Nishizawa M, Tsuchiya M, Watanabe-Fukunaga R, Nagata S
Osaka Bioscience Institute, Japan.
J Biol Chem. 1990 Apr 5;265(10):5897-902.
Some human carcinoma cells constitutively produce granulocyte colony-stimulating factor (G-CSF) which stimulates the proliferation and differentiation of the progenitor cells of neutrophilic granulocytes. By introducing mouse G-CSF chromosomal gene or its promoter DNA into human carcinoma cell lines of CHU-2, SK-HEP-1, and U-87MG, it was shown that the constitutive expression of G-CSF in these carcinoma cells was due to the intrinsic activation of nuclear factors which work on the promoter region of the G-CSF gene. A series of 5' deletion mutants, linker scanning mutants, and internal deletion mutants was constructed in the promoter of mouse G-CSF gene and was introduced into human CHU-2 cells to analyze their promoter activities. These studies demonstrated that at least three regulatory elements in the promoter of the G-CSF gene are essential for the constitutive expression of G-CSF in CHU-2 cells. These elements include the consensus decanucleotide "GAGRTTCCA/CC" present on G-CSF, granulocyte/macrophage colony-stimulating factor, and interleukin 3 genes and the "ATTTGCAT" octamer transcription factor binding site. Some point mutations in these consensus sequences significantly diminished the promoter activity in CHU-2 cells.
一些人类癌细胞组成性地产生粒细胞集落刺激因子（G-CSF），该因子可刺激嗜中性粒细胞祖细胞的增殖和分化。通过将小鼠G-CSF染色体基因或其启动子DNA导入CHU-2、SK-HEP-1和U-87MG等人癌细胞系，结果表明这些癌细胞中G-CSF的组成性表达是由于作用于G-CSF基因启动子区域的核因子的内在激活。在小鼠G-CSF基因的启动子中构建了一系列5'缺失突变体、接头扫描突变体和内部缺失突变体，并将其导入人CHU-2细胞以分析其启动子活性。这些研究表明，G-CSF基因启动子中至少有三个调控元件对于CHU-2细胞中G-CSF的组成性表达至关重要。这些元件包括存在于G-CSF、粒细胞/巨噬细胞集落刺激因子和白细胞介素3基因上的共有十聚体“GAGRTTCCA/CC”以及“ATTTGCAT”八聚体转录因子结合位点。这些共有序列中的一些点突变显著降低了CHU-2细胞中的启动子活性。
