造血干细胞向淋巴系祖细胞增殖分化过程中HOXB4基因的表达*

背景：HOXB4基因不仅能促进造血干细胞的扩增及其功能的活化与表达，而且体内试验表明它不会诱发白血病。因此更好地研究HOXB4在造血细胞增殖分化中的变化及作用对进一步研究造血干细胞的扩增可以提供更多的理论基础。 目的：观察人类脐血造血干细胞向淋巴系祖细胞增殖分化过程中HOXB4基因表达的情况及全反式维甲酸对HOXB4基因表达的影响。 方法：将培养的淋巴系造血祖细胞按干预方式不同分为2组，全反式维甲酸组：在培养体系中加入全反式维甲酸，终浓度6×10-8 mol/L。正常组：不加全反式维甲酸，代之以等量的1640培养液。观察人类脐血造血干细胞经植物血凝素诱导后，在培养第3，7，12天的淋巴细胞集落形成单位生成情况。采用实时荧光定量PCR技术检测脐血造血干细胞向淋巴系祖细胞增殖分化过程中HOXB4基因的表达水平。 结果与结论：人脐血造血干细胞向淋巴系祖细胞增殖分化过程中，HOXB4基因呈规律的表达。随培养时间推移，正常组和全反式维甲酸组HOXB4基因的表达均逐渐降低。与正常组比较，全反式维甲酸可上调HOXB4基因的表达。

HOXB4 gene expression during differentiation and proliferation of hematopoietic stem cells into lymphocyte progenitor cells

BACKGROUND: Homeobox B4 (HOXB4) gene not only promotes amplification of hematopoietic stem cells (HSCs) and activation and expression of its function, but also in vivo test suggested that HOXB4 cannot induce leukemia. Therefore, to study HOXB4 changes and effects in proliferation and differentiation of HSCs provide theoretical basis for HSCs amplification. OBJECTIVE: To observe the expression of HOXB4 gene in the proliferation and differentiation of HSCs into lymphocyte progenitor cells, and analyze the effects of all-train retinoic acid (ATRA) on HOXB4 gene. METHODS: Lymphocyte hematopoietic progenitor cells were divided into two groups. In ATRA group, 6×10-8 mol/L ATRA was added in the culture system. In normal group, an equal volume of 1640 medium was added in the culture system. The colony growth of colony forming unit-lymphocyte in the differentiation progress of the HSCs to lymphocyte progenitor cells induced by phytohemagglutinin was observed on days 3, 7 and 12 following culture. Expression of HOXB4 gene in the proliferation and differentiation of the HSCs into lymphocyte progenitor cells in vitro was detected using real-time fluorescence quantitive polymerase chain reaction. RESULTS AND CONCLUSION: HOXB4 gene has a regulatory function in the differentiation progress of the HSCs into lymphocyte progenitor cells. The expression of HOX B4 gene was diminished gradually in normal and ATRA groups over time. Compared with the normal group, HOXB4 gene was up-regulated in the ATRA group.