Abstract 3997: Expression profiling of a panel of apoptosis-associated microRNAs in acute myeloid leukemia identifies differentially expressed microRNAs that target epigenetic modifiers

Abstract

Abstract Introduction: Identifying molecular aberrations in Acute Myeloid Leukemia (AML) is still an unmet research target. We evaluated the expression of a panel of apoptosis-associated microRNAs (miRNAs) in leukemic blasts isolated from AML patients and investigated their predicted targets. Methods: We used bone marrow or peripheral blood that were donated by eight AML patients (5 male, 3 female) at diagnosis. Mononuclear cells were isolated by Ficoll-Histopaque (Sigma Aldrich) density gradient centrifugation and were cryopreserved in liquid nitrogen at the Cancer Biobank Center of the University of Ioannina. MicroBeads technology was used for magnetic cell sorting of CD34+ cells of patients’ samples, while mononuclear blood cells from healthy individuals were used as controls. Small RNA (< 200 b) was isolated using the NucleoSpin® miRNA kit (Macherey Nagel). Simultaneous quantification of 84 apoptosis-associated miRNAs was performed by using the miScript miRNA PCR Array Human Apoptosis (MIHS-114ZF, Qiagen) in a LightCycler® 480 instrument (Roche AG, Rotkreuz, Switzerland), and relative quantitation of expression was determined by the comparative CT method. For miRNA target prediction we used the RNA22 tool: http://cm.jefferson.edu/rna22v2 and http://cm.jefferson.edu/rna22v2.0. Results: We found 51 downregulated and 12 upregulated miRNAs compared to control. Among the downregulated miRNAs was the miR-29 family and among the upregulated was the miR-181 family, both of which have been previously implicated in AML. The top 10 downregulated miRNAs were miR-31-5p, miR-451a, miR-144-3p, miR-29b-3p, miR-204-5p, miR-9-5p, miR-409-3p, miR-542-3p, miR-29c-3p and miR-29a-3p, whereas the top 10 upregulated miRNAs were miR-186-3p, miR-149-3p, let-7c-5p, miR-222-3p, miR-214-3p, miR-181c-5p, miR-181a-5p, miR-181b-5p, miR-34a-5p and miR-181d-5p. Deepest downregulation (over -50fold) was seen for miR-144-3p, miR-451a and miR-31-5p. We used RNA22 to identify genes that are predicted to be simultaneously targeted by all of the 10 top downregulated miRNAs and also the genes that are predicted to be simultaneously targeted by all of the 10 top upregulated miRNAs. The predicted targets for all top 10 downregulated miRNAs include NSD1, KAT6B and SACS. NSD1 is an histone methyltransferase, whereas KAT6B is an histone acetyltransferase. The predicted targets of all top 10 upregulated miRNAs include 36 genes among which are DICER1, ZNF507, ZNF704 and MLLT6. Conclusions: A variety of microRNAs are dysregylated in patients with AML. We confirm that the miR-29 family and the miR-181 family have altered expression in AML. Among predicted targets of the downregulated miRNAs are genes involved in chromatin remodelling, suggesting that altered function of epigenetic modifiers in AML may be due to dysregylation of miRNAs. Citation Format: Eleftheria Hatzimichael, Aggeliki Dasoula, Maria Igglezou, Andreas Katsenos, Ioannis Sainis, Isidore Rigoutsos, Evangelos Briasoulis. Expression profiling of a panel of apoptosis-associated microRNAs in acute myeloid leukemia identifies differentially expressed microRNAs that target epigenetic modifiers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3997. doi:10.1158/1538-7445.AM2015-3997