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.

抽象的我们已经确定了一组具有PIK3CA功能突变增益的结肠癌细胞系，并具有表明它们与来自原位原发性结肠肿瘤的细胞存活和转移密切相关肝脏和肺。最近已显示这些突变可以预测结直肠和乳腺癌。这种竞争续约应用的目标是表征突变体的基础 PI3K对生存和恶性进展的贡献，并确定上游和有助于生存和转移定殖的突变体的下游。这种调查是有望导致确定将适当的靶向剂与该子组相匹配的策略结直肠癌患者具有这些突变，并允许进一步细化患者亚组来自p110 p110突变的患者。我们已经指出，在细胞表面受体ronk（MET家族受体）的敲低中导致 H1407R突变体在应力条件下失去信号传导，并抑制正位的转移结肠癌模型。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进行测试。对这个问题的理解对于新颖的发展至关重要干预的策略与突变体PI3K P110的直接攻击无关或完成亚基。特定的目标II将检验以下假设，即通过Bax和Pbad的细胞存活信号传导是关键将转移表型传递给具有这些突变的细胞的元素。该假设将进行检验通过使用siRNA和主要的负面方法来确定从在这些细胞中应力条件下共存的几种AKT底物相关机制中。特定的目标III将确定仅野生的细胞中突变酶异位表达是否类型基因将产生类似的生存和转移机制。我们还将表征 PLC。细胞存活与突变体PI3K/AKT的关系之间的关系路径。假设两者都是通过暴露于压力并同时行动的假设将测试对不良转移的不良转移的修改。 plc¿和Akt与竞争相同的竞争联系在一起底物，通常彼此抑制。尽管如此，它们对于细胞存活而言只是有效的在存在突变体PIK3CA的存在下，但在野生型细胞中发出信号传导。我们将检验以下假设突变PI3K允许在低ATP浓度下提高催化效率，而ATP浓度又提供了足够的催化效率产品以满足这两种途径的需求。具体目的是： I.确定突变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是否需要Bax降解和不良磷酸化。转移。 iii。确定不同PIK3CA突变对细胞存活信号传导和转移能力的影响。