The Structural Function of Nestin in Cell Body Softening is Correlated with Cancer Cell Metastasis
The Structural Function of Nestin in Cell Body Softening is Correlated with Cancer Cell Metastasis
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DOI：
10.7150/ijbs.33423
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发表时间：
2019-01-01
影响因子：
9.2
通讯作者：
Nakamura, Chikashi
中科院分区：
文献类型：
--
作者：
Yamagishi, Ayana;Susaki, Moe;Nakamura, Chikashi
中间纤维在控制细胞硬度和侵袭能力方面起着重要作用。巢蛋白是一种VI型中间丝蛋白，在几种高转移癌细胞中高度表达。虽然巢蛋白表达的抑制被证明可以降低肿瘤细胞的转移能力，但该蛋白与癌细胞转移机制之间的关系仍不清楚。在这里，我们表明，巢蛋白软化高转移性小鼠乳腺癌细胞系FP 10 SC2的细胞体，从而提高转移能力。邻位连接实验显示巢蛋白敲除细胞中肌动蛋白和波形蛋白之间的结合增加。由于巢蛋白与波形蛋白共聚，并且巢蛋白在其C-末端区域具有极长的尾域，我们假设尾域作为波形蛋白-肌动蛋白相互作用的空间抑制剂起作用，并抑制波形蛋白丝与皮质肌动蛋白细胞骨架的缔合，从而导致细胞刚度降低。为了证明这一功能，我们机械地拉波形蛋白丝在活细胞中使用纳米针修饰波形蛋白特异性抗体的操作下，通过原子力显微镜（AFM）。拉伸试验显示，FP 10 SC2细胞中巢蛋白的表达增加了波形蛋白细丝的流动性。
Intermediate filaments play significant roles in governing cell stiffness and invasive ability. Nestin is a type VI intermediate filament protein that is highly expressed in several high-metastatic cancer cells. Although inhibition of nestin expression was shown to reduce the metastatic capacity of tumor cells, the relationship between this protein and the mechanism of cancer cell metastasis remains unclear. Here, we show that nestin softens the cell body of the highly metastatic mouse breast cancer cell line FP10SC2, thereby enhancing the metastasis capacity. Proximity ligation assay demonstrated increased binding between actin and vimentin in nestin knockout cells. Because nestin copolymerizes with vimentin and nestin has an extremely long tail domain in its C-terminal region, we hypothesized that the tail domain functions as a steric inhibitor of the vimentin-actin interaction and suppresses association of vimentin filaments with the cortical actin cytoskeleton, leading to reduced cell stiffness. To demonstrate this function, we mechanically pulled vimentin filaments in living cells using a nanoneedle modified with vimentin-specific antibodies under manipulation by atomic force microscopy (AFM). The tensile test revealed that mobility of vimentin filaments was increased by nestin expression in FP10SC2 cells.