Hyaluronic acid-based hydrogels loaded with chemoattractant and anticancer drug - new formulation for attracting and tackling glioma cells.

Over the last few years, significant interest has emerged in the development of localised therapeutic strategies for the treatment of glioblastoma (GBM). The concept of attracting and trapping residual tumour cells within a confined area to facilitate their eradication has developed progressively. Herein, we propose a new design of hyaluronic acid-based hydrogel which can be utilized as a matrix containing a soluble chemoattractant to attract residual glioma cells and chemotherapeutic agents to eradicate them in a less invasive and more efficient way compared to the currently available methods. Hydrogels were prepared at different crosslinking densities, e.g. low and high density, by crosslinking hyaluronic acid with various concentrations of adipic acid dihydrazide and U87MG GBM cell morphology, survival and CD44 expression were evaluated. As a proof-of-concept, hydrogels were loaded with a small peptide chemokine, human urotensin II (hUII), and the migration and survival of U87MG GBM cells were studied. Chemoattractant-containing hydrogels were also loaded with chemotherapeutic drugs to promote cell death in culture. The results showed that U87MG cells were able to invade the hydrogel network and to migrate in response to the chemoattractant hUII. In addition, in static condition, hydrogels loaded with doxorubicin demonstrated significant cytotoxicity leading to less than 80% U87MG cell viability after 48 hours when compared to the control sample. In addition, in in vitro invasive assays, it was originally shown that the chemoattractant effect of hUII can be effective before the cytotoxic action of doxorubicin on the U87MG cells trapped in the hydrogel. Our results provide new insights into a promising approach which can be readily translated in vivo for the treatment of one of the most devastating brain tumours.

Chemotactic cell migration: the core autophagy protein ATG9A is at the leading edge.

Accumulating data indicate that several components of the macroautophagy/autophagy machinery mediate additional functions, which do not depend on autophagosome biogenesis or lysosomal cargo degradation. In this context, we found that the core autophagy protein ATG9A participates in the chemotactic movement of several cell lines, including highly invasive glioblastoma cells. Accordingly, ATG9A-depleted cells are unable to form large and persistent leading-edge protrusions. By the design of an ATG9A-pHluorin construct and TIRF imaging, we established that ATG9A-positive vesicles are targeted toward the migration front, where their exocytosis is synchronized with protrusive activity. We finally demonstrated that ATG9A, through its interaction with clathrin adaptor complexes, controls the delivery of ITGB1 (integrin subunit beta 1) to the migration front and normal adhesion dynamics. Together, our work indicates that ATG9A protein has a wider role than anticipated and constitutes a critical component of vesicular trafficking allowing the expansion of cell protrusions and their anchorage to the extracellular matrix.

The core autophagy protein ATG9A controls dynamics of cell protrusions and directed migration.

Chemotactic migration is a fundamental cellular behavior relying on the coordinated flux of lipids and cargo proteins toward the leading edge. We found here that the core autophagy protein ATG9A plays a critical role in the chemotactic migration of several human cell lines, including highly invasive glioma cells. Depletion of ATG9A protein altered the formation of large and persistent filamentous actin (F-actin)-rich lamellipodia that normally drive directional migration. Using live-cell TIRF microscopy, we demonstrated that ATG9A-positive vesicles are targeted toward the migration front of polarized cells, where their exocytosis correlates with protrusive activity. Finally, we found that ATG9A was critical for efficient delivery of ß1 integrin to the leading edge and normal adhesion dynamics. Collectively, our data uncover a new function for ATG9A protein and indicate that ATG9A-positive vesicles are mobilized during chemotactic stimulation to facilitate expansion of the lamellipodium and its anchorage to the extracellular matrix.

A Panax quinquefolius-Based Preparation Prevents the Impact of 5-FU on Activity/Exploration Behaviors and Not on Cognitive Functions Mitigating Gut Microbiota and Inflammation in Mice.

Chemotherapy-related cognitive impairment (CRCI) and fatigue constitute common complaints among cancer patient survivors. Panax quinquefolius has been shown to be effective against fatigue in treated cancer patients. We developed a behavioral C57Bl/6j mouse model to study the role of a Panax quinquefolius-based solution containing vitamin C (Qiseng®) or vitamin C alone in activity/fatigue, emotional reactivity and cognitive functions impacted by 5-Fluorouracil (5-FU) chemotherapy. 5-FU significantly reduces the locomotor/exploration activity potentially associated with fatigue, evokes spatial cognitive impairments and leads to a decreased neurogenesis within the hippocampus (Hp). Qiseng® fully prevents the impact of chemotherapy on activity/fatigue and on neurogenesis, specifically in the ventral Hp. We observed that the chemotherapy treatment induces intestinal damage and inflammation associated with increased levels of Lactobacilli in mouse gut microbiota and increased expression of plasma pro-inflammatory cytokines, notably IL-6 and MCP-1. We demonstrated that Qiseng® prevents the 5-FU-induced increase in Lactobacilli levels and further compensates the 5-FU-induced cytokine release. Concomitantly, in the brains of 5-FU-treated mice, Qiseng® partially attenuates the IL-6 receptor gp130 expression associated with a decreased proliferation of neural stem cells in the Hp. In conclusion, Qiseng® prevents the symptoms of fatigue, reduced chemotherapy-induced neuroinflammation and altered neurogenesis, while regulating the mouse gut microbiota composition, thus protecting against intestinal and systemic inflammation.

PAK3 is a key signature gene of the glioma proneural subtype and affects its proliferation, differentiation and growth.

PURPOSE: Gliomas are the most lethal adult primary brain cancers. Recent advances in their molecular characterization have contributed to a better understanding of their pathophysiology, but there is still a need to identify key genes controling glioma cell proliferation and differentiation. The p21-activated kinases PAK1 and PAK2 play essential roles in cell division and brain development and are well-known oncogenes. In contrast, the role of PAK3 in cancer is poorly understood. It is known, however, that this gene is involved in brain ontogenesis and has been identified as a gene of the proneural subtype signature in glioblastomas. METHODS: To better understand the role of PAK kinases in the pathophysiology of gliomas, we conducted expression analyses by querying multiple gene expression databases and analyzing primary human glioma samples. We next studied PAK3 expression upon differentiation in patient-derived cell lines (PDCLs) and the effects of PAK3 inhibition by lentiviral-mediated shRNA on glioma cell proliferation, differentiation and tumor growth. RESULTS: We show that contrary to PAK1 and PAK2, high PAK3 expression positively correlates with a longer survival of glioma patients. We also found that PAK3 displays differential expression patterns between glioma sub-groups with a higher expression in 1p/19q-codeleted oligodendrogliomas, and is highly expressed in tumors and PDCLs of the proneural subtype. In PDCLs, high PAK3 expression negatively correlated with proliferation and positively correlated with neuronal differentiation. Inhibition of PAK3 expression increased PDCL proliferation and glioma tumor growth in nude mice. CONCLUSIONS: Our results indicate that PAK3 plays a unique role among PAKs in glioma development and may represent a potential therapeutic target.

Targeting the Urotensin II/UT G Protein-Coupled Receptor to Counteract Angiogenesis and Mesenchymal Hypoxia/Necrosis in Glioblastoma.

Glioblastomas (GBMs) are the most common primary brain tumors characterized by strong invasiveness and angiogenesis. GBM cells and microenvironment secrete angiogenic factors and also express chemoattractant G protein-coupled receptors (GPCRs) to their advantage. We investigated the role of the vasoactive peptide urotensin II (UII) and its receptor UT on GBM angiogenesis and tested potential ligand/therapeutic options based on this system. On glioma patient samples, the expression of UII and UT increased with the grade with marked expression in the vascular and peri-necrotic mesenchymal hypoxic areas being correlated with vascular density. In vitro human UII stimulated human endothelial HUV-EC-C and hCMEC/D3 cell motility and tubulogenesis. In mouse-transplanted Matrigel sponges, mouse (mUII) and human UII markedly stimulated invasion by macrophages, endothelial, and smooth muscle cells. In U87 GBM xenografts expressing UII and UT in the glial and vascular compartments, UII accelerated tumor development, favored hypoxia and necrosis associated with increased proliferation (Ki67), and induced metalloproteinase (MMP)-2 and -9 expression in Nude mice. UII also promoted a "tortuous" vascular collagen-IV expressing network and integrin expression mainly in the vascular compartment. GBM angiogenesis and integrin αvß3 were confirmed by in vivo 99mTc-RGD tracer imaging and tumoral capture in the non-necrotic area of U87 xenografts in Nude mice. Peptide analogs of UII and UT antagonist were also tested as potential tumor repressor. Urotensin II-related peptide URP inhibited angiogenesis in vitro and failed to attract vascular and inflammatory components in Matrigel in vivo. Interestingly, the UT antagonist/biased ligand urantide and the non-peptide UT antagonist palosuran prevented UII-induced tubulogenesis in vitro and significantly delayed tumor growth in vivo. Urantide drastically prevented endogenous and UII-induced GBM angiogenesis, MMP, and integrin activations, associated with GBM tumoral growth. These findings show that UII induces GBM aggressiveness with necrosis and angiogenesis through integrin activation, a mesenchymal behavior that can be targeted by UT biased ligands/antagonists.

Association between vasoactive peptide urotensin II in plasma and cerebral vasospasm after aneurysmal subarachnoid hemorrhage: a potential therapeutic target.

OBJECTIVECerebral vasospasm (VS) is a severe complication of aneurysmal subarachnoid hemorrhage (SAH). Urotensin II (UII) is a potent vasoactive peptide activating the urotensin (UT) receptor, potentially involved in brain vascular pathologies. The authors hypothesized that UII/UT system antagonism with the UT receptor antagonist/biased ligand urantide may be associated with post-SAH VS. The objectives of this study were 2-fold: 1) to leverage an experimental mouse model of SAH with VS in order to study the effect of urotensinergic system antagonism on neurological outcome, and 2) to investigate the association between plasma UII level and symptomatic VS after SAH in human patients.METHODSA mouse model of SAH was used to study the impacts of UII and the UT receptor antagonist/biased ligand urantide on VS and neurological outcome. Then a clinical study was conducted in the setting of a neurosurgical intensive care unit. Plasma UII levels were measured in SAH patients daily for 9 days, starting on the 1st day of hospitalization, and were compared with plasma UII levels in healthy volunteers.RESULTSIn the mouse model, urantide prevented VS as well as SAH-related fine motor coordination impairment. Seventeen patients with SAH and external ventricular drainage were included in the clinical study. The median plasma UII level was 43 pg/ml (IQR 14-80 pg/ml). There was no significant variation in the daily median plasma UII level (median value for the 17 patients) from day 0 to day 8. The median level of plasma UII during the 9 first days post-SAH was higher in patients with symptomatic VS than in patients without VS (77 pg/ml [IQR 33.5-111.5 pg/ml] vs 37 pg/ml [IQR 21-46 pg/ml], p < 0.05). Concerning daily measures of plasma UII levels in VS, non-VS patients, and healthy volunteers, we found a significant difference between SAH patients with VS (median 66 pg/ml [IQR 30-110 pg/ml]) and SAH patients without VS (27 pg/ml [IQR 15-46 pg/ml], p < 0.001) but no significant difference between VS patients and healthy volunteers (44 pg/ml [IQR 27-51 pg/ml]) or between non-VS patients and healthy volunteers.CONCLUSIONSThe results of this study suggest that UT receptor antagonism with urantide prevents VS and improves neurological outcome after SAH in mice and that an increase in plasma UII is associated with cerebral VS subsequent to SAH in humans. The causality link between circulating UII and VS after SAH remains to be established, but according to our data the UT receptor is a potential therapeutic target in SAH.