Dendritic cells are defective in breast cancer patients: a potential role for polyamine in this immunodeficiency

INTRODUCTION: Dendritic cells (DCs) are antigen-presenting cells that are currently employed in cancer clinical trials. However, it is not clear whether their ability to induce tumour-specific immune responses when they are isolated from cancer patients is reduced relative to their ability in vivo. We determined the phenotype and functional activity of DCs from cancer patients and investigated the effect of putrescine, a polyamine molecule that is released in large amounts by cancer cells and has been implicated in metastatic invasion, on DCs. METHODS: The IL-4/GM-CSF (granulocyte–macrophage colony-stimulating factor) procedure for culturing blood monocyte-derived DCs was applied to cells from healthy donors and patients (17 with breast, 7 with colorectal and 10 with renal cell carcinoma). The same peroxide-treated tumour cells (M74 cell line) were used for DC pulsing. We investigated the effects of stimulation of autologous lymphocytes by DCs pulsed with treated tumour cells (DC-Tu), and cytolytic activity of T cells was determined in the same target cells. RESULTS: Certain differences were observed between donors and breast cancer patients. The yield of DCs was dramatically weaker, and expression of MHC class II was lower and the percentage of HLA-DR(-)Lin(- )cells higher in patients. Whatever combination of maturating agents was used, expression of markers of mature DCs was significantly lower in patients. Also, DCs from patients exhibited reduced ability to stimulate cytotoxic T lymphocytes. After DC-Tu stimulation, specific cytolytic activity was enhanced by up to 40% when DCs were from donors but only up to 10% when they were from patients. IFN-γ production was repeatedly found to be enhanced in donors but not in patients. By adding putrescine to DCs from donors, it was possible to enhance the HLA-DR(-)Lin(- )cell percentage and to reduce the final cytolytic activity of lymphocytes after DC-Tu stimulation, mimicking defective DC function. These putrescine-induced deficiencies were reversed by treating DCs with all-trans retinoic acid. CONCLUSION: These data are consistent with blockade of antigen-presenting cells at an early stage of differentiation in patients with breast cancer. Putrescine released in the microenvironmement of DCs could be involved in this blockade. Use of all-trans retinoic acid treatment to reverse this blockade and favour ex vivo expansion of antigen-specific T lymphocytes is of real interest

Tumeur adénomatoïde multinodulaire de l'utérus chez une patiente avec allogreffe rénale. [Multinodular-adenomatoid tumor of the uterus in a patient with a renal allograft]

International audienceA case of diffuse-adenomatoid tumor of the uterus occurring in a 43-year-old patient with a renal-allograft transplant is reported. Grossly, the lesions were thought to be multiple leiomyomas. The diagnosis was supported by the adenomatoid and angiomatoid histologic patterns and the mesothelial immunophenotype. Diffuse-adenomatoid tumor of the uterus is a rare and benign lesion, usually reported in patients with immunodeficiency and renal transplant

Differential diagnosis of atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma: utility of p16 in combination with MDM2 and CDK4 immunohistochemistry

International audienceThe differential diagnosis between atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDLPS) and dedifferentiated liposarcoma (DDLPS) from their morphologic counterparts is challenging. Currently, the diagnosis is guided by MDM2 and CDK4 immunohistochemistry (IHC) and is confirmed by the amplification of the corresponding genes. Recently, p16 IHC has been proposed as a useful diagnostic biomarker. The objective was to assess the utility of p16 IHC in the differential diagnosis of ALT/WDLPS and DDLPS. Our series included 101 tumors that were previously analyzed using fluorescence in situ hybridization for MDM2 and CDK4 amplification. We compared sensitivity and specificity of p16 IHC to MDM2 and CDK4 IHC in the differential diagnosis of ALT-WDLPS (n=19) versus benign adipocytic tumors (n=44) and DDLPS (n=18) versus mimicking sarcomas (n=20). In the differential diagnosis of ALT-WDLPS, p16 had a sensitivity of 89.5% but a specificity of 68.2%, which was impaired by false-positive lipomas with secondary changes, especially in biopsies. Likewise, in the differential diagnosis of DDLPS, p16 had a sensitivity of 94.4% and a specificity of 70%, which hampered its use as a single marker. However, adding p16 to MDM2 and/or CDK4 increased diagnostic specificity. Indeed, MDM2+/p16+ tumors were all ALT-WDLPS, and MDM2-/p16- tumors were all benign adipocytic tumors. Moreover, all MDM2+/CDK4+/p16+ tumors were DDLPS, and the MDM2-/CDK4-/p16- tumor was an undifferentiated sarcoma. Although the use of p16 as a single immunohistochemical marker is limited by its specificity, its combination with MDM2 and CDK4 IHC may help discriminate ALT-WDLPS/DDLPS

MITF - A controls branching morphogenesis and nephron endowment.

Congenital nephron number varies widely in the human population and individuals with low nephron number are at risk of developing hypertension and chronic kidney disease. The development of the kidney occurs via an orchestrated morphogenetic process where metanephric mesenchyme and ureteric bud reciprocally interact to induce nephron formation. The genetic networks that modulate the extent of this process and set the final nephron number are mostly unknown. Here, we identified a specific isoform of MITF (MITF-A), a bHLH-Zip transcription factor, as a novel regulator of the final nephron number. We showed that overexpression of MITF-A leads to a substantial increase of nephron number and bigger kidneys, whereas Mitfa deficiency results in reduced nephron number. Furthermore, we demonstrated that MITF-A triggers ureteric bud branching, a phenotype that is associated with increased ureteric bud cell proliferation. Molecular studies associated with an in silico analyses revealed that amongst the putative MITF-A targets, Ret was significantly modulated by MITF-A. Consistent with the key role of this network in kidney morphogenesis, Ret heterozygosis prevented the increase of nephron number in mice overexpressing MITF-A. Collectively, these results uncover a novel transcriptional network that controls branching morphogenesis during kidney development and identifies one of the first modifier genes of nephron endowment

Capitales européennes et diversité culturelle

A l'occasion de l'exposition Paris-Londres, Music Migrations, 1962-1989, la revue publie certaines contributions d'un séminaire de recherche sur la place et le rôle de la diversité culturelle dans quatre capitales européennes (Berlin, Londres, Madrid et Paris). Les articles analysent la manière dont la présence des populations immigrées a pu susciter des transferts et une reconnaissance de leurs ressources culturelles vers les scènes artistiques, culturelles et patrimoniales. L'histoire de ces métropoles montre que l'accueil des artistes étrangers est aussi un vecteur d'hybridation culturelle et de modernité

Beta-alanine supplementation in patients with COPD receiving non-linear periodised exercise training or neuromuscular electrical stimulation: protocol of two randomised, double-blind, placebo-controlled trials

International audienceIntroduction: Exercise intolerance is common in patients with chronic obstructive pulmonary disease (COPD) and, although multifactorial, it is largely caused by lower-limb muscle dysfunction. Research has shown that patients with severe to very severe COPD have significantly lower levels of muscle carnosine, which acts as a pH buffer and antioxidant. Beta-alanine (BA) supplementation has been shown to consistently elevate muscle carnosine in a variety of populations and may therefore improve exercise tolerance and lower-limb muscle function. The primary objective of the current studies is to assess the beneficial effects of BA supplementation in enhancing exercise tolerance on top of two types of exercise training (non-linear periodised exercise (NLPE) training or neuromuscular electrical stimulation (NMES)) in patients with COPD.Methods and analysis: Two randomised, double-blind, placebo-controlled trials have been designed. Patients will routinely receive either NLPE (BASE-TRAIN trial) or NMES (BASE-ELECTRIC trial) as part of standard exercise-based care during their 8-to-10 week pulmonary rehabilitation (PR) programme. A total of 222 patients with COPD (2×77 = 154 patients in the BASE-TRAIN trial and 2×34 = 68 patients in the BASE-ELECTRIC trial) will be recruited from two specialised PR centres in The Netherlands. For study purposes, patients will receive 3.2 g of oral BA supplementation or placebo per day. Exercise tolerance is the primary outcome, which will be assessed using the endurance shuttle walk test (BASE-TRAIN) or the constant work rate cycle test (BASE-ELECTRIC). Furthermore, quadriceps muscle strength and endurance, cognitive function, carnosine levels (in muscle), BA levels (in blood and muscle), markers of oxidative stress and inflammation (in blood, muscles and lungs), physical activity and quality of life will be measured.Ethics and dissemination: Both trials were approved by CMO Regio Arnhem-Nijmegen, The Netherlands (NL70781.091.19. and NL68757.091.19).Trial registration number: NTR8427 (BASE-TRAIN) and NTR8419 (BASE-ELECTRIC)

Characterization of MITF-A transgenic mice.

<p>Characterization of MITF-A transgenic mice.</p

Generation of MITF-A transgenic mice.

<p><b>A)</b> Schematic representation of the Ksp-cadherin-FLAG-MITF-A transgene. <b>B)</b> <i>Mitf-A</i> mRNA expression evaluated by quantitative RT-PCR in kidneys from wild-type (WT), heterozygous (HE) and homozygous (HO) MITF-A transgenic mice (line 42) 2 months after birth. Data are means ± SEM; n = 4–6 per each genotype. ANOVA followed by Tukey-Kramer test; transgenic <i>versus</i> wild-type mice: ** P < 0.01, *** P < 0.001. <b>C)</b> MITF-A protein expression evaluated by western blot on kidney nuclear protein extracts from WT, HE and HO MITF-A transgenic mice 2 months after birth. This is a representative image of three experiments. Nuclear protein extracts from <i>Mitfa</i>^-/- kidneys were used as a negative control; crude extracts from renal cells transfected with either FLAG-MITF-A plasmid (lane 1) or MITF-A plasmid (lane 2) were used as a positive control. Lamin A/C was used as control of nuclear protein amount. IB = immunoblot.</p

Expression of candidate MITF-A targets in E13.5 kidneys.

<p><b>A)</b><i>In situ</i> hybridization of <i>Bmp7</i>, <i>Pax2</i> and <i>Wnt9b</i> in wild-type (WT) and homozygous (HO) MITF-A transgenic kidneys at E13.5 (magnification X200, n = 5–6 per genotype). <b>B)</b> Quantitative RT-PCR analysis of <i>Bmp7</i>, <i>Pax2</i> and <i>Wnt9b</i> mRNA expression in E13.5 kidneys of WT, heterozygous (HE) and HO MITF-A transgenic embryos (n = 6–9 per genotype). <b>C)</b> <i>In situ</i> hybridization of <i>Re</i>t, <i>Wnt11</i> and <i>Spry1</i> in WT and HO MITF-A transgenic kidneys at E13.5 (magnification X200, n = 5–6 per genotype). Note the increased staining of <i>Re</i>t mRNA in transgenic kidneys at E13.5. <b>D)</b> Quantitative RT-PCR analysis of <i>Re</i>t, <i>Wnt11</i> and <i>Spry1</i> mRNA expression in E13.5 kidneys of WT, HE and HO MITF-A transgenic embryos (n = 6–9 per genotype). Data are means ± SEM. ANOVA followed by Tukey-Kramer test; transgenic <i>versus</i> wild-type mice: * P < 0.05, ** P < 0.01.</p