熱緊迫誘發之訊息傳導探討(I)

中山醫學大學機構典藏 CSMUIR > 口腔醫學院 > 牙醫學系暨碩士班 > 研究計劃 > Item 310902500/2878

Please use this identifier to cite or link to this item: https://ir.csmu.edu.tw:8080/ir/handle/310902500/2878

Title:	熱緊迫誘發之訊息傳導探討(I) Signaling in Heat Shock-Induced Apoptosis (I)
Authors:	周明勇 Chou, Ming-Yung
Contributors:	中山醫學院牙醫學系
Keywords:	過熱症;p53腫瘤抑制蛋白質;細胞凋亡 Hyperthermia;Tumor suppressor protein p53;Apoptosis;HSP70;PD98059
Date:	2006
Issue Date:	2010-11-25T03:41:37Z (UTC)
Abstract:	背景已知熱處理應用於腫瘤治療已數個世紀；然而，其作用機制仍莫衷一是。本實驗之目的乃在探討熱處理誘發之p53訊息傳導。材料與方法人類口腔癌細胞株OC2或其未經熱處理細胞之蛋白質溶液經不同的熱處理(37、39、41及43℃，三小時)。利用免疫轉漬技術檢測調控細胞週期的主要調控分子之表現。以免疫沉澱法分析蛋白質間之相互關係。HSP70之組態則以Non-denaturing電泳檢測。實驗結果經掃描後以NIH影像分析系統(NIH, Bethesda, MD, USA)分析。所有數據皆經ANOVA分析。結果熱處理誘發p53積存、p53於serine 15位置磷酸化且增加其下游標的基因p21、Bax╱Bcl-2之表現。p53之表現於熱處理後12小時達最高峰且至少延續達24小時。熱緊迫顯著增加p53與MDM2間之負回饋調控機制且增加ERKs的致活作用。PD98059，MEK (MAPK 或 ERK kinase)之特異抑制劑，顯著的強化了熱緊迫所誘發之p53磷酸化作用及HSP70的表現。HSP70係以單體存在且於熱處理後形成寡體。同時，HSP70複合物之表現例如p53、p21與Bax皆於熱處理後顯著增加。結論本研究顯示熱處理誘發之細胞週期停滯及細胞凋亡係藉由p53之訊息傳導。此外，熱處理誘發之p53訊息傳導與HSP70表現與ERKs之活性無關。 Background It is well known that heat treatment used in tumor therapy existed for centuries, however, the heat-induced signaling pathway remained less well characterization. The aim of this study is to investigate the regulation of heat shock-induced p53 signaling in OC2 cells, a human oral cancer cell line. Materials and methods OC2 cells or cell lysates were incubated at different temperatures (37, 39, 41 and 43.degree.C) for 3 hours. The Western blot was employed to quantify differences in master regulative molecule of cell cycle. Immunoprecipitation was used to detect the relationship among proteins. Non-denaturing electrophoresis was applied to detect the conformation of HSP70. Patterns of changes in expression were scanned and analyzed using the NIH image 1.56 software. All the data were analyzed by ANOVA. Results Heat shock induced the accumulation of p53, phosphorylation of p53 at serine 15 and increased the expression of its downstream target genes, p21 and Bax╱Bcl-2. The p53 signaling reached the peak at 12 hours and prolonged for at least 24 hours after heat treatment. Heat shock significantly induced the negative control mechanism between p53 and MDM2 60 kDa fragment, and trigged the activation of ERKs. PD98059, a specific inhibitor of MEK (MAPK or ERK kinase), markedly enhanced the heat shock-induced p53 phosphorylation and HSP70 expression. HSP70 existed in monomeric form and oligomerized after heat shock. In the meanwhile, the expression of HSP70 complexes such as p53, p21 and Bax were significantly induced by heat shock. Conclusion This study demonstrates that heat-induced cell cycle arrest and apoptosis are mediated by activation of p53 signaling. Furthermore, the p53 signaling and HSP70 expression induced by heat shock are independently of ERKs activation.
URI:	https://ir.csmu.edu.tw:8080/handle/310902500/2878
Appears in Collections:	[牙醫學系暨碩士班] 研究計劃

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