Zhang Wen, Wu Nan, Li Zengxia, Wang Liying, Jin Jiawei, Zha Xi-Liang
Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai, China.
Cancer Biol Ther. 2006 Aug;5(8):1008-14. doi: 10.4161/cbt.5.8.2887. Epub 2006 Aug 7.
PPARgamma agonists were reported to be implicated in many biological functions in certain kinds of cells, however, little is known about the effects of PPARgamma on hepatocarcinoma cell. We explored the effects of rosiglitazone, a PPARgamma activator, on human hepatocarcinoma cell line BEL-7404 and its mechanism. After BEL-7404 was exposed to rosiglitazone, its migration was significantly inhibited, which associated with downregulation of the phosphorylation of Akt and FAK, while no significant change was detected in the phosphorylation of ERK after rosiglitazone treatment. It is now known that phosphorylated FAK is a substrate of PTEN and Akt phosphorylation can be regulated by PTEN via the PIP(3) level. We found rosiglitazone upregulated PTEN expression in a dose- and time-dependent manner, which was mediated by PPARgamma. Furthermore, PTEN overexpression resulted in inhibition of cell migration and PTEN knock-down blocked the effect of rosiglitazone on cell migration. It suggested that PTEN was required for rosiglitazone-induced inhibition of BEL-7404 cells migration. In conclusion, our results demonstrated that PTEN played a critical role in rosiglitazone inhibiting cell migration in BEL-7404.
据报道,PPARγ激动剂在某些类型的细胞中参与多种生物学功能,然而,关于PPARγ对肝癌细胞的影响知之甚少。我们探讨了PPARγ激活剂罗格列酮对人肝癌细胞系BEL-7404的影响及其机制。BEL-7404暴露于罗格列酮后,其迁移受到显著抑制,这与Akt和FAK磷酸化的下调有关,而罗格列酮处理后ERK磷酸化未检测到显著变化。现已知道,磷酸化的FAK是PTEN的底物,并且PTEN可通过PIP(3)水平调节Akt磷酸化。我们发现罗格列酮以剂量和时间依赖性方式上调PTEN表达,这是由PPARγ介导的。此外,PTEN过表达导致细胞迁移受到抑制,而PTEN敲低则阻断了罗格列酮对细胞迁移的影响。这表明PTEN是罗格列酮诱导的BEL-7404细胞迁移抑制所必需的。总之,我们的结果表明PTEN在罗格列酮抑制BEL-7404细胞迁移中起关键作用。