A Novel Approach for Glioblastoma Treatment by Combining Apoptosis Inducers (TMZ, MTX, and Cytarabine) with E.V.A. (Eltanexor, Venetoclax, and A1210477) Inhibiting XPO1, Bcl-2, and Mcl-1.

Adjuvant treatment for Glioblastoma Grade 4 with Temozolomide (TMZ) inevitably fails due to therapeutic resistance, necessitating new approaches. Apoptosis induction in GB cells is inefficient, due to an excess of anti-apoptotic XPO1/Bcl-2-family proteins. We assessed TMZ, Methotrexate (MTX), and Cytarabine (Ara-C) (apoptosis inducers) combined with XPO1/Bcl-2/Mcl-1-inhibitors (apoptosis rescue) in GB cell lines and primary GB stem-like cells (GSCs). Using CellTiter-Glo® and Caspase-3 activity assays, we generated dose-response curves and analyzed the gene and protein regulation of anti-apoptotic proteins via PCR and Western blots. Optimal drug combinations were examined for their impact on the cell cycle and apoptosis induction via FACS analysis, paralleled by the assessment of potential toxicity in healthy mouse brain slices. Ara-C and MTX proved to be 150- to 10,000-fold more potent in inducing apoptosis than TMZ. In response to inhibitors Eltanexor (XPO1; E), Venetoclax (Bcl-2; V), and A1210477 (Mcl-1; A), genes encoding for the corresponding proteins were upregulated in a compensatory manner. TMZ, MTX, and Ara-C combined with E, V, and A evidenced highly lethal effects when combined. As no significant cell death induction in mouse brain slices was observed, we conclude that this drug combination is effective in vitro and expected to have low side effects in vivo.

Prostacyclin Released by Cancer-Associated Fibroblasts Promotes Immunosuppressive and Pro-Metastatic Macrophage Polarization in the Ovarian Cancer Microenvironment.

Metastasis of high-grade ovarian carcinoma (HGSC) is orchestrated by soluble mediators of the tumor microenvironment. Here, we have used transcriptomic profiling to identify lipid-mediated signaling pathways encompassing 41 ligand-synthesizing enzymes and 23 cognate receptors in tumor, immune and stroma cells from HGSC metastases and ascites. Due to its strong association with a poor clinical outcome, prostacyclin (PGI2) synthase (PTGIS) is of particular interest in this signaling network. PTGIS is highly expressed by cancer-associated fibroblasts (CAF), concomitant with elevated PGI2 synthesis, whereas tumor-associated macrophages (TAM) exhibit the highest expression of its surface receptor (PTGIR). PTGIR activation by PGI2 agonists triggered cAMP accumulation and induced a mixed-polarization macrophage phenotype with altered inflammatory gene expression, including CXCL10 and IL12A repression, as well as reduced phagocytic capability. Co-culture experiments provided further evidence for the interaction of CAF with macrophages via PGI2, as the effect of PGI2 agonists on phagocytosis was mitigated by cyclooxygenase inhibitors. Furthermore, conditioned medium from PGI2-agonist-treated TAM promoted tumor adhesion to mesothelial cells and migration in a PTGIR-dependent manner, and PTGIR activation induced the expression of metastasis-associated and pro-angiogenic genes. Taken together, our study identifies a PGI2/PTGIR-driven crosstalk between CAF, TAM and tumor cells, promoting immune suppression and a pro-metastatic environment.

An anti-inflammatory eicosanoid switch mediates the suppression of type-2 inflammation by helminth larval products.

Eicosanoids are key mediators of type-2 inflammation, e.g., in allergy and asthma. Helminth products have been suggested as remedies against inflammatory diseases, but their effects on eicosanoids are unknown. Here, we show that larval products of the helminth Heligmosomoides polygyrus bakeri (HpbE), known to modulate type-2 responses, trigger a broad anti-inflammatory eicosanoid shift by suppressing the 5-lipoxygenase pathway, but inducing the cyclooxygenase (COX) pathway. In human macrophages and granulocytes, the HpbE-driven induction of the COX pathway resulted in the production of anti-inflammatory mediators [e.g., prostaglandin E2 (PGE2) and IL-10] and suppressed chemotaxis. HpbE also abrogated the chemotaxis of granulocytes from patients suffering from aspirin-exacerbated respiratory disease (AERD), a severe type-2 inflammatory condition. Intranasal treatment with HpbE extract attenuated allergic airway inflammation in mice, and intranasal transfer of HpbE-conditioned macrophages led to reduced airway eosinophilia in a COX/PGE2-dependent fashion. The induction of regulatory mediators in macrophages depended on p38 mitogen-activated protein kinase (MAPK), hypoxia-inducible factor-1α (HIF-1α), and Hpb glutamate dehydrogenase (GDH), which we identify as a major immunoregulatory protein in HpbE Hpb GDH activity was required for anti-inflammatory effects of HpbE in macrophages, and local administration of recombinant Hpb GDH to the airways abrogated allergic airway inflammation in mice. Thus, a metabolic enzyme present in helminth larvae can suppress type-2 inflammation by inducing an anti-inflammatory eicosanoid switch, which has important implications for the therapy of allergy and asthma.

Design and Synthesis of Highly Active Peroxisome Proliferator-Activated Receptor (PPAR) ß/δ Inverse Agonists with Prolonged Cellular Activity.

Based on 3-(((4-(hexylamino)-2-methoxyphenyl)amino)sulfonyl)-2-thiophenecarboxylic acid methyl ester (ST247, compound 2), a recently described peroxisome proliferator-activated receptor (PPAR)ß/δ-selective inverse agonist, we designed and synthesized a series of structurally related ligands. The structural modifications presented herein ultimately resulted in a series of ligands that display increased cellular activity relative to 2. Moreover, with methyl 3-(N-(2-(2-ethoxyethoxy)-4-(hexylamino)phenyl)sulfamoyl)thiophene-2-carboxylate (PT-S264, compound 9 u), biologically relevant plasma concentrations in mice were achieved. The compounds presented in this study will provide useful novel tools for future investigations addressing the role of PPARß/δ in physiological and pathophysiological processes.

Nilotinib is more potent than imatinib for treating plexiform neurofibroma in vitro and in vivo.

Plexiform neurofibromas (PNFs) are benign nerve sheath tumors mostly associated with neurofibromatosis type 1. They often extend through multiple layers of tissue and therefore cannot be treated satisfactorily by surgery. Nilotinib is a tyrosine kinase inhibitor used to treat leukemia, with advantages over the prototype imatinib in terms of potency and selectivity towards BCR-ABL, and the DDR, PDGFR, and KIT receptor kinases. In this study, we compared efficacies of the two drugs on cultured cells of PNF in vitro and on xenografted tumor fragments on sciatic nerve of athymic nude mice. Xenografts were monitored weekly using a high resolution ultrasound measurement. Treatment with nilotinib at a daily dose of 100 mg/kg for four weeks led to a reduction of the graft sizesstd by 68±7% in the 8 treated mice, significantly more than the 33±8% reduction in the 8 untreated mice (P<0.05) and the 47±15% in the 7 mice treated with imatinib (P<0.05). The peak plasma nilotinib concentration 6.6±1.1 µM is within the pharmacological range of clinical application. Imatinib, but not nilotinib significantly hindered body weight increase of the mice and elevated cytotoxicity of mouse spleen cells (P<0.05). Our results suggest that nilotinib may be more potent than imatinib for treating PNFs and may also be better tolerated. Imatinib seems to have some off-target effect in elevating immunity.

NK and CD4+ T cell changes in blood after seizures in temporal lobe epilepsy.

UNLABELLED: Immunological phenomena may affect the course of focal epilepsy. We analyzed prospectively the pre- and postictal distribution of leukocyte subsets in epileptic patients. METHODS: Twenty-two patients (age 36.6+/-10.8 years, 50% men) with temporal lobe epilepsy were included. Distribution of leukocyte subsets and serum levels of epinephrine were measured in peripheral blood immediately and 24 h after seizures and compared to baseline values. RESULTS: In the immediate postictal state (10+/-6 min), we observed a significant relative increase of total leukocytes (42%, p=0.0004), neutrophil leukocytes (55%, p=0.0007), total lymphocytes (45%, p=0.0019), natural killer (NK) cells (104%, p=0.0017), and epinephrine (454%, p=0.0014). CD4(+) T cells decreased by 13% (p=0.0113). These postictal changes remained significant considering only complex partial seizures (n=17). The alterations were more pronounced in patients with hippocampal sclerosis. Treatment with valproic acid (VPA) was accompanied by a greater postictal decrease of CD4(+) T cells (25% compared to 5% in patients without VPA, p=0.041) while treatment with levetiracetam (LEV) correlated with a low postictal increase of NK-like T cells (4% versus 41%, p=0.016). Twenty-four hours after the seizures the alterations had resolved. CONCLUSION: Profound postictal changes in the immune cell composition of the peripheral blood may have been mediated by epinephrine release. The greater immune response in patients with mesial temporal lobe epilepsy due to hippocampal sclerosis may reflect a close relationship between mesial temporal structures and the sympathetic nerve system. VPA and LEV may have an impact on seizure induced immunological changes.

Pan-neurotrophin receptor p75 contributes to neuronal hyperreactivity and airway inflammation in a murine model of experimental asthma.

Bronchial asthma represents a severe chronic inflammatory disease with increasing prevalence. The pathogenesis is characterized by complex neuroimmune dysregulation. Although the immunopathogenesis of the disease has been extensively studied, the nature of neuronal dysfunction still remains poorly understood. Recent data indicate that neurotrophins contribute to airway inflammation, broncho-obstruction and airway hyperresponsiveness. Using an established murine model of allergic bronchial asthma, the contribution of the pan-neurotrophin receptor p75(NTR) was defined. This receptor is expressed both in normal and asthmatic lungs and airways. Analysis of p75(NTR-/-) mice, as well as in vivo blocking of p75(NTR), revealed that airway inflammation is to a large extent dependent upon functional receptor expression. Furthermore, neuronal hyperreactivity depends entirely on this receptor. Based on these data, a novel molecular pathway in the neuroimmune pathogenesis of bronchial asthma could be defined.

Augmentation of allergic early-phase reaction by nerve growth factor.

The allergic early-phase reaction, a hallmark of allergic bronchial asthma, is caused by allergen and immunoglobulin E-dependent mediator release from mast cells. It was previously shown that nerve growth factor (NGF) contributes to acute airway inflammation. This study further investigates the role of NGF in the allergic early-phase reaction using a well-established mouse model of ovalbumin-induced allergic airway inflammation. Treatment of sensitized and aerosol challenged BALB/c mice with blocking anti-NGF antibodies inhibited allergen-induced early-phase reaction and suppressed airway inflammation. Transgenic mice constitutively overexpressing NGF in the airways (Clara-cell secretory protein promoter [CCSP]-NGF-tg) were employed and compared with wild-type animals. In sensitized and challenged CCSP-NGF-tg mice, early-phase reaction, airway inflammation, as well as percental relative increases in serotonin levels were augmented compared with wild-type mice. These effects were paralleled by increased serotonin levels in the airways, whereas immunoglobulin E levels remained unaffected. Furthermore, CCSP-NGF-tg mice developed an increased reactivity of sensory neurons in response to inhaled capsaicin demonstrating NGF-mediated neuronal plasticity. These data provide evidence for the functional role of NGF in the development of allergic early phase responses in the airways and the lung.