P-selectin Targeting Stimulates Caveolin-1-Mediated Endothelial Transcytosis in Medulloblastoma

Abstract Medulloblastoma (MB) is the most common malignant pediatric brain tumor with ~30% mediated by Sonic hedgehog (SHH) signaling. While SHH effector Smoothened inhibition is promising, therapeutic index is reduced by high systemic doses required for sufficient intracranial drug concentrations. Treatment-related toxicities associated with radiation therapy result in lifelong morbidity, and SHH pathway inhibition in children notably results in permanent bone defects. Here, we found that nanoparticle-mediated P-selectin targeting on tumor vasculature induces caveolin-1-dependent transcellular passage across the blood-brain barrier. A vismodegib nanocarrier that targets P-selectin exhibited striking efficacy and markedly reduced both bone-related toxicities and drug exposure to healthy brain. These findings demonstrate a potent strategy and novel mechanism for targeted intracranial pharmacodelivery that overcomes the restrictive endothelial barrier to achieve enhanced tumor-selective penetration and has therapeutic implications for other diseases within the central nervous system.