- 學位論文
Tiplaxtinin 對於口腔癌症幹細胞的影響
The effect of tiplaxtinin in the properties of cancer stem cells of oral carcinoma
摘要
癌症幹細胞是癌細胞中一些具有類似幹細胞特性的一群癌細胞。它具有自我更新，抵抗化學治療、放射線治療，以及有轉移的能力，在許多種癌症細胞中，包含頭頸癌，已經證實癌症幹細胞的存在。口腔癌是頭頸癌的一種，它可以生長在口腔的任何位置，在台灣男性中為排名第四位的癌症。第一型纖維蛋白溶酶原活化抑制物是屬於血栓形成的一個相關因子，其作用為不可逆地抑制組織纖維蛋白溶酶原活化物 (Tissue plasminogen activator，tPA) 和尿激酶型纖溶酶原活化物 (Urokinase - type plasminogen activator，uPA) 活化纖維蛋白溶酶原的活性。在口腔癌的早期階段也證實第一型纖維蛋白溶酶原活化抑制物的表現量會增加，但其在口腔癌幹細胞的作用尚不清楚。本研究首先使用第一型纖維蛋白溶酶原活化抑制物的抑制劑 (Tiplaxtinin，又稱作PAI-039) 試圖了解第一型纖維蛋白溶酶原活化抑制物在口腔癌症幹細胞的角色。PAI-039對口腔癌細胞具有細胞毒性，對於三種口腔癌細胞株 (SAS、GNM、OC3) 的IC50濃度分別為81 μM、145 μM、75 μM。利用非貼覆性球體培養實驗，發現PAI-039能夠以濃度依賴性的方式抑制三種口腔癌症細胞中口腔癌幹細胞的自我更新。使用RNA干擾技術，降低SAS細胞內PAI-1的表現，發現也可以抑制SAS細胞的自我更新。藉由西方點墨法，觀察到PAI-039能以濃度依賴性的方式抑制三種口腔癌細胞株中的SOX2和Nanog蛋白質表現量。以定量聚合脢連鎖反應實驗，也證實PAI-039能以濃度依賴性方式抑制SAS細胞內SOX2與Nanog的mRNA表現。因此我們認為第一型纖維蛋白溶酶原活化抑制物的抑制劑，PAI-039，能透過抑制SOX2與Nanog的表現，進而抑制口腔癌幹細胞的自我更新。
並列摘要
Cancer stem cells (CSCs) are described as a small population of cells residing within a tumor which are able to have stem-like properties such as self-renew, resistance to conventional chemo/radiation therapy and metastasis. The existence of CSCs has been described in a variety of solid tumors including head and neck cancer. Oral cancer is a subtype of head and neck cancer which represents any cancerous tissue growth located in the oral cavity. Plasminogen activator inhibitor-1 (PAI-1), which belongs to thrombosis-related factors, acts as an irreversible inhibitor of Tissue plasminogen activator (tPA) and Urokinase-type plasminogen activator (u-PA) to inhibit the activation of plasminogen. PAI-1 has been demonstrated to be increased in early stage of oral cancer but its role in oral cancer stem cells remains unknown. In this study, we first used Tiplaxtinin (PAI-039), a PAI-1 inhibitor, to examine its cytotoxicity to oral cancer cells. The IC50 concentration of PAI-039 to three oral cancer cell lines (SAS, GNM or OC3) was 81 uM, 145 uM or 75 uM, respectively. Using sphere formation assay, PAI-039 inhibited self-renewal capability of oral cancer stem cells within SAS, GNM and OC3 cells in a dose dependent manner. By siRNA knockdown, decreased PAI-1 expression also inhibited self-renewal of SAS cells. By western blot assay, PAI-039 could decrease the expression of SOX2 and Nanog in oral cancer stem cells in dose dependent manner. By quantitative real time polymerase chain reaction method, PAI-039 could decrease SOX2 and Nanog mRNA expression of oral cancer stem cells within SAS cells in dose dependent manner. In conclusion, inhibition of PAI-1 activity by PAI-039 could suppress cancer stem cell activity within SAS, GNM and OC3 oral cancer cells through down regulation of Sox2 and Nanog.