Human papillomavirus E6/E7 oncoproteins promote radiotherapy-mediated tumor suppression by globally hijacking host DNA damage repair

Rationale: Whatever the mucosa primary infected, HPV-positive cancers are traditionally associated with a favorable outcome, attributable to a high sensitivity to radiation therapy. However, the direct impact of viral E6/E7 oncoproteins on the intrinsic cellular radiosensitivity (and, globally, on host DNA repair) remains mostly speculative. Methods: Using several isogenic cell models expressing HPV16 E6 and/or E7, the effect of viral oncoproteins on global DNA damage response was first investigated by in vitro/in vivo approaches. The binary interactome of each individual HPV oncoprotein with factors involved in the various host DNA damage/repair mechanisms was then precisely mapped by Gaussia princeps luciferase complementation assay (and validated by co-immunoprecipitation). The stability/half-life of protein targets for HPV E6 and/or E7 as well as their subcellular localizations were determined. At last, the host genome integrity following E6/E7 expression and the synergy between radiotherapy and compounds targeting DNA repair were analyzed. Results: We first showed that the sole expression of one viral oncoprotein from HPV16 was able to significantly increase the sensitivity to irradiation of cells without affecting their basal viability parameters. In total, 10 novel targets (CHEK2, CLK2, CLK2/3, ERCC3, MNAT1, PER1, RMI1, RPA1, UVSSA and XRCC6) for E6 and 11 (ALKBH2, CHEK2, DNA2, DUT, ENDOV, ERCC3, PARP3, PMS1, PNKP, POLDIP2 and RBBP8) for E7 were identified. Importantly, not degraded following their interaction with E6 or E7, these proteins have been shown to be less linked to host DNA and to colocalize with HPV replication foci, denoting their crucial implication in viral life cycle. Finally, we found that E6/E7 oncoproteins globally jeopardize host genome integrity, increase the cellular sensitivity to DNA repair inhibitors and enhance their synergy with radiotherapy. Conclusion: Taken together, our findings provide a molecular insight into the direct hijacking of host DNA damage/repair responses by HPV oncoproteins, demonstrate the significant impact of this phenomenon on both intrinsic cellular radiosensitivity and host DNA integrity and suggest novel connected therapeutic vulnerabilities.

Acute and chronic changes in LV performance in patients with primary severe mitral regurgitation undergoing percutaneous mitral valve repair

Background

The non-invasive assessment of myocardial work allows to evaluate LV performance by taking into account the effect of LV load. Aim of this study was to evaluate the acute and chronic impact of percutaneous mitral valve repair (PMVR) on LV performance, in patients with severe primary mitral regurgitation (PMR).

Methods

71 patients (age: 77±9 years, females: 44%) with severe PMR (effective regurgitant orifice: 0.57±0.31 cm2, regurgitant volume: 80±34 ml) and preserved LV ejection fraction (LVEF: 60±10%) underwent PMVR according to current recommendations. Myocardial work indices were evaluated before the procedure, 2 days after the procedure and at 1-year follow-up.

Results

PMVR was associated with an acute reduction in LVEF, global longitudinal strain (GLS), myocardial work index (MWI), and work efficiency (MWE), and a significant increase in myocardial wasted work (MWW) and mechanical dispersion (MD). 1-year after the procedure, LV size significantly decreased, GLS, MWI, MWE and MD improved, whereas GWW remained significantly reduced. LVEF improved but remained significantly altered compared with baseline values (Table 1).

Conclusions

In patients severe PMR undergoing PMVR, the acute reduction in LV preload causes a significant impairment of all parameters of LV performance. After 1-year, progressive LV remodeling is associated a significant improvement in MCW, counterbalanced by a persistently high MWW, which can explain the partial recovery of LVEF.

Funding Acknowledgement

Type of funding sources: None.

Left atrial reservoir strain is an independent prognostic predictor in patients undergoing percutaneous mitral valve repair

Background

Left atrial reservoir strain (LARS) is a well known prognostic predictor in several cardiac disease. Aim of the study was to assess the value of LARS in predicting the occurrence of major adverse cardiovascular events in patients undergoing percutaneous mitral valve repair (PMVR)

Methods and results

112 patients (62 males, mean age 74 years) undergoing PMVR for severe primary (n=71, 63%) or secondary MR were retrospectively included in the study. All patients underwent a comprehensive echocardiography before the procedure. Thirty-eight MACES occurred during a median follow up of 18 months. At multivariable Cox regression analysis, ischemic cardiomyopathy (CAD) [HR: 2.41 (1.11–5.24) p=0.02], indexed left atrial volume (LAVi) [HR: 1.01 (1.00–1.01) p=0 03] and LARS [HR: 0.93, (0.88–0.99) p=0.03] were all significant predictors of MACEs (Table 1). A cut-off of 13 for LARS (AUC 0 66 p=0.008 was able to predict MACEs with a 71% sensitivity and 41% specificity (Figure 1A). At Kaplan Meier analysis a PLAS <13% was associated with a worse prognosis (Log rank p=0.01) (Figure 1B).

Conclusions

LARS is an independent predictor of MACEs in patients undergoing percutaneous mitral valve repair, independently of the etiology of mitral regurgitation.

Funding Acknowledgement

Type of funding sources: None.

HPV infection alters vaginal microbiome through down-regulating host mucosal innate peptides used by Lactobacilli as amino acid sources

Despite the high prevalence of both cervico-vaginal human papillomavirus (HPV) infection and bacterial vaginosis (BV) worldwide, their causal relationship remains unclear. While BV has been presumed to be a risk factor for HPV acquisition and related carcinogenesis for a long time, here, supported by both a large retrospective follow-up study (n = 6,085) and extensive in vivo data using the K14-HPV16 transgenic mouse model, we report a novel blueprint in which the opposite association also exists. Mechanistically, by interacting with several core members (NEMO, CK1 and β-TrCP) of both NF-κB and Wnt/β-catenin signaling pathways, we show that HPV E7 oncoprotein greatly inhibits host defense peptide expression. Physiologically secreted by the squamous mucosa lining the lower female genital tract, we demonstrate that some of these latter are fundamental factors governing host-microbial interactions. More specifically, several innate molecules down-regulated in case of HPV infection are hydrolyzed, internalized and used by the predominant Lactobacillus species as amino acid source sustaining their growth/survival. Collectively, this study reveals a new viral immune evasion strategy which, by its persistent/negative impact on lactic acid bacteria, ultimately causes the dysbiosis of vaginal microbiota.

Acute and chronic changes in LV performance in patients with primary severe mitral regurgitation undergoing percutaneous mitral valve repair

Funding Acknowledgements

Type of funding sources: None.

Background

The non-invasive assessment of myocardial work allow to evaluate LV performance by taking into account the effect of LV load. Aim of this study is to evaluate the acute and chronic impact of percutaneous mitral valve repair (PMVR) on left ventricular (LV) performance, in patients with severe primary mitral regurgitation (PMR).

Methods and Results

71 patients (age: 77 ± 9 years, females: 44%) with severe PMR (effective regurgitant orifice: 0.57 ± 0.31 cm2, regurgitant volume: 80 ± 34 ml) and preserved LV ejection fraction (LVEF: 60 ± 10%) underwent PMVR according to current recommendations. Myocardial work indices were evaluated before the procedure, 2 days after the procedure and at 1-year follow-up.  PMVR was associated with an acute reduction in LVEF, global longitudinal strain (GLS), myocardial work index (MWI), and work efficiency (MWE), and a significant increase in myocardial wasted work (MWW) and mechanical dispersion (MD). 1-year after the procedure, LV size significantly decreased, GLS, MWI, MWE and MD improved, whereas GWW remained significantly reduced. LVEF improved but remained significantly altered compared with baseline values (Table 1).

Conclusions

In patients severe PMR undergoing PMVR, the acute reduction in LV preload causes a significant impairment of all parameters of LV performance. After 1-year, progressive LV remodeling is associated a significant improvement in MCW, counterbalanced by a persistently high MWW, which can explain the partial recovery of LVEF. Abstract Figure.

Left atrial reservoir strain is an independent prognostic predictor in patients undergoing percutaneous mitral valve repair

Funding Acknowledgements

Type of funding sources: None.

Background

Left atrial reservoir strain (LARS) is a well-known prognostic predictor in several cardiac diseases. Aim of the presence study was to assess the value of LARS in predicting the occurrence of major adverse cardiovascular events (MACEs) in patients undergoing percutaneous mitral valve repair (PMVR)

Methods and results

112 patients (62% males, age: 74 ± 10 years) undergoing PMVR for severe primary (n = 71, 63%) or secondary MR were retrospectively included in the study underwent a comprehensive echocardiography before the procedure. Thirty-eight MACES occurred during a median follow-up of 18 months. At multivariable Cox-regression analysis, ischemic cardiomyopathy [HR 2.41 (1.11-5.24, p = 0.02)], indexed left atrial volume [HR 1.01 (1.00-1.01), p = 0.03], and LARS [HR 0.93 (0.88-0.99), p = 0.03] were all significant predictors of MACEs. A cut-off of 13% for LARS (AUC 0.66, p = 0.008) was able to predict MACEs with a 71% sensitivity and 41% specificity (Table 1).

Conclusions

LARS is an independent predictor of MACEs in patients undergoing percutaneous mitral valve repair, independently of the etiology of mitral regurgitation. Abstract Figure.

Acute and chronic changes in LV performance in patients with secondary severe mitral regurgitation undergoing percutaneous mitral valve repair

Funding Acknowledgements

Type of funding sources: None.

Background

The non-invasive assessment of myocardial work allows to evaluate left ventricular (LV) performance by considering the effect of LV load on LV deformation. Aim of this study is to evaluate the acute and chronic impact of percutaneous mitral valve repair (PMVR) on LV function, in patients with severe secondary mitral regurgitation (SMR).

Methods and Results

41 patients (age: 69 ± 10 years, females: 29%) with severe SMR (effective regurgitant orifice: 0.42 ± 0.16 cm2, regurgitant volume: 65 ± 325 ml) underwent PMVR according to current recommendations. Myocardial work indices were evaluated before the procedure, 2 days after the procedure and at 1-year follow-up.  PMVR was associated with an acute reduction in LV ejection fraction (LVEF), global longitudinal strain (GLS), and myocardial constructive work (MCW) and with a significant increase in myocardial wasted work (MWW). 1-year after the procedure, we did not observe significant LV reverse remodeling. GWE remained significantly impaired despite the small improvement in GCW, which can explain the absence of improvement in MWE and GLS. Interestingly, LVEF modestly increased compared with the post-procedural values, but remained significantly reduced compared to baseline values (Table1).

Conclusions

In patients severe SMR undergoing PMVR, the acute reduction in LV preload causes a significant impairment of all parameters of LV performance. After 1-year, the absence of LV reverse remodelling is associated a significant impairment in GWW, without substantial improvement in the remaining parameters of LV function. Abstract Figure.

Cancer immunotherapy: it's time to better predict patients' response

In less than a decade, half a dozen immune checkpoint inhibitors have been approved and are currently revolutionising the treatment of many cancer (sub)types. With the clinical evaluation of novel delivery approaches (e.g. oncolytic viruses, cancer vaccines, natural killer cell-mediated cytotoxicity) and combination therapies (e.g. chemo/radio-immunotherapy) as well as the emergence of novel promising targets (e.g. TIGIT, LAG-3, TIM-3), the 'immunotherapy tsunami' is not about to end anytime soon. However, this enthusiasm in the field is somewhat tempered by both the relatively low percentage (<15%) of patients who display an effective anti-cancer immune response and the inability to accurately identify them. Recently, several existing or acquired features/parameters have been shown to impact the efficacy of immune checkpoint inhibitors. In the present review, we critically discuss current knowledge regarding predictive biomarkers for checkpoint inhibitor-based immunotherapy, highlight the missing/unclear links and emphasise the importance of characterising each neoplasm and its microenvironment in order to better guide the course of treatment.

Humeral metastasis as the only recurrence of a 5-year resected gastrointestinal stromal tumor: a case report

INTRODUCTION

Gastrointestinal stromal tumors represent the most frequently encountered primary mesenchymal tumors. Whereas the liver and the peritoneum are known to be the preferential metastasis sites, no therapeutic standard has yet been established for the management of bone metastases because of their very low incidence. We report a unique example of a single humerus metastasis of a jejunal gastrointestinal stromal tumor.

CASE PRESENTATION

We report the case of a 72-year-old European woman whose jejunal gastrointestinal stromal tumor was resected in 2013 and treated during the following 3 years with imatinib (400 mg daily). In 2018, she developed a single humeral bone lesion that was identified as a gastrointestinal stromal tumor metastasis. After 7 months of imatinib intake, reconstructive surgery was performed. Pathologists confirmed the satisfactory histological regression and assessed the complete tumor resection. The patient is still on imatinib maintenance therapy, with no recurrence reported so far. She fully recovered the upper limb function after following an appropriate rehabilitation program.

DISCUSSION

Current literature and published case reports indicate that bones are one of the rarest locations of gastrointestinal stromal tumor metastasis (about 1%), with occurrence mainly in the spine. Patients initially diagnosed with gastrointestinal stromal tumor of the small intestine and stomach are more likely to suffer from bone metastasis, compared with other gastrointestinal stromal tumor locations. The median overall survival rate is higher for patients with isolated bone metastasis compared with those having liver metastasis. Metastasis occurs on average 4 years after the primary, but it may take up to 20 years, emphasizing the need for long-term clinical and radiological monitoring. Although specific guidelines for such cases have not yet been established, we suggest that a multimodal concerted approach involving surgery or radiotherapy associated with tyrosine kinase inhibitor intake should be considered.

CONCLUSION

Bones are one of the rarest locations of gastrointestinal stromal tumor metastasis. A multidisciplinary collaboration was set up to allow conservative surgery of our patient after several months of imatinib treatment. A year and a half later, the patient is still in complete remission. This specific case supports the concept of an intermediate stage between local and oligometastatic disease that should be managed with a curative aim, as much as possible.

Withholding and withdrawing treatment in pediatric intensive care. Update of the GFRUP recommendations

In 2005, the French-speaking task force on pediatric critical and emergency care [Groupe Francophone de Réanimation et d'Urgences Pédiatriques (GFRUP)] issued recommendations on withholding and withdrawing treatments in pediatric critical care. Since then, the French Public Health Code, modified by the laws passed in 2005 and 2016 and by their enactment decrees, has established a legal framework for practice. Now, 15 years later, an update of these recommendations was needed to factor in the experience acquired by healthcare teams, new questions raised by practice surveys, the recommendations issued in the interval, the changes in legislation, and a few legal precedents. The objective of this article is to help pediatric critical care teams find the closest possible compromise between the ethical principles guiding the care offered to the child and the family and compliance with current regulations and laws.

Extracellular HMGB1 blockade inhibits tumor growth through profoundly remodeling immune microenvironment and enhances checkpoint inhibitor-based immunotherapy

Background

High-mobility group box 1 (HMGB1) is a multifunctional redox-sensitive protein involved in various intracellular (eg, chromatin remodeling, transcription, autophagy) and extracellular (inflammation, autoimmunity) processes. Regarding its role in cancer development/progression, paradoxical results exist in the literature and it is still unclear whether HMGB1 mainly acts as an oncogene or a tumor suppressor.

Methods

HMGB1 expression was first assessed in tissue specimens (n=359) of invasive breast, lung and cervical cancer and the two distinct staining patterns detected (nuclear vs cytoplasmic) were correlated to the secretion profile of malignant cells, patient outcomes and the presence of infiltrating immune cells within tumor microenvironment. Using several orthotopic, syngeneic mouse models of basal-like breast (4T1, 67NR and EpRas) or non-small cell lung (TC-1) cancer, the efficacy of several HMGB1 inhibitors alone and in combination with immune checkpoint blockade antibodies (anti-PD-1/PD-L1) was then investigated. Isolated from retrieved tumors, 14 immune cell (sub)populations as well as the activation status of antigen-presenting cells were extensively analyzed in each condition. Finally, the redox state of HMGB1 in tumor-extruded fluids and the influence of different forms (oxidized, reduced or disulfide) on both dendritic cell (DC) and plasmacytoid DC (pDC) activation were determined.

Results

Associated with an unfavorable prognosis in human patients, we clearly demonstrated that targeting extracellular HMGB1 elicits a profound remodeling of tumor immune microenvironment for efficient cancer therapy. Indeed, without affecting the global number of (CD45⁺) immune cells, drastic reductions of monocytic/granulocytic myeloid-derived suppressor cells (MDSC) and regulatory T lymphocytes, a higher M1/M2 ratio of macrophages as well as an increased activation of both DC and pDC were continually observed following HMGB1 inhibition. Moreover, blocking HMGB1 improved the efficacy of anti-PD-1 cancer monoimmunotherapy. We also reported that a significant fraction of HMGB1 encountered within cancer microenvironment (interstitial fluids) is oxidized and, in opposite to its reduced isoform, oxidized HMGB1 acts as a tolerogenic signal in a receptor for advanced glycation endproducts-dependent manner.

Conclusion

Collectively, we present evidence that extracellular HMGB1 blockade may complement first-generation cancer immunotherapies by remobilizing antitumor immune response.

Antibody-dependent cell cytotoxicity in monoclonal antibody-mediated tumor immunotherapy

Antibody-dependent cell cytotoxicity (ADCC) is critical in monoclonal antibody (mAb)-mediated cancer therapy. We recently showed that a tumor-specific mAb in combination with cyclophosphamide inhibited tumor cell growth and induced ADCC-synapses between tumor and effector cells in vivo, opening perspectives to enhance anti-tumor responses by manipulating the immune system.

Treatment algorithm and prognostic factors for patients with stage I-III carcinoma of the anal canal: a 20-year multicenter study

Despite a growing incidence in developed countries and a recent improved understanding of its pathogenesis, anal cancer management has not evolved over the past decades and drug combination used as first-line regimen still largely depends on clinician preferences. Aiming at paving the way for precision medicine, a large cohort of 372 HIV-negative patients diagnosed over a 20-year time period with locally advanced anal carcinoma was collected and carefully characterized at the clinical, demographic, histopathologic, immunologic, and virologic levels. Both the prognostic relevance of each clinicopathological parameter and the efficacy of different concurrent chemoradiation strategies were determined. Overall, the incidence of anal cancer peaked during the sixth decade (mean: 63.4) and females outnumbered males (ratio: 2.51). After completion of treatment, 95 (25.5%) patients experienced progression of persistent disease or local/distant recurrence and 102 (27.4%) died during the follow-up period (median: 53.8 months). Importantly, uni-multivariate analyses indicated that both negative HPV/p16^ink4a status and aberrant p53 expression were far better predictors for reduced progression-free survival than traditional risk factors such as tumor size and nodal status. As for overall survival, the significant influences of age at diagnosis, p16^ink4a status, cTNM classification as well as both CD3⁺ and CD4⁺ T-cell infiltrations within tumor microenvironment were highlighted. Cisplatin-based chemoradiotherapy was superior to both radiotherapy alone and other concurrent chemoradiation therapies in the treatment of HPV-positive tumors. Regarding their HPV-uninfected counterparts, frequent relapses were observed, whatever the treatment regimen administered. Taken together, our findings reveal that current anal cancer management and treatment have reached their limits. A dualistic classification according to HPV/p53 status should be considered with implications for therapy personalization and optimization.

Pyruvate dehydrogenase kinase/lactate axis: a therapeutic target for neovascular age-related macular degeneration identified by metabolomics

Neovascular age-related macular degeneration (nAMD) is the leading cause of blindness in aging populations. Here, we applied metabolomics to human sera of patients with nAMD during an active (exudative) phase of the pathology and found higher lactate levels and a shift in the lipoprotein profile (increased VLDL-LDL/HDL ratio). Similar metabolomics changes were detected in the sera of mice subjected to laser-induced choroidal neovascularization (CNV). In this experimental model, we provide evidence for two sites of lactate production: first, a local one in the injured eye, and second a systemic site associated with the recruitment of bone marrow-derived inflammatory cells. Mechanistically, lactate promotes the angiogenic response and M2-like macrophage accumulation in the eyes. The therapeutic potential of our findings is demonstrated by the pharmacological control of lactate levels through pyruvate dehydrogenase kinase (PDK) inhibition by dichloroacetic acid (DCA). Mice treated with DCA exhibited normalized lactate levels and lipoprotein profiles, and inhibited CNV formation. Collectively, our findings implicate the key role of the PDK/lactate axis in AMD pathogenesis and reveal that the regulation of PDK activity has potential therapeutic value in this ocular disease. The results indicate that the lipoprotein profile is a traceable pattern that is worth considering for patient follow-up. KEY MESSAGES: Lactate and lipoprotein profile are associated with the active phase of AMD and CNV development. Lactate is a relevant and functional metabolite correlated with AMD progression. Modulating lactate through pyruvate dehydrogenase kinase led to a decrease of CNV progression. Pyruvate dehydrogenase kinase is a new therapeutic target for neovascular AMD.

Diagnostic evaluation and management of seizures and status epilepticus in children with known epilepsy or new-onset seizures: A retrospective and comparative analysis

OBJECTIVES

The purpose of this study was to describe and compare the initial management, including clinical/biological investigation and treatment, of new-onset seizures and status epilepticus (SE) in children versus seizures and SE in those with known epilepsy.

METHODS

This was a retrospective, single-center, observational study conducted in an urban pediatric hospital in Paris. All patients, aged from 1 month to 18 years, admitted to the pediatric intensive care unit, the high-dependency care unit, and those who required hospitalization in the short-term unit of the emergency department between January 1 and December 31, 2014 for seizures and/or SE were included.

RESULTS

We analyzed the data of 190 children: new-onset seizures (N=118; group A) versus those with known epilepsy (N=72; group B). At least one diagnostic test was performed on 156 patients (82.1%) (group A, N=104, 88.1%; group B, N=52, 72.2%; P=0.05). In group B, blood levels of antiepileptic drugs were measured in 14 of the 38 patients with SE, of whom six were under dosed. Treatments were: first line, diazepam (group A, 80%; group B, 46%; P<0.001); second line, diazepam (group A, 56%; group B, 34%; P=0.02) or clonazepam (group A, 24%; group B, 46%; P=0.001); third line, phenytoin (group A, 54%; group B, 22%; P<0.001) or clonazepam (group A, 18%; group B, 61%; P<0.001).

CONCLUSION

Diagnostic evaluation and treatment should be individualized for children with known epilepsy.

Neonatal end-of-life decision-making almost 20 years after the EURONIC study: A French survey

Nearly 20 years ago the EURONIC study reported that French neonatologists sometimes deemed it legitimate to terminate the lives of newborn infants when the prognosis appeared extremely poor. Parents were not always informed of these decisions. Major change has occurred since then and is described herein.

MATERIAL AND METHODS

A survey was conducted in the Île-de-France region, from 1 January to 31 January 2016. Professionals from 15 neonatal intensive care units (NICUs) were invited to complete a questionnaire.

RESULTS

A total of 702 questionnaires were collected and 670 responses were analyzed. Knowledge of the law differed according to professional status, with 71% of MDs (medical staff, MS), compared with 28% of nonmedical staff (NMS) declaring that they had good knowledge of the law. Most MDs and NMS believed that withholding or withdrawing life-sustaining treatments (WWLST) could be decided and implemented after a delay. Half of them thought that WWLST would always result in death. Although required by law, a consulting MD attended the collegial meeting required before deciding on WWLST in only half of the cases. Parents were almost always informed of the decision thereafter by the physician in charge of their infant. The most frequent disagreement with parents was observed when WWLST was the option selected. In this case, most professionals suggested postponing WWLST, continuing intensive care and dialogue with parents, aiming at a final shared decision. Major differences were observed between NICUs with regard to the withdrawal of artificial nutrition and hydration. Finally, 14% of MDs declared that infant active terminations of life still occurred in their NICU. Major differences concern WWLST and active termination of life, whose meaning has been partly modified since 2001.

CONCLUSION

Several major changes were observed in this survey: (1) treatment withdrawal decisions are made today in agreement with the law; (2) parents' information and involvement in the decision process have profoundly changed; (3) active termination of life (euthanasia) very rarely occurs; only at the end of a process in accordance with ethical principles and within the law is this decision made.

Immunity drives TET1 regulation in cancer through NF-κB

Ten-eleven translocation enzymes (TET1, TET2, and TET3), which induce DNA demethylation and gene regulation by converting 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), are often down-regulated in cancer. We uncover, in basal-like breast cancer (BLBC), genome-wide 5hmC changes related to TET1 regulation. We further demonstrate that TET1 repression is associated with high expression of immune markers and high infiltration by immune cells. We identify in BLBC tissues an anticorrelation between TET1 expression and the major immunoregulator family nuclear factor κB (NF-κB). In vitro and in mice, TET1 is down-regulated in breast cancer cells upon NF-κB activation through binding of p65 to its consensus sequence in the TET1 promoter. We lastly show that these findings extend to other cancer types, including melanoma, lung, and thyroid cancers. Together, our data suggest a novel mode of regulation for TET1 in cancer and highlight a new paradigm in which the immune system can influence cancer cell epigenetics.

Search for Neutrinoless Quadruple-β Decay of ^{150}Nd with the NEMO-3 Detector

We report the results of a first experimental search for lepton number violation by four units in the neutrinoless quadruple-β decay of ^{150}Nd using a total exposure of 0.19 kg yr recorded with the NEMO-3 detector at the Modane Underground Laboratory. We find no evidence of this decay and set lower limits on the half-life in the range T_{1/2}>(1.1-3.2)×10^{21}  yr at the 90% C.L., depending on the model used for the kinematic distributions of the emitted electrons.

Promoting Vaginal Distribution of E7 and MCL-1 siRNA-Silencing Nanoparticles for Cervical Cancer Treatment

There is an urgent need to develop a less aggressive and more effective treatment against cervical lesions induced by different high-risk human papillomavirus (HR-HPV). We investigated the potential of a cocktail of small interfering RNA (siRNA) directed against the oncoprotein E6 (E6), the oncoprotein E7 (E7), or the antiapoptotic protein MCL-1 (MCL-1). The combination of siRNA anti-E7 and anti-MCL-1 demonstrated high efficacy on multiple HPV16 and HPV18 cell lines and no effects on healthy keratinocytes. This gene therapy has been considered for a vaginal administration since this route of application holds high potential for the treatment of diseases in the female reproductive tracts. Therefore, PEGylated lipoplexes have been designed and characterized to protect siRNA and to diffuse in the mucosal environment before they reach the cervico/vaginal epithelium. This new nanovector complexed to the combination of active siRNA induced an efficient mRNA knockdown since biological effects were obtained in vitro. This work also provided evidence that the PEGylated lipoplexes had appropriate physicochemical properties to diffuse into a mucin network according to size measurement experiments in artificial mucus. After demonstrating the distribution and the efficacy of siRNA into a 3D-cervical model lesion and through porcine vaginal mucosa, in vivo experiments in mouse have been performed under physiological conditions. This study revealed a complete and sustained coverage of the mucosal epithelium following an unique vaginal administration of fluorescent PEGylated lipoplexes. Overall, our results showed the potential of the PEGylated lipoplexes for the prolonged delivery of active siRNA to treat HPV-induced lesions.

PEGylation of lipoplexes: The right balance between cytotoxicity and siRNA effectiveness

The delivery of small interfering RNA (siRNA) is an attractive therapeutic approach to treat several pathologies, such as viral infections or cancers. However, the stability and the efficacy of these biotherapies are still a major obstacle to their use. Cationic liposomes (DOTAP/Chol/DOPE 1/0.75/0.5M ratio) have been complexed to siRNA (lipoplexes) in order to be administrated by the vaginal route, in the context of HPV16 induced cervical preneoplastic lesions. To overcome the constraint of the cervico-vaginal mucus, PEGylation is required to allow the diffusion of lipoplexes through it. Thereby, PEGylated lipoplexes coated with three types of polyethylene glycol (PEG) as DSPE-PEG2000, DSPE-PEG750 or C8-PEG2000-Ceramide (Ceramide-PEG2000) at different densities have been developed and characterized. PEGylated lipoplexes were successfully prepared and showed a hydrodynamic diameter around 200nm, appropriate for vaginal application. In vitro assays on HPV16 positive cell lines revealed that a positive charge of PEGylated lipoplexes allows a higher mRNA knockdown by siRNA. However, the cationic property is also associated to cytotoxicity. The addition of a high percentage of PEG prevented this toxicity but seemed also to reduce siRNA endosomal escape, probably by steric hindrance. The decreasing of PEG density of Ceramide-PEG2000 to 20% allows the release of siRNA and in consequence, biological activities, contrarily to DSPE-PEG. These results suggest that Ceramide-PEG is more appropriate for siRNA delivery compared to DSPE-PEG. In conclusion, the right balance between cytotoxicity and siRNA effectiveness has been found with the transfection of lipoplexes coated with 20% of Ceramide-PEG2000. This new nanovector could have a high potential against multiple mucosal diseases, such as human papillomavirus-induced genital lesions.

Abstract 4478: EGFR tyrosine kinase inhibitors overcome resistance to chemotherapy in malignant pleural mesothelioma

Background: Malignant pleural mesothelioma (MPM) is a cancer of the pleura mainly caused by exposure to asbestos fibers. Current treatments are unsatisfactory due to intrinsic chemoresistance of the tumor. We hypothesized that chemoresistance was due to epigenetic errors and evaluated the ability of HDAC inhibitors to improve treatment efficacy. We previously showed that valproic acid (VPA) improves the first line regimen of MPM both in vitro and in vivo (Vandermeers et al, 2009, Clinical Cancer Research 15: 2818). A clinical trial also demonstrated that VPA in combination with doxorubicin increases the response rate of second line patients (Scherpereel et al, 2011, European Respiratory Journal 37:129).

Methods: Transcriptomic profiling was performed by microarray analyses (Agilent). Gene expression was validated by quantitative RT-qPCR. Modulation of TGFα expression was performed by shRNA interference and transfection of a cDNA vector. Onset of apoptosis was assessed with the Annexin V assay.

Results: To evaluate the mechanisms associated with the response to chemotherapy, we compared two types of MPM cell lines (M14K and H28) characterized by a difference in sensitivity to doxorubicin+VPA. Microarray analyses and bioinformatic modeling of gene expression profiles revealed the most relevant candidate genes associated with sensitivity or resistance to this regimen. Among these, TGFα expression was associated with resistance to doxorubicin + VPA in a series of MPM cell lines. Silencing of TGFα by RNA interference in H28 cells correlated with a significant increase in apoptosis. On the other hand, overexpression of TGFα desensitized M14K cells to doxorubicin+VPA -induced apoptosis. Since TGFα interacts with the EGF receptor, we evaluated pharmacological inhibition using EGFR tyrosine kinase inhibitors (erlotinib and gefitinib) and the dual HDAC/EGFR inhibitor CUDC-101. As predicted, these TKI inhibitors improved efficacy of doxorubicin+VPA.

Conclusions: Our data demonstrate that TGFα is involved in resistance of MPM to chemotherapy and that TKI inhibitors overcome resistance to second line regimen.

Citation Format: Bernard Staumont, Chrisostome Costa, Fabian Vandermeers, Sathya Neelature Sriramareddy, Céline Mascaux, Arnaud Scherpereel, Bernard Duysinx, Renaud Louis, Philippe Delvenne, Pascale Hubert, Luc Willems. EGFR tyrosine kinase inhibitors overcome resistance to chemotherapy in malignant pleural mesothelioma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4478.

Effective antitumor therapy based on a novel antibody-drug conjugate targeting the Tn carbohydrate antigen

Antibody-drug conjugates (ADC), combining the specificity of tumor recognition by monoclonal antibodies (mAb) and the powerful cytotoxicity of anticancer drugs, are currently under growing interest and development. Here, we studied the potential of Chi-Tn, a mAb directed to a glyco-peptidic tumor-associated antigen, to be used as an ADC for cancer treatment. First, we demonstrated that Chi-Tn specifically targeted tumor cells in vivo. Also, using flow cytometry and deconvolution microscopy, we showed that the Chi-Tn mAb is rapidly internalized - condition necessary to ensure the delivery of conjugated cytotoxic drugs in an active form, and targeted to early and recycling endosomes. When conjugated to saporin (SAP) or to auristatin F, the Chi-Tn ADC exhibited effective cytotoxicity to Tn-positive tumor cells in vitro, which correlated with the level of tumoral Tn expression. Furthermore, the Chi-Tn mAb conjugated to auristatin F also exhibited efficient antitumor activity in vivo, validating for the first time the use of an anti-Tn antibody as an effective ADC.

Valproic acid improves second-line regimen of small cell lung carcinoma in preclinical models

With 5-year survival rates below 5%, small cell lung carcinoma (SCLC) has very poor prognosis and requires improved therapies. Despite an excellent overall response to first-line therapy, relapses are frequent and further treatments are disappointing. The goal of the study was to improve second-line therapy of SCLC.

The effect of chemotherapeutic agents was evaluated in cell lines (apoptosis, reactive oxygen species, and RNA and protein expression) and in mouse models (tumour development).

We demonstrate here that valproic acid, a histone deacetylase inhibitor, improves the efficacy of a second-line regimen (vindesine, doxorubicin and cyclophosphamide) in SCLC cells and in mouse models.

Transcriptomic profiling integrating microRNA and mRNA data identifies key signalling pathways in the response of SCLC cells to valproic acid, opening new prospects for improved therapies.

Valproic acid improves second-line regimen of SCLC response in preclinical modelshttp://ow.ly/Rsyd8

[Clowns in the pediatric intensive care unit in France]

INTRODUCTION

In recent years, in children's hospitals, clowns are involved in pediatric intensive care units (PICUs), at the bedside of the most severely ill children. This study is the first that addresses the work of professional clowns in the PICU. Its aim is to describe this practice in French hospitals.

METHODS

This study is a descriptive and prospective study conducted in December 2013 involving all the pediatric PICUs in French hospitals. A survey was emailed to all the PICU department heads in France.

RESULTS

Questionnaires were sent to 32 PICUs (21 pediatric and neonatal intensive care units and 11 pediatric intensive care units). The response rate was 81.2% (26 questionnaires completed). Among the 26 units that responded to the survey, clowns intervened in 13 of them (50%). Eight had an exclusive pediatric activity and five had both pediatric and neonatal activities. The clown visit was twice a week in six units and once in seven (missing data: one unit). The head doctor was satisfied or very satisfied in 92.3% of the cases (n=12/13). Medical clowns were trained and professional artists in all of the units. They worked in duo in most units (n=12/13) and solo in one unit. The clown rounds were preceded by a meeting with a healthcare worker in 12 of the 13 PICUs in which the clowns worked. They dialogued with a doctor in four and a nurse (or head nurse) in eight.

DISCUSSION

Prior to implementation, the clowns' work should be understood, accepted, and supported by each PICU team, to be validated in the overall care plan for each child.

CONCLUSION

Despite the severity of the situations met in the PICU, the instability of patients and the technical environment, clowning in PICUs appears to be a common and worthwhile practice in most French pediatric hospitals.

Soluble factors regulated by epithelial-mesenchymal transition mediate tumour angiogenesis and myeloid cell recruitment

Epithelial-mesenchymal transition (EMT) programmes provide cancer cells with invasive and survival capacities that might favour metastatic dissemination. Whilst signalling cascades triggering EMT have been extensively studied, the impact of EMT on the crosstalk between tumour cells and the tumour microenvironment remains elusive. We aimed to identify EMT-regulated soluble factors that facilitate the recruitment of host cells in the tumour. Our findings indicate that EMT phenotypes relate to the induction of a panel of secreted mediators, namely IL-8, IL-6, sICAM-1, PAI-1 and GM-CSF, and implicate the EMT-transcription factor Snail as a regulator of this process. We further show that EMT-derived soluble factors are pro-angiogenic in vivo (in the mouse ear sponge assay), ex vivo (in the rat aortic ring assay) and in vitro (in a chemotaxis assay). Additionally, conditioned medium from EMT-positive cells stimulates the recruitment of myeloid cells. In a bank of 40 triple-negative breast cancers, tumours presenting features of EMT were significantly more angiogenic and infiltrated by a higher quantity of myeloid cells compared to tumours with little or no EMT. Taken together, our results show that EMT programmes trigger the expression of soluble mediators in cancer cells that stimulate angiogenesis and recruit myeloid cells in vivo, which might in turn favour cancer spread.

Carcinogenic HPV infection in the cervical squamo-columnar junction

Recent studies have suggested the involvement of a unique population of cells at the cervical squamo-columnar junction (SCJ) in the pathogenesis of early (squamous intraepithelial lesion or SIL) and advanced (squamous cell and adeno-carcinomas) cervical neoplasia. However, there is little evidence to date showing that SCJ cells harbour carcinogenic HPV or are instrumental in the initial phases of neoplasia. This study was designed to (1) determine if normal-appearing SCJ cells contained evidence of carcinogenic HPV infection and (2) trace their transition to early SIL. Sections of cervix from high-risk reproductive age women were selected and SCJ cells were analysed by using several techniques which increasingly implicated HPV infection: HPV DNA (genotyping and in situ hybridization)/RNA (PCR), immunostaining for HPV16 E2 (an early marker of HPV infection), p16(ink4), Ki67, and HPV L1 protein. In 22 cases with a history of SIL and no evidence of preneoplastic lesion in the excision specimen, HPV DNA was isolated from eight of ten with visible SCJ cells, six of which were HPV16/18 DNA-positive. In five of these latter cases, the SCJ cells were positive for p16(ink4) and/or HPV E2. Transcriptionally active HPV infection (E6/E7 mRNAs) was also detected in microdissected SCJ cells. Early squamous atypia associated with the SCJ cells demonstrated in addition diffuse p16(ink4) immunoreactivity, elevated proliferative index, and rare L1 antigen positivity. We present for the first time direct evidence that normal-appearing SCJ cells can be infected by carcinogenic HPV. They initially express HPV E2 and their progression to SIL is heralded by an expanding metaplastic progeny with increased proliferation and p16(ink4) expression. Whether certain SCJs are more vulnerable than others to carcinogenic HPV genotypes and what variables determine transition to high-grade SIL remain unresolved, but the common event appears to be a vulnerable cell at the SCJ.

Early and late complications after liver transplantation for propionic acidemia in children: a two centers study

Propionic acidemia (PA) is a severe metabolic disorder with cardiac and neurologic complications and a poor quality of life. Liver transplantation (LT) was thus proposed in PA to increase enzyme activity. We studied retrospectively LT in PA in two European centers. Twelve patients underwent 17 LTs between 1991 and 2013. They developed severe, unusual and unexpected complications, with high mortality (58%). When present, the cardiomyopathy resolved and no acute metabolic decompensation occurred allowing dietary relaxation. Renal failure was present in half of the patients before LT and worsened in all of them. We suggest that cardiac and renal functions should be assessed before LT and monitored closely afterward. A renal sparing immunosuppression should be used. We speculate that some complications may be related to accumulated toxicity of the disease and that earlier LT could prevent some of these consequences. As kidney transplantation has been performed successfully in methylmalonic acidemia, a metabolic disease in the same biochemical pathway, the choice of the organ to transplant could be further discussed.

Development of anti-E6 pegylated lipoplexes for mucosal application in the context of cervical preneoplastic lesions

Cervical cancer induced by human papillomavirus (HPV) is the fourth highest mortality causing cancer in women despite the use of prophylactic vaccines. E6 targeting represents an attractive strategy to treat this cancer. Indeed, oncoprotein E6 is produced by keratinocytes infected by HPV and is partially responsible for carcinogenesis. E6 interferes with the apoptosis process in stressed cells by degradation of p53 tumor suppressor gene. Our strategy consists in using E6 siRNA complexed with pegylated lipoplexes. The addition of hydrophilic polymer around the nanoparticles is crucial to use them by vaginal application on account of cervicovaginal mucus. Physicochemical characteristics were evaluated and in vitro assays were performed to evaluate transfection potential, E6 mRNA extinction and p53 re-expression. Cationic liposomes DOTAP/Cholesterol/DOPE 1/0.75/0.5 (N/P 2.5) with or without 50% DSPE-PEG2000 and associated with siE6 have demonstrated good physicochemical characteristics in terms of complexation, size, surface charge and stability. Both lipoplexes have been tested on CaSki cell line (HPV 16+) with 50 nM and 100 nM of siE6. Lipoplexes formulations induce 30-40% of E6 mRNA extinction and induce the re-expression of p53. In conclusion, pegylated anti-E6 lipoplexes have demonstrated their efficiency to cross the cellular membrane and to release siRNA into the cytoplasm confirmed by final p53 protein production.

ΔNp63 isoform-mediated β-defensin family up-regulation is associated with (lymph)angiogenesis and poor prognosis in patients with squamous cell carcinoma

Beside a role in normal development/differentiation, high p63 immunoreactivity is also frequently observed in squamous cell carcinoma (SCC). Due to the complexity of the gene, the role of each p63 isotype in tumorigenesis is still confusing. Constitutively produced or induced in inflammatory conditions, human beta-defensins (HβDs) are cationic peptides involved in host defenses against bacteria, viruses and fungi. Here, we investigated both the role of p63 proteins in the regulation of HβDs and the implication of these antimicrobial peptides in tumor (lymph)angiogenesis. Thus, in contrast to TAp63 isotypes, we observed that ΔNp63 proteins (α, β, γ) induce HβD1, 2 and 4 expression. Similar results were observed in cancer tissues and cell lines. We next demonstrated that ΔNp63-overexpressing SCC are associated with both a poor prognosis and a high tumor vascularisation and lymphangiogenesis. Moreover, we showed that HβDs exert a chemotactic activity for (lymphatic) endothelial cells in a CCR6-dependent manner. The ability of HβDs to enhance (lymph)angiogenesis in vivo was also evaluated. We observed that HβDs increase the vessel number and induce a significant increase in relative vascular area compared to negative control. Taken together, the results of this study suggest that ΔNp63-regulated HβD could promote tumor (lymph)angiogenesis in SCC microenvironment.

HMGB1 secretion during cervical carcinogenesis promotes the acquisition of a tolerogenic functionality by plasmacytoid dendritic cells

Acquisition of an impaired functionality by plasmacytoid dendritic cells (pDCs) contributing to cancer progression has been documented in different types of cancers. In the present study, we postulate that molecules secreted by (pre)neoplastic epithelial cells of the genital tract (cervix/vulva) might attract pDCs but also modify their proper functionality, allowing these cells to initiate a tolerogenic response interfering with antitumor immunity. We demonstrated that pDCs are recruited during the cervical metaplasia-dysplasia-cancer sequence, through the action of their chemoattractant, chemerin. We showed that stimulated-pDCs exposed to cervical/vulvar tumor microenvironment display an altered phenotype. We also demonstrated that cervical/vulvar neoplastic keratinocytes inhibit the proper function of pDCs by decreasing their IFNα secretion in response to CpG oligonucleotides. In parallel, we observed that (pre)neoplastic areas of the cervix are infiltrated by FoxP3(+) Treg cells which colocalize with pDCs. Accordingly, pDCs cocultured with cervical/vulvar neoplastic keratinocytes have the capacity to induce a Treg cell differentiation from naïve CD4(+) T cells, which is in agreement with the development of a tolerogenic response. We identified HMGB1 as a soluble factor produced by neoplastic keratinocytes from the genital tract involved in pDCs functional alteration. Indeed, this molecule inhibited pDC maturation, decreased IFNα secretion following TLR9 stimulation and forced these cells to become tolerogenic. In contrast, inhibition of HMGB1 restored pDC phenotype. Our findings indicate that the use of inhibitory molecules notably directed against HMGB1 in cervical/vulvar (pre)neoplastic lesions might prevent alterations of pDCs functionality and represent an attractive therapeutic strategy to overcome immune tolerance in cancers.

NF-κB-induced KIAA1199 promotes survival through EGFR signalling

Constitutive activation of EGFR- and NF-κB-dependent pathways is a hallmark of cancer, yet signalling proteins that connect both oncogenic cascades are poorly characterized. Here we define KIAA1199 as a BCL-3- and p65-dependent gene in transformed keratinocytes. KIAA1199 expression is enhanced on human papillomavirus (HPV) infection and is aberrantly expressed in clinical cases of cervical (pre)neoplastic lesions. Mechanistically, KIAA1199 binds Plexin A2 and protects from Semaphorin 3A-mediated cell death by promoting EGFR stability and signalling. Moreover, KIAA1199 is an EGFR-binding protein and KIAA1199 deficiency impairs EGF-dependent Src, MEK1 and ERK1/2 phosphorylations. Therefore, EGFR stability and signalling to downstream kinases requires KIAA1199. As such, KIAA1199 promotes EGF-mediated epithelial-mesenchymal transition (EMT). Taken together, our data define KIAA1199 as an oncogenic protein induced by HPV infection and constitutive NF-κB activity that transmits pro-survival and invasive signals through EGFR signalling.

Altered α-defensin 5 expression in cervical squamocolumnar junction: implication in the formation of a viral/tumour-permissive microenvironment

Human papillomavirus (HPV) infection, particularly type 16, is causally associated with cancer of the uterine cervix, which mainly develops at the squamocolumnar (SC) junction. The progression of cervical HPV infections into (pre)neoplastic lesions suggests that viral antigens are not adequately recognized by innate immunity or presented to the adaptive immune system. Members of the defensin family have recently been found to inhibit viral and bacterial pathogens, to stimulate the migration of immune cells and to play a role in anticancer responses. In the present study, we focused on the poorly characterized human α-defensin 5 (HD-5) and its possible role in these processes. We showed that HD-5 was able to prevent HPV virion entry into cervical keratinocytes and to influence adaptive immunity. Indeed, this peptide specifically induced the chemoattraction and proliferation of both activated T lymphocytes and immature dendritic cells in a CCR2/CCR6-dependent manner and stimulated the infiltration of these professional antigen-presenting cells in a (pre)neoplastic epithelium transplanted in vivo in immunodeficient mice. No chemotactic effect was observed with plasmacytoid dendritic cells, macrophages or natural killer cells. Proliferative and angiogenic effects of HD-5 were also assessed in vitro and in vivo. However there was a striking regional disparity in expression of HD-5, being prominent in ectocervical, vaginal and vulvar neoplasia, while absent, or nearly so, in the cervical SC junction. Taken together, these results suggest one possible explanation for why the SC junction is uniquely vulnerable to both high-risk HPV infection (via reduced HD-5 expression and viral entry) and progression of neoplasia (via altered cell-mediated immune responses and altered microenvironment).

Idiopathic CD4 lymphocytopenia: clinical and immunologic characteristics and follow-up of 40 patients

Idiopathic CD4 T lymphocytopenia (ICL) is a rare and severe condition with limited available data. We conducted a French multicenter study to analyze the clinical and immunologic characteristics of a cohort of patients with ICL according to the Centers for Disease Control criteria.We recruited 40 patients (24 female) of mean age 44.2 ± 12.2 (19-70) years. Patients underwent T-lymphocyte phenotyping and lymphoproliferation assay at diagnosis, and experiments related to thymic function and interferon (IFN)-γ release by natural killer (NK) cell were performed. Mean follow-up was 6.9 ± 6.7 (0.14-24.3) years. Infectious, autoimmune, and neoplastic events were recorded, as were outcomes of interleukin 2 therapy.In all, 25 patients had opportunistic infections (12 with human papillomavirus infection), 14 had autoimmune symptoms, 5 had malignancies, and 8 had mild or no symptoms. At the time of diagnosis, the mean cell counts were as follows: mean CD4 cell count: 127/mm (range, 4-294); mean CD8: 236/mm (range, 1-1293); mean CD19: 113/mm (range, 3-547); and mean NK cell count: 122/mm (range, 5-416). Most patients had deficiency in CD8, CD19, and/or NK cells. Cytotoxic function of NK cells was normal, and patients with infections had a significantly lower NK cell count than those without (p = 0.01). Patients with autoimmune manifestations had increased CD8 T-cell count. Proliferation of thymic precursors, as assessed by T-cell rearrangement excision circles, was increased. Six patients died (15%). CD4 T-cell count <150/mm and NK cell count <100/mm were predictors of death.In conclusion, ICL is a heterogeneous disorder often associated with deficiencies in CD8, CD19, and/or NK cells. Long-term prognosis may be related to initial CD4 and NK cell deficiency.

Dendritic cells in Barrett's esophagus carcinogenesis: an inadequate microenvironment for antitumor immunity?

Barrett's esophagus corresponds to the replacement of the normal esophageal squamous epithelium by a columnar epithelium through a metaplastic process. This tissue remodeling is associated with chronic gastroesophageal reflux and constitutes a premalignant lesion leading to a 30- to 60-fold increase in the risk to evolve into esophageal adenocarcinoma. The present study aimed to investigate a possible immune evasion in Barrett's esophagus favoring esophageal adenocarcinoma development. We demonstrated that myeloid and plasmacytoid dendritic cells are recruited during the esophageal metaplasia-dysplasia-carcinoma sequence, through the action of their chemoattractants, macrophage inflammatory protein 3α and chemerin. Next, we showed that, in contrast to plasmacytoid dendritic cells, myeloid dendritic cells, co-cultured with Barrett's esophagus and esophageal adenocarcinoma cell lines, display a tolerogenic phenotype. Accordingly, myeloid dendritic cells co-cultured with esophageal adenocarcinoma cell lines stimulated regulatory T cell differentiation from naïve CD4(+) T cells. In agreement with those results, we observed that both metaplastic areas and (pre)malignant lesions of the esophagus are infiltrated by regulatory T cells. In conclusion, soluble factors secreted by epithelial cells during the esophageal metaplasia-dysplasia-carcinoma sequence influence dendritic cell distribution and promote tumor progression by rendering them tolerogenic.

Abstract 984: The role of TGF-alpha in the resistance to mesothelioma chemotherapy

Background. Malignant mesothelioma (MM) is a cancer of the pleura caused mainly by the inhalation of asbestos fibers. The impact of chemotherapy on the outcome of patients with MM is still unclear. We hypothesized that unresponsiveness to chemotherapy is due to inadequate gene expression in tumor cells. We have previously shown that inhibitors of histones deacetylases (such as valproate, VPA) significantly increases the efficacy of compounds used in chemotherapy (Vandermeers et al, 2010, Clinical Cancer Research 15: 2818). A recent clinical trial on relapsing MM patients has shown that VPA in combination with doxorubicin improves response rates and quality of life (Scherpereel et al, 2011, European Respiratory Journal 37:129).

Results. To study the mechanisms associated with the response to chemotherapy, we compared two types of cell lines (M14K and H28) characterized by a difference in sensitivity to doxorubicin+VPA. Using Agilent microarrays and RT-qPCR, we observed that the basal expression level of TGFα was higher in "resistant" H28 compared to "sensitive" M14K cells. To evaluate the functional relevance of TGFα, we modulated its expression either by RNA interference or by transfection of a cDNA vector. A decrease of TGFα expression correlated with induction of apoptosis. Inversely, an inhibition of apoptosis occurred when TGFα was over-expressed. As TGFα is the ligand of EGFR, we tested the effect of gefitinib and erlotinib in combination with VPA+doxorubicin. Both EGFR inhibitors increased apoptosis induced by VPA+doxorubicin in H28 chemoresistant cells. Finally, the VPA+doxorubicin+erlotinib regimen prevented tumor growth in two mouse models (ZL34 in SCID and AB12 in Balb/c).

Conclusions. Our data demonstrates that TGFα is involved in the chemoresistance to VPA+doxorubicin, a second-line regimen for MM. Although inefficient alone, tyrosine kinase inhibitors synergize to induce apoptosis in chemoresistant cells and prevent tumor growth in mouse models.

Citation Format: Sathya Neelature Sriramareddy, Fabian Vandermeers, Chrisostome Costa, Céline Mascaux, Arnaud Scherpereel, Philippe Delvenne, Pascale Hubert, Luc L. Willems. The role of TGF-alpha in the resistance to mesothelioma chemotherapy. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 984. doi:10.1158/1538-7445.AM2013-984

Interleukin-32 expression is associated with a poorer prognosis in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) represent the sixth most common malignancy diagnosed worldwide. Patient's survival is low due the high frequency of tumor recurrence. Inflammation promotes carcinogenesis as well as the formation of metastasis. Indeed, proinflammatory mediators are known to stimulate the expression of specific transcription factors such as Snai1 and to increase the ability of tumor cells to migrate into distant organs. The atypical interleukin-32 (IL32) was mainly described to exacerbate inflammatory responses in rheumatoid arthritis and inflammatory bowel diseases. IL32 is expressed in various cancers but its role in HNSCC physiology is still unexplored. Here, we analyzed the expression of IL32 and its implication on HNSCC aggressiveness. We showed that patients with tumor expressing high amounts of IL32 exhibit decreased disease-free periods (20.5 mo vs. 41 mo, P = 0.0041) and overall survival (P = 0.0359) in comparison with individuals with weak IL32 tumor expression. This overexpression was negatively correlated with gender (P = 0.0292) and p53 expression (P = 0.0307). In addition, in vitro data linked IL32 expression to metastasis formation since IL32 inhibition decreased Snai1 expression and tumor cell migration in a Boyden chamber assay. Our data provide new insight into the role of IL32 in HNSCC aggressiveness.

Tailored SWCNT functionalization optimized for compatibility with epoxy matrices

We have modified single walled carbon nanotubes (SWCNTs) with well defined matrix-based architectures to improve interface interaction in SWCNT/epoxy composites. The hardener and two pre-synthesized oligomers containing epoxy and hardener moieties were covalently attached to the SWCNT walls by in situ diazonium or carboxylic coupling reactions. In this way, SWCNTs bearing amine or epoxide-terminated fragments of different molecular weights, which resemble the chemical structure of the cured resin, were synthesized. A combination of characterization techniques such as Raman and infrared absorption (FTIR) spectroscopy, elemental analysis and coupled thermogravimetry-FTIR spectroscopy were used to identify both the functional groups and degree of functionalization of SWCNTs synthesized by the laser ablation and arc-discharge methods. Depending on the type of reaction employed for the chemical functionalization and the molecular weight of the attached fragment, it was possible to control the degree of functionalization and the electronic properties of the functionalized SWCNTs. Improved dispersion of SWCNTs in the epoxy matrix was achieved by direct integration without using solvents, as observed from optical microscopy and rheology measurements of the SWCNT/epoxy mixtures. Composite materials using these fillers are expected to exhibit improved properties while preserving the thermosetting architecture.

Production of large numbers of plasmacytoid dendritic cells with functional activities from CD34(+) hematopoietic progenitor cells: use of interleukin-3

Plasmacytoid dendritic cells (pDC), a subset of dendritic cells characterized by a rapid and massive type-I interferon secretion through the Toll-like receptor pathway in response to viral infection, play important roles in the pathogenesis of several diseases, such as chronic viral infections (e.g., hepatitis C virus, human immunodeficiency virus), autoimmunity (e.g., psoriasis, systemic lupus erythematosus), and cancer. As pDC represent a rare cell type in the peripheral blood, the goal of this study was to develop a new method to efficiently generate large numbers of cells from a limited number of CD34(+) cord blood progenitors to provide a tool to resolve important questions about how pDC mediate tolerance, autoimmunity, and cancer. Human CD34(+) hematopoietic progenitor cells isolated from cord blood were cultured with a combination of Flt3-ligand (Flt3L), thrombopoietin (TPO), and one of the following cytokine: interleukin (IL)-3, interferon-β(IFN-β), or prostaglandin E2(PGE(2)). Cells obtained in the different culture conditions were analyzed for their phenotype and functional characteristics. The addition of IL-3 cooperates with Flt3L and TPO in the induction of pDC from CD34(+) hematopoietic progenitor cells. Indeed, Flt3L/TPO alone or supplemented with prostaglandin E2 or interferon-β produced smaller amounts of pDC from hematopoietic progenitor cells. In addition, pDC generated in Flt3L/TPO/IL-3 cultures exhibited morphological, immunohistochemical, and functional features of peripheral blood pDC. We showed that IL-3, in association with Flt3L and TPO, provides an advantageous tool for large-scale generation of pDC. This culture condition generated, starting from 2 × 10(5) CD34(+) cells, up to 2.6 × 10(6) pDC presenting features of blood pDC.

Antibody-dependent cell cytotoxicity synapses form in mice during tumor-specific antibody immunotherapy

Antibody-dependent cell cytotoxicity (ADCC) plays a critical role in monoclonal antibody (mAb)-mediated cancer therapy. ADCC, however, has not been directly shown in vivo but inferred from the requirement for IgG Fc receptors (FcγR) in tumor rejection in mice. Here, we investigated the mechanism of action of a Tn antigen-specific chimeric mAb (Chi-Tn), which binds selectively to a wide variety of carcinomas, but not to normal tissues, in both humans and mice. Chi-Tn mAb showed no direct toxicity against carcinomas cell lines in vitro but induced the rejection of a murine breast tumor in 80% to 100% of immunocompetent mice, when associated with cyclophosphamide. Tumor rejection was abolished in Fc receptors-associated γ chain (FcR-γ)-deficient mice, suggesting a role for ADCC. Indeed, tumor cells formed stable conjugates in vivo with FcR-γ chain-expressing macrophages and neutrophils in Chi-Tn mAb-treated but not in control mAb-treated mice. The contact zone between tumor cells and ADCC effectors accumulated actin, FcγR and phospho-tyrosines. The in vivo formed ADCC synapses were organized in multifocal supra-molecular activation clusters. These results show that in vivo ADCC mediated by macrophages and neutrophils during tumor rejection by Chi-Tn mAb involves a novel type of multifocal immune synapse between effectors of innate immunity and tumor cells.