5-alpha-reductase: 2012-10-07

2012年10月13日星期六

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]

ecdysone chir-258 dovitinib

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]

zm-447439 rad001 ecdysone

Length of mitotic arrest induced by microtubule-stabilizing drugs determines cell death after mitotic exit.

Length of mitotic arrest induced by microtubule-stabilizing drugs determines cell death after mitotic exit.

Mol Cancer Ther. 2009 Jun;8(6):1646-54

Authors: Bekier ME, Fischbach R, Lee J, Taylor WR

Abstract
Cell death induced by agents that disrupt microtubules can kill cells by inducing a prolonged mitotic block. This mitotic block is dependent on the spindle assembly checkpoint, a surveillance system that ensures the bipolar attachment of chromosomes to the mitotic spindle before the onset of anaphase. Under some conditions, the spindle assembly checkpoint can become weakened, allowing cells to exit mitosis despite the presence of chromosomes that are not properly attached to the mitotic spindle. Here, we use an Aurora kinase inhibitor to drive mitotic exit and test the effect of mitotic arrest length on death in the subsequent interphase. Cells that are blocked in mitosis for >15 h die shortly after exiting from mitosis, whereas cells that exit after being blocked for <15 h show variable fates, with some living for days after exiting mitosis. Cells blocked in mitosis by either Taxol or epothilone B are acutely sensitive to the death ligand tumor necrosis factor-related apoptosis-inducing ligand, suggesting that prolonged mitosis allows the gradual accumulation of internal death signals, rendering cells hypersensitive to additional prodeath cues. Death under these conditions is initiated while cyclin B1 is still present, indicating that cells are in mitosis. Our experiments suggest that there is a point of no return during prolonged mitotic block after which mitotic exit can no longer block death.

PMID: 19509263 [PubMed - indexed for MEDLINE]

c-met inhibitors zm-447439 rad001

Frequent overexpression of aurora B kinase, a novel drug target, in non-small cell lung carcinoma patients.

Frequent overexpression of aurora B kinase, a novel drug target, in non-small cell lung carcinoma patients.

Mol Cancer Ther. 2006 Nov;5(11):2905-13

Authors: Vischioni B, Oudejans JJ, Vos W, Rodriguez JA, Giaccone G

Abstract
The serine/threonine protein kinase aurora B, a key regulator of mitosis, is emerging as a novel drug target for cancer treatment. Aurora B overexpression has been previously documented by immunohistochemistry in several types of human tumors. We assessed aurora B expression in a series of 160 non-small cell lung cancer (NSCLC) samples (60% stage I, 21% stage II, 11% stage III, and 8% stage IV). In addition, we determined the expression of survivin and p16, two molecules also involved in cell cycle control. Aurora B was expressed selectively in tumor cells compared with normal epithelium. Aurora B expression was significantly correlated with expression of survivin in the nucleus (P < 0.0001), but not with expression of p16 (P = 0.134). High aurora B expression levels were significantly associated with older age (P = 0.012), male sex (P = 0.013), squamous cell carcinoma histology (P = 0.001), poor tumor differentiation grade (P = 0.007), and lymph node invasion (P = 0.037), in the subset of radically resected patients in our series. In addition, aurora B expression predicted shorter survival for the patients with adenocarcinoma histology, at both univariate (P = 0.020) and multivariate (P = 0.012) analysis. Survivin expression levels were neither associated with patient clinicopathologic characteristics nor with survival. However, expression of survivin in the nucleus was preferentially detected in stage I and II than in stage III and IV (P = 0.007) in the overall series of NSCLC samples. Taken together, our results suggest that aurora B may represent a valid target in NSCLC.

PMID: 17121938 [PubMed - indexed for MEDLINE]

ecdysone chir-258 dovitinib

Effectiveness of statins in chronic kidney disease.

Effectiveness of statins in chronic kidney disease.

QJM. 2012 Jul;105(7):641-8

Authors: Sheng X, Murphy MJ, Macdonald TM, Wei L

Abstract
BACKGROUND: Previous studies show that statins reduce total cholesterol (TC) concentration by both 21% in primary prevention (PP) and secondary prevention (SP) in clinical trials and by ?24% in the general population. There are few data about the efficacy of statins on TC concentration and cardiovascular (CV) outcome in patients with chronic kidney disease (CKD). We evaluated the reduction of TC concentration and subsequent risk of CV morbidity and mortality with statins in CKD patients.
METHODS: A population-based cohort study using a record-linkage database in Tayside, Scotland. A total of 2369 patients who had a primary diagnosis of CKD from Scottish Morbidity Record data or biochemistry database (serum creatinine of 220??mol/l or higher) and who had at least two separate TC measurements between 1993 and 2007 were studied. Patients were categorized into statin-exposed and statin-unexposed groups according to statin use status during the follow-up. They were also classified into PP (n?=?1325) and SP (n?=?1044) cohorts at the entry date. The main outcomes were TC concentration change from baseline, CV events [Antiplatelet Trialist's Collaboration (APTC)] and all-cause mortality during the follow-up. Cox regression models, in which statin use was a time-dependent variable, were employed to assess the risk of outcome and adjusted for other known confounders.
RESULTS: Statin-associated TC concentrations decreased by 0.59?mmol/l (12%) in PP cohort and 0.56?mmol/l (13%) in SP cohort from 4.77 and 4.48?mmol/l at baselines, respectively. Statin use was associated with a reduced risk of APTC events, CV mortality or all-cause mortality in PP {adjusted hazard ratio (HR), 0.65 [95% confidence interval (CI) 0.48-0.88]; 0.73 (95% CI 0.52-0.98); 0.59 (95% CI 0.48-0.73)} and SP [adjusted HR, 0.66 (95% CI 0.52-0.84); 0.60 (95% CI 0.47-0.77); 0.56 (95% CI 0.47-0.68)], respectively.
CONCLUSION: Statin use reduced TC concentrations by ?13% in patients with CKD. Statins were protective of APTC events, CV mortality and all-cause mortality in patients with or without established CV disease.

PMID: 22383690 [PubMed - indexed for MEDLINE]

c-met inhibitors zm-447439 rad001

2012年10月12日星期五

Aurora B confers cancer cell resistance to TRAIL-induced apoptosis via phosphorylation of survivin.

Aurora B confers cancer cell resistance to TRAIL-induced apoptosis via phosphorylation of survivin.

Carcinogenesis. 2012 Mar;33(3):492-500

Authors: Yoon MJ, Park SS, Kang YJ, Kim IY, Lee JA, Lee JS, Kim EG, Lee CW, Choi KS

Abstract
Tumor necrosis factor-related apoptosis-induced ligand (TRAIL) induces apoptosis selectively in cancer cells while sparing normal cells. However, many cancer cells are resistant to TRAIL-induced cell death. In this study, we examined whether Aurora B, which is frequently overexpressed in cancer cells, is associated with TRAIL resistance. The protein levels of Aurora B were higher in TRAIL-resistant cancer cell lines than in TRAIL-sensitive cancer cell lines. Exogenously expressed Aurora B attenuated TRAIL-induced apoptosis in the tested TRAIL-sensitive cancer cell lines, whereas the small interfering RNA-mediated suppression of Aurora B expression stimulated TRAIL-mediated apoptosis in the tested TRAIL-resistant cancer cell lines. Furthermore, combined treatment with TRAIL and ZM447439, a specific inhibitor of Aurora B, synergistically induced apoptosis in various TRAIL-resistant cancer cells, suggesting that this combined regimen may represent an attractive strategy for effectively treating TRAIL-resistant malignant cancers. Mechanistically, the inhibition of Aurora B activity in various cancer cells commonly downregulated survivin protein levels and potentiated the activation of caspase-3. In addition, Aurora B inhibition induced mitotic catastrophe, which also contributed to the sensitization of cells to TRAIL-mediated apoptosis. Interestingly, forced overexpression of Aurora B increased the protein levels of survivin, but not those of a non-phosphorylatable survivin mutant in which threonine 117 was replaced by alanine, indicating that phosphorylation of survivin is required for this effect. Furthermore, TRAIL-induced apoptosis in MDA-MB-435S cells was attenuated by wild-type survivin but not by the non-phosphorylatable survivin mutant. Collectively, our results demonstrate that Aurora B confers TRAIL resistance to cancer cells via phosphorylation of survivin.

PMID: 22159225 [PubMed - indexed for MEDLINE]

chir-258 dovitinib dna-pk

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]

zm-447439 rad001 ecdysone

Treatment of mild to moderate Graves' ophthalmopathy with sodium diclofenac: a pilot study.

Treatment of mild to moderate Graves' ophthalmopathy with sodium diclofenac: a pilot study.

Arq Bras Endocrinol Metabol. 2011 Dec;55(9):692-5

Authors: Bloise W, Mimura LY, Moura J, Nicolau W

Abstract
OBJECTIVE: To report the use of sodium diclofenac, an antagonist of PPAR-gamma and cyclooxigenase-2 (COX-2) inhibitor in the treatment of mild to moderate Graves' ophthalmopathy.
SUBJECTS AND METHODS: Thirteen patients with clinical activity score (CAS) 2 to 7 were treated during a period ranging from 3 to 12 months (mean 7.8 � 3.4) with oral sodium diclofenac, 50 mg every 12 hours.
RESULTS: Extra-ocular muscle restriction and CAS improved significantly, p = 0.003 and = 0.004, respectively. Ocular pain and diplopia disappeared, except for one patient who reported improvement of these symptoms. No recurrence was found after interruption of treatment.
CONCLUSIONS: Treatment of moderate Graves' ophthalmopathy with oral sodium diclofenac is a good, safe and less expensive therapeutic option. Like others new treatment trials, findings must be confirmed in a greater number of patients in a controlled study.

PMID: 22231971 [PubMed - indexed for MEDLINE]

dovitinib dna-pk coxinhibitors

Effectiveness of statins in chronic kidney disease.

Effectiveness of statins in chronic kidney disease.

QJM. 2012 Jul;105(7):641-8

Authors: Sheng X, Murphy MJ, Macdonald TM, Wei L

PMID: 22383690 [PubMed - indexed for MEDLINE]

dna-pk coxinhibitors c-met inhibitors

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]

dna-pk coxinhibitors c-met inhibitors

2012年10月11日星期四

Sulfonilamidothiopyrimidone and thiopyrimidone derivatives as selective COX-2 inhibitors: Synthesis, biological evaluation, and docking studies.

Sulfonilamidothiopyrimidone and thiopyrimidone derivatives as selective COX-2 inhibitors: Synthesis, biological evaluation, and docking studies.

Eur J Med Chem. 2012 Sep 10;57C:149-161

Authors: Basile L, Alvarez S, Blanco A, Santagati A, Granada G, Di Pietro P, Guccione S, Mu�oz-Fern�ndez MA

Abstract
Newly synthesized sulfonilamidothiopyrimidone derivatives and a subset of 14 sulfonilamidothiopyrimidones and thiopyrimidones selected by an MTT assays cell viability guided selection from an in house collection were evaluated to determine the inhibitory effect on the PGE(2) formation in human peripheral blood lymphocytes (PBLs) using commercial ELISA. The newly synthesized sulfonilamidothiopyrimidone derivatives showed interesting pharmacological activities. Preliminary in�vitro assays showed that compounds 2-5 are endowed with very high activity. Compound 2 was the most active as hCOX-2 inhibitor. The observed effects were not due to an inhibition of cell proliferation as proved by the BrdU assay. Western blot of COX-2 confirmed the inhibition on the PGE(2) secretion. Further evidence on the inhibitory potential and selectivity as COX-2 inhibitors of the selected compounds came from the in�vitro screening. In order to better rationalize the action and the binding mode of these compounds, docking studies were carried out. These studies were in agreement with the biological data. Compounds 2-5 were able to fit into the active site of COX-2 with highest scores and interaction energies. Furthermore, compound 2, which showed an inhibition of around 50% on PGE(2) production, was the best scored in all the docking calculations carried out.

PMID: 23047231 [PubMed - as supplied by publisher]

zm-447439 rad001 ecdysone

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]

ecdysone chir-258 dovitinib

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]

chir-258 dovitinib dna-pk

Targeting Protein for Xenopus kinesin like protein 2 (TPX2) regulates gamma-H2AX levels upon ionizing radiation.

Targeting Protein for Xenopus kinesin like protein 2 (TPX2) regulates gamma-H2AX levels upon ionizing radiation.

J Biol Chem. 2012 Oct 8;

Authors: Neumayer G, Helfricht A, Shim SY, Le HT, Lundin C, Belzil C, Chansard M, Yu Y, Lees-Miller SP, Gruss O, van Attikum H, Helleday T, Nguyen MD

Abstract
The microtubule-associated protein TPX2 plays a key role in spindle assembly and is required for mitosis in human cells. In interphase, TPX2 is actively imported into the nucleus to prevent its premature activity in microtubule organization. To date, no function has been assigned to nuclear TPX2. We now report that TPX2 plays a role in the cellular response to DNA double strand breaks induced by ionizing radiation. Loss of TPX2 leads to inordinately strong and transient accumulation of ionizing radiation-dependent Ser139-phosphorylated Histone 2AX (?-H2AX) at G0 and G1 phases of the cell cycle. This is accompanied by the formation of increased numbers of high intensity ?-H2AX ionizing radiation-induced foci. Conversely, cells overexpressing TPX2 have reduced levels of ?-H2AX after ionizing radiation. Consistent with a role for TPX2 in the DNA damage response, we found that the protein accumulates at DNA double strand breaks and associates with the Mediator of DNA damage Checkpoint 1 (MDC1) and the Ataxia Telangiectasia Mutated (ATM) kinase, both key regulators of ?-H2AX amplification. Pharmacologic inhibition or depletion of ATM or MDC1, but not of DNA-dependent protein kinase (DNA-PK), antagonizes the ?-H2AX phenotype caused by TPX2 depletion. Importantly, the regulation of ?-H2AX signals by TPX2 is not associated with apoptosis or the mitotic functions of TPX2. In sum, our study identifies a novel and the first nuclear function for TPX2 in the cellular responses to DNA damage.

PMID: 23045526 [PubMed - as supplied by publisher]

dovitinib dna-pk coxinhibitors

2012年10月10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]

c-met inhibitors zm-447439 rad001

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]

dovitinib dna-pk coxinhibitors

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]

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]

dna-pk coxinhibitors c-met inhibitors

2012年10月9日星期二

Simple synthesis of carbon-11-labeled chromen-4-one derivatives as new potential PET agents for imaging of DNA-dependent protein kinase (DNA-PK) in cancer.

Simple synthesis of carbon-11-labeled chromen-4-one derivatives as new potential PET agents for imaging of DNA-dependent protein kinase (DNA-PK) in cancer.

Appl Radiat Isot. 2012 Aug;70(8):1558-63

Authors: Gao M, Wang M, Miller KD, Zheng QH

Abstract
Carbon-11-labeled chromen-4-one derivatives were synthesized as new potential PET agents for imaging of DNA repair enzyme DNA-dependent protein kinase (DNA-PK) in cancer. The target tracers, X-[(11)C]methoxy-2-morpholino-4H-chromen-4-ones (X=8, 7, 6, 5; [(11)C]4a-d), were prepared from their corresponding precursors, X-hydroxy-2-morpholino-4H-chromen-4-ones (X=8, 7, 6, 5; 5a-d), with [(11)C]CH(3)OTf through O-[(11)C]methylation and isolated by a simplified solid-phase extraction (SPE) method using a C-18 Sep-Pak Plus cartridge. The radiochemical yields decay corrected to end of bombardment (EOB), from [(11)C]CO(2), were 40-60%. The specific activity at end of synthesis (EOS) was 185-370 GBq/?mol.

PMID: 22732390 [PubMed - in process]

dovitinib dna-pk coxinhibitors

Pyridofuran substituted pyrimidine derivatives as HCV replication (replicase) inhibitors.

Pyridofuran substituted pyrimidine derivatives as HCV replication (replicase) inhibitors.

Bioorg Med Chem Lett. 2012 Aug 1;22(15):5144-9

Authors: Bennett F, Kezar HS, Girijavallabhan V, Huang Y, Huelgas R, Rossman R, Shih NY, Piwinski JJ, MacCoss M, Kwong CD, Clark JL, Fowler AT, Geng F, Roychowdhury A, Reynolds RC, Maddry JA, Ananthan S, Secrist JA, Li C, Chase R, Curry S, Huang HC, Tong X, George Njoroge F, Arasappan A

Abstract
Introduction of nitrogen atom into the benzene ring of a previously identified HCV replication (replicase) benzofuran inhibitor 2, resulted in the discovery of the more potent pyridofuran analogue 5. Subsequent introduction of small alkyl and alkoxy ligands into the pyridine ring resulted in further improvements in replicon potency. Replacement of the 4-chloro moiety on the pyrimidine core with a methyl group, and concomitant monoalkylation of the C-2 amino moiety resulted in the identification of several inhibitors with desirable characteristics. Inhibitor 41, from the monosubstituted pyridofuran and inhibitor 50 from the disubstituted series displayed excellent potency, selectivity (GAPDH/MTS CC(50)) and PK parameters in all species studied, while the selectivity in the thymidine incorporation assay (DNA�CC(50)) was low.

PMID: 22814211 [PubMed - in process]

rad001 ecdysone chir-258

Downregulation of protein kinase CK2 induces autophagic cell death through modulation of the mTOR and MAPK signaling pathways in human glioblastoma cells.

Downregulation of protein kinase CK2 induces autophagic cell death through modulation of the mTOR and MAPK signaling pathways in human glioblastoma cells.

Int J Oncol. 2012 Sep 21;

Authors: Olsen BB, Svenstrup TH, Guerra B

Abstract
Glioblastoma multiforme is the most common primary brain tumor and one of the most aggressive types of cancer in adults. Survival signaling and apoptosis resistance are hallmarks of malignant glioma cells. However, recent studies have shown that other types of cell death such as autophagy can be induced in malignant glioma cells. This suggests that stimulation of this process may be explored in new therapeutic strategies against glioblastoma multiforme. Protein kinase CK2 is a highly conserved and constitutively active enzyme that promotes numerous cellular processes such as survival, proliferation and differentiation. CK2 has been found elevated in several malignancies including brain tumors, and to confer resistance against chemotherapeutic agents and apoptotic stimuli. Recently, we have shown that the siRNA-mediated downregulation of CK2 leads to cell death in DNA-PK-proficient human glioblastoma cells. We show, here, that lack of CK2 results in significant induction of autophagic cell death in two human glioblastoma cell lines, M059K and T98G, as indicated by the positive staining of cells with the acidotropic dye acridine orange, and the specific recruitment of microtubule-associated protein 1 light chain 3 (LC3) to autophagosome membranes. Induction of autophagy is accompanied by CK2-dependent decreased phosphorylation of p70 ribosomal S6 and AKT kinases and significantly reduced expression levels of Raptor. In contrast, phosphorylation and activity levels of ERK1/2 are enhanced suggesting an inhibition of the PI3K/AKT/mTORC1 and activation of the ERK1/2 pathways. Furthermore, siRNA-mediated silencing of CK2 results in increased mitochondrial superoxide production in both glioblastoma cell lines. However, mitochondrial reactive oxygen species release correlates with induction of autophagy only in T98G cells. Taken together, our findings identify CK2 as a novel component of the autophagic machinery and underline the potential of its downregulation to kill glioblastoma cells by overcoming the resistance to multiple anticancer agents.

PMID: 23007634 [PubMed - as supplied by publisher]

dovitinib dna-pk coxinhibitors

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]

rad001 ecdysone chir-258

Anti-Neuropilin-1 (MNRP1685A): Unexpected Pharmacokinetic Differences Across Species, from Preclinical Models to Humans.

Anti-Neuropilin-1 (MNRP1685A): Unexpected Pharmacokinetic Differences Across Species, from Preclinical Models to Humans.

Pharm Res. 2012 Sep;29(9):2512-21

Authors: Xin Y, Bai S, Damico-Beyer LA, Jin D, Liang WC, Wu Y, Theil FP, Joshi A, Lu Y, Lowe J, Maia M, Brachmann RK, Xiang H

Abstract
PURPOSE: To compare the pharmacokinetics (PK) of MNRP1685A, a human monoclonal antibody (mAb) against neuropilin-1 (NRP1), in mice, rats, monkeys, and cancer patients from a Phase I study to model with parallel linear and nonlinear clearances.
METHODS: Binding characteristics of MNRP1685A in different species were evaluated using surface plasmon resonance technology. PK profiles of MNRP1685A after single and/or multiple doses in different species were analyzed using population analysis. PK parameters were compared across species.
RESULTS: MNRP1685A binds to NRP1 in all four species tested. Consistent with the wide expression of NRP1, MNRP1685A demonstrated pronounced non-linear PK over a wide dose range. PK profiles are best described by a two-compartment model with parallel linear and nonlinear clearances. Model-derived PK parameters suggest similar in-vivo target expression levels and binding affinity to target across all species tested. However, compared to typical human/humanized mAbs, non-specific clearance of MNRP1685A was faster in mice, rats, and humans (60.3, 19.4, and 8.5�ml/day/kg), but not in monkeys (3.22�ml/day/kg).
CONCLUSIONS: Monkey PK properly predicted the target-mediated clearance of MNRP1685A but underestimated its non-specific clearance in humans. This unique PK property warrants further investigation of underlying mechanisms.

PMID: 22707361 [PubMed - in process]

dovitinib dna-pk coxinhibitors

2012年10月8日星期一

A Critical Role for p130Cas in the Progression of Pulmonary Hypertension in Humans and Rodents.

A Critical Role for p130Cas in the Progression of Pulmonary Hypertension in Humans and Rodents.

Am J Respir Crit Care Med. 2012 Jul 12;

Authors: Tu L, De Man FS, Girerd B, Huertas A, Chaumais MC, Lecerf F, Fran�ois C, Perros F, Dorfm�ller P, Fadel E, Montani D, Eddahibi S, Humbert M, Guignabert C

Abstract
RATIONALE: Pulmonary arterial hypertension (PAH) is a progressive and fatal disease characterized by pulmonary arterial muscularization due to excessive pulmonary vascular cell proliferation and migration, a phenotype dependent upon growth factors and activation of receptor tyrosine kinases (RTKs). p130Cas is an adaptor protein involved in several cellular signaling pathways that control cell migration, proliferation and survival. OBJECTIVES: We hypothesized that in experimental and human PAH p130Cas signaling is over-activated, thereby facilitating the intracellular transmission of signal induced by fibroblast growth factor (FGF)-2, epidermal growth factor (EGF), and platelet-derived growth factor (PDGF). MEASUREMENTS AND MAIN RESULTS: In PAH patients, levels of p130Cas protein and/or activity are higher in the serum, in walls of distal pulmonary arteries, in cultured smooth muscle (PA-SMCs) and pulmonary endothelial cells (P-ECs) than controls. These abnormalities in the p130Cas signaling were also found to be in the chronically hypoxic mice and monocrotaline-injected rats as models of human PAH. We next obtained evidence for convergence and amplification of the growth-stimulating effect of EGF, FGF2 and PDGF signaling pathways via p130Cas signaling pathway. Finally, we found that daily treatment with each of the EGF-R inhibitor gefitinib, the FGF-R inhibitor dovitinib and the PDGF-R inhibitor imatinib started 2 weeks after a subcutaneous monocrotaline injection substantially attenuate the abnormal increase in p130cas and ERK1/2 activation and regress established PH. CONCLUSIONS: Our findings demonstrate that p130Cas signaling plays a critical role in experimental and iPAH by modulating pulmonary vascular cell migration, proliferation and by acting as an amplifier of RTKs downstream signals.

PMID: 22798315 [PubMed - as supplied by publisher]

ecdysone chir-258 dovitinib

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

Novel N-Linked Aminopiperidine Inhibitors of Bacterial Topoisomerase Type II with Reduced pK(a): Antibacterial Agents with an Improved Safety Profile.

Novel N-Linked Aminopiperidine Inhibitors of Bacterial Topoisomerase Type II with Reduced pK(a): Antibacterial Agents with an Improved Safety Profile.

J Med Chem. 2012 Aug 9;55(15):6916-33

Authors: Reck F, Alm RA, Brassil P, Newman JV, Ciaccio P, McNulty J, Barthlow H, Goteti K, Breen J, Comita-Prevoir J, Cronin M, Ehmann DE, Geng B, Godfrey AA, Fisher SL

Abstract
Novel non-fluoroquinolone inhibitors of bacterial type II topoisomerases (DNA gyrase and topoisomerase IV) are of interest for the development of new antibacterial agents that are not impacted by target-mediated cross-resistance with fluoroquinolones. N-Linked amino piperidines, such as 7a, generally show potent antibacterial activity, including against quinolone-resistant isolates, but suffer from hERG inhibition (IC(50) = 44 ?M for 7a) and QT prolongation in vivo. We now disclose the finding that new analogues of 7a with reduced pK(a) due to substitution with an electron-withdrawing substituent in the piperidine moiety, such as R,S-7c, retained the Gram-positive activity of 7a but showed significantly less hERG inhibition (IC(50) = 233 ?M for R,S-7c). This compound exhibited moderate clearance in dog, promising efficacy against a MRSA strain in a mouse infection model, and an improved in vivo QT profile as measured in a guinea pig in vivo model. As a result of its promising activity, R,S-7c was advanced into phase I clinical studies.

PMID: 22779424 [PubMed - in process]

rad001 ecdysone chir-258

Emtricitabine/tenofovir in the treatment of HIV infection: current PK/PD evaluation.

Emtricitabine/tenofovir in the treatment of HIV infection: current PK/PD evaluation.

Expert Opin Drug Metab Toxicol. 2012 Oct;8(10):1305-14

Authors: Uglietti A, Zanaboni D, Gnarini M, Maserati R

Abstract
Introduction: Emtricitabine/tenofovir disoproxil fumarate fixed-dose combination (FTC/TDF FDC) is the co-formulation of a nucleoside and a nucleotide, respectively. After oral administration, both drugs exhibit plasma and intracellular half-lives suitable for once-daily dosing. Within the host cells, active metabolites FTC-TP and TFV-DP act as chain terminators to the newly synthesized proviral DNA, showing synergy at enzymatic level (viral reverse transcriptase). When given in HAART combinations, FTC/TDF FDC has a remarkable effectiveness in controlling HIV replication and securing a significant CD4(+) cell recovery. If patients treated with FTC/TDF FDC fail, a lower incidence of TDF-associated K65R resistance mutation seems to develop. Furthermore, cytidine analog-associated M184V is less likely to appear with FTC than with lamivudine when both are given with TDF. FTC and TFV are not metabolized by CYP450 enzymes and are eliminated by the renal route. TFV may accumulate in tubular cells and cause a decrease in GFR and a loss of phosphates. As a onsequence, patients treated with FTC/TDF FCD may experience varied degrees of renal impairment and osteopenia/osteoporosis. Areas covered: This paper has focused on the PK/PD features of FTC and TDF, when given as single agent or when administered as FDC. The interpretation of efficacy/toxicity was guided by PK/PD features. The review of the available literature included also conference presentations and recent guidelines (as of May 2012). Expert opinion: FTC/TDF FDC is a potent and reliable component of most HAART combinations due to its maintained activity across time, as demonstrated in many trials and studies. Toxicity issues (kidney, bone) are still to be entirely elucidated and the drug-induced component well separated from patient- and HIV-related ones. However, the clinical gain associated with the use of FTC/TDF FDC is fully acknowledged by its leading position in most current treatment guidelines.

PMID: 22943210 [PubMed - in process]

rad001 ecdysone chir-258

Emtricitabine/tenofovir in the treatment of HIV infection: current PK/PD evaluation.

Emtricitabine/tenofovir in the treatment of HIV infection: current PK/PD evaluation.

Expert Opin Drug Metab Toxicol. 2012 Oct;8(10):1305-14

Authors: Uglietti A, Zanaboni D, Gnarini M, Maserati R

PMID: 22943210 [PubMed - in process]

zm-447439 rad001 ecdysone

2012年10月7日星期日

Erythrocytic Pyruvate Kinase Mutations Causing Hemolytic Anemia, Osteosclerosis, and Secondary Hemochromatosis in Dogs.

Erythrocytic Pyruvate Kinase Mutations Causing Hemolytic Anemia, Osteosclerosis, and Secondary Hemochromatosis in Dogs.

J Vet Intern Med. 2012 Jul 13;

Authors: Inal Gultekin G, Raj K, Foureman P, Lehman S, Manhart K, Abdulmalik O, Giger U

Abstract
BACKGROUND: Erythrocytic pyruvate kinase (PK) deficiency, first documented in Basenjis, is the most common inherited erythroenzymopathy in dogs. OBJECTIVES: To report 3 new breed-specific PK-LR gene mutations and a retrospective survey of PK mutations in a small and selected group of Beagles and West Highland White Terriers (WHWT). ANIMALS: Labrador Retrievers (2 siblings, 5 unrelated), Pugs (2 siblings, 1 unrelated), Beagles (39 anemic, 29 other), WHWTs (22 anemic, 226 nonanemic), Cairn Terrier (n�=�1). METHODS: Exons of the PK-LR gene were sequenced from genomic DNA of young dogs (<2�years) with persistent highly regenerative hemolytic anemia. RESULTS: A nonsense mutation (c.799C>T) resulting in a premature stop codon was identified in anemic Labrador Retriever siblings that had osteosclerosis, high serum ferritin concentrations, and severe hepatic secondary hemochromatosis. Anemic Pug and Beagle revealed 2 different missense mutations (c.848T>C, c.994G>A, respectively) resulting in intolerable amino acid changes to protein structure and enzyme function. Breed-specific mutation tests were developed. Among the biased group of 248 WHWTs, 9% and 35% were homozygous (affected) and heterozygous, respectively, for the previously described mutation (mutant allele frequency 0.26). A PK-deficient Cairn Terrier had the same insertion mutation as the affected WHWTs. Of the selected group of 68 Beagles, 35% were PK-deficient and 3% were carriers (0.37). CONCLUSIONS AND CLINICAL IMPORTANCE: Erythrocytic PK deficiency is caused by different mutations in different dog breeds and causes chronic severe hemolytic anemia, hemosiderosis, and secondary hemochromatosis because of chronic hemolysis and, an as yet unexplained osteosclerosis. The newly developed breed-specific mutation assays simplify the diagnosis of PK deficiency.

PMID: 22805166 [PubMed - as supplied by publisher]

coxinhibitors c-met inhibitors zm-447439

Analysis and results of Ku and XRCC4 expression in hypopharyngeal cancer tissues treated with chemoradiotherapy.

Analysis and results of Ku and XRCC4 expression in hypopharyngeal cancer tissues treated with chemoradiotherapy.

Oncol Lett. 2012 Jul;4(1):151-155

Authors: Hayashi J, Sakata KI, Someya M, Matsumoto Y, Satoh M, Nakata K, Hori M, Takagi M, Kondoh A, Himi T, Hareyama M

Abstract
DNA double-strand break (DSB) is one of the most serious forms of damage induced by ionizing irradiation. Non-homologous end-joining (NHEJ) is a key mechanism of DNA DSB repair. The immunohistochemical analysis of proteins involved in NHEJ may have potential as a predictive assay for tumor radiosensitivity. We examined the correlation between the expression of proteins involved in DNA DSB in biopsy specimens and the results of chemoradiotherapy in hypopharyngeal cancers. Fifty-seven patients with previously untreated squamous cell carcinoma of the hypopharynx were treated between March 2002 and December 2009. Most patients (75%) had stage III or IV disease. The chemotherapy consisted of cisplatin plus 5FU or S-1. A tumor dose of 50 Gy was usually administered to the primary tumor and regional lymph nodes. Doses of 10-20 Gy were usually added to the primary tumor with reduced fields after 50 Gy. The 5-year disease-free survival rate was 100% for patients in stage I, 90% in stage II, 64% in stage III and 50% in stage IV. In stages I-III, patients with a lower expression of Ku70 or XRCC4 tended to have better locoregional control. These results indicated that a lower expression of Ku70 or XRCC4 may be correlated with higher radiosensitivity. Two patients had distant metastasis alone, of which one had 0% expression of Ku70 and the other had 0% expression of Ku86. The absence of Ku70 or Ku86 expression indicates low DNA-PK activity. Low DNA-PK activity due to a low expression of Ku may result in the genetic alteration of cancer cells, leading to a higher tendency of distant metastasis. This finding suggests that proteins involved in NHEJ may have an impact on the treatment results of chemoradiotherapy in hypopharyngeal cancer.

PMID: 22807979 [PubMed - as supplied by publisher]

coxinhibitors c-met inhibitors zm-447439

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]

coxinhibitors c-met inhibitors zm-447439

Phase I/II and pharmacodynamic study of dovitinib (TKI258), an inhibitor of fibroblast growth factor receptors and VEGF receptors, in patients with advanced melanoma.

Phase I/II and pharmacodynamic study of dovitinib (TKI258), an inhibitor of fibroblast growth factor receptors and VEGF receptors, in patients with advanced melanoma.

Clin Cancer Res. 2011 Dec 1;17(23):7451-61

Authors: Kim KB, Chesney J, Robinson D, Gardner H, Shi MM, Kirkwood JM

Abstract
PURPOSE: Dovitinib (TKI258) is an orally available inhibitor of fibroblast growth factor (FGF), VEGF, and platelet-derived growth factor receptors. This phase I/II dose-escalation study was conducted to evaluate the safety, pharmacodynamics, and preliminary efficacy of dovitinib in the treatment of advanced melanoma.
EXPERIMENTAL DESIGN: Patients with advanced melanoma resistant or refractory to standard therapies or for whom no standard therapy was available were enrolled. Dovitinib was administered at doses ranging from 200 to 500 mg/d.
RESULTS: Forty-seven patients were enrolled. The most frequently reported adverse events were fatigue (77%; grade ?3, 28%), diarrhea (77%; grade ?3, 11%), and nausea (77%; grade ?3, 9%). Six dose-limiting toxicities were observed in the 400-mg and 500-mg dose cohorts, which consisted of grade 3 nausea, fatigue, and diarrhea and grade 4 fatigue events. The maximum tolerated dose was 400 mg/d. The best tumor response was stable disease, which was observed in 12 patients. Increases in plasma FGF23, VEGF, and placental growth factor and decreases in soluble VEGF receptor 2 were noted during the first cycle of treatment, consistent with FGF receptor (FGFR) and VEGF receptor (VEGFR) inhibition. Dynamic contrast-enhanced MRI analysis showed a dose-dependent decrease in tumor blood flow and vascular permeability with dovitinib therapy. A decrease in FGFR phosphorylation was observed in paired tumor biopsy samples from a patient treated with dovitinib at a dose of 400 mg/d.
CONCLUSIONS: At a dose of 400 mg/d, dovitinib showed an acceptable safety profile and limited clinical benefit and inhibited FGFR and VEGFR.

PMID: 21976540 [PubMed - indexed for MEDLINE]

ecdysone chir-258 dovitinib

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]

chir-258 dovitinib dna-pk

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