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Antimicrobial Agents and Chemotherapy Jan 2016Antimicrobial resistance is a global issue currently resulting in the deaths of hundreds of thousands of people a year worldwide. Data present in the literature...
Antimicrobial resistance is a global issue currently resulting in the deaths of hundreds of thousands of people a year worldwide. Data present in the literature illustrate the emergence of many bacterial species that display resistance to known antibiotics; Acinetobacter spp. are a good example of this. We report here that Acinetobacter radioresistens has a Baeyer-Villiger monooxygenase (Ar-BVMO) with 100% amino acid sequence identity to the ethionamide monooxygenase of multidrug-resistant (MDR) Acinetobacter baumannii. Both enzymes are only distantly phylogenetically related to other canonical bacterial BVMO proteins. Ar-BVMO not only is capable of oxidizing two anticancer drugs metabolized by human FMO3, danusertib and tozasertib, but also can oxidize other synthetic drugs, such as imipenem. The latter is a member of the carbapenems, a clinically important antibiotic family used in the treatment of MDR bacterial infections. Susceptibility tests performed by the Kirby-Bauer disk diffusion method demonstrate that imipenem-sensitive Escherichia coli BL21 cells overexpressing Ar-BVMO become resistant to this antibiotic. An agar disk diffusion assay proved that when imipenem reacts with Ar-BVMO, it loses its antibiotic property. Moreover, an NADPH consumption assay with the purified Ar-BVMO demonstrates that this antibiotic is indeed a substrate, and its product is identified by liquid chromatography-mass spectrometry to be a Baeyer-Villiger (BV) oxidation product of the carbonyl moiety of the β-lactam ring. This is the first report of an antibiotic-inactivating BVMO enzyme that, while mediating its usual BV oxidation, also operates by an unprecedented mechanism of carbapenem resistance.
Topics: Acinetobacter; Anti-Bacterial Agents; Antineoplastic Agents; Bacterial Proteins; Benzamides; Biotransformation; Cloning, Molecular; Disk Diffusion Antimicrobial Tests; Drug Resistance, Multiple, Bacterial; Escherichia coli; Gene Expression; Imipenem; Metabolic Engineering; Mixed Function Oxygenases; NADP; Oxidation-Reduction; Phylogeny; Piperazines; Pyrazoles; Recombinant Proteins
PubMed: 26459905
DOI: 10.1128/AAC.01088-15 -
Haematologica Jul 2015Danusertib is a pan-aurora kinase inhibitor with potent activity against Abl kinase including the gatekeeper T315I mutant. A phase 1 dose escalation study of danusertib...
A phase I study of danusertib (PHA-739358) in adult patients with accelerated or blastic phase chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia resistant or intolerant to imatinib and/or other second generation c-ABL therapy.
Danusertib is a pan-aurora kinase inhibitor with potent activity against Abl kinase including the gatekeeper T315I mutant. A phase 1 dose escalation study of danusertib was conducted in patients with accelerated or blastic phase chronic myeloid leukemia or Philadelphia chromosome-positive acute lymphoblastic leukemia. Two dosing schedules were studied: schedule A, in which danusertib was given by 3-hour intravenous infusion daily for 7 consecutive days (days 1-7) in a 14-day cycle, and schedule B, in which the danusertib was given by 3-hour intravenous infusion daily for 14 consecutive days (days 1-14) in a 21-day cycle. A total of 37 patients were treated, 29 with schedule A and eight with schedule B. The recommended phase 2 dose for schedule A was 180 mg/m(2). Enrollment to schedule B was stopped early because of logistical problems with the frequency of infusions. Febrile neutropenia and mucositis were dose-limiting toxicities in schedule A. Four patients with T315I ABL kinase mutation, all treated with schedule A, responded. Danusertib has an acceptable toxicity profile and is active in patients with Bcr-Abl-associated advanced hematologic malignancies. This study was registered with the European Clinical Trails Data Base (EudraCT number 2007-004070-18).
Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Benzamides; Blast Crisis; Drug Administration Schedule; Febrile Neutropenia; Female; Fusion Proteins, bcr-abl; Humans; Imatinib Mesylate; Leukemia, Myeloid, Accelerated Phase; Male; Middle Aged; Mucositis; Mutation; Philadelphia Chromosome; Protein Kinase Inhibitors; Pyrazoles
PubMed: 25887498
DOI: 10.3324/haematol.2014.115279 -
Drug Design, Development and Therapy 2015Gastric cancer is the second leading cause of cancer-related death worldwide, with a poor response to current chemotherapy. Danusertib is a pan-inhibitor of the Aurora...
Danusertib, a potent pan-Aurora kinase and ABL kinase inhibitor, induces cell cycle arrest and programmed cell death and inhibits epithelial to mesenchymal transition involving the PI3K/Akt/mTOR-mediated signaling pathway in human gastric cancer AGS and NCI-N78 cells.
Gastric cancer is the second leading cause of cancer-related death worldwide, with a poor response to current chemotherapy. Danusertib is a pan-inhibitor of the Aurora kinases and a third-generation Bcr-Abl tyrosine kinase inhibitor with potent anticancer effects, but its antitumor effect and underlying mechanisms in the treatment of human gastric cancer are unknown. This study aimed to investigate the effects of danusertib on cell growth, apoptosis, autophagy, and epithelial to mesenchymal transition and the molecular mechanisms involved in human gastric cancer AGS and NCI-N78 cells. The results showed that danusertib had potent growth-inhibitory, apoptosis-inducing, and autophagy-inducing effects on AGS and NCI-N78 cells. Danusertib arrested AGS and NCI-N78 cells in G2/M phase, with downregulation of expression of cyclin B1 and cyclin-dependent kinase 1 and upregulation of expression of p21 Waf1/Cip1, p27 Kip1, and p53. Danusertib induced mitochondria-mediated apoptosis, with an increase in expression of proapoptotic protein and a decrease in antiapoptotic proteins in both cell lines. Danusertib induced release of cytochrome c from the mitochondria to the cytosol and triggered activation of caspase 9 and caspase 3 in AGS and NCI-N78 cells. Further, danusertib induced autophagy, with an increase in expression of beclin 1 and conversion of microtubule-associated protein 1A/1B-light chain 3 (LC3-I) to LC3-II in both cell lines. Inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase pathways as well as activation of 5' AMP-activated protein kinase contributed to the proautophagic effect of danusertib in AGS and NCI-N78 cells. SB202191 and wortmannin enhanced the autophagy-inducing effect of danusertib in AGS and NCI-N78 cells. In addition, danusertib inhibited epithelial to mesenchymal transition with an increase in expression of E-cadherin and a decrease in expression of N-cadherin in both cell lines. Taken together, danusertib has potent inducing effects on cell cycle arrest, apoptosis, and autophagy, but has an inhibitory effect on epithelial to mesenchymal transition, with involvement of signaling pathways mediated by PI3K/Akt/mTOR, p38 mitogen-activated protein kinase, and 5' AMP-activated protein kinase in AGS and NCI-N78 cells.
Topics: Antineoplastic Agents; Apoptosis; Aurora Kinases; Benzamides; Cell Cycle Checkpoints; Cell Proliferation; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Epithelial-Mesenchymal Transition; Humans; Molecular Structure; Phosphatidylinositol 3-Kinase; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-abl; Proto-Oncogene Proteins c-akt; Pyrazoles; Signal Transduction; Stomach Neoplasms; Structure-Activity Relationship; TOR Serine-Threonine Kinases; Tumor Cells, Cultured
PubMed: 25767376
DOI: 10.2147/DDDT.S74964 -
Drug Design, Development and Therapy 2015Danusertib (Danu) is a pan-inhibitor of Aurora kinases and a third-generation breakpoint cluster region-Abelson murine leukemia viral oncogene homolog 1 (Bcr-Abl)...
Danusertib (Danu) is a pan-inhibitor of Aurora kinases and a third-generation breakpoint cluster region-Abelson murine leukemia viral oncogene homolog 1 (Bcr-Abl) tyrosine kinase inhibitor, but its antitumor effect and underlying mechanisms in the treatment of human breast cancer remain elusive. This study aimed to investigate the effects of Danu on the growth, apoptosis, autophagy, and epithelial-to-mesenchymal transition (EMT) and the molecular mechanisms in human breast cancer MCF7 and MDA-MB-231 cells. The results demonstrated that Danu remarkably inhibited cell proliferation, induced apoptosis and autophagy, and suppressed EMT in both breast cancer cell lines. Danu arrested MCF7 and MDA-MB-231 cells in G2/M phase, accompanied by the downregulation of cyclin-dependent kinase 1 and cyclin B1 and upregulation of p21 Waf1/Cip1, p27 Kip1, and p53. Danu significantly decreased the expression of B-cell lymphoma-extra-large (Bcl-xl) and B-cell lymphoma 2 (Bcl-2), but increased the expression of Bcl-2-associated X protein (Bax) and p53-upregulated modulator of apoptosis (PUMA), and promoted the cleavage of caspases 3 and 9. Furthermore, Danu significantly increased the expression levels of the membrane-bound microtubule-associated protein 1A/1B-light chain 3 (LC3-II) and beclin 1 in breast cancer cells, two markers for autophagy. Danu induced the activation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases 1 and 2 (Erk1/2) and inhibited the activation of protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathways in breast cancer cells. Treatment with wortmannin (a phosphatidylinositol 3-kinase inhibitor) markedly inhibited Danu-induced activation of p38 MAPK and conversion of cytosolic LC3-I to membrane-bound LC3-II. Pharmacological inhibition and small interfering RNA-mediated knockdown of p38 MAPK suppressed Akt activation, resulting in LC3-II accumulation and enhanced autophagy. Pharmacological inhibition and small interfering RNA-mediated knockdown of Erk1/2 also remarkably increased the level of LC3-II in MCF7 cells. Moreover, Danu inhibited EMT in both MCF7 and MDA-MB-231 cells with upregulated E-cadherin and zona occludens protein 1 (ZO-1) but downregulated N-cadherin, zinc finger E-box-binding homeobox 1 (TCF8/ZEB1), snail, slug, vimentin, and β-catenin. Notably, Danu showed lower cytotoxicity toward normal breast epithelial MCF10A cells. These findings indicate that Danu promotes cellular apoptosis and autophagy but inhibits EMT in human breast cancer cells via modulation of p38 MAPK/Erk1/2/Akt/mTOR signaling pathways. Danu may represent a promising anticancer agent for breast cancer treatment. More studies are warranted to fully delineate the underlying mechanisms, efficacy, and safety of Danu in breast cancer therapy.
Topics: Apoptosis; Aurora Kinases; Autophagy; Benzamides; Breast Neoplasms; Cell Cycle; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Epithelial-Mesenchymal Transition; Humans; MCF-7 Cells; Molecular Structure; Protein Kinase Inhibitors; Pyrazoles; Structure-Activity Relationship; Tumor Cells, Cultured
PubMed: 25733818
DOI: 10.2147/DDDT.S74412 -
Annals of Oncology : Official Journal... Mar 2015This multi-centre phase II trial assessed the activity, safety (CTCAE 3.0) and pharmacokinetics (PK) of the pan-Aurora kinase inhibitor danusertib hydrochloride...
Efficacy and safety of biweekly i.v. administrations of the Aurora kinase inhibitor danusertib hydrochloride in independent cohorts of patients with advanced or metastatic breast, ovarian, colorectal, pancreatic, small-cell and non-small-cell lung cancer: a multi-tumour, multi-institutional phase...
BACKGROUND
This multi-centre phase II trial assessed the activity, safety (CTCAE 3.0) and pharmacokinetics (PK) of the pan-Aurora kinase inhibitor danusertib hydrochloride (PHA-739358) in breast (BC), ovarian (OC), pancreatic (PC), colorectal (CRC), small-cell (SCLC) and non-small-cell lung (NSCLC) cancers.
METHODS
Consenting adult patients with good performance and organ function with advanced/metastatic tumours who had failed systemic therapy were treated in independent, disease-specific cohorts with danusertib 500 mg/m(2) given as 24-h i.v. infusion every 14 days with until progression or unacceptable toxicity. A two-stage design was applied. Primary end point was the progression-free rate (PFR) at 4 months (RECIST1.1).
RESULTS
A total of 223 patients were enrolled with 219 actively treated. The median relative dose intensity of danusertib was similar for all tumour types (84.6%-99.6%). The median number of biweekly treatment cycles ranged from 3 to 4/patient (maximum 5-40 cycles/entity) and the median treatment duration varied between 7.6 and 10.0 weeks per histotype. Danusertib did not meet pre-specified protocol criteria for clinically relevant activity in any of the treated cancers. The PFR at 4 months was 18.4% in BC, 12.1% in OC, 10.0% in PC, 10.4% in NSCLC (all histotypes), 16.1% in squamous NSCLC and 0% in SCLC and CRC. Some radiological and/or biochemical indication of antitumor activity was seen in BC, OC, PC and NSCLC, including two confirmed partial responses. The most frequent drug-related non-laboratory adverse events (AEs) were fatigue/asthenia, nausea, diarrhoea, anorexia, vomiting, alopecia, constipation and pyrexia. Common laboratory AEs included haematological toxicity, hypalbuminaemia and increases in liver enzymes. Treatment was discontinued due to AEs in only 5.5% of patients. Plasma concentrations of danusertib were in line with results from earlier studies.
CONCLUSION
Single-agent danusertib did show only marginal anti-tumour activity in common solid tumours after failure of prior systemic therapies. The safety and PK profile was consistent with previous experience.
CLINICAL TRIAL NUMBER
2006-003772-35.
Topics: Administration, Intravenous; Aged; Aurora Kinases; Benzamides; Breast Neoplasms; Carcinoma, Non-Small-Cell Lung; Cohort Studies; Colorectal Neoplasms; Drug Administration Schedule; Female; Humans; Lung Neoplasms; Male; Middle Aged; Ovarian Neoplasms; Prospective Studies; Protein Kinase Inhibitors; Pyrazoles; Small Cell Lung Carcinoma; Treatment Outcome
PubMed: 25488684
DOI: 10.1093/annonc/mdu566 -
PloS One 2014ABL tyrosine kinase inhibitors (TKI) like Imatinib, Dasatinib and Nilotinib are the gold standard in conventional treatment of CML. However, the emergence of resistance...
Inhibition of Aurora kinase B is important for biologic activity of the dual inhibitors of BCR-ABL and Aurora kinases R763/AS703569 and PHA-739358 in BCR-ABL transformed cells.
ABL tyrosine kinase inhibitors (TKI) like Imatinib, Dasatinib and Nilotinib are the gold standard in conventional treatment of CML. However, the emergence of resistance remains a major problem. Alternative therapeutic strategies of ABL TKI-resistant CML are urgently needed. We asked whether dual inhibition of BCR-ABL and Aurora kinases A-C could overcome resistance mediated by ABL kinase mutations. We therefore tested the dual ABL and Aurora kinase inhibitors PHA-739358 and R763/AS703569 in Ba/F3- cells ectopically expressing wild type (wt) or TKI-resistant BCR-ABL mutants. We show that both compounds exhibited strong anti-proliferative and pro-apoptotic activity in ABL TKI resistant cell lines including cells expressing the strongly resistant T315I mutation. Cell cycle analysis indicated polyploidisation, a consequence of continued cell cycle progression in the absence of cell division by Aurora kinase inhibition. Experiments using drug resistant variants of Aurora B indicated that PHA-739358 acts on both, BCR-ABL and Aurora Kinase B, whereas Aurora kinase B inhibition might be sufficient for the anti-proliferative activity observed with R763/AS703569. Taken together, our data demonstrate that dual ABL and Aurora kinase inhibition might be used to overcome ABL TKI resistant CML.
Topics: Animals; Antineoplastic Agents; Apoptosis; Aurora Kinase B; B-Lymphocytes; Base Sequence; Benzamides; Cell Cycle; Cell Line, Transformed; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Fusion Proteins, bcr-abl; Gene Expression; Humans; Mice; Molecular Docking Simulation; Molecular Sequence Data; Norbornanes; Protein Kinase Inhibitors; Pyrazoles; Pyrimidines
PubMed: 25426931
DOI: 10.1371/journal.pone.0112318