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Signaling and Regulation

Wwox Suppresses Prostate Cancer Cell Growth through Modulation of ErbB2-Mediated Androgen Receptor Signaling

Department of Molecular Virology, Immunology and Medical Genetics, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio

^* To whom correspondence should be addressed. E-mail: kay.huebner{at}osumc.edu.

	Abstract

The expression of the WWOX tumor suppressor gene is lost or reduced in a large fraction of various cancers, including prostate cancer. We previously reported that Wwox overexpression induced apoptosis and suppressed prostate cancer growth in vitro and in vivo. In this study, pathways through which Wwox contributes to control of prostate cancer cell growth have been investigated. We found that Wwox interacts with Ap2 and prevents it from entering the nucleus to bind the ERBB2 promoter region to activate transcription of ERBB2, a mediator of androgen receptor activity and prostate cancer cell growth at limiting androgen concentration. Ectopic expression of Wwox reduced ErbB2 protein expression in vitro and expression of Wwox protein inversely correlated with expression of ErbB2 protein in prostate cancer tissues. Furthermore, Wwox suppressed Ap2/ErbB2–induced prostate cancer cell growth and suppressed prostate-specific antigen secretion through interaction with Ap2 and down-modulation of ErbB2, an effect that required functional androgen receptor. (Mol Cancer Res 2007;5(9):957–65)

Key Words: prostate cancer suppression, Wwox, ErbB2, Ap2, androgen receptor