Expression profile of mucins (MUC2, MUC5AC and MUC6) in Helicobacter pylori infected pre-neoplastic and neoplastic human gastric epithelium

RUT and ELISA were down for H. pylori confirmation. Human gastric biopsy sections were stained using immunohistochemistry with MUC2, MUC5AC and MUC6 antibodies.MUC5AC was expressed in the superficial epithelium and the upper part of the gastric pits. MUC6 expression was detected in the lower part of the gastric glands. MUC2 was expressed in intestinal metaplasia, mostly in goblet cells. The mucin expression profile in the progressive stages of H. pylori infected human gastric epithelium allows the identification of intestinal metaplasia, which is characterized by a decreased expression of the gastric mucins (MUC5AC and MUC6) and de novo expression of MUC2.In conclusion, our results suggest that there is altered expression of MUC5AC and MUC6 together with the aberrant expression of MUC2 in intestinal metaplasia, during the process of gastric carcinogenesis. The present study indicates that the MUC2 mucin expression pattern is a reliable marker of intestinal metaplasia, which appears in the context of H. pylori infected individuals.Helicobacter pylori colonizes human gastric mucosa and causes gastritis and intestinal metaplasia (IM), which may evolve towards gastric carcinoma [1-3]. H. pylori infection was established as a type I human carcinogen in IARC [4]; it was recently shown that the bacteria are also capable of inducing gastritis, IM, and gastric carcinoma in Mongolian gerbils [5-8]. In humans, H. pylori also colonizes the duodenal mucosa whenever there is gastric metaplasia [9]. H. pylori infection in human is therefore dependent on the gastric microenvironment, which is determined to a large extent by the mucin and carbohydrate composition of the gastric mucin layer.Mucins are heavily glycosylated glycoproteins that are the major components of the mucous viscous gel covering the surface epithelial tissues [10]. To date, nine distinct epithelial mucin genes (MUC1, 2, 3, 4, 5AC, 5B, 6, 7, and 8) have been identified [11-21]. In situ hybridization and immunohist