Glucose homeostasis controls N-acetyltransferase 10-mediated ac4C modification of HK2 to drive gastric tumorigenesis

NAT10 inhibits the pyroptosis of laryngeal squamous cell carcinoma through ac4C modification of ELANE mRNA

BACKGROUND

Laryngeal squamous cell carcinoma (LSCC) is the most common type of head and neck malignancy. NAT10 is a catalytic enzyme for ac4C and is involved in the progression of a variety of cancers. This study aimed to explore the effects and potential mechanisms of NAT10 in LSCC.

METHODS

Pyroptosis was assessed by measuring the release of lactic dehydrogenase, pyroptosis rate, and pyroptosis-related proteins. The RNA and protein levels were detected by quantitative real-time PCR and western blot, respectively. Potential mechanisms were validated using flow cytometry, ac4C dot blot, methylated RNA immunoprecipitation (MeRIP), RIP, and Dual-Luciferase Reporter Assay experiments.

RESULTS

The result showed that the levels of NAT10 in LSCC tissues and cells were elevated and positively correlated with tumor grading and clinical staging. Knockdown of NAT10 promoted the pyroptosis of LSCC cells. NAT10 directly interacted with ELANE, suppressed the stability of the ELANE mRNA. NAT10 inhibited pyroptosis in LSCC by downregulating the ELANE expression in vivo and in vitro.

CONCLUSION

NAT10 inhibited the pyroptosis of LSCC cells and contributed to LSCC progression by suppressing ELANE mRNA stability in ac4C modification manner, indicating that the NAT10-ac4C-ELANE axis might be a potential target for LSCC.

Targeting NAT10 attenuates homologous recombination via destabilizing DNA:RNA hybrids and overcomes PARP inhibitor resistance in cancers

AIMS

RNA metabolism has been extensively studied in DNA double-strand break (DSB) repair. The RNA acetyltransferase N-acetyltransferase 10 (NAT10)-mediated N4-acetylcytidine (ac4C) modification in DSB repair remains largely elusive. In this study, we aim to decipher the role for ac4C modification by NAT10 in DSB repair in hepatocellular carcinoma (HCC).

METHODS

Laser micro-irradiation and chromatin immunoprecipitation (ChIP) were used to assess the accumulation of ac4C modification and NAT10 at DSB sites. Cryo-electron microscopy (cryo-EM) was used to determine the structures of NAT10 in complex with its inhibitor, remodelin. Hepatocyte-specific deletion of NAT10 mouse models were adopted to detect the effects of NAT10 on HCC progression. Subcutaneous xenograft, human HCC organoid and patient-derived xenograft (PDX) model were exploited to determine the therapy efficiency of the combination of a poly (ADP-ribose) polymerase 1 (PARP1) inhibitor (PARPi) and remodelin.

RESULTS

NAT10 promptly accumulates at DSB sites, where it executes ac4C modification on RNAs at DNA:RNA hybrids dependent on PARP1. This in turn enhances the stability of DNA:RNA hybrids and promotes homologous recombination (HR) repair. The ablation of NAT10 curtails HCC progression. Furthermore, the cryo-EM yields a remarkable 2.9 angstroms resolution structure of NAT10-remodelin, showcasing a C2 symmetric architecture. Remodelin treatment significantly enhanced the sensitivity of HCC cells to a PARPi and targeting NAT10 also restored sensitivity to a PARPi in ovarian and breast cancer cells that had developed resistance.

CONCLUSION

Our study elucidated the mechanism of NAT10-mediated ac4C modification in DSB repair, revealing that targeting NAT10 confers synthetic lethality to PARP inhibition in HCC. Our findings suggest that co-inhibition of NAT10 and PARP1 is an effective novel therapeutic strategy for patients with HCC and have the potential to overcome PARPi resistance.