Regulation of Prostate Cancer Growth by PPARg Ligands

PPARg 配体对前列腺癌生长的调节

• 批准号: 7101363
• 负责人: LaMonica Vanette Stewart
• 金额: $ 10.77万
• 依托单位: MEHARRY MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7101363
• 关键词: human; ligands; neoplastic cell; prostate neoplasms

DESCRIPTION (provided by applicant): The long-term goal of this project is to define how thiazolidinediones (TZDs) and other ligands for the peroxisome proliferator activated receptor gamma (PPARg) could be used clinically to treat patients with prostate cancer. Although PPARg ligands have been shown to reduce proliferation of human prostate cancer cells in vitro and inhibit prostate tumor growth in vivo, the mechanisms by which these reductions in proliferation and tumor growth occur are not fully understood. As a result, it is difficult to determine which patients would benefit from treatment regimens involving PPARg ligands. It is my hypothesis that TZDs and other PPARg ligands reduce prostate cancer cell proliferation by inhibiting the function of the androgen receptor (AR) as well as by inducing AR-independent alterations in gene expression. The experiments in this proposal are designed to test this hypothesis by examining the effects of TZDs such as ciglitazone on human prostate cancer cell lines both in vitro and in vivo. In Aim 1, we will define the mechanisms by PPARg ligands inhibit AR function in human prostate cancer cell lines. In this studies we will examine not only the effects of TZDs on androgen-induced gene expression but also the ability of TZDs to regulate the assembly of AR transcriptional complexes on chromatin. In Aim 2, we will test the hypothesis that PPARg ligands inhibit prostate cancer cell proliferation by altering expression of proteins that regulate cell cycle progression. To accomplish this aim, we will determine the importance of cyclin D1 down-regulation in TZDinduced decreases in cell proliferation. In addition we will explore whether TZDs induce expression of cyclin dependent kinase inhibitors and define the role of this up-regulation in the TZD anti-proliferative effect. In Aim 3, we will use an athymic mouse xenograft model to determine whether combination treatments involving PPARg ligands and vitamin D receptor agonists are effective at reducing growth of human prostate tumors in vivo. The data obtained from these studies will provide us with new information regarding the signaling pathways activated by PPARg ligands within human prostate cancer cells. In addition, these data will demonstrate how PPARg ligands can be used alone or in combination with other drugs to treat prostate cancer. This information can then be used to design prostate cancer treatments involving PPARg ligands that can be tested initially in animal models and then further explored in clinical trials.

描述（由申请人提供）：该项目的长期目标是定义过氧化物酶体增殖物激活的受体伽马（PPARG）如何在临床上使用噻唑烷二酮（TZD）和其他配体来治疗前列腺癌患者。尽管已显示PPARG配体在体外降低人前列腺癌细胞的增殖并抑制体内前列腺肿瘤的生长，但尚不完全了解这些降低和肿瘤生长中这些减少和肿瘤生长的机制。结果，很难确定哪些患者将从涉及PPARG配体的治疗方案中受益。我的假设是，TZD和其他PPARG配体通过抑制雄激素受体（AR）的功能以及诱导基因表达中AR非依赖性改变来减少前列腺癌细胞的增殖。该提案中的实验旨在通过检查诸如CIGLITAZONE等TZD对人类前列腺癌细胞系的影响，以检验该假设。在AIM 1中，我们将定义PPARG配体的机制抑制人类前列腺癌细胞系中的AR功能。在这项研究中，我们不仅将检查TZD对雄激素诱导的基因表达的影响，还将研究TZD调节AR转录复合物对染色质的组装的能力。在AIM 2中，我们将检验以下假设：PPARG配体通过改变调节细胞周期进展的蛋白质的表达来抑制前列腺癌细胞的增殖。为了实现这一目标，我们将确定细胞周期蛋白D1下调在细胞增殖减少中的重要性。此外，我们将探索TZD是否诱导细胞周期蛋白依赖性激酶抑制剂的表达，并定义该上调在TZD抗增殖作用中的作用。在AIM 3中，我们将使用无胸腺小鼠异种移植模型来确定涉及PPARG配体和维生素D受体激动剂的组合处理是否有效减少体内人类前列腺肿瘤的生长。从这些研究中获得的数据将为我们提供有关人类前列腺癌细胞中PPARG配体激活的信号传导途径的新信息。此外，这些数据将证明如何单独使用PPARG配体或与其他药物结合使用以治疗前列腺癌。然后，这些信息可用于设计涉及PPARG配体的前列腺癌处理，这些治疗最初可以在动物模型中进行测试，然后在临床试验中进一步探索。