2017-01-012024-05-14https://scholars.lib.ntu.edu.tw/handle/123456789/655437摘要：腺嘌呤核苷二磷酸核醣化因子蛋白(ADP-ribosylation factors (ARFs)) 屬於Ras 小GTP 酶蛋白家族，調控細胞膜運輸、維持胞器健全、 細胞膜脂質修飾和細胞骨架動力。ARF 家族的蛋白，以及其上游調控分子都被認為和多種不同種類的癌症生成有關，如神經膠質瘤、黑色素瘤、肝癌、前列腺癌、乳癌及大腸癌。我們研究顯示 ARF-like GTPases 包括三個相似分子 ARL4A，ARL4C，和ARL4D，表現在特定分化時期、胚胎發育期和組織中。我們發現 ARL4D 可藉由Cytohesin-2/ARNO 路徑，造成ARF6 活化來調控細胞骨架的重組。我們最近研究證實 ARL4A 經由直接調控高基式體及其在高基式體上的蛋白質進而影響細胞囊泡傳輸及細胞骨架重組。我們最新的研究結果發現了數個ARL4 結合蛋白，功能上和表皮細胞癌化有關，包含胞膜接受器、磷酸酶、細胞骨架蛋白和肌動蛋白結合蛋白、囊泡分類蛋白、細胞黏附分子，甚至包含其他 smallGTPases 的調控者。現階段實驗我們進一步要證明，什麼上游訊息足以活化ARL4 家族蛋白和其下游，並參與囊泡傳輸和細胞骨架的調控，以及他們在細胞膜接受器訊息傳遞、細胞遷移、細胞侵襲和癌症生成的重要角色。我們同時要在ARL4 GTPases 訊息路徑尋找新的臨床應用，利用深入了解ARL4 GTPases 訊息路徑的分子機制。 更重要的是，期能發現新的抗癌藥物標的 ，可能提供未來癌症治療的新方向。在這個計畫中我們的研究目標是：1. 研究 ARL4 GTPases 參與在癌症發生過程的分子機制。2. 尋找及探討調控ARL4 GTPases 活性的因子。3. 研究上游調控ARL4 GTPases 活化的訊息路徑及在癌症發生過程的調控機制。本研究計畫具有發展的重要性：1.瞭解活化的 ARL4 GTPases 在囊泡傳輸及細胞骨架重組的調控機制；幫助了解和執行 ARL4 GTPases 和其結合蛋白調控因子在癌症發生過程的生化和基因操控應用。本研究幫助發展創新的 ARL4 GTPases 訊息調空分子，有益於理解癌症的病理發展，創新生物標記和治療藥物標的發展，獲得對於癌症有效的診斷方式和治療方法。<br> Abstract: The ADP-ribosylation factors (ARFs), members of Ras family small GTPases, are involved in membrane transport, maintenance of organelle integrity, embrane lipid modification, andcytoskeletal dynamics. Members of ARF family as well as their regulators have been shownto associate with the formation of different type of cancers, such as glioma, melanoma,hepatocellular carcinoma, prostate cancer, breast cancer, and colorectal cancer. We haveidentified and characterized a group of the ARF family members, ARL4s (ARL4A, ARL4C,and ARL4D) and showed their expression is differentiationdependent, developmentallyregulated, and tissue specific. Our recent study showed that ARL4 acts as a novel upstreamregulator of cytohesin-2/ARNO to promote ARF6 activation and modulate actin remodelingand cell migration. We also demonstrated that ARL4A modulate both vesicular traffickingand cytoskeletal dynamics through direct interaction with the Golgi and a Golgi associatedprotein. We recently identified several ARL4-interacting proteins, whose functions have beenassociated with epithelial cell carcinogenesis, ranging from membrane receptors, kinases,microtubule- and actinbinding proteins, endosomal sorting proteins, adhesion molecules, toregulators of other small GTPases. Importantly, our current study found that ARL4A becameactive in response to fibronectin and/or serum stimuli, leading to induce cell spreading,membrane ruffling, and orphological changes. In this proposal, we would like to demonstratethat ARL4 family proteins are activated by yet to be identified signal(s) to recruit theireffectors to participate in vesicular trafficking and cytoskeletal regulation, and thereby playimportant roles in receptor-mediated cell signalling, cell migration andinvasion, and/or tumorigenesis. We also aim to reveal the implications of ARL4 GTPasesignaling in human diseases, which will provide a molecular basis to explore their utilities asdiagnostic and/or therapeutic targets for related cancer. The following studies are our goalsin this proposal:1. To elucidate the underlying mechanisms of how ARL4 GTPases modulate oncogenicprocess.2. To identify and characterize regulators for ARL4 GTPases activation.3. To determine upstream signaling pathways modulating ARL4-regulated oncogenicprocess.The proposed research is significant in that: 1) it will contribute to our understanding of theregulation of vesicular trafficking and cytoskeleton reorganization by ARL4 small GTPases intumor development; 2) it will provide the knowledge and the methods for biochemical andgenetic manipulation of the interaction of ARL4s and their associated molecules orregulators in tumor development and progression; and 3) the information gained will lead tothe discovery of novel ARL4s signaling molecules contributing to the pathogenesis ofcancer, facilitate the identification of novel biomarkers and drug targets, yielding moreeffective diagnostic and treatment strategies for cancers.鳥苷酸蛋白酶囊泡傳運細胞骨架重組癌症生成細胞移動GTPasevesicular traffickingcytoskeletal dynamicsoncogenesismigration