The role of SEPT9_v1 in mammary tumorigenesis

SEPT9_v1在乳腺肿瘤发生中的作用

• 批准号: 7322269
• 负责人: Esther A Peterson
• 金额: $ 3.11万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-11-16 至 2009-11-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7322269
• 关键词: Allelic Imbalance; Aneuploidy; Apoptosis; Automobile Driving; Biological Assay; Breast; Breast Adenocarcinoma; Breast Cancer Cell; Cause of Death; Cell Cycle; Cell Cycle Regulation; Cell Polarity; Cell division; Cell physiology; Cells; Chromosome Band; Chromosome Banding; Chromosomes; Clinical Management; Complex; Cultured Cells; Cytogenetic Analysis; Cytokinesis; Diagnosis; Disease; Early Diagnosis; Energy Transfer; Epithelial Cells; Family; Fatty acid glycerol esters; Female; Filament; GTP-Binding Proteins; Genes; Genetic; Genomic Instability; Goals; Guanosine Triphosphate Phosphohydrolases; Human; Immunocompromised Host; Immunofluorescence Immunologic; Laboratory Finding; Life; Malignant - descriptor; Malignant Neoplasms; Malignant neoplasm of ovary; Mammary Tumorigenesis; Mammary gland; Maps; Membrane; Microscopy; Mitosis; Mitotic spindle; Modeling; Molecular; Mus; Mutation; Names; Oncogene Activation; Oncogenes; Orthologous Gene; Pathway interactions; Patients; Pattern; Process; Protein Overexpression; Proteins; Public Health; Research; Reverse Transcriptase Polymerase Chain Reaction; Role; SCID Mice; Sampling; Scientific Advances and Accomplishments; Spectral Karyotyping; Testing; Transcript; Tubulin; Tumor Suppressor Genes; Tumorigenicity; Western Blotting; Woman; alpha Tubulin; cellular imaging; epithelial to mesenchymal transition; functional loss; genetic risk assessment; improved; in vivo; in vivo Model; interest; leukemia; malignant breast neoplasm; malignant phenotype; mammary epithelium; member; novel; positional cloning; tumor; tumorigenesis

DESCRIPTION (provided by applicant): A novel breast cancer associated gene, SEPT9, was mapped by positional cloning to 17q25.2. SEPT9 was characterized as a member of a highly conserved family of cytokinesis genes encoding eukaryotic GTP- binding proteins named septins. The septin family has been implicated in several cellular processes including cytokinesis, membrane dynamics, cell polarity, apoptosis, cell-cycle regulation and most recently in oncogenesis. SEPT9 was found to be amplified and over-expressed in 50% of breast cancer sample available. Further analysis of SEPT9 locus demonstrated that it encodes different alternative transcripts, of which high SEPT9_v1 expression was observed in breast cancer cells by semi-quantitative RT-PCR and Western blot analysis. In addition, immortalized human mammary epithelial cells (IHMECs) over-expressing a SEPT9_v1 retroviral construct adquired malignant phenotypes, which includes an epithelial to mesenchymal transition (EMT), increased invasiveness, disrupted normal aipha-tubulin associated filaments and increased aneuploidy. Most interesting is the evidence of a direct interaction of SEPT9_v1 and alpha- tubulin, suggesting a mechanism by which overexpression of SEPT9_v1 promotes aneuploidy in IHMECs. The goal of this research is to study how increased expression of SEPT9_v1 contributes to genomic instability and to explore if the over-expression of SEPT9_v1 accelerate tumor formation and oncogenesis. To achieve this goal, SEPT9_v1 dynamic interaction with tubulin proteins during mitosis and cytokinesis will be studied using live-cell microscopy and Fluorescent Resonance Energy Transfer (FRET). In addition, the effect of SEPT9_v1 over-expression in chromosome dynamics and mitotic spindle function will be assayed by live-cell imaging and immunofluorescence. Cytogenetics analyses, including Spectral Karyotyping, will be performed to look for specific chromosomes or structural aberrations that may contribute to malignant progression in mammary epithelium when expression of SEPT9_v1 is altered. Finallly, IHMECs over- expressing SEPT9_v1 will be injected in mammary fat pads of female SCID mice to investigate SEPT9_v1's contribution to tumorigenesis and aneuploidy in an in vivo model. The goal of this project is to determine the importance of SEPT9_v1 in oncogenesis and its relevance to the early detection and clinical management of breast cancer. Breast cancer is a major public-health issue worldwide and is the second leading cause of death among women in US. To improve the genetic risk assessment, diagnosis and treatment for this common life threatening disease, the understanding of the functional role of novel potential oncogenes, such as SEPT9 v1 is essential.

描述（由申请人提供）：通过定位克隆将一种新的乳腺癌相关基因SEPT 9定位于17q25.2。SEPT 9被表征为编码称为septins的真核GTP结合蛋白的高度保守的胞质分裂基因家族的成员。Septin家族与细胞分裂、细胞膜动力学、细胞极性、细胞凋亡、细胞周期调控以及最近的肿瘤发生有关。SEPT 9被发现在50%的乳腺癌样本中扩增和过表达。对SEPT 9基因座的进一步分析表明，它编码不同的替代转录本，其中SEPT9_v1在乳腺癌细胞中的表达量较高。此外，过表达SEPT9_v1逆转录病毒构建体的永生化人乳腺上皮细胞（IHMEC）获得恶性表型，其包括上皮向间充质转化（EMT）、增加的侵袭性、破坏的正常α-微管蛋白相关丝和增加的非整倍性。最令人感兴趣的是SEPT9_v1和α-微管蛋白直接相互作用的证据，表明SEPT9_v1的过表达促进IHMEC中的非整倍性的机制。本研究的目标是研究SEPT9_v1的表达增加如何导致基因组不稳定性，并探索SEPT9_v1的过表达是否加速肿瘤形成和肿瘤发生。为了实现这一目标，将使用活细胞显微镜和荧光共振能量转移（FRET）研究有丝分裂和胞质分裂期间SEPT9_v1与微管蛋白的动态相互作用。此外，将通过活细胞成像和免疫荧光测定SEPT9_v1过表达对染色体动力学和有丝分裂纺锤体功能的影响。将进行细胞遗传学分析，包括光谱核型分析，以寻找SEPT9_v1表达改变时可能导致乳腺上皮恶性进展的特定染色体或结构畸变。最后，将过表达SEPT9_v1的IHMEC注射到雌性SCID小鼠的乳房脂肪垫中，以研究SEPT9_v1在体内模型中对肿瘤发生和非整倍性的贡献。该项目的目标是确定SEPT9_v1在肿瘤发生中的重要性及其与乳腺癌早期检测和临床管理的相关性。乳腺癌是全球范围内的一个主要公共卫生问题，也是美国女性死亡的第二大原因。为了改善这种常见的危及生命的疾病的遗传风险评估，诊断和治疗，了解新的潜在癌基因（如SEPT 9 v1）的功能作用至关重要。