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© The Author(s) 2021., [Background]: Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer, requiring novel treatments to target both cancer cells and cancer stem cells (CSCs). Altered splicing is emerging as both a novel cancer hallmark and an attractive therapeutic target. The core splicing factor SF3B1 is heavily altered in cancer and can be inhibited by Pladienolide-B, but its actionability in PDAC is unknown. We explored the presence and role of SF3B1 in PDAC and interrogated its potential as an actionable target. [Methods]: SF3B1 was analyzed in PDAC tissues, an RNA-seq dataset, and publicly available databases, examining associations with splicing alterations and key features/genes. Functional assays in PDAC cell lines and PDX-derived CSCs served to test Pladienolide-B treatment effects in vitro, and in vivo in zebrafish and mice. [Results]: SF3B1 was overexpressed in human PDAC and associated with tumor grade and lymph-node involvement. SF3B1 levels closely associated with distinct splicing event profiles and expression of key PDAC players (KRAS, TP53). In PDAC cells, Pladienolide-B increased apoptosis and decreased multiple tumor-related features, including cell proliferation, migration, and colony/sphere formation, altering AKT and JNK signaling, and favoring proapoptotic splicing variants (BCL-XS/BCL-XL, KRASa/KRAS, Δ133TP53/TP53). Importantly, Pladienolide-B similarly impaired CSCs, reducing their stemness capacity and increasing their sensitivity to chemotherapy. Pladienolide-B also reduced PDAC/CSCs xenograft tumor growth in vivo in zebrafish and in mice. [Conclusion]. SF3B1 overexpression represents a therapeutic vulnerability in PDAC, as altered splicing can be targeted with Pladienolide-B both in cancer cells and CSCs, paving the way for novel therapies for this lethal cancer., This work has been supported by Spanish Ministry of Economy [MINECO; BFU2016–80360-R (to JPC)] and Ministry of Science and Innovation [MICINN; PID2019-105201RB-I00 (to JPC), PID2019-105564RB-I00 (to RML)]. Instituto de Salud Carlos III, co-funded by European Union (ERDF/ESF, “Investing in your future”) [FIS Grants PI17/02287 and PI20/01301 (to MDG), PI18/00757 (to BS,Jr); DTS Grant DTS20/00050 (to RML)); Postdoctoral Grant Sara Borrell CD19/00255 (to AIC); Predoctoral contract FI17/00282 (to EAP)]. Coordinated grant (GC16173694BARB) from the Fundación Asociación Española Contra el Cáncer (AECC) (to BS,Jr). Spanish Ministry of Universities [Predoctoral contracts FPU14/04290 (to SPA); FPU16/06190 (to VHA); FPU18/02275 (to RBE)]. Boehringer Ingelheim Fonds travel grant (EAP). Junta de Andalucía (BIO0139). GETNE2016 and GETNE2019 Research grants (to JPC); and CIBERobn. Associazione Italiana Ricerca Cancro (AIRC 5×1000 n. 12182); Fondazione Italiana Malattie Pancreas – Ministero Salute [FIMPCUP_J38D19000690001]; Fondazione Cariverona: Oncology Biobank Project “Antonio Schiavi” (prot.203885/2017).

(IF : 4,214); International audience; The most common mutation of the cystic fibrosis (CF) gene, the deletion of Phe508, encodes a protein (DeltaF508-CFTR) that fails to fold properly, thus mutated DeltaF508-cystic fibrosis transmembrane conductance regulator (CFTR) is recognized and degraded via the ubiquitin-proteasome endoplasmic reticulum-associated degradation pathway. Chemical and pharmacological chaperones and ligand-induced transport open options for designing specific drugs to control protein (mis)folding or transport. A class of compounds that has been proposed as having potential utility in DeltaF508-CFTR is that which targets the molecular chaperone and proteasome systems. In this study, we have selected deoxyspergualin (DSG) as a reference molecule for this class of compounds and for ease of cross-linking to human serum albumin (HSA) as a protein transporter. Chemical cross-linking of DSG to HSA via a disulfide-based cross-linker and its administration to cells carrying DeltaF508-CFTR resulted in a greater enhancement of DeltaF508-CFTR function than when free DSG was used. Function of the selenium-dependent oxidoreductase system was required to allow intracellular activation of HSA-DSG conjugates. The principle that carrier proteins can deliver pharmacological chaperones to cells leading to correction of defective CFTR functions is therefore proven and warrants further investigations.

Wnt/&beta, catenin signaling has been reported in Acute Myeloid leukemia, but little is known about its significance as a prognostic biomarker and drug target. In this study, we first evaluated the correlation between expression levels of Wnt molecules and clinical outcome. Then, we studied&mdash, in vitro and in vivo&mdash, the anti-leukemic value of combinatorial treatment between Wnt inhibitors and classic anti-leukemia drugs. Higher levels of &beta, catenin, Ser675-phospho-&beta, catenin and GSK-3&alpha, (total and Ser 9) were found in AML cells from intermediate or poor risk patients, nevertheless, patients presenting high activity of Wnt/&beta, catenin displayed shorter progression-free survival (PFS) according to univariate analysis. In vitro, many pharmacological inhibitors of Wnt signalling, i.e., LRP6 (Niclosamide), GSK-3 (LiCl, AR-A014418), and TCF/LEF (PNU-74654) but not Porcupine (IWP-2), significantly reduced proliferation and improved the drug sensitivity of AML cells cultured alone or in the presence of bone marrow stromal cells. In vivo, PNU-74654, Niclosamide and LiCl administration significantly reduced the bone marrow leukemic burden acting synergistically with Ara-C, thus improving mouse survival. Overall, our study demonstrates the antileukemic role of Wnt/&beta, catenin inhibition that may represent a potential new therapeutics strategy in AML.

International audience; In this study, we compared the overall gene and pathway expression profiles of HS-5 and HS-27A stromal cell lines with those of primary bone marrow MSCs to verify if they can be considered a reliable alternative tool for evaluating the contribution of MSCs in tumor development and immunomodulation. Indeed, due to their easier manipulation in vitro as compared to primary MSC cultures, several published studies took advantage of stromal cell lines to assess the biological mechanisms mediated by stromal cells in influencing tumor biology and immune responses. However, the process carried out to obtain immortalized cell lines could profoundly alter gene expression profile, and consequently their biological characteristics, leading to debatable results. Here, we evaluated the still undisclosed similarities and differences between HS-5, HS-27A cell lines and primary bone marrow MSCs in the context of tumor development and immunomodulation. Furthermore, we assessed by standardized immunological assays the capability of the cell lines to reproduce the general mechanisms of MSC immunoregulation. We found that only HS-5 cell line could be suitable to reproduce not only the MSC capacity to influence tumor biology, but also to evaluate the molecular mechanisms underlying tumor immune escape mediated by stroma cells. However, HS-5 pre-treatment with inflammatory cytokines, that normally enhances the immunosuppressive activity of primary MSCs, did not reproduce the same MSCs behavior, highlighting the necessity to accurately set up in vitro assays when HS-5 cell line is used instead of its primary counterpart.

Carbon‐based nanomaterials (CNMs) are being explored for neurological applications. However, systematic in vivo studies investigating the effects of CNM nanocarriers in the brain and how brain cells respond to such nanomaterials are scarce. To address this, functionalized multiwalled carbon nanotubes and graphene oxide (GO) sheets are injected in mice brain and compared with charged liposomes. The induction of acute neuroinflammatory and neurotoxic effects locally and in brain structures distant from the injection site are assessed up to 1 week postadministration. While significant neuronal cell loss and sustained microglial cell activation are observed after injection of cationic liposomes, none of the tested CNMs induces either neurodegeneration or microglial activation. Among the candidate nanocarriers tested, GO sheets appear to elicit the least deleterious neuroinflammatory profile. At molecular level, GO induces moderate activation of proinflammatory markers compared to vehicle control. At histological level, brain response to GO is lower than after vehicle control injection, suggesting some capacity for GO to reduce the impact of stereotactic injection on brain. While these findings are encouraging and valuable in the selection and design of nanomaterial‐based brain delivery systems, they warrant further investigations to better understand the mechanisms underlying GO immunomodulatory properties in brain., This work was partly supported by the EU H2020 RTD Framework Program: FET Graphene Flagship project (GrapheneCore3, Grant agreement ID: 881603), the Centre National de la Recherche Scientifique (CNRS), the International Center for Frontier Research in Chemistry (icFRC), and the Agence Nationale de la Recherche (ANR) through the LabEx project Chemistry of Complex Systems (ANR‐10‐LABX‐0026_CSC). M.P., as the recipient of the AXA Carbon Bionanotechnology Chair, is grateful to the AXA Research Fund for financial support. MP was also supported by the Spanish Ministry of Economy and Competitiveness MINECO (project CTQ2016‐76721‐R), the University of Trieste, and the Spanish State Research Agency (Maria de Maeztu Units of Excellence Program Grant No. MDM‐2017‐0720). Financial support to this project was partially provided by the Fondazione Cariverona (“Verona Nanomedicine Initiative”) and funding from an intramural (University of Verona) international cooperation program (“CooperInt”) was obtained. K.K. would like to acknowledge the Severo Ochoa Centre of Excellence Award to ICN2.

[Aim]: To study the efficiency of multifunctional polymer-based superparamagnetic iron oxide nanoparticles (bioferrofluids) as a T2 magnetic resonance contrast agent and their uptake and toxicity in liver. [Materials & methods]: Mice were intravenously injected with bioferrofluids and Endorem®. The magnetic resonance efficiency, uptake and in vivo toxicity were investigated by means of magnetic resonance imaging (MRI) and histological techniques. [Results]: Bioferrofluids are a good T2 contrast agent with a higher r2/r1 ratio than Endorem. Bioferrofluids have a shorter blood circulation time and persist in liver for longer time period compared with Endorem. Both bioferrofluids and Endorem do not generate any noticeable histological lesions in liver over a period of 60 days post-injection. [Conclusion]: Our bioferrofluids are powerful diagnostic tool without any observed toxicity over a period of 60 days post-injection., Financial support from the Spanish Ministry of Science and Innovation research grant MAT2014-54975-R, and from the Programa Operativo FEDER Aragon 2014-2020 ‘Construyendo Europa desde Aragon’, is gratefully acknowledged. Additional support from the Diputacion General de Aragon (DGA-M4) is also acknowledged. LMA Ali acknowledges financial support from the Spanish Ministry of Science and Innovation FPI research grants. The Servicio de Experimentacion Animal (SAI), and servicio de Microscopia Electronica de Materiales of Zaragoza University. P Marzola acknowledges financial support from Fondazione Cariverona (Verona,Italy) through the project ‘Verona Nanomedicine Initiative’ and from MIUR through FIRB project RBAP114AMK – RI.NA.ME. ‘Rete Integrata per la Nanomedicina’.

Medicago truncatula is one of the most studied model plants. Nevertheless, the genome of this legume remains incompletely determined. We used RNA-Seq to characterize the transcriptome during the early organogenesis of the nodule and during its functioning. We detected 37,333 expressed transcription units; to our knowledge, 1,670 had never been described before and were functionally annotated. We identified 7,595 new transcribed regions, mostly corresponding to 5′ and 3′ untranslated region extensions and new exons associated with 5,264 previously annotated genes. We also inferred 23,165 putative transcript isoforms from 6,587 genes and measured the abundance of transcripts for each isoform, which suggests an important role for alternative splicing in the generation of proteome diversity in M. truncatula. Finally, we carried out a differential expression analysis, which provided a comprehensive view of transcriptional reprogramming during nodulation. In particular, depletion of nitric oxide in roots inoculated with Sinorhizobium meliloti greatly increased our understanding of the role of this reactive species in the optimal establishment of the symbiotic interaction, revealing differential patterns of expression for 2,030 genes and pointing to the inhibition of the expression of defense genes.