A) Circulating tumor cells extravasate in the brain. B) Astrocytes (in pink) release exosomes containing miRNAs that reduce PTEN expression in nearby tumor cells. C) Loss of PTEN results in release of the chemoattractant CCL2. D) CCL2 recruits IBA1+ myeloid cells (in green), which promote tumor cell proliferation and reduce apoptosis. E) The myeloid cells support tumor outgrowth in the brain.
Reprinted by permission from Macmillan Publishers Ltd: Nature, copyright 2015.
Zhang L, Zhang S, Yao J, Lowery FJ, Zhang Q, Huang WC, Li P, Li M, Wang X, Zhang C, Wang H, Ellis K, Cheerathodi M, McCarty JH, Palmieri D, Saunus J, Lakhani S, Huang S, Sahin AA, Aldape KD, Steeg PS, Yu D. (2015) Microenvironment-induced PTEN loss by exosomal microRNA primes brain metastasis outgrowth. Nature. 527: 100–4. PMID: 26479035; PMCID: PMC4819404