Regulation of the lncRNA NEAT1 by p53-ΔNp63 crosstalk modulates the DNA damage response and therapeutic efficacy in HNSCC.

Abstract

Head and neck squamous cell carcinomas (HNSCCs) are characterized by recurrent genetic alterations, including the inactivation of the tumor suppressor TP53 gene and dysregulation of the TP63 gene. The TP63 gene encodes multiple isoforms, among which the N-terminal truncated isoform ΔNp63 is fundamental for the integrity of stratified epithelial tissues. We previously demonstrated that ΔNp63 represses the expression of the lncRNA NEAT1. Here, we investigated the functional crosstalk between p53 and ΔNp63 in modulating NEAT1 expression following genotoxic stress. We found that upon genotoxic insults, p53 activation and the concomitant downregulation of ΔNp63 promote NEAT1 transcription. In p53-proficient HNSCC cells, NEAT1 targeting leads to increased DNA damage, highlighting its potential role in maintaining genomic stability and facilitating efficient DNA repair. Importantly, we showed that histone deacetylase inhibitors (HDACis) upregulate NEAT1 expression independently of p53, and NEAT1 silencing enhances HDACis-induced DNA damage. Overall, our findings establish NEAT1 as an early regulator of the DNA damage response in HNSCCs and suggest that combining NEAT1 targeting with HDAC inhibition may potentiate therapeutic efficacy, particularly in TP53-mutant HNSCCs.