Extracellular heat shock protein A9 is a novel interaction partner of podoplanin in oral squamous cell carcinoma cells
Extracellular heat shock protein A9 is a novel interaction partner of podoplanin in oral squamous cell carcinoma cells
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细胞外热休克蛋白 A9 是口腔鳞状细胞癌细胞中足足蛋白的新型相互作用伴侣
DOI：
10.1016/j.bbrc.2013.03.057
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发表时间：
2013
影响因子：
3.1
通讯作者：
Masayuki Tsuneki
中科院分区：
文献类型：
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作者：
Misuzu Nakamura,Alan T Lefor,Yoshinori Hosoya,Yuichiro Doki;Masahiko Yano;駒瀬勝啓;Masayuki Tsuneki
在以前的研究中，我们已经显示了几条证据表明，podoplanin（PDPN）通过其与肿瘤条件下的细胞外成分的关联在细胞粘附中起着重要的作用，尽管还没有尝试在细胞外环境中寻找PDPN相互作用分子。为了筛选这些分子，我们进行了基于蛋白质组学的分析，使用液相色谱-串联质谱法，然后在ZK-1，口腔鳞状细胞癌（SCC）细胞系统，其细胞膜分子在其细胞外室中相互交联的PDPN免疫共沉淀，我们确定热休克蛋白（HSP）A9作为细胞外PDPN结合分子之一。在ZK-1中通过siRNA瞬时敲低PDPN的效果也在HSPA 9表达和分泌方面对细胞行为进行了比较性检查。最后，HSPA 9的表达模式在口腔鳞癌组织标本中进行了免疫组化可视化。ZK-1细胞能分泌HSPA 9，且HSPA 9基因和蛋白的表达和分泌水平与PDPN的表达和分泌水平具有良好的协调性。免疫组化显示，HSPA 9和PDPN共定位于ZK-1细胞和口腔SCC病灶中，尤其是外周区。总之，结果表明，口腔鳞癌细胞分泌的HSPA 9以自分泌方式与细胞表面的PDPN相互作用，并调节其生长和侵袭力。
In previous studies, we have shown several lines of evidence that podoplanin (PDPN) plays an important role in cell adhesion via its association with extracellular components in neoplastic conditions, though there has been no trial to search for PDPN-interaction molecules in the extracellular milieu. To screen for those molecules, we performed proteomics-based analysis using liquid chromatography-tandem mass spectrometry followed by co-immunoprecipitation for PDPN in ZK-1, an oral squamous cell carcinoma (SCC) cell system whose cell membrane molecules were cross-linked with each other in their extracellular compartments, and we identified heat shock protein (HSP) A9 as one of the extracellular PDPN bound molecules. Effects of transient PDPN knockdown by siRNA in ZK-1 were also comparatively examined for cellular behaviors in terms of HSPA9 expression and secretion. Finally, HSPA9 expression modes were immunohistochemically visualized in oral SCC tissue specimens. HSPA9 was secreted from ZK-1 cells, and the expression and secretion levels of HSPA9 gene and protein were well coordinated with those of PDPN. Immunohistochemically, HSPA9 and PDPN were co-localized in ZK-1 cells and oral SCC foci, especially in the peripheral zone. In conclusion, the results indicate that HSPA9 secreted by oral SCC cells interacts with PDPN on their cell surface in an autocrine manner and regulates their growth and invasiveness.