Glioblastoma (GBM) is one of the most aggressive cancers, comprising 60–70% of all gliomas. The large G-protein-coupled receptor family includes cannabinoid receptors CB1, CB2, GPR55, and non-specific ion receptor protein transporters TRPs. First, we found up-regulated CNR1, GPR55, and TRPV1 expression in glioma patient-derived tissue samples and cell lines compared with non-malignant brain samples. CNR1 and GPR55 did not correlate with glioma grade, whereas TRPV1 negatively correlated with grade and positively correlated with longer overall survival. This suggests a tumour-suppressor role of TRPV1. With respect to markers of GBM stem cells, preferred targets of therapy, TRPV1 and GPR55, but not CNR1, strongly correlated with different sets of stemness gene markers: NOTCH, OLIG2, CD9, TRIM28, and TUFM and CD15, SOX2, OCT4, and ID1, respectively. This is in line with the higher expression of TRPV1 and GPR55 genes in GSCs compared with differentiated GBM cells. Second, in a panel of patient-derived GSCs, we found that CBG and CBD exhibited the highest cytotoxicity at a molar ratio of 3:1. We suggest that this mixture should be tested in experimental animals and clinical studies, in which currently used Δ9-tetrahydrocannabinol (THC) is replaced with efficient and non-psychoactive CBG in adjuvant standard-of-care therapy.

Glioblastoma (GB), is the most common and aggressive malignant primary brain tumour in adults. Intra- and inter-tumour heterogeneity, infiltrative GB cell invasion and presence of therapy-resistant GB stem cells (GSCs) represent major obstacles to favourable prognosis and poor therapy response. Identifying the biomarkers of the most aggressive tumour cells and their more efficient targeting strategies are; therefore, crucial. Recently, transcription factor TRIM28 has been identified as a GB biomarker and, in this study, we have shown high expression of TRIM28 in GB and in low grade gliomas as well as higher expression in GSCs vs. differentiated GB cells, although in both cases not significant. We demonstrated significant in vitro inhibition of GB cells and GSCs invasiveness and spread in zebrafish brains in vivo by anti-TRIM28 selective nanobody NB237. TRIM28 was also enriched in GB (tumour) core and associated with the expression of stem cell genes, but was not prognostic for overall survival. However, based on the above results, we conclude that TRIM28 nanobody NB237 offers a new opportunity as a GB therapeutic tool.

Glioblastoma (GBM) is the most common and deadly primary brain tumor in adults. Understanding GBM pathobiology and discovering novel therapeutic targets are critical to finding efficient treatments. Upregulation of the lysosomal cysteine carboxypeptidase cathepsin X has been linked to immune dysfunction and neurodegenerative diseases, but its role in cancer and particularly in GBM progression in patients is unknown. In this study, cathepsin X expression and activity were found to be upregulated in human GBM tissues compared to low-grade gliomas and nontumor brain tissues. Cathepsin X was localized in GBM cells as well as in tumor-associated macrophages and microglia. Subsequently, potent irreversible (AMS36) and reversible (Z7) selective cathepsin X inhibitors were tested in vitro. Selective cathepsin X inhibitors decreased the viability of patient-derived GBM cells as well as macrophages and microglia that were cultured in conditioned media of GBM cells. We next examined the expression pattern of neuron-specific enzyme γ-enolase, which is the target of cathepsin X. We found that there was a correlation between high proteolytic activity of cathepsin X and C-terminal cleavage of γ-enolase and that cathepsin X and γ-enolase were colocalized in GBM tissues, preferentially in GBM-associated macrophages and microglia. Taken together, our results on patient-derived material suggest that cathepsin X is involved in GBM progression and is a potential target for therapeutic approaches against GBM.

Purpose: Glioblastoma (GBM) is the most common primary brain tumour and one of the deadliest cancers. In addition to late diagnosis and inadequate treatment, the extremely low survival rate is also due to the lack of appropriate therapeutic biomarkers and corresponding therapeutic agents. One of the potential therapeutic biomarkers is the intermediate filament vimentin, which is associated with epithelial-mesenchymal transition (EMT). The purpose of this study was to analyse the effect of the anti-vimentin nanobody Nb79 on cell invasion in vitro and in vivo. To further our understanding of the mechanism of action, we investigated the association between Nb79 and EMT in GBM and GBM stem cells by analysing the expression levels of key EMT-related proteins. Methods: The expression of vimentin in glioma tissues and cells was determined by RT-qPCR. An invasion assay was performed on differentiated glioblastoma cell line U-87 MG and stem cell line NCH421k in vitro as well as in vivo in zebrafish embryos. The effect of Nb79 on expression of EMT biomarkers beta-catenin, vimentin, ZEB-1 and ZO1 was determined by Western blot and immunocytochemistry. Results: Our study shows that vimentin is upregulated in glioblastoma tissue compared to lower grade glioma and non-tumour brain tissue. We demonstrated that treatment with Nb79 reduced glioblastoma cell invasion by up to 64% in vitro and up to 21% in vivo. In addition, we found that the tight junction protein ZO-1 had higher expression on the cell membrane, when treated with inhibitory anti-vimentin Nb79 compared to control. Conclusion: In conclusion, our results suggest that anti-vimentin nanobody Nb79 is a promising tool to target glioblastoma cell invasion.

Objective. The aim of this article is to present our experience with continuous dynamic mapping (CDM) of the corticospinal tract (CST) when removing tumors in motor eloquent regions. Methods. We studied 44 patients with a brain tumor adjacent to the CST where CDM was used. The mapping probe was integrated at the tip of the suction device. Thresholds for eliciting MEPs were recorded. In all patients, along with CDM, MEPs to direct cortical stimulation were also monitored throughout the operation. Motor function was assessed preoperatively, after the procedure and on discharge. Results. In the series, there were 37 patients with gliomas, six with brain metastasis, and one with cavernoma. The threshold to elicit MEPs in CDM was >20 mA in 17 cases, 16–20 mA in six cases, 11–15 mA in six cases, 6–10 mA in nine cases and 2–5 mA in six cases. MEPs to direct cortical stimulation were preserved in all patients. In three cases a new temporary motor deficit was noted. No new permanent motor deficit occurred. Gross total resection was reached in 57% of cases. Conclusions. From our experience, the combined use of CDM and MEPs to direct cortical stimulation improves the safety of surgery in the proximity of the CST, and at the same time offers the possibility of higher rates of gross total resection.

Occult spinal dysraphisms (OSDs) are caused by various defects in the embryogenesis of the spinal cord and represent an obstacle to the ascent of the conus, which allows the conus to pass from the lower levels of the spinal canal to the final position between L1 and L2 during normal foetal life. When an OSD tethers the spinal cord at the lower levels, it can lead to neurological symptoms, better known as tethered cord syndrome. Surgical treatment of OSD is primarily aimed at untethering the spinal cord. In asymptomatic patients, this can protect against the long-term development of neurological deficits. In symptomatic patients, this can halt or limit the progression of existing symptoms. The aim of this study is to examine all paediatric and adult patients diagnosed with OSD and treated in the Department of Neurosurgery at the University Medical Centre Ljubljana during the 5-year period of 2016–2021. All patients diagnosed with OSD during this period were included in the study. Patient characteristics, treatment modalities and outcomes were studied with the aim of describing the differences between the paediatric and adult population and defining the rationality of treating these pathological conditions. We included in the study 52 patients with 64 occult dysraphic lesions. Adults (>18 years old) represented 15/52 (28.8%) of all patients, while 37/52 (71.8%) were children. The most common OSDs were conus lipomas, followed by dermal sinus tracts, filum terminale lipomas and split cord malformations. Surgical treatment was performed in 35/52 (67.3%) cases, while conservative management was chosen in 17/52 (32.6%) cases. The preoperative presence of symptoms was statistically higher in adults than in children (p = 0.0098). Surgery on complex spinal cord lipomas was statistically related to a higher rate of postoperative neurological complications (p = 0.0002). The treatment of OSD is complex and must be based on knowledge of the developmental anomalies of the spine and spinal cord. Successful surgical treatment relies on microsurgical techniques and the use of neuromonitoring. Successful treatment can prevent or limit the occurrence of neurological problems.