title: Antitumoral activity of allosteric inhibitors of protein kinase CK2.
abstract: BACKGROUND
  Due to its physiological role into promoting cell survival and its dysregulation in most cancer cells, protein kinase CK2 is a relevant physiopathological target for development of chemical inhibitors. We report the discovery of azonaphthalene derivatives, as a new family of highly specific CK2 inhibitors. First, we demonstrated that CK2 inhibition (IC50= 0.4 µM) was highly specific, reversible and non ATP-competitive. Small Angle X-ray Scattering experiments showed that this inhibition was due to large conformational change of CK2α upon binding of these inhibitors. We showed that several compounds of the family were cell-potent CK2 inhibitors promoting cell cycle arrest of human glioblastoma U373 cells. Finally, in vitro and in vivo assays showed that these compounds could decrease U373 cell tumor mass by 83 % emphasizing their efficacy against these apoptosis-resistant tumors. In contrast, Azonaphthalene derivatives inactive on CK2 activity showed no effect in colony formation and tumor regression assays. These findings illustrate the emergence of nonclassical CK2 inhibitors and provide exciting opportunities for the development of novel allosteric CK2 inhibitors.
  
  
  BACKGROUND
  CK2 is an emerging therapeutic target and ATP-competitive inhibitors have been identiﬁed. CK2 is endowed with specific structural features providing alternative strategies for inhibition.
  
  
  RESULTS
  Azonaphthalene compounds are allosteric CK2 inhibitors showing antitumor activity.
  
  
  CONCLUSIONS
  CK2 may be targeted allosterically.
  
  
  CONCLUSIONS
  These inhibitors provide a foundation for a new paradigm for specific CK2 inhibition.
authors.affiliation: From INSERM, U1036, Biology of Cancer and Infection, Grenoble, F-38054, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Moucadel
authors.forename: Renaud
authors.initials: R
authors.lastname: Prudent
authors.forename: Céline F
authors.initials: CF
authors.lastname: Sautel
authors.forename: Florence
authors.initials: F
authors.lastname: Teillet
authors.forename: Caroline
authors.initials: C
authors.lastname: Barette
authors.forename: Laurence
authors.initials: L
authors.lastname: Lafanechere
authors.forename: Veronique
authors.initials: V
authors.lastname: Receveur-Brechot
authors.forename: Claude
authors.initials: C
authors.lastname: Cochet
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001391:Azo Compounds / Q000494:pharmacology*; D047390:Casein Kinase II / Q000037:antagonists & inhibitors*; D059447:Cell Cycle Checkpoints / Q000187:drug effects*; D045744:Cell Line, Tumor; D002470:Cell Survival; D005260:Female; D006367:HeLa Cells; D057166:High-Throughput Screening Assays; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009281:Naphthalenes / Q000494:pharmacology*; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D001391:Azo Compounds; D009281:Naphthalenes; D047428:Protein Kinase Inhibitors; D047390:Casein Kinase II