Analysis of Spermine Oxidase gene and proinflammatory cytokines expression in gastric cancer patients with and without Helicobacter pylori infection – A pilot study in Polish population

Purpose

Many types of cancer have infectious origins. Gastric cancer patients can demonstrate high seroprevalence of Helicobacter pylori (H. pylori). The aim of the present study was to assess the expression of SMOX gene in the group of Polish patients with gastric cancer. SMOX is believed to promote H. pylori-induced carcinogenesis via inflammation, DNA damage and activation of β-catenin signaling. We also assessed the mRNA expression of selected pro-inflammatory cytokines, i.e. IL-2, IFN-γ, TNF-α, and antimicrobial peptide, cathelicidin.

Materials/methods

The study material consisted of gastric tissue samples collected during total gastrectomy from three different places in stomach: from primary tumor, 3 ​cm away from the primary lesion, and from the wall opposite to the primary tumor. After RNA isolation, qPCR reactions were performed for the relevant genes.

Results

The obtained results confirmed an increased level of SMOX expression in gastric cancer patients with the history of H. pylori infection. And, as far as we know, this is the first study on SMOX gene expression conducted on tissue taken from a patient, not on a cell line. The levels of pro-inflammatory cytokines, i.e. IL-2, IFN-γ, TNF-α, were also increased, thus indicating their contribution to the specific inflammatory microenvironment of the tumor. Interestingly, the levels of CAMP, encoding antimicrobial peptide, were reduced in all tissue types.

Conclusions

The findings confirm that SMOX plays a role in gastric carcinogenesis. However, further research is needed on the role of inflammatory and other factors involved in this process to identify targets for cancer immunotherapy.