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Background KRAS testing is required before treatment initiation of cetuximab in the management of metastatic colorectal cancer (mCRC). The objective of the study was to examine the current situation in 2011 regarding KRAS testing in the initial management of mCRC. Methods This observational, retrospective, national study was carried out between March 28th and April 8th 2011. During this period 538 patients with mCRC were included across 160 french hospitals. The main objective was to assess the rate of KRAS testing in patients who had started first line (L1) treatment for mCRC. The secondary objectives were to describe the time taken and techniques used for KRAS testing, the possible reasons this test was not requested, to describe and analyse the clinical characteristics of the patients and the planned L1 treatments and those finally received. Results KRAS testing was carried out for 433 patients (81.1%) and not carried out for 101 patients (18.9%). The main reasons for not requesting the KRAS status were (several answers possible): anti-EGFR not prescribed (n = 58), candidate for surgery (n = 8), samples not useable (n = 5), age of the patient (n = 3), other (n = 24), data missing (n = 13). The genotyping results were available after a mean delay of 23.6 ± 28.2 days. The KRAS testing was requested by an oncologist (45.5%), a gastroenterologist (31%), a surgeon (11.2%), a pathologist (7.2%) or a multidisciplinary group (5.1%) approximately 15 days (-66.5;33.6) median (min; max) after the diagnosis of metastases, and 15 days (-66.9;3.7) median (min; max) before the start of L1 treatment. Result of KRAS status had not been received before the L1 treatment was chosen in 56.6% of the patients. For patients with wild-type KRAS status whose therapeutic management was modified after the result of KRAS testing (n = 108), this change was a prescription of an anti-EGFR in 77.8% of the cases. Conclusion The Flash-KRAS study is the first one to assess the current modalities of KRAS genotyping in France. It shows that in 2011 the KRAS test is an integral part of the management of patients with mCRC. Nonetheless, it shows disparities between regions in terms of time to obtain results, which need to be improved to be compatible with the therapeutic management. Disclosure M. Ducreux: Merck Serono. A. Lievre: Merck Serono. P. Artru: Merck Serono. M. Guiu: Merck Serono. J. Merlin: Merck Serono. J.C. Sabourin: Merck Serono. J. Viguier: Merck Serono. A. Seronde: Merck Serono. P. Laurent-Puig: Merck Serono. All other authors have declared no conflicts of interest.

International audience; In vertebrates, skeletal muscle myofibers display different contractile and metabolic properties associated with different mitochondrial content and activity. We have previously identified a mitochondrial triiodothyronine receptor (p43) regulating mitochondrial transcription and mitochondrial biogenesis. When overexpressed in skeletal muscle, it increases mitochondrial DNA content, stimulates mitochondrial respiration, and induces a shift in the metabolic and contractile features of muscle fibers toward a slower and more oxidative phenotype. Here we show that a p43 depletion in mice decreases mitochondrial DNA replication and respiratory chain activity in skeletal muscle in association with the induction of a more glycolytic muscle phenotype and a decrease of capillary density. In addition, p43(-/-) mice displayed a significant increase in muscle mass relative to control animals and had an improved ability to use lipids. Our findings establish that the p43 mitochondrial receptor strongly affects muscle mass and the metabolic and contractile features of myofibers and provides evidence that this receptor mediates, in part, the influence of thyroid hormone in skeletal muscle.

Published in Annales de Pathologie 31(5), Supplement, page S142; National audience; Introduction.- Le cetuximab est un anticorps monoclonal anti-EGFR indiqué dans le traitement du cancer colorectal métastatique (CCRm). Il a été démontré qu'une tumeur dont le gène KRAS est muté ne répondait pas au traitement anti-EGFR. Il est donc nécessaire avant la prescription d'un anti-EGFR (AMM modifiée en 2008) de rechercher le statut mutationnel KRAS au niveau de la tumeur colorectale. Dans ce contexte, l'étude Flash-KRAS a donc été mise en place afin de décrire les pratiques actuelles concernant le génotypage KRAS. Objectifs.- L'objectif principal est d'évaluer le taux de prescription du test KRAS chez des patients ayant commencé un traitement de première ligne d'un cancer colorectal métastatique. Les objectifs secondaires sont variés et vont permettre de décrire les délais et les techniques utilisées pour le génotypage KRAS, les raisons éventuelles de non recourt à ce test, décrire et analyser les caractéristiques cliniques des patients et les traitements de première ligne métastatique prévus et ceux reçus. Méthodes.- Flash-KRAS est une étude pharmaco-épidémiologique nationale, rétrospective, non interventionnelle, multicentrique et de courte durée. Durant 2 semaines (du 28 mars au 8 avril 2011), tous les centres participant devaient inclure chaque patient qui était vu à l'hôpital pour une consultation, en HDJ ou en hospitalisation conventionnelle et ayant commencé un traitement de première ligne entre le 1er janvier et le 27 mars 2011. Résultats.- Plus de 1700 cliniciens hospitaliers (oncologues, gastro-entérologues ou radiothérapeutes) ont été sollicités par courrier et téléphone pour participer. Trois cent soixante-six médecins ont répondu positivement. À la date du 16 mai 2011, date limite de retour des questionnaires, 149 médecins ont participé activement à l'étude et ont renvoyé 501 questionnaires patients. Le nombre moyen de questionnaires patient par médecin était de 3,4 (1-14). Discussion.- Les données sont en cours d'analyse et seront présentées lors du congrès. Conclusion.- Il s'agit de la première étude observationnelle rétrospective portant sur une grande cohorte de patients permettant de faire un état des lieux du génotypage KRAS en 2011 en France. Trois ans après la mise en place de la recherche des mutations KRAS dans le cadre d'un traitement par anti-EGFR pour un CCRm, cette étude nous permettra de faire un état des lieux et d'évaluer l'implantation en routine de ce biomarqueur.

International audience; Every year, acute lymphoblastic leukaemia (ALL) affects about 400 children aged

International audience; Drug delivery nanosystems are currently used in human therapy. In preliminary studies we have observed that Eudragit RS nanoparticles, prepared by nanoprecipitation or double emulsion techniques, are cytotoxic for NR8383 rat macrophages. In this study, we expand our previous analysis and suggest that unloaded Eudragit RS nanoparticles prepared by nanoprecipitation (NP/ERS) may induce important morphological and biochemical cellular modifications leading to cellular death. In NR8383 rat macrophages cell line exposed to doses varying from 15 to 100 μg/mL, NP/ERS nanoparticles are internalized inside the cells, reach the mitochondria and alter the structure of these organelles. In addition, the exposure to nanoparticles induces cellular autophagy as demonstrated by electron microscopy analysis, microchip array, qRT-PCR and Western blot assays. Although toxicity of nanoparticles has already been evidenced, it is the first time that results show clearly that the toxicity of polymeric nanovectors may be related to an activation of autophagy.

International audience; Our aim was to get new information about the Peroxisome Proliferator Activated Receptor gamma (PPARγ)-independent pathway involved in the antiproliferative action of PPARγ ligands in breast cancer cells. We investigated the effects of Troglitazone (TGZ), Ciglitazone (CGZ), Rosiglitazone (RGZ) and, 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ(2)) on the hormone-dependent breast cancer cell line MCF7. The early transcription factor EGR1 (Early Growth Response gene 1) mRNA and protein levels peaked after 3h of incubation with 25μM TGZ, CGZ or 15d-PGJ(2) and then gradually decreased. RGZ, the most potent activator of PPARγ, did not show this effect. The PPARγ antagonist GW 9662 did not block EGR1 mRNA induction which also still occurred in case of PPARγ silencing as well as in case of treatment with the PPARγ-inactive compound Δ2-TGZ. EGR1 mRNA induction required ERK1/2 phosphorylation which was not blocked by EGF Receptor (EGFR) inhibition. The ERK1/2 pathway was also involved in Δ2-TGZ-induced EGR1 mRNA expression in the hormone-independent breast cancer cell line MDA-MB-231. Using the fluorescent dye Fura2, we showed in MCF7 that TGZ or Δ2-TGZ induced an immediate increase in cytosolic calcium which was required for ERK1/2 phosphorylation and EGR1 mRNA induction as demonstrated by calcium chelation experiments. Furthermore, in MCF7 transfected with siRNA targeting EGR1, Δ2-TGZ inhibited less efficiently cell proliferation.

International audience; Numerous recent studies indicate that most anticancer effects of PPARγ agonists like thiazolidinediones are the result of PPARγ-independent pathways. These conclusions were obtained by several approaches including the use of thiazolidinedione derivatives like Δ2-Troglitazone (Δ2-TGZ) that does not activate PPARγ. Since biotinylation has been proposed as a mechanism able to increase the specificity of drug delivery to cancer cells which could express a high level of vitamin receptor, a biotinylated derivative of Δ2-TGZ (bΔ2-TGZ) has been synthetized. In the present article, we have studied the in vitro effects of this molecule on both hormone-dependent (MCF-7) and hormone-independent (MDA-MB-231) breast cancer cells. In both cell lines, bΔ2-TGZ was more efficient than Δ2-TGZ to decrease cell viability. bΔ2-TGZ was also more potent than Δ2-TGZ to induce the proteasomal degradation of cyclin D1 in both cell lines and those of ERα in MCF-7 cells. However, in competition experiments, the presence of free biotin in the culture medium did not decrease the antiproliferative action of bΔ2-TGZ. Besides, other compounds that had no biotin but that were substituted at the same position of the phenolic group of the chromane moiety of Δ2-TGZ decreased cell viability similarly to bΔ2-TGZ. Hence, we concluded that the increased antiproliferative action of bΔ2-TGZ was not due to biotin itself but to the functionalization of the terminal hydroxyl group. This should be taken into account for the design of new thiazolidinedione derivatives able to affect not only hormone-dependent but also hormone-independent breast cancer cells in a PPARγ-independent pathway.

TIMP-1, a well-known MMP inhibitor, displays other biological activities such as cell survival, proliferation and differentiation in hematopoietic cells. In this report, we investigated the role of the Src-related kinase Lyn in TIMP-1 induced UT-7 erythroleukemic cell survival. We showed that (i) tyrosine 507 of Lyn was dephosphorylated and Lyn kinase activity enhanced by TIMP-1, (ii) Lyn silencing suppressed TIMP-1 anti-apoptotic activity and (iii) Lyn was activated upstream the JAK2/PI 3-kinase/Akt pathway. Our data suggest a novel role for Lyn in erythroid cell survival.

International audience; Driven by a multidisciplinary approach combination (Structure-Based (SB) Three-Dimensional Quantitative Structure-Activity Relationships (3-D QSAR), molecular modeling, organic chemistry and various biological evaluations) here is reported the disclosure of new thienopyrimidines 1-3 as inhibitors of KDR activity and human umbilical vein endothelial cell (HUVEC) proliferation. More specifically, compound 2f represents a new lead compound that inhibits VEGFR-2 and HUVEC at μM concentration. Moreover by the mean of an endothelial cell tube formation in vitro model 2f tartaric acid salt proved to block angiogenesis of HUVEC at μM level.

International audience; The major effect of T3 on mitochondrial activity has been partly explained by the discovery of p43, a T3-dependent transcription factor of the mitochondrial genome. P43 is imported into mitochondria in an atypical manner which is not yet fully understood. Our aim was to characterize the p43 sequences inducing its mitochondrial import, using in organello import experiments with wild-type or mutated proteins and validation in CV1 cells. We find that several sequences define the mitochondrial addressing. Two alpha helices in the C-terminal part of p43 are actual mitochondrial import sequences as fusion to a cytosolic protein induces its mitochondrial translocation. Helix 5 drives the atypical mitochondrial import process, whereas helices 10/11 induce a classical import process. However, despite its inability to drive a mitochondrial import, the N-terminal region of p43 also plays a permissive role as in the presence of the C-terminal import sequences different N-terminal regions determine whether the protein is imported or not. These results can be extrapolated to other mitochondrial proteins related to the nuclear receptor superfamily, devoid of classical mitochondrial import sequences.

International audience; Antiangiogenic and vascular disrupting agents are in the current cancer therapeutic armamentarium. A better understanding of the intricate mechanisms ruling neovessel survival within tumors during or after treatment is needed. Refinement of imaging and a growing knowledge of molecular biology of tumor vascularization provide new insights. It is necessary to define suitable methods for monitoring tumor response and appropriate tools to analyze data. This review compares most commonly used preclinical models, considering their recent improvements, and describes promising new approaches such as microfluidics, real-time electrical impedance based technique and noninvasive imaging techniques. The advantages and limitations of the in vitro, ex vivo and in vivo models are discussed. This review also provides a critical summary of emerging approaches using mathematical modeling.

International audience; PURPOSE: Fetal folate deficiency may increase the risk of subsequent childhood acute leukemia (AL), since folates are required for DNA methylation, synthesis, and repair, but the literature remains scarce. This study tested the hypothesis that maternal folic acid supplementation before or during pregnancy reduces AL risk, accounting for the SNPs rs1801133 (C677T) and rs1801131 (A1298C) in MTHFR and rs1801394 (A66G) and rs1532268 (C524T) in MTRR, assumed to modify folate metabolism. METHODS: The nationwide registry-based case-control study, ESCALE, carried out in 2003-2004, included 764 AL cases and 1,681 controls frequency matched with the cases on age and gender. Information on folic acid supplementation was obtained by standardized telephone interview. The genotypes were obtained using high-throughput platforms and imputation for untyped polymorphisms. Odds ratios (OR) were estimated using unconditional regression models adjusted for potential confounders. RESULTS: AL was significantly inversely associated with maternal folic acid supplementation before and during pregnancy (OR = 0.4; 95 % confidence interval: [0.3-0.6]). MTHFR and MTRR genetic polymorphisms were not associated with AL. However, AL was positively associated with homozygosity for any of the MTHFR polymorphisms and carriership of both MTRR variant alleles (OR = 1.6 [0.9-3.1]). No interaction was observed between MTHFR, MTRR, and maternal folate supplementation. CONCLUSION: The study findings support the hypothesis that maternal folic acid supplementation may reduce the risk of childhood AL. The findings also suggest that the genotype homozygous for any of the MTHFR variants and carrying both MTRR variants could be a risk factor for AL.

Integrins play a role in the resistance of advanced cancers to radiotherapy and chemotherapy. In this study, we show that high expression of the α5 integrin subunit compromises temozolomide-induced tumor suppressor p53 activity in human glioblastoma cells. We found that depletion of the α5 integrin subunit increased p53 activity and temozolomide sensitivity. However, when cells were treated with the p53 activator nutlin-3a, the protective effect of α5 integrin on p53 activation and cell survival was lost. In a functional p53 background, nutlin-3a downregulated the α5 integrin subunit, thereby increasing the cytotoxic effect of temozolomide. Clinically, α5β1 integrin expression was associated with a more aggressive phenotype in brain tumors, and high α5 integrin gene expression was associated with decreased survival of patients with high-grade glioma. Taken together, our findings indicate that negative cross-talk between α5β1 integrin and p53 supports glioma resistance to temozolomide, providing preclinical proof-of-concept that α5β1 integrin represents a therapeutic target for high-grade brain tumors. Direct activation of p53 may remain a therapeutic option in the subset of patients with high-grade gliomas that express both functional p53 and a high level of α5β1 integrin. Cancer Res; 72(14); 3463–70. ©2012 AACR.

International audience; Breast cancer is the most prevalent cancer in women. The development of resistances to therapeutic agents and the absence of targeted therapy for triple negative breast cancer motivate the search for alternative treatments. With this aim in mind, we synthesised new derivatives of troglitazone, a compound which was formerly used as an anti-diabetic agent and which exhibits anti-proliferative activity on various cancer cell lines. Among the compounds prepared, some displayed micromolar activity against hormone-dependent and hormone-independent breast cancer cells. Furthermore, the influence of the compounds on the viability of primary cultures of human hepatocytes was evaluated. This enabled us to obtain for the first time interesting structure-toxicity relationships in this family of compounds, resulting in 6b and 8b, which show good anti-proliferative activities and poor toxicity towards hepatocytes, compared to troglitazone.

International audience; Seminoma, originated from carcinoma in situ cells (CIS), is one of the main causes of cancer in young men. Postpubertal development of these testicular germ cell tumors suggests a hormone-sensitive way of CIS cell proliferation induction. Using the unique seminoma TCam-2 cell line, we demonstrate that both estradiol and testosterone can stimulate TCam-2 cell proliferation in the absence of the estradiol receptor ERα. We establish that estradiol can activate GPER-cAMP/PKA signalling pathway. TCam-2 cells express ERα36, a truncated isoform of the canonical ERα receptor, the expression of which is rapidly induced after estrogen treatment in a GPER-dependent manner. ERα36 knockdown indicates that ERα36 is (i) a downstream target of E(2)-activated GPER/PKA/CREB pathway, (ii) required for estradiol-dependent EGFR expression, (iii) necessary for cell proliferation. Colocalization of ERα36 with cytoskeleton microfilaments suggests a role of estrogens in cell motility. Our results highlight the functional role of ERα36 in context of seminoma cell proliferation and the importance of testing ERα36 in vivo as a possible future prognostic marker.

International audience; Thiazolidinediones are agonists of the nuclear receptor Peroxisome Proliferator Activated Receptor gamma (PPARγ). These synthetic compounds are known for a long time to have anticancer potencies and numerous studies have been performed to understand their mechanism of action. An increasing amount of converging results indicate that most of these mechanisms appear in a PPARγ-independent manner. This was suggested by the observation of effects in cell types devoid of PPARγ and by the absence of correlation between agonist efficiencies and the intensity of the effects. The PPARγ-independence was demonstrated by various experimental approaches using PPARγ antagonists, RNA interference targeting PPARγ or thiazolidinedione derivatives devoid of PPARγ agonist activity. Here, we review the studies that describe PPARγ-independent changes including ionic changes (intracellular pH and Ca2+), reactive oxygen species production, Mitogen Activated Protein Kinases activation, endoplasmic reticulum stress and proteasomal degradation of key proteins. The relationships between these events that occur either early or late after thiazolidinedione exposure and their possible involvement in the antineoplastic effect are discussed. We conclude about the possibility to take advantage from these data to develop new thiazolidinedione derivatives usable as anticancer drugs.

International audience; Caveolin-1 plays a crucial role in the development of cancer and its progression. We previously reported that glioblastoma cells expressing low levels of caveolin-1 exerted a more aggressive phenotype than cells expressing high levels. Such phenotype was due to the induction of α(5) β(1) integrin subsequent to the depletion of caveolin-1. Caveolin-1 was identified as a transcriptional repressor of α(5) β(1) integrin. The current study was designed to identify in vitro, the molecular mechanisms by which caveolin-1 controls α(5) β(1) integrin expression and to determine if a negative correlation between caveolin-1 and α(5) β(1) integrins also exists in biopsies and xenografted human brain tumors. We showed that depletion of caveolin-1 lead to the activation of the TGFβ/TGFβRI/Smad2 pathway which in turn induced the expression of α(5) β(1) integrins. We showed that cells expressing the lowest levels of caveolin-1 but the highest levels of α(5) β(1) integrins and TGFβRI were the most sensitive to a α(5) β(1) integrin antagonist and a TGFβRI inhibitor. Screening human glioma biopsies and human glioblastoma xenografts, we isolated subgroups with either low levels of caveolin-1 but high levels of α(5) β(1) integrin and TGFβRI or high levels of caveolin-1 but low levels of α(5) β(1) integrin and TGFβRI. In conclusion, caveolin-1 controls α(5) β(1) integrin expression through the TGFβ/TGFβRI/Smad2 pathway. The status of caveolin-1/α(5) β(1) integrins/TGFβRI might be a useful marker of the tumor evolution/prognosis as well as a predictor of anti-TGFβ or anti-α(5) β(1) integrin therapies.

Published in Annales de Pathologie 31(5), Supplement, page S143; National audience; L'analyse des mutations KRAS est un paramètre primordial dans l'individualisation de la prise en charge thérapeutique des cancers colorectaux métastatiques (CCRm), notamment dans la sélection de la première ligne thérapeutique pouvant comporter un anticorps anti-EGFR. L'optimisation de cette analyse repose sur la mise en œuvre de techniques de biologie moléculaire robustes et rapides permettant la réduction des délais de transmission des résultats d'analyse. L'étude porte sur 790 CCRm analysés entre janvier 2008 et décembre 2009. Après prescription de la recherche de mutations KRAS, les échantillons tumoraux fixés et inclus en paraffine ont été transmis par les pathologistes hospitaliers ou privés ayant assuré le diagnostic dans un délai moyen de 7,5 jours. Après analyse histopathologique (coloration HES), les échantillons ont été macrodisséqués pour assurer un contenu en matériel tumoral supérieur à 20 %. L'ADN est ensuite extrait à partir de 5 coupes de 10 μm d'épaisseur. Les mutations KRAS (codons 12 et 13 de l'exon 2) ont été recherchées par 3 techniques : 2 techniques " rapides " HRM (high resolution melting), discrimination allélique (PCR TaqMan) et une " lente " PCR-RFLP avec double digestion enzymatique. Sur les 790 échantillons, une corrélation statistiquement significative est observée entre les 3 techniques (κ > 0,9, p < 0,001). Une dégradation excessive de l'ADN empêchant l'analyse a été observée dans 2,8 % (22/790) des cas. Les mutations KRAS recherchées ont été détectées dans 40,6 % (310/768) des échantillons analysables, 82,3 % (255/310) au niveau du codon 12 et 18 % (55/310) au niveau du codon 13. Parmi les 549 échantillons pour lesquels les 3 techniques ont été utilisées, 15 cas (2,7 %) de discordance entre les 3 techniques ont été relevés. Dans ces cas, la répétition de la procédure complète, à partir de l'extraction de l'ADN a révélé que 47 % des discordances étaient imputables à la RFLP, 36 % à la technique TaqMan, 18 % à l'HRM. À partir de ces résultats, afin de réduire la durée de l'analyse et de mettre à la disposition des prescripteurs le résultat dans un délai optimal, l'HRM et la PCR TaqMan ont été utilisées en première intention et la PCR-RFLP en recours, en cas de discordance. Cette nouvelle procédure a permis d'assurer la transmission des résultats en 8,5 jours en moyenne contre 10,5 jours pour l'ancienne procédure. Cette procédure optimisée permet aux prescripteurs envisageant le recours à un anticorps anti-EGFR en première ligne, d'effectuer ce choix sur une base rationnelle c'est-à-dire en disposant du statut KRAS.

Contact: cabello@supagro.inra.fr; International audience; We have previously shown that mitochondrial protein synthesis regulates myoblast differentiation, partly through the control of c-Myc expression, a cellular oncogene regulating myogenin expression and myoblast withdrawal from the cell cycle. In this study we provide evidence of the involvement of Calcineurin in this regulation. In C2C12 myoblasts, inhibition of mitochondrial protein synthesis by chloramphenicol decreases Calcineurin expression. Conversely, stimulation of this process by overexpressing the T3 mitochondrial receptor (p43) increases Calcineurin expression. Moreover, expression of a constitutively active Calcineurin (ΔCN) stimulates myoblast differentiation, whereas a Calcineurin antisense has the opposite effect. Lastly, ΔCN expression or stimulation of mitochondrial protein synthesis specifically increases slow myosin heavy chain expression. In conclusion, these data clearly suggest that, partly via Calcineurin expression, mitochondrial protein synthesis is involved in muscle development through the control of myoblast differentiation and probably the acquisition of the contractile and metabolic phenotype of muscle fibres.

International audience; The SOX family of transcription factors is thought to regulate gene expression in a wide variety of developmental processes. Namely, SOX9 expression is conserved in vertebrate sex determination or differentiation. Nevertheless, information about caudate amphibians is lacking. In this study, we provide data on Pleurodeles waltl, a species that displays a ZZ/ZW genetic mode of sex determination and a temperature-dependent mechanism of female-to-male sex reversal. Phylogenetic analysis of SOX9 P. waltl ortholog reveals that the deduced protein segregates from the group of anuran and could be more closely related to amniote than to anamniote. However, SOX9 lacks the PQA-rich domain present in amniotes. In larvae, SOX9 is expressed in both sexes in gonad-mesonephros complexes as soon as stage 42, before gonad differentiation. At stage 54(60d) at which testis differentiation is already in progress, analyses of isolated gonads reveal a male-enriched expression of SOX9, which was quantified by real-time PCR. At the end of metamorphosis (stage 56), SOX9 shows a nuclear localization only in the testis. In adults, SOX9 is still expressed in testes and ovaries. In the ovary, SOX9 is found in oocytes from stage I to stage VI but it is never detected in the nucleus. Our results suggest that in P. waltl, like in non mammalian vertebrates, SOX9 could play a role during the late phase of gonad differentiation rather than in sex determination. Its role in germ cells of the adult ovary has still to be elucidated.

Publisher Summary This chapter reviews sex determination and differentiation in amphibians. The class amphibia is composed of three orders: Anura, Caudata, and Gymnophiona. The order Anura (more than 4500 species) includes frogs and toads; caudate order comprises salamanders, newts, sirens, amphiuma, waterdogs, and mudpuppies; and gymnophiona is the least studied and consists of caecilians that resemble giant earthworms rather than typical amphibians. The chapter describes the genetic sex determination and a wide variety of mechanisms regulate sex determination/differentiation in amphibians, which is associated with sex chromosomes that display various patterns, from homomorphism to heteromorphism. Gonadal differentiation is also discussed. The general features leading the undifferentiated gonad to differentiate as an ovary or a testis appear to be similar in anurans and caudates, but the origin of germ cells is very different. It also focuses on sensitivity to temperature, a factor that can induce sex reversal in several species by modulating steroid hormone synthesis. These molecules are indeed major players in the sex differentiation process.

International audience; The main objective of this study was to prepare two types of nanoparticles with poly(d,l-lactide-co-glycolide) (PLGA) and polyethylenimine (PEI) polymers. Plasmid DNA (pDNA) was adsorbed either on PLGA/PEI nanoparticles, or as PEI/DNA complex onto the surface of PLGA nanoparticles. Both types of nanoparticles were prepared by the double emulsion method. The nanoparticles were characterized by their size, zeta potential and pDNA or PEI/DNA complex adsorption. The PEI/DNA complex adsorption was confirmed with ethidium bromide assay. pDNA adsorption onto PLGA/PEI nanoparticles (PLGA/PEI-DNA) was studied by electrophoresis on agarose gel. Cytotoxicity and transfection efficiency of both types of nanoparticle and PEI/DNA complexes formulations were studied in head and neck squamous carcinoma cell line (FaDu). To improve endosomal release, photochemical internalization (PCI) was used. The zeta potential increased when the PEI/DNA complex adsorbed onto PLGA nanoparticles (PLGA-PEI/DNA). Optimal pDNA adsorption efficiency was achieved for nitrogen/phosphorous ratio ≥ 20/1. In vitro transfection and cells viability on FaDu cells with or without PCI were found to be variable depending on the type and concentration of nanoparticles. The results showed that transfection efficiency for PLGA/PEI-DNA or PLGA-PEI/DNA nanoparticles ranged between 2 and 80%, respectively. PCI was found to slightly improve the transfection efficiency for all formulations.

International audience; The general strategy developed aims to favor the vascular effect of photodynamic therapy by targeting tumor vasculature. Since angiogenic endothelial cells represent an interesting target to potentiate this vascular effect, we previously described the conjugation of a photosensitizer to a peptide targeting neuropilins (NRPs) over-expressed specially in tumor angiogenic vessels and we recently characterized the mechanism of photosensitization-induced thrombogenic events. Nevertheless, in glioma-bearing nude mice, we demonstrated that the peptide moiety was degraded to various rates according to time after intravenous administration. In this study, new peptidases-resistant pseudopeptides were tested, demonstrating a molecular affinity for NRP-1 and NRP-2 recombinant chimeric proteins and devoid of affinity for VEGF receptor type 1 (Flt-1 To argue the involvement of NRP-1, MDA-MB-231 breast cancer cells were used, strongly over-expressing NRP-1 receptor. We evidenced a statistically significant decrease of the different peptides-conjugated photosensitizers uptake after RNA interference-mediated silencing of NRP-1. Peptides-conjugated photosensitizers allowed a selective accumulation into cells. In mice, no degradation was observed in plasma in vivo 4 h after intravenous injection by MALDI-TOF mass spectrometry. This study draws attention to this potential problem with peptides, especially in the case of targeting strategies, and provides useful information for the future design of more stable molecules.

Alcohol consumption is known to be an increased risk factor for breast cancer, but the underlying molecular mechanisms are not well understood. We have recently shown that the exposure of MCF-7 breast cancer cells to 0.1% ethanol enhanced their proliferation and increased their content in both estrogen receptor-alpha (ERalpha) and aromatase. The aim of the present work was to determine if the effects of ethanol could be mimicked by other short-chain aliphatic alcohols such as methanol and 1-butanol. Our results show that these compounds do not stimulate MCF-7 cell proliferation. An increase in ERalpha content was observed by Western blot in methanol-treated cells, but this parameter was not affected in butanol-treated cells. Neither of these two alcohols induced an increase in aromatase mRNA level. So despite a similarity in molecular structure, these primary alcohols do not exert the same effects. Taken together, these results suggest that the increase in aromatase expression might be a key event required for the enhanced proliferation observed in the presence of ethanol.

International audience; PURPOSE: Beside its efficacy in cancer treatment, radiotherapy induces degeneration of healthy tissues within the irradiated area. The aim of this study was to analyze the variations of proinflammatory (IL-1α, IL-2, IL-6, TNF-α, IFN-γ), profibrotic (TGF-β1), proangiogneic (VEGF) and stem cell mobilizing (GM-CSF) cytokines and growth factors in an animal model of radiation-induced tissue degeneration. MATERIALS AND METHODS: 24 rats were irradiated unilaterally on the hindlimb at a monodose of 30 Gy. Six weeks (n=8), 6 months (n=8) and 1 year (n=8) after irradiation the mediators expression in skin and muscle were analyzed using Western blot and the Bio-Plex® protein array (BPA) technology. Additional histological severity for fibrosis, inflammation, vascularity and cellularity alterations scoring was defined from histology and immnunohistochemistry analyses. RESULTS: A significant increase of histological severity scoring was found in irradiated tissue. Skin tissues were more radio-sensitive than muscle. A high level of TGF-β1 expression was found throughout the study and a significant relation was evidenced between TGF-β1 expression and fibrosis scoring. Irradiated tissue showed a chronic inflammation (IL-2 and TNF-α significantly increased). Moreover a persistent expression of GM-CSF and VEGF was found in all irradiated tissues. The vascular score was related to TGF-β1 expression and the cellular alterations score was significantly related with the level of IL-2, VEGF and GM-CSF. CONCLUSION: The results achieved in the present study underline the complexity and multiplicity of radio-induced alterations of cytokine network. It offers many perspectives of development, for the comprehension of the mechanisms of late injuries or for the histological and molecular evaluation of the mode of action and the efficacy of rehabilitation techniques.