Helicobacter pylori and gastric cancer

Patients infected with Helicobacter pylon, a stomach colonizing bacteria, have an increased risk of developing gastric malignancies, in particular gastric carcinomas. This review was aimed to analyze the relationship between gastric carcinoma and Helicobacter pylon infection and to rule out the possibility of preventive measures. To identify articles for this review, a PubMed search was conducted using the following key words gastric cancer, Helicobacter pylon. The risk for developing cancer includes environmental, host-genetic and bacterial factors, which induce physiologic and histologic changes in the stomach. There are two major pathways for the development of gastric cancer by helicobacter pylon: the indirect action on gastric epithelial cells through inflammation leading to gastric atrophy and intestinal metaplasia and the direct action through the induction of protein modulation and gene mutation

Prevalence of Helicobacter pylori infection in advanced gastric carcinoma

BACKGROUD: There is substantial evidence that infection with Helicobacter pylori plays a role in the development of gastric cancer and that it is rarely found in gastric biopsy of atrophic gastritis and gastric cancer. On advanced gastric tumors, the bacteria can be lost from the stomach. AIMS: To analyze the hypothesis that the prevalence of H.pylori in operated advanced gastric carcinomas and adjacent non-tumor tissues is high, comparing intestinal and diffuse tumors according to Lauren's classification METHODS: A prospective controlled study enrolled 56 patients from "Hospital Universitário", Federal University of Rio Grande do Norte, Natal, RN, Brazil, with advanced gastric cancer, treated from February 2000 to March 2003. Immediately after partial gastrectomy, the resected stomach was opened and several mucosal biopsy samples were taken from the gastric tumor and from the adjacent mucosa within 4 cm distance from the tumor margin. Tissue sections were stained with hematoxylin and eosin. Lauren's classification for gastric cancer was used, to analyse the prevalence of H. pylori in intestinal or diffuse carcinomas assessed by the urease rapid test, IgG by ELISA and Giemsa staining. H. pylori infected patients were treated with omeprazole, clarithromycin and amoxicillin for 7 days. Follow-up endoscopy and serology were performed 6 months after treatment to determine successful eradication of H. pylori in non-tumor tissue. Thereafter, follow-up endoscopies were scheduled annually. Chi-square and MacNemar tests with 0.05 significance were used. RESULTS: Thirty-four tumors (60.7 percent) were intestinal-type and 22 (39.3 percent) diffuse type carcinomas. In adjacent non-tumor gastric mucosa, chronic gastritis were found in 53 cases (94.6 percent) and atrophic mucosa in 36 patients (64.3 percent). All the patients with atrophic mucosa were H. pylori positive. When examined by Giemsa and urease test, H. pylori positive rate in tumor...

RACIONAL: Existe evidência de que a infecção pelo Helicobacter pylori desempenha papel importante na causa do câncer gástrico e que é raramente encontrada em biopsias de gastrite atrófica e em tecido tumoral de câncer do estômago. Com a evolução para câncer gástrico avançado, a bactéria tende a desaparecer do tecido tumoral OBJETIVOS: Analisar a prevalência do H. pylori em peças operatórias de carcinomas gástricos avançados e no tecido adjacente aos tumores, comparando os tumores tipo intestinal e difuso de acordo com a classificação de Lauren MÉTODOS: Estudo prospectivo controlado incluiu 56 pacientes operados no Hospital Universitário da Universidade Federal do Rio Grande do Norte, Natal, RN, com câncer gástrico avançado, entre fevereiro de 2000 e março de 2003. Imediatamente após a gastrectomia, a peça operatória foi aberta e foram feitas várias biopsias do tecido neoplásico e da mucosa adjacente a 4 cm da margem tumoral. Os tecidos formam processados e corados pela hematoxilina-eosina. Foi usada a classificação de Lauren para carcinoma gástrico. A infecção pelo H. pylori foi diagnosticada pelo teste da urease, dosagem de IgG por ELISA e histopatologia com coloração Giemsa. Os pacientes infectados pelo H. pylori foram tratados com omeprazol, claritromicina e amoxicilina por 7 dias. Após 6 meses, 1 ano e 2 anos, foi feito seguimento utilizando endoscopia, dosagem de IgG e teste da urease para avaliar o sucesso da erradicação do H. pylori e recidiva do tumor RESULTADOS: O carcinoma tipo intestinal ocorreu em 34 (60,7 por cento) pacientes e 22 (39,3 por cento) foram acometidos de carcinoma difuso. No tecido adjacente não-tumoral a gastrite crônica foi observada em 53 casos (94,6 por cento) e mucosa atrófica em 36 pacientes (64,3 por cento), todos H. pylori positivos. Exames pelo Giemsa e teste da urease revelaram maior prevalência de H. pylori positivo no tecido tumoral do carcinoma tipo intestinal do que no tipo difuso. Quando foi comparada...

TNFa increases in vitro migration of human HPV18-positive SW756 cervical carcinoma cells

TNFa has been associated with both, tumor survival and apoptosis. This cytokine is also involved in promoting cell migration during wound healing and tumorigenesis. SW756 is a HPV18-positive cervical carcinoma cell line, which has been used to study different mechanisms of cervical cancer progression. An in vitro assay of scratch wound healing onto monolayers of SW756 cells was used to assess the effect of TNFa on cell migration into a wound space. It was found that SW756 cells have the ability to migrate, but not proliferate in response to scratch wounding in a serum-free medium supplemented with TNFa. RT-PCR analysis showed that SW756 cells express TNFa mRNA when incubated in medium with and without serum. Wound closure and migration rate of SW756 cells were significantly increased in the presence of serum-free media supplemented with TNFa (10 ng/mL) as compared to serum-free media, and media supplemented with either anti-TNFa antibody or both TNFa and anti-TNFa antibody (p<0.05). The results showed a stimulatory effect of TNFa on the migration of SW756 cervical carcinoma cells, suggesting a novel and important role for TNFa in cervical cancer progression.

A comparative study of PAP technique and in-situ molecular hybridization for identification of human papilloma viruses in cervical lesions.

The association of Human Papilloma Virus (HPV) with cervical lesions was correlated using peroxidase anti-peroxidase (PAP) technique and in-situ molecular hybridization (MH) with H3 labelled DNA probes (HPV type 6, 11, 16 and 18). The PAP technique to demonstrate capsid antigen and molecular hybridization for DNA sequences was studied in 30 cases. The correlation of HPV with cervical lesions was seen in 29.9% cases with PAP technique unlike 73.4% using M.H. technique, indicating the efficacy of the latter.