Nuclear Dysfunction in Cancer: The Role of Mechanical Stresses Transmittedby the LINC Complex

项目摘要 核纤层通过LINC通过核膜蛋白与细胞骨架物理连接 复合体（核骨架与细胞骨架的连接体），跨越核被膜并允许 将机械力传递到细胞核。LINC复合体蛋白经常发生突变或失调 在癌症中，其中一些突变被认为是癌症的驱动因素。然而，如何改变 LINC复合物可能促进癌症发展尚不清楚。这个应用程序的首要假设 由于LINC蛋白的驱动突变， 导致上皮极性丧失、异常组织结构、异常基因表达、转化和 侵袭性癌细胞迁移。提出了以下目标：目标1。定义对LINC复合体的更改- 在癌症中传递机械应力。LINC复合体如何将机械力传递到位置 将确定正常乳腺上皮细胞中的细胞核和整合张力。分子和物理 将确定浸润性乳腺上皮癌3-D迁移中细胞核定位的机制。目标二。 确定LINC复合体如何有助于改变基因组的表观遗传组织 在乳腺癌的发展过程中LINC破坏影响基因空间分配的程度 在细胞核和异染色质组织将被确定;这些影响将与细胞 表型、基因表达和表观基因组谱。完整的LINC复合体的要求， 将检查向恶性转化。癌细胞核的研究仍然非常不足， 了解有关核定位，畸形和染色质的物理原理 组织，以及改变的核压力如何导致癌细胞功能障碍。这两个目标的重点是 研究LINC复合体传递的细胞骨架应力对基因表达和细胞功能的影响。 这必然需要对分子和物理机制的综合理解。广泛 在其他系统中获得的专门知识将与测量原子核作用力的新方法相结合。 这些包括直接的力探针，以询问扩散，活细胞和细胞核中的机械反应。 核张力传感器，用于研究癌细胞和正常细胞中的核力。基于物理 将使用计算模型来解释所得到的数据。将采用物理方法 描述癌细胞核的特征，并生成独特的基因组范围的基因表达数据集， 在实验性地改变LINC复合体连接以发现LINC复合体在乳腺癌中的作用后， 癌症发病机制

PROJECT ABSTRACT The nuclear lamina is physically connected through nuclear envelope proteins to the cytoskeleton by the LINC complex (linker of nucleoskeleton to cytoskeleton), which spans the nuclear envelope and allows the transmission of mechanical forces to the nucleus. LINC complex proteins are frequently mutated or dysregulated in cancer, and some of these mutations have been proposed to be cancer drivers. Yet, how alterations to the LINC complex might promote cancer development is not known. This application's overarching hypothesis is that cytoskeletal force transmission to the nucleus is altered in cancer due to driver mutations in LINC proteins contributing to loss of epithelial polarity, aberrant tissue structure, abnormal gene expression, transformation and invasive cancer cell migration. The following aims are proposed: Aim 1. Define alterations to LINC complex- transmitted mechanical stresses in cancer. How the LINC complex transmits mechanical forces to position the nucleus and integrates tension in normal breast epithelia will be determined. The molecular and physical mechanisms for nuclear positioning in invasive breast epithelial cancer 3-D migration will be determined. Aim 2. Determine how the LINC complex contributes to altering the epigenetic organization of the genome during progression to breast cancer. The extent to which LINC disruption affects spatial partitioning of genes in the nucleus and heterochromatin organization will be identified; these effects will be correlated with cell phenotype, gene expression and epigenomic profiles. The requirement for an intact LINC complex for transformation to malignancy will be examined. The cancer nucleus remains highly understudied, with much to learn known about the physical principles that govern nuclear positioning, dysmorphia and chromatin organization, and how altered nuclear stresses contribute to cancer cell dysfunction. The focus of both aims is on the impact of cytoskeletal stresses transmitted by the LINC complex on gene expression and cell function. This necessarily requires an integrated understanding of both molecular and physical mechanisms. Extensive expertise gained in other systems will be coupled with new approaches for measuring forces on the nucleus. These include a direct force probe to interrogate nuclear mechanical responses in spread, living cells and nuclear tension sensors for the study of nuclear forces in both cancer and normal cells. Physically-based computational models will be used to interpret the resulting data. A physical approach will be applied to characterize the cancer nucleus and generate unique, genome-wide data sets for gene expression after experimentally altering LINC complex connections to discover the role of the LINC complex in breast cancer pathogenesis.