Epha2 expression in bone sarcomas: Bioinformatic analyses and preclinical characterization in patient-derived models of osteosarcoma, ewing’s sarcoma and chondrosarcoma

Bone sarcomas are a group of heterogeneous malignant mesenchymal tumors. Complete surgical resection is still the cornerstone of treatment, but, in the advanced/unresectable setting, their management remains challenging and not significantly improved by target- and immuno-therapies. We focused on the tyrosine kinase Eph type-A receptor-2 (EphA2), a key oncoprotein implicated in self-renewal, angiogenesis, and metastasis, in several solid tumors and thus representing a novel potential therapeutic target. Aiming at better characterizing its expression throughout the main bone sarcoma histotypes, we investigated EPHA2 expression in the Cancer Cell Lines Encyclopedia and in public datasets with clinical annotations. looking for correlations with molecular, histopathological and patients’ features and clinical outcomes in a total of 232 osteosarcomas, 197 Ewing’s sarcomas, and 102 chondrosarcomas. We observed EPHA2 expression in bone sarcoma cell lines. We demonstrated higher EPHA2 expression in tumor tissues when compared to normal counterparts. A significant correlation was found between EPHA2 expression and Huvos grade (osteosarcoma) and with worse overall survival (dedifferentiated chondrosarcoma). Next, we characterized EPHA2 expression and activation in bone sarcoma primary tissues and in patient-derived xenografts generated in our laboratory to verify their reliability as in vivo models of osteosarcoma, Ewing’s sarcoma and chondrosarcoma. Furthermore, for the first time, we demonstrated EPHA2 expression in chondrosarcoma, suggesting its potential key role in this histotype. Indeed, we observed a significant dose-dependent antitumor effect of the EphA2-inhibitor ALW-II-41-27 in patient-derived in vitro models. In conclusion, EphA2 targeting represents a promising novel therapeutic strategy against bone sarcomas

Pazopanib and trametinib as a synergistic strategy against osteosarcoma: Preclinical activity and molecular insights

Receptor tyrosine kinases (RTKs) inhibitors’ activity in advanced osteosarcoma is significant but short-lived. To prevent or at least delay drug resistance, we explored a vertical inhibition by combining drugs acting at different levels of the RTK pathways (pazopanib + trametinib). We studied pazopanib + trametinib antitumor activity both in vitro and in vivo (MNNG-HOS and KHOS xenografts in NOD/SCID mice) investigating the molecular mechanisms and potential escapes. The involvement of MAPK-PI3K pathways was validated by Nanostring technology, western blot and by silencing/overexpression experiments. Pazopanib targets were expressed on seven osteosarcoma cell lines and their pathways were activated. Pazopanib + trametinib exhibited synergistic antitumor activity by inducing apoptosis and inhibiting ERK1/2 and Akt. In vivo antitumor activity was shown in osteosarcoma-bearing mice. The drug combination significantly down-modulated RTK Ephrin Type-A Receptor 2 (EphA2) and Interleukin-7 Receptor (IL-7R), whereas induced mitogen-activated protein-kinase kinase (MAPKK) MEK6. EphA2 silencing significantly reduced osteosarcoma cell proliferation and migration, while impeding MEK6 up-regulation in the treated cells significantly increased the antitumor effect of the studied drugs. Moreover, the up-regulation of MEK6 reduced combination activity. Pazopanib + trametinib demonstrated synergistic antitumor effects in osteosarcoma models through ERK and Akt inhibition and EphA2 and IL-7R down-modulation. MEK6 up-regulation might evoke escaping mechanism

Small Drugs, Huge Impact: The Extraordinary Impact of Antisense Oligonucleotides in Research and Drug Development

International audienceAntisense oligonucleotides (ASOs) are an increasingly represented class of drugs. These small sequences of nucleotides are designed to precisely target other oligonucleotides, usually RNA species, and are modified to protect them from degradation by nucleases. Their specificity is due to their sequence, so it is possible to target any RNA sequence that is already known. These molecules are very versatile and adaptable given that their sequence and chemistry can be custom manufactured. Based on the chemistry being used, their activity may significantly change and their effects on cell function and phenotypes can differ dramatically. While some will cause the target RNA to decay, others will only bind to the target and act as a steric blocker. Their incredible versatility is the key to manipulating several aspects of nucleic acid function as well as their process, and alter the transcriptome profile of a specific cell type or tissue. For example, they can be used to modify splicing or mask specific sites on a target. The entire design rather than just the sequence is essential to ensuring the specificity of the ASO to its target. Thus, it is vitally important to ensure that the complete process of drug design and testing is taken into account. ASOs’ adaptability is a considerable advantage, and over the past decades has allowed multiple new drugs to be approved. This, in turn, has had a significant and positive impact on patient lives. Given current challenges presented by the COVID-19 pandemic, it is necessary to find new therapeutic strategies that would complement the vaccination efforts being used across the globe. ASOs may be a very powerful tool that can be used to target the virus RNA and provide a therapeutic paradigm. The proof of the efficacy of ASOs as an anti-viral agent is long-standing, yet no molecule currently has FDA approval. The emergence and widespread use of RNA vaccines during this health crisis might provide an ideal opportunity to develop the first anti-viral ASOs on the market. In this review, we describe the story of ASOs, the different characteristics of their chemistry, and how their characteristics translate into research and as a clinical tool

Generation of size-controlled palladium(0) and gold(0) nanoclusters inside the nanoporous domains of gel-type functional resins: Part II: Prospects for oxidation catalysis in the liquid phase

Moderately cross-linked co-polymers of N,N-dimethylacrylamide (DMAA), 2-(methylthio)ethyl methacrylate (MTEMA)and N,N\u2032-methylenebisacrylamide proves to be effective macromolecular ligands able to extract, PdII and AuIII from water solutions and to thoroughly disperse them inside the relevant polymer frameworks. Chemical reduction with NaBH4 in water leads to M0/resin composites, in which size-control of the generated metal nanoclusters is achieved. Catalysts Au0/MTEMA-DMAA are active in the rapid oxidation of n-butanal to n-butanoic acid by dioxygen under mild conditions in water. Catalysts M0/MTEMA-DMAA and M 0/C (M = Au, Pd) are active and moderalely chemoselective in the oxidation of n-butanol to n-butanal under the same conditions. Activity and chemoselectivity are positively affected by the co-presence of the two metal centres and for M0 = Au and reach the best level when the very hydrophilic resin poly-(4-vinylpyridine-acrylic acid-N,N\u2032- methylenebisacrylamide) (VAM) is employed

Nanoclustered palladium(0) supported on a gel-type poly-acrylonitrile-N,N-dimethylacrylamide-ethylenedimethacrylate resin: Nanostructural aspects and catalytic behaviour

Gel-type resin poly-acrylonitrile (30 mol%)\u2013N,N-dimethylacrylamide (66 mol%)\u2013ethylenedimethacrylate (4 mol%) (ADE) is obtained in very high yield with -rays-sustained polymerisation in mass. Water-swollen ADE microparticles react readily with [PdCl4 2 12] in water to give a macromolecular complex likely to be . The material undergoes facile reduction to a Pd0/ADE nanocomposite, in which a surprisingly non-homogeneous distribution of Pd0 nanoclusters suggests a remarkable inhomogeneity in the distribution of the \u2013CN groups through the polymer framework. This circumstance is attributed to a marked occurrence of a block-type polymerisation of the acrylonitrile leading to spheroidal domains that are particularly rich in \u2013CN functionalities. Pd0/ADE appears to be an active, re50 usable, mechanically and chemically stable catalyst in the model hydrogenation reaction of cyclohexene in methanol under moderate conditions, carried out in batch reactors

Manganese(III) complexes with tetradentate O^C^C^O ligands: Synthesis, characterization and catalytic studies on the CO2 cycloaddition with epoxides

A novel class of manganese(III) complexes bearing bis(NHC)-bis(phenolate) (O^C^C^O) type ligands was successfully synthesized. Three differently substituted imidazolium salts (with 2-hydroxyphenyl, (H4L1)Br2, 5‑tert‑butyl‑2-hydroxyphenyl, (H4L2)Br2, and 3,5-di‑tert‑butyl‑2-hydroxyphenyl, (H4L3)Br2, groups) were prepared as precursors of the (O^C^C^O) ligands and a convenient high-yield complexation reaction using manganese(III) acetate was developed. Electrospray ionization mass spectrometry (ESI-MS) and single-crystal X-ray diffraction (SC-XRD) data confirm the formation of the complexes of general formula [MnBrL1–3] and clarify their coordination geometry. The complexes were studied as homogeneous catalysts in the cycloaddition of CO2 to benzyl glycidyl ether (BGE) to form the corresponding cyclic carbonate, using tetrabutylammonium bromide (TBAB) or bis(triphenylphosphine)iminium bromide (PPNBr) as co-catalysts. The complex [MnBrL3] shows the highest activity, and kinetic investigations revealed a pseudo-first order dependence with respect to BGE under neat conditions. The temperature effect was also investigated using the Eyring and Arrhenius equations and the activation parameters for the neat reaction using [MnBrL3] and TBAB were experimentally determined (ΔH‡ = 11.2 kcal·mol-1 and ΔS‡ = -50 cal·mol-1·K-1). On the basis of the performed mechanistic studies and DFT investigations, a catalytic cycle which involves the CO2 1,2-insertion as the rate determining step is proposed

Cross-linked polyvinyl polymers versus polyureas as designed supports for catalytically active M0 nanoclustersPart III. Nanometer scale structure of the cross-linked polyurea support EnCat 30 and of the PdII/EnCat 30 and Pd0/EnCat 30NP catalysts

The cross-linked polyurea support EnCat 30, its related macromolecular complex Pd(II)/EnCat 30 and its related Pd(0)/EnCat 30NP nanocomposite are thoroughly investigated with SEM, TEM, ISEC and ESR in the solid state (SEM and TEM) and swollen state in THF (ISEC and ESR). Pd(II)/EnCat 30 and its related Pd(0)/EnCat 30NP are obtained by microencapsulation of palladium acetate in a polyurea framework, which is formed upon hydrolysis/condensation of mixtures of multi-functional oligo-arylisocyanates in dichloroethane. Most remarkably, both Pd(II)/EnCat and Pd(0)/EnCat 30NP turn out to be far more (nano) porous and swellable materials than the blank polyurea matrix (EnCat 30). It is proposed that there is a strong nanostructural effect exerted by Pd(II) species due to its interaction with functional groups (amines stemming from the hydrolysis of the isocyanato groups or ureido groups belonging to the polymer chains) during the growth of the cross-linked polymer framework. As a consequence, the catalytic species in both Pd(II)/EnCat 30 and Pd(0)/EnCat 30NP are much more accessible to molecules diffusing from liquid phases in contact with the materials and, hence, are better catalysts than expected from the morphology of blank polyurea EnCat 30

Future, conditional and autonomous morphology in Occitan

Occitan presents a complex inflectional paradigm together with extensive regional variation, thus offering a rich source of morphological data; as the present study demonstrates, these data are of significant value both to morphological theory and to comparative Romance linguistics. The study is concerned with the form and meaning of two categories within the Occitan verb paradigm, the ‘synthetic future’ (SF) and ‘synthetic conditional’ (SC) derived from the Latin periphrastic constructions CANTARE HABEO and CANTARE HABEBAM respectively. In Romance languages which present this type of future and conditional, SF and SC typically share a stem: due to their parallel origin, it is often assumed that this identity of stem is unremarkable, and that it diagrams a common semantic value, usually that of temporal futurity. However, careful examination of the Occitan data reveals that both these assumptions are overly simplistic. While the semantic values associated with SF and SC in varieties of Occitan certainly overlap to some extent, this functional commonality is not absolute, nor does the distribution of semantic values map exactly to the distribution of stems within the paradigm. Furthermore, while in the majority of cases SF and SC do share a stem, Occitan also presents a phenomenon which may be unique within Romance, that of ‘asymmetrical’ stem distribution, in which the stems of the SF and SC are distinct from one another. The distribution of stems between SF and SC in Occitan can only be adequately explained by appealing both to semantic motivations and to the purely formal motivations of autonomous morphology. The phenomena discussed here show that autonomous morphology can interact with extramorphological factors, and, as a consequence, that an autonomously morphological element may be present even in morphological phenomena which prima facie appear extramorphologically motivated.EThOS - Electronic Theses Online ServiceGBUnited Kingdo