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（由申请人提供）：尽管在识别和去除结肠息肉方面做出了最大的筛查努力，但在美国和世界各地，结肠癌仍然是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，但由于它们留下了一些细胞，因此是不够的。这是因为这些细胞可以重新出现并发展成新的肿瘤，在许多情况下，由于转移，新的肿瘤可以在不同的器官中表现出来。使用来自水果和蔬菜的天然产品预防癌症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，我们最近已经表明，苦瓜提取物（BME）抑制DCLK 1+细胞的生长。我们现在已经发现，charantin，提取物中的活性成分是结肠癌生长的有效抑制剂。当前项目的目标是进一步表征charantin并生成作为预防结肠癌的膳食剂的临床前数据。在初步研究中，我们已经确定charantin抑制DCLK 1激酶活性和相关激酶CAMKIIa的活性，但不抑制CAMKIIb和CAMKIV的活性。此外，charantin抑制DCLK 1诱导的AKT 1/PKB磷酸化。AKT 1是一种丝氨酸-苏氨酸蛋白激酶，其在两个关键位点Thr 308和Ser 473磷酸化之前是无催化活性的。各种试剂如生长因子和细胞因子可以通过磷脂酰肌醇3-激酶（PI 3 K）的作用快速激活蛋白质。一旦激活，AKT 1诱导GSK-3b的磷酸化，并且还抑制JNK激活。我们已经确定，charantin抑制AKT 1激活和诱导JNK。此外，JNK诱导b-连环蛋白磷酸化，这反过来又受到b-TRCP独立的，SIAH 1依赖的泛素-蛋白酶体降解途径。我们还确定，charantin抑制结肠癌细胞的生长在一种新的培养方法称为“肿瘤在一个盘子”（TiD）。在该系统中，细胞在三维基质中生长，所述三维基质含有正常肺细胞，包括正常上皮细胞、成纤维细胞和内皮细胞。该模型创建了一个接近体内的肿瘤微环境，包括细胞-细胞接触，3D结构和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该化合物是高度特异性的并且具有良好的效力。基于这些初步结果，我们建议进一步开发Charantin作为膳食预防剂，并将其推向临床。在目的1中，我们提出确定PI 3激酶在Charantin对DCLK 1介导的AKT 1活化的作用中的作用。在目标2中，我们建议确定Charantin是否影响AKT介导的？-连环蛋白激活。最后，在目标3中，我们将确定charantin是否诱导JNK 1激酶和SIAH 1诱导â-连环蛋白降解。我们将确定该化合物对DCLK 1表达、Akt磷酸化和β-连环蛋白降解的影响。这些研究也将有助于理解一个非经典的途径，以抑制b-连环蛋白信号传导，并确定新的生物标志物，为未来的临床研究。