Inhibition of DNA methylation sensitizes glioblastoma for tumor necrosis factor-related apoptosis-inducing ligand-mediated destruction

Life expectancy of patients affected by glioblastoma multiforme is extremely low. The therapeutic use of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been proposed to treat this disease based on its ability to kill glioma cell lines in vitro and in vivo. Here, we show that, differently from glioma cell lines, glioblastoma multiforme tumors were resistant to TRAIL stimulation because they expressed low levels of caspase-8 and high levels of the death receptor inhibitor PED/PEA-15. Inhibition of methyltransferases by decitabine resulted in considerable up-regulation of TRAIL receptor-1 and caspase-8, down-regulation of PED/PEA-15, inhibition of cell growth, and sensitization of primary glioblastoma cells to TRAIL-induced apoptosis. Exogenous caspase-8 expression was the main event able to restore TRAIL sensitivity in primary glioblastoma cells. The antitumor activity of decitabine and TRAIL was confirmed in vivo in a mouse model of glioblastoma multiforme. Evaluation of tumor size, apoptosis, and caspase activation in nude mouse glioblastoma multiforme xenografts showed dramatic synergy of decitabine and TRAIL in the treatment of glioblastoma, whereas the single agents were scarcely effective in terms of reduction of tumor mass, apoptosis induction, and caspase activation. Thus, the combination of TRAIL and demethylating agents may provide a key tool to overcome glioblastoma resistance to therapeutic treatments. ©2005 American Association for Cancer Research

Mek inhibition results in marked antitumor activity against metastatic melanoma patient-derived melanospheres and in melanosphere-generated xenografts

One of the key oncogenic pathways involved in melanoma aggressiveness, development and progression is the RAS/BRAF/MEK pathway, whose alterations are found in most patients. These molecular anomalies are promising targets for more effective anti-cancer therapies. Some Mek inhibitors showed promising antitumor activity, although schedules and doses associated with low systemic toxicity need to be defined. In addition, it is now accepted that cancers can arise from and be maintained by the cancer stem cells (CSC) or tumor-initiating cells (TIC), commonly expanded in vitro as tumorspheres from several solid tumors, including melanoma (melanospheres). Here, we investigated the potential targeting of MEK pathway by exploiting highly reliable in vitro and in vivo pre-clinical models of melanomas based on melanospheres, as melanoma initiating cells (MIC) surrogates. MEK inhibition, through PD0325901, provided a successful strategy to affect survival of mutated-BRAF melanospheres and growth of wild type-BRAF melanospheres. A marked citotoxicity was observed in differentated melanoma cells regardless BRAF mutational status. PD0325901 treatment, dramatically inhibited growth of melanosphere-generated xenografts and determined impaired tumor vascularization of both mutated- and wild type-BRAF tumors, in the absence of mice toxicity. These results suggest that MEK inhibition might represent a valid treatment option for patients with both mutated- or wild type-BRAF melanomas, affecting tumor growth through multiple targets. \uc2\ua9 2013 Sette et al.; licensee BioMed Central Ltd

‘Capturing Anarchists Across Borders’: the transnational dimensions of Italian antimilitarist campaigns, 1911-1914

This article stems from the vibrant debate on methodological developments and new perspectives that has been inspired by a recent upsurge of interest in the transnational history of labour and radical movements. It engages with the problematic question of the integration between different scales of analysis in the study of radicalism: the ‘transnational’, ‘national’ and ‘local’ or ‘trans-local’. The article reverts the study of transnational anarchism back to a ‘national’ and ‘trans-local’ perspective: the analysis of the intersection between the networks of those who migrated from Italy and those who stayed there provides a fruitful way to uncover the dynamics within the transnational anarchist movement and the inter-playing, in both directions, between: home country - exiles’ communities - host countries. The article focuses on the crucial - but still unexplored - contributions in terms of propaganda, theoretical debate, financing, and counterculture production that the communities of Italian anarchists abroad (among them London, Paris, Berne, Marseille, Barre, and Buenos Aires) gave to the antimilitarist campaigns against the Italian colonial enterprise in Libya and for the release of Augusto Masetti - the soldier who shot at his colonel whilst addressing troops leaving for the frontline - from 1911 to 1914. The investigation of the initiatives that the anarchist exiles established and coordinated with their comrades in Italy provides a significant case study not only for the understanding of network-based transnational anarchism but also to reflect on the mechanisms of political migration and its influence in the development of social conflicts

Human Motor Cortex Functional Changes in Acute Stroke: Gender Effects

The acute phase of stroke is accompanied by functional changes in the activity and interplay of both hemispheres. In healthy subjects, gender is known to impact the functional brain organization.We investigated whether gender influences also acute stroke functional changes. In thirty-five ischemic stroke patients, we evaluated the excitability of the affected (AH) and unaffected hemisphere (UH) by measuring resting and active motor threshold and motor-evoked potential amplitude under baseline conditions and after intermittent theta burst stimulation (iTBS) of AH. We also computed an index of the excitability balance between the hemispheres, laterality indexes (LI), to evidence hemispheric asymmetry. Active motor threshold differed significantly between AH and UH only in the male group (p=0.004), not in females (p>0.200), and both LIAMT and LIRMT were significantly higher in males than in females (respectively p=0.033 and p=0.042). LTP-like activity induced by iTBS in AH was more frequent in females. Gender influences the functional excitability changes that take place after human stroke and the level of LTP that can be induced by repetitive stimulation. This knowledge is of high value in the attempt of individualizing to different genders any non-invasive stimulation strategy designed to foster stroke recovery

CD95 DISC formation and internalizzation occur in lipid rafts of typeI and typeII cells

We investigated the membrane localization of CD95 in type I and type II cells, which differ in their ability to recruit and activate caspase-8. We found that CD95 was preferentially located in lipid rafts of type I cells, while it was present both in raft and non-raft plasma membrane sub-domains of type II cells. After stimulation, CD95 located in phospholipid-rich plasma membrane was recruited to lipid rafts in both types of cells. Similarly, CD95 cross-linking resulted in caspase-independent translocation of FADD/MORT1 and caspase-8 to the lipid rafts, which was prevented by a death domain-defective receptor. CD95 internalization was then rapid in type I and delayed in type II cells and showed a substantial correlation with the kinetics of Fas-associated death domain (FADD) and caspase-8 recruitment to lipid rafts. Finally, electron microscopy analysis showed that after CD95 stimulation lipid rafts aggregated in large clusters that were internalized in endosomal vesicles, where caspase-8 underwent massive processing. Taken together, our data demonstrate that CD95 death-inducing signaling complex formation and internalization in type I and type II cells occur in lipid rafts, which are a major site of caspase-8 activation. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA