Notch配体刺激白血病细胞内Cleaved Notch1蛋白及基因的表达

Transition of Cleaved Notch1 protein and gene expression changes in myeloblastic leukemia cells stimulated with Notch ligands

背景:Notch信号系统对干细胞的自身复制与分化有调节的作用。目的:监测Notch配体刺激下白血病细胞蛋白与基因表达的变化,解析Notch信号系统在细胞内的作用。方法:应用被Notch配体包被的培养皿,培养TMD7和THP-1细胞株,进行短期细胞增殖效果的评估。并且在刺激不同时间段后,应用免疫印迹法对Notch蛋白的活性进行检测,应用定量RT-PCR法测定各种基因表达的变化。结果与结论:Notch配体刺激对TMD7细胞株的增殖有促进作用,对THP-1细胞株的增殖有抑制作用。配体刺激下,免疫印记结果显示2种不同相对分子质量的活性化Notch1蛋白片段。配体刺激后,各种基因的发现量的变化是不同的。而同一细胞株对3种Notch配体刺激的反应基本类似。可见Notch信号系统比现在所知道的更为复杂,可能存在着两种正向和负向的影响。

BACKGROUND： Notch activation by ligand stimulation regulates the growth of acute myeloid leukemia cells. However, the molecular mechanisms underlying this have not been fully elucidated. OBJECTIVE： To observe the effect of cleavage of Notch1 protein and gene expression in the leukemia cell lines stimulated with Notch ligands. METHODS： Two acute myeloid leukemia cell lines, THP-1 and TMD7, and three Notch ligands, Jagged1, Dll1 and Dll4, were used. The effects of the ligands on cell growth, cleavage of Notch1, and the expression of various genes were examined by cell culture, immunoblotting, and quantitative RT-PCR, respectively. RESULTS AND CONCLUSION： Ligand stimulation suppressed the growth of the THP-1 cells but promoted that of the TMD7 cells. Immunoblots showed two Cleaved Notch1 bands, which became intense with different peak time from the start of stimulation. Ligand stimulation changed the expression levels of various genes related to cell proliferation. Some genes changed in opposite directions in the two cell lines. The three ligands had similar effects on gene expression.