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Background: Tocilizumab and anakinra are anti-interleukin drugs to treat severe coronavirus disease 2019 (COVID-19) refractory to corticosteroids. However, no studies compared the efficacy of tocilizumab versus anakinra to guide the choice of the therapy in clinical practice. We aimed to compare the outcomes of COVID-19 patients treated with tocilizumab or anakinra., Methods: Our retrospective study was conducted in three French university hospitals between February 2021 and February 2022 and included all the consecutive hospitalized patients with a laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection assessed by RT-PCR who were treated with tocilizumab or anakinra. A propensity score matching was performed to minimize confounding effects due to the non-random allocation., Results: Among 235 patients (mean age, 72 years; 60.9% of male patients), the 28-day mortality (29.4% vs. 31.2%, p = 0.76), the in-hospital mortality (31.7% vs. 33.0%, p = 0.83), the high-flow oxygen requirement (17.5% vs. 18.3%, p = 0.86), the intensive care unit admission rate (30.8% vs. 22.2%, p = 0.30), and the mechanical ventilation rate (15.4% vs. 11.1%, p = 0.50) were similar in patients receiving tocilizumab and those receiving anakinra. After propensity score matching, the 28-day mortality (29.1% vs. 30.4%, p = 1) and the rate of high-flow oxygen requirement (10.1% vs. 21.5%, p = 0.081) did not differ between patients receiving tocilizumab or anakinra. Secondary infection rates were similar between the tocilizumab and anakinra groups (6.3% vs. 9.2%, p = 0.44)., Conclusion: Our study showed comparable efficacy and safety profiles of tocilizumab and anakinra to treat severe COVID-19., Competing Interests: GK has received from ROCHE-CHUGAI Research Grants <€20,000 and fees from Sobi France for scientific presentations <€4,000 and participated in a SOBI Advisory Board on COVID unpaid and an OLATEC Monitoring Board unpaid. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Arcani, Correard, Suchon, Kaplanski, Jean, Cauchois, Leprince, Arcani, Seguier, De Sainte Marie, Andre, Koubi, Rossi, Gayet, Gobin, Garrido, Weiland, Jouve, Couderc, Villani and Daumas.)

Competing Interests: None declared.

During SARS-CoV-2 infection, eosinopenia may reflect a hyperactive immune response. In this study of hospitalized COVID-19 patients, we aimed to better understand the prognostic value of severe eosinopenia (absolute eosinophil count = 0 G/L) and decipher its underlying mechanisms. We retrospectively analyzed the records of COVID-19 patients hospitalized from March to June 2020 in three university hospitals in Marseille, France. We assessed the association between severe eosinopenia and a composite poor outcome in these patients, including the need for oxygen supplementation at >6 L/min, ICU admission, and in-hospital death. Among the 551 COVID-19 patients included in this study, severe eosinopenia was found in 228 (51%) of them on admission to hospital and was associated with a composite poor outcome using multivariate analysis (OR = 2.58; CI95 [1.77−3.75]; p < 0.0001). We found a significant association between the presence of severe eosinopenia on admission and the elevation in C-reactive protein, ferritin, IP-10, and suPAR. The histological findings in a series of 37 autopsies from patients who died from severe COVID-19 and presented with severe eosinopenia showed no pulmonary eosinophil trapping. Severe eosinopenia can be a reliable biomarker associated with a composite poor outcome in hospitalized COVID-19 adult patients. It may reflect the magnitude of immune hyperactivation during severe-to-critical COVID-19.

DNA methylation, a major biological process regulating the transcription, contributes to the pathophysiology of hematologic malignancies, and hypomethylating agents are commonly used to treat myelodysplastic syndromes (MDS) and acute myeloid leukemias (AML). In these diseases, bone marrow mesenchymal stromal cells (MSCs) play a key supportive role through the production of various signals and interactions. The DNA methylation status of MSCs, likely to reflect their functionality, might be relevant to understand their contribution to the pathophysiology of these diseases. Consequently, the aim of our study was to analyze the modifications of DNA methylation profiles of MSCs induced by MDS or AML. MSCs from MDS/AML patients were characterized via 5-methylcytosine quantification, gene expression profiles of key regulators of DNA methylation, identification of differentially methylated regions (DMRs) by methylome array, and quantification of DMR-coupled genes expression. MDS and AML-MSCs displayed global hypomethylation and under-expression of DNMT1 and UHRF1. Methylome analysis revealed aberrant methylation profiles in all MDS and in a subgroup of AML-MSCs. This aberrant methylation was preferentially found in the sequence of homeobox genes, especially from the HOX family (HOXA1, HOXA4, HOXA5, HOXA9, HOXA10, HOXA11, HOXB5, HOXC4, and HOXC6), and impacted on their expression. These results highlight modifications of DNA methylation in MDS/AML-MSCs, both at global and focal levels dysregulating the expression of HOX genes well known for their involvement in leukemogenesis. Such DNA methylation in MSCs could be the consequence of the malignant disease or could participate in its development through defective functionality or exosomal transfer of HOX transcription factors from MSCs to hematopoietic cells., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Dexamethasone has demonstrated efficacy in reducing mortality in COVID-19. However, its practical use is badly defined. We aimed to investigate factors associated with dexamethasone efficacy in real life. Our retrospective study was conducted in two university hospitals between September and November 2020 and included all the consecutive hospitalized patients with a laboratory-confirmed SARS-CoV-2 infection assessed by RT-PCR, treated with intravenous dexamethasone (6 mg/day). Among 111 patients, 10.6% necessitated a transfer into the intensive care unit (ICU) and the 28-day mortality rate was 17.1%. The 28-day mortality rate was significantly lower in patients who demonstrated improvement at 48 h (hazard ratio [HR]: 0.17, 95% confidence interval [CI]: 0.04-0.78, p = 0.02) and 96 h (HR: 0.07, 95% CI: 0.02-0.31, p = 0.0005) after dexamethasone initiation. Apart from well-known risk factors (age, hypertension, active cancer, severe lesions on chest computed tomography [CT] scan), we found that a high viral load in nasopharyngeal swab (Cycle threshold <30) at dexamethasone initiation was associated with higher 28-day mortality (66.6% vs. 36.7%, p = 0.03). Patients who did not receive antibiotics at dexamethasone initiation had a higher rate of transfer into the ICU (55.6% vs. 23.5%, p = 0.045) with a trend towards higher mortality in case of severe or critical lesions on CT scan (75.0% vs. 25.0%, p = 0.053). Patients who did not improve within 2-4 days after steroid initiation have a bad prognosis and should receive additional anti-inflammatory drugs. Our data suggest better efficacy of dexamethasone in patients with a low or negative viral load, receiving broad-spectrum antibiotics., (© 2022 Wiley Periodicals LLC.)

This study evaluates the impact of the French reform of 11 January 2008 in the private sector, which modified the share of sick leave paid by the employer in addition to the social security benefit. The reform is comprised of two parts: the waiting period until complementary payment is made by the employer, reduced from ten to seven days; and the minimum required tenure to be eligible, reduced from three years to one year. In this study, we use the administrative panel data (Hygie) from 2006 to 2010 along with a new collective bargaining agreement (CBA) database. The latter was constructed by the authors in order to collect the parameters of complementary benefits for sick leave. We examined separately the effects of the waiting period part and the tenure part of the reform, using a difference-in-differences strategy with matching. When the waiting period is reduced, the number of sick days' increase significantly (+ 0.5 days). When the minimum tenure requirement is reduced, there is more impact on sick leave (+ 0.6 days on the number of sick days and + 0.9 pp on sickness probability). The effects of sick pay reform are different between men and women., Competing Interests: Declaration of Competing Interest None., (Copyright © 2022. Published by Elsevier B.V.)

Adverses pregnancy outcomes are commonly encountered with autoimmune disease (AID). Although anti-nuclear antibodies (ANA) are often present several years before AID diagnosis, the importance of ANA testing has not been evaluated in this context. The objective of this study was to determine if ANA discovery after obstetrical complications is associated with a diagnosis of AID and improves the prognosis of subsequent pregnancies. All patients presented at the multidisciplinary board meeting (MBM) "Thrombophilia and Pregnancy", whose ANA were discovered after an obstetrical complication, were included in a multicenter descriptive study. All patients were referred to an internal medicine consultation for diagnosis. Data were collected retrospectively by computer chart analysis and updated by phone. A total of 404 patients were included, of which 50 (12.4 %) had a diagnosis of AID related to ANA. Patients with AID had higher ANA levels (p < 0.001), with more frequent specificity (26%, versus 6.7%, p < 0.0001), and more often persistent (84% versus 30.8%, p < 0.0001) compared to patients without AID. Subsequent pregnancy outcomes were not significantly affected by ANA levels and AID diagnoses. Our study shows that the discovery of ANA after obstetrical complications may lead to an early diagnosis of AID. It makes us reconsider the systematic determination of ANA after an obstetrical event because in the case where ANA are found positive, an adapted follow-up would reduce the negative impact of ANA presence on subsequent pregnancies., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Specificities of COVID-19 disease course in patients with haematologic malignancies are still poorly studied. So, we aimed to compare patients with haematologic malignancies to patients without malignancies, matched by sex and age and hospitalised for COVID-19 at the same time and in the same centre. Among 25 patients with haematologic malignancies, we found that mortality (40% versus 4%, p < 0.01), number of days with RT-PCR positivity (21.2 ± 15.9 days [range, 3-57] versus 7.4 ± 5.6 days [range, 1-24], p < 0.01), maximal viral load (mean minimal Ct, 17.2 ± 5.2 [range, 10-30] versus 26.5 ± 5.1 [range, 15-33], p < 0.0001) and the delay between symptom onset and clinical worsening (mean time duration between symptom onset and first day of maximum requirement in inspired oxygen fraction, 14.3 ± 10.7 days versus 9.6 ± 3.7 days, p = 0.0485) were higher than in other patients. COVID-19 course in patients with haematologic malignancies has a delayed onset and is more severe with a higher mortality, and patients may be considered as super-spreaders. Clinicians and intensivists need to be trained to understand the specificity of COVID-19 courses in patients with haematological malignancies., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Attention Deficit Hyperactive Disorder (ADHD) is a common neurobehavioral disorder with a significant and pervasive impact on patients' lives. Identifying neurophysiological correlates of ADHD is important for understanding its underlying mechanisms, as well as for improving clinical accuracy beyond cognitive and emotional factors. The present study focuses on finding a diagnostic stable neural correlate based on evaluating MEG resting state frequency bands. Twenty-two ADHD patients and 23 controls adults were blindly randomized to two methylphenidate/placebo evaluation days. On each evaluation day state anxiety was assessed, a 2N-back executive function task was performed, and resting state MEG brain activity was recorded at three timepoints. A frequency-based cluster analysis yielded higher high-gamma power for ADHD over posterior sensors and lower high-gamma power for ADHD over frontal-central sensors. These results were shown to be stable over three measurements, unaffected by methylphenidate treatment, and linked to cognitive accuracy and state anxiety. Furthermore, the differential high-gamma activity evidenced substantial ADHD diagnostic efficacy, comparable to the cognitive and emotional factors. These results indicate that resting state high-gamma activity is a promising, stable, valid and diagnostically-relevant neurocorrelate of ADHD. Due to the evolving understanding both in the cellular and network level of high-gamma oscillations, focusing future studies on this frequency band bears the potential for a better understanding of ADHD, thus advancing the specificity of the evaluation of the disorder and developing new tools for therapy., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background and Aims: Few studies distinguished the independent role of overweight/obesity or their associated-comorbidities in the evolution towards severe forms of COVID-19. Obesity as a unifying risk factor for severe COVID-19 is an emerging hypothesis. The aim of this study was to evaluate whether excessive body weight per se, was a risk factor for developing a severe form of COVID-19., Patients and Methods: We included 131 patients hospitalized for COVID-19 pneumonia in a single center of the internal medicine department in Marseille, France. We recorded anthropometric and metabolic parameters such as fasting glycaemia, insulinemia, HOMA-IR, lipids, and all clinical criteria linked to SARS-CoV-2 infection at the admission. Excess body weight was defined by a BMI ≥ 25 kg/m 2 . The occurrence of a serious event was defined as a high-debit oxygen requirement over 6 L/min, admission into the intensive care unit, or death., Results: Among 113 patients, two thirds (n = 76, 67%) had an excess body weight. The number of serious events was significantly higher in excess body weight patients compared to normal weight patients (respectively 25% vs 8%, p = 0.03) although excess body weight patients were younger (respectively 63.6 vs 70.3 years old, p = 0.01). In multivariate analyses, the excess body weight status was the only predictor for developing a serious event linked to SARS-CoV-2 infection, with an odds ratio at 5.6 (95% CI: 1.30-23.96; p = 0.02), independently of previous obesity associated comorbidities. There was a trend towards a positive association between the BMI (normal weight, overweight and obesity) and the risk of serious events linked to COVID-19, with a marked increase from 8.1% to 20% and 30.6% respectively (p = 0.05)., Conclusion: Excess body weight was significantly associated with severe forms of the disease, independently of its classical associated comorbidities. Physicians and specialists in Public Health must be sensitized to better protect people with an excess body weight against SARS-CoV-2 infection., Competing Interests: Declaration of competing interest LP, RG, AB, ML, MK, RC, RG, ND, GK, RV and SB have no conflicts of interest linked to this work., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Beside the commonly described pulmonary expression of the coronavirus disease 2019 (COVID-19), major vascular events have been reported. The objective of this study was to investigate whether increased levels of circulating endothelial cells (CECs) might be associated with severe forms of COVID-19. Ninety-nine patients with COVID-19 were enrolled in this retrospective study. Patients in the intensive care units (ICU) had significantly higher CEC counts than non-ICU patients and the extent of endothelial injury was correlated with putative markers of disease severity and inflammatory cytokines. Together, these data provide in vivo evidence that endothelial injury is a key feature of COVID-19., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Around the tenth day after diagnosis, ∼20% of patients with coronavirus disease 2019 (COVID-19)-associated pneumonia evolve toward severe oxygen dependence (stage 2b) and acute respiratory distress syndrome (stage 3) associated with systemic inflammation often termed a "cytokine storm." Because interleukin-1 (IL-1) blocks the production of IL-6 and other proinflammatory cytokines, we treated COVID-19 patients early in the disease with the IL-1 receptor antagonist, anakinra. We retrospectively compared 22 patients from three different centers in France with stages 2b and 3 COVID-19-associated pneumonia presenting with acute severe respiratory failure and systemic inflammation who received either standard-of-care treatment alone (10 patients) or combined with intravenous anakinra (12 patients). Treatment started at 300 mg⋅d -1 for 5 d, then tapered with lower dosing over 3 d. Both populations were comparable for age, comorbidities, clinical stage, and elevated biomarkers of systemic inflammation. All of the patients treated with anakinra improved clinically ( P < 0.01), with no deaths, significant decreases in oxygen requirements ( P < 0.05), and more days without invasive mechanical ventilation ( P < 0.06), compared with the control group. The effect of anakinra was rapid, as judged by significant decrease of fever and C-reactive protein at day 3. A mean total dose of 1,950 mg was infused with no adverse side effects or bacterial infection. We conclude that early blockade of the IL-1 receptor is therapeutic in acute hyperinflammatory respiratory failure in COVID-19 patients., Competing Interests: The authors declare no competing interest., (Copyright © 2020 the Author(s). Published by PNAS.)

Iron deficiency, without anaemia, is common in the general population and induces various symptoms. Its management consists of oral and intravenous supplementation for cases of inefficacy of or intolerance to oral iron. We assessed the efficacy of intravenous iron therapy in non-anaemic iron-deficient patients with fatigue. We prospectively evaluated the level of fatigue, using the Fatigue Severity Scale (FSS), in patients suffering from iron deficiency without anaemia, treated by intravenous iron at the moment of the perfusion (W0), after 4 weeks (W4), and 12 weeks (W12). Of 25 patients, at W0, the mean FFS was 49.3+/-13.7. There was a significant improvement in FSS at W4 (44+/-15; p = 0.01) and a sustained response at W12 with an FFS of 35.8+/-17.1 (p < 0,0001). There was no correlation between FSS and serum ferritin level at W12 (p=0.54) or between serum ferritin at W12 and difference between FSS at W0 and W12 (p=0.58). There were six mild adverse events (24%): asthenia (8%), nausea (8%), headache (4%), local pain (4%); and no serious adverse events. Our results suggest the rapid efficacy of intravenous iron in improving fatigue in iron deficiency without anaemia with a good profile of tolerance.

Introduction: Non-adherence to efficacious pharmacotherapy is a major obstacle in the treatment of children suffering from attention deficit hyperactive disorder (ADHD). Some hold the position that pharmacotherapy induces anxiety, and that this is one of the reasons for this non-adherence. Previous studies have pointed to the opposite, a moderating effect of methylphenidate (MPH) on state anxiety in patients with ADHD. This has been shown in continuous treatment in children, but not on a single dose. We hypothesized that a single dose might have a different effect. Method: Twenty children with ADHD were given single doses of MPH in a randomized, controlled, crossover, double blind study. State anxiety using The Spielberger State-Trait Anxiety Inventory (STAI) and a continuous performance test were assessed. Results: As a group, no change was detected in state anxiety with MPH or placebo. However, children who were given MPH during the first session as opposed to those who received placebo first, demonstrated deterioration in baseline state anxiety in the second session [ t (2.485) , p < 0.05]. Conclusion: Our findings show a possible delayed anxiety-provoking effect of a single dose of MPH. This may be relevant to the understanding of difficulties in adherence with MPH treatment in children with ADHD. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT01798459.

Objectives: Recent studies support the possible effectiveness of repetitive transcranial magnetic stimulation (rTMS) as a treatment for attention deficit hyperactivity disorder (ADHD). The objective of this study was to evaluate the safety and possible efficacy of bilateral prefrontal deep rTMS for the treatment of adult ADHD., Methods: Twenty-six adult ADHD patients were randomised blindly to sham or actual deep TMS (dTMS). Twenty daily sessions were conducted using the bilateral H5 dTMS coil (Brainsway, IL) in order to stimulate the prefrontal cortex at 120% of the motor threshold at high frequency. For assessment, Conners' Adult ADHD Rating Scale questionnaire and a computerised continuous performance test, Test of Variables of Attention, were used., Results: No differences in clinical outcomes were detected between the actual dTMS and sham groups., Conclusions: The presented evidence does not support the utility of bilateral prefrontal stimulation to treat adult ADHD. Due to the small sample size, caution must be exercised in interpreting our preliminary findings.

The transcription factor PLZF (promyelocytic leukemia zinc finger protein) acts as an epigenetic regulator balancing self-renewal and differentiation of hematopoietic cells through binding to various chromatin-modifying factors. First described as a transcriptional repressor, PLZF is also associated with active transcription, although the molecular bases underlying the differences are unknown. Here, we reveal that in a hematopoietic cell line, PLZF is predominantly associated with transcribed genes. Additionally, we identify a new association between PLZF and the histone methyltransferase, EZH2 at the genomic level. We find that co-occupancy of PLZF and EZH2 on chromatin at PLZF target genes is not associated with SUZ12 or trimethylated lysine 27 of histone H3 (H3K27me3) but with the active histone mark H3K4me3 and active transcription. Removal of EZH2 leads to an increase of PLZF binding and increased gene expression. Our results suggest a new role of EZH2 in restricting PLZF positive transcriptional activity independently of its canonical PRC2 activity.

Objectives: There is an increasing awareness of the importance of patients' subjective evaluations of therapy. Regarding electroconvulsive therapy (ECT), the results are conflicting. We hypothesized that making a comparison between patients' satisfaction with ECT and other forms of psychiatric therapies would capture personal experience as opposed to opinion about the treatment modalities. We compared adult responses to adolescent responses., Methods: Four unmatched patient groups were recruited (N = 98) and were divided as follows: (a) patients treated with ECT as adolescents (n = 13), (b) patients treated with ECT as adults (n = 25), (c) patients hospitalized as adolescents but not treated with ECT (n = 30), and (d) patients hospitalized as adults but not treated with ECT (n = 30). All patients were interviewed using similar questions related to their satisfaction regarding the treatment modalities they experienced, including psychotherapy, pharmacotherapy, hospitalization and ECT, and years after being treated., Results: Adults and adolescents viewed ECT as a legitimate and effective form of treatment (70%). Patients who were treated with ECT had a more positive attitude toward this treatment compared with patients who had not been treated with ECT. In comparison to other treatment modalities, ECT was considered by both adolescents and adults as the least effective form of therapy. Psychotherapy was considered the most effective, specifically among adolescents., Conclusions: Comparing patients' satisfaction in regard to different therapeutic modalities can potentially help clarify discrepancies in patient reports on satisfaction with ECT. Patients' satisfaction with ECT, just like their clinical response to ECT, is more dichotomous than with other forms of therapy.

Polycomb Group proteins (PcG) are repressive epigenetic factors essential for development and involved in numerous cancer processes, yet their modes of action and recruitment to specific genomic loci are not fully understood. Recently, it has been shown that the PcG protein recruitment is a dynamic process, contrary to what was foreseen in the initial hierarchical model. In addition, EZH2, a key PcG protein, can be associated to transcribed genes, challenging the former function of PcG proteins as transcriptional repressors. Furthermore, the dual role of EZH2, which can act as an oncogene or a tumor suppressor depending on the cellular type, illustrates the functional complexity of PcG proteins., (© 2017 médecine/sciences – Inserm.)

Hematopoietic stem cells (HSCs) give rise to all blood populations due to their long-term self-renewal and multipotent differentiation capacities. Because they have to persist throughout an organism's life span, HSCs tightly regulate the balance between proliferation and quiescence. Here, we investigated the role of the transcription factor promyelocytic leukemia zinc finger (plzf) in HSC fate using the Zbtb16(lu/lu)mouse model, which harbors a natural spontaneous mutation that inactivates plzf. Regenerative stress revealed that Zbtb16(lu/lu)HSCs had a lineage-skewing potential from lymphopoiesis toward myelopoiesis, an increase in the long-term-HSC pool, and a decreased repopulation potential. Furthermore, oldplzf-mutant HSCs present an amplified aging phenotype, suggesting that plzf controls age-related pathway. We found that Zbtb16(lu/lu)HSCs harbor a transcriptional signature associated with a loss of stemness and cell cycle deregulation. Lastly, cell cycle analyses revealed an important role for plzf in the regulation of the G1-S transition of HSCs. Our study reveals a new role for plzf in regulating HSC function that is linked to cell cycle regulation, and positions plzf as a key player in controlling HSC homeostasis., (© 2016 by The American Society of Hematology.)

T-cell acute lymphoblastic leukaemias (T-ALL) are aggressive malignant proliferations characterized by high relapse rates and great genetic heterogeneity. TAL1 is amongst the most frequently deregulated oncogenes. Yet, over half of the TAL1(+) cases lack TAL1 lesions, suggesting unrecognized (epi)genetic deregulation mechanisms. Here we show that TAL1 is normally silenced in the T-cell lineage, and that the polycomb H3K27me3-repressive mark is focally diminished in TAL1(+) T-ALLs. Sequencing reveals that >20% of monoallelic TAL1(+) patients without previously known alterations display microinsertions or RAG1/2-mediated episomal reintegration in a single site 5' to TAL1. Using 'allelic-ChIP' and CrispR assays, we demonstrate that such insertions induce a selective switch from H3K27me3 to H3K27ac at the inserted but not the germline allele. We also show that, despite a considerable mechanistic diversity, the mode of oncogenic TAL1 activation, rather than expression levels, impact on clinical outcome. Altogether, these studies establish site-specific epigenetic desilencing as a mechanism of oncogenic activation.

Background: Metastasis is an important step in tumor progression leading to a disseminated and often incurable disease. First steps of metastasis include down-regulation of cell adhesion molecules, alteration of cell polarity and reorganization of cytoskeleton, modifications associated with enhanced migratory properties and resistance of tumor cells to anoikis. Such modifications resemble Epithelial to Mesenchymal Transition (EMT). In breast cancer CD146 expression is associated with poor prognosis and enhanced motility., Methodology/principal Findings: On 4 different human breast cancer cell lines, we modified CD146 expression either with shRNA technology in CD146 positive cells or with stable transfection of CD146 in negative cells. Modifications in morphology, growth and migration were evaluated. Using Q-RT-PCR, we analyzed the expression of different EMT markers. We demonstrate that high levels of CD146 are associated with loss of cell-cell contacts, expression of EMT markers, increased cell motility and increased resistance to doxorubicin or docetaxel. Experimental modulation of CD146 expression induces changes consistent with the above described characteristics: morphology, motility, growth in anchorage independent conditions and Slug mRNA variations are strictly correlated with CD146 expression. These changes are associated with modifications of ER (estrogen receptor) and Erb receptors and are enhanced by simultaneous and opposite modulation of JAM-A, or exposure to heregulin, an erb-B4 ligand., Conclusions: CD146 expression is associated with an EMT phenotype. Several molecules are affected by CD146 expression: direct or indirect signaling contributes to EMT by increasing Slug expression. CD146 may also interact with Erb signaling by modifying cell surface expression of ErbB3 and ErbB4 and increased resistance to chemotherapy. Antagonistic effects of JAM-A, a tight junction-associated protein, on CD146 promigratory effects underline the complexity of the adhesion molecules network in tumor cell migration and metastasis.