Bitter Melon Component and Colon Cancer Prevention

苦瓜成分与预防结肠癌

• 批准号: 9321795
• 负责人: Shrikant Anant
• 金额: $ 54.47万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9321795
• 关键词: 1-Phosphatidylinositol 3-Kinase; AKT1 gene; Adverse effects; Affect; Alleles; Alpha Cell; ApcMin/+ mice; Architecture; Biological Markers; Calmodulin; Cancer Etiology; Cells; Clinic; Clinical Research; Collaborations; Colon Carcinoma; Colonic Neoplasms; Colonic Polyps; Colorectal Cancer; DNA cassette; Data; Degradation Pathway; Diet; Dimensions; E2F1 gene; Endothelial Cells; Epithelial Cells; Fibroblasts; Future; Glycogen Synthase Kinase 3; Goals; Growth; Growth Factor; Health; Human; Intestines; JNK-activating protein kinase; Knock-out; LoxP-flanked allele; Lung; MAPK8 gene; Malignant Neoplasms; Mediating; Melons; Methods; Modeling; Morbidity - disease rate; Mus; Natural Products; Neoplasm Metastasis; Organ; PDPK1 gene; Pathway interactions; Pharmacology; Phosphorylation; Phosphotransferases; Prevention; Preventive; Protein-Serine-Threonine Kinases; Proteins; Proto-Oncogene Proteins c-akt; Recruitment Activity; Relapse; Role; Signal Transduction; Site; Stem cells; System; Testing; Therapeutic; Threonine; Ubiquitin; United States; adenoma; base; beta catenin; cancer cell; cancer prevention; cancer stem cell; cell growth; cell type; colon growth; cytokine; fruits and vegetables; in vivo; inhibitor/antagonist; killings; mortality; multicatalytic endopeptidase complex; mutant; novel; novel marker; overexpression; pre-clinical; preclinical study; prevent; public health relevance; screening; small hairpin RNA; tumor; tumor growth; tumor microenvironment; tumor xenograft; tumorigenesis; ubiquitin-protein ligase; villin

DESCRIPTION (provided by applicant): Despite the best screening efforts to identify and remove colon polyps, colon cancer remains a leading cause of cancer related morbidity and mortality, both in the US and around the world. Also, current therapeutics while good in removing most cancer cells are not adequate because they leave some cells behind. This is because these cells can reemerge and develop a fresh tumor, which in many cases can manifest in a different organ due to metastasis. The advantage of using natural products that originate from fruits and vegetables over synthetic agents for preventing cancer is that they promote human health without recognizable side effects. In this regard, we have recently shown that bitter melon extracts (BME) inhibit the growth of DCLK1+ cells. We have now discovered that charantin, an active ingredient in the extracts is a potent inhibitor of colon cancer growth. The goal of the current project is to further characterize charantin and generate preclinical data as a dietary agent for the prevention of colon cancer. In preliminary studies, we have determined that charantin inhibits DCLK1 kinase activity and that of a related kinase CAMKIIa but not that of CAMKIIb and CAMKIV. Furthermore, charantin inhibits DCLK1 induced phosphorylation of AKT1/PKB. AKT1 is a serine-threonine protein kinase that is catalytically inactive until it is phosphorylated at two critical sites, Thr308 and Ser473. Various agents such as growth factors, and cytokines can rapidly activate the protein through the actions of phosphatidylinositol 3-kinase (PI3K). Upon activation, AKT1 induces phosphorylation of GSK-3b and also inhibits JNK activation. We have determined that charantin suppresses AKT1 activation and induces JNK. Moreover, JNK induces b-catenin phosphorylation, which in turn is subjected to b-TRCP independent, SIAH1- dependent ubiquitin-proteasome degradation pathway. We have also determined that charantin inhibits the growth of colon cancer cells in a novel culture method termed "Tumor in a Dish" (TiD). In this system, cells are grown in a three dimensional matrix that contains normal lung cells including normal epithelial cells, fibroblasts and endothelial cells. The model creates a near-in vivo tumor microenvironment including cell-cell contact, 3D- architecture, and the influence of different cell types. The observed selective killing of cancer cells in this system suggests that the compounds are highly specific and have good potency. Based on these preliminary results, we propose to further develop charantin as a dietary prevention agent and move it towards the clinic. In aim 1, we propose to determine the role of PI3 kinase in charantin effect on DCLK1-mediated AKT1 activation. In Aim 2, we propose to determine whether charantin affects AKT-mediated �-catenin activation. Finally, in Aim 3, we will determine whether charantin induces JNK1 kinase and SIAH1 to induce �-catenin degradation. We will determine the effect of the compound on DCLK1 expression, and on Akt phosphorylation, and b-catenin degradation. These studies will also aid in understanding a non-canonical pathway to suppress b-catenin signaling and identify novel biomarkers for the future clinical studies.

描述(申请人提供)：尽管在识别和移除结肠息肉方面做出了最好的筛查努力，但结肠癌仍然是美国和世界各地癌症相关发病率和死亡率的主要原因。此外，目前的治疗方法虽然在去除大多数癌细胞方面很好，但还不够充分，因为它们会留下一些细胞。这是因为这些细胞可以重新出现并形成新的肿瘤，在许多情况下，由于转移，这种肿瘤可能会出现在不同的器官中。与合成试剂相比，使用来自水果和蔬菜的天然产品来预防癌症的优势在于，它们促进了人类健康，没有明显的副作用。在这方面，我们最近发现苦瓜提取物(BME)抑制DCLK1+细胞的生长。我们现在发现，提取物中的有效成分Charantin是一种有效的结肠癌生长抑制因子。当前项目的目标是进一步确定Charantin的特征，并产生作为预防结肠癌的饮食制剂的临床前数据。在初步研究中，我们已经确定Charantin抑制DCLK1和一种相关的激酶CAMKIIa的活性，但不抑制CAMKIIb和CAMKIV的活性。此外，Charantin还抑制DCLK1诱导的AKT1/PKB的磷酸化。AKT1是一种丝氨酸-苏氨酸蛋白激酶，在Thr308和Ser473这两个关键位点被磷酸化之前，其催化活性是不活跃的。生长因子和细胞因子等多种因子可以通过磷脂酰肌醇3-激酶(PI3K)的作用快速激活该蛋白。激活后，AKT1诱导GSK-3b的磷酸化，并抑制JNK的激活。我们已经确定，查兰丁抑制AKT1的激活，并诱导JNK。此外，JNK诱导b-连环蛋白的磷酸化，进而经历b-TRCP不依赖的、SIAH1依赖的泛素-蛋白酶体降解途径。我们还通过一种名为“盘中肿瘤”(TID)的新培养方法确定了Charantin抑制结肠癌细胞的生长。在这个系统中，细胞生长在三维基质中，其中包含正常的肺细胞，包括正常的上皮细胞、成纤维细胞和内皮细胞。该模型创造了一个接近体内的肿瘤微环境，包括细胞与细胞的接触、3D结构以及不同细胞类型的影响。在该系统中观察到的对癌细胞的选择性杀伤表明，这些化合物具有高度的特异性和良好的效力。基于这些初步结果，我们建议进一步开发查兰丁作为饮食预防药物，并将其推向临床。在目标1中，我们建议确定PI3激酶在查兰丁对DCLK1介导的AKT1激活中的作用。在目标2中，我们建议确定查兰丁是否影响AKT介导的�-连环蛋白的激活。最后，在目标3中，我们将确定Charantin是否诱导JNK1K和SIAH1诱导�-连环蛋白降解。我们将确定该化合物对DCLK1表达的影响，以及对Akt磷酸化和b-连环蛋白降解的影响。这些研究还将有助于理解抑制b-连环蛋白信号的非规范途径，并为未来的临床研究识别新的生物标记物。