Biphasic Effects of bFGF Blockade on Lung Cancer Cell Invasion

Basic fibroblast growth factor (bFGF) is a potent mitogen implicated in tumor progression, yet its precise role in cancer cell invasion remains multifaceted. Here, we unveiled a dose-dependent, biphasic regulatory effect of bFGF blockade on the invasiveness of lung cancer cells. Using a neutralizing monoclonal antibody against bFGF (bFGF Ab), we demonstrated that moderate neutralization of bFGF inhibited tumor cell invasion. Conversely, excessive bFGF blockade paradoxically enhanced the invasive capacity of lung cancer cells. Furthermore, we showed that the divergent invasive phenotypes arising from varying degrees of bFGF inhibition were mediated by altered vascular endothelial growth factor (VEGF) secretion. These findings underscore the critical importance of dose optimization in bFGF-targeted therapies, particularly concerning their impact on lung cancer invasiveness, and identify VEGF as a key mediator of these effects.