A PTEN-Dependent Size Checkpoint in Human Cancer Cells

人类癌细胞中 PTEN 依赖性大小检查点

基本信息

批准号：
7417921
负责人：
TODD A WALDMAN
金额：
$ 24.07万
依托单位：
GEORGETOWN UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-05-11 至 2011-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7417921
关键词：
Affect Attenuated Binding Biochemical Biological Models Cancer cell line Cell Line Cell Size Cells Characteristics DNA Damage Data Drosophila melanogaster G2 Checkpoint control GTP-Binding Proteins Gene Targeting Genes Goals Guanosine Triphosphate Phosphohydrolases HCT116 Cells House mice Human Knock-out Knowledge Lead Malignant Neoplasms Measures Mutation Normal Cell Numbers Oncogenes Oncogenic Organism Oxidative Stress PIK3CA gene PTEN gene Pathway interactions Phenotype Phosphorylation Phosphotransferases Poison Property Radiation Radiation, Other Range Reporting Research Personnel Signal Transduction Signal Transduction Pathway Small Interfering RNA Somatic Cell Stimulus System TP53 Gene Inactivation TP53 gene TSC2 gene Testing Transfection Tumor Suppressor Genes Tumor Suppressor Proteins Variant Work cancer cell human PIK3CA protein novel programs response size small hairpin RNA

项目摘要

DESCRIPTION (provided by applicant): Activation of PIP3 signaling by inactivating mutations in the PTEN tumor suppressor or activating mutations in the PIK3CA oncogene is found in a wide range of common human cancers. Though the biochemical details of PIP3 signal transduction are rapidly emerging, the phenotypic consequences of PIP3 pathway activation in human cancer cells remain less well defined. As such, the long-term goal of this project is to define the effects of PIP3 activation in human cancer cells. In our initial preliminary studies, we employed human somatic cell gene targeting to create isogenic sets of PTEN+/+ and PTEN-/- human cancer cell lines. Using these and related model systems, we found that PTEN controls a novel radiation-induced size checkpoint in human cells that is distinct and genetically separable from the radiation-induced, p53-dependent G1 and G2 checkpoints. To our knowledge, the existence of such a DNA damage-inducible size arrest has neither been postulated or demonstrated in any organism. Since the initial submission of this application we have employed human somatic cell gene targeting to create an isogenic set of PIK3CA gene targeted human cancer cells, and also created NIH3T3 cell lines that express wild-type, oncogenic, or inactive forms of PIK3CA. Using these systems we have obtained preliminary data suggesting that, like PTEN, the PIK3CA oncogene may be able to regulate size checkpoint function as well. In this application we propose three related specific aims to further pursue and extend these observations. Aim #1 - Identify additional inducers of the PTEN-dependent size checkpoint. Aim #2 - Demonstrate the presence of the PTEN-dependent size checkpoint in untransformed human cells. Aim #3 - Characterize crosstalk between the radiation-induced, p53-dependent G1/G2 checkpoints and the radiation-induced, PTEN-dependent cell size checkpoint. Pursuit of these aims will enable us to further characterize the properties and mechanism(s) of a tumor suppressor gene-regulated, radiation-induced cell size checkpoint.

描述（由申请人提供）：通过在PTEN肿瘤抑制器中灭活突变或PIK3CA癌基因中激活突变激活PIP3信号传导，在广泛的常见人类癌症中发现。尽管PIP3信号转导的生化细节正在迅速出现，但人类癌细胞中PIP3途径激活的表型后果仍然不太明确。因此，该项目的长期目标是定义PIP3激活在人类癌细胞中的影响。在最初的初步研究中，我们采用了人类的体细胞基因靶向靶向PTEN+/+和PTEN - / - 人类癌细胞系的等源性集。使用这些和相关的模型系统，我们发现PTEN控制着人类细胞中新型辐射诱导的大小检查点，该检查点与辐射诱导的p53依赖性G1和G2检查点不同，并且在遗传上可分开。据我们所知，在任何生物体中均未假定或证明这种DNA损伤诱导的大小骤停的存在。自本应用的最初提交以来，我们已经采用了人类体细胞基因靶向靶向人类的PIK3CA基因靶向人类癌细胞，还创建了表达野生型，致癌性或无效形式的PIK3CA的NIH3T3细胞系。使用这些系统，我们获得了初步数据，表明像PTEN一样，PIK3CA Oncogene也可以调节大小检查点功能。在本应用程序中，我们提出了三个相关的特定目的，以进一步追求和扩展这些观察结果。 AIM＃1-确定与PTEN依赖性尺寸检查点的其他诱导者。 AIM＃2-证明未转化的人类细胞中PTEN依赖性尺寸检查点的存在。 AIM＃3-表征辐射诱导的P53依赖性G1/G2检查点与辐射诱导的PTEN依赖性细胞大小检查点之间的串扰。对这些目标的追求将使我们能够进一步表征肿瘤抑制基因调节的，辐射诱导的细胞大小检查点的特性和机制。