YB-1基因沉默细胞,RT-PCR、流式细胞仪分别检测mdr1 mRNA和P-gp的表达。结果:经多柔比星作用后K562细胞mdr1基因转录上调,P-gp表达增加,同时YB-1基因转录也增强,且出现明显的核易位。YB-1基因沉默后,mdr1基因诱导性表达减少。结论:多柔比星诱导K562细胞mdr1基因表达的过程中,YB-1对于mdr1基因的转录活化起一定的作用。

Objective： To investigate the effect of YB-1 on the transcription of mdrl gene. Methods： K562 cells were treated with doxorubicin （DOX） at different concentrations and times. Expression of mdrl and YB-1 genes were examined by reverse transcription-polymerase chain reaction （RT-PCR）. P-glycoprotein （P-gp） was detected by flow cytometry. Cyto/nuclear protein was extracted for Western blotting to detect YB-1. To inhibit the expression of YB-1 gene in K562 cell using RNA interference （RNAi）targeting YB-1 gene, then detect the expression of mdrl and P-gp in YB-1 gene silenced cells after treated with DOX. Resuits： When K562 cells were exposured to DOX, the mdrl gene was highly expressed as well as its corresponding protein P-gp. Further, DOX up-regulated the expression of YB-1 gene, and promoted YB-1 protein translocate to nucleus. Another, when YB-1 gene was silenced, the expression of mdrl gene and P-gp were obviously decreased in K562 cells treated with DOX. Conclusion： Doxorubicin could induce the expression of mdrl gene in K562 cells, it may be due to YB-1 activating the transcription of mdrl gene.