Abstract 3204: Antitumor activity of a coencapsulated liposomal formulation of ceramides and doxorubicin in neuroblastoma models

Abstract Background: Neuroblastoma (NB) represents the most frequent and aggressive form of extracranial solid tumor of infants. Targeted therapies are severely limited by the lack of specific receptors, thus chemotherapy and radiotherapy remain the main treatment choices, which expose NB patients to systemic toxicity. Recently, we have demonstrated that cell surface Nucleolin (NCL) represents a novel cellular target for NB therapy. Methods: The cytotoxic potential of pH-sensitive nanocarriers (NC), decorated with the NCL-recognizing F3 peptide and incorporating a combination of the PI3K/Akt signaling inhibitors, C6-Ceramide (C6-Cer) or C18-ceramide (C18-Cer), and the topoisomerase II inhibitor doxorubicin (DXR) (F3-NC[C6-Cer/DXR] and F3-NC[C18-Cer/DXR], respectively), was tested in vitro on a panel of NB cell lines. Cytotoxicity was evaluated in monolayer and in multicellular tumor spheroid models, by MTS proliferation and Cell Titer Glo 3D cell viability assays, respectively. Apoptotic/necrotic cell death was investigated by Real Time-Glo Annexin VApoptosis and Necrosis assay. Results: F3-NC[C6-Cer/DXR] and F3-NC[C18-Cer/DXR] resulted significantly more effective, in term of reduction of NB cell viability, compared to the corresponding “drugs”-loaded untargeted NC formulations. Both formulations triggered apoptotic cell death, even if in a different kinetic profile. In particular, NB cells treated with F3-NC[C6-Cer/DXR] underwent apoptotic cell death earlier with respect to those treated with F3-NC[C18-Cer/DXR]. Interestingly, F3-NC[C6-Cer/DXR] exerted a significant superior cell killing effect when compared both to F3-NC[C18-Cer/DXR] and to F3-NC encapsulating only DXR, suggesting the importance of the combination treatment to enhance the antitumor effect against NB cells. Conclusion: Our preliminary findings demonstrate that the co-encapsulation and delivery of C6-Ceramide and DXR by NCL-recognizing nanoparticles exert potent antitumor effects against NB models in vitro. Ongoing in vivo experiments on clinically relevant mouse NB models (i.e. recapitulating primary tumor growth, metastases, and minimal residual disease) will allow us to define the possible use of F3-NC[C6-Cer/DXR] as an innovative therapeutic strategy for relapsed/refractory NB. Funding: AIRC IG n. 24397 to PF; CInTech (PRR) C644865576-00000005 to JNM.VB is recipient of AIRC ID 24397 contract. MBC is recipient of PD/BDE/150664/2020 (FCT) fellowship. Citation Format: Veronica Bensa, Mariana Biscaia-Caleiras, Mirco Ponzoni, Joao Nuno Moreira, Chiara Brignole, Fabio Pastorino. Antitumor activity of a coencapsulated liposomal formulation of ceramides and doxorubicin in neuroblastoma models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3204.