Kharbanda S, Yuan Z M, Taneja N, Weichselbaum R, Kufe D
Division of Cancer Pharmacology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115.
Oncogene. 1994 Oct;9(10):3005-11.
The present studies have examined the effects of mitomycin C (MMC), a genotoxic alkylating agent, on the activation of Src-like protein tyrosine kinases in HL-60 myeloid leukemia cells. The results demonstrate no detectable induction of p59fyn or pp60c-src activity. The response of HL-60 cells to MMC however was associated with rapid activation of p56/p53lyn. Similar findings were obtained with other alkylating agents such as nitrogen mustard and cis-platinum. Activation of p56/p53lyn was associated with increased autophosphorylation on tyrosine and sensitivity to the tyrosine kinase inhibitors herbimycin A and genistein. Studies with a glutathione S-transferase-Lyn fusion protein were performed to explore the potential significance of p56/p53lyn activation. Analysis of the adsorbates demonstrates interaction of Lyn with the cell cycle regulatory protein, p34cdc2. Coimmunoprecipitation studies further confirmed the association of p56/p53lyn and p34cdc2 in MMC-treated cells. We also demonstrate that p34cdc2 undergoes increased phosphorylation on tyrosine following MMC exposure and that p56/p53lyn phosphorylates the Tyr-15 site of p34cdc2 in vitro. These findings indicate that the cellular response to MMC includes activation of p56/p53lyn and that this event may contribute to signals transduced by the DNA damage-dependent mitotic checkpoint.
本研究检测了具有基因毒性的烷化剂丝裂霉素C（MMC）对HL-60髓系白血病细胞中Src样蛋白酪氨酸激酶激活的影响。结果显示未检测到p59fyn或pp60c-src活性的诱导。然而，HL-60细胞对MMC的反应与p56/p53lyn的快速激活相关。用其他烷化剂如氮芥和顺铂也获得了类似的结果。p56/p53lyn的激活与酪氨酸自身磷酸化增加以及对酪氨酸激酶抑制剂赫曲霉素A和染料木黄酮的敏感性相关。进行了谷胱甘肽S-转移酶-Lyn融合蛋白的研究以探讨p56/p53lyn激活的潜在意义。对吸附物的分析表明Lyn与细胞周期调节蛋白p34cdc2相互作用。免疫共沉淀研究进一步证实了在MMC处理的细胞中p56/p53lyn与p34cdc2的关联。我们还证明，MMC处理后p34cdc2的酪氨酸磷酸化增加，并且p56/p53lyn在体外磷酸化p34cdc2的Tyr-15位点。这些发现表明细胞对MMC的反应包括p56/p53lyn的激活，并且这一事件可能有助于由DNA损伤依赖性有丝分裂检查点转导的信号。
