1α,25-(OH)_2维生素D3联合转化生长因子β1体外对U937细胞作用及其机理

Study on the effect of 1α,25-(OH)_2 Dihydroxyvitamin and TGF-β1 on leukemic cells line U937

目的 :探讨 1α ,2 5 (OH) 2 VitD3和 /或TGF β1在体外对U937细胞的作用。 方法 :应用流式细胞技术、免疫细胞化学、图像分析及原位杂交 (ISH)、酶联免疫吸附实验 (ELISA)等方法观察不同剂量VitD3下U937细胞周期、细胞增殖及分化情况及TGF β1mRNA和TGF β1的表达。 结果 :在VitD3联合TGF β1作用下 ,U937细胞增殖明显受抑 ,细胞阻滞于G0 /G1期 ,与两者单独作用相比 ,相差显著 (P <0 .0 5 )。两者联和作用时CD14阳性表达增强 ,强于两者单独作用时 (P <0 .0 1)。同时在VitD3作用下U937细胞显示TGF β1mRNA和TGF β1表达增强 ,与VitD3的剂量成正比。 结论 :VitD3有体外抗U937细胞增殖和促其分化成熟作用 ,联合TGF β1后其抑制作用明显增强 ,并使细胞周期阻滞于G0 /G1期。一定剂量范围的VitD3能促进U937细胞自分泌TGF β1,并下调C mycmRNA表达 ,这可能是VitD3联合TGF β1诱导U937细胞分化的一个途径。

Objective:To observe the effect of VitD3 and/or TGF β1 on acute promonocytic leukemia cell line U937.Methods:The cell cycle,proliferation and differentiation were studied by typanblue dye exclusion,light microscope,immunocytochemistry (ICC),flow cytometry(FCM)and image analyser.The expressions of TGF β1 mRNA and TGF β1 were studied by in situ hybridization(ISH)and enzyme linked immunosorbent assays(ELISA).Results:VitD3 combined with TGF β1 could obviously inhibit the proliferation of U937 cells and interfer the growth in G0/G1 phase.These effects were significant than those using VitD3 or TGF β1 alone ( P <0.05).VitD3 combined with TGF β1 could develop the expression of CD14 and down regulate expression of C-myc mRNA.They were also significant than those using VitD3 or TGF β1 alone by image analysis ( P <0.01).The expressions of TGF β1 mRNA and TGF β1 of U937 cell were developed with the development of the dose of VitD3(25,250,2 500 ng·ml 1 ).Conclusion:VitD3 could inhibit the proliferation and induce the differentiation of U937 cells.VitD3 combined with TGF β1 had significant effects of inhibition on U937 cell and interfer U937 cell in G0/G1 phase.Definite dose of VitD3 could induce U937 cells to autocrine TGF β1 and down regulate expression of C myc mRNA.