Engineered exosomes for targeted delivery of miR-187-3p suppress the viability of hemangioma stem cells by targeting Notch signaling.

BACKGROUND

Infantile hemangioma (IH) is the most common benign vascular tumor of infancy and is proposed to arise from hemangioma stem cells (HemSCs). Therapies for IH include oral beta-blockers, surgery, and the delivery of novel therapeutic agents, such as bioactive microRNAs (miRNAs). However, in the extracellular environment, miRNA is easily hydrolyzed by RNase. miR-187-3p has previously been confirmed to promote or inhibit various malignancies, but its role in the development and progression of IH remains unclear.

METHODS

In this study, engineered exosomes (E-exos) were exploited to deliver miR-187-3p into HemSCs. The E-exos were generated by introducing miR-187-3p mimics into human adipose mesenchymal stem cell-derived exosomes (hAMSC-exos) via electroporation. The expression and secretion of miR-187-3p were examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Western blot analysis, transmission electron microscopy (TEM), and dynamic light scattering (DLS) were used to characterize the exosomes. The effects of the E-exos on HemSC viability were examined using the tube formation assay and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay. Western blot analysis was used to evaluate the effects of E-exos on Notch-1, Notch-4, and Jagged-1 expression in HemSCs.

RESULTS

E-exos did not differ significantly from hAMSC-exos in terms of morphology, particle size, or surface markers. E-exos could be internalized by HemSCs, and the course of cellular uptake of E-exos was time dependent. After 12 hours of treatment, E-exos significant inhibited tube formation. Notch signaling was also inhibited by miR-187-3p loading by E-exos. E-exos showed excellent inhibitory effects against HemSC proliferation via Notch signaling.

CONCLUSIONS

This study provides a foundation for using hAMSC-exos to optimize current clinical options to facilitate IH treatment and deliver therapeutic agents in the future.