Pentabromophenol (PBP)為溴化阻燃劑 (brominated flame retardants, BFRs)中常見的一種工業化合物，根據先前研究指出BFRs可能對人體與其他動物體具影響內分泌等危害。在此篇研究中我們發現PBP可以加速轉型生長因子-β (transforming growth factor-beta, TGF-β)受器在細胞膜內外的分布與降解，並藉此減弱細胞對TGF-β的反應。PBP可以抑制TGF-β所誘導發生的PAI-1報導基因活化與、Smad2/3的磷酸化與細胞移動，在A549 cells中也發現當TGF-β影響下游E-cadherin表現量減少與vimentin表現量增加的現象被抑制後，細胞受TGF-β刺激導致EMT發生的情況也會受到抑制。TGF-β能夠調節許多細胞反應，且與癌症發展的過程有關，在癌症晚期可促進癌細胞的增殖與轉移。在in vitro的實驗中發現PBP與TGF-β訊息傳遞路徑有關，而PBP為溴化阻燃劑其中的化合物，與polybrominated diphenyl ethers (PBDEs)的化合物也有相似的結構。因此，有鑑於TGF-β與許多人類疾病發展的關連性，日後也將深入探討PBP與溴化阻燃劑影響TGF-β訊息傳遞更精確的作用機制。

Pentabromophenol (PBP), a brominated flame retardant (BFR), is widely used in various consumer products. BFRs exert adverse health effects such as neurotoxic and endocrine-disrupting effects. In this study, we found that PBP suppressed TGF-β responsiveness by accelerating the turnover rate of TGF-β receptor. PBP suppressed TGF-β1-mediated cell migration, PAI-1 reporter gene activation and Smad2/3 activation in various type of cells, abolished TGF-β1-mediated repression of E-cadherin expression, as well as induction of vimentin expression along with Snail and Slug upregulation; thus, blocking the TGF-β1-mediated epithelial-to-mesenchymal transition (EMT) in A549 calls. TGF-β superfamily is a key player in the regulation of a wide variety of biological processes from development to pathogenesis including cell proliferation, migration, and the process of cancer development and progression. The in vitro results in this study provide a basis for studies of more detailed relationships between PBP and the modulation of TGF-β signaling. Because PBP is similar to other BFRs such as polybrominated diphenyl ethers (PBDEs), additional laboratory and mechanistic studies should be performed to examine BFRs as potential risk factors for tumorigenesis and other TGF-β-related diseases.

論文審定書+i
致謝 +ii
中文摘要+iii
Abstract+iv
縮寫表+x
前言 +1
實驗材料與方法+7
一、 細胞株+7
二、 細胞培養 (Cell Culture)+7
三、 質體備製 (Plasmids)+8
四、 真核細胞轉染 (Transfection)+9
五、 螢光素酶冷光活性分析 (Luciferase Activity Assay)+9
六、 西方墨點法 (Western Blotting)+10
七、 免疫螢光染色法 (Immunofluorescence)+11
八、 傷口癒合實驗 (Wound Healing Assay)+12
九、 細胞膜表面受器胞吞試驗 (Endocytosis Assay)+12
十、 RNA抽取 (RNA Isolation)與反轉錄PCR (Reverse Transcription-PCR, RT-PCR)+14
十一、 聚合酶連鎖反應 (Polymerase Chain Reaction, PCR)與洋菜膠電泳法 (Agarose gel Electrophoresis)+15
十二、 蔗糖濃度梯度離心 (Sucrose Gradient Centrifugation)+16
十三、 細胞存活率分析 (MTT Assay)+17
十四、 免疫沉澱 (Immunoprecipitation)+17
十五、 統計方法+18
結果+19
PBP抑制TGF-β所誘導Smad蛋白質磷酸化與下游相關promoter活性+19
PBP抑制TGF-β所誘導EMT反應發生+20
PBP抑制TGF-β所誘導的細胞移動+21
PBP加速TβRⅡ內化到細胞中並促其迅速被降解+22
PBP可增強藉caveolea所媒介之胞吞作用將TβRⅡ內化到細胞中並降解+23
PBP可以影響TβRⅡ在lipid raft與non-lipid raft的分布+25
討論 +53
參考文獻+56
附錄+62

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