Dietary HDAC Inhibitors in Colon Cancer Prevention

膳食 HDAC 抑制剂预防结肠癌

• 批准号: 8009888
• 负责人: Roderick H Dashwood
• 金额: $ 29.43万
• 依托单位: OREGON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2013-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8009888
• 关键词: 1,2-Dimethylhydrazine; Adopted; Affect; Antioxidants; Apoptosis; Binding Sites; Biological Markers; Broccoli - dietary; Cell Cycle; Chemopreventive Agent; Chemoprotection; Chemoprotective Agent; Clinical Trials; Colon Carcinoma; Colonic Neoplasms; Colonoscopy; DNA; DNA Sequence; Development; Diet; Epigenetic Process; Event; Food; Garlic; Gene Expression; Gene Silencing; Genes; Growth; HT29 Cells; Health; Histone Acetylation; Histone Deacetylase; Histone Deacetylase Inhibitor; Histone deacetylase inhibition; Histones; Human; Human Volunteers; Immunoblotting; In Vitro; Individual; Ingestion; Intake; Intervention; Malignant Neoplasms; Mus; Mutation; Normal Cell; Organ; Parents; Pathway interactions; Patients; Pattern; Peripheral Blood Mononuclear Cell; Pre-Clinical Model; Promoter Regions; Proteins; Reporting; Repression; Response Elements; Role; Signal Transduction; Site; Small Interfering RNA; Sp1 Transcription Factor; Sp3 Transcription Factor; Staging; Sulforaphane; Testing; Therapeutic; Therapeutic Agents; Translating; Tumor Suppression; Tumor Suppressor Genes; United States National Institutes of Health; Work; allyl sulfide; cancer cell; cancer prevention; cancer therapy; cell suicide; colorectal cancer screening; effective intervention; human subject; in vivo; inhibitor/antagonist; innovation; interest; liquid chromatography mass spectrometry; novel; oncoprotein p21; promoter; research study; response; translational study

DESCRIPTION (provided by applicant): This application responds to PA-06-412 "Diet, epigenetic events & cancer prevention" by focusing on food components that act as histone deacetylase (HDAC) inhibitors. HDAC inhibitors are receiving increasing interest as cancer therapeutic agents, with the realization that histone acetylation is altered in many cancers. Potent HDAC inhibitors `de- repress' epigenetically silenced genes, such as P21/WAF1, through Sp1/Sp3 transcription factor binding sites in the corresponding gene promoters, causing growth arrest/apoptosis in cancer cells. The PI has proposed that dietary HDAC inhibitors might act similarly in the therapeutic setting, but because of their regular ingestion in foods they also serve a chemopreventive role via epigenetic `priming' of gene expression in normal cells. The CENTRAL HYPOTHESIS is that sulforaphane (SFN) from broccoli and organosulfur compounds from garlic are effective chemopreventive agents because the parent compound(s) activate Nrf2/ARE signaling whereas the metabolites inhibit HDAC activity, thereby de-repressing genes such as P21 that regulate the cell cycle and apoptosis. By acting through Sp1/Sp3 sites in gene promoters, HDAC inhibitory effects of dietary agents can occur independently of the Nrf2/ARE pathway. Aims 1-3 are sequential, starting with individual dietary compounds and HDAC inhibitor mechanisms in human colon cancer cells (Aim 1), followed by colon tumor suppression studies in vivo (Aim 2), and combined agents in vivo (Aim 3A,B), ending with translational studies in humans (Aim 3C). Aim 1. In human colon cancer cells, define the specific HDACs that associate with the promoter region of the P21 gene, and the changes in these HDACs following treatment with dietary HDAC inhibitors. Using immunoblotting, ChIP/re-ChIP, qRT-PCR and siRNA knockdown, systematically examine HDACs associated with the promoter region of P21, their de-recruitment in response to dietary HDAC inhibitors, and the role of specific transcription factors (Sp1, Sp3) in de-repressing p21, in HT29 cells treated with SFN (Aim 1A) or garlic compounds (Aim 1B). Aim 2. Test the hypothesis that, post-initiation, dietary HDAC inhibitors increase histone acetylation and de- repress p21, thereby suppressing colon tumor formation in 1,2-dimethylhydrazine (DMH)-treated mice. Show that tumor suppression is correlated with HDAC inhibition, induction of acetylated histones, and de-repression of p21 in mice given SFN (Aim 2A) or garlic organosulfur compounds (Aim 2B). Aim 3. Examine the cooperative effects of SFN and garlic compounds as dietary HDAC inhibitors in mice, and translate the findings into human volunteers, using a `whole food' approach that combines SFN-rich broccoli sprouts and garlic oil supplements. Show that SFN and garlic compounds cooperate to suppress DMH- induced colon tumors in mice (Aim 3A), and cause HDAC inhibition and histone hyperacetylation in normal cells of the mouse (Aim 3B), i.e. in peripheral blood mononuclear cells (PBMCs). Test the hypothesis that, in human volunteers, broccoli sprouts and garlic oil supplements cause HDAC inhibition and histone hyperacetylation in PBMCs (Aim 3C). Unlike genetic changes associated with cancer, epigenetic changes are potentially modifiable; thus, HDAC inhibitory effects of dietary agents are worthy of study, with implications for cancer prevention and treatment. PUBLIC HEALTH RELEVANCE: Cancer development is often considered in terms of genetic alterations in the DNA sequence (i.e. mutations), but recent work has implicated so-called `epigenetic' changes. The latter involve reversible alterations in the proteins that associate with DNA, and affect how genes are turned `on' or `off'. This project examines how chemoprotective factors in broccoli and garlic, working through epigenetic mechanisms, can turn on tumor suppressor genes, thereby causing colon cancer cells to halt their growth and/or rapidly undergo cell suicide.

描述（由申请人提供）： 该应用对PA-06-412的反应“饮食，表观遗传事件和预防癌症预防”，通过专注于充当组蛋白脱乙酰基酶（HDAC）抑制剂的食物成分。 HDAC抑制剂正在接受癌症治疗剂的兴趣，并意识到许多癌症在许多癌症中都改变了组蛋白乙酰化。有效的HDAC抑制剂通过SP1/SP3转录因子结合位点在相应基因启动子中通过SP1/SP3转录因子结合位点表观遗传沉默的基因，例如P21/WAF1，从而导致癌细胞中的生长停滞/凋亡。 PI提出，饮食中的HDAC抑制剂可能在治疗环境中的作用类似，但是由于它们在食品中的定期摄入，它们也通过正常细胞中基因表达的表观遗传学“启动”发挥化学预防作用。中心假设是，来自西兰花和大蒜的有机硫化合物的硫烷（SFN）是有效的化学预防剂，因为母体化合物激活NRF2/是信号传导，而代谢物却抑制了HDAC活性，从而抑制了HDAC的活性，从而使P21诸如P21这样的细胞循环和Apoptscision和Apoptscission抑制了p21的p21。通过通过基因启动子中的SP1/SP3位点起作用，饮食剂的HDAC抑制作用可以独立于NRF2/是途径。 AIM 1-3是顺序的，从人类结肠癌细胞中的个别饮食化合物和HDAC抑制剂机制开始（AIM 1），然后在体内进行结肠肿瘤抑制研究（AIM 2），并在体内联合剂（AIM 3A，B）（AIM 3A，B），以人类的转化研究（AIM 3C）。目的1。在人类结肠癌细胞中，定义与p21基因启动子区域相关的特定HDAC，以及用饮食中HDAC抑制剂治疗后这些HDAC的变化。使用免疫印迹，芯片/重新芯片，QRT-PCR和siRNA敲低，系统地检查与p21的启动子区域相关的HDAC，其对饮食中HDAC抑制剂的恢复率以及在DE-P21中的特定转录因子（SP1，SP3）的作用（SP1，SP3）在HT29中的组合或ht29细胞中的作用（SP1，SP3）的作用（SP1，SP3） 1b）。 AIM 2。测试饮食后HDAC抑制剂增加组蛋白乙酰化和抑制P21的假设，从而抑制了1,2-二甲基氢嗪（DMH）治疗的小鼠的结肠肿瘤形成。表明肿瘤抑制与HDAC抑制作用，乙酰化组蛋白的诱导以及给定SFN（AIM 2A）或大蒜有机硫化化合物的小鼠中P21的抑制（AIM 2B）相关。 AIM 3。将SFN和大蒜化合物作为小鼠的饮食HDAC抑制剂的合作作用，并使用一种结合了富含SFN的西兰花芽孢杆菌芽和大蒜油补充剂的“全食”方法将发现转化为人类志愿者。表明SFN和大蒜化合物合作抑制小鼠诱导的DMH诱导的结肠肿瘤（AIM 3A），并在小鼠正常细胞中引起HDAC抑制和组蛋白高乙基化（AIM 3B）（即外周血液单核细胞中）（PBMC）。检验以下假设：在人类志愿者中，西兰花芽和大蒜油补充剂在PBMC中引起HDAC抑制和组蛋白高乙酰化（AIM 3C）。与癌症相关的遗传变化不同，表观遗传变化可能会改变。因此，饮食剂的HDAC抑制作用值得研究，对预防癌症和治疗产生了影响。公共卫生相关性：通常根据DNA序列的遗传改变（即突变）来考虑癌症的发展，但最近的工作暗示了所谓的“表观遗传”变化。后者涉及与DNA相关的蛋白质的可逆变化，并影响基因如何打开或“ OFF”。该项目研究了通过表观遗传机制工作的西兰花和大蒜中的化学保护因子如何打开肿瘤抑制基因，从而导致结肠癌细胞停止其生长和/或迅速进行细胞自杀。