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(CIN)，这是有丝分裂过程中染色体分离错误的结果。CIN在核内和核外都会导致许多染色体结构和数目的异常，后者以微核(MN)为代表。微核是指含有完整的滞后染色体或无着丝粒染色体片段的微小体，这些染色体片段在功能失调的有丝分裂后被排除在主核之外，并被包裹在自己的膜中。传统上认为，锰只能通过这种机制产生，尽管少数研究表明，它们也可以通过间期核萌发形成，并含有较小的序列，如ecDNA。它们可能会持续、破裂或重新整合到主核中，它们的膜往往缺乏结构稳定的关键成分，如核层粘连蛋白，以及核功能的关键成分，如核孔复合体。然而，对于微核内存在的转录、DNA复制和DNA修复功能障碍的程度，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，甚至遗传物质的损失--但它们对肿瘤的异质性、进展和转移有重要影响，特别是在破裂的MN如何通过cGAS和STIN与炎性免疫反应相互作用的背景下。我们的目标是通过与Qigen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，从而实现对MN含量的更专门的调查。该项目旨在了解微核的形成、命运和功能，首先是在诱导的MN和染色体不稳定细胞系的模型中，然后是在肿瘤样本中，以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记物的潜力。

"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."