Cdc7 kinase inhibitors: 5-heteroaryl-3-carboxamido-2-aryl pyrroles as potential antitumor agents. 1. Lead finding.

Cdc7 serine/threonine kinase is a key regulator of DNA synthesis in eukaryotic organisms. Cdc7 inhibition through siRNA or prototype small molecules causes p53 independent apoptosis in tumor cells while reversibly arresting cell cycle progression in primary fibroblasts. This implies that Cdc7 kinase could be considered a potential target for anticancer therapy. We previously reported that pyrrolopyridinones (e.g., 1) are potent and selective inhibitors of Cdc7 kinase, with good cellular potency and in vitro ADME properties but with suboptimal pharmacokinetic profiles. Here we report on a new chemical class of 5-heteroaryl-3-carboxamido-2-substituted pyrroles (1A) that offers advantages of chemistry diversification and synthetic simplification. This work led to the identification of compound 18, with biochemical data and ADME profile similar to those of compound 1 but characterized by superior efficacy in an in vivo model. Derivative 18 represents a new lead compound worthy of further investigation toward the ultimate goal of identifying a clinical candidate.

Cell division cycle 7 kinase inhibitors: 1H-pyrrolo[2,3-b]pyridines, synthesis and structure-activity relationships.

Cdc7 kinase has recently emerged as an attractive target for cancer therapy and low-molecular-weight inhibitors of Cdc7 kinase have been found to be effective in the inhibition of tumor growth in animal models. In this paper, we describe synthesis and structure-activity relationships of new 1H-pyrrolo[2,3-b]pyridine derivatives identified as inhibitors of Cdc7 kinase. Progress from (Z)-2-phenyl-5-(1H-pyrrolo[2,3-b]pyridin-3-ylmethylene)-3,5-dihydro-4H-imidazol-4-one (1) to [(Z)-2-(benzylamino)-5-(1H-pyrrolo[2,3-b]pyridin-3-ylmethylene)-1,3-thiazol-4(5H)-one] (42), a potent ATP mimetic inhibitor of Cdc7 kinase with IC(50) value of 7 nM, is also reported.

First Cdc7 kinase inhibitors: pyrrolopyridinones as potent and orally active antitumor agents. 2. Lead discovery.

Cdc7 kinase is a key regulator of the S-phase of the cell cycle, known to promote the activation of DNA replication origins in eukaryotic organisms. Cdc7 inhibition can cause tumor-cell death in a p53-independent manner, supporting the rationale for developing Cdc7 inhibitors for the treatment of cancer. In this paper, we conclude the structure-activity relationships study of the 2-heteroaryl-pyrrolopyridinone class of compounds that display potent inhibitory activity against Cdc7 kinase. Furthermore, we also describe the discovery of 89S, [(S)-2-(2-aminopyrimidin-4-yl)-7-(2-fluoro-ethyl)-1,5,6,7-tetrahydropyrrolo[3,2-c]pyridin-4-one], as a potent ATP mimetic inhibitor of Cdc7. Compound 89S has a Ki value of 0.5 nM, inhibits cell proliferation of different tumor cell lines with an IC50 in the submicromolar range, and exhibits in vivo tumor growth inhibition of 68% in the A2780 xenograft model.

Cdc7 kinase inhibitors: pyrrolopyridinones as potential antitumor agents. 1. Synthesis and structure-activity relationships.

Cdc7 kinase is an essential protein that promotes DNA replication in eukaryotic organisms. Genetic evidence indicates that Cdc7 inhibition can cause selective tumor-cell death in a p53-independent manner, supporting the rationale for developing Cdc7 small-molecule inhibitors for the treatment of cancers. In this paper, the synthesis and structure-activity relationships of 2-heteroaryl-pyrrolopyridinones, the first potent Cdc7 kinase inhibitors, are described. Starting from 2-pyridin-4-yl-1,5,6,7-tetrahydro-pyrrolo[3,2-c]pyridin-4-one, progress toward a simple scaffold, tailored for Cdc7 inhibition, is reported.