腫瘤內皮標誌一(CD248)表現於纖維母細胞和周細胞，為第一型穿膜醣蛋白。先前的報導指出CD248會促進腫瘤的發展。胰腺星形細胞是胰臟中一種類纖維母細胞，在胰臟癌中扮演著重要角色。然而CD248是否參與胰腺星形細胞與胰臟癌細胞間的訊號溝通仍未明。由生物資訊得知CD248表現量較少的胰臟癌病患，有比較好的預後。我們還發現CD248表現於胰腺星形細胞而不是胰臟癌細胞。弱化CD248基因(CD248 Knockdown)後的纖維母細胞，其細胞培養液可以減少其促進惡性胰臟癌細胞增生與爬行的能力。直接給予重組CD248蛋白，會增強胰臟癌細胞的增生、爬行及侵襲的能力。此外我們發現重組CD248蛋白和血小板衍生生長因子受體β（Platelet-derived growth factor receptors beta，PDGFRβ）有交互作用，並且增強其下游的ERK的訊號傳遞。另外我們證明原位胰臟癌動物實驗中，給予重組CD248蛋白會增強胰臟癌細胞的轉移程度。總結我們認為腫瘤內皮標誌一蛋白會參與在胰腺星形細胞與胰臟癌細胞間的訊號溝通裡，抑制腫瘤內皮標誌一有助於減少胰臟癌的惡性轉移。

Tumor endothelial marker 1 (TEM1), also called endosialin or CD248, is correlated with cancer-associated fibroblasts. Pancreatic stellate cells (PSCs), the fibroblast-like cells in the pancreas, are critical to tumor microenvironment, which stimulates local tumor growth and distant metastasis. Whether soluble CD248 participates in PSCs and pancreatic cancer cells is still elusive. Here we used MTT assay and transwell migration assay to observe the tumor biological functions of CD248. We showed that CD248 could promotes proliferation and migration via binding to Platelet-derived growth factor receptors beta (PDGFRβ). Moreover, intraperitoneal injection of rCD248 could enhance the growth and metastasis of pancreatic cancer in orthotopic pancreatic tumor mouse model. These results suggest that CD248 is essential for pancreatic cancer progression.

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