CD93 (C1qRp)是一個表現在骨髓系統細胞、微膠細胞、內皮細胞以及初級幹細胞表面的高度醣基化蛋白質。CD93會去參與C1q調節促進吞嗜作用。然而，其它文獻提出在體外的吞嗜作用上，CD93並不是必須的。CD93蛋白的細胞外區域，含有醣類辨認區，其可與醣類結合並調節細胞吸附與移動能力。因此本論文的目的在研究CD93在細胞移行弁鄐W的角色。首先將全長的CD93與除去C端的片段構築在pEGFP-N1載體中，將其轉染至A2058黑色素腫瘤細胞並挑選出穩定表現的細胞株。使用wound healing assay和Boyden chamber invasion assay，我們證明A2058-CD93細胞和A2058-CD93ΔC細胞爬行能力和侵襲力都比控制組A2058-GFP細胞增加。我們也發現A2058-CD93細胞爬行比A2058-GFP更具有方向性。此結果顯示CD93蛋白可以調節細胞移行的方向性。另外，我們顯示在A2058-CD93細胞的MMP-2/9活性會比A2058-GFP高。Real-time PCR的實驗也證明MMP-2/9 mRNA的表現在A2058-CD93細胞比A2058-GFP高。我們亦證明A2058-CD93細胞的Rac-1活性比控制組細胞增加。此結果提出了CD93對細胞爬行及侵襲的影響可能是透過Rac-1的訊息傳遞路徑以及MMP-2/9的活化。 CD93 (C1qRp) is a cell surface glycoprotein predominantly expressed on myeloid lineage cells, microglia cells, endothelial cells and early stem cell precursors. CD93 was considered to be involved in the C1q-mediated enhancement of phagocytosis. However, other reports suggested that CD93 was not required for enhancing phagocytosis in vitro. The extracellular domain of CD93 contains a carbohydrate-recognition domain, which is known as a bind site for carbohydrates and to mediate cell adhesion and locomotion. Thus the specific aim of this study is to investigate the role of CD93 on cell migration. We established stably expressed green fluorescent protein-tagged CD93 or cytoplasmic domain–deleted CD93 (CD93(ΔC)) transfectants in A2058 melanoma. Using in vitro wound healing assay and Boyden chamber invasion assay, we demonstrated that the migration and invasion of A2058-CD93 cells and A2058-CD93ΔC cells were increased than that of control A2058-GFP cells. We also found that A2058-CD93 cells migrated directionality while A2058-GFP cells migrated haphazardly. The results suggested that CD93 could mediate the directional cell migration. In addition, we showed that The MMP-2/9 activities in the conditioned medium from A2058-CD93 cells were elevated that that from A2058-GFP cells. The real-time PCR experiment also demonstrated that the expressions of MMP-2/9 mRNA in A2058-CD93 cells were increased than that in A2058-GFP cells. Moreover, we demonstrated that the Rac-1 activity of A2058-CD93 cells was increased that of control cells. These results suggested that the effect of CD93 on mediating cell migration and invasion might be through the Rac-1 pathway and the induction of MMP-2/9 activities.
