Glioma-initiating cells at tumor edge gain signals from tumor core cells to promote their malignancy
Intratumor spatial heterogeneity facilitates therapeutic resistance in glioblastoma (GBM). Nonetheless, understanding of GBM is limited to the resectable tumor core lesion while the seeds for recurrence reside in the unresectable tumor edge. In this study, stratification of GBM to core and edge demonstrated clinically relevant surgical sequelae. We establish regionally derived models of GBM edge and core that retain their spatial identity in a cell autonomous manner. Edge cells show a higher capacity for infiltrative growth, while core cells demonstrate greater therapy resistance. Investigation of intercellular signaling between these two cell populations uncovered the paracrine crosstalk from tumor core that provokes malignancy and therapy resistance of edge cells. These phenotypic alterations were initiated by HDAC1 in GBM core cells which subsequently affect edge cells by secreting the soluble form of CD109 protein.  Our data reveal the role of intracellular communication between regionally different populations of GBM cells in tumor recurrence. Overall design: Comparison of edge and core regions within human glioblastoma tumors