Efficacy of First-Line Chemotherapy in Patients with Advanced Lung Sarcomatoid Carcinoma

Background:Sarcomatoid carcinomas (SCs) are rare tumors that may arise in the lung, accounting for 0.4% of non–small-cell lung cancers; the prognosis is poor. Only few retrospective small-size series have studied the efficacy of chemotherapy (CT) for metastatic SC.Methods:Multicenter study of patients with advanced or metastatic SC who received first-line CT. Clinical characteristics at baseline, response to first-line CT (Response Evaluation Criteria in Solid Tumors version 1.1), progression-free survival (PFS), and overall survival (OS) were retrospectively collected.Results:Ninety-seven patients were included. Median age was 62 (54–72) years. The majority of patients were men (70%), white (84%), and smokers (84%). Overall, 73% of patients received first-line platinum-based CT. At first tumor evaluation, 69% of patients experienced progression, 31% had disease control, and 16.5% had partial response. Partial response was observed in 20% of patients receiving platinum-based CT, and in none of those receiving non–platinum-based CT (p = 0.018). Median PFS was 2.0 months (confidence interval [CI] 95%: 1.8–2.3). PFS was not statistically different between patients receiving or not receiving a platinum-based CT. Median OS was 6.3 months (CI 95%: 4.7–7.8). There was a trend toward better OS for patients treated with platinum-based CT (7.0 months [CI 95%: 4.9–9.0] versus 5.3 months [CI 95%: 2.8–7.6]; p = 0.096). In multivariate analysis, disease control at first evaluation (hazard ratio = 0.38 [CI 95%: 0.21–0.59]) and at platinum-based CT (hazard ratio = 0.92 [CI 95%: 0.85–0.99]) was associated with better OS.Conclusion:SC is associated with poor prognosis and high rate of resistance to conventional first-line CT. New therapeutic strategies are needed, based on better knowledge of the carcinogenesis of SC

Early T Cell Signalling Is Reversibly Altered in PD-1+ T Lymphocytes Infiltrating Human Tumors

To improve cancer immunotherapy, a better understanding of the weak efficiency of tumor-infiltrating T lymphocytes (TIL) is necessary. We have analyzed the functional state of human TIL immediately after resection of three types of tumors (NSCLC, melanoma and RCC). Several signalling pathways (calcium, phosphorylation of ERK and Akt) and cytokine secretion are affected to different extents in TIL, and show a partial spontaneous recovery within a few hours in culture. The global result is an anergy that is quite distinct from clonal anergy induced in vitro, and closer to adaptive tolerance in mice. PD-1 (programmed death -1) is systematically expressed by TIL and may contribute to their anergy by its mere expression, and not only when it interacts with its ligands PD-L1 or PD-L2, which are not expressed by every tumor. Indeed, the TCR-induced calcium and ERK responses were reduced in peripheral blood T cells transfected with PD-1. Inhibition by sodium stibogluconate of the SHP-1 and SHP-2 phosphatases that associate with several inhibitory receptors including PD-1, relieves part of the anergy apparent in TIL or in PD-1-transfected T cells. This work highlights some of the molecular modifications contributing to functional defects of human TIL

TWIST1 a New Determinant of Epithelial to Mesenchymal Transition in EGFR Mutated Lung Adenocarcinoma

Metastasis is a multistep process and the main cause of mortality in lung cancer patients. We previously showed that EGFR mutations were associated with a copy number gain at a locus encompassing the TWIST1 gene on chromosome 7. TWIST1 is a highly conserved developmental gene involved in embryogenesis that may be reactivated in cancers promoting both malignant conversion and cancer progression through an epithelial to mesenchymal transition (EMT). The aim of this study was to investigate the possible implication of TWIST1 reactivation on the acquisition of a mesenchymal phenotype in EGFR mutated lung cancer. We studied a series of consecutive lung adenocarcinoma from Caucasian non-smokers for which surgical frozen samples were available (n = 33) and showed that TWIST1 expression was linked to EGFR mutations (P<0.001), to low CDH1 expression (P<0.05) and low disease free survival (P = 0.044). To validate that TWIST1 is a driver of EMT in EGFR mutated lung cancer, we used five human lung cancer cell lines and demonstrated that EMT and the associated cell mobility were dependent upon TWIST1 expression in cells with EGFR mutation. Moreover a decrease of EGFR pathway stimulation through EGF retrieval or an inhibition of TWIST1 expression by small RNA technology reversed the phenomenon. Collectively, our in vivo and in vitro findings support that TWIST1 collaborates with the EGF pathway in promoting EMT in EGFR mutated lung adenocarcinoma and that large series of EGFR mutated lung cancer patients are needed to further define the prognostic role of TWIST1 reactivation in this subgroup

Modulation of Macrophage Activation State Protects Tissue from Necrosis during Critical Limb Ischemia in Thrombospondin-1-Deficient Mice

International audienceBACKGROUND: Macrophages, key regulators of healing/regeneration processes, strongly infiltrate ischemic tissues from patients suffering from critical limb ischemia (CLI). However pro-inflammatory markers correlate with disease progression and risk of amputation, suggesting that modulating macrophage activation state might be beneficial. We previously reported that thrombospondin-1 (TSP-1) is highly expressed in ischemic tissues during CLI in humans. TSP-1 is a matricellular protein that displays well-known angiostatic properties in cancer, and regulates inflammation in vivo and macrophages properties in vitro. We therefore sought to investigate its function in a mouse model of CLI. METHODS AND FINDINGS: Using a genetic model of tsp-1(-/-) mice subjected to femoral artery excision, we report that tsp-1(-/-) mice were clinically and histologically protected from necrosis compared to controls. Tissue protection was associated with increased postischemic angiogenesis and muscle regeneration. We next showed that macrophages present in ischemic tissues exhibited distinct phenotypes in tsp-1(-/-) and wt mice. A strong reduction of necrotic myofibers phagocytosis was observed in tsp-1(-/-) mice. We next demonstrated that phagocytosis of muscle cell debris is a potent pro-inflammatory signal for macrophages in vitro. Consistently with these findings, macrophages that infiltrated ischemic tissues exhibited a reduced postischemic pro-inflammatory activation state in tsp-1(-/-) mice, characterized by a reduced Ly-6C expression and a less pro-inflammatory cytokine expression profile. Finally, we showed that monocyte depletion reversed clinical and histological protection from necrosis observed in tsp-1(-/-) mice, thereby demonstrating that macrophages mediated tissue protection in these mice. CONCLUSION: This study defines targeting postischemic macrophage activation state as a new potential therapeutic approach to protect tissues from necrosis and promote tissue repair during CLI. Furthermore, our data suggest that phagocytosis plays a crucial role in promoting a deleterious intra-tissular pro-inflammatory macrophage activation state during critical injuries. Finally, our results describe TSP-1 as a new relevant physiological target during critical leg ischemia

Activités des élèves et pratiques des enseignants en classe de mathématiques.

International audienceCette brochure rassemble quelques chapitres en français d'un livre en cours d'édition anglaise chez Sense Publisher : "The mathematics classroom : students 'activities and teachers' practices". Ce livre est lui-même adapté du livre paru aux éditions Octarès en 2008 La classe de mathématiques : activités des élèves et pratiques des enseignants. Ce sont les chapitres du livre en français réécrits ou ajoutés pour la version anglaise. Chacun de ces deux ouvrages a pour objectif de regrouper des travaux en didactique des mathématiques, portant sur l'enseignement secondaire et supérieur, qui donnent une aussi grande importance aux acteurs (élèves et enseignants) qu'aux mathématiques et à la situation scolaire. Ces travaux s'inscrivent dans le cadre très général des théories de l'activité et du développement

Activités des élèves et pratiques des enseignants en classe de mathématiques.

International audienceCette brochure rassemble quelques chapitres en français d'un livre en cours d'édition anglaise chez Sense Publisher : "The mathematics classroom : students 'activities and teachers' practices". Ce livre est lui-même adapté du livre paru aux éditions Octarès en 2008 La classe de mathématiques : activités des élèves et pratiques des enseignants. Ce sont les chapitres du livre en français réécrits ou ajoutés pour la version anglaise. Chacun de ces deux ouvrages a pour objectif de regrouper des travaux en didactique des mathématiques, portant sur l'enseignement secondaire et supérieur, qui donnent une aussi grande importance aux acteurs (élèves et enseignants) qu'aux mathématiques et à la situation scolaire. Ces travaux s'inscrivent dans le cadre très général des théories de l'activité et du développement

Physiology of the lung in idiopathic pulmonary fibrosis

The clinical expression of idiopathic pulmonary fibrosis (IPF) is directly related to multiple alterations in lung function. These alterations derive from a complex disease process affecting all compartments of the lower respiratory system, from the conducting airways to the lung vasculature. In this article we review the profound alterations in lung mechanics (reduced lung compliance and lung volumes), pulmonary gas exchange (reduced diffusing capacity, increased dead space ventilation, chronic arterial hypoxaemia) and airway physiology (increased cough reflex and increased airway volume), as well as pulmonary haemodynamics related to IPF. The relative contribution of these alterations to exertional limitation and dyspnoea in IPF is discussed

The pro-apoptotic BAX protein influences cell growth and differentiation from the nucleus in healthy interphasic cells

International audienceIt has become more and more evident that the BCL-2 family proteins mediate a wide range of non-apoptotic functions. The pro-apoptotic BAX protein has been reported in interphasic nuclei. Whether the nuclear form of BAX could be involved in non-apoptotic function is still unknown. Our study showed for the first time that BAX was associated with chromatin in vitro. Next, we used gain and loss of function approaches to decipher the potential role of nuclear BAX in non-apoptotic cells. In vitro, nuclear BAX promoted cell proliferation in lung epithelial cells and primary human lung fibroblasts by modulating CDKN1A expression. Interestingly, BAX occupancy of CDKN1A promoter was specifically enriched close to the transcription-starting site. Nuclear BAX also modulated the basal myofibroblastic differentiation and migration of primary human lung fibroblasts. Finally, BAX nuclear localization was associated in vivo with the remodelling of lung parenchyma during development, tumorigenesis as well as fibrosis compared to control adult human lungs. Hence, our study established for the first time, a strong link between the nuclear localization of the pro-apoptotic BAX protein and key basic cellular functions in the non-apoptotic setting

Pseudomonas aeruginosa LasB protease impairs innate immunity in mice and humans by targeting a lung epithelial cystic fibrosis transmembrane regulator–IL-6–antimicrobial–repair pathway

Background Pseudomonas aeruginosa lung infections are a huge problem in ventilator-associated pneumonia, cystic fibrosis (CF) and in chronic obstructive pulmonary disease (COPD) exacerbations. This bacterium secretes virulence factors that may subvert host innate immunity.Objective We evaluated the effect of P. aeruginosa elastase LasB, an important virulence factor secreted by the type II secretion system, on ion transport, innate immune responses and epithelial repair, both in vitro and in vivo.Methods Wild-type (WT) or cystic fibrosis transmembrane conductance regulator (CFTR)-mutated epithelial cells (cell lines and primary cells from patients) were treated with WT or Delta LasB pseudomonas aeruginosa O1 (PAO1) secretomes. The effect of LasB and PAO1 infection was also assessed in vivo in murine models.Results We showed that LasB was the most abundant protein in WT PAO1 secretomes and that it decreased epithelial CFTR expression and activity. In airway epithelial cell lines and primary bronchial epithelial cells, LasB degraded the immune mediators interleukin (IL)-6 and trappin-2, an important epithelial-derived antimicrobial molecule. We further showed that an IL-6/STAT3 signalling pathway was downregulated by LasB, resulting in inhibition of epithelial cell repair. In mice, intranasally instillated LasB induced significant weight loss, inflammation, injury and death. By contrast, we showed that overexpression of IL-6 and trappin-2 protected mice against WT-PAO1-induced death, by upregulating IL-17/IL-22 antimicrobial and repair pathways.Conclusions Our data demonstrate that PAO1 LasB is a major P. aeruginosa secreted factor that modulates ion transport, immune response and tissue repair. Targeting this virulence factor or upregulating protective factors such as IL-6 or antimicrobial molecules such as trappin-2 could be beneficial in P. aeruginosa-infected individuals