Expression of unfolded protein response gene glucose regulated protein 78 and X-box binding protein 1 in esophageal squamous cell carcinoma and their clinical significance

Abstract

Objective To investigate the expression of unfolded protein response (UPR) gene glucose regulated protein 78(GRP78) and X-box binding protein 1(XBP1) in esophageal squamous cell carcinoma, its effect on activation of the endoplasmic reticulum stress (ERS) and its mechanism in the growth of esophageal squamous cell carcinoma. Methods The expressions of GRP78 and XBP1 were detected by immunohistochemistry in 30 samples of esophageal squamous cell carcinoma and 30 samples of normal esophageal squamous epithelium. The correlation between expressions of both proteins and prognosis was analyzed. Results GRP78 positive rate was 83.3%(25/30) in esophageal carcinoma, while the proportion was 20.0%(6/30) in normal esophageal (χ2=25.833, P<0.05). XBP1 positive rate was 70.0% (21/30) in esophageal carcinoma, while the proportion was 26.7%(8/30) in normal esophageal(χ2=20.872, P<0.05). The positive rates of GRP78 and XBP1 in invasive muscular layer of esophageal squamous cell carcinoma were significantly higher than those in invasive mucous layer. Conclusion GRP78 and XBP1 are highly expressed in esophageal squamous cell carcinoma, which may involve the occurrence and development of the esophageal carcinoma. Key words: Esophageal neoplasms; Carcinoma, squamous cell; Unfolded protein response; Glucose regulated protein 78; X-box binding protein 1