Molecular Basis and Role of Indirect Chromosome Segregation in Hyperploid Cancer Cells

超倍体癌细胞中间接染色体分离的分子基础和作用

• 批准号: 9123332
• 负责人: Christina Lynn Hueschen
• 金额: $ 3.55万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9123332
• 关键词: Ablation; Adaptor Signaling Protein; Adenocarcinoma Cell; Adverse effects; Anaphase; Aneuploid Cells; Aneuploidy; Architecture; Binding; Breast; Breast Adenocarcinoma; Breast Cancer Cell; Cancer Etiology; Cell Death; Cell Line; Cell Survival; Cell physiology; Cells; Cellular biology; Chemotherapy-Oncologic Procedure; Chromosomal Instability; Chromosome Segregation; Chromosomes; Complex; Confocal Microscopy; Crowding; DNA; Development; Diploid Cells; Diploidy; Dynein ATPase; Etiology; Fiber; Goals; Health; Human; Image; Immunofluorescence Immunologic; Investigation; Kinetics; Laboratories; Lasers; Length; Malignant Neoplasms; Mammary gland; Measures; Mechanics; Mediating; Microscopy; Microtubule Bundle; Microtubules; Minus End of the Microtubule; Mitosis; Mitotic spindle; Modeling; Molecular; Molecular Target; Motor; Mutation; Oncogenic; Paclitaxel; Patients; Play; Ploidies; Quality of life; Recruitment Activity; Resolution; Role; Staining method; Stains; Testing; Therapeutic; Time; Walking; Work; base; cancer cell; cellular imaging; daughter cell; dynactin; genetic information; killings; new therapeutic target; novel; novel therapeutics; preference; segregation; targeted cancer therapy; therapy development; tool; tumor

 DESCRIPTION (provided by applicant): Hyperploidy (cells with abnormally high numbers of chromosomes) is observed in most human cancers and has been recognized as a hallmark of cancer cells for over a century. The association between hyperploidy and cancer is clear, and provides a clear therapeutic opportunity. If we can identify cellular processes strained or altered by hyperploidy, we can in principle develop therapies that specifically target hyperploid tumors. Currently, standard cancer chemotherapy agents such as taxol (paclitaxel) indiscriminately target dividing cells, causing myriad side effects that limit their efficacy and reduce patient quality of life. New cancer chemotherapies are needed, with greater selectivity for cancer cells. To perform its function, the mitotic spindle of a hyperploid cancer cell must align and segregate as many as four times the normal number of chromosomes. Hyperploid spindles are crowded with extra chromosomes and extra k-fibers (the bundles of microtubules that hold on to chromosomes), resulting in altered spindle architecture. Interestingly, not all k-fibers in hyperploid human cancer cells are directly connected to the spindle pole (Sikirzhytski* and Magidson* et al., 2014). Our laboratory recently discovered that chromosomes that lack a direct connection to the spindle pole can still undergo segregation via an alternative - now indirect - transport mechanism, mediated by the dynein-dynactin motor complex and the dynein adaptor protein NuMA (Elting* and Hueschen* et al., 2014). Here, we propose to investigate this newly- uncovered alternative mechanism of chromosome segregation and the role it plays in hyperploid cancer cells. We hypothesize that hyperploid cancer cells are preferentially dependent on this indirect chromosome segregation mechanism, and propose to investigate its underlying cellular biology with the goal of uncovering novel therapeutic targets and strategies. Specifically, we aim to identify the molecular mechanism of indirect chromosomes segregation and to determine if hyperploid cancer cells are preferentially dependent on indirect chromosome segregation for survival. Our strategy combines: spindle laser ablation as a tool to create indirect chromosome-to-pole connections, molecular perturbations and readouts, and high resolution microscopy of both non-transformed diploid cells and breast cancer cells of different ploidy. We expect that our investigation of the molecular mechanism of indirect chromosome segregation will reveal novel targets for cancer therapy. Moreover, we expect that uncovering the role of indirect segregation in hyperploid cell function will determine the potential for selective hyperploid cell death by indirect segregation inhibition, alone or in combination with existing cancer chemotherapies. In the long term, this work may contribute to the development of novel and selective cancer chemotherapies.

 描述（由申请人提供）：在大多数人类癌症中观察到超倍性（具有异常高数目染色体的细胞），并且已被认为是癌细胞的标志超过世纪。超倍性和癌症之间的关联是明确的，并提供了明确的治疗机会。如果我们能识别出细胞过程的紧张或改变 通过超倍性，我们原则上可以开发出特异性靶向超倍体肿瘤的疗法。目前，标准的癌症化疗药物，如紫杉醇（紫杉醇）不加选择地靶向分裂细胞，导致无数的副作用，限制了它们的疗效，降低了患者的生活质量。需要新的癌症化疗方法，对癌细胞具有更大的选择性。为了发挥其功能，超倍体癌细胞的有丝分裂纺锤体必须排列和分离多达四倍于正常数量的染色体。超倍体纺锤体中充满了额外的染色体和额外的k-纤维（固定染色体的微管束），导致纺锤体结构的改变。有趣的是，并非超倍体人癌细胞中的所有k-纤维都直接连接到纺锤体极（Sikirzhytski* 和Magidson* 等人，2014年）。我们的实验室最近发现，缺乏与纺锤体极的直接连接的染色体仍然可以通过替代的-现在是间接的-运输机制进行分离，该机制由动力蛋白-动力蛋白马达复合物和动力蛋白衔接蛋白NuMA介导（Elting* 和Hueschen* 等人，2014年）。在这里，我们建议调查这一新发现的染色体分离的替代机制及其在超倍体癌细胞中所起的作用。我们假设超倍体癌细胞优先依赖于这种间接的染色体分离机制，并建议研究其潜在的细胞生物学，目的是发现新的治疗靶点和策略。具体而言，我们的目标是确定间接染色体分离的分子机制，并确定超倍体癌细胞是否优先依赖于间接染色体分离生存。我们的战略包括：纺锤体激光消融作为一种工具，以建立间接的染色体到极点的连接，分子扰动和读出，以及高分辨率显微镜的非转化二倍体细胞和乳腺癌细胞的不同倍性。我们希望我们对间接染色体分离的分子机制的研究将揭示癌症治疗的新靶点。此外，我们预计，揭示间接分离在超倍体细胞功能中的作用将确定通过间接分离抑制（单独或与现有癌症化疗联合）进行选择性超倍体细胞死亡的可能性。从长远来看，这项工作可能有助于开发新的和选择性的癌症化疗。