ABSTRACT
Pyrrolidine, pyrrolidinone, carbocyclic, and acyclic groups were used as isosteric proline replacements in a series of insulin-like growth factor I receptor kinase/insulin receptor kinase inhibitors. Examples that were similar in potency to proline-containing reference compounds were shown to project a key fluoropyridine amide into a common space, while less potent compounds were not able to do so for reasons of stereochemistry or structural rigidity.
Subject(s)
Proline/chemistry , Protein Kinase Inhibitors/chemistry , Receptor, IGF Type 1/antagonists & inhibitors , Receptor, Insulin/antagonists & inhibitors , Triazines/chemistry , Models, Molecular , Protein Kinase Inhibitors/pharmacology , Triazines/pharmacologyABSTRACT
The SAR of PXR transactivation by 3-(benzimidazol-2-yl)-pyridine-2-one based ATP competitive inhibitors of Insulin-like Growth Factor 1 Receptor kinase (IGF-1R) is discussed. Compounds without PXR transactivation, with in vivo antitumor activity, reduced protein binding and improved oral exposure are presented.
Subject(s)
Antineoplastic Agents/chemistry , Benzimidazoles/chemistry , Protein Kinase Inhibitors/chemistry , Receptor, IGF Type 1/antagonists & inhibitors , Receptors, Steroid/genetics , Transcriptional Activation , Administration, Oral , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacokinetics , Benzimidazoles/chemical synthesis , Benzimidazoles/pharmacokinetics , Cell Line, Tumor , Cytochrome P-450 CYP3A/genetics , Cytochrome P-450 CYP3A/metabolism , Humans , Mice , Mice, Nude , Pregnane X Receptor , Protein Binding , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Receptor, IGF Type 1/metabolism , Receptors, Steroid/metabolism , Structure-Activity Relationship , Xenograft Model Antitumor AssaysABSTRACT
The insulin-like growth factor I receptor (IGF-IR) is a transmembrane tyrosine kinase that is essential to growth and development and also thought to provide a survival signal for the maintenance of the transformed phenotype. There has been increasing interest in further understanding the role of IGF-I signaling in cancer and in developing receptor antagonists for therapeutic application. We describe herein a novel animal model that involves transgenic expression of a fusion receptor that is constitutively activated by homodimerization. Transgenic mice that expressed the activated receptor showed aberrant development of the mammary glands and developed salivary and mammary adenocarcinomas as early as 8 weeks of age. Xenograft tumors and a cell line were derived from the transgenic animals and are sensitive to inhibition by a novel small-molecule inhibitor of the IGF-IR kinase. This new model should provide new opportunities for further understanding how aberrant IGF-IR signaling leads to tumorigenesis and for optimizing novel antagonists of the receptor kinase.
