Zhu Xia-Yin, Guo Qun-Yi, Zhu Min, Chen Bao-Guo, Wang Ling-Yan, Zhang Dan-Qiong, Zhang Li, Shao Yan-Ping, Luo Wen-Da
Department of Hematology, Taizhou Hospital of Zhejiang, Wenzhou Medical College, Taizhou, Zhejiang 317000, P.R. China.
Department of Central Laboratory, Taizhou Hospital of Zhejiang, Wenzhou Medical College, Taizhou, Zhejiang 317000, P.R. China.
Oncol Lett. 2020 Aug;20(2):1888-1896. doi: 10.3892/ol.2020.11718. Epub 2020 Jun 9.
Acute myelogenous leukemia (AML) is a class of malignant tumors derived from hematopoietic stem or progenitor cells. The H2.0-like homeobox gene (HLX) encodes transcription factors that function in promoting normal hematopoietic cell proliferation and tumor immunity. The present study analyzed the effect of downregulating the HLX on cell cycle distribution and cell proliferation in AML. Moreover, the current study detected changes in the expression of genes and proteins in the Janus kinase (JAK)/STAT signaling pathway to investigate the mechanism of the action of HLX in tumor immunity in AML. HLX expression in AML cell lines was silenced using small interfering siRNA, and MTS/PMS-assay colorimetric assays were used to assess the effect of knockdown of HLX on AML cell proliferation. Flow cytometry was used to analyze changes in cell cycle distribution, while reverse transcription-quantitative PCR and western blotting were used to detect changes in the expression levels of key components of the JAK/STAT signaling pathway, such as p21-activated kinase 1 (PAK1), neuropilin 1 (NRP1), B-cell translocation gene 1 (BTG1) and STAT5. It was found that HLX was differentially expressed in AML cell lines of various subtypes, and HLX expression was higher in the AML/M3 subtype NB4 cell line compared with the control group. Knockdown of HLX in NB4 cells significantly inhibited cell proliferation and arrested cells in the G/G phase. Moreover, STAT5 protein expression, as well as NRP1 and PAK1 expression levels were downregulated, while BTG1 expression was upregulated when HLX was knocked out by siRNA. Collectively, the results suggested that downregulation of HLX may cause G/G phase arrest and inhibit the proliferation of AML cells by activating the JAK/STAT signaling pathway.
急性髓系白血病（AML）是一类源自造血干细胞或祖细胞的恶性肿瘤。类H2.0同源框基因（HLX）编码在促进正常造血细胞增殖和肿瘤免疫中发挥作用的转录因子。本研究分析了下调HLX对AML细胞周期分布和细胞增殖的影响。此外，本研究检测了Janus激酶（JAK）/信号转导和转录激活因子（STAT）信号通路中基因和蛋白质表达的变化，以探讨HLX在AML肿瘤免疫中的作用机制。使用小干扰siRNA使AML细胞系中的HLX表达沉默，并使用MTS/PMS比色法评估敲低HLX对AML细胞增殖的影响。流式细胞术用于分析细胞周期分布的变化，而逆转录定量PCR和蛋白质印迹法用于检测JAK/STAT信号通路关键成分如p21激活激酶1（PAK1）、神经纤毛蛋白1（NRP1）、B细胞易位基因1（BTG1）和STAT5表达水平的变化。研究发现，HLX在各亚型AML细胞系中存在差异表达，与对照组相比AML/M3亚型NB4细胞系中HLX表达更高。敲低NB4细胞中的HLX可显著抑制细胞增殖并使细胞停滞于G/G期。此外，当通过siRNA敲除HLX时，STAT5蛋白表达以及NRP1和PAK1表达水平下调，而BTG1表达上调。总体而言，结果表明下调HLX可能通过激活JAK/STAT信号通路导致G/G期停滞并抑制AML细胞的增殖。
