ABSTRACT
Aniline 'headgroups' were synthesized and incorporated into an alkynyl thienopyrimidine series of EGFR and ErbB-2 inhibitors. Potent inhibition of enzyme activity and cellular proliferation was observed. In certain instances, protein binding was reduced and oral exposure was found to be somewhat improved relative to compounds containing the reference aniline.
Subject(s)
Aniline Compounds/chemical synthesis , ErbB Receptors/antagonists & inhibitors , Protein Kinase Inhibitors/chemical synthesis , Pyrimidines/chemical synthesis , Receptor, ErbB-2/antagonists & inhibitors , Administration, Oral , Aniline Compounds/administration & dosage , Aniline Compounds/pharmacology , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Evaluation, Preclinical/methods , ErbB Receptors/metabolism , Growth Inhibitors/administration & dosage , Growth Inhibitors/chemical synthesis , Growth Inhibitors/pharmacology , Humans , Mice , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/pharmacology , Pyrimidines/administration & dosage , Pyrimidines/pharmacology , Receptor, ErbB-2/metabolismABSTRACT
Two new series of potent and selective dual EGFR/ErbB-2 kinase inhibitors derived from novel thienopyrimidine cores have been identified. Isomeric thienopyrimidine cores were evaluated as isosteres for a 4-anilinoquinazoline core and several analogs containing the thieno[3,2-d]pyrimidine core showed anti-proliferative activity with IC(50) values less than 1 microM against human tumor cells in vitro.
Subject(s)
Antineoplastic Agents/pharmacology , Chemistry, Pharmaceutical/methods , ErbB Receptors/chemistry , Pyrimidines/chemistry , Receptor, ErbB-2/antagonists & inhibitors , Antineoplastic Agents/chemical synthesis , Cell Line, Tumor , Cell Proliferation , Drug Design , Drug Screening Assays, Antitumor , Enzyme Inhibitors/pharmacology , Humans , Inhibitory Concentration 50 , Lapatinib , Models, Chemical , Molecular Conformation , Quinazolines/pharmacologyABSTRACT
The discovery and development of a series of thiophenes as potent and selective inhibitors of PLK is described. Identification and characterization of 2, a useful in vitro PLK inhibitor tool compound, is also presented.
Subject(s)
Cell Cycle Proteins/antagonists & inhibitors , Chemistry, Pharmaceutical/methods , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins/antagonists & inhibitors , Thiophenes/antagonists & inhibitors , Animals , Cell Cycle , Cell Cycle Proteins/chemistry , Cell Line, Tumor , Cell Proliferation , Drug Design , Humans , Inhibitory Concentration 50 , Mice , Mitosis , Models, Chemical , Molecular Conformation , Protein Serine-Threonine Kinases/chemistry , Proto-Oncogene Proteins/chemistry , Thiophenes/chemistry , Polo-Like Kinase 1ABSTRACT
Polo-like kinase 1 (PLK1) plays key roles in the regulation of mitotic progression, including mitotic entry, spindle formation, chromosome segregation, and cytokinesis. PLK1 expression and activity are strongly linked to proliferating cells. Many studies have shown that PLK1 expression is elevated in a variety of tumors, and high expression often correlates with poor prognosis. Using a variety of methods, including small-molecule inhibition of PLK1 function and/or activity, apoptosis in cancer cell lines, cell cycle arrest in normal cell lines, and antitumor activity in vivo have been observed. In the present study, we have examined the in vitro biological activity of a novel and selective thiophene benzimidazole ATP-competitive inhibitor of PLK1 and PLK3 (5-(5,6-dimethoxy-1H-benzimidazol-1-yl)-3-{[2-(trifluoromethyl)-benzyl]oxy}thiophene-2-carboxamide, called compound 1). Compound 1 has low nanomolar activity against the PLK1 and PLK3 enzymes and potently inhibits the proliferation of a wide variety of tumor cell lines. In the lung adenocarcinoma cell line NCI-H460, compound 1 induces a transient G(2)-M arrest, mitotic spindle defects, and a multinucleate phenotype resulting in apoptosis, whereas normal human diploid fibroblasts arrest in G(2)-M and show little apoptosis. We also describe a cellular mechanistic assay that was developed to identify potent intracellular inhibitors of PLK1. In addition to its potential as a therapeutic agent for treating cancer, compound 1 is also a useful tool molecule for further investigation of the biological functions of PLK1 and PLK3.
