Overexpression of EIF-5A2 is associated with metastasis of human colorectal carcinoma.

Our previous study has suggested an oncogenic role of eIF-5A2 in ovarian tumorigenesis. Abnormalities of eIF-5A2, however, in colorectal carcinoma are unclear. In this study, amplification and overexpression of eIF-5A2 in colorectal carcinoma were studied by fluorescence in situ hybridization and immunohistochemistry using colorectal carcinoma tissue microarrays, including 139 primary colorectal carcinomas and their adjacent normal mucosa, 22 paired premalignant adenomas, and 42 metastatic tumors. The immunohistochemistry results showed that overexpression of EIF-5A2 was detected in none of normal epithelial mucosa, 35.3% of colorectal adenomas, 53.2% of primary colorectal carcinomas, and 67.6% of metastases. Amplification of eIF-5A2 was detected in 15.8% (16/101) of informative colorectal carcinomas, and most of them showed overexpression of EIF-5A2. In primary colorectal carcinomas, the frequency of EIF-5A2 overexpression was significantly higher in colorectal carcinomas with lymphovascular invasion (61.2%) than that in colorectal carcinomas without lymphovascular invasion (36.6%, P < .05). In addition, significant positive associations were found between EIF-5A2 overexpression and the tumors' later pN and pM stages, as well as increased tumor cell proliferation (P < .05). These findings suggest that overexpression of EIF-5A2 in colorectal carcinomas may be important in the acquisition of a metastatic phenotype and plays an important role in colorectal carcinoma development and progression.