The Regulation of Microglial Cell Polarization in the Tumor Microenvironment: A New Potential Strategy for Auxiliary Treatment of Glioma-A Review

Glioma is the most common primary tumor of the central nervous system and normally should be treated by synthetic therapy, mainly with surgical operation assisted by radiotherapy and chemotherapy; however, the therapeutic effect has not been satisfactory, and the 5-year survival rates of anaplastic glioma and glioblastoma are 29.7% and 5.5%, respectively. To identify a more efficient strategy to treat glioma, in recent years, the influence of the inflammatory microenvironment on the progression of glioma has been studied. Various immunophenotypes exist in microglial cells, each of which has a different functional property. In this review, references about the phenotypic conversion of microglial cell polarity in the microenvironment were briefly summarized, and the differences in polarized state and function, their influences on glioma progression under different physiological and pathological conditions, and the interactive effects between the two were mainly discussed. Certain signaling molecules and regulatory pathways involved in the microglial cell polarization process were investigated, and the feasibility of targeted regulation of microglial cell conversion to an antitumor phenotype was analyzed to provide new clues for the efficient auxiliary treatment of neural glioma.