Implication des métalloprotéinases de la matrice extracellulaire MMP-2 (gélatinase A) et MMP-9 (gélatinase B) dans les maladie inflammatoires chroniques des voies aériennes supérieures

Le but de cette thèse était l'étude de l'implication des métalloprotéinases de la matrice extracellulaire, MMP-2 et MMP-9 dans le remodelage des voies aériennes, par des approches in vivo et in vitro. Ce travail démontre que MMP-2 et MMP-9 sont faiblement exprimées à l'état basal. MMP-9 est sur-exprimée dans la polypose nasosinusienne, en particulier au niveau des cellules épithéliales. In vitro, en présence de TGFÇ3I, MMP-2 favorise la réparation épithéliale des voies aériennes. Ces résultats suggèrent que MMP-2 et MMP-9 moduleraient la réparation épithéliale et le remodelage des voies aériennes dans des contextes différents, dépendants de l'expression de cytokines.The aim of this thesis vas to investigate the implication of the matrix metalloproteinases MMP-2 and MMP-9 in airway remodeling, a constant feature of chronic inflammatory airway diseases. A low basal MMP-2 et MMP-9 expression vas detected, consistent with a role in homeostatic remodeling. In vivo, MMP-9 expression vas increased in nasal polyposis, especially in epithelial celis. In vitro, TGF enhanced airway repair via MMP-2. These findings suggest that MMP-2 and MMP-9 could play different role during airway repair and remodeling, possibly related to various cytokines expression.PARIS12-CRETEIL BU Multidisc. (940282102) / SudocSudocFranceF

[Diagnosis of brain metastases: an update in 2012].

International audienceDiagnosis of brain metastases should aim to identify anatomoclinical entities for which a specific treatment is more accurate. Growing numbers of targeted therapies have shown to be effective against specific cancers. Several studies have reported that targeted therapies are capable of reducing brain metastases in melanoma or non small cell lung cancer (NSCLC), sometimes with a high dramatic response. These results have clearly impacted routine neuropathological practice, leading to multidisciplinary strategy management of brain metastases tissues. In accordance with the recommendations of French National Cancer Institute (INCa), the pathologist develops appropriate strategies for molecular and immunohistochemical analysis, in order to provide results as soon as possible

Predictive biomarkers in patients with resected non-small cell lung cancer treated with perioperative chemotherapy

International audienceThe aim of this article is to summarise the published data on prognostic and predictive biomarkers for early-stage non-small cell lung cancer (NSCLC), and discuss how to integrate them into clinical trials. Large phase III trials have been published in resected NSCLC with biomarkers identifying subsets of patients benefitting from perioperative chemotherapy. Initial findings of predictive implications for the DNA repair protein, ERCC1, were not confirmed in a larger series of patients due to the versatility of the commercially available monoclonal ERCC1 antibody. Prediction of survival by RRM1 tumour expression was not confirmed in a prospective phase III trial in 275 patients with stage IV disease, precluding its use in early-stage NSCLC. BRCA1 mRNA tumour content also failed to predict platinum resistance in 287 stage IV NSCLC patients included in a phase II trial, and the results of a similar trial in early-stage patients are still pending. Of the several cDNA gene expression studies in early-stage NSCLC with non-overlapping prognostic signatures, few have been replicated in independent cohorts for prognostic value, and none received external validation for predictive value. Therefore, use of biomarkers predicting chemotherapy efficacy still needs additional validation before becoming routine practice in oncogene-driven pan-negative NSCLC patients

Hypoxia-inducible factor-2α (HIF-2α), but not HIF-1α, is essential for hypoxic induction of class III β-tubulin expression in human glioblastoma cells

International audienceGlioblastoma multiforme (GBM) is the deadliest form of primary brain cancer. Several reports have indicated aberrant levels of βIII-tubulin (βIII-t) in human GBM. βIII-t overexpression was linked to increasing malignancy in glial tumors and described to determine the onset of resistance to chemotherapy. Furthermore, a linkage was suggested between the induction of βIII-t expression and hypoxia, a hallmark of GBM. We investigated the role of hypoxia-inducible factor (HIF)-1α and HIF-2α in the regulation of the βIII-t gene (TUBB3) in GBM cells cultured in either normoxia or hypoxia. We report for the first time that HIF-2α, but not HIF-1α, is involved in hypoxia-induced βIII-t expression in GBM cells. By gene-reporter experiments and site-directed mutagenesis, we found that two overlapping hypoxia response elements located in the 3′ UTR of the gene were involved in the activation of TUBB3. This occurred through an enhanced binding of HIF-2α to the 3′ region, as revealed by an electrophoretic mobility shift assay. Conversely, the promoter of TUBB3 was shown to be inactive. In addition, we observed that HIF-1α exhibits a repressive effect on βIII-t expression in cells cultured in normoxia. These results show that both HIF-α isoforms have opposing effects on βIII-t expression in GBM cells. Finally, we observed that hypoxia-induced βIII-t expression is well correlated with the kinetics of HIF-2α protein stabilization. The evidence for a direct linkage between HIF-2α and increased expression of βIII-t by hypoxia suggests that an anti-HIF-2α strategy (i.e. by downregulating βIII-t) could be of potential interest for improving the treatment of GBM

[Malignant pleural mesothelioma: 2013 state of the art].

International audienceMalignant pleural mesothelioma (MPM) is a bad-prognosis cancer raising difficult issues according to diagnosis. Reliable histological diagnosis indeed requires large-sized pathological samples obtained by thoracoscopy, and need diagnosis certification by the MESOPATH national expert pathological committee. MPM epidemiology shows a rising incidence among females, whereas an incidence plateau has been reached for males in France. The incidence peak is still predicted for 2030 decade in UK, Australia and North America, because of the asbestosis massive use in their industry until the end of 1980 decade. Pleural carcinogenesis is better understood with the recent discovery of BAP1 susceptibility gene although no oncogenic driver has been ever uncovered for targeted therapies, although several more or less targeted biological therapies are currently tested in early phase or more advanced-phase trials. Surgery is more and more questioned, since radical surgery is currently abandoned, whereas debulking or cyto-reduction surgery has been proposed within a multimodality approach also including adjuvant chemotherapy and radiotherapy but still need prospective trials. Pemetrexed and cisplatin-based chemotherapy remains the reference treatment, which has proved in mesothelioma some efficacy on overall survival in randomized trials, with a 13-15 months median-overall survival. Final results of the large phase 3 clinical trial "MAPS" sponsored by French collaborative Intergroup (IFCT) evaluating the effect of bevacizumab addition to pemetrexed-cisplatin doublet will be released in early 2015, since 445 patients have been included by November 2013

The Use of Pro-Angiogenic and/or Pro-Hypoxic miRNAs as Tools to Monitor Patients with Diffuse Gliomas

CERVOXYInternational audienceIDH (isocitrate dehydrogenase) mutation, hypoxia, and neo-angiogenesis, three hallmarks of diffuse gliomas, modulate the expression of small non-coding RNAs (miRNA). In this paper, we tested whether pro-angiogenic and/or pro-hypoxic miRNAs could be used to monitor patients with glioma. The miRNAs were extracted from tumoral surgical specimens embedded in the paraffin of 97 patients with diffuse gliomas and, for 7 patients, from a blood sample too. The expression of 10 pro-angiogenic and/or pro-hypoxic miRNAs was assayed by qRT-PCR and normalized to the miRNA expression of non-tumoral brain tissues. We confirmed in vitro that IDH in hypoxia (1% O2, 24 h) alters pro-angiogenic and/or pro-hypoxic miRNA expression in HBT-14 (U-87 MG) cells. Then, we reported that the expression of these miRNAs is (i) strongly affected in patients with glioma compared to that in a non-tumoral brain; (ii) correlated with the histology/grade of glioma according to the 2016 WHO classification; and (iii) predicts the overall and/or progression-free survival of patients with glioma in univariate but not in a multivariate analysis after adjusting for sex, age at diagnosis, and WHO classification. Finally, the expression of miRNAs was found to be the same between the plasma and glial tumor of the same patient. This study highlights a panel of seven pro-angiogenic and/or pro-hypoxic miRNAs as a potential tool for monitoring patients with glioma

Effects of betaIII-tubulin knockdown on the growth of glioblastoma cells and on the efficacy of chemotherapies.

CERVOXYNational audienc

Promoter hypermethylation of genes encoding for RASSF/Hippo pathway members reveals specific alteration pattern in diffuse gliomas

CERVOXY COLLInternational audienc

TGF-β1 downregulates CFTR expression and function in nasal polyps of non-CF patients

International audienceNasal polyposis is a chronic inflammatory disease of the upper airways. It has been suggested that ion transports and CFTR expression could be modified in epithelial cells from nasal polyps of non-cystic fibrosis patients. We compared human nasal epithelial cells from nasal polyps (NP) with control nasal mucosa (CM). The level of CFTR mRNA was studied by Northern blot analysis and protein expression was studied by immunoprecipitation both ex vivo and in vitro in primary cultures of human nasal epithelial cells at the air-liquid interface. Ion transports were evaluated by short-circuit measurements in vitro. CFTR gene and protein expressions were significantly decreased in NP native tissues and in culture on day 4, when a global defect of ion transports was observed in NP cultures, but not in CM. We evaluated the effect of transforming growth factor (TGF)-β1 on CFTR expression and function in NP cultures on day 14 and showed, for the first time, that TGF-β1 was able to significantly downregulate the level of CFTR mRNA and cAMP-dependent current in NP cultures. Finally, we showed that the effects of TGF-β1 on ion transports could be reversed after 48-h removal of TGF-β1 in NP cultures. In conclusion, our data strongly suggest that chronic inflammation in nasal polyposis downregulates CFTR gene and protein expression

Transforming growth factor-beta1 increases airway wound repair via MMP-2 upregulation: a new pathway for epithelial wound repair

International audienceIn vivo, transforming growth factor (TGF)-beta1 and matrix metalloproteinases (MMPs) present at the site of airway injury are thought to contribute to epithelial wound repair. As TGF-beta1 can modulate MMP expression and MMPs play an important role in wound repair, we hypothesized that TGF-beta1 may enhance airway epithelial repair via MMPs secreted by epithelial cells. We evaluated the in vitro influence of TGF-beta1 on wound repair in human airway epithelial cells cultured under conditions allowing differentiation. The results showed that TGF-beta1 accelerated in vitro airway wound repair, whereas MMP inhibitors prevented this acceleration. In parallel, we examined the effect of TGF-beta1 on the expression of MMP-2 and MMP-9. TGF-beta1 induced a dramatic increase of MMP-2 expression with an increased steady-state level of MMP-2 mRNA, contrasting with a slight increase in MMP-9 expression. To confirm the role of MMP-2, we subsequently evaluated the effect of MMP-2 on in vitro airway wound repair and demonstrated that the addition of MMP-2 reproduced the acceleration of wound repair induced by TGF-beta1. These results strongly suggest that TGF-beta1 increases in vitro airway wound repair via MMP-2 upregulation. It also raises the issue of a different in vivo biological role of MMP-2 and MMP-9 depending on the cytokine microenvironment