You have accessJournal of UrologyProstate Cancer: Basic Research II1 Apr 2010226 ENHANCED SENSITIVITY TO ANDROGEN WITHDRAWAL DUE TO OVEREXPRESSION OF INTERLEUKIN-6 IN ANDROGEN-DEPENDENT HUMAN PROSTATE CANCER LNCAP CELLS Tomoaki Terakawa, Hideaki Miyake, Junya Furukawa, Martin Gleave, and Masato Fujisawa Tomoaki TerakawaTomoaki Terakawa Kobe, Japan More articles by this author , Hideaki MiyakeHideaki Miyake Kobe, Japan More articles by this author , Junya FurukawaJunya Furukawa Kobe, Japan More articles by this author , Martin GleaveMartin Gleave Vancouver, Canada More articles by this author , and Masato FujisawaMasato Fujisawa Kobe, Japan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.284AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Interleukin-6 (IL-6) is a pleiotropic cytokine involved in the regulation of multiple pathophysiological functions. It has been suggested that crosstalk between androgen receptor (AR) and IL-6 may play an important role in the activation of AR signaling in a ligand-independent manner; however, it remains controversial whether IL-6 confers a malignant phenotype on prostate cancer cells, particularly under an androgen-deprived condition. The objective of this study was to investigate the effects of IL-6 overexpression in androgen-dependent prostate cancer LNCaP cells on their phenotype under an androgen-deprived condition. METHODS We established IL-6-overexpressing LNCaP (LNCaP/IL-6) by introducing the expression vector containing IL-6 cDNA. Changes in the phenotype in LNCaP/IL-6 before and after androgen withdrawal were compared with those in LNCaP transfected with control vector alone (LNCaP/Co). RESULTS In vitro, the growth of LNCaP/IL-6 was significantly inferior to that of LNCaP/Co under an androgen-deprived condition. Similarly, LNCaP/IL-6 tumor in nude mice rapidly regressed after castration; however, LNCaP/Co tumor growth was transiently inhibited after castration and then continuously accelerated. After androgen withdrawal, expression levels of phosphorylated p44/42 mitogen activated protein kinase (MAPK) and Akt in LNCaP/IL-6 were markedly upregulated compared with those in LNCaP/Co; however, additional treatment with specific inhibitor of the MAPK or Akt signaling pathway significantly inhibited the growth of LNCaP/IL-6 compared with that of LNCaP/Co, which might be due to the response to proapototic stimuli representing an adaptive cell survival mechanism. Furthermore, gene microarray analyses showed that androgen deprivation resulted in differential expression of genes which are known to have functions mediating cell growth, apoptotsis, and tumorigenesis, represeting expression profiles that are reasonable for theoretically elucidating the molecular mechanism underlying enhanced sensitivity to androgen withdrawal by overexpression of IL-6. CONCLUSIONS These findings suggest that excessive secretion of IL-6 by LNCaP cells in an autocrine manner may play a suppressive role in their growth and acquisition of androgen-independent phenotype under an androgen-deprived condition. © 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e88-e89 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Tomoaki Terakawa Kobe, Japan More articles by this author Hideaki Miyake Kobe, Japan More articles by this author Junya Furukawa Kobe, Japan More articles by this author Martin Gleave Vancouver, Canada More articles by this author Masato Fujisawa Kobe, Japan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...
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