Inhibition of breast cancer progression by vitamin D analogs and triterpenoids

描述（由申请人提供）： 乳腺癌发生的进展涉及信号通路和转录因子的大量改变。我们正在研究两种类型的核受体配体，一种新型维生素 D 受体配体（一种非高钙血症的 Gemini 维生素 D 类似物）和一种 PPARg 配体（一种独特的三萜类化合物），用于抑制乳腺癌进展。我们的初步数据表明，Gemini 维生素 D 类似物和三萜类化合物可调节 Smad 信号通路并协同抑制培养的 MCF10 乳腺癌细胞的增殖。我们假设 Gemini 维生素 D 类似物和三萜类化合物调节核受体信号传导和 TGF-b/Smad 系统，这些作用有助于抑制体内乳腺癌的进展。为了检验这一假设，我们计划实现以下具体目标：(1) 研究代表性 Gemini 维生素 D 类似物和三萜类化合物单独和组合在培养的 MCF10 乳腺癌细胞系（具有不同进展程度）中的分子机制，(2) 确定 Gemini 维生素 D 类似物和三萜类化合物在 MCF10 乳腺癌动物模型中的体内功效，并阐明所涉及的作用机制，(3) 验证Gemini 维生素 D 类似物和三萜类化合物在 MMTV-neu 雌激素受体 (ER) 阴性乳腺癌动物模型中的作用。为了研究这些药物对抗乳腺癌进展的体内功效和分子机制，我们将使用代表不同进展阶段的 MCF10 细胞系注射到免疫缺陷小鼠体内。我们将通过检查（a）核受体和共激活剂的相互作用，（b）转录激活和靶基因的调节，以及（c）Gemini维生素D类似物和MCF10乳腺细胞系中的三萜类化合物对Smad信号传导和翻译后修饰的调节来研究这些药物协同作用的分子机制。 MCF10乳腺癌异种移植模型和MMTV-neu乳腺癌转基因小鼠模型将用于确定Gemini维生素D类似物和三萜类化合物单独或组合在ER阴性乳腺癌中的体内功效。我们的提案重点是鉴定新型核受体配体作为抑制 ER 阴性乳腺癌的有希望的药物。这很重要，因为目前用于预防/治疗 ER 阴性乳腺癌的药物数量有限。我们对一种新型非高钙血症 Gemini 维生素 D 类似物和一种抑制乳腺癌进展的新型三萜类化合物的研究将为预防 ER 阴性乳腺癌提供重要的临床前数据。项目摘要/叙述 该提案旨在研究两种核受体配体、一种新型非高钙血症 Gemini 维生素 D 类似物和一种新型三萜类化合物，作为抑制乳腺癌形成和进展的药物。我们将研究这两种药物对核受体信号传导的调节，重点关注 TGF-b/Smad 信号传导途径，并确定它们在雌激素受体阴性乳腺癌进展动物模型中的体内疗效。我们预计通过 Gemini 维生素 D 类似物和独特的三萜类化合物的组合可以协同抑制乳腺癌的进展。这项研究将成为针对雌激素受体阴性乳腺癌高风险患者进行临床癌症预防试验的重要先驱。

DESCRIPTION (provided by applicant): Progression of mammary carcinogenesis involves numerous alterations in signaling pathways and transcription factors. We are studying two types of nuclear receptor ligands, a novel vitamin D receptor ligand (a non- hypercalcemic Gemini vitamin D analog) and a PPARg ligand (a unique triterpenoid), for inhibition of breast cancer progression. Our preliminary data show that Gemini vitamin D analogs and triterpenoids regulate the Smad signaling pathway and synergize to inhibit the proliferation of cultured MCF10 breast cancer cells. We hypothesize that Gemini vitamin D analogs and triterpenoids regulate nuclear receptor signaling and the TGF- b/Smad system, and these effects contribute to their inhibition of the progression of breast cancer in vivo. To test this hypothesis, we plan to pursue the following Specific Aims: (1) investigate the molecular mechanism of a representative Gemini vitamin D analog and a triterpenoid, alone and in combination, in cultured MCF10 breast cancer cell lines (with different degrees of progression), (2) determine the in vivo efficacy of a Gemini vitamin D analog and a triterpenoid in an animal model of MCF10 breast cancer and elucidate the mechanisms of action involved, and (3) verify the in vivo efficacy of the Gemini vitamin D analog and a triterpenoid in an animal model of MMTV-neu estrogen receptor (ER)-negative breast cancer. To study the in vivo efficacy and molecular mechanisms of these agents against breast cancer progression, we will use the MCF10 cell lines that represent different stages of progression when injected into immunodeficient mice. We will investigate the molecular mechanism of synergy of these agents by examining (a) interactions of nuclear receptors and coactivators, (b) regulation of transcriptional activation and target genes, and (c) regulation of Smad signaling and post-translational modification by a Gemini vitamin D analog and a triterpenoid in the MCF10 breast cell lines. The MCF10 breast cancer xenograft model and the MMTV-neu breast cancer transgenic mouse model will be used for determining in vivo efficacy of a Gemini vitamin D analog and a triterpenoid, alone and in combination, in ER-negative breast cancer. Our proposal focuses on the identification of novel nuclear receptor ligands as promising agents for the inhibition of ER-negative breast cancer. This is important because there are currently only a limited number of agents for the prevention/treatment of ER-negative breast cancer. Our research with a novel non-hypercalcemic Gemini vitamin D analog and a novel triterpenoid that inhibits breast cancer progression will provide important preclinical data for the prevention of ER-negative breast cancer.Project Summary/Narrative This proposal is to study two nuclear receptor ligands, a novel non-hypercalcemic Gemini vitamin D analog and a novel triterpenoid, as agents for inhibition of breast cancer formation and progression. We will investigate the regulation of nuclear receptor signaling with a focus on the TGF-b/Smad signaling pathway by these two agents, and we will determine their in vivo efficacy in animal models of estrogen receptor negative breast cancer progression. We anticipate finding synergistic inhibition of breast cancer progression by the combination of a Gemini vitamin D analog and a unique triterpenoid. This research will be an important precursor for a clinical cancer prevention trial in patients with a high risk of estrogen receptor negative breast cancer.