Restoring the oncosuppressor activity of microRNA-34a in glioblastoma using a polyglycerol-based polyplex

Glioblastoma multiforme (GBM) is the most common and aggressive primary neoplasm of the brain. Poor prognosis is mainly attributed to tumor heterogeneity, invasiveness, and drug resistance. microRNA-based therapeutics represent a promising approach due to their ability to inhibit multiple targets. In this work, we aim to restore the oncosuppressor activity of microRNA-34a (miR-34a) in GBM. We developed a cationic carrier system, dendritic polyglycerolamine (dPG-NH(2)), which remarkably improves miRNA stability, intracellular trafficking, and activity. dPG-NH(2) carrying mature miR-34a targets C-MET, CDK6, Notch1 and BCL-2, consequently inhibiting cell cycle progression, proliferation and migration of GBM cells. Following complexation with dPG-NH(2), miRNA is stable in plasma and able to cross the blood–brain barrier. We further show inhibition of tumor growth following treatment with dPG-NH(2)–miR-34a in a human glioblastoma mouse model. We hereby present a promising technology using dPG-NH(2)–miR-34a polyplex for brain-tumor treatment, with enhanced efficacy and no apparent signs of toxicity.