Telomere Maintenance Mechanisms Define Clinical Outcome in High-Risk Neuroblastoma

Cancer Res. 2020 Jun 15;80(12):2663-2675. doi: 10.1158/0008-5472.CAN-19-3068. Epub 2020 Apr 14.

Abstract

Neuroblastoma is a childhood cancer with heterogeneous clinical outcomes. To comprehensively assess the impact of telomere maintenance mechanism (TMM) on clinical outcomes in high-risk neuroblastoma, we integrated the C-circle assay [a marker for alternative lengthening of telomeres (ALT)], TERT mRNA expression by RNA-sequencing, whole-genome/exome sequencing, and clinical covariates in 134 neuroblastoma patient samples at diagnosis. In addition, we assessed TMM in neuroblastoma cell lines (n = 104) and patient-derived xenografts (n = 28). ALT was identified in 23.4% of high-risk neuroblastoma tumors and genomic alterations in ATRX were detected in 60% of ALT tumors; 40% of ALT tumors lacked genomic alterations in known ALT-associated genes. Patients with high-risk neuroblastoma were classified into three subgroups (TERT-high, ALT+, and TERT-low/non-ALT) based on presence of C-circles and TERT mRNA expression (above or below median TERT expression). Event-free survival was similar among TERT-high, ALT+, or TERT-low/non-ALT patients. However, overall survival (OS) for TERT-low/non-ALT patients was significantly higher relative to TERT-high or ALT patients (log-rank test; P < 0.01) independent of current clinical and molecular prognostic markers. Consistent with the observed higher OS in patients with TERT-low/non-ALT tumors, continuous shortening of telomeres and decreasing viability occurred in low TERT-expressing, non-ALT patient-derived high-risk neuroblastoma cell lines. These findings demonstrate that assaying TMM with TERT mRNA expression and C-circles provides precise stratification of high-risk neuroblastoma into three subgroups with substantially different OS: a previously undescribed TERT-low/non-ALT cohort with superior OS (even after relapse) and two cohorts of patients with poor survival that have distinct molecular therapeutic targets. SIGNIFICANCE: These findings assess telomere maintenance mechanisms with TERT mRNA and the ALT DNA biomarker C-circles to stratify neuroblastoma into three groups, with distinct overall survival independent of currently used clinical risk classifiers.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Child
  • Child, Preschool
  • Disease-Free Survival
  • Female
  • Follow-Up Studies
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Infant
  • Male
  • Neoplasm Recurrence, Local
  • Neuroblastoma / genetics*
  • Neuroblastoma / mortality
  • Neuroblastoma / pathology
  • RNA, Messenger / isolation & purification
  • RNA, Messenger / metabolism
  • RNA-Seq
  • Telomerase / genetics
  • Telomerase / isolation & purification
  • Telomerase / metabolism*
  • Telomere / metabolism*
  • Telomere Homeostasis*
  • Whole Genome Sequencing
  • X-linked Nuclear Protein / genetics
  • Xenograft Model Antitumor Assays

Substances

  • RNA, Messenger
  • TERT protein, human
  • Telomerase
  • ATRX protein, human
  • X-linked Nuclear Protein