title: uPAR and cathepsin B downregulation induces apoptosis by targeting calcineurin A to BAD via Bcl-2 in glioma.
abstract: Cathepsin B and urokinase plasminogen activator receptor (uPAR) are postulated to play key roles in glioma invasion. Calcineurin is one of the key regulators of mitochondrial-dependent apoptosis, but its mechanism is poorly understood. Hence, we studied subcellular localization of calcineurin after transcriptional downregulation of uPAR and cathepsin B in glioma. In the present study, efficient downregulation of uPAR and cathepsin B increased the translocation of calcineurin A from the mitochondria to the cytosol, decreased pBAD (S136) expression and its interaction with 14-3-3ζ and increased the interaction of BAD with Bcl-xl. Co-depletion of uPAR and cathepsin B induced mitochondrial translocation of BAD, activation of caspase 3 as well as PARP and cytochrome c and SMAC release. These effects were inhibited by FK506 (10 μM), a specific inhibitor of calcineurin. Calcineurin A was co-localized and also co-immunoprecipitated with Bcl-2. This interaction decreased with co-depletion of uPAR and cathepsin B and also with Bcl-2 inhibitor, HA 14-1 (20 μg/ml). Altered localization and interaction of calcineurin A with Bcl-2 was also observed in vivo when uPAR and cathepsin B were downregulated. In conclusion, downregulation of uPAR and cathepsin B induced apoptosis by targeting calcineurin A to BAD via Bcl-2 in glioma.
authors.affiliation: Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, One Illini Drive, Peoria, IL 61605, USA.
authors.forename: Rama Rao
authors.initials: RR
authors.lastname: Malla
authors.forename: Sreelatha
authors.initials: S
authors.lastname: Gopinath
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Gondi
authors.forename: Kiranmai
authors.initials: K
authors.lastname: Alapati
authors.forename: Dzung H
authors.initials: DH
authors.lastname: Dinh
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Tsung
authors.forename: Jasti S
authors.initials: JS
authors.lastname: Rao
mesh_terms: D017209:Apoptosis; D015153:Blotting, Western; D019703:Calcineurin / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism; D002401:Cathepsin B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D045744:Cell Line, Tumor; D045304:Cytochromes c / Q000378:metabolism; D015536:Down-Regulation; D005455:Fluorescent Antibody Technique; D005910:Glioma / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D007124:Immunoenzyme Techniques; D047468:Immunoprecipitation; D053078:Membrane Potential, Mitochondrial; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D055293:Receptors, Urokinase Plasminogen Activator / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015398:Signal Transduction; D013347:Subcellular Fractions; D051025:bcl-Associated Death Protein / Q000378:metabolism*
chemical_list: C494819:BAD protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D055293:Receptors, Urokinase Plasminogen Activator; D051025:bcl-Associated Death Protein; D045304:Cytochromes c; D019703:Calcineurin; D053148:Caspase 3; D002401:Cathepsin B