Wang Hui, Linghu Hua, Wang Jin, Che Ya-ling, Xiang Ting-xiu, Tang Wei-xue, Yao Zhen-wei
Department of Obstetrics and Gynecology, The First Affiliated Hospital, Chongqing Medical University, Chongqing, 400016, China.
Tumour Biol. 2010 Jan;31(1):59-67. doi: 10.1007/s13277-009-0009-9. Epub 2009 Dec 23.
Small GTPases, particularly the Rho family, are key regulators of cell motility and migration. Dock180 was well known for the main target of signal adaptor protein Crk and acted as a guanine-nucleotide exchange factor for small GTPase Rac1. In the present study, Dock180 was found to combine primarily with CrkI other than CrkII, and its association with Elmo1 was also demonstrated in ovarian cancer cell SKOV3. To evaluate the role of Dock180 in human ovarian cancer cell, we performed RNAi-mediated knockdown of Dock180 in SKOV3 cells using small interfering RNA expression vector. In Dock180 knockdown cells, we found that Elmo1 expression and Rac1 activity were decreased simultaneously. By contrast, the expressions of both another Crk-combining molecule C3G and Rap1 activity were observed to increase obviously. Accordingly, all Dock180 knockdown cells present with evident change in cell morphology, reduced cell proliferation, and attenuated cell migration. Taken together, these results suggest that signal transfer of Crk/Dock180/Rac1 is implicated in actin cytoskeleton reorganization and thus in the cell proliferation, motility, invasion, and of human ovarian cancer cell line SKOV3.
小GTP酶，尤其是Rho家族，是细胞运动和迁移的关键调节因子。Dock180作为信号衔接蛋白Crk的主要靶点而广为人知，并作为小GTP酶Rac1的鸟嘌呤核苷酸交换因子发挥作用。在本研究中，发现Dock180主要与CrkI而非CrkII结合，并且在卵巢癌细胞SKOV3中也证实了它与Elmo1的关联。为了评估Dock180在人卵巢癌细胞中的作用，我们使用小干扰RNA表达载体在SKOV3细胞中进行了RNAi介导的Dock180敲低。在Dock180敲低的细胞中，我们发现Elmo1表达和Rac1活性同时降低。相比之下，观察到另一个与Crk结合的分子C3G的表达和Rap1活性明显增加。因此，所有Dock180敲低的细胞都呈现出明显的细胞形态变化、细胞增殖减少和细胞迁移减弱。综上所述，这些结果表明Crk/Dock180/Rac1信号转导与肌动蛋白细胞骨架重组有关，从而与人类卵巢癌细胞系SKOV3的细胞增殖、运动、侵袭有关。
