Expression of erythropoietin and erythropoietin receptor in non-small cell lung cancer and its correlation with microvessel density

Abstract

Erythropoietin and erythropoietin receptor (EPO-R) are expressed in many kinds of tumors. The EPO/EPO-R signaling is involved in tumor cell proliferation, invasion and angiogenesis. The aim of this study was to detect the expression of EPO-R in non-small cell lung cancer (NSCLC), and explore its correlation with angiogenesis. The expression patterns of EPO and EPO-R in 31 cases of NSCLC tissues were detected by immunohistochemistry, and that in benign lung lesions of 21 patients as control. To analyze the correlation of EPO/EPO-R expression patterns and clinicopathological factors. CD34 was used to label the vascular endothelial cells and calculate the microvessel density (MVD). The positive rates of EPO and EPO-R expression in NSCLC were 67.7% and 96.8%, respectively, significantly higher than those in the control ones. The positive rates of EPO and EPO-R expression in adjacent tissues were 19.4% and 35.5%, and in benign lesions were 9.5% and 19.0%, respectively (P < 0.001). The expression patterns of EPO/EPO-R were not related with pTNM stage, histological type, histological grade and lymph node metastasis (P > 0.05). Increased MVD was correlated with poor differentiation, lymph node metastasis, and advanced stage. High expression of EPO/EPO-R in NSCLC patients suggest that they may be involved in tumorigenesis. EPO/EPO-R expression and MVD are closely related, and they might be an endogenous stimulant of angiogenesis during the progression of non-small cell lung cancer. It may provide evidence for clinical diagnosis.