Asiedu C, Biggs J, Lilly M, Kraft A S
Division of Hematology/Oncology, University of Alabama, Birmingham 35294, USA.
Cancer Res. 1995 Sep 1;55(17):3716-20.
Bryostatin 1 is a natural antineoplastic agent that activates protein kinase C. Treatment of U937 human leukemic cells with bryostatin 1 caused a 60% reduction in cell growth, whereas another protein kinase C activator, phorbol myristate acetate (PMA), completely inhibited U937 cell growth. Both bryostatin 1 and PMA induced inhibition of cyclin-dependent kinase 2 (cdk2) activity. The first phase of cdk2 inhibition correlated with the transient induction of p21, a known inhibitor of cdk2. In contrast, the second phase of cdk2 inhibition correlated with the dephosphorylation of cdk2 on threonine-160, which must be phosphorylated for cdk2 activity. The level of growth inhibition induced by these two compounds correlated with the degree of cdk2 dephosphorylation as follows: bryostatin 1, 60%; PMA, 100%.
苔藓抑素1是一种激活蛋白激酶C的天然抗肿瘤药物。用苔藓抑素1处理U937人白血病细胞可使细胞生长减少60%，而另一种蛋白激酶C激活剂佛波醇肉豆蔻酸酯乙酸酯（PMA）则完全抑制U937细胞生长。苔藓抑素1和PMA均诱导细胞周期蛋白依赖性激酶2（cdk2）活性的抑制。cdk2抑制的第一阶段与p21的短暂诱导相关，p21是一种已知的cdk2抑制剂。相反，cdk2抑制的第二阶段与cdk2苏氨酸-160位点的去磷酸化相关，该位点必须磷酸化才能使cdk2具有活性。这两种化合物诱导的生长抑制水平与cdk2去磷酸化程度相关，如下所示：苔藓抑素1，60%；PMA，100%。
