Overexpression of interleukin-8 receptor 2 (IL-8R2) indicates better prognosis in esophageal adenocarcinoma and squamous cell carcinoma procession.

Researches have showed that interleukin family or receptors play a role in many human tumor progressions including esophageal carcinoma. In this study, we examined the expression of interleukin-8 receptor 2 (IL-8R2) and analyze the relationship between it and esophageal carcinoma clinical characteristics. IL-8R2 protein expression was confirmed by immunohistochemistry and immunofluorescence arrays and was analyzed further via Western blot and qRT-PCR analysis in frozen tissues. The correlation between their expression levels and clinical characteristics were evaluated by Mann-Whitney and Kruskal-Wallis test. Via Kaplan-Meier plots and Cox proportional hazard models, overall survival (OS) was analyzed. Compared with normal esophageal tissue, IL-8R2 protein was overexpressed significantly in esophageal cancer (p < 0.05) and was observed both in cytoplasm and nuclear. The lower expression of IL-8R2 protein was observed with higher p staging of esophageal cancer, and the significant association between them was confirmed (p = 0.000), and in advanced p T stage, the similar result was obtained (p = 0.015); however, compared with lymph node metastasis-negative group, it is no significant difference in positive group (p = 0.152). In a Kaplan-Meier analysis, compared with IL-8R2 low expression, IL-8R2 high expression identified a group of patients with the longest OS. Cox proportional hazard models revealed that IL-8R2 predicted long time to OS. The higher expression of IL-8R2 was found in early esophageal carcinoma, which may indicate that IL-8R2 plays an important role and is better prognostic factor in esophageal cancer development.