中文摘要：

早幼粒白血病（promyelocytic leukemia,PML）基因与维甲酸受体α（retinoic acid receptorα,RARα）基因形成PML-RARα融合基因是急性早幼粒细胞白血病（acute promyelocytic leukemia,APL）发生的分子基础,而PML在除APL外的其他髓系白血病亚型中的作用研究少见报道。为探讨PML在非APL的髓系白血病恶性表型中的调控作用及潜在机制,该文首先通过q PCR和Western blot检测了5株非APL来源的髓系白血病细胞中PML的表达水平。接着将靶向PML基因的sh RNA慢病毒（sh PML group）感染高表达PML的THP-1细胞;同时,设立未处理对照组（Mock group）和阴性对照组（Scramble group）,嘌呤霉素筛选稳定表达sh PML的细胞株。q PCR和Western blot检测sh RNA干扰效率;CCK-8检测细胞体外增殖活性,克隆形成实验检测细胞体外克隆形成能力;流式细胞术检测细胞凋亡率;Western blot检测凋亡相关蛋白质Bcl-2、Bax水平和AKT及下游靶分子Foxo3a磷酸化蛋白质水平的改变。结果显示,5株髓系白血病细胞中PML m RNA和蛋白质水平不同,其中以THP-1细胞中的PML表达水平较高。靶向PML基因的sh RNA慢病毒感染THP-1细胞后,PML m RNA和蛋白质水平均明显下降,提示成功构建稳定表达sh PML的THP-1细胞株。与Mock组和Scramble组相比,sh PML组的细胞增殖能力显著增强（P〈0.05）,细胞凋亡率显著降低（P〈0.05）;同时,抗凋亡蛋白Bcl-2水平升高、促凋亡蛋白Bax水平降低;此外,干扰PML表达可增加p AKT（S473）及下游靶分子p Foxo3a（S253）的蛋白质水平,而总AKT和Foxo3a的蛋白质水平未见明显变化。该研究的结果提示,PML基因可能通过调控AKT/Foxo3a信号通路活性抑制白血病的恶性表型,表明PML在不同白血病型别中发挥着不同的作用。

英文摘要：

The fusion ofpromyelocytic leukemia （PML） gene and the retinoic acid receptor α （RARa） gene resulting to oncogenic PML-RARa was the main molecular mechanism in the pathogenesis of acute promyelocytic leukemia （APL）, whereas few investigation are focused on the role of PML in acute myeloid leukemia subtypes other than APL. This study mainly aimed at investigating the role of PML in the proliferation and apoptosis activity of myeloid leukemia cells and its potential mechanism. Firstly, the levels of PML mRNA and protein in five myeloid leukemia cell lines were determined by qPCR and Western blot, respectively. Next, THP-1 cells with high PML expression were infected with shRNA lentivirus targeting PML （shPML group） and its negative control （Scramble group）, followed by puromycin selection. THP-1 cells untreated were named as Mock group, shRNA efficiency was confirmed by qPCR and Western blot. Cell proliferation activity was assessed by CCK-8 in vitro; Colony formation ability was analysed by colony-forming assay. The apoptosis rate was determined by flow cytometry. The protein levels of apoptosis related proteins Bcl-2 and Bax were measured by Western blot. In addition, the expression of phosphorylated-AKT （pAKT） and phosphorylated-Foxo3α （pFoxo3α） were detected by Western blot. The results showed different levels of PML mRNA and protein in myeloid leukemia cell lines, and THP- 1 cells exhibited higher PML expression. We transduced THP-1 cells with shRNA lentivirus targeting PML and confirmed knockdown of PML at mRNA and protein levels. Compared with Mock and Scramble groups, silencing PML significantly promoted cell proliferation activity and colony formation ability in vitro （P〈0.05）, and inhibited cell apoptosis （P〈0.05）. In addition, knockdown of PML up-regulated Bcl-2 protein levels and down-regulated Bax protein levels. Furthermore, suppressing PML significantly enhanced the levels ofAKT phosphorylation at residues Ser473 and its downstream Foxo3α phosphorylation at