Castration resistance of prostate cancer cells caused by castration-induced oxidative stress through Twist1 and androgen receptor overexpression.

Autor: Shiota, M., Yokomizo, A., Tada, Y., Inokuchi, J., Kashiwagi, E., Masubuchi, D., Eto, M., Uchiumi, T., Naito, S.
Předmět:
Zdroj: Oncogene; 1/14/2010, Vol. 29 Issue 2, p237-250, 14p, 1 Diagram, 6 Graphs
Abstrakt: There are few successful therapies for castration-resistant prostate cancer (CRPC). Recently, CRPC has been thought to result from augmented androgen/androgen receptor (AR) signaling pathway, for most of which AR overexpression has been observed. In this study, Twist1, a member of basic helix-loop-helix transcription factors as well as AR was upregulated in response to hydrogen peroxide, and the response to which was abolished by an addition of N-acetyl-L-cysteine and Twist1 knockdown. In addition, castration-resistant LNCaP derivatives and hydrogen peroxide-resistant LNCaP derivatives exhibited a similar phenotype to each other. Then, both castration and AR knockdown increased intracellular reactive oxygen species level. Moreover, Twist1 was shown to regulate AR expression through binding to E-boxes in AR promoter region. Silencing of Twist1 suppressed cell growth of AR-expressing LNCaP cells as well as castration-resistant LNCaP derivatives by inducing cell-cycle arrest at G1 phase and cellular apoptosis. These findings indicated that castration-induced oxidative stress may promote AR overexpression through Twist1 overexpression, which could result in a gain of castration resistance. Modulation of castration-induced oxidative stress or Twist1/AR signaling might be a useful strategy for developing a novel therapeutics in prostate cancer, even in CRPC, which remains dependent on AR signaling by overexpressing AR. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index