Background

Alpha-1-syntrophin (SNTA1) is emerging as a novel modulator of the actin cytoskeleton. SNTA1 binds to F-actin and regulates intracellular localization and activity of various actin organizing signaling molecules. Aberration in syntrophin signaling has been closely linked with deregulated growth connected to tumor development/metastasis and its abnormal over expression has been observed in breast cancer. In the present work the effect of jasplakinolide, an actin-binding cyclodepsipeptide, on the SNTA1 protein activity and SNTA1 mediated downstream cellular events was studied in MDA-MB-231 breast cancer cell line.

Methods

SNTA1 protein levels and phosphorylation status were determined in MDA-MB-231 cells post jasplakinolide exposure using western blotting and immunoprecipitation techniques respectively. MDA-MB-231 cells were transfected with WT SNTA1 and DM SNTA1 (Y^215/229 phospho mutant) and simultaneously treated with jasplakinolide. The effect of jasplakinolide and SNTA1 protein on cell migration was determined using the boyden chamber assay.

Results

Jasplakinolide treatment decreases proliferation of MDA-MB-231 cells in both dose and time dependent manner. Results suggest that subtoxic doses of jasplakinolide induce morphological changes in MDA-MB-231 cells from flat spindle shape adherent cells to round weakly adherent forms. Mechanistically, jasplakinolide treatment was found to decrease SNTA1 protein levels and its tyrosine phosphorylation status. Moreover, migratory potential of jasplakinolide treated cells was significantly inhibited in comparison to control cells.

Conclusion

Our results demonstrate that jasplakinolide inhibits cell migration by impairing SNTA1 functioning in breast cancer cells

中文翻译：

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Jasplakinolide 通过阻止乳腺癌细胞中的 α-1-syntrophin 蛋白磷酸化来减弱细胞迁移

背景

Alpha-1-syntrophin (SNTA1) 正在成为一种新型的肌动蛋白细胞骨架调节剂。SNTA1 与 F-肌动蛋白结合并调节各种肌动蛋白组织信号分子的细胞内定位和活性。Syntrophin 信号传导的异常与与肿瘤发展/转移相关的失调生长密切相关，并且在乳腺癌中观察到其异常过度表达。在目前的工作中，在 MDA-MB-231 乳腺癌细胞系中研究了 jasplakinolide（一种肌动蛋白结合环缩肽）对 SNTA1 蛋白活性和 SNTA1 介导的下游细胞事件的影响。

方法

分别使用蛋白质印迹和免疫沉淀技术测定茉莉花内酯暴露后 MDA-MB-231 细胞中的 SNTA1 蛋白水平和磷酸化状态。MDA-MB-231 细胞用 WT SNTA1 和 DM SNTA1（Y ^215/229磷酸突变体）转染，同时用茉莉花内酯处理。jasplakinolide 和 SNTA1 蛋白对细胞迁移的影响使用博登室测定法确定。

结果

Jasplakinolide 治疗以剂量和时间依赖性方式降低 MDA-MB-231 细胞的增殖。结果表明，亚毒性剂量的茉莉花内酯可诱导 MDA-MB-231 细胞从扁平纺锤形贴壁细胞到圆形弱贴壁细胞的形态变化。从机制上讲，发现 jasplakinolide 治疗会降低 SNTA1 蛋白水平及其酪氨酸磷酸化状态。此外，与对照细胞相比，jasplakinolide 处理的细胞的迁移潜力被显着抑制。

结论

我们的结果表明，jasplakinolide 通过损害 SNTA1 在乳腺癌细胞中的功能来抑制细胞迁移