2017-08-012024-05-14https://scholars.lib.ntu.edu.tw/handle/123456789/658010摘要：骨肉瘤是原發性高度惡性骨腫瘤，病情進展迅速易發生肺轉移，臨床上以化學治療或放射線治療的效果都不佳， 因此如何治療此癌症為重要課題。Thrombospondin 2 (TSP-2) 為Thrombospondins 家族的一員，在過去文獻發現Thrombospondin 2 的重要功能，如組織的修復及血管新生。在之前的研究報告中發現在前列腺癌、非小細胞肺癌及乳癌的病人中Thrombospondin2 有過度表現。但Thrombospondin 2 與骨肉瘤細胞轉移的關係並不清楚。本計畫將研究是否Thrombospondin 2 會促進骨肉瘤細胞分泌VCAM-1，進而促進骨肉瘤細胞轉移。而由初步的結果發現Thrombospondin 2 會增加骨肉瘤細胞分泌VCAM-1 的表現，另外給予Integrin 受體的中和抗體則可以抑制由Thrombospondin 2 所增加VCAM-1 的表現。因此，本計畫將研究是否Thrombospondin 2 /Integrin 交互作用參與在Thrombospondin 2 所增加VCAM-1 的表現。分析Thrombospondin 2/Integrin 經由那些訊息傳遞路徑參與在VCAM-1 的表現當中，應可以了解癌細胞轉移的過程也可以提供臨床上治療的可能性。由初步的結果也發現Thrombospondin 2會增加PLC, PKC 及c-Src 的磷酸化，另外一方面也發現給予骨肉瘤細胞PLC, PKC, c-Src 及NF-κB 抑制劑可以抑制由Thrombospondin 2 所增加的VCAM-1 的表現。因此，第二年期間將研究是PLC, PKC, c-Src 及NF-κB 訊息傳遞路徑是否參與在Thrombospondin 2 所增加VCAM-1 的表現當中。第三年的期間，將利用表現Thrombospondin 2 shRNA 的骨肉瘤細胞株U2OS/Thrombospondin2-shRNA，觀察其在動物模式中轉移的情況是否較U2OS/control-shRNA 少。這計畫的結果將可以了解Thrombospondin 2 是否調控骨肉瘤細胞轉移，可提供臨床上治療的可能性。<br> Abstract: Osteosarcoma is the most common primary malignancy of bone with a poor response tochemotherapy or radiation treatment, making the management of osteosarcomas a complicatedchallenge. It is characterized by a high malignant and metastatic potential. Thrombospondin 2 (TSP-2),from the thrombospondin family, which is involved in cancer cellular activities such as proliferation,cell motility, migration, adhesion and invasion abilities. It has been reported that the effect ofThrombospondin 2 is mediated via Integrin. However, the effects of Thrombospondin 2 on humanosteosarcoma cells are largely unknown. Our preliminary data showed that Thrombospondin 2increased the migration and expression of vascular cell adhesion molecule-1 (VCAM-1) in humanosteosarcoma cells. In addition, we also found that Thrombospondin 2 induced cell migration ismediated via Integrin. Involvement of VCAM-1 by Thrombospondin 2/Integrin interaction inThrombospondin 2-induced cell migration will be examined in this research planThe analysis of cell signaling for Thrombospondin 2 in osteosarcoma cells is crucial for thedevelopment of novel approaches for treatment of cancer metastasis. Our preliminary data also showedthat Thrombospondin 2 induced PLC, PKC and c-Src phosphorylation. In addition, Thrombospondin2-induced migration and VCAM-1 expression was antagonized by NF-κB inhibitors (PDTC and TPCK).Whether Integrin/PLC/PKC/c-Src and NF-κB signaling pathways are involved in Thrombospondin2-mediated migration activity and VCAM-1 expression in human osteosarcoma cells will be examinedin this research plan.In the third year, we will compare Thrombospondin 2 shRNA-transfected osteosarcoma cells(U2OS/Thrombospondin 2-shRNA) with control siRNA-transfected osteosarcoma cells(U2OS/control-shRNA) in pulmonary metastasis using an animal model. The present study willdelineate whether Thrombospondin 2 regulates the VCAM-1 expression in tumor cells and in tumormetastasis. These results will help us to understand the complicated processes of tumor metastasis, andbe beneficial for the development of effective anti-metastasis drugs.