biostudies-literatureUnknown16(9)Chebly ALigue Contre le CancerSociété Française de Dermatologie et de Pathologie Sexuellement TransmissibleCentre National de la Recherche ScientifiqueInstitut National de la Santé et de la Recherche MédicaleCutaneous T-cell lymphomas (CTCLs) are telomerase-positive tumors expressing hTERT, although neither gene rearrangement/amplification nor promoter hotspot mutations could explain the hTERT re-expression. As the hTERT promoter is rich in CpG, we investigated the contribution of epigenetic mechanisms in its re-expression. We analyzed hTERT promoter methylation status in CTCL cells compared with healthy cells. Gene-specific methylation analyses revealed a common methylation pattern exclusively in tumor cells. This methylation pattern encompassed a hypermethylated distal region from -650 to -150 bp and a hypomethylated proximal region from -150 to +150 bp. Interestingly, the hypermethylated region matches with the recently named TERT hypermethylated oncogenic region (THOR). THOR has been assocMolecular oncology1931-1946https://www.ebi.ac.uk/biostudies/studies/S-EPMC9067155biostudies-literatureExploring hTERT promoter methylation in cutaneous T-cell lymphomas.PMC9067155Segal-Bendirdjian EPham-Ledard AChouery ETomb RPoglio SProchazkova-Carlotti MIdrissi YRopio JBeylot-Barry MFerrer JMerlio JPChebly AChevret EPeloponese JMCherrier FFarra CfalseExploring hTERT promoter methylation in cutaneous T-cell lymphomas.Cutaneous T-cell lymphomas (CTCLs) are telomerase-positive tumors expressing hTERT, although neither gene rearrangement/amplification nor promoter hotspot mutations could explain the hTERT re-expression. As the hTERT promoter is rich in CpG, we investigated the contribution of epigenetic mechanisms in its re-expression. We analyzed hTERT promoter methylation status in CTCL cells compared with healthy cells. Gene-specific methylation analyses revealed a common methylation pattern exclusively in tumor cells. This methylation pattern encompassed a hypermethylated distal region from -650 to -150 bp and a hypomethylated proximal region from -150 to +150 bp. Interestingly, the hypermethylated region matches with the recently named TERT hypermethylated oncogenic region (THOR). THOR has been assoc2022-01-01T00:00:00Z2022 May2025-04-18T15:44:38.627Z2025-02-19T04:21:18.202ZS-EPMC90671553371527110.1002/1878-0261.12946