Whole Chromosome Instability induces senescence and promotes SASP

Abstract

Age-related accumulation of ploidy changes is associated with decreased expression of genes controlling chromosome segregation and cohesin functions. To determine the consequences of whole chromosome instability (W-CIN) we down-regulated the spindle assembly checkpoint component BUB1 and the mitotic cohesin SMC1A, and used four-color-interphase-FISH coupled with BrdU incorporation and analyses of senescence features to reveal the fate of W-CIN cells. We observed significant correlations between levels of not-diploid cells and senescence-associated features (SAFs). W-CIN induced DNA double strand breaks and elevated oxidative stress, but caused low apoptosis. SAFs of W-CIN cells were remarkably similar to those induced by replicative senescence but occurred in only 13 days versus 4 months. Cultures enriched with not-diploid cells acquired a senescence-associated secretory phenotype (SASP) characterized by IL1B, CXCL8, CCL2, TNF, CCL27 and other pro-inflammatory factors including a novel SASP component CLEC11A. These findings suggest that W-CIN triggers premature senescence, presumably to prevent the propagation of cells with an abnormal DNA content. Cells deviating from diploidy have the ability to communicate with their microenvironment by secretion of an array of signaling factors. Our results suggest that aneuploid cells that accumulate during aging in some mammalian tissues potentially contribute to age-related pathologies and inflammation through SASP secretion.

Cellular Stress Associated with Aneuploidy

“…The cGAS-cGAMP-STING (stimulator of interferon genes) pathway (Cai et al, 2014a), the main mechanism for sensing cytoplasmic DNA, was also activated (Santaguida et al, 2017). In addition, these aneuploid cells also suffered from the DNA damage-induced proinflammatory senescence-associated secretory phenotype (SASP), which was also observed in aneuploid human primary fibroblasts (Andriani et al, 2016). These observations suggest that the aneuploid state could be proinflammatory.…”

“…In addition to increased DNA damage, aneuploid cells experiencing replication stress (including those harboring DNA damage) are also subject to several other fates, such as cell cycle delays, DNA condensation defect, inappropriate mitotic entry, senescence, and even immunological recognition and destruction (Andriani et al, 2016; Blank et al, 2015; Burrell et al, 2013; Lamm et al, 2016; Meena et al, 2015; Santaguida et al, 2017; Soto et al, 2017). Cell cycle delays associated with replication stress may be a cause of the perturbation in cell cycle/proliferative dynamics observed for aneuploid cells in the past (Segal and McCoy, 1974; Stingele et al, 2012; Williams et al, 2008).…”

Insertional oncogenesis by HPV70 revealed by multiple genomic analyses in a clinically HPV‐negative cervical cancer

“…Eight micrometer sections were cut from the diagnostic FFPE tumor block from the patient, and mounted on positively charged slides. Slides were incubated overnight at 56°C prior to FISH hybridization that was performed as previously described . Briefly, the slides were deparaffinized in Hemo‐De at room temperature for 10 min × 2, dehydrated in 100% ethanol for 5 min × 2 and placed on a 50°C slide warmer for 5 min.…”

“…The slides were then pretreated for 24 min using the Vysis Paraffin Pretreatment Reagent Kit (Abbott Molecular), and fixed in 10% buffered formalin as per the protocol. The FISH probe was labeled by nick translation using DY‐415‐aadUTP (Dyomics, Jena, GE) as previously described and hybridized overnight. The slides were then washed in 0.4X SSC prewarmed to 74°C, followed by 4X SSC/0.1% Tween.…”

CIN and Aneuploidy: Different Concepts, Different Consequences

“…[71] Furthermore, high levels of CIN are usually lethal to cells grown in vitro, [22] presumably due to the fact that single cell karyotypes evolve too fast to be selected for (also see Figure 2b). Transient high levels of CIN, however, result in proliferation defects, but are not always lethal.…”