Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

Objetivos. Describir las características histológicas y endoscópicas que se presentan en pacientes diagnosticados con cáncer gástrico en el Hospital Nacional Daniel Alcides Carrión del Callao. Materiales y métodos. Se realizó un estudio tipo serie de casos que incluyó a todos los pacientes con diagnóstico histológico de cáncer gástrico durante el periodo de enero de 2009 a diciembre de 2011. La información se obtuvo de los registros del servicio de anatomía patológica del Hospital Nacional Daniel Alcides Carrión. Se consignó la edad y sexo de los pacientes, el tipo histológico, la localización endoscópica, así como la presencia de metaplasia intestinal, el grado histológico y la morfología del cáncer. Resultados. Se incluyeron 120 pacientes. La edad promedio fue de 65,4 ± 13,6 años; 59 (49%) fueron de sexo masculino. Según el tipo histológico se encontró el tipo intestinal en 68 (56%); difuso en 45 (38%), y mixto en 7 (6%). Según su localización, 23 (19%) se localizaron en fondo; 52 (43%) en el cuerpo; 39 (33%) en el antro, y 6 (5%) en el píloro. Los pacientes con cáncer gástrico de tipo intestinal presentaron una edad promedio mayor que los que tuvieron el tipo difuso (69,1 ± 10,3 versus 59,3 ± 15,3). De los pacientes con cáncer gástrico tipo intestinal, 60,3% tuvo localización proximal, en comparación a 66,6% de los pacientes con tipo difuso. Conclusión. En la población en estudio, el cáncer gástrico de tipo difuso se presenta a una edad más temprana que el de tipo intestinal, además de estar más frecuentemente localizados a nivel proximal. / Objetivos. To describe the histologic and endoscopic characteristics reported among patients diagnosed with gastric cancer in “Daniel Alcides Carrion” National Hospital in Callao. Materials and methods. We performed a case series including all patients with histological diagnosis of gastric cancer from January 2009 to December 2011. Data were obtained from the registers of the pathology service of Daniel Alcides Carrion National Hospital. Factors such as age and gender of patients, histologic type, endoscopic location, presence of intestinal metaplasia, histologic degree, and cancer morphology were evaluated. Results. 120 patients were included. Mean age was 65.4 ± 13.6 years; 59 (49%) were male. Based on the histologic type, intestinal type was found among 68 (56%); diffuse type among 45 (38%), and a mixed type in 7 (6%). Regarding the site, 23 (19%) of gastric cancers were located in the fundus; 52 (43%) in the body; 39 (33%) in the antrum, and 6 (5%) in the pylorus. Patients with gastric cancer of the intestinal type were in average older than those with a diffuse type (69.1 ± 10.3 versus 59.3 ± 15.3). 60.3% of intestinal-type gastric cancers were located proximally, versus 66.6% of diffuse-type cancers. Conclusion. Among the studied population, diffuse-type gastric cancer appears at an earlier age than the intestinal type, and its most common location is proximal.

INTRODUÇÃO: o câncer de estômago já foi, mundialmente, a neoplasia com maior ocorrência na população. Ao longo das décadas, a incidência deste câncer apresenta tendência de decréscimo significativo, sendo que, atualmente, é o quinto tumor maligno mais frequente no mundo. A mortalidade não acompanhou a tendência de decréscimo na mesma velocidade e ainda é considerada a terceira principal causa de morte por câncer. O Brasil acompanhou a tendência mundial, registrando o declínio significativo da incidência e da mortalidade. O município de São Paulo apresenta as mais altas taxas de incidência e mortalidade do país. Apesar disso, existem poucos estudos de tendências de incidência dessa neoplasia para São Paulo e este é o primeiro estudo que investiga as tendências de incidência e mortalidade por sexo, por faixas etárias e por tipo histológico. OBJETIVO: analisar as tendências dos coeficientes de incidência e mortalidade do câncer de estômago, segundo sexo, faixa etária e tipo histológico pela classificação de Lauren. MÉTODOS: estudo ecológico de séries temporais. Foram analisados os novos casos de câncer de estômago, diagnosticados no período de 1997 a 2011, no município de São Paulo, cadastrados no Registro de Câncer de Base Populacional de São Paulo, e os óbitos por câncer de estômago do período de 1980 a 2011, de residentes no Município de São Paulo, obtidos do site do Departamento de Informática do Sistema Único de Saúde (DATASUS) do Ministério da Saúde. Foram feitas análises de séries temporais por sexo, faixa etária e tipo histológico utilizando a classificação de Lauren. Os coeficientes brutos e padronizados foram calculados e utilizados nas análises de tendências, através dos modelos de regressão linear e do cálculo da mudança percentual anual (APC). RESULTADOS: foram analisados 24.512 casos incidentes e 31.215 óbitos. Houve redução da incidência (APC -8,3 por cento em homens e -6,5 por cento em mulheres) e da mortalidade (APC -2,3 por cento em homens e -2,5 por cento em mulheres). Houve tendência de queda em todas as faixas etárias, com exceção da faixa etária mais jovem (20-29 anos), que apresentou estabilidade da incidência e da mortalidade. A estabilidade na faixa etária mais jovem também foi identificada nos tipos intestinal e difuso. O tipo difuso apresentou estabilidade também nas faixas etárias: 30-39, 40-49 e 80 anos do sexo feminino. CONCLUSÃO: São Paulo acompanhou a tendência mundial de decréscimo na incidência e na mortalidade, entretanto, a mesma tendência não foi observada entre adultos jovens, principalmente a faixa etária de 20 a 29 anos. Atenção especial deve ser dada ao tipo difuso, que não apresentou queda na tendência de incidência do câncer de estômago para as mulheres de 20 a 49 anos. / INTRODUCTION: the stomach cancer was once considered as the most incident neoplasm worldwide. Over the decades, the stomach cancer incidence has been showing a significant decreasing trend, and is currently the fifth most common malignancy in the world. Mortality has not followed this decreasing trend at the same speed and is still considered the third leading cause of cancer death. Brazil follows this global trend, having a significant decline both in incidence and mortality. Across the regions of Brazil, the city of São Paulo has one of the highest incidence and mortality rates. Nevertheless, there are few studies on trends of this neoplasm in Sao Paulo and this is the first study to investigate the trends of incidence and mortality by sex, age group and histological type. OBJECTIVE: to analyze the trends in stomach cancer incidence and mortality, according to gender, age group and histological type of Lauren\'s classification. METHODS: this is an ecological time-series study. We analyzed the new cases of stomach cancer diagnosed between 1997 and 2011 in São Paulo registered in the Population Based Cancer Registry of São Paulo and deaths from stomach cancer from 1980 to 2011, in the city of São Paulo, obtained from the Ministry of Health website - Department of the Unified Health System (DATASUS). Time series analyzes were performed by gender, age group and histological type using the Lauren classification of intestinal-type and diffuse type. Crude and agestandardized rates were calculated and used in time trend analysis, through linear regression models and the annual percentage change (APC). RESULTS: we analyzed 24,512 incident cases and 31,215 deaths. There was a reduction in the incidence (APC -8.3 per cent men and -6.5 per cent women) and mortality (APC -2.3 per cent men and 2.5 per cent women). A decreasing trend was observed for all age groups, except for the youngest (20-29 years) for which stability was observed. Both intestinal and diffuse types remained stable in the youngest age group. The diffuse type was stable also in the age groups: 30-39, 40-49 and 80 years female. CONCLUSION: São Paulo followed the global trend of decrease in incidence and mortality, however, the same trend was not observed among young adults, especially the age group 20-29 years. Special attention should be given to diffuse type that showed no reduction in the incidence trend of stomach cancer for women 20-49 years female.

INTRODUÇÃO: O câncer gástrico precoce que invade a submucosa pode apresentar acometimento linfonodal em torno de 20% dos casos. O tratamento cirúrgico clássico com gastrectomia e linfadenectomia D2 é um procedimento não isento de mortalidade e morbidade. Determinar quais pacientes têm maior risco de acometimento linfonodal permitiria tratamentos com menores complicações. Recentemente diversos autores relatam maior expressão imuno-histoquímica de p53 e p21ras em tumores avançados e com pior prognóstico. Tem sido relatada também perda da expressão de p21waf1, p27kip1 e p16ink4a nos tumores avançados e algumas publicações relatam também relação entre a expressão dos marcadores e acometimento linfonodal. MÉTODOS: Foram estudados retrospectivamente 81 pacientes submetidos à gastrectomia com linfadenectomia D2 no período de 1971 a 2004 no Serviço de Cirurgia do Estômago e Intestino Delgado do Departamento de Gastroenterologia do HC-FM/USP. Os blocos de parafina contendo fragmentos dos tumores foram recuperados e novo exame histopatológico confirmou o diagnóstico. Selecionaram-se áreas representativas de mucosa normal, mucosa metaplásica e tumor para confecção de novos blocos de tissue microarrays. Foi avaliada a expressão imuno-histoquímica de p21ras, p53, p21waf1/cip1, p27kip1 e p16ink4a nos tecidos. Foram investigadas as correlações entre a expressão dos marcadores e as características clínico-patológicas dos pacientes. A análise da associação entre os dados clínicos e a positividade dos marcadores foi realizada pelo teste Qui-quadrado. RESULTADOS: Na mucosa normal, metaplásica e tumoral p53 apresentou positividade em 53%, 87,3% e 87,1% dos casos respectivamente. Nos mesmos tecidos p21ras apresentou positividade de 85,3%, 86% e 96,8%. Para p16ink4a a positividade foi de 46,3%, 91,1% e 86%. Para p27kip1 a positividade foi de 60%, 94,7% e 95,3%. Para p21waf1/cip1 a positividade foi 32,4%, 72,7% e 71,4%. Todos os tumores tiveram alguma positividade para p53. Os tumores com acometimento linfonodal apresentaram hiper-expressão(+4) de p53 em 47% dos casos contra 17% nos pacientes que não tinham acometimento. Nenhum tumor com positividade para p53 baixa(0 e +1) teve linfonodos acometidos. Nenhum tumor com p21ras negativo apresentou linfonodos acometidos. Nos pacientes com acometimento linfonodal p21ras teve positividade intensa(+2 e +3) em 88% dos casos contra 50% dos casos sem acometimento linfonodal. Houve positividade intensa(+2,+3 e +4) de p21waf1/cip1 em 71% dos tumores com acometimento linfonodal contra 28% nos pacientes sem acometimento. Não observamos perda de expressão de p21waf1, p27kip1 e p16ink4a nos tumores com acometimento linfonodal. Na mucosa normal p16ink4a foi hiper-expresso (+4) em 20% dos casos com infiltração perineural contra 0% nos casos sem acometimento. O mesmo marcador foi hiperexpresso em 50% dos casos com infiltração vascular contra 0% dos casos sem infiltração. Os tumores com padrão de infiltração Sm2 tiveram pouca positividade(0 e +1) de p27kip1 na mucosa normal em 89% dos casos contra 55% dos casos Sm1. CONCLUSÕES: Maior expressão de p53, p21ras e p21waf1/cip1 no tumor teve relação estatística significante com acometimento linfonodal. Ocorre aumento da expressão imuno-histoquímica de todos os marcadores da mucosa normal para o tumor. A maior hiper-expressão de p16ink4a na mucosa normal de pacientes tem relação com infiltração perineural e vascular nos tumores. A expressão dos marcadores é diferente nas raças estudadas. As pacientes do sexo feminino apresentam maior positividade de p21waf1 na mucosa normal. Pacientes com história familiar de câncer gástrico apresentam maior positividade de p16ink4a na mucosa normal, menor positividade de p21waf1/cip1 e p21ras na mucosa metaplásica. Maior positividade na mucosa normal de p21waf1/cip1 relaciona-se a sexo feminino e infiltração tipo Sm1 / INTRODUCTION: Early gastric cancer that invades the submucosa might have a lymphonodal involvement in about 20% of the cases. Gastrectomy and D2 linfadenectomy is a procedure that has presented mortality and morbidity. Determining which patients would have a greater risk of lymphonodal involvement would allow treatments with fewer complications. Recently, several authors reported a greater immunohistochemical expression of p53 and p21ras in advanced tumors with worst prognosis. It has also been reported the expression loss of p21wafl, p27kip1, and p16ink4a in advanced tumors, and, some studies also observed the relationship between the markers expression and lymphonodal involvement. METHODS: Eightyone patients who had undergone gastrectomy with D2 linfadenectomy from 1971 to 2004 were retrospectively studied. A new histopathological exam confirmed the diagnosis. Representative areas of both normal and metaplastic mucosa and of the tumor were selected for obtaining new blocks of tissue microarrays. The immunohistochemical expression of p21ras, p53, p21waf1/cip1, p27kip1 and p16ink4a in the tissues was evaluated. RESULTS: In normal, metaplastic and tumoral mucosa, p53 showed positivity in 53%, 87.3%, and 87.1% of the cases, respectively. In the same tissues, p21ras showed positivity in 85.3%, 86%, and 96.8%, respectively. The positivity of p16ink4a was 46.3%, 91.1%, and 86%, respectively. p27kip1 showed a positivity of 60%, 94.7%, and 95.3%, respectively. p21wafl/cip1 presented a positivity of 32.4%, 72.7%, and 71.4%, respectively. All tumors showed positivity for p53. Tumors with lymphonodal involvement presented hyperexpression (+4) of p53 in 47% of the cases versus 17% in patients who had not showed any involvement. No tumor with low positivity (0 and +1) of p53 showed lymphonodal involvement. No tumor with negative p21ras showed lymphonodal involvement. In patients with lymphonodal involvement, p21ras presented strong positivity (+2 and +3) in 88% of the cases versus 50% of the cases without lymphonodal involvement. There was a strong positivity (+2,+3, and +4) of p21wafl/cip1 in 71% of the tumors with lymphonodal involvement versus 28% in patients without involvement. It was not observed an expression loss of p21waf1, p27kip1 e p16ink4a in tumors with lymphonodal involvement. In normal mucosa, p16ink4a showed a hyper-expression (+4) in 20% of the cases with perineural invasion versus 0% of the cases without invasion. This same marker showed a hyper-expression in 50% of the cases with vascular invasion versus 0% of the cases without invasion. Tumors with Sm2 invasion pattern showed low positivity (0 and +1) of p27kip1 in normal mucosa in 89% of the cases versus 55% of the cases of Sm1 tumors. CONCLUSIONS: Higher expression of p53, p21ras, and p21wafl/cip1 in tumor showed a significant statistical relationship with lymphonodal involvement. A higher hyper-expression of p16ink4a in patients normal mucosa was related to perineural and vascular invasion of tumors

No câncer gástrico, o foco do tratamento é a sobrevida, entretanto, para tumores avançados nos quais a indicação da cirurgia apresenta controversias, a qualidade de vida após o tratamento tornou-se importante. O pêso dos sintomas influencia a qualidade de vida e a sobrevida. Os sintomas são relacionados a doença de base, ao tratamento realizado, as co-morbidades associadas ou a combinação de fatores. A avalia-se a qualidade de vida no pré e pós-operatório de gastrectomia através dos questionários QLQC30 (qualidade global, escalas funcionais, escalas de sintomas) e STO22 (escalas de sintomas e itens isolados), associado a escalas funcionais de Karnofsky e Zubrod, além das escalas visuais analógicas e numérica para dor no pré e no primeiro e terceiro mês de pós-operatório. As análises de ambos os questionários não mostraram diferença estatística entre o pré-operatório e o primeiro e terceiro mês de pósoperatório. A escala funcional de karnofsky mostrou melhora da função fisica no primeiro mês de pós-operatório sem diferença com o terceiro mês, enquanto a de Zubrod não mostrou diferenças. A avaliação da dor não mostrou difernça com pós-operatório. A gastrectomia no câncer gástrico estádio III e IV não piora a qualidade de vida e pode ser realizada nos pacientes com perspectiva de sobrevida maior que um mês. / The aim of the treatment is survival when concerning gastric cancer. In those advanced gastric tumors whose surgical indications stay controversial, the Quality-oflife after treatment turned out to be very important. Symptoms are related to the disease. The scoring of symptoms has influence on the Quality-of-life and survival itself. Symptoms are related to the previous disease, chosen treatment and to the comorbidity associated with a combination of factors. One can evaluate the Quality-f-life before and after surgery through questionnaire QLQ-C30 (global quality, functional scales, grades of symptoms) and STO22 (grade of symptoms and isolate data) associated with functional gradation of Karnofsky and Zubrod. The visual analogical scales as well as the numeric one for the pain before and one month after surgery may be used too. For the questionnaire QLQ-C30 and STO22 the quality of life presents no differences to the pre operative status comparing with the post operative on first and third month. Karnofsky function after surgery are better on the first month and present no differences to the third month and the Zubrod showed no difference when compared to each other. The evaluation of pain showed no difference after surgery and no statistic significance in this item. The gastrectomy on gastric cancer stage III and IV dont worst the quality of life and perhaps may be have on patients with survive more than a month.

Lam, Man Ting. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 128-138). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Wang, Shiyan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 123-139). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

by Chan Ka Lee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 94-112). / Abstracts in English and Chinese. / Acknowledgements --- p.i / abstract(english/chinese) --- p.iii / Contents --- p.vii / List of Tables --- p.xi / List of Figures --- p.xii / Chapter I --- Introduction --- p.1 / Chapter I.1 --- Gastric Lymphoma --- p.1 / Chapter I.1.1 --- Background --- p.1 / Chapter I.1.2 --- Mucosa-Associated Lymphoid Tissue --- p.2 / Chapter I.1.3 --- Classification of Primary Gastric Lymphomas --- p.3 / Chapter I.1.3.1 --- Mucosa-Associated Lymphooid Tissue Type Lymphomas --- p.3 / Chapter I.1.3.2 --- High Grade Primary Gastric Lymphomas --- p.5 / Chapter I.1.3.3 --- Other Gastric Lymphomas --- p.7 / Chapter I.2 --- Helicobater Pylori --- p.8 / Chapter I.3 --- Epstein-Barr Virus --- p.9 / Chapter I.3.1 --- Epidemiology --- p.9 / Chapter I.3.2 --- Virus and Genome Structure --- p.9 / Chapter I.3.3 --- Latent Infection --- p.11 / Chapter I.3.4 --- Latent Membrane Protein-1 --- p.12 / Chapter I.3.5 --- "EBV-Encoded, Small Non-polydenylated RNAs (EBERs)" --- p.13 / Chapter I.3.6 --- Disease Associated with EBV --- p.13 / Chapter I.3.7 --- EBV and PGL --- p.14 / Chapter I.4 --- Genetic Alterations --- p.15 / Chapter I.4.1 --- Background --- p.15 / Chapter I.4.2 --- Tumor Suppressor Genes (TSGs) --- p.16 / Chapter I.4.2.1 --- Origin and Structure of p53 Gene and Protein --- p.16 / Chapter I.4.2.2 --- Functions of p53 Gene --- p.18 / Chapter I.4.2.3 --- Inactivation Mechanisms of p53 --- p.21 / Chapter I.4.2.4 --- p53 Mutations and Protein Expression in NHLs --- p.24 / Chapter I.4.3 --- Oncogene --- p.25 / Chapter I.4.3.1 --- Bcl-2 --- p.25 / Chapter I.4.3.2 --- Other Oncogenes --- p.27 / Chapter II --- OBJECTIVES OF STUD Y --- p.30 / Chapter III --- ma terials and methods --- p.31 / Chapter III.1 --- Materials --- p.31 / Chapter III.2 --- Detection of EB V Latent Gene Product by In-situ Hybridization --- p.33 / Chapter III.2.1 --- Pretreatment of Paraffin-embedded Tissues and Apparatus --- p.33 / Chapter III.2.2 --- In-situ Hybridization of EBERs --- p.34 / Chapter III.3 --- Detection of p53 and bcl-2 and LMP-1 Protein Expression by Immunohisiochemistry --- p.35 / Chapter III.4 --- Microdissection of Formalin-fixed Paraffin-embedded Tissues --- p.37 / Chapter III.5 --- Extraction of Genomic DNA from Formalin-fixed Paraffin-embedded Tissues --- p.38 / Chapter III.5.1 --- Phenol / Chloroform Extraction --- p.38 / Chapter III.5.2 --- Commercially Available DNA Extraction Kit --- p.40 / Chapter III.6 --- Mutational Analysis p53 --- p.41 / Chapter III.6.1 --- Polymerase Chain Reaction - Single Strand Conformation Polymorphism (PCR-SSCP) Analysis --- p.41 / Chapter III.6.1.1 --- PCR primers --- p.41 / Chapter III.6.1.2 --- PCR Amplification ofp53 gene --- p.42 / Chapter III.6.1.3 --- Non-denaturing Polyacrylamide Gel Electrophoresis --- p.42 / Chapter III.6.2 --- DNA Sequencing Analysis --- p.44 / Chapter III.6.2.1 --- Purification of DNA from Shifts on Non-denaturing Gels --- p.44 / Chapter III.6.2.2 --- 5' end Labeling of Primer --- p.45 / Chapter III.6.2.3 --- Cycle Sequencing --- p.45 / Chapter III.6.2.4 --- Denaturing Gel Electrophoresis --- p.46 / Chapter III.7 --- Loss of Heterozygosity (LOH) Analysis on Chromosome 17p --- p.47 / Chapter III.7.1 --- Microsatellite Markers --- p.49 / Chapter III.7.2 --- PCR Amplification of DNA Fragments Containing Polymorphic Microsatellites --- p.49 / Chapter III.7.3 --- Denaturing Polyacrylamide Gel Electrophoresis --- p.50 / Chapter III.7.4 --- Determination of Allelic Abnormalities --- p.51 / Chapter III. 8 --- Statistical Analysis --- p.52 / Chapter IV --- results --- p.53 / Chapter IV.1 --- Association with Helicobactor Pylori (HP) --- p.53 / Chapter IV.2 --- Detection of EBERs by ISH --- p.53 / Chapter IV.3 --- Immunohistochemical Analysis --- p.54 / Chapter IV.3.1 --- Protein Expression of EBV LMP-1 --- p.54 / Chapter IV.3.2 --- Protein Expression of p53 --- p.54 / Chapter IV.3.3 --- Protein Expression of bcl-2 --- p.55 / Chapter IV.3.4 --- Correlation between p53 and bcl-2 Protein Expression --- p.55 / Chapter IV.4 --- Mutational Analysis of p53 --- p.56 / Chapter IV.5 --- LOH Analysis on Chromosome 17p --- p.57 / Chapter V --- DISCUSSION --- p.58 / Chapter V.1 --- Helicobactor Pylori Association --- p.58 / Chapter V.2 --- Association with EE V --- p.60 / Chapter V.3 --- Protein Expression of p53 and bcl-2 --- p.61 / Chapter V.3.1 --- p53 --- p.61 / Chapter V.3.2 --- Bcl-2 --- p.62 / Chapter V.3.3 --- Correlation between p53 and bcl-2 Expression --- p.63 / Chapter V.4 --- p53 Gene Molecular Analysis --- p.65 / Chapter V.5 --- Distribution of Mutations and Molecular Fingerprinting --- p.67 / Chapter V.6 --- Possible Role of p53 Mutation in EBV+ Gastric Lymphomas --- p.69 / ILLUSTRATIONS --- p.71 / references --- p.94

Cathelicidin, a pleiotropic host defense peptide, has been shown to promote cutaneous wound repair and reaches high levels in the gastric mucosa during acute Helicobacter pylori-associated inflammation. The expression of cathelicidin, nevertheless, has also been found to be down-regulated in gastric hyperplastic polyps, tubular adenomas, and adenocarcinomas. We therefore hypothesized that cathelicidin might contribute to gastric ulcer healing and suppress gastric cancer growth. In this study, the role of this peptide in gastric tissue repair and carcinogenesis was investigated. / Collectively, this study demonstrates for the first time that cathelicidin can promote tissue repair and suppress cancer growth in stomachs by eliciting differential cellular signaling and responses in normal and cancerous gastric epithelial cells. These unique biological activities may open up a novel therapeutic avenue for the treatment of these diseases. / Concerning gastric carcinogenesis, the human cathelicidin LL-37 lowered gastric cancer cell proliferation and delayed G1-S transition in vitro and inhibited the growth of gastric cancer xenograft in vivo. Knockdown or induction of endogenous LL-37 by RNA interference or 1alpha,25-dihydroxylvitamin D3, respectively, increased or suppressed cell proliferation. In this connection, LL-37 increased bone morphogenetic protein (BMP) signaling, manifested as increases in BMP4 expression and the subsequent Smad1/5 phosphorylation and the induction of Smad6 and Smad7. Moreover, LL-37 increased the expression of p21Waf1/Cip1, whose induction was abolished by the knockdown of BMP receptor II. Knockdown of BMP receptor II or p21Waf1/Cip1 also abrogated the anti-mitogenic action of LL-37. The activation of BMP signaling by LL-37 was accompanied with the inhibition of chymotrypsin-like and caspase-like activity of proteasome. In this regard, proteasome inhibitor MG-132 mimicked the effect of LL-37 by increasing BMP4 mRNA expression and Smad1/5 phosphorylation. In addition, cyclin E 2 was down-regulated by LL-37 via a BMP-independent mechanism. Further analysis of clinical samples revealed that LL-37 and p21Waf1/Cip1 mRNA expression were both down-regulated in gastric cancer tissues and their expression were positively correlated. These findings indicate that LL-37 inhibits gastric cancer cell proliferation through activation of BMP signaling via a proteasome-dependent mechanism. / In relation to gastric ulcer healing, results revealed that ulcer induction in rats increased the expression of rat cathelicidin rCRAMP in the gastric mucosa. Further increase in expression of rCRAMP by local injection of rCRAMP-encoding plasmid promoted ulcer healing by enhancing cell proliferation and angiogenesis. rCRAMP directly stimulated proliferation of cultured rat gastric epithelial cells (RGM-1), which was abolished by inhibitors of matrix metalloproteinase (MMP), epidermal growth factor receptors (EGFR) tyrosine kinase, or mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase. rCRAMP also increased EGFR and ERK1/2 phosphorylation via an MMP-dependent mechanism. Knockdown of transforming growth factor alpha (TGFalpha), which is a ligand of EGFR, by small interfering RNA completely nullified the mitogenic signals evoked by rCRAMP in RGM-1 cells. These findings suggest that rCRAMP exhibits pro-healing activity in stomachs through TGFalpha-dependent transactivation of EGFR and its related signaling pathway to induce proliferation of gastric epithelial cells. / Wu, Ka Kei. / Adviser: Joseph J. Y. Sung. / Source: Dissertation Abstracts International, Volume: 71-01, Section: B, page: 0252. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 153-178). / 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 Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.