ABSTRACT
Using structure-based drug design, we identified a novel series of 5,6-dihydroimidazolo[1,5-f]pteridine PLK1 inhibitors. Rational improvements to compounds of this class resulted in single-digit nanomolar enzyme and cellular activity against PLK1, and oral bioavailability. Compound 1 exhibits >7 fold induction of phosphorylated Histone H3 and is efficacious in an in vivo HT-29 tumor xenograft model.
Subject(s)
Cell Cycle Proteins/antagonists & inhibitors , Drug Design , Imidazoles/chemical synthesis , Protein Serine-Threonine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins/antagonists & inhibitors , Pteridines/chemical synthesis , Animals , Enzyme Activation/drug effects , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Female , HT29 Cells , Heterografts , Humans , Imidazoles/chemistry , Imidazoles/pharmacology , Mice , Molecular Structure , Pteridines/chemistry , Pteridines/pharmacology , Structure-Activity Relationship , Polo-Like Kinase 1ABSTRACT
Using structure-based drug design, we identified and optimized a novel series of pyrimidodiazepinone PLK1 inhibitors resulting in the selection of the development candidate TAK-960. TAK-960 is currently undergoing Phase I evaluation in adult patients with advanced solid malignancies.
Subject(s)
Azepines/chemistry , Azepines/pharmacology , Cell Cycle Proteins/antagonists & inhibitors , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins/antagonists & inhibitors , 4-Aminobenzoic Acid/chemistry , 4-Aminobenzoic Acid/pharmacokinetics , 4-Aminobenzoic Acid/pharmacology , Administration, Oral , Adult , Azepines/pharmacokinetics , Cell Line, Tumor , Drug Discovery , Humans , Protein Kinase Inhibitors/pharmacokinetics , Young Adult , Polo-Like Kinase 1ABSTRACT
Polo-like kinase 1 (PLK1) is a serine/threonine protein kinase involved in key processes during mitosis. Human PLK1 has been shown to be overexpressed in various human cancers, and elevated levels of PLK1 have been associated with poor prognosis, making it an attractive target for anticancer therapy. TAK-960 [4-[(9-cyclopentyl-7,7-difluoro-5-methyl-6-oxo-6,7,8,9-tetrahydro-5H-pyrimido[4,5-b][1,4]diazepin-2-yl)amino]-2-fluoro-5-methoxy-N-(1-methylpiperidin-4-yl) benzamide] is a novel, investigational, orally bioavailable, potent, and selective PLK1 inhibitor that has shown activity in several tumor cell lines, including those that express multidrug-resistant protein 1 (MDR1). Consistent with PLK1 inhibition, TAK-960 treatment caused accumulation of G(2)-M cells, aberrant polo mitosis morphology, and increased phosphorylation of histone H3 (pHH3) in vitro and in vivo. TAK-960 inhibited proliferation of multiple cancer cell lines, with mean EC(50) values ranging from 8.4 to 46.9 nmol/L, but not in nondividing normal cells (EC(50) >1,000 nmol/L). The mutation status of TP53 or KRAS and MDR1 expression did not correlate with the potency of TAK-960 in the cell lines tested. In animal models, oral administration of TAK-960 increased pHH3 in a dose-dependent manner and significantly inhibited the growth of HT-29 colorectal cancer xenografts. Treatment with once daily TAK-960 exhibited significant efficacy against multiple tumor xenografts, including an adriamycin/paclitaxel-resistant xenograft model and a disseminated leukemia model. TAK-960 has entered clinical evaluation in patients with advanced cancers.
Subject(s)
Azepines/pharmacology , Cell Cycle Proteins/antagonists & inhibitors , Neoplasms/drug therapy , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins/antagonists & inhibitors , 4-Aminobenzoic Acid/chemistry , 4-Aminobenzoic Acid/pharmacology , Administration, Oral , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Azepines/chemistry , Biological Availability , Cell Cycle Checkpoints/drug effects , Cell Cycle Proteins/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drugs, Investigational/chemistry , Drugs, Investigational/pharmacokinetics , Drugs, Investigational/pharmacology , Female , HT29 Cells , Histones/metabolism , Humans , K562 Cells , Mice , Mice, Inbred BALB C , Mice, Inbred NOD , Mice, Nude , Mice, SCID , Molecular Structure , Neoplasms/metabolism , Neoplasms/pathology , Phosphorylation/drug effects , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacokinetics , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins/metabolism , Xenograft Model Antitumor Assays , Polo-Like Kinase 1ABSTRACT
In order to elucidate the mechanism of cartilage degradation in osteoarthritis (OA), we established a cell assay system. Under the stimulation of all-trans retinoic acid (ATRA), the human chondrosarcoma cell line HCS-2/8 increased proteoglycan release from inactivated bovine nasal cartilage (BNC) and the results suggested the involvement of membrane-bound metalloproteinase(s). Therefore, we focused on the induction of a disintegrin and metalloproteinase (ADAM) superfamily upon ATRA stimulation. Of all ADAMs tested, only ADAM28 was induced by ATRA in HCS-2/8 cells and also in human primary chondrocytes. We found that transfection of ADAM28 or its alternatively spliced soluble form augmented proteoglycan release in the cell assay; however, a mutant soluble form in which a portion of the disintegrin domain was deleted did not have proteoglycan-releasing activity, implying the importance of the domain for enzyme localization and substrate recognition for cartilage degradation in OA.
Subject(s)
ADAM Proteins/metabolism , Chondrocytes/drug effects , Osteoarthritis/metabolism , Proteoglycans/metabolism , Tretinoin/pharmacology , ADAM Proteins/classification , ADAM Proteins/genetics , Alternative Splicing , Animals , Biological Assay , COS Cells , Cattle , Cell Line , Chlorocebus aethiops , Chondrocytes/enzymology , Humans , Metalloproteases/classification , Metalloproteases/metabolism , Osteoarthritis/enzymology , Phylogeny , TransfectionABSTRACT
BACKGROUND: Flat adenomas in the colon are associated with a relatively higher potential for malignancy. Distinct genes may be involved in the development of flat adenoma. The aim of this study was to profile gene expression changes in flat adenomas in the colon. METHODS: A genomewide expression analysis was carried out by using flat adenoma and adjacent normal mucosa in the colon to detect differences in gene expression. Because the right and left colon have different embryonic origins, each sample was classified according to its location, and the gene expression levels between flat adenoma and adjacent normal mucosa were also compared among samples derived from the right or left colon. RESULTS: A total of 180 genes were differentially expressed between flat adenoma and normal mucosa in the colon, including matrix metalloproteinase 7 (MMP7), cadherin 3 (CDH3), S100P, and dual oxidase 2 (DUOX2). In addition, a total of 89 and 49 genes were differentially expressed between flat adenoma and normal mucosa among the samples from the right and left colon, respectively. Subsequent quantitative real-time reverse transcriptase-polymerase chain reaction supported the reliability of the expression analysis. Immunohistochemical analysis confirmed differential CDH3 and MMP7 protein expression. CONCLUSIONS: This is the first report characterizing the genes differentially expressed in flat adenomas using a microarray analysis. Considerable differences in the gene expression profiles of flat adenomas also exist between the right and left colon. These data should lead to new insights into the pathogenesis of flat adenomas in the colon as well as to new therapeutic strategies.
