蛋白激酶和D-鞘氨醇对人肝癌细胞磷脂酶D活力的调节  

Regulation of Phospholipase D Activity in Human Hepatocacinoma Cells by Protein Kinases and D sphingosine

作　　者：黄勇[1] 张夏英[1] 陈惠黎[1] 

机构地区：[1]上海医科大学卫生部糖复合物重点实验室,生物化学教研室,上海200032

出　　处：《生物化学与生物物理学报》1999年第5期572-576,共5页

摘　　要：为了研究蛋白激酶 Ｃ（ Ｐ Ｋ Ｃ） 和酪氨酸激酶（ Ｔ Ｐ Ｋ） 对７７２１ 人肝癌细胞中磷脂酰胆碱（ Ｐ Ｃ） 专一性磷脂酶 Ｄ（ Ｐ Ｌ Ｄ） 的调节， 测定了各种 Ｐ Ｋ Ｃ 和 Ｔ Ｐ Ｋ 抑制剂和 Ｐ Ｋ Ｃ 抗体对该细胞中 Ｐ Ｌ Ｄ 活力的影响。结果发现：４ 种 Ｐ Ｋ Ｃ 抑制剂 Ｃｈｅｌｅｒｙｔｈｒｉｎｅ， Ｈ７ ， Ｃａｌｐｈｏｓｔｉｎ Ｃ 和星形孢菌素（ Ｓｔａｕｒｏｓｐｏｒｉｎｅ） ， 以及２ 种 Ｔ Ｐ Ｋ 抑制剂 Ｔｙｒｐｈｏｓｔｉｎ ４６ 和木质异黄酮（ Ｇｅｎｉｓｔｅｉｎ） 都能部分抑制 Ｐ Ｌ Ｄ 的基础活力， 其中以星形孢菌素和 Ｃａｌｐｈｏｓｔｉｎ Ｃ 的抑制作用最强。 Ｔ Ｐ Ｋ 抑制剂的作用一般弱于 Ｐ Ｋ Ｃ 抑制剂， 但 Ｐ Ｋ Ｃ 和 Ｔ Ｐ Ｋ 抑制剂合用时， 其抑制作用大于它们单独使用时的抑制作用。一个公认的 Ｐ Ｋ Ｃ 生理抑制剂 Ｄ鞘氨醇反而激活 Ｐ Ｌ Ｄ， 其机制可能和 Ｄ鞘氨醇生成 Ｄ鞘氨醇１磷酸有关。后者能通过激活 Ｔ Ｐ Ｋ（ 或许还通过激活 Ｐ Ｋ Ｃ） 而激活 Ｐ Ｌ Ｄ。 Ｄ鞘氨醇和 Ｄ鞘氨醇１磷酸的激活作用都可被 Ｔ Ｐ Ｋ 抑制剂和其他 Ｐ Ｋ Ｃ 抑制剂所阻断。在细胞 Ｐ Ｋ Ｃ 的３ 种常见亚型中， Ｐ Ｋ Ｃα和 Ｐ Ｋ ＣβThe effects of some inhibitors of protein kinase C(PKC) and tyrosine protein kinase(TPK)as well as the antibodies to PKC isotypes on the activity of phosphatidylcholine specific phospholipase D(PLD)in 7721 human hepatocarcinoma cells were determined in order to study the regulation of PKC and TPK on PLD in these cells. It was found that all of the four inhibitors of PKC (chelerythrine, H 7, calphostin C and stausporine) and two inhibitors of TPK (tyrphostin 46 and genistein) partially inhibited the basal activity of PLD. Among them, the inhibition rates of staurosporine and calphostin C were the highest. The effects of TPK inhibitors were less than that of PKC inhibitors. When the inhibitors of PKC and TPK were added in combination, the inhibitory effect was greater than that used separately. A well known physiological inhibitor of PKC, D sphingosine, did not show any inhibition, but did show stimulation on PLD activity. The mechanism is probably related to the transformation of D sphingosine to D sphingosine 1 phosphate, a stimulator of PLD via the activation TPK (and probably also PKC). The stimulating effects of both D sphingosine and D sphingosine 1 phosphate were blocked by TPK inhibitors and other PKC inhibitors. Among the 3 common PKC isotypes in human hepatocarcinoma cells, PKCα and PKCβI may be the main isotypes of PKC in the regulation of PLD.

关 键 词：磷脂酶D 蛋白激酶 抑制剂 D鞘氨醇 肝癌 

分 类 号：R735.702[医药卫生—肿瘤]