Eph/Ephrin signalling plays an important role in tumorigenesis, neovascularization, and vasculogenesis. However, studies concerning the role of EphB4 in colorectal cancer (CRC) show inconsistent results, and the function of EphB4 in the formation of CRC-related blood vessels is not fully understood. The aim of this study is to investigate the EphB4 expression in CRC and the role of EphB4 in tumour angiogenesis.EphB4 and EphrinB2 expressions were detected in 200 CRC samples and 50 paired colorectal mucosae by immunohistochemistry. Xenograft animal models were established by stable knockdown and stable overexpression of EphB4, and control cell lines were used to investigate the role of EphB4 in CRC. Microvessels were stained with anti-CD34, and microvessel density (MVD) was assessed.EphB4 protein was more highly expressed in CRC tissues compared with adjacent normal mucosae (P0.05), while EphrinB2 levels were unchanged. Modulation of EphB4 levels in colon cancer cell line SW480 resulted in significant effects on tumour growth and invasion in vivo, with stable overexpression of EphB4 associated with faster growth and invasion. Furthermore, microvessel density values in xenograft tumours were significantly correlated with EphB4 (P0.05).EphB4 acts as a tumour promoter associated with proliferation, invasion, and angiogenesis, and may be used as a potential CRC therapeutic target.
