H-ras transformation sensitizes volume-activated anion channels and increases migratory activity of NIH3T3 fibroblasts
H-ras transformation sensitizes volume-activated anion channels and increases migratory activity of NIH3T3 fibroblasts
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DOI：
10.1007/s00424-007-0367-3
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发表时间：
2008-03-01
影响因子：
4.5
通讯作者：
Schwab, Albrecht
中科院分区：
文献类型：
--
作者：
Schneider, Linda;Klausen, Thomas K.;Schwab, Albrecht
H-ras癌基因的表达增加了多种细胞的迁移活性，从而促进了肿瘤细胞的转移行为。其他研究指出，容量激活的阴离子通道(Vrac)参与(肿瘤)细胞的迁移。在这篇文章中，我们测试了VRAC是否需要刺激H-ras癌基因表达的细胞迁移。我们用膜片钳技术和延时视频显微镜比较了野生型和H-ras转化的NIH3T3成纤维细胞vrac的激活和迁移。通过将细胞外渗透压从300mOsm/L降低到190mOsm/L，两种细胞在最大刺激下获得相同程度的vrac激活。但是，当生理上相关的细胞外渗透压降低(275mOsm/L)时，转化H-ras的成纤维细胞的vrac激活水平几乎是野生型成纤维细胞的三倍。Vrac敏感性的增加伴随着H-ras成纤维细胞迁移活性的增加。此外，高亲和力vrac阻滞剂NS3728剂量依赖性地抑制H-ras成纤维细胞的迁移，而野生型成纤维细胞的迁移仅减少约35%。与在H-ras中比在野生型成纤维细胞中更高的vrac活性一致，需要更多的vrac阻滞剂才能达到同等程度的迁移抑制。我们认为，H-ras调节vrac的体积设定点，从而促进细胞更快迁移所需的细胞体积的瞬时变化。
The expression of the H-ras oncogene increases the migratory activity of many cell types and thereby contributes to the metastatic behavior of tumor cells. Other studies point to an involvement of volume-activated anion channels (VRAC) in (tumor) cell migration. In this paper, we tested whether VRACs are required for the stimulation of cell migration upon expression of the H-ras oncogene. We compared VRAC activation and migration of wild-type and H-ras-transformed NIH3T3 fibroblasts by means of patch-clamp techniques and time-lapse video microscopy. Both cell types achieve the same degree of VRAC activation upon maximal stimulation, induced by reducing extracellular osmolarity from 300 to 190 mOsm/l. However, upon physiologically relevant reductions in extracellular osmolarity (275 mOsm/l), the level of VRAC activation is almost three times higher in H-ras-transformed compared to wild-type fibroblasts. This increase in VRAC sensitivity is accompanied by increased migratory activity of H-ras fibroblasts. Moreover, the high-affinity VRAC blocker NS3728 inhibits migration of H-ras fibroblasts dose-dependently by up to about 60%, whereas migration of wild-type fibroblasts is reduced by only about 35%. Consistent with higher VRAC activity in H-ras than in wild-type fibroblasts, more VRAC blocker is needed to achieve a comparable degree of inhibition of migration. We suggest that H-ras modulates the volume set point of VRAC and thus facilitates transient changes of cell volume required for faster cell migration.