DDX5-targeting fully human monoclonal autoantibody inhibits proliferation and promotes differentiation of acute promyelocytic leukemia cells by increasing ROS production

• Published in: Cell death & disease Vol. 11; no. 7; p. 552
• Main Authors: Wu, Jing, You, Yan-Qiu, Ma, Yan-Xiu, Kang, Yan-Hua, Wu, Tian, Wu, Xiang-Ji, Hu, Xiao-Xiao, Meng, Qiao-Hong, Huang, Yin, Zhang, Na, Pan, Xiao-Ben
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 20.07.2020; Springer Nature B.V
• Subjects: 631/67/1059; 692/699; Acetylcysteine - pharmacology; Acute myeloid leukemia; Acute promyeloid leukemia; Animals; Antibodies; Antibodies, Monoclonal - pharmacology; Autoantibodies; Biochemistry; Biomedical and Life Sciences; Cell Biology; Cell Culture; Cell Cycle Checkpoints - drug effects; Cell Cycle Checkpoints - genetics; Cell differentiation; Cell Differentiation - drug effects; Cell growth; Cell Line, Tumor; Cell proliferation; Cell Proliferation - drug effects; Chemotherapy; Cytotoxicity; DEAD-box RNA Helicases - antagonists & inhibitors; DEAD-box RNA Helicases - genetics; DEAD-box RNA Helicases - metabolism; Down-Regulation - drug effects; Down-Regulation - genetics; G1 phase; Gene Expression Regulation, Leukemic - drug effects; Gene Silencing - drug effects; Humans; Immunology; Leukemia; Leukemia, Promyelocytic, Acute - genetics; Leukemia, Promyelocytic, Acute - metabolism; Leukemia, Promyelocytic, Acute - pathology; Life Sciences; Male; Mice, Inbred BALB C; Myeloid leukemia; Neutrophils - drug effects; Neutrophils - metabolism; Promyeloid leukemia; Reactive oxygen species; Reactive Oxygen Species - metabolism; siRNA
• ISSN: 2041-4889; 2041-4889
• DOI: 10.1038/s41419-020-02759-5

Acute promyelocytic leukemia (APL) therapy involves the compounds cytotoxic to both malignant tumor and normal cells. Relapsed APL is resistant to subsequent chemotherapy. Novel agents are in need to kill APL cells selectively with minimal toxicity. DDX5 has been recognized to be a novel target to suppress acute myeloid leukemia (AML). However, the role of DDX5 remains elusive in APL. Here a DDX5-targeting fully human monoclonal autoantibody named after 2F5 was prepared. It is demonstrated that 2F5 selectively inhibited APL cell proliferation without toxicity to normal neutrophil and tissues. Moreover, 2F5 was confirmed to induce G0/G1 phase arrest in APL cells, and promote APL cell differentiation combined with decreased DDX5 expression and increased reactive oxygen species (ROS) production. Knockdown of DDX5 by siRNA also inhibited proliferation, promoted cell differentiation and enhanced ROS production in APL cells. However, the ROS inhibitor reversed the effects of 2F5 on DDX5 and ROS in APL cells. Thus, we conclude that DDX5-targeting 2F5 inhibits APL cell proliferation, and promotes cell differentiation via induction of ROS. 2F5 showed the therapeutic value of fully human monoclonal autoantibody in APL, which provides a novel and valid approach for treatment of relapse/refractory APL.