The Regulation, Targets and Clinical Relevance of Microrna Mir-650 in Chronic Lymphocytic Leukemia (CLL)

• Published in: Blood 2011-11, Vol.118 (21), p.3874-3874
• Main Authors: Mraz, Marek, Plevova, Karla, Dolezalova, Dasa, Stano-Kozubik, Katerina, Mayerova, Veronika, Cerna, Katerina, Musilova, Katerina, Pavlova, Sarka, Tichy, Boris, Lochmanova, Jana, Doubek, Michael, Brychtova, Yvona, Trbusek, Martin, Hampl, Ales, Mayer, Jiri, Pospisilova, Sarka
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V118.21.3874.3874

Abstract 3874 It is known that the biology of CLL and other B-cell malignancies is driven by processes dependent on immunoglobulin structure and BCR-signaling. Recently, our group and others have described the importance of miRNAs in CLL and their involvement in BCR-signaling, IgG production and V(D)J recombination. Considering the important functions of miRNAs it is remarkable that the human locus for immunoglobulin lambda light chain (IgL) contains a miR gene. The miR-650 gene is localized in exon 1 of IgL variable subgene (1st exon of V2 family members). The aim of this study was to reveal the regulation and expression of miR-650 in CLL and its relation to disease prognosis. CLL samples were separated by RosetteSep Human B Cell Enrichment Cocktail (obtained purity ≥95% of CD5+19+ cells). The expression of light chain surface immunoglobulin chain (lambda vs kappa) was determined by flow cytometry. The utilized IgL variable (V) segment was determined using BIOMED-2 protocol and sequencing. To study the relation of miR-650 expression and IgL rearrangement the surface expression of Ig light chain and the utilized V segment was determined in a CLL cohort containing 47 patients (λ n=27, κ n=19, λ+κ n=1). The gene expression was analyzed by TaqMan Assays (ABI) for mature miR-650 and protein-coding genes: CDK1, EBF3 and ING4. The western-blot for miR-650 targets was performed after transfection (48hrs/96hrs) of B-cell lines (NALM-6, MEC-1) with a short RNA mimicking miR-650 (Dharmacon). The analyses of miR-650 expression revealed that cells utilizing V2-8, V2-5, V2-14, V2-23 subgenes for IgL (n=14) had ∼10 fold higher expression of miR-650 (p