Abstract
BACKGROUND. Accumulating evidence suggest a critical role of activation of androgen receptor (AR) by nonandrogen in the development of androgen independent prostate cancer. Previous study identified that interleukin-4 (IL-4) enhances AR activation in the absence of androgen or in the very low levels of androgen in prostate cancer cells. In this study, the mechanism of IL-4-induced AR activation was investigated. METHODS & RESULTS. The induction of AR activation by IL-4 can be suppressed by expression of the IκBα, an inhibitor of NF-κB. The enhanced expression of AR-mediated prostate-specific antigen (PSA) by IL-4 was blocked by the expression of IκBα. IL-4 increases NF-κB transcriptional activity in prostate cancer cells which can be blocked by the addition of IL-4 antibody. IL-4 can also rapidly activate NF-κB. Furthermore, the IL-4-induced NF-κB activation and nuclear translocation can be blocked by LY294002, a PI3K/Akt specific inhibitor, suggesting that IL-4-induced NF-κB activation is mediated by activation of PI3K/Akt pathway. CONCULSION. In combination with previous study that IL-4 activates PI3K/Akt pathway, activation of PI3K/Akt > NF-κB pathways may be responsible for IL-4-induced AR activation in prostate cancer cells. Taken together, these studies suggest that IL-4 > PI3K/Akt > NF-κB signaling pathways, which activate AR signaling, may play an important role during the progression of androgen independent prostate cancer cells.
Original language | English (US) |
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Pages (from-to) | 160-167 |
Number of pages | 8 |
Journal | Prostate |
Volume | 64 |
Issue number | 2 |
DOIs | |
State | Published - Jul 1 2005 |
Externally published | Yes |
Keywords
- Androgen receptor
- IL-4
- NF-κB
- Prostate cancer
- PSA
ASJC Scopus subject areas
- Urology