Chemoprevention of colon cancer by targeting the Wnt/beta-catenin pathway

描述(由申请人提供)：结直肠癌是美国第三大常见癌症死亡原因。APC抑癌基因是结直肠癌发生发展的关键因素之一，也是Wnt/β-catenin信号通路的重要组成部分，是家族性腺瘤性息肉病(FAP)的致病因素。导致Wnt/？-catenin信号通路结构性激活的突变可能导致结肠癌。WNT(S)在调节细胞命运、增殖、迁移和死亡方面发挥着不同的作用。β-连环蛋白在许多类型的癌细胞中高度表达，并促进生长和肿瘤形成。在致癌模型系统和肿瘤组织中升高的β-连环素活性表明这种酶是化学预防的有效靶点。通过使用Bluegene/L和GPU超级计算机的计算生物学，我们已经鉴定/合成了几种高效或具有良好抑制结肠癌发生潜力的β-连环素小分子抑制剂。在这一应用中，我们建议使用最先进的技术来继续识别、表征、测试和验证新型的、无毒的β-连环蛋白小分子抑制剂。我们的方法包括确定结合、结合亲和力、识别特定的结合位点，并使用我们的超级计算机系统通过计算模拟来检查所产生的结构变化。我们将通过进行蛋白质结合分析、细胞转化分析和体内动物实验来验证这些抑制剂的有效性，包括异种移植模型和AOM诱导的结肠癌和APCMin小鼠模型。通过这些研究，我们将开发更有效的针对β-连环蛋白的药物，并减少副作用，用于结肠癌的化学预防。

DESCRIPTION (provided by applicant): Colorectal cancer (CRC) is the third most common cause of cancer death in the USA. Germline mutations in the apc tumor suppressor gene, one of the key players in the development of CRC and an important component in the Wnt/beta-catenin signaling pathway, are responsible for familial adenomatous polyposis (FAP). Mutations that result in constitutive activation of the Wnt/ß-catenin signaling pathway can lead to colon cancer. Wnt(s) have diverse roles in regulating cell fate, proliferation, migration, and death. beta-Catenin is highly expressed in many cancer cell types and promotes growth and tumor formation. Elevated beta-catenin activity in carcinogenesis model systems and neoplastic tissues suggests that this enzyme is a valid target for chemoprevention. By using computational biology with BlueGene/L and GPU supercomputers, we have identified/synthesized several small molecule inhibitors of beta-catenin that are highly effective or have good potential to suppress colon carcinogenesis. In this application, we propose to use state of the art technologies to continue to identify, characterize, test and validate novel, nontoxic small molecule inhibitors of beta-catenin. Our approaches include determination of binding, binding affinities, identification of the specific binding sites, and examining the resulting structural changes by computational simulation using our supercomputer systems. We will validate the effectiveness of these inhibitors by performing protein binding assays, cell transformation assays and in vivo animal experiments, including xenograft models and the AOM-induced colon cancer and APCMin mouse models. Through these studies, we will develop more effective agents targeting beta-catenin with fewer side effects for the chemoprevention of colon cancer.