Abstract 699: NF-kB is a master regulator of resistance to therapy in high-risk neuroblastoma

• Published in: Cancer research (Chicago, Ill.) Ill.), 2022-06, Vol.82 (12_Supplement), p.699-699
• Main Authors: Grossmann, Liron D., Uzun, Yasin, Lindsay, Jarrett, Chen, Chia-Hui, Wingrove, Catherine, Gao, Peng, Thadi, Anusha, Marshall, Quinlen, Kendsersky, Nathan M., Surrey, Lea, Martinez, Daniel, Mycek, Emily, Casey, Colleen, Krytska, Kateryna, Tsang, Matthew, Wolpaw, Adam, Groff, David N., Runbeck, Erin, McDevitt, Jayne, Diep, Dinh, Patel, Tasleema, Bernt, Kathrin M., Dang, Chi, Zhang, Kun, Mosse, Yael P., Tan, Kai, Maris, John M.
• Format: Article
• Language: English
• ISSN: 1538-7445; 1538-7445
• DOI: 10.1158/1538-7445.AM2022-699

BACKGROUND High-risk neuroblastoma is a pediatric cancer arising from the developing sympathetic nervous system with a 50% relapse rate that is typically fatal. At least two subpopulations of neuroblastoma cells exist that can transdifferentiate, adrenergic and mesenchymal, the latter being more resistant to chemotherapy. Mechanisms of therapy resistance are largely unknown and the cells responsible for relapse have not been identified. METHODS We used single nucleus RNA and ATAC sequencing to identify and characterize the cells that survive chemotherapy, termed here “persister cells”, from a cohort of 20 matched diagnostic and post induction chemotherapyhigh-risk neuroblastoma patients and two patient derived xenograft (PDX) models from diagnostic tumors. Eight representative cell lines derived from neuroblastomas at diagnosis were treated with standard-of-care chemotherapy, and flow cytometry was used to sort for live cells. ML120B and CRISPR-CAS9 were used to modulate NF-kB signaling. An RNA-seq dataset of 153 high-risk neuroblastoma patients was used to determine differentially activated pathways between adrenergic and mesenchymal tumors. RESULTS Residual malignant cells in the post-chemotherapy tumor samples clustered into three main groups separated by the response to therapy. The most prevalent group of persister cells in responders (N=16/20) displayed low MYC(N) activity even in the presence of MYCN amplification. This group also demonstrated decreased expression of the adrenergic core regulatory circuit genes including PHOX2B, ISL1, HAND2, along with marked activation of TNF-alpha via NF-kB signaling. High NF-kB activity was found in a subpopulation of diagnostic cells in two chemo-refractory patients. We validated decreased expression of MYCN (2-fold decrease, p