Effect of an aluminum hydroxide-magnesium hydroxide combination drug on adhesion, IL-8 inducibility, and expression of HSP60 by Helicobacter pylori

The role of CXC chemokines in the transition of chronic inflammation to esophageal and gastric cancer

Chronic inflammation may increase the risk to develop cancer, for instance esophagitis or gastritis may lead to development of esophageal or gastric cancer, respectively. The key molecules attracting leukocytes to local inflammatory sites are chemokines. We here provide a systematic review on the impact of CXC chemokines (binding the receptors CXCR1, CXCR2, CXCR3 and CXCR4) on the transition of chronic inflammation in the upper gastrointestinal tract to neoplasia. CXCR2 ligands, including GRO-α,β,γ/CXCL1,2,3, ENA-78/CXCL5 and IL-8/CXCL8 chemoattract pro-tumoral neutrophils. In addition, angiogenic CXCR2 ligands stimulate the formation of new blood vessels, facilitating tumor progression. The CXCR4 ligand SDF-1/CXCL12 also promotes tumor development by stimulating angiogenesis and by favoring metastasis of CXCR4-positive tumor cells to distant organs producing SDF-1/CXCL12. Furthermore, these angiogenic chemokines also directly enhance tumor cell survival and proliferation. In contrast, the CXCR3 ligands Mig/CXCL9, IP-10/CXCL10 and I-TAC/CXCL11 are angiostatic and attract anti-tumoral T lymphocytes and may therefore mediate tumor growth retardation and regression. Thus, chemokines exert diverging, sometimes dual roles in tumor biology as described for esophageal and gastric cancer. Therefore extensive research is needed to completely unravel the complex chemokine code in specific cancers. Possibly, chemokine-targeted cancer therapy will have to be adapted to the individual's chemokine profile.

Metal speciation, phytochemicals and Helicobacter pylori infection

Helicobacter pylori (HP) acquired in childhood is an important risk factor for gastric carcinoma. Once colonization is established, infection may be carried for life. The relationship between food intake and HP infection, the presence of metals and phytochemicals closely associated with oxidative stress within everyday diet are important topics to be considered. The possible anti-HP effects of phytochemicals, prooxidant effects exerted in the presence of metal species, intimate relations between some metals and HP, bivalent effects of some metal species in cancer, interactions between metal species and phytochemicals in HP infection are the topics, which require further research. Formulas or diets enriched with phytochemicals and metals against HP and, which are devoid of metals known to favour the growth of HP, may be suggested as the supplements to the classical treatment regimens. The importance of collective consideration of HP, metal species and phytochemicals should be emphasized.

Role of serum factors in epithelial cell responses to Helicobacter pylori infection in vitro

BACKGROUND

Gastric epithelial cell lines have been utilized extensively as tools to define aspects of the interactions between Helicobacter pylori and host epithelial cells. Fetal calf serum (FCS) is employed as a growth stimulant, but it is unclear whether this agent may in itself alter host responses.

METHODS

Two gastric epithelial cell lines were utilized to ascertain the effects of varying FCS concentration on cellular responses following H. pylori infection. Media containing 0%, 5% or 10% FCS was added to cell lines prior to infection with H. pylori of defined genotype. Cellular interleukin (IL)-8 production was measured as a marker of cellular response. Effects of altered FCS upon cell viability were also determined by trypan blue exclusion.

RESULTS

Interleukin-8 production by AGS cells following H. pylori infection was not altered by variation of media FCS concentration. However, KATO-III cells produced greater amounts of IL-8 when media was FCS-free than at 5% or 10% FCS. Although cellular viability was not altered in AGS cells exposed to varied concentrations of FCS, viability was decreased in serum-free KATO-III cells, but not when cells were kept at 5% FCS.

CONCLUSIONS

Serum-derived factors alter cellular responses to H. pylori infection in a cell-line-dependent manner and impaired cellular viability may relate to this effect. However, the mechanisms for these observations are unclear and further work is now required to determine the nature of these important interactions.