ABSTRACT
BACKGROUND: Bosutinib is a recently approved ABL inhibitor. In spite of the well-documented effectiveness of BCR-ABL inhibitors in treating chronic myeloid leukemia, development of resistance is a continuous clinical challenge. Transporters that facilitate drug uptake and efflux have been proposed as one potential source of resistance to tyrosine kinase inhibitor treatment. Our aim was to determine which carriers are responsible for bosutinib transport. METHODS: K562S cells overexpressing the drug transporters ABCB1, ABCG2, and SLC22A1 were generated, characterized and used in proliferation assay and intracellular uptake and retention assay (IUR). In vivo experiments were performed in nude mice injected with K562S, K562DOX cells (overexpressing ABCB1), and K562DOX silenced for ABCB1 (K562DOX/sh P-GP). RESULTS: The IUR assay using C-14 bosutinib showed that only ABCB1 was responsible for active bosutinib transport. K562DOX cells showed the lowest intracellular level of bosutinib, while K562DOX cells treated with the ABCB1 inhibitor verapamil showed intracellular bosutinib levels comparable with parental K562S. Proliferation assays demonstrated that K562DOX are resistant to bosutinib treatment while verapamil is able to restore the sensitivity to the drug. Nude mice injected with K562DOX and treated with bosutinib showed very limited response and quickly relapsed after stopping treatment while K562S as well as K562DOX/sh P-GP remained tumor-free. CONCLUSIONS: Our data suggest that the analysis of ABCB1 expression levels might help determine treatment options for patients exhibiting resistance to bosutinib.
Subject(s)
Aniline Compounds/therapeutic use , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Nitriles/therapeutic use , Quinolines/therapeutic use , ATP Binding Cassette Transporter, Subfamily B/drug effects , Aniline Compounds/administration & dosage , Aniline Compounds/metabolism , Animals , Cell Line, Tumor , Cell Proliferation , Female , Humans , In Vitro Techniques , Mice , Mice, Nude , Microscopy, Confocal , Nitriles/administration & dosage , Nitriles/metabolism , Quinolines/administration & dosage , Quinolines/metabolism , TransfectionABSTRACT
Src-null mice have higher bone mass because of decreased bone resorption and increased bone formation, whereas Abl-null mice are osteopenic, because of decreased bone formation. Compound I, a potent inhibitor of Src in an isolated enzyme assay (IC(50) 0.55 nM) and a Src-dependent cell growth assay, with lower activity on equivalent Abl-based assays, potently, but biphasically, accelerated differentiation of human mesenchymal stem cells to an osteoblast phenotype (1-10 nM). Compound I (≥0.1 nM) also activated osteoblasts and induced bone formation in isolated neonatal mouse calvariae. Compound I required higher concentrations (100 nM) to inhibit differentiation and activity of osteoclasts. Transcriptional profiling (TxP) of calvaria treated with 1 µM compound I revealed down-regulation of osteoclastic genes and up-regulation of matrix genes and genes associated with the osteoblast phenotype, confirming compound I's dual effects on bone resorption and formation. In addition, calvarial TxP implicated calcitonin-related polypeptide, ß (ß-CGRP) as a potential mediator of compound I's osteogenic effect. In vivo, compound I (1 mg/kg s.c.) increased vertebral trabecular bone volume 21% (microcomputed tomography) in intact female mice. Increased trabecular volume was also detected histologically in a separate bone, the femur, particularly in the secondary spongiosa (100% increase), which underwent a 171% increase in bone formation rate, a 73% increase in mineralizing surface, and a 59% increase in mineral apposition rate. Similar effects were observed in ovariectomized mice with established osteopenia. We conclude that the Src inhibitor compound I is osteogenic, presumably because of its potent stimulation of osteoblast differentiation and activation, possibly mediated by ß-CGRP.
Subject(s)
Osteogenesis/drug effects , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-abl/antagonists & inhibitors , src-Family Kinases/antagonists & inhibitors , Amino Acid Sequence , Animals , Cell Differentiation , Gene Expression Profiling , Humans , Mice , Mice, Inbred C57BL , Molecular Sequence Data , Osteoblasts/cytology , Osteoblasts/drug effects , Osteoclasts/cytology , Osteoclasts/drug effectsABSTRACT
An extension of our previously reported series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. Addition of a second methyl group to the tether provided analogs that show increased potency in binding as well as cell-proliferation assays and, more importantly, are stable toward microsomes. We wish to disclose the discovery of a macrocycle which showed impressive biomarker activity 24-h post dosing and which demonstrated prolonged exposure in tumors. When studied in a lung cancer xenograft model, the compound demonstrated significant tumor size reduction.
Subject(s)
Antineoplastic Agents/chemistry , Benzamides/chemistry , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Lung Neoplasms/drug therapy , Macrocyclic Compounds/chemistry , Administration, Oral , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/therapeutic use , Benzamides/pharmacokinetics , Benzamides/therapeutic use , Binding Sites , Biomarkers/metabolism , Drug Evaluation, Preclinical , HSP90 Heat-Shock Proteins/metabolism , Humans , Mice , Mice, Nude , Microsomes, Liver/metabolism , Protein Structure, Tertiary , Rats , Transplantation, HeterologousABSTRACT
A novel series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. In continuation of our research, heterocycle-containing tethers were explored with the intent to further improve potency and minimize hERG liabilities. This effort culminated in the discovery of compound 10, which efficiently suppressed proliferation of HCT116 and U87 cells. This compound showed prolonged Hsp90-inhibitory activity at least 24h post-administration consistent with elevated and prolonged exposure in the tumor. When studied in a xenograft model, the compound demonstrated significant suppression of tumor growth.
Subject(s)
Amines/chemical synthesis , Benzamides/chemical synthesis , Biomarkers, Tumor , Drug Discovery , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Macrocyclic Compounds/chemical synthesis , Macrocyclic Compounds/pharmacology , Amines/chemistry , Amines/pharmacology , Animals , Benzamides/chemistry , Benzamides/pharmacology , Benzoquinones/chemical synthesis , Benzoquinones/chemistry , Benzoquinones/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Inhibitory Concentration 50 , Lactams, Macrocyclic/chemical synthesis , Lactams, Macrocyclic/chemistry , Lactams, Macrocyclic/pharmacology , Macrocyclic Compounds/chemistry , Mice , Models, Molecular , Molecular Structure , Neoplasms/drug therapy , Xenograft Model Antitumor AssaysABSTRACT
A novel series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. In continuation of our research in this area, macrocyclic amides and lactams were explored to reduce the risk of hERG liabilities. This effort culminated in the discovery of compound 38, which showed a favorable in vitro profile, and efficiently suppressed proliferation of several relevant cell lines. This compound showed prolonged Hsp90-inhibitory activity at least 24 h post-administration, consistent with elevated and prolonged exposure in the tumor.
Subject(s)
Antineoplastic Agents/pharmacology , Biomarkers/metabolism , Drug Design , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Lactams, Macrocyclic/chemical synthesis , Lactams, Macrocyclic/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Crystallography, X-Ray , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/chemistry , Fluorescent Dyes/pharmacology , Humans , Inhibitory Concentration 50 , Lactams, Macrocyclic/chemistry , Models, Molecular , Molecular Structure , ortho-Aminobenzoates/chemical synthesis , ortho-Aminobenzoates/chemistry , ortho-Aminobenzoates/pharmacologyABSTRACT
A novel series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. A basic nitrogen within the tether linking the aniline nitrogen atom to a tetrahydroindolone moiety allowed access to compounds with good physical properties. Important structure-activity relationship information was obtained from this series which led to the discovery of a soluble and stable compound which is potent in an Hsp90 binding and cell-proliferation assay.
Subject(s)
Antineoplastic Agents/chemistry , Benzamides/chemistry , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Benzamides/chemical synthesis , Benzamides/pharmacology , Binding Sites , Cell Line, Tumor , Cell Proliferation , Computer Simulation , Crystallography, X-Ray , Drug Design , HSP90 Heat-Shock Proteins/metabolism , Humans , Protein Binding , Structure-Activity RelationshipABSTRACT
Cancer cells are exposed to external and internal stresses by virtue of their unrestrained growth, hostile microenvironment, and increased mutation rate. These stresses impose a burden on protein folding and degradation pathways and suggest a route for therapeutic intervention in cancer. Proteasome and Hsp90 inhibitors are in clinical trials and a 20S proteasome inhibitor, Velcade, is an approved drug. Other points of intervention in the folding and degradation pathway may therefore be of interest. We describe a simple screen for inhibitors of protein synthesis, folding, and proteasomal degradation pathways in this paper. The molecular chaperone-dependent client v-Src was fused to firefly luciferase and expressed in HCT-116 colorectal tumor cells. Both luciferase and protein tyrosine kinase activity were preserved in cells expressing this fusion construct. Exposing these cells to the Hsp90 inhibitor geldanamycin caused a rapid reduction of luciferase and kinase activities and depletion of detergent-soluble v-Src::luciferase fusion protein. Hsp70 knockdown reduced v-Src::luciferase activity and, when combined with geldanamycin, caused a buildup of v-Src::luciferase and ubiquitinated proteins in a detergent-insoluble fraction. Proteasome inhibitors also decreased luciferase activity and caused a buildup of phosphotyrosine-containing proteins in a detergent-insoluble fraction. Protein synthesis inhibitors also reduced luciferase activity, but had less of an effect on phosphotyrosine levels. In contrast, certain histone deacetylase inhibitors increased luciferase and phosphotyrosine activity. A mass screen led to the identification of Hsp90 inhibitors, ubiquitin pathway inhibitors, inhibitors of Hsp70/Hsp40-mediated refolding, and protein synthesis inhibitors. The largest group of compounds identified in the screen increased luciferase activity, and some of these increase v-Src levels and activity. When used in conjunction with appropriate secondary assays, this screen is a powerful cell-based tool for studying compounds that affect protein synthesis, folding, and degradation.
Subject(s)
Enzyme Inhibitors/pharmacology , Histone Deacetylase Inhibitors/pharmacology , Molecular Chaperones/antagonists & inhibitors , Proteasome Inhibitors , Protein Folding/drug effects , Protein Synthesis Inhibitors/pharmacology , Benzoquinones/pharmacology , Cell Line, Tumor , Drug Evaluation, Preclinical , HSP40 Heat-Shock Proteins/antagonists & inhibitors , HSP40 Heat-Shock Proteins/metabolism , HSP70 Heat-Shock Proteins/antagonists & inhibitors , HSP70 Heat-Shock Proteins/genetics , HSP70 Heat-Shock Proteins/metabolism , HSP90 Heat-Shock Proteins/antagonists & inhibitors , HSP90 Heat-Shock Proteins/genetics , HSP90 Heat-Shock Proteins/metabolism , Histone Deacetylases/chemistry , Histone Deacetylases/pharmacology , Humans , Lactams, Macrocyclic/pharmacology , Luciferases, Firefly/genetics , Luciferases, Firefly/metabolism , Oncogene Protein pp60(v-src)/chemistry , Oncogene Protein pp60(v-src)/genetics , Oncogene Protein pp60(v-src)/metabolism , Proteasome Endopeptidase Complex/metabolism , RNA Interference , RNA, Small Interfering , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Ubiquitin/antagonists & inhibitors , Ubiquitin/metabolismABSTRACT
Bosutinib (SKI-606) is an orally active Src and Abl kinase inhibitor presently in Phase III trials for treatment of chronic myelogenous leukaemia (CML), and in Phase II trials for treatment of breast cancer. Bosutinib is a potent antiproliferative and proapoptotic agent in CML cells and inhibits Bcr-Abl mediated signalling at nanomolar concentrations. Short-term administration of bosutinib causes regression of K562 and KU812 CML tumour xenografts. BaF3 murine myeloid cells expressing wild-type Bcr-Abl are sensitive to bosutinib treatment, as are BaF3 cells expressing many imatinib-resistant forms of Bcr-Abl. Recent studies indicate that bosutinib is active against a broader spectrum of kinases than originally believed. These additional inhibitory activities have interesting possibilities for further clinical development. This review will focus on preclinical studies supporting the clinical development of bosutinib for treatment of CML, with a discussion on the broader potential of this agent in other oncology indications.
Subject(s)
Aniline Compounds/therapeutic use , Antineoplastic Agents/therapeutic use , Enzyme Inhibitors/therapeutic use , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Nitriles/therapeutic use , Quinolines/therapeutic use , src-Family Kinases/therapeutic use , Aniline Compounds/chemistry , Animals , Cell Communication , Cell Line, Tumor , Clinical Trials as Topic , Cyclic N-Oxides/pharmacology , Drug Resistance, Neoplasm , Humans , Mice , Neoplasm Transplantation , Nitriles/chemistry , Protein Kinase Inhibitors/pharmacology , Quinolines/chemistry , Quinolines/pharmacology , Transplantation, Heterologous , src-Family Kinases/chemistryABSTRACT
The 7-alkene-3-quinolinecarbonitrile 20, a potent inhibitor of Src enzymatic and cellular activity with IC(50) values of 2.1 and 58 nM, respectively, had comparable efficacy to bosutinib in a colon tumor xenograft study.
Subject(s)
Antineoplastic Agents/chemistry , Protein Kinase Inhibitors/chemistry , Quinolines/chemistry , src-Family Kinases/antagonists & inhibitors , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Humans , Mice , Mice, Nude , Microsomes/metabolism , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Quinolines/chemical synthesis , Quinolines/pharmacology , Xenograft Model Antitumor Assays , src-Family Kinases/metabolismABSTRACT
In the current study, we have examined the efficacy of a Src/Abl kinase inhibitor SKI-606 (Bosutinib) for its effect on prostate cancer growth and skeletal metastasis. Treatment of highly invasive human prostate cancer cells PC-3 and DU-145 with different doses of SKI-606 decreased Src activation, cell proliferation, migration, and invasion as determined by Matrigel Boyden chamber invasion assay. For in vivo studies, PC-3 cells were inoculated through s.c. or i.t. route into male BALB/c nu/nu or Fox Chase severe combined immunodeficient mice, respectively. Experimental animals treated with SKI-606 developed tumors of a significantly smaller volume and a significant decrease (50%) in experimental skeletal lesion area. A marked increase (32%) in bone volume to tumor volume ratio was also seen by micro-computed tomography analysis of tibias from control and experimental groups of animals. Western blot analysis showed the ability of SKI-606 to significantly decrease the phosphorylation of signaling molecules (AKT, mitogen-activated protein kinase, focal adhesion kinase) and the expression of tumor progression-associated genes uPAR, MMP-2, MMP-9, N-cadherin, fibronectin, BMP-2 (bone morphogenetic protein 2), BMP-6 (bone morphogenetic protein 6), IL-8 (interleukin 8), and TGF-beta (transforming growth factor beta) in prostate cancer cells. SKI-606 is currently in clinical trials for breast cancer and chronic myelogenous leukemia. Results from these studies provide convincing evidence for evaluating its efficacy in prostate cancer patients.
Subject(s)
Aniline Compounds/therapeutic use , Bone Neoplasms/secondary , Carcinoma/drug therapy , Cell Proliferation/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Nitriles/therapeutic use , Prostatic Neoplasms/drug therapy , Quinolines/therapeutic use , Aniline Compounds/pharmacology , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Bone Neoplasms/genetics , Carcinoma/genetics , Carcinoma/pathology , Cell Line, Tumor , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Mice, SCID , Neoplasm Invasiveness , Neoplasm Metastasis , Nitriles/pharmacology , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Quinolines/pharmacology , Tumor Burden/drug effects , Tumor Burden/genetics , Xenograft Model Antitumor AssaysABSTRACT
Src kinase signaling has been implicated in multiple mechanisms of ischemic injury, including vascular endothelial growth factor (VEGF)-mediated vascular permeability that leads to vasogenic edema, a major clinical complication in stroke and brain trauma. Here we report the effects of two novel Src kinase inhibitors, 4-[(2,4-dichloro-5-methoxyphenyl)amino]-6-methoxy-7-[3-(4-methyl-1-piperazinyl)propoxy]-3-quinolinecarbonitrile (SKI-606) and 4-[(2,4-dichloro-5-methoxyphenyl)amino]-6-methoxy-7-[4-(4-methypiperazin-1-yl)but-1-ynyl]-3-quinolinecarbonitrile (SKS-927), on ischemia-induced brain infarction and short- and long-term neurological deficits. Two well established transient [transient middle cerebral artery occlusion (tMCAO)] and permanent [permanent middle cerebral artery occlusion (pMCAO)] focal ischemia models in the rat were used with drug treatments initiated up to 6 h after onset of stroke to mimic the clinical scenario. Brain penetration of Src inhibitors, their effect on blood-brain barrier integrity and VEGF signaling in human endothelial cells were also evaluated. Our results demonstrate that both agents potently block VEGF-mediated signaling in human endothelial cells, penetrate rat brain upon systemic administration, and inhibit postischemic Src activation and vascular leakage. Treatment with SKI-606 or SKS-927 (at the doses of 3-30 mg/kg i.v.) resulted in a dose-dependent reduction in infarct volume and robust protection from neurological impairments even when the therapy was initiated up to 4- to 6-h after tMCAO. Src blockade after pMCAO resulted in accelerated improvement in recovery from motor, sensory, and reflex deficits during a long-term (3 weeks) testing period poststroke. These data demonstrate that the novel Src kinase inhibitors provide effective treatment against ischemic conditions within a clinically relevant therapeutic window and may constitute a viable therapy for acute stroke.
Subject(s)
Aniline Compounds/therapeutic use , Brain Ischemia/drug therapy , Neuroprotective Agents/therapeutic use , Nitriles/therapeutic use , Piperazines/therapeutic use , Protein Kinase Inhibitors/therapeutic use , Quinolines/therapeutic use , src-Family Kinases/antagonists & inhibitors , Aniline Compounds/administration & dosage , Aniline Compounds/chemistry , Aniline Compounds/pharmacokinetics , Animals , Blood Platelets/drug effects , Blood Platelets/enzymology , Brain/drug effects , Brain/enzymology , Brain/metabolism , Brain Ischemia/enzymology , Capillary Permeability , Cells, Cultured , Disease Models, Animal , Dose-Response Relationship, Drug , Endothelial Cells/drug effects , Endothelial Cells/enzymology , Flow Cytometry , Humans , Injections, Intravenous , Male , Molecular Structure , Neuroprotective Agents/administration & dosage , Neuroprotective Agents/chemistry , Neuroprotective Agents/pharmacokinetics , Neuropsychological Tests , Nitriles/administration & dosage , Nitriles/chemistry , Nitriles/pharmacokinetics , Piperazines/administration & dosage , Piperazines/chemistry , Piperazines/pharmacokinetics , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacokinetics , Quinolines/administration & dosage , Quinolines/chemistry , Quinolines/pharmacokinetics , Rats , Rats, Wistar , Time FactorsABSTRACT
A series of 4-anilino-7-pyridyl-3-quinolinecarbonitriles was prepared as Src kinase inhibitors. A systematic SAR study of substitutions on both the pyridine ring and the 3-quinolinecarbonitrile core established the requirements for optimal activity. The lead compound, 17, showed potent activity in both the Src enzyme assay and cell assays, and demonstrated in vivo anti-tumor activity in a xenograft model.
Subject(s)
Aminoquinolines/chemistry , Aniline Compounds/chemistry , Antineoplastic Agents/chemistry , Protein Kinase Inhibitors/chemistry , Quinolines/chemistry , src-Family Kinases/antagonists & inhibitors , Aminoquinolines/chemical synthesis , Aminoquinolines/pharmacology , Aniline Compounds/chemical synthesis , Aniline Compounds/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Humans , Mice , Mice, Nude , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Quinolines/chemical synthesis , Quinolines/pharmacology , Rats , Structure-Activity Relationship , Xenograft Model Antitumor Assays , src-Family Kinases/metabolismABSTRACT
Recently, Src tyrosine kinase has emerged as an attractive target for anticancer therapy, and Src is overexpressed in pancreatic cancer. The purpose of the study was to investigate the in vivo efficacy and pharmacodynamic effects of bosutinib (SKI-606), a Src/Abl inhibitor, using a panel of human pancreatic tumor xenografts. Surgically resected human pancreatic tumors were implanted into female nude mice and randomized to bosutinib versus control. Src and other pathways were analyzed by Western Blot, IHC, and Affymetrix U133 Plus 2.0 gene arrays. Of 15 patient tumors, 3 patient tumors were found to be sensitive to bosutinib, defined as tumor growth of <45% than that of control tumors. There were no definite differences between sensitive and resistant tumors in the baseline Src kinase pathway protein expression assessed by Western Blot. Caveolin-1 expression, as assessed by reverse transcription-PCR and immunohistochemistry, was frequently higher in sensitive cases. In sensitive tumors, bosutinib resulted in increased apoptosis. Phosphorylation of key signaling molecules downstream of Src, signal transducers and activators of transcription 3, and signal transducers and activators of transcription 3, were significantly inhibited by bosutinib. K-Top Scoring Pairs analysis of gene arrays gave a six-gene classifier that predicted resistance versus sensitivity in six validation cases. These results may aid the clinical development of bosutinib and other Src inhibitors in pancreas cancer.
Subject(s)
Aniline Compounds/pharmacology , Nitriles/pharmacology , Pancreatic Neoplasms/drug therapy , Quinolines/pharmacology , Xenograft Model Antitumor Assays , Aniline Compounds/pharmacokinetics , Animals , Blotting, Western , Caveolin 1/genetics , Caveolin 1/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Female , Gene Expression Profiling , Gene Expression Regulation, Neoplastic/drug effects , Humans , Immunohistochemistry , Mice , Mice, Nude , Nitriles/pharmacokinetics , Oncogene Protein pp60(v-src)/metabolism , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Quinolines/pharmacokinetics , RNA Interference , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/drug effects , Treatment Outcome , Tumor Burden/drug effectsABSTRACT
Unbalanced histone deacetylase (HDAC) hyperactivity is a common feature of tumor cells. Inhibition of HDAC activity is often associated with cancer cell growth impairment and death. Valproic acid (VPA) is a HDAC inhibitor used for the treatment of epilepsy. It has recently been recognized as a promising anticancer drug. We investigated the effects of VPA on growth and survival of colon cancer cells. VPA caused growth inhibition and programmed cell death that correlated with histone hyperacetylation. VPA modulated the expression of various factors involved in cell cycle control and apoptosis and induced caspase activation. Interestingly, VPA induced downregulation of c-Src and potentiated the cytotoxic effects of the c-Src inhibitor bosutinib, both in vitro and in vivo. The combination of sublethal doses of VPA and bosutinib led to massive apoptosis of colon cancer cells, irrespective of their genetic background. These results suggest that VPA may be employed as a positive modulator of bosutinib antitumor activity in colorectal cancer.
Subject(s)
Aniline Compounds/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colonic Neoplasms/drug therapy , Drug Synergism , Gene Expression Regulation, Neoplastic , Nitriles/administration & dosage , Quinolines/administration & dosage , Valproic Acid/administration & dosage , Acetylation , Animals , Apoptosis , Cell Line, Tumor , Female , Histones/metabolism , Humans , Mice , Mice, Nude , src-Family Kinases/metabolismSubject(s)
Aniline Compounds/therapeutic use , Antineoplastic Agents/therapeutic use , Genes, abl/genetics , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Mutation , Nitriles/therapeutic use , Piperazines/therapeutic use , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Protein Kinase Inhibitors/therapeutic use , Pyrimidines/therapeutic use , Quinolines/therapeutic use , Thiazoles/therapeutic use , Benzamides , Dasatinib , Drug Resistance, Neoplasm , Imatinib Mesylate , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Philadelphia ChromosomeABSTRACT
Insulin-like growth factor receptor (IGF-1R) is a growth factor receptor tyrosine kinase that acts as a critical mediator of cell proliferation and survival. Inhibitors of this receptor are believed to provide a new target in cancer therapy. We previously reported an isoquinolinedione series of IGF-1R inhibitors. Now we have identified a series of 3-cyanoquinoline compounds that are low nanomolar inhibitors of IGF-1R. The strategies, synthesis, and SAR behind the cyanoquinoline scaffold will be discussed.
Subject(s)
Antineoplastic Agents/chemical synthesis , Nitriles/chemical synthesis , Quinolines/chemical synthesis , Receptor, IGF Type 1/antagonists & inhibitors , Humans , Nitriles/pharmacology , Quinolines/pharmacology , Structure-Activity RelationshipABSTRACT
Insulin-like growth factor receptor (IGF-1R) is a growth factor receptor tyrosine kinase that acts as a critical mediator of cell proliferation and survival. This receptor is over-expressed or activated in tumor cells and is emerging as a novel target in cancer therapy. Efforts in our "Hit to Lead" group have generated a novel series of submicromolar IGF-1R inhibitors based on a isoquinolinedione template originating from a Lance enzyme HTS screen. Chemical triage and parallel synthesis incorporating focused library arrays were instrumental in moving these investigations through the Wyeth exploratory medicinal chemistry process. The strategies, synthesis, and SAR behind this interesting kinase scaffold will be described.
Subject(s)
Antineoplastic Agents/pharmacology , Isoquinolines/pharmacology , Receptor, IGF Type 1/antagonists & inhibitors , Antineoplastic Agents/chemistry , Dose-Response Relationship, Drug , Drug Design , Drug Screening Assays, Antitumor , Isoquinolines/chemistry , Models, Molecular , Molecular Structure , Small Molecule Libraries , Structure-Activity RelationshipABSTRACT
Src family kinase activity is elevated in many human tumors, including breast cancer, and is often associated with aggressive disease. We examined the effects of SKI-606 (bosutinib), a selective Src family kinase inhibitor, on human cancer cells derived from breast cancer patients to assess its potential for breast cancer treatment. Our results show that SKI-606 caused a decrease in cell motility and invasion of breast cancer cell lines with an IC50 of approximately 250 nmol/L, which was also the IC50 for inhibition of cellular Src kinase activity in intact tumor cells. These changes were accompanied by an increase in cell-to-cell adhesion and membrane localization of beta-catenin. By contrast, cell proliferation and survival were unaffected by SKI-606 at concentrations sufficient to block cell migration and invasion. Analysis of downstream effectors of Src revealed that SKI-606 inhibits the phosphorylation of focal adhesion kinase (FAK), proline-rich tyrosine kinase 2 (Pyk2), and Crk-associated substrate (p130Cas), with an IC50 similar to inhibition of cellular Src kinase. Our findings indicate that SKI-606 inhibits signaling pathways involved in controlling tumor cell motility and invasion, suggesting that SKI-606 is a promising therapeutic for breast cancer.
Subject(s)
Aniline Compounds/pharmacology , Antineoplastic Agents/pharmacology , Breast Neoplasms/enzymology , Cell Movement/drug effects , Nitriles/pharmacology , Protein Kinase Inhibitors/pharmacology , Quinolines/pharmacology , src-Family Kinases/antagonists & inhibitors , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Adhesion , Cell Line, Tumor , Cell Proliferation , Crk-Associated Substrate Protein/antagonists & inhibitors , Crk-Associated Substrate Protein/metabolism , Female , Focal Adhesion Kinase 1/antagonists & inhibitors , Focal Adhesion Kinase 1/metabolism , Humans , Models, Biological , Phosphorylation , Signal Transduction , beta Catenin/metabolism , src-Family Kinases/metabolismABSTRACT
Heat shock protein 90 (Hsp90) is a molecular chaperone that is responsible for activating many signaling proteins and is a promising target in tumor biology. We have identified small-molecule benzisoxazole derivatives as Hsp90 inhibitors. Crystallographic studies show that these compounds bind in the ATP binding pocket interacting with the Asp93. Structure based optimization led to the identification of potent analogues, such as 13, with good biochemical profiles.
Subject(s)
Antineoplastic Agents/chemical synthesis , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Isoxazoles/chemical synthesis , Adenosine Triphosphate/metabolism , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Binding Sites , Cell Proliferation/drug effects , Crystallography, X-Ray , Drug Screening Assays, Antitumor , HSP90 Heat-Shock Proteins/metabolism , Humans , Isoxazoles/chemistry , Isoxazoles/pharmacology , K562 Cells , Models, Molecular , Protein Conformation , Structure-Activity RelationshipABSTRACT
We investigated the role of Src family kinases (SFKs) in the regulation of STAT activation in myeloid leukemia cells. Two of 6 AML cell lines displayed constitutive STAT5 activation, whereas four cell lines had constitutive SFK activity. Treatment with the SFK inhibitors suppressed STAT5 activation and decreased viability. Akt phosphorylation and Mcl-1 expression decreased after SFK inhibition accompanied by apoptosis induction. In primary AML specimens, SFK inhibitors suppressed proliferation in 5 of 14 specimens. These data indicate that Src-STAT5 and Src-Akt pathways are integral survival signal pathways in AML cells. Src inhibition may represent a novel treatment strategy for investigation in AML.