Project description:The cell identities of CD49f+GSCs were further identified by comparing them with the E11.5 PGCs and P2 GSCs. The transcriptomic analysis revealed that the CD49f+GSCs had 1/3 similar genes profile to the E11.5 PGCs and P2 GSCs. Further gene ontology (GO) analysis demonstrated that the E11.5 PGCs, P2 GSCs, and CD49f+GSCs shared the partial similar gene expression profile of pluripotency regulation signaling pathway, PI3K-AKT signaling, chemokine signaling, and HIF-1 signaling.
Project description:Analysis of genes in GSCs and differentiated cells that are induced by MG132 treatment. Total RNAs were isolated from GSCs and differentiated cells after MG132 or DMSO treatment for 6 hrs in serum-free media
Project description:Both chromatin accessibility and histone modifications are known to influence transcriptional regulation. We investigated the differences of chromatin accessibility among GSCs, NSTCs and NPC using ATAC-seq (assay for transposase-accessible chromatin with high throughput sequencing).
Project description:Tumor heterogeneity of high-grade glioma (HGG) is recognized by four clinically relevant subtypes based on core gene signatures. However, molecular signaling in glioma stem cells (GSCs) in individual HGG subtypes is poorly characterized. Here we identified and characterized two mutually exclusive GSC subtypes with distinct dysregulated signaling pathways. Analysis of mRNA profiles distinguished proneural (PN) from mesenchymal (Mes) GSCs and revealed a pronounced correlation with the corresponding PN or Mes HGGs. Mes GSCs displayed more aggressive phenotypes in vitro and as intracranial xenografts in mice. Further, Mes GSCs were markedly resistant to radiation compared with PN GSCs. The glycolytic pathway, comprising aldehyde dehydrogenase (ALDH) family genes and in particular ALDH1A3, were enriched in Mes GSCs. Glycolytic activity and ALDH activity were significantly elevated in Mes GSCs but not in PN GSCs. Expression of ALDH1A3 was also increased in clinical HGG compared with low-grade glioma or normal brain tissue. Moreover, inhibition of ALDH1A3 attenuated the growth of Mes but not PN GSCs. Last, radiation treatment of PN GSCs up-regulated Mes-associated markers and downregulated PN-associated markers, whereas inhibition of ALDH1A3 attenuated an irradiation-induced gain of Mes identity in PN GSCs. Taken together, our data suggest that two subtypes of GSCs, harboring distinct metabolic signaling pathways, represent intertumoral glioma heterogeneity and highlight previously unidentified roles of ALDH1A3-associated signaling that promotes aberrant proliferation of Mes HGGs and GSCs. Inhibition of ALDH1A3- mediated pathways therefore might provide a promising therapeutic approach for a subset of HGGs with the Mes signature.
Project description: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. GSCs were treated with shNT (control), shMELK, shFOXM1, and EZH2 overexpression. Total RNA was isolated using the Qiagen RNeasy kit (Qiagen).
