title: Androgen signaling is a confounding factor for β-catenin-mediated prostate tumorigenesis.
abstract: Emerging evidence has demonstrated the critical roles for both androgen and Wnt pathways in prostate tumorigenesis. A recent integrative genomic analysis of human prostate cancers (PCas) has revealed a unique enrichment of androgen and Wnt signaling in early-onset PCas, implying their clinical significance in the disease. Additionally, interaction between the androgen receptor (AR) and β-catenin has long been detected in PCa cells. However, the consequence of this interaction in prostate tumorigenesis is still unknown. Because mutations in adenomatous polyposis coli, β-catenin and other components of the destruction complex are generally rare in PCas, other mechanisms of aberrant Wnt signaling activation have been speculated. To address these critical questions, we developed Ctnnb1(L(ex3)/+)/R26hAR(L/+):PB-Cre4 mice, in which transgenic AR and stabilized β-catenin are co-expressed in prostatic epithelial cells. We observed accelerated tumor development, aggressive tumor invasion and a decreased survival rate in Ctnnb1(L(ex3)/+)/R26hAR(L/+):PB-Cre4 compound mice compared with age-matched Ctnnb1(L(ex3)/+):PB-Cre4 littermate controls, which only have stabilized β-catenin expression in the prostate. Castration of the above transgenic mice resulted in significant tumor regression, implying an essential role of androgen signaling in tumor growth and maintenance. Implantation of the prostatic epithelial cells isolated from the transgenic mice regenerated prostate intraepithelial neoplasias and prostatic adenocarcinoma lesions. Microarray analyses of transcriptional profiles showed more robust enrichment of known tumor- and metastasis-promoting genes: Spp1, Egr1, c-Myc, Sp5, and Sp6 genes, in samples isolated from Ctnnb1(L(ex3)/+)/R26hAR(L/+):PB-Cre4 compound mice than those from Ctnnb1(L(ex3)/+):PB-Cre4 and R26hAR(L/+):PB-Cre4 littermate controls. Together, these data demonstrate a confounding role of androgen signaling in β-catenin-initiated oncogenic transformation in prostate tumorigenesis.
authors.affiliation: Department of Urology, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Comparative Medicine, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: R
authors.initials: R
authors.lastname: Luong
authors.affiliation: Department of Urology, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: D T
authors.initials: DT
authors.lastname: Johnson
authors.affiliation: Department of Urology, School of Medicine, University of California San Francisco, San Francisco, CA, USA.
authors.forename: G R
authors.initials: GR
authors.lastname: Cunha
authors.affiliation: Department of Urology, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: L
authors.initials: L
authors.lastname: Rivina
authors.affiliation: Department of Urology, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Gonzalgo
authors.affiliation: Department of Urology, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Sun
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000728:Androgens / Q000378:metabolism*; D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D008822:Mice, Transgenic; D019048:Prostatic Intraepithelial Neoplasia / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D015398:Signal Transduction / Q000235:genetics; D051176:beta Catenin / Q000235:genetics* / Q000378:metabolism
chemical_list: D000728:Androgens; D051176:beta Catenin