TNF-α在PMA和IFN-γ诱导U 937细胞生长和分化过程中的作用

THE ROLE OF TNF-α IN THE GROWTH AND DIFFERENTIATION OF U 937 CELLS INDUCED BY PMA AND IFN-γ

本文报道了佛波酯(PMA)和γ-干扰素(IFN-γ)对U937细胞生长和分化的调控作用及其机制。PMA和IFN-γ能以剂量依赖的方式诱导U937细胞向成熟单核/巨噬细胞样细胞分化,同时抑制其细胞的生长。实验发现PMA和IFN-γ可诱导U937细胞表达TNF-α特异性mRNA和蛋白质。U937细胞培养中加入特异性抗TNF-α抗体可以抑制PMA和IFN-γ诱导U937细胞的分化和生长。这说明内源性的TNF-α在介导PMA和IFN-γ上述生物效应过程中起一定作用。

The effects of PMA and IFN-γ on regulation of growth and differentiation of human monoblastic leukemic cell U937 were examined. U 937 cells were stimulated by different concentrations of PMA and IFN-γ respectivelty and NBT reduction assay was used to detect the differentiation of the cells. The results showed that both PMA and IFN-γ dose-dependently induced differentiation of U 937 cells into mature macrophage-like cells. The data also revealed a time-course response in the differentiation induction. Moreover, the U 937 cell growth was significantly inhibited by the treatment of PMA and IFN-γ.These results suggested that PMA and IFN-γ coupled the regulation of U 937 cell growth and differentiation. It was found that tumor necrosis factor-α (TNF-α) was expressed by the stimulated U 937 cells. The specific monoclonal antibody against TNF-α diminised the effects of PMA and IFN-γ on the growth and differentiation of U 937 cells. Thus the endogenous TNF-α may involved in the mechanism of the effects of PMA and IFN-γ on the differentiation of U 937 cells. The regulatory action of the endogenous TNF-α on U 937 cells was not due to its cytotoxic effect.