Open AccessExploring hTERT promoter methylation in cutaneous T‐cell lymphomas
Author(s) -
Chebly Alain,
Ropio Joana,
Peloponese JeanMarie,
Poglio Sandrine,
ProchazkovaCarlotti Martina,
Cherrier Floriane,
Ferrer Jacky,
Idrissi Yamina,
SegalBendirdjian Evelyne,
Chouery Eliane,
Farra Chantal,
PhamLedard Anne,
BeylotBarry Marie,
Merlio JeanPhilippe,
Tomb Roland,
Chevret Edith
Publication year - 2022
Publication title -
molecular oncology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.332
H-Index - 88
eISSN - 1878-0261
pISSN - 1574-7891
DOI - 10.1002/1878-0261.12946
Subject(s) - epigenetics , telomerase reverse transcriptase , cancer research , dna methylation , methylation , vorinostat , telomerase , cpg site , biology , methyltransferase , romidepsin , histone deacetylase , microbiology and biotechnology , gene expression , gene , histone , genetics
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 associated with telomerase reactivation in many cancers, but it has so far not been reported in cutaneous lymphomas. Additionally, we assessed the effect of THOR on two histone deacetylase inhibitors (HDACi), romidepsin and vorinostat, both approved for CTCL treatment and a DNA methyltransferase inhibitor (DNMTi) 5‐azacytidine, unapproved for CTCL. Contrary to our expectations, the findings reported herein revealed that THOR methylation is relatively stable under these epigenetic drugs' pressure, whereas these drugs reduced the hTERT gene expression.