Résumé
Objective: To investigate the differentiated expressions of EphB2 protein in colorectal carcinoma at different clinicopathologic staging and in different colorectal carcinoma cell lines with varying metastasis potential and explore the effect of EphB2 on colorectal cancer and its action mechanism. Methods: Immunohistochemistry was used to detect the expression of EphB2 and microvascular density (MVD) in colorectal carcinoma tissues (n = 43) and normal colon tissues (n = 10) was detected. Four colorectal carcinoma cell lines with varying metastasis potential, SW480, HT29, HCT116, and LoVo cells, were cultured in vitro. The expression of EphB2 protein was measured by Western blotting and the transcription of EphB2 mRNA was determined by RT-PCR. Results: EphB2 was expressed in the cytoplasm of the most colon carcinomas. EphB2 receptor expression was negatively related with tumor infiltration depth and distant metastasis; EphB2 receptor expression was positively related with the differentiation degree of colon cancer. Expression of EphB2 protein had positive correlation with MVD in tumor tissues; the expression level of EphB2 was decreased in high-metastatic HCT116 and LoVo cells compared with low-metastatic SW480 and HT29 cells. Conclusion: Decreased expression of EphB2 may promote the carcinogenesis and progression of colorectal carcinoma. One of the explanations for the effect of EphB2 is its regulaion on tumor angiogenesis.