uPAR and cathepsin B downregulation induces apoptosis by targeting calcineurin A to BAD via Bcl-2 in glioma
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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.
KeywordsCalcineurin BAD Bcl2 Glioma
This research was supported by National Institutes of Health, CA116708 (to JSR). Contents of this manuscript are solely the responsibility of the authors and do not necessarily represent the official views of NIH.
- 13.Toth R, Szegezdi E, Molnar G, Lord JM, Fesus L, Szondy Z (1999) Regulation of cell surface expression of Fas (CD95) ligand and susceptibility to Fas (CD95)-mediated apoptosis in activation-induced T cell death involves calcineurin and protein kinase C, respectively. Eur J Immunol 29:383–393PubMedCrossRefGoogle Scholar
- 17.Gondi CS, Kandhukuri N, Kondraganti S, Gujrati M, Olivero WC, Dinh DH, Rao JS (2006) RNA interference-mediated simultaneous down-regulation of urokinase-type plasminogen activator receptor and cathepsin B induces caspase-8-mediated apoptosis in SNB19 human glioma cells. Mol Cancer Ther 5:3197–3208PubMedCrossRefGoogle Scholar
- 30.Danial NN (2008) BAD: undertaker by night, candyman by day. Oncogene 27 Suppl 1:S53–S70Google Scholar