Exosomes as Specific Vehicles for Delivery of Combination Therapies for Inhibiting Autophagy and Inducing Apoptosis in MYCN-Amplified Neuroblastoma Displaying Gut Dysbiosis: Current Challenges and Future Opportunities

Neuroblastoma is a highly aggressive pediatric malignancy originating from neural crest progenitor cells, predominantly in the adrenal medulla. Amplification of the MYCN oncogene occurs in 20-30% of all neuroblastoma cases and approximately 50% of high-risk tumors, strongly correlating with poor prognosis, relapse, and multidrug resistance. MYCN-driven oncogenesis promotes tumor progression by suppressing apoptotic signaling and enhancing survival pathways, including autophagy-a key mechanism underlying resistance to chemotherapy and immunotherapy. This review examines current therapeutic strategies and resistance mechanisms in MYCN-amplified neuroblastoma, while introducing emerging approaches utilizing exosomes as precision drug delivery systems. Exosomes, nanoscale extracellular vesicles secreted by the tumor cells, exhibit natural tropism and can be engineered to selectively target neuroblastoma-specific biomarkers such as glypican-2 (GPC2), which is highly expressed in MYCN-amplified tumors. Leveraging this property, neuroblastoma-derived exosomes can be purified, modified, and loaded with small interfering RNA (siRNA) to silence MYCN expression, combined with chloroquine-an FDA-approved autophagy inhibitor-to simultaneously inhibit autophagy and induce apoptotic signaling. This dual-targeted approach aims to overcome drug resistance, reduce off-target toxicity, and enhance therapeutic efficacy through exosome-mediated specificity. Furthermore, gut dysbiosis has emerged as a critical factor influencing tumor progression and diminishing treatment efficacy in MYCN-amplified neuroblastoma. We propose integrating microbiota-derived exosomes engineered to deliver anti-inflammatory microRNAs (miRNAs) to the gut mucosa, restoring eubiosis and potentiating systemic anti-tumor responses. Collectively, exosome-based strategies represent a paradigm shift in formulating combination therapies, offering a multifaceted approach to target MYCN amplification, inhibit autophagy, induce apoptosis, and modulate the tumor-microbiome axis. These innovations hold significant promise for improving clinical outcomes in high-risk MYCN-amplified neuroblastoma patients.