English  |  正體中文  |  简体中文  |  Items with full text/Total items : 43312/67235
Visitors : 2106490      Online Users : 3
RC Version 5.0 © Powered By DSPACE, MIT. Enhanced by NTU/NCHU Library IR team.
National Chung Hsing University Institutional Repository - NCHUIR > 生命科學院 > 生物醫學研究所 > 依資料類型分類 > 碩博士論文 >  探討tNOX透過調節β-catenin蛋白進而影響細胞週期的機制

Please use this identifier to cite or link to this item: http://nchuir.lib.nchu.edu.tw/handle/309270000/152672

標題: 探討tNOX透過調節β-catenin蛋白進而影響細胞週期的機制
The role of tumor-associated NADH oxidase (tNOX) in cell cycle regulation through modulation of β-catenin protein level
作者: 鄭小玲
Cheng, Hsiao-Ling
Contributors: 闕斌如
Pin-Ju Chueh
生物醫學研究所
關鍵字: tNOX;β-catenin;細胞週期
tNOX;β-catenin;cell cycle
日期: 2012
Issue Date: 2013-11-18 11:04:32 (UTC+8)
Publisher: 生物醫學研究所
摘要: Tumor-associated NADH oxidase (tNOX) 是一個存在於腫瘤細胞膜上的蛋白,其蛋白表現和腫瘤細胞的生長息息相關。在過去的研究中發現以 RNA干擾技術(RNAi)抑制 tNOX 表現會減弱 HeLa 細胞的生長與移動能力,而過度表現 tNOX 在非癌化細胞 (MCF-10A) 會導致細胞轉型且使具有侵犯性,這些研究皆指出 tNOX在腫瘤細胞的增生、移動和侵犯能力中扮演很重要的角色。
為了研究tNOX在細胞生長的功能,我們利用RNAi干擾技術抑制大腸直腸癌細胞 (HCT116) 中內生性tNOX的表現量,以探討tNOX對細胞生長的影響。實驗結果發現當tNOX表現量降低後,細胞生長以及與細胞週期相關的調控蛋白表現量會受到抑制,顯示出tNOX可能藉由調控細胞週期來影響腫瘤細胞的生長。進一步探討細胞週期調控蛋白的表現量變化結果中,發現Cyclin D1蛋白表現量在tNOX 表現抑制時會明顯跟著減少;而在過去研究中已知,Cyclin D1為Wnt/β-catenin 訊息傳遞路徑的下游target基因,所以我們接著分析β-catenin蛋白表現量和Wnt/β-catenin 路徑的轉錄活性在tNOX-knockdown下是否有影響,來探討tNOX是否是經由此路徑來影響Cyclin D1的表現。TOPflash reporter assay實驗結果發現,tNOX 表現量減少會抑制β-catenin轉錄活性,且使β-catenin和不活化態的GSK3β (p-GSK3β ) 表現受到抑制,顯示出tNOX可藉由調控GSK3β的活性來影響β-catenin 的降解。因此由以上實驗結果可知,tNOX 的缺乏在腫瘤細胞中會藉由影響 β-catenin蛋白功能來調控細胞週期蛋白Cyclin D1,進而延緩細胞的生長。
Tumor-associated NADH oxidase (tNOX) is a growth-related NADH oxidase, which expresses on the surface of transformed cells. Previous studies have reported that suppression of tNOX expression using RNA interference decreases HeLa cells proliferation and migration, whereas overexpression of tNOX in MCF-10A (non-cancer human mammary epithelia) cells leads to cell transformation and enhanced cell invasiveness, suggesting that tNOX plays a role in regulation of cells proliferation, migration and invasion.
To investigate the role of tNOX in cell proliferation, endogenous tNOX expression was inhibited by small interfering RNA in HCT116 cells. Our results showed that tNOX-knockdown inhibited cell proliferation and the expression of cell cycle regulators, suggesting that tNOX may play a role in regulating cell cycle and cell proliferation. Furthermore, western blot analyses demonstrated that Cyclin D1 expression was significantly reduced in tNOX-knockdowned HCT116 cells. Since Cyclin D1 is the target gene of Wnt/β-catenin signaling pathway, we further analyzed the protein level of β-catenin and its transcriptional activity in Wnt pathway to confirm the function of tNOX in regulating Cyclin D1 expression. Our results showed that tNOX-knockdowned cells exhibit decreased expression of β-catenin and p-GSK3β (inactive form), indicating that tNOX modulates β-catenin degradation possibly via GSK3β activation. Together, we propose that tNOX regulates cell cycle progression through modulating protein level of β-catenin leading to enhance cell growth in cancer cells.
Appears in Collections:[依資料類型分類] 碩博士論文

Files in This Item:

File SizeFormat
index.html0KbHTML120View/Open


 


學術資源

著作權聲明

本網站為收錄中興大學學術著作及學術產出,已積極向著作權人取得全文授權,並盡力防止侵害著作權人之權益。如仍發現本網站之數位內容有侵害著作權人權益情事者,請權利人通知本網站維護人員,將盡速為您處理。

本網站之數位內容為國立中興大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用。

聯絡網站維護人員:wyhuang@nchu.edu.tw,04-22840290 # 412。

DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU/NCHU Library IR team Copyright ©   - Feedback