The Network of Cytokines in Brain Metastases

Abstract

Brain metastases are the most common of all intracranial tumors and a major cause of death in patients with cancer. Cytokines, including chemokines, interferons, interleukins, lymphokines, and tumor necrosis factors are key regulators in the formation of brain metastases. They regulate the infiltration of different cellular subsets into the tumor microenvironment and affect the therapeutic outcomes in patients. Elucidating the cancer cell-cytokine interactions in the setting of brain metastases is crucial for the development of more accurate diagnostics and efficacious therapies. In this review, we focus on cytokines that are found in the tumor microenvironment of brain metastases and elaborate on their trends of expression, regulation, and roles in cellular recruitment and tumorigenesis. We also explore how cytokines can alter the anti-tumor response in the context of brain metastases and discuss ways through which cytokine networks can be manipulated for diagnosis and treatment.

Keywords: brain metastasis; brain tumor; chemokines; cytokines; interferons; interleukins; lymphokines; tumor necrosis factors.

Figure 1

Cytokine and chemokine levels in brain metastases. Identifying the different levels of cytokines and chemokines in brain metastases from different primary tumors allows for the differentiation between patients with and without brain metastases. Red-colored cytokines correspond to studies that are based on patient samples.