Heterogeneity of Human Colon Carcinoma

人类结肠癌的异质性

基本信息

批准号：
8390515
负责人：
MICHAEL G BRATTAIN
金额：
$ 28.8万
依托单位：
UNIVERSITY OF NEBRASKA MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
1982
资助国家：
美国
起止时间：
1982-02-01 至 2014-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8390515
关键词：
Active Sites Apoptosis Cancer Model Cancer Patient Catalytic Domain Cell Surface Receptors Cell Survival Cells Clinical Colon Carcinoma Colonic Neoplasms Colorectal Cancer Development Dominant-Negative Mutation Ectopic Expression Elements Enzymes Exposure to Family Genes Growth Factor Heterogeneity Human Intervention Investigation Lead Link Liver Lung Malignant - descriptor Mediating Mediator of activation protein Modification Molecular Target Mutation Neoplasm Metastasis PI3K/AKT PIK3CA gene Pathway interactions Patients Phenotype Phosphatidylinositol 4,5-Diphosphate Phosphorylation Proto-Oncogene Proteins c-akt Resistance Sampling Signal Transduction Site Small Interfering RNA Stress Subgroup Testing autocrine base cell type colon cancer cell line enzyme activity gain of function mutation malignant breast neoplasm meetings mutant novel strategies outcome forecast receptor receptor expression therapeutic target tumor tumor progression

项目摘要

ABSTRACT We have identified a panel of colon cancer cell lines with PIK3CA gain of function mutations and have shown they are closely associated with cell survival and metastases from orthotopic primary colon tumors to the liver and lung. These mutations have recently been shown to predict for poor survival in both colorectal and breast cancer. The objectives of this competing renewal application are to characterize the basis for the mutant PI3K contribution to survival and malignant progression and to identify signaling effects both upstream and downstream of the mutants that contribute to survival and metastatic colonization. This line of investigation is expected to lead to the identification of strategies for matching appropriate targeting agents to the subgroup of colorectal cancer patients bearing these mutations and to allow for further refinement of patient subgroups from among the patients with p110¿ mutations. We have noted in that knockdown of the cell surface receptor RONK (Met family receptor) results in loss of signaling by the H1407R mutant under stress conditions and inhibition of metastasis from an orthotopic colon cancer model. Thus, in Aim 1 the hypothesis that activation of PI3K mutants is linked to RONK autocrine activity will be tested. The understanding of this issue is potentially important to the development of novel strategies of intervention independent of, or complementary to, direct attack upon mutant PI3K p110¿ catalytic subunits. Specific Aim II will test the hypothesis that cell survival signaling through Bax and pBad is a critical element for imparting the metastatic phenotype to cells bearing these mutations. This hypothesis will be tested by utilizing siRNA and dominant negative approaches to determine critical survival targets for metastasis from among the several AKT substrate-related mechanisms that co-exist during stress conditions in these cells. Specific Aim III will determine whether ectopic expression of the mutant enzymes in cells bearing only the wild type gene will generate similar mechanisms of survival and metastasis. We will also characterize the relationship between the PLC¿ mediated mechanisms of cell survival with that of the mutant PI3K/AKT pathway. The hypothesis that both are invoked by exposure to stress and act simultaneously on the modification of Bad to enable metastasis will be tested. PLC¿ and AKT are linked by competition for the same substrate and are often inhibitory to each other. Despite this they are simultaneously effective for cell survival signaling in the presence of the mutant PIK3CA's, but not in wild type cells. We will test the hypothesis that mutant PI3K allows for greater catalytic efficiency at low ATP concentrations that in turn provides sufficient product to satisfy the needs of both pathways. Specific Aims are: I. Determine if autocrine growth factor activity is required for mutant PIK3CA mediated metastasis. II. Determine whether Bax degradation and Bad phosphorylation by mutant PIK3CA's are necessary for metastasis. III. Determine the effects of different PIK3CA mutations on cell survival signaling and metastatic capability.

抽象的我们已经鉴定了一组具有 PIK3CA 功能获得性突变的结肠癌细胞系，并已研究表明它们与细胞存活和原位原发性结肠肿瘤转移密切相关最近显示，这些突变可以预测结直肠和肺的生存率较差。这项竞争性更新申请的目的是表征突变体的基础。 PI3K 对生存和恶性进展的贡献，并确定上游和下游的信号传导效应有助于生存和转移定植的突变体的下游。预计将导致确定将适当的靶向剂与亚组相匹配的策略携带这些突变的结直肠癌患者，并允许进一步细化患者亚组来自 p110 患者¿突变。我们注意到细胞表面受体 RONK（Met 家族受体）的敲低会导致 H1407R突变体在应激条件下信号丢失并抑制原位转移因此，在目标 1 中，PI3K 突变体的激活与 RONK 自分泌有关的假设。活动将受到测试。对此问题的理解对于小说的开发可能很重要。独立于或补充对突变体 PI3K p110 的直接攻击的干预策略催化具体目标 II 将检验 Bax 和 pBad 的细胞生存信号传导至关重要的假设。将转移表型传递给带有这些突变的细胞的元件将被检验。通过利用 siRNA 和显性失活方法确定转移的关键生存目标在这些细胞的应激条件下共存的几种 AKT 底物相关机制之一。具体目标 III 将确定突变酶是否在仅含有野生酶的细胞中异位表达类型基因将产生类似的生存和转移机制。 PLC之间的关系?突变体 PI3K/AKT 介导的细胞存活机制假设两者都是由暴露在压力下引起的并且同时作用于压力。将测试对 Bad 的修改以启用转移。和 AKT 通过相同的竞争而联系在一起尽管如此，它们同时对细胞存活有效。在突变 PIK3CA 存在的情况下，但在野生型细胞中不存在信号传导，我们将检验以下假设：突变体 PI3K 可在低 ATP 浓度下实现更高的催化效率，从而提供足够的满足这两种途径需求的产品具体目标是： I. 确定突变型 PIK3CA 介导的转移是否需要自分泌生长因子活性。 II. 确定突变体 PIK3CA 的 Bax 降解和 Bad 磷酸化是否是必要的转移。 III. 确定不同 PIK3CA 突变对细胞存活信号和转移能力的影响。