Helicobacter pylori is the strongest known risk factor for gastric adenocarcinoma, and strains that possess the cag secretion system, which translocates the bacterial effector CagA into host cells, augment cancer risk. H. pylori strains that express the vacuolating cytotoxin or the outer membrane protein OipA are similarly associated with severe pathologic… (More)
Gastric cancer is a leading cause of cancer deaths, but analysis of its molecular and clinical characteristics has been complicated by histological and aetiological heterogeneity. Here we describe a comprehensive molecular evaluation of 295 primary gastric adenocarcinomas as part of The Cancer Genome Atlas (TCGA) project. We propose a molecular… (More)
This review provides a state of the art description of gastric cancer etiology, the infectious agent, host factors, the precancerous cascade, clinical aspects, and prevention strategies. The biology of Helicobacter pylori, the primary causative agent, is discussed as well as the environmental factors that may modulate its effects.
The development of gastritis during Helicobacter pylori infection is dependent on an activated adaptive immune response orchestrated by T helper (Th) cells. However, the relative contributions of the Th1 and Th17 subsets to gastritis and control of infection are still under investigation. To investigate the role of interleukin-21 (IL-21) in the gastric… (More)
Once acquired, Helicobacter pylori infection is lifelong due to an inadequate innate and adaptive immune response. Our previous studies indicate that interactions among the various pathways of arginine metabolism in the host are critical determinants of outcomes following infection. Cationic amino acid transporter 2 (CAT2) is essential for transport of… (More)
Inflammatory bowel disease (IBD), consisting of Crohn's disease and ulcerative colitis (UC), results in substantial morbidity and is difficult to treat. New strategies for adjunct therapies are needed. One candidate is the semi-essential amino acid, L-arginine (L-Arg), a complementary medicine purported to be an enhancer of immunity and vitality in the lay… (More)
Accurate and high-throughput technologies are needed for identification of new therapeutic targets and for optimizing therapy in inflammatory bowel disease. Our aim was to assess multi-analyte protein-based assays of cytokines/chemokines using Luminex technology. We have reported that Luminex-based profiling was useful in assessing response to L-arginine… (More)
The genome of the bacterium Helicobacter pylori has evolved over the millennia since its migration out of Africa along with its human host approximately 60,000 years ago. Human migrations, after thousands of years of permanent settlement in those lands, resulted in seven prototypes of genetic populations of H. pylori with distinct geographical… (More)
Transition metals are necessary for all forms of life including microorganisms, evidenced by the fact that 30% of all proteins are predicted to interact with a metal cofactor. Through a process termed nutritional immunity, the host actively sequesters essential nutrient metals away from invading pathogenic bacteria. Neutrophils participate in this process… (More)
The draft genome sequences of six Colombian Helicobacter pylori strains are presented. These strains were isolated from patients from regions of high and low gastric cancer risk in Colombia and were characterized by multilocus sequence typing. The data provide insights into differences between H. pylori strains of different phylogeographic origins.