Intratumoral Ploidy Dynamics in HCC

Hepatocellular carcinoma (HCC) ranks as the fourth leading cause of cancer-related deaths. Effective therapies are limited, highlighting the critical need for stratification biomarkers to improve prognosis and predict treatment response. Polyploidization or hyperploidization, an early event observed in many solid cancers, may offer such potential. Here, we developed a new high throughput in situ quantitative approach to assess HCC ploidy profiles. This novel method highlights the presence of both Diploid (DP-) and Hyperploid (HP-) HCCs. RNA-seq profiling classified hyperploid HCCs as belonging to the proliferation subclass, predicting unfavourable clinical outcomes, and revealing a gene expression signature indicative of stemness. Spatially reconstructing nuclear ploidy also revealed DP/HP-HCCs with hyperploid nuclei forming discrete clusters within a predominantly diploid background. Remarkably, these emerging hyperploid foci shared a portion of their transcriptomic programme with fully developed hyperploid HCCs and displayed a signature of genomic instability, including upregulation of multiple DNA repair pathways in response to replication-associated DNA damage. Importantly, spatial transcriptomics of DP/HP HCC demonstrated that hyperploid tumor hepatocytes arise through whole-genome doubling of diploid tumor hepatocytes. Collectively, our findings underscore the prognostic value of nuclear ploidy profiling in HCC and suggest that hyperploid HCCs evolve clonally from intratumor hyperploid foci during tumor progression.

• Type: Other
• Archiver: European Genome-phenome Archive (EGA)