5-alpha-reductase: 2012-10-14

2012年10月20日星期六

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]

coxinhibitors c-met inhibitors zm-447439

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

Aurora kinase family: a new target for anticancer drug.

Aurora kinase family: a new target for anticancer drug.

Recent Pat Anticancer Drug Discov. 2008 Jun;3(2):114-22

Authors: Macarulla T, Ramos FJ, Tabernero J

Abstract
Aurora kinases (AK) are the name given to a family of Serine/threonine (Ser/Thr) protein kinases. These proteins represent a novel family of kinases crucial for cell cycle control. The cell division process is one of the hallmarks of every living organism. Within the complete cell-cycle process, mitosis constitutes one of the most critical steps. The main purpose of mitosis is to segregate sister chromatics into two daughters cells. It is a complex biologic process, and errors in this mechanism can lead to genomic instability, a condition associated with tumorigenesis. This process is tightly regulated by several proteins, some of them acting as check-points that ultimately ensure the correct temporal and spatial coordination of this critical biologic process. Among this network of mitotic regulators, AK play a critical role in cellular division by controlling chromatid segregation. Three AK family members have been identified in mammalian cells: A, B, and C. These proteins are implicated in several vital events in mitosis. In experimental models, overexpression of AK can induce spindle defects, chromosome mis-segregation, and malignant transformation. Conversely, downregulation of AK expression cause mitotic arrest and apoptosis in tumor cell lines. The expression levels of human AK are increased in certain types of cancer including breast, colon, pancreatic, ovarian, and gastric tumors. This observation has lent an interest to this family of kinases as potential drug targets for development of new anticancer therapies. This review focuses in recent progress in the role of AK in tumorogenesis and the development of new anticancer drug against AK proteins. This manuscript also includes some relevant patents as well.

PMID: 18537754 [PubMed - indexed for MEDLINE]

chir-258 dovitinib dna-pk

New Insights into the Management of Renal Cell Cancer.

New Insights into the Management of Renal Cell Cancer.

Oncology. 2012 Oct 16;84(1):22-31

Authors: P�cuchet N, Fournier LS, Oudard S

Abstract
Kidney cancer is composed of several bio-histological entities. The most frequent type, clear-cell carcinoma, is not homogenous regarding gene mutations or transcriptomic profiles, but the biologic classifications are not yet mature. Therefore, biologically driven strategies of treatment have not yet been developed in the clinical setting. The choice of first-line agent currently depends on the prognostic criteria published by Motzer et al. [J Clin Oncol 1999;17:2530-2540] and recently by Heng et al. [J Clin Oncol 2009;27:5794-5799], with anti-vascular endothelial growth factor (VEGF) therapies for good- or intermediate-prognosis groups and anti-mammalian target of rapamycin (mTOR) for poor-risk patients. In the past years, biological changes leading to resistance to targeted agents have been widely investigated. Discoveries resulted in the development of second-generation VEGF receptor tyrosine kinase inhibitors, characterized by an improved potency and selectivity. Besides, co-inhibition of signalling pathways mediating resistance to anti-VEGF are being developed targeting fibroblast growth factor and c-Met. Dual mTOR/phosphatidylinositol 3-kinase inhibitors have greater efficacy than rapalogs in preclinical models and are being investigated in early clinical trials. In conclusion, the changing landscape in the biology and treatment of kidney cancer offers new opportunities for clinicians to treat patients, but, due to relatively high costs, the use of targeted therapies will likely be strongly controlled by health authorities.

PMID: 23076127 [PubMed - as supplied by publisher]

c-met inhibitors zm-447439 rad001

Histone post-translational modification: from discovery to the clinic.

Histone post-translational modification: from discovery to the clinic.

IDrugs. 2006 Jun;9(6):398-401

Authors: Thomas NR

PMID: 16752306 [PubMed - indexed for MEDLINE]

coxinhibitors c-met inhibitors zm-447439

2012年10月19日星期五

The effects of the selective cyclooxygenase-2 inhibitor on endometrial cytological findings in uterine endometrial cancer patients.

The effects of the selective cyclooxygenase-2 inhibitor on endometrial cytological findings in uterine endometrial cancer patients.

Acta Cytol. 2012;56(4):394-400

Authors: Hasegawa K, Kawamura K, Kato R, Komiyama S, Kaneko C, Udagawa Y

Abstract
OBJECTIVE: We previously reported that oral administration of the selective cyclooxygenase-2 (COX-2) inhibitor etodolac results in antitumor effects in endometrial cancer tissue. Herein, we investigated whether these antitumor effects could be assessed using endometrial cytological findings.
STUDY DESIGN: Etodolac (400 mg b.i.d. for 2 weeks) was administered preoperatively to 21 endometrial cancer patients: 16 had COX-2-positive disease and 5 had COX-2-negative disease. Twenty-one pairs of pre- and post-etodolac-treatment endometrial cytological samples were collected to review changes in the cytological features.
RESULTS: In the COX-2-positive patients, nuclear atypia was slightly decreased in 3 of the 16 cases, while the mitotic index was decreased in all cases. Cellular overlapping and tumor cell cluster outlines were somewhat affected in 6 and 8 cases, respectively. Nuclear/cytoplasmic ratio, anisokaryosis and hyperchromasia were also reduced in 6, 4, and 2 cases, respectively; however, tumor diathesis and nucleoli features were unchanged. In contrast, endometrial cytological features did not appear to be affected in the 5 COX-2-negative patients.
CONCLUSIONS: We conclude that the antitumor effects observed in endometrial cancer tissues following oral administration of etodolac are reflected in and can be easily assessed by evaluating endometrial cytological features.

PMID: 22846758 [PubMed - indexed for MEDLINE]

rad001 ecdysone chir-258

Aurora kinase inhibitor ZM447439 induces apoptosis via mitochondrial pathways.

Aurora kinase inhibitor ZM447439 induces apoptosis via mitochondrial pathways.

Biochem Pharmacol. 2010 Jan 15;79(2):122-9

Authors: Li M, Jung A, Ganswindt U, Marini P, Friedl A, Daniel PT, Lauber K, Jendrossek V, Belka C

Abstract
ZM447439 (ZM) is a potent and selective inhibitor of aurora-A and -B kinase with putative anti-tumoral activity. Inhibitors of aurora kinases were shown to induce apoptosis in vitro and in vivo. To investigate the underlying mechanisms, cell death pathways triggered by ZM was analysed in HCT-116 colorectal cancer cells. Through correlation of polyploidization and apoptosis in different knockout cells, the interrelation of these cellular responses to ZM was investigated. ZM induced apoptosis in a concentration- and time-dependent manner. ZM-induced apoptosis was associated with an upregulation of p53, breakdown of the mitochondrial membrane potential (DeltaPsim) and activation of caspase-3. To precisely define key components for ZM-induced apoptosis, knockout cells lacking p53, Bak, Bax or both Bak and Bax were used. Lack of p53 reduced ZM-induced apoptosis and breakdown of DeltaPsim, while lack of Bak, Bax or both almost completely inhibited apoptosis and breakdown of DeltaPsim. Since no difference in apoptosis induction was detectable between HCT-116 cells lacking Bak, Bax or both, apoptosis induction depended non-redundantly on both Bak and Bax. Phenomenally, ZM induced notable polyploidization in all examined cells, especially in p53-/- cells. A correlation between polyploidization and apoptosis was observed in wild-type, and also in p53-/- cells, albeit with a modest extent of apoptosis. Moreover, in Bak-/-, Bax-/- and Bak/Bax-/- cells apoptosis was totally inhibited in spite of the strongest polyploidization, suggesting apoptosis may be a secondary event following polyploidization in HCT-116 cells. Thus ZM-induced apoptosis depends not only on polyploidization, but also on the intracellular apoptotic signaling.

PMID: 19686703 [PubMed - indexed for MEDLINE]

c-met inhibitors zm-447439 rad001

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]

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]

dna-pk coxinhibitors c-met inhibitors

Analysis of mitotic phosphorylation of borealin.

Analysis of mitotic phosphorylation of borealin.

BMC Cell Biol. 2007;8:5

Authors: Kaur H, Stiff AC, Date DA, Taylor WR

Abstract
BACKGROUND: The main role of the chromosomal passenger complex is to ensure that Aurora B kinase is properly localized and activated before and during mitosis. Borealin, a member of the chromosomal passenger complex, shows increased expression during G2/M phases and is involved in targeting the complex to the centromere and the spindle midzone, where it ensures proper chromosome segregation and cytokinesis. Borealin has a consensus CDK1 phosphorylation site, threonine 106 and can be phosphorylated by Aurora B Kinase at serine 165 in vitro.
RESULTS: Here, we show that Borealin is phosphorylated during mitosis in human cells. Dephosphorylation of Borealin occurs as cells exit mitosis. The phosphorylated form of Borealin is found in an INCENP-containing complex in mitosis. INCENP-containing complexes from cells in S phase are enriched in the phosphorylated form suggesting that phosphorylation may encourage entry of Borealin into the chromosomal passenger complex. Although Aurora B Kinase is found in complexes that contain Borealin, it is not required for the mitotic phosphorylation of Borealin. Mutation of T106 or S165 of Borealin to alanine does not alter the electrophoretic mobility shift of Borealin. Experiments with cyclohexamide and the phosphatase inhibitor sodium fluoride suggest that Borealin is phosphorylated by a protein kinase that can be active in interphase and mitosis and that the phosphorylation may be regulated by a short-lived phosphatase that is active in interphase but not mitosis.
CONCLUSION: Borealin is phosphorylated during mitosis. Neither residue S165, T106 nor phosphorylation of Borealin by Aurora B Kinase is required to generate the mitotic, shifted form of Borealin. Suppression of phosphorylation during interphase is ensured by a labile protein, possibly a cell cycle regulated phosphatase.

PMID: 17241471 [PubMed - indexed for MEDLINE]

c-met inhibitors zm-447439 rad001

2012年10月18日星期四

Ecdysone Control of Developmental Transitions: Lessons from Drosophila Research.

Ecdysone Control of Developmental Transitions: Lessons from Drosophila Research.

Annu Rev Entomol. 2012 Oct 15;

Authors: Yamanaka N, Rewitz KF, O'Connor MB

Abstract
The steroid hormone ecdysone is the central regulator of insect developmental transitions. Recent new advances in our understanding of ecdysone action have relied heavily on the application of Drosophila melanogaster molecular genetic tools to study insect metamorphosis. In this review, we focus on three major aspects of Drosophila ecdysone biology: (a) factors that regulate the timing of ecdysone release, (b) molecular basis of stage- and tissue-specific responses to ecdysone, and (c) feedback regulation and coordination of ecdysone signaling. Expected final online publication date for the Annual Review of Entomology Volume 58 is December 03, 2013. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.

PMID: 23072462 [PubMed - as supplied by publisher]

chir-258 dovitinib dna-pk

Sensitivity of BRCA2 mutated human cell lines to Aurora kinase inhibition.

Sensitivity of BRCA2 mutated human cell lines to Aurora kinase inhibition.

Invest New Drugs. 2012 Apr;30(2):425-34

Authors: Vidarsdottir L, Steingrimsdottir G, Bodvarsdottir SK, Ogmundsdottir HM, Eyfjord JE

Abstract
Aurora kinases play a vital part in successful mitosis and cell division. Aberrant Aurora-A and -B expression is commonly seen in various types of tumors. Small molecule Aurora inhibitors have already entered clinical trials. Aurora-A amplification has been shown to be associated with breast tumors from BRCA2-mutation carriers and such patients might therefore be candidates for treatment with Aurora kinase inhibitors. There is a need to identify markers that can predict sensitivity to Aurora inhibition. In this study sensitivity to the inhibitor ZM447439 was tested on a panel of 15 non-malignant and malignant epithelial cell lines that differed with respect to BRCA2 and p53 status and related to level of Aurora kinase expression. The IC(50) value for cell survival ranged from 1.9-8.1 ?M and was not related to presence or absence of BRCA2 mutation. The levels of Aurora-A and -B expression correlated with each other but sensitivity towards ZM447439 did not correlate with levels of Aurora-A and -B mRNA expression, alone. Cells treated with the Aurora kinase inhibitor completed mitosis but cytokinesis was inhibited resulting in polyploidy and multinucleation. Different levels of polyploidy could not be fully explained by defects in p53. Only cell lines with a combination of high Aurora-A and -B expression, BRCA2 mutation and p53 defects showed more sensitivity towards Aurora inhibition than other cell lines. In conclusion, BRCA2-mutated cells showed variable sensitivity towards Aurora kinase inhibition. The level of sensitivity could not be predicted by Aurora expression levels alone but BRCA2 mutated tumors with high Aurora expression and non-functional p53 are likely candidates for treatment with Aurora inhibitors.

PMID: 20960027 [PubMed - indexed for MEDLINE]

rad001 ecdysone chir-258

Inhibition of Aurora kinases perturbs chromosome alignment and spindle checkpoint signaling in rat spermatocytes.

Inhibition of Aurora kinases perturbs chromosome alignment and spindle checkpoint signaling in rat spermatocytes.

Exp Cell Res. 2006 Nov 1;312(18):3459-70

Authors: Wang Y, Toppari J, Parvinen M, Kallio MJ

Abstract
In somatic cells, integrity of cell division is safeguarded by the spindle checkpoint, a signaling cascade that delays the separation of sister chromatids in the presence of misaligned chromosomes. Aurora kinases play important roles in this process by promoting centrosome maturation, chromosome bi-orientation, spindle checkpoint signaling, and cytokinesis. To investigate the functions of Aurora kinases in male meiosis, we applied a small molecule Aurora inhibitor, ZM447439, to seminiferous tubules in vitro. Primary and secondary spermatocytes exposed to ZM447439 exhibit defects in the spindle morphology and fail to align their chromosomes at the metaphase plate. Moreover, the treated spermatocytes undergo a forced exit from the meiotic M-phase without cytokinesis. These results suggest that the activities of Aurora kinases are required for normal spindle assembly as well as for establishment and maintenance of proper microtubule-kinetochore attachments and spindle checkpoint signaling in male mammalian meiosis.

PMID: 16962097 [PubMed - indexed for MEDLINE]

zm-447439 rad001 ecdysone

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]

zm-447439 rad001 ecdysone

[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]

dovitinib dna-pk coxinhibitors

2012年10月17日星期三

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]

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Validating Aurora B as an anti-cancer drug target.

Validating Aurora B as an anti-cancer drug target.

J Cell Sci. 2006 Sep 1;119(Pt 17):3664-75

Authors: Girdler F, Gascoigne KE, Eyers PA, Hartmuth S, Crafter C, Foote KM, Keen NJ, Taylor SS

Abstract
The Aurora kinases, a family of mitotic regulators, have received much attention as potential targets for novel anti-cancer therapeutics. Several Aurora kinase inhibitors have been described including ZM447439, which prevents chromosome alignment, spindle checkpoint function and cytokinesis. Subsequently, ZM447439-treated cells exit mitosis without dividing and lose viability. Because ZM447439 inhibits both Aurora A and B, we set out to determine which phenotypes are due to inhibition of which kinase. Using molecular genetic approaches, we show that inhibition of Aurora B kinase activity phenocopies ZM447439. Furthermore, a novel ZM compound, which is 100 times more selective for Aurora B over Aurora A in vitro, induces identical phenotypes. Importantly, inhibition of Aurora B kinase activity induces a penetrant anti-proliferative phenotype, indicating that Aurora B is an attractive anti-cancer drug target. Using molecular genetic and chemical-genetic approaches, we also probe the role of Aurora A kinase activity. We show that simultaneous repression of Aurora A plus induction of a catalytic mutant induces a monopolar phenotype. Consistently, another novel ZM-related inhibitor, which is 20 times as potent against Aurora A compared with ZM447439, induces a monopolar phenotype. Expression of a drug-resistant Aurora A mutant reverts this phenotype, demonstrating that Aurora A kinase activity is required for spindle bipolarity in human cells. Because small molecule-mediated inhibition of Aurora A and Aurora B yields distinct phenotypes, our observations indicate that the Auroras may present two avenues for anti-cancer drug discovery.

PMID: 16912073 [PubMed - indexed for MEDLINE]

dovitinib dna-pk coxinhibitors

Neither Aurora B activity nor histone H3 phosphorylation is essential for chromosome condensation during meiotic maturation of porcine oocytes.

Neither Aurora B activity nor histone H3 phosphorylation is essential for chromosome condensation during meiotic maturation of porcine oocytes.

Biol Reprod. 2006 May;74(5):905-12

Authors: Jel�nkov� L, Kubelka M

Abstract
Aurora kinase B (AURKB) is a chromosomal passenger protein that is essential for a number of processes during mitosis. Its activity is regulated by association with two other passenger proteins, INCENP and Survivin, and by phosphorylation on Thr 232. In this study, we examine expression and phosphorylation on Thr-232 of AURKB during meiotic maturation of pig oocytes in correlation with histone H3 phosphorylation and chromosome condensation. We show that histone H3 phosphorylation on Ser-10, but not on Ser-28, correlates with progressive chromosome condensation during oocyte maturation; Ser-10 phosphorylation starts around the time of the breakdown of the nuclear envelope, with the maximal activity in metaphase I, whereas Ser-28 phosphorylation does not significantly change in maturing oocytes. Treatment of oocytes with 50 microM butyrolactone I (BL-I), an inhibitor of cyclin-dependent kinases, or cycloheximide (10 microg/ml), inhibitor of proteosynthesis, results in a block of oocytes in the germinal vesicle stage, when nuclear membrane remains intact; however, condensed chromosome fibers or highly condensed chromosome bivalents can be seen in the nucleoplasm of BL-I- or cycloheximide-treated oocytes, respectively. In these treated oocytes, no or only very weak AURKB activity and phosphorylation of histone H3 on Ser-10 can be detected after 27 h of treatment, whereas phosphorylation on Ser-28 is not influenced. These results suggest that AURKB activity and Ser-10 phosphorylation of histone H3 are not required for chromosome condensation in pig oocytes, but might be required for further processing of chromosomes during meiosis.

PMID: 16452462 [PubMed - indexed for MEDLINE]

dna-pk coxinhibitors c-met inhibitors

Regulation of the meiotic prophase I to metaphase I transition in mouse spermatocytes.

Regulation of the meiotic prophase I to metaphase I transition in mouse spermatocytes.

Chromosoma. 2008 Oct;117(5):471-85

Authors: Sun F, Handel MA

Abstract
The meiotic prophase I to metaphase I transition (G2/MI) involves disassembly of synaptonemal complex (SC), chromatin condensation, and final compaction of morphologically distinct MI bivalent chromosomes. Control of these processes is poorly understood. The G2/MI transition was experimentally induced in mouse pachytene spermatocytes by okadaic acid (OA), and kinetic analysis revealed that disassembly of the central element of the SC occurred very rapidly after OA treatment, before histone H3 phosphorylation on Ser10. These events were followed by relocalization of SYCP3 and final condensation of bivalents. Enzymatic control of these G2/MI transition events was studied using small molecule inhibitors: butyrolactone I (BLI), an inhibitor of cyclin-dependent kinases (CDKs) and ZM447439 (ZM), an inhibitor of aurora kinases (AURKs). The formation of highly condensed MI bivalents and disassembly of the SC are regulated by both CDKs and AURKs. AURKs also mediate phosphorylation of histone H3 in meiosis. However, neither BLI nor ZM inhibited disassembly of the central element of the SC. Thus, despite evidence that the metaphase promoting factor is a universal regulator of the onset of cell division, desynapsis, the first and key step of the G2/MI transition, occurs independently of BLI-sensitive CDKs and ZM-sensitive AURKs.

PMID: 18563426 [PubMed - indexed for MEDLINE]

chir-258 dovitinib dna-pk

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]

zm-447439 rad001 ecdysone

2012年10月16日星期二

Cell cycle dependent degradation of MCAK: evidence against a role in anaphase chromosome movement.

Cell cycle dependent degradation of MCAK: evidence against a role in anaphase chromosome movement.

Cell Cycle. 2008 Oct;7(20):3187-93

Authors: Ganguly A, Bhattacharya R, Cabral F

Abstract
MCAK, a kinesin related motor protein with microtubule depolymerizing activity, is known to play an important role in spindle assembly and correcting errors in mitotic chromosome alignment. Experiments to determine how cellular levels of the protein are regulated demonstrate that MCAK accumulates during cell cycle progression, reaches a maximum at G(2)/M phase, and is rapidly degraded by the proteasome during mitosis. Immunofluorescence microscopy further indicates that MCAK largely disappears from kinetochores and spindle poles at the metaphase to anaphase transition. A phosphorylated form of MCAK appears during mitosis and seems to be preferentially degraded, but degradation does not appear to depend on Aurora B, a kinase reported to be involved in regulating the error correcting activity of the protein. These studies indicate that MCAK activity is limited during the latter stages of mitosis by protein degradation, and argue against a role for the protein in anaphase chromosome movement.

PMID: 18843200 [PubMed - indexed for MEDLINE]

coxinhibitors c-met inhibitors zm-447439

Analysis of mitotic phosphorylation of borealin.

Analysis of mitotic phosphorylation of borealin.

BMC Cell Biol. 2007;8:5

Authors: Kaur H, Stiff AC, Date DA, Taylor WR

PMID: 17241471 [PubMed - indexed for MEDLINE]

rad001 ecdysone chir-258

Neither Aurora B activity nor histone H3 phosphorylation is essential for chromosome condensation during meiotic maturation of porcine oocytes.

Neither Aurora B activity nor histone H3 phosphorylation is essential for chromosome condensation during meiotic maturation of porcine oocytes.

Biol Reprod. 2006 May;74(5):905-12

Authors: Jel�nkov� L, Kubelka M

PMID: 16452462 [PubMed - indexed for MEDLINE]

c-met inhibitors zm-447439 rad001

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]

zm-447439 rad001 ecdysone

2012年10月15日星期一

Systems kinomics demonstrates Congo Basin monkeypox virus infection selectively modulates host cell signaling responses as compared to West African monkeypox virus.

Systems kinomics demonstrates Congo Basin monkeypox virus infection selectively modulates host cell signaling responses as compared to West African monkeypox virus.

Mol Cell Proteomics. 2012 Jun;11(6):M111.015701

Authors: Kindrachuk J, Arsenault R, Kusalik A, Kindrachuk KN, Trost B, Napper S, Jahrling PB, Blaney JE

Abstract
Monkeypox virus (MPXV) is comprised of two clades: Congo Basin MPXV, with an associated case fatality rate of 10%, and Western African MPXV, which is associated with less severe infection and minimal lethality. We thus postulated that Congo Basin and West African MPXV would differentially modulate host cell responses and, as many host responses are regulated through phosphorylation independent of transcription or translation, we employed systems kinomics with peptide arrays to investigate these functional host responses. Using this approach we have demonstrated that Congo Basin MPXV infection selectively down-regulates host responses as compared with West African MPXV, including growth factor- and apoptosis-related responses. These results were confirmed using fluorescence-activated cell sorting analysis demonstrating that West African MPXV infection resulted in a significant increase in apoptosis in human monocytes as compared with Congo Basin MPXV. Further, differentially phosphorylated kinases were identified through comparison of our MPXV data sets and validated as potential targets for pharmacological inhibition of Congo Basin MPXV infection, including increased Akt S473 phosphorylation and decreased p53 S15 phosphorylation. Inhibition of Akt S473 phosphorylation resulted in a significant decrease in Congo Basin MPXV virus yield (261-fold) but did not affect West African MPXV. In addition, treatment with staurosporine, an apoptosis activator resulted in a 49-fold greater decrease in Congo Basin MPXV yields as compared with West African MPXV. Thus, using a systems kinomics approach, our investigation demonstrates that West African and Congo Basin MPXV differentially modulate host cell responses and has identified potential host targets of therapeutic interest.

PMID: 22205724 [PubMed - indexed for MEDLINE]

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Inhibition of Aurora kinases perturbs chromosome alignment and spindle checkpoint signaling in rat spermatocytes.

Inhibition of Aurora kinases perturbs chromosome alignment and spindle checkpoint signaling in rat spermatocytes.

Exp Cell Res. 2006 Nov 1;312(18):3459-70

Authors: Wang Y, Toppari J, Parvinen M, Kallio MJ

PMID: 16962097 [PubMed - indexed for MEDLINE]

c-met inhibitors zm-447439 rad001

Regulation of the meiotic prophase I to metaphase I transition in mouse spermatocytes.

Regulation of the meiotic prophase I to metaphase I transition in mouse spermatocytes.

Chromosoma. 2008 Oct;117(5):471-85

Authors: Sun F, Handel MA

PMID: 18563426 [PubMed - indexed for MEDLINE]

dovitinib dna-pk coxinhibitors

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

PMID: 15616188 [PubMed - indexed for MEDLINE]

chir-258 dovitinib dna-pk

Validating Aurora B as an anti-cancer drug target.

Validating Aurora B as an anti-cancer drug target.

J Cell Sci. 2006 Sep 1;119(Pt 17):3664-75

Authors: Girdler F, Gascoigne KE, Eyers PA, Hartmuth S, Crafter C, Foote KM, Keen NJ, Taylor SS

PMID: 16912073 [PubMed - indexed for MEDLINE]

zm-447439 rad001 ecdysone

2012年10月14日星期日

Molecular basis of drug resistance in aurora kinases.

Molecular basis of drug resistance in aurora kinases.

Chem Biol. 2008 Jun;15(6):552-62

Authors: Girdler F, Sessa F, Patercoli S, Villa F, Musacchio A, Taylor S

Abstract
Aurora kinases have emerged as potential targets in cancer therapy, and several drugs are currently undergoing preclinical and clinical validation. Whether clinical resistance to these drugs can arise is unclear. We exploited a hypermutagenic cancer cell line to select mutations conferring resistance to a well-studied Aurora inhibitor, ZM447439. All resistant clones contained dominant point mutations in Aurora B. Three mutations map to residues in the ATP-binding pocket that are distinct from the "gatekeeper" residue. The mutants retain wild-type catalytic activity and were resistant to all of the Aurora inhibitors tested. Our studies predict that drug-resistant Aurora B mutants are likely to arise during clinical treatment. Furthermore, because the plasticity of the ATP-binding pocket renders Aurora B insensitive to multiple inhibitors, our observations indicate that the drug-resistant Aurora B mutants should be exploited as novel drug targets.

PMID: 18559266 [PubMed - indexed for MEDLINE]

ecdysone chir-258 dovitinib

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]

chir-258 dovitinib dna-pk

A validated tumorgraft model reveals activity of dovitinib against renal cell carcinoma.

A validated tumorgraft model reveals activity of dovitinib against renal cell carcinoma.

Sci Transl Med. 2012 Jun 6;4(137):137ra75

Authors: Sivanand S, Pe�a-Llopis S, Zhao H, Kucejova B, Spence P, Pavia-Jimenez A, Yamasaki T, McBride DJ, Gillen J, Wolff NC, Morlock L, Lotan Y, Raj GV, Sagalowsky A, Margulis V, Cadeddu JA, Ross MT, Bentley DR, Kabbani W, Xie XJ, Kapur P, Williams NS, Brugarolas J

Abstract
Most anticancer drugs entering clinical trials fail to achieve approval from the U.S. Food and Drug Administration. Drug development is hampered by the lack of preclinical models with therapeutic predictive value. Herein, we report the development and validation of a tumorgraft model of renal cell carcinoma (RCC) and its application to the evaluation of an experimental drug. Tumor samples from 94 patients were implanted in the kidneys of mice without additives or disaggregation. Tumors from 35 of these patients formed tumorgrafts, and 16 stable lines were established. Samples from metastatic sites engrafted at higher frequency than those from primary tumors, and stable engraftment of primary tumors in mice correlated with decreased patient survival. Tumorgrafts retained the histology, gene expression, DNA copy number alterations, and more than 90% of the protein-coding gene mutations of the corresponding tumors. As determined by the induction of hypercalcemia in tumorgraft-bearing mice, tumorgrafts retained the ability to induce paraneoplastic syndromes. In studies simulating drug exposures in patients, RCC tumorgraft growth was inhibited by sunitinib and sirolimus (the active metabolite of temsirolimus in humans), but not by erlotinib, which was used as a control. Dovitinib, a drug in clinical development, showed greater activity than sunitinib and sirolimus. The routine incorporation of models recapitulating the molecular genetics and drug sensitivities of human tumors into preclinical programs has the potential to improve oncology drug development.

PMID: 22674553 [PubMed - indexed for MEDLINE]

coxinhibitors c-met inhibitors zm-447439

Molecular basis of drug resistance in aurora kinases.

Molecular basis of drug resistance in aurora kinases.

Chem Biol. 2008 Jun;15(6):552-62

Authors: Girdler F, Sessa F, Patercoli S, Villa F, Musacchio A, Taylor S

PMID: 18559266 [PubMed - indexed for MEDLINE]

dna-pk coxinhibitors c-met inhibitors

Steroid Signaling within Drosophila Ovarian Epithelial Cells Sex-Specifically Modulates Early Germ Cell Development and Meiotic Entry.

Steroid Signaling within Drosophila Ovarian Epithelial Cells Sex-Specifically Modulates Early Germ Cell Development and Meiotic Entry.

PLoS One. 2012;7(10):e46109

Authors: Morris LX, Spradling AC

Abstract
Drosophila adult females but not males contain high levels of the steroid hormone ecdysone, however, the roles played by steroid signaling during Drosophila gametogenesis remain poorly understood. Drosophila germ cells in both sexes initially follow a similar pathway. After germline stem cells are established, their daughters form interconnected cysts surrounded by somatic escort (female) or cyst (male) cells and enter meiosis. Subsequently, female cysts acquire a new covering of somatic cells to form follicles. Knocking down expression of the heterodimeric ecdysteroid receptor (EcR/Usp) or the E75 early response gene in escort cells disrupts 16-cell cyst production, meiotic entry and follicle formation. Escort cells lose their squamous morphology and unsheath germ cells. By contrast, disrupting ecdysone signaling in males does not perturb cyst development or ensheathment. Thus, sex-specific steroid signaling is essential for female germ cell development at the time male and female pathways diverge. Our results suggest that steroid signaling plays an important sex-specific role in early germ cell development in Drosophila, a strategy that may be conserved in mammals.

PMID: 23056242 [PubMed - in process]

c-met inhibitors zm-447439 rad001

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