Tools to effectively demonstrate and quantify functional delivery in cellular communication have been lacking. This study reports the use of a fluorescently labeled split Nanoluc reporter system... Show moreTools to effectively demonstrate and quantify functional delivery in cellular communication have been lacking. This study reports the use of a fluorescently labeled split Nanoluc reporter system to demonstrate and quantify functional transfer between cells in vitro and in a subcutaneous tumor mouse model. Our construct allows monitoring of direct, indirect, and specifically extracellular vesicle-mediated functional communication. Show less
Nieland, L.; Solinge, T.S. van; Cheah, P.S.; Morsett, L.M.; Khoury, J. el; Rissman, J.I.; ... ; Abels, E.R. 2022
Despite advances in neurosurgery, chemotherapy and radiotherapy, glioblastoma remains one of the most treatment-resistant CNS malignancies, and the tumour inevitably recurs. The majority of... Show moreDespite advances in neurosurgery, chemotherapy and radiotherapy, glioblastoma remains one of the most treatment-resistant CNS malignancies, and the tumour inevitably recurs. The majority of recurrences appear in or near the resection cavity, usually within the area that received the highest dose of radiation. Many new therapies focus on combatting these local recurrences by implementing treatments directly in or near the tumour bed. In this Review, we discuss the latest developments in local therapy for glioblastoma, focusing on recent preclinical and clinical trials. The approaches that we discuss include novel intraoperative techniques, various treatments of the surgical cavity, stereotactic injections directly into the tumour, and new developments in convection-enhanced delivery and intra-arterial treatments.Glioblastoma is one of the most treatment-resistant CNS malignancies, and the tumour inevitably recurs, usually in or near the resection cavity. Here, the authors discuss local therapies for glioblastoma, examining treatment of the resection cavity and other direct approaches to the tumour. Show less
Mahjoum, S.; Rufino-Ramos, D.; Almeida, L.P. de; Broekman, M.L.D.; Breakefield, X.O.; Solinge, T.S. van 2021
The central nervous system (CNS) consists of a heterogeneous population of cells with highly specialized functions. For optimal functioning of the CNS, in disease and in health, intricate... Show moreThe central nervous system (CNS) consists of a heterogeneous population of cells with highly specialized functions. For optimal functioning of the CNS, in disease and in health, intricate communication between these cells is vital. One important mechanism of cellular communication is the release and uptake of extracellular vesicles (EVs). EVs are membrane enclosed particles actively released by cells, containing a wide array of proteins, lipids, RNA, and DNA. These EVs can be taken up by neighboring or distant cells, and influence a wide range of processes. Due to the complexity and relative inaccessibility of the CNS, our current understanding of the role of EVs is mainly derived in vitro work. However, recently new methods and techniques have opened the ability to study the role of EVs in the CNS in vivo. In this review, we discuss the current developments in our understanding of the role of EVs in the CNS in vivo. Show less
Solinge, T.S. van; Abels, E.R.; Haar, L.L. van de; Hanlon, K.S.; Maas, S.L.N.; Schnoor, R.; ... ; Broekman, M.L.D. 2020
Introduction: Glioma cells exert influence over the tumor-microenvironment in part through the release of extracellular vesicles (EVs), membrane-enclosed structures containing proteins, lipids, and... Show moreIntroduction: Glioma cells exert influence over the tumor-microenvironment in part through the release of extracellular vesicles (EVs), membrane-enclosed structures containing proteins, lipids, and RNAs. In this study, we evaluated the function of Ras-associated protein 27a (Rab27a) in glioma and evaluated the feasibility of assessing its role in EV release in glioma cells in vitro and in vivo.Methods: Rab27a was knocked down via a short hairpin RNA (shRNA) stably expressed in mouse glioma cell line GL261, with a scrambled shRNA as control. EVs were isolated by ultracentrifugation and quantified with Nanoparticle Tracking Analysis (NTA) and Tunable Resistive Pulse Sensing (TRPS). CellTiter-Glo viability assays and cytokine arrays were used to evaluate the impact of Rab27a knockdown. GL261.shRab27a cells and GL261.shControl were implanted into the left striatum of eight mice to assess tumor growth and changes in the tumor microenvironment.Results: Knockdown of Rab27a in GL261 glioma cells decreased the release of small EVs isolated at 100,000 x g in vitro (p = 0.005), but not the release of larger EVs, isolated at 10,000 x g. GL261.shRab27a cells were less viable compared to the scramble control in vitro (p < 0.005). A significant increase in CCL2 expression in shRab27a GL261 cells was also observed (p < 0.001). However, in vivo there was no difference in tumor growth or overall survival between the two groups, while shRab27a tumors showed lower proliferation at the tumor borders. Decreased infiltration of IBA1 positive macrophages and microglia, but not FoxP3 positive regulatory T cells was observed.Conclusion: Rab27a plays an important role in the release of small EVs from glioma cells, and also in their viability and expression of CCL2 in vitro. As interference in Rab27a expression influences glioma cell viability and expression profiles, future studies should be cautious in using the knockdown of Rab27a as a means of studying the role of small EVs in glioma growth. Show less
Maas, S.L.N.; Solinge, T.S. van; Schnoor, R.; Yekula, A.; Senders, J.T.; Vrij, J. de; ... ; Broekman, M.L.D. 2020
Simple SummaryIn Glioblastoma (GB), a malignant tumor of the central nervous system, diagnosis can currently only be obtained via tissue biopsy. In this study we were able to isolate GB derived... Show moreSimple SummaryIn Glioblastoma (GB), a malignant tumor of the central nervous system, diagnosis can currently only be obtained via tissue biopsy. In this study we were able to isolate GB derived extracellular vesicles (EVs) in the blood, after patients received 5-aminolevulinic acid (5-ALA) before surgery. This isolation is based on fluorescence caused by the accumulation of fluorescent protoporphyrin IX (PpIX) in these EVs. We show that these EVs contain various GB-related micro RNAs. While there are many ways in which our technique needs to be improved before being able to be implemented in the clinic, this study shows that detecting and analyzing circulating GB-derived EVs based on PpIX fluorescence is feasible. In the future, our technique could be developed to diagnose and monitor GB via blood samples instead of a brain biopsy.Background: In glioblastoma (GB), tissue is required for accurate diagnosis and subtyping. Tissue can be obtained through resection or (stereotactic) biopsy, but these invasive procedures provide risks for patients. Extracellular vesicles (EVs) are small, cell-derived vesicles that contain miRNAs, proteins, and lipids, and possible candidates for liquid biopsies. GB-derived EVs can be found in the blood of patients, but it is difficult to distinguish them from circulating non-tumor EVs. 5-aminolevulinic acid (5-ALA) is orally administered to GB patients to facilitate tumor visualization and maximal resection, as it is metabolized to fluorescent protoporphyrin IX (PpIX) that accumulates in glioma cells. In this study, we assessed whether PpIX accumulates in GB-derived EVs and whether these EVs could be isolated and characterized to enable a liquid biopsy in GB. Methods: EVs were isolated from the conditioned media of U87 cells treated with 5-ALA by differential ultracentrifugation. Blood samples were collected and processed from healthy controls and patients undergoing 5-ALA guided surgery for GB. High-resolution flow cytometry (hFC) enabled detection and sorting of PpIX-positive EVs, which were subsequently analyzed by digital droplet PCR (ddPCR). Results: PpIX-positive EVs could be detected in conditioned cell culture media as well as in patient samples after administration of 5-ALA. By using hFC, we could sort the PpIX-positive EVs for further analysis with ddPCR, which indicated the presence of EVs and GB-associated miRNAs. Conclusion: GB-derived EVs can be isolated from the plasma of GB patients by using 5-ALA induced fluorescence. Although many challenges remain, our findings show new possibilities for the development of blood-based liquid biopsies in GB patients. Show less
Solinge, T.S. van; Muskens, I.S.; Kavouridis, V.K.; Gormley, W.B.; Mekary, R.A.; Broekman, M.L.D.; Arnaout, O. 2020
Intraventricular hemorrhage (IVH) is an independent poor prognostic factor in subarachnoid and intra-parenchymal hemorrhage. The use of intraventricular fibrinolytics (IVF) has long been debated,... Show moreIntraventricular hemorrhage (IVH) is an independent poor prognostic factor in subarachnoid and intra-parenchymal hemorrhage. The use of intraventricular fibrinolytics (IVF) has long been debated, and its exact effects on outcomes are unknown. A systematic review and meta-analysis were performed in accordance with the PRISMA guidelines to assess the impact of IVF after non-traumatic IVH on mortality, functional outcome, intracranial bleeding, ventriculitis, time until clearance of third and fourth ventricles, obstruction of external ventricular drains (EVD), and shunt dependency. Nineteen studies were included in the meta-analysis, totaling 1020 patients. IVF was associated with lower mortality (relative risk [RR] 0.58; 95% confidence interval [CI] 0.47-0.72), fewer EVD obstructions (RR 0.41; 95% CI 0.22-0.74), and a shorter time until clearance of the ventricles (median difference [MD] - 4.05 days; 95% CI - 5.52 to - 2.57). There was no difference in good functional outcome, RR 1.41 (95% CI 0.98-2.03), or shunt dependency, RR 0.93 (95% CI 0.70-1.22). Correction for publication bias predicted an increased risk of intracranial bleeding, RR 1.67 (95% CI 1.01-2.74) and a lower risk of ventriculitis, RR 0.68 (95% CI 0.45-1.03) in IVH patients treated with IVF. IVF was associated with improved survival, faster clearance of blood from the ventricles and fewer drain obstructions, but further research is warranted to elucidate the effects on ventriculitis, long-term functional outcomes, and re-hemorrhage. Show less
