- 學位論文
鈣離子及黏著分子的調控對癌細胞遷移之影響
Interactions between Ca2+ and cell adhesion molecules during cancer cell migration
摘要
細胞內鈣離子參與調控細胞增生、細胞內訊息傳遞以及細胞遷移，近幾年研究指出當細胞內鈣離子訊息傳遞失調時，會導致癌症的生成及轉移，而對於細胞內鈣離子的調控以及維持恆定性，其中store-operated Ca2+ entry (SOCE)扮演著重要調節腳色，然而對於SOCE是促進還是抑制癌細胞遷移仍然眾說紛紜，目前認為SOCE可能與粘著斑 (focal adhesion, FA)形成有關，就此影響細胞遷移能力。在先前研究發現讓癌細胞貼附於不同程度的細胞外基質上並抑制SOCE，在細胞移動速度上卻有著相反的結果，暗示著粘著斑與SOCE活性之間有著重要的平衡調控癌細胞遷移。 為了驗證上述想法我們藉由粘著斑與SOCE建立了細胞遷移速度的數學模型，並使用口腔鱗狀上皮癌細胞株SAS檢測模型的可靠性。具體做法為偵測SAS含有黏附因子及鈣離子調控蛋白的量，並應用遺傳學的方式使細胞過度表現或減少Paxillin (focal adhesion complex成員)及STIM1，或是用藥理學工具BTP2抑制SOCE情況下對SAS細胞遷移的影響，確立SAS在我們所建立的熱度圖上的位點。接著藉由同時過度表現不同程度的PXN及STIM1做細胞遷移實驗，追蹤每顆細胞個別帶有的PXN及STIM1量後畫出熱度圖，發現與我們所假設的模型相似，因此粘著斑與SOCE之間的平衡對癌細胞的遷移是重要的。 未來我們將(1)繼續驗證及修正此數學模型，並且能夠將此模型套用在其他癌細胞上，(2)透過高解析度活細胞影像平台，更了解癌細胞遷移之間SOCE及粘著斑平衡調控的機制，(3)將此模型進一步在動物及臨床上驗證，藉此預測癌症病人預後及抑制癌細胞轉移。
並列摘要
Ca2+ signaling regulates many cellular functions such as cell cycle progression and cell migration, which is also critical for cancer metastasis. Proper Ca2+ signaling requires store-operated Ca2+ entry (SOCE). However, there are controversies that SOCE may enhance or impede cancer cell migration from different literature reports. Recent studies suggested that SOCE-mediated Ca2+ signaling may modulate cell migration through interacting with focal adhesion (FA) complexes. Our previous study also showed that different cell-matrix adhesion strength and SOCE activities might differentially affect motility. These results indicate that FA and SOCE activities affect cancer cell migration in an integrated way. To validate our speculations, we established a cell migration prediction heatmap using SOCE activities and focal adhesions. To verify our model, we suppressed or overexpressed Paxillin (a member of the focal adhesion complex) in SAS, an oral squamous cell carcinoma cell line. Also, we manipulated SOCE by altering STIM1 or treating the cells with BTP2, a SOCE inhibitor in SAS. Motilities of cells with above manipulations were measured to determine the original position of wild type SAS cell line on the heatmap. We then made each of the SAS cells expressing different levels of STIM1 and PXN, and measured their motilities in cell migration assays. These cells showed different migration activities as predicted in our prediction map. Therefore, our results support that proper balance between SOCE and focal adhesion is important for cancer cell migration. In the future, we will (1) further validate and revise our model in other types of cancer cells, (2) use high resolution live-cell imaging platform to understand the mechanism how SOCE and FA regulate cancer cell migration, and (3) apply this model in animal experiments and clinical samples. With these approaches, this model will enable us to predict cancer prognosis precisely and to treat cancer metastasis efficiently.
參考文獻
延伸閱讀
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