Search

Type 1 diabetes mellitus (T1DM) is caused by the selective destruction of insulin-producing β-cells. This process is mediated by cells of the immune system through release of nitric oxide, free radicals and pro-inflammatory cytokines, which induce a complex network of intracellular signalling cascades, eventually affecting the expression of genes involved in β-cell survival. The aim of our study was to investigate possible mechanisms of resistance to cytokine-induced β-cell death. To this purpose, we created a cytokine-resistant β-cell line (β-TC3R) by chronically treating the β-TC3 murine insulinoma cell line with IL-1β + IFN-γ. β-TC3R cells exhibited higher proliferation rate and resistance to cytokine-mediated cell death in comparison to the parental line. Interestingly, they maintained expression of β-cell specific markers, such as PDX1, NKX6.1, GLUT2 and insulin. The analysis of the secretory function showed that β-TC3R cells have impaired glucose-induced c-peptide release, which however was only moderately reduced after incubation with KCl and tolbutamide. Gene expression analysis showed that β-TC3R cells were characterized by downregulation of IL-1β and IFN-γ receptors and upregulation of SOCS3, the classical negative regulator of cytokines signaling. Comparative proteomic analysis showed specific upregulation of 35 proteins, mainly involved in cell death, stress response and folding. Among them, SUMO4, a negative feedback regulator in NF-kB and JAK/STAT signaling pathways, resulted hyper-expressed. Silencing of SUMO4 was able to restore sensitivity to cytokine-induced cell death in β-TC3R cells, suggesting it may play a key role in acquired cytokine resistance by blocking JAK/STAT and NF-kB lethal signaling. In conclusion, our study represents the first extensive proteomic characterization of a murine cytokine-resistant β-cell line, which might represent a useful tool for studying the mechanisms involved in resistance to cytokine-mediated β-cell death. This knowledge may be of potential benefit for patients with T1DM. In particular, SUMO4 could be used as a therapeutical target.

BackgroundRecent publications suggest that neoplastic initiation and growth are dependent on a small subset of cells, termed cancer stem cells (CSCs). Anaplastic Thyroid Carcinoma (ATC) is a very aggressive solid tumor with poor prognosis, characterized by high dedifferentiation. The existence of CSCs might account for the heterogeneity of ATC lesions. CD133 has been identified as a stem cell marker for normal and cancerous tissues, although its biological function remains unknown.Methodology/principal findingsATC cell lines ARO, KAT-4, KAT-18 and FRO were analyzed for CD133 expression. Flow cytometry showed CD133(pos) cells only in ARO and KAT-4 (64+/-9% and 57+/-12%, respectively). These data were confirmed by qRT-PCR and immunocytochemistry. ARO and KAT-4 were also positive for fetal marker oncofetal fibronectin and negative for thyrocyte-specific differentiating markers thyroglobulin, thyroperoxidase and sodium/iodide symporter. Sorted ARO/CD133(pos) cells exhibited higher proliferation, self-renewal, colony-forming ability in comparison with ARO/CD133(neg). Furthermore, ARO/CD133(pos) showed levels of thyroid transcription factor TTF-1 similar to the fetal thyroid cell line TAD-2, while the expression in ARO/CD133(neg) was negligible. The expression of the stem cell marker OCT-4 detected by RT-PCR and flow cytometry was markedly higher in ARO/CD133(pos) in comparison to ARO/CD133(neg) cells. The stem cell markers c-KIT and THY-1 were negative. Sensitivity to chemotherapy agents was investigated, showing remarkable resistance to chemotherapy-induced apoptosis in ARO/CD133(pos) when compared with ARO/CD133(neg) cells.Conclusions/significanceWe describe CD133(pos) cells in ATC cell lines. ARO/CD133(pos) cells exhibit stem cell-like features--such as high proliferation, self-renewal ability, expression of OCT-4--and are characterized by higher resistance to chemotherapy. The simultaneous positivity for thyroid specific factor TTF-1 and onfFN suggest they might represent putative thyroid cancer stem-like cells. Our in vitro findings might provide new insights for novel therapeutic approaches.

In the last three decades, the constantly increasing need for therapies, efficiently preventing and/or treating human diseases, has raised the interest in Regenerative Medicine (RM). RM is based on employing mesenchymal stem cells (MSCs), that showed to have great proliferation, self-renewal and multilineage differentiation potential, in vitro as well as in vivo. The opportunity of an accessible, painless and low-cost reservoir of MSCs constitutes the first important step of a successful regenerative therapy to include in the current clinical practice. Oral cavity has recently demonstrated to contain different MSCs niches: dental pulp from permanent and deciduous teeth, periodontal ligament, dental follicle, apical papilla and mucosa. MSCs from dental pulp of deciduous teeth, naturally lost in pediatric age, and the oral mucosa have shown to be easily harvested and to have a promising regenerative potential. Thus, the aim of the paper is to review the potentialities of human exfoliated deciduous teeth stem cells (SHEDs) and oral mucosa stem cells (OMSCs) in RM, with the purpose of their use as accessible source of MSCs for the future of pediatric patient.

// Stefania Raimondo 1 , Flores Naselli 1 , Simona Fontana 1 , Francesca Monteleone 1 , Alessia Lo Dico 1 , Laura Saieva 1 , Giovanni Zito 2 , Anna Flugy 1 , Mauro Manno 3 , Maria Antonietta Di Bella 1 , Giacomo De Leo 1 , Riccardo Alessandro 1 1 Dipartimento di Biopatologia e Biotecnologie Mediche, Universita degli Studi di Palermo, sezione di Biologia e Genetica, Palermo, Italy 2 Laboratorio di Ingegneria Tissutale – Piattaforme Innovative per l’Ingegneria Tissutale (PON01–00829), Istituto Ortopedico Rizzoli, Palermo, Italy 3 Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Palermo, Italy Correspondence to: Riccardo Alessandro, e-mail: riccardo.alessandro@unipa.it Keywords: cancer, exosome-like nanovesicles, Citrus limon L., TRAIL-mediated cell death Received: April 03, 2015 Accepted: May 08, 2015 Published: May 18, 2015 ABSTRACT Nanosized vesicles are considered key players in cell to cell communication, thus influencing physiological and pathological processes, including cancer. Nanovesicles have also been found in edible-plants and have shown therapeutic activity in inflammatory bowel diseases; however information on their role in affecting cancer progression is missing. Our study identify for the first time a fraction of vesicles from lemon juice ( Citrus limon L.), obtained as a result of different ultracentrifugation, with density ranging from 1,15 to 1,19 g/ml and specific proteomic profile. By using an in vitro approach, we show that isolated nanovesicles inhibit cancer cell proliferation in different tumor cell lines, by activating a TRAIL-mediated apoptotic cell death. Furthermore, we demonstrate that lemon nanovesicles suppress CML tumor growth in vivo by specifically reaching tumor site and by activating TRAIL-mediated apoptotic cell processes. Overall, this study suggests the possible use of plant-edible nanovesicles as a feasible approach in cancer treatment.