Altered Expression of Endogenous Soluble Vascular Endothelial Growth Factor Receptor-2 Is Involved in the Progression of Esophageal Squamous Cell Carcinoma

Abstract

Endogenous soluble vascular endothelial growth factor receptor-2 (esVEGFR-2), a new splicing variant of VEGFR-2, was shown to be the first endogenous specific inhibitor of lymphatic vessel growth. The expression of esVEGFR-2 and its clinicopathological roles in esophageal squamous cell carcinoma (ESCC) are unclear. In this article, quantitative RT-PCR was employed to detect the mRNA levels of esVEGFR-2 and VEGF-C in 90 paired primary ESCC tissues, along with immunohistochemical staining to measure esVEGFR-2 protein in 182 ESCC primary tissues. Correlations between esVEGFR-2 expression and clinicopathological features were also analyzed. Compared with the corresponding non-neoplastic esophageal mucosa tissues, the mRNA level of esVEGFR-2 was decreased, whereas the mRNA level of VEGF-C was increased in ESCCs. Downregulation of esVEGFR-2 mRNA level was significantly correlated with pTNM stages (χ2 = 7.790, p=0.02). Immunohistochemical staining of esVEGFR-2 was inclined to be reduced in ESCC tissues; lower esVEGFR-2 protein expression was related to better prognosis (χ2 = 6.366, p=0.012), whereas higher esVEGFR-2 protein accumulation in ESCC tissues was an independent prognostic factor for poor survival of patients (hazard ratio, 1.606; 95% confidence interval, 1.042–2.476; p=0.032). Taken together, altered expression of esVEGFR-2 is correlated with progression of ESCC. esVEGFR-2 might serve as a new independent prognostic marker for ESCC patients.