Chen Y, Williams B R
Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic Foundation, OH 44195, USA.
Gene Expr. 2000;9(3):103-14. doi: 10.3727/000000001783992614.
The Wilms tumor suppressor gene, WT1, plays an important role in genitourinary development and the etiology of Wilms tumor. WT1 has a spatially and temporally defined expression in the developing genitourinary system and in specific cells of the hematopoietic system, but the regulatory pathways that control WT1 expression are not well understood. Recently, members of the NF-kappaB family of transcription factors have been proposed as potent activators of the murine WT1 promoter through binding to a NF-kappaB site. Because the human WT1 promoter contains a conserved NF-kappaB site, we investigated whether NF-kappaB also regulates the expression of the human WT1 gene. We activated NF-kappaB through cytokine stimulation or inhibited NF-kappaB through expression of a NF-kappaB "super repressor" in WT1 expressing Wilms tumor, renal carcinoma, and erythroleukemia cultures and examined the level of endogenous WT1 gene expression. Although a transfected NF-kappaB reporter construct was responsive to these manipulations, we found that altering NF-kappaB activity had no effect on endogenous WT1 expression in the cell types used in our study. We conclude that despite the presence of conserved NF-kappaB elements in the murine and human WT1 promoters, NF-kappaB is not required to regulate the expression of the WT1 gene in its natural context.
肾母细胞瘤抑癌基因WT1在泌尿生殖系统发育及肾母细胞瘤的病因学中发挥着重要作用。WT1在发育中的泌尿生殖系统及造血系统的特定细胞中具有时空特异性表达，但调控WT1表达的信号通路尚未完全明确。最近，有研究提出转录因子NF-κB家族成员可通过与NF-κB位点结合，从而有效激活小鼠WT1启动子。由于人类WT1启动子含有保守的NF-κB位点，我们研究了NF-κB是否也调控人类WT1基因的表达。我们通过细胞因子刺激激活NF-κB，或在表达WT1的肾母细胞瘤、肾癌及红白血病细胞培养物中通过表达NF-κB“超级抑制因子”抑制NF-κB，并检测内源性WT1基因的表达水平。尽管转染的NF-κB报告基因构建体对这些操作有反应，但我们发现在我们研究使用的细胞类型中，改变NF-κB活性对内源性WT1表达没有影响。我们得出结论，尽管在小鼠和人类WT1启动子中存在保守的NF-κB元件，但在自然环境下NF-κB并非调控WT1基因表达所必需。
