Role of Protein (S14)in Normal and Neoplastic Mammary

蛋白质 (S14) 在正常和肿瘤乳腺中的作用

• 批准号: 6868885
• 负责人: WILLIAM B KINLAW
• 金额: $ 24.49万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2006-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6868885
• 关键词: DNA binding protein; MCF7 cell; apoptosis; athymic mouse; breast neoplasms; carcinogenesis; cell differentiation; cell proliferation; cyclins; fatty acid biosynthesis; fatty acid synthase; gel mobility shift assay; gene deletion mutation; gene expression; gene targeting; genetic promoter element; genetically modified animals; lactation; lipid metabolism; liver cells; mammary epithelium; neoplastic cell; nuclear proteins; nucleoproteins; oncogenes; protein metabolism; protein structure function; transcription factor

Abundant expression of enzymes of fatty acid synthesis occurs for each cycle of lactation and in a subset of aggressive breast cancers. S14 is a hormonally-inducible nuclear protein expressed only in tissues actively synthesizing lipids for use as a fuel (lactating mammary, liver, adipose), and is required for induction of genes coding lipogenic enzymes in response to hormonal and dietary signals. S14 is expressed in human mammary epithelium only during lactation, and we find it is critical for lipid metabolism, growth, and survival of mammary epithelial and lipogenic breast cancer cells. Genes coding S14 and Cyclin D1, a mammary oncogene that is also key for normal mammary development, both reside on the l lq13 cancer amplicon. In addition to S14 gene amplification, we find S14 overexpression in the majority of tumors, as is the case for cyclin D1. S14 expression correlates with that of a key lipogenic enzyme (acetyl-CoA carboxylase) in tumors, and is induced by progestin in breast cancer cells in concert with fatty acid synthase (FAS). This proposal is focused on the hypothesis that increased fatty acid synthesis in both lactating and malignant mammary cells is mediated by S14 and that this is critical for cell proliferation. We propose four specific aims: First, to define the impact of S14 expression on growth and metabolism of cells derived from normal mammary epithelium and from breast cancer. S14 expression and antisense genes will be introduced into HC11 lactating mouse mammary epithelial- and human breast cancer cells. Lipid synthesis, expression of lipogenic enzymes and their mRNAs, and growth/cell cycle effects will be analyzed in tissue culture and in xenografts in nude mice. Second, to define the functional interaction of S14 arid a key transcription factor (SREBP1c) that induces S14 and other genes for lipid synthesis and is also required for survival of lipogenic breast cancer cells. Regulation of FAS gene transcription by S14 and SREBP1c will be assessed by deletion analysis, and protein-DNA interactions will be identified. Third, to determine whether S14 drives mammary lipogenesis in vivo, and whether it acts as an oncogene, either alone or in cooperation with cyclin Dl. MMTV-S14 transgenic mice will be assessed metabolically and for tumorigenesis. In addition, MMTV-S14 mice will be crossed with a MMTV-cyclin D1 strain to determine if metabolism and/or virulence of cyclin D 1-induced tumors are influenced by S14. Fourth, to assess the role of S14 in mammary metabolism and development in mice with mammary-specific S14 gene disruption. These studies will provide a comprehensive view of the role of this novel nuclear protein in both normal mammary physiology and in breast cancer, and are likely to reveal a new class of therapeutic targets.

脂肪酸合成酶的丰富表达发生在每个哺乳周期和侵略性乳腺癌的子集中。 S14是一种荷尔蒙诱导的核蛋白，仅在组织中表达的脂质在组织中表达，以用作燃料（哺乳动物，肝脏，脂肪），并且是针对激素和饮食信号响应脂肪生成酶诱导基因的基因所必需的。 S14仅在哺乳期间才在人类乳腺上皮中表达，我们发现它对于乳腺上皮和脂肪生成乳腺癌细胞的脂质代谢，生长和存活至关重要。编码S14和Cyclin D1的基因，这是一种乳腺癌，也是正常乳腺发育的关键，都属于L lq13癌症扩增子。除了S14基因扩增外，我们还发现大多数肿瘤中的S14过表达，就像细胞周期蛋白D1一样。 S14的表达与肿瘤中的关键脂肪生物酶（乙酰辅酶A羧化酶）的表达相关，并与乳腺癌细胞中的孕激素诱导，并与脂肪酸合酶（FAS）一起诱导。该建议的重点是以下假设：泌乳和恶性乳腺细胞中脂肪酸的合成增加均由S14介导，这对于细胞增殖至关重要。我们提出了四个具体目标：首先，定义S14表达对正常乳腺上皮和乳腺癌的细胞生长和代谢的影响。 S14表达和反义基因将被引入HC11哺乳动物乳腺上皮和人类乳腺癌细胞中。脂质合成，脂肪生物的表达及其mRNA以及在组织培养和裸鼠的异种移植物中分析生长/细胞周期效应。其次，为了定义S14干旱的功能相互作用，即诱导S14和其他基因进行脂质合成的关键转录因子（SREBP1C），也是脂肪生成性乳腺癌细胞存活所必需的。 S14和SREBP1C对FAS基因转录的调节将通过缺失分析评估，并将确定蛋白-DNA相互作用。第三，确定S14是在体内驱动乳腺脂肪生成，以及它是否单独或与细胞周期蛋白DL合作起到癌基因。 MMTV-S14转基因小鼠将通过代谢和肿瘤发生评估。另外，将使用MMTV-Cyclin D1菌株跨越MMTV-S14小鼠，以确定细胞周期蛋白D 1诱导肿瘤的代谢和/或毒力是否受S14的影响。第四，评估S14在乳腺特异性S14基因破坏的小鼠中S14在乳腺代谢和发育中的作用。这些研究将对这种新型核蛋白在正常乳腺生理和乳腺癌中的作用提供全面的看法，并可能揭示新的一类治疗靶标。