title: Insights on distinct pathways of thiazolidinediones (PPARgamma ligand)-promoted apoptosis in TRAIL-sensitive or -resistant malignant urothelial cells.
abstract: Thiazolidinediones, including rosiglitazone and troglitazone, are insulin-sensitizing drugs and high-affinity ligands for the peroxisome proliferator-activated receptor gamma (PPARgamma). Apart from their antidiabetic activity, these molecules possess antitumor properties. We investigated their potential apoptotic effects on RT4 (derived from a well-differentiated Grade I papillary tumor) and T24 (derived from an undifferentiated Grade III carcinoma) bladder cancer cells. Rosiglitazone induced G2/M or G0/G1 phase cell cycle arrest in RT4 and T24 cells, respectively. Only troglitazone triggered apoptosis via extrinsic and intrinsic pathways in both cell lines. Interestingly, rosiglitazone amplified TRAIL-induced apoptosis in TRAIL-sensitive RT4 cells or let TRAIL-resistant T24 cells to respond to TRAIL. Thiazolidinediones acted through PPARgamma activation-independent mechanisms. The underlying mechanisms involved for the first time in cancer cells the upregulation of soluble and/or membrane-bound TRAIL. This was associated with increased cell surface death receptor 5 expression and c-FLIP and survivin downregulation, mediated in part through proteasome-dependent degradation in troglitazone-promoted cell death. Therefore, the combination of rosiglitazone and TRAIL could be clinically relevant as chemopreventive or therapeutic agents for the treatment of TRAIL-resistant high-grade urothelial cancers.
authors.affiliation: Laboratoire de Biologie Cellulaire et Moléculaire, EA3181-IFR N133, Université de Franche-Comté, UFR des Sciences Médicales et Pharmaceutiques, Besançon, France.
authors.forename: Marie Laure
authors.initials: ML
authors.lastname: Plissonnier
authors.forename: Sylvie
authors.initials: S
authors.lastname: Fauconnet
authors.forename: Hugues
authors.initials: H
authors.lastname: Bittard
authors.forename: Isabelle
authors.initials: I
authors.lastname: Lascombe
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm; D005434:Flow Cytometry; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D047495:PPAR gamma / Q000378:metabolism*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism; D000077022:Survivin; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism*; D045162:Thiazolidinediones / Q000494:pharmacology*; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*
chemical_list: C107489:BIRC5 protein, human; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; C506386:CFLAR protein, human; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D047495:PPAR gamma; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D000077022:Survivin; D053221:TNF-Related Apoptosis-Inducing Ligand; D045162:Thiazolidinediones