Inhibition of hypoxic exosomal miR-423-3p decreases glioma progression by restricting autophagy in astrocytes

The tumor microenvironment (TME) of gliomas comprises glioma cells and surrounding cells, such as astrocytes, macrophages, T cells, and neurons. In the TME, glioma cells can activate normal human astrocytes (NHAs) through the secretion of exosomes and the activation of astrocytes can further improve the progression of glioma, leading to a poor prognosis for patients. However, the molecular mechanisms underlying NHAs activation by gliomas remain largely unknown. It this study, glioma-derived exosomes (GDEs) play an important role in the modulation of autophagy and activation of NHAs. Compared with normoxic glioma-derived exosomes, hypoxic glioma-derived exosomes (H-GDEs) further improved autophagy and activation of astrocytes, which strongly promoted the progression of glioma cells. In an miRNA array between two types of exosomes from gliomas, miR-423-3p was highly expressed in H-GDEs and played an important role in autophagy, resulting in the activation of NHAs. The mechanism by which hypoxic glioma cells react with NHAs to create an immunosuppressive microenvironment was identified and 15d-PGJ2 was established as an effective inhibitor of miR-423-3p to suppress NHA activation. These findings provide new insights into the diagnosis and treatment of gliomas by targeting autophagy and miR-423-3p expression.