M2 tumor-associated macrophage has been found to play a supportive role in the progression of glioma. The underlying mechanism, nevertheless, has been largely unknown. In our study, to investigate how M2 macrophage played role in glioma, firstly we've analyzed the clinicopathological significance of M2 macrophage existence on clinical tissues of glioma using detection of CD163 expression with immunohistochemistry. Then, we've artificially induced M2 macrophage from human monocyte cell line THP-1, followed by co-culture with glioma cell lines in vitro. It was found that M2 macrophage was shown to be markedly distributed in glioma relative to paired normal control; and high prevalence of M2 macrophage was significantly associated with poorer overall survival and tumor progression. Moreover, M2 macrophage was found to be able to promote the growth in vitro and tumorigenesis in vivo in xenografted mice model. Mechanistically, it is IL-10 from M2 macrophage that was shown to promote proliferation, dependent on activation of JAK2/STAT3 pathway. Further, IL-10 was found to be able to interact with JAK2 in glioma cells. Taking together, we for the first time found that IL-10 from M2 macrophage promoted proliferation of glioma through interaction with JAK2; thereby activating the JAK2/STAT3 pathway, indicative of IL-10 could be used as a therapeutic target in the curing of glioma.

The overexpression of matrix metalloproteinase (MMP) plays an important role in the context of tumor invasion and metastasis, and MMP-2 has been characterized as the most validated target for cancer. Therefore, it is necessary to design matrix metalloproteinase inhibitors (MMPIs) that would be active and selective against MMP-2 but non-selective toward other MMPs. Areas covered: This article clearly describes the structural character of MMP-2 followed by a review of the recent development of selective MMP-2 inhibitors based on their basic structures. Expert opinion: Over the past 30 years, MMPs have been considered to be attractive cancer targets, and several different types of synthetic inhibitors have been identified as anticancer agents, but only a small number of small MMPIs have been examined in clinical trials, and none of these molecules has been established as anticancer drugs due to their adverse effects. One major possibility is that the MMPIs used in clinical trials were broad-spectrum drugs that also inhibited the anti-tumor effects and influenced the mediation of the normal physiological processes of MMPs. MMP-2 has recently been characterized as the most validated target for cancer. Therefore, the design and synthesis of selective MMP-2 inhibitors would be helpful for the treatment of cancer.

During metabolic reprogramming, glioma cells and their initiating cells efficiently utilized carbohydrates, lipids and amino acids in the hypoxic lesions, which not only ensured sufficient energy for rapid growth and improved the migration to normal brain tissues, but also altered the role of immune cells in tumor microenvironment. Glioma cells secreted interferential metabolites or depriving nutrients to injure the tumor recognition, phagocytosis and lysis of glioma-associated microglia/macrophages (GAMs), cytotoxic T lymphocytes, natural killer cells and dendritic cells, promoted the expansion and infiltration of immunosuppressive regulatory T cells and myeloid-derived suppressor cells, and conferred immune silencing phenotypes on GAMs and dendritic cells. The overexpressed metabolic enzymes also increased the secretion of chemokines to attract neutrophils, regulatory T cells, GAMs, and dendritic cells, while weakening the recruitment of cytotoxic T lymphocytes and natural killer cells, which activated anti-inflammatory and tolerant mechanisms and hindered anti-tumor responses. Therefore, brain-targeted metabolic therapy may improve glioma immunity. This review will clarify the metabolic properties of glioma cells and their interactions with tumor microenvironment immunity, and discuss the application strategies of metabolic therapy in glioma immune silence and escape.

Due to extremely poor systemic bioavailability, the mechanism by which curcumin increases energy expenditure remains unelucidated. Accumulating evidence suggests a strong association between the gut microbiota (GM) and energy metabolism....