H-PYLORI INFECTION IS ASSOCIATED WITH DOWN-REGULATION OF E-CADHERIN, A MOLECULE INVOLVED IN EPITHELIAL-CELL ADHESION AND PROLIFERATION CONTROL

Extracellular matrix proteins and proteins involved in epithelial adhe sion are essential for maintenance of tissue structure. Helicobacter p ylori is the major aetiological agent in peptic ulcer disease and has been shown to increase gastric cancer risk up to ninefold. In this stu dy, changes induced by H pylori on the expression of extracellular mat rix proteins (collagen IV, fibronectin, and laminin) as well, as two e ssential proteins for cell-basement and cell-cell adhesion (alpha 6-in tegrin and E-cadherin) were assessed. Immunohistochemistry was perform ed in antral biopsy sections obtained from infected and non-infected p atients, and light microscopy was used to determine the distribution a nd intensity of specific staining. The results showed that the infecti on was significantly associated with downregulation of E-cadherin, an essential protein for maintenance of solid tissues and differentiation , but did not induce changes in the expression of alpha 6-integrin or the extracellular matrix proteins.