CCL5 of glioma-associated microglia/macrophages regulates glioma migration and invasion via calcium-dependent matrix metalloproteinase 2

Abstract

Background Glioma-associated microglia/macrophages (GAMs) comprise macrophages of peripheral origin and brain-intrinsic microglia, which support tumor progression. Chemokine C-C ligand 5 (CCL5) is an inflammatory mediator produced by immune cells and is involved in tumor growth and migration in several cancers, including glioma. However, the mechanisms detailing how CCL5 facilitates glioma invasion remain largely unresolved. Methods Glioma migration and invasion were determined by wound healing, transwell assay, and 3D µ-slide chemotaxis assay. The expression levels of CCL5, CD68, matrix metalloproteinase 2 (MMP2), phosphorylated Ca2+/calmodulin-dependent protein kinase II (p-CaMKII), p-Akt, and phosphorylated proline-rich tyrosine kinase 2 were determined by cytokine array, quantitative PCR, western blot, or immunohistochemistry. Zymography and intracellular calcium assays were used to analyze MMP2 activity and intracellular calcium levels, respectively. Results CCL5 modulated the migratory and invasive activities of human glioma cells in association with MMP2 expression. In response to CCL5, glioma cells underwent a synchronized increase in intracellular calcium levels and p-CaMKII and p-Akt expression levels. CCL5-directed glioma invasion and increases in MMP2 were suppressed after inhibition of p-CaMKII. Glioma cells tended to migrate toward GAM-conditioned media activated by granulocyte-macrophage colony-stimulating factor (GM-CSF) in which CCL5 was abundant. This homing effect was associated with MMP2 upregulation, and could be ameliorated either by controlling intracellular and extracellular calcium levels or by CCL5 antagonism. Clinical results also revealed the associations between CCL5 and GAM activation. Conclusion Our results suggest that modulation of glioma CaMKII may restrict the effect of CCL5 on glioma invasion and could be a potential therapeutic target for alleviating glioma growth.

Targeting the Calcium Signalling Machinery in Cancer

“…Importantly, CCL18 expression correlated with invasive behaviour and poor survival in patients with breast cancer. Similarly, release of the inflammatory chemokine C-C motif chemokine 5 (CCL-5) from TAMs induced migration of glioma cells in a process dependent on increases in cytosolic [Ca 2+ ] and phosphorylation of CaMKII [ 263 ]. Indeed, CCL-5 has previously been implicated in invasive behaviour and metastasis in a range of tumours, including prostate, bone, and breast cancers [ 264 ].…”

LncRNA LINC00998 inhibits the malignant glioma phenotype via the CBX3-mediated c-Met/Akt/mTOR axis

“…Glioma is the most common and malignant form of primary central nervous tumor in adults, accounting for more than 50% of all primary brain tumors 1 . The average survival of patients with glioblastoma is 12–15 months due to the high invasion and proliferation rates 2 . The current clinical treatment of glioma includes surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy.…”

The Role of Cytokines and Chemokines in Shaping the Immune Microenvironment of Glioblastoma: Implications for Immunotherapy

“…Patient tumours showed elevated CCL5 expression compared to the normal brain [ 85 ], suggesting the expression is upregulated in the course of malignant transformation. CCL5 can act as a prognostic measure of glioblastoma patient survival, as CCL5 overexpression is associated with shorter overall survival [ 86 ]. Within the glioblastoma TME, CCL5 produced by GAMs, mesenchymal stem cells (MSCs) and tumour cells signals through CCR1, CCR5 and CD44 [ 86 , 87 , 88 , 89 ].…”

“…CCL5 can act as a prognostic measure of glioblastoma patient survival, as CCL5 overexpression is associated with shorter overall survival [ 86 ]. Within the glioblastoma TME, CCL5 produced by GAMs, mesenchymal stem cells (MSCs) and tumour cells signals through CCR1, CCR5 and CD44 [ 86 , 87 , 88 , 89 ]. Similar to its ligand, CCR5 expression in glioblastoma has also been associated with poor survival [ 90 ], and this expression can be upregulated on tumour cells under hypoxic conditions as an adaptive mechanism for the adverse environment [ 91 ].…”

“…The link between the CCL5/CCR5 pathway and tumour growth is also evident in vivo, as knockdown of CCR5 in tumour cells can significantly reduce tumour size and expression of the proliferation marker Ki67 [ 90 ]. The CCL5/CCR5 pathway also supports tumour cell invasion by activating downstream pathways such as PI3K/AKT and calcium/calmodulin-dependent protein kinase II (CaMKII) that ultimately result in the production of matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) [ 86 , 90 , 91 ]. These enzymes degrade extracellular matrix (ECM) barriers, enabling an active migratory process with the penetration of tumour cells deeper into surrounding brain tissue [ 94 ].…”