Presenting Author:

Jin Qi

Principal Investigator:

Amanda Saratsis

Department:

Neurological Surgery

Keywords:

DIPG, Tenascin-C , H3K27M

Location:

Third Floor, Feinberg Pavilion, Northwestern Memorial Hospital

B95 - Basic Science

TNC Expression in DIPG

Introduction: Diffuse intrinsic pontine glioma (DIPG) is a highly morbid pediatric brainstem tumor. Tenascin-C (TNC) is an extracellular matrix protein associated with NOTCH pathway activation, and is expressed during normal brain development by oligodendroglial cells (OPCs), the purported DIPG cell of origin. We previously reported TNC overexpression in DIPG tissue and CSF, associated with Histone H3K27M mutation. We therefore investigated the pattern and effect of TNC expression using pediatric glioma primary cell lines. Methods: TNC expression was evaluated in H3K27M mutant DIPG (n=7) and H3K27 wild type pediatric glioma cell lines (n=3). Cell lines were modified to evaluate effects of altered TNC expression on proliferation, migration and differentiation in vitro. To determine the molecular effects of altered TNC expression in DIPG in vitro, we decrease TNC expression via vector-mediated shRNA knockdown. Effects of genetic manipulations were confirmed by western blot and qPCR. Cell proliferation, migration and adhesion were compared, as well as patterns of gene expression (RNA-Seq) across cell lines. Luciferase-expressing DIPG cells modified with TNC shRNA were used to create mouse intracranial xenografts. Animal survival and tumor growth was compared between groups, and TNC expression confirmed by immunohistochemistry Results: TNC was detected in pediatric glioma primary cell lines (n=7), but did not correlate with K27M mutation or WHO grade. shRNA knockdown achieved up to 80% reduction in TNC expression, inhibiting cell proliferation and migration compared to control DIPG lines. Distinct pathways of gene expression favoring dedifferentiation and stem-like state correlated with higher TNC expression. Investigation of effects of genetically modified upregulation of TNC (cDNA) and in vivo studies are currently underway. Conclusions: Here, we report the pattern and effect of modulated TNC expression in pediatric brainstem glioma (DIPG) in vitro. Our findings suggest TNC may play a role in cell proliferation, migration, and maintaining stem-ness, possibly contributing to pediatric gliomagenesis. Further in vitro and in vivo studies exploring the mechanism of overexpression and effects of targeting TNC expression. Investigation of effects of genetically modified upregulation of TNC (cDNA) and in vivo studies are currently underway. Conclusions: Here, we report the pattern and effect of modulated TNC expression in pediatric brainstem glioma (DIPG) in vitro. Our findings suggest TNC may play a role in cell proliferation, migration, and maintaining stem-ness, possibly contributing to pediatric gliomagenesis. Further in vitro and in vivo studies exploring the mechanism of overexpression and effects of targeting TNC expression in DIPG are planned.