Expression and significance of Nrf2 and Keap1 protein in esophageal squamous cell carcinoma

Objective Lots of researches had shown that nuclear factor erythroid-2 p45-related factor 2 (Nrf2) and Kelch-like ECH-associated protein 1 (Keap1) were correlated with the formation and development of tumors. This study was designed to detect the expression of Nrf2 and Keap1 protein in esophageal squamous cell carcinoma and explore its relationship with clinicopathological parameters, and to explore their role in the formation and development of esophageal cancer. Methods From July 2010 to November 2016, the cancer and adjacent tissues of 174 cases of esophageal cancer in the First Affiliated Hospital of Xinjiang Medical University were collected to detect the expression level of Nrf2 and Keap1 protein by using immunohistochemistry. The data was analyzed statistically by using SPSS 17.0 statistical software. Results ① The expression level of Nrf2 in the cancer tissues of esophageal squamous cell carcinoma was significantly higher than that in adjacent normal tissues (χ²=21.259, P<0.001), but the expression level of Keap1 in the cancer tissues was significantly lower than that in adjacent normal tissues (χ²=34.863, P<0.001). ② There was a statistically significant difference in the expression of Nrf2 and Keap1 among the different ethnic groups in Xinjiang (Nrf2: χ²=12.674, P=0.020, Keap1: χ²=11.237, P=0.004). ③ The positive expression of Nrf2 was associated with tumor lymph node metastasis (χ²=5.040, P=0.036) and esophageal cancer tissue grading (χ²=10.187, P=0.020). The positive expression of Keap1 was associated with tumor lymph node metastasis (χ²=6.916, P=0.010) and esophageal cancer tissue grading (χ²=15.432, P<0.001). ④ There was a correlation between the expression of Nrf2 and Keap1 in esophageal squamous cell carcinoma (r=0.219, P=0.031). Conclusion In the formation, development and metastasis of esophageal squamous cell carcinoma, multiple factors may be involved, including Nrf2 and Keap1 proteins. This result will provide some new ideas for the further study of the prevention and clinical treatment of esophageal cancer and prognosis.