蛋白激酶C亚型在HL-60细胞诱导分化中的变化

CHANGES OF PKC ISOFORMSIN INDUCED DIFFEREN-TIATION OF HL-60 CELLS BY ATRA AND PMA

用全反式维甲酸(ATRA)或佛波酯(PMA)处理人早幼粒白血病细胞(HL-60)3天,用形态学,NBT还原实验,特异性和非特异性酯酶测定,证明细胞分别向粒细胞或单核/巨噬细胞分化。通过免疫组化法观察了蛋白激酶C(PKC)α,βⅠ和βⅡ亚型在分化后的变化。结果显示,ATRA可引起HL-60细胞PKCα,βⅠ和βⅡ的含量升高,分别为对照的5.0,2.8和4.2倍,并存在从胞膜向胞质转位。PMA则使PKCα和βⅡ的表达水平下降,而PKCβⅠ增高,且三种亚型均在核内有不同程度的表达。结果提示HL-60细胞向粒细胞的分化可能需要PKCα和PKCβ评的持续激活,而PKC的核内转位可能是HL-60细胞分化为单核/巨噬细胞的重要环节。

Human premyeloid leukemic cell line (HL-60) were differentiated along granu-locytic or monocytic/phagocytic lineage respectively by the treatment of all-trans retinoic acid (ATRA) or phorbol ester (PMA), which was demonstrated by morphological observation, NBT reduction test, specific and nonspecific assay of es-terases. By use of immuno-histochemical method, the changes of protein kinase C (PKC) isoforms α, βⅠ and βⅡ after induced differentiation of HL-60 cells were studied. The results showed that ATRA led to 5.0, 2.8 and 4.2 times increase of PKCα,βⅠ and βⅡ isoforms respectively as compared with the undifferentiated control levels and translocation of PKC from membrane to cytosol. The level of PKC a and βⅡ isoforms in HL-60 cells induced by PMA were decreased, but the expression of PKCβⅠ was increased. Besides, PMA led these 3 kinds of PKC to be present in cell nucleus with different intensity. These results suggest that the sustained activation of PKC a and 3 may be required for granulocytic differentiation of HL-60 cells, while nuclear translocation of PKC may relatively be an important step for differentiation of HL-60 cells to monocytes/ macrophages.