Telomerase activity by TRAP assay and telomerase RNA (hTR) expression are predictive of outcome in neuroblastoma

Background. Recent studies have associated telomerase with prognostic facto rs and survival in neuroblastoma. Procedure. We examined telomerase activit y by telomere repeal amplification protocol (TRAP) and expression of the RN A component of telomerase (hTR) by Northern blotting in 106 primary neurobl astoma tumors and 22 established cell lines. Results. Overall survival at 5 years for all 106 tumors was significantly better for patients with undete ctable TRAP (75% vs. 59%; P = 0.03) or low hTR expression (84% vs. 43%; P < 0.0001), and especially for patients whose tumors had both low hTR express ion and undetectable TRAP (all patients, 91% vs. 54%, P = 0.0002; for 17 st age IV-S tumors, 100% vs. 72%, P = 0.04). Strong expression of hTR was seen in 22 cell lines from aggressive tumors, and all maintained telomere lengt h, but 3/22 were TRAP negative. Conclusions. These data suggest that both h TR expression and telomerase activity via the TRAP assay should be performe d concurrently to predict survival in neuroblastoma patients, particularly in stage 4-S. Med. Pediatr. Oncol. 35:647-650, 2000. (C) 2000 Wiley-Liss. I nc.