RNA结合蛋白质HuR通过增加YAP1 mRNA稳定性促进白血病细胞增殖

RNA-Binding Protein HuR Promotes Proliferation of Acute Myeloid Leukemia Cells by Increasing Stability of YAP1 mRNA

RNA结合蛋白质人类抗原R(Hu R)与多种实体肿瘤的发生发展密切相关,但其在人急性髓系白血病(acutemyeloidleukemia,AML)中的功能和分子机制仍未阐明。本研究收集了30例临床初诊的AML病人和30例正常对照的外周血,分离单个核细胞,进行RT-qPCR法检测。结果显示,与正常对照相比,HuR在AML病人中呈显著表达上调趋势(3.17±1.12,P<0.05)。在AML细胞系HL-60中的功能检测发现,敲低内源性HuR后,对HL-60细胞培养12 h(0.17±0.07),24 h(0.38±0.05),36 h(0.51±0.03),48 h(0.69±0.05),60 h(0.92±0.08)和72 h(1.04±0.10)的增殖产生抑制作用(P<0.05)。同时,阻滞在G1期(47.3%±5.4)的HL-60细胞比例显著升高(P<0.05),而S期(37.5%±6.9)细胞比例显著降低(P<0.05)。相反,HuR的表达抑制对HL-60细胞向单核系分化产生促进作用。RNA免疫共沉淀法检测发现,HuR可与Hippo通路的Yes相关蛋白1关键效应基因(YAP1)的mRNA结合。后续的RNA稳定性检测发现,HuR的结合可以增强YAP1 mRNA的稳定性,进而促进YAP1的表达,并进一步影响YAP1下游基因的转录。综上所述,RNA结合蛋白质HuR可通过促进Hippo通路YAP1的表达参与AML发生发展的调节。

RNA-binding protein human antigen R(HuR)has been revealed to participate in the regulation of different solid tumors.However,HuR involvement in human acute myeloid leukemia(AML)has not been defined.The peripheral blood mononuclear cells from 30 AML patients and normal controls were isolated.Total RNA was extracted from peripheral blood mononuclear cells and the expression of HuR was detected by RT-qPCR.Results showed that the level of HuR was significantly increased in AML patients when compared with normal controls(3.17±1.12,P<0.05).Knock-down of HuR inhibited the proliferation at 12 h(0.17±0.07),24 h(0.38±0.05),36 h(0.51±0.03),48 h(0.69±0.05),60 h(0.92±0.08)and 72 h(1.04±0.10)as compared with the control(P<0.05).Additionally,knock-down of HuR repressed cell cycle at G1 phase(47.3%±5.4,P<0.05)of HL-60 cells,whereas promoted the monocytic differentiation.RNA immunoprecipitation analysis showed that HuR could bind to YAP1 mRNA and regulate its stability.Thereby,reduced HuR repressed Yesassociated protin 1(YAP1)expression in HL-60 cells.Finally,YAP1 regulated the transcription of its downstream target genes.Taken together,our study indicated that the RNA binding protein HuR can be involved in the regulation of the development of AML by promoting the expression of Hippo pathway effector YAP1.