Hypoxic Glioma Cell-Secreted Exosomal miR-301a Activates Wnt/?-catenin Signaling and Promotes Radiation Resistance by Targeting TCEAL7.

ABSTRACT: Recent evidence suggests that microRNAs (miRNAs) can be released to the extracellular microenvironment and mediate cell-cell communication through exosomes. The aim of this study was to identify exosomal miR-301a (exo-miR-301a) involved in glioblastoma (GBM) radioresistance and reveal the possible mechanisms. The exo-miR-301a specifically secreted by hypoxic GBM cells could transfer to corresponding normoxia-cultured cells and promote radiation resistance. Hypoxic exo-miR-301a directly targeted TCEAL7 genes, which were identified as a tumor suppressor in GBM malignancy and actively repressed its' expression in normoxic glioma cells. Our studies indicated that TCEAL7 negatively regulated the Wnt/?-catenin pathway by blocking ?-catenin translocation from cytoplasm to nucleus. Interestingly, we clarified that the Wnt/?-catenin signaling was activated by miR-301a and TCEAL7 mediated the important procession. The exo-miR-301a was involved in the resistance to radiotherapy, and the effects would be reversed by miR-301a inhibition or TCEAL7 overexpression to regulate the Wnt/?-catenin axis. Here we show that exo-miR-301a, which is characteristically expressed and secreted by hypoxic glioma cells, is a potent regulator of Wnt/?-catenin and then depresses radiation sensitivity through targeting anti-oncogene TCEAL7. The newly identified exo-miR-301a/TCEAL7-signaling axis could present a novel target for cellular resistance to cancer therapeutic radiation in GBM patients.

SUBMITTER: Yue X 

PROVIDER: S-EPMC6838947 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature