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CCT244747

CCT244747 : ATP competitive inhibitor of CHEK1

Structure

Information

  • CHEK1
  • ATP competitive
  • 30 - 1000 nM

In Vitro Validations

Uniprot ID: O14757
Target Class: Kinase
Target SubClass: CAMK
Potency: IC50
Potency Value: 7.7 nM
Potency Assay: Inhibition of recombinant full-length CHK1 kinase activity was measured in a microfluidic assay that monitored the separation of a fluorescently labelled, phosphorylated product peptide from the unphosphorylated substrate (5-FAM-KKKVSRSGLYRSPSMPENLNRPR-COOH).
PDB ID for probe-target interaction (3D structure): --
Structure-activity relationship: Structure-activity data for inhibition of CHK1 in vitro were determined using a recombinant, full-length CHK1 in a kinase activity assay that monitored the separation of a fluorescently labelled, phosphorylated product peptide from the unphosphorylated substrate and are described in doi: 10.1021/jm3012933. Structure-activity data for selectivity for inhibition of CHK1 versus CHK2 and CDK1 in vitro are also described.
Target aliases:
Serine/threonine-protein kinase Chk1, CHK1, CHEK1, ...

DOI Reference: 10.1158/1078-0432.CCR-12-1322

In Cell Validations

In Vivo Data

Off-Target Selectivity Assesments

Potency end-point : IC50 CHK2 >10,000 nM, CDK1 >10,000 nM
Potency assay (off target): Inhibition of recombinant, full-length CHK2 and CDK1 kinase activity was determined in a DELFIA assay measuring peptide substrate phosphorylation. Broad kinase activity screening was carried out using a radiometric assay format against 140 kinases, with CCT244747 tested at a single concentration of 1000 nM. 127 of the 140 kinases showed <50% inhibition at 1000 nM; RSK1/2, AMPK, BRSK1, IRAK1, TRKA were inhibited >80% at 1000 nM.
Probe Selectivity in Vitro:

We assessed binding/inhibition of eight cardiac ion channels (Millipore Ion Channel CardiacProfilerTM Panel). At 10,000 nM, the probe inhibited the following targets <25%: Nav1.5, hKv4.3/hKChIP2, hCav1.2, hKv1.5, hKCNQ1/hminK, hHCN4, and hKir2.1. HERG IC50 = 5000 nM. In a broad in vitro pharmacology screen of 80 non-family targets (Cerep), the probe inhibited 76 of the 80 proteins <80% at 10,000 nM,

Probe Selectivity in Cell:

CHK1 inhibition alone is not expected to be cytotoxic in HT29 and SW620 colon cancer cell lines. Therefore, the ratio of single agent cytotoxicity (GI50; SRB proliferation assay) to the on-target potency for CHK1 inhibition (IC50; G2 checkpoint abrogation) in these cells provides a measure of the compound cellular selectivity. HT29 cellular selectivity = 21-fold; SW620 cellular selectivity = 18-fold.

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SERP ratings and comments

SERP Ratings

In Cell Rating
In Model Organisms

SERP Comments:

The IC50 for the target kinase, CHK1, is 7.7 nM. The inhibitor was tested versus panel of 140 kinases and showed 50% inhibition against 127 of them and 80% inhibition against 5 at 1,000 nM; no IC50s for these off-target kinases were reported.

(last updated: 23 Oct 2016 )

SERP Ratings

In Cell Rating
In Model Organisms

SERP Comments:

In vivo pharmacokinetic (PK) studies show good oral availability, with a more extended half-life compared to iv dosing. Accumulation in tumors was measured. Efficacy of gemcitabine and irinotecan was enhanced in several tumour xenograft models, while CCT244747 was active as a single agent in MYCN-driven neuroblastoma (significant shrinkage after 7 days at 100 mg/kg oral administration). Activity is likely due to on-target activity, but 5 other kinases in a panel of 140 were inhibited >50% at 1 uM; at the high concentrations dosed (75-150 mg/kg PO), possible effects through the inhibition of additional targets can not be ruled out.

(last updated: 18 May 2017 )

SERP Ratings

In Cell Rating
In Model Organisms

SERP Comments:

CCT2444747 is a potent CHK1 inhibitor (IC50=7.7 nM) with high selectivity over CHK2 and CDK1 (IC50 >10 uM). Depending on the cell line, off-target antiproliferative effects can be seen at fairly low concentrations (e.g., HT29 620 nM; Calu6 330 nM; 21-35-fold window with respect to on-target effects). The compound exhibits >50% inhibition at 1 uM against RSK1, RSK2, AMPK, BRSK1, IRAK1 and TRKA; therefore, these kinases could be inhibited when the compound is dosed in mouse models at the higher 150 mg/kg dose (plasma Cmax likely to be >>1 uM; only 12 h data available for higher doses) . The compound is moderately bound to mouse plasma proteins (24% unbound) and has very high iv clearance (higher than liver blood flow when dosed at 10 mg/kg), yet has good oral exposure, suggesting saturation of metabolism and non-linear PK.

(last updated: 11 Sept 2017 )