Gardner, Sandra

5144 Background: The time course of testosterone (TST) recovery after prolonged androgen suppression (AS) is not well established. We examined TST recovery prospectively in prostate cancer (PCa) patients treated with 2 years of AS. Methods: 153 PCa men with pT3N0 or positive margins after radical prostatectomy (RP), or with PSA relapse (persistently detectable postoperative PSA [= 0.2 ng/mL], delayed detectable PSA = 6 months after surgery, or palpable/biopsy proven local recurrence after RP), were treated with radiation (RT) to the prostate bed (60 - 70 Gy in 30 - 35 fractions) plus 2 years of AS as part of a phase II study. AS consisted of nilutamide 100 mg PO tid for 4 weeks, starting within 1 week after completing RT, and busereline acetate 6.6 mg SC every 2 months for 2 years, starting within 2 weeks of nilutamide. The primary endpoint was PSA relapse-free survival. Serum TST levels were measured at baseline, every 4 months during AS, and every 6 months after completing AS. The planned sample size was 150 patients. Time to TST recovery was analyzed using the Kaplan-Meier method. Cox Proportional Hazards regression was used for a multivariate analysis of predictive factors for TST recovery. Results: 122 men completed the planned AS. Median follow up after finishing AS was 36.4 months (range 9.4 - 76.2). A castrate TST level was defined as =1.7 nmol/L (50 ng/dL), with normal levels being 10 - 40 nmol/L. All men achieved castrate TST levels on AS. Table 1 shows TST recovery at 36 months after completing AS and median times to recovery. Median recovery time to normal TST was 27 months, although 8% of men did not recover to above castrate levels by 3 years. On multivariate analysis, younger age (<60 vs. =60) predicted for a significantly shorter recovery time to normal TST (P = <0.0001), while baseline TST (<10 nmol/L vs. =10.0 nmol/L) was of borderline significance (P = 0.06). Conclusions: TST recovery after 2 years of AS is protracted. Older men have significantly longer recovery times. [Table: see text] [Table: see text]

AbstractGene regulation resulting from glucocorticoid receptor and glucocorticoid response element interactions is a hallmark feature of stress response signaling. Imbalanced glucocorticoid production and glucocorticoid receptor activity have been linked to socioeconomically crippling neuropsychiatric disorders, and accordingly there is a need to developin vivomodels to help understand disease progression and management. Therefore, we developed the transgenicSR4Gzebrafish reporter line with six glucocorticoid response elements used to promote expression of a short half‐life green fluorescent protein following glucocorticoid receptor activation. Herein, we document the ability of this reporter line to respond to both chronic and acute exogenous glucocorticoid treatment. The green fluorescent protein expression in response to transgene activation was high in a variety of tissues including the brain, and provided single‐cell resolution in the effected regions. The specificity of these responses is demonstrated using the partial agonist mifepristone and mutation of the glucocorticoid receptor. Importantly, the reporter line also modeled the temporal dynamics of endogenous stress response signaling, including the increased production of the glucocorticoid cortisol following hyperosmotic stress and the fluctuations of basal cortisol concentrations with the circadian rhythm. Taken together, these results characterize our newly developed reporter line for elucidating environmental or genetic modifiers of stress response signaling, which may provide insights to the neuronal mechanisms underlying neuropsychiatric disorders such as major depressive disorder.