Hirano T, Higuchi T, Katsuragawa H, Inoue T, Kataoka N, Park K R, Ueda M, Maeda M, Fujiwara H, Fujii S
Department of Gynecology and Obstetrics, Faculty of Medicine, Kyoto University, Japan.
Mol Hum Reprod. 1999 Feb;5(2):168-74. doi: 10.1093/molehr/5.2.168.
The CD9 molecule is expressed on human extravillous trophoblasts, which invade the endometrium during implantation and placentation. To elucidate the role of CD9 in trophoblastic function, we investigated the expression of CD9 protein and mRNA in BeWo cells, a human trophoblast-like choriocarcinoma cell line, using immunohistochemistry, Western blotting and reverse transcription-polymerase chain reaction (RT-PCR). When BeWo cells were cultured with anti-CD9 monoclonal antibodies (mAb), their invasion through the extracellular matrices was significantly enhanced in a dose-dependent manner. Cell proliferation and human chorionic gonadotrophin production were unaffected. On the other hand, culture in the presence of mAb against integrins alpha3, alpha5 and beta1, which partially block the interaction with the extracellular matrices, inhibited BeWo cell invasion. Anti-CD9 monoclonal antibody had a stimulatory effect on BeWo cell invasion in the presence of anti-integrin alpha3 antibody. In contrast, it had no effect in the presence of mAb against integrins alpha5 and beta1, which were also highly expressed on BeWo cells. These findings suggest that CD9 has a function connected with the invasive properties of BeWo cells, which is partially mediated by integrin alpha5beta1. This may relate to the involvement of CD9 in trophoblastic invasion.
CD9分子在人绒毛外滋养层细胞上表达，这些细胞在着床和胎盘形成过程中侵入子宫内膜。为了阐明CD9在滋养层细胞功能中的作用，我们使用免疫组织化学、蛋白质印迹法和逆转录聚合酶链反应（RT-PCR），研究了人滋养层样绒毛膜癌细胞系BeWo细胞中CD9蛋白和mRNA的表达。当用抗CD9单克隆抗体（mAb）培养BeWo细胞时，它们对细胞外基质的侵袭以剂量依赖的方式显著增强。细胞增殖和人绒毛膜促性腺激素的产生未受影响。另一方面，在存在部分阻断与细胞外基质相互作用的抗整合素α3、α5和β1抗体的情况下进行培养，会抑制BeWo细胞的侵袭。抗CD9单克隆抗体在抗整合素α3抗体存在时对BeWo细胞侵袭有刺激作用。相比之下，在抗整合素α5和β1抗体存在时它没有作用，而这两种抗体在BeWo细胞上也高度表达。这些发现表明，CD9具有与BeWo细胞侵袭特性相关的功能，这部分是由整合素α5β1介导的。这可能与CD9参与滋养层细胞侵袭有关。
