Expression of tetraspanins in human lung cancer cells : frequent downregulation of CD9 and its contribution to cell motility in small cell lung cancer

四跨膜蛋白在人肺癌细胞中的表达：CD9的频繁下调及其对小细胞肺癌细胞运动的贡献

基本信息

批准号：
15590807
负责人：
KAWASE Ichiro
金额：
$ 2.24万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15590807/
关键词：
lung cancer tetraspanin CD9 integrin metastasis cell motility cell adhesion

项目摘要

Small cell lung cancer (SCLC) invades locally and metastasizes distantly extremely early when compared with non-small cell lung cancer (NSCLC). The underlying molecular mechanisms, however, have not been elucidated. Accumulating evidence suggests that down-regulation of several members of tetraspanins is associated with progression of solid tumors, thus indicating poor prognosis. Here we screened 30 lung cancer cell lines for expression of tetraspanins, CD9,CD63,CD81,CD82,CD151, and NAG-2. Flow cytometry revealed that, among these proteins, CD9 is broadly expressed in NSCLC lines, but is absent or highly reduced in most SCLC lines (p<0.0001). Using the Boyden chamber and videomicroscopic cell motility assays, we showed that stable transfection of CD9 into a SCLC line, OS3-R5, reduced cell motility on fibronectin. Furthermore, by transient transfection of green fluorescent protein (GFP)-tagged CD9 into three other SCLC lines, we observed that SCLC cells expressing GFP-CD9 were uniformly less motile than untransfected cells. CD9 or GFP-CD9 was associated with b1integrins and distributed at the tumor cell periphery and cell-cell contacts, suggesting that CD9 modifies b1 integrin function to reduce motility. These findings suggest that low expression of CD9 may contribute to the highly invasive and metastatic phenotype of SCLC.

与非小细胞肺癌（NSCLC）相比，小细胞肺癌（SCLC）在局部侵入，并非常早就转移。但是，尚未阐明潜在的分子机制。积累的证据表明，几个四叠碱成员的下调与实体瘤的进展有关，从而表明预后不良。在这里，我们筛选了30个肺癌细胞系，用于表达四叠腺苷，CD9，CD63，CD81，CD82，CD151和NAG-2。流式细胞仪表明，在这些蛋白质中，CD9在NSCLC系中广泛表达，但在大多数SCLC系中不存在或高度降低（P <0.0001）。使用Boyden腔室和视频显微细胞运动性测定，我们表明CD9稳定地转染到SCLC系列OS3-R5中，可降低纤连蛋白上的细胞运动性。此外，通过将绿色荧光蛋白（GFP）的CD9瞬时转染到其他三种SCLC系中，我们观察到表达GFP-CD9的SCLC细胞比未转染的细胞均匀地倾斜。 CD9或GFP-CD9与B1integrins有关，并分布在肿瘤细胞周围和细胞 - 细胞接触处，这表明CD9修饰了B1整合素功能以降低运动性。这些发现表明，CD9的低表达可能有助于SCLC的高度侵入性和转移性表型。