Insights into the genetic drivers of the disease were identified based on data from whole-genome, whole-exome, and/or transcriptome sequencing of tumor samples.
“The comprehensive genome-wide analysis performed here allowed us to discover age-associated alterations in MYCN, TERT, PTPRD, and Ras pathway alterations, which, together with ATRX, represent the majority of common driver gene alterations in neuroblastoma,” wrote study author Samuel W. Brady, PhD, of St. Jude Children’s Research Hospital in Memphis, Tenn., and colleagues.
The group’s findings were published in Nature Communications.
The researchers integrated and analyzed data from 702 neuroblastomas encompassing all age and risk categories, with the goal of identifying rare driver events and age-related molecular aberrations. Among the samples, 23 were from patients who had relapsed.
The researchers found that 40% of samples had somatic alterations in known driver genes, with the most common alterations being MYCN (19%; primarily amplification), TERT (17%; structural variations [SVs]), SHANK2 (13%; SVs), PTPRD (11%; SVs and focal deletions), ALK (10%; single nucleotide variants [SNVs] and SVs), and ATRX (8%; multiple mutation types).
MYCN and TERT alterations were more common in younger children (median age of 2.3 years and 3.8 years, respectively), while ATRX alterations were more frequently seen in older patients (median age of 5.6 years).
“These findings suggest that the sympathetic nervous system, the tissue from which neuroblastoma arises, is susceptible to different oncogenic insults at different times during development, which could be explored in future investigations using animal models,” the researchers wrote.
Furthermore, they found evidence to suggest the COSMIC mutational signature 18 is the most common cause of driver SNVs in neuroblastoma, including most Ras-activating and ALK variants.
Signature 18 was enriched in neuroblastomas with increased expression of mitochondrial ribosome and electron transport–associated genes, 17q gain, and MYCN amplification.
“[T]his mutagenic process, which is caused by ROS [reactive oxygen species] in other settings (though not proven in neuroblastoma), may promote evolution and heterogeneity, as many driver SNVs, such as ALK mutations, are later events in neuroblastoma,” the researchers explained.
Based on these findings, the authors concluded that neuroblastomas with 17q gain may be amenable to precision medicines, possibly through targeting altered mitochondrial function.
“[Our] findings will identify patients who might be eligible for targeted therapy and those that may be at higher risk based on a combination of genetic alterations detected by these genome-wide sequencing methods,” commented study author Jinghui Zhang, PhD, of St. Jude Children’s Research Hospital.
The study was supported by grants from the National Cancer Institute and by the American Lebanese Syrian Associated Charities of St. Jude Children’s Research Hospital. One author disclosed financial affiliations with Y-mabs Therapeutics, Abpro-Labs, Eureka Therapeutics, and Biotec Pharmacon.
SOURCE: Brady SW et al. Nat Commun. 2020 Oct 14. doi: 10.1038/s41467-020-18987-4.