A Novobiocin Derivative, XN4, Inhibits the Proliferation of Chronic Myeloid Leukemia Cells by Inducing Oxidative DNA Damage

• Published in: PloS one 2015-04, Vol.10 (4), p.e0123314-e0123314
• Main Authors: Wu, Lixian, Chen, Xianling, Huang, Lisen, Tian, Jue, Ke, Fang, Xu, Jianhua, Chen, Yuanzhong, Zheng, Ming
• Format: Article
• Language: English
• Subjects: Acetylcysteine; Antigens, CD34 - genetics; Antigens, CD34 - metabolism; Apoptosis; Apoptosis - drug effects; Apoptosis - genetics; Bone marrow; Bromine compounds; Cancer genetics; Caspase; Caspase-3; Cell cycle; Cell Cycle - drug effects; Cell Cycle - genetics; Cell death; Cell Line, Tumor; Cell proliferation; Cell Proliferation - drug effects; Cell Proliferation - genetics; Cell Survival - drug effects; Cell Survival - genetics; Chronic myeloid leukemia; Cytometry; Damage; Deoxyribonucleic acid; DNA; DNA damage; DNA Damage - drug effects; DNA Damage - genetics; Flow Cytometry; Humans; Immunoblotting; Intracellular signalling; K562 Cells; Leukemia; Membrane Proteins - genetics; Membrane Proteins - metabolism; mRNA; Myeloid leukemia; NAD(P)H oxidase; NADPH Oxidase 4; NADPH Oxidase 5; NADPH Oxidases - genetics; NADPH Oxidases - metabolism; Novobiocin; Novobiocin - analogs & derivatives; Novobiocin - pharmacology; NOX4 protein; Oxidases; Oxygen; Poly(ADP-ribose) polymerase; Reactive oxygen species; Reactive Oxygen Species - metabolism; Real-Time Polymerase Chain Reaction; RNA; Stem cells
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0123314

XN4 might induce DNA damage and apoptotic cell death through reactive oxygen species (ROS). The inhibition of proliferation of K562 and K562/G01 cells was measured by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide). The mRNA levels of NADPH oxidase 1-5 (Nox1-5) genes were evaluated by qRT-PCR. The levels of extracellular reactive oxygen species (ROS), DNA damage, apoptosis, and cell cycle progression were examined by flow cytometry (FCM). Protein levels were analyzed by immunoblotting. XN4 significantly inhibited the proliferation of K562 and K562/G01 cells, with IC50 values of 3.75±0.07 µM and 2.63±0.43 µM, respectively. XN4 significantly increased the levels of Nox4 and Nox5 mRNA, stimulating the generation of intracellular ROS, inducing DNA damage and activating ATM-γ-H2AX signaling, which increased the number of cells in the S and G2/M phase of the cell cycle. Subsequently, XN4 induced apoptotic cell death by activating caspase-3 and PARP. Moreover, the above effects were all reversed by the ROS scavenger N-acetylcysteine (NAC). Additionally, XN4 can induce apoptosis in progenitor/stem cells isolated from CML patients' bone marrow. In conclusion, XN4-induced DNA damage and cell apoptosis in CML cells is mediated by the generation of ROS.