5-alpha-reductase: 2012-10-21

2012年10月27日星期六

Formation of stable attachments between kinetochores and microtubules depends on the B56-PP2A phosphatase.

Formation of stable attachments between kinetochores and microtubules depends on the B56-PP2A phosphatase.

Nat Cell Biol. 2011 Oct;13(10):1265-71

Authors: Foley EA, Maldonado M, Kapoor TM

Abstract
Error-free chromosome segregation depends on the precise regulation of phosphorylation to stabilize kinetochore-microtubule attachments (K-fibres) on sister chromatids that have attached to opposite spindle poles (bi-oriented). In many instances, phosphorylation correlates with K-fibre destabilization. Consistent with this, multiple kinases, including Aurora B and Plk1, are enriched at kinetochores of mal-oriented chromosomes when compared with bi-oriented chromosomes, which have stable attachments. Paradoxically, however, these kinases also target to prometaphase chromosomes that have not yet established spindle attachments and it is therefore unclear how kinetochore-microtubule interactions can be stabilized when kinase levels are high. Here we show that the generation of stable K-fibres depends on the B56-PP2A phosphatase, which is enriched at centromeres/kinetochores of unattached chromosomes. When B56-PP2A is depleted, K-fibres are destabilized and chromosomes fail to align at the spindle equator. Strikingly, B56-PP2A depletion increases the level of phosphorylation of Aurora B and Plk1 kinetochore substrates as well as Plk1 recruitment to kinetochores. Consistent with increased substrate phosphorylation, we find that chemical inhibition of Aurora or Plk1 restores K-fibres in B56-PP2A-depleted cells. Our findings reveal that PP2A, an essential tumour suppressor, tunes the balance of phosphorylation to promote chromosome-spindle interactions during cell division.

PMID: 21874008 [PubMed - indexed for MEDLINE]

dna-pk coxinhibitors c-met inhibitors

Geminin overexpression induces mammary tumors via suppressing cytokinesis.

Geminin overexpression induces mammary tumors via suppressing cytokinesis.

Oncotarget. 2011 Dec;2(12):1011-27

Authors: Blanchard Z, Malik R, Mullins N, Maric C, Luk H, Horio D, Hernandez B, Killeen J, Elshamy WM

Abstract
Aneuploidy plays an important role in the development of cancer. Here, we uncovered an oncogenic role for geminin in mitotic cells. In addition to chromatin, tyrosine phosphorylated geminin also localizes to centrosome, spindle, cleavage furrow and midbody during mitosis. Geminin binding to Aurora B prevents its binding to INCENP, and thus activation leading to lack of histone H3-(serine 10) phosphorylation, chromosome condensation failure, aborted cytokinesis and the formation of aneuploid, drug resistance cells. Geminin overexpressing human mammary epithelial cells form aneuploid, aggressive tumors in SCID mice. Geminin is overexpressed in more than half of all breast cancers analyzed. The current study reveals that geminin is a genuine oncogene that promotes cytokinesis failure and production of aneuploid, aggressive breast tumors when overexpressed and thus a worthy therapeutic target (oncotarget) for aggressive breast cancer.

PMID: 22184288 [PubMed - indexed for MEDLINE]

dna-pk coxinhibitors c-met inhibitors

Investigating the role of Aurora kinases in RAS signaling.

Investigating the role of Aurora kinases in RAS signaling.

J Cell Biochem. 2009 Jan 1;106(1):33-41

Authors: Kosik A, Bekier ME, Katusin JD, Kaur H, Zhou X, Diakonova M, Chadee DN, Taylor WR

Abstract
Activating ras mutations are frequently found in malignant tumors of the pancreas, colon, lung and other tissues. RAS activates a number of downstream pathways that ultimately cause cellular transformation. Several recent studies suggested that one of those pathways involves Aurora kinases. Overexpression of Aurora-B kinase can augment transformation by oncogenic RAS, however the mechanism was not determined. The cooperative effect of high levels of Aurora kinase is important since this kinase is frequently overexpressed in human tumors. We have used two Aurora kinase inhibitors to test their effect on RAS signaling. We find that these inhibitors have no effect on the phosphorylation of MEK1/2 or MAPK in response to RAS. Furthermore, inhibiting Aurora kinases in human cancer cells with or without activated RAS did not change the length of the cell cycle nor induce apoptosis suggesting that these kinases do not play a direct role in these key cellular responses to activated RAS. Overexpression of Aurora B can cause cells to become polyploid. Also, inducing polyploidy with cytochalasin D was reported to induce neoplastic transformation, suggesting that Aurora overexpression may cooperate with RAS indirectly by inducing polyploidy. We find that inducing polyploidy with cytochalasin D or blebbistatin does not enhance transformation by oncogenic RAS. Our observations argue against a direct role for Aurora kinases in the RAS-MAPK pathway, and suggest that the polyploid state does not enhance transformation by RAS.

PMID: 19009561 [PubMed - indexed for MEDLINE]

zm-447439 rad001 ecdysone

The anticancer multi-kinase inhibitor dovitinib also targets topoisomerase I and topoisomerase II.

The anticancer multi-kinase inhibitor dovitinib also targets topoisomerase I and topoisomerase II.

Biochem Pharmacol. 2012 Oct 4;

Authors: Hasinoff BB, Wu X, Nitiss JL, Kanagasabai R, Yalowich JC

Abstract
Dovitinib (TKI258/CHIR258) is a multi-kinase inhibitor in phase III development for the treatment of several cancers. Dovitinib is a benzimidazole-quinolinone compound that structurally resembles the bisbenzimidazole minor groove binding dye Hoechst 33258. Dovitinib bound to DNA as shown by its ability to increase the DNA melting temperature and by increases in its fluorescence spectrum that occurred upon the addition of DNA. Molecular modeling studies of the docking of dovitinib into an X-ray structure of a Hoechst 33258-DNA complex showed that dovitinib could reasonably be accommodated in the DNA minor groove. Because DNA binders are often topoisomerase I (EC 5.99.1.2) and topoisomerase II (EC 5.99.1.3) inhibitors, the ability of dovitinib to inhibit these DNA processing enzymes was also investigated. Dovitinib inhibited the catalytic decatenation activity of topoisomerase II?. It also inhibited the DNA-independent ATPase activity of yeast topoisomerase II which suggested that it interacted with the ATP binding site. Using isolated human topoisomerase II?, dovitinib stabilized the enzyme-cleavage complex and acted as a topoisomerase II? poison. Dovitinib was also found to be a cellular topoisomerase II poison in human leukemia K562 cells and induced double-strand DNA breaks in K562 cells as evidenced by increased phosphorylation of H2AX. Finally, dovitinib inhibited the topoisomerase I-catalyzed relaxation of plasmid DNA and acted as a cellular topoisomerase I poison. In conclusion, the cell growth inhibitory activity and the anticancer activity of dovitinib may result not only from its ability to inhibit multiple kinases, but also, in part, from its ability to target topoisomerase I and topoisomerase II.

PMID: 23041231 [PubMed - as supplied by publisher]

c-met inhibitors zm-447439 rad001

2012年10月26日星期五

Aurora B couples chromosome alignment with anaphase by targeting BubR1, Mad2, and Cenp-E to kinetochores.

Aurora B couples chromosome alignment with anaphase by targeting BubR1, Mad2, and Cenp-E to kinetochores.

J Cell Biol. 2003 Apr 28;161(2):267-80

Authors: Ditchfield C, Johnson VL, Tighe A, Ellston R, Haworth C, Johnson T, Mortlock A, Keen N, Taylor SS

Abstract
The Aurora/Ipl1 family of protein kinases plays multiple roles in mitosis and cytokinesis. Here, we describe ZM447439, a novel selective Aurora kinase inhibitor. Cells treated with ZM447439 progress through interphase, enter mitosis normally, and assemble bipolar spindles. However, chromosome alignment, segregation, and cytokinesis all fail. Despite the presence of maloriented chromosomes, ZM447439-treated cells exit mitosis with normal kinetics, indicating that the spindle checkpoint is compromised. Indeed, ZM447439 prevents mitotic arrest after exposure to paclitaxel. RNA interference experiments suggest that these phenotypes are due to inhibition of Aurora B, not Aurora A or some other kinase. In the absence of Aurora B function, kinetochore localization of the spindle checkpoint components BubR1, Mad2, and Cenp-E is diminished. Furthermore, inhibition of Aurora B kinase activity prevents the rebinding of BubR1 to metaphase kinetochores after a reduction in centromeric tension. Aurora B kinase activity is also required for phosphorylation of BubR1 on entry into mitosis. Finally, we show that BubR1 is not only required for spindle checkpoint function, but is also required for chromosome alignment. Together, these results suggest that by targeting checkpoint proteins to kinetochores, Aurora B couples chromosome alignment with anaphase onset.

PMID: 12719470 [PubMed - indexed for MEDLINE]

ecdysone chir-258 dovitinib

Cloning, ligand-binding, and temporal expression of ecdysteroid receptors in the diamondback moth, Plutella xylostella.

Cloning, ligand-binding, and temporal expression of ecdysteroid receptors in the diamondback moth, Plutella xylostella.

BMC Mol Biol. 2012 Oct 19;13(1):32

Authors: Tang B, Dong W, Liang P, Zhou X, Gao X

Abstract
ABSTRACT: BACKGROUND: The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a devastating pest of cruciferous crops worldwide, and has developed resistance to a wide range of insecticides, including diacylhydrazine-based ecdysone agonists, a highly selective group of molt-accelerating biopesticides targeting the ecdysone receptors.ResultIn this study, we cloned and characterized the ecdysone receptors from P. xylostella, including the two isoforms of EcR and a USP. Sequence comparison and phylogenetic analysis showed striking conservations among insect ecdysone receptors, especially between P. xylostella and other lepidopterans. The binding affinity of ecdysteroids to in vitro-translated receptor proteins indicated that PxEcRB isoform bound specifically to ponasterone A, and the binding affinity was enhanced by co-incubation with PxUSP (Kd =3.0+/-1.7 nM). In contrast, PxEcRA did not bind to ponasterone A, even in the presence of PxUSP. The expression of PxEcRB were consistently higher than that of PxEcRA across each and every developmental stage, while the pattern of PxUSP expression is more or less ubiquitous. CONCLUSIONS: Target site insensitivity, in which the altered binding of insecticides (ecdysone agonists) to their targets (ecdysone receptors) leads to an adaptive response (resistance), is one of the underlying mechanisms of diacylhydrazine resistance. Given the distinct differences at expression level and the ligand-binding capacity, we hypothesis that PxEcRB is the ecdysone receptor that controls the remodeling events during metamorphosis. More importantly, PxEcRB is the potential target site which is modified in the ecdysone agonist-resistant P. xylostella.

PMID: 23078528 [PubMed - as supplied by publisher]

zm-447439 rad001 ecdysone

Geminin overexpression induces mammary tumors via suppressing cytokinesis.

Geminin overexpression induces mammary tumors via suppressing cytokinesis.

Oncotarget. 2011 Dec;2(12):1011-27

Authors: Blanchard Z, Malik R, Mullins N, Maric C, Luk H, Horio D, Hernandez B, Killeen J, Elshamy WM

PMID: 22184288 [PubMed - indexed for MEDLINE]

dovitinib dna-pk coxinhibitors

Inhibition of Aurora kinases enhances chemosensitivity to temozolomide and causes radiosensitization in glioblastoma cells.

Inhibition of Aurora kinases enhances chemosensitivity to temozolomide and causes radiosensitization in glioblastoma cells.

J Cancer Res Clin Oncol. 2012 Mar;138(3):405-14

Authors: Borges KS, Castro-Gamero AM, Moreno DA, da Silva Silveira V, Brassesco MS, de Paula Queiroz RG, de Oliveira HF, Carlotti CG, Scrideli CA, Tone LG

Abstract
BACKGROUND: Glioblastoma remains one of the most devastating human malignancies, and despite therapeutic advances, there are no drugs that significantly improve the patient survival. Altered expression of the Aurora kinases was found in different malignancies, and their inhibition has been studied in cancer therapy. In this study, we analyzed the expression of Aurora A and Aurora B in glioblastoma samples and also analyzed whether the effects of Aurora kinase inhibition were associated with temozolomide or not on cell lines and primary cultures of glioblastoma.
MATERIALS AND METHODS: RT-PCR assays were used to determine the mRNA expression in glioblastoma tumor samples and in the cell lines. Cell proliferation was measured by XTT assay, and apoptosis was determined by flow cytometry. Drug combination analyses were made based in Chou-Talalay method. Gamma radiation for clonogenic survival used the doses of 2, 4 and 6 Gy. Changes in Aurora B level were assessed by Western blot analysis.
RESULTS: Aurora A and B were expressed in glioblastoma samples as well as in the glioblastoma cell lines (n = 6). Moreover, ZM447439, a selective Aurora kinase inhibitor, decreased the proliferation separately and synergistically with temozolomide in primary cultures and cell lines of glioblastoma. ZM also enhanced the effects of radiation on the two cell lines studied (U343 and U251), mainly when associated with TMZ in U343 cells. Treatment with ZM induced apoptotic cell death and diminished Aurora B protein level.
CONCLUSIONS: These data suggest that Aurora kinase inhibition may be a target for glioblastoma treatment and could be used as adjuvant to chemo- and radiotherapy.

PMID: 22160182 [PubMed - indexed for MEDLINE]

chir-258 dovitinib dna-pk

Cloning, ligand-binding, and temporal expression of ecdysteroid receptors in the diamondback moth, Plutella xylostella.

Cloning, ligand-binding, and temporal expression of ecdysteroid receptors in the diamondback moth, Plutella xylostella.

BMC Mol Biol. 2012 Oct 19;13(1):32

Authors: Tang B, Dong W, Liang P, Zhou X, Gao X

PMID: 23078528 [PubMed - as supplied by publisher]

chir-258 dovitinib dna-pk

2012年10月25日星期四

A novel treatment strategy targeting Aurora kinases in acute myelogenous leukemia.

A novel treatment strategy targeting Aurora kinases in acute myelogenous leukemia.

Mol Cancer Ther. 2007 Jun;6(6):1851-7

Authors: Ikezoe T, Yang J, Nishioka C, Tasaka T, Taniguchi A, Kuwayama Y, Komatsu N, Bandobashi K, Togitani K, Koeffler HP, Taguchi H

Abstract
The Aurora kinases play an important role in chromosome alignment, segregation, and cytokinesis during mitosis. Aberrant expression of these kinases occurs in solid tumors and is associated with aneuploidy and carcinogenesis. We found in this study that Aurora kinase A and B were aberrantly expressed in a variety of types of human leukemia cell lines (n = 15, e.g., PALL-1, PALL-2, HL-60, NB4, MV4-11, etc.), as well as freshly isolated leukemia cells from individuals with acute myelogenous leukemia (n = 44) compared with bone marrow mononuclear cells from healthy volunteers (n = 11), as measured by real-time PCR. ZM447439 is a novel selective Aurora kinase inhibitor. The compound induced growth inhibition, caused accumulation of cells with 4N/8N DNA content, and mediated apoptosis of human leukemia cells as measured by thymidine uptake, cell cycle analysis, and annexin V staining, respectively. Especially profound growth inhibition occurred with the PALL-1 and PALL-2 cells, which possess wild-type p53 gene. In contrast, ZM447439 did not inhibit clonogenic growth of myeloid committed stem cells harvested from healthy normal volunteers. Taken together, inhibition of Aurora kinases may be a promising treatment strategy for individuals with leukemia.

PMID: 17541033 [PubMed - indexed for MEDLINE]

chir-258 dovitinib dna-pk

The Ipl1/Aurora kinase family: methods of inhibition and functional analysis in mammalian cells.

The Ipl1/Aurora kinase family: methods of inhibition and functional analysis in mammalian cells.

Methods Mol Biol. 2005;296:371-81

Authors: Ditchfield C, Keen N, Taylor SS

Abstract
The Ipl1/Aurora family of protein kinases are required for accurate chromosome segregation. Because members of this family are often overexpressed in human tumors, they have recently received much attention, both from the academic community and the pharmaceutical industry. Indeed, two small molecule Aurora kinase inhibitors have recently been described. In this chapter, we describe several methods for investigating the function of the Aurora kinases, focusing on Aurora B. We describe the use of the small-molecule inhibitor ZM447439, RNA interference, and overexpression of a catalytic mutant. All of these methods have proved useful in studying Aurora B as well as validating it as a potential anticancer drug target. However, while all three methods are useful for probing the function of Aurora B, each has inherent advantages and disadvantages. Furthermore, because the mechanism underlying the inhibition is different in each case, caution must be taken when interpreting the data.

PMID: 15576945 [PubMed - indexed for MEDLINE]

c-met inhibitors zm-447439 rad001

Percutaneous coronary intervention for acute myocardial infarction in a pediatric patient with coronary aneurysm and stenosis due to Kawasaki disease.

Percutaneous coronary intervention for acute myocardial infarction in a pediatric patient with coronary aneurysm and stenosis due to Kawasaki disease.

Pediatr Cardiol. 2012 Jun;33(5):811-3

Authors: Drossner DM, Chappell C, Rab T, Kim D

Abstract
We report the case of an acutely ill 3-year-old female, with a previous medical history of Kawasaki disease, who presented to care with an acute myocardial infarction. We describe the coordinated therapies employed by pediatric and adult cardiologists aimed to establish coronary revascularization.

PMID: 22311571 [PubMed - indexed for MEDLINE]

chir-258 dovitinib dna-pk

Antiproliferative effect of Aurora kinase targeting in mesothelioma.

Antiproliferative effect of Aurora kinase targeting in mesothelioma.

Lung Cancer. 2010 Dec;70(3):271-9

Authors: Crispi S, Fagliarone C, Biroccio A, D'Angelo C, Galati R, Sacchi A, Vincenzi B, Baldi A, Verdina A

Abstract
The Aurora proteins are a small family of serine/threonine kinase that function in various stages of mitosis. Current interest in Aurora kinase relates to its role in tumours, and its potential as a therapeutic target. In this work we studied the expression of Aurora kinases A and B and related genes in human mesothelioma tissues and in five mesothelioma cell lines. Moreover, we analyzed the effects of ZM447439 (ZM), an Aurora kinase inhibitor, on cellular growth. Results evidenced an over-expression of Aurora kinase A and related genes in human mesothelioma tissues and an over-expression of Aurora kinases A and B in all cell lines. Moreover, we demonstrated that ZM447439 was able to inhibit cell growth in all cell lines and that this inhibition was due to a specific effect as demonstrated by the reduction in the level of Histone H3 phosphorylation. Our findings support a role of Aurora kinase in mesothelioma and the possibility of using Aurora kinase inhibitors in therapeutic modalities.

PMID: 20371132 [PubMed - indexed for MEDLINE]

rad001 ecdysone chir-258

MAPK interacts with XGef and is required for CPEB activation during meiosis in Xenopus oocytes.

MAPK interacts with XGef and is required for CPEB activation during meiosis in Xenopus oocytes.

J Cell Sci. 2007 Mar 15;120(Pt 6):1093-103

Authors: Keady BT, Kuo P, Mart�nez SE, Yuan L, Hake LE

Abstract
Meiotic progression in Xenopus oocytes, and all other oocytes investigated, is dependent on polyadenylation-induced translation of stockpiled maternal mRNAs. Early during meiotic resumption, phosphorylation of CPE-binding protein (CPEB) is required for polyadenylation-induced translation of mRNAs encoding cell cycle regulators. Xenopus Gef (XGef), a Rho-family guanine-exchange factor, influences the activating phosphorylation of CPEB. An exchange-deficient version of XGef does not, therefore implicating Rho-family GTPase function in early meiosis. We show here that Clostridium difficile Toxin B, a Rho-family GTPase inhibitor, does not impair early CPEB phosphorylation or progression to germinal vesicle breakdown, indicating that XGef does not influence these events through activation of a Toxin-B-sensitive GTPase. Using the inhibitors U0126 for mitogen-activated protein kinase (MAPK), and ZM447439 for Aurora kinase A and Aurora kinase B, we found that MAPK is required for phosphorylation of CPEB, whereas Aurora kinases are not. Furthermore, we do not detect active Aurora kinase A in early meiosis. By contrast, we observe an early, transient activation of MAPK, independent of Mos protein expression. MAPK directly phosphorylates CPEB on four residues (T22, T164, S184, S248), but not on S174, a key residue for activating CPEB function. Notably, XGef immunoprecipitates contain MAPK, and this complex can phosphorylate CPEB. MAPK may prime CPEB for phosphorylation on S174 by an as-yet-unidentified kinase or may activate this kinase.

PMID: 17344432 [PubMed - indexed for MEDLINE]

coxinhibitors c-met inhibitors zm-447439

2012年10月24日星期三

Investigating the role of Aurora kinases in RAS signaling.

Investigating the role of Aurora kinases in RAS signaling.

J Cell Biochem. 2009 Jan 1;106(1):33-41

Authors: Kosik A, Bekier ME, Katusin JD, Kaur H, Zhou X, Diakonova M, Chadee DN, Taylor WR

PMID: 19009561 [PubMed - indexed for MEDLINE]

zm-447439 rad001 ecdysone

Inhibition of survivin and aurora B kinase sensitizes mesothelioma cells by enhancing mitotic arrests.

Inhibition of survivin and aurora B kinase sensitizes mesothelioma cells by enhancing mitotic arrests.

Int J Radiat Oncol Biol Phys. 2007 Apr 1;67(5):1519-25

Authors: Kim KW, Mutter RW, Willey CD, Subhawong TK, Shinohara ET, Albert JM, Ling G, Cao C, Gi YJ, Lu B

Abstract
PURPOSE: Survivin, a member of the inhibitor of apoptosis gene family, has also been shown to regulate mitosis. It binds Aurora B kinase and the inner centromere protein to form the chromosome passenger complex. Both Aurora B and survivin are overexpressed in many tumors. In this study, we examined whether irradiation affected survivin and Aurora B expression in mesothelioma cells, and how inhibition of these molecules affected radiosensitivity.
METHODS AND MATERIALS: ZM447439 and survivin antisense oligonucleotides were used to inhibit survivin and Aurora B kinase respectively. Western blot was performed to determine the expression of survivin, Aurora B, phosphorylated-histone H3 (Ser 10), and caspase cleavage. Multinucleated cells were counted using flow cytometry, and cell survival after treatment was determined using clonogenic assay.
RESULTS: At 3-Gy irradiation an increase was observed in levels of survivin and Aurora B as well as the kinase activity of Aurora B, with an increase in G2/M phase. The radiation-induced upregulation of these molecules was effectively attenuated by antisense oligonucleotides against survivin and a small-molecule inhibitor of Aurora B, ZM447439. Dual inhibition of survivin and Aurora B synergistically radiosensitized mesothelioma cells with a dose enhancement ratio of 2.55. This treatment resulted in increased formation of multinucleated cells after irradiation but did not increase levels of cleaved caspase 3.
CONCLUSION: Inhibition of survivin and Aurora B induces mitotic cell arrest in mesothelioma cells after irradiation. These two proteins may be potential therapeutic targets for the enhancement of radiotherapy in malignant pleural mesothelioma.

PMID: 17394948 [PubMed - indexed for MEDLINE]

c-met inhibitors zm-447439 rad001

Effects of the aurora kinase inhibitors AZD1152-HQPA and ZM447439 on growth arrest and polyploidy in acute myeloid leukemia cell lines and primary blasts.

Effects of the aurora kinase inhibitors AZD1152-HQPA and ZM447439 on growth arrest and polyploidy in acute myeloid leukemia cell lines and primary blasts.

Haematologica. 2008 May;93(5):662-9

Authors: Walsby E, Walsh V, Pepper C, Burnett A, Mills K

Abstract
BACKGROUND: Aurora kinases play an essential role in the orchestration of chromosome separation and cytokinesis during mitosis. Small-molecule inhibition of the aurora kinases has been shown to result in inhibition of cell division, phosphorylation of histone H3 and the induction of apoptosis in a number of cell systems. These characteristics have led aurora kinase inhibitors to be considered as potential therapeutic agents.
DESIGN AND METHODS: Aurora kinase gene expression profiles were assessed in 101 samples from patients with acute myeloid leukemia. Subsequently, aurora kinase inhibitors were investigated for their in vitro effects on cell viability, histone H3 phosphorylation, cell cycle and morphology in acute myeloid leukemia cell lines and primary acute myeloid leukemia samples.
RESULTS: The aurora kinase inhibitors AZD1152-HQPA and ZM447439 induced growth arrest and the accumulation of hyperploid cells in acute myeloid leukemia cell lines and primary acute myeloid leukemia cultures. Furthermore, both agents inhibited histone H3 phosphorylation and this preceded perturbations in cell cycle and the induction of apoptosis. Single cell cloning assays were performed on diploid and polyploid cells to investigate their colony-forming capacities. Although the polyploid cells showed a reduced capacity for colony formation when compared with their diploid counterparts, they were consistently able to form colonies.
CONCLUSIONS: AZD1152-HQPA- and ZM447439 are effective apoptosis-inducing agents in acute myeloid leukemia cell lines and primary acute myeloid leukemia cultures. However, their propensity to induce polyploidy does not inevitably result in apoptosis.

PMID: 18367484 [PubMed - indexed for MEDLINE]

chir-258 dovitinib dna-pk

Zwint-1 is a novel Aurora B substrate required for the assembly of a dynein-binding platform on kinetochores.

Zwint-1 is a novel Aurora B substrate required for the assembly of a dynein-binding platform on kinetochores.

Mol Biol Cell. 2011 Sep;22(18):3318-30

Authors: Kasuboski JM, Bader JR, Vaughan PS, Tauhata SB, Winding M, Morrissey MA, Joyce MV, Boggess W, Vos L, Chan GK, Hinchcliffe EH, Vaughan KT

Abstract
Aurora B (AurB) is a mitotic kinase responsible for multiple aspects of mitotic progression, including assembly of the outer kinetochore. Cytoplasmic dynein is an abundant kinetochore protein whose recruitment to kinetochores requires phosphorylation. To assess whether AurB regulates recruitment of dynein to kinetochores, we inhibited AurB using ZM447439 or a kinase-dead AurB construct. Inhibition of AurB reduced accumulation of dynein at kinetochores substantially; however, this reflected a loss of dynein-associated proteins rather than a defect in dynein phosphorylation. We determined that AurB inhibition affected recruitment of the ROD, ZW10, zwilch (RZZ) complex to kinetochores but not zwint-1 or more-proximal kinetochore proteins. AurB phosphorylated zwint-1 but not ZW10 in vitro, and three novel phosphorylation sites were identified by tandem mass spectrometry analysis. Expression of a triple-Ala zwint-1 mutant blocked kinetochore assembly of RZZ-dependent proteins and induced defects in chromosome movement during prometaphase. Expression of a triple-Glu zwint-1 mutant rendered cells resistant to AurB inhibition during prometaphase. However, cells expressing the triple-Glu mutant failed to satisfy the spindle assembly checkpoint (SAC) at metaphase because poleward streaming of dynein/dynactin/RZZ was inhibited. These studies identify zwint-1 as a novel AurB substrate required for kinetochore assembly and for proper SAC silencing at metaphase.

PMID: 21775627 [PubMed - indexed for MEDLINE]

c-met inhibitors zm-447439 rad001

Short and long-term tumor cell responses to Aurora kinase inhibitors.

Short and long-term tumor cell responses to Aurora kinase inhibitors.

Exp Cell Res. 2009 Apr 15;315(7):1085-99

Authors: Dreier MR, Grabovich AZ, Katusin JD, Taylor WR

Abstract
Aurora kinases are essential for mitosis and are candidate targets of novel chemotherapeutic agents. The inhibitors ZM447439, MK-0457 (VX-680) as well as Hesperadin have been used to dissect the roles of Aurora kinases in the cell cycle and have been tested clinically for the treatment of cancer. Here we have carried out a detailed kinetic analysis of two isogenic cell lines differing in p53 function and have compared the effects of ZM447439 and VE-465 (related to MK-0457). We find that p53 is needed for efficient cell cycle arrest when Aurora kinases are inhibited by either ZM447439 or VE-465. However, the p53-induced cell cycle block is neither immediate nor absolute. ZM447439 induced the localized accumulation of gammaH2A.X indicating that p53 induction by this drug occurs in response to DNA damage. Our analysis of the long-term effects of ZM447439 indicates that cells can evade killing by the drug, but not via a classical drug-resistance mechanism. Several mechanisms to explain how cells may evade killing by Aurora kinase inhibitors are described.

PMID: 19233169 [PubMed - indexed for MEDLINE]

rad001 ecdysone chir-258

2012年10月23日星期二

Aurora kinase B, epigenetic state of centromeric heterochromatin and chiasma resolution in oocytes.

Aurora kinase B, epigenetic state of centromeric heterochromatin and chiasma resolution in oocytes.

Reprod Biomed Online. 2009 Sep;19(3):352-68

Authors: Vogt E, Kipp A, Eichenlaub-Ritter U

Abstract
Aurora kinases comprise a family of phosphoproteins performing multiple functions in mitosis and meiosis. Because Aurora kinase B (AURKB) expression is altered in aged oocytes and there is only limited information on its function in meiosis, it was decided to study the spatial distribution and co-localization of AURKB with other regulatory proteins at centromeres during mouse oocyte maturation. AURKB associates with chromosomes after germinal vesicle breakdown, is enriched at centromeres from prometaphase I and transits to the spindle midzone at late anaphase I. Preferential inhibition of AURKB by low concentrations of ZM 447439 inhibitor prevents polar body formation and affects spindle formation and chromosome congression at meiosis I, associated with expression of BubR1 checkpoint protein at kinetochores. Release of cohesion between sister chromatids appears inhibited resulting in failure of chiasma resolution in oocytes progressing to anaphase I. Concomitantly, the inhibitor reduces histone H3 lysine 9 trimethylation at centromeric heterochromatin and affects chromosome condensation. The cytokinesis arrest protects young, healthy oocytes from errors in chromosome segregation although increasing polyploidy. This study shows that changes in activity of AURKB may increase risks for chromosome non-disjunction and aneuploidy in mammalian oocytes, irrespective of age.

PMID: 19778480 [PubMed - indexed for MEDLINE]

dna-pk coxinhibitors c-met inhibitors

Effects of the aurora kinase inhibitors AZD1152-HQPA and ZM447439 on growth arrest and polyploidy in acute myeloid leukemia cell lines and primary blasts.

Effects of the aurora kinase inhibitors AZD1152-HQPA and ZM447439 on growth arrest and polyploidy in acute myeloid leukemia cell lines and primary blasts.

Haematologica. 2008 May;93(5):662-9

Authors: Walsby E, Walsh V, Pepper C, Burnett A, Mills K

PMID: 18367484 [PubMed - indexed for MEDLINE]

dna-pk coxinhibitors c-met inhibitors

MAPK interacts with XGef and is required for CPEB activation during meiosis in Xenopus oocytes.

MAPK interacts with XGef and is required for CPEB activation during meiosis in Xenopus oocytes.

J Cell Sci. 2007 Mar 15;120(Pt 6):1093-103

Authors: Keady BT, Kuo P, Mart�nez SE, Yuan L, Hake LE

PMID: 17344432 [PubMed - indexed for MEDLINE]

zm-447439 rad001 ecdysone

Zwint-1 is a novel Aurora B substrate required for the assembly of a dynein-binding platform on kinetochores.

Zwint-1 is a novel Aurora B substrate required for the assembly of a dynein-binding platform on kinetochores.

Mol Biol Cell. 2011 Sep;22(18):3318-30

Authors: Kasuboski JM, Bader JR, Vaughan PS, Tauhata SB, Winding M, Morrissey MA, Joyce MV, Boggess W, Vos L, Chan GK, Hinchcliffe EH, Vaughan KT

PMID: 21775627 [PubMed - indexed for MEDLINE]

c-met inhibitors zm-447439 rad001

Aurora kinase inhibitor ZM447439 blocks chromosome-induced spindle assembly, the completion of chromosome condensation, and the establishment of the spindle integrity checkpoint in Xenopus egg extracts.

Aurora kinase inhibitor ZM447439 blocks chromosome-induced spindle assembly, the completion of chromosome condensation, and the establishment of the spindle integrity checkpoint in Xenopus egg extracts.

Mol Biol Cell. 2005 Mar;16(3):1305-18

Authors: Gadea BB, Ruderman JV

Abstract
The Aurora family kinases contribute to accurate progression through several mitotic events. ZM447439 ("ZM"), the first Aurora family kinase inhibitor to be developed and characterized, was previously found to interfere with the mitotic spindle integrity checkpoint and chromosome segregation. Here, we have used extracts of Xenopus eggs, which normally proceed through the early embryonic cell cycles in the absence of functional checkpoints, to distinguish between ZM's effects on the basic cell cycle machinery and its effects on checkpoints. ZM clearly had no effect on either the kinetics or amplitude in the oscillations of activity of several key cell cycle regulators. It did, however, have striking effects on chromosome morphology. In the presence of ZM, chromosome condensation began on schedule but then failed to progress properly; instead, the chromosomes underwent premature decondensation during mid-mitosis. ZM strongly interfered with mitotic spindle assembly by inhibiting the formation of microtubules that are nucleated/stabilized by chromatin. By contrast, ZM had little effect on the assembly of microtubules by centrosomes at the spindle poles. Finally, under conditions where the spindle integrity checkpoint was experimentally induced, ZM blocked the establishment, but not the maintenance, of the checkpoint, at a point upstream of the checkpoint protein Mad2. These results show that Aurora kinase activity is required to ensure the maintenance of condensed chromosomes, the generation of chromosome-induced spindle microtubules, and activation of the spindle integrity checkpoint.

PMID: 15616188 [PubMed - indexed for MEDLINE]

coxinhibitors c-met inhibitors zm-447439

2012年10月22日星期一

Determinants for the efficiency of anticancer drugs targeting either Aurora-A or Aurora-B kinases in human colon carcinoma cells.

Determinants for the efficiency of anticancer drugs targeting either Aurora-A or Aurora-B kinases in human colon carcinoma cells.

Mol Cancer Ther. 2009 Jul;8(7):2046-56

Authors: Kaestner P, Stolz A, Bastians H

Abstract
The mitotic Aurora kinases, including Aurora-A and Aurora- B, are attractive novel targets for anticancer therapy, and inhibitory drugs have been developed that are currently undergoing clinical trials. However, the molecular mechanisms how these drugs induce tumor cell death are poorly understood. We have addressed this question by comparing the requirements for an efficient induction of apoptosis in response to MLN8054, a selective inhibitor of Aurora-A, and the selective Aurora-B inhibitor ZM447439 in human colon carcinoma cells. By using various isogenic knockout as well as inducible colon carcinoma cell lines, we found that treatment with MLN8054 induces defects in mitotic spindle assembly, which causes a transient spindle checkpoint-dependent mitotic arrest. This cell cycle arrest is not maintained due to the activity of MLN8054 to override the spindle checkpoint. Subsequently, MLN8054-treated cells exit from mitosis and activate a p53-dependent postmitotic G(1) checkpoint, which subsequently induces p21 and Bax, leading to G(1) arrest followed by the induction of apoptosis. In contrast, inhibition of Aurora-B by ZM447439 also interferes with normal chromosome alignment during mitosis and overrides the mitotic spindle checkpoint but allows a subsequent endoreduplication, although ZM447439 potently activates the p53-dependent postmitotic G(1) checkpoint. Moreover, the ZM447439-induced endoreduplication is a prerequisite for the efficiency of the drug. Thus, our results obtained in human colon carcinoma cells indicate that although both Aurora kinase inhibitors are potent inducers of tumor cell death, the pathways leading to the induction of apoptosis in response to these drugs are distinct.

PMID: 19584233 [PubMed - indexed for MEDLINE]

c-met inhibitors zm-447439 rad001

Aurora kinase B modulates chromosome alignment in mouse oocytes.

Aurora kinase B modulates chromosome alignment in mouse oocytes.

Mol Reprod Dev. 2009 Nov;76(11):1094-105

Authors: Shuda K, Schindler K, Ma J, Schultz RM, Donovan PJ

Abstract
The elevated incidence of aneuploidy in human oocytes warrants study of the molecular mechanisms regulating proper chromosome segregation. The Aurora kinases are a well-conserved family of serine/threonine kinases that are involved in proper chromosome segregation during mitosis and meiosis. Here we report the expression and localization of all three Aurora kinase homologs, AURKA, AURKB, and AURKC, during meiotic maturation of mouse oocytes. AURKA, the most abundantly expressed homolog, localizes to the spindle poles during meiosis I (MI) and meiosis II (MII), whereas AURKB is concentrated at kinetochores, specifically at metaphase of MI (Met I). The germ cell-specific homolog, AURKC, is found along the entire length of chromosomes during both meiotic divisions. Maturing oocytes in the presence of the small molecule pan-Aurora kinase inhibitor, ZM447439 results in defects in meiotic progression and chromosome alignment at both Met I and Met II. Over-expression of AURKB, but not AURKA or AURKC, rescues the chromosome alignment defect suggesting that AURKB is the primary Aurora kinase responsible for regulating chromosome dynamics during meiosis in mouse oocytes.

PMID: 19565641 [PubMed - indexed for MEDLINE]

coxinhibitors c-met inhibitors zm-447439

Trivalent dimethylarsenic compound induces histone H3 phosphorylation and abnormal localization of Aurora B kinase in HepG2 cells.

Trivalent dimethylarsenic compound induces histone H3 phosphorylation and abnormal localization of Aurora B kinase in HepG2 cells.

Toxicol Appl Pharmacol. 2009 Dec 15;241(3):275-82

Authors: Suzuki T, Miyazaki K, Kita K, Ochi T

Abstract
Trivalent dimethylarsinous acid [DMA(III)] has been shown to induce mitotic abnormalities, such as centrosome abnormality, multipolar spindles, multipolar division, and aneuploidy, in several cell lines. In order to elucidate the mechanisms underlying these mitotic abnormalities, we investigated DMA(III)-mediated changes in histone H3 phosphorylation and localization of Aurora B kinase, which is a key molecule in cell mitosis. DMA(III) caused the phosphorylation of histone H3 (ser10) and was distributed predominantly in mitotic cells, especially in prometaphase cells. By contrast, most of the phospho-histone H3 was found to be localized in interphase cells after treatment with inorganic arsenite [iAs(III)], suggesting the involvement of a different pathway in phosphorylation. DMA(III) activated Aurora B kinase and slightly activated ERK MAP kinase. Phosphorylation of histone H3 by DMA(III) was effectively reduced by ZM447439 (Aurora kinase inhibitor) and slightly reduced by U0126 (MEK inhibitor). By contrast, iAs(III)-dependent histone H3 phosphorylation was markedly reduced by U0126. Aurora B kinase is generally localized in the midbody during telophase and plays an important role in cytokinesis. However, in some cells treated with DMA(III), Aurora B was not localized in the midbody of telophase cells. These findings suggested that DMA(III) induced a spindle abnormality, thereby activating the spindle assembly checkpoint (SAC) through the Aurora B kinase pathway. In addition, cytokinesis was not completed because of the abnormal localization of Aurora B kinase by DMA(III), thereby resulting in the generation of multinucleated cells. These results provide insight into the mechanism of arsenic tumorigenesis.

PMID: 19716834 [PubMed - indexed for MEDLINE]

dna-pk coxinhibitors c-met inhibitors

Aurora B couples chromosome alignment with anaphase by targeting BubR1, Mad2, and Cenp-E to kinetochores.

Aurora B couples chromosome alignment with anaphase by targeting BubR1, Mad2, and Cenp-E to kinetochores.

J Cell Biol. 2003 Apr 28;161(2):267-80

Authors: Ditchfield C, Johnson VL, Tighe A, Ellston R, Haworth C, Johnson T, Mortlock A, Keen N, Taylor SS

PMID: 12719470 [PubMed - indexed for MEDLINE]

rad001 ecdysone chir-258

2012年10月21日星期日

ZM447439, a novel promising aurora kinase inhibitor, provokes antiproliferative and proapoptotic effects alone and in combination with bio- and chemotherapeutic agents in gastroenteropancreatic neuroendocrine tumor cell lines.

ZM447439, a novel promising aurora kinase inhibitor, provokes antiproliferative and proapoptotic effects alone and in combination with bio- and chemotherapeutic agents in gastroenteropancreatic neuroendocrine tumor cell lines.

Neuroendocrinology. 2010;91(2):121-30

Authors: Georgieva I, Koychev D, Wang Y, Holstein J, Hopfenm�ller W, Zeitz M, Grabowski P

Abstract
Background: Therapeutic approaches to gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are still not satisfactory. A new direction in treatment options could be the novel aurora kinase inhibitor ZM447439, which was previously reported to interfere with the mitotic spindle integrity checkpoint and chromosome segregation, but does not interfere with other kinases when used up to 5 muM. Methods: We evaluated the antineoplastic effects of ZM447439 on growth and apoptosis of the GEP-NET cell lines BON, QGP-1 and MIP-101, representing the different malignant tumor types, using standard cell biological tests as crystal violet assays, caspase activation, DNA fragmentation and cell cycle analysis. Results: ZM447439 dose-dependently inhibited proliferation of all three cell lines with IC(50) values in the nanomolar to low micromolar range. Moreover, aurora kinase inhibition by ZM447439 potently induced apoptosis, which was accompanied by DNA fragmentation and caspase 3 and 7 activation. Furthermore, we observed cell cycle arrest at G(0)/G(1) phase as well as a block in G(2)/M transition. In addition, combined treatment with the chemotherapeutic agents streptozocin and cisplatin augmented significantly the antiproliferative effects of those agents. Conclusion: Aurora kinase inhibition by ZM447439 seems to be a promising new therapeutic approach in GEP-NETs, which should be evaluated in further clinical trials.

PMID: 19923785 [PubMed - indexed for MEDLINE]

dovitinib dna-pk coxinhibitors

Aurora kinase B, epigenetic state of centromeric heterochromatin and chiasma resolution in oocytes.

Aurora kinase B, epigenetic state of centromeric heterochromatin and chiasma resolution in oocytes.

Reprod Biomed Online. 2009 Sep;19(3):352-68

Authors: Vogt E, Kipp A, Eichenlaub-Ritter U

PMID: 19778480 [PubMed - indexed for MEDLINE]

c-met inhibitors zm-447439 rad001

ZM 447439 inhibition of aurora kinase induces Hep2 cancer cell apoptosis in three-dimensional culture.

ZM 447439 inhibition of aurora kinase induces Hep2 cancer cell apoptosis in three-dimensional culture.

Cell Cycle. 2008 May 15;7(10):1473-9

Authors: Long ZJ, Xu J, Yan M, Zhang JG, Guan Z, Xu DZ, Wang XR, Yao J, Zheng FM, Chu GL, Cao JX, Zeng YX, Liu Q

Abstract
Mitotic Aurora kinases are essential for accurate chromosome segregation during cell division. Forced overexpression of Aurora kinase results in centrosome amplification and multipolar spindles, causing aneuploidy, a hallmark of cancer. ZM447439 (ZM), an Aurora selective ATP-competitive inhibitor, interferes with the spindle integrity checkpoint and chromosome segregation. Here, we showed that inhibition of Aurora kinase by ZM reduced histone H3 phosphorylation at Ser10 in Hep2 carcinoma cells. Multipolar spindles were induced in these ZM-treated G(2)/M-arrested cells with accumulation of 4N/8N DNA, similar to cells with genetically suppressed Aurora-B. Cells subsequently underwent apoptosis, as assessed by cleavage of critical apoptotic associated protein PARP. Hep2 cells formed a tumor-like cell mass in 3-dimensional matrix culture; inhibition of Aurora kinase by ZM either destructed the preformed cell mass or prevented its formation, by inducing apoptotic cell death as stained for cleaved caspase-3. Lastly, ZM inhibition of Aurora kinase was potently in association with decrease of Akt phosphorylation at Ser473 and its substrates GSK3alpha/beta phosphorylation at Ser21 and Ser9. Together, we demonstrated that Aurora kinase served as a potential molecular target of ZM for more selective therapeutic cancer treatment.

PMID: 18418083 [PubMed - indexed for MEDLINE]

coxinhibitors c-met inhibitors zm-447439

Dawn of Aurora kinase inhibitors as anticancer drugs.

Dawn of Aurora kinase inhibitors as anticancer drugs.

Expert Opin Investig Drugs. 2004 Sep;13(9):1199-201

Authors: Doggrell SA

Abstract
With the current standard chemotherapy regimens only approximately 25% of acute myelogenous leukaemia (AML) patients survive > 5 years. Aurora kinases are overexpressed in many human cancers. VX-680 inhibited Aurora-A, -B, -C and the FMS-like tyrosine kinase-3 with apparent inhibitory constants of 0.6, 18, 4.6 and 30 nM, respectively. In primary leukaemia cells from patients with AML, which were refractory to standard therapies, VX-680 inhibited colony formation. In nude mice, VX-680 markedly reduced human AML tumours. The development of VX-680 for use in AML should continue.

PMID: 15330750 [PubMed - indexed for MEDLINE]

dovitinib dna-pk coxinhibitors

[Inhibitors of aurora kinases].

[Inhibitors of aurora kinases].

Ann Pharm Fr. 2009 Mar;67(2):69-77

Authors: Pinel S, Barbault-Foucher S, Lott-Desroches MC, Astier A

Abstract
Aurora kinases (A, B and C) are proteins expressed only in cells which divide actively and their increase is a factor of bad prognosis in cancer. They regulate the maturation of centrosomes, the separation and the condensation of chromosomes, mitotic checkpoint and cytokinesis. The inhibition of aurora kinases, by powerful and selective inhibitors, is due to the formation of abnormal cells which are eliminated by apoptosis. The purpose of this article is to present the role, the antitumor activity and the tolerability of these inhibitors. They can be administered orally or intravenously, on weekly or monthly schedules. In our knowledge, twelve molecules are evaluated at the present time and will be discussed only the most advanced namely: VX-680, ZM 447439, MLN 8054, AZD 1152, PHA 739358, SU 6668 and AT 9283. The main indications are breast, colon, lung, pancreas and bladder cancers as well as hematologic tumors such as leukemia (ALL, AML, CML) and lymphoma. These inhibitors can be associated with other chemotherapies. They seem well tolerated; the reported side effects are digestive disorders (diarrhea), fever, asthenia, alopecia, slumber, neutropenia, myelosuppression and disturbance of the biological markers.

PMID: 19298889 [PubMed - indexed for MEDLINE]

coxinhibitors c-met inhibitors zm-447439

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