肺癌是導致男性死亡的最常見原因以及是排在乳腺癌和結腸癌之後的導致女性死亡的第三大原因。雖然肺癌如此嚴重，但是如今治疗肺癌仍然是一个挑战。現今對肺癌的治療主要集中在化學治療和靶點藥物治療，但是由於這些治療有著很大的副作用和低治愈率，尋找其他的醫學替代方法十分迫切。甘草是其中最常用的中藥，它常常用作食品工業中的甜味劑。以往的研究表明，甘草具有多種的生物活性。但是甘草提取物對於肺癌的治療卻是十分匱乏的。 / 本論文主要目的是評價甘草提取物以及其中的有效成份對非小型肺癌細胞株A549 的影響，以及其作用的機理。我們的數據表明，甘草的乙酸乙酯（EAL）成份比甘草的乙醇提取物有著比較強的抑制癌細胞的作用。另外，對甘草的五個單體進行的測試中發現lico-3 是最具有抑制肺癌作用的。利用高效液相色譜法對甘草活性成份分析表明，lico-3 是EAL中的其中一個單體。 / 乳酸脫氫酶滲漏（LDH）的檢測結果以及异硫氰酸荧光素-碘化丙啶（FITC-PI）雙染的結果表明，EAL 能夠引起肺癌細胞的凋亡現象而非壞死現象。實驗結果表明由EAL引起的A549細胞凋亡是跟Bcl-2家族及Caspase家族有關係，同時EAL還能夠抑制Akt途徑從而導致細胞的死亡。 / 致肺癌細胞死亡的原因進行進一步研究表明，EAL還能夠引起抑制細胞週期的運作，停留在G2/M 時期。這可能是由於EAL引發了p53與p21的上調作用從而抑制了細胞的生長與增殖。 / 實驗結果說明了EAL引起的肺癌細胞株A549的凋亡作用是跟多重細胞通路有關， 同時表明了EAL是具有抗擊肺癌作用的潛能，能夠作為治療肺癌的藥物。 / Lung cancer is the most common cause of cancer death in men and third in women followed by breast cancer and colon cancer, yet treatment of lung cancer remains a challenge. Current treatments including chemotherapy and targeted drug treatment come with side-effects and low successful rate. Alternative medicine for treatment of lung cancer is warranted. Glycyrrhiza uralensis (Gan-Cao), commonly called “licorice, is one of the most commonly used herbs in traditional Chinese medicine (TCM). It is also used as flavoring and sweetening agents in many of food products. Previous studies have indicated that licorice exhibits a variety of biological activities. However, anticancer effects of licorice extract on lung cancer remain unclear. / In this study, we evaluated effects of licorice extract and its chemical components on human lung cancer cell line A549, and studied its mode of action. Our results showed the ethyl acetate fraction of licorice (EAL) was more effective in inhibition of A549 cell growth followed by ETL (IC₅₀: 50μg/mL). Moreover, among the five compounds tested, lico-3 was more potent compound. The HPLC analysis of the active fraction indicated that lico-3 was one of the compounds distributed in the EA fraction. / The results of LDH assay and FITC-PI co-staining method suggested low concentration of EAL can trigger apoptosis but not necrosis. The experimental findings show that EAL induce apoptosis in A549 cell lines involved in Bcl-2 family and caspase cascade. Also, EAL can arrest the Akt survival pathway in A549. Furthermore, the results indicate that EAL triggered G2/M phase arrest. The studies suggest EAL can up-regulate p53 and p21 to promote cell cycle arrest resulting in inhibition of proliferation. / Experimental results indicate that EAL is involved in multiple signal pathways to induce lung cancer cell death. The result suggests EAL is a potential candidate for lung cancer therapy. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zhou, Yanling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 99-110). / Abstracts in Chinese. / Abstract --- p.III / 論文摘要 --- p.V / Acknowledgement --- p.VII / List of Contents --- p.VIII / List of Figures --- p.X / List of Tables --- p.XI / List of Abbreviations --- p.XII / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Lung cancer --- p.1 / Chapter 1.1.1 --- Overview --- p.1 / Chapter 1.1.2 --- Risk factors --- p.2 / Chapter 1.1.3 --- Types of lung cancer --- p.4 / Chapter 1.1.4 --- Stages and treatment of lung cancer --- p.5 / Chapter 1.1.5 --- Chemotherapy for lung cancer treatment --- p.8 / Chapter 1.2 --- Traditional Chinese Medicines --- p.11 / Chapter 1.2.1 --- Overview --- p.11 / Chapter 1.2.2 --- Licorice --- p.14 / Chapter 1.2.3 --- Chemical study of licorice --- p.16 / Chapter 1.2.4 --- Pharmacological activities of licorice --- p.16 / Chapter 1.3 --- Molecular mechanism of apoptosis --- p.21 / Chapter 1.3.1 --- Overview --- p.21 / Chapter 1.3.2 --- Bcl2 family --- p.21 / Chapter 1.3.3 --- Caspase pathway --- p.23 / Chapter 1.3.4 --- Akt pathway --- p.24 / Chapter 1.3.5 --- p53 protein --- p.26 / Chapter 1.3.6 --- Apoptosis and cancer --- p.27 / Chapter 1.4 --- Cell cycle --- p.29 / Chapter 1.4.1 --- Overview --- p.29 / Chapter 1.4.2 --- Cell cycle and p53 --- p.29 / Chapter 1.4.3 --- Cell cycle and cancer --- p.30 / Chapter 1.5 --- Aims of study --- p.32 / Chapter Chapter 2 --- Materials and Methods --- p.33 / Chapter 2.1 --- Cell culture and treatment --- p.33 / Chapter 2.1.1 --- Cell line --- p.33 / Chapter 2.1.2 --- Chemicals and reagents --- p.34 / Chapter 2.1.3 --- Preparation of solutions --- p.34 / Chapter 2.2 --- Preparation of Licorice sample --- p.35 / Chapter 2.3 --- HPLC analysis --- p.35 / Chapter 2.3.1 --- Chemical and materials --- p.35 / Chapter 2.3.2 --- Instrumentation --- p.36 / Chapter 2.3.3 --- Preparation of Standard solutions --- p.36 / Chapter 2.3.4 --- Preparation of samples --- p.37 / Chapter 2.3.5 --- HPLC conditions --- p.37 / Chapter 2.3.6 --- Method validation --- p.37 / Chapter 2.4 --- Cell viable assay --- p.38 / Chapter 2.4.1 --- Samples preparation --- p.39 / Chapter 2.4.2 --- Procedure --- p.39 / Chapter 2.5 --- LDH assay --- p.40 / Chapter 2.5.1 --- Reagent preparation --- p.40 / Chapter 2.5.2 --- Procedure --- p.41 / Chapter 2.6 --- Annexin V assay --- p.41 / Chapter 2.6.1 --- Reagent --- p.42 / Chapter 2.6.2 --- Procedure --- p.42 / Chapter 2.7 --- Cell cycle study --- p.43 / Chapter 2.7.1 --- Chemicals and reagent --- p.43 / Chapter 2.7.2 --- Procedure --- p.44 / Chapter 2.8 --- Caspase3/7 Assay --- p.44 / Chapter 2.8.1 --- Reagent preparation --- p.45 / Chapter 2.8.2 --- Procedure --- p.46 / Chapter 2.9 --- Western blotting --- p.46 / Chapter 2.9.1 --- Reagent and antibodies --- p.46 / Chapter 2.9.2 --- Procedure --- p.50 / Chapter 2.9.3 --- Determination of protein concentration --- p.51 / Chapter 2.10 --- Data analysis --- p.51 / Chapter Chapter 3 --- Results --- p.52 / Chapter 3.1 --- Chromatographic conditions and HPLC identity conformation --- p.52 / Chapter 3.1.1 --- Linearity, limits of detection and quantification --- p.56 / Chapter 3.1.2 --- Reproducibility --- p.56 / Chapter 3.1.3 --- Analysis of ethyl acetate of licorice (EAL) using the validated method --- p.56 / Chapter 3.2 --- Licorice induces apoptosis in nonsmall cell lung carcinoma --- p.61 / Chapter 3.2.1 --- Cell viability assay --- p.61 / Chapter 3.2.2 --- LDH leakage assay --- p.71 / Chapter 3.2.3 --- Annexin V and PI staining --- p.73 / Chapter 3.3 --- Protein expression in EALinduced apoptotic cells --- p.75 / Chapter 3.3.1 --- Bcl2 family --- p.75 / Chapter 3.3.2 --- Activation of caspases by EAL treatment --- p.77 / Chapter 3.4 --- EAL could block Akt survival pathway --- p.79 / Chapter 3.5 --- EAL induces cell cycle arrest in nonsmall cell lung carcinoma --- p.83 / Chapter Chapter 4 --- Discussion --- p.85 / Chapter 4.1 --- Chemical analysis of licorice --- p.85 / Chapter 4.2 --- Licorice induced apoptosis but not necrosis on lung cancer cell A549 --- p.86 / Chapter 4.2.1 --- Licorice exhibits specific cytotoxicity to different cancer cells in vitro --- p.86 / Chapter 4.2.2 --- EAL induces cell death via apoptosis but not necrosis --- p.87 / Chapter 4.3 --- Growth inhibition by EAL inducing apoptosis --- p.89 / Chapter 4.3.1 --- EAL induces apoptotic cell death through modification of Bcl2 family --- p.89 / Chapter 4.3.2 --- EAL activate the caspase proteins --- p.90 / Chapter 4.4 --- Growth inhibition by EAL inducing survival pathway arrest --- p.92 / Chapter 4.5 --- Growth inhibition by EAL inducing cellcycle arrest --- p.94 / Chapter 4.6 --- General discussion --- p.96 / Reference --- p.99
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_328741 |
| Date | January 2012 |
| Contributors | Zhou, Yanling., Chinese University of Hong Kong Graduate School. Division of Life Sciences. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, bibliography |
| Format | electronic resource, electronic resource, remote, 1 online resource (xiii, 110 leaves) : ill. (some col.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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