NVP-BEZ235, a dual PI3K/mTOR inhibitor synergistically potentiates the antitumor effects of cisplatin in bladder cancer cells

Du Geon Moon, Sang E. Lee, Mi-Mi Oh, Sang C. Lee, Seong J. Jeong, Sung K. Hong, Cheol Y. Yoon, Seok S. Byun, Hong Seok Park, Jun Cheon

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35 Citations (Scopus)

Abstract

The PI3K/Akt/mTOR pathway is a prototypic survival pathway and constitutively activated in many malignant conditions. Moreover, activation of the PI3K/Akt/mTOR pathway confers resistance to various cancer therapies and is often associated with a poor prognosis. In this study, we explored the antitumor effect of NVP-BEZ235, a dual PI3K/mTOR inhibitor in cisplatin-resistant human bladder cancer cells and its synergistic interaction with cisplatin. A human bladder cancer cell line with cisplatin resistance was exposed to escalating doses of NVP-BEZ235 alone or in combination with cisplatin and antitumor effects was determined by the CCK-8 assay. Based on a dose-response study, synergistic interaction between NVP-BEZ235 and cisplatin was evaluated by combination index (CI), three-dimensional model and clonogenic assay. The combination of NVP-BEZ235 and cisplatin caused significant synergistic antitumor effect in cisplatin-resistant bladder cancer cells over a wide dose range and reduced the IC50 of NVP-BEZ235 and cisplatin by 5.6- and 3.6-fold, respectively. Three-dimensional synergy analysis resulted in a synergy volume of 388.25 μM/ml2% indicating a strong synergistic effect of combination therapy. The combination therapy caused cell cycle arrest and caspase-dependent apoptosis. Although NVP-BEZ235 suppressed PI3K/mTOR signaling without any paradoxical induction of Akt activity, it caused MEK/ERK pathway activation. The present study demonstrated that the PI3K/mTOR dual inhibitor NVP-BEZ235 can synergistically potentiate the antitumor effects of cisplatin in cisplatin-resistant bladder cancer cells though the suppression of cell cycle progression and the survival pathway as well as induction of caspase-dependent apoptosis.

Original languageEnglish
Pages (from-to)1027-1035
Number of pages9
JournalInternational Journal of Oncology
Volume45
Issue number3
DOIs
Publication statusPublished - 2014 Jan 1

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Keywords

  • Carcinoma
  • Cisplatin
  • NVP-BEZ235
  • Resistance
  • Urinary bladder

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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