Deficiency of miR-155 in Leukemic B-Cells Results in Cell Cycle Arrest and Deregulation of MIR155HG/TP53INP1/CDKN1A/CCND1 network

• Published in: Archives of medical research Vol. 56; no. 3; p. 103124
• Main Authors: Golovina, Elena, Kokavec, Juraj, Kazantsev, Dmitry, Yurikova, Oxana, Bajecny, Martin, Savvulidi, Filipp Georgijevic, Simersky, Radim, Lenobel, Rene, Tost, Jorg, Herynek, Vit, Sefc, Ludek, Sebela, Marek, Klener, Pavel, Zemanova, Zuzana, Stopka, Tomas, Vargova, Karina Savvulidi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2025; Elsevier
• Subjects: B-cells; Biochemistry, Molecular Biology; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cell cycle; Cell Cycle Checkpoints - genetics; Cell Line, Tumor; Cell Proliferation - genetics; CRISPR/Cas9; Cyclin D1 - genetics; Cyclin D1 - metabolism; Cyclin-Dependent Kinase Inhibitor p21 - genetics; Cyclin-Dependent Kinase Inhibitor p21 - metabolism; Gene Expression Regulation, Leukemic; Genomics; Heat-Shock Proteins; Humans; Leukemia; Leukemia, Lymphocytic, Chronic, B-Cell - genetics; Leukemia, Lymphocytic, Chronic, B-Cell - pathology; Life Sciences; MicroRNAs - genetics; MicroRNAs - metabolism; miR-155; B-cells; CRISPR/Cas9; miR-155; Leukemia; Cell cycle; miR-155 CRISPR/Cas9 Cell cycle B-cells Leukemia
• ISSN: 0188-4409; 1873-5487; 1873-5487
• DOI: 10.1016/j.arcmed.2024.103124

Cell cycle progression and leukemia development are tightly regulated processes in which even a small imbalance in the expression of cell cycle regulatory molecules and microRNAs (miRNAs) can lead to an increased risk of cancer/leukemia development. Here, we focus on the study of a ubiquitous, multifunctional, and oncogenic miRNA-hsa-miR-155–5p (miR-155, MIR155HG), which is overexpressed in malignancies including chronic lymphocytic leukemia (CLL). Nonetheless, the precise mechanism of how miR-155 regulates the cell cycle in leukemic cells remains the subject of extensive research. We edited the CLL cell line MEC-1 by CRISPR/Cas9 to introduce a short deletion within the MIR155HG gene. To describe changes at the transcriptome and miRNome level in miR-155-deficient cells, we performed mRNA-seq/miRNA-seq and validated changes by qRT-PCR. Flow cytometry was used to measure cell cycle kinetics. A WST-1 assay, hemocytometer, and Annexin V/PI staining assessed cell viability and proliferation. The limited but phenotypically robust miR-155 modification impaired cell proliferation, cell cycle, and cell ploidy. This was accompanied by overexpression of the negative cell cycle regulator p21/CDKN1A and Cyclin D1 (CCND1). We confirmed the overexpression of canonical miR-155 targets such as PU.1, FOS, SHIP-1, TP53INP1 and revealed new potential targets (FCRL5, ISG15, and MX1). We demonstrate that miR-155 deficiency impairs cell proliferation, cell cycle, transcriptome, and miRNome via deregulation of the MIR155HG/TP53INP1/CDKN1A/CCND1 axis. Our CLL model is valuable for further studies to manipulate miRNA levels to revert highly aggressive leukemic cells to nearly benign or non-leukemic types.