Down-regulation of CD9 in human ovarian carcinoma cell might contribute to peritoneal dissemination:: Morphologic alteration and reduced expression of β1 integrin subsets
Down-regulation of CD9 in human ovarian carcinoma cell might contribute to peritoneal dissemination:: Morphologic alteration and reduced expression of β1 integrin subsets
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DOI：
10.1158/0008-5472.can-04-3123
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发表时间：
2005-04-01
期刊：
影响因子：
11.2
通讯作者：
Ishikura, H
中科院分区：
文献类型：
--
作者：
Furuya, M;Kato, F;Ishikura, H
腹膜播散是癌症患者死亡的主要原因之一。转移的病理生理学已经被很好地研究，但是肿瘤集落在腹膜腔中扩散扩散的机制还没有完全理解。CD 9是四跨膜蛋白的一员，已知其下调与预后不良有关。为了研究CD 9下调的意义，用针对CD 9的小干扰RNA（siRNA）瞬时转染高表达CD 9的卵巢癌细胞系HTOA，并纯化CD 9阴性细胞（HTOA（CD 9-））。与对照siRNA转染的HTOA（对照-HTOA）相比，HTOA（CD 9-）显示改变的对基质胶、胶原、纤连蛋白和层粘连蛋白的粘附模式。流式细胞术和荧光细胞染色显示HTOA（CD 9-）中整合素β 1、α 2、α 3 β 1、α 5和α 6的表达水平低于对照HTOA。HTOA（CD 9-）显示连接和细胞骨架分子的表达改变。通过延时视频显微镜，对照HTOA显示与细胞外基质的牢固粘附，形成鹅卵石图案，而HTOA（CD 9-）显示较弱的粘附，呈弥漫性斑点分布。为了检测CD 9的表达水平在肿瘤扩散过程中是否发生变化，建立了HTOA的高扩散亚克隆HTOA-P。HTOA-P在mRNA和蛋白水平上显著下调CD 9表达，并表现出与HTOA（CD 9-）相似的形态学改变。这些结果表明，CD 9的下调可能是一个获得性事件在肿瘤的传播过程中。下调的CD 9可能会减弱几种整合素的表达，并重新排列连接和细胞骨架分子，这可能有助于卵巢癌的扩散。
Peritoneal dissemination is one of the main causes of death in cancer patients. Pathophysiology of metastasis has been well investigated, but the mechanism of diffuse spread of tumor colonies in the peritoneal cavity is not fully understood. CD9 is a member of tetraspanin and its down-regulation is known to be involved in poor prognosis. To investigate the significance of the down-regulation of CD9, HTOA, an ovarian carcinoma cell line that highly expressed CD9, was transiently transfected with small interfering RNA (siRNA) against CD9, and CD9-negative cells (HTOA(CD9-)) were purified. HTOA(CD9-)showed altered adhesion patterns on Matrigel, collagen, fibronectin, and laminin compared with those of control siRNA-transfected HTOA (control-HTOA). Flow cytometry and fluorescence cytostainings revealed that the expression levels of integrins beta 1, alpha 2, alpha 3 beta 1, alpha 5, and alpha 6 were lower in HTOA(CD9-) than those of control-HTOA. HTOA(CD9-) showed altered expression of junctional and cytoskeletal molecules. By time-lapse video microscopy, control-HTOA showed solid adhesion to extracellular matrix and formed cobblestone pattern, whereas HTOA(CD9-) showed weaker adhesion and were distributed as diffuse spots. To examine whether the expression level of CD9 change during tumor dissemination, HTOA-P, a highly disseminative subclone of HTOA, was established. HTOA-P showed distinctive down-regulation of CD9 at mRNA and protein levels, and showed similar morphologic alteration as HTOA(CD9-) did. These findings indicate that the down-regulation of CD9 may be an acquired event in the process of tumor dissemination. Down-regulated CD9 may attenuate the expression of several integrins and rearrange junctional and cytoskeletal molecules that might contribute to dissemination of ovarian carcinomas.