Dynamics of genomic, epigenomic, and transcriptomic aberrations during stepwise hepatocarcinogenesis
Menée à partir de 302 échantillons de tissu hépatique prélevés sur 166 patients présentant une cirrhose hépatique, un nodule dysplasique de bas ou haut grade, un carcinome hépatocellulaire de stade précoce ou de stade plus avancé, cette étude analyse l'évolution des aberrations génomiques, épigénomiques et transcriptomiques durant les différentes étapes de l'hépatocarcinogenèse
Hepatocellular carcinoma (HCC) undergoes a stepwise progression from liver cirrhosis (LC) to low-grade dysplastic nodule (LGDN), high-grade dysplastic nodule (HGDN), early HCC (eHCC), and progressed HCC (pHCC). Here, we profiled multi-layered genomic, epigenomic, and transcriptomic aberrations in the stepwise hepatocarcinogenesis. Initial DNA methylation was observed in eHCC (e.g., DKK3, SALL3, and SOX1) while more extensive methylation was observed in pHCC. In addition, eHCCs showed an initial loss of DNA copy numbers of tumor suppressor genes in the 4q and 13q regions, thereby conferring survival benefits to cancer cells. Transcriptome analysis revealed that HGDNs expressed endoplasmic reticulum (ER) stress-related genes, while eHCC started to express oncogenes. Furthermore, integrative analysis indicated that expression of the serine peptidase inhibitor, Kazal type 1 (SPINK1), played a pivotal role in eHCC development. Significant demethylation of SPINK1 was observed in eHCC compared to HGDN. The study also demonstrated that ER stress may induce SPINK1 demethylation and expression in liver cancer cells. In conclusion, these results reveal the dynamics of multiomic aberrations during malignant conversion of liver cancer, thus providing novel pathobiological insights into hepatocarcinogenesis.