The idiopathic inflammatory myopathies are characterized by antibody- or cell-mediated immune response against unknown muscle tissue antigens. In these diseases a cellular infiltrate, composed of T and B lymphocytes, macrophages and NK cells, may invade muscle tissue with a gradient from the perivascular space to the endomysial compartment. Muscle cells may be actively involved in the processes of mononuclear cell recruitment and activation from the blood stream to the areas of inflammation. In order to verify this hypothesis, cultured human myoblasts were tested for their capacity to express different pro-inflammatory cytokines [IL-1alpha, IL-1beta, IL-6 and tumor necrosis factor (TNF)-alpha] and chemokines (IL-8, MCP-1 and RANTES) at the mRNA level and protein secretion, in the presence of the pro-inflammatory cytokines IFN-gamma and TNF-alpha alone or in combination. We confirmed that human myoblasts expressed IL-1alpha and IL-6 constitutively, while IL-1beta and TNF-alpha are detected only after treatment with pro-inflammatory cytokines; moreover, we observed that TNF-alpha was expressed on an autocrine fashion by myoblasts. IL-8 and RANTES were expressed constitutively while MCP-1 after proper induction. These molecular data were further confirmed by specific ELISA in the supernatant from cultured myoblasts. Our results underline the importance of human myoblasts in the recruitment of leukocytes from the blood stream and, most probably, in the cross-talk between infiltrating inflammatory cells and muscle cells, creating the conditions for a chronic inflammation. Moreover, the capacity of muscle cells to behave as cells of the immune system has to be kept in mind, also in view of i.m. vaccination and use of molecular engineered myoblasts as vehicles in gene therapy.

We investigated in vitro the properties of selected populations of cancer stem-like cells defined as tumorospheres that were obtained from human glioblastoma. We also assessed their potential and capability of differentiating into mature cells of the central nervous system. In vivo, their tumorigenicity was confirmed after transplantation into the brain of non-obese diabetic/severe combined immunodeficient (NOD-SCID) mice. The angiogenic potential of tumorospheres and glioblastoma-derived cells grown as adherent cells was revealed by evaluating the release of angiogenic factors such as vascular endothelial growth factor and CXCL12 by ELISA, as well as by rat aortic ring assay. The proliferative response of tumorospheres in the presence of CXCL12 was observed for the first time. Multidrug resistance-associated proteins 1 and 3 as well as other molecules conferring multidrug resistance were higher when compared with primary adherent cells derived from the same tumor. Finally, we obtained cells from the tumor developing after grafting that clearly expressed the putative neural stem cell marker CD133 as shown by FACS analysis and also nestin and CXCR4. The cells' positivity for glial fibrillary acidic protein was very low. Moreover these cells preserved their angiogenic potential. We conclude that human glioblastoma could contain tumor cell subsets with angiogenic and chemoresistance properties and that this chemoresistance potential is highly preserved by immature cells whereas the angiogenic potential is, to a higher extent, a property of mature cells. A better understanding of the features of these cell subsets may favor the development of more specifically targeted therapies.

A retroviral construct encoding polyoma middle-sized T antigen was used to generate transformed endothelial cell lines from heart (HSV), brain (B9V), and whole-embryo (E1OV) of C57BL/6 mice. When Izwected into syngeneic recipients, H5V and the less studied B9V and E1OV cells caused vascular tumors which, depending on the number of cefls inoculated ITo whom reprint requests should be addressed. 7291The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.

SummaryWhereas the signaling function of the interleukin 1 (IL-1) receptor type I (IL-1R I) has been well documented, the type II "receptor" has been suggested to act as a decoy target for this cytokine. Since IL-1 may represent a key target of the immunomodulatory and antiinflammatory properties of glucocorticoids (GC), the aim of this study was to investigate the effects of dexamethasone (Dex) on IL-1R expression in human polymorphonuclear leukocytes (PMN), which express predominantly the type II molecule (IL-1R II). We found that Dex augments the levels of steady state transcripts encoding the IL-1R I and, most prominently, those of IL-1R II. Dex induced both transcripts via transcription-dependent mechanisms and by prolongation of the mRNAs half-lives. Inhibition of protein synthesis superinduced basal and Dex-augmented IL-1R II mKNA, whereas it completely inhibited the induction by Dex of IL-1R I transcripts. Induction of IL-1R II mKNA by Dex was associated with augmented membrane expression and release of the type II IL-1 binding molecule. This effect was mediated by the GC receptor. Other steroids (17~5-estradiol, progesterone, and testostmone) were ineffective. The concentrations of IL-lot and IL-1 receptor antagonist required to displace the binding of IL-1/5 to the soluble form of the decoy molecule induced by Dex from PMN were, respectively, 100 and 2 times higher compared with IL-1/3. The induction by Dex of the type II receptor, a decoy molecule for IL-1, may contribute to the immunosuppressive and antiinflammatory activities of Dex.

Glioblastoma multiforme (GBM) is among the most deadly cancers. A number of studies suggest that a fraction of tumor cells with stem cell features (Glioma Stem-like Cells, GSC) might be responsible for GBM recurrence and aggressiveness. GSC similarly to normal neural stem cells, can form neurospheres (NS) in vitro, and seem to mirror the genetic features of the original tumor better than glioma cells growing adherently in the presence of serum. Using cDNA microarray analysis we identified a number of relevant genes for glioma biology that are differentially expressed in adherent cells and neurospheres derived from the same tumor. Fatty acid-binding protein 7 (FABP7) was identified as one of the most highly expressed genes in NS compared to their adherent counterpart. We found that down-regulation of FABP7 expression in NS by small interfering RNAs significantly reduced cell proliferation and migration. We also evaluated the potential involvement of FABP7 in response to radiotherapy, as this treatment may cause increased tumor infiltration. Migration of irradiated NS was associated to increased expression of FABP7. In agreement with this, in vivo reduced tumorigenicity of GBM cells with down-regulated expression of FABP7 was associated to decreased expression of the migration marker doublecortin. Notably, we observed that PPAR antagonists affect FABP7 expression and decrease the migration capability of NS after irradiation. As a whole, the data emphasize the role of FABP7 expression in GBM migration and provide translational hints on the timing of treatment with anti-FABP7 agents like PPAR antagonists during GBM evolution.