Single cell spatial analysis identifies regulators of brain tumor initiating cells

Glioblastomas (GBMs) are aggressive brain tumors with unmet medical need. In this study, we used spatial transcriptomics to understand the heterogeneity of distinct anatomical regions of the tumor microenvironment. We identified numerous extracellular matrix (ECM) molecules including biglycan elevated in areas infiltrated with brain tumor-initiating cells (BTICs). The ECM molecules including biglycan were differentially expressed by cells including injury response versus developmental BTICs. Biglycan promoted proliferation of BTICs, and this was associated with binding to LDL receptor-related protein 6. Biglycan-overexpressing BTICs grew to a larger tumor mass when implanted in mouse brains.