Project title: Center of Excellence for Cancer Research at Taipei Veterans General Hospital phase II: Integrated approach to reduce cancer incidence and mortality Program title: Searching for biomarkers and therapy targets of tumor occurrence, progression, recurrence and drug resistance in lung cancer

Thiostrepton as an Inhibitor of Cancer Stem Cell Growth and a Potential Enhancer for Chemotherapy in Non-small Cell Lung Cancer

Tse-Hung Huang1,2,3,*, Alexander T. H. Wu4,*, Tai-Shan Cheng5,*, Kuan-Ting Lin6, Chia-Jou Lai7, Hao-Wen Hsieh8, Peter Mu-Hsin Chang9,10, Cheng-Wen Wu8,11, Chi-Ying F. Huang7,8,12,#, Kuan-Yu Chen13,#

黃澤宏，吳駿翃，鄭大山，林冠廷，賴佳柔，謝皓雯，張牧新，吳成文， 黃奇英，陳冠宇

1Department of Traditional Chinese Medicine, Chang Gung Memorial Hospital, Keelung., 2School of Traditional Chinese Medicine, Chang Gung University, Taoyuan., 3School of Nursing, National Taipei University of Nursing and Health Sciences, Taipei., 4The Ph.D. Program of Translational Medicine, College of Medicine, Taipei Medical University, Taipei., 5The Ph.D. Program for Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei., 6Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA., 7Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei., 8Institute of Clinical Medicine, National Yang-Ming University, Taipei., 9Department of Oncology, Taipei Veterans General Hospital, Taipei., 10Faculty of Medicine, National Yang Ming University, Taipei., 11Institute of Biomedical Sciences, Academia Sinica, Taipei., 12Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung., 13Division of Pulmonary Medicine, Department of Internal Medicine, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan.

The presence of cancer stem-like cells (CSCs) has contributed to treatment resistance and disease recurrence. Thus, identifying agents that can selectively eliminate CSCs may lead to a more effective therapeutic strategy. Here, we used CSC-associated gene signatures to query Connectivity Map for identifying potential drug candidates that display the property to reverse the CSC gene signature. Thiostrepton, a natural cyclic oligopeptide antibiotic, was identified as the top candidate in this bioinformatics search. Thiostrepton’ inhibitory effects on CSC population have been further supported by the reduced expression of cancer stemness markers, including CD133, Nanog, and Oct4A, in non-small cell lung cancer (NSCLC) cell lines. In addition, metastasis-associated Src tyrosine kinase signaling, cell migration, and epithelial-to-mesenchymal transition (EMT) processes were all inhibited by thiostrepton treatment. Thiostrepton in combination with gemcitabine synergistically suppressed NSCLC cell growth. More importantly, thiostrepton suppressed NSCLC tumorigenesis in vivo. Mechanistically, thiostrepton treatment led to the increased level of tumor suppressor miR-98 and reduced stemness and EMT markers. Our study demonstrated that thiostrepton, an old drug identified in silico, is an inhibitor for CSC renewal and a potential enhancer for chemotherapy in NSCLC.