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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Investigation of the anti-tumor and anti-metastasis effects of selected Chinese medicines in metastatic breast cancer, and the combined use with zoledronate. / 傳統中藥及其與唑來磷酸二鈉四水合物(ZOL)聯合用藥在轉移型乳腺癌中對抗腫瘤及腫瘤轉移作用的研究 / CUHK electronic theses & dissertations collection / Chuan tong zhong yao ji qi yu zuo lai lin suan er na si shui he wu (ZOL) lian he yong yao zai zhuan yi xing ru xian ai zhong dui kang zhong liu ji zhong liu zhuan yi zuo yong de yan jiu

January 2013 (has links)
Luo, Kewang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 278-305). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
22

In vitro evaluation of the anti-cancer potential of miltirone in human hepatoma cells. / CUHK electronic theses & dissertations collection

January 2012 (has links)
丹參為雙子葉植物唇形科鼠尾草族植物的乾燥根及根莖。在中國,丹參為廣泛用於治療心血管疾病的藥用植物,而在西方,丹參也常作為一種輔助性藥物。《中國藥典2010版》收錄了35個以上含有丹參的複方或者方劑。在這些複方中,採用了富含丹酚酸和丹參酮的丹參水提物、乙醇提取物或兩者的混合物。丹參提取物具有較強的抗氧化作用,被認為在化學預防和化療的輔助治療中有一定用途。作為主要的丹參水溶性成分,熱敏感的丹酚酸在提取與加熱過程中可能會降解為其他丹酚酸。丹參水提取物的化學組成可能會在不同熱水提取溫度下有所不同,進而影響其藥理活性。在本研究中,通過加熱回流提取和在不同溫度下的微波提取(MAE-W)獲得了6種丹參水提取物,並對這些提取物進行化學成分和藥理分析,考察它們的抗氧化、抗凋亡和血管舒張作用。在這些提取物中,第三輪的微波提取物(100 oC)含有最多的丹酚酸和丹參酮,在1,1-二苯基-2-三硝基苯肼(DPPH)法和鐵還原/抗氧化能力(FRAP)法中具有最強的抗氧化活性,在2,2'-偶氮二(2-脒基丙烷)二鹽酸鹽(AAPH)誘導人血紅細胞的溶血實驗和過氧化氫誘導大鼠心肌細胞H9c2凋亡實驗中還顯示了最強的抑制作用,對大鼠腦基底動脈有最強的鬆弛效應。這些丹參水提取物的抗氧化作用與它們的血管舒張效應呈一定的線性關係(回歸係數r = 0.895 - 0.977)。通過多元線性回歸分析發現,丹參素可以作為丹參水提物的抗氧化和血管舒張功能的顯著性標記物,而丹參酮IIA則是抑制過氧化氫誘導大鼠心肌H9c2細胞凋亡的標記物。 / 作為丹參中主要的脂溶性成分,丹參酮在不同的腫瘤細胞系和荷瘤小鼠模型中展示了抗癌潛力。這些丹參酮的抗癌機制包括細胞週期阻滯,觸發半胱天冬酶(Caspase)依賴的內源性和外源性的凋亡途徑和絲裂原激活的蛋白激酶(MAPK)信號通路等。丹參新酮(miltirone)是從丹參中分離得到的松香烷型二萜醌類化合物,具有多種的藥理活性,如抗氧化,抗焦慮和抗腫瘤等。本研究評估了丹參新酮在人肝癌HepG2細胞系和P-糖蛋白(P-gp)過表達的阿霉素耐藥HepG2細胞系(R-HepG2)中的凋亡作用及其機制。丹參新酮在HepG2細胞中顯示了細胞毒性(EC₅₀值為7.06 微摩),而丹參新酮在抑制HepG2和R-HepG2細胞增殖中的濃度依賴性沒有顯著性差異。丹參新酮(1.56 - 6.25微摩)與阿霉素(DOX)對R-HepG2細胞的增殖具有協同效應,在達到50的生長抑制時,它們的聯合用藥指數為0.3至0.5。流式細胞術分析表明,丹參新酮降低了R-HepG2細胞中P-gp介導的阿霉素外排,分子對接研究表明該效果是通過抑制P-gp的藥物結合位點。在非壞死濃度(25微摩或以下),丹參新酮在HepG2和R-HepG2細胞中活化了Caspase依賴的凋亡途徑,誘導產生活性氧(ROS)和氧化應激,且觸發ROS介導的包括p38 MAPK,應激活化蛋白激酶/c-Jun氨基末端激酶(SAPK / JNK)以及細胞外調節激酶1和2在內的MAPK信號通路。綜上所述,在R-HepG2中丹參新酮是P-gp和細胞增殖的雙重抑制劑,顯示了其在治療肝癌(HCC)的潛力。 / 為了增加藥物開發的成功率,在藥物發現的早期階段應考察新化學實體(NCEs)的蛋白結合率,清除率,藥動學參數,以及藥物代謝相互作用等體內代謝參數。以往的研究已經顯示了從丹參中分離得到的四種主要丹參酮對人和大鼠的細胞色素P450酶介導的探針底物的代謝具有不同程度的抑制作用,需要注意丹參和其他藥物間的相互作用。本研究的另一目的是在人類肝微粒體中探討丹參新酮與探針底物間的細胞色素P450酶介導的代謝相關的相互作用。人肝微粒體孵育實驗結果表明丹參新酮對CYP1A2(IC₅₀值為 1.73微摩)和CYP2C9(IC₅₀值為8.61微摩)有中等強度的抑制,對CYP2D6(IC₅₀值為30.20微摩)和CYP3A4(IC₅₀值為33.88微摩)有弱的抑制。酶動力學和分子對接研究的結果進一步表明,丹參新酮為CYP1A2(Ki值為3.17微摩)的中等強度混合型抑制劑,是CYP2C9(Ki值為1.48微摩)的中等強度競爭型抑制劑,也是CYP2D6(Ki值為24.25微摩)和CYP3A4(Ki值為35.09微摩)的弱的混合型抑制劑。這些結果表明,應考慮丹參新酮與CYP1A2和CYP2C9代謝的藥物間的相互作用,但是可認為其與CYP2D6及CYP3A4代謝的藥物間幾乎不存在相互作用。 / 總之,本研究考察了不同提取方法對丹參提取物成份及其藥效的影響,確定了不同用途的丹參提取物的質控標記物。本研究還考察了丹參新酮體外抗肝癌的能力及其藥物代謝相互作用為基礎的類藥性,為其進一步的體內試驗提供了依據。 / Danshen, the dried root and rhizome of Salvia miltiorrhiza Bg. (Fam. Labiatae), is a widely used medicinal plant for the treatment of cardiovascular diseases in China and also a complementary medicine in the West. Danshen is indexed in the Pharmacopoeia of People’s Republic of China (2010 Edition), with more than 35 formulations and concoctions containing Danshen water-extracts, ethanolic extracts or their combination which are rich in phenolic acids and tanshinones with various contents. Danshen extracts have been considered for the use as an adjunct in chemoprevention and chemotherapy due to their strong antioxidant effects. Phenolic acids, the major water-soluble components in Danshen, are thermosensitive and may degrade to other phenolic acids during extractions upon heating. The chemical profiles of Danshen water-extracts may vary with different heat water extraction at different temperatures, affecting the composition and bioactivity of the extracts obtained. In this study, six water-extracts of Danshen obtained from heat reflux water extraction and microwave-assisted extraction with water (MAE-W) at different temperatures were prepared for evaluation of their composition and pharmacological effects such as antioxidant, anti-apoptosis and vascular relaxation. Among these extracts obtained, the third-round MAE-W (100 °C) product, which was the last round product obtained by extracting the same crude material three times, had the highest contents of phenolic acids and tanshinones, with the strongest antioxidant activity estimated by 2, 2-diphenyl-1-(2, 4, 6-trinitrophenyl) hydrazyl (DPPH) assay and ferric reducing / antioxidant potential (FRAP) assay. This extract also possessed the strongest inhibitory effects on 2, 2'-azobis-2-amidino-propane (AAPH)-induced haemolysis in human red blood cells, hydrogen peroxide-induced apoptosis in rat heart H9c2 cells and the highest relaxation effects on rat basilar artery. The antioxidant effects of Danshen water-extracts linearly correlated to their relaxation effects (r = 0.895 to 0.977). Through multiple linear regression analysis, danshensu was found to be the most significant marker in the antioxidant and vasodilation effects of Danshen water-extract, while tanshinone IIA as the marker on hydrogen peroxide-induced apoptosis in rat heart H9c2 cells. Danshensu is, therefore, a useful marker for the quality control of Danshen water-extracts in antioxidant and vasodilation, while tanshinone IIA for anti-apoptotic potential of water-extracts. / Tanshinones, the major lipid-soluble components isolated from Danshen, have been reported for their anti-cancer potential in various cell lines and tumor-bearing mice models. Their anti-cancer mechanisms are also well-studied, mainly through cell cycle arrest, caspase-dependent apoptotic pathways and mitogen activated protein kinase (MAPK) signaling pathways. Miltirone, another abietane type-diterpene quinone isolated from Danshen, has been reported for its anti-oxidative, anxiolytic and anti-cancer effects. This study evaluated the apoptotic effect of miltirone and the underlying mechanisms in a human hepatoma HepG2 cell line and its p-glycoprotein (P-gp)-overexpressed doxorubicin-resistant counterpart (R-HepG2). Miltirone showed similar cytotoxicity in HepG2 (EC₅₀ = 7.06 μM) and R-HepG2 (EC₅₀ = 12.0 μM), demonstrated synergistic effects (1.56 - 6.25 μM) with doxorubicin (DOX) on the growth inhibition of R-HepG2 (synergism: 0.3 < CI < 0.5 at 50 % inhibition). Flow cytometric analysis showed that miltirone decreased P-gp-mediated DOX efflux in R-HepG2, and molecular docking studies illustrated that this effect was through inhibition on the active site of P-gp. At non-necrotic concentrations (25 μM or below), miltirone activated caspase-dependent apoptotic pathways, and induced the generation of reactive oxygen species (ROS) and oxidative stress which triggered ROS-mediated MAPK signaling pathways, including p38 MAPK, stress-activated protein kinase / c-Jun N-terminal kinase (SAPK/JNK) and extracellular regulated kinase 1/2, in both HepG2 and R-HepG2 cells. It is therefore concluded that miltirone is a dual inhibitor on P-gp and cell proliferation in R-HepG2 cells, with potential for the treatment of human hepatocellular carcinoma (HCC). / In order to improve the successful rates in drug development, the in vivo metabolic parameters of new chemical entities (NCEs), such as protein bindings, clearance rate, pharmacokinetic parameters and metabolism-based drug-drug interactions, should be considered at the early stage of drug discovery. Previous studies have shown that major tanshinones isolated from Danshen inhibited the metabolism of model probe substrates of human and rat CYP450 enzymes, with potential in causing herb-drug interactions. The aim of this study was to study the effect of miltirone on the metabolism of model probe substrates of CYP1A2, 2C9, 2D6 and 3A4 in pooled human liver microsomes. Miltirone showed moderate inhibition on CYP1A2 (IC₅₀ = 1.73 μM) and CYP2C9 (IC₅₀ = 8.61 μM), and weak inhibition on CYP2D6 (IC₅₀ = 30.20 μM) and CYP3A4 (IC₅₀ = 33.88 μM). Enzyme kinetic studies showed that miltirone competitively inhibited CYP2C9 (Ki = 1.48 μM), and displayed mixed type inhibitions on CYP1A2, CYP2D6 and CYP3A4 with Ki values of 3.17 μM, 24.25 μM and 35.09 μM, respectively. Molecular docking study further confirmed the ligand-binding conformations of miltirone in the active sites of human CYP450 isoforms. These findings suggested that miltirone may have potential drug-drug interactions with CYP1A2- and CYP2C9-metabolized drugs, and to a lesser extent with CYP2D6- and CYP3A4-metabolized drugs. / In conclusion, this study investigated the effects of Danshen water-extracts produced by different extraction methods on the chemical compositions and pharmacological activities, and consequently confirmed the biomarkers for the quality control of Danshen water-extracts for different medicinal uses. This study also demonstrated the anti-cancer potential of miltirone for HCC in vitro and the metabolism-based drug-drug interactions for its drug-likeness, which may provide useful and promising data for in vivo anti-cancer study of miltirone and further pre-clinical studies. / 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, Xuelin / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 195-224). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i / 論文摘要 --- p.v / Publications based on the work in this thesis --- p.viii / Acknowledgements --- p.x / Abbreviations --- p.xii / Table of Contents --- p.xv / Chapter Chapter 1 --- General introduction --- p.1 / Chapter 1.1 --- Reactive oxygen species and carcinogenesis --- p.1 / Chapter 1.2 --- Reactive oxygen species and tumor progression & metastasis --- p.2 / Chapter 1.3 --- Antioxidant enzymes in chemoprevention and chemotherapy --- p.3 / Chapter 1.3.1 --- Glutathione and Glutathione reductase --- p.5 / Chapter 1.3.2 --- Glutathione Peroxidase --- p.5 / Chapter 1.3.3 --- Glutathione S-transferases --- p.6 / Chapter 1.3.4 --- NAD(P)H: quinone reductase 1 --- p.7 / Chapter 1.3.5 --- Heme oxygenase-1 --- p.8 / Chapter 1.3.6 --- Thioredoxin reductase --- p.9 / Chapter 1.3.7 --- Superoxide Dismutase --- p.10 / Chapter 1.3.8 --- Catalase --- p.11 / Chapter 1.4 --- Medicinal uses of Danshen --- p.12 / Chapter 1.5 --- Analysis of Danshen and its components --- p.14 / Chapter 1.6 --- Antioxidant effects of Danshen extract and its bioactive compounds in chemoprevention and chemotherapy-related disease --- p.19 / Chapter 1.7 --- Anti-cancer effects of tanshinones isolated from Danshen --- p.21 / Chapter 1.7.1 --- Tanshinone IIA --- p.22 / Chapter 1.7.2 --- Tanshinone I --- p.26 / Chapter 1.7.3 --- Cryptotanshinone --- p.27 / Chapter 1.7.4 --- Dihydrotanshinone --- p.27 / Chapter 1.8 --- Metabolism / disposition of Danshen and its major active ingredients --- p.28 / Chapter 1.9 --- Herb-drug interactions with Danshen --- p.31 / Chapter 1.10 --- Effects of Danshen (and its major active ingredients) on model probe substrates of CYP isoforms --- p.33 / Chapter 1.11 --- CYPs induction by Danshen and its active components --- p.38 / Chapter 1.12 --- Effects of Danshen / active ingredients on drug transporter proteins --- p.40 / Chapter 1.13 --- CYP450 inhibition screening for new chemical entity --- p.42 / Chapter 1.14 --- Molecular docking analysis --- p.44 / Chapter 1.15 --- The Aim of this study --- p.45 / Chapter Chapter 2 --- Quantitative and qualitative studies to evaluate the efficiency of different heat water-extractions --- p.48 / Chapter 2.1 --- Introduction --- p.48 / Chapter 2.2 --- Materials and methods --- p.51 / Chapter 2.2.1 --- Materials and apparatus --- p.51 / Chapter 2.2.2 --- Extraction procedures --- p.51 / Chapter 2.2.3 --- HPLC analysis --- p.54 / Chapter 2.2.4 --- DPPH assay and FRAP assay --- p.54 / Chapter 2.2.5 --- Inhibition of 2,2'-azobis-2-amidinopropane (AAPH)-induced haemolysis in human red blood cells --- p.55 / Chapter 2.2.6 --- Protective effects on hydrogen peroxide-induced apoptosis in rat heart H9c2 cells --- p.56 / Chapter 2.2.7 --- Vasodilation effects on rat basilar artery --- p.57 / Chapter 2.2.8 --- Statistical analysis --- p.58 / Chapter 2.3 --- Results and Discussion --- p.59 / Chapter 2.3.1 --- Chemical profiles analyzed by HPLC analysis --- p.59 / Chapter 2.3.2 --- DPPH assay and FRAP assay --- p.63 / Chapter 2.3.3 --- Inhibition of AAPH-induced haemolysis --- p.65 / Chapter 2.3.4 --- Protective effects on hydrogen peroxide-induced apoptosis --- p.69 / Chapter 2.3.5 --- Vasodilation effects on rat basilar artery --- p.71 / Chapter 2.3.6 --- Multiple linear regression analysis --- p.76 / Chapter Chapter 3 --- Effects of miltirone on cell proliferation in a hepatoma HepG2 cell line and its doxorubicin-resistant counterpart --- p.83 / Chapter 3.1 --- Introduction --- p.83 / Chapter 3.2 --- Materials and Methods --- p.87 / Chapter 3.2.1 --- Chemicals --- p.87 / Chapter 3.2.2 --- Cell culture --- p.87 / Chapter 3.2.3 --- Cell viability test --- p.88 / Chapter 3.2.4 --- Drug-efflux study by flow cytometry --- p.89 / Chapter 3.2.5 --- Molecular docking study and Ligand-based prediction --- p.90 / Chapter 3.2.6 --- Measurement of ROS generation by confocal microscopy and flow cytometry --- p.91 / Chapter 3.2.7 --- GSH and GSSG determination for oxidative stress --- p.93 / Chapter 3.2.8 --- Apoptosis-related proteins expression detected by Western blotting analysis --- p.94 / Chapter 3.2.9 --- Data analysis --- p.96 / Chapter 3.3 --- Results --- p.97 / Chapter 3.3.1 --- Cytotoxicity in hepatoma cells --- p.97 / Chapter 3.3.2 --- Drug-efflux study by flow cytometry --- p.104 / Chapter 3.3.3 --- Molecular docking study and Ligand-based prediction --- p.108 / Chapter 3.3.4 --- ROS generation --- p.113 / Chapter 3.3.5 --- Determination of GSH/GSSG ratio --- p.117 / Chapter 3.3.6 --- Caspase-dependent apoptosis. --- p.121 / Chapter 3.3.7 --- Phosphorylation of MAPKs --- p.126 / Chapter 3.4 --- Discussion --- p.134 / Chapter Chapter 4 --- Enzyme kinetic and molecular docking studies of miltirone on major human cytochrome P450 isozymes inhibitions --- p.139 / Chapter 4.1 --- Introduction --- p.139 / Chapter 4.2 --- Material and Methods --- p.141 / Chapter 4.2.1 --- Materials and Reagents --- p.141 / Chapter 4.2.2 --- Incubation conditions --- p.142 / Chapter 4.2.3 --- Samples preparation --- p.143 / Chapter 4.2.4 --- HPLC analysis --- p.143 / Chapter 4.2.5 --- CYP inhibition and enzymatic kinetic study --- p.144 / Chapter 4.2.6 --- Molecular docking analysis --- p.145 / Chapter 4.2.7 --- Data analysis --- p.146 / Chapter 4.3 --- Results --- p.148 / Chapter 4.3.1 --- CYP inhibition and enzymatic kinetic study --- p.148 / Chapter 4.3.2 --- Molecular docking study of miltirone --- p.167 / Chapter 4.4 --- Discussions --- p.184 / Chapter Chapter 5 --- General discussion --- p.188 / References --- p.195
23

Studies of tumor and MSCs interactions. / Studies of tumor and mesenchymal stem cells interactions

January 2013 (has links)
惡性腫瘤嚴重威脅著人類的身體健康,其治療也成為人類關注的焦點。傳統的化學療法和放射療法由於缺乏特異性,取得療效的同時往往也帶來較大的毒副作用。隨著對腫瘤發生發展分子機制認識的不斷深入,腫瘤的基因治療已成為攻克和治愈腫瘤最具希望和挑戰的研究領域。近年來研究發現骨髓間充斥幹細胞(MSCs)可被募集至腫瘤或損傷部位并參與腫瘤生長或組織修復,研究證明間充斥幹細胞通過靜脈注入帶瘤鼠(比如乳腺癌、膠質瘤、結腸癌及黑色素瘤)體內后,特異性的分佈于生長中的腫瘤中。這種特異性向腫瘤組織趨化轉移的特性使得骨髓間充斥幹細胞成為腫瘤基因靶向治療的載體的理想細胞。酶蛋白基因如單純皰疹病毒胸苷激酶(HSV-TK)可以使一些無毒或低毒的前藥轉化為強細胞毒性物質,殺死腫瘤細胞。我們前期實驗結果表明,通過遺傳改造后的表達TK基因的MSCs在GCV的存在下,具有殺傷腫瘤細胞抑制腫瘤生長的能力。但沒有改造的MSCs遷移至腫瘤之後可能會分化成成纖維細胞或者腫瘤基質細胞等支持腫瘤生長,但其命運和影響到底如何,我們怎麼樣進一步促進其向腫瘤的遷移以提高殺傷腫瘤的效率是本研究需要解決的問題。 / 本研究擬採用免疫螢光組織化學技術和分子生物學等技術研究和觀察MSCs對腫瘤(以乳腺癌,前列腺癌為例)的趨化過程及其在腫瘤生長中的作用,在在此基礎上研究促進攜帶HSV-TK自殺基因的MSCs的腫瘤靶向性細胞治療策略,採用分子和細胞生物學等方法評估其對荷瘤鼠體內腫瘤殺傷的原理,為利用TK-MSCs腫瘤的靶向治療奠定基礎。 / 研究結果顯示體外共培養的條件下,小鼠骨髓間充斥幹細胞可促進小鼠乳腺癌細胞增長,且增長速度同培養體系中間充斥幹細胞數目呈正相關。將兩種細胞混合注射于裸鼠體內,相比共注射小鼠皮膚成纖維細胞,間充斥幹細胞可促進體內腫瘤生長。使用人胚胎骨髓間充斥幹細胞和前列腺癌細胞可得出類似的效果。將腫瘤組織切片分析發現間充斥幹細胞促進體內腫瘤細胞增殖的同時,提高了腫瘤組織內血管密度。體外實驗發現共培養前列腺癌細胞和間充斥幹細胞可促進血管生成且在間充斥細胞內同血管增生相關的蛋白表達量都有相應提高,進一步證實間充斥幹細胞可能通過促進血管增生從而促進腫瘤生長。另外,我們利用人胚胎來源的骨髓間充斥幹細胞建立了穩定表達TK自殺基因的細胞系,且在GCV的存在下具有抑制腫瘤生長的能力。為了促進它們向腫瘤遷移的能力,我們用多柔比星預處理腫瘤細胞,和沒處理過的對照組相比,能增強對表達TK的間充斥幹細胞的招募能力。且在聯合利用多柔比星和TK的條件下,腫瘤生長能得到較大程度的抑制,這種抑制作用强於單獨使用多柔比星和表達自殺基因的間充斥幹細胞系統。初步認為是多柔比星的處理能增強腫瘤組織內炎性介質的分泌從而增強間充斥幹細胞的遷移達到增強自殺基因系統殺死腫瘤細胞的目的。 / 總的來說,雖然間充質幹細胞對腫瘤的生長存在一定的促進作用,但我們仍能對其進行遺傳改造,且在其它抗腫瘤藥的配合下達到最大的抗腫瘤效果。 / Eradication of cancer, especially when it has metastasized is extremely difficult and conventional cancer therapies are simply unable to specifically target tumors/cancers, thus causing unwanted side effects and complications. Recently, it has been shown that bone marrow mesenchymal stem cells (MSCs) are able to migrate specifically to tumors and contribute to the formation of tumor-associated stroma. These properties make MSCs good candidates as anti-tumor agent delivery vehicles and lead to a great deal of interest in the possibility of genetically modifying MSCs to express anticancer molecules and using them as specific targeted anticancer agents. We and others have showed that MSCs have the ability to migrate towards various cancer cells including breast, colon, fibrosarcoma and prostate cancer cells. Suicide gene therapy is widely used in cancer gene therapy. When stably infected with herpes simplex virus thymidine kinase gene by lentivirus, TK-MSCs maintained their MSCs characters and tumor tropism potential and significantly inhibited tumor growth, in the presence of the pro-drug ganciclovir (GCV). Improve MSCs homing to tumor tissue as anti-tumor gene therapy vehicles and maximizing their tumor killing effects is highly warranted. Furthermore, MSCs interact with tumor cells in numerous ways, which have the potential to support or suppress tumor growth. Therefore the fate and role of MSCs engrafted in tumor sites need to be clarified in order to making better use of these cells as anti-cancer agent delivery vehicles. / The aims of the current study are: (1) to study the role and fate of MSCs homed into the tumors; (2) to establish human bone marrow MSCs that stably express the TK genes; (3) to investigate the methods that enhance the anti-tumor efficiency of TK-MSCs. / In this study, bone marrow-derived mesenchymal stem cells from mice or human fetus were isolated and characterized. Effects of BM-MSCs on tumor cell proliferation in vitro were analyzed in a co-culture system with mouse breast cancer cell 4T1 cells. Both co-culture with BM-MSCs and treatment with MSC-conditioned medium led to enhanced growth of 4T1 cells. Co-injection of 4T1 cells and MSCs into nude mice led to increased tumor size compared with injection of 4T1 cells alone. Identical experiments using human prostate cancer cell DU145 cells and hBM-MSCs instead of 4T1 cells and mBM-MSCs yielded similar results. Compared with tumors induced by injection of cancer cells alone, tumor vessel area was greater in tumors from co-injection of 4T1 or DU145 with BM-MSCs, which correlated with decreased central tumor necrosis and increased tumor cell proliferation. Furthermore, both conditioned medium from co-cultures of hBM-MSCs and DU145 cells or hBM-MSCs alone was able to induce angiogenesis in human umbilical vein endothelial cells (HUVEC). When hBM-MSCs exposed to DU145 cells environment, the expression of markers associated with neovascularization (α-SMA, VEGF, TGF-β and IL6) were increased. Together, these results indicate that MSCs promote tumor growth both in vitro and in vivo and suggest that tumor promotion in vivo may be attributable in part to enhanced angiogenesis. / Immortalized human fetal bone marrow-derived MSCs (hfBMSCs) expressing herpes simplex virus thymidie kinase was established by conventional lentiviral transduction method. Functional expression of TK was evaluated by cytotoxicity in the presence of its prodrug GCV. SV40-TK-hfBMSCs exhibited comparable proliferation, surface phenotype expression, multi-differentiation potential and tumor-tropic migration ability as hfBMSCs. By measurement of tumor volume, repeated injection of the SV40-TK-hfBMSCs and subsequent consecutive GCV administration could suppress tumor growth in DU145 or PC3 human prostate tumor xenograft nude mice model without causing weight loss. However, its clinical applications are still limited. Alternative strategies have been pursued in this study by the use of combination therapy with cytotoxic chemotherapy to improve the overall efficacy of the TK-hfBMSCs/GCV system. / TK-hfBMSCs/GCV was evaluated alone or combined with low-dose doxorubicin in human prostate carcinoma DU145 xenografts in nude mice, testing for effects on local growth and overall survival. Tissues were evaluated through immunofluorescence and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining (TUNEL) for treatment effects on tumor cell proliferation and apoptosis. Transwell migration assay was used to access the migration ability of TK-hfBMSCs to tumor cells upon doxorubicin treatment and caspase-3 activity was conducted for test the tumor cells apoptosis under TK-hfBMSCs/GCV, doxorubicine, or combination of the two compound treatments respectively. Only minimal growth inhibition was observed in DU145 after treatment with TK-hfBMSCs/GCV or doxorubicin alone at doses and time points as indicated. In contrast, the combination of both agents resulted in a significant growth inhibition. Caspase-3, plays a central role in the execution-phase of cell apoptosis, was increased by TK-hfBMSCs/GCV or doxorubicine and also to a much greater extent by the combination treatment. Treatment by TK-hfBMSCs/GCV resulted in only a slight decrease in tumor growth compared with controls. Treatment with low-dose doxorubicin alone resulted in a small, nonstatistically significant decrease in tumor growth; In contrast, combined low-dose doxorubicin and TK-hfBMSCs/GCV was markedly inhibitory compared with control, doxorubicin alone, or TK-hfBMSCs/GCV alone. During the whole treatment process, no significant weight loss was observed. Furthermore, combined therapy induced increased area of necrosis, significant apoptosis and decreased tumor cell proliferation in treated tumors. Taken together, low dosage of doxorubicin could be used in combination with TK-hfBMSCs based suicide gene therapy. / In conclusion, we have demonstrated that BM-MSCs could increase the growth of human prostate cancer and mouse breast cancer. The promotion effect may partly attribute to the increased expression of pro-angiogenic factors in BM-MSCs in tumor microenvironment and subsequent enhancement in angiogenesis and tumor growth. The current study also suggests combination of TK-hfBMSCs/GCV and doxorubicin was more effective in inhibiting prostate cancer cells growth than TK-hfBMSCs/GCV or doxorubicin alone. Although many problems need to be resolved for further application, our study provided the possibility of a new strategy of suicide gene-based therapy accompanied by low dosage of chemotherapy in treating prostate cancer. Therefore MSCs were described as a “double-edged sword in their interaction with tumors. However, if MSCs are suitably engineered with anticancer genes they could be employed as a valuable “single-edged sword“ against cancers. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zhang, Ting. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 120-158). / Abstracts also in Chinese. / ACKNOWLEDGEMENT --- p.ii / PUBLICATIONS --- p.vii / ABSTRACT --- p.xiii / Chapter CHAPTER 1 --- Introduction --- p.1 / Chapter 1.1 --- Mesenchymal stem cells (MSCs) --- p.2 / Chapter 1.2 --- Tumor microenvironment and involvement of MSCs in tumor establishment --- p.5 / Chapter 1.3 --- Tumors-tropic characteristics of MSCs --- p.15 / Chapter 1.4 --- Impact of MSCs on in vivo tumors --- p.21 / Chapter 1.5 --- In vivo imaging demonstrating MSCs tumor-homing potentials --- p.25 / Chapter 1.6 --- Evidence for use of MSCs as anti-tumor agents delivery vehicles --- p.26 / Chapter 1.7 --- Homing strategies to enhance efficacy and safety of MSCs therapy --- p.32 / Chapter 1.8 --- Summary --- p.35 / Chapter CHAPTER 2 --- Hypotheses, Objectives and Study Design --- p.35 / Chapter 2.1 --- Hypothesis --- p.35 / Chapter 2.2 --- Objective --- p.36 / Chapter 2.3 --- Study design --- p.37 / Chapter CHAPTER 3 --- Bone Marrow-derived Mesenchymal Stem Cells Promote Growth and Angiogenesis of Breast and Prostate Tumors (Study I) --- p.40 / Chapter 3.1 --- Materials and Methods --- p.40 / Chapter 3.2 --- Results --- p.49 / Chapter 3.3 --- Discussion --- p.64 / Chapter 3.4 --- Conclusions --- p.67 / Chapter CHAPTER 4 --- Immortalized human fetal bone marrow-derived mesenchymal stem cell expressing anti-tumor suicide gene for anti-tumor therapy in vitro and in vivo (Study II) --- p.68 / Chapter 4.1 --- Materials and Methods --- p.68 / Chapter 4.2 --- Results --- p.73 / Chapter 4.3 --- Discussion --- p.85 / Chapter CHAPTER 5 --- Enhanced antitumor effects by combination therapy using mesenchymal stem cell expressing anti-tumor suicide gene and Doxorubicin in a xenograft mouse model (Study III) --- p.89 / Chapter 5.1 --- Materials and Methods --- p.89 / Chapter 5.2 --- Results --- p.97 / Chapter 5.3 --- Discussion --- p.111 / Chapter CHAPTER 6 --- General discussion and conclusions --- p.116 / Chapter 6.1 --- General discussion --- p.116 / Chapter 6.2 --- General conclusions --- p.119 / FUNDING --- p.120 / REFERENCE --- p.120
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Effects of TNF-ALPHA, taxol and hyperthermia on human breast tumour cells. / CUHK electronic theses & dissertations collection

January 1997 (has links)
by Li Jian Yi. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (p. 157-181). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
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Epigenetic disruption of tumor suppressor genes as antagonists to Ras or Wnt signaling contributes to tumorigenesis. / 針對Ras或Wnt信號通路的拮抗因子的表觀遺傳調控及功能學研究 / CUHK electronic theses & dissertations collection / Zhen dui Ras huo Wnt xin hao tong lu de jie kang yin zi de biao guan yi chuan diao kong ji gong neng xue yan jiu

January 2012 (has links)
全球人類健康的頭號殺手--腫瘤目前仍是難以攻克的醫學難題。腫瘤的發生是一個復雜的過程,主要由促癌基因的異常增多或激活及抑癌基因(TSG)的缺失或功能喪失的累積效果導致。近年來基於非基因序列改變所致基因表達水平變化的表觀遺傳學的研究進展表明,啟動子區CpG島甲基化所致的表觀遺傳沉默是抑癌基因轉錄失活的重要機制。Ras和Wnt信號轉導通路在癌病的發生和發展過程中均起到重要的作用,因此針對該兩種信號通路的拮抗因子的表觀遺傳調控及功能學研究將為我們提供有研究及應用前景的候選抑癌基因。 / 作為一種重要的原癌基因,Ras家族基因具有致癌活性的點突變及其導致的過度激活的Ras信號通路被發現廣泛存在於大約30%的人類腫瘤中。然而在一些缺乏Ras基因突變的腫瘤類型中,持續激活的Ras信號通路仍然普遍存在並具有重要作用,昭示著除了Ras基因點突變以外的信號轉導異常激活的機制。與GTP的結合可激活Ras,而RasGAP家族蛋白可通過水解GTP達到使Ras失活的作用。通過采用微陣列比較基因組雜交(aCGH)的實驗手段我們發現6p21.3染色體區具有半接合子缺失, 並於此區域發現了候選抑癌基因RASA5。在以往的研究報道中,RASA5被命名為SynGAP且其功能研究僅限於神經系統。我們的研究發現不同於RasGAP家族的其它基因RASA2-4,RASA5廣泛表達於人類正常器官組織中,並特異性地在腫瘤細胞,特別是鼻咽癌(NPC),食管鱗狀上皮細胞癌(ESCC)和乳腺癌這些具有野生型Ras基因但Ras信號通路仍被過度激活的細胞中被表觀遺傳沉默。RASA5的異位表達可有效促進腫瘤細胞的雕亡,抑制腫瘤細胞的生長、遷移及“幹性(stemness)“。同時,使用siRNA敲除內源性RASA5可以激發細胞的克隆形成及上皮-間質(EMT)轉化。RASA5的抑癌功能是通過調低Ras-GTP水平並進而抑制其下遊信號通路的活性實現的。過量表達具有致癌活性的點突變的Ras或RasGAP結構域缺失均可部分逆轉這種抑癌作用。此項研究首次證明了RASA5的抑癌功能。 / Wnt/Dvl/β-catenin信號轉導通路在人類腫瘤中存在廣泛的異常激活。我們發現DACT (Dpr/Frodo)家族成員TUSC-T2的表觀遺傳沉默是一種普遍存在於人類腫瘤中的現象。TUSC-T2編碼一種胞質蛋白,外源性表達TUSC-T2可促進腫瘤細胞雕亡並導致腫瘤細胞的克隆形成能力下降。TUSC-T2可與Dvl蛋白結合並下調其活化水平,從而保護GSK-3β蛋白不被Dvl蛋白抑制。GSK-3β可與Axin及APC蛋白形成蛋白質復合物,該復合物可捕捉並降解細胞內信號分子β-catenin。TUSC-T2的過量表達可以抑制β-catenin的激活及其向細胞核內的富集,並進一步阻止β-catenin在細胞核內與Lef/Tcf轉錄因子家族的作用及下遊特定原癌基因,例如c-Myc, CCND1及Fibronectin的表達。因此TUSC-T2具有抑制腫瘤細胞增殖、遷移及上皮-間質(EMT)轉化的作用。 / 綜上所述,我們的研究結果表明RASA5及TUSC-T2是具有抑癌功能的Ras或Wnt/Dvl/β-catenin信號轉導通路抑制因子,其表觀遺傳沉默導致的轉錄失活對於腫瘤的發生發展具有重要意義。同時,針對這兩種抑癌基因的進一步研究將為我們提供富有應用前景的腫瘤標記物。值得註意的是,RASA5課題的研究開創性地闡明了Ras信號通路的拮抗因子的表觀遺傳沉默是一種Ras信號轉導通路於腫瘤細胞中異常激活的新機制。 / Cancer is the top killer of the world, as well as the medical problem difficult to overcome. The conversion of a normal cell to a cancer cell is usually caused by upregulation of oncogenes and downregulation of tumor suppressor genes (TSGs). Epigenetic silencing has been proved to be important in TSGs inactivation, often through methylation of CpG-rich promoter regions. Ras and Wnt signaling pathways are both important for the tumorigenesis, epigenetic and functional studies of antagonists to Ras and Wnt signaling would provide us with candidate TSGs. / Ras is a well-known oncogene. Aberrant mutations of Ras genes occur in approximately 30% of human tumors, causing constitutively activated Ras signaling. However, in certain types of tumors with wild type Ras genes, abnormally activated Ras signaling is still a common and critical event, suggesting alternative mechanisms for Ras signaling hyperactivation. Ras is active when it is bound to GTP, while the hydrolysis of bound GTP and inactivation of Ras is catalyzed by Ras GTPase activating proteins (RasGAPs). Using 1-Mb array CGH (aCGH), we refined a small hemizygous deletion at the 6p21.3 chromosome region that contains a RasGAP family member gene RASA5, which used to be named as SynGAP and studied only in the neuron systems. We demonstrated that RASA5, rather than other RasGAP family members RASA2-4, is broadly expressed in human normal tissues while frequently epigenetically silenced in multiple tumors, especially in certain tumor types such as nasopharyngeal (NPC), esophageal (ESCC) and breast carcinomas (BrCa) with wild-type Ras while Ras cascade is still constitutively active. Ectopic expression of RASA5 led to apoptosis, growth and migration inhibition, as well as ‘stemness’ repression of tumor cells. Meanwhile, knockdown of RASA5 by siRNA promoted the tumor cell colony formation as well as epithelial-mesenchymal transition (EMT). The tumor-suppressive function of RASA5 was exerted through downregulating Ras-GTP level and further inactivating Ras signaling. Such an inhibitory effect could be partially abrogated in the presence of mutated, activated Ras or by deletion of the RasGAP domain. For the first time, our study refined the role of RASA5 as a tumor suppressor. / Wnt/DVL/β-catenin signaling pathway is aberrantly activated in a wide range of human cancers. We identified a DACT (Dpr/Frodo) family member TUSC-T2 as an epigenetically downregulated gene in human tumors. TUSC-T2 encodes a punctate cytoplasmic protein. Ectopic expression of TUSC-T2 dramatically inhibited tumor cell colony formation in silenced tumor cell lines, mainly through inducing apoptosis. TUSC-T2 interacts and downregulates Dishevelled (Dvl) protein, thus protecting glycogen synthase kinase 3β (GSK-3β) from inactivation by Wnt/Dvl and allowing GSK-3β to form a complex with Axin and APC to promote the phosphorylation and proteasomal degradation of β-catenin. Overexpression of TUSC-T2 disrupted β-catenin activation and accumulation in nuclei, thus preventing its binding to transcription factors of the Lef/Tcf family. This caused the downregulation of β-catenin target oncogenes such as c-Myc, CCND1 and Fibronectin as well as the inhibition of tumor cell proliferation and migration. We also observed that TUSC-T2 could inhibit tumor cell EMT. / Taken together, our data demonstrate that RASA5 and TUSC-T2 are functional tumor suppressors epigenetically silenced in multiple tumors through acting as negative regulators of the Ras or Wnt/Dvl/β-catenin cancer pathways, and could be developed as promising biomarkers for human tumors. Of note, our study reveals that epigenetic silencing of the Ras antagonist represents a new mechanism responsible for Ras aberrant activation in cancers with wild-type Ras. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Fan, Yichao. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 184-216). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Acknowledgements --- p.i / List of abbreviations --- p.ii-iii / List of tables --- p.iv / List of Figures --- p.v-vii / List of Publications --- p.viii-ix / Abstract in English --- p.x-xii / Abstract in Chinese --- p.xiii-xiv / Table of Contents --- p.xv / Chapter Chapter 1 --- Introduction and Literature Review --- p.1 / Chapter 1.1 --- Cancer epigenetics --- p.4 / Chapter 1.1.1 --- Epigenetic modifications --- p.5 / Chapter 1.1.1.1 --- DNA Methylation --- p.5 / Chapter 1.1.1.2 --- Histone modifications --- p.10 / Chapter 1.1.1.3 --- RNA interference --- p.14 / Chapter 1.1.1.4 --- Nucleosome positioning --- p.15 / Chapter 1.1.2 --- Epigenetic alteration induced Tumor suppressor genes (TSGs) silencing during carcinogenesis --- p.17 / Chapter 1.2 --- Epigenetic alterations in cancer pathways --- p.23 / Chapter 1.2.1 --- Brief introduction of cancer pathways --- p.23 / Chapter 1.2.2 --- Ras pathway --- p.25 / Chapter 1.2.2.1 --- Ras pathway and carcinogenesis --- p.25 / Chapter 1.2.2.2 --- Epigenetic regulation of RasGAP proteins in carcinogenesis --- p.28 / Chapter 1.2.2.3 --- Epigenetic silencing of other negative regulators of Ras signaling --- p.30 / RAS association domain family (RASSF) proteins --- p.30 / PTEN --- p.32 / Sprouty (SPRY) proteins --- p.33 / Chapter 1.2.2.4 --- Hypomethylation induced Ras oncogenes activation --- p.35 / Chapter 1.2.2.5 --- Ras mediates epigenetic regulation through feedback loop --- p.36 / Chapter 1.2.3 --- Wnt pathway --- p.43 / Chapter 1.2.3.1 --- Wnt signaling pathway and carcinogenesis --- p.43 / Chapter 1.2.3.2 --- Epigenetic silencing of negative regulators of Wnt signaling --- p.45 / Chapter 1.2.3.3 --- DACT family proteins and carcinogenesis --- p.48 / Chapter 1.3 --- Application of tumor specific epigenetic alterations as tumor biomarkers and therapeutic targets --- p.49 / Chapter 1.3.1 --- The potential and advantage of tumor specific epigenetic alterations used as tumor biomarkers and therapeutic targets --- p.49 / Chapter 1.3.2 --- Epigenetic-disrupted regulators of Ras signaling as tumor biomarkers and therapeutic targets --- p.50 / Chapter 1.3.3 --- Epigenetic-disrupted regulators of Wnt signaling as tumor biomarkers and therapeutic targets --- p.52 / Chapter Chapter 2 --- Aims of this study --- p.54 / Chapter 2.1 --- To identify epigenetically silenced candidate TSGs as antagonists to Ras or Wnt signaling --- p.55 / Chapter 2.2 --- To elucidate the functional of candidate TSGs --- p.56 / Chapter Chapter 3 --- Materials and Methods --- p.57 / Chapter 3.1 --- Cell lines, tumor samples and routine cell line maintenance --- p.57 / Chapter 3.2 --- Drug and stress treatments --- p.59 / Chapter 3.3 --- DNA and RNA extraction --- p.59 / Chapter 3.4 --- Semi-quantitative RT-PCR and Real time PCR --- p.60 / Chapter 3.5 --- Direct sequencing of PCR products --- p.67 / Chapter 3.6 --- CpG island analysis --- p.67 / Chapter 3.7 --- Bisulfite treatment --- p.67 / Chapter 3.8 --- Methylation-specific PCR (MSP) and bisulfite genomic sequencing --- p.68 / Chapter 3.9 --- Plasmid extraction --- p.69 / Chapter 3.9.1 --- Bacteria culture --- p.69 / Chapter 3.9.2 --- Mini-scale preparation of plasmid DNA --- p.70 / Chapter 3.9.3 --- Large-scale endotoxin-free plasmids extraction --- p.71 / Chapter 3.10 --- Construction of expression plasmids --- p.71 / Chapter 3.10.1 --- Gene cloning and plasmids construction of RASA5 --- p.71 / Chapter 3.10.2 --- Gene cloning and plasmids construction of TUSC-T2 --- p.74 / Chapter 3.11 --- Immunofluorescence Staining --- p.74 / Chapter 3.12 --- Colony formation assay --- p.76 / Chapter 3.13 --- Apoptosis assay --- p.77 / Chapter 3.14 --- Luciferase reporter assay --- p.78 / Chapter 3.15 --- Protein preparation and Western blot --- p.79 / Chapter 3.16 --- Ras Activity Assay --- p.80 / Chapter 3.17 --- Wound healing assay --- p.81 / Chapter 3.18 --- Matrigel invasion assay --- p.81 / Chapter 3.19 --- RNA Interference --- p.81 / Chapter 3.20 --- Statistical analysis --- p.82 / Chapter Chapter 4: --- Epigenetic disruption of Ras signaling through silencing of a Ras GTPase-activating protein RASA5 in human cancers --- p.83 / Chapter 4.1 --- Identification of RASA5 as a downregulated gene residing in the 6p21.3 deletion region --- p.86 / Chapter 4.2 --- RASA5 is widely expressed in human normal tissues but downregulated in tumor cell lines --- p.91 / Chapter 4.3 --- The tumor-specific downregulation pattern of RASA5 is unique in the RASA family genes --- p.95 / Chapter 4.4 --- RASA5 promoter CpG methylation resulted in its transcription inactivation --- p.96 / Chapter 4.5 --- Frequent methylation of RASA5 promoter in multiple primary tumors --- p.101 / Chapter 4.6 --- Cloning and characterization of human RASA5 --- p.104 / Chapter 4.7 --- RASA5 inhibits tumor cell clonogenicity through inducing apoptosis --- p.108 / Chapter 4.8 --- RasGAP domain is required for the tumor suppressive function of RASA5 --- p.111 / Chapter 4.9 --- Certain cancer types harbor wild type Ras but active Ras signaling, with RASA5 epigenetically silenced --- p.114 / Chapter 4.10 --- RASA5 antagonizes Ras signaling pathway --- p.117 / Chapter 4.10.1 --- RASA5 represses Ras signaling through downregulating Ras-GTP level --- p.117 / Chapter 4.10.2 --- Oncogenic mutant form of Ras abrogated colony formation inhibitory effect of RASA5 on tumor cells --- p.120 / Chapter 4.10.3 --- Knockdown of RASA5 promoted the tumor cell colony formation and Ras signaling activation --- p.122 / Chapter 4.10.4 --- RASA5 inhibits ERK1/2 nuclei translocation and activation --- p.123 / Chapter 4.10.5 --- RASA5 negatively regulates Ras target gene expression --- p.125 / Chapter 4.11 --- RASA5 inhibits tumor cell migration and invasion through the Ras/Rac/cofilin signaling --- p.127 / Chapter 4.12 --- RASA5 suppresses tumor cell epithelial-mesenchymal transition (EMT) and stemness --- p.133 / Chapter 4.13 --- RASA5 appears in the cellcell interaction region nanotubes --- p.139 / Chapter 4.14 --- Discussion --- p.141 / Chapter Chapter 5: --- The Wnt/Dvl signaling antagonist TUSC-T2 is a pro-apoptotic tumor suppressor epigenetically silenced in tumors and inhibits tumor cell proliferation and migration --- p.150 / Chapter 5.1 --- Expression of TUSC-T2 is downregulated in human tumors --- p.150 / Chapter 5.2 --- TUSC-T2 promoter methylation results in its transcriptional inactivation --- p.151 / Chapter 5.3 --- Cloning and characterization of TUSC-T2 --- p.155 / Chapter 5.4 --- TUSC-T2 inhibits tumor cell clonogenicity through inducing apoptosis --- p.157 / Chapter 5.5 --- TUSC-T2 inhibits Wnt/Dvl/β-catenin pathway --- p.161 / Chapter 5.6 --- TUSC-T2 suppresses cell migration and EMT through upregulating E-cadherin --- p.165 / Chapter 5.7 --- Discussion --- p.171 / Chapter Chapter 6: --- Conclusions --- p.176 / Chapter 6.1. --- RasGAP family member RASA5 is epigenetically silenced in human cancers, acting as a tumor suppressor through negatively regulating Ras signaling --- p.177 / Chapter 6.2. --- DACT family member TUSC-T2 functions as a candidate TSG silenced by promoter methylation and inhibits Wnt/Dvl/β-catenin pathway --- p.178 / Chapter Chapter 7: --- Future Studies --- p.181 / Chapter 7.1. --- Further functional study of RASA5 and TUSC-T2 --- p.181 / Chapter 7.2. --- Clinical application of epigenetic silenced candidate TSGs --- p.182 / Chapter 7.3. --- Further screening of candidate TSGs as antagonists to cancer pathways --- p.183 / Reference list --- p.184
26

Hepatoma-derived growth factor regulation of the growth, the radiosensitivity and the chemosensitivity of human cancer cells. / 肝癌衍生生長因子(HDGF)對人類癌細胞的生長, 輻射敏感性及藥物敏感性之影響 / CUHK electronic theses & dissertations collection / Gan ai yan sheng sheng zhang yin zi (HDGF) dui ren lei ai xi bao de sheng zhang, fu she min gan xing ji yao wu min gan xing zhi ying xiang

January 2008 (has links)
Hepatoma-derived growth factor (HDGF) is commonly over-expressed in human cancer cells. It was able to stimulate cell growth. The expression level of HDGF was reported to correlate with poor prognosis of cancer therapy. It was found that HDGF is over-expressed in the fractionated gamma radiation conditioned HepG2 cells, which have higher growth rate, lower radiosensitivity and higher drug sensitivity. The aim of the present study was to investigate the role of HDGF in mediating these changes in human cancer cells and the underlying mechanisms. The results indicate that transfection of HDGF cDNA carrying vector stimulated the growth of cancer cells while knock-down of HDGF by transfection of HDGF antisense oligos not only suppressed the growth but also triggered apoptosis in human cancer cells. It suggests that HDGF stimulates cancer cell growth and acts as a survival factor for human cancer cells. Mechanistic study showed that knock-down of HDGF may trigger apoptosis through the regulation of the apoptotic pathways. The apoptosis induced by HDGF knock-down was mediated by the BAD regulated intrinsic apoptotic pathway and the Fas regulated extrinsic apoptotic pathway. The HDGF knock-down induced apoptosis was also mediated by the changes in the activity of the cell survival pathways, including the Ras/Raf/MEK/ERK, PI3K/Akt, NFkappaB and Jak/STAT pathways. In addition to the growth promoting function, HDGF was found to regulate the radiosensitivity and chemosensitivity of cancer cells. Overexpression of HDGF reduced the radiosensitivity and the level of apoptosis induced by gamma radiation. On the contrast, overexpression of HDGF increased the chemosensitivity and the level of apoptosis induced by anti-cancer drugs, including Taxol, doxorubicin (Dox) and tamoxifen. The results indicated that HDGF may stimulate the growth, reduce the radiation sensitivity and increase the drug sensitivity of cancer cells. HDGF may also be responsible for the changes in cancer cell properties after fractionated gamma radiation treatment. The present findings suggest that HDGF may be a potential target for cancer therapy. / Tsang, Tsun Yee. / Adviser: Tim Tak Kwok. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3497. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / 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.
27

The effect of a selective COX-2 inhibitor, celecoxib, on the proliferation, apoptosis and differential protein expression in nasopharyngeal carcinoma cell lines. / 選擇性環氧合酶-2抑製劑, 塞來昔布, 對於鼻咽癌細胞系之增生, 細胞凋亡及蛋白差異表達的影響 / CUHK electronic theses & dissertations collection / Xuan ze xing huan yang he mei-2 yi zhi ji, sai lai xi bu, dui yu bi yan ai xi bao xi zhi zeng sheng, xi bao diao wang ji dan bai cha yi biao da de ying xiang

January 2008 (has links)
Celecoxib is a COX-2 selective non-steroidal anti-inflammatory drug which has been shown to inhibit growth and induce apoptosis in various cancer cell lines. Using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and an apoptosis detection kit, we demonstrated that celecoxib was able to induce growth inhibition and apoptosis in a dose-dependent manner in 3 NPC cell lines: HK-1, Hone-1, and C666-1. Afterwards, a proteomic approach was used to study the underlying mechanisms involved in celecoxib-mediated effects on two COX-2 positive NPC cell lines (HK-1 and C666-1). Results showed that a total of 18 protein spots were differentially expressed in the HK-1 and C666-1 cells. On the other hand, we also compared the proteomic expression profile between an NPC cell line (C666-1) and a normal nasopharynx cell line (NP69) in order to study whether those differentially expressed proteins after celecoxib treatment were also involved in NPC carcinogenesis. Proteomics results with confirmation using Western blotting discovered that HSP27 phosphorylated of serine 82 (HSP27-pSer82) protein was up-regulated in C666-1 cells when compared with that in NP69 cells. After treatment with celecoxib, expression of HSP27-pSer82 protein was down-regulated in both HK-1 and C666-1 cells. These findings suggest that down-regulation of HSP27-pSer82 protein expression may have mediated the growth-inhibitory effects of celecoxib in HK-1 and C666-1 cells. Finally, other differential expressed proteins identified from proteomics with confirmation by immunocytochemical staining in the 2 NPC cell lines and 40 NPC patient specimens showed that down-regulation of annexin 2 and beta2-tubulin may be important in NPC formation. / COX-2 over-expression has been found in various cancers such as colorectal cancer, liver cancer and lung cancer. In vivo studies have shown that mice overexpressing COX-2 developed breast cancer whereas COX-2 knockout mice had reduced rates of cancer formation in the intestines and skin. In the present study, COX-2 expression in NPC patient biopsies was examined and correlated with the clinicopathological data of the patients. Immunocytochemical staining showed that COX-2 protein was over-expressed in 84.6% (66/78) of non-metastatic NPC patients and was associated with an advanced nodal stage (P&lt;0.05). All these data support an important role for COX-2 in NPC pathogenesis. / In summary, this study is the first to identify HSP27-pSer82 protein as a potential target of celecoxib in NPC cells. Detailed investigations of the functional role of molecular targets identified in this study would improve our understanding of the chemotherapeutic effects of celecoxib and, in the long run, may lead to a more effective chemotherapeutic treatment to this common cancer. / Nasopharyngeal carcinoma (NPC) is prevalent in southern China. Although early stage patients have a high rate of cure with radiotherapy alone, the prognosis for those with stage III or IV disease remains poor due to subsequent development of distant metastases. Therefore there is an urgent need to develop novel biologic agents to improve treatment outcomes. / Chan, Ming Lok. / Adviser: Anthony T.C. Chan. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3418. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 141-171). / 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.
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The anti-tumor mechanism of PPAR[gamma] activator troglitazone in human lung cancer. / CUHK electronic theses & dissertations collection

January 2006 (has links)
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.
29

Investigations of MicroRNAs in urine supernatant for the diagnosis of bladder cancer and the potential functional roles of miR-99a.

January 2012 (has links)
膀胱尿路上皮腫瘤發病率在泌尿道腫瘤中排第二位,它具有高複發性的特點。目前,有創性尿道膀胱鏡檢查是診斷的金標準。儘管先後有很多血液或尿液中的分子被先後用於診斷膀胱癌的診斷研究,但到目前為止尚未有任何一種方法可以取代膀胱鏡檢查。有證據表明在膀胱上皮腫瘤組織中有很多異常表達的microRNA,但是內在機制的有關研究相對缺乏。在本研究中,我們利用在尿液上清中異常表達的microRNA來評估它們在膀胱癌診斷中的價值。而且,我們揭示了其潛在的調控機理。通過microRNA基因芯片,我們結合并對比來自膀胱腫瘤病人和正常對照患者的9個尿液上清樣本,以及4對腫瘤組織及臨近正常黏膜上皮中microRNA的表達,初步篩選出10個異常的microRNA。然後我們使用定量RT-PCR的方法在另外獨立的18對腫瘤組織和正常黏膜中進一步驗證芯片結果。最後我們就6個被帥選出來的microRNA在71例的膀胱癌患者和正常對照組的尿液上清中進行檢測並評估其診斷效能。我們發現,miR-125b和miR-99a的表達在膀胱癌患者的尿液上清中明顯下調。另外,它們下調程度與腫瘤的病理分級相關。結合miR-125b和miR-99b兩者作為診斷膀胱癌的指標,靈敏度達86.7%,特異度達81.1%,同時有陽性預測值達91.8%。當作為腫瘤分級指標,miR-125b具有81.4%的敏感度,87.0%的特異度,陽性預測值達93.4%。膀胱腫瘤切除之後,和術前比較,兩個microRNA的表達水平再度上升。我們將miR-99轉染到三個膀胱腫瘤細胞株中(T24,UMUC3和J82)。我們發現miR-99a對UMUC3細胞具有輕微的抗增殖功能。同時,miR-99a在3個細胞株中顯示均顯示具有抗遷移和抗侵襲能力。為尋找miR-99a的目標mRNA,我們結合數據庫算法預測,在Western blot中驗證到miR-99a能顯著下調VLDLR蛋白。隨後我們將帶有VLDLR的3'UTR質粒轉染進入細胞中并證實VLDLR mRNA是miR-99a直接作用的目標。另外,當VLDLR siRNA被轉入3個細胞株之後,我們觀察到相似的抗遷移和抗侵襲的現象。最後我們發現N-cadherin是該通路中的下游抑制遷移和侵襲的分子。本項研究證實研究尿液上清中的microRNA是可行的。MiR-125b和miR-99a是膀胱腫瘤的診斷和分級的有效指標。此外,miR-99a能夠通過和VLDLR mRNA直接結合從而抑制膀胱腫瘤遷移和侵襲功能。 / Urothelial carcinoma of the bladder (UCB) is the second most common malignancy in the urological system with high recurrence rate. Current gold standard examination for diagnosis is urethrocystoscopy, which is an invasive procedure. Although numerous molecular markers in blood or urine have been proposed as diagnostic biomarkers for bladder cancer, none of them could replace urethrocystoscopy in clinical practice. There are accumulating evidences suggesting microRNA dysregulation might be related to the pathogenesis of UCB. However, the exact functions of these microRNAs in UCB remain unknown. In this thesis, the role of selected microRNAs in urine supernatant was investigated in the diagnosis of UCB and also the carcinogenesis of UCB. / In brief, a high-throughput microarray was carried out on nine supernatants of urine from UCB and normal subjects, and also four pairs of tissue from UCB and normal mucosa. Ten microRNA candidates were then identified. Quantitative RT-PCR was used to validate these microRNAs on a set of 18 pairs of tumor tissue and normal mucosa. Eventually, six potential candidate microRNAs were selected and then validated as diagnostic tools on the samples of urine supernatants from 71 patients (50 of known UCB and 21 of normal subjects). The expression levels of these selected microRNAs were further evaluated in the urine supernatants of 20 patients after tumors resections. MiR-125b and miR-99a were the two most significantly down-regulated microRNAs in the urine supernatants of patients with UCB. Moreover, the degree of down-regulation was associated with the pathological grade of the tumor. A combined index of miR-125b and miR-99a in urine supernatant had a sensitivity of 86.7%, specificity of 81.1%, and a positive predicted value of 91.8% for diagnosing UCB. When used to discriminate high-grade from low-grade UCB, miR-125b alone had a sensitivity of 81.4%, specificity of 87.0% and PPV of 93.4%. After transurethral resections, the expression levels of both microRNAs were significantly increased compared to pre-operative levels. / In further studies on the role of microRNAs on the development of UCB, miR-99a was selected for further studies. The precursor of miR-99a was temporally transfected into 3 bladder cancer cell lines: T24, UMUC3 and J82. The proliferation ability was noticed to be suppressed mildly in UMUC3, but not the other. Meanwhile, migration and invasion abilities were inhibited by miR-99a in the all 3 cell lines. Potential targets of miR-99a were predicted from several prediction databases. Subsequently, in Western Blot study, the protein level of very low density lipoprotein receptor (VLDLR) was showed to be down-regulated by miR-99a. Thereafter, a plasmid constructed with 3’UTR of VLDLR was transfected into cytoplasm, which confirmed VLDLR mRNA was a direct target of miR-99a. All 3 cells lines showed the same effect on suppression of migration and invasion after knockdown of VLDLR. N-cadherin was identified as a down-stream molecule responsible for the migration and invasion suppression in this pathway. / This study confirmed microRNA expression in urine supernatants was a feasible approach for the assessment of biomarkers, and miR-125b and miR-99a showed promising results in the diagnosis and grading of UCB. Furthermore, we showed that miR-99a suppressed tumor migration and invasion by directly targeting VLDLR. / Detailed summary in vernacular field only. / Zhang, Dingzuan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 107-131). / Abstract and appendix also in Chinese. / Abstract --- p.I / 摘要 --- p.III / Acknowledgments --- p.V / Abbreviations --- p.VII / List of figures --- p.IX / List of Tables --- p.XI / Content --- p.XII / Chapter Chapter I: --- General Introduction / Chapter 1.1 --- Bladder cancer --- p.1 / Chapter 1.1.1 --- The incidence of bladder cancer / Chapter 1.1.2 --- The burden of bladder cancer to the health care system / Chapter 1.1.3 --- Risk factors for bladder cancer / Chapter 1.1.4 --- Pathology grading system in bladder cancer / Chapter 1.1.5 --- Current diagnostic methods and treatment for bladder cancer / Chapter 1.2 --- Biomarkers for bladder cancer --- p.7 / Chapter 1.2.1 --- The advantages of biomarkers in blood and urine for the diagnosis of bladder cancer / Chapter 1.2.2 --- Biomarkers in blood for bladder cancer / Chapter 1.2.3 --- Biomarkers in the urine for bladder cancer / Chapter 1.2.4 --- Current concerning problems with biomarkers / Chapter 1.3 --- MicroRNAs and bladder cancer --- p.11 / Chapter 1.3.1 --- Post-trancriptional function of microRNAs / Chapter 1.3.2 --- The function of microRNAs in tumor / Chapter 1.3.3 --- Prospects of detecting microRNA in cell-free fluid in tumor / Chapter 1.4 --- MicroRNA target identification --- p.15 / Chapter 1.4.1 --- Prediction of microRNA target / Chapter 1.4.2 --- Validation of microRNA target / Chapter 1.4.3 --- Validation of direct interaction between microRNA and target RNA / Chapter 1.4.4 --- Validation of direct binding of microRNA and mRNA in vivo / Chapter 1.5 --- Migration and invasion of bladder cancer --- p.19 / Chapter 1.5.1 --- The biological process of migration in bladder cancer / Chapter 1.5.2 --- Epithelial to mesenchymal transition in bladder cancer / Chapter 1.6 --- Objectives of this study --- p.21 / Chapter Chapter II --- MicroRNAs in urine supernatant: potential useful markers for bladder cancer screening / Chapter 2.1 --- Introduction --- p.23 / Chapter 2.2 --- Materials and methods --- p.26 / Chapter 2.2.1 --- Ethics Statement / Chapter 2.2.2 --- Patients and samples / Chapter 2.2.3 --- RNA extraction / Chapter 2.2.4 --- MicroRNA microarray / Chapter 2.2.5 --- Quantitative real-time polymerase chain reaction (RT-PCR) / Chapter 2.2.6 --- Statistical methods / Chapter 2.3 --- Results --- p.31 / Chapter 2.3.1 --- MicroRNA screening by microRNA microarray / Chapter 2.3.2 --- Independent validation of the ten selected microRNAs by qRT-PCR on tissue / Chapter 2.3.3 --- Verification of the six validated microRNAs in urine supernatants as tumor markers / Chapter 2.3.4 --- MiR-125b and miR-99a in urine supernatants were useful for the diagnosis of bladder cancer / Chapter 2. --- 3.5 MiR-125b and miR-99a were two highly correlated microRNAs / Chapter 2.3.6 --- Expression levels of miR-125b and miR-99a increased after tumor resection / Chapter 2.4 --- Discussion --- p.47 / Chapter Chapter III: --- MiR-99a suppresses migration and invasion in bladder cancer by targeting VLDLR / Chapter 3.1 --- Introduction --- p.53 / Chapter 3.2 --- Materials and methods --- p.56 / Chapter 3.2.1 --- Human tissue samples and bladder cancer cell lines / Chapter 3.2.2 --- RNA extraction and Polymerase Chain Reaction / Chapter 3.2.3 --- MicroRNA and plasmid transfection / Chapter 3.2.4 --- Western Immunoblotting / Chapter 3.2.5 --- Agarose gel electrophoresis / Chapter 3.2.6 --- Luciferase assay / Chapter 3.2.7 --- MTT proliferation assay / Chapter 3.2.8 --- Apoptosis assay / Chapter 3.2.9 --- Cell cycle analysis / Chapter 3.2.10 --- Cell migration Assay / Chapter 3.1.11 --- Cell invasion assay: / Chapter 3.2.12 --- Statistical methods: / Chapter 3.3 --- Results --- p.67 / Chapter 3.3.1 --- MiR-99a was significantly down-regulated in bladder cancer / Chapter 3.3.2 --- Precursor microRNA was successfully transfected into bladder cancer cell lines / Chapter 3.3.3 --- MiR-99a had little effect on cell proliferation / Chapter 3.3.4 --- MiR-99a had little effect on cell apoptosis and cell cycle / Chapter 3.3.5 --- Over-expression of miR-99a suppressed cell migration in bladder cancer / Chapter 3.3.6 --- Over-expression of miR-99a also suppressed invasion ability in bladder cancer / Chapter 3.3.7 --- Target prediction for miR-99a using 8 target prediction databases / Chapter 3.3.8 --- Protein level of VLDLR was down-regulated by miR-99a in bladder cancer / Chapter 3.3.9 --- VLDLR was a direct target of miR-99a / Chapter 3.3.10 --- VLDLR mRNA was not down-regulated correspondingly by miR-99a / Chapter 3.3.11 --- MiR-99a suppressed down-stream protein of VLDLR in Reelin pathway / Chapter 3.3.12 --- Knockdown of VLDLR also suppressed cell migration and invasion / Chapter 3.3.13 --- N-cadherin was the down-stream protein responsible for the suppression of migration and invasion in miR-99a/VLDLR pathway / Chapter 3.4 --- Discussion --- p.93 / Chapter Chapter IV: --- Conclusion and prospective --- p.101 / Appendix --- p.105 / Reference --- p.107
30

Induction of miR-765 by antiestrogen ICI 182,780 in prostate cancer cells. / 抗雌激素ICI 182,780對前列腺癌細胞中miR-765的誘導表達 / Kang ci ji su ICI 182,780 dui qian lie xian ai xi bao zhong miR-765 de you dao biao da

January 2011 (has links)
Tse, Ho Man. / Thesis (M.Phil)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 166-173). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / 撮要 --- p.v / Table of Content --- p.vi / Chapter Chapter 1: --- Introduction --- p.1 / Chapter 1.1 --- Basis of Prostate Cancer --- p.1 / Chapter 1.1.1 --- Epidemiology and Risk Factors of Prostate Cancer --- p.1 / Chapter 1.1.2 --- Pathology of Prostate Cancer --- p.2 / Chapter 1.1.3 --- Treatment Approaches for Prostate Cancer --- p.4 / Chapter 1.2 --- Sex Hormones and Prostate Cancer --- p.7 / Chapter 1.2.1 --- Prostate Development --- p.7 / Chapter 1.2.2 --- Involvement of Sex Hormones in Prostate Cancer --- p.8 / Chapter 1.2.3 --- Molecular Mechanisms of Sex Hormones --- p.13 / Chapter 1.2.4 --- Hormone Receptor Antagonists --- p.15 / Chapter 1.3 --- Involvement of microRNAs in Cancer --- p.19 / Chapter 1.3.1 --- Basis of microRNAs --- p.19 / Chapter 1.3.2 --- Aberrant microRNA Expressions in Cancers --- p.23 / Chapter 1.3.3 --- Current Understandings on Regulations of micro RN A Expressions --- p.26 / Chapter 1.3.4 --- Regulation of miRNA Expressions by Hormones --- p.29 / Chapter 1.4 --- "Effects of the Anti-estrogen ICI 182,780 on Prostate Cancer Cells" --- p.30 / Chapter 1.4.1 --- "ICI 182,780 Inhibits Cell Growth ofDU145" --- p.30 / Chapter 1.5 --- Objectives of Project --- p.32 / Chapter Chapter 2: --- Materials --- p.34 / Chapter 2.1 --- Bacteria Strain --- p.34 / Chapter 2.2 --- Tissue Culture Media --- p.34 / Chapter 2.3 --- Plasmids --- p.34 / Chapter 2.4 --- Kits and Accessories --- p.35 / Chapter 2.5 --- Reagents and Solutions --- p.36 / Chapter 2.6 --- DNA Oligos --- p.38 / Chapter 2.7 --- Equipments --- p.40 / Chapter Chapter 3: --- Methods --- p.41 / Chapter 3.1 --- Cell Culture Conditions --- p.41 / Chapter 3.2 --- miRNA Expression Profiling of DU145 --- p.41 / Chapter 3.2.1 --- RNA Isolation --- p.41 / Chapter 3.2.2 --- miRNA Microarray Profiling ofDU145 : --- p.42 / Chapter 3.2.2.1 --- Fluorescent Labeling of RNA and Microarray Hybridization --- p.42 / Chapter 3.2.2.2 --- Scanning and Analysis of Signals --- p.46 / Chapter 3.2.3 --- Confirming miR-765 Up-regulation by ICI with qRT-PCR --- p.46 / Chapter 3.2.3.1 --- Assessing ERp Dependency in miR-765 Induction --- p.48 / Chapter 3.2.4 --- Effects of ICI on ARHGEF11 Expression --- p.49 / Chapter 3.2.4.1 --- Reverse Transcription of mRNA --- p.50 / Chapter 3.2.4.2 --- Quantitative Real-Time PCR for Gene mRNA expression --- p.50 / Chapter 3.3 --- Characterizing the Promoter Region of miR-765 --- p.52 / Chapter 3.3.1 --- Cloning of miR-765 Promoter into pGL3-Basic Vector --- p.52 / Chapter 3.3.1.1 --- PCR Amplification of miR-765 Putative Promoter Region --- p.52 / Chapter 3.3.1.2 --- Ligation of the Amplified Regions in pGL3-Basic Vector --- p.55 / Chapter 3.3.1.3 --- Transformation and Screening of pGL3-765 Plasmid --- p.57 / Chapter 3.3.1.4 --- Preparation of pGL3-765 Plasmid DNA --- p.59 / Chapter 3.3.2 --- Preparation of Truncated miR- 765 Promoter Clones --- p.60 / Chapter 3.3.2.1 --- pGL3-765-Trunc#l --- p.61 / Chapter 3.3.2.2 --- pGL3-765-Trunc#2 --- p.62 / Chapter 3.3.2.3 --- pGL3-765-Trunc#3 --- p.62 / Chapter 3.3.3 --- Assessing the miR- 765 Promoter Activities --- p.63 / Chapter 3.3.3.1 --- Optimizing Transfection Conditions --- p.64 / Chapter 3.3.3.2 --- Co-transfection of pGL3-765 and pRL-CMV into DU145 Cells.. --- p.64 / Chapter 3.3.3.3 --- Measuring Luciferase Activities --- p.65 / Chapter 3.3.4 --- Computational Prediction of Transcription Factor Binding Sites on miR-765 Promoter --- p.66 / Chapter 3.4 --- Characterizing the Promoter Region of ARHGEF11.. --- p.67 / Chapter 3.4.1 --- Cloning of ARHGEF11 Promoter into pGL3-Basic Vector (pGL3-ARH) --- p.67 / Chapter 3.4.1.1 --- PCR Amplification of ARHGEF11 Putative Promoter Region --- p.67 / Chapter 3.4.1.2 --- Ligation of the Amplified Regions in pGL3-Basic Vector --- p.68 / Chapter 3.4.1.3 --- Preparation of Plasmid DNA --- p.69 / Chapter 3.4.2 --- Preparation of Truncated ARHGEF11 Promoter Clones --- p.69 / Chapter 3.4.2.1 --- pGL3-ARH-Trunc#l --- p.69 / Chapter 3.4.2.2 --- pGL3-ARH-Trunc#2 --- p.70 / Chapter 3.4.2.3 --- pGL3-ARH-Trunc#3 --- p.71 / Chapter 3.4.3 --- Assessing ARHGEF11 Promoter Activities --- p.72 / Chapter 3.5 --- Identifying Transcription Factor Binding Sites on ARHGEF11 Promoter with EMS A --- p.73 / Chapter 3.5.1 --- Computational Prediction --- p.73 / Chapter 3.5.2 --- Preparation of Biotinylated Probe for use in EMSA --- p.73 / Chapter 3.5.3 --- Preparation of Specific Competitors --- p.74 / Chapter 3.5.4 --- Preparation of DU145 Nuclear and Cytoplasmic Extracts --- p.75 / Chapter 3.5.4.1 --- Preparation of Extracts --- p.75 / Chapter 3.5.4.2 --- Measuring Protein Concentrations --- p.76 / Chapter 3.5.5 --- EMSA Detection of Interaction between Protein and Probe --- p.76 / Chapter 3.6 --- Assessing Biological Significances of miR-765 --- p.78 / Chapter 3.6.1 --- Effects of ICI on DU145 Cells Growth --- p.79 / Chapter 3.6.2 --- Effects of ICI on DU145 Migration Ability --- p.79 / Chapter 3.6.2.1 --- Monolayer Wound Healing Assay --- p.79 / Chapter 3.6.2.2 --- Transwell Migration Assay --- p.80 / Chapter 3.6.3 --- Validating Functionality of Ectopic miR- 765 --- p.81 / Chapter 3.6.3.1 --- miR-765 Recognition Sequence --- p.81 / Chapter 3.6.3.2 --- Preparation of pMIR-765 vector --- p.82 / Chapter 3.6.3.3 --- Ectopic Introduction of miR-765 into DU145 Cells --- p.84 / Chapter 3.6.3.4 --- "Verifying Functionality, of Ectopic miR-765" --- p.84 / Chapter 3.6.4 --- Effects of miR-765 on DU145 Growth --- p.86 / Chapter 3.6.5 --- Effects of miR-765 on DU145 Migration Ability --- p.86 / Chapter 3.7 --- Statistical Analysis --- p.87 / Chapter Chapter 4: --- Results --- p.88 / Chapter 4.1 --- "Identifying ICI 182,780-Regulated miRNA in DU145 Cells" --- p.88 / Chapter 4.1.1 --- miRNA Expression Profiling of DU145 with Microarray --- p.88 / Chapter 4.1.2 --- "Confirming Induction of miR-765 by ICI 182,780 with qRT-PCR" --- p.91 / Chapter 4.1.3 --- "ARHGEF11, Host Gene of miR-765" --- p.95 / Chapter 4.1.4 --- "Induction of ARHGEF 11 by ICI 182,780" --- p.96 / Chapter 4.2 --- Characterization miR-765 Promoter Region --- p.98 / Chapter 4.2.1 --- Cloning of miR- 765 Promoter Region into pGLS-Basic Vector --- p.98 / Chapter 4.2.2 --- Promoter Activity of miR-765 Promoter --- p.100 / Chapter 4.2.3 --- Deletion Mapping of miR- 765 Promoter Region --- p.102 / Chapter 4.2.4 --- Promoter Activities and Inducibitiy of Truncated miR-765 Promoters --- p.103 / Chapter 4.2.5 --- Computational Prediction of Transcription Factor Binding Sites on miR-765 Promoter --- p.105 / Chapter 4.3 --- Characterization of ARHGEF 11 Promoter Region --- p.107 / Chapter 4.3.1 --- Cloning of ARHGEF 11 Promoter --- p.107 / Chapter 4.3.2 --- Promoter Activitiy of ARHGEFll Promoter --- p.109 / Chapter 4.3.3 --- Deletion Mapping of ARHGEFll Promoter --- p.111 / Chapter 4.3.4 --- Promoter Activities and Inducibitiy of Truncated ARHGEF 11 Promoters --- p.113 / Chapter 4.4 --- Identifying Transcription Factor Binding Sites on ARHGEF 11 Promoter --- p.115 / Chapter 4.4.1 --- Computational Prediction of Transcription Factor Binding Sites onARHGEFll Promoter --- p.115 / Chapter 4.4.2 --- Preparation of Probe and Specific Competitors for EMSA --- p.117 / Chapter 4.4.3 --- Interaction between DU145 Nuclear Extract and ARHGEF 11 Promoter Region --- p.119 / Chapter 4.5 --- Biological Significances of miR-765 --- p.122 / Chapter 4.2.1 --- "Effects of ICI 182,780 on DU145 Cell growth" --- p.122 / Chapter 4.2.2 --- "Effects of ICI 182,780 on DU145 Cell Migration" --- p.124 / Chapter 4.2.3 --- Verifying Functionality of Ectopic miR-765 --- p.131 / Chapter 4.2.4 --- Effects of miR-765 on DU145 Cell Growth --- p.133 / Chapter 4.2.5 --- Effects of miR-765 on DU145 Cell Migration --- p.135 / Chapter Chapter 5: --- Discussion --- p.138 / Chapter 5.1 --- "Identifying miR-765 as an Up-regulated miRNA by ICI 182,780" --- p.139 / Chapter 5.1.1 --- "Information about ICI 182,780" --- p.139 / Chapter 5.1.2 --- miRNA Profiling of DU145 --- p.139 / Chapter 5.1.3 --- "Confirming Induction of miR-765 by ICI 182,780 and ERβ dependency with qRT-PCR" --- p.140 / Chapter 5.1.4 --- "Up-regulation of miR-765 Host Gene, ARHGEF11, by ICI" --- p.141 / Chapter 5.2 --- Regulatory Elements of miR-765 Expression --- p.143 / Chapter 5.2.1 --- Own Upstream promoter of miR- 765 --- p.144 / Chapter 5.2.2 --- Promoter of Host Gene ARHGEF11 --- p.146 / Chapter 5.2.3 --- Interaction between ARHGEF11 Promoter Critical Region and Transcription Factors --- p.147 / Chapter 5.2.4 --- Involvement of independent Promoter and Host Gene Promoter in miR-765 Regulation --- p.757 / Chapter 5.3 --- Biological Significances of miR-765 on DU145 --- p.153 / Chapter 5.4 --- Significance of Findings and Future Studies --- p.158 / Chapter 5.4.1 --- Clinical Significance --- p.158 / Chapter 5.4.2 --- Future Studies --- p.161 / Chapter Chapter 6: --- Conclusion --- p.163 / Chapter Chapter 7: --- References --- p.166

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