Year: 2018
Type: article
Abstract: All glioma tumors relapse after the surgical resection. Microglia is an important component of the tumor microenvironment and provides support for tumor growth. Both M1 pro-inflammatory and M2 pro-tumorigenic microglia were found in gliomas with predominance of M2. Surgical resection of brain tumors results in local tissue damage, causing microglial activation in the surgical area. We hypothesize that tumor resection provides signaling for microglial polarization modifications and exacerbates the malignant properties of the tumor cells that fail to be eliminated by resection, stimulating the tumor recurrence. The purpose of this study was to evaluate the dynamics of microglial polarization in the tumor resection area during the post-surgical period. C57BL/6/GL261 mouse glioma implantation model was used. M1 and M2 microglia were identified in area of tumor resection using western blot and immunofluorescent approaches (CD86, iNOS, CD206 and Arginase 1 were used as markers of M1 and M2 microglia). Study has been performed 0, 2 hours, 2, 6, and 10 days after the tumor resection. The dynamic shift in the immunological status of microglia have been found during the healing of the resected area. Up regulation of M2 microglia has been detected beginning 2 hours after tumor resection with further reduction by day 10. Same but less prominent dynamic of M1 microglia has been revealed. Electron microscopy demonstrated accumulation of phagocytic microglia in the immediate area of the resection edge with non-phagocytic microglia accumulated deeper in the tissue. These results suggest that the tumor resection procedure stimulates the polarization of both pro-tumorigenic M2 and inflammatory M1 microglia up to 10 days after tumor resection with the predominant accumulation of M1 microglia at the resection rim and accumulation of M2 deeper in the parenchyma. Acknowledgement: NIH Grants 1SC1GM122691 and R25GM110513.
Source: Neuro-Oncology
Institution: Central University of the Caribbean
Language: English
Subfield: Neurology
Field: Neuroscience
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2900185306