Peroxisome proliferator-activated receptor γ ligands inhibit VEGF-mediated vasculogenic mimicry of prostate cancer through the AKT signaling pathway

Vasculogenic mimicry (VM) describes functional vascular channels composed only of tumor cells and its presence predicts a poor prognosis for patients with prostate cancer. The present study demonstrated that prostate cancer PC-3 cells were able to form a patterned matrix or tubular VM in 3D cultures in vitro and rosiglitazone (RSG), the ligand of peroxisome proliferator-activated receptor gamma (PPAR gamma) and effectively inhibited the formation of VM structures in a dose-and PPAR gamma-dependent manner. In addition, RSG significantly inhibited prostate cancer cell migration and invasion. The inhibitory effect of RSG on VM formation could be at least partially explained by an RSG-driven downregulation of vascular endothelial growth factor (VEGF) levels and phosphorylation of AKT, which is known to be important in VM. Furthermore, the present study highlighted that VEGF and the phosphoinositide 3-kinase/AKT pathway exert a positive feedback regulation in the process of VM formation. These findings reveal new therapeutic potential for PPAR gamma ligands in anti-cancer therapy.