RUVBL1 and RUVBL2 as novel druggable DNA Damage Response regulators in the N-Myc regulatory network in neuroblastoma

Abstract

Abstract High-risk neuroblastoma (NB) accounts for about 50% of all cases. These tumours are characterized by MYCN amplification and high MYC gene expression and patients have a high relapse rate despite intensive therapies, hence the need for safer and more effective drugs. Strategies to develop inhibitors that directly target the MYC proteins have been elusive. Based on in silico molecular signature score and network analyses, we identified RUVBL2 as a key interactor of MYC. Kaplan-Meier survival and multivariate Cox regression analyses using public NB datasets demonstrated that expression of RUVBL2 and its interaction partner RUVBL1 are strong and independent predictors for both overall and event-free survival in NB patients. Using different types of NB cell lines, we experimentally demonstrated that transient knockdown of RUVBL1/2 or pharmacological inhibition using CB-6644 resulted in cell cycle arrest, cell growth arrest and a DNA Damage Response (DDR) through regulation of ATR and ATM. Additionally we confirmed that RUVBL1/2 transcriptionally regulate MYCN and MYC. Our work demonstrates that RUVBL1 and RUVBL2 are novel regulators of the DDR with therapeutic and independent prognostic potential in high-risk NB.