The Contribution of Electron Paramagnetic Resonance to Melanoma Research

The incidence of malignant melanoma, the most dangerous form of skin cancer, is rising each year. However, some aspects of the tumor initiation and development are still unclear, and the current method of diagnosis, based on the visual aspect of the tumor, shows limitations. For these reasons, developments of new techniques are ongoing to improve basic knowledge on the disease and diagnosis of tumors in individual patients. This paper shows how electron paramagnetic resonance (EPR), a method able to detect free radicals trapped in melanin pigments, has recently brought its unique value to this specific field. The general principles of the method and the convenience of melanin as an endogenous substrate for EPR measurements are explained. Then, the way by which EPR has recently helped to assess the contribution of ultraviolet rays (UVA and UVB) to the initiation of melanoma is described. Finally, we describe the improvements of EPR spectrometry and imaging in the detection and mapping of melanin pigments inside ex vivo and in vivo melanomas. We discuss how these advances might improve the diagnosis of this skin cancer and point out the present capabilities and limitations of the method

Increasing Antiproliferative Properties of Endocannabinoids in N1E-115 Neuroblastoma Cells through Inhibition of Their Metabolism

The antitumoral properties of endocannabinoids received a particular attention these last few years. Indeed, these endogenous molecules have been reported to exert cytostatic, apoptotic and antiangiogenic effects in different tumor cell lines and tumor xenografts. Therefore, we investigated the cytotoxicity of three N-acylethanolamines – N-arachidonoylethanolamine (anandamide, AEA), N-palmitoylethanolamine (PEA) and N-oleoylethanolamine (OEA) - which were all able to time- and dose-dependently reduce the viability of murine N1E-115 neuroblastoma cells. Moreover, several inhibitors of FAAH and NAAA, whose presence was confirmed by RT-PCR in the cell line, induced cell cytotoxicity and favored the decrease in cell viability caused by N-acylethanolamines. The most cytotoxic treatment was achieved by the co-incubation of AEA with the selective FAAH inhibitor URB597, which drastically reduced cell viability partly by inhibiting AEA hydrolysis and consequently increasing AEA levels. This combination of molecules synergistically decreased cell proliferation without inducing cell apoptosis or necrosis. We found that these effects are independent of cannabinoid, TRPV1, PPARα, PPARγ or GPR55 receptors activation but seem to occur through a lipid raft-dependent mechanism. These findings further highlight the interest of targeting the endocannabinoid system to treat cancer. More particularly, this emphasizes the great potential benefit of designing novel anti-cancerous therapies based on the association of endocannabinoids and inhibitors of their hydrolysis

The impact of particulate electron paramagnetic resonance oxygen sensors on fluorodeoxyglucose imaging characteristics detected via positron emission tomography

During a first-in-humans clinical trial investigating electron paramagnetic resonance tumor oximetry, a patient injected with the particulate oxygen sensor Printex ink was found to have unexpected fluorodeoxyglucose (FDG) uptake in a dermal nodule via positron emission tomography (PET). This nodule co-localized with the Printex ink injection; biopsy of the area, due to concern for malignancy, revealed findings consistent with ink and an associated inflammatory reaction. Investigations were subsequently performed to assess the impact of oxygen sensors on FDG-PET/CT imaging. A retrospective analysis of three clinical tumor oximetry trials involving two oxygen sensors (charcoal particulates and LiNc-BuO microcrystals) in 22 patients was performed to evaluate FDG imaging characteristics. The impact of clinically used oxygen sensors (carbon black, charcoal particulates, LiNc-BuO microcrystals) on FDG-PET/CT imaging after implantation in rat muscle (n = 12) was investigated. The retrospective review revealed no other patients with FDG avidity associated with particulate sensors. The preclinical investigation found no injected oxygen sensor whose mean standard uptake values differed significantly from sham injections. The risk of a false-positive FDG-PET/CT scan due to oxygen sensors appears low. However, in the right clinical context the potential exists that an associated inflammatory reaction may confound interpretation

シェアビジネスにおけるSNSの信頼性に関する研究-シェアビジネスの先端事例ケーススタディとSNSの信頼性の影響に関する実証分析

Otaru University of Commerce（小樽商科大学）博士（商学）doctoralcours

Increased Programmed Death-1 Molecule Expression in Cytomegalovirus Disease and Acute Graft-versus-Host Disease after Allogeneic Hematopoietic Cell Transplantation

To study the role of the programmed death-1 molecule (PD-1) in cytomegalovirus (CMV) infection and disease after allogeneic hematopoietic cell transplantation (HCT), 206 subjects were followed prospectively for immune response to CMV and assigned to 3 groups based on CMV outcome. The subjects were analyzed retrospectively for PD-1 expression in cryopreserved CD4+ and CD8+T cells collected at days 40, 90, 120, 150, 180, and 360 posttransplantation. HCT recipients with CMV disease (n=14) were compared with recipients with prolonged CMV infection, but no CMV disease (median duration of infection, 3 months; n=14) and with controls with no CMV infection who received similar transplants (n=22). The CMV disease group had a significantly higher mean fluorescein intensity of PD-1 in CD4+ (P < .05) and CD8+ (P < .05) lymphocytes at all time points studied. PD-1 expression also was significantly elevated in those with severe acute graft-versus-host disease (aGVHD), including the no-viremia group. The data suggest that PD-1 is induced by aGVHD even in the absence of CMV infection. This enhanced PD-1 expression during severe aGVHD and with CMV reactivation could explain the known role of aGVHD as a risk factor for CMV disease

Renversement des hétérogénéités spatiale et temporelle de la perfusion tumorale identifie la tumeur tonus vasculaire comme une variable ajustable pour améliorer la prestation de drogue

peer reviewedMaturation de la vascularisation tumorale implique le recrutement de péricytes qui protègent les tubes endothéliales provenant de diverses contraintes, y compris les médicaments anti-angiogéniques. Mural cells also provide mature tumor blood vessels with the ability to either relax or contract in response to substances present in the tumor microenvironment. cellules murale également fournir d'âge mûr vaisseaux sanguins des tumeurs avec la possibilité de détendre ou se contracter en réponse à des substances présentes dans le microenvironnement de la tumeur. The observed cyclic alterations in tumor blood flow and the associated deficit in chemotherapeutic drug delivery could in part arise from this vasomodulatory influence. To test this hypothesis, we focused on endothelin-1 (ET-1), which, besides its autocrine effects on tumor cell growth, is a powerful vasoconstrictor. Les cycliques altérations observées dans la circulation sanguine des tumeurs et le déficit lié à la livraison de médicaments chimiothérapeutiques pourrait en partie résulter de cette influence vasomodulatory. Pour tester cette hypothèse, nous nous sommes concentrés sur l'endothéline-1 (ET-1), qui, outre ses effets sur la tumeur autocrine la croissance cellulaire, est un puissant vasoconstricteur. We first document that an ET A receptor antagonist induced relaxation of microdissected tumor arterioles and selectively and quantitatively increased tumor blood flow in experimental tumor models. Nous premier document qu'un antagoniste des récepteurs ET A la relaxation induite par des artérioles tumeur microdisséquées et sélectivement et quantitativement l'augmentation du débit sanguin tumorale dans des modèles expérimentaux de tumeurs. We then combined dye staining of functional vessels, fluorescent microsphere-based mapping, and magnetic resonance imaging to identify heterogeneities in tumor blood flow and to examine the reversibility of such phenomena. Nous avons ensuite combiné de la coloration des vaisseaux fonctionnels, fluorescent à base de microsphères de cartographie et d'imagerie par résonance magnétique pour identifier les hétérogénéités du débit sanguin des tumeurs et d'examiner la réversibilité de ces phénomènes. Data from all these techniques concurred to show that administration of an ET A receptor antagonist could reduce the extent of underperfused tumor areas, proving the key role of vessel tone variations in tumor blood flow heterogeneity. Les données de toutes ces techniques d'accord pour montrer que l'administration d'un antagoniste des récepteurs ET A pourrait réduire l'étendue des zones tumorales underperfused, ce qui prouve le rôle clé du navire variations des flux de ton hétérogénéité sanguins des tumeurs. We also provide evidence that ET A antagonist administration could, despite an increase in tumor interstitial fluid pressure, improve access of cyclophosphamide to the tumor compartment and significantly influence tumor growth. Nous avons également fournir la preuve que l'administration antagoniste ET A pourrait, en dépit d'une augmentation de la tumeur interstitielle pression d'un fluide, d'améliorer l'accès de cyclophosphamide dans le compartiment des tumeurs et une influence significative sur la croissance tumorale. In conclusion, tumor endogenous ET-1 production participates largely in the temporal and spatial variations in tumor blood flow. En conclusion, une tumeur ET-1 endogène de production participe largement à l'espace et les variations temporelles du flux sanguin tumoral. ET A antagonist administration may wipe out such heterogeneities, thus representing an adjuvant strategy that could improve the delivery of conventional chemotherapy to tumors. ET Une administration antagoniste peut effacer ces hétérogénéités, ce qui représente une stratégie adjuvant qui pourraient améliorer la prestation de la chimiothérapie conventionnelle des tumeurs. [Mol Cancer Ther 2006;5(6):1620–7] [Cancer Mol Il 2006; 5 (6) :1620-7]Maturation of tumor vasculature involves the recruitment of pericytes that protect the endothelial tubes from a variety of stresses, including antiangiogenic drugs. Mural cells also provide mature tumor blood vessels with the ability to either relax or contract in response to substances present in the tumor microenvironment. The observed cyclic alterations in tumor blood flow and the associated deficit in chemotherapeutic drug delivery could in part arise from this vasomodulatory influence. To test this hypothesis, we focused on endothelin-1 (ET-1), which, besides its autocrine effects on tumor cell growth, is a powerful vasoconstrictor. We first document that an ETA receptor antagonist induced relaxation of microdissected tumor arterioles and selectively and quantitatively increased tumor blood flow in experimental tumor models. We then combined dye staining of functional vessels, fluorescent microsphere-based mapping, and magnetic resonance imaging to identify heterogeneities in tumor blood flow and to examine the reversibility of such phenomena. Data from all these techniques concurred to show that administration of an ETA receptor antagonist could reduce the extent of underperfused tumor areas, proving the key role of vessel tone variations in tumor blood flow heterogeneity. We also provide evidence that ETA antagonist administration could, despite an increase in tumor interstitial fluid pressure, improve access of cyclophosphamide to the tumor compartment and significantly influence tumor growth. In conclusion, tumor endogenous ET-1 production participates largely in the temporal and spatial variations in tumor blood flow. ETA antagonist administration may wipe out such heterogeneities, thus representing an adjuvant strategy that could improve the delivery of conventional chemotherapy to tumors. [Mol Cancer Ther 2006;5(6):1620–7

Macrophage skewing by Phd2 haplodeficiency prevents ischemia by inducing arteriogenesis

The authors are thankful to Dr. P. Carmeliet for scientific discussion and support. VE-Cadherin:CreERT and PDGFRB:Cre transgenic mice were generated at the Cancer Research UK (London, UK) and kindly donated by Dr. R. Adams. The IKKβ floxed mice are a generous gift of Dr. M. Karin (UCSD, La Jolla, CA). The hydroxylase-deficient PHD2 construct was given by Dr. P. Ratcliffe (Oxford, UK).PHD2 serves as an oxygen sensor that rescues blood supply by regulating vessel formation and shape in case of oxygen shortage. However, it is unknown whether PHD2 can influence arteriogenesis. Here we studied the role of PHD2 in collateral artery growth by using hindlimb ischaemia as a model, a process that compensates for the lack of blood flow in case of major arterial occlusion. We show that Phd2 (also known as Egln1) haplodeficient (Phd2(+/-)) mice displayed preformed collateral arteries that preserved limb perfusion and prevented tissue necrosis in ischaemia. Improved arteriogenesis in Phd2(+/-) mice was due to an expansion of tissue-resident, M2-like macrophages and their increased release of arteriogenic factors, leading to enhanced smooth muscle cell (SMC) recruitment and growth. Both chronic and acute deletion of one Phd2 allele in macrophages was sufficient to skew their polarization towards a pro-arteriogenic phenotype. Mechanistically, collateral vessel preconditioning relied on the activation of canonical NF-κB pathway in Phd2(+/-) macrophages. These results unravel how PHD2 regulates arteriogenesis and artery homeostasis by controlling a specific differentiation state in macrophages and suggest new treatment options for ischaemic disorders.This work was supported by grants from FWO (G.0726.10), Belgium, and from VIB. ED was granted by ARC, SC by FCT, RLO and VF by FWO, AH by DFG. CR was supported by COST action TD0901. MDP was supported by an ERC starting grant

The association of N-palmitoylethanolamine with the FAAH inhibitor URB597 impairs melanoma growth through a supra-additive action

<p>Abstract</p> <p>Background</p> <p>The incidence of melanoma is considerably increasing worldwide. Frequent failing of classical treatments led to development of novel therapeutic strategies aiming at managing advanced forms of this skin cancer. Additionally, the implication of the endocannabinoid system in malignancy is actively investigated.</p> <p>Methods</p> <p>We investigated the cytotoxicity of endocannabinoids and their hydrolysis inhibitors on the murine B16 melanoma cell line using a MTT test. Enzyme and receptor expression was measured by RT-PCR and enzymatic degradation of endocannabinoids using radiolabeled substrates. Cell death was assessed by Annexin-V/Propidium iodine staining. Tumors were induced in C57BL/6 mice by s.c. flank injection of B16 melanoma cells. Mice were injected i.p. for six days with vehicle or treatment, and tumor size was measured each day and weighted at the end of the treatment. Haematoxylin-Eosin staining and TUNEL assay were performed to quantify necrosis and apoptosis in the tumor and endocannabinoid levels were quantified by HPLC-MS. Tube formation assay and CD31 immunostaining were used to evaluate the antiangiogenic effects of the treatments.</p> <p>Results</p> <p>The <it>N</it>-arachidonoylethanolamine (anandamide, AEA), 2-arachidonoylglycerol and <it>N</it>- palmitoylethanolamine (PEA) reduced viability of B16 cells. The association of PEA with the fatty acid amide hydrolase (FAAH) inhibitor URB597 considerably reduced cell viability consequently to an inhibition of PEA hydrolysis and an increase of PEA levels. The increase of cell death observed with this combination of molecules was confirmed in vivo where only co-treatment with both PEA and URB597 led to decreased melanoma progression. The antiproliferative action of the treatment was associated with an elevation of PEA levels and larger necrotic regions in the tumor.</p> <p>Conclusions</p> <p>This study suggests the interest of targeting the endocannabinoid system in the management of skin cancer and underlines the advantage of associating endocannabinoids with enzymatic hydrolysis inhibitors. This may contribute to the improvement of long-term palliation or cure of melanoma.</p