Jmjd2/Kdm4 demethylases are required for expression of Il3ra and survival of acute myeloid leukemia cells
GENES & DEVELOPMENT
Authors: Agger, Karl; Miyagi, Satoru; Pedersen, Marianne Terndrup; Kooistra, Susanne M.; Johansen, Jens Vilstrup; Helin, Kristian
Abstract
Acute myeloid leukemias (AMLs) with a rearrangement of the mixed-linage leukemia (MLL) gene are aggressive hematopoietic malignancies. Here, we explored the feasibility of using the H3K9- and H3K36-specific demethylases Jmjd2/Kdm4 as putative drug targets in MLL-AF9 translocated leukemia. Using Jmjd2a, Jmjd2b, and Jmjd2c conditional triple-knockout mice, we show that Jmjd2/Kdm4 activities are required for MLL-AF9 translocated AML in vivo and in vitro. We demonstrate that expression of the interleukin 3 receptor a (Il3ra also known as Cd123) subunit is dependent on Jmjd2/Kdm4 through a mechanism involving removal of H3K9me3 from the promoter of the Il3ra gene. Importantly, ectopic expression of Il3ra in Jmjd2/Kdm4 knockout cells alleviates the requirement of Jmjd2/Kdm4 for the survival of AML cells, showing that Il3ra is a critical downstream target of Jmjd2/Kdm4 in leukemia. These results suggest that the JMJD2/KDM4 proteins are promising drug targets for the treatment of AML.
Prognostic gene alterations and clonal changes in childhood B-ALL
LEUKEMIA RESEARCH
Authors: Erbilgin, Yucel; Firtina, Sinem; Mercan, Sevcan; Ng, Ozden Hatirnaz; Karaman, Serap; Tasar, Orcun; Karakas, Zeynep; Celkan, Tulin Tiraje; Zenging, Emine; Sarperg, Nazan; Yildirmak, Zeynep Yildiz; Sisko, Sinem; Ozbek, Ugur; Sayitoglu, Muge
Abstract
Genomic profiles of leukemia patients lead to characterization of variations that provide the molecular classification of risk groups, prediction of clinical outcome and therapeutic decisions. In this study, we examined the diagnostic (n = 77) and relapsed (n = 31) pediatric B-cell acute lymphoblastic leukemia (B-ALL) samples for the most common leukemia-associated gene variations CRLF2, JAK2, PAX5 and IL7R using deep sequencing and copy number alterations (CNAs) (CDKN2A/2B, PAX5, RB1, BTG1, ETV6, CSF2RA, IL3RA and CRLF2) by multiplex ligation proximity assay (MLPA), and evaluated for the clonal changes through relapse. Single nucleotide variations SNVs were detected in 19% of diagnostic 15.3% of relapse samples. The CNAs were detected in 55% of diagnosed patients; most common affected genes were CDKN2A/2B, PAX5, and CRLF2. Relapse samples did not accumulate a greater number of CNAs or SNVs than the cohort of diagnostic samples, but the clonal dynamics showed the accumulation/disappearance of specific gene variations explained the course of relapse. The CDKN2A/2B were most frequently altered in relapse samples and 32% of relapse samples carried at least one CNA. Moreover, CDKN2A/2B alterations and/or JAK2 variations were associated with decreased relapse-free survival. On the other hand, CRLF2 copy number alterations predicted a better survival rate in B-ALL. These findings contribute to the knowledge of CDKN2A/2B and CRLF2 alterations and their prognostic value in B-ALL. The integration of genomic data in clinical practice will enable better stratification of ALL patients and allow deeper understanding of the nature of relapse.