探討以Quercetin及Luteolin對尼古丁誘導乳癌細胞株 ( MDA MB - 231 ) 增生的影響

Effects of Quercetin and Luteolin on the Nicotine-induced Proliferation in Breast Cancer Cell Line ( MDA MB – 231 )

劉惠菁(Hui-Ching Liu)

指導教授 ： 何元順

共同指導教授 ： 許重輝(Chung-Huei Hsu)

臺北醫學大學/醫學院/醫學科學研究所/碩士(2008年)

摘要

中文摘要
( Abstract in Chinese )

許多文獻指出吸煙是引發肺癌的重要因子之一。在本實驗室之前的研究發現尼古丁受體 α9在尼古丁所誘發的乳癌中可能扮演著重要的角色。本研究主要目的是探討乳癌、尼古丁、以及天然化合物之間的關連性。MDA MB-231乳癌細胞株是雌性激素接受體陰性。而純化天然化合物 Quercetin 及 Luteolin 存在於一般日常生活常食用的蔬菜水果中，可抑制癌症細胞生長及許多訊息傳遞路徑的蛋白質表現。因此在本實驗中欲觀察在MDA MB-231給予Quercetin 及 Luteolin後是否能抑制尼古丁所誘發的尼古丁受體 α9表現量增加。
在MDA MB-231細胞株中， Nicotine隨著劑量增加會促使其增生，並使得其nAchR α9 mRNA及蛋白質表現量增加。而Nicotine影響nAchR α9 mRNA的表現會較蛋白質表現時間短。在MTT assay，或是RT-PCR及Western blot的實驗中，合併使用天然化合物 Quercetin 及 Luteolin，MDA MB-231細胞株的生長、nAchR α9 mRNA及蛋白質表現量均較單獨使用抑制效果為佳，儘管加入Nicotine也是如此。而在訊息傳遞方面，合併使用效果也較單獨使用更可以抑制Nicotine引起與PI3K/Akt傳遞路徑、MAPK傳遞路徑相關的蛋白質表現量。另外在細胞週期方面，Quercetin 及 Luteolin 能抑制細胞週期G1/S的調控蛋白cyclin D1的表現量，單獨使用或合併使用都有抑制效果，但兩者差別並不明顯。
藉由 Luciferase assay 實驗中發現 Quercetin 及 Luteolin 可抑制因為Nicotine 所誘導的nAchR α9 promoter活性。而模擬活體實驗的Soft agar assay中也可以觀察到 Quercetin 及 Luteolin 在單獨或混合使用皆可抑制MDA MB-231細胞株形成colony的能力。

關鍵字

尼古丁 ； 槲黃素 ； 木犀草素 ； 乳癌 ； 尼古丁受體 α9 ； 乳癌細胞株MDA MB-231

並列摘要

Abstract
(Abstract in English)

Previous studies showed that tobacco-smoking is a well understanding carcinogenic factor that promotes the lung cancer formation. Previous reports had demonstrated that nicotine receptor α9 might play an important role in nicotine-induced breast cancer. The purpose of this study will figure out the correlation of breast cancer, nicotine, and natural compounds. MDA MB-231 is estrogen receptor negative breast cancer cell line. Quercetin and Luteolin are purified from natural fruits and vegetables. Both of them can suppress cancer cell growth and inhibit protein expression of signaling pathways. In this study, after adding Quercetin or/and Luteolin in MDA MB-231, I further investigated whether these compounds were involved in the inhibition of the over expression of nicotine-induced nicotine receptors.
In MDA MB-231 cell line, nicotine can induce cell growth, and expression of nAchR α9 mRNA and protein. Nicotine influences the mRNA level of nAchR α9 faster than the protein level. In MTT assay, RT-PCR and Western blot assay, the data showed that Quercetin or/and Luteolin can suppress cell growth, mRNA and protein expression of nAChR α9, with or without nicotine. In signal transduction, Quercetin or/and Luteolin can inhibit the protein expression of nicotine-induced PI3K/Akt and MAPK pathway, but inhibition of combination group is not significantly. Quercetin or/and Luteolin also can inhibit Cyclin D1 in cell cycle proteins, but inhibition of combination group is not significantly.
In Luciferase assay, Quercetin and Luteolin could inhibit nAchR α9 promoter activity through Nicotine induction. Soft agar assay showed that Quercetin or/and Luteolin also could supperess the colony formulation of MDA MB-231.

並列關鍵字

nicotine ； quercetin ； luteolin ； breast cancer ； nAchR α9 ； MDA MB-231

參考文獻

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