Welcoming Treat: Astrocyte-Derived Exosomes Induce PTEN Suppression to Foster Brain Metastasis  Maša Alečković, Yibin Kang  Cancer Cell  Volume 28, Issue 5, Pages 554-556 (November 2015) DOI: 10.1016/j.ccell.2015.10.010 Copyright © 2015 Elsevier Inc. Terms and Conditions

Figure 1 Exosome-Mediated Tumor-Stromal Crosstalk Primes the Outgrowth of Brain Metastases After dissemination to the brain, metastatic cancer cells may release factors to recruit astrocytes and induce astrogliosis. Astrocytes secrete miR-19a-containing exosomes into the brain microenvironment that can be taken up by cancer cells, leading to reduced PTEN levels and subsequent increased NFκB-dependent production of CCL2. Tumor-derived CCL2 recruits IBA1+ myeloid cells to stimulate proliferation and inhibit apoptosis of brain-metastatic cancer cells. It is possible that additional intercellular interactions and stromal components not depicted in this diagram are involved in the tumor-promoting function of reactive astrocytes. Cancer Cell 2015 28, 554-556DOI: (10.1016/j.ccell.2015.10.010) Copyright © 2015 Elsevier Inc. Terms and Conditions