Hotspot TERT promoter mutations are rare events in testicular germ cell tumors

Flavio Mavignier Cárcano, Daniel Onofre Vidal, André van Helvoort Lengert, Cristovam Scapulatempo Neto, Luisa Queiroz, Herlander Marques, Fátima Baltazar, Camila Maria da Silva Martinelli, Paula Soares, Eduardo Caetano Albino da Silva, Luiz Fernando Lopes, Rui Manuel Reis

The abnormal activation of telomerase, codified by the telomerase reverse transcriptase (TERT) gene, is related to one of cancer hallmarks. Hotspot somatic mutations in the promoter region of TERT, specifically the c.-124:C>T and c.-146:C>T, were recently identified in a range of human cancers and have been associated with a more aggressive behavior. Testicular germ cell tumors frequently exhibit a good prognosis; however, the development of refractory disease is still a clinical challenge. In this study, we aim to evaluate for the first time the presence of the hotspot telomerase reverse transcriptase gene promoter mutations in testicular germ cell tumors. A series of 150 testicular germ cell tumor cases and four germ cell tumor cell lines were evaluated by PCR followed by direct Sanger sequencing and correlated with patient's clinical pathological features. Additionally, we genotyped the telomerase reverse transcriptase gene promoter single nucleotide polymorphism rs2853669 (T>C) located at -245 position. We observed the presence of the TERT promoter mutation in four patients, one exhibited the c.-124:C>T and three the c.-146:C>T. No association between TERT mutation status and clinicopathological features could be identified. The analysis of the rs2853669 showed that variant C was present in 22.8 % of the cases. In conclusion, we showed for the first time that TERT promoter mutations occur in a small subset (~3 %) of testicular germ cell tumors.