Abstract
Expression of vascular endothelial growth factor (VEGF) in 133colorectal tumor specimens comprised of 27adenomas, 46early colorectal carcinomas, 60advanced colorectal carcinomas was evaluated by RT-PCR, Northern blot hybridization, and was immunohistochemistry. Tumor angiogenesis paralleled tumor development, and partially associated with VEGF expression, in colorectal adenomas and the early stages of human colorectal cancer. Expression of VEGF mRNA in advanced colorectal carcinomas was correlated with tumor progression, including metastasis. We attempted to clarify the role of VEGF in the tumor growth, neovascularization, and metastasis of human colon cancer by using cells transfected with the VEGF gene. We found that sense-VEGF transfectants have a growth advantage due to vigorous tumor angiogenesis. We also demonstrated that sense-VEGF transfectants metastasized to the liver and had greater potential to induce peritoneal dissemination. In conclusion, the present study provided clear evidence that VEGF plays an important role in cancer growth by stimulating neovascularization and subsequent metastasis.
