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Connexin43 (CX43), a protein that forms gap junction channels and hemichannels in astrocytes, is downregulated in high-grade gliomas. Its relevance for glioma therapy has been thoroughly explored; however, its positive effects on proliferation are counterbalanced by its effects on migration and invasion. Here, we show that a cell-penetrating peptide based on CX43 (TAT-Cx43) inhibited c-Src and focal adhesion kinase (FAK) and upregulated phosphatase and tensin homolog in glioma stem cells (GSCs) derived from patients. Consequently, TAT-Cx43 reduced GSC motility, as analyzed by time-lapse microscopy, and strongly reduced their invasive ability. Interestingly, we investigated the effects of TAT-Cx43 on freshly removed surgical specimens as undissociated glioblastoma blocks, which revealed a dramatic reduction in the growth, migration, and survival of these cells. In conclusion, a region of CX43 (amino acids 266–283) exerts an important anti-tumor effect in patient-derived glioblastoma models that includes impairment of GSC migration and invasion.

[Background]: Since 1957, the Simpson grading system has been considered a predictive system for meningioma recurrence. However, since then, surgical equipment and neurosurgical technique have developed extensively, so this grading system should be re-evaluated. This study aims to assess if the recurrence rate and recurrence-free survival (RFS) are different after Simpson grade I, II, and III resections in World Health Organization (WHO) grade I meningiomas. [Methods]: We retrospectively reviewed the data of patients who underwent surgical treatment of WHO grade I meningiomas located in the convexity (group 1), falx/parasagittal (group 2), skull base, and tentorium (group 3) between June 1991 and December 2011. We compared the recurrence rates and RFSs between Simpson grade I, II, and III resections in both overall cases and tumor subsets according to their localization. [Results]: A total of 224 meningiomas were included in this study. There were no significant differences in recurrence rates and RFSs between Simpson grades I, II, and III. In each of the location groups, no significant differences were noted between the different degrees of Simpson. [Conclusions]: We have shown that complete resection of WHO grade I meningiomas achieves excellent tumor control, regardless of Simpson grades. More aggressive attempts at tumor resection (ie, Simpson grade I) must be balanced against the risks of removing dura or damaging critical neurovascular structures.

Tumor-infiltrating immune cells are part of a complex microenvironment that promotes and/or regulates tumor development and growth. Depending on the type of cells and their functional interactions, immune cells may play a key role in suppressing the tumor or in providing support for tumor growth, with relevant effects on patient behavior. In recent years, important advances have been achieved in the characterization of immune cell infiltrates in central nervous system (CNS) tumors, but their role in tumorigenesis and patient behavior still remain poorly understood. Overall, these studies have shown significant but variable levels of infiltration of CNS tumors by macrophage/microglial cells (TAM) and to a less extent also lymphocytes (particularly T-cells and NK cells, and less frequently also B-cells). Of note, TAM infiltrate gliomas at moderate numbers where they frequently show an immune suppressive phenotype and functional behavior; in contrast, infiltration by TAM may be very pronounced in meningiomas, particularly in cases that carry isolated monosomy 22, where the immune infiltrates also contain greater numbers of cytotoxic T and NK-cells associated with an enhanced anti-tumoral immune response. In line with this, the presence of regulatory T cells, is usually limited to a small fraction of all meningiomas, while frequently found in gliomas. Despite these differences between gliomas and meningiomas, both tumors show heterogeneous levels of infiltration by immune cells with variable functionality. In this review we summarize current knowledge about tumor-infiltrating immune cells in the two most common types of CNS tumors-gliomas and meningiomas-, as well as the role that such immune cells may play in the tumor microenvironment in controlling and/or promoting tumor development, growth and control.