ANDROGEN RECEPTOR FUNCTION IN RECURRENT PROSTATE CANCER

（申请人说明）人类前列腺是雄激素依赖性的，前列腺癌（CaP）维持这种对雄激素的依赖性。雄激素停用后，CaP会发生凋亡和消退，但最终在没有雄激素的情况下复发。人类CaP异种移植物（CWR22）在雄性裸鼠中繁殖，保留了这些生物学特性，包括去势后的退化和在缺乏睾丸雄激素的几个月后的生长复发。雄激素刺激停止后，CWR22中的AR水平降低。然而，复发的CWR22肿瘤相对于去势小鼠的退化CWR22表达高水平的AR。在复发性CWR22中，核免疫染色强度的增加与缺乏雄激素的AR激活一致。此外，雄激素调节的mrna在阉割后CWR22肿瘤中减少，在复发的XWR22中上调。本研究的目的是建立AR和AR靶基因网络在CaP雄激素非依赖性生长中的作用。本项目的具体目的是：(1)描述CWR 22肿瘤去势和复发生长后AR mRNA和蛋白稳态表达水平的控制机制。表征复发性CWR22肿瘤中AR（蛋白稳定性和磷酸化）的激活特性。(2)确定CWR22中雄激素调节基因，重点研究ar刺激细胞生长的潜在介质。比较这些雄激素调控基因在CWR22中的表达水平，重点研究ar刺激细胞生长的潜在介质。比较这些雄激素调节基因在阉割小鼠中的表达水平。(3)利用显性阴性AR抑制AR抑制AR转激活，利用AR定向核酶阻止AR表达，确定AR在复发性CWR22肿瘤中雄激素无关的功能。(4)阐明雄激素调控基因在复发性CWR22 (a) ar依赖机制中的表达调控机制；或(b)非ar依赖机制。

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.