Validation of EZH2 targets in GSCs treated with shNT (control), shMELK, shFOXM1, and EZH2 overexpression. Homo sapiens

We demonstrate that the catalytic subunit of Polycomb Repressive Complex 2, EZH2, is targeted by the MELK-FOXM1 complex, which in turn promotes resistance to radiation in GSCs. Clinically, EZH2 and MELK are co-expressed in GBM and significantly induced in post-irradiation recurrent tumors whose expression inversely correlated with patient prognosis. Through gain-and loss-of-function study, our data show that MELK or FOXM1 contributes on GSC radioresistance by regulation of EZH2. We used microarrays to validate EZH2 target gene expression. Overall design: GSCs were treated with shNT (control), shMELK, shFOXM1, and EZH2 overexpression. Total RNA was isolated using the Qiagen RNeasy kit (Qiagen).