ICI 182,780-regulated gene expression in DU145 prostate cancer cells is mediated by estrogen receptor-beta/NFkappaB crosstalk
Graduate School of Biomedical Sciences; Department of Surgery, Division of Urology
Life Sciences | Medicine and Health Sciences
Estrogen receptor (ER)-beta is the predominant ER subtype in prostate cancer (PCa). We previously demonstrated that ICI 182,780 (ICI), but not estrogens, exerted dose-dependent growth inhibition on DU145 PCa cells by an ER-beta-mediated pathway. Transcriptional profiling detected a greater than three-fold upregulation of seven genes after a 12-hour exposure to 1 microM ICI. Semiquantitative reverse transcriptase polymerase chain reaction confirmed the upregulation of four genes by ICI: interleukin-12alpha chain, interleukin-8, embryonic growth/differentiation factor, and RYK tyrosine kinase. Treatment with an ER-beta antisense oligonucleotide reduced cellular ER-beta mRNA and induced loss of expression of these genes. Sequence analysis revealed the presence of consensus NFkappaB sites, but not estrogen-responsive elements, in promoters of all four genes. Reporter assay and chromatin immunoprecipitation experiments demonstrated that ICI-induced gene expression could be mediated by crosstalk between ER-beta and the NFkappaB signaling pathway, denoting a novel mechanism of ER-beta-mediated ICI action. Therefore, combined therapies targeting ER-beta and NFkappaB signaling may be synergistic as treatment for PCa.
DOI of Published Version
Neoplasia. 2006 Apr;8(4):242-9. Link to article on publisher's site
Neoplasia (New York, N.Y.)
Leung, Yuet-Kin; Gao, Ying; Lau, Kin-Mang; Zhang, Xiang; and Ho, Shuk-Mei, "ICI 182,780-regulated gene expression in DU145 prostate cancer cells is mediated by estrogen receptor-beta/NFkappaB crosstalk" (2006). GSBS Student Publications. 676.