Abstract
Background/Aims: Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults. The defining characteristics of GBM are diffuse infiltration of tumor cells into normal brain parenchyma, rapid growth, a high degree of infiltration of microglia and macrophages, and the presence of necrosis. Microglia/macrophages are frequently found in gliomas and they extensively infiltrate GBM tissue, up to 30% of total tumor mass. However, little is known about the effect of necrotic cells (NCs) on microglia infiltration in GBM and the tumor-infiltrating microglia-induced factors in GBMs. Methods: In this study, to address whether necrosis or necrosis-exposed GBM cells affect the degree of microglia/macrophage infiltration, migration and invasion/infiltration assays were performed. Culture supernatants and nuclear extracts of CRT-MG cells treated or untreated with necrotic cells were analyzed using a chemokine array and electrophoretic mobility shift assay, respectively. Results: The presence of NCs promoted the migration/infiltration of microglia, and GBM cell line CRT-MG cells exposed to NCs further enhanced the migration and infiltration of HMO6 microglial cells. Treatment with NCs induced mRNA and protein expression of chemokines such as Monocyte Chemoattractant Protein-1 (CCL2/MCP-1) and Macrophage Inflammatory Protein-3α (CCL20/MIP-3α) in CRT-MG cells. In particular, CCL2/MCP-1 and CCL20/MIP-3α were significantly increased in NC-treated CRT-MG cells. NCs induced DNA binding of the transcription factors Nuclear Factor (NF)-κB and Activator Protein 1 (AP-1) to the CCL2/MCP-1 and CCL20/MIP-3α promoters, leading to increased CCL2/MCP-1 and CCL20/MIP-3α mRNA and protein expression in CRT-MG cells. Conclusion: These results provide evidence that NCs induce the expression of CCL2/MCP-1 and CCL20/MIP-3α in glioblastoma cells through activation of NF-κB and AP-1 and facilitate the infiltration of microglia into tumor tissues.
Original language | English |
---|---|
Pages (from-to) | 1332-1346 |
Number of pages | 15 |
Journal | Cellular Physiology and Biochemistry |
Volume | 48 |
Issue number | 3 |
DOIs | |
State | Published - 1 Aug 2018 |
Bibliographical note
Publisher Copyright:© 2018 The Author(s). Published by S. Karger AG, Basel.
Keywords
- Glioblastoma
- Infltration
- Microglia
- Migration
- Necrosis