Brain metastatic versus non-metastatic breast cancer exosomes influence astrocyte response

摘要: Brain metastasis is a devastating, late-stage event affecting 10-30% of breast cancer patients, but it is unclear how breast cancer cells can cross the blood-brain barrier (BBB) and colonize the unique brain environment. Exosomes, endosomal-derived extracellular vesicles, have been reported to support premetastatic niche formation through recruitment of tumor growth-supporting cells, creating sites conducive to cancer development. Still, it is not known how exosomes might prime the distinctive brain environment for metastasis despite the ability of circulating exosomes to readily cross the BBB. Glial cells, namely astrocytes and microglia, are important contributors to brain metastasis, and astrocytes in particular secrete exosomes that promote tumor outgrowth in the brain. We therefore investigated the effects of breast cancer exosomes on astrocytes in promoting brain premetastatic niche formation. Using …