RT Journal Article SR Electronic T1 miR-497 suppresses cycle progression through an axis involving CDK6 in ALK-positive cells JF Haematologica JO Haematologica FD Ferrata Storti Foundation SP 347 OP 359 DO 10.3324/haematol.2018.195131 VO 104 IS 2 A1 Hoareau-Aveilla, Coralie A1 Quelen, Cathy A1 Congras, Annabelle A1 Caillet, Nina A1 Labourdette, Delphine A1 Dozier, Christine A1 Brousset, Pierre A1 Lamant, Laurence A1 Meggetto, Fabienne YR 2019 UL http://www.haematologica.org/content/104/2/347.abstract AB Anaplastic large-cell lymphoma, a T-cell neoplasm, is primarily a pediatric disease. Seventy-five percent of pediatric anaplastic large-cell lymphoma cases harbor the chromosomal translocation t(2;5)(p23;q35) leading to the ectopic expression of NPM-ALK, a chimeric tyrosine kinase. NPM-ALK consists of an N-terminal nucleophosmin (NPM) domain fused to an anaplastic lymphoma kinase (ALK) cytoplasmic domain. Pediatric NPM-ALK+ anaplastic large-cell lymphoma is often a disseminated disease and young patients are prone to chemoresistance or relapse shortly after chemotherapeutic treatment. Furthermore, there is no gold standard protocol for the treatment of relapses. To the best of our knowledge, this is the first study on the potential role of the microRNA, miR-497, in NPM-ALK+ anaplastic large-cell lymphoma tumorigenesis. Our results show that miR-497 expression is repressed in NPM-ALK+ cell lines and patient samples through the hypermethylation of its promoter and the activity of NPM-ALK is responsible for this epigenetic repression. We demonstrate that overexpression of miR-497 in human NPM-ALK+ anaplastic large-cell lymphoma cells inhibits cellular growth and causes cell cycle arrest by targeting CDK6, E2F3 and CCNE1, the three regulators of the G1 phase of the cell cycle. Interestingly, we show that a scoring system based on CDK6, E2F3 and CCNE1 expression could help to identify relapsing pediatric patients. In addition, we demonstrate the sensitivity of NPM-ALK+ cells to CDK4/6 inhibition using for the first time a selective inhibitor, palbociclib. Together, our findings suggest that CDK6 could be a therapeutic target for the development of future treatments for NPM-ALK+ anaplastic large-cell lymphoma.