Tumor protein D54 is a negative regulator of extracellular matrix-dependent migration and attachment in oral squamous cell carcinoma-derived cell lines
Tumor protein D54 is a negative regulator of extracellular matrix-dependent migration and attachment in oral squamous cell carcinoma-derived cell lines
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DOI：
10.1007/s13402-013-0131-y
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发表时间：
2013-06-01
影响因子：
6.6
通讯作者：
Shintani, Satoru
中科院分区：
文献类型：
--
作者：
Mukudai, Yoshiki;Kondo, Seiji;Shintani, Satoru
肿瘤蛋白D54(TPD54)属于TPD52家族蛋白，在包括口腔鳞状细胞癌(OSCC)在内的多种癌症中均有表达。在这里，我们研究了口腔鳞癌相关的各种特征和TPD54在体外的表达之间的关系。我们评估了TPD54在几个口腔鳞癌来源的细胞系和正常、非恶性细胞中的表达。根据获得的结果，口腔鳞癌来源的SAS细胞随后受到TPD54选择性剪接变异体(ASV)的外源过表达以及TPD54在siRNA介导下的敲除。接下来，我们研究了TPD54在口腔鳞癌细胞生长、凋亡、侵袭、迁移和细胞外基质(ECM)依赖的迁移和附着中的作用，以及伴随而来的整合素和整合素相关蛋白的表达。在单层培养实验中，外源性ASV过表达和TPD54基因敲除都不能调节SAS细胞的增殖或侵袭。然而，外源ASV过表达确实降低了锚定非依赖性生长，而TPD54基因敲除确实增加了锚定非依赖性生长，而与caspase活性无关。在细胞外基质依赖的细胞迁移和细胞对细胞外基质的附着方面也观察到了同样的效果。主要的整合素α和β亚基以及E-钙粘附素的表达水平与未转染的对照细胞相似，而TPD54基因敲除后talin1的表达增加。此外，还发现，即使在没有血清刺激的情况下，TPD54基因敲除后Akt也被激活。在口腔鳞癌来源的细胞系HSC-2和HSC-3中也观察到了非常相似的作用。我们的结果表明，TPD54通过Talin1介导的ECM内向外信号调节整合素的激活，从而影响OSCC细胞与ECM的附着、OSCC细胞的迁移和Akt/PKB的激活。基于这些结果，我们认为TPD54可能成为口腔鳞癌的一个新的生物标志物，并可能成为口腔鳞癌治疗的靶点。
Tumor protein D54 (TPD54) belongs to the TPD52 family of proteins and is expressed in several types of cancer, including oral squamous cell carcinoma (OSCC). Here, we investigated relationships between various OSCC-related characteristics and TPD54 expression in vitro.The expression of TPD54 in several OSCC-derived cell lines and normal, non-malignant, cells was assessed. Based on the results obtained, OSCC-derived SAS cells were subsequently subjected to exogenous over-expression of alternative splice variants (ASVs) of TPD54 and to TPD54 knock-down, mediated by siRNA. Next, the role of TPD54 in cellular growth, apoptosis, invasion, migration and extracellular-matrix (ECM)-dependent migration and attachment was investigated, as also the concomitant expression of integrins and integrin-related proteins by the OSCC-derived cells.Western blot analysis and RT-PCR revealed that several TPD54 ASVs were expressed in the OSCC-derived cell lines tested. Neither exogenous ASV over-expression nor TPD54 knock-down modulated the proliferation or invasion of SAS cells in a monolayer culture assay. However, exogenous ASV over-expression did decrease anchorage-independent growth and TPD54 knock-down did increase anchorage-independent growth, irrespective of caspase activities. The same effects were observed on ECM-dependent cellular migration and cell attachment to the ECM. The expression levels of the major alpha and beta integrin subunits, and of E-cadherin, were found to be similar to those observed in the non-transfected control cells, whereas talin1 expression was found to be increased after TPD54 knock-down. Also Akt was found to be activated after TPD54 knock-down, even in the absence of serum stimulation. Very similar effects were observed in the OSCC-derived cell lines HSC 2 and HSC 3.Our results show that TPD54 affects OSCC cell attachment to the ECM, OSCC cell migration, and Akt/PKB activation by modulating integrin activation via a talin1-mediated inside-out signal of the ECM. Based on these results, we suggest that TPD54 may serve as a novel biomarker for OSCC and as a putative target for OSCC therapy.