Chu Wai Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 87-96). / Abstracts in English and Chinese. / Acknowledgments --- p.ii / Publication --- p.iii / List of Abbreviations --- p.iv / List of Tables --- p.v / List of Figures --- p.vi / Abstract --- p.vii / 摘要 --- p.x / Table of Contents --- p.xii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Epidemiology of gastric cancer --- p.1 / Chapter 1.2 --- Risk factors associated with gastric cancer --- p.7 / Chapter 1.3 --- Prevention of Gastric Cancer --- p.9 / Chapter 1.4 --- H. pylori eradication and gastric cancer development --- p.11 / Chapter 1.5 --- Non-steroidal anti-inflammatory drugs and gastric cancer prevention --- p.13 / Chapter 1.6 --- COX-2 independent pathway --- p.14 / Chapter 1.7 --- Animal model of gastric cancer --- p.15 / Chapter 1.8 --- Microarray system --- p.16 / Chapter 1.9 --- Hypothesis --- p.18 / Chapter 1.10 --- Aim of study --- p.19 / Chapter Chapter 2 --- Chemoprevention of gastric cancer by celecoxib --- p.20 / Chapter 2.1 --- Introduction --- p.20 / Chapter 2.2 --- Material and Methods --- p.22 / Chapter 2.2.1 --- Animals --- p.22 / Chapter 2.2.2 --- Chemicals --- p.22 / Chapter 2.2.3 --- Study design --- p.23 / Chapter 2.2.4 --- Cell Culture --- p.24 / Chapter 2.2.5 --- Celecoxib treatment --- p.24 / Chapter 2.2.6 --- Cell proliferation assay --- p.25 / Chapter 2.3 --- Results --- p.26 / Chapter 2.3.1 --- Chemoprevention of gastric cancer by celecoxib in rats --- p.26 / Chapter 2.3.2 --- Effects of celecoxib on growth of human gastric cancer cells --- p.29 / Chapter 2.4 --- Discussion --- p.30 / Chapter 2.4.1 --- MNNG induced gastric cancer effectively --- p.30 / Chapter 2.4.2 --- Celecoxib significantly suppressed gastric carcinogenesis in rats --- p.31 / Chapter 2.4.3 --- Celecoxib inhibited the growth of MKN 45 in a concentration-dependent manner --- p.31 / Chapter 2.4.4 --- Celecoxib may exert its anti-tumor property through COX independent pathway --- p.32 / Chapter Chapter 3 --- Gene expression profiles of celecoxib treated rat gastric tumor and human gastric cells --- p.34 / Chapter 3.1 --- Introduction --- p.34 / Chapter 3.2 --- Material and Methods --- p.34 / Chapter 3.2.1 --- RNA extraction --- p.34 / Chapter 3.2.2 --- Target preparation and Array hybridization --- p.35 / Chapter 3.2.3 --- Post-hybridization processing and Scanning --- p.36 / Chapter 3.2.4 --- Microarray data analysis --- p.36 / Chapter 3.2.5 --- Quantitative RT-PCR --- p.37 / Chapter 3.3 --- Results --- p.39 / Chapter 3.3.1 --- Gene expression profiles of rat gastric tumors --- p.39 / Chapter 3.3.1.1 --- Genes differentially expressed in MNNG induced gastric tumors --- p.39 / Chapter 3.3.1.2 --- Genes differentially expressed in celecoxib treated group --- p.42 / Chapter 3.3.1.3 --- Mechanisms underlying chemoprevention of celecoxib --- p.43 / Chapter 3.3.2 --- Verification of gene expression by quantitative RT-PCR --- p.55 / Chapter 3.3.3 --- Confirmation of the gene expression profiles in human by quantitative RT-PCR --- p.59 / Chapter 3.4 --- Discussions --- p.63 / Chapter Chapter 4 --- Effects of celecoxib on Akt pathway in gastric cancer cells --- p.68 / Chapter 4.1 --- Introduction --- p.68 / Chapter 4.2 --- Material and methods --- p.72 / Chapter 4.2.1 --- Protein extraction --- p.72 / Chapter 4.2.2 --- Western blotting --- p.72 / Chapter 4.3 --- Results --- p.74 / Chapter 4.3.1 --- Expression of the Akt pathway after treatment with celecoxib --- p.74 / Chapter 4.4 --- Discussions --- p.78 / Chapter Chapter 5 --- Conclusion --- p.82 / References --- p.87