Endogenous extracellular matrix regulates the response of osteosarcoma 3D spheroids to doxorubicin

The extracellular matrix (ECM) modulates cell behavior, shape, and viability as well as mechanical properties. In recent years, ECM disregulation and aberrant remodeling has gained considerable attention in cancer targeting and prevention since it may stimulate tumorigenesis and metastasis. Here, we developed an in vitro model that aims at mimicking the in vivo tumor microenvironment by recapitulating the interactions between osteosarcoma (OS) cells and ECM with respect to cancer progression. We long-term cultured 3D OS spheroids made of metastatic or non-metastatic OS cells mixed with mesenchymal stromal cells (MSCs); confirmed the deposition of ECM proteins such as Type I collagen, Type III collagen, and fibronectin by the stromal component at the interface between tumor cells and MSCs; and found that ECM secretion is inhibited by a neutralizing anti-IL-6 antibody, suggesting a new role of this cytokine in OS ECM deposition. Most importantly, we showed that the cytotoxic effect of doxorubicin is reduced by the presence of Type I collagen. We thus conclude that ECM protein deposition is crucial for modelling and studying drug response. Our results also suggest that targeting ECM proteins might improve the outcome of a subset of chemoresistant tumors

Antiviral therapies against Ebola and other emerging viral diseases using existing medicines that block virus entry

Emerging viral diseases pose a threat to the global population as intervention strategies are mainly limited to basic containment due to the lack of efficacious and approved vaccines and antiviral drugs. The former was the only available intervention when the current unprecedented Ebolavirus (EBOV) outbreak in West Africa began. Prior to this, the development of EBOV vaccines and anti-viral therapies required time and resources that were not available. Therefore, focus has turned to re-purposing of existing, licenced medicines that may limit the morbidity and mortality rates of EBOV and could be used immediately. Here we test three such medicines and measure their ability to inhibit pseudotype viruses (PVs) of two EBOV species, Marburg virus (MARV) and avian influenza H5 (FLU-H5). We confirm the ability of chloroquine (CQ) to inhibit viral entry in a pH specific manner. The commonly used proton pump inhibitors, Omeprazole and Esomeprazole were also able to inhibit entry of all PVs tested but at higher drug concentrations than may be achieved in vivo. We propose CQ as a priority candidate to consider for treatment of EBOV

Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

Minimal information for studies of extracellular vesicles 2018 (MISEV2018): a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

Spheroid-based 3D cell cultures identify salinomycin as a promising drug for the treatment of chondrosarcoma

Chondrosarcoma (CS) is a cartilage malignancy of adulthood that is treated by surgery alone, since chemotherapy is considered ineffective. Unfortunately, a large proportion of patients with CS develop lung metastases, and several die of the disease. In this study, we compared 3D-spheroid cultures and conventional cell monolayer models in order to identify the best way to select anticancer agents that could be effective for the systemic control of CS. Using SW1353 cells, we developed a three-dimensional (3D) in vitro culture model to mimic in vivo features of CS microenvironment and evaluated the efficacy of different drugs to modulate CS cell proliferation and survival in 2D versus 3D-cultures. Doxorubicin (DXR) and cisplatin, that are widely employed in sarcomas, were less effective on 3D-CS spheroids when compared to standard monolayer models, whereas treatment with the ionophore salinomycin (SAL) had a strong cytotoxic effect both on 2D and 3D-cultures. Furthermore, as demonstrated by the reduced viability and the enhanced DXR nuclear localization, SAL enhanced DXR cytotoxicity in 3D-CS spheroids also at sub-lethal doses. SAL activity on 3D-CS spheroids was mediated by a significant induction of apoptosis via caspase activation. This study demonstrates that preclinical tests significantly differ in monolayer and 3D cultures of CS cells. Using this approach, SAL, alone or, at sub-lethal concentrations, in combination with DXR, represents a promising agent for the systemic treatment of CS. \ua9 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res

Flexible polymeric ultrathin film for mesenchymal stem cell differentiation

Ultrathin films (also called nanofilms) are two-dimensional (2-D) polymeric structures with potential application in biology, biotechnology, cosmetics and tissue engineering. Since they can be handled in liquid form with micropipettes or tweezers they have been proposed as flexible systems for cell adhesion and proliferation. In particular, with the aim of designing a novel patch for bone or tendon repair and healing, in this work the biocompatibility, adhesion and proliferation activity of Saos-2, MRC-5 and human and rat mesenchymal stem cells on poly(lactic acid) nanofilms were evaluated. The nanofilms did not impair the growth and differentiation of osteoblasts and chondrocytes. Moreover, nanofilm adhesion to rabbit joints was evident under ex vivo conditions