Specific induction of migration and invasion of pancreatic carcinoma cells by RhoC, which differs from RhoA in its localisation and activity
Specific induction of migration and invasion of pancreatic carcinoma cells by RhoC, which differs from RhoA in its localisation and activity
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DOI：
10.1515/bc.2009.110
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发表时间：
2009-10-01
影响因子：
3.7
通讯作者：
Giehl, Klaudia
中科院分区：
文献类型：
--
作者：
Dietrich, Karin-Almut;Schwarz, Rene;Giehl, Klaudia
RhoA和RhoC是高度相关的Rho GTP酶，但差异控制细胞行为。我们结合了分子、细胞和生化实验来验证这些高度相似的GTP酶之间的差异。我们的研究结果表明，RhoC的表达增强导致胰腺癌细胞的迁移和侵袭显著增加，而RhoA的强制表达则降低了这些作用。这些亚型特异性功能与RhoA和RhoC在人类细胞中的细胞活性差异相关，在活性测定和血清反应因子依赖性基因转录中RhoC比RhoA更活跃。亚细胞定位研究表明，RhoC主要定位在含膜部分，而RhoA主要定位在细胞质部分。这些差异不是由与RhoGDIs的不同相互作用介导的。在体外GTP/GDP结合分析表明不同的亲和力RhoC GTPwSx和更快的内在和鸟嘌呤核苷酸交换因子（GEF）刺激的GDP/GTP交换速率相比，RhoA。此外，SopE和Dbs的催化结构域是RhoC的有效GEF。RhoC的mRNA表达在晚期胰腺癌阶段显著增强，因此RhoA和RhoC之间发现的差异可能为它们对细胞迁移和肿瘤侵袭的不同影响提供解释。
RhoA and RhoC are highly related Rho GTPases, but differentially control cellular behaviour. We combined molecular, cellular, and biochemical experiments to characterise differences between these highly similar GTPases. Our findings demonstrate that enhanced expression of RhoC results in a striking increase in the migration and invasion of pancreatic carcinoma cells, whereas forced expression of RhoA decreases these actions. These isoform-specific functions correlate with differences in the cellular activity of RhoA and RhoC in human cells, with RhoC being more active than RhoA in activity assays and serum-response factor-dependent gene transcription. Subcellular localisation studies revealed that RhoC is predominantly localised in the membrane-containing fraction, whereas RhoA is mainly localised in the cytoplasmic fraction. These differences are not mediated by a different interaction with RhoGDIs. In vitro GTP/GDP binding analyses demonstrate different affinity of RhoC for GTPwSx and faster intrinsic and guanine nucleotide exchange factor (GEF)-stimulated GDP/GTP exchange rates compared to RhoA. Moreover, the catalytic domains of SopE and Dbs are efficacious GEFs for RhoC. mRNA expression of RhoC is markedly enhanced in advanced pancreatic cancer stages, and thus the differences discovered between RhoA and RhoC might provide explanations for their different influences on cell migration and tumour invasion.