Dataset Information

The dependency factor RRM2 at the nexus of a copy number driven regulatory network and a target for synthetic lethal interactions with replication stress checkpoint addiction in high-risk neuroblastoma [siRNA_RRM2]

ABSTRACT: Neuroblastoma is a pediatric tumor originating from the sympathetic nervous system responsible for 10-15% of all childhood cancer deaths. Half of all neuroblastoma patients present with high-risk disease at diagnosis despite intensive multi-modal therapies of which nearly 50% relapse and die of their disease. In contrast to the overall paucity of mutations, high-risk neuroblastoma nearly invariably present with recurrent somatic segmental chromosome copy number variants. For several focal aberrations (e.g. MYCN and LIN28B amplification), the direct role in tumor formation has been established. However, for recurrent aberrations, such as chromosome 2p and 17q gains, the identification of genes contributing to tumor initiation or progression has been challenging due to the scarcity of small segmental gains or amplifications. In this study, we identified and functionally evaluated the ‘ribonucleotide reductase regulatory subunit 2’ (RRM2) as a top-ranked 2p putative co-driver and therapeutic target in high-risk neuroblastoma enforcing replicative stress resistance. RRM2 dependency was shown in vitro through knockdown in neuroblastoma cells, with transcriptome analysis revealing downregulation of pediatric tumor markers. Transgenic zebrafish lines expressing RRM2 in immature sympathoblasts were crossed with a dh-MYCN transgenic zebrafish line, with RRM2 overexpression dramatically increasing tumor penetrance from 20% to nearly 100%, accelerating neuroblastoma formation with tumors formed as early as 5 weeks of age in the double positive fish. Through CasID, we aimed to identify RRM2 promotor bound proteins. and enriched amongst others HEXIM1 and the NurRD complex. Importantly, adaptive responses regulating RRM2 expression are also controlled by ATR/CHK1 and WEE1 cell cycle checkpoint kinases, as shown by pharmacological inhibition with small molecule inhibitors. We provide in vitro and in vivo data showing that RRM2 inhibition with triapine strongly sensitizes neuroblastoma cells to CHK1 inhibition and that combined treatment could robustly induce upregulated PD-L1 surface expression. Altogether, we propose RRM2 as a bona fide target to explore novel synergistic drug combinations through phase I clinical trials.

ORGANISM(S): Homo sapiens

PROVIDER: GSE161899 | GEO | 2022/08/03

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Neuroblastoma is a pediatric tumor originating from the sympathetic nervous system responsible for 10-15% of all childhood cancer deaths. Half of all neuroblastoma patients present with high-risk disease at diagnosis despite intensive multi-modal therapies of which nearly 50% relapse and die of their disease. In contrast to the overall paucity of mutations, high-risk neuroblastoma nearly invariably present with recurrent somatic segmental chromosome copy number variants. For several focal aberrations (e.g. MYCN and LIN28B amplification), the direct role in tumor formation has been established. However, for recurrent aberrations, such as chromosome 2p and 17q gains, the identification of genes contributing to tumor initiation or progression has been challenging due to the scarcity of small segmental gains or amplifications. In this study, we identified and functionally evaluated the ‘ribonucleotide reductase regulatory subunit 2’ (RRM2) as a top-ranked 2p putative co-driver and therapeutic target in high-risk neuroblastoma enforcing replicative stress resistance. RRM2 dependency was shown in vitro through knockdown in neuroblastoma cells, with transcriptome analysis revealing downregulation of pediatric tumor markers. Transgenic zebrafish lines expressing RRM2 in immature sympathoblasts were crossed with a dh-MYCN transgenic zebrafish line, with RRM2 overexpression dramatically increasing tumor penetrance from 20% to nearly 100%, accelerating neuroblastoma formation with tumors formed as early as 5 weeks of age in the double positive fish. Through CasID, we aimed to identify RRM2 promotor bound proteins. and enriched amongst others HEXIM1 and the NurRD complex. Importantly, adaptive responses regulating RRM2 expression are also controlled by ATR/CHK1 and WEE1 cell cycle checkpoint kinases, as shown by pharmacological inhibition with small molecule inhibitors. We provide in vitro and in vivo data showing that RRM2 inhibition with triapine strongly sensitizes neuroblastoma cells to CHK1 inhibition and that combined treatment could robustly induce upregulated PD-L1 surface expression. Altogether, we propose RRM2 as a bona fide target to explore novel synergistic drug combinations through phase I clinical trials.

Project description:In neuroblastoma, amplification of the oncogenic basic helix-loop-helix (bHLH) transcription factor (TF) MYCN is the defining prognosticator of high-risk disease, occurs in one-third of neuroblastoma, and drastically reduces overall survival rates. As a proto-oncogene, targeted MYCN overexpression in peripheral neural crest is sufficient to initiate disease in mouse models. In MYCN amplified neuroblastoma, elevated expression of the factor is crucial to maintain tumor stemness and is associated with increased proliferation and aberrant cell cycle progression, as these tumors lack the ability to arrest in G1 in response to irradiation. MYCN down-regulation broadly reverses these oncogenic phenotypes in a variety of neuroblastoma models and recent thereapeutic strategies to indirectly target MYCN production or protein stability have reduced tumor growth in vivo. These observations motivate an investigation of MYCN binding in MYCN amplified tumors as it remains fundamentally unclear how elevated levels of the factor occupy the genome and alter transcriptional programs in neuroblastoma. Here we present the first dynamic chromatin and transcriptional landscape of direct MYCN perturbation in neuroblastoma. We find that at oncogenic levels, MYCN associates with E-box (CANNTG) binding motifs in an affinity dependent manner across most active cis-regulatory promoters and enhancers. MYCN shutdown globally reduces histone acetylation and transcription, consistent with prior descriptions of MYC proteins as non-linear amplifiers of gene expression. We establish that MYCN load at the promoter and proximal enhancers predicts transcriptional responsiveness to MYCN shutdown and that MYCN enhancer binding occurs prominently at the most strongly occupied and down-regulated genes, suggesting a role for these tissue specific elements in predicating MYCN responsive âtargetâ genes. At these invaded enhancers, we identify the lineage specific bHLH TWIST1 as a key collaborator and dependency of oncogenic MYCN. These data suggest that MYCN enhancer invasion helps shape transcriptional amplification of the neuroblastoma gene expression program to promote tumorigenesis. ChIP-Seq in SHEP21, BE2C, KELLY, and NGP neuroblastoma cell lines for H3K27ac, H3K4me3, RNA PolII, MYCN, BRD4, or TWIST1

Dataset Information

The dependency factor RRM2 at the nexus of a copy number driven regulatory network and a target for synthetic lethal interactions with replication stress checkpoint addiction in high-risk neuroblastoma [siRNA_RRM2]

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets