Transfer of microRNAs between glial tumor cells through tumor microtubes: focus and prospects in the treatment of gliomas.

High-grade gliomas are the most common primary tumors of the central nervous system in adults. Glioma cells communicate with each other through membrane extensions called tumor microtubes (TMs), which allow them to transfer biological material (organelles, intracellular vesicles). Their involvement in key processes of tumor progression has already been demonstrated, as has that of miRs. These small non-coding RNAs play a major role in post-transcriptional regulation of gene expression and thus participate in oncogenesis. While the transfer of miRs via tunneling nanotubes (membrane protrusions thinner than microtubes) has been demonstrated in cancers other than gliomas, their transfer via TMs needs to be clarified in gliomas. Studying the miRs exchanged through this intercellular communication pathway constitutes a new perspective for better understanding the biopathology of gliomas. Specific targeting of oncogenic miRs transferred by TMs could represent a promising new therapeutic strategy to limit tumor progression. Furthermore, these TMs could serve as privileged vectors for delivering therapeutic miRs to the heart of the tumor niche. This review summarizes the current knowledge regarding the prognostic impact of TMs in gliomas and their potential role in the transfer of miRs within the tumor niche. It also proposes perspectives for better characterization of these cellular communication devices and their potential clinical impact.