Abstract 6254: Casein kinase II (CK2) expression in pediatric solid tumors

Abstract Despite recent advances, high-risk neuroblastoma (NB) and sarcomas account for 15% and 5% of all pediatric cancer deaths, respectively. Many patients attain remission, but approximately half of patients relapse. Genomic alterations such as MYCN amplification and ALK mutations have been shown to be important in prognosis and treatment. Despite improvements, approximately 20% of patients have refractory or recurrent disease after therapy, underscoring the need for further genomic understanding and new approaches to treatment. CK2 is a serine/threonine kinase that regulates numerous cellular processes such as cell growth, proliferation, and survival. Overexpression of CK2 is associated with a poor prognosis in several adult solid tumors, making it a potential target of interest in pediatric solid tumors. This study aims to investigate CK2 expression among patients with NB, Ewing sarcoma (EWS), and rhabdomyosarcoma (RMS) and its correlation with patient survival. MethodsPatients were enrolled in NMTRC008/009: “Feasibility Trial Using Molecular Guided Therapy for Patients with Relapsed/Refractory Childhood Cancer” and BCC-001. WES and RNA-Seq were performed at the Translational Genomics Research Institute and Sema4 or Caris respectively. RNA expression levels were compared to a normal whole-body reference and a pediatric cancer reference. Differential expression data were interpreted in the context of systems biology. ResultsTumor WES was performed on 297 patients (212 NB, 50 EWS, 35 RMS) and RNA-Seq on 284 patients (210 NB, 39 EWS, 35 RMS). The most common mutations or copy number alterations were seen in MYCN, ATRX, ALK, CDKN2A, and chr17q+ in NB; EWSR1-FLI1 fusion in EWS; PAX3-FOXO1 fusion in RMS. RNA expression analysis was performed to understand MYCN-driver status by covariance and interactions and to identify subsets of patients with high/low expression of CK2 in different tumors. CK2 bimodal expression is seen across various cancers and normal tissues, implying distinct sub-groups exist in the data. In NB, overexpression of the CK2 gene with statistical significance was found in MYCN-amplified and chr17q+ tumors. A positive and negative correlation of the CK2 gene is seen with several target genes like MYCN, TRIM71, LIN28B, and HMGA2, JAK2, AR, STAT3, EGFR, LEF1, and NFKB2, respectively. In EWS and RMS, subgroups are identified with high and low expression of the CK2 gene. ConclusionGenomic sequencing of pediatric solid tumors showed a low mutation burden. RNA analysis resulted in the identification of potential novel therapeutic targets involving CK2 pathways. High expression of CK2 correlates with MYCN status. Further analysis of patient molecular subgroups is ongoing. Citation Format: Abhinav Beeravally Nagulapally, Chandrika Behura, Divya Gandra, Giselle Saulnier Sholler. Casein kinase II (CK2) expression in pediatric solid tumors abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 6254.