Acetylation-dependent regulation of core spliceosome modulates hepatocellular carcinoma cassette exons and sensitivity to PARP inhibitors

Nat Commun. 2024 Jun 18;15(1):5209. doi: 10.1038/s41467-024-49573-7.

Abstract

Despite the importance of spliceosome core components in cellular processes, their roles in cancer development, including hepatocellular carcinoma (HCC), remain poorly understood. In this study, we uncover a critical role for SmD2, a core component of the spliceosome machinery, in modulating DNA damage in HCC through its impact on BRCA1/FANC cassette exons and expression. Our findings reveal that SmD2 depletion sensitizes HCC cells to PARP inhibitors, expanding the potential therapeutic targets. We also demonstrate that SmD2 acetylation by p300 leads to its degradation, while HDAC2-mediated deacetylation stabilizes SmD2. Importantly, we show that the combination of Romidepsin and Olaparib exhibits significant therapeutic potential in multiple HCC models, highlighting the promise of targeting SmD2 acetylation and HDAC2 inhibition alongside PARP inhibitors for HCC treatment.

MeSH terms

  • Acetylation
  • Animals
  • BRCA1 Protein / genetics
  • BRCA1 Protein / metabolism
  • Carcinoma, Hepatocellular* / drug therapy
  • Carcinoma, Hepatocellular* / genetics
  • Carcinoma, Hepatocellular* / metabolism
  • Carcinoma, Hepatocellular* / pathology
  • Cell Line, Tumor
  • DNA Damage / drug effects
  • Depsipeptides / pharmacology
  • Depsipeptides / therapeutic use
  • Exons* / genetics
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Liver Neoplasms* / drug therapy
  • Liver Neoplasms* / genetics
  • Liver Neoplasms* / metabolism
  • Liver Neoplasms* / pathology
  • Mice
  • Phthalazines* / pharmacology
  • Piperazines* / pharmacology
  • Poly(ADP-ribose) Polymerase Inhibitors* / pharmacology
  • Spliceosomes* / drug effects
  • Spliceosomes* / metabolism

Substances

  • Poly(ADP-ribose) Polymerase Inhibitors
  • olaparib
  • Phthalazines
  • Piperazines
  • romidepsin
  • BRCA1 Protein
  • Depsipeptides
  • BRCA1 protein, human