title: Englerin A Inhibits EWS-FLI1 DNA Binding in Ewing Sarcoma Cells.
abstract: High-throughput screening of extracts from plants, marine, and micro-organisms led to the identification of the extract from the plant Phyllanthus engleri as the most potent inhibitor of EWS-FLI1 induced luciferase reporter expression. Testing of compounds isolated from this extract in turn led to the identification of Englerin A (EA) as the active constituent of the extract. EA induced both necrosis and apoptosis in Ewing cells subsequent to a G2M accumulation of cells in the cell cycle. It also impacted clonogenic survival and anchorage-independent proliferation while also decreasing the proportion of chemotherapy-resistant cells identified by high ALDH activity. EA also caused a sustained increase in cytosolic calcium levels. EA appears to exert its effect on Ewing cells through a decrease in phosphorylation of EWS-FLI1 and its ability to bind DNA. This effect is mediated, at least in part, through a decrease in the levels of the calcium-dependent protein kinase PKC-βI after a transient up-regulation.
authors.affiliation: From the Molecular Targets Laboratory, NCI, National Institutes of Health.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Caropreso
authors.affiliation: From the Molecular Targets Laboratory, NCI, National Institutes of Health.
authors.forename: Emad
authors.initials: E
authors.lastname: Darvishi
authors.affiliation: Optical Microscopy and Analysis Laboratory, Leidos Biomedical Research, Inc., and.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Turbyville
authors.affiliation: From the Molecular Targets Laboratory, NCI, National Institutes of Health.
authors.forename: Ranjala
authors.initials: R
authors.lastname: Ratnayake
authors.affiliation: Center for Cancer and Cell Biology, Van Andel Institute, Grand Rapids, Michigan 49503, and Division of Hematology/Oncology, Helen DeVos Children's Hospital, Grand Rapids, Michigan 49503.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Grohar
authors.affiliation: From the Molecular Targets Laboratory, NCI, National Institutes of Health.
authors.forename: James B
authors.initials: JB
authors.lastname: McMahon
authors.affiliation: Basic Science Program, Leidos Biomedical Research, Inc., Molecular Targets Laboratory, Frederick National Laboratory, Frederick, Maryland 21702, woldemichaelg@mail.nih.gov.
authors.forename: Girma M
authors.initials: GM
authors.lastname: Woldemichael
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000235:genetics / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D001859:Bone Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D051789:Proto-Oncogene Protein c-fli-1 / Q000235:genetics / Q000378:metabolism*; D034802:RNA-Binding Protein EWS / Q000235:genetics / Q000378:metabolism*; D012512:Sarcoma, Ewing / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045789:Sesquiterpenes, Guaiane / Q000494:pharmacology*
chemical_list: D004273:DNA, Neoplasm; C106031:EWS-FLI fusion protein; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D045789:Sesquiterpenes, Guaiane; C534971:englerin A; D000444:Aldehyde Dehydrogenase
keywords: DNA-binding protein; EWS-FLI1; Englerin A; Ewings sarcoma; calcium; inhibition mechanism; inhibitor; transcription factor