RESUMO
OBJECTIVES: To compare the expression of the Wnt signaling-associated proteins (Wnt3, ß-catenin, MMP-7) in gastric cancer and precancerous lesions with positive and negative Helicobacter pylori (H.pylori, Hp) infection, and to further explore the mechanisms underlying the Wnt signaling pathway involving in the formation of gastric cancer and its relationship with Hp infection. METHODS: The complete paraffin samples with pathologically confirmed diagnosis, who came from the First Hospital of Changsha from January 2018 to April 2020, were collected. All samples were randomly divided into a gastric cancer group (n=57), a precancerous lesion group (n=84), and a chronic superficial gastritis group (n=25). Improved Giemsa staining was used to detect Hp infection, and according the results of Hp infection the above groups were divided into a Hp positive subgroup and a negative subgroup. The expressions of Wnt3, ß-catenin and MMP-7 were examined with immunohistochemistry. RESULTS: The Wnt3, ß-catenin, and MMP-7 were highly expressed in the gastric cancer group and the gastric precancerous lesion group. The Wnt3 and MMP-7 were highly expressed in cytoplasm, and ß-catenin showed a tendency of cell membrane transferring to cytoplasm and nucleus, which was characterized by "nuclear translocation". The positive rates of the Wnt3, ß-catenin, and MMP-7 expressions in the gastric cancer group were higher than those in the precancerous lesion group and the chronic superficial gastritis group (all P<0.05), which showed a gradually increasing trend with the deterioration of differentiation degree. In addition, the expressions of Wnt3, ß-catenin, and MMP-7 in the Hp positive subgroup in the gastric cancer group and the precancerous lesion group were higher than those in the Hp negative subgroup (all P<0.05). CONCLUSIONS: Aberrant activation of Wnt signaling pathway is involved in the occurrence and development of precancerous lesions and gastric cancer, and which is related with Hp infection. Meanwhile, the Wnt3, ß-catenin and MMP-7 may be used as molecular markers for early diagnosis of gastric cancer and indicators to judge the degree of differentiation and malignancy of gastric cancer.
