Maintenance of telomere length is a critical hallmark of malignant transformation. While silenced in somatic cells, telomerase reverse transcriptase (TERT), the catalytic subunit of telomerase, is frequently overexpressed in malignant cells thereby maintaining their telomere length. Specific point mutations in the TERT promoter region have recently been identified in melanoma and other tumor entities resulting in high TERT expression. Neuroblastoma is the most common extracranial tumor of childhood, arising from neural-crest progenitor cells. TERT overexpression has been observed in the majority of neuroblastoma. Taking into consideration that TERT promoter mutations are frequently described in neural-crest-derived tumors such as melanoma, as well as a variety of other neuronal tumors, the present study analyzed the frequency of TERT promoter mutations in primary neuroblastoma and neuroblastoma cell lines. In 131 neuroblastoma primary tumors representing the whole spectrum of neuroblastoma, no TERT promoter mutations were detected. However, in 3 out of 19 neuroblastoma cell lines the previously described C228T TERT promoter mutation was present. In conclusion, the TERT promoter mutations are not a frequent mechanism of TERT overexpression in neuroblastoma.
Keywords: alternative lengthening of telomeres; neuroblastoma; sequencing; telomerase reverse transcriptase; telomeres.