Chromosome Instability through the Ages: Parallels between Speciation and Somatic (Cancer) Evolution

2021 ◽  
Author(s):  
Catriona MacDonald ◽  
Sarah E. McClelland
2020 ◽  
Vol 6 (50) ◽  
pp. eabc8257
Author(s):  
Nicolás Luis Calzetta ◽  
Marina Alejandra González Besteiro ◽  
Vanesa Gottifredi

Chromosome instability (CIN) underpins cancer evolution and is associated with drug resistance and poor prognosis. Understanding the mechanistic basis of CIN is thus a priority. The structure-specific endonuclease Mus81-Eme1 is known to prevent CIN. Intriguingly, however, here we show that the aberrant processing of late replication intermediates by Mus81-Eme1 is a source of CIN. Upon depletion of checkpoint kinase 1 (Chk1), Mus81-Eme1 cleaves under-replicated DNA engaged in mitotic DNA synthesis, leading to chromosome segregation defects. Supplementing cells with nucleosides allows the completion of mitotic DNA synthesis, restraining Mus81-Eme1–dependent DNA damage in mitosis and the ensuing CIN. We found no correlation between CIN arising from nucleotide shortage in mitosis and cell death, which were selectively linked to DNA damage load in mitosis and S phase, respectively. Our findings imply the possibility of optimizing Chk1-directed therapies by inducing cell death while curtailing CIN, a common side effect of chemotherapy.


2007 ◽  
Vol 3 (2) ◽  
pp. 129-137
Author(s):  
Francesco Raspagliesi ◽  
Antonino Ditto ◽  
Francesco Hanozet ◽  
Fabio Martinelli ◽  
Eugenio Solima ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Chiharu Uchida

Retinoblastoma protein (pRB) interacts with E2F and other protein factors to play a pivotal role in regulating the expression of target genes that induce cell cycle arrest, apoptosis, and differentiation. pRB controls the local promoter activity and has the ability to change the structure of nucleosomes and/or chromosomes via histone modification, epigenetic changes, chromatin remodeling, and chromosome organization. Functional inactivation of pRB perturbs these cellular events and causes dysregulated cell growth and chromosome instability, which are hallmarks of cancer cells. The role of pRB in regulation of nucleosome/chromatin structures has been shown to link to tumor suppression. This review focuses on the ability of pRB to control nucleosome/chromatin structures via physical interactions with histone modifiers and chromatin factors and describes cancer therapies based on targeting these protein factors.


Author(s):  
Stacey J. Scott ◽  
Xiaodun Li ◽  
Sriganesh Jammula ◽  
Ginny Devonshire ◽  
Catherine Lindon ◽  
...  

AbstractPolyploidy is present in many cancer types and is increasingly recognized as an important factor in promoting chromosomal instability, genome evolution, and heterogeneity in cancer cells. However, the mechanisms that trigger polyploidy in cancer cells are largely unknown. In this study, we investigated the origin of polyploidy in esophageal adenocarcinoma (EAC), a highly heterogenous cancer, using a combination of genomics and cell biology approaches in EAC cell lines, organoids, and tumors. We found the EAC cells and organoids present specific mitotic defects consistent with problems in the attachment of chromosomes to the microtubules of the mitotic spindle. Time-lapse analyses confirmed that EAC cells have problems in congressing and aligning their chromosomes, which can ultimately culminate in mitotic slippage and polyploidy. Furthermore, whole-genome sequencing, RNA-seq, and quantitative immunofluorescence analyses revealed alterations in the copy number, expression, and cellular distribution of several proteins known to be involved in the mechanics and regulation of chromosome dynamics during mitosis. Together, these results provide evidence that an imbalance in the amount of proteins implicated in the attachment of chromosomes to spindle microtubules is the molecular mechanism underlying mitotic slippage in EAC. Our findings that the likely origin of polyploidy in EAC is mitotic failure caused by problems in chromosomal attachments not only improves our understanding of cancer evolution and diversification, but may also aid in the classification and treatment of EAC and possibly other highly heterogeneous cancers.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1256
Author(s):  
Ivan Y. Iourov ◽  
Yuri B. Yurov ◽  
Svetlana G. Vorsanova ◽  
Sergei I. Kutsev

Chromosome instability (CIN) has been repeatedly associated with aging and progeroid phenotypes. Moreover, brain-specific CIN seems to be an important element of pathogenic cascades leading to neurodegeneration in late adulthood. Alternatively, CIN and aneuploidy (chromosomal loss/gain) syndromes exhibit accelerated aging phenotypes. Molecularly, cellular senescence, which seems to be mediated by CIN and aneuploidy, is likely to contribute to brain aging in health and disease. However, there is no consensus about the occurrence of CIN in the aging brain. As a result, the role of CIN/somatic aneuploidy in normal and pathological brain aging is a matter of debate. Still, taking into account the effects of CIN on cellular homeostasis, the possibility of involvement in brain aging is highly likely. More importantly, the CIN contribution to neuronal cell death may be responsible for neurodegeneration and the aging-related deterioration of the brain. The loss of CIN-affected neurons probably underlies the contradiction between reports addressing ontogenetic changes of karyotypes within the aged brain. In future studies, the combination of single-cell visualization and whole-genome techniques with systems biology methods would certainly define the intrinsic role of CIN in the aging of the normal and diseased brain.


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