Red blood cell-derived extracellular vesicles with miR-204 mimic loading for pediatric neuroblastoma treatment

Neuroblastoma (NB) is the most common extracranial solid tumor in pediatric population with a high degree of heterogeneity in clinical outcomes, ranging from spontaneous remission to rapid progression and death. Upregulation of a tumor suppressor miR-204 in patient-derived neuroblastoma tumors was associated with good prognosis independent of known risk factors. While miR-204 is recognized as a therapeutic candidate, its delivery was unavailable. This study aimed to develop red blood cell-derived extracellular vesicles (RBC-EVs) as the miR-204 carrier and evaluate the inhibitory activity against neuroblastoma cell lines and spheroids. MiR-204 mimics were loaded into RBC-EVs (RBC-EVmiR-204) by electroporation with the optimized parameters of 250 V, 20 ms, 10 pulsing times. RBC-EVmiR-204, but not the native RBC-EVs, could inhibit cell viability, migration and spheroid formation and growth of MYCN-amp and MYCN non-amplification (MYCN-NA) NB cells, even though the suppressive effects were more preferable in MYCN-amp NB. For the mechanistic insight, SWATH-proteomics suggested that RBC-EVmiR-204 induced dysregulation of ribosomal proteins and alterations in RNA metabolism, leading to inhibiting neuroblastoma progression. This study developed RBC-EVmiR-204 as an alternative/adjunct therapy of pediatric neuroblastoma. The therapeutic efficacy of RBC-EVmiR-204 should be further investigated in preclinical models and clinical studies.