miRNA-182 and the regulation of the glioblastoma phenotype - toward miRNA-based precision therapeutics.

Glioblastoma (GBM) is an incurable cancer, with survival rates of just 14-16 months after diagnosis. (1) Functional genomics have identified numerous genetic events involved in GBM development. One of these, the deregulation of microRNAs (miRNAs), has been attracting increasing attention due to the multiple biologic processes that individual miRNAs influence. Our group has been studying the role of miR-182 in GBM progression, therapy resistance, and its potential as GBM therapeutic. Oncogenomic analyses revealed that miR-182 is the only miRNA, out of 470 miRNAs profiled by The Cancer Genome Atlas (TCGA) program, which is associated with favorable patient prognosis, neuro-developmental context, temozolomide (TMZ) susceptibility, and most significantly expressed in the least aggressive oligoneural subclass of GBM. miR-182 sensitized glioma cells to TMZ-induced apoptosis, promoted glioma initiating cell (GIC) differentiation, and reduced tumor cell proliferation via knockdown of Bcl2L12, c-Met and HIF2A. (2) To deliver miR-182 to intracranial gliomas, we have characterized Spherical Nucleic Acids covalently functionalized with miR-182 sequences (182-SNAs). Upon systemic administration, 182-SNAs crossed the blood-brain/blood-tumor barrier (BBB/BTB), reduced tumor burden, and increased animal subject survival. (2-4) Thus, miR-182-based SNAs represent a tool for systemic delivery of miRNAs and a novel approach for the precision treatment of malignant brain cancers.