PT  - JOURNAL ARTICLE
AU  - ARPAD SZANTO
AU  - ZITA BOGNAR
AU  - ANDRAS SZIGETI
AU  - ALIZ SZABO
AU  - LASZLO FARKAS
AU  - FERENC GALLYAS, Jr.
TI  - Critical Role of Bad Phosphorylation by Akt in Cytostatic Resistance of Human Bladder Cancer Cells
DP  - 2009 Jan 01
TA  - Anticancer Research
PG  - 159--164
VI  - 29
IP  - 1
4099  - http://ar.iiarjournals.org/content/29/1/159.short
4100  - http://ar.iiarjournals.org/content/29/1/159.full
SO  - Anticancer Res2009 Jan 01; 29
AB  - Background: Taxol is the most commonly used agent for salvage chemotherapy in transitional cell carcinoma of the urothelium. We examined mechanisms responsible for taxol resistance by using T24 human bladder carcinoma cells. Materials and Methods: We used an inhibitor and an activator of the phosphatidylinositol-3 kinase-Akt pathway in cell survival and caspase-3 assays, an HPLC method for determining released cytochrome c and immunoblotting for detecting protein phosphorylation. Results: Activation of Akt increased paclitaxel resistance by increasing Bad phosphorylation, leading to decreased release of mitochondrial cytochrome c and caspase-3-mediated apoptosis. On the other hand, inhibition of Akt prevented paclitaxel resistance by enhancing the effects of paclitaxel on Bad phosphorylation, mitochondrial cytochrome c release and caspase-3-mediated apoptosis, besides diminishing or abolishing the opposing effects of Akt activation. Conclusion: Akt-mediated Bad phosphorylation plays an important role in preservation of mitochondrial membrane systems leading to paclitaxel resistance in T24 cells. Copyright© 2009 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved