Open AccessInterleukin-8 signaling promotes androgen-independent proliferation of prostate cancer cells via induction of androgen receptor expression and activation
Author(s) -
Angela Seaton,
Paula Scullin,
Pamela Maxwell,
Catherine Wilson,
Johanna Pettigrew,
Ryan Gallagher,
Joe M. O’Sullivan,
Patrick G. Johnston,
David J. Waugh
Publication year - 2008
Publication title -
carcinogenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.688
H-Index - 204
eISSN - 1460-2180
pISSN - 0143-3334
DOI - 10.1093/carcin/bgn109
Subject(s) - lncap , androgen receptor , androgen , prostate cancer , endocrinology , chemistry , cancer research , signal transduction , medicine , biology , microbiology and biotechnology , cancer , hormone
The aim of our study was to assess the importance of the CXC chemokine and interleukin (IL)-8 in promoting the transition of prostate cancer (CaP) to the androgen-independent state. Stimulation of the androgen-dependent cell lines, LNCaP and 22Rv1, with exogenous recombinant human interleukin-8 (rh-IL-8) increased androgen receptor (AR) gene expression at the messenger RNA (mRNA) and protein level, assessed by quantitative polymerase chain reaction and immunoblotting, respectively. Using an androgen response element-luciferase construct, we demonstrated that rh-IL-8 treatment also resulted in increased AR transcriptional activity in both these cell lines, and a subsequent upregulation of prostate-specific antigen and cyclin-dependent kinase 2 mRNA transcript levels in LNCaP cells. Blockade of CXC chemokine receptor-2 signaling using a small molecule antagonist (AZ10397767) attenuated the IL-8-induced increases in AR expression and transcriptional activity. Furthermore, in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, coadministration of AZ10397767 reduced the viability of LNCaP and 22Rv1 cells exposed to bicalutamide. Our data show that IL-8 signaling increases AR expression and promotes ligand-independent activation of this receptor in two androgen-dependent cell lines, describing two mechanisms by which this chemokine may assist in promoting the transition of CaP to the androgen-independent state. In addition, our data show that IL-8-promoted regulation of the AR attenuates the effectiveness of the AR antagonist bicalutamide in reducing CaP cell viability.