DNMT1 Gene Expression in Patients with Helicobacter pylori Infection.

DNMT1, as a critical enzyme affecting epigenetics through methylation of DNA cytosine-rich sequences, regulates gene expression. Exterior factors including long-term infections, in this study Helicobacter pylori infection, could change host cells' epigenetics by affecting DNMT1 gene expression. This study investigated the statistical correlation between H. pylori virulence genes and DNMT1 gene expression in gastric antral epithelial cells of gastric adenocarcinoma and gastritis patients. In a case-control study, 50 and 53 gastritis and gastric adenocarcinoma antral biopsies, including 23 and 21 patients with H. pylori infection, respectively, were collected from hospitals in the west of Iran. Having extracted total RNA from gastric biopsy samples, cDNA was synthesized and virulence genes of H. pylori were detected by using the PCR method. Relative real-time RT PCR was used to detect ΔΔCt fold changes of the DNMT1 gene expression in divided groups of patients based on H. pylori infection and clinical manifestations. The results showed that along with increasing patients' age, the DNMT1 gene expression will increase in gastric antral epithelial cells of gastric cancer patients (P ≤ 0.05). On the other hand, the biopsy samples with infection of H. pylori cagA, cagY, and cagE genotypes revealed a direct correlation along with increased DNMT1 gene expression. This study revealed the correlations of H. pylori cag pathogenicity island genes with increased DNMT1 gene expression.

ptk2 and mt2a Genes Expression in Gastritis and Gastric Cancer Patients with Helicobacter pylori Infection.

Background: ptk2 and mt2a genes contribute to the cell cycle during proliferation and apoptosis, respectively. Designing a case-control study including gastric adenocarcinoma and gastritis patients with and without Helicobacter pylori infection would lead to determinate of the correlations between ptk2 and mt2a genes expression with H. pylori infection in gastric antral epithelial cells. Methods: Overall, 50 and 30 gastric antral biopsy samples of gastric cancer (case group) and gastritis (control group) patients were included into study, respectively. All biopsy samples were collected considering the exclusion criteria including patients with a history of consumption of tobacco, alcohol, and anti-H. pylori drugs. Each patient group is divided into with and without H. pylori infection to detect cDNA fold changes of ptk2 and mt2a genes by using Real Time RT PCR. Furthermore, the presence of H. pylori virulence genes was detected directly by using specific primers and simple PCR on cDNA synthesized from total RNA of gastric antral biopsy samples. Results: A negative correlation was revealed between age and clinical manifestations with the ΔCt value of the ptk2 gene (P < 0.05). The H. pylori iceA1/2 and cagE genes revealed positive and negative correlations with the ΔCt value of the ptk2 gene (P < 0.05), respectively. Furthermore, a weak correlation was detectable between H. pylori babA2/B, oipA, and cagY genes and the ΔCt value of the mt2a gene in gastric antral epithelial cells of patients (P < 0.1). Conclusions: The results of the current study opened a view for more investigation on the stunning roles of H. pylori infection in clinical outcomes through mt2a and ptk2 gene expression in gastric antral epithelial cells.

Relationship between Helicobacter pylori cagA Genotypes Infection and IL-10 and TGFß1 Genes' Expression in Gastric Epithelial Cells.

BACKGROUND: The correlation of Helicobacter pylori infection with gastritis, peptic ulcer, and gastric cancer has been proven. The aim of this study was to determine the effects of cagA + and cagA - genotypes of H. pylori on genes expression of interleukin (IL) -10 and tumor growth factor (TGF) ß1 in gastric epithelial cells of patients with gastritis and H. pylori infection. METHODS: In all, 45 gastric biopsy samples were collected from patients with gastritis and H. pylori infection admitted to Tohid Hospital in Sanandaj city. Status of urease and cagA genes of H. pylori were directly determined from the biopsy samples using polymerase chain reaction (PCR) method. Expression of IL-10 and TGF-ß1 genes in gastric epithelial cells of patients with gastritis and cagA + and cagA- genotypes of H. pylori infection was serveyed using real-time PCR method. RESULTS: Overall, 25 samples had infection with H. pylori cagA + and 20 with cagA - genotypes. This study showed that there is a positive correlation between cagA - genotypes of H. pylori and increasing of IL-10 gene expression in gastric epithelial cells of patients with gastritis (P = 0.001). CONCLUSIONS: Level of gene expression of IL-10 as an anti-inflammatory cytokine in gastric epithelial cells of patients with H. pylori infection is connected to cagA- genotypes.

Sirt1 Gene Expression and Gastric Epithelial Cells Tumor Stage in Patients with Helicobacter pylori Infection

Introduction: The World Health Organization has categorized Helicobacter pylori as a carcinogen for gastric cancer, which causes human mortality worldwide. A number of studies have shown that H. pylori affects cell signaling in gastric epithelial cells and changes the expression of some proteins such as proinflammatory cytokines. Bacterial infections may alter sirt1 and sirt2 genes expression in inflammatory tissues and cancer cells. In this study, sirt1 and sirt2 genes expression in gastric cancers was surveyed with reference to H. pylori status. Methods: Stomach biopsies were collected from 50 gastric cancer patients, 25 H. pylori-positive and 25 H. pylori-negative as determined by the urea rapid test. Tumor grade was determined by a pathologist. After total RNA extraction from gastric cancer biopsy samples and cDNA synthesis, sirt1 and sirt2 genes expression levels were determined by Real Time PCR and ΔΔCT methods. Results: There was no statistically significant link between H. pylori infection and sirt1 (P<0.899) and sirt2 (P<0.169) genes expression in gastric epithelial cells. However, pathologic findings showed that there is a statistically significant relationship between sirt1 gene expression and the tumor grade (P<0.024). Discussion: A statistically significant association was found between sirt1 gene expression and tumor grade of gastric cancers that could be due to effects on progression of cancer cells infected with H. pylori.