The role of MUC2 in cancer - Biological significance and therapeutic implications: A review.

Mucin 2 (MUC2) is a secretory glycoprotein that is mainly produced by goblet cells in the intestinal epithelium. MUC2 plays an important role in forming a layer of mucus that acts as a physical and biochemical barrier, providing protection to the epithelial lining, hence preventing from mechanical injury, microbial invaders, and toxins. A regulated MUC2 expression is vital in maintaining proper intestinal integrity and physiological functions. Dysregulated MUC2 expression has been implicated in the pathological conditions, including chronic inflammatory disorders and various malignancies. The altered MUC2 expression in numerous cancers has been associated with tumor growth and metastasis as well as poor prognosis. A decrease in MUC2 expression is typically reported in colorectal cancer and is correlated with depletion of goblet cells, which directly results in a compromised mucosal barrier. On the contrary, MUC2 overexpression has been observed in mucinous cancers of breast, lung and colorectal adenocarcinomas, characterized by excess mucus production. This review assessed the differential expression and functional significance of MUC2 across various cancer types, presenting it as a potential biomarker or target for therapeutic intervention in oncology.