Hidaka M, Nakakuma H, Kawaguchi T, Nagakura S, Horikawa K, Okuno Y, Kagimoto T, Takatsuki K
Second Department of Internal Medicine, Kumamoto University Medical School, Japan.
Int J Hematol. 1992 Oct;56(2):135-41.
Protein kinase C (PKC) has been shown to be involved in the mitogenic response and in oncogenic cell transformation in many experimental models. We analyzed the expression of PKC in both highly purified leukemic T cells freshly isolated from adult T-cell leukemia (ATL) patients and control T lymphocytes obtained from healthy volunteers. PKC activity was decreased in the ATL cells as compared with the control T cells. Cytosolic PKC activity in the ATL cells was remarkably decreased, whereas particulate membrane PKC activity was similar to the control level. The percentage of PKC activity in the particulate fraction was 34% in the ATL cells and 19% in the control cells. Regarding the altered subcellular localization of PKC activity, phorbol ester-induced translocation of cytosolic PKC was inhibited in some ATL cases. Similarly to the decrease in PKC activity, there was a decrease in the expression of the major PKC isozymes II(beta) and III(alpha) in ATL cells. These results suggest impaired regulation of PKC expression in ATL as well as in many experimental cancers.
蛋白激酶C（PKC）已被证明在许多实验模型中参与促有丝分裂反应和致癌细胞转化。我们分析了从成人T细胞白血病（ATL）患者新鲜分离的高度纯化白血病T细胞和从健康志愿者获得的对照T淋巴细胞中PKC的表达。与对照T细胞相比，ATL细胞中的PKC活性降低。ATL细胞中的胞质PKC活性显著降低，而颗粒膜PKC活性与对照水平相似。颗粒部分中PKC活性的百分比在ATL细胞中为34%，在对照细胞中为19%。关于PKC活性的亚细胞定位改变，在一些ATL病例中，佛波酯诱导的胞质PKC易位受到抑制。与PKC活性降低相似，ATL细胞中主要PKC同工酶II（β）和III（α）的表达也降低。这些结果表明，ATL以及许多实验性癌症中PKC表达的调节受损。
