Search

The alkylating agent temozolomide (TMZ) is the first-line chemotherapeutic for glioblastoma (GBM), a common and aggressive primary brain tumor in adults. However, its poor stability and unfavorable pharmacokinetic profile limit its clinical efficacy. There is an unmet need to tailor the therapeutic window of TMZ, either through complex derivatization or by utilizing pharmaceutical excipients. To enhance stability and aqueous solubility, we encapsulated TMZ in a p-sulphonatocalix[4]arene (Calix) nanocapsule and used 1H-NMR, LC-MS, and UV–Vis spectroscopy to chart the stability of this novel TMZ@Calix complex according to FDA and European Medicines Agency guidelines. LC-MS/MS plasma stability assays were conducted in mice to further explore the stability profile of TMZ@Calix in vivo. The therapeutic efficacy of TMZ@Calix was compared with that of unbound TMZ in GBM cell lines and patient-derived primary cells with known O6-methylguanine-DNA methyltransferase (MGMT) expression status and in vivo in an intracranial U87 xenograft mouse model. Encapsulation significantly enhanced the stability of TMZ in all conditions tested. TMZ@Calix was more potent than native TMZ at inhibiting the growth of established GBM cell lines and patient-derived primary lines expressing MGMT and highly resistant to TMZ. In vivo, native TMZ was rapidly degraded in mouse plasma, whereas the stability of TMZ@Calix was enhanced threefold with increased therapeutic efficacy in an orthotopic model. In the absence of new effective therapies, this novel formulation is of clinical importance, serving as an inexpensive and highly efficient treatment that could be made readily available to patients with GBM and warrants further preclinical and clinical evaluation.

Supplementary Figure 1 showing 1H-NMR spectra of Calix, TMZ and TMZ@Calix complex

Glioblastoma (GBM) is an aggressive malignant primary brain tumor with limited therapeutic options. We show that the angiotensin II (AngII) type 2 receptor (AT

Glioblastoma (GBM) is an aggressive malignant primary brain tumor with limited therapeutic options. We show that the angiotensin II (AngII) type 2 receptor (AT 2 R) is a therapeutic target for GBM and that AngII, endogenously produced in GBM cells, promotes proliferation through AT 2 R. We repurposed EMA401, an AT 2 R antagonist originally developed as a peripherally restricted analgesic, for GBM and showed that it inhibits the proliferation of AT 2 R-expressing GBM spheroids and blocks their invasiveness and angiogenic capacity. The crystal structure of AT 2 R bound to EMA401 was determined and revealed the receptor to be in an active-like conformation with helix-VIII blocking G-protein or β-arrestin recruitment. The architecture and interactions of EMA401 in AT 2 R differ drastically from complexes of AT 2 R with other relevant compounds. To enhance central nervous system (CNS) penetration of EMA401, we exploited the crystal structure to design an angiopep-2–tethered EMA401 derivative, A3E. A3E exhibited enhanced CNS penetration, leading to reduced tumor volume, inhibition of proliferation, and increased levels of apoptosis in an orthotopic xenograft model of GBM.

Glioblastoma multiforme (GBM) is the most common and aggressive primary malignant brain tumor. Maximal surgical resection followed by radiotherapy and concomitant chemotherapy with temozolomide remains the first-line therapy, prolonging the survival of patients by an average of only 2.5 months. There is therefore an urgent need for novel therapeutic strategies to improve clinical outcomes. Reactive oxygen species (ROS) are an important contributor to GBM development. Here, we describe the rational design and synthesis of a stable hybrid molecule tethering two ROS regulating moieties, with the aim of constructing a chemopreventive and anticancer chemical entity that retains the properties of the parent compounds. We utilized the selective AT1R antagonist losartan, leading to the inhibition of ROS levels, and the antioxidant flavonoid quercetin. In GBM cells, we show that this hybrid retains the binding potential of losartan to the AT1R through competition-binding experiments and simultaneously exhibits ROS inhibition and antioxidant capacity similar to native quercetin. In addition, we demonstrate that the hybrid is able to alter the cell cycle distribution of GBM cells, leading to cell cycle arrest and to the induction of cytotoxic effects. Last, the hybrid significantly and selectively reduces cancer cell proliferation and angiogenesis in primary GBM cultures with respect to the isolated parent components or their simple combination, further emphasizing the potential utility of the current hybridization approach in GBM.

Glioblastoma (GBM) is a primary malignant brain tumor with poor clinical outcomes. Standard of care consists of surgical debulking followed by radiation and temozolomide, but the tumor invariably recurs, and median survival is only ~18 months. Repurposing drugs used for the treatment of other diseases is a promising avenue to identify novel treatments for this highly aggressive form of cancer. One such class of compounds is angiotensin II (AngII) receptor blockers, commonly used to control blood pressure. We show that ~80% of primary human GBM express the angiotensin II type 2 receptor (AT2R). In the presence of AngII, inhibition of AT2R using either PD123319 or EMA401 significantly inhibits GBM proliferation. This effect was lost in GBM cells with CRISPR/Cas9 mediated knockdown of AT2R. EMA401 inhibited invasion, angiogenesis, reduced GBM spheroid growth and induced apoptosis through caspase 3/7 activation. Furthermore, EMA401 induced changes in a number of growth regulatory pathways including apoptosis, DNA replication and focal adhesion. The crystal structure of AT2R bound to EMA401 revealed the receptor to be in an active-like conformation with helix-VIII blocking G protein or β-arrestin recruitment. We demonstrate that the architecture and interaction of EMA401 with AT2R differs drastically from complexes of AT2R with other compounds. Conjugation of EMA401 to angiopep-2 enhanced its blood brain barrier passage and reduced tumor volume in an orthotopic xenograft model of GBM. Targeting AT2R is a novel therapeutic strategy to treat GBM that should be explored in patients.

Cancer occupies a high rank in the global morbidity and mortality scale with glioblastoma multiforme (GBM) accounting for almost 80% of all primary tumors of the brain. Despite the increasing availability of targeted and immunotherapeutic agents, chemotherapy still plays an important role in the treatment of neoplastic diseases. Limitations to the effective use of chemotherapy such as low aqueous solubility and high toxicity have directed the scientific community's interest to the development of new therapeutic agents with enhanced efficacy and limited toxicity. Supramolecular chemistry has offered an alternative way on the design and development of new therapeutic agents as a result of their unique properties. Supramolecules can be used as drug carriers since their cavities can host a wide range of small drugs and surpass in this way the drawbacks of current therapeutic agents. Herein, we present the principles that should be followed for the encapsulation of small drugs in supramolecules with enhanced physicochemical properties and increased efficacy against glioblastoma multiforme.

Cancer occupies a high rank in the global morbidity and mortality scale with glioblastoma multiforme (GBM) accounting for almost 80% of all primary tumors of the brain. Despite the increasing availability of targeted and immunotherapeutic agents, chemotherapy still plays an important role in the treatment of neoplastic diseases. Limitations to the effective use of chemotherapy such as low aqueous solubility and high toxicity have directed the scientific community's interest to the development of new therapeutic agents with enhanced efficacy and limited toxicity. Supramolecular chemistry has offered an alternative way on the design and development of new therapeutic agents as a result of their unique properties. Supramolecules can be used as drug carriers since their cavities can host a wide range of small drugs and surpass in this way the drawbacks of current therapeutic agents. Herein, we present the principles that should be followed for the encapsulation of small drugs in supramolecules with enhanced physicochemical properties and increased efficacy against glioblastoma multiforme.

The role of astrocytes in the progression of Alzheimer's disease (AD) remains poorly understood. We assessed the consequences of ablating astrocytic proliferation in 9 months old double transgenic APP23/GFAP‐TK mice. Treatment of these mice with the antiviral agent ganciclovir conditionally ablates proliferating reactive astrocytes. The loss of proliferating astrocytes resulted in significantly increased levels of monomeric amyloid‐β (Aβ) in brain homogenates, associated with reduced enzymatic degradation and clearance mechanisms. In addition, our data revealed exacerbated memory deficits in mice lacking proliferating astrocytes concomitant with decreased levels of synaptic markers and higher expression of pro‐inflammatory cytokines. Our data suggest that loss of reactive astrocytes in AD aggravates amyloid pathology and memory loss, possibly via disruption of amyloid clearance and enhanced neuroinflammation., Main points Depletion of proliferating astrocytes in APP23 mice leads to reduced amyloid degradation.Loss of proliferating astrocytes results in increased memory deficits associated with synaptic and neuronal loss.Ablation of proliferating astrocytes increases the expression of pro‐inflammatory cytokines.

The alkylating agent temozolomide (TMZ) is the first-line chemotherapeutic for glioblastoma (GBM), a common and aggressive primary brain tumor in adults. However, its poor stability and unfavorable pharmacokinetic profile limit its clinical efficacy. There is an unmet need to tailor the therapeutic window of TMZ, either through complex derivatization or by utilizing pharmaceutical excipients. To enhance stability and aqueous solubility, we encapsulated TMZ in a p-sulphonatocalix[4]arene (Calix) nanocapsule and used 1H-NMR, LC-MS, and UV–Vis spectroscopy to chart the stability of this novel TMZ@Calix complex according to FDA and European Medicines Agency guidelines. LC-MS/MS plasma stability assays were conducted in mice to further explore the stability profile of TMZ@Calix in vivo. The therapeutic efficacy of TMZ@Calix was compared with that of unbound TMZ in GBM cell lines and patient-derived primary cells with known O6-methylguanine-DNA methyltransferase (MGMT) expression status and in vivo in an intracranial U87 xenograft mouse model. Encapsulation significantly enhanced the stability of TMZ in all conditions tested. TMZ@Calix was more potent than native TMZ at inhibiting the growth of established GBM cell lines and patient-derived primary lines expressing MGMT and highly resistant to TMZ. In vivo, native TMZ was rapidly degraded in mouse plasma, whereas the stability of TMZ@Calix was enhanced threefold with increased therapeutic efficacy in an orthotopic model. In the absence of new effective therapies, this novel formulation is of clinical importance, serving as an inexpensive and highly efficient treatment that could be made readily available to patients with GBM and warrants further preclinical and clinical evaluation.

Neuroinflammation and oxidative stress are involved in the pathogenesis of Alzheimer's, Parkinson's and Huntington's diseases. This is caused mainly by the presence of misfolded proteins which act as a catalyst for the activation and sustained activity of glial cells. Activated microglial cells are involved in both the initiation and progression of the disease, which will lead to the release of many pro-inflammatory mediators which induce neuronal injury and death. In addition, astrocytes may play an important role; their ability to secrete important neurotrophic factors may be impaired, while the release of pro-inflammatory cytokines may contribute to the cellular destruction. Activation of the innate and adaptive immune responses is evident in these diseases, while the production of reactive oxygen and nitrogen species will contribute to the neuronal destruction