Resurrecting p53 by an Artificial Nano-Protein for Potent Photodynamic Retinoblastoma Therapy

The treatment of retinoblastoma (RB), a formidable eye cancer that affects infants and children, is not only aimed at saving lives but at preserving ocular function, maintaining optimal visual acuity, and enhancing the overall quality of life. Photodynamic therapy has already been established as a secure and dependable therapeutic modality for the treatment of ocular diseases that effectively preserves ocular function; however, it fails to provide satisfactory outcomes against RB. To address this formidable challenge, groundbreaking advancement is aspired by delving into the genetic characteristics of RB, which initially involves the wild-type p53 pathway but is subsequently suppressed by MDM2 and MDMX. In this study, an artificial nanoprotein (ANP) is developed through the fusion of human serum albumin with a potent MDM2/MDMX degrading peptide and the porphyrin-photosensitizer verteporfin (VP). ANP effectively dismantles MDM2/MDMX proteins within the ubiquitin-proteasome degradation pathway and triggers VP-PDT-mediated cell death through mitochondrial impairment. Remarkably, ANP exhibited remarkable therapeutic efficacy in both subcutaneous and in situ RB mouse models, while maintaining a highly favorable biosafety profile. Collectively, ANP not only provides compelling evidence for sensitizing photodynamic RB therapy by reactivating p53, but also serves as an exceptionally potent photosensitizer with promising potential for clinical translation in RB treatment.