CCL21-CCR7 signaling promotes microglia/macrophage recruitment and chemotherapy resistance in glioblastoma

Glioblastoma (GBM) is the most common and fatal primary tumor of the central nervous system (CNS) and current treatments have limited success. Chemokine signaling regulates both malignant cells and stromal cells of the tumor microenvironment (TME), constituting a potential therapeutic target against brain cancers. Here, we investigated the C-C chemokine receptor type 7 (CCR7) and the chemokine (C-C-motif) ligand 21 (CCL21) for their expression and function in human GBM and then assessed their therapeutic potential in preclinical mouse GBM models. In GBM patients, CCR7 expression positively associated with a poor survival. CCL21-CCR7 signaling was shown to regulate tumor cell migration and proliferation while also controlling tumor associated microglia/macrophage recruitment and VEGF-A production, thereby controlling vascular dysmorphia. Inhibition of CCL21-CCR7 signaling led to an increased sensitivity to temozolomide-induced tumor cell death. Collectively, our data indicate that drug targeting of CCL21-CCR7 signaling in tumor and TME cells is a therapeutic option against GBM.

Automated summary

The expression of C-C chemokine receptor type 7 (CCR7) and chemokine (C-C motif) ligand 21 (CCL21) are associated with poor survival in GBM patients. CCL21-CCR7 signaling regulates tumor cell migration and proliferation, as well as the recruitment of tumor-associated microglia/macrophages and VEGF-A production, which contributes to vascular dysmorphia. Inhibition of CCL21-CCR7 signaling increases sensitivity to temozolomide-induced tumor cell death, suggesting it as a potential therapeutic option against GBM.