Abstract

Abstract Paediatric high-grade gliomas (pHGG) are nearly uniformly fatal cancers that arise predominantly in children and adolescents and encompass Diffuse Midline Glioma (DMG) and Diffuse Hemispheric Glioma (DHG). Most patients harbour mutations in histone variants H3.1 or H3.3, resulting in global epigenetic dysregulation and a stalled oligodendroglial progenitor (OPC) or GABAergic interneuron progenitor (IP) fate for DMG and DHG, respectively. DLX2, a homeobox transcription factor, represses OPC fate and promotes IP cell fate and migration during early neurogenesis. Our lab has shown that Dlx2 binds to and regulates the promoters of Gad1/Gad2, as well as early (Olig2, Nkx2.2) and late (Myt1, Plp1) genes required for OPC differentiation in vivo. Co-expression of Dlx2 with these target sequences reduces reporter gene expression in vitro and Dlx1/2 double knockout mice exhibit increased expression of these OPC markers in vivo. Transient overexpression of a Dlx2-GFP construct in murine DMG cells led to significant IP marker increase (Gad1/2), decrease of OPC markers (Olig2, Nkx2.2) and global restoration of H3K27me3. Additionally, decreased proliferation, colony growth, invasion and migration were observed in vitro. To translate these findings in human pHGG, analysis of a bulk RNA-seq database of 62 patient-derived pHGG cell lines revealed an inverse relationship between DLX2 and OLIG2. DLX2 was knocked out of DLX2high/OLIG2low DHG cell lines using CRISPR-Cas9, and overexpressed in DLX2low/OLIG2high DMG cell lines using a DLX2-mCherry overexpression construct. Evaluation of cell fate markers and epigenetic marks will be presented. Changes in migration, invasion, and proliferation in vitro will also be presented, in addition to changes in tumour growth using a neonatal xenograft murine model in vivo. Manipulation of DLX2 in pHGG provides a model for investigating the link between the factors that control cell fate decisions in the developing brain and the aberrant differentiation state in pHGG.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.