Progression of adult diffuse hemispheric astrocytoma is associated with a gene network driven by the myeloid transcription factor SPI1
Glioma associated Macrophages (GAMs) are the most abundant immune cell type within diffuse gliomas and their density correlates with poorer prognosis. GAMs consist of resident microglia and bone marrow derived (BDM) cells and increased BDM infiltration is thought to be associated with disease progression however no definitive human marker of BDM exists. This is particularly true of LGGs,  In this study we perform multicompartmental sampling and analyse GAMs from the perspective of gene regulatory networks. We show that GAMs and BDMs consist of distinct GRNs driven by the same master transcription factor SPI1, and that an increased activation of the blood derived SPI1 signature is associated with poorer prognosis in LGGs. Defining GAMs in terms of GRNs instead of marker genes alone permits a better understanding of the transcirptional programs that drive disease progression in diffuse gliomas.