Schutte B, Nieland L, van Engeland M, Henfling M E, Meijer L, Ramaekers F C
Department of Molecular Cell Biology and Genetics, University of Maastricht, The Netherlands.
Exp Cell Res. 1997 Oct 10;236(1):4-15. doi: 10.1006/excr.1997.3700.
The effect of the cyclin-dependent (CDK) inhibitors olomoucine and roscovitine on cell kinetics was studied. To this end, nonsmall cell lung cancer (NSCLC) cell line MR65 and neuroblastoma cell line CHP-212 were pulse labeled with bromodeoxyuridine (BrdUrd) and chased in culture medium, to which various concentrations of olomoucine or roscovitine were added. A dose-dependent inhibition of the G1/S-phase and G2/ M-/G1 transitions was observed. Furthermore, S-phase progression was also inhibited in a dose-dependent manner. Similarly, roscovitine, another CDK inhibitor with a 10-fold higher efficiency for both CDK1 and CDK2 as compared to olomoucine, showed the same effects at a 10-fold lower concentration. At the highest tested doses both olomoucine (200 microM) and roscovitine (40 microM) induced a complete cell cycle block in both cell lines, paralleled by the appearance of apoptotic figures. In these cultures a decrease in CDK1 protein level was found as shown by Western blotting. Bivariate CDK1/DNA analysis confirmed these observations and showed that a subpopulation of cells with characteristics of apoptosis became CDK1 negative. The presented data suggest that cyclins and CDKs are involved at an important nodal point shared by pathways regulating cellular proliferation and apoptosis.
研究了细胞周期蛋白依赖性激酶（CDK）抑制剂olomoucine和roscovitine对细胞动力学的影响。为此，用溴脱氧尿苷（BrdUrd）对非小细胞肺癌（NSCLC）细胞系MR65和成神经细胞瘤细胞系CHP-212进行脉冲标记，并在添加了不同浓度olomoucine或roscovitine的培养基中进行追踪培养。观察到G1/S期和G2/M-/G1期转换受到剂量依赖性抑制。此外，S期进程也受到剂量依赖性抑制。同样，与olomoucine相比，对CDK1和CDK2效率高10倍的另一种CDK抑制剂roscovitine在低10倍的浓度下也表现出相同的效果。在最高测试剂量下，olomoucine（200 microM）和roscovitine（40 microM）均在两种细胞系中诱导了完全的细胞周期阻滞，并伴有凋亡形态的出现。在这些培养物中，通过蛋白质印迹法发现CDK1蛋白水平降低。双变量CDK1/DNA分析证实了这些观察结果，并表明具有凋亡特征的细胞亚群变为CDK1阴性。所呈现的数据表明，细胞周期蛋白和CDK参与了调节细胞增殖和凋亡的途径所共有的一个重要节点。
