Svensson Emelie, Eriksson Helena, Gekas Christos, Olofsson Tor, Richter Johan, Gullberg Urban
Department of Hematology, Lund University, BMC, C14, S-221 84 Lund, Sweden.
Exp Cell Res. 2005 Aug 1;308(1):211-21. doi: 10.1016/j.yexcr.2005.04.018.
The Wilms tumor gene 1 (WT1) encodes a zinc-finger-containing transcription factor highly expressed in immature hematopoietic progenitor cells. Overexpression and presence of somatic mutations in acute leukemia indicate a role for WT1 in the pathogenesis of leukemia. CD34+ progenitor cells were transduced with one splice variant of human WT1 without the KTS insert in the zinc-finger domain, WT1(+/-), and with a deleted mutant of WT1 lacking the entire zinc-finger region, WT1(delZ), thus incapable of binding DNA. We show that inhibition of erythroid colony formation and differentiation is absolutely dependent on the DNA-binding zinc-finger domain of WT1. Unexpectedly, however, WT1(delZ) was equally effective as wild type protein in the reduction of myeloid clonogenic growth as well as in stimulation of myeloid differentiation, as judged by the expression of cell surface CD11b. Expression of neither WT1(+/-) nor WT1(delZ) upregulated mRNA for the cdk inhibitor p21(Waf1/Cip1) or p27Kip1. Our results demonstrate that WT1 affects proliferation and differentiation in erythroid and myeloid cells by different molecular mechanisms, and suggest that mutations affecting the zinc-finger domain of WT1 could interfere with normal differentiation in the pathogenesis of leukemia.
威尔姆斯瘤基因1（WT1）编码一种含锌指结构的转录因子，在未成熟造血祖细胞中高度表达。急性白血病中WT1的过表达和体细胞突变表明其在白血病发病机制中发挥作用。用锌指结构域中无KTS插入的人WT1的一种剪接变体WT1(+/-)，以及缺失整个锌指区域因而无法结合DNA的WT1缺失突变体WT1(delZ)转导CD34+祖细胞。我们发现，对红系集落形成和分化的抑制绝对依赖于WT1的DNA结合锌指结构域。然而，出乎意料的是，根据细胞表面CD11b的表达判断，WT1(delZ)在减少髓系克隆生长以及刺激髓系分化方面与野生型蛋白同样有效。WT1(+/-)和WT1(delZ)均未上调细胞周期蛋白依赖性激酶抑制剂p21(Waf1/Cip1)或p27Kip1的mRNA表达。我们的结果表明，WT1通过不同的分子机制影响红系和髓系细胞的增殖和分化，并提示影响WT1锌指结构域的突变可能在白血病发病机制中干扰正常分化。
