FGF23 Expression Is a Promising Immunohistochemical Diagnostic Marker for Undifferentiated Pleomorphic Sarcoma of Bone (UPSb).

Background: Undifferentiated pleomorphic sarcoma of bone (UPSb) is a rare primary bone sarcoma that lacks a specific line of differentiation. Distinguishing between UPSb and other malignant bone sarcomas, including dedifferentiated chondrosarcoma and osteosarcoma, is challenging due to their overlapping features. We have previously identified that UPSb tumours have elevated mRNA levels of Fibroblast Growth Factor 23 (FGF23) transcripts compared to other sarcomas including osteosarcoma. In the present study, we evaluated the specificity and practicality of FGF23 immunoreactivity as a specific diagnostic tool to differentiate UPSb tumours from osteosarcomas and dedifferentiated chondrosarcomas. Methods: A total of 10 UPSb, 10 osteosarcoma, and 10 dedifferentiated chondrosarcoma cases (all high-grade), were retrieved and immunohistochemistry for FGF23 was performed. Results: FGF23 protein was expressed at high levels in 80-90% of undifferentiated pleomorphic sarcoma of the bone cases, whereas it was expressed at significantly lower levels in dedifferentiated chondrosarcoma and osteosarcoma cases. A semiquantitative analysis, considering the intensity of immunoreactivity, confirmed significantly elevated FGF23 expression levels in UPSb tissues compared to those observed in osteosarcoma and dedifferentiated chondrosarcoma tissues. Conclusions: The results we present here suggest that FGF23 immunohistochemistry may be a useful tool to aid in differentiating UPSb from morphologically similar malignant bone sarcomas, especially in situations where sampling is restricted and there is limited clinical information available.

Cognitive dysfunction and impaired neuroplasticity following repeated exposure to the synthetic cannabinoid JWH-018 in male mice.

BACKGROUND AND PURPOSE: Psychotic disorders have been reported in long-term users of synthetic cannabinoids. This study aims at investigating the long-lasting effects of repeated JWH-018 exposure. EXPERIMENTAL APPROACH: Male CD-1 mice were injected with vehicle, JWH-018 (6 mg·kg-1 ), the CB1 -antagonist NESS-0327 (1 mg·kg-1 ) or co-administration of NESS-0327 and JWH-018, every day for 7 days. After 15 or 16 days washout, we investigated the effects of JWH-018 on motor function, memory, social dominance and prepulse inhibition (PPI). We also evaluated glutamate levels in dialysates from dorsal striatum, striatal dopamine content and striatal/hippocampal neuroplasticity focusing on the NMDA receptor complex and the neurotrophin BDNF. These measurements were accompanied by in vitro electrophysiological evaluations in hippocampal preparations. Finally, we investigated the density of CB1 receptors and levels of the endocannabinoid anandamide (AEA) and 2-arachidonoylglycerol (2-AG) and their main synthetic and degrading enzymes in the striatum and hippocampus. KEY RESULTS: The repeated treatment with JWH-018 induced psychomotor agitation while reducing social dominance, recognition memory and PPI in mice. JWH-018 disrupted hippocampal LTP and decreased BDNF expression, reduced the synaptic levels of NMDA receptor subunits and decreased the expression of PSD95. Repeated exposure to JWH-018, reduced hippocampal CB1 receptor density and induced a long-term alteration in AEA and 2-AG levels and their degrading enzymes, FAAH and MAGL, in the striatum. CONCLUSION AND IMPLICATIONS: Our findings suggest that repeated administration of a high dose of JWH-018 leads to the manifestation of psychotic-like symptoms accompanied by alterations in neuroplasticity and change in the endocannabinoid system.

Polythiophene-mediated light modulation of membrane potential and calcium signalling in human adipose-derived stem/stromal cells.

Recent progress in the fields of regenerative medicine and tissue engineering has been strongly fostered both by the investigation of crucial cues, able to trigger the regeneration of damaged tissues, and by the development of ad hoc functional materials, capable of selectively (re-)activating relevant physiological pathways. In parallel to the successful realization of biochemical cues and the optimization of delivery protocols, the use of biophysical stimuli has been emerging as an alternative, highly effective strategy. Techniques based on electrical, magnetic and mechanical stimulation have been reported to efficiently direct differentiation of stem cells and modulate cell physiology at different developmental stages. In this framework, the use of optical stimulation represents a valuable approach, possibly overcoming current limitations of chemical cues, like limited spatial and temporal resolution and poor control over the extracellular environment. Surprisingly, the effects of light on the physiological properties (light toxicity, cell membrane potential, and cell ionic trafficking) of undifferentiated cells, as well as on their differentiation pathways, were investigated to a very limited extent and rarely quantified in a systematic way. In this work, we aim at clarifying the effects of optical excitation on the physiological behaviour of undifferentiated human adipose-derived stem cells (hASC), cultured on top of a light-sensitive conjugated polymer, region-regular poly-3-hexyl-thiophene (P3HT). Interestingly, we observe statistically significant modulation of the cell membrane potential, as well as noticeable effects on intracellular calcium signalling, triggered by P3HT excitation upon green light stimuli. Possible mechanisms involved in the signal transduction pathways are considered and critically discussed. The capability to modulate the physiological response of hASC upon photoexcitation, in a highly controlled and selective manner, provides a promptly available and non invasive diagnostic tool, thus contributing to the understanding of the complex machinery behind stem cells and material interfaces. Moreover, it may open the route to novel techniques to drive the differentiation path with unprecedented versatility and operational easiness.

Lipidomics of Cell Secretome Combined with the Study of Selected Bioactive Lipids in an In Vitro Model of Osteoarthritis.

Analytical advancements in lipidomics have enabled large-scale investigations of lipid biology. Herein, we focused on four bioactive lipid families, namely polyunsaturated fatty acids, eicosanoids, endocannabinoids, and N-acylethanolamines, and their involvement in the mesenchymal stem cells (MSC)-related inflammatory scenario. Since MSC secretome may represent a valid therapeutic alternative, here, the complete secretome and its vesicular component from adipose- and bone marrow-derived MSC and dermal fibroblasts were characterized by targeted mass spectrometry lipidomics. The 2-arachidonoylglycerol (2AG) and the palmitoylethanolamide (PEA), previously quantified in the MSC's secretome, were further investigated by assessing hypothetical effects in an in vitro model of osteoarthritis (OA) based on human primary articular chondrocytes (CH) stimulated with tumor necrosis factor alpha (TNFα). TNFα enhances the release of the inflammatory lipid prostaglandin E2 (PGE2), and an additional increment was observed when CH were treated with both TNFα and 2AG. In contrast, PEA downmodulates the PGE2 release to the levels of unstimulated CH suggesting a protective effect. TNFα also increases the expression of cyclooxygenase 2 (COX2), in particular when combined with 2AG, while PEA partly blunts TNFα-induced COX2 expression. In addition, TNFα-stimulated CH produce significantly higher levels of the inflammatory mediator nitric oxide (NO) both in the presence and in the absence of 2AG, and PEA was able to partially reduce NO release. Our results show a first partial lipidomic profile of MSC and DF secretome and suggest a possible implication of bioactive lipids in the OA scenario and in the future use of these cell-free products as innovative therapeutics.

Secretome of human adipose-derived mesenchymal stem cell relieves pain and neuroinflammation independently of the route of administration in experimental osteoarthritis.

OBJECTIVE: Treatment of pain associated with osteoarthritis (OA) is unsatisfactory and innovative approaches are needed. The secretome from human adipose-derived mesenchymal stem cells (hASC-Conditioned Medium, CM) has been successfully used to relieve painful symptoms in models of chronic pain. The aim of this study was to explore the efficacy of the hASC-CM to control pain and neuroinflammation in an animal model of OA. METHODS: OA was induced in mice by intra-articular monosodium-iodoacetate (MIA) injection. Thermal hyperalgesia and mechanical allodynia were assessed. Once hypersensitivity was established (7 days after MIA), hASC-CM was injected by IA, IPL and IV route and its effect monitored over time. Neuroinflammation in nerve, dorsal root ganglia and spinal cord was evaluated measuring proinflammatory markers and mediators by RT-qPCR. Protein content analysis of secretome by Mass Spectrometry was performed. RESULTS: A single injection with hASC-CM induced a fast and long lasting antihyperalgesic and antiallodynic effect. The IV route of administration appeared to be the most efficacious although all the treatments were effective. The effect on pain correlated with the ability of hASC-CM to reduce the neuroinflammatory condition in both the peripheral and central nervous system. Furthermore, the secretome analysis revealed 101 factors associated with immune regulation. CONCLUSION: We suggest that hASC-CM is a valid treatment option for controlling OA-related hypersensitivity, exerting a rapid and long lasting pain relief. The mechanisms underpinning its effects are likely linked to the positive modulation of neuroinflammation in peripheral and central nervous system that sustains peripheral and central sensitization.

Bioactive Lipids in MSCs Biology: State of the Art and Role in Inflammation.

Lipidomics is a lipid-targeted metabolomics approach that aims to the comprehensive analysis of lipids in biological systems in order to highlight the specific functions of lipid species in health and disease. Lipids play pivotal roles as they are major structural components of the cellular membranes and energy storage molecules but also, as most recently shown, they act as functional and regulatory components of intra- and intercellular signaling. Herein, emphasis is given to the recently highlighted roles of specific bioactive lipids species, as polyunsaturated fatty acids (PUFA)-derived mediators (generally known as eicosanoids), endocannabinoids (eCBs), and lysophospholipids (LPLs), and their involvement in the mesenchymal stem cells (MSCs)-related inflammatory scenario. Indeed, MSCs are a heterogenous population of multipotent cells that have attracted much attention for their potential in regulating inflammation, immunomodulatory capabilities, and reparative roles. The lipidomics of the inflammatory disease osteoarthritis (OA) and the influence of MSCs-derived lipids have also been addressed.

Endogenous 1-H-Pyrrole-2,3,5-Tricarboxylic Acid (PTCA) in Hair and Its Forensic Applications: A Pilot Study on a Wide Multi-Ethnic Population.

Over the years, several studies have shown that many factors are likely to affect the results of forensic hair analyses and complicate their interpretation. Among these factors, one of the major drawbacks in hair analysis is the affectability of deposited xenobiotics by cosmetic treatments, which could be eventually used to adulterate the sample. It is well known that some cosmetic treatments containing hydrogen peroxide, such as permanent dyeing or bleaching, lead to the formation of 1-H-pyrrole-2,3,5-tricarboxylic acid (PTCA), a melanin degradation product. Considering that PTCA is also an endogenous compound, spontaneously formed by natural oxidation of melanin, its only detection in hair is not enough to confirm a cosmetic oxidative treatment. For this reason, the aim of the present work was to develop and validate a reliable liquid-liquid extraction method in ultra-high-performance liquid chromatographic-tandem mass spectrometry for the determination of endogenous PTCA in hair from a wide multi-ethnic population (African, Arab, Asian-Pacific, Caucasian, Hispanic and Indian). According to previous studies, untreated hair samples showed a PTCA content of 8.54 ± 5.72 ng/mg (mean ± standard deviation [SD]), ranging between 0.44 and 23.7 ng/mg; after in vitro cosmetic bleaching, PTCA increased to 16.8 ± 6.95 ng/mg (range: 4.16-32.3 ng/mg). Comparing baseline PTCA levels of each subgroup with the others, we could not observe any statistically significant difference, except for Caucasians (P < 0.05), wherein the concentrations were lower. Further studies and a wider sampling are necessary to elucidate the role of PTCA as diagnostic marker of cosmetic hair treatment in forensic field.

Quantitative Lipidomic Analysis of Osteosarcoma Cell-Derived Products by UHPLC-MS/MS.

Changes in lipid metabolism are involved in several pathological conditions, such as cancer. Among lipids, eicosanoids are potent inflammatory mediators, synthesized from polyunsaturated fatty acids (PUFAs), which coexist with other lipid-derived ones, including endocannabinoids (ECs) and N-acylethanolamides (NAEs). In this work, a bioanalytical assay for 12 PUFAs/eicosanoids and 20 ECs/NAEs in cell culture medium and human biofluids was validated over a linear range of 0.1-2.5 ng/mL. A fast pretreatment method consisting of protein precipitation with acetonitrile followed by a double step liquid-liquid extraction was developed. The final extracts were injected onto a Kinetex ultra-high-performance liquid chromatography (UHPLC) XB-C18 column with a gradient elution of 0.1% formic acid in water and methanol/acetonitrile (5:1; v/v) mobile phase. Chromatographic separation was followed by detection with a triple-quadrupole mass spectrometer operating both in positive and negative ion-mode. A full validation was carried out in a small amount of cell culture medium and then applied to osteosarcoma cell-derived products. To the best of our knowledge, this is the first lipid profiling of bone tumor cell lines (SaOS-2 and MG-63) and their secretome. Our method was also partially validated in other biological matrices, such as serum and urine, ensuring its broad applicability as a powerful tool for lipidomic translational research.

Comprehensive Molecular Characterization of Adamantinoma and OFD-like Adamantinoma Bone Tumors.

Adamantinoma and osteofibrous dysplasia (OFD)-like adamantinoma are rare primary bone tumors that are predominantly confined to the tibia. These 2 entities show similarities in location, histology, and radiologic appearance; however, adamantinoma is malignant and therefore differentiating between these bone tumors is essential for optimal patient care. To elucidate their genomic and transcriptomic alteration profiles and expand their etiological mechanisms, whole exome sequencing (WES) and RNA sequencing (RNA-Seq) were conducted on adamantinoma and OFD-like adamantinoma tumors. Copy number variation analysis using WES data revealed distinct chromosomal alteration profiles for adamantinoma tumors compared with OFD-like adamantinomas, allowing molecular differentiation between the 2 tumor subtypes. Combining WES and copy number variation analyses, the chromatin remodelling-related gene KMT2D was recurrently altered in 3/8 adamantinoma tumors (38%), highlighting the potential involvement of deregulated chromatin structure and integrity in adamantinoma tumorigenesis. RNA-Seq analysis revealed a novel somatic gene fusion (EPHB4-MARCH10) in an adamantinoma, the gene fusion was fully characterized. Hierarchical clustering analysis of RNA-Seq data distinctly clustered adamantinoma tumors from OFD-like adamantinomas, allowing to molecularly distinguish between the 2 entities. David Gene Ontology analysis of differentially expressed genes identified distinct altered pathways in adamantinoma and OFD-like adamantinoma tumors, highlighting the different histopathologic characteristics of these bone tumor subtypes. Moreover, RNA-Seq expression profiling analysis identified elevated expression of DLK1 gene in adamantinomas, serving as a potential molecular biomarker. The present study revealed novel genetic and transcriptomic insights for adamantinoma and OFD-like adamantinoma tumors, allowing to differentiate genetically and transcriptomically between the 2 lesions and identifying a potential diagnostic marker for adamantinomas.

Human Olfactory Bulb Neural Stem Cells (Hu-OBNSCs) Can Be Loaded with Paclitaxel and Used to Inhibit Glioblastoma Cell Growth.

Exploitation of the potential ability of human olfactory bulb (hOB) cells to carry, release, and deliver an effective, targeted anticancer therapy within the central nervous system (CNS) milieu remains elusive. Previous studies have demonstrated the marked ability of several types of stem cells (such as mesenchymal stem cells (MSCs) to carry and release different anti-cancer agents such as paclitaxel (PTX). Herein we investigate the ability of human olfactory bulb neural stem cells (Hu-OBNSCs) to carry and release paclitaxel, producing effective cytotoxic effects against cancer cells. We isolated Hu-OBNSCs from the hOB, uploaded them with PTX, and studied their potential cytotoxic effects against cancer cells in vitro. Interestingly, the Hu-OBNSCs displayed a five-fold increase in their resistance to the cytotoxicity of PTX, and the PTX-uploaded Hu-OBNSCs were able to inhibit proliferation and invasion, and to trigger marked cytotoxic effects on glioblastoma multiforme (GBM) cancer cells, and Human Caucasian fetal pancreatic adenocarcinoma 1 (CFPAC-1) in vitro. Despite their ability to resist the cytotoxic activity of PTX, the mechanism by which Hu-OBNSCs acquire resistance to PTX is not yet explained. Collectively our data indicate the ability of the Hu-OBNSCs to resist PTX, and to trigger effective cytotoxic effects against GBM cancer cells and CFPAC-1. This indicates their potential to be used as a carrier/vehicle for targeted anti-cancer therapy within the CNS.

Genomic and transcriptomic characterisation of undifferentiated pleomorphic sarcoma of bone.

Undifferentiated pleomorphic sarcoma of bone (UPSb) is a rare primary bone sarcoma that lacks a specific line of differentiation. There is very little information about the genetic alterations leading to tumourigenesis or malignant transformation. Distinguishing between UPSb and other malignant bone sarcomas, including dedifferentiated chondrosarcoma and osteosarcoma, can be challenging due to overlapping features. To explore the genomic and transcriptomic landscape of UPSb tumours, whole-exome sequencing (WES) and RNA sequencing (RNA-Seq) were performed on UPSb tumours. All tumours lacked hotspot mutations in IDH1/2 132 or 172 codons, thereby excluding the diagnosis of dedifferentiated chondrosarcoma. Recurrent somatic mutations in TP53 were identified in four of 14 samples (29%). Moreover, recurrent mutations in histone chromatin remodelling genes, including H3F3A, ATRX and DOT1L, were identified in five of 14 samples (36%), highlighting the potential role of deregulated chromatin remodelling pathways in UPSb tumourigenesis. The majority of recurrent mutations in chromatin remodelling genes identified here are reported in COSMIC, including the H3F3A G34 and K36 hotspot residues. Copy number alteration analysis identified gains and losses in genes that have been previously altered in UPSb or UPS of soft tissue. Eight somatic gene fusions were identified by RNA-Seq, two of which, CLTC-VMP1 and FARP1-STK24, were reported previously in multiple cancers. Five gene fusions were genomically characterised. Hierarchical clustering analysis, using RNA-Seq data, distinctly clustered UPSb tumours from osteosarcoma and other sarcomas, thus molecularly distinguishing UPSb from other sarcomas. RNA-Seq expression profiling analysis and quantitative reverse transcription-polymerase chain reaction showed an elevated expression in FGF23, which can be a potential molecular biomarker for UPSb. To our knowledge, this study represents the first comprehensive WES and RNA-Seq analysis of UPSb tumours revealing novel protein-coding recurrent gene mutations, gene fusions and identifying a potential UPSb molecular biomarker, thereby broadening the understanding of the pathogenic mechanisms and highlighting the possibility of developing novel targeted therapeutics. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Genetic analyses of undifferentiated small round cell sarcoma identifies a novel sarcoma subtype with a recurrent CRTC1-SS18 gene fusion.

In recent years, undifferentiated small round cell sarcomas (USRCSs) have been divided into a variety of new, rare, sarcoma subtypes, including the group of Ewing-like sarcomas, which have the morphological appearance of Ewing sarcomas, but carry CIC-DUX4, BCOR-CCNB3 and other gene fusions different from the classic EWSR1-ETS gene fusion. Using high-throughput RNA-sequencing (RNA-seq) analyses, we identified a novel recurrent gene fusion, CRTC1-SS18, in two cases of USRCS that lacked any known translocation. RNA-seq results were confirmed by reverse transcription polymerase chain reaction, long-range polymerase chain reaction, and fluorescence in situ hybridization. In vitro, we showed that the cells expressing the gene fusion were morphologically distinct and had enhanced oncogenic potential as compared with control cells. Expression profile comparisons with tumours of other sarcoma subtypes demonstrated that both cases clustered close to EWSR1-CREB1-positive tumours. Moreover, these analyses indicated enhanced NTRK1 expression in CRTC1-SS18-positive tumours. We conclude that the novel gene fusion identified in this study adds a new subtype to the USRCSs with unique gene signatures, and may be of therapeutic relevance. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Therapeutic effect of human adipose-derived stem cells and their secretome in experimental diabetic pain.

Painful neuropathy is one of the complications of diabetes mellitus that adversely affects patients'quality of life. Pharmacological treatments are not fully satisfactory, and novel approaches needed. In a preclinical mouse model of diabetes the effect of both human mesenchymal stromal cells from adipose tissue (hASC) and their conditioned medium (hASC-CM) was evaluated. Diabetes was induced by streptozotocin. After neuropathic hypersensitivity was established, mice were intravenously injected with either 1 × 106 hASC or with CM derived from 2 × 106 hASC. Both hASC and CM (secretome) reversed mechanical, thermal allodynia and thermal hyperalgesia, with a rapid and long lasting effect, maintained up to 12 weeks after treatments. In nerves, dorsal root ganglia and spinal cord of neuropathic mice we determined high IL-1ß, IL-6 and TNF-α and low IL-10 levels. Both treatments restored a correct pro/antinflammatory cytokine balance and prevented skin innervation loss. In spleens of streptozotocin-mice, both hASC and hASC-CM re-established Th1/Th2 balance that was shifted to Th1 during diabetes. Blood glucose levels were unaffected although diabetic animals regained weight, and kidney morphology was recovered by treatments. Our data show that hASC and hASC-CM treatments may be promising approaches for diabetic neuropathic pain, and suggest that cell effect is likely mediated by their secretome.

Diagnostic utility of IDH1/2 mutations to distinguish dedifferentiated chondrosarcoma from undifferentiated pleomorphic sarcoma of bone.

Histologically, it is nearly impossible to distinguish the dedifferentiated component of dedifferentiated chondrosarcoma from undifferentiated pleomorphic sarcoma (UPS) of bone when the low-grade cartilaginous component is absent. Previous studies have revealed that isocitrate dehydrogenase 1 (IDH1) and IDH2 mutations are present in a significant number of cartilaginous tumors including most conventional chondrosarcomas and dedifferentiated chondrosarcomas. These mutations have not been studied in UPSs of bone. We sought to investigate whether an IDH1 or IDH2 mutation signature could be used as a clinically diagnostic marker for the distinction of dedifferentiated component of chondrosarcoma from UPS of bone. Sixty-eight bone tumor cases, including 31 conventional chondrosarcomas, 23 dedifferentiated chondrosarcomas, and 14 UPSs of bone, were collected for IDH1/2 mutation analysis either using the Qiagen IDH1/2 RGQ PCR Kit or using whole-exome sequencing. IDH1/2 mutations were detected in 87% (20/23) of dedifferentiated chondrosarcomas and 30% (6/20) of conventional chondrosarcomas. No mutations were detected in the IDH1/2 codon 132 or codon 172 among 14 UPSs of bone. Identification of IDH1 or IDH2 mutations supports the diagnosis of dedifferentiated chondrosarcoma rather than UPS of bone while also providing some insight into the pathogenesis of these 2 lesions.

Fluorescent Immortalized Human Adipose Derived Stromal Cells (hASCs-TS/GFP+) for Studying Cell Drug Delivery Mediated by Microvesicles.

BACKGROUND: A new tool for the drug delivery is based on the use of Mesenchymal Stromal Cells (MSCs) loaded in vitro with anti-cancer drugs. Unfortunately, the restricted lifespan of MSCs represents a significant limitation to produce them in high amounts and for long time studies. Immortalized MSCs from adipose tissue (hASCs) have been generated as good source of cells with stable features. These cells could improve the development of standardized procedures for both in vitro and preclinical studies. Furthermore they facilitate procedures for preparing large amounts of secretome containing microvesicles (MVs). METHOD: We used human adipose tissue derived MSCs immortalized with hTERT+SV40 (TS) genes and transfected with GFP (hASCs-TS/GFP+). This line was investigated for its ability to uptake and release anticancer drugs. Microvesicles associated to paclitaxel (MVs/PTX) were isolated, quantified, and tested on pancreatic cancer cells. RESULTS: The line hASCs-TS/GFP+ maintained the main mesenchymal characters and was able to uptake and release, in active form, both paclitaxel and gemcitabine. From paclitaxel loaded hASCs-TS/GFP+ cells were isolated microvesicles in sufficient amount to inhibit "in vitro" the proliferation of pancreatic tumor cells. CONCLUSION: Our study suggests that human immortalized MSCs could be used for a large scale production of cells for mediated drug delivery. Moreover, the secretion of drug-associated MVs could represent a new way for producing new drug formulation by "biogenesis". In the context of the "advanced cell therapy procedure", the MVs/PTX production would use less resource and time and it could possibly contribute to simplification of GMP procedures.

Paclitaxel-releasing mesenchymal stromal cells inhibit in vitro proliferation of human mesothelioma cells.

INTRODUCTION: Malignant pleural mesothelioma (MPM) is a rare fatal asbestos-related malignancy originating in the mesothelial cells of the pleura. A platinum-based doublet containing a third-generation antifolate is the front-line standard of care whilst there are no approved second-line treatments for MPM which remains a disease setting to test the efficacy of new therapeutic agents. METHODS: Bone marrow mesenchymal stromal cells (BM-MSCs) were loaded with pemetrexed (PMX) and paclitaxel (PTX) according to a standardized procedure. Drug release by both PMX- and PTX-primed BM-MSCs (BM-MSCs/PMX and BM-MSCs/PTX) was tested on the in vitro proliferation of a panel of tumor cell lines including NCI-H28 mesothelioma. RESULTS: The in vitro anticancer activity of pure PTX was significantly higher than that of PMX against all the cell lines tested (14.7 times higher than that of PMX against NCI-H28). Whereas BM-MSCs did not take up and release PMX in amounts effective on mesothelioma, PTX-loaded BM-MSCs dramatically inhibited mesothelioma proliferation. CONCLUSIONS: PTX-primed mesenchymal stromal cells successfully inhibit the in vitro proliferation of human mesothelioma cells. Further studies and in vivo testing are required to confirm our preliminary in vitro results as a potential new mesothelioma therapy based on cell drug delivery.

Cutting Edge: IgE Plays an Active Role in Tumor Immunosurveillance in Mice.

Exogenous IgE acts as an adjuvant in tumor vaccination in mice, and therefore a direct role of endogenous IgE in tumor immunosurveillance was investigated. By using genetically engineered mice, we found that IgE ablation rendered mice more susceptible to the growth of transplantable tumors. Conversely, a strengthened IgE response provided mice with partial or complete resistance to tumor growth, depending on the tumor type. By genetic crosses, we showed that IgE-mediated tumor protection was mostly lost in mice lacking FcεRI. Tumor protection was also lost after depletion of CD8(+) T cells, highlighting a cross-talk between IgE and T cell-mediated tumor immunosurveillance. Our findings provide the rationale for clinical observations that relate atopy with a lower risk for developing cancer and open new avenues for the design of immunotherapeutics relevant for clinical oncology.

Effect of an Activated Platelet Concentrate on Differentiated Cells Involved in Tissue Healing.

Tissue healing is a complex process involving several players such as cells and growth factors released from platelets upon activation. Today, platelet concentrates (PCs) are used in many different medical fields including oral, orthopaedic, and reconstructive surgery since they allow growth factors delivery to the injured site, aiming at enhancing tissue regeneration. The purpose of this in vitro study was to evaluate the effect of the acellular plasma of an activated platelet concentrate obtained using a manual protocol, on the proliferation, and biological activity of differentiated cells involved in tissue healing. Human osteoblasts and dermal fibroblasts were grown in serum-free medium supplemented with PC derived from several donors. Human osteoblast and human dermal fibroblast proliferation was assessed by MTT test after 7 days and cells were count up to 12-day incubation. Human osteoblast osteo-differentiation was tested after 7 and 14-day incubation by alkaline phosphatase assay. The addition of PC to the culture medium caused an increased proliferation with respect to cells grown in standard condition. The results of the present study suggest that PC supports the proliferation of terminally differentiated cells involved in wound healing and tissue regeneration, confirming its beneficial clinical application in regenerative therapies.