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

In conclusion, our study has demonstrated that TGZ, a synthetic PPARgamma ligand, inhibits lung cancer cells growth through cell-cycle arrest, increased cell differentiation and induction of apoptosis. In this pathway, the activation of ERK by TGZ plays a central role in promoting apoptosis, which appears to be mediated via a mitochondria-related mechanism and functions in a PPARgamma-dependent manner. The interaction between PPARgamma and ERK may create an auto-regulatory and positive feedback loop to enhance the effect of ERK whereas the activation of Akt may generate a negative regulation to control the degree of apoptosis occurred in lung cancer cells. TGZ may counteract NNK function to inhibit lung cancer cell growth in the PPARgamma-dependent manner. / Lung cancer is the world's leading cause of cancer death. Currently there is not an acceptable adjuvant or palliative treatment modalities that have been conclusively shown to prolong survival in lung cancer. Therefore, translational research to improve outcomes with this disease is critical. Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a member of the nuclear hormone receptor superfamily of ligand-activated transcription. PPARgamma ligands have been demonstrated to inhibit growth of cancer cells. The role of the PPARgamma in cell differentiation, cell cycle arrest and apoptosis has attracted increasing attention. Our study focused on the role of PPARgamma and its ligand troglitazone (TGZ) in the cell death of human lung cancer and the interaction between PPARgamma system and 4-(N-Methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a major tobacco-specific carcinogen. / The epidemic of lung cancer is directly attributable to cigarette. However, it is still not completely known the molecular pathway of cigarette smoking in the pathogenesis of lung cancer. Among the carcinogenoic chemicals of cigarette smoking, 4-(N-Methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is the most potent, which induces lung cancer in all animal species tested. Unlike PPARgamma ligands, NNK can promote cell proliferationa and growth. It is interesting to know whether PPARgamma ligands can inhibit the growth-promoting function of NNK. To address this question, we used NCI-H23 lung cancer cells as the model to study how TGZ influenced the function of NNK. Results showed that NNK stimulated cell proliferation, induced the DNA binding activity of nuclear factor-kappaB (NF-kappaB), down-regulated Bad expression, and up-regulated PPARgamma protein expressions. Inhibition of NF-kappaB nuclear translocation led to the suppression of NNK-mediated Bad expression, indicating that NNK may regulate Bad expression through the activation of NF-kappaB. TGZ significantly inhibited cell proliferation induced by NNK. Though TGZ did not affect nuclear factor-kappaB (NF-kappaB) activity, it up-regulated Bad expression. Taken together, TGZ can efficiently inhibit the proliferation of lung cancer cells induced by NNK via Bad- and PPARgamma- related pathways, which may not be directly relevant to the activity of NF-kappaB. / To elucidate the mechanism responsible for the effect of PPARgamma and TGZ on lung cancer cells, we further studied the PPARgamma molecular pathway in NCIH23 treated by TGZ. The result demonstrated that TGZ induced PPARgamma and ERK1/2 accumulation in the nucleus, where the co-localization of both proteins was found. It showed that the activation of ERK1/2 resulted in apoptosis via the mitochondrial pathway, reflecting by reduction of mitochondria membrane potential, change in Bcl-2 family members, release of cytochrome c into cytosol, and activation of caspase 9. Both PPARgamma siRNA and U0126, a specific inhibitor of ERK1/2, were able to block these effects of TGZ, suggesting that apoptosis induced by TGZ was PPARgamma- and ERK1/2-dependent. Inhibition of ERK1/2 by U0126 also led to a significant decrease in the level of PPARgamma, indicating that there was probably a positive cross-talk between PPARgamma and ERK 1/2 or an auto-regulatory feedback mechanism to amplify the effect of ERK1/2 on cell growth arrest and apoptosis. In addition to ERK1/2, TGZ also activated Akt. Interestingly, inhibition of ERK1/2 prevented the activation of Akt whereas suppression of Akt had no effect on ERK1/2, suggesting that Akt was not necessary for TGZ-PPARgamma-ERK pathway. However, the inhibition of Akt promoted the release of cytochrome c. Thus, the activation of Akt may have a negative effect on apoptosis induced by TGZ. Wortmannin, a PI3K inhibitor, inhibited TGZ-induced ERK1/2 and Akt activation, indicating that PI3K may function at the up-stream of ERK and Akt. In conclusion, our study has demonstrated that TGZ induced apoptosis in NCI-H23 lung cancer cells via a mitochondrial pathway and this pathway was PPARgamma-and ERK1/2-dependent. / We first investigated the effect of PPARgamma ligand TGZ on two human lung cancer cells (NCI-H23 and CRL-2066) and one human lung normal cell (CCL-202). The results showed that in consistence with the loss of cell viability, TGZ induced apoptosis in CRL-2066 and NCI-H23 cells but not in CCL-202 cells. TGZ up-regulated PPARgamma expression in all these three lung cell lines, especially in the cancer cells. In association of the time-dependent inhibition of the cell proliferation, TGZ down-regulated the expression of Bcl-w and Bcl-2 but activated ERK1/2 and p38, suggesting that the growth-inhibitory effect of TGZ is associated with the reduction of Bcl-w and Bcl-2 and the increase of ERK1/2 and p38 activation. SAPK/JNK activation assay showed a decreased activity in all these three cell lines treated by TGZ. It was also demonstrated that TGZ was able to activate PPARgamma transcriptionally. We conclude that TGZ inhibits the growth of human lung cancer cells via the induction of apoptosis, at least in part, in a PPARgamma-relevant manner. / Li Mingyue. / "June 2006." / Advisers: George Gong Chen; Anthony Ping Chuen Yim. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6202. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 174-207). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

目的： 尽管过去几十年癌症的化疗取得了很大进步，但晚期非小细胞肺癌的预后仍然较差。表皮生长因子受体酪氨酸激酶抑制剂（epidermal growth factor receptor tyrosine kinase inhibitors，EGFR TKIs）给晚期非小细胞肺癌的患者带来了新的希望。然而，EGFR TKIs的总体效果有限，且不良反应较多，价格也较昂贵。如果能找到EGFR TKIs的疗效预测因子，则该治疗就可以只给予那些最有可能从中获益的人，从而提高成本效果，并使治疗变得更加个体化。 / 已有单组研究在接受EGFR TKIs治疗的患者中对有或没有某个标志物的人的预后进行了比较，发现EGFR基因突变、EGFR基因拷贝数增加、EGFR蛋白表达和KRAS基因突变这4个生物标志物可能能够预测EGFR TKIs的疗效。然而，此类研究的方法学是有缺陷的。要确定以上生物标志物是否有预测作用，应该在评估EGFR TKIs疗效的随机对照试验中作亚组分析，对该治疗在有某个生物标志物及没有某个生物标志物的患者中的疗效进行比较，检测治疗与生物标记物的交互作用。 / 但是，现有的随机对照试验通常样本量较小，统计效能不足，难以从中得到确定的结论。因此，我们做了一个随机对照试验的系统综述，以总结现有的最佳证据，对EGFR TKIs与上述4个生物标志物的交互作用进行评估。 / 方法： 我们检索了PubMed，EMBASE，考科蓝图书馆，中国生物医学文献数据库（中文），万方数据库（中文），美国临床肿瘤学会和欧洲肿瘤学会的会议摘要，以及相关原始研究、系统综述与Meta分析、临床指南、共识及专家意见的参考文献。检索时间截至2012年6月。合格研究为非重复、提供了具体数据且符合下列所有条件的研究：1）研究对象：晚期非小细胞肺癌患者；2）干预措施：EGFR TKIs单药治疗或联合其他药物治疗；3）对照措施：安慰剂对照，空白对照或化疗，或者它们任一种加上干预组的基线治疗；4）结局指标：无进展生存期和/或总生存期；5）研究设计：随机对照试验；6）根据上述任一种或多种生物标志物的状态作了亚组分析。 / 两名研究者平行独立地从合格研究中提取了患者特征、治疗方案、结局、生物标志物分析和方法学质量等方面的资料。对每一个研究，我们都根据生物标志物阳性亚组的风险比（hazard ratio）和阴性亚组的风险比计算了一个风险比之比（ratio of hazard ratios）来测量该标志物对疗效的预测能力或者说治疗与该生物标志物的交互作用。然后，采用随机效应模型对来自不同研究的风险比之比进行Meta分析；采用Cochran Q检验和I²评估研究间的异质性；通过敏感性分析考察原始研究的方法学质量等因素对结果的影响；采用Begg漏斗图和Egger检验来检测发表偏倚存在的可能性。 / 结果： 共有18个合格研究入选。可用于各个生物标志物分析的患者数量从1763到3246不等。原始研究普遍对关于方法学质量的信息报告得不够充分；有的研究可能存在重要偏倚。与安慰剂相比，EGFR TKIs可以有效延长无进展生存期和总生存期，但对总生存期的效果相对较小。除了在EGFR基因突变的患者中EGFR TKIs延长无进展生存期的效果明显好于化疗外，其它情形下，不管是无进展生存期还是总生存期，EGFR TKIs与化疗的效果均相当。 / 以无进展生存期为结局的风险比之比，在EGFR基因突变状态不同的亚组间（野生型亚组为参照）为0.37（95% 置信区间[CI]：0.22-0.60，P < 0.0001），EGFR基因拷贝数状态不同的亚组间（未增加的亚组为参照）为0.72（95% CI：0.52-0.99，P = 0.04），EGFR蛋白表达状态不同的亚组间（无表达的亚组为参照）为0.99（95% CI：0.78-1.26，P = 0.93），KRAS基因突变状态不同的亚组间（野生型亚组为参照）为1.35（95% CI：1.02-1.80，P = 0.04）。这些结果提示EGFR TKIs治疗与EGFR基因突变，EGFR基因拷贝数及KRAS基因突变之间可能存在交互作用。以总生存期为结局的风险比之比，在EGFR基因突变、EGFR基因拷贝数、EGFR蛋白表达及KRAS基因突变状态不同的亚组间分别为0.84（95% CI：0.64-1.11，P = 0.22）、0.92（95% CI：0.69-1.23，P = 0.57）、0.86（95% CI：0.70-1.05，P = 0.14）和1.37（95% CI：0.89-2.10，P = 0.15）。 / 就统计学显著性、异质性和稳定性而言，关于其它3个生物标志物的结果不如EGFR基因突变的相关结果确定，关于总生存期的结果不如无进展生存期的相关结果确定。没有证据表明本研究中存在发表偏倚。 / 结论： EGFR基因突变可用于确定哪些患者更有可能从EGFR TKIs治疗中获益。EGFR基因拷贝数增加和KRAS基因突变可能也有类似用途，但它们与治疗的交互作用是独立存在的还是由于它们与EGFR基因突变的相关性而获得的，目前尚不清楚。在EGFR野生型的患者中，选择化疗似乎比EGFR TKIs更好，因为它的副作用相对较少，且更为便宜。 / 本研究的结果为当前的临床指南提供了全面的证据支持。其它3个标志物在EGFR野生型患者中的预测价值可能还值得进一步的探讨，但我们更建议未来的研究在探讨治疗与生物标志物的交互作用时进行多因素分析。 / Objective: Despite the many new progresses in chemotherapy, the prognosis of advanced non-small cell lung cancer (NSCLC) remains poor. The introduction of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) seems to offer new promises for advanced NSCLC patients. However, EGFR TKIs have a limited overall efficacy, clear adverse events and large costs. It has become particularly appealing to identify, through new biomarkers, patients who are more likely to benefit from the treatment so that the treatment can be more personalized and effective. / EGFR mutations, EGFR gene copy number gain, EGFR protein expression and KRAS mutations were indicated as potential predictive biomarkers for the efficacy of the treatment in single-arm studies that compared survival of treated patients with and without a biomarker. However, such comparisons are flawed and the appropriate study design to evaluate the value of a biomarker in predicting efficacy which is known as interaction in epidemiology is the randomized controlled trial with stratified analysis that compared the efficacy of EGFR TKIs between patients with and without the biomarker. / As trials in this field are usually small in sample size and insufficiently powered for drawing a robust conclusion, we conducted this systematic review to summarize the evidence from all relevant randomized controlled trials that have data for investigating the interaction between EGFR TKIs and the 4 biomarkers. / Methods: PubMed, EMBASE, the Cochrane Library, Chinese Biomedical Literature Database (in Chinese), Wanfang Data (in Chinese), the abstracts of conferences of the American Society of Clinical Oncology and European Society of Medical Oncology, the reference list of relevant original studies, systematic reviews and meta-analyses, guidelines, consensus, and expert opinions were searched up to June 2012. / Eligible studies had to be non-duplicate, extractable studies meeting all the following criteria: 1) Population: patients with advanced NSCLC; 2) Intervention: EGFR TKIs alone or EGFR TKIs plus other treatments; 3) Control: placebo, no treatment, or chemotherapy, with or without the baseline treatments in the intervention arm; 4) Outcome: progression-free survival and/or overall survival; 5) Study design: randomized controlled trial; 6) Subgroup analyses were conducted according to the status of one or more of the 4 biomarkers. / Data on patients’ characteristics, treatment protocols, outcomes, biomarker analysis and methodological quality were extracted by two researchers independently. Within a study, we defined the measure of the value of a biomarker in predicting efficacy or biomarker-treatment interaction as the hazard ratio in patients with the biomarker relative to that in those without the marker. The ratio of hazard ratios from relevant studies was then combined by using the random-effect model. / Heterogeneity among studies was assessed by the Cochran’ Q test and I². Sensitivity analyses were conducted to examine the impact of factors such as methodological quality on the results. Begg’s funnel plots and Egger’s tests were used to examine the possibility of publication bias. / Results: Eighteen studies were included. The number of patients available for analyses on different biomarkers varied from 1,763 to 3,246. Data on the methodological quality of included studies are generally under-reported. Some studies seemed to have important biases. EGFR TKIs are in general effective in increasing progression-free and overall survival as compared with placebo although the effect size is smaller for overall survival than for progression free survival. EGFR TKIs are comparable to chemotherapy in their effect in prolonging both progression-free and overall survival, except in EGFR mutation group in which EGFR TKIs seem much more effective than chemotherapy in prolonging progression-free survival. / Importantly, for progression-free survival, the summary ratio of hazard ratios was 0.37 (95% confidence interval [CI]: 0.22-0.60, P < 0.0001) for EGFR mutations (versus wild-type), 0.72 (95% CI: 0.52-0.99, P = 0.04) for EGFR gene copy number gain (versus no gain), 0.99 (95% CI: 0.78-1.26, P = 0.93) for EGFR protein expression (versus negative), and 1.35 (95% CI: 1.02-1.80, P = 0.04) for KRAS mutations (versus wild-type), indicating interaction may exist between EGFR TKIs and EGFR mutation, EGFR gene copy number and KRAS mutations. For overall survival, the summary ratio of hazard ratios for EGFR mutations, EGFR gene copy number gain, EGFR protein expression and KRAS mutations was 0.84 (95% CI: 0.64-1.11, P = 0.22), 0.92 (95% CI: 0.69-1.23, P = 0.57), 0.86 (95% CI: 0.70-1.05, P = 0.14) and 1.37 (95% CI: 0.89-2.10, P =0.15), respectively. / In general, the results on EGFR gene copy number gain, KRAS mutations and EGFR protein expression were less certain than those on EGFR mutations in terms of statistical significance, consistency and robustness, and the results on overall survival were less certain than those on progression-free survival. Publication bias did not seem present in the study. / Conclusions: EGFR mutations and possibly EGFR-GCN and KRAS mutations can help identify who are more likely to benefit from EGFR TKIs treatment. However, it is not clear whether the interaction with EGFR-GCN and KRAS mutations are independent or obtained through their relation with EGFR mutations. Furthermore, in EGFR wild-type patients, given that chemotherapy is cheaper and of fewer side effects, chemotherapy seems clearly a better choice than EGFR TKIs. / Our findings provided the most comprehensive evidence for the recommendations of current guidelines. Although the predictive value of the other 3 biomarkers in wild-type EGFR patients may be worth further investigation, we suggest that multivariate analyses are explored in future studies of biomarker-treatment interactions. / 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. / 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. / Yang, Zuyao. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 88-104). / Abstracts also in Chinese. / Yang, Zuyao.