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Sample records for rho kinase inhibitor

  1. Partial contribution of Rho-kinase inhibition to the bioactivity of Ganoderma lingzhi and its isolated compounds: insights on discovery of natural Rho-kinase inhibitors.

    Science.gov (United States)

    Amen, Yhiya; Zhu, Qinchang; Tran, Hai-Bang; Afifi, Mohamed S; Halim, Ahmed F; Ashour, Ahmed; Shimizu, Kuniyoshi

    2017-04-01

    Recent studies identified Rho-kinase enzymes (ROCK-I and ROCK-II) as important targets that are involved in a variety of diseases. Synthetic Rho-kinase inhibitors have emerged as potential therapeutic agents to treat disorders such as hypertension, stroke, cancer, diabetes, glaucoma, etc. Our study is the first to screen the total ethanol extract of the medicinal mushroom Ganoderma lingzhi with thirty-five compounds for Rho-kinase inhibitory activity. Moreover, a molecular binding experiment was designed to investigate the binding affinity of the compounds at the active sites of Rho-kinase enzymes. The structure-activity relationship analysis was investigated. Our results suggest that the traditional uses of G. lingzhi might be in part due to the ROCK-I and ROCK-II inhibitory potential of this mushroom. Structure-activity relationship studies revealed some interesting features of the lanostane triterpenes that potentiate their Rho-kinase inhibition. These findings would be helpful for further studies on the design of Rho-kinase inhibitors from natural sources and open the door for contributions from other researchers for optimizing the development of natural Rho-kinase inhibitors.

  2. Comparisons of actin filament disruptors and Rho kinase inhibitors as potential antiglaucoma medications

    OpenAIRE

    Tian, Baohe; Kaufman, Paul L

    2012-01-01

    Dynamics of the actin cytoskeleton in the trabecular meshwork play a crucial role in the regulation of trabecular outflow resistance. The actin filament disruptors and Rho kinase inhibitors affect the dynamics of the actomyosin system by either disrupting the actin filaments or inhibiting the Rho kinase-activated cellular contractility. Both approaches induce similar morphological changes and resistance decreases in the trabecular outflow pathway, and thus both have potential as antiglaucoma ...

  3. Reduction of Fibrogenesis by Selective Delivery of a Rho Kinase Inhibitor to Hepatic Stellate Cells in Mice

    NARCIS (Netherlands)

    van Beuge, M. M.; Prakash, J.; Lacombe, M.; Gosens, R.; Post, E.; Reker-Smit, C.; Beljaars, L.; Poelstra, K.

    One of the pathways activated during liver fibrosis is the Rho kinase pathway, which regulates activation, migration, and contraction of hepatic stellate cells (HSC). Inhibition of this kinase by the Rho kinase inhibitor Y27632 [(+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide

  4. Rho-associated kinase inhibitors: a novel glaucoma therapy.

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    Inoue, Toshihiro; Tanihara, Hidenobu

    2013-11-01

    The rho-associated kinase (ROCK) signaling pathway is activated via secreted bioactive molecules or via integrin activation after extracellular matrix binding. These lead to polymerization of actin stress fibers and formation of focal adhesions. Accumulating evidence suggests that actin cytoskeleton-modulating signals are involved in aqueous outflow regulation. Aqueous humor contains various biologically active factors, some of which are elevated in glaucomatous eyes. These factors affect aqueous outflow, in part, through ROCK signaling modulation. Various drugs acting on the cytoskeleton have also been shown to increase aqueous outflow by acting directly on outflow tissue. In vivo animal studies have shown that the trabecular meshwork (TM) actin cytoskeleton in glaucomatous eyes is more disorganized and more randomly oriented than in non-glaucomatous control eyes. In a previous study, we introduced ROCK inhibitors as a potential glaucoma therapy by showing that a selective ROCK inhibitor significantly lowered rabbit IOP. Rho-associated kinase inhibitors directly affect the TM and Schlemm's canal (SC), differing from the target sight of other glaucoma drugs. The TM is affected earlier and more strongly than ciliary muscle cells by ROCK inhibitors, largely because of pharmacological affinity differences stemming from regulatory mechanisms. Additionally, ROCK inhibitors disrupt tight junctions, result in F-actin depolymerization, and modulate intracellular calcium level, effectively increasing SC-cell monolayer permeability. Perfusion of an enucleated eye with a ROCK inhibitor resulted in wider empty spaces in the juxtacanalicular (JCT) area and more giant vacuoles in the endothelial cells of SC, while the endothelial lining of SC was intact. Interestingly, ROCK inhibitors also increase retinal blood flow by relaxing vascular smooth muscle cells, directly protecting neurons against various stresses, while promoting wound healing. These additional effects may help

  5. Discovery of aminofurazan-azabenzimidazoles as inhibitors of Rho-kinase with high kinase selectivity and antihypertensive activity.

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    Stavenger, Robert A; Cui, Haifeng; Dowdell, Sarah E; Franz, Robert G; Gaitanopoulos, Dimitri E; Goodman, Krista B; Hilfiker, Mark A; Ivy, Robert L; Leber, Jack D; Marino, Joseph P; Oh, Hye-Ja; Viet, Andrew Q; Xu, Weiwei; Ye, Guosen; Zhang, Daohua; Zhao, Yongdong; Jolivette, Larry J; Head, Martha S; Semus, Simon F; Elkins, Patricia A; Kirkpatrick, Robert B; Dul, Edward; Khandekar, Sanjay S; Yi, Tracey; Jung, David K; Wright, Lois L; Smith, Gary K; Behm, David J; Doe, Christopher P; Bentley, Ross; Chen, Zunxuan X; Hu, Erding; Lee, Dennis

    2007-01-11

    The discovery, proposed binding mode, and optimization of a novel class of Rho-kinase inhibitors are presented. Appropriate substitution on the 6-position of the azabenzimidazole core provided subnanomolar enzyme potency in vitro while dramatically improving selectivity over a panel of other kinases. Pharmacokinetic data was obtained for the most potent and selective examples and one (6n) has been shown to lower blood pressure in a rat model of hypertension.

  6. Stepwise high-throughput virtual screening of Rho kinase inhibitors from natural product library and potential therapeutics for pulmonary hypertension.

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    Su, Hao; Yan, Ji; Xu, Jian; Fan, Xi-Zhen; Sun, Xian-Lin; Chen, Kang-Yu

    2015-08-01

    Pulmonary hypertension (PH) is a devastating disease characterized by progressive elevation of pulmonary arterial pressure and vascular resistance due to pulmonary vasoconstriction and vessel remodeling. The activation of RhoA/Rho-kinase (ROCK) pathway plays a central role in the pathologic progression of PH and thus the Rho kinase, an essential effector of the ROCK pathway, is considered as a potential therapeutic target to attenuate PH. In the current study, a synthetic pipeline is used to discover new potent Rho inhibitors from various natural products. In the pipeline, the stepwise high-throughput virtual screening, quantitative structure-activity relationship (QSAR)-based rescoring, and kinase assay were integrated. The screening was performed against a structurally diverse, drug-like natural product library, from which six identified compounds were tested to determine their inhibitory potencies agonist Rho by using a standard kinase assay protocol. With this scheme, we successfully identified two potent Rho inhibitors, namely phloretin and baicalein, with activity values of IC50 = 0.22 and 0.95 μM, respectively. Structural examination suggested that complicated networks of non-bonded interactions such as hydrogen bonding, hydrophobic forces, and van der Waals contacts across the complex interfaces of Rho kinase are formed with the screened compounds.

  7. RhoA/Rho Kinase Mediates Neuronal Death Through Regulating cPLA2 Activation.

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    Wu, Xiangbing; Walker, Chandler L; Lu, Qingbo; Wu, Wei; Eddelman, Daniel B; Parish, Jonathan M; Xu, Xiao-Ming

    2017-11-01

    Activation of RhoA/Rho kinase leads to growth cone collapse and neurite retraction. Although RhoA/Rho kinase inhibition has been shown to improve axon regeneration, remyelination and functional recovery, its role in neuronal cell death remains unclear. To determine whether RhoA/Rho kinase played a role in neuronal death after injury, we investigated the relationship between RhoA/Rho kinase and cytosolic phospholipase A 2 (cPLA 2 ), a lipase that mediates inflammation and cell death, using an in vitro neuronal death model and an in vivo contusive spinal cord injury model performed at the 10th thoracic (T10) vertebral level. We found that co-administration of TNF-α and glutamate induced spinal neuron death, and activation of RhoA, Rho kinase and cPLA 2 . Inhibition of RhoA, Rho kinase and cPLA 2 significantly reduced TNF-α/glutamate-induced cell death by 33, 52 and 43 %, respectively (p < 0.001). Inhibition of RhoA and Rho kinase also significantly downregulated cPLA 2 activation by 66 and 60 %, respectively (p < 0.01). Furthermore, inhibition of RhoA and Rho kinase reduced the release of arachidonic acid, a downstream substrate of cPLA 2 . The immunofluorescence staining showed that ROCK 1 or ROCK 2 , two isoforms of Rho kinase, was co-localized with cPLA 2 in neuronal cytoplasm. Interestingly, co-immunoprecipitation (Co-IP) assay showed that ROCK 1 or ROCK 2 bonded directly with cPLA 2 and phospho-cPLA 2 . When the Rho kinase inhibitor Y27632 was applied in mice with T10 contusion injury, it significantly decreased cPLA 2 activation and expression and reduced injury-induced apoptosis at and close to the lesion site. Taken together, our results reveal a novel mechanism of RhoA/Rho kinase-mediated neuronal death through regulating cPLA 2 activation.

  8. Development of dihydropyridone indazole amides as selective Rho-kinase inhibitors.

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    Goodman, Krista B; Cui, Haifeng; Dowdell, Sarah E; Gaitanopoulos, Dimitri E; Ivy, Robert L; Sehon, Clark A; Stavenger, Robert A; Wang, Gren Z; Viet, Andrew Q; Xu, Weiwei; Ye, Guosen; Semus, Simon F; Evans, Christopher; Fries, Harvey E; Jolivette, Larry J; Kirkpatrick, Robert B; Dul, Edward; Khandekar, Sanjay S; Yi, Tracey; Jung, David K; Wright, Lois L; Smith, Gary K; Behm, David J; Bentley, Ross; Doe, Christopher P; Hu, Erding; Lee, Dennis

    2007-01-11

    Rho kinase (ROCK1) mediates vascular smooth muscle contraction and is a potential target for the treatment of hypertension and related disorders. Indazole amide 3 was identified as a potent and selective ROCK1 inhibitor but possessed poor oral bioavailability. Optimization of this lead resulted in the discovery of a series of dihydropyridones, exemplified by 13, with improved pharmacokinetic parameters relative to the initial lead. Indazole substitution played a critical role in decreasing clearance and improving oral bioavailability.

  9. Effects of chronic Δ9-tetrahydrocannabinol treatment on Rho/Rho-kinase signalization pathway in mouse brain

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    Halil Mahir Kaplan

    2017-11-01

    Full Text Available Δ9-Tetrahydrocannabinol (Δ9-THC shows its effects by activating cannabinoid receptors which are on some tissues and neurons. Cannabinoid systems have role on cell proliferation and development of neurons. Furthermore, it is interesting that cannabinoid system and rho/rho-kinase signalization pathway, which have important role on cell development and proliferation, may have role on neuron proliferation and development together. Thus, a study is planned to investigate rhoA and rho-kinase enzyme expressions and their activities in the brain of chronic Δ9-THC treated mice. One group of mice are treated with Δ9-THC once to see effects of acute treatment. Another group of mice are treated with Δ9-THC three times per day for one month. After this period, rhoA and rho-kinase enzyme expressions and their activities in mice brains are analyzed by ELISA method. Chronic administration of Δ9-THC decreased the expression of rhoA while acute treatment has no meaningful effect on it. Administration of Δ9-THC did not affect expression of rho-kinase on both chronic and acute treatment. Administration of Δ9-THC increased rho-kinase activity on both chronic and acute treatment, however, chronic treatment decreased its activity with respect to acute treatment. This study showed that chronic Δ9-THC treatment down-regulated rhoA expression and did not change the expression level of rho-kinase which is downstream effector of rhoA. However, it elevated the rho-kinase activity. Δ9-THC induced down-regulation of rhoA may cause elevation of cypin expression and may have benefit on cypin related diseases. Furthermore, use of rho-kinase inhibitors and Δ9-THC together can be useful on rho-kinase related diseases.

  10. RhoA/Rho-Kinase in the Cardiovascular System.

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    Shimokawa, Hiroaki; Sunamura, Shinichiro; Satoh, Kimio

    2016-01-22

    Twenty years ago, Rho-kinase was identified as an important downstream effector of the small GTP-binding protein, RhoA. Thereafter, a series of studies demonstrated the important roles of Rho-kinase in the cardiovascular system. The RhoA/Rho-kinase pathway is now widely known to play important roles in many cellular functions, including contraction, motility, proliferation, and apoptosis, and its excessive activity induces oxidative stress and promotes the development of cardiovascular diseases. Furthermore, the important role of Rho-kinase has been demonstrated in the pathogenesis of vasospasm, arteriosclerosis, ischemia/reperfusion injury, hypertension, pulmonary hypertension, and heart failure. Cyclophilin A is secreted by vascular smooth muscle cells and inflammatory cells and activated platelets in a Rho-kinase-dependent manner, playing important roles in a wide range of cardiovascular diseases. Thus, the RhoA/Rho-kinase pathway plays crucial roles under both physiological and pathological conditions and is an important therapeutic target in cardiovascular medicine. Recently, functional differences between ROCK1 and ROCK2 have been reported in vitro. ROCK1 is specifically cleaved by caspase-3, whereas granzyme B cleaves ROCK2. However, limited information is available on the functional differences and interactions between ROCK1 and ROCK2 in the cardiovascular system in vivo. Herein, we will review the recent advances about the importance of RhoA/Rho-kinase in the cardiovascular system. © 2016 American Heart Association, Inc.

  11. RhoA–Rho kinase and Platelet Activating Factor Stimulation of Ovine Fetal Pulmonary Vascular Smooth Muscle Cell Proliferation

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    Renteria, Lissette S.; Austin, Monique; Lazaro, Mariecon; Andrews, Mari Ashley; Lustina, Jennessee; Raj, J. Usha; Ibe, Basil O.

    2013-01-01

    Objectives Platelet Activating Factor (PAF) is produced by pulmonary vascular smooth muscle Cells (PVSMC). We studied effect of Rho kinase on PAF stimulation of PVSMC proliferation in an attempt to understand a role for RhoA/Rho kinase on PAF-induced ovine fetal pulmonary vascular remodeling. Our hypothesis is that PAF acts through Rho kinase, as one of its downstream signaling, to induce arterial (SMC-PA) and venous (SMC-PV) growth in the hypoxic lung environment of the fetus in utero. Materials and methods Rho kinase and MAPK effects on PAF receptor (PAFR)-mediated cell growth and PAFR expression were studied by DNA synthesis, Western and immunocytochemistry. Effects of constructs T19N and G14V on PAF-induced cell proliferation was also studied. Results Hypoxia increased PVSMC proliferation and the Rho kinase inhibitors, Y-27632 and Fasudil (HA-1077) as well as MAPK inhibitors PD 98059 and SB 203580 attenuated PAF stimulation of cell proliferation. RhoA T19N and G14V stimulated cell proliferation, but co-incubation with PAF did not affect proliferative effects of the constructs. PAFR protein expression was significantly down-regulated in both cell types by both Y-27632 and HA-1077 with comparable profiles. Also cells treated with Y-27632 showed less PAF receptor fluorescence with significant disruption of the cell morphology. Conclusions Our results show that Rho kinase nonspecifically modulates PAFR-mediated responses via a translational modification of PAFR protein and suggest that, in vivo, activation of Rho kinase by PAF may be one other pathway to sustain PAFR-mediated PVSMC growth. PMID:24033386

  12. RhoA-Rho kinase and platelet-activating factor stimulation of ovine foetal pulmonary vascular smooth muscle cell proliferation.

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    Renteria, L S; Austin, M; Lazaro, M; Andrews, M A; Lustina, J; Raj, J U; Ibe, B O

    2013-10-01

    Platelet-activating factor (PAF) is produced by pulmonary vascular smooth muscle cells (PVSMC). We studied effects of Rho kinase on PAF stimulation of PVSMC proliferation in an attempt to understand the role of RhoA/Rho kinase on PAF-induced ovine foetal pulmonary vascular remodelling. Our hypothesis is that PAF acts through Rho kinase, as one of its downstream signals, to induce arterial (SMC-PA) and venous (SMC-PV) cell proliferation in the hypoxic lung environment of the foetus, in utero. Rho kinase and MAPK effects on PAF receptor (PAFR)-mediated cell population expansion, and PAFR expression, were studied by DNA synthesis, western blot analysis and immunocytochemistry. Effects of constructs T19N and G14V on PAF-induced cell proliferation were also investigated. Hypoxia increased PVSMC proliferation and Rho kinase inhibitors, Y-27632 and Fasudil (HA-1077) as well as MAPK inhibitors PD 98059 and SB 203580 attenuated PAF stimulation of cell proliferation. RhoA T19N and G14V stimulated cell proliferation, but co-incubation with PAF did not affect proliferative effects of the constructs. PAFR protein expression was significantly downregulated in both cell types by both Y-27632 and HA-1077, with comparable profiles. Also, cells treated with Y-27632 had less PAF receptor fluorescence with significant disruption of cell morphology. Our results show that Rho kinase non-specifically modulated PAFR-mediated responses by a translational modification of PAFR protein, and suggest that, in vivo, activation of Rho kinase by PAF may be a further pathway to sustain PAFR-mediated PVSMC proliferation. © 2013 John Wiley & Sons Ltd.

  13. Differential effects of Rho-kinase inhibitor and angiotensin II type-1 receptor antagonist on the vascular function in hypertensive rats induced by chronic l-NAME treatment

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    Bainian Chen

    2012-10-01

    Full Text Available Little attention has been paid to the effect of Rho-kinase inhibitor on the vascular dysfunction of nitric oxide-deficient hypertension. We aimed to investigate whether the Rho-kinase inhibitor fasudil showed beneficial effect on the vascular dysfunction of the NG-nitro-l-arginine methyl ester (l-NAME treated rat, as well as to compare the differential effects of fasudil and angiotensin II receptor antagonist valsartan on vascular function. In the present study, both valsartan and fasudil exerted antihypertensive action on the l-NAME-treated rats, while only valsartan attenuated the cardiac hypertrophy. Treatment with valsartan showed improvement on vascular reactivity to norepinephrine, KCl and CaCl2, whereas fasudil therapy showed little effect on vasoconstriction. Endothelium-dependent vasodilation to acetylcholine was reduced in the NO-deficient group but was normalized by the fasudil therapy. The increased expression of RhoA and Rho-kinase (ROCK in the vasculature was corrected well to normal level by either valsartan or fasudil administration, which seemed to be at least partially responsible for the beneficial effect of the drug infusion. These findings suggest that the angiotensin II receptor antagonist interferes more with the contractile response than Rho-kinase inhibitor, whereas inhibition of Rho-kinase activity exhibits a better improvement on vasorelaxation than blockade of angiotensin II receptor.

  14. Membrane depolarization-induced RhoA/Rho-associated kinase activation and sustained contraction of rat caudal arterial smooth muscle involves genistein-sensitive tyrosine phosphorylation

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    Mita, Mitsuo; Tanaka, Hitoshi; Yanagihara, Hayato; Nakagawa, Jun-ichi; Hishinuma, Shigeru; Sutherland, Cindy; Walsh, Michael P.; Shoji, Masaru

    2013-01-01

    Rho-associated kinase (ROK) activation plays an important role in K+-induced contraction of rat caudal arterial smooth muscle (Mita et al., Biochem J. 2002; 364: 431–40). The present study investigated a potential role for tyrosine kinase activity in K+-induced RhoA activation and contraction. The non-selective tyrosine kinase inhibitor genistein, but not the src family tyrosine kinase inhibitor PP2, inhibited K+-induced sustained contraction (IC50 = 11.3 ± 2.4 µM). Genistein (10 µM) inhibited the K+-induced increase in myosin light chain (LC20) phosphorylation without affecting the Ca2+ transient. The tyrosine phosphatase inhibitor vanadate induced contraction that was reversed by genistein (IC50 = 6.5 ± 2.3 µM) and the ROK inhibitor Y-27632 (IC50 = 0.27 ± 0.04 µM). Vanadate also increased LC20 phosphorylation in a genistein- and Y-27632-dependent manner. K+ stimulation induced translocation of RhoA to the membrane, which was inhibited by genistein. Phosphorylation of MYPT1 (myosin-targeting subunit of myosin light chain phosphatase) was significantly increased at Thr855 and Thr697 by K+ stimulation in a genistein- and Y-27632-sensitive manner. Finally, K+ stimulation induced genistein-sensitive tyrosine phosphorylation of proteins of ∼55, 70 and 113 kDa. We conclude that a genistein-sensitive tyrosine kinase, activated by the membrane depolarization-induced increase in [Ca2+]i, is involved in the RhoA/ROK activation and sustained contraction induced by K+. Ca2+ sensitization, myosin light chain phosphatase, RhoA, Rho-associated kinase, tyrosine kinase PMID:24133693

  15. Rho-Kinase Inhibition Ameliorates Dasatinib-Induced Endothelial Dysfunction and Pulmonary Hypertension

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    Csilla Fazakas

    2018-05-01

    Full Text Available The multi-kinase inhibitor dasatinib is used for treatment of imatinib-resistant chronic myeloid leukemia, but is prone to induce microvascular dysfunction. In lung this can manifest as capillary leakage with pleural effusion, pulmonary edema or even pulmonary arterial hypertension. To understand how dasatinib causes endothelial dysfunction we examined the effects of clinically relevant concentrations of dasatinib on both human pulmonary arterial macro- and microvascular endothelial cells (ECs. The effects of dasatinib was compared to imatinib and nilotinib, two other clinically used BCR/Abl kinase inhibitors that do not inhibit Src. Real three-dimensional morphology and high resolution stiffness mapping revealed softening of both macro- and microvascular ECs upon dasatinib treatment, which was not observed in response to imatinib. In a dose-dependent manner, dasatinib decreased transendothelial electrical resistance/impedance and caused a permeability increase as well as disruption of tight adherens junctions in both cell types. In isolated perfused and ventilated rat lungs, dasatinib increased mean pulmonary arterial pressure, which was accompanied by a gain in lung weight. The Rho-kinase inhibitor Y27632 partly reversed the dasatinib-induced changes in vitro and ex vivo, presumably by acting downstream of Src. Co-administration of the Rho-kinase inhibitor Y27632 completely blunted the increased pulmonary pressure in response to dasatinib. In conclusion, a dasatinib-induced permeability increase in human pulmonary arterial macro- and microvascular ECs might explain many of the adverse effects of dasatinib in patients. Rho-kinase inhibition might be suitable to ameliorate these effects.

  16. Rho-Kinase/ROCK as a Potential Drug Target for Vitreoretinal Diseases

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    Muneo Yamaguchi

    2017-01-01

    Full Text Available Rho-associated kinase (Rho-kinase/ROCK was originally identified as an effector protein of the G protein Rho. Its involvement in various diseases, particularly cancer and cardiovascular disease, has been elucidated, and ROCK inhibitors have already been applied clinically for cerebral vasospasm and glaucoma. Vitreoretinal diseases including diabetic retinopathy, age-related macular degeneration, and proliferative vitreoretinoapthy are still a major cause of blindness. While anti-VEGF therapy has recently been widely used for vitreoretinal disorders due to its efficacy, attention has been drawn to new unmet needs. The importance of ROCK in pathological vitreoretinal conditions has also been elucidated and is attracting attention as a potential therapeutic target. ROCK is involved in angiogenesis and hyperpermeability and also in the pathogenesis of various pathologies such as inflammation and fibrosis. It has been expected that ROCK inhibitors will become new molecular target drugs for vitreoretinal diseases. This review summarizes the recent progress on the mechanisms of action of ROCK and their applications in disease treatment.

  17. Rho kinase inhibitor fasudil mitigates high-cholesterol diet-induced hypercholesterolemia and vascular damage.

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    Abdali, Nibrass Taher; Yaseen, Awny H; Said, Eman; Ibrahim, Tarek M

    2017-04-01

    The current study was designed to investigate the potential beneficial therapeutic outcome of Rho kinase inhibitor (fasudil) against hypercholesterolemia-induced myocardial and vascular injury in rabbits together with diet modification. Sixteen male rabbits were randomly divided into four groups: normal control group which received standard rabbit chow, hypercholesterolemic control group, and treated groups which received cholesterol-rich rabbit chow (1.5% cholesterol) for 8 weeks. Treated groups received either fasudil (100 mg/kg/day) or rosuvastatin (2.5 mg/kg/day) starting from the ninth week for further 4 weeks with interruption of the cholesterol-rich chow. Biochemical assessment of serum cholesterol, triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and myocardial oxidative/antioxidant biomarkers malondialdehyde (MDA), superoxide dismutase (SOD), and reduced glutathione (GSH), besides biochemical assessment of serum nitric oxide (NO), creatine kinase (CK), and lactate dehydrogenase (LDH) activities and serum total antioxidant capacity (TAC), was conducted. Serum vascular cell adhesion molecule 1 (VCAM-1) and serum Rho-associated protein kinase 1 (ROCK-1) were also evaluated along with histopathological examination of aorta specimens. Fasudil administration significantly decreased serum cholesterol, triglyceride (TG), and LDL and significantly increased serum HDL, with concomitant decrease in serum CK and LDH activities, NO, and restoration of serum TAC. Myocardial MDA significantly declined; SOD activity and GSH contents were restored. Serum ROCK-1 and VCAM-1 levels significantly declined as well. Vascular improvement was confirmed with histopathological examination, which revealed normal aortic intema with the absence of atheromas. Fasudil has promising anti-atherogenic activity mediated primarily via alleviation of hypercholesterolemia-induced oxidative stress and modulation of inflammatory response.

  18. Rho-kinase inhibitor and nicotinamide adenine dinucleotide phosphate oxidase inhibitor prevent impairment of endothelium-dependent cerebral vasodilation by acute cigarette smoking in rats.

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    Iida, Hiroki; Iida, Mami; Takenaka, Motoyasu; Fukuoka, Naokazu; Dohi, Shuji

    2008-06-01

    We previously reported that acute cigarette smoking can cause a dysfunction of endothelium-dependent vasodilation in cerebral vessels, and that blocking the angiotensin II (Ang II) type 1 (AT1) receptor with valsartan prevented this impairment. Our aim was to investigate the effects of a Rho-kinase inhibitor (fasudil) and a Nicotinamide Adenine Dinucleotide PHosphate (NADPH) oxidase inhibitor (apocynin) on smoking-induced endothelial dysfunction in cerebral arterioles. In Sprague-Dawley rats, we used a closed cranial window preparation to measure changes in pial vessel diameters following topical acetylcholine (ACh) before smoking. After one-minute smoking, we again examined the arteriolar responses to ACh. Finally, after intravenous fasudil or apocynin pre-treatment we re-examined the vasodilator responses to topical ACh (before and after cigarette smoking). Under control conditions, cerebral arterioles were dose-dependently dilated by topical ACh (10(-6) M and 10(-5) M). One hour after a one-minute smoking (1 mg-nicotine cigarette), 10(-5) M ACh constricted cerebral arterioles. However, one hour after a one-minute smoking, 10(-5) M ACh dilated cerebral pial arteries both in the fasudil pre-treatment and the apocynin pre-treatment groups, responses that were significantly different from those obtained without fasudil or apocynin pre-treatment. Thus, inhibition of Rho-kinase and NADPH oxidase activities may prevent the above smoking-induced impairment of endothelium-dependent vasodilation.

  19. The atypical structure and function of newborn arterial endothelium is mediated by Rho/Rho kinase signaling.

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    Flavahan, Sheila; Flavahan, Nicholas A

    2014-08-15

    Endothelium of fetal or newborn arteries is atypical, displaying actin stress fibers and reduced nitric oxide (NO)-mediated dilatation. This study tested the hypothesis that Rho/Rho kinase signaling, which promotes endothelial stress fibers and inhibits endothelial dilatation, contributed to this phenotype. Carotid arteries were isolated from newborn [postnatal day 1 (P1)], P7, and P21 mice. Endothelial dilatation to acetylcholine (pressure myograph) was minimal at P1, increased at P7, and further increased at P21. Inhibition of Rho (C3 transferase) or Rho kinase (Y27632, fasudil) significantly increased dilatation to acetylcholine in P1 arteries but had no effect in P7 or P21 arteries. After inhibition of NO synthase (N(G)-nitro-l-arginine methyl ester), Rho kinase inhibition no longer increased acetylcholine responses in P1 arteries. Rho kinase inhibition did not affect dilatation to the NO donor DEA-NONOate. The endothelial actin cytoskeleton was labeled with phalloidin and visualized by laser-scanning microscopy. In P1 arteries, the endothelium had prominent transcytoplasmic stress fibers, whereas in P7 and P21 arteries, the actin fibers had a significantly reduced intensity and were restricted to cell borders. Phosphorylation of myosin light chains, a Rho kinase substrate, was highest in P1 endothelium and significantly reduced in P7 and P21 endothelium (laser-scanning microscopy). In P1 arteries, inhibition of Rho (C3 transferase) or Rho kinase (Y27632) significantly reduced the intensity of actin fibers, which were restricted to cell borders. Similarly, in P1 arteries, Rho inhibition significantly reduced endothelial levels of phosphorylated myosin light chains. These results indicate that the atypical function and morphology of newborn endothelium is mediated by Rho/Rho kinase signaling. Copyright © 2014 the American Physiological Society.

  20. A proteomic approach for comprehensively screening substrates of protein kinases such as Rho-kinase.

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    Mutsuki Amano

    Full Text Available BACKGROUND: Protein kinases are major components of signal transduction pathways in multiple cellular processes. Kinases directly interact with and phosphorylate downstream substrates, thus modulating their functions. Despite the importance of identifying substrates in order to more fully understand the signaling network of respective kinases, efficient methods to search for substrates remain poorly explored. METHODOLOGY/PRINCIPAL FINDINGS: We combined mass spectrometry and affinity column chromatography of the catalytic domain of protein kinases to screen potential substrates. Using the active catalytic fragment of Rho-kinase/ROCK/ROK as the model bait, we obtained about 300 interacting proteins from the rat brain cytosol fraction, which included the proteins previously reported as Rho-kinase substrates. Several novel interacting proteins, including doublecortin, were phosphorylated by Rho-kinase both in vitro and in vivo. CONCLUSIONS/SIGNIFICANCE: This method would enable identification of novel specific substrates for kinases such as Rho-kinase with high sensitivity.

  1. Peptide substrates for Rho-associated kinase 2 (Rho-kinase 2/ROCK2.

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    Jeong-Hun Kang

    Full Text Available Peptide substrates sensitive for a certain protein kinase could be important for new-drug development and to understand the mechanism of diseases. Rho-associated kinase (Rho-kinase/ROCK is a serine/threonine kinase, and plays an important part in cardiovascular disease, migration and invasion of tumor cells, and in neurological disorders. The purpose of this study was to find substrates with high affinity and sensitivity for ROCK2. We synthesized 136 peptide substrates from protein substrates for ROCK2 with different lengths and charged peptides. Incorporation of (32P [counts per minute (CPM] for each peptide substrate was determined by the radiolabel assay using [γ-(32P]ATP. When the top five peptide substrates showing high CPMs (R4, R22, R133, R134, and R135 were phosphorylated by other enzymes (PKA, PKCα, and ERK1, R22, R133, and R135 displayed the highest CPM level for ROCK2 compared with other enzymes, whereas R4 and R134 showed similar CPM levels for ROCK2 and PKCα. We hypothesize that R22, R133, and R135 can be useful peptide substrates for ROCK2.

  2. Design of Aminobenzothiazole Inhibitors of Rho Kinases 1 and 2 by Using Protein Kinase A as a Structure Surrogate.

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    Judge, Russell A; Vasudevan, Anil; Scott, Victoria E; Simler, Gricelda H; Pratt, Steve D; Namovic, Marian T; Putman, C Brent; Aguirre, Ana; Stoll, Vincent S; Mamo, Mulugeta; Swann, Steven I; Cassar, Steven C; Faltynek, Connie R; Kage, Karen L; Boyce-Rustay, Janel M; Hobson, Adrian D

    2018-03-16

    We describe the design, synthesis, and structure-activity relationships (SARs) of a series of 2-aminobenzothiazole inhibitors of Rho kinases (ROCKs) 1 and 2, which were optimized to low nanomolar potencies by use of protein kinase A (PKA) as a structure surrogate to guide compound design. A subset of these molecules also showed robust activity in a cell-based myosin phosphatase assay and in a mechanical hyperalgesia in vivo pain model. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Differential binding of RhoA, RhoB, and RhoC to protein kinase C-related kinase (PRK) isoforms PRK1, PRK2, and PRK3: PRKs have the highest affinity for RhoB.

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    Hutchinson, Catherine L; Lowe, Peter N; McLaughlin, Stephen H; Mott, Helen R; Owen, Darerca

    2013-11-12

    Protein kinase C-related kinases (PRKs) are members of the protein kinase C superfamily of serine-threonine kinases and can be activated by binding to members of the Rho family of GTPases via a Rho-binding motif known as an HR1 domain. Three tandem HR1 domains reside at the N-terminus of the PRKs. We have assessed the ability of the HR1a and HR1b domains from the three PRK isoforms (PRK1, PRK2, and PRK3) to interact with the three Rho isoforms (RhoA, RhoB, and RhoC). The affinities of RhoA and RhoC for a construct encompassing both PRK1 HR1 domains were similar to those for the HR1a domain alone, suggesting that these interactions are mediated solely by the HR1a domain. The affinities of RhoB for both the PRK1 HR1a domain and the HR1ab didomain were higher than those of RhoA or RhoC. RhoB also bound more tightly to the didomain than to the HR1a domain alone, implicating the HR1b domain in the interaction. As compared with PRK1 HR1 domains, PRK2 and PRK3 domains bind less well to all Rho isoforms. Uniquely, however, the PRK3 domains display a specificity for RhoB that requires both the C-terminus of RhoB and the PRK3 HR1b domain. The thermal stability of the HR1a and HR1b domains was also investigated. The PRK2 HR1a domain was found to be the most thermally stable, while PRK2 HR1b, PRK3 HR1a, and PRK3 HR1b domains all exhibited lower melting temperatures, similar to that of the PRK1 HR1a domain. The lower thermal stability of the PRK2 and PRK3 HR1b domains may impart greater flexibility, driving their ability to interact with Rho isoforms.

  4. Infralimbic cortex Rho-kinase inhibition causes antidepressant-like activity in rats.

    Science.gov (United States)

    Inan, Salim Yalcin; Soner, Burak Cem; Sahin, Ayse Saide

    2015-03-03

    Depression is one of the most common psychiatric disorders in the world; however, its mechanisms remain unclear. Recently, a new signal-transduction pathway, namely Rho/Rho-kinase signalling, has been suggested to be involved in diverse cellular events in the central nervous system; such as epilepsy, anxiety-related behaviors, regulation of dendritic and axonal morphology, antinociception, subarachnoid haemorrhage, spinal cord injury and amyotrophic lateral sclerosis. However there is no evidence showing the involvement of Rho-kinase pathway in depression. In addition, the infralimbic cortex, rodent equivalent to subgenual cingulate cortex has been shown to be responsible for emotional responses. Thus, in the present study, intracranial guide cannulae were stereotaxically implanted bilaterally into the infralimbic cortex, and the effects of repeated microinjections of a Rho-kinase (ROCK) inhibitor Y-27632 (10 nmol) were investigated in rats. Y-27632 significantly decreased immobility time and increased swimming and climbing behaviors when compared to fluoxetine (10 μg) and saline groups in the forced swim test. In addition, Y-27632 treatment did not affect spontaneous locomotor activity and forelimb use in the open-field and cylinder tests respectively; but it enhanced limb placing accuracy in the ladder rung walking test. Our results suggest that Y-27632 could be a potentially active antidepressant agent. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Involvement of Rho-kinase in cold ischemia-reperfusion injury after liver transplantation in rats.

    Science.gov (United States)

    Shiotani, Satoko; Shimada, Mitsuo; Suehiro, Taketoshi; Soejima, Yuji; Yosizumi, Tomoharu; Shimokawa, Hiroaki; Maehara, Yoshihiko

    2004-08-15

    Reperfusion of ischemic tissues is known to cause the generation of reactive oxygen species (ROS) with resultant tissue damage. However, the sources of ROS in reperfused tissues are not fully characterized. We hypothesized that the small GTPase Rho and its target effector Rho-kinase/ROK/ROCK are involved in the oxidative burst in reperfused tissue with resultant reperfusion injury. In an in vivo rat model of liver transplantation using cold ischemia for 12 hr followed by reperfusion, a specific Rho-kinase inhibitor, fasudil (30 mg/kg), was administered orally 1 hr before the transplantation. Fasudil suppressed the ischemia-reperfusion (I/R)-induced generation of ROS after reperfusion (P<0.01) and also suppressed the release of inflammatory cytokines (tumor necrosis factor-alpha, interleukin-1beta) 3 hr after reperfusion, resulting in a significant reduction of I/R-induced hepatocellular injury (P<0.05), necrosis, apoptosis (P<0.01), and neutrophil infiltration (P<0.0001) 12 hr after reperfusion. All animals receiving a graft without fasudil died within 3 days, whereas 40% of those receiving fasudil survived (P<0.001). The present study demonstrates that Rho-kinase-mediated production of ROS and inflammatory cytokines are substantially involved in the pathogenesis of hepatocellular necrosis and apoptosis induced by cold I/R in vivo and that Rho-kinase may be regarded as a novel therapeutic target for the disorder.

  6. New therapeutic modality for corneal endothelial disease using Rho-associated kinase inhibitor eye drops.

    Science.gov (United States)

    Koizumi, Noriko; Okumura, Naoki; Ueno, Morio; Kinoshita, Shigeru

    2014-11-01

    Corneal endothelial dysfunction accompanied by visual disturbance is a primary indication for corneal endothelial transplantation. However, despite the value and potential of endothelial graft surgery, a strictly pharmacological approach for treating corneal endothelial dysfunction remains an attractive proposition. Previously, we reported that the selective Rho-associated kinase (ROCK) inhibitor Y-27632 promotes cell adhesion and proliferation, and inhibits the apoptosis of primate corneal endothelial cells in culture. These findings have led us to develop a novel medical treatment for the early phase of corneal endothelial disease using ROCK inhibitor eye drops. In rabbit and monkey models of partial endothelial dysfunction, we showed that corneal endothelial wound healing was accelerated via the topical application of ROCK inhibitor to the ocular surface, resulting in the regeneration of a corneal endothelial monolayer with a high endothelial cell density. Based on these animal studies, we are now attempting to advance the clinical application of ROCK inhibitor eye drops for patients with corneal endothelial dysfunction. A pilot clinical study was performed at the Kyoto Prefectural University of Medicine, and the effects of Y-27632 eye drops after transcorneal freezing were evaluated in 8 patients with corneal endothelial dysfunction. We observed a positive effect of ROCK inhibitor eye drops in treating patients with central edema caused by Fuchs corneal endothelial dystrophy. We believe that our new findings will contribute to the establishment of a new approach for the treatment of corneal endothelial dysfunction.

  7. Crosstalk between Substrates and Rho-Associated Kinase Inhibitors in Cryopreservation of Tissue-Engineered Constructs

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    Arindam Bit

    2017-01-01

    Full Text Available It is documented that human mesenchymal stem cells (hMSCs can be differentiated into various types of cells to present a tool for tissue engineering and regenerative medicine. Thus, the preservation of stem cells is a crucial factor for their effective long-term storage that further facilitates their continuous supply and transportation for application in regenerative medicine. Cryopreservation is the most important, practicable, and the only established mechanism for long-term preservation of cells, tissues, and organs, and engineered tissues; thus, it is the key step for the improvement of tissue engineering. A significant portion of MSCs loses cellular viability while freeze-thawing, which represents an important technical limitation to achieving sufficient viable cell numbers for maximum efficacy. Several natural and synthetic materials are extensively used as substrates for tissue engineering constructs and cryopreservation because they promote cell attachment and proliferation. Rho-associated kinase (ROCK inhibitors can improve the physiological function and postthaw viability of cryopreserved MSCs. This review proposes a crosstalk between substrate topology and interaction of cells with ROCK inhibitors. It is shown that incorporation of ionic nanoparticles in the presence of an external electrical field improves the generation of ROCK inhibitors to safeguard cellular viability for the enhanced cryopreservation of engineered tissues.

  8. Leiomyoma Cells in 3-Dimensional Cultures Demonstrate an Attenuated Response to Fasudil, a Rho-Kinase Inhibitor, When Compared to 2-Dimensional Cultures

    Science.gov (United States)

    Malik, Minnie; Britten, Joy; Segars, James

    2014-01-01

    Uterine leiomyomata are common benign tumors in women of reproductive age and demonstrate an attenuated response to mechanical signaling that involves Rho and integrins. To further characterize the impairment in Rho signaling, we studied the effect of Rho-kinase inhibitor, fasudil, on extracellular matrix production, in 2-dimensional (2D) and 3-dimensional (3D) cultures of leiomyoma and myometrial cells. Leiomyoma 2D cultures demonstrated a rapid decrease in gene transcripts and protein for fibronectin, procollagen 1A, and versican. In 3D cultures, fibronectin and procollagen 1A proteins demonstrated increased levels at lower concentrations of fasudil, followed by a concentration-dependent decrease. Versican protein increased up to 3-fold, whereas fibromodulin demonstrated a significant decrease of 1.92-fold. Myometrial 2D or 3D cultures demonstrated a decrease in all proteins after 72 hours of treatment. The 3D leiomyoma cultures demonstrated a significant increase in active RhoA, followed by a concentration-dependent decrease at higher concentrations. A concentration-dependent increase in phospho-extracellular regulated signal kinase and proapoptotic protein Bax was observed in 3D leiomyoma cultures. Fasudil relaxed the contraction of the 3D collagen gels caused by myometrium and leiomyoma cell growth. These findings indicate that the altered state of Rho signaling in leiomyoma was more clearly observed in 3D cultures. The results also suggest that fasudil may have clinical applicability for treatment of uterine leiomyoma. PMID:25084783

  9. Diacylglycerol kinase ζ regulates RhoA activation via a kinase-independent scaffolding mechanism

    DEFF Research Database (Denmark)

    Ard, Ryan; Mulatz, Kirk; Abramovici, Hanan

    2012-01-01

    , but the underlying mechanisms are unclear. Diacylglycerol kinase ζ (DGKζ), which phosphorylates diacylglycerol to yield phosphatidic acid, selectively dissociates Rac1 by stimulating PAK1-mediated phosphorylation of RhoGDI on Ser-101/174. Similarly, phosphorylation of RhoGDI on Ser-34 by protein kinase Cα (PKCα......GDI and was required for efficient interaction of PKCα and RhoA. DGKζ-null fibroblasts had condensed F-actin bundles and altered focal adhesion distribution, indicative of aberrant RhoA signaling. Two targets of the RhoA effector ROCK showed reduced phosphorylation in DGKζ-null cells. Collectively our findings suggest...

  10. Role of contractile prostaglandins and Rho-kinase in growth factor-induced airway smooth muscle contraction

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    Zaagsma Johan

    2005-07-01

    Full Text Available Abstract Background In addition to their proliferative and differentiating effects, several growth factors are capable of inducing a sustained airway smooth muscle (ASM contraction. These contractile effects were previously found to be dependent on Rho-kinase and have also been associated with the production of eicosanoids. However, the precise mechanisms underlying growth factor-induced contraction are still unknown. In this study we investigated the role of contractile prostaglandins and Rho-kinase in growth factor-induced ASM contraction. Methods Growth factor-induced contractions of guinea pig open-ring tracheal preparations were studied by isometric tension measurements. The contribution of Rho-kinase, mitogen-activated protein kinase (MAPK and cyclooxygenase (COX to these reponses was established, using the inhibitors Y-27632 (1 μM, U-0126 (3 μM and indomethacin (3 μM, respectively. The Rho-kinase dependency of contractions induced by exogenously applied prostaglandin F2α (PGF2α and prostaglandin E2 (PGE2 was also studied. In addition, the effects of the selective FP-receptor antagonist AL-8810 (10 μM and the selective EP1-antagonist AH-6809 (10 μM on growth factor-induced contractions were investigated, both in intact and epithelium-denuded preparations. Growth factor-induced PGF2α-and PGE2-release in the absence and presence of Y-27632, U-0126 and indomethacin, was assessed by an ELISA-assay. Results Epidermal growth factor (EGF-and platelet-derived growth factor (PDGF-induced contractions of guinea pig tracheal smooth muscle preparations were dependent on Rho-kinase, MAPK and COX. Interestingly, growth factor-induced PGF2α-and PGE2-release from tracheal rings was significantly reduced by U-0126 and indomethacin, but not by Y-27632. Also, PGF2α-and PGE2-induced ASM contractions were largely dependent on Rho-kinase, in contrast to other contractile agonists like histamine. The FP-receptor antagonist AL-8810 (10 μM significantly

  11. Involvement of Rho kinase in the pathogenesis of acute pulmonary embolism-induced polystyrene microspheres in rats.

    Science.gov (United States)

    Toba, M; Nagaoka, T; Morio, Y; Sato, K; Uchida, K; Homma, N; Takahashi, K

    2010-03-01

    Acute pulmonary embolism (PE) is a life-threatening disease, and several vasoconstrictors, including endothelin-1 (ET-1), play a key role in vasoconstriction and hypoxemia during the development of PE. Rho kinase is activated by various vasoconstrictors resulting in vascular contraction and remodeling. Recent evidence has revealed an important role of Rho kinase in the pathogenesis of systemic and pulmonary vascular diseases. However, contribution of Rho kinase in PE remains unclear. We thus investigated the role of Rho kinase in the PE rat model induced by intrajugular administration of polystyrene microspheres (mean diameter, 26 microm). At 6 h following the administration of microspheres (1.5 ml/kg), right ventricular systolic pressure (RVSP) was higher in the PE than in the control rats (15.8 +/- 1.6 vs. 32.9 +/- 7.5 mmHg). Arterial oxygen tension was lower (92.3 +/- 12.5 vs. 66.0 +/- 17.7 Torr), and alveolar-arterial difference in oxygen partial pressure was higher (3.9 +/- 3.8 vs. 36.5 +/- 26.9 Torr) in the PE rats. Western blotting analysis revealed upregulation and downregulation in expression of vascular cell adhesion molecule-1 and endothelial nitric oxide synthase in lungs from the PE rats, respectively, and radioimmunoassay demonstrated an increase in plasma ET-1 levels. Lung Rho kinase alpha expression was greater in the PE rats. At 5 h following administration of microspheres (0.75 ml/kg), intravenous Rho kinase inhibitors HA1077 and Y27632 (3 mg/kg each) attenuated elevation of RVSP (22.0 +/- 3.7, 17.1 +/- 3.2, 14.3 +/- 2.6 mmHg, PE, PE+HA1077, PE+Y27632) and the severity of hypoxemia (66.3 +/- 16.2, 94.9 +/- 23.0, 89.1 +/- 8.5 Torr, PE, PE+HA1077, PE+Y27632) in the PE rats. These results suggest that pulmonary endothelial dysfunction and activation of Rho kinase may contribute to the potentiation of vasoconstriction and hypoxemia in the PE rats.

  12. Rational Design of Rho Protein Inhibitors

    National Research Council Canada - National Science Library

    Rojas, Rafael J

    2006-01-01

    ... nucleotide exchange factors (RhoGEFs). We have developed a high throughput screening strategy identify novel inhibitors of Rho activation are currently following up on several compounds which appear to selectively inhibit Rho activation. These compounds may form the basis of future drug development strategies for the treatment of metastatic breast cancer.

  13. Rational Design of Rho Protein Inhibitors

    National Research Council Canada - National Science Library

    Rojas, Rafael J

    2005-01-01

    ... nucleotide exchange factors (RhoGEFs). We have developed a high throughput screening strategy identify novel inhibitors of Rho activation are currently following up on several compounds which appear to selectively inhibit Rho activation. These compounds may form the basis of future drug development strategies for the treatment of metastatic breast cancer.

  14. Development of Poly Lactic/Glycolic Acid (PLGA Microspheres for Controlled Release of Rho-Associated Kinase Inhibitor

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    Sho Koda

    2017-01-01

    Full Text Available Purpose. The purpose of this study was to investigate the feasibility of poly lactic/glycolic acid (PLGA as a drug delivery carrier of Rho kinase (ROCK inhibitor for the treatment of corneal endothelial disease. Method. ROCK inhibitor Y-27632 and PLGA were dissolved in water with or without gelatin (W1, and a double emulsion [(W1/O/W2] was formed with dichloromethane (O and polyvinyl alcohol (W2. Drug release curve was obtained by evaluating the released Y-27632 by using high performance liquid chromatography. PLGA was injected into the anterior chamber or subconjunctiva in rabbit eyes, and ocular complication was evaluated by slitlamp microscope and histological analysis. Results. Y-27632 incorporated PLGA microspheres with different molecular weights, and different composition ratios of lactic acid and glycolic acid were fabricated. A high molecular weight and low content of glycolic acid produced a slower and longer release. The Y-27632 released from PLGA microspheres significantly promoted the cell proliferation of cultured corneal endothelial cells. The injection of PLGA did not induce any evident eye complication. Conclusions. ROCK inhibitor-incorporated PLGA microspheres were fabricated, and the microspheres achieved the sustained release of ROCK inhibitor over 7–10 days in vitro. Our data should encourage researchers to use PLGA microspheres for treating corneal endothelial diseases.

  15. Rho Kinase ROCK2 Mediates Acid-Induced NADPH Oxidase NOX5-S Expression in Human Esophageal Adenocarcinoma Cells.

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    Jie Hong

    Full Text Available Mechanisms of the progression from Barrett's esophagus (BE to esophageal adenocarcinoma (EA are not fully understood. We have shown that NOX5-S may be involved in this progression. However, how acid upregulates NOX5-S is not well known. We found that acid-induced increase in NOX5-S expression was significantly decreased by the Rho kinase (ROCK inhibitor Y27632 in BE mucosal biopsies and FLO-1 EA cells. In addition, acid treatment significantly increased the Rho kinase activity in FLO-1 cells. The acid-induced increase in NOX5-S expression and H2O2 production was significantly decreased by knockdown of Rho kinase ROCK2, but not by knockdown of ROCK1. Conversely, the overexpression of the constitutively active ROCK2, but not the constitutively active ROCK1, significantly enhanced the NOX5-S expression and H2O2 production. Moreover, the acid-induced increase in Rho kinase activity and in NOX5-S mRNA expression was blocked by the removal of calcium in both FLO-1 and OE33 cells. The calcium ionophore A23187 significantly increased the Rho kinase activity and NOX5-S mRNA expression. We conclude that acid-induced increase in NOX5-S expression and H2O2 production may depend on the activation of ROCK2, but not ROCK1, in EA cells. The acid-induced activation of Rho kinase may be mediated by the intracellular calcium increase. It is possible that persistent acid reflux present in BE patients may increase the intracellular calcium, activate ROCK2 and thereby upregulate NOX5-S. High levels of reactive oxygen species derived from NOX5-S may cause DNA damage and thereby contribute to the progression from BE to EA.

  16. Rho-associated kinase is a therapeutic target in neuroblastoma.

    Science.gov (United States)

    Dyberg, Cecilia; Fransson, Susanne; Andonova, Teodora; Sveinbjörnsson, Baldur; Lännerholm-Palm, Jessika; Olsen, Thale K; Forsberg, David; Herlenius, Eric; Martinsson, Tommy; Brodin, Bertha; Kogner, Per; Johnsen, John Inge; Wickström, Malin

    2017-08-08

    Neuroblastoma is a peripheral neural system tumor that originates from the neural crest and is the most common and deadly tumor of infancy. Here we show that neuroblastoma harbors frequent mutations of genes controlling the Rac/Rho signaling cascade important for proper migration and differentiation of neural crest cells during neuritogenesis. RhoA is activated in tumors from neuroblastoma patients, and elevated expression of Rho-associated kinase (ROCK)2 is associated with poor patient survival. Pharmacological or genetic inhibition of ROCK1 and 2, key molecules in Rho signaling, resulted in neuroblastoma cell differentiation and inhibition of neuroblastoma cell growth, migration, and invasion. Molecularly, ROCK inhibition induced glycogen synthase kinase 3β-dependent phosphorylation and degradation of MYCN protein. Small-molecule inhibition of ROCK suppressed MYCN -driven neuroblastoma growth in TH- MYCN homozygous transgenic mice and MYCN gene-amplified neuroblastoma xenograft growth in nude mice. Interference with Rho/Rac signaling might offer therapeutic perspectives for high-risk neuroblastoma.

  17. Yersinia Virulence Depends on Mimicry of Host Rho-Family Nucleotide Dissociation Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Prehna,G.; Ivanov, M.; Blisha, J.; Stebbins, C.

    2006-01-01

    Yersinia spp. cause gastroenteritis and the plague, representing historically devastating pathogens that are currently an important biodefense and antibiotic resistance concern. A critical virulence determinant is the Yersinia protein kinase A, or YpkA, a multidomain protein that disrupts the eukaryotic actin cytoskeleton. Here we solve the crystal structure of a YpkA-Rac1 complex and find that YpkA possesses a Rac1 binding domain that mimics host guanidine nucleotide dissociation inhibitors (GDIs) of the Rho GTPases. YpkA inhibits nucleotide exchange in Rac1 and RhoA, and mutations that disrupt the YpkA-GTPase interface abolish this activity in vitro and impair in vivo YpkA-induced cytoskeletal disruption. In cell culture experiments, the kinase and the GDI domains of YpkA act synergistically to promote cytoskeletal disruption, and a Y. pseudotuberculosis mutant lacking YpkA GDI activity shows attenuated virulence in a mouse infection assay. We conclude that virulence in Yersinia depends strongly upon mimicry of host GDI proteins by YpkA.

  18. HSP90 inhibitors potentiate PGF2α-induced IL-6 synthesis via p38 MAP kinase in osteoblasts.

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    Kazuhiko Fujita

    Full Text Available Heat shock protein 90 (HSP90 that is ubiquitously expressed in various tissues, is recognized to be a major molecular chaperone. We have previously reported that prostaglandin F2α (PGF2α, a potent bone remodeling mediator, stimulates the synthesis of interleukin-6 (IL-6 through p44/p42 mitogen-activated protein (MAP kinase and p38 MAP kinase in osteoblast-like MC3T3-E1 cells, and that Rho-kinase acts at a point upstream of p38 MAP kinase. In the present study, we investigated the involvement of HSP90 in the PGF2α-stimulated IL-6 synthesis and the underlying mechanism in MC3T3-E1 cells. Geldanamycin, an inhibitor of HSP90, significantly amplified both the PGF2α-stimulated IL-6 release and the mRNA expression levels. In addition, other HSP90 inhibitors, 17-allylamino-17demethoxy-geldanamycin (17-AAG and 17-dimethylamino-ethylamino-17-demethoxy-geldanamycin (17-DMAG and onalespib, enhanced the PGF2α-stimulated IL-6 release. Geldanamycin, 17-AAG and onalespib markedly strengthened the PGF2α-induced phosphorylation of p38 MAP kinase. Geldanamycin and 17-AAG did not affect the PGF2α-induced phosphorylation of p44/p42 MAP kinase and myosin phosphatase targeting subunit (MYPT-1, a substrate of Rho-kinase, and the protein levels of RhoA and Rho-kinase. In addition, HSP90-siRNA enhanced the PGF2α-induced phosphorylation of p38 MAP kinase. Furthermore, SB203580, an inhibitor of p38 MAP kinase, significantly suppressed the amplification by geldanamycin, 17-AAG or 17-DMAG of the PGF2α-stimulated IL-6 release. Our results strongly suggest that HSP90 negatively regulates the PGF2α-stimulated IL-6 synthesis in osteoblasts, and that the effect of HSP90 is exerted through regulating p38 MAP kinase activation.

  19. Restoration of uridine 5′-triphosphate-suppressed delayed rectifying K+ currents by an NO activator KMUP-1 involves RhoA/Rho kinase signaling in pulmonary artery smooth muscle cells

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    Zen-Kong Dai

    2016-12-01

    Full Text Available We have demonstrated that KMUP-1 (7-[2-[4-(2-chlorobenzenepiperazinyl]ethyl]-1,3-dimethylxanthine blunts monocrotaline-induced pulmonary arterial hypertension by altering Ca2+ sensitivity, K+-channel function, endothelial nitric oxide synthase activity, and RhoA/Rho kinase (ROCK expression. This study further investigated whether KMUP-1 impedes uridine 5′-triphosphate (UTP-inhibited delayed rectifying K+ (KDR current in rat pulmonary arteries involved the RhoA/ROCK signaling. Pulmonary artery smooth muscle cells (PASMCs were enzymatically dissociated from rat pulmonary arteries. KMUP-1 (30μM attenuated UTP (30μM-mediated membrane depolarization and abolished UTP-enhanced cytosolic Ca2+ concentration. Whole-cell patch-clamp electrophysiology was used to monitor KDR currents. A voltage-dependent KDR current was isolated and shown to consist of a 4-aminopyridine (5mM-sensitive component and an insensitive component. The 4-aminopyridine sensitive KDR current was suppressed by UTP (30μM. The ROCK inhibitor Y27632 (30μM abolished the ability of UTP to inhibit the KDR current. Like Y27632, KMUP-1 (30μM similarly abolished UTP-inhibited KDR currents. Superfused protein kinase A and protein kinase G inhibitors (KT5720, 300nM and KT5823, 300nM did not affect UTP-inhibited KDR currents, but the currents were restored by adding KMUP-1 (30μM to the superfusate. KMUP-1 reversal of KDR current inhibition by UTP predominantly involves the ROCK inhibition. The results indicate that the RhoA/ROCK signaling pathway plays a key role in eliciting PASMCs depolarization caused by UTP, which would result in pulmonary artery constriction. KMUP-1 blocks UTP-mediated PASMCs depolarization, suggesting that it would prevent abnormal pulmonary vasoconstriction.

  20. Allergic sensitization enhances the contribution of Rho-kinase to airway smooth muscle contraction

    NARCIS (Netherlands)

    Schaafsma, D.; Gosens, Reinout; Bos, I.S.T.; Meurs, Herman; Zaagsma, Hans; Nelemans, Herman

    2004-01-01

    1 Repeated allergen challenge has been shown to increase the role of Rho-kinase in airway smooth muscle (ASM) contraction. We considered the possibility that active allergic sensitization by itself, that is, without subsequent allergen exposure, could be sufficient to enhance Rho-kinase-mediated ASM

  1. Rho-associated kinase inhibitors promote the cardiac differentiation of embryonic and induced pluripotent stem cells.

    Science.gov (United States)

    Cheng, Ya-Ting; Yeih, Dong-Feng; Liang, Shu-Man; Chien, Chia-Ying; Yu, Yen-Ling; Ko, Bor-Sheng; Jan, Yee-Jee; Kuo, Cheng-Chin; Sung, Li-Ying; Shyue, Song-Kun; Chen, Ming-Fong; Yet, Shaw-Fang; Wu, Kenneth K; Liou, Jun-Yang

    2015-12-15

    Rho-associated kinase (ROCK) plays an important role in maintaining embryonic stem (ES) cell pluripotency. To determine whether ROCK is involved in ES cell differentiation into cardiac and hematopoietic lineages, we evaluated the effect of ROCK inhibitors, Y-27632 and fasudil on murine ES and induced pluripotent stem (iPS) cell differentiation. Gene expression levels were determined by real-time PCR, Western blot analysis and immunofluorescent confocal microscopy. Cell transplantation of induced differentiated cells were assessed in vivo in a mouse model (three groups, n=8/group) of acute myocardial infarction (MI). The cell engraftment was examined by immunohistochemical staining and the outcome was analyzed by echocardiography. Cells were cultured in hematopoietic differentiation medium in the presence or absence of ROCK inhibitor and colony formation as well as markers of ES, hematopoietic stem cells (HSC) and cells of cardiac lineages were analyzed. ROCK inhibition resulted in a drastic change in colony morphology accompanied by loss of hematopoietic markers (GATA-1, CD41 and β-Major) and expressed markers of cardiac lineages (GATA-4, Isl-1, Tbx-5, Tbx-20, MLC-2a, MLC-2v, α-MHC, cTnI and cTnT) in murine ES and iPS cells. Fasudil-induced cardiac progenitor (Mesp-1 expressing) cells were infused into a murine MI model. They engrafted into the peri-infarct and infarct regions and preserved left ventricular function. These findings provide new insights into the signaling required for ES cell differentiation into hematopoietic as well as cardiac lineages and suggest that ROCK inhibitors are useful in directing iPS cell differentiation into cardiac progenitor cells for cell therapy of cardiovascular diseases. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Activation of G protein-coupled estrogen receptor 1 induces coronary artery relaxation via Epac/Rap1-mediated inhibition of RhoA/Rho kinase pathway in parallel with PKA.

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    Xuan Yu

    Full Text Available Previously, we reported that cAMP/PKA signaling is involved in GPER-mediated coronary relaxation by activating MLCP via inhibition of RhoA pathway. In the current study, we tested the hypothesis that activation of GPER induces coronary artery relaxation via inhibition of RhoA/Rho kinase pathway by cAMP downstream targets, exchange proteins directly activated by cAMP (Epac as well as PKA. Our results show that Epac inhibitors, brefeldin A (BFA, 50 μM, or ESI-09 (20 μM, or CE3F4 (100 μM, all partially inhibited porcine coronary artery relaxation response to the selective GPER agonist, G-1 (0.3-3 μM; while concurrent administration of BFA and PKI (5 μM, a PKA inhibitor, almost completely blocked the relaxation effect of G-1. The Epac specific agonist, 8-CPT-2Me-cAMP (007, 1-100 μM, induced a concentration-dependent relaxation response. Furthermore, the activity of Ras-related protein 1 (Rap1 was up regulated by G-1 (1 μM treatment of porcine coronary artery smooth muscle cells (CASMCs. Phosphorylation of vasodilator-stimulated phosphoprotein (p-VASP was elevated by G-1 (1 μM treatment, but not by 007 (50 μM; and the effect of G-1 on p-VASP was blocked by PKI, but not by ESI-09, an Epac antagonist. RhoA activity was similarly down regulated by G-1 and 007, whereas ESI-09 restored most of the reduced RhoA activity by G-1 treatment. Furthermore, G-1 decreased PGF2α-induced p-MYPT1, which was partially reversed with either ESI-09 or PKI; whereas, concurrent administration of ESI-09 and PKI totally prevented the inhibitory effect of G-1. The inhibitory effects of G-1 on p- MLC levels in CASMCs were mostly restored by either ESI-09 or PKI. These results demonstrate that activation of GPER induces coronary artery relaxation via concurrent inhibition of RhoA/Rho kinase by Epac/Rap1 and PKA. GPER could be a potential drug target for preventing and treating cardiovascular diseases.

  3. 1α,25-Dihydroxyvitamin D3 Ameliorates Seawater Aspiration-Induced Acute Lung Injury via NF-κB and RhoA/Rho Kinase Pathways

    Science.gov (United States)

    Liu, Wei; Wang, Li; Luo, Ying; Li, Zhichao; Jin, Faguang

    2014-01-01

    Introduction Inflammation and pulmonary edema are involved in the pathogenesis of seawater aspiration-induced acute lung injury (ALI). Although several studies have reported that 1α,25-Dihydroxyvitamin D3 (calcitriol) suppresses inflammation, it has not been confirmed to be effective in seawater aspiration-induced ALI. Thus, we investigated the effect of calcitriol on seawater aspiration-induced ALI and explored the probable mechanism. Methods Male SD rats receiving different doses of calcitriol or not, underwent seawater instillation. Then lung samples were collected at 4 h for analysis. In addition, A549 cells and rat pulmonary microvascular endothelial cells (RPMVECs) were cultured with calcitriol or not and then stimulated with 25% seawater for 40 min. After these treatments, cells samples were collected for analysis. Results Results from real-time PCR showed that seawater stimulation up-regulated the expression of vitamin D receptor in lung tissues, A549 cells and RPMVECs. Seawater stimulation also activates NF-κB and RhoA/Rho kinase pathways. However, we found that pretreatment with calcitriol significantly inhibited the activation of NF-κB and RhoA/Rho kinase pathways. Meanwhile, treatment of calcitriol also improved lung histopathologic changes, reduced inflammation, lung edema and vascular leakage. Conclusions These results demonstrated that NF-κB and RhoA/Rho kinase pathways are critical in the development of lung inflammation and pulmonary edema and that treatment with calcitriol could ameliorate seawater aspiration-induced ALI, which was probably through the inhibition of NF-κB and RhoA/Rho kinase pathways. PMID:25118599

  4. A negative modulatory role for rho and rho-associated kinase signaling in delamination of neural crest cells

    Directory of Open Access Journals (Sweden)

    Kalcheim Chaya

    2008-10-01

    Full Text Available Abstract Background Neural crest progenitors arise as epithelial cells and then undergo a process of epithelial to mesenchymal transition that precedes the generation of cellular motility and subsequent migration. We aim at understanding the underlying molecular network. Along this line, possible roles of Rho GTPases that act as molecular switches to control a variety of signal transduction pathways remain virtually unexplored, as are putative interactions between Rho proteins and additional known components of this cascade. Results We investigated the role of Rho/Rock signaling in neural crest delamination. Active RhoA and RhoB are expressed in the membrane of epithelial progenitors and are downregulated upon delamination. In vivo loss-of-function of RhoA or RhoB or of overall Rho signaling by C3 transferase enhanced and/or triggered premature crest delamination yet had no effect on cell specification. Consistently, treatment of explanted neural primordia with membrane-permeable C3 or with the Rock inhibitor Y27632 both accelerated and enhanced crest emigration without affecting cell proliferation. These treatments altered neural crest morphology by reducing stress fibers, focal adhesions and downregulating membrane-bound N-cadherin. Reciprocally, activation of endogenous Rho by lysophosphatidic acid inhibited emigration while enhancing the above. Since delamination is triggered by BMP and requires G1/S transition, we examined their relationship with Rho. Blocking Rho/Rock function rescued crest emigration upon treatment with noggin or with the G1/S inhibitor mimosine. In the latter condition, cells emigrated while arrested at G1. Conversely, BMP4 was unable to rescue cell emigration when endogenous Rho activity was enhanced by lysophosphatidic acid. Conclusion Rho-GTPases, through Rock, act downstream of BMP and of G1/S transition to negatively regulate crest delamination by modifying cytoskeleton assembly and intercellular adhesion.

  5. The role of Rho-kinase and calcium ions in constriction triggered by ET-1.

    Science.gov (United States)

    Wiciński, Michał; Szadujkis-Szadurska, Katarzyna; Węclewicz, Mateusz M; Malinowski, Bartosz; Matusiak, Grzegorz; Walczak, Maciej; Wódkiewicz, Eryk; Grześk, Grzegorz; Pawlak-Osińska, Katarzyna

    2018-05-05

    Endothelin-1 (ET-1) is one of the key factors regulating tension of smooth muscles in blood vessels. It is believed that ET-1 plays an important role in pathogenesis of hypertension, and cardiovascular diseases; therefore, research in order to limit ET-1-mediated action is still in progress. The main objective of this paper was to evaluate the role of Rho-kinase in the ET-1-induced constriction of arteries. The analysis also included significance of intra- and extracellular pool of calcium ions in constriction triggered by ET-1. The studies were performed on perfused Wistar rat tail arteries. Concentration response curve (CRC) was determined for ET-1 in the presence of increased concentrations of Rho-kinase inhibitor (Y-27632) and IP3-receptor antagonist (2APB), both in reference to constriction triggered by solely ET-1. Afterwards, the influence of calcium ions present in the perfusion fluid was evaluated in terms of the effect triggered by 2APB and occurring in arteries constricted by ET-1. ET-1, in concentration dependent manner, leads to increase in perfusion pressure. Y-27632 and 2APB lead to shift of the concentration response curve for ET-1 to the right with simultaneously lowered maximum effect. There was no difference in reaction of the artery constricted by ET-1 and treated with 2APB in solution containing calcium and in calcium-free solution. Vasoconstrictive action of endothelin is not significantly dependent on the inflow of extracellular calcium, but it is proportional to inflow of Ca 2+ related to activation of IP3 receptors and to Rho-kinase activity. Copyright © 2018. Published by Elsevier Inc.

  6. Sex differences in the enhanced responsiveness to acute angiotensin II in growth-restricted rats: role of fasudil, a Rho kinase inhibitor.

    Science.gov (United States)

    Ojeda, Norma B; Royals, Thomas P; Alexander, Barbara T

    2013-04-01

    This study tested the hypothesis that Rho kinase contributes to the enhanced pressor response to acute angiotensin II in intact male growth-restricted and gonadectomized female growth-restricted rats. Mean arterial pressure (MAP) and renal function were determined in conscious animals pretreated with enalapril (250 mg/l in drinking water) for 1 wk to block the endogenous renin-angiotensin system and normalize blood pressure (baseline). Blood pressure and renal hemodynamics did not differ at baseline. Acute Ang II (100 ng·kg(-1)·min(-1)) induced a greater increase in MAP and renal vascular resistance and enhanced reduction in glomerular filtration rate in intact male growth-restricted rats compared with intact male controls (P back to baseline in male growth-restricted rats, and yet glomerular filtration rate remained significantly reduced (P < 0.05). Thus, these data suggest a role for enhanced renal sensitivity to acute Ang II in the developmental programming of hypertension in male growth-restricted rats. However, inhibition of Rho kinase had no effect on the basal or enhanced increase in blood pressure induced by acute Ang II in the gonadectomized female growth-restricted rat. Therefore, these studies suggest that Rho kinase inhibition exerts a sex-specific effect on blood pressure sensitivity to acute Ang II in growth-restricted rats.

  7. The Rho kinases I and II regulate different aspects of myosin II activity

    DEFF Research Database (Denmark)

    Yoneda, Atsuko; Multhaupt, Hinke A B; Couchman, John R

    2005-01-01

    The homologous mammalian rho kinases (ROCK I and II) are assumed to be functionally redundant, based largely on kinase construct overexpression. As downstream effectors of Rho GTPases, their major substrates are myosin light chain and myosin phosphatase. Both kinases are implicated in microfilament...... bundle assembly and smooth muscle contractility. Here, analysis of fibroblast adhesion to fibronectin revealed that although ROCK II was more abundant, its activity was always lower than ROCK I. Specific reduction of ROCK I by siRNA resulted in loss of stress fibers and focal adhesions, despite...

  8. Tetramethylpyrazine Protects Against Oxygen-Glucose Deprivation-Induced Brain Microvascular Endothelial Cells Injury via Rho/Rho-kinase Signaling Pathway.

    Science.gov (United States)

    Yang, Guang; Qian, Chen; Wang, Ning; Lin, Chenyu; Wang, Yan; Wang, Guangyun; Piao, Xinxin

    2017-05-01

    Tetramethylpyrazine (TMP, also known as Ligustrazine), which is isolated from Chinese Herb Medicine Ligustium wollichii Franchat (Chuan Xiong), has been widely used in China for the treatment of ischemic stroke by Chinese herbalists. Brain microvascular endothelial cells (BMECs) are the integral parts of the blood-brain barrier (BBB), protecting BMECs against oxygen-glucose deprivation (OGD) which is important for the treatment of ischemic stroke. Here, we investigated the protective mechanisms of TMP, focusing on OGD-injured BMECs and the Rho/Rho-kinase (Rho-associated kinases, ROCK) signaling pathway. The model of OGD-injured BMECs was established in this study. BMECs were identified by von Willebrand factor III staining and exposed to fasudil, or TMP at different concentrations (14.3, 28.6, 57.3 µM) for 2 h before 24 h of OGD injury. The effect of each treatment was examined by cell viability assays, measurement of intracellular reactive oxygen species (ROS), and transendothelial electric resistance and western blot analysis (caspase-3, endothelial nitric oxide synthase (eNOS), RhoA, Rac1). Our results show that TMP significantly attenuated apoptosis and the permeability of BMECs induced by OGD. In addition, TMP could notably down-regulate the characteristic proteins in Rho/ROCK signaling pathway such as RhoA and Rac1, which triggered abnormal changes of eNOS and ROS, respectively. Altogether, our results show that TMP has a strong protective effect against OGD-induced BMECs injury and suggest that the mechanism might be related to the inhibition of the Rho/ROCK signaling pathway.

  9. Effects of 17β-estradiol and progesterone on the production of adipokines in differentiating 3T3-L1 adipocytes: Role of Rho-kinase.

    Science.gov (United States)

    Pektaş, Mehtap; Kurt, Akif Hakan; Ün, İsmail; Tiftik, Rukiye Nalan; Büyükafşar, Kansu

    2015-04-01

    Effect of female sex hormones on the production/release of adipocyte-derived cytokines has been debatable. Furthermore, whether the cellular signaling triggered by these hormones involve Rho-kinase has not been investigated yet. Therefore, in this study, effects of 17β-estradiol and progesterone as well as the Rho-kinase inhibitor, Y-27632 on the level of adipokines such as resistin, adiponectin, leptin, TNF-α and IL-6 were investigated in 3T3-L1-derived adipocytes. Differentiation was induced in the post-confluent preadipocytes by the standard differentiation medium (Dulbecco's modified Eagle's medium with 10% fetal bovine serum together with the mixture of isobutylmethylxanthine, dexamethasone and insulin) in the presence of 17β-estradiol (10(-8)-10(-7)M), progesterone (10(-6)-10(-5)M), the Rho-kinase inhibitor, Y-27632 (10(-5)M) and their combination for 8days. Measurements of the adipokines were performed in the culturing medium by ELISA kits using specific monoclonal antibodies. 17β-estradiol elevated resistin but decreased adiponectin and IL-6 levels; however, it did not alter the concentration of leptin and TNF-α. Y-27632 pretreatment inhibited the rise of resistin and the fall of adiponectin by 17β-estradiol without any effects by its own. Progesterone did not change resistin, leptin and TNF-α level; however, it elevated adiponectin and decreased IL-6 production. Neither 17β-estradiol nor Y-27632 was able to antagonize the increase of adiponectin and the reduction of IL-6 levels by progesterone. While Y-27632 alone lowered IL-6 level, it increased leptin and TNF-α concentration without altering resistin and adiponectin. In conclusion, 17β-estradiol could modify adipokine production in 3T3-L1 adipocytes with the actions some of which involve Rho-kinase mediation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Protein kinase C-α signals P115RhoGEF phosphorylation and RhoA activation in TNF-α-induced mouse brain microvascular endothelial cell barrier dysfunction

    Directory of Open Access Journals (Sweden)

    Deng Xiaolu

    2011-04-01

    Full Text Available Abstract Background Tumor necrosis factor-α (TNF-α, a proinflammatory cytokine, is capable of activating the small GTPase RhoA, which in turn contributes to endothelial barrier dysfunction. However, the underlying signaling mechanisms remained undefined. Therefore, we aimed to determine the role of protein kinase C (PKC isozymes in the mechanism of RhoA activation and in signaling TNF-α-induced mouse brain microvascular endothelial cell (BMEC barrier dysfunction. Methods Bend.3 cells, an immortalized mouse brain endothelial cell line, were exposed to TNF-α (10 ng/mL. RhoA activity was assessed by pull down assay. PKC-α activity was measured using enzyme assasy. BMEC barrier function was measured by transendothelial electrical resistance (TER. p115RhoGEF phosphorylation was detected by autoradiography followed by western blotting. F-actin organization was observed by rhodamine-phalloidin staining. Both pharmacological inhibitors and knockdown approaches were employed to investigate the role of PKC and p115RhoGEF in TNF-α-induced RhoA activation and BMEC permeability. Results We observed that TNF-α induces a rapid phosphorylation of p115RhoGEF, activation of PKC and RhoA in BMECs. Inhibition of conventional PKC by Gö6976 mitigated the TNF-α-induced p115RhoGEF phosphorylation and RhoA activation. Subsequently, we found that these events are regulated by PKC-α rather than PKC-β by using shRNA. In addition, P115-shRNA and n19RhoA (dominant negative mutant of RhoA transfections had no effect on mediating TNF-α-induced PKC-α activation. These data suggest that PKC-α but not PKC-β acts as an upstream regulator of p115RhoGEF phosphorylation and RhoA activation in response to TNF-α. Moreover, depletion of PKC-α, of p115RhoGEF, and inhibition of RhoA activation also prevented TNF-α-induced stress fiber formation and a decrease in TER. Conclusions Taken together, our results show that PKC-α phosphorylation of p115RhoGEF mediates TNF

  11. Endothelial microparticle formation by angiotensin II is mediated via Ang II receptor type I/NADPH oxidase/ Rho kinase pathways targeted to lipid rafts.

    Science.gov (United States)

    Burger, Dylan; Montezano, Augusto C; Nishigaki, Nobuhiro; He, Ying; Carter, Anthony; Touyz, Rhian M

    2011-08-01

    Circulating microparticles are increased in cardiovascular disease and may themselves promote oxidative stress and inflammation. Molecular mechanisms underlying their formation and signaling are unclear. We investigated the role of reactive oxygen species (ROS), Rho kinase, and lipid rafts in microparticle formation and examined their functional significance in endothelial cells (ECs). Microparticle formation from angiotensin II (Ang II)-stimulated ECs and apolipoprotein E(-/-) mice was assessed by annexin V or by CD144 staining and electron microscopy. Ang II promoted microparticle formation and increased EC O(2)(-) generation and Rho kinase activity. Ang II-stimulated effects were inhibited by irbesartan (Ang II receptor type I blocker) and fasudil (Rho kinase inhibitor). Methyl-β-cyclodextrin and nystatin, which disrupt lipid rafts/caveolae, blocked microparticle release. Functional responses, assessed in microparticle-stimulated ECs, revealed increased O(2)(-) production, enhanced vascular cell adhesion molecule/platelet-EC adhesion molecule expression, and augmented macrophage adhesion. Inhibition of epidermal growth factor receptor blocked the prooxidative and proinflammatory effects of microparticles. In vitro observations were confirmed in apolipoprotein E(-/-) mice, which displayed vascular inflammation and high levels of circulating endothelial microparticles, effects that were reduced by apocynin. We demonstrated direct actions of Ang II on endothelial microparticle release, mediated through NADPH oxidase, ROS, and Rho kinase targeted to lipid rafts. Microparticles themselves stimulated endothelial ROS formation and inflammatory responses. Our findings suggest a feedforward system whereby Ang II promotes EC injury through its own endothelial-derived microparticles.

  12. A novel role for inhibitor of apoptosis (IAP) proteins as regulators of endothelial barrier function by mediating RhoA activation.

    Science.gov (United States)

    Hornburger, Michael C; Mayer, Bettina A; Leonhardt, Stefanie; Willer, Elisabeth A; Zahler, Stefan; Beyerle, Andrea; Rajalingam, Krishnaraj; Vollmar, Angelika M; Fürst, Robert

    2014-04-01

    Inhibitor of apoptosis (IAP) proteins, such as XIAP or cIAP1/2, are important regulators of apoptosis in cancer cells, and IAP antagonists are currently evaluated as antitumor agents. Beyond their function in cancer cells, this study demonstrates a novel role of IAPs as regulators of vascular endothelial permeability. Two structurally different IAP antagonists, ABT and Smac085, as well as silencing of IAPs, reduced the thrombin receptor-activating peptide (TRAP)-induced barrier dysfunction in human endothelial cells as assessed by measuring macromolecular permeability or transendothelial electrical resistance. ABT diminished thrombin-evoked stress fiber formation, activation of myosin light chain 2, and disassembly of adherens junctions independent of calcium signaling, protein kinase C, and mitogen-activated protein kinases. Interestingly, ABT and silencing of IAPs, in particular XIAP, reduced the TRAP-evoked RhoA activation, whereas Rac1 was not affected. XIAP and, to a lesser extent, cIAP1 were found to directly interact with RhoA independently of the RhoA activation status. Under cell-free conditions, XIAP did not induce an ubiquitination of RhoA. In summary, our work discloses IAPs as crucial regulators of endothelial permeability and suggests IAP inhibition as interesting approach for the prevention of endothelial barrier dysfunction.

  13. Basal and Activated Calcium Sensitization Mediated by RhoA/Rho Kinase Pathway in Rats with Genetic and Salt Hypertension

    Czech Academy of Sciences Publication Activity Database

    Behuliak, Michal; Bencze, Michal; Vaněčková, Ivana; Kuneš, Jaroslav; Zicha, Josef

    2017-01-01

    Roč. 2017, January (2017), č. článku 8029728. ISSN 2314-6133 R&D Projects: GA ČR(CZ) GP14-16225P; GA MZd(CZ) NV15-25396A Institutional support: RVO:67985823 Keywords : calcium sensitization * RhoA/Rho kinase * fasudil * calcium influx * nifedipine * BAY K8644 Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery OBOR OECD: Cardiac and Cardiovascular systems Impact factor: 2.476, year: 2016

  14. Inhibitory effect of rhynchophylline on contraction of cerebral arterioles to endothelin 1: role of rho kinase.

    Science.gov (United States)

    Hao, Hui-Feng; Liu, Li-Mei; Liu, Yu-Ying; Liu, Juan; Yan, Li; Pan, Chun-Shui; Wang, Ming-Xia; Wang, Chuan-She; Fan, Jing-Yu; Gao, Yuan-Sheng; Han, Jing-Yan

    2014-08-08

    Rhynchophylline (Rhy) is a major ingredient of Uncaria rhynchophylla (UR) used to reduce blood pressure and ameliorate brain ailments. This study was to examine the role of Rho kinase (ROCK) in the inhibition of Rhy on contraction of cerebral arterioles caused by endothelin 1 (ET-1). Cerebral arterioles of male Wistar rats were constricted with ET-1 for 10 min followed by perfusion of Rhy for 20 min. Changes in the diameters of the arterioles were recorded. The effects of Rhy on contraction of middle cerebral arteries (MCAs) were determined by a Multi-Myograph. Western blotting and immunofluorescent staining were used to examine the effects of Rhy on RhoA translocation and myosin phosphatase target subunit 1 (MYPT1) phosphorylation. In vivo, Rhy (30-300 µM) relaxed cerebral arterioles constricted with ET-1 dose-dependently. In vitro, Rhy at lower concentrations (1-100 µM) caused relaxation of rat MCAs constricted with KCl and Bay-K8644 (an agonist of L-type voltage-dependent calcium channels (L-VDCCs)). Rhy at higher concentrations (>100 µM) caused relaxation of rat MCAs constricted with ET-1, which was inhibited by Y27632, a ROCK׳s inhibitor. Western blotting of rat aortas showed that Rhy inhibited RhoA translocation and MYPT1 phosphorylation. Immunofluorescent staining of MCAs confirmed that phosphorylation of MYPT1 caused by ET-1 was inhibited by Rhy. These results demonstrate that Rhy is a potent inhibitor of contraction of cerebral arteries caused by ET-1 in vivo and in vitro. The effect of Rhy was in part mediated by inhibiting RhoA-ROCK signaling. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  15. Crucial role of rho-kinase in pressure overload-induced right ventricular hypertrophy and dysfunction in mice.

    Science.gov (United States)

    Ikeda, Shohei; Satoh, Kimio; Kikuchi, Nobuhiro; Miyata, Satoshi; Suzuki, Kota; Omura, Junichi; Shimizu, Toru; Kobayashi, Kenta; Kobayashi, Kazuto; Fukumoto, Yoshihiro; Sakata, Yasuhiko; Shimokawa, Hiroaki

    2014-06-01

    Right ventricular (RV) failure is the leading cause of death in various cardiopulmonary diseases, including pulmonary hypertension. It is generally considered that the RV is vulnerable to pressure overload as compared with the left ventricle (LV). However, as compared with LV failure, the molecular mechanisms of RV failure are poorly understood, and hence therapeutic targets of the disorder remain to be elucidated. Thus, we aimed to identify molecular therapeutic targets for RV failure in a mouse model of pressure overload. To induce pressure overload to respective ventricles, we performed pulmonary artery constriction or transverse aortic constriction in mice. We first performed microarray analysis and found that the molecules related to RhoA/Rho-kinase and integrin pathways were significantly upregulated in the RV with pulmonary artery constriction compared with the LV with transverse aortic constriction. Then, we examined the responses of both ventricles to chronic pressure overload in vivo. We demonstrated that compared with transverse aortic constriction, pulmonary artery constriction caused greater extents of mortality, Rho-kinase expression (especially ROCK2 isoform), and oxidative stress in pressure-overloaded RV, reflecting the weakness of the RV in response to pressure overload. Furthermore, mice with myocardial-specific overexpression of dominant-negative Rho-kinase showed resistance to pressure overload-induced hypertrophy and dysfunction associated with reduced oxidative stress. Finally, dominant-negative Rho-kinase mice showed a significantly improved long-term survival in both pulmonary artery constriction and transverse aortic constriction as compared with littermate controls. These results indicate that the Rho-kinase pathway plays a crucial role in RV hypertrophy and dysfunction, suggesting that the pathway is a novel therapeutic target of RV failure in humans. © 2014 American Heart Association, Inc.

  16. Plant Rho-type (Rop) GTPase-dependent activation of receptor-like cytoplasmic kinases in vitro.

    Science.gov (United States)

    Dorjgotov, Dulguun; Jurca, Manuela E; Fodor-Dunai, Csilla; Szucs, Attila; Otvös, Krisztina; Klement, Eva; Bíró, Judit; Fehér, Attila

    2009-04-02

    Plants have evolved distinct mechanisms to link Rho-type (Rop) GTPases to downstream signaling pathways as compared to other eukaryotes. Here, experimental data are provided that members of the Medicago, as well as Arabidopsis, receptor-like cytoplasmic kinase family (RLCK Class VI) were strongly and specifically activated by GTP-bound Rop GTPases in vitro. Deletion analysis indicated that the residues implicated in the interaction might be distributed on various parts of the kinases. Using a chimaeric Rop GTPase protein, the importance of the Rho-insert region in kinase activation could also be verified. These data strengthen the possibility that RLCKs may serve as Rop GTPase effectors in planta.

  17. Inhibition of Rho-associated kinases disturbs the collective cell migration of stratified TE-10 cells

    Directory of Open Access Journals (Sweden)

    Taro Mikami

    2015-01-01

    Full Text Available BACKGROUND: The collective cell migration of stratified epithelial cells is considered to be an important phenomenon in wound healing, development, and cancer invasion; however, little is known about the mechanisms involved. Furthermore, whereas Rho family proteins, including RhoA, play important roles in cell migration, the exact role of Rho-associated coiled coil-containing protein kinases (ROCKs in cell migration is controversial and might be cell-type dependent. Here, we report the development of a novel modified scratch assay that was used to observe the collective cell migration of stratified TE-10 cells derived from a human esophageal cancer specimen. RESULTS: Desmosomes were found between the TE-10 cells and microvilli of the surface of the cell sheet. The leading edge of cells in the cell sheet formed a simple layer and moved forward regularly; these rows were followed by the stratified epithelium. ROCK inhibitors and ROCK small interfering RNAs (siRNAs disturbed not only the collective migration of the leading edge of this cell sheet, but also the stratified layer in the rear. In contrast, RhoA siRNA treatment resulted in more rapid migration of the leading rows and disturbed movement of the stratified portion. CONCLUSIONS: The data presented in this study suggest that ROCKs play an important role in mediating the collective migration of TE-10 cell sheets. In addition, differences between the effects of siRNAs targeting either RhoA or ROCKs suggested that distinct mechanisms regulate the collective cell migration in the simple epithelium of the wound edge versus the stratified layer of the epithelium.

  18. Effect of electroacupuncture on the mRNA and protein expression of Rho-A and Rho-associated kinase II in spinal cord injury rats

    Directory of Open Access Journals (Sweden)

    You-jiang Min

    2017-01-01

    Full Text Available Electroacupuncture is beneficial for the recovery of spinal cord injury, but the underlying mechanism is unclear. The Rho/Rho-associated kinase (ROCK signaling pathway regulates the actin cytoskeleton by controlling the adhesive and migratory behaviors of cells that could inhibit neurite regrowth after neural injury and consequently hinder the recovery from spinal cord injury. Therefore, we hypothesized electroacupuncture could affect the Rho/ROCK signaling pathway to promote the recovery of spinal cord injury. In our experiments, the spinal cord injury in adult Sprague-Dawley rats was caused by an impact device. Those rats were subjected to electroacupuncture at Yaoyangguan (GV3, Dazhui (GV14, Zusanli (ST36 and Ciliao (BL32 and/or monosialoganglioside treatment. Behavioral scores revealed that the hindlimb motor functions improved with those treatments. Real-time quantitative polymerase chain reaction, fluorescence in situ hybridization and western blot assay showed that electroacupuncture suppressed the mRNA and protein expression of Rho-A and Rho-associated kinase II (ROCKII of injured spinal cord. Although monosialoganglioside promoted the recovery of hindlimb motor function, monosialoganglioside did not affect the expression of Rho-A and ROCKII. However, electroacupuncture combined with monosialoganglioside did not further improve the motor function or suppress the expression of Rho-A and ROCKII. Our data suggested that the electroacupuncture could specifically inhibit the activation of the Rho/ROCK signaling pathway thus partially contributing to the repair of injured spinal cord. Monosialoganglioside could promote the motor function but did not suppress expression of RhoA and ROCKII. There was no synergistic effect of electroacupuncture combined with monosialoganglioside.

  19. Inhibition of Rho Kinase Induces Antioxidative Molecules and Suppresses Reactive Oxidative Species in Trabecular Meshwork Cells

    Directory of Open Access Journals (Sweden)

    Tomokazu Fujimoto

    2017-01-01

    Full Text Available Purpose. To investigate the effect of rho kinase inhibitors on oxidative stress in trabecular meshwork (TM cells. Methods. TM cells were isolated from the eyes of cynomolgus monkeys. Y-27632 and menadione were used to inhibit rho kinase and induce production of reactive oxygen species (ROS, respectively. The cynomolgus monkey array and 12,613 probes were used in DNA microarray analysis, and the affected genes were categorized using gene ontology analysis. The mRNA levels of the target genes were confirmed by real-time RT-PCR. Intracellular oxidative stress was detected using a fluorescent reagent sensitive to ROS. Cell viability was assessed by the WST-8 assay. Results. Gene ontology analysis revealed upregulation of genes involved in antioxidant activity, and upregulation of catalase was confirmed by real-time RT-PCR after 30 min treatment with Y-27632. Production of ROS was increased by menadione, and the effect was partly suppressed by pretreatment with Y-27632. At a lower dose of menadione, Y-27632 stimulated TM cells and significantly increased their viability following menadione treatment compared to control cells. Conclusion. Using microarray analysis, Y-27632 was shown to upregulate antioxidative genes including catalase and partially reduce ROS production and cell death by oxidative stress caused by menadione.

  20. RhoG regulates anoikis through a phosphatidylinositol 3-kinase-dependent mechanism

    International Nuclear Information System (INIS)

    Yamaki, Nao; Negishi, Manabu; Katoh, Hironori

    2007-01-01

    In normal epithelial cells, cell-matrix interaction is required for cell survival and proliferation, whereas disruption of this interaction causes epithelial cells to undergo apoptosis called anoikis. Here we show that the small GTPase RhoG plays an important role in the regulation of anoikis. HeLa cells are capable of anchorage-independent cell growth and acquire resistance to anoikis. We found that RNA interference-mediated knockdown of RhoG promoted anoikis in HeLa cells. Previous studies have shown that RhoG activates Rac1 and induces several cellular functions including promotion of cell migration through its effector ELMO and the ELMO-binding protein Dock180 that function as a Rac-specific guanine nucleotide exchange factor. However, RhoG-induced suppression of anoikis was independent of the ELMO- and Dock180-mediated activation of Rac1. On the other hand, the regulation of anoikis by RhoG required phosphatidylinositol 3-kinase (PI3K) activity, and constitutively active RhoG bound to the PI3K regulatory subunit p85α and induced the PI3K-dependent phosphorylation of Akt. Taken together, these results suggest that RhoG protects cells from apoptosis caused by the loss of anchorage through a PI3K-dependent mechanism, independent of its activation of Rac1

  1. TrkB-T1 regulates the RhoA signaling and actin cytoskeleton in glioma cells

    International Nuclear Information System (INIS)

    Ohira, Koji; Homma, Koichi J.; Hirai, Hirohisa; Nakamura, Shun; Hayashi, Motoharu

    2006-01-01

    Recently, the truncated TrkB receptor, T1, has been reported to be involved in the control of cell morphology via the regulation of Rho proteins, through which T1 binds Rho guanine nucleotide dissociation inhibitor (Rho GDI) 1 and dissociates it in a brain-derived neurotrophic factor (BDNF)-dependent manner. However, it is unclear whether T1 signaling regulates the downstream of Rho signaling and the actin cytoskeleton. In this study, we investigated this question using C6 rat glioma cells, which express T1 endogenously. Rho GDI1 was dissociated from T1 in a BDNF-dependent manner, which also causes decreases in the activities of Rho-signaling molecules such as RhoA, Rho-associated kinase, p21-activated kinase, and extracellular-signal regulated kinase1/2. Moreover, BDNF treatment resulted in the disappearance of stress fibers in the cells treated with lysophosphatidic acid, an activator of RhoA, and in morphological changes in cells. Furthermore, a competitive assay with cyan fluorescent protein fusion proteins of T1-specific sequences reduced the effects of BDNF. These results suggest that T1 regulates the Rho-signaling pathways and the actin cytoskeleton

  2. Phosphorylation and mRNA splicing of collapsin response mediator protein-2 determine inhibition of rho-associated protein kinase (ROCK) II function in carcinoma cell migration and invasion

    DEFF Research Database (Denmark)

    Morgan-Fisher, Marie; Couchman, John R; Yoneda, Atsuko

    2013-01-01

    The Rho-associated protein kinases (ROCK I and II) are central regulators of important cellular processes such as migration and invasion downstream of the GTP-Rho. Recently, we reported collapsin response mediator protein (CRMP)-2 as an endogenous ROCK II inhibitor. To reveal how the CRMP-2-ROCK II......, the presented data show that CRMP-2-dependent regulation of ROCK II activity is mediated through interaction of the CRMP-2L N terminus with the ROCK II catalytic domain as well as by GSK3-dependent phosphorylation of CRMP-2....

  3. Liposomal Fasudil, a Rho-Kinase Inhibitor, for Prolonged Pulmonary Preferential Vasodilation in Pulmonary Arterial Hypertension

    Science.gov (United States)

    Gupta, Vivek; Gupta, Nilesh; Shaik, Imam H.; Mehvar, Reza; McMurtry, Ivan F.; Oka, Masahiko; Nozik-Grayck, Eva; Komatsu, Masanobu; Ahsan, Fakhrul

    2013-01-01

    Current pharmacological interventions for pulmonary arterial hypertension (PAH) require continuous infusions, multiple inhalations, or oral administration of drugs that act on various pathways involved in the pathogenesis of PAH. However, invasive methods of administration, short duration of action, and lack of pulmonary selectivity result in noncompliance and poor patient outcomes. In this study, we tested the hypothesis that encapsulation of an investigational anti-PAH molecule fasudil (HA-1077), a Rho-kinase inhibitor, into liposomal vesicles results in prolonged vasodilation in distal pulmonary arterioles. Liposomes were prepared by hydration and extrusion method and fasudil was loaded by ammonium sulfate-induced transmembrane electrochemical gradient. Liposomes were then characterized for various physicochemical properties. Optimized formulations were tested for pulmonary absorption and their pharmacological efficacy in a monocrotaline (MCT) induced rat model of PAH. The entrapment efficiency of optimized liposomal fasudil formulations was between 68.1±0.8% and 73.6±2.3%, and the cumulative release at 37°C was 98–99% over a period of 5 days. Compared to intravenous (IV) fasudil, a ~10 fold increase in the terminal plasma half-life was observed when liposomal fasudil was administered as aerosols. The t1/2 of IV fasudil was 0.39±0.12 h. and when given as liposomes via pulmonary route, the t1/2 extended to 4.71±0.72 h. One h after intratracheal instillation of liposomal fasudil, mean pulmonary arterial pressure (MPAP) was reduced by 37.6±5.7% and continued to decrease for about 3 h, suggesting that liposomal formulations produced pulmonary preferential vasodilation in MCT induced PAH rats. Overall, this study established the proof-of-principle that aerosolized liposomal fasudil is a feasible option for a non-invasive, controlled release and pulmonary preferential treatment of PAH. PMID:23353807

  4. Identification and Structure-Function Analysis of Subfamily Selective G Protein-Coupled Receptor Kinase Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Homan, Kristoff T.; Larimore, Kelly M.; Elkins, Jonathan M.; Szklarz, Marta; Knapp, Stefan; Tesmer, John J.G. [Michigan; (Oxford)

    2015-02-13

    Selective inhibitors of individual subfamilies of G protein-coupled receptor kinases (GRKs) would serve as useful chemical probes as well as leads for therapeutic applications ranging from heart failure to Parkinson’s disease. To identify such inhibitors, differential scanning fluorimetry was used to screen a collection of known protein kinase inhibitors that could increase the melting points of the two most ubiquitously expressed GRKs: GRK2 and GRK5. Enzymatic assays on 14 of the most stabilizing hits revealed that three exhibit nanomolar potency of inhibition for individual GRKs, some of which exhibiting orders of magnitude selectivity. Most of the identified compounds can be clustered into two chemical classes: indazole/dihydropyrimidine-containing compounds that are selective for GRK2 and pyrrolopyrimidine-containing compounds that potently inhibit GRK1 and GRK5 but with more modest selectivity. The two most potent inhibitors representing each class, GSK180736A and GSK2163632A, were cocrystallized with GRK2 and GRK1, and their atomic structures were determined to 2.6 and 1.85 Å spacings, respectively. GSK180736A, developed as a Rho-associated, coiled-coil-containing protein kinase inhibitor, binds to GRK2 in a manner analogous to that of paroxetine, whereas GSK2163632A, developed as an insulin-like growth factor 1 receptor inhibitor, occupies a novel region of the GRK active site cleft that could likely be exploited to achieve more selectivity. However, neither compound inhibits GRKs more potently than their initial targets. This data provides the foundation for future efforts to rationally design even more potent and selective GRK inhibitors.

  5. Opportunities to Target Specific Contractile Abnormalities with Smooth Muscle Protein Kinase Inhibitors

    Directory of Open Access Journals (Sweden)

    Annegret Ulke-Lemée

    2010-05-01

    Full Text Available Smooth muscle is a major component of most hollow organ systems (e.g., airways, vasculature, bladder and gut/gastrointestine; therefore, the coordinated regulation of contraction is a key property of smooth muscle. When smooth muscle functions normally, it contributes to general health and wellness, but its dysfunction is associated with morbidity and mortality. Rho-associated protein kinase (ROCK is central to calcium-independent, actomyosin-mediated contractile force generation in the vasculature, thereby playing a role in smooth muscle contraction, cell motility and adhesion. Recent evidence supports an important role for ROCK in the increased vasoconstriction and remodeling observed in various models of hypertension. This review will provide a commentary on the development of specific ROCK inhibitors and their clinical application. Fasudil will be discussed as an example of bench-to-bedside development of a clinical therapeutic that is used to treat conditions of vascular hypercontractility. Due to the wide spectrum of biological processes regulated by ROCK, many additional clinical indications might also benefit from ROCK inhibition. Apart from the importance of ROCK in smooth muscle contraction, a variety of other protein kinases are known to play similar roles in regulating contractile force. The zipper-interacting protein kinase (ZIPK and integrin-linked kinase (ILK are two well-described regulators of contraction. The relative contribution of each kinase to contraction depends on the muscle bed as well as hormonal and neuronal stimulation. Unfortunately, specific inhibitors for ZIPK and ILK are still in the development phase, but the success of fasudil suggests that inhibitors for these other kinases may also have valuable clinical applications. Notably, the directed inhibition of ZIPK with a pseudosubstrate molecule shows unexpected effects on the contractility of gastrointestinal smooth muscle.

  6. Effect of Rho kinase inhibitor fasudil on the expression ET-1 and NO in rats with hypoxic pulmonary hypertension.

    Science.gov (United States)

    Sun, Xing-Zhen; Li, Shu-Yan; Tian, Xiang-Yang; Hong, Ze; Li, Jia-Xin

    2018-04-12

    This study aims to study the effect of Rho kinase inhibitor fasudil on the expression endothelin-1 (ET-1) and nitric oxide (NO) in rats with hypoxic pulmonary hypertension (HPH). Twenty-four male SD rats were randomly divided into three groups: control group, model group (HPH group) and HPH+fasudil group. The rat HPH model was established by intermittent hypoxia (IH) at atmospheric pressure. Mean pulmonary artery pressure (mPAP), right ventricular hypertrophy index (RVHI), ET-1 and NO levels, and pulmonary vascular structural changes were observed in all groups. MPAP, RVHI and ET-1 levels were significantly higher in HPH group than in control group, while NO was significantly lower than in control group. In addition, mPAP, RVHI and ET-1 were significantly lower in the HPH+fasudil group than in the HPH group. In the HPH group, ET-1 level was significantly and positively correlated with mPAP and RVHI, NO was negatively correlated with mPAP and RVHI levels, and ET-1 level was significantly and negatively correlated with NO level. In the HPH group, pulmonary arteriolar walls were generally thickened, and lumen stenosis was obvious; while after fasudil treatment, pulmonary arteriolar wall thickening and stenosis degree were significantly reduced. Fasudil can significantly reduce ET-l level and increase NO level in HPH rats, suppressing the development of pulmonary arterial hypertension.

  7. Distinctive G Protein-Dependent Signaling by Protease-Activated Receptor 2 (PAR2 in Smooth Muscle: Feedback Inhibition of RhoA by cAMP-Independent PKA.

    Directory of Open Access Journals (Sweden)

    Wimolpak Sriwai

    Full Text Available We examined expression of protease-activated receptors 2 (PAR2 and characterized their signaling pathways in rabbit gastric muscle cells. The PAR2 activating peptide SLIGRL (PAR2-AP stimulated Gq, G13, Gi1, PI hydrolysis, and Rho kinase activity, and inhibited cAMP formation. Stimulation of PI hydrolysis was partly inhibited in cells expressing PAR2 siRNA, Gaq or Gai minigene and in cells treated with pertussis toxin, and augmented by expression of dominant negative regulator of G protein signaling (RGS4(N88S. Stimulation of Rho kinase activity was abolished by PAR-2 or Ga13 siRNA, and by Ga13 minigene. PAR2-AP induced a biphasic contraction; initial contraction was selectively blocked by the inhibitor of PI hydrolysis (U73122 or MLC kinase (ML-9, whereas sustained contraction was selectively blocked by the Rho kinase inhibitor (Y27632. PAR2-AP induced phosphorylation of MLC20, MYPT1 but not CPI-17. PAR2-AP also caused a decrease in the association of NF-kB and PKA catalytic subunit: the effect of PAR2-AP was blocked by PAR2 siRNA or phosphorylation-deficient RhoA (RhoA(S188A. PAR2-AP-induced degradation of IkBa and activation of NF-kB were abolished by the blockade of RhoA activity by Clostridium botulinum C3 exoenzyme suggesting RhoA-dependent activation of NF-kB. PAR2-AP-stimulated Rho kinase activity was significantly augmented by the inhibitors of PKA (myristoylated PKI, IKK2 (IKKIV or NF-kB (MG132, and in cells expressing dominant negative mutants of IKK (IKK(K44A, IkBa (IkBa (S32A/S36A or RhoA(S188A, suggesting feedback inhibition of Rho kinase activity via PKA derived from NF-kB pathway. PAR2-AP induced phosphorylation of RhoA and the phosphorylation was attenuated in cells expressing phosphorylation-deficient RhoA(S188A. Our results identified signaling pathways activated by PAR2 to mediate smooth muscle contraction and a novel pathway for feedback inhibition of PAR2-stimulated RhoA. The pathway involves activation of the NF-kB to

  8. Inhibition of Rho kinase regulates specification of early differentiation events in P19 embryonal carcinoma stem cells.

    Directory of Open Access Journals (Sweden)

    Roman J Krawetz

    Full Text Available The Rho kinase pathway plays a key role in many early cell/tissue determination events that take place in embryogenesis. Rho and its downstream effector Rho kinase (ROCK play pivotal roles in cell migration, apoptosis (membrane blebbing, cell proliferation/cell cycle, cell-cell adhesion and gene regulation. We and others have previously demonstrated that inhibition of ROCK blocks endoderm differentiation in embryonal carcinoma stem cells, however, the effect of ROCK inhibition on mesoderm and ectoderm specification has not been fully examined. In this study, the role of ROCK within the specification and differentiation of all three germ layers was examined.P19 cells were treated with the specific ROCK inhibitor Y-27623, and increase in differentiation efficiency into neuro-ectodermal and mesodermal lineages was observed. However, as expected a dramatic decrease in early endodermal markers was observed when ROCK was inhibited. Interestingly, within these ROCK-inhibited RA treated cultures, increased levels of mesodermal or ectodermal markers were not observed, instead it was found that the pluripotent markers SSEA-1 and Oct-4 remained up-regulated similar to that seen in undifferentiated cultures. Using standard and widely accepted methods for reproducible P19 differentiation into all three germ layers, an enhancement of mesoderm and ectoderm differentiation with a concurrent loss of endoderm lineage specification was observed with Y-27632 treatment. Evidence would suggest that this effect is in part mediated through TGF-β and SMAD signaling as ROCK-inhibited cells displayed aberrant SMAD activation and did not return to a 'ground' state after the inhibition had been removed.Given this data and the fact that only a partial rescue of normal differentiation capacity occurred when ROCK inhibition was alleviated, the effect of ROCK inhibition on the differentiation capacity of pluripotent cell populations should be further examined to elucidate the

  9. Tyrosine kinase inhibitors: Multi-targeted or single-targeted?

    Science.gov (United States)

    Broekman, Fleur; Giovannetti, Elisa; Peters, Godefridus J

    2011-02-10

    Since in most tumors multiple signaling pathways are involved, many of the inhibitors in clinical development are designed to affect a wide range of targeted kinases. The most important tyrosine kinase families in the development of tyrosine kinase inhibitors are the ABL, SCR, platelet derived growth factor, vascular endothelial growth factor receptor and epidermal growth factor receptor families. Both multi-kinase inhibitors and single-kinase inhibitors have advantages and disadvantages, which are related to potential resistance mechanisms, pharmacokinetics, selectivity and tumor environment. In different malignancies various tyrosine kinases are mutated or overexpressed and several resistance mechanisms exist. Pharmacokinetics is influenced by interindividual differences and differs for two single targeted inhibitors or between patients treated by the same tyrosine kinase inhibitor. Different tyrosine kinase inhibitors have various mechanisms to achieve selectivity, while differences in gene expression exist between tumor and stromal cells. Considering these aspects, one type of inhibitor can generally not be preferred above the other, but will depend on the specific genetic constitution of the patient and the tumor, allowing personalized therapy. The most effective way of cancer treatment by using tyrosine kinase inhibitors is to consider each patient/tumor individually and to determine the strategy that specifically targets the consequences of altered (epi)genetics of the tumor. This strategy might result in treatment by a single multi kinase inhibitor for one patient, but in treatment by a couple of single kinase inhibitors for other patients.

  10. Behavioural effects of basal ganglia rho-kinase inhibition in the unilateral 6-hydroxydopamine rat model of Parkinson's disease.

    Science.gov (United States)

    Inan, Salim Yalcin; Soner, Burak Cem; Sahin, Ayse Saide

    2016-08-01

    Parkinson's disease (PD) is one of the most common neurodegenerative disorders, which affects more than six million people in the world. While current available pharmacological therapies for PD in the early stages of the disease usually improve motor symptoms, they cause side effects, such as fluctuations and dyskinesias in the later stages. In this later stage, high frequency deep brain stimulation of the subthalamic nucleus (STN-DBS) is a treatment option which is most successful to treat drug resistant advanced PD. It has previously been demonstrated that activation of Rho/Rho-kinase pathway is involved in the dopaminergic cell degeneration which is one of the main characteristics of PD pathology. In addition, the involvement of this pathway has been suggested in diverse cellular events in the central nervous system; such as epilepsy, anxiety-related behaviors, regulation of dendritic and axonal morphology, antinociception, subarachnoid haemorrhage, spinal cord injury and amyotrophic lateral sclerosis. However, up to date, to our knowledge there are no previous reports showing the beneficial effects of the potent Rho-kinase inhibitor Y-27632 in the 6-hydroxydopamine (6-OHDA) rat model of PD. Therefore, in the present study, we investigated the behavioural effects of basal ganglia Y-27632 microinjections in this PD model. Our results indicated that basal ganglia Y-27632 microinjections significantly decreased the number of contralateral rotations-induced by apomorphine, significantly increased line crossings in the open-field test, contralateral forelimb use in the limb-use asymmetry test and contralateral tape playing time in the somatosensory asymmetry test, which may suggest that Y-27632 could be a potentially active antiparkinsonian agent.

  11. Novel ROCK inhibitors for the treatment of pulmonary arterial hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Duncan; Hollingworth, Greg; Soldermann, Nicolas; Sprague, Elizabeth; Schuler, Walter; Vangrevelinghe, Eric; Duggan, Nicholas; Thomas, Matthew; Kosaka, Takatoshi; Waters, Nigel; van Eis, Maurice J. (Novartis)

    2014-10-01

    A novel class of selective inhibitors of ROCK1 and ROCK2 has been identified by structural based drug design. PK/PD experiments using a set of highly selective Rho kinase inhibitors suggest that systemic Rho kinase inhibition is linked to a reversible reduction in lymphocyte counts. These results led to the consideration of topical delivery of these molecules, and to the identification of a lead molecule 7 which shows promising PK and PD in a murine model of pulmonary hypertension after intra-tracheal dosing.

  12. RhoA/Rho kinase signaling regulates transforming growth factor-β1-induced chondrogenesis and actin organization of synovium-derived mesenchymal stem cells through interaction with the Smad pathway.

    Science.gov (United States)

    Xu, Ting; Wu, Mengjie; Feng, Jianying; Lin, Xinping; Gu, Zhiyuan

    2012-11-01

    Recent studies have suggested that synovium-derived mesenchymal stem cells (SMSCs) may be promising candidates for tissue engineering and play an important role in cartilage regeneration. However, the mechanisms of SMSC chondrogenesis remain to be identified and characterized. The aim of this study was to evaluate the activation of the RhoA/Rho kinase (ROCK) pathway, as well as the manner by which it may contribute to chondrogenesis and the actin cytoskeletal organization of rat temporomandibular SMSCs in response to transforming growth factor-β1 (TGF-β1). Primary isolated SMSCs were treated with TGF-β1, and their actin organization was examined by fluorescein isothiocyanate-phalloidin staining. The specific biochemical inhibitors, C3 transferase, Y27632 and SB431542, were employed to evaluate the function of RhoA/ROCK and Smads. The effect of C3 transferase and Y27632 on the gene expression of chondrocyte-specific markers was evaluated by quantitative real-time polymerase chain reaction. To examine the effect of Y27632 on Smad2/3 phosphorylation induced by TGF-β1, western blot analysis was also performed. The stimulation of TGF-β1 in SMSCs resulted in the activation of the RhoA/ROCK pathway and concomitantly induced cytoskeletal reorganization, which was specifically blocked by C3 transferase and Y27632. The TGF-β-induced gene expression of Sox9, type I collagen, type II collagen and aggrecan was also inhibited by both C3 transferase and Y27632, at different levels. Y27632 treatment reduced the phosphorylation of Smad2/3 in a concentration-dependent manner. These results demonstrate the RhoA/ROCK activation regulates chondrocyte-specific gene transcription and cytoskeletal organization induced by TGF-β1 by interacting with the Smad pathway. This may have significant implications for the successful utilization of SMSCs as a cell source for articular cartilage tissue engineering.

  13. The Rac-RhoGDI complex and the structural basis for the regulation of Rho proteins by RhoGDI

    DEFF Research Database (Denmark)

    Scheffzek, K; Stephan, I; Jensen, Ole Nørregaard

    2000-01-01

    Rho family-specific guanine nucleotide dissociation inhibitors (RhoGDIs) decrease the rate of nucleotide dissociation and release Rho proteins such as RhoA, Rac and Cdc42 from membranes, forming tight complexes that shuttle between cytosol and membrane compartments. We have solved the crystal...

  14. Rho Kinase (ROCK) collaborates with Pak to Regulate Actin Polymerization and Contraction in Airway Smooth Muscle.

    Science.gov (United States)

    Zhang, Wenwu; Bhetwal, Bhupal P; Gunst, Susan J

    2018-05-10

    The mechanisms by which Rho kinase (ROCK) regulates airway smooth muscle contraction were determined in tracheal smooth muscle tissues. ROCK may mediate smooth muscle contraction by inhibiting myosin regulatory light chain (RLC) phosphatase. ROCK can also regulate F-actin dynamics during cell migration, and actin polymerization is critical for airway smooth muscle contraction. Our results show that ROCK does not regulate airway smooth muscle contraction by inhibiting myosin RLC phosphatase or by stimulating myosin RLC phosphorylation. We find that ROCK regulates airway smooth muscle contraction by activating the serine-threonine kinase Pak, which mediates the activation of Cdc42 and Neuronal-Wiskott-Aldrich Syndrome protein (N-WASp). N-WASP transmits signals from cdc42 to the Arp2/3 complex for the nucleation of actin filaments. These results demonstrate a novel molecular function for ROCK in the regulation of Pak and cdc42 activation that is critical for the processes of actin polymerization and contractility in airway smooth muscle. Rho kinase (ROCK), a RhoA GTPase effector, can regulate the contraction of airway and other smooth muscle tissues. In some tissues, ROCK can inhibit myosin regulatory light chain (RLC) phosphatase, which increases the phosphorylation of myosin RLC and promotes smooth muscle contraction. ROCK can also regulate cell motility and migration by affecting F-actin dynamics. Actin polymerization is stimulated by contractile agonists in airway smooth muscle tissues and is required for contractile tension development in addition to myosin RLC phosphorylation. We investigated the mechanisms by which ROCK regulates the contractility of tracheal smooth muscle tissues by expressing a kinase inactive mutant of ROCK, ROCK-K121G, in the tissues or by treating them with the ROCK inhibitor, H-1152P. Our results show no role for ROCK in the regulation of non-muscle or smooth muscle myosin RLC phosphorylation during contractile stimulation in this tissue

  15. Diuretics prevent Rho-kinase activation and expression of profibrotic/oxidative genes in the hypertensive aortic wall.

    Science.gov (United States)

    Araos, Patricio; Mondaca, David; Jalil, Jorge E; Yañez, Cristián; Novoa, Ulises; Mora, Italo; Ocaranza, María Paz

    2016-12-01

    Diuretics are current antihypertensive drugs since they reduce blood pressure and cardiovascular risk. Increased vascular tone is modulated in a relevant way by the RhoA/Rho-kinase (ROCK) pathway, by acting on vascular smooth muscle cell contraction. This pathway has also proremodeling vascular effects. There are few data on the role of diuretics on both vascular ROCK activation and on proremodeling effects. We assessed the effects of hydrochlorothiazide (HCTZ) and spironolactone (spiro) alone and in combination with the ROCK inhibitor fasudil (FAS) on ROCK activation, gene expression of proremodeling markers and on hypertrophy in the aortic wall of hypertensive rats. Deoxycorticosterone acetate (DOCA)-salt hypertensive rats (male, Sprague-Dawley) were randomized to the specific ROCK inhibitor FAS, HCTZ, spiro or the combinations of FAS/HCTZ or FAS/spiro for 3 weeks. At the end of the study, ROCK activation (by western blot), gene expression of proremodeling markers (by reverse transcription polymerase chain reaction, RT-PCR) and vascular hypertrophy (by morphometry) were determined in the aortic wall. All treatments significantly reduced blood pressure. In the DOCA rats the p-myosin phosphatase target protein-1 (MYPT1)/t-MYPT1 ratio, index of ROCK activation was higher by 2.8 fold (p diuretics alone or in combination with FAS. In the aortic wall, both HCTZ and spiro in antihypertensive doses reduce ROCK activation, subsequent expression of genes that promote vascular remodeling and hypertrophy in this experimental model of hypertension. These effects could explain some of their clinical benefits in hypertensive patients. © The Author(s), 2016.

  16. A screen for kinase inhibitors identifies antimicrobial imidazopyridine aminofurazans as specific inhibitors of the Listeria monocytogenes PASTA kinase PrkA.

    Science.gov (United States)

    Schaenzer, Adam J; Wlodarchak, Nathan; Drewry, David H; Zuercher, William J; Rose, Warren E; Striker, Rob; Sauer, John-Demian

    2017-10-13

    Bacterial signaling systems such as protein kinases and quorum sensing have become increasingly attractive targets for the development of novel antimicrobial agents in a time of rising antibiotic resistance. The family of bacterial P enicillin-binding-protein A nd S erine/ T hreonine kinase- A ssociated (PASTA) kinases is of particular interest due to the role of these kinases in regulating resistance to β-lactam antibiotics. As such, small-molecule kinase inhibitors that target PASTA kinases may prove beneficial as treatments adjunctive to β-lactam therapy. Despite this interest, only limited progress has been made in identifying functional inhibitors of the PASTA kinases that have both activity against the intact microbe and high kinase specificity. Here, we report the results of a small-molecule screen that identified GSK690693, an imidazopyridine aminofurazan-type kinase inhibitor that increases the sensitivity of the intracellular pathogen Listeria monocytogenes to various β-lactams by inhibiting the PASTA kinase PrkA. GSK690693 potently inhibited PrkA kinase activity biochemically and exhibited significant selectivity for PrkA relative to the Staphylococcus aureus PASTA kinase Stk1. Furthermore, other imidazopyridine aminofurazans could effectively inhibit PrkA and potentiate β-lactam antibiotic activity to varying degrees. The presence of the 2-methyl-3-butyn-2-ol (alkynol) moiety was important for both biochemical and antimicrobial activity. Finally, mutagenesis studies demonstrated residues in the back pocket of the active site are important for GSK690693 selectivity. These data suggest that targeted screens can successfully identify PASTA kinase inhibitors with both biochemical and antimicrobial specificity. Moreover, the imidazopyridine aminofurazans represent a family of PASTA kinase inhibitors that have the potential to be optimized for selective PASTA kinase inhibition.

  17. Janus kinase inhibitors: jackpot or potluck?

    Directory of Open Access Journals (Sweden)

    Pavithran Keechilat

    2012-06-01

    Full Text Available The reports of a unique mutation in the Janus kinase-2 gene (JAK2 in polycythemia vera by several independent groups in 2005 quickly spurred the development of the Janus kinase inhibitors. In one of the great victories of translational research in recent times, the first smallmolecule Janus kinase inhibitor ruxolitinib entered a phase I trial in 2007. With the approval of ruxolitinib by the US Federal Drug Administration in November 2011 for high-risk and intermediate-2 risk myelofibrosis, a change in paradigm has occurred in the management of a subset of myeloproliferative neoplasms (MPN: primary myelofibrosis, post-polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis. Whereas the current evidence for ruxolitinib only covers high-risk and intermediate-2 risk myelofibrosis, inhibitors with greater potency are likely to offer better disease control and survival advantage in patients belonging to these categories, and possibly to the low-risk and intermediate-1 risk categories of MPN as well. But use of the Janus kinase inhibitors also probably has certain disadvantages, such as toxicity, resistance, withdrawal phenomenon, non-reversal of histology, and an implausible goal of disease clone eradication, some of which could offset the gains. In spite of this, Janus kinase inhibitors are here to stay, and for use in more than just myeloproliferative neoplasms.

  18. Allosteric small-molecule kinase inhibitors

    DEFF Research Database (Denmark)

    Wu, Peng; Clausen, Mads Hartvig; Nielsen, Thomas E.

    2015-01-01

    current barriers of kinase inhibitors, including poor selectivity and emergence of drug resistance. In spite of the small number of identified allosteric inhibitors in comparison with that of inhibitors targeting the ATP pocket, encouraging results, such as the FDA-approval of the first small...

  19. Janus Associated Kinases Inhibitors in the Pharmacological Thera

    Directory of Open Access Journals (Sweden)

    Daniela Santos1

    2017-01-01

    Full Text Available Janus associated kinases inhibitors are a new strategy for the treatment of different clinical conditions like immunologic, inflammatory and oncology disorders. The aim of this study was to perform a review of all Janus associated kinases inhibitors available in national and international pharmaceutical market, their therapeutic indications and adverse effects, and the potential indications for investigation of those already available in the pharmaceutical market. It was also performed a review of the main new Janus associated kinases inhibitors that are still in clinical research. A literature review was conducted by consulting the summary of product characteristics of Janus associated kinases inhibitors available in the pharmaceutical market and a research in the bibliographic database PubMed using the terms «JAK inhibitors», «Janus associated kinases inhibitors» and «Janus kinases inhibitors». Ninety-five publications were included in the present review, published from January 2014 to January 2015. Drug databases of the European Medicines Agency and United States Food and Drug Administration were also consulted to search for Janus associated kinases inhibitors authorized in clinical practice. Currently, ruxolitinib and tofacitinib are available in the pharmaceutical market and oclatinib is approved as a veterinary medicinal product. Both drugs approved for human use have major adverse effects at hematological and immunological levels, which enhance the importance of the pharmacist’s role in the monitoring of patients involved in these treatments. However, several molecules are in pre-clinical and clinical studies trying to prove its potential in the treatment of several immunologic, inflammatory and oncology disorders. Thus, it is still necessary to deepen the knowledge in this area in order to overcome the risks of therapy with these agents. These risks weighed against the benefits of its clinical use have compromised the progress of

  20. Rho-associated kinase in the gustatory cortex is involved in conditioned taste aversion memory formation but not in memory retrieval or relearning.

    Science.gov (United States)

    Sweetat, Sahar; Rosenblum, Kobi; Lamprecht, Raphael

    2012-01-01

    Rho-associated kinase (ROCK) is intimately involved in cortical neuronal morphogenesis. The present study explores the roles of ROCK in conditioned taste aversion (CTA) memory formation in gustatory cortex (GC) in adult rat. Microinjection of the ROCK inhibitor Y-27632 into the GC 30 min before CTA training or 10 min after the conditioned stimulus (CS) impaired long-term CTA memory (LTM) formation. ROCK inhibitor had no effect on taste aversion when injected before the first LTM test day and did not alter taste aversion on subsequent test days. Microinjection of ROCK inhibitor into GC 30 min before preexposure to the taste CS had no effect on latent inhibition of CTA learning suggesting that ROCK is involved in CS-US association rather than taste learning per se. Cumulatively, these results show that ROCK is needed for normal CTA memory formation but not retrieval, relearning or incidental taste learning. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. The Rho Kinases: Critical Mediators of Multiple Profibrotic Processes and Rational Targets for New Therapies for Pulmonary Fibrosis

    Science.gov (United States)

    Knipe, Rachel S.; Tager, Andrew M.

    2015-01-01

    Idiopathic pulmonary fibrosis (IPF) is characterized by progressive lung scarring, short median survival, and limited therapeutic options, creating great need for new pharmacologic therapies. IPF is thought to result from repetitive environmental injury to the lung epithelium, in the context of aberrant host wound healing responses. Tissue responses to injury fundamentally involve reorganization of the actin cytoskeleton of participating cells, including epithelial cells, fibroblasts, endothelial cells, and macrophages. Actin filament assembly and actomyosin contraction are directed by the Rho-associated coiled-coil forming protein kinase (ROCK) family of serine/threonine kinases (ROCK1 and ROCK2). As would therefore be expected, lung ROCK activation has been demonstrated in humans with IPF and in animal models of this disease. ROCK inhibitors can prevent fibrosis in these models, and more importantly, induce the regression of already established fibrosis. Here we review ROCK structure and function, upstream activators and downstream targets of ROCKs in pulmonary fibrosis, contributions of ROCKs to profibrotic cellular responses to lung injury, ROCK inhibitors and their efficacy in animal models of pulmonary fibrosis, and potential toxicities of ROCK inhibitors in humans, as well as involvement of ROCKs in fibrosis in other organs. As we discuss, ROCK activation is required for multiple profibrotic responses, in the lung and multiple other organs, suggesting ROCK participation in fundamental pathways that contribute to the pathogenesis of a broad array of fibrotic diseases. Multiple lines of evidence therefore indicate that ROCK inhibition has great potential to be a powerful therapeutic tool in the treatment of fibrosis, both in the lung and beyond. PMID:25395505

  2. The Rho GTPase Effector ROCK Regulates Cyclin A, Cyclin D1, and p27Kip1 Levels by Distinct Mechanisms

    OpenAIRE

    Croft, Daniel R.; Olson, Michael F.

    2006-01-01

    The members of the Rho GTPase family are well known for their regulation of actin cytoskeletal structures. In addition, they influence progression through the cell cycle. The RhoA and RhoC proteins regulate numerous effector proteins, with a central and vital signaling role mediated by the ROCK I and ROCK II serine/threonine kinases. The requirement for ROCK function in the proliferation of numerous cell types has been revealed by studies utilizing ROCK-selective inhibitors such as Y-27632. H...

  3. Rho kinase inhibition drives megakaryocyte polyploidization and proplatelet formation through MYC and NFE2 downregulation.

    Science.gov (United States)

    Avanzi, Mauro P; Goldberg, Francine; Davila, Jennifer; Langhi, Dante; Chiattone, Carlos; Mitchell, William Beau

    2014-03-01

    The processes of megakaryocyte polyploidization and demarcation membrane system (DMS) formation are crucial for platelet production, but the mechanisms controlling these processes are not fully determined. Inhibition of Rho kinase (ROCK) signalling leads to increased polyploidization in umbilical cord blood-derived megakaryocytes. To extend these findings we determined the effect of ROCK inhibition on development of the DMS and on proplatelet formation. The underlying mechanisms were explored by analysing the effect of ROCK inhibition on the expression of MYC and NFE2, which encode two transcription factors critical for megakaryocyte development. ROCK inhibition promoted DMS formation, and increased proplatelet formation and platelet release. Rho kinase inhibition also downregulated MYC and NFE2 expression in mature megakaryocytes, and this down-regulation correlated with increased proplatelet formation. Our findings suggest a model whereby ROCK inhibition drives polyploidization, DMS growth and proplatelet formation late in megakaryocyte maturation through downregulation of MYC and NFE2 expression. © 2014 John Wiley & Sons Ltd.

  4. The 'retro-design' concept for novel kinase inhibitors.

    Science.gov (United States)

    Müller, Gerhard; Sennhenn, Peter C; Woodcock, Timothy; Neumann, Lars

    2010-07-01

    Protein kinases are among the most attractive therapeutic targets for a broad range of diseases. This feature review highlights and classifies the main design principles employed to generate active and selective kinase inhibitors. In particular, emphasis is focused on a fragment-based lead-generation approach, which constitutes a novel design method for developing type II kinase inhibitors with distinct binding kinetic attributes. This 'retro-design' strategy relies on a customized fragment library, and contrasts the traditional approach used in the design of type II inhibitors.

  5. RhoA, Rho kinase, JAK2, and STAT3 may be the intracellular determinants of longevity implicated in the progeric influence of obesity: Insulin, IGF-1, and leptin may all conspire to promote stem cell exhaustion.

    Science.gov (United States)

    Tapia, Patrick C

    2006-01-01

    The aging process in higher mammals is increasingly being shown to feature a potentially substantial contribution from the longitudinal deterioration of normative stem cell dynamics seen with the passage of time. The precise mechanistic sequence producing this phenomenon is not entirely understood, but recent evidence has strongly implicated intracellular downstream effectors of endocrinologic pathways thought to be engaged by the obese state, specifically the insulin, IGF-1, and leptin signaling pathways. Among the intracellular effectors of these signals, a uniquely potent influence on stem cell dynamics may be attributable to Rho/ROCK, JAK kinase activity and STAT3 activity. In particular, it has already been shown that specific tyrosine kinase activities, such as that seen with Rho kinase, are presently thought to be associated with adverse health outcomes in numerous clinical contexts. Furthermore, the Rho GTPase is thought to be contributing to end-stage renal disease. However, in addition to its contribution to organ system dysfunction, the Rho/ROCK pathway has recently been shown to be activated by insulin and IGF-1, providing a tantalizing connection to nutrition and aging science. The JAK-STAT pathway, in contrast, has long been associated with pro-inflammatory cytokines, but has recently been implicated in leptin signaling as well. Importantly, JAK-STAT signaling has, similarly to Rho/ROCK signaling, been implicated as capable of accelerating stem cell proliferation. The implications of these recent determinations, in light of the recent finding of telomere attrition in humans associated with obesity, are that the intracellular determinants of aging may already be known, and the known common influence of these signaling elements on longitudinal stem cell dynamics is a pronounced induction of proliferation, an elevation that has been linked to the pathologic evolution of longitudinal organ-level dysfunction and the organismal-level physiologic decline

  6. Oncogenic Receptor Tyrosine Kinases Directly Phosphorylate Focal Adhesion Kinase (FAK) as a Resistance Mechanism to FAK-Kinase Inhibitors.

    Science.gov (United States)

    Marlowe, Timothy A; Lenzo, Felicia L; Figel, Sheila A; Grapes, Abigail T; Cance, William G

    2016-12-01

    Focal adhesion kinase (FAK) is a major drug target in cancer and current inhibitors targeted to the ATP-binding pocket of the kinase domain have entered clinical trials. However, preliminary results have shown limited single-agent efficacy in patients. Despite these unfavorable data, the molecular mechanisms that drive intrinsic and acquired resistance to FAK-kinase inhibitors are largely unknown. We have demonstrated that receptor tyrosine kinases (RTK) can directly bypass FAK-kinase inhibition in cancer cells through phosphorylation of FAK's critical tyrosine 397 (Y397). We also showed that HER2 forms a direct protein-protein interaction with the FAK-FERM-F1 lobe, promoting direct phosphorylation of Y397. In addition, FAK-kinase inhibition induced two forms of compensatory RTK reprogramming: (i) the rapid phosphorylation and activation of RTK signaling pathways in RTK High cells and (ii) the long-term acquisition of RTKs novel to the parental cell line in RTK Low cells. Finally, HER2 +: cancer cells displayed resistance to FAK-kinase inhibition in 3D growth assays using a HER2 isogenic system and HER2 + cancer cell lines. Our data indicate a novel drug resistance mechanism to FAK-kinase inhibitors whereby HER2 and other RTKs can rescue and maintain FAK activation (pY397) even in the presence of FAK-kinase inhibition. These data may have important ramifications for existing clinical trials of FAK inhibitors and suggest that individual tumor stratification by RTK expression would be important to predict patient response to FAK-kinase inhibitors. Mol Cancer Ther; 15(12); 3028-39. ©2016 AACR. ©2016 American Association for Cancer Research.

  7. Rho-associated kinase activity is required for proper morphogenesis of the inner cell mass in the mouse blastocyst.

    Science.gov (United States)

    Laeno, Arlene May A; Tamashiro, Dana Ann A; Alarcon, Vernadeth B

    2013-11-01

    The blastocyst consists of the outer layer of trophectoderm and pluripotent inner cell mass (ICM), the precursor of the placenta and fetus, respectively. During blastocyst expansion, the ICM adopts a compact, ovoidal shape, whose proper morphology is crucial for normal embryogenesis. Rho-associated kinase (ROCK), an effector of small GTPase RHO signaling, mediates the diverse cellular processes of morphogenesis, but its role in ICM morphogenesis is unclear. Here, we demonstrate that ROCK is required for cohesion of ICM cells and formation of segregated tissues called primitive endoderm (PrE) and epiblast (Epi) in the ICM of the mouse blastocyst. Blastocyst treatment with ROCK inhibitors Y-27632 and Fasudil caused widening or spreading of the ICM, and intermingling of PrE and Epi. Widening of ICM was independent of trophectoderm because isolated ICMs as well as colonies of mouse embryonic stem cells (mESC) also spread upon Y-27632 treatment. PrE, Epi, and trophectoderm cell numbers were similar between control and treated blastocysts, suggesting that ROCK inhibition affected ICM morphology but not lineage differentiation. Rock1 and Rock2 knockdown via RNA interference in mESC also induced spreading, supporting the conclusion that morphological defects caused by the pharmacological inhibitors were due to ROCK inactivation. When blastocysts were transferred into surrogates, implantation efficiencies were unaffected by ROCK inhibition, but treated blastocysts yielded greater fetal loss. These results show that proper ICM morphology is dependent on ROCK activity and is crucial for fetal development. Our studies have wider implication for improving efficiencies of human assisted reproductive technologies that diminish pregnancy loss and promote successful births.

  8. Kinase inhibitors: a new class of antirheumatic drugs

    Directory of Open Access Journals (Sweden)

    Kyttaris VC

    2012-09-01

    Full Text Available Vasileios C KyttarisDivision of Rheumatology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USAAbstract: The outlook for patients with rheumatoid arthritis has improved significantly over the last three decades with the use of disease-modifying antirheumatic drugs. However, despite the use of methotrexate, cytokine inhibitors, and molecules targeting T and B cells, a percentage of patients do not respond or lose their response over time. The autoimmune process in rheumatoid arthritis depends on activation of immune cells, which utilize intracellular kinases to respond to external stimuli such as cytokines, immune complexes, and antigens. In the past decade, small molecules targeting several kinases, such as p38 MAPK, Syk, and JAK have been developed. Several p38 MAPK inhibitors proved ineffective in treating rheumatoid arthritis. The Syk inhibitor, fostamatinib, proved superior to placebo in Phase II trials and is currently under Phase III investigation. Tofacitinib, a JAK1/3 inhibitor, was shown to be efficacious in two Phase III trials, while VX-509, a JAK3 inhibitor, showed promising results in a Phase II trial. Fostamatinib and tofacitinib were associated with increased rates of infection, elevation of liver enzymes, and neutropenia. Moreover, fostamatinib caused elevations of blood pressure and diarrhea, while tofacitinib was associated with an increase in creatinine and elevation of lipid levels.Keywords: rheumatoid arthritis, kinase inhibitors, mitogen-activated phosphokinase p38, spleen tyrosine kinase, Janus kinases

  9. Second-generation inhibitors of Bruton tyrosine kinase

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    Jingjing Wu

    2016-09-01

    Full Text Available Abstract Bruton tyrosine kinase (BTK is a critical effector molecule for B cell development and plays a major role in lymphoma genesis. Ibrutinib is the first-generation BTK inhibitor. Ibrutinib has off-target effects on EGFR, ITK, and Tec family kinases, which explains the untoward effects of ibrutinib. Resistance to ibrutinib was also reported. The C481S mutation in the BTK kinase domain was reported to be a major mechanism of resistance to ibrutinib. This review summarizes the clinical development of novel BTK inhibitors, ACP-196 (acalabrutinib, ONO/GS-4059, and BGB-3111.

  10. Spatiotemporal mechanical variation reveals critical role for rho kinase during primitive streak morphogenesis.

    Science.gov (United States)

    Henkels, Julia; Oh, Jaeho; Xu, Wenwei; Owen, Drew; Sulchek, Todd; Zamir, Evan

    2013-02-01

    Large-scale morphogenetic movements during early embryo development are driven by complex changes in biochemical and biophysical factors. Current models for amniote primitive streak morphogenesis and gastrulation take into account numerous genetic pathways but largely ignore the role of mechanical forces. Here, we used atomic force microscopy (AFM) to obtain for the first time precise biomechanical properties of the early avian embryo. Our data reveal that the primitive streak is significantly stiffer than neighboring regions of the epiblast, and that it is stiffer than the pre-primitive streak epiblast. To test our hypothesis that these changes in mechanical properties are due to a localized increase of actomyosin contractility, we inhibited actomyosin contractility via the Rho kinase (ROCK) pathway using the small-molecule inhibitor Y-27632. Our results using several different assays show the following: (1) primitive streak formation was blocked; (2) the time-dependent increase in primitive streak stiffness was abolished; and (3) convergence of epiblast cells to the midline was inhibited. Taken together, our data suggest that actomyosin contractility is necessary for primitive streak morphogenesis, and specifically, ROCK plays a critical role. To better understand the underlying mechanisms of this fundamental process, future models should account for the findings presented in this study.

  11. Diabetes and overexpression of proNGF cause retinal neurodegeneration via activation of RhoA pathway.

    Directory of Open Access Journals (Sweden)

    Mohammed M H Al-Gayyar

    Full Text Available Our previous studies showed positive correlation between accumulation of proNGF, activation of RhoA and neuronal death in diabetic models. Here, we examined the neuroprotective effects of selective inhibition of RhoA kinase in the diabetic rat retina and in a model that stably overexpressed the cleavage-resistance proNGF plasmid in the retina. Male Sprague-Dawley rats were rendered diabetic using streptozotocin or stably express cleavage-resistant proNGF plasmid. The neuroprotective effects of the intravitreal injection of RhoA kinase inhibitor Y27632 were examined in vivo. Effects of proNGF were examined in freshly isolated primary retinal ganglion cell (RGC cultures and RGC-5 cell line. Retinal neurodegeneration was assessed by counting TUNEL-positive and Brn-3a positive retinal ganglion cells. Expression of proNGF, p75(NTR, cleaved-PARP, caspase-3 and p38MAPK/JNK were examined by Western-blot. Activation of RhoA was assessed by pull-down assay and G-LISA. Diabetes and overexpression of proNGF resulted in retinal neurodegeneration as indicated by 9- and 6-fold increase in TUNEL-positive cells, respectively. In vitro, proNGF induced 5-fold cell death in RGC-5 cell line, and it induced >10-fold cell death in primary RGC cultures. These effects were associated with significant upregulation of p75(NTR and activation of RhoA. While proNGF induced TNF-α expression in vivo, it selectively activated RhoA in primary RGC cultures and RGC-5 cell line. Inhibiting RhoA kinase with Y27632 significantly reduced diabetes- and proNGF-induced activation of proapoptotic p38MAPK/JNK, expression of cleaved-PARP and caspase-3 and prevented retinal neurodegeneration in vivo and in vitro. Taken together, these results provide compelling evidence for a causal role of proNGF in diabetes-induced retinal neurodegeneration through enhancing p75(NTR expression and direct activation of RhoA and p38MAPK/JNK apoptotic pathways.

  12. Self-Assembling Peptide Nanofiber Scaffold Enhanced with RhoA Inhibitor CT04 Improves Axonal Regrowth in the Transected Spinal Cord

    Directory of Open Access Journals (Sweden)

    Weiwei Zhang

    2012-01-01

    Full Text Available The present study was designed to explore the therapeutic potential of self-assembling peptide nanofiber scaffold (SAPNS delivered RhoA inhibitor to ameliorate the hostile microenvironment of injured spinal cord for axonal regeneration. After a transection was applied to the thoracic spinal cord of mice, the combination of SAPNS and CT04 (a cell permeable RhoA inhibitor, single SAPNS with vehicle, or saline was transplanted into the lesion cavity. Results showed that SAPNS+CT04 implants achieved the best therapeutic outcomes among treatment groups. The novel combination not only reconstructed the injured nerve gap but also elicited significant axonal regeneration and motor functional recovery. Additionally, the combination also effectively reduced the apoptosis and infiltration of activated macrophages in the injured spinal cord. Collectively, the present study demonstrated that SAPNS-based delivery of RhoA inhibitor CT04 presented a highly potential therapeutic strategy for spinal cord injury with reknitting lesion gap, attenuating secondary injury, and improving axonal regrowth.

  13. Self-Assembling Peptide Nanofiber Scaffold Enhanced with RhoA Inhibitor CT04 Improves Axonal Regrowth in the Transected Spinal Cord

    International Nuclear Information System (INIS)

    Weiwei, Z.; Xiaoduo, Z.; Zhongying, L.

    2012-01-01

    The present study was designed to explore the therapeutic potential of self-assembling peptide nano fiber scaffold (SAPNS) delivered RhoA inhibitor to ameliorate the hostile microenvironment of injured spinal cord for axonal regeneration. After a transection was applied to the thoracic spinal cord of mice, the combination of SAPNS and CT04 (a cell permeable RhoA inhibitor), single SAPNS with vehicle, or saline was transplanted into the lesion cavity. Results showed that SAPNS+CT04 implants achieved the best therapeutic outcomes among treatment groups. The novel combination not only reconstructed the injured nerve gap but also elicited significant axonal regeneration and motor functional recovery. Additionally, the combination also effectively reduced the apoptosis and infiltration of activated macrophages in the injured spinal cord. Collectively, the present study demonstrated that SAPNS-based delivery of RhoA inhibitor CT04 presented a highly potential therapeutic strategy for spinal cord injury with reknitting lesion gap, attenuating secondary injury, and improving axonal regrowth.

  14. Discovery of inhibitors of bacterial histidine kinases

    NARCIS (Netherlands)

    Velikova, N.R.

    2014-01-01

    Discovery of Inhibitors of Bacterial Histidine Kinases Summary

    The thesis is on novel antibacterial drug discovery (http://youtu.be/NRMWOGgeysM). Using structure-based and fragment-based drug discovery approach, we have identified small-molecule histidine-kinase

  15. Slit and Netrin-1 guide cranial motor axon pathfinding via Rho-kinase, myosin light chain kinase and myosin II

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    Drescher Uwe

    2010-06-01

    Full Text Available Abstract Background In the developing hindbrain, cranial motor axon guidance depends on diffusible repellent factors produced by the floor plate. Our previous studies have suggested that candidate molecules for mediating this effect are Slits, Netrin-1 and Semaphorin3A (Sema3A. It is unknown to what extent these factors contribute to floor plate-derived chemorepulsion of motor axons, and the downstream signalling pathways are largely unclear. Results In this study, we have used a combination of in vitro and in vivo approaches to identify the components of floor plate chemorepulsion and their downstream signalling pathways. Using in vitro motor axon deflection assays, we demonstrate that Slits and Netrin-1, but not Sema3A, contribute to floor plate repulsion. We also find that the axon pathways of dorsally projecting branchiomotor neurons are disrupted in Netrin-1 mutant mice and in chick embryos expressing dominant-negative Unc5a receptors, indicating an in vivo role for Netrin-1. We further demonstrate that Slit and Netrin-1 signalling are mediated by Rho-kinase (ROCK and myosin light chain kinase (MLCK, which regulate myosin II activity, controlling actin retrograde flow in the growth cone. We show that MLCK, ROCK and myosin II are required for Slit and Netrin-1-mediated growth cone collapse of cranial motor axons. Inhibition of these molecules in explant cultures, or genetic manipulation of RhoA or myosin II function in vivo causes characteristic cranial motor axon pathfinding errors, including the inability to exit the midline, and loss of turning towards exit points. Conclusions Our findings suggest that both Slits and Netrin-1 contribute to floor plate-derived chemorepulsion of cranial motor axons. They further indicate that RhoA/ROCK, MLCK and myosin II are components of Slit and Netrin-1 signalling pathways, and suggest that these pathways are of key importance in cranial motor axon navigation.

  16. 2-Aminobenzimidazoles as potent Aurora kinase inhibitors.

    Science.gov (United States)

    Zhong, Min; Bui, Minna; Shen, Wang; Baskaran, Subramanian; Allen, Darin A; Elling, Robert A; Flanagan, W Michael; Fung, Amy D; Hanan, Emily J; Harris, Shannon O; Heumann, Stacey A; Hoch, Ute; Ivy, Sheryl N; Jacobs, Jeffrey W; Lam, Stuart; Lee, Heman; McDowell, Robert S; Oslob, Johan D; Purkey, Hans E; Romanowski, Michael J; Silverman, Jeffrey A; Tangonan, Bradley T; Taverna, Pietro; Yang, Wenjin; Yoburn, Josh C; Yu, Chul H; Zimmerman, Kristin M; O'Brien, Tom; Lew, Willard

    2009-09-01

    This Letter describes the discovery and key structure-activity relationship (SAR) of a series of 2-aminobenzimidazoles as potent Aurora kinase inhibitors. 2-Aminobenzimidazole serves as a bioisostere of the biaryl urea residue of SNS-314 (1c), which is a potent Aurora kinase inhibitor and entered clinical testing in patients with solid tumors. Compared to SNS-314, this series of compounds offers better aqueous solubility while retaining comparable in vitro potency in biochemical and cell-based assays; in particular, 6m has also demonstrated a comparable mouse iv PK profile to SNS-314.

  17. An adventitious interaction of filamin A with RhoGDI2(Tyr153Glu)

    International Nuclear Information System (INIS)

    Song, Mia; He, Qianjing; Berk, Benjamin-Andreas; Hartwig, John H.; Stossel, Thomas P.; Nakamura, Fumihiko

    2016-01-01

    Filamin A (FLNA) is an actin filament crosslinking protein with multiple intracellular binding partners. Mechanical force exposes cryptic FLNA binding sites for some of these ligands. To identify new force-dependent binding interactions, we used a fusion construct composed of two FLNA domains, one of which was previously identified as containing a force-dependent binding site as a bait in a yeast two-hybrid system and identified the Rho dissociation inhibitor 2 (RhoGDI2) as a potential interacting partner. A RhoGDI2 truncate with 81 N-terminal amino acid residues and a phosphomimetic mutant, RhoGDI(Tyr153Glu) interacted with the FLNA construct. However, neither wild-type or full-length RhoGDI2 phosphorylated at Y153 interacted with FLNA. Our interpretation of these contradictions is that truncation and/or mutation of RhoGDI2 perturbs its conformation to expose a site that adventitiously binds FLNA and is not a bona–fide interaction. Therefore, previous studies reporting that a RhoGDI(Y153E) mutant suppresses the metastasis of human bladder cancer cells must be reinvestigated in light of artificial interaction of this point mutant with FLNA. - Highlights: • RhoGDI2 is identified as a potential filamin A (FLNA)-binding partner. • Phosphomimetic mutant, RhoGDI2(Tyr153Glu) interacts with FLNA. • RhoGDI2 phosphorylated (Tyr153) by src kinase does not interact with FLNA. • Mutation of Tyr-153 to Glu of RhoGDI2 does not mimic phosphorylation. • RhoGDI2(Tyr153Glu) provokes an adventitious interaction with FLNA.

  18. An adventitious interaction of filamin A with RhoGDI2(Tyr153Glu)

    Energy Technology Data Exchange (ETDEWEB)

    Song, Mia; He, Qianjing [Hematology Division, Department of Medicine, Brigham and Women' s Hospital, Harvard Medical School, Boston MA (United States); Berk, Benjamin-Andreas [Faculty of Veterinary Medicine and Faculty of Biosciences and Pharmacy, University of Leipzig, Leipzig (Germany); Hartwig, John H.; Stossel, Thomas P. [Hematology Division, Department of Medicine, Brigham and Women' s Hospital, Harvard Medical School, Boston MA (United States); Nakamura, Fumihiko, E-mail: fnakamura@partners.org [Hematology Division, Department of Medicine, Brigham and Women' s Hospital, Harvard Medical School, Boston MA (United States)

    2016-01-15

    Filamin A (FLNA) is an actin filament crosslinking protein with multiple intracellular binding partners. Mechanical force exposes cryptic FLNA binding sites for some of these ligands. To identify new force-dependent binding interactions, we used a fusion construct composed of two FLNA domains, one of which was previously identified as containing a force-dependent binding site as a bait in a yeast two-hybrid system and identified the Rho dissociation inhibitor 2 (RhoGDI2) as a potential interacting partner. A RhoGDI2 truncate with 81 N-terminal amino acid residues and a phosphomimetic mutant, RhoGDI(Tyr153Glu) interacted with the FLNA construct. However, neither wild-type or full-length RhoGDI2 phosphorylated at Y153 interacted with FLNA. Our interpretation of these contradictions is that truncation and/or mutation of RhoGDI2 perturbs its conformation to expose a site that adventitiously binds FLNA and is not a bona–fide interaction. Therefore, previous studies reporting that a RhoGDI(Y153E) mutant suppresses the metastasis of human bladder cancer cells must be reinvestigated in light of artificial interaction of this point mutant with FLNA. - Highlights: • RhoGDI2 is identified as a potential filamin A (FLNA)-binding partner. • Phosphomimetic mutant, RhoGDI2(Tyr153Glu) interacts with FLNA. • RhoGDI2 phosphorylated (Tyr153) by src kinase does not interact with FLNA. • Mutation of Tyr-153 to Glu of RhoGDI2 does not mimic phosphorylation. • RhoGDI2(Tyr153Glu) provokes an adventitious interaction with FLNA.

  19. Approved and Experimental Small-Molecule Oncology Kinase Inhibitor Drugs: A Mid-2016 Overview.

    Science.gov (United States)

    Fischer, Peter M

    2017-03-01

    Kinase inhibitor research is a comparatively recent branch of medicinal chemistry and pharmacology and the first small-molecule kinase inhibitor, imatinib, was approved for clinical use only 15 years ago. Since then, 33 more kinase inhibitor drugs have received regulatory approval for the treatment of a variety of cancers and the volume of reports on the discovery and development of kinase inhibitors has increased to an extent where it is now difficult-even for those working in the field-easily to keep an overview of the compounds that are being developed, as currently there are 231 such compounds, targeting 38 different protein and lipid kinases (not counting isoforms), in clinical use or under clinical investigation. The purpose of this review is thus to provide an overview of the biomedical rationales for the kinases being targeted on the one hand, and the design principles, as well as chemical, pharmacological, pharmaceutical, and toxicological kinase inhibitor properties, on the other hand. Two issues that are especially important in kinase inhibitor research, target selectivity and drug resistance, as well as the underlying structural concepts, are discussed in general terms and in the context of relevant kinases and their inhibitors. © 2016 Wiley Periodicals, Inc.

  20. Computational methods for analysis and inference of kinase/inhibitor relationships

    Directory of Open Access Journals (Sweden)

    Fabrizio eFerrè

    2014-06-01

    Full Text Available The central role of kinases in virtually all signal transduction networks is the driving motivation for the development of compounds modulating their activity. ATP-mimetic inhibitors are essential tools for elucidating signaling pathways and are emerging as promising therapeutic agents. However, off-target ligand binding and complex and sometimes unexpected kinase/inhibitor relationships can occur for seemingly unrelated kinases, stressing that computational approaches are needed for learning the interaction determinants and for the inference of the effect of small compounds on a given kinase. Recently published high-throughput profiling studies assessed the effects of thousands of small compound inhibitors, covering a substantial portion of the kinome. This wealth of data paved the road for computational resources and methods that can offer a major contribution in understanding the reasons of the inhibition, helping in the rational design of more specific molecules, in the in silico prediction of inhibition for those neglected kinases for which no systematic analysis has been carried yet, in the selection of novel inhibitors with desired selectivity, and offering novel avenues of personalized therapies.

  1. A chemically defined culture medium containing Rho kinase inhibitor Y-27632 for the fabrication of stratified squamous epithelial cell grafts

    International Nuclear Information System (INIS)

    Aslanova, Afag; Takagi, Ryo; Yamato, Masayuki; Okano, Teruo; Yamamoto, Masakazu

    2015-01-01

    With the development of a culture method for stratified squamous epithelial cells, tissue-engineered epithelial cell sheets have been successfully applied as clinical cell grafts. However, the implementation of these cell sheets without the use of any animal-derived materials is highly desirable. In this study, Rho-associated protein kinase inhibitor Y-27632 was used to develop a chemically defined culture medium for the fabrication of stratified epithelial cell grafts consisting of human epidermal and oral keratinocytes, and the proliferation activity, cell morphology, and gene expressions of the keratinocytes were analyzed. The results of a colorimetric assay indicated that Y-27632 significantly promoted the proliferation of the keratinocytes in culture media both with and without fetal bovine serum (FBS), although there were no indications of Y-27632 efficacy on cell morphology and stratification of the keratinocytes in culture medium without any animal-derived materials. The results of quantitative RT-PCR revealed that gene expressions correlated with cell adhesion, cell–cell junction, proliferation markers, and stem/progenitor markers in cultured keratinocytes were not strongly affected by the addition of Y-27632 to the culture medium. Moreover, gene expressions of differentiation markers in stratified keratinocytes cultured in medium without FBS were nearly identical to those of keratinocytes co-cultured with 3T3 feeder cells. Interestingly, the expressions of differentiation markers in cultured stratified keratinocytes were suppressed by FBS, whereas they were reconstructed by either co-culture of a 3T3 feeder layer or addition of Y-27632 into the culture medium containing FBS. These findings indicate that Y-27632 is a useful supplement for the development of a chemically defined culture medium for fabrication of stratified epithelial cell grafts for clinical applications for the purpose of developing the culture medium with a lower risk of pathogen

  2. A chemically defined culture medium containing Rho kinase inhibitor Y-27632 for the fabrication of stratified squamous epithelial cell grafts

    Energy Technology Data Exchange (ETDEWEB)

    Aslanova, Afag [Department of Surgery, Institute of Gastroenterology, Tokyo Women' s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666 (Japan); Institute of Advanced Biomedical Engineering and Science, Tokyo Women' s Medical University, TWIns, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666 (Japan); Takagi, Ryo; Yamato, Masayuki; Okano, Teruo [Institute of Advanced Biomedical Engineering and Science, Tokyo Women' s Medical University, TWIns, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666 (Japan); Yamamoto, Masakazu, E-mail: yamamoto.ige@twmu.ac.jp [Department of Surgery, Institute of Gastroenterology, Tokyo Women' s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666 (Japan)

    2015-05-01

    With the development of a culture method for stratified squamous epithelial cells, tissue-engineered epithelial cell sheets have been successfully applied as clinical cell grafts. However, the implementation of these cell sheets without the use of any animal-derived materials is highly desirable. In this study, Rho-associated protein kinase inhibitor Y-27632 was used to develop a chemically defined culture medium for the fabrication of stratified epithelial cell grafts consisting of human epidermal and oral keratinocytes, and the proliferation activity, cell morphology, and gene expressions of the keratinocytes were analyzed. The results of a colorimetric assay indicated that Y-27632 significantly promoted the proliferation of the keratinocytes in culture media both with and without fetal bovine serum (FBS), although there were no indications of Y-27632 efficacy on cell morphology and stratification of the keratinocytes in culture medium without any animal-derived materials. The results of quantitative RT-PCR revealed that gene expressions correlated with cell adhesion, cell–cell junction, proliferation markers, and stem/progenitor markers in cultured keratinocytes were not strongly affected by the addition of Y-27632 to the culture medium. Moreover, gene expressions of differentiation markers in stratified keratinocytes cultured in medium without FBS were nearly identical to those of keratinocytes co-cultured with 3T3 feeder cells. Interestingly, the expressions of differentiation markers in cultured stratified keratinocytes were suppressed by FBS, whereas they were reconstructed by either co-culture of a 3T3 feeder layer or addition of Y-27632 into the culture medium containing FBS. These findings indicate that Y-27632 is a useful supplement for the development of a chemically defined culture medium for fabrication of stratified epithelial cell grafts for clinical applications for the purpose of developing the culture medium with a lower risk of pathogen

  3. Rho-associated kinase (ROCK) function is essential for cell cycle progression, senescence and tumorigenesis.

    Science.gov (United States)

    Kümper, Sandra; Mardakheh, Faraz K; McCarthy, Afshan; Yeo, Maggie; Stamp, Gordon W; Paul, Angela; Worboys, Jonathan; Sadok, Amine; Jørgensen, Claus; Guichard, Sabrina; Marshall, Christopher J

    2016-01-14

    Rho-associated kinases 1 and 2 (ROCK1/2) are Rho-GTPase effectors that control key aspects of the actin cytoskeleton, but their role in proliferation and cancer initiation or progression is not known. Here, we provide evidence that ROCK1 and ROCK2 act redundantly to maintain actomyosin contractility and cell proliferation and that their loss leads to cell-cycle arrest and cellular senescence. This phenotype arises from down-regulation of the essential cell-cycle proteins CyclinA, CKS1 and CDK1. Accordingly, while the loss of either Rock1 or Rock2 had no negative impact on tumorigenesis in mouse models of non-small cell lung cancer and melanoma, loss of both blocked tumor formation, as no tumors arise in which both Rock1 and Rock2 have been genetically deleted. Our results reveal an indispensable role for ROCK, yet redundant role for isoforms 1 and 2, in cell cycle progression and tumorigenesis, possibly through the maintenance of cellular contractility.

  4. The selectivity and promiscuity of brain-neuroregenerative inhibitors between ROCK1 and ROCK2 isoforms: An integration of SB-QSSR modelling, QM/MM analysis and in vitro kinase assay.

    Science.gov (United States)

    Zhu, L; Yang, Y; Lu, X

    2016-01-01

    The Rho-associated kinases (ROCKs) have long been recognized as an attractive therapeutic target for various neurological diseases; selective inhibition of ROCK1 and ROCK2 isoforms would result in distinct biological effects on neurogenesis, neuroplasticity and neuroregeneration after brain surgery and traumatic brain injury. However, the discovery and design of isoform-selective inhibitors remain a great challenge due to the high conservation and similarity between the kinase domains of ROCK1 and ROCK2. Here, a structure-based quantitative structure-selectivity relationship (SB-QSSR) approach was used to correlate experimentally measured selectivity with the difference in inhibitor binding to the two kinase isoforms. The resulting regression models were examined rigorously through both internal cross-validation and external blind validation; a nonlinear predictor was found to have high fitting stability and strong generalization ability, which was then employed to perform virtual screening against a structurally diverse, drug-like compound library. Consequently, five and seven hits were identified as promising candidates of 1-o-2 and 2-o-1 selective inhibitors, respectively, from which seven purchasable compounds were tested in vitro using a standard kinase assay protocol to determine their inhibitory activity against and selectivity between ROCK1 and ROCK2. The structural basis, energetic property and biological implication underlying inhibitor selectivity and promiscuity were also investigated systematically using a hybrid quantum mechanics/molecular mechanics (QM/MM) scheme.

  5. Canine osteosarcoma cells exhibit resistance to aurora kinase inhibitors.

    Science.gov (United States)

    Cannon, C M; Pozniak, J; Scott, M C; Ito, D; Gorden, B H; Graef, A J; Modiano, J F

    2015-03-01

    We evaluated the effect of Aurora kinase inhibitors AZD1152 and VX680 on canine osteosarcoma cells. Cytotoxicity was seen in all four cell lines; however, half-maximal inhibitory concentrations were significantly higher than in human leukaemia and canine lymphoma cells. AZD1152 reduced Aurora kinase B phosphorylation, indicating resistance was not because of failure of target recognition. Efflux mediated by ABCB1 and ABCG2 transporters is one known mechanism of resistance against these drugs and verapamil enhanced AZD1152-induced apoptosis; however, these transporters were only expressed by a small percentage of cells in each line and the effects of verapamil were modest, suggesting other mechanisms contribute to resistance. Our results indicate that canine osteosarcoma cells are resistant to Aurora kinase inhibitors and suggest that these compounds are unlikely to be useful as single agents for this disease. Further investigation of these resistance mechanisms and the potential utility of Aurora kinase inhibitors in multi-agent protocols is warranted. © 2013 Blackwell Publishing Ltd.

  6. Effect of kinase inhibitors on the therapeutic properties of monoclonal antibodies.

    Science.gov (United States)

    Duong, Minh Ngoc; Matera, Eva-Laure; Mathé, Doriane; Evesque, Anne; Valsesia-Wittmann, Sandrine; Clémenceau, Béatrice; Dumontet, Charles

    2015-01-01

    Targeted therapies of malignancies currently consist of therapeutic monoclonal antibodies and small molecule kinase inhibitors. The combination of these novel agents raises the issue of potential antagonisms. We evaluated the potential effect of 4 kinase inhibitors, including the Bruton tyrosine kinase inhibitor ibrutinib, and 3 PI3K inhibitors idelalisib, NVP-BEZ235 and LY294002, on the effects of the 3 monoclonal antibodies, rituximab and obinutuzumab (directed against CD20) and trastuzumab (directed against HER2). We found that ibrutinib potently inhibits antibody-dependent cell-mediated cytotoxicity exerted by all antibodies, with a 50% inhibitory concentration of 0.2 microM for trastuzumab, 0.5 microM for rituximab and 2 microM for obinutuzumab, suggesting a lesser effect in combination with obinutuzumab than with rituximab. The 4 kinase inhibitors were found to inhibit phagocytosis by fresh human neutrophils, as well as antibody-dependent cellular phagocytosis induced by the 3 antibodies. Conversely co-administration of ibrutinib with rituximab, obinutuzumab or trastuzumab did not demonstrate any inhibitory effect of ibrutinib in vivo in murine xenograft models. In conclusion, some kinase inhibitors, in particular, ibrutinib, are likely to exert inhibitory effects on innate immune cells. However, these effects do not compromise the antitumor activity of monoclonal antibodies in vivo in the models that were evaluated.

  7. Clinical Pharmacology of Kinase Inhibitors in Oncology : Personalized and Optimzed Dosing

    NARCIS (Netherlands)

    Verheijen, Remy B.

    2017-01-01

    Kinase inhibitors are an important category of molecularly targeted therapies used for cancer. Verheijen’s doctoral thesis describes several clinical pharmacological studies to optimize and personalize the treatment of cancer with kinase inhibitors, using pharmacokinetics, molecular imaging and

  8. Phosphodiesterase inhibitor KMUP-3 displays cardioprotection via protein kinase G and increases cardiac output via G-protein-coupled receptor agonist activity and Ca2+ sensitization

    Directory of Open Access Journals (Sweden)

    Chung-Pin Liu

    2016-02-01

    Full Text Available KMUP-3 (7-{2-[4-(4-nitrobenzene piperazinyl]ethyl}-1, 3-dimethylxanthine displays cardioprotection and increases cardiac output, and is suggested to increase cardiac performance and improve myocardial infarction. To determine whether KMUP-3 improves outcomes in hypoperfused myocardium by inducing Ca2+ sensitization to oppose protein kinase (PKG-mediated Ca2+ blockade, we measured left ventricular systolic blood pressure, maximal rates of pressure development, mean arterial pressure and heart rate in rats, and measured contractility and expression of PKs/RhoA/Rho kinase (ROCKII in beating guinea pig left atria. Hemodynamic changes induced by KMUP-3 (0.5–3.0 mg/kg, intravenously were inhibited by Y27632 [(R-(+-trans-4-1-aminoethyl-N-(4-Pyridyl cyclohexane carboxamide] and ketanserin (1 mg/kg, intravenously. In electrically stimulated left guinea pig atria, positive inotropy induced by KMUP-3 (0.1–100μM was inhibited by the endothelial NO synthase (eNOS inhibitors N-nitro-l-arginine methyl ester (L-NAME and 7-nitroindazole, cyclic AMP antagonist SQ22536 [9-(terahydro-2-furanyl-9H-purin-6-amine], soluble guanylyl cyclase (sGC antagonist ODQ (1H-[1,2,4] oxadiazolo[4,3-a] quinoxalin-1-one, RhoA inhibitor C3 exoenzyme, β-blocker propranolol, 5-hydroxytryptamine 2A antagonist ketanserin, ROCK inhibitor Y27632 and KMUP-1 (7-{2-[4-(2-chlorobenzene piperazinyl]ethyl}-1, 3-dimethylxanthine at 10μM. Western blotting assays indicated that KMUP-3 (0.1–10μM increased PKA, RhoA/ROCKII, and PKC translocation and CIP-17 (an endogenous 17-kDa inhibitory protein activation. In spontaneous right atria, KMUP-3 induced negative chronotropy that was blunted by 7-nitroindazole and atropine. In neonatal myocytes, L-NAME inhibited KMUP-3-induced eNOS phosphorylation and RhoA/ROCK activation. In H9c2 cells, Y-27632 (50μM and PKG antagonist KT5823 [2,3,9,10,11,12-hexahydro-10R- methoxy-2,9-dimethyl-1-oxo-9S,12R-epoxy-1H-diindolo(1,2,3-fg:3′,2′,1

  9. Novel Bruton's tyrosine kinase inhibitors currently in development

    Directory of Open Access Journals (Sweden)

    D'Cruz OJ

    2013-03-01

    Full Text Available Osmond J D'Cruz,1 Fatih M Uckun1,21Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Los Angeles, CA, USA; 2Department of Pediatrics, University of Southern California, Los Angeles, CA, USAAbstract: Bruton's tyrosine kinase (Btk is intimately involved in multiple signal-transduction pathways regulating survival, activation, proliferation, and differentiation of B-lineage lymphoid cells. Btk is overexpressed and constitutively active in several B-lineage lymphoid malignancies. Btk has emerged as a new antiapoptotic molecular target for treatment of B-lineage leukemias and lymphomas. Preclinical and early clinical results indicate that Btk inhibitors may be useful in the treatment of leukemias and lymphomas.Keywords: tyrosine kinase, personalized therapy, kinase inhibitors, Btk, leukemia, lymphoma

  10. Serine34 phosphorylation of RHO guanine dissociation inhibitor (RHOGDI{alpha}) links signaling from conventional protein kinase C to RHO GTPase in cell adhesion

    DEFF Research Database (Denmark)

    Dovas, Athanassios; Choi, Youngsil; Yoneda, Atsuko

    2010-01-01

    . Phosphospecific antibodies reveal endogenous phosphorylation in several cell types that is sensitive to adhesion events triggered, for example, by hepatocyte growth factor. Phosphorylation is also sensitive to PKC inhibition. Together with FRET microscopy sensing GTP-RhoA levels, the data reveal a common pathway...

  11. Regulation of white and brown adipocyte differentiation by RhoGAP DLC1.

    Directory of Open Access Journals (Sweden)

    Choon Kiat Sim

    Full Text Available Adipose tissues constitute an important component of metabolism, the dysfunction of which can cause obesity and type II diabetes. Here we show that differentiation of white and brown adipocytes requires Deleted in Liver Cancer 1 (DLC1, a Rho GTPase Activating Protein (RhoGAP previously studied for its function in liver cancer. We identified Dlc1 as a super-enhancer associated gene in both white and brown adipocytes through analyzing the genome-wide binding profiles of PPARγ, the master regulator of adipogenesis. We further observed that Dlc1 expression increases during differentiation, and knockdown of Dlc1 by siRNA in white adipocytes reduces the formation of lipid droplets and the expression of fat marker genes. Moreover, knockdown of Dlc1 in brown adipocytes reduces expression of brown fat-specific genes and diminishes mitochondrial respiration. Dlc1-/- knockout mouse embryonic fibroblasts show a complete inability to differentiate into adipocytes, but this phenotype can be rescued by inhibitors of Rho-associated kinase (ROCK and filamentous actin (F-actin, suggesting the involvement of Rho pathway in DLC1-regulated adipocyte differentiation. Furthermore, PPARγ binds to the promoter of Dlc1 gene to regulate its expression during both white and brown adipocyte differentiation. These results identify DLC1 as an activator of white and brown adipocyte differentiation, and provide a molecular link between PPARγ and Rho pathways.

  12. Kindlin-2 Association with Rho GDP-Dissociation Inhibitor α Suppresses Rac1 Activation and Podocyte Injury.

    Science.gov (United States)

    Sun, Ying; Guo, Chen; Ma, Ping; Lai, Yumei; Yang, Fan; Cai, Jun; Cheng, Zhehao; Zhang, Kuo; Liu, Zhongzhen; Tian, Yeteng; Sheng, Yue; Tian, Ruijun; Deng, Yi; Xiao, Guozhi; Wu, Chuanyue

    2017-12-01

    Alteration of podocyte behavior is critically involved in the development and progression of many forms of human glomerular diseases. The molecular mechanisms that control podocyte behavior, however, are not well understood. Here, we investigated the role of Kindlin-2, a component of cell-matrix adhesions, in podocyte behavior in vivo Ablation of Kindlin-2 in podocytes resulted in alteration of actin cytoskeletal organization, reduction of the levels of slit diaphragm proteins, effacement of podocyte foot processes, and ultimately massive proteinuria and death due to kidney failure. Through proteomic analyses and in vitro coimmunoprecipitation experiments, we identified Rho GDP-dissociation inhibitor α (RhoGDI α ) as a Kindlin-2-associated protein. Loss of Kindlin-2 in podocytes significantly reduced the expression of RhoGDI α and resulted in the dissociation of Rac1 from RhoGDI α , leading to Rac1 hyperactivation and increased motility of podocytes. Inhibition of Rac1 activation effectively suppressed podocyte motility and alleviated the podocyte defects and proteinuria induced by the loss of Kindlin-2 in vivo Our results identify a novel Kindlin-2-RhoGDI α -Rac1 signaling axis that is critical for regulation of podocyte structure and function in vivo and provide evidence that it may serve as a useful target for therapeutic control of podocyte injury and associated glomerular diseases. Copyright © 2017 by the American Society of Nephrology.

  13. Rho kinase inhibitor Y-27632 promotes the differentiation of human bone marrow mesenchymal stem cells into keratinocyte-like cells in xeno-free conditioned medium.

    Science.gov (United States)

    Li, Zhenzhen; Han, Shichao; Wang, Xingqin; Han, Fu; Zhu, Xiongxiang; Zheng, Zhao; Wang, Hongtao; Zhou, Qin; Wang, Yunchuan; Su, Linlin; Shi, Jihong; Tang, Chaowu; Hu, Dahai

    2015-03-11

    Bone marrow mesenchymal stem cells (BMSCs), which have the ability to self-renew and to differentiate into multiple cell types, have recently become a novel strategy for cell-based therapies. The differentiation of BMSCs into keratinocytes may be beneficial for patients with burns, disease, or trauma. However, the currently available cells are exposed to animal materials during their cultivation and induction. These xeno-contaminations severely limit their clinical outcomes. Previous studies have shown that the Rho kinase (ROCK) inhibitor Y-27632 can promote induction efficiency and regulate the self-renewal and differentiation of stem cells. In the present study, we attempted to establish a xeno-free system for the differentiation of BMSCs into keratinocytes and to investigate whether Y-27632 can facilitate this differentiation. BMSCs isolated from patients were cultured by using a xeno-free system and characterised by using flow cytometric analysis and adipogenic and osteogenic differentiation assays. Human primary keratinocytes were also isolated from patients. Then, the morphology, population doubling time, and β-galactosidase staining level of these cells were evaluated in the presence or absence of Y-27632 to determine the effects of Y-27632 on the state of the keratinocytes. Keratinocyte-like cells (KLCs) were detected at different time points by immunocytofluorescence analysis. Moreover, the efficiency of BMSC differentiation under different conditions was measured by quantitative real-time-polymerase chain reaction (RT-PCR) and Western blot analyses. The ROCK inhibitor Y-27632 promoted the proliferation and lifespan of human primary keratinocytes. In addition, we showed that keratinocyte-specific markers could be detected in BMSCs cultured in a xeno-free system using keratinocyte-conditioned medium (KCM) independent of the presence of Y-27632. However, the efficiency of the differentiation of BMSCs into KLCs was significantly higher in the presence of Y

  14. Recent Advances in the Development and Application of Radiolabeled Kinase Inhibitors for PET Imaging

    Directory of Open Access Journals (Sweden)

    Vadim Bernard-Gauthier

    2015-12-01

    Full Text Available Over the last 20 years, intensive investigation and multiple clinical successes targeting protein kinases, mostly for cancer treatment, have identified small molecule kinase inhibitors as a prominent therapeutic class. In the course of those investigations, radiolabeled kinase inhibitors for positron emission tomography (PET imaging have been synthesized and evaluated as diagnostic imaging probes for cancer characterization. Given that inhibitor coverage of the kinome is continuously expanding, in vivo PET imaging will likely find increasing applications for therapy monitoring and receptor density studies both in- and outside of oncological conditions. Early investigated radiolabeled inhibitors, which are mostly based on clinically approved tyrosine kinase inhibitor (TKI isotopologues, have now entered clinical trials. Novel radioligands for cancer and PET neuroimaging originating from novel but relevant target kinases are currently being explored in preclinical studies. This article reviews the literature involving radiotracer design, radiochemistry approaches, biological tracer evaluation and nuclear imaging results of radiolabeled kinase inhibitors for PET reported between 2010 and mid-2015. Aspects regarding the usefulness of pursuing selective vs. promiscuous inhibitor scaffolds and the inherent challenges associated with intracellular enzyme imaging will be discussed.

  15. Resorufin: a lead for a new protein kinase CK2 inhibitor

    DEFF Research Database (Denmark)

    Sandholt, Iben Skjøth; Olsen, Birgitte Brinkmann; Guerra, Barbara

    2009-01-01

    Screening a natural compound library led to the identification of resorufin as a highly selective and potent inhibitor of protein kinase CK2. Out of 52 kinases tested, only CK2 was inhibited, in contrast to emodin, a structurally related, known CK2 inhibitor that, in addition to CK2, inhibited te...

  16. FDA-approved small-molecule kinase inhibitors

    DEFF Research Database (Denmark)

    Wu, Peng; Nielsen, Thomas E.; Clausen, Mads Hartvig

    2015-01-01

    Kinases have emerged as one of the most intensivelypursued targets in current pharmacological research,especially for cancer, due to their critical roles in cellularsignaling. To date, the US FDA has approved 28 smallmoleculekinase inhibitors, half of which were approvedin the past 3 years. While...

  17. Downstream components of RhoA required for signal pathway of superoxide formation during phagocytosis of serum opsonized zymosans in macrophages.

    Science.gov (United States)

    Kim, Jun Sub; Kim, Jae Gyu; Jeon, Chan Young; Won, Ha Young; Moon, Mi Young; Seo, Ji Yeon; Kim, Jong Il; Kim, Jaebong; Lee, Jae Yong; Choi, Soo Young; Park, Jinseu; Yoon Park, Jung Han; Ha, Kwon Soo; Kim, Pyeung Hyeun; Park, Jae Bong

    2005-12-31

    Rac1 and Rac2 are essential for the control of oxidative burst catalyzed by NADPH oxidase. It was also documented that Rho is associated with the superoxide burst reaction during phagocytosis of serum- (SOZ) and IgG-opsonized zymosan particles (IOZ). In this study, we attempted to reveal the signal pathway components in the superoxide formation regulated by Rho GTPase. Tat-C3 blocked superoxide production, suggesting that RhoA is essentially involved in superoxide formation during phagocytosis of SOZ. Conversely SOZ activated both RhoA and Rac1/2. Inhibition of RhoA-activated kinase (ROCK), an important downstream effector of RhoA, by Y27632 and myosin light chain kinase (MLCK) by ML-7 abrogated superoxide production by SOZ. Extracellular signaling-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase (MAPK) were activated during phagocytosis of SOZ, and Tat-C3 and SB203580 reduced ERK1/2 and p38 MAPK activation, suggesting that RhoA and p38 MAPK may be upstream regulators of ERK1/2. Inhibition of ERK1/2, p38 MAPK, phosphatidyl inositol 3-kinase did not block translocation of RhoA to membranes, suggesting that RhoA is upstream to these kinases. Inhibition of RhoA by Tat-C3 blocked phosphorylation of p47(PHOX). Taken together, RhoA, ROCK, p38MAPK, ERK1/2, and p47(PHOX) may be subsequently activated, leading to activation of NADPH oxidase to produce superoxide.

  18. ROCK inhibitors in ocular disease

    Directory of Open Access Journals (Sweden)

    Eva Halasz

    2016-12-01

    Full Text Available Rho kinases (ROCKs have a crucial role in actin-cytoskeletal reorganization and thus are involved in broad aspects of cell motility, from smooth muscle contraction to neurite outgrowth. The first marketed ROCK inhibitor, called fasudil, has been used safely for treatment of cerebral vasospasm since 1995 in Japan. During the succeeding decades ROCK inhibitors have been applied in many pathological conditions from central nervous system disorders to cardiovascular disease as potential therapeutic agents or experimental tools to help understand the underlying (pathomechanisms. In 2014, a fasudil derivate named ripasudil was accepted for clinical use in glaucoma and ocular hypertension. Since ROCK kinases are widely expressed in ocular tissues, they have been implicated in the pathology of many ocular conditions such as corneal dysfunction, glaucoma, cataract, diabetic retinopathy, age-related macular degeneration, and retinal detachment. This paper aims to provide an overview of the most recent status/application of ROCK inhibitors in the field of eye disease.

  19. Aurora B kinase inhibition in mitosis: strategies for optimising the use of aurora kinase inhibitors such as AT9283.

    Science.gov (United States)

    Curry, Jayne; Angove, Hayley; Fazal, Lynsey; Lyons, John; Reule, Matthias; Thompson, Neil; Wallis, Nicola

    2009-06-15

    Aurora kinases play a key role in regulating mitotic division and are attractive oncology targets. AT9283, a multi-targeted kinase inhibitor with potent activity against Aurora A and B kinases, inhibited growth and survival of multiple solid tumor cell lines and was efficacious in mouse xenograft models. AT9283-treatment resulted in endoreduplication and ablation of serine-10 histone H3 phosphorylation in both cells and tumor samples, confirming that in these models it acts as an Aurora B kinase inhibitor. In vitro studies demonstrated that exposure to AT9283 for one complete cell cycle committed an entire population of p53 checkpoint-compromised cells (HCT116) to multinucleation and death whereas treatment of p53 checkpoint-competent cells (HMEC, A549) for a similar length of time led to a reversible arrest of cells with 4N DNA. Further studies in synchronized cell populations suggested that exposure to AT9283 during mitosis was critical for optimal cytotoxicity. We therefore investigated ways in which these properties might be exploited to optimize the efficacy and therapeutic index of Aurora kinase inhibitors for p53 checkpoint compromised tumors in vivo. Combining Aurora B kinase inhibition with paclitaxel, which arrests cells in mitosis, in a xenograft model resulted in promising efficacy without additional toxicity. These findings have implications for optimizing the efficacy of Aurora kinase inhibitors in clinical practice.

  20. Chemical Proteomics Reveals Ferrochelatase as a Common Off-target of Kinase Inhibitors.

    Science.gov (United States)

    Klaeger, Susan; Gohlke, Bjoern; Perrin, Jessica; Gupta, Vipul; Heinzlmeir, Stephanie; Helm, Dominic; Qiao, Huichao; Bergamini, Giovanna; Handa, Hiroshi; Savitski, Mikhail M; Bantscheff, Marcus; Médard, Guillaume; Preissner, Robert; Kuster, Bernhard

    2016-05-20

    Many protein kinases are valid drug targets in oncology because they are key components of signal transduction pathways. The number of clinical kinase inhibitors is on the rise, but these molecules often exhibit polypharmacology, potentially eliciting desired and toxic effects. Therefore, a comprehensive assessment of a compound's target space is desirable for a better understanding of its biological effects. The enzyme ferrochelatase (FECH) catalyzes the conversion of protoporphyrin IX into heme and was recently found to be an off-target of the BRAF inhibitor Vemurafenib, likely explaining the phototoxicity associated with this drug in melanoma patients. This raises the question of whether FECH binding is a more general feature of kinase inhibitors. To address this, we applied a chemical proteomics approach using kinobeads to evaluate 226 clinical kinase inhibitors for their ability to bind FECH. Surprisingly, low or submicromolar FECH binding was detected for 29 of all compounds tested and isothermal dose response measurements confirmed target engagement in cells. We also show that Vemurafenib, Linsitinib, Neratinib, and MK-2461 reduce heme levels in K562 cells, verifying that drug binding leads to a loss of FECH activity. Further biochemical and docking experiments identified the protoporphyrin pocket in FECH as one major drug binding site. Since the genetic loss of FECH activity leads to photosensitivity in humans, our data strongly suggest that FECH inhibition by kinase inhibitors is the molecular mechanism triggering photosensitivity in patients. We therefore suggest that a FECH assay should generally be part of the preclinical molecular toxicology package for the development of kinase inhibitors.

  1. Structural Biology Insight for the Design of Sub-type Selective Aurora Kinase Inhibitors.

    Science.gov (United States)

    Sarvagalla, Sailu; Coumar, Mohane Selvaraj

    2015-01-01

    Aurora kinase A, B and C, are key regulators of mitosis and are over expressed in many of the human cancers, making them an ideal drug target for cancer chemotherapy. Currently, over a dozen of Aurora kinase inhibitors are in various phases of clinical development. The majority of the inhibitors (VX-680/MK-0457, PHA-739358, CYC116, SNS-314, AMG 900, AT-9283, SCH- 1473759, ABT-348, PF-03814735, R-763/AS-703569, KW-2449 and TAK-901) are pan-selective (isoform non-selective) and few are Aurora A (MLN8054, MLN8237, VX-689/MK5108 and ENMD 2076) and Aurora B (AZD1152 and GSK1070916) sub-type selective. Despite the intensive research efforts in the past decade, no Aurora kinase inhibitor has reached the market. Recent evidence suggests that the sub-type selective Aurora kinase A inhibitor could possess advantages over pan-selective Aurora inhibitors, by avoiding Aurora B mediated neutropenia. However, sub-type selective Aurora kinase A inhibitor design is very challenging due to the similarity in the active site among the isoforms. Structural biology and computational aspects pertaining to the design of Aurora kinase inhibitors were analyzed and found that a possible means to develop sub-type selective inhibitor is by targeting Aurora A specific residues (Leu215, Thr217 and Arg220) or Aurora B specific residues (Arg159, Glu161 and Lys164), near the solvent exposed region of the protein. Particularly, a useful strategy for the design of sub-type selective Aurora A inhibitor could be by targeting Thr217 residue as in the case of MLN8054. Further preclinical and clinical studies with the sub-type selective Aurora inhibitors could help bring them to the market for the treatment of cancer.

  2. Exploiting Chemical Libraries, Structure, and Genomics in the Search for Kinase Inhibitors

    NARCIS (Netherlands)

    Gray, Nathanael S.; Wodicka, Lisa; Thunnissen, Andy-Mark W.H.; Norman, Thea C.; Kwon, Soojin; Espinoza, F. Hernan; Morgan, David O.; Barnes, Georjana; LeClerc, Sophie; Meijer, Laurent; Kim, Sung-Hou; Lockhart, David J.; Schultz, Peter G.

    1998-01-01

    Selective protein kinase inhibitors were developed on the basis of the unexpected binding mode of 2,6,9-trisubstituted purines to the adenosine triphosphate-binding site of the human cyclin-dependent kinase 2 (CDK2). By iterating chemical library synthesis and biological screening, potent inhibitors

  3. Rational Design of Rho Protein Inhibitors

    National Research Council Canada - National Science Library

    Rojas, Rafael J

    2006-01-01

    Rho GTPases are molecular switches that fluctuate between on and off states. When active, these proteins function to remodel the actin cytoskeleton by interacting with a number of downstream effector molecules...

  4. Rational Design of Rho Protein Inhibitors

    National Research Council Canada - National Science Library

    Rojas, Rafael J

    2005-01-01

    Rho GTPases are molecular switches that fluctuate between on and off states. When active, these proteins function to remodel the actin cytoskeleton by interacting with a number of downstream effector molecules...

  5. A cGMP kinase mutant with increased sensitivity to the protein kinase inhibitor peptide PKI(5-24).

    Science.gov (United States)

    Ruth, P; Kamm, S; Nau, U; Pfeifer, A; Hofmann, F

    1996-01-01

    Synthetic peptides corresponding to the active domain of the heat-stable inhibitor protein PKI are very potent inhibitors of cAMP-dependent protein kinase, but are extremely weak inhibitors of cGMP-dependent protein kinase. In this study, we tried to confer PKI sensitivity to cGMP kinase by site-directed mutagenesis. The molecular requirements for high affinity inhibition by PKI were deduced from the crystal structure of the cAMP kinase/PKI complex. A prominent site of interaction are residues Tyr235 and Phe239 in the catalytic subunit, which from a sandwich-like structure with Phe10 of the PKI(5-24) peptide. To increase the sensitivity for PKI, the cGMP kinase codons at the corresponding sites, Ser555 and Ser559, were changed to Tyr and Phe. The mutant cGMP kinase was stimulated half maximally by cGMP at 3-fold higher concentrations (240 nM) than the wild type (77 nM). Wild type and mutant cGMP kinase did not differ significantly in their Km and Vmax for three different substrate peptides. The PKI(5-24) peptide inhibited phosphotransferase activity of the mutant cGMP kinase with higher potency than that of wild type, with Ki values of 42 +/- .3 microM and 160 +/- .7 microM, respectively. The increased affinity of the mutant cGMP kinase was specific for the PKI(5-24) peptide. Mutation of the essential Phe10 in the PKI(5-24) sequence to an Ala yielded a peptide that inhibited mutant and wild type cGMP kinase with similar potency, with Ki values of 160 +/- 11 and 169 +/- 27 microM, respectively. These results suggest that the mutations Ser555Tyr and Ser559Phe are required, but not sufficient, for high affinity inhibition of cGMP kinase by PKI.

  6. Deoxypodophyllotoxin suppresses tumor vasculature in HUVECs by promoting cytoskeleton remodeling through LKB1-AMPK dependent Rho A activatio.

    Science.gov (United States)

    Wang, Yurong; Wang, Bin; Guerram, Mounia; Sun, Li; Shi, Wei; Tian, Chongchong; Zhu, Xiong; Jiang, Zhenzhou; Zhang, Luyong

    2015-10-06

    Angiogenesis plays a critical role in the growth and metastasis of tumors, which makes it an attractive target for anti-tumor drug development. Deoxypodophyllotoxin (DPT), a natural product isolated from Anthriscus sylvestris, inhibits cell proliferation and migration in various cancer cell types. Our previous studies indicate that DPT possesses both anti-angiogenic and vascular-disrupting activities. Although the RhoA/ RhoA kinase (ROCK) signaling pathway is implicated in DPT-stimulated cytoskeleton remodeling and tumor vasculature suppressing, the detailed mechanisms by which DPT mediates these effects are poorly understood. In the current study, we found that DPT promotes cytoskeleton remodeling in human umbilical vein endothelial cells (HUVECs) via stimulation of AMP-activated protein kinase (AMPK) and that this effect is abolished by either treatment with a selective AMPK inhibitor or knockdown. Moreover, the cellular levels of LKB1, a kinase upstream of AMPK, were enhanced following DPT exposure. DPT-induced activation of AMPK in tumor vasculature effect was also verified by transgenic zebrafish (VEGFR2:GFP), Matrigel plug assay, and xenograft model in nude mice. The present findings may lay the groundwork for a novel therapeutic approach in treating cancer.

  7. Rho-kinase signaling controls nucleocytoplasmic shuttling of class IIa Histone Deacetylase (HDAC7) and transcriptional activation of orphan nuclear receptor NR4A1

    Energy Technology Data Exchange (ETDEWEB)

    Compagnucci, Claudia; Barresi, Sabina [Unit of Molecular Medicine for Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Children’s Hospital, IRCCS, Rome (Italy); Petrini, Stefania [Research Laboratories, Confocal Microscopy Core Facility, Bambino Gesù Children’s Hospital, IRCCS, Rome (Italy); Bertini, Enrico [Unit of Molecular Medicine for Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Children’s Hospital, IRCCS, Rome (Italy); Zanni, Ginevra, E-mail: ginevra.zanni@opbg.net [Unit of Molecular Medicine for Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Children’s Hospital, IRCCS, Rome (Italy)

    2015-04-03

    Rho-kinase (ROCK) has been well documented to play a key role in RhoA-induced actin remodeling. ROCK activation results in myosin light chain (MLC) phosphorylation either by direct action on MLC kinase (MLCK) or by inhibition of MLC phosphatase (MLCP), modulating actin–myosin contraction. We found that inhibition of the ROCK pathway in induced pluripotent stem cells, leads to nuclear export of HDAC7 and transcriptional activation of the orphan nuclear receptor NR4A1 while in cells with constitutive ROCK hyperactivity due to loss of function of the RhoGTPase activating protein Oligophrenin-1 (OPHN1), the orphan nuclear receptor NR4A1 is downregulated. Our study identify a new target of ROCK signaling via myosin phosphatase subunit (MYPT1) and Histone Deacetylase (HDAC7) at the nuclear level and provide new insights in the cellular functions of ROCK. - Highlights: • ROCK regulates nucleocytoplasmic shuttling of HDAC7 via phosphorylation of MYPT1. • Nuclear export of HDAC7 and upregulation of NR4A1 occurs with low ROCK activity. • High levels of ROCK activity due to OPHN1 loss of function downregulate NR4A1.

  8. The Azaindole Framework in the Design of Kinase Inhibitors

    Directory of Open Access Journals (Sweden)

    Jean-Yves Mérour

    2014-11-01

    Full Text Available This review article illustrates the growing use of azaindole derivatives as kinase inhibitors and their contribution to drug discovery and innovation. The different protein kinases which have served as targets and the known molecules which have emerged from medicinal chemistry and Fragment-Based Drug Discovery (FBDD programs are presented. The various synthetic routes used to access these compounds and the chemical pathways leading to their synthesis are also discussed. An analysis of their mode of binding based on X-ray crystallography data gives structural insights for the design of more potent and selective inhibitors.

  9. Substance P induces rapid and transient membrane blebbing in U373MG cells in a p21-activated kinase-dependent manner.

    Directory of Open Access Journals (Sweden)

    John Meshki

    Full Text Available U373MG astrocytoma cells endogenously express the full-length neurokinin 1 receptor (NK1R. Substance P (SP, the natural ligand for NK1R, triggers rapid and transient membrane blebbing and we report that these morphological changes have different dynamics and intracellular signaling as compared to the changes that we have previously described in HEK293-NK1R cells. In both cell lines, the SP-induced morphological changes are Gq-independent, and they require the Rho, Rho-associated coiled-coil kinase (ROCK signaling pathway. Using confocal microscopy we have demonstrated that tubulin is phosphorylated subsequent to cell stimulation with SP and that tubulin accumulates inside the blebs. Colchicine, a tubulin polymerization inhibitor, blocked SP-induced blebbing in U373MG but not in HEK293-NK1R cells. Although p21-activated kinase (PAK is expressed in both cell lines, SP induced rapid phosphorylation of PAK in U373MG, but failed to phosphorylate PAK in HEK293-NK1R cells. The cell-permeable Rho inhibitor C3 transferase inhibited SP-induced PAK phosphorylation, but the ROCK inhibitor Y27632 had no effect on PAK phosphorylation, suggesting that Rho activates PAK in a ROCK-independent manner. Our study demonstrates that SP triggers rapid changes in cell morphology mediated by distinct intracellular signaling mechanisms in U373MG versus HEK293-NK1R cells.

  10. Small-molecule kinase inhibitors: an analysis of FDA-approved drugs

    DEFF Research Database (Denmark)

    Wu, Peng; Nielsen, Thomas Eiland; Clausen, Mads Hartvig

    2016-01-01

    Small-molecule kinase inhibitors (SMKIs), 28 of which are approved by the US Food and Drug Administration (FDA), have been actively pursued as promising targeted therapeutics. Here, we assess the key structural and physicochemical properties, target selectivity and mechanism of function, and ther......Small-molecule kinase inhibitors (SMKIs), 28 of which are approved by the US Food and Drug Administration (FDA), have been actively pursued as promising targeted therapeutics. Here, we assess the key structural and physicochemical properties, target selectivity and mechanism of function...

  11. Mini Screening of Kinase Inhibitors Affecting Period-length of Mammalian Cellular Circadian Clock

    International Nuclear Information System (INIS)

    Yagita, Kazuhiro; Yamanaka, Iori; Koinuma, Satoshi; Shigeyoshi, Yasufumi; Uchiyama, Yasuo

    2009-01-01

    In mammalian circadian rhythms, the transcriptional-translational feedback loop (TTFL) consisting of a set of clock genes is believed to elicit the circadian clock oscillation. The TTFL model explains that the accumulation and degradation of mPER and mCRY proteins control the period-length (tau) of the circadian clock. Although recent studies revealed that the Casein Kinase Iεδ (CKIεδ) regurates the phosphorylation of mPER proteins and the circadian period-length, other kinases are also likely to contribute the phosphorylation of mPER. Here, we performed small scale screening using 84 chemical compounds known as kinase inhibitors to identify candidates possibly affecting the circadian period-length in mammalian cells. Screening by this high-throughput real-time bioluminescence monitoring system revealed that the several chemical compounds apparently lengthened the cellular circadian clock oscillation. These compounds are known as inhibitors against kinases such as Casein Kinase II (CKII), PI3-kinase (PI3K) and c-Jun N-terminal Kinase (JNK) in addition to CKIεδ. Although these kinase inhibitors may have some non-specific effects on other factors, our mini screening identified new candidates contributing to period-length control in mammalian cells

  12. Molecular Mechanism of Selectivity among G Protein-Coupled Receptor Kinase 2 Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Thal, David M.; Yeow, Raymond Y.; Schoenau, Christian; Huber, Jochen; Tesmer, John J.G. (Sanofi); (Michigan)

    2012-07-11

    G protein-coupled receptors (GPCRs) are key regulators of cell physiology and control processes ranging from glucose homeostasis to contractility of the heart. A major mechanism for the desensitization of activated GPCRs is their phosphorylation by GPCR kinases (GRKs). Overexpression of GRK2 is strongly linked to heart failure, and GRK2 has long been considered a pharmaceutical target for the treatment of cardiovascular disease. Several lead compounds developed by Takeda Pharmaceuticals show high selectivity for GRK2 and therapeutic potential for the treatment of heart failure. To understand how these drugs achieve their selectivity, we determined crystal structures of the bovine GRK2-G{beta}{gamma} complex in the presence of two of these inhibitors. Comparison with the apoGRK2-G{beta}{gamma} structure demonstrates that the compounds bind in the kinase active site in a manner similar to that of the AGC kinase inhibitor balanol. Both balanol and the Takeda compounds induce a slight closure of the kinase domain, the degree of which correlates with the potencies of the inhibitors. Based on our crystal structures and homology modeling, we identified five amino acids surrounding the inhibitor binding site that we hypothesized could contribute to inhibitor selectivity. However, our results indicate that these residues are not major determinants of selectivity among GRK subfamilies. Rather, selectivity is achieved by the stabilization of a unique inactive conformation of the GRK2 kinase domain.

  13. Methods Of Using Chemical Libraries To Search For New Kinase Inhibitors

    Science.gov (United States)

    Gray, Nathanael S. , Schultz, Peter , Wodicka, Lisa , Meijer, Laurent , Lockhart, David J.

    2003-06-03

    The generation of selective inhibitors for specific protein kinases would provide new tools for analyzing signal transduction pathways and possibly new therapeutic agents. We have invented an approach to the development of selective protein kinase inhibitors based on the unexpected binding mode of 2,6,9-trisubstituted purines to the ATP binding site of human CDK2. The most potent inhibitor, purvalanol B (IC.sub.50 =6 nM), binds with a 30-fold greater affinity than the known CDK2 inhibitor, flavopiridol. The cellular effects of this class of compounds were examined and compared to those of flavopiridol by monitoring changes in mRNA expression levels for all genes in treated cells of Saccharomyces cerevisiae using high-density oligonucleotide probe arrays.

  14. Fluorescent Inhibitors as Tools To Characterize Enzymes: Case Study of the Lipid Kinase Phosphatidylinositol 4-Kinase IIIβ (PI4KB).

    Science.gov (United States)

    Humpolickova, Jana; Mejdrová, Ivana; Matousova, Marika; Nencka, Radim; Boura, Evzen

    2017-01-12

    The lipid kinase phosphatidylinositol 4-kinase IIIβ (PI4KB) is an essential host factor for many positive-sense single-stranded RNA (+RNA) viruses including human pathogens hepatitis C virus (HCV), Severe acute respiratory syndrome (SARS), coxsackie viruses, and rhinoviruses. Inhibitors of PI4KB are considered to be potential broad-spectrum virostatics, and it is therefore critical to develop a biochemical understanding of the kinase. Here, we present highly potent and selective fluorescent inhibitors that we show to be useful chemical biology tools especially in determination of dissociation constants. Moreover, we show that the coumarin-labeled inhibitor can be used to image PI4KB in cells using fluorescence-lifetime imaging microscopy (FLIM) microscopy.

  15. Anesthetic Sevoflurane Causes Rho-Dependent Filopodial Shortening in Mouse Neurons.

    Directory of Open Access Journals (Sweden)

    Jeffrey H Zimering

    Full Text Available Early postnatal anesthesia causes long-lasting learning and memory impairment in rodents, however, evidence for a specific neurotoxic effect on early synaptogenesis has not been demonstrated. Drebrin A is an actin binding protein whose localization in dendritic protrusions serves an important role in dendritic spine morphogenesis, and is a marker for early synaptogenesis. We therefore set out to investigate whether clinically-relevant concentrations of anesthetic sevoflurane, widely- used in infants and children, alters dendritic morphology in cultured fetal day 16 mouse hippocampal neurons. After 7 days in vitro, mouse hippocampal neurons were exposed to four hours of 3% sevoflurane in 95% air/5% CO2 or control condition (95% air/5% CO2. Neurons were fixed in 4% paraformaldehyde and stained with Alexa Fluor555-Phalloidin, and/or rabbit anti-mouse drebrin A/E antibodies which permitted subcellular localization of filamentous (F-actin and/or drebrin immunoreactivity, respectively. Sevoflurane caused acute significant length-shortening in filopodia and thin dendritic spines in days-in-vitro 7 neurons, an effect which was completely rescued by co-incubating neurons with ten micromolar concentrations of the selective Rho kinase inhibitor Y27632. Filopodia and thin spine recovered in length two days after sevoflurane exposure. Yet cluster-type filopodia (a precursor to synaptic filopodia were persistently significantly decreased in number on day-in-vitro 9, in part owing to preferential localization of drebrin immunoreactivity to dendritic shafts versus filopodial stalks. These data suggest that sevoflurane induces F-actin depolymerization leading to acute, reversible length-shortening in dendritic protrusions through a mechanism involving (in part activation of RhoA/Rho kinase signaling and impairs localization of drebrin A to filopodia required for early excitatory synapse formation.

  16. Promiscuity and selectivity of small-molecule inhibitors across TAM receptor tyrosine kinases in pediatric leukemia.

    Science.gov (United States)

    Liu, Mao-Hua; Chen, Shi-Bing; Yu, Juan; Liu, Cheng-Jun; Zhang, Xiao-Jing

    2017-08-01

    The TAM receptor tyrosine kinase family member Mer has been recognized as an attractive therapeutic target for pediatric leukemia. Beside Mer the family contains other two kinases, namely, Tyro3 and Axl, which are highly homologues with Mer and thus most existing small-molecule inhibitors show moderate or high promiscuity across the three kinases. Here, the structural basis and energetic property of selective binding of small-molecule inhibitors to the three kinases were investigated at molecular level. It is found that the selectivity is primarily determined by the size, shape and configuration of kinase's ATP-binding site; the Mer and Axl possess a small, closed active pocket as compared to the bulky, open pocket of Tyro3. The location and conformation of active-site residues of Mer and Axl are highly consistent, suggesting that small-molecule inhibitors generally have a low Mer-over-Axl selectivity and a high Mer-over-Tyro3 selectivity. We demonstrated that the difference in ATP binding potency to the three kinases is also responsible for inhibitor selectivity. We also found that the long-range interactions and allosteric effect arising from rest of the kinase's active site can indirectly influence inhibitor binding and selectivity. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Screening of protein kinase inhibitors identifies PKC inhibitors as inhibitors of osteoclastic acid secretion and bone resorption

    Directory of Open Access Journals (Sweden)

    Boutin Jean A

    2010-10-01

    Full Text Available Abstract Background Bone resorption is initiated by osteoclastic acidification of the resorption lacunae. This process is mediated by secretion of protons through the V-ATPase and chloride through the chloride antiporter ClC-7. To shed light on the intracellular signalling controlling extracellular acidification, we screened a protein kinase inhibitor library in human osteoclasts. Methods Human osteoclasts were generated from CD14+ monocytes. The effect of different kinase inhibitors on lysosomal acidification in human osteoclasts was investigated using acridine orange for different incubation times (45 minutes, 4 and 24 hours. The inhibitors were tested in an acid influx assay using microsomes isolated from human osteoclasts. Bone resorption by human osteoclasts on bone slices was measured by calcium release. Cell viability was measured using AlamarBlue. Results Of the 51 compounds investigated only few inhibitors were positive in both acidification and resorption assays. Rottlerin, GF109203X, Hypericin and Ro31-8220 inhibited acid influx in microsomes and bone resorption, while Sphingosine and Palmitoyl-DL-carnitine-Cl showed low levels of inhibition. Rottlerin inhibited lysosomal acidification in human osteoclasts potently. Conclusions In conclusion, a group of inhibitors all indicated to inhibit PKC reduced acidification in human osteoclasts, and thereby bone resorption, indicating that acid secretion by osteoclasts may be specifically regulated by PKC in osteoclasts.

  18. The Axl kinase domain in complex with a macrocyclic inhibitor offers first structural insights into an active TAM receptor kinase.

    Science.gov (United States)

    Gajiwala, Ketan S; Grodsky, Neil; Bolaños, Ben; Feng, Junli; Ferre, RoseAnn; Timofeevski, Sergei; Xu, Meirong; Murray, Brion W; Johnson, Ted W; Stewart, Al

    2017-09-22

    The receptor tyrosine kinase family consisting of Tyro3, Axl, and Mer (TAM) is one of the most recently identified receptor tyrosine kinase families. TAM receptors are up-regulated postnatally and maintained at high levels in adults. They all play an important role in immunity, but Axl has also been implicated in cancer and therefore is a target in the discovery and development of novel therapeutics. However, of the three members of the TAM family, the Axl kinase domain is the only one that has so far eluded structure determination. To this end, using differential scanning fluorimetry and hydrogen-deuterium exchange mass spectrometry, we show here that a lower stability and greater dynamic nature of the Axl kinase domain may account for its poor crystallizability. We present the first structural characterization of the Axl kinase domain in complex with a small-molecule macrocyclic inhibitor. The Axl crystal structure revealed two distinct conformational states of the enzyme, providing a first glimpse of what an active TAM receptor kinase may look like and suggesting a potential role for the juxtamembrane region in enzyme activity. We noted that the ATP/inhibitor-binding sites of the TAM members closely resemble each other, posing a challenge for the design of a selective inhibitor. We propose that the differences in the conformational dynamics among the TAM family members could potentially be exploited to achieve inhibitor selectivity for targeted receptors. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Rho/ROCK signaling in regulation of corneal epithelial cell cycle progression.

    Science.gov (United States)

    Chen, Jian; Guerriero, Emily; Lathrop, Kira; SundarRaj, Nirmala

    2008-01-01

    The authors' previous study showed that the expression of a Rho-associated serine/threonine kinase (ROCK) is regulated during cell cycle progression in corneal epithelial cells. The present study was conducted to determine whether and how Rho/ROCK signaling regulates cell cycle progression. Rabbit corneal epithelial cells (RCECs) in culture were arrested in the G(0) phase of the cell cycle by serum deprivation and then allowed to re-enter the cell cycle in the presence or absence of the ROCK inhibitor (Y27632) in serum-supplemented medium. The number of cells in the S phase, the relative levels of specific cyclins and CDKs and their intracellular distribution, and the relative levels of mRNAs were determined by BrdU labeling, Western blot and immunocytochemical analyses, and real-time RT-PCR, respectively. ROCK inhibition delayed the progression of G(1) to S phase and led to a decrease in the number of RCECs entering the S phase between 12 and 24 hours from 31.5% +/- 4.5% to 8.1% +/- 2.6%. During the cell cycle progression, protein and mRNA levels of cyclin-D1 and -D3 and cyclin-dependent kinases CDK4 and CDK6 were significantly lower, whereas the protein levels of the CDK inhibitor p27(Kip1) were higher in ROCK-inhibited cells. Intracellular mRNA or protein levels of cyclin-E and protein levels of CDK2 were not significantly affected, but their nuclear translocation was delayed by ROCK inhibition. ROCK signaling is involved in cell cycle progression in RCECs, possibly by upregulation of cyclin-D1 and -D3 and CDK4, -6, and -2; nuclear translocation of CDK2 and cyclin-E; and downregulation of p27(Kip1).

  20. A dual-specificity isoform of the protein kinase inhibitor PKI produced by alternate gene splicing.

    Science.gov (United States)

    Kumar, Priyadarsini; Walsh, Donal A

    2002-03-15

    We have previously shown that the protein kinase inhibitor beta (PKIbeta) form of the cAMP-dependent protein kinase inhibitor exists in multiple isoforms, some of which are specific inhibitors of the cAMP-dependent protein kinase, whereas others also inhibit the cGMP-dependent enzyme [Kumar, Van Patten and Walsh (1997), J. Biol. Chem. 272, 20011-20020]. We have now demonstrated that the switch from a cAMP-dependent protein kinase (PKA)-specific inhibitor to one with dual specificity arises as a consequence of alternate gene splicing. We have confirmed using bacterially produced pure protein that a single inhibitor species has dual specificity for both PKA and cGMP-dependent protein kinase (PKG), inhibiting each with very high and closely similar inhibitory potencies. The gene splicing converted a protein with 70 amino acids into one of 109 amino acids, and did not change the inhibitory potency to PKA, but changed it from a protein that had no detectable PKG inhibitory activity to one that now inhibited PKG in the nanomolar range.

  1. Tyrosine kinase, aurora kinase and leucine aminopeptidase as attractive drug targets in anticancer therapy - characterisation of their inhibitors.

    Science.gov (United States)

    Ziemska, Joanna; Solecka, Jolanta

    Cancers are the leading cause of deaths all over the world. Available anticancer agents used in clinics exhibit low therapeutic index and usually high toxicity. Wide spreading drug resistance of cancer cells induce a demanding need to search for new drug targets. Currently, many on-going studies on novel compounds with potent anticancer activity, high selectivity as well as new modes of action are conducted. In this work, we describe in details three enzyme groups, which are at present of extensive interest to medical researchers and pharmaceutical companies. These include receptor tyrosine kinases (e.g. EGFR enzymes) and non-receptor tyrosine kinases (Src enzymes), type A, B and C Aurora kinases and aminopeptidases, especially leucine aminopeptidase. We discuss classification of these enzymes, biochemistry as well as their role in the cell cycle under normal conditions and during cancerogenesis. Further on, the work describes enzyme inhibitors that are under in vitro, preclinical, clinical studies as well as drugs available on the market. Both, chemical structures of discovered inhibitors and the role of chemical moieties in novel drug design are discussed. Described enzymes play essential role in cell cycle, especially in mitosis (Aurora kinases), cell differentiation, growth and apoptosis (tyrosine kinases) as well as G1/S transition (leucine aminopeptidase). In cancer cells, they are overexpressed and only their inhibition may stop tumor progression. This review presents the clinical outcomes of selected inhibitors and argues the safety of drug usage in human volunteers. Clinical studies of EGFR and Src kinase inhibitors in different tumors clearly show the need for molecular selection of patients (to those with mutations in genes coding EGFR and Src) to achieve positive clinical response. Current data indicates the great necessity for new anticancer treatment and actions to limit off-target activity.

  2. Recent advances in the discovery of small molecule c-Met Kinase inhibitors.

    Science.gov (United States)

    Parikh, Palak K; Ghate, Manjunath D

    2018-01-01

    c-Met is a prototype member of a subfamily of heterodimeric receptor tyrosine kinases (RTKs) and is the receptor for hepatocyte growth factor (HGF). Binding of HGF to its receptor c-Met, initiates a wide range of cellular signalling, including those involved in proliferation, motility, migration and invasion. Importantly, dysregulated HGF/c-Met signalling is a driving factor for numerous malignancies and promotes tumour growth, invasion, dissemination and/or angiogenesis. Dysregulated HGF/c-Met signalling has also been associated with poor clinical outcomes and resistance acquisition to some approved targeted therapies. Thus, c-Met kinase has emerged as a promising target for cancer drug development. Different therapeutic approaches targeting the HGF/c-Met signalling pathway are under development for targeted cancer therapy, among which small molecule inhibitors of c-Met kinase constitute the largest effort within the pharmaceutical industry. The review is an effort to summarize recent advancements in medicinal chemistry development of small molecule c-Met kinase inhibitors as potential anti-cancer agents which would certainly help future researchers to bring further developments in the discovery of small molecule c-Met kinase inhibitors. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Structural Mechanism of the Pan-BCR-ABL Inhibitor Ponatinib (AP24534): Lessons for Overcoming Kinase Inhibitor Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Tianjun; Commodore, Lois; Huang, Wei-Sheng; Wang, Yihan; Thomas, Mathew; Keats, Jeff; Xu, Qihong; Rivera, Victor M.; Shakespeare, William C.; Clackson, Tim; Dalgarno, David C.; Zhu, Xiaotian (ARIAD)

    2012-01-20

    The BCR-ABL inhibitor imatinib has revolutionized the treatment of chronic myeloid leukemia. However, drug resistance caused by kinase domain mutations has necessitated the development of new mutation-resistant inhibitors, most recently against the T315I gatekeeper residue mutation. Ponatinib (AP24534) inhibits both native and mutant BCR-ABL, including T315I, acting as a pan-BCR-ABL inhibitor. Here, we undertook a combined crystallographic and structure-activity relationship analysis on ponatinib to understand this unique profile. While the ethynyl linker is a key inhibitor functionality that interacts with the gatekeeper, virtually all other components of ponatinib play an essential role in its T315I inhibitory activity. The extensive network of optimized molecular contacts found in the DFG-out binding mode leads to high potency and renders binding less susceptible to disruption by single point mutations. The inhibitory mechanism exemplified by ponatinib may have broad relevance to designing inhibitors against other kinases with mutated gatekeeper residues.

  4. Activation loop targeting strategy for design of receptor-interacting protein kinase 2 (RIPK2) inhibitors.

    Science.gov (United States)

    Suebsuwong, Chalada; Pinkas, Daniel M; Ray, Soumya S; Bufton, Joshua C; Dai, Bing; Bullock, Alex N; Degterev, Alexei; Cuny, Gregory D

    2018-02-15

    Development of selective kinase inhibitors remains a challenge due to considerable amino acid sequence similarity among family members particularly in the ATP binding site. Targeting the activation loop might offer improved inhibitor selectivity since this region of kinases is less conserved. However, the strategy presents difficulties due to activation loop flexibility. Herein, we report the design of receptor-interacting protein kinase 2 (RIPK2) inhibitors based on pan-kinase inhibitor regorafenib that aim to engage basic activation loop residues Lys169 or Arg171. We report development of CSR35 that displayed >10-fold selective inhibition of RIPK2 versus VEGFR2, the target of regorafenib. A co-crystal structure of CSR35 with RIPK2 revealed a resolved activation loop with an ionic interaction between the carboxylic acid installed in the inhibitor and the side-chain of Lys169. Our data provides principle feasibility of developing activation loop targeting type II inhibitors as a complementary strategy for achieving improved selectivity. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  5. Increased diacylglycerol kinase ζ expression in human metastatic colon cancer cells augments Rho GTPase activity and contributes to enhanced invasion

    International Nuclear Information System (INIS)

    Cai, Kun; Mulatz, Kirk; Ard, Ryan; Nguyen, Thanh; Gee, Stephen H

    2014-01-01

    Unraveling the signaling pathways responsible for the establishment of a metastatic phenotype in carcinoma cells is critically important for understanding the pathology of cancer. The acquisition of cell motility is a key property of metastatic tumor cells and is a prerequisite for invasion. Rho GTPases regulate actin cytoskeleton reorganization and the cellular responses required for cell motility and invasion. Diacylglycerol kinase ζ (DGKζ), an enzyme that phosphorylates diacylglycerol to yield phosphatidic acid, regulates the activity of the Rho GTPases Rac1 and RhoA. DGKζ mRNA is highly expressed in several different colon cancer cell lines, as well as in colon cancer tissue relative to normal colonic epithelium, and thus may contribute to the metastatic process. To investigate potential roles of DGKζ in cancer metastasis, a cellular, isogenic model of human colorectal cancer metastatic transition was used. DGKζ protein levels, Rac1 and RhoA activity, and PAK phosphorylation were measured in the non-metastatic SW480 adenocarcinoma cell line and its highly metastatic variant, the SW620 line. The effect of DGKζ silencing on Rho GTPase activity and invasion through Matrigel-coated Transwell inserts was studied in SW620 cells. Invasiveness was also measured in PC-3 prostate cancer and MDA-MB-231 breast cancer cells depleted of DGKζ. DGKζ protein levels were elevated approximately 3-fold in SW620 cells compared to SW480 cells. There was a concomitant increase in active Rac1 in SW620 cells, as well as substantial increases in the expression and phosphorylation of the Rac1 effector PAK1. Similarly, RhoA activity and expression were increased in SW620 cells. Knockdown of DGKζ expression in SW620 cells by shRNA-mediated silencing significantly reduced Rac1 and RhoA activity and attenuated the invasiveness of SW620 cells in vitro. DGKζ silencing in highly metastatic MDA-MB-231 breast cancer cells and PC-3 prostate cancer cells also significantly attenuated

  6. Aurora kinase inhibitors: Progress towards the clinic

    Czech Academy of Sciences Publication Activity Database

    Kollareddy, M.; Zheleva, D.; Dzubak, P.; Brahmkshatriya, Pathik; Lepšík, Martin; Hajduch, M.

    2012-01-01

    Roč. 30, č. 6 (2012), s. 2411-2432 ISSN 0167-6997 Grant - others:GA ČR(CZ) GA301/08/1649; GA ČR(CZ) GD303/09/H048 Program:GA; GD Institutional research plan: CEZ:AV0Z40550506 Keywords : Aurora kinases * cancer * inhibitors Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.498, year: 2012

  7. Cyclin-dependent kinase inhibitors as anticancer drugs

    Czech Academy of Sciences Publication Activity Database

    Kryštof, Vladimír; Uldrijan, S.

    2010-01-01

    Roč. 11, č. 3 (2010), s. 291-302 ISSN 1389-4501 R&D Projects: GA ČR GA204/08/0511; GA ČR GA301/08/1649; GA MŠk(CZ) LC06077 Institutional research plan: CEZ:AV0Z50380511 Keywords : CDK * protein kinase * inhibitor Subject RIV: CE - Biochemistry Impact factor: 3.061, year: 2010

  8. Novel arylazopyrazole inhibitors of cyclin-dependent kinases

    Czech Academy of Sciences Publication Activity Database

    Jorda, Radek; Schütznerová, E.; Cankař, P.; Brychtová, Veronika; Navrátilová, Jana; Kryštof, Vladimír

    2015-01-01

    Roč. 23, č. 9 (2015), s. 1975-1981 ISSN 0968-0896 R&D Projects: GA ČR GAP305/12/0783; GA ČR GA14-19590S; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Cyclin-dependent kinases * Inhibitor * Cell cycle Subject RIV: CE - Biochemistry Impact factor: 2.923, year: 2015

  9. Inhibition of the Rho/ROCK pathway prevents neuronal degeneration in vitro and in vivo following methylmercury exposure

    International Nuclear Information System (INIS)

    Fujimura, Masatake; Usuki, Fusako; Kawamura, Miwako; Izumo, Shuji

    2011-01-01

    Methylmercury (MeHg) is an environmental neurotoxicant which induces neuropathological changes in both the central nervous and peripheral sensory nervous systems. Our recent study demonstrated that down-regulation of Ras-related C3 botulinum toxin substrate 1 (Rac1), which is known to promote neuritic extension, preceded MeHg-induced damage in cultured cortical neurons, suggesting that MeHg-mediated axonal degeneration is due to the disturbance of neuritic extension. Therefore we hypothesized that MeHg-induced axonal degeneration might be caused by neuritic extension/retraction incoordination. This idea brought our attention to the Ras homolog gene (Rho)/Rho-associated coiled coil-forming protein kinase (ROCK) pathway because it has been known to be associated with the development of axon and apoptotic neuronal cell death. Here we show that inhibition of the Rho/ROCK pathway prevents MeHg-intoxication both in vitro and in vivo. A Rho inhibitor, C3 toxin, and 2 ROCK inhibitors, Fasudil and Y-27632, significantly protected against MeHg-induced axonal degeneration and apoptotic neuronal cell death in cultured cortical neuronal cells exposed to 100 nM MeHg for 3 days. Furthermore, Fasudil partially prevented the loss of large pale neurons in dorsal root ganglia, axonal degeneration in dorsal spinal root nerves, and vacuolar degeneration in the dorsal columns of the spinal cord in MeHg-intoxicated model rats (20 ppm MeHg in drinking water for 28 days). Hind limb crossing sign, a characteristic MeHg-intoxicated sign, was significantly suppressed in this model. The results suggest that inhibition of the Rho/ROCK pathway rescues MeHg-mediated neuritic extension/retraction incoordination and is effective for the prevention of MeHg-induced axonal degeneration and apoptotic neuronal cell death.

  10. RhoA/ROCK downregulates FPR2-mediated NADPH oxidase activation in mouse bone marrow granulocytes.

    Science.gov (United States)

    Filina, Julia V; Gabdoulkhakova, Aida G; Safronova, Valentina G

    2014-10-01

    Polymorphonuclear neutrophils (PMNs) express the high and low affinity receptors to formylated peptides (mFPR1 and mFPR2 in mice, accordingly). RhoA/ROCK (Rho activated kinase) pathway is crucial for cell motility and oxidase activity regulated via FPRs. There are contradictory data on RhoA-mediated regulation of NADPH oxidase activity in phagocytes. We have shown divergent Rho GTPases signaling via mFPR1 and mFPR2 to NADPH oxidase in PMNs from inflammatory site. The present study was aimed to find out the role of RhoA/ROCK in the respiratory burst activated via mFPR1 and mFPR2 in the bone marrow PMNs. Different kinetics of RhoA activation were detected with 0.1μM fMLF and 1μM WKYMVM operating via mFPR1 and mFPR2, accordingly. RhoA was translocated in fMLF-activated cells towards the cell center and juxtamembrane space versus uniform allocation in the resting cells. Specific inhibition of RhoA by CT04, Rho inhibitor I, weakly depressed the respiratory burst induced via mFPR1, but significantly increased the one induced via mFPR2. Inhibition of ROCK, the main effector of RhoA, by Y27632 led to the same effect on the respiratory burst. Regulation of mFPR2-induced respiratory response by ROCK was impossible under the cytoskeleton disruption by cytochalasin D, whereas it persisted in the case of mFPR1 activation. Thus we suggest RhoA to be one of the regulatory and signal transduction components in the respiratory burst through FPRs in the mouse bone marrow PMNs. Both mFPR1 and mFPR2 binding with a ligand trigger the activation of RhoA. FPR1 signaling through RhoA/ROCK increases NADPH-oxidase activity. But in FPR2 action RhoA/ROCK together with cytoskeleton-linked systems down-regulates NADPH-oxidase. This mechanism could restrain the reactive oxygen species dependent damage of own tissues during the chemotaxis of PMNs and in the resting cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. BCR-ABL1 tyrosine kinase inhibitors for the treatment of chronic myeloid leukemia.

    Science.gov (United States)

    Cuellar, Sandra; Vozniak, Michael; Rhodes, Jill; Forcello, Nicholas; Olszta, Daniel

    2017-01-01

    The management of chronic myeloid leukemia with BCR-ABL1 tyrosine kinase inhibitors has evolved chronic myeloid leukemia into a chronic, manageable disease. A patient-centered approach is important for the appropriate management of chronic myeloid leukemia and optimization of long-term treatment outcomes. The pharmacist plays a key role in treatment selection, monitoring drug-drug interactions, identification and management of adverse events, and educating patients on adherence. The combination of tyrosine kinase inhibitors with unique safety profiles and individual patients with unique medical histories can make managing treatment difficult. This review will provide up-to-date information regarding tyrosine kinase inhibitor-based treatment of patients with chronic myeloid leukemia. Management strategies for adverse events and considerations for drug-drug interactions will not only vary among patients but also across tyrosine kinase inhibitors. Drug-drug interactions can be mild to severe. In instances where co-administration of concomitant medications cannot be avoided, it is critical to understand how drug levels are impacted and how subsequent dose modifications ensure therapeutic drug levels are maintained. An important component of patient-centered management of chronic myeloid leukemia also includes educating patients on the significance of early and regular monitoring of therapeutic milestones, emphasizing the importance of adhering to treatment in achieving these targets, and appropriately modifying treatment if these clinical goals are not being met. Overall, staying apprised of current research, utilizing the close pharmacist-patient relationship, and having regular interactions with patients, will help achieve successful long-term treatment of chronic myeloid leukemia in the age of BCR-ABL1 tyrosine kinase inhibitors.

  12. Phosphatidylinositol 3-Kinase (PI3K) and phosphatidylinositol 3-kinase-related kinase (PIKK) inhibitors: importance of the morpholine ring

    Czech Academy of Sciences Publication Activity Database

    Andrs, M.; Kobarecny, J.; Jun, D.; Hodný, Zdeněk; Bartek, Jiří; Kuca, K.

    2015-01-01

    Roč. 58, č. 1 (2015), s. 41-71 ISSN 0022-2623 R&D Projects: GA MŠk(CZ) CZ.1.07/2.3.00/30.0044 Grant - others:University Hospital Hradec Kralove(CZ) 00179906; Faculty of Military Health Sciences, University of Defence(CZ) SV/FVZ201402 Institutional support: RVO:68378050 Keywords : DEPENDENT PROTEIN-KINASE * STRAND BREAK REPAIR * SELECTIVE PI3K-BETA INHIBITORS * TELANGIECTASIA MUTATED KINASE Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.589, year: 2015

  13. Selective elimination of neuroblastoma cells by synergistic effect of Akt kinase inhibitor and tetrathiomolybdate.

    Science.gov (United States)

    Navrátilová, Jarmila; Karasová, Martina; Kohutková Lánová, Martina; Jiráková, Ludmila; Budková, Zuzana; Pacherník, Jiří; Šmarda, Jan; Beneš, Petr

    2017-09-01

    Neuroblastoma is the most common extracranial solid tumour of infancy. Pathological activation of glucose consumption, glycolysis and glycolysis-activating Akt kinase occur frequently in neuroblastoma cells, and these changes correlate with poor prognosis of patients. Therefore, several inhibitors of glucose utilization and the Akt kinase activity are in preclinical trials as potential anti-cancer drugs. However, metabolic plasticity of cancer cells might undermine efficacy of this approach. In this work, we identified oxidative phosphorylation as compensatory mechanism preserving viability of neuroblastoma cells with inhibited glucose uptake/Akt kinase. It was oxidative phosphorylation that maintained intracellular level of ATP and proliferative capacity of these cells. The oxidative phosphorylation inhibitors (rotenone, tetrathiomolybdate) synergized with inhibitor of the Akt kinase/glucose uptake in down-regulation of both viability of neuroblastoma cells and clonogenic potential of cells forming neuroblastoma spheroids. Interestingly, tetrathiomolybdate acted as highly specific inhibitor of oxygen consumption and activator of lactate production in neuroblastoma cells, but not in normal fibroblasts and neuronal cells. Moreover, the reducing effect of tetrathiomolybdate on cell viability and the level of ATP in the cells with inhibited Akt kinase/glucose uptake was also selective for neuroblastoma cells. Therefore, efficient elimination of neuroblastoma cells requires inhibition of both glucose uptake/Akt kinase and oxidative phosphorylation activities. The use of tetrathiomolybdate as a mitochondrial inhibitor contributes to selectivity of this combined treatment, preferentially targeting neuroblastoma cells. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  14. Kinase inhibitors can produce off-target effects and activate linked pathways by retroactivity

    Directory of Open Access Journals (Sweden)

    Wynn Michelle L

    2011-10-01

    Full Text Available Abstract Background It has been shown in experimental and theoretical work that covalently modified signaling cascades naturally exhibit bidirectional signal propagation via a phenomenon known as retroactivity. An important consequence of retroactivity, which arises due to enzyme sequestration in covalently modified signaling cascades, is that a downstream perturbation can produce a response in a component upstream of the perturbation without the need for explicit feedback connections. Retroactivity may, therefore, play an important role in the cellular response to a targeted therapy. Kinase inhibitors are a class of targeted therapies designed to interfere with a specific kinase molecule in a dysregulated signaling pathway. While extremely promising as anti-cancer agents, kinase inhibitors may produce undesirable off-target effects by non-specific interactions or pathway cross-talk. We hypothesize that targeted therapies such as kinase inhibitors can produce off-target effects as a consequence of retroactivity alone. Results We used a computational model and a series of simple signaling motifs to test the hypothesis. Our results indicate that within physiologically and therapeutically relevant ranges for all parameters, a targeted inhibitor can naturally induce an off-target effect via retroactivity. The kinetics governing covalent modification cycles in a signaling network were more important for propagating an upstream off-target effect in our models than the kinetics governing the targeted therapy itself. Our results also reveal the surprising and crucial result that kinase inhibitors have the capacity to turn "on" an otherwise "off" parallel cascade when two cascades share an upstream activator. Conclusions A proper and detailed characterization of a pathway's structure is important for identifying the optimal protein to target as well as what concentration of the targeted therapy is required to modulate the pathway in a safe and effective

  15. oxLDL induces endothelial cell proliferation via Rho/ROCK/Akt/p27kip1 signaling: opposite effects of oxLDL and cholesterol loading.

    Science.gov (United States)

    Zhang, Chongxu; Adamos, Crystal; Oh, Myung-Jin; Baruah, Jugajyoti; Ayee, Manuela A A; Mehta, Dolly; Wary, Kishore K; Levitan, Irena

    2017-09-01

    Oxidized modifications of LDL (oxLDL) play a key role in the development of endothelial dysfunction and atherosclerosis. However, the underlying mechanisms of oxLDL-mediated cellular behavior are not completely understood. Here, we compared the effects of two major types of oxLDL, copper-oxidized LDL (Cu 2+ -oxLDL) and lipoxygenase-oxidized LDL (LPO-oxLDL), on proliferation of human aortic endothelial cells (HAECs). Cu 2+ -oxLDL enhanced HAECs' proliferation in a dose- and degree of oxidation-dependent manner. Similarly, LPO-oxLDL also enhanced HAEC proliferation. Mechanistically, both Cu 2+ -oxLDL and LPO-oxLDL enhance HAEC proliferation via activation of Rho, Akt phosphorylation, and a decrease in the expression of cyclin-dependent kinase inhibitor 1B (p27 kip1 ). Both Cu 2+ -oxLDL or LPO-oxLDL significantly increased Akt phosphorylation, whereas an Akt inhibitor, MK2206, blocked oxLDL-induced increase in HAEC proliferation. Blocking Rho with C3 or its downstream target ROCK with Y27632 significantly inhibited oxLDL-induced Akt phosphorylation and proliferation mediated by both Cu 2+ - and LPO-oxLDL. Activation of RhoA was blocked by Rho-GDI-1, which also abrogated oxLDL-induced Akt phosphorylation and HAEC proliferation. In contrast, blocking Rac1 in these cells had no effect on oxLDL-induced Akt phosphorylation or cell proliferation. Moreover, oxLDL-induced Rho/Akt signaling downregulated cell cycle inhibitor p27 kip1 Preloading these cells with cholesterol, however, prevented oxLDL-induced Akt phosphorylation and HAEC proliferation. These findings provide a new understanding of the effects of oxLDL on endothelial proliferation, which is essential for developing new treatments against neovascularization and progression of atherosclerosis. Copyright © 2017 the American Physiological Society.

  16. RhoA and RhoC are involved in stromal cell-derived factor-1-induced cell migration by regulating F-actin redistribution and assembly.

    Science.gov (United States)

    Luo, Jixian; Li, Dingyun; Wei, Dan; Wang, Xiaoguang; Wang, Lan; Zeng, Xianlu

    2017-12-01

    Stromal cell-derived factor-1 (SDF-1) signaling is important to the maintenance and progression of T-cell acute lymphoblastic leukemia by inducing chemotaxis migration. To identify the mechanism of SDF-1 signaling in the migration of T-ALL, Jurkat acute lymphoblastic leukemia cells were used. Results showed that SDF-1 induces Jurkat cell migration by F-actin redistribution and assembly, which is dependent on Rho activity. SDF-1 induced RhoA and RhoC activation, as well as reactive oxygen species (ROS) production, which was inhibited by Rho inhibitor. The Rho-dependent ROS production led to subsequent cytoskeleton redistribution and assembly in the process of migration. Additionally, RhoA and RhoC were involved in SDF-1-induced Jurkat cell migration. Taken together, we found a SDF-1/CXCR4-RhoA and RhoC-ROS-cytoskeleton pathway that regulates Jurkat cell migration in response to SDF-1. This work will contribute to a clearer insight into the migration mechanism of acute lymphoblastic leukemia.

  17. Discovery of novel EGFR tyrosine kinase inhibitors by structure-based virtual screening.

    Science.gov (United States)

    Li, Siyuan; Sun, Xianqiang; Zhao, Hongli; Tang, Yun; Lan, Minbo

    2012-06-15

    By using of structure-based virtual screening, 13 novel epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors were discovered from 197,116 compounds in the SPECS database here. Among them, 8 compounds significantly inhibited EGFR kinase activity with IC(50) values lower than 10 μM. 3-{[1-(3-Chloro-4-fluorophenyl)-3,5-dioxo-4-pyrazolidinylidene]methyl}phenyl 2-thiophenecarboxylate (13), particularly, was the most potent inhibitor possessing the IC(50) value of 3.5 μM. The docking studies also provide some useful information that the docking models of the 13 compounds are beneficial to find a new path for designing novel EGFR inhibitors. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Preparation of kinase-biased compounds in the search for lead inhibitors of kinase targets.

    Science.gov (United States)

    Lai, Justine Y Q; Langston, Steven; Adams, Ruth; Beevers, Rebekah E; Boyce, Richard; Burckhardt, Svenja; Cobb, James; Ferguson, Yvonne; Figueroa, Eva; Grimster, Neil; Henry, Andrew H; Khan, Nawaz; Jenkins, Kerry; Jones, Mark W; Judkins, Robert; Major, Jeremy; Masood, Abid; Nally, James; Payne, Helen; Payne, Lloyd; Raphy, Gilles; Raynham, Tony; Reader, John; Reader, Valérie; Reid, Alison; Ruprah, Parminder; Shaw, Michael; Sore, Hannah; Stirling, Matthew; Talbot, Adam; Taylor, Jess; Thompson, Stephen; Wada, Hiroki; Walker, David

    2005-05-01

    This work describes the preparation of approximately 13,000 compounds for rapid identification of hits in high-throughput screening (HTS). These compounds were designed as potential serine/threonine or tyrosine kinase inhibitors. The library consists of various scaffolds, e.g., purines, oxindoles, and imidazoles, whereby each core scaffold generally includes the hydrogen bond acceptor/donor properties known to be important for kinase binding. Several of these are based upon literature kinase templates, or adaptations of them to provide novelty. The routes to their preparation are outlined. A variety of automation techniques were used to prepare >500 compounds per scaffold. Where applicable, scavenger resins were employed to remove excess reagents and when necessary, preparative high performance liquid chromatography (HPLC) was used for purification. These compounds were screened against an 'in-house' kinase panel. The success rate in HTS was significantly higher than the corporate compound collection. Copyright (c) 2004 Wiley Periodicals, Inc.

  19. FUS-CHOP Promotes Invasion in Myxoid Liposarcoma through a SRC/FAK/RHO/ROCK-Dependent Pathway

    Directory of Open Access Journals (Sweden)

    Juan Tornin

    2018-01-01

    Full Text Available Deregulated SRC/FAK signaling leads to enhanced migration and invasion in many types of tumors. In myxoid and round cell liposarcoma (MRCLS, an adipocytic tumor characterized by the expression of the fusion oncogene FUS-CHOP, SRC have been found as one of the most activated kinases. Here we used a cell-of-origin model of MRCLS and an MRCLS cell line to thoroughly characterize the mechanisms of cell invasion induced by FUS-CHOP using in vitro (3D spheroid invasion assays and in vivo (chicken chorioallantoic membrane model approaches. FUS-CHOP expression activated SRC-FAK signaling and increased the invasive ability of MRCLS cells. In addition, FAK expression was found to significantly correlate with tumor aggressiveness in sarcoma patient samples. The involvement of SRC/FAK activation in FUS-CHOP–mediated invasion was further confirmed using the SRC inhibitor dasatinib, the specific FAK inhibitor PF-573228, and FAK siRNA. Notably, dasatinib and PF573228 could also efficiently block the invasion of cancer stem cell subpopulations. Downstream of SRC/FAK signaling, we found that FUS-CHOP expression increases the levels of the RHO/ROCK downstream effector phospho-MLC2 (T18/S19 and that this activation was prevented by dasatinib or PF573228. Moreover, the ROCK inhibitor RKI-1447 was able to completely abolish invasion in FUS-CHOP–expressing cells. These data uncover the involvement of SRC/FAK/RHO/ROCK signaling axis in FUS-CHOP–mediated invasion, thus providing a rationale for testing inhibitors of this pathway as potential novel antimetastatic agents for MRCLS treatment.

  20. Maintaining glycogen synthase kinase-3 activity is critical for mTOR kinase inhibitors to inhibit cancer cell growth.

    Science.gov (United States)

    Koo, Junghui; Yue, Ping; Gal, Anthony A; Khuri, Fadlo R; Sun, Shi-Yong

    2014-05-01

    mTOR kinase inhibitors that target both mTORC1 and mTORC2 are being evaluated in cancer clinical trials. Here, we report that glycogen synthase kinase-3 (GSK3) is a critical determinant for the therapeutic response to this class of experimental drugs. Pharmacologic inhibition of GSK3 antagonized their suppressive effects on the growth of cancer cells similarly to genetic attenuation of GSK3. Conversely, expression of a constitutively activated form of GSK3β sensitized cancer cells to mTOR inhibition. Consistent with these findings, higher basal levels of GSK3 activity in a panel of human lung cancer cell lines correlated with more efficacious responses. Mechanistic investigations showed that mTOR kinase inhibitors reduced cyclin D1 levels in a GSK3β-dependent manner, independent of their effects on suppressing mTORC1 signaling and cap binding. Notably, selective inhibition of mTORC2 triggered proteasome-mediated cyclin D1 degradation, suggesting that mTORC2 blockade is responsible for GSK3-dependent reduction of cyclin D1. Silencing expression of the ubiquitin E3 ligase FBX4 rescued this reduction, implicating FBX4 in mediating this effect of mTOR inhibition. Together, our findings define a novel mechanism by which mTORC2 promotes cell growth, with potential implications for understanding the clinical action of mTOR kinase inhibitors. ©2014 AACR.

  1. Effect of QSKL on MAPK and RhoA Pathways in a Rat Model of Heart Failure

    Directory of Open Access Journals (Sweden)

    Kai Xia

    2017-01-01

    Full Text Available Qishenkeli (QSKL is one of the Chinese medicine formulae for treating heart failure and has been shown to have an antifibrotic effect. However, the mechanism of its therapeutic effects remains unclear. In this study, we aimed to explore whether QSKL could exert an antifibrotic effect by attenuating ras homolog family member A (RhoA and mitogen activated protein kinase (MAPK pathways. Rats were randomly divided into sham group, model group, QSKL group, and positive control group. Heart failure was induced by ligation of the left ventricle anterior descending artery. Cardiac functions were measured by echocardiography and collagen deposition was assessed by Masson staining. Expressions of the key molecules involved in the RhoA and MAPK pathways were also measured. Twenty-one days after surgery, cardiac functions were severely impaired and collagen deposition was remarkable, while QSKL treatment could improve heart functions and alleviate collagen deposition. Further results demonstrated that the effects may be mediated by suppressing expressions of extracellular signal-regulated kinase (ERK and c-Jun N-terminal kinase (JNK. Moreover, expressions of RhoA, Rho-associated protein kinase 1/2 (ROCK1/2, and phosphorylated myosin light chain (p-MLC were also downregulated by QSKL compared with the model group. The cardioprotective mechanism of QSKL on heart failure is probably mediated by regulating both the MAPK and RhoA signaling pathways.

  2. Structure-based discovery of inhibitors of the YycG histidine kinase

    DEFF Research Database (Denmark)

    Qin, X.; Zhang, J.; Xu, B.

    2006-01-01

    inhibitors of YycG histidine kinase thus are of potential value as leads for developing new antibiotics against infecting staphylococci. The structure-based virtual screening (SBVS) technology can be widely used in screening potential inhibitors of other bacterial TCSs, since it is more rapid and efficacious...... than traditional screening technology....

  3. Aldehyde Dehydrogenase 1 and Raf Kinase Inhibitor Protein ...

    African Journals Online (AJOL)

    Aldehyde Dehydrogenase 1 and Raf Kinase Inhibitor Protein Expression Defines the Proliferative Nature of Cervical Cancer Stem Cells. ... of cervical cancer stem cells and also to validate them in initial and advanced stages of cervical cancer. Keywords: Cervical cancer, ALDH1, BALB/c-nu/nu, HeLa cells, RKIP, Sox2 ...

  4. High-throughput screening to identify inhibitors which stabilize inactive kinase conformations in p38 alpha

    NARCIS (Netherlands)

    Simard, J.R.; Grutter, C.; Pawar, V.; Aust, B.; Wolf, A.; Rabiller, M.; Wulfert, S.; Robubi, A.; Kluter, S.; Ottmann, C.; Rauh, D.

    2009-01-01

    Small molecule kinase inhibitors are an attractive means to modulate kinase activities in medicinal chemistry and chemical biology research. In the physiological setting of a cell, kinase function is orchestrated by a plethora of regulatory processes involving the structural transition of kinases

  5. Bosutinib induced pleural effusions: Case report and review of tyrosine kinase inhibitors induced pulmonary toxicity

    Directory of Open Access Journals (Sweden)

    Natalia I. Moguillansky, MD

    2017-01-01

    Full Text Available Tyrosine kinase inhibitors are known to cause pulmonary complications. We report a case of bosutinib related bilateral pleural effusions in a patient with chronic myeloid leukemia. Characteristics of the pleural fluid are presented. We also discuss other tyrosine kinase inhibitors induced pulmonary toxicities, including pulmonary hypertension and interstitial lung disease.

  6. Induction of human microsomal prostaglandin E synthase 1 by activated oncogene RhoA GTPase in A549 human epithelial cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hye Jin [Laboratory of Systems Mucosal Biomodulation, Department of Microbiology and Immunology, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Lee, Dong-Hyung [Department of Obstetrics and Gynecology, Medical Research Institute, Pusan National University, Busan (Korea, Republic of); Park, Seong-Hwan; Kim, Juil; Do, Kee Hun [Laboratory of Systems Mucosal Biomodulation, Department of Microbiology and Immunology, Pusan National University School of Medicine, Yangsan (Korea, Republic of); An, Tae Jin; Ahn, Young Sup; Park, Chung Berm [Department of Herbal Crop Research, NIHHS, RDA, Eumseong (Korea, Republic of); Moon, Yuseok, E-mail: moon@pnu.edu [Laboratory of Systems Mucosal Biomodulation, Department of Microbiology and Immunology, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Medical Research Institute and Research Institute for Basic Sciences, Pusan National University, Busan (Korea, Republic of)

    2011-09-30

    Highlights: {yields} As a target of oncogene RhoA-linked signal, a prostaglandin metabolism is assessed. {yields} RhoA activation increases PGE{sub 2} levels and its metabolic enzyme mPGES-1. {yields} RhoA-activated NF-{kappa}B and EGR-1 are positively involved in mPGES-1 induction. -- Abstract: Oncogenic RhoA GTPase has been investigated as a mediator of pro-inflammatory responses and aggressive carcinogenesis. Among the various targets of RhoA-linked signals, pro-inflammatory prostaglandin E{sub 2} (PGE{sub 2}), a major prostaglandin metabolite, was assessed in epithelial cancer cells. RhoA activation increased PGE{sub 2} levels and gene expression of the rate-limiting PGE{sub 2} producing enzymes, cyclooxygenase-2 and microsomal prostaglandin E synthase 1 (mPGES-1). In particular, human mPGES-1 was induced by RhoA via transcriptional activation in control and interleukin (IL)-1{beta}-activated cancer cells. To address the involvement of potent signaling pathways in RhoA-activated mPGES-1 induction, various signaling inhibitors were screened for their effects on mPGES-1 promoter activity. RhoA activation enhanced basal and IL-1{beta}-mediated phosphorylated nuclear factor-{kappa}B and extracellular signal-regulated kinase1/2 proteins, all of which were positively involved in RhoA-induced gene expression of mPGES-1. As one potent down-stream transcription factor of ERK1/2 signals, early growth response gene 1 product also mediated RhoA-induced gene expression of mPGES-1 by enhancing transcriptional activity. Since oncogene-triggered PGE{sub 2} production is a critical modulator of epithelial tumor cells, RhoA-associated mPGES-1 represents a promising chemo-preventive or therapeutic target for epithelial inflammation and its associated cancers.

  7. Computational Analysis of Epidermal Growth Factor Receptor Mutations Predicts Differential Drug Sensitivity Profiles toward Kinase Inhibitors.

    Science.gov (United States)

    Akula, Sravani; Kamasani, Swapna; Sivan, Sree Kanth; Manga, Vijjulatha; Vudem, Dashavantha Reddy; Kancha, Rama Krishna

    2018-05-01

    A significant proportion of patients with lung cancer carry mutations in the EGFR kinase domain. The presence of a deletion mutation in exon 19 or L858R point mutation in the EGFR kinase domain has been shown to cause enhanced efficacy of inhibitor treatment in patients with NSCLC. Several less frequent (uncommon) mutations in the EGFR kinase domain with potential implications in treatment response have also been reported. The role of a limited number of uncommon mutations in drug sensitivity was experimentally verified. However, a huge number of these mutations remain uncharacterized for inhibitor sensitivity or resistance. A large-scale computational analysis of clinically reported 298 point mutants of EGFR kinase domain has been performed, and drug sensitivity profiles for each mutant toward seven kinase inhibitors has been determined by molecular docking. In addition, the relative inhibitor binding affinity toward each drug as compared with that of adenosine triphosphate was calculated for each mutant. The inhibitor sensitivity profiles predicted in this study for a set of previously characterized mutants correlated well with the published clinical, experimental, and computational data. Both the single and compound mutations displayed differential inhibitor sensitivity toward first- and next-generation kinase inhibitors. The present study provides predicted drug sensitivity profiles for a large panel of uncommon EGFR mutations toward multiple inhibitors, which may help clinicians in deciding mutant-specific treatment strategies. Copyright © 2018 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

  8. The Discovery of Aurora Kinase Inhibitor by Multi-Docking-Based Virtual Screening

    Directory of Open Access Journals (Sweden)

    Jun-Tae Kim

    2014-11-01

    Full Text Available We report the discovery of aurora kinase inhibitor using the fragment-based virtual screening by multi-docking strategy. Among a number of fragments collected from eMololecules, we found four fragment molecules showing potent activity (>50% at 100 μM against aurora kinase. Based on the explored fragment scaffold, we selected two compounds in our synthesized library and validated the biological activity against Aurora kinase.

  9. Theoretical study on the interaction of pyrrolopyrimidine derivatives as LIMK2 inhibitors: insight into structure-based inhibitor design.

    Science.gov (United States)

    Shen, Mingyun; Zhou, Shunye; Li, Youyong; Li, Dan; Hou, Tingjun

    2013-10-01

    LIM kinases (LIMKs), downstream of Rho-associated protein kinases (ROCKs) and p21-activated protein kinases (PAKs), are shown to be promising targets for the treatment of cancers. In this study, the inhibition mechanism of 41 pyrrolopyrimidine derivatives as LIMK2 inhibitors was explored through a series of theoretical approaches. First, a model of LIMK2 was generated through molecular homology modeling, and the studied inhibitors were docked into the binding active site of LIMK2 by the docking protocol, taking into consideration the flexibility of the protein. The binding poses predicted by molecular docking for 17 selected inhibitors with different bioactivities complexed with LIMK2 underwent molecular dynamics (MD) simulations, and the binding free energies for the complexes were predicted by using the molecular mechanics/generalized born surface area (MM/GBSA) method. The predicted binding free energies correlated well with the experimental bioactivities (r(2) = 0.63 or 0.62). Next, the free energy decomposition analysis was utilized to highlight the following key structural features related to biological activity: (1) the important H-bond between Ile408 and pyrrolopyrimidine, (2) the H-bonds between the inhibitors and Asp469 and Gly471 which maintain the stability of the DFG-out conformation, and (3) the hydrophobic interactions between the inhibitors and several key residues (Leu337, Phe342, Ala345, Val358, Lys360, Leu389, Ile408, Leu458 and Leu472). Finally, a variety of LIMK2 inhibitors with a pyrrolopyrimidine scaffold were designed, some of which showed improved potency according to the predictions. Our studies suggest that the use of molecular docking with MD simulations and free energy calculations could be a powerful tool for understanding the binding mechanism of LIMK2 inhibitors and for the design of more potent LIMK2 inhibitors.

  10. Structure of Human G Protein-Coupled Receptor Kinase 2 in Complex with the Kinase Inhibitor Balanol

    Energy Technology Data Exchange (ETDEWEB)

    Tesmer, John J.G.; Tesmer, Valerie M.; Lodowski, David T.; Steinhagen, Henning; Huber, Jochen (Sanofi); (Michigan); (Texas)

    2010-07-19

    G protein-coupled receptor kinase 2 (GRK2) is a pharmaceutical target for the treatment of cardiovascular diseases such as congestive heart failure, myocardial infarction, and hypertension. To better understand how nanomolar inhibition and selectivity for GRK2 might be achieved, we have determined crystal structures of human GRK2 in complex with G{beta}{gamma} in the presence and absence of the AGC kinase inhibitor balanol. The selectivity of balanol among human GRKs is assessed.

  11. Scambio, a novel guanine nucleotide exchange factor for Rho

    Directory of Open Access Journals (Sweden)

    Groffen John

    2004-04-01

    Full Text Available Abstract Background Small GTPases of the Rho family are critical regulators of various cellular functions including actin cytoskeleton organization, activation of kinase cascades and mitogenesis. For this reason, a major objective has been to understand the mechanisms of Rho GTPase regulation. Here, we examine the function of a novel protein, Scambio, which shares homology with the DH-PH domains of several known guanine nucleotide exchange factors for Rho family members. Results Scambio is located on human chromosome 14q11.1, encodes a protein of around 181 kDa, and is highly expressed in both heart and skeletal muscle. In contrast to most DH-PH-domain containing proteins, it binds the activated, GTP-bound forms of Rac and Cdc42. However, it fails to associate with V14RhoA. Immunofluorescence studies indicate that Scambio and activated Rac3 colocalize in membrane ruffles at the cell periphery. In accordance with these findings, Scambio does not activate either Rac or Cdc42 but rather, stimulates guanine nucleotide exchange on RhoA and its close relative, RhoC. Conclusion Scambio associates with Rac in its activated conformation and functions as a guanine nucleotide exchange factor for Rho.

  12. The small GTPase RhoH is an atypical regulator of haematopoietic cells

    Directory of Open Access Journals (Sweden)

    Kubatzky Katharina F

    2008-09-01

    implicated as a regulatory molecule in the NFκB, PI3 kinase and Map kinase pathways. The recent generation of RhoH knockout mice showed a defect in thymocyte selection and TCR signalling of thymic and peripheral T-cells. However, RhoH-deficient mice did not develop lymphomas or showed obvious defects in haematopoiesis.

  13. Cholesterol modulates the volume-regulated anion current in Ehrlich-Lettre ascites cells via effects on Rho and F-actin

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjaer; Hougaard, Charlotte; Hoffmann, Else K

    2006-01-01

    swollen cells, this reduction was prevented by cholesterol depletion, which also increased isotonic Rho activity. Thrombin, which stimulates Rho and causes actin polymerization, potentiated VRAC in modestly swollen cells. VRAC activity was unaffected by inclusion of a water-soluble PtdIns(4,5)P(2......) analogue or a PtdIns(4,5)P(2)-blocking antibody in the pipette, or neomycin treatment to sequester PtdIns(4,5)P(2). It is suggested that in ELA cells, F-actin and Rho-Rho kinase modulate VRAC magnitude and activation rate, respectively, and that cholesterol depletion potentiates VRAC at least in part......The mechanisms controlling the volume-regulated anion current (VRAC) are incompletely elucidated. Here, we investigate the modulation of VRAC by cellular cholesterol and the potential involvement of F-actin, Rho, Rho kinase, and phosphatidylinositol-(4,5)-bisphosphate [PtdIns(4,5)P(2...

  14. Determination of human serum alpha1-acid glycoprotein and albumin binding of various marketed and preclinical kinase inhibitors.

    Science.gov (United States)

    Zsila, Ferenc; Fitos, Ilona; Bencze, Gyula; Kéri, György; Orfi, László

    2009-01-01

    There are about 380 protein kinase inhibitors in drug development as of today and 15 drugs have been marketed already for the treatment of cancer. This time 139 validated kinase targets are in the focus of drug research of pharmaceutical companies and big efforts are made for the development of new, druglike kinase inhibitors. Plasma protein binding is an important factor of the ADME profiling of a drug compound. Human serum albumin (HSA) and alpha(1)-acid glycoprotein (AAG) are the most relevant drug carriers in blood plasma. Since previous literature data indicated that AAG is the principal plasma binding component of some kinase inhibitors the present work focuses on the comprehensive evaluation of AAG binding of a series of marketed and experimental kinase inhibitors by using circular dichroism (CD) spectroscopy approach. HSA binding was also evaluated by affinity chromatography. Protein binding interactions of twenty-six kinase inhibitors are characterized. The contribution of AAG and HSA binding data to the pharmacokinetic profiles of the investigated therapeutic agents is discussed. Structural, biological and drug binding properties of AAG as well as the applicability of the CD method in studying drug-protein binding interactions are also briefly reviewed.

  15. Variability in bioavailability of small molecular tyrosine kinase inhibitors

    NARCIS (Netherlands)

    Herbrink, Maikel; Nuijen, Bastiaan; Schellens, Jan H M; Beijnen, Jos H.

    2015-01-01

    Small molecular tyrosine kinase inhibitors (smTKIs) are in the centre of the very quickly expanding area of personalized chemotherapy and oral applicability thereof. The number of drugs in this class is rapidly growing, with twenty current approvals by both the European Medicines Agency (EMA) and

  16. Identifying Inhibitors of Inflammation: A Novel High-Throughput MALDI-TOF Screening Assay for Salt-Inducible Kinases (SIKs).

    Science.gov (United States)

    Heap, Rachel E; Hope, Anthony G; Pearson, Lesley-Anne; Reyskens, Kathleen M S E; McElroy, Stuart P; Hastie, C James; Porter, David W; Arthur, J Simon C; Gray, David W; Trost, Matthias

    2017-12-01

    Matrix-assisted laser desorption/ionization time-of-flight (MALDI TOF) mass spectrometry has become a promising alternative for high-throughput drug discovery as new instruments offer high speed, flexibility and sensitivity, and the ability to measure physiological substrates label free. Here we developed and applied high-throughput MALDI TOF mass spectrometry to identify inhibitors of the salt-inducible kinase (SIK) family, which are interesting drug targets in the field of inflammatory disease as they control production of the anti-inflammatory cytokine interleukin-10 (IL-10) in macrophages. Using peptide substrates in in vitro kinase assays, we can show that hit identification of the MALDI TOF kinase assay correlates with indirect ADP-Hunter kinase assays. Moreover, we can show that both techniques generate comparable IC 50 data for a number of hit compounds and known inhibitors of SIK kinases. We further take these inhibitors to a fluorescence-based cellular assay using the SIK activity-dependent translocation of CRTC3 into the nucleus, thereby providing a complete assay pipeline for the identification of SIK kinase inhibitors in vitro and in cells. Our data demonstrate that MALDI TOF mass spectrometry is fully applicable to high-throughput kinase screening, providing label-free data comparable to that of current high-throughput fluorescence assays.

  17. Fragment-based approaches to the discovery of kinase inhibitors.

    Science.gov (United States)

    Mortenson, Paul N; Berdini, Valerio; O'Reilly, Marc

    2014-01-01

    Protein kinases are one of the most important families of drug targets, and aberrant kinase activity has been linked to a large number of disease areas. Although eminently targetable using small molecules, kinases present a number of challenges as drug targets, not least obtaining selectivity across such a large and relatively closely related target family. Fragment-based drug discovery involves screening simple, low-molecular weight compounds to generate initial hits against a target. These hits are then optimized to more potent compounds via medicinal chemistry, usually facilitated by structural biology. Here, we will present a number of recent examples of fragment-based approaches to the discovery of kinase inhibitors, detailing the construction of fragment-screening libraries, the identification and validation of fragment hits, and their optimization into potent and selective lead compounds. The advantages of fragment-based methodologies will be discussed, along with some of the challenges associated with using this route. Finally, we will present a number of key lessons derived both from our own experience running fragment screens against kinases and from a large number of published studies.

  18. Identification of anti-proliferative kinase inhibitors as potential therapeutic agents to treat canine osteosarcoma.

    Science.gov (United States)

    Mauchle, Ulrike; Selvarajah, Gayathri T; Mol, Jan A; Kirpensteijn, Jolle; Verheije, Monique H

    2015-08-01

    Osteosarcoma is the most common primary bone tumour in dogs but various forms of therapy have not significantly improved clinical outcomes. As dysregulation of kinase activity is often present in tumours, kinases represent attractive molecular targets for cancer therapy. The purpose of this study was to identify novel compounds targeting kinases with the potential to induce cell death in a panel of canine osteosarcoma cell lines. The ability of 80 well-characterized kinase inhibitor compounds to inhibit the proliferation of four canine osteosarcoma cell lines was investigated in vitro. For those compounds with activity, the mechanism of action and capability to potentiate the activity of doxorubicin was further evaluated. The screening showed 22 different kinase inhibitors that induced significant anti-proliferative effects across the four canine osteosarcoma cell lines investigated. Four of these compounds (RO 31-8220, 5-iodotubercidin, BAY 11-7082 and an erbstatin analog) showed significant cell growth inhibitory effects across all cell lines in association with variable induction of apoptosis. RO 31-8220 and 5-iodotubercidin showed the highest ability to potentiate the effects of doxorubicin on cell viability. In conclusion, the present study identified several potent kinase inhibitors targeting the PKC, CK1, PKA, ErbB2, mTOR and NF-κB pathways, which may warrant further investigations for the treatment of osteosarcoma in dogs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. [Effect of inhibitors serine/threonine protein kinases and protein phosphatases on mitosis progression of synchronized tobacco by-2 cells].

    Science.gov (United States)

    Sheremet, Ia A; Emets, A I; Azmi, A; Vissenberg, K; Verbelen, J-P; Blium, Ia B

    2012-01-01

    In order to investigate the role of various serine/ threonine protein kinases and protein phosphatases in the regulation of mitosis progression in plant cells the influence of cyclin-dependent (olomoucine) and Ca2+ -calmodulin-dependent (W7) protein kinases inhibitors, as well as protein kinase C inhibitors (H7 and staurosporine) and protein phosphatases inhibitor (okadaic acid) on mitosis progression in synchronized tobacco BY-2 cells has been studied. It was found that BY-2 culture treatment with inhibitors of cyclin dependent protein kinases and protein kinase C causes prophase delay, reduces the mitotic index and displaces of mitotic peak as compare with control cells. Inhibition of Ca2+ -calmodulin dependent protein kinases enhances the cell entry into prophase and delays their exit from mitosis. Meanwhile inhibition of serine/threonine protein phosphatases insignificantly enhances of synchronized BY-2 cells entering into all phases of mitosis.

  20. Fragment-Based Drug Discovery of Potent Protein Kinase C Iota Inhibitors.

    Science.gov (United States)

    Kwiatkowski, Jacek; Liu, Boping; Tee, Doris Hui Ying; Chen, Guoying; Ahmad, Nur Huda Binte; Wong, Yun Xuan; Poh, Zhi Ying; Ang, Shi Hua; Tan, Eldwin Sum Wai; Ong, Esther Hq; Nurul Dinie; Poulsen, Anders; Pendharkar, Vishal; Sangthongpitag, Kanda; Lee, May Ann; Sepramaniam, Sugunavathi; Ho, Soo Yei; Cherian, Joseph; Hill, Jeffrey; Keller, Thomas H; Hung, Alvin W

    2018-05-24

    Protein kinase C iota (PKC-ι) is an atypical kinase implicated in the promotion of different cancer types. A biochemical screen of a fragment library has identified several hits from which an azaindole-based scaffold was chosen for optimization. Driven by a structure-activity relationship and supported by molecular modeling, a weakly bound fragment was systematically grown into a potent and selective inhibitor against PKC-ι.

  1. Review of current classification, molecular alterations, and tyrosine kinase inhibitor therapies in myeloproliferative disorders with hypereosinophilia

    Directory of Open Access Journals (Sweden)

    Havelange V

    2013-08-01

    Full Text Available Violaine Havelange,1,2 Jean-Baptiste Demoulin1 1de Duve Institute, Université catholique de Louvain, Brussels, Belgium; 2Department of Hematology, Cliniques universitaires Saint-Luc, Université catholique de Louvain, Brussels, Belgium Abstract: Recent advances in our understanding of the molecular mechanisms underlying hypereosinophilia have led to the development of a 'molecular' classification of myeloproliferative disorders with eosinophilia. The revised 2008 World Health Organization classification of myeloid neoplasms included a new category called “myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB or FGFR1.” Despite the molecular heterogeneity of PDGFR (platelet-derived growth factor receptor rearrangements, tyrosine kinase inhibitors at low dose induce rapid and complete hematological remission in the majority of these patients. Other kinase inhibitors are promising. Further discoveries of new molecular alterations will direct the development of new specific inhibitors. In this review, an update of the classifications of myeloproliferative disorders associated with hypereosinophilia is discussed together with open and controversial questions. Molecular mechanisms and promising results of tyrosine kinase inhibitor treatments are reviewed. Keywords: hypereosinophilia, classification, myeloproliferative disorders, molecular alterations, tyrosine kinase inhibitor

  2. Mechanism of RhoB/FTI Action in Breast Cancer

    National Research Council Canada - National Science Library

    Kamasani, Uma

    2003-01-01

    .... What factors dictate FTI efficacy? Work completed earlier in this project defined rules for RhoB and its downstream effector kinase PRK in mediating growth inhibition by FTI in epithelial cells, including human breast epithelial cells...

  3. Efficacy of ponatinib against ABL tyrosine kinase inhibitor-resistant leukemia cells

    International Nuclear Information System (INIS)

    Okabe, Seiichi; Tauchi, Tetsuzo; Tanaka, Yuko; Ohyashiki, Kazuma

    2013-01-01

    Highlights: •Efficacy of ponatinib against ABL tyrosine kinase inhibitor-resistant leukemia cells okabe et al. •Imatinib or nilotinib resistance was involved Src family kinase. •The BCR-ABL point mutation (E334V) was highly resistant to imatinib or nilotinib. •Ponatinib was a powerful strategy against imatinib or nilotinib resistant Ph-positive cells. -- Abstract: Because a substantial number of patients with chronic myeloid leukemia acquire resistance to ABL tyrosine kinase inhibitors (TKIs), their management remains a challenge. Ponatinib, also known as AP24534, is an oral multi-targeted TKI. Ponatinib is currently being investigated in a pivotal phase 2 clinical trial. In the present study, we analyzed the molecular and functional consequences of ponatinib against imatinib- or nilotinib-resistant (R) K562 and Ba/F3 cells. The proliferation of imatinib- or nilotinib-resistant K562 cells did not decrease after treatment with imatinib or nilotinib. Src family kinase Lyn was activated. Point mutation Ba/F3 cells (E334 V) were also highly resistant to imatinib and nilotinib. Treatment with ponatinib for 72 h inhibited the growth of imatinib- and nilotinib-resistant cells. The phosphorylation of BCR-ABL, Lyn, and Crk-L was reduced. This study demonstrates that ponatinib has an anti-leukemia effect by reducing ABL and Lyn kinase activity and this information may be of therapeutic relevance

  4. Efficacy of ponatinib against ABL tyrosine kinase inhibitor-resistant leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Okabe, Seiichi, E-mail: okabe@tokyo-med.ac.jp; Tauchi, Tetsuzo; Tanaka, Yuko; Ohyashiki, Kazuma

    2013-06-07

    Highlights: •Efficacy of ponatinib against ABL tyrosine kinase inhibitor-resistant leukemia cells okabe et al. •Imatinib or nilotinib resistance was involved Src family kinase. •The BCR-ABL point mutation (E334V) was highly resistant to imatinib or nilotinib. •Ponatinib was a powerful strategy against imatinib or nilotinib resistant Ph-positive cells. -- Abstract: Because a substantial number of patients with chronic myeloid leukemia acquire resistance to ABL tyrosine kinase inhibitors (TKIs), their management remains a challenge. Ponatinib, also known as AP24534, is an oral multi-targeted TKI. Ponatinib is currently being investigated in a pivotal phase 2 clinical trial. In the present study, we analyzed the molecular and functional consequences of ponatinib against imatinib- or nilotinib-resistant (R) K562 and Ba/F3 cells. The proliferation of imatinib- or nilotinib-resistant K562 cells did not decrease after treatment with imatinib or nilotinib. Src family kinase Lyn was activated. Point mutation Ba/F3 cells (E334 V) were also highly resistant to imatinib and nilotinib. Treatment with ponatinib for 72 h inhibited the growth of imatinib- and nilotinib-resistant cells. The phosphorylation of BCR-ABL, Lyn, and Crk-L was reduced. This study demonstrates that ponatinib has an anti-leukemia effect by reducing ABL and Lyn kinase activity and this information may be of therapeutic relevance.

  5. Impact of the clinical use of ROCK inhibitor on the pathogenesis and treatment of glaucoma.

    Science.gov (United States)

    Honjo, Megumi; Tanihara, Hidenobu

    2018-03-01

    Rho-associated protein kinase (ROCK), a ubiquitously expressed signaling messenger and downstream effector of Rho, is activated by several bioactive factors in the aqueous humor (AH). Rho-ROCK signaling regulates a wide spectrum of fundamental cellular events, including cell adhesion, motility, proliferation, differentiation, and apoptosis. Previous studies, including our own, found that ROCK inhibitor lowers intraocular pressure (IOP) via a direct effect on the conventional AH outflow pathway, by regulation of contractile properties, fibrotic activity, and permeability of the trabecular meshwork (TM) and Schlemm's canal (SC) tissues, influencing extracellular matrix (ECM) production. Recently, a novel ROCK inhibitor, ripasudil, has been introduced in Japan. Other ROCK inhibitors are now in clinical trials as new IOP-lowering drugs for glaucoma patients. To date, ripasudil, administered together with other glaucoma medications, has proved safe and efficient in lowering IOP as well as additional effects such as prostaglandin analogs, beta-blockers, and carbonic anhydrase inhibitors, all of which help lower IOP by different mechanisms. In addition, we found that long-term treatment with ripasudil exerted an additional IOP-lowering effect, especially in eyes with high IOP, suggesting that late-onset remodeling of the ECM in glaucomatous eyes may elicit mild and delayed changes in IOP levels. ROCK inhibitors have also shown several additional effects, including increased retinal blood flow, direct protection of neurons against various types of stress, and regulation of wound healing; these benefits may potentially be useful in glaucoma treatment.

  6. The phosphatidylinositol 3-kinase inhibitor, wortmannin, inhibits insulin-induced activation of phosphatidylcholine hydrolysis and associated protein kinase C translocation in rat adipocytes.

    Science.gov (United States)

    Standaert, M L; Avignon, A; Yamada, K; Bandyopadhyay, G; Farese, R V

    1996-02-01

    We questioned whether phosphatidylinositol 3-kinase (PI 3-kinase) and protein kinase C (PKC) function as interrelated signalling mechanisms during insulin action in rat adipocytes. Insulin rapidly activated a phospholipase D that hydrolyses phosphatidylcholine (PC), and this activation was accompanied by increases in diacylglycerol and translocative activation of PKC-alpha and PKC-beta in the plasma membrane. Wortmannin, an apparently specific PI 3-kinase inhibitor, inhibited insulin-stimulated, phospholipase D-dependent PC hydrolysis and subsequent translocation of PKC-alpha and PKC-beta to the plasma membrane. Wortmannin did not inhibit PKC directly in vitro, or the PKC-dependent effects of phorbol esters on glucose transport in intact adipocytes. The PKC inhibitor RO 31-8220 did not inhibit PI 3-kinase directly or its activation in situ by insulin, but inhibited both insulin-stimulated and phorbol ester-stimulated glucose transport. Our findings suggest that insulin acts through PI 3-kinase to activate a PC-specific phospholipase D and causes the translocative activation of PKC-alpha and PKC-beta in plasma membranes of rat adipocytes.

  7. The phosphatidylinositol 3-kinase inhibitor, wortmannin, inhibits insulin-induced activation of phosphatidylcholine hydrolysis and associated protein kinase C translocation in rat adipocytes.

    OpenAIRE

    Standaert, M L; Avignon, A; Yamada, K; Bandyopadhyay, G; Farese, R V

    1996-01-01

    We questioned whether phosphatidylinositol 3-kinase (PI 3-kinase) and protein kinase C (PKC) function as interrelated signalling mechanisms during insulin action in rat adipocytes. Insulin rapidly activated a phospholipase D that hydrolyses phosphatidylcholine (PC), and this activation was accompanied by increases in diacylglycerol and translocative activation of PKC-alpha and PKC-beta in the plasma membrane. Wortmannin, an apparently specific PI 3-kinase inhibitor, inhibited insulin-stimulat...

  8. Prostatic-Like Syndrome in a Woman with Chronic Lymphocytic Leukemia: Sequential Kinase Inhibitor Therapy

    Directory of Open Access Journals (Sweden)

    Diego Velasco-Rodríguez

    2017-01-01

    Full Text Available Chronic lymphocytic leukemia (CLL is an incurable lymphoproliferative disorder with a heterogeneous genetic and clinical course. Two kinase inhibitors, ibrutinib and idelalisib, have demonstrated achievement of complete and durable remissions in relapse/refractory genetically unselected CLL patients. We present a case of relapsed CLL with extensive disease and hourglass deformity of urinary bladder as a result of the compression of two extraperitoneal paravesical soft tissue bulky masses, with excellent response to sequential kinase inhibitor therapy.

  9. RhoB mediates antitumor synergy of combined ixabepilone and sunitinib in human ovarian serous cancer.

    Science.gov (United States)

    Vishnu, Prakash; Colon-Otero, Gerardo; Kennedy, Gregory T; Marlow, Laura A; Kennedy, William P; Wu, Kevin J; Santoso, Joseph T; Copland, John A

    2012-03-01

    The aim was to evaluate antitumor activity of the combination of ixabepilone and sunitinib in pre-clinical models of chemotherapy naïve and refractory epithelial ovarian tumors, and to investigate the mechanism of synergy of such drug combination. HOVTAX2 cell line was derived from a metastatic serous papillary epithelial ovarian tumor (EOC) and a paclitaxel-resistant derivative was established. Dose response curves for ixabepilone and sunitinib were generated and synergy was determined using combination indexes. The molecular mechanism of antitumor synergy was examined using shRNA silencing. The combination of ixabepilone and sunitinib demonstrated robust antitumor synergy in naïve and paclitaxel-resistant HOVTAX2 cell lines due to increased apoptosis. The GTPase, RhoB, was synergistically upregulated in cells treated with ixabepilone and sunitinib. Using shRNA, RhoB was demonstrated to mediate antitumor synergy. These results were validated in two other EOC cell lines. Ixabepilone plus sunitinib demonstrated antitumor synergy via RhoB in naïve and paclitaxel-resistant cells resulting in apoptosis. This study demonstrates a novel mechanism of action leading to antitumor synergy and provides 'proof-of-principle' for combining molecular targeted agents with cytotoxic chemotherapy to improve antitumor efficacy. RhoB could be envisioned as an early biomarker of response to therapy in a planned Phase II clinical trial to assess the efficacy of ixabepilone combined with a receptor tyrosine kinase inhibitor such as sunitinib. To the best of our knowledge, this is the first demonstration of antitumor synergy between these two classes of drugs in EOC and the pivotal role of RhoB in this synergy. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Identification of p38α MAP kinase inhibitors by pharmacophore based virtual screening

    DEFF Research Database (Denmark)

    Gangwal, Rahul P; Das, Nihar R; Thanki, Kaushik

    2014-01-01

    The p38α mitogen-activated protein (MAP) kinase plays a vital role in treating many inflammatory diseases. In the present study, a combined ligand and structure based pharmacophore model was developed to identify potential DFG-in selective p38 MAP kinase inhibitors. Conformations of co...

  11. Combining RNA interference and kinase inhibitors against cell signalling components involved in cancer

    International Nuclear Information System (INIS)

    O'Grady, Michael; Raha, Debasish; Hanson, Bonnie J; Bunting, Michaeline; Hanson, George T

    2005-01-01

    The transcription factor activator protein-1 (AP-1) has been implicated in a large variety of biological processes including oncogenic transformation. The tyrosine kinases of the epidermal growth factor receptor (EGFR) constitute the beginning of one signal transduction cascade leading to AP-1 activation and are known to control cell proliferation and differentiation. Drug discovery efforts targeting this receptor and other pathway components have centred on monoclonal antibodies and small molecule inhibitors. Resistance to such inhibitors has already been observed, guiding the prediction of their use in combination therapies with other targeted agents such as RNA interference (RNAi). This study examines the use of RNAi and kinase inhibitors for qualification of components involved in the EGFR/AP-1 pathway of ME180 cells, and their inhibitory effects when evaluated individually or in tandem against multiple components of this important disease-related pathway. AP-1 activation was assessed using an ME180 cell line stably transfected with a beta-lactamase reporter gene under the control of AP-1 response element following epidermal growth factor (EGF) stimulation. Immunocytochemistry allowed for further quantification of small molecule inhibition on a cellular protein level. RNAi and RT-qPCR experiments were performed to assess the amount of knockdown on an mRNA level, and immunocytochemistry was used to reveal cellular protein levels for the targeted pathway components. Increased potency of kinase inhibitors was shown by combining RNAi directed towards EGFR and small molecule inhibitors acting at proximal or distal points in the pathway. After cellular stimulation with EGF and analysis at the level of AP-1 activation using a β-lactamase reporter gene, a 10–12 fold shift or 2.5–3 fold shift toward greater potency in the IC 50 was observed for EGFR and MEK-1 inhibitors, respectively, in the presence of RNAi targeting EGFR. EGFR pathway components were qualified as

  12. Mesenchymal stem cells are sensitive to treatment with kinase inhibitors and ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nicolay, Nils H.; Debus, Juergen; Huber, Peter E. [Heidelberg University Hospital, Department of Radiation Oncology, Heidelberg (Germany); German Cancer Research Center (dkfz), Department of Molecular and Radiation Oncology, Heidelberg (Germany); Sommer, Eva; Lopez Perez, Ramon; Wirkner, Ute [German Cancer Research Center (dkfz), Department of Molecular and Radiation Oncology, Heidelberg (Germany); Bostel, Tilman [Heidelberg University Hospital, Department of Radiation Oncology, Heidelberg (Germany); Ho, Anthony D.; Saffrich, Rainer [Heidelberg University Hospital, Department of Hematology, Oncology and Rheumatology, Heidelberg (Germany); Lahn, Michael [Lilly Research Laboratories, Oncology Early Clinical Investigation, Indianapolis, IN (United States)

    2014-11-15

    Mesenchymal stem cells (MSCs) can regenerate damaged tissues and may therefore be of importance for normal tissue repair after cancer treatment. Small molecule receptor kinase inhibitors (RKIs) have recently been introduced into cancer treatment. However, the influence of these drugs - particularly in combination with radiotherapy - on the survival of MSCs is largely unknown. The sensitivity of human primary MSCs from healthy volunteers and primary human fibroblast cells to small molecule kinase inhibitors of the vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF) and transforming growth factor β (TGFβ) receptors, as well to inhibitors of c-Kit, was examined in combination with ionizing radiation (IR); cell survival and proliferation were assessed. Expression patterns of different kinase receptors and ligands were investigated using gene arrays. MSCs were highly sensitive to the tyrosine kinase inhibitors SU14816 (imatinib) and SU11657 (sunitinib), but showed only moderate sensitivity to the selective TGFβ receptor 1 inhibitor LY2109761. Primary adult human fibroblasts were comparably resistant to all three inhibitors. The addition of IR had an additive or supra-additive effect in the MSCs, but this was not the case for differentiated fibroblasts. Proliferation was markedly reduced in MSCs following kinase inhibition, both with and without IR. Gene expression analysis revealed high levels of the PDGF α and β receptors, and lower levels of the TGFβ receptor 2 and Abl kinase. IR did not alter the expression of kinase receptors or their respective ligands in either MSCs or adult fibroblasts. These data show that MSCs are highly sensitive to RKIs and combination treatments incorporating IR. Expression analyses suggest that high levels of PDGF receptors may contribute to this effect. (orig.) [German] Mesenchymale Stammzellen (MSCs) koennen die Geweberegeneration unterstuetzen und haben daher moeglicherweise eine Rolle bei der Reparatur

  13. Control of Homeostasis and Dendritic Cell Survival by the GTPase RhoA

    DEFF Research Database (Denmark)

    Li, Shuai; Dislich, Bastian; Brakebusch, Cord H

    2015-01-01

    11b(-)CD8(+) and CD11b(+)Esam(hi) DC subsets, whereas CD11b(+)Esam(lo) DCs were not affected in conditional RhoA-deficient mice. Proteome analyses revealed a defective prosurvival pathway via PI3K/protein kinase B (Akt1)/Bcl-2-associated death promoter in the absence of RhoA. Taken together, our...... findings identify RhoA as a central regulator of DC homeostasis, and its deletion decreases DC numbers below critical thresholds for immune protection and homeostasis, causing aberrant compensatory DC proliferation....

  14. Ang II-AT2R increases mesenchymal stem cell migration by signaling through the FAK and RhoA/Cdc42 pathways in vitro.

    Science.gov (United States)

    Xu, Xiu-Ping; He, Hong-Li; Hu, Shu-Ling; Han, Ji-Bin; Huang, Li-Li; Xu, Jing-Yuan; Xie, Jian-Feng; Liu, Ai-Ran; Yang, Yi; Qiu, Hai-Bo

    2017-07-12

    Mesenchymal stem cells (MSCs) migrate via the bloodstream to sites of injury and are possibly attracted by inflammatory factors. As a proinflammatory mediator, angiotensin II (Ang II) reportedly enhances the migration of various cell types by signaling via the Ang II receptor in vitro. However, few studies have focused on the effects of Ang II on MSC migration and the underlying mechanisms. Human bone marrow MSCs migration was measured using wound healing and Boyden chamber migration assays after treatments with different concentrations of Ang II, an AT1R antagonist (Losartan), and/or an AT2R antagonist (PD-123319). To exclude the effect of proliferation on MSC migration, we measured MSC proliferation after stimulation with the same concentration of Ang II. Additionally, we employed the focal adhesion kinase (FAK) inhibitor PF-573228, RhoA inhibitor C3 transferase, Rac1 inhibitor NSC23766, or Cdc42 inhibitor ML141 to investigate the role of cell adhesion proteins and the Rho-GTPase protein family (RhoA, Rac1, and Cdc42) in Ang II-mediated MSC migration. Cell adhesion proteins (FAK, Talin, and Vinculin) were detected by western blot analysis. The Rho-GTPase family protein activities were assessed by G-LISA and F-actin levels, which reflect actin cytoskeletal organization, were detected by using immunofluorescence. Human bone marrow MSCs constitutively expressed AT1R and AT2R. Additionally, Ang II increased MSC migration in an AT2R-dependent manner. Notably, Ang II-enhanced migration was not mediated by Ang II-mediated cell proliferation. Interestingly, Ang II-enhanced migration was mediated by FAK activation, which was critical for the formation of focal contacts, as evidenced by increased Talin and Vinculin expression. Moreover, RhoA and Cdc42 were activated by FAK to increase cytoskeletal organization, thus promoting cell contraction. Furthermore, FAK, Talin, and Vinculin activation and F-actin reorganization in response to Ang II were prevented by PD-123319 but

  15. Epigenetic Mechanisms Regulating Adaptive Responses to Targeted Kinase Inhibitors in Cancer.

    Science.gov (United States)

    Angus, Steven P; Zawistowski, Jon S; Johnson, Gary L

    2018-01-06

    Although targeted inhibition of oncogenic kinase drivers has achieved remarkable patient responses in many cancers, the development of resistance has remained a significant challenge. Numerous mechanisms have been identified, including the acquisition of gatekeeper mutations, activating pathway mutations, and copy number loss or gain of the driver or alternate nodes. These changes have prompted the development of kinase inhibitors with increased selectivity, use of second-line therapeutics to overcome primary resistance, and combination treatment to forestall resistance. In addition to genomic resistance mechanisms, adaptive transcriptional and signaling responses seen in tumors are gaining appreciation as alterations that lead to a phenotypic state change-often observed as an epithelial-to-mesenchymal shift or reversion to a cancer stem cell-like phenotype underpinned by remodeling of the epigenetic landscape. This epigenomic modulation driving cell state change is multifaceted and includes modulation of repressive and activating histone modifications, DNA methylation, enhancer remodeling, and noncoding RNA species. Consequently, the combination of kinase inhibitors with drugs targeting components of the transcriptional machinery and histone-modifying enzymes has shown promise in preclinical and clinical studies. Here, we review mechanisms of resistance to kinase inhibition in cancer, with special emphasis on the rewired kinome and transcriptional signaling networks and the potential vulnerabilities that may be exploited to overcome these adaptive signaling changes.

  16. cGMP-Dependent Protein Kinase Inhibitors in Health and Disease

    Directory of Open Access Journals (Sweden)

    Jens Schlossmann

    2013-02-01

    Full Text Available cGMP-dependent protein kinases (PKG exhibit diverse physiological functions in the mammalian system e.g., in vascular and gastrointestinal smooth muscles, in platelets, in kidney, in bone growth, nociception and in the central nervous system. Furthermore, PKG were found in insects and in the malaria parasite Plasmodium falciparum. Two different genes of PKG exist: a the PKG-I gene that is expressed as cytosolic PKG-Iα or PKG-Iβ isoform, and b the PKG-II gene, which expresses the membrane associated PKG-II protein. The enzyme kinetics, the localization and the substrates of these PKG enzymes differ utilizing different physiological functions. Various inhibitors of PKG were developed directed against diverse functional regions of the kinase. These inhibitors of PKG have been used to analyse the specific functions of these enzymes. The review article will summarize these different inhibitors regarding their specificity and their present applications in vitro and in vivo. Furthermore, it will be discussed that the distinct inhibition of the PKG enzymes could be used as a valuable pharmacological target e.g., in the treatment of cardiovascular diseases, diarrhea, cancer or malaria.

  17. Identification of a negative regulatory region for the exchange activity and characterization of T332I mutant of Rho guanine nucleotide exchange factor 10 (ARHGEF10).

    Science.gov (United States)

    Chaya, Taro; Shibata, Satoshi; Tokuhara, Yasunori; Yamaguchi, Wataru; Matsumoto, Hiroshi; Kawahara, Ichiro; Kogo, Mikihiko; Ohoka, Yoshiharu; Inagaki, Shinobu

    2011-08-26

    The T332I mutation in Rho guanine nucleotide exchange factor 10 (ARHGEF10) was previously found in persons with slowed nerve conduction velocities and thin myelination of peripheral nerves. However, the molecular and cellular basis of the T332I mutant is not understood. Here, we show that ARHGEF10 has a negative regulatory region in the N terminus, in which residue 332 is located, and the T332I mutant is constitutively active. An N-terminal truncated ARHGEF10 mutant, ARHGEF10 ΔN (lacking amino acids 1-332), induced cell contraction that was inhibited by a Rho kinase inhibitor Y27632 and had higher GEF activity for RhoA than the wild type. The T332I mutant also showed the phenotype similar to the N-terminal truncated mutant. These data suggest that the ARHGEF10 T332I mutation-associated phenotype observed in the peripheral nerves is due to activated GEF activity of the ARHGEF10 T332I mutant.

  18. Identification of a Negative Regulatory Region for the Exchange Activity and Characterization of T332I Mutant of Rho Guanine Nucleotide Exchange Factor 10 (ARHGEF10)*

    Science.gov (United States)

    Chaya, Taro; Shibata, Satoshi; Tokuhara, Yasunori; Yamaguchi, Wataru; Matsumoto, Hiroshi; Kawahara, Ichiro; Kogo, Mikihiko; Ohoka, Yoshiharu; Inagaki, Shinobu

    2011-01-01

    The T332I mutation in Rho guanine nucleotide exchange factor 10 (ARHGEF10) was previously found in persons with slowed nerve conduction velocities and thin myelination of peripheral nerves. However, the molecular and cellular basis of the T332I mutant is not understood. Here, we show that ARHGEF10 has a negative regulatory region in the N terminus, in which residue 332 is located, and the T332I mutant is constitutively active. An N-terminal truncated ARHGEF10 mutant, ARHGEF10 ΔN (lacking amino acids 1–332), induced cell contraction that was inhibited by a Rho kinase inhibitor Y27632 and had higher GEF activity for RhoA than the wild type. The T332I mutant also showed the phenotype similar to the N-terminal truncated mutant. These data suggest that the ARHGEF10 T332I mutation-associated phenotype observed in the peripheral nerves is due to activated GEF activity of the ARHGEF10 T332I mutant. PMID:21719701

  19. Erkitinib, a novel EGFR tyrosine kinase inhibitor screened using a ProteoChip system from a phytochemical library

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eung-Yoon; Choi, Young-Jin [Biochip Research Center, Hoseo University, Asan 336-795 (Korea, Republic of); Innopharmascreen, Inc., Asan 336-795 (Korea, Republic of); Park, Chan-Won [Biochip Research Center, Hoseo University, Asan 336-795 (Korea, Republic of); Dept. of Biological Science, Hoseo University, Asan 336-795 (Korea, Republic of); Kang, In-Cheol, E-mail: ickang@hoseo.edu [Biochip Research Center, Hoseo University, Asan 336-795 (Korea, Republic of); Dept. of Biological Science, Hoseo University, Asan 336-795 (Korea, Republic of); Innopharmascreen, Inc., Asan 336-795 (Korea, Republic of)

    2009-11-20

    Receptor tyrosine kinases (PTKs) play key roles in the pathogenesis of numerous human diseases, including cancer. Therefore PTK inhibitors are currently under intensive investigation as potential drug candidates. Herein, we report on a ProteoChip-based screening of an epidermal growth factor receptor (EGFR) tyrosine kinase (TK) inhibitor, Erkitinibs, from phytochemical libraries. PLC-{gamma}-1 was used as a substrate immobilized on a ProteoChip and incubated with an EGFR kinase to phosphorylate tyrosine residues of the substrate, followed by a fluorescence detection of the substrate recognized by a phospho-specific monoclonal antibody. Erkitinibs inhibited HeLa cell proliferation in a dose-dependent manner. In conclusion, these data suggest that Erkitinibs can be a specific inhibitor of an EGFR kinase and can be further developed as a potent anti-tumor agent.

  20. Erkitinib, a novel EGFR tyrosine kinase inhibitor screened using a ProteoChip system from a phytochemical library

    International Nuclear Information System (INIS)

    Kim, Eung-Yoon; Choi, Young-Jin; Park, Chan-Won; Kang, In-Cheol

    2009-01-01

    Receptor tyrosine kinases (PTKs) play key roles in the pathogenesis of numerous human diseases, including cancer. Therefore PTK inhibitors are currently under intensive investigation as potential drug candidates. Herein, we report on a ProteoChip-based screening of an epidermal growth factor receptor (EGFR) tyrosine kinase (TK) inhibitor, Erkitinibs, from phytochemical libraries. PLC-γ-1 was used as a substrate immobilized on a ProteoChip and incubated with an EGFR kinase to phosphorylate tyrosine residues of the substrate, followed by a fluorescence detection of the substrate recognized by a phospho-specific monoclonal antibody. Erkitinibs inhibited HeLa cell proliferation in a dose-dependent manner. In conclusion, these data suggest that Erkitinibs can be a specific inhibitor of an EGFR kinase and can be further developed as a potent anti-tumor agent.

  1. The ionizing radiation inducible gene PARX/ARAP2 participates in Rho and ARF signaling

    International Nuclear Information System (INIS)

    Wong, J.A.; Chen, Z.; Zhao, Y.; Vallis, K.A.; Marignani, P.A.; Randazzo, P.A.

    2003-01-01

    Full text: PARX/ARAP2 is a novel protein that we identified in a gene trap screen for ionizing radiation (IR)-regulated genes. It belongs to a recently described family of proteins that link Rho, ADP-ribosilation factor (ARF) and phosphoinositide 3-kinase (PI3-K) signaling. We have cloned the full length human PARX. Domain analysis of the predicted protein revealed a sterile-alpha motif, five pleckstrin homology domains, a RhoGTPase activating domain (RhoGAP) and an ARF activating domain (ARFGAP). PARX is early inducible by IR in a dose-dependent manner in murine ES cells and in several human B-cell lymphoma lines with up to six-fold induction at the mRNA level at 2 hours (10 Gy). Thus, the kinetics of PARX induction follows the pattern of the rapid response typical of many stress-induced immediate-early genes. PARX expression is also induced in response to other cellular stressors including sorbitol and bleomycin. PARX induction is dependent on PI3-K activity and can be suppressed by the PI3-K inhibitor LY294002. Induction of PARX in response to IR has been observed in cell lines that are p53 mutant indicating up-regulation independent of normal p53 function. The role of p53 in PARX induction is currently being studied using cell lines expressing temperature sensitive p53. Biochemical studies reveal that human PARX has in vivo RhoGAP activity for Rac1 and phosphatidylinositol 3,4,5-trisphosphate dependent ARFGAP activity for ARF1, ARF5 and ARF6. Also, temporal changes in PARX cellular localization following IR are currently being investigated using confocal microscopy. PARX is a gene with a potential role in the cellular response to genotoxic stress, and may illuminate the currently unclear role the small GTPases Rho and ARF play in the radiation response

  2. Activity of dual SRC-ABL inhibitors highlights the role of BCR/ABL kinase dynamics in drug resistance

    Science.gov (United States)

    Azam, Mohammad; Nardi, Valentina; Shakespeare, William C.; Metcalf, Chester A.; Bohacek, Regine S.; Wang, Yihan; Sundaramoorthi, Raji; Sliz, Piotr; Veach, Darren R.; Bornmann, William G.; Clarkson, Bayard; Dalgarno, David C.; Sawyer, Tomi K.; Daley, George Q.

    2006-01-01

    Mutation in the ABL kinase domain is the principal mechanism of imatinib resistance in patients with chronic myelogenous leukemia. Many mutations favor active kinase conformations that preclude imatinib binding. Because the active forms of ABL and SRC resemble one another, we tested two dual SRC-ABL kinase inhibitors, AP23464 and PD166326, against 58 imatinib-resistant (IMR) BCR/ABL kinase variants. Both compounds potently inhibit most IMR variants, and in vitro drug selection demonstrates that active (AP23464) and open (PD166326) conformation-specific compounds are less susceptible to resistance than imatinib. Combinations of inhibitors suppressed essentially all resistance mutations, with the notable exception of T315I. Guided by mutagenesis studies and molecular modeling, we designed a series of AP23464 analogues to target T315I. The analogue AP23846 inhibited both native and T315I variants of BCR/ABL with submicromolar potency but showed nonspecific cellular toxicity. Our data illustrate how conformational dynamics of the ABL kinase accounts for the activity of dual SRC-ABL inhibitors against IMR-mutants and provides a rationale for combining conformation specific inhibitors to suppress resistance. PMID:16754879

  3. Intra-ocular pressure-lowering effects of a Rho kinase inhibitor, ripasudil (K-115), over 24 hours in primary open-angle glaucoma and ocular hypertension: a randomized, open-label, crossover study.

    Science.gov (United States)

    Tanihara, Hidenobu; Inoue, Toshihiro; Yamamoto, Tetsuya; Kuwayama, Yasuaki; Abe, Haruki; Suganami, Hideki; Araie, Makoto

    2015-06-01

    To investigate the intra-ocular pressure (IOP)-lowering effects of a selective Rho kinase inhibitor, ripasudil (K-115), over 24 hr in patients with primary open-angle glaucoma (POAG) or ocular hypertension (OHT). In this multicenter, prospective, randomized, open-label, 3-period, Latin-square crossover clinical study, 28 patients with POAG or OHT whose IOP level was 21 mmHg or higher were subdivided into three groups. Each patient was treated with placebo and ripasudil in concentrations of 0.2 and 0.4%, at 9:00 and 21:00 on day 1 through a total of 3 periods separated by washout periods. IOP was measured at 9:00, 10:00, 11:00, 13:00, 16:00, 19:00, 21:00, 22:00 and 23:00 on day 1, and 1:00, 4:00, 7:00 and 9:00 on day 2 in sitting position using Goldmann applanation tonometer. Main outcome measure was the IOP reduction of placebo and ripasudil from baseline. The mean IOP reduction was -5.2 mmHg for 0.2%, -6.4 mmHg for 0.4% and -2.0 mmHg for placebo at 2 hr after the first instillation. Also, the corresponding values were -6.8 mmHg for 0.2%, -7.3 mmHg for 0.4% and -4.1 mmHg for placebo at 2 hr after the second instillation. Statistically significant IOP reduction, compared with placebo, was found for both 0.2 and 0.4% from 1 through 7 hr after each instillation. In safety, conjunctival hyperaemia was observed in 22 patients (79%) for 0.2%, 27 patients (96%) for 0.4% and three patients (11%) for placebo. Ripasudil is a promising new topical medication to lower IOP for at least 7 hr after instillations in patients with POAG or OHT. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  4. Structural Bioinformatics-Based Prediction of Exceptional Selectivity of p38 MAP Kinase Inhibitor PH-797804

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Li; Shieh, Huey S.; Selness, Shaun R.; Devraj, Rajesh V.; Walker, John K.; Devadas, Balekudru; Hope, Heidi R.; Compton, Robert P.; Schindler, John F.; Hirsch, Jeffrey L.; Benson, Alan G.; Kurumbail, Ravi G.; Stegeman, Roderick A.; Williams, Jennifer M.; Broadus, Richard M.; Walden, Zara; Monahan, Joseph B.; Pfizer

    2009-07-24

    PH-797804 is a diarylpyridinone inhibitor of p38{alpha} mitogen-activated protein (MAP) kinase derived from a racemic mixture as the more potent atropisomer (aS), first proposed by molecular modeling and subsequently confirmed by experiments. On the basis of structural comparison with a different biaryl pyrazole template and supported by dozens of high-resolution crystal structures of p38{alpha} inhibitor complexes, PH-797804 is predicted to possess a high level of specificity across the broad human kinase genome. We used a structural bioinformatics approach to identify two selectivity elements encoded by the TXXXG sequence motif on the p38{alpha} kinase hinge: (i) Thr106 that serves as the gatekeeper to the buried hydrophobic pocket occupied by 2,4-difluorophenyl of PH-797804 and (ii) the bidentate hydrogen bonds formed by the pyridinone moiety with the kinase hinge requiring an induced 180{sup o} rotation of the Met109-Gly110 peptide bond. The peptide flip occurs in p38{alpha} kinase due to the critical glycine residue marked by its conformational flexibility. Kinome-wide sequence mining revealed rare presentation of the selectivity motif. Corroboratively, PH-797804 exhibited exceptionally high specificity against MAP kinases and the related kinases. No cross-reactivity was observed in large panels of kinase screens (selectivity ratio of >500-fold). In cellular assays, PH-797804 demonstrated superior potency and selectivity consistent with the biochemical measurements. PH-797804 has met safety criteria in human phase I studies and is under clinical development for several inflammatory conditions. Understanding the rationale for selectivity at the molecular level helps elucidate the biological function and design of specific p38{alpha} kinase inhibitors.

  5. Kinase-dead ATM protein is highly oncogenic and can be preferentially targeted by Topo-isomerase I inhibitors.

    Science.gov (United States)

    Yamamoto, Kenta; Wang, Jiguang; Sprinzen, Lisa; Xu, Jun; Haddock, Christopher J; Li, Chen; Lee, Brian J; Loredan, Denis G; Jiang, Wenxia; Vindigni, Alessandro; Wang, Dong; Rabadan, Raul; Zha, Shan

    2016-06-15

    Missense mutations in ATM kinase, a master regulator of DNA damage responses, are found in many cancers, but their impact on ATM function and implications for cancer therapy are largely unknown. Here we report that 72% of cancer-associated ATM mutations are missense mutations that are enriched around the kinase domain. Expression of kinase-dead ATM (Atm(KD/-)) is more oncogenic than loss of ATM (Atm(-/-)) in mouse models, leading to earlier and more frequent lymphomas with Pten deletions. Kinase-dead ATM protein (Atm-KD), but not loss of ATM (Atm-null), prevents replication-dependent removal of Topo-isomerase I-DNA adducts at the step of strand cleavage, leading to severe genomic instability and hypersensitivity to Topo-isomerase I inhibitors. Correspondingly, Topo-isomerase I inhibitors effectively and preferentially eliminate Atm(KD/-), but not Atm-proficientor Atm(-/-) leukemia in animal models. These findings identify ATM kinase-domain missense mutations as a potent oncogenic event and a biomarker for Topo-isomerase I inhibitor based therapy.

  6. Discovery of potent 1H-imidazo[4,5-b]pyridine-based c-Met kinase inhibitors via mechanism-directed structural optimization.

    Science.gov (United States)

    An, Xiao-De; Liu, Hongyan; Xu, Zhong-Liang; Jin, Yi; Peng, Xia; Yao, Ying-Ming; Geng, Meiyu; Long, Ya-Qiu

    2015-02-01

    Starting from our previously identified novel c-Met kinase inhibitors bearing 1H-imidazo[4,5-h][1,6]naphthyridin-2(3H)-one scaffold, a global structural exploration was conducted to furnish an optimal binding motif for further development, directed by the enzyme inhibitory mechanism. First round SAR study picked two imidazonaphthyridinone frameworks with 1,8- and 3,5-disubstitution pattern as class I and class II c-Met kinase inhibitors, respectively. Further structural optimization on type II inhibitors by truncation of the imidazonaphthyridinone core and incorporation of an N-phenyl cyclopropane-1,1-dicarboxamide pharmacophore led to the discovery of novel imidazopyridine-based c-Met kinase inhibitors, displaying nanomolar enzyme inhibitory activity and improved Met kinase selectivity. More significantly, the new chemotype c-Met kinase inhibitors effectively inhibited Met phosphorylation and its downstream signaling as well as the proliferation of Met-dependent EBC-1 human lung cancer cells at submicromolar concentrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Oncogenic Kinase Bcr-Abl and Its Resistance to Pharmacological Inhibitors

    Czech Academy of Sciences Publication Activity Database

    Kryštof, Vladimír

    2008-01-01

    Roč. 102, č. 9 (2008), s. 795-800 E-ISSN 1213-7103 Institutional research plan: CEZ:AV0Z50380511 Keywords : imatinib * inhibitor * chronic myeloid leukaemia * kinase * cancer Subject RIV: CE - Biochemistry www.chemicke-listy.cz/docs/full/2008_09_795-800.pdf

  8. AMP-activated protein kinase induces actin cytoskeleton reorganization in epithelial cells

    International Nuclear Information System (INIS)

    Miranda, Lisa; Carpentier, Sarah; Platek, Anna; Hussain, Nusrat; Gueuning, Marie-Agnes; Vertommen, Didier; Ozkan, Yurda; Sid, Brice; Hue, Louis; Courtoy, Pierre J.; Rider, Mark H.; Horman, Sandrine

    2010-01-01

    AMP-activated protein kinase (AMPK), a known regulator of cellular and systemic energy balance, is now recognized to control cell division, cell polarity and cell migration, all of which depend on the actin cytoskeleton. Here we report the effects of A769662, a pharmacological activator of AMPK, on cytoskeletal organization and signalling in epithelial Madin-Darby canine kidney (MDCK) cells. We show that AMPK activation induced shortening or radiation of stress fibers, uncoupling from paxillin and predominance of cortical F-actin. In parallel, Rho-kinase downstream targets, namely myosin regulatory light chain and cofilin, were phosphorylated. These effects resembled the morphological changes in MDCK cells exposed to hyperosmotic shock, which led to Ca 2+ -dependent AMPK activation via calmodulin-dependent protein kinase kinase-β(CaMKKβ), a known upstream kinase of AMPK. Indeed, hypertonicity-induced AMPK activation was markedly reduced by the STO-609 CaMKKβ inhibitor, as was the increase in MLC and cofilin phosphorylation. We suggest that AMPK links osmotic stress to the reorganization of the actin cytoskeleton.

  9. Identification of hematein as a novel inhibitor of protein kinase CK2 from a natural product library

    International Nuclear Information System (INIS)

    Hung, Ming-Szu; Xu, Zhidong; Lin, Yu-Ching; Mao, Jian-Hua; Yang, Cheng-Ta; Chang, Pey-Jium; Jablons, David M; You, Liang

    2009-01-01

    Casein kinase 2 (CK2) is dysregulated in various human cancers and is a promising target for cancer therapy. To date, there is no small molecular CK2 inhibitor in clinical trial yet. With the aim to identify novel CK2 inhibitors, we screened a natural product library. We adopted cell-based proliferation and CK2 kinase assays to screen CK2 inhibitors from a natural compound library. Dose-dependent response of CK2 inhibitors in vitro was determined by a radioisotope kinase assay. Western blot analysis was used to evaluate down stream Akt phosphorylation and apoptosis. Apoptosis was also evaluated by annexin-V/propidium iodide (PI) labeling method using flow cytometry. Inhibition effects of CK2 inhibitors on the growth of cancer and normal cells were evaluated by cell proliferation and viability assays. Hematein was identified as a novel CK2 inhibitor that is highly selective among a panel of kinases. It appears to be an ATP non-competitive and partially reversible CK2 inhibitor with an IC 50 value of 0.55 μM. In addition, hematein inhibited cancer cell growth partially through down-regulation of Akt phosphorylation and induced apoptosis in these cells. Furthermore, hematein exerted stronger inhibition effects on the growth of cancer cells than in normal cells. In this study, we showed that hematein is a novel selective and cell permeable small molecule CK2 inhibitor. Hematein showed stronger growth inhibition effects to cancer cells when compared to normal cells. This compound may represent a promising class of CK2 inhibitors

  10. Switch control pocket inhibitors of p38-MAP kinase. Durable type II inhibitors that do not require binding into the canonical ATP hinge region.

    Science.gov (United States)

    Ahn, Yu Mi; Clare, Michael; Ensinger, Carol L; Hood, Molly M; Lord, John W; Lu, Wei-Ping; Miller, David F; Patt, William C; Smith, Bryan D; Vogeti, Lakshminarayana; Kaufman, Michael D; Petillo, Peter A; Wise, Scott C; Abendroth, Jan; Chun, Lawrence; Clark, Robin; Feese, Michael; Kim, Hidong; Stewart, Lance; Flynn, Daniel L

    2010-10-01

    Switch control pocket inhibitors of p38-alpha kinase are described. Durable type II inhibitors were designed which bind to arginines (Arg67 or Arg70) that function as key residues for mediating phospho-threonine 180 dependant conformational fluxing of p38-alpha from an inactive type II state to an active type I state. Binding to Arg70 in particular led to potent inhibitors, exemplified by DP-802, which also exhibited high kinase selectivity. Binding to Arg70 obviated the requirement for binding into the ATP Hinge region. X-ray crystallography revealed that DP-802 and analogs induce an enhanced type II conformation upon binding to either the unphosphorylated or the doubly phosphorylated form of p38-alpha kinase. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Small Molecule Tyrosine Kinase Inhibitors of ErbB2/HER2/Neu in the Treatment of Aggressive Breast Cancer

    Directory of Open Access Journals (Sweden)

    Richard L. Schroeder

    2014-09-01

    Full Text Available The human epidermal growth factor receptor 2 (HER2 is a member of the erbB class of tyrosine kinase receptors. These proteins are normally expressed at the surface of healthy cells and play critical roles in the signal transduction cascade in a myriad of biochemical pathways responsible for cell growth and differentiation. However, it is widely known that amplification and subsequent overexpression of the HER2 encoding oncogene results in unregulated cell proliferation in an aggressive form of breast cancer known as HER2-positive breast cancer. Existing therapies such as trastuzumab (Herceptin® and lapatinib (Tyverb/Tykerb®, a monoclonal antibody inhibitor and a dual EGFR/HER2 kinase inhibitor, respectively, are currently used in the treatment of HER2-positive cancers, although issues with high recurrence and acquired resistance still remain. Small molecule tyrosine kinase inhibitors provide attractive therapeutic targets, as they are able to block cell signaling associated with many of the proposed mechanisms for HER2 resistance. In this regard we aim to present a review on the available HER2 tyrosine kinase inhibitors, as well as those currently in development. The use of tyrosine kinase inhibitors as sequential or combinatorial therapeutic strategies with other HER family inhibitors is also discussed.

  12. p21-Activated kinase (PAK regulates cytoskeletal reorganization and directional migration in human neutrophils.

    Directory of Open Access Journals (Sweden)

    Asako Itakura

    Full Text Available Neutrophils serve as a first line of defense in innate immunity owing in part to their ability to rapidly migrate towards chemotactic factors derived from invading pathogens. As a migratory function, neutrophil chemotaxis is regulated by the Rho family of small GTPases. However, the mechanisms by which Rho GTPases orchestrate cytoskeletal dynamics in migrating neutrophils remain ill-defined. In this study, we characterized the role of p21-activated kinase (PAK downstream of Rho GTPases in cytoskeletal remodeling and chemotactic processes of human neutrophils. We found that PAK activation occurred upon stimulation of neutrophils with f-Met-Leu-Phe (fMLP, and PAK accumulated at the actin-rich leading edge of stimulated neutrophils, suggesting a role for PAK in Rac-dependent actin remodeling. Treatment with the pharmacological PAK inhibitor, PF3758309, abrogated the integrity of RhoA-mediated actomyosin contractility and surface adhesion. Moreover, inhibition of PAK activity impaired neutrophil morphological polarization and directional migration under a gradient of fMLP, and was associated with dysregulated Ca(2+ signaling. These results suggest that PAK serves as an important effector of Rho-family GTPases in neutrophil cytoskeletal reorganization, and plays a key role in driving efficient directional migration of human neutrophils.

  13. Photoactivatable Caged Prodrugs of VEGFR-2 Kinase Inhibitors

    OpenAIRE

    Boris Pinchuk; Rebecca Horbert; Alexander Döbber; Lydia Kuhl; Christian Peifer

    2016-01-01

    In this study, we report on the design, synthesis, photokinetic properties and in vitro evaluation of photoactivatable caged prodrugs for the receptor tyrosine kinase VEGFR-2. Highly potent VEGFR-2 inhibitors 1 and 3 were caged by introduction of a photoremovable protecting group (PPG) to yield the caged prodrugs 4 and 5. As expected, enzymatic and cellular proliferation assays showed dramatically diminished efficacy of caged prodrugs in vitro. Upon ultraviolet (UV) irradiation of the prodrug...

  14. The activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 to the distal CCAAT box of the RhoB promoter

    International Nuclear Information System (INIS)

    Ahn, Jiwon; Choi, Jeong-Hae; Won, Misun; Kang, Chang-Mo; Gyun, Mi-Rang; Park, Hee-Moon; Kim, Chun-Ho; Chung, Kyung-Sook

    2011-01-01

    Highlights: → Regulation of transcriptional activation of RhoB is still unclear. → We examine the effect of p38 MAPK inhibition, and c-Jun and RhoB depletion on UV-induced RhoB expression and apoptosis. → We identify the regions of RhoB promoter necessary to confer UV responsiveness using pRhoB-luciferase reporter assays. → c-Jun, ATF2 and p300 are dominantly associated with NF-Y on the distal CCAAT box. → The activation of p38 MAPK primarily contribute to UV-induced RhoB expression by recruiting the c-Jun and p300 proteins on distal CCAAT box of RhoB promoter. -- Abstract: The Ras-related small GTP-binding protein RhoB is rapidly induced in response to genotoxic stresses caused by ionizing radiation. It is known that UV-induced RhoB expression results from the binding of activating transcription factor 2 (ATF2) via NF-Y to the inverted CCAAT box (-23) of the RhoB promoter. Here, we show that the association of c-Jun with the distal CCAAT box (-72) is primarily involved in UV-induced RhoB expression and p38 MAPK regulated RhoB induction through the distal CCAAT box. UV-induced RhoB expression and apoptosis were markedly attenuated by pretreatment with the p38 MAPK inhibitor. siRNA knockdown of RhoB, ATF2 and c-Jun resulted in decreased RhoB expression and eventually restored the growth of UV-irradiated Jurkat cells. In the reporter assay using luciferase under the RhoB promoter, inhibition of RhoB promoter activity by the p38 inhibitor and knockdown of c-Jun using siRNA occurred through the distal CCAAT box. Immunoprecipitation and DNA affinity protein binding assays revealed the association of c-Jun and p300 via NF-YA and the dissociation of histone deacetylase 1 (HDAC1) via c-Jun recruitment to the CCAAT boxes of the RhoB promoter. These results suggest that the activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 proteins to the distal CCAAT box of the RhoB promoter in Jurkat cells.

  15. RhoA-Mediated Functions in C3H10T1/2 Osteoprogenitors Are Substrate Topography Dependent.

    Science.gov (United States)

    Ogino, Yoichiro; Liang, Ruiwei; Mendonça, Daniela B S; Mendonça, Gustavo; Nagasawa, Masako; Koyano, Kiyoshi; Cooper, Lyndon F

    2016-03-01

    Surface topography broadly influences cellular responses. Adherent cell activities are regulated, in part, by RhoA, a member of the Rho-family of GTPases. In this study, we evaluated the influence of surface topography on RhoA activity and associated cellular functions. The murine mesenchymal stem cell line C3H10T1/2 cells (osteoprogenitor cells) were cultured on titanium substrates with smooth topography (S), microtopography (M), and nanotopography (N) to evaluate the effect of surface topography on RhoA-mediated functions (cell spreading, adhesion, migration, and osteogenic differentiation). The influence of RhoA activity in the context of surface topography was also elucidated using RhoA pharmacologic inhibitor. Following adhesion, M and N adherent cells developed multiple projections, while S adherent cells had flattened and widespread morphology. RhoA inhibitor induced remarkable longer and thinner cytoplasmic projections on all surfaces. Cell adhesion and osteogenic differentiation was topography dependent with S topography roughness dependent (S topography. Smooth surface adherent cells appear highly sensitive to RhoA function, while nano-scale topography adherent cell may utilize alternative cellular signaling pathway(s) to influence adherent cellular functions regardless of RhoA activity. © 2015 Wiley Periodicals, Inc.

  16. QSAR, molecular docking studies of thiophene and imidazopyridine derivatives as polo-like kinase 1 inhibitors

    Science.gov (United States)

    Cao, Shandong

    2012-08-01

    The purpose of the present study was to develop in silico models allowing for a reliable prediction of polo-like kinase inhibitors based on a large diverse dataset of 136 compounds. As an effective method, quantitative structure activity relationship (QSAR) was applied using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). The proposed QSAR models showed reasonable predictivity of thiophene analogs (Rcv2=0.533, Rpred2=0.845) and included four molecular descriptors, namely IC3, RDF075m, Mor02m and R4e+. The optimal model for imidazopyridine derivatives (Rcv2=0.776, Rpred2=0.876) was shown to perform good in prediction accuracy, using GATS2m and BEHe1 descriptors. Analysis of the contour maps helped to identify structural requirements for the inhibitors and served as a basis for the design of the next generation of the inhibitor analogues. Docking studies were also employed to position the inhibitors into the polo-like kinase active site to determine the most probable binding mode. These studies may help to understand the factors influencing the binding affinity of chemicals and to develop alternative methods for prescreening and designing of polo-like kinase inhibitors.

  17. Involvement of RhoA/Rho kinase signaling in VEGF-induced endothelial cell migration and angiogenesis in vitro

    NARCIS (Netherlands)

    Nieuw Amerongen, G.P. van; Koolwijk, P.; Versteilen, A.; Hinsbergh, V.W.M. van

    2003-01-01

    Objective - Growth factor-induced angiogenesis involves migration of endothelial cells (ECs) into perivascular areas and requires active remodeling of the endothelial F-actin cytoskeleton. The small GTPase RhoA previously has been implicated in vascular endothelial growth factor (VEGF)-induced

  18. Grb2 mediates semaphorin-4D-dependent RhoA inactivation.

    Science.gov (United States)

    Sun, Tianliang; Krishnan, Rameshkumar; Swiercz, Jakub M

    2012-08-01

    Signaling through the semaphorin 4D (Sema4D) receptor plexin-B1 is modulated by its interaction with tyrosine kinases ErbB-2 and Met. In cells expressing the plexin-B1-ErbB-2 receptor complex, ligand stimulation results in the activation of small GTPase RhoA and stimulation of cellular migration. By contrast, in cells expressing plexin-B1 and Met, ligand stimulation results in an association with the RhoGTPase-activating protein p190 RhoGAP and subsequent RhoA inactivation--a process that involves the tyrosine phosphorylation of plexin-B1 by Met. Inactivation of RhoA is necessary for Sema4D-mediated inhibition of cellular migration. It is, however, unknown how plexin-B1 phosphorylation regulates RhoGAP interaction and activity. Here we show that the activation of plexin-B1 by Sema4D and its subsequent tyrosine phosphorylation by Met creates a docking site for the SH2 domain of growth factor receptor bound-2 (Grb2). Grb2 is thereby recruited into the plexin-B1 receptor complex and, through its SH3 domain, interacts with p190 RhoGAP and mediates RhoA deactivation. Phosphorylation of plexin-B1 by Met and the recruitment of Grb2 have no effect on the R-RasGAP activity of plexin-B1, but are required for Sema4D-induced, RhoA-dependent antimigratory effects of Sema4D on breast cancer cells. These data show Grb2 as a direct link between plexin and p190-RhoGAP-mediated downstream signaling.

  19. Virtual screening filters for the design of type II p38 MAP kinase inhibitors: a fragment based library generation approach.

    Science.gov (United States)

    Badrinarayan, Preethi; Sastry, G Narahari

    2012-04-01

    In this work, we introduce the development and application of a three-step scoring and filtering procedure for the design of type II p38 MAP kinase leads using allosteric fragments extracted from virtual screening hits. The design of the virtual screening filters is based on a thorough evaluation of docking methods, DFG-loop conformation, binding interactions and chemotype specificity of the 138 p38 MAP kinase inhibitors from Protein Data Bank bound to DFG-in and DFG-out conformations using Glide, GOLD and CDOCKER. A 40 ns molecular dynamics simulation with the apo, type I with DFG-in and type II with DFG-out forms was carried out to delineate the effects of structural variations on inhibitor binding. The designed docking-score and sub-structure filters were first tested on a dataset of 249 potent p38 MAP kinase inhibitors from seven diverse series and 18,842 kinase inhibitors from PDB, to gauge their capacity to discriminate between kinase and non-kinase inhibitors and likewise to selectively filter-in target-specific inhibitors. The designed filters were then applied in the virtual screening of a database of ten million (10⁷) compounds resulting in the identification of 100 hits. Based on their binding modes, 98 allosteric fragments were extracted from the hits and a fragment library was generated. New type II p38 MAP kinase leads were designed by tailoring the existing type I ATP site binders with allosteric fragments using a common urea linker. Target specific virtual screening filters can thus be easily developed for other kinases based on this strategy to retrieve target selective compounds. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. [Recent Advances and Prospect of Advanced Non-small Cell Lung Cancer Targeted 
Therapy: Focus on Small Molecular Tyrosine Kinase Inhibitors].

    Science.gov (United States)

    Zhang, Guowei; Wang, Huijuan; Ma, Zhiyong

    2017-04-20

    At present the treatment of advanced non-small cell lung cancer enters a targeted era and develops rapidly. New drugs appear constantly. Small molecular tyrosine kinase inhibitors have occupied the biggest piece of the territory, which commonly have a clear biomarker as predictor, and show remarkable effect in specific molecular classification of patients. The epidermal growth factor tyrosine kinase inhibitors such as gefitinib, erlotinib, icotinib and anaplastic lymphoma kinase tyrosine kinase inhibitors crizotinib have brought a milestone advance. In recent years new generations of tyrosine kinase inhibitors have achieved a great success in patients with acquired resistance to the above two kinds of drugs. At the same time new therapeutic targets are constantly emerging. So in this paper, we reviewed and summarized the important drugs and clinical trails on this topic, and made a prospect of the future development.

  1. Recent Advances and Prospect of Advanced Non-small Cell Lung Cancer Targeted 
Therapy: Focus on Small Molecular Tyrosine Kinase Inhibitors

    Directory of Open Access Journals (Sweden)

    Guowei ZHANG

    2017-04-01

    Full Text Available At present the treatment of advanced non-small cell lung cancer enters a targeted era and develops rapidly. New drugs appear constantly. Small molecular tyrosine kinase inhibitors have occupied the biggest piece of the territory, which commonly have a clear biomarker as predictor, and show remarkable effect in specific molecular classification of patients. The epidermal growth factor tyrosine kinase inhibitors such as gefitinib, erlotinib, icotinib and anaplastic lymphoma kinase tyrosine kinase inhibitors crizotinib have brought a milestone advance. In recent years new generations of tyrosine kinase inhibitors have achieved a great success in patients with acquired resistance to the above two kinds of drugs. At the same time new therapeutic targets are constantly emerging. So in this paper, we reviewed and summarized the important drugs and clinical trails on this topic, and made a prospect of the future development.

  2. Substance P enhances tissue factor release from granulocyte-macrophage colony-stimulating factor-dependent macrophages via the p22phox/β-arrestin 2/Rho A signaling pathway.

    Science.gov (United States)

    Yamaguchi, Rui; Yamamoto, Takatoshi; Sakamoto, Arisa; Ishimaru, Yasuji; Narahara, Shinji; Sugiuchi, Hiroyuki; Yamaguchi, Yasuo

    2016-03-01

    Granulocyte-macrophage colony stimulating factor (GM-CSF) induces procoagulant activity of macrophages. Tissue factor (TF) is a membrane-bound glycoprotein and substance P (SP) is a pro-inflammatory neuropeptide involved in the formation of membrane blebs. This study investigated the role of SP in TF release by GM-CSF-dependent macrophages. SP significantly decreased TF levels in whole-cell lysates of GM-CSF-dependent macrophages. TF was detected in the culture supernatant by enzyme-linked immunosorbent assay after stimulation of macrophages by SP. Aprepitant (an SP/neurokinin 1 receptor antagonist) reduced TF release from macrophages stimulated with SP. Pretreatment of macrophages with a radical scavenger(pyrrolidinedithiocarbamate) also limited the decrease of TF in whole-cell lysates after stimulation with SP. A protein kinase C inhibitor (rottlerin) partially blocked this macrophage response to SP, while it was significantly inhibited by a ROCK inhibitor (Y-27632) or a dynamin inhibitor (dinasore). An Akt inhibitor (perifosine) also partially blocked this response. Furthermore, siRNA targeting p22phox, β-arrestin 2, or Rho A, blunted the release of TF from macrophages stimulated with SP. In other experiments, visceral adipocytes derived from cryopreserved preadipocytes were found to produce SP. In conclusion, SP enhances the release of TF from macrophages via the p22phox/β-arrestin 2/Rho A signaling pathway. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Discovery and Characterization of Non-ATP Site Inhibitors of the Mitogen Activated Protein (MAP) Kinases

    Energy Technology Data Exchange (ETDEWEB)

    Comess, Kenneth M.; Sun, Chaohong; Abad-Zapatero, Cele; Goedken, Eric R.; Gum, Rebecca J.; Borhani, David W.; Argiriadi, Maria; Groebe, Duncan R.; Jia, Yong; Clampit, Jill E.; Haasch, Deanna L.; Smith, Harriet T.; Wang, Sanyi; Song, Danying; Coen, Michael L.; Cloutier, Timothy E.; Tang, Hua; Cheng, Xueheng; Quinn, Christopher; Liu, Bo; Xin, Zhili; Liu, Gang; Fry, Elizabeth H.; Stoll, Vincent; Ng, Teresa I.; Banach, David; Marcotte, Doug; Burns, David J.; Calderwood, David J.; Hajduk, Philip J. (Abbott)

    2012-03-02

    Inhibition of protein kinases has validated therapeutic utility for cancer, with at least seven kinase inhibitor drugs on the market. Protein kinase inhibition also has significant potential for a variety of other diseases, including diabetes, pain, cognition, and chronic inflammatory and immunologic diseases. However, as the vast majority of current approaches to kinase inhibition target the highly conserved ATP-binding site, the use of kinase inhibitors in treating nononcology diseases may require great selectivity for the target kinase. As protein kinases are signal transducers that are involved in binding to a variety of other proteins, targeting alternative, less conserved sites on the protein may provide an avenue for greater selectivity. Here we report an affinity-based, high-throughput screening technique that allows nonbiased interrogation of small molecule libraries for binding to all exposed sites on a protein surface. This approach was used to screen both the c-Jun N-terminal protein kinase Jnk-1 (involved in insulin signaling) and p38{alpha} (involved in the formation of TNF{alpha} and other cytokines). In addition to canonical ATP-site ligands, compounds were identified that bind to novel allosteric sites. The nature, biological relevance, and mode of binding of these ligands were extensively characterized using two-dimensional {sup 1}H/{sup 13}C NMR spectroscopy, protein X-ray crystallography, surface plasmon resonance, and direct enzymatic activity and activation cascade assays. Jnk-1 and p38{alpha} both belong to the MAP kinase family, and the allosteric ligands for both targets bind similarly on a ledge of the protein surface exposed by the MAP insertion present in the CMGC family of protein kinases and distant from the active site. Medicinal chemistry studies resulted in an improved Jnk-1 ligand able to increase adiponectin secretion in human adipocytes and increase insulin-induced protein kinase PKB phosphorylation in human hepatocytes, in

  4. STK33 kinase inhibitor BRD-8899 has no effect on KRAS-dependent cancer cell viability.

    Science.gov (United States)

    Luo, Tuoping; Masson, Kristina; Jaffe, Jacob D; Silkworth, Whitney; Ross, Nathan T; Scherer, Christina A; Scholl, Claudia; Fröhling, Stefan; Carr, Steven A; Stern, Andrew M; Schreiber, Stuart L; Golub, Todd R

    2012-02-21

    Approximately 30% of human cancers harbor oncogenic gain-of-function mutations in KRAS. Despite interest in KRAS as a therapeutic target, direct blockade of KRAS function with small molecules has yet to be demonstrated. Based on experiments that lower mRNA levels of protein kinases, KRAS-dependent cancer cells were proposed to have a unique requirement for the serine/threonine kinase STK33. Thus, it was suggested that small-molecule inhibitors of STK33 might have therapeutic benefit in these cancers. Here, we describe the development of selective, low nanomolar inhibitors of STK33's kinase activity. The most potent and selective of these, BRD8899, failed to kill KRAS-dependent cells. While several explanations for this result exist, our data are most consistent with the view that inhibition of STK33's kinase activity does not represent a promising anti-KRAS therapeutic strategy.

  5. Pharmacological Inhibition of Protein Kinase G1 Enhances Bone Formation by Human Skeletal Stem Cells Through Activation of RhoA-Akt Signaling

    DEFF Research Database (Denmark)

    Kermani, Abbas Jafari; Siersbaek, Majken S; Chen, Li

    2015-01-01

    for several malignant and nonmalignant conditions. We screened a library of kinase inhibitors to identify small molecules that enhance bone formation by human skeletal (stromal or mesenchymal) stem cells (hMSC). We identified H-8 (known to inhibit protein kinases A, C, and G) as a potent enhancer of ex vivo......Development of novel approaches to enhance bone regeneration is needed for efficient treatment of bone defects. Protein kinases play a key role in regulation of intracellular signal transduction pathways, and pharmacological targeting of protein kinases has led to development of novel treatments...

  6. Tyrosine kinase inhibitors and mesenchymal stromal cells: effects on self-renewal, commitment and functions

    Science.gov (United States)

    Borriello, Adriana; Caldarelli, Ilaria; Bencivenga, Debora; Stampone, Emanuela; Perrotta, Silverio; Oliva, Adriana; Ragione, Fulvio Della

    2017-01-01

    The hope of selectively targeting cancer cells by therapy and eradicating definitively malignancies is based on the identification of pathways or metabolisms that clearly distinguish “normal” from “transformed” phenotypes. Some tyrosine kinase activities, specifically unregulated and potently activated in malignant cells, might represent important targets of therapy. Consequently, tyrosine kinase inhibitors (TKIs) might be thought as the “vanguard” of molecularly targeted therapy for human neoplasias. Imatinib and the successive generations of inhibitors of Bcr-Abl1 kinase, represent the major successful examples of TKI use in cancer treatment. Other tyrosine kinases have been selected as targets of therapy, but the efficacy of their inhibition, although evident, is less definite. Two major negative effects exist in this therapeutic strategy and are linked to the specificity of the drugs and to the role of the targeted kinase in non-malignant cells. In this review, we will discuss the data available on the TKIs effects on the metabolism and functions of mesenchymal stromal cells (MSCs). MSCs are widely distributed in human tissues and play key physiological roles; nevertheless, they might be responsible for important pathologies. At present, bone marrow (BM) MSCs have been studied in greater detail, for both embryological origins and functions. The available data are evocative of an unexpected degree of complexity and heterogeneity of BM-MSCs. It is conceivable that this grade of intricacy occurs also in MSCs of other organs. Therefore, in perspective, the negative effects of TKIs on MSCs might represent a critical problem in long-term cancer therapies based on such inhibitors. PMID:27750212

  7. Structure-Based Design of a Novel Series of Potent, Selective Inhibitors of the Class I Phosphatidylinositol 3-Kinases

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Adrian L.; D’Angelo, Noel D.; Bo, Yunxin Y.; Booker, Shon K.; Cee, Victor J.; Herberich, Brad; Hong, Fang-Tsao; Jackson, Claire L.M.; Lanman, Brian A.; Liu, Longbin; Nishimura, Nobuko; Pettus, Liping H.; Reed, Anthony B.; Tadesse, Seifu; Tamayo, Nuria A.; Wurz, Ryan P.; Yang, Kevin; Andrews, Kristin L.; Whittington, Douglas A.; McCarter, John D.; Miguel, Tisha San; Zalameda, Leeanne; Jiang, Jian; Subramanian, Raju; Mullady, Erin L.; Caenepeel, Sean; Freeman, Daniel J.; Wang, Ling; Zhang, Nancy; Wu, Tian; Hughes, Paul E.; Norman, Mark H. (Amgen)

    2012-09-17

    A highly selective series of inhibitors of the class I phosphatidylinositol 3-kinases (PI3Ks) has been designed and synthesized. Starting from the dual PI3K/mTOR inhibitor 5, a structure-based approach was used to improve potency and selectivity, resulting in the identification of 54 as a potent inhibitor of the class I PI3Ks with excellent selectivity over mTOR, related phosphatidylinositol kinases, and a broad panel of protein kinases. Compound 54 demonstrated a robust PD-PK relationship inhibiting the PI3K/Akt pathway in vivo in a mouse model, and it potently inhibited tumor growth in a U-87 MG xenograft model with an activated PI3K/Akt pathway.

  8. RhoA is dispensable for skin development, but crucial for contraction and directed migration of keratinocytes

    DEFF Research Database (Denmark)

    Jackson, Ben; Peyrollier, Karine; Pedersen, Esben

    2011-01-01

    RhoA is a small guanosine-5'-triphosphatase (GTPase) suggested to be essential for cytokinesis, stress fiber formation, and epithelial cell-cell contacts. In skin, loss of RhoA was suggested to underlie pemphigus skin blistering. To analyze RhoA function in vivo, we generated mice with a keratino......RhoA is a small guanosine-5'-triphosphatase (GTPase) suggested to be essential for cytokinesis, stress fiber formation, and epithelial cell-cell contacts. In skin, loss of RhoA was suggested to underlie pemphigus skin blistering. To analyze RhoA function in vivo, we generated mice......-cell contacts. Furthermore we observed increased cell spreading due to impaired RhoA-ROCK (Rho-associated protein kinase)-MLC phosphatase-MLC-mediated cell contraction, independent of Rac1. Rho-inhibiting toxins further increased multinucleation of RhoA-null cells but had no significant effect on spreading......, suggesting that RhoB and RhoC have partially overlapping functions with RhoA. Loss of RhoA decreased directed cell migration in vitro caused by reduced migration speed and directional persistence. These defects were not related to the decreased cell contraction and were independent of ROCK, as ROCK...

  9. Rho GTPases, their post-translational modifications, disease-associated mutations and pharmacological inhibitors.

    Science.gov (United States)

    Olson, Michael F

    2018-05-04

    The 20 members of the Rho GTPase family are key regulators of a wide-variety of biological activities. In response to activation, they signal via downstream effector proteins to induce dynamic alterations in the organization of the actomyosin cytoskeleton. In this review, post-translational modifications, mechanisms of dysregulation identified in human pathological conditions, and the ways that Rho GTPases might be targeted for chemotherapy will be discussed.

  10. Knockout of the PKN Family of Rho Effector Kinases Reveals a Non-redundant Role for PKN2 in Developmental Mesoderm Expansion

    Directory of Open Access Journals (Sweden)

    Ivan Quétier

    2016-01-01

    Full Text Available In animals, the protein kinase C (PKC family has expanded into diversely regulated subgroups, including the Rho family-responsive PKN kinases. Here, we describe knockouts of all three mouse PKN isoforms and reveal that PKN2 loss results in lethality at embryonic day 10 (E10, with associated cardiovascular and morphogenetic defects. The cardiovascular phenotype was not recapitulated by conditional deletion of PKN2 in endothelial cells or the developing heart. In contrast, inducible systemic deletion of PKN2 after E7 provoked collapse of the embryonic mesoderm. Furthermore, mouse embryonic fibroblasts, which arise from the embryonic mesoderm, depend on PKN2 for proliferation and motility. These cellular defects are reflected in vivo as dependence on PKN2 for mesoderm proliferation and neural crest migration. We conclude that failure of the mesoderm to expand in the absence of PKN2 compromises cardiovascular integrity and development, resulting in lethality.

  11. The inhibitors of cyclin-dependent kinases and GSK-3β enhance osteoclastogenesis

    Directory of Open Access Journals (Sweden)

    Yosuke Akiba

    2016-03-01

    Full Text Available Osteoclasts are multinucleated cells with bone resorption activity that is crucial for bone remodeling. RANK‐RANKL (receptor activator of nuclear factor κB ligand signaling has been shown as a main signal pathway for osteoclast differentiation. However, the molecular mechanism and the factors regulating osteoclastogenesis remain to be fully understood. In this study, we performed a chemical genetic screen, and identified a Cdks/GSK-3β (cyclin-dependent kinases/glycogen synthase kinaseinhibitor, kenpaullone, and two Cdks inhibitors, olomoucine and roscovitine, all of which significantly enhance osteoclastogenesis of RAW264.7 cells by upregulating NFATc1 (nuclear factor of activated T cells, cytoplasmic 1 levels. We also determined that the all three compounds increase the number of osteoclast differentiated from murine bone marrow cells. Furthermore, the three inhibitors, especially kenpaullone, promoted maturation of cathepsin K, suggesting that the resorption activity of the resultant osteoclasts is also activated. Our findings indicate that inhibition of GSK-3β and/or Cdks enhance osteoclastogenesis by modulating the RANK–RANKL signaling pathway.

  12. A historical overview of protein kinases and their targeted small molecule inhibitors.

    Science.gov (United States)

    Roskoski, Robert

    2015-10-01

    catalytic subunits. PKA and all other protein kinase domains have a small amino-terminal lobe and large carboxyterminal lobe as determined by X-ray crystallography. The N-lobe and C-lobe form a cleft that serves as a docking site for MgATP. Nearly all active protein kinases contain a K/E/D/D signature sequence that plays important structural and catalytic roles. Protein kinases contain hydrophobic catalytic and regulatory spines and collateral shell residues that are required to assemble the active enzyme. There are two general kinds of conformational changes associated with most protein kinases. The first conformational change involves the formation of an intact regulatory spine to form an active enzyme. The second conformational change occurs in active kinases as they toggle between open and closed conformations during their catalytic cycles. Because mutations and dysregulation of protein kinases play causal roles in human disease, this family of enzymes has become one of the most important drug targets over the past two decades. Imatinib was approved by the United States FDA for the treatment of chronic myelogenous leukemia in 2001; this small molecule inhibits the BCR-Abl protein kinase oncoprotein that results from the formation of the Philadelphia chromosome. More than two dozen other orally effective mechanism-based small molecule protein kinase inhibitors have been subsequently approved by the FDA. These drugs bind to the ATP-binding site of their target enzymes and extend into nearby hydrophobic pockets. Most of these protein kinase inhibitors prolong survival in cancer patients only weeks or months longer than standard cytotoxic therapies. In contrast, the clinical effectiveness of imatinib against chronic myelogenous leukemia is vastly superior to that of any other targeted protein kinase inhibitor with overall survival lasting a decade or more. However, the near universal and expected development of drug resistance in the treatment of neoplastic disorders

  13. Regulation of mitotic spindle formation by the RhoA guanine nucleotide exchange factor ARHGEF10

    Directory of Open Access Journals (Sweden)

    Satoh Takaya

    2009-07-01

    Full Text Available Abstract Background The Dbl family guanine nucleotide exchange factor ARHGEF10 was originally identified as the product of the gene associated with slowed nerve-conduction velocities of peripheral nerves. However, the function of ARHGEF10 in mammalian cells is totally unknown at a molecular level. ARHGEF10 contains no distinctive functional domains except for tandem Dbl homology-pleckstrin homology and putative transmembrane domains. Results Here we show that RhoA is a substrate for ARHGEF10. In both G1/S and M phases, ARHGEF10 was localized in the centrosome in adenocarcinoma HeLa cells. Furthermore, RNA interference-based knockdown of ARHGEF10 resulted in multipolar spindle formation in M phase. Each spindle pole seems to contain a centrosome consisting of two centrioles and the pericentriolar material. Downregulation of RhoA elicited similar phenotypes, and aberrant mitotic spindle formation following ARHGEF10 knockdown was rescued by ectopic expression of constitutively activated RhoA. Multinucleated cells were not increased upon ARHGEF10 knockdown in contrast to treatment with Y-27632, a specific pharmacological inhibitor for the RhoA effector kinase ROCK, which induced not only multipolar spindle formation, but also multinucleation. Therefore, unregulated centrosome duplication rather than aberration in cytokinesis may be responsible for ARHGEF10 knockdown-dependent multipolar spindle formation. We further isolated the kinesin-like motor protein KIF3B as a binding partner of ARHGEF10. Knockdown of KIF3B again caused multipolar spindle phenotypes. The supernumerary centrosome phenotype was also observed in S phase-arrested osteosarcoma U2OS cells when the expression of ARHGEF10, RhoA or KIF3B was abrogated by RNA interference. Conclusion Collectively, our results suggest that a novel RhoA-dependent signaling pathway under the control of ARHGEF10 has a pivotal role in the regulation of the cell division cycle. This pathway is not involved in

  14. Expression loss and revivification of RhoB gene in ovary carcinoma carcinogenesis and development.

    Science.gov (United States)

    Liu, Yingwei; Song, Na; Ren, Kexing; Meng, Shenglan; Xie, Yao; Long, Qida; Chen, Xiancheng; Zhao, Xia

    2013-01-01

    RhoB, a member of small GTPases belonging to the Ras protein superfamily, might have a suppressive activity in cancer progression. Here, expression of RhoB gene was evaluated in human benign, borderline and malignant ovary tumors by immunostaining, with normal ovary tissue as control. Malignant tumors were assessed according to Federation Internationale de Gynecologie Obstetrique (FIGO) guidelines and classified in stage I-IV. Revivification of RhoB gene was investigated by analyzing the effect of histone deacetylase (HDAC) inhibitor trichostatin (TSA) and methyltransferase inhibitor 5-azacytidine (5-Aza) on ovarian cancer cells via RT-PCR and western blot. Apoptosis of ovary cancer cells was detected using flowcytometry and fluorescence microscopy. Subsequently, RhoB expression is detected in normal ovary epithelium, borderline tumors, and decreases significantly or lost in the majority of ovarian cancer specimen (Pcancer cells, but 5-Aza couldn't. Interference into Revivification of RhoB gene results in reduction of ovary carcinoma cell apoptosis. It is proposed that loss of RhoB expression occurs frequently in ovary carcinogenesis and progression and its expression could be regulated by histone deacetylation but not by promoter hypermethylation, which may serve as a prospective gene treatment target for the patients with ovarian malignancy not responding to standard therapies.

  15. An Aminopyridazine Inhibitor of Death Associated Protein Kinase Attenuates Hypoxia-Ischemia Induced Brain Damage

    Energy Technology Data Exchange (ETDEWEB)

    Velentza, A.V.; Wainwright, M.S.; Zasadzki, M.; Mirzoeva, S.; Haiech, J.; Focia, P.J.; Egli, M.; Watterson, D.M.

    2010-03-08

    Death associated protein kinase (DAPK) is a calcium and calmodulin regulated enzyme that functions early in eukaryotic programmed cell death, or apoptosis. To validate DAPK as a potential drug discovery target for acute brain injury, the first small molecule DAPK inhibitor was synthesized and tested in vivo. A single injection of the aminopyridazine-based inhibitor administered 6 h after injury attenuated brain tissue or neuronal biomarker loss measured, respectively, 1 week and 3 days later. Because aminopyridazine is a privileged structure in neuropharmacology, we determined the high-resolution crystal structure of a binary complex between the kinase domain and a molecular fragment of the DAPK inhibitor. The co-crystal structure describes a structural basis for interaction and provides a firm foundation for structure-assisted design of lead compounds with appropriate molecular properties for future drug development.

  16. transplanted organs

    Directory of Open Access Journals (Sweden)

    Rafal Szadujkis-Szadurski

    2014-08-01

    Full Text Available Rho-kinase and GTP-ase Rho are important regulators of vascular tone and blood pressure. The aim of this study was to investigate the role of Rho-kinase in artery reactions induced by angiotensin II (ANG II and the effects of ischemia-reperfusion injury as well as the function of intra- and extracellular calcium in these reactions. Experiments were performed on mesenteric superior arteries procured from cadaveric organ donors and conserved under the same conditions as transplanted kidneys. The vascular contraction in reaction to ANG II was measured in the presence of Rho-kinase inhibitor Y-27632, after ischemia and reperfusion, in Ca2+ and Ca2+-free solution. The maximal response to ANG II was reduced after ischemia, while an increase was observed after reperfusion. Vascular contraction induced by ANG II was decreased by Y-27632. Y-27632 reduced vascular contraction after reperfusion, both in Ca2+ and Ca2+-free solution. Reperfusion augments vascular contraction in reaction to ANG II. The Rho-kinase inhibitor Y-27632 reduces the hypersensitivity to ANG II after reperfusion mediated by both intra- and extracellular calcium. These results confirm the role of Rho-kinase in receptor-independent function of ANG II and in reperfusion-induced hypersensitivity.

  17. Photoactivatable Caged Prodrugs of VEGFR-2 Kinase Inhibitors

    Directory of Open Access Journals (Sweden)

    Boris Pinchuk

    2016-04-01

    Full Text Available In this study, we report on the design, synthesis, photokinetic properties and in vitro evaluation of photoactivatable caged prodrugs for the receptor tyrosine kinase VEGFR-2. Highly potent VEGFR-2 inhibitors 1 and 3 were caged by introduction of a photoremovable protecting group (PPG to yield the caged prodrugs 4 and 5. As expected, enzymatic and cellular proliferation assays showed dramatically diminished efficacy of caged prodrugs in vitro. Upon ultraviolet (UV irradiation of the prodrugs original inhibitory activity was completely restored and even distinctly reinforced, as was the case for the prodrug 4. The presented results are a further evidence for caging technique being an interesting approach in the protein kinase field. It could enable spatial and temporal control for the inhibition of VEGFR-2. The described photoactivatable prodrugs might be highly useful as biological probes for studying the VEGFR-2 signal transduction.

  18. Combined effects of EGFR tyrosine kinase inhibitors and vATPase inhibitors in NSCLC cells

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Hyeon-Ok [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Hong, Sung-Eun [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Kim, Chang Soon [Department of Microbiological Engineering, Kon-Kuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 143–701 (Korea, Republic of); Park, Jin-Ah; Kim, Jin-Hee; Kim, Ji-Young; Kim, Bora [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Chang, Yoon Hwan; Hong, Seok-Il; Hong, Young Jun [Department of Laboratory Medicine, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Park, In-Chul, E-mail: parkic@kirams.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Lee, Jin Kyung, E-mail: jklee@kirams.re.kr [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Department of Laboratory Medicine, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of)

    2015-08-15

    Despite excellent initial clinical responses of non-small cell lung cancer (NSCLC) patients to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), many patients eventually develop resistance. According to a recent report, vacuolar H + ATPase (vATPase) is overexpressed and is associated with chemotherapy drug resistance in NSCLC. We investigated the combined effects of EGFR TKIs and vATPase inhibitors and their underlying mechanisms in the regulation of NSCLC cell death. We found that combined treatment with EGFR TKIs (erlotinib, gefitinib, or lapatinib) and vATPase inhibitors (bafilomycin A1 or concanamycin A) enhanced synergistic cell death compared to treatments with each drug alone. Treatment with bafilomycin A1 or concanamycin A led to the induction of Bnip3 expression in an Hif-1α dependent manner. Knock-down of Hif-1α or Bnip3 by siRNA further enhanced cell death induced by bafilomycin A1, suggesting that Hif-1α/Bnip3 induction promoted resistance to cell death induced by the vATPase inhibitors. EGFR TKIs suppressed Hif-1α and Bnip3 expression induced by the vATPase inhibitors, suggesting that they enhanced the sensitivity of the cells to these inhibitors by decreasing Hif-1α/Bnip3 expression. Taken together, we conclude that EGFR TKIs enhance the sensitivity of NSCLC cells to vATPase inhibitors by decreasing Hif-1α/Bnip3 expression. We suggest that combined treatment with EGFR TKIs and vATPase inhibitors is potentially effective for the treatment of NSCLC. - Highlights: • Co-treatment with EGFR TKIs and vATPase inhibitors induces synergistic cell death • EGFR TKIs enhance cell sensitivity to vATPase inhibitors via Hif-1α downregulation • Co-treatment of these inhibitors is potentially effective for the treatment of NSCLC.

  19. TYROSINE KINASE INHIBITORS AND PREGNANCY

    Directory of Open Access Journals (Sweden)

    Elisabetta Abruzzese

    2014-04-01

    Full Text Available The management of patients with chronic myeloid leukemia (CML during pregnancy has became recently a matter of continuous debate.  The introduction of the Tyrosine Kinase Inhibitors (TKIs in clinical practice has dramatically changed the prognosis of CML patients.  Patients diagnosed in chronic phase can reasonably expect many years of excellent disease control and good quality of life, as well as a normal life expectancy.  This fact has come the necessity to address issues relating to fertility and pregnancy. Physicians are not infrequently being asked for advice regarding the need for, and or the appropriateness of, stopping treatment in order to conceive. In this report we will review the data published in terms of fertility, conception, pregnancy, pregnancy outcome and illness control for all the approved TKIs, as well as suggest how to manage a planned and/or unplanned pregnancy.

  20. An integrative study to identify novel scaffolds for sphingosine kinase 1 inhibitors

    Czech Academy of Sciences Publication Activity Database

    Vettorazzi, M.; Angelina, E.; Lima, S.; Goněc, T.; Otevřel, J.; Marvanová, P.; Padrtová, T.; Mokrý, P.; Bobáľ, P.; Acosta, L. M.; Palma, A.; Cobo, J.; Bobálová, Janette; Csollei, J.; Malik, I.; Alvarez, S.; Spiegel, S.; Jampílek, J.; Enriz, R. D.

    2017-01-01

    Roč. 139, OCT (2017), s. 461-481 ISSN 0223-5234 Institutional support: RVO:68081715 Keywords : sphingosine kinase 1 inhibitors * bioassays * molecular modelling * virtual screening Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.519, year: 2016

  1. Nature of extracellular signal that triggers RhoA/ROCK activation for the basal internal anal sphincter tone in humans

    Science.gov (United States)

    Singh, Jagmohan; Kumar, Sumit; Phillips, Benjamin

    2015-01-01

    The extracellular signal that triggers activation of rho-associated kinase (RhoA/ROCK), the major molecular determinant of basal internal anal sphincter (IAS) smooth muscle tone, is not known. Using human IAS tissues, we identified the presence of the biosynthetic machineries for angiotensin II (ANG II), thromboxane A2 (TXA2), and prostaglandin F2α (PGF2α). These end products of the renin-angiotensin system (RAS) (ANG II) and arachidonic acid (TXA2 and PGF2α) pathways and their effects in human IAS vs. rectal smooth muscle (RSM) were studied. A multipronged approach utilizing immunocytochemistry, Western blot analyses, and force measurements was implemented. Additionally, in a systematic analysis of the effects of respective inhibitors along different steps of biosynthesis and those of antagonists, their end products were evaluated either individually or in combination. To further describe the molecular mechanism for the IAS tone via these pathways, we monitored RhoA/ROCK activation and its signal transduction cascade. Data showed characteristically higher expression of biosynthetic machineries of RAS and AA pathways in the IAS compared with the RSM. Additionally, specific inhibition of the arachidonic acid (AA) pathway caused ∼80% decrease in the IAS tone, whereas that of RAS lead to ∼20% decrease. Signal transduction studies revealed that the end products of both AA and RAS pathways cause increase in the IAS tone via activation of RhoA/ROCK. Both AA and RAS (via the release of their end products TXA2, PGF2α, and ANG II, respectively), provide extracellular signals which activate RhoA/ROCK for the maintenance of the basal tone in human IAS. PMID:25882611

  2. Viral activation of MK2-hsp27-p115RhoGEF-RhoA signaling axis causes cytoskeletal rearrangements, p-body disruption and ARE-mRNA stabilization.

    Directory of Open Access Journals (Sweden)

    Jennifer A Corcoran

    2015-01-01

    Full Text Available Kaposi's sarcoma-associated herpesvirus (KSHV is the infectious cause of several AIDS-related cancers, including the endothelial cell (EC neoplasm Kaposi's sarcoma (KS. KSHV-infected ECs secrete abundant host-derived pro-inflammatory molecules and angiogenic factors that contribute to tumorigenesis. The precise contributions of viral gene products to this secretory phenotype remain to be elucidated, but there is emerging evidence for post-transcriptional regulation. The Kaposin B (KapB protein is thought to contribute to the secretory phenotype in infected cells by binding and activating the stress-responsive kinase MK2, thereby selectively blocking decay of AU-rich mRNAs (ARE-mRNAs encoding pro-inflammatory cytokines and angiogenic factors. Processing bodies (PBs are cytoplasmic ribonucleoprotein foci in which ARE-mRNAs normally undergo rapid 5' to 3' decay. Here, we demonstrate that PB dispersion is a feature of latent KSHV infection, which is dependent on kaposin protein expression. KapB is sufficient to disperse PBs, and KapB-mediated ARE-mRNA stabilization could be partially reversed by treatments that restore PBs. Using a combination of genetic and chemical approaches we provide evidence that KapB-mediated PB dispersion is dependent on activation of a non-canonical Rho-GTPase signaling axis involving MK2, hsp27, p115RhoGEF and RhoA. PB dispersion in latently infected cells is likewise dependent on p115RhoGEF. In addition to PB dispersion, KapB-mediated RhoA activation in primary ECs caused actin stress fiber formation, increased cell motility and angiogenesis; these effects were dependent on the activity of the RhoA substrate kinases ROCK1/2. By contrast, KapB-mediated PB dispersion occurred in a ROCK1/2-independent manner. Taken together, these observations position KapB as a key contributor to viral reprogramming of ECs, capable of eliciting many of the phenotypes characteristic of KS tumor cells, and strongly contributing to the post

  3. Modulation of neutrophil superoxide generation by inhibitors of protein kinase C, calmodulin, diacylglycerol and myosin light chain kinases, and peptidyl prolyl cis-trans isomerase.

    Science.gov (United States)

    Bergstrand, H; Eriksson, T; Hallberg, A; Johansson, B; Karabelas, K; Michelsen, P; Nybom, A

    1992-12-01

    To assess the role of protein kinase C (PKC) in the respiratory burst of adherent human polymorphonuclear leukocytes (PMNL), reduction of ferricytochrome C by cells triggered with a phorbol ester (PMA), ionophore A23187, serum-treated zymosan (STZ) or three lipid derivatives, 3-decanoyl-sn-glycerol (G-3-OCOC9), (R,R)-1,4-diethyl-2-O-decyl-L-tartrate (Tt-2-OC10) and 3-decyloxy-5-hydroxymethylphenol (DHP) was examined in a microtiter plate procedure in the presence of inhibitors of PKC and, for comparison, inhibitors of calmodulin, diacylglycerol and myosin light chain kinases and the peptidyl-prolyl cis-trans isomerase activity of fujiphilin. 1) Of the protein kinase inhibitors examined, Ro 31-7549 and staurosporine reduced responses to all stimuli except possibly STZ; in contrast, K252a and the myosin light chain kinase inhibitors ML-7 and ML-9 blocked responses to A23187 and STZ better than those triggered by PMA. H-7 reduced responses to A23187, DHP and G-3-OCOC9, and calphostin, palmitoyl carnitine, sphingosine and the multifunctional drugs TMB-8 and W-7 reduced A23187; they also, when examined, reduced decane derivative-induced O2- production more effectively than PMA- and STZ-triggered responses. Polymyxin B, 4 alpha-PMA and retinal displayed no inhibitory capacity. 2) Of the selective calmodulin antagonists, CGS 9343B, Ro 22-4839 and calmidazolium did not inhibit the oxidative response irrespective of the stimulus used, whereas metofenazate reduced those evoked by A23187, DHP, G-3-OCOC9 and STZ.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. A comprehensive target selectivity survey of the BCR-ABL kinase inhibitor INNO-406 by kinase profiling and chemical proteomics in chronic myeloid leukemia cells.

    Science.gov (United States)

    Rix, U; Remsing Rix, L L; Terker, A S; Fernbach, N V; Hantschel, O; Planyavsky, M; Breitwieser, F P; Herrmann, H; Colinge, J; Bennett, K L; Augustin, M; Till, J H; Heinrich, M C; Valent, P; Superti-Furga, G

    2010-01-01

    Resistance to the BCR-ABL tyrosine kinase inhibitor imatinib poses a pressing challenge in treating chronic myeloid leukemia (CML). This resistance is often caused by point mutations in the ABL kinase domain or by overexpression of LYN. The second-generation BCR-ABL inhibitor INNO-406 is known to inhibit most BCR-ABL mutants and LYN efficiently. Knowledge of its full target spectrum would provide the molecular basis for potential side effects or suggest novel therapeutic applications and possible combination therapies. We have performed an unbiased chemical proteomics native target profile of INNO-406 in CML cells combined with functional assays using 272 recombinant kinases thereby identifying several new INNO-406 targets. These include the kinases ZAK, DDR1/2 and various ephrin receptors. The oxidoreductase NQO2, inhibited by both imatinib and nilotinib, is not a relevant target of INNO-406. Overall, INNO-406 has an improved activity over imatinib but a slightly broader target profile than both imatinib and nilotinib. In contrast to dasatinib and bosutinib, INNO-406 does not inhibit all SRC kinases and most TEC family kinases and is therefore expected to elicit fewer side effects. Altogether, these properties may make INNO-406 a valuable component in the drug arsenal against CML.

  5. Ameloblasts require active RhoA to generate normal dental enamel.

    Science.gov (United States)

    Xue, Hui; Li, Yong; Everett, Eric T; Ryan, Kathleen; Peng, Li; Porecha, Rakhee; Yan, Yan; Lucchese, Anna M; Kuehl, Melissa A; Pugach, Megan K; Bouchard, Jessica; Gibson, Carolyn W

    2013-08-01

    RhoA plays a fundamental role in regulation of the actin cytoskeleton, intercellular attachment, and cell proliferation. During amelogenesis, ameloblasts (which produce the enamel proteins) undergo dramatic cytoskeletal changes and the RhoA protein level is up-regulated. Transgenic mice were generated that express a dominant-negative RhoA transgene in ameloblasts using amelogenin gene-regulatory sequences. Transgenic and wild-type (WT) molar tooth germs were incubated with sodium fluoride (NaF) or sodium chloride (NaCl) in organ culture. Filamentous actin (F-actin) stained with phalloidin was elevated significantly in WT ameloblasts treated with NaF compared with WT ameloblasts treated with NaCl or with transgenic ameloblasts treated with NaF, thereby confirming a block in the RhoA/Rho-associated protein kinase (ROCK) pathway in the transgenic mice. Little difference in quantitative fluorescence (an estimation of fluorosis) was observed between WT and transgenic incisors from mice provided with drinking water containing NaF. We subsequently found reduced transgene expression in incisors compared with molars. Transgenic molar teeth had reduced amelogenin, E-cadherin, and Ki67 compared with WT molar teeth. Hypoplastic enamel in transgenic mice correlates with reduced expression of the enamel protein, amelogenin, and E-cadherin and cell proliferation are regulated by RhoA in other tissues. Together these findings reveal deficits in molar ameloblast function when RhoA activity is inhibited. © 2013 Eur J Oral Sci.

  6. Structure-Based Design of Potent and Selective 3-Phosphoinositide-Dependent Kinase-1 (PDK1) Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Medina, Jesus R.; Becker, Christopher J.; Blackledge, Charles W.; Duquenne, Celine; Feng, Yanhong; Grant, Seth W.; Heerding, Dirk; Li, William H.; Miller, William H.; Romeril, Stuart P.; Scherzer, Daryl; Shu, Arthur; Bobko, Mark A.; Chadderton, Antony R.; Dumble, Melissa; Gardiner, Christine M.; Gilbert, Seth; Liu, Qi; Rabindran, Sridhar K.; Sudakin, Valery; Xiang, Hong; Brady, Pat G.; Campobasso, Nino; Ward, Paris; Axten, Jeffrey M. (GSKPA)

    2014-10-02

    Phosphoinositide-dependent protein kinase-1(PDK1) is a master regulator of the AGC family of kinases and an integral component of the PI3K/AKT/mTOR pathway. As this pathway is among the most commonly deregulated across all cancers, a selective inhibitor of PDK1 might have utility as an anticancer agent. Herein we describe our lead optimization of compound 1 toward highly potent and selective PDK1 inhibitors via a structure-based design strategy. The most potent and selective inhibitors demonstrated submicromolar activity as measured by inhibition of phosphorylation of PDK1 substrates as well as antiproliferative activity against a subset of AML cell lines. In addition, reduction of phosphorylation of PDK1 substrates was demonstrated in vivo in mice bearing OCl-AML2 xenografts. These observations demonstrate the utility of these molecules as tools to further delineate the biology of PDK1 and the potential pharmacological uses of a PDK1 inhibitor.

  7. Pharmacogenetics of telatinib, a VEGFR-2 and VEGFR-3 tyrosine kinase inhibitor, used in patients with solid tumors

    NARCIS (Netherlands)

    N. Steeghs (Neeltje); A.J. Gelderblom (Hans); J.A.M. Wessels (Judith); F.A.L.M. Eskens (Ferry); N. de Bont (Natasja); J.W. Nortier (Johan); H.J. Guchelaar (Henk Jan)

    2011-01-01

    textabstractSummary: Purpose Telatinib is an orally active small-molecule tyrosine kinase inhibitor of kinase insert domain receptor (KDR; VEGFR-2) and fms-related tyrosine kinase 4 (FLT4; VEGFR-3). This study aims at the identification of relationships between single nucleotide polymorphisms (SNPs)

  8. Differential expression of mRNAs for protein kinase inhibitor isoforms in mouse brain.

    OpenAIRE

    Seasholtz, A F; Gamm, D M; Ballestero, R P; Scarpetta, M A; Uhler, M D

    1995-01-01

    Many neurotransmitters are known to regulate neuronal cell function by means of activation of cAMP-dependent protein kinase (PKA) and phosphorylation of neuronal substrate proteins, including transcription factors and ion channels. Here, we have characterized the gene expression of two isoforms of a protein kinase inhibitor (PKI) specific for PKA in mouse brain by RNase protection and in situ hybridization histochemistry. The studies demonstrate that the PKI alpha isoform is abundant in many ...

  9. The 'invisible hand': regulation of RHO GTPases by RHOGDIs.

    Science.gov (United States)

    Garcia-Mata, Rafael; Boulter, Etienne; Burridge, Keith

    2011-07-22

    The 'invisible hand' is a term originally coined by Adam Smith in The Theory of Moral Sentiments to describe the forces of self-interest, competition and supply and demand that regulate the resources in society. This metaphor continues to be used by economists to describe the self-regulating nature of a market economy. The same metaphor can be used to describe the RHO-specific guanine nucleotide dissociation inhibitor (RHOGDI) family, which operates in the background, as an invisible hand, using similar forces to regulate the RHO GTPase cycle.

  10. The invisible hand: regulation of RHO GTPases by RHOGDIs

    Science.gov (United States)

    Garcia-Mata, Rafael; Boulter, Etienne; Burridge, Keith

    2011-01-01

    Preface The 'invisible hand' is a term originally coined by Adam Smith in the Theory of Moral Sentiments to describe the forces of self-interest, competition, and supply and demand that regulate the resources in society. This metaphor continues to be used by economists to describe the self-regulating nature of a market economy. The same metaphor can be used to describe the RHO-specific guanine nucleotide dissociation inhibitor (RHOGDI) family, which operates in the background, as an invisible hand, using similar forces to regulate the RHO GTPase cycle. PMID:21779026

  11. Mouse macrophages completely lacking Rho (RhoA, RhoB and RhoC) have severe lamellipodial retraction defects, but robust chemotactic navigation and increased motility

    DEFF Research Database (Denmark)

    Koenigs, Volker; Jennings, Richard; Vogl, Thomas

    2014-01-01

    RhoA is thought to be essential for coordination of the membrane protrusions and retractions required for immune cell motility and directed migration. Whether the subfamily of Rho (Ras homolog) GTPases (RhoA, RhoB and RhoC) is actually required for the directed migration of primary cells is diffi...

  12. Insulin stimulates phospholipase D-dependent phosphatidylcholine hydrolysis, Rho translocation, de novo phospholipid synthesis, and diacylglycerol/protein kinase C signaling in L6 myotubes.

    Science.gov (United States)

    Standaert, M L; Bandyopadhyay, G; Zhou, X; Galloway, L; Farese, R V

    1996-07-01

    Previous studies have provided conflicting findings on whether insulin activates certain, potentially important, phospholipid signaling systems in skeletal muscle preparations. In particular, insulin effects on the hydrolysis of phosphatidylcholine (PC) and subsequent activation of protein kinase C (PKC) have not been apparent in some studies. Presently, we examined insulin effects on phospholipid signaling systems, diacylglycerol (DAG) production, and PKC translocation/activation in L6 myotubes. We found that insulin provoked rapid increases in phospholipase D (PLD)-dependent hydrolysis of PC, as evidenced by increases in choline release and phosphatidylethanol production in cells incubated in the presence of ethanol. In association with PC-PLD activation, Rho, a small G protein that is known to activate PC-PLD activation, translocated from the cytosol to the membrane fraction in response to insulin treatment. PC-PLD activation was also accompanied by increases in total DAG production and increases in the translocation of both PKC enzyme activity and DAG-sensitive PKC-alpha, -beta, -delta, and -epsilon from the cytosol to the membrane fraction. A potential role for PKC or a related protein kinase in insulin action was suggested by the finding that RO 31-8220 inhibited both PKC enzyme activity and insulin-stimulated [3H]2-deoxyglucose uptake. Our findings provide the first evidence that insulin stimulates Rho translocation and activates PC-PLD in L6 skeletal muscle cells. Moreover, this signaling system appears to lead to increases in DAG/PKC signaling, which, along with other related signaling factors, may regulate certain metabolic processes, such as glucose transport, in these cells.

  13. Preferential Selectivity of Inhibitors with Human Tau Protein Kinase Gsk3 Elucidates Their Potential Roles for Off-Target Alzheimer’s Therapy

    Directory of Open Access Journals (Sweden)

    Jagadeesh Kumar Dasappa

    2013-01-01

    Full Text Available Alzheimer’s disease (AD is a neurodegenerative disorder characterized by the accumulation of amyloid beta peptides (A and neurofibrillary tangles (NFTs. The abnormal phosphorylation of tau leads to the formation of NFTs produced by the action of tau kinases, resulting in the loss of neurons and synapse, leading to dementia. Hence, tau kinases have become potential drug target candidates for small molecule inhibitors. With an aim to explore the identification of a common inhibitor, this investigation was undertaken towards analyzing all 10 tau kinases which are implicated in phosphorylation of AD. A set of 7 inhibitors with varied scaffolds were collected from the Protein Data Bank (PDB. The analysis, involving multiple sequence alignment, 3D structural alignment, catalytic active site overlap, and docking studies, has enabled elucidation of the pharmacophoric patterns for the class of 7 inhibitors. Our results divulge that tau protein kinases share a specific set of conserved structural elements for the binding of inhibitors and ATP, respectively. The scaffold of 3-aminopyrrolidine (inhibitor 6 exhibits high preferential affinity with GSK3. Surprisingly, the PDB does not contain the structural details of GSK3 with this specific inhibitor. Thus, our investigations provide vital clues towards design of novel off-target drugs for Alzheimer’s.

  14. The effect of MRN complex and ATM kinase inhibitors on Zebrafish embryonic development

    Science.gov (United States)

    Kumaran, Malina; Fazry, Shazrul

    2018-04-01

    Zebrafish is an ideal animal model to study developmental biology due to its transparent embryos and rapid development stages of embryogenesis. Here we investigate the role of DNA damage proteins, specifically Mre11/Rad50/NBN (MRN) complex and ataxia-telangiectasia mutated (ATM) kinase during embryogenesis by inhibiting its function using specific MRN complex (Mirin) and ATM Kinase inhibitors (Ku60019 and Ku55933). Zebrafish embryos at midblastula transition (MBT) stage are treated with Mirin, Ku60019 and Ku55933. The embryonic development of the embryos was monitored at 24 hours-post fertilisation (hpf), 48 hpf and 72 hpf. We observed that at the lowest concentrations (3 µM of Mirin, 1.5 nM of Ku60019 and 3 nM of Ku55933), the inhibitors treated embryos have 100% survivability. However, with increasing inhibitor concentration, the survivability drops. Control or mock treatment of all embryos shows 100 % survivability rate. This study suggests that DNA damage repair proteins may be crucial for normal zebrafish embryo development and survival.

  15. Identification of novel inhibitors for Pim-1 kinase using pharmacophore modeling based on a novel method for selecting pharmacophore generation subsets

    Science.gov (United States)

    Shahin, Rand; Swellmeen, Lubna; Shaheen, Omar; Aboalhaija, Nour; Habash, Maha

    2016-01-01

    Targeting Proviral integration-site of murine Moloney leukemia virus 1 kinase, hereafter called Pim-1 kinase, is a promising strategy for treating different kinds of human cancer. Headed for this a total list of 328 formerly reported Pim-1 kinase inhibitors has been explored and divided based on the pharmacophoric features of the most active molecules into 10 subsets projected to represent potential active binding manners accessible to ligands within the binding pocket of Pim-1 kinase. Discovery Studio 4.1 (DS 4.1) was employed to detect potential pharmacophoric active binding manners anticipated by Pim-1 Kinase inhibitors. The pharmacophoric models were then allowed to compete within Quantitative Structure Activity Relationship (QSAR) framework with other 2D descriptors. Accordingly Genetic algorithm and multiple linear regression investigation were engaged to find the finest QSAR equation that has the best predictive power r 262 2 = 0.70, F = 119.14, r LOO 2 = 0.693, r PRESS 2 against 66 external test inhibitors = 0.71 q2 = 0.55. Three different pharmacophores appeared in the successful QSAR equation this represents three different binding modes for inhibitors within the Pim-1 kinase binding pocket. Pharmacophoric models were later used to screen compounds within the National Cancer Institute database. Several low micromolar Pim-1 Kinase inhibitors were captured. The most potent hits show IC50 values of 0.77 and 1.03 µM. Also, upon analyzing the successful QSAR Equation we found that some polycyclic aromatic electron-rich structures namely 6-Chloro-2-methoxy-acridine can be considered as putative hits for Pim-1 kinase inhibition.

  16. Sibiriline, a new small chemical inhibitor of receptor-interacting protein kinase 1, prevents immune-dependent hepatitis.

    Science.gov (United States)

    Le Cann, Fabienne; Delehouzé, Claire; Leverrier-Penna, Sabrina; Filliol, Aveline; Comte, Arnaud; Delalande, Olivier; Desban, Nathalie; Baratte, Blandine; Gallais, Isabelle; Piquet-Pellorce, Claire; Faurez, Florence; Bonnet, Marion; Mettey, Yvette; Goekjian, Peter; Samson, Michel; Vandenabeele, Peter; Bach, Stéphane; Dimanche-Boitrel, Marie-Thérèse

    2017-09-01

    Necroptosis is a regulated form of cell death involved in several disease models including in particular liver diseases. Receptor-interacting protein kinases, RIPK1 and RIPK3, are the main serine/threonine kinases driving this cell death pathway. We screened a noncommercial, kinase-focused chemical library which allowed us to identify Sibiriline as a new inhibitor of necroptosis induced by tumor necrosis factor (TNF) in Fas-associated protein with death domain (FADD)-deficient Jurkat cells. Moreover, Sib inhibits necroptotic cell death induced by various death ligands in human or mouse cells while not protecting from caspase-dependent apoptosis. By using competition binding assay and recombinant kinase assays, we demonstrated that Sib is a rather specific competitive RIPK1 inhibitor. Molecular docking analysis shows that Sib is trapped closed to human RIPK1 adenosine triphosphate-binding site in a relatively hydrophobic pocket locking RIPK1 in an inactive conformation. In agreement with its RIPK1 inhibitory property, Sib inhibits both TNF-induced RIPK1-dependent necroptosis and RIPK1-dependent apoptosis. Finally, Sib protects mice from concanavalin A-induced hepatitis. These results reveal the small-molecule Sib as a new RIPK1 inhibitor potentially of interest for the treatment of immune-dependent hepatitis. © 2017 Federation of European Biochemical Societies.

  17. RhoA: A therapeutic target for chronic myeloid leukemia

    Directory of Open Access Journals (Sweden)

    Molli Poonam R

    2012-03-01

    Full Text Available Abstract Background Chronic Myeloid Leukemia (CML is a malignant pluripotent stem cells disorder of myeloid cells. In CML patients, polymorphonuclear leukocytes (PMNL the terminally differentiated cells of myeloid series exhibit defects in several actin dependent functions such as adhesion, motility, chemotaxis, agglutination, phagocytosis and microbicidal activities. A definite and global abnormality was observed in stimulation of actin polymerization in CML PMNL. Signalling molecules ras and rhoGTPases regulate spatial and temporal polymerization of actin and thus, a broad range of physiological processes. Therefore, status of these GTPases as well as actin was studied in resting and fMLP stimulated normal and CML PMNL. Methods To study expression of GTPases and actin, Western blotting and flow cytometry analysis were done, while spatial expression and colocalization of these proteins were studied by using laser confocal microscopy. To study effect of inhibitors on cell proliferation CCK-8 assay was done. Significance of differences in expression of proteins within the samples and between normal and CML was tested by using Wilcoxon signed rank test and Mann-Whitney test, respectively. Bivariate and partial correlation analyses were done to study relationship between all the parameters. Results In CML PMNL, actin expression and its architecture were altered and stimulation of actin polymerization was absent. Differences were also observed in expression, organization or stimulation of all the three GTPases in normal and CML PMNL. In normal PMNL, ras was the critical GTPase regulating expression of rhoGTPases and actin and actin polymerization. But in CML PMNL, rhoA took a central place. In accordance with these, treatment with rho/ROCK pathway inhibitors resulted in specific growth inhibition of CML cell lines. Conclusions RhoA has emerged as the key molecule responsible for functional defects in CML PMNL and therefore can be used as a

  18. Angiotensin II induces reorganization of the actin cytoskeleton and myosin light-chain phosphorylation in podocytes through rho/ROCK-signaling pathway

    NARCIS (Netherlands)

    Wang, Siyuan; Chen, Cheng; Su, Ke; Zha, Dongqing; Liang, Wei; Hillebrands, J L; van Goor, Harry; Ding, Guohua

    2016-01-01

    Aims In the present study, we have evaluated the effect of angiotensin II (Ang II) on actin cytoskeleton reorganization and myosin light-chain (MLC) phosphorylation in podocytes to demonstrate whether the Rho/Rho-associated coiled kinase (ROCK) pathway is involved podocyte injury. Methods Eighteen

  19. A bacterial cytotoxin identifies the RhoA exchange factor Net1 as a key effector in the response to DNA damage.

    Directory of Open Access Journals (Sweden)

    Lina Guerra

    Full Text Available BACKGROUND: Exposure of adherent cells to DNA damaging agents, such as the bacterial cytolethal distending toxin (CDT or ionizing radiations (IR, activates the small GTPase RhoA, which promotes the formation of actin stress fibers and delays cell death. The signalling intermediates that regulate RhoA activation and promote cell survival are unknown. PRINCIPAL FINDINGS: We demonstrate that the nuclear RhoA-specific Guanine nucleotide Exchange Factor (GEF Net1 becomes dephosphorylated at a critical inhibitory site in cells exposed to CDT or IR. Expression of a dominant negative Net1 or Net1 knock down by iRNA prevented RhoA activation, inhibited the formation of stress fibers, and enhanced cell death, indicating that Net1 activation is required for this RhoA-mediated responses to genotoxic stress. The Net1 and RhoA-dependent signals involved activation of the Mitogen-Activated Protein Kinase p38 and its downstream target MAPK-activated protein kinase 2. SIGNIFICANCE: Our data highlight the importance of Net1 in controlling RhoA and p38 MAPK mediated cell survival in cells exposed to DNA damaging agents and illustrate a molecular pathway whereby chronic exposure to a bacterial toxin may promote genomic instability.

  20. Leveraging the Pre-DFG Residue Thr-406 To Obtain High Kinase Selectivity in an Aminopyrazole-Type PAK1 Inhibitor Series.

    Science.gov (United States)

    Rudolph, Joachim; Aliagas, Ignacio; Crawford, James J; Mathieu, Simon; Lee, Wendy; Chao, Qi; Dong, Ping; Rouge, Lionel; Wang, Weiru; Heise, Christopher; Murray, Lesley J; La, Hank; Liu, Yanzhou; Manning, Gerard; Diederich, François; Hoeflich, Klaus P

    2015-06-11

    To increase kinase selectivity in an aminopyrazole-based PAK1 inhibitor series, analogues were designed to interact with the PAK1 deep-front pocket pre-DFG residue Thr-406, a residue that is hydrophobic in most kinases. This goal was achieved by installing lactam head groups to the aminopyrazole hinge binding moiety. The corresponding analogues represent the most kinase selective ATP-competitive Group I PAK inhibitors described to date. Hydrogen bonding with the Thr-406 side chain was demonstrated by X-ray crystallography, and inhibitory activities, particularly against kinases with hydrophobic pre-DFG residues, were mitigated. Leveraging hydrogen bonding side chain interactions with polar pre-DFG residues is unprecedented, and similar strategies should be applicable to other appropriate kinases.

  1. Tyrosine Kinase Inhibitors Induced Thyroid Dysfunction: A Review of Its Incidence, Pathophysiology, Clinical Relevance, and Treatment

    Directory of Open Access Journals (Sweden)

    Hala Ahmadieh

    2013-01-01

    Full Text Available Tyrosine kinase inhibitors (TKI belong to a new class of molecular multitargeted anticancer therapy which targets different growth factor receptors and hence attenuates cancer cell survival and growth. Since their introduction as adjunct treatment for renal cell carcinoma and gastrointestinal stromal tumors (GIST, a number of reports have demonstrated that TKI can induce thyroid dysfunction which was especially more common with sunitinib maleate. Many mechanisms with respect to this adverse effect of tyrosine kinase inhibitors have been proposed including their induction of thyroiditis, capillary regression in the thyroid gland, antithyroid peroxidase antibody production, and their ability to decrease iodine uptake by the thyroid gland. Of interest is the observation that TKI-induced thyroid dysfunction may actually be protective as it was shown to improve overall survival, and it was suggested that it may have a prognostic value. Followup on thyroid function tests while patients are maintained on tyrosine kinase inhibitor is strongly recommended. When thyroid dysfunction occurs, appropriate treatment should be individualized depending on patients symptoms and thyroid stimulating hormone level.

  2. An Investigation of Molecular Docking and Molecular Dynamic Simulation on Imidazopyridines as B-Raf Kinase Inhibitors

    Directory of Open Access Journals (Sweden)

    Huiding Xie

    2015-11-01

    Full Text Available In the recent cancer treatment, B-Raf kinase is one of key targets. Nowadays, a group of imidazopyridines as B-Raf kinase inhibitors have been reported. In order to investigate the interaction between this group of inhibitors and B-Raf kinase, molecular docking, molecular dynamic (MD simulation and binding free energy (ΔGbind calculation were performed in this work. Molecular docking was carried out to identify the key residues in the binding site, and MD simulations were performed to determine the detail binding mode. The results obtained from MD simulation reveal that the binding site is stable during the MD simulations, and some hydrogen bonds (H-bonds in MD simulations are different from H-bonds in the docking mode. Based on the obtained MD trajectories, ΔGbind was computed by using Molecular Mechanics Generalized Born Surface Area (MM-GBSA, and the obtained energies are consistent with the activities. An energetic analysis reveals that both electrostatic and van der Waals contributions are important to ΔGbind, and the unfavorable polar solvation contribution results in the instability of the inhibitor with the lowest activity. These results are expected to understand the binding between B-Raf and imidazopyridines and provide some useful information to design potential B-Raf inhibitors.

  3. High energy photoproduction of the rho and rho' vector mesons

    International Nuclear Information System (INIS)

    Bronstein, J.M.

    1977-01-01

    In an experiment in the broad band photon beam at Fermilab diffractive production of 2π + and 4π +- states from Be, Al, Cu, and Pb targets was observed. The 2π + data are dominated by the rho(770) and the 4π +- is dominated by the rho'(1500). The energy dependence of rho photoproduction from Be was measured, and no evidence was seen for energy variation of the forward cross section in the range 30 to 160 GeV. The forward cross section is consistent with its average value d sigma/dtlt. slash 0 = 3.42 +- 0.28 μb/GeV 2 over the entire range. For the /sub rho'// a mass of 1487 +- 20 MeV and a width of 675 +- 60 MeV are obtained. All quoted errors are statistical. A standard optical model analysis of the A dependence of the rho and rho'/ photoproduction yields the following results. f/sub rho'/ 2 /f/sub rho/ 2 = 3.7 +- 0.7, sigma /sub rho'//sigma /sub rho/ = 1.05 +- 0.18. Results for the photon coupling constants are in good agreement with GVMD and with the e + e - storage ring results. The approximate equality of the rho-nucleon and rho'-nucleon total cross sections is inconsistent with the diagonal version of GVMD and provides strong motivation for including transitions between different vector mesons in GVMD

  4. Inflammatory Signaling by NOD-RIPK2 Is Inhibited by Clinically Relevant Type II Kinase Inhibitors.

    Science.gov (United States)

    Canning, Peter; Ruan, Qui; Schwerd, Tobias; Hrdinka, Matous; Maki, Jenny L; Saleh, Danish; Suebsuwong, Chalada; Ray, Soumya; Brennan, Paul E; Cuny, Gregory D; Uhlig, Holm H; Gyrd-Hansen, Mads; Degterev, Alexei; Bullock, Alex N

    2015-09-17

    RIPK2 mediates pro-inflammatory signaling from the bacterial sensors NOD1 and NOD2, and is an emerging therapeutic target in autoimmune and inflammatory diseases. We observed that cellular RIPK2 can be potently inhibited by type II inhibitors that displace the kinase activation segment, whereas ATP-competitive type I inhibition was only poorly effective. The most potent RIPK2 inhibitors were the US Food and Drug Administration-approved drugs ponatinib and regorafenib. Their mechanism of action was independent of NOD2 interaction and involved loss of downstream kinase activation as evidenced by lack of RIPK2 autophosphorylation. Notably, these molecules also blocked RIPK2 ubiquitination and, consequently, inflammatory nuclear factor κB signaling. In monocytes, the inhibitors selectively blocked NOD-dependent tumor necrosis factor production without affecting lipopolysaccharide-dependent pathways. We also determined the first crystal structure of RIPK2 bound to ponatinib, and identified an allosteric site for inhibitor development. These results highlight the potential for type II inhibitors to treat indications of RIPK2 activation as well as inflammation-associated cancers. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Overall survival after immunotherapy, tyrosine kinase inhibitors and surgery in treatment of metastatic renal cell cancer

    DEFF Research Database (Denmark)

    de Lichtenberg, Trine Honnens; Hermann, Gregers G.; Rorth, Mikael

    2014-01-01

    Abstract Objective. The aim of this study was to evaluate overall survival (OS) after treatment of metastatic renal cell carcinoma (mRCC) following the introduction of tyrosine kinase inhibitors (TKIs) and mammalian target of rapamycin (mTOR) inhibitors. Material and methods. One-hundred and forty...

  6. Tofacitinib and analogs as inhibitors of the histone kinase PRK1 (PKN1).

    Science.gov (United States)

    Ostrovskyi, Dmytro; Rumpf, Tobias; Eib, Julia; Lumbroso, Alexandre; Slynko, Inna; Klaeger, Susan; Heinzlmeir, Stephanie; Forster, Michael; Gehringer, Matthias; Pfaffenrot, Ellen; Bauer, Silke Mona; Schmidtkunz, Karin; Wenzler, Sandra; Metzger, Eric; Kuster, Bernhard; Laufer, Stefan; Schüle, Roland; Sippl, Wolfgang; Breit, Bernhard; Jung, Manfred

    2016-09-01

    The histone kinase PRK1 has been identified as a potential target to combat prostate cancer but selective PRK1 inhibitors are lacking. The US FDA -approved JAK1-3 inhibitor tofacitinib also potently inhibits PRK1 in vitro. We show that tofacitinib also inhibits PRK1 in a cellular setting. Using tofacitinib as a starting point for structure-activity relationship studies, we identified a more potent and another more selective PRK1 inhibitor compared with tofacitinib. Furthermore, we found two potential PRK1/JAK3-selectivity hotspots. The identified inhibitors and the selectivity hotspots lay the basis for the development of selective PRK1 inhibitors. The identification of PRK1, but also of other cellular tofacitinib targets, has implications on its clinical use and on future development of tofacitinib-like JAK inhibitors. [Formula: see text].

  7. Development of Pharmacophore Model for Indeno[1,2-b]indoles as Human Protein Kinase CK2 Inhibitors and Database Mining

    Directory of Open Access Journals (Sweden)

    Samer Haidar

    2017-01-01

    Full Text Available Protein kinase CK2, initially designated as casein kinase 2, is an ubiquitously expressed serine/threonine kinase. This enzyme, implicated in many cellular processes, is highly expressed and active in many tumor cells. A large number of compounds has been developed as inhibitors comprising different backbones. Beside others, structures with an indeno[1,2-b]indole scaffold turned out to be potent new leads. With the aim of developing new inhibitors of human protein kinase CK2, we report here on the generation of common feature pharmacophore model to further explain the binding requirements for human CK2 inhibitors. Nine common chemical features of indeno[1,2-b]indole-type CK2 inhibitors were determined using MOE software (Chemical Computing Group, Montreal, Canada. This pharmacophore model was used for database mining with the aim to identify novel scaffolds for developing new potent and selective CK2 inhibitors. Using this strategy several structures were selected by searching inside the ZINC compound database. One of the selected compounds was bikaverin (6,11-dihydroxy-3,8-dimethoxy-1-methylbenzo[b]xanthene-7,10,12-trione, a natural compound which is produced by several kinds of fungi. This compound was tested on human recombinant CK2 and turned out to be an active inhibitor with an IC50 value of 1.24 µM.

  8. Selectivity analysis of protein kinase CK2 inhibitors DMAT, TBB and resorufin in cisplatin-induced stress responses

    DEFF Research Database (Denmark)

    Fritz, Gerhard; Issinger, Olaf-Georg; Olsen, Birgitte Brinkmann

    2009-01-01

    Targeting protein kinases as a therapeutic approach to treat various diseases, especially cancer is currently a fast growing business. Although many inhibitors are available, exhibiting remarkable potency, the major challenge is their selectivity. Here we show that the protein kinase CK2 inhibito...

  9. Systems biology analysis of mitogen activated protein kinase inhibitor resistance in malignant melanoma.

    Science.gov (United States)

    Zecena, Helma; Tveit, Daniel; Wang, Zi; Farhat, Ahmed; Panchal, Parvita; Liu, Jing; Singh, Simar J; Sanghera, Amandeep; Bainiwal, Ajay; Teo, Shuan Y; Meyskens, Frank L; Liu-Smith, Feng; Filipp, Fabian V

    2018-04-04

    Kinase inhibition in the mitogen activated protein kinase (MAPK) pathway is a standard therapy for cancer patients with activating BRAF mutations. However, the anti-tumorigenic effect and clinical benefit are only transient, and tumors are prone to treatment resistance and relapse. To elucidate mechanistic insights into drug resistance, we have established an in vitro cellular model of MAPK inhibitor resistance in malignant melanoma. The cellular model evolved in response to clinical dosage of the BRAF inhibitor, vemurafenib, PLX4032. We conducted transcriptomic expression profiling using RNA-Seq and RT-qPCR arrays. Pathways of melanogenesis, MAPK signaling, cell cycle, and metabolism were significantly enriched among the set of differentially expressed genes of vemurafenib-resistant cells vs control. The underlying mechanism of treatment resistance and pathway rewiring was uncovered to be based on non-genomic adaptation and validated in two distinct melanoma models, SK-MEL-28 and A375. Both cell lines have activating BRAF mutations and display metastatic potential. Downregulation of dual specific phosphatases, tumor suppressors, and negative MAPK regulators reengages mitogenic signaling. Upregulation of growth factors, cytokines, and cognate receptors triggers signaling pathways circumventing BRAF blockage. Further, changes in amino acid and one-carbon metabolism support cellular proliferation despite MAPK inhibitor treatment. In addition, treatment-resistant cells upregulate pigmentation and melanogenesis, pathways which partially overlap with MAPK signaling. Upstream regulator analysis discovered significant perturbation in oncogenic forkhead box and hypoxia inducible factor family transcription factors. The established cellular models offer mechanistic insight into cellular changes and therapeutic targets under inhibitor resistance in malignant melanoma. At a systems biology level, the MAPK pathway undergoes major rewiring while acquiring inhibitor resistance

  10. Pim kinase inhibition sensitizes FLT3-ITD acute myeloid leukemia cells to topoisomerase 2 inhibitors through increased DNA damage and oxidative stress

    Science.gov (United States)

    Doshi, Kshama A.; Trotta, Rossana; Natarajan, Karthika; Rassool, Feyruz V.; Tron, Adriana E.; Huszar, Dennis; Perrotti, Danilo; Baer, Maria R.

    2016-01-01

    Internal tandem duplication of fms-like tyrosine kinase-3 (FLT3-ITD) is frequent (30 percent) in acute myeloid leukemia (AML), and is associated with short disease-free survival following chemotherapy. The serine threonine kinase Pim-1 is a pro-survival oncogene transcriptionally upregulated by FLT3-ITD that also promotes its signaling in a positive feedback loop. Thus inhibiting Pim-1 represents an attractive approach in targeting FLT3-ITD cells. Indeed, co-treatment with the pan-Pim kinase inhibitor AZD1208 or expression of a kinase-dead Pim-1 mutant sensitized FLT3-ITD cell lines to apoptosis triggered by chemotherapy drugs including the topoisomerase 2 inhibitors daunorubicin, etoposide and mitoxantrone, but not the nucleoside analog cytarabine. AZD1208 sensitized primary AML cells with FLT3-ITD to topoisomerase 2 inhibitors, but did not sensitize AML cells with wild-type FLT3 or remission bone marrow cells, supporting a favorable therapeutic index. Mechanistically, the enhanced apoptosis observed with AZD1208 and topoisomerase 2 inhibitor combination treatment was associated with increased DNA double-strand breaks and increased levels of reactive oxygen species (ROS), and co-treatment with the ROS scavenger N-acetyl cysteine rescued FLT3-ITD cells from AZD1208 sensitization to topoisomerase 2 inhibitors. Our data support testing of Pim kinase inhibitors with topoisomerase 2 inhibitors, but not with cytarabine, to improve treatment outcomes in AML with FLT3-ITD. PMID:27374090

  11. Combining the pan-aurora kinase inhibitor AMG 900 with histone deacetylase inhibitors enhances antitumor activity in prostate cancer

    International Nuclear Information System (INIS)

    Paller, Channing J; Wissing, Michel D; Mendonca, Janet; Sharma, Anup; Kim, Eugene; Kim, Hea-Soo; Kortenhorst, Madeleine S Q; Gerber, Stephanie; Rosen, Marc; Shaikh, Faraz; Zahurak, Marianna L; Rudek, Michelle A; Hammers, Hans; Rudin, Charles M; Carducci, Michael A; Kachhap, Sushant K

    2014-01-01

    Histone deacetylase inhibitors (HDACIs) are being tested in clinical trials for the treatment of solid tumors. While most studies have focused on the reexpression of silenced tumor suppressor genes, a number of genes/pathways are downregulated by HDACIs. This provides opportunities for combination therapy: agents that further disable these pathways through inhibition of residual gene function are speculated to enhance cell death in combination with HDACIs. A previous study from our group indicated that mitotic checkpoint kinases such as PLK1 and Aurora A are downregulated by HDACIs. We used in vitro and in vivo xenograft models of prostate cancer (PCA) to test whether combination of HDACIs with the pan-aurora kinase inhibitor AMG 900 can synergistically or additively kill PCA cells. AMG 900 and HDACIs synergistically decreased cell proliferation activity and clonogenic survival in DU-145, LNCaP, and PC3 PCA cell lines compared to single-agent treatment. Cellular senescence, polyploidy, and apoptosis was significantly increased in all cell lines after combination treatment. In vivo xenograft studies indicated decreased tumor growth and decreased aurora B kinase activity in mice treated with low-dose AMG 900 and vorinostat compared to either agent alone. Pharmacodynamics was assessed by scoring for phosphorylated histone H3 through immunofluorescence. Our results indicate that combination treatment with low doses of AMG 900 and HDACIs could be a promising therapy for future clinical trials against PCA

  12. Identification and Characterization of Amlexanox as a G Protein-Coupled Receptor Kinase 5 Inhibitor

    Directory of Open Access Journals (Sweden)

    Kristoff T. Homan

    2014-10-01

    Full Text Available G protein-coupled receptor kinases (GRKs have been implicated in human diseases ranging from heart failure to diabetes. Previous studies have identified several compounds that selectively inhibit GRK2, such as paroxetine and balanol. Far fewer selective inhibitors have been reported for GRK5, a target for the treatment of cardiac hypertrophy, and the mechanism of action of reported compounds is unknown. To identify novel scaffolds that selectively inhibit GRK5, a differential scanning fluorometry screen was used to probe a library of 4480 compounds. The best hit was amlexanox, an FDA-approved anti-inflammatory, anti-allergic immunomodulator. The crystal structure of amlexanox in complex with GRK1 demonstrates that its tricyclic aromatic ring system forms ATP-like interactions with the hinge of the kinase domain, which is likely similar to how this drug binds to IκB kinase ε (IKKε, another kinase known to be inhibited by this compound. Amlexanox was also able to inhibit myocyte enhancer factor 2 transcriptional activity in neonatal rat ventricular myocytes in a manner consistent with GRK5 inhibition. The GRK1 amlexanox structure thus serves as a springboard for the rational design of inhibitors with improved potency and selectivity for GRK5 and IKKε.

  13. Differential effects on cell motility, embryonic stem cell self-renewal and senescence by diverse Src kinase family inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Tamm, Christoffer, E-mail: christoffer.tamm@imbim.uu.se; Galito, Sara Pijuan, E-mail: sara.pijuan@imbim.uu.se; Anneren, Cecilia, E-mail: cecilia.anneren@imbim.uu.se

    2012-02-15

    The Src family of non-receptor tyrosine kinases (SFKs) has been shown to play an intricate role in embryonic stem (ES) cell maintenance. In the present study we have focused on the underlying molecular mechanisms responsible for the vastly different effects induced by various commonly used SFK inhibitors. We show that several diverse cell types, including fibroblasts completely lacking SFKs, cannot undergo mitosis in response to SU6656 and that this is caused by an unselective inhibition of Aurora kinases. In contrast, PP2 and PD173952 block motility immediately upon exposure and forces cells to grow in dense colonies. The subsequent halt in proliferation of fibroblast and epithelial cells in the center of the colonies approximately 24 h post-treatment appears to be caused by cell-to-cell contact inhibition rather than a direct effect of SFK kinase inhibition. Interestingly, in addition to generating more homogenous and dense ES cell cultures, without any diverse effect on proliferation, PP2 and PD173652 also promote ES cell self-renewal by reducing the small amount of spontaneous differentiation typically observed under standard ES cell culture conditions. These effects could not be mirrored by the use of Gleevec, a potent inhibitor of c-Abl and PDGFR kinases that are also inhibited by PP2. -- Highlights: Black-Right-Pointing-Pointer SFK inhibitor SU6656 induces senescence in mouse ES cells. Black-Right-Pointing-Pointer SU6656 inhibits mitosis in a SFK-independent manner via cross-selectivity for Aurora kinases. Black-Right-Pointing-Pointer SFK inhibitor PP2 impairs cell motility in various cell lines, including mouse ES cells. Black-Right-Pointing-Pointer Ensuing impeded motility, PP2 inhibits proliferation of various cells lines except for mouse ES cells. Black-Right-Pointing-Pointer SFK inhibitors PP2 and PD173952 impede spontaneous differentiation in standard mouse ES culture maintenance.

  14. Differential effects on cell motility, embryonic stem cell self-renewal and senescence by diverse Src kinase family inhibitors

    International Nuclear Information System (INIS)

    Tamm, Christoffer; Galitó, Sara Pijuan; Annerén, Cecilia

    2012-01-01

    The Src family of non-receptor tyrosine kinases (SFKs) has been shown to play an intricate role in embryonic stem (ES) cell maintenance. In the present study we have focused on the underlying molecular mechanisms responsible for the vastly different effects induced by various commonly used SFK inhibitors. We show that several diverse cell types, including fibroblasts completely lacking SFKs, cannot undergo mitosis in response to SU6656 and that this is caused by an unselective inhibition of Aurora kinases. In contrast, PP2 and PD173952 block motility immediately upon exposure and forces cells to grow in dense colonies. The subsequent halt in proliferation of fibroblast and epithelial cells in the center of the colonies approximately 24 h post-treatment appears to be caused by cell-to-cell contact inhibition rather than a direct effect of SFK kinase inhibition. Interestingly, in addition to generating more homogenous and dense ES cell cultures, without any diverse effect on proliferation, PP2 and PD173652 also promote ES cell self-renewal by reducing the small amount of spontaneous differentiation typically observed under standard ES cell culture conditions. These effects could not be mirrored by the use of Gleevec, a potent inhibitor of c-Abl and PDGFR kinases that are also inhibited by PP2. -- Highlights: ► SFK inhibitor SU6656 induces senescence in mouse ES cells. ► SU6656 inhibits mitosis in a SFK-independent manner via cross-selectivity for Aurora kinases. ► SFK inhibitor PP2 impairs cell motility in various cell lines, including mouse ES cells. ► Ensuing impeded motility, PP2 inhibits proliferation of various cells lines except for mouse ES cells. ► SFK inhibitors PP2 and PD173952 impede spontaneous differentiation in standard mouse ES culture maintenance.

  15. Measurement of exclusive $\\rho^{+}\\rho^{-}$ production in mid-virtuality two-photon interactions and study of the $\\gamma \\gamma^{*} \\to \\rho\\rho$ process at LEP

    CERN Document Server

    Achard, P.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M.G.; Anderhub, H.; Andreev, Valery P.; Anselmo, F.; Arefiev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S.V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillere, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B.L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J.J.; Blyth, S.C.; Bobbink, G.J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J.G.; Brochu, F.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y.H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G.M.; Chen, H.F.; Chen, H.S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; de Asmundis, R.; Deglon, P.; Debreczeni, J.; Degre, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M.T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F.J.; Extermann, P.; Falagan, M.A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J.H.; Filthaut, F.; Fisher, P.H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Iouri; Ganguli, S.N.; Garcia-Abia, Pablo; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z.F.; Grenier, Gerald Jean; Grimm, O.; Gruenewald, M.W.; Guida, M.; Gupta, V.K.; Gurtu, A.; Gutay, L.J.; Haas, D.; Hatzifotiadou, D.; Hebbeker, T.; Herve, Alain; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S.R.; Jin, B.N.; Jindal, P.; Jones, Lawrence W.; de Jong, P.; Josa-Mutuberria, I.; Kaur, M.; Kienzle-Focacci, M.N.; Kim, J.K.; Kirkby, Jasper; Kittel, W.; Klimentov, A.; Konig, A.C.; Kopal, M.; Koutsenko, V.; Kraber, M.; Kraemer, R.W.; Kruger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J.M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C.H.; Lin, W.T.; Linde, F.L.; Lista, L.; Liu, Z.A.; Lohmann, W.; Longo, E.; Lu, Y.S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W.G.; Malgeri, L.; Malinin, A.; Mana, C.; Mans, J.; Martin, J.P.; Marzano, F.; Mazumdar, K.; McNeil, R.R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W.J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G.B.; Muanza, G.S.; Muijs, A.J.M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Kluge, Hannelies; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, Thomas Cantzon; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroue, P.A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofiev, D.; Rahal-Callot, G.; Rahaman, Mohammad Azizur; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, Keith; Roe, B.P.; Romero, L.; Rosca, A.; Rosemann, C.; Rosenbleck, C.; Rosier-Lees, S.; Roth, Stefan; Rubio, J.A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schafer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D.J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D.P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L.Z.; Sushkov, S.; Suter, H.; Swain, J.D.; Szillasi, Z.; Tang, X.W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, Charles; Ting, Samuel C.C.; Ting, S.M.; Tonwar, S.C.; Toth, J.; Tully, C.; Tung, K.L.; Ulbricht, J.; Valente, E.; Van de Walle, R.T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobiev, I.; Vorobyov, A.A.; Wadhwa, M.; Wang, Q.; Wang, X.L.; Wang, Z.M.; Weber, M.; Wynhoff, S.; Xia, L.; Xu, Z.Z.; Yamamoto, J.; Yang, B.Z.; Yang, C.G.; Yang, H.J.; Yang, M.; Yeh, S.C.; Zalite, An.; Zalite, Yu.; Zhang, Z.P.; Zhao, J.; Zhu, G.Y.; Zhu, R.Y.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.; Zoller, M.

    2005-01-01

    Exclusive rho+rho- production in two-photon collisions between a quasi-real photon, gamma, and a mid-virtuality photon, gamma*, is studied with data collected at LEP at centre-of-mass energies root(s)=183-209GeV with a total integrated luminosity of 684.8pb^-1. The cross section of the gamma gamma* -> rho+ rho- process is determined as a function of the photon virtuality, Q^2, and the two-photon centre-of-mass energy, W_gg, in the kinematic region: 0.2GeV^2 rho rho process over the Q^2-region 0.2GeV^2 < Q^2 < 30 GeV^2.

  16. Recent Advances of Colony-Stimulating Factor-1 Receptor (CSF-1R) Kinase and Its Inhibitors.

    Science.gov (United States)

    El-Gamal, Mohammed I; Al-Ameen, Shahad K; Al-Koumi, Dania M; Hamad, Mawadda G; Jalal, Nouran A; Oh, Chang-Hyun

    2018-01-17

    Colony stimulation factor-1 receptor (CSF-1R), which is also known as FMS kinase, plays an important role in initiating inflammatory, cancer, and bone disorders when it is overstimulated by its ligand, CSF-1. Innate immunity, as well as macrophage differentiation and survival, are regulated by the stimulation of the CSF-1R. Another ligand, interlukin-34 (IL-34), was recently reported to activate the CSF-1R receptor in a different manner. The relationship between CSF-1R and microglia has been reviewed. Both CSF-1 antibodies and small molecule CSF-1R kinase inhibitors have now been tested in animal models and in humans. In this Perspective, we discuss the role of CSF-1 and IL-34 in producing cancer, bone disorders, and inflammation. We also review the newly discovered and improved small molecule kinase inhibitors and monoclonal antibodies that have shown potent activity toward CSF-1R, reported from 2012 until 2017.

  17. The TAM-family receptor Mer mediates production of HGF through the RhoA-dependent pathway in response to apoptotic cells.

    Science.gov (United States)

    Park, Hyun-Jung; Baen, Ji-Yeon; Lee, Ye-Ji; Choi, Youn-Hee; Kang, Jihee Lee

    2012-08-01

    The TAM receptor protein tyrosine kinases Tyro3, Axl, and Mer play important roles in macrophage function. We investigated the roles of the TAM receptors in mediating the induction of hepatocyte growth factor (HGF) during the interaction of macrophages with apoptotic cells. Mer-specific neutralizing antibody, small interfering RNA (siRNA), and a recombinant Mer protein (Mer/Fc) inhibited HGF mRNA and protein expression, as well as activation of RhoA, Akt, and specific mitogen-activated protein (MAP) kinases in response to apoptotic cells. Inhibition of Axl or Tyro3 with specific antibodies, siRNA, or Fc-fusion proteins did not prevent apoptotic cell-induced HGF mRNA and protein expression and did not inhibit activation of the postreceptor signaling molecules RhoA and certain MAP kinases, including extracellular signal-regulated protein kinase and c-Jun NH(2)-terminal kinase. However, Axl- and Tyro3-specific blockers did inhibit the activation of Akt and p38 MAP kinase in response to apoptotic cells. In addition, none of the TAM receptors mediated the effects of apoptotic cells on transforming growth factor-β or epidermal growth factor mRNA expression. However, they were involved in the induction of vascular endothelial growth factor mRNA expression. Our data provide evidence that when macrophages interact with apoptotic cells, only Mer of the TAM-family receptors is responsible for mediating transcriptional HGF production through a RhoA-dependent pathway.

  18. In silico design and biological evaluation of a dual specificity kinase inhibitor targeting cell cycle progression and angiogenesis.

    Science.gov (United States)

    Latham, Antony M; Kankanala, Jayakanth; Fearnley, Gareth W; Gage, Matthew C; Kearney, Mark T; Homer-Vanniasinkam, Shervanthi; Wheatcroft, Stephen B; Fishwick, Colin W G; Ponnambalam, Sreenivasan

    2014-01-01

    Protein kinases play a central role in tumor progression, regulating fundamental processes such as angiogenesis, proliferation and metastasis. Such enzymes are an increasingly important class of drug target with small molecule kinase inhibitors being a major focus in drug development. However, balancing drug specificity and efficacy is problematic with off-target effects and toxicity issues. We have utilized a rational in silico-based approach to demonstrate the design and study of a novel compound that acts as a dual inhibitor of vascular endothelial growth factor receptor 2 (VEGFR2) and cyclin-dependent kinase 1 (CDK1). This compound acts by simultaneously inhibiting pro-angiogenic signal transduction and cell cycle progression in primary endothelial cells. JK-31 displays potent in vitro activity against recombinant VEGFR2 and CDK1/cyclin B proteins comparable to previously characterized inhibitors. Dual inhibition of the vascular endothelial growth factor A (VEGF-A)-mediated signaling response and CDK1-mediated mitotic entry elicits anti-angiogenic activity both in an endothelial-fibroblast co-culture model and a murine ex vivo model of angiogenesis. We deduce that JK-31 reduces the growth of both human endothelial cells and human breast cancer cells in vitro. This novel synthetic molecule has broad implications for development of similar multi-kinase inhibitors with anti-angiogenic and anti-cancer properties. In silico design is an attractive and innovative method to aid such drug discovery.

  19. Inhibitors of JAK-family kinases: an update on the patent literature 2013-2015, part 2.

    Science.gov (United States)

    Kettle, Jason G; Åstrand, Annika; Catley, Matthew; Grimster, Neil P; Nilsson, Magnus; Su, Qibin; Woessner, Richard

    2017-02-01

    Janus kinases (JAKs) are a family of four enzymes; JAK1, JAK2, JAK3 and tyrosine kinase 2 (TYK2) that are critical in cytokine signalling and are strongly linked to both cancer and inflammatory diseases. There are currently two launched JAK inhibitors for the treatment of human conditions: tofacitinib for Rheumatoid arthritis (RA) and ruxolitinib for myeloproliferative neoplasms including intermediate or high risk myelofibrosis and polycythemia vera. Areas covered: This review covers patents claiming activity against one or more JAK family members in the period 2013-2015 inclusive, and covers 95 patents from 42 applicants, split over two parts. The authors have ordered recent patents according to the primary applicant's name, with part 2 covering J through Z. Expert opinion: Inhibition of JAK-family kinases is an area of growing interest, catalysed by the maturity of data on marketed inhibitors ruxolitinib and tofacitinib in late stage clinical trials. Many applicants are pursuing traditional fast-follower strategies around these inhibitors, with a range of chemical strategies adopted. The challenge will be to show sufficient differentiation to the originator compounds, since dose limiting toxicities with such agents appear to be on target and mechanism-related and also considering that such agents may be available as generic compounds by the time follower agents reach market.

  20. Inhibitors of JAK-family kinases: an update on the patent literature 2013-2015, part 1.

    Science.gov (United States)

    Kettle, Jason G; Åstrand, Annika; Catley, Matthew; Grimster, Neil P; Nilsson, Magnus; Su, Qibin; Woessner, Richard

    2017-02-01

    Janus kinases (JAKs) are a family of four enzymes; JAK1, JAK2, JAK3 and tyrosine kinase 2 (TYK2) that are critical in cytokine signalling and are strongly linked to both cancer and inflammatory diseases. There are currently two launched JAK inhibitors for the treatment of human conditions: tofacitinib for Rheumatoid arthritis (RA) and ruxolitinib for myeloproliferative neoplasms including intermediate or high risk myelofibrosis and polycythemia vera. Areas covered: This review covers patents claiming activity against one or more JAK family members in the period 2013-2015 inclusive, and covers 95 patents from 42 applicants, split over two parts. The authors have ordered recent patents according to the primary applicant's name, with part 1 covering A through to I. Expert opinion: Inhibition of JAK-family kinases is an area of growing interest, catalysed by the maturity of data on marketed inhibitors ruxolitinib and tofacitinib in late stage clinical trials. Many applicants are pursuing traditional fast-follower strategies around these inhibitors, with a range of chemical strategies adopted. The challenge will be to show sufficient differentiation to the originator compounds, since dose limiting toxicities with such agents appear to be on target and mechanism-related and also considering that such agents may be available as generic compounds by the time follower agents reach market.

  1. Structural characterization of nonactive site, TrkA-selective kinase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Su, Hua-Poo; Rickert, Keith; Burlein, Christine; Narayan, Kartik; Bukhtiyarova, Marina; Hurzy, Danielle M.; Stump, Craig A.; Zhang, Xufang; Reid, John; Krasowska-Zoladek, Alicja; Tummala, Srivanya; Shipman, Jennifer M.; Kornienko, Maria; Lemaire, Peter A.; Krosky, Daniel; Heller, Amanda; Achab, Abdelghani; Chamberlin, Chad; Saradjian, Peter; Sauvagnat, Berengere; Yang, Xianshu; Ziebell, Michael R.; Nickbarg, Elliott; Sanders, John M.; Bilodeau, Mark T.; Carroll, Steven S.; Lumb, Kevin J.; Soisson, Stephen M.; Henze, Darrell A.; Cooke, Andrew J. (Merck)

    2016-12-30

    Current therapies for chronic pain can have insufficient efficacy and lead to side effects, necessitating research of novel targets against pain. Although originally identified as an oncogene, Tropomyosin-related kinase A (TrkA) is linked to pain and elevated levels of NGF (the ligand for TrkA) are associated with chronic pain. Antibodies that block TrkA interaction with its ligand, NGF, are in clinical trials for pain relief. Here, we describe the identification of TrkA-specific inhibitors and the structural basis for their selectivity over other Trk family kinases. The X-ray structures reveal a binding site outside the kinase active site that uses residues from the kinase domain and the juxtamembrane region. Three modes of binding with the juxtamembrane region are characterized through a series of ligand-bound complexes. The structures indicate a critical pharmacophore on the compounds that leads to the distinct binding modes. The mode of interaction can allow TrkA selectivity over TrkB and TrkC or promiscuous, pan-Trk inhibition. This finding highlights the difficulty in characterizing the structure-activity relationship of a chemical series in the absence of structural information because of substantial differences in the interacting residues. These structures illustrate the flexibility of binding to sequences outside of—but adjacent to—the kinase domain of TrkA. This knowledge allows development of compounds with specificity for TrkA or the family of Trk proteins.

  2. Exploring the Hypersensitivity of PTEN Deleted Prostate Cancer Stem Cells to WEE1 Tyrosine Kinase Inhibitors

    Science.gov (United States)

    2015-12-01

    AWARD NUMBER: W81XWH-14-1-0251 TITLE: Exploring the Hypersensitivity of PTEN Deleted Prostate Cancer Stem Cells to WEE1 Tyrosine Kinase... Tyrosine Kinase Inhibitors 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-14-1-0251 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Kiran Mahajan 5d...ABSTRACT Central to all cycling cells-including prostate cancer stem cells- is the expression of WEE1 tyrosine kinase. WEE1 monitors duplication of

  3. Ibrutinib (PCI-32765), the first BTK (Bruton's tyrosine kinase) inhibitor in clinical trials.

    Science.gov (United States)

    Brown, Jennifer R

    2013-03-01

    Ibrutinib is a potent covalent kinase inhibitor that targets BTK. BTK, or Bruton's tyrosine kinase, is an obvious target for therapy of B cell diseases because inactivating mutations lead to B cell aplasia in humans and the disease X-linked agammaglobulinemia. Ibrutinib has modest cytotoxicity against CLL cells in vitro but also blocks trophic stimuli from the microenvironment. As with other inhibitors of the BCR pathway, ibrutinib causes rapid nodal reduction and response associated with rapid increase in lymphocytosis, which then returns to baseline over time. The ORR of ibrutinib in relapsed refractory CLL is 67 % with PFS 88 % at 15 months. In a cohort of untreated patients 65 years and over, the estimated 15 month PFS is 96 %. Registration trials have been initiated, and the difficult task that remains is to determine where in the course of CLL therapy this drug will have the greatest impact and benefit for patients.

  4. Overcoming Resistance to Inhibitors of the Akt Protein Kinase by Modulation of the Pim Kinase Pathway

    Science.gov (United States)

    2017-01-01

    v e V ia b il it y Figure 8. PC3-LN4 cells in normoxia or hypoxia were treated with Pim inhibitors. Left panel shows a Western blot and the...3728-36, PMID 25241892 4. Warfel, NA, Kraft, AS. Pim kinase (and Akt) biology and signaling in tumors. Pharmacol Ther. 2015 Jul; 151: 41 - 9. doi: 10.1016...Associated Fibroblast Biology in Prostate Cancer These studies will accelerate and significantly advance the rational development of targeted agents

  5. The evolving field of kinase inhibitors in thyroid cancer.

    Science.gov (United States)

    Marotta, V; Sciammarella, C; Vitale, M; Colao, A; Faggiano, A

    2015-01-01

    Most of the genetic events implicated in the pathogenesis of thyroid cancer (TC) involve genes with kinase activity. Thus, kinase inhibitors (KIs) are very relevant in this field. KIs are considered the most suitable treatment for patients with iodine-refractory differentiated TC; these patients comprise the subgroup with the poorer prognosis. To date, only sorafenib has been approved for this indication, but promising results have been reported with several other KIs. In particular, lenvatinib has demonstrated excellent efficacy, with both progression-free survival and objective tumour response being better than with sorafenib. Despite being considered to be well tolerated, both sorafenib and lenvatinib have shown a remarkable toxicity, which has led to dose reductions in the majority of patients and to treatment discontinuation in a significant proportion of cases. The role of KIs in differentiated TC may be revolutionised by the finding that selumetinib may restore a clinical response to radioactive iodine (RAI). Vandetanib and cabozantinib have been approved for the treatment of advanced, progressive medullary TC (MTC). Nevertheless, the toxicity of both compounds suggests their selective use in those patients with strong disease progression. Treatment with the mTOR-inhibitor everolimus, alone or in combination with somatostatin analogues, should be studied in metastatic MTC patients with slow progression of disease, these representing the vast majority of patients. KIs did not significantly impact on the clinical features of anaplastic TC (ATC). Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. How to Achieve Better Results Using PASS-Based Virtual Screening: Case Study for Kinase Inhibitors

    Directory of Open Access Journals (Sweden)

    Pavel V. Pogodin

    2018-04-01

    Full Text Available Discovery of new pharmaceutical substances is currently boosted by the possibility of utilization of the Synthetically Accessible Virtual Inventory (SAVI library, which includes about 283 million molecules, each annotated with a proposed synthetic one-step route from commercially available starting materials. The SAVI database is well-suited for ligand-based methods of virtual screening to select molecules for experimental testing. In this study, we compare the performance of three approaches for the analysis of structure-activity relationships that differ in their criteria for selecting of “active” and “inactive” compounds included in the training sets. PASS (Prediction of Activity Spectra for Substances, which is based on a modified Naïve Bayes algorithm, was applied since it had been shown to be robust and to provide good predictions of many biological activities based on just the structural formula of a compound even if the information in the training set is incomplete. We used different subsets of kinase inhibitors for this case study because many data are currently available on this important class of drug-like molecules. Based on the subsets of kinase inhibitors extracted from the ChEMBL 20 database we performed the PASS training, and then applied the model to ChEMBL 23 compounds not yet present in ChEMBL 20 to identify novel kinase inhibitors. As one may expect, the best prediction accuracy was obtained if only the experimentally confirmed active and inactive compounds for distinct kinases in the training procedure were used. However, for some kinases, reasonable results were obtained even if we used merged training sets, in which we designated as inactives the compounds not tested against the particular kinase. Thus, depending on the availability of data for a particular biological activity, one may choose the first or the second approach for creating ligand-based computational tools to achieve the best possible results in

  7. Call for Action: Invasive Fungal Infections Associated With Ibrutinib and Other Small Molecule Kinase Inhibitors Targeting Immune Signaling Pathways.

    Science.gov (United States)

    Chamilos, Georgios; Lionakis, Michail S; Kontoyiannis, Dimitrios P

    2018-01-06

    Opportunistic infections caused by Pneumocystis jirovecii, Cryptococcus neoformans, and ubiquitous airborne filamentous fungi have been recently reported in patients with hematological cancers historically considered at low risk for invasive fungal infections (IFIs), after receipt of the Bruton tyrosine kinase inhibitor ibrutinib. The spectrum and severity of IFIs often observed in these patients implies the presence of a complex immunodeficiency that may not be solely attributed to mere inhibition of Bruton tyrosine kinase. In view of the surge in development of small molecule kinase inhibitors for treatment of malignant and autoimmune diseases, it is possible that there would be an emergence of IFIs associated with the effects of these molecules on the immune system. Preclinical assessment of the immunosuppressive effects of kinase inhibitors and human studies aimed at improving patient risk stratification for development of IFIs could lead to prevention, earlier diagnosis, and better outcomes in affected patients. © The Author(s) 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  8. AKAP13 Rho-GEF and PKD-binding domain deficient mice develop normally but have an abnormal response to β-adrenergic-induced cardiac hypertrophy.

    Directory of Open Access Journals (Sweden)

    Matthew J Spindler

    Full Text Available A-kinase anchoring proteins (AKAPs are scaffolding molecules that coordinate and integrate G-protein signaling events to regulate development, physiology, and disease. One family member, AKAP13, encodes for multiple protein isoforms that contain binding sites for protein kinase A (PKA and D (PKD and an active Rho-guanine nucleotide exchange factor (Rho-GEF domain. In mice, AKAP13 is required for development as null embryos die by embryonic day 10.5 with cardiovascular phenotypes. Additionally, the AKAP13 Rho-GEF and PKD-binding domains mediate cardiomyocyte hypertrophy in cell culture. However, the requirements for the Rho-GEF and PKD-binding domains during development and cardiac hypertrophy are unknown.To determine if these AKAP13 protein domains are required for development, we used gene-trap events to create mutant mice that lacked the Rho-GEF and/or the protein kinase D-binding domains. Surprisingly, heterozygous matings produced mutant mice at Mendelian ratios that had normal viability and fertility. The adult mutant mice also had normal cardiac structure and electrocardiograms. To determine the role of these domains during β-adrenergic-induced cardiac hypertrophy, we stressed the mice with isoproterenol. We found that heart size was increased similarly in mice lacking the Rho-GEF and PKD-binding domains and wild-type controls. However, the mutant hearts had abnormal cardiac contractility as measured by fractional shortening and ejection fraction.These results indicate that the Rho-GEF and PKD-binding domains of AKAP13 are not required for mouse development, normal cardiac architecture, or β-adrenergic-induced cardiac hypertrophic remodeling. However, these domains regulate aspects of β-adrenergic-induced cardiac hypertrophy.

  9. Ibrutinib: a first in class covalent inhibitor of Bruton's tyrosine kinase.

    Science.gov (United States)

    Davids, Matthew S; Brown, Jennifer R

    2014-05-01

    Ibrutinib (formerly PCI-32765) is a potent, covalent inhibitor of Bruton's tyrosine kinase, a kinase downstream of the B-cell receptor that is critical for B-cell survival and proliferation. In preclinical studies, ibrutinib bound to Bruton's tyrosine kinase with high affinity, leading to inhibition of B-cell receptor signaling, decreased B-cell activation and induction of apoptosis. In clinical studies, ibrutinib has been well-tolerated and has demonstrated profound anti-tumor activity in a variety of hematologic malignancies, most notably chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), leading to US FDA approval for relapsed CLL and MCL. Ongoing studies are evaluating ibrutinib in other types of non-Hodgkin's lymphoma, such as diffuse large B-cell lymphoma and Waldenström's macrogobulinemia, in larger Phase III studies in CLL and MCL, and in combination studies with monoclonal antibodies and chemotherapy. Future studies will combine ibrutinib with other promising novel agents currently in development in hematologic malignancies.

  10. All-trans-retinoic acid enhances apoptosis induction by tyrosine kinase inhibitors in the eosinophilic leukemia-derived EoL-1 cell line.

    Science.gov (United States)

    Robert, Carine; Apàti, Agota; Chomienne, Christine; Papp, Béla

    2008-02-01

    Imatinib and retinoids induce apoptosis in FIP1L1/PDGFRalpha-positive EoL-1 leukemia cells. Although imatinib induces complete remission in most FIP1L1/PDGFRalpha-positive patients, response to imatinib is sometimes suboptimal. In order to enhance the potency of the molecularly targeted therapy of eosinophilic leukemia, we investigated the effect of retinoids combined with tyrosine kinase inhibitors on EoL-1 cells. We demonstrate that retinoids combined with tyrosine kinase inhibitors lead to enhanced apoptosis induction in EoL-1 cells. Our results suggest that tyrosine kinase inhibitors combined with retinoids may constitute a valuable therapeutic approach for sensitive neoplasias that may display enhanced anti-leukemic potency when compared to single drug treatments.

  11. Effects of tyrosine kinase and phosphatase inhibitors on mitosis progression in synchronized tobacco BY-2 cells.

    Science.gov (United States)

    Sheremet, Ya A; Yemets, A I; Azmi, A; Vissenberg, K; Verbelen, J P; Blume, Ya B

    2012-01-01

    To test whether reversible tubulin phosphorylation plays any role in the process of plant mitosis the effects of inhibitors of tyrosine kinases, herbimycin A, genistein and tyrphostin AG 18, and of an inhibitor of tyrosine phosphatases, sodium orthovanadate, on microtubule organization and mitosis progression in a synchronized BY-2 culture has been investigated. It was found that treatment with inhibitors of tyrosine kinases of BY-2 cells at the G2/M transition did not lead to visible disturbances of mitotic microtubule structures, while it did reduce the frequency of their appearance. We assume that a decreased tyrosine phosphorylation level could alter the microtubule dynamic instability parameters during interphase/prophase transition. All types of tyrosine kinase inhibitors used caused a prophase delay: herbimycin A and genistein for 2 h, and tyrphostin AG18 for 1 h. Thereafter the peak of mitosis was displaced for 1 h by herbimycin A or genistein exposure, but after tyrphostin AG18 treatment the timing of the mitosis-peak was comparable to that in control cells. Enhancement of tyrosine phosphorylation induced by the tyrosine phosphatase inhibitor resulted in the opposite effect on BY-2 mitosis transition. Culture treatment with sodium orthovanadate during 1 h resulted in an accelerated start of the prophase and did not lead to the alteration in time of the mitotic index peak formation, as compared to control cells. We suppose that the reversible tyrosine phosphorylation can be involved in the regulation of interphase to M phase transition possibly through regulation of microtubule dynamics in plant cells.

  12. Akt Inhibitor A-443654 Interferes with Mitotic Progression by Regulating Aurora A Kinase Expression

    Directory of Open Access Journals (Sweden)

    Xuesong Liu

    2008-08-01

    Full Text Available Both Akt and Aurora A kinase have been shown to be important targets for intervention for cancer therapy. We report here that Compound A (A-443654, a specific Akt inhibitor, interferes with mitotic progression and bipolar spindle formation. Compound A induces G2/M accumulation, defects in centrosome separation, and formation of either monopolar arrays or disorganized spindles. On the basis of gene expression array studies, we identified Aurora A as one of the genes regulated transcriptionally by Akt inhibitors including Compound A. Inhibition of the phosphatidylinositol 3-kinase (PI3K/Akt pathway, either by PI3K inhibitor LY294002 or by Compound A, dramatically inhibits the promoter activity of Aurora A, whereas the mammalian target of rapamycin inhibitor has little effect, suggesting that Akt might be responsible for up-regulating Aurora A for mitotic progression. Further analysis of the Aurora A promoter region indicates that the Ets element but not the Sp1 element is required for Compound A-sensitive transcriptional control of Aurora A. Overexpression of Aurora A in cells treated with Compound A attenuates the mitotic arrest and the defects in bipolar spindle formation induced by Akt inhibition. Our studies suggest that that Akt may promote mitotic progression through the transcriptional regulation of Aurora A.

  13. HER2-targeted therapy in breast cancer. Monoclonal antibodies and tyrosine kinase inhibitors

    DEFF Research Database (Denmark)

    Nielsen, Dorte Lisbet; Andersson, Michael; Kamby, Claus

    2008-01-01

    There is strong clinical evidence that trastuzumab, a monoclonal antibody targeting the human epidermal growth factor receptor (HER) two tyrosine kinase receptor, is an important component of first-line treatment of patients with HER2-positive metastatic breast cancer. In particular the combination...... of trastuzumab to chemotherapy improves disease-free and overall survival. The use of lapatinib, a dual tyrosine kinase inhibitor of both HER1 and HER2, in combination with capecitabine in the second-line treatment of HER2-positive patients with metastatic breast cancer previously treated with trastuzumab has...

  14. Optimization of Allosteric With-No-Lysine (WNK) Kinase Inhibitors and Efficacy in Rodent Hypertension Models

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Ken; Levell, Julian; Yoon, Taeyong; Kohls, Darcy; Yowe, David; Rigel, Dean F.; Imase, Hidetomo; Yuan, Jun; Yasoshima, Kayo; DiPetrillo, Keith; Monovich, Lauren; Xu, Lingfei; Zhu, Meicheng; Kato, Mitsunori; Jain, Monish; Idamakanti, Neeraja; Taslimi, Paul; Kawanami, Toshio; Argikar, Upendra A.; Kunjathoor, Vidya; Xie, Xiaoling; Yagi, Yukiko I.; Iwaki, Yuki; Robinson, Zachary; Park, Hyi-Man (Novartis)

    2017-08-03

    The observed structure–activity relationship of three distinct ATP noncompetitive With-No-Lysine (WNK) kinase inhibitor series, together with a crystal structure of a previously disclosed allosteric inhibitor bound to WNK1, led to an overlay hypothesis defining core and side-chain relationships across the different series. This in turn enabled an efficient optimization through scaffold morphing, resulting in compounds with a good balance of selectivity, cellular potency, and pharmacokinetic profile, which were suitable for in vivo proof-of-concept studies. When dosed orally, the optimized compound reduced blood pressure in mice overexpressing human WNK1, and induced diuresis, natriuresis and kaliuresis in spontaneously hypertensive rats (SHR), confirming that this mechanism of inhibition of WNK kinase activity is effective at regulating cardiovascular homeostasis.

  15. In silico design and biological evaluation of a dual specificity kinase inhibitor targeting cell cycle progression and angiogenesis.

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    Antony M Latham

    Full Text Available Protein kinases play a central role in tumor progression, regulating fundamental processes such as angiogenesis, proliferation and metastasis. Such enzymes are an increasingly important class of drug target with small molecule kinase inhibitors being a major focus in drug development. However, balancing drug specificity and efficacy is problematic with off-target effects and toxicity issues.We have utilized a rational in silico-based approach to demonstrate the design and study of a novel compound that acts as a dual inhibitor of vascular endothelial growth factor receptor 2 (VEGFR2 and cyclin-dependent kinase 1 (CDK1. This compound acts by simultaneously inhibiting pro-angiogenic signal transduction and cell cycle progression in primary endothelial cells. JK-31 displays potent in vitro activity against recombinant VEGFR2 and CDK1/cyclin B proteins comparable to previously characterized inhibitors. Dual inhibition of the vascular endothelial growth factor A (VEGF-A-mediated signaling response and CDK1-mediated mitotic entry elicits anti-angiogenic activity both in an endothelial-fibroblast co-culture model and a murine ex vivo model of angiogenesis.We deduce that JK-31 reduces the growth of both human endothelial cells and human breast cancer cells in vitro. This novel synthetic molecule has broad implications for development of similar multi-kinase inhibitors with anti-angiogenic and anti-cancer properties. In silico design is an attractive and innovative method to aid such drug discovery.

  16. A kinase inhibitor screen identifies Mcl-1 and Aurora kinase A as novel treatment targets in antiestrogen-resistant breast cancer cells

    DEFF Research Database (Denmark)

    Thrane, S; Pedersen, A M; Thomsen, M B H

    2015-01-01

    Antiestrogen resistance is a major problem in breast cancer treatment. Therefore, the search for new therapeutic targets and biomarkers for antiestrogen resistance is crucial. In this study, we performed a kinase inhibitor screen on antiestrogen responsive MCF-7 cells and a panel of MCF-7-derived...

  17. Protein kinase inhibitor peptide (PKI): a family of endogenous neuropeptides that modulate neuronal cAMP-dependent protein kinase function.

    Science.gov (United States)

    Dalton, George D; Dewey, William L

    2006-02-01

    Signal transduction cascades involving cAMP-dependent protein kinase are highly conserved among a wide variety of organisms. Given the universal nature of this enzyme it is not surprising that cAMP-dependent protein kinase plays a critical role in numerous cellular processes. This is particularly evident in the nervous system where cAMP-dependent protein kinase is involved in neurotransmitter release, gene transcription, and synaptic plasticity. Protein kinase inhibitor peptide (PKI) is an endogenous thermostable peptide that modulates cAMP-dependent protein kinase function. PKI contains two distinct functional domains within its amino acid sequence that allow it to: (1) potently and specifically inhibit the activity of the free catalytic subunit of cAMP-dependent protein kinase and (2) export the free catalytic subunit of cAMP-dependent protein kinase from the nucleus. Three distinct PKI isoforms (PKIalpha, PKIbeta, PKIgamma) have been identified and each isoform is expressed in the brain. PKI modulates neuronal synaptic activity, while PKI also is involved in morphogenesis and symmetrical left-right axis formation. In addition, PKI also plays a role in regulating gene expression induced by cAMP-dependent protein kinase. Future studies should identify novel physiological functions for endogenous PKI both in the nervous system and throughout the body. Most interesting will be the determination whether functional differences exist between individual PKI isoforms which is an intriguing possibility since these isoforms exhibit: (1) cell-type specific tissue expression patterns, (2) different potencies for the inhibition of cAMP-dependent protein kinase activity, and (3) expression patterns that are hormonally, developmentally and cell-cycle regulated. Finally, synthetic peptide analogs of endogenous PKI will continue to be invaluable tools that are used to elucidate the role of cAMP-dependent protein kinase in a variety of cellular processes throughout the nervous

  18. Vascular endothelial growth factor C promotes cervical cancer metastasis via up-regulation and activation of RhoA/ROCK-2/moesin cascade

    International Nuclear Information System (INIS)

    He, Mian; Cheng, Yang; Li, Wen; Liu, Qiongshan; Liu, Junxiu; Huang, Jinghe; Fu, Xiaodong

    2010-01-01

    The elevated expression of vascular endothelial growth factor C (VEGF-C) is correlated with clinical cervical cancer metastasis and patient survival, which is interpreted by VEGF-C functions to stimulate angiogenesis and lymphatic genesis. However, the direct impact of VEGF-C on cervical cancer cell motility remains largely unknown. In this study, we investigated the effects of VEGF-C on actin cytoskeleton remodeling and on cervical cancer cell migration and invasion and how the actin-regulatory protein, moesin regulated these effects through RhoA/ROCK-2 signaling pathway. On cervical carcinoma cell line SiHa cells, exposure of VEGF-C triggered remodeling of the actin cytoskeleton and the formation of membrane ruffles, which was required for cell movement. VEGF-C significantly enhanced SiHa cells horizontal migration and three-dimensional invasion into matrices. These actions were dependent on increased expression and phosphorylation of the actin-regulatory protein moesin and specific moesin siRNA severely impaired VEGF-C stimulated-cell migration. The extracellular small GTPase RhoA/ROCK-2 cascade mediated the increased moesin expression and phosphorylation, which was discovered by the use of Y-27632, a specific inhibitor of Rho kinase and by transfected constitutively active, dominant-negative RhoA as well as ROCK-2 SiRNA. Furthermore, in the surgical cervical specimen from the patients with FIGO stage at cervical intra-epithelial neoplasia and I-II cervical squamous cell carcinoma, the expression levels of moesin were found to be significantly correlated with tumor malignancy and metastasis. These results implied that VEGF-C promoted cervical cancer metastasis by upregulation and activation of moesin protein through RhoA/ROCK-2 pathway. Our findings offer new insight into the role of VEGF-C on cervical cancer progression and may provide potential targets for cervical cancer therapy

  19. Vascular endothelial growth factor C promotes cervical cancer metastasis via up-regulation and activation of RhoA/ROCK-2/moesin cascade

    Directory of Open Access Journals (Sweden)

    Huang Jinghe

    2010-04-01

    Full Text Available Abstract Background The elevated expression of vascular endothelial growth factor C (VEGF-C is correlated with clinical cervical cancer metastasis and patient survival, which is interpreted by VEGF-C functions to stimulate angiogenesis and lymphatic genesis. However, the direct impact of VEGF-C on cervical cancer cell motility remains largely unknown. Methods In this study, we investigated the effects of VEGF-C on actin cytoskeleton remodeling and on cervical cancer cell migration and invasion and how the actin-regulatory protein, moesin regulated these effects through RhoA/ROCK-2 signaling pathway. Results On cervical carcinoma cell line SiHa cells, exposure of VEGF-C triggered remodeling of the actin cytoskeleton and the formation of membrane ruffles, which was required for cell movement. VEGF-C significantly enhanced SiHa cells horizontal migration and three-dimensional invasion into matrices. These actions were dependent on increased expression and phosphorylation of the actin-regulatory protein moesin and specific moesin siRNA severely impaired VEGF-C stimulated-cell migration. The extracellular small GTPase RhoA/ROCK-2 cascade mediated the increased moesin expression and phosphorylation, which was discovered by the use of Y-27632, a specific inhibitor of Rho kinase and by transfected constitutively active, dominant-negative RhoA as well as ROCK-2 SiRNA. Furthermore, in the surgical cervical specimen from the patients with FIGO stage at cervical intra-epithelial neoplasia and I-II cervical squamous cell carcinoma, the expression levels of moesin were found to be significantly correlated with tumor malignancy and metastasis. Conclusions These results implied that VEGF-C promoted cervical cancer metastasis by upregulation and activation of moesin protein through RhoA/ROCK-2 pathway. Our findings offer new insight into the role of VEGF-C on cervical cancer progression and may provide potential targets for cervical cancer therapy.

  20. Rho-associated coiled-coil kinase (ROCK) protein controls microtubule dynamics in a novel signaling pathway that regulates cell migration.

    Science.gov (United States)

    Schofield, Alice V; Steel, Rohan; Bernard, Ora

    2012-12-21

    The two members of the Rho-associated coiled-coil kinase (ROCK1 and 2) family are established regulators of actin dynamics that are involved in the regulation of the cell cycle as well as cell motility and invasion. Here, we discovered a novel signaling pathway whereby ROCK regulates microtubule (MT) acetylation via phosphorylation of the tubulin polymerization promoting protein 1 (TPPP1/p25). We show that ROCK phosphorylation of TPPP1 inhibits the interaction between TPPP1 and histone deacetylase 6 (HDAC6), which in turn results in increased HDAC6 activity followed by a decrease in MT acetylation. As a consequence, we show that TPPP1 phosphorylation by ROCK increases cell migration and invasion via modulation of cellular acetyl MT levels. We establish here that the ROCK-TPPP1-HDAC6 signaling pathway is important for the regulation of cell migration and invasion.

  1. Cyclic AMP (cAMP)-mediated stimulation of adipocyte differentiation requires the synergistic action of Epac- and cAMP-dependent protein kinase-dependent processes

    DEFF Research Database (Denmark)

    Petersen, Rasmus Koefoed; Madsen, Lise; Pedersen, Lone Møller

    2008-01-01

    AMP-dependent stimulation of adipocyte differentiation. Epac, working via Rap, acted synergistically with cAMP-dependent protein kinase (protein kinase A [PKA]) to promote adipogenesis. The major role of PKA was to down-regulate Rho and Rho-kinase activity, rather than to enhance CREB phosphorylation. Suppression of Rho......-kinase impaired proadipogenic insulin/insulin-like growth factor 1 signaling, which was restored by activation of Epac. This interplay between PKA and Epac-mediated processes not only provides novel insight into the initiation and tuning of adipocyte differentiation, but also demonstrates a new mechanism of c......AMP signaling whereby cAMP uses both PKA and Epac to achieve an appropriate cellular response....

  2. MicroRNA-124 (MiR-124 Inhibits Cell Proliferation, Metastasis and Invasion in Colorectal Cancer by Downregulating Rho-Associated Protein Kinase 1(ROCK1

    Directory of Open Access Journals (Sweden)

    Liqing Zhou

    2016-05-01

    Full Text Available Background/Aims: MiR-124 inhibits neoplastic transformation, cell proliferation, and metastasis and downregulates Rho-associated protein kinase (ROCK1 in Colorectal Cancer (CRC. The aim of this study was to further investigate the roles and interactions of ROCK1 and miR-124 and the effects of knockdown of ROCK1and MiR-124 in human Colorectal Cancer (CRC. Methods: Three Colorectal cancer cell lines (HCT116, HT29 and SW620 and one Human Colonic Mucosa Epithelial cell line (NCM460 were studied. The protein expression of ROCK1 was examined by Western-blot and qRT-PCR were performed to examine the expression levels of ROCK1 mRNA and miR-124. Furthermore, We performed transfection of cancer cell line (SW620 with pre-miR-124(mimics, anti-miR-124(inhibitor, ROCK1 siRNA and the control, then observed the affects of ROCK1 protein expression by westen-blot, cell proliferation by EDU (5-ethynyl-2'deoxyuridine assay and expression levels of ROCK1mRNA by qRT-PCR . A soft agar formation assay, Migration and invasion assays were used to determine the effect of regulation of miR-124 and ROCK1, and survivin on the transformation and invasion capability of colorectal cancer cell. Results: MiR-124 expression was significantly downregulated in CRC cell lines compare to normal (P 0.05. ROCK1 mRNA was unaltered in cells transfected with miR-124 mimic and miR-124 inhibitor, compared to normal controls. There was a significant reduction in ROCK1 protein in cells transfected with miR-124 mimic and a significant increase in cells transfected with miR-124 inhibitor (P Conclusions: In conclusion, our results demonstrated that miR-124 not only promoted cancer cell hyperplasia and significantly associated with CRC metastasis and progression, but also downregulated ROCK1 protein expression. More importantly, increased ROCK1 expression or inhibited miR-124 expression may constitute effective new therapeutic strategies for the treatment of renal cancer in the future.

  3. Ret function in muscle stem cells points to tyrosine kinase inhibitor therapy for facioscapulohumeral muscular dystrophy.

    Science.gov (United States)

    Moyle, Louise A; Blanc, Eric; Jaka, Oihane; Prueller, Johanna; Banerji, Christopher Rs; Tedesco, Francesco Saverio; Harridge, Stephen Dr; Knight, Robert D; Zammit, Peter S

    2016-11-14

    Facioscapulohumeral muscular dystrophy (FSHD) involves sporadic expression of DUX4, which inhibits myogenesis and is pro-apoptotic. To identify target genes, we over-expressed DUX4 in myoblasts and found that the receptor tyrosine kinase Ret was significantly up-regulated, suggesting a role in FSHD. RET is dynamically expressed during myogenic progression in mouse and human myoblasts. Constitutive expression of either RET9 or RET51 increased myoblast proliferation, whereas siRNA-mediated knockdown of Ret induced myogenic differentiation. Suppressing RET activity using Sunitinib, a clinically-approved tyrosine kinase inhibitor, rescued differentiation in both DUX4-expressing murine myoblasts and in FSHD patient-derived myoblasts. Importantly, Sunitinib also increased engraftment and differentiation of FSHD myoblasts in regenerating mouse muscle. Thus, DUX4-mediated activation of Ret prevents myogenic differentiation and could contribute to FSHD pathology by preventing satellite cell-mediated repair. Rescue of DUX4-induced pathology by Sunitinib highlights the therapeutic potential of tyrosine kinase inhibitors for treatment of FSHD.

  4. The selective Aurora B kinase inhibitor AZD1152 is a potential new treatment for multiple myeloma.

    Science.gov (United States)

    Evans, Robert P; Naber, Claudia; Steffler, Tara; Checkland, Tamara; Maxwell, Christopher A; Keats, Jonathan J; Belch, Andrew R; Pilarski, Linda M; Lai, Raymond; Reiman, Tony

    2008-02-01

    Aurora kinases are potential targets for cancer therapy. Previous studies have validated Aurora kinase A as a therapeutic target in multiple myeloma (MM), and have demonstrated in vitro anti-myeloma effects of small molecule Aurora kinase inhibitors that inhibit both Aurora A and B. This study demonstrated that Aurora B kinase was strongly expressed in myeloma cell lines and primary plasma cells. The selective Aurora B inhibitor AZD1152-induced apoptotic death in myeloma cell lines at nanomolar concentrations, with a cell cycle phenotype consistent with that reported previously for Aurora B inhibition. In some cases, AZD1152 in combination with dexamethasone showed increased anti-myeloma activity compared with the use of either agent alone. AZD1152 was active against sorted CD138(+) BM plasma cells from myeloma patients but also, as expected, was toxic to CD138(-) marrow cells from the same patients. In a murine myeloma xenograft model, AZD1152-inhibited tumour growth at well-tolerated doses and induced cell death in established tumours, with associated mild, transient leucopenia. AZD1152 shows promise in these preclinical studies as a novel treatment for MM.

  5. Identification of critical chemical features for Aurora kinase-B inhibitors using Hip-Hop, virtual screening and molecular docking

    Science.gov (United States)

    Sakkiah, Sugunadevi; Thangapandian, Sundarapandian; John, Shalini; Lee, Keun Woo

    2011-01-01

    This study was performed to find the selective chemical features for Aurora kinase-B inhibitors using the potent methods like Hip-Hop, virtual screening, homology modeling, molecular dynamics and docking. The best hypothesis, Hypo1 was validated toward a wide range of test set containing the selective inhibitors of Aurora kinase-B. Homology modeling and molecular dynamics studies were carried out to perform the molecular docking studies. The best hypothesis Hypo1 was used as a 3D query to screen the chemical databases. The screened molecules from the databases were sorted based on ADME and drug like properties. The selective hit compounds were docked and the hydrogen bond interactions with the critical amino acids present in Aurora kinase-B were compared with the chemical features present in the Hypo1. Finally, we suggest that the chemical features present in the Hypo1 are vital for a molecule to inhibit the Aurora kinase-B activity.

  6. A Comparative Study of the Aneugenic and Polyploidy-inducing Effects of Fisetin and Two Model Aurora Kinase Inhibitors

    Science.gov (United States)

    Gollapudi, P.; Hasegawa, L.S.; Eastmond, D.A.

    2014-01-01

    Fisetin, a plant flavonol commonly found in fruits, nuts and vegetables, is frequently added to nutritional supplements due to its reported cardioprotective, anti-carcinogenic and antioxidant properties. Earlier reports from our laboratory and others have indicated that fisetin has both aneugenic and clastogenic properties in cultured cells. More recently, fisetin has also been reported to target Aurora B kinase, a Ser/Thr kinase involved in ensuring proper microtubule attachment at the spindle assembly checkpoint, and an enzyme that is overexpressed in several types of cancer. Here we have further characterized the chromosome damage caused by fisetin and compared it with that induced by two known Aurora kinase inhibitors, VX-680 and ZM-447439, in cultured TK6 cells using the micronucleus assay with CREST staining as well as a flow cytometry-based assay that measures multiple types of numerical chromosomal aberrations. The three compounds were highly effective in inducing aneuploidy and polyploidy as evidenced by increases in kinetochore-positive micronuclei, hyperdiploidy, and polyploidy. With fisetin, however, the latter two effects were most significantly observed only after cells were allowed to overcome a cell cycle delay, and occurred at higher concentrations than those induced by the other Aurora kinase inhibitors. Modest increases in kinetochore-negative micronuclei were also seen with the model Aurora kinase inhibitors. These results indicate that fisetin induces multiple types of chromosome abnormalities in human cells, and indicate a need for a thorough investigation of fisetin-augmented dietary supplements. PMID:24680981

  7. Rho kinase activity controls directional cell movements during primitive streak formation in the rabbit embryo.

    Science.gov (United States)

    Stankova, Viktoria; Tsikolia, Nikoloz; Viebahn, Christoph

    2015-01-01

    During animal gastrulation, the specification of the embryonic axes is accompanied by epithelio-mesenchymal transition (EMT), the first major change in cell shape after fertilization. EMT takes place in disparate topographical arrangements, such as the circular blastopore of amphibians, the straight primitive streak of birds and mammals or in intermediate gastrulation forms of other amniotes such as reptiles. Planar cell movements are prime candidates to arrange specific modes of gastrulation but there is no consensus view on their role in different vertebrate classes. Here, we test the impact of interfering with Rho kinase-mediated cell movements on gastrulation topography in blastocysts of the rabbit, which has a flat embryonic disc typical for most mammals. Time-lapse video microscopy, electron microscopy, gene expression and morphometric analyses of the effect of inhibiting ROCK activity showed - besides normal specification of the organizer region - a dose-dependent disruption of primitive streak formation; this disruption resulted in circular, arc-shaped or intermediate forms, reminiscent of those found in amphibians, fishes and reptiles. Our results reveal a crucial role of ROCK-controlled directional cell movements during rabbit primitive streak formation and highlight the possibility that temporal and spatial modulation of cell movements were instrumental for the evolution of gastrulation forms. © 2015. Published by The Company of Biologists Ltd.

  8. RhoA GTPase regulates radiation-induced alterations in endothelial cell adhesion and migration

    International Nuclear Information System (INIS)

    Rousseau, Matthieu; Gaugler, Marie-Hélène; Rodallec, Audrey; Bonnaud, Stéphanie; Paris, François; Corre, Isabelle

    2011-01-01

    Highlights: ► We explore the role of RhoA in endothelial cell response to ionizing radiation. ► RhoA is rapidly activated by single high-dose of radiation. ► Radiation leads to RhoA/ROCK-dependent actin cytoskeleton remodeling. ► Radiation-induced apoptosis does not require the RhoA/ROCK pathway. ► Radiation-induced alteration of endothelial adhesion and migration requires RhoA/ROCK. -- Abstract: Endothelial cells of the microvasculature are major target of ionizing radiation, responsible of the radiation-induced vascular early dysfunctions. Molecular signaling pathways involved in endothelial responses to ionizing radiation, despite being increasingly investigated, still need precise characterization. Small GTPase RhoA and its effector ROCK are crucial signaling molecules involved in many endothelial cellular functions. Recent studies identified implication of RhoA/ROCK in radiation-induced increase in endothelial permeability but other endothelial functions altered by radiation might also require RhoA proteins. Human microvascular endothelial cells HMEC-1, either treated with Y-27632 (inhibitor of ROCK) or invalidated for RhoA by RNA interference were exposed to 15 Gy. We showed a rapid radiation-induced activation of RhoA, leading to a deep reorganisation of actin cytoskeleton with rapid formation of stress fibers. Endothelial early apoptosis induced by ionizing radiation was not affected by Y-27632 pre-treatment or RhoA depletion. Endothelial adhesion to fibronectin and formation of focal adhesions increased in response to radiation in a RhoA/ROCK-dependent manner. Consistent with its pro-adhesive role, ionizing radiation also decreased endothelial cells migration and RhoA was required for this inhibition. These results highlight the role of RhoA GTPase in ionizing radiation-induced deregulation of essential endothelial functions linked to actin cytoskeleton.

  9. 1α,25-Dihydroxyvitamin D3 Ameliorates Seawater Aspiration-Induced Lung Injury By Inhibiting The Translocation Of NF-κB and RhoA.

    Science.gov (United States)

    Zhang, Minlong; Jin, Faguang

    2017-06-01

    Our previous study have reported that 1α,25-Dihydroxyvitamin D3 (calcitriol) suppresses seawater aspiration-induced ALI in vitro and in vivo. We also have confirmed that treatment with calcitriol ameliorates seawater aspiration-induced inflammation and pulmonary edema via the inhibition of NF-κB and RhoA/Rho kinase pathway activation. In our further work, we investigated the effect of calcitriol on nuclear translocation of NF-κB and membrane translocation of RhoA in vitro. A549 cells and rat pulmonary microvascular endothelial cells (RPMVECs) were cultured with calcitriol or not for 48 h and then stimulated with 25% seawater for 40 min. After these treatments, cells were collected and performed with immunofluorescent staining to observe the translocation of NF-κB and RhoA and the cytoskeleton remodeling. In vitro, seawater stimulation activates nuclear translocation of NF-κB and membrane translocation of RhoA in A549 cells. In addition, seawater administration also induced cytoskeleton remodeling in A549 cells and RPMVECs. However, pretreatment with calcitriol significantly inhibited the activation of NF-κB and RhoA/Rho kinase pathways, as demonstrated by the reduced nuclear translocation of NF-κB and membrane translocation of RhoA in A549 cells. Meanwhile, treatment of calcitriol also regulated the cytoskeleton remodeling in both A549 cells and RPMVECs. These results demonstrated that treatment with calcitriol ameliorates seawater aspiration-induced ALI via inhibition of nuclear translocation of NF-κB and membrane translocation of RhoA and protection of alveolar epithelial and pulmonary microvascular endothelial barrier.

  10. 2-Aminopyridine-Based Mitogen-Activated Protein Kinase Kinase Kinase Kinase 4 (MAP4K4) Inhibitors: Assessment of Mechanism-Based Safety.

    Science.gov (United States)

    Dow, Robert L; Ammirati, Mark; Bagley, Scott W; Bhattacharya, Samit K; Buckbinder, Leonard; Cortes, Christian; El-Kattan, Ayman F; Ford, Kristen; Freeman, Gary B; Guimarães, Cristiano R W; Liu, Shenping; Niosi, Mark; Skoura, Athanasia; Tess, David

    2018-04-12

    Studies have linked the serine-threonine kinase MAP4K4 to the regulation of a number of biological processes and/or diseases, including diabetes, cancer, inflammation, and angiogenesis. With a majority of the members of our lead series (e.g., 1) suffering from time-dependent inhibition (TDI) of CYP3A4, we sought design avenues that would eliminate this risk. One such approach arose from the observation that carboxylic acid-based intermediates employed in our discovery efforts retained high MAP4K4 inhibitory potency and were devoid of the TDI risk. The medicinal chemistry effort that led to the discovery of this central nervous system-impaired inhibitor together with its preclinical safety profile is described.

  11. Automated NMR fragment based screening identified a novel interface blocker to the LARG/RhoA complex.

    Directory of Open Access Journals (Sweden)

    Jia Gao

    Full Text Available The small GTPase cycles between the inactive GDP form and the activated GTP form, catalyzed by the upstream guanine exchange factors. The modulation of such process by small molecules has been proven to be a fruitful route for therapeutic intervention to prevent the over-activation of the small GTPase. The fragment based approach emerging in the past decade has demonstrated its paramount potential in the discovery of inhibitors targeting such novel and challenging protein-protein interactions. The details regarding the procedure of NMR fragment screening from scratch have been rarely disclosed comprehensively, thus restricts its wider applications. To achieve a consistent screening applicable to a number of targets, we developed a highly automated protocol to cover every aspect of NMR fragment screening as possible, including the construction of small but diverse libray, determination of the aqueous solubility by NMR, grouping compounds with mutual dispersity to a cocktail, and the automated processing and visualization of the ligand based screening spectra. We exemplified our streamlined screening in RhoA alone and the complex of the small GTPase RhoA and its upstream guanine exchange factor LARG. Two hits were confirmed from the primary screening in cocktail and secondary screening over individual hits for LARG/RhoA complex, while one of them was also identified from the screening for RhoA alone. HSQC titration of the two hits over RhoA and LARG alone, respectively, identified one compound binding to RhoA.GDP at a 0.11 mM affinity, and perturbed the residues at the switch II region of RhoA. This hit blocked the formation of the LARG/RhoA complex, validated by the native gel electrophoresis, and the titration of RhoA to ¹⁵N labeled LARG in the absence and presence the compound, respectively. It therefore provides us a starting point toward a more potent inhibitor to RhoA activation catalyzed by LARG.

  12. 1-Methoxy-agroclavine from Penicillium sp. WC75209, a novel inhibitor of the Lck tyrosine kinase.

    Science.gov (United States)

    Padmanabha, R; Shu, Y Z; Cook, L S; Veitch, J A; Donovan, M; Lowe, S; Huang, S; Pirnik, D; Manly, S P

    1998-03-17

    A high-throughput screen was developed and implemented to identify inhibitors of the Lck tyrosine kinase. This report describes the identification of a specific inhibitor of this enzyme from the solid fermentation culture of the Penicillium sp., WC75209. The active compound was isolated and structurally characterized as 1-methoxy-5R, 10S-agroclavine, a new member of the ergot alkaloid family.

  13. Animal model for angiotensin II effects in the internal anal sphincter smooth muscle: mechanism of action.

    Science.gov (United States)

    Fan, Ya-Ping; Puri, Rajinder N; Rattan, Satish

    2002-03-01

    Effect of ANG II was investigated in in vitro smooth muscle strips and in isolated smooth muscle cells (SMC). Among different species, rat internal and sphincter (IAS) smooth muscle showed significant and reproducible contraction that remained unmodified by different neurohumoral inhibitors. The AT(1) antagonist losartan but not AT(2) antagonist PD-123319 antagonized ANG II-induced contraction of the IAS smooth muscle and SMC. ANG II-induced contraction of rat IAS smooth muscle and SMC was attenuated by tyrosine kinase inhibitors genistein and tyrphostin, protein kinase C (PKC) inhibitor H-7, Ca(2+) channel blocker nicardipine, Rho kinase inhibitor Y-27632 or p(44/42) mitogen-activating protein kinase (MAPK(44/42)) inhibitor PD-98059. Combinations of nicardipine and H-7, Y-27632, and PD-98059 caused further attenuation of the ANG II effects. Western blot analyses revealed the presence of both AT(1) and AT(2) receptors. We conclude that ANG II causes contraction of rat IAS smooth muscle by the activation of AT(1) receptors at the SMC and involves multiple intracellular pathways, influx of Ca(2+), and activation of PKC, Rho kinase, and MAPK(44/42).

  14. The Rho-GTPase effector ROCK regulates meiotic maturation of the bovine oocyte via myosin light chain phosphorylation and cofilin phosphorylation.

    Science.gov (United States)

    Lee, So-Rim; Xu, Yong-Nan; Jo, Yu-Jin; Namgoong, Suk; Kim, Nam-Hyung

    2015-11-01

    Oocyte meiosis involves a unique asymmetric division involving spindle movement from the central cytoplasm to the cortex, followed by polar body extrusion. ROCK is a Rho-GTPase effector involved in various cellular functions in somatic cells as well as oocyte meiosis. ROCK was previously shown to promote actin organization by phosphorylating several downstream targets, including LIM domain kinase (LIMK), phosphorylated cofilin (p-cofilin), and myosin light chain (MLC). In this study, we investigated the roles of ROCK and MLC during bovine oocyte meiosis. We found that ROCK was localized around the nucleus at the oocyte's germinal-vesicle (GV) stage, but spreads to the rest of the cytoplasm in later developmental stages. On the other hand, phosphorylated MLC (p-MLC) localized at the cortex, and its abundance decreased by the metaphase-II stage. Disrupting ROCK activity, via RNAi or the chemical inhibitor Y-27632, blocked both cell cycle progression and polar body extrusion. ROCK inhibition also resulted in decreased cortical actin, p-cofilin, and p-MLC levels. Similar to the phenotype associated with inhibition of ROCK activity, inhibition of MLC kinase by the chemical inhibitor ML-7 caused defects in polar body extrusion. Collectively, our results suggest that the ROCK/MLC/actomyosin as well as ROCK/LIMK/cofilin pathways regulate meiotic spindle migration and cytokinesis during bovine oocyte maturation. © 2015 Wiley Periodicals, Inc.

  15. Cancer Cell Resistance to Aurora Kinase Inhibitors: Identification of Novel Targets for Cancer Therapy

    Czech Academy of Sciences Publication Activity Database

    Hrabáková, Rita; Kollaredy, M.; Tylečková, Jiřina; Halada, Petr; Hajdúch, M.; Gadher, S. J.; Kovářová, Hana

    2013-01-01

    Roč. 12, č. 1 (2013), s. 455-469 ISSN 1535-3893 R&D Projects: GA MŠk LC07017 Institutional support: RVO:67985904 ; RVO:61388971 Keywords : Aurora kinase inhibitors * resistance * p53 * apoptosis Subject RIV: CE - Biochemistry Impact factor: 5.001, year: 2013

  16. RhoA signaling modulates cyclin D1 expression in human lung fibroblasts; implications for idiopathic pulmonary fibrosis

    Directory of Open Access Journals (Sweden)

    Hoban PR

    2006-06-01

    Full Text Available Abstract Background Idiopathic Pulmonary Fibrosis (IPF is a debilitating disease characterized by exaggerated extracellular matrix deposition and aggressive lung structural remodeling. Disease pathogenesis is driven by fibroblastic foci formation, consequent on growth factor overexpression and myofibroblast proliferation. We have previously shown that both CTGF overexpression and myofibroblast formation in IPF cell lines are dependent on RhoA signaling. As RhoA-mediated regulation is also involved in cell cycle progression, we hypothesise that this pathway is key to lung fibroblast turnover through modulation of cyclin D1 kinetic expression. Methods Cyclin D1 expression was compared in primary IPF patient-derived fibroblasts and equivalent normal control cells. Quantitative real time PCR was employed to examine relative expression levels of cyclin D1 mRNA; protein expression was confirmed by western blotting. Effects of Rho signaling were investigated using transient transfection of constitutively active and dominant negative RhoA constructs as well as pharmacological inhibitors. Cellular proliferation of lung fibroblasts was determined by BrdU incorporation ELISA. To further explore RhoA regulation of cyclin D1 in lung fibroblasts and associated cell cycle progression, an established Rho inhibitor, Simvastatin, was incorporated in our studies. Results Cyclin D1 expression was upregulated in IPF compared to normal lung fibroblasts under exponential growth conditions (p Conclusion These findings report for the first time that cyclin D1 expression is deregulated in IPF through a RhoA dependent mechanism that influences lung fibroblast proliferation. This potentially unravels new molecular targets for future anti-IPF strategies; accordingly, Simvastatin inhibition of Rho-mediated cyclin D1 expression in IPF fibroblasts merits further exploitation.

  17. NMR characterization of weak interactions between RhoGDI2 and fragment screening hits.

    Science.gov (United States)

    Liu, Jiuyang; Gao, Jia; Li, Fudong; Ma, Rongsheng; Wei, Qingtao; Wang, Aidong; Wu, Jihui; Ruan, Ke

    2017-01-01

    The delineation of intrinsically weak interactions between novel targets and fragment screening hits has long limited the pace of hit-to-lead evolution. Rho guanine-nucleotide dissociation inhibitor 2 (RhoGDI2) is a novel target that lacks any chemical probes for the treatment of tumor metastasis. Protein-observed and ligand-observed NMR spectroscopy was used to characterize the weak interactions between RhoGDI2 and fragment screening hits. We identified three hits of RhoGDI2 using streamlined NMR fragment-based screening. The binding site residues were assigned using non-uniformly sampled C α - and H α -based three dimensional NMR spectra. The molecular docking to the proposed geranylgeranyl binding pocket of RhoGDI2 was guided by NMR restraints of chemical shift perturbations and ligand-observed transferred paramagnetic relaxation enhancement. We further validated the weak RhoGDI2-hit interactions using mutagenesis and structure-affinity analysis. Weak interactions between RhoGDI2 and fragment screening hits were delineated using an integrated NMR approach. Binders to RhoGDI2 as a potential anti-cancer target have been first reported, and their weak interactions were depicted using NMR spectroscopy. Our work highlights the powerfulness and the versatility of the integrative NMR techniques to provide valuable structural insight into the intrinsically weak interactions between RhoGDI2 and the fragment screening hits, which could hardly be conceived using other biochemical techniques. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. LONG-TERM RESULTS OF TARGET THERAPY WITH FIRST AND * SECOND-LINE TYROSINE KINASE INHIBITORS IN PATIENTS WITH CHRONIC MYELOID LEUKEMIA

    Directory of Open Access Journals (Sweden)

    L. L. Vysotskaya

    2015-01-01

    Full Text Available Aim: To assess long-term efficacy of firstand second-line tyrosine kinase inhibitors in non-selected patients with chronic myeloid leukemia in a real-life clinical setting.Materials and methods: The assessment is based on long-term results of a prospective single center comparative clinical trial that was based on non-selected groups of 116 patients with various stages of chronic myeloid leukemia being treated with a first generation tyrosine kinase inhibitor imatinib, and of 44 patients being treated with a second generation tyrosine kinase inhibitor nilotinib. We analyzed all-cause mortality, progression-free survival from April 2005 to April 2013, with a median of the follow-up of 128 months.Results: In 116 patients with chronic myeloid leukemia treated with imatinib, the Kaplan-Meier survival estimate was 120 months. In 44 patients at an early chronic phase, 5-year overall survival and progression-free survival was 93.2% and 8-year overall and progression-free survival was 79.5%. In 44 patients at a late chronic stage, 5-year overall and progression-free survival was 95.5%, 8-year overall and progression-free survival, 72.7%. In 28 patients at acceleration phase, 5-years overall survival was 78.6% and 8-year overall survival, 46%. Median of overall survival in patients treated with nilotinib was not reached. During 78.6 months of combination treatment with cytotoxic agents, tyrosine kinase inhibitors of the first (imatinib and second line (nilotinib, overall survival was 100%.Conclusion: In clinical practice, inclusion of patients with chronic myeloid leukemia and imatinib resistance (disease relapse or imatinib intolerance into the treatment program with frontline therapy with general cytotoxic agents and thereafter with firstand second-line tyrosine kinase inhibitors significantly improves overall survival.

  19. Ibrutinib: a first in class covalent inhibitor of Bruton’s tyrosine kinase

    Science.gov (United States)

    Davids, Matthew S; Brown, Jennifer R

    2015-01-01

    Ibrutinib (formerly PCI-32765) is a potent, covalent inhibitor of Bruton’s tyrosine kinase, a kinase downstream of the B-cell receptor that is critical for B-cell survival and proliferation. In preclinical studies, ibrutinib bound to Bruton’s tyrosine kinase with high affinity, leading to inhibition of B-cell receptor signaling, decreased B-cell activation and induction of apoptosis. In clinical studies, ibrutinib has been well-tolerated and has demonstrated profound anti-tumor activity in a variety of hematologic malignancies, most notably chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), leading to US FDA approval for relapsed CLL and MCL. Ongoing studies are evaluating ibrutinib in other types of non-Hodgkin’s lymphoma, such as diffuse large B-cell lymphoma and Waldenström’s macrogobulinemia, in larger Phase III studies in CLL and MCL, and in combination studies with monoclonal antibodies and chemotherapy. Future studies will combine ibrutinib with other promising novel agents currently in development in hematologic malignancies. PMID:24941982

  20. Multi-tyrosine kinase inhibitors in preclinical studies for pediatric CNS AT/RT: Evidence for synergy with Topoisomerase-I inhibition

    Directory of Open Access Journals (Sweden)

    Jayanthan Aarthi

    2011-12-01

    Full Text Available Abstract Background Currently, Atypical Teratoid Rhabdoid Tumor (AT/RT constitutes one of the most difficult to treat malignancies in pediatrics. Hence, new knowledge of potential targets for therapeutics and the development of novel treatment approaches are urgently needed. We have evaluated the presence of cytokine pathways and the effects of two clinically available multi-tyrosine kinase inhibitors for cytotoxicity, target modulation and drug combinability against AT/RT cell lines. Results AT/RT cell lines expressed measurable quantities of VEGF, FGF, PDGF and SDF-1, although the absolute amounts varied between the cell lines. The targeted receptor tyrosine kinase inhibitor sorafenib inhibited the key signaling molecule Erk, which was activated following the addition of own conditioned media, suggesting the existence of autocrine/paracrine growth stimulatory pathways. The multi-tyrosine kinase inhibitors sorafenib and sunitinib also showed significant growth inhibition of AT/RT cells and their activity was enhanced by combination with the topoisomerase inhibitor, irinotecan. The loss of cytoplasmic NF-kappa-B in response to irinotecan was diminished by sorafenib, providing evidence for a possible benefit for this drug combination. Conclusions In addition to previously described involvement of insulin like growth factor (IGF family of cytokines, a multitude of other growth factors may contribute to the growth and survival of AT/RT cells. However, consistent with the heterogeneous nature of this tumor, quantitative and qualitative differences may exist among different tumor samples. Multi-tyrosine kinase inhibitors appear to have effective antitumor activity against all cell lines studied. In addition, the target modulation studies and drug combinability data provide the groundwork for additional studies and support the evaluation of these agents in future treatment protocols.

  1. Navigating into the binding pockets of the HER family protein kinases: discovery of novel EGFR inhibitor as antitumor agent.

    Science.gov (United States)

    Liu, Wei; Ning, Jin-Feng; Meng, Qing-Wei; Hu, Jing; Zhao, Yan-Bin; Liu, Chao; Cai, Li

    2015-01-01

    The epidermal growth factor receptor (EGFR) family has been validated as a successful antitumor drug target for decades. Known EGFR inhibitors were exposed to distinct drug resistance against the various EGFR mutants within non-small-cell lung cancer (NSCLC), particularly the T790M mutation. Although so far a number of studies have been reported on the development of third-generation EGFR inhibitors for overcoming the resistance issue, the design procedure largely depends on the intuition of medicinal chemists. Here we retrospectively make a detailed analysis of the 42 EGFR family protein crystal complexes deposited in the Protein Data Bank (PDB). Based on the analysis of inhibitor binding modes in the kinase catalytic cleft, we identified a potent EGFR inhibitor (compound A-10) against drug-resistant EGFR through fragment-based drug design. This compound showed at least 30-fold more potency against EGFR T790M than the two control molecules erlotinib and gefitinib in vitro. Moreover, it could exhibit potent HER2 inhibitory activities as well as tumor growth inhibitory activity. Molecular docking studies revealed a structural basis for the increased potency and mutant selectivity of this compound. Compound A-10 may be selected as a promising candidate in further preclinical studies. In addition, our findings could provide a powerful strategy to identify novel selective kinase inhibitors on the basis of detailed kinase-ligand interaction space in the PDB.

  2. C3 rho-inhibitor for targeted pharmacological manipulation of osteoclast-like cells.

    Directory of Open Access Journals (Sweden)

    Andrea Tautzenberger

    Full Text Available The C3 toxins from Clostridium botulinum (C3bot and Clostridium limosum (C3lim as well as C3-derived fusion proteins are selectively taken up into the cytosol of monocytes/macrophages where the C3-catalyzed ADP-ribosylation of Rho results in inhibition of Rho-signalling and characteristic morphological changes. Since the fusion toxin C2IN-C3lim was efficiently taken up into and inhibited proliferation of murine macrophage-like RAW 264.7 cells, its effects on RAW 264.7-derived osteoclasts were investigated. C2IN-C3lim was taken up into differentiated osteoclasts and decreased their resorption activity. In undifferentiated RAW 264.7 cells, C2IN-C3lim-treatment significantly decreased their differentiation into osteoclasts as determined by counting the multi-nucleated, TRAP-positive cells. This inhibitory effect was concentration- and time-dependent and most efficient when C2IN-C3lim was applied in the early stage of osteoclast-formation. A single-dose application of C2IN-C3lim at day 0 and its subsequent removal at day 1 reduced the number of osteoclasts in a comparable manner while C2IN-C3lim-application at later time points did not reduce the number of osteoclasts to a comparable degree. Control experiments with an enzymatically inactive C3 protein revealed that the ADP-ribosylation of Rho was essential for the observed effects. In conclusion, the results indicate that Rho-activity is crucial during the early phase of osteoclast-differentiation. Other bone cell types such as pre-osteoblastic cells were not affected by C2IN-C3lim. Due to their cell-type selective and specific mode of action, C3 proteins and C3-fusions might be valuable tools for targeted pharmacological manipulation of osteoclast formation and activity, which could lead to development of novel therapeutic strategies against osteoclast-associated diseases.

  3. Design, Synthesis and Evaluation of Ribose-modified Anilinopyrimidine Derivatives as EGFR Tyrosine Kinase Inhibitors

    Science.gov (United States)

    Hu, Xiuqin; Wang, Disha; Tong, Yi; Tong, Linjiang; Wang, Xia; Zhu, Lili; Xie, Hua; Li, Shiliang; Yang, You; Xu, Yufang

    2017-11-01

    The synthesis of a series of ribose-modified anilinopyrimidine derivatives was efficiently achieved by utilizing DBU or tBuOLi-promoted coupling of ribosyl alcohols with 2,4,5-trichloropyrimidine as key step. Preliminary biological evaluation of this type of compounds as new EGFR tyrosine kinase inhibitors for combating EGFR L858R/T790M mutant associated with drug resistance in the treatment of non-small cell lung cancer revealed that 3-N-acryloyl-5-O-anilinopyrimidine ribose derivative 1a possessed potent and specific inhibitory activity against EGFR L858R/T790M over WT EGFR. Based upon molecular docking studies of the binding mode between compound 1a and EGFR, the distance between the Michael receptor and the pyrimidine scaffold is considered as an important factor for the inhibitory potency and future design of selective EGFR tyrosine kinase inhibitors against EGFR L858R/T790M mutants.

  4. A high-throughput screening assay for eukaryotic elongation factor 2 kinase inhibitors

    Directory of Open Access Journals (Sweden)

    Ting Xiao

    2016-10-01

    Full Text Available Eukaryotic elongation factor 2 kinase (eEF2K inhibitors may aid in the development of new therapeutic agents to combat cancer. Purified human eEF2K was obtained from an Escherichia coli expression system and a luminescence-based high-throughput screening (HTS assay was developed using MH-1 peptide as the substrate. The luminescent readouts correlated with the amount of adenosine triphosphate remaining in the kinase reaction. This method was applied to a large-scale screening campaign against a diverse compound library and subsequent confirmation studies. Nine initial hits showing inhibitory activities on eEF2K were identified from 56,000 synthetic compounds during the HTS campaign, of which, five were chosen to test their effects in cancer cell lines.

  5. Activity of the novel BCR kinase inhibitor IQS019 in preclinical models of B-cell non-Hodgkin lymphoma

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    P. Balsas

    2017-03-01

    Full Text Available Abstract Background Pharmacological inhibition of B cell receptor (BCR signaling has recently emerged as an effective approach in a wide range of B lymphoid neoplasms. However, despite promising clinical activity of the first Bruton’s kinase (Btk and spleen tyrosine kinase (Syk inhibitors, a small fraction of patients tend to develop progressive disease after initial response to these agents. Methods We evaluated the antitumor activity of IQS019, a new BCR kinase inhibitor with increased affinity for Btk, Syk, and Lck/Yes novel tyrosine kinase (Lyn, in a set of 34 B lymphoid cell lines and primary cultures, including samples with acquired resistance to the first-in-class Btk inhibitor ibrutinib. Safety and efficacy of the compound were then evaluated in two xenograft mouse models of B cell lymphoma. Results IQS019 simultaneously engaged a rapid and dose-dependent de-phosphorylation of both constitutive and IgM-activated Syk, Lyn, and Btk, leading to impaired cell proliferation, reduced CXCL12-dependent cell migration, and induction of caspase-dependent apoptosis. Accordingly, B cell lymphoma-bearing mice receiving IQS019 presented a reduced tumor outgrowth characterized by a decreased mitotic index and a lower infiltration of malignant cells in the spleen, in tight correlation with downregulation of phospho-Syk, phospho-Lyn, and phospho-Btk. More interestingly, IQS019 showed improved efficacy in vitro and in vivo when compared to the first-in-class Btk inhibitor ibrutinib, and was active in cells with acquired resistance to this latest. Conclusions These results define IQS019 as a potential drug candidate for a variety of B lymphoid neoplasms, including cases with acquired resistance to current BCR-targeting therapies.

  6. Cytokinesis defect in BY-2 cells caused by ATP-competitive kinase inhibitors.

    Science.gov (United States)

    Kozgunova, Elena; Higashiyama, Tetsuya; Kurihara, Daisuke

    2016-10-02

    Cytokinesis is last but not least in cell division as it completes the formation of the two cells. The main role in cell plate orientation and expansion have been assigned to microtubules and kinesin proteins. However, recently we reported severe cytokinesis defect in BY-2 cells not accompanied by changes in microtubules dynamics. Here we also confirmed that distribution of kinesin NACK1 is not the cause of cytokinesis defect. We further explored inhibition of the cell plate expansion by ATP-competitive inhibitors. Two different inhibitors, 5-Iodotubercidin and ML-7 resulted in a very similar phenotype, which indicates that they target same protein cascade. Interestingly, in our previous study we showed that 5-Iodotubercidin treatment affects concentration of actin filaments on the cell plate, while ML-7 is inhibitor of myosin light chain kinase. Although not directly, it indicates importance of actomyosin complex in plant cytokinesis.

  7. Gα12/13 signaling promotes cervical cancer invasion through the RhoA/ROCK-JNK signaling axis

    International Nuclear Information System (INIS)

    Yuan, Bo; Cui, Jinquan; Wang, Wuliang; Deng, Kehong

    2016-01-01

    Several reports have indicated a role for the members of the G12 family of heterotrimeric G proteins (Gα12 and Gα13) in oncogenesis and tumor cell growth. The aims of the present study were to evaluate the role of G12 signaling in cervical cancer. We demonstrated that expression of the G12 proteins was highly upregulated in cervical cancer cells. Additionally, expression of the activated forms of Gα12/Gα13 but not expression of activated Gαq induced cell invasion through the activation of the RhoA family of G proteins, but had no effect on cell proliferation in the cervical cancer cells. Inhibition of G12 signaling by expression of the RGS domain of the p115-Rho-specific guanine nucleotide exchange factor (p115-RGS) blocked thrombin-stimulated cell invasion, but did not inhibit cell proliferation in cervical cells, whereas the inhibition of Gαq (RGS2) had no effect. Furthermore, G12 signaling was able to activate Rho proteins, and this stimulation was inhibited by p115-RGS, and Gα12-induced invasion was blocked by an inhibitor of RhoA/B/C (C3 toxin). Pharmacological inhibition of JNK remarkably decreased G12-induced JNK activation. Both a JNK inhibitor (SP600125) and a ROCK inhibitor (Y27632) reduced G12-induced JNK and c-Jun activation, and markedly inhibited G12-induced cellular invasion. Collectively, these findings demonstrate that stimulation of G12 proteins is capable of promoting invasion through RhoA/ROCK-JNK activation. -- Highlights: •Gα12/Gα13 is upregulated in cervical cancer cell lines. •Gα12/Gα13 is not involved in cervical cancer cell proliferation. •Gα12/Gα13 promotes cervical cancer cell invasion. •The role of Rho G proteins in G12-promoted cervical cancer cell invasion. •G12 promotes cell invasion through activation of the ROCK-JNK signaling axis.

  8. Molecular docking and NMR binding studies to identify novel inhibitors of human phosphomevalonate kinase

    Energy Technology Data Exchange (ETDEWEB)

    Boonsri, Pornthip [Chemical Proteomics Facility at Marquette, Department of Chemistry, Marquette University, Milwaukee, WI 53201 (United States); Department of Chemistry, NANOTEC Center of Nanotechnology, National Nanotechnology Center, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand); Neumann, Terrence S.; Olson, Andrew L.; Cai, Sheng [Chemical Proteomics Facility at Marquette, Department of Chemistry, Marquette University, Milwaukee, WI 53201 (United States); Herdendorf, Timothy J.; Miziorko, Henry M. [Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO 64110 (United States); Hannongbua, Supa [Department of Chemistry, NANOTEC Center of Nanotechnology, National Nanotechnology Center, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand); Sem, Daniel S., E-mail: daniel.sem@cuw.edu [Chemical Proteomics Facility at Marquette, Department of Chemistry, Marquette University, Milwaukee, WI 53201 (United States)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer Natural and synthetic inhibitors of human phosphomevalonate kinase identified. Black-Right-Pointing-Pointer Virtual screening yielded a hit rate of 15%, with inhibitor K{sub d}'s of 10-60 {mu}M. Black-Right-Pointing-Pointer NMR studies indicate significant protein conformational changes upon binding. -- Abstract: Phosphomevalonate kinase (PMK) phosphorylates mevalonate-5-phosphate (M5P) in the mevalonate pathway, which is the sole source of isoprenoids and steroids in humans. We have identified new PMK inhibitors with virtual screening, using autodock. Promising hits were verified and their affinity measured using NMR-based {sup 1}H-{sup 15}N heteronuclear single quantum coherence (HSQC) chemical shift perturbation and fluorescence titrations. Chemical shift changes were monitored, plotted, and fitted to obtain dissociation constants (K{sub d}). Tight binding compounds with K{sub d}'s ranging from 6-60 {mu}M were identified. These compounds tended to have significant polarity and negative charge, similar to the natural substrates (M5P and ATP). HSQC cross peak changes suggest that binding induces a global conformational change, such as domain closure. Compounds identified in this study serve as chemical genetic probes of human PMK, to explore pharmacology of the mevalonate pathway, as well as starting points for further drug development.

  9. Molecular Determinants Underlying Binding Specificities of the ABL Kinase Inhibitors: Combining Alanine Scanning of Binding Hot Spots with Network Analysis of Residue Interactions and Coevolution.

    Directory of Open Access Journals (Sweden)

    Amanda Tse

    Full Text Available Quantifying binding specificity and drug resistance of protein kinase inhibitors is of fundamental importance and remains highly challenging due to complex interplay of structural and thermodynamic factors. In this work, molecular simulations and computational alanine scanning are combined with the network-based approaches to characterize molecular determinants underlying binding specificities of the ABL kinase inhibitors. The proposed theoretical framework unveiled a relationship between ligand binding and inhibitor-mediated changes in the residue interaction networks. By using topological parameters, we have described the organization of the residue interaction networks and networks of coevolving residues in the ABL kinase structures. This analysis has shown that functionally critical regulatory residues can simultaneously embody strong coevolutionary signal and high network centrality with a propensity to be energetic hot spots for drug binding. We have found that selective (Nilotinib and promiscuous (Bosutinib, Dasatinib kinase inhibitors can use their energetic hot spots to differentially modulate stability of the residue interaction networks, thus inhibiting or promoting conformational equilibrium between inactive and active states. According to our results, Nilotinib binding may induce a significant network-bridging effect and enhance centrality of the hot spot residues that stabilize structural environment favored by the specific kinase form. In contrast, Bosutinib and Dasatinib can incur modest changes in the residue interaction network in which ligand binding is primarily coupled only with the identity of the gate-keeper residue. These factors may promote structural adaptability of the active kinase states in binding with these promiscuous inhibitors. Our results have related ligand-induced changes in the residue interaction networks with drug resistance effects, showing that network robustness may be compromised by targeted mutations

  10. Molecular Determinants Underlying Binding Specificities of the ABL Kinase Inhibitors: Combining Alanine Scanning of Binding Hot Spots with Network Analysis of Residue Interactions and Coevolution

    Science.gov (United States)

    Tse, Amanda; Verkhivker, Gennady M.

    2015-01-01

    Quantifying binding specificity and drug resistance of protein kinase inhibitors is of fundamental importance and remains highly challenging due to complex interplay of structural and thermodynamic factors. In this work, molecular simulations and computational alanine scanning are combined with the network-based approaches to characterize molecular determinants underlying binding specificities of the ABL kinase inhibitors. The proposed theoretical framework unveiled a relationship between ligand binding and inhibitor-mediated changes in the residue interaction networks. By using topological parameters, we have described the organization of the residue interaction networks and networks of coevolving residues in the ABL kinase structures. This analysis has shown that functionally critical regulatory residues can simultaneously embody strong coevolutionary signal and high network centrality with a propensity to be energetic hot spots for drug binding. We have found that selective (Nilotinib) and promiscuous (Bosutinib, Dasatinib) kinase inhibitors can use their energetic hot spots to differentially modulate stability of the residue interaction networks, thus inhibiting or promoting conformational equilibrium between inactive and active states. According to our results, Nilotinib binding may induce a significant network-bridging effect and enhance centrality of the hot spot residues that stabilize structural environment favored by the specific kinase form. In contrast, Bosutinib and Dasatinib can incur modest changes in the residue interaction network in which ligand binding is primarily coupled only with the identity of the gate-keeper residue. These factors may promote structural adaptability of the active kinase states in binding with these promiscuous inhibitors. Our results have related ligand-induced changes in the residue interaction networks with drug resistance effects, showing that network robustness may be compromised by targeted mutations of key mediating

  11. Computational-experimental approach to drug-target interaction mapping: A case study on kinase inhibitors.

    Directory of Open Access Journals (Sweden)

    Anna Cichonska

    2017-08-01

    Full Text Available Due to relatively high costs and labor required for experimental profiling of the full target space of chemical compounds, various machine learning models have been proposed as cost-effective means to advance this process in terms of predicting the most potent compound-target interactions for subsequent verification. However, most of the model predictions lack direct experimental validation in the laboratory, making their practical benefits for drug discovery or repurposing applications largely unknown. Here, we therefore introduce and carefully test a systematic computational-experimental framework for the prediction and pre-clinical verification of drug-target interactions using a well-established kernel-based regression algorithm as the prediction model. To evaluate its performance, we first predicted unmeasured binding affinities in a large-scale kinase inhibitor profiling study, and then experimentally tested 100 compound-kinase pairs. The relatively high correlation of 0.77 (p < 0.0001 between the predicted and measured bioactivities supports the potential of the model for filling the experimental gaps in existing compound-target interaction maps. Further, we subjected the model to a more challenging task of predicting target interactions for such a new candidate drug compound that lacks prior binding profile information. As a specific case study, we used tivozanib, an investigational VEGF receptor inhibitor with currently unknown off-target profile. Among 7 kinases with high predicted affinity, we experimentally validated 4 new off-targets of tivozanib, namely the Src-family kinases FRK and FYN A, the non-receptor tyrosine kinase ABL1, and the serine/threonine kinase SLK. Our sub-sequent experimental validation protocol effectively avoids any possible information leakage between the training and validation data, and therefore enables rigorous model validation for practical applications. These results demonstrate that the kernel

  12. Triptolide disrupts the actin-based Sertoli-germ cells adherens junctions by inhibiting Rho GTPases expression

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiang; Zhao, Fang [Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing 210009 (China); Lv, Zhong-ming; Shi, Wei-qin [Jiangsu Provincial Center for Disease Control and Prevention, Nanjing (China); Zhang, Lu-yong, E-mail: lyzhang@cpu.edu.cn [Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing 210009 (China); Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing (China); State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009 (China); Yan, Ming, E-mail: brookming@cpu.edu.cn [Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing 210009 (China)

    2016-11-01

    Triptolide (TP), derived from the medicinal plant Triterygium wilfordii Hook. f. (TWHF), is a diterpene triepoxide with variety biological and pharmacological activities. However, TP has been restricted in clinical application due to its narrow therapeutic window especially in reproductive system. During spermatogenesis, Sertoli cell cytoskeleton plays an essential role in facilitating germ cell movement and cell-cell actin-based adherens junctions (AJ). At Sertoli cell-spermatid interface, the anchoring device is a kind of AJ, known as ectoplasmic specializations (ES). In this study, we demonstrate that β-actin, an important component of cytoskeleton, has been significantly down-regulated after TP treatment. TP can inhibit the expression of Rho GTPase such as, RhoA, RhoB, Cdc42 and Rac1. Downstream of Rho GTPase, Rho-associated protein kinase (ROCKs) gene expressions were also suppressed by TP. F-actin immunofluorescence proved that TP disrupts Sertoli cells cytoskeleton network. As a result of β-actin down-regulation, TP treatment increased expression of testin, which indicating ES has been disassembled. In summary, this report illustrates that TP induces cytoskeleton dysfunction and disrupts cell-cell adherens junctions via inhibition of Rho GTPases. - Highlights: • Triptolide induced the disruption of Sertoli-germ cell adherens junction. • Rho GTPases expression and actin dynamics have been suppressed by triptolide. • Actin-based adherens junction is a potential antifertility target of triptolide. • Rho-Rock is involved in the regulation of actin dynamics.

  13. Triptolide disrupts the actin-based Sertoli-germ cells adherens junctions by inhibiting Rho GTPases expression

    International Nuclear Information System (INIS)

    Wang, Xiang; Zhao, Fang; Lv, Zhong-ming; Shi, Wei-qin; Zhang, Lu-yong; Yan, Ming

    2016-01-01

    Triptolide (TP), derived from the medicinal plant Triterygium wilfordii Hook. f. (TWHF), is a diterpene triepoxide with variety biological and pharmacological activities. However, TP has been restricted in clinical application due to its narrow therapeutic window especially in reproductive system. During spermatogenesis, Sertoli cell cytoskeleton plays an essential role in facilitating germ cell movement and cell-cell actin-based adherens junctions (AJ). At Sertoli cell-spermatid interface, the anchoring device is a kind of AJ, known as ectoplasmic specializations (ES). In this study, we demonstrate that β-actin, an important component of cytoskeleton, has been significantly down-regulated after TP treatment. TP can inhibit the expression of Rho GTPase such as, RhoA, RhoB, Cdc42 and Rac1. Downstream of Rho GTPase, Rho-associated protein kinase (ROCKs) gene expressions were also suppressed by TP. F-actin immunofluorescence proved that TP disrupts Sertoli cells cytoskeleton network. As a result of β-actin down-regulation, TP treatment increased expression of testin, which indicating ES has been disassembled. In summary, this report illustrates that TP induces cytoskeleton dysfunction and disrupts cell-cell adherens junctions via inhibition of Rho GTPases. - Highlights: • Triptolide induced the disruption of Sertoli-germ cell adherens junction. • Rho GTPases expression and actin dynamics have been suppressed by triptolide. • Actin-based adherens junction is a potential antifertility target of triptolide. • Rho-Rock is involved in the regulation of actin dynamics.

  14. Intrinsic, pro-apoptotic effects of IGFBP-3 on breast cancer cells are reversible: Involvement of PKA, Rho and ceramide.

    Directory of Open Access Journals (Sweden)

    Claire M Perks

    2011-05-01

    Full Text Available We established previously that IGFBP-3 could exert positive or negative effects on cell function depending upon the extracellular matrix composition and by interacting with integrin signalling. To elicit its pro-apoptotic effects IGFBP-3 bound to caveolin-1 and the beta 1 integrin receptor and increased their association culminating in MAPK activation. Disruption of these complexes or blocking the beta 1 integrin receptor reversed these intrinsic actions of IGFBP-3. In this study we have examined the signalling pathway between integrin receptor binding and MAPK activation that mediates the intrinsic, pro-apoptotic actions of IGFBP-3. We found on inhibiting protein kinase A(PKA, Rho associated kinase (ROCK and ceramide, the accentuating effects of IGFBP-3 on apoptotic triggers were reversed, such that IGFBP-3 then conferred cell survival. We established that IGFBP-3 activated Rho, the upstream regulator of ROCK and that beta1 integrin and PKA were upstream of Rho activation, whereas the involvement of ceramide was downstream. The beta 1 integrin, PKA, Rho and ceramide were all upstream of MAPK activation. These data highlight key components involved in the pro-apoptotic effects of IGFBP-3 and that inhibiting them leads to a reversal in the action of IGFBP-3.

  15. The tyrosine kinase inhibitor imatinib mesylate suppresses uric acid crystal-induced acute gouty arthritis in mice.

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    Laurent L Reber

    Full Text Available Gouty arthritis is caused by the deposition of monosodium urate (MSU crystals in joints. Despite many treatment options for gout, there is a substantial need for alternative treatments for patients unresponsive to current therapies. Tyrosine kinase inhibitors have demonstrated therapeutic benefit in experimental models of antibody-dependent arthritis and in rheumatoid arthritis in humans, but to date, the potential effects of such inhibitors on gouty arthritis has not been evaluated. Here we demonstrate that treatment with the tyrosine kinase inhibitor imatinib mesylate (imatinib can suppress inflammation induced by injection of MSU crystals into subcutaneous air pouches or into the ankle joint of wild type mice. Moreover, imatinib treatment also largely abolished the lower levels of inflammation which developed in IL-1R1-/- or KitW-sh/W-sh mice, indicating that this drug can inhibit IL-1-independent pathways, as well as mast cell-independent pathways, contributing to pathology in this model. Imatinib treatment not only prevented ankle swelling and synovial inflammation when administered before MSU crystals but also diminished these features when administrated after the injection of MSU crystals, a therapeutic protocol more closely mimicking the clinical situation in which treatment occurs after the development of an acute gout flare. Finally, we also assessed the efficiency of local intra-articular injections of imatinib-loaded poly(lactic-co-glycolic acid (PLGA nanoparticles in this model of acute gout. Treatment with low doses of this long-acting imatinib:PLGA formulation was able to reduce ankle swelling in a therapeutic protocol. Altogether, these results raise the possibility that tyrosine kinase inhibitors might have utility in the treatment of acute gout in humans.

  16. Paroxetine Is a Direct Inhibitor of G Protein-Coupled Receptor Kinase 2 and Increases Myocardial Contractility

    Energy Technology Data Exchange (ETDEWEB)

    Thal, David M. [Univ. of Michigan, Ann Arbor, MI (United States); Homan, Kristoff T. [Univ. of Michigan, Ann Arbor, MI (United States); Chen, Jun [Univ. of New Mexico Health Sciences Center, Albuquerque, NM (United States); Wu, Emily K. [Univ. of Michigan, Ann Arbor, MI (United States); Hinkle, Patricia M. [Univ. of Rochester Medical Center, Rochester, NY (United States); Huang, Z. Maggie [Temple Univ. School of Medicine, Philadelphia, Pennsylvania (United States); Chuprun, J. Kurt [Temple Univ. School of Medicine, Philadelphia, Pennsylvania (United States); Song, Jianliang [Temple Univ. School of Medicine, Philadelphia, Pennsylvania (United States); Gao, Erhe [Temple Univ. School of Medicine, Philadelphia, Pennsylvania (United States); Cheung, Joseph Y. [Temple Univ. School of Medicine, Philadelphia, Pennsylvania (United States); Sklar, Larry A. [Univ. of New Mexico Health Sciences Center, Albuquerque, NM (United States); Koch, Walter J. [Temple Univ. School of Medicine, Philadelphia, Pennsylvania (United States); Tesmer, John J.G. [Univ. of Michigan, Ann Arbor, MI (United States)

    2012-08-10

    G protein-coupled receptor kinase 2 (GRK2) is a well-established therapeutic target for the treatment of heart failure. In this paper we identify the selective serotonin reuptake inhibitor (SSRI) paroxetine as a selective inhibitor of GRK2 activity both in vitro and in living cells. In the crystal structure of the GRK2·paroxetine–Gβγ complex, paroxetine binds in the active site of GRK2 and stabilizes the kinase domain in a novel conformation in which a unique regulatory loop forms part of the ligand binding site. Isolated cardiomyocytes show increased isoproterenol-induced shortening and contraction amplitude in the presence of paroxetine, and pretreatment of mice with paroxetine before isoproterenol significantly increases left ventricular inotropic reserve in vivo with no significant effect on heart rate. Neither is observed in the presence of the SSRI fluoxetine. Our structural and functional results validate a widely available drug as a selective chemical probe for GRK2 and represent a starting point for the rational design of more potent and specific GRK2 inhibitors.

  17. Solo, a RhoA-targeting guanine nucleotide exchange factor, is critical for hemidesmosome formation and acinar development in epithelial cells.

    Science.gov (United States)

    Fujiwara, Sachiko; Matsui, Tsubasa S; Ohashi, Kazumasa; Deguchi, Shinji; Mizuno, Kensaku

    2018-01-01

    Cell-substrate adhesions are essential for various physiological processes, including embryonic development and maintenance of organ functions. Hemidesmosomes (HDs) are multiprotein complexes that attach epithelial cells to the basement membrane. Formation and remodeling of HDs are dependent on the surrounding mechanical environment; however, the upstream signaling mechanisms are not well understood. We recently reported that Solo (also known as ARHGEF40), a guanine nucleotide exchange factor targeting RhoA, binds to keratin8/18 (K8/K18) intermediate filaments, and that their interaction is important for force-induced actin and keratin cytoskeletal reorganization. In this study, we show that Solo co-precipitates with an HD protein, β4-integrin. Co-precipitation assays revealed that the central region (amino acids 330-1057) of Solo binds to the C-terminal region (1451-1752) of β4-integrin. Knockdown of Solo significantly suppressed HD formation in MCF10A mammary epithelial cells. Similarly, knockdown of K18 or treatment with Y-27632, a specific inhibitor of Rho-associated kinase (ROCK), suppressed HD formation. As Solo knockdown or Y-27632 treatment is known to disorganize K8/K18 filaments, these results suggest that Solo is involved in HD formation by regulating K8/K18 filament organization via the RhoA-ROCK signaling pathway. We also showed that knockdown of Solo impairs acinar formation in MCF10A cells cultured in 3D Matrigel. In addition, Solo accumulated at the site of traction force generation in 2D-cultured MCF10A cells. Taken together, these results suggest that Solo plays a crucial role in HD formation and acinar development in epithelial cells by regulating mechanical force-induced RhoA activation and keratin filament organization.

  18. [Protein kinase A inhibitor H-89 blocks polyploidization of SP600125-induced CMK cells by regulating phosphorylation of ribosomal protein S6 kinase 1].

    Science.gov (United States)

    Zhao, Song; Yang, Jingang; Li, Changling; Xing, Sining; Yu, Ying; Liu, Shuo; Pu, Feifei; Ma, Dongchu

    2016-10-01

    Objective To investigate the regulatory effect of post-translation modification of ribosomal protein S6 kinase 1 (S6K1) on the polyploidization of megakaryocytes. Methods SP600125, a c-Jun N-terminal kinase (JNK) inhibitor, and H-89, a cAMP-dependent protein kinase (PKA) inhibitor, were used to treat CMK cells separately or in combination. With propidium iodide (PI) to dye DNA in the treated cells, the relative DNA content was detected by flow cytometry, and then the DNA polyploidy was analyzed. The change of expression and phosphorylation of ribosomal protein S6 kinase 1 (S6K1), an important mammalian target of rapamycin (mTOR) downstream target molecule, was analyzed by Western blotting. Molecular docking study and kinase activity assay were performed to analyze the combination of H-89 with S6K1 and the effect of H-89 on the activity of S6K1 kinase. Results SP600125 induced CMK cell polyploidization in a time-dependent and dose-dependent manner. At the same time, it increased the phosphorylation of S6K1 at Thr421/Ser424 and decreased the phosphorylation of S6K1 at Thr389. H-89 not only blocked polyploidization, but also decreased the phosphorylation of S6K1 at Thr421/Ser424 and increased the phosphorylation of S6K1 at Thr389. Molecular docking and kinase activity assay showed that H-89 occupied the ATP binding sites of S6K1 and inhibited its activity. Noticeably, both H-89 and SP600125 inhibited the activity of PKA. Moreover, the two drugs further inhibited the activity of PKA when used together. Therefore, these data indicated that H-89 blocked the SP600125-induced polyploidization of CMK cells mainly by changing S6K1 phosphorylation state, rather than its inhibitory effect on PKA. Conclusion H-89 can block the polyploidization of SP600125-induced CMK cells by regulating S6K1 phosphorylation state.

  19. BRAF and RAS oncogenes regulate Rho GTPase pathways to mediate migration and invasion properties in human colon cancer cells: a comparative study

    Directory of Open Access Journals (Sweden)

    Shirasawa Senji

    2011-09-01

    Full Text Available Abstract Background Colorectal cancer is a common disease that involves genetic alterations, such as inactivation of tumour suppressor genes and activation of oncogenes. Among them are RAS and BRAF mutations, which rarely coexist in the same tumour. Individual members of the Rho (Ras homology GTPases contribute with distinct roles in tumour cell morphology, invasion and metastasis. The aim of this study is to dissect cell migration and invasion pathways that are utilised by BRAFV600E as compared to KRASG12V and HRASG12V oncoproteins. In particular, the role of RhoA (Ras homolog gene family, member A, Rac1 (Ras-related C3 botulinum toxin substrate 1 and Cdc42 (cell division cycle 42 in cancer progression induced by each of the three oncogenes is described. Methods Colon adenocarcinoma cells with endogenous as well as ectopically expressed or silenced oncogenic mutations of BRAFV600E, KRASG12V and HRASG12V were employed. Signalling pathways and Rho GTPases were inhibited with specific kinase inhibitors and siRNAs. Cell motility and invasion properties were correlated with cytoskeletal properties and Rho GTPase activities. Results Evidence presented here indicate that BRAFV600E significantly induces cell migration and invasion properties in vitro in colon cancer cells, at least in part through activation of RhoA GTPase. The relationship established between BRAFV600E and RhoA activation is mediated by the MEK-ERK pathway. In parallel, KRASG12V enhances the ability of colon adenocarcinoma cells Caco-2 to migrate and invade through filopodia formation and PI3K-dependent Cdc42 activation. Ultimately increased cell migration and invasion, mediated by Rac1, along with the mesenchymal morphology obtained through the Epithelial-Mesenchymal Transition (EMT were the main characteristics rendered by HRASG12V in Caco-2 cells. Moreover, BRAF and KRAS oncogenes are shown to cooperate with the TGFβ-1 pathway to provide cells with additional transforming

  20. Treatment of vitiligo with the topical Janus kinase inhibitor ruxolitinib.

    Science.gov (United States)

    Rothstein, Brooke; Joshipura, Deep; Saraiya, Ami; Abdat, Rana; Ashkar, Huda; Turkowski, Yana; Sheth, Vaneeta; Huang, Victor; Au, Shiu Chung; Kachuk, Courtney; Dumont, Nicole; Gottlieb, Alice B; Rosmarin, David

    2017-06-01

    Existing therapies for vitiligo are limited in efficacy and can be associated with undesirable side effects. Topical Janus kinase inhibitors may offer a new therapeutic option for vitiligo. We sought to assess the role of topical ruxolitinib 1.5% cream, a Janus kinase inhibitor, in vitiligo treatment. This 20-week, open-label, proof-of-concept trial of twice-daily topical ruxolitinib 1.5% cream was conducted in 12 patients with a minimum of 1% affected body surface area of vitiligo. The primary outcome was percent improvement in Vitiligo Area Scoring Index from baseline to week 20. Of 12 patients screened, 11 were enrolled and 9 completed the study (54.5% men; mean age, 52 years). Four patients with significant facial involvement at baseline had a 76% improvement in facial Vitiligo Area Scoring Index scores at week 20 (95% confidence interval, 53-99%; P = .001). A 23% improvement in overall Vitiligo Area Scoring Index scores was observed in all enrolled patients at week 20 (95% confidence interval, 4-43%; P = .02). Three of 8 patients responded on body surfaces and 1 of 8 patients responded on acral surfaces. Adverse events were minor, including erythema, hyperpigmentation, and transient acne. Limitations of the study include the small sample size and open-label study design. Topical ruxolitinib 1.5% cream provided significant repigmentation in facial vitiligo and may offer a valuable new treatment for vitiligo. Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  1. Tyrosine kinase inhibitors for brain metastases in HER2-positive breast cancer.

    Science.gov (United States)

    Duchnowska, Renata; Loibl, Sibylle; Jassem, Jacek

    2018-06-01

    Approximately 30-50% of advanced HER2-positive breast cancer patients will develop central nervous system (CNS) metastases, with an annual risk of around 10%, and a half of them will die from brain progression. An increased risk of brain metastases is also seen in patients with early HER2-positive breast cancer administered curative therapy. Brain metastases in HER2-positive breast cancer patients usually constitute the first site of recurrence. The administration of anti-HER2 monoclonal antibodies, trastuzumab and pertuzumab, considerably delays the onset of symptomatic brain disease: however, the limited penetration of these compounds into the CNS hinders their efficacy. The small-molecule tyrosine kinase inhibitors of epidermal growth factor receptors family have established activity in HER2-positive breast cancer in both advanced disease and neoadjuvant setting. Favorable physico-chemical properties of these compounds allow them for a more efficient penetration through the blood-brain barrier, and hold the promise for more effective prevention and treatment of brain metastases. In this article we review the role of currently available or investigational HER2 tyrosine kinase inhibitors: lapatinib, neratinib, afatinib and tucatinib in the treatment of brain metastases in HER2-positive breast cancer patients. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Substituted aminopyrimidine protein kinase B (PknB) inhibitors show activity against Mycobacterium tuberculosis

    Science.gov (United States)

    Chapman, Timothy M.; Bouloc, Nathalie; Buxton, Roger S.; Chugh, Jasveen; Lougheed, Kathryn E.A.; Osborne, Simon A.; Saxty, Barbara; Smerdon, Stephen J.; Taylor, Debra L.; Whalley, David

    2012-01-01

    A high-throughput screen against PknB, an essential serine–threonine protein kinase present in Mycobacterium tuberculosis (M. tuberculosis), allowed the identification of an aminoquinazoline inhibitor which was used as a starting point for SAR investigations. Although a significant improvement in enzyme affinity was achieved, the aminoquinazolines showed little or no cellular activity against M. tuberculosis. However, switching to an aminopyrimidine core scaffold and the introduction of a basic amine side chain afforded compounds with nanomolar enzyme binding affinity and micromolar minimum inhibitory concentrations against M. tuberculosis. Replacement of the pyrazole head group with pyridine then allowed equipotent compounds with improved selectivity against a human kinase panel to be obtained. PMID:22469702

  3. Selectivity Profiling and Biological Activity of Novel β-Carbolines as Potent and Selective DYRK1 Kinase Inhibitors.

    Directory of Open Access Journals (Sweden)

    Katharina Rüben

    Full Text Available DYRK1A is a pleiotropic protein kinase with diverse functions in cellular regulation, including cell cycle control, neuronal differentiation, and synaptic transmission. Enhanced activity and overexpression of DYRK1A have been linked to altered brain development and function in Down syndrome and neurodegenerative diseases such as Alzheimer's disease. The β-carboline alkaloid harmine is a high affinity inhibitor of DYRK1A but suffers from the drawback of inhibiting monoamine oxidase A (MAO-A with even higher potency. Here we characterized a series of novel harmine analogs with minimal or absent MAO-A inhibitory activity. We identified several inhibitors with submicromolar potencies for DYRK1A and selectivity for DYRK1A and DYRK1B over the related kinases DYRK2 and HIPK2. An optimized inhibitor, AnnH75, inhibited CLK1, CLK4, and haspin/GSG2 as the only off-targets in a panel of 300 protein kinases. In cellular assays, AnnH75 dose-dependently reduced the phosphorylation of three known DYRK1A substrates (SF3B1, SEPT4, and tau without negative effects on cell viability. AnnH75 inhibited the cotranslational tyrosine autophosphorylation of DYRK1A and threonine phosphorylation of an exogenous substrate protein with similar potency. In conclusion, we have characterized an optimized β-carboline inhibitor as a highly selective chemical probe that complies with desirable properties of drug-like molecules and is suitable to interrogate the function of DYRK1A in biological studies.

  4. Quinolinone and pyridopyrimidinone inhibitors of DNA-dependent protein kinase.

    Science.gov (United States)

    Barbeau, Olivier R; Cano-Soumillac, Celine; Griffin, Roger J; Hardcastle, Ian R; Smith, Graeme C M; Richardson, Caroline; Clegg, William; Harrington, Ross W; Golding, Bernard T

    2007-08-21

    8-Substituted 2-morpholin-4-yl-quinolin-4-ones and 9-substituted 2-morpholin-4-yl-pyrido[1,2-a]pyrimidin-4-ones with selected aryl and heteroaryl groups as the substituent have been synthesised as potential inhibitors of DNA-dependent protein kinase. A multiple-parallel approach, employing Suzuki cross-coupling methodology, was utilised in the preparation of 8-substituted 2-morpholin-4-yl-quinolin-4-ones. For this purpose 8-bromo-2-morpholin-4-yl-quinolin-4-one was required as an intermediate. This compound was obtained by adapting a literature route in which thermal cyclocondensation of (2-bromoanilino)-morpholin-4-yl-5-methylene-2,2-dimethyl[1,3]dioxane-4,6-dione afforded 8-bromo-2-morpholin-4-yl-quinolin-4-one. A multiple-parallel approach, employing Suzuki cross-coupling methodology, was also utilised to prepare 9-substituted 2-morpholin-4-yl-pyrido[1,2-a]pyrimidin-4-ones using 9-hydroxy-2-morpholin-4-yl-pyrido[1,2-a]pyrimidin-4-one O-trifluoromethanesulfonate as an intermediate. 8-Substituted 2-morpholin-4-yl-quinolin-4-ones and 9-substituted 2-morpholin-4-yl-pyrido[1,2-a]pyrimidin-4-ones were both inhibitors of DNA-dependent protein kinase. When the substituent was dibenzothiophen-4-yl, dibenzofuran-4-yl or biphen-3-yl, IC50 values in the low nanomolar range were observed. Interestingly, the pyridopyrimidinones and quinolinones were essentially equipotent with the corresponding 8-substituted 2-morpholin-4-yl-chromen-4-ones previously reported (I. R. Hardcastle, X. Cockcroft, N. J. Curtin, M. Desage El-Murr, J. J. J. Leahy, M. Stockley, B. T. Golding, L. Rigoreau, C. Richardson, G. C. M. Smith and R. J. Griffin, J. Med. Chem., 2005, 48, 7829-7846).

  5. Are Janus Kinase Inhibitors Superior over Classic Biologic Agents in RA Patients?

    Directory of Open Access Journals (Sweden)

    Przemyslaw J. Kotyla

    2018-01-01

    Full Text Available The Janus Kinases (JAKs are a family of intracellular tyrosine kinases that provide transmission signals from cytokine, interferons, and many hormones receptors to the nucleus resulting in synthesis of many biologically active compounds and changing cell metabolism and function. That was theoretical background to synthetize the JAK inhibitors (Jakinibs. In recent years a substantial battery of evidence has been collected indicating the potential role of Jakinibs to interact with the specific elements of the immune system, therefore changing the inflammatory response. JAK kinase blockade offers a unique opportunity to block most of the key cytokines enabling the deep interaction into immune system functioning. Following discovery first Jakinibs were intensively studied in various forms of autoimmune diseases, including rheumatoid arthritis, and finally two Jakinibs tofacitinib and Baricitinib have been approved for the treatment of rheumatoid arthritis. Some clinical data indicated that under special circumstances Jakinibs may be even superior to biologics in the treatment of RA; however this suggestion should be verified in large clinical and observational studies.

  6. Extremely low frequency electromagnetic fields promote mesenchymal stem cell migration by increasing intracellular Ca2+ and activating the FAK/Rho GTPases signaling pathways in vitro.

    Science.gov (United States)

    Zhang, Yingchi; Yan, Jiyuan; Xu, Haoran; Yang, Yong; Li, Wenkai; Wu, Hua; Liu, Chaoxu

    2018-05-21

    The ability of mesenchymal stem cells (MSCs) to migrate to the desired tissues or lesions is crucial for stem cell-based regenerative medicine and tissue engineering. Optimal therapeutics for promoting MSC migration are expected to become an effective means for tissue regeneration. Electromagnetic fields (EMF), as a noninvasive therapy, can cause a lot of biological changes in MSCs. However, whether EMF can promote MSC migration has not yet been reported. We evaluated the effects of EMF on cell migration in human bone marrow-derived MSCs. With the use of Helmholtz coils and an EMF stimulator, 7.5, 15, 30, 50, and 70 Hz/1 mT EMF was generated. Additionally, we employed the L-type calcium channel blocker verapamil and the focal adhesion kinase (FAK) inhibitor PF-573228 to investigate the role of intracellular calcium content, cell adhesion proteins, and the Rho GTPase protein family (RhoA, Rac1, and Cdc42) in EMF-mediated MSC migration. Cell adhesion proteins (FAK, talin, and vinculin) were detected by Western blot analysis. The Rho GTPase protein family activities were assessed by G-LISA, and F-actin levels, which reflect actin cytoskeletal organization, were detected using immunofluorescence. All the 7.5, 15, 30, 50, and 70 Hz/1 mT EMF promoted MSC migration. EMF increased MSC migration in an intracellular calcium-dependent manner. Notably, EMF-enhanced migration was mediated by FAK activation, which was critical for the formation of focal contacts, as evidenced by increased talin and vinculin expression. Moreover, RhoA, Rac1, and Cdc42 were activated by FAK to increase cytoskeletal organization, thus promoting cell contraction. EMF promoted MSC migration by increasing intracellular calcium and activating the FAK/Rho GTPase signaling pathways. This study provides insights into the mechanisms of MSC migration and will enable the rational design of targeted therapies to improve MSC engraftment.

  7. The significance of major and stable molecular responses in chronic myeloid leukemia in the tyrosine kinase inhibitor era

    Directory of Open Access Journals (Sweden)

    Ilana Zalcberg Renault

    2011-12-01

    Full Text Available Tyrosine kinase inhibitors have changed the management and outcomes of chronic myeloid leukemia patients. Quantitative polymerase chain reaction is used to monitor molecular responses to tyrosine kinase inhibitors. Molecular monitoring represents the most sensitive tool to judge chronic myeloid leukemia disease course and allows early detection of relapse. Evidence of achieving molecular response is important for several reasons: 1. early molecular response is associated with major molecular response rates at 18-24 months; 2. patients achieving major molecular response are less likely to lose their complete cytogenetic response; 3. a durable, stable major molecular response is associated with increased progression-free survival. However, standardization of molecular techniques is still challenging.

  8. The significance of major and stable molecular responses in chronic myeloid leukemia in the tyrosine kinase inhibitor era

    Science.gov (United States)

    Renault, Ilana Zalcberg; Scholl, Vanesa; Hassan, Rocio; Capelleti, Paola; de Lima, Marcos; Cortes, Jorge

    2011-01-01

    Tyrosine kinase inhibitors have changed the management and outcomes of chronic myeloid leukemia patients. Quantitative polymerase chain reaction is used to monitor molecular responses to tyrosine kinase inhibitors. Molecular monitoring represents the most sensitive tool to judge chronic myeloid leukemia disease course and allows early detection of relapse. Evidence of achieving molecular response is important for several reasons: 1. early molecular response is associated with major molecular response rates at 18-24 months; 2. patients achieving major molecular response are less likely to lose their complete cytogenetic response; 3. a durable, stable major molecular response is associated with increased progression-free survival. However, standardization of molecular techniques is still challenging. PMID:23049363

  9. Staurosporine scaffold-based rational discovery of the wild-type sparing reversible inhibitors of EGFR T790M gatekeeper mutant in lung cancer with analog-sensitive kinase technology.

    Science.gov (United States)

    Song, Xiaoyun; Liu, Xingcai; Ding, Xi

    2017-04-01

    The human epidermal growth factor receptor (EGFR) has been established as an attractive target for lung cancer therapy. However, an acquired EGFR T790M gatekeeper mutation is frequently observed in patients treated with first-line anticancer agents such as gefitinib and erlotinib to cause drug resistance, largely limiting the application of small-molecule kinase inhibitors in EGFR-targeted chemotherapy. Previously, the reversible pan-kinase inhibitor staurosporine and its several analogs such as Gö6976 and K252a have been reported to selectively inhibit the EGFR T790M mutant (EGFR T790M ) over wild-type kinase (EGFR WT ), suggesting that the staurosporine scaffold is potentially to develop the wild-type sparing reversible inhibitors of EGFR T790M . Here, we systematically evaluated the inhibitor response of 28 staurosporine scaffold-based compounds to EGFR T790M mutation at structural, energetic, and molecular levels by using an integrated in silico-in vitro analog-sensitive (AS) kinase technology. With the strategy, we were able to identify 4 novel wild-type sparing inhibitors UCN-01, UCN-02, AFN941, and SB-218078 with high or moderate selectivity of 30-, 45-, 5-, and 8-fold for EGFR T790M over EGFR WT , respectively, which are comparable with or even better than that of the parent compound staurosporine (24-fold). Molecular modeling and structural analysis revealed that van der Waals contacts and hydrophobic forces can form between the side chain of mutated residue Met790 and the pyrrolidinone moiety of inhibitor ligand UCN-02, which may simultaneously improve the favorable interaction energy between the kinase and inhibitor, and reduce the unfavorable desolvation penalty upon the kinase-inhibitor binding. A hydroxyl group of UCN-02 additional to staurosporine locates at the pyrrolidinone moiety, which can largely alter the electronic distribution of pyrrolidinone moiety and thus promote the intermolecular interaction with Met790 residue. This can well explain

  10. Alteration of radiation response by two tyrosine kinase inhibitors: STI571 (Glivec) and BIBW 2992

    International Nuclear Information System (INIS)

    Huguet, F.

    2010-01-01

    Concurrent chemo-radiation is one of the main weapon in the treatment of cancer. The targeted therapies may act on the mechanisms of tumor resistance to radiation and are therefore very promising in combination with radiotherapy. The STI571 (imatinib or Gleevec) inhibits specifically the Bcr-Abl tyrosine kinase. It leads to radiosensitization in K562 chronic myeloid leukemia cell line by alterations of the cell cycle. The BIBW2992 is a selective inhibitor of EGFR and HER2. The BIBW 2992 shows cytotoxic and radiosensitizing effects on pancreatic adenocarcinoma cells BxPC3 and Capan-2, regardless of KRAS status. The mechanism underlying this radiosensitization is not unequivocal, involving both changes in the cell cycle and induction of mitotic death. Our results show that the combination of an inhibitor of tyrosine kinase with ionizing radiation may lead to a radiosensitization in vitro with mechanisms depending on the type of cell line. (author)

  11. The Role of RhoA, RhoB and RhoC GTPases in Cell Morphology, Proliferation and Migration in Human Cytomegalovirus (HCMV Infected Glioblastoma Cells

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    Melpomeni Tseliou

    2016-01-01

    Full Text Available Background/Aims: Rho GTPases are crucial regulators of the actin cytoskeleton, membrane trafficking and cell signaling and their importance in cell migration and invasion is well- established. The human cytomegalovirus (HCMV is a widespread pathogen responsible for generally asymptomatic and persistent infections in healthy people. Recent evidence indicates that HCMV gene products are expressed in over 90% of malignant type glioblastomas (GBM. In addition, the HCMV Immediate Early-1 protein (IE1 is expressed in >90% of tumors analyzed. Methods: RhoA, RhoB and RhoC were individually depleted in U373MG glioblastoma cells as well as U373MG cells stably expressing the HCMV IE1 protein (named U373MG-IE1 cells shRNA lentivirus vectors. Cell proliferation assays, migration as well as wound-healing assays were performed in uninfected and HCMV-infected cells. Results: The depletion of RhoA, RhoB and RhoC protein resulted in significant alterations in the morphology of the uninfected cells, which were further enhanced by the cytopathic effect caused by HCMV. Furthermore, in the absence or presence of HCMV, the knockdown of RhoB and RhoC proteins decreased the proliferation rate of the parental and the IE1-expressing glioblastoma cells, whereas the knockdown of RhoA protein in the HCMV infected cell lines restored their proliferation rate. In addition, wound healing assays in U373MG cells revealed that depletion of RhoA, RhoB and RhoC differentially reduced their migration rate, even in the presence or the absence of HCMV. Conclusion: Collectively, these data show for the first time a differential implication of Rho GTPases in morphology, proliferation rate and motility of human glioblastoma cells during HCMV infection, further supporting an oncomodulatory role of HCMV depending on the Rho isoforms' state.

  12. Rho GTPases and cancer

    DEFF Research Database (Denmark)

    Li, Hui; Peyrollier, Karine; Kilic, Gülcan

    2014-01-01

    Rho GTPases are a family of small GTPases, which play an important role in the regulation of the actin cytoskeleton. Not surprisingly, Rho GTPases are crucial for cell migration and therefore highly important for cancer cell invasion and the formation of metastases. In addition, Rho GTPases...... are involved in growth and survival of tumor cells, in the interaction of tumor cells with their environment, and they are vital for the cancer supporting functions of the tumor stroma. Recent research has significantly improved our understanding of the regulation of Rho GTPase activity, the specificity of Rho...

  13. Effect and reporting bias of RhoA/ROCK-blockade intervention on locomotor recovery after spinal cord injury: a systematic review and meta-analysis.

    Science.gov (United States)

    Watzlawick, Ralf; Sena, Emily S; Dirnagl, Ulrich; Brommer, Benedikt; Kopp, Marcel A; Macleod, Malcolm R; Howells, David W; Schwab, Jan M

    2014-01-01

    Blockade of small GTPase-RhoA signaling pathway is considered a candidate translational strategy to improve functional outcome after spinal cord injury (SCI) in humans. Pooling preclinical evidence by orthodox meta-analysis is confounded by missing data (publication bias). To conduct a systematic review and meta-analysis of RhoA/Rho-associated coiled-coil containing protein kinase (ROCK) blocking approaches to (1) analyze the impact of bias that may lead to inflated effect sizes and (2) determine the normalized effect size of functional locomotor recovery after experimental thoracic SCI. We conducted a systematic search of PubMed, EMBASE, and Web of Science and hand searched related references. Studies were selected if they reported the effect of RhoA/ROCK inhibitors (C3-exoenzmye, fasudil, Y-27632, ibuprofen, siRhoA, and p21) in experimental spinal cord hemisection, contusion, or transection on locomotor recovery measured by the Basso, Beattie, and Bresnahan score or the Basso Mouse Scale for Locomotion. Two investigators independently assessed the identified studies. Details of individual study characteristics from each publication were extracted and effect sizes pooled using a random effects model. We assessed risk for bias using a 9-point-item quality checklist and calculated publication bias with Egger regression and the trim and fill method. A stratified meta-analysis was used to assess the impact of study characteristics on locomotor recovery. Thirty studies (725 animals) were identified. RhoA/ROCK inhibition was found to improve locomotor outcome by 21% (95% CI, 16.0-26.6). Assessment of publication bias by the trim and fill method suggested that 30% of experiments remain unpublished. Inclusion of these theoretical missing studies suggested a 27% overestimation of efficacy, reducing the overall efficacy to a 15% improvement in locomotor recovery. Low study quality was associated with larger estimates of neurobehavioral outcome. Taking into account

  14. Up-regulation of Rho/ROCK signaling in sarcoma cells drives invasion and increased generation of protrusive forces

    Czech Academy of Sciences Publication Activity Database

    Rosel, D.; Brabek, J.; Tolde, O.; Mierke, C.T.; Zitterbart, D.P.; Raupach, C.; Bicanova, K.; Kollmannsberger, P.; Pánková, D.; Veselý, Pavel; Folk, P.; Fabry, B.

    2008-01-01

    Roč. 6, č. 9 (2008), s. 1410-1420 ISSN 1541-7786 Institutional research plan: CEZ:AV0Z50520514 Keywords : Rho kinase ROCK * traction force microscopy * ameboid invasion Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.533, year: 2008

  15. Accurate calculation of mutational effects on the thermodynamics of inhibitor binding to p38α MAP kinase: a combined computational and experimental study.

    Science.gov (United States)

    Zhu, Shun; Travis, Sue M; Elcock, Adrian H

    2013-07-09

    A major current challenge for drug design efforts focused on protein kinases is the development of drug resistance caused by spontaneous mutations in the kinase catalytic domain. The ubiquity of this problem means that it would be advantageous to develop fast, effective computational methods that could be used to determine the effects of potential resistance-causing mutations before they arise in a clinical setting. With this long-term goal in mind, we have conducted a combined experimental and computational study of the thermodynamic effects of active-site mutations on a well-characterized and high-affinity interaction between a protein kinase and a small-molecule inhibitor. Specifically, we developed a fluorescence-based assay to measure the binding free energy of the small-molecule inhibitor, SB203580, to the p38α MAP kinase and used it measure the inhibitor's affinity for five different kinase mutants involving two residues (Val38 and Ala51) that contact the inhibitor in the crystal structure of the inhibitor-kinase complex. We then conducted long, explicit-solvent thermodynamic integration (TI) simulations in an attempt to reproduce the experimental relative binding affinities of the inhibitor for the five mutants; in total, a combined simulation time of 18.5 μs was obtained. Two widely used force fields - OPLS-AA/L and Amber ff99SB-ILDN - were tested in the TI simulations. Both force fields produced excellent agreement with experiment for three of the five mutants; simulations performed with the OPLS-AA/L force field, however, produced qualitatively incorrect results for the constructs that contained an A51V mutation. Interestingly, the discrepancies with the OPLS-AA/L force field could be rectified by the imposition of position restraints on the atoms of the protein backbone and the inhibitor without destroying the agreement for other mutations; the ability to reproduce experiment depended, however, upon the strength of the restraints' force constant

  16. Upregulated STAT3 and RhoA signaling in colorectal cancer (CRC) regulate the invasion and migration of CRC cells.

    Science.gov (United States)

    Zhang, G-Y; Yang, W-H; Chen, Z

    2016-05-01

    We aimed to reveal the expression and activation of signal transducers and activators of transcription 3 (STAT3) and RhoA/Rho-associated coiled-coil forming kinase 1 (ROCK1) signaling in CRC tissues, and to investigate the regulatory role of STAT3 and RhoA signaling in the invasion and migration of colorectal cancer cells. We examined the expression of STAT3, RhoA and ROCK1 in CRC tissues with real-time PCR and Western blotting methods. And then we examined the interaction between STAT3 and RhoA/ROCK1 signaling in CRC HT-29 cells with gain-of-function and loss-of-function strategies. In addition, we determined the regulation by STAT3 and RhoA/ROCK1 on the invasion and migration of CRC HT-29 cells. Our study demonstrated a significant upregulation of RhoA and ROCK1 expression and STAT3-Y705 phosphorylation in 32 CRC specimens, compared to the 17 normal CRC tissues. Further study demonstrated there was a coordination between STAT3 and RhoA/Rock signaling in the HT-29 cells. Moreover, STAT3 knockdown or RhoA knockdown significantly repressed the migration and invasion in HT-29 cells and vice versa. STAT3 and RhoA signaling regulate the invasion and migration of CRC cells, implying the orchestrated and oncogenic roles of STAT3 and RhoA/ROCK1 signaling in CRC.

  17. Efficacy of cyclin dependent kinase 4 inhibitors as potent neuroprotective agents against insults relevant to Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Priyankar Sanphui

    Full Text Available Alzheimer's disease (AD is a progressive neurodegenerative disease with no cure till today. Aberrant activation of cell cycle regulatory proteins is implicated in neurodegenerative diseases including AD. We and others have shown that Cyclin dependent kinase 4 (Cdk4 is activated in AD brain and is required for neuron death. In this study, we tested the efficiency of commercially available Cdk4 specific inhibitors as well as a small library of synthetic molecule inhibitors targeting Cdk4 as neuroprotective agents in cellular models of neuron death. We found that several of these inhibitors significantly protected neuronal cells against death induced by nerve growth factor (NGF deprivation and oligomeric beta amyloid (Aβ that are implicated in AD. These neuroprotective agents inhibit specifically Cdk4 kinase activity, loss of mitochondrial integrity, induction of pro-apoptotic protein Bim and caspase3 activation in response to NGF deprivation. The efficacies of commercial and synthesized inhibitors are comparable. The synthesized molecules are either phenanthrene based or naphthalene based and they are synthesized by using Pschorr reaction and Buchwald coupling respectively as one of the key steps. A number of molecules of both kinds block neurodegeneration effectively. Therefore, we propose that Cdk4 inhibition would be a therapeutic choice for ameliorating neurodegeneration in AD and these synthetic Cdk4 inhibitors could lead to development of effective drugs for AD.

  18. Enantioselective synthesis of the novel chiral sulfoxide derivative as a glycogen synthase kinase 3beta inhibitor.

    Science.gov (United States)

    Saitoh, Morihisa; Kunitomo, Jun; Kimura, Eiji; Yamano, Toru; Itoh, Fumio; Kori, Masakuni

    2010-09-01

    Glycogen synthase kinase 3beta (GSK-3beta) inhibitors are expected to be attractive therapeutic agents for the treatment of Alzheimer's disease (AD). Recently we discovered sulfoxides (S)-1 as a novel GSK-3beta inhibitor having in vivo efficacy. We investigated practical asymmetric preparation methods for the scale-up synthesis of (S)-1. The highly enantioselective synthesis of (S)-1 (94% ee) was achieved by titanium-mediated oxidation with D-(-)-diethyl tartrate on gram scale.

  19. Fragment-based lead discovery of small molecule inhibitors for the EPHA4 receptor tyrosine kinase

    NARCIS (Netherlands)

    van Linden, O.P.J.; Farenc, C; Zoutman, W.H.; Hameetman, L; Wijtmans, M.; Leurs, R.; Tensen, C.P.; Siegal, G.; de Esch, I.J.P.

    2011-01-01

    The in silico identification, optimization and crystallographic characterization of a 6,7,8,9-tetrahydro-3H-pyrazolo[3,4-c]isoquinolin-1-amine scaffold as an inhibitor for the EPHA4 receptor tyrosine kinase is described. A database containing commercially available compounds was subjected to an in

  20. Protocols for the Design of Kinase-focused Compound Libraries.

    Science.gov (United States)

    Jacoby, Edgar; Wroblowski, Berthold; Buyck, Christophe; Neefs, Jean-Marc; Meyer, Christophe; Cummings, Maxwell D; van Vlijmen, Herman

    2018-05-01

    Protocols for the design of kinase-focused compound libraries are presented. Kinase-focused compound libraries can be differentiated based on the design goal. Depending on whether the library should be a discovery library specific for one particular kinase, a general discovery library for multiple distinct kinase projects, or even phenotypic screening, there exists today a variety of in silico methods to design candidate compound libraries. We address the following scenarios: 1) Datamining of SAR databases and kinase focused vendor catalogues; 2) Predictions and virtual screening; 3) Structure-based design of combinatorial kinase inhibitors; 4) Design of covalent kinase inhibitors; 5) Design of macrocyclic kinase inhibitors; and 6) Design of allosteric kinase inhibitors and activators. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Optimization of microtubule affinity regulating kinase (MARK) inhibitors with improved physical properties

    Energy Technology Data Exchange (ETDEWEB)

    Sloman, David L.; Noucti, Njamkou; Altman, Michael D.; Chen, Dapeng; Mislak, Andrea C.; Szewczak, Alexander; Hayashi, Mansuo; Warren, Lee; Dellovade, Tammy; Wu, Zhenhua; Marcus, Jacob; Walker, Deborah; Su, Hua-Poo; Edavettal, Suzanne C.; Munshi, Sanjeev; Hutton, Michael; Nuthall, Hugh; Stanton, Matthew G. (Merck)

    2016-09-01

    Inhibition of microtubule affinity regulating kinase (MARK) represents a potentially attractive means of arresting neurofibrillary tangle pathology in Alzheimer’s disease. This manuscript outlines efforts to optimize a pyrazolopyrimidine series of MARK inhibitors by focusing on improvements in potency, physical properties and attributes amenable to CNS penetration. A unique cylcyclohexyldiamine scaffold was identified that led to remarkable improvements in potency, opening up opportunities to reduce MW, Pgp efflux and improve pharmacokinetic properties while also conferring improved solubility.

  2. An in silico high-throughput screen identifies potential selective inhibitors for the non-receptor tyrosine kinase Pyk2

    Directory of Open Access Journals (Sweden)

    Meirson T

    2017-05-01

    Full Text Available Tomer Meirson, Abraham O Samson, Hava Gil-Henn Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel Abstract: The non-receptor tyrosine kinase proline-rich tyrosine kinase 2 (Pyk2 is a critical mediator of signaling from cell surface growth factor and adhesion receptors to cell migration, proliferation, and survival. Emerging evidence indicates that signaling by Pyk2 regulates hematopoietic cell response, bone density, neuronal degeneration, angiogenesis, and cancer. These physiological and pathological roles of Pyk2 warrant it as a valuable therapeutic target for invasive cancers, osteoporosis, Alzheimer’s disease, and inflammatory cellular response. Despite its potential as a therapeutic target, no potent and selective inhibitor of Pyk2 is available at present. As a first step toward discovering specific potential inhibitors of Pyk2, we used an in silico high-throughput screening approach. A virtual library of six million lead-like compounds was docked against four different high-resolution Pyk2 kinase domain crystal structures and further selected for predicted potency and ligand efficiency. Ligand selectivity for Pyk2 over focal adhesion kinase (FAK was evaluated by comparative docking of ligands and measurement of binding free energy so as to obtain 40 potential candidates. Finally, the structural flexibility of a subset of the docking complexes was evaluated by molecular dynamics simulation, followed by intermolecular interaction analysis. These compounds may be considered as promising leads for further development of highly selective Pyk2 inhibitors. Keywords: virtual screen, efficiency metrics, MM-GBSA, molecular dynamics

  3. Arhgap28 is a RhoGAP that inactivates RhoA and downregulates stress fibers.

    Directory of Open Access Journals (Sweden)

    Ching-Yan Chloé Yeung

    Full Text Available The small GTPase RhoA is a major regulator of actin reorganization during the formation of stress fibers; thus identifying molecules that regulate Rho activity is necessary for a complete understanding of the mechanisms that determine cell contractility. Here, we have identified Arhgap28 as a Rho GTPase activating protein (RhoGAP that switches RhoA to its inactive form. We generated an Arhgap28-LacZ reporter mouse that revealed gene expression in soft tissues at E12.5, pre-bone structures of the limb at E15.5, and prominent expression restricted mostly to ribs and limb long bones at E18.5 days of development. Expression of recombinant Arhgap28-V5 in human osteosarcoma SaOS-2 cells caused a reduction in the basal level of RhoA activation and disruption of actin stress fibers. Extracellular matrix assembly studies using a 3-dimensional cell culture system showed that Arhgap28 was upregulated during Rho-dependent assembly of the ECM. Taken together, these observations led to the hypothesis that an Arhgap28 knockout mouse model would show a connective tissue phenotype, perhaps affecting bone. Arhgap28-null mice were viable and appeared normal, suggesting that there could be compensation from other RhoGAPs. Indeed, we showed that expression of Arhgap6 (a closely related RhoGAP was upregulated in Arhgap28-null bone tissue. An upregulation in RhoA expression was also detected suggesting that Arhgap28 may be able to additionally regulate Rho signaling at a transcriptional level. Microarray analyses revealed that Col2a1, Col9a1, Matn3, and Comp that encode extracellular matrix proteins were downregulated in Arhgap28-null bone. Although mutations in these genes cause bone dysplasias no bone phenotype was detected in the Arhgap-28 null mice. Together, these data suggest that the regulation of Rho by RhoGAPs, including Arhgap28, during the assembly and development of mechanically strong tissues is complex and may involve multiple RhoGAPs.

  4. Tyrosine Kinase Inhibitor Treatment for Newly Diagnosed Chronic Myeloid Leukemia.

    Science.gov (United States)

    Radich, Jerald P; Mauro, Michael J

    2017-08-01

    Chronic myeloid leukemia (CML) is a myeloproliferative disorder that accounts for approximately 10% of new cases of leukemia. The introduction of tyrosine kinase inhibitors has led to a reduction in mortalities. Thus, the estimated prevalence of CML is increasing. The National Comprehensive Cancer Network and the European Leukemia Net guidelines incorporate frequent molecular monitoring of the fusion BCR-ABL transcript to ensure that patients reach and keep treatment milestones. Most patients with CML are diagnosed in the chronic phase, and approximately 10% to 30% of these patients will at some time in their course meet definition criteria of resistance to imatinib. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. A Point Mutation in p190A RhoGAP Affects Ciliogenesis and Leads to Glomerulocystic Kidney Defects.

    Directory of Open Access Journals (Sweden)

    Katherine Stewart

    2016-02-01

    Full Text Available Rho family GTPases act as molecular switches regulating actin cytoskeleton dynamics. Attenuation of their signaling capacity is provided by GTPase-activating proteins (GAPs, including p190A, that promote the intrinsic GTPase activity of Rho proteins. In the current study we have performed a small-scale ENU mutagenesis screen and identified a novel loss of function allele of the p190A gene Arhgap35, which introduces a Leu1396 to Gln substitution in the GAP domain. This results in decreased GAP activity for the prototypical Rho-family members, RhoA and Rac1, likely due to disrupted ordering of the Rho binding surface. Consequently, Arhgap35-deficient animals exhibit hypoplastic and glomerulocystic kidneys. Investigation into the cystic phenotype shows that p190A is required for appropriate primary cilium formation in renal nephrons. P190A specifically localizes to the base of the cilia to permit axoneme elongation, which requires a functional GAP domain. Pharmacological manipulations further reveal that inhibition of either Rho kinase (ROCK or F-actin polymerization is able to rescue the ciliogenesis defects observed upon loss of p190A activity. We propose a model in which p190A acts as a modulator of Rho GTPases in a localized area around the cilia to permit the dynamic actin rearrangement required for cilia elongation. Together, our results establish an unexpected link between Rho GTPase regulation, ciliogenesis and glomerulocystic kidney disease.

  6. Measurement of Exclusive $\\rho^+ \\rho^-$ Production in High-$Q^2$ Two-Photon Collisions at LEP

    CERN Document Server

    Achard, P.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M.G.; Anderhub, H.; Andreev, Valery P.; Anselmo, F.; Arefev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S.V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillere, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B.L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J.J.; Blyth, S.C.; Bobbink, G.J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J.G.; Brochu, F.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y.H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G.M.; Chen, H.F.; Chen, H.S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; van Dalen, J.A.; de Asmundis, R.; Deglon, P.; Debreczeni, J.; Degre, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M.T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F.J.; Extermann, P.; Falagan, M.A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J.H.; Filthaut, F.; Fisher, P.H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Iouri; Ganguli, S.N.; Garcia-Abia, Pablo; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z.F.; Grenier, Gerald Jean; Grimm, O.; Gruenewald, M.W.; Guida, M.; Gupta, V.K.; Gurtu, A.; Gutay, L.J.; Haas, D.; Hatzifotiadou, D.; Hebbeker, T.; Herve, Alain; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S.R.; Hu, Y.; Jin, B.N.; Jones, Lawrence W.; de Jong, P.; Josa-Mutuberria, I.; Kaur, M.; Kienzle-Focacci, M.N.; Kim, J.K.; Kirkby, Jasper; Kittel, W.; Klimentov, A.; Konig, A.C.; Kopal, M.; Koutsenko, V.; Kraber, M.; Kraemer, R.W.; Kruger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J.M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C.H.; Lin, W.T.; Linde, F.L.; Lista, L.; Liu, Z.A.; Lohmann, W.; Longo, E.; Lu, Y.S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W.G.; Malgeri, L.; Malinin, A.; Mana, C.; Mans, J.; Martin, J.P.; Marzano, F.; Mazumdar, K.; McNeil, R.R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W.J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G.B.; Muanza, G.S.; Muijs, A.J.M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Kluge, Hannelies; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, Thomas Cantzon; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroue, P.A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, Mohammad Azizur; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, Keith; Roe, B.P.; Romero, L.; Rosca, A.; Rosemann, C.; Rosenbleck, C.; Rosier-Lees, S.; Roth, Stefan; Rubio, J.A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schafer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D.J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D.P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L.Z.; Sushkov, S.; Suter, H.; Swain, J.D.; Szillasi, Z.; Tang, X.W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, Charles; Ting, Samuel C.C.; Ting, S.M.; Tonwar, S.C.; Toth, J.; Tully, C.; Tung, K.L.; Ulbricht, J.; Valente, E.; Van de Walle, R.T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobev, I.; Vorobyov, A.A.; Wadhwa, M.; Wang, Q.; Wang, X.L.; Wang, Z.M.; Weber, M.; Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Z.Z.; Yamamoto, J.; Yang, B.Z.; Yang, C.G.; Yang, H.J.; Yang, M.; Yeh, S.C.; Zalite, An.; Zalite, Yu.; Zhang, Z.P.; Zhao, J.; Zhu, G.Y.; Zhu, R.Y.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.; Zoller, M.

    2004-01-01

    Exclusive rho^+ rho^- production in two-photon collisions involving a single highly-virtual photon is studied with data collected at LEP at centre-of-mass energies 89 GeV rho^+ rho^- is determined as a function of the photon virtuality, Q^2, and the two-photon centre-of-mass energy, W_gg, in the kinematic region: 1.2 GeV^2 rho^0 rho^0, measured in the same kinematic region by L3, and to have similar W_gg and Q^2 dependences.

  7. RhoGDI: multiple functions in the regulation of Rho family GTPase activities

    DEFF Research Database (Denmark)

    Dovas, Athanassios; Couchman, John R

    2005-01-01

    necessary for the correct targeting and regulation of Rho activities by conferring cues for spatial restriction, guidance and availability to effectors. These potential functions are discussed in the context of RhoGDI-associated multimolecular complexes, the newly emerged shuttling capability...... insight as to how RhoGDI exerts its effects on nucleotide binding, the membrane association-dissociation cycling of the GTPase and how these activities are controlled. Despite the initial negative roles attributed to RhoGDI, recent evidence has come to suggest that it may also act as a positive regulator...... of activities....

  8. Termination factor Rho: From the control of pervasive transcription to cell fate determination in Bacillus subtilis

    Science.gov (United States)

    Nicolas, Pierre; Repoila, Francis; Bardowski, Jacek; Aymerich, Stéphane

    2017-01-01

    In eukaryotes, RNA species originating from pervasive transcription are regulators of various cellular processes, from the expression of individual genes to the control of cellular development and oncogenesis. In prokaryotes, the function of pervasive transcription and its output on cell physiology is still unknown. Most bacteria possess termination factor Rho, which represses pervasive, mostly antisense, transcription. Here, we investigate the biological significance of Rho-controlled transcription in the Gram-positive model bacterium Bacillus subtilis. Rho inactivation strongly affected gene expression in B. subtilis, as assessed by transcriptome and proteome analysis of a rho–null mutant during exponential growth in rich medium. Subsequent physiological analyses demonstrated that a considerable part of Rho-controlled transcription is connected to balanced regulation of three mutually exclusive differentiation programs: cell motility, biofilm formation, and sporulation. In the absence of Rho, several up-regulated sense and antisense transcripts affect key structural and regulatory elements of these differentiation programs, thereby suppressing motility and biofilm formation and stimulating sporulation. We dissected how Rho is involved in the activity of the cell fate decision-making network, centered on the master regulator Spo0A. We also revealed a novel regulatory mechanism of Spo0A activation through Rho-dependent intragenic transcription termination of the protein kinase kinB gene. Altogether, our findings indicate that distinct Rho-controlled transcripts are functional and constitute a previously unknown built-in module for the control of cell differentiation in B. subtilis. In a broader context, our results highlight the recruitment of the termination factor Rho, for which the conserved biological role is probably to repress pervasive transcription, in highly integrated, bacterium-specific, regulatory networks. PMID:28723971

  9. Histone acetyltransferase inhibitors antagonize AMP-activated protein kinase in postmortem glycolysis

    Directory of Open Access Journals (Sweden)

    Qiong Li

    2017-06-01

    Full Text Available Objective The purpose of this study was to investigate the influence of AMP-activated protein kinase (AMPK activation on protein acetylation and glycolysis in postmortem muscle to better understand the mechanism by which AMPK regulates postmortem glycolysis and meat quality. Methods A total of 32 mice were randomly assigned to four groups and intraperitoneally injected with 5-Aminoimidazole-4-carboxamide1-β-D-ribofuranoside (AICAR, a specific activator of AMPK, AICAR and histone acetyltransferase inhibitor II, or AICAR, Trichostatin A (TSA, an inhibitor of histone deacetylase I and II and Nicotinamide (NAM, an inhibitor of the Sirt family deacetylases. After mice were euthanized, the Longissimus dorsi muscle was collected at 0 h, 45 min, and 24 h postmortem. AMPK activity, protein acetylation and glycolysis in postmortem muscle were measured. Results Activation of AMPK by AICAR significantly increased glycolysis in postmortem muscle. At the same time, it increased the total acetylated proteins in muscle 45 min postmortem. Inhibition of protein acetylation by histone acetyltransferase inhibitors reduced AMPK activation induced increase in the total acetylated proteins and glycolytic rate in muscle early postmortem, while histone deacetylase inhibitors further promoted protein acetylation and glycolysis. Several bands of proteins were detected to be differentially acetylated in muscle with different glycolytic rates. Conclusion Protein acetylation plays an important regulatory role in postmortem glycolysis. As AMPK mediates the effects of pre-slaughter stress on postmortem glycolysis, protein acetylation is likely a mechanism by which antemortem stress influenced postmortem metabolism and meat quality though the exact mechanism is to be elucidated.

  10. The phosphoinositide 3-kinase α selective inhibitor BYL719 enhances the effect of the protein kinase C inhibitor AEB071 in GNAQ/GNA11-mutant uveal melanoma cells.

    Science.gov (United States)

    Musi, Elgilda; Ambrosini, Grazia; de Stanchina, Elisa; Schwartz, Gary K

    2014-05-01

    G-protein mutations are one of the most common mutations occurring in uveal melanoma activating the protein kinase C (PKC)/mitogen-activated protein kinase and phosphoinositide 3-kinase (PI3K)/AKT pathways. In this study, we described the effect of dual pathway inhibition in uveal melanoma harboring GNAQ and GNA11 mutations via PKC inhibition with AEB071 (sotrastaurin) and PI3K/AKT inhibition with BYL719, a selective PI3Kα inhibitor. Growth inhibition was observed in GNAQ/GNA11-mutant cells with AEB071 versus no activity in wild-type cells. In the GNAQ-mutant cells, AEB071 decreased phosphorylation of myristoylated alanine-rich C-kinase substrate, a substrate of PKC, along with ERK1/2 and ribosomal S6, but persistent AKT activation was present. BYL719 had minimal antiproliferative activity in all uveal melanoma cell lines, and inhibited phosphorylation of AKT in most cell lines. In the GNA11-mutant cell line, similar effects were observed with ERK1/2 inhibition, mostly inhibited by BYL719. With the combination treatment, both GNAQ- and GNA11-mutant cell lines showed synergistic inhibition of cell proliferation and apoptotic cell death. In vivo studies correlated with in vitro findings showing reduced xenograft tumor growth with the combination therapy in a GNAQ-mutant model. These findings suggest a new therapy treatment option for G-protein-mutant uveal melanoma with a focus on specific targeting of multiple downstream pathways as part of combination therapy.

  11. Development of new mouse lung tumor models expressing EGFR T790M mutants associated with clinical resistance to kinase inhibitors.

    Science.gov (United States)

    Regales, Lucia; Balak, Marissa N; Gong, Yixuan; Politi, Katerina; Sawai, Ayana; Le, Carl; Koutcher, Jason A; Solit, David B; Rosen, Neal; Zakowski, Maureen F; Pao, William

    2007-08-29

    The EGFR T790M mutation confers acquired resistance to kinase inhibitors in human EGFR mutant lung adenocarcinoma, is occasionally detected before treatment, and may confer genetic susceptibility to lung cancer. To study further its role in lung tumorigenesis, we developed mice with inducible expression in type II pneumocytes of EGFR(T790M) alone or together with a drug-sensitive L858R mutation. Both transgenic lines develop lung adenocarcinomas that require mutant EGFR for tumor maintenance but are resistant to an EGFR kinase inhibitor. EGFR(L858R+T790M)-driven tumors are transiently targeted by hsp90 inhibition. Notably, EGFR(T790M)-expressing animals develop tumors with longer latency than EGFR(L858R+T790M)-bearing mice and in the absence of additional kinase domain mutations. These new mouse models of mutant EGFR-dependent lung adenocarcinomas provide insight into clinical observations. The models should also be useful for developing improved therapies for patients with lung cancers harboring EGFR(T790M) alone or in conjunction with drug-sensitive EGFR kinase domain mutations.

  12. Development of new mouse lung tumor models expressing EGFR T790M mutants associated with clinical resistance to kinase inhibitors.

    Directory of Open Access Journals (Sweden)

    Lucia Regales

    2007-08-01

    Full Text Available The EGFR T790M mutation confers acquired resistance to kinase inhibitors in human EGFR mutant lung adenocarcinoma, is occasionally detected before treatment, and may confer genetic susceptibility to lung cancer.To study further its role in lung tumorigenesis, we developed mice with inducible expression in type II pneumocytes of EGFR(T790M alone or together with a drug-sensitive L858R mutation. Both transgenic lines develop lung adenocarcinomas that require mutant EGFR for tumor maintenance but are resistant to an EGFR kinase inhibitor. EGFR(L858R+T790M-driven tumors are transiently targeted by hsp90 inhibition. Notably, EGFR(T790M-expressing animals develop tumors with longer latency than EGFR(L858R+T790M-bearing mice and in the absence of additional kinase domain mutations.These new mouse models of mutant EGFR-dependent lung adenocarcinomas provide insight into clinical observations. The models should also be useful for developing improved therapies for patients with lung cancers harboring EGFR(T790M alone or in conjunction with drug-sensitive EGFR kinase domain mutations.

  13. Effects of kinase inhibitors and potassium phosphate (KPi) on site-specific phosphorylation of branched chain α-ketoacid dehydrogenase (BCKDH)

    International Nuclear Information System (INIS)

    Kuntz, M.J.; Shimomura, Y.; Ozawa, T.; Harris, R.A.

    1987-01-01

    BCKDH is phosphorylated by a copurifying kinase at two serine residues on the Elα subunit. Phosphorylation of both sites occurs at about the same rate initially, but inactivation is believed associated only with site 1 phosphorylation. The effects of KPi and known inhibitors of BCKDH kinase, α-chloroisocaproate (CIC) and branched chain α-ketoacids (BCKA), on the phosphorylation of purified rat liver BCKDH were studied. Site-specific phosphorylation was quantitated by thin-layer electrophoresis of tryptic peptides followed by densitometric scanning of autoradiograms. Addition of 5 mM KPi was found necessary to stabilize the BCKDH activity at 37 0 C. Increasing the KPi to 50 mM dramatically increased the CIC and BCKA inhibition of site 1 and site 2 phosphorylation. The finding of enhanced sensitivity of inhibitors with 50 mM KPi may facilitate identification of physiologically important kinase effectors. Regardless of the KPi concentration, CIC and the BCKA showed much more effective inhibition of site 2 than site 1 phosphorylation. Although site 1 is the primary inactivating site, predominant inhibition of site 2 phosphorylation may provide a means of modulating kinase/phosphatase control of BCKDH activity under steady state conditions

  14. Melanoma-associated antigen expression and the efficacy of tyrosine kinase inhibitors in head and neck cancer

    DEFF Research Database (Denmark)

    Hartmann, Stefan; Brands, Roman C; Küchler, Nora

    2015-01-01

    receptor (EGFR). The efficacy of tyrosine kinase inhibitors (TKI) in the context of melanoma-associated antigens is discussed in the present study. Five human squamous cell carcinoma cell lines were treated with the EGFR TKIs, erlotinib and gefitinib. The efficacy of these agents was measured using...

  15. The Link between Protein Kinase CK2 and Atypical Kinase Rio1

    Directory of Open Access Journals (Sweden)

    Konrad Kubiński

    2017-02-01

    Full Text Available The atypical kinase Rio1 is widespread in many organisms, ranging from Archaebacteria to humans, and is an essential factor in ribosome biogenesis. Little is known about the protein substrates of the enzyme and small-molecule inhibitors of the kinase. Protein kinase CK2 was the first interaction partner of Rio1, identified in yeast cells. The enzyme from various sources undergoes CK2-mediated phosphorylation at several sites and this modification regulates the activity of Rio1. The aim of this review is to present studies of the relationship between the two different kinases, with respect to CK2-mediated phosphorylation of Rio1, regulation of Rio1 activity, and similar susceptibility of the kinases to benzimidazole inhibitors.

  16. Silencing of RhoA and RhoC expression by RNA interference suppresses human colorectal carcinoma growth in vivo

    Directory of Open Access Journals (Sweden)

    Wang Haibo

    2010-09-01

    Full Text Available Abstract Background RhoA and RhoC have been proved to be over-expressed in many solid cancers, including colorectal cancer. The reduction of RhoA and RhoC expression by RNA interference (RNAi resulted growth inhibition of cancer cells. The present study was to evaluate the effect of silencing of RhoA and RhoC expression by RNAi on growth of human colorectal carcinoma (CRC in tumor-bearing nude mice in vivo. Methods To establish HCT116 cell transplantable model, the nude mice were subcutaneously inoculated with 1.0 × 107 HCT116 cells and kept growing till the tumor xenografts reached 5-7 mm in diameter. Then the mice were randomly assigned to three groups(seven mice in each group: (1 normal saline(NS group, (2replication-defective recombinant adenovirus carrying the negative control shRNA (Ad-HK group and (3replication-defective recombinant adenovirus carrying the 4-tandem linked RhoA and RhoC shRNAs (Ad-RhoA-RhoC group. Ad-HK (4 × 108 pfu, 30 ul/mouse, Ad-RhoA-RhoC (4 × 108 pfu, 30 ul/mouse or PBS (30 ul/mouse was injected intratumorally four times once every other day. The weight and volumes of tumor xenografts were recorded. The levels of RhoA and RhoC mRNA transcripts and proteins in tumor xenografts were detected by reverse quantitative transcription polymerase chain reaction (QRT-PCR and immunohistochemical staining respectively. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL assay was used to detect the death of cells. Results The xenografts in mice could be seen at 5th day from the implantation of HCT116 cells and all had reached 5-7 mm in size at 9th day. After injection intratumorally, the growth speed of tumor xenografts in Ad-RhoA-RhoC group was significantly delayed compared with those in NS and Ad-HK group(P RhoA and RhoC reduced more in Ad-RhoA-RhoC group than those in NS and Ad-HK group. The relative RhoA and RhoC mRNA transcripts were decreased to 48% and 43% respectively (P RhoA and Rho

  17. ROCK and RHO Playlist for Preimplantation Development: Streaming to HIPPO Pathway and Apicobasal Polarity in the First Cell Differentiation.

    Science.gov (United States)

    Alarcon, Vernadeth B; Marikawa, Yusuke

    2018-01-01

    In placental mammalian development, the first cell differentiation produces two distinct lineages that emerge according to their position within the embryo: the trophectoderm (TE, placenta precursor) differentiates in the surface, while the inner cell mass (ICM, fetal body precursor) forms inside. Here, we discuss how such position-dependent lineage specifications are regulated by the RHOA subfamily of small GTPases and RHO-associated coiled-coil kinases (ROCK). Recent studies in mouse show that activities of RHO/ROCK are required to promote TE differentiation and to concomitantly suppress ICM formation. RHO/ROCK operate through the HIPPO signaling pathway, whose cell position-specific modulation is central to establishing unique gene expression profiles that confer cell fate. In particular, activities of RHO/ROCK are essential in outside cells to promote nuclear localization of transcriptional co-activators YAP/TAZ, the downstream effectors of HIPPO signaling. Nuclear localization of YAP/TAZ depends on the formation of apicobasal polarity in outside cells, which requires activities of RHO/ROCK. We propose models of how RHO/ROCK regulate lineage specification and lay out challenges for future investigations to deepen our understanding of the roles of RHO/ROCK in preimplantation development. Finally, as RHO/ROCK may be inhibited by certain pharmacological agents, we discuss their potential impact on human preimplantation development in relation to fertility preservation in women.

  18. Amaryllidaceae Alkaloids as Potential Glycogen Synthase Kinase-3β Inhibitors

    Directory of Open Access Journals (Sweden)

    Daniela Hulcová

    2018-03-01

    Full Text Available Glycogen synthase kinase-3β (GSK-3β is a multifunctional serine/threonine protein kinase that was originally identified as an enzyme involved in the control of glycogen metabolism. It plays a key role in diverse physiological processes including metabolism, the cell cycle, and gene expression by regulating a wide variety of well-known substances like glycogen synthase, tau-protein, and β-catenin. Recent studies have identified GSK-3β as a potential therapeutic target in Alzheimer´s disease, bipolar disorder, stroke, more than 15 types of cancer, and diabetes. GSK-3β is one of the most attractive targets for medicinal chemists in the discovery, design, and synthesis of new selective potent inhibitors. In the current study, twenty-eight Amaryllidaceae alkaloids of various structural types were studied for their potency to inhibit GSK-3β. Promising results have been demonstrated by alkaloids of the homolycorine-{9-O-demethylhomolycorine (IC50 = 30.00 ± 0.71 µM, masonine (IC50 = 27.81 ± 0.01 μM}, and lycorine-types {caranine (IC50 = 30.75 ± 0.04 μM}.

  19. Phosphoryl transfer is not rate-limiting for the ROCK I-catalyzed kinase reaction.

    Science.gov (United States)

    Futer, Olga; Saadat, Ahmad R; Doran, John D; Raybuck, Scott A; Pazhanisamy, S

    2006-06-27

    Rho-associated coiled-coil kinase, ROCK, is implicated in Rho-mediated cell adhesion and smooth muscle contraction. Animal models suggest that the inhibition of ROCK can ameliorate conditions, such as vasospasm, hypertension, and inflammation. As part of our effort to design novel inhibitors of ROCK, we investigated the kinetic mechanism of ROCK I. Steady-state bisubstrate kinetics, inhibition kinetics, isotope partition analysis, viscosity effects, and presteady-state kinetics were used to explore the kinetic mechanism. Plots of reciprocals of initial rates obtained in the presence of nonhydrolyzable ATP analogues and the small molecule inhibitor of ROCK, Y-27632, against the reciprocals of the peptide concentrations yielded parallel lines (uncompetitive pattern). This pattern is indicative of an ordered binding mechanism, with the peptide adding first. The staurosporine analogue K252a, however, gave a noncompetitive pattern. When a pulse of (33)P-gamma-ATP mixed with ROCK was chased with excess unlabeled ATP and peptide, 0.66 enzyme equivalent of (33)P-phosphate was incorporated into the product in the first turnover. The presence of ATPase activity coupled with the isotope partition data is a clear evidence for the existence of a viable [E-ATP] complex in the kinase reaction and implicates a random binding mechanism. The k(cat)/K(m) parameters were fully sensitive to viscosity (viscosity effects of 1.4 +/- 0.2 and 0.9 +/- 0.3 for ATP and peptide 5, respectively), and therefore, the barriers to dissociation of either substrate are higher than the barrier for the phosphoryl transfer step. As a consequence, not all the binding steps are at fast equilibrium. The observation of a burst in presteady-state kinetics (k(b) = 10.2 +/- 2.1 s(-)(1)) and the viscosity effect on k(cat) of 1.3 +/- 0.2 characterize the phosphoryl transfer step to be fast and the release of product and/or the enzyme isomerization step accompanying it as rate-limiting at V(max) conditions. From

  20. Novel Small Molecule Inhibitors of Choline Kinase Identified by Fragment-Based Drug Discovery.

    Science.gov (United States)

    Zech, Stephan G; Kohlmann, Anna; Zhou, Tianjun; Li, Feng; Squillace, Rachel M; Parillon, Lois E; Greenfield, Matthew T; Miller, David P; Qi, Jiwei; Thomas, R Mathew; Wang, Yihan; Xu, Yongjin; Miret, Juan J; Shakespeare, William C; Zhu, Xiaotian; Dalgarno, David C

    2016-01-28

    Choline kinase α (ChoKα) is an enzyme involved in the synthesis of phospholipids and thereby plays key roles in regulation of cell proliferation, oncogenic transformation, and human carcinogenesis. Since several inhibitors of ChoKα display antiproliferative activity in both cellular and animal models, this novel oncogene has recently gained interest as a promising small molecule target for cancer therapy. Here we summarize our efforts to further validate ChoKα as an oncogenic target and explore the activity of novel small molecule inhibitors of ChoKα. Starting from weakly binding fragments, we describe a structure based lead discovery approach, which resulted in novel highly potent inhibitors of ChoKα. In cancer cell lines, our lead compounds exhibit a dose-dependent decrease of phosphocholine, inhibition of cell growth, and induction of apoptosis at low micromolar concentrations. The druglike lead series presented here is optimizable for improvements in cellular potency, drug target residence time, and pharmacokinetic parameters. These inhibitors may be utilized not only to further validate ChoKα as antioncogenic target but also as novel chemical matter that may lead to antitumor agents that specifically interfere with cancer cell metabolism.

  1. RhoA/ROCK pathway is the major molecular determinant of basal tone in intact human internal anal sphincter.

    Science.gov (United States)

    Rattan, Satish; Singh, Jagmohan

    2012-04-01

    The knowledge of molecular control mechanisms underlying the basal tone in the intact human internal anal sphincter (IAS) is critical for the pathophysiology and rational therapy for a number of debilitating rectoanal motility disorders. We determined the role of RhoA/ROCK and PKC pathways by comparing the effects of ROCK- and PKC-selective inhibitors Y 27632 and Gö 6850 (10(-8) to 10(-4) M), respectively, on the basal tone in the IAS vs. the rectal smooth muscle (RSM). Western blot studies were performed to determine the levels of RhoA/ROCK II, PKC-α, MYPT1, CPI-17, and MLC(20) in the unphosphorylated and phosphorylated forms, in the IAS vs. RSM. Confocal microscopic studies validated the membrane distribution of ROCK II. Finally, to confirm a direct relationship, we examined the enzymatic activities and changes in the basal IAS tone and p-MYPT1, p-CPI-17, and p-MLC(20), before and after Y 27632 and Gö 6850. Data show higher levels of RhoA/ROCK II and related downstream signal transduction proteins in the IAS vs. RSM. In addition, data show a significant correlation between the active RhoA/ROCK levels, ROCK enzymatic activity, downstream proteins, and basal IAS tone, before and after ROCK inhibitor. From these data we conclude 1) RhoA/ROCK and downstream signaling are constitutively active in the IAS, and this pathway (in contrast with PKC) is the critical determinant of the basal tone in intact human IAS; and 2) RhoA and ROCK are potential therapeutic targets for a number of rectoanal motility disorders for which currently there is no satisfactory treatment.

  2. Small tyrosine kinase inhibitors interrupt EGFR signaling by interacting with erbB3 and erbB4 in glioblastoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco-Garcia, Estefania; Saceda, Miguel [Instituto de Biologia Molecular y Celular, Universidad Miguel Hernandez, 03202 Elche (Alicante) (Spain); Unidad de Investigacion, Hospital General Universitario de Elche, 03203 Elche (Alicante) (Spain); Grasso, Silvina; Rocamora-Reverte, Lourdes; Conde, Mariano; Gomez-Martinez, Angeles [Instituto de Biologia Molecular y Celular, Universidad Miguel Hernandez, 03202 Elche (Alicante) (Spain); Garcia-Morales, Pilar [Instituto de Biologia Molecular y Celular, Universidad Miguel Hernandez, 03202 Elche (Alicante) (Spain); Unidad de Investigacion, Hospital General Universitario de Elche, 03203 Elche (Alicante) (Spain); Ferragut, Jose A. [Instituto de Biologia Molecular y Celular, Universidad Miguel Hernandez, 03202 Elche (Alicante) (Spain); Martinez-Lacaci, Isabel, E-mail: imlacaci@umh.es [Instituto de Biologia Molecular y Celular, Universidad Miguel Hernandez, 03202 Elche (Alicante) (Spain); Unidad AECC de Investigacion Traslacional en Cancer, Hospital Universitario Virgen de la Arrixaca, 30120 Murcia (Spain)

    2011-06-10

    Signaling through the epidermal growth factor receptor (EGFR) is relevant in glioblastoma. We have determined the effects of the EGFR inhibitor AG1478 in glioblastoma cell lines and found that U87 and LN-229 cells were very sensitive to this drug, since their proliferation diminished and underwent a marked G{sub 1} arrest. T98 cells were a little more refractory to growth inhibition and A172 cells did not undergo a G{sub 1} arrest. This G{sub 1} arrest was associated with up-regulation of p27{sup kip1}, whose protein turnover was stabilized. EGFR autophosphorylation was blocked with AG1478 to the same extent in all the cell lines. Other small-molecule EGFR tyrosine kinase inhibitors employed in the clinic, such as gefitinib, erlotinib and lapatinib, were able to abrogate proliferation of glioblastoma cell lines, which underwent a G{sub 1} arrest. However, the EGFR monoclonal antibody, cetuximab had no effect on cell proliferation and consistently, had no effect on cell cycle either. Similarly, cetuximab did not inhibit proliferation of U87 {Delta}EGFR cells or primary glioblastoma cell cultures, whereas small-molecule EGFR inhibitors did. Activity of downstream signaling molecules of EGFR such as Akt and especially ERK1/2 was interrupted with EGFR tyrosine kinase inhibitors, whereas cetuximab treatment could not sustain this blockade over time. Small-molecule EGFR inhibitors were able to prevent phosphorylation of erbB3 and erbB4, whereas cetuximab only hindered EGFR phosphorylation, suggesting that EGFR tyrosine kinase inhibitors may mediate their anti-proliferative effects through other erbB family members. We can conclude that small-molecule EGFR inhibitors may be a therapeutic approach for the treatment of glioblastoma patients.

  3. Design and synthesis of imidazopyridine analogues as inhibitors of phosphoinositide 3-kinase signaling and angiogenesis.

    Science.gov (United States)

    Kim, Okseon; Jeong, Yujeong; Lee, Hyunseung; Hong, Sun-Sun; Hong, Sungwoo

    2011-04-14

    Phosphatidylinositol 3-kinase α (PI3Kα) is an important regulator of intracellular signaling pathways, controlling remarkably diverse arrays of physiological processes. Because the PI3K pathway is frequently up-regulated in human cancers, the inhibition of PI3Kα can be a promising approach to cancer therapy. In this study, we have designed and synthesized a new series of imidazo[1,2-a]pyridine derivatives as PI3Kα inhibitors through the fragment-growing strategy. By varying groups at the 3- and 6-positions of imidazo[1,2-a]pyridines, we studied the structure-activity relationships (SAR) profiles and identified a series of potent PI3Kα inhibitors. Representative derivatives showed good activity in cellular proliferation and apoptosis assays. Moreover, these inhibitors exhibited noteworthy antiangiogenic activity.

  4. How tyrosine kinase inhibitors impair metabolism and endocrine system function: a systematic updated review.

    Science.gov (United States)

    Breccia, Massimo; Molica, Matteo; Alimena, Giuliana

    2014-12-01

    Tyrosine kinase inhibitors (TKIs) advent has deeply changed the outcome of chronic myeloid leukemia (CML) patients, with improved rates of response and overall survival. However, for this success some patients paid the price of a number of peculiar side effects, the so-called off-target side effects, specific for each one TKI. These effects are due to non-selective inhibition of other tyrosine kinase receptors, such as PDGFR, c-KIT, Src, VEGF. Consequences of this inhibition, some metabolic changes during the treatment with TKIs are reported. Aim of present review is to report metabolic changes and potential mechanisms involved in the pathogenesis related to imatinib, second (nilotinib and dasatinib) and third generation (bosutinib and ponatinib) TKIs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Antiproliferative activity of olomoucine II, a novel 2,6,9-trisubstituted purine cyclin-dependent kinase inhibitor

    Czech Academy of Sciences Publication Activity Database

    Kryštof, Vladimír; McNae, I. W.; Walkinshaw, M. D.; Fischer, P.M.; Müller, P.; Vojtešek, B.; Orság, Martin; Havlíček, Libor; Strnad, Miroslav

    2005-01-01

    Roč. 62, č. 15 (2005), s. 1763-1771 ISSN 1420-682X R&D Projects: GA ČR GP204/03/D231 Institutional research plan: CEZ:AV0Z50380511 Keywords : olomoucine II * roscovitine * cyclin-dependent kinase inhibitor Subject RIV: CE - Biochemistry Impact factor: 4.582, year: 2005

  6. Exchange mechanisms for $\\pi^{-}p\\rightarrow\\rho^{0}$n and $\\rho-\\omega$ interference

    CERN Document Server

    Estabrooks, P G; Michael, C

    1974-01-01

    The 17 GeV/c pi /sup -/p to rho /sup 0/n production amplitudes are decomposed into pi , A/sub 2/ and non-evasive exchange contributions. Independent support for this description comes from the observed rho - omega interference effects and from the energy dependence of rho /sup 0/ production data. (18 refs).

  7. The orally active and bioavailable ATR kinase inhibitor AZD6738 potentiates the anti-tumor effects of cisplatin to resolve ATM-deficient non-small cell lung cancer in vivo.

    Science.gov (United States)

    Vendetti, Frank P; Lau, Alan; Schamus, Sandra; Conrads, Thomas P; O'Connor, Mark J; Bakkenist, Christopher J

    2015-12-29

    ATR and ATM are DNA damage signaling kinases that phosphorylate several thousand substrates. ATR kinase activity is increased at damaged replication forks and resected DNA double-strand breaks (DSBs). ATM kinase activity is increased at DSBs. ATM has been widely studied since ataxia telangiectasia individuals who express no ATM protein are the most radiosensitive patients identified. Since ATM is not an essential protein, it is widely believed that ATM kinase inhibitors will be well-tolerated in the clinic. ATR has been widely studied, but advances have been complicated by the finding that ATR is an essential protein and it is widely believed that ATR kinase inhibitors will be toxic in the clinic. We describe AZD6738, an orally active and bioavailable ATR kinase inhibitor. AZD6738 induces cell death and senescence in non-small cell lung cancer (NSCLC) cell lines. AZD6738 potentiates the cytotoxicity of cisplatin and gemcitabine in NSCLC cell lines with intact ATM kinase signaling, and potently synergizes with cisplatin in ATM-deficient NSCLC cells. In contrast to expectations, daily administration of AZD6738 and ATR kinase inhibition for 14 consecutive days is tolerated in mice and enhances the therapeutic efficacy of cisplatin in xenograft models. Remarkably, the combination of cisplatin and AZD6738 resolves ATM-deficient lung cancer xenografts.

  8. Molecular characterization of c-Abl/c-Src kinase inhibitors targeted against murine tumour progenitor cells that express stem cell markers.

    Directory of Open Access Journals (Sweden)

    Thomas Kruewel

    Full Text Available BACKGROUND: The non-receptor tyrosine kinases c-Abl and c-Src are overexpressed in various solid human tumours. Inhibition of their hyperactivity represents a molecular rationale in the combat of cancerous diseases. Here we examined the effects of a new family of pyrazolo [3,4-d] pyrimidines on a panel of 11 different murine lung tumour progenitor cell lines, that express stem cell markers, as well as on the human lung adenocarcinoma cell line A549, the human hepatoma cell line HepG2 and the human colon cancer cell line CaCo2 to obtain insight into the mode of action of these experimental drugs. METHODOLOGY/PRINCIPAL FINDINGS: Treatment with the dual kinase inhibitors blocked c-Abl and c-Src kinase activity efficiently in the nanomolar range, induced apoptosis, reduced cell viability and caused cell cycle arrest predominantly at G0/G1 phase while western blot analysis confirmed repressed protein expression of c-Abl and c-Src as well as the interacting partners p38 mitogen activated protein kinase, heterogenous ribonucleoprotein K, cyclin dependent kinase 1 and further proteins that are crucial for tumour progression. Importantly, a significant repression of the epidermal growth factor receptor was observed while whole genome gene expression analysis evidenced regulation of many cell cycle regulated genes as well integrin and focal adhesion kinase (FAK signalling to impact cytoskeleton dynamics, migration, invasion and metastasis. CONCLUSIONS/SIGNIFICANCE: Our experiments and recently published in vivo engraftment studies with various tumour cell lines revealed the dual kinase inhibitors to be efficient in their antitumour activity.

  9. The Src family kinase inhibitor dasatinib delays pain-related behaviour and conserves bone in a rat model of cancer-induced bone pain

    DEFF Research Database (Denmark)

    Appel, Camilla Kristine; Gallego-Pedersen, Simone; Andersen, Line

    2017-01-01

    -induced bone pain, including cancer growth, osteoclastic bone degradation and nociceptive signalling. Here we investigate the role of dasatinib, an oral Src kinase family and Bcr-Abl tyrosine kinase inhibitor, in an animal model of cancer-induced bone pain. Daily administration of dasatinib (15 mg/kg, p...

  10. Increased rho kinase activity in mononuclear cells of dialysis and stage 3-4 chronic kidney disease patients with left ventricular hypertrophy: Cardiovascular risk implications.

    Science.gov (United States)

    Calò, Lorenzo A; Vertolli, Ugo; Pagnin, Elisa; Ravarotto, Verdiana; Davis, Paul A; Lupia, Mario; Naso, Elena; Maiolino, Giuseppe; Naso, Agostino

    2016-03-01

    Cardiovascular disease (CVD) is the leading cause of excess mortality in chronic kidney disease (CKD) and dialysis patients (DP) who have higher prevalence of left ventricular hypertrophy (LVH), the strongest predictor of CV events. Rho kinase (ROCK) activation is linked in hypertensive patients to cardiac remodeling while ROCK inhibition suppresses cardiomyocyte hypertrophy and, in a human clinical condition opposite to hypertension, its downregulation associates with lack of CV remodeling. Information on ROCK activation-LVH link in CKD and DP is lacking. Mononuclear cells (PBMCs) MYPT-1 phosphorylation, a marker of ROCK activity, and the effect of fasudil, a ROCK inhibitor, on MYPT-1 phosphorylation were assessed in 23 DPs, 13 stage 3-4 CKD and 36 healthy subjects (HS) by Western blot. LV mass was assessed by M-mode echocardiography. DP and CKD had higher MYPT-1 phosphorylation compared to HS (p<0.001 and p=0.003). Fasudil (500 and 1000μM) dose dependently reduced MYPT-1 phosphorylation in DP (p<0.01). DP had higher LV mass than CKD (p<0.001). MYPT-1 phosphorylation was higher in patients with LVH (p=0.009) and correlated with LV mass both in DP and CKD with LVH (p<0.001 and p=0.006). In DP and CKD, ROCK activity tracks with LVH. This ROCK activation-LVH link provided in these CVD high-risk patients along with similar findings in hypertensive patients and added to opposite findings in a human model opposite to hypertension and in type 2 diabetic patients, identify ROCK activation as a potential LVH marker and provide further rationale for ROCK activation inhibition as target of therapy in CVD high-risk patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Navigating into the binding pockets of the HER family protein kinases: discovery of novel EGFR inhibitor as antitumor agent

    Directory of Open Access Journals (Sweden)

    Liu W

    2015-07-01

    Full Text Available Wei Liu,1,* Jin-Feng Ning,2,* Qing-Wei Meng,1 Jing Hu,1 Yan-Bin Zhao,1 Chao Liu,3 Li Cai11The Fourth Department of Medical Oncology, Harbin Medical University Cancer Hospital, 2The Thoracic Surgery Department, Harbin Medical University Cancer Hospital, Harbin, People’s Republic of China; 3General Surgery Department, Mudanjiang Guanliju Central Hospital, Mishan, Heilongjiang Province, People’s Republic of China*These authors contributed equally to this workAbstract: The epidermal growth factor receptor (EGFR family has been validated as a successful antitumor drug target for decades. Known EGFR inhibitors were exposed to distinct drug resistance against the various EGFR mutants within non-small-cell lung cancer (NSCLC, particularly the T790M mutation. Although so far a number of studies have been reported on the development of third-generation EGFR inhibitors for overcoming the resistance issue, the design procedure largely depends on the intuition of medicinal chemists. Here we retrospectively make a detailed analysis of the 42 EGFR family protein crystal complexes deposited in the Protein Data Bank (PDB. Based on the analysis of inhibitor binding modes in the kinase catalytic cleft, we identified a potent EGFR inhibitor (compound A-10 against drug-resistant EGFR through fragment-based drug design. This compound showed at least 30-fold more potency against EGFR T790M than the two control molecules erlotinib and gefitinib in vitro. Moreover, it could exhibit potent HER2 inhibitory activities as well as tumor growth inhibitory activity. Molecular docking studies revealed a structural basis for the increased potency and mutant selectivity of this compound. Compound A-10 may be selected as a promising candidate in further preclinical studies. In addition, our findings could provide a powerful strategy to identify novel selective kinase inhibitors on the basis of detailed kinase–ligand interaction space in the PDB.Keywords: EGFR, kinase

  12. Rho A Regulates Epidermal Growth Factor-Induced Human Osteosarcoma MG63 Cell Migration

    Directory of Open Access Journals (Sweden)

    Jinyang Wang

    2018-05-01

    Full Text Available Osteosarcoma, the most common primary bone tumor, occurs most frequently in children and adolescents and has a 5-year survival rate, which is unsatisfactory. As epidermal growth factor receptor (EGFR positively correlates with TNM (tumor-node-metastasis stage in osteosarcoma, EGFR may play an important role in its progression. The purpose of this study was to explore potential mechanisms underlying this correlation. We found that EGF promotes MG63 cell migration and invasion as well as stress fiber formation via Rho A activation and that these effects can be reversed by inhibiting Rho A expression. In addition, molecules downstream of Rho A, including ROCK1, LIMK2, and Cofilin, are activated by EGF in MG63 cells, leading to actin stress fiber formation and cell migration. Moreover, inhibition of ROCK1, LIMK2, or Cofilin in MG63 cells using known inhibitors or short hairpin RNA (shRNA prevents actin stress fiber formation and cell migration. Thus, we conclude that Rho A/ROCK1/LIMK2/Cofilin signaling mediates actin microfilament formation in MG63 cells upon EGFR activation. This novel pathway provides a promising target for preventing osteosarcoma progression and for treating this cancer.

  13. Convergent Akt activation drives acquired EGFR inhibitor resistance in lung cancer

    DEFF Research Database (Denmark)

    Jacobsen, Kirstine; Bertran-Alamillo, Jordi; Molina, Miguel Angel

    2017-01-01

    Non-small-cell lung cancer patients with activating epidermal growth factor receptor (EGFR) mutations typically benefit from EGFR tyrosine kinase inhibitor treatment. However, virtually all patients succumb to acquired EGFR tyrosine kinase inhibitor resistance that occurs via diverse mechanisms....... The diversity and unpredictability of EGFR tyrosine kinase inhibitor resistance mechanisms presents a challenge for developing new treatments to overcome EGFR tyrosine kinase inhibitor resistance. Here, we show that Akt activation is a convergent feature of acquired EGFR tyrosine kinase inhibitor resistance......, across a spectrum of diverse, established upstream resistance mechanisms. Combined treatment with an EGFR tyrosine kinase inhibitor and Akt inhibitor causes apoptosis and synergistic growth inhibition in multiple EGFR tyrosine kinase inhibitor-resistant non-small-cell lung cancer models. Moreover...

  14. Fibroblast activation protein (FAP is essential for the migration of bone marrow mesenchymal stem cells through RhoA activation.

    Directory of Open Access Journals (Sweden)

    Kuei-Min Chung

    Full Text Available BACKGROUND: The ability of human bone marrow mesenchymal stem cells (BM-MSCs to migrate and localize specifically to injured tissues is central in developing therapeutic strategies for tissue repair and regeneration. Fibroblast activation protein (FAP is a cell surface serine protease expressed at sites of tissue remodeling during embryonic development. It is also expressed in BM-MSCs, but not in normal tissues or cells. The function of FAP in BM-MSCs is not known. PRINCIPAL FINDINGS: We found that depletion of FAP proteins significantly inhibited the migration of BM-MSCs in a transwell chemotaxis assay. Such impaired migration ability of BM-MSCs could be rescued by re-expressing FAP in these cells. We then demonstrated that depletion of FAP activated intracellular RhoA GTPase. Consistently, inhibition of RhoA activity using a RhoA inhibitor rescued its migration ability. Inhibition of FAP activity with an FAP-specific inhibitor did not affect the activation of RhoA or the migration of BM-MSCs. Furthermore, the inflammatory cytokines interleukin-1beta (IL-1β and transforming growth factor-beta (TGF-β upregulated FAP expression, which coincided with better BM-MSC migration. CONCLUSIONS: Our results indicate FAP plays an important role in the migration of BM-MSCs through modulation of RhoA GTPase activity. The peptidase activity of FAP is not essential for such migration. Cytokines IL-1β and TGF-β upregulate the expression level of FAP and thus enhance BM-MSC migration.

  15. The atypical Rho GTPase RhoD is a regulator of actin cytoskeleton dynamics and directed cell migration

    Energy Technology Data Exchange (ETDEWEB)

    Blom, Magdalena; Reis, Katarina [Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm (Sweden); Heldin, Johan [Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala SE-751 22 Uppsala (Sweden); Kreuger, Johan [Department of Medical Cell Biology, Science for Life Laboratory, Uppsala University, SE-751 23 Uppsala (Sweden); Aspenström, Pontus, E-mail: pontus.aspenstrom@ki.se [Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm (Sweden)

    2017-03-15

    RhoD belongs to the Rho GTPases, a protein family responsible for the regulation and organization of the actin cytoskeleton, and, consequently, many cellular processes like cell migration, cell division and vesicle trafficking. Here, we demonstrate that the actin cytoskeleton is dynamically regulated by increased or decreased protein levels of RhoD. Ectopic expression of RhoD has previously been shown to give an intertwined weave of actin filaments. We show that this RhoD-dependent effect is detected in several cell types and results in a less dynamic actin filament system. In contrast, RhoD depletion leads to increased actin filament-containing structures, such as cortical actin, stress fibers and edge ruffles. Moreover, vital cellular functions such as cell migration and proliferation are defective when RhoD is silenced. Taken together, we present data suggesting that RhoD is an important component in the control of actin dynamics and directed cell migration. - Highlights: • Increased RhoD expression leads to loss of actin structures, e.g. stress fibers and gives rise to decreased actin dynamics. • RhoD knockdown induces various actin-containing structures such as edge ruffles, stress fibers and cortical actin, in a cell-type specific manner. • RhoD induces specific actin rearrangements depending on its subcellular localization. • RhoD knockdown has effects on cellular processes, such as directed cell migration and proliferation.

  16. The atypical Rho GTPase RhoD is a regulator of actin cytoskeleton dynamics and directed cell migration

    International Nuclear Information System (INIS)

    Blom, Magdalena; Reis, Katarina; Heldin, Johan; Kreuger, Johan; Aspenström, Pontus

    2017-01-01

    RhoD belongs to the Rho GTPases, a protein family responsible for the regulation and organization of the actin cytoskeleton, and, consequently, many cellular processes like cell migration, cell division and vesicle trafficking. Here, we demonstrate that the actin cytoskeleton is dynamically regulated by increased or decreased protein levels of RhoD. Ectopic expression of RhoD has previously been shown to give an intertwined weave of actin filaments. We show that this RhoD-dependent effect is detected in several cell types and results in a less dynamic actin filament system. In contrast, RhoD depletion leads to increased actin filament-containing structures, such as cortical actin, stress fibers and edge ruffles. Moreover, vital cellular functions such as cell migration and proliferation are defective when RhoD is silenced. Taken together, we present data suggesting that RhoD is an important component in the control of actin dynamics and directed cell migration. - Highlights: • Increased RhoD expression leads to loss of actin structures, e.g. stress fibers and gives rise to decreased actin dynamics. • RhoD knockdown induces various actin-containing structures such as edge ruffles, stress fibers and cortical actin, in a cell-type specific manner. • RhoD induces specific actin rearrangements depending on its subcellular localization. • RhoD knockdown has effects on cellular processes, such as directed cell migration and proliferation.

  17. Preclinical FLT-PET and FDG-PET imaging of tumor response to the multi-targeted Aurora B kinase inhibitor, TAK-901

    International Nuclear Information System (INIS)

    Cullinane, Carleen; Waldeck, Kelly L.; Binns, David; Bogatyreva, Ekaterina; Bradley, Daniel P.; Jong, Ron de; McArthur, Grant A.; Hicks, Rodney J.

    2014-01-01

    Introduction: The Aurora kinases play a key role in mitosis and have recently been identified as attractive targets for therapeutic intervention in cancer. The aim of this study was therefore to investigate the utility of 3′-[ 18 F]fluoro-3′-deoxythymidine (FLT) and 2-deoxy-2-[ 18 F]fluoro-D-glucose (FDG) for assessment of tumor response to the multi-targeted Aurora B kinase inhibitor, TAK-901. Methods: Balb/c nude mice bearing HCT116 colorectal xenografts were treated with up to 30 mg/kg TAK 901 or vehicle intravenously twice daily for two days on a weekly cycle. Tumor growth was monitored by calliper measurements and PET imaging was performed at baseline, day 4, 8, 11 and 15. Tumors were harvested at time points corresponding to days of PET imaging for analysis of ex vivo markers of cell proliferation and metabolism together with markers of Aurora B kinase inhibition including phospho-histone H3 (pHH3) and senescence associated β-galactosidase. Results: Tumor growth was inhibited by 60% on day 12 of 30 mg/kg TAK-901 therapy. FLT uptake was significantly reduced by day 4 of treatment and this corresponded with reduction in bromodeoxyuridine and pHH3 staining by immunohistochemistry. All biomarkers rebounded towards baseline levels by the commencement of the next treatment cycle, consistent with release of Aurora B kinase suppression. TAK-901 therapy had no impact on glucose metabolism as assessed by FDG uptake and GLUT1 staining by immunohistochemistry. Conclusions: FLT-PET, but not FDG-PET, is a robust non-invasive imaging biomarker of early HCT116 tumor response to the on-target effects of the multi-targeted Aurora B kinase inhibitor, TAK-901. Advances in knowledge and implications for patient care: This is the first report to demonstrate the impact of the multi-targeted Aurora B kinase inhibitor, TAK-901 on tumor FLT uptake. The findings provide a strong rationale for the evaluation of FLT-PET as an early biomarker of tumor response in the early phase

  18. The Src family kinase inhibitor dasatinib delays pain-related behaviour and conserves bone in a rat model of cancer-induced bone pain

    DEFF Research Database (Denmark)

    Appel, Camilla Kristine; Gallego-Pedersen, Simone; Andersen, Line

    2017-01-01

    Pain is a severe and debilitating complication of metastatic bone cancer. Current analgesics do not provide sufficient pain relief for all patients, creating a great need for new treatment options. The Src kinase, a non-receptor protein tyrosine kinase, is implicated in processes involved in cancer......-induced bone pain, including cancer growth, osteoclastic bone degradation and nociceptive signalling. Here we investigate the role of dasatinib, an oral Src kinase family and Bcr-Abl tyrosine kinase inhibitor, in an animal model of cancer-induced bone pain. Daily administration of dasatinib (15 mg/kg, p...

  19. Acute lymphoid and gastrointestinal toxicity induced by selective p38alpha map kinase and map kinase-activated protein kinase-2 (MK2) inhibitors in the dog.

    Science.gov (United States)

    Morris, Dale L; O'Neil, Shawn P; Devraj, Rajesh V; Portanova, Joseph P; Gilles, Richard W; Gross, Cindy J; Curtiss, Sandra W; Komocsar, Wendy J; Garner, Debra S; Happa, Fernando A; Kraus, Lori J; Nikula, Kristen J; Monahan, Joseph B; Selness, Shaun R; Galluppi, Gerald R; Shevlin, Kimberly M; Kramer, Jeffrey A; Walker, John K; Messing, Dean M; Anderson, David R; Mourey, Robert J; Whiteley, Laurence O; Daniels, John S; Yang, Jerry Z; Rowlands, Philip C; Alden, Carl L; Davis, John W; Sagartz, John E

    2010-06-01

    Exposure to moderately selective p38alpha mitogen-activated protein kinase (MAPK) inhibitors in the Beagle dog results in an acute toxicity consisting of mild clinical signs (decreased activity, diarrhea, and fever), lymphoid necrosis and depletion in the gut-associated lymphoid tissue (GALT), mesenteric lymph nodes and spleen, and linear colonic and cecal mucosal hemorrhages. Lymphocyte apoptosis and necrosis in the GALT is the earliest and most prominent histopathologic change observed, followed temporally by neutrophilic infiltration and acute inflammation of the lymph nodes and spleen and multifocal mucosal epithelial necrosis and linear hemorrhages in the colon and cecum. These effects are not observed in the mouse, rat, or cynomolgus monkey. To further characterize the acute toxicity in the dog, a series of in vivo, in vitro, and immunohistochemical studies were conducted to determine the relationship between the lymphoid and gastrointestinal (GI) toxicity and p38 MAPK inhibition. Results of these studies demonstrate a direct correlation between p38alpha MAPK inhibition and the acute lymphoid and gastrointestinal toxicity in the dog. Similar effects were observed following exposure to inhibitors of MAPK-activated protein kinase-2 (MK2), further implicating the role of p38alpha MAPK signaling pathway inhibition in these effects. Based on these findings, the authors conclude that p38alpha MAPK inhibition results in acute lymphoid and GI toxicity in the dog and is unique among the species evaluated in these studies.

  20. QCD factorizations in {gamma}*{gamma}*->{rho}{sub L}{sup 0}{rho}{sub L}{sup 0}

    Energy Technology Data Exchange (ETDEWEB)

    Pire, B. [CPHT, Unite mixte 7644 du CNRS, Ecole Polytechnique, 91128 Palaiseau (France)]. E-mail: pire@cpht.polytechnique.fr; Segond, M. [LPT, Unite mixte 8627 du CNRS, Universite Paris-Sud, 91405 Orsay (France); Szymanowski, L. [LPT, Unite mixte 8627 du CNRS, Universite Paris-Sud, 91405 Orsay (France); Universite de Liege, B-4000 Liege (Belgium); Soltan Institute for Nuclear Studies, Hoza 69, 00-681 Warsaw (Poland); Wallon, S. [LPT, Unite mixte 8627 du CNRS. , Universite Paris-Sud, 91405 Orsay (France)

    2006-08-24

    We calculate the lowest order QCD amplitude, i.e. the quark exchange contribution, to the forward production amplitude of a pair of longitudinally polarized {rho} mesons in the scattering of two virtual photons {gamma}*(Q{sub 1}){gamma}*(Q{sub 2})->{rho}{sub L}{sup 0}{rho}{sub L}{sup 0}. We show that the scattering amplitude simultaneously factorizes in two quite different ways: the part with transverse photons is described by the QCD factorization formula involving the generalized distribution amplitude of two final {rho} mesons, whereas the part with longitudinally polarized photons takes the QCD factorized form with the {gamma}{sub L}*->{rho}{sub L}{sup 0} transition distribution amplitude. Perturbative expressions for these, in general, non-perturbative functions are obtained in terms of the {rho}-meson distribution amplitude.

  1. Small G proteins in insulin action: Rab and Rho families at the crossroads of signal transduction and GLUT4 vesicle traffic.

    Science.gov (United States)

    Ishikura, S; Koshkina, A; Klip, A

    2008-01-01

    Insulin stimulates glucose uptake into muscle and adipose tissues through glucose transporter 4 (GLUT4). GLUT4 cycles between the intracellular compartments and the plasma membrane. GLUT4 traffic-regulating insulin signals are largely within the insulin receptor-insulin receptor substrate-phosphatidylinositol 3-kinase (IR-IRS-PI3K) axis. In muscle cells, insulin signal bifurcates downstream of the PI3K into one arm leading to the activation of the Ser/Thr kinases Akt and atypical protein kinase C, and another leading to the activation of Rho family protein Rac1 leading to actin remodelling. Activated Akt inactivates AS160, a GTPase-activating protein for Rab family small G proteins. Here we review the roles of Rab and Rho proteins, particularly Rab substrates of AS160 and Rac1, in insulin-stimulated GLUT4 traffic. We discuss: (1) how distinct steps in GLUT4 traffic may be regulated by discrete Rab proteins, and (2) the importance of Rac1 activation in insulin-induced actin remodelling in muscle cells, a key element for the net gain in surface GLUT4.

  2. Design of inhibitors of thymidylate kinase from Variola virus as new selective drugs against smallpox.

    Science.gov (United States)

    Guimarães, Ana P; de Souza, Felipe R; Oliveira, Aline A; Gonçalves, Arlan S; de Alencastro, Ricardo B; Ramalho, Teodorico C; França, Tanos C C

    2015-02-16

    Recently we constructed a homology model of the enzyme thymidylate kinase from Variola virus (VarTMPK) and proposed it as a new target to the drug design against smallpox. In the present work, we used the antivirals cidofovir and acyclovir as reference compounds to choose eleven compounds as leads to the drug design of inhibitors for VarTMPK. Docking and molecular dynamics (MD) studies of the interactions of these compounds inside VarTMPK and human TMPK (HssTMPK) suggest that they compete for the binding region of the substrate and were used to propose the structures of ten new inhibitors for VarTMPK. Further docking and MD simulations of these compounds, inside VarTMPK and HssTMPK, suggest that nine among ten are potential selective inhibitors of VarTMPK. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  3. Effect and mechanism of evodiamine against ethanol-induced gastric ulcer in mice by suppressing Rho/NF-кB pathway.

    Science.gov (United States)

    Zhao, Zhongyan; Gong, Shilin; Wang, Shumin; Ma, Chunhua

    2015-09-01

    Evodiamine (EVD), a major alkaloid compound extracted from the dry unripened fruit Evodia fructus (Evodia rutaecarpa Benth., Rutaceae), has various pharmacological effects. The purpose of the present study was to investigate the possible anti-ulcerogenic potential of EVD and explore the underlying mechanism against ethanol-induced gastric ulcer in mice. Administration of EVD at the doses of 20, 40mg/kg body weight prior to the ethanol ingestion could effectively protect the stomach from ulceration. The gastric lesion was significantly ameliorated in the EVD group compared with that in the model group. Pre-treatment with EVD prevented the oxidative damage and decreased the levels of prostaglandin E2 (PGE2) content, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). In addition, EVD pretreatment markedly increased the serum levels of glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT), decreased malonaldehyde (MDA) content in serum and activity of myeloperoxidase (MPO) in stomach tissues compared with those in the model group. In the mechanistic study, significant elevation of Rho, Rho-kinase 1 (ROCK1), ROCK2, cytosolic and nucleic NF-κBp65 expressions were observed in the gastric mucosa group, whereas EVD effectively suppressed the protein expressions of Rho, Rho-kinase 1 (ROCK1), ROCK2, cytosolic and nucleic NF-κBp65 in mice. Moreover, EVD showed protective activity on ethanol-induced GES-1 cells, while the therapeutic effects were not due to its cytotoxity. Taken together, these results strongly indicated that EVD exerted a gastro-protective effect against gastric ulceration. The underlying mechanism might be associated with the improvement of antioxidant and anti-inflammatory status through Rho/NF-κB pathway. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Mechanical stimulation of cyclic tensile strain induces reduction of pluripotent related gene expressions via activation of Rho/ROCK and subsequent decreasing of AKT phosphorylation in human induced pluripotent stem cells

    International Nuclear Information System (INIS)

    Teramura, Takeshi; Takehara, Toshiyuki; Onodera, Yuta; Nakagawa, Koichi; Hamanishi, Chiaki; Fukuda, Kanji

    2012-01-01

    Highlights: ► Mechanical stimulation is an important factor for regulation of stem cell fate. ► Cyclic stretch to human induced pluripotent stem cells activated small GTPase Rho. ► Rho-kinase activation attenuated pluripotency via inhibition of AKT activation. ► This reaction could be reproduced only by transfection of dominant active Rho. ► Rho/ROCK are important molecules in mechanotransduction and control of stemness. -- Abstract: Mechanical stimulation has been shown to regulate the proliferation and differentiation of stem cells. However, the effects of the mechanical stress on the stemness or related molecular mechanisms have not been well determined. Pluripotent stem cells such as embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are used as good materials for cell transplantation therapy and research of mammalian development, since they can self-renew infinitely and differentiate into various cell lineages. Here we demonstrated that the mechanical stimulation to human iPS cells altered alignment of actin fibers and expressions of the pluripotent related genes Nanog, POU5f1 and Sox2. In the mechanically stimulated iPS cells, small GTPase Rho was activated and interestingly, AKT phosphorylation was decreased. Inhibition of Rho-associated kinase ROCK recovered the AKT phosphorylation and the gene expressions. These results clearly suggested that the Rho/ROCK is a potent primary effector of mechanical stress in the pluripotent stem cells and it participates to pluripotency-related signaling cascades as an upper stream regulator.

  5. Rho GTPase expression in human myeloid cells.

    Directory of Open Access Journals (Sweden)

    Suzanne F G van Helden

    Full Text Available Myeloid cells are critical for innate immunity and the initiation of adaptive immunity. Strict regulation of the adhesive and migratory behavior is essential for proper functioning of these cells. Rho GTPases are important regulators of adhesion and migration; however, it is unknown which Rho GTPases are expressed in different myeloid cells. Here, we use a qPCR-based approach to investigate Rho GTPase expression in myeloid cells.We found that the mRNAs encoding Cdc42, RhoQ, Rac1, Rac2, RhoA and RhoC are the most abundant. In addition, RhoG, RhoB, RhoF and RhoV are expressed at low levels or only in specific cell types. More differentiated cells along the monocyte-lineage display lower levels of Cdc42 and RhoV, while RhoC mRNA is more abundant. In addition, the Rho GTPase expression profile changes during dendritic cell maturation with Rac1 being upregulated and Rac2 downregulated. Finally, GM-CSF stimulation, during macrophage and osteoclast differentiation, leads to high expression of Rac2, while M-CSF induces high levels of RhoA, showing that these cytokines induce a distinct pattern. Our data uncover cell type specific modulation of the Rho GTPase expression profile in hematopoietic stem cells and in more differentiated cells of the myeloid lineage.

  6. Repigmentation in vitiligo using the Janus kinase inhibitor tofacitinib may require concomitant light exposure.

    Science.gov (United States)

    Liu, Lucy Y; Strassner, James P; Refat, Maggi A; Harris, John E; King, Brett A

    2017-10-01

    Vitiligo is an autoimmune disease in which cutaneous depigmentation occurs. Existing therapies are often inadequate. Prior reports have shown benefit of the Janus kinase (JAK) inhibitors. To evaluate the efficacy of the JAK 1/3 inhibitor tofacitinib in the treatment of vitiligo. This is a retrospective case series of 10 consecutive patients with vitiligo treated with tofacitinib. Severity of disease was assessed by body surface area of depigmentation. Ten consecutive patients were treated with tofacitinib. Five patients achieved some repigmentation at sites of either sunlight exposure or low-dose narrowband ultraviolet B phototherapy. Suction blister sampling revealed that the autoimmune response was inhibited during treatment in both responding and nonresponding lesions, suggesting that light rather than immunosuppression was primarily required for melanocyte regeneration. Limitations include the small size of the study population, retrospective nature of the study, and lack of a control group. Treatment of vitiligo with JAK inhibitors appears to require light exposure. In contrast to treatment with phototherapy alone, repigmentation during treatment with JAK inhibitors may require only low-level light. Maintenance of repigmentation may be achieved with JAK inhibitor monotherapy. These results support a model wherein JAK inhibitors suppress T cell mediators of vitiligo and light exposure is necessary for stimulation of melanocyte regeneration. Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  7. Systematic Kinase Inhibitor Profiling Identifies CDK9 as a Synthetic Lethal Target in NUT Midline Carcinoma

    Directory of Open Access Journals (Sweden)

    Johannes Brägelmann

    2017-09-01

    Full Text Available Kinase inhibitors represent the backbone of targeted cancer therapy, yet only a limited number of oncogenic drivers are directly druggable. By interrogating the activity of 1,505 kinase inhibitors, we found that BRD4-NUT-rearranged NUT midline carcinoma (NMC cells are specifically killed by CDK9 inhibition (CDK9i and depend on CDK9 and Cyclin-T1 expression. We show that CDK9i leads to robust induction of apoptosis and of markers of DNA damage response in NMC cells. While both CDK9i and bromodomain inhibition over time result in reduced Myc protein expression, only bromodomain inhibition induces cell differentiation and a p21-induced cell-cycle arrest in these cells. Finally, RNA-seq and ChIP-based analyses reveal a BRD4-NUT-specific CDK9i-induced perturbation of transcriptional elongation. Thus, our data provide a mechanistic basis for the genotype-dependent vulnerability of NMC cells to CDK9i that may be of relevance for the development of targeted therapies for NMC patients.

  8. Serum concentrations of nitrite and malondialdehyde as markers of oxidative stress in chronic myeloid leukemia patients treated with tyrosine kinase inhibitors

    Directory of Open Access Journals (Sweden)

    Maria Juracy Petrola

    2012-01-01

    Full Text Available BACKGROUND: Chronic myeloid leukemia is a neoplasm characterized by clonal expansion of hematopoietic progenitor cells resulting from the (9:22(q34,11 translocation. The tyrosine kinase abl fusion protein,the initial leukemogenic event in chronic myeloid leukemia, is constitutively activated thus inducing the production of reactive oxygen species. Of particular relevance is the fact that an increase in reactive oxygen species can facilitate genomic instability and may contribute to disease progression. OBJETIVE: To evaluate oxidative stress by determining the levels of malondialdehyde and nitrite in chronic myeloid leukemia patients under treatment with 1st and 2nd generation tyrosine kinase inhibitors monitored at a referral hospital in Fortaleza, Ceará. METHODS: A cross-sectional study was performed of 64 male and female adults. Patients were stratified according to treatment. The levels of malondialdehyde and nitrite were determined by spectrophotometry. Statistical differences between groups were observed using the Student t-test and Fisher's exact test. The results are expressed as mean ± standard error of mean. The significance level was set for a p-value < 0.05 in all analyses. RESULTS: The results show significantly higher mean concentrations of nitrite and malondialdehyde in chronic myeloid leukemia patients using second-generation tyrosine kinase inhibitors compared to patients on imatinib. Conclusion: It follows that chronic myeloid leukemia patients present higher oxidative activity and that the increases in oxidative damage markers can indicate resistance to 1st generation tyrosine kinase inhibitors.

  9. Applying ligands profiling using multiple extended electron distribution based field templates and feature trees similarity searching in the discovery of new generation of urea-based antineoplastic kinase inhibitors.

    Directory of Open Access Journals (Sweden)

    Eman M Dokla

    Full Text Available This study provides a comprehensive computational procedure for the discovery of novel urea-based antineoplastic kinase inhibitors while focusing on diversification of both chemotype and selectivity pattern. It presents a systematic structural analysis of the different binding motifs of urea-based kinase inhibitors and the corresponding configurations of the kinase enzymes. The computational model depends on simultaneous application of two protocols. The first protocol applies multiple consecutive validated virtual screening filters including SMARTS, support vector-machine model (ROC = 0.98, Bayesian model (ROC = 0.86 and structure-based pharmacophore filters based on urea-based kinase inhibitors complexes retrieved from literature. This is followed by hits profiling against different extended electron distribution (XED based field templates representing different kinase targets. The second protocol enables cancericidal activity verification by using the algorithm of feature trees (Ftrees similarity searching against NCI database. Being a proof-of-concept study, this combined procedure was experimentally validated by its utilization in developing a novel series of urea-based derivatives of strong anticancer activity. This new series is based on 3-benzylbenzo[d]thiazol-2(3H-one scaffold which has interesting chemical feasibility and wide diversification capability. Antineoplastic activity of this series was assayed in vitro against NCI 60 tumor-cell lines showing very strong inhibition of GI(50 as low as 0.9 uM. Additionally, its mechanism was unleashed using KINEX™ protein kinase microarray-based small molecule inhibitor profiling platform and cell cycle analysis showing a peculiar selectivity pattern against Zap70, c-src, Mink1, csk and MeKK2 kinases. Interestingly, it showed activity on syk kinase confirming the recent studies finding of the high activity of diphenyl urea containing compounds against this kinase. Allover, the new series

  10. Inhibition of large conductance calcium-dependent potassium ...

    African Journals Online (AJOL)

    conductance, calcium and voltage- dependent potassium (BKCa) channels thereby promoting vasoconstriction. Our results show that the Rho-kinase inhibitor, Y-27632, induced concentration-dependent relaxation in rat mesenteric artery.

  11. Comparative evaluation of bone marrow cells morpho-functional activity in chronic myeloid leukemia patients treated with tyrosine kinase inhibitors of the first and second generation

    Directory of Open Access Journals (Sweden)

    I. O. Zhaleyko

    2014-07-01

    Full Text Available The efficiency of using the culture techniques of research for monitoring the patient’s response to the treatment by tyrosine kinase inhibitors of the first and second generation is shown. Thus, the functional activity of bone marrow cells in patients having the optimal treatment response to inhibitors of tyrosine kinases was significantly lower compared with patients with the acquired resistance to the drug, and patients who had CML diagnosed for first time. Furthermore, for patients with the optimal response to the nilotinib therapy, numbers of colonies in semi-solid agar in vitro was lower, than in patients with the optimal response to imatinib. When the leukaemic cell clone becomes resistant to tyrosine kinase inhibitors, the prevalence of early cells of granulocyte-macrophage hematopoietic stem cells is observed in CFU culture which can be an important prognostic factor for choosing the appropriate treatment strategy.

  12. Lack of Prenylated Proteins, Autophagy Impairment and Apoptosis in SH-SY5Y Neuronal Cell Model of Mevalonate Kinase Deficiency

    Directory of Open Access Journals (Sweden)

    Paola Maura Tricarico

    2017-03-01

    Full Text Available Background/Aims: Mevalonate Kinase Deficiency (MKD, is a hereditary disease due to mutations in mevalonate kinase gene (MVK. MKD has heterogeneous clinical phenotypes: the correlation between MVK mutations and MKD clinical phenotype is still to be fully elucidated. Deficiency of prenylated proteins has been hypothesized as possible MKD pathogenic mechanism. Based on this hypothesis and considering that neurologic impairment characterizes Mevalonic Aciduria (MA, the most severe form of MKD, we studied the effects of I268T and N301T MVK mutations on protein prenylation, autophagy and programmed cell death in SH-SY5Y neuroblastoma cell lines. Methods: SH-SY5Y cells were transiently transfected, with the pCMV-6 plasmid containing MVK wild type and the two mutated sequences. Protein prenylation levels were evaluated using GFP-RhoA-F to assess farnesylation, and GFP-RhoA to evaluate geranylgeranylation; autophagy was measured by evaluating LC3 and p62 protein levels, while Annexin V-FITC and Propidium Iodide staining allowed apoptosis detection. Results: MVK mutants’ over-expression causes decreased levels of farnesylation and geranylgeranylation, and also increased LC3 lipidation in SH-SY5Y, with concomitant p62 accumulation. Treatment with bafilomycin A1 (an inhibitor of vacuolar H+-ATPase, a late autophagy inhibitor further increase LC3-II and p62 levels, suggesting that degradation of autophagolysosome could be impaired. SH-SY5Y, with both MVK mutants, showed apoptosis increase; the presence of N301T associated with augmented cell death. Conclusions: We hypothesize that mevalonate pathway impairment causes alteration of farnesylation and geranylgeranylation proteins and alteration of the autophagic flux; these changes can induce apoptosis, possibly more relevant in the presence of N301T mutation.

  13. Lack of Prenylated Proteins, Autophagy Impairment and Apoptosis in SH-SY5Y Neuronal Cell Model of Mevalonate Kinase Deficiency.

    Science.gov (United States)

    Tricarico, Paola Maura; Romeo, Alessandra; Gratton, Rossella; Crovella, Sergio; Celsi, Fulvio

    2017-01-01

    Mevalonate Kinase Deficiency (MKD), is a hereditary disease due to mutations in mevalonate kinase gene (MVK). MKD has heterogeneous clinical phenotypes: the correlation between MVK mutations and MKD clinical phenotype is still to be fully elucidated. Deficiency of prenylated proteins has been hypothesized as possible MKD pathogenic mechanism. Based on this hypothesis and considering that neurologic impairment characterizes Mevalonic Aciduria (MA), the most severe form of MKD, we studied the effects of I268T and N301T MVK mutations on protein prenylation, autophagy and programmed cell death in SH-SY5Y neuroblastoma cell lines. SH-SY5Y cells were transiently transfected, with the pCMV-6 plasmid containing MVK wild type and the two mutated sequences. Protein prenylation levels were evaluated using GFP-RhoA-F to assess farnesylation, and GFP-RhoA to evaluate geranylgeranylation; autophagy was measured by evaluating LC3 and p62 protein levels, while Annexin V-FITC and Propidium Iodide staining allowed apoptosis detection. MVK mutants' over-expression causes decreased levels of farnesylation and geranylgeranylation, and also increased LC3 lipidation in SH-SY5Y, with concomitant p62 accumulation. Treatment with bafilomycin A1 (an inhibitor of vacuolar H+-ATPase, a late autophagy inhibitor) further increase LC3-II and p62 levels, suggesting that degradation of autophagolysosome could be impaired. SH-SY5Y, with both MVK mutants, showed apoptosis increase; the presence of N301T associated with augmented cell death. We hypothesize that mevalonate pathway impairment causes alteration of farnesylation and geranylgeranylation proteins and alteration of the autophagic flux; these changes can induce apoptosis, possibly more relevant in the presence of N301T mutation. © 2017 The Author(s)Published by S. Karger AG, Basel.

  14. The invisible hand: regulation of RHO GTPases by RHOGDIs

    OpenAIRE

    Garcia-Mata, Rafael; Boulter, Etienne; Burridge, Keith

    2011-01-01

    The 'invisible hand' is a term originally coined by Adam Smith in the Theory of Moral Sentiments to describe the forces of self-interest, competition, and supply and demand that regulate the resources in society. This metaphor continues to be used by economists to describe the self-regulating nature of a market economy. The same metaphor can be used to describe the RHO-specific guanine nucleotide dissociation inhibitor (RHOGDI) family, which operates in the background, as an invisible hand, u...

  15. Tyrosine kinase inhibitor BIBF1120 ameliorates inflammation, angiogenesis and fibrosis in CCl4-induced liver fibrogenesis mouse model

    NARCIS (Netherlands)

    Öztürk Akcora, Büsra; Storm, Gerrit; Prakash, Jai; Bansal, Ruchi

    2017-01-01

    Hepatic fibrosis, a progressive chronic disease mainly caused by hepatitis viral infections, alcohol abuse or metabolic syndrome leading to liver dysfunction and is the growing cause of mortality worldwide. Tyrosine kinase inhibitor BIBF1120 (Nintedanib) has been evaluated in clinical trials for

  16. Tyrosine kinase inhibitor SU6668 represses chondrosarcoma growth via antiangiogenesis in vivo

    International Nuclear Information System (INIS)

    Klenke, Frank M; Abdollahi, Amir; Bertl, Elisabeth; Gebhard, Martha-Maria; Ewerbeck, Volker; Huber, Peter E; Sckell, Axel

    2007-01-01

    As chondrosarcomas are resistant to chemotherapy and ionizing radiation, therapeutic options are limited. Radical surgery often cannot be performed. Therefore, additional therapies such as antiangiogenesis represent a promising strategy for overcoming limitations in chondrosarcoma therapy. There is strong experimental evidence that SU6668, an inhibitor of the angiogenic tyrosine kinases Flk-1/KDR, PDGFRbeta and FGFR1 can induce growth inhibition of various primary tumors. However, the effectiveness of SU6668 on malignant primary bone tumors such as chondrosarcomas has been rarely investigated. Therefore, the aim of this study was to investigate the effects of SU6668 on chondrosarcoma growth, angiogenesis and microcirculation in vivo. In 10 male severe combined immunodeficient (SCID) mice, pieces of SW1353 chondrosarcomas were implanted into a cranial window preparation where the calvaria serves as the site for the orthotopic implantation of bone tumors. From day 7 after tumor implantation, five animals were treated with SU6668 (250 mg/kg body weight, s.c.) at intervals of 48 hours (SU6668), and five animals with the equivalent amount of the CMC-based vehicle (Control). Angiogenesis, microcirculation, and growth of SW 1353 tumors were analyzed by means of intravital microscopy. SU6668 induced a growth arrest of chondrosarcomas within 7 days after the initiation of the treatment. Compared to Controls, SU6668 decreased functional vessel density and tumor size, respectively, by 37% and 53% on day 28 after tumor implantation. The time course of the experiments demonstrated that the impact on angiogenesis preceded the anti-tumor effect. Histological and immunohistochemical results confirmed the intravital microscopy findings. SU6668 is a potent inhibitor of chondrosarcoma tumor growth in vivo. This effect appears to be induced by the antiangiogenic effects of SU6668, which are mediated by the inhibition of the key angiogenic receptor tyrosine kinases Flk-1/KDR, PDGFRbeta

  17. A Novel, Broad-Spectrum Inhibitor of Enterovirus Replication That Targets Host Cell Factor Phosphatidylinositol 4-Kinase IIIβ

    Science.gov (United States)

    van der Schaar, Hilde M.; Leyssen, Pieter; Thibaut, Hendrik J.; de Palma, Armando; van der Linden, Lonneke; Lanke, Kjerstin H. W.; Lacroix, Céline; Verbeken, Erik; Conrath, Katja; MacLeod, Angus M.; Mitchell, Dale R.; Palmer, Nicholas J.; van de Poël, Hervé; Andrews, Martin

    2013-01-01

    Despite their high clinical and socioeconomic impacts, there is currently no approved antiviral therapy for the prophylaxis or treatment of enterovirus infections. Here we report on a novel inhibitor of enterovirus replication, compound 1, 2-fluoro-4-(2-methyl-8-(3-(methylsulfonyl)benzylamino)imidazo[1,2-a]pyrazin-3-yl)phenol. This compound exhibited a broad spectrum of antiviral activity, as it inhibited all tested species of enteroviruses and rhinoviruses, with 50% effective concentrations ranging between 4 and 71 nM. After a lengthy resistance selection process, coxsackievirus mutants resistant to compound 1 were isolated that carried substitutions in their 3A protein. Remarkably, the same substitutions were recently shown to provide resistance to inhibitors of phosphatidylinositol 4-kinase IIIβ (PI4KIIIβ), a lipid kinase that is essential for enterovirus replication, suggesting that compound 1 may also target this host factor. Accordingly, compound 1 directly inhibited PI4KIIIβ in an in vitro kinase activity assay. Furthermore, the compound strongly reduced the PI 4-phosphate levels of the Golgi complex in cells. Rescue of coxsackievirus replication in the presence of compound 1 by a mutant PI4KIIIβ carrying a substitution in its ATP-binding pocket revealed that the compound directly binds the kinase at this site. Finally, we determined that an analogue of compound 1, 3-(3-fluoro-4-methoxyphenyl)-2-methyl-N-(pyridin-4-ylmethyl)imidazo[1,2-a]pyrazin-8-amine, is well tolerated in mice and has a dose-dependent protective activity in a coxsackievirus serotype B4-induced pancreatitis model. PMID:23896472

  18. Anti-adipogenic effects of KD025 (SLx-2119), a ROCK2-specific inhibitor, in 3T3-L1 cells.

    Science.gov (United States)

    Diep, Duy Trong Vien; Hong, Kyungki; Khun, Triyeng; Zheng, Mei; Ul-Haq, Asad; Jun, Hee-Sook; Kim, Young-Bum; Chun, Kwang-Hoon

    2018-02-06

    Adipose tissue is a specialized organ that synthesizes and stores fat. During adipogenesis, Rho and Rho-associated kinase (ROCK) 2 are inactivated, which enhances the expression of pro-adipogenic genes and induces the loss of actin stress fibers. Furthermore, pan ROCK inhibitors enhance adipogenesis in 3T3-L1 cells. Here, we show that KD025 (formerly known as SLx-2119), a ROCK2-specific inhibitor, suppresses adipogenesis in 3T3-L1 cells partially through a ROCK2-independent mechanism. KD025 downregulated the expression of key adipogenic transcription factors PPARγ and C/EBPα during adipogenesis in addition to lipogenic factors FABP4 and Glut4. Interestingly, adipogenesis was blocked by KD025 during days 1~3 of differentiation; after differentiation terminated, lipid accumulation was unaffected. Clonal expansion occurred normally in KD025-treated cells. These results suggest that KD025 could function during the intermediate stage after clonal expansion. Data from depletion of ROCKs showed that KD025 suppressed cell differentiation partially independent of ROCK's activity. Furthermore, no further loss of actin stress fibers emerged in KD025-treated cells during and after differentiation compared to control cells. These results indicate that in contrast to the pro-adipogenic effect of pan-inhibitors, KD025 suppresses adipogenesis in 3T3-L1 cells by regulating key pro-adipogenic factors. This outcome further implies that KD025 could be a potential anti-adipogenic/obesity agent.

  19. Prevention of pulmonary vascular and myocardial remodeling by the combined tyrosine and serine-/threonine kinase inhibitor, sorafenib, in pulmonary hypertension and right heart failure

    Directory of Open Access Journals (Sweden)

    M. Klein

    2008-06-01

    Full Text Available Inhibition of tyrosine kinases can reverse pulmonary hypertension but little is known about the role of serine-/threonine kinases in vascular and myocardial remodeling. We investigated the effects of sorafenib, an inhibitor of the tyrosine kinases VEGFR, PDGFR and c-kit as well as the serine-/threonine kinase Raf-1, in pulmonary hypertension and right ventricular (RV pressure overload. In monocrotaline treated rats, sorafenib (10 mg·kg–1·d–1 p.o. reduced pulmonary arterial pressure, pulmonary artery muscularization and RV hypertrophy, and improved systemic hemodynamics (table 1. Sorafenib prevented phosphorylation of Raf-1 and suppressed activation of downstream signaling pathways (Erk 1/2. After pulmonary banding, sorafenib, but not the PDGFR/c-KIT/ABL-inhibitor imatinib reduced RV mass and RV filling pressure significantly. Congruent with these results, sorafenib only prevented ERK phosphorylation and vasopressin induced hypertrophy of the cardiomyocyte cell line H9c2 dose dependently (IC50 = 300 nM. Combined inhibition of tyrosine and serine-/threonine kinases by sorafenib prevents vascular and cardiac remodeling in pulmonary hypertension, which is partly mediated via inhibition of the Raf kinase pathway.

  20. Proteínas quinases: características estruturais e inibidores químicos Kinase protein: structural features and chemical inhibitors

    Directory of Open Access Journals (Sweden)

    Bárbara V. Silva

    2009-01-01

    Full Text Available Protein kinases are one of the largest protein families and they are responsible for regulation of a great number of signal transduction pathways in cells, through the phosphorylation of serine, threonine, or tyrosine residues. Deregulation of these enzymes is associated with several diseases including cancer, diabetes and inflammation. For this reason, specific inhibition of tyrosine or serine/threonine kinases may represent an interesting therapeutic approach. The most important types of protein kinases, their structural features and chemical inhibitors are discussed in this paper. Emphasis is given to the small-molecule drugs that target the ATP-binding sites of these enzymes.

  1. Effects of inhibitors of protein kinase C and NO-synthase on the radiation-induced cytogenetic adaptive response in Chinese hamster cells in culture

    International Nuclear Information System (INIS)

    Gil'yano, N.Ya.; Bondarev, G.N.; Bikineeva, E.G.; Krasotskaya, G.I.; Noskin, L.A.

    2001-01-01

    The effect of the serine-threonin kinase inhibitor - staurosporine and inhibitor of NO-synthase - L-NAME on the radiation-induced adaptive response were studied in fibroblasts of Chinese hamster in culture. It is shown that staurosporine and L-NAME inhibit cytogenetic adaptive response induced by β-particles in low doses. Inhibition is not connected with radiosensitizing effect of these agents. L-NAME decreases significantly the γ-rays-induced chromosome aberration yield also. Study confirms the role of protein kinase C in induction of the adaptive response and participation of NO-synthase in this process is noticed for the first time [ru

  2. RCP-driven α5β1 recycling suppresses Rac and promotes RhoA activity via the RacGAP1-IQGAP1 complex.

    Science.gov (United States)

    Jacquemet, Guillaume; Green, David M; Bridgewater, Rebecca E; von Kriegsheim, Alexander; Humphries, Martin J; Norman, Jim C; Caswell, Patrick T

    2013-09-16

    Inhibition of αvβ3 or expression of mutant p53 promotes invasion into fibronectin (FN)-containing extracellular matrix (ECM) by enhancing Rab-coupling protein (RCP)-dependent recycling of α5β1 integrin. RCP and α5β1 cooperatively recruit receptor tyrosine kinases, including EGFR1, to regulate their trafficking and downstream signaling via protein kinase B (PKB)/Akt, which, in turn, promotes invasive migration. In this paper, we identify a novel PKB/Akt substrate, RacGAP1, which is phosphorylated as a consequence of RCP-dependent α5β1 trafficking. Phosphorylation of RacGAP1 promotes its recruitment to IQGAP1 at the tips of invasive pseudopods, and RacGAP1 then locally suppresses the activity of the cytoskeletal regulator Rac and promotes the activity of RhoA in this subcellular region. This Rac to RhoA switch promotes the extension of pseudopodial processes and invasive migration into FN-containing matrices, in a RhoA-dependent manner. Thus, the localized endocytic trafficking of α5β1 within the tips of invasive pseudopods elicits signals that promote the reorganization of the actin cytoskeleton, protrusion, and invasion into FN-rich ECM.

  3. Roles of Apicomplexan protein kinases at each life cycle stage.

    Science.gov (United States)

    Kato, Kentaro; Sugi, Tatsuki; Iwanaga, Tatsuya

    2012-06-01

    Inhibitors of cellular protein kinases have been reported to inhibit the development of Apicomplexan parasites, suggesting that the functions of protozoan protein kinases are critical for their life cycle. However, the specific roles of these protein kinases cannot be determined using only these inhibitors without molecular analysis, including gene disruption. In this report, we describe the functions of Apicomplexan protein kinases in each parasite life stage and the potential of pre-existing protein kinase inhibitors as Apicomplexan drugs against, mainly, Plasmodium and Toxoplasma. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Activity of EGFR-tyrosine kinase and ALK inhibitors for EML4–ALK-rearranged non–small–cell lung cancer harbored coexisting EGFR mutation

    International Nuclear Information System (INIS)

    Miyanaga, Akihiko; Kawamoto, Masashi; Tsuchiya, Shinichi; Hagiwara, Koichi; Soda, Manabu; Takeuchi, Kengo; Yamamoto, Nobuyuki; Mano, Hiroyuki; Ishikawa, Yuichi; Gemma, Akihiko; Shimizu, Kumi; Noro, Rintaro; Seike, Masahiro; Kitamura, Kazuhiro; Kosaihira, Seiji; Minegishi, Yuji; Shukuya, Takehito; Yoshimura, Akinobu

    2013-01-01

    The EML4–ALK (echinoderm microtubule-associated protein-like 4 gene and the anaplastic lymphoma kinase gene) fusion oncogene represents a novel molecular target in a small subset of non–small–cell lung cancers (NSCLCs). The EML4–ALK fusion gene occurs generally in NSCLC without mutations in epidermal growth factor receptor (EGFR) and KRAS. We report that a case of EML4–ALK-positive NSCLC with EGFR mutation had a response of stable disease to both an EGFR tyrosine kinase inhibitor (EGFR-TKI) and ALK inhibitor. We described the first clinical report of a patient with EML4–ALK-positive NSCLC with EGFR mutation that had a response of stable disease to both single-agent EGFR-TKI and ALK inhibitor. EML4–ALK translocation may be associated with resistance to EGFR-TKI, and EGFR signaling may contribute to resistance to ALK inhibitor in EML4–ALK-positive NSCLC

  5. Tyrosine kinase inhibitors induced immune thrombocytopenia in chronic myeloid leukemia?

    Directory of Open Access Journals (Sweden)

    Avital F. Barak

    2011-12-01

    Full Text Available The outcome and quality of life of chronic myeloid leukemia (CML patients has remarkably changed with the treatment of tyrosine kinase inhibitors (TKIs. Currently, hematopoietic stem cell transplantation (HSCT is considered mainly as a third line salvage therapy in cases of TKIs resistance or intolerance. Here we describe a patient with chronic phase CML who developed both resistance and late occurrence of s severe thrombocytopenia on first and second generation TKIs and eventually underwent HSCT. Although the mechanism of the myelosuppression is not fully understood, we showed for the first time the development of dose dependent platelet antibodies in the presence of TKIs, suggesting the possibility of TKIs induced thrombocytopenia. Our case emphasizes that late development of severe myelosuppression during imatinib treatment is probably an important indication for consideration of early HSCT.

  6. Investigating the role of c-Jun N-terminal kinases in the proliferation of Werner syndrome fibroblasts using diaminopyridine inhibitors

    Directory of Open Access Journals (Sweden)

    Davis Terence

    2011-12-01

    Full Text Available Abstract Fibroblasts derived from the progeroid Werner syndrome show reduced replicative lifespan and a "stressed" morphology, both alleviated using the MAP kinase inhibitor SB203580. However, interpretation of these data is problematical because although SB203580 has the stress-activated kinases p38 and JNK1/2 as its preferred targets, it does show relatively low overall kinase selectivity. Several lines of data support a role for both p38 and JNK1/2 activation in the control of cellular proliferation and also the pathology of diseases of ageing, including type II diabetes, diseases to which Werner Syndrome individuals are prone, thus making the use of JNK inhibitors attractive as possible therapeutics. We have thus tested the effects of the widely used JNK inhibitor SP600125 on the proliferation and morphology of WS cells. In addition we synthesised and tested two recently described aminopyridine based inhibitors. SP600125 treatment resulted in the cessation of proliferation of WS cells and resulted in a senescent-like cellular phenotype that does not appear to be related to the inhibition of JNK1/2. In contrast, use of the more selective aminopyridine CMPD 6o at concentrations that fully inhibit JNK1/2 had a positive effect on cellular proliferation of immortalised WS cells, but no effect on the replicative lifespan of primary WS fibroblasts. In addition, CMPD 6o corrected the stressed WS cellular morphology. The aminopyridine CMPD 6r, however, had little effect on WS cells. CMDP 6o was also found to be a weak inhibitor of MK2, which may partially explain its effects on WS cells, since MK2 is known to be involved in regulating cellular morphology via HSP27 phosphorylation, and is thought to play a role in cell cycle arrest. These data suggest that total JNK1/2 activity does not play a substantial role in the proliferation control in WS cells.

  7. PTP1B inhibitor promotes endothelial cell motility by activating the DOCK180/Rac1 pathway.

    Science.gov (United States)

    Wang, Yuan; Yan, Feng; Ye, Qing; Wu, Xiao; Jiang, Fan

    2016-04-07

    Promoting endothelial cell (EC) migration is important not only for therapeutic angiogenesis, but also for accelerating re-endothelialization after vessel injury. Several recent studies have shown that inhibition of protein tyrosine phosphatase 1B (PTP1B) may promote EC migration and angiogenesis by enhancing the vascular endothelial growth factor receptor-2 (VEGFR2) signalling. In the present study, we demonstrated that PTP1B inhibitor could promote EC adhesion, spreading and migration, which were abolished by the inhibitor of Rac1 but not RhoA GTPase. PTP1B inhibitor significantly increased phosphorylation of p130Cas, and the interactions among p130Cas, Crk and DOCK180; whereas the phosphorylation levels of focal adhesion kinase, Src, paxillin, or Vav2 were unchanged. Gene silencing of DOCK180, but not Vav2, abrogated the effects of PTP1B inhibitor on EC motility. The effects of PTP1B inhibitor on EC motility and p130Cas/DOCK180 activation persisted in the presence of the VEGFR2 antagonist. In conclusion, we suggest that stimulation of the DOCK180 pathway represents an alternative mechanism of PTP1B inhibitor-stimulated EC motility, which does not require concomitant VEGFR2 activation as a prerequisite. Therefore, PTP1B inhibitor may be a useful therapeutic strategy for promoting EC migration in cardiovascular patients in which the VEGF/VEGFR functions are compromised.

  8. Rho GTPase function in tumorigenesis

    DEFF Research Database (Denmark)

    Karlsson, R; Pedersen, Esben Ditlev Kølle; Wang, Zhipeng

    2009-01-01

    , for that reason, Rho GTPases, their regulators, and their effectors have been suggested to control tumor formation and progression in humans. However, while the tumor-relevant functions of Rho GTPases are very well documented in vitro, we are only now beginning to assess their contribution to cancer in human...... patients and in animal models. This review will give a very brief overview of Rho GTPase function in general and then focus on in vivo evidence for a role of Rho GTPases in malignant tumors, both in human patients and in genetically modified mice....

  9. Increased RhoA prenylation in the loechrig (loe mutant leads to progressive neurodegeneration.

    Directory of Open Access Journals (Sweden)

    Mandy Cook

    Full Text Available The Drosophila mutant loechrig (loe shows age-dependent degeneration of the nervous system and is caused by the loss of a neuronal isoform of the AMP-activated protein kinase (AMPK γ-subunit (also known as SNF4Aγ. The trimeric AMPK complex is activated by low energy levels and metabolic insults and regulates multiple important signal pathways that control cell metabolism. A well-known downstream target of AMPK is hydroxyl-methylglutaryl-CoA reductase (HMGR, a key enzyme in isoprenoid synthesis, and we have previously shown that HMGR genetically interacts with loe and affects the severity of the degenerative phenotype. Prenylation of proteins like small G-proteins is an important posttranslational modification providing lipid moieties that allow the association of these proteins with membranes, thereby facilitating their subsequent activation. Rho proteins have been extensively studied in neuronal outgrowth, however, much less is known about their function in neuronal maintenance. Here we show that the loe mutation interferes with isoprenoid synthesis, leading to increased prenylation of the small GTPase Rho1, the fly orthologue of vertebrate RhoA. We also demonstrate that increased prenylation and Rho1 activity causes neurodegeneration and aggravates the behavioral and degenerative phenotypes of loe. Because we cannot detect defects in the development of the central nervous system in loe, this suggests that loe only interferes with the function of the RhoA pathway in maintaining neuronal integrity during adulthood. In addition, our results show that alterations in isoprenoids can result in progressive neurodegeneration, supporting findings in vertebrates that prenylation may play a role in neurodegenerative diseases like Alzheimer's Disease.

  10. Abnormal Activation of RhoA/ROCK-I Signaling in Junctional Zone Smooth Muscle Cells of Patients With Adenomyosis.

    Science.gov (United States)

    Wang, S; Duan, H; Zhang, Y; Sun, F Q

    2016-03-01

    Adenomyosis (ADS) is a common estrogen-dependent gynecological disease with unknown etiology. The RhoA/Rho-kinase (ROCK) signaling pathway is involved in various cellular functions, including migration, proliferation, and smooth muscle contraction. Here we examined the potential role of this pathway in junctional zone (JZ) contraction in women with and without ADS. We demonstrated that in the normal JZ, RhoA and ROCK-I messenger RNA (mRNA) and protein expression was significantly higher in the proliferative phase of the menstrual cycle than in the secretory phase. Expression of RhoA and ROCK-I in the JZ from women with ADS was significantly higher than in the control women and showed no significant differences across the menstrual cycle. Treatment of JZ smooth muscle cells (JZSMCs) with estrogen at 0, 1, 10, or 100 nmol/L for 24 hours resulted in increased expression of RhoA, ROCK-I, and myosin light-chain (MLC) phosphorylation (p-MLC) in a dose-dependent manner. In parallel to its effects on p-MLC, estrogen-mediated, dose-dependent contraction responses in JZSMCs. Estrogen-mediated contraction in the ADS group was significantly higher than in the controls and also showed no significant differences across the menstrual cycle. These effects were suppressed in the presence of ICI 182780 or Y27632, supporting an estrogen receptor-dependent and RhoA activation-dependent mechanism. Our results indicate that the level of RhoA and ROCK-I increases in patients with ADS and the cyclic change is lost. Estrogen may affect uterine JZ contraction of ADS by enhancing RhoA/ ROCK-I signaling. © The Author(s) 2015.

  11. A Discovery Strategy for Selective Inhibitors of c-Src in Complex with the Focal Adhesion Kinase SH3/SH2-binding Region.

    Science.gov (United States)

    Moroco, Jamie A; Baumgartner, Matthew P; Rust, Heather L; Choi, Hwan Geun; Hur, Wooyoung; Gray, Nathanael S; Camacho, Carlos J; Smithgall, Thomas E

    2015-08-01

    The c-Src tyrosine kinase co-operates with the focal adhesion kinase to regulate cell adhesion and motility. Focal adhesion kinase engages the regulatory SH3 and SH2 domains of c-Src, resulting in localized kinase activation that contributes to tumor cell metastasis. Using assay conditions where c-Src kinase activity required binding to a tyrosine phosphopeptide based on the focal adhesion kinase SH3-SH2 docking sequence, we screened a kinase-biased library for selective inhibitors of the Src/focal adhesion kinase peptide complex versus c-Src alone. This approach identified an aminopyrimidinyl carbamate compound, WH-4-124-2, with nanomolar inhibitory potency and fivefold selectivity for c-Src when bound to the phospho-focal adhesion kinase peptide. Molecular docking studies indicate that WH-4-124-2 may preferentially inhibit the 'DFG-out' conformation of the kinase active site. These findings suggest that interaction of c-Src with focal adhesion kinase induces a unique kinase domain conformation amenable to selective inhibition. © 2014 John Wiley & Sons A/S.

  12. Crystal structure of human cyclin-dependent kinase-2 complex with MK2 inhibitor TEI-I01800: insight into the selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Fujino, Aiko; Fukushima, Kei; Kubota, Takaharu; Kosugi, Tomomi; Takimoto-Kamimura, Midori, E-mail: m.kamimura@teijin.co.jp [Teijin Pharma Limited, 4-3-2 Asahigaoka, Hino-shi, Tokyo 191-8512 (Japan)

    2013-11-01

    The Gly-rich loop of cyclin-dependent kinase 2 (CDK2) bound to TEI-I01800 as an MK2 specific inhibitor forms a β-sheet which is a common structure in CDK2–ligand complexes. Here, the reason why TEI-I01800 does not become a strong inhibitor against CDK2 based on the conformation of TEI-I01800 is presented. Mitogen-activated protein kinase-activated protein kinase 2 (MK2 or MAPKAP-K2) is a Ser/Thr kinase from the p38 mitogen-activated protein kinase signalling pathway and plays an important role in inflammatory diseases. The crystal structure of the MK2–TEI-I01800 complex has been reported; its Gly-rich loop was found to form an α-helix, not a β-sheet as has been observed for other Ser/Thr kinases. TEI-I01800 is 177-fold selective against MK2 compared with CDK2; in order to understand the inhibitory mechanism of TEI-I01800, the cyclin-dependent kinase 2 (CDK2) complex structure with TEI-I01800 was determined at 2.0 Å resolution. Interestingly, the Gly-rich loop of CDK2 formed a β-sheet that was different from that of MK2. In MK2, TEI-I01800 changed the secondary structure of the Gly-rich loop from a β-sheet to an α-helix by collision between Leu70 and a p-ethoxyphenyl group at the 7-position and bound to MK2. However, for CDK2, TEI-I01800 bound to CDK2 without this structural change and lost the interaction with the substituent at the 7-position. In summary, the results of this study suggest that the reason for the selectivity of TEI-I01800 is the favourable conformation of TEI-I01800 itself, making it suitable for binding to the α-form MK2.

  13. The Phosphoinositide 3-Kinaseα Selective Inhibitor, BYL719, Enhances the Effect of the Protein Kinase C Inhibitor, AEB071, in GNAQ/GNA11 Mutant Uveal Melanoma Cells

    Science.gov (United States)

    Musi, Elgilda; Ambrosini, Grazia; de Stanchina, Elisa; Schwartz, Gary K.

    2014-01-01

    G-protein mutations are one of the most common mutations occurring in uveal melanoma activating the protein kinase C (PKC)/mitogen-activated protein kinase (MAPK) and phosphoinositide 3-Kinase (PI3K)/AKT pathways. In this study, we described the effect of dual pathway inhibition in uveal melanoma harboring GNAQ and GNA11 mutations via PKC inhibition with AEB071 (Sotrastaurin) and PI3k/AKT inhibition with BYL719, a selective PI3Kα inhibitor. Growth inhibition was observed in GNAQ/GNA11 mutant cells with AEB071 versus no activity in WT cells. In the GNAQ-mutant cells, AEB071 decreased phosphorylation of MARCKS, a substrate of PKC, along with ERK1/2 and ribosomal S6, but persistent AKT activation was present. BYL719 had minimal anti-proliferative activity in all uveal melanoma cell lines, and inhibited phosphorylation of AKT in most cell lines. In the GNA11 mutant cell line, similar effects were observed with ERK1/2 inhibition, mostly inhibited by BYL719. With the combination treatment, both GNAQ and GNA11 mutant cell lines showed synergistic inhibition of cell proliferation and apoptotic cell death. In vivo studies correlated with in vitro findings showing reduced xenograft tumor growth with the combination therapy in a GNAQ mutant model. These findings suggest a new therapy treatment option for G-protein mutant uveal melanoma with a focus on specific targeting of multiple downstream pathways as part of combination therapy. PMID:24563540

  14. Mechanical stimulation of cyclic tensile strain induces reduction of pluripotent related gene expressions via activation of Rho/ROCK and subsequent decreasing of AKT phosphorylation in human induced pluripotent stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Teramura, Takeshi, E-mail: teramura@med.kindai.ac.jp [Institute of Advanced Clinical Medicine, Kinki University, Faculty of Medicine, Osaka (Japan); Takehara, Toshiyuki; Onodera, Yuta [Institute of Advanced Clinical Medicine, Kinki University, Faculty of Medicine, Osaka (Japan); Nakagawa, Koichi; Hamanishi, Chiaki [Department of Orthopaedic Surgery, Kinki University, Faculty of Medicine, Osaka (Japan); Fukuda, Kanji [Institute of Advanced Clinical Medicine, Kinki University, Faculty of Medicine, Osaka (Japan); Department of Orthopaedic Surgery, Kinki University, Faculty of Medicine, Osaka (Japan)

    2012-01-13

    Highlights: Black-Right-Pointing-Pointer Mechanical stimulation is an important factor for regulation of stem cell fate. Black-Right-Pointing-Pointer Cyclic stretch to human induced pluripotent stem cells activated small GTPase Rho. Black-Right-Pointing-Pointer Rho-kinase activation attenuated pluripotency via inhibition of AKT activation. Black-Right-Pointing-Pointer This reaction could be reproduced only by transfection of dominant active Rho. Black-Right-Pointing-Pointer Rho/ROCK are important molecules in mechanotransduction and control of stemness. -- Abstract: Mechanical stimulation has been shown to regulate the proliferation and differentiation of stem cells. However, the effects of the mechanical stress on the stemness or related molecular mechanisms have not been well determined. Pluripotent stem cells such as embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are used as good materials for cell transplantation therapy and research of mammalian development, since they can self-renew infinitely and differentiate into various cell lineages. Here we demonstrated that the mechanical stimulation to human iPS cells altered alignment of actin fibers and expressions of the pluripotent related genes Nanog, POU5f1 and Sox2. In the mechanically stimulated iPS cells, small GTPase Rho was activated and interestingly, AKT phosphorylation was decreased. Inhibition of Rho-associated kinase ROCK recovered the AKT phosphorylation and the gene expressions. These results clearly suggested that the Rho/ROCK is a potent primary effector of mechanical stress in the pluripotent stem cells and it participates to pluripotency-related signaling cascades as an upper stream regulator.

  15. Regulation of Thrombin-Induced Lung Endothelial Cell Barrier Disruption by Protein Kinase C Delta.

    Directory of Open Access Journals (Sweden)

    Lishi Xie

    Full Text Available Protein Kinase C (PKC plays a significant role in thrombin-induced loss of endothelial cell (EC barrier integrity; however, the existence of more than 10 isozymes of PKC and tissue-specific isoform expression has limited our understanding of this important second messenger in vascular homeostasis. In this study, we show that PKCδ isoform promotes thrombin-induced loss of human pulmonary artery EC barrier integrity, findings substantiated by PKCδ inhibitory studies (rottlerin, dominant negative PKCδ construct and PKCδ silencing (siRNA. In addition, we identified PKCδ as a signaling mediator upstream of both thrombin-induced MLC phosphorylation and Rho GTPase activation affecting stress fiber formation, cell contraction and loss of EC barrier integrity. Our inhibitor-based studies indicate that thrombin-induced PKCδ activation exerts a positive feedback on Rho GTPase activation and contributes to Rac1 GTPase inhibition. Moreover, PKD (or PKCμ and CPI-17, two known PKCδ targets, were found to be activated by PKCδ in EC and served as modulators of cytoskeleton rearrangement. These studies clarify the role of PKCδ in EC cytoskeleton regulation, and highlight PKCδ as a therapeutic target in inflammatory lung disorders, characterized by the loss of barrier integrity, such as acute lung injury and sepsis.

  16. Discovery of Brigatinib (AP26113), a Phosphine Oxide-Containing, Potent, Orally Active Inhibitor of Anaplastic Lymphoma Kinase.

    Science.gov (United States)

    Huang, Wei-Sheng; Liu, Shuangying; Zou, Dong; Thomas, Mathew; Wang, Yihan; Zhou, Tianjun; Romero, Jan; Kohlmann, Anna; Li, Feng; Qi, Jiwei; Cai, Lisi; Dwight, Timothy A; Xu, Yongjin; Xu, Rongsong; Dodd, Rory; Toms, Angela; Parillon, Lois; Lu, Xiaohui; Anjum, Rana; Zhang, Sen; Wang, Frank; Keats, Jeffrey; Wardwell, Scott D; Ning, Yaoyu; Xu, Qihong; Moran, Lauren E; Mohemmad, Qurish K; Jang, Hyun Gyung; Clackson, Tim; Narasimhan, Narayana I; Rivera, Victor M; Zhu, Xiaotian; Dalgarno, David; Shakespeare, William C

    2016-05-26

    In the treatment of echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase positive (ALK+) non-small-cell lung cancer (NSCLC), secondary mutations within the ALK kinase domain have emerged as a major resistance mechanism to both first- and second-generation ALK inhibitors. This report describes the design and synthesis of a series of 2,4-diarylaminopyrimidine-based potent and selective ALK inhibitors culminating in identification of the investigational clinical candidate brigatinib. A unique structural feature of brigatinib is a phosphine oxide, an overlooked but novel hydrogen-bond acceptor that drives potency and selectivity in addition to favorable ADME properties. Brigatinib displayed low nanomolar IC50s against native ALK and all tested clinically relevant ALK mutants in both enzyme-based biochemical and cell-based viability assays and demonstrated efficacy in multiple ALK+ xenografts in mice, including Karpas-299 (anaplastic large-cell lymphomas [ALCL]) and H3122 (NSCLC). Brigatinib represents the most clinically advanced phosphine oxide-containing drug candidate to date and is currently being evaluated in a global phase 2 registration trial.

  17. Protein Kinase C Inhibitors as Modulators of Vascular Function and Their Application in Vascular Disease

    Directory of Open Access Journals (Sweden)

    Raouf A. Khalil

    2013-03-01

    Full Text Available Blood pressure (BP is regulated by multiple neuronal, hormonal, renal and vascular control mechanisms. Changes in signaling mechanisms in the endothelium, vascular smooth muscle (VSM and extracellular matrix cause alterations in vascular tone and blood vessel remodeling and may lead to persistent increases in vascular resistance and hypertension (HTN. In VSM, activation of surface receptors by vasoconstrictor stimuli causes an increase in intracellular free Ca2+ concentration ([Ca2+]i, which forms a complex with calmodulin, activates myosin light chain (MLC kinase and leads to MLC phosphorylation, actin-myosin interaction and VSM contraction. Vasoconstrictor agonists could also increase the production of diacylglycerol which activates protein kinase C (PKC. PKC is a family of Ca2+-dependent and Ca2+-independent isozymes that have different distributions in various blood vessels, and undergo translocation from the cytosol to the plasma membrane, cytoskeleton or the nucleus during cell activation. In VSM, PKC translocation to the cell surface may trigger a cascade of biochemical events leading to activation of mitogen-activated protein kinase (MAPK and MAPK kinase (MEK, a pathway that ultimately increases the myofilament force sensitivity to [Ca2+]i, and enhances actin-myosin interaction and VSM contraction. PKC translocation to the nucleus may induce transactivation of various genes and promote VSM growth and proliferation. PKC could also affect endothelium-derived relaxing and contracting factors as well as matrix metalloproteinases (MMPs in the extracellular matrix further affecting vascular reactivity and remodeling. In addition to vasoactive factors, reactive oxygen species, inflammatory cytokines and other metabolic factors could affect PKC activity. Increased PKC expression and activity have been observed in vascular disease and in certain forms of experimental and human HTN. Targeting of vascular PKC using PKC inhibitors may function in

  18. RCP-driven α5β1 recycling suppresses Rac and promotes RhoA activity via the RacGAP1–IQGAP1 complex

    Science.gov (United States)

    Jacquemet, Guillaume; Green, David M.; Bridgewater, Rebecca E.; von Kriegsheim, Alexander; Humphries, Martin J.; Norman, Jim C.

    2013-01-01

    Inhibition of αvβ3 or expression of mutant p53 promotes invasion into fibronectin (FN)-containing extracellular matrix (ECM) by enhancing Rab-coupling protein (RCP)–dependent recycling of α5β1 integrin. RCP and α5β1 cooperatively recruit receptor tyrosine kinases, including EGFR1, to regulate their trafficking and downstream signaling via protein kinase B (PKB)/Akt, which, in turn, promotes invasive migration. In this paper, we identify a novel PKB/Akt substrate, RacGAP1, which is phosphorylated as a consequence of RCP-dependent α5β1 trafficking. Phosphorylation of RacGAP1 promotes its recruitment to IQGAP1 at the tips of invasive pseudopods, and RacGAP1 then locally suppresses the activity of the cytoskeletal regulator Rac and promotes the activity of RhoA in this subcellular region. This Rac to RhoA switch promotes the extension of pseudopodial processes and invasive migration into FN-containing matrices, in a RhoA-dependent manner. Thus, the localized endocytic trafficking of α5β1 within the tips of invasive pseudopods elicits signals that promote the reorganization of the actin cytoskeleton, protrusion, and invasion into FN-rich ECM. PMID:24019536

  19. A targeted enzyme approach to sensitization of tyrosine kinase inhibitor-resistant breast cancer cells.

    Science.gov (United States)

    Giordano, Courtney R; Mueller, Kelly L; Terlecky, Laura J; Krentz, Kendra A; Bollig-Fischer, Aliccia; Terlecky, Stanley R; Boerner, Julie L

    2012-10-01

    Gefitinib is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) of potential use in patients with breast cancer. Unfortunately, in clinical studies, gefitinib is often ineffective indicating that resistance to EGFR inhibitors may be a common occurrence in cancer of the breast. EGFR has been shown to be overexpressed in breast cancer, and in particular remains hyperphosphorylated in cell lines such as MDA-MB-468 that are resistant to EGFR inhibitors. Here, we investigate the cause of this sustained phosphorylation and the molecular basis for the ineffectiveness of gefitinib. We show that reactive oxygen species (ROS), known to damage cellular macromolecules and to modulate signaling cascades in a variety of human diseases including cancers, appear to play a critical role in mediating EGFR TKI-resistance. Furthermore, elimination of these ROS through use of a cell-penetrating catalase derivative sensitizes the cells to gefitinib. These results suggest a new approach for the treatment of TKI-resistant breast cancer patients specifically, the targeting of ROS and attendant downstream oxidative stress and their effects on signaling cascades. Copyright © 2012. Published by Elsevier Inc.

  20. Adventures in Scaffold Morphing: Discovery of Fused Ring Heterocyclic Checkpoint Kinase 1 (CHK1) Inhibitors.

    Science.gov (United States)

    Yang, Bin; Vasbinder, Melissa M; Hird, Alexander W; Su, Qibin; Wang, Haixia; Yu, Yan; Toader, Dorin; Lyne, Paul D; Read, Jon A; Breed, Jason; Ioannidis, Stephanos; Deng, Chun; Grondine, Michael; DeGrace, Nancy; Whitston, David; Brassil, Patrick; Janetka, James W

    2018-02-08

    Checkpoint kinase 1 (CHK1) inhibitors are potential cancer therapeutics that can be utilized for enhancing the efficacy of DNA damaging agents. Multiple small molecule CHK1 inhibitors from different chemical scaffolds have been developed and evaluated in clinical trials in combination with chemotherapeutics and radiation treatment. Scaffold morphing of thiophene carboxamide ureas (TCUs), such as AZD7762 (1) and a related series of triazoloquinolines (TZQs), led to the identification of fused-ring bicyclic CHK1 inhibitors, 7-carboxamide thienopyridines (7-CTPs), and 7-carboxamide indoles. X-ray crystal structures reveal a key intramolecular noncovalent sulfur-oxygen interaction in aligning the hinge-binding carboxamide group to the thienopyridine core in a coplanar fashion. An intramolecular hydrogen bond to an indole NH was also effective in locking the carboxamide in the preferred bound conformation to CHK1. Optimization on the 7-CTP series resulted in the identification of lead compound 44, which displayed respectable drug-like properties and good in vitro and in vivo potency.

  1. The Pim kinases: new targets for drug development.

    Science.gov (United States)

    Swords, Ronan; Kelly, Kevin; Carew, Jennifer; Nawrocki, Stefan; Mahalingam, Devalingam; Sarantopoulos, John; Bearss, David; Giles, Francis

    2011-12-01

    The three Pim kinases are a small family of serine/threonine kinases regulating several signaling pathways that are fundamental to cancer development and progression. They were first recognized as pro-viral integration sites for the Moloney Murine Leukemia virus. Unlike other kinases, they possess a hinge region which creates a unique binding pocket for ATP. Absence of a regulatory domain means that these proteins are constitutively active once transcribed. Pim kinases are critical downstream effectors of the ABL (ableson), JAK2 (janus kinase 2), and Flt-3 (FMS related tyrosine kinase 1) oncogenes and are required by them to drive tumorigenesis. Recent investigations have established that the Pim kinases function as effective inhibitors of apoptosis and when overexpressed, produce resistance to the mTOR (mammalian target of rapamycin) inhibitor, rapamycin . Overexpression of the PIM kinases has been reported in several hematological and solid tumors (PIM 1), myeloma, lymphoma, leukemia (PIM 2) and adenocarcinomas (PIM 3). As such, the Pim kinases are a very attractive target for pharmacological inhibition in cancer therapy. Novel small molecule inhibitors of the human Pim kinases have been designed and are currently undergoing preclinical evaluation.

  2. Protein Tyrosine Phosphatase-PEST and β8 Integrin Regulate Spatiotemporal Patterns of RhoGDI1 Activation in Migrating Cells

    Science.gov (United States)

    Lee, Hye Shin; Cheerathodi, Mujeeburahiman; Chaki, Sankar P.; Reyes, Steve B.; Zheng, Yanhua; Lu, Zhimin; Paidassi, Helena; DerMardirossian, Celine; Lacy-Hulbert, Adam; Rivera, Gonzalo M.

    2015-01-01

    Directional cell motility is essential for normal development and physiology, although how motile cells spatiotemporally activate signaling events remains largely unknown. Here, we have characterized an adhesion and signaling unit comprised of protein tyrosine phosphatase (PTP)-PEST and the extracellular matrix (ECM) adhesion receptor β8 integrin that plays essential roles in directional cell motility. β8 integrin and PTP-PEST form protein complexes at the leading edge of migrating cells and balance patterns of Rac1 and Cdc42 signaling by controlling the subcellular localization and phosphorylation status of Rho GDP dissociation inhibitor 1 (RhoGDI1). Translocation of Src-phosphorylated RhoGDI1 to the cell's leading edge promotes local activation of Rac1 and Cdc42, whereas dephosphorylation of RhoGDI1 by integrin-bound PTP-PEST promotes RhoGDI1 release from the membrane and sequestration of inactive Rac1/Cdc42 in the cytoplasm. Collectively, these data reveal a finely tuned regulatory mechanism for controlling signaling events at the leading edge of directionally migrating cells. PMID:25666508

  3. Epigallocatechin gallate (EGCG), a major component of green tea, is a dual phosphoinositide-3-kinase/mTOR inhibitor

    International Nuclear Information System (INIS)

    Van Aller, Glenn S.; Carson, Jeff D.; Tang, Wei; Peng, Hao; Zhao, Lin; Copeland, Robert A.; Tummino, Peter J.; Luo, Lusong

    2011-01-01

    Research highlights: → Epigallocatechin-3-gallate (EGCG) is an ATP-competitive inhibitor of PI3K and mTOR with Ki values around 300 nM. → EGCG inhibits cell proliferation and AKT phosphorylation at Ser473 in MDA-MB-231and A549 cells. → Molecular docking studies show that EGCG binds well to the PI3K kinase domain active site. → These results suggest another important molecular mechanism for the anticancer activities of EGCG. -- Abstract: The PI3K signaling pathway is activated in a broad spectrum of human cancers, either directly by genetic mutation or indirectly via activation of receptor tyrosine kinases or inactivation of the PTEN tumor suppressor. The key nodes of this pathway have emerged as important therapeutic targets for the treatment of cancer. In this study, we show that (-)-epigallocatechin-3-gallate (EGCG), a major component of green tea, is an ATP-competitive inhibitor of both phosphoinositide-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) with K i values of 380 and 320 nM respectively. The potency of EGCG against PI3K and mTOR is within physiologically relevant concentrations. In addition, EGCG inhibits cell proliferation and AKT phosphorylation at Ser473 in MDA-MB-231 and A549 cells. Molecular docking studies show that EGCG binds well to the PI3K kinase domain active site, agreeing with the finding that EGCG competes for ATP binding. Our results suggest another important molecular mechanism for the anticancer activities of EGCG.

  4. An extracellular-matrix-specific GEF-GAP interaction regulates Rho GTPase crosstalk for 3D collagen migration.

    Science.gov (United States)

    Kutys, Matthew L; Yamada, Kenneth M

    2014-09-01

    Rho-family GTPases govern distinct types of cell migration on different extracellular matrix proteins in tissue culture or three-dimensional (3D) matrices. We searched for mechanisms selectively regulating 3D cell migration in different matrix environments and discovered a form of Cdc42-RhoA crosstalk governing cell migration through a specific pair of GTPase activator and inhibitor molecules. We first identified βPix, a guanine nucleotide exchange factor (GEF), as a specific regulator of migration in 3D collagen using an affinity-precipitation-based GEF screen. Knockdown of βPix specifically blocks cell migration in fibrillar collagen microenvironments, leading to hyperactive cellular protrusion accompanied by increased collagen matrix contraction. Live FRET imaging and RNAi knockdown linked this βPix knockdown phenotype to loss of polarized Cdc42 but not Rac1 activity, accompanied by enhanced, de-localized RhoA activity. Mechanistically, collagen phospho-regulates βPix, leading to its association with srGAP1, a GTPase-activating protein (GAP), needed to suppress RhoA activity. Our results reveal a matrix-specific pathway controlling migration involving a GEF-GAP interaction of βPix with srGAP1 that is critical for maintaining suppressive crosstalk between Cdc42 and RhoA during 3D collagen migration.

  5. Amphetamine activates Rho GTPase signaling to mediate dopamine transporter internalization and acute behavioral effects of amphetamine

    Science.gov (United States)

    Wheeler, David S.; Underhill, Suzanne M.; Stolz, Donna B.; Murdoch, Geoffrey H.; Thiels, Edda; Romero, Guillermo; Amara, Susan G.

    2015-01-01

    Acute amphetamine (AMPH) exposure elevates extracellular dopamine through a variety of mechanisms that include inhibition of dopamine reuptake, depletion of vesicular stores, and facilitation of dopamine efflux across the plasma membrane. Recent work has shown that the DAT substrate AMPH, unlike cocaine and other nontransported blockers, can also stimulate endocytosis of the plasma membrane dopamine transporter (DAT). Here, we show that when AMPH enters the cytoplasm it rapidly stimulates DAT internalization through a dynamin-dependent, clathrin-independent process. This effect, which can be observed in transfected cells, cultured dopamine neurons, and midbrain slices, is mediated by activation of the small GTPase RhoA. Inhibition of RhoA activity with C3 exotoxin or a dominant-negative RhoA blocks AMPH-induced DAT internalization. These actions depend on AMPH entry into the cell and are blocked by the DAT inhibitor cocaine. AMPH also stimulates cAMP accumulation and PKA-dependent inactivation of RhoA, thus providing a mechanism whereby PKA- and RhoA-dependent signaling pathways can interact to regulate the timing and robustness of AMPH’s effects on DAT internalization. Consistent with this model, the activation of D1/D5 receptors that couple to PKA in dopamine neurons antagonizes RhoA activation, DAT internalization, and hyperlocomotion observed in mice after AMPH treatment. These observations support the existence of an unanticipated intracellular target that mediates the effects of AMPH on RhoA and cAMP signaling and suggest new pathways to target to disrupt AMPH action. PMID:26553986

  6. Measurement of Exclusive $\\rho^{0}\\rho^{0}$ Production in Mid-Virtuality Two-Photon Interactions at LEP

    CERN Document Server

    Achard, P.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M.G.; Anderhub, H.; Andreev, Valery P.; Anselmo, F.; Arefev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S.V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillere, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B.L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J.J.; Blyth, S.C.; Bobbink, G.J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J.G.; Brochu, F.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y.H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G.M.; Chen, H.F.; Chen, H.S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; de Asmundis, R.; Deglon, P.; Debreczeni, J.; Degre, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M.T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F.J.; Extermann, P.; Falagan, M.A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J.H.; Filthaut, F.; Fisher, P.H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Iouri; Ganguli, S.N.; Garcia-Abia, Pablo; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z.F.; Grenier, Gerald Jean; Grimm, O.; Gruenewald, M.W.; Guida, M.; Gupta, V.K.; Gurtu, A.; Gutay, L.J.; Haas, D.; Hatzifotiadou, D.; Hebbeker, T.; Herve, Alain; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S.R.; Jin, B.N.; Jindal, P.; Jones, Lawrence W.; de Jong, P.; Josa-Mutuberria, I.; Kaur, M.; Kienzle-Focacci, M.N.; Kim, J.K.; Kirkby, Jasper; Kittel, W.; Klimentov, A.; Konig, A.C.; Kopal, M.; Koutsenko, V.; Kraber, M.; Kraemer, R.W.; Kruger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J.M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C.H.; Lin, W.T.; Linde, F.L.; Lista, L.; Liu, Z.A.; Lohmann, W.; Longo, E.; Lu, Y.S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W.G.; Malgeri, L.; Malinin, A.; Mana, C.; Mans, J.; Martin, J.P.; Marzano, F.; Mazumdar, K.; McNeil, R.R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W.J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G.B.; Muanza, G.S.; Muijs, A.J.M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Kluge, Hannelies; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, Thomas Cantzon; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroue, P.A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, Mohammad Azizur; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, Keith; Roe, B.P.; Romero, L.; Rosca, A.; Rosemann, C.; Rosenbleck, C.; Rosier-Lees, S.; Roth, Stefan; Rubio, J.A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schafer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D.J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D.P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L.Z.; Sushkov, S.; Suter, H.; Swain, J.D.; Szillasi, Z.; Tang, X.W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, Charles; Ting, Samuel C.C.; Ting, S.M.; Tonwar, S.C.; Toth, J.; Tully, C.; Tung, K.L.; Ulbricht, J.; Valente, E.; Van de Walle, R.T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobev, I.; Vorobyov, A.A.; Wadhwa, M.; Wang, Q.; Wang, X.L.; Wang, Z.M.; Weber, M.; Wynhoff, S.; Xia, L.; Xu, Z.Z.; Yamamoto, J.; Yang, B.Z.; Yang, C.G.; Yang, H.J.; Yang, M.; Yeh, S.C.; Zalite, An.; Zalite, Yu.; Zhang, Z.P.; Zhao, J.; Zhu, G.Y.; Zhu, R.Y.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.; Zoller, M.

    2004-01-01

    Exclusive rho^0 rho^0 production in two-photon collisions between a quasi-real and a mid-virtuality photon is studied with data collected at LEP at centre-of-mass energies 183GeV rho^0 rho^0 is determined as a function of the photon virtuality, q^2, and the two-photon centre-of-mass energy, Wgg, in the kinematic region: 0.2GeV^2 < q^2 < 0.85GeV^2 and 1.1GeV < Wgg < 3GeV.

  7. β-Catenin is required for intrinsic but not extrinsic BCR-ABL1 kinase-independent resistance to tyrosine kinase inhibitors in chronic myeloid leukemia.

    Science.gov (United States)

    Eiring, A M; Khorashad, J S; Anderson, D J; Yu, F; Redwine, H M; Mason, C C; Reynolds, K R; Clair, P M; Gantz, K C; Zhang, T Y; Pomicter, A D; Kraft, I L; Bowler, A D; Johnson, K; Partlin, M Mac; O'Hare, T; Deininger, M W

    2015-12-01

    Activation of nuclear β-catenin and expression of its transcriptional targets promotes chronic myeloid leukemia (CML) progression, tyrosine kinase inhibitor (TKI) resistance, and leukemic stem cell self-renewal. We report that nuclear β-catenin has a role in leukemia cell-intrinsic but not -extrinsic BCR-ABL1 kinase-independent TKI resistance. Upon imatinib inhibition of BCR-ABL1 kinase activity, β-catenin expression was maintained in intrinsically resistant cells grown in suspension culture and sensitive cells cultured in direct contact (DC) with bone marrow (BM) stromal cells. Thus, TKI resistance uncouples β-catenin expression from BCR-ABL1 kinase activity. In β-catenin reporter assays, intrinsically resistant cells showed increased transcriptional activity versus parental TKI-sensitive controls, and this was associated with restored expression of β-catenin target genes. In contrast, DC with BM stromal cells promoted TKI resistance, but had little effects on Lef/Tcf reporter activity and no consistent effects on cytoplasmic β-catenin levels, arguing against a role for β-catenin in extrinsic TKI resistance. N-cadherin or H-cadherin blocking antibodies abrogated DC-based resistance despite increasing Lef/Tcf reporter activity, suggesting that factors other than β-catenin contribute to extrinsic, BM-derived TKI resistance. Our data indicate that, while nuclear β-catenin enhances survival of intrinsically TKI-resistant CML progenitors, it is not required for extrinsic resistance mediated by the BM microenvironment.

  8. Allosteric inhibition enhances the efficacy of ABL kinase inhibitors to target unmutated BCR-ABL and BCR-ABL-T315I

    Directory of Open Access Journals (Sweden)

    Mian Afsar

    2012-09-01

    Full Text Available Abstract Background Chronic myelogenous leukemia (CML and Philadelphia chromosome-positive (Ph+ acute lymphatic leukemia (Ph + ALL are caused by the t(9;22, which fuses BCR to ABL resulting in deregulated ABL-tyrosine kinase activity. The constitutively activated BCR/ABL-kinase “escapes” the auto-inhibition mechanisms of c-ABL, such as allosteric inhibition. The ABL-kinase inhibitors (AKIs Imatinib, Nilotinib or Dasatinib, which target the ATP-binding site, are effective in Ph + leukemia. Another molecular therapy approach targeting BCR/ABL restores allosteric inhibition. Given the fact that all AKIs fail to inhibit BCR/ABL harboring the ‘gatekeeper’ mutation T315I, we investigated the effects of AKIs in combination with the allosteric inhibitor GNF2 in Ph + leukemia. Methods The efficacy of this approach on the leukemogenic potential of BCR/ABL was studied in Ba/F3 cells, primary murine bone marrow cells, and untransformed Rat-1 fibroblasts expressing BCR/ABL or BCR/ABL-T315I as well as in patient-derived long-term cultures (PDLTC from Ph + ALL-patients. Results Here, we show that GNF-2 increased the effects of AKIs on unmutated BCR/ABL. Interestingly, the combination of Dasatinib and GNF-2 overcame resistance of BCR/ABL-T315I in all models used in a synergistic manner. Conclusions Our observations establish a new approach for the molecular targeting of BCR/ABL and its resistant mutants using a combination of AKIs and allosteric inhibitors.

  9. Dynamic changes in neurexins' alternative splicing: role of Rho-associated protein kinases and relevance to memory formation.

    Directory of Open Access Journals (Sweden)

    Gabriela Rozic

    Full Text Available The three neurexins genes (NRXN1/2/3 encode polymorphic synaptic membrane proteins that are involved in cognitive functioning. Neurexins' selectivity of function is presumably conferred through differential use of 2 promoters and 5 alternative splicing sites (SS#1/2/3/4/5. In day-old rat brain neurons grown in culture, activation (depolarization induces reversible, calcium dependent, repression of NRXN2α SS#3 insert. The effects of depolarization on NRXN1/2/3α splicing and biochemical pathways mediating them were further studied in these neurons. NRXN1/2/3α splicing in the course of memory formation in vivo was also explored, using fear conditioning paradigm in rats in which the animals were trained to associate an aversive stimulus (electrical shock with a neutral context (a tone, resulting in the expression of fear responses to the neutral context.In the cultured neurons depolarization induced, beside NRXN2α SS#3, repression of SS#3 and SS#4 exons in NRXN3α but not NRXN1α. The repressions were mediated by the calcium/protein kinase C/Rho-associated protein kinase (ROCK pathway. Fear conditioning induced significant and transient repressions of the NRXN1/2/3α SS#4 exons in the rat hippocampus. ROCK inhibition prior to training attenuated the behavioral fear response, the NRXN1/2/3α splicing repressions and subsequent recovery and the levels of excitatory (PSD95 and inhibitory (gephyrin synaptic proteins in the hippocampus. No such effects were observed in the prefrontal cortex. Significant correlations existed between the fear response and hippocampal NRXN3α and NRXN2α SS#4 inserts as well as PSD95 protein levels. Hippocampal NRXN1α SS#4 insert and gephyrin levels did not correlate with the behavioral response but were negatively correlated with each other.These results show for the first time dynamic, experience related changes in NRXN1/2/3α alternative splicing in the rat brain and a role for ROCK in them. Specific neurexins

  10. Low dose of kaempferol suppresses the migration and invasion of triple-negative breast cancer cells by downregulating the activities of RhoA and Rac1.

    Science.gov (United States)

    Li, Shoushan; Yan, Ting; Deng, Rong; Jiang, Xuesong; Xiong, Huaping; Wang, Yuan; Yu, Qiao; Wang, Xiaohua; Chen, Cheng; Zhu, Yichao

    2017-01-01

    Triple-negative breast cancer (TNBC) is an especially aggressive and hard-to-treat disease. Although the anticancer role of kaempferol has been reported in breast cancer, the effect of kaempferol on TNBC remains unclear. This experiment investigated the migration-suppressive role of a low dose of kaempferol in TNBC cells. Wound-healing assays and cell invasion assays were used to confirm the migration and invasion of cells treated with kaempferol or transfected indicated constructs. We evaluated the activations of RhoA, Rac1 and Cdc42 in TNBC cells with a Rho activation assay. A panel of inhibitors of estrogen receptor/progesterone receptor/human epidermal growth factor receptor 2 (ER/PR/HER2) treated non-TNBC (SK-BR-3 and MCF-7) cells and blocked the ER/PR/HER2 activity. Wound-healing assays and Rho activation assays were employed to measure the effect of kaempferol and ER/PR/HER2 inhibitors on Rho activation and cell migration rates. A low dose of kaempferol (20 μmol/L) had a potent inhibitory effect on the migration and invasion of TNBC cells, but not on the migration of non-TNBC (SK-BR-3 and MCF-7) cells. The low dose of kaempferol downregulated the activations of RhoA and Rac1 in TNBC cells. Moreover, the low dose of kaempferol also inhibited the migration and RhoA activations of HER2-silence SK-BR-3 and ER/PR-silence MCF-7 cells. Overexpressed HER2 rescued the cell migration and RhoA and Rac1 activations of kaempferol-treated MDA-MB-231 cells. The low dose of kaempferol inhibits the migration and invasion of TNBC cells via blocking RhoA and Rac1 signaling pathway.

  11. Receptor tyrosine kinase (c-Kit inhibitors: a potential therapeutic target in cancer cells

    Directory of Open Access Journals (Sweden)

    Abbaspour Babaei M

    2016-08-01

    Full Text Available Maryam Abbaspour Babaei,1 Behnam Kamalidehghan,2,3 Mohammad Saleem,4–6 Hasniza Zaman Huri,1,7 Fatemeh Ahmadipour1 1Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia; 2Department of Medical Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB, Shahrak-e Pajoohesh, 3Medical Genetics Department, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 4Department of Urology, 5Department of Laboratory Medicine and Pathology, Masonic Cancer Center, University of Minnesota, 6Section of Molecular Therapeutics & Cancer Health Disparity, The Hormel Institute, Austin, MN, USA; 7Clinical Investigation Centre, University Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, Malaysia Abstract: c-Kit, a receptor tyrosine kinase, is involved in intracellular signaling, and the mutated form of c-Kit plays a crucial role in occurrence of some cancers. The function of c-Kit has led to the concept that inhibiting c-Kit kinase activity can be a target for cancer therapy. The promising results of inhibition of c-Kit for treatment of cancers have been observed in some cancers such as gastrointestinal stromal tumor, acute myeloid leukemia, melanoma, and other tumors, and these results have encouraged attempts toward improvement of using c-Kit as a capable target for cancer therapy. This paper presents the findings of previous studies regarding c-Kit as a receptor tyrosine kinase and an oncogene, as well as its gene targets and signaling pathways in normal and cancer cells. The c-Kit gene location, protein structure, and the role of c-Kit in normal cell have been discussed. Comprehending the molecular mechanism underlying c-Kit-mediated tumorogenesis is consequently essential and may lead to the identification of future novel drug targets. The potential mechanisms by which c-Kit induces cellular transformation have been described. This study aims to elucidate the function of c

  12. Cyclooxygenase inhibitors potentiate receptor tyrosine kinase therapies in bladder cancer cells in vitro

    Directory of Open Access Journals (Sweden)

    Bourn J

    2018-06-01

    Full Text Available Jennifer Bourn,1,2 Maria Cekanova1,2 1Department of Small Animal Clinical Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN, USA; 2UT-ORNL Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, TN, USA Purpose: Receptor tyrosine kinase inhibitors (RTKIs are used as targeted therapies for patients diagnosed with cancer with highly expressed receptor tyrosine kinases (RTKs, including the platelet-derived growth factor receptor (PDGFR and c-Kit receptor. Resistance to targeted therapies is partially due to the activation of alternative pro-survival signaling pathways, including cyclooxygenase (COX-2. In this study, we validated the effects of two RTKIs, axitinib and AB1010, in combination with COX inhibitors on the V-akt murine thymoma oncogene homolog 1 (Akt and COX-2 signaling pathways in bladder cancer cells.Methods: The expression of several RTKs and their downstream signaling targets was analyzed by Western blot (WB analysis in human and canine bladder transitional cell carcinoma (TCC cell lines. The effects of RTKIs and COX inhibitors in bladder TCC cells were assessed by MTS for cell viability, by Caspase-3/7 and Annexin V assay for apoptosis, by WB analysis for detection of COX-2 and Akt signaling pathways, and by enzyme-linked immunosorbent assay for detection of prostaglandin E2 (PGE2 levels.Results: All tested TCC cells expressed the c-Kit and PDGFRα receptors, except human 5637 cells that had low RTKs expression. In addition, all tested cells expressed COX-1, COX-2, Akt, extracellular signal regulated kinases 1/2, and nuclear factor kappa-light-chain-enhance of activated B cells proteins, except human UM-UC-3 cells, where no COX-2 expression was detected by WB analysis. Both RTKIs inhibited cell viability and increased apoptosis in a dose-dependent manner in tested bladder TCC cells, which positively correlated with their expression levels of the PDGFRα and c

  13. Expression pattern and function of tyrosine receptor kinase B isoforms in rat mesenteric arterial smooth muscle cells

    International Nuclear Information System (INIS)

    Otani, Kosuke; Okada, Muneyoshi; Yamawaki, Hideyuki

    2015-01-01

    Tyrosine receptor kinaseB (TrkB) is a high affinity receptor for brain-derived neurotrophic factor (BDNF). TrkB isoforms involve full length TrkB (TrkB FL) and truncated TrkB type1 (TrkB T1) and type 2 (TrkB T2) in rats. The aim of present study was to explore their expression pattern and function in mesenteric arterial smooth muscle cells (MASMCs). The expression of TrkB isoform protein and mRNA was examined by Western blotting, immunofluorescence and quantitative RT-PCR analyses. Cell proliferation was measured by a bromodeoxyuridine (BrdU) incorporation assay. Cell migration was measured by a Boyden chamber assay. Cell morphology was observed with a phase-contrast microscope. Protein and mRNA expression of BDNF and TrkB isoforms was confirmed in MASMCs. Expression level of TrkB FL was less, while that of TrkB T1 was the highest in MASMCs. Although BDNF increased phosphorylation of ERK, it had no influence on migration and proliferation of MASMCs. TrkB T1 gene knockdown by a RNA interference induced morphological changes and reduced expression level of α-smooth muscle actin (α-SMA) in MASMCs. Similar morphological changes and reduced α-SMA expression were induced in MASMCs by a Rho kinase inhibitor, Y-27632. In conclusion, we for the first time demonstrate that TrkB T1 expressed highly in MASMCs contributes to maintain normal cell morphology possibly via regulation of Rho activity. This study firstly defined expression level of TrkB isoforms and partly revealed their functions in peripheral vascular cells. - Highlights: • BDNF-TrkB axis mediates neurogenesis, growth, differentiation and survival. • Expression pattern and function of TrkB in vascular smooth muscle remain unclear. • Expression of TrkB FL is low, while that of TrkB T1 is the highest. • TrkB T1 contributes to maintain normal morphology possibly via activating Rho.

  14. Expression pattern and function of tyrosine receptor kinase B isoforms in rat mesenteric arterial smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Otani, Kosuke; Okada, Muneyoshi; Yamawaki, Hideyuki, E-mail: yamawaki@vmas.kitasato-u.ac.jp

    2015-11-27

    Tyrosine receptor kinaseB (TrkB) is a high affinity receptor for brain-derived neurotrophic factor (BDNF). TrkB isoforms involve full length TrkB (TrkB FL) and truncated TrkB type1 (TrkB T1) and type 2 (TrkB T2) in rats. The aim of present study was to explore their expression pattern and function in mesenteric arterial smooth muscle cells (MASMCs). The expression of TrkB isoform protein and mRNA was examined by Western blotting, immunofluorescence and quantitative RT-PCR analyses. Cell proliferation was measured by a bromodeoxyuridine (BrdU) incorporation assay. Cell migration was measured by a Boyden chamber assay. Cell morphology was observed with a phase-contrast microscope. Protein and mRNA expression of BDNF and TrkB isoforms was confirmed in MASMCs. Expression level of TrkB FL was less, while that of TrkB T1 was the highest in MASMCs. Although BDNF increased phosphorylation of ERK, it had no influence on migration and proliferation of MASMCs. TrkB T1 gene knockdown by a RNA interference induced morphological changes and reduced expression level of α-smooth muscle actin (α-SMA) in MASMCs. Similar morphological changes and reduced α-SMA expression were induced in MASMCs by a Rho kinase inhibitor, Y-27632. In conclusion, we for the first time demonstrate that TrkB T1 expressed highly in MASMCs contributes to maintain normal cell morphology possibly via regulation of Rho activity. This study firstly defined expression level of TrkB isoforms and partly revealed their functions in peripheral vascular cells. - Highlights: • BDNF-TrkB axis mediates neurogenesis, growth, differentiation and survival. • Expression pattern and function of TrkB in vascular smooth muscle remain unclear. • Expression of TrkB FL is low, while that of TrkB T1 is the highest. • TrkB T1 contributes to maintain normal morphology possibly via activating Rho.

  15. Assessment of response to beta-blockers by expression of βArr2 and RhoA/ROCK2 in antrum mucosa in cirrhotic patients

    DEFF Research Database (Denmark)

    Trebicka, Jonel; von Heydebrand, Matthias; Lehmann, Jennifer

    2016-01-01

    BACKGROUND & AIMS: Non-selective beta-blockers (NSBB) are first choice for prevention of variceal bleeding. But possible deleterious effects in refractory ascites and frequent non-response are clinical drawbacks. Since levels of vasoactive proteins in antrum mucosa reflect vascular dysfunction...... and protein expression of Ras homolog family member A (RhoA), Rho-kinase (ROCK)2, beta-arrestin2 (βArr2), endothelial nitric oxide synthase (eNOS) and the phosphorylation of downstream effectors VASP and moesin were analyzed using PCR and Western blot. Further 21 patients on NSBB were evaluated...

  16. ESCMID Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biological therapies: an infectious diseases perspective (Intracellular signaling pathways: tyrosine kinase and mTOR inhibitors).

    Science.gov (United States)

    Reinwald, M; Silva, J T; Mueller, N J; Fortún, J; Garzoni, C; de Fijter, J W; Fernández-Ruiz, M; Grossi, P; Aguado, J M

    2018-06-01

    The present review is part of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biologic therapies. To review, from an infectious diseases perspective, the safety profile of therapies targeting different intracellular signaling pathways and to suggest preventive recommendations. Computer-based Medline searches with MeSH terms pertaining to each agent or therapeutic family. Although BCR-ABL tyrosine kinase inhibitors modestly increase the overall risk of infection, dasatinib has been associated with cytomegalovirus and hepatitis B virus reactivation. BRAF/MEK kinase inhibitors do not significantly affect infection susceptibility. The effect of Bruton tyrosine kinase inhibitors (ibrutinib) among patients with B-cell malignancies is difficult to distinguish from that of previous immunosuppression. However, cases of Pneumocystis jirovecii pneumonia (PCP), invasive fungal infection and progressive multifocal leukoencephalopathy have been occasionally reported. Because phosphatidylinositol-3-kinase inhibitors (idelalisib) may predispose to opportunistic infections, anti-Pneumocystis prophylaxis and prevention strategies for cytomegalovirus are recommended. No increased rates of infection have been observed with venetoclax (antiapoptotic protein Bcl-2 inhibitor). Therapy with Janus kinase inhibitors markedly increases the incidence of infection. Pretreatment screening for chronic hepatitis B virus and latent tuberculosis infection must be performed, and anti-Pneumocystis prophylaxis should be considered for patients with additional risk factors. Cancer patients receiving mTOR inhibitors face an increased incidence of overall infection, especially those with additional risk factors (prior therapies or delayed wound healing). Specific preventive approaches are warranted in view of the increased risk of infection associated with some of the

  17. Protective effect of the poly(ADP-ribose polymerase inhibitor PJ34 on mitochondrial depolarization-mediated cell death in hepatocellular carcinoma cells involves attenuation of c-Jun N-terminal kinase-2 and protein kinase B/Akt activation

    Directory of Open Access Journals (Sweden)

    Radnai Balazs

    2012-05-01

    Full Text Available Abstract Background 2,4-Dimethoxyphenyl-E-4-arylidene-3-isochromanone (IK11 was previously described to induce apoptotic death of A431 tumor cells. In this report, we investigated the molecular action of IK11 in the HepG2 human hepatocellular carcinoma cell line to increase our knowledge of the role of poly (ADP-ribose-polymerase (PARP, protein kinase B/Akt and mitogen activated protein kinase (MAPK activation in the survival and death of tumor cells and to highlight the possible role of PARP-inhibitors in co-treatments with different cytotoxic agents in cancer therapy. Results We found that sublethal concentrations of IK11 prevented proliferation, migration and entry of the cells into their G2 phase. At higher concentrations, IK11 induced reactive oxygen species (ROS production, mitochondrial membrane depolarization, activation of c-Jun N-terminal kinase 2 (JNK2, and substantial loss of HepG2 cells. ROS production appeared marginal in mediating the cytotoxicity of IK11 since N-acetyl cysteine was unable to prevent it. However, the PARP inhibitor PJ34, although not a ROS scavenger, strongly inhibited both IK11-induced ROS production and cell death. JNK2 activation seemed to be a major mediator of the effect of IK11 since inhibition of JNK resulted in a substantial cytoprotection while inhibitors of the other kinases failed to do so. Inhibition of Akt slightly diminished the effect of IK11, while the JNK and Akt inhibitor and ROS scavenger trans-resveratrol completely protected against it. Conclusions These results indicate significant involvement of PARP, a marginal role of ROS and a pro-apoptotic role of Akt in this system, and raise attention to a novel mechanism that should be considered when cancer therapy is augmented with PARP-inhibition, namely the cytoprotection by inhibition of JNK2.

  18. Differential Effects of Phosphatidylinositol 4-Kinase (PI4K and 3-Kinase (PI3K Inhibitors on Stomatal Responses to Environmental Signals

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    Koh Iba

    2017-05-01

    Full Text Available Specific cellular components including products of phosphatidylinositol (PI metabolism play an important role as signaling molecules in stomatal responses to environmental signals. In this study, pharmacological inhibitors of a set of cellular components, including PI4-kinase (PI4K and PI3K, were used to investigate stomatal closure in response to CO2, darkness, and abscisic acid (ABA. Treatment with PAO, a specific inhibitor of PI4K, specifically inhibited the stomatal response to CO2 compared with that to darkness and ABA. In contrast, treatment with LY294002, a PI3K-specific inhibitor, specifically inhibited the stomatal response to darkness compared with that to CO2 and ABA. The specific inhibitory effects of PAO and LY294002 were also observed as changes in the spatial density of dot-like structures labeled by green fluorescent protein-tagged PATROL1, a protein that controls stomatal aperture possibly via regulation of H+-ATPase amount in guard cell plasma membranes. Our results suggest an important role for PI4K and PI3K in the CO2 and darkness signal transduction pathways, respectively, that mediate PATROL1 dynamics.

  19. Chiral symmetry breaking and the spin content of the {rho} and {rho}{sup '} mesons

    Energy Technology Data Exchange (ETDEWEB)

    Glozman, L.Ya., E-mail: leonid.glozman@uni-graz.at [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria); Lang, C.B., E-mail: christian.lang@uni-graz.at [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria); Limmer, M., E-mail: markus.limmer@uni-graz.at [Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria)

    2011-11-03

    Using interpolators with different SU(2){sub L}xSU(2){sub R} transformation properties we study the chiral symmetry and spin contents of the {rho} and {rho}{sup '} mesons in lattice simulations with dynamical quarks. A ratio of couplings of the q-bar {gamma}{sup i}{tau}q and q-bar {sigma}{sup 0}i{tau}q interpolators to a given meson state at different resolution scales tells one about the degree of chiral symmetry breaking in the meson wave function at these scales. Using a Gaussian gauge invariant smearing of the quark fields in the interpolators, we are able to extract the chiral content of mesons up to the infrared resolution of {approx}1 fm. In the ground state {rho} meson the chiral symmetry is strongly broken with comparable contributions of both the (0,1)+(1,0) and (1/2,1/2){sub b} chiral representations with the former being the leading contribution. In contrast, in the {rho}{sup '} meson the degree of chiral symmetry breaking is manifestly smaller and the leading representation is (1/2,1/2){sub b}. Using a unitary transformation from the chiral basis to the {sup 2S+1}L{sub J} basis, we are able to define and measure the angular momentum content of mesons in the rest frame. This definition is different from the traditional one which uses parton distributions in the infinite momentum frame. The {rho} meson is practically a {sup 3}S{sub 1} state with no obvious trace of a 'spin crisis'. The {rho}{sup '} meson has a sizeable contribution of the {sup 3}D{sub 1} wave, which implies that the {rho}{sup '} meson cannot be considered as a pure radial excitation of the {rho} meson.

  20. Placenta-specific novel splice variants of Rho GDP dissociation inhibitor β are highly expressed in cancerous cells

    Directory of Open Access Journals (Sweden)

    Hatakeyama Keiichi

    2012-12-01

    Full Text Available Abstract Background Alternative splicing of pre-mRNA transcripts not only plays a role in normal molecular processes but is also associated with cancer development. While normal transcripts are ubiquitously expressed in normal tissues, splice variants created through abnormal alternative splicing events are often expressed in cancer cells. Although the Rho GDP dissociation inhibitor β (ARHGDIB gene has been found to be ubiquitously expressed in normal tissues and involved in cancer development, the presence of splice variants of ARHGDIB has not yet been investigated. Results Validation analysis for the presence of and exon structures of splice variants of ARHGDIB, performed using reverse-transcriptase polymerase chain reaction and DNA sequencing, successfully identified novel splice variants of ARHGDIB, that is, 6a, 6b, and 6c, in colon, pancreas, stomach, and breast cancer cell lines. Quantitative real-time polymerase chain reaction analysis showed that these variants were also highly expressed in normal placental tissue but not in other types of normal tissue. Conclusions Expression of ARHGDIB variants 6a, 6b, and 6c appears to be restricted to cancer cells and normal placental tissue, suggesting that these variants possess cancer-specific functions and, as such, are potential cancer-related biomarkers.

  1. EXPERIMENT ON EFFECTS OF LOE-PROTEIN DIET SUPPLEMENTED WITH α-KETOACIDS ON HYPERTROPHY OF DIABETIC GLOMERULUS AND ITS RELATIONSHIP WITH THE LEVEL OF CYCLIN KINASE INHIBITOR P27

    OpenAIRE

    Zhou, Yi; Yuan, Weijie; Dong, Ting; Wang, Ling

    2012-01-01

    Low-protein diet supplemented with α-keto acids was reported to have renoprotective roles in diabetic nephropathy via inhibiting glomerular hypertrophy, however, the mechanism has not yet been fully clarified. the cyclin kinase inhibitor p27 play an important role in hypertrophy of diabetic glomerulus, The objective of the present study was to investigate the relationship between the cyclin kinase inhibitor p27 and the effect of low-protein diet supplemented with α-keto acids on hypertrophy o...

  2. Oral protein kinase c β inhibition using ruboxistaurin

    DEFF Research Database (Denmark)

    Aiello, Lloyd Paul; Vignati, Louis; Sheetz, Matthew J

    2011-01-01

    To evaluate efficacy, safety, and causes of vision loss among 813 patients (1,392 eyes) with moderately severe to very severe nonproliferative diabetic retinopathy from the Protein Kinase C β Inhibitor-Diabetic Retinopathy Study and Protein Kinase C β Inhibitor-Diabetic Retinopathy Study 2 ruboxi...

  3. Safety and efficacy of the bumped kinase inhibitor BKI-1553 in pregnant sheep experimentally infected with Neospora caninum tachyzoites

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    Roberto Sánchez-Sánchez

    2018-04-01

    Full Text Available Neospora caninum is one of the main causes of abortion in cattle, and recent studies have highlighted its relevance as an abortifacient in small ruminants. Vaccines or drugs for the control of neosporosis are lacking. Bumped kinase inhibitors (BKIs, which are ATP-competitive inhibitors of calcium dependent protein kinase 1 (CDPK1, were shown to be highly efficacious against several apicomplexan parasites in vitro and in laboratory animal models. We here present the pharmacokinetics, safety and efficacy of BKI-1553 in pregnant ewes and foetuses using a pregnant sheep model of N. caninum infection. BKI-1553 showed exposure in pregnant ewes with trough concentrations of approximately 4 μM, and of 1  μM in foetuses. Subcutaneous BKI-1553 administration increased rectal temperatures shortly after treatment, and resulted in dermal nodules triggering a slight monocytosis after repeated doses at short intervals. BKI-1553 treatment decreased fever in infected pregnant ewes already after two applications, resulted in a 37–50% reduction in foetal mortality, and modulated immune responses; IFNγ levels were increased early after infection and IgG levels were reduced subsequently. N. caninum was abundantly found in placental tissues; however, parasite detection in foetal brain tissue decreased from 94% in the infected/untreated group to 69–71% in the treated groups. In summary, BKI-1553 confers partial protection against abortion in a ruminant experimental model of N. caninum infection during pregnancy. In addition, reduced parasite detection, parasite load and lesions in foetal brains were observed. Keywords: Neospora caninum, Sheep, Pregnancy, Treatment, Protein kinase inhibitor, BKI-1553

  4. Immunological changes with kinase inhibitor therapy for chronic lymphocytic leukemia.

    Science.gov (United States)

    Pleyer, Christopher; Wiestner, Adrian; Sun, Clare

    2018-05-15

    Ibrutinib and idelalisib are kinase inhibitors that have revolutionized the treatment of chronic lymphocytic leukemia (CLL). Capable of inducing durable remissions, these agents also modulate the immune system. Both ibrutinib and idelalisib abrogate the tumor-supporting microenvironment by disrupting cell-cell interactions, modulating the T-cell compartment, and altering the cytokine milieu. Ibrutinib also partially restores T-cell and myeloid defects associated with CLL. In contrast, immune-related adverse effects, including pneumonitis, colitis, hepatotoxicity, and infections are of particular concern with idelalisib. While opportunistic infections and viral reactivations occur with both ibrutinib and idelalisib, these complications are less common and less severe with ibrutinib, especially when used as monotherapy without additional immunosuppressive agents. This review discusses the impact of ibrutinib and idelalisib on the immune system, including infectious and auto-immune complications as well as their specific effects on the B-cell, T-cell, and myeloid compartment.

  5. Tumor-targeted Nanobullets: Anti-EGFR nanobody-liposomes loaded with anti-IGF-1R kinase inhibitor for cancer treatment.

    Science.gov (United States)

    van der Meel, Roy; Oliveira, Sabrina; Altintas, Isil; Haselberg, Rob; van der Veeken, Joris; Roovers, Rob C; van Bergen en Henegouwen, Paul M P; Storm, Gert; Hennink, Wim E; Schiffelers, Raymond M; Kok, Robbert J

    2012-04-30

    The epidermal growth factor receptor (EGFR) is a validated target for anti-cancer therapy and several EGFR inhibitors are used in the clinic. Over the years, an increasing number of studies have reported on the crosstalk between EGFR and other receptors that can contribute to accelerated cancer development or even acquisition of resistance to anti-EGFR therapies. Combined targeting of EGFR and insulin-like growth factor 1 receptor (IGF-1R) is a rational strategy to potentiate anti-cancer treatment and possibly retard resistance development. In the present study, we have pursued this by encapsulating the kinase inhibitor AG538 in anti-EGFR nanobody-liposomes. The thus developed dual-active nanobody-liposomes associated with EGFR-(over)expressing cells in an EGFR-specific manner and blocked both EGFR and IGF-1R activation, due to the presence of the EGFR-blocking nanobody EGa1 and the anti-IGF-1R kinase inhibitor AG538 respectively. AG538-loaded nanobody-liposomes induced a strong inhibition of tumor cell proliferation even upon short-term exposure followed by a drug-free wash-out period. Therefore, AG538-loaded nanobody-liposomes are a promising anti-cancer formulation due to efficient intracellular delivery of AG538 in combination with antagonistic and downregulating properties of the EGa1 nanobody-liposomes. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Alignment independent 3D-QSAR, quantum calculations and molecular docking of Mer specific tyrosine kinase inhibitors as anticancer drugs

    Directory of Open Access Journals (Sweden)

    Fereshteh Shiri

    2016-03-01

    Full Text Available Mer receptor tyrosine kinase is a promising novel cancer therapeutic target in many human cancers, because abnormal activation of Mer has been implicated in survival signaling and chemoresistance. 3D-QSAR analyses based on alignment independent descriptors were performed on a series of 81 Mer specific tyrosine kinase inhibitors. The fractional factorial design (FFD and the enhanced replacement method (ERM were applied and tested as variable selection algorithms for the selection of optimal subsets of molecular descriptors from a much greater pool of such regression variables. The data set was split into 65 molecules as the training set and 16 compounds as the test set. All descriptors were generated by using the GRid INdependent descriptors (GRIND approach. After variable selection, GRIND were correlated with activity values (pIC50 by PLS regression. Of the two applied variable selection methods, ERM had a noticeable improvement on the statistical parameters of PLS model, and yielded a q2 value of 0.77, an rpred2 of 0.94, and a low RMSEP value of 0.25. The GRIND information contents influencing the affinity on Mer specific tyrosine kinase were also confirmed by docking studies. In a quantum calculation study, the energy difference between HOMO and LUMO (gap implied the high interaction of the most active molecule in the active site of the protein. In addition, the molecular electrostatic potential energy at DFT level confirmed results obtained from the molecular docking. The identified key features obtained from the molecular modeling, enabled us to design novel kinase inhibitors.

  7. Alignment independent 3D-QSAR, quantum calculations and molecular docking of Mer specific tyrosine kinase inhibitors as anticancer drugs.

    Science.gov (United States)

    Shiri, Fereshteh; Pirhadi, Somayeh; Ghasemi, Jahan B

    2016-03-01

    Mer receptor tyrosine kinase is a promising novel cancer therapeutic target in many human cancers, because abnormal activation of Mer has been implicated in survival signaling and chemoresistance. 3D-QSAR analyses based on alignment independent descriptors were performed on a series of 81 Mer specific tyrosine kinase inhibitors. The fractional factorial design (FFD) and the enhanced replacement method (ERM) were applied and tested as variable selection algorithms for the selection of optimal subsets of molecular descriptors from a much greater pool of such regression variables. The data set was split into 65 molecules as the training set and 16 compounds as the test set. All descriptors were generated by using the GRid INdependent descriptors (GRIND) approach. After variable selection, GRIND were correlated with activity values (pIC50) by PLS regression. Of the two applied variable selection methods, ERM had a noticeable improvement on the statistical parameters of PLS model, and yielded a q (2) value of 0.77, an [Formula: see text] of 0.94, and a low RMSEP value of 0.25. The GRIND information contents influencing the affinity on Mer specific tyrosine kinase were also confirmed by docking studies. In a quantum calculation study, the energy difference between HOMO and LUMO (gap) implied the high interaction of the most active molecule in the active site of the protein. In addition, the molecular electrostatic potential energy at DFT level confirmed results obtained from the molecular docking. The identified key features obtained from the molecular modeling, enabled us to design novel kinase inhibitors.

  8. Identification of a novel multiple kinase inhibitor with potent antiviral activity against influenza virus by reducing viral polymerase activity

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Yutaka; Kakisaka, Michinori; Chutiwitoonchai, Nopporn [Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Tajima, Shigeru [Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640 (Japan); Hikono, Hirokazu; Saito, Takehiko [Influenza and Prion Disease Research Center, National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856 (Japan); Aida, Yoko, E-mail: aida@riken.jp [Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2014-07-18

    Highlights: • Screening of 50,000 compounds and subsequent lead optimization identified WV970. • WV970 has antiviral effects against influenza A, B and highly pathogenic viral strains. • WV970 inhibits viral genome replication and transcription. • A target database search suggests that WV970 may bind to a number of kinases. • KINOMEscan screening revealed that WV970 has inhibitory effects on 15 kinases. - Abstract: Neuraminidase inhibitors are the only currently available influenza treatment, although resistant viruses to these drugs have already been reported. Thus, new antiviral drugs with novel mechanisms of action are urgently required. In this study, we identified a novel antiviral compound, WV970, through cell-based screening of a 50,000 compound library and subsequent lead optimization. This compound exhibited potent antiviral activity with nanomolar IC{sub 50} values against both influenza A and B viruses but not non-influenza RNA viruses. Time-of-addition and indirect immunofluorescence assays indicated that WV970 acted at an early stage of the influenza life cycle, but likely after nuclear entry of viral ribonucleoprotein (vRNP). Further analyses of viral RNA expression and viral polymerase activity indicated that WV970 inhibited vRNP-mediated viral genome replication and transcription. Finally, structure-based virtual screening and comprehensive human kinome screening were used to demonstrate that WV970 acts as a multiple kinase inhibitor, many of which are associated with influenza virus replication. Collectively, these results strongly suggest that WV970 is a promising anti-influenza drug candidate and that several kinases associated with viral replication are promising drug targets.

  9. Identification of a novel multiple kinase inhibitor with potent antiviral activity against influenza virus by reducing viral polymerase activity

    International Nuclear Information System (INIS)

    Sasaki, Yutaka; Kakisaka, Michinori; Chutiwitoonchai, Nopporn; Tajima, Shigeru; Hikono, Hirokazu; Saito, Takehiko; Aida, Yoko

    2014-01-01

    Highlights: • Screening of 50,000 compounds and subsequent lead optimization identified WV970. • WV970 has antiviral effects against influenza A, B and highly pathogenic viral strains. • WV970 inhibits viral genome replication and transcription. • A target database search suggests that WV970 may bind to a number of kinases. • KINOMEscan screening revealed that WV970 has inhibitory effects on 15 kinases. - Abstract: Neuraminidase inhibitors are the only currently available influenza treatment, although resistant viruses to these drugs have already been reported. Thus, new antiviral drugs with novel mechanisms of action are urgently required. In this study, we identified a novel antiviral compound, WV970, through cell-based screening of a 50,000 compound library and subsequent lead optimization. This compound exhibited potent antiviral activity with nanomolar IC 50 values against both influenza A and B viruses but not non-influenza RNA viruses. Time-of-addition and indirect immunofluorescence assays indicated that WV970 acted at an early stage of the influenza life cycle, but likely after nuclear entry of viral ribonucleoprotein (vRNP). Further analyses of viral RNA expression and viral polymerase activity indicated that WV970 inhibited vRNP-mediated viral genome replication and transcription. Finally, structure-based virtual screening and comprehensive human kinome screening were used to demonstrate that WV970 acts as a multiple kinase inhibitor, many of which are associated with influenza virus replication. Collectively, these results strongly suggest that WV970 is a promising anti-influenza drug candidate and that several kinases associated with viral replication are promising drug targets

  10. Exploiting polypharmacology for improving therapeutic outcome of kinase inhibitors (KIs): An update of recent medicinal chemistry efforts.

    Science.gov (United States)

    Ma, Xiaodong; Lv, Xiaoqing; Zhang, Jiankang

    2018-01-01

    Polypharmacology has been increasingly advocated for the therapeutic intervention in complex pathological conditions, exemplified by cancer. Although kinase inhibitors (KIs) have revolutionized the treatment for certain types of malignancies, some major medical needs remain unmet due to the relentless advance of drug resistance and insufficient efficacy of mono-target KIs. Hence, "multiple targets, multi-dimensional activities" represents an emerging paradigm for innovative anti-cancer drug discovery. Over recent years, considerable leaps have been made in pursuit of kinase-centric polypharmacological anti-cancer therapeutics, providing avenues to tackling the limitation of mono-target KIs. In the review, we summarize the clinically important mechanisms inducing KI resistance and depict a landscape of recent medicinal chemistry efforts on exploring kinase-centric polypharmacological anti-cancer agents that targeting multiple cancer-related processes. In parallel, some inevitable challenges are emphasized for the sake of more accurate and efficient drug discovery in the field. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. Molecular modeling-driven approach for identification of Janus kinase 1 inhibitors through 3D-QSAR, docking and molecular dynamics simulations.

    Science.gov (United States)

    Itteboina, Ramesh; Ballu, Srilata; Sivan, Sree Kanth; Manga, Vijjulatha

    2017-10-01

    Janus kinase 1 (JAK 1) belongs to the JAK family of intracellular nonreceptor tyrosine kinase. JAK-signal transducer and activator of transcription (JAK-STAT) pathway mediate signaling by cytokines, which control survival, proliferation and differentiation of a variety of cells. Three-dimensional quantitative structure activity relationship (3 D-QSAR), molecular docking and molecular dynamics (MD) methods was carried out on a dataset of Janus kinase 1(JAK 1) inhibitors. Ligands were constructed and docked into the active site of protein using GLIDE 5.6. Best docked poses were selected after analysis for further 3 D-QSAR analysis using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methodology. Employing 60 molecules in the training set, 3 D-QSAR models were generate that showed good statistical reliability, which is clearly observed in terms of r 2 ncv and q 2 loo values. The predictive ability of these models was determined using a test set of 25 molecules that gave acceptable predictive correlation (r 2 Pred ) values. The key amino acid residues were identified by means of molecular docking, and the stability and rationality of the derived molecular conformations were also validated by MD simulation. The good consonance between the docking results and CoMFA/CoMSIA contour maps provides helpful clues about the reasonable modification of molecules in order to design more efficient JAK 1 inhibitors. The developed models are expected to provide some directives for further synthesis of highly effective JAK 1 inhibitors.

  12. Autoregulation of kinase dephosphorylation by ATP binding in AGC protein kinases.

    Science.gov (United States)

    Chan, Tung O; Pascal, John M; Armen, Roger S; Rodeck, Ulrich

    2012-02-01

    AGC kinases, including the three Akt (protein kinase B) isoforms, protein kinase A (PKA) and all protein kinase C (PKC) isoforms, require activation loop phosphorylation (threonine 308 in Akt1) as well as phosphorylation of a C-terminal residue (serine 473 in Akt1) for catalytic activity and phosphorylation of downstream targets. Conversely, phosphatases reverse these phosphorylations. Virtually all cellular processes are affected by AGC kinases, a circumstance that has led to intense scrutiny of the molecular mechanisms that regulate phosphorylation of these kinases. Here, we review a new layer of control of phosphorylation in Akt, PKA and PKC pointing to ATP binding pocket occupancy as a means to decelerate dephosphorylation of these and, potentially, other kinases. This additional level of kinase regulation opens the door to search for new functional motifs for the rational design of non- ATP-competitive kinase inhibitors that discriminate within and between protein kinase families.

  13. Patients harboring EGFR mutation after primary resistance to crizotinib and response to EGFR-tyrosine kinase inhibitor

    Directory of Open Access Journals (Sweden)

    Wang WX

    2016-01-01

    Full Text Available Wenxian Wang,1 Xiaowen Jiang,1 Zhengbo Song,1,2 Yiping Zhang1,2 1Department of Chemotherapy, Zhejiang Cancer Hospital, 2Key Laboratory Diagnosis and Treatment Technology on Thoracic Oncology, Hangzhou, Zhejiang, People’s Republic of China Abstract: Anaplastic lymphoma kinase (ALK rearrangement lung cancer responds to ALK tyrosine kinase inhibitors. It is known that many cases ultimately acquired resistance to crizotinib. However, a case of primary resistance is rare. We present a case of harboring exon 19 deletion in epidermal growth factor receptor in ALK rearranged lung adenocarcinoma, who experienced a partial tumor response to icotinib after failure with crizotinib therapy and chemotherapy. Considering the partial response, we conclude that it is important to find the cause of resistance to crizotinib. We detected gene mutations with plasma by the next-generation sequencing; the next-generation sequencing demonstrates an attractive system to identify mutations improving the outcome of patients with a deadly disease. Keywords: non-small cell lung cancer, anaplastic lymphoma kinase, crizotinib, epidermal growth factor receptor

  14. Furan-2-ylmethylene thiazolidinediones as novel, potent, and selective inhibitors of phosphoinositide 3-kinase gamma.

    Science.gov (United States)

    Pomel, Vincent; Klicic, Jasna; Covini, David; Church, Dennis D; Shaw, Jeffrey P; Roulin, Karen; Burgat-Charvillon, Fabienne; Valognes, Delphine; Camps, Montserrat; Chabert, Christian; Gillieron, Corinne; Françon, Bernard; Perrin, Dominique; Leroy, Didier; Gretener, Denise; Nichols, Anthony; Vitte, Pierre Alain; Carboni, Susanna; Rommel, Christian; Schwarz, Matthias K; Rückle, Thomas

    2006-06-29

    Class I phosphoinositide 3-kinases (PI3Ks), in particular PI3Kgamma, have become attractive drug targets for inflammatory and autoimmune diseases. Here, we disclose a novel series of furan-2-ylmethylene thiazolidinediones as selective, ATP-competitive PI3Kgamma inhibitors. Structure-based design and X-ray crystallography of complexes formed by inhibitors bound to PI3Kgamma identified key pharmacophore features for potency and selectivity. An acidic NH group on the thiazolidinedione moiety and a hydroxy group on the furan-2-yl-phenyl part of the molecule play crucial roles in binding to PI3K and contribute to class IB PI3K selectivity. Compound 26 (AS-252424), a potent and selective small-molecule PI3Kgamma inhibitor emerging from these efforts, was further profiled in three different cellular PI3K assays and shown to be selective for class IB PI3K-mediated cellular effects. Oral administration of 26 in a mouse model of acute peritonitis led to a significant reduction of leukocyte recruitment.

  15. PKI-179: an orally efficacious dual phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) inhibitor.

    Science.gov (United States)

    Venkatesan, Aranapakam M; Chen, Zecheng; dos Santos, Osvaldo; Dehnhardt, Christoph; Santos, Efren Delos; Ayral-Kaloustian, Semiramis; Mallon, Robert; Hollander, Irwin; Feldberg, Larry; Lucas, Judy; Yu, Ker; Chaudhary, Inder; Mansour, Tarek S

    2010-10-01

    A series of mono-morpholino 1,3,5-triazine derivatives (8a-8q) bearing a 3-oxa-8-azabicyclo[3.2.1]octane were prepared and evaluated for PI3-kinase/mTOR activity. Replacement of one of the bis-morpholines in lead compound 1 (PKI-587) with 3-oxa-8-azabicyclo[3.2.1]octane and reduction of the molecular weight yielded 8m (PKI-179), an orally efficacious dual PI3-kinase/mTOR inhibitor. The in vitro activity, in vivo efficacy, and PK properties of 8m are discussed. Copyright © 2010. Published by Elsevier Ltd.

  16. p115 RhoGEF activates the Rac1 GTPase signaling cascade in MCP1 chemokine-induced vascular smooth muscle cell migration and proliferation.

    Science.gov (United States)

    Singh, Nikhlesh K; Janjanam, Jagadeesh; Rao, Gadiparthi N

    2017-08-25

    Although the involvement of Rho proteins in the pathogenesis of vascular diseases is well studied, little is known about the role of their upstream regulators, the Rho guanine nucleotide exchange factors (RhoGEFs). Here, we sought to identify the RhoGEFs involved in monocyte chemotactic protein 1 (MCP1)-induced vascular wall remodeling. We found that, among the RhoGEFs tested, MCP1 induced tyrosine phosphorylation of p115 RhoGEF but not of PDZ RhoGEF or leukemia-associated RhoGEF in human aortic smooth muscle cells (HASMCs). Moreover, p115 RhoGEF inhibition suppressed MCP1-induced HASMC migration and proliferation. Consistent with these observations, balloon injury (BI) induced p115 RhoGEF tyrosine phosphorylation in rat common carotid arteries, and siRNA-mediated down-regulation of its levels substantially attenuated BI-induced smooth muscle cell migration and proliferation, resulting in reduced neointima formation. Furthermore, depletion of p115 RhoGEF levels also abrogated MCP1- or BI-induced Rac1-NFATc1-cyclin D1-CDK6-PKN1-CDK4-PAK1 signaling, which, as we reported previously, is involved in vascular wall remodeling. Our findings also show that protein kinase N1 (PKN1) downstream of Rac1-cyclin D1/CDK6 and upstream of CDK4-PAK1 in the p115 RhoGEF-Rac1-NFATc1-cyclin D1-CDK6-PKN1-CDK4-PAK1 signaling axis is involved in the modulation of vascular wall remodeling. Of note, we also observed that CCR2-G i/o -Fyn signaling mediates MCP1-induced p115 RhoGEF and Rac1 GTPase activation. These findings suggest that p115 RhoGEF is critical for MCP1-induced HASMC migration and proliferation in vitro and for injury-induced neointima formation in vivo by modulating Rac1-NFATc1-cyclin D1-CDK6-PKN1-CDK4-PAK1 signaling. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Measurement of Exclusive $\\rho^0 \\rho^0$ Production in Two-Photon Collisions at High $Q^2$ at LEP

    CERN Document Server

    Achard, P.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M.G.; Anderhub, H.; Andreev, Valery P.; Anselmo, F.; Arefev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S.V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillere, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B.L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J.J.; Blyth, S.C.; Bobbink, G.J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J.G.; Brochu, F.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y.H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G.M.; Chen, H.F.; Chen, H.S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; van Dalen, J.A.; de Asmundis, R.; Deglon, P.; Debreczeni, J.; Degre, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M.T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F.J.; Extermann, P.; Falagan, M.A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J.H.; Filthaut, F.; Fisher, P.H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Iouri; Ganguli, S.N.; Garcia-Abia, Pablo; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z.F.; Grenier, Gerald Jean; Grimm, O.; Gruenewald, M.W.; Guida, M.; van Gulik, R.; Gupta, V.K.; Gurtu, A.; Gutay, L.J.; Haas, D.; Hatzifotiadou, D.; Hebbeker, T.; Herve, Alain; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S.R.; Hu, Y.; Jin, B.N.; Jones, Lawrence W.; de Jong, P.; Josa-Mutuberria, I.; Kafer, D.; Kaur, M.; Kienzle-Focacci, M.N.; Kim, J.K.; Kirkby, Jasper; Kittel, W.; Klimentov, A.; Konig, A.C.; Kopal, M.; Koutsenko, V.; Kraber, M.; Kraemer, R.W.; Kruger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J.M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C.H.; Lin, W.T.; Linde, F.L.; Lista, L.; Liu, Z.A.; Lohmann, W.; Longo, E.; Lu, Y.S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W.G.; Malgeri, L.; Malinin, A.; Mana, C.; Mans, J.; Martin, J.P.; Marzano, F.; Mazumdar, K.; McNeil, R.R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W.J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G.B.; Muanza, G.S.; Muijs, A.J.M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Kluge, Hannelies; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, Thomas Cantzon; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroue, P.A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, Mohammad Azizur; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, Keith; Roe, B.P.; Romero, L.; Rosca, A.; Rosier-Lees, S.; Roth, Stefan; Rosenbleck, C.; Rubio, J.A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schafer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D.J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D.P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L.Z.; Sushkov, S.; Suter, H.; Swain, J.D.; Szillasi, Z.; Tang, X.W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, Charles; Ting, Samuel C.C.; Ting, S.M.; Tonwar, S.C.; Toth, J.; Tully, C.; Tung, K.L.; Ulbricht, J.; Valente, E.; Van de Walle, R.T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobev, I.; Vorobyov, A.A.; Wadhwa, M.; Wang, Q.; Wang, X.L.; Wang, Z.M.; Weber, M.; Wienemann, P.; Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Z.Z.; Yamamoto, J.; Yang, B.Z.; Yang, C.G.; Yang, H.J.; Yang, M.; Yeh, S.C.; Zalite, An.; Zalite, Yu.; Zhang, Z.P.; Zhao, J.; Zhu, G.Y.; Zhu, R.Y.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.; Zoller, M.

    2003-01-01

    Exclusive rho rho production in two-photon collisions involving a single highly virtual photon is studied with data collected at LEP at centre-of-mass energies 89GeV rho rho is determined as a function of the photon virtuality, Q^2 and the two-photon centre-of-mass energy, Wgg, in the kinematic region: 1.2GeV^2 < Q^2 < 30GeV^2 and 1.1GeV < Wgg < 3GeV.

  18. Semiconductor technology in protein kinase research and drug discovery: sensing a revolution.

    Science.gov (United States)

    Bhalla, Nikhil; Di Lorenzo, Mirella; Estrela, Pedro; Pula, Giordano

    2017-02-01

    Since the discovery of protein kinase activity in 1954, close to 600 kinases have been discovered that have crucial roles in cell physiology. In several pathological conditions, aberrant protein kinase activity leads to abnormal cell and tissue physiology. Therefore, protein kinase inhibitors are investigated as potential treatments for several diseases, including dementia, diabetes, cancer and autoimmune and cardiovascular disease. Modern semiconductor technology has recently been applied to accelerate the discovery of novel protein kinase inhibitors that could become the standard-of-care drugs of tomorrow. Here, we describe current techniques and novel applications of semiconductor technologies in protein kinase inhibitor drug discovery. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Expression of a TGF-{beta} regulated cyclin-dependent kinase inhibitor in normal and immortalized airway epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Tierney, L.A.; Bloomfield, C.; Johnson, N.F. [and others

    1995-12-01

    Tumors arising from epithelial cells, including lung cancers are frequently resistant to factors that regulate growth and differentiation in normal in normal cells. Once such factor is transforming growth factor-{Beta} (TGF-{Beta}). Escape from the growth-inhibitory effects of TGF-{Beta} is thought to be a key step in the transformation of airway epithelial cells. most lung cancer cell lines require serum for growth. In contrast, normal human bronchial epithelial (NHBE) cells are exquisitely sensitive to growth-inhibitory and differentiating effects of TGF-{Beta}. The recent identification of a novel cyclin-dependent kinase inhibitor, p15{sup INK4B}, which is regulated by TGF-{Beta}, suggests a mechanism by which TGF-{Beta} mediates growth arrest in NHBE cells. The purpose of this study was two-fold: (1) to determine if p15{sup INK4B} is induced by TGF-{Beta} in NHBE cells or immortalized bronchial epithelial (R.1) cells and if that induction corresponds to a G1/S cell-cycle arrest; (2) to determine the temporal relationship between p15{sup INK4B} induction, cell-cycle arrest, and the phosphorylation state of the pRB because it is thought that p15{sup INK4B} acts indirectly by preventing phosphorylation of the RB gene product. In this study, expression of p15{sup INK4B} was examined in NHBE cells and R.1 cells at different time intervals following TGF-{Beta} treatment. The expression of this kinase inhibitor and its relationship to the cell and the pRb phosphorylation state were examined in cells that were both sensitive (NHBE) and resistant (R.1) to the effects of TGF-{Beta}. These results suggest that the cyclin-dependent kinase inhibitor, p15{sup INK4B}, is involved in airway epithelial cell differentiation and that loss or reduction of expression plays a role in the resistance of transformed or neoplastic cells to the growth-inhibitory effects of TGF-{Beta}.

  20. RhoA/ROCK Signaling Pathway Mediates Shuanghuanglian Injection-Induced Pseudo-allergic Reactions.

    Science.gov (United States)

    Han, Jiayin; Zhao, Yong; Zhang, Yushi; Li, Chunying; Yi, Yan; Pan, Chen; Tian, Jingzhuo; Yang, Yifei; Cui, Hongyu; Wang, Lianmei; Liu, Suyan; Liu, Jing; Deng, Nuo; Liang, Aihua

    2018-01-01

    Background: Shuanghuanglian injection (SHLI) is a famous Chinese medicine used as an intravenous preparation for the treatment of acute respiratory tract infections. In the recent years, the immediate hypersensitivity reactions induced by SHLI have attracted broad attention. However, the mechanism involved in these reactions has not yet been elucidated. The present study aims to explore the characteristics of the immediate hypersensitivity reactions induced by SHLI and deciphers the role of the RhoA/ROCK signaling pathway in these reactions. Methods: SHLI-immunized mice or naive mice were intravenously injected (i.v.) with SHLI (600 mg/kg) once, and vascular leakage in the ears was evaluated. Passive cutaneous anaphylaxis test was conducted using sera collected from SHLI-immunized mice. Naive mice were administered (i.v.) with a single dose of 150, 300, or 600 mg/kg of SHLI, and vascular leakage, histamine release, and histopathological alterations in the ears, lungs, and intestines were tested. In vitro , human umbilical vein endothelial cell (HUVEC) monolayer was incubated with SHLI (0.05, 0.1, or 0.15 mg/mL), and the changes in endothelial permeability and cytoskeleton were observed. Western blot analysis was performed and ROCK inhibitor was employed to investigate the contribution of the RhoA/ROCK signaling pathway in SHLI-induced hypersensitivity reactions, both in HUVECs and in mice. Results: Our results indicate that SHLI was able to cause immediate dose-dependent vascular leakage, edema, and exudates in the ears, lungs, and intestines, and histamine release in mice. These were pseudo-allergic reactions, as SHLI-specific IgE was not elicited during sensitization. In addition, SHLI induced reorganization of actin cytoskeleton and disrupted the endothelial barrier. The administration of SHLI directly activated the RhoA/ROCK signaling pathway both in HUVECs and in the ears, lungs, and intestines of mice. Fasudil hydrochloride, a ROCK inhibitor, ameliorated the

  1. A measurement of the branching ratio Σ+→rhoγ/Σ+→rhoπ0

    International Nuclear Information System (INIS)

    1985-06-01

    In an experiment performed in the CERN SPS hyperon beam a value for the branching ratio, Σ + →rhoγ/Σ + →rhoπ 0 of (2.46 sub(-0.35)sup(+0.30))x10 -3 , has been obtained corresponding to a branching ratio Σ + →rhoγ/Σ + → all of (1.27 sub(-0.18)sup(+0.16))x10 -3 . This result is discussed in the context of present understanding of hyperon radiative decays. (author)

  2. Neratinib, A Novel HER2-Targeted Tyrosine Kinase Inhibitor.

    Science.gov (United States)

    Tiwari, Shruti Rakesh; Mishra, Prasun; Abraham, Jame

    2016-10-01

    HER2 gene amplification and receptor overexpression is identified in 20% to 25% of human breast cancers. Use of targeted therapy for HER2-amplified breast cancer has led to improvements in disease-free and overall survival in this subset of patients. Neratinib is an oral pan HER inhibitor, that irreversibly inhibits the tyrosine kinase activity of epidermal growth factor receptor (EGFR or HER1), HER2, and HER4, which leads to reduced phosphorylation and activation of downstream signaling pathways. Neratinib is currently being tested in a number of clinical trials for its safety and efficacy in lung cancer, and colorectal, bladder, and breast cancers. In this review we discuss the available phase I, II, and III data for use of neratinib in the metastatic, adjuvant, neoadjuvant, and extended adjuvant settings along with the ongoing clinical trials of neratinib in breast cancer. We also elaborate on the side effect profile of this relatively new drug and provide guidelines for its use in clinical practice. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Carboxamide Spleen Tyrosine Kinase (Syk) Inhibitors: Leveraging Ground State Interactions To Accelerate Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, J. Michael; Altman, Michael D.; Cash, Brandon; Haidle, Andrew M.; Kubiak, Rachel L.; Maddess, Matthew L.; Yan, Youwei; Northrup, Alan B. (Merck)

    2016-12-08

    Optimization of a series of highly potent and kinome selective carbon-linked carboxamide spleen tyrosine kinase (Syk) inhibitors with favorable drug-like properties is described. A pervasive Ames liability in an analogous nitrogen-linked carboxamide series was obviated by replacement with a carbon-linked moiety. Initial efforts lacked on-target potency, likely due to strain induced between the hinge binding amide and solvent front heterocycle. Consideration of ground state and bound state energetics allowed rapid realization of improved solvent front substituents affording subnanomolar Syk potency and high kinome selectivity. These molecules were also devoid of mutagenicity risk as assessed via the Ames test using the TA97a Salmonella strain.

  4. Liquid chromatography-tandem mass spectrometric assay for the tyrosine kinase inhibitor afatinib in mouse plasma using salting-out liquid-liquid extraction

    NARCIS (Netherlands)

    Sparidans, Rolf W; van Hoppe, Stephanie; Rood, Johannes J M; Schinkel, Alfred H; Schellens, Jan H M; Beijnen, Jos H

    2016-01-01

    A quantitative bioanalytical liquid chromatography-tandem mass spectrometric (LC-MS/MS) assay for afatinib, an irreversible inhibitor of the ErbB (erythroblastic leukemia viral oncogene homolog) tyrosine kinase family, was developed and validated. Plasma samples were pre-treated using salting-out

  5. BFKL resummation effects in gamma* gamma* to rho rho

    Energy Technology Data Exchange (ETDEWEB)

    Enberg, R.; Pire, B.; Szymanowski, L.; Wallon, S.

    2005-08-11

    We calculate the leading order BFKL amplitude for the exclusive diffractive process {gamma}*{sub L}(Q{sub 1}{sup 2}) {gamma}*{sub L}(Q{sub 2}{sup 2}) {yields} {rho}{sub L}{sup 0}{rho}{sub L}{sup 0} in the forward direction, which can be studied in future high energy e{sup +}e{sup -} linear colliders. The resummation effects are very large compared to the fixed-order calculation. We also estimate the next-to-leading logarithmic corrections to the amplitude by using a specific resummation of higher order effects and find a substantial growth with energy, but smaller than in the leading logarithmic approximation.

  6. Autoregulation of kinase dephosphorylation by ATP binding to AGC protein kinases

    Science.gov (United States)

    Pascal, John M; Armen, Roger S

    2012-01-01

    AGC kinases, including the three Akt (protein kinase B) isoforms, protein kinase A (PKA) and all protein kinase C (PKC) isoforms, require activation loop phosphorylation (threonine 308 in Akt1) as well as phosphorylation of a C-terminal residue (serine 473 in Akt1) for catalytic activity and phosphorylation of downstream targets. Conversely, phosphatases reverse these phosphorylations. Virtually all cellular processes are affected by AGC kinases, a circumstance that has led to intense scrutiny of the molecular mechanisms that regulate phosphorylation of these kinases. Here, we review a new layer of control of phosphorylation in Akt, PKA and PKC pointing to ATP binding pocket occupancy as a means to decelerate dephosphorylation of these and, potentially, other kinases. This additional level of kinase regulation opens the door to search for new functional motifs for the rational design of non-ATP-competitive kinase inhibitors that discriminate within and between protein kinase families. PMID:22262182

  7. Icotinib, a selective EGF receptor tyrosine kinase inhibitor, for the treatment of non-small-cell lung cancer.

    Science.gov (United States)

    Tan, Fenlai; Shi, Yuankai; Wang, Yinxiang; Ding, Lieming; Yuan, Xiaobin; Sun, Yan

    2015-01-01

    Advanced non-small-cell lung cancer (NSCLC) is the main cause for cancer-related mortality. Treatments for advanced NSCLC are largely palliative and a benefit plateau appears to have reached with the platinum-based chemotherapy regimens. EGF receptor (EGFR) tyrosine kinase inhibitors gefitinib, erlotinib and afatinib came up with prolonged progression-free survival and improved quality of life, especially in EGFR-mutated patients. Icotinib is an oral selective EGFR tyrosine kinase, which was approved by China Food and Drug administration in June 2011 for treating advanced NSCLC. Its approval was based on the registered Phase III trial (ICOGEN), which showed icotinib is noninferior to gefitinib. This review will discuss the role of icotinib in NSCLC, and its potential application and ongoing investigations.

  8. Contractions activate hormone-sensitive lipase in rat muscle by protein kinase C and mitogen-activated protein kinase

    DEFF Research Database (Denmark)

    Donsmark, Morten; Langfort, Jozef; Holm, Cecilia

    2003-01-01

    and contractions. Adrenaline acts via cAMP-dependent protein kinase (PKA). The signalling mediating the effect of contractions is unknown and was explored in this study. Incubated soleus muscles from 70 g male rats were electrically stimulated to perform repeated tetanic contractions for 5 min. The contraction......Intramuscular triacylglycerol is an important energy store and is also related to insulin resistance. The mobilization of fatty acids from this pool is probably regulated by hormone-sensitive lipase (HSL), which has recently been shown to exist in muscle and to be activated by both adrenaline......-induced activation of HSL was abolished by the protein kinase C (PKC) inhibitors bisindolylmaleimide I and calphostin C and reduced 50% by the mitogen-activated protein kinase kinase (MEK) inhibitor U0126, which also completely blocked extracellular signal-regulated kinase (ERK) 1 and 2 phosphorylation. None...

  9. Radiation Effects on the Cytoskeleton of Endothelial Cells and Endothelial Monolayer Permeability

    International Nuclear Information System (INIS)

    Gabrys, Dorota; Greco, Olga; Patel, Gaurang; Prise, Kevin M.; Tozer, Gillian M.; Kanthou, Chryso

    2007-01-01

    Purpose: To investigate the effects of radiation on the endothelial cytoskeleton and endothelial monolayer permeability and to evaluate associated signaling pathways, which could reveal potential mechanisms of known vascular effects of radiation. Methods and Materials: Cultured endothelial cells were X-ray irradiated, and actin filaments, microtubules, intermediate filaments, and vascular endothelial (VE)-cadherin junctions were examined by immunofluorescence. Permeability was determined by the passage of fluorescent dextran through cell monolayers. Signal transduction pathways were analyzed using RhoA, Rho kinase, and stress-activated protein kinase-p38 (SAPK2/p38) inhibitors by guanosine triphosphate-RhoA activation assay and transfection with RhoAT19N. The levels of junction protein expression and phosphorylation of myosin light chain and SAPK2/p38 were assessed by Western blotting. The radiation effects on cell death were verified by clonogenic assays. Results: Radiation induced rapid and persistent actin stress fiber formation and redistribution of VE-cadherin junctions in microvascular, but not umbilical vein endothelial cells, and microtubules and intermediate filaments remained unaffected. Radiation also caused a rapid and persistent increase in microvascular permeability. RhoA-guanosine triphosphatase and Rho kinase were activated by radiation and caused phosphorylation of downstream myosin light chain and the observed cytoskeletal and permeability changes. SAPK2/p38 was activated by radiation but did not influence either the cytoskeleton or permeability. Conclusion: This study is the first to show rapid activation of the RhoA/Rho kinase by radiation in endothelial cells and has demonstrated a link between this pathway and cytoskeletal remodeling and permeability. The results also suggest that the RhoA pathway might be a useful target for modulating the permeability and other effects of radiation for therapeutic gain

  10. Testin, a novel binding partner of the calcium-sensing receptor, enhances receptor-mediated Rho-kinase signalling

    International Nuclear Information System (INIS)

    Magno, Aaron L.; Ingley, Evan; Brown, Suzanne J.; Conigrave, Arthur D.; Ratajczak, Thomas; Ward, Bryan K.

    2011-01-01

    Highlights: → A yeast two-hybrid screen revealed testin bound to the calcium-sensing receptor. → The second zinc finger of LIM domain 1 of testin is critical for interaction. → Testin bound to a region of the receptor tail important for cell signalling. → Testin and receptor interaction was confirmed in mammalian (HEK293) cells. → Overexpression of testin enhanced receptor-mediated Rho signalling in HEK293 cells. -- Abstract: The calcium-sensing receptor (CaR) plays an integral role in calcium homeostasis and the regulation of other cellular functions including cell proliferation and cytoskeletal organisation. The multifunctional nature of the CaR is manifested through ligand-dependent stimulation of different signalling pathways that are also regulated by partner binding proteins. Following a yeast two-hybrid library screen using the intracellular tail of the CaR as bait, we identified several novel binding partners including the focal adhesion protein, testin. Testin has not previously been shown to interact with cell surface receptors. The sites of interaction between the CaR and testin were mapped to the membrane proximal region of the receptor tail and the second zinc-finger of LIM domain 1 of testin, the integrity of which was found to be critical for the CaR-testin interaction. The CaR-testin association was confirmed in HEK293 cells by coimmunoprecipitation and confocal microscopy studies. Ectopic expression of testin in HEK293 cells stably expressing the CaR enhanced CaR-stimulated Rho activity but had no effect on CaR-stimulated ERK signalling. These results suggest an interplay between the CaR and testin in the regulation of CaR-mediated Rho signalling with possible effects on the cytoskeleton.

  11. Disseminated Infections with Talaromyces marneffei in Non-AIDS Patients Given Monoclonal Antibodies against CD20 and Kinase Inhibitors

    OpenAIRE

    Chan, Jasper F.W.; Chan, Thomas S.Y.; Gill, Harinder; Lam, Frank Y.F.; Trendell-Smith, Nigel J.; Sridhar, Siddharth; Tse, Herman; Lau, Susanna K.P.; Hung, Ivan F.N.; Yuen, Kwok-Yung; Woo, Patrick C.Y.

    2015-01-01

    Infections with the fungus Talaromyces (formerly Penicillium) marneffei are rare in patients who do not have AIDS. We report disseminated T. marneffei infection in 4 hematology patients without AIDS who received targeted therapy with monoclonal antibodies against CD20 or kinase inhibitors during the past 2 years. Clinicians should be aware of this emerging complication, especially in patients from disease-endemic regions.

  12. The new InsP3Kinase inhibitor BIP-4 is competitive to InsP3 and blocks proliferation and adhesion of lung cancer cells.

    Science.gov (United States)

    Schröder, Dominik; Tödter, Klaus; Gonzalez, Beatriz; Franco-Echevarría, Elsa; Rohaly, Gabor; Blecher, Christine; Lin, Hong-Ying; Mayr, Georg W; Windhorst, Sabine

    2015-07-15

    As ectopic expression of the neuronal inositol-1,4,5-trisphosphate-3-kinase A (InsP3Kinase) in tumor cells increases the metastatic potential, InsP3Kinase is an interesting target for tumor therapy. Recently, we have identified a membrane-permeable InsP3Kinase inhibitor (BAMB-4) exhibiting an IC50-value of 20 μM. Here we characterized a new InsP3Kinase inhibitor which shows a 130-fold lower IC50 value (157 ± 57 nM) as compared to BAMB-4. We demonstrate that this nitrophenolic compound, BIP-4, is non-competitive to ATP but competitive to InsP3, thus exhibits a high selectivity for inhibition of InsP3Kinase activity. Docking analysis suggested a putative binding mode of this molecule into the InsP3Kinase active site. Determination of cellular uptake in lung cancer cells (H1299) revealed that 6% of extracellular BIP-4 is internalized by non-endosomal uptake, showing that BIP-4 is not trapped inside endo/lysosomes but is available to inhibit cellular InsP3Kinase activity. Interestingly, we found that BIP-4 mediated inhibition of InsP3Kinase activity in the two lung cancer cell lines H1299 and LN4323 inhibited proliferation and adhesion at IC50 values of 3 μM or 2 μM, respectively. InsP3Kinase inhibition did not alter ATP-induced calcium signals but significantly reduced the level of Ins(1,3,4,5,6)P5. From these data we conclude that the inhibitory effect of BIP-4 on proliferation and adhesion of lung cancer cells does not result from alterations of calcium but from alterations of inositol phosphate signals. In summary, we reveal that inhibition of cellular InsP3Kinase by BIP-4 impairs proliferation and adhesion and therefore BIP-4 might be a promising compound to reduce the metastatic potential of lung carcinoma cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Tyrosine and aurora kinase inhibitors diminish transport function of multidrug resistance-associated protein (MRP 4 and breast cancer resistance protein (BCRP

    Directory of Open Access Journals (Sweden)

    Rhiannon N. Hardwick

    2016-12-01

    Full Text Available Tyrosine and aurora kinases are important effectors in signal transduction pathways that are often involved in aberrant cancer cell growth. Tyrosine (TKI and aurora (AKI kinase inhibitors are anti-cancer agents specifically designed to target such signaling pathways through TKI/AKI binding to the ATP-binding pocket of kinases thereby leading to diminished kinase activity. Some TKIs have been identified as inhibitors of ATP-binding cassette (ABC transporters such as P-glycoprotein and breast cancer resistance protein (BCRP, which are commonly upregulated in malignant cells. TKI/AKIs have been investigated as ABC transporter inhibitors in order to facilitate the accumulation of concomitantly administered chemo-therapeutics within cancer cells. However, ABC transporters are prominently expressed in the liver and other eliminating organs, and their inhibition has been linked to intracellular accumulation of drugs, altered disposition, and toxicity. The potential for TKIs/AKIs to inhibit other important hepatic efflux transporters, particularly multidrug resistance-associated proteins (MRPs, remains unknown. The aim of the current study was to compare the inhibitory potency of 20 selected TKI/AKIs against MRP4 and BCRP through the use of inverted membrane vesicle assays. Relative IC50 values were estimated by determining TKI/AKI inhibition of MRP4-mediated [3H]-dehydroepiandrosterone sulfate uptake and BCRP-mediated [3H]-estrone sulfate uptake. To provide insight to the clinical relevance of TKI/AKI inhibition of ABC efflux transporters, the ratio of the steady-state maximum total plasma concentration (Css to the IC50 for each compound was calculated with Css/IC50 ratio >0.1 deemed potentially clinically relevant. Such analysis identified several potentially clinically relevant inhibitors of MRP4: alisertib, danusertib, erlotinib, lapatinib, neratinib, nilotinib, pazopanib, sorafenib, and tozasertib. The potentially clinically relevant inhibition of

  14. Role of epimorphin in bile duct formation of rat liver epithelial stem-like cells: involvement of small G protein RhoA and C/EBPβ.

    Science.gov (United States)

    Jia, Yali; Yao, Hailei; Zhou, Junnian; Chen, Lin; Zeng, Quan; Yuan, Hongfeng; Shi, Lei; Nan, Xue; Wang, Yunfang; Yue, Wen; Pei, Xuetao

    2011-11-01

    Epimorphin/syntaxin 2 is a high conserved and very abundant protein involved in epithelial morphogenesis in various organs. We have shown recently that epimorphin (EPM), a protein exclusively expressed on the surface of hepatic stellate cells and myofibroblasts of the liver, induces bile duct formation of hepatic stem-like cells (WB-F344 cells) in a putative biophysical way. Therefore, the aim of this study was to present some of the molecular mechanisms by which EPM mediates bile duct formation. We established a biliary differentiation model by co-culture of EPM-overexpressed mesenchymal cells (PT67(EPM)) with WB-F344 cells. Here, we showed that EPM could promote WB-F344 cells differentiation into bile duct-like structures. Biliary differentiation markers were also elevated by EPM including Yp, Cx43, aquaporin-1, CK19, and gamma glutamyl transpeptidase (GGT). Moreover, the signaling pathway of EPM was analyzed by focal adhesion kinase (FAK), extracellular regulated kinase 1/2 (ERK1/2), and RhoA Western blot. Also, a dominant negative (DN) RhoA-WB-F344 cell line (WB(RhoA-DN)) was constructed. We found that the levels of phosphorylation (p) of FAK and ERK1/2 were up-regulated by EPM. Most importantly, we also showed that RhoA is necessary for EPM-induced activation of FAK and ERK1/2 and bile duct formation. In addition, a dual luciferase-reporter assay and CHIP assay was performed to reveal that EPM regulates GGT IV and GGT V expression differentially, possibly mediated by C/EBPβ. Taken together, these data demonstrated that EPM regulates bile duct formation of WB-F344 cells through effects on RhoA and C/EBPβ, implicating a dual aspect of this morphoregulator in bile duct epithelial morphogenesis. Copyright © 2011 Wiley-Liss, Inc.

  15. Synthesis and SAR of 1-acetanilide-4-aminopyrazole-substituted quinazolines: selective inhibitors of Aurora B kinase with potent anti-tumor activity.

    Science.gov (United States)

    Foote, Kevin M; Mortlock, Andrew A; Heron, Nicola M; Jung, Frédéric H; Hill, George B; Pasquet, Georges; Brady, Madeleine C; Green, Stephen; Heaton, Simon P; Kearney, Sarah; Keen, Nicholas J; Odedra, Rajesh; Wedge, Stephen R; Wilkinson, Robert W

    2008-03-15

    A new class of 1-acetanilide-4-aminopyrazole-substituted quinazoline Aurora kinase inhibitors has been discovered possessing highly potent cellular activity. Continuous infusion into athymic mice bearing SW620 tumors of the soluble phosphate derivative 2 led to dose-proportional exposure of the des-phosphate compound 8 with a high-unbound fraction. The combination of potent cell activity and high free-drug exposure led to pharmacodynamic changes in the tumor at low doses, indicative of Aurora B-kinase inhibition and a reduction in tumor volume.

  16. Neural cell adhesion molecule-stimulated neurite outgrowth depends on activation of protein kinase C and the Ras-mitogen-activated protein kinase pathway

    DEFF Research Database (Denmark)

    Kolkova, K; Novitskaya, V; Pedersen, N

    2000-01-01

    , inhibitors of the nonreceptor tyrosine kinase p59(fyn), PLC, PKC and MEK and an activator of PKC, phorbol-12-myristate-13-acetate (PMA). MEK2 transfection rescued cells treated with all inhibitors. The same was found for PMA treatment, except when cells concomitantly were treated with the MEK inhibitor....... Arachidonic acid rescued cells treated with antibodies to the FGF receptor or the PLC inhibitor, but not cells in which the activity of PKC, p59(fyn), FAK, Ras, or MEK was inhibited. Interaction of NCAM with a synthetic NCAM peptide ligand, known to induce neurite outgrowth, was shown to stimulate...... phosphorylation of the MAP kinases extracellular signal-regulated kinases ERK1 and ERK2. The MAP kinase activation was sustained, because ERK1 and ERK2 were phosphorylated in PC12-E2 cells and primary hippocampal neurons even after 24 hr of cultivation on NCAM-expressing fibroblasts. Based on these results, we...

  17. Microfilament regulatory protein MENA increases activity of RhoA and promotes metastasis of hepatocellular carcinoma.

    Science.gov (United States)

    Lin, Ling; Yang, Xiao-Mei; Li, Jun; Zhang, Yan-Li; Qin, Wenxin; Zhang, Zhi-Gang

    2014-09-10

    Mammalian enabled (MENA), usually known as a direct regulator of microfilament polymerization and bundling, promotes metastasis in various cancers. Here we focus on the role of MENA in hepatocellular carcinoma (HCC) metastasis and the relevant mechanism from the view of RhoA activity regulation. By HCC tissue microarray analysis, we found that MENA expression was positively associated with satellite lesions (PMENA staining in HCC tissues had significantly higher rates of early recurrence in the intermediate MENA expression group. Knockdown of MENA significantly suppressed HCC cell migration and invasion in vitro, as well as their intrahepatic and distant metastasis in vivo. Knockdown of MENA also decreased filopodia and stress fibers in SMMC-7721 cells. Furthermore, a decrease of RhoA activity was detected by a pull-down assay in SMMC-7721-shMENA cells. The ROCK inhibitor, Y-27632, suppressed migration of both MENA knockdown SMMC-7721 cells and control cells, but diminished their difference. Thus, our findings suggest that MENA promotes HCC cell motility by activating RhoA. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Dabrafenib, an inhibitor of RIP3 kinase-dependent necroptosis, reduces ischemic brain injury

    Directory of Open Access Journals (Sweden)

    Shelly A Cruz

    2018-01-01

    Full Text Available Ischemic brain injury triggers neuronal cell death by apoptosis via caspase activation and by necroptosis through activation of the receptor-interacting protein kinases (RIPK associated with the tumor necrosis factor-alpha (TNF-α/death receptor. Recent evidence shows RIPK inhibitors are neuroprotective and alleviate ischemic brain injury in a number of animal models, however, most have not yet undergone clinical trials and safety in humans remains in question. Dabrafenib, originally identified as a B-raf inhibitor that is currently used to treat melanoma, was later revealed to be a potent RIPK3 inhibitor at micromolar concentrations. Here, we investigated whether Dabrafenib would show a similar neuroprotective effect in mice subjected to ischemic brain injury by photothrombosis. Dabrafenib administered intraperitoneally at 10 mg/kg one hour after photothrombosis-induced focal ischemic injury significantly reduced infarct lesion size in C57BL6 mice the following day, accompanied by a markedly attenuated upregulation of TNF-α. However, subsequent lower doses (5 mg/kg/day failed to sustain this neuroprotective effect after 4 days. Dabrafenib blocked lipopolysaccharides-induced activation of TNF-α in bone marrow-derived macrophages, suggesting that Dabrafenib may attenuate TNF-α-induced necroptotic pathway after ischemic brain injury. Since Dabrafenib is already in clinical use for the treatment of melanoma, it might be repurposed for stroke therapy.

  19. Discovery of novel inhibitors for Leishmania nucleoside diphosphatase kinase (NDK) based on its structural and functional characterization

    Science.gov (United States)

    Mishra, Arjun K.; Singh, Nidhi; Agnihotri, Pragati; Mishra, Shikha; Singh, Saurabh P.; Kolli, Bala K.; Chang, Kwang Poo; Sahasrabuddhe, Amogh A.; Siddiqi, M. I.; Pratap, J. Venkatesh

    2017-06-01

    Nucleoside diphosphate kinases (NDKs) are ubiquitous enzymes that catalyze the transfer of the γ-phosphate moiety from an NTP donor to an NDP acceptor, crucial for maintaining the cellular level of nucleoside triphosphates (NTPs). The inability of trypanosomatids to synthesize purines de novo and their dependence on the salvage pathway makes NDK an attractive target to develop drugs for the diseases they cause. Here we report the discovery of novel inhibitors for Leishmania NDK based on the structural and functional characterization of purified recombinant NDK from Leishmania amazonensis. Recombinant LaNDK possesses auto-phosphorylation, phosphotransferase and kinase activities with Histidine 117 playing an essential role. LaNDK crystals were grown by hanging drop vapour diffusion method in a solution containing 18% PEG-MME 500, 100 mM Bis-Tris propane pH 6.0 and 50 mM MgCl2. It belongs to the hexagonal space group P6322 with unit cell parameters a = b = 115.18, c = 62.18 Å and α = β = 90°, γ = 120°. The structure solved by molecular replacement methods was refined to crystallographic R-factor and Rfree values of 22.54 and 26.52%, respectively. Molecular docking and dynamics simulation -based virtual screening identified putative binding compounds. Protein inhibition studies of selected hits identified five inhibitors effective at micromolar concentrations. One of the compounds showed 45% inhibition of Leishmania promastigotes proliferation. Analysis of inhibitor-NDK complexes reveals the mode of their binding, facilitating design of new compounds for optimization of activities as drugs against leishmaniasis.

  20. The discovery and the structural basis of an imidazo[4,5-b]pyridine-based p21-activated kinase 4 inhibitor.

    Science.gov (United States)

    Park, Jeung Kuk; Kim, Sunmin; Han, Yu Jin; Kim, Seong Hwan; Kang, Nam Sook; Lee, Hyuk; Park, SangYoun

    2016-06-01

    p21-Activated kinases (PAKs) which belong to the family of ste20 serine/threonine protein kinases regulate cytoskeletal reorganization, cell motility, cell proliferation, and oncogenic transformation which are all related to the cellular functions during cancer induction and metastasis. The fact that PAK mutations are detected in multiple tumor tissues makes PAKs a novel therapeutic drug target. In this study, an imidazo[4,5-b]pyridine-based PAK4 inhibitor, KY-04045 (6-Bromo-2-(3-isopropyl-1-methyl-1H-pyrazol-4-yl)-1H-imidazo[4,5-b]pyridine), was discovered using a virtual site-directed fragment-based drug design and was validated using an inhibition assay. Although PAK4 affinity to KY-04045 seems much weaker than that of the reported PAK4 inhibitors, the location of KY-04045 is clearly defined in the structure of PAK4 co-crystallized with KY-04045. The crystal structure illustrates that the pyrazole and imidazopyridine rings of KY-04045 are sufficient for mediating PAK4 hinge loop interaction. Hence, we believe that KY-04045 can be exploited as a basic building block in designing novel imidazo[4,5-b]pyridine-based PAK4 inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.