Tumor angiogenesis: initiation and targeting - therapeutic targeting of an FGF-binding protein, an angiogenic switch molecule, and indicator of early stages of gastrointestinal adenocarcinomas -

Tumor angiogenesis has been related to the initiation as well as progression toward more aggressive behavior of human tumors. In particular, the activity of angiogenic factors is crucial for tumor progression. We previously characterized a secreted fibroblast growth factor-binding protein (FGF-BP) as a chaperone molecule, which binds to various FGFs, enhances FGF-mediated biochemical and biologic events and importantly is a crucial rate-limiting factor for tumor-dependent angiogenesis. We generated monoclonal antibodies that target FGF-BP protein and used them as a tool to evaluate frequency and pattern of FGF-BP expression during the malignant progression of pancreas and colorectal carcinoma in archival tissue samples. We found that FGF-BP is dramatically upregulated during the initiation of colorectal and pancreatic adenocarcinoma. Crucial genetic events underlying the initiation and progression of colorectal and pancreatic adenocarcinoma with a particular focus on the modulation of angiogenesis and antiangiogenic therapies are discussed. We propose that the upregulation of the secreted FGF-BP protein during early phases of pancreas and colon cancer could make this protein a possible serum marker indicating the presence of high-risk premalignant lesions. Furthermore, the biological activity of FGF-BP is neutralized by monoclonal antibodies suggesting the potential for antibody-based therapeutic targeting.