Abstract
Whole genome doubling (WGD) is a frequent event in cancer evolution associated with chromosomal instability, metastasis, and poor prognosis. Whereas the genomic consequences of WGD are well documented, nongenetic alterations that accompany WGD, such as changes to cell and nuclear size, may also play an important role in tetraploid (4N) cancer cell physiology. In this study, we showed that cell and nuclear volume does not always scale with DNA content after WGD in cancer cells, resulting in 4N cells that differ in size. Small size was associated with enhanced cell fitness, mitotic fidelity, and tumorigenicity in 4N cancer cells and with poor patient survival in WGD-positive human cancers. Overall, these results suggest that cell and nuclear size may contribute to the tumorigenic potential of 4N cancer cells and could be an important prognostic marker in human tumors that undergo WGD. SIGNIFICANCE: Cancer cell size varies after whole genome duplication, with smaller cells exhibiting high tumorigenicity and correlating with poor patient survival, demonstrating the clinical relevance and highlighting the biomarker potential of cell size.