title: Identification of inhibitors of checkpoint kinase 1 through template screening.
abstract: Checkpoint kinase 1 (CHK1) is an oncology target of significant current interest. Inhibition of CHK1 abrogates DNA damage-induced cell cycle checkpoints and sensitizes p53 deficient cancer cells to genotoxic therapies. Using template screening, a fragment-based approach to small molecule hit generation, we have identified multiple CHK1 inhibitor scaffolds suitable for further optimization. The sequential combination of in silico low molecular weight template selection, a high concentration biochemical assay and hit validation through protein-ligand X-ray crystallography provided 13 template hits from an initial in silico screening library of ca. 15000 compounds. The use of appropriate counter-screening to rule out nonspecific aggregation by test compounds was essential for optimum performance of the high concentration bioassay. One low molecular weight, weakly active purine template hit was progressed by iterative structure-based design to give submicromolar pyrazolopyridines with good ligand efficiency and appropriate CHK1-mediated cellular activity in HT29 colon cancer cells.
authors: Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, 15 Cotswold Road, Sutton, Surrey SM2 5NG, UK.
authors: Thomas P
authors: TP
authors: Matthews
authors: Suki
authors: S
authors: Klair
authors: Samantha
authors: S
authors: Burns
authors: Kathy
authors: K
authors: Boxall
authors: Michael
authors: M
authors: Cherry
authors: Martin
authors: M
authors: Fisher
authors: Isaac M
authors: IM
authors: Westwood
authors: Michael I
authors: MI
authors: Walton
authors: Tatiana
authors: T
authors: McHardy
authors: Kwai-Ming J
authors: KM
authors: Cheung
authors: Rob
authors: R
authors: Van Montfort
authors: David
authors: D
authors: Williams
authors: G Wynne
authors: GW
authors: Aherne
authors: Michelle D
authors: MD
authors: Garrett
authors: John
authors: J
authors: Reader
authors: Ian
authors: I
authors: Collins
mesh_terms: D000071877:Checkpoint Kinase 1; D004353:Drug Evaluation, Preclinical; D019073:HT29 Cells; D006801:Humans; D006860:Hydrogen Bonding; D047428:Protein Kinase Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011494:Protein Kinases / Q000737:chemistry / Q000187:drug effects*; D013329:Structure-Activity Relationship
chemical_list: D047428:Protein Kinase Inhibitors; D011494:Protein Kinases; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1