Regulation of AR function by NOS

描述（由申请人提供）：NOS对AR功能的调节。雄激素受体（AR）是一种配体控制的转录因子，负责介导雄激素在靶问题中的所有生物作用，包括男性性发育和男性性特征的维持。AR基因的突变可导致雄激素不敏感综合征，影响正常的男性形态发生，而不受调节的AR信号与肯尼迪氏病的发展有关，肯尼迪氏病是一种影响下运动神经元的进行性退行性疾病。值得注意的是，基于临床和实验室的证据表明，AR在前列腺癌中起关键作用，前列腺癌是男性癌症死亡的第二大原因。最近的研究已经确定了AR中的激活突变，携带突变AR的转基因动物会发生前列腺上皮内瘤变，进而发展为浸润性前列腺癌。参与调节AR功能障碍的机制（因此，对人类疾病的贡献）仍然不完整。我们的初步数据显示，NOS在前列腺癌细胞中内源性表达，LNCaP细胞中过表达NOS可减弱雄激素诱导的AR激活，抑制体外细胞增殖和动物异种移植肿瘤生长。药物抑制NOS活性可增强体外雄激素调节的AR激活，用siRNA敲低NOS表达可增加AR与前列腺特异性抗原启动子的关联。AR与NOS形成复合物，并在翻译后被S-亚硝基化修饰（即NO基团与半胱氨酸残基的共价连接）。为了验证NOS及其产物NO调节AR功能控制前列腺癌细胞增殖的假说，我们提出了两个具体目标：[i]建立NOS表达、药理NOS抑制剂和NO供体对AR功能和前列腺细胞增殖的影响；[ii]阐明NOS和NO调节AR功能和前列腺细胞增殖的机制，重点是AR s -亚硝基化。NOS靶向活化或NO供体治疗有望成为成功治疗前列腺癌的特异性分子治疗工具。前列腺癌是美国男性癌症相关死亡的主要原因，雄激素受体参与了前列腺癌的发生和发展。我们发现雄激素受体被s -亚硝基化修饰，抑制其功能。靶向激活NOS，或使用NO供体治疗，可作为一种特异性分子治疗工具，成功治疗前列腺癌患者。

DESCRIPTION (provided by applicant): Regulation of AR Function by NOS. The androgen receptor (AR) is a ligand-controlled transcription factor that is responsible for mediating all biological actions of androgens in target issues, including male sexual development and maintenance of male sex characteristics. Mutations in the AR gene can cause the androgen-insensitivity syndrome that affects normal male morphogenesis, and unregulated AR signaling has been linked to the development of Kennedy's disease, a progressive degenerative condition affecting lower motor neurons. Significantly, clinical- and laboratory-based evidence demonstrates that AR plays a critical role in prostate cancer, the second leading cause of cancer death in men. Recent work has identified activating mutations in AR, and transgenic animals harboring the mutated AR develop prostatic intraepithelial neoplasia that progress to invasive prostate cancer. Mechanisms involved in the regulation of AR dysfunction (and, therefore, contribution to human disease) remain incomplete. Our preliminary data show that NOS is endogenously expressed in prostate cancer cells, and that overexpression of NOS in LNCaP cells attenuates the androgen-induced AR activation, and inhibits cell proliferation in vitro and xenograft tumor growth in animals. Pharmacologic inhibition of NOS activity enhances androgen-regulated AR activation in vitro, and knockdown of NOS expression with siRNA increases the AR association with prostate-specific antigen promoter. The AR forms a complex with NOS and is post-translationally modified by S- nitrosylation (i.e. the covalent attachment of a NO group to cysteine residue). We propose two specific aims to test the hypothesis that NOS and its product NO regulate AR function to control prostate cancer cell proliferation: [i] to establish effects of NOS expression and pharmacologic NOS inhibitors and NO donors on AR function, and prostate cell proliferation, and [ii] to elucidate the mechanisms by which NOS and NO regulate AR function and prostate cell proliferation with emphasis on AR S-nitrosylation. The targeted activation of NOS, or treatment with NO donors is hoped to serve as a specific molecular therapy tool to successfully treat prostate cancer. Prostate cancer is the leading cause of cancer-related death of American men, and androgen receptor is involved in the initiation and progression of the disease. We found that androgen receptor is modified by S-nitrosylation, which inhibits its function. The targeted activation of NOS, or treatment with NO donors may serve as a specific molecular therapy tool to successfully treat patients with prostate cancer.