title: Synthesis and structure-activity relationships of N-6 substituted analogues of 9-hydroxy-4-phenylpyrrolo[3,4-c]carbazole-1,3(2H,6H)-diones as inhibitors of Wee1 and Chk1 checkpoint kinases.
abstract: A series of N-6 substituted 9-hydroxy-4-phenylpyrrolo[3,4-c]carbazole-1,3(2H,6H)-diones were prepared from N-substituted (5-methoxyphenyl)ethenylindoles. The target compounds were tested for their ability to inhibit the G2/M cell cycle checkpoint kinases, Wee1 and Chk1. Analogues with neutral or cationic N-6 side chains were potent dual inhibitors. Acidic side chains provided potent (average IC(50) 0.057 microM) and selective (average ratio 223-fold) Wee1 inhibition. Co-crystal structures of inhibitors bound to Wee1 show that the pyrrolo[3,4-c]carbazole scaffold binds in the ATP-binding site, with N-6 substituents involved in H-bonding to conserved water molecules. HT-29 cells treated with doxorubicin and then target compounds demonstrate an active Cdc2/cyclin B complex, inhibition of the doxorubicin-induced phosphorylation of tyrosine 15 of Cdc2 and abrogation of the G2 checkpoint.
authors.affiliation: Auckland Cancer Society Research Centre, School of Medical Sciences, The University of Auckland, Private Bag 92019, Auckland 1020, New Zealand. j.smaill@auckland.ac.nz
authors.forename: Jeff B
authors.initials: JB
authors.lastname: Smaill
authors.forename: Edward N
authors.initials: EN
authors.lastname: Baker
authors.forename: R John
authors.initials: RJ
authors.lastname: Booth
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Bridges
authors.forename: James M
authors.initials: JM
authors.lastname: Dickson
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Dobrusin
authors.forename: Ivan
authors.initials: I
authors.lastname: Ivanovic
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Kraker
authors.forename: Ho H
authors.initials: HH
authors.lastname: Lee
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Lunney
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Ortwine
authors.forename: Brian D
authors.initials: BD
authors.lastname: Palmer
authors.forename: John
authors.initials: J
authors.lastname: Quin
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Squire
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Thompson
authors.forename: William A
authors.initials: WA
authors.lastname: Denny
mesh_terms: D002227:Carbazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors*; D019073:HT29 Cells; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors*; D047428:Protein Kinase Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D013329:Structure-Activity Relationship
chemical_list: D002227:Carbazoles; D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; D047428:Protein Kinase Inhibitors; D011505:Protein-Tyrosine Kinases; C499349:WEE1 protein, human