each used to generate a series of 6 tissue microarrays. Immunohisto-chemistry with AR antisera was scored in ��3 fields of each core bytwo researchers, and collapsed into sample scores of 0–9 in epithelia0–6 in stroma for both PCa and BPH. Associations between AR scoreand clinical parameters (Gleason, serum PSA, % cancer, prostate size,stage and cancer related death) was investigated using data dichoto-mized by median AR in each compartment/tissue using Wilcox RankSum and Barnard’s Exact tests. Significance was set at p�0.05.

RESULTS: In epithelia, median AR levels were similar in bothPCa and BPH (p�0.77), but for stroma was 3.2 fold lower in PCa(p�5.6e-6). High epithelial AR and conversely low stromal AR wereindependently associated in PCa samples with Gleason grade and %cancer (p�0.03). Serum PSA was related only to high AR content inPCa epithelium (p�0.03). Critically, we report here for the first time thatPCa associated death was associated exclusively with low stromal ARcontent (p�0.04).

CONCLUSIONS: These results are consistent with a model ofPCa in which a breakdown in AR signaling in both epithelial and stromalcells contributes to progression. High epithelial AR is consistent withandrogens driving proliferation and PSA production, and low stromalAR with a protective role of stromal androgen action in the prostatemicroenvironment. Importantly, we have identified a unique relationshipbetween low stromal AR and PCa associated death. By unlocking thehidden role of stroma in PCa outcome, we can potentially enhance ourcapacity to distinguish lethal from indolent disease, improve options forpatients, and identify new treatment modalities.

Source of Funding: Foundation Daw Park Research Grant,Flinders University 2010 Seeding Grant, Prostate CancerFoundation of Australia,National Health and Medical ResearchCouncil of Australia; Freemasons Foundation Centre for Men’sHealth

613IMMEDIATE, COMPARED TO DEFERRED, COMBINEDANDROGEN BLOCKADE PROLONGS TIME TOCASTRATE-RESISTANT LNCAP PROSTATE CANCERPROGRESSION IN VIVO

Hidetoshi Kuruma*, Kilian Gust, Hiroaki Matsumoto, Amina Zoubeidi,Chirstian Thomas, Francois Lamoureux, Martin Gleave,Vancouver, Canada

INTRODUCTION AND OBJECTIVES: Androgen deprivationtherapy is standard for advanced prostate cancer (PCa). Combinedandrogen blockade (CAB) refers to surgical or medical castration plusan anti-androgen is considered maximum androgen blockade therapy.However, there is no consensus about optimal timing of anti-androgeninduction after castration. In this study, we compared effects of imme-diate vs. delayed administration of bicalutamide after castration on timeto castrate-resistant LNCaP tumor growth.

METHODS: Androgen dependent human prostate cancerLNCaP cells were inoculated into male athymic nude mice subcutane-ously. Serum PSA level and tumour volumes were followed weekly.When serum PSA values reached 50ng/ml, mice were castrated anddivided into 3 groups including immediate CAB, CAB after progressionto castration resistance (deferred CAB), or vehicle-only dosing.50mg/kg of bicalutamide was used as an anti- androgen.

RESULTS: Forty one mice entered this study. Averages of PSAand tumour volume were similar prior to castration in all three groups.In the immediate CAB group, PSA declined to �91.2% from baseline 2weeks after CAB, compared to �64.6% for vehicle. In the deferred CABgroup, PSA declined �50.4% by 1W after castration, and returned topre-castration levels at 4 weeks. By 12 weeks post-castration, PSAlevels were �29.0%, �197.0% and �118.1% from baseline for theimmediate CAB, deferred CAB and vehicle groups, respectively. PSAlevels in the immediate CAB group were significantly lower than de-ferred CAB (p�0.04 at 12 weeks). Tumor volume in the immediate CABgroup decreased �10.2% at 2 weeks after CAB, while tumor volume inthe deferred CAB and vehicle-only groups continued to increase post-

castration. By 12 weeks after castration, tumor volume increased by�98.2%, �307.4% and �546.9% from base line for immediate CAB,deferred CAB and vehicle groups, respectively.

CONCLUSIONS: Immediate CAB, at time of first-line castra-tion, prolonged time to recurrence compared deferred CAB in theandrogen-sensitive LNCaP models, and has ongoing implications tothe clinical disease as more potent anti-androgens are under develop-ment.

Source of Funding: None

6145�-REDUCTASE TYPE 3 EXPRESSION IN HUMAN BENIGN ANDMALIGNANT TISSUES: A COMPARATIVE ANALYSIS DURINGPROSTATE CANCER PROGRESSION

Alejandro Godoy, Elzbieta Kawinski, Yun Li, Daizo Oka, BorislavAlexiev, Faris Azzouni*, Mark Titus, James Mohler, Buffalo, NY

INTRODUCTION AND OBJECTIVES: A third isozyme of hu-man 5a-steroid reductase, 5a-reductase-3, was identified in prostatetissue at the mRNA level. However, the levels of 5a-reductase-3 proteinexpression and its cellular localization in human tissues remain un-known.

METHODS: A specific monoclonal antibody was developed,validated, and used to characterize for the first time the expression of5a-reductase-3 protein in 18 benign and 26 malignant human tissuetypes using immunostaining analyses.

RESULTS: In benign tissues, 5� -reductase-3 immunostainingwas high in conventional androgen-regulated human tissues, such asskeletal muscle and prostate. However, high levels of expression alsowere observed in non-conventional androgen-regulated tissues, whichsuggest either multiples target tissues for androgens or different func-tions of 5�-reductase-3 among human tissues. In malignant tissues,5�-reductase-3 immunostaining was ubiquitous but particularly over-expressed in some cancers compared to their benign counterparts,which suggests a potential role for 5�-reductase-3 as a biomarker ofmalignancy. In benign prostate, 5�-reductase-3 immunostaining waslocalized to basal epithelial cells, with no immunostaining observed insecretory/luminal epithelial cells. In high-grade prostatic intraepithelialneoplasia (HGPIN), 5�-reductase-3 immunostaining was localized inboth basal epithelial cells and neoplastic epithelial cells characteristic ofHGPIN. In androgen-stimulated and castration-recurrent prostate can-cer (CaP), 5�-reductase-3 immunostaining was present in most epi-thelial cells and at similar levels, and at levels higher than observed inbenign prostate.

CONCLUSIONS: Analyses of expression and functionality of5� -reductase-3 in human tissues may prove useful for development oftreatment for benign prostatic enlargement and prevention and treat-ment of CaP.

Source of Funding: This work was supported by the NationalCancer Institute at the National Institutes of Health PO1-CA77739 (J. L. Mohler), National Cancer Institute CancerCenter Support Grants CA016156 and CA034026 to RoswellPark Cancer Institute and University of North Carolina,respectively, and Department of Defense Grant W81XWH-08-1-0330 (A. Godoy).

615HSP27 INHIBITION ACTIVATES THE UNFOLD PROTEINRESPONSE AND AUTOPHAGY PATHWAY THROUGHINHIBITION OF PROTEASOME ACTIVITY INPROSTATE CANCER

Masafumi Kumano*, Vancouver, Canada; Junya Furukawa, Kobe,Japan; Amina Zoubeidi, Shiota Masaki, Eliana Beraldi, MartinGleave, Vancouver, Canada

INTRODUCTION AND OBJECTIVES: Hsp27 is induced byaccumulation of unfolded protein aggregates following various stress

Vol. 185, No. 4S, Supplement, Sunday, May 15, 2011 THE JOURNAL OF UROLOGY� e247