Clinical significance of T-bet, GATA-3, and Bcl-6 transcription factor expression in bladder carcinoma

International audienceBackground: The aim of this study was to investigate the clinical significance of three immune cell-related transcription factors, T-bet, GATA-3 and Bcl-6 in bladder cancer in Tunisian patients.Methods: Expression of T-bet, GATA-3 and Bcl-6 genes was assessed using RT-qPCR in 65 bladder cancers from patients: 32 being diagnosed as low-and medium-grade, 31 as high-grade, 25 as muscle invasive stage and 39 as non-muscle invasive stage. Gene expression was statistically correlated according to the grade, the stage, tobacco consumption, the BCG response and disease severity.Results: T-bet levels in patients with high-grade bladder cancer were significantly elevated compared to patients with low-or medium-grade bladder cancer (p = 0.005). In invasive carcinoma (T2-T4), the T-bet levels were significantly higher than in superficial non-invasive bladder tumors (Tis, Ta, and T1) (p = 0.02). However, T-bet is predictive of the response to BCG. Its expression is high in good responders to BCG (p = 0.02). In contrast, the expression of GATA-3 and Bcl-6 in non-invasive carcinoma (p = 0.008 and p = 0.0003) and in patients with low-and medium-grade cancers (p = 0.001 and p < 0.0001) is significantly higher than in invasive bladder tumors and in patients with high-grade bladder carcinoma, respectively. In addition, heavy smokers, whose tumors express low levels of GATA-3 and Bcl-6, are poor responders to BCG (p = 0.01 and p = 0.03). Finally, better patient survival correlated with GATA-3 (p = 0.04) and Bcl-6 (p = 0.04) but not T-bet expression.Conclusions: Our results suggest that T-bet expression in bladder tumors could be a positive prognostic indicator of BCG therapy, even if high levels are found in high-grade and stage of the disease. However, GATA-3 and Bcl-6 expression could be considered as predictive factors for good patient survival

Extreme Idiopathic gigantomastia

Gigantomastia is a rare mastopathy of unknown cause. Due to mechanical and psychological complications related to excessive breast weights and volume, effective surgical treatment is required. Most cases of gigantomastia in the literature are associated with pregnancy or puberty and very rare cases of spontaneous gigantomastia have been reported We report a 38 years old woman with an idiopathic gigantomastia treated successfully with Thorek technique

Temporal Dynamics and Impact of Climate Factors on the Incidence of Zoonotic Cutaneous Leishmaniasis in Central Tunisia

Old world cutaneous leishmaniasis is a vector-borne disease occurring in rural areas of developing countries. The main reservoirs are the rodents Psammomys obesus and Meriones shawi. Zoonotic Leishmania transmission cycle is maintained in the burrows of rodents where the sand fly Phlebotomus papatasi finds the ideal environment and source of blood meals. In the present study we showed seasonality of the incidence of disease during the same cycle with an inter-epidemic period ranging from 4 to 7 years. We evaluated the impact of climate variables (rainfall, humidity and temperature) on the incidence of zoonotic cutaneous leishmaniais in central Tunisia. We confirmed that the risk of disease is mainly influenced by the humidity related to the months of July to September during the same season and mean rainfall lagged by 12 to 14 months

Régulation de la mort cellulaire induite par des agents cytotoxiques (rôles de la PKC zeta et de la caspase-10)

DIJON-BU Médecine Pharmacie (212312103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Mécanismes de sensibilisation des cellules cancéreuses coliques humaines au glycéryltrinitrate associé à un inhibiteur de kinases

Le monoxyde d azote ou NO (Nitric Oxide) produit par l activation de la NO-synthase inductible ou par un donneur chimique peut sensibiliser in vitro des cellules cancéreuses à la mort induite par des cytokines ou par des agents cytotoxiques peu efficaces par eux-mêmes. Ces résultats sont confirmés chez l homme où un donneur de NO, le glycéryltrinitrate (GTN) a montré des effets bénéfiques dans le traitement du cancer dans plusieurs essais cliniques. Dans notre laboratoire, nous avons montré que, in vitro, de fortes concentrations de GTN induisent l apoptose des cellules cancéreuses coliques humaines, alors qu à des concentrations pharmacologiques, le GTN n est pas toxique. Il le devient lorsqu il est associé à un inhibiteur de kinases, H89. Le projet que nous avons réalisé se proposait de caractériser les voies de signalisation qui sont à l origine de cette sensibilisation. Nous avons montré que cette sensibilisation implique plusieurs acteurs de la signalisation cellulaire : 1) Elle dépend de la production à la fois du NO et d espèces radicalaires oxygénées (ROS). 2) Elle fait intervenir les caspases et est corrélée à une dépolarisation de la mitochondrie. 3) Elle implique les récepteurs purinergiques qui seraient capables de reconnaître H89 (jamais décrit). Les perspectives offertes par cette étude seraient de sélectionner certaines protéines de la signalisation cellulaire qui pourraient à terme constituer de nouvelles cibles thérapeutiques à développer dans le traitement du cancer du côlon.In vitro, nitric oxide (NO), produced by the activation of inducible NO synthase or by NO donor, sensitizes cancer cells to death induced by cytokines or cytotoxic agents ineffective by themselves. These results are confirmed in humans since a NO donor, nitroglycerin (NTG), has shown beneficial effects in cancer treatment in several clinical trials. In our laboratory, we showed in vitro that high concentrations of GTN induced apoptosis in human colon cancer cells, whereas pharmacological concentrations did not. Low concentrations of GTN are toxic when combined with a kinase inhibitor, H89. This project proposed to characterize the signaling pathways that are the source of this sensitization. We have shown that this mechanism involves several actors of cell signaling: 1) It depends on the production of both NO and free reactive oxygen species (ROS). 2) It involves caspases and correlates with depolarization of the mitochondria. 3) It involves the purinergic receptors that are capable of recognizing H89 (never described). The prospects offered by this study would select some proteins of the cell signaling that could eventually form new therapeutic targets to develop in the treatment of colon cancer.DIJON-BU Sciences Economie (212312102) / SudocSudocFranceF

Régulation de la mort cellulaire induite par des agents cytotoxiques (rôles de la PKC zeta et de la caspase-10)

DIJON-BU Médecine Pharmacie (212312103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Apoptose et voie WNT/beta -caténine (induction et régulation par le monoxyde d azote dans des cellules cancéreuses coliques humaines)

Les cancers sont le plus souvent la conséquence d une perturbation de l équilibre entre la vie et la mort cellulaire. Ainsi, tout agent cytotoxique capable d intervenir sur ces processus est potentiellement utilisable dans le traitement des cancers. Nous avons démontré, que le GTN (GlycerylTriNitrate), un donneur endogène de monoxyde d azote (NO), induit l apoptose des cellules cancéreuses coliques humaines de manière dépendante des caspases-1 et -10 et les sensibilise à l apoptose induite par le ligand de Fas. Nous avons également analysé les effets du GTN sur la voie de signalisation Wnt/beta caténine impliquée dans la survenue des cancers colorectaux. J ai démontré que le GTN diminue très fortement l activité de cette voie en activant une enzyme sensible aux inhibiteurs de sérine protéases, TPCK et AEBSF. Nous avons ainsi mis en évidence un mécanisme original de régulation de la voie Wnt/ beta caténine qui s ajoute à ceux impliquant le protéasome, les caspases ou encore les calpaïnes.Deregulation of signaling pathways involved in survival or cell death is the leading cause of cancer. Therefore, any cytotoxic agent able to modulate these pathways is potentially efficient in cancer treatment. We demonstrate that, glyceryltrinitrate (GTN), an endogenous nitric oxide (NO) donor, induces caspase-1 and -10-dependant human colon cancer cells apoptosis. Moreover, GTN sensitizes these cells to Fas ligand induced apoptosis. We also analyze GTN effects on the oncogenic signaling Wnt/ beta catenin pathway which is highly active in colorectal cancer. I demonstrate that GTN induces a strong decrease of this activity mediated by an enzyme sensitive to two serine protease inhibitors, TPCK and AEBSF. Therefore, we describe an original regulatory mechanism of the Wnt/ beta catenin pathway additionally to proteasome, calpain or caspase degradation pathways.DIJON-BU Sciences Economie (212312102) / SudocSudocFranceF

Apoptose de cellules cancéreuses coliques humaines traitées par un générateur de monoxyde d'azote

Il a été observé dans notre laboratoire que la production de monoxyde d azote (NO) par des cellules tumorales chez le rat est corrélée à l apoptose de ces mêmes cellules. Afin de comprendre les mécanismes moléculaires de l apoptose induite par le NO, nous avons étudié in vitro les effets d un générateurs de NO, le glyceryltrinitrate (GTN) sur des lignées de cellules cancéreuses coliques humaines. Nos résultats montrent que le GTN induit une mort par apoptose des cellules cancéreuses coliques fonction de la dose de GTN et du temps de traitement. L apoptose induite par le GNT implique les caspases et plus particulièrement les caspases-1 et -10, ainsi que la mitochondrie. Dans notre modèle, l activation de la caspase-3 est limitée et plus tardive. Les récepteurs de mort ne sont pas impliqués dans la mort cellulaire induite par le GTN, mais le GTN sensibilise les cellules cancéreuses coliques à l apoptose induite par un agoniste du récepteur Fas. Cet effet du GTN est en corrélation avec une augmentation de l expression du récepteur Fas et une diminution de l expression de plusieurs protéines de la famille Inhibitor of Apoptosis Protein. Ces résultats suggèrent que les donneurs de NO pourraient être une alternative dans le traitement du cancer du côlon, seuls ou en association à une chimiothérapie classique.It was observed in our laboratory that the production of nitric oxide (NO) by tumour cells in rats is correlated with their apoptosis. The present study was designed to explore the influence of an endogenous NO donor, glyceryltrinitrate (GTN) on the cell death pathways in colon cancer cells. GTN induces a dose- and a time-dependent cell apoptosis in colon cancer cells. This cell death pathway involves the mitochondria and caspases, mainly caspase-1 and -10. In contrast, caspase-3 activation is a late and limited event. Death receptors are not involved in GTN-mediated cell death, while GTN induces a Fas ligand (FasL)-independent plasma membrane Fas aggregation and sensitises tumour cells to FasL-induced apoptosis. This permissive effect correlates with an increased expression of Fas receptor and a decreased expression of several endogenous inhibitors of apoptosis (IAPs). Our results suggest that NO-donating drugs could have a beneficial effects in the treatment of colon cancer when used alone or in combination with chemotherapy.DIJON-BU Médecine Pharmacie (212312103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Exploration of Fas S-Nitrosylation by the Biotin Switch Assay

International audienceS-nitrosylation is the covalent attachment of nitric oxide radical to the thiol side chain of cysteine. The death receptor Fas/CD95 can be S-nitrosylated in cancer cell lines by NO donors or iNOS activation. This posttranslational modification (PTM) induces Fas aggregation into lipid rafts and enhances FasL-mediated signaling and apoptosis. In this report, we describe the detection of Fas S-nitrosylation by the most commonly used method, the biotin switch assay (BSA) technique, that allows the detection of this very labile covalent modification in cells or tissues. Briefly, this technique relies on the ability of ascorbate to reduce the covalent bond between the NO radical and the protein, allowing the exchange of the NO radical with a thiol reactive biotin-HPDP. The biotinylated proteins are then easily purified by using NeutrAvidin resin, separated by SDS-PAGE resolution and analyzed by Western blotting

H89 Treatment Reduces Intestinal Inflammation and Candida albicans Overgrowth in Mice

International audienceDeregulation of the dynamic crosstalk between the gut microbiota, intestinal epithelial cells, and immune cells is critically involved in the development of inflammatory bowel disease and the overgrowth of opportunistic pathogens, including the human opportunistic fungus Candida albicans. In the present study, we assessed the effect of N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide (H89), a protein kinase A inhibitor, on the migration of macrophages to C. albicans through dextran sulphate sodium (DSS)-challenged Caco-2 cells. We also investigated the impact of H89 on intestinal inflammation and C. albicans clearance from the gut, and determined the diversity of the gut microbiota in a murine model of DSS-induced colitis. H89 reduced the migration of macrophages to C. albicans through DSS-challenged Caco-2 cells. In addition, H89 decreased C. albicans viability and diminished the expression of pro-inflammatory cytokines and innate immune receptors in macrophages and colonic epithelial Caco-2 cells. In mice with DSS-induced colitis, H89 attenuated the clinical and histological scores of inflammation and promoted the elimination of C. albicans from the gut. H89 administration to mice decreased the overgrowth of Escherichia coli and Enterococcus faecalis populations while Lactobacillus johnsonii populations increased significantly. Overall, H89 reduced intestinal inflammation and promoted the elimination of C. albicans from the gut