Spasmolytic polypeptide-expressing metaplasia associated with higher expressions of miR-21, 155, and 223 can be regressed by Helicobacter pylori eradication in the gastric cancer familial relatives

Background and aims: Spasmolytic polypeptide-expressing metaplasia (SPEM) is a preneoplastic gastric cancer lesion related to epigenetic microRNA (miRNA) expression. This study elucidated whether Helicobacter pylori-infected first-degree relatives of patients with gastric cancer (GCF) are susceptible to have SPEM and correlated with miR-21, 155, and 223 expressions. We also validated whether SPEM and these miRNAs can be regressed after H pylori eradication. Methods: We prospectively enrolled 148 GCF and 148 nonulcer dyspepsia (NUD) subjects without gastric cancer familial history as controls. Each case had received a panendoscopy to determine H pylori status and gastric histology, including SPEM. The cases with SPEM were followed after H pylori eradication to determine SPEM regression. The total RNA was extracted to analyze tissues miR-21, 155, and 223 before and after eradication. Results: GCF subjects had a higher prevalence of H pylori infection (73% vs 32%) and SPEM (42% vs 14%, P < 0.01) than controls. The tissue miR-21, 155, and 223 in antrum were higher in cases with SPEM than in those without SPEM (P <= 0.05). There was similar SPEM reversibility after H pylori eradication between GCF subjects and controls (72% vs 69%, P = 0.852). In the SPEM regressed cases, tissue miR-21, 155, and 223 decreased after H pylori eradication (P < 0.05). Conclusion: The H pylori-infected GCF subjects were prone to have SPEM with higher tissues miR-21, 155, and 223 expressions. H pylori eradication can result in a 70% SPEM regression, accompanied by a decline in miR-21, 155, and 233 expression levels.