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Date publication

juin 2011

Auteurs

Membres identifiés du Cancéropôle Est :
Pr BASTIE Jean-Noël , Dr DELVA Laurent , Pr MARTIN Laurent , Dr AUCAGNE Romain , Mme BATAILLE Amandine


Tous les auteurs :
Aucagne R, Droin N, Paggetti J, Lagrange B, Largeot A, Hammann A, Bataille A, Martin L, Yan KP, Fenaux P, Losson R, Solary E, Bastie JN, Delva L

Résumé

Transcription intermediary factor 1gamma (TIF1gamma) was suggested to play a role in erythropoiesis. However, how TIF1gamma regulates the development of different blood cell lineages and whether TIF1gamma is involved in human hematological malignancies remain to be determined. Here we have shown that TIF1gamma was a tumor suppressor in mouse and human chronic myelomonocytic leukemia (CMML). Loss of Tif1g in mouse HSCs favored the expansion of the granulo-monocytic progenitor compartment. Furthermore, Tif1g deletion induced the age-dependent appearance of a cell-autonomous myeloproliferative disorder in mice that recapitulated essential characteristics of human CMML. TIF1gamma was almost undetectable in leukemic cells of 35% of CMML patients. This downregulation was related to the hypermethylation of CpG sequences and specific histone modifications in the gene promoter. A demethylating agent restored the normal epigenetic status of the TIF1G promoter in human cells, which correlated with a reestablishment of TIF1gamma expression. Together, these results demonstrate that TIF1G is an epigenetically regulated tumor suppressor gene in hematopoietic cells and suggest that changes in TIF1gamma expression may be a biomarker of response to demethylating agents in CMML.

Référence

J Clin Invest. 2011 Jun 1;121(6):2361-70