DNA Damage Follows Repair Factor Depletion and Portends Genome Variation in Cancer Cells after Pore Migration.
DNA Damage Follows Repair Factor Depletion and Portends Genome Variation in Cancer Cells after Pore Migration.
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DNA损伤遵循修复因子耗竭，并预测孔迁移后癌细胞的基因组变异。
DOI：
10.1016/j.cub.2016.11.049
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发表时间：
2017-01-23
期刊：
影响因子：
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通讯作者：
Discher DE
中科院分区：
文献类型：
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作者：
Irianto J;Xia Y;Pfeifer CR;Athirasala A;Ji J;Alvey C;Tewari M;Bennett RR;Harding SM;Liu AJ;Greenberg RA;Discher DE
人们发现，通过微米大小的收缩的迁移会破裂细胞核，释放核定位的 GFP，并导致异位 53BP1（一种 DNA 修复蛋白）的局部积累。在这里，通过内源性损伤标记物和电泳“彗星”测量评估，两种人类癌细胞类型和原代间充质干细胞 (MSC) 的收缩迁移增加了整个核质中的 DNA 断裂。迁移还会导致多种 DNA 修复蛋白与 DNA 分离，细胞质错误定位持续数小时，这与修复延迟有关。部分敲除也调节染色体拷贝数的修复因子会增加 U2OS 骨肉瘤细胞中的 DNA 断裂，而不影响迁移，并且具有类似于收缩迁移的核质损伤模式。这种消耗也会导致 DNA 水平异常。尽管如此，对于野生型和亚克隆 U2OS 细胞来说，迁移引起的核损伤是可逆的，除了 DNA 阵列和测序揭示的稳定克隆之间存在持久的基因组差异之外。许多染色体中数百个兆碱基的增加和丢失是骨癌的典型变化和异质性。 U2OS 克隆的收缩迁移引起的表型差异通过具有高度伸长且稳定的 MSC 样形状的克隆进一步说明，该形状依赖于转录因子 GATA4 下游的微管组装。这种变化与癌性成骨细胞上游恢复到更像干细胞的状态是一致的。因此，迁移引起的基因组不稳定性可能与遗传变化相关。
Migration through micron-size constrictions has been seen to rupture the nucleus, release nuclear-localized GFP, and cause localized accumulations of ectopic 53BP1 – a DNA repair protein. Here, constricted migration of two human cancer cell types and primary mesenchymal stem cells (MSC) increases DNA breaks throughout the nucleoplasm as assessed by endogenous damage markers and by electrophoretic ‘comet’ measurements. Migration also causes multiple DNA repair proteins to segregate away from DNA, with cytoplasmic mis-localization sustained for many hours as is relevant to delayed repair. Partial knockdown of repair factors that also regulate chromosome copy numbers is seen to increase DNA breaks in U2OS osteosarcoma cells without affecting migration and with nucleoplasmic patterns of damage similar to constricted migration. Such depletion also causes aberrant levels of DNA. Migration-induced nuclear damage is nonetheless reversible for wild-type and sub-cloned U2OS cells, except for lasting genomic differences between stable clones as revealed by DNA arrays and sequencing. Gains and losses of hundreds of megabases in many chromosomes are typical of the changes and heterogeneity in bone cancer. Phenotypic differences that arise from constricted migration of U2OS clones are further illustrated by a clone with a highly elongated and stable MSC-like shape that depends on microtubule assembly downstream of the transcription factor GATA4. Such changes are consistent with reversion to a more stem-like state upstream of cancerous osteoblastic cells. Migration-induced genomic instability can thus associate with heritable changes.