Astrocyte plasticity shapes brain metastasis progression through tumor-astrocyte crosstalk

Brain metastases are ten times more common than primary brain tumors and pose a significant clinical challenge. How brain metastatic tumor cells adapt to the unique and hostile brain microenvironment remains unclear. Astrocytes, the most abundant glial cells in the brain, are emerging as key mediators regulating the development of brain metastases. Initially anti-metastatic, astrocytes are reprogrammed by tumor-derived signals, transitioning into a pro-metastatic phenotype. Here, we review the roles of astrocytes in brain metastasis and describe the evidence for their phenotypic plasticity, the basis of astrocyte-tumor interactions, and potential therapeutic strategies targeting these processes.