Differential regulation of rho GTPases during lung adenocarcinoma migration and invasion reveals a novel role of the tumor suppressor StarD13 in invadopodia regulation
Differential regulation of rho GTPases during lung adenocarcinoma migration and invasion reveals a novel role of the tumor suppressor StarD13 in invadopodia regulation
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DOI：
10.1186/s12964-020-00635-5
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发表时间：
2020-09-08
影响因子：
8.4
通讯作者：
El-Sibai, Mirvat
中科院分区：
文献类型：
--
作者：
Al Haddad, Maria;El-Rif, Rayane;El-Sibai, Mirvat
背景：肺癌是第二大常见癌症。转移和扩散到远处的能力使肿瘤更具侵略性。小GTP结合蛋白（GTP酶）的Rho亚家族的成员在肌动蛋白细胞骨架的调节以及癌细胞迁移和转移中起核心作用。本研究旨在探讨RhoA/Cdc 42 GAP，即StarD 13在肺癌细胞A549恶性化、迁移和侵袭中的作用。方法：采用时间推移成像和侵袭实验检测StarD 13对肺癌细胞A549迁移和侵袭伪足形成的影响。我们还进行了救援实验，以确定下游的StarD 13的信号通路和转染细胞与FRET生物传感器RhoGTPases，以确定参与invadopodia formation.Results的蛋白质：我们观察到的StarD 13在肺肿瘤组织中的表达水平下降相比，正常肺组织通过免疫组化。与正常肺细胞WI 38相比，StarD 13在肺腺癌细胞系A549中的表达也较低。此外，StarD 13的耗尽增加了WI 38和A549细胞中的细胞增殖和活力，表明StarD 13可能是肺癌中的潜在肿瘤抑制因子。然而，StarD 13的耗尽抑制了细胞运动性，相反地证明了在细胞迁移中的积极调节作用。这可能是由于通过下拉和FRET测定检测到的RhoA的组成型激活。令人惊讶的是，StarD 13通过抑制Cdc 42介导的侵袭伪足形成来抑制细胞侵袭。事实上，TKS 4染色和侵袭伪足测定显示StarD 13消耗增加Cdc 42活化以及侵袭伪足形成和基质降解。耗尽StarD 13的正常肺细胞也产生侵袭伪足，否则是侵袭性癌细胞的独特标志。Cdc 42敲低模仿了StarD 13的作用，而组成型活性Cdc 42的过表达模仿了其耗尽的作用。最后，免疫染色和FRET分析显示，没有StarD 13在invadopodia相比，Cdc 42，这是激活invadopodia在网站的matrix degradation.Conclusion：总之，StarD 13起着独特的作用，肺癌细胞的迁移和侵袭，通过其差异调节Rho GTPases。
Background: Lung cancer is the second most commonly occurring cancer. The ability to metastasize and spread to distant locations renders the tumor more aggressive. Members of the Rho subfamily of small GTP-binding proteins (GTPases) play a central role in the regulation of the actin cytoskeleton and in cancer cell migration and metastasis. In this study we investigated the role of the RhoA/Cdc42 GAP, StarD13, a previously described tumor suppressor, in malignancy, migration and invasion of the lung cancer cells A549.Methods: We knocked down StarD13 expression in A549 lung cancer cells and tested the effect on cell migration and invadopodia formation using time lapse imaging and invasion assays. We also performed rescue experiments to determine the signaling pathways downstream of StarD13 and transfected the cells with FRET biosensors for RhoGTPases to identify the proteins involved in invadopodia formation.Results: We observed a decrease in the level of expression of StarD13 in lung tumor tissues compared to normal lung tissues through immunohistochemistry. StarD13 also showed a lower expression in the lung adenocarcinoma cell line A549 compared to normal lung cells, WI38. In addition, the depletion of StarD13 increased cell proliferation and viability in WI38 and A549 cells, suggesting that StarD13 might potentially be a tumor suppressor in lung cancer. The depletion of StarD13, however, inhibited cell motility, conversely demonstrating a positive regulatory role in cell migration. This was potentially due to the constitutive activation of RhoA detected by pull down and FRET assays. Surprisingly, StarD13 suppressed cell invasion by inhibiting Cdc42-mediated invadopodia formation. Indeed, TKS4 staining and invadopodia assay revealed that StarD13 depletion increased Cdc42 activation as well as invadopodia formation and matrix degradation. Normal lung cells depleted of StarD13 also produced invadopodia, otherwise a unique hallmark of invasive cancer cells. Cdc42 knock down mimicked the effects of StarD13, while overexpression of a constitutively active Cdc42 mimicked the effects of its depletion. Finally, immunostaining and FRET analysis revealed the absence of StarD13 in invadopodia as compared to Cdc42, which was activated in invadopodia at the sites of matrix degradation.Conclusion: In conclusion, StarD13 plays distinct roles in lung cancer cell migration and invasion through its differential regulation of Rho GTPases.