A novel, myeloid transcription factor, C/EBP epsilon, is upregulated during granulocytic, but not monocytic, differentiation
A novel, myeloid transcription factor, C/EBP epsilon, is upregulated during granulocytic, but not monocytic, differentiation
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DOI：
10.1182/blood.v90.7.2591.2591_2591_2600
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发表时间：
1997-10-01
期刊：
影响因子：
20.3
通讯作者：
Koeffler, HP
中科院分区：
文献类型：
--
作者：
Morosetti, R;Park, DJ;Koeffler, HP
人C/EBP β是一种新克隆的CCAAT/增强子结合转录因子。初步研究表明，它可能是人类骨髓造血的重要调节因子。为了阐明C/EBP β的表达范围，我们使用逆转录-聚合酶链反应（RT-PCR）分析，并检查其在28个造血和14个非造血细胞系，16个新鲜髓系白血病样本，正常人造血干细胞及其成熟后代中的表达。C/EBP mRNA在成髓细胞和早幼粒细胞细胞系（NB 4、HL 60、GFD 8）、成髓单核细胞系（U937和THP-1）、早期成髓细胞系（ML 1、KCL 22、MDS 92）和T细胞淋巴母细胞白血病细胞系CEM和HSB-2中显著表达。对于急性早幼粒细胞白血病细胞株NB 4，C/EBP家族成员中只有一个能被RT-PCR检测到。在红系、巨核细胞、嗜碱性粒细胞、B淋巴细胞和非造血细胞系中均未发现C/EBP mRNA。大多数急性髓性白血病患者的样本（12例中的11例）表达C/EBP β。北方印迹和RT-PCR分析显示，HL 60和KG-1成髓细胞系在诱导分化为巨噬细胞后，C/EBP mRNA表达下降。类似地，蛋白质印迹分析显示，在用有效的维生素DB类似物（KH 1060）处理后，随着早幼粒细胞细胞系NB 4沿着巨噬细胞样途径分化，C/EBP β蛋白的表达没有变化或略有下降。与此相反，C/EBP β蛋白水平显着增加，NB 4细胞诱导分化的粒细胞途径暴露后，g-顺式维甲酸。此外，从人类中纯化的非常早期的正常造血干细胞（CD 34（+）/CD 38（-））具有非常弱的C/EBP mRNA表达，但是随着这些细胞向粒细胞分化，水平增加。同样，纯化的粒细胞似乎比纯化的巨噬细胞表达更高水平的C/EBP β mRNA。与对照组相比，C/EBP反义寡核苷酸的加入使HL-60和NB 4细胞的克隆生长减少了约50%，而正义寡核苷酸则没有。综上所述，我们的结果表明，C/EBP β的表达仅限于造血组织，特别是髓样细胞，因为它们向粒细胞分化，并且抑制其在HL-60和NB 4成髓细胞和早幼粒细胞中的表达降低了它们的增殖能力。因此，该转录因子可能在正常骨髓发育过程中发挥重要作用。(C)1997年，美国血液学会。
Human C/EBP epsilon is a newly cloned CCAAT/enhancer-binding transcription factor. Initial studies indicated it may be an important regulator of human myelopoiesis. To elucidate the range of expression of C/EBP epsilon, we used reverse transcription-polymerase chain reaction (RT-PCR) analysis and examined its expression in 28 hematopoietic and 14 nonhematopoietic cell lines, 16 fresh myeloid leukemia samples, and normal human hematopoietic stem cells and their mature progeny. Prominent expression of C/EBP epsilon mRNA occurred in the tate myeloblastic and promyelocytic cell lines (NB4, HL60, GFD8), the myelomonoblastic cell lines (U937 and THP-1), the early myeloblast cell lines (ML1, KCL22, MDS92), and the T-cell lymphoblastic leukemia cell lines CEM and HSB-2. For the acute promyelocytic leukemia cell line NB4, C/EBP epsilon was the only C/EBP family member that was easily detected by RT-PCR. No C/EBP epsilon mRNA was found in erythroid, megakaryocyte, basophil, B lymphoid, or nonhematopoietic cell lines. Most acute myeloid leukemia samples (11 of 12) from patients expressed C/EBP epsilon. Northern blot and RT-PCR analyses showed that C/EBP epsilon mRNA decreased when the HL60 and KG-I myeloblast cell lines were induced to differentiate toward macrophages. Similarly, Western blot analysis showed that expression of C/EBP epsilon protein was either unchanged or decreased slightly as the promyelocytic cell line NB4 differentiated down the macrophage-like pathway after treatment with a potent vitamin DB analog (KH1060). In contrast, C/EBP epsilon protein levels increased dramatically as NB4 cells were induced to differentiate down the granulocytic pathway after exposure to g-cis retinoic acid. Furthermore, very early, normal hematopoietic stem cells (CD34(+)/CD38(-)), purified from humans had very weak expression of C/EBP epsilon mRNA, but levels increased as these cells differentiated towards granulocytes. Likewise, purified granulocytes appeared to express higher levels of C/EBP epsilon mRNA than purified macrophages. Addition of phosphothiolated antisense, but not sense oligonucleotides to C/EBP epsilon, decreased clonal growth of HL-60 and NB4 cells by about 50% compared with control cultures. Taken together, our results indicate that expression of C/EBP epsilon is restricted to hematopoietic tissues, especially myeloid cells as they differentiate towards granulocytes and inhibition of its expression in HL-60 and NB4 myeloblasts and promyelocytes decreased their proliferative capacity. Therefore, this transcriptional factor may play an important role in the process of normal myeloid development. (C) 1997 by The American Society of Hematology.