Astrocyte control of tumor progression and tumor-associated macrophages in glioblastoma

Glioblastoma multiforme (GBM) is one of the most aggressive solid tumors, and its grim prognosis has not changed much in the past 40 years. Astrocytes have complex roles in health and disease, and they are known to surround GBM tumors. However, little is known about the astrocyte role in tumor progression, their ability to shape the GBM microenvironment, or the molecular circuits that govern these activities. Here we report that depletion of activated astrocytes, in an immunocompetent murine model of GBM, results in tumor regression and improved mice survival. Suggesting, that reactive astrocytes play a pivotal role in regulating tumor progression. In addition, we also found that astrocytes support the immunosuppressive nature of the tumor microenvironment. Accordingly, astrocytes control the recruitment and activation of the tumor-associated microglia/macrophages (TAMs). Thus, targeting tumor-associated astrocytes or the astrocyte-TAMs cross-talk, are potential therapeutic approaches for GBM and other brain malignancies.