BACKGROUND: Angiogenesis is a prerequisite for tumor growth and metastasis in which CEACAM1 plays an essential role. PATIENTS AND METHODS: The role of CEACAM1 in vascularization and invasion of prostate and bladder cancer was studied. RESULTS: Our analyses demonstrate an epithelial downregulation of CEACAM1 in superficial bladder tumors and in PIN of the prostate. Concurrently, CEACAM1 is upregulated in endothelial cells of tumor blood vessels. CEACAM1 knockdown in tumor cell lines of the prostate and urinary bladder via siRNA results in an increase of tumor vascularization while CEACAM1 overexpression in these cells suppresses it. CONCLUSIONS: CEACAM1-induced signaling mechanisms play a role in induction of angiogenesis in superficial tumors of the prostate and bladder. Strategies to either conserve the epithelial CEACAM1 or to target endothelial CEACAM1 might be useful for an antiangiogenic therapy of bladder and prostate cancer.
