Suppression of uPAR retards radiation-induced invasion and migration mediated by integrin β1/FAK signaling in medulloblastoma.
Suppression of uPAR retards radiation-induced invasion and migration mediated by integrin β1/FAK signaling in medulloblastoma.
复制标题
DOI：
10.1371/journal.pone.0013006
复制
发表时间：
2010-09-24
期刊：
影响因子：
3.7
通讯作者：
Rao JS
中科院分区：
文献类型：
--
作者：
Nalla AK;Asuthkar S;Bhoopathi P;Gujrati M;Dinh DH;Rao JS
尽管对癌症的早期阶段进行了有效的放疗，但一些研究已经报道了各种癌症的复发，包括髓母细胞瘤。在这里，我们试图利用辐射诱导髓母细胞瘤细胞的侵袭行为，通过比较细胞外蛋白酶活性和分子的表达模式，已知参与细胞粘附，迁移和侵袭，在未照射和照射的细胞之间。我们发现，与未辐照的髓母细胞瘤细胞相比，受辐照的髓母细胞瘤细胞的侵袭和迁移增加。RT-PCR分析证实，辐照细胞中uPA、uPAR、focal adhesion kinase （FAK）、N-Cadherin和整合素亚基（如α3、α5和β1）的表达增加。此外，我们注意到辐照细胞中FAK的酪氨酸磷酸化增加了2倍。免疫沉淀研究证实，在辐照细胞中，整合素β1和FAK的相互作用增加。此外，我们的研究结果表明，癌细胞中uPAR的过表达可以模拟辐射诱导的FAK信号的激活。此外，通过抑制FAK磷酸化，我们能够降低辐射诱导的癌细胞侵袭性。在这种情况下，我们研究了sirna介导的uPAR敲低对辐照和非辐照成神经管细胞瘤细胞迁移和粘附的影响。uPAR的下调主要通过抑制FAK、Paxillin和Rac-1/Cdc42的磷酸化来降低辐照细胞的粘附、迁移和侵袭。从免疫沉淀研究中观察到，uPAR敲低降低了病灶粘附分子之间的相互作用，如FAK、Paxillin和p130Cas，这些分子已知在癌症转移中起关键作用。预处理uPAR shRNA表达结构降低了裸鼠预先建立的髓母细胞瘤中uPAR和磷酸FAK的表达水平。综上所述，我们的研究结果表明，辐射增强了uPAR介导的FAK信号，通过靶向uPAR，我们可以在体外和体内抑制辐射激活的细胞粘附和迁移。
Despite effective radiotherapy for the initial stages of cancer, several studies have reported the recurrence of various cancers, including medulloblastoma. Here, we attempt to capitalize on the radiation-induced aggressive behavior of medulloblastoma cells by comparing the extracellular protease activity and the expression pattern of molecules, known to be involved in cell adhesion, migration and invasion, between non-irradiated and irradiated cells. We identified an increase in invasion and migration of irradiated compared to non-irradiated medulloblastoma cells. RT-PCR analysis confirmed increased expression of uPA, uPAR, focal adhesion kinase (FAK), N-Cadherin and integrin subunits (e.g., α3, α5 and β1) in irradiated cells. Furthermore, we noticed a ∼2-fold increase in tyrosine phosphorylation of FAK in irradiated cells. Immunoprecipitation studies confirmed increased interaction of integrin β1 and FAK in irradiated cells. In addition, our results show that overexpression of uPAR in cancer cells can mimic radiation-induced activation of FAK signaling. Moreover, by inhibiting FAK phosphorylation, we were able to reduce the radiation-induced invasiveness of the cancer cells. In this vein, we studied the effect of siRNA-mediated knockdown of uPAR on cell migration and adhesion in irradiated and non-irradiated medulloblastoma cells. Downregulation of uPAR reduced the radiation-induced adhesion, migration and invasion of the irradiated cells, primarily by inhibiting phosphorylation of FAK, Paxillin and Rac-1/Cdc42. As observed from the immunoprecipitation studies, uPAR knockdown reduced interaction among the focal adhesion molecules, such as FAK, Paxillin and p130Cas, which are known to play key roles in cancer metastasis. Pretreatment with uPAR shRNA expressing construct reduced uPAR and phospho FAK expression levels in pre-established medulloblastoma in nude mice. Taken together, our results show that radiation enhances uPAR-mediated FAK signaling and by targeting uPAR we can inhibit radiation-activated cell adhesion and migration both in vitro and in vivo.
登录
查看更多内容
影响因子：
8
作者：
Cheng, J. C-H;Chou, C. H.;Hsieh, C-Y
通讯作者：
Hsieh, C-Y
影响因子：
4.8
作者：
Chan, AW;Tarbell, NJ;Loeffler, JS
通讯作者：
Loeffler, JS
影响因子：
1.7
作者：
Feltbower, R;Picton, S;McKinney, P
通讯作者：
McKinney, P
影响因子：
4.8
作者：
Chaurasia, Pratima;Aguirre-Ghiso, Julio A.;Ossowski, Liliana
通讯作者：
Ossowski, Liliana
影响因子：
8
作者：
Ghiso, JAA
通讯作者：
Ghiso, JAA