Bitter Melon Component and Colon Cancer Prevention

苦瓜成分与预防结肠癌

• 批准号: 8796002
• 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/8796002
• 关键词: 1-Phosphatidylinositol 3-Kinase; AKT1 gene; Adverse effects; Affect; Alleles; Architecture; Biological Factors; Biological Markers; Calmodulin; Cancer Etiology; Cells; Clinic; Clinical Research; Collaborations; Colon Carcinoma; Colonic Neoplasms; Colonic Polyps; Colorectal Cancer; Data; Degradation Pathway; Diet; E2F Transcription Factor 1; 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; Lead; Left; Lung; MAPK8 gene; Malignant Neoplasms; Mediating; Melons; Methods; Modeling; Morbidity - disease rate; Mus; Neoplasm Metastasis; Organ; PDPK1 gene; Pathway interactions; Phosphorylation; Phosphotransferases; Prevention; Preventive; Protein-Serine-Threonine Kinases; Proteins; Proto-Oncogene Proteins c-akt; Relapse; Role; Serine; Signal Transduction; Site; Stem cells; System; Testing; Therapeutic; Threonine; Ubiquitin; United States; adenoma; base; cancer cell; cancer prevention; cancer stem cell; cell growth; cell type; cytokine; fruits and vegetables; in vivo; inhibitor/antagonist; killings; mortality; multicatalytic endopeptidase complex; mutant; novel; overexpression; pre-clinical; preclinical study; prevent; public health relevance; screening; stress-activated protein kinase 1; 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（由适用提供）：尽管鉴定和去除结肠息肉做出了最好的筛查，但在美国和世界各地，结肠癌仍然是与癌症相关的发病率和死亡率的主要原因。同样，当前的理论虽然可以去除大多数癌细胞，但由于将某些细胞留在后面。这是因为这些细胞可以重新出现并发展出新鲜的肿瘤，在许多情况下，由于转移，该肿瘤可能在不同的器官中表现出来。使用源自水果和蔬菜而不是合成剂来预防癌症的天然产品的优点是，它们促进人类健康而没有可识别的副作用。在这方面，我们最近表明苦瓜提取物（BME）抑制了DCLK1+细胞的生长。我们现在发现，提取物中的活性成分Charantin是结肠癌生长的潜在抑制剂。当前项目的目的是进一步表征Charantin并生成临床前数据，作为预防结肠癌的饮食剂。在初步研究中，我们确定Charantin抑制了DCLK1激酶活性和相关激酶CAMKIIA的活性，但不具有Camkiib和Camkiv的活性。此外，Charantin抑制DCLK1诱导AKT1/PKB的磷酸化。 AKT1是一种丝氨酸 - 硫代蛋白激酶，在两个关键位点THR308和SER473上磷酸化，直到将其磷酸化为止。各种药物（例如生长因子）和细胞因子可以通过磷脂酰肌醇3-激酶（PI3K）的作用快速激活蛋白质。激活后，AKT1诱导GSK-3B的磷酸化并抑制JNK激活。我们已经确定Charantin抑制AKT1激活并诱导JNK。此外，JNK诱导B-蛋白磷酸化，而B-trcp独立于SIAH1依赖性泛素 - 蛋白酶体降解途径。我们还确定，在一种称为“菜肴中的肿瘤”（TID）的新培养方法中，Charantin抑制结肠癌细胞的生长。在该系统中，细胞在三维基质中生长，该基质包含正常的肺部细胞，包括正常的上皮细胞，成纤维细胞和内皮细胞。该模型创建了一个接近的体内肿瘤微环境，包括细胞 - 细胞接触，3D结构以及不同细胞类型的影响。观察到的该系统中癌细胞的选择性杀死表明这些化合物具有高度特异性并且具有良好的效力。基于这些初步结果，我们建议进一步发展Charantin作为饮食预防剂，并将其移至诊所。在AIM 1中，我们建议确定PI3激酶在Charantin效应对DCLK1介导的Akt1激活中的作用。在AIM 2中，我们建议确定Charantin是否影响Akt介导的 - 帕宁激活。最后，在AIM 3中，我们将确定Charantin是否诱导JNK1激酶和SIAH1诱导 - 催化性降解。我们将确定该化合物对DCLK1表达，AKT磷酸化和B-catenin降解的影响。这些研究还将有助于理解一种抑制B-catenin信号传导的非经典途径，并确定未来临床研究的新型生物标志物。