Cancer Management and Research (Nov 2018)
Epigenetic regulation of HOTAIR in advanced chronic myeloid leukemia
Abstract
Ziye Li, Jianmin Luo Department of Hematology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, People’s Republic of China Purpose: Chronic myeloid leukemia (CML) accounts for ~10% of leukemia cases, and its progression involves epigenetic gene regulation. This study investigated epigenetic regulation of HOTAIR and its target microRNA, miR-143, in advanced CML.Patients and methods: We first isolated bone marrow mononuclear cells from 70 patients with different phases of CML and from healthy donors as normal control; we also cultured K562 and KCL22 cells, treated with demethylation drug; MTT assay, flow cytometry, quantitative real-time polymerase chain reaction (qPCR), methylation-specific polymerase chain reaction (MSP), Western blot, luciferase assay, RNA pull-down assay and RNA-binding protein immunoprecipitation (RIP) assay were performed.Result: As measured by qPCR, HOTAIR expression in K562 cells, KCL22 cells, and samples from cases of advanced-stage CML increased with levels of several DNA methyltransferases and histone deacetylates, including DNMT1, DNMT3A, HDAC1, EZH2, and LSD1, and miR-143 levels were decreased and HOTAIR levels were increased. Treatment with 5-azacytidine, a DNA methylation inhibitor, decreased DNMT1, DNMT3A, HDAC1, EZH2, LSD1 mRNA, protein levels, and HOTAIR mRNA levels but increased miR-143 levels. HOTAIR knockdown and miR-143 overexpression both inhibited proliferation and promoted apoptosis in KCL22 and K562 cells through the PI3K/AKT pathway. RNA pull-down, mass spectrometry, and RIP assays showed that HOTAIR interacted with EZH2 and LSD1. A dual-luciferase assay demonstrated that HOTAIR interacted with miR-143.Conclusion: Our findings demonstrate the key epigenetic interactions of HOTAIR related to CML progression and suggest HOTAIR as a potential therapeutic target for advanced CML. Furthermore, our results support the use of demethylation drugs as a CML treatment strategy. Keywords: lncRNA HOTAIR, miR-143, epigenetic, PI3K/AKT, EZH2
