AnnexinA2/progastrin and stem cells: dietary cancer prevention

膜联蛋白 A2/前胃泌素和干细胞：饮食癌症预防

• 批准号: 8527898
• 负责人: Pomila Singh
• 金额: $ 5.7万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-10 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8527898
• 关键词: ANXA2 gene; Aberrant crypt foci; Adenocarcinoma; Annexins; Apoptotic; Applications Grants; Attenuated; Azoxymethane; Binding; Biological Assay; CCKBR gene; CD44 gene; Cancerous; Cell Line; Cells; Cellular Membrane; Colon; Colon Carcinoma; Curcumin; Diagnostic; Diet; Dose; Down-Regulation; Epithelial; Epithelial Cells; Funding; Goals; Growth; Growth Factor; Image; In Vitro; Injectable; Intestinal Mucosa; Intestines; Investigation; Laboratories; Learning; Lesion; Luciferases; Malignant - descriptor; Malignant Neoplasms; Measures; Mediating; Membrane Proteins; Methods; Molecular; Monitor; Mucous Membrane; Mus; Neoplasm Metastasis; Neoplasms; Nude Mice; Organ; Patients; Peptides; Phase; Physiological; Plasmids; Prevention; Prevention strategy; Preventive; Progress Reports; Proteins; RNA; RNA Interference; Recurrence; Reducing Agents; Regimen; Relative (related person); Reporter; Reporting; Resistance; Risk; Seeds; Signal Pathway; Signal Transduction; Small Interfering RNA; Solid Neoplasm; Staining method; Stains; Stem cells; Testing; Therapeutic; Time; Transgenic Mice; Up-Regulation; adenoma; autocrine; base; cancer cell; cancer prevention; cancer stem cell; cancer therapy; cell transformation; chemo-dietary; colon carcinogenesis; dietary supplements; extracellular; feeding; in vivo; in vivo Model; nanoparticle; neoplastic; novel; p65; prevent; progastrin; promoter; public health relevance; receptor; research study; response; small hairpin RNA; stem cell population; tumor; tumorigenesis; tumorigenic

DESCRIPTION (provided by applicant): Cumulative evidence strongly suggests that precursor peptides such as progastrins (PG) exert mitogenic/co-carcinogenic effects on target cells and increase the risk of tumorigenesis. Many tumors express PG, and down-regulation of gastrin gene/PG expression attenuates growth of PG-dependent cancer cells. We recently discovered that extra-cellular membrane-associated annexin A2 (ANXA2) represents a novel receptor for PG. At the same time, ANXA2 expression has been reported to be critical for maintaining the growth of epithelial cancer cells. More recently, we discovered that over-expression of PG in HEK-293 cells significantly increased stem cell populations, positive for DCAMKL+1/Lgr5/CD44, and surprisingly resulted in tumorigenic transformation of the cells. In an important related study we reported potent inhibition of PG stimulated growth on cancer cells via the inhibition of critical signaling pathways. Our preliminary studies suggest that curcumin significantly reduces expression of ANXA2 and stem cell markers; intriguingly opposite effects of curcumin were measured on DCAMKL+1 expression in transformed versus non-transformed epithelial cells, Based on these novel findings we will test the hypothesis that 'chemo/dietary preventive agents differentially modulate growth factor-mediated expression of ANXA2 and stem cell markers in non-tumorigenic versus tumorigenic epithelial cells'. Towards this goal, we will focus on examining the effects of curcumin. In Aim 1, relative inhibitory efficacy of curcumin on growth of non-transformed/transformed epithelial cells, enriched for ANXA2/stem cell markers will be examined using in vitro and in vivo models of investigation. Regulatory effects of curcumin on expression of ANXA2/stem cell markers in non-tumorigenic/tumorigenic cells will be examined in relation to growth inhibitory effects of curcumin. Target-specific siRNA/shRNA against stem cell markers will be used to augment inhibitory effects of curcumin. Results of these studies will likely have therapeutic implications. In Aim 2 mechanisms by which curcumin reduces stimulatory effects of PG on the expression of ANXA2/stem cell markers will be examined in transformed/non-transformed cell lines at protein and RNA levels; inhibitory effects at the transcriptional level will be examined in promoter-reporter assays. These experiments will expand our understanding of the interplay between growth factors, curcumin and stem cell markers. In Aim 3, dose-dependent effects of dietary curcumin against initiation, promotion, and progression phases of colon carcinogenesis in transgenic mice over-expressing PG, in relation to efects on ANXA2/stem cell markers will be examined. Pre-neoplastic and neoplastic growths and surrounding normal mucosa wil be analyzed for relative expression of ANXA2/stem cell markers in relation to activation of 2- catenin/NF:Bp65 and other transcriptional factors. Results of these studies are expected to help us develop mechanism-based strategies for prevention and/or treatment of cancers in patients, positive for circulating PG (growth factors) and/or ANXA2 expressing tumors. PUBLIC HEALTH RELEVANCE: In this grant application it is proposed to examine if a combination of dietary supplements and non- toxic small inhibitory molecules can prevent or treat the growth of solid tumors and eradicate the seed cancer cells so that the threat of recurrence is significantly reduced. We will also examine the mechanisms by which specific molecules, discovered in the past few years by our laboratory, increase the risk of developing cancerous growths, and the mechanisms by which dietary agents reduce this risk. The results of these studies are expected to help us develop more effective strategies for preventing and treating solid tumors in organs such as the colon, using less toxic methods.

描述(由申请人提供)：累积证据有力地表明，孕激素(PG)等前体多肽对目标细胞具有促有丝分裂/协同致癌作用，并增加肿瘤发生的风险。许多肿瘤都表达PG，胃泌素基因/PG表达下调抑制了PG依赖性癌细胞的生长。我们最近发现，胞外膜相关膜联蛋白A2(ANXA2)是一种新的PG受体。同时，据报道，ANXA2的表达对维持上皮性癌细胞的生长至关重要。最近，我们发现PG在HEK-293细胞中的过度表达显著增加了干细胞数量，DCAMKL+1/Lgr5/CD44阳性，并意外地导致了细胞的致瘤转化。在一项重要的相关研究中，我们报道了PG通过抑制关键信号通路而有效地抑制癌细胞的生长。我们的初步研究表明，姜黄素显著降低ANXA2和干细胞标记物的表达；有趣的是，姜黄素对转化的和未转化的上皮细胞中DCAMKL+1的表达有相反的影响，基于这些新的发现，我们将检验这样的假设，即化疗/饮食预防药物以不同的方式调节生长因子介导的非致癌和致瘤的上皮细胞中ANXA2和干细胞标记物的表达。为了实现这一目标，我们将重点研究姜黄素的作用。在目标1中，将使用体外和体内研究模型来检测姜黄素对富含ANXA2/干细胞标志物的未转化/转化的上皮细胞生长的相对抑制效果。姜黄素对非致瘤/致瘤细胞ANXA2/干细胞标记物表达的调节作用将与姜黄素的生长抑制作用相关。针对干细胞标记物的靶向特异性siRNA/shRNA将被用于增强姜黄素的抑制作用。这些研究的结果可能会对治疗产生影响。在AIM中，姜黄素减少PG对ANXA2/干细胞标记物表达的刺激作用的机制将在蛋白质和RNA水平上被检测，在转录水平上的抑制效应将在启动子-报告实验中被检测。这些实验将扩大我们对生长因子、姜黄素和干细胞标记物之间相互作用的理解。在目标3中，将检测饮食姜黄素对过量表达PG的转基因小鼠结肠癌发生的起始、促进和进展阶段的剂量依赖效应，以及对ANXA2/干细胞标记物的影响。分析癌前病变、肿瘤生长和癌旁正常粘膜ANXA2/干细胞标记物的相对表达与2-连环蛋白/核因子：Bp65和其他转录因子的激活关系。这些研究的结果有望帮助我们开发基于机制的策略来预防和/或治疗循环PG(生长因子)和/或ANXA2表达阳性的肿瘤患者的癌症。 公共卫生相关性：在这项赠款申请中，建议研究膳食补充剂和无毒小抑制分子的组合是否可以预防或治疗实体肿瘤的生长，并根除种子癌细胞，从而显着降低复发的威胁。我们还将研究我们实验室在过去几年中发现的特定分子增加癌症生长风险的机制，以及饮食制剂降低这种风险的机制。这些研究的结果有望帮助我们开发更有效的策略，使用毒性较低的方法来预防和治疗结肠等器官的实体肿瘤。