Regional differences on production of chemokines in gastric mucosa between Helicobacter pylori-positive duodenal ulcer and gastric ulcer

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.

Functional promotor polymorphism in RANTES gene does not influence the clinical course of Helicobacter pylori infection

BACKGROUND AND AIMS

Helicobacter pylori was found to increase the transcription of RANTES as a potent chemoattractant cytokine in mucosal inflammation. The aim of this study was to test if a functional promotor polymorphism in the RANTES gene leading to a higher transcriptional activity influences the severity of the mucosal damage in H. pylori infected individuals.

METHODS

A single nucleotide polymorphism, C-471T, was genotyped by TaqMan technology in a sample of 344 consecutive patients with H. pylori infection undergoing upper gastrointestinal endoscopy and 370 blood donors. Association with the development of erosions and stomach or duodenum ulcers as well as atrophic gastritis were tested.

RESULTS

None of the genotypes were associated with the severity of mucosal damage in stomach or duodenum (P > 0.05).

CONCLUSION

Even though H. pylori itself induces expression of RANTES, at the transcriptional level, genetic variations leading to higher transcriptional activity do not modify the degree of inflammation.

mRNA expression of cytokines and chemokines in the normal gastric surface mucous epithelial cell line GSM06 during bacterial infection with Helicobacter felis

BACKGROUND AND AIM

A group of the proinflammatory and chemotactic cytokines (chemokines) has been considered as an important factor in the pathomechanism of different bacterial diseases, among them the common Helicobacter pylori infection. Experimental results obtained with gastric biopsy samples of H. pylori positive patients, and with H. pylori infected tumor originated gastric cell lines indicated that these cytokines have essential roles in the development and maintenance of the immune response and inflammation of the gastric mucosa during H. pylori infection. Although the mRNA expression was shown in these biopsy samples and cell lines, it is not yet proved that the normal gastric mucosal epithelial cells themselves express these cytokines. The establishment of a gastric surface mucous cell line with non-tumor origin (GSM06), and the usage of Helicobacter felis as a model of the classic H. pylori infection gave us the possibility to check this question.

MATERIALS AND METHODS

in this study GSM06 cells were infected with different numbers (10(5), 10(6), 10(7), 10(8), 10(9) bacterium/ml medium) of H. felis for two different time periods (2, 4 h). Cells treated with medium only were used as control. Then the mRNA expression of the following cytokines was measured by RT-PCR method in the GSM06 cells: proinflammatory cytokine IL1-beta, and chemokine RANTES, eotaxin, MCP-1, MIP1-alpha and MIP1-beta.

RESULTS

we found that neither mRNA of the investigated cytokines was expressed constitutively, however the GSM06 cells expressed the mRNA of each cytokine during H. felis infection.

CONCLUSION

our results prove that normal gastric surface mucous epithelial cells express immunologically active peptides during H. felis infection. We may suppose that the epithelial cells of the gastric mucosa contribute to the immune response and inflammation by expressing proinflammatory (IL1-beta) and chemotactic (RANTES, eotaxin, MCP-1, MIP1-alpha and beta) cytokines during H. pylori infection in human.