The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel.
Cell Signal. 2011 Dec;23(12):1936-43. doi: 10.1016/j.cellsig.2011.07.001. Epub 2011 Jul 12.
Gliomas are characterized by increased infiltration into the surrounding normal brain tissue. We recently reported that RTVP-1 is highly expressed in gliomas and plays a role in the migration of these cells, however the regulation of RTVP-1 expression in these cells is not yet described. In this study we examined the role of PKC in the regulation of RTVP-1 expression and found that PMA and overexpression of PKCα and PKCε increased the expression of RTVP-1, whereas PKCδ exerted an opposite effect. Using the MatInspector software, we identified a SRF binding site on the RTVP-1 promoter. Chromatin immunoprecipitation (ChIP) assay revealed that SRF binds to the RTVP-1 promoter in U87 cells, and that this binding was significantly increased in response to serum addition. Moreover, silencing of SRF blocked the induction of RTVP-1 expression in response to serum. We found that overexpression of PKCα and PKCε increased the activity of the RTVP-1 promoter and the binding of SRF to the promoter. In contrast, overexpression of PKCδ blocked the increase in RTVP-1 expression in response to serum and the inhibitory effect of PKCδ was abrogated in cells expressing a SRFT160A mutant. SRF regulated the migration of glioma cells and its effect was partially mediated by RTVP-1. We conclude that RTVP-1 is a PKC-regulated gene and that this regulation is at least partly mediated by SRF. Moreover, RTVP-1 plays a role in the effect of SRF on glioma cell migration.
神经胶质瘤的特点是浸润到周围正常脑组织中。我们最近报道 RTVP-1 在神经胶质瘤中高度表达，并在这些细胞的迁移中发挥作用，但这些细胞中 RTVP-1 表达的调节尚未描述。在这项研究中，我们研究了 PKC 在 RTVP-1 表达调节中的作用，发现 PMA 和 PKCα 和 PKCε 的过表达增加了 RTVP-1 的表达，而 PKCδ 则产生相反的效果。使用 MatInspector 软件，我们在 RTVP-1 启动子上鉴定到一个 SRF 结合位点。染色质免疫沉淀 (ChIP) 实验显示，SRF 在 U87 细胞中结合到 RTVP-1 启动子上，并且这种结合在添加血清后显著增加。此外，SRF 的沉默阻断了血清诱导的 RTVP-1 表达。我们发现 PKCα 和 PKCε 的过表达增加了 RTVP-1 启动子的活性和 SRF 与启动子的结合。相反，PKCδ 的过表达阻断了血清反应中 RTVP-1 表达的增加，并且在表达 SRFT160A 突变体的细胞中，PKCδ 的抑制作用被消除。SRF 调节神经胶质瘤细胞的迁移，其作用部分由 RTVP-1 介导。我们得出结论，RTVP-1 是一个 PKC 调节的基因，这种调节至少部分是由 SRF 介导的。此外，RTVP-1 在 SRF 对神经胶质瘤细胞迁移的作用中发挥作用。
