title: The synthetic triterpenoid CDDO-Imidazolide suppresses STAT phosphorylation and induces apoptosis in myeloma and lung cancer cells.
abstract: OBJECTIVE
  Excessive activity of the transcription factors known as signal transducers and activators of transcription (STAT) contributes to the development and progression of malignancy in many organs. It is, therefore, important to develop new drugs to control the STATs, particularly their phosphorylation state, which is required for their transcriptional activity.
  
  
  METHODS
  Myeloma and lung cancer cells were treated with the new synthetic triterpenoid CDDO-Imidazolide, and STAT phosphorylation and apoptosis were evaluated by immunoblotting and fluorescence-activated cell sorting analysis.
  
  
  RESULTS
  We now report that CDDO-Imidazolide, previously shown to be a potent agent for control of inflammation, cell proliferation, and apoptosis, rapidly (within 30-60 minutes) and potently (at nanomolar levels) suppresses either constitutive or interleukin-6-induced STAT3 and STAT5 phosphorylation in human myeloma and lung cancer cells. Furthermore, in these cells, CDDO-Imidazolide also up-regulates critical inhibitors of STATs, such as suppressor of cytokine signaling-1 and SH2-containing phosphatase-1 (a tyrosine phosphatase). Moreover, gene array studies reported here show that CDDO-Imidazolide potently regulates the transcription of important genes that are targets of the STATs.
  
  
  CONCLUSIONS
  Our new data thus show that CDDO-Imidazolide is a potent suppressor of STAT signaling and provide a further mechanistic basis for future clinical use of this agent to control inflammation or cell proliferation.
authors.affiliation: Dartmouth Medical School and Dartmouth College, Hanover, New Hampshire, USA.
authors.forename: Karen
authors.initials: K
authors.lastname: Liby
authors.forename: Nga
authors.initials: N
authors.lastname: Voong
authors.forename: Charlotte R
authors.initials: CR
authors.lastname: Williams
authors.forename: Renee
authors.initials: R
authors.lastname: Risingsong
authors.forename: Darlene B
authors.initials: DB
authors.lastname: Royce
authors.forename: Tadashi
authors.initials: T
authors.lastname: Honda
authors.forename: Gordon W
authors.initials: GW
authors.lastname: Gribble
authors.forename: Michael B
authors.initials: MB
authors.lastname: Sporn
authors.forename: John J
authors.initials: JJ
authors.lastname: Letterio
mesh_terms: D017209:Apoptosis; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004797:Enzyme-Linked Immunosorbent Assay; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology*; D015151:Immunoblotting; D015850:Interleukin-6 / Q000378:metabolism; D008175:Lung Neoplasms / Q000378:metabolism*; D009101:Multiple Myeloma / Q000378:metabolism*; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D010766:Phosphorylation; D050791:STAT Transcription Factors / Q000378:metabolism*; D050799:STAT5 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D014158:Transcription, Genetic
chemical_list: C472829:1-(2-cyano-3,12-dioxooleana-1,9-dien-28-oyl) imidazole; D007093:Imidazoles; D015850:Interleukin-6; D050791:STAT Transcription Factors; D050799:STAT5 Transcription Factor; D009828:Oleanolic Acid