钙调素对肿瘤细胞周期的调节作用

利用钙调素拮抗剂三氟拉嗪(TFP)研究了钙调素对HeLa细胞周期进程的影响,TFP处理的细胞被阻抑在G_1/S,使S期群体及DNA合成下降,G_2期群体增加.有丝分裂(M)前期细胞减少,中期细胞增加.结果表明钙调素对G_1至S期.G_2至M期和M中期至M后期具有调节作用,钙调素通过细胞周期中上述3个位点对肿瘤细胞增殖进行调节.

REGULATORY FUNCTIONS OF CALMODULIN FOR CELL CYCLE PROGRESSION IN TUMOR CELLS

To study the role of calmodulin (CaM) in cell proliferation, a CaM an- tagonist, trifluoperazine (TFP) is used in this experiment. Cultured HeLa cells are treated with TFP. The TFP treated cells show declined DNA synthesis and inhibited cell growth. Flow-cell spectrometer results reveal that increased population of cycle cells at G_1 and G_2/M phase and reduced population at S phase. The mitotic index of TFP treated cells is not influenced but the increased percentage of metaphase chromosomes and reduced percentage of prophase in mitotic figures should suggest a prolonged G, phase and metaphase in TFP treated cells. The results indicate that calmodulin is important in controlling progression at three points in the Hela cell cycle:(1)The G_1/S boundary to permit the initiation of DNA synthesis, (2) The G_2/M boundary to permit the initiation of mitosis and (3) at the metaphase/anaphase tran- sition of mitosis to permit chromosome segregation and the completion of mitosis.