The question of whether CIN drives cells into a highly aneuploid state remained unanswered prior to this study, despite observations that persistent chromosome missegregation is presumed to cause high aneuploidaneuploidy levels in tumor cells. This study addresses the bidirectional relationship between CIN and aneuploidy by examining whether elevated missegregation rates can generate aneuploid cells. [@thompson_examining_2008]
Definitions
Synthesis
The relationship between chromosomal instability (CIN) and aneuploidy has long been recognized through their correlation in tumor cells, yet whether CIN directly causes aneuploidy or merely accompanies it remained mechanistically unclear. While classic mitotic defects like impaired bipolar spindle assembly and spindle assembly checkpoint dysfunction can explain CIN in only a small subset of aneuploid tumor cells, the underlying mechanisms driving CIN in most chromosomally unstable cells were previously undetermined. Experimental evidence has established that specific defects such as merotely and reduced CENP-E levels can induce both chromosome missegregation and aneuploidy, yet chromosome missegregation alone proves insufficient for generating viable aneuploid cell populations without additional phenotypic adaptations. This gap between observing elevated missegregation rates and achieving sustained aneuploid cell propagation highlights the unresolved question of how CIN causally contributes to aneuploidy beyond simply increasing the frequency of chromosome segregation errors.
Related
- Stat1 inactivation mechanism is conserved between mouse and human aneuploid cancers
- Mps1 truncation-induced CIN generates convergent recurrent chromosome gains
- Merotely causes chromosome missegregation in unstable cells
- Multipolar divisions are rare and typically produce inviable progeny
- Aneuploidy increases spontaneous tumor formation in aged animals
- Increased aneuploidy inhibits chemically and genetically induced tumorigenesis
- Aneuploid tumors inactivate Stat1 signaling with increased Myc activity
- Extra centrosomes correlate with chromosomal instability in tumors
- Stat1 loss combined with Myc activation alleviates CIN-induced immune infiltration
- CIN exists independently of classic mitotic defects in most cells
- Single-cell sequencing reveals karyotype heterogeneity in lymphomas
- Aneuploidy exhibits dual roles as oncogenic and tumor-suppressive
- Elevated merotely generates CIN in stable near-diploid cells
- CENP-E reduction generates aneuploidy and chromosomal instability
- Missegregation alone insufficient for aneuploid cell propagation