Characterization and purification of micronuclei

“癌细胞经常表现出高水平的非整倍体和染色体不稳定性（CIN），这是有丝分裂期间染色体分离错误的结果。CIN导致细胞核内外的许多结构和数量染色体异常，后者以微核（MN）为例。微核是在有丝分裂不正常后包含完整的滞后染色体或无中心染色体片段的微型体，它们被排除在主核之外并被包裹在自己的膜中。传统上认为MN只通过这种机制产生，尽管少数研究表明它们也可以通过间期核出芽形成，并包含更小的序列，如ecDNA。它们要么持续存在，要么破裂，要么重新整合到主核中，它们的膜通常缺乏结构稳定性的关键成分，如核核层蛋白，以及核功能的关键成分，如核孔复合物。然而，关于微核中关于转录、DNA复制和DNA修复的功能障碍水平，存在着相互矛盾的观点。虽然MN最初会导致遗传物质的不平等遗传——如果它们破裂或仅由一个子细胞遗传，甚至会导致遗传物质的丢失——但它们对肿瘤的异质性、进展和转移具有重要意义，特别是在MN破裂如何通过cGAS和STING与炎症免疫反应相互作用的背景下。我们的目标是通过与Qiagen合作开发一种基于试剂盒的微核纯化方法，以确定微核类型与其特征之间的关系，从而对MN含量进行更专业的研究。该项目旨在了解微核的形成、命运和功能，首先在诱导MN和染色体不稳定细胞系的模型中，然后在肿瘤样本中更好地评估它们与肿瘤进展和预后的体内相关性，以及它们作为生物标志物的潜力。”

"Cancer cells frequently exhibit high levels of aneuploidy and chromosomal instability (CIN) as a consequence of errors in chromosome segregation during mitosis. CIN leads to a number of structural and numerical chromosome abnormalities both within and without the nucleus, the latter of which is exemplified by micronuclei (MN). Micronuclei are miniature bodies containing whole lagging chromosomes or acentric chromosome fragments which were excluded from the main nucleus and encapsulated in their own membrane after a dysfunctional mitosis. MN are traditionally thought to arise only via this mechanism, though a handful of studies have suggested they can also form through interphase nuclear budding and contain smaller sequences such as ecDNA. They may either persist, rupture, or reintegrate into the main nucleus, and their membranes often lack key components for structural stability, such as the nuclear lamin proteins, and for nuclear function, such as nuclear pore complexes. However, there are conflicting views as to the level of dysfunction present within the micronucleus regarding transcription, DNA replication, and DNA repair. While MN initially cause unequal inheritance of genetic material - and even loss of genetic material should they rupture or be inherited by only one daughter cell - they have significant implications for tumor heterogeneity, progression, and metastasis, particularly in context of how ruptured MN interact with the inflammatory immune response through cGAS and STING. We aim to enable more specialized investigation of MN contents by developing a kit-based approach to micronucleus purification, in partnership with Qiagen, to determine the relationship between the type of micronucleus and its characteristics. This project aims to understand the formation, fate, and functionality of micronuclei, first in models of induced MN and chromosomally unstable cell lines, and then in tumor samples to better assess their in vivo relevance to tumor progression and prognosis, and their potential as a biomarker."