High EphA2 protein expression in renal cell carcinoma is associated with a poor disease outcome.

Jinsheng Xu,Shenglei Zhang,Huiran Zhang,Junxia Zhang,Yaling Bai,Liwen Cui

doi:10.3892/ol.2014.2196

Abstract

The receptor tyrosine kinase, ephrin type-A receptor 2 (EphA2), is normally expressed at sites of cell-to-cell contact in adult epithelial tissues, however, recent studies have shown that it is also overexpressed in various types of epithelial carcinomas, with the greatest level of EphA2 expression observed in metastatic lesions. In the present study, the association between the expression of EphA2 and the outcome of RCC patients was assessed. The high expression level of EphA2 was identified by log-rank test for a statistically significant prediction of the RCC outcome. In an overall multivariate analysis, the high expression level of EphA2 was identified as an independent predictor of RCC outcome. The length of survival of the patients with high EphA2 expression was shorter than that of the patients with a low level of expression (relative risk, 2.304; 95% CI, 1.102–4.818; P=0.027). The analysis of the expression levels of EphA2 in tumor tissues may aid in the identification of the patient subgroup that are at a high risk of a poor disease outcome.

Highlights

Renal cell carcinoma (RCC) accounts for 2‐3% of all cases of malignancy in adults worldwide
A high expression level of Eph type-A receptor 2 (EphA2) protein was significantly associated with the RCC TNM classification (P= 0.001), the size of tumor (P= 0.001) and the presence of lymph node metastasis (P=0.022), respectively
The level of EphA2 expression in resected RCC tumors was examined in the present study in order to determine its predictive power relative to the outcome of RCC

Summary

Introduction

Renal cell carcinoma (RCC) accounts for 2‐3% of all cases of malignancy in adults worldwide. As RCC is a disease that is associated with few early signs or symptoms, Key words: renal cell carcinoma, receptor tyrosine kinases, EphA2, outcome and is commonly diagnosed at an advanced stage [4], the development of novel approaches for outcome prediction is vital in patients with RCC. Receptor tyrosine kinases have significant roles in human tumor generation and progression [6]. While Eph type-A receptor 2 (EphA2) was initially isolated from a HeLa cell cDNA library [10], EphA1, its main ligand, was originally located in human umbilical vein endothelial cells in a tumor necrosis factor α model [11,12]. To the best of our knowledge, there have been no previous studies on the association between EphA2 and the outcome of RCC

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