Apical MUC1 expression revealed on the foveolar epithelium in H. pylori gastritis

Microbe-MUC1 Crosstalk in Cancer-Associated Infections

Infection-associated cancers account for ∼20% of all malignancies. Understanding the molecular mechanisms underlying infection-associated malignancies may help in developing diagnostic biomarkers and preventative vaccines against malignancy. During infection, invading microbes interact with host mucins lining the glandular epithelial cells and trigger inflammation. MUC1 is a transmembrane mucin glycoprotein that is present on the surface of almost all epithelial cells, and is known to interact with invading microbes. This interaction can trigger pro- or anti-inflammatory responses depending on the microbe and the cell type. In this review we summarize the mechanisms of microbe and MUC1 interactions, and highlight how MUC1 plays contrasting roles in different cells. We also share perspectives on future research that may support clinical advances in infection-associated cancers.

MUC1 and MUC5AC Acting on Helicobacter pylori-Related Deficiency and Solid Syndrome of Spleen and Stomach

To investigate the relationship of MUC1, MUC5AC, and the syndrome of spleen and stomach, 109 subjects (34 peptic ulcer (PU), 62 chronic gastritis (CG), and 13 healthy volunteers (CON)) were included. All the subjects included were surveyed with questionnaire to classify them into damp-heat syndrome of spleen and stomach (DHSS), spleen-qi deficiency syndrome (SQD), and CON, examined by gastric endoscope, and biopsied. Rapid urease and methylene blue staining (MBS) were performed on every subject to diagnose for Helicobacter pylori (Hp) infection, and both were defined as Hp-positive. Hematoxylin and eosin (HE) staining was performed on every specimen to explore the histomorphology, inflammatory degree, and inflammatory activity of different groups; then Elivision™ plus kit was used to test the expression of MUC1 and MUC5AC. All the results of digital images were reviewed by two experts blindly. The inflammatory degree with Hp infection was higher than those uninfected or CON, but no significant difference was found between DHSS and SQD. And the expressions of MUC5AC with positive Hp was higher than those with negative Hp or CON regardless of the deficiency and solid syndrome of spleen-stomach but not for MUC1. We speculate that the deficiency and solid syndrome of spleen-stomach is a condition like Tai Ji symbol of dynamic equilibrium, showing the higher expression of MUC5AC but no change of MUC1 in the circumstance of Hp infection.

Epithelial MUC1 promotes cell migration, reduces apoptosis and affects levels of mucosal modulators during acetylsalicylic acid (aspirin)-induced gastropathy

MUC1, a transmembrane mucin highly expressed in the stomach, is up-regulated after acetylsalicylic acid (ASA) intake in humans and mice. Epithelial Muc1/MUC1 facilitates mucosal wound healing by enhancing cell migration and proliferation, protecting against apoptosis and mediating expression of mucosal modulators.

Gastric mucin expression in first-degree relatives of gastric cancer patients

OBJECTIVES

There are currently no accepted clinical guidelines for the surveillance of first-degree relatives (FDRs) of gastric cancer patients. The existence of intestinal metaplasia, as well as altered mucin expression, might be associated with an increased risk for gastric cancer. In the present study we aimed to investigate the mucin phenotype of individuals with a family history of gastric cancer.

METHODS

We included FDRs of gastric cancer patients. Individuals with functional chest pain served as controls. Upper endoscopy including extensive biopsy according to the Olga protocol was performed. Immunohistochemical staining for MUC1, MUC2, MUC5AC, and MUC6 was performed. Sera were assayed for pepsinogen I and II. Helicobacter status was determined through Giemsa staining and serological tests.

RESULTS

Forty FDRs and eight controls were included; the mean age was 46.7 ± 12.0 years. In both the study group and the control group there were no gross endoscopic findings and no histological evidence of intestinal metaplasia. Superficial MUC1 expression was significantly increased in the study group (47.5 vs. 0%; P=0.01). There was no difference in the expression of deep MUC1, MUC2, MUC5AC, or MUC6 between the groups, nor was there a difference in pepsinogen I/II levels or Helicobacter pylori exposure (35.0 vs. 25.0%; P=0.46).

CONCLUSION

Despite normal appearing mucosa and the absence of intestinal metaplasia according to histological analysis, FDRs of gastric cancer patients show increased expression of MUC1, which may serve as a predictor of future intestinal metaplasia, dysplasia, and cancer. Further studies are needed to verify these findings and their implications.