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1.
Occup Environ Med ; 80(7): 392-398, 2023 07.
Article En | MEDLINE | ID: mdl-37230753

OBJECTIVES: Asthma has significant occupational consequences. The objective of our study was to investigate the links between asthma and the career path, taking into account gender and age at asthma onset. METHODS: Using cross-sectional data collected at inclusion in the French CONSTANCES cohort in 2013-2014, we studied the links between each career path indicator (number of job periods, total duration of employment, numbers of part-time jobs and work interruptions due to unemployment or health issues, employment status at inclusion) on the one hand, and current asthma and asthma symptom score in the last 12 months on the other hand, as reported by the participants. Multivariate analyses were performed separately for men and women using logistic and negative binomial regression models adjusted for age, smoking status, body mass index and educational level. RESULTS: When the asthma symptom score was used, significant associations were observed with all of the career path indicators studied: a high symptom score was associated with a shorter total duration of employment as well as a greater number of job periods, part-time jobs and work interruptions due to unemployment or health issues. These associations were of similar magnitude in men and women. When current asthma was used, the associations were more pronounced in women for some career path indicators. CONCLUSION: The career path of asthmatic adults is more often unfavourable than that of those without asthma. Efforts should be made to support people with asthma in the workplace, in order to maintain employment and facilitate the return to work.


Asthma , Employment , Adult , Male , Humans , Female , Cross-Sectional Studies , Unemployment , Workplace , Asthma/epidemiology
2.
Eur J Endocrinol ; 187(5): 675-683, 2022 Nov 01.
Article En | MEDLINE | ID: mdl-36074933

Objective: Childhood hyperthyroidism is mostly caused by Graves' disease, a rare autoimmune disease in children. Epidemiological data are scarce and the variability of within-region incidence is unknown. We aimed to provide the first description of temporal trends in pediatric hyperthyroidism in France and to explore spatial trends, with a view to identifying possible environmental triggers. Design and methods: We performed an observational population-based study on data collected from the National Health Data System, covering the 2008-2017 period and the whole of France. We identified patients with an indicator reflecting incident cases of treated hyperthyroidism, in children aged 6 months-17.9 years, localized at the scale of the département (equivalent to a county) of residence. We performed descriptive analyses of incidence rate by sex, age, and year, and used a spatiotemporal model for estimation at département level. Results: We identified 4734 incident cases: 3787 girls (80%) and 947 boys (20%). The crude incidence rate was 3.35 (95% CI: 3.26; 3.45) per 100 000 person-years over the study period. We estimated the increase in incidence between 2008 and 2017 at 30.1% (19.0%; 42.3%). Annual incidence rate increased linearly over the 10-year period in both girls and boys, rising similarly in all age groups and in all départements. The spatial model highlighted marked heterogeneity in the risk of childhood hyperthyroidism across France. Conclusion: The trend toward increasing incidence observed may reflect changes in genetic and environmental interactions, and the marked spatial heterogeneity may reflect localized ethnic or environmental factors worthy of further investigation.


Autoimmune Diseases , Graves Disease , Hyperthyroidism , Child , Ethnicity , Female , Graves Disease/epidemiology , Humans , Hyperthyroidism/epidemiology , Incidence , Male
3.
Sci Rep ; 12(1): 6966, 2022 04 28.
Article En | MEDLINE | ID: mdl-35484205

Endometriosis is a female hormone-dependent disease, possibly related to endocrine disruptor exposure. We aimed to monitor this disease nationwide in France and analyze spatial trends at a fine scale to explore possible environmental contributing risk factors. We conducted a retrospective national descriptive study from 2011 to 2017 in females aged 10 years old and over, using comprehensive hospital discharge data. Cases were identified using ICD-10 N80 codes and were localized at their municipality of residence. We defined incident cases as the first hospital stay of patients, without a stay in at least the previous 5 years. We performed statistical analyses according to age and type of endometriosis, and we modeled the temporal, spatial and spatiotemporal trends. We identified 207,462 incident cases of all-type hospitalized endometriosis (83,112 for non-adenomyosis cases). The crude incidence rate for the study period was 9.85/10,000 person-years (3.95/10,000 for non-adenomyosis cases). From 2011 to 2017, the risk of all-type endometriosis increased by 8.5% (95% CI: 3.9; 13.4) (by 3.6% (95% CI: 0.6; 6.8) for non-adenomyosis cases). The risk was geographically heterogeneous, with 20 high-risk hotspots, showing similar results for non-adenomyosis cases. Shifting practice patterns, improved awareness and healthcare disparities interlinked with environmental risk factors could explain these trends.


Endometriosis , Child , Endometriosis/epidemiology , Female , Hospitalization , Humans , Incidence , Length of Stay , Retrospective Studies
4.
Euro Surveill ; 26(34)2021 08.
Article En | MEDLINE | ID: mdl-34448447

BackgroundWaterborne disease outbreaks (WBDO) associated with tap water consumption are probably underestimated in France.AimIn order to improve their detection, Santé publique France launched a surveillance system in 2019, based on the periodical analysis of health insurance data for medicalised acute gastroenteritis (mAGE).MethodsSpatio-temporal cluster detection methods were applied to mAGE cases to prioritise clusters for further investigation. These investigations determined the plausibility that infection is of waterborne origin and the strength of association.ResultsBetween January 2010 and December 2019, 3,323 priority clusters were detected (53,878 excess mAGE cases). They involved 3,717 drinking water supply zones (WSZ), 15.4% of all French WSZ. One third of these WSZ (33.4%; n = 1,242 WSZ) were linked to repeated clusters. Moreover, our system detected 79% of WBDO voluntarily notified to health authorities.ConclusionEnvironmental investigations of detected clusters are necessary to determine the plausibility that infection is of waterborne origin. Consequently, they contribute to identifying which WSZ are linked to clusters and for which specific actions are needed to avoid future outbreaks. The surveillance system incorporates three priority elements: linking environmental investigations with water safety plan management, promoting the systematic use of rainfall data to assess waterborne origin, and focusing on repeat clusters. In the absence of an alternative clear hypothesis, the occurrence of a mAGE cluster in a territory completely matching a distribution zone indicates a high plausibility of water origin.


Gastroenteritis , Waterborne Diseases , Disease Outbreaks , Gastroenteritis/epidemiology , Humans , Population Surveillance , Water Microbiology , Water Supply , Waterborne Diseases/epidemiology
5.
Article En | MEDLINE | ID: mdl-32560168

The French national public health agency (Santé publique France) has used data from the national health insurance reimbursement system (SNDS) to identify medicalised acute gastroenteritis (mAGE) for more than 10 years. This paper presents the method developed to evaluate this system: performance and characteristics of the discriminatory algorithm, portability in mainland and overseas French departments, and verification of the mAGE database updating process. Pharmacy surveys with certified mAGE from 2012 to 2015 were used to characterise mAGE and to estimate the sensitivity and predictive positive value (PPV) of the algorithm. Prescription characteristics from these pharmacy surveys and from 2014 SNDS prescriptions in six mainland and overseas departments were compared. The sensitivity (0.90) and PPV (0.82) did not vary according to the age of the population or year. Prescription characteristics were similar within all studied departments. This confirms that the algorithm can be used in all French departments, for both paediatric and adult populations, with stability and durability over time. The algorithm can identify mAGE cases at a municipal level. The validated system has been implemented in a national waterborne disease outbreaks surveillance system since 2019 with the aim of improving the prevention of infectious disease risk attributable to localised tap water systems.


Gastroenteritis , Insurance, Health , Sentinel Surveillance , Adolescent , Adult , Algorithms , Child , Child, Preschool , Drug Prescriptions/statistics & numerical data , France/epidemiology , Gastroenteritis/drug therapy , Gastroenteritis/epidemiology , Humans , Population Surveillance
6.
Environ Sci Pollut Res Int ; 27(33): 41033-41045, 2020 Nov.
Article En | MEDLINE | ID: mdl-31884530

Agricultural activities in the Caribbean, especially banana cropping, are known for their significant use of pesticides. In particular is chlordecone, which was used between 1972 and 1993 against the banana root borer, Cosmopolites sordidus (Germar, 1824). In this context, "Kannari study: Health, Nutrition and Exposition to Chlordecone in French West Indies" was put in place in 2013-2014 to supplement knowledge about the exposure of the population to chlordecone and other organochlorine pollutants. The data collected comprised a dietary intake description, data from biological samples (blood sample), socioeconomic and demographic information, and data from complementary specific items relative to life habits. A total of 742 subjects (292 in Guadeloupe and 450 in Martinique) were included in the impregnation component of the Kannari study. In this study, chlordecone and organochlorine compounds were detected in almost all participants. This result suggests that exposure to chlordecone is widespread, but also to other organochlorine pesticides. Chlordecone impregnation of the majority of the population appears to have decreased between 2003 and 2013, but various subgroups of the population remain highly exposed. The levels of impregnation are determined by dietary exposure and environmental contamination. However, total consumption of fresh fish (all species combined), especially from informal channels, is the main source of exposure to chlordecone. The serum PCB concentrations measured in the French Caribbean Islands of Guadeloupe and Martinique are lower than those observed in metropolitan France in 2007 (French Nutrition and Health Survey (ENNS)). In contrast, the French West Indies population seems more exposed to lindane than the French mainland population, and this exposure also seems more recent.


Chlordecone , Hydrocarbons, Chlorinated , Insecticides , Animals , Caribbean Region , Chlordecone/analysis , France , Guadeloupe , Humans , Insecticides/analysis , Martinique , West Indies
7.
Am J Cancer Res ; 6(3): 677-89, 2016.
Article En | MEDLINE | ID: mdl-27152244

Osteosarcoma, the most frequent malignant primary bone tumor in pediatric patients is characterized by osteolysis promoting tumor growth. Lung metastasis is the major bad prognosis factor of this disease. Zoledronic Acid (ZA), a potent inhibitor of bone resorption is currently evaluated in phase III randomized studies in Europe for the treatment of osteosarcoma and Ewing sarcoma. The beneficial effect of the liposomal form of Muramyl-TriPeptide-Phosphatidyl Ethanolamine (L-mifamurtide, MEPACT®), an activator of macrophage populations has been demonstrated to eradicate lung metastatic foci in osteosarcoma. The objective of this study was to evaluate the potential therapeutic benefit and the safety of the ZA and L-mifamurtide combination in preclinical models of osteosarcoma, as a prerequisite before translation to patients. The effects of ZA (100 µg/kg) and L-mifamurtide (1 mg/kg) were investigated in vivo in xenogeneic and syngeneic mice models of osteosarcoma, at clinical (tumor proliferation, spontaneous lung metastases development), radiological (bone microarchitecture by microCT analysis), biological and histological levels. No interference between the two drugs could be observed on ZA-induced bone protection and on L-mifamurtide-induced inhibition of lung metastasis development. Unexpectedly, ZA and L-mifamurtide association induced an additional and in some cases synergistic inhibition of primary tumor progression. L-mifamurtide has no effect on tumor proliferation in vitro or in vivo, and macrophage population was not affected at the tumor site whatever the treatment. This study evidenced for the first time a significant inhibition of primary osteosarcoma progression when both drugs are combined. This result constitutes a first proof-of-principle for clinical application in osteosarcoma patients.

8.
Molecules ; 21(3): 309, 2016 Mar 04.
Article En | MEDLINE | ID: mdl-26959001

Osteosarcoma is the most frequent malignant primary bone tumor characterized by a high potency to form lung metastases. In this study, the effect of three oversulfated low molecular weight marine bacterial exopolysaccharides (OS-EPS) with different molecular weights (4, 8 and 15 kDa) were first evaluated in vitro on human and murine osteosarcoma cell lines. Different biological activities were studied: cell proliferation, cell adhesion and migration, matrix metalloproteinase expression. This in vitro study showed that only the OS-EPS 15 kDa derivative could inhibit the invasiveness of osteosarcoma cells with an inhibition rate close to 90%. Moreover, this derivative was potent to inhibit both migration and invasiveness of osteosarcoma cell lines; had no significant effect on their cell cycle; and increased slightly the expression of MMP-9, and more highly the expression of its physiological specific tissue inhibitor TIMP-1. Then, the in vivo experiments showed that the OS-EPS 15 kDa derivative had no effect on the primary osteosarcoma tumor induced by osteosarcoma cell lines but was very efficient to inhibit the establishment of lung metastases in vivo. These results can help to better understand the mechanisms of GAGs and GAG-like derivatives in the biology of the tumor cells and their interactions with the bone environment to develop new therapeutic strategies.


Antineoplastic Agents/isolation & purification , Antineoplastic Agents/pharmacology , Polysaccharides, Bacterial/pharmacology , Animals , Aquatic Organisms/chemistry , Bone Neoplasms/drug therapy , Bone Neoplasms/metabolism , Bone Neoplasms/pathology , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Cell Survival/drug effects , Glycosaminoglycans/pharmacology , Humans , Lung Neoplasms/prevention & control , Lung Neoplasms/secondary , Male , Matrix Metalloproteinases/metabolism , Mice , Mice, Inbred C3H , Mice, Nude , Molecular Mimicry , Neoplasm Invasiveness/prevention & control , Osteosarcoma/drug therapy , Osteosarcoma/pathology , Osteosarcoma/secondary , Tissue Inhibitor of Metalloproteinases/metabolism
9.
Bone ; 73: 51-9, 2015 Apr.
Article En | MEDLINE | ID: mdl-25532478

High doses of bone resorption inhibitors are currently under evaluation in pediatric oncology. Previous works have evidenced transient arrest in long bone and skull bone growth and tooth eruption blockage when mice were treated with zoledronic acid (ZOL). The question of potential similar effects with a RANKL-blocking antibody (IK22.5) was raised. Sensitivity disparities in these inhibitors between mouse strains and synergic effects of zoledronic acid and a RANKL-blocking antibody were subsidiary questions. In order to answer these questions, newborn C57BL/6J and CD1 mice were injected every two or three days (4 injections in total so 7 or 10 days of treatment length) with high doses of a RANKL-blocking antibody. The consequences on the tibia, craniofacial bones and teeth were analyzed by µCT and histology at the end of the treatment and one, two and three months later. The results obtained showed that RANKL-blocking antibody injections induced a transient arrest of tibia and skull bone growth and an irreversible blockage of tooth eruption in C57BL/6J mice. In CD1 mice, tooth eruption defects were also present but only at much higher doses. Similar mouse strain differences were obtained with zoledronic acid. Finally, a synergic effect of the two inhibitors was evidenced. In conclusion as previously observed for bisphosphonates (ZOL), a RANKL-blocking antibody induced a transient arrest in long bone and skull bone growth and a blockage of tooth eruption with however disparities between mouse strains with regard to this last effect. A synergic effect of both bone resorption inhibitors was also demonstrated.


Antibodies/administration & dosage , Bone Density Conservation Agents/pharmacology , Bone Development/immunology , Diphosphonates/pharmacology , Imidazoles/pharmacology , RANK Ligand/immunology , Animals , Animals, Newborn , Antibodies/immunology , Bone Development/drug effects , Female , Mice , Mice, Inbred C57BL , Pregnancy , Tooth Eruption/immunology , Zoledronic Acid
10.
Bone ; 68: 146-52, 2014 Nov.
Article En | MEDLINE | ID: mdl-25193159

High doses of zoledronic acid (ZOL), one of the most potent inhibitors of bone resorption, are currently evaluated in phase III clinical trials in Europe for the treatment of malignant pediatric primary bone tumors. The impact of such an intensive treatment on the craniofacial skeleton growth is a critical question in the context of patients with actively growing skeleton; in particular, in light of our previous studies evidencing that endochondral bone formation was transiently disturbed by high doses of ZOL. Two protocols adapted from pediatric treatments were developed for newborn mice (a total of 5 or 10 injections of ZOL 50µg/kg every two days). Their impact on skull bones and teeth growth was analyzed by X-rays, microCT and histology up to 3months after the last injection. ZOL administrations induced a transient delay of skull bone growth and an irreversible delay in incisor, first molar eruption and root elongation. Other teeth were affected, but most were erupted by 3months. Root histogenesis was severely impacted for all molars and massive odontogenic tumor-like structures were observed in all mandibular incisors. High doses of ZOL irreversibly disturbed teeth eruption and elongation, and delayed skull bone formation. These preclinical observations are essential for the follow-up of onco-pediatric patients treated with ZOL.


Bone Neoplasms/drug therapy , Craniofacial Abnormalities/chemically induced , Diphosphonates/therapeutic use , Imidazoles/therapeutic use , Animals , Animals, Newborn , Bone Development/drug effects , Child , Craniofacial Abnormalities/diagnostic imaging , Craniofacial Abnormalities/pathology , Female , Humans , Mice, Inbred C57BL , Phenotype , Tibia/diagnostic imaging , Tibia/drug effects , Tibia/pathology , X-Ray Microtomography , Zoledronic Acid
11.
Clin Cancer Res ; 20(19): 5097-112, 2014 Oct 01.
Article En | MEDLINE | ID: mdl-25107916

PURPOSE: Osteosarcoma is the main malignant primary bone tumor in children and adolescents for whom the prognosis remains poor, especially when metastasis is present at diagnosis. Because transforming growth factor-ß (TGFß) has been shown to promote metastasis in many solid tumors, we investigated the effect of the natural TGFß/Smad signaling inhibitor Smad7 and the TßRI inhibitor SD-208 on osteosarcoma behavior. EXPERIMENTAL DESIGN: By using a mouse model of osteosarcoma induced by paratibial injection of cells, we assessed the impact of Smad7 overexpression or SD-208 on tumor growth, tumor microenvironment, bone remodeling, and metastasis development. RESULTS: First, we demonstrated that TGFß levels are higher in serum samples from patients with osteosarcoma compared with healthy volunteers and that TGFß/Smad3 signaling pathway is activated in clinical samples. Second, we showed that Smad7 slows the growth of the primary tumor and increases mice survival. We furthermore demonstrated that Smad7 expression does not affect in vitro osteosarcoma cell proliferation but affects the microarchitectural parameters of bone. In addition, Smad7-osteosarcoma bone tumors expressed lower levels of osteolytic factors such as RANKL, suggesting that Smad7 overexpression affects the "vicious cycle" established between tumor cells and bone cells by its ability to decrease osteoclast activity. Finally, we showed that Smad7 overexpression in osteosarcoma cells and the treatment of mice with SD208 inhibit the development of lung metastasis. CONCLUSION: Taken together, these results demonstrate that the inhibition of the TGFß/Smad signaling pathway may be a promising therapeutic strategy against tumor progression of osteosarcoma, specifically against the development of lung metastasis.


Bone Neoplasms/genetics , Bone Neoplasms/pathology , Gene Expression , Lung Neoplasms/secondary , Osteosarcoma/genetics , Osteosarcoma/pathology , Smad7 Protein/genetics , Animals , Bone Neoplasms/metabolism , Bone Neoplasms/mortality , Bone Resorption/genetics , Cell Line, Tumor , Disease Models, Animal , Female , Heterografts , Humans , Mice , Osteoclasts/drug effects , Osteoclasts/metabolism , Osteosarcoma/metabolism , Osteosarcoma/mortality , Pteridines/pharmacology , Signal Transduction/drug effects , Smad3 Protein/metabolism , Smad7 Protein/metabolism , Transforming Growth Factor beta/blood , Tumor Burden/genetics
12.
Cancer Lett ; 344(2): 291-8, 2014 Mar 28.
Article En | MEDLINE | ID: mdl-24333720

Despite recent improvements in chemotherapy and surgery, the problem of non-response osteosarcoma to chemotherapy remains, and is a parameter that is critical for prognosis. The present work investigated the therapeutic value of NVP-BEZ235, a dual class I PI3K/mTOR inhibitor. NVP-BEZ235 inhibited osteosarcoma cell proliferation by inducing G0/G1 cell cycle arrest with no caspase activation. In murine pre-clinical models, NVP-BEZ235 significantly slowed down tumor progression and ectopic tumor bone formation with decreased numbers of Ki67(+) cells and reduced tumor vasculature. Finally, NVP-BEZ235 considerably improved the survival rate of mice with osteosarcoma. Taken together, the results of the present work show that NVP-BEZ235 exhibits therapeutic interest in osteosarcoma and may be a promising adjuvant drug for bone sarcomas.


Antineoplastic Agents/pharmacology , Bone Neoplasms/drug therapy , Imidazoles/pharmacology , Osteosarcoma/drug therapy , Phosphoinositide-3 Kinase Inhibitors , Quinolines/pharmacology , TOR Serine-Threonine Kinases/antagonists & inhibitors , Animals , Bone Neoplasms/enzymology , Bone Neoplasms/pathology , Cell Growth Processes/drug effects , Cell Line, Tumor , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Nude , Osteosarcoma/enzymology , Osteosarcoma/pathology , Phosphatidylinositol 3-Kinases/metabolism , Random Allocation , TOR Serine-Threonine Kinases/metabolism , Xenograft Model Antitumor Assays
13.
PLoS One ; 8(11): e80054, 2013.
Article En | MEDLINE | ID: mdl-24278237

The MSX2 homeoprotein is implicated in all aspects of craniofacial skeletal development. During postnatal growth, MSX2 is expressed in all cells involved in mineralized tissue formation and plays a role in their differentiation and function. Msx2 null (Msx2 (-/-)) mice display complex craniofacial skeleton abnormalities with bone and tooth defects. A moderate form osteopetrotic phenotype is observed, along with decreased expression of RANKL (TNFSF11), the main osteoclast-differentiating factor. In order to elucidate the role of such an osteopetrosis in the Msx2 (-/-) mouse dental phenotype, a bone resorption rescue was performed by mating Msx2 (-/-) mice with a transgenic mouse line overexpressing Rank (Tnfrsf11a). Msx2 (-/-) Rank(Tg) mice had significant improvement in the molar phenotype, while incisor epithelium defects were exacerbated in the enamel area, with formation of massive osteolytic tumors. Although compensation for RANKL loss of function could have potential as a therapy for osteopetrosis, but in Msx2 (-/-) mice, this approach via RANK overexpression in monocyte-derived lineages, amplified latent epithelial tumor development in the peculiar continuously growing incisor.


Homeodomain Proteins/physiology , Osteopetrosis/physiopathology , RANK Ligand/physiology , Tooth , Animals , Base Sequence , DNA Primers , Homeodomain Proteins/genetics , Mice , Mice, Knockout , Phenotype , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , X-Ray Microtomography
14.
Eur J Cancer ; 49(9): 2253-63, 2013 Jun.
Article En | MEDLINE | ID: mdl-23490646

BACKGROUND: Osteosarcoma is the most common primary malignant bone tumour in children and adolescents for whom the prognosis remains unfavourable despite treatment protocols that combine chemotherapy and surgery. Metalloproteinases decisively contribute to cancer development and promotion by regulating cell growth, angiogenesis or inflammation. However, their role in osteosarcoma remains still unknown. METHODS: A screening of a large panel of metalloproteinases and their inhibitors, carried out in osteolytic (K7M2 and POS-1) or osteoblastic (MOS-J) mouse osteosarcoma models, shows that a member of a family of cell surface metallopeptidases, A Disintegrin And Metalloproteinase 12 (ADAM12), is highly expressed in the K7M2 and POS-1 cell lines and weakly expressed in the MOS-J cell line. To investigate whether ADAM12, involved in several pathologic conditions characterised by abnormal cell growth, plays a role in osteosarcoma tumour growth, ADAM12 was overexpressed in MOS-J and downregulated in K7M2 cells. RESULTS: In vivo experiments demonstrated that ADAM12 favours tumour growth, leading to a significant modification in animal survival. In vitro assays showed that ADAM12 knockdown in K7M2 cells slows cell proliferation. In addition, the study of microarchitectural parameters, assessed by micro-computed tomography (CT) analysis, showed that ADAM12 favours bone osteolysis, as demonstrated both in an ADAM12 overexpressing (MOS-J) and a knockdown (K7M2) model. Histological analysis showed that ADAM12 inhibited osteoblast activity and therefore enhanced bone resorption. CONCLUSIONS: Our study demonstrates that ADAM12 expression not only favours tumour growth but also associates enhanced osteolysis with a significant reduction in animal survival, suggesting that ADAM12 could be a new therapeutic target in osteosarcoma.


ADAM Proteins/physiology , Bone Neoplasms/pathology , Membrane Proteins/physiology , Neoplasm Proteins/physiology , Osteolysis/pathology , Osteosarcoma/pathology , ADAM Proteins/metabolism , ADAM12 Protein , Adolescent , Adult , Animals , Bone Neoplasms/metabolism , Cell Proliferation , Disease Models, Animal , Disease Progression , Female , Gene Knockdown Techniques , Humans , Male , Membrane Proteins/metabolism , Mice , Mice, Inbred C57BL , Middle Aged , Neoplasm Proteins/metabolism , Osteolysis/metabolism , Osteosarcoma/metabolism , Transfection , Tumor Cells, Cultured , Young Adult
15.
Biochim Biophys Acta ; 1832(4): 553-64, 2013 Apr.
Article En | MEDLINE | ID: mdl-23313578

Ewing's sarcoma (ES) is a primary bone tumor characterized by a chromosomic translocation between the EWS gene and a member of the ETS gene family, mainly FLI1, which leads to an aberrant transcription factor EWS-FLI1 that promotes tumorigenicity. Gap junctions are intercellular channels composed of transmembrane proteins (connexin: Cx), that allow direct intercellular communication between adjacent cells. Numerous studies have shown that tumorigenesis may be associated with a loss of gap junctional intercellular communication (GJIC). Loss of Cx43 expression was observed at the protein and mRNA levels in ES cell lines compared to those measured in human mesenchymal stem cells. A673 ES cells stably transfected with an shRNA targeting EWS-FLI1 showed an increase in Cx43 expression (at the mRNA, protein and transcriptional levels) and GJIC. In an osteolytic murine model of ES, the overexpression of Cx43 in ES cells dramatically reduced tumor growth, leading to a significant increase in animal survival. In vitro assays showed that Cx43 overexpression increases the p27 level with an associated marked decrease of Rb phosphorylation, consistent with the observed blockade of the cell cycle in G0/G1 phase. In addition, the bone microarchitectural parameters, assessed by micro-CT analysis, showed an increased bone volume when Cx43 expression was enhanced. Histological analysis demonstrated that the overexpression of Cx43 in ES tumor cells inhibits osteoclast activity and therefore bone resorption. Our study demonstrated that the loss of Cx43 expression in ES cells plays a crucial role in the development of the primary tumor and the associated bone osteolysis.


Bone Neoplasms , Cell Transformation, Neoplastic , Connexin 43 , Sarcoma, Ewing , Bone Neoplasms/genetics , Bone Neoplasms/metabolism , Bone Neoplasms/pathology , Bone Neoplasms/secondary , Cell Communication , Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/metabolism , Connexin 43/genetics , Connexin 43/metabolism , Embryonic Stem Cells , Gap Junctions , Gene Expression Regulation, Neoplastic , Humans , Oncogene Proteins, Fusion/genetics , Osteolysis/genetics , Osteolysis/pathology , Proto-Oncogene Protein c-fli-1/genetics , RNA-Binding Protein EWS/genetics , Sarcoma, Ewing/genetics , Sarcoma, Ewing/metabolism , Sarcoma, Ewing/pathology
16.
J Bone Miner Res ; 26(10): 2439-51, 2011 Oct.
Article En | MEDLINE | ID: mdl-21713986

Osteosarcoma and Ewing sarcoma represent the two most frequent primary bone tumors that arise in the pediatric population. Despite recent improvement in their therapeutic management, no improvement in survival rate has been achieved since early 1980 s. Among new therapeutic approaches, bisphosphonates are promising candidates as potent inhibitors of bone resorption. However, their effects on bone growth must be studied at dosing regimen corresponding to pediatric protocols. To this aim, several protocols using zoledronic acid (ZOL) were developed in growing mice (50 µg/kg every 2 days × 10). Parameters of bone remodeling and bone growth were investigated by radiography, micro-computed tomography, histology, and biologic analyses. Extramedullar hematopoiesis was searched for in spleen tissue. A transient inhibitory effect of ZOL was observed on bone length, with a bone-growth arrest during treatment owing to an impressive increase in bone formation at the growth plate level (8- to 10-fold increase in BV/TV). This sclerotic band then shifted into the diaphysis as soon as endochondral bone formation started again after the end of ZOL treatment, revealing that osteoclasts and osteoblasts are still active at the growth plate. In conclusion, endochondral bone growth is transiently disturbed by high doses of ZOL corresponding to the pediatric treatment of primary bone tumors. These preclinical observations were confirmed by a case report in a pediatric patient treated in the French OS2006 protocol over 10 months who showed a growth arrest during the ZOL treatment period with normal gain in size after the end of treatment.


Bone Development/drug effects , Bone Neoplasms/drug therapy , Diphosphonates/therapeutic use , Imidazoles/therapeutic use , Osteosarcoma/drug therapy , Animals , Child , Diphosphonates/administration & dosage , Drug Evaluation, Preclinical , Female , Humans , Imidazoles/administration & dosage , Male , Mice , Mice, Inbred C57BL , Zoledronic Acid
17.
J Bone Miner Res ; 26(10): 2452-62, 2011 Oct.
Article En | MEDLINE | ID: mdl-21713988

The development of osteosarcoma, the most common malignant primary bone tumor is characterized by a vicious cycle established between tumor proliferation and paratumor osteolysis. This osteolysis is mainly regulated by the receptor activator of nuclear factor κB ligand (RANKL). Preclinical studies have demonstrated that Rankl blockade by soluble receptors is an effective strategy to prevent osteolytic lesions leading to osteosarcoma inhibition. A new therapeutic option could be to directly inhibit Rankl expression by small interfering RNAs (Rkl-siRNAs) and combine these molecules with chemotherapy to counteract the osteosarcoma development more efficiently. An efficient siRNA sequence directed against both mouse and rat mRNAs coding Rankl was first validated in vitro and tested in two models of osteosarcoma: a syngenic osteolytic POS-1 model induced in immunocompetent mice and a xenograft osteocondensant model of rat OSRGA in athymic mice. Intratumor injections of Rankl-directed siRNAs in combination with the cationic liposome RPR209120/DOPE reduced the local and systemic Rankl production and protected bone from paratumor osteolysis. Although Rkl-siRNAs alone had no effect on tumor development in both osteosarcoma models, it significantly blocked tumor progression when combined with ifosfamide compared with chemotherapy alone. Our results indicate that siRNAs could be delivered using cationic liposomes and thereby could inhibit Rankl production in a specific manner in osteosarcoma models. Moreover, the Rankl inhibition mediated by RNA interference strategy improves the therapeutic response of primary osteosarcoma to chemotherapy.


Antineoplastic Agents/therapeutic use , Osteolysis/genetics , Osteosarcoma/drug therapy , RANK Ligand/genetics , RNA, Small Interfering/genetics , Animals , Base Sequence , Blotting, Western , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Immunohistochemistry , Mice , Mice, Nude , Rats
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