OBJECTIVE To explore the expressions of mixed lineage kinase 1 (MLK1), enhancer of zeste homolog 2 (EZH2), sex-determining-region Y-box 2 (SOX2) and axin in cancer tissues of the gastric cancer patients with Helicobacter pylori infection and analyze the association with clinicopathologic features.

METHODS Totally 102 gastric cancer patients complicated with H.pylori infection who were treated in Shandong First Medical University Affiliated People′s Hospital from Jun. 2020 to Jun. 2023 were assigned as the infection group, meanwhile, 26 gastric cancer patients without H.pylori infection were chosen as the no infection group. The cancer tissues and para-carcinoma tissues were collected to detect the expressions of MLK1, EZH2, SOX2 and Axin proteins. The positive rates of expressions of the proteins in the cancer tissues and para-carcinoma tissues were compared between the two groups. The positive rates of expressions of the proteins in the cancer tissues were compared among the gastric cancer patients complicated with H.pylori infection who had different pathological parameters.

RESULTS The positive rates of expressions of MLK1 and EZH2 proteins of the infection group and the no infection group were higher in the cancer tissues than in the para-carcinoma tissues(P < 0.05), the positive rates of expressions of SOX2 and Axin were lower in the cancer tissues than in the para-carcinoma tissues(P < 0.05). The positive rates of expressions of MLK1 and EZH2 in cancer tissues and para-carcinoma tissues were higher in the infection group than in the no infection group(P < 0.05), the positive rates of expressions of SOX2 and Axin were lower in the infection group than in the no infection group(P < 0.05). The positive rates of expressions of MLK1 and EZH2 in cancer tissues of the gastric cancer patients complicated with H.pylori infection who had Ⅲ to Ⅳ stage, myenteric/submucosal layer, low differentiation and lymph node metastasis were higher than those of the patients who had Ⅰ to Ⅱ stage, myenteric/submucosal layer, intermediate to high differentiation and did not have lymph node metastasis(P < 0.05). The positive rates of expressions of SOX2 and Axin of the patients who had Ⅲ to Ⅳ stage, myenteric/submucosal layer, low differentiation and lymph node metastasis were lower than those of the patients who had Ⅰ to Ⅱ stage, myenteric/submucosal layer, intermediate to high differentiation and did not have lymph node metastasis(P < 0.05).

CONCLUSION The gastric cancer patients with H.pylori infection show high expressions of MLK1 and EZH2 proteins in cancer tissues and low expressions of SOX2 and Axin, which are associated with the TNM stage, depth of infiltration, degree of differentiation and lymphatic metastasis.