The role of SEPT9 in cell proliferation and oncogenesis

SEPT9在细胞增殖和肿瘤发生中的作用

基本信息

批准号：
7330309
负责人：
ELIZABETH M. PETTY
金额：
$ 29.6万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
1997
资助国家：
美国
起止时间：
1997-09-08 至 2010-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7330309
关键词：
Abnormal Cell Agar Allelic Imbalance Anchorage-Independent Growth Aneuploidy Animals Apoptosis Apoptotic Breast Breast Adenocarcinoma Breast Cancer Cell Cell Cycle Cell Cycle Progression Cell Cycle Regulation Cell Nucleus Cell Proliferation Cell division Cells Cellular Morphology Characteristics Chromosome Band Chromosome Banding Clinical Clinical Management Colon Carcinoma Condition Contact Inhibition Coupled Cytokinesis Data Depth Development Ectopic Expression Epithelial Cells Exons Family GTP Binding Genetic Genome Stability Genomic Instability Giant Cells Gland Goals Growth Homologous Gene Human Image Immunocompromised Host In Vitro Kinetics Lead Life Literature Localized Malignant - descriptor Malignant Neoplasms Malignant neoplasm of ovary Mammalian Cell Mammary Neoplasms Mammary Tumorigenesis Mammary gland Microfilaments Modeling Molecular Morphology Mouse Mammary Tumor Virus Mus Mutagenesis Names Nuclear Nutrient Oncogenes Oncogenic Orthologous Gene Outcome Pathway interactions Patients Pattern Phenotype Play Ploidies Protein Family Protein Isoforms Protein Overexpression Proteins Proto-Oncogenes RNA Splicing Rate Regulation Research Personnel Role S-Phase Fraction SCID Mice Sampling Studies Small Interfering RNA Somatic Cell T-Cell Lymphoma T-Lymphocyte Testing Tetanus Helper Peptide Therapeutic Time Tissues Transcript Transgenes Transgenic Model Transgenic Organisms Tumorigenicity Variant Yeasts alpha Tubulin cancer cell carcinogenesis clinically significant immunocytochemistry in vitro Model in vivo innovation insight intracellular protein transport leukemia malignant breast neoplasm malignant phenotype member mouse model novel ovarian neoplasm pro-apoptotic protein prognostic programs promoter protein localization location tumor tumorigenesis

项目摘要

A classic feature of carcinogenesis is aberrant cell cycle regulation but little is known about how abnormal cell division contributes to malignant progression. Human SEPT9 belongs toa highly conserved eukaryotic family of GTP binding septin proteins importantin cell division. In yeast, septins are coupled to cell cycle progression and are critical for normal morphology. Mammalian SEPT9 is requiredfor normal somatic cell division. SEPT9 is highly homologous to Sept9/Sint1,a murineproto-oncogeneinvolvedin T-cell lymphomasthat is overexpressed in murine models of mammary adenocarcinomas. We originally cloned SEPT9 from a region of allelic imbalance in breast cancers and have subsequently demonstrated SEPT9 amplification in breast cancer cells. We have also observed preferential expression of an alternatively spliced variant, SEPT9v1, in breast cancer cells. Stable ectopic expression of SEPT9v1 studied to date in in vitro models resulted in increased growth kinetics, altered cell morphology, increasedfoci formation, increased invasiveness,abnormal cell division, nuclear mis-localization of the protein, and aneuploidy. SEPT9 was also identified as an MIL fusion partner in leukemia cells. Taken together, findings of: (1) an essential role for SEPT9 in cell division; (2) SEPT9 amplification and preferential expression of SEPT9v1 in breast cancer cells; (3) an altered cell phenotype with increased proliferation, invasiveness, foci formation, and aneuploidy when SEPT9v1variant is ectopically expressed; and (4) homology to an oncogenic murine ortholog overexpressedin breast cancer provide compelling support for our hypothesis that increased expression of SEPT9v1, and possibly additional SEPT9 variants, is associated with abnormal cell division and malignant progression in mammary epithelial cells. To test this hypothesis we will: (1) determine if cellular levels of SEPT9v 1 in an archival panel of well-characterized primary and metastatic mammary tumors correlate with poor prognostic clinicopathological variables clinical outcome; (2) analyze in vitro epithelial cell culture and in vivo tumorigenicity models to determine how increased SEPT9v1impacts cell proliferation, growth characteristics, invasiveness, apoptosis, cell morphology, and genomic stability as related to malignant progression; and (3) evaluate how in vivo overexpression of SEPT9v1 impacts normal mammary gland development and malignant potential by constructing and analyzing tissue specific and conditional transgenic mouse models, including crosses to other transgenicmurine modelsof breastcancer. Resultswill provide insights into how increased SEPT9 v1 expression impacts cell division and tumorigenesis in mammary epithelial cells, which may have significant prognostic and/or therapeutic implications.

癌发生的一个典型特征是异常的细胞周期调节，但人们对异常程度知之甚少。细胞分裂有助于恶性进展。人类SEPT9属于高度保守的真核家族 GTP 结合 septin 蛋白对细胞分裂很重要。在酵母中，septin 与细胞周期进程相关，并且对于正常形态至关重要。哺乳动物 SEPT9 是正常体细胞分裂所必需的。 SEPT9 非常与 Sept9/Sint1 同源，Sept9/Sint1 是一种与 T 细胞淋巴瘤有关的鼠原癌基因，在鼠中过度表达乳腺癌模型。我们最初从乳房等位基因不平衡的区域克隆了 SEPT9 癌症，随后在乳腺癌细胞中证明了 SEPT9 扩增。我们还有观察到选择性剪接变体 SEPT9v1 在乳腺癌细胞中优先表达。稳定的迄今为止在体外模型中研究的 SEPT9v1 异位表达导致生长动力学增加，改变细胞形态、病灶形成增加、侵袭性增加、细胞分裂异常、核错误定位蛋白质和非整倍体。 SEPT9 还被鉴定为白血病细胞中的 MIL 融合伴侣。采取总之，研究结果如下：(1) SEPT9 在细胞分裂中的重要作用； (2) SEPT9扩增及优惠 SEPT9v1在乳腺癌细胞中的表达； (3) 细胞表型改变，增殖增加， SEPT9v1 变体异位表达时的侵袭性、病灶形成和非整倍性； (4)同源性乳腺癌中过度表达的致癌小鼠直系同源物为我们的假设提供了令人信服的支持 SEPT9v1 以及可能的其他 SEPT9 变体的表达增加与异常细胞相关乳腺上皮细胞的分裂和恶性进展。为了检验这个假设，我们将：（1）确定是否一组已明确表征的原发性和转移性乳腺肿瘤中 SEPT9v 1 的细胞水平与不良预后临床病理变量、临床结果相关； (2) 体外上皮细胞分析培养和体内致瘤性模型，以确定 SEPT9v1 增加如何影响细胞增殖和生长与恶性相关的特征、侵袭性、凋亡、细胞形态和基因组稳定性进展； (3) 评估 SEPT9v1 的体内过度表达如何影响正常乳腺通过构建和分析组织特异性和条件转基因来确定发育和恶性潜力小鼠模型，包括与其他乳腺癌转基因小鼠模型的杂交。结果将提供见解研究 SEPT9 v1 表达增加如何影响乳腺上皮细胞的细胞分裂和肿瘤发生，这可能具有显着的预后和/或治疗意义。