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 SEPT9 定位到 17q25.2。 SEPT9 是高度保守的胞质分裂基因家族的成员，编码名为 septins 的真核 GTP 结合蛋白。 septin 家族与多种细胞过程有关，包括胞质分裂、膜动力学、细胞极性、细胞凋亡、细胞周期调节以及最近的肿瘤发生。发现 SEPT9 在 50% 的乳腺癌样本中被扩增并过度表达。对SEPT9位点的进一步分析表明，它编码不同的替代转录本，通过半定量RT-PCR和Western blot分析，在乳腺癌细胞中观察到其中SEPT9_v1的高表达。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) 获得了恶性表型，包括上皮间质转化 (EMT)、侵袭性增加、正常 aipha-微管蛋白相关丝被破坏和非整倍性增加。最有趣的是 SEPT9_v1 和 α-微管蛋白直接相互作用的证据，表明 SEPT9_v1 过度表达促进 IHMEC 中非整倍性的机制。本研究的目的是研究 SEPT9_v1 表达的增加如何导致基因组不稳定，并探讨 SEPT9_v1 的过度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 SEPT9_v1 在有丝分裂和胞质分裂过程中与微管蛋白的动态相互作用。此外，还将通过活细胞成像和免疫荧光来检测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，以寻找当 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小鼠的乳腺脂肪垫中，以在体内模型中研究SEPT9_v1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。乳腺癌是世界范围内的一个重大公共卫生问题，也是美国女性第二大死因。为了改善这种常见危及生命疾病的遗传风险评估、诊断和治疗，了解新的潜在癌基因（例如 SEPT9 v1）的功能作用至关重要。