ANDROGEN RECEPTOR FUNCTION IN RECURRENT PROSTATE CANCER

描述：（申请人的描述）人前列腺是雄激素依赖性的，前列腺癌（CaP）维持对雄激素的这种依赖。CaP在雄激素戒断后经历凋亡和消退，但最终在睾丸雄激素缺乏的情况下复发。在雄性裸鼠中繁殖的人CaP异种移植物（CWR 22）保留了这些生物学特征，包括在睾丸雄激素不存在的情况下去势后的退化和几个月后的生长复发。在雄激素刺激撤销后，CWR 22中的AR水平降低。然而，复发性CWR 22肿瘤相对于来自去势小鼠的消退CWR 22表达高水平的AR。在复发性CWR 22中，核免疫染色强度的增加与雄激素不存在下的AR激活一致。此外，去势后CWR 22肿瘤中减少的雄激素调节的mRNA在复发性XWR 22中上调。本研究的目的是确定AR和AR靶基因网络在CaP雄激素非依赖性生长中的作用。本课题的具体目的是：（1）阐明CWR 22肿瘤去势后和复发生长后AR mRNA和蛋白稳态表达水平的调控机制。表征复发性CWR 22肿瘤中AR的活化特性（蛋白质稳定性和磷酸化）。(2)确定CWR 22中雄激素调节的基因，重点是AR刺激细胞生长的潜在介质。比较CWR 22中这些雄激素调节基因的表达水平，重点是AR刺激细胞生长的潜在介质。比较去势小鼠中这些雄激素调节基因的表达水平。(3)使用显性阴性AR抑制AR以抑制AR反式激活和AR定向核酶阻止AR表达来确定AR在复发性CWR 22肿瘤中的雄激素非依赖性功能。(4)阐明复发性CWR 22中控制雄激素调节基因表达的机制（a）AR依赖性机制;或（B）非AR依赖性机制。

Description: (Applicant's Description) The human prostate is androgen dependent and prostate cancer (CaP), maintains this dependence on androgens. CaP undergoes apoptosis and regression following androgen withdrawal but eventually recurs in the absence of testicular androgens. The human CaP xenograft (CWR22) propagated in male nude mice, retains these biological characteristics including regression following castration and recurrence of growth after several months in the absence of testicular androgen. Following the withdrawal of androgen stimulation, AR levels decrease in CWR22. However, recurrent CWR22 tumors express high levels of AR relative to the regressing CWR22 from castrated mice. In recurrent CWR22 the increased intensity of nuclear immunostaining is consistent with AR activation in the absence of androgen. Moreover, androgen-regulated mRNAs that decrease in CWR22 tumors following castration are up-regulated in the recurrent XWR22. The goal of this research is to establish the role of AR and the AR target gene network in the androgen-independent growth of CaP. Specific Aims of this project are to: (1) Delineate the mechanisms controlling steady state expression levels of AR mRNA and protein in CWR 22 tumors after castration and recurrent growth. Characterize the activation properties of AR (protein stability and phosphorylation) in recurrent CWR22 tumors. (2) Identify androgen-regulated genes in CWR22 with emphasis on potential mediators of AR-stimulated cell growth. Compare the levels of expression of these androgen-regulated genes in CWR22 with emphasis on potential mediators of AR-stimulated cell growth. Compare the levels of expression of these androgen- regulated genes in castrate mice. (3) Determine the androgen-independent function of AR in the recurrent CWR22 tumors using a dominant- negative AR to inhibit AR to inhibit AR transactivation and an AR- directed ribozyme to prevent AR expression. (4) Elucidate the mechanism controlling expression of androgen-regulated genes in the recurrent CWR22 (a) AR-dependent mechanism; or (b) non-AR dependent mechanism.