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http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/71692
標題: | 以動態觀察探討微環境的變化對頭頸癌腫瘤衛星現象的影響 Dynamic investigation of the impact of microenvironmental changes on the tumor satellite formation of head and neck cancer |
作者: | Chun-Nan Chen 陳俊男 |
指導教授: | 楊宗霖(Tsung-Lin Yang),陳佑宗(You-Tzung Chen) |
關鍵字: | 頭頸癌,腫瘤衛星現象,體外三維膠原蛋白模型,E-cadherin內移,侵襲性偽足,胞外低鈣培養,氯化鈷, Head and neck cancer,tumor satellite phenomenon,in vitro 3D collagen model,E-cadherin internalization,invadopodia,low calcium,CoCl2, |
出版年 : | 2019 |
學位: | 博士 |
摘要: | 背景:頭頸癌 (Head and neck squamous cell carcinoma, HNSCC) 是有高發生率且預後不良的癌症。高侵襲性之頭頸癌會在腫瘤前緣發生腫瘤衛星現象(tumor satellite phenomena),而這現象與上皮間質轉換 (epithelial-mesenchymal transition, EMT)、局部侵犯及遠端轉移有高度相關性。受限於過去僅能藉由靜態二維病理切片檢體進行分析,腫瘤衛星現象的動態轉換過程及其因子一直無法進行評估及研究,因此建立體外頭頸癌模型來重現此現象對於相關研究十分重要。
材料及方法:在本研究中,我們利用膠原蛋白支架建立了一個體外三維腫瘤模型系統,成功培養3 種侵犯能力不同之頭頸癌細胞株 (SCC25, OECM1, SAS) ,並藉由改變細胞外環境“胞外低鈣 (low calcium, LowCa)”及細胞內環境“以氯化鈷提昇胞內HIF-1a”來誘發出腫瘤衛星現象。在這個過程中,我們利用顯微曠時攝影即時記錄其從原發腫瘤 (main tumor) 至腫瘤邊緣產生衛星細胞 (Satellite cells) 的動態變化。另外,也將此立體模型進行系列切片以進行相關因子的免疫螢光染色以檢驗其與腫瘤衛星現象的相關性。最後再針對手術檢體的腫瘤及衛星細胞進行同樣的免疫螢光染色,以確認此體外三維腫瘤模型與實際腫瘤的腫瘤衛星現象相關因子表現是否一致。 結果:有別於傳統病理檢查僅能達成的單一時間點之靜態分析,本研究所發展的體外三維膠原蛋白模型可成功培養腫瘤細胞,以進行動態記錄並確認辨別出腫瘤本體 (main tumor) 及後續產生的衛星細胞 (satellite cells)。 改變細胞外環境 (胞外低鈣):這個3維膠原蛋白模型透過低鈣所形成的腫瘤衛星現象,經由分析結果發現,有別於傳統的EMT定義 (即E-cadherin 消失及 Vimentin 表現增加),其腫瘤衛星細胞並未有傳統EMT 的變化,而是透過E-cadherin 結構與功能之重組 (E-cadherin internalization)、及Vimentin 聚集與侵襲性偽足之形成 (Invadopodia formation) 等重要因子誘導腫瘤衛星現象發生,進而產生局部侵犯及移行之現象。在這些重要因子之變化也同時在頭頸癌病人之手術檢體中獲得進一步驗証。 改變細胞內環境(氯化鈷以提昇胞內HIF-1a):透過氯化鈷所產生的衛星細胞,除了呈現上述E-cadherin 結構與功能之重組及Vimentin 聚集與侵襲性偽足之形成外,也在細胞核內高度表現HIF-1a及PHD2。更特別的是,氯化鈷所產生的這些改變,只有在侵犯能力較低的SCC25 細胞株才能顯著誘發腫瘤衛星現象。這些重要因子之變化也同時在頭頸癌病人之手術檢體中獲得進一步驗証。 結論:在本研究中,我們透過體外三維膠原蛋白模型的應用,發現腫瘤衛星現象是透過E-cadherin 結構與功能之重組、侵襲性偽足之形成及細胞核內高度表現HIF-1a及PHD2所產生,並非僅是傳統定義的上皮間質轉換,也進一步証明利用膠原蛋白模型進行動態分析的重要性。這方法未來也可以應用於探討癌細胞轉變與藥物發展的機制。 Background: Head and neck cancer is a cancer with high incidence and poor prognosis. Head and neck cancer with high invasive capacity will have tumor satellite formation at the invasive front. Such phenomenon was closely related to epithelial-mesenchymal transition (EMT), local invasion, and distant metastasis. Limited by analysis of this phenomenon only depending on static pathological slides, the dynamic process of tumor satellite phenomenon and associated factors were not evaluated and investigated in the past. Consequently, establishment of an in vitro 3D model for head and neck cancer to recapitulate this phenomenon is very important for advanced research. Materials and Methods: In this study, we used collagen scaffolds to establish an in vitro 3D tumor model to cultivate 3 head and neck cancer cell lines. These 3 cell lines, SCC25, OECM1, and SAS, had their distinct invasive capacities. Two approaches were used to induce tumor satellites, including changing extracellular environments by low calcium concentration and changing intracellular environments (elevated HIF-1a) by CoCl2. We used microscopic time-lapse recording to observe the dynamic process from only main tumor to formation of satellite cells at tumor margin. In addition, serial sections of this 3D model were also performed to analyze the associated factors by immunofluorescent staining and to reveal their relationship with tumor satellite phenomenon. Finally, we validated the results with those in the surgical specimens to confirm the clinical value of this 3D model. Results: Unlike static analysis of traditional pathological slides, this study developed an in vitro 3D collagen model, which cultivated head and neck cancer cells and was dynamically recorded for the process of tumor satellite formation from main tumor. For changing extracellular environments (extracellular low calcium concentration): The analysis showed the formation of satellite cells was achieved through E-cadherin remodeling and internalization, vimentin clustering and invadopodia formation, but not through traditional EMT. These factors were validated in the surgical specimens of head and neck cancer. For changing intracellular environments (CoCl2 to elevate intracellular HIF-1a): In addition to E-cadherin internalization and invadopodia formation, nuclear expression of HIF-1a and PHD2 was also noted in the satellite cells. Most important, the effects of CoCl2 in tumor satellite induction were only applicable on the SCC25 with less invasive capacity. These factors were also validated in the surgical specimens of head and neck cancer. Conclusion: In this study, we established an in vitro 3D collagen model and successfully induced tumor satellite phenomenon. The key factors related to tumor satellite phenomenon were E-cadherin remodeling and internalization, invadopodia formation and nuclear expression of HIF-1a and PHD2, but not traditional EMT. The in vitro 3D collagen model is important for dynamic analysis of cancer cell behaviors and may be helpful on the way of new drug development. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/71692 |
DOI: | 10.6342/NTU201900036 |
全文授權: | 有償授權 |
顯示於系所單位: | 臨床醫學研究所 |
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